Risk assessments of microplastic exposure in bivalves living in the coral reefs of Vietnam

Abstract

This study aimed to assess the presence of microplastics in bottom sediment and bivalve species, including Pinna bicolor, Atrina vexillum, Saccostrea sp., and Pinctada margaritifera, living in coral reefs on Vietnam's Southern coastal. The average microplastic abundance were 0.45 ± 0.13 items/g of wet soft tissue weight or 5.60 ± 1.49 items/individual in bivalve samples and 294 ± 43 items/kg dry weight of sediment samples. The fragment shape, size smaller than 100 μm, and polyethylene, polyamide, cellophane and polyethylene terephthalate were identified as the predominant constituents of the microplastics. The pollution load and potential ecological risk index of microplastics were at a minor level, whereas the polymer hazard index was at a high level. Overall, this study provides a basis for assessing the risks posed by microplastics in the marine ecosystems of Vietnam.

Keywords: Bivalve; Coral reef; Ecological risk; Microplastic; Sediment.