MCQ (Practice) - Environmental Issues (Level 1) - Class 12 MCQ

Which of the following would not be a natural pollution?
To determine which option is not a natural pollution, let's analyze each option:
A: Occurrence of NO₂ in atmosphere
- NO₂ is a pollutant that is often produced by combustion processes, such as vehicle emissions and power plants.
- This is a human-induced pollution and not a natural pollution.
B: Forest fires
- Forest fires release large amounts of smoke, ash, and pollutants into the atmosphere.
- Forest fires are a natural pollution caused by natural processes like lightning strikes, volcanic activity, or human activities like campfires.
- Therefore, forest fires can be considered a natural pollution.
C: Eutrophication
- Eutrophication is the excessive growth of algae and plants in bodies of water due to high nutrient levels.
- It is caused by the release of excess nutrients, such as nitrogen and phosphorus, into the water from sources like agricultural runoff or wastewater treatment plants.
- While eutrophication can be influenced by human activities, it can also occur naturally.
- Therefore, eutrophication can be considered both a natural and human-induced pollution.
D: Occurrence of smog
- Smog is a type of air pollution that is characterized by a mixture of pollutants, such as nitrogen oxides, volatile organic compounds, and particulate matter.
- Smog is primarily caused by human activities, such as vehicle emissions, industrial processes, and the burning of fossil fuels.
- Smog is not considered a natural pollution as it is largely influenced by human activities.
Therefore, the correct answer is D: Occurrence of smog, as it is not a natural pollution.

The correct answer is C: Chlorofluorocarbon.
Chlorofluorocarbon (CFC) is a type of freon. Here is a detailed explanation:
What is freon?
- Freon is a generic term used to refer to a group of synthetic organic compounds that contain carbon, chlorine, and fluorine atoms.
- It is known for its non-toxic, non-flammable, and stable properties.
What is Chlorofluorocarbon (CFC)?
- Chlorofluorocarbon (CFC) is a specific type of freon that contains chlorine, fluorine, and carbon atoms.
- CFCs were commonly used in various industrial and consumer applications, such as refrigeration, air conditioning, aerosol propellants, and foam blowing agents.
Why is CFC harmful?
- Although CFCs have been widely used in the past, they have been found to have detrimental effects on the environment.
- When released into the atmosphere, CFCs can rise to the stratosphere, where they undergo photodissociation due to UV radiation from the sun.
- This process results in the release of chlorine atoms, which can then catalytically destroy ozone molecules in the ozone layer.
Conclusion:
- Freon is a generic term for a group of synthetic organic compounds.
- Chlorofluorocarbon (CFC) is a specific type of freon that contains chlorine, fluorine, and carbon atoms.
- CFCs have been widely used in various applications but are harmful to the environment due to their ozone-depleting properties.

Answer:

Metals and textiles are damaged by:

• Fluorides: Fluorides can cause corrosion and etching of metals and can degrade the quality of textiles.


• Carbon monoxide: While carbon monoxide is primarily known for its toxic effects on humans, it can also cause corrosion of metals.


• Aldehydes: Aldehydes can degrade the quality of textiles, but their direct impact on metals is less significant compared to other pollutants.


• Nitrogen oxides: Nitrogen oxides, including nitrogen dioxide (NO2), can cause corrosion and discoloration of metals. They can also deteriorate the quality of textiles.

Therefore, the correct answer is D: Nitrogen oxides.

The pollutant of automobile exhausts that affects the nervous system and produces mental diseases is Lead.
Explanation:
Lead is a toxic heavy metal that is released into the environment through the burning of fossil fuels, including gasoline used in automobiles. It can have detrimental effects on the nervous system and mental health, especially when exposed to high levels over a prolonged period.
Here is a detailed explanation of how lead affects the nervous system and contributes to mental diseases:
1. Lead exposure:
- Lead is released into the air through the combustion of leaded gasoline in automobiles.
- The exhaust emissions containing lead particles are then released into the environment.
2. Inhalation and ingestion:
- Lead particles can be inhaled directly into the lungs or ingested through contaminated food, water, or dust.
- Inhalation and ingestion are the primary routes of lead exposure for humans.
3. Absorption and distribution:
- Once lead enters the body, it can be absorbed into the bloodstream.
- Lead can cross the blood-brain barrier and accumulate in the brain and other organs.
4. Effects on the nervous system:
- Lead interferes with the normal functioning of neurotransmitters, which are chemicals that transmit signals in the brain.
- It can disrupt the development and functioning of the nervous system, particularly in children.
- Lead exposure has been linked to neurodevelopmental disorders, learning disabilities, and decreased IQ.
5. Mental diseases:
- Chronic lead exposure has been associated with an increased risk of mental diseases.
- Studies have shown a connection between lead exposure and conditions such as depression, anxiety, and attention-deficit/hyperactivity disorder (ADHD).
- Lead has also been linked to cognitive impairments, memory problems, and behavioral issues.
In conclusion, lead is a pollutant present in automobile exhausts that can have severe effects on the nervous system and contribute to the development of mental diseases. It is crucial to reduce lead emissions and take measures to prevent lead exposure to protect public health.

