Fluoride Action Network


Nodular bone lesions were identified in three species of fruit bat in the Metropolitan Toronto Zoo collection: 25 of 43 Indian fruit bats (Pteropus giganteus), eight of eight grey-headed flying foxes (P. poliocephalus), and seven of 45 Egyptian fruit bats (Rousettus aegyptiacus). The condition was investigated by retrospective study of clinical and necropsy records, by regular physical examination, radiography, and blood sampling of bats currently in the collection, and by postmortem examination. Bone from necropsy specimens had markedly raised fluoride levels (3,300 ± 1,100 ppm) compared with similar bone samples from another collection (300 ± 50 ppm). Samples of the fruit bat diet contained fluoride at levels higher than the recommended dietary intake. Consequently, the osteoproliferation was attributed to fluorosis.