Correlation between concentrations of four heavy metals in cord blood and childhood blood of Jamaican children

Abstract

This study investigated whether the concentrations of four metals [lead (Pb), mercury (Hg), manganese (Mn), and aluminum (Al)] are correlated in cord blood and childhood blood samples from Jamaican children. Cord blood samples were obtained from 21 pregnant women enrolled in the second Jamaican Birth Cohort Study from July 1, 2011 to September 30, 2011, and blood samples were drawn from their children who participated in a follow up study when the children were 4–8 years old. Correlations were assessed by the Pearson or the Spearman’s rank correlation coefficient. The mean ages of children at the childhood visit and their mother at the child’s birth were 5.5 years and 29.8 years, respectively. About 47.6% of children were male. Statistically significant correlations between cord blood and childhood blood concentrations of Pb (r_Spearman =0.45; P = 0.04) and Mn (r_Pearson=0.48; P = 0.03) were found, and these remained significant when adjusted for the child’s sex, age, or both. For Al and Hg, r_Spearman=0.29 and 0.08, respectively, but the correlations were not statistically significant (both P ≥ 0.20). A significant correlation between cord blood and childhood blood Pb concentrations for children 4–8 years old has not been previously reported.

Keywords:

• age-and-sex adjusted
• correlation
• cord blood
• childhood blood
• lead
• manganese
• Jamaica

Acknowledgments

This research is co-funded by the National Institute of Environmental Health Sciences (NIEHS) by a grant (R01ES022165), as well as the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the National Institutes of Health, Fogarty International Center (NIH-FIC) by a grant (R21HD057808) awarded to the University of Texas Health Science Center at Houston. We also acknowledge the support provided by the Child Cohort Study (JA Kids Study), supported by a grant from Inter-American Development Bank (IDB) Project Number (ATN/JF-12312-JA) awarded to the University of the West Indies, Mona Campus, in Jamaica. In addition, we acknowledge the support provided by the Biostatistics/Epidemiology/Research Design (BERD) component of the Center for Clinical and Translational Sciences (CCTS) for this project. CCTS is mainly funded by the NIH Centers for Translational Science Award (NIH CTSA) grant (UL1 RR024148), awarded to the University of Texas Health Science Center at Houston in 2006 by National Center for Research Resources (NCRR), and its 2012 renewal (UL1 TR000371) and another 2019 grant (UL1 TR003167) by the National Center for Advancing Translational Sciences (NCATS.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NICHD, NIH-FIC, NIEHS, IDB, NCRR, or NCATS. We acknowledge that the collection and management of survey data were done using REDCap.^[50] In addition, we acknowledge contributions by colleagues in the Analytical Chemistry Lab at MDHHS for analyzing and storing the cord blood and whole blood samples for the assessments of heavy metal concentrations, under a service contract.

Author contributions

Conceptualization, M.H.R., M.S.-V., K.A.L., and J.B.; methodology, M.H.R., M.S.-V., J.B, and M.L.G.; validation, M.H.R.; formal analysis, M.H.R. and M.H.; investigation, M.H.R., M.S.-V., S.S.-P.; resources, M.H.R. and M.S.-V; data curation, M.H.R., M.S.-V., M.L.G., and S.S.-P.; writing – original draft preparation, M.H.R., M.H. and S.G; writing – review and editing, M.H.R., J.B., M.H., and K.A.L.; visualization, M.H, M.H.R.; supervision, M.H.R.; project administration, M.H.R., M.S.-V., S.S.-P., and S.G; funding acquisition, M.H.R. All authors have read and agreed to the submission of this version of the manuscript for publication.

Conflicts of interest

The authors declare no conflict of interest.