Pollutants and Pollution: NBSE Class 11 Environment Education

Leave a Comment

Get notes, summary, questions and answers, MCQs, extras, and PDFs of Chapter 11 “Pollutants and Pollution” which is part of NBSE Class 11 Environment Education. However, the notes should only be treated as references and changes should be made according to the needs of the students.

Summary

The chapter on “Pollutants and Pollution” provides a comprehensive overview of environmental pollution and its various forms. Pollution is defined as the undesirable changes in the physical, chemical, and biological characteristics of the environment that negatively affect living beings. The sources of pollution are both natural and man-made, often resulting from urbanization, industrial activities, and the overuse of natural resources.

Pollutants are substances or forms of energy that cause environmental degradation. They are categorized into different types based on their nature of release, biodegradability, and state (solid, liquid, or gaseous). For example, primary pollutants are directly released into the environment, such as smoke or chemicals from industrial waste, while secondary pollutants form through chemical reactions, like photochemical smog.

The chapter covers the different types of pollution, including air, water, soil, noise, and radiation pollution. Air pollution, for instance, is highlighted as a major concern in industrial cities. It is caused by both natural events, such as volcanic eruptions, and human activities like the burning of fossil fuels. The consequences include health hazards, global warming, and ozone layer depletion.

Water pollution is another critical issue discussed, arising from the discharge of harmful substances into water bodies. This pollution makes water unsafe for drinking and harmful to aquatic life. The chapter also addresses soil pollution, which occurs due to the deposition of harmful chemicals from industrial and agricultural activities. Soil pollution affects crop production and can lead to the contamination of food supplies.

Textbook solutions

Multiple-Choice Questions

1. Identify biodegradable pollutants from the following.

(a) Lead
(b) Plastic
(c) Paper
(d) Pesticide

Answer: (c) Paper

2. An odourless, colourless gas produced by incomplete oxidation is

(a) Ozone
(b) Carbon dioxide
(c) Sulphur dioxide
(d) Carbon monoxide

Answer: (d) Carbon monoxide

3. The Central Pollution Control Board maintains

(a) pollution per square kilometer population.
(b) records of atmospheric pollution levels.
(c) only air pollution levels.
(d) the health of the residents of an area.

Answer: (b) records of atmospheric pollution levels.

4. Which of the following causes plasmolysis and collapse of epidermal cells of leaves and results in glazing of leaves?

(a) Ammonia
(b) Hydrogen chloride
(c) Sulphur dioxide
(d) Methane

Answer: (b) Hydrogen chloride

5. A pollutant released from the furnaces of power plants that causes soil pollution in surrounding area is

(a) Methane
(b) Fly ash
(c) Carbon monoxide
(d) Sodium chloride

Answer: (b) Fly ash

Short Answer Questions

1. Define pollution.

Answer: Pollution may be defined as the release of substances and energy (in excess of permissible limit) as waste products of human activities which result in changes, naturally harmful, within the natural environment.

2. What do you understand by a pollutant?

Answer: A pollutant can be defined as any form of energy or matter that causes degradation and pollution in the existing natural balance of ecosystems.

3. Give two examples each of solid, liquid and gaseous pollutants.

Answer:

• Solid pollutants: lead, mercury.
• Liquid pollutants: oil slicks, dissolved solids.
• Gaseous pollutants: chlorofluorocarbons, carbon dioxide.

4. What are the five types of pollution?

Answer: The five types of pollution are air pollution, water pollution, soil pollution, noise pollution, and radiation pollution.

5. What are the sources of air pollution?

Answer: The sources of air pollution are:

• Natural means: pollen grains, hydrocarbons released by vegetation, dust from deserts, storms, volcanic ash, and gases.
• Human activities: industrial activities, petroleum refineries, cement factories, thermal power stations, vehicles, pulp and paper industry, food processing units, and agricultural chemicals.

6. Give the full form of CPCB.

Answer: Central Pollution Control Board.

7. Name five important particulates that cause air pollution.

Answer: Five important particulates that cause air pollution are fluoride, cadmium, lead, mercury, and zinc.

8. What are the permissible limit of air pollution increases of RSPM and SPM?

Answer: The permissible limit for respirable suspended particulate matter (RSPM) is 60, and for suspended particulate matter (SPM) is 150.

9. Differentiate between Biodegradable and non-biodegradable pollutants.

Answer:

• Biodegradable pollutants: The pollutants which are capable of being broken down into simpler substances by the activity of microbes.
• Non-biodegradable pollutants: The pollutants which are not capable of being broken down into simpler substances by the action of microbes.

10. What are CFC’s? Give one example.

Answer: Chlorofluorocarbons (CFCs) are compounds that contain chlorine, fluorine, and carbon, and are responsible for ozone depletion. An example of a CFC is trichlorofluoromethane (trade name freon).

Long Answer Questions

1. What is the effect of various air pollutants at the global level?

Answer: At the gross level, air pollution causes two worldwide problems, namely contamination of the upper atmosphere and change of weather and climate.

Many modern environmental biologists feel that increasing particulate pollution may be reducing the amount of sunlight energy reaching the Earth’s surface, thereby, lowering solar radiation at the Earth’s surface, and producing a cooling effect on the world climate which could bring another ice age. Two of the most important consequences of air pollution at the global level are the greenhouse effect and ozone layer depletion.

The Central Pollution Control Board (CPCB) of the Government of India maintains the records of atmospheric pollution levels in many cities around the country. These data show that in many cities, air pollution reaches extremely dangerous levels on several days of the year.

The World Health Organisation has classified Delhi as one of the ten most polluted cities in the world.

