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Pollution

ICSE Grade 10 Biology - Chapter 17

📚 Smart Summary

1. Introduction to Pollution

Pollution: Introduction of harmful substances into environment that cause adverse effects.

Pollutants: Substances that cause pollution. Can be physical, chemical, or biological.

Types: (1) Air pollution, (2) Water pollution, (3) Soil pollution, (4) Noise pollution, (5) Radioactive pollution, (6) Thermal pollution.

Sources: (1) Natural (volcanoes, forest fires), (2) Anthropogenic (human activities).

Effects: (1) Harm to human health, (2) Ecosystem damage, (3) Climate change, (4) Biodiversity loss.

Diagram Importance: Diagram showing types of pollution and their sources is essential.

2. Air Pollution

Air Pollution: Presence of harmful substances in air that affect human health and environment.

Major Pollutants: (1) Carbon monoxide (CO), (2) Sulfur dioxide (SO₂), (3) Nitrogen oxides (NOx), (4) Particulate matter (PM), (5) Volatile organic compounds (VOCs), (6) Ozone (O₃).

Sources: (1) Vehicular emissions, (2) Industrial emissions, (3) Burning fossil fuels, (4) Agricultural activities, (5) Construction dust.

Effects: (1) Respiratory diseases, (2) Acid rain, (3) Global warming, (4) Smog formation, (5) Ozone depletion.

Acid Rain: Caused by SOâ‚‚ and NOx. Damages buildings, forests, aquatic life.

Smog: Mixture of smoke and fog. Photochemical smog in urban areas.

Control Measures: (1) Use of CNG, (2) Catalytic converters, (3) Afforestation, (4) Industrial emission standards.

Diagram Importance: Diagram of air pollution sources and effects is crucial.

3. Water Pollution

Water Pollution: Contamination of water bodies with harmful substances.

Pollutants: (1) Industrial effluents, (2) Sewage, (3) Agricultural runoff (fertilizers, pesticides), (4) Oil spills, (5) Heavy metals.

Sources: (1) Domestic sewage, (2) Industrial waste, (3) Agricultural runoff, (4) Mining activities.

Effects: (1) Eutrophication, (2) Harm to aquatic life, (3) Waterborne diseases, (4) Bioaccumulation of toxins.

Eutrophication: Excessive nutrients cause algal bloom, depleting oxygen, killing aquatic life.

BOD (Biochemical Oxygen Demand): Measure of organic pollution. High BOD indicates polluted water.

Control Measures: (1) Sewage treatment, (2) Industrial effluent treatment, (3) Use of biofertilizers, (4) Oil spill cleanup.

Diagram Importance: Water pollution cycle and eutrophication diagram are important.

4. Soil Pollution

Soil Pollution: Degradation of soil quality due to harmful substances.

Pollutants: (1) Pesticides, (2) Fertilizers, (3) Industrial waste, (4) Heavy metals, (5) Plastic waste.

Sources: (1) Excessive use of agrochemicals, (2) Industrial dumping, (3) Mining activities, (4) Improper waste disposal.

Effects: (1) Reduced soil fertility, (2) Harm to soil organisms, (3) Contamination of food chain, (4) Desertification.

Soil Erosion: Loss of topsoil due to wind, water, deforestation.

Control Measures: (1) Organic farming, (2) Crop rotation, (3) Proper waste management, (4) Afforestation.

Diagram Importance: Soil pollution sources and effects diagram is useful.

5. Noise Pollution

Noise Pollution: Unwanted sound that disrupts normal activities.

Sources: (1) Traffic, (2) Construction, (3) Industrial machinery, (4) Loud music, (5) Aircraft.

Measurement: Decibel (dB) scale. 0 dB (threshold), 140 dB (pain threshold).

Effects: (1) Hearing loss, (2) Stress, (3) Sleep disturbance, (4) Cardiovascular problems.

Permissible Limits: 55 dB (night), 65 dB (day) in residential areas.

Control Measures: (1) Soundproofing, (2) Traffic regulation, (3) Use of silencers, (4) Plantation of trees.

Diagram Importance: Noise levels chart and sources diagram are helpful.

6. Radioactive Pollution

Radioactive Pollution: Pollution due to radioactive substances.

Sources: (1) Nuclear power plants, (2) Nuclear testing, (3) Medical waste, (4) Mining of radioactive materials.

Pollutants: Radioactive isotopes like strontium-90, iodine-131, cesium-137.

Effects: (1) Genetic mutations, (2) Cancer, (3) Birth defects, (4) Environmental contamination.

Chernobyl Disaster: 1986 nuclear accident. Released radioactive materials affecting Europe.

Control Measures: (1) Proper nuclear waste disposal, (2) International regulations, (3) Monitoring radiation levels.

7. Thermal Pollution

Thermal Pollution: Increase in temperature of water bodies due to human activities.

Sources: (1) Discharge of hot water from industries, (2) Power plants, (3) Deforestation.

Effects: (1) Reduced dissolved oxygen, (2) Harm to aquatic life, (3) Altered metabolic rates, (4) Ecosystem imbalance.

Control Measures: (1) Cooling towers, (2) Effluent treatment, (3) Planting trees around water bodies.

8. Pollution Control and Prevention

3R Principle: (1) Reduce - minimize waste, (2) Reuse - use items multiple times, (3) Recycle - convert waste to new products.

Government Measures: (1) Environmental laws (EPA in India), (2) Pollution control boards, (3) International agreements (Kyoto Protocol, Paris Agreement).

Individual Actions: (1) Use public transport, (2) Conserve energy, (3) Proper waste disposal, (4) Plant trees.

Sustainable Development: Development that meets present needs without compromising future generations.

Bioremediation: Use of microorganisms to clean polluted environments.

Case Studies: (1) Ganga Action Plan, (2) Delhi air pollution control, (3) Plastic ban initiatives.

🎯 Test Your Knowledge

Multiple Choice Questions

1. The main cause of air pollution is:

2. Acid rain is caused by:

3. Eutrophication is caused by:

4. The unit of measuring noise pollution is:

5. The process of using microorganisms to clean pollutants is:

6. The most polluted river in India is:

7. Smog is a mixture of:

8. The Chernobyl disaster was related to:

9. Assertion (A): CNG is better than petrol for vehicles. Reason (R): CNG produces less pollutants.

10. The full form of BOD is:

11. The gas responsible for ozone depletion is:

12. The pollution caused by excessive heat is:

13. The 3R principle for pollution control includes:

14. The international agreement to control global warming is:

15. The organ most affected by air pollution is: