Prenatal exposure to benzotriazoles and benzothiazoles and child neurodevelopment: A longitudinal study

Benzotriazoles (BTRs) and benzothiazoles (BTHs) are emerging benzo-heterocyclic compounds that may induce neurotoxicity. However, the effect of prenatal exposure to BTs (BTRs and BTHs) on child neurodevelopment has not been elucidated. We aimed to explore the associations between maternal urinary concentrations of BTs in single or in mixture with child neurodevelopment at the age of two. This study recruited 513 mother-child pairs based on a birth cohort from 2014 to 2015 in Wuhan. Maternal urinary concentrations of eight BTs (four BTRs and four BTHs) in the first, second, and third trimesters were measured. The mental development index (MDI) and psychomotor development index (PDI) of children, as two indexes of neurodevelopment, were assessed at two years old by the Bayley Scales. In the analyses of single BTs, prenatal average tolyltriazole (TTR) exposure level was associated with decreased boys' MDI scores (β = −2.84, 95 % CI: −5.11, −0.57) and prenatal average 1-H-benzotriazole (1-H-BTR) exposure level was associated with decreased boys' PDI scores (β = −1.44, 95 % CI: −2.70, −0.17), respectively. Maternal urinary concentrations of benzothiazole (BTH) in the 1st trimester (β = −1.79, 95 % CI: −2.78, −0.80), 2nd trimester (β = −1.14, 95 % CI: −2.19, −0.09), and the prenatal average exposure (β = −2.15, 95 % CI: −3.69, −0.61) were also negatively associated with boys' PDI scores. However, no significantly negative association was observed among girls. In the further mixture analysis, the quantile g-computation model found a significant negative association between prenatal average concentrations of BTs in mixture and boys' PDI scores [β = −4.80 (95 % CI: −9.08, −0.52)], and BTH weighted the highest in the negative association. As far as we know, this is the first research to estimate the effect of prenatal exposure to BTs on child neurodevelopment. The findings showed that prenatal exposure to BTs was negatively associated with neurodevelopment among boys, suggesting that the associations may be modified by infant sex.