title: Spatial analysis of toxic emissions in LCA: a sub-continental nested USEtox model with freshwater archetypes.
abstract: This paper develops continent-specific factors for the USEtox model and analyses the accuracy of different model architectures, spatial scales and archetypes in evaluating toxic impacts, with a focus on freshwater pathways. Inter-continental variation is analysed by comparing chemical fate and intake fractions between sub-continental zones of two life cycle impact assessment models: (1) the nested USEtox model parameterized with sub-continental zones and (2) the spatially differentiated IMPACTWorld model with 17 interconnected sub-continental regions. Substance residence time in water varies by up to two orders of magnitude among the 17 zones assessed with IMPACTWorld and USEtox, and intake fraction varies by up to three orders of magnitude. Despite this variation, the nested USEtox model succeeds in mimicking the results of the spatially differentiated model, with the exception of very persistent volatile pollutants that can be transported to polar regions. Intra-continental variation is analysed by comparing fate and intake fractions modelled with the a-spatial (one box) IMPACT Europe continental model vs. the spatially differentiated version of the same model. Results show that the one box model might overestimate chemical fate and characterisation factors for freshwater eco-toxicity of persistent pollutants by up to three orders of magnitude for point source emissions. Subdividing Europe into three archetypes, based on freshwater residence time (how long it takes water to reach the sea), improves the prediction of fate and intake fractions for point source emissions, bringing them within a factor five compared to the spatial model. We demonstrated that a sub-continental nested model such as USEtox, with continent-specific parameterization complemented with freshwater archetypes, can thus represent inter- and intra-continental spatial variations, whilst minimizing model complexity.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland; Quantis, Parc scientifique EPFL, Bâtiment D, 1015 Lausanne, Switzerland. Electronic address: anna.kounina@quantis-intl.com.
authors.forename: Anna
authors.initials: A
authors.lastname: Kounina
authors.affiliation: Quantis, Parc scientifique EPFL, Bâtiment D, 1015 Lausanne, Switzerland; CIRAIG, Polytechnique of Montréal, Chemin Polytechnique Montréal, QC, Canada.
authors.forename: Manuele
authors.initials: M
authors.lastname: Margni
authors.affiliation: University of Michigan, School of Public Health, Environmental Health Sciences, Ann Arbor, MI 48109, USA.
authors.forename: Shanna
authors.initials: S
authors.lastname: Shaked
authors.affiliation: CIRAIG, Polytechnique of Montréal, Chemin Polytechnique Montréal, QC, Canada.
authors.forename: Cécile
authors.initials: C
authors.lastname: Bulle
authors.affiliation: Quantis, Parc scientifique EPFL, Bâtiment D, 1015 Lausanne, Switzerland; University of Michigan, School of Public Health, Environmental Health Sciences, Ann Arbor, MI 48109, USA.
authors.forename: Olivier
authors.initials: O
authors.lastname: Jolliet
mesh_terms: D004781:Environmental Exposure / Q000032:analysis*; D004785:Environmental Pollutants / Q000032:analysis*; D005060:Europe; D005618:Fresh Water / Q000032:analysis*; D005843:Geography; D015386:Hazardous Substances / Q000032:analysis*; D008962:Models, Theoretical; D062206:Spatial Analysis; D013997:Time Factors
chemical_list: D004785:Environmental Pollutants; D015386:Hazardous Substances
keywords: Archetypes; Ecotoxicity; Human toxicity; Life Cycle Assessment; Spatial differentiation; USEtox