Skip common site navigation and headers
United States Environmental Protection Agency
Exposure Research
Begin Hierarchical Links EPA Home > Research & Development > Exposure Research > Publications/Presentations > End Hierarchical Links

 

Human Exposure and Atmospheric Sciences Division Publications: 2003

spacer
spacer

This page lists publication titles, citations and abstracts produced by NERL's Human Exposure and Atmospheric Sciences Division for the year 2003, organized by Publication Type. Your search has returned 181 Matching Entries.

See also Human Exposure and Atmospheric Sciences Division citations with abstracts: 1999,  2000,  2001,  2002,  2003,  2004,  2005,  2006,  2007,  2008,  2009

Technical Information Manager: Liz Hope - (919) 541-2785 or hope.elizabeth@epa.gov

spacer
Presented/Published
BOOK CHAPTER Monitoring, Assessment, and Environmental Policy 12/17/2003
Messer, J J. Monitoring, Assessment, and Environmental Policy. Chapter 22, Environmental Monitoring and Assessment. CRC Press LLC, Boca Raton, FL, 499-515, (2003).
Abstract: This overview chapter examines the roles that environmental monitoring and assessment can play in the development of environmental policy. It takes a case study approach, focusing on the key roles played by monitoring data in policy formulation in acid deposition, stratospheric ozone depletion, global climate change, criteria air pollutants, water quality management under the CWA, and the growing interest in environmental "report cards." Specifically excluding emissions monitoring, the most important role played by monitoring in the examples has been problem identification and analysis. Its role in program evaluation is increasing, but is limited by a lack of relevant, high quality data. Monitoring less frequently plays a key role in setting targets and establishing priorities, and in program management and execution.
This chapter has been approved for publication by the United States Environmental Protection Agency, but the opinions are those of the author, and do not necessarily reflect the official views or policies of the Agency.

BOOK CHAPTER Environmental Endocrine Disruptors 11/25/2003
Vallero, D A. Environmental Endocrine Disruptors. , Environmental Endocrine Disruptors 2004 Yearbook of Science and Technology. McGraw-Hill Companies, New York, NY, 96-100, (2003).
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

JOURNAL Effect of Ventilation Systems and Air Filters on Decay Rates of Particles Produced By Indoor Sources in An Occupied Townhouse 12/01/2003
HowardReed, C., L A. Wallace, AND S. J. Emmerich. Effect of Ventilation Systems and Air Filters on Decay Rates of Particles Produced By Indoor Sources in An Occupied Townhouse. ATMOSPHERIC ENVIRONMENT 37(38):5295-5306, (2003).
Abstract: Several studies have shown the importance of particle losses in real homes due to deposition and filtration; however, none have quantitatively shown the impact of using a central forced air fan and in-duct filter on particle loss rates. In an attempt to provide such data, we measured the deposition of particles ranging from 0.3 um to 10 um in an occupied townhouse and also in an unoccupied test house. Experiments were run with three different sources (cooking with a gas stove, citronella candle, pouring kitty litter), with the central heating and air conditioning (HAC) fan on or off, and with two different types of in-duct filters (electrostatic precipitator and ordinary furnace filter). Particle size, HAC fan operation, and the electrostatic precipitator had significant effects on particle loss rates. The standard furnace filter had no effect. Surprisingly, the type of source (combustion vs. mechanical generation) and the type of furnishings (fully furnished including carpet vs. largely unfurnished including mostly bare floor) also had no measurable effect on the deposition rates of particles of comparable size. With the HAC fan off, deposition rates varied from 0.3 h-1 for the smallest particle range (0.3 um to 0.5 um) to 5.2 h-1 for particles greater than 10 um. Operation of the central HAC fan approximately doubled these rates for particles < 5 um, and increased rates by 2 h-1 for the larger particles. An in-duct electrostatic precipitator increased the loss rates compared to the fan-off condition by factors of 5 to 10 for particles < 2.5 um, and by a factor of 3 for 2.5 um to 5.0 um particles. In practical terms, use of the central fan alone could reduce indoor particle concentrations by 25 % to 50 %, and use of an in-duct ESP could reduce particle concentrations by 55 % to 85 % compared to fan-off conditions.
This study was partially funded by an EPA Internal Grant to the corresponding author. It has been reviewed and cleared for publicaiton. Certain commercial equipment, instruments, or materials are identified in this paper in order to specify the experimental procedure adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the materials or equipment identified are necessarily the best available for the purpose.

JOURNAL The Research Triangle Park Particulate Matter Panel Study: PM Mass Concentration Relationships 12/01/2003
Williams, R W., J C. Suggs, A W. Rea, K W. Leovic, A F. Vette, C Croghan, L S. Sheldon, C. Rodes, J. Thornburg, A. Ejire, M. Herbst, AND W. Sanders Jr. The Research Triangle Park Particulate Matter Panel Study: PM Mass Concentration Relationships. ATMOSPHERIC ENVIRONMENT 37(38):5349-5363, (2003).
Abstract: The U.S. Environmental Protection Agency has recently performed the Research Triangle Park Particulate Matter Panel Study. This was a one-year investigation of PM and related co-pollutants involving participants living within the RTP area of North Carolina. Primary goals were to characterize the relationships between ambient and residential PM measures to those obtained from personal exposure monitoring and estimate ambient source contributions to personal and indoor mass concentrations. A total of 38 participants living in 37 homes were involved in personal, residential indoor, residential outdoor and ambient PM2.5 exposure monitoring. Participating were 30 nonsmoking hypertensive African-Americans living in a low-moderate SES neighborhood (SE Raleigh, NC) and a cohort of eight individuals having implanted cardiac defibrillators (Chapel Hill, NC). Residential and ambient monitoring of PM10 and PM10.2.5 (coarse by differential) was also performed. The volunteers were monitored for seven consecutive days during each of four seasons (summer 2000, fall 2000, winter 2001, spring 2001). Individual PM2.5 personal exposure concentrations ranged from 4 to 218 ug/m3 during the study. The highest personal exposures were determined to be the result of passive environmental tobacco exposures. Subsequently, ~ 7% of the total number of personal exposure trials were excluded to minimize this pollutant's affect upon the overall analysis. Results indicated that a pooled dataset (seasons, cohorts, residences, participants) was appropriate for investigation of the basic mass concentration relationships. Daily personal PM2.5 mass concentrations were typically higher than their associated residential or ambient measurements (mean personal = 23.0, indoor = 19.1, outdoor = 19.3, ambient = 19.2 ug m-3). Mean personal PM 2.5, exposures were observed to be only moderately correlated to ambient PM2.5 concentrations (r = 0.39).
The US Environmental Protection Agency through its Office of Research and Development funded and conducted the research described here under contract #68-D-99-012 to the Research Triangle Institute International and to Shaw University under collaborative agreement #CR-828186. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial product does not constitute endorsement or recommendation for use.

JOURNAL The Distribution of Chlorpyrifos Following a Crack and Crevice Type Application in the U.S. EPA Indoor Air Quality Research House 12/01/2003
Stout II, D M. AND M. Mason. The Distribution of Chlorpyrifos Following a Crack and Crevice Type Application in the U.S. EPA Indoor Air Quality Research House. ATMOSPHERIC ENVIRONMENT 37(39/40):5539-5549, (2003).
Abstract: A study was conducted in the U.S. EPA Indoor Air Quality Research House to determine the spatial and temporal distribution of chlorpyrifos following a professional crack and crevice application in the kitchen. Following the application, measurements were made in the kitchen, den and master bedroom over 21-days. Airborne concentrations were collected using both polyurethane foam (PUF) and the OSHA Versatile Sampler (OVS) composed of XAD and PUF media located in tandem. Measured airborne concentrations were similar for the two samplers and were higher in the three rooms following the application. The highest measured concentrations were reached during the initial 24-h following application; concentrations subsequently declined over the 21-day study period to levels slightly above background. Spatial and temporal distributions onto surfaces were measured using 10-cm2 rayon deposition coupons located on the floor. Sections were cut from existing carpet to determine the total extractable residues. Chlorpyrifos was measured from all matrixes in the kitchen, den and bedroom and the data shows the transport of airborne residues from the point of application to remote locations in the house. The findings are compared and discussed relative to another study conducted in which total release aerosols containing chlorpyrifos were activated in the indoor air quality research house and the resulting distributions evaluated. For both studies dose estimates were constructed for the exposure pathways using the Stochastic Human Exposure and Dose Estimation Model for pesticides.
The United States Environmental Protection Agency through its Office of Research and Development funded and managed the research described here. It has been subjected to Agency's administrative review and approved for publication as an EPA document

JOURNAL The Research Triangle Park Particulate Matter Panel Study: Modeling Ambient Source Contribution to Personal and Residential PM Mass Concentrations 12/01/2003
Williams, R W., J C. Suggs, A W. Rea, L S. Sheldon, C. Rodes, AND J. Thornburg. The Research Triangle Park Particulate Matter Panel Study: Modeling Ambient Source Contribution to Personal and Residential PM Mass Concentrations. ATMOSPHERIC ENVIRONMENT 37(36):5365-5378, (2003).
Abstract: The Research Triangle Park (RTP) Particulate Matter (PM) Panel Study represented a one-year investigation of personal, residential and ambient PM mass concentrations across distances as large as 70 km in central North Carolina. One of the primary goals of this effort was to estimate ambient PM2.5 contributions to personal and indoor residential PM mass concentrations. Analyses indicated that data from the two distinct non-smoking subject populations totaling 38 individuals and 37 residences could be pooled. This resulted in nearly 800 data points for each variable. A total of 55 measurements believed to have been potentially influenced by personal or residential exposure to passive environmental tobacco smoke were not included in the analysis database. Variables to be examined included Cig (concentration of indoor generated PM), Eig (personal exposure to indoor generated PM), Finf (ambient PM infiltration factor), and Fpex (personal exposure to PM of ambient origin factor). Daily air exchange rates (AER) were measured and statistical modeling to derive estimates of particle penetration (P) and particle deposition (k) factors was performed. Seasonality, cohort grouping, participant or combinations of these variables were determined not to be significant influences in estimating group infiltration factors. The mean (+/- std) mixed model slope estimates were AER = 0.72 +/- 0.63, P = 0.72 +/- 0.21, k = 0.42 +/- 0.19, and Finf = 0.45 +/- 0.21. These variables were then used in a number of mixed effects models having varying features of single, random or fixed intercepts and/or slopes to determine the most appropriate means of estimating ambient source contributions to personal and residential settings. A mixed model slope for Fpex (+/- SE) was 0.47 +/- 0.07 using the model with the highest degree of fit.
The US Environmental Protection Agency through its Office of Research and Development funded and conducted the research described here. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use

JOURNAL Source Apportionment of PM2.5 at An Urban Improve Site in Seattle, Wa 11/15/2003
Maykut, N., J Lewtas, E. Kim, AND T. Larson. Source Apportionment of PM2.5 at An Urban Improve Site in Seattle, Wa. ENVIRONMENTAL SCIENCE & TECHNOLOGY 37(22):5135-5142, (2003).
Abstract: The multivariate receptor models Positive Matrix Factorization (PMF) and Unmix were used along with EPA's Chemical Mass Balance model to deduce the sources of PM2.5 at a centrally located urban site in Seattle, Washington. A total of 289 filter samples were obtained with an IMPROVE Sampler from 1996 through 1999 and were analyzed for 31 particulate elements including temperature resolved fractions of the particulate organic and elemental carbon. All three receptor models predicted that the major sources of PM2.5 were vegetative burning (including wood stoves), mobile sources, and secondary particle formation, with lesser contributions from re-suspended soil and sea spray. The PMF and Unmix models were able to resolve a fuel oil combustion source as well as distinguish between diesel emissions and other mobile sources. In addition, the average source contribution estimates via PMF and Unmix agreed well with an existing emissions inventory. Using the temperature resolved organic and elemental carbon fractions provided in the IMPROVE protocol, rather than the total organic and elemental carbon, allowed the Unmix model to separate diesel from other mobile sources. The PMF model was able to do this without the additional carbon species, relying on selected trace elements to distinguish the various combustion sources.
This paper has been reviewed in accordance with the US Environmental Protection Agency's peer and administrative review policies and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. The US EPA partially funded the research described here under a contract with Puget Sound Clean Air Agency. Part of this study was funded by the UW/EPA Northwest Research Center for Particulate Air Pollution and Health (R827355)

JOURNAL An Air Quality Data Analysis System for Interrelating Effects, Standards, and Needed Source Reductions: Part 13. Applying the EPA Proposed Guidelines for Carcinogen Risk Assessment to a Set of Asbestos Lung Cancer Mortality Data 11/01/2003
Larsen, R. I. An Air Quality Data Analysis System for Interrelating Effects, Standards, and Needed Source Reductions: Part 13. Applying the EPA Proposed Guidelines for Carcinogen Risk Assessment to a Set of Asbestos Lung Cancer Mortality Data. JOURNAL OF THE AIR AND WASTE MANAGEMENT ASSOCIATION 53(11):1326-1339, (2003).
Abstract: The Clean Air Act Amendments of 1990 (CAAA-90) list 189 hazardous air pollutants (HAPs) for which "safe" ambient concentrations are to be determined. For a carcinogen, such as asbestos, the amendments specify that the safe concentration shall allow one excess cancer case per million people. To calculate a safe ambient asbestos concentration from one set of data, the EPA Proposed Guidelines for Carcinogen Risk Assessment are applied here to lung cancer mortality data for a cohort of 820 men who were exposed to airborne asbestos while working in a New Jersey asbestos factory. Data on their excess lung cancer mortality, expressed as a function of asbestos exposure, are fitted to two separate mathematical models, lognormal and logarithmic. Both models fit the data well and give almost identical answers. Since both models fit the data well, these two models might also be tried for other asbestos data and data for other HAPs. Averaged together these two models suggest a "safe" lifetime-mean ambient air concentration of 0.085 asbestos fibers per cubic meter of air. But measurements suggest that background asbestos concentrations may be about 1000 times this "safe" concentration, suggesting that this calculated safe concentration cannot be achieved. A Letter to the Editor and a Response that immediately follow this paper cite data that suggest that the "safe" concentration should probably be about 730 times as high as calculated in this paper. The Response suggests that the major reason for this discrepancy is because this paper uses the default assumption that excess mortality is linearly proportional to asbestos exposure from the "Point of Departure" down to zero excess mortality at zero exposure. The Response continues by acknowledging that this is a very weak assumption and then uses a nonlinear default assumption together with the factor of 730 to calculate that the relationship, instead of being linear, could be expressed as the "safe" asbestos concentration being proportional to the desired mortality level raised to the 0.39 power. The importance of determining the correct nonlinear relationship for any carcinogenic HAP is suggested as possibly the most important problem in setting a future "safe" concentration for any HAP. The following caveats for this study need to be stated. A prime reason for selecting this particular asbestos data set was that it covered a 100-fold exposure range and the primary purpose of this paper was to develop the two mathematical models (lognormal and logarithmic) that covered this large range. Also, only two sets of asbestos data are discussed here. All available asbestos excess mortality data would be considered, studied, and analyzed to determine any "safe" asbestos concentration that would be issued by the EPA.
The United States Environmental Protection Agency through its Office of Research and Development funded and managed the research described here. It has been subjected to the Agency's administrative review and approved for publication.

JOURNAL Polar Organic Oxygenates in PM2.5 at a Southeastern Site in the United States 09/01/2003
Edney, E O., T E. Kleindienst, T. S. Conver, C. D. McIver, AND W Weathers. Polar Organic Oxygenates in PM2.5 at a Southeastern Site in the United States. ATMOSPHERIC ENVIRONMENT 38(28):3947-3965, (2003).
Abstract: A field study was undertaken in Research Triangle Park, NC, USA, during the summer of 2000 to identify classes of polar oxygenates in PM2.5 containing carbonyl and/or hydroxyl functional groups and, to the extent possible, determine the individual particle-bound oxygenates that make up each class. The selected site was in a semi-rural environment with expected impacts from both biogenic and anthropogenic sources. PM2.5 samples were collected and analyzed for gravimetric mass, inorganic composition by ion chromatography, polar oxygenated compounds by gas chromatography-mass spectroscopy after derivatization of the solvent extracts, organic and elemental carbon by a thermal-optical method, and chemical functional groups by infrared spectroscopy. The chemical analyses also included determining the polarity of the PM2.5 by measuring the organic carbon concentrations in a series of extraction solvents of increasing polarity. The ambient PM2.5 mass concentrations ranged between 9 and 30 ug m-3, with an average mass composition of 28% sulfate, 6% nitrate, 12% ammonium, 39% organic carbon compound, 2% elemental carbon, and 12% liquid water at a relative humidity of 43%. Organic carbon analyses of the organic extracts indicated approximately 89% of the extractable organic carbon was more polar in nature than that extracted by n-hexane. Infrared analysis of the PM2.5 was consistent with the presence of significant levels of polar carbonyl and hydroxyl functional groups. The polar nature of the organic fraction was further supported by the observation that the inorganic fraction accounted for only about 80% of measured liquid water concentrations in the PM2.5. The mass spectra data were consistent with the presence of the following classes of oxygenates: oxo monocarboxylic acids, trihydroxy monocarboxylic acids, dihydroxy dicarboxylic acids, hydroxy dicarboxylic acids, normal dicarboxylic acids, oxo dicarboxylic acids, methoxy dicarboxylic acids, tricarboxylic acids, triols, and photooxidation products of a-pinene and toluene. In particular, five secondary organic aerosol compounds observed in a smog chamber irradiation of an a-pinene/NOx/air mixture were detected in ambient PM2.5.
The U.S. Environmental Protection Agency through its Office of Research and Development funded and collaborated in the research described here under Contract 68-D-00-206 to ManTech Environmental Technology, Inc. It has been subject to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

JOURNAL Comments on "MERCURY Concentrations in Coastal California Precipitation: Evidence of Local and Trans-Pacific Fluxes of Mercury to North America" By Steding and Flegal (2002) 09/01/2003
Jaffe, D., M S. Landis, P. WeissPenzias, AND E. Prestbo. Comments on "MERCURY Concentrations in Coastal California Precipitation: Evidence of Local and Trans-Pacific Fluxes of Mercury to North America" By Steding and Flegal (2002). JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 108(D17):ACH 11-1 to ACH 11-2, (2003).
Abstract: In a paper by Steding and Flegal [2002], the authors claim to identify Hg in rain from trans-Pacific sources. However, we disagree with this conclusion. Our disagreement derives from evaluation of meteorological factors, statistical analyses and identification of the local contribution to Hg in rain measured at their sites.
This work has been funded wholly or in part by the U.S. Environmental Protection Agency Office of Research and Development. It has been subjected to Agency Review and approved for publication.

JOURNAL Ozone Production Efficiency and NOx Depletion in An Urban Plume: Interpretation of Field Observations and Implications for Evaluating O3-NOx-VOC Sensitivity 07/31/2003
Zaveri, R. A., C. Berkowitz, L. I. Kleinman, R. Springston, P. V. Doskey, W A. Lonneman, AND C. W. Spicer. Ozone Production Efficiency and NOx Depletion in An Urban Plume: Interpretation of Field Observations and Implications for Evaluating O3-NOx-VOC Sensitivity. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 108(D14):ACH12-1 to ACH12-23, (2003).
Abstract: Ozone production efficiency (OPE) can be defined as the number of ozone (O3) molecules photochemically produced by a molecule of NOx (NO + NO2) before it is lost from the NOx - O3 cycle. Here, we consider observational and modeling techniques to evaluate various operational definitions of OPEs using aircraft and surface measurements taken as part of the 1999 Southern Oxidant Study field campaign in Nashville, Tennessee. A key tool in our analysis is a Lagrangian box model, which is used to quantitatively describe the effects of emissions, dilution, dry deposition, and photochemistry in an urban air parcel as it was advected downwind. After evaluating the model using the observed downwind concentrations of several key species, we show that the modeled NOx oxidation and O3 production rates as well as the associated instantaneous and cumulative OPEs depend on the time of day and the photochemical age of the air parcel. The observation-based OPEs are found to be consistent with the modeled values with the expected biases. A model sensitivity study suggests that downwind O3 concentrations in the Nashville plume are more sensitive to NOx emissions than anthropogenic VOC emissions. Because the OPE exhibits a nonlinear dependence on emissions and meteorological effects, it would be difficult to rely only on observations to map out the non-linear response of O3 to a wide span of NOx and VOC emission changes. Properly constrained and well-evaluated models using a variety of observations are therefore necessary to reliably predict O3-NOx-VOC sensitivity for designing effective O3 control strategies.
The U.S. Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under contract CQ829757 to the National Caucus and Center on Black Aged.

JOURNAL Gaseous Elemental Mercury in the Marine Boundary Layer: Evidence for Rapid Removal in Anthropogenic Pollution 07/26/2003
WeissPenzias, P., D. Jaffe, A. McClintick, E. Prestbo, AND M S. Landis. Gaseous Elemental Mercury in the Marine Boundary Layer: Evidence for Rapid Removal in Anthropogenic Pollution. ENVIRONMENTAL SCIENCE & TECHNOLOGY 37(17):3755-3763, (2003).
Abstract: In this study, gas-phase elemental mercury (Hg0) and related species (including inorganic reactive gaseous mercury (RGM) and particulate mercury (PHg)) were measured at Cheeka Peak Observatory (CPO), Washington State, in the marine boundary layer (MBL) during 2001-2002. Air of continental origin containing anthropogenic pollutants from the urban areas to the east contained on average 5.3% lower Hg0 levels compared to the marine background. This result is difficult to reconcile since it is known that industrial emissions in our region are sources of Hg0. The rate of removal of Hg0 from a pollution plume necessary to account for our observations is inconsistent with the accepted view of Hg0 as a stable atmospheric pollutant. The largest and most frequent Hg0 loss events occurred in the presence of increased ozone (O3) during the summer. Hg0 and O3 also display diurnal cycles that are out-of-phase with one another. In other seasons Hg0 behavior is less consistent, as we observe weak positive correlations with O3, and occasional Hg0 enhancements in local pollution. RGM and PHg concentrations are enhanced only slightly during Hg0 loss events, comprising a small fraction of the mercury pool (~3%). Long-range transported pollution of Asian origin was also detected at CPO and this contains both higher and lower levels of Hg0 compared to the background, with maximum changes being < 20%. Here, the more photochemically processed the air mass, as determined by propane/ethane ratios, the more likely we are to observe Hg0 loss. Air from the marine background in summer displays a significant diurnal cycle with a phase that matches the diurnal cycles seen in polluted air masses. A Junge lifetime for Hg0 in the clean marine boundary layer is calculated to be 7.1 months, which is on the low end of previous estimates (1/2 -2 years).
This work was funded by the U.S. Environmental Protection Agency Office of International Affairs and Office of Research and Development (Cooperative Agreement X-82825001-0). It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

JOURNAL Polycyclic Aromatic Hydrocarbons (PAHs) and Other Semi-Volatile Organic Compounds Collected in New York City in Response to the Events of 9/11 07/22/2003
Swartz, E, L Stockburger, AND D A. Vallero. Polycyclic Aromatic Hydrocarbons (PAHs) and Other Semi-Volatile Organic Compounds Collected in New York City in Response to the Events of 9/11. ENVIRONMENTAL SCIENCE & TECHNOLOGY 37(16):3537-3546, (2003).
Abstract: Concentrations of over 60 non-polar semi-volatile and non-volatile organic compounds were measured in Lower Manhattan, New York using a high capacity Integrated Organic Gas and Particle Sampler, after the initial destruction of the World Trade Center. The results indicate that the remaining air plumes from the disaster site were comprised of many pollutants and classes and represent a complex mixture of biogenic (wood-smoke) and anthropogenic sources. This mixture includes compounds that are typically associated with fossil fuel emissions and their combustion products. The molecular markers for these emissions include the high molecular weight PAHs, the n-alkanes, a Carbon Preference Index ~ 1 (odd carbon:even carbon ~ 1), as well as pristane and phytane as specific markers for fuel oil degradation. These results are not unexpected considering the large number of diesel generators and outsized vehicles used in the removal phases. The resulting air plume would also include emissions of burning and remnant materials from the WTC site. Only a small number of molecular markers for these emissions have been identified such as retene and 1,4a-dimethyl-7-(methylethyl)-1,2,3,4,9,10,10a,4a-octahydrophenanthrene which are typically biogenic in origin. In addition, the compound 1,3-diphenyl propane [1',1'-(1,3-propanediyl)bis-benzene] was observed and, to our knowledge, this species has not previously been reported from ambient sampling. It has been associated with polystyrene and other plastics, which are in abundance at the WTC site. These emissions lasted for at least three weeks (9/26/01-10/21/01) after the initial destruction of the WTC.
The United States Environmental Protection Agency through its Office of Research and Development funded and managed the research described here. It has been subjected to Agency Review and approval for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

JOURNAL Comments on "MEASUREMENTS of Atmospheric Mercury Species at a Coastal Site in the Antarctic and Over the South Atlantic Ocean During Polar Summer" 07/15/2003
Landis, M S. AND R. K. STEVENS. Comments on "MEASUREMENTS of Atmospheric Mercury Species at a Coastal Site in the Antarctic and Over the South Atlantic Ocean During Polar Summer". JOURNAL OF ENVIRONMENTAL SCIENCE AND TECHNOLOGY. American Chemical Society, Washington, DC, 37(14):3239-3240, (2003).
Abstract: Attached comment submitted to Environmental Science and Technology entitled, Comments on "Measurements of Atmospheric Mercury Species at a Costal Site in the Antarctic and over the South Atlantic Ocean during Polar Summer" by Temme et al. Environmental Science and Technology 37 (2003), 22-31. The comment addresses my concerns over the author's misapplication of mercury measurement methodologies and the misinterpretation of meteorological trajectory analysis.
This work has been funded by the U.S. Environmental Protection Agency Office of Research and Development. It has been subjected to Agency Review and approved for publication.


JOURNAL Use of Real-Time Light Scattering Data to Estimate the Contribution of Infiltrated and Indoor-Generated Particles to Indoor Air 07/11/2003
Allen, R., T. Larson, L. Sheppard, L A. Wallace, AND L. S. Liu. Use of Real-Time Light Scattering Data to Estimate the Contribution of Infiltrated and Indoor-Generated Particles to Indoor Air. ENVIRONMENTAL SCIENCE & TECHNOLOGY 37(16):3484-3492, (2003).
Abstract: The contribution of outdoor particulate matter (PM) to residential indoor concentrations is currently not well understood. Most importantly, separating indoor PM into indoor- and outdoor-generated components will greatly enhance our knowledge of the outdoor contribution to total indoor and personal PM exposures. This paper examines continuous light scattering data at 44 residences in Seattle, WA. A newly adapted recursive model was used to model outdoor-originated PM entering indoor environments. Non-linear regression was used to predict particle penetration (P, 0.94 +/- 0.10), air exchange rate (a, 0.54 +/- 0.60 hr-1), particle decay rate (k, 0.20 +/- 0.16 hr-1), and particle infiltration (Finf, 0.65 +/- 0.21) for each of the 44 residences. All of these parameters showed seasonal differences. The Finf estimates agree well with those estimated from the sulfur-tracer method (R2=0.78). The Finf estimates also showed robust and expected behavior when compared against known influencing factors. Among our study residences, outdoor-generated particles accounted for an average of 79 +/- 17% of the indoor PM concentration, with a range of 40 to 100% at individual residences. Although estimates of P, a, and k for individual residences may be unstable due to the limited capability of the non-linear model to simultaneously solve three unknowns, the recursive model provides a useful technique for estimating P and k in situations where air exchange rate can be measured.
The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under assistance agreement number CR827177 to the University of Washington. It has been subjected to Agency review and approved for publication.

JOURNAL Particle Concentrations in Inner-City Homes of Children With Asthma: the Effects of Smoking, Cooking, and Outdoor Pollution 07/01/2003
Wallace, L A., H. Mitchell, G. O'Connor, L Neas, M. Lippmann, M. Kattan, J. Koenig, J. Stout, B. Vaughn, D. Wallace, M. Walter, K. Adams, AND L. J. Liu. Particle Concentrations in Inner-City Homes of Children With Asthma: the Effects of Smoking, Cooking, and Outdoor Pollution. ENVIRONMENTAL HEALTH PERSPECTIVES 111(9):1265-1272, (2003).
Abstract: Inner-city children have high rates of asthma. Exposures to particles, including allergens, may cause or exacerbate asthma symptoms. As part of an epidemiologic study of inner-city children with asthma, continuous (10-min average) measurements of particle concentrations were made for 2-week periods in 294 homes drawn from seven cities. Measurements were made using an optical scattering device that is most sensitive to fine particles. The concentrations recorded by these devices were corrected to agree with colocated outdoor gravimetric PM2.5 monitors. Indoor concentrations in the homes averaged 27.7 (standard deviation = 35.9) μg/m3, compared with concurrent outdoor concentrations of 13.6 (7.5) μg/m3. A multivariate model indicated that outdoor particles penetrated indoors with an efficiency of 0.48 and were therefore responsible for only 25% of the mean indoor concentration. The major indoor source was smoking, which elevated indoor concentrations by 37 μg/m3 in the 101 homes with smokers. Other significant sources included frying, smoky cooking events, use of incense, and apartment housing, although the increases due to these events ranged only from 3 to 6 μg/m3. The 10-min averaging time allowed calculation of an average diurnal variation, showing large increases in the evening due to smoking and smaller increases at meal times due to cooking. Most of the observed variance in indoor concentrations was day to day, with roughly similar contributions to the variance from visit to visit and home to home within a city and only a small contribution made by variance among cities. The small variation among cities and the similarity across cities of the observed indoor air particle distributions suggest that sources of indoor concentrations do not vary considerably from one city to the next, and thus that simple models can predict indoor air concentrations in cities having only outdoor measurements.

JOURNAL The Effects of the Coastal Environment on the Atmospheric Mercury Cycle 06/21/2003
Malcolm, E. G., G. J. Keeler, AND M S. Landis. The Effects of the Coastal Environment on the Atmospheric Mercury Cycle. JOURNAL OF GEOPHYSICAL RESEARCH 108(D12):ACH4-1 to ACH4-9, (2003).
Abstract: Atmospheric mercury (Hg) species were investigated on the East Coast of Florida during June 2000. The site was impacted by air mass transport from the Atlantic Ocean and Southern Florida. Periods with atmospheric transport from the Atlantic were characterized by low concentrations of elemental gaseous Hg and inorganic divalent reactive gaseous Hg (RGM), demonstrating that the marine boundary layer was not a significant source of RGM to this coastal site as previous researchers have hypothesized. When anthropogenic impacts were observed at the site, indicated by elevated concentrations of gases including HNO3 and SO2, RGM concentrations had higher daytime maximums. Particulate phase Hg concentrations were higher than can be explained by sea spray alone, as determined by chemical analysis of the seawater, suggesting that gaseous Hg is diffusing to the sea salt aerosol. Although atmospheric Hg concentrations were not elevated, the observed scavenging of Hg gases by sea salt aerosols indicates that Hg may be rapidly cycled at the atmosphere-ocean interface between gaseous, aerosol and oceanic forms. Deposition of aerosol enriched in Hg via this process may constitute a significant global mercury flux to the oceans.
This work has been funded wholly or in part by the U.S. Environmental Protection Agency Office of Research and Development. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

JOURNAL Comparison of Immunoassay and Gas Chromatography/Mass Spectrometry for Measurement of Polycyclic Aromatic Hydrocarbons in Contaminated Soil 06/11/2003
Chuang, J. C., Y. L. Chou, N. Junod, J. K. Finegold, N. K. Wilson, AND J M. Van Emon. Comparison of Immunoassay and Gas Chromatography/Mass Spectrometry for Measurement of Polycyclic Aromatic Hydrocarbons in Contaminated Soil. ANALYTICA CHIMICA ACTA 486(1):31-39, (2003).
Abstract: Polycyclic aromatic hydrocarbons (PAHs) are frequently encountered in the environment and may pose health concerns due to their carcinogenicity. A commercial enzyme-linked immunosorbent assay (ELISA), was evaluated as a screening method for monitoring PAHs at contaminated sites. The ELISA was a Carcinogenic PAH (C-PAH) RaPID@ assay testing kit that cross-reacts with several PAHs and utilizes benzo[a]pyrene (BaP) as a calibrator. Soil samples were extracted with 50% acetone in dichloromethane (DCM) for analysis by ELISA and gas chromatography/mass spectrometry (GC/MS). The overall method precision was within plus/minus 30% for ELISA and within plus/minus 20% for GC/MS. Recovery data for spiked soils ranged from 46 to 140% for BaP as determined by ELISA. Recoveries of the GC/MS surrogate standards, 2-fluorobiphenyl and chrysene, were greater than 70%. The GC/MS procedure detected a total of 19 priority PAHs (2- to 6-ring PAHs) including seven probable human carcinogens (4- to 6-ring B2-PAHs). The ELISA results were compared to GC/MS summation results for the total 19 target PAHs as well as for the subset of the seven B2-PAH compounds. For all soil samples, the PAH concentrations derived from ELISA were greater than the sum of B2 PAH concentrations obtained by GC/MS. ELISA determinations were also frequently greater than the results obtained by GC/MS for the total 19 PAH compounds. This discrepancy can be expected, since the ELISA is a screening assay for the detection of several related PAHs while the GC/MS procedure detects priority PAH compounds. Thus, only a subset of PAHs (e.g., 19 PAHs) in the soil samples were measured by GC/MS while additional PAHs, including alkylated PAHs, and PAH derivatives have been demonstrated to be cross reactive in the C-PAH ELISA. Results of paired tests show that the PAH data from ELISA and GC/MS methods are significantly different (p <0.001), but highly correlated. The ELISA data had a strong positive relationship with the GC/MS summation data for the B2 PAHs as well as for the 19 PAHs targeted by the GC/MS method. Results indicate that the ELISA may be useful as a broad screen for monitoring PAHs in environmental samples.
This work was funded by EPA contracts 68-C5-0075 and 68-D-99-011. This paper has been reviewed in accordance with the US Environmental Protection Agency's peer and administrative review policies and approved for publication. Mention of trade names and commercial products does not constitute endorsement or recommendation for use.


