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PRELIMINARY FINDINGS ON THE ASSESSMENT OF POTENTIAL CAR-RELATED OCCUPATIONAL PM AND AIR TOXIC EXPOSURE TO PATROL TROOPERS (COPP STUDY)
Citation:
Williams, R W., M Riediker, L S. Sheldon, R B. Devlin, T. R. Griggs, C Stevens, J D. Pleil, S. McCorquodale, AND B. R. Appel. PRELIMINARY FINDINGS ON THE ASSESSMENT OF POTENTIAL CAR-RELATED OCCUPATIONAL PM AND AIR TOXIC EXPOSURE TO PATROL TROOPERS (COPP STUDY). Presented at International Society of Exposure Analysis 2002 Conference, Vancouver, Canada, August 11-15, 2002.
Impact/Purpose:
The overall goal of human exposure research in air toxics is to develop the methods, data, and models of exposure that will provide the scientific basis for EPA to move to a risk-based program and that will enhance NATA. Specific objectives for this measurement task are to:
o Characterize exposure concentrations and variability in critical microenvironments using targeted measurement studies;
o Quantify the relationship of personal exposure to ambient and indoor concentrations;
o Identify critical microenvironments, human activities, and factors influencing exposure to air toxics;
o Develop methods to quantify exposure from background, point or area sources, and microenvironmental sources;
o Evaluate aggregate and cumulative exposures.
Description:
In-vehicle, roadside and community-based measurements of particulate matter (PM) and select air toxics were measured as part of a study involving patrol cars from the North Carolina Highway Patrol. One goal of this study was to characterize PM and related air pollutant concentrations associated with vehicle operations in and around Wake County, North Carolina during the patrol officers' normal 8-hr duty schedule. We also assessed the magnitude and variability of selected air pollutants and their temporal/spatial relationships. The study design consisted of repeated daily measurements of PM2.5, volatile organic carbon (VOCs), polynuclear aromatic hydrocarbons (PAHs), elemental carbon (EC), aldehydes, carbon monoxide, nitrogen oxides and ozone mass concentrations. PM2.5, PAH, and CO were measured in real-time while the others were integrated samples. A total of 50 monitoring days involving vehicles from 10 participating patrol officers were performed between August 16th and October 4th 2001. Preliminary data analyses from in-vehicle trials indicate a mean real-time PM2.5 mass concentration of 24 ug/m3 with a range of 4 to 54 ug/m3 (7 to 59 ug/m3 using collocated impactor filter-based monitors). Concentrations of PAHs made up of three to five ring structures ranged from 7 to 64 ng/m3 (mean = 21 ng/m3). CO levels averaged 2.6 ppm with the maximum observed 8-hr concentration < 6 ppm. A majority of the 15 selected vehicular emission-related carbonyls were determined to be at detectable concentrations in most of the trials. This included compounds such as formaldehyde, acetaldehyde and acetone. These three carbonyls typically had in-vehicle concentrations of 10 to 20 ug/m3. Time series examples of other in-vehicle real-time data collections will be presented. An investigation of potential linkages between exposure findings and select health effects in the participants, such as lung function and heart rate, was also performed as a component of this study and will be presented in an accompanying abstract.
This work has been funded by the United States Environmental Protection Agency under cooperative agreement # CR-824915 to the University of North Carolina-Chapel Hill, and contract 68-D-00-206 to ManTech Environmental Technology, by the North Carolina State Highway Patrol, and by the Swiss National Science Foundation. It has been subjected to Agency review and approved for publication but does not necessarily reflect EPA policy.