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.