In Poland around the 1950s, it was observed that miners rarely ever had to deal with any respiratory illnesses. Further research revealed this was due to the anti-inflammatory and antibacterial qualities of the salt.
In today's technology-driven world, we are able to develop a salt cave and recreate the same microclimate that is found in a natural salt mine. This is done through a halogenerator. Salt caves are now developing and becoming very popular all across the world, including the United States.