Particulate Air Pollution and Daily Mortality: The Phase I Report of the Particle Epidemiology Evaluation Project. Phase I.B: Analyses of the Effects of Weather and Multiple Air Pollutants

Special Report, March 1997

The Phase I.B Report of the Particle Epidemiology Evaluation Project.

The Health Effects Institute began the Particle Epidemiology Evaluation Project in 1994 to evaluate the emerging epidemiologic evidence of a relation between particulate air pollution and daily mortality. A growing number of studies reported that daily mortality rates rose in association with levels of particulate air pollution below the current National Ambient Air Quality Standard (NAAQS) for particulate matter. Some investigators interpreted their findings as indicating that particulate air pollution has a causal effect on increases in daily mortality. Critics disputed this interpretation, and questioned whether other scientists could replicate the results. Some critics asserted that the reported associations might be artifacts of the particular statistical methods used, or might be due to incomplete statistical adjustment for the effects of weather factors or other air pollutants.

In Phase I.B, Drs. Jonathan M. Samet and Scott L. Zeger and their colleagues at the Johns Hopkins University School of Hygiene and Public Health (1) compared approaches for controlling the effects of weather variables when analyzing the connection between air pollution and daily mortality, primarily focusing on Synoptic Weather Categories, an approach newly proposed by Dr. Laurence S. Kalkstein of the University of Delaware; and (2) evaluated the association between particulate air pollution and daily mortality in the Philadelphia metropolitan area using statistical models that included data for five pollutants regulated under the Clean Air Act Amendments of 1990 (referred to as criteria pollutants).


- HEI Statement

- Contributors to the Project

- Air pollution, weather, and mortality in Philadelphia 1973–1988, Jonathan M. Samet, Scott L. Zeger, Julie E. Kelsall, Jing Xu, and Lawrence S. Kalkstein

- Commentary, the Oversight Committee of the Particle Epidemiology Evaluation Project

- Comments from the HEI Health Review Committee

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