To actually disprove the theory you need an experiment that can detect changes in cancer rate on the order of 40k per billion or 0.004% which have simply not been preformed.

Saying ‘we can’t measure it therefore it does not exist’ might be acceptable if it where the oldest theory. Except it’s not, people want to overthrow the existing idea with zero direct supporting evidence which is simply unscientific. If you want to supplant a theory then it’s on you to provide evidence that the existing theory is wrong, otherwise I can say low exposure levels are more dangerous because high levels result in multiple indecent cancers at the same time in some people. Therefore the risks increase at lower levels do to probability theory and we already agreed no evidence was needed.

PS: I am not saying my example is correct, just the argument your making is faulty.

If the LNT model was correct then you wouldn't need such a high level of precision, only a sample group with more radiation exposure (i.e. a medium level rather than low or high), so that the LNT model would predict that enough people would get cancer that it could actually be measured. If the people in those areas don't have an incidence of cancer which is linear with respect to the very high doses currently being used as the baseline then the LNT model is falsified.

> Saying ‘we can’t measure it therefore it does not exist’ might be acceptable if it where the oldest theory. Except it’s not, people want to overthrow the existing idea with zero direct supporting evidence which is simply unscientific.

By this logic we should be operating under the assumption that the Greek Gods actually exist because the theory is very old and it is difficult to measure.

The problem with this assumption is you can’t keep everything else identical. Population X and Y don’t grow up live and die in exactly identical areas expect for different radiation levels.

What you can do is control for as many factors as possible or use a proxy. It turns out skin cancer is a solid proxy, * and populations like Australia and skin cancer support the linear model down to the limits of our ability to detect it. But, then people want to suggest the non linear model kicks in as soon as the signal falls below the noise floor without evidence, even though that’s the same behavior in both models.

* As in you can detect population differences and work out whole body radiation dose equivalents.

PS: By this logic we should be operating under the assumption that the Greek Gods actually exist because the theory is very old and it is difficult to measure. People are promoting a new idea, not just trying to disprove an old one. Aka, Greek gods and the flying spaghetti monster have equal support. That’s absolutely fine, it’s saying some other untested theory is supported without evidence that’s at issue.

For most other things you would do a placebo controlled trial, but it might be hard to get people to sign up for a trial where you're giving them enough radiation to expect to cause a significant number of them to get cancer.

So controlling for confounders is really the only thing left if you want an answer.

And it works pretty well -- at least better than nothing -- if you actually want the answer. The problem with it is that it unfortunately can also produce whatever answer you want from a political perspective by reverse engineering which confounders to control for based on which ones shift toward the desired outcome, so you can't trust somebody else to do it for you without checking their work at a level of detail that basically amounts to redoing the analysis yourself.

> It turns out skin cancer is a solid proxy

Wait, what are you using it as a proxy for?

It’s not great, but skin cancer is more closely tied to radiation exposure rather than everything that can cause lung cancer etc.

Plus, you still have the same problem with confounders. Expect more skin cancer in a population that spends more time outside, but also potentially a very different lifestyle in that case.

And problems with radiation type as well, since many types of radiation don't penetrate the skin, so they could cause skin cancer but not other cancers. Which has implications for the fatality rate because skin cancer has a much higher survival rate than most other types.