Air Pollution

 

Air Pollution

Air is one of the most important constituents of man’s environment it is calculated that man breathes about 22000 times a day inhaling about 16 kg of air by weight, Air is present everywhere and its entrance  from one place to another cannot be checked . Clean and pure air is very essential for the health and survival of man. Air is a mixture of various gases in a particular ratio. Whenever the ratio of these gases, foreign materials or if there is an addition of particulate substances, foreign materials or gases in the air which may be harmful, the air is said to be polluted.

Sources of Air Pollution

 There can be natural as well as man-made sources of air pollution Natural sources of air pollution

1.       Volcanic eruptions giving out ash and harmful gases

2.       Forest fires.

3.       Dust storms and tornados.

4.       Pollen, Fungal spores, decayed organic materials etc.

Man-made sources of air pollution

The man-made sources of air pollution include setting up of industries and plants and various activities that are given in the table.

Table: - Important Air-Pollution Sources and Emissions

	Category	Examples	Important Pollutants
1.	Fuel burning	Domestic Burning Thermal power Plants	Sulphur and  nitrogen oxides
2.	Crop Spraying	Pest and weed control	Chlorinated hydrocarbons, lead and arsenic
3.	Spray, painting solvent, extractions ,inks, solvent cleaning	Furniture and appliances dyeing, printing and chemical separations, dry cleaning	Hydrocarbons and other organic vapours
4	Ore preparation	Crushing grinding and screening	Uranium and beryllium dust, other particulates
5.	Nuclear device testing	Bomb explosions	Radioactive fallout
6.	Transportation	Car, trucks aero planes and railway	Carbon monoxide, nitrogen oxides, lead, smoke and organic vapours
7.	Waste recovery	Scrap metal yards. Rendering plants	Smoke, soot, odors Smoke, soot , organic varpours and metal funes.
8.	Chemical plants, industries	Petroleum refineries, fertilizers, cement, paper mills, ceramic, clay products, glass manufacture and refrigeration	Hydrogen sulphise, sulphur oxide, fluorides, organic vapours and dusts. CFC (chlorofluorocarbons)
9.	Metallurgical plants	Aluminium refineries steel plants	Metal fumes (lead and (zinc) fluorides and particulates