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Air Pollution in India, Causes, Effects, Sources, Challenges

A recent study titled ‘Respirer Reports Analysis of Air Quality in October for the past five years’ by Respirer Living Sciences reveals significant air pollution trends in India’s major state capitals.

Air Pollution

According to the definition of Air Pollution, it occurs when contaminants that are bad for the environment and human health are released into the atmosphere. The World Health Organization (WHO) estimates that seven million people die worldwide each year as a result of air pollution. Presently, nine out of ten people breathe air that is more polluted than recommended by the WHO.

Gases (including ammonia, carbon monoxide, sulphur dioxide, nitrous oxides, methane, carbon dioxide, and chlorofluorocarbons), particles (both organic and inorganic), and biological molecules are just a few examples of the many diverse forms of air pollution. Primary pollutants are those substances that directly contribute to air pollution. The creation of secondary pollutants comes from the blending and interaction of primary pollutants. You can prepare for the UPSC Civil Service Exam’s environment subject by reading this article, which will explain air pollution.

Current Situation of Air Pollution in India

  • India faces a severe air pollution crisis, significantly affecting public health and the economy.
  • It has 63 of the world’s 100 most polluted cities; New Delhi is the most polluted capital globally.
  • 5 levels are of particular concern, exceeding WHO recommended levels by more than 10 times.
  • Life expectancy impacts and substantial economic costs are associated with this issue.

Health Impacts

  • The high pollution levels are shortening life expectancy by about 10 years in some cities.
  • 5 particles pose serious health risks due to their ability to penetrate deep into the lungs and bloodstream.

Economic Impacts

  • The cost of air pollution in India exceeds USD 150 billion annually.

Findings of the Respirer Reports Analysis of Air Quality

  • Increasing Pollution in Delhi: Over the last two years, Delhi has experienced a sharp rise in PM 2.5 pollution. In October 2021, the PM 2.5 concentration was measured at 74.0 μg/m3, which escalated by approximately 54% to 113.9 μg/m3 by October 2023. This level is alarmingly above the safety thresholds set by both the Central Pollution Control Board and the World Health Organization.
  • Mumbai’s Deteriorating Air Quality: Mumbai has seen its PM 2.5 levels more than double from 27.7 μg/m3 in October 2019 to 58.3 μg/m3 four years later, marking a 110% increase.
  • Rising Pollution in Hyderabad and Kolkata: After a brief improvement in 2022, Hyderabad’s air quality worsened with an 18.6% increase in PM 2.5 levels in October 2023.
    • Kolkata also recorded a 40.2% hike in PM 2.5 levels compared to the previous year’s data for the same month.
  • Reduction in PM 2.5 Levels in Other Capitals: In contrast, Lucknow, Patna, Bengaluru, and Chennai showed a decrease in PM 2.5 levels in October 2023, with Chennai registering a notable reduction of over 23%.

Check here: Pollution in Delhi

Air Pollution Causes

1. Fossil Fuels

Sulfur dioxide, which is released through the burning of fossil fuels like coal, petroleum for energy in power plants, and other industrial combustibles, is one of the main causes of Air Pollution. The energy for the hundreds of millions of cars and trucks on the road comes from the combustion of gasoline and diesel fuel. Hydrocarbons, which make up petroleum, do not burn cleanly in engines.

Due to the emission of pollutants from trucks, jeeps, cars, trains, and aeroplanes, such as PM, nitric oxide, and NO2 (together referred to as NOx), carbon monoxide, organic compounds, and lead, high pollution levels arise. Along with nitrogen oxides, which are produced by both natural and man-made processes, carbon monoxide is another significant pollutant that is released by vehicles and is caused by improper or incomplete combustion.

