BACKGROUND: We have previously reported the inverse associations between in utero levels of lead (Pb), arsenic (As) (i.e., toxic elements), and neurodevelopmental indicators (i.e., motor and state regulation cluster score) measured by the Brazelton Neonatal Behavioral Assessment Scale, third edition (NBAS III) in this cohort at birth. Using additional follow-up, this study investigated the effects of cord blood levels of Pb, As, and zinc (Zn) (an essential element) and the postnatal environment on the neurodevelopment of 6-month-old infants in Chitwan Valley, Nepal.

METHODS: In total, 100 mother-infant pairs were recruited from Chitwan District, Nepal. Pb, As, and Zn concentrations in cord blood were measured. Postnatal raising environment (i.e., HOME score or home environment hereafter) was evaluated using the Home Observation for Measurement of Environment (HOME) scale. Neurodevelopment of infants at 6months (n=94) was assessed according to the Bayley Scale of Infant Development, second edition (BSID II). Multivariable regression adjusting for covariates was performed to determine the associations of in utero levels of toxic and essential elements and the home environment with neurodevelopment scores.

RESULTS: Cord blood levels of Pb, As, and Zn were not associated with any BSID II cluster scores in 6-month-old infants. The total HOME score was positively associated with the Psychomotor Development Index (PDI) score (coefficient=0.59, 95% confidence interval [CI]=0.04 to 1.13).

CONCLUSION: In this cohort, detrimental effects of in utero Pb and As on neurodevelopmental indicators observed at birth did not persist at 6months of age, while it showed an association between the neurodevelopment and home environment.

Parajuli, 2014, 2278945

Study evaluation

Epidemiological study populations