Research Studies Study Tracker On the relation between the distribution of endemic goiter and the fluorine content of natural water in Hidaka Province, Hokkaido. On the relation between the distribution of endemic goiter and the fluorine content of natural water in Hidaka Province, Hokkaido. January 14, 2020 | Folia Pharmacol Jpn | Hidehiko T. | 54:225-229. Thyroid Gland Human Study AbstractNo abstract available.