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:
Knowledge2. Acid rain is caused by:
Knowledge3. Eutrophication is caused by:
Knowledge4. The unit of measuring noise pollution is:
Knowledge5. The process of using microorganisms to clean pollutants is:
Knowledge6. The most polluted river in India is:
Knowledge7. Smog is a mixture of:
Knowledge8. The Chernobyl disaster was related to:
Knowledge9. Assertion (A): CNG is better than petrol for vehicles. Reason (R): CNG produces less pollutants.
Assertion-Reasoning10. The full form of BOD is:
Knowledge11. The gas responsible for ozone depletion is:
Knowledge12. The pollution caused by excessive heat is:
Knowledge13. The 3R principle for pollution control includes:
Knowledge14. The international agreement to control global warming is:
Knowledge15. The organ most affected by air pollution is:
Application