Bone fluoride concentrations in beluga whales from Canada

Beluga whales (Delphinapterus leucas) from the St. Lawrence Estuary have be en reported to have dental and bone abnormalities. To determine whether the se lesions could be caused by high exposure to fluorides, we measured bone fluoride levels in eight beluga whales stranded on the shores of the St. La wrence Estuary (Quebec, Canada), and in nine beluga whales killed by Inuit hunters in the Hudson Bay (North Western Territories, Canada). In both grou ps, fluoride concentrations were higher than those found in terrestrial mam mals intoxicated by fluorides. Unexpectedly, fluoride concentration was sig nificantly higher in beluga whales from the Hudson Bay ((x) over bar +/- SD : 10,365 +/- 1,098 ppm) than in beluga whales from the St. Lawrence Estuary (4,539 +/- 875 ppm) and was positively correlated with age in the latter p opulation. Differences in diet might explain the differences in fluoride co ncentrations found between these two populations.