2. Agricultural Activities

A byproduct of agriculture, ammonia is one of the most hazardous substances in the atmosphere. Nowadays, fertilizers, pesticides, and insecticides are employed extensively in agricultural practices. They can contaminate water and discharge dangerous chemicals into the air. In order to prepare the land for a new cycle of sowing, farmers also set fire to the fields and previous crops. It is alleged that clearing fields by burning them will contaminate the air by producing dangerous pollutants.

3. Waste on Landfills

The places where trash is buried or put are called landfills. These dumped or buried wastes generate methane. An important greenhouse gas that is highly flammable and hazardous is methane. Another severe problem is e-waste, which entails a number of unethical activities such as chemical leaks and burning wires.

4. Industrial Dust and Waste

A substantial amount of carbon monoxide, hydrocarbons, organic substances, and chemicals are released into the air by manufacturing industries, reducing air quality. Additionally, hydrocarbons and a number of other pollutants are released by petroleum refineries, harming the air and land.

5. Mining Operation

Mining is the use of large machinery to remove minerals from below the surface of the earth. During the process, chemicals and dust are released into the air, causing serious air pollution. This is one of the elements causing the local population’s and workers’ declining health.

  • Indoor Pollution: Hazardous chemicals are released into the air by household cleaning goods and painting supplies, damaging the environment.
  • Natural Factors: The air is contaminated by some naturally occurring events, such as volcanoes, forest fires, and dust storms.

Air Pollutants Sources

1. Carbon Monoxide

It is a colourless, odourless gas that is produced when carbon-based fuels like gasoline, diesel, and wood, as well as organic and synthetic materials like cigarettes, burn incompletely. Our bloodstream holds less oxygen as a result. It can slow our responses and make us fatigued, which can make us confused.

2. Carbon Dioxide (CO2)

It is the main greenhouse gas produced by human activities such the burning of coal, oil, and natural gas. Natural sources of CO2 include volcanoes, hot springs, and geysers. CO2 is released from carbonate rocks by dissolving in water and acids. A suffocating gas is CO2 (asphyxia: a condition arising when the body is deprived of oxygen, causing unconsciousness or death.). Concentrations of 7% can cause hypoxia, which presents as headache, dizziness, and unconsciousness even when there is enough oxygen present.

3. Chlorofluorocarbons (CFC)

These are gases that are mostly released by refrigeration and air conditioning units. CFCs rise to the stratosphere after being released into the atmosphere, where they combine with a few other gases and weaken the ozone layer, which shields the earth from the sun’s dangerous UV rays.

4. Lead

Among other things, lead can be found in paints, hair dyes, lead batteries, gasoline, diesel, and other products. Lead poisoning can be particularly dangerous for children. It may cause issues with the digestive system, the nervous system, or even cancer in some cases.

Types of Air Pollutants

Particulate Matter (PM)

  • PM10: Particles with diameters that are 10 micrometers and smaller.
  • 5: Fine particles with diameters that are 2.5 micrometers and smaller.

These particles can be made up of various components, including acids (such as nitrates and sulphates), organic chemicals, metals, soil or dust particles, and allergens (such as fragments of pollen or mould spores).

Gaseous Pollutants

  • Carbon Monoxide (CO): A colourless, odourless gas produced by the incomplete combustion of fossil fuels.
  • Sulphur Dioxide (SO2): A gas produced by volcanic eruptions and industrial processes, particularly the burning of coal and oil at power plants and the refining of oil.
  • Nitrogen Oxides (NOx): Gases that include nitrogen dioxide (NO2) and nitric oxide (NO), produced from vehicle emissions, power plants, and off-road equipment.
  • Volatile Organic Compounds (VOCs): Organic chemicals that have a high vapour pressure at ordinary room temperature, such as benzene, toluene, and formaldehyde. They are emitted from certain solids or liquids, like paints and lacquers, cleaning supplies, and gasoline.
  • Ammonia (NH3): A gas emitted from agricultural processes, particularly from livestock waste and fertilisers.

Persistent Organic Pollutants (POPs)

These are organic compounds that are resistant to environmental degradation and include chemicals like polychlorinated biphenyls (PCBs), dioxins, and pesticides.

