←
Environment, Sustainable Development and Disaster Management · Chapter 2

Pollution and Waste Management

What to remember

  • A pollutant is any substance in the wrong place, in the wrong amount, that harms living things. Pollution is grouped as air, water, soil, noise, thermal and radioactive.
  • Water quality is judged by dissolved oxygen (DO) and biochemical oxygen demand (BOD): high BOD and low DO mean heavy organic pollution.
  • Waste is managed by the 5 R's and by rules: Solid Waste, Plastic Waste, E-Waste and Bio-Medical Waste Rules each place duties on producers, local bodies and users.

Air pollution

Primary pollutants enter the air directly: carbon monoxide (CO), sulphur dioxide (SO2), oxides of nitrogen (NOx), particulate matter (PM), and hydrocarbons. Secondary pollutants form in the air from reactions, such as ground-level ozone and PAN (peroxyacetyl nitrate).

PollutantMain sourceMain effect
Carbon monoxideIncomplete burning of fuel, vehiclesBinds haemoglobin, reduces oxygen carried by blood
Sulphur dioxideCoal-burning power plants, smeltersRespiratory illness, acid rain
Oxides of nitrogenVehicles, power plantsSmog, acid rain, lung damage
PM10 and PM2.5Dust, burning, diesel enginesEnter lungs; PM2.5 can reach the blood
LeadLeaded petrol (now phased out)Harms the nervous system in children

Smog: *Classical (London) smog* is smoke plus fog, rich in SO2, and occurs in cool, humid air. *Photochemical (Los Angeles) smog* forms from vehicle fumes in strong sunlight and contains ozone and PAN.

Indoor air pollution: from firewood and cow-dung chulhas; it harms women and children most. LPG schemes such as Ujjwala address it.

Control methods: Electrostatic precipitators (ESP) and bag filters remove particles. Scrubbers remove gases like SO2. Catalytic converters change CO, NOx and hydrocarbons into CO2, N2 and water. Cleaner fuels, Bharat Stage emission norms, public transport, and green belts also help. The National Ambient Air Quality Standards (NAAQS) set permitted levels. The Air Quality Index (AQI) puts air quality into easy categories from good to severe.

Bhopal gas tragedy (1984) was caused by a leak of methyl isocyanate (MIC). It led to the Environment (Protection) Act, 1986.

Water pollution

Point sources are single outlets (factory pipe). Non-point sources are spread out (farm run-off).

Major pollutants and effects:

  • Sewage and organic waste: raise BOD, reduce DO, cause diseases like cholera and typhoid.
  • Fertiliser run-off (nitrates and phosphates): cause eutrophication, an algal bloom that uses up oxygen and kills fish.
  • Heavy metals: mercury caused Minamata disease; cadmium caused Itai-itai disease; arsenic in groundwater causes skin and other illnesses.
  • Excess fluoride causes fluorosis (bone and teeth damage). Excess nitrate in drinking water is linked to "blue baby" syndrome (methaemoglobinaemia).
  • Thermal pollution: warm water from power plants lowers DO.
  • Oil spills: coat birds and marine life.

Dissolved oxygen should be adequate for fish. BOD is the oxygen needed by microbes to break down organic matter in water. COD (chemical oxygen demand) measures oxygen needed to chemically oxidise all matter.

Treatment of sewage: primary (screening, settling), secondary (biological, using bacteria, activated sludge), and tertiary (disinfection, nutrient removal). Water supply uses sedimentation, filtration and chlorination. Namami Gange and river-cleaning programmes work on sewage treatment and river-front management.

Soil pollution

Causes include excess fertilisers and pesticides, industrial waste, mining, plastic, and irrigation with polluted water. It lowers soil fertility and enters the food chain. Salinisation (salt build-up) and waterlogging are common problems in badly managed irrigated land. Control involves organic farming, integrated pest management, crop rotation, and safe disposal of waste.

Noise pollution

Noise is unwanted sound, measured in decibels (dB). Prolonged exposure causes hearing loss, stress, high blood pressure and poor sleep. Under the Noise Pollution (Regulation and Control) Rules, 2000, ambient limits differ by zone and by day (6 am to 10 pm) and night.

ZoneDay dB(A)Night dB(A)
Industrial7570
Commercial6555
Residential5545
Silence zone5040

Silence zones are areas near hospitals, schools and courts. Control is by silencers, sound barriers, trees, and limits on loudspeakers and horns.

