Maarg Manthan · Topic 13.6

Causes and Harmful Effects of Air Pollution

Environment & Ecology › Air, Marine, Noise and Other Pollution · Topic 13.6

Air pollution is the presence in the atmosphere of gases, particles or biological material in concentrations that harm human health, living things, materials or climate. Natural sources include volcanic eruptions, dust storms, forest fires and pollen, but the major causes are human: burning of coal, oil and gas in power plants, industries and vehicles; burning of biomass for cooking and heating; open burning of crop residue and waste; construction and road dust; and industrial processes, mining and agriculture that emit ammonia and methane. Health effects include asthma, bronchitis, chronic obstructive pulmonary disease, heart disease, stroke, lung cancer, eye irritation and early death, and children and the elderly are most at risk. Other effects are acid rain, smog and haze, crop losses, damage to buildings and monuments such as the Taj Mahal, loss of biodiversity and climate change. India has the Air (Prevention and Control of Pollution) Act, 1981, the National Clean Air Programme (2019) and the Commission for Air Quality Management (2020) for Delhi and the National Capital Region.

5 min read · UPSC Prelims · Environment & Ecology · Air, Marine, Noise and Other Pollution

At a Glance

Main sources Fuel burning, dust, biomass
Key health effects Lung and heart disease
Main Act Air Act, 1981
Programme NCAP, 2019
Delhi body CAQM, 2020
Exam link UPSC Prelims, Environment & Ecology: Air, Marine, Noise and Other Pollution

Where Does It Fit?

This topic opens the main part of the macro on air pollution. It leads to the study of key gases, smog, ozone depletion and acid rain, particulates, vehicle emission norms and air quality indices. Previous topic: International and Indian Laws Regulating Mining Impact; Sustainable Mining. Next topic: Top Ten Air Pollutant Gases and Control Measures.

What Are the Causes of Air Pollution?

Source	Details
Power plants and industry	Coal and oil burning emit particulates, SO2 and NOx; cement, steel, brick kilns and refineries add to it
Vehicles	Exhaust from petrol and diesel vehicles releases CO, NOx, hydrocarbons and particulates
Biomass burning	Cooking with wood, dung and crop residue indoors and outdoors; crop residue fires in north India
Dust	Construction, road dust, mining and wind-blown soil
Waste burning	Open burning of garbage and landfill fires
Agriculture	Ammonia from fertiliser and animal waste, methane from livestock and paddy
Natural sources	Volcanoes, dust storms, wildfires, sea spray and pollen

What Are the Harmful Effects?

Respiratory: asthma, bronchitis, COPD and infections
Heart and brain: heart attack, stroke and high blood pressure from fine particles
Cancer: lung cancer from PM2.5, diesel exhaust and some gases
Children and unborn: reduced lung growth, low birth weight and early deaths
Acid rain: damages forests, lakes, soil and buildings
Smog and haze: reduce visibility and cause accidents
Crops: ozone and particles reduce yields
Climate: black carbon and greenhouse gases warm the planet

What Else Should You Remember?

Ambient air pollution: outdoor air quality
Household air pollution: indoor smoke from solid fuels, a major health risk for women and children
Ujjwala: LPG scheme begun in 2016 to cut household smoke
PM2.5: particles below 2.5 micrometres that enter deep into the lungs and bloodstream
PM10: inhalable particles below 10 micrometres
WHO guidelines: the 2021 update lowered the annual PM2.5 guideline to 5 micrograms per cubic metre
India’s PM2.5 standard: annual standard is 40 micrograms per cubic metre under NAAQS 2009
NAAQS: National Ambient Air Quality Standards set by CPCB in 2009
Air Act 1981: created State Pollution Control Boards for air and enabled air pollution control areas
1987 amendment: added noise as an air pollutant
NCAP: National Clean Air Programme, launched 2019, targeting cuts of 20 to 30 percent in PM concentrations by 2024 in 131 non-attainment cities, later revised to 40 percent by 2026
Non-attainment cities: cities that do not meet air quality standards
CAQM: Commission for Air Quality Management in the National Capital Region and Adjoining Areas, set up by law in 2021
GRAP: Graded Response Action Plan with measures that rise with pollution levels
Stubble burning: crop residue burning in Punjab, Haryana and Uttar Pradesh adds to smog around October and November
Delhi smog: winter inversion, low wind and local sources trap pollutants
Temperature inversion: warm air above cool air that traps pollution near the ground
Taj Mahal: marble yellowing is linked to particulates and SO2 and led to the Taj Trapezium Zone rules
Health burden: studies attribute well over a million deaths a year in India to air pollution; estimates vary
Economic cost: lost work days and health costs run into large amounts
Link to previous: see International and Indian Laws Regulating Mining Impact; Sustainable Mining
Link to next: see Top Ten Air Pollutant Gases and Control Measures
Link to index: see National Air Quality Index and Comprehensive Environmental Pollution Index
Caution: health burden estimates differ by study, so quote the source
Exam hint: learn the programmes with years and the main Act
Air Act 1981: the main Indian law on air pollution, with consent system for industries and standards for emissions
Black carbon: soot from diesel and biomass burning that absorbs sunlight, warms the air and darkens snow
Vulnerable groups: children, older people, outdoor workers and people with heart or lung disease face higher risk
Low-cost sensors: networks of small sensors are growing, but need calibration against reference monitors
Monitoring network: CPCB runs the National Air Quality Monitoring Programme with hundreds of stations across the country

