Fundamental Studies on the Movement of Cadmium in Animals and Human Beings

要旨

The development of industry in Japan has been increasing environmental pollution. Itai-itai disease is concidered to be caused by intake of foodstuffs or water containing a high concentration of cadmium. Therefore, the studies on the absorption, excretion and accumulation of cadmium were carried out.Results were as follows:1) Absorption rate of orally administered cadmium in mice was 2% and was not influenced by the factors of pregnancy, hunger and thirst.2) Five mg of cadmium in drinking water was administered to a 58-year old man divided into 3 doses in 1st day. Absorption rate in this experiment was estimated to be 5.33%. When the same experiment on cadmium in rice was carried out, its value was 1.53%.3) Biological half time in the whole body of mice was concluded to be about 60 days. In man, this value was estimated to be 3 to 8 years.4) Food containing 10ppm cadmium was given to the mice for a long period. Accumulation rate in this experiment decreased gradually and was not influenced by sex difference, times of pregnancy and nursing.5) Total body contents of cadmium in the human body were estimated to be 32mg in males, and 52mg in females.6) On the sex difference in man, it became apparent that cadmium concentration in female was twice as much as that in male, in both cases of hepatic and renal diseases, a high tendency was observed in the value of the ratio in human liver and kidney.

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