India has 5 of world's 10 most polluted cities, Loni in UP tops with alarming PM 2.5 levels: Global air quality report
The 2025 IQAir World Air Quality Report reveals PM2.5 data from 9,446 cities across 143 countries. Five Indian cities and four from Pakistan are in the top 10 for highest pollution levels.
INDIA'S Loni secured the top spot among the world's most polluted cities with alarming *PM 2.5 levels, according to IQAir report released on 24 March. As per the recommended World Health Organisation PM 2.5 levels, the concentration of this hazardous air pollutant less than 5 micrograms per cubic metre last year. This implies that Loni's PM 2.5 level is almost 22 times the prescribed limit.
*Particulate Matter
A total of 5 Indian cities secured a spot in the top 10 list of most polluted cities across the world, including Uttar Pradesh's Loni and Meghalaya's Byrnihat, followed by Delhi, Ghaziabad and West Bengal's Ula (Birnagar). The second spot in the list is occupied by China's Hotan. Pakistan's 4 cities also take a spot in the “World's most polluted cities” list.
PM 2.5 concentrations in the world's most polluted cities
Loni, UP – rank 1 - 112.5
Byrnihat, Meghalaya – rank 3 – 101.1
Delhi – rank 4 – 99.6
Ghaziabad – rank 5 – 89.2
Ula, West Bengal – rank 10 – 86.8
The 2025 IQAir World Air Quality Report presents “PM2.5 air quality data sourced from 9,446 cities spanning 143 countries, regions, and territories.
The information is sourced from more than 40,000 regulatory monitoring stations and low-cost sensors, managed by a wide array of contributors.” The information about air quality has been obtained from government agencies, universities, non-profit organisations, private enterprises, and engaged citizen scientists around the world.
World's most polluted country
Moreover, Pakistan secured the top spot among the world's most polluted countries in 2025, with concentrations of PM2.5 up to 13 times higher than the recommended World Health Organization level.
Key findings from the 2025 World Air Quality Report:
In 2024, 17% of global cities met the World Health Organization (WHO) annual PM2.5 guideline of 5 µg/m³ but this figure deteriorated in 2025 with only 14% of global cities meeting the standard.
Only 13 countries meet the WHO annual average PM 2.5 guideline — French Polynesia, Puerto Rico, U.S. Virgin Islands, Barbados, New Caledonia, Iceland, Bermuda, Réunion, Andorra, Australia, Grenada, Panama and Estonia.
A total 130 out of 143 countries, almost 91%, exceeded the WHO annual average PM 2.5 guideline value.
“The five most polluted countries were Pakistan (67.3 µg/m³), Bangladesh (66.1 µg/m³), Tajikistan (57.3 µg/m³), Chad (53.6 µg/m³) and the Democratic Republic of the Congo (50.2 µg/m³),” the Swiss air quality monitoring firm IQAir said.
