WBBSE Solutions For Class 7 Geography Chapter 8 Soil Pollution

WBBSE Chapter 8 Soil Pollution Long Question And Answers

Question 1. Discuss the sources or causes of soil pollution.
Answer:

Sources or causes of soil pollution:

Soil can become polluted because of natural as well as man-made reasons. Natural causes of soil pollution are heavy rainfall, landslide, strong wind movement, etc. But soil pollution is mainly caused due to indiscriminate activities of men.

The main sources of soil pollution are as follows-

1. Urbanisation:

The constant rise in population has increased the demand for dwelling places. So forests are being cleared to provide more land for dwelling and agriculture. As a result, the soil is getting eroded as well as polluted.

2. Agriculture:

• The demand for food increases with the rise in population. So, the use of chemical fertilizers and pesticides also increases to produce more crops on the same plot of land.
• This leads to the death of several creatures like earthworms and other insects which live in the soil. This, in turn, lowers the fertility of soil and causes soil pollution.

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3. Industrial pollution:

• Every year, about 16000 kg of hard disposable industrial wastes accumulate on the ground.
• Every year about 2×109 kg of fly ash is ejected from leather, dye, plastic and paper industries; oil refineries; metal extraction plants and thermal power plants and this lowers the soil fertility.
• Also, the smoke and poisonous gases (SO₂, NO₂) coming out from factories cause acid rain which contaminates the soil.

• Domestic wastes: Bacteria, virus,es and other microbes breed on the garbage heaps disposed from houses, hospitals, markets, towns, and cities. The poisonous chemicals in these heaps pollute the Earth.
• Atomic pollution: A vital cause of soil pollution is the existence of atomic power stations, atomic research centers, hospitals, and nursing homes using radioactive materials and radioactive wastes.
• Medical wastes: An important cause of soil pollution is the disposal of medical waste without proper segregation from various hospitals and medical centers.
• Transport: Vehicles usually emit smoke containing CO₂, SO_2, etc. which mixes with rainwater and falls on the ground as acid rain. This rainwater mixes with soil and causes soil pollution.

Question 2. Describe the methods used to control soil pollution.
Answer:

Methods used to control soil pollution:

The methods used to control soil pollution are-

• Increased use of organic fertilizer: Increase in the use of organic fertilizers instead of chemical fertilizers so that the soil health remains unaffected.
• Less use of plastic: Wherever plastic is discarded as a waste product it clogs soil pores. It causes soil pollution. Thus the use of plastic products should be lessened. We can use paper and jute bags instead of plastic.
• Specific ground for waste disposal: Wastes should be disposed off in specific dumping grounds or vats and not thrown here and there.
• Proper method of waste disposal: The proper method should be undertaken for disposal of solid hazardous wastes to prevent deterioration of soil health and the environment being affected at any and every place.
• Recycle: Recycling of soil pollutants should be encouraged to lessen their harmful impacts.
•  Implementation of strict laws: Strict laws should be implemented for waste disposal to control soil pollution.
• Soil testing: Regular soil tests should be done as a method to control soil pollution.
• Increase awareness: The people should be made aware about the ways to prevent soil pollution.

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Question 3. Write a note on the effects of soil pollution on human life.
Answer:

Effects of soil pollution on human life:

Soil pollution brings about the following effects on human life-

1. Polluted soil is the breeding ground of various microbes that cause diseases in the human body such as cholera, amoebiasis, typhoid, and paratyphoid.
2. Inorganic pollutants like mercury cause a variety of diseases like mental illness, loss of eyesight, etc.
3. Due to the effect of cadmium, different diseases occur in the human body like increased blood pressure.
4. Under the effect of lead, different diseases are observed in the human body like anemia.
5. DDT and other slowly degradable chemical substances which enter our food chain, pass from lower to higher nutrient levels. It accumulates within the organisms. This is called biomagnification.
6. Under the effect of soil pollution, soil fertility decreases, which in turn lowers the productivity of the land thereby decreasing the income of the farmers.
7. When the pesticide and fertiliser-contained soil drains into the nearby waterbodies it renders the water of the waterbody unfit for further human use.

Question 4. Observe soil pollution in your locality and write it down.

