Abstract

In 1968 a 10 per cent random sample of men variously exposed to asbestos at work in HM Dockyard, Portsmouth, was examined to determine the prevalence of asbestos-related lesions. Those who responded at that time have been studied after an interval of nine years to determine attack rates. Among those who had no lesion in 1968 and were reexamined, 10.6per cent had developed some asbestos-related lesion but only 0.6 per cent had pulmonary parenchymal fibrosis whereas 3. 7 per cent of those with a pleural lesion at the initial survey were found to have developed parenchymal fibrosis. Dose response relationships were found in relation to occupations (potential risk of exposure), time in that occupation and time elapsed since first employment in that occupation. The prevalence of lesions among smokers and ex-smokers was almost double that in non-smokers. All those who developed parenchymal fibrosis had a positive smoking history.