DDT引发的争论及启示

本文沿着DDT从1874年合成到将在2020年淘汰的轨迹和趋势,第一次依据历史重大事件并结合SCI文献数量将DDT的发展分为4个历史阶段,着重探讨了这种“万能杀虫剂”带来的3个争论:DDT对人类的健康影响、禁用还是使用DDT、以及如何评价DDT.本文从DDT由人类的“宠儿”变成“弃儿”的历史演变中分析得出了一些启示,并...     

食品中六六六和滴滴涕残留检测方法研究进展

六六六和滴滴涕作为一种高效的杀虫剂曾经在全球被广泛使用,与20世纪80年代在我国被禁用,但是在环境和食品中仍有残留,其前处理方法和检测方法已引起关注和重视。简述六六六和滴滴涕对动物体的危害,并综述国内外食品中六六六、滴滴涕前处理方法和检测方法的研究进展。     

Current- and past-use pesticide prevalence in drainage ditches in the Lower Mississippi Alluvial Valley

BACKGROUND: Pesticide application is common in agriculture and often results in applied pesticides entering adjacent aquatic systems. This study seasonally analyzed a suite of 17 current‐ and past‐use pesticides in both drainage waters and sediments to evaluate the prevalence of pesticides in drainage ditches across the Lower Mississippi Alluvial Valley (LMAV). RESULTS: There were significantly higher concentrations (P < 0.05) of current‐use than past‐use pesticides; however, there were consistently high numbers of detections of past‐use pesticides in sediments. Sediment pesticide concentrations were an order of magnitude higher (150–1035 µg kg^?1) than water samples (6–20.9 µg L^?1). Overall, 87% of all samples analyzed for current‐ and past‐use pesticides were non‐detects. p,p′‐DDT was detected in 47.5% of all drainage waters and sediments sampled. There were significant correlations (0.372 ≥ r²≤0.935) between detected current‐use water and sediment concentrations, but no significant correlations between past‐use water and sediment concentrations. CONCLUSION: Overall, there was a high percentage (87%) of sediment and water samples that did not contain detectable concentrations above the lower limit of analytical detection for each respective pesticide. This lack of pesticide prevalence highlights the improved conditions in aquatic systems adjacent to agriculture and a potential decrease in toxicity associated with pesticides in agricultural landscapes in the LMAV. Copyright © 2011 Society of Chemical Industry     

The concentration of pesticides in sediments from Kolleru Lake in India

Kolleru Lake is the largest natural freshwater lake in India. Sediment samples were collected at different locations from Kolleru Lake at different seasons in a year over a period of three years and analyzed for eight selected pesticides. In general, pesticides were present at all locations. The selected pesticides alpha-BHC, gamma-BHC, malathion, chlorpyrifos and endosulfan were present at higher concentrations than isodrin, dieldrin and p,p'-DDT. The concentrations of alpha-BHC, gamma-BHC malathion, chlorpyrifos, isodrin, endosulfan, dieldrin and p,p'-DDT in sediments were 1.2-388, 1.4-212, from below the minimum detection limit (BDL)-186, 1.1-292, BDL-38.6, BDL-206, BDL-128 and BDL-191 micrograms kg-1 dry weight, respectively. The aim of this study is to evaluate baseline data, to try to account for the concentration of pesticides in sediments and to discuss their potential to affect human beings and aquatic organisms.     

河北省土壤中滴滴涕的残留量分析

采用快速溶剂萃取仪和气相色谱仪研究了河北省土壤中有机氯农药滴滴涕的残留状况.结果表明,河北省土壤中滴滴涕的残留量均值为51.52 ng/g,经对比相关标准,河北省土壤中的滴滴涕残留量处于较低的污染水平.     

河南省农药污染现状评价

1988-1989年对河南的农药残留污染现状进行了评价研究。结果表明：DDT的综合污染指数为0.055，其在河南的污染已经消除；六六六的综合污染指数为0.154,在肉、蛋、奶、植物油中的残留污染仍较严重，其检出率为100%，超标率12.5%-50%，残留量tra-5.271ppm，污染综合指数0.473-0.491，对其它环境因素污染较轻。有机磷和呋喃丹杀虫剂的残留污染日趋严重；残留比较突出的是蔬菜和瓜果，检出率9%-50%，超标率0-45%，残留量0-38ppm；大米和小麦残留较轻，检出率10.7%-10.8%,超标率7.14%-8.1%,残留量0-11ppm。     

表面活性剂对南瓜消解土壤中DDT的影响

采用盆栽试验方法,研究了两种常用表面活性剂SDBS和Tween60对土壤中的DDT植物修复作用的影响。结果表明,表面活性剂SDBS可明显加速土壤中DDT的消解,为空白对照的3倍,而且SDBS可以促进南瓜对DDT的富集。在临界束胶浓度时,表面活性剂SDBS的作用效果优于Tween60。DDT在植物体中浓度分布最高为根部,南瓜可很好地去除土壤中的DDT。     

