Superfund Research Program
UNM Metals Exposure and Toxicity Assessment on tribal Lands in the Southwest (METALS) Superfund Research Program
Center Director: Johnnye L. Lewis
Grant Number: P42ES025589
Funding Period: 2022-2027
The University of New Mexico (UNM) Metal Exposure and Toxicity Assessment on Tribal Lands of the Southwest Superfund Research Program (SRP) Center (METALS) focuses on more than 500 abandoned uranium mines (AUMs) on Navajo Nation and the Jackpile Mine on Laguna Pueblo, a legacy of the Cold War now being assessed under the Comprehensive Environmental Response, Compensation, and Liability Act. They represent more than 4,500 AUMs in the 15 Western U.S. that are home to more than half of the Indigenous population. During the inaugural phase of METALS, the team worked in close partnership with Indigenous partners to determine that since mining began in the 1940s, weathering of metal mixtures in the millions of tons of waste has produced nanoparticles of varying mineralogy. While these nanoparticles have implications for both mobility and toxicity of the waste, they are not considered in prioritization or cleanup due to significant data gaps. The researcher’s health studies have shown that exposures to these metal mixtures increase the prevalence of hypertension, multiple chronic diseases, and immune dysfunction, and autoantibody production. While about 25% of the population shows no evidence of exposures, biomonitoring confirms an equivalent percentage shows exposure to clusters of up to 12 metals at significantly higher concentrations than the rest of the U.S. population.
The METALS community-partnered approach and strong team integration inclusive of community partners has allowed the design of clinical interventions that are scientifically sound and respectful of culture, of which there are high rates of participation and compliance. Phase 2 of METALS builds on their strong community partnerships to drive research by the needs of partners, and uses single-atom, state-of-the science transmission electron microscopy to both answer community questions about agricultural safety as impacted by particulate redistribution, and to understand the processes of resuspension, environmental mobility, and plant uptake at a mechanistic scale to inform risk reduction. The confirmation of multiple routes of exposures and evidence of metals-induced inflammation and oxidative stress lead the team to examine contributions of ingestion and inhalation within community exposures. These studies explore the potential for high-dose exposures to immune regulatory cells in lung and gut to alter systemic immune function, informing design of more targeted intervention. Their recognition of the role of plant/fungi symbiosis in transformation of environmental metal mixtures has led to their collaborations with the national Sevilleta Long Term Ecological Research program in New Mexico in development and testing of fungal bioreactors based in the balance of native fungal communities and their interactions with geochemical variables as a remediation strategy. These remediation approaches provide a novel strategy to overcome the ineffectiveness of bacterial bioreactors in a toxic environment and produce sustainable, cost-effective solutions to protect key resources of cultural importance. The team is building on their strong partnerships to generate common dialogue with communities, researchers, clinicians, and tribal and federal policy makers informed by their solution-oriented team science to inform risk reduction at community, clinical, and policy levels.