What are the different types of pollutants?

 The different types of pollutants are:

• Primary Pollutants: These are the pollutants that are emitted directly from the sources such as volcanic eruptions, combustion of fossil fuel, etc. These include nitrogen oxide, sulphur oxide, etc.
• Secondary Pollutants: These are the pollutants that are not directly emitted from the sources but are formed when primary pollutants react in the atmosphere. For eg., ozone.