Childhood exposure to per- and polyfluoroalkyl substances (PFAS) and neurobehavioral domains in children at age 8 years

Background: Toxicological studies have raised concerns regarding the neurotoxic effects of per- and polyfluoroalkyl substances (PFAS). However, observational evidence from human studies investigating the association between childhood PFAS and neurobehavior is limited and remains unclear. Objectives: To examine whether childhood PFAS concentrations are associated with neurobehavior in children at age 8 years and whether child sex modifies this relationship. Methods: We used data from 208 mother-child dyads in the Health Outcomes and Measures of the Environment (HOME) Study, a prospective pregnancy and birth cohort (Cincinnati, OH, USA). We quantified PFAS in child serum at 3 and 8 years. We assessed neurobehavioral domains using the Behavior Assessment System for Children-2 at 8 years. We used multiple informant models to estimate score changes per ln-increase in repeated PFAS concentrations. Results: Childhood PFAS were not associated with Externalizing or Internalizing Problems at 8 years. However, we noted effect measure modification by sex, with higher scores in Externalizing Problems among males per ln-unit increase in perfluorononanoate (PFNA) at 3 years (beta = 4.3 points, 95% CI: 1.0, 7.7) while females had lower scores (beta =-2.8 points, 95% CI:-4.7,-1.0). More Internalizing Problems were observed among males per lnunit increase in concurrent PFNA concentrations (beta = 3.7 points, 95% CI: 0.7, 6.8), but not in females (beta =-1.7 points, 95% CI:-4.6, 1.2). Childhood PFNA concentrations were associated with lower scores for attention problems and activity of daily living. Conclusion: While findings do not consistently support an association between childhood PFAS serum concentrations and neurobehavior, child sex may play a role in this relationship.

Automated summary

This study found no association between childhood PFAS serum concentrations and neurobehavior in 8-year-old children. However, there was evidence that child sex may modify this relationship, with higher Externalizing Problems scores in boys with increased PFNA concentrations at 3 years, and more Internalizing Problems in boys with concurrent PFNA concentrations, but not in girls.