Discharge of perfluorinated compounds from rivers and their influence on the coastal seas of Hyogo prefecture, Japan

- High perfluorohexanoic acid concentration was detected in the Samondogawa River.
- The mass flow rate of PFCs in this river section was 3900-29,000 kg/y.
- Perfluorohexanoic acid was the dominant compound at all seawater sampling sites.
- Perfluorohexanoic acid from the Samondogawa River may have affected Osaka Bay.

The aim of this study was to investigate 12 perfluorinated compounds (PFCs) including perfluorinated carboxylates (C4-C12) and perfluorinated alkyl sulfonates (C4, C6, and C8) in river and seawater samples to determine contamination levels in the aquatic environment of Hyogo prefecture, Japan. High levels of perfluorohexanoic acid (PFHxA; 2300-16,000 ng/L) were detected in the Samondogawa River at Tatsumi Bridge downstream of a PFC production facility; this location also had the highest mass flow rate of PFCs (3900-29,000 kg/y). Widespread contamination of coastal waters was confirmed with PFHxA as the dominant compound. Perfluorooctanoic acid was also prevalent in coastal waters. The concentration of PFHxA in coastal seawater and the distance from the mouth of the Samondogawa River were inversely related. This discharge of high concentrations of PFHxA from the Samondogawa River may have affected concentrations of PFCs in Osaka Bay.