Spatial distribution of perfluoroalkyl substances in surface sediments of five major rivers in China.

Perfluoroalkyl substances (PFASs) have received great attention from the public and scientific community due to their potential adverse impacts on the ecosystem and human health. We investigated the occurrence and distribution of 16 PFASs from 2 classes of PFASs-perfluoroalkyl carboxylic acids and perfluoroalkane sulfonic acids-in the archived surface sediments of five major rivers (Yellow River, Hai River, Liao River, Zhujiang River, and Dongjiang River) in northern and southern China. The study was also performed during the wet and dry seasons. Perfluorooctanoic acid and perfluorooctane sulfonic acid were the most frequently detected (detection frequency = 100 and 63 %, respectively) in the sediments of the five rivers; the concentrations ranged from 0.08 to 0.99 ng/g dry weight (dw) and were lower than the limit of detection (<LOD), which is 3.89 ng/g dw for both. Perfluorodecanoic acid and perfluoroundecanoic acid were moderately detected (detection frequency = 42 and 44 %, respectively) with concentrations ranging from less than their limit of detection (<LOD) to 0.69 ng/g dw and <LOD to 0.22 ng/g dw, whereas 12 other target analytes were lower than their limit of quantification at most of the sampling sites. Greater concentrations of the PFASs were found at those sites located in urban areas compared with rural areas. Sediment organic content was found to be an important factor influencing the distribution of PFASs in the riverine environment. The results provided first-hand national data of PFASs in the sediments of major rivers in China.