JOURNAL ELISA Measurement of Stachylysin in Serum to Quantify Human Exposures to the Indoor Mold Stachybotrys Chartarum 06/01/2003
Van Emon, J M., A W. Reed, I. Yike, AND S J. Vesper. ELISA Measurement of Stachylysin in Serum to Quantify Human Exposures to the Indoor Mold Stachybotrys Chartarum. JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL MEDICINE 45(6):582-591, (2003).
Abstract: Problem- To develop a measurable indicator of human exposure to Stachybotys chartarum.
Methods- Antibodies were produced against the hemolytic agent stachylysin obtained from the mold S. chartarum. These antibodies were used to develop two enzyme-linked immunosorbent assay (ELISA) methods for the analysis of stachylysin in human and rat sera and environmental samples.

Results- Stachylysin was measured in rat pups that received nasal instillations of S. chartarum conidia but not in control rat serum. Stachylysin in the serum of five human adults exposed to S. chartarum in water damaged environments was 371 ng/mL but none was detected in the control serum. Stachylysin was also quantified in spore, wallboard, mycelial and dust samples.

Conclusions-The measurement of stachylysin may be a useful indicator in assessing human exposure to S. chartarum and in determining the presence of this indoor mold.

The U.S. Environmental Protection Agency (EPA) through its Office of Research and Development, funded and collaborated in the research described here. It has been subjected to the Agency's peer review and has been approved as an EPA publication. Mention of trade names or commercial products does not constitute endorsement or recommendation by the EPA for use.

JOURNAL A Fluorescence Based Assay for Dna Damage Induced By Styrene Oxide 06/01/2003
Ramanathan, K AND K R. Rogers. A Fluorescence Based Assay for Dna Damage Induced By Styrene Oxide. SENSORS & ACTUATORS B 91(1-3):205-210, (2003).
Abstract: A rapid and simple assay to detect DNA damage to calf thymus DNA caused by styrene oxide (SO) is reported. This assay is based on changes observed in the melting and annealing behavior of the damaged DNA. The melting annealing process was monitored using a fluorescence indicator dye PicoGreen (R) (PG) that increases its fluorescence when bound to double stranded DNA. The assay response was monitored with varying concentrations of SO, incubation temperature, incubation time and salt concentration. Sample volumes of 10 ul containing 100 ng/ml DNA were required for this assay. The error in measurement was between 5 and 7%.
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development (ORD), has funded this research. It has been subject to the EPA's peer and administrative review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation by EPA for use.

JOURNAL Exposure Assessment of Particulate Matter for Susceptible Populations in Seattle 06/01/2003
Liu, L. S., M. Box, D. Kalman, J. Kaufman, J. Koenig, T. Larson, T. Lumley, L. Sheppard, AND L A. Wallace. Exposure Assessment of Particulate Matter for Susceptible Populations in Seattle. ENVIRONMENTAL HEALTH PERSPECTIVES 111(7):909-918, (2003).
Abstract: In this article we present results from a 2-year comprehensive exposure assessment study that examined the particulate matter (PM) exposures and health effects in 108 individuals with and without chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD), and asthma. The average personal exposures to PM with aerodynamic diameters < 2.5 um (PM2.5) were similar to the average outdoor PM2.5 concentrations but significantly higher than the average indoor concentrations. Personal PM2.5 exposures in our study groups were lower than those reported in other panel studies of susceptible populations. Indoor and outdoor PM2.5, PM10 (PM with aerodynamic diameters < 10 um), and the ratio of PM2.5 to PM10 were significantly higher during the heating season. The increase in outdoor PM10 in winter was primarily due to an increase in the PM2.5 fraction. A similar seasonal variation was found for personal PM2.5. The high-risk subjects in our study engaged in an equal amount of dust-generating activities compared with the healthy elderly subjects. The children in the study experienced the highest indoor PM2.5 and PM10 concentrations. Personal PM2.5 exposures varied by study group, with elderly healthy and CHD subjects having the lowest exposures and asthmatic children having the highest exposures. Within study groups, the PM2.5 exposure varied depending on residence because of different particle infiltration efficiencies. Although we found a wide range of longitudinal correlations between central-site and personal PM2.5 measurements, the longitudinal r closely related to the particle infiltration efficiency. PM2.5 exposures among the COPD and CHD subjects can be predicted with relatively good power with a microenvironmental model composed of three microenvionments. The prediction power is the lowest for the asthmatic children.
This report has been subjected to U.S. EPA review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

JOURNAL Aggregate Exposures of Nine Preschool Children to Persistent Organic Pollutants at Day Care and at Home 05/01/2003
Wilson, N. K., J. C. Chuang, C. Lyu, R. Menton, AND M K. Morgan. Aggregate Exposures of Nine Preschool Children to Persistent Organic Pollutants at Day Care and at Home. JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY 13(3):187-202, (2003).
Abstract: In the summer of 1997, we measured the aggregate exposures of nine preschool children, ages two to five years, to a suite of organic pesticides and other persistent organic pollutants that are commonly found in the home and school environment. The children attended either of two child day care centers in the Raleigh-Durham-Chapel Hill area of North Carolina and were in day care at least 25 hr/wk. Over a 48-hr period, we sampled indoor and outdoor air, play area soil and floor dust, as well as duplicate diets, hand surface wipes, and urine for each child at day care and at home. Our target analytes were several polycyclic aromatic hydrocarbons (PAH), organochlorine pesticides, and polychlorinated biphenyls (PCB); two organophosphate pesticides (chlorpyrifos and diazinon), the lawn herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), three phenols (pentachlorophenol, nonyl phenols, and bisphenol-A), 3,5,6-trichloro-2-pyridinol (TCP), and two phthalate esters (benzylbutyl and dibutyl phthalate). In urine, our target analytes were hydroxy-PAH, TCP, 2,4-D, and pentachlorophenol. To allow estimation of each child's aggregate exposures over the 48-hr sampling period, we also used time-activity diaries, which were filled out by each child's teacher at day care and the parent or other primary caregiver at home. In addition, we collected detailed household information that related to potential sources of exposure, such as pesticide use or smoking habits, through questionnaires and field observation. We found that the indoor exposures were greater than those outdoors, that exposures at day care and at home were of similar magnitudes, and that diet contributed greatly to the exposures. The children's potential aggregate doses, calculated from our data, were generally well below established reference doses (RfDs) for those compounds for which RfDs are available.
This work has been funded wholly or in part by the United States Environmental Protection Agency under contract #68-D4-0023 to Battelle. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

JOURNAL Use of Agricultural Pesticides and Prostate Cancer Risk in the Agricultural Health Study Cohort 05/01/2003
Alavanja, M., C. Samanic, M. Dosemeci, J. H. Lubin, R. Tarone, C. Lynch, C. Knott, K W. Thomas, J. A. Hoppin, J. Barker, J. Coble, D. Sandler, AND A. Blair. Use of Agricultural Pesticides and Prostate Cancer Risk in the Agricultural Health Study Cohort. AMERICAN JOURNAL OF EPIDEMIOLOGY 157(9):800-814, (2003).
Abstract: The authors examined the relationship between 45 common agricultural pesticides and prostate cancer incidence in a prospective cohort study of 55,332 male pesticide applicators from Iowa and North Carolina with no prior history of prostate cancer. Data were collected by means of self-administered questionnaires completed at enrollment (1993-1997). Cancer incidence was determined through population-based cancer registries from enrollment through December 31,1999. A prostate cancer standardized incidence ratio was computed for the cohort. Odds ratios were computed for individual pesticides and for pesticide use patterns identified by means of factor analysis. A prostate cancer standardized incidence ratio of 1.14 (95% confidence interval: 1.05-1.24) was observed for the Agricultural Health Study cohort. Use of chlorinated pesticides among applicators over 50 years of age and methyl bromide use were significantly associated with prostate cancer risk. Several other pesticides showed a significantly increased risk of prostate cancer among study subjects with a family history of prostate cancer but not among those with no family history. Important family history-pesticide interactions were observed.
The United States Environmental Protection Agency through its Office of Research and Development collaborated in the research described here. It has been subjected to Agency review and approved for publication.

JOURNAL Overview of the 1999 Atlanta Supersite Project 04/15/2003
Solomon, P A., W. L. Chameides, R. W. Weber, A. M. Middlebrook, C. S. Kiang, A. G. Russell, A. G. Butler, B. Turpin, D. Mikel, R. Scheffe, E. Cowling, E. Edgerton, J. St. John, J. Jansen, P. McMurry, S. Hering, AND T. Bahadori. Overview of the 1999 Atlanta Supersite Project. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 108(D-7):SOS1-1 to SOS 1-24, (2003).
Abstract: This paper presents an overview of the 1999 Atlanta Supersite Project coordinated through the Southern Oxidants Study and the Georgia Institute of Technology (GIT) and funded by the US EPA along with other sponsors who provided in-kind support primarily through existing studies. The Atlanta Supersites Project was located at the existing SEARCH/ARIES site on Jefferson St. in NW Atlanta, GA. The primary objective of the Atlanta Supersites Project was to evaluate and compare advanced measurement methods for particulate matter mass and its components. Methods included filter/denuder based time-integrated or discrete samplers, a variety of semi-continuous methods measuring mass, its major components (sulfate, nitrate, ammonium, organic carbon, elemental carbon, trace elements) and gas phase precursors, and for the first time ever, a comparison among particle mass spectrometers, four in total. These data were complemented by meteorological data as well as gas phase criteria pollutant measurements and other supplemental data, such as particle physical properties, VOC, oxygenated VOC, and NOy. The primary and supplemental data also were used to better understand the formation and accumulation of PM in Atlanta and to better understand source-receptor relationships. This paper overviews the study, summarizing objectives, the site and measurements, the relative reference data used for comparisons, overviews the meteorological and chemical characteristics of pollution in Atlanta during the study, puts the study in context of Atlanta and the Southeast US, and finally summarizes the key findings from the over 30 publications published, submitted, or in preparation. This paper also provides as complete a list as is currently available of those publications. Others certainly will be emerging over time. The comprehensive database is available through the Atlanta Supersites Project web site sponsored by GIT (http://www-wlc.eas.gatech.edu/supersite/).
The United States Environmental Protection Agency through its Office of Research and Development funded and managed or partially funded and collaborated in the research described here under Assistance Agreement No. CR824849 to the Georgia Institute of Technology in Atlanta, GA. It has been subjected to Agency review and approved for publication.

JOURNAL Preface to Special Section: Southern Oxidants Study 1999 Atlanta Supersite Project (Sos3) 04/15/2003
Solomon, P A., E. Cowling, AND R. Weber. Preface to Special Section: Southern Oxidants Study 1999 Atlanta Supersite Project (Sos3). JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 108(D7):SOS 0-1, (2003).
Abstract: The Atlanta Supersites Project consisted of a one-month intensive field program to compare advanced methods for measurement of PM2.5 mass, chemical composition, including single particle composition in real-time, and aerosol precursor species. The project was the first of EPA's PM Supersites Program field research efforts and provided valuable information to follow-on Supersites Program projects conducted during 2000-2004. Results from the study also provided insights into source-receptor relationships impacting the site and atmospheric chemical and physical processes that result in PM accumulation in Atlanta, GA. The Atlanta Supersites Project was funded by the U.S. Environmental Protection Agency through a cooperative agreement (EPA #CR824849) with the Southern Oxidants Study under the direction of Dr. Ellis Cowling. The project was managed by faculty in the School of Earth and Atmospheric Sciences at Georgia Tech with Dr. William Chameides as principal investigator. The intensive field measurements program took place during the month of August 1999 at the Jefferson St. site adjacent to the Georgia Power building in NW metro Atlanta. Since 1998, this same site has been operated as part of SEARCH and ARIES programs funded by EPRI, the Southern Company, and Georgia Power and maintains a measurement program of many important atmospheric variables that will continue to provide insight into possible adverse health effects associated with exposure to ambient urban PM concentrations. SEARCH provided extensive spatial information about PM and related variables throughout the southeastern US, while other coordinated efforts, e.g., ASACA, provided valuable spatial information within the Atlanta metropolitan area. The papers within this special issue provide details and intercomparions of results from filter based time-integrated aerosol measurements, continuous or semi-continuous methods for mass and PM components and precursors, and for the four particle mass spectrometers operated during the study. Other papers include aerosol characterization and chemistry, atmospheric modeling studies, and results from ASACA. The overview paper summarizes the study, its results, and provides a listing of all publications associated with the Atlanta Supersites Project that were known at the time of its submission to this special issue of Journal of Geophysical Research-Atmospheres.
The United States Environmental Protection Agency through its Office of Research and Development(funded and managed or partially funded and collaborated in) the research described here under (Assistance agreement No. CR824849) to the Georgia Institute of Technology in Atlanta, GA. It has been subjected to Agency review and approved for publication.

JOURNAL A Comparison of Particle Mass Spectrometers During the 1999 Atlanta Supersites Experiment 04/01/2003
Middlebrook, A. M., D. M. Murphy, S. H. Lee, D. S. Thomson, K. A. Prather, R. J. Wenzel, D. Y. Liu, D. J. Phares, K. P. Rhoads, A. S. Wexler, M. V. Johnston, J. L. Jiminez, J. T. Jayne, D. R. Worsnop, I. Yourshaw, J. H. Seinfeld, R. C. Flagan, S. V. Hering, R. J. Weber, P. Jongejan, J. Slanina, AND P. K. Dasgupta. A Comparison of Particle Mass Spectrometers During the 1999 Atlanta Supersites Experiment. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 108(D7):SOS 12-1 - 12-13, (2003).
Abstract: During the Atlanta SuperSite Experiment, four particle mass spectrometers were operated together for the first time: NOAA's PALMS (Particle Analysis by Laser Mass Spectrometry), U. C. Riverside's ATOFMS (Aerosol Time-of-Flight Mass Spectrometry), U. Delaware's RSMS-II (Rapid Single-Particle Mass Spectrometer II), and Aerodyne's AMS (Aerosol Mass Spectrometer). Although these mass spectrometers are generally classified as similar instruments, they clearly have different characteristics due to their unique designs. One primary difference is related to the volatilization/ionization method: PALMS, ATOFMS, and RSMS-II utilize laser desorption/ionization whereas particles in the AMS instrument are volatilized by impaction onto a heated surface with the resulting components ionized by electron impact. Thus, mass spectral data from the AMS are representative of the ensemble of particles sampled and those from the laser-based instruments are representative of individual particles. A main difference among the laser-based mass spectrometers is that the RSMS-II instrument can obtain size-resolved single particle composition information for particles with aerodynamic diameters as small as 15 nm. The minimum sizes analyzed by ATOFMS and PALMS are about 0.2 and 0.35 um, respectively, in aerodynamic diameter. Furthermore, PALMS, ATOFMS, and RSMS-II use different laser ionization conditions. Despite these differences, the laser-based instruments found similar individual particle classifications and their relative fractions among comparable sized particles from Atlanta were broadly consistent. Finally, the AMS measurements of the nitrate/sulfate mole ratio were highly correlated with the quantitative semi-continuous measurements (r 2 = 0.93). In contrast, the PALMS nitrate/sulfate ion ratios were only moderately correlated (r 2 ~ 0.7).
This work was funded in part by the U.S. EPA, NARSTO (Southern Oxidants Study), and Georgia Institute of Technology (SCISSAP).

JOURNAL A Fluorescence Based Assay for Dna Damage Induced By Radiation, Chemical Mutagens and Enzymes 04/01/2003
Ramanathan, K, R. Gary, A. B. Apostol, AND K R. Rogers. A Fluorescence Based Assay for Dna Damage Induced By Radiation, Chemical Mutagens and Enzymes. CURRENT APPLIED PHYSICS 3(2-3):99-106, (2003).
Abstract: A simple and rapid assay to detect DNA damage is reported. This novel assay is based on changes in melting/annealing behavior and facilitated using certain dyes that increase their fluorescence upon association with double stranded (ds)DNA. Damage caused by ultraviolet (UV) radiation, chemical mutagens or restriction enzymes produced an assay response. UV radiation at 254 nm (approximating UV-C) and 360 nm (approximating UV-A) were used to induce the damage in dsDNA. Chemical damage was induced using several compounds with known effects on nucleic acids. Restriction enzymes Hind III, Msp1, Sau 3A1 were used to cut the plasmid (pUC19) at specific sequences in addition to the nonspecific endonuclease DNase I. The effects of these types of damage on repeated melting and annealing of dsDNA were observed in real time using several fluorescence indicator dyes. Low concentrations of dsDNA (between 10 and 100 ng/mL) and small volumes (20 uL) were required for this assay. Repeated measures yielded a coefficient of variation of 2% (CV%). In addition to measuring various DNA damaging agents, the potential application of this assay to study the efficiency of various sun blocking agents against UV-induced DNA damage is discussed.
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development (ORD), funded this research. It has been subjected to the EPA's peer and administrative review and approved for publication.

JOURNAL Comparison of Integrated Samplers for Mass and Composition During the 1999 Atlanta Supersites Project 03/13/2003
Solomon, P A., K. Baumann, E. Edgerton, R. Tanner, D J. Eatough, W. Modey, H. Marin, D. Savoie, S. Natarajan, M. B. Meyer, AND G A. Norris. Comparison of Integrated Samplers for Mass and Composition During the 1999 Atlanta Supersites Project. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 108(D7):SOS 11-1 - SOS 11-26, (2003).
Abstract: The first of EPA's Particulate Matter (PM) Supersites projects was established in Atlanta, GA during the summer of 1999 in conjunction with the Southern Oxidants Study. The short-term primary focus was a one month intensive field campaign to evaluate advanced PM measurement methods for measuring PM mass and the chemical and physical properties of PM. Long-term objectives are being met through coordination and cooperation with existing programs in Atlanta and the southeastern U.S. Three categories of PM instruments were deployed during August 1999: time-integrated or discrete filter based methods like those used in EPA's PM2.5 Chemical Speciation Network; continuous or semi-continuous species specific methods, most of which are still in development; and single particle mass spectrometers, the most advanced methods looking at the chemical composition of single particles. The focus of this paper is on comparison of the discrete filter based methods. Samples were collected by 12 discrete filter-based samplers on an every other day basis during the study period at the Jefferson Street SEARCH (Southeastern Aerosol Research and Characterization) study site. Samples were analyzed for PM2.5 mass, sulfate, nitrate, ammonium, organic carbon, elemental carbon, and trace elements, the latter by XRF. Samplers used a variety of filters, denuder-filter combinations in the case of nitrate and organic carbon, particle size fractionating devices, and flow rates. Ambient concentrations for most species were sufficiently above detection limits for testing comparability among samplers with nitrate being the most notable exception for the major components having an average reported value of 0.5 ug/m3. Several trace species, e.g., As and Pb, also were often below limits of detection of the analysis method.
Results indicate real differences exist among the samplers tested for most species, with sulfate and ammonium being the exceptions, under the conditions tested. Differences are due to sampler design and in the case of elemental carbon also due to the use of different chemical analysis methods. Comparability among most of the samplers for a given species was: mass (plus/minus 20%); sulfate (plus/minus 10%); nitrate (plus/minus 30-35%); ammonium (plus/minus 10-15%); organic carbon either with or without denuders (plus/minus 20%) or including samplers both with and without denuders (plus/minus 35-45%); elemental carbon (plus/minus 20 to +/- 200%, the latter if different analysis methods are used); and minor and trace elements (plus/minus 20-30%). A net organic carbon sampling artifact on quartz-fiber filters was estimated from the comparison of denuded versus undenuded samples and is in the range of 1-4 ug/m3.

The US EPA through its Office of Research and Development (funded and managed or partially funded and collaborated in) the research described here under Contract # 68-D-00-206 to Research Triangle Institute. It has been subjected to Agency review and approved for publication.

JOURNAL Source Apportionment of Phoenix PM2.5 Aerosol With the Unmix Receptor Model 03/01/2003
Lewis, C W., G A. Norris, T L. Conner, AND R. C. Henry. Source Apportionment of Phoenix PM2.5 Aerosol With the Unmix Receptor Model. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION 53(3):325-338, (2003).
Abstract: The multivariate receptor model Unmix has been used to analyze a 3-yr PM2.5 ambient aerosol data set collected in Phoenix, AZ, beginning in 1995. The analysis generated source profiles and overall percentage source contribution estimates (SCE) for five source categories: gasoline engines (33 plus/minus 4%), diesel engines (16 plus/minus 2%), secondary SO42- (19 plus/minus 2%), crustal/soil (22 plus/minus 2%), and vegetative burning (10 plus/minus 2%). The Unmix analysis was supplemented with scanning electron microscopy of a limited number of filter samples for information on possible additional low-strength sources. Except for the diesel engine source category, the Unmix SCEs were generally consistent with an earlier multivariate receptor analysis of essentially the same data using the Positive Matrix Factorization model. This article provides the first demonstration for an urban area of the capability of the Unmix receptor model.
The United States Environmental Protection Agency through its Office of Research and Development funded and managed the research described here. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

JOURNAL Distributions, Associations, and Partial Aggregate Exposure of Pesticides and Polynuclear Aromatic Hydrocarbons in the Minnesota Children's Pesticide Exposure Study (Mncpes) 03/01/2003
Clayton, C. A., E. D. Pellizzari, R. W. Whitmore, J J. Quackenboss, J. L. Adgate, AND K. Sexton. Distributions, Associations, and Partial Aggregate Exposure of Pesticides and Polynuclear Aromatic Hydrocarbons in the Minnesota Children's Pesticide Exposure Study (Mncpes). INTERNATIONAL JOURNAL OF EXPOSURE ANALYSIS AND ENVIRONMENTAL EPIDEMIOLOGY 13(2):100-111, (2003).
Abstract: The Minnesota Children's Pesticide Exposure Study (MNCPES) provides exposure, environmental, and biologic data relating to multi-pathway exposures of children for four primary pesticides (chlorpyrifos, malathion, diazinon, and atrazine), 14 secondary pesticides, and 13 polynuclear aromatic hydrocarbons (PAHs). Monitoring was performed on a probability sample of 102 children aged 3-12 in Minneapolis/St. Paul and in a nearby non-urban area (Goodhue and Rice counties). This paper provides estimated distributions of this population's exposures and exposure-related measurements and examines associations among the various measures via rank (Spearman) correlations. In addition, it provides some aggregate and cumulative exposure estimates for pesticides, and compares the relative intakes from inhalation and dietary ingestion. Intakes for the four primary pesticides appeared to come principally from the ingestion rather than the inhalation route; this was clearly true for chlorpyrifos but was less certain for the other three primary pesticides due to their higher degree of non-detects. Solid food rather than beverages was clearly the main contributor to the ingestion intake. Despite the dominance of the ingestion route, the urinary metabolite of chlorpyrifos exhibited a stronger association with the air measurements than with the dietary measures. Personal air samples exhibited strong rank correlations with indoor air samples for chlorpyrifos, malathion, and diazinon (0.81, 0.51, and 0.62, respectively), while personal-air atrazine levels correlated well with outdoor levels (0.69); diazinon personal air levels also correlated well with outdoor levels (0.67). For the PAHs, many significant associations were evident among the various air samples and for the air samples with the dust samples, especially for those compounds with consistently high percent measurable values (particularly fluoranthene, phenanthrene, and pyrene).
The EPA, through its Office of Research and Development (ORD), partially funded and collaborated in the research described here under assistance agreement number CR821902-01-0 to the Research Triangle Institute and by STAR grant R825283 to the University of Minnesota. It was also partially supported by a grant from the Legislative Commission on Minnesota Resources. This manuscript has been peer reviewed by EPA and approved for publication.


JOURNAL Continuous Measurement of Fine and Ultrafine Particulate Matter, Criteria Pollutants and Meteorological Conditions in Urban El Paso, Texas 02/01/2003
Noble, C. A., S Mukerjee, M Gonzales, C. Rodes, P. A. Lawless, S. Natarajan, E. A. Myers, G A. Norris, L. Smith, A H. Ozkaynak, AND L Neas. Continuous Measurement of Fine and Ultrafine Particulate Matter, Criteria Pollutants and Meteorological Conditions in Urban El Paso, Texas. ATMOSPHERIC ENVIRONMENT 37(6):827-840, (2003).
Abstract: Continuous measurements of aerosol size distributions were made in El Paso, TX, for a period in winter 1999. Size distribution measurements were performed at two urban locations in El Paso using two pairs of the scanning mobility particle sizer and the aerodynamic particle sizer. Complementary measurements also were performed for gas phase pollutants (CO, NO, NO2, O3) and meteorological conditions. Throughout the study, the mean ultrafine particle (those smaller than 0.1 um in diameter) number concentration was 14,400 particles cm-3. There was a significant correlation between CO and both ultrafine and accumulation mode (those between 0.1 and 1 um in diameter) particle count, with the Pearson correlation coefficient (r) values of 0.81 and 0.87, respectively. The correlation between NO and both ultrafine and accumulation mode particle count is also significant, but not as strong as the correlation of CO and the particle concentrations. Most pollutants were found to vary on diurnal cycles and to follow one of two different trends, either vehicular traffic schedules or sunlight intensity. Wind direction was found to have an influence not only on pollutant concentrations, but also on the correlation between pollutants. With southerly winds, CO, NO and NO2 concentrations were 25-140% greater than when the wind was coming from the north. Likewise, ultrafine and accumulation mode particle concentrations were approximately 100% greater for southerly than for northerly winds.
The US Environmental Protection Agency through its Office of Research and Development funded and managed the research described here under contract 68-D-99-012 to Research Triangle Institute and contract 68-D0-0206 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

JOURNAL Intercomparison of Near Real-Time Monitors of PM2.5 Nitrate and Sulfate at the U.S. Environmental Protection Agency Atlanta Supersite 01/29/2003
Weber, R., D. Orsini, Y. Duan, K. Baumann, C. S. Kiang, W. L. Chameides, Y. N. Lee, F. Brechtel, P. Klotz, P. Jongejan, H. ten Brink, J. Slanina, C. B. Boring, Z. Genfa, P. Dasgupta, S. Hering, M. Stolzenburg, D. D. Dutcher, E. Edgerton, B. Hartsell, P A. Solomon, AND R. Tanner. Intercomparison of Near Real-Time Monitors of PM2.5 Nitrate and Sulfate at the U.S. Environmental Protection Agency Atlanta Supersite. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 108(D7):9-1 to 9-13, (2003).
Abstract: Five new instruments for semi-continuous measurements of fine particle (PM2.5) nitrate and sulfate were deployed at the Atlanta Supersite Experiment during an intensive study in August 1999. The instruments measured bulk aerosol chemical composition at rates ranging from every 5 minutes to once per hour. The techniques included a filter sampling system with automated water extraction and on-line ion chromatographic analysis (IC), two systems that directly collected particles into water for IC analysis, and 2 techniques that converted aerosol nitrate or sulfate either catalytically or by flash vaporization to gaseous products that were measured with gas analyzers. During the one-month study 15-minute integrated nitrate concentrations were low ranging from about 0.1 to 3.5 ug m-3 with a mean value of 0.5 ug m-3. Ten-minute integrated sulfate concentrations varied between 0.3 and 40 ug m-3 with a mean of 14 ug m-3. By the end of the one-month study most instruments were in close agreement with r-squared values between instrument pairs typically ranging from 0.7 to 0.94. Based on comparison between individual semi-continuous devices and 24-h integrated filter measurements, most instruments were within 20 to 30% for nitrate (~0.1-0.2 ug m-3) and 10 to 15% for sulfate (1-2 ug m-3). Within 95% confidence intervals, linear regression fits suggest no biases existed between the semi-continuous techniques and the 24-h integrated filter measurements of nitrate and sulfate, however, for nitrate, the semi-continuous intercomparisons showed significantly less variability than intercomparisons amongst the 24-h integrated filters.
The United States Environmental Protection Agency through its Office of Research and Development (funded and managed or partially funded and collaborated in) the research described here under (CR824849) to the Georgia Institute of Technology. It has been subjected to Agency review and approved for publication.

JOURNAL Semi-Continuous Aerosol Carbon Measurements: Comparison of Atlanta Supersite Measurements 01/21/2003
Lim, H. J., B. Turpin, E. Edgerton, S. Hering, G. Allen, H. Maring, AND P A. Solomon. Semi-Continuous Aerosol Carbon Measurements: Comparison of Atlanta Supersite Measurements. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES 108(D7):SOS7-1 to SOS7-12, (2003).
Abstract: An intensive field campaign of the Atlanta Supersite Experiment was carried out at a ground-based measurement site on Jefferson Street in midtown Atlanta, GA, from 3 August to 1 September, 1999. This paper examines the semi-continuous particulate organic and elemental measurements that were made as a part of the experiment. Measurements were made using a Rutgers University/Oregon Graduate Institute in situ thermal-optical carbon analyzer, Rupprecht and Patashnick 5400 ambient carbon particulate monitor, Radiance Research particle soot absorption photometer, Aerosol Dynamics flash vaporization carbon analyzer, and Magee Scientific AE-16 aethalometer. The "intersampler precision" with which semi-continuous particulate TC, OC, and EC were measured is 7, 13 and 26%, expressed as pooled coefficients of variation of 2, 3, and 4 instruments, respectively. Correlations between pairs of OC measurements are moderate (R2 = 54-73%) and correlations between pairs of EC measurements are high (R2= 74-97%). Differences in reported OC concentrations are small compared to differences in EC concentrations; intersampler EC concentration differences result from differences 1) in the operational definitions of OC and EC, 2) in the calibration of optical instruments, and 3) because EC values are closer to limits of detection. This agreement between semi-continuous samplers is quite good, especially in light of previous particulate carbon comparisons. Reasons for measurement differences and benefits of automated, time-resolved measurements are discussed.
This publication was funded in part by the Electric Power Research Institute. The United States Environmental Protection Agency through its Office of Research and Development partially funded and collaborated in the research described here under assistance agreement number CR824849 to Georgia Institute of Technology. It has been subject to Agency review and approved for publication.

JOURNAL Short-Term Temporal Variation in PM2.5 Mass and Chemical Composition During the Atlanta Supersite Experiment, 1999 01/02/2003
Weber, R., D. Orsini, J. St. John, M. Bergin, C. S. Kiang, M. Chang, C. M. Carrico, Y. N. Lee, P. Dasgupta, J. Slanina, B. Turpin, E. Edgerton, S. Hering, G. Allen, P A. Solomon, AND W. L. Chameides. Short-Term Temporal Variation in PM2.5 Mass and Chemical Composition During the Atlanta Supersite Experiment, 1999. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION 53(1):84-91, (2003).
Abstract: Measurements in urban Atlanta of transient aerosol events in which PM2.5 mass concentrations rapidly rise and fall over a period of 3-6 hr are reported. The data are based on new measurement techniques demonstrated at the U.S. Environmental Protection Agency (EPA) Atlanta Supersite Experiment in August 1999. These independent instruments for aerosol chemical speciation of NO3-, SO42- , NH4+, and organic and elemental carbon (OC and EC), reconstructed the observed hourly dry PM2.5 mass to within typically 20% or better. Data from the experiment indicated that transient PM2.5 events were ubiquitous in Atlanta and were typically characterized by a sudden increase of EC (soot) and OC in the early morning or SO42- in the late afternoon. The frequent temporal decoupling of these events provides insights into their origins, suggesting mobile sources in metro Atlanta as the main contributor to early morning PM2.5 and more regionally located point SO2 sources for afternoon PM2.5 events. The transient events may also have health implications. New data suggest that short-term PM2.5 exposures may lead to adverse health effects.1 Standard integrated filter-based techniques used in PM2.5 compliance monitoring networks and in most past PM2.5 epidemiological studies collect samples over 24-hour periods and thus are unable to capture these transient events. Moreover, health-effects studies that focus on daily PM2.5 mass alone cannot evaluate the health implications of the unique and variable chemical properties of these episodes.
The United States Environmental Protection Agency through its Office of Research and Development funded and managed or partially funded and collaborated in the research described here under assistance agreement number CR824 849 to Georgia Institute of Technology. This work has been subjected to agency review and approved for publication.

JOURNAL Impact of Organic Compounds on the Concentrations of Liquid Water in Ambient PM2.5 01/01/2003
Speer, R E., E O. Edney, AND T E. Kleindienst. Impact of Organic Compounds on the Concentrations of Liquid Water in Ambient PM2.5. JOURNAL OF AEROSOL SCIENCE AND TECHNOLOGY 34(1):63-77, (2003).
Abstract: A field study was undertaken during the summer of 2000 to assess the impact of the presence of organic compounds on the liquid water concentrations of PM2.5 samples. The selected site, located in Research Triangle Park, North Carolina, was in a semi-rural environment with expected impacts from both biogenic and anthropogenic emissions. Eight samples, collected on Teflon filters over 48-h periods, were analyzed for their liquid water concentrations by using a beta gauge to measure the change in PM2.5 mass on the filter as a function of relative humidity in a humidity-controlled environmental chamber. The filter samples were also analyzed for mass, elemental and organic carbon, and anionic concentrations. For six of the eight samples, the measured liquid water concentrations exceeded those predicted from the presence of the inorganic constituents. A relationship between the excess liquid water and the measured organic carbon mass was found, although the standard deviations associated with the measurements were large. Through modeling studies it was determined that, on average, about 80% of the liquid water in the PM2.5 could be accounted for by inorganic ions present, with the remaining 20% associated with organic compounds. The liquid water data were consistent with the presence of aqueous solutions supersaturated with respect to the inorganic ions in the aerosol.
The U.S. Environmental Protection Agency through its Office of Research and Development funded and collaborated in the research described here under Contract 68-D5-0049 to ManTech Environmental Technology, Inc. It has been subject to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

PRESENTATION Tampa Asthmatic Children's Study (Tacs) 12/17/2003
Stevens, C AND R W. Williams. Tampa Asthmatic Children's Study (Tacs). Presented at National Childrens Study Pilot Study, Atlanta, GA, December 17, 2003.
Abstract: The Tampa Asthmatic Children's Study (TACS) was a pilot research study to assess methodologies and research instruments needed for including asthma as a health outcome in the National Children's Study (NCS). This was one of a series of pilot studies focusing on (a) simple, cost effective methods for assessing environmental exposures relevant to asthma and (b) techniques for the early assessment of asthma-related health outcomes. This research project focused on the development of methods for understanding the factors that contribute to indoor concentrations and exposures to combustion related products (CRPs), particulate matter (PM) and select air toxics. The four-week study was performed in Tampa, FL during the months of October and November, 2002. The study involved repeated daily personal, residential, and ambient air pollution measurements for a cohort of nine asthmatic children, ranging in age from 1-5 years.
This work has been funded wholly by the United States Environmental Protection Agency's Office of Research and Development under contract #68-D-99-012 to the Research Triangle Institute International. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

PRESENTATION Methods Studies for the National Children's Study: Molecularly Imprinted Polymers 12/17/2003
Robertson, G L., S C. Hern, AND K R. Rogers. Methods Studies for the National Children's Study: Molecularly Imprinted Polymers. Presented at National Children's Study Assembly Meeting, Atlanta, GA, December 17, 2003.
Abstract: Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiological studies is often limited by time, budget, and compliance issues. Another problem which arises when determining the sources, routes, and pathways of exposure to pesticides and other chemicals is the lag time between collection of a sample and the receipt of the results.
Current methods which use laboratory analysis may take 30-60 days, or longer, to obtain results. This means that the source of exposure may be gone by the time it is discovered that the child has been exposed, given the relatively short half-lives of many compounds. Screening techniques could direct attention to the most highly exposed (to particular indicator compounds) population of children for which multiroute, multimedia monitoring would be of value. In addition, stratification of the study population (i.e., the majority of the environmental/biological samples collected from the "highly exposed population" of children) often is required, given the expense of multiroute, multimedia monitoring (numerous non-detect results are counterproductive in determining sources).

