Ozone. The good, the bad, and the ugly

Sensitive individuals are at risk of adverse health effects from exposure to even modest levels of ozone. Such individuals are likely to develop respiratory symptoms and are more likely to be hospitalized when exposed to ozone at currently accepted levels. A review of scientific documents regarding the health effects of ozone has led the DHHS to agree with the EPA that the primary ambient air standard for ozone should be changed from 0.12 ppm (1-hour average) to 0.08 ppm (8-hour average). Achieving the proposed 0.08 ppm standard should decrease physician visits, hospitalization, and use of respiratory medications. In addition, because very susceptible healthy individuals may experience adverse health effects of the current standard, it is clear that the current standard provides little or no margin of safety, particularly for sensitive individuals. In order to avoid exposure to unhealthy levels of ozone, people should take precautions to minimize exposure from 2:00 to 6:00 pm on days when ozone levels are high. This is especially so for children, adults who are active outdoors, those with respiratory disease such as asthma, and people with unusual susceptibility to ozone.