Heavy Metals

  • Lead (Pb): Once widely used in gasoline and paint, still found in some industrial emissions.
  • Mercury (Hg): Emitted from coal combustion and some industrial processes.
  • Cadmium (Cd) and Arsenic (As): Other toxic metals that can be found in industrial emissions.

Ground-level Ozone (O3)

A secondary pollutant is formed when VOCs and NOx react in the presence of sunlight. Not to be confused with the protective ozone layer in the upper atmosphere.

Secondary Pollutants

  • These are not emitted directly. Rather, they form in the air when primary pollutants react or interact.
  • Ground-level ozone and particulate matter formed from NOx and SO2 are examples of secondary pollutants.

Greenhouse Gases

Although not always considered “pollutants” in the traditional sense because they don’t directly impact human health, greenhouse gases like carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are crucial to the discussion of air pollution due to their impact on climate change.

Radioactive Pollutants

Radon (Rn) and its decay products, and airborne particles from nuclear accidents or detonations.


Biological particles, or bioaerosols, such as bacteria, viruses, fungal spores, or fragments of plant material, can also be considered air pollutants, particularly indoors or in specific workplace settings.

Check Here: Pollution and its Types

Air Pollution Effects

1. Health Issues

Human health is directly impacted by the effects of air pollution. They have been related to a number of cardiovascular and respiratory conditions, including cancer, heart attacks, strokes, emphysema, chronic bronchitis, and asthma. It is estimated that air pollution caused many million deaths, either directly or indirectly.

High levels of air pollution exposure during pregnancy are linked to premature birth, autism, asthma, and early-onset spectrum disorders. Additionally, it may impair a child’s early brain development and result in pneumonia, which claims the lives of about a million children under the age of five every year. Children are more prone to get short-term respiratory infections and pulmonary diseases in areas with air pollution.

2. Global Warming

The current changes that the planet is going through are another direct consequence of global warming. Climate change, habitat loss, relocation, and increasing sea levels from icebergs and melting glaciers have already hinted to an impending crisis if preservation and normalisation measures are not taken swiftly.

3. Acid Rain

When fossil fuels are burned, dangerous substances like sulphur oxides and nitrogen oxides are released into the atmosphere. When it rains, the water droplets react with the airborne pollutants to produce acid, which then falls to the ground as acid rain. The probable effects of acid rain on people, animals, and agriculture.

4. Eutrophication

The phenomenon known as eutrophication occurs when a significant amount of nitrogen, which is present in some pollutants, builds up on the sea surface and converts into algae, harming fish, plants, and other species. The abundance of green algae in lakes and ponds is also caused by the release of this chemical into the atmosphere from industrial sources.

5. Ozone Layer Depletion

The Earth’s stratosphere contains ozone, which shields people from ultraviolet (UV) radiation that are damaging to them. The ozone layer on Earth is deteriorating due to the existence of hydro chlorofluorocarbons and chlorofluorocarbons in the atmosphere. Damaged rays are radiated back to Earth when the ozone layer thinning occurs, perhaps resulting in skin and eye issues. Crops can also be harmed by UV radiation.

Air Pollution Prevention

1. Usage of Public Transport and Carpooling

The amount of pollutants released into the atmosphere and the amount of air pollution can both be decreased by reducing the amount of fuel burned for a person’s transportation needs. Additionally, these options are economically sensible and can contribute to cost savings.

2. Putting the Lights offs when off no use

Most of our electricity is generated through the burning of fossil fuels, which significantly contribute to air pollution. Consequently, using less electricity to prevent air pollution is a good idea.

3. Reusing and Recycling Products

Energy used in creating new versions of products that can be reused is saved by reusing existing ones. Additionally, recycling goods saves energy compared to producing new ones.

