Dental fluorosis and skeletal fluoride content as biomarkers of excess fluoride exposure in marsupials
Clare Death a,⁎, Graeme Coulson b, Uwe Kierdorf c, Horst Kierdorf c, William K. Morris d, Jasmin Hufschmid a
a Faculty of Veterinary Science, The University of Melbourne, 250 Princess Hwy., Werribee, Victoria, 3030, Australia
b School of BioSciences, The University of Melbourne, Royal Parade, Parkville, Victoria 3010, Australia
c Department of Biology, University of Hildesheim, Universitätsplatz 1, 31141 Hildesheim, Germany
d The Quantitative & Applied Ecology Group, School of BioSciences, The University of Melbourne, 3010
ABSTRACT
Particulate and gaseous fluoride emissions contaminate vegetation near fluoride-emitting industries, potentially
impacting herbivorous wildlife in neighboring areas. Dental fluorosis has been associated with consumption of
fluoride-contaminated foliage by juvenile livestock and wildlife in Europe and North America. For the first
time, we explored the epidemiology and comparative pathology of dental fluorosis in Australian marsupials residing near an aluminium smelter. Six species (Macropus giganteus, Macropus rufogriseus, Wallabia bicolor,
Phascolarctos cinereus, Trichosurus vulpecula, Pseudocheirus peregrinus) demonstrated significantly higher bone
fluoride levels in the high (n = 161 individuals), compared to the low (n = 67 individuals), fluoride areas (p b
0.001). Necropsy examinations of all six species from the high-fluoride area near the smelter revealed dental lesions considered characteristic of dental fluorosis in eutherian mammals. Within the high-fluoride area, 67% of
individuals across the six species showed dental enamel lesions, compared to 3% in the low-fluoride areas. Molars
that erupted before weaning were significantly less likely to display pathological lesions than those developing
later, and molars in the posterior portion of the dental arcade were more severely fluorotic than anterior molars
in all six species. The severity of dental lesions was positively associated with increasing bone fluoride levels in all
species, revealing a potential biomarker of excess fluoride exposure.