Pakistan world’s most polluted country in 2025: Report

Fine particulates in Pakistan’s air highest in the world last year, exceeding WHO guidelines by up to 13 times, monitoring firm says.

Pakistan was the world’s smoggiest country in 2025 with concentrations of hazardous fine particles known as PM2.5 up to 13 times higher than the World Health Organization’s (WHO’s) recommended level, a report finds.

In its annual report published on Tuesday, IQAir, a Swiss air quality monitoring firm, said only 13 countries and territories managed to keep their average fine particulate levels below the WHO guideline, but that number was up from seven in 2024.

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IQAir sourced data from 9,446 cities in 143 countries, regions and territories. Overall, 130 of 143 monitored countries and territories failed to meet the WHO standard.

That standard is based on a measurement of fine particulate matter in the air of 2.5 microns or less in diameter. The WHO standard for healthy air quality is an average PM2.5 of no more than 5 microgrammes per cubic metre. Pakistan’s PM2.5 level was 67.3 microgrammes.

Pakistan’s average PM2.5 concentration in 2024 was 73.7 microgrammes.

PM2.5 is considered a major contributor to premature births while prolonged exposure has also been linked to higher likelihoods of neurodegenerative conditions, including dementia, Parkinson’s disease and Alzheimer’s disease.

Bangladesh and Tajikistan ranked second and third on IQAir’s list of the most polluted countries while Chad, statistically the smoggiest country in 2024, was in fourth place in 2025.

Open pit mining causes a large amount of fine particulate matter to be emitted into the air [File: Yirmiyan Arthur/AP Photo]

However, the apparent decline in PM2.5 levels there is likely the result of gaps in the data.

The United States shut down a global monitoring programme last year that compiled pollution readings from its embassy and consulate buildings, citing budget constraints.

The decision eliminated a primary data source for many smog-prone countries, and Burundi, Turkmenistan and Togo were excluded from the 2025 report because of information gaps.

“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,” Christi Chester Schroeder, lead author of the report, said.

India’s Loni most polluted city

Loni, a city in northern India, was identified as the world’s most polluted city in 2025 with average PM2.5 levels of 112.5 microgrammes per cubic metre. Hotan in northwestern China’s Xinjiang region was second with levels of 109.6 microgrammes.

All of the world’s top 25 most polluted cities were in China, India and Pakistan, the report found.

Globally, only 14 percent of cities met the WHO air quality standard in 2025, down from 17 percent a year earlier. Among the 13 countries that did meet the WHO guideline last year were Australia, Iceland, Estonia and Panama.

Laos, Cambodia and Indonesia reported significant reductions in PM2.5 compared with 2024, mainly due to wetter and windier weather caused by the La Nina phenomenon. Mongolia’s average PM2.5 concentrations fell 31 percent to 17.8 microgrammes per cubic metre.

In total, 75 countries recorded lower PM2.5 levels in 2025 than a year earlier while 54 saw higher average concentrations, IQAir said.

Wildfires, driven by climate change, were a key factor behind worsening global air quality in 2025 as record levels of biomass burning in Europe and Canada released about 1,380 megatonnes of carbon.