Environmental Pollution Control Acts & Standards GK Questions & Answers
India's environmental legislative architecture evolved following the 1972 United Nations Stockholm Conference on Human Environment, beginning with the Water (Prevention and Control of Pollution) Act, 1974, which established the Central Board for the Prevention and Control of Water Pollution (later renamed Central Pollution Control Board or CPCB). This was succeeded by the Air (Prevention and Control of Pollution) Act, 1981, amended in 1987 to categorize noise under air pollutants. In the wake of the Bhopal Gas Tragedy (December 1984, involving methyl isocyanate release), Parliament enacted the Environment (Protection) Act (EPA), 1986 under Article 253 to implement Stockholm decisions as an umbrella legislation empowering the Union Government to coordinate state and central pollution authorities, regulate industrial emissions, and notify statutory waste management rules (Hazardous, Biomedical, Solid, and E-Waste). The National Green Tribunal (NGT) Act, 2010 established specialized environmental judicial tribunals pursuant to Article 21's fundamental right to a healthy environment, replacing the National Environment Tribunal Act 1995. CPCB enforces National Ambient Air Quality Standards (NAAQS covering 12 pollutants) and the National Air Quality Index (AQI), which calculates pollution severity across six categories based on 8 key monitored pollutants: PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb.
High-yield conceptual summaries for competitive exams and rapid revision.
The Environment (Protection) Act, 1986 serves as umbrella legislation enacted under Article 253 following the 1984 Bhopal Gas Tragedy to implement decisions of the 1972 UN Stockholm Conference.
The Central Pollution Control Board (CPCB) was constituted in September 1974 under the Water (Prevention and Control of Pollution) Act, 1974, and entrusted with powers under the Air Act, 1981.
The Air (Prevention and Control of Pollution) Act, 1981 was amended in 1987 to incorporate noise pollution within the definition of air pollutants under Section 2(a).
The National Air Quality Index (AQI) monitors 8 criteria pollutants: PM10, PM2.5, Nitrogen Dioxide (NO2), Sulphur Dioxide (SO2), Carbon Monoxide (CO), Ozone (O3), Ammonia (NH3), and Lead (Pb).
The National Green Tribunal (NGT), established under the NGT Act, 2010 with Principal Bench in New Delhi, adjudicates civil environmental disputes within 6 months, guided by the principles of Sustainable Development, Precautionary Principle, and Polluter Pays Principle.
Showing 25 Curated Questions216 Total in Bank
1ID: GK-ENV-00108
mediumPollution Greenhouse Gases
The "Biochemical Oxygen Demand" (BOD) laboratory test measures what parameter of water pollution?
Verified Explanation
High BOD values (e.g. raw sewage > 300 mg/L) indicate heavy organic pollution that rapidly depletes river oxygen, suffocating aquatic fish populations.
2ID: GK-ENV-00617
mediumPollution & Greenhouse Gases
Biochemical Oxygen Demand (BOD) is a standard water pollution metric that measures:
Verified Explanation
BOD (specifically BOD5 at 20 °C) measures the milligrams of dissolved oxygen needed by aerobic biological organisms to break down organic material present in a given water sample; higher BOD indicates heavier sewage pollution.
3ID: GK-ENV-00071
easyPollution Greenhouse Gases
What is the air quality metric "PM2.5" referring to in atmospheric pollution monitoring?
Verified Explanation
PM2.5 particles from vehicle exhaust, power plants, and crop burning pose severe health risks, causing cardiovascular disease, lung cancer, and asthma.
4ID: GK-ENV-00164
easyPollution & Greenhouse Gases
What does the air quality metric 'PM2.5' specifically measure in ambient atmospheric pollution?
Verified Explanation
PM2.5 refers to microscopic atmospheric particulate matter with aerodynamic diameters ≤2.5 microns, which can penetrate deep into human bronchioles and alveoli causing cardiovascular and pulmonary damage.
