The current state of workers' pneumoconiosis in relationship to dusty working environments in Okayama Prefecture, Japan.

This study involved the examination of 1,006 chest x-ray films of workers from the industries devoted to shipyard welding, stone grinding, and refractory crushing in southern Okayama prefecture. Of the reviewed films, analysis was focused on subjects with a profusion rate of 0/1 as well as pneumoconiotic subjects (exhibiting profusion rates of 1/0 or greater) in order to discover cases in the beginning stages. One-hundred-and-seventy-four films illustrated a profusion rate of 0/1 or greater, and the proportion of this profusion rate was revealed to be highest in shipyard welders.