Ozone Air Pollution
In the upper atmosphere ‘good’ ozone (O3) protects life on Earth from the sun's ultraviolet rays. At ground level ‘bad’ ozone is a criteria pollutant that is a significant health risk, especially for people with asthma. It also damages crops, trees and other vegetation and is the main component of smog. Ground level ozone is not emitted directly; it 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, vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC. Find out more about the good and bad of ozone: Is Ozone Good or Bad?