Environmental Pollution

1. 'Ringelmann scale' is used to measure density of: UPPSC 2021

(a) Smoke

(b) Polluted water

(d) Noise

Ans. (a)

Exp:

The Ringelmann scale is a scale used to measure the apparent density or opacity of smoke emitted from stacks or chimneys. Ringelmann No. 0 represents clear emissions, while higher numbers indicate progressively greater opacity.

Hence, option (a) is the correct answer.

2. In which of the following years, the Environment (Protection) Act was passed by the Government of India? UPPSC 2021

(a) 1982

(b) 1986

(d) 1992

Ans. (b)

Exp:

The Environment (Protection) Act was enacted by the Parliament of India in 1986 in the wake of the Bhopal Gas Tragedy (1984), which highlighted the need for comprehensive environmental safety laws.

Constitutional Basis: It was enacted under Article 253 of the Constitution of India to implement decisions made at the 1972 United Nations Conference on the Human Environment (Stockholm Conference).

Hence, option (b) is the correct answer.

3. Which of the following is an indicator of air pollution? UPPSC 2021

(a) Puffballs

(b) Algae

(d) Moss

Ans. (c)

Exp:

Lichens are widely used as bioindicators of air pollution because they absorb water and dissolved substances directly from the atmosphere and are particularly sensitive to pollutants such as sulphur dioxide (SO₂) and other atmospheric contaminants.

Hence, option (c) is the correct answer.

4. Fly ash pollution is caused by: UPPSC 2021

(a) Oil refining

(b) Fertilizer industry

(d) Mining

Ans. (c)

Exp:

Fly ash is a fine particulate byproduct generated primarily during the combustion of pulverized coal in coal-fired thermal power plants.

Hence, option (c) is the correct answer.

5. Dichloro-diphenyl-trichloroethane (DDT) is a: UPPSC 2022

(a) Non-pollutant

(b) Non-biodegradable pollutant

(d) Biochemical pollutant

Ans. (b)

Exp:

DDT (Dichlorodiphenyltrichloroethane) is a synthetic organochlorine chemical widely known as a non-biodegradable (or persistent) pollutant. Because DDT is lipophilic (fat-soluble) and insoluble in water, it accumulates in the fatty tissues of living organisms (bioaccumulation).

Hence, option (b) is the correct answer.

6. Photochemical smog always contains UPPSC 2022

(a) Phosphorus

(b) Ozone

(d) Aluminium ion

Ans. (b)

Exp:

Photochemical smog (also called Los Angeles smog) always contains ground-level Ozone (O3) as its primary oxidising constituent. In addition to ozone, photochemical smog typically contains peroxyacetyl nitrate (PAN), aldehydes, and nitrogen dioxide.

Hence, option (b) is the correct answer.

7. Match List-I with List-II and select the correct answer from the code given below the lists. UPPSC 2022

List-I (Sustainable Development Goal (SDG):

A. SDG 10

B. SDG 13

C. SDG 14

D. SDG 15

List-II (Related with):

1. Climate change

2. Life on land

3. Reduced inequalities

4. Life below water

Code:

(a) A-1, B-2, C-3, D-4

(b) A-2, B-1, C-4, D-3

(d) A-3, B-2, C-1, D-4

Ans. (c)

Exp:

A. SDG 10: Reduced Inequalities (3)

B. SDG 13: Climate Action / Climate Change (1)

C. SDG 14: Life Below Water (4)

D. SDG 15: Life on Land (2)

Hence, option (c) is the correct answer.

8. Which of the following materials is bio-degradable? UPPSC 2022

(a) Glass bottle

(b) Plastic cups

(d) Wool

Ans. (d)

Exp:

Wool is a natural protein fibre mainly composed of keratin and can be broken down by microorganisms under suitable environmental conditions. Hence, it is biodegradable.

Hence, option (d) is the correct answer.

9. Which country has natural arsenic water contamination? UPPSC 2022

(a) Sri Lanka

(b) Bangladesh

(d) Pakistan

Ans. (b)

Exp:

Bangladesh is recognized worldwide as the most severely affected country by naturally occurring (geogenic) arsenic contamination in groundwater.

