Particulate Air Pollution and Mortality

Abstract

It has been recognized for many years that high levels of air pollution can lead to increased mortality and mor? bidity. The open question has been whether exposures at the lower levels currently found in the United States and other developed countries are also associated with such health effects, and secondly, whether the specific agent or agents within the mix of pollutants can be identified. A series of recent epidemiologic studies has highlighted the association between particulate air pol? lution and acute increases in morbidity and mortality in the United States. These studies have led to a review of the National Ambient Air Quality Standard for partic? ulate matter by the U.S. Environmental Protection Agency. In the last issue of Epidemiology, Moolgavkar and colleagues1 and Samet2 urged caution in evaluating the epidemiologic evidence, prompted by a re-analysis of previously published studies. We suggested the possibility of effects of particulate air pollution at current concentrations in the United States in a paper evaluating daily mortality in Steuben? ville, a small steel town on the Ohio River, for the years 1974?1984*3 These data showed that particulate air pol? lution, rather than sulfur dioxide (S02), the other major constituent of air pollution in Steubenville, was specifically associated with daily mortality. We then tested the hypothesis of an association be? tween particulate air pollution and mortality for the period 1973-1980 in Philadelphia, a larger city with very different air pollution sources and characteristics.4 Our principal finding was that total daily mortality was as? sociated with particulate air pollution measured as total suspended particulates (TSP). Although we found sim? ilar associations with SOz, in multiple regression analysis including both pollutants, the TSP effect estimate was more stable than the S02 effect estimate. Similar analyses have shown positive associations be? tween particulate air pollution and daily mortality in nine other communities in the United States: Santa Clara, CA,5 Detroit, Ml,6 Utah Valley, UT,7 St. Louis, MO,8 eastern Tennessee,8 Birmingham, AL,9 Cincin-