There are a huge range of models, it’s not clear which ones are correct. Nuclear proponents tend to push threshold models suggesting there are safe doses.
On the other hand: “Approximately 38.4% of men and women will be diagnosed with cancer at some point during their lifetimes (based on 2013–2015 data).“
That makes it very hard to validate small changes and any reasonable study size is going to fall below the noise floor. In other words people pushing those models lack any direct evidence to support them.