Abstract
The fluorine content in city water in Japan was determined by the zirconium eriochrome cyanin R method. The content of fluorine ranged from 0.021 p. p. m. to 0.432 p. p. m. in Tokyo, 0.052 p. p. m. to 0.165 p. p. m. in Nagoya and in Keihanshin district 0.130 p. p. m. to 0.840 p. p. m. In other districts the maximum content was 1.080 p. p. m. (Saijo city in Ehime Prefecture).
Daily intake of fluorine by the individual from drinking water was estimated at about 0.5mg., which was one-tenth of total intake.
