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.