Current pediatric and maternal lead levels in blood and breast milk in andean inhabitants of a lead-glazing enclave

Prenatal and postnatal lead (Pb) exposure may induce neurodevelopmental disabilities in children. As part of an ongoing health-monitoring study, blood lead (PbB) levels were compared in 90 children tested in 2003 (current group) and 166 children tested between 1996 and 2000 (reference group) in Ecuadorian Andean villages with high Pb contamination. The mean PbB level for children in the reference group was 40 μg/dL (range, 6.2-119.1), and significantly higher than the mean PbB level of 25.5 μg/dL (range, 2.1-94.3) for the current group (t test, P = 0.0001). An analysis of variance revealed no significant main effects for age and gender and no significant interaction between age and gender for the current group but a significant age by gender interaction for the reference group (F = 5.96, P = 0.01). Regression analysis revealed a significant correlation (r = 0.258, P = 0.01) between PbB level and age for males but not for females in the reference group. The Pb levels in breast milk from nursing mothers ranged from 0.4-20.5 μg/L (mean, 4.6), and the PbB levels in the breastfeeding mothers ranged from 4.5-35.2 μg/dL (mean, 17.1). The PbB levels of mother-infant pairs ranged from 4.6-27.4 μg/dL for mothers and 3.9-33.5 μg/dL for infants. The results showed significantly reduced PbB levels in children in the study area and suggest that a Pb education and prevention program contributed to the current reduction in Pb intoxication.