Exposure of U.S. children to residential dust lead, 1999-2004: II. The contribution of lead-contaminated dust to children's blood lead levels.

Background: The U.S. Centers for Disease Control and Prevention collected health, housing, and environmental data in a single integrated national survey for the first time in the United States in 1999-2004. Objectives: We aimed to determine how floor dust lead (PbD) loadings and other housing factors influence childhood blood lead (PbB) levels and lead poisoning. Methods: We analyzed data from the 1999DS2004 National Health and Nutrition Examination Survey (NHANES) , including 2,155 children 12-60 months of age with PbB and PbD measurements. We used linear and logistic regression models to predict log-transformed PbB and the odds that PbB was > 5 and > 10 µg/dL at a range of floor PbD. Results: The population-weighted geometric mean (GM) PbB was 2.0 µg/dL (geometric standard error = 1.0) . Age of child, race/ethnicity, serum cotinine concentration, poverty-to-income ratio, country of birth, year of building construction, floor PbD by floor surface and condition, windowsill PbD, presence of deteriorated paint, home-apartment type, smoking in the home, and recent renovation were significant predictors in either the linear model [the proportion of variability in the dependent variable accounted for by the model (R²) = 40%] or logistic model for 10 µg/dL (R² = 5%) . At floor PbD = 12 µg/ft², the models predict that 4.6% of children living in homes constructed before 1978 have PbB > 10 µg/dL, 27% have PbB > 5 µg/dL, and the GM PbB is 3.9 µg/dL. Conclusions: Lowering the floor PbD standard below the current standard of 40 µg/ft² would protect more children from elevated PbB. [ABSTRACT FROM AUTHOR]