Pollution is –
A: Release of toxic/undesirable materials in the environment
- Pollution refers to the release of harmful substances or undesirable materials into the environment.
- These substances can be in the form of gases, liquids, or solids and can come from various sources such as industries, vehicles, and human activities.
B: Conservation of energy
- Conservation of energy refers to the practice of using energy efficiently and reducing energy consumption.
- While conservation of energy is important for sustainable living, it is not directly related to pollution.
C: Removal of topsoil
- Removal of topsoil, also known as soil erosion, is the process where the top layer of soil is washed or blown away.
- This can happen due to natural causes like wind and water, or as a result of human activities such as deforestation and improper land management.
- While soil erosion can have detrimental effects on agriculture and ecosystems, it is not a form of pollution.
D: All the above
- The correct answer is A: Release of toxic/undesirable materials in the environment.
- Pollution specifically refers to the introduction of harmful substances into the environment, which can cause damage to living organisms, ecosystems, and the overall environment.
In conclusion, pollution is the release of toxic or undesirable materials into the environment, and it does not include conservation of energy or removal of topsoil.

Ozone layer is disturbed by:


A: Large number of factories
- Factories release pollutants and chemicals into the atmosphere, including chlorofluorocarbons (CFCs) and halons, which are known to deplete the ozone layer.
- These substances accumulate in the stratosphere and break down ozone molecules, leading to the thinning of the ozone layer.
B: Supersonic jets
- Supersonic jets, such as Concorde, emit nitrogen oxides (NOx) at high altitudes.
- These nitrogen oxides can react with ozone molecules, causing depletion of the ozone layer.
C: Large number of automobiles
- Automobiles emit nitrogen oxides (NOx) and volatile organic compounds (VOCs) as byproducts of combustion.
- These pollutants can also contribute to the depletion of the ozone layer.
D: None of above
- This option implies that none of the mentioned factors are responsible for disturbing the ozone layer.
- However, it is important to note that human activities such as industrialization, transportation, and aviation have significantly contributed to ozone layer depletion.
Answer: B
- Supersonic jets, due to their emission of nitrogen oxides, have been identified as one of the factors that disturb the ozone layer.

Air pollution is caused by:



Smoke:
- Smoke from burning fossil fuels, such as coal, oil, and natural gas, contributes to air pollution.
- Industrial processes, such as manufacturing and power generation, release smoke and pollutants into the air.
- Smoke from wildfires and burning agricultural crops also contribute to air pollution.



Automobile exhausts:
- Emissions from vehicles, including cars, trucks, and motorcycles, contribute to air pollution.
- The combustion of gasoline and diesel fuels releases pollutants such as carbon monoxide, nitrogen oxides, and volatile organic compounds.
- Automobile exhausts are a significant source of air pollution, especially in urban areas with high levels of traffic.



Thermal Power Exhaust:
- Thermal power plants, which generate electricity by burning fossil fuels, release pollutants into the air.
- These power plants produce emissions such as sulfur dioxide, nitrogen oxides, and particulate matter, which contribute to air pollution.
- The exhaust from thermal power plants can travel long distances and impact air quality in surrounding areas.



All of the above:
- Air pollution is caused by a combination of smoke, automobile exhausts, and thermal power exhaust.
- These sources release various pollutants into the air, including particulate matter, nitrogen oxides, sulfur dioxide, carbon monoxide, and volatile organic compounds.
- The pollutants can have harmful effects on human health and the environment, leading to respiratory problems, cardiovascular issues, and environmental damage.
- It is important to reduce emissions from these sources and promote cleaner alternatives to mitigate air pollution and improve air quality.

Main air pollutant is CO - Carbon monoxide

• Carbon monoxide (CO) is a major air pollutant that is emitted from various sources such as vehicles, industrial processes, and the burning of fossil fuels.


• CO is a colorless and odorless gas that is produced when carbon-rich fuels do not burn completely due to insufficient oxygen.


• Exposure to high levels of CO can be harmful to human health as it reduces the oxygen-carrying capacity of the blood, leading to symptoms such as headaches, dizziness, and in severe cases, even death.


• CO is also a greenhouse gas and contributes to global warming and climate change.


• Efforts to reduce CO emissions include improving fuel combustion efficiency, implementing stricter emission standards for vehicles and industrial processes, and promoting the use of alternative energy sources.