5ID: GK-ENV-00194
hardPollution & Greenhouse Gases
Photochemical smog (Los Angeles-type smog) is an oxidizing secondary atmospheric pollution formed by the ultraviolet-driven reaction of solar radiation with:
Verified Explanation
Photochemical smog forms on warm sunny days when sunlight photolyzes NO2 into NO and reactive atomic oxygen, which combines with O2 to form ground-level ozone (O3) and reacts with VOCs to produce PAN and acrolein.
6ID: GK-ENV-00198
hardPollution & Greenhouse Gases
In aquatic pollution monitoring, standard 5-day Biochemical Oxygen Demand (BOD5) measures the amount of dissolved oxygen consumed by aerobic microorganisms to:
Verified Explanation
BOD5 measures milligrams of O2 consumed per liter of water sample by aerobic heterotrophs at 20°C over 5 days; pure drinking water has BOD < 1 mg/L, while heavily polluted domestic sewage exceeds 100-400 mg/L.
7ID: GK-ENV-00235
mediumPollution & Greenhouse Gases
The standard Biochemical Oxygen Demand (BOD5) test determines wastewater pollution levels by measuring:
Verified Explanation
BOD measures the dissolved oxygen (in mg/L) required by aerobic biochemical microorganisms to oxidize biodegradable organic matter in a water sample over 5 days at 20°C.
8ID: GK-ENV-00284
mediumPollution & Greenhouse Gases
What type of air pollution is formed in the atmosphere on sunny days when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react under ultraviolet sunlight?
Verified Explanation
Photochemical smog forms when sunlight drives reactions between NOx and VOCs, producing secondary pollutants including ground-level ozone (O3) and peroxyacetyl nitrate (PAN).
9ID: GK-ENV-00304
easyPollution & Greenhouse Gases
What standardized numerical index (ranging from 0 to 500) is used by environmental protection authorities to report daily ambient air pollution to the public?
Verified Explanation
The Air Quality Index (AQI) converts monitored concentrations of critical pollutants (PM2.5, PM10, NO2, SO2, CO, O3) into six color-coded categories (Good to Severe/Hazardous) to inform public health actions.
10ID: GK-ENV-00499
mediumPollution & Greenhouse Gases
What type of environmental pollution is responsible for Minamata disease, a neurological syndrome first discovered in Japan in 1956?
Verified Explanation
Minamata disease is severe mercury poisoning caused by industrial release of methylmercury into Minamata Bay by the Chisso Corporation, which bioaccumulated in shellfish and fish eaten by the local population.
11ID: GK-ENV-00524
hardPollution & Greenhouse Gases
What is the primary industrial pollution process responsible for Itai-Itai disease, which caused severe osteomalacia and renal failure in Toyama Prefecture, Japan?
Verified Explanation
Itai-Itai disease was caused by mass cadmium poisoning released by the Mitsui Mining and Smelting Co. into the Jinzu River basin in Toyama Prefecture, Japan, causing severe renal tubular dysfunction and painful bone softening.
12ID: GK-ENV-00597
easyPollution & Greenhouse Gases
Minamata disease, a severe neurological syndrome first identified in Minamata Bay, Japan, is caused by industrial pollution of:
Verified Explanation
Minamata disease was caused by the release of methylmercury in industrial wastewater from the Chisso Corporation chemical plant, which bioaccumulated in fish and shellfish eaten by local populations.
13ID: GK-ENV-00612
mediumPollution & Greenhouse Gases
Itai-itai disease, characterized by severe painful osteomalacia (softening of bones) and renal dysfunction, was caused by mass environmental pollution of which toxic heavy metal?
Verified Explanation
Itai-itai disease ('it hurts-it hurts' disease) in Toyama Prefecture, Japan, was caused by cadmium poisoning released by mining companies into the Jinzū River basin, contaminating irrigated rice paddies.
14ID: GK-ENV-00424
easyPollution & Greenhouse Gases
What parameter is used as a standard measure of organic water pollution by calculating the amount of dissolved oxygen consumed by microorganisms to decompose organic matter?
