Community-engaged analysis of soil lead contamination near a historical metallurgy facility in Los Angeles, California

Legacy industrial lead (Pb) contamination poses a public health problem worldwide. In Southeast Los Angeles, California, a history of concentrated industrial activity has raised concern about Pb contamination in the area's neighborhoods, particularly in Huntington Park. One former industrial facility in Huntington Park has attracted attention from both a local community environmental justice organization and the U.S. Environmental Protection Agency (USEPA). Although a 2023 report by the USEPA concluded that the Pb contamination from this site was "not significant," the 2024 reduction of the federal soil screening level for residential soil Pb-from 400 mg/kg to 200 mg/kg-prompted a reassessment. In a community-based participatory research effort,91 residential surface soil samples from Huntington Park were analyzed by XRF spectrometry and compared with 118 surface soil samples from broader Los Angeles. In Huntington Park, 85.7% and 57.2% of soils exceeded the state (80 mg/kg) and new federal (200 mg/kg) screening levels, respectively-compared to 55.9% and 19.6% citywide. Soil Pb concentration was found to be statistically significantly higher in the residential soils in Huntington Park compared to the rest of Greater Los Angeles (Mann-Whitney U, p < 0.01). Soil Pb concentrations in Huntington Park also correlated significantly with proximity to the industrial site. Notably, 49.5% of Huntington Park soils fell between the updated and the former federal screening level, highlighting the need for reevaluation of the area's contamination. These results also emphasize the need for remedial action to be taken in areas like Huntington Park, which serves as a clear example of disproportionate contaminant exposure faced by disadvantaged/minority communities.