Abstract
Fluorine contents and total hardnesses of municipal water supply in 102 principal cities in Japan were determined by SPADNS-zirconium method and EDTA method.
1) Fluorine contents of water ranged generally from 0.05 to 0.2 ppm. Cities with common water supply containing over 0.2 ppm of fluorine were; Kumamoto (0.23), Toyonaka (0.27), Tsushima (0.29), Takarazuka (0.32), Kyoto (0.62-experimentally fluoridated-Yamashina area) and Kasaoka (1.2-1.3 ppm).
2) Total hardnesses of water (expressed as CaCO3) ranged generally from 40 to 100 ppm; most of them appeared to belong to soft water. In some cities, total hardnesses were above 250 ppm, e. g. Mobara (256.7) and Kasaoka (280.3ppm). Itoigawa was supplying moderately hard water (184.1 ppm) and there were eleven other cities distributing slight hard water (100-150 ppm).
