In 2024, Darjeeling may join six other non-attainment cities in state: Report
darjeeling: Darjeeling, the Queen of Hills, could soon become the only Hill station to feature in the list of non-attainment cities having failed to fulfill the national ambient air quality criteria. A non-attainment city is one whose air has failed to fulfill national ambient air quality criteria for at least five years.
The ground-breaking study, published in the journal “Atmospheric Environment” by Abhijit Chatterjee, Associate Professor at Bose Institute, Kolkata, has unveiled a startling revelation about the air quality in Darjeeling. Along with Chatterjee, the study, undertaken by Abhinandan Ghosh of the Indian Institute of Technology, Kanpur, and Monami Dutta of the Bose Institute, indicates that Darjeeling would soon be added to the list of 131 polluted cities non-attainment cities across India. “However, the list does not have any hill station so far. Darjeeling could be the first to be included if pollution goes unchecked and keeps on increasing at this rate,” stated Chatterjee, talking to Millennium Post. Currently, there are six such cities in West Bengal, where the level of air pollutants is much higher than the Indian standard. They are — Asansol, Durgapur, Kolkata, Howrah, Haldia and Barrackpore. The research, spanning from 2009 to 2021, focused on characterising PM10 levels (very small pollutant particles found in dust and smoke) in Darjeeling.
“The study was conducted at the Bose Institute, Darjeeling starting in 2009. Using a prediction model, we have projections till the year 2040,” stated Chatterjee. Researchers forecast that PM10 pollution in Darjeeling would surpass the national ambient air quality standards in 2024, reaching approximately 63 micrograms per cubic metre of air. It determined that summer (March-May) and winter (December-February) were the two seasons in Darjeeling when PM10 concentrations exceeded 70 micrograms per cubic metre of air, surpassing the Indian standard of 60 micrograms per cubic metre. The study shed light on the major sources of ultrafine particulate matter pollution in Darjeeling. During the summer, vehicular emissions from tourist activities contributed 33 per cent while biomass burning from roadside eateries accounted for 21 per cent.
Dust transport from the Indo-Gangetic Plain, coal combustion from eateries, domestic use, and the Toy Train, as well as secondary sources, also played a role.In winter, biomass burning for low-temperature requirements contributed 27 per cent, vehicular emissions constituted 25 per cent, and coal combustion accounted for 20 per cent, with dust and secondary sources contributing to the remainder.
The analysis revealed that the main cause of this high pollution was the ultrafine components of PM10, specifically PM1 (particulate matter less than 1 micron).
The study found a significant increase in PM10 levels since 2014 due to a rise in ultrafine particles. Overall, combustion activities, including diesel, petrol, coal, and biomass, were responsible for approximately 70 per cent of ultrafine particulate matter pollution and PM10 levels. Vehicular emissions alone accounted for over 90 per cent of PM10 in summer, while biomass burning contributed more than 80 per cent in winter. “These findings raise concerns about uncontrolled tourist influx, unplanned urbanisation, unauthorised land use, biomass and combustion activities, and the use of old vehicles and diesel-driven generator sets in Darjeeling,” added Chatterjee.
He said the study highlights the urgent need for attention from policymakers regarding the significant pollution load experienced in Darjeeling, a high-altitude Himalayan tourist destination in India.
“Despite its geographical, climatic, and ecological importance, Darjeeling has remained overlooked by policymakers. The study raises concerns that Darjeeling may soon become a non-attainment city, emphasising the necessity for central and state pollution control boards to establish robust and continuous monitoring stations for air pollutants in such regions.”
