En Suisse, le recours à des tests écotoxicologiques (bioessais) pour l'évaluation des atteintes à la qualité des eaux ou des sédiments ne sont pas prescrits par la législation, que ce soit pour la protection des eaux de surface ou dans le cadre de l'investigation des sites pollués. Pour ces derniers, selon l'ordonnance sur l'assainissement des sites pollués (OSites), l'évaluation du danger des substances polluantes est réalisée à l'aide d'analyses chimiques pour chaque polluant individuel. Les concentrations mesurées sont comparées à des valeurs limites établies sur la base de données de toxicologie humaine. Dans le cadre de l'estimation des atteintes aux écosystèmes, les tests écotoxicologiques peuvent toutefois constituer une méthode complémentaire pertinente. Ces derniers avaient été proposés dans une aide à l'exécution, désormais plus en vigueur, pour l'évaluation des lixiviats de sites pollués (par ex. sites contaminés et décharges). Cette aide à l'exécution recommandait l'utilisation d'une série de tests écotoxicologiques (sur des bactéries luminescentes, des algues et des crustacés) et, dans certains cas, des études complémentaires de génotoxicité ou de toxicité chronique. Malgré le retrait de l'aide à l'exécution, des tests écotoxicologiques ont continué et continuent d'être appliqués régulièrement dans des projets mandatés par des autorités cantonales ou communales. Les bioessais peuvent se montrer très intéressants, puisqu'ils tiennent compte de la mobilité, du mélange et de la biodisponibilité des substances chimiques et renseignent sur la dangerosité de ces dernières sur les organismes aquatiques. Les bioessais avec les sédiments peuvent aussi se révéler pertinents dans le contexte des sites pollués dans les eaux de surface. Le présent rapport constitue une vue d'ensemble des méthodes écotoxicologiques qui peuvent être utilisées pour évaluer des sites contaminés afin de déterminer si et comment elles peuvent être envisagées pour une nouvelle aide à l'exécution relative à l'OSites.

In der Schweiz ist der Einsatz von ökotoxikologischen Tests (Biotests) zur Beurteilung von Einwirkungen auf die Wasser- oder Sedimentqualität weder für den Schutz von Oberflächengewässern noch für die Untersuchung belasteter Standorte gesetzlich vorgeschrieben. Bei Letzteren wird gemäss der Verordnung über die Sanierung von belasteten Standorten (AltlV) die Beurteilung der Gefährlichkeit von Schadstoffen mit Hilfe von chemischen Analysen für jeden einzelnen Schadstoff vorgenommen. Die gemessenen Konzentrationen werden mit Grenzwerten verglichen, die auf der Grundlage humantoxikologischer Daten festgelegt werden. Im Rahmen der Abschätzung von Auswirkungen auf Ökosysteme können jedoch ökotoxikologische Tests eine relevante ergänzende Methode darstellen. Diese wurden in einer inzwischen nicht mehr gültigen Vollzugshilfe für die Beurteilung von Eluaten aus belasteten Standorten (z.B. Altlasten und Deponien) vorgeschlagen. Diese Vollzugshilfe empfahl die Verwendung einer Reihe von ökotoxikologischen Tests (mit Leuchtbakterien, Algen und Crustaceen) und in einigen Fällen zusätzliche Studien zur Gentoxizität oder chronischen Toxizität. Trotz Aufhebung der Vollzugshilfe wurden und werden ökotoxikologische Tests weiterhin regelmässig in Projekten angewendet, die von kantonalen oder kommunalen Behörden in Auftrag gegeben wurden. Biotests können sehr interessant sein, da sie die Mobilität, Mischung und Bioverfügbarkeit von Chemikalien berücksichtigen und Auskunft über die Gefährlichkeit von Chemikalien für Wasserorganismen geben. Biotests mit Sedimenten können sich auch im Zusammenhang mit belasteten Standorten in Oberflächengewässern als relevant erweisen. Der vorliegende Bericht gibt einen Überblick über ökotoxikologische Methoden, die zur Altlastenbeurteilung eingesetzt werden können, um zu ermitteln, ob und wie diese für eine neue Vollzugshilfe zur AltlV in Frage kommen könnten.

Background For use in cosmetic products, 32 substances have been authorised in the EU as UV-filters as of August 2022 (Annex VI of the EU Cosmetics Regulation (EC) No 1223/2009). Although these substances can enter the aquatic environment directly through bathing, authorisation for use in cosmetic products does not require a specific environmental risk assessment, whereas risks to human health are specifically assessed. Furthermore, no environmental quality standards have been proposed at EU level. For the current review, data on freshwater ecotoxicity, physicochemical properties, environmental fate and measured exposure were retrieved from ECHA registration information and public databases and assessed for reliability and relevance. Environmental quality standards (EQS) were proposed based on the EU technical guidance for EQS for the Water Framework Directive (WFD).

Results From a WFD perspective, there were significant or complete gaps for acute and chronic effects data, sediment organisms and rarely tested organisms at the time of data retrieval, as well as gaps for measured environmental concentrations in the assessed databases. The reliability of the reported data could not always be verified due to missing information. As expected from the heterogeneity of molecular structures, ecotoxicity data and environmental fate parameters vary considerably between the different substances. Our assessments indicate that the use of some of the substances in direct contact with surface water may pose a repeated risk to aquatic organisms.

Conclusions We recommend a revision of the process for the inclusion of UV-filters in the EU Cosmetics Product Regulation, taking into account the potential environmental risks. A full assessment of all UV-filters using standard test organisms as well as rarely tested species for acute and chronic effects and bioaccumulation would require, among other things, a large number of fish tests. Therefore, new assessment methods (NAMs) are recommended, including the use of fish cell lines for acute toxicity testing and alternatives for the assessment of chronic toxicity.

Many rivers and streams are affected by chemical pollution, yet current chemical monitoring methods are limited for technical and economic reasons. Biomonitoring has been increasingly used as a means of assessing the impacts of chemical pollution and indirectly monitoring river contamination. To provide an overview of the wide variety of biomonitoring approaches, we conducted a systematic review of the literature investigating the relationship between chemical pollution and biological responses. We distinguished five main approaches for the biomonitoring of chemical pollution: (i) monitoring of native communities; (ii) laboratory bioassays; (iii) in situ bioassays; (iv) mesocosms; and (v) monitoring of wild populations. Although each of them covers a wide range of methods and endpoints, we have highlighted their main advantages and limitations. Because native communities are exposed to a wide range of stressors, isolating the effects of chemical pollution alone is often limited. Most of the existing community indices cannot depict the full extent of the impact of pollutants on communities, but rather provide information on either general degradation of water and/or sediment quality. Effect-based methods (EBMs), including ecotoxicological bioassays and biomarkers, can better isolate the effects of pollution, and, to some extent, of specific types of pollutants. The experimental design of EBMs must be adapted to the research question and the context of the study, so that the test organisms, exposure scenarios and endpoints accurately reflect the contamination. In this context, a comparison with theoretically non-stressful situations with either a dilution series of the exposure solution in the laboratory or a comparison of laboratory and field treatment is relevant. The main difficulties encountered in the approaches investigated in the present review are the comparability of sampling strategies, non-linear concentration–response relationships, extrapolation from laboratory to field exposure, the highly variable sensitivity of organisms and the geographical specificities. Overall, a combination of different EBMs can integrate the effects of exposure to specific contaminants at both spatial and temporal scales while accounting for confounding factors. The establishment of thresholds and guidelines would facilitate the integration of EBMs into regular monitoring programmes. This in turn will greatly facilitate the assessment of chemical impairment.

Detection of micropollutants (MPs) in wastewater effluents using traditional toxicity tests or chemical analysis with discrete samples is challenging due to concentration dynamics. This study evaluates a continuous monitoring approach for detecting MPs in wastewater effluents using a combination of biological early warning systems (BEWS). Three BEWS with Chlorella vulgaris, Daphnia magna, and Gammarus pulex were operated in parallel in a full-scale municipal wastewater treatment plant. Concentrations of MPs were monitored by simultaneous online chemical analysis using high performance liquid chromatography-high resolution mass spectrometry (MS2Field). Over 5 weeks, behavioral changes observed in the BEWS occasionally exceeded acute toxicity thresholds, triggering alarms. These changes were related to MPs identified by the MS2Field, to abiotic factors, or to operational parameters of the BEWS. For one toxic event, behavioral responses were linked to a pesticide, not authorized in Switzerland, at concentrations close to literature EC₅₀ values. Verification tests confirmed that the pesticide in the effluent was the most likely cause for the organism response. The study demonstrates the potential of BEWS as a stand-alone technique for detecting contamination peaks in wastewater, and identifies key limitations and critical factors that need to be addressed to optimize the use of BEWS in wastewater monitoring.

