According to the annual report by Swiss company 'IQAir' on air quality monitoring, only 13 countries and regions maintained average levels of polluting fine particles within the World Health Organization's standard, i.e., less than five micrograms per cubic meter last year, compared to just seven countries in 2024. The report also clarified that out of 143 countries and regions monitored, 130 did not meet the WHO's guideline standards. Bangladesh and Tajikistan ranked second and third on the list of the most polluted countries, while Chad, which was the most polluted in 2024, fell to fourth place last year. The Indian city of Lonie topped the list of the world's most polluted cities in 2025 with an average of 112.5 micrograms of polluting fine particles, followed by the city of Hotan in the Xinjiang region of northwestern China with an average of 109.6 micrograms. All of the world's 25 most polluted cities are located in India, Pakistan, and China. Only 14% of the world's cities met WHO standards in 2025, down from 17% in 2024. Forest fires in Canada led to increased levels of fine particulate matter across the United States and even into Europe. Among the countries that met the standard in 2025 were Australia, Iceland, Estonia, and Panama. A study published yesterday revealed that Pakistan topped the list of the world's smoggiest countries in 2025, with concentrations of dangerous fine particles known as 'PM2.5' exceeding the WHO-recommended limit by up to 13 times.
