A recent document of the American Thoracic Society and two previous reports of the International Union Against Tuberculosis and Lung Disease have summarized the negative health effects due to air pollution in a list ranging from the increase of mortality to the perception of bad odors. A significant attempt to estimate, on an annual basis, the negative effects of air pollution from particulate matter less than 10 microns in aerodynamic diameter (PM10) has been carried out on data from Austria, France, and Switzerland: e.g. in France, air pollution from PM10 is responsible annually for 31,700 deaths, 36,700 new cases of chronic bronchitis and 577,000 attacks of asthma in adults, 450,000 cases of acute bronchitis and 243,000 attacks of asthma in children. Recently, a study on the long-term effects of air pollution on about 500,000 residents in metropolitan US areas evidenced that each 10 micrograms/m3 elevation in fine particulate air pollution is associated with approximately a 4%, 6% and 8% increased risk of all-cause, cardiopulmonary and lung cancer mortality, respectively. Some Italian experiences have also confirmed respiratory health damages from air pollution, namely the prospective epidemiologic studies on general population samples of the Po Delta and Pisa areas; the cross-sectional study on schoolchildren of the 'Italian study on respiratory disorders in childhood and environment' (SIDRIA); and a meta-analysis of the Italian studies on short-term effects of air pollution. In conclusion, epidemiologic studies suggest that air pollution plays an important role in the exacerbation and in the pathogenesis of chronic respiratory diseases. Thus, respiratory physicians, as well as public health professionals, should advocate for a cleaner environment.