La Vuachère est une rivière urbaine lausannoise fortement impactée par des rejets d'eaux usées non traités. Une estimation du débit d'eaux usées rejeté dans la rivière, ainsi qu'une évaluation du risque écotoxicologique des micropolluants ont été effectués sur la base d'un monitoring avec des échantillonnages composites. Cette étude de cas fait ressortir les substances les plus problématiques pour la qualité de l'eau. De plus, elle donne un état zéro qui pourra être suivi dans le temps à partir de la détermination de ces différents indicateurs.

Zur Entwicklung eines Verfahrens zur Beurteilung der Wasserqualität von Oberflächengewässern mit einer Biotestbatterie wurden insgesamt 15 Proben von Standorten mit unterschiedlicher Landnutzung mit einer umfangreichen Palette von In-vitro- und In-vivo-Biotests untersucht. Ziel des Projektes war es, eine aussagekräftige und kosteneffiziente Teststrategie für zukünftige Monitoringprojekte zu ermitteln.

Das Oekotoxzentrum hat die Wasser- und Sedimentqualität von 15 Fliessgewässern in acht Kantonen mit verschiedenen biologischen effektbasierten Methoden untersucht. So wurden drei komplementäre Projekte durchgeführt mit dem Ziel, für die umfassende Beurteilung der Wasser- und Sedimentqualität eine aussagekräftige Batterie an Biotests auszuwählen und zu validieren und Biomarkermethoden weiterzuentwickeln. Dieser Artikel gibt einen Überblick über die gewählten Methoden und Standorte und die wichtigsten Ergebnisse. Die detaillierten Ergebnisse der einzelnen Projekte werden in weiteren Artikeln dieser Aqua & Gas-Ausgabe präsentiert.

Wastewater treatment plants (WWTPs) are a major source of micropollutants to surface waters. Currently, their chemical or biological monitoring is realized by using grab or composite samples, which provides only snapshots of the current wastewater composition. Especially in WWTPs with industrial input, the wastewater composition can be highly variable and a continuous assessment would be advantageous, but very labor and cost intensive. A promising concept are automated real-time biological early warning systems (BEWS), where living organisms are constantly exposed to the water and an alarm is triggered if the organism's responses exceed a harmful threshold of acute toxicity. Currently, BEWS are established for drinking water and surface water but are seldom applied to monitor wastewater. This study demonstrates that a battery of BEWS using algae (Chlorella vulgaris in the Algae Toximeter, bbe Moldaenke), water flea (Daphnia magna in the DaphTox II, bbe Moldaenke) and gammarids (Gammarus pulex in the Sensaguard, REMONDIS Aqua) can be adapted for wastewater surveillance. For continuous low-maintenance operation, a back-washable membrane filtration system is indispensable for adequate preparation of treated wastewater. Only minor deviations in the reaction of the organisms towards treated and filtered wastewater compared to surface waters were detected. After spiking treated wastewater with two concentrations of the model compounds diuron, chlorpyrifos methyl, and sertraline, the organisms in the different BEWS showed clear responses depending on the respective compound, concentration and mode of action. Immediate effects on photosynthetic activity of algae were detected for diuron exposure, and strong behavioral changes in water flea and gammarids after exposure to chlorpyrifos methyl or sertraline were observed, which triggered automated alarms. Different types of data analysis were applied to extract more information out of the specific behavioral traits, than only provided by the vendors algorithms. To investigate, whether behavioral movement changes can be linked to impact other endpoints, the effects on feeding activity of G. pulex were evaluated and results indicated significant differences between the exposures. Overall, these findings provide an important basis indicating that BEWS have the potential to act as alarm systems for pollution events in the wastewater sector.

Mesurer l’expression des gènes est une méthode prometteuse permettant de détecter les effets précoces de stress environnementaux, dont l’exposition aux pesticides. Un outil permettant de mesurer une centaine de biomarqueurs moléculaires a été développé et utilisé chez des jeunes truites de rivières provenant de dix cours d’eau en Suisse.

Micropollutants present in the effluent of wastewater treatment plants (WWTPs) after biological treatment are largely eliminated by effective advanced technologies such as ozonation. Discharge of contaminants into freshwater ecosystems can thus be minimized, while simultaneously protecting drinking water resources. However, ozonation can lead to reactive and potentially toxic transformation products. To remove these, the Swiss Federal Office for the Environment recommends additional "post-treatment" of ozonated WWTP effluent using sand filtration, but other treatments may be similarly effective. In this study, 48 h composite wastewater samples were collected before and after full-scale ozonation, and after post-treatments (full-scale sand filtration, pilot-scale fresh and pre-loaded granular activated carbon, and fixed and moving beds). Ecotoxicological tests were performed to quantify the changes in water quality following different treatment steps. These included standard in vitro bioassays for the detection of endocrine, genotoxic and mutagenic effects, as well as toxicity to green algae and bacteria, and flow-through in vivo bioassays using oligochaetes and early life stages of rainbow trout.
Results show that ozonation reduced a number of ecotoxicological effects of biologically treated wastewater by 66 - 93%: It improved growth and photosynthesis of green algae, decreased toxicity to luminescent bacteria, reduced concentrations of hormonally active contaminants and significantly changed expression of biomarker genes in rainbow trout liver. Bioassay results showed that ozonation did not produce problematic levels of reaction products overall. Small increases in toxicity observed in a few samples were reduced or eliminated by post-treatments. However, only relatively fresh granular activated carbon (analyzed at 13,000 - 20,000 bed volumes) significantly reduced effects additionally (by up to 66%) compared to ozonation alone. Inhibition of algal photosynthesis, rainbow trout liver histopathology and biomarker gene expression proved to be sufficiently sensitive endpoints to detect the change in water quality achieved by post-treatment.

Mikroplastik beschreibt eine Vielfalt von Materialien, die gezielt hergestellt oder durch Abrieb und Zerfall gebildet werden. Sie kommen vielerorts in der Umwelt, in Organismen, in Nahrungsmitteln und somit auch in menschlichem Stuhl vor. Da nachgewiesene Materialien und solche, die in Toxizitätstest verwendet wurden, sich stark unterscheiden, ist eine abschliessende Risikobewertung bisher noch nicht möglich.

Wastewater treatment plant (WWTP) effluents release complex mixtures of organic and inorganic micropollutants, including endocrine disrupting compounds, into receiving water bodies. These substances may cause adverse effects in aquatic communities as well as in ecosystem functions they provide. The aim of this study was to determine the potential impact of secondary treated wastewater released into a small Swiss stream on leaf litter decomposition based on feeding rates of the amphipod shredder Gammarus fossarum measured in situ. Additionally, endocrine disrupting effects downstream of the WWTP were investigated by measuring vitellogenin (vg) induction in male gammarids exposed in situ, as well as estrogen receptor activation using the Yeast Estrogen Screen (YES) involving passive sampler and grab water sample extracts. Extracts were also analysed for 424 organic micropollutants and selected transformation products. Gammarid feeding rate was significantly reduced 100, 200 and 400 m downstream of the WWTP effluent relative to the upstream site. While YES results showed significantly elevated estrogenicity at downstream sites, vg production in male gammarids was not induced. A laboratory experiment, in which gammarids were exposed to WWTP effluent, supported this observation. These results, hence, suggest that treated wastewater released into aquatic ecosystems impairs the ecosystem function of leaf litter decomposition. Vg levels in male gammarids measured by UPLC-MS/MS did, however, not alter.

Wastewater treatment plant effluents are important point sources of micropollutants. To assess how the discharge of treated wastewater affects the ecotoxicity of small to medium-sized streams we collected water samples up- and downstream of 24 wastewater treatment plants across the Swiss Plateau and the Jura regions of Switzerland. We investigated estrogenicity, inhibition of algal photosynthetic activity (photosystem II, PSII) and growth, and acetylcholinesterase (AChE) inhibition. At four sites, we measured feeding activity of amphipods (Gammarus fossarum) in situ as well as water flea (Ceriodaphnia dubia) reproduction in water samples. Ecotoxicological endpoints were compared with results from analyses of general water quality parameters as well as a target screening of a wide range of organic micropollutants with a focus on pesticides and pharmaceuticals using liquid chromatography high-resolution tandem mass spectrometry. Measured ecotoxicological effects in stream water varied substantially among sites: 17β-estradiol equivalent concentrations (EEQ_bio, indicating the degree of estrogenicity) were relatively low and ranged from 0.04 to 0.85 ng/L, never exceeding a proposed effect-based trigger (EBT) value of 0.88 ng/L. Diuron equivalent (DEQ_bio) concentrations (indicating the degree of photosystem II inhibition in algae) ranged from 2.4 to 1576 ng/L and exceeded the EBT value (70 ng/L) in one third of the rivers studied, sometimes even upstream of the WWTP. Parathion equivalent (PtEQ_bio) concentrations (indicating the degree of AChE inhibition) reached relatively high values (37 to 1278 ng/L) mostly exceeding the corresponding EBT (196 ng/L PtEQ_bio). Decreased feeding activity by amphipods or decreased water flea reproduction downstream compared to the upstream site was observed at one of four investigated sites only. Results of the combined algae assay (PSII inhibition) correlated best with results of chemical analysis for PSII inhibiting herbicides. Estrogenicity was partly and AChE inhibition strongly underestimated based on measured steroidal estrogens respectively organophosphate and carbamate insecticides. An impact of dissolved organic carbon on results of the AChE inhibition assay was obvious. For this assay more work is required to further explore the missing correlation of bioassay data with chemical analytical data. Overall, the discharge of WWTP effluent led to increased estrogenicity, PSII and AChE inhibition downstream, irrespective of upstream land use.

