The University of Arizona Superfund Research Center Returns to the College of Pharmacy with a Focus on Addressing Toxic Mine-Dust Exposure
As the University of Arizona Superfund Research Center (UA SRC) begins its thirty-sixth year, it returns to the stewardship of the R. Ken Coit College of Pharmacy, under the leadership of Xinxin Ding, PhD, department head of Pharmacology and Toxicology. With the recent renewal of this grant, the center received $15M over the next five years to continue addressing the unique human health risks encountered in the US Southwest, where distinct geological and climatic attributes affect human health and its exposure to a variety of toxicants, especially arsenic.
Ding is the third College of Pharmacy director to head the center, beginning his tenure in 2022. His own background in pharmacology and toxicology underscores his role, as his laboratory studies how drugs and environmental pollutants damage various organs and cause cancer and other diseases. In his lab, Ding’s main research objectives are to identify factors that predispose individuals to chemical toxicity and develop novel approaches for disease prevention.
“Our current research focus on mining waste exposure, health impacts, and mitigation is timely, given the critical demand for metals and metalloids essential to modern technology,” says Ding. “We have built a highly enthusiastic and collaborative team of about 20 key investigators across five University of Arizona colleges. We are also pivoting to study the complex interactions between chemical contaminants and fungal pathogens in mine tailings dust as risk factors for lung diseases. I have high hopes for what our extraordinary team can accomplish in the next five years in protecting AZ communities from exposures to hazardous dust and their adverse health effects and assisting the mining industry to develop cleaner and safer approaches to mining waste management.”
The UA SRC has two biomedical science projects, two environmental science and engineering projects, plus four cores focusing on administrative, community engagement, training, and data management. This includes twenty faculty investigators from throughout the University of Arizona at the College of Pharmacy, College of Medicine, Mel and Enid Zuckerman College of Public Health, College of Science, and the College of Agriculture, Life, and Environmental Sciences (CALES).
August marked the start of the 2025-2030 funding cycle, administered through the National Institute of Environmental Health Sciences (NIEHS). This cycle’s submission, “The DUST Center: Hazardous Dust in Drylands – Exposure, Health Impacts, and Mitigation”, addresses the unique human health risks arising from exposure to dusts containing toxic metal(loid)s and fungal spores in the US Southwest, an area with a rich history and future of mining. Here, disadvantaged mining communities experience chronic inhalation exposure to hazardous dusts and Native American communities in particular exhibit increased susceptibility to nonmalignant, inflammatory lung diseases.
In 2021, the death rate for chronic lower respiratory diseases was the sixth leading cause of death in the U.S. and the fifth leading cause of death in Arizona. Chronic Obstructive Pulmonary Disease (COPD) affects over 16.6 million Americans, and the incidence is higher in Native American communities in Arizona and Indigenous individuals in the U.S. Populations residing near mining sites, including these Indigenous communities, exhibit increased susceptibility to lung diseases. Exposures to metals in particulate matter, such as zinc, cadmium, and chromium, have been linked to allergies and asthma, while serum lead levels were associated with reduced lung function, a sign of serious forms of asthmatic lung disease. Population data linking mine tailings particulate matter exposure and other lung diseases are incomplete, indicating an urgent and growing need to evaluate the role of inhalation dust exposures in the development of these lung diseases.
The work starts by constructing a mechanistic model, which the researchers can use to help predict exposures and associated health outcomes, help to inform public health prevention in communities neighboring mine waste sites and design remediation-based interventions for exposure. And since mining is a major economic driver for Arizona, it is essential to understand its environmental and human health impacts to facilitate its continued pursuit throughout the state and region. The intensified global competition for mineral resources requires access to critical elements from mining, and their goal is to ensure that this is enabled while minimizing negative environmental and human health impacts.
