Aerosols Formed by Oxidation of Sulfur Dioxide

Abstract

Literature relating to the toxicology of sulfuric acid and particulate sulfates is reviewed. These materials, which have a greater irritant potency than sulfur dioxide, may be formed in the atmosphere by oxidation of sulfur dioxide. Thus, air quality standards for sulfur dioxide must take into account the toxicology of these oxidation products. The particle size of the particulate oxidation products of sulfur dioxide is of extreme importance. Data on concentration alone are insufficient to predict irritant potency. The most important size range is at the submicron level. Data on animal experiments, including the criteria of mortality, pathological findings in the lung, and studies utilizing altered pulmonary function are discussed. Additional data are needed on exposure of human subjects. Experiments must be performed so that both physiological methodology and aerosol technology are properly controlled.