Grantee Research Project Results
2000 Progress Report: Relationship Between PM2.5 Semi-volatile Organic Material, Other PM2.5 Components and Heart Rate Variability in The Elderly
EPA Grant Number: R827993Title: Relationship Between PM2.5 Semi-volatile Organic Material, Other PM2.5 Components and Heart Rate Variability in The Elderly
Investigators: Eatough, Delbert J. , Pope, Clive Arden
Institution: Brigham Young University
EPA Project Officer: Chung, Serena
Project Period: February 1, 2000 through January 31, 2003
Project Period Covered by this Report: February 1, 2000 through January 31, 2001
Project Amount: $797,013
RFA: Airborne Particulate Matter Health Effects (1999) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air , Human Health
Objective:
The objectives of the research project are to:(1) evaluate the usefulness of a newly developed, real-time, continuous monitor (RAMS) for total (nonvolatile plus semi-volatile) PM2.5 mass, particularly the time and health relevance of this method, as compared to other measurements of PM2.5 parameters;
(2) intercompare a variety of batch (24-hour) and continuous (1-hour) PM2.5 measurement methods, including equilibrated mass (FRM), nonvolatile mass (TEOM), total mass (RAMS, the new method), particulate carbon (R&P monitor), soot (Anderson Aethalometer), and particle number. The sums of 24 hourly mass measurements also are being compared to mass measured by 24-hour filter collections and PC-BOSS results;
(3) determine the health-relevance of the various PM2.5 measurements by correlation with health measures;
(4) identify, where possible, PM2.5 components associated with the exacerbation of cardiovascular health problems; and
(5) identify monitoring paradigms that optimize health- and time-relevant monitoring strategies for PM2.5. Monitoring for the Salt Lake City EMPACT Program was initiated in December 1999, and additional sampling was initiated for the STAR program in July 2000.
Progress Summary:
Salt Lake City
The EPA STAR/EMPACT monitoring site is located immediately adjacent to the State of Utah Air Quality Monitoring site at the Hawthorne Elementary School in Salt Lake City. The site is in a residential area about 4 km southwest of the central business district. The population in Salt Lake Valley where the site is located is about .75 million. PM2.5 pollution at the site is expected to be dominated by primary emissions and secondary products from mobile source emissions and, during the winter, wood smoke from home combustion. During the summer of 2000, the site also was impacted by emissions from forest fires in the Wasatch Mountains. There are no major point sources that are expected to make a significant impact at the Hawthorne site. Data have been collected at the site since December 1999. The following PM sampling methods are being used at the Salt Lake City site.
1. Continuous Sampling Methods
RAMS. The Real-time total Ambient Mass Sampler (RAMS), based on diffusion denuder, Nafion dryer, and TEOM monitor technology, is the state-of-the-art sampler being used for the real-time determination of total PM2.5 mass, including semi-volatile species (Eatough, 2000; Modey, 2001). The RAMS measures total PM2.5 mass with a TEOM monitor using a "sandwich" filter to retain SVC, which would be lost from particles in a conventional TEOM monitor. The sandwich filter consists of a Teflon-coated particle collection filter (R&P TX40), followed by a recently developed charcoal-impregnated glass fiber filter (CIG, Schleicher and Schuell) to collect any semi-volatile compounds lost from the particles during sampling. Care must be taken to remove from the sample stream all gas phase species that can be absorbed by the CIG filter to prevent overdetermination of PM2.5 mass.
The RAMS has a dual inlet system consisting of a 2.5 mm cut-point cyclone inlet followed by a particle concentrator. A BOSS diffusion denuder, packed with 15, 25-cm long, parallel charcoal-impregnated cellulose fiber (CIF) strips, serves to remove gas phase organic and other species. Gas-phase species such as NO2 and O3 are removed by a series of triethanolamine coated multi-annular denuders. Gas-phase water is removed by a series of two, 1-foot long, 200-element Nafion Dryers, located before and after the BOSS and annular denuders. To correct for any gas phase species not removed by the denuders and dryers but absorbed by the sandwich filter, a second system similar to the one described above is employed. A quartz filter is placed immediately after the first Nafion Dryer on the second system to remove all particles. The second system is then used as a blank to correct the data obtained with the RAMS. Total PM2.5 data are being collected on a 1-hour basis with the RAMS. These data are being compared with the 1-hour averaged nonvolatile PM2.5 data obtained with the TEOM monitor. One-hour RAMS data also are being averaged over 4-, 6-, and 24-hour periods for comparison with mass data obtained from the PC-BOSS.
