Sources and transformation pathways for dichlorodiphenyltrichloroethane (DDT) and metabolites in soils from Northwest Fujian, China
Sources and transformation pathways for dichlorodiphenyltrichloroethane (DDT) and metabolites in soils from Northwest Fujian, China
复制标题
中国闽西北土壤中二氯二苯基三氯乙烷（DDT）及其代谢物的来源和转化途径
DOI：
10.1016/j.envpol.2017.12.071
复制
发表时间：
2018-04-01
影响因子：
8.9
通讯作者：
Qi, Shihua
中科院分区：
文献类型：
--
作者：
Huang, Huanfang;Zhang, Yuan;Qi, Shihua
三氯杀螨醇（2，2，2-三氯-1，1-双-（对氯苯基）乙醇）是一种存在于环境中的杀螨剂，它不仅是一种商业用途的杀螨剂，而且是二氯二苯三氯乙烷（DDT）的一种代谢物，而DDT往往被人们所忽视。为探明土壤中DDT及其代谢物的来源和转化途径，测定了闽西北土壤中p，p'-（三氯杀螨醇+DBP）（p，p'-三氯杀螨醇和4，4'-二氯二苯甲酮的总和）、DDT及其6种代谢物的含量。1，1，1-三氯-2-（邻氯苯基）-2-（对氯苯基）乙烷（o，p'-DDT）/1，1，1-三氯-2，2-双-（对氯苯基）乙烷（p，p'-DDT）的比例和质量平衡表明，p，p'-（三氯杀螨醇+DBP）主要来自p，p'-DDT的转化，而不是三氯杀螨醇的实际应用。p，p '-（三氯杀螨醇+邻苯二甲酸二丁酯）占DDT主要代谢产物的45.0%，超过1，1-二氯-2，2-二对氯苯基乙烯（p，p'-DDE）和1，1-二氯-2，2-双-对氯苯基乙烷（p，p'-DDD），这可能会导致使用传统的（Sigma 2DDD + Sigma 2DDE）/Sigma 2DDT（包括所有o，p'-和p，p'-异构体）。在好氧（干旱期）和厌氧（湿润期）交替的稻田中，p，p'-DDD和p，p'-DDE都有可能降解为1-氯-2，2-二（对氯苯基）乙烯（p，p'-DDMU），后者进一步转化为2，2-二（对氯苯基）乙烯（p，p'-DDNU）。p，p'-DDMU降解为p，p'-DDNU主要发生在涝渍水稻土中。然而，p，p'-DDNU可能不会转化为其他高阶代谢产物在好氧表层土壤。本研究证实p，p'-（三氯杀螨醇+DBP）是p，p'-DDT的代谢产物，DDE和DDD是DDMU的平行前体，进一步验证了DDT在表层土壤中的转化途径。(C)2018爱思唯尔有限公司版权所有
Dicofol (2,2,2-trichloro-1,1-bis-(p-chlorophenyl)ethanol) found in the environment is not only a miticide originated from commercial use, but also a metabolite of dichlorodiphenyltrichloroethane (DDT), which is often overlooked. To verify the sources and transformation pathways of DDT and related metabolites in soils, we measured p,p'-(dicofol + DBP) (sum of p,p'-dicofol and 4,4'-dichlorobenzophenone), DDT and six metabolites in soils from Northwest Fujian, China. The ratios of 1,1,1-trichloro-2-(o-chloropheny1)-2-(p-chlorophenyl)ethane (o,p'-DDT)/1,1,1-trichloro-2,2-bis-(p-chlorophenyflethane (p,p'-DDT) and the mass balance demonstrated that p,p'-(dicofol + DBP) predominantly originated from p,p'-DDT transformation rather than from actual dicofol application. p,p'-(dicofol + DBP) accounted for 45.0% as the primary metabolites of DDT in this study, more than 1,1-dichloro-2,2-bis-(p-chlorophenyl)ethylene (p,p'-DDE) and 1,1-dichloro-2,2-bis-(p-chlorophenyl)ethane (p,p'-DDD), which might lead to large overestimations of the fresh DDT input by using the traditional ratio of (Sigma 2DDD + Sigma 2DDE)/Sigma 2DDT (with all o,p'- and p,p'-isomers included). In paddy fields where the conditions alternate between aerobic (dry period) and anaerobic (wet period), both p,p'-DDD and p,p'-DDE were likely to degrade to 1-chloro-2,2-bis-(p-chlorophenyl)ethylene (p,p'-DDMU), which further transformed to 2,2-bis(p-chlorophenyl) ethylene (p,p'-DDNU). Degradation of p,p'-DDMU to p,p'-DDNU mainly occurred in waterlogged paddy soils. However, p,p'-DDNU might not transform to other higher-order metabolites in aerobic surface soils. Overall, our study confirmed p,p'-(dicofol + DBP) as metabolites of p,p'-DDT, suggested DDE and DDD were parallel precursors of DDMU, and further verified the transformation pathways of DDT in surface soils. (C) 2018 Elsevier Ltd. All rights reserved.