Environmental pollution MCQ Quiz - Objective Question with Answer for Environmental pollution - Download Free PDF

The Correct answer is lungs.

Key Points

• Particulate matter (PM) refers to tiny solid or liquid particles suspended in the air, often resulting from activities such as combustion, industrial processes, or natural events like wildfires and volcanic eruptions.
• The lungs are the primary organs exposed to airborne pollutants due to their role in respiration.
• When inhaled, fine particulate matter (PM2.5 and PM10) can penetrate deep into the respiratory tract, reaching the alveoli where gas exchange occurs.
• This exposure can lead to a variety of health issues, including inflammation, reduced lung function, chronic respiratory diseases (e.g., asthma, bronchitis), and lung cancer.
• Long-term exposure to particulate matter has been linked to an increased risk of cardiopulmonary mortality and a rise in hospital admissions for respiratory illnesses.
• The World Health Organization (WHO) and other research institutions have emphasized the critical impact of particulate matter on respiratory health.
• Individuals living in areas with high levels of air pollution are at a higher risk, particularly children, the elderly, and individuals with preexisting respiratory conditions.

 Additional Information

• Intestines
  • The intestines are part of the digestive system and are not directly impacted by particulate matter in the air.
  • Although some toxins may enter the bloodstream via inhalation and indirectly affect other organs, the intestines are not the primary site of particulate matter impact.
• Kidneys
  • The kidneys filter waste and excess substances from the blood, but they are not directly affected by particulate matter inhalation.
  • However, long-term exposure to air pollution may contribute to systemic issues that could indirectly affect kidney health, such as hypertension.
• Liver
  • The liver is responsible for detoxifying harmful substances in the body, but it is not the primary target of particulate matter inhalation.
  • Some studies suggest that systemic inflammation from air pollution could impact liver function over time, but this is secondary to the effects on the lungs.

The correct answer is nitrous oxide.

Key Points

• Nitrous oxide (N₂O) is a greenhouse gas that contributes the least to global warming compared to other major greenhouse gases like carbon dioxide (CO₂), methane (CH₄), and chlorofluorocarbons (CFCs).
• Nitrous oxide accounts for a smaller portion of total greenhouse gas emissions globally, with its contribution being around 6% of all greenhouse gases.
• Despite its relatively low concentration, nitrous oxide has a Global Warming Potential (GWP) of approximately 298 times higher than CO₂ over a 100-year period, but its overall effect is less due to its lower abundance.
• Nitrous oxide is primarily emitted from agricultural activities such as the use of synthetic fertilizers, as well as other sources like the burning of fossil fuels and certain industrial processes.
• It has a relatively long atmospheric lifetime of about 114 years, but its total emissions are much less than those of carbon dioxide and methane.
• Efforts to reduce nitrous oxide emissions include optimizing fertilizer use in agriculture and improving industrial processes to minimize emissions.

 Additional Information

• Carbon dioxide (CO₂)
  • Carbon dioxide is the most abundant greenhouse gas responsible for global warming, contributing around 76% of total greenhouse gas emissions.
  • It is emitted primarily through the burning of fossil fuels (coal, oil, and gas), deforestation, and industrial processes.
  • It has a relatively low Global Warming Potential (GWP) of 1, but its sheer abundance makes it the largest contributor to global warming.
• Methane (CH₄)
  • Methane is a highly potent greenhouse gas with a Global Warming Potential (GWP) of around 25 times that of CO₂ over a 100-year period.
  • It is produced from sources such as livestock digestion (enteric fermentation), rice paddies, and the decomposition of organic matter in landfills.
  • Methane has a much shorter atmospheric lifetime of about 12 years but is a major contributor to global warming due to its high GWP.
• Chlorofluorocarbons (CFCs)
  • CFCs are synthetic compounds used primarily in refrigeration, air conditioning, and aerosol propellants.
  • They are potent greenhouse gases with a Global Warming Potential (GWP) in the thousands, but their emissions have been largely phased out under the Montreal Protocol due to their role in ozone layer depletion.
  • Although their emissions are now limited, their long atmospheric lifetimes allow them to persist and contribute to warming for decades.

The correct answer is Pesticide.

Key Points

• Biodegradable pollutants are substances or materials that can be broken down and decomposed by natural processes, such as bacteria or other living organisms, into simpler and non-harmful compounds.
• These pollutants include organic materials like food waste, paper, and natural fibers.
• Non-biodegradable pollutants, on the other hand, are substances or materials that do not break down easily or naturally in the environment over a short period of time.
• They persist in the environment and can cause long-term harm. Examples of non-biodegradable pollutants include plastics, certain chemicals, heavy metals, and synthetic materials.
• Faecal matter - Biodegradable organic waste from the digestive system of animals and humans that can be broken down by bacteria and other microorganisms.
• Urine - Biodegradable liquid waste produced by the kidneys that contains dissolved waste products and can decompose naturally.
• Domestic waste - Biodegradable waste generated from households, such as food scraps, paper, and plant material, which can be decomposed by biological processes.
• Pesticide - Non-biodegradable chemical substances used to control pests and insects that persist in the environment and can accumulate in the food chain, causing ecological and health concerns.

