General Science Question Answers Chapter 8 Pollution Class 8 Maharashtra Board

Question Answers For All Chapters – General Science Class 8

Exercise

1. Following are some statements about pollution. Which type of pollution do they express?

(a) Fog seems to be appearing in Delhi during day hours. → Air Pollution

(b) Many times, vomiting and dysentery occur after eating ‘pani puri’. → Water Pollution

(c) Problem of sneezing occurs sometimes during a visit to the garden. → Air Pollution (due to pollen and dust)

(d) Crop does not grow up in some areas. → Soil Pollution

(e) People living in busy squares face problems like short breathing and other respiratory issues. → Air Pollution

2. Read the passage and identify the sentences expressing types of pollution.

• Heavy traffic of two-wheelers, four-wheelers, rickshaws, and buses → Air Pollution
• Nilesh is facing asthma problems → Air Pollution
• Heaps of garbage and foul smell of human and animal waste → Soil Pollution
• Blackish water with a foul smell was flowing in a stream → Water Pollution
• Nilesh developed an abdominal disease → Water Pollution

3. Match the pairs from ‘A’ and ‘B’ columns and explain the effect of pollution on human health.

4. True or False

(a) Water does not get polluted by washing clothes in the running water of a river.

→ False (It adds soap and dirt to water).

(b) More use of electric appliances causes more pollution.

→ True (Electricity generation increases pollution).

5. Answer the following:

(a) What is pollution?

• Pollution is the contamination of the natural environment, making it harmful for living beings.

(b) What are pollutants?

• Pollutants are harmful substances that cause pollution, such as smoke, dust, chemicals, and plastic waste.

(c) What is acid rain?

• Acid rain is rainfall mixed with sulfur dioxide (SO₂) and nitrogen oxides (NO₂), making it harmful for plants, animals, and buildings.

(d) What is the greenhouse effect?

• The greenhouse effect is the trapping of heat in the Earth’s atmosphere by gases like carbon dioxide (CO₂), causing global warming.

(e) Which are visible pollutants known to you?

• Smoke, dust, plastic waste, sewage water, and garbage.

(f) Which are invisible pollutants?

• Carbon monoxide (CO), methane (CH₄), sulfur dioxide (SO₂), and nitrogen oxides (NO₂).

6. Answer the following:

(a) Give two examples of each type of pollution from your residential area.

• Air Pollution – Smoke from vehicles, burning garbage.
• Water Pollution – Dumping plastic in rivers, sewage water in drains.
• Soil Pollution – Chemical fertilizers, plastic waste in soil.

(b) How does pollution occur due to vehicles? Name vehicles causing the least pollution.

• Vehicles burn petrol or diesel, releasing harmful gases like carbon monoxide (CO) and nitrogen oxides (NO₂).
• Electric vehicles and CNG-powered vehicles cause the least pollution.

(c) What are natural reasons for water pollution?

• Soil erosion, decaying plants and animals, volcanic eruptions, and algae growth.

(d) Suggest four preventive measures for air pollution.

1. Use public transport and bicycles instead of private cars.
2. Plant more trees to absorb carbon dioxide.
3. Use cleaner fuels like CNG instead of coal and petrol.
4. Install pollution control devices in factories.

(e) Explain the relation between the greenhouse effect and global warming.

• The greenhouse effect traps heat in the Earth’s atmosphere, which increases global temperatures, causing climate change, melting glaciers, and changes in weather patterns.

(f) Construct two slogans each on air, water, and soil pollution.

Air Pollution Slogans:

1. “Reduce smoke, breathe fresh!”
2. “Clean air, healthy life!”

Water Pollution Slogans:

1. “Save water, save life!”
2. “Keep rivers clean, keep the Earth green!”

Soil Pollution Slogans:

1. “Healthy soil, healthy crops!”
2. “Say no to plastic, save the land!”

7. Classify the following pollutants into natural and manmade categories: