130 Nations Fail WHO Air Quality Standards, Pakistan Ranked Most Polluted Country In 2025

Last Updated:March 24, 2026, 13:05 IST

Bangladesh and Tajikistan ranked second and third on the most polluted list. Chad, which had been the smoggiest country in 2024, fell to fourth place in 2025.

Pakistan was ranked the world’s smoggiest country in 2025, with levels of hazardous PM2.5 particles reaching up to 13 times the World Health Organization’s recommended limit, according to research released on Tuesday.

Bangladesh and Tajikistan ranked second and third on the most polluted list. Chad, which had been the smoggiest country in 2024, fell to fourth place in 2025, although the drop is likely due to data gaps rather than actual improvements.

“The loss of the data in March made it appear there was a significant drop in PM2.5 levels (in Chad), but the fact of the matter is that we don’t know," said Christi Chester Schroeder, lead author of the IQ Air report.

Swiss air quality monitoring company IQ Air noted in its annual report that 13 countries and territories maintained average PM2.5 levels below the WHO standard of 5 micrograms per cubic meter last year, an increase from seven in 2024.

The report highlighted several key findings: out of 143 monitored countries and territories, 130 failed to meet WHO guidelines.

The US had shut down a global monitoring program in March, which collected pollution data from its embassies and consulates, citing budget constraints. This decision removed a key data source for smog-prone countries, leading to exclusions in the 2025 report for Burundi, Turkmenistan, and Togo.

At the city level, India’s Loni was the world’s most polluted in 2025, with average PM2.5 concentrations of 112.5 micrograms per cubic meter, followed by Hotan in China’s Xinjiang region at 109.6 micrograms.

The top 25 most polluted cities were all located in India, Pakistan, and China.

Globally, only 14 per cent of cities met the WHO standard in 2025, down from 17 per cent the previous year. Canadian wildfires contributed to elevated PM2.5 levels across the United States and as far as Europe. Countries meeting the WHO standard included Australia, Iceland, Estonia, and Panama.

Several nations reported notable improvements: Laos, Cambodia, and Indonesia saw significant PM2.5 reductions due to wetter and windier La Niña conditions, while Mongolia recorded a 31 per cent drop, averaging 17.8 micrograms per cubic meter.

Overall, 75 countries reported lower PM2.5 levels compared to 2024, whereas 54 experienced increases, IQ Air stated.

(With inputs from agencies)

News world 130 Nations Fail WHO Air Quality Standards, Pakistan Ranked Most Polluted Country In 2025

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