Background Document on Effect-Based Trigger Values for Environmental Water Quality
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TOXICOLOGY TRACK ECOLOGISCHE SLEUTELFACTOR TOXICITEIT 1 TOXICOLOGY TRACK ECOLOGICAL KEY FACTOR TOXICITY Part 5 Background document on effect-based trigger values for environmental water quality ECOLOGISCHE SLEUTELFACTOR TOXICITEIT 2 TOXICOLOGY TRACK COLOPHON Amersfoort, September 2016 Publisher Stichting toegepast Onderzoek Waterbeheer, Postbus 2180, 3800 CD Amersfoort Authors Ron van der Oost (Waternet), Giulia Sileno (Waternet), Maria Suárez Muñoz (UvA-IBED). Guidance group Renée Talens (STOWA), Bas van der Wal (STOWA), Anke Durand-Huiting (Waterschap Vechtstromen), Roelof Veeningen (Wetterskip Fryslân), Miriam Col- lombon (Wetterskip Fryslân), Frans de Bles (Waterschap Vallei en Veluwe), Roel Knoben (Royal Haskoning DHV), Anja Derksen (ADeco advies), Laura Moria (Waternet), Dick de Zwart (RIVM, DdZ Ecotox), Leonard Osté (Deltares), Leo Postuma (RIVM), Jaap Postma (Ecofide), Jos Goossen (Waterschap Scheldestromen), Ernst Raaphorst (Hoogheemraadschap van Delfland). Abstract STOWA developed the conceptual framework of the Ecological Key Factors for the ecological assessment of water quality issues. The key factors describe precondi- tions for good water quality. The key factors help to structure the available information of water quality and make it possible to pinpoint dominant processes in water system functioning. Understanding of the water quality functioning enables identification of effective restoration measures. Toxicity has been identified as one of the Ecological Key Factors. As part of water quality assessment with EKFs an evaluation should be made to assess whether the water system complies with the key factor toxicity. In a serie of five reports the methodology to assess whether the water quality complies with the ecological key factor toxicity has been described. The methodology gives insight in the effect of chemical compounds on the biology. This report is part 5 and is a background document on effect-based trigger values (EBT’s) for the assessment of the ecological risks of (a combination of) compounds. The EBT’s are used in the SIMONI model which can be applied to assess the chemical waterquality. Keywords Ecological Key Factors, watersystemanalysis, toxicity, ecological impact assessment, bioassays, effect based trigger values, SIMONI Edited by Marloes van der Kamp (STOWA) Lay out and graphic design Shapeshifter, Utrecht STOWA 2016-15 E WATERNET 15.125832 C ISBN 978.90.5773.727.5 Copyright No part of this report may be reproduced without correct citation. Disclaimer The content of this publication has been prepared with care and is based on the most recent insights within the research area. STOWA and the authors are not liable for any mistakes in the report and consequences arising from the application of the knowledge that is described in this report. ECOLOGISCHE SLEUTELFACTOR TOXICITEIT 3 TOXICOLOGY TRACK SUMMARY STOWA developed the conceptual framework of the Ecological Key Factors for the ecological assessment of water quality issues. The key factors describe preconditions for good water quality. The key factors help to structure the available infor- mation of water quality and make it possible to pinpoint dominant processes in water system functioning. Understanding of the water quality functioning enables identification of effective restoration measures. Toxicity has been identified as one of the Ecological Key Factors. There are key factors for stagnant and streaming waterbodies. The Ecological Key Factor toxicity is applicable for both types. In a serie of five reports the Ecological Key Factor toxicity is elaborated. The serie contains a main report and 4 attach- ments. This report is part 5 and is a background document on effect-based trigger values for the assessment of the ecological risks of (a combination of) chemicals. The concept is part of the toxicology track described in part 1. Part 4 describes the procedures for monitoring. Aquatic life is subjected to stress due to the release of thousands of chemicals in the water, but it remains hard to de- termine the ecological actual risks. A paradigm shift in the field of water quality assessment from a single-chemical ap- proach to an effect-based approach would overcome the limitations connected with the current monitoring strategies. Chemical analyses can be conducted only on a limited set of known chemicals and it is virtually impossible to assess mixture toxicity of such complex mixtures. Bioanalytical tools, in combination with chemical analyses, can be a valid alternative to classic monitoring programs. Such an integrated approach would provide information regarding the overall impact of co-exposure to multiple chemicals (known and unknown) on different levels of