Combined exposure of the bivalve Mytilus galloprovincialis to polyethylene microplastics and two pharmaceuticals (citalopram and bezafibrate): Bioaccumulation and metabolomic studies

Pharmaceuticals and microplastics constitute potential hazards in aquatic systems, but their combined effects and underlying toxicity mechanisms remain largely unknown. In this study, a simultaneous characterization of bioaccumulation, associated metabolomic alterations and potential recovery mechanisms was performed. Specifically, a bioassay on Mediterranean mussels (Mytilus galloprovincialis) was carried out with polyethylene microplastics (PE-MPLs, 1 mg/L) and citalopram or bezafibrate (500 ng/L). Single and co-exposure scenarios lasted 21 days, followed by a 7-day depuration period to assess their potential recovery. PE-MPLs delayed the bioaccumulation of citalopram (lower mean at 10 d: 447 compared to 770 ng/g dw under single exposure), although reaching similar tissue concentrations after 21 d. A more limited accumulation of bezafibrate was observed overall, regardless of PE-MPLs co-exposure (
This work was supported by the Spanish Inter-Ministerial Science and Technology Commission through the ‘PLAS-MED’ (CICYT, CTM2017–89701-C3) and PHARMASEA (PCI2021-121933) projects and by the European Union through the European Regional Development Fund (ERDF). JM Castaño Ortiz acknowledges the predoctoral grant from AGAUR (2019 FI_B 00881REF). M. García Pimentel acknowledges the Spanish Ministerial Science, Innovation and University for her predoctoral fellowship (PRE2018-085502). The authors are grateful for funding from the CERCA Programme, Generalitat de Catalunya. The Ultra-Performance Liquid Chromatograph coupled to a triple Quadrupole hybrid Linear Ion Trap Detector (Acquity UPLC-MS QTRAP 5500, Waters-SCIEX) received support from the CERCAGINYS programme, funded by the Spanish Ministry of Science and Innovation. The authors thank the Platform of Non-Target Environmental Metabolomics (PONTEM) of the consortium facilities Montpellier Alliance for Metabolomics and Metabolism Analysis (MAMMA). The authors acknowledge the support of the Economy and Knowledge Department of the Catalan Government through a Consolidated Research Group (ICRA-ENV – 2021 SGR 01282).