Kolkata, May 26 : Darjeeling, often termed as the "Queen of hill stations," is facing the threat of joining six other non-attainment cities in West Bengal not fulfilling national air quality criteria for at least five years, as per the findings of a recent report. According to a study paper by Dr Abhijit Chatterjee, Associate Professor at Bose Institute, Dr Abhinandan Ghosh of the Indian Institute of Technology (IIT) Kanpur, and Monami Dutta of the Bose Institute, Darjeeling would soon be added to the list of 131 polluted cities discovered across the country. The study paper has been in the journal "Atmospheric Environment". Currently, there are six such cities in West Bengal, where the level of air pollutants are much higher than the Indian standards. They are Asansol, Durgapur, Kolkata, Howrah, Haldia and Barrackpore. "The research, spanning from 2009 to 2021, focused on characterising PM10 levels in Darjeeling. 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 analysis revealed that the main cause of this high pollution was the ultrafine components of PM10, specifically PM1 (particulate matter less than 1 micron)," as per the report. According to Dr Chatterjee, there is an urgent need for attention from policymakers regarding the significant pollution load experienced in Darjeeling. "Despite its geographical, climatic and ecological importance, Darjeeling has remained overlooked by policy makers," he added. Dr Ghosh said that projections raise serious concerns as PM10 levels are expected to exceed 105 in summer and 90 in winter. "Moreover, ultrafine particulate matter (PM1) is predicted to approach 50 micrograms per cubic metre of air, surpassing the Indian standard for PM2.5 (40 micrograms per cubic metre). This level of pollution would place Darjeeling on par with many polluted cities in the Indo-Gangetic Plain region and other urban areas of India," he added. /IANS