Aquatic toxicity of cartap and cypermethrin to different life stages of Daphnia magna and Oryzias latipes

Cartap and cypermethrin, which are among the most widely used pesticides in many countries, are considered safe because of their low mammalian toxicity and their low persistence in the environment. However, recent findings of endocrine-disrupting effects and developmental neurotoxicity have raised concerns about the potential ecological impacts of these pesticides. We evaluated the aquatic toxicity of cartap [S,S′-(2-dimethylaminotrimethylene) bis(thiocarbamate), unspecified hydrochloride] and cypermethrin [(RS)-alpha-cyano-3-phenoxybenzyl-(1RS,3RS,1RS,3SR)-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylate], both individually and combined, on different life stages of the freshwater cladoceran Daphnia magna and a freshwater teleost, Japanese medaka (Oryzias latipes). The 96-hr Daphnia median effective concentrations (EC50s) for cartap and cypermethrin were 91.0 μ g/L and 0.00061 μ g/L, respectively. Rapid recovery of Daphnia was observed after short-term pulsed exposure to cartap and cypermethrin; there were no adverse effects on reproduction or survival 20 d after a 24 hr exposure to cartap up to 1240 μ g/L and cypermethrin up to 1.9 μ g/L. Chronic continuous exposure (for 21 d) of 7-d-old Daphnia to cypermethrin significantly reduced the intrinsic population growth rate in a concentration-dependent manner. However, because the intrinsic population growth rates were all above zero, populations did not decrease even at the highest experimental concentration of 200 ng/L. Exposure of Daphnia neonates (< 24 hr old) to cypermethrin for 21 d caused significant, sub-lethal reproduction-related problems, such as increased time to first brood, reduced brood size, and reduced total brood number, at 0.0002, 0.002, and 0.2 ng/L cypermethrin, but the intrinsic population growth rate was not significantly affected. Oryzias latipes was relatively more resistant to both pesticides. In particular, embryos appeared to be more resistant than juveniles or adults, which may be partly due to the protective role of the chorion. The incidence of larval fish deformity was significantly higher after a 96 hr exposure to as low as 250 μ g/L of cartap or 40 μ g/L of cypermethrin. The mixture of both compounds showed no synergistic toxicity. The extremely high acute-to-chronic ratio suggests that the standard acute lethal toxicity assessment might not reflect the true environmental hazards of these frequently used pesticides. Ecological hazard assessments of long-term low dose or pulsed exposures to cartap and cypermethrin may reveal more realistic consequences of these compounds in surface water.     

钒渣中钒的浸出特性

对制钒浸出工序进行研究,了解钒渣中钒残留比率及钒含量的变化范围,并对随州、竹山、郧西等地钒厂在不同生产工艺、不同堆放深度、不同排渣年份条件下的钒渣中钒的浸出特性进行了研究。结果表明,渣样中钒含量分布于3.5mg/L～30mg/L,钒在渣中残留比约为4.5%～5.6%,钠化焙烧渣钒含量高于钙化焙烧渣。与砷毒性的类比结果说明,不能排除钒渣属于危险废物的可能。     

汞和硒对剑尾鱼的急性毒性及其安全浓度评价

用重金属汞(Hg+2) 和硒(Se+4) 对剑尾鱼(Xiphophorus helleri)进行急性毒性和联合毒性的实验。其目的在于评价水环境中Hg+2和Se+4对鱼类的影响,为制订渔业水质标准提供参考数据。结果表明:Hg+2对剑尾鱼的 24、48、96 h的 LC50分别为 1.71、1.35、0.84mg/L;Se+4对剑尾鱼24、48、96 h的Lc50分别为17.91、12.59、6.64 mg/L;在浓度和毒性比都为1∶1的条件下,24 h都表现联合作用,而48 h、96 h则为拮抗作用。剑尾鱼对Hg和Se的最大容许浓度分别为:0.0084和0.064 mg/L。结果还表明:剑尾鱼幼体对Hg和Se敏感,是一种较理想的环境污染指示生物。     

Toxicity of Heavy Metals on Scenedesmus quadricauda (Turp.) de Brébisson in Batch Cultures (7 pp)

Background Aquatic environments are often exposed to various pollutants like heavy metals that are released from industrial, agricultural and domestic wastes. Emissions of heavy metals can then enter all ecosystems and bring about severe problems in plants, especially algae depending on the concentrations of a given element. The objective of the investigation presented is to detect toxic effects due to some heavy metals in the biomass of green alga Scenedesmus quadricauda. Methods All experiments were conducted with axenic cultures of the green alga Scenedesmus quadricauda (Turp.) de Brebisson (Chlorococcales, Chlorophyta). The cultures were grown in Chu-no.10 medium, and optimum physical and chemical growth conditions were provided to get higher growth rates and lower doubling times of cells. Growth of the micro algal cultures was measured on a daily schedule by counting cultures and determination of chlorophyll-a. The sterile-filtered heavy metal concentration solutions (Cd, Pb and Cu) were prepared and added as stock solutions of their salts (CdCl2*2.5 H2O, Pb(NO3)2*H2O and CuSO4*5 H2O). Results and Discussion The growth decreased gradually with the alga exposed to Cd at 0.05, 0.1, and 0.5 mg/L in comparison with the control whereas 1 mg/L Cd2+ had a clearly destructive effect. The growth was decreased with Pb at 15, 20 and 25 mg/L gradually, while at 30 mg/L the effect was more pronounced. When Cu was used, the growth was increased gradually at 0.5, 1 and 1.5 mg/L and vice versa at 2 mg/L. Conclusion There were differences in toxic effects of the metals with different metal as well as their concentrations and the time of exposure.     

