Digital Commons Network^™

Thermodynamics Of Binding Between Adeno-Associated Viruses And Heparin In Bulk And At Interfaces Via Isothermal Titration Calorimetry, Elizabeth Adeogun, Jude C. Obijiaku, Ronny Horax, Kayla E. Daugherty, Joshua Sakon, Xianghong Qian, Barbara Knutson, Stephen E. Rankin, Karthik Nayani

Chemical and Materials Engineering Faculty Publications

Adeno-associated viruses (AAVs) have emerged as promising vectors for gene therapy due to their non-pathogenic nature and ability to transduce various cell types efficiently. In recent years, there has been an increasing effort to optimize the production and purification of AAV to support clinical applications; however, challenges exist in affinity ligand design, synthesis, and characterization. Understanding the binding interactions of these viruses with functional molecules is pivotal for the development of affinity-based separation methods of AAVs. Classical methods to measure thermodynamic parameters such as Isothermal Titration Calorimetry (ITC) are challenging to employ in these scenarios, as the concentrations of the …

Provider And Patient Perspectives On The Diagnosis And Treatment Of Alzheimer's Disease, Philippe Amouyel, Sandrine Andrieu, Angela Bradshaw, Ralph C. Carmona, Magali Dumont, Lea Tenenholz Grinberg, Takeshi Iwatsubo, Oskar Hansson, Clifford R. Jack, Gregory A. Jicha, Simin Mahinrad, Eric Mcdade, Catherine J. Mummery, Ronald C. Petersen, Shelagh Robinson, Julie A. Schneider, Lenny Shellcross, Amanda G. Smith, Heather M. Snyder, Beth Tapply, Charlotte Teunissen, Wiesje M. Van Der Flier, Bruno Vellas, David Wallon, Jeff D. Williamson, Donna Wilcock, Maria C. Carrillo

Neurology Faculty Publications

Since 2016, the Alzheimer's Association and the Fondation Alzheimer have hosted Global Alzheimer's Leadership Series (GoALS) global think tanks, with world-leading experts for innovative discussions to advance Alzheimer's disease (AD) research and care. The second GoALS think tank, held in June 2024 in Paris, focused on the relationship between biological changes and clinical manifestations of AD in the context of the evolving therapeutic landscape. Discussions spanned real-world experiences of providers, patients, and their families, theoretical considerations, and health system challenges. The lived experience perspective was central to these discussions. The importance of shared decision-making, clear and transparent communication, and the …

Soybean Plant Population Density Recommendations Across The United States, Giovani Preza Fontes, Carrie Ortel, Emma Macham, David Moseley, Shawn Conley, Chad Lee, Mark A. Licht, Laura E. Lindsey, Haleigh J. Ortmeier-Clarke, Rachel Vann, Maninder P. Singh, Seth Naeve, Jeremy Ross, Jake Mcneal, Michael Plumblee, Shaun Casteel, Eros Francisco, Michael J. Mulvaney, Nicolas Cafaro La Menza, Andre Froes De Borja Reis, Daniela Carrijo, Emerson Nafziger

Plant and Soil Sciences Faculty Publications

Rising production costs and declining commodity prices have compelled farmers to reassess their input and management strategies. Soybean [Glycine max (L.) Merr] seed costs, in particular, have continued to increase due to advances in biotechnology, higher-yielding germplasm, and available seed treatments, accounting for 32–35% of the total operational expenses in current soybean production systems. Optimizing seeding rate is therefore one area of consideration for improving profitability and maximizing return on investment. However, soybean yield response to plant population density is influenced by the combination of several factors, including water availability, temperature, radiation interception, planting practices, and crop growth and development. …

School Renewal And School Well-Being, Jianping Shen, John Lane, Patricia Reeves, Siche Feng, Xin Ma

Educational, School, and Counseling Psychology Faculty Publications

In this longitudinal case study, we examined school well-being during the change process. We operationalized the change process as the school renewal model and viewed school well-being from the perspective of the PERMA (positive emotion, engagement, relationships, meaning, and accomplishment) model. We found that all elements of the PERMA model were manifested in the school renewal process and that the school renewal process was not dominated solely by conflict and tension, as the literature typically suggests about the change process. The findings of the study suggest the possibility of reframing tension as productive rather than detrimental in the school renewal …

