Project Funders: U.S. Department of Housing and Urban Development (HUD)
Project Partners: Michigan Department of Health and Human Services
Project Contact: Jonathan Wilson, email@example.com, 443.539.4162
What we studied: NCHH conducted a cross-sectional observational study, utilizing data collected by the MDHHS’ lead poisoning prevention program to update a decades-old exposure pathway model for lead in children.
Why it matters: In the 1990s, studies (Lanphear et al., 1998; and Lanphear and Roghmann, 1997) identified lead paint and the contaminated dust and soil it generates as the principal sources and pathways of children’s exposure to lead hazards. The lack of up-to-date data characterizing lead exposure pathways for paint, dust, soil, and water and controlling for other key variables has limited the ability to understand if the importance of these sources has changed since the 1980s and 1990s.
What we found: Results showed that children’s blood lead level was directly predicted by lead in settled floor house dust, child’s age, season, and mouthing behavior. Blood lead was indirectly predicted by windowsill and trough dust lead, bare soil lead, proportion of floors with carpets, and exterior building condition. Paint lead was an indirect predictor of blood lead through the soil and dust pathways. Water lead levels and consumption did not emerge as significant predictors in this study. Results indicated that dust, soil, and paint lead levels are connected to each other, making it difficult to assign exposures to specific building components or surfaces.
Impact of study: Although risk factors for specific children remain highly variable and worthy of investigation to pinpoint individual exposures, this study suggests that the main direct and indirect exposure pathways for most children in older housing remain paint and the contaminated dust and soil it generates. Future analyses to optimize the number and types of samples and interview questions are worthy of investigation; for example, it does not appear that the more than 15 water samples collected in each home in this study and/or the consumption patterns helped to predict blood lead level, although other studies have shown lead-contaminated drinking water to be important. Although this study suggests that both dust lead and blood lead levels in high-risk homes have declined since the 1990s, because most homes in the nation still have not been assessed for lead hazards, too many children remain at needless risk.
MDHHS provided comprehensive biological, environmental, demographic, and other 2017-2021 data for 429 children in 345 homes. Data included lead in blood, paint, dust, soil, water, and other housing, demographic, and behavioral metrics. Fifty-three percent (53%) of the children had blood lead levels 5 µg/dL or higher. SAS and MPLUS statistical programs were used to conduct robust modeling and analyze exposure pathways.
Latest page update: September 3, 2022.