title: Importance of environmental and biomass dynamics in predicting chemical exposure in ecological risk assessment.
abstract: In ecological risk assessment, exposure is generally modelled assuming static conditions, herewith neglecting the potential role of emission, environmental and biomass dynamics in affecting bioavailable concentrations. In order to investigate the influence of such dynamics on predicted bioavailable concentrations, the spatially-resolved dynamic model "ChimERA fate" was developed, incorporating macrophyte and particulate/dissolved organic carbon (POC/DOC) dynamics into a water-sediment system. An evaluation against three case studies revealed a satisfying model performance. Illustrative simulations then highlighted the potential spatio-temporal variability of bioavailable concentrations after a pulsed emission of four chemicals in a system composed of a pond connected to its inflow and outflow streams. Changes in macrophyte biomass and POC/DOC levels caused exposure variations which were up to a factor of 4.5 in time and even more significant (several orders of magnitude) in space, especially for highly hydrophobic chemicals. ChimERA fate thus revealed to be a useful tool to investigate such variations and to identify those environmental and ecological conditions in which risk is expected to be highest.
authors.affiliation: Department of Science and High Technology, University of Insubria, Via Valleggio 11, 22100 Como, CO, Italy.
authors.forename: Melissa
authors.initials: M
authors.lastname: Morselli
authors.affiliation: Dipartimento di Matematica, Università degli Studi di Torino, Via C. Alberto 10, 10123 Torino, TO, Italy.
authors.forename: Matteo
authors.initials: M
authors.lastname: Semplice
authors.affiliation: University of Namur, Research Unit in Environmental and Evolutionary Ecology, Rue de Bruxelles 61, 5000 Namur, Belgium.
authors.forename: Frederik
authors.initials: F
authors.lastname: De Laender
authors.affiliation: Alterra, Wageningen University and Research Centre, P.O. box 47, 6700 AA Wageningen, The Netherlands; Department of Aquatic Ecology and Water Quality Management, Wageningen University, 6700 AA Wageningen, The Netherlands.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Van den Brink
authors.affiliation: Department of Science and High Technology, University of Insubria, Via Valleggio 11, 22100 Como, CO, Italy. Electronic address: antonio.diguardo@uninsubria.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Di Guardo
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D018533:Biomass; D017753:Ecosystem; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D061005:Ponds / Q000737:chemistry; D018570:Risk Assessment / Q000379:methods; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Bioavailability; ChimERA; Dynamic exposure; Fate modelling; Organic chemical; Surface water