Healing Ozone Layer Lowers UV Exposure, Report Finds

http://www.spiegel.de/international/world/0,1518,821822,00.html


AFP/ NASA
A new report suggests that the 1987 ban on hydrochlorofluorocarbons has been successful in reversing the erosion of the ozone layer and that exposure to UV rays is declining.

For decades, the threat continued to grow: The protective ozone layer 20 kilometers (12.4 miles) above the planet was thinning, opening a path for exposure to ultraviolet radiation from the sun. Even though experts are not in agreement today on the extent of the problem, it is certain that the radiation increased the risk of skin cancer.

The sustained damage to the ozone layer had been caused by aerosol spray cans and refrigerators emitting chlorofluorocarbons (CFCs). In 1987, the United Nations responded, banning the manufacture and use of CFCs and other substances under the Montreal Protocol. Since then, the hole in the ozone layer has been shrinking.

In autumn 2010, scientists reported the first success, saying the ozone layer had begun to heal. Now a new study shows for the first time that the healing of the ozone layer is also actually improving the health situation for people. Carcinogenic UV rays on the ground have also been diminishing in recent years, researchers led by Christos Zerefos at the Research Centers for Atmospheric Physics and Climatology at the Academy of Athens in Greece conclude in their study, published by the scientific publication Atmospheric Chemistry and Physics.

"The results are encouraging," said Markus Rex, a respected ozone expert at Germany's Alfred Wegener Institute for Polar and Marine Research in Potsdam. The fact that the ozone layer in the regions researched has become thicker is a result of the successful Montreal Protocol, he added.