Lithium consumption has surged dramatically since 2010, primarily driven by the boost of high-tech devices like mobile phones and laptops, as well as the increasing adoption of Li-ion batteries for electric vehicles and energy storage systems. Among all metals, lithium exhibits the most significant growth in demand over the past 15 years. Consequently, current lithium consumption already surpasses the natural oceanic input from rivers, while recycling rates remain notably low (less than 5% globally). Recent studies have documented instances of lithium pollution in riverine systems, raising concerns about potential contamination of littoral zones, which serve as the ultimate sink for various pollutants. At the interface between continents and the ocean, littoral environments provide critical ecosystem services and their natural biodiversity is exceptional. While microplastics, organic pollutants and other trace metals such as Cu, Hg, and Zn have been widely monitored and investigated in ecotoxicological studies, lithium has received little attention yet. To address this emerging issue, the ERC SeaLi2Bio project investigates the biogeochemical cycling of lithium in coastal environments and assess its potential risks for marine species and human health. We develop new and automated geochemical and isotopic techniques for measuring Li levels and Li isotopes in environmental, biological and marine samples, using last generation TQ-ICP-MS and MC-ICP-MS instruments. Lithium contamination and its recent evolution is determined on different continents through the study of estuarian waters and sentinel species. Ecotoxicologists experimentally determine Li bioaccumulation rates in coastal species and seafood. Biologists work on the Li transfer in cells and in tissues and identify the role of membrane transporters at play in marine species. Modelers use environmental and biological data to anticipate Li environmental risks related to future consumption and recycling scenarios. By combining these approaches, we aim to quantify the extent of lithium pollution in coastal ecosystems, identify vulnerable species and habitats, and predict future trends. Our findings will provide crucial insights for developing effective strategies to mitigate the environmental risks associated with lithium and ensure the sustainability of coastal ecosystems facing increasing anthropogenic pressures.
