Summary
Ozone is a gas. It can be good or bad, depending on where it is. "Good" ozone occurs naturally about 10 to 30 miles above the Earth's surface. It shields us from the sun's ultraviolet rays. Part of the good ozone layer is gone. Man-made chemicals have destroyed it. Without enough good ozone, people may get too much ultraviolet radiation. This may increase the risk of skin cancer, cataracts, and immune system problems.
"Bad" ozone is at ground level. It forms when pollutants from cars, factories, and other sources react chemically with sunlight. It is the main ingredient in smog. It is usually worst in the summer. Breathing bad ozone can be harmful. It can cause coughing, throat irritation, worsening of asthma, bronchitis, and emphysema. It can lead to permanent lung damage, if you are regularly exposed to it.
Environmental Protection Agency
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Ozone
(National Institute of Environmental Health Sciences)
Learn More
- Air Pollution and Asthma (For Parents) (Nemours Foundation) Also in Spanish
- Air Quality Guide for Ozone (Environmental Protection Agency) Also in Spanish
-
Ozone
(National Institute of Environmental Health Sciences)
- Ozone Air Purifiers: Can They Improve Asthma Symptoms? (Mayo Foundation for Medical Education and Research)
- Ozone Generators That Are Sold as Air Cleaners (Environmental Protection Agency, Indoor Environments Division)
- Ozone Layer Protection (Environmental Protection Agency)
- Ozone: Good Up High, Bad Nearby (Environmental Protection Agency, Office of Air Quality Planning and Standards)
- Sunwise (Environmental Protection Agency)
-
Tox Town
(National Library of Medicine)
Also in Spanish
- You Can Help Keep the Air Cleaner -- Every Day (Environmental Protection Agency)
Related Issues
- Green Vehicle Guide (Environmental Protection Agency)
- Greenhouse Gases (National Oceanic and Atmospheric Administration)
Clinical Trials
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ClinicalTrials.gov: Ozone Exposure
(National Institutes of Health)
Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)
Reference Desk
- Ozone - Current Air Quality Index (Environmental Protection Agency)
Children
- Air Pollution and Asthma (For Parents) (Nemours Foundation) Also in Spanish
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Ozone (Environmental Health Student Portal)
(National Library of Medicine)
- Sunwise (Environmental Protection Agency)