Interventions designed to reduce residential lead exposure in children and pregnant women at 32 weeks’ gestation are effective for decreasing blood lead concentrations, according to a study published in JAMA Pediatrics.
A total of 355 pregnant women who attended prenatal care clinics in Cincinnati, Ohio, were recruited. Investigators randomly assigned women to either a comprehensive residential lead exposure reduction intervention (n=174) or a control group (n=181).
The intervention group was composed of various lead reduction strategies, including the installation of a tap water filter in cases where lead in drinking water was greater than 2 μg/L, the use of groundcover to cover bare lead-contaminated soil, repairing and/or repainting of deteriorated or peeled lead-based paint, installation of window trough liners, creation of smooth floors and windows, replacement of windows with lead-based paint with more than 10% deterioration, and the maintenance of a clean and dust-free environment. Researchers measured residential dust lead loadings at baseline and in women and their children at age 1 year and again at age 2 years. In addition, children’s blood lead concentrations and behavior, cognition, and executive functions were assessed at 1, 2, 3, 4, 5, and 8 years of age.
Interventions resulted in significant reductions in dust lead loadings on windowsills (−40% [95% CI, −60% to −11%]), the floor (−24% [95% CI, −43% to 1%]), and the window trough (−47% [95% CI, −68% to −10%]). No significant effect of the interventions was found for reducing blood lead concentrations in children from 1 to 8 years of age (−6% [95% CI, −17% to 6%]; P =.29). Less parent-reported anxiety was reported in children who were in the intervention vs the control group (β, −1.6 [95% CI, −3.2 to −0.1]; P =.04). The lead reduction interventions were more effective among non-Hispanic white children (difference: 4.2 [95% CI, 0.2-8.2]) for their effect on verbal IQ scores compared with non-Hispanic black children (difference: −6.8 [95% CI, −14 to 0.3]; intervention × race/ethnicity P <.01).
A limitation of the analysis included the lack of intervention implementation in children with substantially high residential lead exposure, which prevented the generalizability of these findings across this specific subset of the population.
The researchers noted that their findings provide both “clinicians and public health practitioners with an opportunity to prevent childhood lead exposure and is directly relevant to a recent court order mandating the US Environmental Protection Agency to promulgate a lower residential dust lead standard.”
Braun JM, Hornung R, Chen A, et al. Effect of residential lead-hazard interventions on childhood blood lead concentrations and neurobehavioral outcomes: a randomized clinical trial. JAMA Pediatr. 2018;172:934-942.