稻改草后土壤中DDT及其代谢产物的动态变化

用盆栽方法研究了DDT及其主要降解产物在水稻土改种草后土壤中的残留动态，比较了植黑麦草土壤与未植草土壤中DDT残留的差异。盆栽试验设计3种DDT处理浓度，分别为0、0．5、5．0mg kg^-1，每处理4次重复。研究表明，DDT的残留量随着时间的增加而不断减少，且前期降解速率比后期快。在试验的第81天，DDT浓度为0．5、5．0mg kg^-1的植草土壤中，DDT分别减少了27．24％、20．50％。比较植黑麦草和未植黑麦草土壤，p，p′-DDT残留量在试验的16d、32d、64d、81d均出现显著性差异。这可能与植物释放到根际的酶和有机分泌物能有效地促进农药降解有关。同时，DDT的代谢产物DDE随着时间的增加而逐渐增加。     

中国乌鲁木齐土壤中有机氯的来源、组成与风险评价

Twenty-eight surface soil samples from 5 functional zones (park, traffic roadside, business/residential area, rural area, and industrial area) of Ürümqi, China were collected and analyzed for the concentrations of 14 organochlorine pesticides (OCPs), such as 3 isomers of hexachlorocyclohexane (HCHs) (α-HCH, β-HCH, and γ-HCH), 4 dichlorodiphenyltrichloroethanes (DDTs) (p, p’-DDT and its metabolites p, p’-DDD (1,1-dichloro-2,2-bis(p-chlorophenyl)ethane) and p, p’-DDE (1,1-dichloro-2,2-bis(4-chorophenyl)ethylene), and o, p’-DDT), and methoxychlor, aiming to survey the residue levels and compositions of these 14 OCPs, to identify possible sources of the OCPs, and to assess their potential risks to human health and the environment in surface soils of Ürümqi. The concentrations ranged from non-detected to 30.86 μg kg^-1 for HCHs (sum of α-, β-, and γ-HCH), from non-detected to 40.03 μg kg^-1 for DDTs (sum of p, p’-DDT, p, p’-DDD, p, p’-DDE, and o, p’-DDT), and from non-detected to 11.95 μg kg^-1 for methoxychlor. The total concentrations of the OCPs ranged from 16.40 to 84.86 μg kg^-1, with a mean of 41.89 ± 16.25 μg kg^-1. According to the measured concentrations and occurrence rates of the 14 OCPs, DDTs, HCHs, and methoxychlor were the most dominant compounds. Among the 5 functional zones, the total concentration of OCPs was in the order of rural area > traffic roadside > park > business/residential area > industrial area. The different compositions of DDTs and HCHs indicated that the residues of these compounds in most soil samples originated from historical application, besides slight recent introduction at some sampling sites. The results of Pearson correlation analysis showed that soil total organic carbon played an important role in the residue levels of HCHs, but such relationships were not found with DDTs or other OCPs. The soil quality of Ürümqi was classified as Class I based on the guidelines of the Chinese Environmental Quality Standard for Soil (GB15618-1995), indicating that the residue levels of OCPs have little risks to the environment and human health in the study area.     

典型滴滴涕废弃生产场地污染土壤的人体健康风险评估研究

对我国典型滴滴涕(DDT)废弃生产场地的疑似重污染区进行环境调查、污染土壤人体健康风险评估和土壤修复建议目标值计算。结果表明,该场地污水处理池周边的关注污染物主要为p,p’-DDT、p,p’-DDD、p,p’-DDE、1,4-二氯苯、氯仿和氯苯,临近污水处理池北侧和东侧的区域土壤中污染物垂向迁移明显,其他区域土壤污染物主要分布于0～50 cm土层。前5种关注污染物的致癌风险均超过10-6,部分点位p,p’-DDT和氯苯的非致癌危害指数大于1。不确定性分析表明,半挥发性有机物p,p’-DDT、p,p’-DDD和p,p’-DDE经口腔摄入土壤和皮肤接触土壤暴露途径对总风险的贡献率超过98%,挥发性有机物氯苯、1,4-二氯苯和氯仿经吸入室内空气暴露途径对总风险的贡献率高达99%以上。土壤颗粒密度、土壤容重和土壤含水率是敏感参数。p,p’-DDT、p,p’-DDD、p,p’-DDE、氯苯、1,4-二氯苯和氯仿的土壤修复建议目标值分别为5.84、6.19、4.36、36.2、0.55和0.02 mg kg-1。