Lung functions and chest radiographs in shipyard workers exposed to asbestos

Lung functions and diffusing capacity for carbon monoxide were examined in 299 shipyard workers occupationally exposed to asbestos, among whom there was an equal number of smokers and non-smokers. The workers were classified into groups according to the lung fibrosis profusion and the length and width of the pleural plaques in accordance with the 1980 ILO International Classifications of Pneumoconioses. With regard to the profusion of the parenchyma, workers classified in category 2 (subcategories 2/1 and 2/2) had significantly lower FVC and FEV1 values than the workers in categories 0 (P < 0.01) and 1 (P < 0.05). With an increase in the category of profusion there was a trend towards a fall in mean MEF25, MEF50 and MEF75 values, but it was not significant. Diffusing capacity for carbon monoxide was identical for all categories. There were no significant differences between the workers without pleural plaques and those with visible plaques in respect to lung function values. With an increase in the length and width of the plaques FVC, FEV1, MEF25 and MEF75 values tended to become lower. The results demonstrate that the changes detected on the radiographs of the lungs and pleura are the early indicators of possible asbestos disease in shipyard workers.