The correct answer is option 3.

Key Points

The correct relative contributions of greenhouse gases to global warming (approximate values based on IPCC reports) are:

• Greenhouse Gas Contribution to Global Warming
• CO₂ (Carbon Dioxide) ~ 64% – Major contributor
• CH₄ (Methane) ~ 17–20%
• CFCs and HFCs (Chlorofluorocarbons) ~ 12–14%
• N₂O (Nitrous Oxide) ~ 6% 

Key Points

• Ozone, formaldehyde, and PAN (Peroxyacetyl nitrate) are the primary components of photochemical smog.
• Photochemical smog is a secondary pollutant formed through the interaction of sunlight with nitrogen oxides (NOx) and volatile organic compounds (VOCs).
• Ozone is a reactive oxidizing agent that contributes to respiratory issues and damages vegetation.
• Formaldehyde and PAN are toxic to humans, plants, and animals and are significant contributors to air pollution.

Additional Information

• Ozone and SO₂: Ozone is a component of photochemical smog, but SO₂ is not. SO₂ primarily contributes to acid rain, not photochemical smog.
• NO₂ and SO₂: While NO₂ is a precursor to ozone formation in photochemical smog, SO₂ does not play a role in its formation. Instead, SO₂ is linked to industrial emissions and acid rain.
• Formaldehyde and PAN: These are components of photochemical smog, but the answer is incomplete without ozone, which is a crucial component.
• Photochemical Smog: It is also known as “Los Angeles Smog” and is characterized by the presence of oxidants like ozone, formaldehyde, and PAN. It forms in regions with high sunlight and significant vehicular emissions.
• SO₂: Sulfur dioxide is a gas resulting from the combustion of fossil fuels containing sulfur. It primarily contributes to acid rain and particulate pollution, not photochemical smog.

Option 2 is correct, i.e. Smog.

• Smog is an air pollutant that is composed mainly of particulate matter such as pollen and dust along with other particulate matter such as Sulphur oxides, Volatile organic compounds, nitrogen oxides, and ammonia gas.
• Smog happens due to smoke, dust, and practices of carbon entering into the atmosphere. It is also due to fog on cool nights.
• Photochemical smog happens when nitrogen oxides and volatile organic compounds react together in the presence of sunlight as a catalyst and form ozone at lower levels.
• The effects of smog on human health and the environment are serious and harmful.
• The main components of photochemical smog are nitrogen oxides, Volatile Organic Compounds (VOCs), tropospheric ozone, and PAN (peroxyacetyl nitrate).

Note:

• Primary Pollutants: Those pollutants which are directly emitted from a source are called primary pollutants. Particulate matter, oxides of nitrogen, and toxic metals are all examples of primary pollutants as they can be directly associated with the burning of fossil fuels, volcanic eruptions or industrial effluents.
• Secondary Pollutants: Secondary pollutants are those pollutants that arise when primary pollutants react with one another or with other substances in the surroundings. Smog, which is the combination of smoke and fog is an example of a secondary pollutant.

The correct answer is Cadmium pollution.

Key Points

•  Itai-Itai, which literally translates to ‘it hurts, it hurts’ is the name given to cadmium poisoning.
• The disease Itai Itai is caused by Cadmium.
• This name was given to the disease by the locals of Toyama Prefecture of Japan in 1912.
• This disease was recognized as the Four Big Pollution Diseases of Japan.
• Cadmium is a naturally occurring toxic heavy metal.
• It is an extremely toxic industrial and environmental pollutant classified as a human carcinogen.
• It is used in the manufacturing of NiCd rechargeable batteries.

Additional Information 

The correct answer is Nitrogen oxide.

Key Points

• Greenhouse gases(GHGs) are a group of compounds that are responsible for absorbing heat (longwave radiation) in the atmosphere, keeping the Earth's surface warmer by allowing direct sunlight (relative short wave energy) to reach the Earth’s surface.
• Most Prominent Green House Gases:
  • Water vapour
  • Carbon Dioxide, CO2
  • Methane, CH4
  • Nitrous Oxide, N₂O (and NOT Nitrogen Oxide)
  • Ozone, O3
• Other GHGs are carbon monoxide, fluorinated gases, chlorofluorocarbons (CFCs), black carbon (soot), and brown carbon.
• Amongst all the greenhouse gases, only water vapour can absorb both incoming (UV) and outgoing (infrared) radiation.
• If GHG emissions remain unchecked, by the end of this century, the global temperatures may increase by 5^oC, causing global warming.

The correct answer is Freon.

Key Points:Freon

• Freon is a simple fluorinated aliphatic organic compound that is used in commerce and industry.
• In addition to fluorine and carbon, Freons often contain hydrogen, chlorine, or bromine.
• Thus, Freons are types of chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and related compounds.
• The name Freon is a trademark registered by E.I. du Pont de Nemours & Company.
• The Freons are colorless, odorless, nonflammable, noncorrosive gases or liquids of low toxicity that were introduced as refrigerants in the 1930s.
• They also proved useful as propellants for aerosols and in numerous technical applications.
• Their low boiling points, low surface tension, and low viscosity make them especially useful refrigerants.
• They are extremely stable, inert compounds.

