Kolkata air quality deteriorated into the “poor” category at Jadavpur on Sunday, with an AQI of 207 recorded at 2pm as cracker norms were reportedly flouted in several parts of the city and cooler weather reduced the dispersion of pollutants.
The reading was recorded by the automatic air quality monitoring station at Jadavpur and displayed on the National Air Quality Index prepared by the Central Pollution Control Board. An AQI between 201 and 300 is classified as “poor”, a level at which prolonged exposure can cause breathing discomfort to most people.
The National Air Quality Index represents the average air quality over the preceding 24 hours. An air quality expert quoted in the report said a higher AQI indicates greater pollution in the ambient air.
The deterioration followed reports of cracker use from Saturday afternoon. A resident near the 8B bus stand in Jadavpur alleged that widespread violations of noise norms began on Saturday, with the sound of banned crackers becoming more frequent through the evening. The law permits the use of green fireworks only between 8pm and 10pm on Sunday.
Other monitoring stations recorded air quality in the “moderate” category on Sunday afternoon. Ballygunge recorded an AQI of 184, Fort William 180, Victoria 138 and Bidhannagar 170. Rabindra Sarobar recorded an AQI of 119. The CPCB classifies AQI readings between 101 and 200 as moderate, a range that can cause breathing discomfort to people with lung and heart diseases.
Experts attributed the deterioration partly to the fall in temperature. Kolkata’s minimum temperature was nearing 20 degrees Celsius, and scientists said warmer conditions generally help pollutants disperse. Lower temperatures and wind speeds in the period leading into winter are less favourable for the movement and dilution of pollutants, allowing contaminants to remain concentrated closer to the ground.
The weather effect can make short-term emissions more consequential in a dense city. Pollutants released by fireworks and other sources may remain trapped near street level when the atmosphere is less conducive to dispersion. The report, however, does not identify the relative contribution of crackers compared with other pollution sources.
Doctors cautioned that prolonged exposure to polluted air could aggravate existing respiratory conditions. Saurabh Maji, a consultant pulmonologist and critical care specialist at Narayana Health — RN Tagore International Institute of Cardiac Sciences in Mukundapur, said patients with asthma or chronic obstructive pulmonary disease could experience worsening symptoms because of poor air quality.
Maji advised vulnerable people to avoid going outdoors where possible and to wear masks if they needed to step out. The latest monitoring readings and the reported cracker violations place the immediate public-health concern alongside the enforcement question: the permitted fireworks window and restrictions are meaningful only if violations are detected and acted upon across neighbourhoods.