R&P TEOM Monitor. The TEOM Monitor is a microbalance that determines mass continuously on a heated filter. As stated in the overview, semi-volatile PM will evaporate at the standard operating temperature of the instrument (50oC, which is required to remove particle-bound water). This technique measures only nonvolatile PM. One-hour-averaged, nonvolatile PM2.5 mass concentrations are being determined using an R&P TEOM monitor operating under normal conditions.
TSI CPC Monitor. A TSI monitor for the determination of condensation
nuclei and their size distribution is being used to determine total fine
particle number. Total particle number will be dominated by ultrafine particles
(<100 nm). This instrument is a real-time monitor; therefore, data are being
averaged over 1-hour periods throughout the 2-year sampling
program.
R&P Series 5400 Ambient Carbon Particulate Monitor.
The Series 5400 Ambient Carbon Particulate Monitor from Rupprecht and Patashnick
is being used to characterize the carbon content of suspended particles on a
continuous basis. The Series 5400 performs a thermal-CO2 analysis to determine
the amount of organic and elemental carbon (soot) present in a collected sample.
During the analysis phase, the collected sample is first heated to 375oC and
then to
750oC to determine the concentrations of "organic" and "elemental
carbon," respectively. One- hour carbon concentration averages are being
obtained, enabling comparison with the 1-hour averaged TEOM and RAMS data.
Anderson Aethalometer. An Anderson Instruments, Inc. (Model RTAA-900) Aethalometer is used for the determination of aerosol elemental carbon (soot) on a continuous basis. One-hour average elemental-carbon (soot) concentrations are obtained and compared with the 1-hour averaged TEOM and RAMS data.
2. Chemical Composition Samplers
PC-BOSS. The combination of technology used in the High-Volume Brigham Young University Organic Sampling System (BIG BOSS) and the Harvard particle concentrator has resulted in the Particle Concentrator-Brigham Young University Organic Sampling System. This is the state-of-the-art sampler being used to determine particulate composition in the EPA STAR program (Long, 2001).
The PC-BOSS is being used for sample collection to determine fine particulate mass, trace elements, sulfate, acidity, carbonaceous material (elemental and organic), nitrate, semi-volatile organic material, and semi-volatile nitrate. Samples for the chemical characterization of PM2.5 in the minor flow following a particle concentrator and a BOSS diffusion denuder are collected in a filter pack containing a prefired 47-mm quartz filter (Pallflex), followed by a newly developed charcoal-impregnated glass fiber filter (CIG, Schleicher and Schuell) to determine fine particulate carbonaceous material and nitrate, including semi-volatile species lost from the particles during sampling. A second parallel filter pack containing a 47-mm Teflon (Whatman) filter followed by a 47-mm Nylon (Gelman, Nylasorb) filter is used to determine PM2.5 mass, sulfate, and nitrate, including any nitrate lost from the particles during sample collection. In addition to the daily 24-hour sample collection, intensive studies have been performed during winter, week-long episodes. During nonepisode periods, 24-hour samples are being collected each day for comparison with equilibrated PM2.5 mass concentrations measured on a 24-hour basis by the PM2.5 FRM.
PM2.5 FRM. The FRM is the method used by EPA to determine fine particulate mass in the atmosphere. The FRM collects particles on a single filter in a temperature-controlled environment. Collected mass is determined gravimetrically. The FRM data are being obtained by the State of Utah Division of Air Quality.
Bountiful and Lindon Sites
The EPA STAR Bountiful monitoring site is located immediately adjacent to the State of Utah Air Quality Monitoring site at the Bountiful Fire Station in downtown Bountiful. The Bountiful site is 20 km north of the Hawthorne site and is sheltered from direct transport of pollutants from the Hawthorne site by a range of mountains that extend from the main Wasatch Mountains out into the valley between the two sites. The population in the Bountiful area is about 100,000. The region has no major business center such as exists in Salt Lake City, but is a major commuter traffic feed to the Salt Lake City area. Immediately to the west of Bountiful are a series of oil refineries. Bountiful is expected to be impacted by mobile source emissions, wood smoke emissions, and emissions from these refineries during transport from the west.
