For 1st time this season, AQI turns ‘poor’ in all 7 Kol stns
Times of India | 27 November 2024
123 Kolkata: City residents woke up on Tuesday to a thick layer of smog that lingered until late morning, reducing visibility and disrupting transportation across the city. While the Air Quality Index (AQI) slightly improved as the day progressed from ‘very poor' (301-400) to ‘poor' (201-300) for the first time this season, the lingering health impact raised significant concern, especially for those over 50.
The continuous ambient air quality monitoring stations (CAAQMSs) at Ballygunge and Fort William reported ‘very poor' air quality in the morning. Although Fort William's AQI dramatically improved as the day went on, Ballygunge saw only minor relief, with air quality moving from ‘very poor' to ‘poor' only late in the evening. Victoria Memorial and Salt Lake followed closely behind, with air quality remaining in varying degrees of the ‘poor' category.
Health experts cautioned against strenuous physical activities outdoors, emphasizing the heightened cardiovascular risk posed by inhaling pollutants. Preventive healthcare expert Debasish Basu said, "Kolkata's AQI is dominated by PM2.5 particles. Due to their small size, these particles penetrate deep into the lungs and bloodstream, carrying harmful chemicals that exponentially increase health risks."
The PM2.5 particles, a key component of Kolkata's air pollution, pose a severe threat as they bypass natural defences in the respiratory system. Prolonged exposure can lead to respiratory and cardiovascular complications, with senior citizens being particularly vulnerable.
The Central Pollution Control Board (CPCB) and the Indian Council of Medical Research (ICMR) classify AQI into five categories based on health impacts — good (0-50: typically during summer and monsoon in Kolkata), satisfactory (51-100: common post-monsoon), moderate (101-200: common in Oct and early Nov), poor (201-300: emerges with falling temperatures in late Nov), very poor (301-400: prevails in Dec) and severe (401-500: rare in Kolkata, but Delhi currently struggles under this level).
Meteorological factors such as slow wind speeds (below 2 metres/second) and temperature inversion have contributed to the rise in pollution levels, said Kalyan Rudra, chairman of the West Bengal Pollution Control Board. "A sustained cloud cover and low wind speed create conditions for pollution to accumulate. Moreover, the trans-boundary movement of pollutants from neighbouring regions adds to the challenge," Rudra added.
He emphasized the need for regional rather than city-specific mitigation measures, highlighting how inter-state coordination could better address pollution.