2003 Progress Report: Personal PM Exposure Assessment

EPA Grant Number: R827355C003
Subproject: this is subproject number 003 , established and managed by the Center Director under grant R827355
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Airborne PM - Northwest Research Center for Particulate Air Pollution and Health
Center Director: Koenig, Jane Q.
Title: Personal PM Exposure Assessment
Investigators: Liu, Sally , Claiborn, Candis , Larson, Timothy V.
Current Investigators: Liu, Sally , Allen, Ryan , Claiborn, Candis , Kalman, Dave , Koenig, Jane Q. , Larson, Timothy V. , Simpson, Chris
Institution: University of Washington
EPA Project Officer: Chung, Serena
Project Period: June 1, 1999 through May 31, 2004 (Extended to May 31, 2006)
Project Period Covered by this Report: June 1, 2003 through May 31, 2004
Project Amount: Refer to main center abstract for funding details.
RFA: Airborne Particulate Matter (PM) Centers (1999) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Particulate Matter , Air


The objectives of this research project are to: (1) characterize the key factors influencing this relationship and develop models for predicting personal PM exposures; and (2) provide exposure models for the concurrent epidemiologic study to reach an unbiased estimation of health effects.

Progress Summary:

Exposure Modeling

We adapted a recursive mass balance model to quantify outdoor-originated particulate matter (PM) entering indoor environments. Nonlinear regression was used to predict particle infiltration ( Finf, 0.65 ± 0.21) for 44 residences monitored as part of the Seattle panel study. Finf differed significantly by season. The Finf estimates agreed well with those estimated from the sulfur-tracer method (R2 = 0.78) and also showed robust and expected behavior when compared against known influences. Among our study residences, outdoor-generated particles accounted for an average of 79 ± 17 percent of the indoor PM concentration, with a range of 40 to 100 percent at individual residences.

The Finf estimates then were used in combination with time-location data from 38 subjects to estimate an ambient contribution fraction (α, mean = 0.66 ± 0.21) for each subject and to separate personal PM exposure into ambient and nonambient components. The mean α was significantly lower for subjects monitored during the heating season (0.55 ± 0.16) than during the nonheating season (0.80 ± 0.17). Our modeled α estimates agreed well with those estimated using the sulfur-tracer method (slope = 1.08; R2 = 0.67). Across all subjects, the average exposure encountered indoors at home was lower than in all other microenvironments. Cooking and being at school were associated with elevated levels of exposure. We modeled exposure to ambient and nonambient PM using both continuous light scattering and 24-hour gravimetric data and found good agreement between the two methods. On average, ambient particles accounted for 48 percent of the total personal exposure (range: 21-80 %). The personal activity exposure was influenced highly by time spent away from monitored microenvironments. Although both α and the nonambient sources influenced the personal-central relationship, the latter seemed to dominate. The recursive modeling results have been used in Project 2a for assessment of exhaled nitric oxide (eNO) and lung function effects.

Diesel Bus Pilot Study

The Diesel Bus Pilot Study assessed the exposures of nine asthmatic and nonasthmatic children in Seattle as they rode to and from school in a variety of makes and models of diesel school buses, including one equipped with an oxidative catalyst to reduce its emissions. We evaluated the portable instruments against standard equipment in a controlled environmental chamber and used these instruments to quantify the children’s exposures to the following parameters: fine and ultrafine particles, trace elements, elemental carbon and organic carbon, sulfur dioxide, oxides of nitrogen, and carbon monoxide. We also tested acute effects of their diesel exhaust exposures. Subjects performed several respiratory health measurements, including: exhaled breath condensate (EBC), eNO, and spirometry. This pilot study demonstrated the feasibility of performing a multiyear study, which aims to document the change in children’s exposure to several of the primary constituents of diesel exhaust as older school buses in the Puget Sound region are retrofitted with emission control technologies or replaced by newer clean-burning buses over the next several years.

Agriculture Burning Study

We have completed the Agriculture Burning Study in Pullman, WA, and presented the results to the Washington Department of Ecology’s Expert Panel. We prepared presentations for public meetings held in early June 2004 and are preparing manuscripts from this study. In the Agriculture Burning Study, we found that the PM2.5 concentrations at nighttime were significantly higher than at daytime. A similar trend also was observed for the levoglucosan (LG), suggesting that most episodes occurred at nighttime. A four-source Positive Matrix Factorization model was applied to the chemical speciation data. It was estimated that 18 percent of the PM2.5 mass concentration was from vegetative burning. A spatial model (R2 = 0.66) was built to estimate the PM2.5 concentrations at home outdoors. It was found that although the central site PM2.5 levels, elevation, and temperature were significant predictors, the distance from home sites to the central site was not. The Finf estimated from the recursive model had a mean of 0.60 and standard deviation of 0.15. A microenvironmental model combined with the time-location-activity information and chemical mass balance modeling results was developed to estimate the personal PM exposures resulting from agriculture burning (Eab). The R2 value between the personal LG and the estimated Eab is 0.45.

