Stram D O, Sposto R, Preston D, Abrahamson S, Honda T, Awa A A
Radiation Effects Research Foundation, Hiroshima, Japan.
Radiat Res. 1993 Oct;136(1):29-36.
Analysis of data on stable chromosome aberrations collected between 1968 and 1985 by the Radiation Effects Research Foundation (RERF) on 1703 individuals exposed to A-bomb radiation in Hiroshima and Nagasaki, Japan, reveals different dose-response relationships in the two cities, as well as significant effects of both time of assay and age at exposure. In Hiroshima, the proportion of cells with aberrations increased by 0.080 per sievert at low doses, assuming a constant neutron radiation RBE of 10 relative to gamma radiation, for assays performed during the latest period (1981-1985). In Nagasaki, the low-dose increase was 0.0126 per sievert. There was evidence that radiation exposure was more effective for producing stable aberrations at some younger ages at exposure, although the interpretation of this interaction is difficult. Modeling neutron and gamma-ray components of dose separately in a way which allows the neutron RBE to vary with dose yielded an estimated low-dose limiting value of RBE of 707 (95% confidence bound 200-infinity), with a low-dose response of approximately 0.008 aberrations per sievert. This RBE is much higher than the published RBEs for induction of aberrations in vitro. The high estimated RBE and the differences in dose response by city both are suggestive of systematic dose estimation errors in which either neutrons were underestimated in Hiroshima or gamma rays were overestimated in Nagasaki.
辐射效应研究基金会（RERF）在1968年至1985年间收集了日本广岛和长崎1703名受原子弹辐射个体的稳定染色体畸变数据，分析结果显示这两个城市存在不同的剂量反应关系，以及检测时间和受照年龄的显著影响。在广岛，对于最近时期（1981 - 1985年）进行的检测，假设相对于γ辐射，中子辐射的相对生物效应（RBE）恒定为10，低剂量时畸变细胞的比例每西弗增加0.080。在长崎，低剂量增加为每西弗0.0126。有证据表明，在某些较年轻的受照年龄，辐射暴露对产生稳定畸变更有效，尽管这种相互作用的解释很困难。以允许中子RBE随剂量变化的方式分别对剂量的中子和γ射线成分进行建模，得出RBE的低剂量极限值估计为707（95%置信区间200 - 无穷大），低剂量反应约为每西弗0.008个畸变。这个RBE远高于已发表的体外诱导畸变的RBE。高估计RBE和城市间剂量反应的差异都表明存在系统剂量估计误差，即广岛的中子剂量被低估或长崎的γ射线剂量被高估。