The EPA STAR Lindon monitoring site is located immediately adjacent to the State of Utah Air Quality Monitoring site at the Lindon Elementary School. The Lindon site is 50 km south of the Hawthorne site and also is sheltered from direct transport of pollutants from the Hawthorne site by a range of mountains that extends from the main Wasatch Mountains out into the valley between the two sites. The population near the Lindon area includes Provo and Orem, with a combined population of about 300,000. The Lindon region has no major business center, but is a major commuter traffic feed to the Provo area. Immediately to the west of Lindon is an integrated steel mill. The site is located such that impacts from the steel mill are expected. Lindon is expected to be impacted by mobile source emissions, wood smoke emissions, and emissions from the integrated steel mill, including blast furnace and coke oven emissions.
The samplers used at both Lindon and Bountiful are described above. Samplers at the two sites included the RAMS, TEOM, Aethalometer, CNC Counter, and PC-BOSS.
The results obtained by the RAMS for the continuous determination of PM2.5 mass, including semi-volatile particulate material, were averaged (24-hour) over the periods where PC-BOSS data are obtained. These results were validated by comparison with results obtained from the PC-BOSS sampler over the same time period. Integrated PC-BOSS samples were used to determine the mass of PM2.5 retained on a filter including semi-volatile nitrate and organic material lost from the filter during sampling. PC-BOSS sulfate and nitrate were present as ammonium sulfate and ammonium nitrate, respectively. Fine particulate organic material was taken to be 61 percent carbon. Crustal material was estimated from PIXE results. Constructed mass was obtained for each PC-BOSS sample as the sum of estimated crustal material; ammonium sulfate obtained from the Teflon filters; the ammonium nitrate from the Teflon filters; the volatile ammonium nitrate from the nylon filters; the soot collected on the quartz filters; and the total organic carbonaceous material, which is the sum of the organic material on the quartz filter and the semi-volatile organic material lost from the particles during sampling but collected on the charcoal-impregnated glass fiber filter.
For all samples, the linear regression of RAMS measured versus PC-BOSS constructed PM2.5 mass results gives r2 = 0.99, a slope of 0.98?0.05, and a of ?10% or ?1.5 g/m3. Results obtained with the RAMS and the PC-BOSS show that PM2.5 mass, including semi-volatile species, can be continuously and accurately monitored at the EPA STAR sampling sites in Salt Lake City, Bountiful, and Lindon with the RAMS (Long, 2000 and 2001).
The results obtained with the continuous samples in the study are illustrated by the 1-hour average RAMS and TEOM monitor results obtained during a 10-day period in the winter of 2000-2001 in Bountiful and Hawthorne and given in Figures 1A and B, respectively; and for a 14-day period at Hawthorne during the summer of 2000 when the site was impacted by emissions from forest fires, given in Figure 1C. As indicated in this figure, both for the time periods when an inversion or the forest fire emissions were present and days when a frontal passage resulted in substantially lower PM concentrations, the RAMS PM2.5 mass measurements generally are equal to or greater than the TEOM PM2.5 mass measurements. The fraction of PM2.5 not measured by the TEOM averaged 33 percent over these time periods. The higher RAMS PM2.5 mass, compared to that of the TEOM monitor, can be attributed to the presence of semi-volatile PM, which is measured by the RAMS but not by the TEOM.
Figure 1. One-hour average RAMS (total PM2.5) and TEOM monitor (nonvolatile PM2.5) results during December 28 , 2000, through January 5, 2001, at the Bountiful (A) and Hawthorne (B) sampling sites and at Hawthorne from July 23 through August 5 , 2000, at Hawthorne (C). The difference between the two measurements is semi-volatile material (SVM) lost from the heated (50 C) filter of the TEOM.
The RAMS PM2.5 mass measurements generally are equal to
or greater than the TEOM PM2.5 mass measurements. The
fraction of PM2.5 not measured by the TEOM has averaged 35
percent over the study period. The higher RAMS PM2.5 mass,
compared to that of the TEOM monitor, can be attributed to the presence of
semi-volatile PM, which is measured by the RAMS but not by the TEOM. The PM2.5 FRM sampler has lower losses than does the TEOM. The fraction
of PM2.5 not measured by the FRM is low in the winter and
high in the summer and has averaged
16 percent over the study period.
