RENEB accident simulation exercise

Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event. Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners. Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes). Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested

The Lack of Cytotoxic Effect and Radioadaptive Response in Splenocytes of Mice Exposed to Low Level Internal β-Particle Irradiation through Tritiated Drinking Water in Vivo

Health effects of tritium, a β-emitter and a by-product of the nuclear industry, is a subject of significant controversy. This mouse in vivo study was undertaken to monitor biological effects of low level tritium exposure. Mice were exposed to tritiated drinking water (HTO) at 10 KBq/L, 1 MBq/L and 20 MBq/L concentrations for one month. The treatment did not result in a significant increase of apoptosis in splenocytes. To examine if this low level tritium exposure alters radiosensitivity, the extracted splenocytes were challenged in vitro with 2 Gy γ-radiation, and apoptotic responses at 1 and 24 h were measured. No alterations in the radiosensitivity were detected in cells from mice exposed to tritium compared to sham-treated mice. In contrast, low dose γ-irradiation at 20 or 100 mGy, resulted in a significant increase in resistance to apoptotic cell death after 2 Gy irradiation; an indication of the radioadaptive response. Overall, our data suggest that low concentrations of tritium given to mice as HTO in drinking water do not exert cytotoxic effect in splenocytes, nor do they change cellular sensitivity to additional high dose γ-radiation. The latter may be considered as the lack of a radioadaptive response, typically observed after low dose γ-irradiation

EURADOS REVIEW OF RETROSPECTIVE DOSIMETRY TECHNIQUES FOR INTERNAL EXPOSURES TOIONISING RADIATION AND THEIR APPLICATIONS

International audienceThis work presents an overview of the applications of retrospective dosimetry techniques in case ofincorporation of radionuclides. The fact that internal exposures are characterized by a spatiallyinhomogeneous irradiation of the body, which is potentially prolonged over large periods andvariable over time, is particularly problematic for biological and electron paramagnetic resonance(EPR) dosimetry methods when compared to external exposures.The paper gives initially specific information about internal dosimetry methods, the most commoncytogenetic techniques used in biological dosimetry and EPR dosimetry applied to tooth enamel.Based on real case scenarios, dose estimates obtained from bioassay data as well as with biologicaland/or EPR dosimetry are compared and critically discussed.In most of the scenarios presented, concomitant external exposures were responsible for the greaterportion of the received dose. As no assay is available which can discriminate between radiation ofdifferent types and different LETs on the basis of the type of damage induced, it is not possible toinfer from these studies specific conclusions valid for incorporated radionuclides alone. The biologicaldosimetry assays and EPR techniques proved to be most applicable in cases when the radionuclidesare almost homogeneously distributed in the body. No compelling evidence was obtained in othercases of extremely inhomogeneous distribution. Retrospective dosimetry needs to be optimized andfurther developed in order to be able to deal with real exposure cases, where a mixture of bothexternal and internal exposures will be encountered most of the times