Investigation of perfluorinated compounds (PFCs) in mollusks from coastal waters in the Bohai Sea of China

The occurrence of perfluorinated compounds (PFCs) in the Bohai Sea region, a semi-enclosed bay in north China, was assessed in this present study. Nine different PFCs were measured in eleven mollusk species (soft tissues) collected from 9 coastal cities. Most of the analyzed PFCs could be detected in the samples, with perfluorooctanoic acid (PFOA) as the prominent PFC, although perfluorooctane sulfonate (PFOS) has been shown to be more bioaccumulative than PFOA by other studies. The detection frequency of PFOA was 72%. Significantly high levels of PFOA were found in Mactra veneriformis, Scapharca subcrenata and Meretrix meretrix Linnaeus, with mean concentrations at 31.3 ng g(-1), 15.0 ng g(-1) and 12.2 ng g(-1), respectively (dry weight). The distinct distribution of PFOA in these species can be used as a potential indicator of the bioaccumulation capacity. PFOS was found in mollusks at lower concentrations and frequency (61%). Positive linear regressions were found between perfluoroheptanoic acid (PFHpA), PFOA and PFOS (p < 0.01, n = 123), suggesting that these compounds may come from a similar origin of exposure and accumulation. It is suspected that higher emissions from usage or production of PFC related products might exist in Shouguang City, since the majority of the elevated concentrations of PFOA or PFOS were found in Shouguang. As the PFC concentrations in mollusks were comparatively low, humans are not likely to be at risk of PFC exposure through the daily consumption of these seafoods.