[NO2 inhalation in two smokers and two non-smokers].

Four healthy men were exposed to an anti-rust substance in a stainless steel tank. Acute respiratory failure developed in two of them, both non-smokers. Their chest roentgenograms revealed marked infiltration, which suggested pulmonary edema due to the inhalation of NO2 and hydrogen fluoride. These two patients recovered from respiratory distress within several days. However, small airway disease was still evident one year later. The other two, who were smokers, had only mild respiratory symptoms. These cases indicate that smoking may reduce the sensitivity to NO2. Further study is needed to elucidate the relationship between smoking and the severity of responses to NO2 inhalation.