There are many other sources of air pollution which are directly related to man’s activities. Nitrogen oxide emitted from the supersonic aeroplanes is the main destroyer of ozone layer.
Nitrogen oxides convert 60-70 percent of ozone produced back to oxygen. As we are aware, the amount of chemical fertilizers used for our agricultural activities is increasing day by day which adversely affect the nitrogen cycle.
As a result the nitrogen oxide escapes from the ground and is injected into the atmosphere and damages a part of the ozone layer. Now days, as a result of combustion of fossil fuels in the factories, a lot of nitric oxide is produced which combines with smoke to produce smog.
During the last few decades the supersonic jets have added to the water vapour content of the stratosphere which in turn produces particulates. Another source of man-made atmospheric pollution is hydrocarbon.
More than 50 percent of the atmospheric hydrocarbon pollution comes from automobiles. Industries also contribute to the hydrocarbon pollution, though only 25 percent thereof. Hydrocarbon emission contributes to air pollution directly and to smog indirectly through the reactions between hydrocarbons and other constituents of the atmosphere.
Hydrocarbons are organic compounds comprising hydrogen and carbon. Hydrocarbons constitute a larger part of coal, petroleum, petroleum derivatives and similar products. Methane, the smallest among the hydrocarbons is also called “marsh gas” which is a colourless, odourless, tasteless and non-poisonous but highly inflammable gas.
It is sometimes produced by the decay of organic materials in swamps. Ethylene is another hydrocarbon which is produced by ripening fruits and other micro-organisms. It is highly toxic to plants.