Effect-based methods including cell-based bioassays, reporter gene assays and whole-organism assays have been applied for decades in water quality monitoring and testing of enriched solid-phase extracts. There is no common EU-wide agreement on what level of bioassay response in water extracts is acceptable. At present, bioassay results are only benchmarked against each other but not against a consented measure of chemical water quality. The EU environmental quality standards (EQS) differentiate between acceptable and unacceptable surface water concentrations for individual chemicals but cannot capture the thousands of chemicals in water and their biological action as mixtures. We developed a method that reads across from existing EQS and includes additional mixture considerations with the goal that the derived effect-based trigger values (EBT) indicate acceptable risk for complex mixtures as they occur in surface water. Advantages and limitations of various approaches to read across from EQS are discussed and distilled to an algorithm that translates EQS into their corresponding bioanalytical equivalent concentrations (BEQ). The proposed EBT derivation method was applied to 48 in vitro bioassays with 32 of them having sufficient information to yield preliminary EBTs. To assess the practicability and robustness of the proposed approach, we compared the tentative EBTs with observed environmental effects. The proposed method only gives guidance on how to derive EBTs but does not propose final EBTs for implementation. The EBTs for some bioassays such as those for estrogenicity are already mature and could be implemented into regulation in the near future, while for others it will still take a few iterations until we can be confident of the power of the proposed EBTs to differentiate good from poor water quality with respect to chemical contamination.

Background: The European Commission Implementing Decision EU 2015/495 included three steroidal estrogens, namely 17α-ethinyl estradiol, 17β-estradiol, and estrone, in the so-called "watch list" of the EU Water Framework Directive (WFD). The monitoring of these compounds is difficult because the detection limits of the majority of the available analytical methods cannot achieve the very low target concentrations required to meet proposed environmental quality criteria. In 2014, a combined Science-Policy Interface/Chemical Monitoring of Emerging Pollutants project was launched to meet this monitoring challenge. The project involved 24 research organizations and environmental agencies from 12 different countries.
Methods: Sixteen surface water (SW) and 17 wastewater (WW) samples were collected across Europe and analysed using five in vitro effect-based and three chemical analytical methods. A general description of the project and data evaluation is provided by Könemann and colleagues in the companion publication 2018. In our study, we compared bioanalytical and chemical analytical results with regard to their application for aquatic status assessment. Therefore we considered the potential to predict population-relevant risks for aquatic organisms and the specificity and sensitivity of the various methods used in both approaches. Finally, we tested and discussed the applicability and relevance of previously suggested effect-based trigger values (EBT).
Results and discussion: Results of the risk assessment based on chemical analytical data correlated highly with estrogenic activities (expressed as 17β-estradiol equivalents (EEQ) determined using effect-based methods), demonstrating the ability of the bioassays to predict the mixture risk caused by steroidal estrogens. For about 15% of SW and 40% of WW samples detection limits of chemical-analytical methods were too high to allow a status assessment, while detection limits of all effect-based methods were below proposed EBT. This demonstrates that effect-based methods are suitable for status assessment of surface waters. The in vitro effect-based methods were quite specific for steroidal estrogens and highly sensitive, meaning they have a low probability to detect false positive or negative results. After testing of three alternative EBT proposals, we concluded to use preliminary 400 pg/L EEQ as screening EBT corresponding to the AA-EQS of E2. Further test specific refinements in the application of this value are not excluded.
Conclusions: We conclude that water quality assessment can progress from a purely analytical approach to effect-based monitoring, from single substance to known and unknown mixture assessment and from in vitro screening to population-relevant risk assessment. Despite a few limitations, effect-based in vitro methods are recommendable for monitoring steroidal estrogens under the WFD because they, a) are able to sensitively quantify the activity of steroidal estrogens in all surface and wastewater samples, b) are able to detect the combined effect of estrogen mixtures including unknown chemicals with estrogen receptor activating properties, c) allow an ecotoxicological status assessment using EBT to calculate risk quotients. This approach is similar to the risk ratio used in regulatory environmental risk assessments, but allows for an integrated mixture assessment.

Eine Beurteilung der Wasserqualität mit Biotests kann besonders dann sinnvoll sein, wenn biologisch aktive Stoffe und Stoffgemische vorhanden sind, die mit chemischer Analytik nur unvollständig erfasst werden können. Nun wurde im Rahmen des Modul-Stufen-Konzepts (MSK) ein Konzept zur Grobbeurteilung von abwasserbelasteten Fliessgewässern mit ökotoxikologischen Biotests entwickelt. Das Konzept stellt einen ersten Schritt zur integrativen Beurteilung der Wasserqualität dar.

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

The efficiency of ozone-based processes under various conditions was studied for the treatment of a surface water (Lake Zürich water, Switzerland) spiked with 19 micropollutants (pharmaceuticals, pesticides, industrial chemical, X-ray contrast medium, sweetener) each at 1 μg L⁻¹. Two pilot-scale ozonation reactors (4–5 m³ h⁻¹), a 4-chamber reactor and a tubular reactor were investigated by either conventional ozonation and/or the advanced oxidation process (AOP) O₃/H₂O₂. The effects of selected operational parameters, such as ozone dose (0.5–3 mg L⁻¹) and H₂O₂ dose (O₃:H₂O₂ = 1:3–3:1 (mass ratio)), and selected water quality parameters, such as pH (6.5–8.5) and initial bromide concentration (15–200 μg L⁻¹), on micropollutant abatement and bromate formation were investigated. Under the studied conditions, compounds with high second-order rate constant k_O3>10⁴ M⁻¹ s⁻¹ for their reaction with ozone were well abated (>90%) even for the lowest ozone dose of 0.5 mg/L. Conversely, the abatement efficiency of sucralose, which only reacts with hydroxyl radicals (·OH), varied between 19 and 90%. Generally, the abatement efficiency increased with higher ozone doses and higher pH and lower bromide concentrations. H₂O₂ addition accelerated the ozone conversion to radical ·OH, which enables a faster abatement of ozone-resistant micropollutants. Interestingly, the abatement of micropollutants decreased with higher bromide concentrations during conventional ozonation due to competitive ozone-consuming reactions, except for lamotrigine, due to the suspected reaction of HOBr/OBr⁻ with the primary amine moieties. In addition to the abatement of micropollutants, the evolution of the two main transformation products (TPs) of hydrochlorothiazide (HCTZ) and tramadol (TRA), chlorothiazide (CTZ) and tramadol N-oxide (TRA-NOX) respectively, was assessed by chemical analysis and kinetic modelling. Both selected TPs were quickly formed initially to reach a maximum concentration followed by a decrease of their concentrations for longer contact times. For the studied conditions, the TP's concentrations at the outlet of the reactors ranged from 0 to 61% of the initial parent compound concentration, CTZ being a more persistent TP than TRA-NOX. Finally, it was demonstrated in both reactors that the formation of bromate (BrO₃−), a potentially carcinogenic oxidation by-product, could be controlled by H₂O₂ addition with a general improvement on micropollutant abatement. Post-treatment by granular activated carbon (GAC) filtration enabled the reduction of micropollutants and TPs concentrations but no changes in bromate were observed. The combined algae assays showed that water quality was significantly improved after oxidation and GAC post-treatment, driven by the abatement of the spiked pesticides (diuron and atrazine).

Der vorliegende Bericht fasst die Ergebnisse des Forschungsprojektes "Biologische Nachbehandlung von kommunalem Abwasser nach Ozonung", kurz "ReTREAT", zusammen. Das Projekt wurde durch das Bundesamtes für Umwelt (BAFU) im Rahmen der Umwelttechnologieförderung (UTF) finanziert. Zudem wurde das Projekt durch hohe Eigen- und Cash-Leistungen der Industriepartner finanziell und technisch unterstützt.
Ziel des Projektes war es Untersuchungen zur Leistungsfähigkeit und Effizienz verschiedener Verfahren der biologischen Nachbehandlung zur Reduktion der ökotoxikologischen Wirkung und zur Reduktion von Transformationsprodukten von ozonten, kommunalem Abwassers durchzuführen.

