A Generalizable Evaluated Approach, Applying Advanced Geospatial Statistical Methods, to Identify High Lead Exposure Locations at Census Tract Scale: Michigan Case Study

Abstract

Background: Despite great progress in reducing environmental lead (Pb) levels, many children in the United States are still being exposed. Objective: Our aim was to develop a generalizable approach for systematically identifying, verifying, and analyzing locations with high prevalence of children’s elevated blood Pb levels (EBLLs) and to assess available Pb models/indices as surrogates, using a Michigan case study. Methods: We obtained BLL test results of children of age in Michigan from 2006–2016; we then evaluated them for data representativeness by comparing two percentage EBLL (%EBLL) rates (number of children tested with EBLL divided by both number of children tested and total population). We analyzed %EBLLs across census tracts over three time periods and between two EBLL reference values ( vs. ) to evaluate consistency. Locations with high %EBLLs were identified by a top 20 percentile method and a Getis-Ord Gi* geospatial cluster “hotspot” analysis. For the locations identified, we analyzed convergences with three available Pb exposure models/indices based on old housing and sociodemographics. Results: Analyses of 2014–2016 %EBLL data identified 11 Michigan locations via cluster analysis and 80 additional locations via the top 20 percentile method and their associated census tracts. Data representativeness and consistency were supported by a 0.93 correlation coefficient between the two EBLL rates over 11 y, and a Kappa score of of %EBLL hotspots across the time periods (2014–2016) and reference values. Many EBLL hotspot locations converge with current Pb exposure models/indices; others diverge, suggesting additional Pb sources for targeted interventions. Discussion: This analysis confirmed known Pb hotspot locations and revealed new ones at a finer geographic resolution than previously available, using advanced geospatial statistical methods and mapping/visualization. It also assessed the utility of surrogates in the absence of blood Pb data. This approach could be applied to other states to inform Pb mitigation and prevention efforts. https://doi.org/10.1289/EHP9705

Hyperlocal US PM2.5 Trace Elements Super-learned

“…The highest amounts of Pb were found in the East North Central states and Mid-Atlantic (Figure S36), which could be associated with metal industry and power plants (31,35), but also resuspension of particles deposited in previous decades from leaded gasoline, and exterior lead paint. Recently, a study in Michigan has identified Pb hotspots at census tracts (36). We additionally found Pb hotspots across the US populated urban areas, confirming motor vehicles and traffic as a source, as also reported by the Inhalation Particle Network (31).…”

Invited Perspective: Identifying Childhood Lead Exposure Hotspots for Action

“…Xue et al. 15 present “a systematic approach to help identify high lead exposure locations” using state-based childhood blood lead surveillance data collected over an 11-year period (2006–2016) by the Michigan Department of Health and Human Services (MDHHS). The authors identified census tracts where children were identified with elevated BLLs (EBLLs) of , , or .…”

“…Although there is still a lot of work to do, concerted use of evidence-based practices, primary prevention strategies, and approaches like those by Xue et al. 15 have every chance of turning the tide. We need to capitalize on the political will and current momentum at the federal, state, and local levels to finally eliminate sources of childhood lead exposure in the environment.…”

Childhood Lead Poisoning 1970-2022: Charting Progress and Needed Reforms

“…32 New models using complex algorithms and mapping are useful for focusing attention on disparities in risk for exposure. 33 However, given substantial evidence of widespread exposure, targeting interventions solely to identified “hot spots” will leave many children at risk.…”

“…Another 2018 study showed that housing remains a core problem with deteriorating lead-based paint and lead dust as the main contributing environmental factor in about 90% of all childhood lead poisoning 32. New models using complex algorithms and mapping are useful for focusing attention on disparities in risk for exposure 33. However, given substantial evidence of widespread exposure, targeting interventions solely to identified “hot spots” will leave many children at risk.…”