This project will be conducted as four concurrent subprojects. Three subprojects will be directed at (1) demonstrating field performance of a semipermeable membrane device (SPMD) to collect long-term integrated samples for semivolatile organics in air, (2) developing simple rapid methods for analyzing the SPMDs, and (3) developing rapid field or near field methods for analyzing chemical metabolites in urine. The fourth subproject will be a literature review to identify available but not currently used techniques for long-term integrated exposure measurements.

The U.S. Environmental Protection Agency (EPA) through its Office of Research and Development (ORD), contributed to the research described. This poster has been subjected to the EPA's peer and administrative review and has been approved for presentation.

PRESENTATION Use of Disposable Diapers to Collect Urine in Exposure Studies 12/17/2003
Fortmann, R. AND M. G. Nishioka. Use of Disposable Diapers to Collect Urine in Exposure Studies. Presented at National Children's Study Assembly Meeting, Atlanta, GA, December 17, 2003.
Abstract: Large studies of children's health as it relates to exposures to chemicals in the environment often require measurements of biomarkers of chemical exposures or effects in urine samples. But collection of urine samples from infants and toddlers is difficult. For large exposure studies, such as the National Children's Study (NCS), it is highly desirable to identify a low burden, low-cost method for collection of urine from infants and very young children. Disposable diapers that contain polyacrylate granules and fibers are the most widely used diapers for hygiene purposes. But their use to collect urine that can be analyzed for environmental contaminants and blomarker compounds has not been tested adequately.
This project consists of a laboratory study to evaluate a method for measuring biomarkers of current-use pesticides in urine samples collected with commercially-available disposable diapers. An initial set of tests will be performed to evaluate the feasibility of the proposed solvent extraction and gas chromatography/mass spectrometry (GC/MS) analysis method. If the initial tests demonstrate that the method is likely to provide acceptable performance, a more comprehensive set of tests will be performed to demonstrate if the disposable diapers are suitable for use in the NCS.

Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.


PRESENTATION Methods Studies for the National Children's Study: Semipermeable Membrane Device (Spmd) 12/17/2003
Robertson, G L., S C. Hern, AND K R. Rogers. Methods Studies for the National Children's Study: Semipermeable Membrane Device (Spmd). Presented at National Children's Study Assembly Meeting, Atlanta, GA, December 17, 2003.
Abstract: Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiological studies is often limited by time, budget, and compliance issues. Another problem which arises when determining the sources, routes, and pathways of exposure to pesticides and other chemicals is the lag time between collection of a sample and the receipt of the results.
Current methods which use laboratory analysis may take 30-60 days, or longer, to obtain results. This means that the source of exposure may be gone by the time it is discovered that the child has been exposed, given the relatively short half-lives of many compounds. Screening techniques could direct attention to the most highly exposed (to particular indicator compounds) population of children for which multiroute, multimedia monitoring would be of value. In addition, stratification of the study population (i.e., the majority of the environmental/biological samples collected from the "highly exposed population" of children) often is required, given the expense of multiroute, multimedia monitoring (numerous non-detect results are counterproductive in determining sources).

This project will be conducted as four concurrent subprojects. Three subprojects will be directed at (1) demonstrating field performance of a semipermeable membrane device (SPMD) to collect long-term integrated samples for semivolatile organics in air, (2) developing simple rapid methods for analyzing the SPMDs, and (3) developing rapid field or near field methods for analyzing chemical metabolites in urine. The fourth subproject will be a literature review to identify available but not currently used techniques for long-term integrated exposure measurements.

The U.S. Environmental Protection Agency (EPA) through its Office of Research and Development (ORD), contributed to the research described. This poster has been subjected to the EPA's peer and administrative review and has been approved for presentation.

PRESENTATION Data Collected in the EPA's National Exposure Research Laboratory's Field Measurement Studies to Evaluate Aggregate Exposure to Pesticides 12/09/2003
Tulve, N S., R. Fortmann, L S. Sheldon, AND E A. CohenHubal. Data Collected in the EPA's National Exposure Research Laboratory's Field Measurement Studies to Evaluate Aggregate Exposure to Pesticides. Presented at Society of Risk Analysis Meeting, Baltimore, MD, December 7-10, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Pesticide Results from An Interagency Effort to Characterize Contaminants in Child Care Centers 12/09/2003
Tulve, N S., R C. Fortmann, J. Zhou, W. Friedman, A. Fraser, D. Marker, S. M. Viet, C. Cave, G. M. Kyle, AND S. Kyle. Pesticide Results from An Interagency Effort to Characterize Contaminants in Child Care Centers. Presented at Society of Risk Analysis Annual Meeting, Baltimore, MD, December 7-10, 2003.
Abstract: Approximately 13 million children are placed in non-parental child care during the work day; but, children's exposures to chemicals in child care centers have not been characterized. To address this data gap, three federal agencies teamed to characterize contaminants in child care centers. The US Department of Housing and Urban Development, in collaboration with the Consumer Product Safety Commission and the Environmental Protection Agency (EPA), characterized young children's potential exposures to lead, allergens, and pesticides in randomly-selected licensed institutional child care centers. Multi-stage sampling with clustering was used to select approximately 150 child care centers in 30 primary sampling units in the United States. Child care centers were recruited into the study by telephone interviewers. Samples for lead, allergens, and pesticides were collected at multiple locations in each child care center by field technicians. Environmental data and information collected included the following: (1) Pesticide measurements on floors, other surfaces in the center, and soil collected near a play area, (2) Lead measurements on surfaces, soil, and paint, (3) Allergen measurements in dust, and (4) Information on center characteristics, pesticide use practices and application information, and demographics. By participating in this study, EPA will obtain valuable information on pesticide usage in child care centers, concentrations of pesticides on surfaces in the centers that children may contact, and the distribution of pesticides within child care centers. Results from this study will provide improved approaches for estimating children's exposures and data that can directly support the requirements of the Food Quality Protection Act of 1996.
This work has been funded in part by the US EPA under MOBIS contract no. 23F-8144H to Westat, Inc. It has been subjected to Agency review and approved for publication.

PRESENTATION Data Collected in the EPA's National Exposure Research Laboratory's Field Measurement Studies to Evaluate Aggregate Exposure 12/09/2003
Tulve, N S., R C. Fortmann, E A. CohenHubal, AND L S. Sheldon. Data Collected in the EPA's National Exposure Research Laboratory's Field Measurement Studies to Evaluate Aggregate Exposure. Presented at Society of Risk Analysis Annual Meeting, Baltimore, MD, December 7-10, 2003.
Abstract: The Food Quality Protection Act of 1996 requires children's risk assessments to be conducted using high quality and high quantity data. Currently, data on children's exposures and exposure factors are limited and insufficient to address risk assessments that do not rely heavily on default assumptions. Researchers in the U.S. Environmental Protection Agency's National Exposure Research Laboratory (NERL) have been conducting human exposure measurement studies to collect environmental, biological, and activity pattern data that can be used in the risk assessment process to evaluate young children's potential exposures to pesticides in order to reduce the reliance on standard default assumptions. Inhalation, dermal, and ingestion algorithms for indoor and outdoor locations where young children may spend their time are evaluated using the field measurement and exposure factor data collected. In addition, pesticide inventories, time-activity diaries, household habits, and occupant characteristics are collected to aid in the exposure assessment. Our systematic approach to collecting measurement and exposure factor data has helped us to recognize where the biggest data gaps and uncertainties still exist. For example, indirect ingestion exposure factors are difficult to quantify in field studies. This presentation will focus on the various types of data collected in the NERL's field measurement studies to help better characterize the exposure factors needed by the U.S. EPA's Office of Pesticide Programs to understand and evaluate young children's potential exposures. We will also discuss ways to reduce the data gaps that still exist.
This work has been funded wholly or in part by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION Hesi Exposure Factors Database for Aggregate and Cumulative Risk Assessment 12/09/2003
Breckenridge, C., D. Sargent, J. Evans, K. R. Solomon, V Zartarian, D. Vogel, W. D. Shade, J. Driver, M. Pandian, A. J. Goetz, S. Pettit, G. J. Mihlan, D. Miller, AND J. Zabik. Hesi Exposure Factors Database for Aggregate and Cumulative Risk Assessment. Presented at Society for Risk Analysis Conference 2003, Baltimore, MD, December 7-10, 2003.
Abstract: In recent years, the risk analysis community has broadened its use of complex aggregate and cumulative residential exposure models (e.g., to meet the requirements of the 1996 Food Quality Protection Act). The value of these models is their ability to incorporate a range of input variables in the overall estimation of total exposure and risk to an individual person with demographic, geographic and temporal specificity. However, a risk assessor's ability to evaluate the validity of a model outcome is predicated on a clear understanding of the quality and variability associated with these input variables. As such, the ILSI Health and Environmental Sciences Institute's (HESI) Risk Assessment Methodologies Technical Committee (RAM Committee) identified the need for better characterization and electronic availability of public, non-chemical specific data sets for use in state-of-the-science aggregate residential exposure models. As a first step, the RAM Committee, in conjunction with infoscientific.com, Inc., has reviewed public data on micro- and macro-activity activity factors (e.g., mouthing behavior event frequencies, time spent on a residential lawn), and mass-transfer-related factors (e.g., surface-to-skin/clothing mass transfer, biological monitoring measurements following choreographed dermal exposure events, dermal transfer coefficients, and transfer removal efficiencies). These data were evaluated both qualitatively and quantitatively and organized in an electronic database with their associated meta information. Additional data, meta information, and guidance can be added to this database in the future. Further, this effort provides important opportunities for collaboration and synergy with the EPA's Exposure Factors Handbook (general and child-specific) and regulatory agency exposure assessment methods development (e.g., EPA, Office of Pesticide Programs, Standard Operating Procedures for Residential Exposure Assessment). This database will be made publicly available and will assist risk assessors responsible for deterministic and probabilistic aggregate/cumulative residential risk analyses. The HESI RAM Technical Committee is composed of scientists from academia, industry, and government.
This work has been funded in part by the United States Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION Modeling Human Exposures and Dose Using a 2-Dimensional Monte-Carlo Model (Sheds) 12/08/2003
Ozkaynak, A H., J Xue, V Zartarian, J M. Burke, AND S E. Graham. Modeling Human Exposures and Dose Using a 2-Dimensional Monte-Carlo Model (Sheds). Presented at Society for Risk Analysis, Baltimore, MD, December 7-10, 2003.
Abstract: Since 1998, US EPA's National Exposure Research Laboratory (NERL) has been developing the Stochastic Human Exposure and Dose Simulation (SHEDS) model for various classes of pollutants. SHEDS is a physically-based probabilistic model intended for improving estimates of human exposure and dose to multimedia, multipathway pollutants and incorporates a two-dimensional Monte-Carlo simulation methodology implemented using SAS software. The two dimensional Monte-Carlo feature of the model is used to characterize population distributions of exposure and dose by explicitly quantifying the variability and the uncertainty in model inputs, parameters, and outputs. In particular, SHEDS-Pesticides combines human activity data (from national time/activity diary surveys and videography studies) with pesticide residue and concentration measurements in media contacted, exposure factors, and pharmacokinetic rate constants. Incurred exposure and dose are predicted for user-specified cohorts via eating contaminated foods or drinking water, inhaling contaminated air, touching contaminated surface residues, and ingesting residues from hand- or object-to-mouth activities. SHEDS-PM (i.e., particulate matter and its associated constituents) and SHEDS-ATOX (i.e., air toxics) use the same modeling approach as the SHEDS-Pesticides model, however the primary focus is on inhalation exposure and dose. The SHEDS model is designed to investigate the intensity, duration, frequency, route, and timing of exposures; to identify critical exposure factors and how to effectively reduce exposures; and to verify estimates with available biomarkers.
This work has been wholly funded by the United States Environmental Protection. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Available Micro-Activity Data and Their Applicability to Aggregate Exposure Modeling 12/08/2003
Zartarian, V, J Xue, A H. Ozkaynak, J. Driver, M. Pandian, AND T. Johnson. Available Micro-Activity Data and Their Applicability to Aggregate Exposure Modeling. Presented at Society for Risk Analysis Conference, Baltimore, MD, December 7-10, 2003.
Abstract: Several human exposure models have been developed in recent years to address children's aggregate and cumulative exposures to pesticides under the Food Quality Protection Act of 1996. These models estimate children's exposures via all significant routes and pathways including ingestion of chemicals from hand-to-mouth and object-to-mouth contact. Equations used to estimate hand-to-mouth and object-to-mouth ingestion exposures use micro-activity data variables such as frequency of hand-to-mouth contact, object-to-mouth contact, and surface areas of hands and objects mouthed. To help compile data for these model input variables, the ILSI Health and Environmental Sciences Institute's (HESI) Risk Assessment Methodologies Technical Committee (RAM Committee), in conjunction with infoscientific.com, Inc., has reviewed public data on frequency of hand-to-mouth behavior events frequencies. These data were evaluated and organized in an electronic database, and will be made publicly available. EPA's Office of Research and Development, National Exposure Research Laboratory, has analyzed these hand-to-mouth frequency data as well as data on fraction of hands mouthed by children, and has estimated probability distributions for variability and uncertainty that could be used in aggregate exposure models. These efforts also provide important opportunities for collaboration and synergy with development of the EPA's Child-Specific Exposure Factors Handbook and regulatory agency exposure assessment methods (e.g., EPA, Office of Pesticide Programs, Standard Operating Procedures for Residential Exposure Assessment).
This work has been funded in part by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication

PRESENTATION Use of Physiologically Based Pharmacokinetic Models in Assessments 11/24/2003
Blancato, J. Use of Physiologically Based Pharmacokinetic Models in Assessments. Presented at HEASD Seminar Series, Durham, NC, November 24, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Pesticide Exposure in the Residential Environment: Concepts, Field Collection Methodologies and Chemical Analysis 11/24/2003
Stout II, D M. Pesticide Exposure in the Residential Environment: Concepts, Field Collection Methodologies and Chemical Analysis. Presented at Seminar - North Carolina Central University, Durham, NC, November 24, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Measurement of PM2.5 Semi-Volatile Material With the Fdms Teom Monitor 11/23/2003
Grover, B., M. Kleinman, N. L. Eatough, D J. Eatough, P. K. Hopke, P. Venkatachari, W E. Wilson, W A. McClenny, R. W. Long, J. Ambs, M. Meyer, R. Cary, H. Grimm, AND B. Roe. Measurement of PM2.5 Semi-Volatile Material With the Fdms Teom Monitor. Presented at American Association for Aerosol, Anaheim, CA, October 20-24, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Evaluation of Disposable Diapers for Measurements of Pesticide Metabolites and Creatinine in Urine Samples 11/21/2003
Fortmann, R. Evaluation of Disposable Diapers for Measurements of Pesticide Metabolites and Creatinine in Urine Samples. Presented at National Children's Pilot Study Review, Research Triangle Park, NC, November 21, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION The Tampa Asthmatic Children's Study (Tacs) 11/21/2003
Stevens, C, R W. Williams, F L. Chen, R L. Seila, A F. Vette, W E. Amos, L S. Sheldon, K W. Leovic, C. E. Rodes, AND J. Thornburg. The Tampa Asthmatic Children's Study (Tacs). Presented at NCS Pilot Study Review, Research Triangle Park, NC, November 21, 2003.
Abstract: Conduct field monitoring studies with asthmatic children to identify and quantify factors that effect personal exposures in real-world environments and use the results of these studies to develop simple questions and/or measurements for classifying exposure in large studies as the National Children's Study.
This work has been funded wholly by the United States Environmental Protection Agency' s Office of Research and Development under contract # 68-D-99-012 to the Research Triangle Institute International. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

PRESENTATION Environmental Protection Agency Intern Program 11/20/2003
Franklin, B. Environmental Protection Agency Intern Program. Presented at NERL-HEASD Seminar, Research Triangle Park, NC, November 20, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Nccu Project and the EPA Intern Program 11/20/2003
Leovic, K W., D A. Vallero, AND B. Franklin. Nccu Project and the EPA Intern Program. Presented at HEASD Work-In-Progress Seminar, Research Triangle Park, NC, November 20, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Chlordanes in the Indoor and Outdoor Air of U.S. Three Cities 11/12/2003
Offenberg, J, Y. Y. Naumova, B. Turpin, S. Eisenreich, M. T. Morandi, T. Stock, S. Colome, A. M. Winer, AND C. P. Weisel. Chlordanes in the Indoor and Outdoor Air of U.S. Three Cities. Presented at Society for Environmental Toxicology & Chemistry, Austin, TX, Novermber 12, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Measuring Airborne PAHs from the New York World Trade Center Disaster 11/12/2003
Pleil, J D. Measuring Airborne PAHs from the New York World Trade Center Disaster. Presented at School of Public Health, Chapel Hill, NC, November 12, 2003.
Abstract: Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in ambient air, are suspected human carcinogens, and have been linked to genotoxic and mutagenic effects. Although there are no specific monitoring programs for PAHs in ambient air in the United States, there is a national network of about 1,100 samplers for assaying ambient particulate matter less than 2.5 ?m aerodynamic diameter (PM2.5). This work utilizes archived filter samples from the PM2.5 program for retrospective assay of particle-bound PAH concentrations in ambient air without the forethought of having deployed specialty PAH samplers.
Specifically, Teflon filter PM2.5 samples were collected by U.S. EPA in the aftermath of the New York World Trade Center (WTC) disaster for nondestructive assessment of the fine particle concentrations; these were subsequently archived. The samples had been collected daily at three WTC fenceline sites at "ground zero" and one site 5 blocks away from September 23, 2001 to March 30, 2002. We have assayed a subset (235) of these samples for certain particle-bound PAHs and have estimated their ambient concentrations spatially and as a function of time since September 11, 2001. The data exhibit large within-day and between-day concentration variability with a statistically significant trend decreasing to background over a period of about 6 months. We estimated an initial 8-fold PAH increase at ground zero during the first week (mean value 0.9 ng/m3 for 5- and 6-ring PAHs) after the disaster with a half-life of 64 days; the single site further away from ground zero shows a lower, less significant trend.

Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy.

PRESENTATION Chiral Analysis of Two Indoor Contaminants 11/12/2003
Ulrich, E M., K. T. Cummings, A W. Garrison, AND M K. Morgan. Chiral Analysis of Two Indoor Contaminants. Presented at Society for Environmental Toxicology & Chemistry, Austin, TX, November 12, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Effect of Soil Modifying Factors on the Bioavailability and Toxicity of Metal Contaminated Soils 11/10/2003
Bradham, K, N. T. Basta, R. P. Lanno, E. A. Dayton, M. Payton, AND J. Schroder. Effect of Soil Modifying Factors on the Bioavailability and Toxicity of Metal Contaminated Soils. Presented at Society of Environmental Toxicology and Chemistry, Austin, TX, November 9-13, 2003.
Abstract: Heavy metal and organic chemical contamination of soils is a worldwide problem posing a risk to humans and more directly, soil organisms. Metal toxicity is often not directly related to the total concentration of metals present due to a number of modifying factors that depend, in part, on soil chemical properties. Soil organic matter, pH, and clay content are soil chemical properties that influence metal toxicity and bioavailability. The primary objective of this research was to examine the simple and combined effects of soil physical/chemical parameters (e.g. pH, OM, clay) on metal bioavailability. A 28-d toxicity test using Eisenia andrei was conducted to assess the bioavailability of Pb, Cd, Zn, and As spiked individually in field soils. Earthworm bioassay endpoints included mortality, internal concentration of metal, and cocoon production. The 21 soils tested had a wide range of chemical properties including soil pH (4.18-8.47), cation exchange capacity (3.0-32.4 cmolc kg-1), organic matter (0.3-3.0%), and clay content (3.8-58.8%). The relationship between all biological endpoints (internal concentrations, mortality, and cocoon production), soil properties (pH, OC, % clay), and soil extractions (Ca(NO3)2-extractable, total, pore water) were determined using simple linear or curvilinear regression. The combined relation between each biological endpoint and soil properties (pH, OC, % clay) were further examined using multiple regression and path analysis. Internal Pb concentrations ranged from 28.7 to 782 mg Pb kg-1, with a mean of 271 mg Pb kg-1. A 27-fold difference in concentration in earthworms exposed to the same total soil content of Pb in 21 soils indicates that soil properties modified the uptake of Pb. There was a strong significant (r = 0.83, P < 0.01) relationship between reproduction and OC but, a less significant correlation (r = 0.52, P < 0.05) between reproduction and pH. Strong correlations between earthworm mortality and Pb extracted by Ca(NO3)2 (r = 0.85, P < 0.01) and pore water (r = 0.81, P < 0.01) were found.
This work has been funded wholly by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION Pollutants in the Home Environment: A Brief History and Overview 11/10/2003
Lewis, R. G. Pollutants in the Home Environment: A Brief History and Overview. Presented at Society of Environmental Toxicology and Chemistry, Austin, TX, November 9-13, 2003.
Abstract: The major portion of our exposure to environmental pollutants occurs within the home. Although various studies dating back as far back as the mid-1960s suggested this, it was not fully appreciated until the late 1980s or early 1990s. Many studies have assessed indoor-outdoor relationships of inorganic gases, volatile organic chemicals, pesticides, and other pollutants, with the major emphasis on air pollution. More recently, the focus has been on exposure to pollutants associated with house dust and contact with residues found on interior surfaces. Some of these studies have shown that nondietary and dermal contact exposures to dust and surface residues may contribute substantially to the aggregate exposures of small children in particular. Mycotoxins, molds on interior surfaces and insect and pet allergens in carpets and bedding have received the most recent attention. Such studies over the past two decades have resulted in many changes in building materials and furnishing, the designs of heating devices, and federal or state regulation of pesticides and other chemicals for residential use. They have also spawned the development of international standards for indoor air quality. This paper reviews the history of residential indoor environmental exposure assessment and its impact on our daily lives.
This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Coarse PM Methods Evaluation Study Study Design and Preliminary Results 10/29/2003
Ellestad, T G., R Vanderpool, P A. Solomon, M K. Harmon, S. Natarajan, C. A. Noble, R. Murdoch, J. Ambs, J. Tisch, AND G. Sem. Coarse PM Methods Evaluation Study Study Design and Preliminary Results. Presented at EPA State, Local & Tribal Air Contacts Meeting, Chicago, IL, October 28-30, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Biomarker Methods Development for Human Exposure Assessment Research 10/27/2003
Lindstrom, A B. AND M J. Strynar. Biomarker Methods Development for Human Exposure Assessment Research. Presented at Health and Environmental Sciences Institute, Washington, DC, October 27, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Prediction of Fine Particulate Levels at Unmonitored Locations 10/23/2003
Smith, L., S Mukerjee, G A. Norris, M Gonzales, C Stallings, L Neas, AND A H. Ozkaynak. Prediction of Fine Particulate Levels at Unmonitored Locations. Presented at American Association for Aerosol Research, Anaheim, CA, October 20-24, 2003.
Abstract: In November and December of 1999, air concentrations of ultrafine, fine, and coarse particulate matter were measured at two intensive sites in El Paso, Texas. The intensive sites included collocated measurements of NO2 and volatile organic compounds (VOCs) in the air from both continuous and passive samplers. Passive sampling of NO2 and VOCs was also conducted at twenty-two school locations. One of the goals of this study was to attempt to predict the fine and ultrafine particulate concentrations at a total of fifty-five schools, none of which monitored particulates.
To accomplish this, the passive samplers were first compared to the continuous monitors at the two intensive sites. Based on these results, predictive equations for particulate levels were developed as functions of the passive monitor measurements. These predictive equations were then applied at the twenty-two schools with passive monitors. These predicted particulate levels were then utilized to develop predictive equations at the twenty-two schools in terms of certain ancillary variables whose values could be obtained at all school locations.

Finally, predictions were obtained at all school locations by applying these last equations. The ancillary variables were obtained from information supplied by the El Paso school district, the city, the U. S. Census, and from application of GIS techniques to these data. The ancillary variables used were: section of the city, distance to the nearest border crossing, elevation, population density, distance to roads with certain levels of traffic, traffic intensity around the schools, and distance to the nearest petroleum facility. It is envisioned that the results are to be used in a qualitative basis in an epidemiological study of El Paso school children.

The information in this document has been funded wholly or in part by the U.S. Environmental Protection Agency under Contracts Contract 68-D0-0206 to ManTech Environmental Technology, Inc. and 68-D-99-012 to Research Triangle Institute. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

PRESENTATION The Relationship Between Real-Time and Time-Integrated Coarse (2.5-10mn), Intermediate (1-2.5MM), and Fine ( 10/23/2003
Geller, M. D., P. M. Fine, C. Sioutas, AND P A. Solomon. The Relationship Between Real-Time and Time-Integrated Coarse (2.5-10mn), Intermediate (1-2.5MM), and Fine (
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION A New Non-Ambiguous Analytical Technique for the Identification of Areosol Oxygenated Compounds 10/23/2003
Edney, E O., T E. Kleindienst, M Lewandowski, M. Jaoui, AND E. W. Corse. A New Non-Ambiguous Analytical Technique for the Identification of Areosol Oxygenated Compounds. Presented at American Association for Aerosol Research, Anaheim, CA, October 20-24, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Determining Coarse Particulate Matter Concentrations: A Performance Evaluation of Candidate Methodologies Under Wintertime Conditions 10/23/2003
Solomon, P A., T G. Ellestad, T L. Conner, R B. Zweidinger, M. Harmon, T. Hanley, L. Byrd, R. Scheffe, R. W. Vanderpool, R. Murdoch, S. Natarajan, C. A. Noble, J. Ambs, G. Sem, AND J. Tisch. Determining Coarse Particulate Matter Concentrations: A Performance Evaluation of Candidate Methodologies Under Wintertime Conditions. Presented at American Association for Aerosol Research, Anaheim, CA, October 20-24, 2003.
Abstract: The main objective of this study is to evaluate the performance of sampling methods for potential use as a Federal Reference Method (FRM) capable of providing an estimate of coarse particle (PMc: particulate matter with an aerodynamic diameter between 2.5 um and 10 um) mass concentrations in ambient air. Five sampling approaches are being evaluated. These approaches include a time-integrated or discrete method for measuring coarse particles directly using a sequential dichotomous sampler; a discrete difference method, which uses two FRM samplers, one to measure PM2.5 and the other PM10 with the difference, PM10-PM2.5, representing an estimate of PMc. Filters from these two sampler types are analyzed gravimetrically in the laboratory subsequent to collection. Two continuous coarse particle samplers that measure PMc directly with a time resolution of 1 hour or less and provide data in near real-time also are being evaluated. One sampler is a commercially available system based on beta attenuation, while the other is based on TEOM technology. The sequential and continuous methods use the dichotomous virtual impactor for separating fine and coarse particles. An aerodynamic particle sizer (APS) also is being evaluated that measures the aerosol size distribution in near-real time. The APS estimates ambient PMc mass concentration based on an assumed density of the measured PMc.
The samplers are being evaluated in three locations that provide diverse challenges to the samplers, including high PMc to PM10 ratios, high PM2.5 to PM10 ratios, and high and low PMc values under cold conditions. Results presented here are from a 30-day intensive monitoring effort in Gary, IN during March and April 2003. The site and timing of the study was chosen to test the samplers under cold conditions with highly variable PMc concentrations. The site was located near a steel mill that intermittently impacted the sampling site with high PMc concentrations. Meteorological conditions encountered during the study were quite variable and included periods of rain, snow, high wind speeds, and ambient temperatures ranging from -15 C to + 22 C. As measured by the FRM difference method, daily PMc concentrations ranged from 5 ug/m3 to 58 ug/m3 with a measured mean of 20 ug/m3. The minimum, mean, and maximum PM2.5 to PM10 ratios, which are an indicator of the ambient PM size distribution, ranged from 0.33 to 0.80 with a mean of 0.55.

This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION The Relationship Between Real-Time and Time-Integrated Coarse (2.5-10mm), Intermediate (1-2.5MM), and Fine (<2.5MM) Particulate Matter in the Los Angeles Basin 10/23/2003
Geller, M. D., P. M. Fine, C. Sioutas, AND P A. Solomon. The Relationship Between Real-Time and Time-Integrated Coarse (2.5-10mm), Intermediate (1-2.5MM), and Fine (<2.5MM) Particulate Matter in the Los Angeles Basin. Presented at American Association for Aerosol Research, Anaheim, CA, October 20-24, 2003.
Abstract: Population exposure to ambient particulate matter (PM) has received considerable attention due to the association between ambient particulate concentrations and mortality. Current toxicological and epidemiological studies and controlled human and animal exposures suggest that all size fractions of PM may be responsible for observed health effects. Recently, the governments of European countries and the U.S. have been discussing a new PM1 standard. The purpose of this standard is to preclude invasion of coarse particles into the fine PM mode. This notion is predicated on evidence that suggests that PM1-2.5 is dominated by coarse PM.
In this study, coarse (PM10-PM2.5), intermodal (PM1-2.5), and fine (PM2.5) PM mass concentrations in four different sites are measured with both continuous and time-integrated sampling devices. Two source sites, USC and Downey, CA and two receptor sties, Claremont and Riverside, CA, were monitored for at least three months each. The main objective is to document both short-term and diurnal variations in ambient fine, intermodal, and coarse particulate mass concentrations with respect to each other while considering the effects of sources, weather, wind speed, and wind direction. Of particular interest are the relationships between PM1 and PM1-2.5 and coarse PM with PM1-2.5. Results show strong correlations between PM1 and intermodal PM in receptor sites. These two modes in source sites show moderate correlation (R2~0.5). The contribution of PM1-2.5 to PM2.5 shows seasonal variation with the largest contribution in the summer months, most likely due to enhanced long range transport. Coarse PM is poorly correlated with intermodal PM in USC and Riverside. The correlation is dependent upon the mass concentration at Claremont, with smaller mass concentrations being moderately-to-well-correlated. This correlation becomes moderate in Downey, most likely because the local freeway is a source of all particle sizes. Continuous data yield insight into the possibility that PM1 is growing into PM1-2.5 via a complex process that involves stagnation of the ambient aerosol during high relative humidity conditions, followed by advection during daytime hours.

This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Determining Coarse Particulate Matter Concentrations in Gary, in: A Performance Evaluation of Candidate Methodologies Under Wintertime Conditions 10/23/2003
Determining Coarse Particulate Matter Concentrations in Gary, in: A Performance Evaluation of Candidate Methodologies Under Wintertime Conditions. Presented at American Association for Aerosol Research, Anaheim, CA, October 20-24, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Composition of PM2.5 in Research Triangle Park, North Carolina, USA During the Winter of 2003 10/22/2003
Edney, E O., T E. Kleindienst, M Lewandowski, AND M. Jaoui. Composition of PM2.5 in Research Triangle Park, North Carolina, USA During the Winter of 2003. Presented at American Association for Aerosol Research National Meeting, Anaheim, CA, October 20-24, 2003.
Abstract: Ambient PM2.5 contains a variety of inorganic compounds, nearly all of which can be measured, and a complex mixture of organic compounds, of which less than 20% of the constituents have been identified. While many of these compounds are directly emitted into the troposphere, a significant component of PM2.5 comes from gas-to-particle conversion of photooxidation products of biogenic and anthropogenic compounds. Determining the relative contributions of primary emissions versus secondary production is critically needed to develop cost-effective control strategies for reducing ambient PM2.5 concentrations. As a step in addressing this issue we carried out a short-term field study in Research Triangle Park, NC during the summer of 2000 to identify inorganic and organic compounds in PM2.5. The purpose of the present study was to gather similar information for PM2.5 samples collected during the winter. Specifically, a short term field study was undertaken in Research Triangle Park, NC, USA during the winter of 2003 (1) to determine the inorganic composition of PM2.5 and (2) to identify classes of polar oxygenates in PM2.5 containing carbonyl and/or hydroxyl functional groups and, to the extent possible, determine the individual particle-bound oxygenates that make up each class. The sampling site was in a semi-rural environment with expected impacts from both biogenic and anthropogenic sources. Six PM2.5 samples were collected and analyzed for gravimetric mass, inorganic composition by ion chromatography, carbon by a thermal-optical method, and polar oxygenated compounds by GC-MS after derivatization of the solvent extracts. Detailed analyses of the organic fraction were carried out using the O-(2,3,4,5,6-pentafluorobenzyl)hydroxy amine (PFBHA) method for the derivatization of carbonyl groups, N,O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA) method for hydroxyl groups, and the PFBHA/BSTFA double derivative method. The ambient PM2.5 mass concentrations for the winter field study ranged between 6 and 13 ug m-3, with average mass concentrations of 1.8 ug m-3 sulfate, 0.5 ug m-3 nitrate, and 2.9 ug m-3 total carbon. GC-MS analyses of the organic extracts were consistent with the presence of compounds containing polar carbonyl and hydroxyl functional groups. These data also revealed significant differences between the nature of the PM2.5 polar organic fractions collected during the summer of 2000 and the winter of 2003. While the winter and summer data were similar as shown by the detection of polar organic tracers for both secondary organic aerosol from biogenics and primary wood smoke emissions, the levoglucosan levels suggested wood smoke emissions were the more important of the two processes during the winter sampling period.
This work has been funded fully, or in part, by the United States Environmental Protection Agency, under Contract Number 68-D00-206 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication.

