Assessment of personal and community-level exposures to particulate matter among children with asthma in Detroit, Michigan, as part of Community Action Against Asthma (CAAA)

We report on the research conducted by the Community Action Against Asthma (CAAA) in Detroit, Michigan, to evaluate personal and community-level exposures to particulate matter (PM) among children with asthma living in an urban environment. CAAA is a community-based participatory research collaboration among academia, health agencies, and community-based organizations. CAAA investigates the effects of environmental exposures on the residents of Detroit through a participatory process that engages participants from the affected communities in all aspects of the design and conduct of the research; disseminates the results to all parties involved; and uses the research results to design, in collaboration with all partners, interventions to reduce the identified environmental exposures. The CAAA PM exposure assessment includes four seasonal measurement campaigns each year that are conducted for a 2-week duration each season. In each seasonal measurement period, daily ambient measurements of PM2.5 and PM10 (particulate matter with a mass median aerodynamic diameter less than 2.5 mum and 10 mum, respectively) are collected at two elementary schools in the eastside and southwest communities of Detroit. Concurrently, indoor measurements Of PM2.5 and PM10 are made at the schools as well as inside the homes of a subset of 20 children with asthma. Daily personal exposure measurements of PM10 are also collected for these 20 children with asthma. Results from the first Five seasonal assessment periods reveal that mean personal PM10 (68.4 +/- 39.2 mug/m(3)) and indoor home PM10 (52.2 +/- 30.6 mug/m(3)) exposures are significantly greater (p < 0.05) than the outdoor PM10 concentrations (25.8 +/- 11.8 mug/m(3)). The same was also found for PM2.5 (indoor PM2.5 = 34.4 21.7 mug/m(3); outdoor PM2.5 = 15.6 +/- 8.2 mug/m(3)). In addition, significant differences (p < 0.05) in community-level exposure to both PM10 and PM2.5 are observed between the two Detroit communities (southwest PM10 = 28.9 +/- 14.4 mug/m(3), PM2.5 = 17.0 +/- 9.3 mug/m(3), eastside PM10 = 23.8 +/- 12.1 mug/m(3), PM2.5 = 15.5 +/- 9.0 mug/m(3)). The increased levels in the southwest Detroit community are likely due to the proximity to heavy industrial pollutant point sources and interstate motorways. Trace element characterization of filter samples collected over the 2-year period will allow a more complete assessment of the PM components. When combined with other project measures, including concurrent seasonal twice-daily peak expiratory flow and forced expiratory volume at 1 sec and daily asthma symptom and medication dairies for 300 children with asthma living in the two Detroit communities, these data will allow not only investigations into the sources of PM in the Detroit airshed with regard to PM exposure assessment but also the role of air pollutants in exacerbation of childhood asthma.