Alterations Of Cerebral Extracellular Vesicle Microrna Profiling Potentially Disrupts Brain Homeostasis Following Myocardial Infarction, Md Monowarul Islam, Shouyi Liang, Lijun Sun, Guoku Hu, Neha Dhyani, Lie Gao, Tara L. Rudebush, Xue Xu, Jinpeng Liu, Irving H. Zucker, Changhai Tian

Markey Cancer Center Faculty Publications

Cognitive impairment (CI) is prevalent among heart failure (HF) patients. Although the brain injury in HF is multifactorial, oxidative stress and neuroinflammation are common pathological features of neurological disorders and are increasingly recognized as key mechanisms underlying CI. Extracellular vesicles (EVs) are well-established mediators of biological signaling in myocardial function and are widely recognized for transporting a variety of microRNAs. However, whether myocardial injury alters the miRNA profiles of brain EVs, potentially contributing to cognitive impairment (CI) by disrupting brain homeostasis, remains poorly understood. Using a rodent myocardial infarction (MI) model, we isolated brain EVs and characterized their miRNA profiling …

Chemical Structure Representation Standardization Is Needed To Generalize Metabolite-Pathway Involvement Prediction Across Kegg, Reactome, And Metacyc Knowledgebases, Erik D. Huckvale, Hunter N.B. Moseley

Markey Cancer Center Faculty Publications

Background/Objectives: Due to the utility of knowing the pathway involvement of metabolites detected in biological experiments, knowledgebases such as the Kyoto Encyclopedia of Genes and Genomes (KEGG), Reactome, and MetaCyc have annotated compound entries to specific pathways defined by the knowledgebase. However, these compound-pathway annotations are largely incomplete and are costly to obtain experimentally or curate from published scientific literature. This metabolite-pathway annotation incompleteness problem is amenable to machine learning (ML)-based solutions. But to date, no machine learning model has been trained on all three knowledgebases to maximize its performance and robustness. This may be due to inconsistencies in chemical …

Collections Of Western Wheatgrass And Blue Grama And Associated Nematode Genera In The Western Dakotas, R E. Barker, J D. Berdahl, J M. Krupinsky, E T. Jacobson

IGC Proceedings (1977-2023)

Western wheatgrass (Agropyron smithii Rydb.) and blue grama (Bouteloua gracilis[Willd. ex H.B.K.J Lag. ex Griffiths) are widely distributed throughout the U.S.A. They arc two of the predominant native grasses in rangelands in the northern Great Plains. Because suitable cultivars are not always available for reseeding disturbed areas, we collected plants of the two species and evaluated phenotypic variability to determine potential for breeding improvement. We also sampled the nematode popula­tion associated with the collections. Sampling sites were systematically chosen by establishing a grid pattern 19 .3 km apart in the western halves of North Dakota and South Dakota. …

Adaptation And Utilization Of Three Legume In China, Huang Wenhui

IGC Proceedings (1977-2023)

China is a vast territory with extremely varied climates, soil, and topography, and it is very rich in pasture grass resources. The main legumes for forage are Alfalfa (Medicago sativa L.), yellow alfalfa (Medicago folcata L.) and shadawang (Astragalis adsurgent Pall.)

An Ice-Sheet Modelling Framework To Determine Vulnerable Regions Of The Greenland Ice Sheet In The Past, Benjamin A. Keisling, Joerg M. Schaefer, Robert M. Deconto, Jason P. Briner, Nicolás E. Young, Caleb K. Walcott-George, Gisela Winckler, Allie Balter-Kennedy, Sridhar Anandakrishnan

Earth and Environmental Sciences Faculty Publications

The contribution of the Greenland Ice Sheet (GrIS) to sea-level rise is accelerating and there is an urgent need to characterize which sectors of the ice sheet are the most vulnerable. Estimating the volume of Greenland ice that was lost during past warm periods can support efforts to constrain the ice sheet's response to future warming. Sub-ice sediment and bedrock, retrieved from deep ice core campaigns or targeted drilling efforts, yield critical and direct information about past ice-free conditions. However, it is challenging to scale the few available sub-ice point measurements to the geometry of the entire ice sheet. Here, …

