Redefining the Health Risk of Battery Materials Through a Biologically Transformed Metal Mixture

The global transition to electric vehicles hinges on lithium-ion batteries, yet the health risks of their core components, such as nickel-manganese-cobalt (NCM) cathodes, remain a critical and misunderstood gap, threatening a truly sustainable energy transition. Herein, we reveal that inhaled NCM particles undergo sustained lysosomal dissolution, transforming into metal mixtures whose composition mirrors the parent material. Crucially, we decipher the unique toxicological interactions within this biologically generated mixture-antagonism from Ni/Co and synergy from Mn. This fundamental discovery of NCM's biological fate unlocks accurate risk assessment. Building on this mechanistic insight, we identified the Integrated Addition and Interaction (IAI) model as the framework capable of capturing complex interactions. Applying this model to real-world exposure data uncovers moderate yet significant population-level health risks. Our work establishes a transformative, evidence-based paradigm that connects in-body material transformation to real-world health outcomes, providing the scientific foundation to ensure that the clean energy transition is not only green but fundamentally safe for human well-being.