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31.
17β-estradiol (E2) is a female hormone which is known to be one of the strongest estrogenic chemicals in the environment. The present study investigated the effects of E2 on the reproduction of the estuarine fish, Java-medaka (Oryzias javanicus). Starting from the embryonic stages, Java-medaka was exposed for 6 months to 9.5, 16, 68, 159 and 243 ng/l of E2. The fecundity of Java-medaka exposed to E2 levels >16 ng/l was significantly lower than that of the control. The appearance of secondary sexual characteristics seemed to be inhibited by exposure to 159 and 243 ng/l E2. Vitellogenin concentrations in the liver of male fish exposed to 68, 159 and 243 ng/l were significantly higher than that of the control. Thirty-three and sixty percent of male fishes exposed to 159 and 243 ng/l, respectively, had testis-ova. These results suggest that reproduction in the Java-medaka, especially the male fish, could be affected by exposure to E2 concentrations greater than 16 ng/l.  相似文献   
32.
THE NATIONAL PATTERN OF AIRBORNE TOXIC RELEASES   总被引:1,自引:0,他引:1  
Incident-specific data reveal the spatial patterns of two major classes of acute toxic airborne releases in the United States (1982–86): rural agricultural and urban industrial. Rural (primarily truck transport) incidents dominate the distribution in the western US, while rail incidents and fixed site incidents dominate in the east. Using a combination of cartographic and statistical analyses, risk and mitigation measures were calculated to identify high-hazard and low-hazard states. Risk factors, primarily numbers of chemical firms and rail miles per state, best predict the frequency of incidents and their resulting spatial pattern.  相似文献   
33.
Perfluorinated chemicals including PFOA and PFOS have been widely used in consumer products and have become ubiquitous pollutants widely distributed in the aqueous environment. Following a major flood event in 2011, water samples were collected along a spatial gradient of the Brisbane River system to provide an initial estimate of the release of PFASs from flooded urban areas. PFOA (mean concentrations 0.13–6.1 ng L−1) and PFOS (mean concentrations 0.18–15 ng L−1) were the most frequently detected and abundant PFASs. Mean total PFASs concentrations increased from 0.83 ng L−1 at the upstream Wivenhoe Dam to 40 ng L−1 at Oxley Creek, representing an urban catchment. Total masses of PFOA and PFOS delivered into Moreton Bay from January to March were estimated to be 5.6 kg and 12 kg respectively. From this study, urban floodwaters appear to be a previously overlooked source of PFASs into the surrounding environment.  相似文献   
34.
几种生化信号物质对双壳类催产效应的研究   总被引:2,自引:0,他引:2  
采用个体注射的方法,研究不同的信号物质(五羟色胺、肾上腺素、去甲肾上腺素、多巴胺、Υ-氨基丁酸GABA、溴化乙酰胆碱)对双壳类催产的效应。结果表明:所选用的六种物质中,只有五羟色胺能有效地诱导菲律宾蛤仔、栉孔扇贝、贻贝的精卵排放。五羟色胺作用的有效浓度范围为10^-3 ̄10^-7mol/L,最佳作用浓度为10^-4mol/L。五羟色胺诱导的精卵排放具有作用潜伏期短(绝大部分在30min以内)、同步  相似文献   
35.
随着社会经济的快速发展,化学品生产种类不断丰富,沿海化工企业规模不断扩大,化学品泄漏入海对公共安全、经济发展和海洋环境造成的危害越来越突出,加强化学品泄漏入海应急辅助决策技术体系建设已成为当务之急。美国化学品应急响应体系处于世界领先地位,相关应急辅助决策技术体系较为完善。鉴于此,本文概述了CAMEO Chemicals、CAMEO suite风险源数据管理模块和CAFE化学品数据库的指标及其作用,ALOHA模拟和MARPLOT绘图软件的基本原理和功能,以期为中国化学品泄漏入海应急辅助决策技术体系提供较好的参考。  相似文献   
36.
