Word: cfcs
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
...result of increased sunspot activity or the unusual weather systems of the Antarctic. It is now widely accepted that winds are partly responsible, but scientists are increasingly convinced that there is a more disturbing factor at work. The culprit: a group of man-made chemicals called chlorofluorocarbons (CFCs), which are used, among other things, as coolants in refrigerators and air conditioners, for making plastic foams, and as cleaning solvents for microelectronic circuitry. Mounting evidence has demonstrated that under certain conditions these compounds, rising from earth high into the stratosphere, set off chemical reactions that rapidly destroy ozone...
...precise chemical process is still uncertain, but the central role of CFCs is undeniable. Last month Barney Farmer, an atmospheric physicist at the Jet Propulsion Laboratory in Pasadena, Calif., announced that his ground-based observations as a member of the 1986 Antarctic National Ozone Expedition pointed directly to a CFC-ozone link. "The evidence isn't final," he said, "but it's strong enough." Earlier this month, results from NASA's Punta Arenas project confirmed the bad news. Not only was the ozone hole more severely depleted than ever before -- fully 50% of the gas had disappeared during the polar...
...more cases of skin cancer a year in the U.S. alone, a 2% increase. These dangers were enough to spur representatives of 24 countries, gathered at a United Nations-sponsored conference in Montreal last month, to agree in principle to a treaty that calls for limiting the production of CFCs and similar compounds that wreak havoc on the ozone...
...propellants in aerosol sprays. As industrial chemicals, they were ideal. "The propellants had to be inert," says Chemist Ralph Cicerone, of the National Center for Atmospheric Research. "You didn't want the spray in a can labeled 'blue paint' to come out red. Since then the growth of CFCs has been fabulous, and they've been pretty useful." Indeed, CFCs turned out to be a family of miracle chemicals: produced at a rate of hundreds of thousands of tons yearly, they seemed almost too good to be true...
Among the protocol's signers are the U.S., Canada, Japan and the twelve- nation European Community; the U.S. and the E.C. annually produce about three- fourths of the world's 1 million tons of CFCs. The only major producer of CFCs that has not yet endorsed the treaty is the Soviet Union, whose representatives said the document would have to be studied in Moscow first. However, Vladimir Zakharov, the chief Soviet delegate, predicted his country would eventually approve the pact...