At the Beginning
Authorized by Congress in 1980, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) was passed to address the human and environmental dangers of abandoned or uncontrolled hazardous waste disposal. The Superfund Amendments and Reauthorization Act (SARA) of 1986 created the Superfund Research Program at the National Institute of Environmental Health Sciences (NIEHS) in 1987. Since the beginning, the NIH Superfund Research Program has grown from an annual budget of $3 million to fund four university-based research centers to just over an annual budget of $50 million to fund more than twenty research centers, plus individual research projects, small business research projects, occupational and safety training education programs, and time-sensitive research grants.
Since its inception in 1989, the UA SRC has received more than $100 million from NIH and leveraged this valuable resource to address a variety of environmental health issues faced by communities in Arizona and elsewhere, ranging from birth defects and cancer associated with trichloroethylene (TCE) exposure to diabetes and lung diseases associated with exposures to arsenic-containing mining waste. UA SRC contributed hundreds of publications toward not only fundamental research on how environmental contaminants cause diseases, but also the development of technologies to detect and clean up the toxic chemicals. UA SRC also led the nation in its community engagement and research translation efforts to bolster the public’s awareness of potential health risks and set safety standards for exposure levels for various contaminants, such as arsenic and TCE.
The University of Arizona Superfund Research Center
It was at the College of Pharmacy that the UA Superfund originated, with Dean Carter, PhD, serving as its first director from 1990 to 2000. The UA Superfund grew from a core of medical, toxicological, and environmental scientists to ultimately include faculty and researchers from five colleges and thirteen departments. This was one of the first multidisciplinary grants at the University of Arizona. A. Jay Gandolfi, PhD, was another College of Pharmacy faculty member who directed the UA Superfund, from 2000 to 2012. During his tenure, the NIEHS emphasized the need for translational research to better inform the public and to provide better interactions with federal regulators and legislators.
“As Director of the UA Superfund, I was able to appreciate the talent and expertise of faculty and researchers outside the scope of my field of toxicology,” says Gandolfi. “I was able to help mesh researchers with different skills to focus on a common environmental pollutant problem. The NIEHS Superfund required translational efforts to inform and involve the public and interact with federal regulators. This required the addition of public health investigators who translated our basic research results to the appropriate audiences. This was a whole new undertaking for many of the UA Superfund investigators.”
Over the years, the UA Superfund has advanced environmental protection by:
- Helping set federal standards for pollutant exposure
- Supporting at-risk populations
- Partnering with industry
- Developing effective remediation processes
- Working closely with state and federal regulators
- Training neighborhood health personnel
- Educating hundreds of students to address real-world environmental problems
It was during her tenure from 2012 to 2022 as director of the UA Superfund that Raina Maier, PhD (CALES), expanded and enhanced the use of environmental studies to assess exposure to pollutants, resulting in the development of the Center for Environmental Sustainability and collaborative interactions with international mining companies. Maier, Environmental Science professor, now serves as associate center director and lead investigator of Project 4, “Phytoremediation of Metal-Contaminated Mine Sites in Drylands”. This project develops transformative science to understand and mitigate soil metal contamination and particulate emission from mining waste.
The goal of her team of investigators (including Alicja Babst-Kostecka, PhD, Flurin Babst, PhD, and Willem van Leeuwen, PhD) is to understand and mitigate soil metal contamination and particulate emission in degraded dryland regions, with a focus on mine tailings sites, through phytoremediation. Phytoremediation uses plants for the revegetation and stabilization of contaminants.
Their goal is to identify plants and plant growth strategies to optimize phytoremediation of mine tailings in arid environments and to develop new drone-based technology to assess plant performance under conditions of metal stress across mine sites in the U.S. Southwest. These efforts will be conducted in collaboration with mining industry partners, enabling field testing of both promising plant candidates and advanced drone monitoring systems.
The research will begin with ground-based surveys of plants at metal-contaminated sites to examine how plant ecotypes and their associated soil microbiomes influence metal uptake behavior in plants, ranging from exclusion to hyperaccumulation. Plants that show promise as either metal excluders or hyperaccumulators will undergo further testing in the field for their ability to establish and grow on mine tailings.
