Microplastics in seafood: identifying a protocol for their extraction and characterization

International audienceThe pollution of the oceans by microplastics (< 5mm) is a worldwide challenge, and they have been recovered from several marine vertebrates and invertebrates. From an ecotoxicological point of view, the ingestion of microplastics by a wide range of marine organisms leads to substantial impacts on major physiological functions. More specifically, concerning seafood for human consumption, microplastics could be considered as contaminants and very few studies have been conducted to date on the possible consumer exposure to microplastics. The important preliminary step is to use a recovery method that can efficiently digest different type of matrix, while preserving polymers integrity to allow a reliable identification in a cost- and time-effective way.In the present study, 6 different existing approaches using acidic, basic, enzymatic or oxidizing solutions were reviewed and compared. Their effects on 15 different plastic polymers were studied, including the main produced polymers: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyurethane (PUR), polystyrene (PS) and polyamide (PA). Afterward, selected methods were screened based on their efficiency in digesting biological matrices (mussels, crabs and sea bream). Effects on plastics were evaluated through visual inspection, weighing, Pyrolysis-GC/MS and Raman micro-spectrometry analyses before and after digestion, while digestion efficiency was assessed after filtration on GF/A 1.6 μm glass fiber filters and observation using a binocular microscope. The aim is to identify and a unique protocol that could be implemented to insure relevance and comparison of studies on this topic, as requested by OSPAR and MSFD