1. Name of locality or village………….
2. Is the garbage of your house disposed off at a certain place?
3. Is that waste cleaned every day?
4. Do you find any difference in colour of the soil around the factories and that near your house?
5. Make a list of the causes of soil pollution in your area.

Answer:

Name of the student: Sk Arman Class: VII

School: Guptipara High School.

Question 5. How do household and municipal solid wastes cause soil pollution?
Answer:

Household and municipal solid wastes cause soil pollution:

• Solid wastes of households example, broken pieces of plastic, torn packets, paper, clothes, batteries, broken glass, food and kitchen wastes like vegetable peel, and fruit peel, and municipal wastes like excreta, and medical wastes are collected by the municipality within an area.
• These waste materials are segregated and then sent for reprocessing. Most of the domestic wastes are directly transported to landfill sites for disposal without proper segregation into organic, reusable, and recyclable wastes.
• This is one of the main causes of soil pollution.

Example-The Dhapa dumping ground just outside Kolkata has become polluted. As a result, fruits and vegetables grown in polluted soil transmit a variety of diseases in humans.

These diseases have maximum manifestation at the producer level and this is called ‘biomagnification’.

Question 6. How do plastics aggravate the problem of soil pollution?
Answer:

Plastics aggravate the problem of soil pollution:

At present different types of plastic are used in various parts of the world. These can be biodegradable as well as non-biodegradable. Wherever plastic is discarded as a waste product, it clogs soil pores, drains, pipes, and ditches.

The various ways in which plastic causes soil pollution are-

1. Clogging of soil pores by plastic wastes and wrappers results in the loss of soil fertility making the farmland unsuitable for cultivation.
2. Plastic wastes accumulating on the wetlands make them overflow with water.
3. The plastic-forming compounds kill different microorganisms present in the soil and harm man and other living beings.

Question 7. Explain how soil pollution is caused due to use of pesticides.
Answer:

Excessive use of pesticides causes soil pollution in farmlands in the following ways-

1. Pesticides and herbicides are a type of poison which are not decomposed by bacteria. As a result, they accumulate in the soil causing soil pollution.
2. The poisonous chemicals present in pesticides mix with the soil when sprayed on agricultural fields. The agricultural runoff flows into the waterbodies, causing further water pollution.
3. Excessive use of pesticides also kills other soil organisms.
4. The harmful effects of pesticides are also observed in human beings. Human beings ingest these toxic elements through the consumption of contaminated vegetables. Accumulation of these poisonous components in the body weakens the nervous system. As a result, lung diseases and stomach infections are common. It can even lead to cancer.

Question 8. How does inorganic manure cause soil pollution?
Answer:

Inorganic manure cause soil pollution:

if the inorganic manure or fertilizers are used in greater quantity it brings about soil pollution in the following ways-

1. If inorganic manure or fertilizers containing nitrogen is used excessively in agricultural grounds, it gets converted to poisonous nitrogen dioxide in the presence of sunlight, which in turn causes soil pollution.
2. Though this chemical increases soil productivity in the short run, in the long run, this chemical clogs the soil pores lowering the aeration and water-holding capacity of the soil.
3. Thus soil productivity decreases in the long run.
4. Excessive use of phosphates to increase soil productivity also causes soil pollution as high levels of phosphate dissolved in the soil harm plant growth.

Question 9. What are the different types of soil pollutants?
Answer:

Different types of soil pollutants:

The substances which bring about soil pollution are called soil pollutants. The different types of pollutants and their origin are listed below-

Question 10. Fill up the knowledge hive with information about the Chernobyl disaster.

Answers:

1. A nuclear reactor exploded at Chernobyl in Ukraine at 1.30 am on 26 April 1986.
2. In this explosion radioactive materials. scattered over a region of about 3000 sq km.
3. In this explosion 31 persons had died and more than a million were severely affected.
4. The land on the periphery of the explosion zone became unsuitable for agriculture.
5. Farm animals as well as human beings gave birth to deformed progeny due to the effect of radioactivity.

Question 11.

