CBSE Class 10 · Manufacturing Industries

Industrial Pollution and Its Control Class 10: Types and Measures

Updated 14 October 2026 · Fact-checked

Industries cause four types of pollution: air, water, land and noise, and thermal power plants are among the polluters. Smoke and gases foul the air, effluents and hot water foul rivers, dumped wastes ruin soil and groundwater, and machines cause noise. Controls include recycling water, harvesting rain, treating effluents in three stages, smoke-stack filters, silencers and green belts.

Notice that a factory causes four kinds of pollution, and each one has a matching control shown in green below it.

Illustration drawn for QuestionBuddy.

Understand Industrial Pollution and Its Control

The problem. Industries contribute greatly to India's growth, but the pollution of land, water and air, the noise and the environmental degradation they cause cannot be overlooked. Industries are responsible for four types of pollution: air, water, land and noise. Thermal power plants are also polluters.

1. Air pollution.

Caused by a high proportion of undesirable gases such as sulphur dioxide and carbon monoxide, and air-borne particulate matter (solid and liquid particles such as dust, sprays, mist and smoke).
Smoke comes from chemical and paper factories, brick kilns, refineries, smelting plants, and burning of fossil fuels in factories that ignore pollution norms.
Toxic gas leaks can be very hazardous with long-term effects (NCERT reminds us of the Bhopal Gas tragedy).
Air pollution harms human health, animals, plants, buildings and the atmosphere.

2. Water pollution.

Caused by organic and inorganic industrial wastes and effluents discharged into rivers.
Main culprits: paper, pulp, chemical, textile and dyeing, petroleum refineries, tanneries and electroplating industries, releasing dyes, detergents, acids, salts, heavy metals like lead and mercury, pesticides, fertilisers, synthetic chemicals, plastics and rubber.
Fly ash, phospho-gypsum and iron and steel slags are India's major solid wastes.
Thermal pollution of water: hot water from factories and thermal plants drained into rivers and ponds before cooling, which harms aquatic life.
Wastes from nuclear power plants and nuclear and weapon facilities cause cancers, birth defects and miscarriages.

3. Land (soil) pollution. Soil and water pollution are closely related. Dumping glass, harmful chemicals, industrial effluents, packaging, salts and garbage makes soil useless. Rainwater carries pollutants down, contaminating groundwater too.

4. Noise pollution. Causes irritation and anger, and can lead to hearing impairment, increased heart rate and blood pressure. Sources: industrial and construction activity, machinery, factory equipment, generators, saws and pneumatic and electric drills.

Control of environmental degradation.

Every litre of industrial waste water pollutes eight times its quantity of freshwater. To reduce this:

1. minimise water use by reusing and recycling it in two or more stages;
2. harvest rainwater to meet water needs;
3. treat hot water and effluents before releasing them.

Effluent treatment in three phases:
Primary: mechanical (screening, grinding, flocculation, sedimentation);
Secondary: biological process;
Tertiary: biological, chemical and physical processes, including recycling of wastewater.
Groundwater: overdrawing by industry where reserves are threatened should be regulated legally.
Air: fit smoke stacks with electrostatic precipitators, fabric filters, scrubbers and inertial separators; use oil or gas instead of coal to reduce smoke.
Noise: fit generators with silencers, redesign machinery for energy efficiency and less noise, use noise-absorbing material and personal earplugs and earphones.

NTPC shows the way. NTPC, a major power corporation with ISO 14001 certification for its Environment Management System, preserves the environment through: optimum use of equipment with the latest techniques; minimising waste by maximising ash utilisation; green belts for ecological balance; ash pond management, ash water recycling and liquid waste management; and ecological monitoring and online database management for its power stations. The lesson: sustainable development requires integrating economic development with environmental concerns.

Industrial Pollution and Its Control: key facts

Four types of industrial pollution: Air, water, land, noise (thermal plants among polluters)
Air pollution: Sulphur dioxide, carbon monoxide + particulates (dust, sprays, mist, smoke); chemical and paper factories, brick kilns, refineries, smelting plants; Toxic leaks: Bhopal Gas tragedy.
Water pollution: Paper, pulp, chemical, textile and dyeing, refineries, tanneries, electroplating; lead, mercury; solid wastes: fly ash, phospho-gypsum, steel slags; Thermal pollution: hot water into rivers.
Water saving rule: 1 litre of industrial waste water pollutes 8 times its quantity of freshwater
Effluent treatment: Primary (mechanical: screening, grinding, flocculation, sedimentation) -> secondary (biological) -> tertiary (biological, chemical, physical; recycling)
Air and noise controls: Electrostatic precipitators, fabric filters, scrubbers, inertial separators; oil or gas instead of coal; silencers; redesigned machinery; earplugs
NTPC example: ISO 14001 EMS; latest techniques; ash utilisation; green belts; ash pond and water recycling; ecological monitoring; Model of sustainable industry.

