Prenatal exposure to legacy PFAS and neurodevelopment in preschool-aged Canadian children: The MIREC cohort.
- DOI
- Language of the publication
- English
- Date
- 2023-05-11
- Type
- Article
- Author(s)
- Goodman, Carly V.
- Till, Christine
- Green, Rivka
- El-Sabbagh, Jana
- Arbuckle, Tye E.
- Hornung, Richard
- Lanphear, Bruce
- Seguin, Jean R.
- Booij, Linda
- Fisher, Mandy
- Muckle, Gina
- Bouchard, Maryse F.
- Ashley-Martin, Jillian
- Publisher
- Elsevier
Abstract
Background: Exposure to perfluoroalkyl substances (PFAS) has been shown to be neurotoxic in experimental studies, but epidemiological evidence linking prenatal PFAS exposure to child neurodevelopment is equivocal and scarce. Objective: To quantify associations between prenatal exposure to legacy PFAS and children's intelligence (IQ) and executive functioning (EF) in a Canadian pregnancy and birth cohort and to determine if these associations differ by child sex. Methods: We measured first-trimester plasma concentrations of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS) in the Maternal-Infant Research on Environmental Chemicals (MIREC) study and assessed children's full-scale (n = 522), performance (n = 517), and verbal (n = 519) IQ using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III). Children's working memory (n = 513) and ability to plan and organize (n = 514) were assessed using a parent-reported questionnaire, the Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P). We quantified associations between individual log2-transformed PFAS exposure and children's IQ and EF using multiple linear regression analyses and evaluated effect modification by child sex. We also used Repeated Holdout Weighted Quantile Sum (WQS) regression models with effect modification by child sex to quantify the effect of combined exposure to all three PFAS chemicals on IQ and EF. All models were adjusted for key sociodemographic characteristics. Results: Geometric mean plasma concentrations (IQR) for PFOA, PFOS and PFHxS were 1.68 (1.10-2.50), 4.97 (3.20-6.20) and 1.09 (0.67-1.60) μg/L respectively. We found evidence of effect modification by child sex in all models examining performance IQ (p < .01). Specifically, every doubling of PFOA, PFOS, and or PFHxS was inversely associated with performance IQ, but only in males (PFOA: B = -2.80, 95% CI: -4.92, -0.68; PFOS: B = -2.64, 95% CI: -4.77, -0.52; PFHxS: B = -2.92, 95% CI: -4.72, -1.12). Similarly, every quartile increase in the WQS index was associated with poorer performance IQ in males (B = -3.16, 95% CI: -4.90, -1.43), with PFHxS contributing the largest weight to the index. In contrast, no significant association was found for females (B = 0.63, 95% CI: -0.99, 2.26). No significant associations were found for EF in either males or females. Conclusions: Higher prenatal PFAS exposure was associated with lower performance IQ in males, suggesting that this association may be sex- and domain-specific.
Plain language summary
Health Canada helps to protect the health of Canadians by assessing and managing the health risks associated with exposure to environmental contaminants. Perfluoroalkyl substances (PFAS) are chemicals that are widely used in numerous consumer products such as cookware, clothing, and food packaging. In animal models, PFAS have been linked to neurotoxic effects but there has been limited research examining prenatal PFAS exposure to child neurodevelopment in humans. Researchers at Health Canada and York University undertook this research to examine associations between prenatal PFAS exposure and children’s intelligence and executive functioning using data from the MIREC study. First-trimester plasma concentrations of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulphonic acid (PFHxS) were measured in the Maternal-Infant Research on Environmental Chemicals (MIREC) study. Between the ages of 3-4, children’s IQ, memory, and ability to Plan/Organize were assessed. The researchers quantified associations between PFAS exposure and children’s neurodevelopmental outcomes using statistical models and observed that the associations differed between boys and girls. Specifically, higher PFAS exposure was associated with lower IQ in boys but not girls. Future research is needed to confirm these findings.
Subject
- Health,
- Health and safety