2. What are the sources of water pollution?

Answer: Water pollutants are broadly divided into:

• Domestic wastes: These include waste materials from households, such as sewage and animal wastes. These wastes often contain disease-causing agents like bacteria, viruses, and parasitic worms, which can lead to water-borne diseases such as cholera, typhoid, and jaundice. Contamination of freshwater and shallow offshore seas by domestic sewage is common and poses serious health risks.
• Industrial wastes: Industries use water for various purposes like processing, cooling, and treatment of materials during production. The problem arises when the wastewater or effluents from industries are inadequately treated before being discharged into water bodies. These wastes often contain harmful chemicals, heavy metals, and other pollutants that make the water unfit for consumption and harmful to aquatic life. Major water-polluting industries include those involved in leather, pulp and paper, textiles, and chemicals.
• Agricultural wastes: The use of artificial and chemical fertilizers, pesticides, insecticides, and fungicides in agriculture leads to the contamination of soil and water. Runoff from agricultural fields carrying these chemicals is a significant source of water pollution. These chemicals can cause problems like eutrophication (excessive nutrient buildup in water bodies, leading to oxygen depletion) and bioaccumulation (the accumulation of toxic substances in the tissues of living organisms).
• Sediments: Sediments consist of soil, sand, and mineral particles that are washed into water bodies by storms and floods. These sediments can increase water turbidity, reduce sunlight penetration, and interfere with the aquatic ecosystem. They can erode pumping equipment and power turbines and reduce the amount of food available for fish. Poor soil conservation practices, deforestation, and floods contribute to the increased production of sediments in water bodies.
• Radioactive substances: Radioactive wastes come from uranium and thorium mining, refining, nuclear power plants, and industrial uses of radioactive materials. These substances can contaminate water supplies, making them hazardous to human health. Radioactive materials may enter the food chain through water and accumulate in the tissues of living organisms, leading to severe health issues. Radioactive waste dumping in oceans is particularly dangerous as it can lead to the contamination of marine life and coastal waters.

3. What is the main cause of industrial pollution?

Answer: The problem of industrial water pollution arises when inadequate measures are taken for effluent or wastewater treatment. Major water polluting industries in India include leather, pulp and paper, textiles, chemicals, etc. Methods of disposal of their wastes are primarily responsible for the risk to the environment and human health. Industries usually dump their wastes, either after treatment or without treatment, into both fresh and marine water bodies. The introduction of a wide variety of pollutants, both biodegradable and non-biodegradable, like oil, plastics, metallic, suspended solids, phenols, and various chemicals, derivatives of manufacturing processes, cannot be removed easily with available technology and this makes the freshwater unfit for consumption.

4. Write a short note on water pollution by sediments.

Answer: Sediments include soil, sand, and mineral particles which are washed into the aquatic environment by storms and flood waters. They also include large deposits of sewage, sludge, pulverized coal ash, and various industrial solids that go into the water body. The sediments erode the pumping equipment and power turbines and have the effect of increasing turbidity and consequently of reducing the amount of sunlight available to green plants which may lead to eventual asphyxiation of the fish. On the riverbeds, the sediments may interfere with the spawning sites and decrease the amount of food available for the fish.

As a result of intensive agriculture, poor soil conservation practices, deforestation, and floods, there has been an increased production of sediments and silts in streams and lakes.

5. Do you agree that nuclear waste dumping is the major cause of marine pollution?

Answer: Yes, nuclear waste dumping is a major cause of marine pollution. Radioactive substances are generated from wastes of uranium and thorium mining and refining from nuclear power plants and from industrial use of radioactive materials. The refining of uranium ore is an important source of radioactive waste producing radio nuclides of radium, bismuth, etc. Radium is the most significant waste product and is considered to be a hazard in drinking water. Water supplies must not contain radium more than the prescribed limit. Radioactive substances may cause objectionable radioactivity in marine organisms. Radioactive substances enter the human system with food and water. They accumulate in the blood, thyroid gland, liver, bone, and other muscular tissues.

At present, some low and medium-level wastes are sealed in containers and dumped into the oceans. If there is any damage to the container and it starts leaking, the nuclear waste could escape and enter the marine system. Consequently, they may be circulated by storms and ocean currents and eventually reach coastal waters with horrifying results to humans and other living organisms.

6. What are the major sources of soil pollution?

Answer: The major sources (or causes) of soil pollution can be categorised as:

• Domestic/commercial wastes: These include groceries, food scraps, food residues, vegetable remains, packing materials, cans, cardboard cartons, rags, paper, cinders, ash, broken gadgets, wood, worn-out furniture, metals, bones of dead animals, plastics, polythene bags, ceramics, glass, aluminium, rubber, leather, construction rubbish, bricks, sand, and other junks. Such wastes lying in the form of municipal wastes serve as dwelling places for disease-causing organisms. Another soil pollutant from domestic and commercial units, which carries with it the highest risk of spreading health hazards and epidemics, is human excreta.
• Modern agriculture: Modern agriculture is responsible for polluting the soil through the non-judicious use of chemical fertilisers, pesticides, insecticides, herbicides, fungicides, etc. Most of these chemicals are stable and remain in the soil for long periods without degradation. Therefore, they exhibit cumulative adverse effects. At present, around 600 different chemical compounds are being used for pest control which affect the land and subsequently, the human beings and other biota.
• Smelting and mining complexes: Smelting and mining complexes are another significant source of soil pollution. The areas around these complexes are usually found to be contaminated with heavy metals like cadmium, zinc, lead, copper, arsenic, and nickel. These metals occur in wastes resulting from smelting and mining operations. They are toxic to plants and may inhibit their growth. Their accumulation in plants makes the plants unsafe for human and animal consumption.
• Industrial wastes: The major sources of soil pollution are the industries such as paper and pulp mills, sugar mills, oil refineries, power and heating plants, chemicals and fertiliser manufacturing units, iron and steel plants, plastic and rubber-producing units, etc. These industries produce large amounts of solid wastes which are dumped on land, burnt, or emptied into rivers and seas. These solid wastes contain chemicals which affect the soil quality and life in it. Most industrial furnaces, especially power plants, produce fly ash which is the major cause of soil pollution in surrounding areas.

