Science Class 8 - Pollution Of-Air-And-Water Notes

Pollution of Air and Water

Welcome to the chapter on Pollution of Air and Water for Class 8. In this chapter, you will learn what pollution is, its causes, effects, and how we can reduce pollution to keep our environment clean and healthy. By the end of this chapter, you will understand the importance of clean air and water and ways to prevent pollution.

Introduction

Pollution means making our environment dirty and harmful. Air and water pollution are two major problems that affect our health and the planet. Let’s learn more about them!

What is Air Pollution?

Air pollution happens when harmful substances like smoke, dust, and gases mix with the air. This makes the air unsafe to breathe.

• Sources: Factories, vehicles, burning garbage, and firecrackers.
• Pollutants: Carbon monoxide, sulfur dioxide, nitrogen oxides, particulate matter.

Effects of Air Pollution

• Breathing problems and diseases like asthma.
• Damage to plants and animals.
• Global warming and climate change.
• Smog and poor visibility.

What is Water Pollution?

Water pollution happens when harmful substances mix with water in rivers, lakes, and oceans. This makes water unsafe for drinking and other uses.

• Sources: Factories, sewage, agricultural chemicals, plastic waste.
• Pollutants: Chemicals, heavy metals, oil, plastics, germs.

Effects of Water Pollution

• Diseases like cholera and typhoid.
• Death of fish and other aquatic animals.
• Dirty water is unsafe for drinking and bathing.
• Polluted water harms crops and soil.

How Can We Reduce Pollution?

• Use public transport, cycle, or walk instead of using cars.
• Plant more trees to clean the air.
• Do not throw garbage in rivers and lakes.
• Use less plastic and recycle waste.
• Treat sewage and industrial waste before releasing it into water bodies.
• Spread awareness about pollution and its effects.

Fun Activity: Pollution Survey

Observe your surroundings and list sources of air and water pollution. Discuss with your friends how you can help reduce pollution.

Summary

• Air and water pollution are harmful to health and the environment.
• Pollution is caused by human activities like burning, dumping waste, and using chemicals.
• We can reduce pollution by changing our habits and spreading awareness.

Practice Questions

1. Name two sources of air pollution.
2. What are the effects of water pollution?
3. How can planting trees help reduce air pollution?
4. Why should we treat sewage before releasing it into rivers?
5. List two ways to reduce pollution in your school.

Challenge Yourself

• Make a poster to spread awareness about pollution.
• Write a short paragraph on how you can help keep your city clean.

Did You Know?

• The Ganga and Yamuna are two rivers in India that suffer from water pollution.
• Air pollution can travel from one city to another with the wind.

Glossary

• Pollution: Making the environment dirty and harmful.
• Pollutant: A substance that causes pollution.
• Sewage: Waste water from homes and factories.
• Smog: Thick, dirty air caused by smoke and fog.

Answers to Practice Questions

1. Factories, vehicles (any two sources).
2. Diseases, death of aquatic animals, dirty water, harm to crops.
3. Trees absorb harmful gases and give us clean oxygen.
4. To prevent waterborne diseases and protect aquatic life.
5. Use dustbins, avoid plastic, plant trees, spread awareness (any two).

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Keep your air and water clean—help protect our planet!