Radiobioassay & Radiochemical Measurements Conference, Jackson Hole, WY, Oct. 29 – Nov. 2, 2007
The USTUR and their research collaborators contributed two presentations at the 53rd Annual Radiobioassay and Radiochemical Measurements Conference (RRMC), Jackson Hole, WY, October 29 – November 2, 2007.
Determination of Pu and Am in digested bone and soft tissue samples by SF-ICP-MS: comparison with α-spectrometry
Sergei Tolmachev (USTUR), Michael Ketterer (Northern Arizona University), Dorothy Stuit (USTUR) and Anthony James (USTUR)
Dr. Sergei Tolmachev, USTUR’s Radiochemistry Laboratory Manager, described a new USTUR initiative to apply Sector Field (High Resolution) Inductively Coupled Plasma Mass Spectrometry (SF-ICP-MS) to obtain more comprehensive isotopic composition data from samples of donated human tissues, while also reducing the cost of sample analysis over α-spectrometry. This work is being carried out with Dr. Michael Ketterer, Professor of Chemistry and Biochemistry, College of Engineering and Natural Sciences, Northern Arizona University (NAU), Flagstaff, AZ. The initial results are highly promising. These include demonstrating the ability of SF-ICP-MS to measure directly 241Am and its soft-β emitting parent 241Pu in lung, lymph node and liver samples, and 234,235,238U in all tissue samples (including those from donors occupationally exposed only to plutonium/americium). For uranium-exposed donors, the 236U:238U atomic ratio can also be measured. These new measurement capabilities will enable USTUR (and the scientific community) to interpret and model USTUR case data in significantly greater depth, for example, by resolving definitively for an individual donor the components of actinide burden (and tissue dose) contributed by multiple intake events (different materials). This SF-ICP-MS work will be continued by NAU in FY2008, under sub-contract from Washington State University (WSU)/USTUR. [USTUR-0234-07]
Comparison of 241Am organ activity from radiochemistry and direct measurements
Tim P. Lynch (Battelle), Sergei Y. Tolmachev (USTUR) and Anthony C. James (USTUR)
Mr. Timothy Lynch, Pacific Northwest National Laboratory’s (PNNL) In Vivo Monitoring Program Manager, Radiation and Health Technology, described recent results of a collaborative project between PNNL and USTUR. Tim chaired the “DOE Lung Intercalibration Committee Workshop” at the RRMC 2007 Conference, introducing this with a presentation entitled “Comparison of 241Am Organ Activity from Radiochemistry and Direct Measurements.” PNNL (and its Hanford predecessors) have followed a select group of USTUR (and its predecessors’) Registrants through their employment at Hanford, and with high resolution measurements of externally emitted 241Am 59 keV γ-ray post mortem (prior to autopsy). Comparison of the “in vivo” (external) measurement estimates of skeletal, lung and liver 241Am content with USTUR’s tissue radiochemical analysis results provides a unique opportunity to determine how accurate and reliable these operational “in vivo” measurements are in each case. The donors were variously exposed by inhalation or skin wound, and to various types of actinide materials. This collaborative study will be continued in FY2008 under WSU/USTUR sub-contract to PNNL. [USTUR-0235-07]