New Delhi: In its latest global ranking, Swiss firm IQAir has identified the most polluted regions worldwide, including cities and entire countries struggling to curb air pollution. The findings are part of IQAir’s 2025 World Air Quality Report, released on 24 March, in which India once again features prominently on an undesirable list.
According to the ranking, the most polluted city on the planet in 2025 is a small town on the outskirts of Uttar Pradesh’s Ghaziabad.
Where is Loni?
Loni is primarily a town in the Ghaziabad district of Uttar Pradesh. It is located within the National Capital Region (NCR). It forms part of the Ghaziabad metropolitan area, known as a large residential zone near Delhi, and is governed by the Loni Municipal Council.
Loni recorded an annual average PM2.5 concentration of 112.5 micrograms per cubic metre, a nearly 23% increase from 2024 and more than 22 times the safe limit set by the World Health Organization (WHO).
PM2.5 refers to tiny particles in the air measuring less than 2.5 micrometres in diameter. These particles are so fine that they can enter the lungs and bloodstream directly.
Byrnihat in Meghalaya was ranked third globally in terms of air pollution, while Delhi ranked fourth. India ranked sixth among the most polluted countries.
