WESTERN governments have touched the panic button because of the recent evidence of ozone depletion over the Arctic and large parts of the high and middle latitudes. The ozone hole is no longer confined to the atmosphere over the South Pole.

Temporary depletion of ozone over the northernmost parts of USA, Canada, Europe and Russia could be upto 40 per cent in late winter and early spring. Canadian mothers now prevent children from playing unprotected in the sun and Danes have been warned to shield themselves for fear of skin cancer. Fortunately, there is little evidence to suggest a decrease in ozone over the tropics.

The ozone layer shields the earth's surface from ultraviolet-B (UV-B) light which can cause skin cancer and cataracts and cause deterioration in the human immune system and crop yields.

In September 1991, ozone losses over Antarctica were found to be as much as 60 per cent of the precreiites ozone hole averages. As the Arctic stratosphere - the upper layer of the atmosphere - is warmer than the Antarctic stratosphere, scientists don't expect large ozone losses there.

However, data generated by the Upper Atmosphere Research Satellite has indicated high concentrations of chlorine monoxide - a byproduct of CFC (chlorofluorocarbon) decomposition - over north- ern Europe. For the first time, the World Meteorological Organisation has reported changes in ground level ultraviolet light as a result of decreases in stratospheric ozone.

Soon after the ozone hole over Antarctica was confirmed in 1985, a number of governments agreed on the Montreal Protocol to control substances that deplete the ozone layer. However, with evidence of the ozone hole developing further, western governments are pushing for an earlier phase-out. German environment minister Klaus Topfer has called on other countries to phase out CFC production by 1995 panic as Germany plans.

In USA, the Bush administration has decided to end CFC production by the end of 1995. The Imperial Chemical Industries (ICI), the largest CFC manufacturer in UK, has decided to phase out production by 1995, two years ahead of the earlier target.

At a recent meeting of the United Nations Environment Programme (UNEP) held in Geneva to review the progress under the Mo@treal Protocol, the Nordic governments pushed for a ban by 1994, whereas the European Community talked of a ban by 1995.