4. Avoiding Smoking and Garbage Burning

The burning of trash is a significant source of air pollution. Smoking cigarettes is another factor in air pollution. Prevention of air pollution can be greatly aided by avoiding certain activities and raising awareness of their detrimental effects.

5. Limiting the Usage of Fireworks

Typically, people light off firecrackers to mark special occasions. The ecology is greatly harmed by them because they are known to produce serious air pollution. A great way to help prevent air pollution is to refrain from using firecrackers yourself and to raise awareness of their drawbacks.

What is Air Quality Index?
  • The Air Quality Index (AQI) is a measure of the air quality in a particular location.
  • It is calculated using a formula that takes into account the concentrations of five major air pollutants:
    • Particulate matter (PM10 and PM2.5)
    • Ozone (O3)
    • Nitrogen dioxide (NO2)
    • Sulphur dioxide (SO2)
    • Carbon monoxide (CO)
  • It is recorded by System of Air Quality and Weather Forecasting And Research (SAFAR), an organisation that integrates the measurement of air quality with weather forecasts.

Delhi Air Pollution

India is one of the most polluted nations in the world, and Delhi is likely one of the most polluted capital cities. According to a variety of criteria, Indian cities are mostly included among the top 50 most polluted cities in the world. The introduction of substances into the atmosphere that harm other living things, cause human discomfort, disease, or death, or degrade the natural and built environments is known as air pollution.

Causes of Air Pollution in Delhi

Increasing population and associated development at the expense of causing environmental harm The region’s growth has mostly been unplanned, and industrial facilities that release dangerous chemicals into the air are frequently found near neighborhoods and commercial districts rather than in specially designated regions.

Increased traffic in vehicles (which has not decreased despite the construction of the Delhi metro) and the resulting increase in air and noise pollution. According to the National Environmental Engineering Research Institute, Delhi produces close to 8,000 million tonnes of solid waste every day, but only 5000–5500 million tons of waste is actually removed by the government each day. It only makes the garbage pile up more. The waste from industries, both hazardous and non-hazardous, is not included in this.

Fossil fuels are heavily relied upon, and using them releases a lot of toxic gases into the atmosphere. Increased dust pollution from large-scale construction projects contributes to about 56% of the PM10 and PM2.5 load.

Delhi has higher air pollution than other cities due to its landlocked location. Dust is carried into the area by north-westerly winds that originate in Rajasthan, Pakistan, and occasionally Afghanistan. The air cannot escape because of the Himalayas. As a result, the area becomes polluted and dusty. Due to low-level inversion, this is especially obvious in the winter (upward movement of air from the layers below is stopped).

Delhi is more polluted than Chennai, a coastal city, due to its landlocked topography (where despite high automobile population, has the sea breeze which provides an effective entry and exit for dispersing pollutants).

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Air Pollution in India FAQs

What are main causes of air pollution?

Vehicle emissions, fuel oils and natural gas to heat homes, by-products of manufacturing and power generation, particularly coal-fueled power plants, and fumes from chemical production are the primary sources of human-made air pollution.

What is air pollution and its effects?

Air pollution can directly contaminate the surface of bodies of water and soil. This can kill crops or reduce their yield. It can kill young trees and other plants. Sulfur dioxide and nitrogen oxide particles in the air, can create acid rain when they mix with water and oxygen in the atmosphere.

How can air pollution be prevented?

Air pollution can be prevented by advocating the use of public transport and carpooling. It can also be controlled by avoiding wastage of electricity and practicing reuse and recycling of compatible products.

What is air pollution?

Air pollution is a mixture of solid particles and gases in the air. Car emissions, chemicals from factories, dust, pollen and mold spores may be suspended as particles. Ozone, a gas, is a major part of air pollution in cities. When ozone forms air pollution, it's also called smog. Some air pollutants are poisonous.

What are secondary contaminants?

Secondary contaminants are a class of air pollutants that don’t enter the atmosphere from direct emissions. Instead, they are formed when primary contaminants react with each other.

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