2007 年 42 巻 3 号 p. 227-233
Application of coal combustion ashes in building materials has been limited by the presence of minor components such as radioactive substances. 226Ra, 232Th, and 40K accumulated in the ash during the burning of the coal may result in significant, several doses of mSv annually. Radon exhalation is usually low, but in some cases a significant dose (5-15mSv/y) may be calculated upon due to the 222Rn emanating from this kind of building materials. Therefore a radiological survey, classification of these materials is necessary before utilization.