From the standpint of the health protection of uranium miners and millers, it is important to investigate the hazzards uot ouly by the inhalation of the dust of the uranium and its daughter nucleides but also by the external exposure of the gamma irradiation of the daughters.
In this study, the author planned to investigate experimentally the combined effects of the toxicity of uraniun and the external gamma irradiation.
For C57BL mice, uranyl nitrate (5mgU/kg or 10mgU/kg) was injected intraperitoneally, and Co-60 gamma ray (325r or 650r) was irradiated, they were devided into 8 groups as U1 (5mgU/kg administered alone), R1 (325r irradiated alone), U1R1 (5mgU/kg+325r), U2 (10mgU/kg alone), R2 (650r alone), U2R2 (10mgU/kg+650r) and the control. After the treatment, they were examined on their survival ratio, body weight and histology of kidney.
For the rabbits, they were devided into four groups. In the first group (U), 0.2mgU/kg of uranium nitrate was injected intravenously; in the second group (R), 800r of gamma ray of Co-60 was irradiated: in the third group (UR), uranium and gamma ray of the same doses as the above were abministered simultaneously; and the fourth group was the control. Blood picture, blood catalase activity, serum phosphatase, serum creatinine, serum protein, none protein nitrogen of blood, urine catalase activity and uranium excreted in urine were examined.
The resulls were as follows:
1) Concerning about suryival ratio for 30days of mice, the group U1 was 80%, Rl 100%, U2 30%, R2 20%, U1R1 60%, aud all of U2R2 died within 7days.
2) The histology of mice kidney treated by uranyl uitrate showed degeneration of tubular epithelium and retention of protein substances in the lumens of Bowman's capsule. In the groups of gamma irradiation combined with uranium treatment, it was not clear the additional effect of degeneration.
3) In rabbits, serum acid phosphatase increased in one of the group (U) and all of the group (UR). None protein nitrogen in blood increased in the group (UR).
4) Serum protein catalase activity in blood, alkaline phosphatase in serum showed no recognizable changes in any groups.