Perfluoroalkyl acids (PFAAs) in water along the entire coastal line of China: Spatial distribution, mass loadings, and worldwide comparisons

Perfluoroalkyl acids (PFAAs) have been ubiquitously distributed in water environment worldwide for a long time, especially in the estuaries and coastal areas. In this study, the distribution characteristics of 12 PFAAs in 91 main river estuaries along the entire coast of China were analyzed for the first time, and the riverine PFAAs fluxes into the coastal marine environment were estimated. Based on a mini-review, the PFAAs pollution in the coast of China at a global scale was evaluated, which was intended to reveal the overall level of PFAAs and to provide a science basis for strengthening environmental management along the coast of China. The results showed that perfluorooctanoic acid (PFOA), perfluorobutanoic acid (PFBA), and perfluorobutane sulfonic acid (PFBS) were dominant in the whole coastal region, which indicated the usage of PFAAs was changing from long-chain PFAAs to short-chain substitutes in China. With regard to the spatial distribution, the high PFAAs concentrations were found in the coastal areas of south Bohai Sea, Shandong Province from the north while those in the south were generally lower when taking the Qinling Mountain and Huaihe River as a dividing line. The estimated PFAAs riverine mass loading in the whole coastal region was 131 tons per year, and the discharge flux of the Yangtze River accounted for more than half (73.5 tons). In comparison with global data, PFAAs concentrations in the coast of China was at a moderate level, and the detected hotspots of high levels were strongly influenced by fluorochemical industries. However, the mass loading of PFAAs was diversified due to geographical differences and abundant river discharges.