Studies of cadmium uptake in bone and its environmental distribution

Rat experiments indicate that oral ingestion of cadmium through drinking water leads to an accumulation of cadmium in bone, in addition to liver and kidney. After five weeks of cadmium intake in drinking water (50 to 100 mg/L), the bone cadmium levels increased in proportion to the intake concentration. Bone and kidney histology showed no signs of bone or kidney damage up to 5 wk of cadmium ingestion. Cadmium accumulation in bone was a primary phenomenon and not secondary to renal failure. In addition, cadmium levels have been estimated in a variety of sources, e.g., foodstuff, fertilizer, and sewage sludge, using neutron and proton activation analyses and atomic absorption spectrophotometry. Cadmium levels of Canadian foods are in the range of 0.002-0.07 mg/kg, and soils are in the range of 0.55 to 1.72 mg/kg. Fertilizers contain cadmium from 0.3 to 1.25 mg/kg, whereas sewage sludge contains up to 122 mg/kg.