The Responses of Animals Inhaling Nitrogen Dioxide For Single, Short-term Exposures

Abstract

Abstract Rats and dogs were exposed for single 5- to 60-minute periods to various concentrations of NO2. Changes in lung to body weight ratios of rats correlated directly with the severity of exposure to NO2. The kidney to body weight ratios of rats, the hematocrits, and blood platelet counts of dogs were of little or no value in evaluating the severity of NO2 exposures. Dogs had only mild toxic signs at NO2 concentrations which caused pulmonary edema in rats. Based on lung to body weight ratios of rats, the responses of dogs, and the pathological changes found in exposed animals, the threshold concentrations of NO2 found were 104, 65, and 28 ppm for 5, 15, and 60 minutes, respectively.