Competitive sorption of estriol (E3) and 17α‐ethinylestradiol (EE2) was studied on activated charcoal. Better sorption of E3 (88.9%) and EE2 (69.5%) was observed with single‐solute sorption system than with bi‐solute sorption system. Single‐solute sorption kinetics of E3 and EE2 were evaluated with two (Langmuir and Freundlich) and three (dual mode and Song) parameter models. Freundlich model (R2, 0.9915 (E3); 0.9875 (EE2)) showed good prediction compared to other models for single‐solute sorption. Adsorption capacity documented reduced efficacy (86.4% (E3); 65.9% (EE2)) due to induced competitive behavior between the estrogens in aqueous phase. Bi‐solute adsorption kinetics of E3 and EE2 were described by IAST with two and three parameter models. Among these models, IAST‐Freundlich model (R2, 0.9765 (E3); 0.9985 (EE2)) was best in predicting bi‐solute sorption of E3 and EE2 by activated charcoal. All these models showed favorable representation of both single‐ and bi‐solute sorption behaviors.  相似文献   
37.
危险化学品运输车辆监控系统的设计与实现   总被引:1,自引:0,他引:1  
通过分析目前各级职能管理部门和危险化学品运输企业应用需求,以及危险化学品运输安全监控环节中存在的问题,借鉴国外先进经验,构建基于卫星导航定位技术和地理信息系统(GIS)的危险化学品运输车辆监控系统。设计了系统的层次结构,描述了系统的主要功能。提出了建立信息公共交换平台的关键技术,并对其进行了详细阐述。给出了系统运行时的界面效果。  相似文献   
38.
During the Soviet era, Ukraine was an important industrial and agricultural region of the Soviet Union. This industrial and agricultural activity resulted in contamination of Ukraine’s estuaries with legacy anthropogenic pollutants. Investigations on the toxicological effects of this estuarine contamination have been limited. For this research, we measured the toxicity of contaminated sediments from four Ukrainian estuaries to several aquatic organisms over 3 years. Sediment chemical analyses and whole sediment toxicity identification evaluations (TIEs) were also performed to determine the classes of contaminants contributing to toxicity. Toxic sediments were observed in several of the Ukrainian estuaries and chemical analyses of the sediments demonstrated anthropogenic contaminants were widely distributed. Contaminants were also detected in macrobenthic organisms collected from the sediments. Several lines of evidence, including TIEs, indicated hydrophobic organic chemicals (HOCs) were contributing substantially to observed toxicity. This information can guide environmental managers to prioritize portions of the estuaries requiring remediation.  相似文献   
39.
40.
Polychlorobiphenyls (PCB) and organochlorine (OC) pesticides are endocrine-disrupting chemicals (EDCs). The Italian Ministry of Environment has undertaken a program (1999-2001) to measure levels of contaminants in top marine predators and to develop sensitive biomarkers for the evaluation of toxicological risk in these species. In 1999, 15 swordfishes (Xiphias gladius) taken from the Mediterranean Sea along the Sicilian coast (Strait of Messina, Italy) and in the Atlantic Ocean along the Azores Islands, and analysed for 34 congeners of PCBs and 27 organochlorine (OC) pesticides in gonad, muscle, liver and blubber tissues. In the tissues of Mediterranean swordfishes the sum of the determined PCBs congeners ranged from 4.61 to 4651.17 ng g(-1) on fresh tissue basis. Among organochlorine pesticides DDE, DDT and DDD (TDE) predominated with an overall range of 2.37-4734.56 ng(-1) w.w. In particular p,p'-DDE had concentrations appearing up to 3900 ng(-1), with the highest values found in fatty tissues, such as blubber. In the liver of Azores Island swordfishes lower levels of summation PCBs (8.43-294.17 ng/g w.w.) and summation DDTs (<0.01-217.44 ng/g w.w.) were determined.  相似文献   
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