Perfluoroalkyl substances in soils around the Nepali Koshi River: levels, distribution, and mass balance.
Perfluoroalkyl substances (PFASs) were analyzed in surface soils along the Koshi River in Nepal, a typical agricultural country with little industrialization and urbanization. Sixteen target PFASs were quantified in soils from a hilly region in central and eastern Nepal, but only ten PFASs were detected. Concentrations of total PFASs ranged from nd (below the detection limit) to 1.78 ng/g dw. The predominant PFASs in soils were perfluoro-octanoic acid (PFOA) and perfluoro-butanesulfonate (PFBS) with concentrations that ranged from nd to 0.26 ng/g dw and nd to 0.38 ng/g dw, respectively. Results of mass balance analysis also revealed weak associations among concentrations of PFASs, extractable organic fluorine (EOF), and total fluorine (TF). PFASs were relatively evenly distributed among locations. Due to the absence of direct emission of PFASs and slow development of local industry, PFASs in soils originated mostly from long-range atmospheric transport, consumer use, and disposal of PFASs-containing products. Uncontrolled disposal of domestic waste will be a challenge to controlling concentrations of PFASs in Nepal.
State Key Lab of Urban and Regional Ecology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
Bing
B
Tan
Tieyu
T
Wang
Pei
P
Wang
Wei
W
Luo
Yonglong
Y
Lu
Kumar Y
KY
Romesh
John P
JP
Giesy
D004784:Environmental Monitoring; D005466:Fluorocarbons / Q000737:chemistry*; D009390:Nepal; D045483:Rivers / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry
D005466:Fluorocarbons; D012989:Soil Pollutants; D014874:Water Pollutants, Chemical