Blood lead concentrations in children: new ranges.

Background: Lead exposure in young children may have adverse neurodevelopmental effects. Currently, an increased blood lead concentration is defined as >or=10 microg/dl for males and females of all ages, including children younger than 6 years. Using a large hospital population (n=11145), we define more specific ranges for pediatric blood lead concentrations.

Methods: Pediatric blood lead concentrations were determined (atomic absorption spectrophotometry) on patient samples accrued from January 2001 to June 2002, and the data was analyzed employing the Hoffman approach.

Results: For lead, the 2.5th and 97.5th percentiles for subjects aged 0 to 12 months were 2.3 to 4.7 microg/dl for females and 1.8 to 4.9 microg/dl for males. The 97.5th percentiles increased for the 1-2 years age group both for females (5.2 microg/dl) and males (5.6 microg/dl). There was a significant decrease in blood lead concentrations after age 10 years, the 97.5th percentile being 4.4 microg/dl in both female and male subjects. The values in all corresponding age groups were similar for females and for males. The medians of all age groups were similar for females and for male subjects.

Conclusion: The blood lead concentrations are much lower compared to previously published data.