7. How is modern agriculture a source of soil pollution?

Answer: Modern agriculture is responsible for polluting the soil through the non-judicious use of chemical fertilisers, pesticides, insecticides, herbicides, fungicides, etc. Most of these chemicals are stable and remain in the soil for long periods without degradation. Therefore, they exhibit cumulative adverse effects. At present, around 600 different chemical compounds are being used for pest control which affect the land and subsequently, the human beings and other biota. To minimise the ill effects of pesticides, a number of countries have banned or restricted the use of many highly toxic agrochemicals. The WHO has called for an immediate ban on the use of endosulfan, a hazardous pesticide used for the rice crop. This pesticide has been found to be a cause of serious eye, kidney and liver disorders. The Government of India has already banned the use of 12 pesticides and imposed restrictions on many others to prevent environmental degradation.

8. Describe land degradation in the state of Nagaland.

Answer: Land degradation in Nagaland is a man-made as well as a natural phenomenon. Loss of vegetation due to deforestation, unsustainable fuel wood extraction, shifting cultivation (jhum), unplanned agricultural practices, encroachment into forest land for agriculture and settlements, forest fire, overgrazing, non-adoption of adequate soil conservation measures and improper crop rotation are some basic factors contributing to land degradation. The type of soil that are existing is erosion prone and the rainfall pattern is with high intensity. Thus, landslides are common. Another effect is sinking of land due to unstable geology. This has not only caused morphological changes in land, but also affected the socio-economic conditions of the people.

9. How do radioactive substances enter in the human system?

Answer: Radioactive substances enter the human system with food and water. They accumulate in the blood, thyroid gland, liver, bone and other muscular tissues. At present, some low and medium level wastes are sealed in containers and dumped into the oceans. If there is any damage to the container and it starts leaking, the nuclear waste could escape and enter the marine system. Consequently, they may be circulated by storms and ocean currents and eventually reach coastal waters with horrifying results to humans and other living organisms.

Think and Answer

Suppose you and your neighbours are being disturbed by the increasing number of generators in your locality. Apart from creating sound pollution, how does it affect your environment?

Answer: Apart from creating sound pollution, the increasing number of generators in a locality can have several negative effects on the environment:

• Air Pollution: Generators often run on diesel or petrol, emitting harmful gases like carbon monoxide, nitrogen oxides, and particulate matter into the atmosphere. This contributes to air pollution, which can have serious health effects, such as respiratory problems, and contributes to global issues like smog and climate change.
• Soil Contamination: Spills or leaks from fuel used in generators can lead to soil contamination. The chemicals in the fuel can seep into the ground, harming plant life and potentially entering the groundwater, affecting water quality.
• Water Pollution: If not managed properly, the oil and other chemicals from generators can be washed into nearby water bodies during rain, leading to water pollution. This can harm aquatic life and make the water unsafe for drinking and irrigation.
• Heat Emissions: Generators produce heat as they operate, which can contribute to localized warming, particularly in densely populated areas. This added heat can exacerbate the urban heat island effect, making the area warmer than surrounding rural areas.
• Carbon Footprint: The use of generators increases the carbon footprint of the area, as burning fossil fuels releases carbon dioxide, a major greenhouse gas that contributes to global warming and climate change.

Extras MCQs

1. What is the Latin word from which “pollution” is derived?

A. Polluere
B. Pollutio
C. Pollea
D. Pullo

Answer: A. Polluere

Q. What is the permissible limit for Respirable Suspended Particulate Matter (RSPM)?

A. 60
B. 100
C. 150
D. 200

Answer: A. 60

Q. What type of pollutants are released directly from the source in a harmful form?

A. Primary pollutants
B. Secondary pollutants
C. Tertiary pollutants
D. Quaternary pollutants

Answer: A. Primary pollutants

Q. What is the main source of lead in the air?

A. Leaded fuel in motor vehicles
B. Chemical plants
C. Coal burning
D. Cement factories

Answer: A. Leaded fuel in motor vehicles

Q. Which of the following is considered a natural source of air pollution?

A. Volcanic eruptions
B. Automobile exhaust
C. Industrial emissions
D. Cement dust

Answer: A. Volcanic eruptions

Q. What type of pollutants are described as those formed by chemical reactions in the environment?

A. Secondary pollutants
B. Primary pollutants
C. Solid pollutants
D. Gaseous pollutants

Answer: A. Secondary pollutants

Q. What is the concentration of Respirable Suspended Particulate Matter (RSPM) in Dimapur in 2014?

A. 156
B. 116
C. 104
D. 92

Answer: A. 156

Q. What is a major source of gaseous pollutants from human activities?

A. Petroleum refineries
B. Volcanic eruptions
C. Dust storms
D. Cement factories

Answer: A. Petroleum refineries

Q. What is the major source of carbon monoxide (CO) in the atmosphere?

A. Burning of coal
B. Incomplete burning of fossil fuels
C. Forest fires
D. Volcanic eruptions

Answer: B. Incomplete burning of fossil fuels

Q. Which harmful gas is formed by the incomplete combustion of fossil fuels and reduces the oxygen-carrying capacity of haemoglobin?

