Consider the following statements regarding mercury pollution : 1. Gold mining activity is a source of mercury pollution in the world. 2. Coal-based thermal power plants cause mercury pollution. 3. There is no known safe level of exposure to mercury. How many of the above statements are correct?

1. A. Only one
2. B. Only two
3. C. All three
4. D. None

Answer: C

Explanation

All three statements regarding mercury pollution are correct:
1. **Statement 1**: Artisanal and small-scale gold mining (ASGM) is a significant global source of mercury pollution. Mercury is used to extract gold from ore, and during the process, it is often released into the environment, including through burning, which vaporizes the mercury.
2. **Statement 2**: Coal contains trace amounts of mercury. When coal is burned in thermal power plants, mercury is released into the atmosphere as a pollutant, contributing to air and water contamination.
3. **Statement 3**: Mercury is a highly toxic heavy metal. Scientific and health organizations generally agree that there is no known safe level of exposure to mercury, especially for vulnerable populations, due to its severe neurotoxic and developmental effects.
This question addresses a critical environmental issue, often covered under pollution and environmental health in UPSC.