Consider the following statements:
- 1.Coal ash contains arsenic, lead and mercury.
- 2.Coal-fired power plants release sulphur dioxide and oxides of nitrogen into the environment.
- 3.High ash content is observed in Indian coal.
Which of the statements given above is/are correct?
Answer & explanation
Answer: (d) 1, 2 and 3
All three statements are correct: coal ash carries toxic trace metals such as arsenic, lead and mercury, coal-burning power plants emit sulphur dioxide and nitrogen oxides, and Indian coal is high in ash.
- ✓ 1. Coal and its fly ash hold toxic trace elements; the US Geological Survey names arsenic, selenium, lead and mercury among those tested in fly ash.
- ✓ 2. CPCB's standards for coal-based thermal power plants set limits for sulphur dioxide and oxides of nitrogen in the flue gas, because burning coal releases both.
- ✓ 3. The Ministry of Coal states that coal produced in India generally has 25 to 45 per cent ash, against 10 to 20 per cent for imported coal, which is why washing of coal is promoted.
Remember · Coal power means SO2 and NOx in the air and ash laden with arsenic, lead and mercury on the ground; Indian coal is high in ash.
📘 Read it in NCERT: Class 11 Indian Economic Development, Ch 7 (practise this chapter)
Sources
- US Geological Survey Fact Sheet 163-97: Radioactive Elements in Coal and Fly Ash ↗ “Standardized tests of the leachability of toxic trace elements such as arsenic, selenium, lead, and mercury from fly ash show that the amounts dissolved are sufficiently low”
- CPCB, Thermal Power Plants: Environmental Regulations (emission standards for coal-based plants) ↗ “Sulphur Dioxide ( SO2) 600 mg/Nm3 (Units Smaller than 500MW capacity units) 200 mg/Nm3 (for units having capacity of 500MW and above) Oxides of Nitrogen ( NOx) 600 mg/Nm3”
- PIB, Ministry of Coal: High Ash content (3 January 2018) ↗ “Ash content of coal produced in the country is generally 25 to 45 % whereas average ash content of imported coal varies from 10 to 20 %.”
- NCERT Class 11 · Indian Economic Development, Chapter 7 “Thermal power plants emit large quantities of carbon dioxide which is a green house gas. It also produces fly ash which, if not used properly, can cause pollution of water bodies, land and other components of the environment.”
Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·