Origin of Contamination: The high concentration of arsenic in the shallow tubewells of Bangladesh originates naturally from the mineral sediments washed down from the Himalayas through the Ganges-Brahmaputra river delta system.

Hence, option (b) is the correct answer.

10. According to the annual 'Frontier Report-2022' released by U.N. Environment Programme, which Indian city has become the second most noise polluted city of the World? UPPSC 2022

(a) Kota

(b) Moradabad

(d) Patna

Ans. (b)

Exp:

According to the Annual Frontier Report - 2022 (titled "Noise, Blazes and Mismatches") released by the United Nations Environment Programme (UNEP):

2nd Most Noise Polluted City: Moradabad in Uttar Pradesh, India, was ranked as the second most noise-polluted city globally, recording maximum noise levels up to 114 decibels (dB).

Hence, option (b) is the correct answer.

11. On which date Ozone Day is observed? UPPSC 2022

(a) October 2

(b) September 16

(d) January 30

Ans. (b)

Exp:

World Ozone Day (International Day for the Preservation of the Ozone Layer) is celebrated annually on September 16. It commemorates the signing of the Montreal Protocol on Substances that Deplete the Ozone Layer in 1987, a landmark international treaty designed to phase out the production and consumption of ozone-depleting substances (ODS) such as chlorofluorocarbons (CFCs).

Hence, option (b) is the correct answer.

12. Eco mark is given to a product which is: UPPSC 2022

(a) Un-adulterated

(b) Economically viable

(d) Rich in carbohydrate

Ans. (c)

Exp:

Eco Mark Scheme: Launched in 1991 by the Ministry of Environment, Forest and Climate Change (MoEFCC), the Eco Mark is a labeling standard issued by the Bureau of Indian Standards (BIS). An Eco Mark is awarded to consumer products that satisfy environmental criteria and quality standards, signaling minimal ecological impact throughout their lifecycle.

Hence, option (c) is the correct answer.

13. Which of the following is NOT a greenhouse gas? UPPSC 2022

(a) Argon

(b) Chlorofluorocarbon

(d) Carbon dioxide

Ans. (a)

Exp:

Argon is a noble, chemically inert gas that makes up about 0.93% of Earth's atmosphere. Because argon atoms are monatomic (single atoms), they cannot vibrate in ways that absorb infrared radiation (heat), making Argon a non-greenhouse gas.

Hence, option (a) is the correct answer.

14. The main purpose of 'Ganga Action Plan' project, launched in 1985, was

UPPSC 2022

(a) Make its water pollution free only

(b) Utilize the river water for irrigation only

(d) None of the above

Ans. (a)

Exp:

The Ganga Action Plan (GAP) was officially launched by then Prime Minister Rajiv Gandhi in June 1985 with the primary objective of pollution abatement—improving the water quality of the Ganga River by reducing pollution levels.

Hence, option (a) is the correct answer.

15. In the context of permissible noise level, match List-I with List-II and select the answer from the code given below the lists. UPPSC 2022

List-I (Area):

A. Residential area

B. Silent zone

C. Industrial area

D. Commercial area

List-II (Permissible Noise Level):

1. 50 dB

2. 55 dB

3. 65 dB

4. 70 dB

Code:

(a) A-2, B-1, C-3, D-4

(b) A-3, B-4, C-2, D-1

(d) A-1, B-2, C-3, D-4

Ans. (c)

Exp:

Under the Noise Pollution (Regulation and Control) Rules, 2000 issued by the Ministry of Environment, Forest and Climate Change (MoEFCC) in India, ambient air quality standards for noise during the day time are defined as:

Area / Zone	Code	Permissible Ambient Noise Level (Day Time)
Residential Area	A	55 dB
Silence Zone	B	50 dB
Industrial Area	C	75 dB (or *70 dB* as approximated in the question options)
Commercial Area	D	65 dB

Hence, option (c) is the correct answer.

