Ingestion and accumulation of microplastics in small marine fish and potential human exposure: case study of Binh Dinh, Vietnam

The present study investigates microplastic (MP) accumulation in five small marine fish species living in the nearshore sea of Binh Dinh, Vietnam that are commonly consumed by the local coastal communities. Fish (Oxyurichthys ophthalmonema, Stolephorus commersonnii, Decapterus macrosoma, Upeneus moluccensis, Sardinella gibbosa) were collected from four sites in the nearshore sea of Binh Dinh in rainy and dry seasons. The temporal, spatial, and species variations in MP accumulation were evaluated to understand environmental exposure of MPs to fish and potential human exposure to MPs via fish consumption. Microplastics of different types, sizes, and colors were found in the digestive system of the fish species. Microplastic composition included polyethylene, polyvinyl ether, polymethacrylate, polydichloroethylene, polydivinyl ester, poly ester, polyfluoroethylene, and other additives of plastic materials. Microplastic abundance in the fish was dependent on species, site, and season. Overall, microfiber was the dominant MPs. The average total MP abundance range was 4.70–23.80 particles/fish or 0.29–6.21 particles/g fish. There were statistically significant differences in MP abundances between fish species, sites, and seasons. The presence of MPs in the digestive system of fish suggests that MPs are in the nearshore environment of Binh Dinh. The local communities along the coast of Binh Dinh can ingest MPs from consuming small fish at a weekly rate equivalent to one five-hundredth number of rice grains they consume/week.