Effect of Residential Lead-Hazard Interventions on Childhood Blood Lead Concentrations and Neurobehavioral Outcomes

Abstract

IMPORTANCE Childhood lead exposure is associated with neurobehavioral deficits. The effect of a residential lead hazard intervention on blood lead concentrations and neurobehavioral development remains unknown. OBJECTIVE To determine whether a comprehensive residential lead-exposure reduction intervention completed during pregnancy could decrease residential dust lead loadings, prevent elevated blood lead concentrations, and improve childhood neurobehavioral outcomes. DESIGN, SETTING, AND PARTICIPANTS This longitudinal, community-based randomized clinical trial of pregnant women and their children, the Health Outcomes and Measures of the Environment (HOME) Study, was conducted between March 1, 2003, and January 31, 2006. Pregnant women attending 1 of 9 prenatal care clinics affiliated with 3 hospitals in the Cincinnati, Ohio, metropolitan area were recruited. Of the 1263 eligible women, 468 (37.0%) agreed to participate and 355 women (75.8%) were randomized in this intention-to-treat analysis. Participants were randomly assigned to receive 1 of 2 interventions designed to reduce residential lead or injury hazards. Follow-up on children took place at 1, 2, 3, 4, 5, and 8 years of age. Data analysis was performed from September 2, 2017, to May 6, 2018. MAIN OUTCOMES AND MEASURES Residential dust lead loadings were measured at baseline and when children were 1 and 2 years of age. At 1, 2, 3, 4, 5, and 8 years of age, the children's blood lead concentrations as well as behavior, cognition, and executive functions were assessed. RESULTS Of the 355 women randomized, 174 (49.0%) were assigned to the intervention group (mean [SD] age at delivery, 30.1 (5.5) years; 119 [68.3%] self-identified as non-Hispanic white) and 181 (50.9%) to the control group (mean [SD] age at delivery, 29.2 [5.7] years; 123 [67.9%] self-identified as non-Hispanic white). The intervention reduced the dust lead loadings for the floor (24%; 95% CI,-43% to 1%), windowsill (40%; 95% CI,-60% to-11%), and window trough (47%; 95% CI,-68% to-10%) surfaces. The intervention did not statistically significantly reduce childhood blood lead concentrations (-6%; 95% CI,-17% to 6%; P = .29). Neurobehavioral test scores were not statistically different between children in the intervention group than those in the control group except for a reduction in anxiety scores in the intervention group (β =-1.6; 95% CI,-3.2 to-0.1; P = .04). CONCLUSIONS AND RELEVANCE Residential lead exposures, as well as blood lead concentrations in non-Hispanic black children, were reduced through a comprehensive lead-hazard intervention without elevating the lead body burden. However, this decrease did not result in substantive neurobehavioral improvements in children. TRIAL REGISTRATION ClinicalTrials.gov identifier: NCT00129324

Validation of a Machine Learning Model to Predict Childhood Lead Poisoning

“…Regarding the intervention, a Cochrane review found that “dust control interventions may lead to little or no difference in blood lead levels” but that “the quality of evidence was moderate to low, meaning that future research is likely to change these results.” 26 (p2) More recently, results of a randomized clinical trial in Cincinnati, Ohio, were reported. 27 Overall, a comprehensive residential intervention did not result in significant BLL reductions or neurobehavioral improvements, albeit in a population with relatively low BLLs (>5 μg/dL in 3% of control group). Significant BLL reductions were, however, documented among the higher-risk non-Hispanic Black subpopulation (>5 μg/dL in 6% of control group), and the authors concluded that the “intervention may be more effective among high-risk populations.” 27 (p941) Our findings show that a machine learning prediction model can identify such a high-risk subpopulation (BLL ≥ 6μg/dL in 16% of the 5% at highest risk).…”

Lead screening update from the US Preventive Services Task Force

“…4 For example, a randomized controlled trial found that among non-Hispanic black children, blood lead concentrations were 31% lower (95% CI, À50% to À5%; P = .02) in the intervention group than the control group. 5 The Task Force failed to include this and dozens of other studies showing significant reductions in blood and dust lead levels following screening and hazard control, including a large-scale study of 14 jurisdictions and nearly 3000 housing units. 6 Historically, clinicians have appropriately ignored the Task Force's previous recommendations in this area because their review is viewed as flawed and incomplete.…”

Does Involving Parents in Soil Sampling Identify Causes of Child Exposure to Lead? A Case Study of Community Engagement in Mining‐Impacted Towns in Peru

“…There is considerable scope for testing the effectiveness of a more participatory approach, because educational interventions have been shown to reduce child BLL but are not always effective (Hilts et al, 1998). Reducing indoor dust-Pb loading, has also been connected to decreases in child BLL, especially at higher BLLs (Braun et al, 2018;Haynes et al, 2002), although it appears there are diminishing returns at lower BLL (Braun et al, 2018;Haynes et al, 2002). Reducing indoor dust-Pb loading, has also been connected to decreases in child BLL, especially at higher BLLs (Braun et al, 2018;Haynes et al, 2002), although it appears there are diminishing returns at lower BLL (Braun et al, 2018;Haynes et al, 2002).…”

“…Covering, or replacing, high-Pb soil with clean soil has also been shown to reduce child BLLs (Laidlaw et al, 2017;Lanphear et al, 2003;von Lindern et al, 2003). Reducing indoor dust-Pb loading, has also been connected to decreases in child BLL, especially at higher BLLs (Braun et al, 2018;Haynes et al, 2002), although it appears there are diminishing returns at lower BLL (Braun et al, 2018;Haynes et al, 2002).…”