Set 5 | Important Environment Pollution MCQs

Correct Answer is B.

Statement 1 is incorrect: Dissolving carbon dioxide in seawater forms carbonic acid, which lowers the ocean’s pH, a process known as ocean acidification. This increases hydrogen ion (H+) concentration in the ocean.

Statement 2 is correct: Various factors can locally influence CO2’s chemical reactions with seawater, contributing to ocean acidification. For example:

• Acid rain: With a pH between 2 and 5.6, acid rain impacts surface ocean chemistry, significantly affecting ocean acidification locally and regionally, though minimally on a global scale.
• Eutrophication: Large plankton blooms, followed by bacterial respiration during decomposition, decrease oxygen and increase CO2 in seawater, lowering pH.

Statement 3 is correct: Ocean acidification affects marine ecosystems by:

• Reducing carbonate levels, essential for building blocks in seawater.
• Disrupting marine life, particularly species that struggle to form calcium carbonate shells in acidified waters.
• Impacting commercial fisheries, shellfisheries, aquaculture, recreational fisheries, traditional practices, and tourism activities like snorkeling and scuba diving.

Correct Answer is C.

• Statement 1 is correct: Nitrogen makes up about 78% of the Earth’s atmosphere. In its gaseous form, nitrogen is colorless, odorless, and generally inert. However, when released from sources like agriculture, sewage, and biological waste, it becomes reactive and can act as a pollutant and potent greenhouse gas.
• Statement 2 is incorrect: Nitrous oxide (N₂O) is 300 times more potent than carbon dioxide in warming the atmosphere and also depletes the ozone layer. Due to its shorter lifespan, reducing N₂O emissions could have a quicker impact on global warming. Atmospheric N₂O levels reached 331 parts per billion in 2018, a 22% increase since pre-industrial times.
• Agriculture is responsible for nearly 70% of global N₂O emissions, driven by nitrogen use in synthetic fertilizers and manure. Other sources include the chemical industry, wastewater, and fossil fuel burning.
• Statement 3 is correct: Nitrogen pollution affects air and water quality, harming humans, animals, and plants. Ammonia (NH₃) and nitrogen dioxide (NO₂) worsen air quality and can exacerbate respiratory and heart conditions, leading to millions of premature deaths globally.
• N₂O is also a greenhouse gas that depletes the ozone layer. Nitrate pollution from fertilizers and manure contaminates rivers and seas, posing health risks to humans, fish, coral, and plant life.

Correct Answer is D.

Eutrophication is the enrichment of water by nutrient salts, leading to ecosystem changes. Human activities contribute 80% of nitrogen and 75% of phosphorus in lakes and streams. Phosphorus-rich sources that contribute to eutrophication include:

• Fertilizers
• Untreated sewage
• Phosphorus-containing detergents
• Industrial waste discharge

Agriculture and industrial waste are the main contributors to eutrophication. The release of carbon dioxide into the air does not contribute to this process.

Correct Answer is B.

• Statement 1 is incorrect: Persistent Organic Pollutants (POPs) are chemicals that persist in the environment, accumulate in living organisms, and harm human health and the environment. The Stockholm Convention is a global treaty aimed at protecting human health and the environment from these pollutants.
• In line with this, the Ministry of Environment, Forest, and Climate Change (MoEFCC) announced the “Regulation of Persistent Organic Pollutants Rules” on March 5, 2018, under the Environment (Protection) Act, 1986.
• Statement 2 is correct: For POPs already regulated domestically, the Cabinet delegated ratification powers under the Stockholm Convention to the Union Ministers of External Affairs (MEA) and Environment, Forest, and Climate Change (MoEFCC), streamlining the process.
• Statement 3 is correct: The Cabinet’s approval of POPs ratification underscores India’s commitment to international obligations for environmental and human health protection.
• This ratification also enables India to access Global Environment Facility (GEF) financial resources for updating its National Implementation Plan (NIP).

Correct Answer is D.

Statements 1 and 2 are correct: Pollutants are classified into four types:

1. Primary pollutants are directly emitted from sources and remain in their original form, e.g., DDT and plastic.
2. Secondary pollutants are not directly emitted but form through interactions between primary pollutants, e.g., peroxyacetyl nitrate (PAN) forms from nitrogen oxides and hydrocarbons.
3. Quantitative pollutants occur naturally, but their concentrations exceed safe levels, e.g., nitrogen oxides and carbon dioxide (CO2) when present in excessive amounts.
4. Qualitative pollutants are substances not naturally found in the environment, introduced by humans, e.g., insecticides, herbicides, fungicides, and pesticides.

Statement 3 is correct: The 2019 “Pollution and Health Metrics: Global, Regional and Country Analysis” report by the Global Alliance on Health and Pollution (GAHP) updates findings from The Lancet Commission on Pollution and Health, providing a global ranking of pollution-related deaths.

