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.

Towards an optimal coverage of ecosystem services in LCA

“…To reach a compromise between the need for spatial differentiation for ES and the practical limitations of LCA, we propose further research to focus around the use of archetypes (see for example Gandhi et al, 2011bGandhi et al, , 2011aKounina et al, 2014) to develop spatially differentiated characterization factors that can be linked with background processes. Most background processes are categorized at a maximum geographical resolution of country level.…”

“…However, biographical variations can be reflected with the use of archetypes by assigning each country to an archetype category, and therefore reducing the number of spatial categories needed for the assessment of ES. Archetypes can take into account environmental and socioeconomic factors to have a more accurate representation of the studied system (Kounina et al, 2014;V aclavík et al, 2013). The use of archetypes would allow estimating impacts on ES also for background processes, increasing the applicability of newly proposed indicators.…”

Life cycle assessment of tailings management options: a conceptual case study in Western Australia

“…LCIA was performed using various midpoint impact categories drawn from four different impact assessment methods: Global Warming Potential (GWP) (Solomon et al 2007), CML-IA (Guinée 2002), TRACI (Bare 2002), and USEtox (Kounina et al 2014) methods. These impact assessment methods, along with the selected midpoint impact categories, were chosen because they were recommended by the Australian Life Cycle Assessment Society (ALCAS) for LCA studies centred on Australian products and processes in the document entitled Best Practice Guide for Mid-Point Life Cycle Impact Assessment in Australia (Renouf et al 2018).…”

Vers une évaluation absolue de la durabilité écologique : quelle variabilité des valeurs de référence associées à l'écotoxicité aquatique ?

“…(iii) Les conditions de dispersion des polluants (en rouge sur la figure 1) : Les conditions météorologiques, les propriétés physico-chimiques des eaux sont des paramètres affectant la sensibilité des milieux vis-à-vis des pressions écotoxiques. (Kounina et al, 2014) ont développé des facteurs de caractérisation spatialement différenciés à partir de la méthode USEtox. Cette contextualisation de l'impact écotoxique peut être faite à travers l'application des facteurs de caractérisation spatialisés lors de l'EICV.…”