Potential trophic transfer of microplastics from marine to human food chain: preliminary study on commercial seafood from Tyrrhenian sea

The widespread distribution of microplastics in the marine environment has subsequently affected the aquatic biota including seafood for human consumption. An increasing number of reports document the ingestion of microplastics by fish species and their occurrence in the gastrointestinal tract (Efsa, 2016). Although demersal fish are usually eviscerated before consumption, both fresh and dried small fishes are often consumed as a whole (Renzi et al., 2019). This is the case of Engraulis Encrasicolus, a commercially important small pelagic fish species, which has been proposed as a small-scale indicator both of microplastic contamination in open waters and human exposure (Compa et al., 2018). E. encrasicolus (n.20 samples from the Tyrrhenian Sea) were collected. The gastrointestinal tract was removed and analyzed applying the microplastic extraction method, according to Avio et al. (2015) and Foekema et al. (2013). Then microplastic morphological and physical classification, and quantification analysis were carried out. Further FT-IR/RAMAN spectroscopy analysis should be carried out to identify the microplastic polymers of origin. As preliminary data, the application of the extraction method resulted in the efficient separation of microplastic from the organic tissues. Results showed the occurrence of fibers and plastic particles in the digestive tract of some fish samples. Seafood represents a considerable food vector for microplastic human exposure. Under the perspective of the human food chain, the microplastic trophic transfer and their bioaccumulation and biomagnification represent a serious issue to food safety (Efsa, 2016). Microplastics impact a high proportion of the wild E. encrasicolus caught in the Mediterranean Sea and their occurrence may be found also in other tissues than stomach contents. E. Encrasicolus as selective feeders specie may ingest microplastics as prey (Compa et al., 2018). Considering that anchovies composing the main diet for pelagic predators in the Mediterranean Sea, and their relevance for human consumption, further studies targeting levels of litter and microplastics in natural stocks are essential (Renzi et al., 2019). Traceability of the fate of microplastic in contaminated seafood is essential to assess their bioaccumulation and biomagnification in the marine habitat and the potential trophic transfer from marine to the human food chain.