Current status of microplastics pollution in tianjin coastal waters

Abstract

Microplastics (MPs) have home a global concern as well as climate change, ozone separation and ocean discrimination. In order to restore the distribution characteristics and influence factors of MPs in Tianjin coastal waters, the distribution of MPs in three sections of Tianjin office area was studied by using surface sampling, density usage separation and alternative microscopies. The size, shape and chemical composition of MPs were further analyzed. Our results show that the extent of MPs in the sea water samples were rang from 210 to 1170 particles . m−3 with a mean of 612 particles . m−3 in the three sections of the offshore area. Three shape types of MPs were present in the seawater samples, including slender fibers, irregular fragments and thin films. Fibers and fragments were predominant forms, which accounted for 52.1% and 46.8%, respectively. The particle size of the detected MPs was consistent with those reported by previous studies. The smaller the particle size, higher the content 55.3% MPs had particle size of less than 0.5mm. According to the microscopy analysis result, most of MPs in surface seawater samples showed a deep color (such as blue, black and red), and a few MPs showed colors of yellow, green and while. The main chemical components of MPs were analyzed by using infrared microscopy components were detected, including PP-PE, ABS, CE, EP, PA, PE, PET, PP, and PVC, with an order of PET >PP-PE >EP >CE >ABS >PE >PA >PVC >PP. The results demonstrated that the MPs pollution in the Tianjin offshore area was affected by the development of marine industries, such as marine fishery, port transportation, etc. In addition, the MPs pollution in the ocean was also affected by land-based sewage discharge due to the fact that Tianjin was an industrialized city with a large population density.