腐殖酸可降低纳米银的水生生物毒性

本文作者主要研究了腐殖酸对聚乙烯吡咯烷酮包覆的纳米银颗粒(polyvinylpyrrolidone-coated AgNPs)毒性的影响,受试生物涵盖了水生系统不同的营养级别,包括藻类(Raphidocelis subcapitata)、水蚤类(Chydorus sphaericus)以及淡水鱼类(Danio rerio)。结果显示,腐殖酸可降低AgNPs对本研究中所有水生生物的毒性,并具有明显的剂量效应关系。原因为：1）腐殖酸使AgNPs表面带有更多负电荷,这阻碍了AgNPs与藻细胞的接触,使毒性降低;2）腐殖酸抑制了AgNPs中Ag⁺的溶出,而本研究显示自由Ag⁺的毒性高于团聚的纳米银颗粒。
精选自Zhuang Wang, Joris T.K. Quik, Lan Song, Evert-Jan Van Den Brandhof, Marja Wouterse and Willie J.G.M. Peijnenburg. Humic substances alleviate the aquatic toxicity of polyvinylpyrrolidone-coated silver nanoparticles to organisms of different trophic levels. Environmental Toxicology and Chemistry: Volume 34, Issue 6, pages 1239–1245, June 2015. DOI: 10.1002/etc.2936
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2936/full
     

Cr(VI)对脊尾白虾(Exopalaemon carinicauda)幼虾暴露和恢复期肝胰脏的SOD活性、MDA及MTs含量的影响

为了探索水体中Cr(VI)对脊尾白虾(Exopalaemon carinicauda)的毒性效应,通过Cr(VI)的暴露(15 d)和清水恢复实验(15 d),研究了Cr(VI)对脊尾白虾肝胰脏的SOD活性、MDA及MTs含量的影响。结果表明,通过15 d的暴露,5 mg·L-1(高浓度)、0.5 mg·L-1(低浓度)实验组肝胰脏的SOD均显著高于对照组水平(p0.05),15 d的清水恢复后,两个浓度实验组均能够恢复到对照组水平(p0.05)。MDA在暴露阶段呈现持续上升的趋势,且在15 d后两个浓度实验组MDA的含量均显著高于对照组水平(p0.05),15 d的清水恢复后,5 mg·L-1实验组的MDA含量依然显著高于对照组水平(p0.05),0.5mg·L-1实验组的MDA含量基本恢复到对照组水平(p0.05)。通过15 d的暴露,两个浓度实验组MTs的含量均显著高于对照组水平(p0.05),15 d的清水恢复后,两个浓度实验组MTs的含量均能够恢复到对照组水平(p0.05)。     

Cr(Ⅵ)对脊尾白虾(Exopalaemon carinicauda)幼虾暴露和恢复期肝胰脏的SOD活性、MDA及MTs含量的影响

为了探索水体中Cr(Ⅵ)对脊尾白虾(Exopalaemon carinicauda)的毒性效应,通过Cr(Ⅵ)的暴露(15 d)和清水恢复实验(15d),研究了Cr(Ⅵ)对脊尾白虾肝胰脏的SOD活性、MDA及MTs含量的影响.结果表明,通过15 d的暴露,5 mg·L-1(高浓度)、0.5 mg· L-1(低浓度)实验组肝胰脏的SOD均显著高于对照组水平(p＜0.05),15 d的清水恢复后,两个浓度实验组均能够恢复到对照组水平(p＞0.05).MDA在暴露阶段呈现持续上升的趋势,且在15 d后两个浓度实验组MDA的含量均显著高于对照组水平(p＜0.05),15 d的清水恢复后,5mg·L-1实验组的MDA含量依然显著高于对照组水平(p＜0.05),0.5mg·L-1实验组的MDA含量基本恢复到对照组水平(p＞0.05).通过15 d的暴露,两个浓度实验组MTs的含量均显著高于对照组水平(p＜0.05),15 d的清水恢复后,两个浓度实验组MTs的含量均能够恢复到对照组水平(p＞0.05).     

