Microplastics in <i>Saccostrea commercialis</i> oysters and surrounding water habitats in Rayong, Thailand: Pollution status and risk assessment

Microplastic contamination in aquatic ecosystems has emerged as a pressing environmental issue, sparking widespread concern about its potential effects on marine life, ecosystem, and human well-being. This study examined microplastic contamination in oysters ( Saccostrea commercialis ) and the surrounding coastal environment (water) within the brackish area of La Won Canal, Rayong Province, Thailand. Additionally, it evaluated potential health risks associated with the polymer components using the Polymer Hazard Index (PHI). The average concentration of microplastics was determined to be 4.39 ± 2.34 particles/g (wet weight) in oysters and 1.53 ± 0.27 particles/L in water. Fibers were identified as the predominant shape, with most particles measuring less than 250 μm in size. Both oysters and water samples contained four types of polymers: polypropylene (PP), polyethylene (PE), chlorinated polyethylene (CPE), and the copolymer poly(ethylene-co-acrylic acid) (PEAA), along with non-polymer cellophane. Among these, PP was the most abundant, constituting 40% of the microplastics found in oysters. The PHI analysis classified the polymer components of microplastics in oysters as belonging to hazard category IV. This indicates that microplastic contamination in bivalves could present a potential health risk to humans through the consumption of seafood.