Respiratory effects of two-hour exposure with intermittent exercise to ozone, sulfur dioxide and nitrogen dioxide alone and in combination in normal subjects

Abstract

Seven adult male healthy volunteer subjects were exposed to 0.15 ppm each of O₃, SO₂ and NO₂ alone and in combination, with intermittent light exercise for two hours. Three of the 7 subjects developed cough during deep inspiration and one subject had chest pain during exposure to O₃ alone. Among the various indices of pulmonary function tests, specific airway conductane (G_aw/V_tg) was the most sensitive index to examine the changes produced by the exposure to O₃ and other pollutants. Significant decrease of G_aw/V_tg in comparison with control measurements was observed in 6 of 7 subjects during exposure to O₃ alone, and in all subjects during exposures to the mixture of O₃ and other pollutants. However, no significant enhancement of effect was observed in the mixture of O₃ and other pollutants, although a slightly greater decrease of G_aw/V_tg was observed for the mixture of O₃ and other pollutants than for O₃ alone.