The world has changed a lot during the past hundred years. From the source of light in our homes to, the way we communicate. While some changes have improved the quality of life, others have affected adversely. Industrialisation and introduction of new technologies haven’t come without any cost. And the cost we pay is degraded environment. Pollution is one of the main side effects of growth.
Air pollution is the contamination of air by several pollutants like dust, harmful chemicals, smoke, etc.
It has harmful effects on human beings, plants, animals and the environment.
Air pollution can be classified in many ways, like according to origin, according to state of matter and according to sources.
The main sources of air pollution are automobile pollution, industrial air pollution, burning of garbage and brick kilns. Air pollution can be caused by the primary pollutants. Primary pollutants are emitted directly from the sources. They retain the same chemical form in the atmosphere in which they were emitted.
Vehicular exhausts in metropolitan cities account for:
75% of all Carbon Monoxide (CO)
45% of all hydrocarbons
40% of all oxides and
30% of all suspended particulate matter (SPM)
Water pollution is another major problem faced by the world today. Water pollution is caused by several sources, both natural and man-made.
Gases, soil, minerals, waste of animals, etc., are the natural elements causing water pollution. The major Man-made sources of water pollution are household detergents and sewage, industrial waste, offshore oil, drilling, oil spills, radioactive waste and thermal pollution.
Soil is one of the major resources. The main sources of soil pollution are industrial wastes, urban commercial and domestic waste, chemical fertilizers, bio medical waste, pesticides and weedicides.
Radioactive pollution is very harmful for living beings. Energetic radiations reaching the earth from outer space are radioactive in nature. But these are not much dangerous for organisms on the earth. The main man-made sources of radioactive pollution are X ray waste, nuclear weapon, atomic reactors and nuclear fuel and radioactive isotopes. Radioactive wastes from atomic reactors are hazardous to living organisms. Both nuclear fuel and coolants, used in atomic reactors spread radioactive pollution. Inert gases escape as vapours and pollute the environment. Radioactive wastes can harm the surroundings even if they are buried deep.