Microplastic pollution profile of Mediterranean mussels (Mytilus galloprovincialis) collected along the Turkish coasts

Plastics profoundly threatens ecological balance in marine ecosystems across the globe in the current era of industrialization. Microplastics (MP), in particular, can pose risks reaching humans through the food web via various marine organisms. Among these organisms, since they are consumed as a whole, mussels are vital vectors of MP transfer during human consumption. Hence, here we analyzed MP pollution in Mediterranean mussel (Mytilus galloprovincialis) sampled from 23 different locations all along the Turkish coasts of the Black Sea, Sea of Marmara, and the Aegean Sea. After digestion of the mussels with HO, the micro-particles were determined under a stereomicroscope and characterized by confirming with FTIR analyses. 48% of the sampled mussels were found to have MPs. The average MP abundance was 0.69 item/mussel and 0.23 item/g fresh weight (fw) of soft tissue. Morphology was ordered as follows: fragments (67.6%)> fibers (28.4%)> films (4.05%). The dominant size of MPs was detected less than 0.5 mm (26.58%). 12 different polymers have been identified by FTIR and PET (32.9%), PP (28.4%), and PE (19.4%) were found to constitute 80% of the total MPs. The annual average exposure amount for mussel consumers in Turkey was estimated as 1918 MPs item/per year. Even though international organizations such as FAO, JECFA, or EU have not declared permissible limits, our data may inform human health uptake of MP ingestion via mussels. This data might also serve as a reference data-set for further MP monitoring research in Turkish and European Seas.