Uneven Ground: Spatial Analysis of Soil Lead Concentrations in an Urban School Garden Network (Brooklyn,NY)

Abstract

Background:

Soil lead (Pb) contamination remains a persistent yet underestimated health concern, particularly in urban school gardens where young people learn and play. Although much attention has been given to lead in paint and water, far less is known about soil lead and disparities in pollution within school soils.

Methods:

This study analyzed soil lead concentrations in 31 Brooklyn, NY public schools with active garden programs. Garden and adjacent school ground soil samples were analyzed using X-ray fluorescence. Spatial proximity to polluting sources was mapped using geostatistical analysis of 306 known environmental hazard sites. Demographic data, soil management surveys, and statistical models assessed associations between soil lead, pollution proximity, and school characteristics.

Results:

Of the soil samples, 42% exceeded the minimum Environmental Protection Agency’s screening level for child-accessible soils near known lead sources (100 ppm). Garden soils exhibited lower average lead concentrations than adjacent school grounds (74 mg/kg standard deviation (SD) 62 and 147 mg/kg SD 86, respectively), suggesting the implementation of effective lead mitigation practices, including using raised beds and imported soils; however, this implementation varied across schools. In addition, schools with higher proportions of Black, Hispanic/Latin American, or low-income students were found to be located closer to higher numbers of environmental hazard sites.

Discussion:

Historical pollution and structural inequalities intersect within urban school environments, replicating other known manifestations of spatial inequality. School gardens exhibit varying degrees of precautionary soil management, raising concerns about equitable implementation of soil safety practices in cities with complex pollution landscapes.

Conclusion:

Targeted support, sustained management and monitoring, and policy frameworks are needed to ensure that school gardens exist as safe and equitable sites for all students.