| In this study, we analyzed the exposure characteristics of five perfluorinated compounds (PFCs: PFOA, PFNA, PFDA, PFDoA and PFOS) in the surface waters of China by collecting exposure data and reviewing chronic toxicity data for the five PFCs. The safety threshold method (MOS10) of the probabilistic ecological risk assessment method was then employed to evaluate the ecological risk of each PFC as well as their combined ecological risk. Our aim was to assess the potential ecological risk of PFCs in surface waters in China and provide a scientific basis for assessing and managing the risk of PFCs. Concentrations of the five PFCs in surface waters of 30 regions in China were obtained, and the respective concentration ranges for PFOA, PFNA, PFDA, PFDoA and PFOS were ND-772 ng/L, ND-73.6 ng/L, ND-94.9 ng/L, ND-33.3 ng/L and ND-286 ng/L. Among the five PFCs, the concentration range of PFOA was widest, and concentrations at the percentiles of 50, 75 and 95 were, respectively, 6.99, 26.01 and 188.80 ng/L, much higher than those for PFOS (1.33, 4.98 and 24.27 ng/L). Ecological risk assessment gave MOS10 values for all five PFCs of less than 1, and the probabilities of exposure concentrations of PFOA, PFNA, PFDA, PFDoA or PFOS exceeding 5th percentile chronic toxicity levels for aquatic organisms were, respectively, 0, 3.31%, 0, 1.00% and 0. From this it can be concluded that the ecological risk to aquatic organisms from the five individual PFCs is negligible. Further, the combined ecological risk of the five PFCs was evaluated, based on the total equivalent concentration, and the MOS10 value of the combined PFCs was also less than 1. The probability of the total equivalent concentration exceeding the 5th percentile toxicity value for aquatic organisms is 5.42%, suggesting an acceptable ecological risk level for exposure to PFCs in Chinese surface water. |