PRESENTATION Soa Formation from the Irradiation of a-Pinene-NOx in the Absence and Presence of Sulfur Dioxide 10/22/2003
Kleindienst, T E., M Lewandowski, E O. Edney, M. Jaoui, AND E. W. Corse. Soa Formation from the Irradiation of a-Pinene-NOx in the Absence and Presence of Sulfur Dioxide. Presented at American Association for Aerosol Research National Meeting, Anaheim, CA, October 20-24, 2003.
Abstract: Sulfur dioxide (SO2) is an important constituent in the polluted atmosphere. It is emitted from combustion sources using fuels that contain sulfur. Emissions of SO2 in the United States were reportedly 17 Tg in 1996 with most coming from coal and petroleum combustion. The primary removal mechanism of SO2 in the atmosphere is through reaction with the hydroxyl radical to produce sulfuric acid which will typically condense onto preexisting aerosol to form an acidic aerosol. Recent reports have suggested that prior to neutralization, these aerosols could lead to enhanced secondary organic aerosol (SOA) formation through in-situ heterogeneous reactions.
In the present study, this hypothesis was tested by producing SOA through irradiating mixtures of a-pinene/NOx in a smog chamber. The chamber was operating in a dynamic mode to allow an adequate collection of aerosol mass at reasonably moderate concentrations. Chamber conditions of 2 ppmC a-pinene, 0.25 ppm NOx, and a chamber residence time of 6 hours were set to ensure that extensive secondary gas-phase chemistry occurred. Under these conditions, nucleation of the oxidized mixture occurred producing particles for measurement. SOA yields were determined from mass measurement of the collected SOA onto Zefluor filters. These measurements used carbon-based and extractable XAD denuders to minimize filter artifacts. Organic carbon mass of the aerosol was determined using quartz filters which were corrected for the positive artifact by using a backup quartz filter. Organic aerosol collected on Zefluor filters were extracted for analysis of individual compounds using GC-MS.

Conditions in the chamber were maintained to allow the conversion of a-pinene (0.949) to remain identical for both parts of the experiment. From the Zefluor filter collections in the absence of SO2, the SOA yield was found to be 15.9%. Under the photochemical conditions in the chamber, the conversion of SO2 due to reaction with hydroxyl radicals was 4.4%, which resulted in a sulfate concentration of 45 ug m-3 associated with the predominately organic aerosol. In the presence of SO2, the SOA yield increased to 26.1%. Similarly, the yield of organic carbon was found to increase by 32% in the presence of SO2. GC-MS analysis of the aerosol showed differences in the composition of the organic aerosol under the two conditions.

This work has been funded fully, or in part, by the United States Environmental Protection Agency, under Contract Number 68-D5-0049 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication.

PRESENTATION USEPA Sheds Model: Methodology for Exposure Assessment for Wood Preservatives 10/22/2003
Ozkaynak, A H., V Zartarian, J Xue, AND W. Dang. USEPA Sheds Model: Methodology for Exposure Assessment for Wood Preservatives. Presented at Annual Conference on Soils, Sediments and Water, Amherst, MA, October 20-23, 2003.
Abstract: A physically-based, Monte Carlo probabilistic model (SHEDS-Wood: Stochastic Human Exposure and Dose Simulation model for wood preservatives) has been applied to assess the exposure and dose of children to arsenic (As) and chromium (Cr) from contact with chromated copper arsenate (CCA)-treated playsets and residential decks. Short-term (for As and Cr), intermediate-term (for As and Cr), and lifetime (for As only) absorbed doses are estimated for: dermal contact with playset or deck residues; dermal contact with soil concentrations around treated playsets or decks; ingestion of CCA-containing soil near treated playsets or decks; and ingestion of wood residues via the hand-to-mouth pathway.
SHEDS-Wood calculates the predicted exposure and dose to As and Cr using age and gender representative time-location-activity diaries from EPA's Consolidated Human Activity Database (CHAD). Based on user-specified inputs, exposure days and exposure events within a day are simulated. The time series of exposure and dose are computed using pathway-specific exposure equations and the real-time diary activities for which a contact event is possible. Model inputs, represented as analytical distributions (e.g., lognormal, beta) include: fraction of outdoor time and days per year a child plays on/around playsets and decks; As and Cr residue and soil concentrations on or near CCA treated playsets or decks; and various exposure factors such as residue-to-skin transfer efficiencies, soil-to-skin adherence factor, saliva and bathing removal efficiency, daily incidental soil ingestion rate, fraction of hand skin surface area contacting soil, frequency of hand to mouth activity, maximum dermal loading, and dermal and GI absorption rates. Model results for the simulated population are analyzed to determine the dominant pathways influencing predicted exposures and dose. Both deterministic and statistical methods are used to assess the sensitivity of results to key input variables. Uncertainty analyses are performed using the 2nd Stage Monte-Carlo simulation results and a nonparametric bootstrap methodology.

This work has been funded wholly by the United States Environmental Protection Agency.
It has been subjected to Agency review and approved for publication.

PRESENTATION A New Non-Ambiguous Analytical Technique for the Identification of Aerosol Oxygenated Compounds 10/22/2003
Jaoui, M., E. H. Daughtrey Jr., E. W. Corse, T E. Kleindienst, M Lewandowski, AND E O. Edney. A New Non-Ambiguous Analytical Technique for the Identification of Aerosol Oxygenated Compounds. Presented at American Association for Aerosol Research National Meeting, Anaheim, CA, October 20-24, 2003.
Abstract: The most important organic products identified in the particle phase from field samples and from smog chamber experiments are polar oxygenated compounds containing one, two, three or more oxygenated functional groups (e.g. hydroxyl, carboxylic acid, ketone). Current procedures used for analyzing oxygenated compounds are based on derivatizing carbonyls group using O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) or methoxyamine along with a silylation agent (e.g. bis-(trimethylsilyl)trifluoroacetamide (BSTFA)) to trimethylsilylate carboxylic and hydroxyl groups simultaneously. When one or more hydroxyl group coexist in the same molecule with a carboxylic group, this popular method suffers from lack of resolution between these two different groups.
In this study, a new analytical technique was developed toward the identification of multi-functional compounds bearing at least one hydroxyl and one carboxylic group. This technique is based on derivatizing the carboxylic group(s) first of the multi-functional compound using an alcohol (e.g. methanol, n-butanol) in the presence of a relatively strong Lewis acid (BF3) as catalyst. This esterification reaction quickly and quantitatively converts carboxylic acids to their ester forms. The second step is based on silylation of the ester compounds using BSTFA as derivatizing agent. For compounds bearing in addition to carboxylic and hydroxyl groups, ketone groups, a third step was used based on PFBHA derivatization of the carbonyls. Different parameters including temperature, time of reaction and artifacts were optimized. A GC-MS in EI or in methane CI mode was used for the analysis of these compounds.

The technique was tested on a number of multi-functional compounds bearing at least one hydroxyl and one carboxylic group. The interpretation of their methane CI mass spectra shows two different clear fragmentation patterns. For example, when derivatized only with BF3/methanol their mass spectra comprises three primary ions at m/z M+1, M+29, and M-31 for compounds bearing only hydroxyl groups and M+1, M+29, M-31, and M-17 for those bearing hydroxyl and carboxylic groups. However, when a second derivatization (BSTFA) was used, compounds bearing hydroxyl and carboxylic groups show in addition to the ions observed before, ions at m/z 73, M-15, M+73, M-59, and M-75. To the best of our knowledge, this technique describes for the first time the power to identify multi-functional oxygenated compounds bearing simultaneously one or more hydroxyl and carboxylic groups. The knowledge gained regarding this technique was used to positively identify reaction products in an extract of three complex mixtures that was difficult if not impossible before the development of this technique. The first two mixtures were obtained from a smog chamber photo-oxidation of a-pinene and toluene in the presence of NOx respectively, and the third one was obtained from particle field sample.

This work has been funded fully, or in part, by the United States Environmental Protection Agency, under Contract Number 68-D-00-206 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication.

PRESENTATION Summary of Biological and Environmental Monitoring Results from the Agricultural Health Study/Pesticide Exposure Study 10/21/2003
Jones, M., K W. Thomas, S. M. Gordon, S. Reynolds, M. G. Nishioka, J. Raymer, R. Helburn, C. Lynch, C. Knott, D. Sandler, AND M. Alavanja. Summary of Biological and Environmental Monitoring Results from the Agricultural Health Study/Pesticide Exposure Study. Presented at 5th International Symposium of Rural Peoples, Saskatchewan, Canada, October 10-23, 2003.
Abstract: The Agricultural Health Study (AHS) is a prospective epidemiologic study of pesticide applicators and spouses in Iowa and North Carolina. Exposure to 2,4-D or chlorpyrifos was measured for a subset of applicators and their families in the AHS Pesticide Exposure Study to assess exposure classification procedures. Applicators were selected based on their plans to apply 2,4-D or chlorpyrifos, their application methods and their use of personal protective equipment. Potential exposures were measured on one day of pesticide handling, mixing, loading, and application (PHMLA) using dermal patch, hand wipe, and personal air samples. Dermal patch samples were collected by placing cellulose or gauze patches on the body. The surface area of each patch is sized proportionately to the body area it represents. Hand wipe samples were collected using a sub-sampling technique that wipes approximately 10% of the surface area of each hand. Urinary biomarker levels were measured in pre-and post-application samples from each applicator and for participating spouses and children. Questionnaires associated with the PHMLA activities were collected to provide information about work practices, protective equipment use, and hygiene. Field monitoring was performed from 2000 to 2002 in Iowa and North Carolina, with 108 applicator, 47 spouse, and 12 child measurements completed.
The use of the target chemical during the observed PHMLA, and on days before and after, affected pre- and post-application urinary levels for some 2,4-D and chlorpyrifos applicators. Pre-application urinary 2,4-D concentrations ranged from <1 to 410 ug/g creatinine and post-application levels ranged from <1 to 1100 ug/g creatinine. Urinary concentrations ranged from <1 to 65 ug/g creatinine for spouses and children of 2,4-D applicators. Applicator urinary concentrations of 3,5,6-trichloropyridinol, a chlorpyrifos metabolite, ranged from 1 to 29 ug/g before application and from 2 to 79 ug/g creatinine in post-application samples. Urinary concentrations ranged from 3 to 15 ug/g creatinine for spouses and children of chlorpyrifos applicators. The amount of a target chemical measured on applicator dermal patches ranged from <1 to 34,000 ug and from <1 to 3000 ug on hand wipe samples. An overview of the urinary biomarker, dermal, and inhalation measurement results will be presented, along with relationships between observed work practices and target chemical applied.

This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Particle Speciation and Emission Profiles of Small 2-Stroke Engines 10/21/2003
Volckens, J., J N. Braddock, R. Snow, C. Loomis, AND W. Crew. Particle Speciation and Emission Profiles of Small 2-Stroke Engines. Presented at American Association for Aerosol Research, Anaheim, CA, October 21, 2003.
Abstract: The Human Exposure and Atmospheric Sciences Division (HEASD) conducts studies designed to acquire information from emission sources for use in source apportionment studies. The objective of this work is to characterize a complete, speciated emission profile (PM and air toxics) from new and in-use two-stroke engines. Little is known about the organic and elemental composition of the exhaust from these engines, even though their emission rates are high. A variety of engines will be tested on a low-torque dynamometer in conjunction with a constant-volume dilution/sampling system. Fuel mixtures will consist of a blend of two fuels (a baseline gasoline and a reformulated fuel containing ethanol) and two oils (synthetic or petroleum). Particulate matter samples will be speciated for elemental and organic carbon content, individual polar and non-polar compounds (including semivolatile species), metals, and water soluble ions. Gas-phase samples will be speciated for both regulated (NAAQS) and non-regulated compounds. Results from this work will provide emission profiles for future source apportionment studies and regulated, mobile source emission models, and will demonstrate the effect of fuel composition on emissions.
This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Summary of Biological and Environmental Monitoring Results from the Agricultural Health Study Pesticide Exposure Study 10/20/2003
Jones, M., K W. Thomas, S. M. Gordon, S. Reynolds, M. G. Nishioka, J. Raymer, R. Helburn, C. Lynch, C. Knott, D. P. Sandler, M. Dosemeci, AND M. Alavanja. Summary of Biological and Environmental Monitoring Results from the Agricultural Health Study Pesticide Exposure Study. Presented at International Symposium of Rural Peoples, Saskatchewan, Canada, October 19-23, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION PM Ambient Methods Research, Ord Carbon Status Report 10/17/2003
Solomon, P A. PM Ambient Methods Research, Ord Carbon Status Report. Presented at State Air Monitoring Working Group, San Francisco, CA, October 16-18, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION EPA's PM Supersites Program, EPA's Communication Strategy 10/17/2003
Solomon, P A. EPA's PM Supersites Program, EPA's Communication Strategy. Presented at States Air Monitoring Working Group, San Francisco, CA, October 16-18, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Comparison of the Stn and Improve Networks for Mass and Selected Chemical Components 10/17/2003
Solomon, P A., T. KlamserWilliams, P P. Egeghy, D. Crumpler, AND J. Rice. Comparison of the Stn and Improve Networks for Mass and Selected Chemical Components. Presented at State Air Monitoring Working Group, San Francisco, CA, October 16-18, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Analysis of Motor Vehicle Emissions in a Houston Tunnel During the Texas Air Quality Study 2000 10/15/2003
McGaughey, G. R., N. R. Desai, D. Allen, R L. Seila, W A. Lonneman, M. P. Fraser, R. A. Harley, A. K. Pollack, J. M. Ivey, AND J. H. Price. Analysis of Motor Vehicle Emissions in a Houston Tunnel During the Texas Air Quality Study 2000. Presented at NARSTO Workshop on Innovative Methods for Emission-Inventory Development and Evaluation, Austin, TX, October 14-17, 2003.
Abstract: Measurements from a Houston tunnel were used to develop fuel consumption based emission factors for CO, NOx, and Non-Methane Organic Compound (NMOC) for on-road gasoline vehicles. The Houston NOx emission factor was at the low range of emission factors reported in previous (primarily pre-1996) tunnel studies while the NMOC emission factor was slightly higher than that reported in the previous tunnel studies. The fuel based tunnel emission factors for CO, NOx and NMOC were compared to emission estimates calculated by the MOBILE5b and MOBILE6 models by making estimates of fuel efficiencies. The MOBILE6 emissions estimate for CO from gasoline vehicles was over twice that provided by the tunnel measurements and predicted by MOBILE5b. NMOC and NOx emission factors based on the tunnel data were consistent with the MOBILE6 estimates.
This work has been funded in part by the United States Environmental Protection Agency under intergovernmental agreement RWTX939025-01-0 to the Texas Natural Resources Conservation Commission. It has been subjected to Agency review and approved for publication.

PRESENTATION Children's Aggregate Exposure to Polycyclic Aromatic Hydrocarbons (PAHs) 10/15/2003
Chuang, J. C., N. K. Wilson, S. M. Gordon, M K. Morgan, AND L S. Sheldon. Children's Aggregate Exposure to Polycyclic Aromatic Hydrocarbons (PAHs). Presented at Environmental & Occupational Seminar Series, Ottawa, Canada, October 15, 2003.
Abstract: Polycyclic aromatic hydrocarbons (PAHs) have been frequently detected at children's homes and day care centers and may pose health concerns due to their carcinogenicity. Most PAHs have been persistent indoors and outdoors, therefore, children may be exposed to chronic low levels of PAHs in these microenvironments. We have developed and evaluated sampling and analysis methods to measure the levels of several PAHs in soil, air, dust, food, and surface wipe samples. These methods have been used and refined in several pilot studies conducted at children's homes and day care centers. We recently used these methods in the Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study. The CTEPP study measured the aggregate exposures of about 260 preschool children to over 50 persistent organic pollutants, including 9 PAHs, in their everyday environments. We will discuss the sampling and analysis methods used for measuring PAHs in the multimedia samples and the published results from our pilot studies. In addition from the CTEPP study, we will report the preliminary results for the levels of PAHs measured in environmental media collected at the homes and day care centers of 130 North Carolina preschool children.
This work has been funded wholly or in part by the United States Environmental Protection Agency under Cooperative Agreement CR822073 and contract No. 68-D-99-011 to Battelle. It has been subjected to Agency review and approved for publication.

PRESENTATION Comparison of the Stn and Improve Networks for Select Potentially Toxic Trace Elements (Preliminary Results) 10/09/2003
Solomon, P A., T. KlamserWilliams, P P. Egeghy, D. Crumpler, AND J. Rice. Comparison of the Stn and Improve Networks for Select Potentially Toxic Trace Elements (Preliminary Results). Presented at North East States for Coordinated Air Use Management, Las Vegas, NV, October 8-9, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Methods Development for the Analysis of Chiral Pesticides 10/01/2003
Ulrich, E M. Methods Development for the Analysis of Chiral Pesticides. Presented at ORD/OPPTS Scientist to Scientist Seminar, Research Triangle Park, NC, October 1, 2003.
Abstract: Chiral compounds exist as a pair of nonsuperimposable mirror images called enantiomers. Enantiomers have identical physical-chemical properties, but their interactions with other chiral molecules, toxicity, biodegradation, and fate are often different. Many pharmaceutical compounds are comprised of enantiomers, furthermore 29% of 1700 surveyed agrochemicals and their degradates are chiral. With increased regulatory pressure, specific enantiomers are beginning to be treated as separate compounds. Single or enriched enantiomer formulations are becoming more prevalent, especially in Europe. The invention of chiral separation techniques significantly increased the development of methods for chiral compounds. The mechanism for enantiomer separation using derivatized cyclodextrin gas chromatography is not well understood, but is becoming a popular analytical tool. We will discuss the different types of columns, parameters affecting separation, and the peak fitting method for determining enantiomer fractions. Enantiomer fractions [EF = chromatographic peak area (+) enantiomer / sum of (+) and (-) areas] can be used to differentiate between types of degradation pathways, implicate sources of contamination, and give a more complete picture of environmental contamination for more accurate risk assessments. Currently at EPA, these techniques are being employed in human exposure projects like CTEPP, and ecological research projects in sediment, plants, and biota.
This work has been funded by the US EPA and USGS. It has been subjected to EPA review and approved for presentation. Mention of trade names of cmercial products does not constitute endorsement or recommendation for use.

PRESENTATION Performance Evaluation of Federal Reference Methods and Federal Equivalent Methods for Coarse Particulate Matter: Proposed Study Design 09/28/2003
Performance Evaluation of Federal Reference Methods and Federal Equivalent Methods for Coarse Particulate Matter: Proposed Study Design. Presented at State Air Monitoring Working Group, Stowe, VT, September 27-28, 2002.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Organic Characterization of Airborne Particles: Interlaboratory Comparison Studies and the Development of Standards and Reference Materials 09/24/2003
Lewtas, J, S. A. Wise, AND M. M. Schantz. Organic Characterization of Airborne Particles: Interlaboratory Comparison Studies and the Development of Standards and Reference Materials. Presented at International Symposium on Polycyclic Aromatic Compounds, Amsterdam, The Netherlands, September 21-25, 2003.
Abstract: Investigators characterizing and quantifying the organic compounds in particulate matter (PM) have completed the second interlaboratory comparison study. The first study used a subset of SRM1649a sieved to <63um(API) as an unknown sample, an extract of API, and SRM1649a for use as a control. For the second study, PM2.5 collected recently in Baltimore, MD (APII) was the unknown sample. The target analytes included polycyclic aromatic hydrocarbons(PAHs), nitrated-PAHs, alkanes (including hopanes and cholestanes), sterols, carbonyl compounds (ketones and aldehydes), acids (alkanoic and resin), phenols, and sugars. For the first and second study, 23 and 17 laboratories, respectively, reported. This is a performance-based study and laboratories used the methods they routinely use to analyze similar samples. The data received, following outlier testing, were then used to assign a consensus value to each analyte in the unknown samples. Results were used in the consensus value assignment only if the laboratory's results for SRM1649a were within 30% of the uncertainty limits of the certified values. Z-scores and p-scores have been determined for assessment of accuracy and precision. For these exercises, z-scores, which assess the difference between the result of the laboratory and the exercise assigned value, were calculated on the basis of 25% difference from the consensus value. For API, 65% of the data submitted were within 25% of the consensus values while for APII only 47% of the data submitted were within 25% of the consensus values. For the second study, the largest number of results reported for a chemical class was for 23 PAHs with 14 labs reporting. The next largest number of labs reporting other analyte classes was for alkanes (9), hopanes and cholestanes (6), carbonyl compounds (4), nitro-PAH (3), and phenols/sugars (2). The PAH concentrations for the APII sample of contemporary PM2.5 were similar to the concentrations found in SRM1649. The working group has reached consensus on a priority list for the development of calibration standards and internal standards.
This work has been funded by the US Environmental Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION Comparing Pesticide Transfers from Residential Surface Using Transferable Residue Sampling Techniques and Video-Fluorescent Imaging 09/24/2003
Nishioka, M. G., W. Ivancic, E A. CohenHubal, K. Andrews, M. Morara, AND J. Sowry. Comparing Pesticide Transfers from Residential Surface Using Transferable Residue Sampling Techniques and Video-Fluorescent Imaging. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: The recent change from organophosphate (OP) to pyrethroid insecticides for indoor residential pest control may significantly affect the relative importance of different exposure routes because of differences in physical/chemical properties of these two classes of compounds. In general, the pyrethroids are less volatile and far more lipid-soluble, thus suggesting that it may be increasingly important to characterize the dermal transfer route. We have compared the transfers to PUF Roller, C18 disks, and various wipe and scrub media for two fluorescent tracers, water-soluble riboflavin and lipophilic Uvitex OB, that were co-applied to carpet and laminate surfaces with 5 different OP and pyrethroid pesticides. Aqueous solutions of analytes were sprayed onto surfaces under controlled conditions; surfaces were fully dry before sampling; analyses were carried out by extraction and either GC/MS or spectrofluorimetry. We also applied only the tracers to surfaces and measured the transfers to skin after each of seven repeated hand contacts with the surface. Fluorescence on hands was measured at 600 nm for riboflavin and at 530 nm for Uvitex OB using a video camera and image intensifier with Matrox Image acquisition software. Surface application loadings of 0.2 ug/cm2 were used to approximate loadings that occur in homes after product use. In general terms, transfer rates were approximately 0.02-0.2% for C18, 0.2-2% for PUF Roller, and 2-50% for scrubs and wipes. Hand transfers were similar to wipe and scrub transfer rates, namely, 1-50% depending on analyte, loading and contact parameters.
This work has been funded by the United States Environmental Protection Agency under Contract No. 68-D-99-011 to Battelle. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation by the US EPA.

PRESENTATION Course PM Methods Evaluation Study 09/24/2003
Ellestad, T G., R. W. Vanderpool, P A. Solomon, M. Harmon, S. Natarajan, C. A. Noble, AND B. Murdoch. Course PM Methods Evaluation Study. Presented at Environmental Technology Verification Program, Washington, DC, September 24, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Determinants of Residential Lead Exposure 09/24/2003
Egeghy, P P., S. Catlin, P. B. Ryan, AND J J. Quackenboss. Determinants of Residential Lead Exposure. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: The phase-out of leaded gasoline, and the accompanying decrease in lead emissions, resulted in a dramatic decline in mean blood lead levels from the late 1970s through the early 1990s. Nonetheless, lead exposures remain a public health concern. Long-term exposures to even low-levels adversely affect the hematopoietic and central nervous systems, and environmental sources often include the home. The National Human Exposure Assessment Survey in Maryland (NHEXAS-MD), a longitudinal study of multimedia exposure to metals, pesticides, and polycyclic aromatic compounds, aimed to identify sources of exposure and activities associated with elevated exposures. Regression analyses of concentrations and questionnaires responses were performed for lead concentrations in indoor air, dust, and dermal wipes using mixed-effects models. Significant factors associated with increased indoor air lead concentrations included outdoor air concentrations, open window periods, age of housing, and painting activities. Pet ownership and air filter use were associated with decreased concentrations. Significant predictors of lead dust loadings included lead soil concentrations, open window periods, chipping interior paint, age of house, and fireplace use. Concrete entrance and frequency of indoor pesticide use were also significant, but were perhaps surrogates for other factors. Concentrations of lead measured in dermal wipes were associated with overall dust level in residence, bathing/washing activities, time spent outside at home, skin contact with dirt or soil, proximity to commercial areas, and gender. In all three models, significant predictors included both time-varying factors (including activities) and factors fixed over time (including housing characteristics).
This work has been funded wholly or in part by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Towards Reliable and Cost-Effective Ozone Exposure Assessment: Parameter Evaluation and Model Validation Using the Harvard Southern California Chronic Ozone Exposure Study Data 09/23/2003
Xue, J, S V. Liu, A H. Ozkaynak, AND J. D. Spengler. Towards Reliable and Cost-Effective Ozone Exposure Assessment: Parameter Evaluation and Model Validation Using the Harvard Southern California Chronic Ozone Exposure Study Data. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: Accurate assessment of chronic human exposure to atmospheric criteria pollutants, such as ozone, is critical for understanding human health risks associated with living in environments with elevated ambient pollutant concentrations. In this study, we analyzed a data set from a one-year ozone monitoring study of 196 children age 6 to 12 years living in Southern California. For each study subject, detailed questionnaire information on time activity and housing characteristics, and measurements of personal, indoor, and outdoor ozone concentrations were collected. Statistical mixed models with various variance-covariance structures were applied to these data in order to determine important predictors of longitudinal personal ozone exposures. Using an empirical best linear unbiased prediction technique, model predictions were then validated against the field measurements by splitting the full data set randomly into two parts, one for estimating an optimum model and the other for testing its performance. The results of model fitting showed that the most important predictors for personal ozone exposure were: indoor ozone concentrations, central ambient ozone concentrations, outdoor ozone concentrations at subject home, season, gender, time spent outdoors, house fan usage and the presence of gas range in the house. Hierarchal models of personal ozone concentrations, involving a set of predictive variables, based on questionnaire-based data and ozone concentration measurements, indicated the following levels of explanatory power for each of the predictive models of personal ozone exposure: questionnaire data on time activity and housing characteristics alone (rho=0.67); questionnaire variables plus routinely available central ambient ozone concentration measurements (rho=0.76); questionnaire variables plus central site and indoor ozone concentration measurements (rho=0.86). These results provide important information on key predictors of chronic human exposures to ambient ozone for children and offer insights into how to best reliably and cost-effectively predict personal ozone exposures in the future. Furthermore, the techniques and findings derived from this study also have strong implications for selecting the most reliable and cost-effective exposure study designs and modeling approaches for other ambient pollutants, such as fine particulate matter and selected urban air toxics.
This work has been funded in part by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION Sas Formats: Uses and Abuses 09/23/2003
Croghan, C. Sas Formats: Uses and Abuses. Presented at Southeastern SAS User Group, St. Petersburg, FL, September 22-24, 2003.
Abstract: SAS formats are a very powerful tool. They allow you to display the data in a more readable manner without modifying it. Formats can also be used to group data into categories for use in various procedures like PROC FREQ, PROC TTEST, and PROC MEANS (as a class variable). As with many powerful tools, there are some 'gotchas' to be aware of. Formats can crash a program without specific options. They can produce misleading information; this is especially true for picture format. There are many aspects of formats to consider, including 'built-in' or 'user defined' formats. A format may be temporary or permanent. The PUT and INPUT functions can be used to generate new variables using formats. If you have several format libraries, managing the formats can be difficult. The SAS dictionary tables are useful in managing the different formats. Code and output examples demonstrate the various uses and potential abuses of SAS formats.
This paper has been reviewed in accordance with the Untied States Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Sas Formats: Uses and Abuses 09/23/2003
Croghan, C. Sas Formats: Uses and Abuses. Presented at SouthEast SAS Users Group, St. Petersburg, FL, September 21-24, 2003.
Abstract: SAS formats are a very powerful tool. They allow you to display the data in a more readable manner without modifying it. Formats can also be used to group data into categories for use in various procedures like PROC FREQ, PROC TTEST, and PROC MEANS (as a class variable). As with many powerful tools, there are some 'gotchas' to be aware of. Formats can crash a program without specific options. They can produce misleading information; this is especially true for picture format. There are many aspects of formats to consider, including 'built-in' or 'user defined' formats. A format may be temporary or permanent. The PUT and INPUT functions can be used to generate new variables using formats. If you have several format libraries, managing the formats can be difficult. The SAS dictionary tables are useful in managing the different formats. Code and output examples demonstrate the various uses and potential abuses of SAS formats
This presentation has been reviewed in accordance with the United States Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication. SAS and all other SAS Institute Inc. product or service names are registered trademarks of SAS Institute Inc in the USA and other countries. (R) indicates USA registration. Mention of trade names or commercial products does not contitute endorsement or recommendation for use.

PRESENTATION Evaluation of a Remote Exposure Monitoring Strategy for Use in Longitudinal Cohort Studies 09/23/2003
Raymer, J., J. Rench, M. Spruill, L. Thalji, L. Michael, G G. Akland, AND R. Fortmann. Evaluation of a Remote Exposure Monitoring Strategy for Use in Longitudinal Cohort Studies. Presented at International Society of Exposure Analysis Conference (ISEA), Stresa, Italy, September 21-25, 2003.
Abstract: The Federal Government is currently planning a large, prospective birth cohort study known as the National Children's Study that will potentially involve 100,000 children and their families. The observation period will start as close to conception as possible and will continue for 20 years after birth. Given the magnitude and expense of such a large study, sample collection methods which are amenable to acquisition of samples exclusively by the participants themselves followed by direct shipment to the analysis laboratory present a cost-wise alternative to technician-based sampling procedures. In this pilot study, we evaluated the ability of participants in three age cohorts to collect environmental and biological samples according to prescribed protocols. The cohorts consisted of parents and their children in the ages of 0-1 year, 3-5 years, and 6-8 years old. Biological and environmental samples included urine, breast milk/duplicate diet for the 0-1 cohort; urine, cotton sock dosimeters, hair, vacuum dust, and tap water for the 3-5 cohort; and saliva, dust wipe, volatile organic compounds, and humidity/temperature data for the 6-8 cohort. Sample collection instructions and materials were prepared, subjected to evaluation and modification using a test population, and shipped to participants over a 12-month period. Participants were requested to collect the samples, complete questionnaires, and return the samples to RTI within defined time periods. Upon receipt at RTI, the condition of the samples was assessed by visual inspection and the details of the receipt and evaluation were logged into a computer data base; queries were subsequently used to assess compliance. In some cases, chemical analysis was used to further evaluate sample integrity. As an example, of the possible breast milk samples collected from the 0-1 cohort, 89% were collected and 88% of these were acceptable (shipped cold, in sealed containers with the collection date recorded). Similarly, 88% of urine samples were collected and 87% of these were acceptable (shipped cold in the proper container with the collection date recorded). Compliance and results for this and the other cohorts will be presented.
This work has been funded wholly by the United States Environmental Protection Agency under contract number 68D-99-012. This abstract has been subjected to Agency review and approved for publication.

PRESENTATION Optimizing the Paks Method for Measuring Airborne Acrolein 09/23/2003
Herrington, J., L. Zhang, D A. Whitaker, L S. Sheldon, AND J. Zhang. Optimizing the Paks Method for Measuring Airborne Acrolein. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: Airborne acrolein is produced from the combustion of fuel and tobacco and is of concern due to its potential for respiratory tract irritation and other adverse health effects. Active sampling with DNPH-coated solid sorbents has been widely used for sampling airborne carbonyls; however, it is not suitable for sampling acrolein. The Passive Aldehydes and Ketones Sampler (PAKS) is a diffusive, tube-type sampler, which utilizes a dansylhydrazine (DNSH)-coated silica-based bonded C18 sorbent to collect airborne carbonyls. The original PAKS method has been shown to have a collection efficiency of >60% and improved sample stability for acrolein, compared to the DNPH method. However, it is desirable to further increase the PAKS acrolein collection efficiency and improve sample stability.
This work has been funded in part by the US EPA under PO#2D-5806-NAEX. It has been subjected to Agency review and approved for publication.

