A new global assessment has revealed a decline in air quality worldwide, with only 13 countries meeting recommended safety standards in 2025.

The World Air Quality Report, released by Swiss monitoring firm IQAir, shows that just 14 per cent of cities globally recorded pollution levels within limits set by the World Health Organization, down from 17 per cent in 2024.

The report analysed data from 9,446 cities across 143 countries, regions, and territories, pointing to a broad deterioration in air quality.

Fine particulate matter, known as PM2.5, remains a major concern due to its ability to penetrate deep into the lungs and bloodstream. Exposure is linked to severe health conditions, including respiratory and cardiovascular diseases, as well as cancer.

Only a small group of countries—including Andorra, Estonia, and Iceland—met the WHO’s annual guideline of 5 micrograms per cubic meter. Others within safe limits were largely island nations such as Australia, Barbados, and Bermuda.

In contrast, 130 out of 143 countries exceeded safe pollution thresholds. South Asia recorded the worst levels, with Pakistan, Bangladesh, and Tajikistan ranking among the most polluted.

The report also noted that the world’s 25 most polluted cities were located in India, Pakistan, and China, with Loni emerging as the worst affected, recording PM2.5 levels more than 22 times above WHO guidelines.

Researchers attributed the worsening trend to factors such as wildfire smoke, dust storms, and extreme weather events linked to climate change, while also highlighting gaps in air quality monitoring in many parts of the world.