Correct Answer is D.

Option D is correct: According to estimates from the Center for Science and Environment (CSE), coal-based thermal power plants account for 70% of the total freshwater withdrawal by all industries.

The new regulations from the environment ministry permit thermal power plants to use coal with high ash content and also include the following provisions:

• Thermal power plants are responsible for the proper disposal of coal ash and must meet emission standards.
• Emphasizes the use of pollution control technologies.
• Mandates that coal must be transported in covered vehicles.

Correct Answer is D.

Explanation: All the effects mentioned are correct. Additional characteristics of ammonia (NH3) include:

• Colorless, highly reactive, and soluble alkaline gas.
• Stored as a liquid under high pressure or in gaseous form at low temperatures.
• Naturally present in the body and secreted by the kidneys to neutralize excess acid.
• Ammonia, in the form of nitrogen, is beneficial for plants.
• The largest source of ammonia is agriculture, including animal husbandry.

Other uses of ammonia include its role in industrial chemical production, such as fertilizers, plastics, synthetic fibers, and dyes.

Correct Answer is D.

Both statements are interchanged.

• Statement 1 is incorrect: Nonpoint sources involve the discharge of pollutants from diffuse sources over a larger area, such as runoff from agricultural fields, grazing lands, construction sites, roads, and streets.
• Statement 2 is incorrect: Point sources refer to pollutants discharged from a specific location, like a drainpipe carrying industrial effluents directly into a water body.

Correct Answer is D.

The statements you’ve provided cover different aspects of environmental management and water purification:

1. Riparian Buffers: This statement is accurate. Riparian buffers are vegetated areas near streams that help shield the stream from the impacts of adjacent land use, thereby improving water quality. They play a crucial role in maintaining the ecological health of streams and rivers.
2. Water Hyacinth: This statement is also correct. Water hyacinth is known for its invasive nature and its rapid growth in aquatic environments. It is referred to as the “terror of Bengal” due to its negative impacts on water bodies. However, it is noteworthy that water hyacinth can be used for wastewater purification and nutrient removal due to its ability to absorb toxins and heavy metals.
3. Oil Zappers: This statement is correct as well. Oil zappers are materials or technologies used to clean oil spills in water, helping to mitigate environmental damage caused by such spills.
4. Eucalyptus Trees: This statement is accurate but requires a bit of nuance. Eucalyptus trees are known for their high water usage, which can lead to groundwater depletion. However, they do absorb excess wastewater and release water vapor into the atmosphere, which can be beneficial in certain contexts.

Overall, each statement provides useful information about environmental management and the effects of different species and technologies on water and land resources.

Correct Answer is A.

Bioremediation is the process of detoxifying pollutants from the environment using microorganisms, plants, or their enzymes.

Correct Statements:

1. In-Situ Treatment:
   • In-Situ: Involves treating contaminated material at its original site without removal. This is correct.
   • Bioventing: Involves supplying air and nutrients through wells to stimulate the growth of indigenous bacteria in contaminated soil. This is accurate.
   • Biosparging: Involves injecting air under pressure below the water table to increase groundwater oxygen concentrations and enhance the biological degradation of contaminants by naturally occurring bacteria. This is also accurate.
   • Bioaugmentation: Involves importing microorganisms to a contaminated site to enhance the degradation process. This is correct.
2. Incorrect Statements:
   • Ex-Situ Treatment:
     • Ex-Situ: Involves removing contaminated material to treat it elsewhere. This is correct.
     • Land Farming: An ex-situ treatment process where contaminated soils, sediments, or sludges are mixed into the soil surface at the treatment site and periodically turned over to aerate the mixture. This is correctly identified as an ex-situ method.
     • Bio-Piles: Involves mixing excavated soils with amendments, forming compost piles, and enclosing them for treatment. This is a valid ex-situ method.
     • Bioreactors: Involves processing contaminated material through an engineered containment system. This is a correct description of an ex-situ method.
     • Composting: The process of biological degradation of organic materials under controlled conditions to produce a stable material usable as fertilizer. This is correctly identified.

Correct Answer is B.

Mycoremediation is a bioremediation method that uses fungi to decontaminate environments. Fungi are effective at breaking down a wide range of contaminants, including organic pollutants, heavy metals, and some radioactive materials. They do this through their natural processes, such as decomposing organic matter and absorbing contaminants.

Fungi are advantageous for several reasons:

• Cost-Effective: Fungi can be relatively inexpensive to use compared to other remediation methods.
• Effective: They can break down complex pollutants and often work in various environmental conditions.
• Environmentally Friendly: Fungi are natural decomposers and integrate well into ecosystems, making them a sustainable option for cleaning contaminated sites.

Mycoremediation is a promising technique for managing environmental pollution and improving water quality.