Pollution: UPSC Previous Year Questions (Environment and Ecology)
5 previous year UPSC Prelims questions on Pollution (Environment and Ecology). Choose an option to see the answer and explanation.
Explanations state facts as of the year each question was asked; words like “recently” refer to that year.
Showing 1–5 of 5 questions
UPSC 2021Environment and Ecology · Pollution
Q1. Why is there a concern about copper smelting plants? 1. They may release lethal quantities of carbon monoxide into the environment. 2. The copper slag can cause the leaching of some heavy metals into the environment. 3. They may release sulphur dioxide as a pollutant. Select the correct answer using the code given below.
Explanation
Copper Smelting is a process of applying heat to ore in order to extract a base metal. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal base behind. It is the method of extracting pure elemental copper (Cu) from copper concentrate (CuFeS₂).
Statement 1 is incorrect: Copper smelting generally does not release lethal quantities of carbon monoxide (CO) into the environment.
Statement 2 and 3 are correct: Some smelting processes can also produce large quantities of solid waste, known as slag. This slag may leach heavy metals (arsenic, cadmium, lead or mercury depending on the composition of the ore) into groundwater reservoirs. Smelting processes are known to emit high quantities of air pollutants such as hydrogen fluoride, sulphur dioxide, oxides of nitrogen, offensive and noxious smoke fumes, vapours, gases, and other toxins.
Exam tip:
For S1, ’’Lethal quantities" is an extreme phrase, what is lethal quantity? How to define it? It’s all vague and hence more probable to be false, giving correct option B
UPSC 2021Environment and Ecology · Pollution
Q2. With reference to furnace oil, consider the following statements: 1. It is a product of oil refineries. 2. Some industries use it to generate power. 3. Its use causes sulphur emissions into the environment. Which of the statements given above are correct?
Explanation
Statement 1 is correct: Furnace oil or fuel oil is a dark viscous residual product of crude-oil distillation. It is used as a fuel in different types of combustion equipment.
Statement 2 is correct: Marine engines and slow speed engines use Furnace oil for power generation, they are used for drying tea leaves. Thermic fluid heaters and hot air generators also use Furnace oil.
Statement 3 is correct: The emissions of oxides of sulphur are a direct result of the sulphur content of the fuel oil.
Additional insight:
Furnace oil is a dark, viscous residual fuel obtained by blending mainly heavier components from crude distillation units. Compared to other petroleum products, it has a relatively low flash point and high viscosity. Its major advantages are:
High energy content, making it an efficient fuel choice for heating purposes Often cost-competitive compared to other heating options Readily available in many regions, ensuring a consistent supply Furnace/fuel oil combustion can produce emissions, including sulfur dioxide (SO₂), nitrogen oxides (NOx), and particulate matter
UPSC 2021Environment and Ecology · Pollution
Q3. Magnetite particles, suspected to cause neurodegenerative problems, are generated as environmental pollutants from which of the following? 1. Brakes of motor vehicles 2. Engines of motor vehicles 3. Microwave stoves within homes 4. Power plants 5. Telephone lines Select the correct answer using the code given below.
Explanation
Magnetite particles are a highly magnetic mineral form of iron and are known to be present in air pollution. Exposure to airborne particulate matter (PM) is associated with pulmonary, cardiovascular and neurological problems.
Option 1 is correct: Vehicle brake systems are the major source of airborne magnetite at the roadside.
Option 2 is correct: Petrol and diesel-engine exhaust are also a source of airborne magnetite.
Option 4 is correct: Other sources of Magnetite pollution include Power plants. Options 3 and 5 are incorrect: Household microwave stoves and telephone lines not are established as sources of airborne magnetite particles. Other sources of Magnetite pollution include microwave Stoves within homes, As per WHO, Telephone lines produce low frequency, low energy electromagnetic fields which are the potential source of magnetite particles.
Exam tip:
For S5, Had telephone lines been a real source of neurodegenerative magnetite particles, the effects would have surfaced in public health long ago -- given our lifelong proximity. Since no such pattern is observed, the claim lacks merit. Hence likely false. Giving option B as correct.
UPSC 2021Environment and Ecology · Pollution
Q4. The ‘Common Carbon Metric’, supported by UNEP, has been developed for
Explanation
The Common Carbon Metric’ is a protocol developed by United Nations Environment Program’s Sustainable Buildings & Climate Initiative (UNEP-SBCI) for measuring energy use & reporting GHG emissions from Building Operations. Its purpose is to support greenhouse gas (GHG) emission’s reductions through accurate measurement of energy efficiency improvements in building operations.
UPSC 2021Environment and Ecology · Pollution
Q5. What is blue carbon?
Explanation
Blue Carbon is the carbon captured by the world’s ocean and coastal ecosystems. There are three types of coastal ecosystems -- mangroves, seagrasses and tidal marshes; these store half the "blue" carbon buried beneath the ocean floor. These areas absorb and store carbon at a much faster rate than other areas, such as forests, and can continue to do so for millions of years. The carbon found in coastal soil is often thousands of years old.
Answer key for these questions
Q
UPSC year
Correct answer
1
2021
(b) 2 and 3 only
2
2021
(d) 1, 2 and 3
3
2021
(b) 1, 2 and 4 only
4
2021
(a) Assessing the carbon footprint of building operations around the world
5
2021
(a) Carbon captured by oceans and coastal ecosystems
Frequently asked questions
How many previous year UPSC questions are there on Pollution?
This page covers 5 previous year UPSC Prelims GS Paper-I questions on Pollution (Environment and Ecology), asked from 2005 to 2025. Each has the correct answer and an explanation.
How should I use previous year UPSC questions for Prelims?
Attempt each question first, then open the answer and read the explanation for every option. Repeat by chapter, and track which statements UPSC reuses across years. Previous year questions show the exam pattern and difficulty level.
Which years are covered for Pollution?
Questions on Pollution (Environment and Ecology) are available for 14 years, from 2005 to 2025. Use the Year filter to practise a single paper.