PRESENTATION Exposures of High Risk Sub-Population to Particles 09/23/2003
Wallace, L A., R W. Williams, J C. Suggs, L S. Sheldon, R B. Zweidinger, A W. Rea, A F. Vette, K W. Leovic, G A. Norris, M S. Landis, C. Stevens, T L. Conner, C. Rhodes, P. A. Lawless, J. Thornburg, L. J. Sally, R. Allen, D. Kalman, J. Kaufman, J. Koenig, T. Larson, T. Lumley, L. Sheppard, K. Brown, J. Sarnat, H. H. Suh, A. Wheeler, P. Koutrakis, M. Lippman, AND M. Kendall. Exposures of High Risk Sub-Population to Particles. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Assessing a Computer Model for Predicting Human Exposure to PM2.5 09/23/2003
McBride, S., R. L. Smith, J. Videk, AND R W. Williams. Assessing a Computer Model for Predicting Human Exposure to PM2.5. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: This paper compares outputs of a model for predicting PM2.5 exposure with experimental data obtained from exposure studies of selected subpopulations. The exposure model is built on a WWW platform called pCNEM, "A PC Version of pNEM." Exposure models created by pCNEM are similar in spirit to the US Environmental Protection Agency's Fortran-based pNEM ("A probabilistic Version of the NAAQS Exposure Model") which was designed to enable regulators to assess the impact of proposed mitigation strategies for CO and O3 on human exposure. The pCNEM platform enables users to develop exposure models online for any environmental hazard for which requisite pollutant, meteorological and source information is available. Pollutant source parameters can be input as random variables to reflect any uncertainty in their values. Exposure models built using pCNEM account for uncertainty in predicted individual exposures by sampling from 24-hour recall time-activity databases for individuals of particular subpopulations. In this way, the exposure model accounts for daily variability in behavior due to time spent in microenviroments as well as meteorological conditions. To assess model performance, estimated personal exposures from pCNEM are compared to measured exposures for residents from USEPA's Research Triangle Park particulate matter panel study as well as the USEPA 1998 Baltimore Particulate Matter Epidemiology-Exposure Study. Overall, the pCNEM model provides more accurate assessments of personal exposures than measurements from ambient monitors or from nearby outdoor monitors. The sensitivity of model predictions to assumptions about microenvironmental parameters, such as air exchange rates, is also examined. This analysis also demonstrates the utility of the freely available pCNEM platform for application in other contexts by the exposure research community.
This work has been partially funded by the United States Environmental Protection Agency under contract 3D-5925-WATX. It has been subjected to Agency review and approved for publication.

PRESENTATION Evaluation of a Remote Exposure Monitoring Strategy for Use in Longatudinal Cohort Studies 09/23/2003
Raymer, J., J. Rench, M. Spruill, L. Thalji, L. Michael, G G. Akland, AND R. Fortmann. Evaluation of a Remote Exposure Monitoring Strategy for Use in Longatudinal Cohort Studies. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Methods of Dealing With Values Below the Limit of Detection Using Sas 09/23/2003
Croghan, C AND P P. Egeghy. Methods of Dealing With Values Below the Limit of Detection Using Sas. Presented at Southern SAS User Group, St. Petersburg, FL, September 22-24, 2003.
Abstract: Due to limitations of chemical analysis procedures, small values cannot be precisely measured. These values are said to be below the limit of detection (LOD). In statistical analyses, these values are often censored and substituted with a constant value, such as half the LOD, the LOD divided by the square root of 2, or zero. This method for handling below-detection values produces a distribution that is the concatenation of two distributions, a uniform distribution for those values below the LOD and the true distribution. Depending upon the percentage of values below the LOD this can produce questionable descriptive statistics. An alternative method uses the distribution of the values above the LOD to estimate the values below the LOD. An example program using the same data is presented calculating the geometric mean, geometric standard deviation, and t-test for both methods to compare the results.
This work has been funded wholly by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products do not constitute endorsement or recommendation for use.

PRESENTATION Sas Formats: Uses and Abuses 09/23/2003
Croghan, C. Sas Formats: Uses and Abuses. Presented at Southeastern SAS User Group, St. Petersburg, FL, September 22-24, 2003.
Abstract: SAS formats are a very powerful tool. They allow you to display the data in a more readable manner without modifying the data. They can also be used to group data into categories for use in various procedures like PROC FREQ, PROC TTEST, and PROC MEANS (as a class variable). As with many powerful tools, there are some 'gotchas' to be aware of. Formats can bomb a program without specific options. They can also produce misleading information especially the picture format. There are many aspects of formats to consider, including 'built in' or 'user defined' formats. A format can be set to be temporary or permanent. The PUT and INPUT functions can be used to generate new variables using formats. If you have several format libraries, managing the formats can be difficult. The SAS dictionary tables are useful in managing the different formats. With code and output examples, this presentation will demonstrate the various uses and potential abuses of SAS formats.
This work has been funded wholly by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products do not constitute endorsement or recommendation for use.

PRESENTATION Methods of Dealing With Values Below the Limit of Detection Using Sas 09/23/2003
Croghan, C AND P P. Egeghy. Methods of Dealing With Values Below the Limit of Detection Using Sas. Presented at Southeastern SAS User Group, St. Petersburg, FL, September 22-24, 2003.
Abstract: Due to limitations of chemical analysis procedures, small concentrations cannot be precisely measured. These concentrations are said to be below the limit of detection (LOD). In statistical analyses, these values are often censored and substituted with a constant value, such as half the LOD, the LOD divided by the square root of 2, or zero. These methods for handling below-detection values two distributions, a uniform distribution for those values below the LOD, and the true distribution. As a result, this can produce questionable descriptive statistics depending upon the percentage of values below the LOD. An alternative method uses the characteristics of the distribution of the values above the LOD to estimate the values below the LOD. This can be done with an extrapolation technique or maximum likelihood estimation. An example program using the same data is presented calculating the mean, standard deviation, t-test, and relative difference in the means for various methods and compares the results. The extrapolation and maximum likelihood estimate techniques have smaller error rate than all the standard replacement techniques. Although more computational, these methods produce more reliable descriptive statistics.
This paper has been reviewed in accordance with the United States Environmental Protection Agency's peer and administrative review policies and approved for presentation and publication.

PRESENTATION Evaluation of Urinary PAH Metabolites as Biomarkers of Exposure to PM2.5 from Combustion Sources 09/23/2003
Lewtas, J, S. Myers, C. Simpson, D. Kalman, AND S. Liu. Evaluation of Urinary PAH Metabolites as Biomarkers of Exposure to PM2.5 from Combustion Sources. Presented at International Symposium on Polycyclic Aromatic Compounds, Amsterdam, The Netherlands, September 21-25, 2003.
Abstract: This study determined the relationship between daily personal exposure to airborne fine particles (PM2.5) and the excretion of urinary PAH metabolites over a 10-day period of repeated measurements. The samples (n=60) were selected from a large series of exposure and health panel studies conducted in Seattle (Liu et al. Env. Health Perspectives, 2003). The sample sets were selected to represent the maximum observed variation in personal exposures over the 10-day panel study period. The PAH metabolites (n = 27) were analyzed by GC/MS/SIM and HPLC/fluorescence. Personal exposures to PM2.5 mass varied from 1.6-66.6 ug/m3 (16.4 mean) and the personal PAH exposures varied from 3.5-14.3 ng/m3 (7.0 mean). Exposures to the wood smoke marker, levoglucosan, ranged from 0.6- 490 ng/m3 (47.5 mean). Outdoor PM2.5 was highly correlated (P < 0.001) with the personal exposures to PM2.5, PAH, and levoglucosan. The urinary PAH metabolites exhibited less variation over the 10 days sampled (1.5-3 fold) than found in the personal exposures. No significant correlation was found between exposure measures and urinary biomarkers within the 10-day period. Although we were not able to determine the half-life, the results are consistent with metabolites (e.g., cotinine) with a relatively long half-life. Previous studies of the half-lives (t 1/2) for urinary elimination of several PAH show evidence of two-phase elimination with a short t 1/2 (4-8h) and a long t 1/2 (12-20h). This study is compared to a study in the Czech Republic where higher personal exposures to PAH were observed than in Seattle and the study was conducted at one time period with 60 subjects. In the Czech study, urinary PAH metabolites were significantly correlated with personal PM2.5 and PAH. These results are also consistent with the longer half-life for urinary PAH metabolites. The use of urinary metabolites and other biomarkers are being explored as tools to apportion human population exposures to PM2.5 from different combustion source emissions.
This work has been funded by the United States Environmental Protection Agency. This work has been subjected to Agency review and approved for publication.


PRESENTATION Comparing Pesticide Transfers from Residential Surfaces Using Transferable Residue Sampling Techniques and Video-Fluorescent Imaging 09/23/2003
Nishioka, M. G., E A. CohenHubal, W. Ivancic, M. Morara, S. Bortnick, K. Andrews, J. Sowry, A. Gregg, AND M. McCauley. Comparing Pesticide Transfers from Residential Surfaces Using Transferable Residue Sampling Techniques and Video-Fluorescent Imaging. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Exposures of High Risk Sub-Populations to Particles 09/23/2003
Wallace, L A., R W. Williams, J C. Suggs, L S. Sheldon, R B. Zweidinger, A W. Rea, A F. Vette, K W. Leovic, C. Stevens, C Croghan, C. Rhodes, P. A. Lawless, J. Thornburg, L. Liu, R. Allen, D. Kalman, J. Kaufman, J. Koenig, T. Larson, T. Lumley, L. Sheppard, K. Brown, J. Sarnat, H. H. Suh, A. Wheeler, AND P. Koutrakis. Exposures of High Risk Sub-Populations to Particles. Presented at International Society for Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Bioavailability and Toxicity of Metals in Soils 09/22/2003
Bradham, K. Bioavailability and Toxicity of Metals in Soils. Presented at NCCU Environmental Information Seminar Series, Durham, NC, September 15, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION USEPA Research Activities to Characterize Children's Environmental Exposures 09/22/2003
CohenHubal, E A. USEPA Research Activities to Characterize Children's Environmental Exposures. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: Given the vulnerability of children to effects from environmental exposures, understanding links between children's health and environmental exposures is critical. In recent years, significant research has been initiated at USEPA to characterize children's exposures.
In 1996, Congress enacted two statutes requiring USEPA consider children when setting standards: the Food Quality Protection Act and the Safe Drinking Water Act Amendments. Subsequently, USEPA expanded research in this area through 1998 and 2000 initiatives on children's environmental health. In 2000, USEPA published its Strategy for Research on Environmental Risks to Children. To address important gaps identified in the strategy, USEPA conducts a variety of research on children's exposure.

Efforts include development of models, methods, and data to assess ways that children are exposed to environmental stressors. Field studies are being conducted to measure children's exposures in their homes and daycares. CTEPP, a study of 260 preschool-age children, has been completed and data are being analyzed to identify important exposure factors. A longitudinal study of 80-100 infants and toddlers has been designed to assess exposures to pesticides, phthalates, and BFRs.

USEPA sponsors additional research through STAR Grants. These projects focus on children's risks from exposures to air pollution, PCBs, ECDs, and pesticides. USEPA is also collaborating with the chemical industry to identify data needs for characterizing children's risks. Through VCCEP, 35 companies volunteered to sponsor assessments for 20 chemicals measured in human tissues and the environment. Finally, USEPA is collaborating with other Federal agencies to plan and conduct a national study of environmental effects on children (NCS). Methods development studies are underway in support of NCS.

As a result of these initiatives, important data have been developed. However, significant gaps remain in our ability to estimate exposures. Important needs include tools for classifying children's behaviors and approaches for collecting and interpreting biomarkers.

This work has been funded wholly or in part by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION Optimizing the Paks Method for Measuring Airborne Acrolein 09/22/2003
Herrington, J., L. Zhang, D A. Whitaker, L S. Sheldon, AND J. Zhang. Optimizing the Paks Method for Measuring Airborne Acrolein. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: Airborne acrolein is produced from the combustion of fuel and tobacco and is of concern due to its potential for respiratory tract irritation and other adverse health effects. DNPH active-sampling is a method widely used for sampling airborne aldehydes and ketones (carbonyls); however, based on our tests it is not suitable for sampling acrolein, because of its low collection efficiency (20%) and poor stability. The Passive Aldehydes and Ketones Sampler (PAKS) is a diffusive, tube-type sampler, which utilizes a dansylhydrazine (DNSH)-coated silica-based bonded C18 sorbent to collect airborne carbonyls. Carbonyls react with DNSH to form their corresponding derivatives that are retained on the sorbent. The derivatives are subsequently extracted and quantified using an HPLC-fluorescence technique. The PAKS method has a collection efficiency of >60% and an improved DNSH-derivative stability for acrolein compared to DNPH-derivative stability. However, it is still desirable to increase the PAKS acrolein collection efficiency and derivative stability. The addition of pH buffers (citric acid/sodium citrate), a polymerization inhibitor (hydroquinone), and an alternative hygroscopic agent (1,3-butanediol) to the derivatization solution, are being evaluated for their effectiveness in improving acrolein collection efficiency and stability on the collection medium (C18 sorbent). The evaluation is being conducted subsequent to 24 - 48 hours of exposure and after 0, 1, 2, 4, 7, and 11 days of storage at 4oC. The coating solution containing optimal amounts of buffer solution, hydroquinone, and 1,3-butanediol will be determined after a variety of tests. Preliminary results indicate that the PAKS acrolein collection efficiency and stability can be improved with a combination of the optimal parameters mentioned above.
This work has been funded wholly or in part by the US EPA under PO#2D-5806-NAEX . It has been subjected to Agency review and approved for publication.


PRESENTATION Assessing Population Exposures to Multiple Air Pollutants Using a Mechanistic Source-to-Dose Modeling Framework 09/22/2003
Georgopoulos, P. G., S. W. Wang, V. M. Vyas, Q. Sun, P. Shade, Y. C. Yang, J M. Burke, R. Vedantham, AND A H. Ozkaynak. Assessing Population Exposures to Multiple Air Pollutants Using a Mechanistic Source-to-Dose Modeling Framework. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: The Modeling Environment for Total Risks studies (MENTOR) system, combined with an extension of the SHEDS (Stochastic Human Exposure and Dose Simulation) methodology, provide a mechanistically consistent framework for conducting source-to-dose exposure assessments of multiple pollutants, for either individuals or populations. Typical simulations employing the Population Based Modeling (PBM) option consist of the following steps: (1) Characterization of ambient pollution levels through a combination of environmental model predictions and field data; (2) Estimation of local outdoor levels of contaminants, which characterize the ambient air of an administrative unit (e.g. census tract); (2) Characterization of levels and temporal profiles of contaminants in various residential and occupational microenvironments; (3) Selection of a fixed-size sample population that statistically reproduces essential demographics (age, gender, race, occupation) of the population unit used (e.g. census tract) in the assessment; (4) Development of activity event sequences for each member of the sample population from diaries or by matching attributes to entries of USEPA's Consolidated Human Activity Database (CHAD); (5) Calculation of physiological intake rates for the members of the sample population, reflecting/combining physiological attributes and activities pursued; (6) Combination of intake rates with microenvironmental levels of contaminants to assess exposures; (7) Averaging of exposure estimates over appropriate time-intervals to produce appropriate exposure metrics; (8) Development of appropriate estimates of dose, reflecting physiological, biochemical, and activity factors; (9) "Extrapolation" of results to the population of concern. A series of case studies is presented, demonstrating simultaneous population exposures to multiple air pollutants such as PM2.5, O3, and air toxics.
Disclaimer: This work had been funded in part by the US Environmental Protection Agency under Cooperative Agreement # EPAR-827033 to Environmental and Occupation Health Sciences Institute. It has been subjected to Agency review and approved for publication.

PRESENTATION Sheds-PM: A Population Exposure Model for Predicting Distributions of PM Exposure and Dose from Both Outdoor and Indoor Sources 09/22/2003
Burke, J M., R. Vedantham, T R. McCurdy, J Xue, AND A H. Ozkaynak. Sheds-PM: A Population Exposure Model for Predicting Distributions of PM Exposure and Dose from Both Outdoor and Indoor Sources. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: The US EPA National Exposure Research Laboratory (NERL) has developed a population exposure and dose model for particulate matter (PM), called the Stochastic Human Exposure and Dose Simulation (SHEDS) model. SHEDS-PM uses a probabilistic approach that incorporates both variability and uncertainty to predict distributions of PM exposure, inhaled dose, and deposited dose for a specified population. SHEDS-PM estimates the contribution of PM from both outdoor and indoor sources (e.g., cigarette smoking, cooking) to total personal PM exposure and dose.
SHEDS-PM generates a simulation population using US Census demographic data for the user-specified population, and randomly assigns each simulated individual an appropriate activity diary from NERL's Consolidated Human Activity Database (CHAD). A time series of PM exposure for each individual is determined from calculated microenvironmental PM concentrations and the time spent in each microenvironment. Inhaled dose is determined using activity-specific ventilation rates, and deposited dose is estimated using a conventional pulmonary deposition model (total deposited to three regions of the lung). Output from the SHEDS-PM model includes distributions of exposure and dose for the specified population, as well as exposure and dose profiles for each simulated individual.

An executable version of the SHEDS-PM model with a graphical user interface (GUI) is now publicly available. The GUI allows the user to define the modeling scenario of interest, to select input data files, and to modify various input parameters. The user is only required to provide ambient outdoor PM concentration data (measured or modeled), and to specify the population of interest.

This work has been partially funded by the United States Environmental Protection Agency under Contract No. 68-W-99-002 to Science Applications International Corporation. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.


PRESENTATION Levels of Chlorpyrifos and Its Degradation Product 3,5,6-Trichloro-2-Pyridinol in the Homes, Day Care Centers, and Urine of 130 North Carolina Preschool Children 09/22/2003
Morgan, M K., L S. Sheldon, N. K. Wilson, J. C. Chuang, C. Lyu, C Croghan, G L. Robertson, P A. Jones, M. C. Brinkman, AND R C. Fortmann. Levels of Chlorpyrifos and Its Degradation Product 3,5,6-Trichloro-2-Pyridinol in the Homes, Day Care Centers, and Urine of 130 North Carolina Preschool Children. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: This study examined the aggregate exposures of 257 preschool children to pollutants commonly found in their everyday environments. A primary objective was to identify important sources and routes that contribute to the children's exposures in these environments. Participants were recruited randomly from selected homes and day care centers in 12 North Carolina (NC) and Ohio counties. Monitoring was performed over a 48-hr period at the children's homes and/or day care centers. Samples that were collected included diet, water, air, urine, dust, soil, and surface wipes. The samples were analyzed by GC/MS for over 50 pollutants including chlorpyrifos and its degradation product 3,5,6-trichloro-2-pyridinol (TCP). Here we report preliminary results for levels of chlorpyrifos and TCP in multimedia samples collected at homes (n=130) or day care centers (n=13) of 130 NC preschool children. The median levels of chlorpyrifos and TCP measured at homes were 5.1 and 4.6 ng/sample (hand wipes), 6.1 and 1.9 ng/m3 (indoor air), 138.6 and 95.8 ng/g (dust), and 0.2 and 0.6 ng/g (soil), respectively. At day cares, the median levels of chlorpyrifos and TCP were 4.4 and 2.9 ng/sample (hand wipes), 3.2 and 0.9 ng/m3 (indoor air), 142.2 and 62.5 ng/g (dust), and 0.2 and 0.1 ng/g (soil), respectively. The median TCP concentration in the children's urine was 5.3 ng/mL. The results suggest that TCP may not be a useful urinary biomarker of exposure for children exposed to low levels of chlorpyrifos in their everyday environment.
This work has been funded wholly by the United States Environmental Protection Agency under contract #68-D-99-011 to Battelle. It has been subjected to Agency review and approved for publication.

PRESENTATION Communication of Risk: Nccu Environmental Information Seminar Series 09/15/2003
Communication of Risk: Nccu Environmental Information Seminar Series. Presented at NCCU Environmental Information Seminar Series, Durham, NC, September 9, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Persistent Organic Pollutants in Dusts That Settled at Indoor and Outdoor Locations in Lower Manhattan After 11 September 2001 09/10/2003
Offenberg, J, S. Eisenreich, L. C. Chen, M. D. Cohen, G. Chee, C. Prophete, J. Q. Xiong, C. Quan, X. Lou, M. Zhong, J. Gorczynski, L. M. Yiin, V. Illacqua, C. E. Weisel, AND P. J. Lioy. Persistent Organic Pollutants in Dusts That Settled at Indoor and Outdoor Locations in Lower Manhattan After 11 September 2001. Presented at American Chemical Society National Meeting, New York, NY, September 10, 2003.
Abstract: The explosion and collapse of the World Trade Center (WTC) was a catastrophic event that produced an aerosol impacting many workers, residents and commuters during the first few days after September 11th, 2001. During the initial days that followed, fourteen bulk samples of the settled dust were collected at locations surrounding the epicenter of the disaster. These samples were analyzed for persistent organic pollutants will be described, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and select organo-chlorine pesticides. The Z86-PCBs comprising less than 0.001% by mass of the bulk dusts, indicating that PCBs were of limited significance. Likewise, Chlordanes, Hexachlorobenzene, Heptachlor, 4,4'-DDE, 2,4'-DDT, 4,4'-DDT and Mirex were found at low concentrations in the bulk samples. Conversely, the Z37-PAHs comprised up to nearly 0.04% (0.005 to 0.039%) by mass of the bulk settled dust in the six bulk samples. In addition, twelve bulk samples of the settled dust were collected at indoor locations surrounding the epicenter of the disaster, including one sample from a residence that had been cleansed and was once again occupied. The Z86-PCB concentrations, comprising less than one part per million by mass of the bulk in the two samples analyzed, indicate that PCBs were also of limited significance in the dust that settled at indoor locations. Likewise, Hexachlorobenzene, Heptachlor, 4,4'-DDE, 2,4'-DDT, 4,4'-DDT and Mirex were found at even lower concentrations in the bulk indoor samples. Conversely, Z37-PAHs comprised up to 0.04% (<0.005 to 0.036%) by mass of the impacted bulk indoor dust samples. Analysis of one sample of indoor dusts collected from a vacuum cleaner of a rehabilitated home shows markedly lower PAH concentrations (< 0.0005 mass %), as well as differing relative contributions for individual compounds. In addition to similar concentrations, comparison of PAH concentration patterns shows that dusts that settled indoors are chemically similar to dusts found at outdoor locations and that PAH analyses may be used in identifying dusts of WTC origin at indoor locations, along with ascertaining further needs for cleaning.
This work has been funded in part of the United States Environmental Protection Agency. It has not undergone agency review and does not represent the views of the US EPA. Mention of trade names or commercial products does not constitute endorsement of recommendation for use.

PRESENTATION Polycyclic Aromatic Hydrocarbons (PAHs) and Other Semi-Volatile Organic Compounds Collected in New York City in Response to the Events of 9/11 09/08/2003
Swartz, E, L Stockburger, AND D A. Vallero. Polycyclic Aromatic Hydrocarbons (PAHs) and Other Semi-Volatile Organic Compounds Collected in New York City in Response to the Events of 9/11. Presented at 226th American Chemical Society National Meeting, New York, NY, September 7-11, 2003.
Abstract: Concentrations of over 60 non-polar semi-volatile and non-volatile organic compounds were measured in Lower Manhattan, New York using a high capacity Integrated Organic Gas and Particle Sampler, after the initial destruction of the World Trade Center. The results indicate that the remaining air plumes from the disaster site were comprised of many pollutants and classes and represent a complex mixture of biogenic (wood-smoke) and anthropogenic sources. This mixture includes compounds that are typically associated with fossil fuel emissions and their combustion products. The molecular markers for these emissions include the high molecular weight PAHs, the n-alkanes, a Carbon Preference Index ~ 1 (odd carbon:even carbon ~ 1), as well as pristane and phytane as specific markers for fuel oil degradation. These results are not unexpected considering the large number of diesel generators and outsized vehicles used in the removal phases. The mixture also includes emissions of burning and remnant materials (e.g. carpets, furniture, wallboard and other flammable and aerosol-producing materials) from the WTC site. The molecular markers for these emissions include retene and 1,4a-dimethyl-7-(methylethyl)-1,2,3,4,9,10,10a,4a-octahydrophenanthrene which are typically biogenic in origin. In addition, the compound 1,3-diphenyl propane [1',1'-(1,3-propanediyl)bis-benzene] was observed and, to our knowledge, this species has not previously been reported from ambient sampling. It has been associated with polystyrene, which are believed to be in abundance at the WTC site. These emissions lasted for at least three weeks (9/26/01-10/20/01) after the initial destruction of the WTC.
This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Semi-Volatile Organic Acids and Other Polar Compounds Collected in New York City in Response to the Events of 9/11 09/08/2003
Swartz, E, L Stockburger, M D. Hays, AND N. D. Smith. Semi-Volatile Organic Acids and Other Polar Compounds Collected in New York City in Response to the Events of 9/11. Presented at 226th American Chemical Society National Meeting, New York, NY, September 7-11, 2003.
Abstract: Concentrations of over 25 polar semi-volatile and non-volatile organic compounds were measured in Lower Manhattan, New York using a high capacity Integrated Organic Gas and Particle sampler, after the initial destruction of the World Trade Center. The polar organic compounds in ambient fine aerosols were sampled diurnally and daily between 9/26/01-10/24/01. To the best of our knowledge, these are the first data quantifying the organic acids in aerosols from Ground Zero emissions. The polar compounds were collected using a recently introduced high capacity Integrated Organic Gas and Particle (HiC IOGAP) sampler [1]. This work in part shows the effectiveness of the HiC IOGAP sampler for the collection of different organic acid species and levoglucosan, an important molecular marker for burning cellulose. Polar compounds were identified with GC/MS following derivaterization by diazomethane and BSTFA.
Ion chromatography and X-ray fluorescence methods were implemented to determine the anion, cation, and elemental constituents in aerosol emissions from Ground Zero. These analyses indicated whether alkaline cementitious materials are present in the fine aerosol. Airborne cement fines may result in atmospheric scavenging of organic acids via an acid-base reaction. The presence of such cementitious species may also indicate some resuspension of the settled dust, since a significant cementitious component within the settled dust was confirmed by X-ray diffraction (XRD).

This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Volatile Organic Compounds Measurements in New York City in Response to the Events of 9/11 09/07/2003
Seila, R L., E Swartz, W A. Lonneman, AND D A. Vallero. Volatile Organic Compounds Measurements in New York City in Response to the Events of 9/11. Presented at American Chemical Society, New York, NY, September 7-11, 2003.
Abstract: From September 22, 2001 through February 2002, ambient air was sampled in lower Manhattan, New York at three sites within a block of ground zero and at a fourth site 500-m northwest of the World Trade Center. Over 190 grab samples were collected in evacuated, electro-polished stainless steel canisters. In addition, from mid-February until the end of April, 24-h samples were collected at three other sites near ground zero. Over 100 volatile organic compounds (VOCs) ranging from C2 to C10+ were determination by capillary gas chromatography-flame ionization detection with cryogenic preconcentration. Some samples were also analyzed using gas chromatography-mass spectral detection. In general VOC concentrations were highest at the site north of ground zero followed by the southerly and northwest sites. Some compounds, for example ethylbenzene, showed a trend with maximum concentrations at the beginning of the study period followed by a decrease to background levels around mid-November.
This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Human Exposure Modeling for Air Toxics: Concepts, Methods, and Tools 08/28/2003
Ozkaynak, A H., J M. Burke, AND S. Graham. Human Exposure Modeling for Air Toxics: Concepts, Methods, and Tools. Presented at EPA Region 1 Meeting, Boston, MA, August 28, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Human Exposure Modeling: Concepts, Methods, and Tools 08/28/2003
Ozkaynak, A H., J M. Burke, AND S E. Graham. Human Exposure Modeling: Concepts, Methods, and Tools. Presented at EPA Region 1 Meeting, Boston, MA, August 28, 2003.
Abstract: Understanding human exposure is critical when estimating the occurrence of deleterious effects that could follow contact with environmental contaminants. For many pollutants, the intensity, duration, frequency, route, and timing of exposure is highly variable, particularly when human activity patterns are considered simultaneously with variant chemical concentrations. Basic exposure concepts, exposure modeling methods, and available tools are discussed to answer questions surrounding the utility and application of exposure models in a variety of risk-based regulatory scenarios. The discussion includes multipathway exposure assessments and details the stochastic/probabilistic modeling approach utilized by the US EPA's National Exposure Research Laboratory (NERL).
NERL is developing the Stochastic Human Exposure and Dose Simulation (SHEDS) model for estimating exposure to pesticides, particulate matter, and air toxics. SHEDS is a physically-based probabilistic model intended for improving estimates of human exposure and dose to multimedia, multipathway pollutants. A two-dimensional Monte-Carlo simulation methodology is incorporated to characterize population distributions of exposure and dose by explicitly quantifying the variability and the uncertainty in model inputs, parameters, and outputs. A SHEDS model developed for air toxics applications (SHEDS-ATOX) currently estimates an individual's exposure to benzene in several specific microenvironments (e.g., indoors at home) using ambient air toxic concentrations and various exposure factors (e.g., residential air exchange rate). Algorithms specific to mobile source pollutants are also included, such as exposure to chemicals while refueling an automobile and infiltration of air inside a residence from an attached garage. In addition, SHEDS-ATOX estimates dermal exposure from multiple pathways and dietary exposure through ingestion of foodstuffs. In all SHEDS models, the time series of exposure is preserved and allows for the identification of critical exposure factors to assist in determining how to reduce human exposure to chemicals.

This work has been wholly funded by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION Bisphenol-a and Phthalate Esters: Potential Sources of Resin Components in the Everyday Environments of Preschool Children 08/12/2003
Morgan, M K., L S. Sheldon, N. K. Wilson, J. C. Chuang, C. Lyu, C Croghan, P A. Jones, AND R C. Fortmann. Bisphenol-a and Phthalate Esters: Potential Sources of Resin Components in the Everyday Environments of Preschool Children. Presented at Region/ORD Emerging Pollutants Workshop, Chicago, IL, August 11-14, 2003.
Abstract: The Children's Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study examined the aggregate exposures of 257 preschool children to pollutants commonly found in their everyday environments. A primary objective of the CTEPP study was to identify important sources that contribute to the children's exposures in these environments. Participants were recruited randomly from selected homes and day care centers in six North Carolina and six Ohio counties. Monitoring was performed over a 48-hr period at the children's homes and/or day care centers. Samples that were collected included diet, water, air, dust, soil, and surface wipes. The samples were extracted and analyzed by gas chromatography/mass spectrometry for over 50 pollutants including bisphenol-A (BPA) and two phthalate esters, dibutyl phthalate (DBP) and benzyl butyl phthalate (BBP). BPA is an important component of polycarbonate plastics and epoxy resins frequently used in products such as reusable bottles, digital media, and as protective liners in metal cans. Phthalate esters are commonly used as plasticizers in vinyl products (e.g., floor tiles, children's toys, and carpet backings) and as solvents/fixatives in personal care products. Here we have reported the preliminary results for levels of BPA, DBP, and BBP in multimedia samples collected at homes (n=129) and day care centers (n=13) of 130 North Carolina preschool children. Both phthalate esters were detected (100%) the most often in indoor floor dust samples. BPA was detected (95%) the highest in hand wipe samples. The median levels of BPA, DBP, and BBP measured in homes were 0.2, 0.6 and 0.9 ug/sample (hand wipes), 0.001, 0.3 and 0.05 ug/m3 (indoor air), 0.02, 5.9 and 17 ug/g (indoor carpet dust), and 0.003, 0.09 and 0.07 ug/g (solid food), respectively, after background correction. At day care centers, the median levels of BPA, DBP, and BBP were 0.8, 0.6 and 0.7 ug /sample (hand wipes), 0.001, 0.3 and 0.05 ug/m3 (indoor air), 0.02, 16 and 47 ug/g (indoor carpet dust), and 0.004, 0.09 and 0.07 ug/g (solid food), respectively. These results show that these pollutants are measurable in several media at both homes and day care centers. In addition, the median DBP and BBP levels in indoor carpet dust samples were at least two times greater at day care centers than at homes. The results suggest that these preschool children were potentially exposed to low levels of BPA, DBP, and BBP in their everyday environments.
This work has been funded wholly by the United States Environmental Protection Agency under contract #68-D-99-011 to Battelle. It has been subjected to Agency review and approved for publication.

PRESENTATION A Comparative Investigation of the Influence of Dermal Appendages (Hair Follicles) on the Percutaneous Absorption of Organophosphorus (Op) Insecticides Using QSAR and PBPK/Pd Models for Human Risk Assessment 07/23/2003
TORNERO-VELEZ, R, C C. Dary, J. B. Knaak, F W. Power, AND M Dellarco. A Comparative Investigation of the Influence of Dermal Appendages (Hair Follicles) on the Percutaneous Absorption of Organophosphorus (Op) Insecticides Using QSAR and PBPK/Pd Models for Human Risk Assessment. Presented at International Society of Exposure Analysis, Stresa, Italy, September 21-25, 2003.
Abstract: The successful use of the Exposure Related Dose Estimating Model (ERDEM) for assessment of dermal exposure of humans to OP pesticides requires the input of representative and comparable input parameters. In the specific case of dermal exposure, regional anatomical variation in the rate of percutaneous absorption must be considered in order to make reasonable estimates of absorbed dose. To accomplish this assessment, estimates of hair follicle density were generated for various regions of the body including the scalp, forearms and hands. Quantitative Structure Activity Relationships (QSAR) were used to obtain Kp values (cm/h) for percutaneous absorption, skin/water and tissue/blood partition coefficients, and metabolic parameter values (Vmax and Km). Inhibition of the B-esterases (acetylcholin-, butyrylcholin- and carboxyl-) was used as the dose metric for the determination of margins of exposure (MOE) for exposure scenarios where various anatomical areas of the body may be implicated. Modeling results show the importance of considering regional variation in hair volume and density in exposure and risk assessment.
This work has been funded by the United States Environmental Protection Agency under Interagency Assistance Agreement (DW 47944301) to GSA. It has been subjected to Agency review and approved for publication.

