RENEB/EURADOS field exercise 2019: robust dose estimation under outdoor conditions based on the dicentric chromosome assay

International audiencePurpose: Biological and/or physical assays for retrospective dosimetry are valuable tools torecover the exposure situation and to aid medical decision making. To further validate andimprove such biological and physical assays, in 2019, EURADOS Working Group 10 and RENEB performeda field exercise in Lund, Sweden, to simulate various real-life exposure scenarios.Materials and methods: For the dicentric chromosome assay (DCA), blood tubes were located atanthropomorphic phantoms positioned in different geometries and were irradiated with a 1.36TBq 192Ir-source. For each exposure condition, dose estimates were provided by at least onelaboratory and for four conditions by 17 participating RENEB laboratories. Three radio-photoluminescenceglass dosimeters were placed at each tube to assess reference doses.Results: The DCA results were homogeneous between participants and matched well with the referencedoses ( 95% of estimates within ±0.5 Gy of the reference). For samples close to the sourcesystematic underestimation could be corrected by accounting for exposure time. Heterogeneitywithin and between tubes was detected for reference doses as well as for DCA doses estimates.Conclusions: The participants were able to successfully estimate the doses and to provide importantinformation on the exposure scenarios under conditions closely resembling a real-life situation