Source identification of ambient PM2.5 for inhalation exposure studies in Steubenville, Ohio using highly time-resolved measurements

作者：Morishita Masako^*; Keeler Gerald J; Kamal Ali S; Wagner James G; Harkema Jack R; Rohr Annette C

来源：Atmospheric Environment, 2011, 45(40): 7688-7697.

DOI：10.1016/j.atmosenv.2010.12.032

• Steubenville
• PM2.5
• Cardiovascular disease
• Trace elements
• Receptor modeling

Recent epidemiological and toxicological studies have suggested that short-term elevations of ambient fine particle mass concentrations (aerodynamic diameter <2.5 mu m, PM2.5) can increase cardiac and pulmonary health risks. Thus, examining temporal variations of chemical changes in ambient PM2.5 that could pose the greatest health risks and identifying its sources is critical so that the most toxic categories can be controlled. In this study we collected detailed air quality data in Steubenville, Ohio in August 2006 with the ultimate goal to evaluate associations between cardiovascular (CV) parameters measured in exposed laboratory animals and the chemical and elemental composition of PM2.5. Current approaches using radiotelemetry to measure CV parameters in conscious laboratory animals are capable of collecting continuous recordings. To provide a robust and analogous dataset that can be better matched with CV responses, we have incorporated a highly time-resolved sampling method to characterize trace elements and thereby obtain more robust input data to determine potential emission sources. We applied positive matrix factorization (PMF) to trace element concentrations from 30-minute ambient PM2.5 samples in Steubenville, Ohio, an area designated as a non-attainment area for the PM2.5 National Ambient Air Quality Standards by the Environmental Protection Agency.
The average ambient PM2.5 filter-based mass concentration during the 8-hour summer exposure study period was 26 +/- 11 mu g m(-3). Results from PMF indicated that six major factors contributed to the ambient PM2.5 mass during this time: coal combustion/secondary (39 +/- 46%), mobile sources (12 +/- 14%), metal coating/processing (10 +/- 11%), iron and steel manufacturing (5 +/- 5%), Pb factor (5 +/- 8%), and incineration/smelting (1 +/- 3%). The objectives of this paper are (1) to present chemical composition of ambient PM2.5 and its potential emission sources in Steubenville; and (2) to evaluate the PMF modeling results using observed meteorological data. These semi-continuous sampling approaches to determine potential emission sources have significant advantages over similar analyses using samples averaged over 8-24 h, and are being utilized by our group to determine associations of PM with acute CV responses from animal inhalation toxicology field studies.

• 出版日期2011-12