Published October 24, 2022, on WSU Spokane Research News by Judith Van Dongen
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.