1. Toxicology. 2010 Apr 30;271(1-2):21-6. Epub 2010 Feb 25.

Fluoride increases lead concentrations in whole blood and in calcified tissues
from lead-exposed rats.

Sawan RM, Leite GA, Saraiva MC, Barbosa F Jr, Tanus-Santos JE, Gerlach RF.

School of Dentistry of Ribeirao Preto, University of Sao Paulo (FORP/USP), Av do 
Café s/n, 14040-904, Ribeirão Preto, SP, Brazil.

Higher blood lead (BPb) levels have been reported in children living in
communities that receive fluoride-treated water. Here, we examined whether
fluoride co-administered with lead increases BPb and lead concentrations in
calcified tissues in Wistar rats exposed to this metal from the beginning of
gestation. We exposed female rats and their offspring to control water (Control
Group), 100mg/L of fluoride (F Group), 30mg/L of lead (Pb Group), or 100mg/L of
fluoride and 30mg/L of lead (F+Pb Group) from 1 week prior to mating until
offspring was 81 days old. Blood and calcified tissues (enamel, dentine, and
bone) were harvested at day 81 for lead and fluoride analyses. Higher BPb
concentrations were found in the F+Pb Group compared with the Pb Group
(76.7+/-11.0microg/dL vs. 22.6+/-8.5microg/dL, respectively; p<0.001). Two- to
threefold higher lead concentrations were found in the calcified tissues in the
F+Pb Group compared with the Pb Group (all p<0.001). Fluoride concentrations were
similar in the F and in the F+Pb Groups. These findings show that fluoride
consistently increases BPb and calcified tissues Pb concentrations in animals
exposed to low levels of lead and suggest that a biological effect not yet
recognized may underlie the epidemiological association between increased BPb
lead levels in children living in water-fluoridated communities.

PMID: 20188782  [PubMed - indexed for MEDLINE]