Delhi was ranked the world’s fourth most-polluted metropolis —and probably the most polluted capital — in 2025, recording an annual common nice particulate matter (PM2.5) degree of 99.6µg/m³, practically 20 instances the World Well being Group’s protected restrict, in accordance with a report launched on Tuesday. India accounted for 3 of the 5 most-polluted cities globally and 29 of the highest 50.
In accordance with the annual World Air High quality Report 2025, launched by Swiss air high quality know-how agency IQAir, Loni in Uttar Pradesh, with an annual common PM2.5 degree of 112.5µg/m³, was the world’s most polluted metropolis, adopted by Hotan in China (109.6µg/m³) and Byrnihat in Meghalaya (101.6µg/m³).
“Loni, in India, was probably the most polluted metropolis, recording an annual common PM2.5 focus of 112.5µg/m³—an almost 23% enhance from 2024 and greater than 22 instances the WHO guideline. The world’s 25 most polluted cities had been all in India, Pakistan and China, with India residence to 3 of the 4 most polluted,” the report stated.
The report made a distinction between the smaller “New Delhi” capital space and “Delhi” as a complete, discovering New Delhi (82.2µg/m³) to be the world’s most polluted capital metropolis once more, adopted by Dhaka (68µg/m³) in Bangladesh and Dushanbe (57.3µg/m³) in Tajikistan. In 2024, Delhi had an annual PM2.5 common of 108.3µg/m³, whereas New Delhi’s common was 91.8µg/m³, indicating marginal enchancment.
India’s personal “protected” restrict for PM2.5 stays considerably increased at 40µg/m³, in contrast with WHO guideline of 5µg/m³.
In accordance with the report, India ranked because the sixth most polluted nation, with a median PM2.5 degree of 48.9µg/m³. Probably the most polluted 5 had been Pakistan (67.3µg/m³), Bangladesh (66.1µg/m³), Tajikistan (57.3µg/m³), Chad (53.6µg/m³) and the Democratic Republic of the Congo (50.2µg/m³).
In 2024, India was ranked fifth globally, with a median of fifty.6µg/m3.
“In 2025, India’s nationwide common PM2.5 ranges noticed a modest 3% decline, dropping from 50.6µg/m³ in 2024 to 48.9µg/m³. Whereas Delhi’s annual common focus fell by 8%, town nonetheless grappled with extreme month-to-month spikes pushed by seasonal smog and dirt storms,” the report learn.
Manoj Kumar, an analyst on the Centre for Analysis on Power and Clear Air (CREA) raised concern over 115 Indian cities exceeding even India’s “lenient” air high quality requirements.
“Delhi being ranked the world’s most polluted capital in IQAir’s PM2.5 information reveals the dimensions of the issue. A good portion of this particulate air pollution is from gaseous pollution, and except CAQM regulates these on the supply, we’re solely addressing half the issue. Plenty of Indian cities with exceedingly excessive ranges additionally proceed to stay outdoors the scope of Nationwide Clear Air Programme (NCAP),” he stated.
Different cities within the Nationwide Capital Area (NCR) additionally fared poorly. Ghaziabad (89.2 µg/m³) ranked seventh globally, Noida (80.5 µg/m³) 18th, Higher Noida (77.2 µg/m³) twenty first, and Gurugram (74.6 µg/m³) twenty third.
The IQAir report is predicated on international information for PM2.5, that are ultrafine inhalable particles having a diameter lower than 2.5 micrometres, and included information from 9,446 cities throughout 143 nations. The report added 12 nations and territories that weren’t included within the earlier version.
The report, in its eighth version, discovered that solely 14% of worldwide cities met the WHO requirements, which was a lower from 17% the earlier yr.
Solely 13 nations met the WHO requirements—French Polynesia, Puerto Rico, U.S. Virgin Islands, Barbados, New Caledonia, Iceland, Bermuda, Réunion, Andorra, Australia, Grenada, Panama and Estonia.
“Air high quality is a fragile asset that requires energetic stewardship to guard public well being,” stated IQAir World CEO Frank Hammes.
“The 2025 World Air High quality Report makes clear that with out monitoring, we can not totally perceive what’s within the air we breathe. Increasing entry to real-time information empowers communities to behave. By decreasing emissions and addressing local weather change, we are able to drive significant, lasting enhancements in international air high quality,” he stated.
