Air Pollution in India: Causes, Effects, AQI and Solutions Explained

How Air Quality is Measured ?

• The National Air Quality Index (AQI) monitors air quality in urban centers in real time to enhance public awareness and drive mitigation efforts.
• AQI simpl ifies complex air quality data into a single numerical index, categorized using color codes.
• It measures eight pollutants: PM10, PM2.5, NO2, SO2, CO, O3, NH3, and Pb. The highest sub-index determines the overall AQI score.

Impact of Pollution

• Economic Cost : Pollution-related health care expenses and productivity losses account for 8.5% of India's GDP (World Bank).
• Health Cost : Air pollution caused 1.1 million premature deaths in India in 2017 (Lancet Commission).
• Environmental Cost : Increased GHG emissions, rising sea levels (1.8 mm per year), acid rain, ozone layer depletion, and eutrophication.
• Political Impact : Public dissatisfaction is rising, leading to movements like the Urban Chipko Movement against tree-cutting for infrastructure projects.

Air Pollution in Northern India

• India ranks 178 out of 180 in air quality (Environmental Performance Index 2018).
• Annual PM2.5 levels (90 μg/m3) are more than twice India's standard (40 μg/m3) and nine times the WHO limit (10 μg/m3).
• India accounts for 26% of global premature deaths due to air pollution.
• Major NOx hotspots: Delhi-NCR, Sonbhadra (UP), Singrauli (MP), Talcher-Angul (Odisha).
• In November 2019, Delhi declared a public health emergency as AQI exceeded 500 in multiple locations.
• Pollution levels in Delhi are 40% to 80% higher in winter than in other seasons.

Key Sources of Air Pollution in Delhi

1. Vehicular Pollution : Vehicles contribute 28% of PM2.5 emissions; total vehicles in Delhi increased from 4.24 million (2004) to 10.8 million (2018).
2. Stubble Burning : A primary cause of winter pollution due to burning of crop residue in neighboring states.
3. Industrial Pollution : Contributes 30% of PM2.5 levels, including 14% from small industries.
   • India is the second-largest coal burner after China.
   • Sulfur dioxide (SO2) from power plants is transported to Delhi by northwesterly winds.
     
4. Construction Dust : A significant contributor to particulate matter levels.
5. Geographical & Meteorological Factors : Lack of winds, late monsoon withdrawal, and dust storms worsen pollution.

Stubble Burning – Causes and Policy Responses

• Mechanized harvesting leaves stubble behind, preventing wheat sowing. Burning is a fast, cheap solution.
• Punjab Preservation of Subsoil Water Act (2009) delayed paddy transplantation, coinciding burning with winter.
• Policy responses :
  • Bans on crop residue burning (NGT & Environmental Protection Acts).
  • National Policy for Management of Crop Residue (NPMCR) 2014.
  • Central Sector Scheme (2018-2020) subsidizing machinery for crop residue management.
  • State-imposed fines & incentives (Punjab & Haryana offer ₹2,500 per acre bonus to stop burning).
  • Alternative uses of stubble: Cattle feed, compost, biomass energy, ethanol production.

Steps Taken to Curb Air Pollution

1. Graded Response Action Plan (GRAP)
   • Implements tiered restrictions based on AQI severity. E.g., bans diesel generators, increases parking fees.
2. National Clean Air Programme (NCAP)
   • Targets 20-30% reduction in PM levels by 2024 (base year: 2017).
   • Expands PM2.5 monitoring infrastructure and manual stations from 684 to 1,000.
3. Vehicular Emission Control
   • Green Budget (2018) : 26 programs for pollution reduction.
   • Shift to CNG for commercial vehicles.
   • Bharat Stage-VI (BS-VI) norms: Delhi became the first Indian city to run on BS-VI fuels (2018).
4. Industrial & Power Plant Regulations
   • Environmental norms for PM10, SO2, NOx reduction.
   • Pradhan Mantri Ujjwala Yojana (PMUY): Promotes clean cooking fuels (LPG, biogas, solar).
   • Ban on pet coke & furnace oil in Haryana, Rajasthan, and UP.
5. Emerging Solutions
   • Smog Towers : Purifies air in 10 km radius, removes PM2.5 and PM10 pollutants.
     
   • Hydrogen Fuel Cells: Zero-emission alternative to fossil fuels, though still under testing.

Challenges in Pollution Control

• Lack of coordination : Pollution control is divided among 16 agencies across central, state, and municipal levels.
• Regional Problem : Delhi’s pollution spreads across neighboring states, requiring a regional action plan.
• Inconsistent Source Identification : Pollution studies give varying contributions from different sources.
• Insufficient Infrastructure : Delhi Pollution Control Committee (DPCC) has been understaffed since 1990.

