AQI ‘poor’ in four city zones, Fort William air quality worst
Times of India | 24 November 2024
123 Kolkata: As temperatures dip with the onset of winter, the city's air quality began to deteriorate, raising health concerns among residents. Four real-time Continuous Ambient Air Quality Monitoring Stations (CAAQMS) recorded ‘poor' air quality (AQI: 201-300), while three other stations are nearing the transition from ‘moderate' (AQI: 101-200) to ‘poor', at a time when the national capital, Delhi, is grappling with ‘severe' air pollution levels.
West Bengal Pollution Control Board (WBPCB) officials attribute the worsening air quality to temperature inversion, a common winter phenomenon where cooler air near the ground gets trapped under a layer of warmer air, locking pollutants closer to the surface.IPL 2025 mega auctionIPL Auction 2025 Live: KKR break bank for Venkatesh Iyer, Ashwin returns to CSKIPL 2025 Auction LIVE: Updated Full Team SquadsIPL Auction 2025: Who got whomThis atmospheric condition hinders pollutant dispersion, leading to increased exposure for city residents.
"The combination of calm winds, clear skies and long nights slows down the dispersal of pollutants. The warm air above prevents the cooler air below from rising, effectively trapping pollution near the ground," said a WBPCB officer.
The primary pollutant affecting the city's air quality is fine particulate matter (PM2.5), which is small enough to penetrate deep into the lungs and bloodstream. WBPCB experts warn that prolonged exposure to high levels of PM2.5 can have severe health implications, including respiratory and cardiovascular issues.
"PM2.5 is the dominant pollutant and its count largely determines the air quality. The higher the PM2.5 levels, the more hazardous the air becomes," an official said.
Among the seven CAAQMS locations, Fort William recorded the poorest air quality, while Jadavpur emerged as the cleanest on Sunday. Salt Lake, Ballygunge and Victoria, too, were in ‘poor' zone. However, stations like Rabindra Bharati University (B T Road) and Rabindra Sarobar are showing rapid deterioration, moving towards the ‘poor' AQI category.
The city's pollution woes are compounded by its geographical location at the tail end of the Indo-Gangetic Plain (IGP), one of the world's most polluted airsheds. Pollutants trapped in the valley during winter travel from north to south along the valley, affecting cities along the way.
Cities like Delhi, Gurgaon and Ghaziabad in the IGP are some of the world's most polluted. "Kolkata, being at the southernmost end, bears the brunt of trans-boundary pollution. This underscores the need for mitigation at the airshed level rather than relying only on city-specific plans, which have inherent limitations," said WBPCB chairman Kalyan Rudra.