Exposure to phthalates, non-phthalate plasticizers and bisphenols and neurodevelopmental outcomes in school age children from Poland

BACKGROUND AND AIM: Exposures to phthalates, non-phthalate plasticizers and bisphenols may play a role in the development of child behavioral and psychomotor problems. The aim of the study was to evaluate the association between childhood exposures to these compounds and neurodevelopmental outcomes in the REPRO_PL birth cohort (Poland). METHODS: Urine samples were collected at the time of children’s neurodevelopmental assessment (age 7). HPLC-MS/MS was used for the determination of BPA and 21 phthalate metabolites (n=400) and their replacement alternatives BPF, BPS, three metabolites of DEHTP and three metabolites of DINCH (n=150). Behavioral, cognitive and psychomotor development of children were assessed by the Strengths and Difficulties Questionnaire (SDQ) and the Intelligence and Development Scales (IDS). Multivariate linear regression models accounting for sex-specific effects were applied, including the use of stratification and interactive approaches. RESULTS: BPA and BPF were found to be associated with emotional symptoms (0.54 [0.035; 1.0] and 0.93 [0.051; 1.8], respectively), and the latter was additionally associated with total difficulties (2.8 [0.30; 5.2]) and peer-relationship problems (0.90 [0.13; 1.7]) in boys. In addition, boys with higher exposures to DEHTP performed worst for conduct problems (1.1 [0.41; 1.7]) and the pro-social behavior (-1.0 [-1.9; -0.15]). Conversely, among girls, the compounds which were significantly associated with poorer behavioral scores were MMP, ΣDnBP and ΣDiBP. For IDS, higher exposures to BPF were associated to lower scores in Fluid IQ (-6.7 [-12.6; -0.88]) and Cognition (-6.0 [-10.8; -1.3]) in boys. Among girls, however, we found a negative association between DINCH and MMP and mathematical scores, with statistically significant results. CONCLUSIONS: This study indicates that children’s exposure to several replacement compounds of BPA and phthalates, such as BPF and DEHTP, are associated with adverse effects on behavioural and cognitive development of school age children, with a divergent sex-specific effects.