biological organization. This study aimed to design environmental effect-based trigger values (EBT) for a selection of bioassays. The aim of these EBTs is that they should provide initial hazard identification of organic micropollutants for the aquatic organisms. The EBTs will be included in a model called “SIMONI” (Smart Integrated MONItoring) that can be used to discriminate between ‘low risk’ sites, where no further analyses are needed, and ‘potential risk’ sites, where an additional risk assessment has to be conducted. The goal is to reduce monitoring costs, and meanwhile generate a more complete analysis of the chemical water quality by using a battery of bioassays covering the most relevant modes of toxicant action. A three-step approach was used to design effect-based trigger values (EBT). A selection of compounds was made that have a known response in the bioassay, with relative effect potencies (REPs) close to the reference compound for that assay. The first step was a literature search for toxicity data on these selected compounds, and conversion to their TEQ values (toxic equivalents of the respective reference compounds). Lowest TEQs of all toxic effects found (divided by an assessment fac- tor) will be used as ‘save TEQ’. The second step was a species sensitivity distribution of all TEQ values in order to estimate the TEQ level that may cause an adverse effect to 5% of the species (HC5 TEQ). The HC5 TEQ should preferably be higher than or equal to the proposed low-risk effect-based trigger value (EBT). The final step was a benchmark with Waternet field data. The average bioassay responses at eight ecologically clean sites were considered as ‘clean TEQ’. A realistic EBT was derived that should be higher than the average effect observed at eight reference sites with a good ecological status. In order to get a good discrimination between sites, the EBT should be exceeded only at a limited number of seriously pol- luted sites. Therefore, further validation studies will be needed to optimize the proposed trigger values in the near future. ECOLOGISCHE SLEUTELFACTOR TOXICITEIT 4 TOXICOLOGY TRACK Effect-based trigger values were derived for: - estrogenic activity (Era CALUX): 0.5 ng EEQ/L; - anti-androgenic activity (anti-AR CALUX): 25 µg F1EQ/L; - glucocorticoid activity (GR CALUX): 100 ng DEQ/L; - dioxin-like activity (DR CALUX): 50 pg TEQ/L; - PPARγ receptor activity (PPARγ CALUX): 10 ng REQ/L; - toxic PAHs activity (PAH CALUX): 150 ng BEQ/L; - oxidative stress (Nrf2 CALUX): 10 µg CEQ/L; - pregnane X receptor activity (PRX CALUX): 3 µg N1EQ/L; - five classes of antibiotics activity (RIKILT WaterSCAN): - aminoglycosides activity: 500 ng N2EQ/L; - macrolides & β lactams activity: 50 ng PEQ/L; - sulphonamides activity: 100 ng SEQ/L; - tetracyclines activity: 250 ng OEQ/L; - quinolones activity: 100 ng F2EQ/L. It is essential to propose better monitoring strategies in order to preserve the quality of freshwater environment. The in- troduction of bioassays in monitoring programs can lead to a more sustainable water quality assessment. This study may provide a reference for further measures and implementation of risk assessment of micropollutants in the water cycle. ECOLOGISCHE SLEUTELFACTOR TOXICITEIT 5 TOXICOLOGY TRACK TABLE OF CONTENTS Colophon .............................................................................................................................................2 3 Summary 4 Table of contents ..................................................................................................................................1 6 ..........................................................................................................................................................4 1 INTRODUCTION ..........................................................................................................................11 8 1.1 Ecological key factors .......................................................................................................... 11 8 1.2 Effects of Chemicals ............................................................................................................ 11 8 1.3 In vitro bioasSay battery ..................................................................................................... 15 11 1.4 Aim of the study ................................................................................................................ 19 13 2 METHODS .................................................................................................................................21 15 2.1 Toxicological Database ........................................................................................................ 22 16 2.2 Safe Approach (safe teq) ....................................................................................................