PRESENTATION The Influence of Particulate Matter of Ambient Origin Upon Indoor Residential Mass Concentrations Involving Sensitive Subpopulations-Results from Longitudinal Panel Studies 07/22/2003
Williams, R W., J C. Suggs, A W. Rea, L S. Sheldon, A F. Vette, J M. Burke, C Croghan, K Leovic, J P. Creason, D Walsh, C. Rhodes, J. Thornburg, P. A. Lawless, A. Ejire, M. Herbst, AND W. Sanders Jr. The Influence of Particulate Matter of Ambient Origin Upon Indoor Residential Mass Concentrations Involving Sensitive Subpopulations-Results from Longitudinal Panel Studies. Presented at PM Indoor Air Quality and Engineering Solutions Symposium, Research Triangle Park, NC, July 21-23, 2003.
Abstract: The US EPA has completed field data collections from a series of longitudinal particulate matter (PM) exposure panel field studies. These studies were conducted in Baltimore, Maryland (1998), Fresno, California (1999), and Research Triangle Park (RTP), North Carolina (2000-2001) and were designed to evaluate factors influencing the contribution of particulate matter of ambient origin upon residential indoor settings. Residences from various non-smoking sub-populations that might be sensitive to ambient particulate matter exposures (e.g., the elderly, hypertensive, cardiac impaired) were investigated. Geographical settings, seasons, and housing stock were also important variables. The studies were of sufficient duration (28 days) and size (20-60 individuals) to investigate both longitudinal and cross-sectional correlations between personal, residential indoor, residential outdoor, and ambient PM measurements. Residential measurements of PM2.5 and PM10 were routinely collected. Extensive daily questionnaires were used to gather information on household practices and factors that might influence particle infiltration. Mean indoor/outdoor PM2.5 mass concentration ratios from all of the study locations were observed to range from 0.49 to 1.12. Data from the RTP study, where 38 private homes were monitored in comparison to the communal settings (retirement facilities) in Baltimore and Fresno, permitted a more detailed examination of particulate matter indoor/outdoor ratios. The RTP results revealed a wide range in the magnitude and variability of individual residential indoor PM2.5 24-hr average PM mass concentrations (4 -119 ug/m3) over the course of one year.
This research was sponsored by U.S. EPA contracts 68-D-99-012 and 68-D5-0040 to RTI International and cooperative agreement CR-828186-01-0 to Shaw University. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

PRESENTATION Monitoring Methods Adaptable to Vapor Intrusion Monitoring USEPA Compendium Methods to-15, to-15 Supplement (Draft), and to-17 07/22/2003
McClenny, W A., K. D. Oliver, H. H. Jacumin Jr., AND E. H. Daughtrey Jr. Monitoring Methods Adaptable to Vapor Intrusion Monitoring USEPA Compendium Methods to-15, to-15 Supplement (Draft), and to-17. Presented at Specialty Conference and Exhibition on Indoor Air Quality Problems and Engineering Solutions, Durham, NC, July 21-23, 2003.
Abstract: USEPA ambient air monitoring methods for volatile organic compounds (VOCs) using specially-prepared canisters and solid adsorbents are directly adaptable to monitoring for vapors in the indoor environment. The draft Method TO-15 Supplement, an extension of the USEPA Method TO-15, highlights the lowering of VOC detection limits to single digit parts-per-trillion by volume (pptv) concentrations using canister-based sampling along with analysis by benchtop GC/MS . Diffusive sampling onto adsorbent-filled sampling tubes similar to those described in TO-17 is being evaluated for sampling periods of 24 hours and less. Initial results indicate a linearity of response at the 2 parts-per-billion by volume (ppbv) level and excellent duplicate runs.
This presentation has been subjected to the Agency's peer and administrative review, and it has been approved for publication. Mention of trade names or commercial products does not constitute endorsement of recommendation for use.


PRESENTATION Influence of Residential Hvac Duty Cycle on Indoor Air Quality 07/21/2003
Thornburg, J., C. Rodes, P. A. Lawless, C. Stevens, AND R W. Williams. Influence of Residential Hvac Duty Cycle on Indoor Air Quality. Presented at 2003 AWMA Indoor Air Quality PM Meeting, Research Triangle Park, NC, July 21, 2003.
Abstract: Measurements of duty cycle, the fraction of time the heating and cooling (HVAC) system was operating, were made in homes during the spring season of the RTP Particulate Matter Panel Study and the Tampa Asthmatic Children's Study. A temperature sensor/logger placed on an outlet vent monitored changes in temperature as the HVAC system cooled or heated the residence. Temperature data were compiled into a database and duty cycles were assessed from temperature step changes. Duty cycle measurements provided insight into the relationship between 24-hr integrated air exchange rate and indoor particulate matter (PM) concentrations as well as real-time indoor-outdoor PM ratios.
Statistically significant relationships between duty cycle-ambient temperature and duty cycle-air exchange rate were observed. Noticeable increases in duty cycle were noted in both studies as the mean ambient temperature increased or decreased around 65 degrees F. Differences in personal comfort preferences, building characteristics, and HVAC system operational efficiency contributed to the data variability. These same factors contributed to variability in the relationship between duty cycle and air exchange rate. HVAC heating mode duty cycle was positively correlated with the air exchange rate due to the positive temperature differential between inside and outdoors; whereas a negative temperature differential between inside and outdoors resulting from HVAC operation in cooling mode yielded a negative correlation with air exchange rate.

The relationship between duty cycle and 24-hour integrated PM indoor-outdoor ratio was confounded by the presence of strong indoor sources when the HVAC system was not operating and by the brief intervals (usually 10 minutes) of HVAC system operation. Individual cases when strong indoor sources were not present showed a definite correlation between duty cycle and integrated PM2.5 indoor/outdoor ratio (R2 = 0.36, p <0.01). Real-time indoor-outdoor PM data collected for a participant that operated their HVAC system for 30-minute intervals showed a maximum 90% reduction in indoor PM concentration at a rate greater than expected for deposition losses alone. The increased PM loss rate was attributed to the HVAC system. The usefulness of the duty cycle data in interpreting PM indoor-outdoor ratios would be improved if the HVAC system (filter efficiency, leaks) and building characteristics (penetration factor) were characterized in detail.

This work has been partially funded by the United States Environmental Protection Agency under contract 68-D-99-012 to the Research Triangle Institute. It has been subjected to Agency review and approved for publication.

PRESENTATION A Pilot Study of the Influence of Residential Hac Duty Cycle on Indoor Air Quality 07/21/2003
Thornburg, J., C. Rodes, P. A. Lawless, C Stevens, AND R W. Williams. A Pilot Study of the Influence of Residential Hac Duty Cycle on Indoor Air Quality. Presented at AWMA Particulate Matter Indoor Air Quality and Envineering Solutions Symposium, Research Triangle Park, NC, July 21, 2003.
Abstract: A simple methodology was developed to collect measurements of duty cycle, the fraction of time the heating and air conditioning (HAC) system was operating inside residences. The primary purpose of the measurements was to assess whether the HAC duty cycle was related to reductions in indoor particulate matter (PM) concentrations. A miniature temperature logger placed on an HAC outlet vent monitored changes in temperature as the system cooled or heated the residence. Temperature step changes signaling duty cycle periods were identified using spreadsheet macros. Parallel measurements of 24-hour integrated air exchange rates (AERs) and indoor PM2.5 and PM10 concentrations were collected to determine relationships with the duty cycle. The mild temperatures (mean = 18.7 degrees C) present during the Spring season of the RTP PM Panel Study and personal comfort preferences caused low and variable daily duty cycles (mean = 0.061, std. dev. = 0.054) in both heating and cooling mode. Warmer ambient temperatures during the Fall season of the Tampa Asthmatic Children Study (TACS) resulted in cooling-only HAC operation, with a higher mean duty cycle of 0.21 (std. dev. = 0.11). Statistically significant linear relationships were observed between daily average duty cycle and the ambient temperature for both studies. Duty cycle exhibited a strong diurnal pattern commensurate with ambient temperature fluctuations. Duty cycles were positively associated with the residence AERs for heating-mode operations, but negatively associated when operating in cooling mode. Personal preferences contributed to the variability in the relationship between duty cycle and air exchange rate. The relationship between duty cycle and PM2.5 or PM10 indoor-outdoor ratios were not statistically significant. The association of duty cycle with indoor-outdoor ratio was confounded by the short time span (mean of 10.3 minutes for the TACS) of HAC system operation and the presence of strong indoor sources altering the indoor concentration levels.
This research was sponsored by U.S. EPA contract 68-D-99-012 to RTI International. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use.

PRESENTATION The Influence of Particulate Matter of Ambient Origin Upon Indoor Residential Mass Concentrations Involving Sensitive Subpopulations: Results from Longitudinal Panel Studies 07/21/2003
Williams, R W., J C. Suggs, A W. Rea, L S. Sheldon, A F. Vette, J M. Burke, C Croghan, K Leovic, J P. Creason, D Walsh, C. Rodes, J. Thornburg, P. A. Lawless, A. Ejire, M. Herbst, AND W. Sanders Jr. The Influence of Particulate Matter of Ambient Origin Upon Indoor Residential Mass Concentrations Involving Sensitive Subpopulations: Results from Longitudinal Panel Studies. Presented at 2003 AWMA Indoor Air Quality PM Meeting, Research Triangle Park, NC, July 21, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Influence of Residential Hvac Duty Cycle on Indoor Air Quality 07/18/2003
THORNBURG, J., C. E. RODES, P. LAWLESS, C. D. STEVENS, AND R. W. WILLIAMS. Influence of Residential Hvac Duty Cycle on Indoor Air Quality. Presented at 2003 AWMA Indoor Air Quality Meeting, Durham, NC, NC, July 21, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Regional Scale Assessments and the Atmospheric Fate and Transport of Air Toxics: Cmaq 07/16/2003
Luecken, D J. Regional Scale Assessments and the Atmospheric Fate and Transport of Air Toxics: Cmaq. Presented at Air Toxics Risk Assessment Modeling Tools Symposium, Chicago, IL, July 15-17, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Human Exposure Modeling: Concepts, Methods, and Tools 07/16/2003
Burke, J M., S E. Graham, AND T. Palma. Human Exposure Modeling: Concepts, Methods, and Tools. Presented at Air Toxics Risk Assessment Modeling Tools Symposium, Chicago, IL, July 15-17, 2003.
Abstract:
This work has been funded wholly by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for presentation.

PRESENTATION EPA's Human Exposure Measurement Program 06/24/2003
Sheldon, L S. EPA's Human Exposure Measurement Program. Presented at American Chemistry Council Long-Range Research Initiative Annual Science Meeting, Herndon, VA, June 24-25, 2003.
Abstract: The goal of NERL's Exposure Research Program is to improve the scientific basis for conducting human exposure assessments that are part of the EPA's risk assessment, risk management and compliance process. Overall, we aim to address aggregate and cumulative exposures that pose the greatest risks to the American public. The program addresses exposures for the general population and susceptible subpopulations including children, asthmatics, and the elderly. A systemic approach is taken to planning and implementing our research. First, the highest priority regulatory needs for exposure data are identified. An iterative process between methods development, measurements, and modeling is then used to develop and conduct the research. Preliminary models are developed to identify key data gaps and uncertainties. Specific laboratory or field measurement studies are designed to:
1. Identify those chemicals, pathways, and activities that represent the highest potential exposures;

2. Systematically identify the data (exposure factors) required to estimate exposure by each route;

3. Develop approaches for generating the required data; and

4. Apply these approaches in field studies to develop data on exposures and the relevant exposure factors.

Currently, exposure measurement studies are addressing two critical areas: children's aggregate exposures to pesticides and inhalation exposure to PM, PM constituents, and air toxics. Outputs of current studies will be described. Details of new studies in both areas will also be provided.

This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.


PRESENTATION Modeling Inhalation and Multimedia Multipathway Human Exposures to Environmental Pollutants 06/24/2003
Ozkaynak, A H. Modeling Inhalation and Multimedia Multipathway Human Exposures to Environmental Pollutants. Presented at The American Chemistry Council Long Range Research Initiative Annual Science Meeting, Herndon, VA, June 24-25, 2003.
Abstract: Estimation of exposures of children and adults to air toxics or multimedia pollutants require careful consideration of sources and concentrations of pollutants that may be present in different media, as well as various routes and pathways of exposures associated with age-specific activities of individuals. In recent years, a number of probabilistic inhalation or aggregate exposure models have been developed by various researchers for estimating exposures to selected chemicals from different routes and pathways. Cumulative exposure models, dealing with aggregate exposures from more than one chemical are, however, still mostly in the developmental stage. The EPA's Office of Research and Development (ORD), National Exposure Research Laboratory (NERL) has developed a probabilistic model (Stochastic Human Exposure and Dose Simulation Model, or SHEDS) that predicts the variability in the distribution of personal exposures and doses within a population cohort, as well as the uncertainty in the model estimates. The SHEDS model framework has initially been developed to study general population exposures to fine Particulate Matter (PM2.5) and children's exposure to pesticides. At the present, the SHEDS-Pesticides models include the inhalation and dietary ingestion routes in addition to dermal contact and non-dietary ingestion. SHEDS-PM (i.e., particulate matter and its associated constituents) and SHEDS-ATOX (i.e., air toxics) models, which are currently either being refined or developed, use the same modeling approach as the SHEDS-Pesticides model, however the primary focus is on inhalation exposure and dose. A user-friendly interface has been developed for the aggregate SHEDS-Pesticides and SHEDS-PM model with both exposure researchers and regulators in mind as potential users. SHEDS and other aggregate or cumulative pesticide exposure models still need rigorous evaluation and independent verification against carefully designed field studies. All of the exposure models suffer from limitations of available input information on critical exposure factors, especially for children. In general, models need to identify which inputs or parameters are of special concern for future model refinements or further sensitivity analysis. This information will in turn assist the design of future field exposure and biomonitoring studies that will be used in refining or evaluating the current exposure models. In order to develop more robust models with more complete input data, repeated or longitudinal concentration or residue measurements, time-activity data, and frequency of chemical-specific product use information in homes, day care centers/schools, commuting and other important microenvironments are also needed. Finally, the form of model outputs that are most useful to regulatory and scientific agencies and to the public also needs to be identified.
This work has been wholly funded by the United States Environmental Protection. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Hierarchial Bayesian Calibration: An Application to Airborne Particulate Matter Monitoring Data 06/03/2003
McBride, S., M. Clyde, AND R W. Williams. Hierarchial Bayesian Calibration: An Application to Airborne Particulate Matter Monitoring Data. Presented at American Association for Aerosol Research, Boulder, CO, June 1-6, 2003.
Abstract: In studies of the relationship between airborne fine particulate matter (PM2.5) and health, researchers frequently use monitoring data with the most extensive temporal coverage. Such data may come from a monitor that is not a federal reference monitor (FRM), a monitor that is designed and calibrated to meet federal National Ambient Air Quality Standards (NAAQS). In the recent past for the Phoenix area, measurements from a FRM have been available less frequently and have had levels of accuracy and bias that differed from a collocated equivalent (non-FRM) monitor. Using the soil constituent of PM2.5 as an illustration, we describe a Bayesian hierarchical model that combines information from collocated FRM and equivalent monitors to produce a temporally resolved posterior estimate of the complete concentration time series. Mean concentrations were modeled using a regression structure that reflected the influence of meteorology. To account for bias in monitors relative to each other, the mean at the equivalent monitor was represented by the product of an unknown bias parameter times the unknown mean concentration at the FRM monitor. Estimation of the bias parameter involved inference about the ratio of normal means as in the well-known Fieller-Creasy problem. We developed a multi-parameter, non-informative "reference prior" (Bernardo, 1979) for the hierarchical model that permitted simultaneous inference about the underlying mean concentrations and the bias parameter. By using a Bayesian calibration approach, the posterior distribution of unknown pollutant concentrations conditional on the measured data and model parameters could be estimated at all time points including those having missing data. Results characterized mean posterior concentrations and 95% credible intervals at the FRM and equivalent monitors, with the equivalent monitor showing larger concentrations than the FRM prior to an inlet upgrade and smaller concentrations after the inlet upgrade. The use of differing variances for each measurement within and between monitors ensured that large observations at either monitor did not have an undue influence on estimated posterior mean concentrations. For this case study, we describe the implications of using monitoring data from the biased equivalent monitor in models relating PM2.5 and health. Combining monitoring data from multiple monitors is of particular relevance to exposure-epidemiology panel studies, where multiple monitors have often been co-located and may have had missing data. Through hierarchical models that combine information from co-located monitors, we show that uncertainty in concentration measurements can be built into models of human exposure and health.
This work has been partially funded by the U.S. Environmental Protection Agency's Office of Research and Development under contracts 3D-5925-WATX (Sandra McBride), 68D-99-012 (RTI International), and cooperative agreement CR-828186-01-0 (Shaw University). It has been subjected to Agency review and approved for publication.

PRESENTATION Research in EPA's National Exposure Research Laboratory (NERL) to Reduce Uncertainties in Children's Exposure/Risk Assessments 05/13/2003
Tulve, N S. Research in EPA's National Exposure Research Laboratory (NERL) to Reduce Uncertainties in Children's Exposure/Risk Assessments. Presented at NCEA Seminar Series, Washington, DC, May 13, 2003.
Abstract: The US EPA has pledged to increase its efforts to provide a safe and healthy environment for children by ensuring that all EPA regulations, standards, policies, and risk assessments take into account special childhood vulnerabilities to environmental toxicants. To help explain the challenges and research needs associated with children's exposure to environmental pollutants, EPA/ORD developed a research strategy to improve risk assessments for children. Similarly, in support of the Food Quality Protection Act (FQPA) of 1996, EPA is required to upgrade the risk assessment procedures for setting pesticide residue tolerances in food by considering the potential susceptibility of infants and children to both aggregate and cumulative exposures to pesticides. Currently, the data on children's exposures and exposure factors are limited and generally not adequate to assess residential exposures to consumer products and environmental contaminants. Several areas of research need to be addressed to improve the quality and quantity of data available for exposure assessments for children.
The Children's Exposure Research Program at the EPA/NERL is designed to meet several research needs that have been identified in initial assessments of the adequacy of the data for estimating children's exposure to pesticides and environmental toxicants. The goal of the EPA/NERL measurement research program in support of FQPA is to develop and evaluate approaches and methods for assessing children's aggregate exposure to pesticides and to conduct studies to collect data required to reduce reliance on default assumptions in development of quantitative exposure assessments. Based on an initial assessment of critical exposure pathways and factors, researchers in the NERL identified four priority research areas where there are critical data gaps. These areas include: (1) pesticide use patterns, (2) spatial and temporal distribution of pesticides in residences and child care centers, (3) factors influencing dermal and indirect ingestion exposures, and, (4) dietary exposure. Targeted studies were designed and implemented to address these research needs. They included laboratory studies, small pilot field studies, analysis of available data sets, and two large studies in which EPA/NERL collaborated with other Federal agencies.

Research results from these studies were used to develop a Draft Protocol for Measuring Children's Non-Occupational Exposure to Pesticides by all Relevant Pathways and as input to the design of a large children's exposure measurements study. The Draft Protocol was developed to provide guidance for generating data that can be used to improve exposure assessments for young children. It fills a critical need for standardization of the approaches and methods for collecting exposure concentration and exposure factor data.

EPA/NERL has designed a two-year longitudinal study in which measurements will be made to estimate the aggregate exposures for children 3 months to 3 years of age to current-use indoor residential pesticides (primarily pyrethroids). The study will be conducted in the greater Jacksonville, FL area. Up to 100 young children will be enrolled into the study in two cohorts: (1) infants recruited into the study soon after birth, and, (2) young children recruited into the study at approximately 12 months of age. The overall goals of the field study are the following: (1) collect data that can be used for evaluation and refinement of the Draft Protocol, (2) improve our understanding of the important pathways of exposure for very young children, and, (3) evaluate the impact of developmental age and children's activities on indoor residential pesticide exposure. In addition, EPA/NERL has also written a proposal to the American Chemistry Council to add three additional classes of compounds: selected phthalates, brominated flame retardants, and perfluorinated compounds. This proposal is currently pending. The study design was externally peer-reviewed in August, 2002. The field measurement data collection will begin in Fall 2003, pending successful OMB submission.

This seminar will highlight ORD/NERL's research efforts to date to develop the Draft Protocol and the design for the longitudinal field measurement study to be conducted in Jacksonville, FL.

This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer-reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Applying An Innovative Model (Sheds: Stochastic Human Exposure and Dose Simulation Model) to Assess Children's Exposures to Pesticides 05/06/2003
Zartarian, V, J Xue, AND A H. Ozkaynak. Applying An Innovative Model (Sheds: Stochastic Human Exposure and Dose Simulation Model) to Assess Children's Exposures to Pesticides. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION The Importance of Obtaining Information on the Specific Content of Tissue Enzymes Metabolizing Organophosphorus Pesticides, Prior to Determine Vmax, Km Values for Use in PBPK Models 05/06/2003
Knaak, J. B., F W. Power, J N. Blancato, AND C C. Dary. The Importance of Obtaining Information on the Specific Content of Tissue Enzymes Metabolizing Organophosphorus Pesticides, Prior to Determine Vmax, Km Values for Use in PBPK Models. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Physiological pharmacokinetic/pharmacodynamic models require Vmax, Km values for the metabolism of OPs by tissue enzymes. Current literature values cannot be easily used in OP PBPK models (i.e., parathion and chlorpyrifos) because standard methodologies were not used in their determination. In practically all cases, the investigators failed to determine the specific content of the enzymes of interest in tissues or tissue fractions (PON1 and P450 isozymes) under investigation prior to use, by either spectral or immunochemical methods. The concentration of plasma PON1 (paraoxonase) may vary as much as 60 to 600 ug/ml making it difficult to select proper enzyme-substrate concentrations for the determination of Vmax, Km. The same problem exists measuring P-450 activity using microsomal protein, when the specific content (pmoles of P-450, total or individual CYPs) in the microsomes is unknown. Rendic and Guengerich recently recommended individual CYPs (i.e, 1A2, 2B6, 2D6 and 3A4) be used to obtain Vmax, Km values in place of human whole liver microsomes. Mathematical equations are available for expressing individual CYP data (specific content and activity) in terms of native liver microsomes and using the data in PBPK models. Methods will be presented for obtaining Vmax, Km values for parathion and chlorpyrifos based on the specific content of PON1 and P-450 in plasma and liver microsomes.

PRESENTATION Better Exposure-Dose Models for Pesticides 05/06/2003
Knaak, J. B., R TORNERO-VELEZ, F W. Power, J N. Blancato, AND C C. Dary. Better Exposure-Dose Models for Pesticides. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Environmental Monitoring and Modeling Associated With National Emergencies Experiences Gained from the World Trade Center 05/06/2003
Vette, A F., S C. Hern, J N. Blancato, A H. Huber, H.D A. Lindquist, AND M N. Lorber. Environmental Monitoring and Modeling Associated With National Emergencies Experiences Gained from the World Trade Center. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Etv Homeland Security Evaluation of Cyanide Detectors 05/06/2003
Fuerst, R G., R. James, H. Latham, AND K. Riggs. Etv Homeland Security Evaluation of Cyanide Detectors. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: EPA's Environmental Technology Verification (ETV) Program was established in 1995 to objectively verify the performance of technologies that measure / monitor the quality of our environment, both for background or at suspected contamination site. The ETV program has established six centers to verify a wide variety of environmental technologies. This technology verification program is now incorporated into EPA's Homeland Security efforts. One of the Centers, the Advanced Monitoring Systems (AMS) Center, recently conducted an analysis of commercially available devices to detect cyanide in water.
EPA and AMS Center staff recently met with interested Stakeholders to identify possible detection devices that could be used to assist with protection of the nations drinking water systems, whether raw or finished water. At the recommendation of the Stakeholder community, the Center inquired amongst the vender community as to whether any vender with a cyanide in water detector wished to have the performance of their technology verified through the ETV process. The toxic dose for drinking water is 250 mg CN/l which is too large of a logistical amount for purposefully reservoir or large water body contamination, but could be a threat for distribution points in or to a public building. This pollutant and this scenario was shown as a possible threat, when authorities in Rome, Italy in February 2002, found a map pinpointing the location of water pipes to an American Embassy. Five venders with six technologies have participated in a cyanide in water detection test. The developed verification Test Plan will also be turned into a test Protocol for later testing of similar technologies. Parameters assessed were such things as: accuracy, precision, linearity, detection limit, interferences, operator bias, inter-unit reproducibility and rates of false positives and false negatives. Using this information, the state or local utility operator, using verified technologies, can make a rapid assessment, based on credible data, of any suspected change in the drinking water quality at their plant. This Poster will describe the significance of that testing.

PRESENTATION Environmental Monitoring and Modeling Associated With National Emergencies Experiences Gained from the World Trade Center Disaster 05/06/2003
Vette, A F., S C. Hern, M. Kantz, J N. Blancato, A H. Huber, H.D A. Lindquist, AND M N. Lorber. Environmental Monitoring and Modeling Associated With National Emergencies Experiences Gained from the World Trade Center Disaster. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: A workshop was held in Research Triangle Park, NC on November 18-19, 2002 to discuss scientific issues associated with measuring, modeling, and assessing exposure and risk to air containing contaminants generated as a result of national emergencies and disasters. Participants were invited from throughout the U.S. EPA and other Federal Agencies to share the experiences learned during the response to the collapse and recovery efforts at the World Trade Center. More than 50 participants from across EPA (including ORD, OSWER, Region 2, OERR, OPP, OPPTS, OAQPS, and OIG), and from CDC, NIOSH, DOE, and academia attended. The purpose of the workshop was to discuss how the Office of Research and Development can apply its expertise in human exposure and risk assessment in an emergency response situation to protect human health, and make our lessons learned available to others. Issues that were discussed at the workshop included: (1) identifying the types of airborne hazards likely to emerge during national emergencies and the appropriate measurement techniques for applicable risk assessment benchmark levels, (2) available models that could initially be used for dispersion estimates to assist in establishing a monitoring plan and those that can then be applied to understand and predict human exposures as well as spatial and temporal dynamics of pollutant transport, (3) approaches for risk assessment and risk communications, and (4) the challenges associated with integrating research into an emergency response. The major recommendations from the workshop along with a summary of the presentations and discussions will be synthesized into a report. This report will be of use to the U.S. EPA and other agencies as they respond to future emergencies and disasters.

PRESENTATION Are Cars or Trees More Important to Particulate Matter Air Polution? What Radiocarbon Measurements Have to Say 05/06/2003
Lewis, C W., G. A. Klouda, AND W. D. Ellenson. Are Cars or Trees More Important to Particulate Matter Air Polution? What Radiocarbon Measurements Have to Say. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Air pollution in the form of particulate matter (PM) originates from both human activities and "natural" phenomena. Setting and achieving National Ambient Air Quality Standards (NAAQS) for PM has to take into account the latter since they are in general less controllable than the former. One of the elusive contributors to "natural" PM, particularly during summertime, is biogenic secondary organic aerosol (SOA), which results in the formation of PM from atmospheric gas-to-particle conversion of volatile organic compounds (VOC) emitted by vegetation. Theoretical estimates of the importance of biogenic SOA as a component of summertime PM differ greatly, ranging from negligible to dominant, because of uncertainties in both the conversion mechanism, and the amount and characteristics of biogenic VOC emissions. However, quite direct experimental estimates can be obtained by measuring the amount of the naturally-occurring radioactive isotope 14C (radiocarbon) in a PM sample. The method depends on the tiny but nearly constant fraction of 14C relative to ordinary carbon (12C) in all living and recently living material, and its absence in fossil fuels. Beginning a few years ago a series of fine PM (PM-2.5) summertime samples are being collected at various sites in the Southeastern U.S. for subsequent radiocarbon measurement, including collaboration with the State of Texas in Houston and the State of Florida in Tampa. Initial results indicate a surprisingly large carbonaceous biogenic fraction -- approximately one half -- presumably in large part from SOA. If the initial results are representative this finding has serious implications for PM-2.5 control and standard setting.

PRESENTATION Environmental Technology Verification, Homeland Security, and Cyanide Detectors 05/06/2003
Fuerst, R G., R. James, H. Latham, AND K. Riggs. Environmental Technology Verification, Homeland Security, and Cyanide Detectors. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Assessing Children's Exposures to Pesticides: An Important Application of the Stochastic Human Exposure and Dose Simulation Model (Sheds) 05/06/2003
Zartarian, V, J Xue, AND A H. Ozkaynak. Assessing Children's Exposures to Pesticides: An Important Application of the Stochastic Human Exposure and Dose Simulation Model (Sheds). Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Accurately quantifying human exposures and doses of various populations to environmental pollutants is critical for the Agency to assess and manage human health risks. For example, the Food Quality Protection Act of 1996 (FQPA) requires EPA to consider aggregate human exposure to a pesticide, especially for infants and children, when making regulatory decisions on that pesticide's usage. Pesticides and metals are two examples of pollutants that can be present in multiple environmental media (air, water, soil, house dust, food, surface residues) and that can contact a human via various routes and pathways. These include dietary ingestion, inhalation, dermal contact, and non-dietary ingestion from hand- or object-to-mouth activities.
The FQPA was the impetus for the development of computer models that simulate children's pesticide exposures and doses for various exposure scenarios. Since 1998 the EPA's Office of Research and Development (ORD), National Exposure Research Laboratory (NERL) has been developing a physically-based probabilistic model called the Stochastic Human Exposure and Dose Simulation Model (SHEDS) for pesticides. SHEDS can answer questions such as:

- What is the population distribution exposure and dose, accounting for variability in activity patterns, environmental concentrations contacted, and other factors?
- What is the uncertainty the model estimates?
- What is the time profile of exposures for individuals in a population?
- Which sources, media, pathways, and factors contribute the most?
- Which additional measurements should be collected to minimize uncertainty?
- How can we most effectively reduce exposure?
- Do modeled estimates compare well against field measurements?

This work involves collaborations between ORD and EPA's Office of Pesticide Programs (OPP), with ORD/NERL's University Partners for modeling, and within ORD. The SHEDS research for CCA is being used as part of OPP's public health risk assessment. We are applying SHEDS to three case studies for children: (1) aggregate chlorpyrifos exposures from indoor crack and crevice applications, lawn treatments, and garden treatments [planned for Fiscal Year 2004 timeframe]; (2) arsenic and chromium exposures from chromated copper arsenate (CCA)-treated wood on decks and playsets [this application is currently being done for OPP's Antimicrobials Division's health risk assessment which is scheduled for presentation to OPP's Federal Insecticide, Fungicide, Rodenticide Act (FIFRA) Science Advisory Panel (SAP) in December 2003]; and (3) pyrethroid pesticide exposures from indoor crack and crevice, broadcast, and fogger treatments; lawn and garden treatments; and contact with treated pets [planned for Fiscal Year 2003/2004 time frame]. To conduct these case studies, a user-friendly model with graphical user interface continues to be developed with exposure researchers and regulators in mind as potential users.

The SHEDS chlorpyrifos research demonstrates the model framework and evaluation of the model against real-world measurements. The SHEDS pyrethroids research is intended to help OPP in their FQPA decision for pyrethroids.

PRESENTATION Cars or Trees: Which Contribute More to Particulate Matter Air Pollution? 05/06/2003
Lewis, C W., G. A. Klouda, AND W. D. Ellenson. Cars or Trees: Which Contribute More to Particulate Matter Air Pollution? Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Developing a Better Understanding of Real-World Automobile Emissions 05/06/2003
Gabele, P A. Developing a Better Understanding of Real-World Automobile Emissions. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Emission inventories are needed by EPA for air dispersion modeling, regional strategy development, regulation setting, air toxics risk assessment, and trend tracking. Therefore, it is extremely important that inventories be accurate and be updated frequently. The development and update of emission inventories can be conducted from top/down using receptor models, or from bottom/up using emission factor models. Both of these approaches must address mobile source emissions which are a major source of air pollution. In the top/down approach, source profiles from mobile source emissions are needed; while in the bottom/up approach, mobile source emission factors are needed. In order to obtain realistic data, it is important that the source profile and emission factor data be obtained under realistic conditions. Vehicles must be tested under conditions that mirror their operation in the real world because operating conditions affect the character (source profile) and quantity (emission factor) of the emission. Operating conditions include such important variables as fuel (e.g., reformulated versus baseline gasoline), ambient temperature, driving mode (e.g., transient versus steady-state), and malfunction. The effect of malfunction on the quantity and character of emissions is not underestimated because most of the emissions come from the small minority of vehicles that are malfunctioning. Malfunctioning vehicles are found more often in the real world than in the laboratory.
Many of the studies conducted with the transportable dynamometer are sponsored in part by other agencies, such as the Department of Energy, Department of Transportation and California Air Resources Board. These studies investigated the mobile source particulate matter inventory using source receptor techniques. Air toxic emission factor data were provided for many of the vehicles tested in the studies. Other studies in Mexico and Texas have provided these two entities with emission factor data from vehicles operating in their areas. These data have been used for dispersion modeling and for the development of a regional strategy for addressing air quality issues. The dynamometer has also been shipped to locations to examine emissions from cars under unusual conditions. For example, the effect of extremely low-temperature operation with oxygenated fuels was examined in Fairbanks, Alaska.

Use of the transportable dynamometer is anticipated in future source apportionment studies. In particular, its use to obtain source profiles for gasoline vehicles operating within specific regions is envisioned. These data can be used in regional source receptor models to clarify and update existing emission inventories.


PRESENTATION A Community-Based Children's Pesticide Exposure Measurement Study in Jacksonville, Florida 05/06/2003
Tulve, N S., R C. Fortmann, D A. Whitaker, H. Brown, A. Hilliard, AND L. P. Naeher. A Community-Based Children's Pesticide Exposure Measurement Study in Jacksonville, Florida. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Children's exposures to pesticides and chemicals in consumer products may be different, and in some cases, higher than exposures for adults. The U.S. Environmental Protection Agency (EPA) is conducting research to gain a better understanding of children's exposures and the factors that affect exposures to chemicals in homes, child care centers, other indoor environments, and outdoor environments where children may spend their time. Recently, the EPA had the opportunity to collaborate with the Duval County, Florida Health Department and the Centers for Disease Control and Prevention (CDC) on a measurement study to characterize young children's potential exposures to pesticides in residential environments in Jacksonville, FL.
The Duval County Health Department (DCHD) initiated this community-based study and solicited participation from the CDC for measurements of pesticide metabolites in urine and the EPA for assistance in characterizing pesticide residues in the homes of study participants. Working with CDC and EPA, the DCHD project evolved into a three-tiered study that examined potential exposures of young children (4 to 6 years old) to a large number of organophosphate pesticides (primarily used outdoors) and pyrethroid pesticides (currently used extensively for indoor pest control). The three-tiered study design consisted of the following:

Tier 1: Recruitment of 200 children from County health clinics, completion of a questionnaire, and collection of a urine sample from each participating child;

Tier 2: Collection of environmental screening samples at the homes of approximately 25% of the children who participated in tier 1;

Tier 3: A detailed aggregate exposure assessment for nine of the homes sampled in tier 2.
DCHD staff collected samples in tiers 1 and 2. EPA staff performed the aggregate exposure assessment at the nine homes in tier 3.

