Canned seafood as a potential source of microplastics exposure with taxon-specific partitioning and packaging-derived...

Despite extensive documentation of microplastics (MPs) contamination in fresh seafood, canned marine products-a substantial fraction of global aquatic food-remain conspicuously underinvestigated. Here, we elucidated the contamination profiles of μ-FTIR-identifiable MPs (>50 μm) in solid tissues and surrounding liquid media of eight commercially popular canned seafood products in China, including three fish (Cirrhinus molitorella, Thunnus thynnus, and Trichiurus lepturus), three bivalves (Paphia undulata, Crassostrea gigas, and Argopecten irradians), and two shrimp (Procambarus clarkii and Litopenaeus vannamei). Quantitative analyses revealed a 46.3% detection frequency for MPs, yielding an overall mean abundance of 0.11 ± 0.14 items/g (10.36 ± 2.03 items/can), characterized by comparable mean loads between solid tissues (0.05 ± 0.11 items/g) and the surrounding broths (0.07 ± 0.10 items/g). MPs distribution exhibited pronounced taxon-specific heterogeneity: fish showed higher MPs loads in broths than in meat, bivalves showed the contrary, and shrimp exhibited minimal contamination. The recovered MPs predominantly comprised polyethylene terephthalate (PET) and polyacrylonitrile (PAN). Notably, phenoxy and epoxy resin MPs, which were also identified in the internal can coatings, accounted for 13.3% of the total MPs detected in canned samples, and MPs abundance was positively correlated with sodium ion concentration. Dietary exposure assessments indicate that under scenarios simulating routine solid consumption (with naturally adhering broth retained), the annual per capita MPs intake among the Chinese demographic is 12.83 items (0.20 and 0.31 items/year/kg for adults and minors, respectively). However, the complete ingestion of the residual intra-can broth escalates this exposure to 27.89 items (0.43 and 0.67 items/year/kg, respectively). This study indicates that canned seafood represents a route of human MPs intake, with food processing and packaging as potential contamination sources that merit consideration in food safety evaluations.