Johnson J R, Myers D K, Jackson J S, Dunford D W, Gragtmans N J, Wyatt H M, Jones A R, Percy D H
Health Sciences Division, Chalk River Laboratories, Ontario, Canada.
Radiat Res. 1995 Oct;144(1):82-9.
To help resolve uncertainties as to the most appropriate weighting factor for tritium beta rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium beta rays compared to X rays ranged from 1.0 +/- 0.5 to 1.3 +/- 0.3. A best estimate of the RBE for this experiment was about 1.2 +/- 0.3. A wR value of 1 would thus appear to be more appropriate than a wR of 2 for tritium beta rays.
为了帮助解决关于氚β射线最合适加权因子的不确定性问题，进行了一项大型实验，以测量与X射线相比，氚水诱发CBA/H品系雄性小鼠髓系白血病的相对生物效应（RBE）。该研究旨在估计七组每组约750只小鼠髓系白血病的终生发病率；氚水和X射线的辐射剂量均约为0、1、2和3 Gy。这些小鼠白血病的终生发病率从对照组的0.13%增加到接受较高辐射剂量组的6 - 8%。使用原始数据和针对累积风险小鼠天数校正的数据，将结果拟合到各种将白血病发病率与辐射剂量相关联的方程中。与X射线相比，计算出的氚β射线的RBE值范围为1.0±0.5至1.3±0.3。该实验的RBE最佳估计值约为1.2±0.3。因此，对于氚β射线，wR值为1似乎比wR值为2更合适。
