Determining prenatal, early childhood and cumulative long-term lead exposure using micro-spatial deciduous dentine levels.
The aim of this study was to assess the validity of micro-spatial dentine lead (Pb) levels as a biomarker for accurately estimating exposure timing over the prenatal and early childhood periods and long-term cumulative exposure to Pb. In a prospective pregnancy cohort sub-sample of 85 subjects, we compared dentine Pb levels measured using laser ablation-inductively coupled plasma mass spectrometry with Pb concentrations in maternal blood collected in the second and third trimesters, maternal bone, umbilical cord blood, and childhood serial blood samples collected from the ages of 3 months to ≥6 years. We found that Pb levels (as 208Pb:43Ca) in dentine formed at birth were significantly associated with cord blood Pb (Spearman ρ = 0.69; n = 27; p<0.0001). The association of prenatal dentine Pb with maternal patella Pb (Spearman ρ = 0.48; n = 59; p<0.0001) was stronger than that observed for tibia Pb levels (Spearman ρ = 0.35; n = 41; p<0.03). When assessing postnatal exposure, we found that Pb levels in dentine formed at 3 months were significantly associated with Pb concentrations in children's blood collected concurrently (Spearman ρ = 0.64; n = 55; p<0.0001). We also found that mean Pb concentrations in secondary dentine (that is formed from root completion to tooth shedding) correlated positively with cumulative blood lead index (Spearman ρ = 0.38; n = 75; p<0.0007). Overall, our results support that micro-spatial measurements of Pb in dentine can be reliably used to reconstruct Pb exposure timing over the prenatal and early childhood periods, and secondary dentine holds the potential to estimate long-term exposure up to the time the tooth is shed.
Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Faculty of Dentistry, University of Sydney, Sydney, Australia.
Manish
M
Arora
Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Faculty of Dentistry, University of Sydney, Sydney, Australia.
Christine
C
Austin
Faculty of Dentistry, University of Sydney, Sydney, Australia.
Babak
B
Sarrafpour
Office of the Director, National Institute of Public Health, Cuernavaca, Morelos, México.
Mauricio
M
Hernández-Ávila
Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
Howard
H
Hu
Department of Preventive Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
Robert O
RO
Wright
Division of Statistics, Center for Evaluation Research and Surveys, National Institute of Public Health, Cuernavaca, Morelos, México.
Martha Maria
MM
Tellez-Rojo
D002675:Child, Preschool; D002947:Cities; D003804:Dentin / Q000737:chemistry*; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007854:Lead / Q000032:analysis* / Q000097:blood; D013058:Mass Spectrometry; D008431:Maternal-Fetal Exchange; D008800:Mexico; D011247:Pregnancy; D018709:Statistics, Nonparametric; D014094:Tooth, Deciduous / Q000737:chemistry*
D004785:Environmental Pollutants; D007854:Lead