环丙沙星(CIP)对鲤鱼早期生长阶段的影响

我们依据经济合作与发展组织的210指导性文件,利用鲤鱼受精卵,进行环丙沙星(CIP)的毒性试验。测试浓度设置为1、100、500、1 000和3 000 μg?L^L-1。我们发现在所有测试组中,暴露于CIP会加速孵化,但在暴露于最高浓度CIP(3000 μg?L^L-1)的测试组,出现了显著的生长下降的现象。在实验的第6天(孵化之后),可以观察到大量增加的肉眼可见的形态异常现象。最高数量肉眼可见的形态异常现象是在自由胚胎和幼虫CIP暴露浓度为100、500、1 000和3 000 μg?L^L-1的测试组中产生的(测试样本的20%~23%)。在所有CIP暴露试验组中,均检测出GST活性的呈逐步降低趋势,但是在CIP浓度为500和3 000 μg?L^L-1的测试组中出现了显著差异(p < 0.01)。其中在大多数测试浓度下,谷胱甘肽过氧化物酶和过氧化氢酶的活性增加(p < 0.01,p < 0.05),而在CIP暴露浓度为500和3 000 μg?L^L-1的测试组,谷胱甘肽还原酶出现活性降低的现象(p < 0.05)。在所有的CIP暴露组中,硫代巴比妥酸活性物质的浓度明显降低(p < 0.01)。可测的CIP最低有效浓度(LOEC)是1 μg?L^L-1。\这些结果表明,孵化过程,早期的个体发育,形态异常的产生,以及鱼类体内的抗氧化和生物转化酶活性和脂质过氧化反应,都会受到CIP影响。
精选自Dana Zivna, Lucie Plhalova, Lucie Chromcova, Jana Blahova, Miroslav Prokes, Misa Skoric, Petr Marsalek, Eva Praskova, Stanislava Stepanova, Zdenka Svobodova. The effects of ciprofloxacin on early life stages of common carp (Cyprinus carpio). Environmental Toxicology and Chemistry: Volume 35, Issue 7, pages 1733–1740, July 2016. DOI: 10.1002/etc.3317
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3317/full
     

An ecotoxicological view on neurotoxicity assessment

The numbers of potential neurotoxicants in the environment are raising and pose a great risk for humans and the environment. Currently neurotoxicity assessment is mostly performed to predict and prevent harm to human populations. Despite all the efforts invested in the last years in developing novel in vitro or in silico test systems, in vivo tests with rodents are still the only accepted test for neurotoxicity risk assessment in Europe. Despite an increasing number of reports of species showing altered behaviour, neurotoxicity assessment for species in the environment is not required and therefore mostly not performed. Considering the increasing numbers of environmental contaminants with potential neurotoxic potential, eco-neurotoxicity should be also considered in risk assessment. In order to do so novel test systems are needed that can cope with species differences within ecosystems. In the field, online-biomonitoring systems using behavioural information could be used to detect neurotoxic effects and effect-directed analyses could be applied to identify the neurotoxicants causing the effect. Additionally, toxic pressure calculations in combination with mixture modelling could use environmental chemical monitoring data to predict adverse effects and prioritize pollutants for laboratory testing. Cheminformatics based on computational toxicological data from in vitro and in vivo studies could help to identify potential neurotoxicants. An array of in vitro assays covering different modes of action could be applied to screen compounds for neurotoxicity. The selection of in vitro assays could be guided by AOPs relevant for eco-neurotoxicity. In order to be able to perform risk assessment for eco-neurotoxicity, methods need to focus on the most sensitive species in an ecosystem. A test battery using species from different trophic levels might be the best approach. To implement eco-neurotoxicity assessment into European risk assessment, cheminformatics and in vitro screening tests could be used as first approach to identify eco-neurotoxic pollutants. In a second step, a small species test battery could be applied to assess the risks of ecosystems.     

Living with disasters: social capital for disaster governance

This paper explores how social networks and bonds within and across organisations shape disaster operations and strategies. Local government disaster training exercises serve as a window through which to view these relations, and ‘social capital’ is used as an analytic for making sense of the human relations at the core of disaster management operations. These elements help to expose and substantiate the often intangible relations that compose the culture that exists, and that is shaped by preparations for disasters. The study reveals how this social capital has been generated through personal interactions, which are shared among disaster managers across different organisations and across ‘levels’ within those organisations. Recognition of these ‘group resources’ has significant implications for disaster management in which conducive social relations have become paramount. The paper concludes that socio‐cultural relations, as well as a people‐centred approach to preparations, appear to be effective means of readying for, and ultimately responding to, disasters.     

