Wakeford Richard, Little Mark P
BNFL, Risley, Warrington, Cheshire, UK.
J Radiol Prot. 2002 Sep;22(3A):A123-7. doi: 10.1088/0952-4746/22/3a/322.
Case-control studies of childhood cancer and foetal exposure to diagnostic x-rays suggest that doses as small as 10 mSv increase the risk of cancer to a detectable extent. A comparison of the risk coefficient derived from the largest such study with that obtained from the Japanese atomic bomb survivors irradiated in utero (average dose, approximately 300 mGy) shows that, once all sources of uncertainty are taken into account, these risk estimates are not incompatible. The absence of a discernible variation in the risk per unit dose over this dose range is consistent with a linear dose-response. However, uncertainties are such that definitive conclusions on the shape of the dose-response at low doses cannot be drawn from this epidemiological evidence alone. Nonetheless, the evidence does suggest that the risk is not zero at doses of the order of 10 mSv.
关于儿童癌症与胎儿期接受诊断性X射线照射的病例对照研究表明，低至10毫希沃特的剂量就能在可检测程度上增加患癌风险。将此类规模最大的研究得出的风险系数与子宫内受辐射的日本原子弹幸存者（平均剂量约为300毫戈瑞）的风险系数相比较，结果显示，一旦考虑到所有不确定性来源，这些风险估计并非相互矛盾。在此剂量范围内，单位剂量风险不存在明显变化，这与线性剂量反应关系相符。然而，不确定性因素众多，仅靠这一流行病学证据无法就低剂量下剂量反应的形状得出明确结论。尽管如此，证据确实表明，在10毫希沃特左右的剂量下，风险并非为零。
