[Exposure to asbestos and asbestos-related pulmonary changes among employees at a magnesium plant]

Prevalence of disease related to previous exposure to asbestos was investigated in a cohort of 394 men who had worked for more than a year at a magnesium plant before 1970. Radiography showed lung fibrosis in nine men (2.3%) and pleural plaques in 40 men (9.5%). Prevalence rates varied considerably between sub-groups subjected to different modes of exposure. For the whole cohort there was a positive correlation between prevalence rate of radiographic changes and duration of work entailing exposure to asbestos. Subjects with pleural changes had more dyspnoea than found in an external reference material. Vital capacity and forced expiratory volume in one second was significantly reduced for the whole cohort. A significant reduction in lung function was found among a larger proportion of subjects with pleural changes than among subjects with no radiographic indications of such changes. The results unveil a need for similar surveys among workers in other energy-intensive industries where a similar mode of exposure to asbestos may be assumed.