Prenatal and childhood exposure to perfluoroalkyl substances (PFAS) and measures of attention, impulse control, and visual spatial abilities

Abstract

Background: Despite evidence from toxicological studies describing the potential neurotoxicity of perfluoroalkyl substances (PFAS), their role in neurodevelopment remains uncertain amid inconsistent findings from epidemiological studies.

Methods: Using data from 218 mother-child dyads from the Health Outcomes and Measures of the Environment Study, we examined prenatal and childhood (3 and 8 years) serum concentrations of four PFAS and inattention, impulsivity, and visual spatial abilities. At 8 years, we used the Conners' Continuous Performance Test-II to assess attention and impulse control and the Virtual Morris Water Maze (VMWM) to measure visual spatial abilities.

Results: In multiple informant models, there was no evidence to indicate that prenatal or childhood PFAS are associated with attention. However, there was an inverse association between prenatal ln-perfluorooctanoate (PFOA) and errors of commission (β = -2.0, 95% Confidence Interval [CI] -3.8, -0.3). Ln-perfluorononanoate (PFNA) at 3 years was associated with longer (poorer) VMWM completion times of 3.6 seconds (CI 1.6, 5.6). However, higher concurrent concentrations of ln-perfluorohexane sulfonate (PFHxS) (β = -2.4 s, 95% CI -4.4, -0.3) were associated with shorter (better) times. Higher prenatal PFHxS was positively associated with percentage of traveling distance in the correct quadrant (β = 4.2%, 95% CI 0.8, 7.7), indicating better performance.

Conclusion: Findings were mixed for prenatal and childhood PFAS concentrations and visual spatial abilities. There is not enough evidence to support that PFAS are associated with visual spatial abilities as assessed by the VMWM or CPT-II measures of inattention or impulsivity in children at age 8 years.

Keywords: Attention; Impulse control; Impulsivity; Neurodevelopment; Perfluoroalkyl substances (PFAS); Visual spatial abilities.

Copyright © 2018 Elsevier Ltd. All rights reserved.

Figures

Figure 1.

Estimated score differences and 95% CIs in CPT-II measures of inattention and impulsivity by a ln-increase in serum concentrations of PFAS in each exposure assessment window, HOME Study. Adjusted by maternal age, race/ethnicity, household income, maternal smoking status, maternal alcohol consumption, maternal depression, HOME Score, marital status, maternal marijuana use, maternal IQ, maternal serum PCBs, maternal blood lead levels, and child sex.

Figure 2.

Estimated mean differences and 95% CIs in VMWM measures by a ln-increase in serum concentrations of PFAS in each exposure assessment window, HOME Study. Adjusted by maternal age, race/ethnicity, household income, maternal smoking status, maternal alcohol consumption, maternal depression, HOME Score, marital status, maternal marijuana use, maternal IQ, maternal serum PCBs, maternal blood lead levels, and child sex. Higher values on VMWM block trials indicate poorer performance. Lower values on VMWM probe trials indicate poorer performance.

Figure 3.

Estimated associations between prenatal and childhood serum concentrations of PFAS (ng/mL) and CPT-II and VWMW measures at 8 years by child sex, HOME Study. Adjusted by maternal age, race/ethnicity, household income, maternal smoking status, maternal alcohol consumption, maternal depression, HOME Score, marital status, maternal marijuana use, maternal IQ, maternal serum PCBs, maternal blood lead levels, and child sex.