Results of pneumoconiosis examination--different trends among industries

In this report we describe yearly changes in pneumoconiosis patients and pneumoconiosis progression in each industry in Japan, using statistics of Ministry of Labour based on the results of pneumoconiosis examinations performed at plants in accordance with the Pneumoconiosis Law. We found that the number of workers exposed to mineral dust decreased yearly. The number of subjects with positive findings, the number of new cases with pneumoconiosis, the ratio of positive findings, and the incidence rate of pneumoconiosis also decreased. In particular, the number of subjects with positive signs of pneumoconiosis clearly decreased. A similar tendency was seen in the number of cases including voluntary applications. Industry-wise, however, there was a large difference among the industries. The ratio of pneumoconiosis with complications, along with the progression ratio, decreased. Subjects with progressed pneumoconiosis decreased annually, exhibiting less-serious signs and symptoms. There have been reports with a different view about the general trend of pneumoconiosis. We examine and discuss the cause of discordance between the studies.