World's Most Polluted Cities

Air Quality Report Based on PM2.5 Concentrations

The world's most polluted cities are typically ranked by annual average concentrations of fine particulate matter (PM2.5), which is a key health hazard. Rankings can shift yearly due to weather, economic activity, and policy changes.

According to IQAir's 2023 World Air Quality Report, which tracks PM2.5 levels in cities across 134 countries, here are the most polluted urban areas.

Top 10 Most Polluted Cities in 2023

1. Begusarai, India 118.9 µg/m³

2. Lahore, Pakistan 99.5 µg/m³

3. Delhi, India 92.7 µg/m³

4. Peshawar, Pakistan 91.8 µg/m³

5. Muzaffarnagar, India 89.1 µg/m³

6. Kolkata, India 89.0 µg/m³

7. Patna, India 84.5 µg/m³

8. Karachi, Pakistan 84.2 µg/m³

9. Darbhanga, India 81.5 µg/m³

10. Kishtwar, India 81.4 µg/m³

Key Finding from 2023 Data

South Asia is overwhelmingly dominant in pollution rankings. In 2023, 99 of the world's 100 most polluted cities were in Asia, with 83 of those located in India alone.

The World Health Organization (WHO) recommends that annual average PM2.5 concentrations should not exceed 5 µg/m³. All cities in this list exceed that guideline by more than 16 times.

Key Regional Patterns

South Asia

Cities in India, Pakistan, and Bangladesh consistently dominate the list. Industrial activity, vehicle emissions, agricultural burning, and geographic factors contribute to severe air quality issues.

Southeast Asia

Cities like Jakarta (Indonesia) and Hanoi (Vietnam) often rank highly due to traffic congestion, coal power plants, and agricultural burning practices.

East Asia

Cities in China have shown significant improvement over the past decade due to strict environmental policies. While still facing challenges, no Chinese city appeared in the top 100 most polluted in 2023.

Africa

Data is limited, but cities like Lagos (Nigeria) and Greater Accra (Ghana) face severe pollution from vehicle emissions, industrial activity, and waste burning.

Primary Sources of Pollution

Vehicle Emissions

Particularly from diesel engines

Industrial Emissions

Especially from coal-fired power plants

Agricultural Burning

Seasonal crop residue burning

Construction & Road Dust

Unpaved roads and construction sites

Household Burning

Coal, wood, or kerosene for cooking/heating

Geographic Factors

Valleys and weather patterns that trap pollution

Important Notes on Pollution Rankings

Metric Used: These rankings are based on PM2.5 concentrations. Some cities may have different rankings for other pollutants like nitrogen dioxide (NO₂) or ozone (O₃).

Data Coverage: Rankings include only cities with active monitoring stations. Many highly polluted cities in Africa, the Middle East, and South America lack public data and are underrepresented.

Seasonal Variations: Pollution often spikes in winter in South Asia due to agricultural burning, increased heating needs, and unfavorable weather conditions that trap pollutants.

Temporal Changes: A city's rank can change dramatically from year to year based on specific conditions. Long-term trends are more informative than a single year's ranking.

For current live data and updated rankings, refer to: IQAir AirVisual platform and World Air Quality Index (WAQI) project

Data source: IQAir World Air Quality Report 2023