This paper is devoted to the study of pollutant dispersion and the effect of barrier placement in the flow field. For the study 2D models were generated and tested through the widely used Computational Fluid Dynamics (CFD) program; Fluent. The barriers consisted of trees (in various stages of vegetation), single and two-storey buildings representing domestic housing. These barriers were placed downwind of four pollutant aerosol sources and their effect on particle dispersion examined. Arsenic-Hydride particles of various size ranges were released from these four locations at a height of 20m from the ground surface. Barriers were placed at varying distances from the sources from 5m to 500m and their effect modelled and analysed. A standard wind profile equation was used to control the inlet flow with a reference speed of 5.5ms^-1 at 10m used.