Legacy contamination in Chicago urban park soils: Spatial patterns, socioeconomic disparities, and implications for urban agriculture
Jenkins E. M., Heafner H., Montgomery J., Soumano V., Paltseva A. A.
iScience
Urban Farm DB summary
Portable X-ray fluorescence measurement of seven trace elements in 233 topsoil samples from five Chicago parks. Lead, arsenic, copper, zinc and chromium exceeded Illinois background levels in 89–100% of samples; arsenic exceeded EPA screening levels in 94% of samples and lead in 7%. Contamination was higher at parks farther from the city centre — Douglass and Humboldt parks, in predominantly minority, lower-income neighbourhoods — than at Cottontail, Grant and Webster. Principal-component analysis identified an anthropogenic signature (PC1, 51.7%) driven by Pb, Zn, Cu and As and a geogenic signature (PC2, 17.0%) associated with Mn and Ni. Areas of Douglass and Humboldt parks were classified as not safe for gardening in native soil; Webster as safe with minor restrictions. The authors conclude that park-soil contamination follows socioeconomic gradients, reflecting environmental injustice and a need for targeted remediation.