Set 8 | Important Environment Pollution MCQs

Correct Answer is D.

Sulphur dioxide (SO₂) is a harmful air pollutant gas that is released into the atmosphere primarily through the burning of fossil fuels such as coal and oil. It is a byproduct of industrial processes, power plants, and vehicle emissions. Sulphur dioxide is a major contributor to acid rain and can cause respiratory problems in humans, damage to vegetation, and harm to ecosystems.

• [A] Hydrogen: Hydrogen is not a pollutant and is not released in significant amounts by burning fossil fuels.
• [B] Nitrogen: Nitrogen (N₂) is an inert gas and makes up the majority of the Earth’s atmosphere. It is not a pollutant.
• [C] Oxygen: Oxygen (O₂) is essential for life and is not a pollutant.

Thus, the correct answer is [D] Sulphur dioxide, as it is a well-known air pollutant released by burning fossil fuels.

Correct Answer is C.

• [A] Smog: Smog is directly related to air pollution. It is a type of air pollution caused by the interaction of sunlight with pollutants like nitrogen oxides and volatile organic compounds (VOCs) in the atmosphere.
• [B] Acid Rain: Acid rain is caused by air pollutants such as sulphur dioxide (SO₂) and nitrogen oxides (NOₓ), which react with water vapour in the atmosphere to form acidic precipitation.
• [D] Asbestosis: Asbestosis is a lung disease caused by inhaling asbestos fibers, which are air pollutants released from construction materials and industrial processes.
• [C] Eutrophication: Eutrophication is not related to air pollution. It is a process that occurs in water bodies (e.g., lakes, rivers) due to the excessive accumulation of nutrients like nitrogen and phosphorus, often from agricultural runoff or sewage. This leads to algal blooms, oxygen depletion, and harm to aquatic ecosystems.

Thus, the correct answer is [C] Eutrophication, as it is related to water pollution, not air pollution.

Correct Answer is C.

Fly ash pollution is primarily caused by thermal power plants. Fly ash is a fine, powdery residue produced when coal is burned to generate electricity. It contains toxic substances like heavy metals (e.g., arsenic, mercury, and lead) and poses significant environmental and health risks if not properly managed. Fly ash can contaminate air, water, and soil, leading to respiratory problems, water pollution, and soil degradation.

• [A] Oil refining: Oil refining produces pollutants like sulphur dioxide and particulate matter, but not fly ash.
• [B] Fertilizer industry: The fertilizer industry releases pollutants like ammonia and nitrous oxides, but fly ash is not a byproduct of this industry.
• [D] Mining: Mining can produce dust and particulate matter, but fly ash is specifically associated with coal combustion in thermal power plants.

Thus, the correct answer is [C] Thermal power plant, as it is the primary source of fly ash pollution.

Correct Answer is C.

The Green Muffler is a concept related to reducing noise pollution. It involves planting rows of trees and shrubs along roadsides, industrial areas, and other noise-prone zones to act as natural sound barriers. The vegetation absorbs, deflects, and reduces noise levels, helping to mitigate the impact of noise pollution on the environment and human health.

• [A] Soil pollution: The Green Muffler is not related to soil pollution.
• [B] Air pollution: While trees can help reduce air pollution by absorbing pollutants, the Green Muffler specifically targets noise pollution.
• [D] Water pollution: The Green Muffler is not related to water pollution.

Thus, the correct answer is [C] Noise pollution, as the Green Muffler is a strategy to combat noise pollution using vegetation.

Correct Answer is C.

• The Bhopal Gas Tragedy, one of the world’s worst industrial disasters, occurred on December 3, 1984, in Bhopal, India. It involved the leakage of methyl isocyanate (MIC), a highly toxic gas, from the Union Carbide India Limited (UCIL) pesticide plant.
• The gas leak exposed over half a million people to toxic fumes, resulting in thousands of deaths and long-term health issues for survivors. The disaster highlighted the need for stricter industrial safety regulations and environmental protection measures.
• Thus, the correct answer is [C] December 3, 1984.

Correct Answer is C.

Polythene bags are made of polymers, specifically polyethylene, which are long-chain molecules composed of repeating units of ethylene. These polymers are highly durable and resistant to natural degradation processes, making polythene bags non-biodegradable. They do not break down easily in the environment and can persist for hundreds of years, contributing to environmental pollution.

• [A] Unbreakable molecules: This is not a scientific term and does not describe the nature of polythene.
• [B] Inorganic compounds: Polythene is an organic compound, not inorganic.
• [D] Proteins: Polythene is not made of proteins; it is a synthetic polymer derived from petroleum.

Thus, the correct answer is [C] Polymers, as polythene bags are made of synthetic polymers that are difficult to destroy.

Correct Answer is D.

• [A] Plastic: Most plastics, including polythene, are non-biodegradable and can persist in the environment for hundreds of years.
• [B] Polythene: Polythene is a type of plastic and is non-biodegradable.
• [C] Mercury: Mercury is a heavy metal and is not biodegradable. It is highly toxic and persists in the environment.
• [D] Rubber: Natural rubber is biodegradable because it is derived from organic sources (e.g., rubber trees) and can be broken down by microorganisms over time. However, synthetic rubber may not be biodegradable.

Thus, the correct answer is [D] Rubber, as natural rubber is biodegradable.

Correct Answer is D.

• [A] Cigarette bud: Cigarette butts can take 1 to 5 years to decompose, as they are made of cellulose acetate, a type of plastic.
• [B] Leather shoe: Leather shoes can take 25 to 40 years to decay, depending on the conditions.
• [C] Photo film: Photo film can take 20 to 30 years to decompose due to its chemical composition.
• [D] Plastic bag: Plastic bags are made of polyethylene and can take up to 500 years or more to decay. They are highly resistant to natural degradation processes.

Thus, the correct answer is [D] Plastic bag, as it takes the maximum time to decay among the options listed.

Correct Answer is A.

Lichens are widely recognized as bioindicators of air pollution, particularly for monitoring air quality. They are highly sensitive to pollutants such as sulphur dioxide (SO₂) and nitrogen oxides (NOₓ). When air pollution levels are high, lichens tend to disappear or show visible damage, making them excellent indicators of environmental health.

• [B] Fern: Ferns are not specifically used as bioindicators of air pollution.
• [C] Money plant: Money plants are not known for their sensitivity to air pollution and are not used as bioindicators.
• [D] Dodder: Dodder is a parasitic plant and is not related to air pollution monitoring.

Thus, the correct answer is [A] Lichen, as it is a well-known bioindicator of air pollution.

Correct Answer is A.

Biological Oxygen Demand (BOD) is a measure of the amount of oxygen required by microorganisms to decompose organic matter in water. It is a key indicator of pollution in aquatic environments, such as rivers, lakes, and oceans. High BOD levels indicate the presence of excessive organic pollutants (e.g., sewage, agricultural runoff), which can deplete oxygen levels in water, harming aquatic life.

• [B] Soil: BOD is not used to measure pollution in soil.
• [C] Air: BOD is unrelated to air pollution.
• [D] All the above: BOD is specific to water pollution and does not apply to soil or air.

Thus, the correct answer is [A] Aquatic environment, as BOD is a measure of pollution in water bodies.