For centuries, in Bulgaria, since Roman times, people have been bathing in slightly radioactive water to treat osteoarthritis. I'm not sure how this is news or an invention when it's been around for centuries and has been the standard of care in Bulgaria for decades. There are sanatoriums and spa centers in Pavel Banya, Bulgaria [0], and I know many friends who go there once or twice a year for treatments and swear they couldn't live without them!
[0]: https://pavelbanyagrand.com/en/the-healing-mineral-water-in-...