The effect of dust lead control on blood lead in toddlers: a randomized trial.

BACKGROUND Contaminated household dust is believed to be a major source of exposure for most children with elevated blood lead levels. To determine if a vigorous dust clean-up effort would reduce this exposure we conducted a randomized controlled field trial. METHODS We randomized 113 urban children between the ages of 6 and 36 months: 56 children to a lead dust intervention composed of maternal education and biweekly assistance with household cleaning and 57 children to a control group. Household cleaning was done by two trained lay workers who focused their efforts on wet mopping of floors, damp-sponging of walls and horizontal surfaces, and vacuuming with a high-efficiency particle accumulating vacuum. Household dust lead levels, child blood lead levels, and maternal knowledge of lead poisoning and sources of exposure were measured before and after the intervention. RESULTS Ninety-nine children were successfully followed for 12 +/- 3 months: 46 children in the lead group and 53 children in the control group. Age and blood lead were similar in the two groups at baseline and averaged 20 months and 12.0 micrograms/dL, respectively. Blood lead fell 17% in the intervention group and did not change among controls. Household dust and dust lead measures also fell significantly in the intervention group. Children in homes cleaned 20 or more times throughout the year had an average blood lead reduction of 34%. CONCLUSIONS Regular home cleaning, accompanied by maternal education, is a safe and partially effective intervention that should be recommended for the large majority of lead-exposed children for whom, unfortunately, removal to lead-safe housing is not an option.