Ground Level Ozone
Ground level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC. Breathing ozone can trigger a variety of health problems, particularly for children, the elderly, and people of all ages who have lung diseases such as asthma. Ground level ozone can also have harmful effects on sensitive vegetation and ecosystems.
General Information
- Basic information about ozone
- Health effects
- Ecosystem effects
- Ozone questions and answers
- Air quality standards
Technical Information
Regulatory Process
Reducing Ozone
Announcements
October 1, 2015 – EPA strengthens the National Ambient Air Quality Standards for Ozone, based on extensive evidence about ozone’s effects. Learn more