Cadmium levels in hair and other tissues during continuous cadmium intake

Rats that received cadmium 300 ppm in drinking water (average daily cadmium intake = 4.5 mg/rat) for 12 wk attained peak cadmium levels of 112, 34, and 19 mug/g in hair, liver, and kidney, respectively, at week 4. Rats that ingested cadmium 200 ppm (average daily cadmium intake = 3.6 mg/rat) for 13 wk attained peak cadmium levels of 29 mug/g in kidney at week 7, and 94 and 27 mug/g in hair and liver, respectively, at week 9. Despite continuous exposure to the heavy metal, tissue cadmium concentrations declined to steady-state levels of 24-33 mug/g in hair and 10-17 mug/g in liver and kidney. Histopathologic effects were not observed in liver or kidney. In contrast to cadmium in hair, blood cadmium levels, which remained consistently low (less than 0.04 mug/ml) throughout the study, did not correlate with changes in cadmium levels in liver and kidney.