Air quality and health benefits achievable by mitigating Indian coal-fired power plant SO2 emissions

Sulfur dioxide (SO 2 ) emissions from coal-fired power plants (CFPPs) are a major precursor of secondary fine particulate matter (PM 2.5 ), which has adverse health impacts. In India, the number of CFPPs has increased in recent decades. However, the potential air quality and health benefits of fully mitigating these SO 2 emissions remain poorly explored. Here, for the first time, we estimate reductions in ambient PM 2.5 and SO 2 concentrations by conducting nested regional chemical transport model simulations, integrated with a novel satellite-derived CFPP-SO 2 emission catalogue. We find that India could reduce ambient PM 2.5 exposure by 0.3-12 µgm -3 annually through mitigation of CFPP-SO 2 emissions, preventing 124,564 (95% uncertainty intervals: 103,388-145,740) deaths annually. Additionally, the states could reduce ambient SO 2 levels by 0.1-13.6 ppb, with males, people from other backward classes, and deprived subgroups expected to experience greater air quality and health benefits than their demographic counterparts. This study emphasises the urgent need to mitigate Indian CFPP-SO 2 emissions, particularly in regional hotspots where CFPP contributes significantly to ambient PM 2.5 to achieve substantial improvements in air quality and public health and disparity in health benefits.