Im Rahmen des Projekts ReTREAT wurden verschiedene Verfahren auf deren Eignung als biologische Nachbehandlung nach einer Ozonung getestet. Der Fokus lag dabei – neben allgemeinen Reinigungseffekten – insbesondere auf dem Abbau von labilen Reaktionsprodukten sowie deren ökotoxikologischen Wirkungen.

Das Wichtigste in Kürze:

• Die Ozonung reduziert ökotoxikologische Effekte deutlich und verbessert die Abwasserqualität signifikant.
• Unmittelbar nach der Ozonung sind nur in Einzelfällen geringe „Auffälligkeiten“ aufgetreten (z.B. Mutagenität). Das ist nicht erstaunlich, da es sich bei der ARA Neugut um ein Abwasser handelt, das für eine Ozonung geeignet ist (d.h. durch die Ozonbehandlung wird grundsätzlich eine Verbesserung der Abwasserqualität erreicht, und es werden keine oder kaum problematische Oxidationsnebenprodukte gebildet).
• Die Abwasserqualität ist durch die Nachbehandlung nach Ozonung in nur wenigen Fällen noch weiter verbessert worden
• Da durch die Ozonung keine deutlichen messbaren toxischen Effekte (Toxizitätszunahme) aufgetreten sind, ist ein Vergleich der Nachbehandlungsverfahren anhand der verwendeten Biotests schwierig.
• Auf Grund der zusätzlichen Elimination von organischen Spurenstoffen (Kombination einer „vollen“ Ozonung mit einer Aktivkohlebehandlung) hat der Filter mit neuer granulierter Aktivkohle etwas besser abgeschnitten. Bezüglich der Elimination von toxischen labilen Reaktionsprodukten – die Hauptaufgabe einer Nachbehandlungsstufe – hat sich dieser GAK-Filter nicht von den anderen Nachbehandlungsverfahren unterschieden.

In vitro estrogen receptor transactivation assays (ERTAs) are increasingly used to measure the overall estrogenic activity of environmental water samples, which may serve as an indicator of exposure of fish or other aquatic organisms to (xeno)estrogens. Another potential area of application of ERTAs is to assist the monitoring of the potent steroids 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) under the Water Framework Directive (WFD) watch-list mechanism. Chemical analysis of E2 and EE2 is currently hampered by limits of quantification being mostly above the proposed annual average Environmental Quality Standards (AA-EQS) of 0.4 and 0.035 ng/L, respectively. Sensitive ERTAs could circumvent current detection challenges by measuring total estrogenic activity expressed as E2-equivalent (EEQ) concentrations.
However, the use of different ERTAs results in different EEQ concentrations for the same sample. Reasons for these differences are known, but it remains unclear how to use and interpret bioassay results in a harmonised way. The aim of this study was to compare the intra- and inter-day variability of EEQ measurements using five different ERTAs (YES, ERα-CALUX, MELN, T47D-KBluc and GeneBLAzer-ERα) with regard to their applicability as effect-based tools in environmental monitoring.
Environmentally relevant artificial mixtures of (xeno)estrogens were prepared to represent samples with higher (i.e. multiple times the AA-EQS for E2) or lower pollution levels (i.e. around the AA-EQS for E2). Mixtures were tested either directly or following solid phase extraction (SPE). The SPE step was included, as environmental samples typically require enrichment before analysis. Samples were analysed repeatedly to test intra-day and inter-day variability. Estrogenicity was quantified using the 10% effect level (PC10) of the positive control (E2) and expressed as EEQ concentrations.
The average coefficient of variation (CV) of EEQ concentrations for the five ERTAs and all samples was 32%. CV was lower for intra-day experiments (30%) compared to inter-day experiments (37%). Sample extraction using SPE did not lead to additional variability; the intra-day CV for SPE extracted samples was 28%. Of the five ERTAs, ERα-CALUX had the best precision and repeatability (overall CV of 13%).

Surface waters can contain a range of micropollutants from point sources, such as wastewater effluent, and diffuse sources, such as agriculture. Characterizing the source of micropollutants is important for reducing their burden and thus mitigating adverse effects on aquatic ecosystems. In this study, chemical analysis and bioanalysis were applied to assess the micropollutant burden during low flow conditions upstream and downstream of three wastewater treatment plants (WWTPs) discharging into small streams in the Swiss Plateau. The upstream sites had no input of wastewater effluent, allowing a direct comparison of the observed effects with and without the contribution of wastewater. Four hundred and five chemicals were analyzed, while the applied bioassays included activation of the aryl hydrocarbon receptor, activation of the androgen receptor, activation of the estrogen receptor, photosystem II inhibition, acetylcholinesterase inhibition and adaptive stress responses for oxidative stress, genotoxicity and inflammation, as well as assays indicative of estrogenic activity and developmental toxicity in zebrafish embryos. Chemical analysis and bioanalysis showed higher chemical concentrations and effects for the effluent samples, with the lowest chemical concentrations and effects in most assays for the upstream sites. Mixture toxicity modeling was applied to assess the contribution of detected chemicals to the observed effect. For most bioassays, very little of the observed effects could be explained by the detected chemicals, with the exception of photosystem II inhibition, where herbicides explained the majority of the effect. This emphasizes the importance of combining bioanalysis with chemical analysis to provide a more complete picture of the micropollutant burden. While the wastewater effluents had a significant contribution to micropollutant burden downstream, both chemical analysis and bioanalysis showed a relevant contribution of diffuse sources from upstream during low flow conditions, suggesting that upgrading WWTPs will not completely reduce the micropollutant burden, but further source control measures will be required.

Im Projekt EcoImpact wurden die ökotoxikologischen und ökologischen Effekte von Mikroverunreinigungen aus Kläranlagen auf aquatische Lebensgemeinschaften untersucht. Chemische und biologische Untersuchungen oberhalb und unterhalb von Kläranlagen deuten auf Effekte dieser Stoffe hin, die von physiologischen Antworten der Organismen bis hin zu veränderten Ökosystemfunktionen wie z. B. dem Laubabbau reichen. Gezielte Rinnenexperimente mit kontrollierter Wasserqualität unterstützen diese Befunde.

The overarching aim of this field study was to examine causal links between in-situ exposure to complex mixtures of micropollutants from wastewater treatment plants and effects on freshwater microbial communities in the receiving streams. To reach this goal, we assessed the toxicity of serial dilutions of micropollutant mixtures, extracted from deployed passive samplers at the discharge sites of four Swiss wastewater treatment plants, to in situ periphyton from upstream and downstream of the effluents. On the one hand, comparison of the sensitivities of upstream and downstream periphyton to the micropollutant mixtures indicated that algal and bacterial communities composing the periphyton displayed higher tolerance towards these micropollutants downstream than upstream. On the other hand, molecular analyses of the algal and bacterial structure showed a clear separation between upstream and downstream periphyton across the sites. This finding provides an additional line of evidence that micropollutants from the wastewater discharges were directly responsible for the change in the community structure at the sampling sites by eliminating the micropollutant-sensitive species and favouring the tolerant ones. What is more, the fold increase of algal and bacterial tolerance from upstream to downstream locations was variable among sampling sites and was strongly correlated to the intensity of contamination by micropollutants at the respective sites. Overall, our study highlights the sensitivity of the proposed approach to disentangle effects of micropollutant mixtures from other environmental factors occurring in the field and, thus, establishing a causal link between exposure and the observed ecological effects on freshwater microbial communities.

Endocrine-disrupting chemicals (EDCs) are man-made compounds interfering with hormone signaling. Omnipresent in the environment, they can cause adverse effects in a wide range of wildlife. Accordingly, Endocrine Disruption is one focal area of ecotoxicology. Because EDCs induce complex response patterns in vivo via a wide range of mechanisms of action, in vitro techniques have been developed to reduce and understand endocrine toxicity. In this review we revisit the evidence for endocrine disruption in diverse species and the underlying molecular mechanisms. Based on this, we examine the battery of in vitro bioassays currently in use in ecotoxicological research and discuss the following key questions. Why do we use in vitro techniques? What endpoints are we looking at? Which applications are we using in vitro bioassays for? How can we put in vitro data into a broader context? And finally, what is the practical relevance of in vitro data? In critically examining these questions, we review the current state-of-the-art of in vitro (eco)toxicology, highlight important limitations and challenges, and discuss emerging trends and future research needs.

