Cancer risk from ambient formaldehyde air pollution exposure in India

Abstract Formaldehyde is a known air pollutant recognised for its risks associated with cancer due to prolonged exposure. This study examines the spatial and temporal variability of HCHO and related cancer risk in India using the high-resolution GEOS-Chem Chemical Transport Model for the year 2022. The findings indicate notable regional disparities in HCHO pollution in India, with higher levels in industrial centres, coastal zones and intense agricultural regions. The highest cancer risk associated with HCHO exposure is found in northern IGP, Northeast India and Kerala, where up to 81280 individuals per million may potentially develop cancer. Sensitivity assessment indicates that a 25% and 50% reduction in nitrogen oxide emissions lead to 2.60% and 6.74% reduction in cancer risks, respectively. The findings emphasize the need to regulate ambient HCHO pollution in India, where limited healthcare and expensive treatments make reducing emissions and air pollution essential to limiting cancer risks.