Delhi Tops List Of World's Most Polluted Capital Cities — Check Top 10 Names Here

Delhi continues to top the list of the world's most polluted capital cities for a sixth straight year, with an alarming average PM2.5 concentration of 91.8 µg/m³, according to the World Air Quality Report 2024. On the other hand, India ranked fifth among the most polluted countries in the world.

The report, released by Swiss firm IQAir, analyses global air quality trends, throwing light on the persistent air pollution crisis gripping various regions worldwide.

The World Air Quality Report 2024 assessed PM2.5 levels in 8,954 cities across 138 countries, relying on data from over 40,000 regulatory air monitoring stations and low-cost sensors. PM2.5, the fine particulate matter measuring less than 2.5 microns in diameter, is a major air pollutant linked to severe health risks, including respiratory and cardiovascular diseases.

New Delhi’s PM2.5 levels far exceed the World Health Organization’s (WHO) recommended safe limit of 5 µg/m³. Despite various pollution control measures, the capital remains plagued by emissions from vehicular traffic, industrial activities, crop burning in neighbouring states and adverse meteorological conditions that trap pollutants.

Following New Delhi in the ranking is N'Djamena, Chad, with a PM2.5 concentration of 91.6 µg/m³, while Dhaka in Bangladesh, takes the third spot at 78.0 µg/m³.

According to the report, the following capital cities had the highest PM2.5 levels in 2024:

• New Delhi, India – 91.8 µg/m³

• N’Djamena, Chad – 91.6 µg/m³

• Dhaka, Bangladesh – 78 µg/m³

• Kinshasa, D.R. Congo – 58.2 µg/m³

• Islamabad, Pakistan – 52.4 µg/m³

• Dushanbe, Tajikistan – 46.3 µg/m³

• Hanoi, Vietnam – 45.4 µg/m³

• Kathmandu, Nepal – 45.1 µg/m³

• Abuja, Nigeria – 42.2 µg/m³

• Jakarta, Indonesia – 41.7 µg/m³

At the other end of the spectrum, some of the least polluted capital cities in the world include Nassau in Bahamas, San Juan in Puerto Rico and Papeete in French Polynesia.

Here are the least polluted cities in the world:

• Nassau, Bahamas – 2.3 µg/m³

• San Juan, Puerto Rico – 2.6 µg/m³

• Papeete, French Polynesia – 2.8 µg/m³

• Bridgetown, Barbados – 3.1 µg/m³

• Reykjavik, Iceland – 3.8 µg/m³

• Canberra, Australia – 3.9 µg/m³

• Wellington, New Zealand – 4.3 µg/m³

• Tallinn, Estonia – 4.3 µg/m³

• Brasilia, Brazil – 5.2 µg/m³

• Stockholm, Sweden – 5.3 µg/m³

India, as a whole, continues to face severe air quality issues, with a population-weighted PM2.5 average of 50.6 µg/m³. This reinforces the urgent need for stricter pollution controls, improved public transportation and sustainable industrial practices to curb rising pollution levels.