Abstract
Aerosols of zinc ammonium sulfate cause an increase in pulmonary flow resistance in guinea pigs exposed for one hour. Zinc sulfate and ammonium sulfate have similar actions but are less potent irritants than the double salt. Zinc ammonium sulfate aerosol was studied at mean' particle sizes by weight of 0.29, 0.51, 0.74 and 1.4μ. The smaller the particles, the greater the irritant action at any given mass concentration. When the number of particles per unit volume is equal, the larger aerosols are more irritating. When zinc ammonium sulfate (0.3μ) and sulfur dioxide were administered together the response to the mixture was more than additive.
