Development and Persistence of Adaptation to Ozone Exposure in Ozone-Sensitive Southern California Residents

摘要

Eleven healthy volunteer subjects believed to be atypically reactive to ozone were exposed to approximately 0.47 ppm ozone (ultraviolet calibration method) in purified air for four successive days to develop adaptation if possible. They were reexposed similarly once during each of the following five weeks to investigate the persistence of the adaptive response. Exposures lasted two hours and included stresses of heat and intermittent moderate exercise. Responses to ozone were assessed by forced expiratory lung function tests and by subjects' reports of symptoms. For the group as a whole, the time courses of lung function and symptom responses were very similar. For the typical subject in this group, adaptation was partially lost after four ozone-free days, and more or less completely lost after seven ozone-free days.