The biosphere and ecosystem are self sustaining. Nature maintains a balance in land, water, air and the entire living organism in the world. Any imbalance in the biosphere is called environmental pollution.
The grand industrial development, the green revolution, the transport expansion, the rapid growth of cities and accidental management of natural resources have badly affected environ- mental balance. The pollution of air and water will soon reach a i point when no place on the earth will remain safe. Due to large i scale industrial and human settlements on grand scale many rivers have become gloomy and dark. The large scale industrial waters, and oil poured in the sea have started killing marine life.
Undoubtedly the modern technological development has been the main cause of polluting our air, ocean and rivers etc. It is a'' ' matter of great importance that our rivers are becoming dark. Fishes ''i are rotting on the sea shores. Trees are withering and cities are filled with foul air. Toxic chemicals are finding their way into our food. When the normal composition of air is changed, air becomes polluted.
The main causes of air pollutions are (i) combustion, (ii) manufacturing processes, (iii) agricultural activities, (iv) use of solvent and (v) nuclear energy programmes.
Combustion - Combustion can be described in three types — (i) Fuel burning, transportation and refuse burning. All these three kinds of combustion release several types of gases. These gases pollute air.
Various types of manufacturing processes - They also cause pollution. Chemical plants, metallurgical plants and plants for waste recovery come under this category. The polluted things released from these processes make the air unfit for human consumption. Agricultural activities are another source of air pollution. The use of chemical fertilizers and manures and burning of field waste pollute the atmospherically air.
Use of solvents - Several types of solvents is used in spray painting, polishing of furniture, dyeing, printing and dry-cleaning. The solvents produce hydrocarbons which pollute air.
Various measures may be adopted to control pollution. To trap smoke particles chambers should be made. Lofty smoke stakes should be built. Gases should be discharged through exhaust pipes higher in the air. Chemical industries should not be allowed to be set up on the banks of rivers Waste materials should be subjected to anti-pollution treatment.
In view of the great danger to mankind, many countries in the world have passed laws to prevent pollution. But it has been seen that anti-pollution laws are not being obeyed everywhere.
