192 resultados para Ecotoxicological
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A settlement inhibition assay using barnacle cyprid larvae, Balanus amphitrite, was developed with Cd2+ and phenol as standard reference toxicants. Mean percentage settlement of cyprid larvae showed a progressive reduction with increasing concentrations of Cd2+ and phenol. A significant reduction in settlement was found when cyprids were exposed to 0.1 mgL(-1) Cd2+ or 10 mgL(-1) phenol. The assay was used to assess the sublethal toxicity of three oil dispersants (Vecom B-1425 GL, Norchem OSD-570 and Corexit 9905) commonly used in Hong Kong waters. Results of this investigation show that the barnacle settlement inhibition assay can be incorporated into the battery of tests currently available for ecotoxicological assessment of marine contaminants. (C) 1997 Elsevier Science Ltd.
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The effects of sublethal concentrations of phenol and cadmium on the phototactic responses of the stage II nauplii of the barnacle Balanus amphitrite were investigated. Increased toxicant concentrations caused a reduction in phototactic responses. Balanus amphitrite nauplii exposed to nominal phenol concentrations of 100 ppm and higher for 1-12 h failed to exhibit phototactic responses, while longer exposure times of 24 and 48 h reduced the lowest observable effect concentration (LOECs) to 80 and 60 ppm, respectively. For cadmium, the LOECs, based on nominal concentrations, for B. amphitrite following 1, 6, 12, 24, and 48 h exposures were 20, 4.5, 4.0, 1, and 0.75 ppm, respectively. The LOECs can be significantly reduced by increasing the duration of exposure to the toxicants. A good relationship exists between the phototactic response and toxicant concentration as well as exposure time. Results of this study indicate that the toxicant-induced reduction in phototactic responses of barnacle larvae can be used in a sensitive, rapid screening test for ecotoxicological assessments. (C) 1997 by John Wiley & Sons, Inc.
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人工合成麝香作为一种新型污染物,其生态行为及生态效应已经越来越受到关注。城市土-水界面污染流是除农业面源污染以外第二大面源污染,其成分复杂,采用常规的理化监测方法很难对其生态安全性加以评价。本研究在水生生态毒理实验基础之上,利用城市标识污染物-重金属镉(Cd)、铅(Pb)、佳乐麝香(HHCB)和城市土壤模拟城市土-水界面污染流,并以斑马鱼、草鱼为对象,以超氧化物岐化酶(SOD),过氧化物酶(POD),过氧化氢酶(CAT),丙二醛(MDA),可溶性蛋白(SP)为生物标志物,对其急性和亚急性生态毒理过程进行模拟研究,并通过对联合毒性实验的开展,系统研究了Cd、Pb和HHCB的单一与联合毒性效应、机理和过程。主要结论如下: HHCB和Cd均为中等毒性污染物,Cd和HHCB对斑马鱼的96h-LC50值分别为30.33和4.45 mg/L;在HHCB和Cd的等毒性复合急性实验中,联合作用类型随暴露时间的延长从联合变为拮抗,HHCB是复合污染中的主要污染物。 对水体中总浓度0.95-15.16 mg/L 的Cd和0.14-2.22mg/L的HHCB7天急性毒性机理实验显示,暴露于单一Cd污染斑马鱼体内抗氧化酶活性升高,暴露4天后,其体内MDA含量升高;而在HHCB胁迫2-4天后抗氧化酶活性和MDA含量均降低;联合作用中Cd在暴露的前1-4天对抗氧化酶的变化起主要作用,而之后HHCB开始起主导作用;斑马鱼急性胁迫下,抗氧化系统的诱导是斑马鱼对Cd胁迫的最初反应之一,而对于受HHCB胁迫的斑马鱼,蛋白含量的降低相对于抗氧化系统来说是斑马鱼受到损害的更重要原因。 对水体中总浓度0.005-0.05mg/L的Cd、0.5-4mg/L的Pb和0.01-0.2mg/L的HHCB对草鱼不同器官的14天亚急性毒性机理研究显示:肝脏受污染物的毒性作用最为显著,体内生物标志物也最为敏感;在Cd和Pb胁迫下,肝脏和肾脏内抗氧化酶随浓度的升高被显著抑制,而HHCB对各器官SOD和CAT活性产生诱导作用; MDA在重金属胁迫下其含量变化均不明显,SP含量轻微降低,而在HHCB胁迫下却分别呈现显著的升高和降低的趋势,所以MDA和SP含量可以作为检测HHCB的生物标志物;复合作用下HHCB的加入能使草鱼各器官中抗氧化酶的活性有所升高, MDA含量显著大幅度升高,SP含量显著大幅度降低,HHCB和Cd表现出很强的协同作用,而且HHCB在复合污染中起主导作用。
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生态毒理试验集合了污染物的整体效应及化学品代谢物质产生的效应.它可提供土壤中所有污染物对土壤质量影响的全部信息.然而,现有生态毒理试验方法大多用于水生生态系统的生态毒性检验,对土壤污染的诊断需要建立新的生态毒理诊断方法.该文选择4类典型土壤(红壤、草甸棕壤、暗棕壤和栗钙土),以(小麦、白菜、萝卜、西红柿、大葱)为供试植物,进行了重金属(Cu、Zn、Pb、Cd)、有机氯、多环芳烃污染的植物种子发芽与根伸长抑制试验;植物早期生长试验研究;以草甸棕壤为供试土壤,进行了重金属(Cu、Zn、Pb、Cd)单一、复合污染条件下的蚯蚓(郝子爱胜)急性毒性实验;以草甸棕壤、污染土壤和生物修复土壤进行蚕豆根尖实验和土壤原生动物(纤毛虫)实验.
