Cellular responses of Ruditapes philippinarum clams to global changes: Assessing the risks of rising temperatures and E-waste

Electronic waste (E-waste) has become a significant environmental challenge in recent decades due to the rapid increase in electronic device production and the subsequent disposal of obsolete products. E-waste contains hazardous materials, including metals like chromium (Cr) and rare earth elements (REEs) such as terbium (Tb), which can leach into aquatic ecosystems and cause severe ecological damage. With global temperatures projected to rise due to climate change, the interaction between these contaminants and increasing temperatures could heighten risks to aquatic life. This study examines the combined effects of Cr and Tb on the biochemical and physiological responses of the Manila clam ( Ruditapes philippinarum ), a species commonly used as a bioindicator of environmental stress. Clams were exposed to Cr, Tb, and their mixture at two temperatures (18 and 21 °C) over 28 days to assess how warming influences metal toxicity. The overall biochemical response of the clams was evaluated using Principal Coordinate Ordination (PCO). The results showed that at 21 °C, the biochemical effects were significantly exacerbated, particularly with the inhibition of antioxidant and biotransformation enzymes compared to those exposed at 18 °C. This suggests that oxidative stress impaired the enzymatic activity of the clams, especially under simultaneous exposure to both metals. These findings highlight the increased risk of metal toxicity in a warming world, emphasizing the need for integrated management strategies that address both e-waste and climate change. By providing critical insights into the combined effects of contaminants and temperature, this research aims to inform more effective regulatory policies to protect aquatic ecosystems. • Higher impacts in clams exposed to metals combination. • Higher temperatures exacerbate metal toxicity, regardless of the treatment. • Inhibition of antioxidant and biotransformation enzyme activity at 21 °C. • No increase of lipid peroxidation at 21 °C, despite the lack of defenses. • At 21 °C, an advanced stage of lipid degradation may have masked oxidative damage.