title: Mechanistic modelling of toxicokinetic processes within Myriophyllum spicatum.
abstract: Effects of chemicals are, in most cases, caused by internal concentrations within organisms which rely on uptake and elimination kinetics. These processes might be key components for assessing the effects of time-variable exposure of chemicals which regularly occur in aquatic systems. However, the knowledge of toxicokinetic patterns caused by time-variable exposure is limited, and gaining such information is complex. In this work, a previously developed mechanistic growth model of Myriophyllum spicatum is coupled with a newly developed toxicokinetic part, providing a model that is able to predict uptake and elimination of chemicals, as well as distribution processes between plant compartments (leaves, stems, roots) of M. spicatum. It is shown, that toxicokinetic patterns, at least for most of the investigated chemicals, can be calculated in agreement with experimental observations, by only calibrating two chemical- specific parameters, the cuticular permeability and a plant/water partition coefficient. Through the model-based determination of the cuticular permeabilities of Isoproturon, Iofensulfuron, Fluridone, Imazamox and Penoxsulam, their toxicokinetic pattern can be described with the model approach. For the use of the model for predicting toxicokinetics of other chemicals, where experimental data is not available, equations are presented that are based on the log (P oct/wat) of a chemical and estimate parameters that are necessary to run the model. In general, a method is presented to analyze time-variable exposure of chemicals more in detail without conducting time and labour intensive experiments.
authors.affiliation: Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany. Electronic address: simon.heine@bio5.rwth-aachen.de.
authors.forename: S
authors.initials: S
authors.lastname: Heine
authors.affiliation: Bayer Crop Science AG, Alfred-Nobel-Straße 50, 40789 Monheim am Rhein, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Schmitt
authors.affiliation: Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Schäffer
authors.affiliation: Bayer Crop Science AG, Alfred-Nobel-Straße 50, 40789 Monheim am Rhein, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Görlitz
authors.affiliation: Department of Environmental Chemistry, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Praha 6, Czech Republic.
authors.forename: H
authors.initials: H
authors.lastname: Buresová
authors.affiliation: Alterra, Wageningen University and Research Centre, P.O. Box 47, 6700 AA Wageningen, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Arts
authors.affiliation: Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
authors.forename: T G
authors.initials: TG
authors.lastname: Preuss
mesh_terms: D019684:Magnoliopsida / Q000187:drug effects* / Q000378:metabolism*; D008962:Models, Theoretical; D066007:Toxicokinetics; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Modelling; Myriophyllum spicatum; Risk assessment; Time-variable exposure; Toxicokinetics