Kolkata, Nov 23 (PTI) Even 10 days after Diwali and Kali Puja festivals, the city’s air quality remained poor causing serious health concerns to citizens.

While Ballygunge area recorded an air quality index (AQI) of 296 at 6pm on Thursday, Bidhannagar (284) and Jadavpur (252) were not far behind at the same time of the day, a West Bengal Pollution Control Board (WBPCB) official said.

Among other air monitoring stations, Rabindra Sarobar registered 254 AQI at 6pm, the official said, adding all the readings were classified as 'poor' in environmental terms.

Even an eco-sensitive zone such as Rabindra Sarobar crossed the 300-mark during a period of the day, the official added.

During the Kali Puja and Diwali festivals, the AQI ranged between 189-255 across the city.

The official said as the typical wintry conditions set in and the temperature dipped below 20 degree celsius, cases of respiratory problems have started to spiral.

'An AQI between 201 and 300 triggers health alert, over 300 triggers health warnings of emergency conditions,' the official added.

'The entire population is likely to be affected by serious health effects if there is no rain caused by depression or other weather disturbances,' enviornmentalist Somendra Mohan Ghosh said.

Till a week ago, the AQI hovered between 100 - 200 (moderate) while on Tuesday, the average air quality ranged between 160-220 in the city.

AQI between 0-50 is considered good, 51 and 100 satisfactory, 101-200 moderate, 201-300 poor, 301 and 400 very poor and 401-500 'severe'. PTI SUS MNB