This pamphlet provides answers to questions about ozone. It will explain what ozone is, how it can affect your health, and what you can do to prevent or reduce exposure to it. In the upper atmosphere, ozone protects us from the sun's damaging ultraviolet radiation. At the earth's surface, ozone is a respiratory irritant that can affect health, especially of children and the elderly.
Ozone is a colorless gas with a pungent odor, and, if inhaled, can damage or kill living cells.
It is normally created in the upper atmosphere by the action of sunlight on normal oxygen. Hydrocarbons are released mainly by motor vehicles and evaporation of fuel, paint, and dry cleaning fluids. Nitrogen compounds are made when fuel is burned, such as in power plants and motor vehicles. Additionally, ozone is formed when electrical charges, such as lightning, turn normal oxygen into ozone. Ozone turns back into oxygen on contact with indoor surfaces such as walls or furniture.