Cobalt concentration in urine as an indicator of occupational exposure to low level cobalt oxide.

The aim of this study was to verify the relationship between the cobalt oxide concentration in air and the cobalt concentration in urine. In the first study, we measured the cobalt concentration in the urine of 16 workers exposed to cobalt oxide in a Digital Video Cassette manufacturing plant at the beginning and end of their workshift during 2 working cycles. In the second study, we measured the exposure level to cobalt oxide and the cobalt concentration in urine at the end of the workshift of other 16 workers on 3 out of 5 consecutive work days (Monday, Wednesday and Friday).