A comparison of blood and toenails as biomarkers of children's exposure to lead and their correlation with cognitive function

Julianna Dantzer, Patrick Ryan, Kimberly Yolton, Patrick J. Parsons, Christopher D. Palmer, Kim Cecil, Jason M. Unrine

Research output: Contribution to journalArticlepeer-review

12 Scopus citations

Abstract

This study sought to compare lead (Pb) concentrations in toenails and blood and to investigate the association of each biomarker with children's cognitive function. Toenails and whole blood samples were collected from 224 twelve-year-old children, and their full-scale intelligence quotient (FSIQ) was assessed using the Wechsler Intelligence Scale for Children–4th edition. Inductively coupled plasma-mass spectrometry was used to determine blood (BPb) and toenail (TPb) Pb concentrations. Log BPb and Log TPb were significantly correlated (r2 = 0.49, p < 0.001). In unadjusted analyses, both log-transformed BPb and TPb were significantly associated with decreased FSIQ, but BPb accounted for approximately quadruple the FSIQ scores’ variability than log-transformed TPb (model R2 = 0.12 and R2 = 0.03, respectively). After adjusting for neighborhood deprivation, caregiver intelligence (assessed with the Wechsler Abbreviated Scale of Intelligence–2nd edition), and child BMI, BPb remained significantly associated with decreased FSIQ, while TPb did not (p = 0.16). These results suggest that while concentrations of Pb in blood and toenails are correlated, TPb does not predict cognitive outcomes at these exposure levels. With caution and in conjunction with BPb, TPb may be used as a population-based biomarker of Pb exposure.

Original languageEnglish
Article number134519
JournalScience of the Total Environment
Volume700
DOIs
StatePublished - Jan 15 2020

Bibliographical note

Funding Information:
The authors gratefully acknowledge S. Shrestha and H. Swanson. This study was funded by the National Institutes of Health under 5R25ES027684 and P30ES026529 . Funding for the CCAAPS cohort was provided by the National Institute of Environmental Health Sciences under R01ES019890 and R01ES11170 . The authors would like to thank Chris Wolfe, Rachel Wolf, and Zana Percy for assisting with data collection and study coordination. This study was funded by the National Institute of Envrionmental Health Sciences under 5R25ES027684 and P30ES026529 . Funding for the CCAAPS cohort was provided by the National Institute of Environmental Health Sciences under R01ES019890 and R01ES11170 . The authors thank S. Shrestha. It’s contents are solely the responsibility of the authors and do not necessarily represent the views of the NIEHS.

Publisher Copyright:
© 2019 Elsevier B.V.

Keywords

  • Biomarker
  • Children's exposure
  • Lead
  • Toenail

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution

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