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

Abstract

Early life exposure to triclosan, an emerging endocrine disrupting chemical, may adversely impact childhood neurodevelopment, but limited epidemiologic studies have examined the associations. We evaluated the associations between prenatal and postnatal triclosan exposure and child neurodevelopment at 3 years. 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). 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 0.44μg/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). 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.