UPSC CSE Prelims
Soil Pollution Previous Year Questions (PYQs)

Detailed Explanation:

Answer: Option 1 — pesticides in agriculture

Carbofuran, methyl parathion, phorate, and triazophos are highly toxic organophosphate and carbamate pesticides used in agriculture. These chemicals are viewed with apprehension due to their severe toxicity to humans, non-target organisms, and the environment, leading to recommendations for their ban or phase-out by the Anupam Verma Committee in India.

📝 Short Notes: Hazardous Pesticides in India

• Organophosphates and Carbamates: These are two major classes of chemical pesticides that inhibit acetylcholinesterase enzyme, causing neurotoxic effects in pests and potentially in humans.
• Carbofuran: A carbamate insecticide banned in many countries; highly toxic to birds, fish, and mammals; used for soil and foliar treatment.
• Methyl Parathion: An organophosphate insecticide with extreme acute toxicity; banned or restricted globally due to human poisoning cases.
• Phorate: A systemic organophosphate insecticide; extremely hazardous with high dermal and oral toxicity.
• Triazophos: An organophosphate insecticide; moderately to highly toxic with environmental persistence concerns.
• Anupam Verma Committee (2013): Reviewed 66 pesticides banned abroad but used in India; recommended banning 13 and restricting others, leading to regulatory action by the Ministry of Agriculture.
• Government Action: Progressive banning and phase-out of hazardous pesticides to promote safer agricultural practices and protect public health and environment.

Detailed Explanation:

❌ Statement 1 – Incorrect: Excessive nitrogenous fertilizers suppress nitrogen-fixing microorganisms because abundant soil nitrogen reduces their competitive advantage and metabolic activity.

✅ Statement 2 – Correct: Nitrogenous fertilizers (especially ammonium-based) undergo nitrification, releasing H⁺ ions that increase soil acidity.

✅ Statement 3 – Correct: Excess nitrates (NO₃⁻) are highly water-soluble and leach into groundwater, causing nitrate contamination and eutrophication of water bodies.