A. Carbon monoxide
B. Sulphur dioxide
C. Nitrogen dioxide
D. Methane

Answer: A. Carbon monoxide

Q. What is the primary factor causing an increase in carbon dioxide levels in the atmosphere?

A. Deforestation
B. Volcanic activity
C. Solar radiation
D. Agricultural runoff

Answer: A. Deforestation

Q. What is the main source of chlorofluorocarbons (CFCs) that contribute to ozone depletion?

A. Aerosol spray cans
B. Thermal power plants
C. Forest fires
D. Automobiles

Answer: A. Aerosol spray cans

Q. Which pollutant, when released by supersonic jet aircraft, can reduce ozone concentration by 30%?

A. Nitrogen oxide
B. Carbon dioxide
C. Sulphur dioxide
D. Chlorofluorocarbon

Answer: A. Nitrogen oxide

Q. What is the major man-made source of sulphur dioxide (SO2) pollution?

A. Thermal power plants
B. Automobile exhaust
C. Chemical plants
D. Paper mills

Answer: A. Thermal power plants

Q. What percentage of Delhi’s air pollution is contributed by vehicles?

A. 60%
B. 50%
C. 75%
D. 80%

Answer: A. 60%

Q. What substance in tobacco smoke is associated with increased risk of lung cancer?

A. Nicotine
B. Tar
C. Ammonia
D. Carbon monoxide

Answer: B. Tar

Q. What is the major cause of coral reef bleaching?

A. Rise in water temperature
B. Overfishing
C. Oil spills
D. Tourism activities

Answer: A. Rise in water temperature

Q. What are the major categories of water pollutants as mentioned in the text?

A. Domestic, Industrial, Agricultural, Sediments, Radioactive substances
B. Domestic, Chemical, Thermal, Sediments, Noise
C. Biological, Chemical, Thermal, Sediments, Noise
D. Domestic, Chemical, Noise, Sediments, Radioactive substances

Answer: A. Domestic, Industrial, Agricultural, Sediments, Radioactive substances

Q. Which type of waste is responsible for waterborne diseases like cholera and typhoid?

A. Domestic waste
B. Industrial waste
C. Agricultural waste
D. Sediments

Answer: A. Domestic waste

Q. Which heavy metal is associated with causing mental retardation due to poisoning?

A. Lead
B. Mercury
C. Cadmium
D. Arsenic

Answer: A. Lead

Q. What is the primary source of radioactive substances in water pollution?

A. Uranium and thorium mining
B. Industrial effluents
C. Agricultural runoff
D. Domestic sewage

Answer: A. Uranium and thorium mining

Q. Which pollutant cause bioaccumulation and biomagnification in water bodies?

A. Pesticides
B. Heavy metals
C. Plastics
D. Sediments

Answer: A. Pesticides

Q. What is a significant source of soil pollution in Nagaland?

A. Shifting cultivation (jhum)
B. Oil spills
C. Plastic waste
D. Nuclear waste

Answer: A. Shifting cultivation (jhum)

Q. What type of waste is primarily responsible for sediment pollution in water bodies?

A. Agricultural runoff
B. Industrial effluents
C. Domestic sewage
D. Soil erosion

Answer: D. Soil erosion

25. Which harmful effects are caused by pesticides and fertilizers?

A. Disruption of aquatic ecosystems
B. Reduction of air quality
C. Increase in noise pollution
D. Decrease in solar radiation

Answer: A. Disruption of aquatic ecosystems

Extra Questions and Answers

1. What is environmental pollution?

Answer: Environmental pollution is the lowering of environmental quality at local, regional, and global levels by natural and man-made processes.

Q. From which Latin word is “pollution” derived?

Answer: “Pollution” is derived from the Latin word “polluere.”

Q. What does “polluere” mean?

Answer: “Polluere” means to soil or defile.

Q. What are the types of pollution?

Answer: The types include air, soil, water, noise, and radiation pollution.

Q. What is a pollutant?

Answer: A pollutant is any form of energy or matter that causes degradation and pollution in the existing natural balance of ecosystems.

Q. What are primary pollutants?

Answer: Primary pollutants are pollutants released directly from the sources into the environment in a harmful form.

Q. What are secondary pollutants?

Answer: Secondary pollutants are pollutants modified to a harmful form in a medium or formed by chemical reactions.

Q. What are biodegradable pollutants?

Answer: Biodegradable pollutants can be broken down into simpler substances by the activity of microbes.

Q. What are non-biodegradable pollutants?

Answer: Non-biodegradable pollutants cannot be broken down into simpler substances by microbes and can harm all forms of life.

Q. Name one example of a solid pollutant.

Answer: Mining wastes are an example of solid pollutants.

Q. Name one example of a liquid pollutant.

Answer: Industrial effluents are an example of liquid pollutants.

Q. Name one example of a gaseous pollutant.

Answer: Sulphur dioxide is an example of a gaseous pollutant.

Q. What is carbon monoxide?

Answer: Carbon monoxide is an odourless, colourless gas produced by incomplete oxidation.

Q. What is the main human source of carbon monoxide in cities?

Answer: The main human source of carbon monoxide in cities is motor vehicles.

Q. What is ozone?

Answer: Ozone is a colourless, gaseous secondary pollutant formed by chemical reactions in the presence of sunlight.

Q. What is the major source of lead in the air?

Answer: The major source of lead in the air is leaded fuel used in motor vehicles.

Q. How is pollution defined?

Answer: Pollution is defined as the release of substances and energy (in excess of permissible limits) as waste products of human activities, resulting in naturally harmful changes within the natural environment.

