Abundance and characteristics of microplastics in market bivalves from South Korea

• Published in: Environmental pollution (1987) Vol. 245; pp. 1107 - 1116
• Main Authors: Cho, Youna, Shim, Won Joon, Jang, Mi, Han, Gi Myung, Hong, Sang Hee
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2019
• Subjects: Animals; Bivalves; Contamination; Crassostrea - chemistry; Environmental Monitoring - methods; Fisheries; Food Contamination - analysis; Humans; Market survey; Microplastics; Mytilus edulis - chemistry; Plastics - analysis; Republic of Korea; Seafood; Seawater - chemistry; Shellfish - analysis; Water Pollutants, Chemical - analysis; Republic of Korea; Seafood; Microplastics; Bivalves; Market survey; Contamination
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2018.11.091

Microplastic contamination in marine organisms is a growing environmental issue with implications for seafood safety. Among marine organisms, shellfish are considered to be an important route of human exposure to microplastics because they filter a large volume of seawater while feeding and, thus, accumulate microplastics from seawater; furthermore, they are consumed whole, without gut removal. In this study, a market survey was carried out to understand microplastic contamination in domestic bivalves sold in fishery markets in three major cities of South Korea. Four popular bivalve species, oyster (Crassostrea gigas), mussel (Mytilus edulis), Manila clam (Tapes philippinarum) and scallop (Patinopecten yessoensis), were selected as monitoring species, which together account for 79–84% of total shellfish consumption in Korea. The mean concentration of microplastics in these four species was 0.15 ± 0.20 n/g and 0.97 ± 0.74 n/individual. Fragments and particles smaller than 300 μm were dominant shape and size, accounting for 76% and 65% of total microplastics, respectively. Polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyester were the major polymer types. Interestingly, differing polymer compositions were observed according to the culture methods and habitat characteristics of each species. PS was found in high proportions in oysters and mussels cultured in the upper layer of the water column, while the proportions decreased and those of polyester increased in Manila clams and scallops that were cultured in intertidal sediments or the middle and bottom layers of the water column. The annual dietary intake of microplastics by the Korean population via shellfish consumption was estimated as 212 n/person·year. Our results suggested that microplastic pollution is widespread in commercial bivalves and we recommend a systematic and integrative market-basket survey to clarify the current status of human exposure to microplastics. [Display omitted] •Microplastic (MP) contamination in bivalves purchased from markets was studied.•MP contamination was widespread in market bivalves.•Shape and polymer type of MP were influenced by farming method of each species.•The dietary intake of MP by the Korean population via shellfish was estimated.•Seafood consumption can be a route of MP exposure for humans. Microplastic contamination in market bivalves from South Korea was investigated to understand human exposure to microplastics via seafood consumption.