IIT-Kgp studies impact of urban heat, air pollution on Kolkata future

Kolkata: Researchers at IIT Kharagpur have developed a scientific framework that integrates urban heat and air pollution exposure into a single health-risk indicator, offering a powerful tool for sustainable urban planning and climate-resilient city development.The study that was done with Delhi as test case, since it is the most polluted metro in the country, led to the formulation of an Urban Heat and Pollution Index (UHPI) that jointly assesses the combined effects of Urban Heat Island (UHI) intensity and multiple air pollutants, reflecting how these stressors interact and amplify risks for urban population.Led by Jayanarayanan Kuttippurath and VK Patel at the Centre for Ocean, River, Atmosphere and Land Science (CORAL) at IIT Kharagpur, the research, published in Case Studies in Chemical and Environmental Engineering, addresses a key limitation in conventional urban assessments, where heat and air pollution are typically analysed separately.“The study argues that this separation can underestimate real-world exposure because rapid urbanisation, rising anthropogenic emissions, and warming climate conditions increasingly produce simultaneous heat-pollution stress,” explained Kuttippurath.Applying UHPI to Delhi, the researchers identify clear spatial differences in combined risk. Central and eastern areas and parts of northwestern Delhi, including densely built and industrial zones, show higher UHPI values, indicating higher environmental stress and greater public health vulnerability. Greener and less densely developed peripheral areas show lower UHPI values, suggesting comparatively lower combined exposure and potential advantages for more sustainable urban expansion.Kuttippurath said a similar risk map was being prepared for Kolkata and would be ready by year-end or early next year. “The initial data indicates that a place like New Town is less environmentally stressed than suburban areas within the Kolkata Metropolitan Area with high population concentration and low green cover,” he said.The team will prepare such risk maps for other major cities like Mumbai, Chennai, Hyderabad, Bengaluru, Pune and Ahmedabad to outline integrated policy actions aligned with UHPI findings, including expanding green infrastructure, improving sustainable transport, reducing vehicular and industrial emissions, preserving open spaces, strengthening urban ventilation corridors, and adopting climate-sensitive planning.“Interventions targeting only temperature or only pollution can miss cumulative exposure and lead to underestimation of health risk,” the IIT prof said.The researchers position UHPI as a scalable decision-support tool for urban planners, public health agencies and policymakers, with potential application in both developing and developed cities to guide climate-resilient and health-focused urban development.WHAT IS UHPI?Urban Heat Pollution Index (UHPI) jointly assesses the combined impacts of multiple air pollutants and urban heat island effects on human health and urban sustainabilityWHT THIS MATTERSEvidence-based urban planning: Helps city planners identify high-risk zones and prioritise low-risk, green and well-ventilated areas for developmentPublic health protection: Supports health risk assessment and better preparedness against compounded heat and pollution exposureStrong policy support: Empowers policymakers, public health authorities and environmental agencies with a powerful decision-support toolGlobally applicable: The UHPI framework is scalable and adaptable for cities across developing and developed nations worldwide