World Air Quality Report 2024

In March 2025, the 7th annual World Air Quality Report 2024 has been recently released by IQAir highlighting alarming trends of the world’s most polluted countries, territories, and regions.

IQAir is a Swiss company specializing in air quality monitoring and purification solutions.

Key Highlights of the Report

Data Source: The report is based on data collected from over 40,000 air quality monitoring stations in 138 countries, territories, and regions.
Global Findings: Only 17% of global cities meet the World Health Organization’s (WHO) air pollution guidelines.
Cleanest Countries: Seven countries met the WHO annual average PM2.5 guideline of 5 µg/m³, including Australia, the Bahamas, Barbados, Estonia, Grenada, Iceland, and New Zealand.
Polluted Countries: A staggering 126 (91.3%) of the 138 countries and regions exceeded the WHO annual PM2.5 guideline of 5 µg/m³.

Most Polluted Countries in 2024

Chad (91.8 µg/m³): More than 18 times higher than the WHO PM2.5 annual guideline.
Bangladesh (78.0 µg/m³): More than 15 times higher than the WHO PM2.5 annual guideline.
Pakistan (73.7 µg/m³): More than 14 times higher than the WHO PM2.5 annual guideline.
Democratic Republic of the Congo (58.2 µg/m³): More than 11 times higher than the WHO PM2.5 annual guideline.
India (50.6 µg/m³): More than 10 times higher than the WHO PM2.5 annual guideline.

Most Polluted Metropolitan Areas

Most Polluted: Byrnihat, India (Assam-Meghalaya border) – with an annual average PM2.5 concentration of 128.2 µg/m³.
Cleanest: Mayaguez, Puerto Rico – with an annual average PM2.5 concentration of 1.1 µg/m³.

Most Polluted Capital City

Delhi, India remains the world’s most polluted capital city with an average PM2.5 concentration of 91.8 µg/m³.

Region-wise Air Quality

Polluted Region: Central & South Asia, home to the top seven most polluted cities in the world.
Cleanest Region: Oceania, where 57% of regional cities meet the WHO PM2.5 annual guideline value of 5 µg/m³.

Air Pollution in India

Pollution Rank: India ranks as the fifth most polluted country, a slight improvement from third place in 2023.
Decline in Pollution: India experienced a 7% reduction in PM2.5 concentrations, averaging 50.6 µg/m³ in 2024 compared to 54.4 µg/m³ in 2023. However, this is still 10 times higher than the WHO’s annual guideline value of 5 µg/m³.
Polluted Cities: India is home to six of the world’s ten most polluted cities and 13 of the 20 most polluted cities. Key cities include Byrnihat, Faridabad, Multanpur, Loni (Ghaziabad), Gurgaon, Greater Noida, Bhiwadi, Noida, Muzaffarnagar, and New Delhi.
Capital City: New Delhi’s pollution level showed a slight decrease to an annual average of 91.6 µg/m³ in 2024, down from 92.7 µg/m³ in 2023.
Health Impact: Air pollution continues to be a major health issue in India, reducing life expectancy by an estimated 5.2 years.