Long-term effect of dust control on blood lead concentrations

Background. Dust control is recommended to prevent children's exposure to r esidential lead hazards, but the long-term effect of dust control on childr en's exposure to environmental lead is unknown. Objective. To determine the effect of dust control on children's exposure t o lead, as measured by blood lead concentration at 48 months of age. Design. A randomized, controlled trial. Setting. Rochester, New York. Participants. A total of 275 urban children were randomized at 6 months of age; 189 (69%) were available for the 48-month follow-up blood test. Intervention. Children and their families were randomly assigned to an inte rvention group that received cleaning equipment and up to 8 visits by a tra ined lead hazard control advisor or to a control group. The intervention wa s terminated when the children were 24 months of age. Outcome Measures. Geometric mean blood lead concentration and prevalence of elevated blood lead concentration (ie, greater than or equal to 10 mu g/dL , greater than or equal to 15 mu g/dL, and greater than or equal to 20 mu g /dL), by group assignment. Results. For children with 48-month blood tests, baseline geometric mean bl ood lead concentrations were 2.8 mu g/dL (95% confidence interval [CI]: 2.6 ,3.0); there were no significant differences in baseline characteristics or lead exposure by group assignment. At 48 months of age, the geometric mean blood lead was 5.9 mu g/dL (95% CI: 5.3,6.7) for the intervention group an d 6.1 mu g/dL (95% CI: 5.5,6.9) for the control group. The percentage of ch ildren with a 48-month blood lead greater than or equal to 10 mu g/dL, grea ter than or equal to 15 mu g/dL, and greater than or equal to 20 mu g/dL wa s 19% versus 19%, 2% versus 9%, and 1% versus 2% in the intervention and co ntrol groups, respectively. Conclusions. We conclude that dust control, as performed by families and in the absence of lead hazard controls to reduce ongoing contamination from l ead-based paint, was not effective in preventing children's exposure to res idential lead hazards.