| Abstract | Microplastic contamination in marine ecosystems has been a major problem nowadays. Microplastics can be accidentally ingested by marine species and eventually enter into food chain. Filter-feeders; Oysters (Crassostrea spp.), cockles (Anadara spp.) and green mussels (Perna viridis) were used in this study as marine microplastic contaminant indicators. This study identified physical and chemical characteristics of microplastics that found in shellfish. They were cultivated in Surat Thani province, south of Thailand. Analysis section in this study also estimated microplastic intake per day and human exposure during their lifetime. People's behaviors usually consume the whole body of oysters, cooked cockles and green mussels. As a result, they may accidentally consume microplastics through shellfish products consumption. Average matter weight of oysters, cockles and green mussels were 19.57±2.89, followed by 3.23±0.56 and 7.74±1.74 g per individual. This study applied microplastic identification methodology from Mathahon and Hill, 2014. Average microplastics contaminated in them were 6.0±3.0, 3.33±1.53 and 4.67±2.08 pieces/g (wet weight), respectively. Physical identification of microplastics found only fiber type with blue, transparent and black color. For chemical properties by FT-IR, there were polyester, polyethylene, linen and cellophane. There are two sections in human exposure assessment. The microplastic intake per day estimation applied from Theerawittayalert & Ngamkham, 2017, lifetime average dose or intake from health risk assessment from MOPH, 2018 and bioavailability in gut, tissue and feces in worst case from Mohamed et al., 2021. Microplastic intake per day through shellfish consumption based on Thai population’s shellfish consumption. For the general eater, they may intake microplastics from oysters, cockles and green mussels around 0-0.66, 0.14-2.31 and 0.22-2.05 pieces/day. For the eater only, they intake microplastics from shellfish around 6.60-43.40, 4.0-16.18 and 4.36-14.33 pieces/day, respectively. The most exposure to microplastic intake could be age groups 3-6 and 6-13 years old. Secondly, they may receive microplastics at least 2,664.78 and reach up to 399,894 pieces/kg-bw during human lifetime depending on their bioavailability. |