The 2015 Annual Meeting of SETAC German Language Branch in Zurich (7–10 September, 2015): Ecotoxicology and environmental chemistry—from research to application

This report provides a brief review of the 20th annual meeting of the German Language Branch of the Society of Environmental Toxicology and Chemistry (SETAC GLB) held from September 7th to 10th 2015 at ETH (Swiss Technical University) in Zurich, Switzerland. The event was chaired by Inge Werner, Director of the Swiss Centre for Applied Ecotoxicology (Ecotox Centre) Eawag-EPFL, and organized by a team from Ecotox Centre, Eawag, Federal Office of the Environment, Federal Office of Agriculture, and Mesocosm GmbH (Germany). Over 200 delegates from academia, public agencies and private industry of Germany, Switzerland and Austria attended and discussed the current state of science and its application presented in 75 talks and 83 posters. In addition, three invited keynote speakers provided new insights into scientific knowledge ‘brokering’, and—as it was the International Year of Soil—the important role of healthy soil ecosystems. Awards were presented to young scientists for best oral and poster presentations, and for best 2014 master and doctoral theses. Program and abstracts of the meeting (mostly in German) are provided as Additional file 1. Electronic supplementary material The online version of this article (doi:10.1186/s12302-016-0088-3) contains supplementary material, which is available to authorized users.

Achtung: Der Besuch des Erdbebensimulators erfolgt auf eigene Gefahr. Für Kleinkinder bis zum 5. Geburtstag, Personen mit Rücken-oder Nackenproblemen oder anderweitigen Ge-15 brechen sowie Hochschwangere ist der Besuch des Simulators nicht geeignet. Kinder zwischen 5 und 11 Jahren dürfen den Simulator nur in Begleitung besuchen. insufficient to develop Sustainable Chemistry only on regional health and the environment occur at a global scale -and often use patterns of materials and energy are unsustainable and increasing consumption of goods is leading to more waste These issues will be discussed in a high-level panel in Approach to the International Chemicals Management.
presented and discussed with international experts and decision barriers and needs. Discussions will be stirred by panel addressing emerging topics in sustainable chemicals management //www.umweltbundesamt.de/en/topics/chemicals/chemicalschemistry-conference-2015-start.

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As one of the leading CROs, we support our customers in the complex process of contract research. Integrity, trustworthiness and reliability as well as our focus on quality and the customer are the trademarks of our operation. Prof. Dr. Hering's research interests include the biogeochemical cycling of trace elements in natural waters, water treatment technologies for the removal of inorganic contaminants from drinking water, and the management of water resources and water infrastructure. Her research includes both laboratory and field experimental studies. She has been a member of the faculty of the California Institute of Technology and of the University of California, Los Angeles. She is a past recipient of the U.S. National Science Foundation's Young Investigator Award and Presidential Faculty Fellows Award. She has served as an Associate Editor for the journal Environmental Science & Technology and is currently a member of the Board of Reviewing Editors for Science.

Prof. Dr. Emmanuel Frossard
Emmanuel Frossard got his degree of "ingénieur agronome" (MSc in agricultural sciences) and his PhD in agricultural sciences from the Ecole Nationale Supérieure d'Agronomie et des Sciences Alimentaires (ENSAIA) in Nancy (France). He was a postdoctoral fellow at the Saskatchewan Institute of Pedology in Saskatoon, Canada for 2 years. In 1988, he became a senior scientist in soil science at the ENSAIA. In 1994, he was elected associate professor of Plant Nutrition in the Institute of Plant Sciences and the Department of Agricultural and Food Sciences of the ETH Zurich where he became full professor in 2000. Following some restructurations he is now Professor and in the Institute of Agricultural Sciences of the Department of Environmental Systems Science at ETH Zurich.
His work focuses on nutrient cycling in cropping and grassland systems. Together with his Group, he conducts process-oriented research at levels ranging from the molecule to the field, to understand drivers controlling nutrient fluxes and to propose integrated nutrient management schemes that will contribute to the development of ecologically efficient agricultural systems both in temperate and tropical environments. He is currently president of the steering committee of the Swiss national research program on soil as a resource (NRP 68 Soils deliver a wide range of ecosystem services to society (food and fiber production, nutrient cycling, regulation of water flow and quality, pest regulation, carbon sequestration and cycling…). However, soils are threatened by many dangers (erosion, soil organic and biodiversity loss, compaction, sealing, nutrient mining, salinity, contamination) that affect the ability of soils to deliver these services. The concept of soil health has been developed to tackle soil degradation and to maintain/improve productivity; soil health is hence a practiceoriented concept. However, soil health has been variably defined in the literature. For Gugino et al. (2009) soil health is turned towards agriculture as it "deals with the integration of the physical, chemical and biological properties of soil for improved productivity and environmental quality". Kibblewhite et al. (2008) define a healthy soil in a broader manner, as a soil "that is capable of supporting the production of food and fiber, to a level and with a quality sufficient to meet human requirements, together with continued delivery of other ecosystem services that are essential for maintenance of the quality of life for humans and the conservation of biodiversity". Soil health assessment requests an appropriate toolbox that can be used in the field. This concept is now used in the tropics, e.g. to map African soils (Shepherd et al., 2015), in North America for the management of agricultural soils (Gugino et al., 2009) and to assess the state of soils in Europe (Kibbelwhite et al., 2008). This presentation will first recall some important soil properties and it will discuss the ecosystem services delivered by soils. It will then show how the concept of soil health can be used to evaluate the state of agricultural soils. Finally specific examples will show how management practices affect soil health and how it can be recovered, however often at the price of trade-offs. Sediment management needs tools for quality assessment that help to prioritize management or further assessment options. Especially the quality assessment of fine sediments is an important issue because they are a major binding phase for many pollutants inside waterbodies. Besides being able to release pollutants to the water phase again, fine sediments are directly impacting benthic organisms living between the fine particles. These benthic organisms comprise an abundant and diverse community that fulfils important functions in the aquatic ecosystem, such as regarding the nutrient cycle. Moreover, this community is mainly dominated by meiobenthic organisms (e.g., nematodes, tardigrades, ostracods, gastrotrichs, rotifers) and not by macroinvertebrates. Hence, tools based on nematodes have been recently developed to particularly assess the quality of fine sediments: a) nematodebased Sediment Quality Guidelines (SQG) for estimating the probability of toxic effects based on measured chemical concentrations and b) the NemaSPEAR-Index (Nematode SPEcies At Risk) that indicates pollution-induced nematode community alterations (Höss et al., 2011, Environ Int 37: 940-949). The presentation gives information about the derivation of the SQG, including the evaluation of their predictive ability. A major application of the SQG will likely be their use as a screening tool, but they can also be used for a chemical line of evidence in a weight-of-evidence framework. An example for the latter, using the NemaSPEAR for an ecological line of evidence, will be also given in the presentation. Nematode-based lines of evidence will likely facilitate the assessment of fine sediments and thus, support decision making processes of regulators. Moreover, both tools are generally also aiming at closing the knowledge gap regarding effects of pollutants on meiobenthic organisms, which are of high ecological relevance not only in fine freshwater sediments but also in many other habitats (e.g., periphyton, marine sediments, and soils). The impact of environmental contaminants on the behaviour of aquatic organisms is of increasing concern. Zebrafish, a well-established model species in toxicology, is also an emerging model in behavioural sciences. Behavioural alterations in zebrafish can indicate organism-level responses to compounds with different modes-of-action, in correlation with chemical classes. However, the procedures applied to evaluate behavioural changes in zebrafish early life stages (ELS) are not clearly defined and vary between laboratories and studies. That makes the interpretation and validation of results challenging. The standardization of experimental protocols and data analysis would promote the assessment of behavioural endpoints in zebrafish ELS.

Entwicklung und Anwendung von Sedimentkontakttests zur Untersuchung des bioverfügbaren Schädigungspotentials in Zebrabärblings-(Danio rerio) Embryonen
This study aimed to: (i) investigate candidate positive control chemicals for short light-dark transition behavioural testing with 5dpf zebrafish larvae; and (ii) evaluate if experiments conducted in two laboratories would produce comparable results. The same set of experiments was performed at the VU University and at RWTH Aachen University. At VU, the ViewPoint automated video tracking system was used; while at RWTH a custom-made system combined with EthoVision (Noldus) was applied. Zebrafish larvae were exposed for 10, 40 or 90min to several concentrations of ethanol, caffeine and nicotine, or control conditions. Larvae were submitted to short lightdark transitions, and video tracking of locomotion was performed. Data was analysed for parameters as total distance moved and ratios between dark and light activities. Stimulated or suppressed behavioural profiles were evaluated concerning test concentrations and exposure periods.
Basal locomotion activity in control conditions differed slightly between laboratories, which can be related to the use of different fish strains. Still, patterns of behavioural responses presented intra and inter-laboratory reproducibility for the same compounds, concentrations and exposure periods. Particularly, ethanol caused highly reproducible behavioural effects. Our study indicates that results of the two laboratories were consistent for the assessment of behavioural endpoints in zebrafish larvae exposed to the test compounds. Further investigations of neuroactive and neurotoxic chemicals are needed for the establishment and interpretation of new behavioural endpoints and standardized test protocols with zebrafish ELS. As a result, the applicability of zebrafish behavioural tests for the evaluation of complex environmental samples will be facilitated. Most freshwater mussel species of the Unionoida are endangered, presenting a conservation issue as they are keystone species providing essential services for aquatic ecosystems. As filter feeders with limited mobility, mussels are highly susceptible to water pollution. Despite their exposure risk, mussels are underrepresented in standard ecotoxicological methods. Our study aimed to demonstrate that mussel behavioral response to a chemical stressor is a suitable biomarker for the advancement of ecotoxicology methods that aids mussel conservation. Modern software and Hall sensor technology enabled mussel filtration behavior to be monitored real-time at very high resolution. With this technology, we present our method using Anodonta anatina and record their response to de-icing salt pollution. The experiment involved an environmentally relevant 'pulse-exposure' design simulating three subsequent inflow events. Three sublethal endpoints were investigated, Filtration Activity, Transition Frequency (number of changes from opened to closed, or vice versa) and Avoidance Behavior. The mussels presented a high variation in filtration behavior, behaving asynchronously. At environmentally relevant de-icing salt exposure scenarios, A. anatina behavior patterns were significantly affected. Treated mussels' Filtration Activity decreased during periods of very high and long de-icing salt exposure (p < 0.001), however, increased during short de-icing salt exposure. Treated mussels' Transition Frequency increased during periods of very high and long de-icing salt exposure (p < 0.001), which mirrored the Avoidance Behavior endpoint observed only by mussels under chemical stress. Characteristics of Avoidance Behavior were tighter shell closures with repeated and irregular shell movements which was significantly different to their undisturbed resting behavior (p < 0.001). Additionally, we found that mussels were sensitive to a chemical stressor even when the mussel's valves were closed. Our experimental method demonstrated that, with the application of current technologies, mussel behavioral response to a chemical stressor can be measured. The tested sublethal endpoints are suitable for mussel ecotoxicology studies. Avoidance Behavior proved to be a potentially suitable endpoint for mussel behavior effect concentration calculations. Therefore we recommend adult mussel behavior as a suitable biomarker for future ecotoxicological research.

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Abstracts-Vorträge 15. AquaHab®, a closed aquatic multispecies system for ecotoxicological purposes -past, present and future activities Dünne Matthias, OHB System AG matthias.duenne@ohb.de AquaHab® is a small closed aquatic multispecies system on laboratory level, containing different trophic levels -represented by Oryzias latipes (medaka fish), Hyalella azteca (mexican amphipod), Biomphalaria glabrata (snail of Planorbidae family), Ceratophyllum demersum (hornweed) as well as by nitrifying and denitrifying bacteria. They serve for a comprehensive exposure as well as effect assessment of chemicals. Effect endpoints from subcellular up to system level can be measured. A technical unit controls the test conditions in the 8,2 L-water tank (temperature, oxygen concentration, illumination). The closure of the system enables the assessment of the respiratory and photosynthetic activity as well as high reproducible test results. AquaHab® represents a bridge between single species tests and outdoor ponds concerning the relevance of the results for the environment, the effort to be done as well as the reproducibility of the test results.
In its present form, AquaHab® is highly suited for the risk assessment of chemicals during their development process. It is available for research projects as well as for industrial purposes. E.g., currently the long-term effect and the bioaccumulation of nanoparticles is assessed in AquaHab® in the framework of the BMBF funded project "DENANA" (Designkriterien für nachhaltige Nanomaterialien). However, AquaHab® might be used also for further activities, e. g. to "biomonitor" effluents from chemical parks or to investigate the risk of microplastic in aquatic systems.
An overview about past, present and future activities of this versatile tool for ecotoxicological purposes will be given at the symposium.

