Pure air is the need for human beings but in the modern world due to the pollution people are not able to get pure air. The polluted air has 78% Nitrogen, 21% Oxygen and 0.03% Carbon Dioxide. The mixture of other gases has been added in the pure air such as Methane, Ozone, Methane and Water Vapours in small quantities. When the air has affected with the harmful substances or gases such as Sulfur Dioxide, Carbon Monoxide, and particular matter then the air is said to be polluted.