Fluoride contamination in groundwater of central Rajasthan,India and its toxicity in rural habitants

This study was carried out to assess fluoride (Fl) concentration in groundwater in some villages of central Rajasthan, India, where groundwater is the main source of drinking water. Water samples collected from deep aquifer-based hand pumps were analyzed for Fl content. Fluoride in groundwater of 121 habitations of Bhilwara tehsil of Bhilwara district of Rajasthan was determined to examine the potential Fl-induced toxicity in rural locations. Fluoride concentrations in the tehsil ranged from 0.5 to 5.8 mg/l. In the tehsil, 69 villages (57%) were found to have Fl concentration beyond the maximum desirable limit recommended in Bureau of Indian Standards (BIS), 10500, 1991. Fifty-eight percent population of these villages was under the threat of fluorosis. One percent population of tehsil living in two villages ingested more than 5 mg/l Fl in each liter of drinking water and at maximal risk for dental and skeletal fluorosis. 142 individuals of these villages were examined for fluorosis. Data indicated that only four individuals (2.82%) did not exhibit dental fluorosis. Most individuals were found to suffer from mild (34.51% or 49 individuals) and moderate (31.69% or 45 individuals) fluorosis. Severe dental fluorosis was recorded in only 16 individuals (11.27%). In 104 individuals above 21 years of age examined for the prevalence of skeletal fluorosis, 66 were positive for skeletal fluorosis with a maximum 36.5% with grade I skeletal fluorosis. Grade II skeletal fluorosis was recorded in 28 individuals (26.9%). Data in this study demonstrate that there is a need to take ameliorative steps in this region to prevent fluorosis.     

A comparative study of the toxicity of lead and its impact on the carbohydrate metabolism and some haematological parameters of cichlid fish,oreochromis niloticus and catfish,clarius gariepinus from saudi arabia

Fresh and healthy specimens of Oreochromis niloticus (mean weight 70.5± 1.23 g and mean length, 12.3± 1.5cm) and Clarias gariepinus (mean weight, 41.8±2.3 g and mean length 13.78 ± 1.2 cm) were exposed to heavy metal lead, ranging in concentration from 10 to 18 mg L^‐1 for O. niloticus and 20 to 28 mg L^‐1 for C. gariepinus respectively. The 96 h LC₅₀ for both the species was computed as 12.45 mg L^‐1 (O. niloticus) and 22.65 mg L^‐1 (C. gariepinus). The cichlid fish was exposed to sublethal concentration of lead (2, 4 and 6 mgL^‐1) and catfish (4, 8 and 12 mgL^‐1). The erythrocytes count, haemoglobin concentration, haematocrit and the value of serum glucose increased significantly (P < 0.01), whereas leucocytes count, serum protein and serum triglyceride after intoxication declined in both the species with the same pattern but in different quantity. After 96 h of time a significant depletion of muscle and liver glycogen was noted, being greater in muscle (16.7% in O. niloticus) and in liver (15.9% in C. gariepinus). The response of fish to lead was dose dependent.     

典型氯酚类化合物对水生生物的毒性研究进展

氯酚类化合物(CPs)是一类广泛存在于水环境中的有机污染物。这类化合物具有环境稳定性、生物累积性和生物毒性,因而其在水环境中的生态毒理效应一直是人们关注的焦点。在水体中存在最普遍的酚类化合物主要有2,4-二氯酚(2,4-DCP),2,4,6-三氯酚(2,4,6-TCP)和五氯酚(PCP)。本文对近几年来这3种典型氯酚类化合物的水生态毒理学研究进行了总结,主要包括它们对水生生物的急性毒性、氧化损伤、发育毒性、内分泌干扰、遗传毒性、致癌性、免疫毒性、细胞毒性以及复合毒性的效应和机制,同时对目前存在的问题和进一步的研究方向进行了讨论和展望。     

