Primary prevention of childhood lead exposure: A randomized trial of dust control

Background. Dust control is recommended as one of the primary strategies to prevent or control children's exposure to residential lead hazards, but th e effect of dust control on children's blood lead levels is poorly understo od. Objective. To determine the effectiveness of dust control in preventing chi ldren's exposure to lead, as measured by blood lead levels, during their pe ak age of susceptibility. Design. A randomized, controlled trial. Setting. Rochester, NY. Participants. A total of 275 urban children were randomized at 6 months of age, of whom 246 (90%) were available for the 24-month-old follow-up visit. Interventions. Children and their families were randomly assigned to an int ervention group (n = 140), which received cleaning equipment and up to eigh t visits by a dust control advisor, or a control group (n = 135). Outcome Measures. Geometric mean blood lead levels and prevalence of elevat ed blood lead levels (ie, >10 mu g/dL, 15 mu g/dL, and 20 mu g/dL). Results. At baseline, children's geometric mean blood lead levels were 2.9 mu g/dL (95% confidence interval [CI] = 2.7, 3.1); there were no significan t differences in characteristics or lead exposure by group assignment, with the exception of water lead levels. For children in the intervention group , the mean number of visits by a dust control advisor during the 18-month s tudy period was 6.2; 51 (36%) had 4 to 7 visits, and 69 (49%) had 8 visits. At 23 months of age, the geometric mean blood lead was 7.3 mu g/dL (95% CI = 6.6, 8.2) for the intervention group and 7.8 mu g/dL (95% CI = 6.9, 8.7) for the control group. The percentage of children with a 24-month blood le ad 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 was 31%6 versus 36%, 12% versus 1 4%, and 5% versus 7% in the intervention and control 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, is not effective in the primary prevention of childhood le ad exposure.