Fischer Stephan, Eawag
Ksenia Groh, Inge Werner and Kristin Schirmer stephan.fischer@eawag.ch Most of the tests developed for detection of chemical effects in organisms exposed in the environment are applicable to only a few model species. mRNA expression analysis of selected biomarker genes is a promising approach for field monitoring of non-model organisms because it can capture a wide spectrum of responses of organisms to chemical exposure. We established a biomarker gene set for brown trout (Salmo trutta) to assess the effects of micropollutants released by wastewater effluents. The biomarker set consisted of 20 genes which reflect different cellular stress responses like general stress, oxidative stress or biotransformation. The transcriptional regulation of these genes was measured in liver and kidney tissue samples of wild brown trout caught downstream and upstream of a wastewater treatment plant (WWTP) and from a reference river. Results from two seasonally different sampling campaigns showed that mRNA levels are site dependent. Fish taken downstream generally express a different transcriptional regulation pattern compared to fish from the upstream and a reference site, indicating that fish downstream are exposed to a higher level of environmental stressors. For example, the metal (Metallothionein B), endocrine disruption (Vitellogenin) or biotransformation (Cyp3a) sensitive genes were found to be significantly upregulated in fish from the downstream location compared to the other two sites. Results implicated a higher content of metals, potential estrogen-mimics or different pharmaceuticals downstream of the WWTP. Indeed, chemical analysis confirmed high concentrations of such compounds in the water from this site compared to the others. Our data demonstrates that quantifying expression levels of selected biomarker genes allows an assessment of exposure and related effects of chemicals. It appears that our method is a promising screening assay for assessing surface water quality. Moreover, based on the selected set of genes, predicting potential adverse effects may be possible. In mammals, an immunomodulating effect of thyroid hormones (TH) and thyroid disruptors is well documented. In fish, research on thyroid disruptors has been focused largely on adverse impacts on the development and functioning of the thyroid gland, whereas peripheral effects including the alteration of immunocapacity have been rarely studied. Here, we examine potential immunomodulating effects of thyroid-active compounds in rainbow trout. In an initial study, we demonstrated that immune cells of trout possess thyroid hormone receptors (THR) and thus are potentially responsive to THR agonists and antagonists. In addition, treatment of trout with either the active hormone, 5-triiodo-L-thyronine (T3), or the antagonist, 6-propyl-2-thiouracil (PTU), altered THR expression levels in the immune cells. These observations point to a possible impact of thyroid-.active compounds on the immune function of trout. To shed more light on this question, we used a custom-designed 60-mer oligo immune-targeted microarray to analyze the gene expression profiles induced by T3 or PTU in the head kidney of rainbow trout. Morphometric analyses of rainbow trout thyroid tissue revealed that PTU exposure increased the size of the epithelial cells, whereas T3 treatment induced no significant change. T3 and PTU had numerous differential effects on immune gene transcript profiles. The most prominent T3/PTU-induced differential gene expressions were observed for the Mitogen Associated Protein Kinases (MAPK), NFkB, Natural Killer (NK) and Toll-Like Receptor (TLR) pathways, including multipath genes (MPG) such as pleiotropic transcription factors (atf1, junb, myc), important pro-inflammatory genes (tnfa, tnf6, il1b) and interferon-related genes (ifng, irf10). From these findings, genes were identified which may serve as novel markers for T3/PTU exposure and/or to detect otherwise missed potentially immunodisrupting effects of endocrine-active environmental compounds.

Quesada-Garcia Alba, Instituto Nacional Investigaciones Agrarias y Alimentarias INIA, Madrid
In conclusion, the findings from this study promote our understanding of immunmodulating actions of T3 and PTU on fish.

Beauvais-Flueck Rebecca, University of Geneva
Mercury (Hg) is amongst the most toxic metals with no known biological function. Its properties: volatile, long-range transportable and biomagnified in the aquatic trophic chain have led Hg to become a global environmental issue, irrespective of the presence of local emission sources. Aquatic primary producers, such as phytoplankton and macrophytes, are key players of the biogeochemical cycle of mercury (Hg) in the aquatic environment. Indeed, the Hg bioaccumulation step from water to primary producers has been shown to be the largest increase of Hg concentrations in aquatic ecosystems reaching 104-fold and greater. It is therefore of the upmost importance to understand uptake and effects of Hg in primary producers. The effects of Hg on aquatic primary producers were only sparsely investigated until now. While it has been shown that Hg affects photosynthesis and the activity of oxidative stress enzymes in microalgae, its effects were less studied in macrophytes, especially concerning MeHg. Moreover most studies were conducted at high concentrations only and were thus not representative of environmental conditions. Using a transcriptomic approach (RNA-Seq), we therefore studied the effects at the molecular level of MeHg (5 x10 -11 , 5 x10 -10 , 5 x10 -9 and 5 x10 -8 M), in the microalga Chlamydomonas reinhardtii and the macrophyte Elodea nuttallii, adapting bioinformatics analyses to the available genomic information for the studied species. Strong response of the transcripts involved in photosynthesis was observed at all MeHg concentrations in the alga, but only at the two highest concentrations in the macrophyte. Concomitantly, MeHg affected genes involved in carbohydrates, amino acids and lipids metabolisms, as well as the expression of many transcripts coding for transporters. In fact, while ABC and calcium transporters were significantly affected by MeHg in C. reinhardtii, ATPases and ammonium transport were disregulated in E. nuttallii. Finally, metal transporters, e.g. zinc transporters, were significantly affected in both species. The transcriptome response to MeHg in the two representative aquatic primary producers was congruent with their morphological, physiological and sensitivity differences.

Characterization of transcriptional responses to dioxins and dioxinlike contaminants in roach (Rutilus rutilus) using whole transcriptome analysis
Koglin Sven, RWTH Aachen University Riverine sediments can be contaminated with a complex mixture of lipophilic organic pollutants. Of particular concern in this context are dioxins and dioxin-like compounds (DLCs), including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and some polycyclic aromatic hydrocarbons (PAHs). While many researchers have focused on investigating the molecular and biochemical effects of DLCs in a few standard model fish species, there is significant uncertainty with regard of the representativity of these model species for fishes native to riverine systems in Europe. In this study, the transcriptional changes in juvenile roach (Rutilus rutilus), a fish species that constitutes a large proportion of the fish biomass in bodies of freshwater throughout Europe, following treatment with equipotent concentrations of TCDD, PCB 156 or the dioxin-like PAH benzo[k]fluoranthene (BkF) were investigated. To this end, Illumina RNAseq was used to gain a comprehensive understanding of the potential molecular mechanisms and pathways of toxicity of different DLCs to this non-model species. Whole transcriptome analysis by use of ClueGO software revealed that DLCs have the potential to disrupt a number of important physiological processes, including energy metabolism, oogenesis, the immune system, apoptosis and the response to oxidative stress. However, despite use of equipotent concentrations of DLCs, there was only little conservation of transcriptional responses to each compound. TCDD provoked significant changes to abundances of transcripts of genes related to immunotoxicity and carbohydrate metabolism whereas PCB 156 caused no specific effects compared with the other two compounds. The most diverse suite of differentially expressed transcripts was caused by exposure to BkF, and included alterations to abundances of transcripts of genes that regulate the cardiovascular system and the response to oxidative stress. To our knowledge, this is the first study describing transcriptome-wide effects for different classes of DLCs in fish. These findings represent an important first step in describing complete toxicity pathways (adverse outcome pathways) for the exposure of fish to DLCs, which will be important in context with informing risk assessments of native fish species with regard to DLC toxicity.

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Abstracts-Vorträge The NORMAN network is a permanent self-sustaining network for the monitoring and biomonitoring of emerging environmental contaminants. The NORMAN working group on Bioassays (Bio WG) focuses on the application of bioanalytical tools for environmental quality monitoring. A main objective is to provide recommendations for the implementation of effectbased tools into regulatory frameworks. In this context, a blind interlaboratory study (ILS) was performed. The aim was to verify if a bioassay battery conducted in different laboratories following own protocols would produce comparable results when testing spiked surface water extracts. The lead in planning and organizing was taken by the Department of Ecosystem Analysis (ESA), RWTH Aachen University (DE). The ILS bioassay battery included acute-toxicity assays with organisms from different trophic levels (Algae, Daphnia, Zebrafish embryos); and mechanism-specific bioassays for estrogenicity (YES, ER-Luc cell lines) and mutagenicity (Ames fluctuation) assessment. Three to four participants performed each bioassay, including: BfG ( . Pristine water from a reference site was concentrated 10.000 times with large volume solid-phase extraction. Four emerging pollutants were used for spiking: triclosan, acridine, 3-nitrobezanthrone and 17-alpha-ethinylestradiol. Extracts were spiked with either single chemicals or a mixture, in concentrations aimed to produce full dose-response curves in bioassays. The spiked extracts were prepared, separated in aliquots, identified with codes, and sent to the participating laboratories. Standardized bioassay methods (OECD, ISO) were recommended but not mandatory, and biotesters 59 could use their own protocols. Results were sent to RWTH, and a summary of the full ILS was provided to the ILS participants. In October 2014, a workshop was held at RWTH Aachen to present and discuss the ILS results. Bioassays produced mostly highly comparable results, even when protocols differed significantly. Suggestions for future improvements include harmonization of methods for data analysis and results evaluation. An important expected outcome of the ILS is the promotion of biotesting for water quality monitoring at the level of European policy-makers.

Increased reverse osmosis concentrate toxicity following application of antiscalants -Acute toxicity tests with the amphipods Gammarus pulex and Gammarus roeseli Feiner Mona, Technische Universität München
Sebastian Beggel (sebastian.beggel@tum.de) Nadine Jäger (Nadine.Jaeger@wvv.de) Jüergen Geist (geist@wzw.tum.de) mona.feiner@tum.de In reverse osmosis, a frequently used technology in water desalination processes, wastewater (RO concentrate) is generated containing the retained solutes as well as socalled antiscalants (AS), i.e. chemical substances that are commonly applied to prevent membrane-blocking. In this study, a risk assessment of a possible discharge of concentrate into a small stream was conducted. The acute toxicity of two concentrates containing two different ASs and of concentrate without AS to the amphipods Gammarus pulex and Gammarus roeseli was studied. Mortality of gammarids exposed to the concentrate without AS was not different to the control, whereas concentrates including ASs caused mortality rates up to 100% at the highest test concentrations after 168 h. Resulting EC50-values were 36.2-39.4% (v/v) after 96 h and 26.6-58.0% (v/v) after 168 h. These results suggest that the ecotoxicological relevance of antiscalants is greater than currently assumed. Wood ash contains high amounts of plant nutrients such as phosphorus, potassium, calcium as well as several micro nutrients. In this study the plant growth enhancing properties of Sitka spruce (Picea sitchensis) wood ash were contrasted with its toxic action. The growth of common duckweed (Lemna minor) exposed to wood bottom and fly ash solids (as suspensions) and corresponding leachates was assessed in ultra-oligotrophic and eutrophic media. Doses stimulating and inhibiting plant growth under these conditions were determined. For purpose of comparison to standard waste toxicity data, ash solids and leachates were also tested as neutralized preparations. Suspended bottom and fly ash solids improved L. minor growth up to concentrations of 2.5 and 5 g/L respectively. Leachates promoted growth up to 10 g ash equivalents per litre, but for bottom ash only. Beneficial effects of ash were most pronounced on ultra-oligotrophic growth medium. In contrast, no significant growth promoting effect of wood ash supplementation was found in (eutrophic) standard test medium. Severe inhibition (EC50) of common duckweed biomass and frond growth by fly ash was observed in nutrient deficient (12-18 g/L), standard (18-22 g/L) and neutralized standard media (37-61 g/L). In comparison, higher doses of bottom ash were required to incur the same level of growth retardation in ultra-oligotrophic and eutrophic media (35-50 g/L) and in neutralized standard medium (70-95 g/L).

Energy ashes from virgin wood fuel show different potentials for growth promotion and toxicity in
It is argued that growth promotion is due to the substantial content of nutrients but may be conditional upon the presence of ash solids. Phytotoxicity is due to both the elemental composition of the ash, its alkaline character, and possible interactions between these two factors. This study shows that the margin between growth promoting and toxicity inducing concentrations can be enlarged through ash neutralization. This study further underlines the importance of the receiving environment (nutrient status and pH) in determining the balance between toxicity and growth promotion, and thus the impact of ash spreading on plant growth.

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Abstracts-Vorträge There are indications in literature that terrestrial life stages of amphibians may be more sensitive to certain contaminants than birds or mammals. It is hypothesized that dermal exposure is potentially a significant route of exposure and toxication for amphibians, as there is evidence that their skin is more permeable than the skin of other vertebrate species. Thus, higher amounts of chemicals might enter systemic circulation by dermal uptake. Furthermore, their skin as an organ with essential functions for the organism might be impaired by dermal contact to xenobiotics.
So far, no guidelines exist to investigate dermal exposure and effects of chemicals on amphibians. This work is targeted to develop in vitro test systems as a possible model to assess the dermal uptake and toxicity of test compounds by minimizing vertebrate testing. To this end, established toxicological (mammal) test procedures were adapted to amphibian skin (Xenopus laevis): to address dermal uptake, the dermal absorption in vitro method (OECD TG 428) was tested. This was done by applying reference compounds -caffeine and testosterone -topically to freshly excised skin. Skin permeability to both substances was significantly higher compared to human data. Caffeine permeated faster across the skin than testosterone, with ventral skin tending to be more permeable than dorsal skin. As usage of frozen stored mammal skin is accepted, frozen stored skin of X. laevis was tested in parallel. By freezing (without additional preservation measures), skin permeability to caffeine was increased. To address dermal toxicity, the skin corrosion in vitro method (OECD TG 431) was used based on the MTT test. After topical application of different acetic acid dilutions to freshly excised skin, a dose-dependent reduction of skin viability was detectable.
This work has shown that the chosen methods can be applied successfully to amphibian skin, providing the basis for further investigations. In the future, well established in vitro test systems and a broad dataset of chemicals may help to assess potential amphibian risk from chemicals without the need for extensive vertebrate animal testing. The Swiss Soil Monitoring Network NABO was set up in the mid-1980s to detect temporal changes of soil quality in the long-term. Initially, soil pollution by heavy metals and acidification were the main issues. In the meantime the analysis of organic soil pollutants improved remarkably. Consequently, soil monitoring networks are able to integrate a larger array of organic soil pollutants using either samples from new sampling campaigns or archived soil samples. Due to the large number of organic chemicals and the limited financial resources, a well-defined conceptual approach is needed to define those to be integrated in soil monitoring. Therefore, we follow a stepwise approach taking into account:

(i) Prediction, (ii) Status survey, (iii) Risk assessment, (iv) Monitoring
This approach might be applied for various groups of chemical compounds. The present study focuses on pesticides. First, selected soil samples from NABO sites were used to establish a multi-residue analytical method (stage i; Krauss & Keller, 2010). Currently, the methodology is refined to analyse a broader range of pesticides; subsequently, it will be applied to agricultural NABO monitoring sites (stage ii). The target substances were selected using the following data bases and approaches: • Results stage i: pesticides and transformation products detected in first screening.
• Management data of NABO sites: frequency and amount of pesticides used by farmers.
• Modelling soil concentrations: estimation of the temporal evolutions.
• Risk assessment: evaluation considering the estimated concentrations.
The intended analyses will provide an overview of the pesticides exposure of NABO soils. Thereafter, a risk assessment will help to rank the detected pesticide concentrations in soils (stage iii). However, this will involve various issues, e.g. the risk by mixtures of various substances (Wittmer et al. 2014), to finally decide which pesticides are to be monitored (stage iv). There are many thousands of organic chemicals on the market and it is a challenging task to identify those with a potential long-term environmental contamination. History has shown that chemical-intensive economies continually cause contamination of the environment, that in many cases, remain undetected for years. A point in case is perfluorinated alkyl substances (PFASs), which have been used since the 1970s but were detected in the environment only after 2000. Analytical campaigns and monitoring programs can cover only a certain selection of chemicals. Therefore, strategies for identifying priority chemicals for analytical measurements are needed. In this study we aim to identify relevant chemicals starting from an extensive computer-based screening from the Swiss customs statistics and other databases in Switzerland, followed by a complementary monitoring campaign of representative soils.

