Spatial and vertical variations of perfluoroalkyl acids (PFAAs) in the Bohai and Yellow Seas: Bridging the gap between riverine sources and marine sinks.

Perfluoroalkyl acids (PFAAs) are being increasingly reported as emerging contaminants in riverine and marine settings. This study investigated the contamination level and spatial distribution of 17 PFAAs within the depth profile of the Bohai and Yellow Seas using newly detected sampling data from 49 sites (June 29 to July 14, 2016). Moreover, the riverine flux of 11 selected PFAAs in 33 rivers draining into the Bohai and Yellow Seas was estimated from previous studies (2002-2014) in order to establish the relationship between riverine sources and marine sinks. The results showed that the Bohai and Yellow Seas were commonly contaminated with PFAAs: total concentrations of PFAAs in the surface, middle, and bottom zones ranged from 4.55 to 556 ng L-1, 4.61-575 ng L-1, and 4.94-572 ng L-1, respectively. The predominant compounds were PFOA (0.55-449 ng L-1), PFBA (More