Episodic morbidity and mortality in relation to air pollution

Abstract

In many air pollution studies it is assumed that other factors which may influence the daily death rate in a community are negligible or randomized. One of these is weather, and this study was undertaken to determine if provision should be made for the suspected effects of everyday, or nonextreme, weather. Daily deaths in 10 large cities in the United States were correlated with weather elements for the months of January, April, July, and October of the years 1962–1965. In addition to showing the effects of spells of hot, humid weather and pollution episodes (“extreme” weather), it was determined that large interdiurnal changes of temperature, dewpoint, and pressure are accompanied by fluctuations in daily mortality. This applies to the north central and northeastern United States, where increases in mortality are coincident with prefrontal weather, decreases with postfrontal weather. Thus, there appear to be fluctuations in daily mortality on days which are the meteorological opposite of those on which pollution is most serious.