We want to welcome the newest member of the USTUR research faculty, Xirui Liu. Ms. Liu has worked with the USTUR as a student collaborator since 2019, where her research focused on using autopsy reports to determine how often the underlying causes of death found on death certificates are incorrect. Ms. Liu has both a master’s degree in health informatics from Weill Cornell Medicine (2022), and a master’s in public health in international health and development from Tulane University (2021). She also earned her Bachelor of Medicine, Bachelor of Surgery degree from Huazhong University of Science and Technology, China in 2017. Ms. Liu will expand her original research to explore how under- and over-classification of diseases on death certificates affects risk estimates in epidemiological studies.

Curriculum Vitae

USTUR research assistant professor, Maia Avtandilashvili, and adjunct professor, Daniel Strom, have been selected to serve on the science advisory board that will conduct a peer review of the Environmental Protection Agency’s draft document Federal Guidance Report No. 16. FGR 16 “Cancer Risk Coefficients for Environmental Exposure to Radionuclides” is an update to FGR 13, which was published in 1999.

Join WSU Tri-Cities and the Herbert M. Parker Foundation to hear Werner Rühm discuss the process of updating International Commission on Radiological Protection’s (ICRP) recommendations for protecting people and the environment against radiation exposure. Dr. Rühm is the ICRP Main Commission chair and leads the Medical and Environmental Dosimetry Group at the Helmholtz Center, Munich Institute of Radiation Medicine in Germany. Visit the link below to watch.

Wednesday November 2, 12 p.m. – 1:30 p.m. PST
bit.ly/parkerlecture
Lecture Flier

George Tabatadze was interviewed by WSU Health Sciences Spokane Office of Research about his work at the USTUR. Dr. Tabatadze is an assistant professor at the USTUR, where his work focuses on radiation measurements and associated research. Continue reading to learn about the work conducted at the USTUR, and Dr. Tabatadze’s role in that work.

Researcher on the Rise: Q&A with George Tabatadze

Interview by Judith Van Dongen, reproduced with permission
Original article: https://spokane.wsu.edu/research/news/researcher-on-the-rise-george-tabatadze/

Radiation is used to produce energy, power spacecraft and satellites, and diagnose and treat disease, among other uses. Exposure to radiation comes with safety risks, which are at the heart of the work done by research assistant professor George Tabatadze and his colleagues at the United States Transuranium and Uranium Registries (USTUR), a Tri-Cities-based research unit housed in the WSU College of Pharmacy and Pharmaceutical Sciences.

Tell us more about what USTUR does.

We study the biokinetics, dosimetry, and possible biological effects of radioactive elements like plutonium, americium, and uranium within the human body. We do this by studying organs and tissue samples from former U.S. nuclear workers with known radioactive exposure who have voluntarily donated their bodies—or parts of them—after their death. USTUR has a long history that started with the creation, in 1968, of the National Plutonium Registry, which changed its name to U.S. Transuranium Registry two years later. In 1978, the U.S. Uranium Registry was established. Both registries involved multiple labs and organizations at various locations that were working under government contract. In 1992, the two registries merged and became the WSU research unit known as USTUR. All of the work is now done in one central location that is housed close to the former nuclear production complex at Hanford. USTUR has been fully grant funded by the U.S. Department of Energy (DOE) since its founding.

What is the significance of the work done at USTUR?

We operate in the field of health physics, a profession that emerged during World War II after plutonium was created as a new material for nuclear weapons production. The first health physicists were industrial hygienists and MDs who were in charge of taking care of workers’ health at those facilities. They were the first to notice the effects of radiation, such as skin lesions and blistering at high doses and higher incidence of cancer at lower doses. Here at USTUR, we generate data and science that is used by scientists all over the world and by national and international scientific organizations such as the International Commission on Radiological Protection (ICRP) and the National Council on Radiation Protection and Measurements (NCRP). ICRP and NCRP use our work to develop recommendations for radiation dose limits and to refine models used to measure how radiation dose affects the human body. Those recommendations are used by other agencies such as the Nuclear Regulatory Commission and the DOE to regulate the use of radiation and limit radiation exposure to workers and the general public.

What drew you to the field of health physics and brought you to USTUR?

Physics was my passion always. I got my undergraduate degree in physics and computer science at Tbilisi State University in my home country of Georgia. It was mostly theoretical physics, and I really wanted to focus more on applied science. So I came to the U.S. to pursue a master’s degree in health physics with an emphasis in medical physics at the University of Nevada Las Vegas. There, I completed a research project aimed at understanding how the distribution of alpha-particle-emitting radioactive material in the human body affects bone, one of the organs that is the most sensitive to this type of radiation. After that, I briefly worked in medical physics consulting, visiting hospitals to determine whether their radiation-producing medical equipment met state regulations on radiation emissions. However, my passion was always to do research, and so I pursued a PhD at Idaho State University (ISU) Health Physics Program. ISU had a collaboration with USTUR at the time, and I spent several years working on the ISU/USTUR internal dosimetry team as part of my PhD project before officially joining USTUR in 2014.

What is your role within USTUR?

I’m in charge of the measurement of radioactive elements in tissue samples, data analysis, and laboratory quality assurance and quality control. Additionally, I use a machine called an autoradiography imager to gain a better understanding of the distribution of different types of radioactive materials in different tissues and organs on a micro scale, as part of my interest in microdosimetry. When we understand the radioactive dose delivered to specific organs or tissues, we can potentially translate that into the risk of developing disease.

One big project I’ve been working on for the past year and a half is developing the USTUR quality assurance program plan. Although health physicists have been measuring radiation dose since the 1940s, advances in technology and our understanding of the data itself provide us with an opportunity to better control the quality of the data we generate.

