Low-level lead exposure and cognitive development in early childhood

The authors studied toddlers with low-level lead exposure to determine whet her adverse developmental effects were evident. The study sample consisted of a cohort of 68 children aged 12 to 36 months who had blood lead levels t ower than 25 mu g/dL on a routine screening in a targe urban public hospita l clinic. Children with blood lead levels between 10 and 24.9 mu g/dL had a mean Mental Developmental Index (Bayley Scales of infant Development, Seco nd Edition) score that was 6.3 points lower than that of children with bloo d lead levels between 0 and 9.9 mu g/dL (95% confidence interval: 0.6, 11.9 ). After adjusting for confounders, the difference was 6.2 points (95% conf idence interval: 1.7, 10.8). Pediatricians and public health entities shoul d continue in their efforts to reduce the lead burden through environmental control and ongoing surveillance.