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...made chemicals are destroying the ozone layer, but so are natural ones. The 1991 Mount Pinatubo eruption spewed ozone-unfriendly chlorine compounds into the air; researchers believe that these were partly responsible for the record-breaking ozone hole that opened up over Antarctica last year...
...article describing the team's research, which appeared in yesterday's issue of Nature, presents data which shows that a chemical, known as CGRP, present in nerves and in increased levels during stress or anxiety in the skin's upper layer regulates the activity of neighboring immune cells...
...hailed as the greatest success yet in the defense of Planet Earth. Many a President and Prime Minister present themselves as the saviors of the ozone layer -- the leaders who rescued the fragile atmospheric shield that protects all living things from the sun's dangerous ultraviolet rays. This airbrushed view of history starts in 1985, when scientists realized that an ozone hole had opened over the South Pole -- the result of an atmospheric assault by man- made chemicals called chlorofluorocarbons, which are commonly used in refrigerators and air conditioners. Soon after this disturbing surprise, the diplomats of the world were...
There is only one problem with this fabled success story: the rescuers may have arrived too late. No matter how quickly manufacturers halt the production of CFCs, billions of pounds of the chemicals already produced will continue to seep into the atmosphere and rise inexorably to attack the ozone layer. Worse, measurement after measurement since the mid-1980s has shown that ozone loss has been greater and more rapid than scientists predicted. Last month in Science magazine, researchers disclosed new satellite readings showing that in 1992 the average concentration of ozone in the upper atmosphere around the globe...
...million into developing substitutes during the late 1970s, all but halted its research shortly after Reagan's election because no further regulation was on the horizon. Earlier, Du Pont had publicly committed itself to stop production of CFCs if "reputable evidence" showed they posed a hazard to the ozone layer. The company, however, set a tough standard for what constituted "reputable evidence." Du Pont challenged Rowland at every turn in the 1970s, and he believes the company's aggressiveness sent a chilling message to other scientists in the field...