Do US Ambient Air Lead Levels Have a Significant Impact on Childhood Blood Lead Levels: Results of a National Study

Introduction. Although lead paint and leaded gasoline have not been used in the US for thirty years, thousands of US children continue to have blood lead levels (BLLs) of concern. Methods. We investigated the potential association of modeled air lead levels and BLLs >= 10 mu g/dL using a large CDC database with BLLs on children aged 0-3 years. Percent of children with BLLs >= 10 mu g/dL (2000-2007) by county and proportion of pre-50 housing and SES variables were merged with the US EPA's National Air Toxics Assessment (NATA) modeled air lead data. Results. The proportion with BLL >= 10 mu g/dL was 1.24% in the highest air lead counties, and the proportion with BLL >= 10 mu g/dL was 0.36% in the lowest air lead counties, resulting in a crude prevalence ratio of 3.4. Further analysis using multivariate negative binomial regression revealed that NATA lead was a significant predictor of % BLL >= 10 mu g/dL after controlling for percent pre-l950 housing, percent rural, and percent black. A geospatial regression revealed that air lead, percent older housing, and poverty were all significant predictors of % BLL >= 10 mu g/dL. Conclusions. More emphasis should be given to potential sources of ambient air lead near residential areas.