Air Pollution, Mortality, and Weather

Abstract

Daily deaths for the years 1960 through 1964 in New York city (excluding April to September) were studied in relation to SO₂, smoke shade, temperature deviations from normal, wind speed, sky cover, and rainfall. To eliminate seasonal effects. deaths were expressed as deviations from a five-year “normal.” SO₂ was related to mortality to a greater degree when smoke shade was held constant than was smoke shade when SO₂ was held constant and was, therefore, used as an index of air pollution. Evidence suggests that this increase in mortality was associated with increased SO₂ independent of weather factors studied. The difference in mean number of daily deaths on days with mean SO₂ levels of 0.20 ppm or less compared with days having mean SO₂ levels of 0.40 ppm or more is estimated to have been 10 to 20 deaths per day.