Cadmium in blood and urine after cessation of exposure

A plant for the synthesis and packaging of cadmium oxide was operated for 32 months (1982-84) in a small chemical factory producing zinc and copper oxide. The cumulative exposure of 6 workers was from 12 to 190 days. Five years after cessation of exposure the blood cadmium levels in the exposed were, on average, 4-10 times higher than those of a reference group and the urinary cadmium levels were 1-6-times higher. In view of the long half-life of cadmium in the human body, the choice of normal reference values requires particular care since brief and sometimes forgotten exposures to cadmium may be a confounding factor to set reference values.