Solid waste management

Classification by source: municipal (household), industrial, agricultural, biomedical, e-waste, construction and demolition. By nature: biodegradable (food, leaves) and non-biodegradable (plastic, glass, metal).

The 5 R's: Refuse, Reduce, Reuse, Recycle, Recover. Methods of disposal: sanitary landfill, composting, vermicomposting, incineration, and biomethanation (gas from waste). Open dumping and burning are harmful. Segregation at source into wet, dry and hazardous waste is the first step.

Solid Waste Management Rules, 2016 placed duties on waste generators to segregate, and on local bodies to collect and process. They were superseded by the Solid Waste Management Rules, 2026 (notified 27 January 2026, in force from 1 April 2026), which make four-stream segregation (wet, dry, sanitary, special care) mandatory and apply the polluter pays principle through environmental compensation. Swachh Bharat Mission supports sanitation and waste processing.

Plastic, e-waste and biomedical waste

  • Plastic Waste Management Rules, 2016 (amended later) introduced Extended Producer Responsibility (EPR), which makes producers and brand owners responsible for end-of-life plastic. Bans on selected single-use plastic items were brought in by later amendments.
  • E-Waste (Management) Rules cover old computers, phones and appliances. EPR applies to producers, and recycling must be done by authorised recyclers. E-waste has toxic metals like lead, mercury and cadmium, and also valuable metals.
  • Bio-Medical Waste Management Rules, 2016 use colour-coded bins:
ColourWaste
YellowHuman and animal anatomical waste, soiled waste
RedContaminated recyclable plastics (tubing, bottles, gloves)
White (translucent)Sharps (needles, scalpels) in puncture-proof boxes
BlueGlassware and metallic body implants

Bioremediation

Bioremediation uses living organisms, mostly microbes, to clean polluted soil and water.

  • Biostimulation: adding nutrients to boost native microbes.
  • Bioaugmentation: adding special microbes.
  • Phytoremediation: using plants to absorb or break down pollutants (for example, sunflower and mustard for metals).
  • Microbes that eat oil are used after oil spills.

It is usually cheaper and gentler than digging up soil or burning waste, but it can be slow.

Other pollution types and monitoring

  • Radioactive pollution: from nuclear accidents, mining and medical or industrial isotopes. Radiation damages cells and genes. Chernobyl (1986) and Fukushima (2011) are well-known accidents.
  • Thermal pollution: raises water temperature and lowers dissolved oxygen.
  • Light pollution: excess artificial light that harms sleep and night-flying animals.
  • Marine pollution: oil, plastics, sewage and ship waste. Plastic breaks into microplastics, which enter the food chain.

Pollution control institutions: The Central Pollution Control Board (CPCB) and State Pollution Control Boards monitor air and water quality and set standards. The polluter pays principle says the one who causes harm must pay for the damage. The precautionary principle says action should be taken even if science is not fully certain.

Landfills and leachate: A sanitary landfill is lined at the bottom to stop leachate (liquid that drains from waste) from reaching groundwater. Methane from landfills can be captured as fuel. Unlined dumps pollute soil, water and air.

Pollution issues in Andhra Pradesh

  • Industrial clusters near the coast, such as around Visakhapatnam, need strict control of air, water and chemical safety.
  • Kolleru Lake has faced pollution and silting from aquaculture ponds and waste carried in by drains.
  • Coastal and river-delta areas face pollution from farm run-off and urban sewage, so sewage treatment plants and monitoring are needed.
  • The Andhra Pradesh Pollution Control Board gives consent to industries, monitors air and water, and enforces the national Acts in the State.
  • Municipal bodies in AP run door-to-door waste collection and promote wet and dry waste segregation, following the national rules.

Waste hierarchy and useful terms

The best way to handle waste is not to make it. The preferred order is: prevent, reduce, reuse, recycle, recover energy, and last of all, dispose. Landfilling is the last choice.

  • Vermicomposting uses earthworms to turn kitchen and farm waste into rich manure.
  • Incineration burns waste at high temperature, cuts volume, and can make energy, but needs filters for harmful gases.
  • Pyrolysis heats waste without oxygen to give oil, gas and char.
  • Sewage sludge can be dried and used as manure after treatment.
  • Hazardous waste (toxic, corrosive, flammable, reactive) needs special storage and treatment.