To determine whether wheat field burning has pulmonary effects in individuals with asthma, we paired 602 laboratory measures of online eNO and 585 coached spirometry measures in 33 individuals to measurements of fine particulate air pollution (PM2.5) from a central location during the field-burning season (September-October 2002) in Pullman, WA. We hypothesized that adults with mild-moderate asthma who were not using anti-inflammatory medication would show a positive association of eNO and negative association of forced expiratory volume in one second (FEV1) and maximum midexpiratory flow (MMEF) with the peak 1-hour average of PM2.5 during the previous 24 hours. To determine these associations, we used a Generalized Estimating Equation model that included fixed covariates for gender, age, body mass index, an interaction term between medication use and exposure and adjusted for temperature and relative humidity.

Results. The 33 participants ranged in age from 18-52 years (median 24 years), and 64 percent were female. Eleven individuals were prescribed asthma medications and 3 individuals had baseline FEV 1 less than 80 percent of predicted. The range of measured PM2.5 was 4-60 μg/m3 with four field-burning episodes characterized by less than or equal to five (30-minute average) PM2.5 concentrations greater than 40 μg/m3 during a 24-hour period. There was no significant effect of peak 1-hour PM2.5 on measures of eNO among those not prescribed anti-inflammatory medications: 0.26 ppb increase per 10 µg/m3 (95 % confidence interval [CI]: -1.45, 1.96) or those prescribed controller medications: 1.83 ppb increase per 10 µg/m3 (95 % CI: -1.36, 5.02). Similar null effects of peak PM2.5 exposure were noted for spirometric measures of MMEF and FEV 1. We did not find an association between peak PM2.5 episodes from field burning and decrements in pulmonary function nor increases in pulmonary inflammation measured by eNO in individuals with or without asthma medication use.

Future Activities:

We will: (1) investigate uncertainties in the recursive model approach; (2) develop models to estimate susceptible populations’ exposure to PM from combustion sources; and (3) gain a preliminary understanding of school children’s exposure to diesel exhaust particles (DEP) and related health effects.

Through our exposure characterization work and manuscripts, we expect to provide a better understanding of infiltration efficiency and exposures to ambient-originated PM of different sizes, constituents, and sources across three major cities. We will further our understanding of combustion- related PM exposures, especially among susceptible subpopulations.

We also will prepare a manuscript to describe the range of DEP exposures and health outcomes in school children riding different types of diesel school buses in the Puget Sound area. Health outcomes (such as eNO and oxidative stress markers in EBC) from this fieldwork may be compared with those to be measured in the exposure chamber facilities (Kaufman 2002 Science To Achieve Results grant).

Journal Articles on this Report : 4 Displayed | Download in RIS Format

Other subproject views: All 65 publications 25 publications in selected types All 25 journal articles
Other center views: All 209 publications 113 publications in selected types All 109 journal articles
Type Citation Sub Project Document Sources
Journal Article Allen R, Larson T, Sheppard L, Wallace L, Liu L-JS. Use of real-time light scattering data to estimate the contribution of infiltrated and indoor-generated particles to indoor air. Environmental Science & Technology 2003;37(16):3484-3492. R827355 (2004)
R827355 (Final)
R827355C003 (2003)
R827355C003 (Final)
R827355C008 (Final)
R827355C009 (2003)
  • Abstract from PubMed
  • Full-text: ResearchGate - Abstract & Full Text PDF
  • Abstract: ACS-Abstract
  • Other: ACS-Full Text PDF
  • Journal Article Allen R, Wallace L, Larson T, Sheppard L, Liu L-JS. Estimated hourly personal exposures to ambient and nonambient particulate matter among sensitive populations in Seattle, Washington. Journal of the Air & Waste Management Association 2004;54(9):1197-1211. R827355 (2004)
    R827355 (Final)
    R827355C003 (2003)
    R827355C003 (2004)
    R827355C003 (Final)
    R827355C008 (Final)
    R827355C009 (Final)
  • Abstract from PubMed
  • Full-text: Taylor&Francis-Full Text PDF
  • Abstract: Taylor&Francis-Abstract
  • Other: ResearchGate - Abstract & Full Text PDF
  • Journal Article Delfino RJ, Quintana PJE, Floro J, Gastanaga VM, Samimi BS, Kleinman MT, Liu L-JS, Bufalino C, Wu C-F, McLaren CE. Association of FEV1 in asthmatic children with personal and microenvironmental exposure to airborne particulate matter. Environmental Health Perspectives 2004;112(8):932-941. R827355 (2004)
    R827355 (Final)
    R827355C003 (2003)
    R827355C003 (2004)
    R827355C003 (Final)
  • Full-text from PubMed
  • Abstract from PubMed
  • Associated PubMed link
  • Full-text: ResearchGate-Abstract & Full Text PDF
  • Abstract: EHP-Abstract and Full Text HTML
  • Other: EHP-Full Text PDF
  • Journal Article Wu C-F, Delfino RJ, Floro JN, Samimi BS, Quintana PJE, Kleinman MT, Liu L-JS. Evaluation and quality control of personal nephelometers in indoor, outdoor and personal environments. Journal of Exposure Analysis and Environmental Epidemiology 2005;15(1):99-110. R827355 (Final)
    R827355C003 (2003)
    R827355C003 (Final)
  • Abstract from PubMed
  • Full-text: NATURE-Full Text PDF
  • Abstract: NATURE-Abstract & Full Text HTML
  • Other: ResearchGate - Abstract & Full Text PDF
  • Supplemental Keywords:

