Biological dust exposure in the workplace is a risk factor for chronic obstructive pulmonary disease

Background: Chronic obstructive pulmonary disease ( COPD) is a major cause of morbidity and mortality. Although the main risk factor is smoking, 15 - 19% of COPD even in smokers has been attributed to occupational exposures. The aim of this study was to investigate the association between occupational exposure and risk of COPD. Methods: Participants were part of a cross sectional study of risk factors for COPD. A total of 1232 completed a detailed respiratory questionnaire, spirometric testsing and measurement of gas transfer. Job histories were coded according to the International Standard Classification of Occupations. These codes were then used to establish occupational exposures using the ALOHA job exposure matrix. Results: The prevalence of emphysema was 2.4%, chronic obstructive bronchitis 1.8%, and COPD 3.4%. Subjects ever exposed to biological dusts had an increased risk of chronic obstructive bronchitis ( OR 3.19; 95% CI 1.27 to 7.97), emphysema ( OR 3.18; 95% CI 1.41 to 7.13), and COPD ( OR 2.70, 95% CI 1.39 to 5.23). These risks were higher in women than in men. For biological dust, the risk of emphysema and COPD was also significantly increased in both the duration of exposure categories, again in women but not in men. No significant increased risks for COPD were found for mineral dust ( OR 1.13; 95% CI 0.57 to 2.27) or gases/fumes ( OR 1.63; 95% CI 0.83 to 3.22). Conclusion: In this general population sample of adults, occupational exposures to biological dusts were associated with an increased risk of COPD which was higher in women. Preventive strategies should be aimed at reducing exposure to these agents in the workplace.