Other air pollutants:

• Nitrogen dioxide (NO₂): This is produced from the burning of fossil fuels, particularly in vehicles and power plants. It contributes to the formation of smog and can cause respiratory problems.


• Sulfur dioxide (SO₂): This is mainly emitted from burning fossil fuels containing sulfur, such as coal and oil. It can cause respiratory and cardiovascular problems and contributes to the formation of acid rain.


• Carbon dioxide (CO₂): While CO₂ is not considered a primary air pollutant, it is a significant greenhouse gas that is primarily released from burning fossil fuels and deforestation. It is the main contributor to climate change.

Overall, while there are several air pollutants, carbon monoxide (CO) is considered one of the main pollutants due to its harmful effects on human health and contribution to climate change.

The PAN (Phenylazophenol) blocks the Hill reaction.
Explanation:
The Hill reaction is a light-dependent process that occurs in the chloroplasts of plants. It involves the transfer of electrons from water to a mobile electron carrier, such as NADP+, resulting in the production of ATP and NADPH. The Hill reaction is an essential step in photosynthesis.
Phenylazophenol (PAN) is a specific inhibitor of the Hill reaction. It acts by disrupting the electron transport chain, which prevents the transfer of electrons from water to the electron carrier. As a result, ATP synthesis and NADPH production are inhibited, leading to a decrease in the overall photosynthetic activity of the plant.
In summary, PAN blocks the Hill reaction by inhibiting electron transfer and subsequently preventing ATP synthesis and NADPH production.

Photochemical reaction and its product
Definition: A photochemical reaction is a chemical reaction that is initiated by the absorption of light. It involves the breaking and forming of chemical bonds.
Product of a photochemical reaction: The product of a photochemical reaction depends on the reactants involved. In this case, we need to identify the photochemical reaction product from the given options.
Examining the options:
A: Fluorides - This option does not specify any details about a photochemical reaction product. It is not a definitive answer.
B: CO and CO2 - These compounds can be products of combustion reactions, but they are not specifically associated with photochemical reactions.
C: SO2 - This compound is commonly associated with sulfur dioxide gas, which can be a product of various industrial processes. However, it is not a photochemical reaction product.
D: O3 - Ozone (O3) is a well-known product of photochemical reactions. When oxygen molecules (O2) are exposed to ultraviolet (UV) light, they can undergo a photochemical reaction to produce ozone. Ozone is an important component of the Earth's ozone layer and plays a crucial role in protecting us from harmful UV radiation.
Conclusion: The correct answer is D. Ozone (O3) is a photochemical reaction product.

To determine the meaning of the acronym P.A.N., we need to identify the correct option among the given choices:
A: Peroxy acetyl nitrite
B: Peroxy acetyl nitrate
C: Peroxy aceto-nitrile
D: Pyridine aceto-nitrite
We can eliminate options C and D since they do not match the acronym P.A.N. Next, we need to differentiate between options A and B.
To do this, we can break down the acronym P.A.N. and compare it with the options:
- P: Peroxy
- A: Acetyl
- N: Nitrite or Nitrate
From the breakdown, we can see that option B, Peroxy acetyl nitrate, matches the acronym P.A.N.
Therefore, the correct answer is B: Peroxy acetyl nitrate.

Atmospheric Pollutants Causing General Chlorosis

General chlorosis refers to the destruction of chlorophyll, which is responsible for the green color in plants. Several atmospheric pollutants can contribute to this condition, but the one that specifically causes general chlorosis is:

A. SO₂ (Sulfur Dioxide)

• Sulfur dioxide (SO₂) is a common atmospheric pollutant released from burning fossil fuels, particularly in power plants and industrial processes.


• When plants are exposed to high levels of SO₂ in the air, it can lead to general chlorosis and damage to plant tissue.


• SO₂ interferes with the process of photosynthesis, inhibiting the production of chlorophyll and affecting plant growth and development.


• General chlorosis caused by SO₂ exposure can result in yellowing or whitening of leaves, stunted growth, and reduced plant productivity.

Other atmospheric pollutants, such as hydrocarbons, carbon monoxide (CO), and carbon dioxide (CO₂), may also have negative impacts on plants and the environment, but they do not directly cause general chlorosis.

Therefore, the correct answer is A. SO₂ (Sulfur Dioxide).

Pollution Sources of C.F.C:
There are several sources of C.F.C. (chlorofluorocarbon) pollution. The correct answer is D, which means all of the following sources contribute to C.F.C. pollution:
Fire extinguishers:
- Fire extinguishers contain C.F.C. as a propellant, which can be released into the atmosphere when used.
Refrigerators:
- Older refrigerators and air conditioning units used C.F.C. as a refrigerant. When these appliances are not properly disposed of, C.F.C. can be released into the environment.
Jet aircrafts:
- Jet aircrafts have historically used C.F.C.-based substances as refrigerants and propellants. Although the use of C.F.C. in aircrafts has been phased out, older aircrafts may still emit C.F.C. into the atmosphere.
Therefore, the correct answer is D, as all of these sources can release C.F.C. into the environment and contribute to C.F.C. pollution. It is important to address these sources of pollution in order to protect the ozone layer and reduce the harmful effects of C.F.C. on the environment.