How to answer Industrial Pollution and Its Control questions

Questions ask for types of industrial pollution, their sources and effects, how to control pollution of freshwater or air, the stages of effluent treatment, or NTPC's practices.

1For 'types', name all four and give one source and one effect each.
2For water, separate chemical pollution (effluents) from thermal pollution (hot water).
3For control of freshwater pollution, give the three suggestions and the three treatment stages.
4For air and noise, name specific devices: precipitators, scrubbers, silencers.
5For NTPC, list at least three practices and link to sustainable development.
6End 5-mark answers with the need to integrate development with environmental concerns.

Industrial Pollution and Its Control in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Treating effluents before release

Suppose a textile dyeing unit near your town drains coloured, warm water straight into a stream, and fish begin to die downstream.

Identify the types of pollution involved and suggest how the unit should treat its waste water.

Try it first, then show the solutionSolution

Identify chemical water pollution from dyes and thermal pollution from warm water.
Primary treatment: screening, grinding, flocculation, sedimentation.
Secondary: biological treatment; tertiary: biological, chemical and physical processes with recycling.
Also recycle water and cool hot water before release.

Answer: The unit is causing water pollution through dyes and chemicals, and thermal pollution through warm water, both of which harm aquatic life. It should treat effluents in three phases: primary mechanical treatment (screening, grinding, flocculation, sedimentation), secondary biological treatment, and tertiary biological, chemical and physical treatment with recycling. It should also reuse water in several stages and cool hot water before releasing it.

Memory hook: Screen it, digest it, clean it, then reuse it.

Tricks to remember Industrial Pollution and Its Control

Short memory aids. Say each one aloud once, then use it on a question the same day.

A-W-L-N
Air, Water, Land, Noise: 'All Wastes Leave Noise'.
Use it when: Four types of pollution.
P-S-T treatment
Primary = Physical/mechanical, Secondary = Smart bugs (biological), Tertiary = Total (bio + chem + physical, recycling).
Use it when: Effluent treatment stages.
1 pollutes 8
One litre of waste water spoils eight litres of freshwater.
Use it when: Why water control matters.
PFSI air filters
Precipitators, Fabric filters, Scrubbers, Inertial separators.
Use it when: Air pollution control.

Industrial Pollution and Its Control: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Thermal pollution · 1 mark · MCQBoard level

Thermal pollution of water occurs when:
(a) chemicals are dumped on land
(b) hot water from factories is drained into rivers before cooling
(c) smoke is released from chimneys
(d) machines make loud noise

Try it first, then show the solutionSolution

NCERT defines thermal pollution of water as hot water from factories and thermal plants drained into rivers and ponds before cooling (1 mark).

Answer: (b) hot water from factories is drained into rivers before cooling

Example 2: Reducing freshwater pollution (2 marks) · 2 marks · Very short answerBoard level

Suggest two ways in which industries can reduce the pollution of freshwater. (2 marks)

Try it first, then show the solutionSolution

Minimise water use by reusing and recycling it in two or more successive stages; harvest rainwater to meet water needs (1 mark).
Treat hot water and effluents before releasing them into rivers and ponds (1 mark).

Answer: Industries can reuse and recycle water in two or more stages, and harvest rainwater, so they draw less freshwater. They should also treat hot water and effluents before releasing them into rivers and ponds.

Example 3: Assertion-reason: soil and water · 1 mark · Assertion-reasonHarder board level

Assertion (A): Soil pollution by industries can also contaminate groundwater.
Reason (R): Rainwater percolating into the soil carries pollutants down to the groundwater.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.

Try it first, then show the solutionSolution

NCERT explains that soil and water pollution are closely related because rain carries pollutants down (1 mark).

Answer: (a) Both A and R are true, and R is the correct explanation of A.

