If every single cumulative nanosievert of ionising radiation dose really was responsible for adverse health effects and increased morbidity and mortality, as per the "linear non-threshold hypothesis" that anti-nuclearists love to carry around etched on their stone tablets from the mount, then we would be able to see that increased morbidity and mortality - through careful, well-controlled, quantitative scientific epidemiology - in every single medical radiologist and nuclear medicine technologist, every experimental physicist and every biomedical researcher who uses radionuclides. We would see it in nuclear energy workers who work around ionising radiation.
We would see the radiation-related morbidity and mortality from Chernobyl fulfuling the linear-non-threshold based predictions of the anti-nuclear activists, instead of the real-world epidemiological outcomes which turned out, to the surprise of many scientists, to be nowhere as bad as some predicted.
We would see it epidemiologically in every person who lives in Ramsar, or Kerala, or Denver or Cornwall, compared to populations living in other places that do not have those unusually high natural background ionising radiation doses.
And of course we would see increased radiation-related morbidity and mortality in all commercial airline pilots and crews, who have the greatest occupational ionising radiation dose of any people working in any occupation.
But we do not see any of these things, the predictions of what we would empirically see.
That's how we do science. You make the hypothesis, you determine what the consequences will be that you will be able to see empirically, and then you go and look at the empirical data.
It doesn't matter who made the hypothesis, or what her name is, or how smart they are or how highly regarded they are - if it doesn't agree with experiment then it's wrong.
The hypothesis that every single cumulative nanosievert of ionising radiation dose is responsible for adverse health effects and increased morbidity and mortality has been a hypothesis for the last 50 years, and it has remained a hypothesis without any real body of empirical evidence coming along to support it.
The entire science of radiotherapy is based on known radiobiological behavior - namely that fractionated doses do not have a linearly cumulative response and that there dose thresholds below which tissue does not experience any real morbidity in practice.
...suffer from the computer disease that anybody who works with computers now knows about. It's a very serious disease and it interferes completely with the work. The trouble with computers is you play with them. They are so wonderful. - Richard Feynman