Anlei Wei

Traditional monitoring frameworks heavily rely on static, total heavy metal concentrations and deterministic indices, failing to capture how climate-driven stressors and micro-interface interactions alter the stability, speciation, and bioavailability of toxic metals. This review synthesizes the state-of-the-art literature at the intersection of hydrology, geochemistry, microbial ecology, and toxicology to address this gap. We investigate how shifting redox (Eh-pH) gradients and climate-forced hydrological extremes—ranging from drought-induced sediment acidification to flood-driven shear stress—accelerate the reductive dissolution of iron/manganese oxyhydroxides. This process consequently triggers seasonal pulses of bioavailable metals. Furthermore, we evaluate how aged microplastics act as dynamic vector interfaces, altering competitive adsorption kinetics and biological uptake. Crucially, we highlight the heavy metal-microbiome-antibiotic resistance axis, demonstrating how sublethal metal exposure drives the co-selection and proliferation of antibiotic resistance genes (ARGs) via mobile genetic elements, revealing an indirect public health hazard. Finally, we critique deterministic assessments and advocate for probabilistic modeling via Monte Carlo simulations to capture exposure heterogeneity. By bridging macro-scale forcing with microscopic chemical and biological transformations, this review provides a comprehensive synthesis for shifting regulatory frameworks toward dynamic, bioavailability-based ecological governance.