The efficiency of wastewater ozonation for the abatement of three nitrogen-containing pharmaceuticals, two antihistamine drugs, cetirizine (CTR) and fexofenadine (FXF), and the diuretic drug, hydrochlorothiazide (HCTZ), was investigated. Species-specific second-order rate constants for the reactions of the molecular, protonated (CTR, FXF) or deprotonated (HCTZ) forms of these compounds with ozone were determined. All three compounds are very reactive with ozone (apparent second order rate constants at pH 7: k_O3,pH7 = 1.7·10⁵ M⁻¹s⁻¹, 8.5·10⁴ M⁻¹s⁻¹ and 9.0·10³ M⁻¹s⁻¹ for CTR, HCTZ and FXF, respectively). Transformation product (TP) structures were elucidated using liquid chromatography coupled with high-resolution tandem mass spectrometry, including isotope-labeled standards. For cetirizine and hydrochlorothiazide 8 TPs each and for fexofenadine 7 TPs were identified. The main TPs of cetirizine and fexofenadine are their respective N-oxides, whereas chlorothiazide forms to almost 100% from hydrochlorothiazide. In the bacteria bioluminescence assay the toxicity was slightly increased only during the ozonation of cetirizine at very high cetirizine concentrations. The main TPs detected in bench-scale experiments were also detected in full-scale ozonation of a municipal wastewater, for >90% elimination of the parent compounds.

Die Ozonung ist ein etabliertes Behandlungsverfahren, um Mikroverunreinigungen aus Abwasser zu entfernen. Da bei der Ozonung jedoch labile toxische Reaktionsprodukte entstehen können, ist eine biologische Nachbehandlung notwendig. Mithilfe von Biotests hat das Oekotoxzentrum verglichen, wie gut die Ozonung in Kombination mit verschiedenen Nachbehandlungsverfahren ökotoxikologische Effekte verringern kann.

La qualité des eaux est habituellement évaluée sur la base d'analyses chimiques en comparant les concentrations mesurées à des critères de qualité individuels déterminés en fonction des effets des substances isolées. Cette méthode ne peut cependant s'appliquer qu'aux polluants connus pour lesquels des données sont disponibles en qualité et en quantité suffisantes. Pour aller au-delà de cette limite, l'appréciation doit recourir à des méthodes intégratives comme les bioessais écotoxicologiques. Ces derniers permettent de déterminer la toxicité générale de l'eau ou de l'effluent ou de mesurer les effets de groupes de substances apparentées.
Dans ce cadre, la qualité de l’eau de la Versoix concernant les perturbateurs endocriniens de type oestrogène a été évaluée en appliquant le bioessai ER-CALUX®. C’est un bioessai utilisant des cellules humaines très sensibles. En plus, la qualité d’eau concernant des inhibiteurs du photosystème II a été évalué par un teste algues combiné.
Les concentrations des substances d’activité oestrogénique et des inhibiteurs du photosystème II ont été déterminées dans des échantillons de la rivière Versoix, ainsi que dans des échantil-lons de l’effluent de la STEP de Divonne. La qualité de l’eau a ensuite été jugée par un système en cinq classes.
L'étude de l'activité oestrogénique et de l'inhibition du photosystème II a permis de mettre en évidence une influence de la STEP de Divonne sur la Versoix, le cours d'eau récepteur. En aval du point de rejet de l’effluent, les teneurs en équivalents 17β-oestradiol (EEQ) et en équivalents diuron (DEQ) mesurées avec les bioessais étaient en général plus élevées qu'en amont. Mais, cette augmentation était faible.
Dans l'ensemble, la pollution par les substances d’activité oestrogénique et par les inhibiteurs du photosystème II peut être jugée peu significative en termes d'impacts. Les teneurs en EEQ et en DEQ dans la Versoix ne dépassaient jamais la valeur de 0.4 ng/L fixée pour le critère de qualité « chronique » (CQC) du 17β-oestradiol et la valeur de 20 ng/L fixée pour le CQC du diu-ron.

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.

The current deliverable summarizes the work conducted on the implementation of in vitro bioassays as new screening systems in water quality monitoring, starting with a description of the relatively broad bioassay panel as it was selected before evaluation of the water treatment technologies in the case studies. The case studies were conducted together with work area 1-3 partners. The case studies had a twofold aim: 1: To assess the performance of the novel water treatment technologies with bioassays, mainly focussing on removal of bioactivity. 2: Further assessment of the optimal application domain of the bioassays, selecting subpanels suitable for particular applications. This was done in a final evaluation using case study results as a main guidance. Finally, we placed these bioassays in an innovative novel testing framework as designed by Waternet (called SIMONI) to further promote dissemination and practical application of the DEMEAU bioassay panel in water utilities

Auf der ARA Basel der ProRheno AG, die hauptsächlich kommunales Abwasser reinigt, wird aufgrund ihrer Grösse eine zusätzliche Stufe zur Elimination von Mikroverunreinigungen nötig sein. Während mehreren Monaten wurde in einer Pilotanlage untersucht, ob sich die Verfahren Zugabe von Pulveraktivkohle (PAK) und Ozonung grundsätzlich auf der ARA Basel eignen. Zusätzlich wurde die Reinigungsleistung der weitergehenden Abwasserbehandlung für kommunales Abwasser der ARA Basel getestet, das einen gewissen Anteil biologisch gereinigtes Industrieabwasser enthielt.

Einleitung: In der Schweiz werden im Rahmen des Projektes Modul-Stufen-Konzept (MSK) standardisierte Methoden für die Untersuchung und Bewertung des Zustandes der Fliessgewässer erarbeitet, um so strukturelle, hydrologische, biologische, chemische sowie ökotoxikologische Aspekte der Wasserqualität zu erfassen und gegebenenfalls Massnahmen zur Verminderung dieser Belastung ergreifen zu können.
Zielsetzung der Arbeiten im Rahmen eines Moduls Ökotoxikologie innerhalb des MSK ist die Entwicklung eines Konzeptes zur routinemässigen Beurteilung der Wasserqualität anhand von ökotoxikologischen Biotests, bestehend aus Probenahme, Probenaufbereitung, Durchführung der Biotests und Beurteilung der Effekte. Die Biotests sollen sensitiv, wirkungsbasiert, einfach durchführbar, kostengünstig und gut interpretierbar sein. Im vorliegenden Bericht wird nun ein Konzept zur Grobbeurteilung der Wasserqualität von abwasserbelasteten Gewässern mit ökotoxikologischen Biotests vorgestellt. [...]

Um die Wasserqualität anhand von ökotoxikologischen Biotests beurteilen zu können, werden empfindliche, robuste, standardisierte und möglichst kosteneffiziente Biotests benötigt. Zur Auswahl dafür geeigneter Biotests wurden im Rahmen der Arbeiten zu einem Modul Ökotoxikologie im Schweizerischen Modul-Stufen-Konzept eine Literaturrecherche, eine Expertenbefragung und ein Expertenworkshop durchgeführt. Ziel der Arbeiten war die Identifizierung der relevantesten biologischen Wirkmechanismen von Umweltschadstoffen und von Biotests, mit denen diese Effekte gemessen werden können. Der vorliegende Bericht fasst die Ergebnisse zusammen, empfiehlt Biotests, welche für eine Beurteilung der Wasserqualität geeignet sind, und zeigt den Handlungsbedarf auf. [...]

The assessment of water quality based on ecotoxicological bioassays requires the availability of sensitive, robust, standardized and preferably cost-effective methods. As part of the module ecotoxicology within the framework of the Swiss modular stepwise procedure, we conducted an extensive literature search, consulted a group of experts and conducted an expert workshop to identify bioassays with such characteristics. Our aim was the identification of the most relevant biological modes of action of environmental pollutants, and of bioassays to measure such effects. This report summarizes the results and provides recommendations for those bioassays well suited to evaluate water quality, but also shows were further action is required. [...]

Toxizitätstests auf der Basis von Zellkulturen oder Organismen eignen sich, um die Reinigungsleistung einer Kläranlage in Bezug auf Mikroverunreinigungen zu überprüfen. Damit lassen sich im Routineeinsatz nicht nur Einzelstoffe, sondern auch Gemische ökotoxikologisch beurteilen, wie im Rahmen des Projektes «Strategie Micropoll» des Bundesamtes für Umwelt gezeigt werden konnte.

In the context of the European Water Framework Directive (WFD) it is fully recognized that pharmaceuticals can represent a relevant issue for the achievement of the good chemical and ecological status of European surface water bodies. The recent European Directive on the review of priority substances in surface water bodies has included three pharmaceuticals of widespread use (diclofenac, 17α-ethinylestradiol (EE2), 17β-estradiol (E2)) in the European monitoring list, the so-called watch list. Endocrine active pharmaceuticals such as EE2 and E2 (also occurring as natural hormone) can cause adverse effects on aquatic ecosystems at very low levels. However, monitoring of these pharmaceuticals within the watch list mechanism of the WFD and national monitoring programs can be difficult because of detection problems of most routine analytical methods. With proposed annual average Environmental Quality Standards (AA-EQS) of 0.035 ng/L and 0.4 ng/L, respectively, the estrogenic pharmaceutical EE2 and the natural hormone E2 are among those substances. Sensitive in vitro bioassays could reduce the current detection problems by measuring the estrogenic activity of environmental samples. In a short review article the application of this approach to screen and assess the risks of endocrine active pharmaceuticals with a focus on estrogenic pharmaceuticals in environmental waters is discussed.

