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Veröffentlichung Sediment toxicity testing for prospective risk assessment ̶ a new framework and how to establish it(2013)There is a recognized need to design a new framework for sediment toxicity testing that meets current scientific standards and regulatory requirements, such as reliable assessment of toxicity, which prevents any harmful effects on biodiversity, a strong capability to predict population- and community-level effects, and applicability of the results to decision-making. We propose a new framework for prospective sediment toxicity testing, and suggest solutions to the key methodological challenges that hinder establishment of this framework (comparison of sensitivities, design of test batteries, consideration of different exposure routes, extrapolations to population and community levels, use of test results for decision-making). The proposed framework consists of the following three units: test-battery system, higher-tier testing systems and additional ecological modeling, and a decision support system. The key methodologies proposed to establish this framework are compound-tailored test-battery use approach, relative sensitivity distribution analysis, toxicity tests that combine bacteria and arthropods, micro- and mesocosms studies, population and community models, and model-driven decision support systems. The proposed framework, as well as the key methods mentioned above, has the potential to improve not only prospective toxicity testing for sediments, but also ecological risk assessment in general. Quelle: http://www.tandfonline.comVeröffentlichung Low dose effects and non-monotonic dose responses for endocrine active chemicals: Science to practice workshop: Workshop summary(2013)A workshop was held in Berlin September 12-14th 2012 to assess the state of the science of the data supporting
low dose effects and non-monotonic dose responses (´´low dose hypothesis) for chemicals with
endocrine activity (endocrine disrupting chemicals or EDCs). This workshop consisted of lectures to present
the current state of the science of EDC action and also the risk assessment process. These lectures
were followed by breakout sessions to integrate scientists from various backgrounds to discuss in an
open and unbiased manner the data supporting the ´´low dose hypothesis. While no consensus was
reached the robust discussions were helpful to inform both basic scientists and risk assessors on all
the issues. There were a number of important ideas developed to help continue the discussion and
improve communication over the next few years.
Quelle: 2013 The Authors. Published by Elsevier Ltd. All rights reserved.Veröffentlichung Bewertung von Transformationsprodukten bei der Trinkwasseraufbereitung(2014)Oxidative Transformationsprodukte von Spurenstoffen werden am Fallbeispiel PSM-Metaboliten auf ihr toxisches Potenzial untersucht. Im Labormaßstab werden Ozonung, Anreicherung und (gen)toxikologische Testung miteinander gekoppelt.
© Energie Wasser PraxisVeröffentlichung Determining the probability of cyanobacterial blooms: the application of Bayesian networks in multiple(2015)A Bayesian network model was developed to assess the combined influence of nutrient conditions and climate on the occurrence of cyanobacterial blooms within lakes of diverse hydrology and nutrient supply. Physicochemical, biological, and meteorological observations were collated from 20 lakes located at different latitudes and characterized by a range of sizes and trophic states. Using these data, we built a Bayesian network to (1) analyze the sensitivity of cyanobacterial bloom development to different environmental factors and (2) determine the probability that cyanobacterial blooms would occur. Blooms were classified in three categories of hazard (low, moderate, and high) based on cell abundances. The most important factors determining cyanobacterial bloom occurrence were water temperature, nutrient availability, and the ratio of mixing depth to euphotic depth. The probability of cyanobacterial blooms was evaluated under different combinations of total phosphorus and water temperature. The Bayesian network was then applied to quantify the probability of blooms under a future climate warming scenario. The probability of the "high hazardousŁ category of cyanobacterial blooms increased 5% in response to either an increase in water temperature of 0.8˚C (initial water temperature above 24˚C) or an increase in total phosphorus from 0.01 mg/L to 0.02 mg/L. Mesotrophic lakes were particularly vulnerable to warming. Reducing nutrient concentrations counteracts the increased cyanobacterial risk associated with higher temperatures.Quelle: http://www.esajournals.orgVeröffentlichung Aquatic toxicity of the macrolide antibiotic clarithromycin and its metabolites(2015)The human macrolide antibiotic clarithromycin is widespread in surface waters. Our study shows that its major metabolite 14-hydroxy(R)-clarithromycin is found in surface waters in comparable amounts. This metabolite is known to be pharmacologically active. Additionally, clarithromycin is partly metabolised to N-desmethyl-clarithromycin, whichhas no antimicrobial activity.
