Di-(2-ethylhexyl) phthalate (DEHP) and microplastics (MPs) are emerging contaminants frequently detected in the marine environment. However, the influence of MPs on DEHP bioaccumulation and their combined effects on eco-environmental risks remain underexplored. Mytilus coruscus (M. coruscus) were exposed to DEHP (200.0µg/L), polystyrene (PS) (0.050, 0.50, and 5.0mg/L), and their combination at environmentally relevant concentrations for 15-day, followed by a 7-day depuration period. The amount of DEHP accumulation followed the order of digestive gland >gills >muscles >gonad, with PS dose-dependently amplifying DEHP bioaccumulation in digestive gland. The changes in antioxidant enzyme activity indicated disruptions in oxidative defense. Furthermore, metabolomic analysis revealed that PS and DEHP considerably altered the lipid, energy, and citric acid cycles in digestive gland and gonad. Post-depuration analysis showed combined exposure resulted in persistent effects. Compared with single exposures, combined exposure had a greater adverse effect on the metabolism of essential amino acids, fatty acids, and volatile compounds, potentially influencing edibility and nutritional value of M. coruscus. This study underscores cumulative eco-environmental toxicity of PS and DEHP toward M. coruscus and highlights the potential increased risks of co-pollution.
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