Loni India’s most polluted city in ߩ Delhi, Noida, Ghaziabad dominate region’s toxic air list

Why Loni topped the list

On why Loni emerged the post polluted, expert Dr Gufran Beig, founder and project director of the System of Air Quality and Weather Forecasting and Research (SAFAR), said it is possibly due to the availability of the air quality data present.

“It is possible that in the next analysis, some other Indian city or any other in a different country would emerge at the top. It depends on the dense network of monitoring stations. Countries like Ghana won’t find a ranking though it might be polluted just because it does not have a mechanism in place. Variations come because stations are coming up,” he said, adding that pollution sources affecting Loni needs to be studied.

Manoj Kumar, analyst at CREA, said that while they conducted their own analysis, the whole stretch appeared to be polluted.

“The causes for pollution in Loni is not very unique from Delhi… vehicular pollution, waste burning could be the possible reasons but nothing can pin-point. We need to pick one source at a time, study them and then monitor how to eliminate it,” he said, adding that pollution is not just during winters but also prominent in summers as well.
“In winters, it is PM 2.5 and PM 10 but in summers it is ozone, CO as well as No2, the pollution is year long,” he said.
Last year, the Capital had witnessed protests at India Gate in November as Delhi’s daily average concentration peaked near a hazardous 460 µg/m³, per the report.

How other cities fared

The broader national landscape reflects a consistent pattern of elevated particulate matter, even as India’s overall PM 2.5 average dropped by 3 per cent to 48.9 µg/m³.

India currently boasts the most robust monitoring network in Central and South Asia, yet the data reveals that the country was home to 17 of the world’s 20 most polluted cities in 2025, the report states.

Byrnihat emerged as the second most polluted city in the region, registering an annual average of 101.1 µg/m³.
Among other major metropolises, Kolkata recorded a high annual PM 2.5 average of 51.0 µg/m³, followed by Mumbai at 34.2 µg/m³ and Hyderabad at 33.3 µg/m³.

Chennai and Bengaluru reported annual averages of 31.3 µg/m³ and 27.5 µg/m³, respectively. Providing a rare bright spot, the southern city of Tirunelveli was the only Indian municipality to feature among the 15 least polluted regional cities, logging an annual average of 15.1 µg/m³.

The persistent pollution across these areas is fueled by a combination of vehicular and industrial emissions, construction dust, and seasonal crop residue burning.

Winter conditions heavily plagued the broader Indo-Gangetic Plain due to temperature inversions, with December PM 2.5 averages spiking by an average of 62 per cent in cities across Uttar Pradesh.

Efforts to combat the crisis continue to face significant structural hurdles, the report noted. Despite the National Clean Air Programme’s goal to reduce pollution by 40 per cent by 2025-2026, 64 per cent of its funding has been dedicated to road dust reduction, it stressed.

This leaves only 15 per cent of funding to reduce biomass burning, 13 per cent for vehicle emissions, and a mere 1 per cent to counter industrial pollution. Further, weak enforcement of vehicular and industrial emission norms, combined with relaxed sulphur rules for coal plants, likely continue to impact the nation’s air quality, the report stated.