Q. What are primary and secondary pollutants?

Answer: Primary pollutants are released directly into the environment in a harmful form, such as agricultural run-off containing pesticides in water. Secondary pollutants are modified to harmful forms in a medium or formed by chemical reactions, such as plastics and radioactive wastes.

Q. What are the types of pollutants based on biodegradability?

Answer: Pollutants are classified into biodegradable pollutants, which can be broken down into simpler substances by microbes, like paper and wood, and non-biodegradable pollutants, which cannot be broken down by microbes and can harm life, like plastic and lead.

Q. What are the types of solid pollutants mentioned in the document?

Answer: Solid pollutants include:

• Mining wastes: Metallic ores, earthen materials, rocks, and other wastes.
• Industrial wastes: Bagasse from sugar mills, pollutants from copper smelters, and aluminium industries.
• Agricultural waste: Excessive use of artificial or chemical fertilizers contaminating soil.

Q. How are liquid pollutants classified based on their sources?

Answer: Liquid pollutants are classified as:

• Industrial effluents: Chemical pollutants like chloride, sulphide, ammoniacal nitrogen, heavy metals, organic chemical compounds, and radioactive wastes.
• Agricultural run-off: Pesticides, insecticides, herbicides, and synthetic compounds.
• Urban pollutants: Ions from automobile washouts, fossil fuel combustion, and chemical fertilizers.
• Natural contaminants: Volcanic dusts, sediments from weathering and erosion, landslide debris, and decomposed organic matter.

Q. What are the sources of gaseous pollutants like sulphur dioxide and carbon monoxide?

Answer: Sulphur dioxide is released from processes like the decomposition of organic matter and volcanic eruptions, while carbon monoxide is primarily produced by motor vehicles in cities.

Q. How do human activities contribute to the release of sulphur dioxide and particulate matter?

Answer: Human activities, such as the smelting of mineral ores containing sulphur and the combustion of fossil fuels, are major contributors to the release of sulphur dioxide. Additionally, activities like mining, burning fossil fuels, and agricultural waste burning release particulate matter into the air, which can be either solid or liquid particles suspended in the atmosphere, reducing visibility and adversely affecting health.

Q. What role do motor vehicles play in urban pollution, according to the document?

Answer: In urban areas, motor vehicles are a significant source of various pollutants. They produce carbon monoxide through incomplete oxidation during combustion. They also contribute to air toxics, such as volatile organic compounds and lead from leaded fuel. The exhaust fumes and fuel vapours from vehicles further contribute to the overall degradation of air quality in cities.

Q. Describe the impact of particulate matter on human health and the environment.

Answer: Particulate matter consists of tiny solid or liquid particles that are suspended in the air. These particles, which can come from sources like smoke, dust, and plant spores, may reduce visibility and pose serious health risks. When inhaled, particulate matter can penetrate deep into the lungs, leading to respiratory problems and other health issues. The presence of particulate matter in the atmosphere also contributes to environmental degradation by interfering with photosynthesis in plants and contaminating water and soil.

Q. Discuss the classification of pollutants based on their state and provide examples of each type.

Answer: Pollutants can be classified based on their state—solid, liquid, and gaseous. 

Solid pollutants include:

• Mining wastes: Metallic ores and earthen materials dumped on land.
• Industrial wastes: Bagasse from sugar mills.
• Agricultural wastes: From the excessive use of artificial fertilizers. 

Liquid pollutants are divided by source:

• Industrial effluents: Contain chemicals like heavy metals.
• Agricultural run-off: Contains pesticides.
• Urban pollutants: Involve ions from fossil fuel combustion.
• Natural contaminants: Include volcanic dust and erosion debris. 

Gaseous pollutants are divided into primary and secondary categories:

• Primary pollutants: Include carbon monoxide from motor vehicles.
• Secondary pollutants: Include ozone formed by chemical reactions. Each type of pollutant significantly impacts the environment and human health, making pollution control a critical concern.

Q. What are pollutants?

Answer: Pollutants are substances that can pollute any component of the environment.

Q. How is pollution classified?

Answer: Pollution is classified as air, water, soil, noise, and radiation pollution.

Q. What is air pollution?

Answer: Air pollution is the presence of certain substances in the atmosphere that can produce undesirable effects on humans and the environment.

Q. Which type of pollution is common in industrial and metropolitan cities?

Answer: Air pollution is common in industrial and metropolitan cities.

Q. What did the Nagaland Pollution Control Board (NPCB) monitor in Kohima?

Answer: The NPCB monitored the respirable suspended particulate matter (RSPM) in Kohima.

Q. What was the RSPM concentration in Kohima in 2013?

Answer: The RSPM concentration in Kohima in 2013 was 104.

Q. What was the RSPM concentration in Dimapur in 2014?

Answer: The RSPM concentration in Dimapur in 2014 was 156.

Q. What is the permissible limit for suspended particulate matter (SPM)?

Answer: The permissible limit for SPM is 150.

Q. What natural pollutants does nature add to the environment?

Answer: Natural pollutants include pollen grains, hydrocarbons, dust, volcanic ash, gases, and smoke from forest fires.

Q. What can volcanic eruptions release?

Answer: Volcanic eruptions can release large amounts of gases and particulate matter.

Q. What is the major cause of air pollution?

Answer: Human activities are the major cause of air pollution.

Q. Which refinery is responsible for pollution-related decay of the Taj Mahal?

Answer: The Mathura-based petroleum refinery is responsible for pollution-related decay of the Taj Mahal.

Q. What do thermal power stations emit?

Answer: Thermal power stations emit fly ash, hydrocarbons, and other gases.

Q. What is a major source of carbon monoxide?

Answer: Incomplete burning of fossil fuels is a major source of carbon monoxide.

