From mercury to plastics: Earth system science and governance strategies

Abstract Mercury and plastics are emblematic pollutants of the Anthropocene. Despite differences in material properties, transformations, and exposure pathways, they share features in cross-compartment transport and long-term persistence. Drawing on decades of research and the Minamata Convention, mercury science has established coordinated observations, source inventories, and mass-balance models. Here, we assess how elements of this infrastructure can inform plastic pollution research by comparing source–transport–sink dynamics and identifying where mercury-based approaches are suitable for adaptation. We argue that socioeconomic analysis should be integrated with Earth system modeling to trace plastic fluxes from human technospheres to environmental sinks. Priorities include harmonized methods, sustained observations, transparent release inventories, and models that evaluate policy effects on sources, transport, transformation, exposure, and accumulation. This comparison is methodological, not mechanistic, and supports a science–policy interface for plastics governance.