Air pollution : Air pollution may be defined as “the presence of one or more contaminants such as fumes, dust, gases, mist, smoke, odour, smog or vapours in the outdoor atmosphere which is injurious to human, animal or plant life or which unreasonably interferes with the comfortable enjoyment of life and property.”
There are two types of air pollutants which cause air pollution :
(i) Primary air pollutants :
Natural pollutants- Bacteria, pollens, products of volcanic eruptions.
Aerosols- Dust, smoke, mist, fog.
Gases- CO2, CO, SOx, NOx, hydrocarbons etc.
(ii) Secondary air pollutants :
eg. Smog- mixture of smoke, fog, air and other chemicals.
Prevention of air pollution :
The following methods are used for the prevention of air pollution :
- Zoning.
- Control of air pollution by sources.
- Control of air pollution by using devices.
- Control of air pollution by means of stacks.
- Control of air pollution by growing vegetation.
