Question

Given below are two statements, one is labeled as Assertion (A) and the other one is labeled as Reason (R).
Assertion (A) : The organochlorine pesticides accumulate in the fatty tissues in the human body.
Reason (R) : Organochlorine pesticides are chemically unstable and hydrophobic.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both (A) and (R) are correct and (R) is the correct explanation of (A).
• B. Both (A) and (R) are correct and (R) is not correct explanation of (A).
• C. (A) is correct but (R) is not correct.
• D. (A) is not correct but (R) is correct.

Hint:

Due to their high chemical stability and bioaccumulation in food chains, most organochlorine pesticides (such as DDT) have been banned or heavily restricted worldwide under the Stockholm Convention on Persistent Organic Pollutants (POPs).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Organochlorine pesticides (such as DDT, BHC, and Endosulfan) are synthetic organic compounds containing chlorine atoms.
Their physical and chemical properties determine their persistence and toxicity in the environment and food chains.

Step 3: Detailed Explanation:
Let us evaluate both statements individually:
- Assertion (A): Organochlorine pesticides are highly soluble in fats and lipids (lipophilic) and have extremely low solubility in water (hydrophobic).
When animals or humans ingest these compounds, they dissolve and accumulate in adipose (fatty) tissues rather than being excreted in water-based urine. This leads to bioaccumulation and biomagnification up the food chain.
Therefore, Assertion (A) is correct.
- Reason (R): This statement asserts that organochlorine pesticides are chemically unstable and hydrophobic.
While they are indeed hydrophobic, organochlorines are highly chemically stable and resistant to photolytic, biological, and chemical degradation.
This high chemical stability is the main reason they persist in the environment for decades after application.
Because the statement claims they are "chemically unstable," Reason (R) is incorrect.
Thus, (A) is correct, but (R) is incorrect.

Step 4: Final Answer:
The correct option is (C) as (A) is correct but (R) is not correct.