UPSC Static Quiz – Environment : 6 July 2026

Solution: B

• Statement 1 is Correct. In-situ bioremediation treats contaminated soil or groundwater without removing it from the site. Indigenous or introduced microorganisms degrade pollutants under natural or enhanced conditions.
• Statement 2 is Correct. Electron donors such as lactate, molasses, or vegetable oil are commonly injected into contaminated aquifers to stimulate anaerobic microorganisms that degrade chlorinated hydrocarbons.
• Statement 3 is Incorrect. Excavation is a feature of ex-situ bioremediation. In-situ methods are specifically designed to treat contamination without excavation.

Solution: B

• Statement 1 is Correct. Radon-222 is a naturally occurring radioactive noble gas produced in the uranium-238 decay series. Uranium present in rocks, soils, and geological formations decays to radium-226, which subsequently decays to radon-222. Being a colorless, odorless, and chemically inert gas, radon can migrate through soil pores and rock fractures into buildings, where it may accumulate, particularly in enclosed spaces. Long-term exposure to elevated radon concentrations is a major cause of lung cancer after smoking.
• Statement 2 is Incorrect. Radon-222 primarily decays by emitting alpha particles, not beta particles. Alpha particles have high ionizing power but very low penetration and can be stopped by a sheet of paper or the outer layer of human skin. Beta particles are more penetrating and require denser shielding materials.
• Statement 3 is Incorrect. Indoor radon accumulation is generally highest in basements, crawl spaces, and ground-floor rooms, where the gas enters directly from the soil through cracks, joints, and utility penetrations. Good ventilation reduces radon concentration. Consequently, upper stories of well-ventilated buildings usually have much lower radon levels.
• Statement 4 is Correct. Nuclear waste vitrification is an established technique for managing high-level radioactive waste. In this process, radioactive materials are immobilized by incorporating them into a borosilicate glass matrix, which is highly durable, chemically stable, and resistant to leaching. The vitrified waste is then sealed in corrosion-resistant containers for long-term storage and eventual geological disposal.

Solution: B

• Statement I: Anthropogenic mercury emissions, particularly from coal-fired power plants, are a major source of environmental mercury. Once deposited into aquatic ecosystems, inorganic mercury is converted by microorganisms into methylmercury, a highly toxic organic form. Consequently, mercury pollution poses serious health risks to marine ecosystems, especially to top-level predators such as tuna, swordfish, sharks, and marine mammals.
• Statement II: Methylmercury is readily absorbed by aquatic organisms and is eliminated very slowly. As a result, it bioaccumulates within individual organisms over time and biomagnifies through successive trophic levels of the food chain. Apex piscivorous species therefore contain the highest mercury concentrations. This mechanism directly explains why top marine predators experience severe biological hazards.
• Hence, Relationship 1 is correct, because Statement II provides the scientific basis supporting Statement I.
• Statement III is incorrect. Unlike many organic pollutants, heavy metals are not biodegradable and cannot be metabolized into harmless substances by marine organisms. Instead, they persist in tissues for long periods and often accumulate to toxic levels. Therefore, Statement III directly contradicts the premise underlying Statement I that mercury pollution creates long-term ecological and biological risks.
• Hence, Relationship 2 is also correct.
• Relationship 3 is incorrect, because Statement III does not establish biological risk; rather, it incorrectly suggests that heavy metals become non-toxic over short timescales, which is contrary to established scientific understanding.

Solution: A

• Statement I is correct. The Forest (Conservation) Act (FCA), 1980, was enacted specifically to check the alarming rate of deforestation in the country. Its primary objective is to regulate the diversion of forest lands for non-forestry purposes. Section 2 of the Act explicitly states that no State Government or other authority shall make any order directing that any reserved forest shall cease to be reserved, or that any forest land may be used for any non-forest purpose, without the prior approval of the Central Government. This provision effectively curtails the unilateral power of State Governments to de-reserve or divert forest land, making central clearance mandatory.
• Statement II is correct. Originally, ‘Forests’ was a subject under the State List in the Seventh Schedule of the Constitution. However, the 42nd Constitutional Amendment Act of 1976 transferred the subject of ‘Forests’ from the State List to the Concurrent List. This was a landmark move that empowered both the Central and State Governments to legislate on matters related to forests.
• The placement of ‘Forests’ in the Concurrent List by the 42nd Amendment (Statement II) provided the constitutional basis and legislative competence for the Union Parliament to enact a law like the Forest (Conservation) Act, 1980 (Statement I).

Solution: B

• The Ramsar Convention is an intergovernmental treaty that provides the framework for the conservation and wise use of wetlands and their resources.
• Statement 1 is incorrect. The ‘Montreux Record’ is a register of Ramsar sites where changes in ecological character have occurred, are occurring, or are likely to occur due to human interference or pollution. However, while placing a site on the Record can help prioritize it for national and international conservation attention and can facilitate access to technical advice (like a Ramsar Advisory Mission), it does not make a country eligible for mandatory international financial assistance. Assistance is sought and provided based on requests and availability of funds, but it is not an automatic or mandatory entitlement upon listing.
• Statement 2 is correct. This statement accurately captures the essence of the ‘wise use’ principle, which is a cornerstone of the Ramsar Convention. The obligation of ‘wise use’ extends beyond the boundaries of designated Ramsar sites. Contracting parties commit to formulating and implementing their planning to promote the conservation of their listed wetlands and, as far as possible, the wise use of all wetlands in their territory. This reflects the understanding that the health of the entire wetland ecosystem network is crucial, not just a few protected sites.