Ozone is a gas that present in the form of layer in Stratosphere. It is 20-30 Km above from the earth. It absorbs most of the harmful ultraviolet radiation. It is the friend of earth because it shields most of the UV radiation and does not allow them to pass earth. In 1970 it was discovered that man made ozone depleting substances (ODS) such as Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and methyl bromide destroys the ozone molecule in stratosphere. There is a variety of applications of (CFCs) such as Propellant in aerosol spray 2) Manufacturing of plastic 3) Cleanser of electronic equipment. These chemicals forms hole in ozone layer. Now in each year this hole is getting bigger and bigger like an infection that grows more and more virulent. This hole now measures 9 million square miles like the size of North America.
If this ozone is depleted then more UV will reach the earth. Exposure of higher amounts of UV radiation have serious impacts on human being, animals and plants. Ozone depletion affects the climate and climate change affects ozone.
In humans it causes skin and eye diseases because these parts are mostly exposed to UV radiation. It causes skin cancer sunburn and premature aging of the skin. Cataracts ( a clouding of the lens) is the major cause of blindness is due to exposure of eyes to UV radiation. Overexposure of UV radiation also suppress proper functioning of immune system and reducing the skin ability to protect against invaders.
In plants, UV radiation adversely affects the flowering and photosynthesis that finally results into decrease in agricultural production. It enhances the evaporation rate through stomata and moisture content of the soil and this condition adversely affects the growth and development of plants. Ozone reduction adversely affects the weather pattern which in turns affects the crop production
It effects on the efficiency of cyanobacteria that resides in the roots of rice and helps in retention of nitrogen
It also damages the marine life by destroying it on the early stages of development. It also observed that population of salamanders is reducing due to UV radiation reaching on earth. There is loss of biodiversity in rivers, oceans and lakes. Food chain of aquatic life also disturbed by decrease in plankton. Plankton are the first vital step in aquatic food chains.
UV radiation has also damages the fabrics, pipes, paints, rubber, plastic and other construction material on earth
It is the challenge for international community to stop the expanding of ozone hole and returned to the level of 1980. They have to take following steps for its control
1. Banning the production of ozone depleting substances in industries
2. Banning the use of ozone depleting substances
3. Creating awareness among people about these substances through conferances, print and electronic media
4. Replace the use of these chemicals with other alternative chemicals
5. Plugging the ozone hole by injecting alkane or propane into atmosphere trough large aircrafts. The propane have affinity to react with ozone and destroy the chlorine atoms
Written By: ZafarUllah, University Of Agriculture Faisalabad
Department of Plant Breeding and Genetics
Cell # 03360746430
52-D Ayyub Hall, University of Agriculture, Faisalabad
CNIC # 32402-2643305-3