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  • 1.
    Eichbaum, Kathrin
    et al.
    Rheinisch-Westfälische Technische Hochschule, Aachen, Germany.
    Brinkmann, Markus
    Rheinisch-Westfälische Technische Hochschule, Aachen, Germany.
    Buchinger, Sebastian
    German Federal Institute of Hydrology (BfG), Koblenz, Germany.
    Hecker, Marcus
    University of Saskatchewan, Saskatoon, Canada.
    Engwall, Magnus
    Örebro University, School of Science and Technology.
    van Bavel, Bert
    Örebro University, School of Science and Technology.
    Reifferscheid, Georg
    German Federal Institute of Hydrology (BfG), Koblenz, Germany.
    Hollert, Henner
    Rheinisch-Westfälische Technische Hochschule, Aachen, Germany.
    The dioRAMA project: assessment of dioxin-like activity in sediments and fish (Rutilus rutilus) in support of the ecotoxicological characterization of sediments2013In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 13, no 4, p. 770-774Article in journal (Refereed)
    Abstract [en]

    Introduction: Given the complex interactions of re-suspension processes and bioavailability of sediment-bound pollutants such as dioxin-like chemicals, there is need for a better integrative understanding of the cause-effect relationship of these pollutants. Currently, the majority of studies investigating potential risks of these chemicals only focus on characterizing sediment extracts via in vitro bioassays, thereby disregarding bioavailability, uptake, metabolism, and elimination rates of these compounds in vivo. To determine to which extent mechanism-specific effects in vitro reflect possible adverse effects in vivo, the research project dioRAMA, involving partnership between the Institute for Environmental Research of RWTH Aachen University and the Department Biochemistry/Ecotoxicology of the German Federal Institute of Hydrology, was established.

    Methods: Animals from an elevated trophic level-common roach (Rutilus rutilus)-will be exposed to sediments from two major German rivers. Exposure will be performed in a system that enables a concurrent monitoring of environmental parameters. In parallel, in vitro studies will be conducted to determine dioxin-like potentials of sediment and fish extracts from the in vivo exposure experiments using different cell lines with varying endpoints. Moreover, extract fractionation procedures, using the strategy of effect-directed analysis, will enable the detection of specific contaminant groups responsible for the biological activity observed.

    Conclusion: A closer interconnection between applied ecotoxicological science and regulatory needs will facilitate the improved assessment of dioxin-like compounds in sediment and biota. Consequently, this will enable their application in sediment management programs, which is one of the main goals of the dioRAMA project.

  • 2.
    Hollert, Henner
    et al.
    University of Heidelberg.
    Keiter, Steffen
    University of Heidelberg.
    König, Natalie
    University of Heidelberg.
    Rudolf, Marc
    University of Heidelberg.
    Ulrich, Markus
    University of Heidelberg.
    Braunbeck, Thomas
    University of Heidelberg.
    A new sediment contact assay to assess particle-bound pollutants using zebrafish (Danio rerio) embryos2003In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 3, no 3, p. 197-207Article in journal (Refereed)
    Abstract [en]

    Goal, Scope and Background. Based on a bioassay battery coveringonly primary producers and consumers as well as degraders, the potential ecological hazard of sediments to vertebrates cannot be estimated comprehensively. Therefore, there is an urgent need to develop and standardize integrated vertebrate-based test systems for sediment investigation strategies. Whereas vertebrate-based in vitro systems have frequently been used for the investigation of aqueous samples, there is a significant lack of whole sediment assays. Thus, the purpose of the present study was: (1)to develop a rapid and reliable, but comprehensive method to investigate native sediments and particulate matters without preceding extraction procedures; (2) to compare the hazard potential of solid phase sediments to the effects of corresponding pore waters and organic extracts in order to characterize the bioavailability of the particle-bound pollutants; and (3) to relatively evaluate the embryotoxic effects of sediments from the catchment areas of the rivers Rhine, Neckar and Danube.

    Methods (or Main Features). To investigate the toxicity of sediment samples on vertebrates, the standard embryo toxicity test with the zebrafish (Danio rerio; Hamilton-Buchanan 1922) according to DIN 38415-6 was modified with respect to exposure scheme and toxicological endpoints. Sediments from the catchment area of the Neckar River were assessed using pore waters, acetonic extracts and native sediments in order to get inside into the potential bioavailability of particle-bound pollutants. A comprehensive test protocol for the investigation of native sediments in the embryo toxicity test with the zebrafish is presented.

