National Morbidity, Mortality, and Air Pollution Study. Part II: Morbidity and Mortality from Air Pollution in the United States

The National Morbidity, Mortality, and Air Pollution Study (NMMAPS) was designed to select multiple locations based on the specific criteria of population size and availability of PM₁₀ data from the US Environmental Protection Agency's Aerometric Information Retrieval System (AIRS) database, and to apply the same statistical procedures to all locations. Dr Jonathan Samet and his colleagues Johns Hopkins University conducted a time-series study of mortality effects in large US cities representing various levels of PM₁₀ and gaseous pollutants. The 20 and 90 largest cities were analyzed for effects of PM₁₀ and other pollutants on mortality; the 90 largest cities were analyzed for possible modification of PM₁₀ effects among cities by factors other than air pollutants. Coinvestigators at Harvard University also applied a unified statistical method, although different from the one used in the mortality analysis, to 14 cities with daily PM₁₀ data to examine effects on hospitalization among those 65 years of age or older.