[Level of SO2 pollution and the prevalence of bronchitis]

The prevalence of chronic bronchitis (according to the BMRC questionnaire on respiratory symptoms) for 1182 male smokers, as well as their peak flow rate, are related to age (18-65 years), cagarette consumption (1-55 cig./day) and exposure to atmospheric SO2 pollution (20-65 microgram/m3).