Prevalence of radiographic small lung opacities and pleural abnormalities in a representative adult population sample.

The prevalence of radiographic widespread small lung opacities and pleural abnormalities in the general population was assessed as part of the Mini-Finland Health Survey, which was based on a representative sample of people aged 30 years or over. Full-size chest radiographs of 7,095 persons (89% of the sample) were classified. Two radiologists classified all the radiographs according to the ILO 1980 Classification of Radiographs of Pneumoconioses. Small lung opacities and pleural abnormalities were considerably more prevalent in the older age groups and in men. Small lung opacities on the radiographs and pleural abnormalities were associated with work in industrial occupations, particularly in men. There was a clear association between small lung opacities and pleural abnormalities. The sex differences may be related to occupational factors, particularly dust exposure. The elevated risk of pleural plaques in persons with small lung opacities on the radiographs may indicate a fiber effect.