16. According to the Environmental Protection Agency (EPA), which one of the following is the largest source of Sulphur dioxide emissions? [CSE - 2024]

(a) Locomotives using fossil fuels

(b) Ships using fossil fuels

(d) Power plants using fossil fuels

Ans. (d)

Exp:

According to the United States Environmental Protection Agency (EPA):

Power Plants Using Fossil Fuels (Largest Source): The single largest source of SO2 in the atmosphere is the combustion of fossil fuels (primarily coal and heavy fuel oil) by power plants and large industrial facilities.

Hence, option (d) is the correct answer.

17. Among the following crops, which one is the most important anthropogenic source of both methane and nitrous oxide? [CSE-2022]

(a) Cotton

(b) Rice

(d) Wheat

Ans. (b)

Exp:

Rice cultivation (specifically flooded paddy fields) is a major contributor to both methane (CH4) and nitrous oxide (N2O) emissions. Wheat, Cotton, and Sugarcane are grown under upland (aerated) soil conditions where anaerobic conditions do not persist long enough to produce significant methane.

Hence, option (b) is the correct answer.

18. Bisphenol A (BPA), a cause of concern, is a structural/key component in the manufacture of which of the following kinds of plastics? [CSE-2021]

(a) Low-density polyethylene

(b) Polycarbonate

(d) Polyvinyl chloride

Ans. (b)

Exp:

Bisphenol A (BPA) is an organic synthetic compound primarily used as a key chemical building block (monomer) in the production of polycarbonate plastics and epoxy resins. It can interfere with the body's endocrine system, impacting reproductive health, development, and metabolic function.

Hence, option (b) is the correct answer.

19. ‘Triclosan’, considered harmful when exposed to high levels for a long time, is most likely present in which of the following? [CSE-2021]

(a) Food preservatives

(b) Fruit-ripening substances

(d) Toiletries

Ans. (d)

Exp:

Triclosan is an antibacterial and antifungal agent widely added to consumer toiletries and personal care products.

Hence, option (d) is the correct answer.

20. Why is there a concern about copper smelting plants? [CSE-2021]

1. They may release lethal quantities of carbon monoxide into the environment.

2. The copper slag can cause the leaching of some heavy metal into environment

3. They may release sulphur dioxide as a pollutant.

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 2 and 3 only

(d) 1, 2 and 3

Ans. (b)

Exp:

While smelting produces some carbon dioxide and minor trace gases, it does not generate or release lethal quantities of carbon monoxide. Hence, statement 1 is not correct.

Copper slag is a solid waste byproduct containing residual heavy metals like arsenic, lead, cadmium, and nickel. Rainwater percolating through improperly dumped slag leaches these toxic metals into the surrounding soil and groundwater. Hence, statement 2 is correct.

Most copper ores (such as chalcopyrite) exist as sulfur compounds that release large amounts of sulfur dioxide (SO2) gas during high-temperature roasting. Hence, statement 3 is correct.

Hence, option (b) is the correct answer.

21. Why is there a great concern about the `microbeads' that are released into the environment? [CSE-2019]

(a) They are considered harmful to marine ecosystems.

(b) They are considered to cause skin cancer in children.

(d) They are often found to be used as food adulterants.

Ans. (a)

Exp:

Microbeads are tiny, solid plastic particles (usually made of polyethylene, polypropylene, or polystyrene) measuring less than 5 millimeters in diameter. Microbeads absorb persistent organic pollutants (POPs) and heavy metals present in the water. When marine animals consume these plastic particles, toxins enter the aquatic food chain, bioaccumulating across trophic levels.

Hence, option (a) is the correct answer.

22. Consider the following statements: [CSE-2019]

1. Agricultural soils release nitrogen oxides into the environment.

2. Cattle release ammonia into the environment.

3. Poultry industry releases reactive nitrogen compounds into the environment.

Which of the statements given above is/are correct?

(a) 1 and 3 only

(b) 2 and 3 only

(d) 1, 2 and 3

Ans. (d)

Exp:

Agricultural soils are a major source of nitrogen oxides (such as Nitrous Oxide, and Nitric Oxide, NO). Synthetic nitrogenous fertilizers and organic manures added to soils that release nitrogen oxides as volatile by-products. Hence, statement 1 is correct.