References
The first step in the study was to develop a phase partitioning multimedia environmental fate model with dimensions of Switzerland to identify chemicals with a presence of 90% or more in soil. The results show that 2550 out of 9187 chemicals studied have high affinity to this environmental matrix. As a first approach due to the high number of candidates, a subgroup of only halogenated chemicals (˃ 500 chemicals) were prioritized to facilitate the analytical analysis. Halogenated substances have a well characteristic isotopic pattern and mass defects outside the soil matrix making their identification easier.
Target and suspect screening was performed in 14 sites from the Swiss National Soil Monitoring Network (NABO) chosen according to land use and vicinity to industrial and urban areas, as well as previously measured soils with persistent organic chemicals such as polychlorinated biphenyls. Soil samples were extracted by means of pressurized liquid extraction and analyzed by liquid chromatography followed by electrospray ionization (ESI) coupled to high resolution mass spectrometry (HRMS/MS). Preliminary results show that the combination of the developed multimedia fate model and HR-MS analysis resulted in the successful identification of different antibacterial substances, fungicides, fluorosurfactants, as well as the tentative identification of further chlorinated, brominated and quaternary ammonium compounds.
Ferrari (1) (1)  Wood preservatives are biocidal products used to protect wood building materials from biological attacks. For wood used for outdoor applications (Use class 3 or 4), the chemical substances employed are likely to leach into the soil and may then pose a potential risk for the soil organisms and the essential functions they performed. Currently, the available toxicity data for terrestrial organisms regarding the active ingredients present in wood preservatives are still scarce. The aim of this project was to synthesize the available knowledge regarding the toxicity for terrestrial organisms of representative active ingredients contained in wood preservatives and authorized for use in Switzerland, and to provide missing data where necessary. A market analysis was performed to determine the active ingredients the most frequently used and present on the Swiss market. Four wood preservatives containing the selected active ingredients, either present as a single substance or in a mix, were chosen for the ecotoxicological evaluation. They contained: 1) IPBC, 2) Propiconazole, 3) Boric acid and Copper(II)hydroxide, with Chromium as fixing agent; and 4) Copper(II)carbonate-Copper(II)hydroxide, Didecylpolyoxethylammoniumborat (DPAB) and Boric acid. Literature search carried out about the selected active ingredients showed a lack of information regarding the toxicity of IPBC, Propiconazole and DPAB for terrestrial organisms as well as regarding mixture toxicity for the active ingredient combinations. Therefore, collembolan reproduction and earthworm avoidance tests were performed to determine effect concentrations, either for the single active substance or for the active ingredient mixture contained in the wood preservatives. Similar range of toxicity were obtained for collembolans and earthworms for IPBC whereas earthworms showed to be more sensitive than collembolans to Propiconazole. The 2 wood preservatives containing a mix of active ingredients showed a quite high toxicity for collembolans but even greater for earthworms. The toxicity induced by the mixture of active ingredients was far below the toxic effects observed for the individual substance itself. This project will provide the basis for future studies aiming at characterizing the impact of wood preservatives on soil organisms in microcosms or in field conditions.

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Abstracts-Vorträge  (1), Etienne Vermeirssen (2), Nicolas Eichenberger (3), Marin Huser (4), Rico Ryser (5); (1)  are recognized as a global problem contributing to the degradation of ecosystem quality. Therefore, the aim of this field study is to causally link real effects resulting from microbial community-level exposure to complex mixture of MPs present in WWTPs effluents. To achieve this goal, we combined time-integrative passive sampling technologies with the assessment of extract toxicity via bioassays; using in-situ sampled periphyton.
Periphyton were sampled up-and downstream of four WWTPs effluents in Switzerland and exposed to various dilutions of extracts from passive samplers that were immersed at the effluent of each site. Tolerance of communities to passive sampler extracts was determined according to the pollution-induced community tolerance (PICT) concept by measuring the inhibition of various functional endpoints. Specific tolerance of the heterotrophic component of periphyton was measured by 14C-leucine incorporation and MicroRespTM method to measure secondary production and heterotrophic respiration, respectively. Specific tolerance of the phototrophic component of periphyton was assessed by 14C-carbonate assimilation and algal fluorescence to measure primary production and photosynthetic yield, respectively. Additionally, we examined shifts in the structure of up-and downstream periphyton by performing a community level physiological profile (CLPP) and a DNA fingerprint analysis.
Results showed that despite low concentrations of MPs detected downstream of the effluents, phototrophic and heterotrophic components of the sampled periphyton displayed increased tolerance towards these MPs. Interestingly, in comparison to heterotrophic functional endpoints, tolerance increase of phototrophic endpoints was variable among sites. These findings might give a first indication on the MPs composition in the effluents (dominance of herbicides or bactericides), which was confirmed by analytical identification of MPs in the passive samplers' extracts. The observed effects were accompanied by changes in the microbial CLPP and in molecular diversity. Overall, our study highlights the sensitivity of the proposed approach to detect effects of low MPs concentrations occurring in the field and to establish a causal link between exposure and the observed ecological effects on freshwater microbial communities.

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Abstracts-Vorträge Xenobiotics in soil dissipate by transport, binding and degradation processes that depend on the physicochemical properties of the substance and the soil, and on environmental conditions. We will report on the immobilization mechanism of chemicals in soil. If isotope labelled compounds are used to establish a mass balance of their fate in soil, combustion of the thoroughly extracted soil usually reveals a third component beside extractable and volatile incl. mineralized residues, i.e., so called non-extractable residues (NER). NER vary in the amounts that are formed and in the type of binding (covalent vs entrapped) but most often nothing is known on the chemical structures of NER and the potential for long-term release and bioavailability to plants and soil organisms. As examples we will present data on the fate of various chemical compounds.
If bacteria use pollutants as carbon source, they will incorporate the pollutant-derived carbon and other elements into their biomass which later will be incorporated in soil organic matter and thus contributes to NER formation. This has been demonstrated in studies on the biodegradation of several isotope labeled pesticides and pharmaceuticals in soil, where the contribution of microbial biomass residues to NER in soil was quantified. The high amount of label found in biomolecules (fatty acids, amino acids) indicated that large amounts of NER of readily degradable chemicals are of biogenic origin. However, NER of persistent xenobiotics also contain immobilized parent compounds or their primary xenobiotic metabolites. Examples and a scheme for the environmental risk assessment of NER differentiating xenobiotic, either entrapped (type I) or covalently bound (type II), and biogenic residues (type III) will be presented.
Risk assessment of a chemical in soil considers the formation of NER as a process of irreversible binding to soil; such residues are defined as not bioavailable. However, as shown in the examples of the lecture, xenobiotic NER formation may be considered as long-term stabilization of a chemical in soil from which parts may be released. It is reasonable to assume that all chemicals will form NER to various extents leading to complex mixtures of pollutants and their transformation products in soils and sediments. We therefore propose that the environmental risk assessment of chemicals should consider not only dissipation half lives (DT50) due to transport processes, degradation, and formation of NER; rather the potential subsequent release of non-extractable parent substances and xenobiotic metabolites should be taken into account. On the other hand, biogenic NER, formed by readily biodegradable chemicals, are of no environmental concern.

Distribution patterns of synthetic pyrethroids in estuarine and delta sediments in Europe Schinkel Lena, Helmholtz-Zentrum für Umweltforschung
Riccardo Massei, Martin Krauss, Werner Brack Lena.schinkel@gmx.de Synthethic pyrethroids (sPYR) are a class of insecticides used in crop protection and in biocidal applications. They are of emerging concern because of their high toxicity towards aquatic organisms. They sorb to soil organic matter and enter water bodies via run-off, where they potentially accumulate in aquatic sediments and can affect benthic organisms. In this study 12 sPYR were chosen for target analysis based on the approval for agricultural and biocidal application within the European Union.
A GC-NCI-MS/MS method has been developed to analyse sPYR in aquatic sediments. A multi-target method was used for sample preparation, including pressurised liquid extraction with subsequent normal phase column chromatography. Massive signal enhancement of sPYR was observed when analysing sediment matrix. Therefore a matrix-matched calibration was performed with non contaminated sediment. Method detection limits ranged between 0.02 and 1.43 ng g 1. Recoveries varied between 62 and 82 %. So far, sediments from different sampling spots at the delta of Danube (3 spots) and Po (4 spots) were analysed for the occurrence of sPYR. Six target compounds were detected in at least one sample (range 0.01 -3.55 ng g -1 ). Highest levels were detected for cypermethrin (range 0.71 -3.55 ng g -1 ). Toxic units (TU) has been derived based on a previous study about sediment toxicity concerning H. azteca (Amweg et al 2005). TU ranged between 0.01 and 0.18 for individual sPYR. This indicates that the found level theoretically did not cause acute toxicity. However, possible chronic toxicity cannot be excluded.
Sediments of 12 further European river estuaries will be screened for the occurence of sPYR and distribution patterns will be statistically evaluated.

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Abstracts-Vorträge  (2), Beer M (2), Tamborini L (3), Beckmann M (4), Arpagaus S (5), Caduff A (6), and Lanfranchi M (7); (1)  The aim is to investigate the toxicological effects of chemicals extracted from water samples upstream and downstream of the biggest wastewater effluent outflow as well as from a reference site. In addition to chemical screening all samples were analyzed with a battery of in vitro cell-based bioassays. The samples were investigated for a wide range of endpoints including receptor-mediated modes of action (ERα -estrogen receptor alpha, AR -androgen receptor, PPARy -peroxisome proliferation receptor gamma, PR -progesterone receptor, GR -glucocorticoid receptor) and adaptive stress responses (ARE -oxidative stress response, NFkB -inflammatory stress response, p53 -genotoxicity). Potential antagonism was also measured for all receptor mediated assays. The results showed a clear toxicological pattern between the different sampling sites. The most responsive endpoints were estrogenicity, anti-androgenicity, peroxisome proliferating responses and inflammation. This study showed the relevance of a well working wastewater treatment before releasing it into the environment as well as the monitoring of water quality.

Schäfer Ralf B., Institute for Environmental Sciences, University Koblenz-Landau
Leo Posthuma, Centre DMG (Sustainability, Environment and Health), RIVM, Bilthoven, The Netherlands schaefer-ralf@uni-landau.de In our presentation, we raise three aspects that limit the relevance of ecotoxicology and risk assessment for real-world problems. First, we show that ecotoxicology has a strong focus on species and individuals, and that ecosystem-and community-based research plays a minor role. That is at variance with the latter often relating to the endpoint of concern. This aspect is mirrored in the attitude of several ecologists towards ecotoxicology. By contrast, ecologists conduct theory-driven research on communities and ecosystems, but rarely handle chemical stressors. Second, simple models are often regarded as a solution to extrapolate from known (single-species test) toxicity data to the ecosystem-and landscape-level. We argue that while such models are generally useful, their predictions need to be falsifiable under real-world conditions and should be tested accordingly with field data. Various studies demonstrate lessons to be learned here. Moreover, we caution against the idea to bridge the scales from biomarkers to ecosystems with a too narrow focus on chemical-oriented approaches as well as ignorance of ecological patterns. Third, we warn against the reification of entities from risk assessment such as the NOEC, HC5 or RAC, which implies handling the latter concepts as facts. Giving examples from medical epidemiology and from previous eco(toxico)logical studies, we argue that scientific hypotheses on the impacts of chemical mixtures in natural systems, for example in ecotoxicological epidemiology, should rely on science-based effect measures rather than be based on regulatory concepts like HC5. Only then will scientific insights provide improved fundaments to risk assessment and management. We end with suggestions how ecotoxicology could increase its relevance for the real world situation.