Q. Why is the content of CO₂ in the atmosphere increasing?

Answer: The CO₂ content is increasing due to burning fossil fuels and deforestation.

Q. What do chlorofluorocarbons (CFCs) cause?

Answer: CFCs cause ozone depletion.

Q. What intensifies the greenhouse effect?

Answer: Increased methane concentration in the stratosphere intensifies the greenhouse effect.

Q. What is the second most important contributor to air pollution after carbon monoxide?

Answer: Sulphur dioxide is the second most important contributor.

Q. What does sulphur dioxide produce in the atmosphere?

Answer: Sulphur dioxide produces sulphuric acid in the atmosphere.

Q. What are the main sources of nitrogen oxides?

Answer: The main sources are thermal power stations, factories, automobiles, and aircraft.

Q. What does nitrogen oxide reduce in the atmosphere?

Answer: Nitrogen oxide reduces the concentration of ozone.

Q. What is hydrogen chloride released from?

Answer: Hydrogen chloride is released from the combustion of coal, paper, plastics, and solid fuel.

Q. What does tobacco smoke contain?

Answer: Tobacco smoke contains about 300 chemical compounds, including nicotine and tar.

Q. What are the health effects of smoking?

Answer: Smoking can cause cancer, increase blood pressure, and is harmful to pregnant women.

Q. How is pollution classified based on the environment and kind of pollutant?

Answer: Pollution is classified based on the environment and the kind of pollutant into five categories: air pollution, water pollution, soil pollution, noise pollution, and radiation pollution. Each type of pollution affects different components of the environment and has distinct sources and consequences.

Q. What did the Nagaland Pollution Control Board’s air quality monitoring reveal about RSPM levels in Kohima and Dimapur?

Answer: The Nagaland Pollution Control Board’s air quality monitoring revealed that the levels of respirable suspended particulate matter (RSPM) in Kohima and Dimapur were significantly higher than the permissible limit of 60. In Kohima, RSPM levels were 104 in 2013, while in Dimapur, they reached 156 in 2014, indicating severe air pollution in both districts.

Q. What natural sources contribute to air pollution, and what are their effects?

Answer: Natural sources contributing to air pollution include pollen grains, hydrocarbons from vegetation, dust from deserts and storms, and volcanic ash and gases. These pollutants can cause various environmental effects, such as volcanic ash killing vegetation by preventing photosynthesis and transpiration and dust storms reducing visibility.

Q. How do human activities contribute to air pollution, and what are some examples?

Answer: Human activities contribute significantly to air pollution through industrial operations, vehicle emissions, and the burning of fossil fuels. For example, steel and chemical plants, petroleum refineries, and thermal power stations release pollutants like carbon monoxide, sulphur dioxide, and nitrogen oxides, which are harmful to humans, plants, and the environment.

Q. What are the health risks associated with carbon monoxide and carbon dioxide emissions?

Answer: Carbon monoxide, produced by incomplete burning of fossil fuels, reduces the oxygen-carrying capacity of blood by forming carboxyhaemoglobin, leading to potential suffocation. Carbon dioxide emissions, increased by burning fossil fuels and deforestation, contribute to global warming and climate change, posing long-term risks to the planet.

Q. What is the role of chlorofluorocarbons (CFCs) in ozone depletion, and what are the sources of CFCs?

Answer: Chlorofluorocarbons (CFCs) play a major role in ozone depletion by accumulating in the stratosphere and breaking down ozone molecules. Sources of CFCs include aerosol spray cans, air conditioners, refrigerators, foam plastics, and fire extinguishers. Their long-lasting presence in the atmosphere makes them a significant environmental threat.

Q. How does sulphur dioxide contribute to air pollution, and what are its sources?

Answer: Sulphur dioxide is a major contributor to air pollution, produced mainly by thermal power plants, crude oil refineries, and automobiles. It reacts with atmospheric oxygen and water to form sulphuric acid, which is highly corrosive and harmful to both living organisms and the environment.

Q. What are the harmful effects of tobacco smoke, and why is it considered a pollutant?

Answer: Tobacco smoke, containing around 300 chemical compounds like nicotine and tar, is considered a pollutant due to its health risks. It causes lung cancer, heart disease, and other respiratory issues. Smoking is especially dangerous in closed spaces and can also harm pregnant women by increasing the risk of miscarriage.

Q. How does air pollution impact metropolitan cities, and what does the data from Nagaland suggest?

Answer: Air pollution significantly impacts metropolitan cities by deteriorating air quality and posing health risks to residents. Data from Nagaland indicates that the concentrations of respirable suspended particulate matter (RSPM) in Kohima and Dimapur have been consistently above the permissible limits, with levels reaching 104 in Kohima and 156 in Dimapur in recent years. This suggests that air pollution is a growing concern in these cities, particularly during the winter months when pollution levels are highest. The data highlights the need for effective air quality management and pollution control measures to protect public health and the environment in urban areas.

Q. What are the natural and human-made sources of air pollution, and how do they differ in their impact?

Answer: Natural sources of air pollution include pollen grains, dust from deserts, volcanic ash, and smoke from forest fires. These pollutants are typically dispersed widely and can cause temporary environmental changes, such as reduced visibility during dust storms or cooling effects from volcanic ash in the atmosphere. Human-made sources of air pollution, however, have a more sustained and severe impact. Industrial activities, vehicle emissions, and the burning of fossil fuels release harmful pollutants like carbon monoxide, sulphur dioxide, and nitrogen oxides, leading to chronic health issues, environmental degradation, and climate change. The impact of human-made pollutants is more pervasive and long-lasting, contributing significantly to global pollution levels.

