DDT belongs to the category of
- Anon-persistent pollutants
- Bsecondary air pollutants
- Cprimary air pollutants
- Dpersistent pollutantsCorrect
Solution
Concept
DDT is a non-biodegradable pesticide that stays in the environment for a long time.
Step-by-step solution
1. DDT is a chlorinated pesticide (organochlorine). 2. Microbes cannot easily break it down. It is non-biodegradable. 3. It stays in soil and water for many years and builds up in food chains (biomagnification). 4. So DDT is a persistent pollutant. Answer is (D).
Explanation
DDT does not break down easily in nature. It stays for many years and collects in the fat of animals and humans. So it is called a persistent pollutant.
Why the other options are wrong
A: Non-persistent pollutants break down quickly, but DDT does not. B: Secondary air pollutants (like ozone and PAN) form in air by chemical reactions. DDT is not formed this way. C: DDT is a pesticide found mainly in soil, water and food. It is not classed as a primary air pollutant.
Shortcut
Non-biodegradable pesticide means persistent pollutant.
Common mistake
Picking 'primary air pollutant' because DDT is sprayed into the air.
Correct answer: D) persistent pollutants