Biochemical and histological alterations induced by a formulation of dicofol in the embryonic liver of Gallus domesticus

In the present investigation, hepatotoxic effect of a commercially available insecticide formulation of dicofol (Colonel–S® 18.5% emulsified concentrate) was studied in the developing chick embryo. Fertilized eggs of Gallus domesticus were immersed in three different dose concentrations, i.e. 250, 500, and 1000 mg L^?1 of Colonel–S on “0” and fourth days of incubation for 60 min at 37 °C and incubated till embryonic day 16. Severe histopathological cellular lesions, such as extensive cell degeneration and necrosis with enlarged blood sinusoids, cytoplasmic vacuolization, and leucocyte infiltrations with congestion or dilation of central vein, appeared in dose-depended manner. Dicofol treatment also caused significant decrease in the levels of total protein, glycogen, and glutathione content and an increase in alkaline phosphatase activity of embryonic liver, whereas glutamic pyruvic transaminase activity showed mixed response.     

农户参与三氯杀螨醇替代技术培训积极性的影响因素分析

病虫害综合防治（1PM）技术旨在结合生物、农学及物理防治方法,合理使用化学农药,降低农业生产成本,保护农业劳动者健康和生态环境.以联合国开发计划署（UNDP）、环境保护部对外合作中心和全国农业技术推广中心联合启动实施的“中国含滴滴涕三氯杀螨醇生产控制及IPM技术替代全额示范项目”为例,系统分析影响农户参与IPM培训积极性的主要因素.结果表明,农户种植规模对农户参与IPM培训的积极性影响显著,学员性别和年龄不是影响其参加培训积极性的显著因素;学员参加培训的次数越多,其对IPM技术的采纳率越高.农民田间学校应更多地吸收老人和妇女参加三氯杀螨醇替代技术及IPM培训     

南海北部沿岸海域近江牡蛎体中的三氯杀螨醇

在南海北部沿岸23个观测站,于2008～2010每年春季分别采集成体近江牡蛎(Crassostrea rivularis),取其软组织进行均质,有机溶剂超声萃取,浓硫酸净化,硅土/氧化铝柱层析,然后用气相色谱法测定其中三氯杀螨醇(DCF)。测定结果(10-9,湿重)显示:DCF含量在65.2%样本中低于检出限,在其余样本中为0.244～4.42,明显低于发达国家的最大残留限量和国际组织的容许摄入量。牡蛎体中DCF的区域平均含量在北部湾顶明显较高(1.41),在粤西(0.278)和海南岛(0.199)相对较低,在珠江口(0.769)高于总体平均含量(0.547),在粤东为0.466。牡蛎体DCF含量的年际变化明显,总体在2009年(0.778)明显高于2010年(0.489)和2008年(0.373),在不同区域、不同测站的年际变化大小不一。     

三氯杀螨醇生产过程中的DDT环境排放研究

三氯杀螨醇生产工艺流程主要包括缩合、碱解、氯化和水解等步骤。对工作场所中空气样品、生产过程排放的废酸及废水样品进行采集和分析。工作场所空气中DDT总质量浓度均值为6.69×10-3mg/m3。其中,碱解反应工序中质量浓度水平较低,为1.10×10-3mg/m3;包装车间质量浓度水平较高,为16.72×10-3mg/m3。所有空气样品中p,p’-DDE均是主要贡献物质,占DDT杂质总量的80.2%;p,p’-DDT的质量浓度范围为0.053×10-3~1.66×10-3mg/m3,平均为0.49×10-3mg/m3,低于国家标准限值。缩合废酸与水解废酸中DDT杂质总质量比分别为4.84μg/kg和334.83μg/kg;碱解废水与水解废水中的DDT杂质总质量比分别为456.48μg/kg和75.65μg/kg。废水及废酸样品中各种DDT杂质的质量比水平存在差异;生产工艺阶段不同,杂质组成也各具特点。水解废酸的p,p’-DDT的质量比最高,为146.82μg/kg;缩合废酸与水解废水处质量比水平较低,分别为0.33μg/kg和1.41μg/kg。该企业随废水及废酸排放的DDT杂质总量为1234.08 g/a,其中随碱解废水的排放量高达912.95 g/a。p,p’-DDT的年排放总量为163.37 g/a,随碱解废水和水解废酸的排放量分别为86.98 g/a和73.41 g/a。     

