Word: ultraviolet
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...have become a testament to the American conviction that a bronzed body radiates health and affluence. In a decade, the industry has burgeoned into 18,000 salons nationwide. Thousands of other businesses, like health clubs, have installed tanning booths. Now the pain: doctors are warning that exposure to the ultraviolet light emitted by sun lamps may result in afflictions, ranging from skin cancer to cataracts, that show up as much as 20 years later. Declares Dr. Stephen Katz, dermatology chief at the National Cancer Institute: "These things are hazardous...
Indeed, if the ozone layer diminishes over populated areas -- and there is some evidence that it has begun to do so, although nowhere as dramatically as in the Antarctic -- the consequences could be dire. Ultraviolet radiation, a form of light invisible to the human eye, causes sunburn and skin cancer; in addition, it has been linked to cataracts and weakening of the immune system. Without ozone to screen out the ultraviolet, such ills will certainly increase. The National Academy of Sciences estimates that a 1% drop in ozone levels could cause 10,000 more cases of skin cancer a year...
...Sciences report likened the upper atmosphere "to a city whose garbage is picked up every few years instead of daily." As long as five years after it leaves the ground, N2O may finally reach altitudes of 15 miles and above, where it is broken apart by the same ultraviolet radiation that creates ozone. The resulting fragments -- called radicals -- attack and destroy more ozone molecules. Another ozone killer is methane, a carbon-hydrogen compound produced by microbes in swamps, rice paddies and the intestines of sheep, cattle and termites...
...troposphere, CFCs are immune to destruction. But in the stratosphere, they break apart easily under the glare of ultraviolet light. The result: free chlorine atoms, which attack ozone to form chlorine monoxide (ClO) and O2. The ClO then combines with a free oxygen atom to form O2 and a chlorine atom. The chain then repeats itself. "For every chlorine atom you release," says Rowland, "100,000 molecules of ozone are removed from the atmosphere...
...remarkable scientific expedition takes the measure of the Antarctic ozone hole and spurs concern that life on earth may become increasingly vulnerable to cancer- causing ultraviolet radiation. Disturbing evidence is mounting that emissions of carbon dioxide and other gases are heating up the world' s climate at a rate unseen since the end of the ice age. See ENVIRONMENT...