Published: 12 April 2026 | Author: Team JanVayu | Reading time: 4 min
On March 24, 2026, IQAir released its eighth annual World Air Quality Report, a global assessment of PM2.5 pollution covering 9,446 cities across 143 countries. For India the picture is mixed. The national average eased and Delhi's annual figure fell, but some cities, Loni and Ghaziabad among them, got worse.
Loni is now the most polluted city on Earth
The city of Loni in Uttar Pradesh recorded an annual average PM2.5 concentration of 112.5 micrograms per cubic metre in 2025. That is a 23% increase from the previous year and more than 22 times the WHO annual guideline of 5 micrograms per cubic metre. Loni replaces Byrnihat, Meghalaya, which held the top place in the 2024 report.
The ranking is not a statistical fluke. Loni sits in the Delhi-NCR airshed, where vehicle exhaust, construction dust, industry and seasonal crop burning combine to give some of the highest sustained PM2.5 readings anywhere. A city next to India's capital now leads the global ranking.
Fewer cities meet the guideline
The report found that only 14% of cities worldwide met the WHO annual PM2.5 guideline of 5 micrograms per cubic metre, down from 17% the previous year. Only thirteen countries and territories met the standard at the national level: French Polynesia, Puerto Rico, the U.S. Virgin Islands, Barbados, New Caledonia, Iceland, Bermuda, Reunion, Andorra, Australia, Grenada, Panama, and Estonia.
India's national average PM2.5 concentration stood at 48.9 micrograms per cubic metre (down from 50.6 in 2024), nearly ten times the WHO limit. The country ranked sixth most polluted in 2025, behind Pakistan (67.3), Bangladesh (66.1), Tajikistan (57.3), Chad (53.6) and the Democratic Republic of the Congo (50.2). In the 2024 report, at 50.6, it ranked fifth.
Less independent monitoring
One finding in the report is about monitoring and not about pollution levels. In March 2025, the United States State Department ended its air quality monitoring programme at embassies and consulates. The programme had given independent, public PM2.5 readings in dozens of countries, often serving as a check on official data.
The Centre for Research on Energy and Clean Air (CREA) reported that monitoring efforts were weakened in 44 countries, and six were left without any monitoring at all. In India, where citizens have long questioned the accuracy and siting of official CPCB monitoring stations, losing an independent check makes accountability harder.
What the research says
The IQAir report builds on two 2024 studies in The Lancet Planetary Health that for the first time established causal links between PM2.5 exposure and mortality in India, using econometric methods in place of simple correlation.
The first study (Jaganathan et al. 2024), using a difference-in-differences approach, estimated 1.5 million additional deaths per year compared to conditions where India met WHO guidelines. This is separate from the Lancet Countdown 2025 (published October 2025), which estimated over 1.72 million deaths in India in 2022 attributable to anthropogenic PM2.5, up 38% since 2010. That is a count of all attributable deaths in a single year, not a revision of the excess-deaths figure above made by the same method. The second, a multi-city causal modelling study covering ten Indian cities, confirmed significant short-term mortality effects from daily PM2.5 exposure.
A separate study in Science Advances found that the air quality improvements India has achieved in recent years have been shared unequally. Wealthier areas saw larger falls (about 8.1% against 3.6% for the poorest).
What this means
India's air is not improving fast enough to protect health. The IQAir data shows concentrations rising in some cities, Loni among them, while the National Clean Air Programme nears its 2026 deadline with most cities far from their targets.
JanVayu exists because accountability needs a public record. If this data is not archived, explained and open to citizens, it cannot drive the changes that 1.4 billion people need.