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SPATIAL AND TEMPORAL VARIABILITY OF MOBILE SOURCE AIR TOXICS IN THE DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY
Citation:
VETTE, A. F., R. W. WILLIAMS, C. W. CROGHAN, AND D. A. WHITAKER. SPATIAL AND TEMPORAL VARIABILITY OF MOBILE SOURCE AIR TOXICS IN THE DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY. Presented at CRC Mobile Source Air Toxics Workshop, Phoenix, AZ, October 24 - 25, 2006.
Impact/Purpose:
Six objectives have been defined for this study.
(1) To determine the associations between concentrations measured at central site monitors and outdoor residential, indoor residential and personal exposures for selected air toxics, PM constituents, and PM from specific sources.
(2) To describe the physical and chemical factors that affect the relationship between central site monitors and outdoor residential and indoor residential concentrations, including those that affect ambient source impacts.
(3) To identify the human activity factors that influence personal exposures to selected PM constituents and air toxics.
(4) To improve and evaluate models used to characterize and estimate residential concentrations of and human exposures to selected air toxics, PM constituents, and PM from specific sources.
(5) To investigate and apply source apportionment models to evaluate the relationships for PM from specific sources and to determine the contribution of specific ambient sources to residential concentrations and personal exposures to PM constituents and air toxics.
(6) To determine the associations between ambient concentrations of criteria gases (O3, NO2, and SO2) and personal exposures for these gases as well as personal exposures to air toxics, PM constituents, and PM from specific sources.
Description:
Data from the first two years of the Detroit Exposure and Aerosol Research Study (DEARS) were evaluated to determine spatial and temporal characteristics in concentrations of mobile source air toxics (MSATs). Outdoor concentrations of MSATs were significantly higher in samples collected downwind from and in close proximity to roadways. MSATs measured outdoors in urban neighborhood sites were significantly higher than regional concentrations and at a state operated central community monitoring location indicating significant spatial variation in MSAT concentrations throughout the airshed.