EXPERIMENTAL STUDIES ON CHRONIC FLUORINE POISONING Part I. On development of poisoning, levels of serum calcium and of inorganic phosphor and changes in various organs

Bone changes in residents in the high fluorine zone, which were described by Prof. Dr. Hamamoto, called general attention in the medical world. This study was made based on clinical experiences that sclerotic changes of vertebrae found in patients complaining of lumbago were possibly caused by taking water from well which contained abnormally high concentration of fluorine. 1) Slight degree of mottled teeth and weight loss, averaging 20 gms, were found in rats fed on water containing 13 p. p. m. fluorine for one year. Bone changes, however, were not noticed and no changes were found in levels of serum calcium and inorganic phosphor. 2) Marked mottled teeth developed in rats fed on water containing 100 p. p. m. fluorine for same period, though general condition were not involved. Upper incisor overgrew, though fragile. No marked changes were found in skeletal system and level of serum calcium. Slight increase in serum inorganic phosphor was noticed with concomitant degeneration of renal parenchym suggesting close relation between them. Slight parenchymal degeneration were found in liver, heart, lung, spleen and other organs