Verified Explanation
Biochemical Oxygen Demand (BOD) measures the amount of dissolved oxygen required by aerobic biological organisms to break down organic material present in water.
15ID: GK-ENV-00055
easyPollution Greenhouse Gases
What environmental phenomenon occurs when sulfur dioxide (SO2) and nitrogen oxides (NOx) react with water vapor in the atmosphere to form acidic precipitation?
Verified Explanation
Acid rain forms dilute sulfuric acid (H2SO4) and nitric acid (HNO3), damaging forests, acidifying aquatic ecosystems, and corroding limestone structures.
16ID: GK-ENV-00056
easyPollution Greenhouse Gases
What are tiny plastic particles less than 5 millimeters in size that contaminate oceans, freshwater, and marine food webs called?
Verified Explanation
Microplastics originate from degraded plastic debris, synthetic clothing fibers, and microbeads in cosmetics, bioaccumulating across food chains.
17ID: GK-ENV-00061
easyPollution Greenhouse Gases
Which clean renewable energy source converts radiant sunlight directly into electricity using the photovoltaic effect in semiconductor solar cells?
Verified Explanation
Solar PV systems utilize silicon p-n junctions to absorb photons and excite electrons, generating direct current (DC) electricity with zero operating emissions.
18ID: GK-ENV-00062
easyPollution Greenhouse Gases
Which renewable energy technology harnesses the kinetic energy of moving air masses using large three-bladed rotating aerodynamic turbines?
Verified Explanation
Wind turbines convert the kinetic energy of wind into mechanical rotary power that turns a generator to produce grid-scale alternating current (AC) electricity.
19ID: GK-ENV-00065
easyPollution Greenhouse Gases
What does the "3 Rs" waste hierarchy rule stand for in sustainable waste management and circular economy?
Verified Explanation
The 3 Rs hierarchy prioritizes minimizing waste generation first (Reduce), reusing materials repeatedly (Reuse), and processing waste into new materials (Recycle).
20ID: GK-ENV-00068
easyPollution Greenhouse Gases
Which renewable energy source utilizes the natural gravitational potential energy of falling or flowing water stored in elevated dams to spin turbines?
Verified Explanation
Hydropower is the world's largest single source of renewable electricity, providing flexible base-load and pumped-storage grid stabilization.
21ID: GK-ENV-00074
easyPollution Greenhouse Gases
Which renewable energy harnesses thermal heat energy naturally generated and stored within the Earth's sub-surface crust and magma mantle?
Verified Explanation
Geothermal power plants tap underground reservoirs of steam and hot water (e.g. in Iceland, the Geysers in California) to drive electric turbines.
22ID: GK-ENV-00077
easyPollution Greenhouse Gases
What is "Eutrophication" in freshwater lakes and rivers, caused by excessive runoff of agricultural nitrogen and phosphorus fertilizers?
Verified Explanation
Decomposing algae consume dissolved oxygen creating "dead zones", severely disrupting aquatic food chains and water quality.
23ID: GK-ENV-00080
easyPollution Greenhouse Gases
What is "Biogas", produced through the anaerobic digestion of organic biodegradable wastes (such as cattle dung, food waste, and sewage sludge)?
Verified Explanation
Biogas provides clean cooking fuel and decentralized rural electricity, producing organic nutrient-rich slurry digestate for organic farming.
24ID: GK-ENV-00083
easyPollution Greenhouse Gases
What is "Biomagnification" (Biological Magnification) in environmental ecotoxicology?
Verified Explanation
Because top predators (like eagles, tuna, and humans) consume many lower-trophic organisms, lipophilic toxins accumulate to dangerous lethal concentrations.
25ID: GK-ENV-00086
easyPollution Greenhouse Gases
What is "Green Hydrogen" and how is it produced with zero direct carbon emissions?
Verified Explanation
Unlike Grey (fossil gas) or Brown (coal) hydrogen, Green Hydrogen uses renewable electricity to split water (2H2O → 2H2 + O2) with zero carbon footprint.