Causes of Air Pollution

We known about the composition of atmosphere, its major and minor constituents. The composition of atmosphere has remained the same for thousands of years. However, only in the last 100 to 200 hundred years some changes have occurred and their impact on the biosphere is alarming. The major constituents of air N₂, O₂ and inert gases that comprises about 99.9% have not changed. But some minor and trace constituents such as sulphur dioxide (SO₂), oxides of nitrogen N₂O, NO, NO₂ (NO_x) methane (CH₄) chlorofluorocarbons (CFCs) along with carbon dioxide (CO₂) in burnt hydrocarbon and suspended particulate matter (SPM) have increased. You know that these are the major air pollutants responsible for the deterioration of air quality.