What we cannot see often shapes what we experience. Emerging contaminants (ECs)—including PFAS, microplastics, pharmaceuticals, and pesticides—move through interconnected Earth systems, linking soils, waters, coasts, and communities. Their behavior is controlled by hydrologic connectivity, biogeochemical processes, and ecosystem dynamics, influencing exposure and risks to ecosystems and human health. This session focuses on the transport, transformation, and fate of ECs across the land–water continuum. We welcome studies examining biogeochemical controls (e.g., redox processes, mineral–water interactions, microbial activity) and hydrologic pathways that regulate contaminant mobility, persistence, and bioavailability. Emphasis is placed on integrating environmental processes with GeoHealth outcomes, including exposure, toxicity, and risk assessment. We encourage contributions using chemical and biological “omics” approaches, as well as AI and data-driven methods (e.g., machine learning, physics-informed models) to predict contaminant behavior and identify hotspots. Interdisciplinary studies, including field, lab, and modeling approaches, and those addressing climate impacts, are strongly encouraged.