Occurrence and distribution of perfluoroalkyl substances (PFASs) in sediments of the Dalian Bay, China

Highlights: • The sediment of the Dalian Bay was moderately contaminated by PFASs. • The predominant PFASs were PFOA, PFBS and PFBA. • The spatial distribution and vertical variation of PFASs in the sediments were analyzed. - Abstract: In the present study, the spatial distributions and vertical variations of PFASs in the sediments of the Dalian Bay were investigated. The total concentrations of PFASs (∑ PFASs) in surface sediments of Dalian Bay ranged from 1.49 to 2.66 ng g^{− 1} dw. The predominant PFASs in surface sediments were PFOA, PFBS and PFBA with the concentration ranges of 0.50 to 0.95, 0.21 to 0.94, and 0.035 to 0.32 ng g^{− 1} dw, respectively. For the two sediment cores, ∑ PFASs ranged from 1.20 to 2.00 and from 1.37 to 2.06 ng g^{− 1} dw, respectively. There was a maximum ∑ PFASs concentration value near the surface. In general, ∑ PFASs gradually decreased with increasing sampling depth after reaching the maximum. PFOA, PFBS and PFBA were also the predominant PFASs in the two sediment cores. It is recommended that the monitoring and risk assessment of short-chain PFAS should be taken into consideration, and further researches are needed to understand the transportation and fate of these chemicals in the aquatic environment.