小鼠子宫增重法检测国产三氯杀螨醇的雌激素生物活性

为了解我国商品农药三氯杀螨醇是否具有明显的雌激素活性，利用整体给药方式检测了不同剂量三氯杀螨醇对未成熟小鼠子宫的作用。结果表明，较低剂量的三氯杀螨醇未使小鼠子明显增重，当剂量增加到４ｍｇ和８ｍｇ时，子宫重量明显增加，与对照组结果相比 ，有显著差异。     

三氯杀螨醇对泥鳅血清GST和AChE活力的影响

生化指标能更灵敏地反映环境污染的状况和危害程度,日益成为环境领域研究的热点.为研究三氯杀螨醇对泥鳅生化指标的影响,将泥鳅暴露于含不同剂量三氯杀螨醇的人工沉积物中,在暴露24、48和96 h后采集泥鳅血液样本,测定血清中谷胱甘肽硫转移酶(GST)和乙酰胆碱酯酶(AChE)的活力.结果表明:泥鳅在人工沉积物中暴露24和96...     

几种有机氯杀虫剂对鱼的毒性和残留效应

硫丹、氯丹、五氯苯酚、三氯杀螨醇等有机氯杀虫剂,只允许在特殊场合使用,禁止在动物养殖业使用,但在世界上普遍存在限而不严、禁而不止的状况,威胁渔业环境安全和水产品质量.中国是水产品的生产大国和重要输出国,鱼类是中国主要的水产品.本文概述这几种杀虫剂的用途、水环境行为、渔业生产中的来源、对鱼类的毒性、对渔业的影响、中国渔业...     

Teratogenic and biochemical effects of a formulation containing dicofol in the chick embryo

The insecticide formulation, dicofol (18.5% EC) was evaluated for its toxic potential in developing chick embryo. Fertilized eggs of Gallus domesticus on 4th day of incubation were immersed in aqueous emulsions of dicofol at concentrations of 250?mg?L^?1, 500?mg?L^?1, and 1000?mg?L^?1 for 60?min at 37°C. These concentrations were corresponding to those used in plant protection practice (500?mg?L^?1). Two control groups of eggs were used: one group was immersed in distilled water (vehicle) and the second group was kept as untreated to study background toxicity. On embryonic day 7; recovered embryos were evaluated for mortality rate, wet body weight, gross morphological malformations, and some biochemical changes. The result revealed that administration of dicofol did not result in significant changes in wet body weight of embryo but the survival rate of dicofol treated embryos were markedly reduced as compared with controls. Among the survivors, the number of malformations was exhibited by dicofol treated embryos in dose-dependent manner. Among biochemical changes, only total protein content of embryo significantly (p?≤?0.05) reduced to 500?mg?L^?1 and 1000?mg?L^?1. Among enzymes, alkaline phosphatase and glutamate pyruvate transaminase activities were affected, which showed significant elevations.     

Contents and sources of DDT impurities in dicofol formulations in Turkey

Background, aim, and scope  Dicofol is widely used as a pesticide in agriculture applications. Since dicofol is mainly synthesized from dichlorodiphenyltrichlorethane (DDT), it contains DDT as an impurity. The European Community has forced Prohibition Directive 79/117/EEC to reduce DDT in dicofol formulations. Specifically, DDT content in a dicofol formulation cannot exceed 0.1%. The goal of this project was to determine the DDT content in dicofol formulations used in Turkey. Materials and methods  Samples of all the dicofol formulations in Turkey were collected to quantify DDT and DDT-related compounds. Four replicates were used for each sample. GC/MS/MS was used to analyze p,p′ and o,p′ isomers of DDT, DDD, and DDE. A HPLC was used to determine p,p′-Cl-DDT concentrations. Results  The total DDT content of the formulated dicofol was found between 0.3% and 14.3%. The concentration of p,p′-DDE ranged from 167 to 1,042 mg kg⁻¹ in dicofol samples. p,p′-DDT concentrations were found to be 32 to 183 mg kg⁻¹. The o,p’-DDT level ranged from 2 to 34 mg kg⁻¹ in the dicofol formulations analyzed. Discussion  It was estimated that 617.8 kg of DDT was released from dicofol. The main impurity was identified as p,p-Cl-DDT. Based on these results, dicofol serves as a continuing source of DDT contamination. Conclusions  All DDT concentrations in dicofol samples analyzed were higher than the permitted 0.1% level of Prohibition Directive 79/117/EEC. The reduction of dicofol is critical since it serves as a continual source of DDT contamination. Recommendations and perspectives  DDT has been found in soil, water, and air samples. Dicofol has been identified as a contributor to continued DDT contamination in soil and water. More studies are needed to ascertain the source of DDT in the air.     

