Hair cadmium content: is it a biological indicator of the body burden of cadmium for the occupationally exposed worker?

The primary objective of this study was to evaluate the cadmium (Cd) levels measured in scalp hair as a potential predictive index of the body burden of Cd. In vivo measurements of kidney and liver Cd along with hair, blood, and urine Cd levels were obtained in 29 industrially-exposed workers and ten control subjects. The relationship of hair Cd levels to the Cd values for the kidney, liver, blood, and urine were tested using nonparametric analyses. In the control group no statistically significant correlations were found. In the Cd-exposed workers with more than one year of employment there were weak correlations (p approximately equal to 0.05); however, the relationships were not sufficiently quantitative for predicting the status of an individual worker. Furthermore, when workers with less than one year of exposure were included in the analysis, no significant correlations were obtained. Although this latter group of workers had low body burdens of Cd, exceptionally high Cd concentrations were found in their hair--an observation that was unexpected. It was concluded that hair Cd levels are not a good index of body burden of Cd in the industrially-exposed individual.