Air Pollution is the presence of one or more pollutants like dust, smoke etc, in the atmosphere, in quantities and duration as to be injurious to health of men, plant or animal life or to property which interfere with their comfort.
Air Pollutants are broadly classified into two categories: (i) Primary pollutants and (ii) Secondary pollutants. Primary pollutants are those that are emitted directly from sources such as Smoke, Dust, Fumes, S02, Oxides of Nitrogen, CO, C02, etc. Secondary pollutants are those that are formed in die atmosphere by chemical interaction among primary pollutants and atmospheric constituents. Ozone, PAN (Peroxy acetyl nitrate), Ketones, aldehydes, are some secondary pollutants.
Sulphur dioxide produced through the burning of coal, causes acid rain and respiratory problems. Nitrogen oxides and volatile hydrocarbons from vehicular emissions combine to form photochemical smog (smoke + fog), which causes respiratory problems. Carbon monoxide from vehicle emissions restricts oxygen uptake, causes drowsiness, headache and death. Carbon dioxide produced during the burning of coal enhances global warming. Chlorofloro carbons (CFC) used in refrigeration, air-conditioning and in industries destroy the ozone layer.
