Prenatal and childhood exposure to poly- and perfluoroalkyl substances (PFAS) and cognitive development in children at age 8 years.

Toxicological studies indicate that poly- and perfluoroalkyl substances (PFAS) may be neurotoxic, but human studies have yet to provide compelling evidence for PFAS' impact on cognitive abilities. To test whether prenatal and childhood PFAS are associated with cognitive abilities at 8 years and whether sex modifies these associations. We included 221 mother-child pairs from the Health Outcomes and Measures of the Environment (HOME) Study, a birth cohort in Cincinnati, OH (USA). We quantified PFAS in maternal serum at 16 ± 3 weeks gestation and in child serum at 3 and 8 years. We used the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) at age 8 years, assessing Full Scale IQ (FSIQ), verbal comprehension, perceptual reasoning, working memory, and processing speed. We used multiple informant models to estimate covariate-adjusted differences in WISC-IV scores by repeated ln-transformed PFAS. Prenatal and childhood perfluorooctane sulfonate (PFOS) and perfluorohexane sulfonate (PFHxS) were not associated with WISC-IV measures. We observed an increase of 4.1-points (95% CI 0.3, 8.0) and 5.7-points (95% CI 1.2, 10.2) in working memory with 1-ln unit increase in prenatal perfluorooctanoate (PFOA) and perfluorononanoate (PFNA), respectively. In addition, PFNA at 3 years was associated with better FSIQ and perceptual reasoning. Child sex modified the relationship between prenatal PFOA and FSIQ; the association was positive in females only. Sex also modified the association between concurrent PFOS and FSIQ, with males having higher scores. We did not observe adverse associations between prenatal and childhood PFAS and cognitive function at age 8 years. • PFOS and PFHxS were not associated with Full Scale IQ (FSIQ) at 8 years. • Prenatal PFOA and PFNA were positively associated with working memory at 8 years. • Child sex modified prenatal PFOA associations, with higher FSIQ scores in females. • We observed higher scores on several WISC scales in males, but not in females. • Findings do not support that PFAS are adversely associated with cognitive function. [ABSTRACT FROM AUTHOR]