Effect of low concentrations of ozone on pulmonary function in man

Abstract

Eleven subjects in sixteen experiments breathed 0.6–0.8 ppm of ozone through a mouthpiece for 2-hr periods. Measurements of pulmonary function were made immediately before and after each experiment. The changes were compared with those observed after a control experiment in which air was breathed through the same circuit for a similar period. In this concentration, ozone was found to produce a highly significant reduction in steady-state D1_CO of 5.4 ml CO/min mm Hg, a change about four times larger than that of the air control experiments. The vital capacity, FEV_0.75 x 40, and maximal midexpiratory flow rate decreased by about 10% after ozone breathing, the change being statistically significant in the first two of these only. Gas distribution, and dynamic and static pulmonary compliance were measured in two subjects and were not affected by ozone. Thickening of the alveolar wall by edema fluid is suggested as the most likely explanation of the fall in D1_CO that has been observed. The vital capacity and expiratory flow rates may be limited in part by tracheobronchial irritation that follows inhalation of 0.6 ppm of ozone for 2 hr. diffusing capacity after breathing ozone; lungs, effect of ozone; pulmonary function after breathing ozone Submitted on September 23, 1963