Prenatal and childhood exposure to mixtures of environmental chemicals and adolescence attentional problems: a triangulation study.

BACKGROUND

Exposure to environmental chemicals is suspected to influence attentional function, yet causal evidence is inconsistent. We triangulated multiple lines of evidence to estimate the effects of prenatal and childhood exposure to environmental chemicals on adolescent attention problems.

METHODS

We followed 1,658 participants in the European Human Early-Life Exposome cohort. Per- and polyfluoroalkyl substances (PFAS), metals, phenols, and phthalate and organophosphate pesticide (OPP) metabolites were measured during pregnancy and childhood. Adolescent attention problems were evaluated with the Child Behavior Checklist. Evidence was triangulated across single-pollutant regression models, negative-control designs, instrumental-variable (IV) regression and Mendelian Randomization (MR). We estimated mixture effects using the parametric g-formula.

RESULTS

In single exposure models, higher levels of several chemicals were associated with fewer attentional problems (prenatal PFOS, β0→1 and 95 % confidence interval (CI) for a unit increase from 0 to 1: -0.86 (-1.63, -0.09); prenatal PFHxS: -1.32 (-2.44, -0.21); childhood BUPA: -0.78 (-1.27, -0.29)). Higher levels of prenatal BPA and childhood DEP were instead associated with more attentional problems (0.96 (0.02, 1.89) and 0.56 (-0.05, 1.16), respectively). IV regression supported the association of childhood DEP (2.80 (0.86, 4.70)); MR yielded little evidence for causality. Negative-control analyses suggested little to no residual confounding by socio-economic status. A joint increase from the 10th to the 90th percentile in the components of the prenatal PFAS mixture was associated with fewer attentional problems in females (marginal contrast and 95 % CI: -0.37 (-0.64, -0.10)).

CONCLUSIONS

Triangulation of multiple causal designs suggests that childhood exposure to the OPP metabolite DEP may impair adolescent attentional function.