A Mixed Methods Examination Of Organizational Approaches To Fentanyl Test Strip Distribution And Training Across Multiple States, Kitty H. Gelberg, Megan E. Hall, Janet E. Childerhose, Mary R. Russo, Fernando Montero, Kaleigh Niles, Jill Oliveri, Haley Ramsey Harden, Rachel A. Vickers-Smith, Arnie Aldridge, Sarah G. Stenger, Katherine R. Marks, Louisa Gilbert, Sharon L. Walsh, Nabila El-Bassel, Carter Roeber, Redonna Chandler

Epidemiology and Environmental Health Faculty Publications

Background: Fentanyl test strips (FTS) have become a critical harm reduction tool, allowing people who use drugs (PWUD) to detect fentanyl in their drug supply and make informed decisions about their drug use. While FTS distribution is increasingly common, there is limited understanding of distribution strategies used by community organizations, and the education and training provided around FTS use. Given the proliferation of fentanyl in the drug supply, and the diverse motivations of PWUD, research is needed to better understand FTS distribution and training practices. This study examines FTS distribution strategies, training approaches, and the facilitators and barriers faced by …

Postapproval Study For Brain-Responsive Neurostimulation For Drug-Resistant Focal Epilepsy, Dawn Eliashiv, Vikram R. Rao, Barbara C. Jobst, Jerzy P. Szaflarski, John D. Rolston, Lesley C. Kaye, Taneeta Mindy Ganguly, Katie Bullinger, Patricia C. Dugan, David E. Burdette, Angela Y. Peters, Atif Sheikh, Kevin F. Haas, Dileep R. Nair, Lilit Mnatsakanyan, Imran H. Quraishi, Meriem K. Bensalem-Owen, Michael J. Doherty, Babak Razavi, Tiffany L. Fisher, Christopher Skidmore, Pradeep N. Modur, Tawnya M. Constantino, Vicenta Salanova, Andrew J. Cole, Olga Taraschenko, Angelica Rivera-Cruz, James W. Wheless, Nitin Tandon, Antoaneta Balabanov, Sami Aboumatar

Neurology Faculty Publications

BACKGROUND AND OBJECTIVES: Neuromodulation therapies are approved for the treatment of focal epilepsy based on data from randomized controlled trials (RCTs). After approval of a responsive direct brain stimulation device (The RNS System for focal epilepsy), the Food and Drug Administration required a prospective study to evaluate whether real-world safety and effectiveness differed from outcomes in the RCT. METHODS: This open-labeled study enrolled adult participants who met the RNS System-approved indication for use. The primary effectiveness end point was median percent change in seizure frequency at 3 years of treatment. Interim safety is presented; the primary safety endpoint analysis will …

Elevated Plasma Cholesterol Improves Sepsis Outcome By Promoting Hepatic Metabolic Reprogramming, Qian Wang, Jianyao Xue, Ling Guo, Dan Hao, Misa Ito, Rianna Reese, Bin Huang, Congqing Wu, Xiang An Li

Markey Cancer Center Faculty Publications

Background – Sepsis is a life-threatening condition with high mortality and limited therapeutic options. This study investigated the association between plasma cholesterol levels and sepsis survival and explored the mechanisms by which elevated cholesterol confers protection. Methods – We analyzed 2, 787 sepsis patients from the MIMIC-IV database, comparing cholesterol levels between 28-day survivors and non-survivors and assessing mortality risk using multivariable Cox regression. To test causality, C57BL/6J mice were fed either a high-cholesterol diet (HCD) or a regular diet (RD) before cecal ligation and puncture (CLP). Results – Survivors had significantly higher cholesterol than non-survivors (median 135 vs. 126 …

Maternal Opioid Use And Hepatitis C Infection Disrupt The Placental Immune Landscape And Structure, Heather E. True, Brianna M. Doratt, Sheridan B. Wagner, Delphine C. Malherbe, Nathan R. Shelman, Mahdi Eskandarian Boroujeni, Cynthia Cockerham, John M. O'Brien, Ilhem Messaoudi

Markey Cancer Center Faculty Publications

Maternal opioid use disorder (OUD) poses substantial risks to maternal and fetal health. These adverse outcomes are believed to be mediated, in part, by changes in placental structure and function; however, few studies have addressed this question. Here, we utilized flow cytometry, histology, and spatial and single-cell transcriptomics to uncover the impact of OUD on placental tissues. Given that half of individuals with chronic OUD contract hepatitis C (HCV), we further stratified our findings by maternal HCV status. Our results indicate that OUD leads to higher incidence of vascular malperfusion accompanied by increased levels of inflammatory markers and dysregulated secretion …