 

Down:

1. Soil pollutant
3. A ferroalloy

Across:

2. A vegetation cover that controls soil erosion and promotes soil fertility
4. Chemical sprayed on farmlands to kill pests.
5. The gas which leaked in the Bhopal Disaster

Answers:

Down: 1. PLASTIC, 3. ARSENIC
Across: 2. GRASSLAND 4. PESTICIDE 5. MIC

Question 12.

 

Down:

1. An inorganic pollutant.
2. Organic matter whose presence turns the color of the soil black
3. A gas emitted through the decomposition of soil organisms.

Across:

4. A heavy metal
5. A chemical fertilizer

Answers:

Down: 1. PHOSPHATE, 2. HUMUS, 3. METHANE
Across: 4. CADMIUM, 5. UREA

WBBSE Chapter 8 Soil Pollution Short Question And Answers

Question 1. How does industrialization cause soil pollution?
Answer:

Industrialization cause soil pollution:

• Industrial centers are the major sources of chemicals that cause soil pollution. The wastewater that is discharged from various industrial activities contains a lot of chemicals, radioactive materials, metallic wastes, and many other insoluble materials.
• Besides, different gaseous and non-gaseous wastes are let out from factories and mixed with the soil causing soil pollution.

For example- Fly ash from thermal power stations mixes with the soil reducing its fertility.

Question 2. Describe how inorganic wastes cause soil pollution.
Answer:

Inorganic wastes cause soil pollution:

• Poisonous metals generated from different metal-based industries example, lead, copper, mercury, nickel, cadmium, and waste products from towns and cities example, plastic, gas, storage battery, and chemical fertilizers usually accumulate in the soil.
• The organisms present in the soil absorb these toxic compounds and degenerate the soil quality. This is known as pollution by inorganic wastes.

Question 3. How does urbanization cause soil pollution?
Answer:

Urbanization cause soil pollution:

High rate of population growth has increased the pace of urbanization.

• It has resulted in an increase in the requirement of land for dwelling, agricultural activities, industrial activities, construction areas, etc.
• These have led to an increase in the following factors-construction of brick kilns, landfill, and illegal dumping, throwing of domestic garbage anywhere, improper disposal of municipal and industrial wastes.
• As a result of these soil is getting eroded as well as polluted.

Question 4. How do agricultural activities cause soil pollution?

Agricultural activitAnswer:ies cause soil pollution in the following ways-

•  Use of pesticides: To increase the productivity of crops, spraying of pesticides is very common. This kills the beneficial microorganisms and other organisms present in the soil. As a result, the soil loses its productivity.
• Use of chemical fertilizers: To increase agricultural productivity, chemical fertilizers are sprayed on fields. This alters the organic composition of the soil, increasing its salt content. As a result, the soil becomes unproductive.
• Excessive ploughing: Excessive ploughing on agricultural fields erodes the top layer of the soil, resulting in the removal of the nutrients contained in it

Question 5. Write a short note on the effects of soil pollution.
Answer:

The effects of soil pollution are-

1. Loss of fertility and productivity of the soil.
2. Changes in the physical and chemical characteristics of the soil.
3. Lowering of the protein content of various crops.
4. Affected plant growth and animal health.
5. Affected crop cultivation and human health.
6. Groundwater pollution.
7. Imbalance in the natural ecosystem.

Question 6. What is the impact of acid rain on the soil?
Answer:

Impact of acid rain on the soil:

Acid rain falling on the Earth’s surface adversely affects the soil. The major effects of acid rainwater mixed with the soil are as follows:

1. The soil becomes acidic.
2. The flora cannot perform photosynthesis, leading to the growth of distorted branches and stems.
3. This affects the normal growth and development of plants.
4. The soil loses its fertility making it unsuitable for cultivation.
5. Death of the microorganisms that are present in the soil is one of the harmful impacts of acid rain.

Question 7. Write a brief note on Bhopal Gas Tragedy.
Answer:

Bhopal Gas Tragedy:

• The Bhopal Gas Tragedy was a toxic gas leak incident in India that occurred on the night of 2-3 December 1984 from the pesticide plant of Union Carbide India Limited in Bhopal, Madhya Pradesh.
• The local people were exposed to about 36 tonnes of toxic methyl isocyanate or MIC gas and other chemicals. This gas affects the human lungs and burns the cornea of the eyes.
• The Bhopal Disaster brought about the death of around 10,000 people (unofficial count) approximately and disabled or injured another 2 lakh people.

