Early life triclosan exposure and neurodevelopment of children at 3 years in a prospective birth cohort

Abstract

Background: Early life exposure to triclosan, an emerging endocrine disrupting chemical, may adversely impact childhood neurodevelopment, but limited epidemiologic studies have examined the associations.

Objective: We evaluated the associations between prenatal and postnatal triclosan exposure and child neurodevelopment at 3 years.

Methods: The study included 377 mother-child pairs who participated in Sheyang Mini Birth Cohort Study (SMBCS), a longitudinal birth cohort in China. Triclosan concentrations in maternal and 3-year-old child urine samples were quantified using gas chromatography-tandem mass spectrometry (GC-MS/MS). Gesell Developmental Schedules (GDS) were used to assess child neurodevelopment at 3 years of age. Multivariate linear regression models were applied to estimate associations of prenatal and postnatal urinary triclosan concentrations with children's developmental quotients (DQs).

Results: Detection frequencies of triclosan in maternal and childhood urine samples were 100% and 99.5%, respectively. The median values of prenatal and postnatal urinary triclosan levels were 0.65 and 0.44 μg/L, respectively. One ln-unit increase of maternal urinary triclosan concentration was associated with increase of DQ scores in motor area of children (regression coefficient, β = 0.28, 95% confidence interval, CI: 0.03, 0.54; p = 0.03). In sex-stratified analyses, maternal urinary triclosan levels were significantly related to increases in DQ scores in motor area among boys (β = 0.25, 95%CI: 0.01, 0.50; p = 0.04), while postnatal urinary triclosan concentrations were inversely associated with DQ scores in social area in boys (β = -0.37, 95%CI: -0.72, -0.03; p = 0.03).

Conclusions: The findings suggested that prenatal triclosan exposure predicted increases in motor scores, while postnatal triclosan exposure was related to reductions in social scores of 3-year-old children. These associations were only observed in boys. The biological mechanisms linking triclosan exposure to neurodevelopment await further studies.

Keywords: Biomonitoring; Child neurodevelopment; Prenatal and postnatal exposure; Triclosan.