腹泻性贝毒素软海绵酸的昆明系小鼠生物学检测法的建立

为完善腹泻性贝毒素软海绵酸(Okadaic acid,OA)的小鼠生物学检测技术,以昆明系小鼠为实验材料,应用小鼠生物学检测法检测了OA的毒性.用不同浓度OA标准溶液通过腹腔注入19～21g昆明系小鼠体内,观察其中毒症状,确定1个鼠单位(MU)所代表的毒素剂量,并且建立剂量-死亡时间曲线.结果表明,昆明系小鼠经OA腹腔注射后中毒症状和死亡时间具有明显剂量效应关系,其剂量-死亡时间曲线方程为y=600.57x-2.257,其中y代表致死时间(h),x代表剂量(μg);将死亡时间t变为时间倒数1/t,对OA的毒性MU取对数(即logMU),得直线回归方程为y=0.5363x+0.1295,R2=0.9488,p<0.01,其中y代表OA毒素剂量单位的对数(1ogMU),x代表小鼠死亡时间倒数(1/t),R2为可决系数.通过该方程计算得出,1个鼠单位(MU)所对应的OA剂量值约为4.015μg,其95%置信限为3.826～4.204μg.     

北京市污水厂污泥中的内分泌干扰效应物质

采用重组基因酵母法检测了北京市16个污水处理厂污泥的雌激素、雄激素和孕激素效应.结果表明,各污水厂污泥中均可检测到雌激素受体诱导效应,范围在0.587～6.76ngEEQ·g-(1dw)之间.各水厂污泥均未检测出雄激素诱导效应和孕激素诱导效应,大部分污水厂污泥样品表现出较明显的雄激素抑制效应和较强的孕激素抑制效应.与国外相比,北京市污水厂污泥中的雌激素活性值相对较低.堆肥处理不能有效去除雌激素类物质和孕激素抑制物质,但对雄激素抑制物质的去除明显.     

紫外线消毒系统中强度分布的理论计算与生物验证对比

应用以MPSS模型为基础的计算软件UV calc对某饮用水紫外线消毒反应器进行强度分布的计算,同时,采用枯草芽孢杆菌(ATCC9372)作为受试菌种进行生物验证.结果显示,在该反应器中理论计算数值总体上明显高于生物验证的数值,反应器中最低紫外剂量区域出现在2支灯管之间的反应器壁附近.另外,理论计算和生物验证的误差与流量、透光率具有相关性.在高流量、低透光率的情况下,理论计算的数值更接近于生物验证数值.相对于理论计算,生物验证是确定紫外线反应器剂量反应曲线的可靠方法.     

Ecotoxicological Assessment of Sediment, Suspended Matter and Water Samples in the Upper Danube River. A pilot study in search for the causes for the decline of fish catches (12 pp)

Goals, Scope and Background Fish populations, especially those of the grayling (Thymallus thymallus), have declined over the last two decades in the upper Danube River between Sigmaringen and Ulm, despite intensive and continuous stocking and improvement of water quality since the 1970s. Similar problems have been reported for other rivers, e.g. in Switzerland, Great Britain, the United States and Canada. In order to assess if ecotoxicological effects might be related to the decline in fish catch at the upper Danube River, sediment, suspended matter and waste water samples from sewage treatment plants were collected at selected locations and analyzed in a bioanalytical approach using a battery of bioassays. The results of this pilot study will be used to decide if a comprehensive weight-of-evidence study is needed. Methods Freeze-dried sediments and suspended particulate matters were extracted with acetone in a Soxhlet apparatus. Organic pollutants from sewage water were concentrated using XAD-resins. In order to investigate the ecotoxicological burden, the following bioassays were used: (1) neutral red assay with RTL-W1 cells (cytotoxicity), (2) comet assay with RTLW1 cells (genotoxicity), (3) Arthrobacter globiformis dehydrogenase assay (toxicity to bacteria), (4) yeast estrogen screen assay (endocrine disruption), (5) fish egg assay with the zebrafish (Danio rerio; embryo toxicity) and (6) Ames test with TA98 (mutagenicity). Results and Discussion The results of the in vitro tests elucidated a considerable genotoxic, cytotoxic, mutagenic, bacteriotoxic, embryotoxic and estrogenic burden in the upper Danube River, although with a very inhomogeneous distribution of effects. The samples taken from Riedlingen, for example, induced low embryo toxicity, but the second highest 17β-estradiol equivalent concentration (1.8 ng/L). Using the fish egg assay with native sediments, a broad range of embryotoxic effects could be elucidated, with clear-cut dose-response relationships for the embryotoxic effects of contaminated sediments. With native sediments, embryotoxicity was clearly higher than with corresponding pore waters, thus corroborating the view that – at least for fish eggs – the bioavailability of particle-bound lipophilic substances in native sediments is higher than generally assumed. The effect observed most frequently in the fish egg assay was a developmental delay. A comparison of our own results with locations along the rivers Rhine and Neckar demonstrated similar or even higher ranges of ecotoxicological burdens in the Danube River. Conclusions The complex pattern of ecotoxicological effects caused by environmental samples from the Danube River, when assessed in an in vitro biotest battery using both acute and more specific endpoints, showed that integration of different endpoints is essential for appropriate hazard assessment. Overall, the ecotoxicological hazard potential shown has indeed to be considered as one potential reason for the decline in fish catches at the upper Danube River. However, based on the results of this pilot study, it is not possible to elucidate that chemically induced alterations are responsible for the fish decline. Recommendations and Perspective . In order to confirm the ecological relevance of the in vitro results for the situation in the field and especially for the decline of the grayling and other fishes, further integrated investigations are required. For linking the weight of evidence obtained by in vitro assays and fish population investigations, the application of additional, more specific biomarkers (e.g. vitellogenin induction, EROD and micronucleus assay) has been initiated in fish taken from the field as well as in situ investigations.     

应用黑褐新糠虾测试织纹螺毒性的初步研究

尝试以黑褐新糠虾作为实验生物,研究了投喂不同毒性的织纹螺对糠虾存活的影响,并探讨了这一方法在织纹螺毒性测试中的应用.实验结果表明:有毒织纹螺能够导致黑褐新糠虾中毒死亡,糠虾的半致死时间与织纹螺的毒性之间有显著的相关性(R2=0.9943),在96 h内织纹螺对糠虾的半致死毒性为40.11 MU/g.利用黑褐新糠虾作为实验生物可以测试织纹螺样品毒性的高低,方法的检出限约为10.44 MU/g,与日本法定的河豚鱼食用安全标准(10 MU/g)相当.