Maternal Manganese During Pregnancy And Neurodevelopment In Young Children From The Infants' Environmental Health (ISA) Study

摘要

Background: Numerous cross-sectional studies of preschool-age children have observed that exposure to manganese (Mn) adversely affects neurodevelopment. However, few prospective studies have looked at the behavioral effects of maternal Mn concentrations during pregnancy in young children. Methods: We conducted a birth cohort study (Infants' Environmental Health Study, ISA) among families living near banana plantations aerially sprayed with Mn-containing fungicide mancozeb in Costa Rica. We measured Mn concentrations in maternal blood and hair samples collected at different times during pregnancy. We assessed behavioral problems in 242 children at 5 years of age (range = 4.6-6.5) using the Child Behavior Checklist (CBCL). We tested for linear and nonlinear relationships and assessed effect modification by child sex. Models were adjusted for maternal education, parity, gestational age, child sex, and child age and HOME score at five years. Results: Median (P25-P75) maternal blood and hair Mn averaged during pregnancy were 23.9 μg/L (20.2-28.5) and 1.9 μg/g (1.0-4.2), respectively. We did not find linear associations of maternal blood and hair Mn with any of the CBCL behavioral outcomes. However, we observed nonlinear associations of maternal blood Mn and internalizing problems [β for the middle tertile = 2.9 (95% Cl: -0.5, 6.2) and for the upper fertile = 2.0 (-1.5, 5.4), compared to the lower tertile] among girls. We also found nonlinear associations of maternal blood Mn with anxiety/depression symptoms [β for the middle tertile = 1.1 (0.0, 2.3), compared to the lower tertile] and somatic complaints [β for the middle tertile = -1.2 (-2.2, -0.1)] among boys. Conclusions: Further studies, which include maternal and cord blood concentrations, as well as other elements, such as iron, are needed to understand whether maternal excess Mn during pregnancy is associated with behavioral outcomes in young children.