北海道に於ける天然水中弗素濃度に就て

抄録

As one of the most important volatile component of molten magma, fluorine has been repeatedly reported to be present in volcanic exhalations and mineral springs. Hence it seems important, from the geochemical and medical point of view, to study the fluorine contents in the natural waters of mineral spring areas. The author has conducted an extensive survey of the fluorine contents in 83 natural waters of 21 mineral spring areas on Hokkaido.
The mineral waters of Hokkaido contain a higher concentration of fluorine as compared to most fresh waters which normally have 0.1-0.2 p.p.m. content of fluorine. There seems to be no immediate danger to the population using well waters being affected by so called “mottled enamel”. However among those using mineral waters the majority were affected by “mottled enamel”. Yet such enviroment were scarce. In addition and as a result of the authors clinical observations it is highly probable that tooth decay is reduced by a lower concentration of fluorine than hitherto recognized.
The author has used his own medification of J. M. Sanchis's determination method. He recommends his method since the lowest limit of estimation and sharpness in color changes are remarkably clear and in addition preparation of reagents and analytical procedure are simple.