A critical review of prochloraz effects in fish Perseke Lea, Dr. Knoell Consult GmbH
Lennart Weltje lea.perseke@web.de The imidazole fungicide prochloraz is registered in the EU for use on various crops and is one of the most data-rich substances regarding chronic toxicity to fish. The aim of this literature review was to investigate the available literature for consistency in observed effects and mechanisms and for potential differences in sensitivity between fish species and to discuss the relevance of prochloraz exposure for fish populations in the field.
Available literature on the effects of prochloraz on fish was identified through Web of Science, regulatory data and OECD test guideline validation studies. Results from a total of over 50 in vivo experiments are included in this review. Endpoints of interest were apical effects (survival, growth, reproduction, development) as well as biomarkers. The dominant effect of prochloraz in fish seems to be the inhibition of aromatase (CYP19), an enzyme which catalyses the conversion of testosterone to 17β-estradiol. Inhibition of aromatase leads to a lack of 17β-estradiol and a surplus of testosterone, causing various effects in (female) fish, such as reduction of 17β-estradiol concentrations, reduction of vitellogenin or a shift in the sex ratio towards males.
The effects reported in the literature were consistent with the known modes of action and showed that prochloraz may affect the endocrine system of fish and cause effects on growth, with LOECs roughly ranging from 30 to 300 μg/L. Apart from a few exceptions, effects followed monotonic concentration-response curves. The sensitivity of different fish species and endpoints is quite comparable, except that medaka might be more sensitive regarding reproduction. Aquatic invertebrates and algae show a higher sensitivity to short-term exposures than fish.
Measured environmental concentrations of prochloraz in natural surface waters are about 1000 times below the median concentrations causing effects in laboratory tests with fish under continuous exposure. These data suggest that the exposure of prochloraz in the field is too low to cause effects in fish. This notion is supported by the fact that no effects related to prochloraz have been found in natural fish populations. Environmental exposure to plant protection products (PPP) can often occur in scenarios wherein multiple PPP are applied or persisting within the same ecosystem. While current regulatory programs evaluate risks on a chemical-by-chemical basis, there is considerable interest in assessing the potential impact of concurrent exposures to multiple PPP. The potential risk associated with PPP concentrations measured in approximately 3000 surface water samples from across the USA (1992 -2001) were evaluated using a tiered approach recommended by the World Health Organization (WHO). The lack of a reported ecotoxicity threshold (i.e., benchmark value) and the occurrence of non-detectable PPP in some monitoring samples were considered with regard to their potential impacts on the risk analysis. In the first-tier assessment, the potential risk from the exposure to each individual PPP was calculated based on its concentration and the lowest aquatic life benchmark (U.S. EPA's Office of Pesticide Program). The potential risk associated with combined exposure of PPP was conservatively derived by assuming a common mode of action and additivity for these effects. The results from the Tier 1 assessed with the MCR approach identified 7.6% of the samples for which a risk alert could not otherwise be identified when evaluating the risk on a chemical-by-chemical basis. In the tier 2 assessment, consideration was given to information on mode of action and defined target species. Separate risk assessments were performed for each ecotoxicity benchmark, which would be considered a Tier 2 analysis in the WHO framework and the Cefic-MIAT decision tree. The findings of Tier 2 were that potential risk from combined exposures was an issue in only 1% of the samples. These concerns were limited to a small subset of PPPs for which only invertebrates and non-vascular plants were identified as being most sensitive. This tiered risk assessment approach combined with the MCR analysis strongly supported the value of categorizing monitoring samples in terms of whether the combined exposures pose little or no risk, where one or more chemicals exceed safe concentrations, and finally to identify exposures where several substances could make a significant contribution to the combined risk to specific non-targets organisms.

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Abstracts-Vorträge Abstracts-Vorträge years. This appears to be caused not by a single factor but by the cumulative impact of multiple stressors. One key factor is the infection of brown trout with the myxozoan parasite, Tetracapsuloides bryosalmonae, the etiological agent of proliferative kidney disease (PKD). The disease is widespread among brown trout populations in Switzerland. PKD-induced mortalities depend on water temperature, with negligible mortalities occurring at temperatures up to 12 -14C, but strongly increasing mortalities at higher water temperatures. During the last decades, water temperatures of Swiss rivers experienced a climate changerelated increase of water temperatures, both of mean values and of summer maxima. The increase was most pronounced in the lowland regions (< 800 m altitude), which is also the region where the highest frequency of PKD infections is observed. The spatial and temporal co-incidence between PKD infection and changes of water suggests a role of this stressor combination in the observed brown trout decline. Brown trout populations in lowland river stretches can be additionally impacted by chemical pollutants due to the strong industrialization and urbanization of the Swiss lowland regions. Chemical exposure could increase susceptibility of trout to the parasite, since many chemicals, particularly compounds binding to estrogen and arylhydrocarbon receptors, have immunosuppressive effects in fish. In conclusion, the brown trout decline in Swiss rivers appears to be mediated through a combination of environmental stressors.

Segner Helmut, Cetre for Fish and Wildlife Health, University of Bern
In eutrophic lakes cyanobacterial blooms occur frequently, triggering a cascade of devastating effects for the lake community. Cyanobacteria affect other species in multifarious ways: first, some cyanobacteria taxa are well-known for producing secondary metabolites, which are highly toxic for humans and wildlife. However, the production of cyanotoxins varies within species, with some strains lacking the necessary genes. Second, a high turn-over of blooming cyanobacteria leads to an oxygen shortage in the lake due to decomposition of dead cells at lower depths. Third, the dominance of cyanobacteria in the phytoplankton community will lead to a shift in algal food quality for herbivorous zooplankton, which in turn affects higher levels of the food web. Cyanobacteria lack essential fatty acids, impairing herbivore growth, reproduction, and metabolism. Since Daphnia play a key-role in lake and pond food webs, the direct effect of cyanobacteria has intensely been studied. Whilst the role of cyanobacteria as poor nutrient source for Daphnia is now well-understood, the importance of morphology and toxin production is still controversial. Moreover, cyanobacteria might also have indirect effects on Daphnia in natural systems, by modifying host-parasite interactions. Here, we will show the synchronous occurrence of cyanobacteria and epidemics of the common Daphnia gut parasite Caullerya mesnili in a middle-sized peri-alpine lake over several years. We further show the results of an infection experiment with Microcystis aeruginosa and discuss the involvement of environmental parameters, cyanobacteria in general and microcystins in Caullerya epidemics. The ectoparasitic mite Varroa destructor and agricultural chemicals can have drastic effects on honey bee, Apis mellifera, health; however, possible combined effects of pesticides and V. destructor have so far been unexplored. Here, we evaluated possible sub-lethal (teneral body mass) and lethal (longevity) time-lag effects of two neonicotinoids (thiamethoxam and clothinadin) and V. destructor on individual workers alone and in combination. Queenright colonies of similar strength (N=20) were randomly allocated and exposed to one of two treatments (1. Both neonicotinoid pesticides or 2. No neonicotinoid pesticides) for 8 weeks in late Spring 2014 that represented environmentally relevant conditions. One (Summer 2014) and 16 (Fall 2014) weeks post treatment exposure, emerging workers from all colonies were individually screened for mite infestations and transferred to cages (N=3 cages per colony; 10 workers per cage) to examine possible time-lag effects of the pesticides and mite on survival and body weight. In Summer 2014, longevity was reduced by V. destructor, but not by thiamethoxam. Bees from the combined treatment showed mortality rates similar to the V. destructor treatment. However, summer body mass of combined V. destructor and thiamethoxam exposed bees was lower compared to all other treatments. Pesticide treatments alone had no significant influence when compared to the controls; however, V. destructor groups showed reduced body mass measures significantly lower than control and pesticide but not as severe as in the combined treatment. In contrast, Fall 2014 bees exposed to both mites and thiamethoxam showed reduced longevity when compared to all other treatments from summer and fall. Furthermore, body mass from both V. destructor and V. destructorpesticide treatment were lower compared to the same summer treatments. An identical experimental approach was performed after overwintering of the colonies in Spring 2015 (~37 weeks post pesticide exposure). The spring observations strongly mirrored results observed during Summer 2014. Our data suggest previously overlooked time-lag effects of combined pesticide-mite exposure that could be important to honey bee colony overwinter survival.

Pillai Smitha, Eawag
Alena Tierbach, Renata Behra, Kristin Schirmer smitha.pillai@eawag.ch The rapid development of nanotechnology lead to a rapid proliferation of nanomaterial use in consumer products. They in turn are likely to become a source of different nanoparticles in the environment. Currently, a general lack of information on the ecotoxicology of engineered nanoparticles (NP) prevents an accurate evaluation of their environmental risks. The way forward is to adopt a multidisciplinary approach combining chemical, biological and particleanalysis expertise to estimate the toxicity of any particle specific effects in aquatic organisms. In our study we aim to obtain a mechanistic and systemic understanding of the toxicity of manufactured nanomaterials (MNMs) in the freshwater alga, Chlamydomonas reinhdardtii. For the acute and chronic toxicity analysis several endpoints including growth, oxidative stress and damage, energy and photosynthesis was estimated. We found, not surprisingly, that most of toxicity of silver and zinc nanomaterials is caused due to dissociation of metal ions. The surface modifications due to aging and other subsequent treatment alters the toxicity and bioavailability will also be studied. In addition, we intend to use an integrated systems biology approach, including transcriptomics, proteomics and metabolomics to discover mechanisms of toxicity at the molecular level.
Illicit psychoactive drugs released into aquatic environment as a result of human consumption and incomplete degradation during wastewater treatment, may be potentially harmful to fish due to conservation of major drug targets across vertebrates. However, little is known not only about the effects but also about the internal accumulation and distribution patterns of such compounds following waterborne exposures. Here, we studied the toxicokinetics of cocaine, a widely used illicit drug, frequently detected in surface waters. Temporal profiles of uptake and excretion following waterborne cocaine exposure were characterized in zebrafish at 5-8 days post fertilization (dpf). External and internal concentrations of cocaine and major metabolites were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Internal drug distribution was studied by matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), for the first time optimized for use in zebrafish larvae. Our results demonstrated the uptake and biotransformation of cocaine in zebrafish larvae. Elimination occurred after transfer into clean water, however, a plateau was quickly reached, with about one third of initial concentrations still retained after 48 hrs of depuration. MALDI-MSI showed cocaine accumulation in the trunk and in the head region: more precisely, in the brain, but also, surprisingly, in the eyes. In dissected brain, eyes and trunk, cocaine was detected in all the measured tissues, with a highest concentration found in the eyes. After 48 hrs of depuration, most of the remaining cocaine was found in the eyes, while concentrations in the brain and trunk became very low. Our results show that, following waterborne exposure, cocaine is distributed not only to the target organ -brain, but also to the eyes, where it remains for a long time. Perhaps this is one of the reasons that only hypoactive but not hyperactive responses to cocaine have been observed by us and others in behavioural assays with zebrafish larvae. Further studies are needed to evaluate the potential influence of drug accumulation in the eyes on fish vision and behaviour, but also to understand whether the observed distribution patterns are specific to cocaine or could be a more general mechanism relevant for other pharmaceuticals as well.

Rehberger Kristina, Centre for Fish and Wildlife Health, University of Bern
Inge Werner Oekotoxzentrum Eawag-EPFL, Dübendorf and Lausanne Helmut Segner Centre for Fish and Wildlife Health, University of Bern helmut.segner@vetsuisse.unibe.ch Numerous legacy and emerging contaminants including persistent organic pollutants and pharmaceuticals are (potentially) immunotoxic to fish. It was shown that exposure of fish to immunotoxic contaminants can adversely affect immunocompetence and pathogen resistance, and thereby may indirectly contribute to the increasing occurrence of pathogeninduced fish mortalities. This situation leads to the question how to screen and assess immunotoxic activities of environmental contaminants. Currently, there exists no established inventory for immunotoxicity testing and assessment in ecotoxicology. The present study aims to examine the suitability of in vitro assays using fish immune cells to screen for potentially immunotoxic chemicals. To this end, primary head kidney leukocytes (resting and stimulated) of rainbow trout (Oncorhynchus mykiss) were exposed to non-cytotoxic concentrations of xenobiotics with different modes of action. The panel of test compounds includes narcotic chemicals, specifically acting non-immunotoxic chemicals, and immunotoxic chemicals which act through different receptor pathways. The selection of the endpoints for detection of an immunomodulatory activity of the test compounds was based on a previously conducted literature review, which identified phagocytic activity, oxidative burst activity, and the expression of cytokines to be most frequently measured and responsive in fish. The results of the present study will clarify whether simple in vitro screening assays are able to capture immunotoxic potentials of xenobiotics irrespective of the specific MoA, and thus may be useful for chemical prioritization in ecotoxicological hazard assessment.

Schlotz Nina, Universitätsklinikum Freiburg
Stephan Flemming, Stefan Günther, Evelyn Lamy nina.schlotz@uniklinik-freiburg.de Many of the over 800 substances with suspected endocrine activity have been individually assessed in various bioassays. However, environmental or dietary exposure to single endocrine active chemicals (EAC) is rather the exception; the realistic scenario is a constant challenge by numerous EAC simultaneously. Yet, there is a surprising gap in our knowledge on effects of co-exposure to these substances of concern.
Estrogen receptor (ER) activation as well as induction of proliferation in ER positive cells are assumed to be major hallmarks of estrogenic activity. Measured jointly, both endpoints can provide reasonable estimations regarding the disruptive potential of the respective substances. We investigated mixtures of industrial chemicals, pesticides, as well as phytochemicals. Components of the mixtures were chosen due to their known or suspected estrogenic activity, produced quantity and probability of regular exposure.
Using the ER-CALUX® reporter gene assay and a cell proliferation assay based on the human breast cancer cell line T47D expressing both ER α and β we tested for the potential of EAC mixtures to 1) influence ER-mediated gene expression and 2) induce proliferation in this cell line. We then examined possible interactions between chemicals (additivity, synergy, antagonism) employing a mathematical model based on dose-response data obtained for the single chemicals.
This approach highlights benefits and challenges of in vitro bioassays for assessment of endocrine activity and provides insights into mixture effects of EACs in a human context.  Marine microplastic (< 5 mm) water pollution has met growing public and scientific interest in the last years. The situation in freshwater environments remains largely unknown, although they appear to play an important role as part of the origin of marine pollution. Apart from the physical impacts on biota, chemical effects are to be expected as well, especially with smaller particles. This study aimed at assessing the situation for the Swiss Lakes Geneva, Constance, Neuchâtel, Maggiore, Zurich and Brienz, and identifying potential impacts. Lake surface transects, a few rivers as well as urban runoff outlets and WWTPs have been sampled using a floating manta net, and beach sediments have been analysed. Plastics have been sorted in types (fragments, pellets, cosmetic beads, lines, fibres, films, foams) and composition (PP, PE, PS, etc.). Fishes and water birds have been dissected to assess their potential exposure, and analyses of the hydrophobic micropollutants adsorbed to the microplastics as well as some potentially toxic additives they contained have been conducted. It appears that all lakes are affected by this pollution, microplastics of all types and diverse composition having been found in all samples. Birds and fishes are prone to microplastic ingestion, and all the tested chemicals (both adsorbed micropollutants and contained additives) were found above the detection limit, and often the quantification limit. The sources and their respective contribution need to be confirmed and quantified, and the ecotoxicological impacts also need further investigation. Other questions remain open, including the transport and fate of the plastic particles in the environment.

