Abstract |
Health and pollution control professionals and the general public need to develop a more complete understanding of the health effects of ozone (O3) because it has not been possible to significantly reduce ambient O3 levels using current strategies and control. In areas occupied by more than half of the US population, current peak ambient O3 concentrations are sufficient to elicit measurable transient changes in lung function, respiratory symptoms, and airway inflammation in healthy people engaged in normal outdoor exercise and recreational activities; the effects of O3 on transient functional changes are sometimes greatly potentiated by the presence of other environmental variables; and emulative structural damage occurs in rats and monkeys exposed repetitively to O3 at levels within currently occurring ambient peaks, and initial evidence from dosimetry models and interspecies comparisons indicate that humans are likely to be more sensitive to O3 than rats. The extent and significance of these effects, and the multibillion dollar costs of ambient O3 controls need to be considered in any future revisions of ambient standards and the Clean Air Act. The transient effects of O3 are more closely related to cumulative daily exposure than to one hour peak concentrations, and future revisions of the ambient standard for O3 should take this into account. (Copyright (c) 1989 Air & Waste Management Association.) |