Cadmium (Cd) is a pervasive environmental contaminant entering ecosystems via natural and anthropogenic sources, accumulating in soils and plants, and transferring through food webs to humans primarily via diet. This review synthesizes recent field data on Cd concentrations and trophic transfer in aquatic and terrestrial ecosystems, examining their alignment with legal maximum limits (MLs) and health-based guidance values. Evidence from freshwater and coastal lagoons shows clear Cd biomagnification in specific epiphyte-based and benthic food chains, whereas marine pelagic fish often exhibit low muscle Cd concentrations, limiting biomagnification. In terrestrial systems, Cd bioaccumulates strongly in soil invertebrates and small mammals, with mixed outcomes for livestock tissues depending on grazing conditions. Human exposure via diet approaches or exceeds tolerable intake values linked to adverse renal and systemic effects at low body burdens, prompting calls for stricter regulatory standards. Monitoring programs reveal compliance challenges especially in cephalopods, indicating key risk points in commercial seafood chains. Findings highlight the complexity of Cd trophic dynamics, tissue-specific accumulation, and the importance of integrating ecological, regulatory, and toxicological perspectives for managing Cd risks in food webs and human health.
