Inventory of Soil Heavy Metal Concentrations in Lafayette, Louisiana Using X-ray Fluorescence Analysis

The hypothesis of this study is that soil lead (Pb) contamination in urban areas of Lafayette, LA, is significantly influenced by socioeconomic factors and historical land use. The study aims to comprehensively map and analyze soil contamination, understand its socioeconomic impacts. The ultimate goal is to equip the community with critical data to mitigate heavy metal exposure and inform future urban planning and public health policies.

Key Findings:
- Soil Pb Concentrations: The median soil Pb concentration across all samples was 27 mg/kg, below the median geochemical background of 33 mg/kg measured in sediment samples from a small Louisiana drainage basin. However, significant variability was observed, with concentrations ranging from <8 to 6877 mg/kg.
- Spatial Distribution: The highest soil Pb concentrations were found in the historic city center, with census tracts 1, 22, 8, and 9 exhibiting the highest median concentrations. These areas have a higher prevalence of older housing, which is a significant predictor of increased soil Pb contamination.
- Public Areas vs. Residential Areas: Residential areas, particularly near house foundations and street sides, showed higher Pb concentrations compared to public parks and open spaces. This highlights the influence of historical use of lead-based paints and proximity to traffic emissions.

The study's findings can be used to:
- Inform Urban Planning: Data on Pb hotspots can guide urban planners in prioritizing soil remediation.
- Public Health Policies: Health departments can use this data to focus on high-risk areas for lead exposure and implement community health interventions.
- Community Engagement: By sharing these results with the community, awareness can be raised about soil contamination risks and the importance of soil testing and remediation.

This study provides critical insights into the distribution of heavy metals in urban settings, emphasizing the need for preventative measures and targeted interventions to mitigate exposure risks. The comprehensive mapping and analysis of soil contamination in Lafayette, LA, serve as a model for addressing similar issues in other urban areas, contributing to the broader understanding of environmental justice and public health.