六六六在生态环境中的行为特征与起用林丹的科学依据

本文根据80年代初中国生态环境中六六六的污染概况,特别是六六六各异构体在植物、动物样品中的残留水平,在土壤中的消解、被作物吸收和在食物链中生物浓缩的特     

枯草芽孢杆菌菌株Tpb55的安全性毒理学研究

对枯草芽孢杆菌菌株Tpb55的安全性进行了合理的评价,就菌粉Tpb55对试验动物进行了相关的毒理学试验。结果表明,菌株Tpb55对小鼠、大鼠急性经口LD50大于5000mg·kg-1,对大鼠急性经皮LD50大于5000mg·kg-1;对兔皮肤刺激强度为无刺激性,眼刺激平均指数48h后为0,眼刺激强度为无刺激性;对豚鼠致敏率为0,属I级弱致敏物,无致敏性;对小鼠骨髓嗜多染红细孢微核以及性染色体及常染色体单价体等3项致突变试验为阴性,说明菌株Tpb55没有致突变作用。     

微量林丹的离子阱气——质联用分析条件研究

以离子阱质谱分析微量林丹 ,通过对离子扫描范围、扫描周期、扫描次数、选择离子范围等条件的改变 ,分析信噪比及相似度的变化 ,探讨以气相色谱—离子阱质谱联机分析微量林丹的条件     

防止林丹无效体与油状物对环境体的污染

防止林丹无效体与油状物对环境体的污染蔡道基，刘玉凯，陶思明（南京环境科学研究所）（国家环保局自然保护司）林丹是由六六六提纯得到的高丙体六六六。如单凭药效与残留危害两个因素评价，它与六六六相比已起到了扬长避短的作用。然而，林丹的生产过程必须先合成六六六...     

二氯喹啉酸的生态毒理学研究进展

本文介绍了除草剂二氯喹啉酸的残留活性及其选择性机理,以及国内外有关二氯喹啉酸对陆生动物、水生生物、作物和土壤微生态影响方面的研究进展。     

棉铃虫对久效磷抗性的毒理学机制

就棉铃虫田间种群对久效磷抗性的毒理学机制进行了研究。久效磷对敏感品系和高抗品系的乙酰胆碱酯酶抑制率存在显著差异,在同等剂量浓度下,对敏感品系的抑制率为７３．４８％,对高抗品系的抑制率仅为５９．６７％,说明棉铃虫对久效磷产生高水平抗性与乙酰胆碱酯酶不敏感性有关。在不同田间抗性品系中,ＰＢＯ和ＴＰＰ对久效磷均具有明显的增效作用,增效比分别为５．６～２３．４倍和２．９～４．６倍;而相应地ＢＰＯ和ＴＰＰ对     

增效醚对棉铃虫的毒理学研究

本文以棉铃虫 3龄幼虫为试虫材料对增效醚 (PBO)的毒理学进行了研究。结果表明 ,PBO对棉铃虫(H elicoverp a armigera) 3龄幼虫的 L D50 为 5.7532 μg/ larva;在活体抑制实验中 ,用 4 μg/ larva的剂量点滴处理1h后 ,幼虫体内乙酰胆碱酯酶 ACh E的活性被抑制 4 8.31% ,羧酸酯酶 Carb E被抑制 4 4 .97% ,多功能氧化酶MFO被抑制 6 0 .82 % ;在离体抑制试验中 ,PBO对 ACh E、Carb E和 MFO的抑制中率 (I50 )分别为 3.35× 10 -7mol/ L、4 .4 6× 10 -7mol/ L和 1.4 2× 10 -7mol/ L ;PBO对酯酶的抑制为不可逆抑制。因此 ,PBO的增效机理在抑制代谢酶系的水平上并不是专一的 ;对于棉铃虫而言 ,PBO具有明显的杀虫活性 ,用其进行增效实验判断MFO是否参与抗性时应注意 PBO的这一特点 ;同时文章还证明了磷酸三苯酯 (TPP)和顺丁烯二酸二乙酯(DEM)抑制作用的专一性。     

Diffusive movement of simazine and lindane in river-bed sediments

River-bed sediments are active zones for pesticide deposition and subsequent movement by diffusion, mass transport and sorption to solids. The aim of this work was to investigate the importance of diffusion as a means of pesticide movement. In laboratory experiments, simazine and lindane were introduced to well-mixed aqueous solutions overlying two different river sediments. Sediment cores were sectioned horizontally and analyzed for pesticide content by supercritical fluid extraction. Experiments were used to determine sorption isotherms of the compounds to suspended sediments at 10°C. Vertical profiles of the pesticides in the sediments showed that the compounds reached a maximum depth of 89 mm over a period of 37 days. A mathematical model was developed to describe pesticide transport by diffusion within the sediment porewaters and sediment sorbed phases, taking into account sorption of the compounds to sediment particles. Effective diffusion coefficients ((0.5–1.6)×10^-10 m² s^-1) were obtained for simazine and lindane in the characterized sediments. These were used to calculate values for diffusion in the dissolved phase (0.38×10^-10 and 6·16×10^-10 m² s^-1 for simazine and lindane respectively) and diffusion in the sorbed phase (0.39×10^-10 m² s^-1 for simazine and negligible for lindane). Sorption onto the sediment significantly influenced the rate of penetration of the compounds into the sediment; thus although lindane had a larger effective diffusion coefficient than simazine, its larger sorption affinity and negligible diffusion in the sorbed phase led to less penetration into the sediment. © 1998 Society of Chemical Industry     

Degradation of insecticide lindane (γ‐HCH) by white‐rot fungi Cyathus bulleri and Phanerochaete sordida