Monitored Natural Attenuation Evaluation And Additional Characterization Of A Ccr Unit Lithium Groundwater Plume, Matt Barickman, Adam Piestrzeniewicz Pg

World of Coal Ash Proceedings

Monitored Natural Attenuation (MNA) refers to the reliance on natural attenuation processes (within the context of a carefully controlled and monitored site cleanup approach) to meet groundwater protection standards (GPS) for a CCR unit within a reasonable time frame (USEPA, 1999). MNA is being evaluated as an adaptive management strategy for a CCR unit groundwater plume with statistically significant lithium concentrations above GPS, though with little risk of offsite migration. A previous MNA evaluation was performed for the lithium plume following the United States Environmental Protection Agency (USEPA) “tiered lines of evidence approach” (USEPA, 2015), which determined that there were …

Application Of Mine Tailings Flow Failure Assessment On Ccr, Zachary Fallert

World of Coal Ash Proceedings

A new geotechnical stability analysis method has been implemented for a CCR surface impoundment to aid in design for temporary cut slopes and final closure grades. Conditions have come to light after significant tailings dam failures occurred across the globe, specifically those exhibiting flow failures (i.e. failures in which tailings behave a liquid and flow out of the facility). These failures have come under intense scrutiny as the failures pose significant risk to public safety and the environment and have been observed in CCR. Additionally, static liquefaction has arisen as another potential but less well understood causative mechanism. As the …

Illinois Coal Ash Impoundment Assessment, Randy Locke

World of Coal Ash Proceedings

Coal combustion residuals (CCR) present one of the most significant waste management challenges in the United States. Illinois hosts 72 coal ash impoundments at 23 facilities across 22 counties. In 2019, the state enacted Public Act 101 0171 (Coal Ash Pollution Prevention Act), followed by Illinois Administrative Code Title 35, Part 845, establishing CCR surface impoundment standards. Even with federal and state requirements, significant gaps remain in identifying management options and site-specific risks. Key limitations include: (1) incomplete understanding of ash composition and variability within and among impoundments; and (2) fragmented information on impoundment physical properties, operational status, and geological …

Constructed Care: Stitching Patient Journeys Through Quilting And Healthcare Design, Ashley D. Moberly

Graduate Final Projects

This thesis investigates how healthcare environments can better support patient experience through improved wayfinding, spatial clarity, and human-centered design strategies. Contemporary healthcare systems are often complex and difficult to navigate, placing additional cognitive and emotional burdens on patients, particularly those traveling from rural and underserved regions. Drawing from both professional experience in healthcare facilities planning and a comprehensive review of literature on spatial perception, wayfinding, and patient-centered care, this research identifies key challenges in how patients' access, interpret, and move through healthcare environments.

In response, the study introduces the Quilt Logic System, a conceptual framework that translates principles derived from …

From Demolition To Digital: Using Virtual Reality To Interpret Hamilton House, Hannah R. Miller

Graduate Final Projects

This master’s project investigates the potential of digital reconstruction as a tool for documenting and interpreting demolished historic resources, using Hamilton House as a case study. Employing a mixed-methods approach, the research integrates archival analysis with digital modeling to recreate the spatial context of the house. By grounding the digital model in historical evidence, this study examines how virtual reconstruction can be used to interpret social relationships, patterns of use, and lived experiences that are not fully captured through traditional means of documentation. This project also considers the interpretive implications of reconstructing using fragmentary historical data, addressing the possibilities and …

A Novel Geospatial Tool For Assessing Risks And Opportunities For Conversion Of Ccr Closures Into Productive Solar Energy Generation Sites, Marc Theisen

World of Coal Ash Proceedings

Closure of Coal Combustion Residuals (CCR) surface impoundments and landfills offers unique opportunities for conversion to solar power sites with the potential to offset costs of post-closure care via generation of clean electricity. In 2023 the US Environmental Protection Agency (EPA) collaborated with the National Renewable Energy Laboratory (NREL) to create a report entitled “Coal Ash Disposal Sites and Opportunities for Solar Photovoltaic Development” (EPA Publication #540-S-23-004). The purpose of this document was to identify closed CCR units and provide key factors for their potential for solar photovoltaic (PV) development. In 2022, the EPA’s RE-Powering Initiative identified 772 current CCR …

