One thing that probably confuses many is the mechanism by which ionizing radiation causes cancer. A lot of non-ionizing radiation, such as visible light, wifi,

One thing that probably confuses many is the mechanism by which ionizing radiation causes cancer. A lot of non-ionizing radiation, such as visible light, wifi, radio, or infrared, will only excite the molecules in your body, causing an increase in heat. Obviously, too much heat is bad for you, but it won't cause cancer. It will just cook you like meat in a microwave oven. Ionizing radiation, on the other hand, has a small chance of popping an atom out of a molecule in your body. It's the energy of single particles that matters, not the number of them (although you can certainly be cooked alive by enough ionizing radiation). If an atom is popped out of the right molecule (i.e. the DNA stored in one of your cells) in exactly the right place (e.g. the portions that suppress out-of-control replication) then you can get cancer. That mistake in your DNA might be repaired or the cell might simply die. It might be fine for a while, but that one mistake could lead to compounding errors in future cell divisions, eventually leading to cancer. There are many forms of cancer, but their severity is not a function of how much radiation a person has been exposed to. Someone with a lot of exposure to man-made radiation sources might get a slow growing tumor in a non-vital area while a person who spent his life a thousand kilometers from civilization could get an aggressively spreading form of cancer in an inoperable area. So, can light exposure to radiation be therapeutic? Probably not. If there are benefits to the treatments at Radhausberg, they are likely either due to some other factor or the placebo effect. The radiation is at a mostly harmless level for visitors, but it's not impossible that this could be the place where you get cancer. I'd be more concerned for the staff who are exposed year-round. The exposure received by nuclear plant workers is meticulously monitored and is likely far lower than what the workers at Radhausberg are receiving. 1 mSv is in the range of a medical diagnostic test, but multiply that by 2-3 hundred per year for several years and you get a pretty big dose. Perhaps the most ironic thing related to this story is the fact that background radiation exposure for typical Germans has probably increased significantly in the last few years. Germany's main source of electricity is coal power, and they're relying on it more heavily than before now that they've shut down their nuclear reactors. For power plants of the same capacity, radioactive emissions are typically two orders of magnitude higher for coal power plants than for nuclear power plants.