Associations between air pollution and mortality in Phoenix, 1995-1997

We evaluated the association between mortality outcomes in elderly individu als and particulate matter (PM) of varying aerodynamic diameters (in microm eters) [PM10, PM2.5, and PMCF (PM10 minus PM2.5)], and selected particulate and gaseous phase pollutants in Phoenix, Arizona, using 3 years of daily d ata (1995-1997). Although source apportionment and epidemiologic methods ha ve been previously combined to investigate the effects of air pollution on mortality, this is the first study to use derailed PM composition data in a time-series analysis of mortality. Phoenix is in the arid Southwest and ha s approximately 1 million residents (9.7% of the residents are > 65 years o f age). PM data were obtained from the U.S. Environmental Protection Agency (EPA) National Exposure Research Laboratory Platform in central Phoenix. W e obtained gaseous pollutant data, specifically carbon monoxide, nitrogen d ioxide, ozone, and sulfur dioxide data, from the EPA Aerometric Information Retrieval System Database. We used Poisson regression analysis to evaluate the associations between air pollution and nonaccidental mortality and car diovascular mortality. Total mortality was significantly associated with CO and NO2 (p < 0.05) and weakly associated with SO2, PM10, and PMCF (p < 0.1 0). Cardiovascular mortality was significantly associated with CO, NO2, SO2 , PM2.5, PM10, PMCF (P < 0.05), and elemental carbon. Factor analysis revea led that both combustion-related pollutants and secondary aerosols (sulfate s) were associated with cardiovasdar mortality.