The ventilatory function of 48 workers occupied on the average for six years in a plant producing diamond-cobalt circular saws was compared with that of 23 control subjects. The geometric mean airborne cobalt concentrations in the two main work areas amounted to 15.2 and 135.5 micrograms/m3 respectively. The spirometric changes found in the exposed workers were compatible with a moderate restrictive syndrome and were correlated with duration of exposure.
Gennart, J., & Lauwerys, R. (1990). Ventilatory function of workers exposed to cobalt and diamond containing dust. International Archives of Occupational and Environmental Health, 62(4), 333-336. https://doi.org/10.1007/BF00640843 (Original work published 1990)