Question 62 from UPSC CSE 2023 - Environme nt

Question

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?

IASCODEX · Accepted Answer

Correct Option: C. All three

Strategy: Evaluate each statement independently by checking against well-known environmental and health themes. Both gold mining and coal-based thermal power plants are standard examples cited for mercury pollution. The phrase 'no known safe level' is a clear indicator--such expressions are used for highly toxic substances. All statements match established scientific consensus.

Key Info: Mercury (Hg) is a naturally occurring heavy metal, highly toxic to humans and wildlife, especially the nervous, digestive, and immune systems.

- Gold mining, particularly artisanal and small-scale gold mining (ASGM), is the largest global source of anthropogenic (human-caused) mercury emissions. Mercury is used to extract gold from ore, resulting in significant environmental release, contamination of river systems, and entry into food chains.

- Coal-based thermal power plants are major stationary sources of mercury emissions. Mercury present in coal is released during combustion and enters the atmosphere as elemental mercury or various compounds, contributing to regional and global mercury pollution. India and China are among the leading countries in this category due to large coal usage.

- Mercury is classified by agencies such as the World Health Organization (WHO) and US Environmental Protection Agency (EPA) as a substance for which no exposure level is considered safe. Even low doses are hazardous, especially for pregnant women, infants, and young children, due to its neurotoxic effects. Chronic exposure leads to neurological and developmental damage.

- Mercury pollution is addressed globally by the Minamata Convention on Mercury (2013), a treaty aiming to protect human health and the environment from emissions and releases.

- Mercury accumulates in food chains, particularly in aquatic systems, leading to high concentrations in fish and seafood.

- Natural sources of mercury include volcanic eruptions and weathering of rocks, but anthropogenic activities are the primary cause of recent increases in the environment.

IASCODEX · Answer

Option A: Only one

IASCODEX · Answer

Option B: Only two

IASCODEX · Answer

Option D: None of the above statements is correct

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?

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?