Way Forward – Policy Suggestions

1. NITI Aayog’s ‘Breathe India’ Report
   • Electrification of public transport (taxis, 3-wheelers).
   • Feebate System : Higher taxes on polluting vehicles, incentives for clean vehicles.
   • Scrappage policy : Encourage replacement of old vehicles.
   • Optimize power sector : Shift to renewables, upgrade old thermal plants, use cleaner coal.
   • Improve industrial audits : Shift from self-audits to third-party verification.
   • Implement emissions trading : Market-based approach using the polluter-pays principle.
2. Regional Approach to Pollution Control
   • Air pollution is a regional issue, requiring an airshed-based approach beyond city/state boundaries.
   • China’s Example : Beijing adopted unified planning, monitoring, and alerting across multiple regions.
3. Public Engagement & Monitoring
   • Behavioral change campaigns : Promote eco-friendly transport & waste management.
   • Improved monitoring systems : Use satellite data (Sentinel 5-P) to track pollution patterns.
   • India faces severe air pollution challenges, especially in North India.
   • Government measures have shown partial success, but long-term solutions require regional cooperation.
   • A multi-pronged approach involving policy, technology, economic incentives, and public participation is needed to tackle air pollution effectively.
     

Climate and Clean Air Coalition (CCAC) launched an AQMX in the backdrop of International Day of Clean Air for Blue Skies (7 September).

• Led by UN Environment Programme (UNEP), this year’s theme focuses on ‘Invest in Clean Air Now’.

About Air Quality Management Exchange Platform (AQMx)

• It is a one-stop-shop that provides the latest air quality management guidance and tools proposed to meet WHO Air Quality Guidelines interim targets.
• It is a component of CCAC Clean Air Flagship and contributes to implementation of UNEA-6 Resolution to increase regional cooperation and action on improving air quality globally.

Need of Air Quality Management Exchange Platform (AQMx)

• Menace of air pollution : Causes more than 8 million premature deaths annually, particularly affecting poor and vulnerable.
• Capacity gaps : AQMx helps to address air quality management capacity gaps with curated guidance on air quality monitoring, health impact assessments etc.
• Knowledge sharing : Allow regional and sub-regional communities to exchange knowledge about air quality management best practices.

The Climate and Clean Air Coalition (CCAC) 

• Founded in 2012, and convened within UNEP, CCAC is a voluntary partnership of more than 160 governments, intergovernmental organizations, and NGOs. India joined CCAC in 2019.
• It works to reduce powerful but short-lived climate pollutants– methane, black carbon, hydrofluorocarbons (HFCs), and tropospheric ozone – that drive both climate change and air pollution.
• Aerobiology is the study of the movement and impact of airborne biological particles, or bioaerosols, on human, animal, and plant health. Bioaerosols include:
  • Bacteria, fungal spores, pollen grains, viruses, etc.
    
• Bioaerosols reflect changes in biodiversity, plant flowering patterns, and distribution, all sensitive to climate shifts.
  • Hence, new technologies are needed to improve understanding of Bioaerosols which would further enhance forecasting and climate change impact assessments.
• New observational techniques: Such as high-resolution image analysis, holography, multi-band scatterometry, fluorescence spectrometry and nanotechnology for DNA sequencing.

India’s first ‘teal carbon’ study undertaken at Keoladeo National Park (KNP).

• The study depicted the potential of teal carbon as a tool to mitigate climate change, if the anthropogenic pollution in the wetlands can be controlled.
• Study also reveals elevated methane emissions can be reduced by use of a specialized type of biochar, which is a form of charcoal.

Teal Carbon

• Teal carbon refers to carbon stored in non-tidal freshwater wetlands, encompassing carbon sequestered in vegetation, microbial biomass, and dissolved and particulate organic matter.
• Teal carbon, being a color-based terminology (refer infographics), reflects the classification of the organic carbon based on its functions and location rather than its physical properties.
• In contrast, black and brown carbon are produced by incomplete combustion of organic matter and contribute to global warming.
• Significance: It contributes to an increase in the ground water level, flood mitigation and heat island reduction, supporting a sustainable urban adaptation.

Keoladeo National Park (Bharatpur, Rajasthan)

• Declared a national park in 1982 and a UNESCO World Heritage Site in 1985.
• Home to over 370 species of birds and animals like pythons, Siberian cranes etc.
• Placed on the Montreux Record (Ramsar Convention) in 1990 due to "water shortage and an unbalanced grazing regime”.