An international team of scientists has been gathered together to undertake the biggest study yet of ozone levels over the Arctic. Researchers from the EU, Canada, Iceland, Japan, Norway, Poland, Russia, Switzerland and the US will examine the processes that control ozone amounts during the Arctic winter more than 20 kilometres above the Earth.
Ozone is a molecule in which three oxygen atoms are joined together.
It is constantly being made and destroyed in the stratosphere. This radiation can damage DNA, thereby leading to the formation of skin cancers. Chlorine compounds It has been known for some time that man-made chlorine and bromine compounds can upset the balance of chemistry at high altitudes leading to a thinning of ozone. The chlorine compounds have been produced for use as refrigerants, aerosol sprays, solvents and foam blowing agents, while bromine-containing halons have been used in fire extinguishers. World governments have now moved to restrict their use.