KOLKATA: Cyclone 'Bulbul', which wreaked havoc in the coastal districts of West Bengal and disrupted normal life in the city, managed to significantly improve the air quality in the metropolis, a senior official said on Sunday.
Heavy rain and gusty winds accompanying the tempest cleared fine particulate matters from the city's air, improving its Air Quality Index (AQI), an official of the West Bengal Pollution Control Board (WBPCB) said.
The city's air quality became 'good' and 'satisfactory' after the storm, which was 'poor' two days back, according to the WBPCB readings.
While the AQI (PM 2.5) at Ballygunge air monitoring station read 46 at 4 pm on Sunday, that at Fort William was 40 during the same period, a WBPCB official said.
He said the AQI (PM 2.5) at Victoria Memorial air monitoring station read 46 while the corresponding readings at Jadavpur and Rabindra Bharati University stations were 19 and 54 during the same period.
AQI (PM 2.5) from 0-40 is termed as 'good', while AQI 50-100 is considered 'satisfactory' in the environmental parlance, the official said.
'Good' air quality means there is minimal impact of pollution while 'satisfactory' air can cause minor discomfort to people having breathing problems, the official said.
AQI in the air monitoring stations of the city hovered around 200 to 300 (poor) on Thursday and Friday, he said. The city's AQI crossed the 301 mark (very poor) on Wednesday, surpassing even that of Delhi's 275, he said.
Environmentalist S M Ghosh said while the air quality of the city improved by 90 per cent after the rain, the phenomenon of showers clearing air pollution is temporary.
"As the rain subsides, polluting particles from diesel vehicles, coal-based oven and dust from construction sites will invade the air again," he said.
The WBPCB official said several measures have been taken to contain air pollution, such as sprinkling water at construction sites, preventing plying of vehicles that are more than 15 years old and banning coal-based ovens at roadside food stalls.