The hole that spells cancer for children

Man-made damage to the Earth's protective ozone layer will cause around 8,000 extra skin-cancer cases in Britain each year, according to a panel of government advisers.

These extra cases will be among people who are now children. As they go through life, they will receive an increased dose of ultraviolet light in sunshine because of the thinning of the layer by industrial and agricultural chemicals.

The epidemic will occur even though steps have been taken to curb these chemicals and allow the layer, located in the stratosphere above 40,000ft, to begin healing itself. Scientists are now forecasting that it will be another 10 years, perhaps as long as 14, before this recovery process begins. Ozone holes will continue to open up above the Antarctic until the middle of the next century.

The estimate of 8,000 extra skin cancer cases a year came in yesterday's first report by Britain's new ultraviolet impacts review group, made up of scientists and doctors. It is the first time the Government has been given a figure for the likely harm to the population.

Dr Ann Webb, of the University of Manchester Institute for Science and Technology, said the extra cases could be avoided if people became more aware of the risks and reduced their exposure to sunshine by wearing clothes and using suncream. But she warned: "Even if it's a cloudy day the ultraviolet will be higher than it would be otherwise. Over a lifetime you will increase your dose."

There are estimated to be about 80,000 cases a year at the moment. This number has risen markedly in recent decades, probably because of extra exposure to sunshine on holidays abroad. In 2050, this can be expected to reach 88,000, unless people reduce their exposure.

All three main types of skin cancer have been linked with ultraviolet light. About 10 per cent of cases are of malignant melanoma, the hardest to treat. It appears to be associated with intense sunshine in childhood.

The report says that the lifetime risk of skin cancer for today's children will be 4-10 per cent higher because of ozone damage. The increased ultraviolet light is also expected to affect crops and animals, plankton in the sea, and synthetic materials, although it is not yet possible to gauge the level of damage.

Each spring in the southern hemisphere for the past 15 years, most of the ozone over the Antarctic has disappeared. These "ozone holes" have become deeper and wider and in the past few years, holes have come close to forming over the Arctic too.

In March this year, there was a record low level of ozone in the atmosphere over Britain, and unusually high levels of ultraviolet light for the time of year were also measured.

The most important ozone-destroying chemicals are CFCs and HCFCs, used in refrigeration and air conditioning, and methyl bromide used in crop storage and horticulture. Although they have been, or will be, phased out, their combined level in the upper atmosphere is not expected to peak until early next century. Next week, officials from dozens of countries meet in Costa Rica further to discuss the phasing-out process under the Montreal protocol.