Pakistan Tops List as World's Most Polluted Country in 2025

According to a report by IQAir, a Swiss air quality monitoring firm, 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.

The report, which sourced data from 9,446 cities in 143 countries, regions and territories, found that only 13 countries and territories managed to keep their average fine particulate levels below the WHO guideline, an increase from seven in 2024.

Pakistan's PM2.5 level was 67.3 microgrammes per cubic metre, significantly exceeding the WHO standard of 5 microgrammes per cubic metre. In comparison, Pakistan's average PM2.5 concentration in 2024 was 73.7 microgrammes.

Prolonged exposure to PM2.5 has 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.

The report also noted that 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.

Globally, only 14 percent of cities met the WHO air quality standard in 2025, down from 17 percent a year earlier. The report highlighted that 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.