Rare Earth Elements, Oxidative Stress, and Disease

Rare earth elements (REEs), as members of the f-block in the periodic table, including also yttrium and scandium, benefit from a series of unique physical and chemical properties, making them indispensable for a number of critical technologies ranging from catalytic fuel additives, medical imaging, wireless power tools, supermagnetic alloys, screen display, and fiber optics. Nevertheless, there are many environmental issues associated with mining, isolation, recovering, and recycling of REEs. A few reports indicate that the chemicals used in the refining process have been involved in REE bioaccumulation and pathological changes of local residents. Given the recent toxicological results on REE exposures, it seems most urgent to elucidate the mechanisms of REE-associated damage. An established action mechanism in REE-associated effects relates to modulating oxidative stress, as a result of the high redox potential exhibited by the couple REE3+/REE2+. The redox behavior of REEs is also influenced by different factors such as pH, oxic/anoxic conditions, making REEs in some cases process tracers in a variety of natural waters, including fresh groundwaters, lakes, rivers, estuaries and oceans, and sediments. Starting from this evidence, this chapter will offer a survey on the roles of REEs on the onset of the cellular oxidative stress by discussing data reported in the literature about the impact of REE exposure of cells, animals, and plants on the levels of some of the most common enzymatic and non-enzymatic oxidative stress markers.