PAN (peroxyacetyl nitrate) - A Secondary Pollutant in Photochemical Smog
Photochemical smog is a type of air pollution that is formed when pollutants such as nitrogen oxides and volatile organic compounds react with sunlight. PAN, or peroxyacetyl nitrate, is an important constituent of photochemical smog. It is formed through a series of chemical reactions involving volatile organic compounds (VOCs), nitrogen oxides (NOx), and sunlight.
Definition of Secondary Pollutant:
A secondary pollutant is formed through chemical reactions in the atmosphere. These pollutants are not emitted directly into the air but are formed when primary pollutants undergo chemical reactions in the presence of sunlight and other atmospheric conditions.
Explanation:
PAN is considered a secondary pollutant in photochemical smog for the following reasons:
1. Formation: PAN is formed through a series of reactions involving VOCs and NOx in the presence of sunlight. It is not directly emitted into the atmosphere.
2. Chemical Reactions: PAN is formed when volatile organic compounds (VOCs) react with nitrogen oxides (NOx) in the presence of sunlight. This reaction leads to the production of PAN as a secondary pollutant.
3. Atmospheric Transformation: Once formed, PAN undergoes further reactions in the atmosphere, contributing to the complex chemical reactions that occur in photochemical smog.
4. Harmful Effects: PAN is known to cause eye and respiratory irritation in humans. It can also damage vegetation and contribute to the formation of ground-level ozone, which is a harmful air pollutant.
In conclusion, PAN is an important constituent of photochemical smog and is considered a secondary pollutant. It is formed through chemical reactions involving VOCs, NOx, and sunlight. PAN contributes to the harmful effects of photochemical smog and is a significant component of air pollution in urban areas.

Smog is produced due to various factors:
- Smoke: The combustion of fossil fuels, such as coal and oil, releases smoke particles into the air. These smoke particles contribute to the formation of smog.
- Fog: When fog combines with smoke particles and other pollutants in the air, it can lead to the formation of smog. Foggy conditions trap pollutants close to the ground, preventing them from dispersing and contributing to the formation of smog.
- Air pollution: Emissions from vehicles, industrial processes, and power plants release pollutants such as nitrogen oxides and volatile organic compounds into the air. These pollutants can react with sunlight and other chemicals in the atmosphere to form smog.
- Chemical reactions: Chemical reactions between pollutants in the air, particularly in the presence of sunlight, can lead to the formation of smog. Nitrogen oxides and volatile organic compounds can react to form ground-level ozone, a key component of smog.
- Weather conditions: Certain weather conditions, such as stagnant air and temperature inversions, can contribute to the formation and persistence of smog. Stagnant air prevents pollutants from dispersing, while temperature inversions trap pollutants close to the ground.
Overall, smog is a complex mixture of pollutants that is formed through the interaction of various factors, including smoke, fog, air pollution, chemical reactions, and weather conditions. It is important to reduce emissions and take measures to improve air quality in order to minimize the formation and impact of smog.

Human Disease Aggravated by Atmospheric Pollution - Bronchitis

Atmospheric pollution can have detrimental effects on human health, especially on the respiratory system. One of the diseases that can be aggravated by atmospheric pollution is bronchitis. Here's a detailed explanation:

What is Bronchitis?

• Bronchitis is an inflammation of the bronchial tubes, which are the airways that carry air to and from the lungs.


• It can be acute or chronic, with chronic bronchitis being a long-term condition.


• Common symptoms include coughing, wheezing, chest discomfort, and excessive mucus production.

How is Bronchitis Aggravated by Atmospheric Pollution?

• Atmospheric pollution, particularly air pollutants such as particulate matter (PM), nitrogen dioxide (NO2), and sulfur dioxide (SO2), can worsen the symptoms and severity of bronchitis.


• These pollutants irritate the airways and can cause inflammation, making it harder for individuals with bronchitis to breathe.


• Exposure to high levels of air pollution can also lead to the development of bronchitis in otherwise healthy individuals.

Effects of Atmospheric Pollution on Bronchitis

• Increased respiratory symptoms: Individuals with bronchitis may experience increased coughing, wheezing, and shortness of breath due to the irritants present in polluted air.


• Exacerbation of the condition: Atmospheric pollution can trigger exacerbations or flare-ups of bronchitis, leading to more severe symptoms and a prolonged recovery period.


