The 100-year Global Warming Potential (GWP) of carbon dioxide, methane, and nitrous oxide relative to carbon dioxide are 1, 21, and 310 respectively.

• 1, 21, 310: According to standard IPCC reference values widely adopted in agricultural chemistry, carbon dioxide has a baseline of 1, methane has 21, and nitrous oxide has 310.
• 1, 310, 21: Inverts the values of methane and nitrous oxide.
• 21, 1, 310: Incorrect baseline value assigned to carbon dioxide.
• 310, 1, 21: Completely misassigns the warming potentials of all three gases.

Cadmium poisoning causes Itai-Itai disease in humans, leading to severe osteomalacia and kidney damage.

• Fluoride: Causes dental and skeletal fluorosis, characterized by mottling of teeth and bone calcification.
• Cadmium: Chronic ingestion through contaminated water and rice caused the famous Itai-Itai disease in Toyama Prefecture, Japan, resulting in brittle bones and agonizing joint pain.
• Zinc: An essential micronutrient whose excess causes gastrointestinal distress and interferes with copper metabolism.
• Lead: Toxic heavy metal causing saturnism, anemia, and central nervous system damage.

Under the Environment (Protection) Rules (1986) standards, the permissible limit for total dissolved inorganic solids in treated effluent discharged on land for irrigation is 2100 mg/L.

• 2100: Statutory general limit set by the Central Pollution Control Board (CPCB) for dissolved inorganic solids in effluents applied for crop irrigation.
• 1750: Specialized limit for specific manufacturing discharges, not the general standard.
• 1000: Recommended threshold for sensitive crops, not the statutory discharge standard.
• 600: Standard limit applicable to suspended solids in certain wastewater streams.

The Environment (Protection) Act, 1986 came into force across India on 19 November 1986.

• 19 November 1986: Enacted by Parliament under Article 253 following the Bhopal Gas tragedy, coming into force nationwide on 19 November 1986.
• June 1972: The United Nations Stockholm Conference on Human Environment (World Environment Day).
• 26 January 1992: Unrelated Republic Day date.
• December 1984: The tragic date of the Bhopal Gas Disaster that prompted this comprehensive legislation.