Cattle and other livestock are significant sources of ammonia (NH3). Nitrogen excreted in livestock urine and dung (primarily in the form of urea) rapidly hydrolyzes to form volatile ammonia gas. Hence, statement 2 is correct.

The poultry industry releases substantial quantities of reactive nitrogen compounds primarily ammonia (NH3) along with trace amounts of nitrous oxide (N2O). Hence, statement 3 is correct.

Hence, option (d) is the correct answer.

23. In India, the use of carbofuran, methyl parathion, phorate and triazophos is viewed with apprehension. These chemicals are used as: [CSE-2019]

(a) Pesticides in agriculture

(b) Preservatives in processed foods

(d) Moisturizing agents in cosmetics

Ans. (a)

Exp:

Carbofuran, methyl parathion, phorate, and triazophos are organophosphate and carbamate chemicals used as pesticides in agriculture. They are viewed with serious apprehension due to their high toxicity, adverse health impacts on humans and wildlife, and environmental persistence

Hence, option (a) is the correct answer.

24. Which of the following is/are the possible consequence/s of heavy sand mining in river beds? [CSE-2018]

1. Decreased salinity in the river

2. Pollution of groundwater

3. Lowering of the water- table.

Select the correct answer using the code given below:

(a) 1 only

(b) 2 and 3 only

(d) 1, 2 and 3

Ans. (b)

Exp:

Excessive sand removal deepens the riverbed and erodes estuary buffers. Near coastal regions, this deepening allows saline seawater to intrude inland into the river channel, which actually increases river and estuary salinity rather than decreasing it. Hence, statement 1 is not correct.

The sand bed acts as a natural biological filter for the underlying aquifers. Removing this natural filtration layer exposes groundwater directly to surface pollutants, agricultural runoff, and heavy metals. Hence, statement 2 is correct.

Sand has a high water-retention capacity and serves as an underground sponge. Excessive extraction alters the riverbed gradient, accelerates streamflow velocity, and reduces the time water stays in contact with the bed to recharge aquifers. Hence, statement 3 is correct.

Hence, option (b) is the correct answer.

25. Due to improper/indiscriminate disposal of old and used computers or their parts, which of the following are released into the environment as e-waste? [CSE-2013]

1. Beryllium

2. Cadmium

3. Chromium

4. Heptachlor

5. Mercury

6. Lead

7. Plutonium.

Select the correct answer using the codes given below:

(a) 1, 3, 4, 6 and 7 only

(b) 1, 2, 3, 5 and 6 only

(d) 1, 2, 3, 4, 5, 6 and 7

Ans. (b)

Exp:

Beryllium, cadmium, chromium, mercury and lead can be associated with electronic waste. Heptachlor is an organochlorine pesticide, while plutonium is not a constituent of ordinary electronic waste. Hence, statement 4 and statement 7 are incorrect.

Therefore (b) 1, 2, 3, 5 and 6 only.

Hence, option (b) is the correct answer.

26. With reference to perfluoroalkyl and polyfluoroalkyl substances (PFAS) that are used in making many consumer products, consider the following statements:

1. PFAS are found to be widespread in drinking water, food and food packaging materials.

2. PFAS are not easily degraded in the environment.

3. Persistent exposure to PFAS can lead to bioaccumulation in animal bodies.

Which of the statements given above are correct? [CSE - 2024]

(a) 1 and 2 only

(b) 2 and 3 only

(d) 1, 2 and 3

Ans. (d)

Exp:

PFAS are a large group of synthetic chemicals used in products requiring resistance to water, oil, grease and heat. They have been detected in drinking water, food and food-packaging materials. Hence, statement 1 is correct.

PFAS are often called “forever chemicals” because many of them are highly persistent and resistant to environmental degradation, largely due to the strong carbon–fluorine (C–F) bonds. Hence, statement 2 is correct.

Some PFAS can bioaccumulate in humans and animals following prolonged exposure and may persist in their bodies. Hence, statement 3 is correct.

