Advancing Environmental Monitoring: Alternative Approaches for Assessing Bioavailable Trace Elements in Impacted Environments

Despite increasing focus on environmental contaminants such as microplastics and organic compounds, water pollution by trace elements remains a significant global challenge. While elevated concentrations of potentially toxic elements are generally related to anthropogenic activities, such as mining or industrial processes, natural hotspots can also be related to unique geological backgrounds. These elements, characterized by their toxicity, persistence, and bioaccumulation potential, pose long-term risks to ecosystems and human health. Therefore, understanding the complex biogeochemical cycles of these elements is crucial for effective environmental management.
European Water Framework Directive (WFD; 2000/60/EC) and other regulatory organizations often rely on conventional monitoring methods determining only the total concentrations of dissolved trace elements. This approach however provides limited information about the bioavailable fraction of these contaminants. To address these limitations, the scientific community has recognized the need for the development of alternative methods which could capture the bioavailable fraction of elements and thus obtain better evaluation of the ecotoxicological status of aquatic ecosystems. Recent studies demonstrate the undeniable benefits of in-situ determination of labile fraction of trace elements by passive sampling techniques. The most commonly used approach is the Diffusive Gradients in Thin Films (DGT) technique which directly discriminates and determines only the labile fraction of trace elements which consists of free ions and weak complexes.
Our research focuses on the development and application of the DGT technique in combination with geochemical modelling to assess the labile and potentially bioavailable forms of radio elements (uranium and radium) and other trace elements (arsenic, selenium, iron, cadmium, manganese,…) in anthropogenically impacted environments. Through our work, we aim to contribute to a deeper understanding of trace element biogeochemistry and apply this knowledge in the development of effective mitigation strategies. In this presentation, the challenges posed by trace element contamination, the limitations of conventional monitoring methods, and the potential of the DGT technique to provide valuable insights into the bioavailability and environmental risk of these elements will be addressed and demonstrated on case studies.