Pharmaceutical sciences student, Sara Dumit, is studying the decorporation of plutonium from the human body during treatment with chelating agents such as Ca-EDTA and CA/Zn-DTPA. These chelating agents bind to plutonium in the blood, and enhance its excretion from the body. They also reduce the amount of plutonium in the liver. Clearly, decorporation therapy alters the retention and clearance of plutonium from the body. Consequently, the accepted biokinetic models for interpreting urinalysis data cannot be used unless the effects of decorporation therapy are accounted for.
The goal of Ms. Dumit’s research is to develop and parameterize a biokinetic model for plutonium decorporation therapy. She has modeled the biokinetic behavior of plutonium in USTUR case 0785 as a preliminary step toward this goal.
An explosion involving plutonium nitrate [Pu(NO3)4] exposed USTUR case 0785 to plutonium via inhalation and wounds. Three months after the accident, the worksite estimated that he had a 7.4 kBq plutonium body burden. When he retired 31 years later, the worksite estimated that his body contained 8.1 kBq.
Ms. Dumit used the IMBA Professional Plus software to estimate the residual intake, i.e., the plutonium not removed by decorporation therapy. She accomplished this by simultaneously fitting the bioassay data and the amount of plutonium measured post-mortem in the liver, skeleton, and lungs. The estimated residual intake was 34.1 kBq (97% inhalation; 3% wound), and the residual committed effective dose was 1.09 Sv.
Since 0.7 kBq of plutonium was excreted in urine during decorporation treatment, the total plutonium intake was 34.8 kBq. This corresponds to a committed effective dose of 1.11 Sv. Thus, only a 2% radiation dose reduction was achieved with decorporation therapy.
Ms. Dumit is expanding these preliminary findings to develop and parameterize a biokinetic model for plutonium decorporation therapy. Her graduate committee members are:
- Dr. Sayed Daoud (Chair)
- Dr. Kathryn E. Meier
- Dr. Jeannie Padowski
- Dr. Daniel J. Strom
- Dr. Sergei Y. Tolmachev (Advisor)