Inhalation of Soluble Plutonium: 53-year Follow-up of Manhattan Project Worker

Abstract

This whole-body tissue donor to the United States Transuranium and Uranium Registries was occupationally exposed to plutonium nitrate-dioxide mixture via chronic inhalation. This individual was involved in the Manhattan Project operations and later participated in medical follow-up studies. Soft tissues and bones collected at autopsy were analyzed for 238Pu, 239+240Pu, and 241Am. Fifty-three years post-intake, 700±2 Bq of 239+240Pu were still retained in the skeleton, 661±11 Bq in the liver, and 282±3 Bq in the respiratory tract. Bioassay measurements and organ activities at the time of death were used to estimate the intake and radiation doses using the TAURUS internal dosimetry software. For this individual, an ICRP Publication 130 Human Respiratory Tract Model with case-specific particle size of 0.3 μm, ICRP Publication 100 Human Alimentary Tract Model, and ICRP Publication 141 Plutonium Systemic Model adequately described long-term plutonium retention and excretion. The total cumulative 239+240Pu intake of 31,716 Bq was estimated, of which 24,853 Bq (78.4%) were contributed by inhalation of plutonium nitrate and 6,863 Bq (21.6%) of plutonium dioxide. The committed equivalent doses to the red bone marrow, bone surface, liver, lungs, and brain were 0.71 Sv, 6.5 Sv, 8.3 Sv, 3.8 Sv, and 0.068 Sv, respectively. The committed effective dose was 1.22 Sv.

Plutonium in Manhattan Project workers: Using autopsy data to evaluate organ content and dose estimates based on urine bioassay with implications for radiation epidemiology

“…IMBA (Integrated Modules for Bioassay Analysis) Professional Plus ® version 5.0 [ 36 , 37 ] with the ICRP 130 Human Respiratory Tract model, ICRP 141 Plutonium Systemic model, and ICRP 30 Gastrointestinal Tract model was used to predict intakes and plutonium activity in the liver and skeleton at the time of death [ 38 – 40 ]. Biokinetic modelling of Case 0680, whose data was included in this study, was described in detail in a recent article [ 41 ]. All individuals investigated in this group had worked at the same worksite, and therefore, it was assumed they had been exposed to the same plutonium mixture with particle size of 0.3 μm AMAD (activity median aerodynamic diameter).…”

“…All individuals investigated in this group had worked at the same worksite, and therefore, it was assumed they had been exposed to the same plutonium mixture with particle size of 0.3 μm AMAD (activity median aerodynamic diameter). A super-complex intake scenario (SCIR) with fixed material composition of 78% of Pu-nitrate and 22% of PuO 2 , which was derived for Case 0680 [ 41 ], was applied. SCIR is a mode in IMBA that allows the user to fit several intake regimes as one intake.…”

“…The sum of the liver and skeleton activities was used for intake predictions to serve as a robust measure of systemic plutonium activity [ 42 ]. For the purpose of calculations, the error in the liver+skeleton activity was assumed to follow a normal distribution with a relative standard deviation of 0.1 [ 41 , 43 , 44 ]. Urine bioassay errors were assumed to be distributed lognormally with a geometric standard deviation (GSD) of 3.0 for measurements before 1949, a GSD of 2.0 for measurements between 1949 and 1957, and a GSD of 1.6 for measurements after 1957 [ 45 ].…”

Four-decade follow-up of a plutonium-contaminated puncture wound treated with Ca-DTPA

“…The activity in the skeleton was calculated by summing up the measured activities in analysed bones from the right side of the skeleton including oddnumbered ribs and vertebrae, as well as activities estimated for the remaining, non-analysed bones based on bilateral symmetry of the human body. The detailed methodology of the skeletal activity estimation is described elsewhere (McInroy et al 1985, Šefl et al 2021.…”