Managing Global Resources for a Secure Future

Far from being static repositories of the urban lead inventory, soils represent a dynamic pool of lead that can be re-mobilized through anthropogenic activities, particularly with increasing interest for utilizing urban soils for food production. Understanding household-scale spatial and depth distributions of soil lead is critical for minimizing health risks from soil lead. Management recommendations and land-use siting strategies for urban soils at the scale of individual households are often based on total or extractable lead. However, increasing interest in utilizing in-vitro bioaccessibility assays to better understand health risks from soil lead requires a better understanding of the variability of lead bioaccessibility at the scale of individual properties. In this work, we investigate the spatial and depth trends of soil lead bioaccessibility (IVBA Pb) across 12 households in Minneapolis-St. Paul in conjunction with fine-scale trends in total lead through the in-situ use of portable X-Ray Fluoresence (pXRF) backed by laboratory wet chemical extraction. Spatial and depth patterns in IVBA Pb were related to variations in total Pb, extractable Pb, soil pH, organic matter, and phosphorus. Understanding these distributions and patterns is critical for making better risk-based recommendations for land use and siting decisions at the household scale.