Building a LEZ scenario and its social and environmental impacts in the Greater Paris area
Authors: Costes Malo , Elessa Etuman Arthur , Benoussaïd Taos , Coll Isabelle 
Published: February 2023

The urban environment has a large population and therefore a large number of polluting activities. Urban organization and the organization of road traffic are levers for controlling energy consumption, transport demand, air quality and the exposure of city dwellers, but these initiatives have social repercussions that do not impact all citizens in the same way, which may create a form of social and environmental injustice. Modeling of urban development scenarios should make it possible to investigate these questions. The challenges of such scenarios lie in the difficulty of modeling a given situation at the level of individuals by taking into account their socio-demographic characteristics, their places of life and their mobility behaviors.In 2017, a Low Emission Zone (LEZ) has been implemented in the Paris Metropolis, including the city of Paris and the nearby municipalities. The objective is to reduce pollutant emissions and improve air quality in the territory. Recent studies have assessed the average health impact expected from such measures, but they did not consider socio-environmental outcomes. In our work, we thus decided to build a complete LEZ scenario considering the mobility of individuals differentiated by their geographic, demographic and socio-professional specificites.The urban modeling platform that we use is centered on the OLYMPUS tool, which makes it possible to design mobility scenarios and the associated pollutant emissions by taking into account the urban form, the transport offer, the constraints of land use planning as well as than individual and socially differentiated mobility. With this tool we built different forms for the implementation of the Greater Paris LEZ, and we used the resulting emissions in the CHIMERE air quality model.We present here the methodology implemented to transcribe the LEZ scenario in our platform as well as the first results obtained on the socio-differentiation of the LEZ constraints (mobility for individuals) and impacts (exposure on individuals).&#160;AknowledgmentsThis work was supported by the EUR-LIVE program at Universit&#233; Paris Est Cr&#233;teil (French National Research Agency fundings).&#160;ReferencesElessa Etuman, A., & Coll, I. (2018).&#160;OLYMPUS v1.0: Development of an integrated air pollutant and GHG urban emissions model-methodology and calibration over greater Paris. Geoscientific Model Development, 11(12), 5085&#8211;5111.&#160;https://doi.org/10.5194/gmd-11-5085-2018Elessa Etuman A., Coll I., Makni I., Benoussaid T., Addressing the issue of exposure to primary pollution in urban areas: Application to Greater Paris, Atmospheric Environment, Volume 239, 117661, ISSN 1352-2310,&#160;https://doi.org/10.1016/j.atmosenv.2020.117661, 2020Host, Sabine, C&#233;cile Honor&#233;, Fabrice Joly, Adrien Saunal, Alain Le Tertre, et Sylvia Medina. &#171;&#160;Implementation of Various Hypothetical Low Emission Zone Scenarios in Greater Paris: Assessment of Fine-Scale Reduction in Exposure and Expected Health Benefits&#160;&#187;. Environmental Research 185 (juin 2020): 109405. https://doi.org/10.1016/j.envres.2020.109405.