Air quality remained 'poor' in Kolkata and its neighbourhood on Monday morning, a day after Kali Puja and Diwali, as a haze engulfed the metropolis, officials said.

Such a situation was not only caused by the bursting of firecrackers on Sunday, but also due to weather conditions during this time of the year when small particulate matters remain in the air with the presence of fog and smoke, they said.

In Kolkata, the Air Quality Index (AQI) reading was 284 at Victoria Memorial, 262 at Fort William, 254 at Jadavpur, 234 at Rabindra Sarobar and 236 at Salt Lake, while it was 310 at Ghusuri in neighbouring Howrah district and 252 at Asansol in Burdwan, on Monday morning, West Bengal Pollution Control Board (WBPCB) data showed.

An AQI between 0 and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe', the officials said.

The control room at Paribesh Bhavan, the headquarters WBPCB was functioning till late in the night on Sunday, while drone surveillance and mobile teams were also in operation at various hotspots in the city and adjacent areas, they said.

As per the reading of air monitoring stations, the AQI at 6 pm on Sunday was 216 at Rabindra Sarobar, Ballygunje (257), Victoria Memorial (276), Jadavpur (267), Fort William (255), Bidhannagar (243) and Ghusuri (262).

Environmentalist Naba Dutta said the pollution levels shot up after sunset on Sunday, as celebrations with fireworks began in different parts of the city. "If the levels aggravate, it will cause respiratory problems," he cautioned.

"We recommend sprinkling water on plants in the evening to reduce the impact of pollution,” another green activist Somendra Mohan Ghosh said.

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