12 Kolkata: Among six metro cities in India in terms of PM2.5 concentration (61 µg/m3) in the air during the first two weeks of November, Kolkata remained the fourth cleanest city and maintained ‘Moderate' air quality with an average PM2.5 level of 61 µg/m³. Delhi is the worst polluted city (243 µg/m3). Mumbai (62 µg/m3) closely follows Kolkata, while Chennai (28 µg/m3) emerged as the cleanest city, according to an analysis by Respirer Living Sciences, a climate-tech research organisation.
PM2.5 particles are about 30 times smaller than the width of a human hair. They can pass through the body's natural defences and enter the lungs and the bloodstream. Thus, the concentration of PM2.5 makes air fair or foul, particularly in winter.
Other industrial cities in Bengal like Asansol (95.2 µg/m³) and Durgapur (96.2 µg/m³) fell into the ‘Poor' and upper ‘Satisfactory' categories. The analysis covered major urban centres and industrial hubs, revealing a mix of Satisfactory and Poor air quality levels across the state. The findings indicate a clear divide between cities benefiting from effective urban management and those struggling with the impacts of industrial and vehicular emissions, experts opined. "These trends showcase the importance of region-specific strategies to tackle pollution," said Ronak Sutaria, founder and CEO of Respirer Living Sciences, adding thatthe mixed trends in Bengal demonstrate both progress and the need for immediate action. By focusing on industrial hotspots and urban infrastructure, the state can make significant strides toward cleaner air for all, he claimed.