The translocation pathways of rare earth elements from the environment to the food chain and their impact on human health

Rare earth elements (REEs) have been increasingly exploited for crucial new technologies, and their massive use in the past decades has significantly increased their environmental concentrations. In this article, we have tried to answer the question as to whether or not the wide use of REEs, including nanoparticles, in agriculture and medicine may pose a health risk to the population through diet. For this reason, information on their biological role and potential toxicity to living organisms has been summarised. The fate of REEs in the aquatic and terrestrial environment, such as surface water, soil, soil-plant systems and animals, was described. Particular emphasis was placed on their uptake by plants and animals, translocation between species and thus their entrance into the human food chain. For a better understanding of REEs bioavailability and toxicity, their physicochemical properties, such as e.g. solubility, oxidation state, chemical form, and coordination with ligands are discussed. Data on the estimated daily intake and the presence of REEs in the human body were also compiled. In our concluding remarks we identified gaps in knowledge about the impact of REEs on the population through diet and predicted future research needs in this area.