Set 6 | Important Environment Pollution MCQs

Correct Answer is D.

• Pollution arises from unforeseen alterations in the physical, chemical, and biological properties of soil, water, and air, primarily due to the excessive buildup of pollutants.
• When pollution is caused by human activities, it is referred to as anthropogenic pollution. This type of pollution leads to the release of non-biodegradable pollutants, which either do not decompose naturally or break down at an extremely slow rate. As a result, managing non-biodegradable pollutants generated by anthropogenic pollution becomes a significant challenge.

Correct Answer is B.

The anthropogenic environment refers to the surroundings that have been altered or modified by human activities. This includes changes made to natural landscapes through urbanization, industrialization, deforestation, agriculture, and infrastructure development.

Unlike the natural environment, which remains untouched by human influence, the anthropogenic environment is shaped by human interventions, often leading to environmental issues like pollution, habitat destruction, and climate change.

• [A] Natural Environment – This consists of elements that exist without human interference, such as forests, rivers, mountains, and wildlife.
• [C] Urban Environment – This refers specifically to cities and towns, characterized by buildings, roads, and human settlements, which are a subset of the anthropogenic environment.
• [D] Modern Environment – This is not a standard environmental classification but may refer to contemporary human-influenced surroundings, including technological advancements.

Thus, the correct answer is [B] Anthropogenic environment because it directly refers to the environment modified by human activities.

Correct Answer is B.

• [B] Biodegradable pollutants are substances that can be broken down by natural decomposers like bacteria and fungi into harmless or less harmful substances over time. Sewage consists of organic waste, which can decompose naturally.
• [A] Mercury – A non-biodegradable heavy metal that persists in the environment and accumulates in living organisms, causing toxicity.
• [C] Plastic – Non-biodegradable; takes hundreds to thousands of years to break down, leading to long-term environmental pollution.
• [D] Asbestos – A non-biodegradable mineral fiber that remains in the environment for decades and poses serious health risks, including respiratory diseases.

Thus, sewage is the correct answer as it is a biodegradable pollutant.

Correct Answer is C.

The combustion of coal, petrol, and diesel releases harmful gases such as carbon dioxide (CO₂), carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen oxides (NOₓ), and particulate matter into the atmosphere. These pollutants contribute to air pollution, leading to problems like smog, acid rain, respiratory diseases, and global warming.

• [A] Water pollution – While combustion can contribute indirectly (e.g., acid rain contaminating water bodies), it is not the primary source of water pollution.
• [B] Land pollution – Solid waste from burning fossil fuels, like ash, can affect land, but the major impact is on air quality.
• [D] Noise pollution – Fossil fuel combustion itself does not cause noise pollution, though engines and machinery using these fuels may contribute to it.

Thus, the main environmental impact of burning coal, petrol, and diesel is air pollution.

Correct Answer is B.

Solar energy is a clean and renewable source of power that does not produce any atmospheric pollution during its operation. Solar panels convert sunlight into electricity without emitting harmful gases or pollutants, making it an environmentally friendly energy source.

• [A] Nuclear energy – While nuclear power plants do not emit greenhouse gases during electricity generation, they produce radioactive waste, which poses environmental and safety risks.
• [C] Petroleum energy – Burning petroleum releases carbon dioxide (CO₂), carbon monoxide (CO), sulfur dioxide (SO₂), and nitrogen oxides (NOₓ), contributing to air pollution and climate change.
• [D] Coal energy – Coal combustion is one of the largest sources of air pollution, emitting carbon dioxide, sulfur dioxide, particulate matter, and heavy metals like mercury, which are harmful to health and the environment.

Thus, solar energy is the only option that produces no atmospheric pollution, making it the correct answer.

Correct Answer is A.

A biodegradable pollutant is a substance that can be broken down naturally by microorganisms like bacteria and fungi. Sewage consists of organic waste, which decomposes over time, making it biodegradable.

• [B] Asbestos – A non-biodegradable mineral fiber that remains in the environment for decades and poses health risks.
• [C] Plastic – Non-biodegradable; takes hundreds to thousands of years to break down and contributes to long-term pollution.
• [D] Polythene – A type of plastic that is also non-biodegradable and causes severe environmental pollution.

Thus, sewage is the correct answer as it is a biodegradable pollutant.

Correct Answer is B.

• Photochemical smog is a blend of pollutants created when nitrogen oxides and volatile organic compounds react with sunlight, resulting in a brownish haze above urban areas.
• It is more prevalent during the summer months due to increased sunlight. This smog forms primarily from nitrogen oxides (NOx) and ozone (O3).
• The typical components of photochemical smog include ozone, nitric oxide, acrolein, formaldehyde, and peroxyacetyl nitrate (PAN).

Correct Answer is D.

• Smog is a severe form of air pollution. The term “smog” is a blend of the words smoke and fog, referring to smoky fog.
• It is a visible type of air pollution made up of nitrogen oxides, sulfur oxides, ozone, smoke, and other particulate matter. Human-made smog originates from sources such as coal combustion, vehicle emissions, industrial releases, forest and agricultural fires, and the photochemical reactions of these pollutants.

Correct Answer is D.

• Heavy Traffic: The noise level of traffic can vary depending on the volume and type of vehicles, typically ranging from 70 to 85 dB.
• Election Meetings: Can be quite loud due to large crowds and loudspeakers, with noise levels ranging from 80 to 100 dB.
• Rock Music: Concerts or music played at high volume can reach up to 120 dB or more.
• Jet Flight (at takeoff): Aircraft takeoff noise is one of the loudest, often exceeding 120 dB, especially close to the runway.

Correct Answer is C.

• Carbon monoxide is a colorless, odorless, and tasteless gas produced by the incomplete combustion of fossil fuels, such as in motor vehicles, cigarette smoke, and other combustion processes.
• When inhaled, carbon monoxide binds with hemoglobin in the blood more readily than oxygen, reducing the amount of oxygen transported to vital organs and tissues.
• This can lead to symptoms such as headaches, dizziness, confusion, shortness of breath, and, at high concentrations, unconsciousness and death.
• Prolonged exposure to even low levels of carbon monoxide can cause long-term health issues, especially for vulnerable individuals such as children, the elderly, and those with pre-existing heart or respiratory conditions.