World’s most polluted city revealed — And it’s in India!

The city recorded an average PM2.5 concentration of 112.5 micrograms per cubic metre, marking a significant deterioration in air quality.

Five Indian cities featured among the most polluted globally in 2025. “Loni, India, was the most polluted city, recording an annual average PM2.5 concentration of 112.5 µg/m³—a nearly 23% increase from 2024 and more than 22 times the WHO guideline,” IQAir said in a statement.

Apart from Loni, the other Indian cities in the top 10 include Byrnihat, Delhi, Ghaziabad, and Ula.

The report further noted that the world’s 25 most polluted cities are all located across India, Pakistan, and China, with India accounting for three of the top four.

“Air quality is a fragile asset that requires active stewardship to protect public health,” said Frank Hammes, Global CEO of IQAir. “The 2025 World Air Quality Report makes clear that without monitoring, we cannot fully understand what’s in the air we breathe. Expanding access to real-time data empowers communities to act. By reducing emissions and addressing climate change, we can drive meaningful, lasting improvements in global air quality.”