Hard-metal lung disease. A report of 4 cases.

The properties, manufacture and uses of hard metal are briefly described, and its harmful effects on the respiratory tract are enumerated, discussed and illustrated in 4 subjects who had been drill sharpeners on goldmines. It cannot be unequivocally claimed that these are cases of interstitial fibrosis due to the inhalation of hard-metal dust, as both radiography and histology in this disease are nonspecific. There appears however to be good reason to encourage further research on drill sharpeners on goldmines and tool-room workers in general.