A view of smog in the Punjab province. PHOTO FILE: AFP
Pakistan has been ranked the world’s smoggiest country in 2025, with concentrations of dangerous small particles known as PM2.5 up to 13 times higher than the level recommended by the World Health Organization, according to a study released Tuesday. These particles, from combustion, industrial emissions and wildfires, penetrate deep into the lungs and bloodstream, contributing to heart and respiratory diseases, as well as premature deaths.
Swiss air quality monitoring company IQAir said in its annual report that 13 countries and territories kept average PM2.5 levels last year at the WHO standard of less than 5 micrograms per cubic meter, up from seven in 2024.
Karachi recorded dangerously high levels of PM2.5 on September 29, 2025, with an AQI above 100, classified as “unhealthy for sensitive groups”. Cities like Hyderabad and Lahore are also facing similar problems when it comes to air quality.
The 25 most polluted cities in the world are all in India, Pakistan and China. Loni, India, was the world’s most polluted city in 2025, with average PM2.5 levels of 112.5 micrograms, followed by Hotan, in northwest China’s Xinjiang region, with 109.6 micrograms.
Bangladesh and Tajikistan occupy the second and third places on the list of the most polluted countries.
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In total, 130 of the 143 countries and territories monitored did not comply with WHO guidelines. Only 14% of the world’s cities met the WHO standard in 2025, compared to 17% a year earlier, with wildfires in Canada driving up PM2.5 in the United States and as far away as Europe.
Countries that met the standard in 2025 included Australia, Iceland, Estonia and Panama.
Laos, Cambodia and Indonesia all reported significant reductions in PM2.5 compared to the previous year, mainly thanks to wetter and windier La Niña weather. Mongolia saw average concentrations drop by 31%, to 17.8 micrograms per cubic meter.
Chad, statistically the most polluted country in 2024, ranked fourth in 2025, but last year’s drop in PM2.5 concentrations is likely the result of data gaps.
Last March, the United States ended a global monitoring program that compiled pollution data collected in its embassy and consulate buildings, citing budgetary constraints. “The loss of data in March made it look like there was a significant drop in PM2.5 levels (in Chad), but the fact is we don’t know,” said Christi Chester Schroeder, lead author of the IQAir report.
The U.S. decision eliminated a primary data source for many smog-prone countries, and Burundi, Turkmenistan and Togo were excluded from the 2025 report due to information gaps.
A total of 75 countries reported lower PM2.5 levels in 2025 compared to the previous year, and 54 of them recorded higher average concentrations, IQAir said.
