Nordic collaboration within biological dosimetry

Access to biological dosimetry capabilities is critical in the event of a radiation accident to support the medical decisions for treatment of casualties. However, since radiological accidents are not very common, not all countries consider it economically justified to maintain biological dosimetry laboratories. In Nordic countries this situation occurs in three non nuclear power plants countries: Norway, Denmark and Iceland. Biological dosimetry is presently performed in this region in two laboratories: It has been established for many years at STUK- Radiation and Nuclear Safety Authority and in the last few years, at FOI, The Swedish Defence Research Agency has been developing methods in this area as well. Both Norway and Denmark have an informal agreement with STUK to perform biological dosimetry on their behalf. However, in the event of the situation involving many casualties, the capacity of a single laboratory could be overwhelmed and the sharing of competence and capabilities within the countries is vital. Therefore from 2005, FOI, STUK and NRPA have been working together to optimize a method for biological assessment of radiation dose for specific application in emergency preparedness. This two-year Nordic Nuclear Safety Research (NKS)-funded BIODOS project has aimed at improved methods for biodosimetry that have specific application in emergency preparedness. An assay in which chromosomes are prematurely condensed (PCC) was investigated. PCC provides a potentially faster means of analysis as well as the ability to assess higher doses than with the dicentric assay which is routinely applied in biodosimetry. The results from the BIODOS project have indicated that a PCC protocol utilizing okadaic acid is adequate for induction of PCC cells in stimulated lymphocytes for the subsequent evaluation of ring chromosomes. The final step in the BIODOS project involved establishment of a dose response curve for the PCC ring method and a preliminary comparison of the assay method to the traditional dicentric assay in triage mode. The triage method requires a minimal number of evaluations so that categorization of high, medium and low doses may be made in an emergency situation where large numbers of people should be evaluated. The collaboration between STUK, FOI and NRPA continues in 2008 with the new NKS project BIOPEX that has the aim to test and evaluate the applicability of the PCC assay in a simulated triage exercise involving a large number of exposed casualties. (author)