二苯甲酮对斑点叉尾鮰鱼卵巢细胞生长的影响

试验通过直接、间接两种染毒手段来探讨二苯甲酮(benzophenone)对斑点叉尾鮰鱼卵巢细胞(CCO)生长的影响,以MTT法为手段测定染毒前后CCO细胞的存活数量和各阶段的生长状态,结果发现:当二苯甲酮以1～10μg/mL的浓度直接作用于CCO细胞时,CCO细胞生长在不同阶段均受到抑制作用:在指数增长期细胞生长速率减小,稳定期的存活量约为正常条件下的72%～91%,并且随着二苯甲酮浓度的增大,对CCO生长的抑制效应也相应的加剧;但是1μg/mL浓度的二苯甲酮在经过斑点叉尾鮰鱼原代肝细胞代谢后间接作用时,其代谢产物对CCO的生长在各阶段又呈现明显的促进作用,稳定期细胞数量约为正常条件下的109%。     

8种拟除虫菊酯农药对稀有鲫的急性、亚慢性毒性研究

８种拟除虫菊酯对稀有鲫的急性毒性和其中２种拟除虫菊酯的亚慢性毒性研究结果表明：溴氰菊酯、高效氯氰菊酯、氯氰菊酯、甲氰菊酯、氰戊菊酯、二氯炔戊菊酯、胺菊酯、甲醚菊酯对稀有鲫均属剧毒，它们的ρ（９６ｈＬＣ５０）／μｇ·Ｌ－１分别为３．１６，３．２４，６．３１，７．２１，７．３５，３２．４５，９１．７５和８８２．６；甲氰菊酯、二氯炔戊菊酯对稀有鲫７ｄ亚慢性毒性的最低有影响浓度ρ（ＬＯＥＣ）和最高无影响浓度ρ（ＮＯＥＣ）分别为０．８８～０．４４μｇ／Ｌ，４．０～２．０μｇ／Ｌ，以ρ（９６ｈＬＣ５０）／μｇ·Ｌ－１为基准，２种拟除虫菊酯的安全系数均为０．０６～０．１２５．     

Enantioselectivity in toxicity and degradation of dichlorprop-methyl in algal cultures

Enantioselectivity in the toxicity and degradation of the herbicide dichlorprop-methyl (2,4-DCPPM) in algal cultures was studied. Enantioselectivity was clearly observed in the toxicity of racemic 2,4-DCPPM and its two enantiomers. R-2,4-DCPPM showed low toxicity to Chlorella pyrenoidosa and Chlorella vulgaris, but higher toxicity to Scenedesmus obliquus. The observed toxicity was ranked: R-2,4-DCPPM > S-2,4-DCPPM ? Rac-2,4-DCPPM; the toxicity of R-2,4-DCPPM was about 8-fold higher than that of Rac-2,4-DCPPM. Additionally, 2,4-DCPPM was quickly degraded, in the initial 12 h, and different algae cultures had different enantioselectivity for the 2,4-DCPPM enantiomers. There was no significant enantioselectivity for 2,4-DCPPM in Chlorella vulgaris in the initial 7 h. However, racemic 2,4-DCPPM was degraded by Scenedesmus obliquus quickly, in the initial 4 h, much quicker, in fact, than the S- or R-enantiomers (racemate > R- > S-), indicating that the herbicide 2,4-DCPPM was absorbed enantioselectively by Scenedesmus obliquus. The rapid formation of 2,4-DCPP suggested that 2,4-DCPPM adsorbed by algal cells was catalytically hydrolyzed to the free acid, a toxic metabolite. The production rates of 2,4-DCPP were as follows: Scenedesmus obliquus > Chlorella pyrenoidosa > Chlorella vulgaris, consistent with the degradability of 2,4-DCPPM. Scenedesmus obliquus had quick, but different, degradative and uptake abilities for R-, S-, and Rac-2,4-DCPPM. The R- and S- enantiomers were not hydrolyzed in the first 12 h, while both enantiomers were hydrolyzed slowly after that. These results indicate that some physical and chemical properties of compounds are of importance in determining their enantioselective toxicity and degradation. The ester and its metabolite likely played an important role in enantioselective toxicity to the three algae.     

Toxicity testing with luminescent bacteria – Characterization of an automated method for the combined assessment of acute and chronic effects

The luminescent bacteria test according to EN ISO 11348 is frequently applied in (eco) toxicity testing and is applicable for a huge variety of environmental and industrial samples. A big disadvantage of this method is the very short exposure time, which is expressed in a low sensitivity in regard to substances with a delayed effect. Chronic effects, i.e. interference with cell growth, cannot be assessed with this conventional standard method. The goal of this research was to develop an automated testing system for long term toxicity towards the luminescent bacteria Vibrio fischeri by implementing microtitration-based instrumentation. The optimized method, hereinafter referred to as “kinetic luminescent bacteria test”, can be described as a miniaturized combination of the conventional short-term luminescence inhibition test according to EN ISO 11348 and the Photobacterium phosphoreum growth inhibition test (DIN 38412-37). The validation procedure included the evaluation of six reference compounds (3,4-Dichloroaniline, 3,5-Dichlorophenol, Chloramphenicol, Streptomycin sulfate, Potassium dichromate, Zinc sulfate heptahydrate) and three different endpoints that are acute luminescence inhibition (acute LI) after 30 min, chronic luminescence inhibition (chronic LI) after 24 h and growth inhibition (GI) after 14 h. The optimized method allows the assessment of acute and chronic effects within one test, by what a misinterpretation of the toxicity of substances with delayed bacterial toxicity can be prevented, without abandoning most of the advantages of the conventional short-term test. Therefore, the kinetic luminescent bacteria test is exceptional as an initial screening test for environmental samples or substances with unknown (eco) toxicological characteristics.     

