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

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.