Using eye tracking to evaluate cognitive and visual outcomes of early life phenol exposure.

Introduction: Studies on behavioral effects of synthetic phenols have often relied on parent-reported questionnaires and primarily focused on prenatal exposure.

Aims: We examined associations between prenatal and infancy phenol exposures and objective measures of child visual behavior and cognitive function at 2 years of age.

Methods: At age 2, 151 children from the SEPAGES mother-child cohort completed eye-tracking tasks assessing four indicators: fixation duration (attentional control), novelty preference (visual recognition memory), time spent looking at eyes (social attention), and reaction time (processing speed).Phenol concentrations (two bisphenols, three parabens, benzophenone-3, triclosan) were measured in multiple urine samples collected from mothers (second and third trimesters; median: 42 samples per woman) and infants (2 and 12 months; median: 7 samples).

Results: No associations were found with ∑parabens. However, individual parabens showed significant associations: ethylparaben at third trimester (T3) and 12 months (M12) was linked to shorter reaction time; at 2 months (M2), it was associated with reduced time spent looking at eyes. Propylparaben at T2 and T3 correlated with increased time spent looking at a novel face, especially in boys. Bisphenol S at T2 was associated with reduced reaction time; at M12, infants with detectable bisphenol S was linked to more time spent looking at eyes.

Conclusion: Several associations observed indicate that increased phenol exposure sometimes correlated with improved eye-tracking scores. These findings align with prior literature on phenol exposure and ASD symptoms, which highlight variability by exposure window and phenol type.Given limited research and typically small sample sizes, further studies using objective markers and clinical assessments are necessary.