Future Activities:
Source apportionment analyses are being done to support the interpretation of the health data. Source apportionment has been done for PM2.5 data during a 10-day winter period with high PM2.5 concentrations due to winter inversions, and during a 14-day summer period when the site was impacted by smoke from wildfires in the Wasatch mountains (Eatough 2001) (see Figure 1). The PM2.5 was dominated by organic material and ammonium nitrate in the winter and by organic material in the summer. In both cases, substantial amounts of semi-volatile material (SVM) was present that was not measured by a TEOM monitor but was detected by a RAMS. The PM2.5 data have been combined with concentrations of particulate soot and soil corrected potassium, and with gas phase concentrations of NOx, CO, and SO2 to apportion the PM2.5 to primary emissions emitted by and secondary particulate material formed from emissions from mobile sources, oil refineries, and wood smoke combustion (including the forest fire emissions) on an hourly basis. Wood smoke and mobile source emissions dominated the contribution to the nonvolatile fraction of the PM2.5, with about equal contributions for each, but very different diurnal patterns for the two contributions. The diurnal patterns for the attribution were consistent with the emission patterns for these two sources. The SVM could not be directly attributed to any source, but appeared to be secondary ammonium nitrate and organic material formed from gaseous emissions of NOx and gas phase organic compounds from both mobile sources and wood smoke. This effort is being extended to include all time periods when human exposure data were obtained.The Salt Lake City EPA-BYU STAR and EMPACT study is examining the effects of particulate air pollution on cardiopulmonary health. These studies involve the evaluation of the association of daily measures of weather and particulate air pollution with day-to-day changes in heart rate (HR), heart rate variability (HRV), and markers of blood inflammation. The study is being conducted using panels of retired adults living close to the EMPACT monitoring site.
Many previous studies have found associations between episodes of air pollution and increases in heart attacks and deaths due to heart-related causes. However, there has been limited information about the mechanisms behind this association. Several recent studies, including studies conducted in Utah, have suggested that particulate air pollution can lower the human heart's ability to vary its speed, resulting in increased heart attacks and heart-related deaths.
A Holter monitor is worn for various 24-hour periods to provide continuous monitoring of heart rate and other key measures while going about daily activities. Multiple data set times are obtained during periods of low, moderate, and high pollution. At the end of each monitoring session, blood is drawn to assess inflammation. Data have been obtained with panels of about 20?30 participants during two winters and one summer study.
The data collected will allow the evaluation of evidence of changes in the heart's ability to respond to changes in activity, stress, or other factors. This will include looking for evidence of changes in blood measures, such as inflammation and various other blood-related factors that can affect the heart. Also, the monitoring of various constituents (including the source apportionment results) of the air pollution will allow for an evaluation of the components of air pollution that may be most important in terms of impacts on human health. Analysis and interpretation of the 1-hour average HRV data as compared to the 1-hour PM2.5 concentration, composition, and apportioned source results are under way.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other project views: | All 27 publications | 15 publications in selected types | All 15 journal articles |
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Type | Citation | ||
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Modey WK, Pang Y, Eatough NL, Eatough DJ. Fine particulate (PM2.5) composition in Atlanta, USA: assessment of the particle concentrator-Brigham Young University organic sampling system, PC-BOSS, during the EPA supersite study. Atmospheric Environment 2001;35(36):6493-6502. |
R827993 (2000) R827993 (2001) R827993 (2003) R827993 (Final) |
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Eatough DJ, Eatough NL, Obeidi F, Pang Y, Modey W, Long R. Continuous determination of PM2.5 mass, including semi-volatile species. Aerosol Science and Technology 2001;34(1):1-8. |
R827993 (2000) R827993 (2001) R827993 (Final) R825367 (Final) |
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Long RW, Smith R, Smith S, Eatough NL, Mangelson NF, Eatough DJ, Pope CA, Wilson WE. Sources of fine particulate material along the Wasatch Front. Energy & Fuels 2002;16(2):282-293. |
R827993 (2000) R827993 (2001) R827993 (2003) R827993 (Final) |
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Supplemental Keywords:
PM2.5, semi-volatile organic material, health effects, heart rate variability, blood inflammation., RFA, Scientific Discipline, Health, PHYSICAL ASPECTS, Air, particulate matter, Health Risk Assessment, air toxics, Susceptibility/Sensitive Population/Genetic Susceptibility, Risk Assessments, Biochemistry, Environmental Monitoring, Physical Processes, tropospheric ozone, genetic susceptability, ambient air quality, elderly adults, sensitive populations, cardiopulmonary responses, fine particles, human health effects, PM 2.5, semi-volatile organic material, stratospheric ozone, health risks, cardiovascular vulnerability, heart rate variability, ambient air, exposure, air pollution, chemical mixtures, chronic health effects, particulate exposure, human exposure, cardiopulmonary response, blood pressure, environmentally caused disease, highrisk groups, human susceptibility, mortality, Federal Reference Method, age dependent response, atmospheric chemistry, cardiac arrhythmias, transition metals, air quality, environmental hazard exposures, toxicsRelevant Websites:
http://www.empact.byu/Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.