Exam traps

  • 1. BOD high means water is more polluted, not cleaner.
  • 2. Eutrophication is caused by nutrients, not by toxic metals.
  • 3. Minamata is mercury; Itai-itai is cadmium.
  • 4. CO binds haemoglobin; SO2 causes acid rain.
  • 5. London smog (cool, humid, SO2) differs from photochemical smog (sunlight, ozone).
  • 6. Yellow bin is anatomical waste; white bin is sharps.
  • 7. Bioaugmentation adds microbes; biostimulation adds nutrients.
  • 8. Silence zone limits are lower than residential limits.

One-liners

  • 1. Bhopal gas leak involved methyl isocyanate.
  • 2. The Environment (Protection) Act of 1986 followed Bhopal.
  • 3. PM2.5 means particles smaller than 2.5 micrometres.
  • 4. Catalytic converters reduce CO, NOx and hydrocarbons.
  • 5. Electrostatic precipitators remove particulate matter.
  • 6. Noise is measured in decibels.
  • 7. Fluoride excess causes fluorosis.
  • 8. Nitrate excess causes blue baby syndrome.
  • 9. EPR makes producers responsible for end-of-life products.
  • 10. Sharps go into white translucent containers.
  • 11. Composting and vermicomposting suit biodegradable waste.
  • 12. Phytoremediation uses plants to clean pollution.

Practice questions

  1. Which gas binds with haemoglobin and reduces oxygen supply to the body?

    1. Sulphur dioxide
    2. Methane
    3. Carbon dioxide
    4. Carbon monoxide
    Answer

    D. Carbon monoxide

    CO binds haemoglobin more strongly than oxygen does.

  2. Acid rain is mainly caused by oxides of

    1. carbon and hydrogen
    2. sulphur and nitrogen
    3. argon and neon
    4. phosphorus and calcium
    Answer

    B. sulphur and nitrogen

    SO2 and NOx form sulphuric and nitric acids.

  3. Which is a secondary air pollutant?

    1. Soot
    2. Carbon monoxide
    3. Peroxyacetyl nitrate (PAN)
    4. Sulphur dioxide
    Answer

    C. Peroxyacetyl nitrate (PAN)

    PAN forms in the air from reactions of primary pollutants.

  4. Photochemical smog needs which condition to form?

    1. Cold fog and coal smoke
    2. Heavy rain
    3. Volcanic ash only
    4. Strong sunlight and vehicle emissions
    Answer

    D. Strong sunlight and vehicle emissions

    Sunlight drives reactions among NOx and hydrocarbons.

  5. Which device removes fine particles from industrial exhaust using an electric charge?

    1. Electrostatic precipitator
    2. Cyclone dryer
    3. Scrubber
    4. Catalytic converter
    Answer

    A. Electrostatic precipitator

    ESPs charge particles and collect them on plates.

  6. A catalytic converter in a vehicle mainly converts

    1. water into hydrogen
    2. CO2 into oxygen
    3. CO, NOx and hydrocarbons into less harmful gases
    4. dust into ash
    Answer

    C. CO, NOx and hydrocarbons into less harmful gases

    It changes harmful gases into CO2, N2 and water.

  7. The Bhopal gas tragedy of 1984 involved the leak of

    1. chlorine
    2. methyl isocyanate
    3. sulphur dioxide
    4. ammonia
    Answer

    B. methyl isocyanate

    MIC leaked from a pesticide plant.

  8. Eutrophication is caused mainly by excess

    1. oil and grease
    2. nitrates and phosphates
    3. lead and mercury
    4. radioactive wastes
    Answer

    B. nitrates and phosphates

    Nutrients cause algal blooms that use up oxygen.

  9. Minamata disease is linked to pollution by

    1. mercury
    2. cadmium
    3. fluoride
    4. arsenic
    Answer

    A. mercury

    Mercury-polluted seafood caused Minamata disease in Japan.

  10. Itai-itai disease is caused by

    1. nitrate
    2. mercury
    3. lead
    4. cadmium
    Answer

    D. cadmium

    Cadmium poisoning caused bone damage in Japan.

  11. Excess fluoride in drinking water causes

    1. cholera
    2. blue baby syndrome
    3. fluorosis
    4. goitre
    Answer

    C. fluorosis

    Fluorosis damages teeth and bones.

