Microplastic in cultured oysters from different coastal areas of China

Microplastics are an emerging concern in the marine environment due to their small size; they can be ingested by aquatic organisms, especially filter-feeding organisms, such as oysters. The presence of microplastics in seafood may pose a threat to food safety, and there is an urgent need to evaluate the potential risks of microplastics to human health. This study quantified the microplastics in oysters from 17 sites along the coastline of China. Qualitative attributes, such as shape and size, were also determined under a microscope. Additionally, the polymer types were identified using Fourier-Transform Infrared Micro-Spectroscopy (μ-FT-IR). The results showed that the average abundance of microplastics in oyster was 0.62 items/g (wet weight) or 2.93 items/individual. Additionally, 84% of the sampled oysters had inhaled microplastics, indicating the high prevalence of microplastic pollution in different coastal areas of China. Fibers were the most common shape (60.67%), and the most common size was <1500 μm, accounting for 81.89% of the total microplastics. The μ-FT-IR analysis identified eight different polymers, and the main polymeric types of microplastics were cellophane (CP), polyethylene (PE) and polyethylene terephthalate (PET). Our results suggest the widespread prevalence of microplastics in cultured oysters from different coastal areas of China with similar or lower abundances than other countries. In addition, our results exhibited regional characteristics of high microplastics abundance in southern coastal area of China and low microplastics abundance in northern China. Further investigations are warranted to examine microplastics contamination in other seafood species from different geographical sites in coastal area of China.