2000 年 17 巻 1 号 p. 7-13
Chrmosome aberrations in the lymphocytes of radiological technologists (RT) in Kumamoto Prefecture were analyzed by the trypsin G-banding method to estimate the exposure dose to radiation. Structural aberrations were identified in 384 (2.5%) of 15,442 cells analyzed from 53 RT as compared to 177 (1.6%) of 11,136 cells from 36 healthy controls. Stable aberrations were the most frequent in both groups and were either translocations or deletions. Unstable aberrations were mainly acentric fragments in both groups. The frequency of translocations and acentric fragments was significantly higher in the RT than in the controls and was highest in the RT over 50 years old. The highest frequency observed in the >50 age group was attributed to the unknown for cumulative dose prior to introduction of film badges. Dose estimation for each RT was done by using dose-response curves of stable and unstable type of chromesome aberrations. The relationship between frequency of chromesome aberrations and cumulativeradition doses of the 53 RT can be expressed by the equation y = 0.22 + 0.37D + 4.35D2, r = 0.702, where y is corrected frequency of chromosome aberrations after subtracting the increase with age and D is the cumulative radiation dose in Sv.