Why Does It Matter for the Exam?

Act: Air Act 1981
Programme: NCAP 2019
Delhi body: CAQM
Current affairs link: Delhi smog and GRAP
Common errors: confusing NAAQS with the AQI

As an analytical point, India’s air problem is a mix of many sources, so cleaning it needs coordinated action on industry, transport, household fuel, farm residue and dust. Regional airsheds, not city limits, are the right unit for planning.

Why Is This Topic Important?

Sources Fuels, dust
Harm Lung, heart
Tools NCAP, CAQM

What Came Next?

The next topic covers the top ten air pollutant gases and control measures. Next topic: Top Ten Air Pollutant Gases and Control Measures.

Key People and Terms

PM2.5 Fine particles
NAAQS Air quality standards
NCAP National Clean Air Programme
CAQM Delhi NCR air commission
GRAP Graded Response Action Plan
Inversion Warm layer trapping air

Exam Corner

Points to Remember

Air Act: 1981.
NCAP: 2019.
CAQM set up 2020-21.
NAAQS: 2009.
PM2.5: below 2.5 micrometres.

Do Not Confuse With

PM2.5 and PM10 Fine versus inhalable particles
Ambient and household pollution Outdoor versus indoor
NCAP and GRAP Long-term programme versus emergency steps

Memory Hook

Burn it, drive it, sweep it, smoke it; lungs and hearts pay the cost.

Mains Angle

Questions ask for sources, effects and programmes. These points help.

Sources Many
Effects Health
Policy NCAP

A Question You May Face

An original practice question, not a past paper question.

“Discuss the causes and effects of air pollution in India and evaluate the measures taken to control it.”

How to Answer

Causes Many sources.
Effects Health.
Policy NCAP.
Way Airshed.

GS Relevance

Prelims: causes, effects, laws and programmes. GS Paper 3: air pollution and control.

Frequently Asked Questions

What are the main causes of air pollution in India?

The main causes are burning of coal and other fuels in power plants and industries, exhaust from vehicles, use of biomass for cooking, open burning of crop residue and garbage, dust from construction, roads and mining, brick kilns, and emissions of ammonia and methane from agriculture. Weather conditions such as winter inversion trap pollutants.

How does air pollution affect health?

Air pollution, especially fine particles, causes asthma, bronchitis, chronic lung disease, infections, heart disease, stroke and lung cancer. It also harms children's lung growth and pregnancy outcomes, and increases early deaths. Studies attribute well over a million deaths a year in India to air pollution, though estimates vary.

What is the National Clean Air Programme?

The National Clean Air Programme, launched in 2019, is a time-bound programme to cut air pollution in 131 non-attainment cities that do not meet national standards. It originally aimed to reduce PM10 and PM2.5 concentrations by 20 to 30 percent by 2024, a target later revised to 40 percent by 2026, using city action plans.

What is the Commission for Air Quality Management?

The Commission for Air Quality Management in the National Capital Region and Adjoining Areas is a statutory body created by a 2020 ordinance and Act of 2021 to coordinate, research and resolve air quality problems in Delhi NCR and nearby states. It has powers to issue binding directions on matters such as stubble burning, industry and construction.

What is the Air Act, 1981?

The Air (Prevention and Control of Pollution) Act, 1981 is India's main law on air pollution. It set up the Central and State Pollution Control Boards for air matters, allows declaration of air pollution control areas, sets emission standards and consent requirements for industries, and was amended in 1987 to include noise as an air pollutant.

PYQ Practice — Statement Analysis

1 The Air Act was passed in 1981.

True

It created pollution control boards for air.

2 PM10 particles are smaller than PM2.5.

False

PM2.5 is smaller.

3 NCAP was launched in 2019.