“…One group of relevant contaminants is the rare earth elements (REEs), which are released into the environment due to their increasing usage, e.g., in high-technology electronic devices . Main anthropogenic sources of REEs to natural waters are mining, , medical applications, , and electronic wastes and their recycling. , The total REE concentrations at contaminated mining sites are reported to reach up to 80 μM. − Ecotoxicological effects of REEs, such as stress reactions in plants as well as health effects on animals and humans, have been demonstrated previously. ,, In addition, REEs have a typical oxidation state of +III and serve as analogues for trivalent actinides (Pu, Am, Cm) in various studies. − Here as well, the actinides’ interaction with mineral surfaces is of particular interest, , which needs to be understood for making critical decisions in selecting deep geological repository sites for radioactive waste …”