title: Modelling survival: exposure pattern, species sensitivity and uncertainty.
abstract: The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans.
authors.affiliation: Environment Department, University of York, Heslington, York YO10 5NG, United Kingdom.
authors.forename: Roman
authors.initials: R
authors.lastname: Ashauer
authors.affiliation: Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Überlandstrasse 133, Switzerland.
authors.forename: Carlo
authors.initials: C
authors.lastname: Albert
authors.affiliation: Akvaplan-niva, Fram - High North Research Centre for Climate and the Environment, 9296 Tromsø, Norway.
authors.forename: Starrlight
authors.initials: S
authors.lastname: Augustine
authors.affiliation: Department of Plant and Environmental Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark.
authors.forename: Nina
authors.initials: N
authors.lastname: Cedergreen
authors.affiliation: Univ Lyon, Université Lyon 1, UMR CNRS 5558, Laboratoire de Biométrie et Biologie Évolutive, F-69100 Villeurbanne, France.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Charles
authors.affiliation: Bayer CropScience Aktiengesellschaft, BCS AG-R&D-D-EnSa-ETX-AQ, Monheim, Deutschland.
authors.forename: Virginie
authors.initials: V
authors.lastname: Ducrot
authors.affiliation: Alterra, Wageningen University and Research centre, P.O. Box 47, 6700 AA, The Netherlands.
authors.forename: Andreas
authors.initials: A
authors.lastname: Focks
authors.affiliation: RIFCON GmbH, Goldbeckstraße 13, 69493 Hirschberg, Germany.
authors.forename: Faten
authors.initials: F
authors.lastname: Gabsi
authors.affiliation: Research Institute for Ecosystem Analysis and Assessment (gaiac), Kackertstrasse 10, 52072, Aachen, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Gergs
authors.affiliation: Environment Department, University of York, Heslington, York YO10 5NG, United Kingdom.|Safety and Environmental Assurance Centre, Colworth Science Park, Unilever, Sharnbrook, Bedfordshire, United Kingdom.
authors.forename: Benoit
authors.initials: B
authors.lastname: Goussen
authors.affiliation: DEBtox Research, De Bilt, The Netherlands.
authors.forename: Tjalling
authors.initials: T
authors.lastname: Jager
authors.affiliation: Utrecht University, Institute for Risk Assessment Sciences (IRAS), 3584 Utrecht, Netherlands.
authors.forename: Nynke I
authors.initials: NI
authors.lastname: Kramer
authors.affiliation: European Chemicals Agency, Annankatu 18, FI-00121, Helsinki, Finland.
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Nyman
authors.affiliation: French Agency for Food, Environmental and Occupational Health Safety (ANSES), Regulated Product Assessment Directorate, 14 rue Pierre et Marie Curie 94704 Maisons Alfort, France.
authors.forename: Veronique
authors.initials: V
authors.lastname: Poulsen
authors.affiliation: Dr. Knoell Consult GmbH, Dynamostr. 19, 68165 Mannheim, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Reichenberger
authors.affiliation: Institute for Environmental Sciences, University Koblenz-Landau, Fortstraße 7, 76829 Landau, Germany.
authors.forename: Ralf B
authors.initials: RB
authors.lastname: Schäfer
authors.affiliation: Alterra, Wageningen University and Research centre, P.O. Box 47, 6700 AA, The Netherlands.|Department of Aquatic Ecology and Water Quality Management, Wageningen University, Wageningen University and Research centre, P.O. Box 47, 6700 AA, The Netherlands.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Van den Brink
authors.affiliation: Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan 48109-2029, USA.
authors.forename: Karin
authors.initials: K
authors.lastname: Veltman
authors.affiliation: Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Überlandstrasse 133, Switzerland.
authors.forename: Sören
authors.initials: S
authors.lastname: Vogel
authors.affiliation: Ibacon GmbH, Arheilger Weg 17, 64380 Roßdorf, Germany.
authors.forename: Elke I
authors.initials: EI
authors.lastname: Zimmer
authors.affiliation: Bayer CropScience Aktiengesellschaft, BCS AG-R&D-D-EnSa-Emod, Monheim, Germany.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Preuss