Effects of Pollution

Answer the following questions

Question 1

What is the effect of air pollution on life in general?

Answer

Following are the effects of air pollution on life:

1. Breathing polluted air puts us at a higher risk of asthma.
2. When exposed to ground ozone for 6 to 7 hours, people suffer from respiratory inflammation.
3. Air pollutants are mostly carcinogens, and living in a polluted area can put people at risk of cancer.
4. Damages the immune system, endocrine and reproductive systems.
5. High level of air pollution has been associated with higher incidents of heart problems.
6. The toxic chemicals released into the air settle into plants and water sources. Animals eat the contaminated plants and drink the water. The poison then travels up the food chain.

Question 2

Name any three human activities which cause pollution of air.

Answer

Three human activities which cause pollution of air are:

1. Release of harmful gases and smoke from the industries.
2. Burning of fossil fuels in industries and vehicles.
3. Mining and construction activities release dust and other toxic particulate matter.

Question 3

How does increase in carbon dioxide affect atmosphere?

Answer

The increase in carbon dioxide in the atmosphere leads to increase in global temperature as it traps heat. This phenomenon of increasing global temperature is called global warming. It can affect us in many ways as it leads to climate change, frequent forest fires, melting of polar ice caps and rise in sea level, etc. It can also lead to extinction of many species.

Question 4

What are the adverse effects of radiation on human beings?

Answer

Following are the adverse effects of radiation on human beings:

1. It causes radiation sickness or acute radiation syndrome.
2. It can cause Leukaemia, abnormalities, carcinogenesis and shortening of life.
3. It causes genetic diseases due to chromosomal mutation and point mutation.
4. The genetic mutation continues for many generations causing diseases and disabilities.

Question 5

What is meant by Global warming?

Answer

The gradual increase in overall temperature of the earth's atmosphere due to increase in amount of green house gases like carbon dioxide and methane, is called global warming.

Question 6

How does soil pollution affect human life?

Answer

The effects of soil pollution on human life are:

1. Chemical fertilizers do damage when they are washed into waterways, lakes and underground aquifers. They also poison water supplies.
2. Chemical fertilisers destroy the soil's natural balance. It makes the soil vulnerable to erosion, leaves it lacking in nutrients and starts a vicious cycle in which more fertilisers must be used to make up for soil depletion.
3. Arsenic, lead, pesticides and chromium are most harmful substances which are hazardous to humans and lead to diseases.

Question 7

Suggest two ways by which atmosphere is affected by industrial pollution.

Answer

Two ways by which atmosphere is affected by industrial pollution are:

1. They release gases like carbon dioxide which causes global warming.
2. They release gases like Nitrogen oxide and sulphur oxide which causes acid rain.

Question 8

State the effects of chemicals on human beings.

Answer

Effects of chemical on human beings are:

1. Fluorides cause fluorosis, humped back, stiffness of bone joints and dental fluorosis.
2. Lead is toxic to both central and peripheral nervous system. It can accumulate in the bones.
3. Pesticides can cause tumours, chromosomal alterations, brain damage, impotency and cancer.
4. Arsenic, in mild doses, causes nausea, vomiting and stomach burns. In lethal doses, it may cause death due to shock and vascular failure.
5. Mercury damages the nervous system. It may lead to insomnia, tremors, bleeding of gums etc. Methyl mercury may cause Minamata disease which is a form of mercury poisoning.
6. High nitrate content of water is associated with methemoglobinemia. Infants are most susceptible to Nitrate content.

Question 9

What does Eutrophication mean?

Answer

Due to use of excess fertilizers, there is leaching of nitrates and phosphates into water bodies. This causes overgrowth of aquatic plants, covering the surface of water body which further leads to increased biological oxygen demand. Therefore, the process by which the excess phosphates and nitrates lead to overgrowth of algae and other aquatic plants in a water body, depleting the oxygen of water, is called Eutrophication. It leads to death of aquatic animals due to oxygen deficiency.

Question 10

Write short notes on:

1. Bhopal gas tragedy
2. Chernobyl disaster

Answer

1. Bhopal gas tragedy — The Bhopal Gas tragedy was the worst industrial accident that occurred on December 3, 1984. The accident was caused by release of 40 tonnes of methyl isocyanate (MIC) into the atmosphere from Union Carbide's pesticide factory in Bhopal, Madhya Pradesh.
   Nearly 35,000 to 40,000 people were killed. Most of the people affected had breathing problems. The gas affected their nervous system, people lost control of their bodies. Many pregnant women were affected and lost their baby.
   The blood of the victims had permanently got toxified. Methyl isocyanate also interfered severely with their reproductive ability and various plant species have suffered from chromosomal aberrations.

2. Chernobyl disaster — The Chernobyl disaster occurred on April 26, 1986 at Chernobyl Nuclear plant in Ukraine. It was one of the worst disasters in the history of nuclear power. The main reasons for this disaster were poor plant design, incompetence and poorly designed safety measures.
   Whole of Western USSR and other European countries were contaminated by gamma emissions deposited in soil, meat and dairy products were contaminated. Thousands of people became exposed to Chernobyl radiation, affecting living organisms. It caused genetic disorders, variety of cancers and Leukaemia.

Question 11

Why do people in cities suffer from viral fever, allergies etc.?

Answer

The cities are more polluted due to urbanization. Industries and vehicles release a lot of smoke into the atmosphere. Construction activities lead to dust in the atmosphere. All this makes the air polluted which further leads to fever, allergies and breathing problems etc.

Question 12

What are the effects of Noise pollution?

Answer

Following are the effects of Noise pollution:

1. Sleep disturbances
2. Hearing loss
3. Interference with communication
4. Annoyance
5. Headache
6. General fatigue
7. Rise in blood pressure
8. Problems with the digestive system.

Choose the correct option

Question 1

Which of the following substances is responsible for causing fluorosis?

1. Lead
2. Fluorides
3. Arsenic
4. Mercury

Answer

Fluorides

Question 2

Which of the following substances is responsible for causing Minamata disease?

1. Lead
2. Fluorides
3. Arsenic
4. Mercury

Answer

Mercury

Question 3

Which of the following processes is responsible for the depletion of oxygen from the water body?

1. Biomagnification
2. Bioaccumulatiom
3. Eutrophication
4. Oxygen cycle

Answer

Eutrophication

Question 4

Bhopal Gas Tragedy(3rd December,1984) was caused by the release of

1. CFC
2. Nitrogen dioxide
3. Sulphur dioxide
4. MIC

Answer

MIC

Question 5

Chernobyl disaster occurred on April 26, 1986 due to

1. Oil spillage
2. Overflow of river water
3. Meltdown in a nuclear reactor
4. Leakage of poisonous gas

Answer

Meltdown in a nuclear reactor

Question 6

The process by which the toxic compound enter a food chain & increases its concentration in the tissues of organism as it travels up the food chain is called

1. Eutrophication
2. Biomagnification
3. Bioradiation
4. Bioaccumulation

Answer

Biomagnification