LIMITED EXPOSURE OF RATS TO H2SO4 WITH AND WITHOUT O-3

Abstract

The effects of H2SO4 [occupational and environmental hazard to humans] alone and with O3 on rats were determined. Rats were exposed for 8 h daily to an atmosphere containing either nebulized H2SO4, H2SO4 plus 0.9 ppm O3, or 0.9 ppm O3. The atmosphere in the exposure chambers was maintained at a fairly constant temperature and humidity. Nebulized H2SO4 was delivered uniformly to provide a particle size of about 0.3 .mu.m mass median diameter (MMD) and a mass concentration of 2 mg/m3. Animals exposed to 2 mg/m3 of H2SO4 daily for 82 days showed very slight morphologic injury to the respiratory tract. Biological effects were readily demonstrable in rats exposed to H2SO4 plus O3 or to O3 alone, possibly with some enhancement of effect in animals exposed to the mixture. The effects were characteristic of the response to O3 alone.