Bioaccumulation of emerging contaminants in mussel (Mytilus galloprovincialis): Influence of microplastics.

Coastal environments are heavily influenced by human activities. Chemical substances considered as emerging contaminants (ECs) are one of the most important indicators of the anthropic influence on the environment, and they have recently shown to interact with microplastics (MPs). Mussels are suitable for in-lab bioacumulation studies providing insight about the occurrence and fate of contaminants in the organisms. In this study, bioacummulation of 20 chemical substances catalogued as ECs, including pharmaceuticals and personal care products (PPCPs), pesticides, and perfluoroalkyl substances (PFASs) in Mytilus galloprovincialis was assessed, with or without the influence of the presence of MPs. Mussels were distributed in three groups: control (B), exposed to ECs (C) and exposed to ECs and polyethylene MPs (C+M). The study was carried out for 58 days separated in two stages (i) exposure during days 0-28, and (ii) depuration during days 29-58. Visceral mass and haemolymph of the mussels were extracted separately, using QuEChERS and solid phase extraction (SPE), respectively. Then, extracts were analysed via UHPLC-MS/MS. Results showed that 3 PPCPs, 4 pesticides and 3 PFASs accumulated in visceral mass with bioconcentration factors (BCFs) ranging 6.7-15000 L/kg/d. In addition, 2 PPCPs, 2 pesticides and PFPeA were detected in haemolymph showing BCFs ranging 0.9-3.3 L/kg/d. When comparing C and C+M, MPs worked as a vector for the accumulation of the PFASs: PFOA, PFOS, PFDA and PFPeA; showing higher BCFs in the presence of MPs. Furthermore, the elimination of PFDA and PFOS was slower in the mussels exposed to MPs. On the other hand, the pesticides terbuthylazine and chlorpyrifos showed lower BCFs and more rapid elimination in the mussels exposed to MPs.