Increased plant size in exotic populations: a common-garden test with 14 invasive species

The "evolution of increased competitive ability" (EICA) hypothesis predicts that exotic species will adapt to reduced herbivore pressure by losing costly defenses in favor of competitive ability. Previous studies often support the prediction that plants from exotic populations will be less well defended than plants from native populations. However, results are mixed with respect to the question of whether plants from exotic populations have become more competitive. In a common-garden experiment involving plants from two native and two exotic populations of 14 different invasive species, we tested whether exotic plants generally grow larger than conspecific native plants, and whether patterns of relative growth depend on the intensity of competition. We found a quite consistent pattern of larger exotic than native plants, but only in the absence of competition. These results suggest that invasive species may often evolve increased growth, and that increased growth may facilitate adaptation to noncompetitive environments.     

The health and visibility cost of air pollution: a comparison of estimation methods

Air pollution from motor vehicles, electricity-generating plants, industry, and other sources can harm human health, injure crops and forests, damage building materials, and impair visibility. Economists sometimes analyze the social cost of these impacts, in order to illuminate tradeoffs, compare alternatives, and promote efficient use of scarce resource. In this paper, we compare estimates of the health and visibility costs of air pollution derived from a meta-hedonic price analysis, with an estimate of health costs derived from a damage-function analysis and an estimate of the visibility cost derived from contingent valuation. We find that the meta-hedonic price analysis produces an estimate of the health cost that lies at the low end of the range of damage-function estimates. This is consistent with hypotheses that on the one hand, hedonic price analysis does not capture all of the health costs of air pollution (because individuals may not be fully informed about all of the health effects), and that on the other hand, the value of mortality used in the high-end damage function estimates is too high. The analysis of the visibility cost of air pollution derived from a meta-hedonic price analysis produces an estimate that is essentially identical to an independent estimate based on contingent valuation. This close agreement lends some credence to the estimates. We then apply the meta hedonic-price model to estimate the visibility cost per kilogram of motor vehicle emissions.     

The importance of the short-term leaching dynamics of wood preservatives

The potential environmental impacts from the use of treated timber in aquatic areas is under scrutiny as a result of environmental legislation and reports of the deleterious environmental effects around treated structures. In this study leaching experiments of up to 3 weeks duration were conducted on two species of chromated copper arsenate treated timber, dried for different periods of time. Increased drying time significantly reduced leaching of Cr and As. The addition of a synthetic humic acid increased leaching of Cu and As, but reduced leaching of Cr. Putative risk assessments conducted using short-term copper leaching data suggested protocol design may influence decisions made regarding the environmental acceptability of such preservatives.     

Two formulations of the industrial surfactant, Toximul, differentially reduce mouse weight gain and hepatic glycogen in vivo during early development: effects of exposure to Influenza B Virus

Previous studies demonstrated that young mice exposed chronically to industrial surfactant (IS) do not exhibit obvious adverse health effects, but do have persistently reduced body weights and compromised hepatic energy metabolism. The present study examined the time course of effects of two formulations of the Toximul (Tox) class of anionic/nonionic IS on body weights and liver glycogen (+/-virus) during early development. Results showed that effects differed in two commonly used strains of mice. In CFW mice, 12 days' exposure to Tox resulted in retardation of weight gain that was most obvious several days after exposure ceased. In this strain effects were greater with Tox 3409F than with Tox MP-A and appeared to be reversible except when the mice were treated with both Tox 3409F and FluB. Weights of the CD-1 mice were not affected by either Tox treatment alone, but were significantly reduced on postnatal day 20 when Tox exposure had been combined with FluB infection. Postnatal replenishment of hepatic glycogen stores during the first three weeks also occurred at different rates in CFW and CD-1 mice. The effects of Tox (+/-FluB) on glycogen also varied with mouse strain and Tox formulation. In CFW mice, exposure to either formulation resulted in significant (55-59%) reductions in glycogen, although reductions were not evident until nine days after Tox exposure stopped. By contrast, hepatic glycogen in CD-1 mice was reduced both during and after dermal exposure to Tox 3409F, whereas no effect was observed with Tox MP-A. Notably, the 3409F effect was reversible in the CD-1 mice, but reversal did not occur in mice also infected with FluB. Tox MP-A+FluB-treated mice exhibited only a transient glycogen reduction. These results illustrate the importance of mouse strain and formulation specificities in assessing biological effects of xenobiotic surfactants. As well, they emphasize that chronic IS exposure can induce changes in growth and energy substrate availability in young mice that may not be evident unless there is a precipitating cofactor such as a viral infection.