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NIOEN a beg,,rins f Antarctica's ozone noie BY SETH BORENSTEIN Associated Press WASHINGTON Antarctica's ozone hole finally is starting to heal, a new study finds. In a triumph of intema -' tional cooperation over a man-made environmental problem, research from the United States and the Unit- ed Kingdom shows that the September- October ozone hole is getting smaller and forming later in the year. And the study in Thurs- day's journal Science also shows other indications that the ozone layer is improving after it was being eaten away by chem- icals in aerosols and refrig- erants. Ozone is a combina- tion of three oxygen atoms; high in the atmosphere, it shields Earth from ultravio- let rays. The hole has shrunk by about 1.7 million square miles in the key month of September since the year 2000 - a decline of about one - fifth, the study found. That difference is more than six times larger than the state of Texas. It also is taking about 10 days longer to reach its largest size, according to the study. The hole won't be com- pletely closed until mid - century, but the healing is appearing earlier than scientists expected, said study lead author Susan Solomon of MIT. "It isn't just that the patient is in remission," Solomon said. "He's actual- ly starting to get better. The patient got very sick in the '80s when we were pump- ing all that chlorine" into the atmosphere. "I think it's a tremen- dous cause for hope" for fixing other environment problems, such as man- made climate change, said Solomon, who led two U.S. Antarctic expeditions to measure the ozone layer in the 1980s and has also been a leader in studying global warming. In the 1970s, scientists suggested that Earth's ozone layer - about 6 to 30 miles high in the strato- sphere - was thinning be- cause of chemicals called chlorofluorocarbons from aerosols and refrigerants. Those chemicals would break down into chlorine that attacked ozone, which at that level pro- tects people from ultravio- let rays linked to skin cancer. Then in early 1980s, a hole in the ozone layer over Antarctica start- ed appearing in October - and then, September and October - making the problem more urgent. Ozone thinned elsewhere on Earth and already has begun healing in the mid - dle section of the planet, but the Antarctic ozone' hole was the gaping wound that grabbed the world's attention. The Montreal Protocol, a 1987 global treaty to phase out many of the ozone - depleting chem- icals, led companies to develop new products that didn't eat away at the ozone layer. "There is a sense of mission accomplished,' " emailed University of California San Diego's Mario Molina, who shared the 1995 Nobel Prize for chemistry for his charac- terization of the ozone problem.