Testverfahren zur Beurteilung der Behandelbarkeit von Abwasser mit Ozon
Schindler Wildhaber, Y.a,b, Mestankova, H.a, Schärer, M.b, Schirmer, K.a,c,d The efficiency of wastewater treatment plant (WWTP) upgrading with powdered activated carbon (PAC) filters for ecosystem health was investigated at three rivers in Southern Germany, the Schussen, the Schmiecha and the Eyach (tributaries of Lake Constance, Danube and Neckar). At the Schussen, the WWTP Langwiese, Ravensburg has been expanded by such a filter in autumn 2013. At the two other rivers, the WWTPs Albstadt-Lautlingen and Albstadt-Ebingen were equipped with PAC-filters more than 20 years ago.
The benefits of the WWTP upgrade for the ecosystem of the Schussen, which have been in the focus of the BMBF-funded project SchussenAktivplus, have recently become obvious: In mean, 80% of micropollutants and related effect potentials and more than three orders of magnitude of (resistant) microbes can be spared to the river system and finally also be kept away from Lake Constance which is an important drinking water reservoir. Although up to now, advantages for the ecosystem of the Schussen could be investigated only for a time span of 1 year, thus only on a short-term run, some positive implications were already visible: Fish health was evidently improved reflected by a better tissue integrity, less genotoxic effects and lower activity of biotransformation enzymes. Also the health status of invertebrates and community indices already showed signs of improvement.
Long-term effects of activated carbon filters were studied at the two other river systems. 20 years ago, before the connected WWTPs were upgraded with PAC filters, these rivers were highly polluted by chemicals from textile industry and rarely any organism could be found there. After the upgrade with PAC, the quality of the receiving water courses has continuously improved. In 2014, we investigated (1) tissue integrity, stress proteins and micronuclei in erythrocytes of resident trout, (2) developmental toxicity, (3) fish population structure, and (4) the integrity of the invertebrate community. The results clearly indicate a healthy status of fish, invertebrates and their communities both upstream and downstream of the two WWTPs, and reflect the high efficiency of the PAC filters for effluent cleaning and, thus, for ecosystem integrity on a long-term run.

Efficiency of advanced wastewater treatment technologies -Do we need a further treatment step? Giebner Sabrina, Goethe-University Frankfurt am Main
Sina Ostermann, Susanne Straskraba, Matthias Oetken, Jörg Oehlmann, Martin Wagner Giebner@bio.uni-frankfurt.de Conventional wastewater treatment plants (WWTPs) have a limited capacity to eliminate micropollutants like pesticides, pharmaceuticals and endocrine disrupting chemicals. Hence, wastewater is one of the major sources of micropollutants in aquatic ecosystems. One solution to increase the removal of these substances is the installation of additional treatment steps. Advanced technologies are based on oxidative (e.g. ozonation) or adsorptive treatment (e.g. activated carbon). The WWTP Eriskirch at the river Schussen in Baden-Württemberg is a medium-sized plant that has been upgraded with a combination of ozonation, sand filter and granulated activated carbon filter in a partial flow of the conventionally treated effluent. The efficiency of the applied technologies is assessed by means of chemical analyses and a wide range of ecotoxicological effect studies.
Endocrine effects present in the influent and effluents of WWTP Eriskirch were assessed by in vitro tests which include yeast-based reporter gene assays (estrogenicity, antiestrogenicity, androgenicity, anti-androgenicity), but also by in vivo studies, such as the reproduction test with the mudsnail Potamopyrgus antipodarum. Genotoxic effects in the samples were investigated with the Ames fluctuation test using the bacterium Salmonella thyphimurium.
The results indicate that the influent and effluents of the WWTP exhibit endocrine and toxic activities in vitro and in vivo. Estrogenic and anti-androgenic activities were relatively high in the influent and were significantly reduced after the conventional treatment. The advanced technologies further decreased the estrogenic activity by 45-80%, but remaining concentrations of estrogens still exceed environmental quality standards and hence might be environmentally relevant. Furthermore, we observed persistent anti-estrogenic activity in the conventional treatment that was not removed by the advanced technologies. In the reproduction test with P. antipodarum the number of embryos was significantly decreased in all effluents compared to the negative control. This might be due to reproductive toxicants which were not eliminated by the advanced technologies. The Ames test on mutagenicity revealed an increase of mutagenicity after ozonation compared to the conventional treatment. Sand filtration as post treatment step reduced this ozone induced mutagenicity. These results highlight the importance of a filter system as post treatment to an ozonation step to minimize toxic effects from potentially oxidation byproducts.
The investigations are part of the project SchussenAktivplus, funded by the Federal Ministry for Education and Research (BMBF) under project code 02WRS1281J.

Process performance of a PAC-UF system for the removal of micropollutants from a biologically treated municipal wastewater Svojitka Jan , Fachhochschule Nordwestschweiz
Jonas Löwenberg, Dominique Ritty, Armin Zenker, Harrie Besselink, Bart van der Burg, Andrea Schifferli, Cornelia Kienle, Thomas Wintgens jan.svojitka@fhnw.ch Adsorption on powdered activated carbon (PAC) is an efficient and flexible method for the re-moval of micropollutants from wastewaters. In the present study, tertiary treatment of effluent from a municipal wastewater treatment plant (WWTP) by PAC sorption was tested in combina-tion with an ultrafiltration membrane, to separate PAC from the water (PAC-UF).
A pilot system consisting of two identical membrane filtration units (each had a tank volume of 150 L) was used, so that the results from the two units could be compared. The pilot system was supplied with wastewater from a full-scale WWTP with continuous dosing of PAC and was operated for a period of approx. 14 months. The subsequent ultrafiltration step consisted of flat-sheet submerged ceramic membrane modules (0.8 m 2 each unit).
During different phases of operation, several operation parameters were modified and their influence on the performance of the filtration unit was evaluated. Modifications of the operation parameters comprised: aeration intensity for the sparging of the membrane surface, filtration flux, frequency of chemically enhanced backwash (CEB), the CEB protocol or the addition of FeCl3 as a coagulant. While the aeration and filtration flux had a strong influence on the fouling of the membranes, the addition of FeCl3 did not considerably improve the filtration performance.
In several measurement campaigns the samples of influent and effluents from both filtration units were analyzed for selected micropollutants (benzotriazole, sulfamethoxazole, carbamaze-pine, mecoprop, diclofenac) in order to assess their removal in the PAC-UF system under a given set of operational parameters. The highest removal efficiencies were observed for ben-zotriazole and carbamazepine, the lowest ones for sulfamethoxazole.
One measurement campaign was focused on the assessment of ecotoxicological effects of the effluents from the PAC-UF units. Effects on the luminescence of bacteria (Aliivibrio fischeri), on the photosynthesis and growth of single-celled green algae (Pseudokirchnerielle subcapitata) were assessed as well as hormonal effects in receptor activation assays (Yeast Estrogen Screen and CALUX® assays) and neurotoxic effects in an acetylcholine esterase inhibition assay.
The study was carried out in the European FP7 project Demeau (http://demeau-fp7.eu/). This research has received funding from the European Union's Seventh Framework Programme under the grant agreement no. 308339.

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Abstracts-Vorträge Micropollutants are continuously released into the environment in low concentrations. Concerns have been raised regarding their toxicity and their limited degradation during conventional wastewater treatment.

Enzymatic degradation of antibiotics in wastewater -A comparison between chemical analysis and ecotoxicological evaluation
Among these pollutants, antibiotics are frequently present in treated wastewaters and may pose an important public health issue in the near future, especially regarding the distribution of resistant bacteria. The treatment with an enzymatic approach could be a promising alternative or addition to existing technologies by using specifically designed enzymes degrading antibiotics and other micropollutants. So far, most studies evaluated their removal by chemical analysis only, but especially regarding transformation products (TP) an ecotoxicological assessment is equally important.
In this study osmosed water samples spiked with antibiotics and real wastewater samples were treated with a fungal laccase and analysed by chemical analysis and ecotoxicological assessment. The latter was based on a growth inhibition test with Bacillus subtilis for the detection of antibiotic activity.
We investigated the enzymatic degradation of a single antibiotic, tetracycline, with special interest in the formation of generated TPs. In addition, we also investigated the degradation of a mixture of 38 antibiotics comprising seven antibiotic families. These experiments were conducted in osmosed water. In addition, hospital wastewater samples were enzymatically treated, where apart from spiked tetracycline also 11 other antibiotics were detected.
Chemical analysis revealed that tetracycline and also the antibiotics in the mixture were successfully removed with an effectiveness of 70-100%. Moreover, the identified TPs of tetracycline did not induce a response in the ecotoxicological assays. However, the removal rates for the antibiotic mix detected by chemical analysis could not be explained by the reduction of the corresponding antibiotic activity by ecotoxicological evaluation, this was maybe due to generated TPs. Regarding the elimination of antibiotics in the wastewater samples, the removal was not as effective as observed in osmosed water. The antibiotic activity and toxicity even increased after enzymatic treatment.
These findings demonstrate the significance to combine chemical analysis with ecotoxicological evaluation. A removal of a compound does not necessarily translate into the reduction of 118 toxicity. This is especially important when evaluating a novel treatment technology like this enzymatic approach. Abstracts-Poster

Galay Burgos Malyka, ECETOC
Derek Urban storm-water runoff has been described as presenting one of the greatest challenges to ensuring clean water for human and ecological health (National Research Council 2008). Storm water overflows from combined sewer system, particularly in older cities and incomplete sewerage infrastructure in urban areas provide additional sources. The urban scenario also has to consider non treated or partially treated point sources from industrial origin, substances used for material protection (e.g. biocides in facade paint), external use by households (e.g. domestic pesticides, fertilizers) as well as diffuse inputs from dry and wet atmospheric deposition. A preliminary assessment of contaminants reported in urban storm waters and combined overflows shows that metals (Cu, Zn, Al, Fe, V, Pb), phosphorus, insecticides, and PAHs are chemicals of concern. As a consequence of these various sources, biota present in water catchments subject to increasing urbanization will be exposed to a diffuse mixture of chemical stressors.
This poster, which is an output of the SETAC Pellston workshop on "Simplifying environmental mixtures: An aquatic exposure-based approach via exposure scenarios" focuses on the urban discharge scenario that includes runoff from impervious surfaces, sewer overflows and industrial inputs.
Our aim is to develop an urban typology or typologies that can be used to both help understand the ecological response of urban rivers and simplify the risk assessment process for evaluating chemicals comprising this mixture. This requires detailed information on the chemicals of concern (concentrations, typical emission rates from various surfaces etc.) as well as on urban hydrology.

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Abstracts-Poster To protect façade renders from growth of bacteria, fungi and algae, biocides can be added to a render before it is applied onto a façade. These biocides will gradually leach out and thus have the potential to affect soil or aquatic ecosystems. In this study the leaching behaviour of biocides from three render formulations was evaluated: one render containing free, another render containing encapsulated biocides (Terbutryn, OIT, DCOIT) and a control render without biocides. The renders were applied onto extruded polystyrene panels and water samples were generated over nine immersion cycles of the panels. Concentrations of the biocides were measured and the toxicity of the first and ninth immersion samples was determined using bioassays. Toxicity to aquatic organisms was evaluated by assessing inhibition of photosynthesis and algal growth rate, inhibition of bacterial luminescence and inhibition of daphnid population growth. Toxicity to soil organism was assessed by determining avoidance behaviour of worms and reproductive output in springtails. Encapsulation reduced the leaching of Terbutryn, OIT, and DCOIT 4-, 17-, and 25-fold compared to free biocides. Generally, the toxicity of water from render containing encapsulated biocides was always lower than that of render with free biocides and toxicity was 4-to 5-fold lower for the ninth immersion day compared to the first immersion day sample for both free and encapsulated samples. For the aquatic organisms, inhibition of photosynthesis was the most sensitive endpoint, followed by algal growth rate, bacterial bioluminescence and daphnid reproduction. At all tested sample concentrations, none of the samples with biocides caused effects on soil organisms. Results from bioassays matched quite well with expected bioassay responses based on chemical analysis and the toxicity of the individual biocides. It could be concluded, that the toxicity of given concentrations on algae is explained by Terbutryn whereas the toxicity on bacteria and daphnids is caused by DCOIT and OIT. The results thus indicated that other components in the render did not add to the toxicity of the individual biocides. Overall, the approach combining a standard leaching test with standard bioassays is very promising to evaluate the ecotoxicity of biocides leached out from façade renders.

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Abstracts-Poster In vitro bioassays are increasingly used to assess estrogenic activity of environmental water samples, and have been suggested as suitable tools for monitoring estrogenic contamination of surface waters. Such assays are of particular use as they measure the overall estrogenic activity of a sample, including the potent steroids 17β-estradiol (E2) and 17α-ethinyl estradiol (EE2). Monitoring of E2 and EE2 under the WFD watch-list mechanism is currently an analytical challenge as proposed annual average Environmental Quality Standards (AA-EQS) of 400 and 35 pg/L, respectively are below limits of quantification for most routine analytical methods. Sensitive in vitro assays could circumvent current detection problems by measuring the overall estrogenic activity of all (xeno)estrogens present in an environmental sample.

P5. Effect-based tools for monitoring (xeno)estrogens in surface waters: Variability and reproducibility of sample preparation and 5 different in vitro assays
It has been shown, however, that different in vitro assays lead to different E2-equivalent (EEQ) concentration for the same sample. Reasons for these differences are known, but it remains unclear how to use and interpret bioassay results. The aims of this study were (1) to compare the variability and reproducibility of EEQs measured in five in vitro assays (YES, ER-Calux, MELN, T47D-KBluc and GeneBlazER), including sample preparation (SPE) and, to (2) evaluate their applicability as effect-based tools for environmental monitoring.
Our data shows that ERTAs are comparable to chemical measurements regarding variability and repeatability of the derived EEQ concentrations. In the different ER-TAs overall variability ranged between 6 and 17 % for highly polluted samples and, 7 to 27 % for low polluted samples spiked with a concentration of (xeno-)estrogens below the AA-EQS for E2 of 0.04 ng/L. In all cases, recoveries were between 72 and 125 %.
ERTAs are promising tools to screen for estrogenic activity in environmental water samples. Within the watch list mechanism of the WFD such a screening step, preceding the analytical monitoring will reduce monitoring costs and provide valuable information on water quality.