Q. How do carbon monoxide and carbon dioxide emissions from human activities affect the environment and human health?

Answer: Carbon monoxide (CO) and carbon dioxide (CO₂) emissions from human activities have significant adverse effects on both the environment and human health. Carbon monoxide, produced by the incomplete combustion of fossil fuels, can lead to serious health issues when inhaled, as it binds with haemoglobin in the blood, reducing its ability to carry oxygen. This can cause suffocation and, in severe cases, death. On the other hand, carbon dioxide emissions, primarily from the burning of fossil fuels and deforestation, contribute to the greenhouse effect, leading to global warming and climate change. This rise in global temperatures affects ecosystems, weather patterns, and sea levels, posing long-term risks to all forms of life on Earth.

Q. What are chlorofluorocarbons (CFCs), and why are they a major concern for the ozone layer?

Answer: Chlorofluorocarbons (CFCs) are synthetic compounds used in aerosol sprays, air conditioners, refrigerators, and other products. They are a major concern for the ozone layer because, once released into the atmosphere, they gradually accumulate in the stratosphere, where they break down ozone molecules. This depletion of the ozone layer increases the amount of harmful ultraviolet (UV) radiation reaching the Earth’s surface, which can lead to increased skin cancers, cataracts, and other health issues, as well as negative impacts on ecosystems. The long lifespan of CFCs in the atmosphere makes them a persistent environmental threat, necessitating global efforts to reduce their production and use.

Q. Discuss the various sources of air pollution and their specific impacts on the environment and human health.

Answer: Air pollution arises from a variety of natural and human-made sources, each contributing uniquely to environmental degradation and public health concerns. Natural sources include pollen grains, volcanic ash, dust from deserts, and smoke from forest fires. These pollutants, while impactful, are generally temporary and localized, with effects such as reduced photosynthesis due to volcanic ash or vision impairment during dust storms. However, the more significant and lasting sources of air pollution are anthropogenic, primarily from industrial activities, vehicle emissions, and the burning of fossil fuels. Industrial operations, such as steel and chemical plants, refineries, and power stations, emit large quantities of harmful gases like sulphur dioxide, nitrogen oxides, and carbon monoxide. These pollutants can cause respiratory issues, cardiovascular diseases, and other serious health problems in humans. Additionally, the greenhouse gases produced by these activities, including carbon dioxide and methane, contribute to global warming, leading to climate change, rising sea levels, and extreme weather events. Moreover, the emission of chlorofluorocarbons (CFCs) from aerosol sprays and refrigerants has led to significant depletion of the ozone layer, increasing the risk of skin cancers and other UV-related health issues. The compounded effects of these pollutants highlight the urgent need for stringent air quality regulations and the adoption of cleaner technologies to mitigate the impacts of air pollution on both the environment and human health.

Q. Analyze the consequences of increased carbon dioxide levels in the atmosphere, focusing on the factors contributing to this rise and its broader implications.

Answer: The increase in carbon dioxide (CO₂) levels in the atmosphere is a critical environmental issue, driven primarily by human activities such as the burning of fossil fuels and deforestation. The combustion of coal, oil, and natural gas for energy production and transportation releases vast amounts of CO₂ into the atmosphere, while deforestation reduces the planet’s ability to absorb this excess CO₂, exacerbating the problem. The elevated levels of CO₂ contribute significantly to the greenhouse effect, wherein trapped heat leads to global warming and subsequent climate change. The broader implications of rising CO₂ levels include melting polar ice caps, rising sea levels, and more frequent and severe weather events such as hurricanes, droughts, and floods. These changes disrupt ecosystems, leading to loss of biodiversity and altered habitats, and pose significant challenges to agriculture, water resources, and human settlements. Moreover, the increasing CO₂ concentration in the atmosphere acidifies the oceans, harming marine life and ecosystems. The far-reaching consequences of heightened CO₂ levels underscore the necessity for global efforts to reduce emissions, enhance carbon sequestration through reforestation, and transition to renewable energy sources to mitigate the adverse effects on the environment and human society.

Q. Evaluate the role of chlorofluorocarbons (CFCs) in environmental pollution, particularly focusing on their impact on the ozone layer and the measures taken to address this issue.

Answer: Chlorofluorocarbons (CFCs) have played a significant role in environmental pollution, particularly due to their impact on the ozone layer. CFCs are synthetic compounds used in various applications, including aerosol sprays, refrigeration, and air conditioning. Once released into the atmosphere, CFCs migrate to the stratosphere, where they are broken down by ultraviolet (UV) radiation, releasing chlorine atoms. These chlorine atoms then catalyze the destruction of ozone (O₃) molecules, leading to the thinning of the ozone layer, which acts as Earth’s protective shield against harmful UV radiation. The depletion of the ozone layer allows more UV radiation to reach the Earth’s surface, increasing the incidence of skin cancers, cataracts, and other health issues in humans, as well as causing damage to ecosystems, particularly affecting phytoplankton, the foundation of the aquatic food chain. Recognizing the severe implications of ozone depletion, the international community adopted the Montreal Protocol in 1987, a landmark agreement aimed at phasing out the production and use of CFCs and other ozone-depleting substances. The successful implementation of this protocol has led to significant reductions in CFC emissions and has been instrumental in the gradual recovery of the ozone layer. However, continued vigilance and adherence to the protocol’s provisions are necessary to ensure the complete restoration of the ozone layer and to mitigate the long-term environmental impact of CFCs.

Q. What are the two worldwide problems caused by air pollution?

Answer: Contamination of the upper atmosphere and change of weather and climate.

