Environmental Health Catalyst: Visualizing Soil Contamination and Bioavailability of Metal(Loid)S for Action with Communities

Abstract

Mining poses ecological and human health risks. The state of Arizona has naturally occurring metal(loid)s that can be concentrated and transported during mining activities. These activities can increase human exposure to the mined and processed metal(loid)s. Exposure to metal(loid)s such as arsenic (As), lead (Pb), manganese (Mn), and copper (Cu) are associated with cancer and noncancer outcomes. This work outlines a co-created community science process with the rural town of Superior, AZ, where the community is subject to potential environmental hazards from legacy, active, and proposed extraction activities. Gardenroots, a co-created community science environmental health project started in Superior, AZ in 2018. Community scientists and university researchers determined metal(loid) concentrations in drinking water, soil, and dust. After extensive data sharing efforts, participants began to question past remediation efforts and pose new research questions, e.g.: (1) What sites were remediated?; (2) What determined a site’s eligibility for remediation?; and (3) How can we protect families that are unknowingly moving into homes that may have contaminated soil?. Thus, to answer the community questions, Gardenroots efforts evolved and responded by: (a) maintaining community engagement, (b) identifying and consolidating past monitoring and remediation efforts in the area, (c) creating an interactive soil map that visualized As, Pb, Mn, and Cu concentrations in soil; and (c) determining site-specific Pb and As gastric bioavailability. The soil visualizations include soil data from pre- (126 property values) and post-smelter (17 property values) demolition. To determine the bioaccessible fraction (BAF) of Pb and As, In-Vitro Bioaccessibility Assays EPA Method 1340 was conducted using the Gardenroots residential soils. Our assay calculations indicate bioaccessible fraction for As (12%-53%) and Pb (3%-79%). To provide additional soil sampling and prompt further soil remediation efforts, we worked with local, state, and federal agencies to organize and hosted a Center for Disease Control – Agency for Toxic Substances and Disease Registry soilSHOP on June 4, 2022. At this soilSHOP, we provided soil screening and health education to the Superior, AZ region. Based on community reporting and media tracking, Gardenroots and the soilSHOP prompted further action by Broken Hill Proprietary (BHP) Copper, to continue with their Voluntary Remediation Program (VRP) being overseen by the Arizona Department of Environmental Quality. The VRP is designed to provide environmental monitoring and remediation in town. It is anticipated that the recent actions taken by BHP Copper and Resolution Copper are a result of the co-created community science and soilSHOP, both of which are designed to reduce information disparities and increase environmental health literacy.