Scientists and others have a keen interest in ozone depletion, given that the increased amounts of ultraviolet radiation that reach the Earth's surface because of ozone loss have the potential to increase the incidence of skin cancer and cataracts in humans, harm some crops, and interfere with marine life. NASA and NOAA instruments have been measuring Antarctic ozone levels since the early 1970s. Since the discovery of the ozone hole in 1985, TOMS and SBUV have been key instruments for monitoring ozone levels over the Earth. Analysis of the historical data indicated that the hole has existed since at least 1979. A Dobson unit measures the physical thickness of the ozone layer at the pressure of the Earth's surface.
Ozone shields life on Earth from the harmful effects of the Sun's ultraviolet radiation.
Most atmospheric ozone is found in a thin layer between 6-18 miles up.