Metabolic Capacity and Oxidative Status Alterations Induced by Lithium Exposure Gradient in Venerupis Corrugata

Abstract

Coastal areas are among the most threatened aquatic ecosystems, as a variety of daily-use substances reach these environments posing wildlife at risk. Facing the current global demand for green energies and clean technologies, lithium (Li) has been widely used in the production of batteries for electronic devices, electric or hybrid vehicles as well as for renewable energy storage systems. Annual growth of 30 % is expected for the Li market, however, Li recycling and treatment are still inefficient, so it is considered an emerging pollutant. The aim of the present research was to evaluate the biochemical effects of Li in the clam Venerupis corrugata. Clams were exposed under laboratory conditions to an increasing Li gradient (0, 200, 400, 800 µg/L) for 14 days. Bioaccumulation capacity decreased with increasing Li exposure possibly due to efforts to prevent damage by avoiding higher Li accumulation. No influences on clams’ metabolic capacity and energy reserves were observed. Antioxidant and biotransformation defences were activated, especially at 400 and 800 µg/L of Li, avoiding lipid damage while protein injuries were observed at higher concentrations. Furthermore, a loss of redox balance was observed. This study demonstrated clear negative effects in V. corrugata exposed to higher Li concentrations, highlighting the importance of preventing and regulating Li discharges into the environment, avoiding adverse consequences on the clams’ population and, ultimately, on the ecosystem.

Keywords: E-waste, Bivalves, Pollution, Biochemical markers, Oxidative stress