Low dose radiation and childhood cancer

The model of leukaemogenesis used in this paper shows that if radiation acts on all cell generations throughout fetal development then there is a quartic relationship between radiation dose and leukaemia incidence. A consequence of this is that critical groups with a high radiation dose will have a disproportionate increase in their rate of leukaemia. The precise risk in a population, however, will depend on the fraction of the spontaneous mutation rate which is caused by natural background radiation dose within the population. Neither of these is known with certainty but the model shows that reasonable assumptions result in a range of predicted risk ratios which are much higher than in previous analyses of this problem. Thus although the observed increase of acute lymphoblastic leukaemia in Seascale could be in part due to chance and in part due to other factors, such as infection, the contribution from Sellafield discharges seems greater than previously suggested. (Author)