This year's giant-sized ozone hole has put out any hopes of a slowdown in the annual thinning in the ozone layer above Antarctica, Auckland-based New Zealand Herald reported Monday.

The report said that the ozone hole that began forming last month is bigger than last year's, reaching 27 million sq km in thesecond week of this month.

But scientists do not yet know whether it will break the recordset in 2000, when the hole reached 28 million sq km, four times the size of Australia.

Last year's smaller ozone hole of 25 million sq km was due to meteorological conditions and not the result of bans on ozone-depleting chemicals, scientists say.

The paper quoted Alan Rodger, of the British Antarctic Survey, as saying that it would be at least a decade before they could saywith certainty that lower levels of chlorofluorocarbons (CFCs) were having an effect.

"Last year's hole should clearly be regarded as a one-off eventin the record so far," he said.

Scientists discovered in the mid-1970s that CFCs - synthetic chemicals found in aerosols, refrigeration coolants and air-conditioning - were depleting the ozone layer.

Ozone forms a protective shield above the Earth's surface, blocking the sun's harmful UV-B rays.

Southern Hemisphere inhabitants are exposed to higher levels of UV rays that can cause skin cancer, eye cataracts and affect immunity.