In Situ Exploration of Soil Lead in Residential Communities Using X-Ray Fluorescence and Geospatial Visualization

Lead contamination in soil is a human health hazard common in residential communities that pre-date regulatory bans on lead in both gasoline and paints. New remote sensing tools allow for quicker and more affordable sampling, but there is still a challenge in interpreting the data, visualizing the results, and communicating the relevance for response and remediation. Our work builds on previous studies analyzing soil lead concentrations at West Point, NY. The federal installation and college campus hosts residential neighborhoods with historic homes that were painted with lead paint in the past and are adjacent to high traffic roadways. Previous research established several areas where the lead concentrations significantly exceeded the U.S. Environmental Protection Agency (EPA) recommended safe concentrations for soil, but further exploration was necessary to refine those results. We targeted one location where a 2019 measurement indicated lead in excess of 1200 mg/kg. We used an X-Ray Fluorescence (XRF) meter to collect 73 soil lead concentrations between the road and the home, logging the locations using ArcGIS Collector. Results indicate localized lead concentrations with distinctive patterns that may provide clues to the origin of the contamination. Our analysis suggests that in situ measurements are effective to characterize concentrations but conclusions on the severity of lead contamination should not be made using widely spaced transect investigations. The XRF, combined with geospatial visualization methods, is a quick and inexpensive way to investigate neighborhood-scale soil lead contamination and refine the potential remediation response.