The effect of paraben exposure on cognitive and behavioral outcomes in school children

Parabens are endocrine disruptors (EDCs) whose possible neurotoxicity has not been well explored. This study evaluated the relationship between long-term exposure to parabens, quantified in hair, and cognitive and behavioral performance in schoolchildren in Granada (Spain) using the Wechsler Intelligence Scale for Children-V (WISC-V) and Behavior Assessment System for Children-3 (BASC-3) questionnaires, respectively. A total of 401 children aged 6-12 years (2020-2024) were recruited. Among them, 102 completed the WISC-V and 101 the BASC-3, apart from providing a hair sample to determine six parabens by UHPLC-MS/MS. Associations between exposure to parabens and their effects on neurodevelopment were compared considering high and low exposure (median), in the general population and by sex. Logistic regressions were adjusted for sex, age, BMI and parental educational level. Lower scores on WISC-V indices, specifically on the Fluid Reasoning Index (FRI), Verbal Comprehension Index (VCI), and Full-Scale Intelligence Quotient (FSIQ) were observed among males with the highest exposure to ethylparaben (EthPB). Regarding the behavioral level (BASC-3), the stratification by sex shows a higher likelihood, aggressiveness (OR = 6.08; p = 0.022), conduct problems (OR = 10.10; p = 0.010), behavioral symptom index (OR = 13.76; p = 0.012), and disruptive behavior index (OR = 11.45; p = 0.006) in males exposed to EthPB. In conclusion, our findings suggest that exposure to different parabens may be associated with differences in certain cognitive and behavioral domains assessed by standardized and validated tools (WISC-V and BASC-3). Moreover, sex-stratified analyses modified the relationship between paraben exposure and behavioral domains, reinforcing the presence of sex-specific effects. The design of the study does not allow us to establish causality between exposure to these EDCs and a neurotoxic effect.