Ula, small town in Nadia ranks 10th globally as highly air-polluted city
Telegraph | 6 April 2026
Ula, a small town in Bengal near Ranaghat in Nadia, also known as Birnagar, is the 10th most air-polluted city in the world in 2025, according to a global report released on Sunday.
The World Air Quality Report 2025, published by IQAir, shows that Ula and some towns on the fringes of Calcutta are some of the most polluted cities in Bengal.
Calcutta has seen better air quality post-COVID, but it is still more polluted than the national average. It has been pushed to 77th rank globally with an annual average of particulate matter 2.5 — refers to fine atmospheric particulate matter with a diameter of less than 2.5 micrometres — of 51 micrograms per cubic metre in 2025. India’s average is 40 micrograms.
PM 2.5 pollutants are tiny and hence extremely dangerous as they can invade deep into the lungs and enter the bloodstream, causing serious cardiovascular and respiratory health problems.
IQAir combines satellite data with real-time ground-based data, including government stations and low-cost sensors, to measure and map air pollution across the world.
Ula, the historic heritage town famous for its 18th-century mansions and temples, has a population of around 40,000. It was found to have a PM2.5 of 86.8 micrograms per cubic metre in 2025. The figure is more than 17 times the World Health Organisation’s specified safe guideline of 5 micrograms.
The West Bengal Pollution Control Board’s remote sensor-based air pollution measurement, as showcased by IQAir, showed that Ula had a PM2.5 value of 113 micrograms and air quality index (AQI) of 191 at 7pm on Sunday, vindicating the trend. This AQI is expected to trigger breathing discomfort for people with lung and heart diseases.
According to the World Air Quality Report 2025, a copy of which is with The Telegraph, Madhyamgram and Barrackpur on the northern fringes of Calcutta, and Baruipur on the southern fringes were the most polluted cities after Ula in Bengal.
Howrah, Bali, Durgapur, Asansol, Calcutta, Haldia and Siliguri are the other most polluted cities in Bengal.
Asked why Ula had such high air pollution, Kalyan Rudra, the chairman of the state pollution control board, said on Sunday evening that it was difficult to track the exact reason without proper groundwork. "However, Nadia has a very high cropping density that may play a role by producing high levels of dust,” he said.
Another official pointed out: “We need to see if small local industries such as rice mills and the like are pushing up pollution in the region.”
The global report, which covered 9,446 cities across 143 countries, found that five of the 10 most polluted cities in the world were in India. Loni, a small town 20km from Delhi, was found to be the most polluted in the world, with a pollution level over 22 times that of the WHO guideline limits, followed by Byrnihat in Meghalaya ranked third globally. Delhi and Ghaziabad ranked fourth and seventh globally, respectively.
Among countries, Pakistan was the most polluted, followed by Bangladesh. India has been ranked sixth.
“The latest results underline the importance of shifting the focus from specific cities, as being the current policy, to aggressively targeting key pollution sources across entire airsheds with speed and scale to protect public health,” said Anumita Roy Choudhury, an air pollution expert with the Delhi-based environmental thinktank, Centre for Science and Environment (CSE).