In the troposphere, ozone is a pollutant. However, in the stratosphere, ozone is critical to the survival of the biosphere. If stratospheric ozone were brought down to the Earth's surface under STP conditions, the layer would compress to a thickness of 2 to 5 mm. Ozone protects all life on earth by absorbing harmful ultra-violet radiation. These high energy frequencies, if not absorbed or filtered by the ozone layer, may cause genetic mutations among lower organisms or melanoma, cataracts, and skin cancer among humans .
Sunlight plays a key role in the formation and destruction of ozone.
CFC's are used in a multitude of commercial applications including refrigeration, air-conditioning, foams, and solvents. The remaining carbon attachments are chlorine. 2 Chlorine atom of CFC breaks away step 3 Chlorine atom collides with ozone step 4 Chlorine atom breaks up ozone to form ClO and O 2 step 5 Free oxygen atom collides with chlorine monoxide step 6 Oxygen molecule released. Chlorine radical repeats cycle. Although ground measurements of ozone began in 1956, comprehensive satellite measurements with Nimbus-7 didn't begin until 1978.