Correct Answer - Option 3 : Ozone
Explanation
Primary pollutants: Pollutants that are emitted directly from either natural events or from human activities are called primary pollutants.
The natural events are dust storms; volcano etc and human activities can be emission from vehicles, industrial wastes.
About 90% of global air pollution is constituted by five primary pollutants. These are
1. Carbon oxides (CO and CO2)
2. Nitrogen oxides
3. Sulphur oxides
4. Hydrocarbons
5. Particulate matter
6. Suspended particulate matter (SPM).
Secondary pollutants: Primary pollutants when reacting with each other or from basic components of air, forms a new pollutant called secondary pollutants.
Different types of secondary pollutants include:
1. Ozone (O3)
2. Sulfuric acid (H2SO4) and nitric acid (component of acid rain)
3. Nitrogen dioxide (NO2)
4. Peroxyacyl nitrates (PAN)
