Lead in saliva from lead-exposed and unexposed children.
BACKGROUND
Whole blood is used for diagnosis of lead exposure. A non-invasive method to obtain samples for the biomonitoring of lead contamination has become a necessity. This study 1) compares the lead content in whole saliva samples (Pb-saliva) of children from a city with no reported lead contamination (Ribeirão Preto, São Paulo State, Brazil) and children of a region notoriously contaminated with lead (Bauru, São Paulo State, Brazil), and 2) correlates Pb-saliva with the lead content in the enamel microbiopsy samples (Pb-enamel) in the case of these two populations.


METHODS
From a population of our previous study that had included 247 children (4- to 6-year-old) from Ribeirão Preto, and 26 children from Bauru, Pb-saliva was analyzed in 125 children from Ribeirão Preto and 19 children from Bauru by inductively coupled plasma mass spectrometry (ICPMS). To correlate Pb-saliva with Pb-enamel, we used Pb-enamel data obtained in our previous study. The Mann-Whitney test was employed to compare the Pb-saliva data of the two cities. Pb-saliva and Pb-enamel values were then Log10 transformed to normalize data, and Pb-saliva and Pb-enamel were correlated using Pearson's correlation coefficient.


RESULTS
Median Pb-saliva from the Ribeirão Preto population (1.64 microg/L) and the Bauru population (5.85 microg/L) were statistically different (p<0.0001). Pearson's correlation coefficient for Log10 Pb-saliva versus Log10 Pb-enamel was 0.15 (p=0.08) for Ribeirão Preto and 0.38 (p=0.11) for Bauru.


CONCLUSIONS
A clear relationship between Pb-saliva and environmental contamination by lead is shown. Further studies on Pb-saliva should be undertaken to elucidate the usefulness of saliva as a biomarker of lead exposure, particularly in children.
Costa de Almeida
Glauce Regina
GR
Department of Morphology, Stomatology and Physiology, Dental School of Ribeirão Preto, University of São Paulo-FORP/USP, Av. do Café, S/N, Monte Alegre, CEP 14040-904, Ribeirão Preto-SP, Brazil. glauce79@yahoo.com.br
Umbelino de Freitas
Clarice
C
Barbosa
Fernando
F
Tanus-Santos
José Eduardo
JE
Gerlach
Raquel Fernanda
RF
D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D007854:Lead / Q000032:analysis* / Q000097:blood; D013058:Mass Spectrometry; D012463:Saliva / Q000737:chemistry*; D018709:Statistics, Nonparametric
D007854:Lead