Results of analyses from urine samples will be used to evaluate the children's exposure to the target pesticides in this community and for comparison to data from other measurement studies (e.g. NHANES). Data from the DCHD tier 2 measurements will be used to evaluate the screening method as a tool to identify homes with the potential for elevated exposures or pesticide poisoning. The aggregate exposure assessment data, in combination with data from other EPA studies, will be used reduce reliance on default parameters in exposure and risk assessments for pesticides. The project represents a highly successful partnership by a local government agency and two Federal Agencies to address a number of research objectives and to improve our understanding of children's exposures to pesticides in the home.

PRESENTATION Developing Tools to Assess Exposure in Minority and Low Income Communities 05/06/2003
Leovic, K W., D A. Vallero, AND Y. B. Anderson. Developing Tools to Assess Exposure in Minority and Low Income Communities. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Children's Pesticide Exposure: A Community-Based Measurement Study in Jacksonville, Florida 05/06/2003
Tulve, N S., R C. Fortmann, D A. Whitaker, L S. Sheldon, H. Brown, A. Hilliard, AND L. P. Naeher. Children's Pesticide Exposure: A Community-Based Measurement Study in Jacksonville, Florida. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Arsenic in Water Used for Drinking An Environmental Technology Verification 05/06/2003
Fuerst, R G., P. White, H. Latham, AND K. Riggs. Arsenic in Water Used for Drinking An Environmental Technology Verification. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: In October 2001, the U.S. Environmental Protection Agency (EPA) announced a new federal standard for concentrations of arsenic found in drinking water. The new standard was to be 10 parts-per-million (ppm). This new standard will be required by the Safe Drinking Water Act in January 2006. The previous maximum acceptable arsenic standard for drinking water was 50 ppm. Nearly 97 percent of the water systems of the U.S. affected by this new rule are small systems. The World Health Organization (WHO) is seeking reliable, easy to operate, arsenic detection systems for use in countries such as Bangladesh and India. Many people, especially located in these countries are exposed to high levels of arsenic found in the underlying sediment of their drinking water systems. They draw their drinking water from small local and personal wells.
To meet this challenge and assist the WHO and others interested in arsenic as a possible contaminant in their drinking water obtained from above or below ground sources, the Environmental Technology Verification's (ETV) Advanced Monitoring Systems (AMS) Center performance verified four test kits that can be used to measure the concentrations of arsenic in water. A by product of results of this verification test is that ETV can assist venders in the marketability of their arsenic detectors. The Verification Reports are published on the ETV Internet Website at for public scrutiny. The purpose of this verification test was to evaluate the performance of these test kits to measure total arsenic in water under real-world conditions. Over a 19-day period water samples were collected and tested from freshwater, and drinking water sources. Freshwater samples were collected from a river and two different creeks. The drinking water samples were collected from municipal, well, and treated well water sources. Two sets of laboratory performance test samples were prepared using tap water as a source: one set determined kit response to various concentrations of arsenic, while another set assessed the effects of matrix interferences on performance. Interferences tested were iron, sodium chloride and sulfide at low and high concentration levels. The test kit response was determined at arsenic concentrations ranging from 1 to 100 ppb. Performance parameters reported include: accuracy, precision, linearity, method detection limit, matrix interferences, operator bias (skill level needed), and rate of false positives/false negatives to a 10-ppb decision level. For comparison purposes, all samples, performance and real-world, were analyzed for arsenic using a laboratory reference method. The reference arsenic analysis was performed using a Perkin Elmer Sciex Elam 6000 ICPMS according to EPA Method 200.8, Revision 5.5.

PRESENTATION Assessing Exposures to Environmental Contaminants in Minority and Low Income Communities 05/06/2003
Leovic, K W., D A. Vallero, AND Y. B. Anderson. Assessing Exposures to Environmental Contaminants in Minority and Low Income Communities. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Research has shown that minority and low income communities are often at greater risk of impact from environmental hazards. Many studies use surrogate measures of exposure for minority and low income populations due the lack of actual data on exposures in these communities. The objective of this project is to develop tools for assessing environmental exposures in environmental justice (EJ) communities. The project will also serve to develop the research infrastructure of the Environmental Sciences Program at North Carolina Central University (NCCU), a historically black university (HBU).
The project is being conducted collaboratively between NCCU and the EPA under a cooperative agreement, and an EPA scientist is currently working at NCCU under an Intergovernmental Personnel Agreement. To provide community interaction and help guide the project, NCCU has established an Advisory Board. Representatives on the Advisory Board include state and community groups in NC (e.g., Department of the Environment & Natural Resources, Environmental Justice Network, Department of Health), NCCU, the private sector, and the federal government (EPA and the National Institute of Environmental Health Sciences).

This study will directly impact the community to be studied by providing community-specific exposure data. Because the study will be conducted in an EJ community, it will also begin to address the concept of "cumulative exposure." The community, by definition is an EJ community and, thus, may also be exposed to additional stressors that influence the community's cumulative exposure. In the long-term, this information will be relevant to other similar EJ communities by providing experiences and lessons learned on the best approaches for conducting an exposure study in minority/low income communities. The project is also providing training for NCCU students through the development of faculty expertise in exposure studies and laboratory facilities.

PRESENTATION Bioavailability of Metals in Environmental Media 05/06/2003
Bradham, K. Bioavailability of Metals in Environmental Media. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Heavy metal and organic chemical contamination of soils is a worldwide problem posing a risk to humans and more directly, soil organisms. Due to widespread metal contamination, it is necessary to characterize soils suspected of metal contamination and determine if the metal levels in these soils pose a hazard. Metal toxicity is often not directly related to the total concentration of metals present due to a number of modifying factors that depend, in part, on soil chemical properties. Soil organic matter, pH, and clay content are soil chemical properties that influence metal toxicity and bioavailability. Bioavailability is a measure of the potential for entry of a metal into biological receptors. It is specific to the receptor, the route of entry, duration of exposure, and the exposure matrix. Risk is directly related to metal bioavailability, which depends upon metal concentration, the geochemical forms of metal, the species of organism exposed, physical and chemical characteristics of the exposure environment, and the exposure duration. In order to understand metal bioavailability in soils, chemical and biological techniques are needed to measure the portion of metal that is theoretically bioavailable to humans and soil organisms. These can range from direct measures of bioavailability such as concentrations in soil organisms to indirect measures such as chemical extractions. Current routine practices of investigating the nature and extent of contamination at metal-contaminated sites involve determining total metal content in soils. The quantity of metal to be used as exposure concentrations in the risk calculation is an assumed percentage of the total content, which may be bioavailable. Often, very high percentages (near 100%) of total metals are assumed bioavailable. While this assumption is conservative in terms of being protective of human health and the environment, it may not be a reasonable estimate of site conditions because the actual bioavailability of metals has not been assessed. The resulting risk may overestimate the true risk of exposure to site media. Overestimation of risk may result in lengthy and costly site remediation that may not be warranted.


PRESENTATION The Association of Exposure to Particulate Matter and Related Air Pollutants With Specific Health Effects in Healthy Highway Patrol Officers 05/06/2003
Williams, R W., M. Riediker, L S. Sheldon, R B. Devlin, T. Griggs, P A. Bromberg, L Neas, M. Herbst, AND W. Cascio. The Association of Exposure to Particulate Matter and Related Air Pollutants With Specific Health Effects in Healthy Highway Patrol Officers. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Estimated exposures to ambient respirable particulate matter (PM) and related co-pollutants have been statistically associated with mortality and morbidity in epidemiological studies conducted throughout the world. Although some subpopulations (e.g., asthmatics; elderly, pulmonary-or cardiovascular-impaired) appear to be more susceptible to adverse health effects from these exposures, no specific causal agent or precise mechanisms underlying mortality or morbidity have been clearly identified. In an attempt to address this area of uncertainty, the National Exposure Research Laboratory (NERL) and the National Health and Environmental Effects Research Laboratory (NHEERL) successfully collaborated with the University of North Carolina at Chapel Hill and the North Carolina Highway Patrol to investigate the potential health effects of mobile source-related exposures on 9 healthy, non-smoking, North Carolina highway patrol officers. Troopers were monitored over a six week period to determine the association between specific mobile-source related air pollutants and changes in select health effect indicators. Troopers are potentially exposed to high levels of mobile source-related air pollutants because they spend a majority of each day traveling in cars on urban roads. Data has provided the first indication that in-vehicle related PM exposures might be associated with discrete changes in cardiovascular, immunological and other physiological measures in healthy adults. These findings may provide insight as to specific air pollutants (and sources) responsible for adverse health effects observed in sensitive subpopulations. This collaboration was shown to be beneficial and necessary, in that it utilized specific resources and talents of each collaborating organization's staff that otherwise would not have permitted the study to have been performed by a single organization.

PRESENTATION Toxicity-Based Chemical Agent Detection Systems: Continuous Monitor and Exposure History 05/06/2003
Rogers, K R. AND G L. Robertson. Toxicity-Based Chemical Agent Detection Systems: Continuous Monitor and Exposure History. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: This project will develop and characterize chemical agent detection systems that will provide broad toxicological screening information to first responders and building decontamination personnel. The primary goal for this technology is to detect the presence of airborne chemical agents that will damage metabolic or neurological function. The anticipated applications with respect to building decontamination will be first, to provide a time integrated record of chemical toxins that have been present in the air over a specified time period; and second, to provide a short term screening system to determine the current toxicological status of the local building environment. One of the unique features of this technology is that the proposed techniques will be used to characterize a broad range of compounds and agent simulants that are toxic but not expected to be detected by currently available chemical sensor technologies. The ability to detect toxic chemicals on the basis of their potential biological / biochemical function is expected to provide the basis of a rapid response chemical hazard detection system. The proposed sampling technology will also provide a time-integrated chemical exposure record for numerous locations throughout the building. The following subtasks will outline critical research for the development and characterization of this toxicological screening system. Continuous and time-integrated sampling of indoor air will be accomplished using semipermeable membrane devices (SPMD) consisting of polyethylene tubing containing a thin film of high molecular weight neutral lipid such as triolein. The accumulation of semivolatile organics through the approximately 10 Angstrom pores and into the organic phase appears to be similar to transport of organic vapors through biomembranes during respiration. SPMD sampling devices will be interfaced to two types of biochemical detection systems. These will include an enzyme system for detection of organophosphate insecticides and the "nerve agent" class of chemical warfare agents; and a general toxicity assay based on luminescent bacteria for the detection of metabolic inhibitors and membrane disrupting toxins. Studies will be conducted to compare the proposed toxicity screening system to an Ion Mobility Spectroscopy (IMS)-based technology that has been validated through the soldier biological chemical command (SBCCOM).

PRESENTATION Bay Regional Atmospheric Chemistry Experiment (Brace) 05/06/2003
Landis, M S. Bay Regional Atmospheric Chemistry Experiment (Brace). Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Bay Region Atmospheric Chemistry Experiment (Brace) 05/06/2003
Landis, M S. Bay Region Atmospheric Chemistry Experiment (Brace). Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: The Tampa Bay Estuary Program (TBEP) was formed in 1991 to assist the community in developing a comprehensive plan to restore and protect Tampa Bay. The ecological indicator of the health of the Bay is the coverage of seagrasses, historically in decline, which are important to the Bay's aquatic habitat and food web. Seagrass decline is linked to excess of plant-stimulating forms of nitrogen to the bay, promoting algae growth, which shades out light needed to sustain seagrasses. One element of the TBEP is a private-local-state, multi-agency Nitrogen Management Consortium that seeks to limit nitrogen loading to the Bay to the 1992-1994 average. Present estimates suggest atmospheric deposition comprises ~ 30% of the nitrogen budget of the Bay. This estimate is based, however, on limited ambient monitoring data and simple models.
In BRACE USEPA NERL will join with Florida DEP and TBEP to increase the intensity, sophistication and spatial scope of monitoring and modeling and provide better information on air quality in the Tampa Bay area. The result will be improved estimates of the effects of local and regional emissions of oxides of nitrogen (NOx) on the Bay and the benefits to be gained from implementation of emissions reduction strategies. The two primary objectives of BRACE are to (i) provide TBEP with robust estimates of deposition of biologically active forms of nitrogen to Tampa Bay and its watershed and (ii) assess the Tampa Bay air quality before and after the TECO Gannon Station re-powering from coal to natural gas. EPA NERL is contributing to BRACE by participating in atmospheric monitoring and modeling activities. Specifically NERL will conduct source apportionment modeling to identify the sources of observed NOx and PM2.5 and run a state-of-the-art model to evaluate the formation of ozone and secondary aerosols.


PRESENTATION Health and Exposure Research for the Agricultural Community: the Agricultural Health Study 05/06/2003
Thomas, K W., M. Alavanaja, D. P. Sandler, C. Hines, J. Pierce, AND C. Lynch. Health and Exposure Research for the Agricultural Community: the Agricultural Health Study. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: The Agricultural Health Study (AHS) is a collaborative effort between the National Cancer Institute, the National Institute of Environmental Health Sciences, the U.S. Environmental Protection Agency, and the National Institute for Occupational Safety and Health. The AHS is the most comprehensive prospective epidemiological study developed to examine agricultural exposures and health in the agricultural community. Beginning in 1994, information about pesticide use, work practices, and health has been collected from over 89,000 pesticide applicators and spouses in Iowa and North Carolina.
Scientists have the opportunity and responsibility to communicate important research findings to the communities they study. A goal of the Agricultural Health Study is to provide research results that can be used to identify factors that promote good health and ways that members of the agricultural community can more effectively protect themselves against possible risks. A multi-faceted approach has been developed in the AHS to disseminate research results. A website (www.aghealth.org) is updated quarterly; it explains the purpose of the study, the study status, and provides summaries of research findings. Recognizing that many people do not have internet access, we have developed state-level communications plans that involve the AHS Field Stations in North Carolina and Iowa in the dissemination of results. Several approaches are used to reach as wide an audience as possible, including direct mailings, distribution to and through the Cooperative Extension Services, farm publications, newsletters, distribution of flyers at agricultural meetings, and contact and interaction with agricultural organizations. Information is also made available to the public through the communications offices of the collaborating agencies. Results are published in the scientific literature and important scientific findings are summarized into lay-language fact sheets. Ongoing communication is planned as new health and exposure results become available from this prospective study. AHS researchers continue to collaborate with other experts and community stakeholders, including rural health providers and pesticide safety educators, who will be able to integrate study findings into educational materials and community programs.

PRESENTATION Ord's Transportable Dynamometer System 05/06/2003
Gabele, P A. Ord's Transportable Dynamometer System. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Ambient Air Monitoring at Ground Zero and Lower Manhattan Following the Collapse of the World Trade Center 05/06/2003
Vette, A F., R B. Zweidinger, R L. Seila, E C. Swartz, A H. Huber, R W. Williams, D. LaPosta, M. Kantz, J. Filippelli, K. Fradkin, L. Webb, L D. Grant, T G. Ellestad, AND D A. Vallero. Ambient Air Monitoring at Ground Zero and Lower Manhattan Following the Collapse of the World Trade Center. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: The U.S. EPA National Exposure Research Laboratory (NERL) collaborated with EPA's Regional offices to establish a monitoring network to characterize ambient air concentrations of particulate matter (PM) and air toxics in lower Manhattan following the collapse of the World Trade Center (WTC). These data have been used by the National Center for Exposure Assessment (NCEA) to assess the public's exposure and their risk associated with such exposures. Working closely with personnel from Region 2 in Edison, NJ and New York, NY, we identified several possible monitoring locations and installed air monitoring equipment around the WTC complex (Ground Zero) and the surrounding area. Monitoring began on September 21, 2001 at three sites within 100-200 m of Ground Zero with additional monitoring sites located about 500-1000 m from Ground Zero and continued until May 15, 2002. Integrated (24-hour and 72-hour) PM samples and continuous measurements of PM concentrations were taken at these sites along with measurements of volatile organic compounds and other air toxics. In early October 2001, Region 2 and NERL developed an updated monitoring strategy that included locating additional air monitoring sites and meteorological measurements in the surrounding area to better understand the migration of pollutants from the WTC through lower Manhattan. The meteorological measurements were used to model the wind patterns in Manhattan, incorporating the landscape features produced by buildings. Samples were analyzed collaboratively by the NERL, Region 7 and Region 2. Results from the combined monitoring strategy indicate that concentrations of PM and air toxics pollutants were elevated and highly variable through late October, 2001, particularly at the sites close to Ground Zero. Beginning in November, 2001, concentrations of PM and air toxics decreased substantially and stabilized thereafter. Integrating the results from the PM and air toxics monitoring with the meteorological modeling proved to be critical in the risk assessment and evaluation performed by the NCEA.

PRESENTATION Computational Chemistry: An Emerging Technology for Solving Problems in Atmospheric Chemistry 05/06/2003
Kleindienst, T E., M Lewandowski, AND E O. Edney. Computational Chemistry: An Emerging Technology for Solving Problems in Atmospheric Chemistry. Presented at Science Forum 2003, Washington, DC, May 5-7, 2003.
Abstract: Over the past three decades, atmospheric chemistry has served as an important component in developing strategies for reducing ambient concentrations of air pollutants. Laboratory studies are carried out to investigate the key chemical reactions that determine the fates and lifetimes of air pollutants, with the resulting data used to develop air quality models for predicting their ambient concentrations. Carefully planned field studies are carried out to evaluate the air quality models. If the models are found to be reliable, they are used by EPA and the states for various regulatory activities to evaluate control strategies for meeting national air quality standards. To date, these models have been employed to evaluate strategies for ozone, air toxic compounds and particulate matter. While this methodology has led to significant improvements in air quality, the large amount of input data needed for the models and the cost and time required for laboratory studies has limited the number of modeling studies completed. However, over the past decade, rapid advances in computational chemistry have led to the development of software tools for predicting chemical properties such as activity coefficients, solubilities, vapor pressures and atmospheric lifetimes and fates of atmospherically relevant compounds. These tools have the potential for providing the agency with the chemical input data required for air quality models in a rapid and cost-effective manner.
A series of screening studies have been carried out to evaluate the reliability of computational chemistry-based predictions of thermodynamic and kinetic data of atmospherically relevant compounds. Studies conducted to date include the use of computational chemistry to predict (1) the atmospheric lifetimes of substitutes of ozone-depleting chlorofluorocarbons, (2) the atmospheric fate of toluene, a key component of automobile exhaust, (3) the atmospheric lifetime of mercury, and (4) the vapor pressures and activity coefficients of organic compounds in PM2.5. While additional studies are needed to fully evaluate this new tool, the results suggest that computational chemistry-based methods could play an important role in assessing control strategies for reducing ambient concentrations of air pollutants. Furthermore, even at this stage of development, there has been an integration of computational chemistry into research being carried out by NERL scientists as shown by the computational chemistry-based vapor pressures and activity coefficients of organic compounds serving as input data for the PM chemistry model to be used by OAQPS and in state implementation plans.

PRESENTATION Coarse PM Methods Evaluation Study 05/03/2003
Harmon, M K. AND T G. Ellestad. Coarse PM Methods Evaluation Study. Presented at Standing Air Monitoring Work Group (SAMWG), Baltimore, MD, May 2-3, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Preliminary Exposure Assessment Findings from the Tampa Asthmatic Children's Study 04/29/2003
Stevens, C, R W. Williams, F L. Chen, A F. Vette, R L. Seila, E. Amos, L S. Sheldon, C. Rodes, AND J. Thornburg. Preliminary Exposure Assessment Findings from the Tampa Asthmatic Children's Study. Presented at Tampa Environmental Protection Commission, Tampa, FL, April 29, 2003.
Abstract: The Tampa Asthmatic Children's Study (TACS) was a pilot study that focused on developing and evaluating air pollution exposure assessment methods and participant recruiting tools. The four-week study was performed in October and November, 2003. The study involved repeated daily personal, residential, and ambient air pollution measurements for a cohort of nine children. Measurements were taken to determine the microenvironmental concentrations of combustion-related products (CRP), particulate matter (PM), and some air toxics. A portable "lunch box" was developed that permitted air in close proximity to the young child (personal) to be continuously monitored. The lunch box was designed to fully contain all of the active and passive sampling devices needed for personal monitoring of each child in a safe and effective manner. The lunch box had to be lightweight, quiet, and portable so that it would be easy to move the box and keep it near their child at all times. Participating children were clinically diagnosed as being asthmatics, less than or equal to 5 years of age, and lived in single family dwellings with nonsmoking parents. They were recruited through a broad-based campaign consisting of public notices, physician and community contacts. The study involved 24-hour integrated PM2.5 and PM10 mass measurements over four consecutive days for each participant. Real-time measurement of PM2.5 mass concentrations were collected using the MIE-pDR nephelometer. These measures and the activities recorded in a daily dairy will be used to correlate the child's personal PM exposure with their activities and the microenvironments where they spend time. Concentrations of a number of criteria pollutants (CO, SO2, NO2, O3) were also measured. Data collection for the study has been completed and an initial data analysis has been performed. Mean daily personal, residential indoor, residential outdoor, and ambient PM2.5 mass concentrations were 12.5, 9.3, 11.3, and 12.7 µg/m3, respectively. Personal PM2.5 mass concentrations ranged from 6.1 to 26.1 µg/m3. Specific source events such as exposure to cooking aerosols, household cleaning events, riding in an automobile, and burning candles were determined to contribute to the children's total personal PM exposure. Personal and residential indoor concentrations of criteria pollutants were below the national ambient air quality standards for all participants.
This work has been funded wholly by the United States Environmental Protection Agency' s Office of Research and Development under contract # 68-D-99-012 to the Research Triangle Institute. It has been subjected to Agency review and approved for publication.


PRESENTATION Earth Day 2003: Learning from the East in the EPA: Eastern Philosophy Enriching Western Scientists 04/23/2003
Butler, L, A Pilant, D Mukerjee, E J. Furtaw Jr., A Zhao, W H. Engelmann, A de la Cruz, AND F Kawahara. Earth Day 2003: Learning from the East in the EPA: Eastern Philosophy Enriching Western Scientists. Presented at Earth Day, Las Vegas, NV, April 23, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Gasoline/Diesel PM Split Study: Light-Duty Vehicle Testing, Data, and Analysis 04/07/2003
Gabele, P A. Gasoline/Diesel PM Split Study: Light-Duty Vehicle Testing, Data, and Analysis. Presented at Thirteenth CRC On-Road Vehicle Emissions Workshop, San Diego, CA, April 7-9, 2003.
Abstract: During June 2001, the EPA participated in DOE's Gasoline/Diesel PM Split Study in Riverside, California. The purpose of the study was to determine the contribution of diesel versus gasoline-powered exhaust to the particulate matter (PM) inventory in the South Coast Air Basin. The EPA participation, which was performed under contract with CAVTC, involved recruiting (with the assistance from the California Bureau of Automotive Repair), conducting dynamometer tests, and measuring PM2.5, regulated, and gaseous air toxic emissions from 59 light-duty motor vehicles.
This presentation describes emission rates obtained for PM2.5, regulated pollutants, and gaseous air toxic compounds that were measured from the gasoline-powered test cars. Emission rates from the test vehicles are presented in context to the category in which they were recruited. Vehicles were recruited into eleven different categories based upon their age and mileage, except that one category consisted entirely of "smokers" and one of light-duty diesels. In general, emissions from the older, high mileage cars contributed the bulk of pollutant emissions from the test fleet. None of the gasoline-powered vehicles tested had a PM2.5 emission rate exceeding 200 mg/mile for the weighted, cold-start LA-92 test that was run. Therefore, it appeared that no grossly high PM emitters were recruited into this study. Comparison of emission rates derived from dilution tunnel sampling versus those from sampling in a residence chamber is made.

This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.


PRESENTATION Biogenic Contribution to PM-2.5 Ambient Aerosol from Radiocarbon Measurements 04/06/2003
Lewis, C W., G. A. Klouda, AND W. D. Ellenson. Biogenic Contribution to PM-2.5 Ambient Aerosol from Radiocarbon Measurements. Presented at European/American Geophysical Union Joint Assembly, Nice, France, April 6-11, 2003.
Abstract: Knowledge of the relative contributions of biogenic versus anthropogenic sources to ambient aerosol is of great interest in the formulation of strategies to achieve nationally mandated air quality standards. Radiocarbon (Carbon-14) measurements provide a means to quantify the biogenic fraction of any carbon-containing sample of ambient aerosol. In the absence of an impact from biomass burning (e.g., during summertime) such measurements can provide an estimate of the contribution of biogenic secondary organic aerosol, from biogenic volatile organic compound precursors. Radiocarbon results for 11.5-h PM-2.5 samples collected near Nashville, Tennessee, USA, during summer 1999 will be presented. On average the measured biogenic fraction was surprisingly large (more than half), with the average biogenic fraction for night samples being only slightly smaller than for day samples. Discussion will include (a) description of the radiocarbon methodology, (b) use of radiocarbon measurements on local vegetation and fuel samples as calibration data, (c) concurrent measurements of organic carbon and elemental carbon ambient concentrations, (d) assessment of organic aerosol sampling artifact through use of organic vapor denuders, variable face velocities, and filter extraction, and (e) comparison with published radiocarbon results obtained in Houston, Texas in a similar study.
This work has been funded wholly or in part by the United States Environmental Protection Agency under Interagency Agreement No. 13937923 to the National Institute of Standards and Technology, and Contract No. 68-D5-0049 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication.

PRESENTATION The Relationship Between Both Real-Time and Time-Integrated Coarse and Fine Particulate Matter at An Urban Site in Los Angeles 04/04/2003
Geller, M. D., P. M. Fine, C. Sioutas, AND P A. Solomon. The Relationship Between Both Real-Time and Time-Integrated Coarse and Fine Particulate Matter at An Urban Site in Los Angeles. Presented at Particulate Matter: Atmospheric Sciences, Exposure and the Fourth Colloquium on PM and Human Health, Pittsburgh, PA, March 31-April 4, 2003.
Abstract: Population exposure to ambient particulate matter (PM) has received considerable attention due to the association between ambient particulate concentrations and mortality. Current toxicological studies and controlled human and animal exposures suggest that all size fractions of PM may be responsible for observed health effects. Recently, technologies for continuously measuring coarse and fine PM mass concentrations have been developed and/or improved. In this study, coarse (PM10-PM2.5) and fine (PM2.5) PM mass concentrations near a typical urban site are measured with both continuous sampling devices and a time-integrated sampling device. The collocated continuous monitors include: a Beta Attenuation Monitor (BAM) to measure PM2.5, an ESP differential Tapered Element Oscillating Microbalance (TEOM) to measure PM2.5, a Scanning Mobility Particle Sizer (SMPS) and Aerodynamic Particle Sizer (APS) to measure both coarse and fine PM, and a Continuous Coarse Monitor (CCM) to measure coarse PM. This device consists of a 2.5 um cutpoint virtual impactor placed upstream of a Tapered Element Oscillating Microbalance (TEOM). Time-integrated samples are taken every sixth day with a Micro-Orifice Uniform Deposit Impactor (MOUDI).
The main objective of this study is to document bot1 short-term and diurnal variation in ambient fine and coarse particulate mass concentrations with respect to each other while considering the effects of sources, weather, wind speed and wind direction. Of particular interest will be how well each size fraction tracks the other, for this will yield insight on the contributions of particular sources to each mode during various conditions.

This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Individual Particle Analysis of Personal Samples from the 1998 Baltimore Particulate Matter Study 04/03/2003
Conner, T L. AND R W. Williams. Individual Particle Analysis of Personal Samples from the 1998 Baltimore Particulate Matter Study. Presented at Atmospheric Sciences, Exposure and Fourth Colloquium on PM and Human Health, Pittsburgh, PA, March 31-April 4, 2003.
Abstract: The United States Environmental Protection Agency (U.S. EPA) recently conducted the 1998 Baltimore Particulate Matter (PM) Epidemiology-Exposure Study of the Elderly. The primary goal of that study was to establish the relationship between outdoor PM concentrations and actual human PM exposures within a susceptible (elderly) sub-population. The study design included PM2.5 personal exposure samples obtained from elderly (65+ years of age) residents of an eighteen story retirement facility near Baltimore, Maryland. In addition, the personal exposure sampling devices were used to obtain PM2.5 samples at fixed locations within the personal monitoring subjects' apartments. Apartment residence and personal samples collected on Teflon fiber filters were examined using scanning electron microscopy with individual-particle X-ray analysis (SEM/EDX) to provide a qualitative assessment of the chemical and physical characteristics of geological and trace element particles collected within these micro-environments at the retirement facility. Qualitative differences among the selected personal and apartment residence samples were observed. Differences between the paired personal and apartment samples indicate the localized nature of certain particle types.
This work has been funded by the United States Environmental Protection Agency under contract #68-D5-0040 to the Research Triangle Institute and under contract #68-D5-0049 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Linkages Across PM Policy and Research: Examining the Policy Relevant Findings from the PM2.5 Supersites Program 04/03/2003
Scheffe, R., J. Bachmann, AND P A. Solomon. Linkages Across PM Policy and Research: Examining the Policy Relevant Findings from the PM2.5 Supersites Program. Presented at 2003 AAAR PM Meeting, Pittsburgh, PA, March 31-April 4, 2003.
Abstract: The PM2.5 Supersites program was designed to complement routinely operating PM2.5 networks by providing enhanced temporal and chemical/physical composition data in addressing three overarching objectives: supporting health effects and exposure research, advanced monitoring methods development and testing, and increased air quality characterization in support of national and State emission reduction strategies. As the Supersites are in the final stages of an intensive measurement campaign in eight cities across the United States that commenced in 1999, the program is expected to provide relevant information for the technical assessments underlying development of national and State implementation plans (SIPs) that currently are underway and expected to continue over the next five years. The objective of this paper is to illustrate the program design attributes and highlight selected preliminary findings from the Supersites, and related PM research efforts, that should support these planning efforts.
This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Analysis of Discriminating Factors in Human Activities That Affect Exposure 04/02/2003
Graham, S E. AND T R. McCurdy. Analysis of Discriminating Factors in Human Activities That Affect Exposure. Presented at 2003 Carolinas Society of Environmental Toxicology and Chemistry Annual Meeting, Charleston, SC, April 2-4, 2003.
Abstract: Accurately modeling exposure to particulate matter (PM) and other pollutants ultimately involves the utilization of human location-activity databases to assist in understanding the potential variability of microenvironmental exposures. This paper critically considers and statistically tests key factors thought to be important in explaining the choices people make in where they spend time. Three aggregate locations were analyzed: outdoors, indoors, and in-vehicles for two different sample groups. As part of an initial study, a year-long (longitudinal) sample of one individual was compared with a cross-sectional sample of 169 individuals from USEPA's Consolidated Human Activity Database (CHAD) similar to the longitudinal sample in terms of age, work status, education, and residential type. The sample groups were remarkably similar in the time spent per day in the tested locations, although there were differences in participation rates (percentage of days in a particular location). Time spent outdoors exhibits the most relative variability of any location tested, and in-vehicle time being the next. The factors found to be most important in explaining daily time usage in both sample groups are seasons, season/temperature combinations, precipitation levels, and day-type (work/non-work is the most distinct, but weekday/weekend is also significant). Season, season/temperature, and day-type are also important for explaining time spent indoors, however none of the variables tested are consistent in explaining in-vehicle time in either the cross-sectional or longitudinal samples. The design and results of this study were applied to an analysis of CHAD in its entirety, comprised of 22,968 person days of location-activity data from 12 individual human activity pattern studies. In addition to the above factors, study effects were considered along with a detailed analysis of the effect various attribute-based sample pools have in human exposure cohort development. There were significant differences between studies that can potentially introduce bias when considering time spent in specific locations and, when studies are considered inclusively to a sample pool, could potentially add error to exposure estimates.
Given these findings, we recommend that PM and other exposure modelers subdivide their population activity data into at a minimum temperature, precipitation, and day-type cohorts as these factors are important discriminating variables affecting where people spend their time. Temperature and precipitation levels are also important factors in modifying PM concentrations, and without considering meteorological influence on both human activities and concentrations would further contribute to erroneous exposure estimates. Furthermore, exposure modelers using CHAD also need to consider study selection carefully since not all of the individual studies in CHAD collected the same information.

This work has been funded by the United States Environmental Protection Agency. It has been subjected to Agency review and approved for publication.

PRESENTATION Preliminary Results of EPA's Performance Evaluation of Federal Reference Methods and Federal Equivalent Methods for Coarse Particulate Matter 04/01/2003
Solomon, P A., T G. Ellestad, T L. Conner, R B. Zweidinger, M K. Harmon, R. W. Vanderpool, B. Murdoch, S. Natarajan, C. A. Noble, L. Byrd, T. Hanley, AND R. Scheffe. Preliminary Results of EPA's Performance Evaluation of Federal Reference Methods and Federal Equivalent Methods for Coarse Particulate Matter. Presented at Particulate Matter: Atmospheric Sciences, Exposure and the Fourth Colloquium on PM and Human Health, Pittsburgh, PA, March 31-April 4, 2003.
Abstract: The main objective of this study is to evaluate the performance of sampling methods for potential use as a Federal Reference Method (FRM) capable of providing an estimate of coarse particle (PMc: particulate matter with an aerodynamic diameter between 2.5 µm and 10 µm) mass concentrations in ambient air. Three sampling approaches are being evaluated. These approaches include a discrete method for measuring coarse particles directly using a sequential sampler; a discrete difference method, which uses two samplers, one to measure PM2.5 the other PM10 with the difference, PM10-PM2.5, representing an estimate of PMc; and two continuous coarse particle samplers that measure PMc directly with a time resolution of less than 1 hour. The direct sequential and continuous methods use the dichotomous virtual impactor for separating fine and coarse particles. The samplers will be evaluated in three locations that provide diverse challenges to the samplers, including high PMc to PM10, high PM2.5 to PM10, and an intermittent site (impacted by a source to see high and low values) under cold conditions. This presentation will provide preliminary results from the first location with (high PM2.5 to PM10).
This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use..

