Radioactive hot springs?
I have come across a hot spring that is advertising it's purported health benefits, and one of the reasons it provided was that it purports that it's water is radioactive.
Looking further into this, I see that radon is found in some (all?) hot springs and in the early 1900s, it was understood to be the beneficial aspect of the hot springs and radon was used in a variety of health products.
All this is interesting, but what I haven't been able to get a clear answer on is whether the water in that hot spring really is radioactive, is it radon, and at what estimated amount might it be present in. It seems there is some evidence that hot springs are often healing, and I doubt very much it's the radium. Is it present in such low amounts compared to non-radioactive minerals that it can be safely ignored? Or would going to a hot spring for health benefits be counteractive?
Does anyone have any more specific information about radioactivity and hot springs? Do they all emit radon, and is it quite a lot?