卤代芳烃对水生生物急性毒性的定量构效关系研究

提出表征成键原子生物活性的点价βi，由βi建构新的价连接性指数^nH，并用0阶指数^0H，1价指数^1H研究了卤代芳烃(含F、Cl、Br、OH、NH2、NO2和烷基等)对发光菌、呆鲦鱼、斜生栅列藻的急性毒性，给出了相关方程。结果表明，新方法计算简单，应用方便，估算结果均优于相应的文献方法。     

几种农药对鲤鱼脑AchE的联合毒性效应

采用体内染毒的方法,以鲤鱼脑乙酰胆碱酯酶(AchE)活力为指标,研究了有机磷农药对硫磷与氯乐果、甲胺磷涕灭威之间的联合毒性效应.结果表明,这些农药之间均产生较强的协同作用,但是两种农药以不同比例加入,其产生的毒性效应有明显差别,涕灭威/对硫磷之间的协同作用要强于同类农药间的作用.     

卤代芳烃对水生生物急性毒性的定量构效关系研究

提出表征成键原子生物活性的点价 βi,由 βi 建构新的价连接性指数nH ,并用 0阶指数0 H ,1价指数1H研究了卤代芳烃 (含F、Cl、Br、OH、NH2 、NO2 和烷基等 )对发光菌、呆鲦鱼、斜生栅列藻的急性毒性 ,给出了相关方程。结果表明 ,新方法计算简单 ,应用方便 ,估算结果均优于相应的文献方法     

11种农药对淡水发光细菌青海弧菌Q67的毒性研究

以淡水发光细菌青海弧菌Q67作为测试菌剂,利用水质毒性分析仪对11种农药进行了毒性研究,获得11种农药与青海弧菌的剂量-效应关系.结果表明,作用时间为15 min时,5种可溶农药对青海弧菌Q67的毒性大小为敌敌畏＞敌百虫＞杀虫单＞乐果＞乙酰甲胺磷,6种难溶于水农药的毒性大小为甲氨基阿维菌素＞甲胺磷＞莎稗磷＞高效氯氰菊酯...     

常见拟除虫菊酯和有机磷农药对鱼类的急性及其联合毒性研究

以崇明岛前卫村中心湖中鲫鱼、鲤鱼、鲢鱼及泥鳅作为实验动物.进行了氯氰菊酯(原药和商品)、氰戊菊酯(原药和商品)、毒死蜱(原药和商品)、甲氰菊酯(商品)、溴氰菊酯(商品)、辛硫磷(商品)以及乙酰甲胺磷(商品)7种供试农药对实验鱼种的急性毒性及联合毒性实验,并检测了前卫村中心湖水体中18种有机磷农药和4种拟除虫菊酯农药,其中检出了1种有机磷农药(毒死蜱)和3种拟除虫菊酯农药(氰戊菊酯、氯氰菊酯、甲氰菊酯).结果表明,在单一农药急性毒性实验中,鲤鱼对供试农药表现较敏感,其次是鲫鱼和鲢鱼,而泥鳅对农药的耐药性最强;7种供试农药中,拟除虫菊酯农药相对于有机磷农药表现出较高的急性毒性,其实验鱼种的半数致死浓度(LC60)皆在μg/L级;对拟除虫菊酯农药(氯氰菊酯,氰戊菊酯)与有机磷农药(辛硫磷、乙酰甲胺磷)进行的联合毒性实验结果表明,除了暴露时间为24、48 h时氰戊菊酯与辛硫磷混配对鲢鱼的毒性实验表现为协同作用外,其余皆为拈抗作用.     

