Assessing the Effectiveness of Soil Abatement in Reducing Risks of Childhood Lead Exposure. A. H. Marcus and R. Elias, National Center for Environmental Assessment, U.S. EPA, Research Triangle Park, NC 27711
Childhood lead exposure is still a significant pediatric health problem in the U.S., with much of the high-risk exposure derived from historic residues of lead in soil, dust, and paint. The Urban Soil Lead Abatement Demonstration project (USLADP) was designed to evaluate the effectiveness of soil abatement in reducing the contribution of leaded soil to blood lead concentrations and other lead exposure indices in inner-city children in Baltimore, Boston, and Cincinnati. U.S. EPA carried out an integrated assessment of the USLADP that extended the analyses of the individual study teams. Each project team used somewhat different abatement strategies. The Boston study found a reduction of about 1.8 ug/dl (15 percent) in the first year of the study, and a larger effect in the second year in the group that received both interior dust abatement in Phase 1 and soil abatement in Phase 2. The Baltimore study found little effect of soil abatement, and the Cincinnati study found some differences between study groups, although the largest and most significant differences appeared to occur between two control groups. The conditions under which soil abatement appears to be effective include: (1) large persistent reduction of lead in soil and household dust; (2) prevention of dust recontamination by interior paint or by nonremediated exterior sources; (3) indication that residential soil lead is a significant source of childhood exposure. The USLADP only evaluated children currently living in remediated housing; larger benefits may occur in preventing exposure in future residents.