Effects of NO2 alone and in combination with O3 on young men and

with O3 on young men and women. J. Appl. Physiol. 62(4): 1698-1704, 1987.-Previous studies of 2 h of exposure to NO, at high urban atmospheric levels (i.e., 0.50-1.0 ppm), utilizing light-to-moderate exercise for up to 1 h have failed to demon-strate significant pulmonary dysfunction in healthy humans. To test the hypothesis that heavy sustained exercise would elicit pulmonary dysfunction on exposure to 0.60 ppm NO, and/or enhance the effects of exposure to 0.30 ppm OS, 40 aerobically trained young adults (20 males and 20 females) completed 1 h of continuous exercise at work rates eliciting a mean minute ventilation of 70 and 50 l/min for the males and females, respectively. Exposures to filtered air, 0.60 ppm N02, 0.30 ppm OS, and 0.60 ppm NO, plus 0.30 ppm OS were randomly delivered via an obligatory mouthpiece inhalation system. Treatment effects were assessed by standard pulmonary func