Air pollution is one of the consequences of the industrial development, which causes a lot of health and environmental problems. For these reasons, the quality of the air is one of the major concerns of regional, national and European governments. All of them are developing strict normative to reduce the emissions of contaminants. The quality of the air can be analysed by means of numerical simulations. In this paper, a methodology based on Computational Fluid Dynamics (CFD) is described. This technique allows evaluating the dispersion of industrial-type air pollutants in a relatively large area, taking into account the orography, buildings and so on. Also, specific models are studied in order to consider the specific characteristics of the industrial contaminants and particles.