Nasa reports that the hole over Antarctica had reached a record size of about 28.5 square kilometres by September 3. Scientists say the hole has stopped growing this year in area but the levels of ozone within it are continuing to fall. The lowest readings are usually at the end of September or early October. Lower levels of ozone are linked to increases in skin cancer and cataracts. There is also fear that ultraviolet radiation could harm plants and microbes.
Ozone is an unstable form of oxygen actually created by ultraviolet light.
Although production of ozone-destroying gases has been curtailed under international agreements, concentrations of the gases in the stratosphere are only now reaching their peak. Due to their long persistence in the atmosphere, it will be many decades before the ozone hole is no longer an annual occurrence. Scientists continuing to investigate this enormous hole are surprised by its size. At this point we can only wait to see how the ozone hole will evolve in the coming months. Although Nasa satellites began searching for signs of ozone destruction 20 years ago, the hole was discovered by British scientists taking balloon measurements in the Antarctic in 1985.