Multi-media distribution and risk assessment of per- and polyfluoroalkyl substances in the Huai River Basin, China.

The widespread existence, environmental persistence, and risks of per- and polyfluoroalkyl substances (PFASs) have attracted widespread attention. Herein, the distribution and risk assessment of PFASs were investigated from the Huai River Basin. The ranges in different media were 29.83-217.96 (average of 75.82 ± 35.64 ng/L) in water, 0.17-9.55 ng/g (2.56 ± 2.83 ng/g) in sediments, and 0.21-9.76 ng/g (3.43 ± 3.07 ng/g) in biota. Perfluoropentanoic acid (PFPeA) was the most prevalent PFAS in surface water, followed by perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA), accounted for 42.62 %, 22.23 % and 17.72 % of the total concentrations of the PFASs analyzed, respectively. PFBA was dominant in sediments, accounting for 60.37 % of the total concentrations of the PFASs analyzed. Perfluorooctane sulfonate (PFOS) was the main pollutant in biota, and the highest concentration (5.09 ng/g) was found in Channa argus. Considering the measured concentrations in water, sediments and biota, the sediment-water partition coefficients (log Kd) and bioaccumulation factors (BAF) of PFASs were determined. The log Kd of the PFASs differed among those with a different carbon chain length, C7-C11 PFASs were more likely to be adsorbed onto sediments as the carbon chain length increases, and PFUnDA and PFDA showed the higher BAF value in Channa argus. PFASs in the Huai River Basin posed an acceptable ecological risk, and long-chain PFAS contamination provided green algae with a higher potential ecological risk. Compared to drinking water, aquatic products constituted a higher PFASs threat to human health, especially for children. The highest HQ was found in PFOS, with an HQmax of 0.97-4.32. Residents in the Huai River Basin should reduce their intake of Channa argus, Coilia nasus, and Carassius auratus, children aged 2 to 4 are limited to consuming no more than 6.9 g/d, 9.7 g/d, and 16.6 g/d, respectively.

Perfluoroalkyl substances in the surface water and fishes in Chaohu Lake, China.

The concentration and composition of 13 perfluoroalkyl substances (PFASs) in surface water and fishes in Chaohu Lake, China, were systematically studied in October 2019. Results showed that the PFASs composition has changed greatly. The concentration levels of perfluorooctane sulfonate (PFOS) in the surface water of Chaohu Lake have decreased significantly compared with past years. Perfluorobutanoic acid (PFBA) has become the dominant component, and it was mainly come from industrial wastewater. The highest concentration of perfluorooctanoic acid (PFOA) was measured in the lake inlet of the Baishitian River (southwest part), which mainly received domestic sewage. Different types of wastewater lead to varying compositions of PFASs in the lake water. PFOA and PFBS were homologous in some areas of Chaohu Lake, which reflected the unbalanced promotion of prohibition and substitution of long-chain PFASs around Chaohu Lake. On the basis of the risk quotient and tolerable daily intake assessment, drinking water and eating fish from Chaohu Lake do not lead to apparent PFAS risk, but PFOS in fish has evident bioaccumulation and biomagnification effects. PFOS-based human daily intake of Channa argus accounts for 22.4% of the tolerable daily intake. Thus, the risk caused by PFOS needs close attention. This study is useful for enhancing people's understanding of the environmental behavior and the risk of PFASs in Chaohu Lake.