Oxidative treatment is one of the options to eliminate emerging pollutants (EPs) from drinking water or wastewater. For drinking water treatment, the ozonation technology is already implemented at many sites all around the world, so far mostly for disinfection purposes. However, in some countries such as the Netherlands surface water contains relatively high bromide concentrations, which leads upon reaction with ozone to the formation of bromate, a suspe cted carcinogen. In such a case, UV/H₂O₂ treatment is considered a useful alternative, despite the fact that energy requirements are substantially higher compared to treatment with ozone or O₃/H₂O₂. Only in recent years, the oxidative treatment of wastewat er has been investigated to not only protect our water resources, but also the ecosystem from pollution with chemicals used in our daily life. In Switzerland, the first permanent full scale plant with ozonat ion, WWTP Neugut in Dübendorf, is running since March 2014. Its performance was investigated i n detail in the DEMEAU project.
The goal of this paper is to present a decision basis for the implementation of oxidation technologies to eliminate EPs. Depending on the composition of the water in different European regions, one or the other treatment is recommended. The different parameters that influence the efficiency of oxidation and the formation of by - products are discussed. A decision tool is presented to decide if oxidative treatment of wastewater is rec ommended and under which circumstances the treatment of drinking water with ozone, O₃/H₂O₂, or UV/H₂O₂ may be the treatment of choice.

Bioanalytical tools hold great promise in being introduced and integrated in current water monitoring strategies which mainly utilize chemical analytics at present. The latter focuses mainly on compound identification irrespective of the biological effect. Bioassays are suitable to assess hazards even of complex mixtures of pollutants with limited possibilities of chemical identification and are therefore expected to be highly complementary to modern chemical analytical methods. Smart combinations of chemical- and biological analytics therefore can lead to reduced uncertainty in safety assessments at lower costs. This document is aimed at the selection of a minimal panel of in vitro bioassays for cost effective comprehensive toxicity screening for the evaluation of drinking water quality. After determination of selection criteria for such assays and the most relevant toxicological effects of concern, the appropriate bioassay panel is identified to detect human health effects of emerging (micro)pollutants. The project has started with identifying the most relevant toxicological endpoints or modes of action that will be used as a starting point for the effect-based assessment of water quality, in particular for human health. A set of selection criteria has been defined to assess the effect-based assays whether they are suitable to detect activity towards the selected endpoints. Using the selection criteria we established a state-of-the art bioassay panel for comprehensive screening of the water cycle and including drinking water safety assessment.

The Water Framework Directive (WFD), 2000/60/EC, requires an integrated approach to the monitoring and assessment of the quality of surface water bodies. The chemical status assessment is based on compliance with legally binding Environmental Quality Standards (EQSs) for selected chemical pollutants (priority substances) of EU-wide concern. In the context of the mandate for the period 2010 to 2012 of the subgroup Chemical Monitoring and Emerging Pollutants (CMEP) under the Common Implementation Strategy (CIS) for the WFD, a specific task was established for the elaboration of a technical report on aquatic effect-based monitoring tools. The activity was chaired by Sweden and co-chaired by Italy and progressively involved several Member States and stakeholders in an EU-wide drafting group. The main aim of this technical report was to identify potential effect-based tools (e.g. biomarkers and bioassays) that could be used in the context of the different monitoring programmes (surveillance, operational and investigative) linking chemical and ecological status assessment. The present paper summarizes the major technical contents and findings of the report.

This project report summarizes work conducted in work package 11. Along with the deliverable 11.1 and milestone report 11 it covers the tasks from work package 11 as formulated in the Description of Work (DoW). The content of the different sections is interrelated, but each section is organized as an independent part. Title of this report differs from DoW because recommendations for optimum design and operation will be handled in the deliverable 12.2. The sections in this report cover various topics and each section can be found as a stand-alone report in the DEMEAU tool box (http://demeaufp7. eu/toolbox/) for download. Detailed summaries can be found for each section separately.

In vitro bioassays are techniques that promise great steps forward in drinking water security. The technique is based on engineered cells that show a reaction if the sample they are exposed to contains toxins. A wide range of in vitro bioassays has been applied for water quality assessment.

The water quality in Swiss water bodies reaches a high standard. However, since a few years trace substances, called micropollutants, are detected in very low concentrations (nanograms per liter to micrograms per liter) in surface waters. Since it is proven by several studies that these compounds can affect the aquatic ecology, the Federal Office for the Environment (FOEN) decided in 2009, that 100 waste water treatment plants (WWTPs) in Switzerland must be updated in order to ameliorate the removal of micropollutants out of sewage water. To investigate the impact of these plant renewals on the water quality, a project called EcoImpact was initiated by the water research institute named Swiss Federal Institute of Aquatic Science and Technology (Eawag). The present bachelor thesis was conducted in the scope of this project. The aim of the thesis was to investigate the impact of micropollutants on the feeding activity of caged Gammarus fossarum by utilizing an in situ bioassay in four streams adjacent to different WWTPs (Sévery, Hochdorf, Buttisholz, Herisau). Furthermore, strategies should be established to enhance the applicability of the bioassay. At the study site Buttisholz the mean feeding rate downstream of the WWTP was significantly lower (P = 0.0024) than upstream. However, at all other study sites no significantly reduced feeding rates could be measured downstream of the associated WWTP. In Hochdorf the mean feeding rate downstream of the WWTP was even higher than upstream (but not significantly). Additionally, the feeding rates could not be determined at the deployment site Herisau, as the majority of the leaves (standardised nourishment for the gammarids) were heavier after the cage deployment than before. As recommendations for the amelioration of the in situ bioassay it can be stated that a less fragile leaf species would be easier to handle. Moreover, an anesthetic for the gammarids should be considered in order to daze the animals before the drying. Furthermore, it is advisable to increase the replicates per study site. Besides, further efforts shall be made in the culturing of gammarids in the laboratory. A more efficient procedure for the conditioning of the leaves would also be an asset.

Die Wasserqualität in Schweizer Gewässern erreicht einen hohen Standard. Seit einigen Jahren jedoch werden Spurenstoffe, sogenannte Mikroverunreinigungen, in sehr tiefen Konzentrationen (Nanogramm pro Liter bis Mikrogramm pro Liter) in Oberflächengewässern nachgewiesen. Mittels verschiedener Studien konnte bewiesen werden, dass diese Stoffe die aquatische Ökologie beeinflussen können. Aus diesem Grund hat das Bundesamt für Umwelt (BAFU) im Jahr 2009 entschieden, dass 100 Kläranlagen in der Schweiz saniert werden müssen, damit diese Mikroverunreinigungen besser aus dem Abwasser entfernt werden können. Um die Auswirkungen der Erneuerungen der Kläranlagen auf die Wasserqualität zu untersuchen, wurde vom Wasserforschungsinstitut mit dem korrekten Namen Eidgenössische Anstalt für Wasserversorgung, Abwasserreinigung und Gewässerschutz (Eawag) das Projekt EcoImpact injiziert. Diese Bachelorarbeit wurde im Rahmen dieses Projektes durchgeführt. Das Ziel der Arbeit war, mit Hilfe von in situ Bioassays, den Einfluss von Mikroverunreinigungen auf die Frassaktivität von in Käfigen ausgesetzten Bachflohkrebsen (Gammarus fossarum) in vier an Kläranlagen (Sévery, Hochdorf, Buttisholz, Herisau) angrenzenden Fliessgewässern zu untersuchen. Des weiteren sollten Verbesserungsmöglichkeiten für die Anwendung des Bioassays entwickelt werden. Am Untersuchungsstandort Buttisholz war die durchschnittliche Frassrate der Gammariden unterhalb der Kläranlage signifikant tiefer (p = 0.0024) als oberhalb. Jedoch haben die Amphipoden an allen anderen Untersuchungsstandorten unterhalb der Kläranlage nicht signifikant weniger gefressen. In Hochdorf frassen die Tiere unterhalb der Kläranlage sogar mehr als oberhalb (aber nicht signifikant mehr). Die Daten des Standortes Herisau konnten nicht verwendet werden, weil fast alle Blätter (standardisierte Nahrung für die Gammariden) nach dem Experiment schwerer waren als vorher. Für die Verbesserung des Bioassays wird empfohlen andere, weniger zerbrechliche Blattsorten zu verwenden weil diese einfacher zu handhaben wären. Ausserdem wäre es schonender die Krebse vor dem Trocknen mit einem Narkosemittel zu betäuben. Zusätzlich könnten die Anzahl der Replikate pro Standort erhöht werden. Weitere Bemühungen sollten zudem unternommen werden um eine Methode zu finden Gammariden im Labor züchten. Ein zusätzlicher Vorteil wäre zudem ein effizienteres Verfahren für das Konditionieren der Blattscheiben anzuwenden.