Study on acute toxicity and structure-activity relationship of zebrafish (Danio rerio) exposed to naphthoquinones

In this paper, we evaluated the acute toxicity of five naphthoquinone compounds, expressed as median lethal concentration at 96 h (LC₅₀) using zebrafish as a model. The five compounds were classified as harmful or very toxic. The Gaussian method was used to calculate the quantitative-chemical parameters of each compound. Based on the structure-activity relationship analysis, the interaction between the naphthoquinones and the target is likely mediated by 1-carbonyl and the hydrophobic fraction substituted in α -position of naphthoquinone via hydrogen bonding and hydrophobic interactions. Our results provide a foundation for evaluating the aquatic ecological risk and the mode of action of naphthoquinones in the environment.     

基于荧光素酶发光体系测试饮用水中农药的综合毒性

利用农药对荧光素酶催化的发光反应具有非常显著的抑制作用,对甲拌磷、乐果、毒死蜱、百草枯等4种农药分别进行单一毒性和等比混合法联合毒性测试,建立了一种快速检测饮用水中农药综合毒性的生物学方法。试验结果表明,单一农药乐果、甲拌磷、百草枯和毒死蜱的EC50值分别为7.56 mg/L、12.7 mg/L、19.0 mg/L和65.3 mg/L,毒性强弱顺序为乐果甲拌磷百草枯毒死蜱,相关系数≥0.995;将4种农药以等比方式配制成两两混合液后,当质量浓度为20.0 mg/L~100 mg/L时,除百草枯与毒死蜱表现为毒性协同外,其他两两混合农药的毒性以拮抗作用为主。     

Control of blueberry thrips,frankliniella vaccinii morgan,with permethrin and effect on yield and residue in fruit

Abstract

Permethrin at 0.4 kg a.i./ha controlled blueberry thrips Frankliniella vaccinii Morgan. There was no plant damage and crop yield was notably increased. Permethrin was extracted from berries with acetone, partitioned in hexane, cleaned‐up on Florisil column and analysed by the electron capture gas chromatography using a 3% OV‐210 column. No permethrin residues were found in the berries. The relative retention times of cis‐, and trans‐permethrins to aldrin were 10.3 and 12.1, respectively. The absence of permethrin from berries was further confirmed by TLC.     

京杭运河(苏州段)水质急性综合毒性研究

从2009年3月至2010年10月对京杭运河(苏州段)的4个监测断面进行了水质急性综合毒性和地表水主要理化项目的调查,结果表明:京杭运河(苏州段)水质急性综合毒性基本处在低毒水平,各断面基本呈现水质急性毒性水平枯水期>平水期>丰水期的规律,水质急性综合毒性测定结果基本与同步理化监测结果一致。     

Discrimination of excess toxicity from narcotic effect: Comparison of toxicity of class-based organic chemicals to Daphnia magna and Tetrahymena pyriformis

The discrimination of excess toxicity from narcotic effect plays a crucial role in the study of modes of toxic action for organic compounds. In this paper, the toxicity data of 758 chemicals to Daphnia magna and 993 chemicals to Tetrahymena pyriformis were used to investigate the excess toxicity. The result showed that mode of toxic action of chemicals is species dependent. The toxic ratio (TR) calculated from baseline model over the experimentally determined values showed that some classes (e.g. alkanes, alcohols, ethers, aldehydes, esters and benzenes) shared same modes of toxic action to both D. magna and T. pyriformis. However, some classes may share different modes of toxic action to T. pyriformis and D. magna (e.g. anilines and their derivatives). For the interspecies comparison, same reference threshold need to be used between species toxicity. The excess toxicity indicates that toxicity enhancement is driven by reactive or specific toxicity. However, not all the reactive compounds exhibit excess toxicity. In theory, the TR threshold should not be related with the experimental uncertainty. The experimental uncertainty only brings the difficulty for discriminating the toxic category of chemicals. The real threshold of excess toxicity which is used to identify baseline from reactive chemicals should be based on the critical concentration difference inside body, rather than critical concentration outside body (i.e. EC₅₀ or IGC₅₀). The experimental bioconcentration factors can be greatly different from predicted bioconcentration factors, resulting in different toxic ratios and leading to mis-classification of toxic category and outliers.     

工业废水毒性评估方法与应用研究进展

针对中国缺乏规范的工业废水毒性评估体系的现状，系统归纳了国外在毒性检测、毒性评价标准与方法方面的成功经验。在明确了工业废水急性毒性检测的重要性基础上，重点分析了美国全废水毒性测试法（WET）及其在工业废水评价中的应用；并结合对毒性评价标准的阐述，系统总结了发展较成熟的毒性鉴别评价法（TIE）和效应导向分析法（EDA）的流程与应用实例，以期为中国工业废水毒性检测评估和监管提供参考。