Kolkata: A four-year analysis by Respirer Living Sciences revealed that while Kolkata has made steady progress in reducing PM10 pollution since 2021, air quality in the city remained hazardous throughout the year. This defies the common belief that summer offers temporary relief from pollution.
The study, based on data from AtlasAQ, Respirer's air quality platform, highlights that Kolkata's PM10 levels declined from 111.5 µg/m³ in 2021 to 91.6 µg/m³ in 2024. While this downward trend is encouraging, every annual average still significantly exceeds the National Ambient Air Quality Standards (NAAQS) limit of 60 µg/m³ — even during summer months, which typically witness cleaner air due to atmospheric dispersion.
"Kolkata's trend is moving in the right direction but we cannot mistake marginal progress for clean air. PM10 levels continue to breach safety limits in every season. This highlights the need for deeper urban reforms and sustained enforcement," said Ronak Sutaria, founder and CEO of Respirer Living Sciences.
Detailed station-level analysis underscores the widespread nature of Kolkata's air quality challenges. The Rabindra Bharati University station, which once recorded PM10 levels as high as 146.4 µg/m³ in 2021, showed the most substantial improvement, dropping to 86.7 µg/m³ in 2024. However, several key locations, including Victoria Memorial (102.9 µg/m³), Fort William (100.2 µg/m³), and Jadavpur (93.8 µg/m³), remain well above the safe threshold.
Even residential neighbourhoods like Rabindra Sarobar (71.0 µg/m³) and Ballygunge (96.8 µg/m³) reported PM10 levels far exceeding the national safety limit, emphasising that no part of the city is spared from chronic particulate exposure.
While Kolkata's figures remain alarming, its consistent downward trend places it among a small group of Indian cities — including Mumbai and Hyderabad — that showed improvement in PM10 levels over the 2021-2024 period. This is likely the result of localised interventions, such as stricter emission controls, green initiatives, and public transportation enhancements.
In contrast, cities like Delhi, Patna, Chandigarh, and Lucknow continue to grapple with some of the highest PM10 concentrations in the country, with Delhi consistently averaging over 200 µg/m³ each year. Seasonal spikes during winter months — driven by temperature inversions and biomass burning — further compound these challenges.
The report urges policymakers to build on Kolkata's momentum by implementing stronger emission regulations, particularly around high-traffic corridors and construction zones. It also recommends expanding public transport networks and continuing real-time air quality monitoring to ensure sustained progress.
"Air quality must be treated as a core urban governance issue. With the right investments and community engagement, cities like Kolkata can turn the tide. But the time to act is now," the report said.
As Kolkata inches closer to cleaner skies, the message is clear: progress is possible, but only through unwavering commitment, systemic change, and collective effort.