    Results and Discussion. The fish embryo assay with Danio rerio can be carried out with both aqueous and organic sediment extracts as well as native (whole, solid phase) sediment samples. Elongation of exposure time from 48 to up to 196 h significantly increased the mortality. Using the fish egg assay with native sediments, a broad range of embryotoxic effects could be elucidated, including clear-cut dose-response curves for the embryotoxic effects of contaminated sediments; in contrast, absence ofembryotoxic effects could be demonstrated even for the highest test concentrations of unpolluted sediments. With native sediments, embryotoxicity was clearly higher than with corresponding pore waters, thus corroborating the view that – at least for fish eggs – the bioavailability of particle-bound lipophilic substances in native sediments is higher than generally assumed. The relative ranking of sediment toxicity was identical using both native sediments and sediment extracts, EC20 values of the latter, however, being eight time lower higher than with the native sediments. A comparison of the embryo toxic effects of samples from the Neckar area with locations along the Rhine and Danube rivers elucidated a broad range of results, thus indicating different levels of contamination.

    Conclusions. A modified protocol of the zebrafish embryo test allows the assessment of sediment toxicity in both aqueous extracts and native sediments. The isolated investigation of pore waters may result in a clear-cut underestimation of the bioavailability of lipophilic particle-bound substances (as determined by native sediments).

    Recommendations and Perspectives. The zebrafish embryo test with native (whole, solid phase) sediments appears very promising for the evaluation of the bioavailable fraction of lipophilicparticle-bound substances and can therefore be recommended for the evaluation of vertebrate toxicity in tiered sediment test strategies and dredging directives such as the HABAB-WSV. Whereas acetone extracts may be tested as a rough estimation of embryotoxicity, native sediment samples will provide a more comprehensive and realistic insight into the bioavailable hazard potential

  • 3.
    Keiter, Steffen
    et al.
    Department of Zoology, Aquatic Ecology and Toxicology Section, University of Heidelberg, Heidelberg, Germany.
    Braunbeck, Thomas
    Department of Zoology, Aquatic Ecology and Toxicology Section, University of Heidelberg, Heidelberg, Germany.
    Heise, Susanne
    Institut für Biogefahrenstoffe und Umwelttoxikologie, Hamburg University of Applied Sciences, Hamburg, Germany.
    Pudenz, Stefan
    Westlakes Scientific Consulting Ltd, Department of Environmental Science, Cumbria, UK.
    Manz, Werner
    German Federal Institute of Hydrology, Koblenz, Germany.
    Hollert, Henner
    Department of Zoology, Aquatic Ecology and Toxicology Section, University of Heidelberg, Heidelberg, Germany; Department of Ecosystem Analysis, RWTH Aachen University, Aachen, Germany.
    A fuzzy logic-classification of sediments based on data from in vitro biotests2009In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 9, no 3, p. 168-179Article in journal (Refereed)
    Abstract [en]

    Background, aim, and scope: Ecotoxicological risk assessment of sediments is usually based on a multitude of data obtained from tests with different endpoints. In the present study, a fuzzy logic-based model was developed in order to reduce the complexity of these data sets and to classify sediments on the basis of results from a battery of in vitro biotests.

    Materials and methods: The membership functions were adapted to fit the specific sensitivity and variability of each biotest. For this end, data sets were categorized into three toxicity levels using the box plot and empirical methods. The variability of each biotest was determined to calculatethe range of the gradual membership. In addition, the biotests selected were ranked according to the biological organisation level in order to consider the ecological relevance of the endpoints measured by selected over- or underestimation of the toxicity levels. In the next step of the fuzzy logic model, a rule-base was implemented using if...and...then decisions to arrive at a system of five quality classes.

    Results: The results of the classification of sediments fromthe Rhine and Danube Rivers showed the highest correlation between the biotest results and the fuzzy logical ternative based on the empirical method (i.e. the classification of the data sets into toxicity levels).