农药对藻类的生态毒理学研究Ⅱ:毒性机理及其富集和降解

随着对农药污染认识的深入,农药对生态系统的初级生产者———藻类毒性以及毒性机制的研究不断增多。农药对藻类的毒性在于破坏藻类生物膜的结构和功能、影响藻类的光合作用、改变呼吸作用以及固氮作用,影响藻类的生理进程并改变其生化组分。开展农药对藻类毒性机理的研究,揭示农药结构—活性关系,对农药的研制和应用,评价农药的生态风险,减少农药对藻类的毒害是重要的。在自然环境中还发现藻能富集和降解农药。因此,对于这些藻来说,农药对藻类的毒害作用和藻类对农药的富集和降解作用可能同时存在。本文综述了农药对藻类的毒性机理以及藻类对农药的富集和降解作用。     

酯类化合物对四膜虫毒性的拓扑研究

提出了拓扑方法,即考虑分子图顶点的性质,直接用酯类化合物的分子碎片的特征值为主元来构建邻接矩阵。定义并计算了酯类化合物的修正的氢连接性指数^mHA及其倒指数^mHB,分析了30个酯化合物对四膜虫的毒性与分子结构之间的关系,结果表明由酯化合物对四膜虫毒性与^mH的回归方程得出的估算值与实验测定值之间能较好地吻合,平均误差为0．22。     

等浓度配比法研究苯酚、硝基苯和间硝基苯胺对发光菌的联合毒性作用

分别测定了苯酚、硝基苯和间硝基苯胺对发光菌的单一毒性,以及等浓度配比和等毒性配比的二元及三元混合体系的联合毒性,采用相加指数法对其联合效应进行了评价。结果表明,等浓度比和等毒性比混合体系的联合作用结果一致:苯酚+间硝基苯胺二元体系为协同作用,其他各体系为相加作用。为简化联合毒性实验方法,建议在研究相关系列化合物的联合毒性作用机制中,可采用等浓度配比方法。     

酚类化合物对硝化颗粒污泥活性抑制的定量结构 活性相关研究

测定了酚类化合物对硝化颗粒污泥活性抑制的logIC₅₀值,以量子化学参数为自变量,应用偏最小二乘法（PLS）,建立了酚类化合物对硝化颗粒污泥活性抑制的定量结构活性相关（QSAR）模型。模型所提取的PLS主成分所能解释的因变量总方差的比例Q²_cum为0.820,表明模型具有较好的稳定性和预测能力。模型的结果表明,影响酚类化合物对硝化颗粒污泥活性抑制的主要因素是logkow、CCR和E_homo,酚类化合物对硝化颗粒污泥活性抑制的logIC₅₀随着分子logkow的增大而减小,随着E_homo和CCR的增大而增大。     

酚类化合物对硝化颗粒污泥活性抑制的定量结构-活性相关研究

测定了酚类化合物对硝化颗粒污泥活性抑制的logIC50值,以量子化学参数为自变量,应用偏最小二乘法（PLS）,建立了酚类化合物对硝化颗粒污泥活性抑制的定量结构-活性相关（QSAR）模型。模型所提取的PLS主成分所能解释的因变量总方差的比例Qc2um为0.820,表明模型具有较好的稳定性和预测能力。模型的结果表明,影响酚类化合物对硝化颗粒污泥活性抑制的主要因素是logkow、CCR和Ehomo,酚类化合物对硝化颗粒污泥活性抑制的logIC50随着分子logkow的增大而减小,随着Ehomo和CCR的增大而增大。     

Electric arc furnace flue dust: characterisation and toxicity with Photobacterium phosphoreum

During steelmaking in electric arc furnaces (EAFs), 10 to 15 kg of dust, consisting of a mixture of zinc, lead and iron oxides and to a lesser degree chrome, nickel and manganese, is generated per ton of steel product. In many countries, the disposal of EAF dust in landfill sites is regarded as an environmental hazard, since toxic metals may be leached into drinking water supplies. This work gives the results of a study of the physical, chemical, mineralogical and toxicological properties of dust produced in Spanish EAFs. EC50 concentrations (Microtox Assay) are determined by studying the incubation time of the bacteria and an exponential ratio is then established between EC50 values and the heavy metal content of the leachates which are obtained (US EPA protocol). The relationship between the pH at which the metals are extracted and their ecotoxicity is also studied. Average EC50 values of 1 250 mg 1^-1 are found when the heavy metals are extracted at a pH of 4-4.5.     

