Abstract
Data from 37 asbestos workers with diffuse pleural fibrosis have been analysed. None had radiological evidence of asbestosis or physiological evidence of airflow obstruction. Forty per cent had breathlessness of MRC grade 3 or higher. Vital capacity was significantly lower in the subjects in the higher grades of breathlessness and in those with greater radiographic pleural abnormality. No relationship was demonstrated between dust exposure and either radiographic abnormality or grade of breathlessness. Diffuse pleural thickening, particularly when extensive and bilateral, causes functional impairment and disability.