World's Most Polluted City (2022 WHO Data): Delhi, India

According to the World Health Organization's 2022 ambient air quality database, Delhi, India recorded the highest annual average PM2.5 concentration among major global cities.

Key Metric

• Pollutant: PM2.5 (fine particulate matter ≤2.5 μm)
• Delhi 2022 Annual Mean: ~92–100 µg/m³ (WHO guideline: 5 µg/m³)
• Exceedance: 18–20× WHO safe level

Why Delhi?

• Vehicle emissions (12M+ vehicles)
• Biomass burning (cooking, heating, crop residue in Punjab/Haryana)
• Industrial emissions, construction dust
• Winter temperature inversion traps pollution
• Geography: landlocked, low wind speeds

Other Highly Polluted Cities (2022)

Lahore (Pakistan), Dhaka (Bangladesh), Baghdad (Iraq), Hotan (China), Peshawar (Pakistan), Bhiwadi (India), Ghaziabad (India), Noida (India), New Delhi (distinct from Delhi NCT).

Health Impact

PM2.5 penetrates lungs, enters bloodstream → cardiovascular/respiratory disease, lung cancer, cognitive decline, reduced life expectancy (estimated 10+ years lost for Delhi residents per AQLI).

Efforts

Graded Response Action Plan (GRAP), odd-even vehicle rationing, BS-VI fuel, electric bus push, stubble management subsidies — but enforcement and regional coordination remain weak.

Real-time AQI: aqicn.org/city/delhi, IQAir.