title: Enantiomer signature and carbon isotope evidence for the migration and transformation of DDTs in arable soils across China.
abstract: Due to the adverse impact of DDTs on ecosystems and humans, a full fate assessment deems a comprehensive study on their occurrence in soils over a large region. Through a sampling campaign across China, we measured the concentrations, enantiomeric fractions (EFs), compound-specific carbon isotope composition of DDT and its metabolites, and the microbial community in related arable soils. The geographically total DDT concentrations are higher in eastern than western China. The EFs and δ13C of o,p'-DDT in soils from western China show smaller deviations from those of racemic/standard compound, indicating the DDT residues there mainly result from atmospheric transport. However, the sources of DDT in eastern China are mainly from historic application of technical DDTs and dicofol. The inverse dependence of o,p'-DDT and p,p'-DDE on temperature evidences the transformation of parent DDT to its metabolites. Initial usage, abiotic parameters and microbial communities are found to be the main factors influencing the migration and transformation of DDT isomers and their metabolites in soils. In addition, a prediction equation of DDT concentrations in soils based on stepwise multiple regression analysis is developed. Results from this study offer insights into the migration and transformation pathways of DDTs in Chinese arable soils, which will allow data-based risk assessment on their use.
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Lili
authors.initials: L
authors.lastname: Niu
authors.affiliation: College of Environment, Zhejiang University of Technology, Hangzhou 310032, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Xu
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Siyu
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Department of Geology &Geophysics, Louisiana State University, Baton Rouge, LA, 70803-4101, USA.
authors.forename: Huiming
authors.initials: H
authors.lastname: Bao
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Hongyi
authors.initials: H
authors.lastname: Li
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Xichang
authors.initials: X
authors.lastname: Zhang
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.|College of Environment, Zhejiang University of Technology, Hangzhou 310032, China.
authors.forename: Jiguo
authors.initials: J
authors.lastname: Qiu
authors.affiliation: International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Liu