Polycyclic aromatic hydrocarbons exposure in early pregnancy on child neurodevelopment

The epidemiological evidence from studies on the impact of exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy on child neurodevelopment is inconclusive. This study aimed to assess the associations of PAHs exposure in early pregnancy and neurodevelopmental outcomes in children aged 6-12 months in a prospective cohort. In this study, we included 172 mother-child pairs with complete data in Tianjin City, China. Ten PAH metabolites were determined in early-pregnancy urine using gas chromatography and tandem mass spectrometry (GC-MS/MS). Child neurodevelopment was measured using the Griffiths Development Scales-Chinese (GDS-C) when children were between 6 and 12 months old. We employed multivariable linear regression, Weighted Quantile Sum (WQS) regression, and Bayesian Kernel Machine Regression (BKMR) to assess the relationships of individual PAH metabolites and mixtures of these metabolites with child neurodevelopment. Multiplicative interactions were analyzed to examine effect modification by child sex. In the multivariable linear regression analysis, six PAH metabolites were found to be negatively associated with personal social scores, while three PAH metabolites showed a negative association with language scores. The WQS model revealed that the PAHs mixture was linked to decreased personal social scores (β = - 4.18, 95% CI = -7.56, - 0.80) and language scores (β = - 4.17, 95% CI = -7.98, -0.37). Furthermore, the BKMR models also indicated the negative associations between the PAHs mixture and personal social scores and language scores. Notably, three PAH metabolites (1-hydroxynaphthalene(1-OHNap), 3-hydroxyfluorene(3-OHFlu), 3+9-hydroxyphenanthrene(3+9-OHPhe)) were identified as important contributors to these associations. All analyses of interactions were null. Exposure to PAHs during early pregnancy, whether individually or as a mixture, demonstrated a negative association with child neurodevelopment outcomes.