Air Pollution In Delhi

The Commission for Air Quality Management (CAQM) has invoked Stage II of the Graded Response Action Plan (GRAP) across Delhi-NCR as the city’s air quality slipped into the “very poor” category.

What Is Air Pollution And How Is It Measured In India?

• Definition: Air pollution is contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere.

• Common Sources of Air Pollution: Household combustion devices, motor vehicles, industrial facilities and forest fires.
• Pollutants of Major Public Health Concern: It include particulate matter, carbon monoxide, ozone, nitrogen dioxide and sulfur dioxide. 
• Measurement – AQI: India uses the Air Quality Index (AQI) framework developed by Central Pollution Control Board (CPCB) in 2014, measuring eight major pollutants (PM₂.₅, PM₁₀, NO₂, SO₂, CO, O₃, NH₃ and Lead) and converting them into a scale (0-500) where higher values indicate worse air quality. 

About Graded Response Action Plan (GRAP)

• It is a statutory framework that specifies stage-wise measures to be implemented to combat deteriorating air quality in the National Capital Region. It provides predefined actions based on the Air Quality Index (AQI) levels.

• • It was formulated by the Environment Pollution (Prevention & Control) Authority (EPCA)
• Enforcement Authority: Commission for Air Quality Management (CAQM) in NCR and adjoining areas oversees implementation of GRAP.
• GRAP is divided into four stages corresponding to AQI levels:
  • Stage 1: Poor category (AQI 201 to 300).
  • Stage 2: Very poor category (AQI 301-400).
  • Stage 3: Severe category (AQI 401-450). 
  • Stage 4: Severe + category (AQI 451+).
• GRAP Stage II involves a 12-point action plan, key actions includes: 
  • Sweeping and watering of roads daily.
  • Enforcement of dust control measures at Construction and Demolition (C&D) sites strictly.
  • Controlling air pollution in hotspot areas of the city.
  • Providing uninterrupted power supply to reduce usage of diesel generators.
  • Coordinating traffic movements to facilitate smooth traffic flow and reduce vehicular emissions.
  • Alerting the public about air pollution levels through mass media. It also involves giving suggestions and guidelines.
  • To discourage private vehicles, increasing parking fees.
  • Expanding CNG or electric bus and metro services by increasing the frequency.
  • To discourage the open burning of biomass and municipal solid, electric heaters have to be provided to security staff.

Factors Behind Delhi’s Persistent Air Quality Crisis

• Air Pollutants:
  • Stubble Burning: Farmers of the states around Delhi carry out stubble burning to prepare the field for their next crop. 
    • It emits toxic pollutants in the atmosphere containing harmful gases like Carbon Monoxide (CO), methane (CH4), and volatile organic compounds (VOC).
    • The Union government reported that stubble burning contributed an average 10.6% to Delhi’s PM₂.₅ between early October and  December last year (with peaks up to 35% on some high-smoke days).
  • Vehicular Emissions: Emissions from vehicles cause hazardous effects of air pollution and smog. Delhi’s registered vehicular population has reached to nearly three times to 7.6 million from 2.2 million in 1994, registering a growth rate of 14% per annum
    • According to data presented by Centre for Science and Environment (CSE), local pollution sources in Delhi account for 30.34 per cent of the city’s air pollution (50.1 per cent of which is contributed through transportation)
  • Construction Dust: Increase in construction and other infrastructure work in the region has led to generation of construction dust, which acts as a pollutant.
    • According to the Delhi Pollution Control Committee (DPCC), construction-and-demolition dust is explicitly identified as a “major source of PM₁₀ and PM₂.₅ emissions in ambient air” in Delhi.
  • Industrial Pollution: Industries located in Delhi-NCR have failed to adopt environment friendly fuels and techniques. They emit gases which cause pollution.
    • Aironomics 2025 report shows that Industries contribute around 22% of the annual PM2.5 load
  • Firecrackers: During the winter months when pollution levels are at the peak, the bursting of firecrackers during festivals adds to the already existing pollution load.
  • Landfill fires: The burning of municipal solid waste, both at landfill sites and other areas further contribute to pollution.
• Weather Conditions:
  • Stagnant Winds: Due to stagnant winds during winter, the pollutants generated in the area get trapped over the region. This increases the chances of pollution to a great extent.
  • Low Air Inversion: During winter months, the upward movement of air from the layers below is stopped. This causes polluted air to be stagnant over the region.
  • Weather Diversity: India’s diverse climatic zones and variable atmospheric conditions complicate the modeling and standardization of source apportionment across regions
• Geographical Reason:
  • Delhi is land-locked from all sides. The north-westerly winds coming from Pakistan and Afghanistan bring in large amounts of dust particles to the region. 
  • Due to the presence of Himalayas, which block the escape route of the air, the dust and pollutants settle in the region.
• Administrative Reasons:
  • Less Focus on Public Transport: There has been very less focus on public transport as an alternative mode of transport. 
    • Till March 31, 2023, Delhi had 79.5 lakh vehicles, of which 20.7 lakh were private cars.

