有害性金属の衛生化学的研究(第1報) : カドミウムの残留排泄および体内分布について その1

抄録

Hygienic Chemical Studies on Poisonous Metals : Body Retention, Excretion, and Distribution Pattern of Cadmium Progress of industrial technology has been increasing environmental pollution in recent years. Itai-Itai disease occurred in Toyama Prefecture, which is considered to be caused by taking materials containing a large amounts of cadmium. Therefore, body retention, excretion, and distribution of cadmium were examined as the first step to reveal cadmium behavior in living organisms in order to elucidate the Itai-Itai disease factor. Most of the radioactive cadmium given by oral administration was excreted rapidly, about 90% into feces and 0.4% into urine on the first day. A small amount of the metal was absorbed and most of them accumulation in the liver. The whole-body counts in living animals showed about 10% of the dose on the first day, and it decreased rather gradually and about 0.6% of the dose was still retained 24 days after the administration. The biological half-life of absorbed cadmium was calculated statistically as 15.3 days during the time from 3 rd to 24 th day after administration. On the other hand, radioactive cadmium was also given intravenously to a group, of and about 25% was excreted into feces and 1.5% into urine on the 5 th day after administration. The whole-body counts after intravenous administration showed about 65% of the dose on the 5 th day, and it decreased slowly thereafter for a long period and the biological half-life of cadmium was 333.6 days. Linear retention lines of cadmium were plotted on a semilogarithmic scale during to 71 days after administration. Accumulation of radioactive cadmium in the liver was the highest among the organs, similar to oral administration. Accumulation of radioactive cadmium in the kidney increased with time.