• Reduced lung function: Prolonged exposure to air pollution can result in decreased lung function, making it even more challenging for individuals with bronchitis to breathe properly.

In conclusion, atmospheric pollution can aggravate bronchitis and worsen its symptoms. It is essential to minimize exposure to polluted air and take appropriate measures to protect respiratory health, especially for individuals with bronchitis.

The gas released in the Bhopal tragedy was MIC (Methyl Isocyanate).
Explanation:
The Bhopal tragedy, also known as the Bhopal gas disaster, occurred on the night of December 2-3, 1984, in Bhopal, India. It is considered one of the world's worst industrial disasters. The gas leak was caused by the release of a highly toxic substance called Methyl Isocyanate (MIC) from the Union Carbide India Limited (UCIL) pesticide plant.
MIC is an extremely hazardous chemical used in the production of pesticides. When released in gas form, it can cause severe respiratory distress, eye irritation, and damage to internal organs. The gas leak in Bhopal resulted in the immediate death of thousands of people and left many others with long-term health problems.
The release of MIC in the Bhopal tragedy was a result of a combination of factors, including inadequate safety measures, poor maintenance, and lack of proper emergency protocols. The incident highlighted the need for strict industrial safety regulations and raised awareness about the potential dangers of chemical plants.
Overall, the gas released in the Bhopal tragedy was MIC, a highly toxic substance that had devastating effects on the surrounding population.

Lichens as Indicators of SO₂ Pollution
Lichens are organisms that consist of a symbiotic relationship between fungi and algae or cyanobacteria. They are highly sensitive to environmental conditions and can serve as reliable indicators of pollution, particularly SO₂ pollution. Here's why:
1. Tolerance to sulfur dioxide: Lichens are highly sensitive to SO₂ pollution and can only survive in areas with low levels of this pollutant. They are unable to tolerate high concentrations of SO₂, making them excellent indicators of its presence.
2. Visible changes in lichen morphology: When exposed to SO₂ pollution, lichens undergo noticeable changes in their morphology. They may become discolored, with a bleached or yellow appearance. These visible changes make it easy to identify areas with high levels of SO₂ pollution.
3. Effects on lichen diversity: SO₂ pollution can have a significant impact on lichen diversity. Areas with high levels of SO₂ pollution often have a lower diversity of lichen species compared to areas with cleaner air. Monitoring lichen diversity can provide valuable information about the extent of SO₂ pollution in a given area.
4. Sensitive bioindicators: Lichens are considered bioindicators because they respond quickly and visibly to changes in environmental conditions. Their sensitivity to SO₂ pollution makes them excellent indicators of air quality and can help identify areas where pollution control measures may be necessary.
In conclusion, lichens are best indicators of SO₂ pollution. Their sensitivity to this pollutant, visible morphological changes, impact on lichen diversity, and status as sensitive bioindicators make them valuable tools for monitoring and assessing air quality.

Common Indicator Organism of Water Pollution:
There are various indicator organisms that are used to determine the presence of water pollution. These organisms can provide insights into the overall water quality and the potential presence of harmful contaminants. One of the most commonly used indicator organisms is Escherichia coli (E. coli). Here are some details about E. coli as a common indicator organism of water pollution:
1. Escherichia coli (E. coli):
- E. coli is a type of bacteria that is naturally present in the intestines of warm-blooded animals, including humans.
- The presence of E. coli in water indicates fecal contamination, as it is primarily found in the feces of animals.
- Elevated levels of E. coli in water can suggest the presence of harmful pathogens that may cause waterborne diseases.
- Monitoring E. coli levels in water is a common practice to assess the overall microbiological quality of water sources.
- The detection of E. coli in water samples may trigger further investigation and remediation measures to ensure public health and safety.
Other organisms mentioned in the options are not commonly used as indicator organisms for water pollution:
2. Entamoeba histolytica:
- Entamoeba histolytica is a parasitic amoeba that can cause amoebiasis, a disease that affects the intestines.
- While it can be an indicator of fecal contamination, it is less commonly used for water quality assessment compared to E. coli.
3. Eichhornia crassipes:
- Eichhornia crassipes, commonly known as water hyacinth, is an aquatic plant.
- It is not an indicator organism of water pollution, but its excessive growth in water bodies can be a sign of nutrient pollution.
4. Lemna paucicostata:
- Lemna paucicostata, also known as duckweed, is a small floating aquatic plant.
- Similar to Eichhornia crassipes, it is not an indicator organism of water pollution, but its abundance can indicate nutrient enrichment in water bodies.
Therefore, among the options provided, the correct answer is Escherichia coli (E. coli) as a common indicator organism of water pollution.

Explanation:

The spraying of DDT (Dichloro-Diphenyl-Trichloroethane) can result in pollution of the environment, particularly in the following ways:

Air pollution:

• DDT is volatile and can easily evaporate into the air.