Impact of Air Pollution

• Health impacts: Exposure to elevated PM₂.₅ levels is linked with respiratory diseases, cardiovascular issues and premature mortality
  • Continuous exposure to poor quality air can lead to development of bronchitis. It can cause cough, breathlessness, and wheezing in people.
  • Epidemiological studies have shown that exposure to poor air quality can hamper natural growth of babies.
• Vulnerable groups: Children, older adults, pregnant women and those with pre-existing conditions suffer disproportionately. 
  • Air pollution was responsible for 7.9 million premature deaths in 2023, accounting for roughly one in eight deaths globally.
• Economic & Social Costs: Poor air quality leads to higher healthcare expenditure, lower workforce productivity, school closures and transport disruptions  cumulatively imposing a major burden on the economy
  • Several studies have tried to quantify the damage, One by the global consultancy firm Dalberg concluded that in 2019, air pollution cost Indian businesses $95 billion due to “reduced productivity, work absences and premature death”
• Vegetation Growth: Studies have shown that poor quality of air can damage crops and trees in a variety of ways. This will affect growth of greenery and also food security.
• Air Traffic: Air pollutants react with sunlight to produce haze. The combination of high pollution, humidity, and calm winds led to a drastic drop in visibility, making it difficult for planes to land and take off.

Effective Measures to Tackle Delhi’s Persistent Air Pollution Crisis

• Control Stubble Burning: To control stubble burning, farmers are subsidized to use farm machinery that reduces the need to burn stubble. 
  • Fines have been imposed for stubble burning. In addition, new techniques to speed up the process of decomposition of farm stubble have been promoted.

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• Graded Response Action Plan (GRAP): The Commission for Air Quality Management (CAQM) invoked Stage-II of the Graded Response Action Plan (GRAP) for the Delhi-NCR region as AQI rose into the “Very Poor” range, directing Stage-II actions to be enforced immediately.
• Dust-suppression: The plan expanded on dust control by committing additional hardware, Delhi increased anti-smog infrastructure to 376 anti-smog guns, 266 water sprinklers and 91 mechanised road sweepers this season and deployed multi-agency teams to patrol construction hotspots
• Vehicular-enforcement: Enforcement intensified with ~5.95 lakh PUC challans issued till August 2025 and stepped-up road checks (over 10.8 lakh NDVs checked), while authorities announced tighter commercial-vehicle entry norms (BS-VI/CNG/EV preference and stricter vehicle checks).
• National Clean Air Programme (NCAP): It was launched by the Ministry of Environment, Forest and Climate Change (MoEF&CC) in January 2019 with the objective of improving air quality in 131 non-attainment and Million Plus Cities/Urban Agglomerations across 24 States/UTs, by engaging all relevant stakeholders.
  • NCAP aims for a reduction of 20-30% in PM10 concentrations by 2024-25 compared to the baseline year of 2017-18. 
  • The target has been revised to achieve up to a 40% reduction in PM10 levels or to meet national standards (60 µg/m³) by 2025-26.
• Commission for Air Quality Management (CAQM): CAQM is a statutory body formed under the Commission for Air Quality Management in National Capital Region and Adjoining Areas, Act 2021. 
  • CAQM has provided a framework to tackle the problem of air pollution due to stubble burning.
• Peripheral Road: The construction of western and eastern peripheral highways allowed large commercials to bypass Delhi, thereby reducing pollution burden.

• Electric Vehicles Promotion: The government is making efforts to promote electric vehicles as an alternative to fossil fuel vehicles. 
• Cloud Seeding: Delhi authorities and IIT Kanpur carried out a trial cloud-seeding operation, releasing silver iodide and sodium chloride from aircraft over Burari and Khekra to induce artificial rain.

Way Forward – Mitigation Roadmap 

• Source-Control: Reduce emissions from vehicles, industry, and construction on a year-round basis. 
• Despite fewer stubble-burning events in Oct 2025 (175 events vs 779 in 2024), Delhi PM2.5 only dropped 15.5%, highlighting the need for structural pollution control beyond agriculture.
• Public-Transport & EVs: Expand metro, bus, and suburban transit while incentivising electric vehicle adoption. 
  • The proposed EV Policy 2.0 aims to phase out petrol, diesel, and CNG-powered two- and three-wheelers by 2026 to curb pollution and promote electric mobility in the capital.
• Establishing a National Research Center: Its role would be to conduct standardized source apportionment studies annually will improve methodological consistency and generate high-quality, region-specific data to guide interventions.
• Incentive for Civil Society: Different stakeholders need to be aware about the positive impacts of  cleaning the air which  will benefit their livelihoods and businesses.
  • For Example: Farmers will not curb stubble burning until a viable circular economy for alternative uses of biomass emerges. 
  • We must adopt sustainable lifestyles which are in line with the government’s LiFE initiative.
• Publishing an Annual Report:  Report on key polluting sources will enable systematic tracking of major emission contributors, supporting data-driven air quality policies and public transparency.
• Integrating technologies like satellite imaging and AI for real-time pollution tracking, along with adopting best practices from international models (e.g., EU’s PMF4 and SHERPA5 ), will improve precision in source apportionment and air quality management policies
  • Air Quality Forecasting: Use real-time SAFAR/IMD data to issue early warnings and enable pre-emptive measures, e.g., regulating traffic, halting construction, and adjusting industrial operations. AI-enabled dashboards improve transparency and coordination.
• Construction & Dust Management: Year-round dust suppression, mechanised sweeping, roadside greening, water sprinklers, and strict monitoring of construction/demolition sites must continue beyond winter. 
• Green Infrastructure: Expand urban green belts, parks, rooftop gardens, and tree plantation drives.
  • Public participation, like “Harit Ratna” awards for environment-friendly practices, encourages sustainable lifestyles and pollution absorption.

• Policy & Accountability: Enforce GRAP, NCAP targets, vehicular emission norms (BS-VI/EVs), and industrial CEMS monitoring. 
  • Departments must report to Green War Room dashboards and maintain citizen grievance redressal via 311/Green Delhi apps.

Conclusion

Air pollution is a big menace for the society, especially in a city like Delhi, which faces this issue annually. It is therefore necessary to carry out steps that provide a long-term solution to this problem.