Example 4: Types of industrial pollution (5 marks) · 5 marks · Long answerHarder board level

'Industries contribute significantly to India's growth, but the degradation they cause cannot be overlooked.' Examine the statement by analysing the sources and effects of the four types of industrial pollution. (5 marks)

Try it first, then show the solutionSolution

Air: sulphur dioxide, carbon monoxide and particulates from chemical and paper factories, brick kilns, refineries and smelting plants; harms health, animals, plants, buildings (1 mark).
Water: effluents from paper, pulp, chemical, textile, dyeing, refineries, tanneries and electroplating with dyes, acids, lead and mercury (1 mark).
Thermal water pollution from hot water, and nuclear wastes causing cancers and birth defects (1 mark).
Land: dumping glass, chemicals, effluents, packaging, salts and garbage makes soil useless and contaminates groundwater (1 mark).
Noise: from machinery, generators, saws and drills; causes irritation, hearing impairment, higher heart rate and blood pressure (1 mark).

Answer: Air pollution comes from gases like sulphur dioxide and carbon monoxide and from smoke and dust released by chemical and paper factories, brick kilns, refineries and smelting plants; it harms people, animals, plants and buildings. Water pollution comes from effluents of paper, pulp, chemical, textile and dyeing units, refineries, tanneries and electroplating units, carrying dyes, acids and heavy metals such as lead and mercury. Hot water from factories causes thermal pollution, and nuclear wastes cause cancers and birth defects. Land pollution results from dumping glass, chemicals, packaging, salts and garbage, which makes soil useless and contaminates groundwater. Noise from machinery, generators and drills causes stress, hearing loss and higher blood pressure.

Example 5: Case: NTPC shows the way · 4 marks · Case-basedHOTS / competency

Read the case and answer the questions.

NCERT describes NTPC, a major power-providing corporation with ISO 14001 certification for its Environment Management System. It preserves natural resources where it sets up plants by using the latest techniques and upgrading equipment, maximising ash utilisation to cut waste, providing green belts, managing ash ponds and recycling ash water and liquid waste, and keeping up ecological monitoring and online databases for all its power stations.

(i) What is ISO 14001 certification for? (1)
(ii) Name one way NTPC reduces waste. (1)
(iii) Why does NCERT present NTPC as an example of sustainable development? (2)

Try it first, then show the solutionSolution

(i) For its Environment Management System (EMS) (1 mark).
(ii) Maximising ash utilisation (or ash water recycling, liquid waste management) (1 mark).
(iii) It produces power, which the economy needs, while reducing pollution and protecting resources (1 mark).
(iii) This integrates economic development with environmental concerns, which is what sustainable development requires (1 mark).

Answer: (i) For its Environment Management System. (ii) By maximising ash utilisation (also ash water recycling and liquid waste management). (iii) NTPC keeps producing electricity that the economy needs while cutting waste, protecting water and other resources and planting green belts. It integrates economic development with environmental concerns, which is the core of sustainable development.

Example 6: Effluent treatment stages (2 marks) · 2 marks · Very short answerHarder board level

Describe the three phases of treatment of industrial effluents. (2 marks)

Try it first, then show the solutionSolution

Primary treatment by mechanical means: screening, grinding, flocculation and sedimentation (1 mark).
Secondary by a biological process; tertiary by biological, chemical and physical processes including recycling of wastewater (1 mark).

Answer: Primary treatment is mechanical: screening, grinding, flocculation and sedimentation. Secondary treatment uses a biological process, and tertiary treatment uses biological, chemical and physical processes, including recycling the wastewater.

Where students lose marks in Industrial Pollution and Its Control

The slips examiners see most often, and what to write instead.

Mistake: Forgetting thermal pollution
Students think pollution means chemicals only.
Wrong working
Water pollution is caused only by chemicals.
Right working
Hot water from factories and thermal plants also causes thermal pollution.
Do this: Add the hot-water point.
Usually costs: 1 mark.
Mistake: Mixing up treatment stages
Three similar terms.
Wrong working
Primary treatment is biological.
Right working
Primary mechanical, secondary biological, tertiary biological + chemical + physical.
Do this: P-S-T.
Usually costs: 1 mark.
Mistake: Generic control answers
Writing 'plant trees' only.
Wrong working
Pollution can be controlled by planting trees.
Right working
Recycling water, effluent treatment, precipitators and scrubbers, silencers, green belts.
Do this: Name devices and processes.
Usually costs: 2 marks.
Mistake: Listing pollution without sources
Only types are named.
Wrong working
Industries cause air and water pollution.
Right working
Air from brick kilns, refineries; water from tanneries, dyeing units.
Do this: Type + source + effect.
Usually costs: 2 marks.