PRESENTATION Determining Coarse Particulate Matter Concentrations: A Performance Evaluation of Candidate Methodologies Study Design and Results from the RTP Equipment Shakedown 04/01/2003
Vanderpool, R. W., R. Murdoch, S. Natarajan, C. A. Noble, P A. Solomon, T G. Ellestad, T L. Conner, R B. Zweidinger, M K. Harmon, T. Hanley, L. Byrd, R. Scheffe, J. Ambs, G. Sem, AND J. Tisch. Determining Coarse Particulate Matter Concentrations: A Performance Evaluation of Candidate Methodologies Study Design and Results from the RTP Equipment Shakedown. Presented at Fourth Colloquium on PM and Human Health, Pittsburgh, PA, March 31-April 4, 2003.
Abstract: The main objective of this study is to evaluate the performance of candidate sampling methods for potential use as a Federal Reference Method (FRM) capable of providing an estimate of coarse particle (PMc: particulate matter with an aerodynamic diameter between 2.5 um and 10 um) mass concentrations in ambient air. Five sampling approaches are being evaluated. These approaches include a discrete method for measuring coarse particles directly using a commercial sequential dichotomous sampler; and a discrete difference method, which uses two commercial FRM samplers, one to measure PM2.5 the other PM10 with the difference, PM10-PM2.5, representing an estimate of PMc. Filters from these two sampler types are analyzed gravimetrically. The study also evaluates two continuous coarse particle samplers which measure PMc directly with a time resolution of one hour: one a commercial automated dichot and the other a prototype dichot that measures PMc directly. The direct sequential and continuous dichotomous methods use a virtual impactor for separating fine and coarse particles. The final PMc sampler is an aerodynamic particle sizer which measures aerosol size distribution then uses the collected data to estimate the PMc mass concentration. The samplers will be evaluated in three locations that provide diverse challenges to the samplers, including high PMc to PM10, high PM2.5 to PM10, and a site impacted by high and low values under cold conditions.
This work has been funded in part by the United States Environmental Protection Agency under contract number 68-D-00-206 to ManTech Environmental Technology, Inc. It has been subjected to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Aerosol and Gas Measurement 04/01/2003
Fehsenfeld, F. C., D. Hastie, J. C. Chow, AND P A. Solomon. Aerosol and Gas Measurement. Presented at Particulate Matter: Atmospheric Sciences, Exposure and the Fourth Colloquium on PM and Human Health, Pittsburgh, PA, March 31-April 4, 2003.
Abstract: Measurements provide fundamental information for evaluating and managing the impact of aerosols on air quality. Specific measurements of aerosol concentration and their physical and chemical properties are required by different users to meet different user-community needs. Before acceptable measurement techniques and sampling strategies can be specified to meet one or all of these diverse PM measurement user-community needs, it is necessary to understand the available sampling and analysis approaches along with their uncertainties and costs. To provide these measurements, different types and configurations of instruments have been developed and deployed. These include methods that measure and quantify either over time (integrated measurements, e.g., 24-hrs) or in real-time (semi-continuous or continuous methods) the observable properties of particles: size and size distribution, mass, chemical composition, and optical characteristics. Related variables that affect PM concentrations in air include water content (fogs and clouds), meteorological parameters, and gases that significantly influence atmospheric chemistry or are direct PM species precursors. Quantification of uncertainty of these measurements also is critical to the user communities since it forms the basis of our ability to interpret and apply data in an effective manner. This poster briefly outlines the discussion presented in the NARSTO Aerosol Assessment that describes the types of measurement techniques available, how the information obtained through PM measurements is applied, and the confidence that can be placed in the data's accuracy and precision.
This is an abstract of a proposed presentation and does not necessarily reflect the United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION The Role of Subpopulation, Disease State, Housing, Season and Other Factors Upon Personal Exposures to PM of Ambient Origin 03/31/2003
Williams, R W., J C. Suggs, G F. Evans, A W. Rea, L S. Sheldon, A F. Vette, J M. Burke, C Croghan, K W. Leovic, J P. Creason, D Walsh, C. Rodes, J. Thornburg, P. A. Lawless, A. Ejire, M. Herbst, AND W. Sanders Jr. The Role of Subpopulation, Disease State, Housing, Season and Other Factors Upon Personal Exposures to PM of Ambient Origin. Presented at 2002 AAAR PM Meeting, Pittsburgh, PA, March 31-April 4, 2003.
Abstract: A series of longitudinal particulate matter (PM) and related co-pollutant human exposure panel field studies have recently been completed. Studies were conducted in Baltimore, Maryland (1997,1998) Fresno, California (1999) and Research Triangle Park, North Carolina (2002-2001) and were designed to evaluate the effects of personal exposures to PM of ambient origin under differing sub-populations, regions of the country, seasons, and housing conditions. Participants were monitored over time (28 days) to investigate both longitudinal and cross-sectional correlations between personal, residential indoor, residential outdoor, and ambient measurements. Measurements of PM2.5, PM10 and PM10-2.5 were routinely performed. Copollutant monitoring included CO, O3, NO2, SO2, elemental-organic carbon and metals. Daily time activity diaries and questionnaires were used to document potential sources and influences of PM from all sources. The studies involved a variety of potentially susceptible subpopulations made up of non-smoking, ambulatory volunteers being at least 55 years old. The various cohorts included healthy participants as well as a majority with various pulmonary and cardiovascular disease states such as hypertension. Some of the subjects lived in communal (apartment or cottage-style) housing while others lived in single family residences. The influence of participant lifestyle and employment status was also examined. Approximately 7000 PM mass measurements were obtained from all of these studies. Results revealed a wide range in the magnitude and variability of daily personal PM2.5 exposures (3 to 200 ug/m3). Time activity patterns and estimated exposures to indoor generated sources appeared to be some of the primary factors influencing personal to ambient PM mass concentration associations (ranging from 0.0 to 0.95). Working status did not appear to be highly influential relative to total personal PM2.5 exposure. Mean personal PM2.5 clouds ranged from 3 to 10 ug/m3 relative to the various study populations and were clearly influenced by individual time activity patterns among the participants. PM2.5 ambient mass concentration homogeneity across areas up to 70 km was observed. Results from the RTP-based study show that ambient PM2.5 sources contributed to approximately 50% of the total personal exposure mass concentration regardless of season, residence, occupational status or disease state.
This work has been funded wholly by the United States Environmental Protection Agency under contract #68-D5-0040 and 68-D-99-012 to the Research Triangle Institute and assistance agreement #CR-828186-01-0 to Shaw University. It has been subjected to Agency review and approved for publication.

PRESENTATION Associations Between Particulate Matter Components and Daily Mortality and Morbidity in Philadelphia, Pa 03/31/2003
Ito, K., M S. Landis, W Wilson, AND G. Thurston. Associations Between Particulate Matter Components and Daily Mortality and Morbidity in Philadelphia, Pa. Presented at 2003 AAAR PM Meeting, Pittsburgh, PA, March 31-April 4, 2003.
Abstract: In evaluating the health risks from particulate matter (PM), the question remains as to which component(s) of PM are most harmful. We investigated this issue using PM mass, PM constituents, mortality, and the elderly hospital admission data in Philadelphia, PA. Daily paired PM2.5 and PM10 samples were collected at one site in downtown Philadelphia between May 1992 and September 1995. Trace elements as analyzed by energy dispersive X-ray fluorescence from PM2.5 filters (including Br, Ca, Fe, K, Mn, Ni, S, Se, Si, V, and Zn), gaseous pollutants (CO, NO2, SO2, and O3), and coefficient of haze (CoH) were also considered in the health effects analyses. Daily cardiovascular mortality, total (non-accidental) mortality, cardiovascular elderly (age over 65) hospital admissions, and respiratory elderly hospital admissions were aggregated for the Philadelphia Metropolitan Statistical Area. Generalized Linear Poisson regression Model (GLM) was used to estimate the excess health outcomes associated with PM components and gaseous pollutants adjusting for temporal trends, weather, day-of-week, and major holidays. Several alternative weather models, as well as varying extent of seasonal smoothing, were applied to examine the sensitivity of results to model specifications. Among the PM components examined, most consistent associations with health outcomes were observed for PM2.5, PM10 (70% of whose mass, on the average, was PM2.5), and sulfur. The PM2.5 (lag 1 day) relative risk estimate for cardiovascular mortality, for example, ranged from about 2 to 4% per 25 ug/m3 increase, depending on the weather model specification and seasonal trend smoothing (natural splines) between 4 to 12 degrees of freedom. PM10-2.5 was not significantly associated with any of the health outcomes. These results suggest the strongest PM associations are between regionally uniformly distributed secondary aerosol and health outcomes in Philadelphia during this time period.
This work has been wholly funded by the United States Environmental Protection Agency under cooperative agreement number CR827358 to New York University School of Medicine. It has been subjected to Agency Review and approved for publication.

PRESENTATION Development of Urinary Metabolite Biomarkers to Assess Population Exposure to PM2.5 from Various Combustion Sources 03/31/2003
Lewtas, J, S. Myers, C. Simpson, R. Dills, AND D. Kalman. Development of Urinary Metabolite Biomarkers to Assess Population Exposure to PM2.5 from Various Combustion Sources. Presented at 2003 AAAR PM Meeting, Pittsburgh, PA, March 31-April 4, 2002.
Abstract: A primary goal of our research is to validate the use of urinary biomarkers to apportion the sources of human exposure to PM2.5. Organic source tracers have been used in source apportionment studies of ambient PM2.5 to distinguish a range of combustion sources. Both gas and particle-phase organic tracer species have been used as biomarkers of exposure to combustion sources. The nicotine urinary metabolite, cotinine, is an example of a well-validated biomarker of exposure to tobacco smoke that has been successfully used in large population studies. Polycyclic aromatic hydrocarbons (PAH) and their urinary metabolites have been used as exposure markers for combustion sources including traffic and coal sources. Levoglucosan (1,6 -anhydro--D-glucose) found in particles and methoxyphenols (lignin combustion products found in both gas and particle phase) are source tracers for woodsmoke. Levoglucosan is a conserved and stable organic tracer for ambient exposure measurements. Methoxyphenols, although less stable when collected on filters, are metabolized and excreted as urinary metabolites. In ongoing ambient and personal exposure studies in Seattle, where woodsmoke and mobile sources (diesel and gasoline) are the major sources of PM2.5, both organic and inorganic source tracers are measured in personal, indoor and outdoor filter samples. Urinary samples are collected and metabolites of these source tracers are measured using GC/MS and HPLC. Validation studies include 1) correlating the exposure to methoxyphenols, levoglucosan and PAH in home-indoor and home-outdoor samples, and 2) examining the relationship between exposure to levoglucosan and PAH in personal air samples and excretion of methoxyphenols and PAH metabolites in urine. Initial studies are examining the time course of exposure and excretion over 10 day sampling periods in susceptible and normal populations. These studies have been conducted in subjects (n=6) that experienced a range of PM2.5 exposure variations over the 10 day period. Mean home-outdoor PM2.5 concentrations for these subjects were 18.8 ug/m3; (range 5.0-41.5 ug/m3), and mean home-outdoor levoglucosan concentrations were 501 ng/m3; (range 88-1214 ng/m3). Studies to determine the half-life of these urinary metabolites are also in progress.
This work has been funded by the U S EPA (Cooperative Agreement #R827177 & EPA Northwest Research Center). It has been subjected to Agency review and approved for publication.



PRESENTATION Using Zero-Valent Metal Nanoparticles to Remediate Organic Contaminants 03/24/2003
Strynar, M J., B. Schrick, B. N. Will, J. Dec, T. E. Mallouk, AND J. M. Bollag. Using Zero-Valent Metal Nanoparticles to Remediate Organic Contaminants. Presented at 225th American Chemical Society National Meeting, New Orleans, LA, March 23-27, 2003.
Abstract: The transport of organic contaminants down the soil profile constitutes a serious threat to the quality of ground water. Zero-valent metals are considered innocuous abiotic agents capable of mediating decontamination processes in terrestrial systems. In this investigation, zero-valent Fe, Ni-Fe, and Pd-Fe were assessed for their ability to reduce the chlorinated solvent trichloroethylene (TCE) and the dinitroaniline herbicide trifluralin. TCE treated with metal nanoparticles was reduced to saturated hydrocarbons via hydrodechlorination. Trifluralin was transformed to amino derivatives that formed stable complexes with quinone moieties of fulvic acid as a result of nucleophilic addition. In view of these results, zero-valent metals emerge as an efficient tool for neutralizing a host of environmental contaminants. However, since the later frequently reside in hard to reach locations within the soil profile, it is necessary to develop tools for transporting the zero-valent metals to the target sites.
The work described in this paper was not funded by the U.S. Environmental Protection Agency, and therefore, the contents do not necessarily reflect the views of the Agency and no official endorsement should be inferred.

PRESENTATION The Importance of Obtaining Information on the Specific Content of Tissue Enzymes Metabolizing Organophosphorus Pesticides, Prior to Determining Vmax, Km Values for Use in PBPK Models 03/23/2003
Knaak, J. B., F W. Power, J N. Blancato, AND C C. Dary. The Importance of Obtaining Information on the Specific Content of Tissue Enzymes Metabolizing Organophosphorus Pesticides, Prior to Determining Vmax, Km Values for Use in PBPK Models. Presented at American Chemical Society, New Orleans, LA, March 23-27, 2003.
Abstract: Physiological pharmacokinetic\pharmacodynamic models require Vmax, Km values for the metabolism of OPs by tissue enzymes. Current literature values cannot be easily used in OP PBPK models (i.e., parathion and chlorpyrifos) because standard methodologies were not used in their determination. In practically all cases, the investigators failed to determine the specific content of the enzymes of interest in tissues or tissue fractions (PON1 and P450 isozymes) under investigation prior to use, by either spectral or immunochemical methods. The concentration of plasma PON1 (paraoxonase) may vary as much as 60 to 600 ug/ml making it difficult to select proper enzyme-substrate concentrations for the determination of Vmax, Km. The same problem exists measuring P-450 activity using microsomal protein, when the specific content (pmoles of P-450, total or individual CYPs) in the microsomes is unknown. Rendic and Guengerich recently recommended individual CYPs (i.e, 1A2, 2B6, 2D6 and 3A4) be used to obtain Vmax, Km values in place of human whole liver microsomes. Mathematical equations are available for expressing individual CYP data (specific content and activity) in terms of native liver microsomes and using the data in PBPK models. Methods will be presented for obtaining Vmax, Km values for parathion and chlorpyrifos based on the specific content of PON1 and P-450 in plasma and liver microsomes.
The U.S. Environmental Protection Agency (EPA), through its Office of Research and Development (ORD), funded this research and approved this abstract as a basis for an oral presentation. The actual presentation has not been peer reviewed by EPA.

PRESENTATION (Prague)BIOMARKERS of Exposure to Particulate Air Pollution in the Czech Republic 03/14/2003
Lewtas, J, B. Binkova, I. Miskova, P. Subrt, AND J. Lenicek. (Prague)BIOMARKERS of Exposure to Particulate Air Pollution in the Czech Republic. Presented at Proceedings of Workshop on Advances in Human Research, Prague, Czech Republic, March 14-23, 2003.
Abstract: The use of biomarkers in the Teplice Program, provided a key tool to relate health outcomes to individual personal exposures and to provide measures of confounding exposures. This research program on the health effects of air pollution studied a population living in the heavily industrialized district of Teplice in North Bohemia and compared the exposure and health of this population to that of a non-industrialized district, Prachatice, in Southern Bohemia. The studies included characterization of the environmental and personal air pollution exposure, biomarkers, and studies on reproductive, respiratory, and neurobehavioral effects. Biomarkers were measured in blood, urine, placenta, and sperm. The biomarkers included measures of exposure (e.g., urine metabolites and blood metals), dose (e.g., DNA adducts), DNA damage, genetic and cytogenetic effects, and susceptibility. During winter temperature inversions, unusually high concentrations of a complex mixture of air pollutants were measured, including fine particles, genotoxic organic compounds, and toxic trace elements. This population, however, was also exposed to multiple pollutants via all pathways, and including pollutants resulting from environmental exposures, occupational exposures, and personal habits (e.g., tobacco and alcohol use). Longitudinal and repeated measures used individuals as their own control to examine the influence of environmental exposures as they changed over time and season. Chronic and seasonal exposures to elevated air pollution in the Teplice District were shown to have serious adverse respiratory health consequences for children and reproductive effects in adults. Elevated levels of air pollutants, even for short-term winter inversions resulted in measurable uptake, metabolism, and excretion of polycyclic aromatic hydrocarbons, increased blood concentrations of toxic metals, and resulted in DNA damage. Results of the exposure, biomarker, and health studies indicated that environmental exposure to a complex mixture of air pollutants resulted in significant elevations in personal exposure, uptake, excretion of pollutants and DNA damage.
This paper has been reviewed in accordance with the US Environmental Protection Agency's peer and administrative review policies and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION In Vitro Determination of Kinetic Constants for 1,3-Dichloropropane, 2,2-Dichloropropane, and 1,1-Dichloropropene in Rat Liver Microsomes and Cytosol 03/09/2003
TORNERO-VELEZ, R., J. Laskey, AND M V. Evans. In Vitro Determination of Kinetic Constants for 1,3-Dichloropropane, 2,2-Dichloropropane, and 1,1-Dichloropropene in Rat Liver Microsomes and Cytosol. Presented at Society of Toxicology, Salt Lake City, UT, March 9-13, 2003.
Abstract: The Safe Drinking Water Act requires the U.S. EPA to establish a list of contaminants to aid in priority setting for the Agency's drinking water program. The 1998 Contaminant Candidate List (CCL) designated 1,3-Dichloropropane (1,3-DCP), 2,2-dichloropropane (2,2-DCP), and 1,1-dichloropropene (1,1-DCP) for health effects research. We determined kinetic constants for these compounds for cytochrome P450 and glutathione (GSH)-dependent conjugation because these pathways play an important role in the toxicity of halogenated hydrocarbons. Hepatic microsomal (M) and cytosolic (C) fractions were prepared from male Fisher 344 rats and an automated equilibrium headspace technique was employed to assess substrate loss. Headspace concentrations were determined by gas-chromatography and concentration time-courses were modeled with a two-compartmental gas-medium model and analyzed with Matlab?. We observed no metabolism for 2,2-DCP via the glutathione-dependent conjugation pathway and only a minor level of clearance via the P450 pathway (7x10-4 L/h/mg M-protein). The clearance of 1,3-DCP via the P450 pathway was substantially greater than that of 2,2-DCP (4.1x10-2 L/h/mg M-protein; Vmax=641 pmol/min/mg M-protein, Km=0.95 uM). The clearance of 1,3-DCP via the GSH conjugation pathway was minor relative to the P450 pathway (2.4x10-4 L/h/mg C-protein; 0.6% of microsomal rate), and was consistent with the results of other a,w-dihaloalkanes that show increased rates of GSH conjugation with increasing chain length. The clearance of 1,1-DCP via the P450 pathway (2.26x10-2 L/h/mg M-protein; Vmax=3430 pmol/min/mg M-protein, Km=2.5 uM ) was substantially greater than for the GSH conjugation pathway (3.9x10-4 L/h/mg C-protein; 1.72% of microsomal rate). In summary, this in vitro approach has proven useful in evaluating the metabolism of volatile halogenated hydrocarbons. These rate constants may be incorporated in pharmacokinetic (PK) models to predict in vivo kinetics.
This is an abstract of a proposed presentation and does not necessarily reflect United States Environmental Protection Agency (EPA) policy. The actual presentation has not been peer reviewed by EPA. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.


PRESENTATION Ord PM Methods Research Program 03/04/2003
Solomon, P A., R B. Zweidinger, G A. Norris, J Lewtas, C W. Lewis, AND M K. Harmon. Ord PM Methods Research Program. Presented at Organic Carbon and Elemental Carbon Meeting, Durango, CO, March 4-5, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Interlaboratory Comparison Studies for Characterization of Organic Compounds in Particulate Matter 03/03/2003
Schantz, M. M., S. A. Wise, AND J Lewtas. Interlaboratory Comparison Studies for Characterization of Organic Compounds in Particulate Matter. Presented at 2003 AAAR PM Meeting, Pittsburgh, PA, March 3-April 4, 2003.
Abstract: A working group of investigators, who are characterizing and quantifying the organic compounds in particulate matter (PM) as part of the US EPA's PM 2.5 research program and related studies, was established three years ago to advance the quality and comparability of data on the organic composition of PM. This group has just completed their second interlaboratory comparison study. The first study used a subset of SRM 1649a (Urban Dust, sieved to <123 micrometer) that had been sieved to <63 micrometer (Air Particulate I) as an unknown PM sample. In addition to Air Particulate I, the participants received a dichloromethane extract of Air Particulate I as a second unknown sample and a sample of SRM 1649a for use as a control material. For the second study, initiated in March 2002, the participants received a sample of PM2.5 collected recently in Baltimore, MD along with a sample of SRM 1649a. It is a requirement that all participants return data on Air Particulate I and SRM 1649a prior to receiving the Baltimore PM2.5 material, so at this point there are participants at different stages of the two studies. The target analytes, organic source tracers and toxic species, include polycyclic aromatic hydrocarbons (PAHs), nitrated PAHs, alkanes (including hopanes and cholestanes), sterols, carbonyl compounds (ketones and aldehydes), acids (alkanoic and resin), phenols, and sugars. Because this is a performance-based study, laboratories are encouraged to use the methods that they are routinely using in their laboratories to analyze similar samples. Laboratories are requested to return data from three analyses (subsamples) of each sample provided along with a summary of the methods used. The data received from the participating laboratories, following outlier testing, are then used to assign a consensus value to each analyte in the unknown samples. Results are used in the consensus value assignment for the unknown PM sample only if the laboratory's results for SRM 1649a are within 30% of the uncertainty limits of the certified values. The consensus values, accuracy and precision assessments, and the methods used by each laboratory are summarized in a report provided to the participants. In this report, laboratories are numerically identified with only the laboratory and the study coordinators knowing this numerical identification. The results from the two interlaboratory studies will be presented along with plans for future interlaboratory trials, standard reference materials, and calibration standards.
This work has been funded by the U S Environmental Protection Agency. It has been subjected to Agency review and approved for publication.



PRESENTATION Preliminary Results from EDC Investigation of Selected Neuse River Sites: Toxic Elements 02/25/2003
Coppedge, E A. AND S L. Harper. Preliminary Results from EDC Investigation of Selected Neuse River Sites: Toxic Elements. Presented at Emerging Environmental Technologies Seminar, Durham, NC, February 25, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION EPA Compendium Methods to-15, to-15 Supplement (Draft), and to-17 for Monitoring Vocs in Air 02/25/2003
McClenny, W A. EPA Compendium Methods to-15, to-15 Supplement (Draft), and to-17 for Monitoring Vocs in Air. Presented at Seminar on Indoor Air Vapor Intrusion, Atlanta, GA, February 24-25, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION The UV Monitoring Research Program 02/24/2003
Hall, E S. The UV Monitoring Research Program. Presented at US Global Change Research Program Seminar, Washington, DC, February 24, 2003.
Abstract: There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field.

PRESENTATION Organic Compounds Measured in PM2.5 During Neops 02/09/2003
Edney, E O., R E. Speer, T. E. Kleindienst, E. W. Corse, AND C. D. McIver. Organic Compounds Measured in PM2.5 During Neops. Presented at 83rd American Meteorological Society Annual Meeeting, Long Beach, CA, February 9-13, 2003.
Abstract: Secondary formation of submicron ambient particulate matter occurs when organic and inorganic constituents having sufficiently low volatility condense onto preexisting particles in the atmosphere. The presence of the resulting submicron particles has led to three important environmental problems. First, visibility degradation leading to haze occurs due to light scattering imposed by these particles. This problem is especially pronounced in the Southeastern United States during the summertime because of high temperatures and high relative humidities (Sisler and Malm, 1994), which result in high levels of particle liquid water leading to increases in the particle diameter. Second, submicron particles are associated with changes in radiative forcing and may be expected to influence the factors leading to global climate changes (Charlson et al., 1992). Finally, epidemiological studies (Schwartz et al., 1996) have implicated fine particulate matter with increased mortality and morbidity in selected urban areas. Since the specific causal agents for observed adverse health effects are not presently known, it has become an important task to chemically characterize the specific organic components of ambient fine particulate matter as completely as possible.
This work has been funded wholly or in part by the United States Environmental Protection Agency under Contract 68-D00-206 to ManTech Environmental Technology, Inc. It has been subject to Agency review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PRESENTATION Research Program for Brace Providing No and Specific NO2 Measurements for the Brace Database During the May '02 Field Study 02/04/2003
Kronmiller, K. G., M. L. Wheeler, AND W A. McClenny. Research Program for Brace Providing No and Specific NO2 Measurements for the Brace Database During the May '02 Field Study. Presented at BRACE Field Study Workshop, Tampa, FL, February 3-4, 2003.
Abstract: Three scientists from the EPA, RTP facility in Research Triangle Park, N.C. worked with the State of Florida and BRACE scientists to provide accurate and precise NO and specific NO2 measurements at two monitoring sites, the rural Sydney site and the near-bay, suburban Gandy site. Most ambient measurements of NO2 are not specific and usually provide only an upper limit for NO2. However, the use of a photolytic converter to convert NO2 to NO can be used with a NO,O3 chemiluminescence detector to provide more specific NO2 measurements. The EPA monitoring effort is the first application of a commercially available, stand-alone photolytic converter that can be adapted for use with existing trace level chemiluminescence monitors. These measurements contribute to the overall BRACE database. Atmospheric models will be applied to the database in an attempt to model the atmospheric processes occurring in the Tampa area such as atmospheric chemistry and deposition of atmospheric constituents.
This extended abstract has been subjected to the Agency's peer and administrative review and has been approved for publication as an EPA document. Mention of trade names of commercial products does not constitute endorsement or recommendation for use.

PUBLISHED REPORT Method to-15 Supplement-Analysis of 1,1-Dce at Pptv Concentrations 09/09/2003
Oliver, K. D., H. H. Jacumin Jr., E. H. Daughtrey Jr., AND W A. McClenny. Method to-15 Supplement-Analysis of 1,1-Dce at Pptv Concentrations. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/R-03/109 (NTIS PB2004-100892), 2003.
Abstract: The Supplement to EPA Compendium Method TO-15 provides guidance for reducing the method detection limit (MDL) for the compound 1,1-dichloroethene (1,1-DCE) and for other volatile organic compounds (VOCs) from 0.5 ppbv, as cited in Method TO-15, to much lower concentrations. Revisions to the original wording of Method TO-15 were made where the original language proved limiting to the goal of extending Method TO-15 to low pptv levels or where omissions or errors were observed. Also, recommendations in the form of additions were made on aspects of laboratory procedure deemed critical to low-pptv-level analysis. Specifically, the MDL for 1, l-DCE was determined to be 6 pptv. During this effort, a capability for preparing 1,1-DCE sample concentrations of 30 pptv and 60 ppbv in ambient air was developed. Using this capability and the capability to prepare samples of humidified zero air, samples were prepared in canisters and sent to three contract laboratories as unknowns. Subsequent comparison of results indicated close agreement among the laboratories while maintaining the performance standards for replicate precision (25%) and audit accuracy (30%) originally specified in Method TO-15. The following compounds were also detected at low pptv levels in canisters filled with spiked ambient air: chloroethene, dichloromethane, cis-l,2-dichloroetherie, trichloro-methane, 1,2-dichloroethane, benzene, 1,1,1 -trichloroethane, trichloroethene, andtetrachloroethene. Since the different laboratories employed different analytical procedures, the use of a performance-based method appears justified. Specific guidance on analytical procedures from the Colorado Department of Public Health and Environment (CDPHE) is provided. These procedures have proven useful for CDPHE's contract laboratories in analyzing pptv-level samples of VOCs. The procedures followed by the EPA on-site contractor, ManTech Environmental Technology, Inc., in preparing and analyzing low-level concentrations of 1,1-DCE as well as other aspects of their work on this project are provided as Appendix A.
The U.S. Environmental Protection Agency (EPA) through its Office of Research and Development (ORD), National Exposure Research Laboratory (NERL), is providing the information in this report as a result of funding received from the Regional Monitoring Initiative Program for applied research in support of the regional offices, especially Region 8, and in support of state programs, especially the Colorado Department of Public Health and Environment of the State of Colorado. A major portion of the report is the result of a work assignment under EPA Contract 68-D-00-206 to ManTech Environmental Technology, Inc. This report has been subjected to the Agency's peer and administrative review and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

PUBLISHED REPORT Guidelines for the Application of Sem/Edx Analytical Techniques for Fine and Coarse PM Samples 04/25/2003
Willis, R. D. AND T L. Conner. Guidelines for the Application of Sem/Edx Analytical Techniques for Fine and Coarse PM Samples. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-02/070 (NTIS PB2004-100988), 2003.
Abstract: Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive X-ray analysis (EDX) is a powerful tool in the characterization and source apportionment of environmental particulate matter (PM), providing size, chemistry, and morphology of particles as small as a few tenths of a micrometer. Such information can reveal information about emission sources which cannot be determined through bulk chemical analysis. Automated SEMs capable of routinely analyzing hundreds of particles per hour have dramatically increased the throughput of SEM/EDX, making it feasible to conduct statistically meaningful analyses of PM samples and to generate large data sets for source apportionment studies.
The National Exposure Research Laboratory (NERL) of the U.S. EPA has been developing and evaluating the use of SEM/EDX to characterize ambient and source-derived particles. The present document, which evolved over several years as a product of research carried out in support of the U.S. EPA/NERL SEM/EDX Laboratory, is intended to provide guidelines for researchers using SEM/EDX for aerosol characterization and source apportionment. Topics include laboratory procedures for sample handling, sample preparation, guidelines for successful manual and automated SEM/EDX analyses, data interpretation, issues relating to data quality and method validation and case studies highlighting the use of SEM/EDX in PM research.

The information in this document has been funded wholly by the United States Environmental Protection Agency under contract number 68D00206 to ManTech Environmental Technology, Inc. It has been subjected to the Agency's peer and administrative review and has been approved for publication as an EPA document.

PUBLISHED REPORT Status of Semi-Continuous Monitoring Instrumentation for Gas and Water Soluble Particle Components Needed for Diagnostic Testing of Ambient Air Quality Simulation Models 04/15/2003
McClenny, W A., K. G. Kronmiller, K. D. Oliver, H. H. Jacumin Jr., AND E. H. Daughtrey Jr. Status of Semi-Continuous Monitoring Instrumentation for Gas and Water Soluble Particle Components Needed for Diagnostic Testing of Ambient Air Quality Simulation Models. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-02/072 (NTIS PB2004-100894), 2003.
Abstract: This status report documents the effort by the National Exposure Research Laboratory (NERL), Office of Research and Development (ORD) of the U.S. Environmental Protection Agency (U.S. EPA) to provide methods of measurement, including calibration procedures, that meet the requirements for diagnostic testing of models describing atmospheric photochemistry. These requirements include a measurement uncertainty of ± 0.2 ppbv (± 0.1 for NO2) at 1.0 ppbv (or equivalent for particles) for compounds mentioned here as specified by scientists in the AMD, NERL. New developments for monitors of NO2, HCHO, H2O2, HNO3, HONO, NH3, volatile organic compounds (VOCs) (including n-aldehydes), particulate nitrate, particulate sulfate, and particulate ammonium are discussed in the report. Descriptions of instrument design and principle of operation for NO2, HCHO, and water soluble gases and particulate matter are presented.
Since field comparisons among different methods are often the accepted approach for identifying monitoring problems and establishing consensus among scientists specializing in monitoring methods, recent activities have emphasized field studies. Results from the 2002 Tampa, FL Bay Regional Atmospheric Chemistry Experiment (BRACE), the 2001 Philadelphia, PA, Northeast Ozone Particle Study (NE-O3PS) study, and the 1999 Nashville, TN Southern Oxidants Study (SOS) are shown. Of particular note are the preliminary results of field monitoring of NO2 in the BRACE field study with systems using new commercial photolytic converters for NO2 to NO conversion followed by chemiluminescence detection. In the NE-O3PS field study comparisons of HNO3, HONO, SO2, and nitrate and sulfate in particulate matter between the Harvard School of Public Health (HSPH) EPA Denuder System (HEADS) (10-h average) and the average response from the Texas Tech University (TTU) semi-continuous system (15 min updates) provide an interesting (an so far unresolved) example of a multiplicative error in a field study database. Current plans call for a more definitive statistical comparison of methods using the existing field monitoring database in the NE-O3PS and BRACE studies and additional field comparisons of methods in the upcoming 2003 Seattle field study.

The U.S. Environmental Protection Agency through its Office of Research and Development assembled the information in this report with input from a number of prominent scientists and funded a research effort to provide field data for this report under contract 68-D-00-206 to ManTech Environmental Technology, Inc. The report has been subjected to the Agency's peer and administrative review and has been approved for publication as an EPA document. Mention of trade names or commercial products does not constitute endorsement for use.



UNPUBLISHED REPORT Ctepp Standard Operating Procedure for Extracting and Preparing Liquid Food Samples for Analysis of Persistent Organic Pollutants (Sop-5.19) 01/09/2003
Ctepp Standard Operating Procedure for Extracting and Preparing Liquid Food Samples for Analysis of Persistent Organic Pollutants (Sop-5.19).
Abstract: This SOP describes the procedures for homogenizing, extracting, and concentrating liquid food samples for neutral persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and phenols.

UNPUBLISHED REPORT Ctepp Standard Operating Procedure for Extracting and Preparing Solid Food Samples for Analysis of Persistent Organic Pollutants (Sop-5.20) 01/09/2003
Ctepp Standard Operating Procedure for Extracting and Preparing Solid Food Samples for Analysis of Persistent Organic Pollutants (Sop-5.20).
Abstract: This SOP describes the procedures for homogenizing, extracting and concentrating solid food samples for persistent organic pollutants such as organochlorine compounds, organophosphate compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, substituted phenols, and pthalates.

 

ORD Home | Search EPA | Search NERL | Search EIMS | Contacts | Help

 
Begin Site Footer

EPA Home | Privacy and Security Notice | Contact Us

Last Updated on Wednesday, March 04, 2009
URL: http://cfpub.epa.gov