Pulmonary Function in Man After Short-Term Exposure to Ozone

Abstract

Normal subjects, smokers and nonsmokers, were exposed to either 0.37 or to 0.75 ppm ozone for two hours in an environmental chamber. Two hours of intermittent exercise in such atmospheres of ozone produced major changes in the lung function tests derived from the maximal expiratory flow. At higher concentrations of ozone, slightly greater effects were noted in smokers than nonsmokers, but at lower concentrations this difference was not evident. The total lung capacity was not significantly affected by the exposure, but the residual volume increased. This increase is closely related to the changes in the closing volume and indicates an early effect in the small airways. We may conclude that a concentration of 0.37 ppm ozone for a period of two hours is unacceptably high if impairment of pulmonary function is to be avoided in a normal, active population.