The contamination of air with harmful substances is called air pollution or atmospheric pollution.It is very comman nowadays.Any substance that pollutes something is called pollutant.Oxides of sulphur (like SO2), nitrogen, carbon monoxide, heavy metals li Pb and Hg in air and particulate matter are very well known air pollutants.The sources are as follows-
1.Causes health problems in human beings. It also has adverse effects on plants.
2.Increases the amount of greenhouse gases like carbon monoxide and carbon dioxide in the air.
3. Acid rain, which causes large scale damage.