The analysis carried out earlier in Cracow showed that the high level of SO2 and particulate matter (PM) alone cannot be responsible for an excess of chronic chest symptoms and faster lung function deterioration in the population at large. To check the hypothesis that acid aerosols present in the urban air may cause substantial damage of the lungs, data from a 13-year follow-up survey of chronic chest diseases in Cracow (1968-1981) have been reanalyzed. In the plan of the analysis, three areas of the city with various levels of sulfate and sulfur transformation ratio (STR) in the urban air have been defined. In each of the defined areas, the prevalence of chronic chest symptoms, as well as lung function decline, have been studied. In total, the lung function study group consisted of 1414 persons (584 males and 830 females). Those men who lived in the area with the higher sulfate and STR had lower FEV1 levels by about 151 mL than did the residents of the other areas, and this was equivalent to the effect of smoking. In females, the pattern was generally the same. In men, the FEV1 decline rate (mL/year) over the 13-year period was significantly faster by about 11 mL/year in the areas with higher and intermediate STR, which was again equivalent to the effect of smoking. It was found that the level of SO2 and PM in the urban air correlated with the symptom prevalence in women; however, it had no clear impact on lung function deterioration.