[pfdietz]

No, it doesn't resolve the matter, since the lower bound on detectability is still a very large number of cancers (most of which will not have occurred yet).

Understand that regulation is not like criminal law. Radiation does not have to be presumed innocent until proven guilty.

[NovemberWhiskey]

That's such a strange thing to say; no-one is suggesting that radiation gets a presumption of innocence. As far as I understand it, there's no generally agreed viewpoint on the expected effect size for exposure to low levels of radiation. In this case, there was discovered to be no statistically meaningful effect. This is now something that new that we know.

[pfdietz]

The question becomes: how should low doses of radiation be regulated?

One approach would be unless you can prove the radiation is having an effect, it gets a free pass. This would likely result in substantially larger population exposures. If enough individual sources are given free passes, eventually the dose accumulates to something that would have an obviously visible effect.

Another approach would be precautionary: assume radiation has the maximum effect not ruled out by evidence. This would result in much stricter control than current regulation, which assumes the effect is linear down to zero dose. Some anti-nuclear activists have objected to LNT because they think it's underestimating the effect of radiation (not that they have good evidence for that.)

Current regulation is between these, assuming linear effect. This is a biologically reasonable assumption, since at low doses the number of affected cells is proportional to dose, and it's unlikely any single cell is directly affected more than once. It also takes into account the cumulative, additive effect of radiation exposures from multiple sources.