The Linear No-Threshold Model of Low-Dose Radiogenic Cancer: A Failed Fiction

Abstract

The linear no-threshold (LNT) model for low-dose, radiogenic cancer has been a fixture of radiation protection and regulatory requirements for decades, but its validity has long been contested. This article finds, yet again, more questionable data and analyses purporting to support the model, this within the "gold-standard" data set for estimating radiation effects in humans. Herein is addressed a number of significant uncertainties in the Radiation Effects Research Foundation's Life Span Study (LSS) cohort of atomic bomb survivors, especially in its latest update of 2017, showing that the study's support of the LNT model is not evidence based. We find that its latest 2 analyses of solid cancer incidence ignore biology and do not support the LNT model. Additionally, we identify data inconsistencies and missing causalities in the LSS data and analyses that place reliance on uncertain, imputed data and apparently flawed modeling, further invalidating the LNT model. These observations lead to a most credible conclusion, one supporting a threshold model for the dose-response relationship between low-dose radiation exposure and radiogenic cancer in humans. Based upon these findings and those cited from others, it becomes apparent that the LNT model cannot be scientifically valid.

Keywords: Hiroshima and Nagasaki atomic bomb survivors; Life Span Study (LSS); Radiation Effects Research Foundation (RERF); linear no-threshold (LNT); low-dose radiation (LDR); radiation protection; radiation regulatory requirements; radiogenic cancer; threshold.

Figure 1.

LSS solid cancer incidence, excess relative risk (ERR) by radiation dose, 1958 to 1998, using DS86 dosimetry system. Note that doses <0.1 Gy appear to have ERRs <0. LSS indicates Life Span Study.

Figure 2.

LSS solid cancer incidence in the 0 to 0.4 Gy dose range derived from that reported by Furukawa. LSS indicates Life Span Study.

Figure 3.

LSS data derived from Grant’s reported data in Appendix Table E1. ERR values are shown with 95% confidence intervals, indicating large uncertainties. LSS indicates Life Span Study; ERR, excess relative risk.