Simon Eszter, Schweizerisches Zentrum für Angewandte Oekotoxicologie EA-WAG-EPFL, Dübendorf, Schweiz
Petra Kunz, Cornelia Kienle, Inge Werner, Etienne Vermeirssen eszter.simon@oekotoxzentrum.ch In vitro assays used in ecotoxicology typically generate sigmoidal dose-response curves when a reference compound is applied in increasing concentration. These dose-response curves are used to derive equivalent concentrations for environmental samples. However, curves generated for environmental samples are often not parallel to that of the reference, or do not achieve minima or maxima values that are similar to the reference. This may be due to low expected activity of the sample, sample solubility problems or cytotoxicity. Low activity may be expected for surface and/or drinking waters. When this occurs, the type of data analysis conducted will influence the equivalent concentrations derived. This makes the comparison of studies conducted in different laboratories challenging. Furthermore, there is a need for harmonized data analysis to translate bioassay data from science to regulation.
In this study, data of a previous study were re-analyzed. The original data, which compared 17β-estradiol equivalents (EEQs) of reconstituted water samples and extracts assessed by five commonly used in vitro bioassays, were calculated by interpolating the response of the sample into the dose-response curve of the reference compound (17β-estradiol). Data points from the lower linear region of the sample dose-response curve, but still above the assay limit of detection (LOD), were considered for EEQ calculations.
We now used the raw data and determined EEQs using the "PC10 approach". First, all data were normalized, where 0% refers to the response in the solvent control and 100% is the maximum response fitted for the reference dose-response curve. Second, the 10% effect level of the sample was interpolated from the reference dose-response curve.
Results did not differ much between the two data analysis strategies as could be expectedin both cases data points from the lower part of the sample dose-response curves were evaluated. One additional influencing factor on the EEQ concentration derivation might be the fact that data were generated from mixtures of standard compounds and not from more complex environmental samples. However, it still has to be evaluated if this played a role in the outcome. To assess this further, additional calculations and graphical examples with real-life water samples will be shown. The "PC10 strategy" appears to circumvent the problems described above regarding the derivation of equivalent concentrations, and to be a more robust and objective method for in vitro test data analysis.

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Abstracts-Poster Currently, more than 40 internationally agreed (i.e. ISO or OECD) test methods are available for assessing soil quality or effects of chemicals on the soil fauna. Among the invertebrates used to identify potentially toxic chemicals in soil, the compost worm Eisenia fetida is certainly the oldest representative, as described in the OECD guideline 222 on earthworm acute toxicity from 1984. Since then, the number of standardised methods using soil organisms from different trophic levels or evaluating diverse endpoints have increased steadily. Within the aim of developing an integrated approach for the evaluation of Swiss soil quality, the Ecotox Centre is building a tool box based on a battery of practice-oriented toxicity tests. We will present suitable and relevant ISO or OECD ecotoxicological methods that have already been considered and applied in various projects. We will also present promising tools that are under development or that are considered for standardisation. Sediments are an ecologically important compartment of surface waters. According to the Swiss Water Protection Ordinance [1], sediments must not accumulate persistent pollutants to ensure the protection of aquatic life. Although a national program for the monitoring of sediment quality such as the one implemented for soils (NABO) is absent, existing data illustrate that sediment contamination is present in Switzerland and there are cases where it is of concern for the health of aquatic ecosystems. Despite this, to date no harmonised guidelines/methods or quality standards are available for sediment-quality monitoring.
According to a questionnaire sent to cantonal agencies, the availability of adequate sediment quality guidelines for selected chemicals to classify in situ sediments according to their ecotoxicological risk is a top need [2]. Of second priority is the harmonisation of sampling strategies, including the preparation of samples for further analyses.
In response to the needs of cantons and other stakeholders, the Ecotox Centre together with Eawag and Bafu, started working on a new module "sediment" within the framework of the Modular Stepwise Procedure ("MSK") used in Switzerland for surface water quality monitoring. The module is conceived to aid cantonal and private agencies in conducting sediment quality assessments in a harmonised regulatory framework and support the cantonal water protection institutions to fulfil their obligations regarding Swiss water protection laws. The module "sediment" is planned to complement existing MSK modules and thereby to achieve a more holistic assessment of Swiss surface waters by incorporating the sediment compartment.
The first phase of the project deals with the development of a sediment assessment system based on the chemical status and will address the two top priorities for cantons: 1) a harmonised protocol for sediment sampling and pre-treatment and 2) numerical sediment quality guidelines for selected contaminants and a related quality classification system for selected compounds. The output should be a technical guidance document with a validated and calibrated methodology ready for use by cantonal and private labs.  (1) (1) Oekotoxzentrum Eawag-EPFL, Switzerland (2)  The Venoge is a small river flowing into the Lake Geneva, the largest water body of Switzerland. Previous monitoring campaigns have shown increased concentrations of PCBs in fishes, which were reported to exceed maximal levels permitted by the European Union for human consumption. The quality of the surface waters of the river are well characterized, both in terms of chemical contamination and benthic community structure. However, no information of sediment quality was available so far. We have used an integrated methodology that includes sediment physico-chemical measurements, the ecotoxicological effects of collected sediments using a battery of sediment toxicity tests, and the bioaccumulation of contaminants to benthic invertebrates to assess the contribution of sediments to the overall quality of the water body.

P10. Bioavailability and toxicity of sediment-bound contaminants (PCBs and metals) using an integrative approach: case study of the
Sediments were collected at several sampling sites along the Venoge and they were analyzed for PCBs and metals concentrations as well as other ancillary parameters important in determining contaminant bioavailability. The battery of tests used for the characterization of the ecotoxicological properties of sediments included several standard sediment-contact tests using different species and endpoints: the growth inhibition test using the aquatic macrophyte Myriophyllum aquaticum (ISO 16191); the growth and mortality test using the ostracod Heterocypris incongruens (ISO 14371); the emergence test using midge larvae of the species Chironomus riparius (AFNOR 90-339) and the survival and growth test using the amphipod Hyalella azteca (ISO 16303). Bioaccumulation was also assessed in midge larvae under laboratory and field conditions.
The chemical characterization classified the sediments as having intermediate levels of contamination, with concentrations increasing at downstream sampling sites. The toxicity tests showed variable toxicity depending on the test organism and the test endpoint, although the highest toxicity levels were also observed at the site closer to the river mouth. Bioaccumulated concentrations in midge larvae showed direct uptake of PCBs from sediments to this benthic invertebrate. The results obtained in this case study are integrated to assess whether sediments are contributing to the impairment of the beneficial uses of this aquatic ecosystem and identify which tools from those included within the proposed approach provide useful information within a decision-making framework.

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Abstracts-Poster The rising amount of plastic waste being released to the aquatic environment is of great concern due to their diverse effects on living organisms. Especially multiwalled carbon nanotubes (MWCNT), which are contained in several plastic products and can be released to the aquatic environment in the process of weathering, may offer sorption sites for highly sorptive substances like triclocarban (TCC). As a consequence of sedimentation this TCC-MWCNTsorbate might be available to sediment dwelling organisms and have influence on the toxicity and bioaccumulation. As TCC is exclusively employed as a bacteriostat in bar soaps, the major route for TCC disposal is through domestic sewage and it has already been detected in streams and municipal biosolids as well as in sediments.

P11. The influence of multiwalled carbon nanotubes on the toxicity and bioaccumulation of triclocarban in Lumbriculus variegatus
This study focuses on the acute toxicity of TCC in the presence of MWCNT on Lumbriculus variegatus. The toxicity tests (14 days) follow the OECD 225 and take five concentration (0.5 mg/kg dw -8 mg/kg dw and 0.4 mg/kg dw -2 mg/kg dw) of TCC into account while the concentration of MWCNT is fixed (1 mg/l). The toxicity of TCC itself is tested as a reference to illustrate the effect of MWCNT on the worms. First results show a NOEC lower than 0,5 mg/kg dw. Subsequently, a bioaccumulation study shows the ingestion and metabolism of 14C-TCC in the presence of MWCNT in Lumbriculus variegatus by analysing the radioactivity in the worm tissue at different time points during a 14-day exposition. These studies are accompanied by sorption studies according to the OECD 106 to determine the distribution coefficient (Kd) and sorption isotherm as means to explain the effect of MWCNT as a sorption site for TCC in the sediment water system. For all studies quartz sand is used as sediment to illustrate the effect of MWCT as the main sorbent.
It is to be expected that TCC adsorbs stronger to MWCNT containing sediment. Hence, the distribution coefficient is higher compared to a scenario without MWCNT. As a consequence TCC might be more bioavailable for Lumbriculus variegatus and finally leads to a higher bioaccumulation and possibly a higher toxicity. Aquatic primary producers, such as phytoplankton and macrophytes, are key players of the biogeochemical cycle of mercury (Hg) in the aquatic environment. Indeed, the Hg bioaccumulation step from water to primary producers has been shown to be the largest increase of Hg concentrations in aquatic ecosystems reaching 104-fold and greater. It is therefore of the upmost importance to understand uptake and effects of Hg in primary producers. The effects of Hg on aquatic primary producers were only sparsely investigated until now. While it has been shown that Hg affects photosynthesis and the activity of oxidative stress enzymes in microalgae, its effects were less studied in macrophytes, especially concerning MeHg. Moreover most studies were conducted at high concentrations only and were thus not representative of environmental conditions. Using a transcriptomic approach (RNA-Seq), we therefore studied the effects at the molecular level of MeHg (5 x10 -11 , 5 x10 -10 , 5 x10 -9 and 5 x10 -8 M), in the microalga Chlamydomonas reinhardtii and the macrophyte Elodea nuttallii, adapting bioinformatics analyses to the available genomic information for the studied species. Strong response of the transcripts involved in photosynthesis was observed at all MeHg concentrations in the alga, but only at the two highest concentrations in the macrophyte. Concomitantly, MeHg affected genes involved in carbohydrates, amino acids and lipids metabolisms, as well as the expression of many transcripts coding for transporters. In fact, while ABC and calcium transporters were significantly affected by MeHg in C. reinhardtii, ATPases and ammonium transport were disregulated in E. nuttallii. Finally, metal transporters, e.g. zinc transporters, were significantly affected in both species. The transcriptome response to MeHg in the two representative aquatic primary producers was congruent with their morphological, physiological and sensitivity differences.

P15. Lemna sp. and Daphnia magna in pulsed dose test designs relating to the EFSA guidance document on tiered risk assessment Eser Sabine, Eurofins Agroscience Services EcoChem GmbH
Claudia Zawadsky, Silke Falk, Guido Gonsior, Nathalie Schwalbach

SabineEser@eurofins.com
In the latest guidance document of the European Food Safety Authority (EFSA Journal 2013;11 (7):3290) tiered risk assessment with aquatic organisms for plant protection products is outlined. In edge-of field surface waters time-variable exposure towards plant protection products is common. Therefore it is stated that for risk assessment the predicted exposure regimes may be simulated by pulsed dose tests instead of performing constant exposure as in standardised lower tier tests. To reflect the actual exposure scenario the number and spacing of pulses (toxicological (in)dependence of repeated pulse) is of high importance for an appropriate risk assessment. The algal growth inhibition test according to OECD 201 is routinely used to assess the toxicity of substances as pesticides, biocides etc. on algae. This standard test design with a static exposure period of three days simulates a simple scenario assuming a constant exposure in a static water body. The exposure of organisms towards agrochemicals in the aquatic environment on the other hand usually follows more complex patterns. Generally, agrochemicals are applied seasonally and the entry of them into surface waters via spray drift, run off or drainage therefore is typically time-variable. According to the EFSA "Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge-of-field surface waters" (2013) a more realistic fate can be taken into account during a higher-tier risk assessment of plant protection products. Here we present a single species algal flow-through system which offers the possibility to test the effects of time-variable, e.g. pulse-dosed, concentrations to algal populations including the potential to prove population recovery during a test period of several weeks to months. Thus, the algal flow-through system is a helpful tool to improve the environmental risk assessment of substances like herbicides towards algae by testing more realistic time-variable concentrations. Enhancement of naturally occurring background concentrations of metals and metal compounds in the environment from anthropogenic sources may lead to raising risks for potentially exposed organisms. This concern is addressed by the European REACH regulation in the methodology described by ECHA in a specific technical guidance document for the chemical safety assessment for metals and metal compounds. A considerable number of metals, among them various lead as well as chromium compounds, have already been evaluated under European regulatory context. Therefore, EU Risk Assessment Reports and REACH dossiers are available, which served as a basis for the derivation of Predicted No Effect Concentrations (PNEC) for relevant environmental compartments. However, as no experimental effect data for lead chromate itself has been published so far, short-term ecotoxicity studies on the freshwater algae Pseudokirchneriella subcapitata and invertebrate Daphnia magna were conducted. Results from these studies were used to assess whether read-across concepts as seen in many REACH dossiers on different chemical compounds, containing the same metal, can be regarded as appropriate.

