Perfluoroalkyl acids in the water cycle from a freshwater river basin to coastal waters in eastern China.
The distribution of perfluoroalkyl acids (PFAAs), one class of persistent organic pollutants, in groundwater, especially in confined aquifers remains poorly understood. In this study, we investigated the occurrence of 12 PFAAs through a water cycle from the Huai River Basin to the Yellow Sea, including confined aquifers, unconfined aquifers, rivers, and coastal waters. We found the ubiquity of PFAAs in all types of samples, including those from confined aquifers (2.7-6.8 ng/L). Perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were the major PFAAs in all samples, accounting for an average of 49.1% (0.8-84.8%) and 33.3% (6.3-92.2%) of total PFAAs, respectively. Comparing the concentration of PFOA with that of PFOS, we found a higher concentration of PFOA in rivers and a higher concentration of PFOS in confined aquifers. Short-chain perfluoropentanoic acid accounted for an average of 10.3% (1.9-24.6%) of total PFAAs in rivers and coastal waters. Branched isomers of both PFOA and PFOS were detected in most samples (36/42 and 39/42, respectively). One-way analysis of variance indicated a significant difference in the profiles of PFAAs among the different types of water samples. Principal component analysis suggested that rainwater and recent uses of PFAAs could be the major sources of PFAAs in confined aquifers, while recent and current uses of PFAAs could be the major source of PFAAs in unconfined aquifers, rivers and coastal waters. The risk quotients of PFOA and PFOS in groundwater and rivers were 2-3 orders of magnitude lower than unity, indicating no immediate risks via drinking water consumption.
MOE Key Laboratory of Surficial Geochemistry, Department of Hydrosciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing, People's Republic of China.
Xiaobin
X
Zhu
Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
Ling
L
Jin
Laboratory of Immunology and Reproductive Biology, School of Medicine, Nanjing University, Nanjing, People's Republic of China.
Jingping
J
Yang
MOE Key Laboratory of Surficial Geochemistry, Department of Hydrosciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing, People's Republic of China.
Jianfeng
J
Wu
State Environmental Protection Key Laboratory of Monitoring and Analysis for Organic Pollutants in Surface Water, Jiangsu Provincial Environmental Monitoring Center, Nanjing, People's Republic of China.
Beibei
B
Zhang
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.
Xiaowei
X
Zhang
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China. Electronic address: yuny@nju.edu.cn.
Nanyang
N
Yu
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China. Electronic address: weisi@nju.edu.cn.
Si
S
Wei
MOE Key Laboratory of Surficial Geochemistry, Department of Hydrosciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing, People's Republic of China.
Jichun
J
Wu
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, People's Republic of China.
Hongxia
H
Yu
D017738:Alkanesulfonic Acids / Q000032:analysis*; D002210:Caprylates / Q000032:analysis; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D005466:Fluorocarbons / Q000032:analysis*; D005618:Fresh Water / Q000032:analysis; D005843:Geography; D060587:Groundwater / Q000032:analysis*; D018570:Risk Assessment; D045483:Rivers; D058438:Water Cycle; D014874:Water Pollutants, Chemical / Q000032:analysis*
D017738:Alkanesulfonic Acids; D002210:Caprylates; D005466:Fluorocarbons; D014874:Water Pollutants, Chemical; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid
Branched isomer; Confined aquifers; Health risk; Perfluorooctane sulfonate; Perfluorooctanoic acid; Unconfined aquifers