Little Mark P, Wakeford Richard, Kendall Gerald M
Department of Epidemiology and Public Health, Imperial College, London W2 1PG, UK.
J Radiol Prot. 2009 Dec;29(4):467-82. doi: 10.1088/0952-4746/29/4/001. Epub 2009 Nov 18.
The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionising radiation, such as was experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily upon studies of the Japanese A-bomb survivors imply that low-level exposure to ionising radiation, including to ubiquitous natural background radiation, also raises the risk of childhood leukaemia. In a recent paper (Wakeford et al 2009 Leukaemia 23 770-6) we estimated the proportion of childhood leukaemia incidence in Great Britain attributable to natural background radiation to be about 20%. In this paper we employ the two sets of published leukaemia risk models used previously, but use recently published revised estimates of natural background radiation doses received by the red bone marrow of British children to update the previous results. Using the newer dosimetry we calculate that the best estimate of the proportion of cases of childhood leukaemia in Great Britain predicted to be attributable to this source of exposure is 15-20%, although the uncertainty associated with certain stages in the calculation (e.g. the nature of the transfer of risk between populations and the pertinent dose received from naturally occurring alpha-particle-emitting radionuclides) is significant. The slightly lower attributable proportions compared with those previously derived by Wakeford et al (Leukaemia 2009 23 770-6) are largely due to the lower doses (and in particular lower high LET doses) for the first year of life.
儿童白血病的病因总体上仍不明确，不过，诸如日本原子弹爆炸期间或放疗时所经历的中高水平电离辐射暴露，是已确定的病因。主要基于对日本原子弹爆炸幸存者研究的风险模型表明，低水平电离辐射暴露，包括无处不在的天然本底辐射暴露，也会增加儿童患白血病的风险。在最近一篇论文（韦克福德等人，《白血病》，2009年，第23卷，第770 - 776页）中，我们估计英国儿童白血病发病率中可归因于天然本底辐射的比例约为20%。在本文中，我们采用之前使用过的两组已发表的白血病风险模型，但使用最近发表的英国儿童红骨髓所接受的天然本底辐射剂量的修订估计值来更新之前的结果。使用更新后的剂量测定法，我们计算得出，预计英国儿童白血病病例中可归因于这种暴露源的比例的最佳估计值为15% - 20%，尽管计算中某些阶段（例如不同人群之间风险转移的性质以及从天然存在的发射α粒子的放射性核素所接受的相关剂量）存在的不确定性很大。与韦克福德等人之前得出的比例（《白血病》，2009年，第23卷，第770 - 776页）相比，可归因比例略低，这主要是由于生命第一年的剂量较低（特别是低线性能量传递剂量）。