An Erratum for this article has been published in Pest Management Science 56(5) 493 (2000). The degradation of the insecticide lindane (γ‐hexachlorocyclohexane, γ‐HCH) by two white‐rot fungi, Cyathus bulleri and Phanerochaete sordida, was studied. C bulleri degraded lindane more efficiently than P sordida. Two degradative intermediates identified in P sordida culture were tetrachlorocyclohexene and tetrachlorocyclohexanol. However, tetrachlorocyclohexanol was the sole degradation product detected in cultures of C bulleri. The presence of lindane only inside the mycelial cells of both fungi eliminated any role of intracellular enzymes during initial steps of its degradation. The insecticide at 0.27 µM showed no adverse effect on fungal growth. © 2000 Society of Chemical Industry     

Transport and distribution of lindane and simazine in a riverine environment: measurements in bed sediments and modelling

Aquatic sediments often remove hydrophobic contaminants from fresh waters. The subsequent distribution and concentration of contaminants in bed sediments determines their effect on benthic organisms and the risk of re-entry into the water and/or leaching to groundwater. This study examines the transport of simazine and lindane in aquatic bed sediments with the aim of understanding the processes that determine their depth distribution. Experiments in flume channels (water flow of 10 cm s(-1)) determined the persistence of the compounds in the absence of sediment with (a) de-ionised water and (b) a solution that had been in contact with river sediment. In further experiments with river bed sediments in light and dark conditions, measurements were made of the concentration of the compounds in the overlying water and the development of bacterial/algal biofilms and bioturbation activity. At the end of the experiments, concentrations in sediments and associated pore waters were determined in sections of the sediment at 1 mm resolution down to 5 mm and then at 10 mm resolution to 50 mm depth and these distributions analysed using a sorption-diffusion-degradation model. The fine resolution in the depth profile permitted the detection of a maximum in the concentration of the compounds in the pore water near the surface, whereas concentrations in the sediment increased to a maximum at the surface itself. Experimental distribution coefficients determined from the pore water and sediment concentrations indicated a gradient with depth that was partly explained by an increase in organic matter content and specific surface area of the solids near the interface. The modelling showed that degradation of lindane within the sediment was necessary to explain the concentration profiles, with the optimum agreement between the measured and theoretical profiles obtained with differential degradation in the oxic and anoxic zones. The compounds penetrated to a depth of 40-50 mm over a period of 42 days.     

丙溴磷、辛硫磷及其混剂对二化螟的毒力测定和田间药效试验

采有点滴法测定丙溴磷、辛硫磷及其混剂对二化螟的毒力,结果表明,丙溴磷与辛硫磷混配,各个配比均有增效作用,其中以6:19(有效成分)的配比增效作用最大,毒性比率和共毒系数分别为1.71和177.16。田间试验表明,丙溴磷与辛硫磷以6:19的混剂对二化螟有较好的防治效果,室内结果在田间试验中得到验证。     

毒死蜱、氟虫腈及其混剂对二化螟的毒力测定和田间药效试验

采用点滴法测定毒死蜱、氟虫腈及其混剂对二化螟的毒力,结果表明,毒死蜱与氟虫腈混配,各个配比均有增效作用,其中以16︰1和24︰1(有效成分)的配比增效作用最大,毒性比率和共毒系数分别为1.83-1.80和191.03-189.30。田间试验表明,毒死蜱与氟虫腈以16︰1和24︰1的混剂对二化螟有较好的防治效果,室内结果在田间试验中得到验证。     

阿维菌素，吡虫啉及其混剂对菜蚜的毒力测定和田间药效试验

采用浸渍法测定阿维菌素，吡虫啉及其混剂对菜蚜的毒力，阿维菌素与吡虫啉混配，各个配比均有增效作用，其中以LC50剂量1∶8的配比增效作用最大，毒性比率和共毒系数分别为1．82和194．20。阿维菌素与吡虫啉的混剂对菜蚜有较好的防治效果，室内结果在田间试验中得到验证。     

溴氟菊酯对环境生物的安全评价研究

按照“化学农药环境安全评价试验准则”的规定, 测定了溴氟菊酯对7 种环境生物的毒性。结果表明: 其对鸟类、蜜蜂和蚯蚓的毒性较低; 对鱼类属中等毒性; 对蚤类、藻类和家蚕属高毒性。由于溴氟菊酯用量少, 在环境中降解快, 因此在田间使用时对水生生物的实际危害要小得多, 但要严格防止对邻近桑树的污染。     

六种杀虫剂对家蚕的毒性与安全评价研究

在室内用毒叶接虫法、夹毒叶片法、触杀法及熏蒸法测定了 6种杀虫剂对家蚕Bombyx mori L .的毒性。结果表明 ,丁硫克百威、灭多威具有胃毒和中等的触杀毒性 ;氯氰菊酯、氰戊菊酯、氟虫腈、阿维菌素具有胃毒和触杀毒性 ;熏蒸作用对家蚕影响不大。 6种杀虫剂毒叶接虫法毒性比 (Toxic ratio)均小于 0.5 ,对家蚕的毒性极大 ,要严禁以任何方式在桑园及桑园附近的农田施用。     

吡虫啉对环境生物的毒性与安全性评价

本文采用多种室内模拟试验,测定了吡虫啉对蜜蜂、家蚕、蚤类、鱼类和虾类的毒性并作了安全性评价。结果表明,吡虫啉对蚤类和鱼类是安全的,但对家蚕和虾类属高毒农药,对蜜蜂的毒性极高。因此必须禁止在桑园附近及蜜蜂活动区域使用吡虫啉农药。若在田间使用吡虫啉时,一定要严防药液流入河塘,以免对虾类造成危害。