Selected endocrine disrupting compounds (Vinclozolin,Flutamide, Ketoconazole and Dicofol): Effects on survival,occurrence of males,growth, molting and reproduction of <Emphasis Type="Italic">Daphnia magna</Emphasis>

BACKGROUND, AIM AND SCOPE: Pollution-induced endocrine disruption in vertebrates and invertebrates is a worldwide environmental problem, but relatively little is known about effects of endocrine disrupting compounds (EDCs) in planktonic crustaceans (including Daphnia magna). Aims of the present study were to investigate acute 48 h toxicity and sub-chronic (4-6 days) and chronic (21 days) effects of selected EDCs in D. magna. We have investigated both traditional endpoints as well as other parameters such as sex determination, maturation, molting or embryogenesis in order to evaluate the sensitivity and possible use of these endpoints in ecological risk assessment. MATERIALS AND METHODS: We have studied effects of four model EDCs (vinclozolin, flutamide, ketoconazole and dicofol) on D. magna using (i) an acute 48 h immobilization assay, (ii) a sub-chronic, 4-6 day assay evaluating development and the sex ratio of neonates, and (iii) a chronic, 21 day assay studying number of neonates, sex of neonates, molting frequency, day of maturation and the growth of maternal organisms. RESULTS: Acute EC50 values in the 48 h immobilization test were as follows (mg/L): dicofol 0.2, ketoconazole 1.5, flutamide 2.7, vinclozolin >3. Short-term, 4-6 day assays with sublethal concentrations showed that the sex ratio in Daphnia was modulated by vinclozolin (decreased number of neonate males at 1 mg/L) and dicofol (increase in males at 0.1 mg/L). Flutamide (up to 1 mg/L) had no effect on the sex of neonates, but inhibited embryonic development at certain stages during chronic assay, resulting in abortions. Ketoconazole had no significant effects on the studied processes up to 1 mg/L. DISCUSSION: Sex ratio modulations by some chemicals (vinclozolin and dicofol) corresponded to the known action of these compounds in vertebrates (i.e. anti-androgenicity and anti-oestrogenicity, respectively). Our study revealed that some chemicals known to affect steroid-regulated processes in vertebrates can also affect sublethal endpoints (e.g. embryonic sex determination and/or reproduction) in invertebrates such as D. magna. CONCLUSIONS: A series of model vertebrate endocrine disrupters affected various sub-chronic and chronic parameters in D. magna including several endpoints that have not been previously studied in detail (such as sex determination in neonates, embryogenesis, molting and maturation). Evaluations of traditional reproduction parameters (obtained from the 21 day chronic assay). as well as the results from a rapid, 4-6 day, sub-chronic assay provide complementary information on non-lethal effects of suspected organic endocrine disrupters. RECOMMENDATIONS AND PERSPECTIVES: It seems that there are analogies between vertebrates and invertebrates in toxicity mechanisms and in vivo effects of endocrine disruptors. However, general physiological status of organisms may also indirectly affect endpoints that are traditionally considered 'hormone regulated' (especially at higher effective concentrations as observed in this study) and these factors should be carefully considered. Further research of D. magna physiology and comparative studies with various EDCs will help to understand mechanisms of action as well as ecological risks of EDCs in the environment.