Observations on the lungs of vanadium workers.

Out of a total of 79 employees at a factory making vanadium pentoxide from magnetite ore 63 were investigated by respiratory questionnaire, chest radiography, and tests of ventilatory function. The findings were compared with a reference group of 63 men, matched for age (to within two years) and for smoking habit (to within five cigarettes daily) selected from workers at a magnetite ore mine. Analysis of the ventilation tests showed no significant differences between the reference group and the men exposed to low concentrations of vanadium (0.01--0.04 mg/m3), despite previous exposure for an average of 11 years to concentrations in the range of 0.1 to 3.9 mg/m3. Complaint of wheezing was significantly more common among the workers exposed to vanadium than among their referents, but there were no other subjective differences between the groups. Localized fibrotic foci were reported in the radiographs of four reference cases and two men exposed to vanadium, but there were no cases of pneumoconiosis in either group.