
                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, September 14, 1995                   TAG: 9509140096
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-2   EDITION: METRO 
SOURCE: Associated Press
DATELINE: GENEVA                                LENGTH: Medium

ANTARCTIC OZONE HOLE IS AS BIG AS EUROPE

The hole in the Earth's ozone layer is growing faster than ever and is twice the size it was this time last year, the U.N. weather agency said Tuesday.

Ozone, a gas in the stratosphere, prevents harmful ultraviolet radiation from reaching the Earth. Its depletion, caused in large part by industrial chemicals, is believed to increase the incidence of skin cancer and cataracts.

The hole, first observed over Antarctica in the 1980s, has reappeared each September and October since then. With the onset of winter in the polar region, temperatures in the stratosphere plunge, hastening ozone depletion.

The hole is getting bigger despite a reduction in ozone-destroying chemicals such as chlorine and bromine, because these chemicals have a life of 60 to 100 years.

So far, the hole has expanded to 3.9 million square miles - roughly the size of Europe - according to the World Meteorological Organization.

At that rate, the hole could surpass the record 24 million square miles it reached at the end of September last year, the U.N. agency said.

The accelerated spread of the hole has surprised but not alarmed experts, who predict the ozone layer will get even worse before it recovers.

``From the end of July through August and early September, ozone levels in this polar region have depleted by an average of 1 percent a day ... more rapidly than ever before,'' said Rumen Bojkov, special adviser on ozone to the agency. ``Every 1 percent drop in ozone means roughly 1.3 percent to 1.5 percent more ultraviolet radiation reaching the surface.''

He said each 1 percent increase in ultraviolet radiation is thought to increase chances of skin cancer and eye cataracts by 2 percent.

The U.N. weather agency has been monitoring ozone levels in Antarctica for the past 40 years. Already in August, the region had 30 percent to 35 percent less ozone than in 1957, before depletion began.

The ozone layer also has deteriorated over Europe and North America, but to a lesser extent. The agency says ozone levels over Europe and North America have diminished 10 percent to 15 percent since 1957. At the same time, ultraviolet radiation has increased 13 percent to 15 percent.

``This is something surplus to the normal ultraviolet everyone is getting,'' Bojkov said. ``It is undesirable because it is a cumulative. Everyone collects more radiation over a lifetime. It is not dangerous at the moment, but it could be, depending on how long such conditions continue.''

Without the Montreal Protocol, the 1987 agreement by countries to reduce worldwide use of ozone-destroying chemicals, Europe and North America would have more than 35 percent more ultraviolet radiation by now, he said.

The organization expects the ozone decline to become more severe the next 10 years, reducing levels over Europe and North America by at least another 5 percent.

After that, the depletion is expected to slow before starting to recover around 2040.

``We expect ozone levels to recover, but not before 2050 or 2070, and that is if everyone sticks to the rules,'' said Bojkov.

by CNB