Ozone Depletion

Ozone is a relatively unstable form of molecular oxygen containing three oxygen atoms (03). Ozone near the earth's surface is the most noxious component of smog that is treated as an air pollutant in most industrial countries. The ozone layer in the stratosphere, however, shields the earth from ultraviolet radiation that is harmful to living organisms. This radiation comes from the sun, and too much of it can damage plant and animal cells, cause skin cancer and eye cataracts in humans, reduce crop yields, deplete marine fisheries, cause damage to materials of various kinds, and kill many smaller and more sensitive organisms.

Stratospheric ozone is found in a broad band, generally extending from about 15 to 35 km (9–22 miles) above the earth's surface. The amount ...