Occupational exposures to inorganic dust are associated with emphysema: the SCAPIS cohort.

OBJECTIVES: There is a lack of knowledge about whether occupational exposures increase the risk of emphysema, especially in never-smokers. Our objective was to determine if occupational exposures are associated with emphysema and impaired diffusing capacity. METHODS: In the Swedish CArdioPulmonary bioImage Study (SCAPIS), persons from the general population aged 50-64 answered a questionnaire and underwent CT of the lung as well as assessment of the diffusing capacity of their lungs for carbon monoxide (DLCO), presented as DLCO<lower limit of normal (LLN). Emphysema was defined as emphysema in any part of the lungs. Occupational exposures were assessed by a job exposure matrix based on longest held job. ORs with 95% CIs were calculated using logistic multivariable models. RESULTS: In this cross-sectional study (27 370 persons including 13 981 never-smokers), occupational exposure to inorganic dust was associated with emphysema (OR 1.25, 95% CI 1.07 to 1.47), also among never-smokers, (OR 1.46, 95% CI 1.00 to 2.11). There were associations with DLCO<LLN for occupational exposure to inorganic dust and vapour and gases. With all exposures in the same model, inorganic dust was associated with emphysema (OR 1.30, 95% CI 1.08 to 1.57), and vapour and gases were associated with DLCO<LLN (OR 1.17, 95% CI 1.00 to 1.38). In those with emphysema and impaired DLCO, there was an association with inorganic dust (OR 1.65, 95% CI 1.20 to 2.28), also among never-smokers (OR 3.79, 95% CI 1.35 to 10.63). CONCLUSIONS: Occupational exposures to inorganic dust are associated with emphysema. The association is stronger in those with the combination of emphysema and impaired DLCO indicating serious exposure effects in the alveoli.