Kolkata air quality improves but seasonal challenges remain

Kolkata sees significant PM2.5 reduction but winter spikes remain a concern, outperforming Delhi in air quality improvements.

A recent report about the air quality in Kolkata has indicated significant reductions in PM2.5, but the winter spikes remain a concern in densely populated areas.

According to ‘Towards Clear Skies 2025,’ which uses data from the AtlasAQ Platform, the city recorded an annual average PM2.5 level of 44.8 μg/m3 in 2024, making it one of the best-performing metropolitan areas in India under the NCAP framework.

“Kolkata’s PM2.5 levels dropped from 57.1 μg/m3 in 2019 to 44.8 μg/m3 in 2024, representing a significant 21.5% reduction,” a press statement by Respirer Living Sciences said.

The report also made a comparative analysis of Kolkata’s air quality and found that the air quality in Kolkata was better than Delhi (107.0 μg/m3), reflecting the success of targeted interventions.

However, the winter months, particularly December and January, saw PM2.5 levels frequently exceeding 90 μg/m3, driven by low wind dispersion and increased emissions from heating and transport. Regional spikes in air quality were reported in Howrah and surrounding industrial areas.

“High industrial density and vehicular congestion in these regions resulted in PM2.5 levels frequently exceeding 65 μg/m3, well above the city’s average,” the report said.

Ronak Sutaria, founder of Respirer Living Sciences, said that Kolkata’s consistent improvements demonstrate the impact of stricter industrial regulations and enhanced public transport, but the city’s high population density and seasonal pollution spikes remain areas of concern.