Microplastics in seafood: Navigating the silent health threat and intestinal implications through a One Health food safety lens

This systematic review revealed microplastic (MP) contamination and conducted hazard risk assessment in various seafood species of different geographic locations. Evidence was available on fish, crustaceans, and mollusks, with most studies from China reporting 19 seafood species containing the highest variety of total MP polymers. The maximum percentage of MPs in terms of size, composition, shape, and color was attributed to 100-1500 µm, polyethylene terephthalate (PET), fibers, and blue color, respectively. Aquatic life in brackish and marine ecosystems harbored higher levels of MPs than freshwater organisms. Crustacean species Thenus orientalis (flathead lobster) off the coasts of Iran were the most heavily loaded with 460.2 MPs/individual. Meta-analysis revealed high statistical and model heterogeneity of MP content in fish (mean 1.11 MPs/individual, 95 % confidence interval (CI)= 0.3-1.92) and shellfish (1.43 MPs/individual, 95 % CI= -0.35-3.21). The highest MP contamination factor (CF) was estimated in marine carnivorous Plectropomus leopardus (leopard coral trout) from Australia/Fiji (CF= 3.06), omnivorous Portunus sanguinolentus (three spot crab) from India (CF= 5.44), and filter-feeding Chlamys nobilis (noble scallop) from China (CF= 3.38), with the highest pollution risk index (PRI) values of 366877.6, 46437.5, and 45672.2, respectively. Studies show that MPs are potential triggers of altered key microbial diversity of Firmicutes, Fusobacteria, Proteobacteria, Actinobacteria, and Bacteroidetes. The dysbiotic properties of MPs increased intestinal permeability and decreased immune system associated with inflammation. In summary, this study provides a significant understanding of the MP abundance in edible seafood species and knowledge of MP risk assessment important to safeguard food safety and human health.