TY - JOUR
T1 - A comparison of blood and toenails as biomarkers of children's exposure to lead and their correlation with cognitive function
AU - Dantzer, Julianna
AU - Ryan, Patrick
AU - Yolton, Kimberly
AU - Parsons, Patrick J.
AU - Palmer, Christopher D.
AU - Cecil, Kim
AU - Unrine, Jason M.
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/1/15
Y1 - 2020/1/15
N2 - 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.
AB - 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.
KW - Biomarker
KW - Children's exposure
KW - Lead
KW - Toenail
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UR - http://www.scopus.com/inward/citedby.url?scp=85074389630&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2019.134519
DO - 10.1016/j.scitotenv.2019.134519
M3 - Article
C2 - 31698272
AN - SCOPUS:85074389630
SN - 0048-9697
VL - 700
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 134519
ER -