Hence, option (d) is the correct answer.

27. Consider the following: [CSE-2023]

1. Aerosols

2. Foam agents

3. Fire retardants

4. Lubricants

In the making of how many of the above are hydrofluorocarbons used?

(a) Only one

(b) Only two

(d) All four

Ans. (c)

Exp: HFCs are synthetic fluorinated gases developed mainly as alternatives to ozone-depleting substances such as CFCs and HCFCs. They have been widely used as refrigerants, propellants, and blowing agents.

HFCs can be used as propellants in aerosol products, as blowing/foaming agents to manufacture insulation foams, and as fire retardant chemicals.

However, they are not used as lubricants. While certain HFCs are used alongside specialized lubricants—particularly in refrigeration and industrial applications—they themselves are not used in the manufacturing of lubricants.

Hence, option (c) is the correct answer.

28. With reference to polyethylene terephthalate, the use of which is so widespread in our daily lives, consider the following statements: [CSE-2022]

1. Its fibres can be blended with wool and cotton fibres to reinforce their properties.

2. Containers made of it can be used to store any alcoholic beverage.

3. Bottles made of it can be recycled into other products.

4. Articles made of it can be easily disposed of by incineration without causing greenhouse gas emissions.

Which of the statements given above are correct?

(a) 1 and 3 only

(b) 2 and 4 only

(d) 2 and 3 only

Ans. (a)

Exp: PET is a thermoplastic polymer widely used to make plastic bottles, food containers, polyester fibres, packaging films, etc.

PET is used to make polyester fibres. These fibres can be blended with natural fibres such as cotton and wool. This blending makes natural fiber stronger, more durable and wrinkle-resistant fabric. Hence, statement 1 is correct.

PET containers can be used for some alcoholic beverages, but not any alcoholic beverage. Hence, statement 2 is not correct.

PET is one of the most widely recycled plastics. Used PET bottles can be processed and converted into products such as Polyester fibres, clothing/textiles, carpets, packaging materials and new PET products.Hence, statement 3 is correct.

PET contains carbon and hydrogen, so when it is incinerated, produces significant volumes of carbon dioxide (CO2), a potent greenhouse gas. Hence, statement 4 is not correct.

Hence, option (a) is the correct answer.

29. Consider the following statements: [CSE-2022]

1. Other than those made by humans, nanoparticles do not exist in nature.

2. Nanoparticles of some metallic oxides are used in the manufacture of some cosmetics.

3. Nanoparticles of some commercial products which enter the environment are unsafe for humans.

Which of the statements given above is/are correct?

(a) 1 only

(b) 3 only

(d) 2 and 3 only

Ans. (d)

Exp: Nanoparticles are produced by Volcanic activity, forest fires, erosion, weathering and biological processes. Therefore, they exist naturally and are not exclusively man-made. Hence, statement 1 is not correct.

Nanoparticles of metallic oxides, most notably titanium dioxide (TiO2) and zinc oxide (ZnO), because of their special optical and protective properties, are widely used in commercial cosmetics, particularly in sunscreens. Hence, statement 2 is correct.

Some nanoparticles released from commercial products can easily penetrate biological membranes, cross cellular barriers, and accumulate in vital organs, posing health risks to humans and aquatic ecosystems. Hence, statement 3 is correct.

Hence, option (d) is the correct answer.

30. Steel slag can be the material for which of the following? [CSE-2020]

1. Construction of base road

2. Improvement of agricultural soil

3. Production of cement.

Select the correct answer using the code given below:

(a) 1 and 2 only

(b) 2 and 3 only

(d) 1, 2 and 3

Ans. (d)

Exp: Steel slag is a byproduct generated during the manufacturing of steel. Because it is hard, durable, and possesses excellent strength and load-bearing properties, it is widely used in the construction of pavements and road bases.

Owing to its high mineral content of calcium, magnesium, and silicon, it is also utilized to improve agricultural soil by raising the pH of acidic soils and supplying essential plant nutrients. Furthermore, steel slag can serve as a supplementary cementitious material in cement and concrete applications.

Hence, option (d) is the correct answer.