邻苯二甲酸丁苄酯在肺匀浆中的体外代谢研究

了解邻苯二甲酸丁基苄酯(BBP)在肺匀浆中是否被代谢以及被代谢的情况,为更深入的肺脏毒性研究提供参考.于肺匀浆液中加入一定量BBP后,在0 min、10 min、20 min、40 min、60 min、80 min不同的温孵时间用乙酸乙酯灭活萃取剩余BBP,处理后用高效液相色谱测定BBP含量,再通过标准曲线计算出测定的BBP含量,得出BBP在肺中被降解的量,计算得到不同时间BBP在肺匀浆液中的降解百分率.研究结果表明,BBP在肺匀浆液中的线性范围为7.2～179 μmol/mL,平均萃取回收率为(97.11±0.98)%.BBP在肺匀浆液中被降解,与时间呈一定线性关系; 代谢上有雌雄差异,雌性在40 min以前降解比雄性快,在雌性肺匀浆中的降解半衰期为93.65 min,在雄性肺匀浆中的降解半衰期为70 min,但是雄性在整个过程中降解较快; 采用乙酸乙酯进行灭活萃取,在本实验条件下没有检测到代谢产物,说明代谢产物极性较大,没有被乙酸乙酯萃取出来.     

氯代酚和烷基酚类化合物对斑马鱼胚胎发育影响的研究

为研究氯代酚和烷基酚类化合物的毒性,采用斑马鱼胚胎发育技术,观察这两类化合物对不同发育阶段斑马鱼卵的影响.结果显示,在受精卵产出后立即染毒,胚胎对这些化合物最敏感的毒理学终点分别为: 五氯酚--48 h心律、色素和水肿的EC50值均为0.2 mg/L; 对-壬基酚--72 h孵化EC50为0.5 mg/L; 对-辛基酚--72 h畸形EC50为0.5 mg/L; 对-氯酚--48 h色素EC50为1.5 mg/L; 染毒时刻的不同对胚胎所造成的毒性效应也不同.几种氯代酚和烷基酚对发育24 h胚胎染毒,五氯酚毒性最大,对-辛基酚和对-壬基酚次之,对-氯酚毒性最小.研究表明,该类化合物对斑马鱼胚胎发育均有明显抑制作用,可以造成胚胎发育畸形甚至死亡,具有特定的最敏感毒理学终点.     

火灾烟气毒性的定量评价方法评述

火灾烟气毒性定量评价是毒理学研究的一个新兴领域.烟气毒性与建筑材料、燃烧条件、烟气毒物在建筑物内的传播规律及暴露时间有关,这些都是传统毒理学评价方法难以解决的问题.烟气毒性定量评价的目的是通过建立数学模型,以最少的动物试验,从宏观上更加定量化、系统化地评价和预测火灾烟气毒性.本文介绍了国外火灾烟气毒性定量评价的标准、烟气定量评价的数学模型,评述了这些模型的适用范围和优缺点,分析了火灾烟气毒性定量评价的发展方向.     

稻田土壤细菌对重金属镉的氧化应激反应研究

研究重金属镉胁迫下稻田土壤大肠杆菌K12、枯草芽孢杆菌B19及Ralstonia eutropha DKC1中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和ATP酶活性等应激酶活性的短期(46 h)变化.结果表明,不同浓度镉对E.coli K12,B.subtilisB19和R.eutrophaDKC1培养不同时间的SOD、CAT和ATP酶活性均有不同程度的诱导作用,表现在前期、低浓度时激活,后期、高浓度时抑制,体现了不同微生物间的差异以及抗镉潜力的不同.3种指标间接地反映了环境中有毒有害物质的存在,且能在早期较灵敏地指示污染的影响,作为环境受到污染胁迫的细胞生化指标具有一定可行性.