Air pollution has become a constant preoccupation for governments, scientists and civil society inrecent years. Growing awareness of the impact of pollutants on health and the environment has ledto considerable efforts to reduce air pollution.Because of the diversity of pollutants likely to be present in the atmosphere, air pollution is anextremely complex phenomenon. Pollution levels on the ground depend on the nature andconditions of pollutant discharge, as well as on atmospheric conditions that influence the transportof pollutants.These phenomena mainly occur in the troposphere, the lowest layer of the atmosphere.In the long term, these emissions also compromise the resources needed for the sustainabledevelopment of our planet.The aim of this paper is to characterize the effects of the tall buildings on the dispersion of pollutantsinto the atmosphere.The first part of this work provides numerical prediction of the turbulent air flow structure aroundthe tall building. The second part performs the behaviour of particles transport and sedimentationaround the tall building, and their dispersions intro the atmosphere.Numerical prediction is based on the k-ω SST turbulence model to predict atmospheric flow aroundthe tall building, and the Euler-Lagrange approach is used to track pollutants. The diameters of theparticles considered in this work are of 1, 5, 10, 20, 50 and 100 µm,This work contributes to understanding the effects of tall buildings on the dispersion of thepollutants into the atmosphere, and this evidence can be used to develop strategies to improve airquality in densely populated urban areas.

Keywords: Turbulence, Euler-Lagrange, particles transport, pollutants,