Risk Assessment of Microplastic Exposure in the Marine Sediment of Southern Central Waters of Vietnam

The presence of microplastics in marine sediments in the Southern central waters of Vietnam were conducted for the first time by this study. Research samples were collected at fourteen sampling sites at depths of 5–25 m. From the present finding, microplastics were presented in all collected samples with average concentrations ranging from 100 to 1350 MPs/kg. Fibers and fragments were the two main shapes of microplastics with a ratio of 55.12 and 44.88%, respectively. Microplastics ranged in size from 22.7–1501.6 µm, with the majority falling below 100 µm (31.50%). The Nicolet iN10 MX Infrared Imaging Microscope device identified nine polymer types of microplastics with 80% similarity to the standard spectrum library. Polyethylene Terephthalate (PET) and Polyamide (PA) were the two dominant polymers, accounting for 33.86 and 24.41%, respectively. The calculated Polymer hazard index showed that all sampling sites belonged to a hazard level from II to IV. Both the Pollution load index and Potential ecological risk index reached values of hazard level I. This indicated the potential risk posed by microplastics to the ecosystem. These research findings offer essential insights into the current status of microplastic pollution in Vietnam.