EURADOS intercomparison on emergency radiobioassay

Abstract

Nine laboratories participated in an intercomparison exercise organised by the European Radiation Dosimetry Group (EURADOS) for emergency radiobioassay involving four high-risk radionuclides ((239)Pu, (241)Am, (90)Sr and (226)Ra). Diverse methods of analysis were used by the participating laboratories for the in vitro determination of each of the four radionuclides in urine samples. Almost all the methods used are sensitive enough to meet the requirements for emergency radiobioassay derived for this project in reference to the Clinical Decision Guide introduced by the NCRP. Results from most of the methods meet the requirements of ISO 28218 on accuracy in terms of relative bias and relative precision. However, some technical gaps have been identified. For example, some laboratories do not have the ability to assay samples containing (226)Ra, and sample turnaround time would be expected to be much shorter than that reported by many laboratories, as timely results for internal contamination and early decisions on medical intervention are highly desired. Participating laboratories are expected to learn from each other on the methods used to improve the interoperability among these laboratories.

Magnetic iron oxide and manganese-doped iron oxide nanoparticles for the collection of alpha-emitting radionuclides from aqueous solutions

“…Urine was selected as a complex biological fluid with relevance to routine or emergency in vitro radiobioassay applications. 39–41 The four alpha-emitting radionuclides chosen for this study possess an array of different valence states and chemical complex formation across the different aqueous solutions and varied pH.…”

Ghsi Emergency Radionuclide Bioassay Laboratory Network: Summary of a Recent Exercise

“…Lab 008 and Lab 009 quantified 241 Am in the sample using gross alpha liquid scintillation counting and gamma spectrometry, with a counting time of 17 hours and 68 hours, respectively. The advantages and disadvantages of different methods/techniques for emergency bioassay have been discussed previously (6) ; however, it is worthwhile to note that bioassay methods that deliver results in hours rather than days are always desired for emergency population monitoring and management as early medical interventions, if indicated necessary by bioassay results, help reduce radiation induced health risks more effectively.…”

“…The following scenario and parameters were chosen or considered:

Acute intake of 241 Am (1.50 MBq) via ingestion by a man with physical characteristics similar to a “Reference Man” described by the International Commission on Radiological Protection (ICRP) (5) ;

Urine collection started 24 hours after the suspected intake and lasted for 24 hours. One 100 mL urine sample from this collection would be sent to each laboratory (to mimic a spot sample).

Laboratories were required to report their results at short, pre-determined intervals in order to simulate an emergency response.The level of contamination in the scenario was chosen to accommodate the bioassay capabilities previously demonstrated by some of the participating laboratories (6) , as well as to approach the dose thresholds for medical intervention recommended by national or international authorities (4, 7) .…”

“…The level of contamination in the scenario was chosen to accommodate the bioassay capabilities previously demonstrated by some of the participating laboratories (6) , as well as to approach the dose thresholds for medical intervention recommended by national or international authorities (4, 7) .…”

How to assess internal doses for epidemiological studies and for emergency response? An overview of differences with routine operational radiation protection approach

“…In vitro measurements of the excretion rate in biological samples (mainly in urine and feces) of potentially internally exposed people are carried out when the radioactive release consists of alpha-or beta-emitters with photon emissions of very low energy or intensity, if the accident scenario involves uranium or actinide releases not measurable by in vivo monitoring, to confirm internal contamination in case of persistent external contamination and to improve the assessment of the internal dose when the exposure is significant [6; 7] . [20][21][22] . The objective of all these actions is for laboratories to develop and to validate methods with sensitivity enough to meet the requirements for emergency bioassay in typical nuclear accident scenarios.…”