Abstract
We simulated a hot spring condition using the mineral powder and measured the radioactivities and negative air ions in some conditions, to elucidate the various characteristics of the radioactivity and negative air ion originated from the Badgastein (Austria) radon hot spring. In the result, the radioactivity of the uranium series nuclides(214Bi) in the mineral was 95 times of that of the thorium series nuclides(208Tl). For the pH (3-11) dependence of the leaching nuclides from the mineral in water, the uranium series nuclides (214Bi, 214Pb) and the thorium series nuclides (212Pb) were well leached on the strong acid side than on the alkaline side. Moreover, there were many negative air ions originated from the mineral in the place within 10cm away from the mineral surface. This suggested that most negative ions exist within the range of the radiated α rays. Negative air ions increased with increasing atmospheric relative humidity (35-60%). This suggested that negative air ions stably existed in the hydration type such as O2-(H2O)n. Furthermore, for the hydrous rate dependence of the negative air ions originated from the mineral, the negative air ions without supernatant fluid were larger than those with supernatant fluid, because α rays ionized water on the surface of the mineral.
