Prevalence of respiratory symptoms in towns with different air pollution.

An epidemiologic study was carried out for the estimation of air pollution as a risk factor for chronic obstructive lung disease. The whole male population aged 40 to 60 years was investigated in a polluted and a non-polluted control town. The subjects with occupational exposure to dusts, gases and irritant vapours were discarded from the study. The prevalence of respiratory symptoms and of chronic bronchitis in the polluted town was twice that in the control (non-polluted) one. These results are discussed in the light of some previous investigations of the authors and of the available data in the literature.