title: Sequestration and bioavailability of perfluoroalkyl acids (PFAAs) in soils: Implications for their underestimated risk.
abstract: Different from typical hydrophobic organic contaminants (HOCs), perfluoroalkyl acids (PFAAs) are more soluble in water and less partitioned to soil than the HOCs. It remains unclear whether and to what extent PFAAs could be sequestrated in soil. In this study, sequential extraction of PFAAs in soil and bioaccumulation of PFAAs in earthworm were carried out to understand the sequestration and bioavailability of PFAAs in soils with different soil organic matter (SOM) and aged for different time periods (7 and 47d). Sequestration occurred in different degrees depending on the amount and compositions of SOM in soil, structural properties of PFAAs and aging time. Surprisingly, in one peat soil with high fraction of organic carbon (foc, 59%), the PFAAs were completely sequestrated in the soil. Aging might lead to further sequestration of PFAAs in soil with relatively lower foc. As a consequence of sequestration, the bioavailability of PFAAs in peat soils was reduced 3-10 times compared to that in the plain farmland soil. However, the sequestrated PFAAs were still bioaccumulative in earthworms to some extent. The results indicated that the risk of PFAAs in field soil with high content of SOM could be underestimated if only free PFAAs using mild solvent extraction were monitored.
authors: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China; Institute of Agro-Environmental Protection, Ministry of Agriculture, Tianjin 300191, China.
authors: Lixia
authors: L
authors: Zhao
authors: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. Electronic address: zhuly@nankai.edu.cn.
authors: Lingyan
authors: L
authors: Zhu
authors: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors: Shuyan
authors: S
authors: Zhao
authors: Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors: Xinxin
authors: X
authors: Ma
mesh_terms: D000818:Animals; D001682:Biological Availability; D002681:China; D004784:Environmental Monitoring / Q000379:methods*; D005466:Fluorocarbons / Q000378:metabolism*; D009835:Oligochaeta / Q000378:metabolism*; D010421:Pentanoic Acids / Q000378:metabolism*; D018570:Risk Assessment; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D005466:Fluorocarbons; D010421:Pentanoic Acids; D012989:Soil Pollutants; C000619812:perfluoropentanoic acid
keywords: Bioavailability; Earthworm; Perfluoroalkyl acids (PFAAs); Sequestration; Soil