In the cross-sectional part of the Sapaldia study, 9651 participants answered a health questionnaire and were submitted to medical tests. In order to look for possible environmental influences from the environment, urban, rural and alpine regions were selected. As expected, the highest concentrations of NO2, SO2 and particles were measured in cities. The study showed that the prevalence of respiratory symptoms or diseases was higher in the more polluted areas. Forced vital capacity was lower in regions with higher mean annual values of pollutants, as compared with regions with the lowest mean values. Allergology tests showed that about one third of the population was atopic. Passive exposure to tobacco smoke, especially at the workplace, was associated with increased risk and prevalence of respiratory symptoms and diseases, such as asthma, bronchitis and chronic bronchitis. In conclusion, long-term exposure to environmental pollutants, even at low concentrations, significantly decreases the lung-function and increases the risk for respiratory symptoms or diseases.