P17. Lead cromate in aquatic compartments -Acute ecotoxic effects on Algae and Daphnia and Derivation of Predicted No Effect Concentrations (PNEC) in the Context of REACH
Due to its very low water solubility, maximum soluble test concentrations of lead chromate had to be prepared according to the principal of "Water Accommodated Fraction" (according to OECD technical guidance) and diluted to final test concentrations.
Lead chromate caused a concentration-dependent inhibition of algal growth with a 72 h ErC50 (specific growth rate) and EyC50 (yield) of 3012 µg and 1291 µg PbCrO4/L, respectively, with NOECs of 528 µg PbCrO4/L for both parameters. The maximum achievable PbCrO4 concentration in the daphnia test (median 167 µg/L) had no effect on immobilisation.
Experimental results correlate very well with other available effect data on the same trophic levels and confirm the assumption, that the ecotoxicity of the tested metal compounds is predominantly caused by the cation. The occurrence of genotoxic compounds in aquatic systems can present a serious threat for humans and aquatic organisms. Therefore unexplained genotoxic effects caused by environmental samples present a challenge for Effect Directed Analysis (EDA). As a result, biotesting strategies for genotoxicity assessment can highly benefit future EDA studies. Currently, different bioassays are available to measure and assess genotoxicity. Among eukaryotic systems, the micronucleus test (MN) is a robust method previously applied to different in vitro and in vivo experimental models. Unfortunately the MN is a work-intensive and time-consuming method, characteristics which reduce its applicability in EDA. At the same time, the p53-CALUX assay is a recently developed reporter gene cell-based bioassay that presents great potential for high-throughput screening. Even if previous studies have demonstrated a correlation between the induction of p53 and micronucleus formation, the p53-CALUX has been only limited applied so far.
This study aimed to advance small-scale genotoxicity bioassays and develop a biotesting strategy for genotoxicity assessment in EDA. The micronucleus test was established using two new experimental models: the ZFL zebrafish liver cell line and zebrafish early larvae. Also, the p53-CALUX assay was established in our laboratory. The bioassays were applied to investigate the toxicity of selected chemicals, including the environmental contaminants 3nitrobenzanthrone, 1-nitropyrene and benzo[a]pyrene; and the positive control chemicals 4nitroquinoline 1-oxide, cyclophosphamide and actinomycin D. There was also investigation of non-specific toxicity, through the MTT assay for the cell-based systems, and by the assessment of lethal and sublethal morphological endpoints in the zebrafish.
Results from the cell-based bioassays demonstrate the importance of determining the levels of non-specific toxicity that can occur simultaneously to the genotoxicity investigation. For instance, the peaks of p53 induction were observed shortly before or concurrently with reduced cell-viability effects. At the same time, high cytotoxicity levels should be avoided, as those can cause general cell stress that result in p53 induction or even micronucleus formation. Similar approach was followed to investigate MN on the organism level. The levels of non-specific toxicity were considered during the selection of exposure concentrations and also for the interpretation of results, in order to minimize the occurrence of false positive or false negative results. A vast diversity of human and veterinary pharmaceuticals is frequently detected in aquatic ecosys-tems. However, effects of these substances in biota are far from being understood.
Since the principle of pharmacovigilance demands the examination of environmental effects, it is crucial to develop new, effect-based strategies for the monitoring of pharmaceuticals.
Within the framework of the project 'EffPharm', we conducted a survey of published literature (2011 to 2013) to gain an overview which pharmaceutical groups appear to be of highest relevance for biota, and which organism groups and effect endpoints react most sensitively to pharmaceuticals. A data-base was created and the studies were evaluated with respect to the reported lowest observed effect concentrations (LOECs), which were subsequently compared to measured environmental concentra-tions (MECs) in surface waters. Additionally, we investigated the reliability of studies reporting LOECs in close range to MECs.
Overall, 452 studies were examined, of which 232 directly investigated effects of pharmaceuticals. The most frequently studied organism group was fish, with Danio rerio being the most commonly used species, followed by molluscs. It was shown that studies on effects of pharmaceuticals are conducted with a huge variety of species. However, only few of them are investigated in more than one study and studies rarely apply native species of high ecological relevance in Central Europe. Considering relevant endpoints, behaviour, vitellogenin synthesis, growth, reproduction and histopathological changes were among the most sensitive responses. Based on the information extracted from these studies, the analgesic diclofenac, the β-blocker propranolol, the lipid regulator gemfibrozil and the antibiotics erythromycin and sulfamethoxazole were identified as environmentally most relevant pharmaceuticals. Unfortunately, the evaluation also showed that only a minor part of the investigated publications can be considered as fully reliable; most studies included at least some minor shortcomings, e.g. the lack of chemical analyses of exposure concentrations. Furthermore, there still appears to be a huge knowledge gap considering mixture and sediment toxicity. The population relevance of many observed effects remains unclear.
For further monitoring strategies we propose a mode of action-driven approach specific for substance classes rather than tests on prioritized substances.

Schmieg Hannah, Universität Tübingen
Simon Schwarz, Marco Scheurer, Heinz R. Köhler, Rita Triebskorn hannah.schmieg@student.uni-tuebingen.de The discharge of human and veterinary pharmaceuticals into surface waters via wastewater treat-ment plants is a growing problem in Central European countries. Considering demographic changes, the consumption and environmental concentration of pharmaceuticals used for treating age-related diseases are known to increase. However, despite the frequent detection of various substances in aquatic ecosystems, knowledge on their effects in biota is still scarce. Available data are based on standard biotests with model test organisms which often lack ecological relevance. One of the most frequently used pharmaceuticals and, hence, also frequently detected in surface waters, is the beta-blocker metoprolol. However, only very few effect studies are available. Therefore, further information on the effects of metoprolol on aquatic ecosystems is of particular interest and importance.
Our study investigated the effects of metoprolol on the health status and on the embryonic devel-opment of brown trout, Salmo trutta f. fario, a species of high ecological relevance for Central Eu-rope. The applied concentrations were 0.1, 1, 10, 100, and 1000 µg/L metoprolol, thus including sev-eral concentrations in ranges reported for German surface waters.
Juvenile fish (six month post hatch) were exposed for a time period of 28 days. Besides biometric measurements and mortality, the level of the stress protein Hsp70 was measured as a general marker of proteotoxicity. Furthermore, histology of liver, kidney, gill, and heart was assessed reflecting the overall health condition of the trout. The exposure of trout eggs/embryos was based on OECD 212. Recorded endpoints in these tests included mortality, time until eyes were developed, time to hatch, number of hatched larvae and number of healthy larvae at the end of the test. In addition, the degree of lipid peroxidation in trout hatchlings was determined to assess oxidative stress.
The analysis showed no significant proteotoxic, embryotoxic or hepatotoxic effects. Further histological and biochemical analyses will complement the study.
Overall, our study aims at providing further information on the effects of environmentally relevant concentrations of a frequently used pharmaceutical in a species of high ecological relevance in Ger-many and adjacent countries.

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Abstracts-Poster The protection of freshwater ecosystems is one of today's greatest environmental challenges and therefore, their pollution is an issue of emerging concern. One part of the EU-funded SOLUTIONS project is a case study of River Danube in Novi Sad, Serbia, aiming to investigate how the discharge of untreated wastewater in local water bodies affects the river ecosystem. For adequate water quality assessment and prioritization of pollutants it is important to know which substances are present and which should be particularly monitored. In applying an effect-directed analysis (EDA) the intention is to analyze both the effects occurring in exposed fish embryos (as an alternative to animal tests with fish) and the substances which are responsible for the observed effects. In this study, we have developed a targeted proteomic approach to characterize the expression of glutathione-S-transferases, a group of phase II enzymes, during the zebrafish development. Selected members of the family are monitored in zebrafish embryos by mass spectrometry on the basis of proteotypic peptides and peptides characteristic for the enzyme groups of interest. The results collected in this study will help to establish methods for the detection of further enzymes involved in the phase I and phase II metabolism and fill some of the existing knowledge gaps regarding the comparability of metabolic capacity of fish at different life stages.

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Abstracts-Poster P25. Cell -type specific arylhydrocarbon (AhR) receptor signaling in liver and immune cells of rainbow trout. The cytosolic transcription factor aryl hydrocarbon receptor (AhR) senses small chemical molecules including important environmental contaminants, such as dioxins, polychlorinated biphenyls and polyaromatic hydrocarbons. Upon activation, the AhR induces via the dioxinresponse element to gene transcriptional changes, which are cell-specific and associate with cell-specific toxicity. Hallmarks of AhR-mediated toxicity in vertebrates are hepatotoxicity and immunosuppression. Here, we used primary cultures of rainbow trout immune cells and liver cells in combination with transcriptomics to examine cell-specific differences in the response to toxicant-induced AhR activation. Immune cells were isolated from head kidney and spleen by mechanical disaggregation, and hepatocytes were isolated from the liver by collagenase perfusion The cells were exposed to equipotent concentrations of the AhR ligand, benzo(a)pyrene (BaP). Global gene expression analysis showed that in total, 672 genes were regulated in liver cells, 134 in head kidney cells and 408 in spleen cells. Among the genes that were commonly upregulated in liver, head kidney and spleen, were CYP1A1, CYP1A3 and sulfotransferase. GO-term enrichment analysis of the regulated genes revealed an cellspecific response, with liver cells showing alterations particularly in pathways related to biosynthesis metabolism whereas immune-and homeostasis-related pathways were most affected in head kidney and spleen cells. In conclusion, the findings point to pronounced cell type-specific effects of AhR activation and provide a basis to assess organ-specific toxicities of environmental contaminants. Environmental contaminants with endocrine disrupting properties are not only able to disrupt the reproductive system of fish, but also their thyroid system. Comparably little is known about the developmental, physiological and behavioral consequences of thyroid disruption in fish. As the thyroid system plays an important role in the development of craniofacial structures and the eyes, its environmentally induced disruption can impact important fitnessrelated parameters such as metamorphosis, behavior or visual capacities of the larvae. The present study aims to investigate the relation between initiating molecular events of thyroid disruption and morphological and physiological changes of the embryonic development of zebrafish (Danio rerio) with focus on the eye development and function. Two modes of action were studied: interference with thyroid hormone synthesis with the pharmaceutical Propylthiouracil (PTU), and binding to thyroid hormone receptors with the flame retardant Tetrabromobisphenol A (TBBPA). Changes in gene-expression were analyzed with qRT-PCR and visualized with whole mount in situ hybridization. The influence on visual capacities of the embryos was investigated by measurement of the optokinetic response (OKR). The results provide initial insight if and how chemical interactions with molecular events in the thyroid axis of zebrafish translate into morphological and physiological alterations of the developing embryos. At present, little is known about the presence, expression and function of biological defense systems in early development stages of teleost fish. Here we analyzed the expression of uptake transporters, phase I and phase II enzymes and ABC transporters during development of eleu-thero-embryos from 1 to 20 days post hatching (dph). The aim was to obtain an overview on the mRNA profiles in different body parts of eleuthero-embryos and to analyze the function of ABC-transporters. The transcript profiles of eight ABC transporter genes (abcb1a, abcb1b, abcc1, abcc2, abcc3, abcc4, abcc5, abccg2), two phase I (cyp1a, cyp3a), three phase II (gstp, putative ugt1, putative ugt2), two uptake transporters (oatp1d, putative oatp2) and an SLC47 efflux transporter (mate7) are described. Transcripts of most phase I and II enzymes and ABC trans-porters showed a variable abundance in different body parts during development. The function of ABC-transporters was determined by use of inhibitor assays. MK571 inhibited the uptake of rhodamine B by the eleuthero-embryos at 1 and 10 dph, while cyclosporin A and reversin205 had little effects. Clotrimazole led to inhibition of rhodamine B uptake at all development stages and in all body parts, whereas clofibric acid showed no effect. In addition, clotrimazole led to changes in some transcript levels. The expression of uptake and efflux transporters, xenobiotic metabolizing enzymes and the functionality of ABC transporters suggest the presence of a defense system in eleutheroembryos of rainbow trout. The standard test for regulatory purposes to determine bioaccumulation of xenobiotics in fish is the OECD TG 305, an in-vivo test which uses a high number of animals (> 100). Recently, in-vitro metabolism assays using isolated hepatocytes from fish have been introduced as possible alternative to the in-vivo bioaccumulation test. Currently, work is under way to demonstrate the reproducibility of the method supporting a formal validation. A drawback, however, is that the available in-vitro protocols have been developed exclusively for rainbow trout (Oncorhynchus mykiss), but not for the other fish species commonly used under TG 305 such as common carp (Cyprinus carpio). In order to overcome this limitation and to foster the acceptance of the in-vitro method, it must be demonstrated that the protocol is not restricted to one specific fish species. The aim of this study was to evaluate if the existing invitro methodology for determining xenobiotic clearance in isolated hepatocytes of rainbow trout can be adapted to carp hepatocytes. In a first step, a protocol for isolating carp hepatocytes based on a two-step collagenase-perfusion technique was developed, leading to high cell yield and good cell quality. In a next step, existing protocols for measuring xenobiotic clearance were applied to freshly isolated hepatocytes from trout and carp. As model substances, benzo[a]pyrene (BaP) and methoxychlor (MCX) were used. Incubation temperature for carp hepatocytes was 20°C, while it was 15°C for trout hepatocytes. Irrespective of the higher incubation temperature in the carp assay, xenobiotic clearance rates tended to be lower with carp hepatocytes than with trout hepatocytes. The results from this study demonstrate that the in-vitro metabolism assay protocol developed for the cold water species rainbow trout in principal is transferable to other species. What remains to be evaluated is whether the observed differences of the in vitro metabolic rates between carp and trout hepatocytes are able to predict species differences of in vivo xenobiotic metabolism. The rainbow trout (Oncorhynchus mykiss) gill cell line, RTgill-W1, has been tested to predict fish (in vivo) acute toxicity, hence, an animal alternative to tests used for chemical risk assessment. In a previous study, 34 organic industrial chemicals (selected using pre-defined criteria), were tested and compared to the acute toxicity reported in the US EPA fathead minnow data base. The majority of data was within a 10-fold range versus acute fish lethality when taking into account bioavailable exposure concentrations. Moreover, the outcome of the cell line assay compared very well to results obtained in the zebrafish embryo toxicity test (FET), which has meanwhile been accepted as the OECD test guideline 236. These findings provided the impetus to initiate the RTgill-W1 cell line assay as a potential animal replacement method to the same level of international acceptance. Through support of CEFIC-LRI and UK NC3Rs, an Eawag-led round-robin test, involving six industrial and academic research laboratories from Europe and the USA was conducted. The overall goal was to test the robustness of the established methodology. In particular, the transferability of the RTgill-W1 cell line assay and the intra-and inter-laboratory reproducibility was evaluated.

