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

Calibration and use of the polar organic chemical integrative sampler-a critical review

The implementation of strict environmental quality standards for polar organic priority pollutants poses a challenge for monitoring programs. The polar organic chemical integrative sampler (POCIS) may help to address the challenge of measuring low and fluctuating trace concentrations of such organic contaminants, offering significant advantages over traditional sampling. In the present review, the authors evaluate POCIS calibration methods and factors affecting sampling rates together with reported environmental applications. Over 300 compounds have been shown to accumulate in POCIS, including pesticides, pharmaceuticals, hormones, and industrial chemicals. Polar organic chemical integrative sampler extracts have been used for both chemical and biological analyses. Several different calibration methods have been described, which makes it difficult to directly compare sampling rates. In addition, despite the fact that some attempts to correlate sampling rates with the properties of target compounds such as log KOW have been met with varying success, an overall model that can predict uptake is lacking. Furthermore, temperature, water flow rates, salinity, pH, and fouling have all been shown to affect uptake; however, there is currently no robust method available for adjusting for these differences. Overall, POCIS has been applied to a wide range of sampling environments and scenarios and has been proven to be a useful screening tool. However, based on the existing literature, a more mechanistic approach is required to increase understanding and thus improve the quantitative nature of the measurements. © 2012 SETAC

Estrogenicity patterns in the Swiss midland river Lützelmurg in relation to treated domestic sewage effluent discharges and hydrology

Sewage treatment works (STW) discharge estrogenic effluent into rivers, which leads to variable estrogenicity of river water. Here, we characterize how the factors effluent and hydrology influence the estrogenicity of river water. We selected a river for which good hydrological data are available and collected water samples upstream and downstream from a STW discharge; effluent was sampled as well. Sampling took place during four 12-d periods, associated with the seasons, and always occurred in the morning. We also investigated the estrogenicity along the river, both by grab sampling and by passive sampling. Estrogens were analyzed by a recombinant yeast assay (YES); the estrogenicity of a sample was equated to the 17beta-estradiol standard of the YES (ng/L). Estrogenicity upstream from the STW was mostly close to the detection limit of the YES (maximum, 0.4 ng/L). Estrogenicity of effluent ranged between 0.2 and 7.7 ng/L; lower estrogenicity was associated with higher hydraulic retention times. Downstream from the STW, estrogenicity exceeded 1 ng/L on 25% of the days (maximum, 2.1 ng/L). Measured river water estrogenicity correlated positively and significantly with predicted estrogenicity based on effluent estrogenicity and effluent dilution factor. Grab samples taken along the river indicate that no significant sources of estrogens were upstream from the STW; downstream from the STW, the pattern of estrogenicity was highly variable. However, passive sampling showed that the estrogenicity of river water downstream from the STW decreased continuously with increasing distance from the STW, which is largely explained by dilution

Comparative Evaluation of the Polar Organic Chemical Integrative Sampler (POCIS) in Two Types of Validation Systems

Polar organic chemical integrative sampler (POCIS) devices have been suggested for monitoring contaminant fluctuations in aquatic environments, resulting from chemical leak accidents. However, the response of the POCIS device in the emergency condition in natural water remains unclear. The response of the POCIS device to contaminant fluctuation was investigated using a simplified chamber test with tap water and a channel test with natural water in the present study. The fluctuation in the chamber and the channel replicated the condition of river water under a chemical leak scenario (maximum concentration: 1–10 μg L–1, half-life: 1 d). The target chemicals were neonicotinoid pesticides (dinotefuran, clothianidin, thiamethoxam, imidacloprid, acetamiprid, and thiacloprid) and bisphenol A. The ratio of the POCIS measured value to the time-weighted average value of grab samplings (POCIS/TWA) for the channel test (temperature: 15 °C, flow velocity: 15 cm s–1) ranged from 61% (clothianidin) to 133% (thiacloprid). The results indicated that the POCIS device could be effectively used as a monitoring device in an aquatic environment under the chemical leak scenario. In addition, the differences in the POCIS/TWA ratios obtained from the chamber test and the channel test were in the range of –50 to 50%, except for a few data points. Thus, the simplified chamber test could be used as a validation system to evaluate the POCIS device at a low cost.</p

Estrogenic activity of food contact materials : evaluation of 20 chemicals using a yeast estrogen screen on HPTLC or 96-well plates

