抄録
Polonium-210 (210Po) excreted in urine of the workers in the Ningyo-toge uranium mine was measured in order to evaluate the internal exposure due to radon-222 (222Rn) and its daughters.
210Po excreted in urine of the miners (shovellers and timberers), 1.35pCi/day, was higher than that of the other workers in the mine, 0.56-0.61pCi/day, and of control persons living in Okayama City, 0.65pCi/day, with high significance. There was no significant difference between 210Po excreted in urine of shovellers and of timberers.
In miners, no correlation between 210Po in urine and integrated working time, nor the correlation between 210Po in urine and the estimation of integrated dose of the internal exposure due to 222Rn and its daughters could be observed.
Though these results mean the difficulty for the estimation of internal exposure by the urinary value of 210Po, they also suggest the possibility for an effective method for environmental assessment in radiological health and safety.
Radium-226 excreted in urine of the miners was not higher than that of control persons.
