Electronic waste leachates: A silent toxicological threat to aquatic life – Insights into biochemical and endocrine disruption mechanism in grass carp (Ctenopharyngodon idella) sub-adults

Electronic waste (e-waste) leachates pose a growing threat to aquatic ecosystems and public health. This study aimed to evaluate the sub-lethal toxic effects and underlying mechanisms of e-waste leachate exposure in sub-adults of Ctenopharyngodon idella. Sub-adults were exposed for 28 days to environmentally relevant sub-lethal concentrations (0.2, 0.5, 2, and 3 mg/L) of e-waste leachate. The results revealed dose-dependent decreases in testosterone, 17β-estradiol, protein, thyroxine, and tri-iodothyronine, alongside increases in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, cholesterol, and glucose levels compared to control and over the exposure period. Furthermore, histological examination (kidney and liver) indicates cellular damage and loss of structural integrity. Monte Carlo simulation further validated the physiological disruptions and toxic risk associated with e-waste leachate exposure. These findings highlight the stress-mediated toxicity of e-waste leachate in fish, emphasizing the urgent need for effective e-waste management to protect aquatic environments and public health.