Air pollution continues to be one of the most pressing global health threats, contributing to one in nine deaths annually, as per the World Health Organisation (WHO). With fine particulate matter (PM2.5) linked to severe conditions such as heart disease, cancer, asthma, and developmental issues in children, the 2024–25 global rankings offer a clear picture of regions most at risk — and those leading in clean air efforts.
According to the latest IQAir 2024–25 report, South Asia remains at the forefront of the global air pollution crisis. The top 10 most polluted countries are overwhelmingly led by nations in this region, with Bangladesh ranking second, Pakistan third, and India fifth. Notably, India showed a slight improvement, dropping from third to fifth place, with its average PM2.5 concentration falling to 50.6 µg/m³ from 54.4 µg/m³ in 2023.
“India dropped from third to fifth place,” the report noted, signaling marginal yet hopeful progress in managing pollution levels. Pakistan, however, presented an alarming scenario, with an average PM2.5 level of 73.7 µg/m³, solidifying its position as the third most polluted country globally.
The top 5 most polluted countries are:
Chad (91.8 µg/m³)
Bangladesh (78 µg/m³)
Pakistan (73.7 µg/m³)
Democratic Republic of the Congo (58.2 µg/m³)
India (50.6 µg/m³)
In stark contrast, Nordic nations and island countries dominate the least polluted rankings. The Bahamas leads globally with a PM2.5 concentration of just 2.3 μg/m³, setting a global benchmark in air purity. “The Bahamas topped the list of least polluted countries in 2024,” the report highlights.
Other clean air leaders include Iceland, Finland, Sweden, and Southern Hemisphere nations like New Zealand (4.3 μg/m³) and Australia, benefitting from robust environmental regulations and cleaner energy practices.
While many countries continue to battle worsening pollution due to rapid industrialisation, urbanisation, and climate impacts, the rankings reflect a growing divide in global air quality — one that urgently demands unified action.
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