The earth’s atmosphere has been evolving over the billions of years and will continue to do so. This evolution takes place very slowly and in a balanced manner. However, in the twentieth century, the atmosphere has received a large amount of gases released due to human activities such as large-scale industrialization and invention of vehicles like cars, buses, engines, etc.
These emissions are disturbing delicate balance between the atmosphere, oceans, rocks and various organisms. Now let us find out what are the different pollutants in the atmosphere and also the various sources of these pollutants. The major sources of air pollution are given below:
1. Combustion of Fossil Fuels and Wood
Combustion of fossil fuels such as coal, petrol, kerosene, diesel, etc., and wood releases huge quantities of carbon dioxide into the atmosphere. It is estimated that the man in combustion of fossil fuels alone is releasing 6000 million tonnes of CO2 into the atmosphere each year. In addition to CO2, some poisonous gases such as carbon dioxide (CO), sulphur dioxide (SO2) and hydrocarbons are also released into the atmosphere.
2. Cultivation of Soil
The cultivation of soil releases large amount of carbon dioxide produced by bacteria. This activity of man releases about 2000 million tonnes of CO2 into the atmosphere.
3. Industrial Activities
Various factories including chemical industries discharge a number of poisonous gases like nitrous oxide (N2 O), carbon monoxide (CO), sulphur dioxide (SO2) into the atmosphere. Smoke released by these factories contains unburnt carbon and dust which are also main pollutants. Solid suspensions and dust are increasing in proportion in the atmosphere.