title: Air Pollution Exposure Model for Individuals (EMI) in Health Studies: Evaluation for Ambient PM2.5 in Central North Carolina.
abstract: Air pollution health studies of fine particulate matter (diameter ≤2.5 μm, PM2.5) often use outdoor concentrations as exposure surrogates. Failure to account for variability of indoor infiltration of ambient PM2.5 and time indoors can induce exposure errors. We developed and evaluated an exposure model for individuals (EMI), which predicts five tiers of individual-level exposure metrics for ambient PM2.5 using outdoor concentrations, questionnaires, weather, and time-location information. We linked a mechanistic air exchange rate (AER) model to a mass-balance PM2.5 infiltration model to predict residential AER (Tier 1), infiltration factors (Tier 2), indoor concentrations (Tier 3), personal exposure factors (Tier 4), and personal exposures (Tier 5) for ambient PM2.5. Using cross-validation, individual predictions were compared to 591 daily measurements from 31 homes (Tiers 1-3) and participants (Tiers 4-5) in central North Carolina. Median absolute differences were 39% (0.17 h(-1)) for Tier 1, 18% (0.10) for Tier 2, 20% (2.0 μg/m(3)) for Tier 3, 18% (0.10) for Tier 4, and 20% (1.8 μg/m(3)) for Tier 5. The capability of EMI could help reduce the uncertainty of ambient PM2.5 exposure metrics used in health studies.
authors.affiliation: National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Breen
authors.affiliation: National Center for Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Long
authors.affiliation: U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Schultz
authors.affiliation: National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
authors.forename: Ronald W
authors.initials: RW
authors.lastname: Williams
authors.affiliation: National Center for Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Richmond-Bryant
authors.affiliation: Biomathematics Program, Department of Mathematics, North Carolina State University , Raleigh, North Carolina 27695, United States.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Breen
authors.affiliation: Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
authors.forename: John E
authors.initials: JE
authors.lastname: Langstaff
authors.affiliation: National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
authors.forename: Robert B
authors.initials: RB
authors.lastname: Devlin
authors.affiliation: Helmholtz Zentrum Muenchen, German Research Center for Environmental Health, Institute of Epidemiology II , Neuherberg, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Schneider
authors.affiliation: National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27709, United States.
authors.forename: Janet M
authors.initials: JM
authors.lastname: Burke
authors.affiliation: Environmental Health Sciences, University of Michigan , Ann Arbor, Michigan 48109, United States.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Batterman
authors.affiliation: Department of Environmental Sciences, Rutgers University , New Brunswick, New Jersey 08901, United States.
authors.forename: Qing Yu
authors.initials: QY
authors.lastname: Meng
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis; D000397:Air Pollution / Q000032:analysis; D016902:Air Pollution, Indoor / Q000009:adverse effects / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006798:Housing; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D009657:North Carolina; D052638:Particulate Matter / Q000009:adverse effects / Q000032:analysis; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013997:Time Factors; D014887:Weather
chemical_list: D000393:Air Pollutants; D052638:Particulate Matter