Kolkata and Howrah experienced a sharp decline in air quality on the night of Kali Puja, October 20, 2025, due to the widespread bursting of firecrackers. This occurred despite guidelines and restrictions issued by the West Bengal Pollution Control Board (WBPCB) and the police. Environmentalists have criticized the authorities for the insufficient enforcement of regulations, which exposed vulnerable populations to elevated levels of pollution.
Air Quality Index (AQI) levels in several areas of Kolkata and Howrah reached "severe" levels. For instance, at 10 PM on Monday, the AQI at Belur in Howrah was recorded at 364. Padmapukur also breached the "severe" category with an AQI of 361, while Ghusuri recorded an AQI of 252. In Kolkata, Ballygunge had an AQI of 173 and Jadavpur recorded 169 at 10 PM. The WBPCB reported an AQI of 186 PM 2.5 at Victoria Memorial. These readings indicate a significant deterioration from the "moderate" levels observed in some of these areas prior to Kali Puja.
Prior to Kali Puja, on October 18, 2025, the air quality in Kolkata had already begun to nosedive, with AQI reaching close to 250 in certain areas, prompting the WBPCB to increase vigilance. The WBPCB had attributed the increasing AQI to weather changes and a lack of moisture in the air due to the withdrawal of the monsoon, not directly to firecrackers. However, environmentalists expressed concerns about illegal firecrackers entering the market.
In the lead-up to Kali Puja, Kolkata Police had seized a significant amount of banned firecrackers and made arrests. They also announced restrictions, permitting only authorized green firecrackers to be used for a limited time between 8 PM and 10 PM on October 20. The Calcutta High Court had also directed the state government to ensure the effective implementation of measures to curb air and noise pollution during Kali Puja and Diwali. Despite these efforts, widespread violations were reported, with firecrackers being burst beyond the permissible time.
The bursting of firecrackers, even those certified as "green," raises concerns due to the harmful chemicals they contain. WBPCB Chairman Kalyan Rudra noted that light-emitting firecrackers contain heavy metals that can affect the central nervous system, skin, respiratory tract, and potentially lead to cancer. Environmental activist Subhas Datta highlighted the overall harm caused by firecrackers, stating that even green fireworks only reduce pollution by about 30% compared to ordinary ones.
