EFFECTS OF NITROGEN-DIOXIDE ON PULMONARY-FUNCTION IN HUMAN-SUBJECTS - ENVIRONMENTAL CHAMBER STUDY

Twenty human subjects with asthma and chronic bronchitis and 10 normal, healthy adults were exposed to 0.5 ppm of nitrogen dioxide for 2 hr in an environmental chamber. Seven of the 13 subjects with asthma experienced symptoms with exposure, while only one each of the subjects with chronic bronchitis and the healthy, normal group experienced symptoms. Significant pulmonary function changes from control values with exposure to NO2 were observed in decreased quasistatic compliance for the 10 normal subjects and the 20 subjects with asthma and chronic bronchitis. In addition, functional residual capacity increased significantly for the 20 subjects with asthma and chronic bronchitis. The subjects with asthma and the subjects with chronic bronchitis as separate groups, however, did not show any significant changes with exposure. With this study we are reasonably confident that exposure of subjects with asthma and chronic bronchitis to 0.5 ppm NO2 for 2 hr does not produce a significant decrement in their pulmonary function. © 1979.