Many people exposed to airborne concentrations of ozone around the permissible concentration rapidly develop a headache. The headache will often disappear after a few minutes in fresh air. Chronic Effects Long-term exposure to ozone at concentrations above 0.1 ppm, or a single high exposure, may lead to some reduction in lung function. This is because scar tissue can form in the lung. There is also some evidence that the oxidizing effect of ozone could lead to premature aging of the body as a whole.
Medical studies show no evidence of ozone causing cancer or lung allergies or harming the unborn.
Individuals with a history of heart or respiratory disease should take every precaution to avoid exposure to ozone. The owner of any ozone installation should advise any person who may be exposed to ozone about this hazard.