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Title: Effects of NO/sub 2/ alone and in combination with O/sub 3/ on young men and women

Journal Article · · J. Appl. Physiol.; (United States)
OSTI ID:6271772

Previous studies of 2 h of exposure to NO/sub 2/ 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 demonstrate 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/sub 2/ and/or enhance the effects of exposure to 0.30 ppm O/sub 3/, 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 NO/sub 2/, 0.30 ppm O/sub 3/, and 0.60 ppm NO/sub 2/ plus 0.30 ppm O/sub 3/ were randomly delivered via an obligatory mouthpiece inhalation system. Treatment effects were assessed by standard pulmonary function tests and exercise ventilatory and subjective symptoms response. Two-way analysis of variance with repeated measures and post hoc analyses revealed a statistically significant (P less than 0.05) effect of O/sub 3/ on forced expiratory parameters, specific airway resistance, exercise ventilatory response, and reported subjective symptoms of respiratory discomfort. In contrast, no significant effect of NO/sub 2/ was observed nor was there any significant interaction of NO/sub 2/ and O/sub 3/ in combination. There were no significant differences between male and female responses to gas mixture treatments. It was concluded that inhalation of 0.60 ppm NO/sub 2/ for 1 h while engaged in heavy sustained exercise does not elicit effects evidenced by measurement techniques used in this study nor evoke additive effects beyond those induced by 0.30 ppm O/sub 3/ in healthy young adults.

Research Organization:
Univ. of California, Davis
OSTI ID:
6271772
Journal Information:
J. Appl. Physiol.; (United States), Vol. 62:4
Country of Publication:
United States
Language:
English