Future Strategies For Beneficial Use Harvesting, Gabe Lang, Patrick Kiser

World of Coal Ash Proceedings

TVA is the largest public power company in the U.S. and has historically operated a fleet of 12 coal-fired plants as part of their diverse generating portfolio. To date, eight of the coal plants have been retired and the remaining four plants are projected to shut down in the next couple of decades. The decommissioning of these plants is driving a transition to harvesting of ponded and landfilled CCR’s to continue to support ready-mix concrete and other industries that enable infrastructure development. However, the regional market demand limits the ability to initiate widespread harvesting activities during near-term CCR Unit closure …

Engineered Turf And Solar Renewable Performance On Ccr In Extreme Weather, Tate Niekamp, Bryan Scholl, Ming Zhu, Thomas Orzech

World of Coal Ash Proceedings

The engineered turf final closure system, ClosureTurf®, is installed on a 309-acre coal combustion residual (CCR) unit at the TVA Shawnee Fossil Plant in West Paducah, KY. Approximately 100 megawatts of the PowerCap® solar photovoltaic (PV) system is currently being deployed directly atop the engineered turf cover. An overview of the ClosureTurf® and PowerCap® systems are presented along with a comparison to traditional soil covers and conventional utility-scale solar arrays. From August 2023 through July 2025, onsite and local weather data stations reported over 20 storm events including severe thunderstorms, tornado outbreaks, winter storm systems, atmospheric rivers, and post-tropical cyclones. …

Ccr Impoundment Closure: Encapsulation Design Using Closure Cap And Cutoff Wall, John Klamut, A. Edward Sciulli, Kevin Bortz

World of Coal Ash Proceedings

When closing a CCR Impoundment while leaving CCR in place, 40 CFR 257.102 requires minimizing post-closure infiltration of liquid into the CCR. This presentation will provide a description of a closure plan for a 16-acre impoundment in Indiana to accomplish this criteria. Key components of the closure plan which will be presented including consolidation of CCR into a smaller footprint due to questionable underlying clay layer identified in a portion of the impoundment and the design of a geosynthetic and soil cap system. A Soil-Cement-Bentonite (SCB) cutoff wall will be constructed to enclose the portion of the impoundment where CCR …

Narrative Power: Strengthening Coal Ash Communications In A Shifting Policy And Media Environment, Tamara Hinton

World of Coal Ash Proceedings

As coal ash management and beneficial use practices continue to advance and regulatory frameworks evolve, the industry still faces a persistent challenge: sharing its story clearly, credibly, and proactively to audiences beyond engineers and regulators. Public perception, media narratives, and stakeholder understanding increasingly influence policy decisions, project timelines, and market opportunities. This session focuses on how strategic communications can serve as a critical tool to support responsible coal ash management and beneficial use. This presentation explores how utilities and industry partners can move from reactive communications to a more deliberate, strategic approach that strengthens trust, mitigates risk, and reinforces the …

Integrated Groundwater Flow And Transport Modeling For Coal Combustion Residual (Ccr) Sites: From Closure Permitting To Corrective Action, Brian Hennings, Pejman Rasouli, Vic Modeer, Rhys Fuller

World of Coal Ash Proceedings

This session describes a coordinated multi-year effort to assess and manage groundwater quality at five CCR impoundments. The objectives were to (i) develop site-specific hydrogeologic and geochemical conceptual models; (ii) quantify groundwater flow and constituent transport under baseline and post-closure conditions; and (iii) design and evaluate corrective action strategies that achieve regulatory compliance and provide a defensible framework for long-term monitoring and management. The program highlights a phased approach aligned with regulatory requirements, progressing from closure construction to corrective action planning for detected exceedances. Comprehensive hydrogeologic datasets including borehole lithology, hydraulic testing, CCR source water characterization, and groundwater monitoring were …

Unlocking Data Integrity: How Historical Data Review Enhances The Accuracy Of Laboratory Results, Danielle Coles

World of Coal Ash Proceedings

Due to the implementation of the CCR rule and longstanding state regulatory guidelines, many utilities have built robust historical data sets associated with their groundwater monitoring programs. Data collected through these monitoring programs are used for many purposes including generation of statistics and site evaluation along with reporting to regulators and the public. Often, trends in data are evaluated long after data reporting to look at large scale trends or movement of constituents in the groundwater across a CCR landfill or entire site, but historical data sets can be used in real time to help determine the accuracy of current …

