Evaluating Relationships Among Personal Risk Factors, Ambient Oxidant Exposure, and Chronic Respiratory Illness
SourceTransient respiratory irritant effects from exposure to elevated levels of ambient ozone are well documented in studies of human volunteers. Individual reactivity to ozone varies greatly, for unknown reasons. From animal toxicologic evidence, one may reasonably hypothesize that repeated ozone exposure increases the risk of developing chronic obstructive pulmonary disease (COPD). Relevant human evidence is sparse and equivocal. To test this hypothesis rigorously, an experiment combining controlled human exposures and epidemiologic surveys may be appropriate. This approach would also help to determine whether ambient ozone exposure acutely exacerbates COPD. Recent controlled human studies suggest that individuals' short-term reactivity to ozone is a persistent phenomenon, but may vary seasonally, probably in response to ambient exposures.