Food contact materials (FCM) may contain complex mixtures of estrogenic chemicals. A yeast estrogen screen performed on high performance thin-layer chromatography plates (planar-YES, P-YES) is promising for analysis of such mixtures, as it could allow for better elucidation of effects compared with established methods in microtiter plates. However, the P-YES has not been directly compared with established methods. We compared the performance of a microtiter plate YES (lyticase-YES, L-YES) to P-YES on silica gel HPTLC plates using 17β-estradiol (E2), 20 chemicals representative of migrants from plastic FCM, and three migrates of coated metal food cans. Effective doses (ED10, ED50) and estradiol equivalencies were calculated for each chemical. Thirteen chemicals had calculable EDs in the L-YES or P-YES, with average EDs 13-fold (range 0.63–36) more potent in P-YES than in the L-YES. Normalized to E2, the median estrogenicity was within 1.5-fold (0.43–8.8) between the assays. Therefore, P-YES was as or more sensitive than L-YES but potencies relative to E2 were comparable between assays. With chromatography, the P-YES detected estrogenicity in coated metal cans, effects that were unmeasurable in L-YES. With the sample preparation methods used in this study, both YES assays are sufficiently sensitive to detect bisphenol A below the specific migration limit for plastic packaging (0.05 mg/kg food). This study demonstrates that P-YES outperforms L-YES because it is more sensitive, provides comparable estradiol equivalents, and circumvents confounding mixture effects. The P-YES will be useful for routine monitoring of FCM and toxicant identification in problematic materials

Monitoring of the ecotoxicological hazard potential by polar organic micropollutants in sewage treatment plants and surface waters using a mode-of-action based test battery

We propose and evaluate a mode-of-action based test battery of low-complexity and in-vitro bioassays that can be used as a routine monitoring tool for sewage treatment efficiency and water quality assessment. The test battery comprises five bioassays covering five different modes of toxic action. The bioluminescence inhibition test with Vibrio fischeri and a growth rate inhibition test with the green algae Pseudokirchneriella subcapitata are measures of non-specific integrative effects. A second endpoint in the algae test, the specific inhibition of the efficiency of photosynthesis, gives an account of the presence of herbicides. An enzymatic assay covers an important aspect of insecticidal activity, the inhibition of the acetylcholine esterase activity. Estrogenic effects are assessed with the yeast estrogen screen (YES) and genotoxicity with the umuC test. Three field studies, each lasting six to seven consecutive days, were undertaken at a sewage treatment plant (STP) in Switzerland. Samples were collected in summer and late autumn, under dry and rainy conditions. None of the bioassays gave positive results with raw water in whole effluent toxicity testing. Therefore, water samples from various sites during wastewater treatment and from surface water were enriched with solid-phase extraction. The focus was on non-volatile compounds of average to moderate hydrophobicity, a range that includes most pesticides, biocides and pharmaceuticals. Various polar solid phases were evaluated for their extraction efficiency, disturbance by matrix components and overall performance. We finally selected a mixture of a polymeric sorbent and a C18-sorbent, Lichrolut EN and RP-18 or, alternatively, Empore SDB-RPS disks. All bioassays gave clear and robust responses with the SPE extracts. With the bioassay data the treatment efficiency of the STP can be assessed with respect to different modes of toxic action and accordingly different groups of micropollutants. Furthermore, the data allowed for a comparison between the effluent and the receiving river. In all bioassays the primary effluent had a strong effect and this effect was reduced after passing the STP. Treatment efficiency was high (typically over 90%) but varied from bioassay to bioassay, which is expected because each bioassay detects different types of micropollutants and therefore we cannot expect a common answer

Effects of treated wastewater on the ecotoxicity of small streams - Unravelling the contribution of chemicals causing effects.

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 (EEQbio, 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 (DEQbio) 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 (PtEQbio) concentrations (indicating the degree of AChE inhibition) reached relatively high values (37 to 1278 ng/L) mostly exceeding the corresponding EBT (196 ng/L PtEQbio). 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

Evaluation of Three ISO Estrogen Receptor Transactivation Assays Applied to 52 Domestic Effluent Samples

