Small-airways dysfunction in never smoking asbestos exposed Danish plumbers

Summary Among 701 Copenhagen plumbers we examined the lung function of 23 never smokers, who had removed asbestos insulation and intermittently been exposed to high levels of asbestos for about 25 years without being exposed to welding fume. The plumbers had significantly lower TLC, MEF₂₅, MEF₅₀, closing volume and closing capacity in comparison to 23 never smoking electricians without asbestos exposure. There was no reduction in TL_CO. Pulmonary clearance of aerosolized ^99mTc-DTPA was normal indicating that the asbestos had not induced increases in pulmonary epithelial permeability. However, in 11 of the 23 plumbers the ^99m-Tc-DTPA ventilation scintigrams had a slightly irregular and spotty appearance, which together with the results of the lung function tests are suggestive of small airways' dysfunction. None of the subjects had symptoms or clinical signs of lung disease.