    Discussion: Many different classification systems based on biological test systems are depending on respective datasets; therefore, they are difficult to compare with other locations. Furthermore, they don‘t consider the inherent variability of biotests and the ecological relevance of these test systems as well. In order to create a comprehensive risk assessment for sediments, mathematical models should be used which take uncertainties of biotest systems into account, since they are of particular importance for areliable assessment. In the present investigation, the variability and ecological relevance of biotests were incorporated into a classification system based on fuzzy logic. Furthermore, since data from different sites and investigations were used to create membership functions ofthe fuzzy logic, this classification system has the potential to be independent of locations.

    Conclusions: In conclusion, the present fuzzy logic classification model provides an opportunity to integrate expert knowledge as well as acute and mechanism-specific effects for the classification of sediments for an ecotoxicological risk assessment.

    Recommendations and perspectives: In order to achieve amore comprehensive classification, further investigation is needed to incorporate results of chemical analyses and in situ parameters. Furthermore, more discussions are necessary with respect to the relative weight attributed to different ecological and chemical parameters in order too btain a more precise assessment of sediments.

  • 4.
    Keiter, Steffen
    et al.
    Institute for Environmental Research (Biology V), Department of Ecosystem Analysis, RWTH Aachen University, Aachen, Germany.
    Peddinghaus, Sabrina
    Institute for Environmental Research (Biology V), Department of Ecosystem Analysis, RWTH Aachen University, Aachen, Germany.
    Feiler, Ute
    German Federal Institute for Hydrology (BfG), Koblenz, Germany.
    von der Goltz, Britta
    Aquatic Ecology and Toxicology Group, Department of Zoology, University of Heidelberg, Heidelberg, Germany.
    Hafner, Christoph
    Hydrotox GmbH, Freiburg, Germany.
    Ho, Nga Yu
    Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.
    Rastegar, Sepand
    Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.
    Otte, Jens
    Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen, Germany.
    Ottermanns, Richard
    Research Institute GAIAC, Aachen, Germany.
    Reifferscheid, Georg
    German Federal Institute for Hydrology (BfG), Koblenz, Germany.
    Strähle, Uwe
    Karlsruhe Institute of Technology (KIT), Institute of Toxicology and Genetics (ITG), Eggenstein-Leopoldshafen, Germany.
    Braunbeck, Thomas
    Aquatic Ecology and Toxicology Group, Department of Zoology, University of Heidelberg, Heidelberg, Germany.
    Hammers-Wirtz, Monika
    Research Institute GAIAC, Aachen, Germany.
    Hollert, Henner
    Institute for Environmental Research (Biology V), Department of Ecosystem Analysis, RWTH Aachen University, Aachen, Germany.
    DanTox-a novel joint research project using zebrafish (Danio rerio) to identify specific toxicity and molecular modes of action of sediment-bound pollutants2010In: Journal of Soils and Sediments, ISSN 1439-0108, E-ISSN 1614-7480, Vol. 10, no 4, p. 714-717Article in journal (Refereed)
    Abstract [en]

    Introduction: The European Water Framework Directive aimsto achieve a good ecological and chemical status in surface water of European rivers by the year 2015. Since sediments and particulate matter act as secondary sources for pollutants, applied sediment toxicology is perceived to play a major rolefor obtaining new knowledge that can contribute to successful attainment of the goal. However, the existing bioassays for sediment toxicity analyses do not provide sufficient data concerning bioavailability of environmental pollutants. In this regard, there is an urgent need to combine sediment contact assays with gene expression analysis to investigate mechanism-specific sediment toxicity.

    Purpose: The aim of the novel joint research project is todevelop a eukaryotic test system, which can be used to investigate the ecotoxicological effects of contaminated sediments on gene expression level (DNA-array and RT-PCR).Current ecotoxicological research customarily involves a battery of bioassays to cover different toxicological endpoints (e.g., teratogenicity, genotoxicity, mutagenicity, Ah-receptor mediated toxicity, neurotoxicity). In contrast, methods that detect alterations in gene expression offer deeper insight by elucidating how chemical exposure and/or environmental challenge affect multiple metabolic pathways leading to these particular kinds of toxic response. Gene expression profiles reflect the way cells and organisms adapt or respond to a changing environment.

    Conclusion: The present project aspires to increase the fundamental molecular and physiological knowledge concerning the mode of action of environmental toxicants in zebrafish (Danio rerio). By working with partners from the academic and research institutions as well as from industry and waterway regulations, the success of this basic research-driven joint project in terms of development and implementation of novel sediment toxicity methods will be realized.

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