Question 8. Write a short note on Chornobyl Disaster.
Answer:

Chornobyl Disaster:

• The Chornobyl Disaster was a catastrophic nuclear accident that occurred on 26 April 1986 at the Chornobyl Nuclear Power Plant in Ukraine.
• An explosion and fire released a large quantity of radioactive particles into the atmosphere, which spread over a wide area. About 1 lakh 35 thousand people were evacuated as a result of this disaster.
• According to scientists, the impact of this disaster will be felt for another 100 years.

Question 9. What are the things one should do to avoid soil pollution in villages?
Answer:

‘Things to do’ in villages to avoid soil pollution are as follows-

1. Farmers should be explained why excessive use of chemical fertilizers in farmlands is not advisable and their harmful effects on human health.
2. The farmers should be made aware about the advantages of organic farming.
3. The farmers should be told about the negative effects of pesticides.
4. The farmers should be explained the advantages of controlled growth of organisms in comparison to the use of pesticides.
5. Farmers should be made aware about the high water retention capacity. This soil is ideal negative effects of mono-cropping.
6. Information and advice should be given to the farmers about the general improvement of their farm produce.
7. The people should be made aware of the inter-relationship between the environment and farming.

Question 10. What is the importance of soil?
Answer:

Importance of soil:

The importance of soil is limitless. A few of them are as follows-

1. Soil provides water, minerals, and nutrients which help organisms to survive.
2. Plants grow in soil.
3. The soil acts as the safest habitat for bacteria, fungi, algae, rats, worms, etc.
4. A variety of crops grow in a variety of soil. For example, cotton grows in black regur soil, wheat grows in chernozem soil.
5. The brick kilns and clay industry are highly dependent on soil.

Question 11. Huge amounts of paddy, jute, and vegetables are grown in the silt soil on the banks of the Ganga. But less amount of crops grows in the coarse soil of Purulia. Why?
Answer:

The alluvial soil formed by silt deposited by River Ganga is fine-grained, fertile, and has for crop cultivation because the movement of air within the soil particles is good.

• On the other hand, the soil in Purulia is coarse, infertile, and full of pebbles.
• It contains very less organic matter and has a low water-retention capacity.
• Therefore, crops do not grow in abundance in the soil of Purulia.

Question 12. Beautiful flowers bloom every day in the plants of your flower pots or garden. What may happen to the plant if filthy oil is poured into the pot?
Answer:

Beautiful flowers bloom every day in the plants of your flower pots or garden.

If filthy oil is poured into the flowerpots, it will degrade the soil quality. The plant will not be able to obtain the necessary nutrients from the soil and after a few days it will die, because-

1. Plant roots will not be able to take in water from the soil.
2. The level of nutrients present in the soil will decrease.
3. The movement of air within the soil will decrease.

Question 13. What do you mean by soil pollution?
Answer:

Soil pollution:

• Any process that degrades the quality of soil and reduces its productivity and utility is called soil pollution.
• Harmful chemicals from agricultural run-offs due to overuse of chemical fertilizers and pesticides, weedicides, plastic, domestic wastes, industrial wastes, biodegradable and non-biodegradable substances, and radioactive waste products mix with the soil.
• Thereby altering its properties or characteristics and nutrient content.

Question 14. How do the microorganisms cause soil pollution?
Answer:

Microorganisms cause soil pollution:

• Waste products of households, markets, and hospitals are usually not disposed of properly.
• This garbage acts as the breeding ground of different viruses and bacteria which affect the soil quality and the organisms present in it. The soil becomes unproductive.

Question 15. Write how radioactive pollutants cause soil pollution.
Answer:

Radioactive pollutants cause soil pollution:

• Radiation from nuclear reactors, medical imaging, and scientific research processes emit radioactive substances or particles.
• These emitted particles mix with the soil causing soil pollution. The main radioactive pollutants are- Carbon 13, Uranium-235, Radium-226, etc.

