Ozone
Ozone is a gas that occurs both in the Earth’s upper atmosphere (the stratosphere) and at ground level. Ozone can be “good” or “bad” for people’s health and the environment, depending on its location in the atmosphere. A molecule of ozone contains three oxygen atoms.
“Good” ozone is produced naturally in the stratosphere and is “good” because it blocks harmful ultraviolet (UV) radiation from reaching Earth’s surface where it can harm people and ecosystems.
“Bad” ozone is an air pollutant found at ground level and is “bad” because it is harmful to breathe and can damage crops, trees, and other vegetation. Ground-level ozone is a main component of urban smog.
For more info, see www.epa.gov/oar/oaqps/gooduphigh. To get the UV index for your city or town, or the entire United States, check out the EPA’s SunWise site, http://www.epa.gov/sunwise/uvindex.html.
Sources:
-- “Ozone: Good Up High, Bad Nearby”, EPA brochure online. Accessed Aug. 30, 2007. http://www.epa.gov/oar/oaqps/gooduphigh/index.html
-- “UV Index,” EPA’s SunWise site. Accessed Aug. 30, 2007. http://www.epa.gov/sunwise/uvindex.html
