UPSC CSE Prelims
Question 99
Consider the following statements regarding mercury pollution :
- Gold mining activity is a source of mercury pollution in the world.
- Coal-based thermal power plants cause mercury pollution.
- There is no known safe level of exposure to mercury.
How many of the above statements are correct?
View correct answer and explanation
Correct answer: B
Correct Option: B (Only two)
Explanation: Mercury pollution arises from artisanal gold mining and coal combustion. The blanket claim that no mercury exposure level is known to be safe is not accepted as correct by the supplied key.
Statement / Pair / Item-wise Analysis:
1. Correct/True - Mercury amalgamation in artisanal gold mining releases mercury to air, soil and water.
2. Correct/True - Coal contains trace mercury released during burning at thermal power plants.
3. Incorrect/False - The categorical “no known safe level” statement is overly broad across compounds, routes, duration and dose; risk thresholds depend on exposure.
Option-wise Analysis:
A. Incorrect-it counts 1, but items 1, 2 qualify, giving 2.
B. Correct-exactly 2 of the 3 listed items satisfy the condition.
C. Incorrect-it counts 3, but only 2 qualify; item(s) 3 do not.
D. Incorrect-it counts 0, but items 1, 2 qualify, giving 2.
Review note: Caution: health agencies emphasize that mercury can cause harm at very low exposure, especially methylmercury. The absolute phrasing and key treatment of statement 3 merit expert/source review.