Prenatal exposure to arsenic and neurobehavioral development of newborns in China

The link between arsenic exposure and deficits in children's neurodevelopment has been suggested, but it remains unclear regarding the arsenic-related effects on the developing brain in early life. To investigate the associations of in utero arsenic exposure with neonatal neurobehavioral development, we conducted a cross-sectional study of 892 mother-infant pairs from 10 hospitals of different levels in Shanghai, China. The concentrations of arsenic were determined in cord blood samples. Neurobehavioral measures were administered at 3 days postpartum in full-term newborns using the neonatal behavioral neurological assessment (NBNA). Logistic regression models were used to estimate odds ratios for dichotomous NBNA outcomes. After adjusting for potential confounders, a natural log unit (ln-unit) increase in cord blood arsenic was associated with 90% increased odds of low NBNA score (95% confidence interval [CI]: 1.62, 2.23). As for clusters, each ln-unit arsenic increase was associated with 47% increased odds of low score for behavior (95% CI: 1.31, 1.66) and 36% increased odds of low score for passive muscle tone (95% CI: 1.23, 1.51). Odds ratios comparing extreme tertiles were 8.62 (95% CI: 4.19, 17.8) for total scale, 3.69 (95% CI: 2.35, 5.82) for behavior, and 3.32 (95% CI: 2.21, 4.97) for passive tone (all p-trend < 0.001). Stratified analyses showed that these associations were strengthened in newborns of mothers over 29 years of age. Our results provide evidence for an inverse association between low-level prenatal arsenic exposure and neurobehavioral performance of newborns, particularly among those born to older mothers. Further studies are warranted to confirm these findings and to determine whether such decrements in early neurodevelopment persist in later childhood.