Exposure-effect relationship of selected pulmonary function measurements in subjects exposed to ozone

Healthy adult male volunteer subjects were exposed to 0.15, 0.3, 0.45 and 0.5 ppm ozone (O3) with and without intermittent light exercise. The results suggest that the subject's level of exercise during exposure is considerably related to the magnitude of changes in lung function and the occurrence rate of respiratory symptoms at any given O3 concentration, and that among healthy subjects there is a considerable range of reactivity to O3 exposure. A level of 0.15 ppm O3 with intermittent light exercise produced a significant decrease of specific airway conductance in most subjects and coughing during deep inspiration in five of 15 subjects, while a level of 0.5 ppm O3 produced fewer effects when the subject did not exercise. The nonsmoker is more reactive to O3 than the smoker. The subject's level of exercise during exposure and his smoking habit are two important factors in evaluating the exposure-effect relationship of O3.