• When DDT is sprayed, it can be carried by wind and dispersed over a wide area.


• Inhaling DDT can be harmful to human health and can cause respiratory problems.

Water pollution:

• DDT can be washed off from the sprayed area by rainwater or irrigation.


• The runoff containing DDT can enter nearby water bodies such as lakes, rivers, and streams.


• DDT is persistent in water and can bioaccumulate in aquatic organisms, leading to harmful effects on the ecosystem.

Soil pollution:

• DDT can seep into the soil and persist for a long time.


• It can contaminate the soil, affecting the growth of plants and other organisms.


• DDT can also be taken up by plants, leading to potential risks for animals and humans consuming these plants.

Therefore, the correct answer is B: Air, water, and soil as DDT spraying can result in pollution of all these environmental components. It is important to use DDT and other pesticides judiciously to minimize their impact on the environment and human health.

Extreme Example of Noise Pollution:

A: Sonic booms produced by aircraft

Noise pollution refers to the excessive or disturbing noise that can have negative effects on human health and well-being. While all the options listed can contribute to noise pollution, the most extreme example is sonic booms produced by aircraft. Here's why:

1. Intensity: Sonic booms are extremely loud and intense sounds that can reach up to 200 decibels. This level of noise is significantly higher than the threshold of pain for human ears, causing immediate discomfort and potential damage to hearing.


2. Widespread Impact: Sonic booms can be heard over a large area, affecting a wide range of people and communities. The noise can disrupt daily activities, disturb sleep patterns, and lead to increased stress levels.


3. Unpredictability: Unlike other sources of noise pollution, such as traffic or industrial operations, sonic booms occur unexpectedly and cannot be avoided or controlled by individuals. This lack of control can lead to feelings of helplessness and anxiety.


4. Environmental Impact: Sonic booms can also have detrimental effects on wildlife, disrupting their natural habitats and causing stress and disorientation.


5. Regulation: Due to the extreme nature of sonic booms, there are strict regulations in place to minimize their occurrence and impact. Measures such as supersonic flight restrictions over populated areas aim to reduce the exposure and negative consequences of this type of noise pollution.

While other sources of noise pollution, such as rock music, industrial operations, and traffic, can also have adverse effects on individuals and the environment, sonic booms produced by aircraft are considered an extreme example due to their high intensity, widespread impact, and unpredictable nature.

Renewable and Non-Renewable Sources of Energy
Renewable Sources of Energy:
- Renewable sources of energy are those that can naturally replenish themselves within a short period of time, making them sustainable and environmentally friendly.
- These sources are considered to be infinite or practically inexhaustible.
Non-Renewable Sources of Energy:
- Non-renewable sources of energy are those that are finite and depleting over time.
- These sources are formed over millions of years and cannot be replenished within a short period of time.
Identifying the Non-Renewable Source:
- We need to identify the option that does not fall under the category of renewable sources of energy.
- Let's analyze each option to determine which one is non-renewable.
A: Forest:
- Forests are considered renewable sources of energy as they can be regrown or replanted.
- Trees can be harvested for timber or used as a source of biomass energy.
- Forests have the ability to renew themselves through natural processes.
B: Coal:
- Coal is a fossil fuel and is classified as a non-renewable source of energy.
- It is formed from the remains of plants and trees that lived millions of years ago.
- The extraction and burning of coal release carbon dioxide and other pollutants, contributing to climate change.
C: Water:
- Water is a renewable source of energy in the form of hydropower.
- It is harnessed by using the energy of flowing or falling water to generate electricity.
- The water cycle ensures a continuous supply of water, making it a sustainable source.
D: Forest organism:
- This option is not clear and might be referring to the organisms within a forest.
- Forest organisms can be considered part of the overall forest ecosystem, which is renewable.
- However, if this option refers to individual organisms, it is not a significant source of energy and can be considered negligible.
Conclusion:
- The non-renewable source of energy among the given options is B: Coal.
- Coal is formed over millions of years and cannot be replenished within a short period of time.
- It is a major contributor to greenhouse gas emissions and air pollution.
- Transitioning towards renewable sources of energy is essential for a sustainable future.

