Kolkata: With the minimum temperature in Kolkata dipping to 22 degree Celsius, the air quality index (AQI) in the city of joy deteriorated significantly and figured in the poor category, as per the AQI bulletin released at 4 pm by the Central Pollution Control Board (CPCB).
Among the six non-attainment cities in the state—four, including Kolkata, were in the poor category and two namely Asansol and Durgapur were in the ‘moderate’ range. This is the first time since March this year when the AQI has slipped into the ‘poor’ category.
As per CPCB data, Haldia had the highest AQI of 252 , Barrackpore 248, Howrah 239 and Kolkata 219.
The Paribesh App of the West Bengal Pollution Control Board showed that even at around 7 pm on Wednesday, reading at some places like Victoria Memorial and Jadavpur in Kolkata figured in the ‘very poor’ category as did places like Padmapukur, Belur in Howrah. The AQI reading at other places like Ballygunge , Rabindra Sarobar, Bidhannagar, Behala, Tangra were all in the poor category throughout the day. A senior WBPCB official said that AQI does not represent any moment, it is an average of preceding 24 hours.
“This is meteorologically-governed. Planetary boundary layer, where we find maximum concentration of pollutants, comes close to the surface with falling temperature and wind speed that leads to rise in AQI,” explained Kalyan Rudra, chairman of WBPCB.
An AQI between 0-50 is considered good, 51-100 satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor and 401-500 severe.
“We have found that air pollution remains a concern in Kolkata from September till February. Even in green zones like Victoria Memorial, Rabindra Sarobar, the air quality remains in the poor category.
Doctors have advised morning walkers like me to come for a walk not in the early morning but after sunrise as the air quality slightly improves during that time. Patients with heart problems, asthma and those with co-morbidity are advised to avoid highly-polluted places during winter,” said environmentalist SM Ghosh.