P28. Comparative assessment of xenobiotic clearance in primary
Seven laboratories provided data for the round-robin testing, either for the cell line assays and/or analyses of chemical concentrations. Chemical selection and quantitative analysis as well as conductance of the cell line assay followed criteria and protocols used in the initial study. Experiments with the cell line assay include a minimum of three biological replicates (cells from different passages) with three technical replicates in each test run. Results of cell viability measurements are based on verified exposure concentrations. Indeed, the RTgill-W1 cell line assay procedure was transferred successfully to each of the participating laboratories. Improvements to the original standard protocols were implemented based on the suggestions provided by the participants -leading to further simplification.
Data was analysed using diverse statistical methods with a specific focus on inter-and intralaboratory variability, providing a solid basis that will likely establish this method as an animal-free alternative to the fish acute toxicity test. In the Tier I approach, the risk of pesticides to bees is usually assessed through oral and contact exposure. With application of the substance on the thorax representing all possible contact exposure scenarios, routes of entry other than the thorax are not considered in risk assessment. To present, only one study has dealt with the uptake of insecticides through the wings in the honey bee Apis mellifera. In our study we aim to investigate this new route of exposure via wing contact with the solitary bee Osmia bicornis. An LD50 value of the active substance dimethoate will be established for Osmia bicornis males by applying the substance on the rear part of the wings that is not in direct contact with the abdomen. In addition, a standard thorax contact test will be set up. A comparison of acute thorax and wing contact LD50 values will determine if contact exposure through the wings is a relevant exposure scenario that should be considered in pollinator risk assessment.

P39. Nesting success of Osmia bicornis females in landscapes with varying levels of food abundance Wollmann Claudia, Universität Landau
Eva Eschenbach, Philipp Uhl, Peter Stahlschmidt, Carsten Brühl woll7400@uni-landau.de Pollination is a key ecosystem service in decline due to a number of factors of which habitat decline and fragmentation pose one of the major problems. Wild pollinators like the red mason bee Osmia bicornis rely on suitable habitats as nesting and foraging sites. Existing data on the foraging range of Osmia bicornis females is not conclusive and it is unclear if the females are able to explore alternative food sources when they are scarce around the habitat site. In this study we aim to investigate how food availability influences the attractiveness of nesting aids to Osmia bicornis and the subsequent brood development. In a field trial, nesting aids containing female and male cocoons are placed in three different types of landscapes that provide varying levels of food abundance. Pollen samples from the nesting aids used for the provision of the larvae are analysed for their origin. The pollen is inspected to determine if low food availability in the field provided as habitat results in an adaptation of their foraging behaviour and in an increased flight range. First inspections of the collected pollen indicate that Osmia bicornis females are indeed able to adapt their foraging behaviour in landscapes with scarce food resources and that abundance of Osmia bicornis is not influenced by the degree of habitat isolation.
Ferrari (1)  Viticulture still relies on copper based fungicides applied against Downy Mildew. Copper accumulates in soil if used continuously. In this study we investigated two different vineyards, the first one was 100 years under cultivation and the second one was 15 years under cultivation, in terms of metal concentration and soil functional activity. Soil samples from the two sites were taken in two seasons (2011 and 2014) for soil moisture content and copper, lead as well as zinc content analysis. Additionally the soil functional activity was assessed by using the bait-lamina method, measuring soil invertebrate feeding activity.
The total copper content of the two sites differed by a factor of 8, due to high copper contents for the site which was 100 years under cultivation. The feeding activity at this site was lower in both seasons compared to the site which was 15 years under cultivation. The role of copper compared to environmental and management related factors influencing the feeding activity of soil organisms is discussed.

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Abstracts-Poster Among the tools used to assess soil quality, the bait lamina test is a simple, fast and inexpensive method to measure the functional aspect of the soil ecosystem. The feeding activity (biological activity) of soil invertebrates is assessed in situ at the community level by measuring the disappearance of a series of organic bait ("bait") embedded in small PVC sticks inserted vertically into the soil. The method allows studying the pollution gradients on the field, but also to assess the impact of pesticide applications on the biological activity of the soil. It can also be used as a screening method for a first characterization of the sites and their biomonitoring. A draft of an international standard (ISO / DIS 18311) is available since 2014.
Given the ecological relevance of the biological response assessed in situ by this method, we investigated the usefullness of this approach in a priori risk assessment of substances in the laboratory. The objective was thus to adapt the bait lamina method for measuring the feeding activity of the species Eisenia andrei in a simple test under laboratory condition. Briefly, 5 bait-lamina sticks are planted in each 500-mL replicate containing the soil contaminated to the desired concentration of test substance and 5 E. andrei. After 48-h of exposure, the percentage of bait cosumed by earthworms is calculated for each of the tested concentrations and the EC50 is determined. Our results showed a clear concentration-response relationship. Moreover, in order to give an insight of the sensitivity, this method was compared in parallel to the standardized avoidance test (ISO 11268-2) and the reproduction test (ISO 17512-1). Preliminary results show similar sensitivity of the Bait Lamina feeding test and the avoidance test. Concerning the reproduction test, it appears less sensitive.
The use of such a relatively simple laboratory method to assess feeding activity of earthworms will allow the rapid screening of soil samples for sublethal effects due to the impact of chemicals, and an assessment of the functional aspect of soils under standardized conditions. This approach shows promise for the a priori ecological risk assessment of chemicals.

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Abstracts-Poster The goal of our study was to determine the suitability of passive sampling for a comprehensive screening of a very large number of polar to semi-polar micropollutants that are occurring in streams and rivers. A field study was carried out where 45 Chemcatchers® were deployed, for two week periods, in five agriculturally and urban influenced Swiss rivers from March to July 2012. During the same time periods, two-week time-proportional composite water samples were taken for comparison. The investigated 322 substances -pesticides, pharmaceuticals, industrial chemicals and their transformation products with divers physicochemical properties (logKow -3 to 5, neutral, anionic, cationic, and zwitterionic species)were analysed by liquid-chromatography high-resolution tandem mass spectrometry. Results showed that Chemcatchers® are perfectly suited for the qualitative screening of polar micropollutants. The number of detected substances was similar for both sampling methods (204 for passive samples vs. 207 for composite water samples), limits of quantification were comparable (median: 1.3 ng/L vs. 1.6 ng/L), and the handling of Chemcatchers® in the field and laboratory is fast and easy. The fact that so many different substances accumulate on the sampler also opens the door for a comprehensive screening for suspects or unknowns. In-situ calibrated sampling rates (field Rs) could be determined for 88 compounds, i.e. where a good regression was obtained between water concentration vs. sampled mass on passive sampler disk. It could be clearly shown that substances with moderately fluctuating concentrations such as pharmaceuticals showed better correlations than substances with highly fluctuating concentrations such as pesticides (R2 > 0.75 for 93% and 60% of the investigated substances, respectively). It was observed that ionic species had significantly lower field Rs than neutral species. However, a correlation between determined field Rs and hydrophobicity (logDow) could only predict Rs with large uncertainties. We conclude that substances with relatively constant concentrations can be quantified accurately in the field by passive sampling. To do so, substance-specific Rs for these compounds need to be determined. For that purpose, in-situ calibration is a very robust method and the determined Rs can be used in future monitoring studies in rivers with similar environmental conditions. In dieser Studie wurde die Dechlorierung von PCB mithilfe von chemisch synthetisierten Pd(0)-Nanopartikeln und ausgewählten PCB-Kongeneren als Edukt untersucht. Die Versuche wurden unter anoxischen Bedingungen in Mikroreaktionssystemen (10mL) durchgeführt, H2 diente dabei als Elektronendonator. Die Analyten wurden mittels SPME-GC/MS detektiert. Das Dehalogenierungspotential der Pd(0)-Nanopartikel wurde in Anwesenheit verschiedener Pd(0)-Konzentrationen (0,25 -10 mg L -1 ) quantifziert.
Die hier verwendete Methode eignet sich gut, um die nanoPd (0)  In 2000 the European Waterframework Directive (WFD 2000/06/EC) was remitted to standardize the monitoring of aquatic ecosystems and ground waters within the EU. Furthermore, the improvement of water quality and the sustainable usage of water are main objectives of the WFD. Within the scope of the project "Traceability for mercury measurements" of the European Metrology Research Programme (EMRP) quantitative analytical methods for the priority substance mercury will be developed.
Inorganic Mercury and its methylated chemical forms are highly toxic to human, animal and environmental health. Its high affinity to accumulate in terrestrial and aquatic biosystems makes it a particularly insidious threat to environmental sustainability. Due their long lifetimes and the ability to be transported in air over long distances lead to an ubiquitous occurrence in all environmental compartments and make them to pollutants of global concern. The assessment of the ongoing effect of mercury on humans and the environment is critically dependent on reliable accurate measurements to assess concentrations and trends. This is challenging because of the various chemical forms of mercury and its presence in a number of different matrices.
One of the main aims of the project is: • To develop primary measurement procedures for mercury speciation in water and biota in order to improve mercury monitoring through the aquatic ecosystems and to support European legislation. This will include the evaluation of transformation artefacts associated with sample collection and preparation, in order to minimise species conversion post-sampling.
The project scope will be presented. First results of mercury measurements in biota will be demonstrated. Therefore samples of the Environmental Specimen Bank from UBA are extracted and analyzed with GC-ICPMS. Quantification is carried out with isotope dilution.

164
Abstracts-Poster Surfactants are used in a wide range of products like household and industrial cleaning agents, personal care products, and pesticide formulations The extent of surfactant production and use is not without risk for the aquatic environment, previous work have shown they might be potential harmful to aquatic ecosystems. The objective of our study was to assess the occurrence of a wide range of surfactants in the river Holtemme in Saxony-Anhalt (Germany), which is affected by multiple stressors as a result of wastewater discharge and agricultural land use. In order to obtain a comprehensive surfactant distribution profile of selected river stretches, samples were taken from sediment, Cladophora algae and river water.
Extraction methods were individually selected and developed with regard to respective sample source. Water samples were taken in 20 mL test tubes and extracted using a QuEChERS approach consisting of a salt-assisted liquid-liquid extraction into acetonitrile, an evaporation of the acetonitrile phase and reconstitution in methanol. This novel method aimed at reducing compound losses due to surface adsorption. Sediment and Cladophora samples were lyophilized and a sequential extraction using pressuring liquid extraction combined with further clean-up steps (normal phase and liquid-liquid extraction) was developed. The cationic, nonionic, anionic and zwitterionic surfactants in all extracts are currently analyzed by liquid-chromatography coupled to high resolution mass spectrometry. It is now recognised that chemicals detected in the environment may act together and that mixture effects should be taken into account in ecological risk assessment. However, to date, very few approach were proposed to reach this goal. In ecotoxicology, mixture effects were largely influenced by toxicological theory. Basically, two models are used to assess the mixture effects: the concentration addition and the independent action model. Synergisms and antagonisms effects are generally neglected, as they are hard to predict. For ecological risk assessment, these two models can be combined either with the classical safety factor method or with the species sensitivity distribution curves. Such an approach is however poorly applied until now, mainly for two reasons: the lack of data needed (ecotoxicological data, mode of action of the chemicals), and the lack of validation of the approach.Indeed, mixture risk assessment predictions have rarely been confronted with biological changes observed in the environment. In this study, long-term monitoring of a European great lake, Lake Geneva, provides the opportunity to assess to what extent the predicted toxicity of herbicide mixtures explains the changes in the composition of the phytoplankton community next to other classical limnology parameters such as nutrients. To reach this goal, the gradient of the mixture toxicity of 14 herbicides regularly detected in the lake was calculated using concentration addition and response addition models. A temporal gradient of toxicity was observed which decreased from 2004 to 2009. Redundancy analysis and partial redundancy analysis showed that this gradient explains a significant portion of the variation in phytoplankton community composition with and without having removed the effect of all other covariables. Moreover, species that are significantly influenced, positively or negatively, by the decrease of toxicity in the lake over time are highlighted. It can be concluded that the herbicide mixture toxicity is one of the key parameters to explain phytoplankton changes in Lake Geneva.

P54. Aktives Monitoring zur Fischgesundheit in Fließgewässern am
P56. On the appropriateness of using the common mixture toxicity models CA and IA on species sensitivity distributions: a theoretical approach Chèvre Nathalie, Université de Lausanne Vincent Gregorio Marion Junghans nathalie.chevre@unil.ch Environmental species are not only exposed to single substances but typically to mixtures. Therefore it is of great importance to assess the ecological risk not only substance by substance but also for mixtures of compounds. Two models are generally used to predict mixture toxicity: the concentration addition (CA) (or dose addition) and the response addition (RA) (or independent action) models. Their adequacy to predict mixture toxicity of similarly acting compounds (CA) and dissimilarly acting compounds (RA) for single species was already shown during the last decades. To assess the risk of chemical mixtures to ecosystems, these two models have also been proposed to be applied directly on species sensitivity distribution (SSD) curves to derive a multi substances potentially affected fraction of species (msPAF). Usually, this is done in two steps: (i) the CA model is applied on individual SSDs of similarly acting compounds and then (ii) the RA model is applied on the predicted SSDs by CA between groups of similarly acting compound. However, as mentioned above the validity of mixture models were shown only for single species when applied on single dose-response curves and not on multiple species SSDs. For a validation of this approach, one should therefore first apply the mixture models for each species, then construct the mixture SSD to calculate the msPAF and compare it with a msPAF derived by applying the mixture models directly on the SSDs. This approach is however rarely done because the information on the whole dose-response curves of each single species for all substances is needed and this information is poorly available. In this study, we highlighted the difference between the two methodologies (SSD combination with CA/RA models or single species mixture assessment followed by SSD construction) to derive a msPAF. To compare the two methods we calculate msPAF with different cases, varying the EC50s and the slopes of the individual dose-response curves. The results show that the predictions with CA are quite similar between the two methods and small differences can be explained by the goodness of fit of SSDs and the species tolerance correlation among substances. However, risk underestimation are observed with large number of substances or with SSD built based on substances with flat dose-response curves. The application of RA may result in a differing msPAF between the two methods also when the individual dose-response curves are flat. Finally, we define cases in which the two methodologies give similar results and for which the use of CA and RA directly on SSDs to predict the risk of mixture compounds is appropriate.