For clarithromycin, some ecotoxicological studies on aquatic organisms have been published. However, many of them are not conform with the scientific principles as given in the "Technical guidance for deriving environmental quality standardsŁ (TGD-EQS), because numerous studies were poorly documented and the methods did not contain analytical measurements confirming that the exposure concentrations were in the range of ş 20%of the nominal concentrations.
Ecotoxicological effects of clarithromycin and its two metabolites on the zebrafish Danio rerio (embryo test), the microcrustacean Daphnia magna, the aquatic monocotyledonous macrophyte Lemna minor, the freshwater green alga Desmodesmus subspicatus (Chlorophyta) and the cyanobacterium Anabaena flos-aquae were investigated in compliance with the TGD-EQS. Environmental risk assessment was performed using ErC10 values of Anabaena, the species most sensitive to clarithromycin and 14-hydroxy(R)-clarithromycin in our testing. Based oncomparable toxicity and similar concentrations of clarithromycin and its active metabolite 14-hydroxy(R)-clarithromycin in surface waters, an additional multiplication factor of 2 to the assessment factor of 10 on the ErC10 of clarithromycin should be used. Consequently, a freshwater quality standard of 0.130 ìg L-1 is proposed for clarithromycin as the "lead substanceŁ. Taking this additional multiplication factor of 2 into account, single monitoring of clarithromycin may be sufficient, in order to reduce the number of substances listed for routine monitoring programs.Quelle: http://www.sciencedirect.com/Veröffentlichung A weight-of-evidence approach to assess chemicals: case study on the assessment of persistence of 4,6-substituted phenolic benzotriazoles in the environment(2016) Becker, Eva; Brandt, Marc; Jöhncke, Ulrich; Sättler, Daniel; Schulte, ChristophBackground
One important purpose of the European REACH Regulation (EC No. 1907/2006) is to promote the use of alternative methods for assessment of hazards of substances in order to avoid animal testing. Experience with environmental hazard assessment under REACH shows that efficient alternative methods are needed in order to assess chemicals when standard test data are missing. One such assessment method is the weight-of-evidence (WoE) approach. In this study, the WoE approach was used to assess the persistence of certain phenolic benzotriazoles, a group of substances including also such of very high concern (SVHC).
Results
For phenolic benzotriazoles, assessment of the environmental persistence is challenging as standard information, i.e. simulation tests on biodegradation are not available. Thus, the WoE approach was used: overall information resulting from many sources was considered, and individual uncertainties of each source analysed separately. In a second step, all information was aggregated giving an overall picture of persistence to assess the degradability of the phenolic benzotriazoles under consideration although the reliability of individual sources was incomplete.
Conclusions
Overall, the evidence suggesting that phenolic benzotriazoles are very persistent in the environment is unambiguous. This was demonstrated by a WoE approach considering the prerequisites of REACH by combining several limited information sources. The combination enabled a clear overall assessment which can be reliably used for SVHC identification. Finally, it is recommended to include WoE approaches as an important tool in future environmental risk assessments.
Quelle: https://enveurope.springeropen.comVeröffentlichung From the exposome to mechanistic understanding of chemical-induced adverse effects(2017) Escher, Beate I.; Hackemüller, Jörg; Polte, Tobias; Eisenträger, Adolf; Walter-Rohde, SusanneThe exposome encompasses an individual's exposure to exogenous chemicals, as well as endogenous chemicals that are produced or altered in response to external stressors. While the exposome concept has been established for human health, its principles can be extended to include broader ecological issues. The assessment of exposure is tightly interlinked with hazard assessment. Here, we explore if mechanistic understanding of the causal links between exposure and adverse effects on human health and the environment can be improved by integrating the exposome approach with the adverse outcome pathway (AOP) concept that structures and organizes the sequence of biological events from an initial molecular interaction of a chemical with a biological target to an adverse outcome. Complementing exposome research with the AOP concept may facilitate a mechanistic understanding of stress-induced adverse effects, examine the relative contributions from various components of the exposome, determine the primary risk drivers in complex mixtures, and promote an integrative assessment of chemical risks for both human and environmental health. Quelle: VerlagsinformationVeröffentlichung A hierarchical testing strategy for micropollutants in drinking water regarding their potential endocrine-disrupting effects - health-related indicator values(2017) Grummt Tamara; Redelstein, Regine; Kuckelkorn, Jochen; Heide, Timon; Kunze, JenniferVeröffentlichung Evaluating the credibility of histopathology data in environmental endocrine toxicity studies(2017) Wolf, Jeffrey C.; Maack, Gerd