Depletion of Ozone Layer (Ozone Hole)

The ozone layer present in the earth's atmosphere prevents the entry of sun's harmful ultraviolet (UV) radiations reaching the Earth's surface. Industrial use of chemicals called chlorofluorocarbons (CFCs) in refrigeration, air conditioning, cleaning solvents, fire extinguishers and aerosols (spray cans of perfumes, insecticides, medicines) damage the ozone layer.

Chlorine present in the CFCs on reacting with ozone (O3) layer splits the ozone molecule to form oxygen (O2). Thus, amount of ozone gets reduced and cannot prevent the entry of UV radiations. There has been a reduction by 30-40% in the thickness of the ozone umbrella or shield over the Arctic and Antarctic regions. This thinning of ozone layer is called ozone hole.

The depletion of ozone layer may lead to the following hazards:

  • Sunburn, fast ageing of skin, cancer of skin, cataract (opaqueness of eye lens leading to loss of vision), cancer of the retina (sensitive layer of the eye on which the image is formed)
  • Genetic disorders
  • Reduced productivity at sea and forests

The damage to the ozone layer can be prevented by:

  • Reducing the consumption of CFCs by adopting alternative technologies (substituting air conditioning gases by non-CFCs)
  • Discouraging the use of aerosol containing spray cans