Anthropogenic Lithologic Characterization Through Use Of Advanced Visual Tools As A Means Of Identifying Coal Ash, Stephen Papageorge, Lucas Mangold

World of Coal Ash Proceedings

Identification and differentiation of particular Anthropocene strata such as coal ash and historic fill intermixed with native unconsolidated overburden presents significant challenges. To make specific determinations about origin and composition, a variety of tools are available such as our well-defined lithologic characterization processes. However, additional tools are required, as important and defining characteristic evidence isn’t available or obvious to our senses in the field. One challenge is the absence of surficial evidence of ash areas. Secondly, we are faced with limited access, as the responsible party no longer owns the site, there is new construction in the area of historic …

Mass Spectrometry-Based Spatial Imaging Of The Cochlea, Roberto A. Ribas, Qun Tang, Scarlett I. Caffee, Cameron J. Shedlock, Tara R. Hawkinson, Abigail K. Dragich, Borhane E.C. Ziani, Franca Bucco Paolasso, Alyson P. Black, Xin Ma, Harshitha C. Kota, Li Chen, Gregory I. Frolenkov, Derek B. Allison, Matthew S. Gentry, Ramon C. Sun, Craig W. Vander Kooi

Physiology Faculty Publications

Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI-MSI) is transforming spatial molecular studies. However, applying MALDI-MSI to small, anatomically complex tissues remains challenging. One such structure is the cochlea, the auditory part of the inner ear that is critical for hearing. To address these challenges, we developed and implemented a streamlined workflow for sample preparation and processing to obtain MALDI-MSI data on mouse cochlea. Sample acquisition was optimized to minimize time and processing steps, allowing use of flash-frozen neonatal mouse heads. This workflow enabled high spatial resolution metabolomic and lipidomic imaging of the sagittally cryosectioned mouse cochlea using N-(1-naphthyl) ethylenediamine dihydrochloride …

State Permitting Program Update, Jessica Reiss

World of Coal Ash Proceedings

State Permitting Program Update Jessica L. Reiss, Barnes & Thornburg LLP, 11 South Meridian Street, Indianapolis, IN 46204 KEYWORDS: states, permitting, permit program, rulemaking ABSTRACT At the end of 2016, the United States Congress authorized states to establish permit programs for coal combustion residuals (CCR) surface impoundments and landfills.[1] Since then, several states have established such programs, and the United States Environmental Protection Agency (U.S. EPA) has approved programs for Oklahoma,[2] Georgia,[3] Texas,[4] and North Dakota,[5] proposed approval for Wyoming,[6] and denied approval for Alabama.[7] Other states, such as Indiana,[8] are actively working through the state rulemaking process and plan …

From Clogs To Compliance: Overcoming Persistent Leachate Head Issues In Ccr Landfills, Breanne Kahnk, Zachary Bauman

World of Coal Ash Proceedings

State and federal regulations require that landfills, including coal combustion residual (CCR) landfills, be designed and operated to maintain leachate head levels of less than 30 centimeters (approximately 1 foot). While proper leachate collection system design and routine maintenance are critical for meeting this requirement, challenges such as clogging of drainage media, pipes, fittings and/or pipeline perforations, settlement of collection pipes, and breaks in the piping system can lead to elevated leachate levels, posing risks to compliance and long-term system performance. TRC will provide an overview of leachate collection system regulatory requirements along with design, operation, and maintenance strategies that …

Providing Perspective On Arsenic Risks In The Human Health Risk Evaluation Of Coal Combustion Products (Ccps), Ari Lewis

World of Coal Ash Proceedings

Arsenic has been a key risk factor in the evaluations for the 2015 Coal Combustion Residuals (CCR) Rule and the recent “Legacy Rule”, which addresses areas of historical CCP placement not covered by the 2015 rule. These risk assessments concluded that cancer risks from arsenic in various waste management scenarios exceeded the U.S. Environmental Protection Agency's (USEPA) target of 1 in 100,000 excess lifetime cancer cases, forming part of the basis for national CCP regulations. However, background exposure to naturally occurring arsenic in food, water, and soil also exceeds permissible levels, complicating risk conclusions. The USEPA's recent revision of arsenic …