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 1999-2004 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 >or=5 and >or=10 microg/dL at a range of floor PbD.

Results: The population-weighted geometric mean (GM) PbB was 2.0 microg/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 microg/dL (R2=5%). At floor PbD=12 microg/ft2, the models predict that 4.6% of children living in homes constructed before 1978 have PbB>or=10 microg/dL, 27% have PbB>or=5 microg/dL, and the GM PbB is 3.9 microg/dL.

Conclusions: Lowering the floor PbD standard below the current standard of 40 microg/ft2 would protect more children from elevated PbB.