Introduction:
Nitrate fertilizers are commonly used in agriculture to enhance crop growth and yield. However, excessive use of these fertilizers can have detrimental effects on the environment and human health. In children, the intensive use of nitrate fertilizers has been linked to the development of a specific disease known as methaemoglobinemia.
Methaemoglobinemia:
Methaemoglobinemia is a condition characterized by the increased presence of methaemoglobin, a form of hemoglobin that is unable to bind and transport oxygen effectively. This results in a reduced capacity of the blood to deliver oxygen to the body's tissues.
Cause:
The intensive use of nitrate fertilizers can lead to an accumulation of nitrates in the soil and water sources. When consumed by children, these nitrates can be converted into nitrites in the body. Nitrites have the ability to convert hemoglobin to methaemoglobin, leading to the development of methaemoglobinemia.
Symptoms:
Children with methaemoglobinemia may exhibit the following symptoms:
- Bluish discoloration of the skin, lips, and nails (cyanosis)
- Rapid breathing and heart rate
- Fatigue and weakness
- Headaches and dizziness
- Seizures
Prevention:
To prevent methaemoglobinemia caused by nitrate fertilizers, the following measures can be taken:
- Limit the use of nitrate fertilizers and opt for organic alternatives.
- Ensure proper storage and disposal of fertilizers to prevent contamination of water sources.
- Test drinking water sources for nitrate levels and use appropriate treatment methods if necessary.
- Educate parents and caregivers about the risks associated with nitrate exposure and the importance of monitoring children's nitrate intake.
Conclusion:
Methaemoglobinemia in children can be caused by the intensive use of nitrate fertilizers. It is important to raise awareness about the potential health risks associated with nitrate exposure and take necessary precautions to prevent the development of this disease.

The noise created at the launching of space rocket measures around 180 dB.
Explanation:
- When a space rocket is launched, it produces an enormous amount of noise due to the powerful engines and the explosive fuel combustion.
- The noise level is measured in decibels (dB), which is a logarithmic unit used to express the intensity of sound.
- The noise generated during a space rocket launch is extremely loud and can cause hearing damage if proper precautions are not taken.
- The noise level at a rocket launch can vary depending on factors such as the size and type of the rocket, distance from the launch site, and atmospheric conditions.
- However, on average, the noise level at a space rocket launch is estimated to be around 180 dB.
- To put this into perspective, normal conversation is around 60 dB, a rock concert is around 120 dB, and a jet engine at a close distance is around 140 dB.
- Therefore, the noise created at the launching of a space rocket is significantly higher than these levels, making it an incredibly loud and powerful sound.

Inadequate drainage in soil can lead to:
1. Salination:
- When there is inadequate drainage in the soil, excessive water accumulates, leading to an increase in the water table.
- As a result, the excess water dissolves and carries salts from the soil surface downwards.
- This process is known as salination, and it can result in the accumulation of harmful salts in the soil, making it less fertile and inhibiting plant growth.
2. Floods:
- Inadequate drainage can cause water to accumulate on the surface of the soil, especially during heavy rainfall or melting snow.
- When the soil is unable to absorb or drain the excess water, it can lead to flooding.
- Floods can damage crops, infrastructure, and properties, and pose a threat to human lives.
3. Soil erosion:
- When water is unable to drain properly from the soil, it can cause erosion.
- The excess water flows across the surface, carrying away the topsoil and nutrients.
- This can lead to the loss of fertile soil, reduced agricultural productivity, and increased sedimentation in rivers and water bodies, impacting aquatic ecosystems.
4. Aridity:
- Inadequate drainage can lead to waterlogging in the soil, which can result in poor aeration and root growth.
- Waterlogged soil becomes compacted and, in extreme cases, can lead to oxygen deprivation for plants.
- This can cause plants to wilt, become stunted, or even die, leading to aridity in the affected areas.
Therefore, inadequate drainage in soil can have various negative consequences such as salination, floods, soil erosion, and aridity.

Causes of Leukaemia
Leukaemia, a type of cancer that affects the blood and bone marrow, can be caused by various factors. However, out of the options given, the correct answer is A: Sr⁹⁰. Here is a detailed explanation:
1. Leukaemia:
Leukaemia is a cancer of the blood-forming tissues, particularly the bone marrow and the lymphatic system. It involves the overproduction of abnormal white blood cells, which affects the body's ability to fight infections.
2. Causes of Leukaemia:
Leukaemia can be caused by a combination of genetic and environmental factors. Some potential causes include:
- Genetic predisposition: Certain genetic abnormalities can increase the risk of developing leukaemia.
- Radiation exposure: Exposure to high levels of ionizing radiation, such as that experienced during nuclear accidents or radiation therapy, can increase the risk of leukaemia.
- Chemical exposure: Exposure to certain chemicals, such as benzene and some chemotherapy drugs, has been linked to leukaemia.
- Viral infections: Some viral infections, such as the human T-cell lymphotropic virus (HTLV-1) and Epstein-Barr virus (EBV), have been associated with certain types of leukaemia.
3. Sr⁹⁰:
Strontium-90 (Sr⁹⁰) is a radioactive isotope of strontium that is produced during nuclear fission. It is a beta emitter and has a half-life of about 29 years. Sr⁹⁰ can be released into the environment through nuclear weapons testing, nuclear power plant accidents, and the improper disposal of nuclear waste.
4. Sr⁹⁰ and Leukaemia:
Exposure to high levels of Sr⁹⁰ has been linked to an increased risk of developing leukaemia. The beta particles emitted by Sr⁹⁰ can penetrate the body and damage the DNA in bone marrow cells, leading to the development of cancer.
In conclusion, while leukaemia can have multiple causes, Sr⁹⁰ is one of the factors that can increase the risk of developing this type of cancer. It is important to minimize exposure to radiation and other known risk factors to reduce the chances of developing leukaemia.

