Spatial Distribution of Perfluorinated Organic Compounds in Surface Marine Sediments from the Seto Inland Sea, Japan

Perfluoroalkyl substances (PFASs) such as perfluorocarboxylic acid (PFCAs) and perfluoroalkane sul fonates (PFSAs) are persistent, bioaccumulative, and toxic substances that are distributed worldwide. Here we investigated the current concentrations of PFASs in the surface sediments from the Seto Inland Sea, Japan. The concentrations of PFCAs in surface sediments from the Sea ranged from 0.05 to 0.67 ng g −1 . Perfluoroundecanoic acid (PFUnDA) was detected at all 15 sampling stations; its concentration was 0.05–0.24 ng g −1 . Perfluorohexanoic acid (PFHxA), which is used as an alternative to perfluorooctanoic acid (PFOA), was detected in Osaka Bay and Kii Channel. The contamination of PFCAs in the sediment from Osaka Bay and Kii Channel is shifting to PFHxA. In contrast, only perfluorooctanesulfonic acid (PFOS) was detected at the center part of the bays in the Sea. The sig nificant positive correlation between the PFCAs concentrations in the sediment and the sedimentation rates was observed in the Sea. Hence, the concentration of PFCAs in surface sediments from the Sea was controlled by the sedimentation rate.