Exam tips

Learn one source and one effect for each of the four pollution types.
Quote 'one litre pollutes eight' to open any freshwater pollution answer.
Use NTPC as your case example of sustainable industry.
Geography has no 3-mark answers in 2026-27.

Practice questions on Industrial Pollution and Its Control

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
Which of the following is a major solid waste of industries in India?
(a) Fly ash
(b) Carbon monoxide
(c) Hot water
(d) Noise
Hint
Also phospho-gypsum and steel slags.
Answer
(a) Fly ash
Q2 · 2 marks · Very short answerBoard level
How can particulate matter in the air from factories be reduced? (2 marks)
Hint
Devices on smoke stacks; fuel change.
Answer
By fitting smoke stacks with electrostatic precipitators, fabric filters, scrubbers and inertial separators. Smoke can also be reduced by using oil or gas instead of coal.
Q3 · 1 mark · Assertion-reasonHarder board level
Assertion (A): Noise pollution is only an irritation and has no effect on health.
Reason (R): Industrial machinery, generators, saws and drills make a lot of noise.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is not the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Hint
What physical effects does NCERT list?
Answer
(d) A is false, but R is true. Noise can cause hearing impairment and raise heart rate and blood pressure.
Q4 · 2 marks · Very short answerHOTS / competency
Suppose a factory near a residential area runs diesel generators all night. Suggest two measures from NCERT to reduce the noise. (2 marks)
Hint
Silencers and redesign.
Answer
Fit the generators with silencers, and redesign or replace machinery to be more energy-efficient and quieter; noise-absorbing material can also be used around them.
Q5 · 5 marks · Long answerHarder board level
'Every litre of waste water discharged by our industry pollutes eight times the quantity of freshwater.' Explain how industries can control water and groundwater pollution. (5 marks)
Hint
Use less, harvest, treat in three stages, regulate groundwater.
Answer
Because waste water spoils many times its volume of freshwater, industries must first use less: they can reuse and recycle water in two or more stages and harvest rainwater to meet their needs. Second, hot water and effluents should be treated before release. Treatment has three phases: primary mechanical treatment by screening, grinding, flocculation and sedimentation; secondary treatment by a biological process; and tertiary treatment by biological, chemical and physical processes, which includes recycling the wastewater. Third, where groundwater is under threat, overdrawing of groundwater by industry should be regulated legally. Avoiding dumping of chemicals and waste on land also protects groundwater from pollutants carried down by rain.
Q6 · 2 marks · Very short answerHOTS / competency
Analyse why using oil or gas instead of coal in factories can help reduce air pollution, yet may not solve all industrial pollution. (2 marks)
Hint
Smoke vs other pollutants.
Answer
NCERT says smoke can be reduced by using oil or gas instead of coal, cutting particulate air pollution. But factories still cause water, land and noise pollution, so other measures such as effluent treatment and silencers are also needed.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.Name two gases that cause air pollution.Show answer
Sulphur dioxide and carbon monoxide.
2.Name two heavy metals released into water by industries.Show answer
Lead and mercury.
3.What does primary treatment of effluents involve?Show answer
Screening, grinding, flocculation and sedimentation.
4.What certification does NTPC have?Show answer
ISO 14001 for its Environment Management System.
5.Name two health effects of noise pollution.Show answer
Hearing impairment and increased heart rate or blood pressure.

Industrial Pollution and Its Control: frequently asked questions

What are the types of industrial pollution?

Air, water, land and noise pollution; thermal power plants and hot-water discharges also pollute.

How can industrial pollution be controlled?

By recycling water, harvesting rain, treating effluents in three stages, fitting smoke stacks with precipitators and scrubbers, using oil or gas instead of coal, and fitting silencers.

What is thermal pollution?

Pollution caused when hot water from factories and thermal plants is drained into rivers and ponds before cooling, which harms aquatic life.

Why is NTPC an example of good practice?

It uses the latest techniques, maximises ash utilisation, creates green belts, recycles ash water and monitors ecology at its power stations.