To investigate the interaction of smoking and history of long-term occupational exposure to organic solvents on the prevalence of chronic bronchitis (CB) among middle aged and elderly men.
A questionnaire on health, lifestyle, and working conditions, and a clinical examination including measurements of height, weight, and peak-flow. Self-reported occupational solvent exposure for 5 years or more was compared to never exposed. Three thousand two hundred eight men aged 63 ± 10 years were included.
Four hundred sixty one men had CB (14.4%). Current smoking and the interaction of smoking and long-term occupational exposure to organic solvents (>5 years) were the factors most strongly associated with prevalence of CB. In the solvent exposed group odds ratio for CB was 7.0 (95% confidence interval [CI]: 3.4 to 14.5) comparing current smokers with non-smokers against only 3.7 (95% CI: 2.8 to 4.8) in the nonexposed group, also after control for potential confounders. Among nonsmokers only, long-term exposure to organic solvents was not associated with an increased prevalence of CB.
Current or previous occupational exposure to organic solvents doubles the smoking related risk of CB, probably due to an additional irritative effect in the alveolar and bronchial mucosa.
From the Department of Occupational and Environmental Medicine (Dr Ebbehøj, Mr Hein, Mr Suadicani, Mr Gyntelberg), The Copenhagen Male Study, Epidemiological Research Unit, H:S Bispebjerg University Hospital, Copenhagen; and Research Centre for Prevention and Health (Mr Hein), Glostrup University Hospital, Glostrup, Denmark.
Niels Erik Ebbehøj, Hans Ole Hein, Poul Suadicani, and Finn Gyntelberg have no commercial interests related to this article.
Address correspondence to: Dr N Ebbehøj, DMSc, Department of Occupational Medicine, Bispebjerg Hospital, DK 2400 Copenhagen NV, Denmark; E-mail: firstname.lastname@example.org.