AQI worsens, Ballygunge, Salt Lake in ‘poor’ range
Times of India | 17 October 2024Among the city’s eight continuous ambient air quality monitoring stations (CAAQMSs), Ballygunge and Salt Lake reported the worst air quality, with its AQI consistently exceeding the 201 mark, categorizing it as ‘poor.’ In contrast, the other seven stations recorded moderate air quality. This shift marks a departure from the summer and monsoon seasons when Kolkata's air quality remained ‘good’ (0-50) and ‘satisfactory’ ( 51-100).
This dip in AQI typically signals the beginning of a gradual decline that reaches its peak during Diwali. The post-Diwali period often sees pollution levels climb steadily through winter, making the air increasingly unbreathable.
Kolkata's pre-winter spike in pollution mirrors trends observed across the Indo-Gangetic Plain (IGP), where pollutants accumulate and travel along the valley, eventually reaching Bengal.
The situation worsened on Wednesday due to persistent cloud cover, which reduced vertical wind flow, causing an atmospheric phenomenon conducive to a spike in air pollution. In winter, there will be an inversion of the planetary boundary layer, trapping pollutants near the ground, leading to a buildup that exacerbates the city’s air quality.
A capping inversion occurs when a layer of cooler air overlays a warmer layer near the earth's surface, reversing the typical atmospheric temperature profile. This phenomenon prevents the warm air — and the pollutants within it — from rising, causing them to remain at ground level, thus degrading air quality.
As winter approaches, experts warn that unless measures are taken to control emissions, Kolkata’s AQI could deteriorate further, posing serious health risks to its residents.