  12. Blue baby syndrome is linked to high levels of ... in drinking water

    1. chloride
    2. nitrate
    3. iron
    4. fluoride
    Answer

    B. nitrate

    Nitrate causes methaemoglobinaemia in infants.

  13. BOD stands for

    1. biological organic decay
    2. basic oxygen deficiency
    3. biochemical oxygen demand
    4. bacterial oxidation degree
    Answer

    C. biochemical oxygen demand

    BOD is the oxygen microbes need to break down organic matter.

  14. A high BOD value of a water sample means

    1. heavy organic pollution
    2. very clean water
    3. no microbes
    4. high dissolved oxygen
    Answer

    A. heavy organic pollution

    More organic matter needs more oxygen to decompose.

  15. Warm water released by power plants into rivers causes

    1. soil erosion
    2. acid rain
    3. noise pollution
    4. thermal pollution
    Answer

    D. thermal pollution

    Warm water lowers dissolved oxygen.

  16. Primary treatment of sewage involves

    1. biological digestion by microbes
    2. chemical disinfection only
    3. nutrient removal only
    4. screening and settling
    Answer

    D. screening and settling

    Primary treatment is physical removal of solids.

  17. Activated sludge is used in which stage of sewage treatment?

    1. Secondary treatment
    2. Chlorination of drinking water
    3. Screening
    4. Primary treatment
    Answer

    A. Secondary treatment

    Secondary treatment uses microbes to break down organic matter.

  18. Noise is measured in

    1. lux
    2. pascals per metre
    3. hertz only
    4. decibels
    Answer

    D. decibels

    The decibel is the unit of sound level.

  19. The Noise Pollution Rules, 2000 define day time as

    1. 5 am to 8 pm
    2. 6 am to 10 pm
    3. 6 am to 6 pm
    4. 7 am to 9 pm
    Answer

    B. 6 am to 10 pm

    Day is 6 am to 10 pm; night is 10 pm to 6 am.

  20. Which zone has the lowest permitted day-time noise limit?

    1. Residential zone
    2. Commercial zone
    3. Silence zone
    4. Industrial zone
    Answer

    C. Silence zone

    Silence zones have a day limit of 50 dB(A).

  21. Which colour bin is used for sharps such as needles under Bio-Medical Waste Rules, 2016?

    1. Red
    2. White (translucent)
    3. Blue
    4. Yellow
    Answer

    B. White (translucent)

    Sharps go in puncture-proof white containers.

  22. Contaminated recyclable plastic like tubing goes in which bin?

    1. Yellow
    2. White
    3. Red
    4. Blue
    Answer

    C. Red

    Red bins collect contaminated recyclable plastics.

  23. Human anatomical waste is disposed of in which colour bin?

    1. Yellow
    2. Red
    3. Blue
    4. White
    Answer

    A. Yellow

    Yellow is for anatomical and soiled waste.

  24. Glassware and metallic implants belong in which bin?

    1. Red
    2. Blue
    3. Yellow
    4. White
    Answer

    B. Blue

    Blue is for glass and metal items.

  25. Extended Producer Responsibility (EPR) means

    1. producers are responsible for the end-of-life of their products
    2. consumers pay the tax on waste
    3. local bodies make all products
    4. imports are banned
    Answer

    A. producers are responsible for the end-of-life of their products

    EPR makes producers and brand owners manage waste of their products.

  26. Which method uses earthworms to make manure from waste?

    1. Pyrolysis
    2. Landfilling
    3. Incineration
    4. Vermicomposting
    Answer

    D. Vermicomposting

    Earthworms digest organic waste into vermicompost.

  27. Which is the last and least preferred option in the waste hierarchy?

    1. Reuse
    2. Reduce
    3. Disposal in landfill
    4. Recycle
    Answer

    C. Disposal in landfill

    Prevention and reuse come first.

  28. Liquid that drains from a landfill and can pollute groundwater is called

    1. slag
    2. leachate
    3. effluent gas
    4. sludge
    Answer

    B. leachate

    Leachate forms when water passes through waste.

  29. Using plants to absorb or break down pollutants is called

    1. phytoremediation
    2. biostimulation
    3. pyrolysis
    4. bioaugmentation
    Answer

    A. phytoremediation

    Phyto means plant; remediation means cleaning.

  30. Adding special microbes to a polluted site is called

    1. phytoremediation
    2. biostimulation
    3. composting
    4. bioaugmentation
    Answer

    D. bioaugmentation

    Bioaugmentation adds microbes; biostimulation adds nutrients.

