Some things can be benefitted or cured by low level radiation
That is an aspect of the Rickover effect.
Just pay attention to science. Radiation; penetrating/ionizing radiation preferentially kills fast growing cells. That is why it is so dangerous to sperm and eggs.
But, bugs are also fast growing — so they can get an advantage over the immune system. So, radiation in low levels whacks the bugs trying to outpopulate the incoming immune system attacks. The bugs lose.
This was shown again and again in sub crews. They came home perfectly healthy — and immediately caught a cold.
Very few phenoms display LNT. Almost no evidence. But, it is conservative to assume it. And, it is expensive (time consuming) to disprove it. So, the lazy and ones who profit by assuming it go for it.