基于犹豫直觉模糊集-TOPSIS的危险品多式联运风险评估

为了对危险品的多式联运系统风险进行评估,首先在"人、机、管、环"4M理论的基础上,将多式联运中"转运"这一特殊流程考虑进去,以"人、机、管、环、转运"这5个因素作为决策问题中的属性;其次,采用犹豫直觉模糊语言集为决策者的初始决策矩阵赋值,并利用均值-标准差的汉明距离来衡量两个犹豫直觉模糊语言数之间的距离;然后,以危险品多式联运系统中的风险为标准,采用基于犹豫直觉模糊语言集的TOPSIS方法进行不同方案的决策。最后,以磷酸在宜昌-衢州之间的运输为案例,对4种常用运输方案进行风险评估,以综合评价指数进行对比。结果表明,在先水路后铁路、先水路后公路、先公路后铁路、先铁路后公路4种方案中,从宜昌到衢州之间先公路后铁路的运输方式所得综合评价值最高,应选择方案3。     

剧毒化学品甲苯-2，4-二异氰酸酯运输危险性评估

为探讨低挥发性剧毒化学品甲苯-2，4-二异氰酸酯在运输过程中大量泄漏引起群体中毒事故的可能性以及对环境的影响，对本品的急性毒性、扩散模型、环境转归、生态毒性，以及运输泄漏事故资料进行综合分析和评估。评估结果本品吸人中毒的潜在危险性指数为低度危险物质；扩散模型运输泄漏模拟危险区域下风向距离小于某些非剧毒品；环境转归研究显示本品在环境介质中没有持久性，没有明显的生物蓄积性，生态毒性较低；历年来运输泄漏事故分析未见发生大规模严重群体中毒和环境污染事故。认为本品在运输过程中大量泄漏，不会大范围扩散引起严重群体中毒事故，也不会对环境造成严重和长期的危害，建议在运输环节中运输条件适当放宽，按照一般有毒品进行管理。     

甲黄隆,氯黄隆,苄嘧黄隆及其降解产物对蛋白核小球藻生长的效应

本文研究了甲黄隆、氯黄隆、苄嘧黄隆及其降解产物对蛋白核小球藻（Chlorellapyrenoidosa）的96h生长抑制急性毒性和化合物氮的生物可获得性。急性毒性试验表明:黄隆的毒性比其降解产物取代磺胺和氮杂环化合物大得多（EC_(50)相差2—3个数量级）,降解产物取代磺胺、均三嗪、取代嘧啶存在明显的低浓度促进生长现象,氮的生物可获得性试验表明:小球藻能有效利用低浓度取代磺胺、均三嗪、取代嘧啶化合物中的氮促进生长,促进程度:氯磺胺>苄磺胺≈二甲氧基嘧啶>甲磺胺>均三嗪。     

垃圾渗滤液水质特性研究进展

垃圾渗滤液已被公认为是高风险高污染废水,对地下水与地表水具有极大的潜在危害性。由于渗滤液具有高污染、水质水量差异大、难控等特点,使得其有效处理十分棘手。近年来国内外对渗滤液的研究十分广泛,本文结合国内外渗滤液相关研究中水质特性相关部分,从渗滤液的一般特性,溶解性有机质及危险物质等方面对渗滤液水质进行阐述,有助于深入了解渗滤液水质及其变化规律,从而为渗滤液的有效处理提供理论依据。     

Periphyton and Sediment Bioassessment in North Florida Bay

Periphyton colonization and sediment bioassessment were used ina survey to compare the relative environmental condition ofsampling sites located in Florida Bay and four peripheral sloughareas during the summer of 1995. Periphyton biomass, pigmentcontent, tissue quality and community composition weredetermined. In addition, benthic community composition and thetoxicities of whole sediments and associated pore waters weredetermined for two species of rooted macrophytes, an epibenthicinvertebrate and bioluminescent bacteria. Several locational differences were observed for the response parameters.Periphyton biomass was significantly greater in the Taylor Riverand the least in Shell Creek (P < 0.05). Most sediments were notacutely toxic to mysid shrimp nor phytotoxic. However, sedimentsfrom the Taylor River were more phytostimulatory than others (P< 0.05). Contaminant bioresidues were similar at most sites,however, mercury, chromium and nickel concentrations weregreater for periphyton colonized in the Taylor River and TroutCreek areas. Structural characteristics of the periphytic algalcommunity usually were statistically similar but a consistenttrend of lower density and diversity was evident for ShellCreek. The benthic community was the least diverse and dense inthe Canal C-111. The results of this study provide an initialindication of differences in the role of several slough areas aspossible sources of bioavailable contaminants to Florida Baywhich warrants additional investigation.     

苯并（a）芘和芘对梭鱼血红蛋白含量的影响

多环芳烃 [Ｐｏｌｙｃｙｃｌｉｃａｒｏｍａｔｉｃｈｙｄｒｏｃａｒｂｏｎｓ (ＰＡＨｓ) ]是海洋常见的污染物 ,由于具有致癌性和致突变性而成为必须检测的污染物 .有关多环芳烃对鱼类的血液学指标的影响 ,国外已有一些报道[1 ,2 ] ,国内的报道还很少 .有人认为白细胞数、白细胞的吞噬能力等免疫毒理学指标能较好地反映水体污染状况 .而血红蛋白能否作为污染监测的生物标志物 ,多环芳烃对鱼类血红蛋白是否存在毒性影响 ,这些尚无定论 .80年代以来 ,各国水生毒理学家越来越重视毒物的联合作用 ,已研究的毒物种类较广泛 ,包括金属间的联合作用…