Prenatal Metals Exposure and pre-adolescents’ Emotional and Behavioral Problems

Emotional and behavioral problems during childhood raise the risk of subsequent developmental of mental disorders. Our aim was to study the association between maternal metal and trace element concentrations during gestation and these problems in 9 year-old children. The study sample comprised Spanish mother-child pairs in the INMA project (n = 1003). Metals and trace elements (As, Cd, Co, Cu, Mo, Ni, Pb, Sb, Se, Tl and Zn) were measured in urine samples collected during pregnancy. Inorganic As metabolites were speciated in a subsample (n = 729). Emotional and behavioral problems were assessed using the Child Behavior Checklist (CBCL) composed of three scales: internalizing, externalizing and total problems. Sociodemographic, dietary and exposure to other environmental pollutants were obtained through questionnaires. Single nucleotide polymorphisms in brain- and metabolism-related genes APOE , BDNF , GSTP1 , and PON1 were determined in cord blood. Multivariate negative binomial models were used. The interaction with sex and genotypes was evaluated including interaction terms. A multi-element analysis was carried out by a principal component analysis. Higher concentrations of Cu, monomethylarsonic acid, and Pb during pregnancy were associated with an increased incidence ratio risk (IRR) between 4.6 and 7.5% for internalizing and externalizing problems for all three CBCL scales in the children. Increasing Mo, Ni and Co concentrations were associated with higher IRR for internalizing problems (up to 8%), and Cd for externalizing problems (6.7%). Modifications by sex and genotypes were found for several associations. Multi-element analysis associated multiple metals and trace elements (Ni, Cu, Se, Cd and Pb) with higher internalizing problems.