Sulfate Particulates: Size Distribution in Pittsburgh Air

Abstract

Sulfate particles with diameters of less than 1.7 microns contribute approximately 40 percent by weight to total sulfate particulate in Pittsburgh air. The irritant nature of these particles and their small size and associated long atmospheric residence time, as well as the short half-life of sulfur dioxide in the atmosphere, suggest that particulate sulfate may be abetter indicator of atmospheric pollution than sulfur dioxide.