Kolkata's Air quality (AQI) on Sunday decreased marginally in comparison to the previous day but remained in the 'poor' category in north Kolkata while it was 'moderate' elsewhere in the city, an official of the West Bengal Pollution Control Board (WBPCB) said.
Three days after the Kali Puja and Diwali festivals when crackers were burnt in different pockets of the city, the air quality index (AQI) at 8 pm on Sunday was 263 (PM 2.5) in the air monitoring station at Rabindra Bharati University campus on BT Road reflecting the air pollution in Sinthi, Cossipore, Baranagar and Dumdum areas of North Kolkata.
The AQI was 243 (PM 2.5) on Saturday night at the same monitoring station.
The WBPCB official attributed the fall in air quality to wintry conditions that lead to accumulation of particulates from vehicular emission, smoke from chullah, construction of high rise buildings, etc.
An AQI between 0 and 50 is considered 'good', 51-100 'satisfactory', 101-200 'moderately polluted', 201-300
'poor', 301-400 'very poor' and 401-500 'severe', while the AQI above 500 falls in the 'severe plus' category.
The air quality was 'moderate' in Ballygunje (152), Bidhannagar 146), Fort William (162), Jadavpur (170), Rabindra Sarobar (142) and Victoria Memorial (132) air monitoring stations of PCB in other parts On Sunday.
The index was 157 at Jadavpur, 134 at Ballygunje, 160 at Bidhannagar, 162 at Fort William and 130 at Rabindra Sarobar on Friday.
Environmentalist Somendra Mohan Ghosh said the rise in particulate matters was 15 to 20 per cent high in different parts of the city on the night of Kali Puja and Diwali on November 4 and continued to be so in the next three days.
He alleged that fireworks were still being burnt in certain pockets of Kolkata.
"This, along with typical wintry conditions, is triggering the dip in air quality ambiance and endangering conditions of Covid-19 and other COPD (Chronic obstructive pulmonary disease) patients," the environmentalist said.
(With PTI Inputs_)