Association of both prenatal and early childhood multiple metals exposure with neurodevelopment in infant: A prospective cohort study.

BACKGROUND: Impaired neurodevelopment of children has become a growing public concern; however, the associations between metals exposure and neurocognitive function have remained largely unknown. OBJECTIVES: We systematically evaluated the associations of multiple metals exposure during pregnancy and childhood on the neurodevelopment of children aged 2-3 years. METHODS: We measured 22 metals in the serum and urine among703 mother-child pairs from the Guangxi Birth Cohort Study. The neurocognitive development of children was assessed by the Gesell Development Diagnosis Scale (GDDS; Chinese version). Multiple linear regression models were used to evaluate the relationship between the metals (selected by elastic net regression) and the outcomes. The Bayesian kernel machine regression (BKMR) was used to evaluate the possible joint effect between the multiple metal mixture and the outcomes. RESULTS: Prenatal aluminum (Al) exposure was negatively associated with the fine motor developmental quotient (DQ) (ß = -1.545, 95%CI: 2.231, -0.859), adaption DQ (ß = -1.182, 95%CI: 1.632, -0.732), language DQ (ß = -1.284, 95% CI: 1.758, -0.809), and social DQ (ß = -1.729, 95% CI: 2.406, -1.052) in the multi-metal model. Prenatal cadmium (Cd) exposure was negatively associated with gross motor DQ (ß = -2.524, 95% CI: 4.060, -0.988), while postpartum Cd exposure was negatively associated with language DQ (ß = -1.678, 95% CI: 3.227, -0.129). In stratified analyses, infants of different sexes had different sensitivities to metal exposure, and neurobehavioral development was more significantly affected by metal exposure in the first and second trimester. BKMR analysis revealed a negative joint effect of the Al, Cd, and selenium (Se) on the language DQ score; postpartum Cd exposure played a major role in this relationship. CONCLUSION: Prenatal exposure to Al, Ba, Cd, molybdenum (Mo), lead (Pb), antimony (Sb), and strontium (Sr), and postpartum exposure to cobalt (Co), Cd, stannum (Sn), iron (Fe), nickel (Ni), and Se are associated with neurological development of infants. The first and second trimester might be the most sensitive period when metal exposure affects neurodevelopment.

Gender-specific effects of prenatal mixed exposure to serum phthalates on neurodevelopment of children aged 2-3 years:the Guangxi Birth Cohort Study.

Phthalates have been shown to have adverse effects on neurodevelopment, which may be gender-specific. However, the association between prenatal mixed exposure to phthalates and children's neurodevelopment remains inconsistent. We measured 15 prenatal serum phthalate levels and evaluated children's neurodevelopmental indicators using Gesell Developmental Schedule (GDS) (n = 750). Generalized linear regression was fitted to examine the association. Among boys, mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) had adverse effects on gross motor [odds ratio (OR): 7.38, 95% confidence interval (CI):1.42, 38.46]. For gross motor in boys, joint effect was discovered between mono-2-ethylhexyl phthalate (MEHP) and MEHHP. Moreover, synergistic effects were found for MEHP with vanadium and cadmium, and antagonistic effects for MEHP with magnesium, calcium, titanium, iron, copper, selenium, rubidium, and strontium. We did not find statistically significant relationships in girls. In the 1st trimester, adverse effects were identified between mono-2-ethyl-5-oxoyhexyl phthalate (MEOHP) and adaptation (P = 0.024), and monomethyl phthalate (MMP) with social area (P = 0.017). In the 2nd trimester, MEHHP had adverse effects on social area (P = 0.035). In summary, we found boys may be more vulnerable to the neurotoxicity than girls in gross motor, and we also discovered the detrimental effects of phthalates on children's neurodevelopment in the 1st and 2nd trimesters. Therefore, the supplementation of appropriate elements in the 1st and 2nd trimesters may help reduce the adverse effects of phthalates on children's neurodevelopment, especially among boys.