Chapter 6 Environment Textbook Solutions

NIOS Home Science Class 10 Chapter 6

INTEXT QUESTIONS 6.1

What type of pollution is caused by the following? Tick (√) the correct option(s). You may tick more than one option wherever required.

i) vehicles air/ water/ soil/noise

ii) industry air/ water/ soil/noise

iii) dust and dirt air/ water/ soil /noise

iv) chemical wastes air/ water/ soil /noise

v) washing clothes in river air/ water/ soil /noise

vi) garbage on roadside air/ water/ soil /noise

Ans:

i) air pollution, noise pollution
ii) water pollution, air pollution
iii) air pollution
v) water pollution, air pollution
vi) water pollution
vii) soil pollution

INTEXT QUESTIONS 6.2

1. State which of the following statements are True or False. Also, correct the false statements.

i) Wind decreases the amount of dust particles in the air.

Ans: False – Wind increases the amount of dust particles in the air.

ii) Tall chimneys fitted with filters help to reduce air pollution.

Ans: True

iii) Location of factories near residential areas reduces air pollution in cities.

Ans: False – factories should be located away from cities.

iv) Adding a tall chimney to the chulha decreases air pollution.

Ans: True

2. Unscramble the given alphabet to identify sources of air pollution.

i) TRIULAUGRCAL

Ans: Agricultural

ii) ESNLOSTV

Ans: Solvents

iii) SRILADNUIT

Ans: Industrial

iv) BTNOMOICUS

Ans: Combustion

3. Suggest measures to control air pollution caused by the following pollutants:

Smoke

Poisonous gases

Ans: Use biogas, smoke less fuel. CNG should be encouraged.

INTEXT QUESTIONS 6.3

1. Tick (√) mark the correct option:

(i) Water is safe for human consumption only when it is free of

a. floating substances

b. unwanted smells

c. microorganisms

d. all the above.

Ans: d. all the above.

(ii) Domestic waste causes water pollution by discharging

a. waste water through soil to the underground

b. waste water from toilets, bathrooms, kitchens, etc., into water sources such as rivers, lakes, and pond etc.

c. waste water from factories and power plants, etc.

Ans: b. waste water from toilets, bathrooms, kitchens, etc., into water sources such as rivers, lakes, and pond etc.

(iii) Washing clothes near a water source is harmful because the dirt and soap released

a. flow into the water

b. are absorbed by the soil to reach sub-soil water

c. are left behind to create slush

d. are responsible for doing all the above.

Ans: d. are responsible for doing all the above.

2. How do oil spills in water bodies affect the plant and animal life present in them?

Ans: Oil spillage leads to water pollution, which causes a lesser availability of oxygen to aquatic plants and animals. They die because they cannot breathe without oxygen.

INTEXT QUESTIONS 6.4

1. Write two measures to control soil pollution.

Ans: Some other measures to control soil pollution are:

Use of sanitary latrines.
Limited use of insecticides and fertilizers.
Use of environment-friendly products.

2. List three methods of garbage disposal that you have seen or practiced.

Ans: Composting, segregation of waste, and recycling materials.

3. Tick (√) the correct answer:-

i) This is the latest technology in garbage disposal

a. Composting

b. Burning

c. Incineration

d. none of these

Ans: c. Incineration

ii) Harmful chemicals are left in the soil by

a. Domestic waste

b. Defecation

c. Industrial and agricultural wastes

d. Spitting

Ans: c. Industrial and agricultural wastes

4. Match the following

A	B
i) Composting	a. It becomes polluted when waste from factories is thrown on it.
ii) Spitting	b. Can be used as manure for gardening
iii) Soil	c. It may dry up and disappear, but germs remain and pollute the soil.
	d. It is banned in the metropolitan cities.

Ans: i) b ii) c iii) a

TERMINAL EXERCISE

1. Define the terms pollution and pollutant.

Ans: Pollution is the addition of any substance to the environment in excess of what is normally present, thereby making the environment impure. The substances that cause pollution are known as pollutants. It may also be defined as a constituent in the wrong amount, at the wrong place, or at the wrong time.

2. What are the sources of air pollution?

Ans:

The process of combustion causes smoke, which may come from burning of household fuel, burning of coal in thermal power stations, exhaust from automobiles, bursting of crackers, smoke from factories, spraying of insecticides and pesticides through airplanes, which spreads the poisonous substance in a large area of the atmosphere.
Use of solvents and spray paints also pollutes the environment. All these sources produce so much smoke that it is difficult to breathe. Smoke also affects our eyes and causes blindness.
Besides human beings, there are some natural sources of pollution too. These include gases emitted from volcanoes, gases produced during forest fires, and dust that spreads with the wind.

3. How can you control soil pollution?

Ans:

Proper disposal of garbage: Garbage from homes should be properly disposed of so that it does not allow flies, mosquitoes, and cockroaches to breed. At home, it must be collected in a bin which should be kept covered.
Biodegradable material can be recycled.
Dump outside the city limits: If dumping of domestic waste is done in pits that are covered with twigs and plants, the flies and mosquitoes cannot breed on it. After the pit is full, cover it with soil and let the garbage be buried.
Landfills: Low-lying areas outside the city limits and away from the source of water are selected, and garbage is dumped there every day. It produces foul smells and attracts birds, animals, and insects. But since it is outside the city, it does not affect the people very much, except when they pass the ugly site, they get the foul smell.
Composting: The garbage from gardens is put into a pit in one corner of the garden. At the end of each day, it is covered with ash and leaves. Gradually, the lower layers are converted into compost or manure. This manure can be used for gardening.
Burning of refuse: You must have seen gardeners burning leaves and grass that they have removed from gardens. Burning can produce a lot of smoke, which causes air pollution. Burning of refuse is banned in metropolitan cities since they already have a very high level of air pollution.
Incineration: The latest technology in garbage disposal is the use of an incinerator. An incinerator is a furnace in which garbage is burned. This is an expensive method because a lot of fuel is required to burn the rubbish. However, it is sterile and safe. The garbage is reduced to a relatively small heap of ash.

4. What are the effects of noise pollution?

Ans:

Noise pollution tends to disturb us, strain our nerves, cause headaches, and mental disturbance.
They can also affect the hearing ability of an individual.
Factory workers, pilots, and drivers who are exposed to very loud noise over a long period of time gradually lose the ability to hear soft sounds properly. They become hard of hearing, their eardrums get damaged, sometimes leading to deafness.
Exposure to noise pollution can also cause stress and mental instability.

5. Mention two pollutants which pollute both soil and water.

Ans: Defecation in the open and the use of chemical fertilizers.

6. How can you reduce pollution caused by smoke in your neighbourhood?

Ans:

Use a smokeless chulha at home. Provide a tall chimney to the chulha to carry the smoke away.
Use biogas, which is a smokeless fuel.
Use a solar cooker at home that uses heat from the sunlight.

7. Why should we not defecate, urinate and spit on soil?

Ans: When people defecate and urinate on the soil, then dirt, germs, and worms are generated. When somebody walks barefoot on this soil, these germs and worms enter their system and cause stomach disorders. They enter into animal and plant systems also through the food chain, thus infesting all living beings.

The urine and excreta may contain germs and worms, which enter the soil and pollute it. If it rains, the dirt flows into the nearby source of water. Some people have a bad habit of spitting anywhere and everywhere. The sputum not only spoils the surroundings but may carry disease germs. It may dry up and disappear, but the germs remain and pollute the soil.