Comparative Assessment of Microplastics in Surface Water and Sediments of Meishe River, Haikou, China

Meishe River is the longest urban river in Haikou. The level of microplastics pollution in this river may affect the ecological balance, and can have an adverse effect on human health. Thus, it is essential to gain a comprehensive understanding of the microplastics pollution in the river to ensure safety of the human living environment. Microscopic examination and Micro-Fourier Transform Infrared Spectroscopy (mu-FTIR) were used to investigate the distribution and characteristics of microplastic pollution in surface water and sediments of the Meishe River. The results revealed that microplastics extracted from Meishe River mainly consisted of polyethylene (PE) and poly octadecyl acrylate (POA), and the abundance of microplastics in the surface water and sediments lay in the range of 3-10 items/L and 61-205 items/100 g dry weight, respectively. With respect to shapes and colors of microplastics, among the micro plastics found in the surface water, 74% were fiber and 57% were white colored, while among those in the sediments, 88% were fiber and 55% were of white colored. In terms of particle size, microplastics with the particle size of 0.1-0.5 mm were the most abundant (49% approximately) in surface water, while the microplastics with particle size 1.0-5.0 mm were dominant (74%) in the sediments. The results clearly showed that the Meishe River was polluted by microplastics, which may eventually flow into the nearby sea and adversely affect the sea environment. Consequently, some organisms in the urban river may be adversely affected.