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. A comprehensive protection can be achieved by combining several biocides. During rain events and over time, biocides will gradually leach out and thus have the potential to affect soil or aquatic ecosystems.
In this project 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 in accordance with standard EN 16105. Concentrations of the biocides were measured using LC-MS. 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. For aquatic effects, the toxic potential of a sample was expressed as a 50% effect concentration (EC50) based on sample dilution factors (DF; the sample volume and volume of culture medium used for dilution divided by the sample volume). [...]

Ziel: Erweiterte Behandlungsmethoden in Abwasserreinigungsanlagen (ARA) können mit Hilfe von Biotests bewertet werden - dies haben Untersuchungen im Projekt „Strategie Micropoll“ des Schweizerischen Bundesamtes für Umwelt (BAFU) gezeigt. Im Rahmen einer Pilotstudie der ProRheno AG wurde untersucht ob sich auf der ARA Basel eine Behandlung mit Pulverak-tivkohle oder eine Ozonung gefolgt von einer biologischen Behandlungsstufe (Wirbelbett) bes-ser als zusätzliche Reinigungsstufe eignet. Beide Methoden können schädliche Mikroverunrei-nigungen, die durch die biologische Reinigung nicht komplett entfernt wurden, weiter reduzieren. [...]

Purpose. In order to assess possible adverse effects originating from pulp deposits in a Swiss lake, a sediment quality triad approach was applied with chemical, ecotoxicological and ecological assessment methods.
Materials and methods. To obtain an integrative picture of the potential ecotoxicological effects on organisms of different trophic levels, four test procedures were applied. The acute effects of pulp deposit pore water on a decomposer, the amphipod Gammarus fossarum, were monitored. Chronic toxicity of the pore water was evaluated on primary producers via a growth inhibition test with unicellular green algae (Pseudokirchneriella subcapitata) and on secondary consumers in a reproduction test with the water flea Ceriodaphnia dubia. To evaluate the effects of the pulp deposit on sediment inhabitants, a whole-life-cycle test with the non-biting midge Chironomus riparius was undertaken. Chemical assessment included dissolved organic carbon, extractable organic halogenic compounds, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals. The composition of the macrozoobenthos community was analysed in order to assess the ecological effects.
Results and discussion. G. fossarum displayed increased locomotor activity at 12.5% but not at 25% sample concentration during a short-time exposure of 20 h. Chronic effects compromised the reproduction and growth of C. dubia (lowest observed effect concentration, 12.5% sample concentration) with zero population growth in 100% pulp deposit pore water. In 100% pulp deposit, C. riparius exhibited increased mortality at 10 and 17 days after oviposition. Pulp deposits of 50% and 100% concentration caused a significantly lower emergence compared with the reference treatments (lake sediment and quartz sand). Additionally, the locomotor activity of chironomids decreased significantly in 25–100% pulp deposit. No chronic effects of pulp deposit pore water on algae photosynthesis and growth could be detected. The bioassay results were in accordance with an elevated content of PAHs, PCBs and metals in the pulp deposit. Significantly more organisms known to be tolerant to organic pollution were present within the macrozoobenthos community
Conclusions. In general, for sediment inhabitants such as chironomids, the pulp deposit has to be classified toxic. In the present test setup, the toxicity of the pulp deposit was reflected better by the chronic test systems applied than by the acute ones. The applied testing framework could be a suitable tool to assess the risk of contaminated sites, and this information will help decide whether risk mitigation measures should be taken. In addition, with a similar approach, the success of any mitigation measures taken can be assessed.

Many organic micropollutants present in wastewater, such as pharmaceuticals and pesticides, are poorly removed in conventional wastewater treatment plants (WWTPs). To reduce the release of these substances into the aquatic environment, advanced wastewater treatments are necessary. In this context, two large-scale pilot advanced treatments were tested in parallel over more than one year at the municipal WWTP of Lausanne, Switzerland. The treatments were: i) oxidation by ozone followed by sand filtration (SF) and ii) powdered activated carbon (PAC) adsorption followed by either ultrafiltration (UF) or sand filtration. More than 70 potentially problematic substances (pharmaceuticals, pesticides, endocrine disruptors, drug metabolites and other common chemicals) were regularly measured at different stages of treatment. Additionally, several ecotoxicological tests such as the Yeast Estrogen Screen, a combined algae bioassay and a fish early life stage test were performed to evaluate effluent toxicity. Both treatments significantly improved the effluent quality. Micropollutants were removed on average over 80% compared with raw wastewater, with an average ozone dose of 5.7 mg O₃ l⁻¹ or a PAC dose between 10 and 20 mg l⁻¹. Depending on the chemical properties of the substances (presence of electron-rich moieties, charge and hydrophobicity), either ozone or PAC performed better. Both advanced treatments led to a clear reduction in toxicity of the effluents, with PAC-UF performing slightly better overall. As both treatments had, on average, relatively similar efficiency, further criteria relevant to their implementation were considered, including local constraints (e.g., safety, sludge disposal, disinfection), operational feasibility and cost. For sensitive receiving waters (drinking water resources or recreational waters), the PAC-UF treatment, despite its current higher cost, was considered to be the most suitable option, enabling good removal of most micropollutants and macropollutants without forming problematic by-products, the strongest decrease in toxicity and a total disinfection of the effluent.

Einleitung: In der Schweiz werden im Rahmen der Aktivitäten der Koordinierten Beobachtung Oberflächengewässer (KBO) sowie des Vorgängerprojektes Modulstufenkonzept (MSK), standardisierte Methoden für die Untersuchung und Bewertung des Zustandes der Fliessgewässer erarbeitet, um so strukturelle, hydrologische, biologische, chemische sowie ökotoxikologische Aspekte der Wasserqualität zu erfassen und gegebenenfalls Massnahmen zur Verminderung dieser Belastung ergreifen zu können.
Zielsetzung des Moduls Ökotoxikologie innerhalb des MSK bzw. der KBO ist die Entwicklung eines, auf ökotoxikologischen Biotests basierenden, Konzeptes zur routinemässigen Beurteilung der Wasserqualität anhand von Biotests, bestehend aus Probenahme, Probenaufbereitung, Biotests und Beurteilung der Effekte. Die Biotests sollen sensitiv, wirkungsbasiert, einfach durchführbar, kostengünstig und gut interpretierbar sein.
In dem vorliegenden Bericht werden ausgewählte Testsysteme zur Detektion und Quantifizierung von Östrogenität in Wasserproben für eine Anwendung durch Vollzugsbehörden und private Labore evaluiert. [...]

Hormonaktive Stoffe, die vor allem über das Abwasser in Oberflächengewässer gelangen, können die Gesundheit von Wassertieren beeinträchtigen. Ökotoxikologische Testmethoden verbessern die Messbarkeit und Bewertung dieser Substanzen. Sie liefern wichtige Entscheidungshilfen für Massnahmen zur Verminderung des Eintrags der Stoffe. So lässt sich mit ihnen die Wirkung zusätzlicher Reinigungsstufen in den Kläranlagen evaluieren.

Östrogen wirksame Substanzen werden mit gereinigtem Abwasser in Fliessgewässer und Seen eingetragen. Im Auftrag des Kanton St. Gallen wurden 44 Abwasser- und 3 Gewässerproben mit dem YES (Yeast Estrogen Screen; Anhang 1) untersucht. In den nächsten Absätzen werden die methodischen Schritte zusammengefasst und die Resultate in einer Tabelle aufgeführt. In einem letzten Absatz werden YES-Werte aus der Literatur kurz beleuchtet.

Endocrine-disrupting compounds, which enter surface waters mainly via wastewater discharges, can have adverse effects on aquatic organisms. Ecotoxicological test methods improve the measurement of these substances and the assessment of water quality, providing valuable decision support for reduction measures. For example, these methods can be used to evaluate additional treatment steps at wastewater treatment plants.

Hormonaktive Stoffe, die vor allem über das Abwasser in Oberflächengewässer gelangen, können die Gesundheit von Wassertieren beeinträchtigen. Ökotoxikologische Testmethoden verbessern die Messung und Bewertung dieser Substanzen. Sie liefern wichtige Entscheidungshilfen für Massnahmen zur Verminderung. So lässt sich mit ihnen die Wirkung zusätzlicher Reinigungsstufen in den Kläranlagen evaluieren.