Explanation:
The radioactive isotope Strontium-90 (Sr90) is deposited in the bones of the human body through the food chain. Here's a detailed explanation:
1. Food Chain:
- Strontium-90 enters the environment through nuclear explosions, nuclear accidents, and nuclear waste.
- It is then absorbed by plants from the soil and water, and is incorporated into their tissues.
2. Ingestion:
- Humans consume these plants, either directly or indirectly through consuming animals that have fed on these plants.
- When humans ingest food or water containing Strontium-90, it is absorbed by the body.
3. Distribution in the Body:
- Once absorbed, Strontium-90 behaves chemically similarly to calcium.
- It is deposited in bones and teeth, as the body mistakes it for calcium and incorporates it into the growing bone structure.
4. Radioactivity and Health Effects:
- Strontium-90 is a radioactive substance and emits beta particles during its decay.
- These beta particles can damage nearby cells and tissues, increasing the risk of bone cancer and leukemia.
Conclusion:
- In summary, radioactive Strontium-90 (Sr90) is deposited in the bones of the human body through the food chain.
- It is important to minimize exposure to Strontium-90 and other radioactive substances to protect our health.

Introduction:
The atomic bomb was a devastating weapon that was used during World War II. It was developed as part of the Manhattan Project, a top-secret research project undertaken by the United States. The bomb was eventually used in combat, resulting in catastrophic consequences. The exact year of its use is a crucial historical detail.

The atomic bomb was used during World War II in 1945. The correct answer is B.
Explanation:
The use of the atomic bomb during World War II was a turning point in the history of warfare. Here is a detailed explanation of why the bomb was used in 1945:
- Development of the atomic bomb: The Manhattan Project, which began in 1939, aimed to develop an atomic bomb. Scientists such as Robert Oppenheimer and Enrico Fermi worked on the project, and tremendous progress was made in the development of the bomb.
- The decision to use the bomb: As the war progressed, the United States faced the decision of whether or not to use the atomic bomb. The development of this weapon had cost a significant amount of resources and effort, and it was believed that using it could bring a swift end to the war and save lives.
- The bombings of Hiroshima and Nagasaki: On August 6, 1945, the United States dropped an atomic bomb on the Japanese city of Hiroshima. The devastation was immense, and an estimated 140,000 people were killed. Three days later, on August 9, a second atomic bomb was dropped on Nagasaki, resulting in the deaths of approximately 70,000 people.
- Aftermath: The bombings of Hiroshima and Nagasaki led to Japan's unconditional surrender on August 15, 1945, effectively ending World War II. The use of the atomic bomb had a profound impact on the world's perception of warfare and the use of nuclear weapons.
In conclusion, the atomic bomb was used during World War II in 1945. Its use in the bombings of Hiroshima and Nagasaki had a significant impact on the outcome of the war and forever changed the course of history.

Radiation hazard or nuclear pollution
Radiation hazard or nuclear pollution is considered the ultimate environmental hazard and the most outstanding danger for the survival of living beings on this planet. Here is a detailed explanation:
1. Radiation Hazard:
- Nuclear power plants and nuclear accidents, such as Chernobyl and Fukushima, release harmful radiation into the environment.
- Radiation exposure can cause various health problems, including cancer, genetic mutations, and reproductive disorders.
- It can contaminate air, water, and soil, affecting ecosystems and biodiversity.
2. Long-term Impacts:
- Nuclear waste, which remains hazardous for thousands of years, poses a significant challenge in terms of disposal and containment.
- The long half-life of radioactive materials means that their effects can persist for generations, posing a continuous threat to living beings.
3. Global Impact:
- Nuclear pollution does not recognize borders and can spread across continents through air and water currents.
- It poses a threat to both human and animal populations, as well as the overall ecological balance.
4. Potential for Catastrophic Accidents:
- Although safety measures are in place, the risk of accidents and meltdowns in nuclear power plants cannot be completely eliminated.
- A major nuclear accident can have devastating consequences, causing widespread contamination and long-term environmental damage.
Conclusion:
Radiation hazard or nuclear pollution is the most outstanding danger for the survival of living beings due to its long-term impacts, global reach, and potential for catastrophic accidents. It is crucial to prioritize the development of safer and sustainable energy alternatives to mitigate this environmental hazard.