Word: ultraviolet
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...past two years, several scientists have become concerned about fluorocarbon propellants, used in aerosol sprays, drifting up through the stratosphere. In their doomsday scenario, these fluorocarbons break down to form chlorine atoms that gradually destroy the ozone shield protecting the earth from an overdose of the sun's ultraviolet rays; this, in turn, increases the risk that humans down on earth will develop skin cancer...
...Oregon last week heeded the warning by scientists that some gases in aerosol sprays can destroy the ozone layer in the stratosphere that protects earth from an overdose of the sun's ultraviolet rays (TIME, Oct. 7). The state legislature banned the sale after March 1, 1977, of aerosol cans that use chlorofluorocarbon compounds as propellants-mainly hair sprays, oven cleaners, insecticides and deodorants. Opponents of the measure claim that there is no hard evidence that the chlorofluorocarbons actually damage the ozone layer. But the Oregon lawmakers preferred not to wait for final proof, and the bill is expected...
Dermatologists at M.G.H. and the All-gemeines Krankenhausen in Vienna have modernized that technique. The new treatment combines the use of a drug called methoxsalen, which is extracted from the Egyptian plant, and an extraordinary high-intensity ultraviolet light. First the dermatologists have the patient swallow methoxsalen pills. Then they stand him in a telephone-booth-size closet lined with 48 of the special ultraviolet tubes. The patient stays in the booth from eight to 30 minutes, depending upon his degree of skin coloration...
...used in aerosol sprays. Writing in Science, University of Michigan Physicist Ralph Cicerone notes that spray-can gases, mostly chlorine compounds such as Freon, are highly stable under ordinary circumstances. Thus they are building up in the lower atmosphere and gradually rising toward the ozone layer. At that altitude, ultraviolet radiation breaks down Freon and the other chlorine-based gases, causing the release of chlorine atoms. They in turn react with ozone, converting it into ordinary oxygen...
Skin Cancer. Cicerone estimates that even if the use of aerosol sprays were halted immediately, the gases already in the atmosphere would cause a 10% reduction of ozone in the layer by 1990. That would result in a substantial increase of ultraviolet radiation on the earth, causing at the very least a greater incidence of skin cancer among humans. It might also disrupt the food chain by affecting food crops and plankton in the oceans. Lastly, the depletion of the ozone layer might have certain incalculable consequences like changing the earth's weather patterns...