Question 16. How is soil pollution caused by soil erosion?
Answer:

Soil pollution caused by soil erosion:

• Removal of the fertile topmost layer of the soil which contains organic matter or humus due to the action of natural agents like rain, running water, wind, and glacier is called soil erosion.
• As the uppermost layer is removed the soil loses its fertility and becomes unsuitable for plant growth. Thus, soil erosion is a natural factor causing soil pollution.
• Among the pesticides used in agricultural fields, the chemicals which cause maximum soil pollution are Dichloro Diphenyl Trichloroethane (DDT), Benzene Hexachloride (BHC), Pyrethrin, Malathion, and compounds containing carbonate.
• The main chemical fertilizers causing soil pollution are urea, phosphate, and sulfate compounds.

Question 17. What are the diseases caused in humans as a result of soil pollution?
Answer:

Many diseases and their symptoms are observed in humans as a result of soil pollution.

These are as follows-

Question 18. Name the type of diseases which occur in human bodies due to the use of pesticides.
Answer:

• Pesticides enter the human body through the consumption of fruits and vegetables.
• The high amount of accumulated pesticides in the human body weakens the nervous system resulting in lung diseases and stomach infections and may often lead to cancer.

Question 19. What are the causes of the increase in the level of acidity of the soil?
Answer:

The causes of the increase in the acidity level of soil are as follows-

• In forest areas, the dead leaves fall on the forest floor, get decomposed, and form humus. This humus releases humic acid which increases the acidity of the soil.
• Presently eucalyptus trees have been planted in various forest areas to curb the effect of deforestation. The acidity level of the eucalyptus leaves is high. The leaves that fall on the forest floor mix with the soil turning it acidic.
• Nowadays, nitrogen-based fertilizers are used in abundance on the farmlands. This increases the acidity of the soil.
• Toxic wastes discharged from various industries are highly acidic in nature. These mix with the soil turning it acidic.

Question 20. How does the organic matter present in the soil cause soil pollution?
Answer:

The organic matter present in the soil cause soil pollution:

• When inorganic pesticides, like DDT and Chlorodon mix with the soil, the organisms present in the soil absorb these substances into their bodies.
• Gradually the poison released from the chemicals moves within the body of the organisms poisoning the organic matter of the soil. This is called soil pollution due to organic matter the soil.

Question 21. What are the causes for increased levels of salinity in the soil?
Answer:

The causes of the increase in the salinity level of the soil are-

1. Intensive irrigation on farmlands increases soil salinity.
2. Continuous irrigation on the same plot of land accumulates the soluble salts which then get stored in the soil increasing its salinity.

WBBSE Chapter 8 Soil Pollution Very Short Question And Answers

Question 1. Which term is used to denote the deterioration of soil quality?
Answer: Soil pollution.

Question 2. What are burnt ash from coal and coal particles emitted along with the smoke of factories and thermal power stations collectively called?
Answer: Fly ash.

Question 3. Name a non-degradable material which blocks the sewage drains of cities.
Answer: Plastic.

Question 4. Name one radioactive pollutant.
Answer: Uranium.

Question 5. Which type of rainfall increases soil acidity?
Answer: Acid rain.

Question 6. Which poisonous substance was responsible for Bhopal Gas Tragedy?
Answer: MIC gas (Methyl Isocyanate).

Question 7. Which disaster occurred in a nuclear power station in Ukraine in 1986?
Answer: Chornobyl disaster.

Question 8. Which type of farming does not cause soil pollution?
Answer: Organic farming.

Question 9. I am a process. My harmful effect degrades the quality of soil and reduces its productivity and utility. Who am I?
Answer: Soil pollution

Question 10. Cutting us down washes the soil during heavy rainfall. Who are we?
Answer: Plants and trees

Question 11. Our application increases crop productivity but excessive use causes soil pollution. Who are we?
Answer: Chemical fertilizers

Question 12. My application kills the disease-causing microbes and both useful and harmful insects present in the soil. Who am I?
Answer: Pesticide

Question 13. I am emitted from thermal power stations and on settling down on the soil, I cause soil pollution. Who am I?
Answer: Fly ash

Question 14. I mix with rainwater, thereby increasing the soil acidity. I kill or harm organisms present in soil. Who am I?
Answer: Acid rain

