Kolkata: In a major step to address transboundary air pollution, the Union government has approved the adoption of an airshed approach covering eight states across the Indo-Gangetic Plain (IGP), including West Bengal.
The World Bank will lead the initiative.
The move is expected to help curb air pollution in Bengal, where a study initiated by the West Bengal Pollution Control Board and conducted by IIT Delhi identified the inflow of dust particles from neighbouring states such as Bihar, Jharkhand and Uttar Pradesh as a major contributor to poor air quality. The study found that such transboundary pollution accounts for nearly 53 per cent of the state’s total pollution load. The School of Atmospheric Sciences in Delhi has also noted that dust from the IGP easily travels across state borders, significantly aggravating air pollution in Bengal, particularly during the winter months.
Explaining the meteorological dynamics, environmental expert Kalyan Rudra said that during the monsoon, south-west monsoon winds flow from the Bay of Bengal through the Bengal delta towards north-western states such as Uttar Pradesh, Bihar and Delhi.
“From October–November, the air circulation reverses and the polluted air mass moves back towards the Bay of Bengal. This is why in-situ measures alone will not work,” Rudra said. Addressing a discussion on ‘India for Clean Air’, organised by the SwitchOn Foundation, Rudra said experts have advised an airshed-based strategy covering the entire IGP, bounded by the Himalayas in the north and the Peninsular region in the south.
“During winter, air descends and stagnates. Therefore, an airshed approach involving eight states is essential to address pollution in Kolkata. That collaboration has recently begun under the leadership of the World Bank,” he said.
Rudra added that while anthropogenic sources such as industry and transport can be regulated through pollution-control measures, meteorological factors remain beyond human control. “In winter, lower wind velocity, falling temperatures and reduced ventilation coefficient lead to higher pollution levels. The airshed approach is necessary to prevent pollution generated in one state from affecting another,” he said.
A coordination committee has already been formed to manage air quality across the pollution-prone IGP. It includes six states—West Bengal, Bihar, Haryana, Jharkhand, Punjab and Uttar Pradesh—and two Union Territories, Delhi and Chandigarh.