Pollution characteristics and ecological risk of microplastic in sediments of Liaodong Bay from the northern Bohai Sea in China.

Microplastics (MPs) are widely distributed in marine environments. The pollution characteristics and risk assessment of MPs in estuarine sediments are still insufficient. In this study, the MPs pollution characteristics in surface sediments of the Liao Estuary and Daliao Estuary were investigated. The characteristics of MPs in sediments were determined by stereo microscopy and micro-Fourier transform infrared spectroscopy. The results showed that the average MPs abundance ranged from 32.33 to 49.91 items·kg d.w. The MPs were mainly composed of 500-2000 μm black and blue fibers. Five polymer types were identified, including rayon (RA) (87.46 %), polyethylene terephthalate (PET) (6.81 %), polyamide (PA) (2.94 %), polypropylene (PP) (2.17 %) and polyethylene (PE) (0.62 %). The pollution load index (PLI) risk assessment showed that all sampling sites were at Hazard Level I. Our results can provide useful information for assessing the environmental risks of MPs in coastal areas of China.