  31. Adding nutrients to boost native microbes at a polluted site is called

    1. bioleaching
    2. bioaugmentation
    3. biostimulation
    4. biomagnification
    Answer

    C. biostimulation

    Biostimulation feeds the microbes already present.

  32. Tiny plastic pieces that enter the food chain are called

    1. bioplastics
    2. nanogels
    3. polyamides
    4. microplastics
    Answer

    D. microplastics

    Microplastics come from broken-down plastic.

  33. The 'polluter pays principle' means

    1. the polluter bears the cost of damage
    2. the government pays all clean-up costs
    3. pollution is free
    4. the victim pays for protection
    Answer

    A. the polluter bears the cost of damage

    The one causing harm pays.

  34. Consider the statements: 1. PM2.5 particles are smaller than PM10 particles. 2. PM2.5 cannot enter the lungs. Which of the statements is/are correct?

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    PM2.5 is finer and can go deep into lungs, even the blood.

  35. Consider the statements: 1. Sulphur dioxide from coal burning contributes to acid rain. 2. Carbon monoxide is the main cause of eutrophication. Which of the statements is/are correct?

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    Eutrophication comes from nutrients such as nitrates and phosphates.

  36. Consider the statements: 1. High dissolved oxygen indicates good water quality. 2. High BOD indicates clean water. Which of the statements is/are correct?

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    High BOD means heavy organic load.

  37. Consider the statements: 1. Lead is a toxic metal found in e-waste. 2. E-waste contains only harmless materials. Which of the statements is/are correct?

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    E-waste has toxic metals as well as valuable ones.

  38. Consider the statements: 1. Salinisation and waterlogging can damage irrigated soil. 2. Composting is a method for managing biodegradable waste. Which of the statements is/are correct?

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    C. Both 1 and 2

    Both statements are correct.

  39. Consider the statements: 1. Segregation of waste at source is the first step in solid waste management. 2. Open burning of waste is a recommended method. Which of the statements is/are correct?

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    Open burning pollutes air and is discouraged.

  40. Consider the statements: 1. Catalytic converters reduce emissions from vehicles. 2. Silence zones have higher noise limits than industrial zones. Which of the statements is/are correct?

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    A. 1 only

    Silence zones have the lowest noise limits.

  41. Consider the statements: 1. Photochemical smog contains ozone and PAN. 2. London smog is rich in SO2 and forms in cool, humid air. Which of the statements is/are correct?

    1. 1 only
    2. 2 only
    3. Both 1 and 2
    4. Neither 1 nor 2
    Answer

    C. Both 1 and 2

    Both describe the two types of smog correctly.

  42. Match the pollutant with its effect. 1. Mercury 2. Cadmium 3. Fluoride 4. Nitrate A. Fluorosis B. Minamata C. Blue baby syndrome D. Itai-itai

    1. 1-D, 2-B, 3-A, 4-C
    2. 1-B, 2-D, 3-A, 4-C
    3. 1-A, 2-B, 3-D, 4-C
    4. 1-B, 2-D, 3-C, 4-A
    Answer

    B. 1-B, 2-D, 3-A, 4-C

    Each pollutant is matched with its known disease.

  43. Match the bin colour with the waste. 1. Yellow 2. Red 3. White 4. Blue A. Sharps B. Anatomical waste C. Glass D. Contaminated plastics

    1. 1-B, 2-A, 3-D, 4-C
    2. 1-B, 2-D, 3-A, 4-C
    3. 1-D, 2-B, 3-A, 4-C
    4. 1-C, 2-D, 3-A, 4-B
    Answer

    B. 1-B, 2-D, 3-A, 4-C

    Yellow anatomical, red plastics, white sharps, blue glass.

  44. Which Act was passed after the Bhopal gas tragedy as an umbrella law?

    1. Forest (Conservation) Act, 1980
    2. Water Act, 1974
    3. Air Act, 1981
    4. Environment (Protection) Act, 1986
    Answer

    D. Environment (Protection) Act, 1986

    EPA 1986 followed the 1984 Bhopal disaster.

  45. Which treatment method burns waste at high temperature and can recover energy?

    1. Sanitary landfilling
    2. Composting
    3. Incineration
    4. Vermicomposting
    Answer

    C. Incineration

    Incineration reduces volume and can generate energy but needs gas filters.

Page 1 of 1
‹
›