The normal levels of fluorine in the bone tissue of Japanese subjects.

The variation of fluorine concentration by sex and age in bones of Japanese subjects was estimated. The subjects had lived in districts virtually with no fluoride in drinking water and air. The rib bone and the iliac crest were selected for investigation. The fluorine concentration in bones was about 100 ppm in dry (fat-free) weight and 200-230 ppm in ash weight from birth to 19 in both sexes, and increased in their twenties, reaching a plateau level in the 60's. The fluorine concentration in rib bones, however, was 610 ppm in dry (fat-free) weight and 1100 ppm in ash weight, which was slightly higher than that in ilia with 530 ppm in dry (fat-free) weight and 960 ppm in ash weight, respectively. The bones of males contained more fluorine than those of females. The concentration of Ca, P and Mg in bone tissue did not correlate with fluorine concentration.