Air pollution refers to the introduction of particulate materials in the air, which have an adverse effect on the quality of air. The different components of air pollution can be categorised into following types:
1. Particulate matter: These substances are also referred to as suspended particulate matter (SPM) because of their ability to remain suspended in the air for long periods. Example includes aerosols.
2. Gaseous pollutants: These include gaseous substances that have the potential to deteriorate the quality of air. Examples of gaseous pollutants are hydrogen sulphide, carbon monoxide and sulphur dioxide.