Set 10 | Important Environment Pollution MCQs

Correct Answer is A.

• Argimon seed (also known as Argemone mexicana or prickly poppy seeds) is commonly used as an adulterant in mustard seeds. These seeds resemble mustard seeds in appearance but are highly toxic. Consumption of argimon seeds can lead to a condition called epidemic dropsy, which causes swelling, glaucoma, and other severe health issues.
• The other options, such as papaya seeds, cumin seeds, and coriander seeds, are not typically used as adulterants in mustard seeds.

Correct Answer is A.

Microbeads are tiny plastic particles, often less than 1 millimeter in size, commonly used in personal care products like exfoliating scrubs and toothpaste. When these products are washed off, microbeads enter water systems and eventually reach oceans and other water bodies. They are highly persistent in the environment and do not biodegrade easily.

Microbeads are considered harmful to marine ecosystems because:

1. Marine organisms, such as fish and plankton, often mistake them for food, leading to ingestion and accumulation in the food chain.
2. They can cause physical harm, block digestive systems, and release toxic chemicals, affecting marine life and biodiversity.
3. Their presence in water bodies contributes to plastic pollution, which is a growing global environmental concern.

The other options (B, C, and D) are not directly related to the primary concerns about microbeads.

Correct Answer is B.

Rain is known for its role in cleaning the environment, particularly the atmosphere. It helps remove dust, particulate matter, and some pollutants from the air through a process called scavenging. This natural cleansing process is why the air often feels fresher after rainfall. However, it is important to note that rain can also contribute to acid rain if it combines with pollutants like sulphur dioxide and nitrogen oxides, which can harm ecosystems.

• [A] Oxygen is essential for life and supports combustion but does not directly clean the environment.
• [C] Nitrogen is a major component of the atmosphere but does not play a direct role in cleaning pollution.
• [D] Air itself is not a cleaning agent, though it carries pollutants and can disperse them.

Thus, rain is the most relevant option for cleaning a polluted environment.

Correct Answer is D.

• Harmful algal blooms, which are deadly for both humans and marine ecosystems, are becoming increasingly intense in Indian waters.
• These blooms are often triggered by natural processes such as upwelling, the formation of mud banks, and the discharge of nutrients from estuaries and land runoff during the south-west and north-east monsoons.
• These factors contribute to the growth of algae in coastal waters, leading to harmful blooms. Therefore, (d) is the correct answer.

Correct Answer is D.

Some scientists suggest the use of cirrus cloud thinning and the injection of sulphate aerosol into the stratosphere as geoengineering techniques to mitigate global warming. These methods aim to reflect a portion of sunlight back into space, thereby reducing the amount of heat trapped in the Earth’s atmosphere.

• Cirrus cloud thinning involves reducing the density of high-altitude cirrus clouds, which trap heat, allowing more heat to escape into space.
• Sulphate aerosol injection mimics the cooling effect of volcanic eruptions by releasing reflective particles into the stratosphere to scatter sunlight.

These techniques are part of solar radiation management (SRM), a proposed strategy to combat global warming. The other options (a, b, and c) are not related to these methods.

Correct Answer is D.

The terms pyrolysis and plasma gasification are associated with waste-to-energy technologies. These processes are used to convert waste materials into energy or useful byproducts:

1. Pyrolysis: A thermal decomposition process that breaks down organic materials at high temperatures in the absence of oxygen, producing bio-oil, syngas, and char.
2. Plasma Gasification: A process that uses plasma (ionized gas) at extremely high temperatures to break down waste into syngas and inert slag, which can be used for energy generation.

These methods are part of advanced waste management strategies aimed at reducing landfill use and generating energy from waste. The other options (A, B, and C) are unrelated to these processes.

Correct Answer is C.

• Cold air, being denser and heavier than warm air, does not rise high into the atmosphere. As a result, dust particles, pollutants, and environmental debris accumulate near the surface, forming a layer in the lower atmosphere.
• This phenomenon explains why pollution levels in Delhi increase significantly during winter. Therefore, Assertion (A) is correct.
• However, Reason (R) is incorrect because the combustion process in motor vehicles does not decrease during winter; in fact, it remains relatively constant or may even increase due to colder weather conditions.

Correct Answer is D.

The most important indoor air pollutant is radon gas. Radon is a naturally occurring radioactive gas that can seep into buildings through cracks in the foundation, walls, or floors. It is colorless, odorless, and tasteless, making it difficult to detect without specialized equipment. Prolonged exposure to high levels of radon is a significant health risk, as it is the second leading cause of lung cancer after smoking.

• [A] Sulphur Dioxide and [C] Nitrogen Dioxide are primarily outdoor pollutants associated with industrial emissions and vehicle exhaust.
• [B] Carbon Dioxide is a common indoor pollutant but is less harmful compared to radon at typical indoor levels.

Thus, radon gas is the most critical indoor air pollutant due to its severe health implications.

Correct Answer is C.

Cigarette smoke is a complex and highly toxic mixture of numerous chemicals, many of which are harmful to human health. Some of the key components include:

1. Carbon Monoxide: A poisonous gas that interferes with the blood’s ability to carry oxygen, leading to reduced oxygen supply to vital organs and tissues. This can contribute to cardiovascular diseases and other health issues.
2. Hydrogen Cyanide: A highly toxic chemical that can damage the respiratory system and interfere with the body’s ability to use oxygen.
3. Arsenic: A well-known poison that can cause cancer, skin lesions, and other serious health problems with long-term exposure.
4. Formaldehyde: A carcinogenic chemical used in embalming fluids. It can cause respiratory issues and is linked to cancer.
5. Benzene: A volatile organic compound (VOC) that is a known carcinogen and can cause leukemia and other blood disorders.
6. Nicotine: While present in small quantities, nicotine is the addictive substance in cigarettes. It stimulates the nervous system, leading to addiction and making it difficult for smokers to quit. Nicotine also has harmful effects on the cardiovascular system.

In addition to these, cigarette smoke contains thousands of other chemicals, including tar, ammonia, lead, and cadmium, all of which contribute to its toxicity. The combination of these substances makes cigarette smoke a major cause of preventable diseases, including lung cancer, heart disease, and chronic obstructive pulmonary disease (COPD).

Correct Answer is B.

• Lead is a widespread environmental pollutant. Children residing near facilities that process lead, such as lead smelters, often exhibit abnormally high levels of lead in their blood.
• Certain lead compounds are vibrant in color and are commonly used in paints, making lead-based paint a significant source of lead exposure for children.
• In addition to these, other sources of lead include contaminated soil, water, lead-containing products, and even bullets. Therefore, option (b) is the correct answer.