Question 15. We do not decompose easily, and restrict the entry of water by clogging the soil pores. Who are we?
Answer: Plastic, polythene

WBBSE Chapter 8 Soil Pollution Fill In The Blanks

Question 1. Particles of _______ and _______ mix with rainwater causing soil pollution.
Answer: Radium, iodine

Question 2. _______ emitted from thermal power plants mixes with the soil, degrading its fertility.
Answer: Fly ash

Question 3. The excreta of humans and animals are the main source of _______ soil pollution.
Answer: Organic

Question 4. The sewage system is badly affected by improper disposal of _______.
Answer: Plastic

Question 5. An important inorganic soil pollutant is _______.
Answer: Plastic

Question 6. An example of a living soil pollutant is _______.
Answer: Protozoa

Question 7. Bacteria is an example of _______ soil pollutant.
Answer: Living

Question 8. _______ is a type of heavy metal soil pollutant.
Answer: Cadmium

Question 9. Plastic is an example of _______ soil pollutant.
Answer: Inorganic

Question 10. An example of medical waste is _______.
Answer: X-ray plate

Question 11. High amounts of accumulated pesticides in human bodies cause diseases in _______ and _______.
Answer: Lungs, stomach

Question 12. Soils which have low organic matter are _______.
Answer: Infertile

Question 13. The gas responsible for the Bhopal Gas Tragedy is _______.
Answer: MIC

Question 14. The Chornobyl Disaster took place in _______.
Answer: Ukraine

Question 15. _______ Farming reduces agricultural soil
Answer: Organic

WBBSE Chapter 8 Soil Pollution True Or False

Question 1. Acid rain does not cause soil pollution.
Answer: False

Question 2. Dead remains of plants and animals present in the soil do not form humus.
Answer: False

Question 3. Plastic is an inorganic compound which cannot be decomposed.
Answer: True

Question 4. Industrial wastes are not found in the soil of the Asansol-Durgapur industrial belt.
Answer: False

Question 5. The major cause of soil pollution in urban areas is acid rain.
Answer: True

Question 6. The waste products of hospitals cause soil pollution.
Answer: True

Question 7. Plastic and polythene substances do not cause soil pollution when in contact with soil.
Answer: False

Question 8. The garbage disposal site in Kolkata is Dhapa dumping ground.
Answer: True

Question 9. To control soil pollution, decomposed substances should be buried under the soil.
Answer: True

Question 10. Bhopal Gas Tragedy happened in 1984.
Answer: True

WBBSE Chapter 8 Soil Pollution Find The Odd One Outs

Question 1. Increasing population Deforestation: Contamination of waterbodies: Landslide
Answer: Contamination of waterbodies (not related to soil erosion)

Question 2. Chernobyl : Fukushima: Hiroshima : Bhopal
Answer: Bhopal (not related to radioactive pollution)

Question 3. Posts: Polythene : Plastic: Artificial rubber
Answer: Pests (not related to soil pollution)

Question 4. Thermal power station: Brick-kiln ash: Radioactive wastes: Landslide
Answer: Landslides (not a man-made cause of soil pollution)

WBBSE Chapter 8 Soil Pollution Correct The Following

Question 1. Water becomes polluted if the same crop is planted again and again.
Answer: Soil

Question 2. Air gets polluted if the soil is dug to make bricks for the kiln.
Answer: Soil

Question 3. 90% of the world’s population live on 90% of the landmass on the Earth.
Answer: 10%

Question 4. Only part of the Earth is water.
Answer: Land

WBBSE Chapter 8 Soil Pollution Scrambled Words

1. SANIBAONURTI
2. ERBAIACT
3. TISCIPEDE
4. ERNOBCHYL
5. OACDIVIRATITY

Answers:

1. URBANISATION
2. BACTERIA
3. PESTICIDE
4. CHERNOBYL
5. RADIOACTIVITY

WBBSE Chapter 8 Soil Pollution Match The Columns

Question 1.

Answer: 1. D, 2. A, 3. B, 4. E, 5. C

Question 2.

Answer: 1. E, 2. C, 3. D, 4. B, 5. F, 6. A

Question 3.

Answer: 1. D, 2. E, 3. A, 4. F, 5. C, 6. B