Exposure to Outdoor Air Pollution and Chronic Bronchitis in Adults: A Case-Control Study

Background: Although Lebanon is a highly polluted country, so far no study has specifically been designed to assess the association between outdoor air pollution and chronic bronchitis in this country. Objective: To assess the association between exposure to outdoor air pollution and chronic bronchitis in Lebanon. Methods: A pilot case-control study was conducted in two tertiary care hospitals. Cases consisted of patients diagnosed with chronic bronchitis by a pulmonologist and those epidemiologically confirmed. Controls included individuals free of any respiratory signs or symptoms. After obtaining informed consent, a standardized questionnaire was administered. Results: Bivariate, stratified (over smoking status and gender) and multivariate analyses revealed that passive smoking at home (ORa: 2.56, 95% CI: 1.73–3.80) and at work (ORa: 1.89, 95% CI: 1.13–3.17); older age (ORa: 1.75, 95% CI: 1.55–2.39); lower education (ORa: 1.44, 95% CI: 1.21–1.72); living close to a busy road (ORa: 1.95, 95% CI: 1.31– 2.89) and to a local power plant (ORa: 1.62, 95% CI: 1.07–2.45); and heating home by hot air conditioning (ORa: 1.85, 95% CI: 1.00–3.43) were moderately associated with chronic bronchitis; an inverse association was found with heating home electrically (ORa: 0.58, 95% CI: 0.39–0.85). A positive dose-effect relationship was observed in those living close to a busy road and to a local diesel exhaust source. Conclusion: Chronic bronchitis is associated with outdoor air pollution.