Halotherapy (salt therapy) is related to speleotherapy, yet it is based on a different principle. The similarity obviously lies in the fact that old mines are for medicinal treatments. However, we are dealing here with salt mines. Salt is hygroscopic and binds any moisture from the air so that the humidity is 0 %. Whether the CO2 level is elevated depends on the ventilation, usually it is only slightly elevated. The main factor is probably the salt dust in the air, which is absorbed by the mucous membranes when breathing. Besides respiratory diseases, salt also helps with chronic skin diseases.
Halotherapy has not yet gained much acceptance in the West, but in Eastern Europe and Russia it has been carried out successfully in salt mines for decades. However, salt is used in many medical therapies, cures at the sea, spa clinics at the Dead Sea in Israel, and artificial salt caves are now well recognised. Nevertheless, medical proof of their effectiveness has not been provided to the satisfaction of orthodox physicians here either.