The joint effects of sulfonamides and their potentiator on Photobacterium phosphoreum: differences between the acute and chronic mixture toxicity mechanisms

Organisms are typically exposed to mixtures of chemicals over long periods of time; thus, chronic mixture toxicity analysis is the best way to perform risk assessment in regards to organisms. However, most studies focus on the acute mixture toxicity. To investigate the difference between chronic mixture toxicity and acute mixture toxicity, Photobacterium phosphoreum were exposed to chronic (24 h exposure) and acute (15 min exposure) toxicity of single sulfonamide (SA) and their potentiator (trimethoprim, TMP), both individually and mixtures (SA with TMP). A comparison of chronic vs. acute mixture toxicity revealed the presence of an interesting phenomenon, that is, that the joint effects vary with the duration of exposure; the acute mixture toxicity was antagonistic, whereas the chronic mixture toxicity was synergistic. Based on the approach of Quantitative Structure Activity Relationships (QSARs) and molecular docking, this phenomenon was proved to be caused by the presence of two points of dissimilarity between the acute and chronic mixture toxicity mechanism: (1) the receptor protein of SAs in acute toxicity was Luc, while in chronic toxicity it was Dhps, and (2) there is a difference between actual concentration of binding-Luc in acute toxicity and individual binding-Dhps in chronic toxicity. This deep insight into the difference between chronic and acute mixture toxicity will benefit environmental science, medical science, and other disciplines. The existence of these differences poses a challenge for the assessment of routine combinations in medicine, risk assessment, and mixture pollutant control, in which, previously, only a synergistic effect has been observed between SA and their potentiator.     

等浓度配比法研究苯酚、硝基苯和问硝基苯胺对发光菌的联合毒性作用

分别测定了苯酚、硝基苯和间硝基苯胺对发光菌的单一毒性，以及等浓度配比和等毒性配比的二元及三元混合体系的联合毒性，采用相加指数法对其联合效应进行了评价。结果表明，等浓度比和等毒性比混合体系的联合作用结果一致：苯酚＋间硝基苯胺二元体系为协同作用，其他各体系为相加作用。为简化联合毒性实验方法，建议在研究相关系列化合物的联合毒性作用机制中，可采用等浓度配比方法。     

Comparative acute toxicities of selected pesticides to Anguilla anguilla

Abstract

The acute toxicities (24, 48, 72 and 96 hr) of eight pesticides to Anguilla anguilla were determined. The organochlorine pesticide, endosulfan was the most toxic, with LC50 values in the range of 0.042 to 0.041 mg/L Endosulfan was followed in order of decreasing toxicity by diazinon, fenitrothion, chlorpyrifos, lmdane, methidathion, trichlorfon and methylparathion. When fishes were exposed to the pesticides tested they exhibited signs of restlessness, erratic swimming, convulsions and difficulty in respiration. This response was more persistent in fishes exposed to organophosphorus pesticides.     

Comparative acute toxicities of selected pesticides to Anguilla anguilla.

The acute toxicities (24, 48, 72 and 96 hr) of eight pesticides to Anguilla anguilla were determined. The organochlorine pesticide, endosulfan was the most toxic, with LC50 values in the range of 0.042 to 0.041 mg/L. Endosulfan was followed in order of decreasing toxicity by diazinon, fenitrothion, chlorpyrifos, lindane, methidathion, trichlorfon and methylparathion. When fishes were exposed to the pesticides tested they exhibited signs of restlessness, erratic swimming, convulsions and difficulty in respiration. This response was more persistent in fishes exposed to organophosphorus pesticides.