December 12th, 2017
Background: Lead-contaminated house dust is a major source of lead exposure for children in the U.S. In 1999-2004, the National Health and Nutrition Examination Survey (NHANES) collected dust lead loading (PbD) samples from the homes of children aged 12-60 months. Objectives: To compare national PbD levels with existing health-based standards and to identify housing and demographic factors associated with floor and window sill PbD. Methods: NHANES PbD data (n= 2,065 from floors and n=1,618 from window sills) and covariates were used to construct linear and logistic regression models. Results: The population weighted geometric mean floor and window sill PbD were 0.5 ?g/ft2 (GSE=1.0) and 7.6 ?g/ft2 (GSE=1.0), respectively. Only 0.16% of the floors and 4.0% of the sills had PbD at or above current Federal standards of 40 and 250 ?g/ft2, respectively. Income, race/ethnicity, floor surface/condition, window sill PbD, year of construction, recent renovation, smoking, and survey year were significant predictors of floor PbD (R2 = 35%).A similar set of predictors plus the presence of large areas of exterior deteriorated paint in pre-1950 homes and the presence of interior deteriorated paint explained 20% of the variability in sill PbD.A companion article describes the relationship between children’s blood lead and PbD. Conclusion: Most houses with children have PbD far below Federal standards. Factors associated with PbD in our population-based models are primarily the same as factors identified in smaller at-risk cohorts. PbD on floors and window sills should be kept as low as possible to protect children.