MCQs on Soil Pollution

Soil pollution is an important chapter in the environmental chemistry syllabus that focuses on educating the students about the causes of soil pollution, the harmful effects of soil pollution, harmful pollutants and so on. It is important to know thoroughly about the common aspects of this chapter since it has a good weightage in the NEET exam paper. So, in order to score high marks, students should be able to understand the basic causes and effects of soil pollution.

What is Soil Pollution?

The contamination or degradation of soil due to the presence of impurities like chemicals, xenobiotics, toxic wastes, plastic, etc that alters the natural composition of the soil is termed soil pollution. There are many causes that lead to soil pollution. Some of them are-

Acidification of soil by acid rain

• long term leaching of base

• microbial respiration

• Nitrification

• excessive land-use practices

• use of inorganic nitrogen fertilizers

• land drainage

Also, the main Chemicals involved in causing soil pollution are 

• Hydrocarbons

• Heavy metals

• Pesticides

• Solvents

All these processes and causes lead to the production of either H+ ions or CO₂ which further get dissolved into soil water and form carbonic acid. Such soil is not good for cultivation. 

The basic cause of soil pollution is toxic chemicals mixing in the upper nutritious soil. These toxins and pesticides or herbicides continue to induce long-term ill effects on human health, nature and on the soil environment. 

Also, 'Soil erosion is also related to 'soil pollution. It is because, due to the loss of the upper layer of soil, the functioning of soil is being affected in terms of crop growth and many other things.

Types of Soil Pollution:

Agricultural Soil Pollution

1. It leads to pollution of surface soil

2. When the agricultural pollution is not taken care of, it causes pollution of underground soil.

Soil Pollution by Industrial Activities

1. pollutes the surface soil.

2. It also causes disturbance in the soil profile.

Pollution Due to Urban Activities 

1. These include urbanization and acts of deforestation etc.

2. Usage of chemicals also causes soil/land pollution in an indirect way. 

Along With This, There is a Category-wise Division of Soil Pollution 

• Negative soil pollution

• Positive soil pollution

the table below describes both the types:

Contaminants in the Soil

A wide range of contaminants have the potential to contaminate the soil. The following are some of the most prevalent and troublesome soil contaminants.

Lead Poisoning

One of the most frequent elements in our planet is lead. As heavier atoms decay to lead, it is becoming more frequent in the cosmos, and there are enough lead resources on Earth, therefore we may presume there will be no lead scarcity in the near future.

Even the tiniest amounts of lead may be harmful, especially if they are maintained over time. Even in modest dosages, it is exceedingly poisonous to young children, and at higher amounts, it may be lethal to people in general.

Symptoms of Lead Poisoning Include

• Loss of weight

• Mood disorders and irritability

• Problems with learning

• Vomiting and abdominal cramps

• Fatigue

• Problems with the nervous system

• Headache

• Autism in persons who are genetically susceptible

• Reduction in growth

• The pituitary-thyroid endocrine system is harmed.

Mercury Poisoning

The elimination of mercury from most commercially accessible items in the United States is due to multiple studies confirming its high toxicity. Because mercury may exist in a variety of forms - metal, vapor, or salt – and in a variety of compounds, we may not always be aware that we have come into touch with it. Mercury poisoning, on the other hand, maybe ingested or absorbed through the skin, and it is exceedingly deadly. As a result, they began to show signs of "madness," i.e., mercury poisoning:

• Muscle atrophy and weakness

• The sense of tingling in one's limbs

• Impairment of speech

• Loss of coordination and balance

• Tremors

• Depression and mood swings

• Headaches

• Brain injury that is severe

• Itching, burning, and discomfort

• Brain, kidney, and lung damage

Effect of Soil Pollution 

The soil pollution can make the land lose its fertility and make it unfit for growing crops. Generally, crops cannot be grown and nourished in polluted soil.

Soil pollution also affects the predators of that region and forces them to move to other places where soil is healthy. 

During rainfall, when the waterfalls on polluted soil or land, it makes the water Ph rise and makes it unfit for human use. 

Soil pollution can also cause leaching of the chemicals and harmful products from the polluted land to the water supply pipelines that contain drinking water as well. Soil pollution is also responsible for the clogging of drains.

People coming in contact with soil pollution on a daily basis have higher risks of migraines, nausea, fatigue, skin disorders skin irritation etc.

Sometimes, when the crops are unknowingly grown in the polluted soil, it absorbs the chemicals and pollutants which are toxic in nature. When these crops grow and reach the consumption stage, it causes serious health issues to the consumer. 

Soil also has some long-term effects that are responsible for many harmful, deadly diseases and imbalances in the human body. Due to soil pollution, humans can suffer from cancer, leukemia, reproductive disorders, kidney and liver damage, and central nervous system failure.

Soil Pollutions is Either- Naturally Caused or Anthropogenic Means

Natural Soil Pollution occurs mostly by the accumulation of compounds containing the perchlorate anions. Or, sometimes, some contaminants are naturally produced in the soil under the effect of certain environmental conditions. 

