The 2018 Meeting of the Conference on Radiation & Health: The Public Health Impact of Radiation Exposures, Latest Insights from Biology, Epidemiology, and Statistics was held in conjunction with the Radiation Research Society’s annual meeting. This year marks fifty years since the Registries was founded in 1968. Appropriately, USTUR director, Sergei Tolmachev, discussed 50 years of USTUR contributions to our understanding of plutonium in humans during his invited lecture at the special session on Department of Energy (DOE) health studies. Additionally, Maia Avtandilashvili presented a poster, which summarized the four-decade follow up of a worker who was chelated following a plutonium-contaminated puncture wound.
The United States Transuranium and Uranium Registries: Fifty Years of Contributions to Understanding of Plutonium in Humans
Sergei Y. Tolmachev (USTUR) and Joey Zhou (DOE)
This presentation marks the 50th anniversary of the United States Transuranium and Uranium Registries (USTUR). The potential toxicity of plutonium was recognized during the early days of the Manhattan Project. The mission of the USTUR is to study the uptake, translocation, retention and excretion (biokinetics), and tissue dosimetry of internally deposited actinides (uranium, plutonium, and americium) in occupationally exposed volunteer tissue donors. The USTUR is an invaluable national and international resource for testing and improving the application of bioassay data to predict tissue dose rates measured at autopsy. Postmortem radiochemical analyses of tissues obtained at autopsy have led to improved knowledge on distribution and long-term retention of 239Pu and 238Pu in the human body and have helped in parameterizing biokinetic constants for these radionuclides. The USTUR’s research is fundamental to evaluating and improving the reliability of, and confidence in, both prospective and retrospective assessments of tissue radiation doses and risks from intakes of plutonium and other actinides. These data are vital for refining the biokinetic models underlying safety standards for these radioactive elements. Since 1992, Washington State University has successfully operated the USTUR, and the associated National Human Radiobiology Tissue Repository (NHRTR) as a grant research project administered by the College of Pharmacy. Currently, the USTUR holds records and data for 309 partial-body donors and 45 whole-body donors. The NHRTR has preserved and held frozen tissue samples, histological slides, and formalin-fixed paraffin-embedded tissue blocks from 158 donations (114 partial-body and 34 whole-body). NHRTR materials are a valuable, however, underexplored, resource for other studies such as biomarker and cytogenetic research. [USTUR-0505A-18]
Four-Decade Follow-Up of Plutonium-Contaminated Puncture Wound Treated with Ca-DTPA
Maia Avtandilashvili (USTUR) and Sergei Y. Tolmachev (USTUR)
Contaminated wounds are a major route of internal deposition of radionuclides for nuclear and radiation workers. They may result in significant doses to the radiosensitive organs and tissues in an exposed individual’s body. The U.S. Transuranium and Uranium Registries’ whole-body donor (Case 0303) accidentally punctured his finger. The wound was contaminated with plutonium nitrate. The wound was surgically excised and medically treated with intravenous injections of Ca-DTPA. A total of 16 g Ca-DTPA was administered in 18 treatments during two months following the accident. Eighty-seven urine samples were collected and analyzed over 14 years following the accident. An estimated 239Pu activity of 78 Bq was excreted during Ca-DTPA treatment. Post-mortem radiochemical analysis of autopsy tissues indicated that forty years post-accident 12.2±0.3 Bq of 239Pu was retained in the liver and 17.5±0.7 Bq in the skeleton. To estimate the plutonium intake, late urine measurements, which were unaffected by chelation, and post-mortem radiochemical analysis results were evaluated using the IMBA Professional Plus software. Application of the NCRP 156 wound model with default parameters for soluble strong material resulted in a credible fit to the data (p > 0.05). The residual intake was estimated to be 47.6 Bq that resulted in committed effective dose of 24.1 mSv. Ca-DTPA treatment reduced this individual’s radiation dose by a factor of 2.6. [USTUR-0503A-18]