Abstract |
In the proposed rule on the National Ambient Air Quality Standards for particulate matter (PM), EPA committed to conduct a review and assessment of the numerous studies relevant to assessing the health effects of PM that were published too recently to be included in the 2009 PM Integrated Science Assessment (ISA). This report presents the findings of EPAs survey and provisional assessment of such studies. EPA has screened and surveyed the recent literature and developed a provisional assessment that places those studies of potentially greatest relevance to the current PM NAAQS review in the context of the findings of the 2009 PM ISA. The focus is on: (a) epidemiologic studies that used PM2.5 (i.e., fine PM) or PM10-2.5 (i.e., coarse PM) and were conducted in the U.S. or Canada, and (b) toxicological or epidemiologic studies that compared effects of PM from different sources, PM components, or size fractions. The provisional assessment is not intended to critically review individual studies or integrate the scientific findings to draw causal conclusions as is done for an ISA. This survey and assessment finds that that the new studies expand the scientific information and provide important insights on the relationships between PM exposure and health effects of PM. However, the new information and findings do not materially change any of the broad scientific conclusions regarding the health effects of PM exposure made in the 2009 PM ISA. |