Our study aims at statistical modelling of changes in the level of air pollution in the area of Szczawno Zdrój in Poland throughout the period of 1989-2003, which was marked by a decrease in coal production as well as by rapid increases in traffic intensity. Sulphur dioxide and the nitrogen dioxide were chosen as pollution indicators. Changes of the averaged concentrations across years are modelled by 5 regression models: linear, logarithmic, 2^nd degree polynomial, 3^rd degree polynomial and 4^th degree polynomial. Changes in average yearly concentrations of pollutants during the 1980s and 1990s indicate considerable improvement of air quality regarding sulphur dioxide and nitrogen dioxide contents. A noticeable tendency toward a decrease in air pollution results from limiting of sulphur dioxide emission sources, which translates into liquidation of especially burdensome industrial plants, installation of devices for sulphur removal from fumes, and substantial reduction of air pollution coming from the Czech Republic and Germany.