Delhi has once again been ranked the world’s most polluted capital city for the sixth consecutive year, according to the 2024 World Air Quality Report by Swiss air tech company IQAir. 

2024 World Air Quality Report Overview

The 2024 report analyzed data from over 40,000 air quality monitoring stations across 8,954 locations in 138 countries. Key global insights:

• Only 17% of global cities met WHO air quality guidelines.

• 126 out of 138 countries (91.3%) exceeded the PM2.5 guideline of 5 μg/m³.

• Central and South Asia housed the top seven most polluted cities.

• India had six of the top nine most polluted cities.

• In the United States, Los Angeles was the most polluted major city; Ontario, California, was the most polluted overall.

• PM2.5 levels declined in every Southeast Asian country, but challenges remain from El Niño and transboundary haze.

• Africa still lacks infrastructure, with only one monitoring station per 3.7 million people.

Most Polluted Countries in 2024

India, despite having the most cities in the top 100, ranked fifth overall behind:

1. Chad

2. Bangladesh

3. Pakistan

4. Democratic Republic of Congo (DRC)

5. India

6. Reasons:

7. India's expansive monitoring network reduces its national average.

8. Other countries have fewer stations outside high-pollution zones, skewing their averages higher.

Regional Airshed Solutions for South Asia

• Bangladesh, Pakistan, India, and Nepal are among the most polluted globally, with all capitals in the top 10 most polluted cities.

• The report stresses regional cooperation in addressing transboundary air pollution.

• Quote: “Air pollution pays no regard to country borders… Airsheds need to be treated as regional international issues.”

India’s Air Pollution Crisis: A Snapshot

• 13 out of the 20 most polluted cities in the world are located in India.

• Byrnihat, located on the Assam-Meghalaya border, is the world's most polluted city, recording an average PM2.5 concentration of 128.2 μg/m³.

• India ranks as the fifth most polluted country globally, with an average PM2.5 level of 50.6 μg/m³ — 10 times higher than the WHO's annual guideline of 5 μg/m³.

• Although there was a 7% decline in PM2.5 levels from 2023 (54.4 μg/m³), pollution levels remain alarmingly high.

Delhi: A Persistent Pollution Hotspot

• Delhi recorded an annual average PM2.5 concentration of 91.8 μg/m³, maintaining its status as the most polluted capital.

• Some sources also recorded 108.3 μg/m³ in 2024, up from 102.4 μg/m³ in 2023, indicating a worsening trend.

• The National Capital Region (NCR) continues to face high pollution due to: 

  • Vehicular emissions

  • Stubble burning

  • Unfavorable winter meteorological conditions

Most Polluted Cities in India (2024): Northern India Dominates

• 74 of the 100 most polluted cities globally are in India, down from 83 last year.

• Most polluted Indian cities include: 

  • Faridabad, Loni (Ghaziabad), Gurgaon, Greater Noida, Bhiwadi, Noida, Muzaffarnagar, New Delhi (Central Delhi), Delhi (City Average), Ganganagar, Hanumangarh (Rajasthan), Mullanpur (Punjab).

• All 74 cities are in northern India, with 65 located in the Indo-Gangetic Plain (IGP) — a major pollution hotspot.

• The IGP stretches from Punjab to West Bengal and has meteorological conditions that trap pollutants, worsening winter smog.

• India's government plans to coordinate air pollution control across the IGP, covering a population of about 600 million.

Health Impacts of Air Pollution in India

• Average life expectancy in India is reduced by 5.2 years due to long-term pollution exposure.

• A Lancet study (2009-2019) estimated 1.5 million annual deaths in India linked to PM2.5 exposure.

Global Initiatives to Combat Air Pollution

1. WHO Global Air Quality Guidelines: Benchmarks for PM2.5, PM10; support national policies.

2. UN BreatheLife Campaign: Mobilizes cities for clean energy, urban planning, and transport reform.

3. Climate and Clean Air Coalition (CCAC): Targets short-lived climate pollutants like methane and black carbon.

4. EU Clean Air Policy Package: Legally binding pollutant limits; includes Zero Pollution Action Plan (2021).

5. Global Methane Pledge (COP26): Aims to reduce methane emissions by 30% by 2030.

6. World Bank’s PMEH Program: Supports developing nations in integrated air pollution and health policies.

India’s Measures to Tackle Air Pollution

1. National Clean Air Programme (NCAP) – 2019

• Target: 20–30% PM reduction by 2026 in 131+ non-attainment cities.

• Key strategies: 

  • City-specific action plans

  • Expanding monitoring networks

  • Awareness drives

  • Sectoral reforms

2. Commission for Air Quality Management (CAQM) – 2020

• Jurisdiction: Delhi-NCR and surrounding areas

• Measures: 

  • Ban on diesel gensets

  • Emission caps on industries

  • Coordinated stubble burning strategies

3. Graded Response Action Plan (GRAP) – 2017

• Emergency response based on Air Quality Index (AQI) levels: 

  • Construction bans

  • Traffic restrictions

  • Temporary school/industry shutdowns

4. Promotion of Electric Vehicles (EVs)

• FAME-I and FAME-II schemes

• State-level EV policies (e.g., Delhi EV Policy 2020)

5. Bio-Decomposer Solution

• Developed by IARI

• Converts stubble into compost, reducing PM emissions

6. National Electric Bus Program: Promotes electric buses in urban areas to reduce public transport emissions

7. Cleaner Fuel Transition: BS-VI fuel norms rolled out nationally in 2020

8. Urban Forestry – Nagar Van Yojana: Enhancing green cover in cities for pollution mitigation

9. Strengthened Waste Management Rules: Updated rules on solid waste, construction debris, and plastic waste

10. Monitoring Infrastructure Expansion

• Establishing Continuous Ambient Air Quality Monitoring Stations (CAAQMS)

• Using satellite-based monitoring and sensors