Abstract Ground level concentrations of sulphur dioxide in the Venetian area of Italy were analyzed from a receptor-oriented point of view with reference to the seasonal evolution of the atmospheric stability over a coastal site. The observed frequency distributions of air quality data were well reproduced by employing the generalized gamma distribution. By restricting the shape-parameter in the adopted distribution function to integer values the main features of the considered region could be modelled in a simple and unified way. If the shape-parameter was allowed to assume both integer and half-integer values a more refined representation was achieved, in which the heterogeneous behaviour of the region was characterized mathematically. Economically sensitive problems such as land use planning may be possible applications of these results.