Mapping legacy lead: socioeconomic and demographic connections in urban soil contamination in Lafayette, LA

The objectives of this study aim to comprehensively map and analyze soil lead (Pb) contamination, understand its health and socioeconomic impacts, and track its temporal evolution in Lafayette, LA, thereby equipping the community with critical data to mitigate exposure and inform future urban planning and public health policies.

A total of 1,290 composite topsoil samples were collected from public areas (high traffic roadways, industrial zones, and parks) and residential regions (near foundations, street sides, open spaces, and gardens) across 24 census tracts in Lafayette, LA. Using X-ray Fluorescence (XRF) for quantification and geographic information system (GIS) - based Kriging interpolation for spatial analysis, the study integrated BLL data from the Louisiana Department of Health and demographic data from the U.S. Census Bureau to assess the relationship between Pb exposure and socioeconomic disparities.

The median soil Pb concentration was 27 mg/kg, which is below the median geochemical background of 33 mg/kg (3–52 mg/kg) measured in sediment samples from a small Louisiana drainage basin. The historic city center exhibited the highest soil Pb concentrations. Higher poverty levels and older housing are significant predictors of increased soil Pb contamination, with notable disparities showing higher soil Pb levels in Black-majority areas compared to White-majority areas, highlighting a potential environmental justice issue. Only four census tracts had children with BLLs between 5–10 μg/dL and none > 10 μg/dL, based on data from 2013–2017.

The findings underscore the disproportionate impact of soil Pb contamination on minority and socioeconomically disadvantaged communities within urban environments. This study highlights the need for targeted policy interventions and community engagement to address the identified disparities in Pb exposure and its associated health risks. The results indicate the need for enhanced urban soil management and remediation efforts, particularly in older, lower-income neighborhoods with a significant minority presence.