• Air is one of five basic natural ingredients of life system and also an inexhaustible natural resource. It is very essential for the survival of all the living organisms on earth.

 

• Air is a mixture of different gases; nitrogen, carbon and oxygen are the major components.

 

• Besides, the  above mentioned gases, small quantities of hydrogen, ozone, Nobel gases, oxides of nitrogen & sulfur, carbon monoxide, other organic and inorganic gases, aerosols and particulates which are emitted by various sources are dispersed in the atmosphere through diffusion. 

 

• The normal composition of total volume of clean air present in atmosphere is as follows:

Nitrogen            78.084%

Oxygen             20.946%

Argon                 0.934%

Carbon dioxide     0.0314%

Methane             0.0002%

Hydrogen            0.00005%

Other gases        traces

• Atmosphere is a dynamic system that continuously receives a wide range of solids, liquids and gasses from both natural and anthropogenic sources. Further, introduction of chemicals, particulate matter, or biological materials harmful to human beings or other living organisms or which damage the natural environment cause pollution.

 

• The main cause of air pollution is the use of fossil fuels (coal, oil and natural gas) in transport, power generation, industry and domestic sectors. In addition the burning of biomass such as firewood, agricultural and animal waste also contributes to pollution levels.

 

• Air in the most Indian cities has become highly polluted and concentration of certain pollutants exceed prescribed limits of Central Pollution Control Board (CPCB).

 

• Pollution emission has direct and indirect effects on air quality with a wide range of impacts on human health, ecosystem, agriculture and materials.

 

• To gain an understanding of urban air pollution, it is necessary to understand the economic development context and the key factors which influence the emission of air pollutants (Dieter et al., 2008).  

 

References