Question

How are the pollutants categorised on the basis of their existence in nature? Give two examples of each category?

Answer 1

Pollutants are categorises in mainly i.e. degradable and non- degradable pollutants, out of them non-degradable pollutants create problem of pollution, e.g. glass, plastics, pesticides, etc.
On the basis of existence in nature, pollutants are divided into two categories:

• Quantitative pollutants: These substances exist in nature but they act as pollutants when their concentration or quantity increases up to a critical level in the atmosphere, e.g., Carbon- dioxide, Nitrogen oxide, etc.
• Qualitative pollutants: These pollutants do not exist in the environment They are introduced into the environment through man’s activities, e.g., pesticides (DDT), chemical fertilizers, herbicides, etc.