What does the evidence say?
Radiation exposure over extended periods of time (several years)
LNT model Prediction - Using BEIR VII Report radiation cancer risk factors (NRC, 2006)
Conclusion: Radiation exposure over extended periods of time did not increase but reduced cancers, contradicting the LNT model.
Repeated low-dose radiation treatments to cancer patients
Conclusion: Repeated low-dose radiation treatments to cancer patients did not increase but reduced cancers, contradicting the LNT model.
Instantaneous Low-dose radiation Exposures
Most important data from atomic bomb survivors.
These data are routinely quoted to support the LNT model.
The atomic bomb survivor data have been analyzed using the LNT model shape for dose-response in order to extract the ERRs. The resulting shape of dose-response appeared to be consistent with the LNT model in 2003. With more follow-up, in update publised in 2012, the shape is not consistent with the LNT model because of the curvature in the data.
Major change in atomic bomb survivor data in 2012.
Reduction of cancers as the radiation dose increases from 0.25 Gy to 0.5 Gy (significant curvature) cannot be explained with the LNT model.
Explanation of curvature using Radiation Hormesis model.
If radiation hormesis were valid, the survivors in the lowest dose bins would have reduced cancers. However, the data from these bins were used in the fitting process to determine the baseline cancer rates, and so the baseline cancer rates would have a negative bias. Correcting for this negative bias, the dose-response curve attains the J-shape shown in the graph below consistent with radiation hormesis.
Links to references: (Doss, 2013)
The above are some examples of publications showing reduction of cancer risk from low-dose radiation exposures, contradicting the LNT model.
Compilation of evidence against the LNT model
All of the evidences above show reduction of cancers or no increase in cancers following low-dose radiation exposures, contradicting the LNT model.
Considerable number of publications have claimed evidence supporting the LNT model. These will be discussed in the next section.
Next Section: Claimed evidence for the LNT model