The ozone layer diminishes more each year. As the area of polar ozone depletion (commonly called the ozone hole) gets larger, additional ultraviolet rays are allowed to pass through. These rays cause cancer, cataracts, and lowered immunity to diseases.1 What causes the depletion of the ozone layer? In 1970, Crutzen first showed that nitrogen oxides produced by decaying nitrous oxide from soil-borne microbes react catalytically with ozone hastening its depletion. His findings started research on "global …showed first 75 words of 833 total…

…showed last 75 words of 833 total…HCFC-22 is marketed as a coolant for commercial and residential air-conditioning systems. HCFC- 141b and HCFC-123 are used for making urethane and other foams.1 Each year since the 1970s, the stratospheric ozone above Antarctica disappears during September and reforms in November when ozone-rich air comes in from the north. Because new chemicals that do not destroy ozone are replacing ozone-depleting chemicals, the ozone hole is projected to disappear by the middle of the 21st century.