I love hot springs - seek them out regularly. But the water quality varies greatly.
Best story along these lines for me: Visited Yellowstone in the Summer of 86. Nice place. Asked the rangers about hot springs; "Too dangerous. None around here. Stay away"; yeah, uh, right....geysers, geysers everywhere and no pools in which a butt can sink?
Then I found it; back of a liquor store outside the south entrance; old map..."Huckeberry Hot Springs". Yay! So I drive down this dirt road a ways and park in front of a sign that says, "Danger! Area Closed! No Entry!" Normally this would give me pause, but seeing as how there were a half dozen other cars parked nearby and no one in sight, this must be the place.
A 1/4 mile in turns up a ghost town - old buildings, roads, power poles - all vintage 1930's or so, in reasonably good condition, but completely empty. A couple comes in the opposite direction. "This the hot springs?" "Yeah, just over that rise there." "Sweet!"
I find a nice spot where the hot & cold water mix to my taste and settle in for the afternoon. A few other folk come & go, we share stories, and then, as if in a dream, this guy walks up carrying a six-pack of beerski's. "Want one?" "Hell yeah!" We chit-chat for awhile and it turns out he's a local; fishes & hunts the area, so I ask, "Why the Danger signs?"
"Oh, didn't you know?" "No, what?" "This whole place is a radiation hazard!" DAMN! My twenty-something testicles tightened teenier than rabbit turds as I lifted my bare-ass butt out of the water. "Relax", said Beer Man, "Not enough to fizzle your fecundity unless you live here year-round. They had to close it because the employees were over exposed."
Still, being a properly proselytized pupil of the eighties anti-nuclear movement gave me pause and the scientist in me awoke from an alchohol and dehydration induced stupor; "I don't know, man, seems like rad counts are more about odds than safety levels, you know? But, thanks for the beer!" "Sure, see ya."
I went back in 2002 with the wife & two seemingly normal children. The liquor store and the ghost town are gone, but the springs are still there.
Water meets rock & gets superheated under lots of pressure. Some of the rock dissolves into the water and gets brought back up to the surface. Sometimes what gets dissolved isn't all that healthy.
"Yes, but is it art?" "No, Art is over there, on the couch."