Polystyrene microplastics increase uptake, elimination and cytotoxicity of decabromodiphenyl ether (BDE-209) in the marine scallop Chlamys farreri

Abstract Microplastics are a growing problem in marine environments due to their ubiquitous occurrence and affinity for chemical pollutants. However, the influence of microplastics on the uptake, depuration and toxicity of decabromodiphenyl ether (BDE-209) in marine organisms is unclear. We expose the marine scallop Chlamys farreri to polystyrene microplastics (PS; 125 μg/L) combined with BDE-209 (10 and 100 μg/L) to determine their toxicokinetics, cellular toxicity and histopathological effects. The results showed that PS acted both as a carrier and scavenger for the bioaccumulation of BDE-209. Importantly, the carrier role of PS was greater than scavenger one. PS increased the negative effect of BDE-209 (100 μg/L) on hemocyte phagocytosis, and ultrastructural changes in gills and digestive gland of scallops due to their carrier role for the bioaccumulation of BDE-209. However, PS did not increase the DNA damage of BDE-209 on the hemocytes. These findings are evidence of microplastics transferring adsorbed pollutants to marine organisms, and increasing their toxicity.