Threats of Pollutants Derived from Electronic Waste to Marine Bivalves: The Case of the Rare‐Earth Element Yttrium

The production of electrical and electronic equipment waste (e‐waste) is increasing at an alarming rate worldwide. This may eventually lead to its accumulation in aquatic environments, mainly because of the presence of nonbiodegradable components. The rare‐earth element yttrium (Y) is particularly relevant because it is present in a wide variety of electro‐based equipment. Within this context, the present study investigated the biological consequences of anthropogenic Y exposure in Mytilus galloprovincialis. Mussels were exposed to Y (0, 5, 10, 20, 40 μg/L) for 28 days, and their bioaccumulation and biomarkers related to metabolism, oxidative stress defenses, cellular damage, and neurotoxicity were evaluated. The results revealed that tissue Y content increased at increasing exposure concentrations (though the bioconcentration factor decreased). At the lowest Y dosage (5 µg/L), mussels lowered their electron transport system (ETS) activity, consumed more energy reserves (glycogen), and activated superoxide dismutase activity, thus preventing cellular damage. At the highest Y dosage (40 μg/L), mussels reduced their biotransformation activities with no signs of cellular damage, which may be associated with the low toxicity of Y and the lower/maintenance of ETS activity. Although only minor effects were observed, the present findings raise an environmental concern for aquatic systems where anthropogenic Y concentrations are generally low but still may compromise organisms' biochemical performance. Particularly relevant are the alterations in energy metabolism and detoxification processes for their longer‐term impacts on growth and reproduction but also as defense mechanisms against other stressors. Environ Toxicol Chem 2023;42:166–177. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.