Q. What effect does particulate pollution have on sunlight energy?

Answer: It reduces the amount of sunlight energy reaching the Earth’s surface.

Q. What global phenomena are consequences of air pollution?

Answer: The greenhouse effect and ozone layer depletion.

Q. Which organisation maintains records of atmospheric pollution levels in India?

Answer: The Central Pollution Control Board (CPCB).

Q. Which city has been classified as one of the ten most polluted cities in the world by the World Health Organisation?

Answer: Delhi.

Q. How is water pollution defined?

Answer: The introduction of substances into a water body that alter its natural quality and impair its usefulness.

Q. What is the main source of water pollution in Nagaland?

Answer: Untreated industrial effluents and wastewater.

Q. What type of pollution affects both surface and groundwater?

Answer: Water pollution.

Q. What are the major causes of marine pollution?

Answer: Oil spills, nuclear waste dumping, tourism industry, and transporting oil.

Q. What substances contribute to groundwater pollution?

Answer: Chemicals, metals, and pollutants dissolved in water.

Q. What is soil pollution?

Answer: Physical or chemical changes in the soil rendering it incapable of beneficial use.

Q. What are the primary sources of soil pollution?

Answer: Domestic/commercial wastes, modern agriculture, smelting and mining complexes, and industrial wastes.

Q. How does modern agriculture contribute to soil pollution?

Answer: Through the non-judicious use of chemical fertilisers, pesticides, and insecticides.

Q. What is a significant source of soil pollution from industrial activities?

Answer: The production of solid wastes containing chemicals that degrade soil quality.

Q. What is the main consequence of smelting and mining on soil?

Answer: Contamination with heavy metals like cadmium, zinc, and lead.

Q. What happens when sediments increase turbidity in water?

Answer: They reduce sunlight available to green plants, leading to asphyxiation of fish.

Q. What are radioactive substances in water a result of?

Answer: Wastes from uranium and thorium mining and nuclear power plants.

Q. What are the consequences of radioactive substances in the human body?

Answer: Accumulation in blood, thyroid gland, liver, bone, and other tissues.

Q. What kind of pollution is caused by domestic sewage?

Answer: Water pollution.

Q. What are the health risks associated with untreated sewage in water?

Answer: Diseases like cholera, gastroenteritis, typhoid, and jaundice.

Q. What are the global consequences of air pollution, and why are they significant?

Answer: The global consequences of air pollution include the greenhouse effect and ozone layer depletion. These phenomena are significant because they contribute to climate change and increased UV radiation, which have far-reaching effects on the environment and human health.

Q. How does water pollution impact public health in Nagaland, and what are the main sources?

Answer: Water pollution in Nagaland poses a significant threat to public health due to contamination from untreated industrial effluents, chemical runoff from agriculture, and lack of sewage treatment facilities. These pollutants render water bodies toxic and unsuitable for consumption, leading to health hazards.

Q. What are the primary sources of marine pollution, and how do they affect marine ecosystems?

Answer: Primary sources of marine pollution include oil spills, nuclear waste dumping, tourism activities, and transportation of oil. These pollutants cause severe damage to marine ecosystems by contaminating water, affecting coral reefs, and endangering marine life.

Q. How do agricultural practices contribute to water and soil pollution?

Answer: Agricultural practices contribute to pollution through the extensive use of chemical fertilisers, pesticides, and insecticides. These chemicals runoff into water bodies, leading to eutrophication and bioaccumulation, and they degrade soil quality by disrupting nitrogen fixation and killing beneficial organisms.

Q. What are the long-term effects of heavy metals from industrial pollution on the environment and human health?

Answer: Heavy metals like lead, mercury, and arsenic, introduced through industrial pollution, have long-term effects on the environment by contaminating soil and water. In humans, these metals accumulate in the body, causing severe health issues like mental retardation, neurological damage, and various diseases.

Q. Why is soil pollution from industrial activities particularly harmful, and what are its consequences?

Answer: Soil pollution from industrial activities is particularly harmful because it involves the introduction of non-biodegradable chemicals that persist in the environment. These pollutants degrade soil quality, harm plant life, and pose risks to human health by entering the food chain through contaminated crops.

Q. What role does the Central Pollution Control Board (CPCB) play in monitoring air pollution, and what have been its findings?

Answer: The Central Pollution Control Board (CPCB) of the Government of India is responsible for maintaining records of atmospheric pollution levels across various cities in the country. Its findings reveal that air pollution in many cities often reaches extremely dangerous levels, posing significant health risks to the population. The CPCB’s monitoring efforts are crucial in identifying pollution trends and implementing measures to control and reduce air pollution across India.

Q. How does groundwater pollution occur, and what are its implications for human health?

Answer: Groundwater pollution occurs when harmful materials such as chemicals and metals from solid wastes dissolve or leach into the water and percolate down into the soil, contaminating groundwater. This is a serious problem because groundwater is a primary source of drinking water. Contaminated groundwater poses severe health risks, as pollutants can cause diseases and disrupt the natural balance of ecosystems. Long-term exposure to contaminated water can lead to chronic health issues in humans, including neurological and physiological disorders.

94. Discuss the impact of domestic and commercial wastes on soil pollution and public health.

Answer: Domestic and commercial wastes significantly contribute to soil pollution by introducing a wide variety of pollutants, including biodegradable and non-biodegradable materials. These wastes, when not properly managed, serve as breeding grounds for disease-causing organisms, leading to the spread of health hazards and epidemics. The increasing quantity and changing composition of these wastes, with a rise in non-biodegradable materials like plastics and metals, exacerbate the problem. The contamination of soil with these materials not only affects the environment but also poses risks to public health through the contamination of air, water, and food supplies.