Prevalence of asbestos related lung disease among employees in non-asbestos industries.

Employees from two non-asbestos industries wee examined to assess the prevalence of asbestos-related lung disease. Of the 214 employees, one suffered from a malignant mesothelioma of the pleura and in 13 (6.1%), pleural plaques were diagnosed radiologically. the plaques were symptomless and not associated with any disturbance in respiratory function. The sole source of asbestos fibre in one factory was the asbestos insulation surrounding steam and hot water pipes similar to that found throughout industry. Exposure occurred as the result of the way in which this insulation has been handled routinely in industry by people who have commonly been unaware either of their exposure or of its significance. In the second factory there was the possibility of additional exposure originating from a neighbouring industry that was a major consumer of asbestos. The results suggest that maintenance workers may be particularly at risk and that the presence of pleural plaques may be under-reported in the absence of a history of asbestos exposure to direct attention towards them. The presence of pleural plaques has important consequences for the individual and for others who have shared the work environment.