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土-水界面污染流污染物成分复杂,采用常规的理化监测方法,很难对其生态安全性加以评价。本研究在水生生态毒理实验基础之上,利用重金属Cd、Zn和有机农药甲胺磷(MAP)模拟流经受重金属和农药污染土壤的土-水界面污染流,并以草鱼(Ctenopharyngodon idellus)为刘"象,以SOD,PoD为生物标志物,对其生态毒理过程进行模拟研究,并应用广义联合效应理论,系统研究了Cd、Zn、MAP的单一与联合毒性效应、机理以及土一水界面污染流对Cd、Zn、MAP的单一与联合毒性效应的影响。主要结论如下:1.Cd、Zn、MAP联合作用与污染暴露的时间有关;2.在含cd、zn、MAP土一水界面污染流中,Cd、Zn、MAP三者之间在毒理过程中的交互作用关系具有方向性,可以用广义联合效应来解释;3.土一水界面污染流增大了毒理过程中对草鱼的胁迫强度;4.土一水界面污染流能改变Cd、Zn、MAP在毒理过程中联合作用的类型;5.土一水界面污染流的毒理过程中,总的联合效应更多的依赖各因子的浓度水平组合。
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
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Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências Farmacêuticas
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The DIESE program (Determination of relevant Indicators for Environmental monitoring: A Strategy for Europe) brought together seven French and British research teams, a private company and the agencies responsible for the management of water bodies of the two countries (ONEMA and the Environmental Agency) in a joint effort to document the ecotoxicological effects related to the presence of chemicals in the environment. To contribute to a better understanding and management of the environment, the program has expanded its efforts to (1) use existing knowledge, or new information acquired during the research program, to identify important biological problems affecting wildlife, (2) increase our understanding of toxicological mechanisms involved and thus be able to identify the causes of the identified dysfunctions and (3) to hone our expertise and vigilance systems in order to better monitor changes in the environment and make appropriate diagnoses. The first part of the program identified clear biological effects, and using biological tests representative of the mechanisms of action of compounds, identified the responsible compounds present in the environment. In connection with the feminization observed in many fish species in European streams, a search for estrogenic and anti-androgenic compounds was conducted. A new test identifying estrogenic compounds has been developed in roach and the ER-Calux test for anti-androgenic effects has been implemented. The results showed that, in addition to biocides such as triclosan and chlorophène, many aromatic hydrocarbon compounds are likely to disturb the physiology of living organisms by interacting with the androgen receptor. Six of these were identified in sediment extracts: benzanthrone, fluoranthene, 1,2- benzodiphenylene sulfide, benzo[a]pyrene, benz[a] anthracene, and 9-phenylcarbazole. The second part of the program aimed at documenting and understanding the mechanisms of action of chemicals leading to physiological changes. This work represents a particular challenge when dealing with molluscs, as knowledge about their physiology and endocrinology is still fragmentary. Thus, new technologies including metabolomic and transcriptomic analyses have been implemented in order to obtain a comprehensive picture of the effects on molluscs. Metabolomic research demonstrated that estrogenic compounds are able to alter the metabolism of eicosanoids and amines, while transcriptomic strategies identified genes whose expression is altered in intersex clams. Because these genes mainly appear as “male” genes, the results suggest that these profound physiological changes result from demasculinisation of male clams. Proteomic studies have also been carried out to elucidate the mechanisms of action of pollutants on fish physiology. These studies generally included a set of molecular marker measurements in an integrative and ecological perspective. The results showed that not only male fish physiology is altered but also female reproductive status is impaired. Moreover, it appeared that other alterations of the fish endocrine system, such as androgenic effects, are at work and that the immune system is also subject to chemical pressure including effects from environmental estrogens. Notably, the immune system, like the endocrine system, seems to show periods of particular sensitivity during development. Measurements on growth and on the general metabolism emphasize the importance of environmental conditions in the physiology of aquatic organisms and in particular the inter-site variability due to temperature,hypoxic conditions, and fish development strategies. They thus provide a unique perspective that allow us to better understand the context and consequences of natural conditions on the population. In a third part of the program, the research conducted had the objective of developing and testing a biomarker strategy to support the environmental management methodologies. Two lanes of specific studies have been followed. The first was to implement, over all or part of the study area, robust biomarkers to establish maps that highlight the water bodies at risk and provide information on sources of compounds and associated disturbances. The second part of the work aimed at exploring methodologies to take advantage of biomarker measurements and to integrate them in a very simple and clear index. Partial or comprehensive maps of the Channel area were produced to report the presence of mutagenic or anti-androgenic compounds in the sediments, intersex fish and clams, and imposex. These maps may remain to be completed and work will be necessary to confront this information in order to learn relevant lessons for management of the environment, a goal that the DIESE program has contributed to by providing some necessary and original information.
