PERSONAL EXPOSURE TO AIRBORNE PARTICLES AND METALS - RESULTS FROM THEPARTICLE TEAM STUDY IN RIVERSIDE, CALIFORNIA

The PTEAM Study was the first large-scale probability-based study of p ersonal exposure to particles. Sponsored by the U.S. Environmental Pro tection Agency (EPA) and the Air Resources Board of California, it was carried out by the Research Triangle Institute (RTI) and the Harvard University School of Public Health (HSPH). HSPH designed and construct ed a 4-lpm, battery-operated personal monitor for inhalable particles (PM(10)) that could be wont comfortably for up to 14 hours by persons from 10 to 70 years old. The monitor was worn for two consecutive 12-h our periods (day and night) during the fall of 1990 by 178 participant s representing 139,000 nonsmoking residents of Riverside, California. Nearly identical monitors were employed to collect concurrent indoor a nd outdoor samples. The monitors were equipped with a different sampli ng nozzle to collect fine particles (PM(2.5)). Population-weighted day time personal PM(10) exposures averaged 150 +/- 9 (SE) mu g/m(3), comp ared to concurrent indoor and outdoor concentrations of 95 +/- 6 mu g/ m(3). This suggested the existence of excess mass near the person, a ' 'personal cloud'' that appeared related to personal activities. Fourte en of 15 prevalent elements also were elevated in the personal samples . The two major indoor sources of indoor particles were smoking and co oking; even in these homes, however, more than half of the indoor part icles came from outdoors, and a substantial portion of the indoor part icles were of undetermined indoor origin.Outdoor concentrations near t he homes were well correlated with outdoor concentrations at the centr al site, supporting the idea of using the central site as an indicator of ambient concentrations over a wider area. Indoor concentrations we re only weakly correlated with outdoor concentrations, however, and pe rsonal exposures were even more poorly correlated with outdoor concent rations. Elemental profiles were obtained for environmental tobacco sm oke (ETS) (major contributions from potassium and chlorine) and cookin g emissions (aluminum, iron, calcium, and chlorine). These profiles ca n be used in future source apportionment studies.