“One unique aspect of this research,” shares Maier, “is that we propose to develop optical (hyperspectral) and Light Detection and Ranging (LiDAR) imaging that are deployable with drone technology to rapidly assess both vegetative cover and metal contamination. If successful, this novel combination of hyperspectral and LiDAR imaging will allow mapping of key characteristics of vegetation across entire mine sites, including plant cover, species composition, biomass, and metal and stress status.” If successful, the technology will offer a cost-effective approach for evaluating and mapping site conditions, enabling more efficient planning, prioritization, and implementation of remediation efforts across large, impacted areas.
Project 3, “Transformation of Metal(loid)-bearing Particulate Matter and Associated Impacts on Bioaccessibility,” is led by Jon Chorover, PhD, professor in Environmental Science and associate dean for Research in the College of Agriculture, Life and Environmental Sciences.
He and his team, including Monica Ramirez-Andreotta, PhD, and Robert Root, PhD (CALES), are investigating the chemical and mineralogical composition of particulate matter derived from various mine tailings sites in the western U.S. and assessing the bioaccessibility in lung fluid of toxic metals and metalloids in these particles, with a particular focus on arsenic, lead, cadmium and zinc.
Their research hypothesizes that the properties of chemistry, mineralogy, and lung bioaccessibility will vary across different sites due to variation in the weathering environments and exposure. Anticipating that these properties will vary systematically with particle size, they are developing a predictive understanding of these variations.
In addition to working with tailings particles themselves, which contribute to dust deposition in nearby communities, they will also work with particles derived from wildfires in ecosystems proximal to mine tailing sites. To the extent that vegetation and organic components of such ecosystems are impacted by mining-derived contaminants, wildfires and associated combustion of organic matter in these ecosystems may produce distinct inhalable particulate matter that contains elevated levels of toxic metal(loid)s that are also of concern to community health.
As part of the investigation into chemical composition, they will probe the local bonding environment of these toxic metals and metalloids, known as the molecular speciation of the contaminants. Researchers hypothesize that contaminant molecular speciation controls bioaccessibility and that an improved predictive understanding of human health risk from these particles requires a molecular-level understanding of their composition.
The UA SRC is a uniquely powerful means to study health impacts associated with mining waste exposure because it brings together environmental and biomedical scientists in a large-scale research collaboration. Such collaborations are essential to risk assessment because accurately assessing human health risk requires characterizing both exposure and dose-response. Whereas the former is the focus of Project 3 and also, to some extent, of Project 4, and typically the domain of environmental scientists, the latter is the focus of Project 1 and Project 2, and typically the domain of biomedical scientists. UA SRC Projects 1 and 2 are led by College of Pharmacy investigators, Ding, Yin Chen, PhD, and Qing-Yu Zhang, PhD. The team also includes Julie Ledford, PhD, of College of Medicine Tucson.
The College of Pharmacy’s research shows that mine waste and contaminated dust, often containing arsenic and other metal(loids), can damage the lungs in ways that make people more vulnerable to everyday environmental threats. Arsenic, and likely other metal(loids) as well, weakens the natural cleaning and protective system of the airways. This system, called mucociliary clearance, acts like the body’s filter, sweeping out dust, germs, and mold spores. When arsenic disrupts this system, it reduces key protective proteins and makes the lung barrier leaky and less effective.
Project 1, “Effects of Arsenic and Arsenic-containing Mine Tailings Dusts on Airway Epithelium and Susceptibility to Mold Exposure,” led by Chen, focuses on why the effects of arsenic exposure matter. Once the barrier is compromised, people become more susceptible to common environmental exposures, especially mold. Mold spores are everywhere in our environment, and while healthy lungs can usually clear them out, weakened lungs cannot. In fact, their studies suggest that arsenic exposure could make the lungs much more sensitive to mold, creating a combined risk greater than either exposure alone.
