Kolkata started the new year with its foulest air of this season, as midnight firecracker celebrations pushed pollution levels deep into the ‘poor’ and ‘very poor’ categories. The spike came at a time when winter conditions tend to trap pollutants close to breathing height, worsening their impact.
Winter weather worsens pollution impact
This marginal relief came from a light breeze that helped disperse some of the pollutants to prevent air quality from slipping further. As per a report by The Times of India, however, the experts said that the effect of fireworks was far more damaging than during Diwali because of prevailing winter conditions.
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According to the report by Times of India, while the extent of firecracker use was smaller than during Diwali, scientists pointed out that winter chill causes thermal inversion - a meteorological phenomenon that restricts vertical air movement and traps pollutants near the ground.
"During winter, firecracker revelry is suicidal as far as air pollution is concerned. Low ground temperature causes thermal inversion, suppressing vertical wind movement. Wind speed often drops below 2 metres per second, allowing pollutants to accumulate near the surface", Times of India quoted a scientist from West Bengal Pollution Control Board (WBPCB) as saying.
AQI readings slip into ‘very poor’ category
By noon, two air-quality monitoring stations in the city recorded 'very poor' air -AQI 301-400-just one notch below the 'severe' category. Five other stations reported 'poor' air quality, AQI 201-300.
Jadavpur fared the worst, with an AQI of 314, matching the levels witnessed in Delhi during the peak of its recent smog crisis, even as the national capital showed signs of recovery. Salt Lake came a close second with an AQI of 308, while Victoria Memorial almost reached the very poor limit at 292.
Just a day earlier, air quality at Jadavpur was 159 and at Salt Lake was 154, both within the moderate range.
Pollution may worsen in coming days
As per the report by The Times of India, experts had warned that the air quality would improve incrementally. Since the cold conditions are likely to persist, pollution from successive days could accumulate in the lower atmosphere and further deteriorate air quality. Environmentalists cited serious health concerns, especially among children, senior citizens, and those with respiratory ailments, and called for stricter enforcement and greater public awareness in future celebrations.
Also Read | Dense fog, cold wave grip Delhi as AQI stays ‘very poor’; flights affected
Noise pollution norms flouted across the city
The night saw widespread violation of noise pollution norms. Noise levels crossed the 80-decibel mark at several residential and silent zones, nearly double the permissible limit for nighttime.
Noise levels at Jadavpur University, a declared silent zone, peaked at 84.1 dB. Similarly, at Flora Fountain, a residential area, the reading touched 81.5 dB shortly after midnight.
A number of educational institutions, which are designated to be a silent zone, reported noise levels between 70 and 80 dB. The permissible limit for residential areas is 45 dB, while for a silence zone it is 40 dB, Times of India reported. Apart from high-decibel firecrackers, loudspeakers sans sound limiters and DJ music were used extensively.