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The DIESE program (Determination of relevant Indicators for Environmental monitoring: A Strategy for Europe) brought together seven French and British research teams, a private company and the agencies responsible for the management of water bodies of the two countries (ONEMA and the Environmental Agency) in a joint effort to document the ecotoxicological effects related to the presence of chemicals in the environment. To contribute to a better understanding and management of the environment, the program has expanded its efforts to (1) use existing knowledge, or new information acquired during the research program, to identify important biological problems affecting the wildlife, (2) increase our understanding of toxicological mechanisms involved and thus be able to identify the causes of the identified dysfunctions and (3) to hone our expertise and vigilance system in order to better monitor changes in the environment and make appropriate diagnoses.
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The concentrations of a range of micro-organic compounds in the Humber rivers have been measured at weekly intervals over a period of 1 year. The compounds include the triazine herbicides (simazine, atrazine, propazine, desmetryn and prometryn), selected organophosphorus insecticides (fenitrothion, malathion and parathion), phenylurea (chlorotoluron, diuron, isoproturon and linuron) and phenoxyacid herbicides (2,4-D, MCPA, MCPB and mecoprop), phenol derivatives (phenol, 2-ethylphenol, 2-chlorophenol, 4-nitrophenol, 2-methylphenol, 4-ethylphenol and 2,4-dichlorophenol), organochlorine insecticides (HEOD, DDT, TDE, DDE, HCB, alpha-BHC and lindane), PCB's and some synthetic pyrethroid insecticides (cis/trans-permethrin, fenvalerate and cypermethrin). The results indicate the high frequency of occurrence of many compounds in the southern Humber rivers Aire, Calder, Trent and Don compared with the more occasional concentrations found in the upland rivers with catchments dominated by low intensity agriculture. The more water soluble herbicides, atrazine, simazine, isoproturon and diuron are detected frequently in the southern rivers with the highest concentrations and abundance in the rivers Aire, Calder and Trent. The most abundant phenolic compound is 2,4-dichlorophenol usually occurring at concentrations <1 mu g/l. The organochlorine insecticides and PCB's are generally at concentrations <0.01 mu g/l, cis/trans-permethrin are the only synthetic pyrethroids detected and these are found in the rivers Aire and Calder at about equal concentrations of between 0.01 and 0.11 mu g/l. The results of the occurrence of simazine and atrazine in the rivers Trent, Don and Aire illustrate peaks in concentration in the spring and then later in the year during the early autumn coinciding with the first major storm after the summer. In the rivers Trent and Don, the annual exports (March 1994-95) of atrazine are lower than for simazine whereas in the R. Calder the yield of atrazine is higher than for simazine suggesting differences in use in these catchments. The maximum triazine concentration observed, i.e. 8 mu g/l of atrazine in the R. Calder, could have inhibiting effects on the phytoplankton and algal growth, although because of the transient nature of the peaks, recovery is expected to be rapid. The only other compounds measured at concentrations likely to produce detrimental ecotoxicological effects are cis/trans permethrin in the rivers Aire and Calder. (C) 1997 Elsevier Science B.V.
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In April 1998, a holding lagoon containing pyrite ore processing waste rich in arsenic, failed and released 5-6 million m(3) of highly polluting sludge and acidic water. Over 2700 ha of the internationally important Doñana National and Natural Parks were contaminated. The area of Natural Park to sustain the greatest impact was known as the Entremuros. This paper presents 0-5 cm soil monitoring data from the Entremuros, from sampling campaigns 6 and 18 months after the disaster; as well as macrophyte root, rhizome and stem data from samples taken 18 months after the spill. Results show a clear, decreasing, north-south arsenic soil pollution trend, both 6 and 18 months after the spill, and suggest a small reduction in total soil arsenic levels occurred over time; although a significant increase in extractable arsenic is also noted. The two macrophytes (Typha dominguensis and Scirpus maritimus) studied herein are not accumulating arsenic in stem parts, however, accumulation of arsenic on iron plaque on the roots of these plants may be occurring. Further work is recommended in order to determine the ecotoxicological significance of this process in relation to the avian food-chains of Doñana, and elsewhere.
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The main aims of the present study, conducted in the framework of the MONIQUA-Egadi Scientific Project, were twofold: first, to make the first step in the development and validation of an ecotoxicological approach for the assessment of marine pollution in coastal environments on the basis of a set of biomarker responses in new sentinel species; and second, to obtain preliminary information on environmental quality in an Italian marine protected area, the Egadi Islands (Sicily). Several cytochrome P450-dependent mixed-function oxidase activities were measured in the following sentinel species: rainbow wrasse Coris julis, gastropod limpet Patella caerulea, and sea urchin Paracentrotus lividus. The results suggest that specimens from the Favignana Harbor may be exposed to P450 inducers, whereas most of the other sites seem to share similar environmental quality. The proposed approach has potential for assessment of environmental quality in marine protected areas.