The poisonous and harmful substances which contaminate or infect the air are called air pollutants. Air is the mixture of different gases in the environment, polluted by different human activities. Air is very important for the existence of lifecycle on earth. Air is present all around the earth's surface. It is also present in soil and water, due to which living beings can breathe inside the soil and water. Everybody needs air; it is needed for living organisms to remain healthy and safe in the environment. Many sources pollute the air, in these sources, including natural (forest fire, Volcanic ash, dust particles, etc.) are polluting the air very badly. In human activities, many sources are the origins of air pollution like smoke from vehicles, waste of crops burned, oxides of Sulphur, carbon, and nitrogen. Poisonous gases produced during the decomposition of organic matter and particulate matter like soot, pollens, metallic compounds (compound of lead), Etc., also pollute the air.