Pakistan has been ranked the world's most polluted country in 2025, with hazardous small particles known as PM2.5 up to 13 times higher than the recommended World Health Organization level, according to a Swiss air quality report.
The IQAir report found that 130 out of 143 monitored countries and territories failed to meet the WHO guideline, with Bangladesh and Tajikistan ranking second and third on the most polluted list.
India's Loni was the world's most polluted city in 2025, with average PM2.5 levels of 112.5 micrograms, followed by Hotan in the northwestern Chinese region of Xinjiang at 109.6 micrograms.
Only 14% of the world's cities met the WHO standard in 2025, down from 17% a year earlier, with Canadian wildfires driving up PM2.5 across the United States and as far as Europe.