    ambient particles, fine particles, combustion, health, exposure, biostatistics, susceptibility, human susceptibility, sensitive populations, air toxics, genetic susceptibility, indoor air, indoor air quality, indoor environment, tropospheric ozone, California, CA, polyaromatic hydrocarbons, PAHs, hydrocarbons, acute cardiovascular effects, aerosols, air pollutants, air pollution, air quality, airborne pollutants, airway disease, airway inflammation, allergen, ambient aerosol, ambient aerosol particles, ambient air, ambient air quality, ambient particle health effects, animal model, assessment of exposure, asthma, atmospheric aerosols, atmospheric chemistry, biological markers, biological response, cardiopulmonary response, cardiovascular disease, children, children’s vulnerability, combustion, combustion contaminants, combustion emissions, epidemiology, exposure, exposure and effects, exposure assessment, harmful environmental agents, hazardous air pollutants, health effects, health risks, human exposure, human health effects, human health risk, incineration, inhalation, lead, morbidity, mortality, mortality studies, particle exposure, particle transport, particulates, particulate matter, risk assessment,, RFA, Health, Scientific Discipline, Air, Geographic Area, particulate matter, air toxics, Environmental Chemistry, Health Risk Assessment, Epidemiology, State, Northwest, Risk Assessments, Susceptibility/Sensitive Population/Genetic Susceptibility, Biochemistry, genetic susceptability, indoor air, Atmospheric Sciences, ambient aerosol, ambient air quality, asthma, biostatistics, health effects, particulates, PM10, sensitive populations, air pollutants, cardiopulmonary responses, fine particles, health risks, human health effects, morbidity, PM 2.5, toxicology, stratospheric ozone, exposure and effects, ambient air, exposure, hazardous air pollutants, animal model, combustion emissions, air pollution, children, Human Health Risk Assessment, particle exposure, cardiopulmonary response, human exposure, inhalation, PAHs, atmospheric aerosols, ambient particle health effects, mortality studies, hydrocarbons, human susceptibility, Seattle, Washington, incineration, indoor air quality, mortality, California (CA), allergens, aerosols, air quality, atmospheric chemistry, cardiovascular disease, exposure assessment, human health risk

    Relevant Websites:

    http://depts.washington.edu/pmcenter/ Exit

    Progress and Final Reports:

    Original Abstract
  • 1999 Progress Report
  • 2000 Progress Report
  • 2001 Progress Report
  • 2002 Progress Report
  • 2004 Progress Report
  • Final Report

  • Main Center Abstract and Reports:

    R827355    Airborne PM - Northwest Research Center for Particulate Air Pollution and Health

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R827355C001 Epidemiologic Study of Particulate Matter and Cardiopulmonary Mortality
    R827355C002 Health Effects
    R827355C003 Personal PM Exposure Assessment
    R827355C004 Characterization of Fine Particulate Matter
    R827355C005 Mechanisms of Toxicity of Particulate Matter Using Transgenic Mouse Strains
    R827355C006 Toxicology Project -- Controlled Exposure Facility
    R827355C007 Health Effects Research Core
    R827355C008 Exposure Core
    R827355C009 Statistics and Data Core
    R827355C010 Biomarker Core
    R827355C011 Oxidation Stress Makers