Overall evaluation of microplastic exposure in oysters (Crassostrea gigas) in coastal areas of Viet Nam

Abstract

This study aimed to evaluate the presence of microplastics (MPs) in oysters (Crassostrea gigas) across the coastal area of Vietnam. Oyster samples were collected from sixteen coastal provinces across Vietnam, from North to South. Visual and chemical verification of microplastics were performed by the micro Fourier transform infrared (μFTIR) method using the Nicolet iN10 MX Infrared Imaging Microscope. The average concentration of MPs was 1.18 ± 0.59 MPs/g of wet weight or 11.55 ± 4.83 MPs/individual. Fragments were the dominant shape of MPs, followed by fibers and beads, corresponding to 62.40 %, 37.10 %, and 0.50 %, respectively. The detected MPs varied in size from 20 to 998 µm with an average size of 112 ± 125 µm. The majority of MPs size was smaller than 100 µm, accounting for 65.39 %. A total of twelve polymers were detected, of which Polyethylene terephthalate (PET) and high-density polyethylene (HDPE) were the two dominant types, accounting for 42.26 % and 31.95 %, respectively. This study provides valuable insights into the presence and potential risks posed by MPs from the oyster (C.gigas) in coastal areas of Vietnam.