In Reply I thank Doss for bringing to light a position not often heard with regard to our study.1 While determining the association of radiation exposure and cancer risk was not the main objective of our study, I agree this topic is important to the overall significance of our results.
There are multiple theories relating exposure to radiation and lifetime cancer risk. The linear-no-threshold (LNT) theory is the most prominent and suggests that the risk of malignancy is directly proportional to the radiation dose the child is exposed to. It contends this association is linear and can be extrapolated to zero. Proponents of the LNT find support in data from atomic bomb survivors published earlier this century. In addition, in 2006, the National Academy of Sciences BEIR 7 noted the “linear no-threshold model [LNT] provided the most reasonable description of the relation between low-dose exposure to ionizing radiation and the incidence of solid cancers that are induced by ionizing radiation.”2 Opponents to the LNT believe that low-dose radiation is not harmful and that the data from atomic bomb survivors only point to a cancer risk when the radiation exposure reaches a certain threshold (approximately 100 mGy).