The goal of the FOEN project “Strategy Micropoll“ was to develop a strategy regarding micropollutants originating from wastewater. Besides an analysis of water quality in Switzerland and other aspects, this included the evaluation of the efficiency of complementary wastewater treatments such as ozonation followed by sand filtration (ozonation-SF) and different processes including powdered activated carbon addition (PAC) in eliminating micropollutants from wastewater treatment effluent. Two large-scale pilot studies were conducted at the wastewater treatment plants (WWTP) Wüeri in Regensdorf (ozonation followed by sand-filtration) and Vidy in Lausanne (ozonation followed by sandfiltration and PAC followed by ultrafiltration). The studies were done in close collaboration with experts from research, practice and with personnel and financial support of cantonal water protection agencies (Gewässerschutzfachstellen) and the operators of the WWTPs.
In both studies, samples before and after various treatment steps were analysed for micropollutants and ecotoxicological effects, in order to get insight into the efficiency of the different treatment steps. The focus laid on studying the effects of the advanced treatment technologies, ozonation and PAC, on the removal efficiency for polar, persistent and bioactive substances as well as possible side products and their biological effects. [...]

The evaluation of the toxicity of chemical agent mixtures poses important challenges for authorities, research and industry. In November 2010, the Ecotoxicology Centre, in collaboration with the SCAHT held a workshop with the aim of introducing the issue of chemical agent mixtures in the environment and in people and of providing an overview of the assessment of mixture toxicity based on various models. For this purpose, not only mixtures of various chemicals were examined, but also the interactions of chemicals with other abiotic stressors. The participants discussed the resulting regulatory challenges, the requirements for different sectors and formulated the need for action for the future.

The SETAC Europe Student Advisory Council (SAC) represents student members (master, diploma or Ph.D.) throughout every level of SETAC since 2006 and provides additional advice, recommendations, and new initiatives to the SETAC Europe Council. During this year’s SETAC Europe annual meeting in Gothenburg, Sweden, the SAC organized three student-oriented activities.

Micropollutants (MP) from municipal wastewater are frequently detected in surface waters and occur in ecotoxicological relevant concentrations. Therefore a broadly accepted method for the assessment of MP is needed. Here, we propose a procedure for the assessment of MP from municipal wastewater. The suggested method comprises (1) a substance list with relevant MP, (2) toxicologically based quality criteria, (3) an approach for the identification of potentially polluted sites, (4) a sampling strategy that considers the input-dynamics of chemicals and (5) a scheme to rate the water quality concerning MP. In the proposed concept the assessment of continuous entering substances is focused.

More than 4500 species belong to the crustacean sub-order Gammaridea (order Amphipoda (Bousfield 1973). Among Amphipods, the Gammaridea are the most widespread group and are found throughout a range of marine, freshwater, and terrestrial habitats (Bousfield 1973; Lincoln 1979), whereas the three other amphipod sub-orders (Hyperiidea, Ingolfiellidea, and Caprellidea) are highly specialized and ecologically restricted. Gammarus is the amphipod genus with the highest number of epigean freshwater species, comprising over 100 species that are distributed throughout the Northern Hemisphere (Karaman and Pinkster 1977). Abiotic factors such as temperature, salinity, oxygen, acidity, and pollution play an important role in the distribution of Gammarus species (Whitehurst and Lindsey 1990) and members of this species are often found in great abundance under rocks, in gravel, or in coarse substrates and among living and dead vegetation (Fitter and Manuel 1994). These substrata provide both shelter from predators and a supply of organic detritus and other foodstuffs, with the result that in many riverine communities, amphipod species such as Gammarus pulex (Linnaeus) may represent the dominant macroinvertebrate in terms of biomass (Macneil et al. 1997; Shaw 1979). [...]

The effects of chemicals on biotic interactions, such as competition and predation, have rarely been investigated in aquatic ecotoxicology. This study presents a new approach for the investigation of predator–prey interactions between zebrafish (Danio rerio) and midge larvae (Chironomus riparius) impaired by chlorpyrifos (CHP), a neurotoxic insecticide. With a simple experimental design including four different treatments: (1) control, (2) predator exposed, (3) prey exposed and (4) both, predator and prey, exposed, we were able to detect by visual observation an increase in the feeding rate of zebrafish preying on exposed chironomids after acute (2 h) exposure to 6 μg/l CHP. Previously, a decrease in the burrowing behaviour of exposed chironomid larvae was observed. However, when pre-exposing simultaneously both predators and prey, no significant differences in the feeding rate of zebrafish were observed. This suggests an impairment in prey recognition of the exposed zebrafish. At a lower CHP concentration (1 μg/l), no differences in feeding rate of zebrafish were observed. We therefore propose the use of trophic interactions as parameters in higher tier studies for chemical testing and evaluation of ecotoxicological risk assessment.

Silber und Nanosilber werden in vielen Produkten des täglichen Lebens als antimikrobieller Wirkstoff eingesetzt. So wird auch eine Farbprodukt für die Anwendung auf Gebäudefassa-den gegen den Befall von Mikroorganismen mit Nanosilber ausgerüstet. Dies kann durch Verwitterungsprozesse ausgewaschen werden. Zusammen mit den Abteilungen Siedlungs-wasserwirtschaft und Verfahrenstechnik der Eawag und der Abteilung Bautechnologien der Empa wurde die Auswaschung der Silberpartikel aus einer marktüblichen Fassadenfarbe untersucht. Das Ökotoxzentrum hat dabei den Fassadenablauf auf dessen ökotoxikologi-sches Potential hin untersucht. Es wurden unterschiedliche Biotests angewendet. Nebst in vivo Tests mit Gammarus fossarum und Ceriodaphnia dubia wurden Tests in Mikrotiterplat-ten durchgeführt, der Leuchtbakterientest mit Vibrio fischeri und der kombinierte Algentest mit Pseudokirchneriella subcapitata. [...]

The 1st Young Environmental Scientists (YES) Meeting took place in March (16–18) 2009 at the Institute for Environmental Sciences at the University of Koblenz-Landau, Landau Campus, Germany. This special students-only conference was organised under the umbrella of Society of Environmental Toxicology and Chemistry (SETAC) Europe by its Student Advisory Council (SAC). The SAC represents student members (master, diploma or Ph.D.) throughout every level of SETAC and provides additional advice, recommendations and new initiatives to the SETAC Europe Council.

Zur ökotoxikologischen Beurteilung des Sickerwassers einer Deponie wurden drei Testsysteme angewandt.
Um die Toxizität des Sickerwassers auf einzellige Grünalgen (planktonische Primärproduzenten) zu beurteilen, wurde ein kombinierter Algentest mit der Art Pseudokirchnerellia subcapitata durchgeführt. Ein akuter Toxizitätstest mit Bachflohkrebsen (Gammarus spp.), die als Zerkleinerer und Verwerter organischer Substanz (Destruenten) und als Beuteorganismus für Fische eine Schlüsselfunktion in Fliessgewässerökosystemen haben, diente zur Evaluation der Auswirkungen des Sickerwassers auf diese Organismen. Abschliessend wurden die chronischen Auswirkungen des Sickerwassers auf die Reproduktion und Mortalität der Cladocere Ceriodaphnia dubia untersucht, die als planktonischer Primärkonsument (u.a. von Grünalgen) und als wichtiger Beuteorganismus für Fische und andere Wasserlebewesen eine wichtige Rolle im stehenden Gewässerökosystem spielt.
Das Sickerwasser wies weder akut noch chronisch eine Toxizität gegenüber den Testorganismen auf.

In Zusammenarbeit mit den Abteilungen SWW (Siedlungswasserwirtschaft) und Verfahrenstechnik der Eawag wurde das Abwasser einer Wäscherei untersucht. Die Wäscherei gibt dem Waschmittel Nanosilber in Form von Silberchlorid zu, um sich die antimikrobiellen Eigenschaften von Silber zu Nutze zu machen. Die Abteilung SWW und Verfahrenstechnik ermitteln dabei u. a. die Austragungsmenge und das Verhalten von Nanosilber im Abwasser. Das Oekotoxzentrum untersuchte anhand von unterschiedlichen Biotests die Toxizität des komplexen Abwassers. Im kombinierten Algentest mit der einzelligen Grünalge Pseudokirchneriella subcapitata wurden die Inhibition der Photosynthese und des Wachstums untersucht. Der Leuchtbakterientest mit dem marinen Bakterium Vibrio fischeri zeigte durch eine Hemmung der Lichtemission eine allgemeine Toxizität an. Des Weiteren wurde ein in vivo Test mit dem Bachflohkrebs Gammarus fossarum durchgeführt, bei dem Auswirkungen des Abwassers auf Verhalten und Mortalität untersucht wurden. [...]