Air Pollution: Important Questions & Answers with Detailed Explanation

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Very Short Answers Type Questions (1 mark)

Ques. What do you understand about air pollution? 

Ans. A type of pollution in which disproportionate levels of hazardous components are present in the air around us is called air pollution. 

Ques. What are the constituent particles of air pollutants?

Ans. The substances which are responsible for causing air pollution are called air pollutants. These include:

• Sulfur dioxide
• Ozone 
• Carbon Monoxide
• Nitrogen dioxide
• Ammonia
• Particulate Matter

Ques. What do you understand about contaminants?

Ans. Any substance that is undesirable and can damage the natural environment is called a contaminant. These compounds impact both living and non-living things in their surroundings.

Ques. Is there any organism used as a natural indicator of air pollution?

Ans. Yes, the natural indicator of air pollution is lichen, which is formed by the symbiotic association of fungus and algae. These structures are sensitive to sulfur oxide and are grown on rocks. 

Ques. What are the main causes of climate change?

Ans. Continuous fluctuations in weather and temperature conditions are referred to as climate change. Climate change is primarily caused by excessive human activity, and the combustion of fossil fuels like coal, oil, and gas.

Also check: Effects of Climate Change

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Short Answers Type Questions (2 marks)

Ques. What do you understand about particulate matter?

Ans. The term "particulate matter," or PM, describes a diverse mixture of liquid droplets and microscopic particles that are deposited in the atmosphere. These particles may consist of various chemicals and vary greatly in size.

Ques. What are the types of particulate matter?

Ans. The concentration of particulate matter determines the severity of air pollution. They are categorized into two types: 

• PM 10: These are particulate matter of relatively big size and whose diameter is around 10 micrometers. 

• PM 2.5: The particulate matter whose diameter is around 2 micrometers is called PM 2.5. 

Ques. What are the types of air pollutants? 

Ans. Two types of air pollutants that are responsible for air pollution are: 

• Primary Pollutants: When contaminants causing air pollution are directly released into the air, they are called primary pollutants. The example includes the release of sulfur dioxide and nitrogen oxides that cause acid rain. 
• Secondary Pollutants: The pollutants formed by the intermixing of one or more primary pollutants are considered secondary pollutants. For example, smog is formed when smoke and fog are intermixed. 

Ques. What do you mean by global warming?

The abnormal increase in the temperature of the earth’s atmosphere is called global warming. It is the root cause of both the greenhouse effect and climate change. It results from:

• Increased use of greenhouse gases
• Rising sea levels
• Volcanic activity
• Deforestation
• Overuse of fossil fuels

Ques. What is acid rain? 

Ans. A biological process that starts when pollutants like nitrogen oxides and sulfur dioxide are released into the atmosphere is called acid rain. An excellent strategy for preventing acid rain is to generate electricity without using fossil fuels. Renewable sources of energy, like solar and wind power, can be used in their place.

Ques. What is smog, and what are its types?

Ans. When smoke and fog are mixed in the air, it forms smog. It is an indicator of air pollution. Smog is categorized into two types: 

• Classical Smog: This type of smog is very common and is usually seen in humid climates. 

• Photochemical Smog: This is usually seen in dry, and sunny climates. 

Ques. How can we identify clean and contaminated air?

Ans. Contaminated air and clean air can only be distinguished in terms of composition. The addition of any undesirable or harmful elements in this composition may contaminate the air and cause air pollution. The composition of pure air is as follows: 

• Nitrogen: 78%
• Oxygen: 21%
• Carbon dioxide: 0.03%
• Other Gases: >0.17%

Constituents of pure air

Ques. The severity of air pollution is shown by AQI: What is it?

Ans. AQI stands for Air Quality Index, which records the quality of air on a routine basis. Moreover, with the help of AQI, we can get overall data about the purity of the air and related health risks. It also assesses the potential health effects of inhaling contaminated air. The representation of AQI of a particular areas is done with the help of different colours as: 

• Green (AQI range: 0-50): Air quality is good and clean.
• Yellow (AQI range: 51-100): Air quality is moderate.
• Orange (AQI range:101-150): Unhealthy
• Red (AQI range: 151-200): Unhealthy
• Purple (AQI range: 201-300): Unhealthy
• Maroon (AQI range: 300 or higher): Hazardous and may cause severe loss of biodiversity. 

Also check: Global Warming

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Long Answers Type Questions (3 marks)

Ques. What are the preventive measures to reduce air pollution?

Ans. Air pollution has become an alarming environmental problem in both developed and underdeveloped countries. Following are some of the ways through which air pollution can be reduced: 

• The planting of more and more trees (afforestation) can contribute to a reduction in atmospheric carbon dioxide emissions.
• Reducing reliance on fossil fuels can be achieved by switching to renewable energy sources like wind, solar, etc. 

Ques. What are the harmful effects of air pollutants?

Ans. The effects of air pollution can be seen almost everywhere around the globe. The harmful effects of air pollution are not just limited to humans; they also create an ecological imbalance by damaging wildlife and nature. Following are some of the major environmental problems caused by air pollution: 

• Climate Change: Changes in temperature and air quality are the main causes of climate change. 
• Acid Rain: Sulfur dioxide and nitrogen oxides are the gases that cause acid rain. These gases are released by thermal plants, buses, trucks, etc. in excess amounts and degrade the air quality. 
• Global Warming: The excessive use of greenhouse gases such as carbon dioxide, CFCs, and HCFs causes global warming. 

Ques. Which is the most polluted city in India due to air pollution?

Ans. Delhi has topped the list of the most polluted cities in India, as per the recent report released by the World Air Quality Ranking 2024. 

This graph shows the top eight world’s most polluted cities published in the World Air Quality Ranking 2024 based on annual average particulate matter concentrations (PM 2.5) in μg/m3.

Check Here: Acid Rain Questions & Answers

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Very Long Answer Type Questions (5 marks)

Ques. What are the sources of air pollution?

Ans. Based on the air pollutants, there are two main sources of air pollution: 

1. Natural Sources

Air pollution, which is caused by the adverse effects of natural calamities such as volcanic eruptions, methane combustion, and forest fires, is called natural sources of air pollution. 

2. Anthropogenic Source

Air pollution, which is caused by continuous human activities such as deforestation, excessive use of greenhouse gases, and combustion of toxic substances such as polyethylene, etc. is called the anthropogenic source of air pollution. 

Ques. What are the ways to control air pollution to save the environment?

Ans. The rising level of air pollution is associated with global environmental concerns such as global warming, depletion of the ozone layer, etc. 

Pollution can be reduced by making better use of raw materials, water energy, and other resources. Moreover, there are some more ways to control air pollution:

• Switching to public transport
• Adopting the use of electric vehicles
• Implementing green hydrogen-based technologies
• Sustainable use of resources such as fuels and energy

Ques. Write a short note on ozone layer depletion & how it causes potential risk to the environment. 

Ans. Ozone is a protective layer present between 15 and 30km above the earth’s surface in the stratosphere. It protects living organisms from harmful ultraviolet radiation coming from sun rays. However, the thinning of the ozone layer is associated with various environmental problems. Thus, it has now become a great concern for environmentalists. 

The effects of ozone depletion can be seen as: 

• Impact on living organisms: Living organisms like birds, animals, and humans are adversely affected by ozone layer depletion. In the absence of this layer, UV radiation will directly fall on the skin, which will cause serious skin diseases or cancer.
• Impact on Environment: Harmful UV rays falling on the earth's surface directly affect the normal growth and development of plants.