Community prevalence survey of children's blood lead levels and environmental lead contamination in inner Sydney

Objective: To determine the distribution of blood lead levels in preschool children in inner Sydney and identify possible sources of environmental lead. Design: Cross sectional community based prevalence survey of children and the houses in which they live, and a survey of volunteer children. Setting: Mort Bay and Summer Hill, residential localities in inner Sydney. Participants: Ninety-five children aged 9-48 months able to be identified in a defined geographic area and 63 children aged 9-48 months volunteered by their parents. Outcome measures: Concentrations of lead in venous blood of all children and in samples from the home environment of Mort Bay children. Results: Four of the children (2.5%) had blood lead levels ≥ 1.21 μmol/L (25 μg/dL, the current Australian threshold of concern), 27 (17.1%) had levels ≥ 0.72 μmol/L (15 μg/dL, the new US threshold for individual intervention) and 80 (50.6%) had levels ≥ 0.48 μmol/L (10 μg/dL, the new US threshold for community intervention). Blood lead concentrations were significantly correlated with concentrations of lead in 'sink' soil (r = 0.555, P = 0.026), play area soil (r = 0.492, P = 0.016) and dust from vacuum cleaners (r = 0.428, P = 0.05), and with age of child (r = -0.182, P = 0.023). The presence of the child during house renovation was a strong predictor of having a blood lead level above 0.72 μmol/L (15 μg/dL)(odds ratio, 4.6; 95% confidence interval, 1.8 - 11.7, P = 0.001). Conclusions: Lead in soil and in household dust in older areas of Sydney is likely to represent a significant health hazard to young children. Many thousands of children may be affected in Sydney and other Australian cities. There is an urgent need for expanded prevalence surveys, public education and the development of strategies for the abatement of lead in urban environments.