Estrogens are released to the aquatic environment by wastewater treatment plant (WWTP) effluents and can affect wildlife. In the last three decades, many in vitro assay platforms have been developed to detect and quantify estrogenicity in water. In 2018, the International Organization for Standardization (ISO) standardized protocols became available for three types of in vitro estrogen receptor transactivation assays (ERTAs) detecting estrogenicity in 96-well plates (ISO19040 1-3). Two ERTAs-lyticase Yeast Estrogen Screen (L-YES) and Arxula YES (A-YES)-use genetically modified yeast strains, whereas the third utilizes stably transfected human cells. One human cell based assay is ER alpha-CALUX, which is based on a genetically modified human bone osteosarcoma cell line. In the present study, we characterized the performance, comparability, and effectiveness of these three ERTAs, including an evaluation involving proposed water quality thresholds (effect-based trigger values [EBTs]). For a robust evaluation, we collected 52 effluent samples over three sampling campaigns at 15 different WWTPs in Switzerland. Estrogen receptor transactivation assay results were correlated and compared with results from chemical analysis targeting known estrogens. The three ERTAs showed comparable data over all campaigns. However, the selection of EBTs plays a significant role in the interpretation and comparison of bioassay results to distinguish between acceptable and unacceptable water quality. Applying a fixed cross-assay EBT for effluent of 4 ng L-1 resulted in varying numbers of threshold exceedances ranging between zero and four samples depending on the ERTA used. Using assay-specific EBTs showed exceedances in eight samples (ER alpha-CALUX) and in one sample (A-YES), respectively. Thus, proposed EBTs do not produce similar risk profiles across samples and further refinement of assay-specific EBTs is needed to account for assay-specific differences and to enable the application of ERTAs as effect-based methods in environmental monitoring. Environ Toxicol Chem 2022;00:1-15. (c) 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.ISSN:0277-2248ISSN:1029-0486ISSN:0092-986

Estrogens in Swiss rivers and effluents: Sampling matters

Estrogenic activity of treated sewage effluents and receiving waters surfaced as an issue of general concern some 15 years ago. Since then, a large number of studies investigated the distribution and nature of the estrogenic substances in various aquatic ecosystems. Within NRP50, a five-year Swiss research programme on endocrine disruptors, four field studies were performed to characterize the presence of environmental estrogens in rivers and effluents. The estrogenic activity was quantified with a biological assay - the yeast estrogen screen. An overview of the sampling approaches and results of the various studies is presented here. In a first study, using grab sampling, it appeared that estrogenic activity in river water was highly variable. Average estrogenicity values did not correlate with sewage treatment works and/or river characteristics, e.g. effluent dilution factor. However, variability was not 'random' but clearly associated with river size, and possibly its discharge. A second study specifically addressed this issue of variability of estrogenicity. The study was conducted at a single effluent source and its receiving river. Variability of estrogenicity in the grab samples was again large but again not 'random'; some of the variability was explained by the time over which the effluent resided in the treatment process. In a third study it was explored if passive sampling would be a better way to assess average estrogenicity. Indeed, passive samplers identified sources of estrogens, and passive sampling data correlated well with both repeated grab sampling and bioaccumulation data. Subsequently, passive samplers were deployed across Switzerland in a fourth study. It involved 22 effluent discharges and the associated rivers. Data analysis of the last study is still ongoing, preliminary observations are discussed here. Although a lot could be learned from repeated grab sampling campaigns, it emerged that passive sampling is a very effective and appropriate technique to assess: i) effluent treatment efficiency, and ii) the chemical load of river water. For these reasons it is a valuable monitoring tool for water quality criteria assessments as well as for studies that aim to link exposure and effect. The passive samplers that are currently available not only target estrogenic substances, but many other polar organic compounds of concern, such as antibiotics (see NRP49), other pharmaceuticals and biocides

Assessment of estrogenic exposure in brown trout (Salmo trutta) in a Swiss midland river : integrated analysis of passive samplers, wild and caged fish, and vitellogenin mRNA and protein

This field study examined the vitellogenin (VTG) biomarker response under conditions of low and fluctuating activities of environmental estrogenicity. The present study was performed on immature brown trout (Salmo trutta) exposed to the small river Luetzelmurg, which is located in the prealpine Swiss midland region and receives effluents from a single sewage treatment plant (STP). To understand better factors influencing the relationship between estrogenic exposure and VTG induction, we compared VTG levels in caged (stationary) and feral (free-ranging) fish, VTG levels in fish from up- and downstream of the STP, and two different methods for quantifying VTG (enzyme-linked immunosorbent assay vs real-time reverse transcription-polymerase chain reaction), and we used passive samplers (polar organic chemical integrative sampler [POCIS]) to integrate the variable, bioaccumulative estrogenic load in the river water over time. The POCIS from the downstream site contained approximately 20-fold higher levels of bioassay-derived estrogen equivalents than the POCIS from the upstream site. In feral fish, this site difference in estrogenic exposure was reflected in VTG protein levels but not in VTG mRNA. In contrast, in caged fish, the site difference was evident only for VTG mRNA but not for VTG protein. Thus, the outcome of VTG biomarker measurements varied with the analytical detection method (protein vs mRNA) and with the exposure modus (caged vs feral). Our findings suggest that for environmental situations with low and variable estrogenic contamination, a multiple-assessment approach may be necessary for the assessment of estrogenic exposure in fish