Association between lead in umbilical cord blood and neurodevelopment at 6 months of age - PIPA Project / Rio de Janeiro / Brazil.

Abstract

Background/Aim: Environmental exposure to heavy metals in urban areas has been associated with adverse effects on child health. To investigate the effects of environmental pollutants on maternal-child health and to test viability for a birth cohort study, a pilot study (PIPA pilot study) was conducted from October 2017 to August 2018, at the Maternity School of the Federal University of Rio de Janeiro, Brazil. This study aims evaluate the association between lead concentration in umbilical cord blood and neurodevelopment at 6 months of age. Methods: Lead concentrations in umbilical cord blood were measured by inductively coupled plasma mass spectrometry (ICP-MS), in 117 umbilical cord blood. Infant’s neurodevelopment was evaluated using Denver Developmental Screening Test II (DDST-II) at six months old (n=41). It was analyzed the association between the proportion of failures identified in the DDST-II at the sixth month of age and the concentration of lead in umbilical cord blood divided into tertiles, the first tertile being the reference value. Results: The proportion of failures in DDST-II was 31.7% at six months of age. It was observed for the 2º tertile RR = 0.593 p <0.595 (CI: 0.188-1.872) and for the 3º tertile RR = 0.735, p <0.999 (CI: 0.199-2.714). At one month old (n=54) and three months old (n=54), the failure performed respectively 18.5 % and 24.1 %. Conclusion: There is an increase in the proportion of failures according to the age at which the assessment was made, although not statistically significant. The small number of newborns evaluated can justify these results. More follow-up studies with a higher number of children are needed to better assess the relationship between lead levels and neurodevelopment.