What do you enjoy most about the research that you do?

I have always been fond of human health, and half of my family consists of medical doctors. My current career is the perfect marriage between science, biology, and medicine. I really enjoy helping people by understanding the effects of radiation and contributing to the development of models that will better predict radiation dose to humans.

What are the gaps in knowledge in health physics research?

The almost century-old, million-dollar question is what the effects of low-dose radiation are. The effects of high-dose radiation are well-known from nuclear accidents like the Chernobyl disaster and nuclear bomb survivor studies at Hiroshima and Nagasaki. But the data on the effects of lower dose radiation is quite uncertain and so spread out that given the same data multiple conflicting conclusions could be drawn. Our work is trying to contribute to filling that gap. What it will take is lots of data to minimize the uncertainty and be able to develop a better model to predict the effects of low doses of radiation.

What has it been like working at USTUR?

It’s been really nice to be part of the team here at the USTUR. I’m extremely grateful to my fellow USTUR faculty Sergei Tolmachev, Maia Avtandilashvili, Stacey McComish, Dan Strom, and Martin Šefl, as well as USTUR staff Elizabeth Thomas, Florencio Martinez, and Margo Bedell. We work as a unit and help each other to do better research. As we always say, a few minds are better than one.

This interview has been edited and condensed for clarity.

The USTUR’s 2022 Annual Report has been completed and is available for download. The document summarizes organization, activities, and scientific accomplishments at the USTUR from April 1, 2021 to March 31, 2022 (fiscal year 2022). Research summaries include: latent bone modeling, Electron Paramagnetic Resonance (EPR) dosimetry, and radium in the human brain.

Download Report

Martin Šefl gave a seminar presentation to undergraduate students from Whitman College in Walla Walla, Washington. His presentation, which is a part of the Mathematical Sciences Foundry Talks series, explained how a principal component regression was used to estimate the total amount of plutonium in the entire skeleton, based on the activity concentrations in a limited subset of bones. This approach is preferred to calculating an arithmetic mean, because it reduces the risk of bias for non-representative bone sampling, utilizes all available information, and reduces the uncertainty.

Seminar slides (PPTX with animation)
Seminar slides (PDF)

On September 19, Martin Šefl will give a seminar presentation to undergraduate mathematics and statistics students from Whitman College in Walla Walla, Washington. His presentation, which is a part of the Mathematical Sciences Foundry Talks series, will describe how a principal component regression can be used to estimate the total amount of plutonium in the entire skeleton, based on the activity concentrations in a limited subset of bones. When a person wills their entire body to the USTUR, laboratory staff measure the amount of plutonium in each of the 90 bone samples that are removed from the right side of the body. It is a straightforward task to add up all of individual bone activities, and multiply by two, to estimate the amount of plutonium in the entire skeleton. However, the bulk of donations to the USTUR are partial body donations, where typically two to eight bones are donated to the USTUR for radiochemical analysis. The concentration of plutonium in these bones must be used to calculate the concentration in the entire skeleton, which can then be used, along with the skeletal weight, to calculate the total activity in the skeleton. There are several methods for estimating the skeletal concentration from a limited subset of bones, and each method has its limitations. Notably, a multiple regression is not an appropriate tool for calculating the concentration of plutonium in the skeleton, because bone concentrations are highly correlated with each other. A principal component regression addresses the multicollinearity among bones, making it a more appropriate tool for this application. A brief introduction to principal component regression will be provided, and its application for estimating the plutonium concentration in the skeleton will be discussed.

View abstract

George Tabatadze was reappointed as a member of the WSU Radiation Safety Committee (RSC), which he has served on since 2019. His new appointment has a three-year term, and ends in August 2025. The RSC establishes and ensures compliance with radiation protection policies, reviews applications for and approves use of radioactive materials and radiation producing machines, and audits Radiation Safety Office records.

Dr. Tabatadze is a research assistant professor at the USTUR, where he maintains and operates radiation detection instrumentation, heads up the laboratory’s effort to revise its quality assurance plan, and conducts quantitative analysis of data. He has served as a member of several organizations, including the Board of Trustees for the Herbert M. Parker Foundation, the Health Physics Society’s International Collaboration Committee, and the Columbia Chapter of the Health Physics Society, where he is a past president and is currently serving as a council member.

Daniel Strom, an adjunct professor at the USTUR, has been nominated to serve as a primary member on the Hanford Advisory Board, where he will represent local and regional public health. The Hanford Advisory Board provides “informed recommendations and advice to the U.S. Department of Energy (DOE), the U.S Environmental Protection Agency (EPA), and the Washington Department of Ecology (Ecology) on selected major policy issues related to the cleanup of the Hanford site.”⁽¹⁾ Dr. Strom is currently serving a two-year term as an alternate member of the board.

⁽¹⁾ https://www.hanford.gov/page.cfm/hab

Sara Dumit has been selected to receive the 2022 John D. Boice Young Investigator Award from the National Council on Radiation Protection and Measurements. Dr. Dumit completed her PhD in pharmaceutical sciences at Washington State University. Her research utilized USTUR data to study the decorporation of plutonium from the human body during treatment with chelating agents such as DTPA. She continues to study actinide chelation and develop biokinetic models as a part of her work as a Health Physicist at Los Alamos National Laboratory (LANL). During 2021, Dr. Dumit also had the distinction of attending the Lindau Nobel Laureate Meeting. The meeting, which was held virtually, provided her with the unique opportunity to interact with Nobel Laureates from around the world.

For more information about Dr. Dumit’s selection for this award, visit the NCRP website.