📌 Chapter Snapshot
6
Types of Pollution
6
Water-related health/cause groups
Area/time
Noise limits vary by zone and day/night
1981
Air Pollution Act
- This chapter covers all major types of environmental pollution — Air, Water, Soil, Noise, Radioactive, and Solid Waste — with their causes, impacts, and government control measures.
- Special focus on disease-pollutant matching (Minamata-Methylmercury, Itai-Itai–Cadmium, etc.) which is a very common BPSC/BSSC MCQ pattern.
⚡ QUICK RECALL
Disease-Cause matching: Minamata → Methylmercury | Itai-Itai → Cadmium | Black Foot → Arsenic | Blue-baby Syndrome → Nitrates.
🧪 Pollutants — Primary & Secondary
| Primary Pollutants | Secondary Pollutants |
|---|---|
| CO, SO2, NO/NOx, NH3, VOCs and primary particulate matter (direct emissions) | O3, PAN, HNO3, H2SO4 and secondary sulfate/nitrate particles (formed in air) |
⚠ EXAM TRAP
Primary pollutants are emitted directly (CO, SO₂); secondary pollutants (O₃, Acid Rain components) FORM in the atmosphere from reactions between primary pollutants — don't classify Ozone or Acid Rain as primary.
💨 Air Pollution
| Causes | Pollutants | Impacts |
|---|---|---|
| Fossil fuels (incomplete combustion of coal, petrol), industrial waste, harmful gases from vehicles, fine particulate matter, etc. | Gases: CO, SO2, NOx, ground-level O3, NH3, VOCs | Particles: PM2.5/PM10, dust, smoke, soot, fly ash | Asthma, eye irritation, respiratory diseases, brain and kidney disorders, lung cancer, etc. |
⚡ QUICK RECALL
Government efforts against air pollution: Air (Prevention and Control of Pollution) Act, 1981 & National Air Quality Monitoring Programme.
💧 Water Pollution
- Undesirable gases, liquids, and solids getting mixed into water.
| Human Induced Causes | Natural Causes |
|---|---|
| Domestic/Industrial waste, use of chemicals & pesticides in agriculture, oil spills, nuclear waste, etc. | Volcanic ash, dust, organic waste from forests, etc. |
Water-related health/cause groups & Their Cause/Agent
| Disease | Cause / Agent |
|---|---|
| Jaundice | Hepatitis A/E can cause jaundice; jaundice is a symptom |
| Minamata Disease | Methylmercury |
| Blue-baby Syndrome | Nitrates |
| Cholera, Typhoid, Dysentery | Cholera: Vibrio cholerae; typhoid: Salmonella Typhi; dysentery: bacterial or amoebic |
| Itai-Itai Disease | Cadmium |
| Black Foot Disease | Arsenic |
⚡ QUICK RECALL
BOD (Biochemical Oxygen Demand) = dissolved oxygen consumed by microorganisms decomposing biodegradable organic matter under specified test conditions; higher BOD generally indicates greater biodegradable organic pollution.
⚠ EXAM TRAP
Government efforts: Ganga Action Plan (older) vs Namami Gange Programme (current, comprehensive) — both target Ganga river conservation, but are different schemes from different eras.
🌍 Soil Pollution
- Soil Pollution → Degradation of soil quality.
| Causes | Measures | Impacts |
|---|---|---|
| Use of chemicals, soil erosion, overuse of fertilisers, industrial/urban waste, etc. | Control on chemical fertilisers, disposal of solid waste, use of bioremediation techniques, ban on nuclear explosions, etc. | Loss of essential soil properties, decline in fertility, spread of diseases through soil |
🔊 Noise Pollution
- Noise pollution is unwanted/excessive sound affecting health or well-being. No universal 65 dB threshold: permissible limits depend on area and day/night.
| Natural Causes | Human-Induced Causes |
|---|---|
| Thunder of clouds, earthquake sounds, thunder & lightning | Industrial units, vehicle noise, use of entertainment devices (loudspeakers, radios), etc. |
Impacts
- Hearing impairment/tinnitus, sleep disturbance, annoyance/stress, hypertension/cardiovascular effects and impaired performance.
Measures to Control Noise Pollution
- Use of noise barrier materials
- Tree plantation (along transport routes)
- Regulation of loudspeakers, horns, etc.
- Use of sound absorbers
- Town planning arrangements
- Awareness and education, etc.
Permissible Ambient Noise Levels: dB(A) Leq
| Area Type | Day Time [dB(A) Leq] | Night Time [dB(A) Leq] |
|---|---|---|
| Industrial area | 75 | 70 |
| Commercial area | 65 | 55 |
| Residential area | 55 | 45 |
| Silent zone | 50 | 40 |
⚠ EXAM TRAP
Silent zone has the LOWEST permissible noise limits (50 dB day / 40 dB night) — even lower than residential areas. Frequently swapped in MCQs.
☢ Radioactive Pollution
- Pollution caused by radiation from radioactive substances (Uranium, Thorium, Plutonium, etc.).
| Natural Sources | Man-made Sources |
|---|---|
| Radon, natural radionuclides in rocks/soil, terrestrial gamma and cosmic radiation | Nuclear testing, nuclear weapons, nuclear reactors, uranium mining, etc. |
Impacts
- Long-term consequences: genetic mutations, cancer, tumor and infertility.
- Affects structure of DNA, RNA and protein.
- Bone cancer → caused by Strontium-90.
- Iodine-131 is preferentially taken up by the thyroid gland.
🗑 Solid Waste Pollution
SourcesHouseholds, markets, commercial/institutional premises; hazardous, biomedical, e-waste, batteries and radioactive waste have separate rules
Disposal MethodsSegregate; reuse/recycle; compost/biomethanate suitable organic waste; controlled energy recovery; landfill residual rejects
- E-Waste (Electronic Waste) → waste from TV, fridge, computer, mobile, etc.
- Incinerators → controlled high-temperature combustion in an engineered facility with emission controls.
📋 Master Quick-Revision Table
| Topic | Key Fact |
|---|---|
| Primary Pollutants | CO, SO2, NO/NOx, NH3, VOCs, primary PM | Direct emissions |
| Secondary Pollutants | O3, PAN, HNO3, H2SO4, secondary sulfate/nitrate particles |
| Air Pollution Act | 1981 |
| Jaundice | Hepatitis A/E can cause jaundice; jaundice is a symptom |
| Minamata Disease | Methylmercury |
| Blue-baby Syndrome | Nitrates in water |
| Itai-Itai Disease | Cadmium |
| Black Foot Disease | Arsenic |
| BOD | Biochemical Oxygen Demand | O₂ for decomposition by microorganisms |
| Namami Gange Programme | Ganga river conservation effort |
| Noise Pollution | Unwanted/excessive sound; limits vary by area and day/night |
| Industrial area noise limit | Day: 75 dB | Night: 70 dB |
| Residential area noise limit | Day: 55 dB | Night: 45 dB |
| Silent zone noise limit | Day: 50 dB | Night: 40 dB |
| Radioactive Pollution cause | Radiation from Uranium, Thorium, Plutonium, etc. |
| Bone cancer — element | Strontium-90 |
| Thyroid uptake - radionuclide | Iodine-131 |
| E-Waste | Waste from TV, fridge, computer, mobile, etc. |
| Incinerators | Controlled high-temperature combustion with emission controls |
| Solid Waste disposal | Prevent/minimise; segregate; reuse/recycle; biological treatment; controlled recovery; landfill rejects |