This research aims to understand how exposure to arsenic and arsenic-containing mine dust harms the lungs, especially in ways that may trigger certain inflammatory lung diseases that have not been well studied before. By identifying the biological changes arsenic causes in the lungs, the research will help pinpoint early warning signs of exposure and guide the development of treatments to reduce lung damage. Overall, these findings will improve the understanding of the real-world health risks faced by those living near contaminated Superfund sites and support better protection and prevention efforts.
This is especially important in Arizona, where Valley Fever, a serious fungal infection caused by soil-dwelling mold, is already a major health concern. Another example is Alternaria, a mold that can trigger allergies and asthma, which is also abundant in Arizona. The combination of contaminated dust and fungal exposure creates a double burden for our communities.
The Superfund enables researchers to dig deeper into these problems and examine how dust damages the lungs and how it increases vulnerability to mold exposure. Their research group has built a strong reputation in creating innovative models in fungal disease research. This new superfund project builds on that strength, tying together their ongoing work with three other NIH-funded grants that all focus on mold and lung health.
Focusing on how breathing in arsenic-containing dust affects lung health is Project 2, “Induction of Fibrotic Lung Injury by Inhalation Exposure to Arsenic and Arsenic-Containing Mine Tailings,” co-led by Ding and Zhang. Those living near mining areas can be exposed to arsenic by breathing in contaminated dust or consuming polluted water or food. When mine dust is inhaled, toxic metals can enter the lungs directly, where they may cause harm before the body can filter them out.
The goal is to determine how much of these toxic metals reach lung tissue, how long they remain there, and how they contribute to lung damage. The study also examines whether combined exposure to arsenic and mold spores worsens lung injury.
Using arsenic-related lung scarring as a model, the research will test whether inhaled arsenic-containing dust can cause lung damage and identify which forms of arsenic and other metals are most harmful. They intend to improve risk detection and help develop better strategies to prevent disease in communities near contaminated sites.
The impact of the UA SRC goes far beyond the four research projects. Its Research Experience and Training Coordination Core (RETCC), co-led by Maier and Ramirez-Andreotta, equips the next generation of transdisciplinary scientists to tackle complex hazardous-waste and environmental health challenges. The Data Management and Analysis Core (DMAC), led by College of Pharmacy’s Bernardo Lemos, PhD, and joined by UA computational science experts Nirav Merchant and Tyson Swetnam, aims to equip the UA SRC with state-of-the-art tools to enable data sharing, analyses, and hypothesis testing. The UA SRC Community Engagement Core (CEC), led by Joseph Hoover, PhD, and joined by colleague Karletta Chief, PhD, of CALES, and College of Public Health researchers Stephanie Carroll, PhD, and Chris Lim, PhD, seeks to empower communities confronting environmental health threats from legacy and active hardrock mining sites, to foster impactful collaborations between Center investigators and community partners in identifying and mitigating human exposures to dust from mine waste and material.
Finally, the research translation efforts of UA SRC, led by Ramirez-Andreotta, ensure that research results are effectively translated to communities, the public, NIEHS, and diverse collaborator groups that span and intersect environmental public health, science, and engineering.
Moving Forward
By bringing these efforts together, the Superfund is in a unique position to provide clear answers about the risks, develop strategies to protect health, and give communities the information they need to make informed decisions. Ultimately, this research is about turning cutting-edge science into practical solutions that safeguard families living near contaminated sites.
Ding looks forward to continuing the Center's legacy during his tenure. “I am very excited and humbled to serve as the fourth director of the UA SRC,” says Ding. “I will make sure that UA SRC will continue to serve as a role model for collaborative and translational research at UA and beyond, and I am looking forward to being a part of many exciting research advancements to come out of the superfund program that will effectively address some of the pressing environmental health science concerns posed by mining activities in the Southwest and other arid regions.”