CONCEPT:

• Bio-Degradable:
  • Substances that are broken down by biological processes (bacteria) are said to be biodegradable. 
  • For example all living plants and animals, vegetables and fruits.
• Non-Bio- Degradable: Substances that are not broken down by biological processes(bacteria) are said to be non-biodegradable. These substances may be inert and simply persist in the environment for a long time or may harm the various members of the eco-system. For example Plastics, metals concrete, Nylon etc 

EXPLANATION:

• Nylon is a man-made fibre. In 1931, it was made without using any natural raw material (from plant or animal). It was prepared from coal, water and air. It was the first fully synthetic fibre. it is not biodegradable.
• Wool is obtained from animals, so it is biodegradable.
• Animals bones and tea leaves are also biodegradable.

Additional Information

The correct answer is Afforestation.

Key Points

• Afforestation:
  • Afforestation is the establishment of a forest or stands of trees in an area where there was no previous tree cover.
  • Many government and non-governmental organizations directly engage in programs of afforestation to create forests, increase carbon capture.
  • It enables investors to plant the kind of trees according to demand, advancing the quick propagation of particular sorts of trees.

Important Points

• Five Major Environment problems:
  • Genetic modification of food
  • Water (Acid Rain)
  • Loss of Biodiversity
  • Deforestation
  • Climate change

The correct answer is Union Carbide.

Key Points

• Bhopal Gas Tragedy:
  • It was a gas leak incident that happened in  India on 3rd December 1984.
  • The leakage of toxic methyl isocyanate gas at a Union Carbide plant was the cause of the Bhopal Gas Tragedy.
  • Union Carbide plant was owned by the Indian subsidiary of the American firm Union Carbide Corporation.
  • About 45 tons of the dangerous gas methyl isocyanate leaked from an insecticide plant.
  • Methyl isocyanate is an extremely toxic gas and its concentration in the air touches 21ppm (parts per million).
    • It can cause death within minutes of inhaling the gas.
  • The final death toll was estimated to be between 15,000 and 20,000.
  • Some half a million survivors suffered respiratory problems, eye irritation or blindness, and other maladies.

Additional Information Bhopal:

• Due to various natural and artificial lakes, it is known as the City of Lakes.
• It is also one of the greenest cities in India.
• It is the 16th largest city in India and 131st in the world.
• Bhojtaal is also known as Bada Talab is the oldest man-made lake in India.

The correct answer is "1984".

Key Points

• The Bhopal disaster is also referred to as the Bhopal gas tragedy.
• It was a chemical accident on the night of 2-3 December 1984 at the Union Carbide India Limited pesticide plant in Bhopal, Madhya Pradesh.
• It was India's first major industrial disaster.
• On December 3, 1984, more than 40 tons of methyl isocyanate (MIC) gas leaked from a pesticide plant, immediately killing at least 3,800 people and causing significant morbidity and premature death for many thousands more.

Additional Information

• Methyl Isocyanate (MIC)
  • Methyl Isocyanate is a colorless liquid used for making pesticides.
  • MIC is safe when maintained properly.
  • The chemical is highly reactive to heat.
  • When exposed to water, the compounds in MIC react with each other causing a heat reaction.

The correct answer is Nitrous oxide and Sulphur dioxide.

Key Points

• Acid Rain:-
  • ​Acid rain is the rainfall that has been acidified.
  • It is formed when oxides of sulfur and nitrogen react with the moisture in the atmosphere.
  • It is rain with a pH of less than 5.6.
  • Acid rain is particularly damaging to lakes, streams, and forests and the plants and animals that live in these ecosystems.

Important Points

• Sources of compounds causing acid rain:-
  • Natural sources:-
    • Seas and oceans,
    • volcanic eruptions,
    • Biological processes in the soil e.g., Decomposition of organic matter.
  • Man-made sources:-
    • Burning of coal (60% of SO2) and
    • Petroleum products (30% of SO2), and the smelting of metal sulfide ores to obtain the pure metals.
    • Industrial production of Sulfuric acid in metallurgical.
    • Chemical and fertilizer industries.
  • Natural sources:-
    • Lightening,
    • volcanic eruption.
    • Biological activity. 

The correct answer is Eutrophication.

Key Points​​

• Eutrophication occurs when excessive nutrients, particularly nitrogen and phosphorus, enter a water body. Hence, option 2 is correct.
• These nutrients promote the rapid growth of plants and algae, leading to:
  • Algal blooms, which can deplete oxygen in the water.
  • Decreased biodiversity as aquatic life struggles to survive due to low oxygen levels (hypoxia).
  • Water quality degradation, impacting ecosystems and human uses.
• Eutrophication can occur naturally over time but is often accelerated by human activities, such as agricultural runoff, sewage discharge, and industrial effluents.