On the other hand, Anthropogenic pollution of soil is common and occurs in most cases. Many human activities pollute the soil. These include:

• The demolition of old buildings releases a lot of wastes and this can involve the contamination of nearby soil with asbestos.

• Usage of lead-based paint during construction activities pollutes the soil with hazardous lead wastes.

• Spillage of petrol and diesel during transportation contaminates soil with the hydrocarbons found in petroleum.

• Activities associated with metal casting factories mostly cause the dispersion of metallic contaminants into the nearby soils. This in turn poses a major soil pollution threat.

• Underground mining activities may contaminate the layers of soil with heavy metals.

• Improper disposal of highly toxic industrial waste can severely pollute the soil. For example, the storage of toxic wastes in landfills can result in the seepage of the waste into the upper layers of soil. This waste may even pollute the groundwater reserves by easily coming in contact with it.

• Chemical pesticides contain several hazardous pollutants. So,  use of chemical pesticides can result in severe soil pollution.

• Sewage produced in urbanized areas can also contaminate soil due to improper disposal. These wastes may also contain several carcinogenic substances which may pollute the soil badly.

•  Improper drainage systems and pipelines can also cause soil pollution that takes place in urban cities. 

Measures to Control of Soil Pollution: 

Soil pollution can be controlled by the following measures

• Recycling of plastic and other harmful waste products.

• banning the use of non-degradable plastic.

• Avoiding deforestation and disturbance to plant surroundings.

• Recycling paper, plastic and other degradable material.

• Undertaking pollution awareness programs and awarding large numbers of people about soil pollution and its control.

• Using eco-friendly fertilizers and pesticides.

• Making the sewage systems apart from the land area that has chances to be polluted.

• Using soil in a suitable way for farming and not overusing it. 

• By encouraging plantation programs.

Conclusion

Soil pollution is the contamination or deterioration of soil caused by impurities such as chemicals, xenobiotics, hazardous wastes, plastic, and other substances that change the soil's natural makeup. Soil contamination is caused by a variety of factors. Toxic chemicals mixing in with the top, nourishing soil is the primary source of soil contamination.

Let’s Have a Look at Some Solved Multiple Choice Questions on Soil Pollution.

MCQs on Soil Pollution

1. What is negative Soil Pollution?

1. It indicates a reduction in soil productivity due to erosion and overuse

2. Reduction in soil productivity due to the addition of pesticides

3. Converting fertile land into hardened land by dumping ash, sludge and garbage

4. None of the above

Answer: (A)

2. The quantity of DDT at each trophic level in the Food Chain

1. Decreases

2. Remains the same

3. Increases

4. Changes

Answer: (c)

3. DDT is a major contributor to Pollution because of

1. It kills useful microorganisms

2. It destroys valuable species of worms

3. It is nonbiodegradable

4. It interferes with pesticides

Answer: (c)

4. The chemicals released due to unsustainable agricultural practices and cause Soil Pollution are

1. Pathogens

2. Chemical fertilizers

3. Strontium-90

4. Weedicides

Answer: (b)

5. Slash and burn agriculture, which is not a healthy technique of farming and depletes soil of the important nutrients, is a part of which of the following?

1. Striping farming

2. Intercrop farming

3. Jhum cultivation

4. None of the above

Answer: (c)

6. In a coal-fired power plant Electrostatic precipitators are installed to control the emission of

1. SO₂

2. NO₂

3. SPM

4. CO

Answer: (c) 

7. How are PAHs related to Soil Pollution?

1. They are carcinogenic organic compounds

2. They are fertilizer wastes

3. They are inorganic wastes from industries

4. They are harmful metals that pollute the soil

Answer: (a)

 8. Soil pollution due to PAHs can be sourced to

1. vehicle emissions

2. cigarette smoke

3. extraction of shale oil

4. All of the above

Answer: (d)

9. Benzene and Methylbenzene the major Soil Pollutants mostly from the Petroleum Industries are

1. Heavy organic pollutants

2. Inorganic pollutants

3. Carcinogenic pollutants

4. None of the above

Answer: (c)

10. Which of these pollutants is a Herbicide?

1. PHPs

2. Amides

3. Chlorinated hydrocarbons

4. Copper Sulfate

Answer: (b)

11. Which of the following serves as an indicator of Atmospheric Pollution

1. Fern

2. Liverworts

3. Hornworts

4. Epiphytic lichens

Answer: (d)

12. Why is area treatment important for Soil?

1. To reduce the impact of raindrops on the soil

2. To maximize surface run-off

3.  Not treating the upper catchment and proceeds towards an outlet

4. Not storing surplus rainwater

Answer: (A)

13. Which type of land/soil pollution cause makes soil unfit for cultivation due to high salt content?

1. Carbonisation

2. Oxygenation

3. Salinization

4. Desertification

Answer: (C)