Pakistan topped the global pollution charts in 2025, with hazardous PM2.5 particle levels up to 13 times higher than the safe limit recommended by the World Health Organization, according to a report released by Swiss air quality monitoring firm IQAir.
The annual IQAir report showed that only 13 countries and territories met the WHO guideline of less than 5 micrograms of PM2.5 per cubic metre — up from seven in 2024. In contrast, 130 out of 143 monitored regions exceeded safe limits. Bangladesh and Tajikistan ranked second and third most polluted, while Chad, the smoggiest country in 2024, fell to fourth, largely due to missing data after the US shut down a global monitoring programme last March.
In terms of cities, Loni in India had the world’s highest PM2.5 levels at 112.5 micrograms per cubic metre, followed by Hotan in China’s Xinjiang region at 109.6 micrograms. The 25 most polluted cities were concentrated in India, Pakistan, and China.
Globally, only 14% of cities met the WHO air quality standards in 2025, down from 17% the previous year. Canadian wildfires contributed to rising PM2.5 levels across North America and Europe.
Countries reporting improvements included Laos, Cambodia, Indonesia, and Mongolia, which saw a 31% drop in average PM2.5 levels to 17.8 micrograms per cubic metre. Overall, 75 countries recorded lower PM2.5 levels than the previous year, while 54 reported higher concentrations.
The report highlights the ongoing global air pollution crisis and the urgent need for policies to reduce harmful emissions.