The industrial development of the last years and its interaction with the environment is one of the most important problems of the next future. While the pollution due to industrial production is actually strictly regulated by laws that force companies to observe precise constraints, pollution due to vehicle emissions, because of pollutants sources general diffusion, is a problem for whose solution technological and political measures conditioning collective customs and manners are needed. The adoption of these measures, especially for emergency situations, is performed on the base of data provided by special detectors capable of measuring concentrations of some substances. This methodology can cause two great problems: (i) because of required equipment high costs, it is not always possible, on the ground of fixed detectors location in a certain area, to obtain reliable information on the distribution of the pollutant substances on the whole area; (ii) mistakes strongly depending on receptor localization can arise, for instance when detectors are located in proximity of pollutant sources. In order to solve these problems, general models for the evaluation of pollutants levels which take into account the different complex factors (i.e. traffic data, meterological conditions, topological characteristics of the observed area) influencing the phenomena of the emission and of the diffusion of the pollutants are needed.