Targeting key toxic nanoscale particulate matter for precision control of coal power emissions

Coal-fired power plants represent a major anthropogenic source of nanoscale particulate matter, yet conventional mass-based regulations overlook the distinct and potent health risks posed by specific components. Here we combine single-particle elemental profiles (169 plants across China) with cellular toxicity (human lung cells). Using interpretable machine learning, we reveal iron-rich nanoparticles as key toxic driver, explaining 27.4% of the observed oxidative stress and 16.9% of cytotoxicity. We then develop a high-resolution national inventory of iron-rich nanoparticles, estimating total emissions of 236 tons in 2020, with Eastern China as a hotspot contributing 38.2%. Tailored regional strategies could achieve a 77.5% reduction in national emission, with electrostatic precipitator upgrades identified as the most cost-effective measure. Our findings provide an actionable framework to advance air pollution policy beyond total emissions control toward component-specific reduction of the most toxic nanoparticles, ultimately mitigating their associated public health impacts. (Figure presented.)