Most of the radioactivity from uranium ore comes from radium impurities, and radium decays to radon, a gas. So, yes, it's entirely plausible for there to have b

Most of the radioactivity from uranium ore comes from radium impurities, and radium decays to radon, a gas. So, yes, it's entirely plausible for there to have been in an inhalation hazard. Though if anyone should be concerned it's the staff, not the tourists.