[en] The aim of this work was to determine the possible occurrence of damage to the immune system during the course of chronic ingestion of ¹³⁷Cs. BALB/C mice were used, with ¹³⁷Cs intake via drinking water at a concentration of 20 kBq l^-1. Adults received ¹³⁷Cs before mating and offspring were sacrificed at various ages between birth and 20 weeks. Phenotypic analysis of circulating blood cells and thymocytes did not show any significant modification of immune cell populations in animals ingesting ¹³⁷Cs as compared with control animals, with the exception of a slight increase in Treg percentage at the age of 12 weeks. Functional tests, including proliferative response to mitogens such as phytohaemagglutinin, response to alloantigens in mixed lymphocyte reaction and immunoglobulin response to vaccine antigens such as tetanus toxin and keyhole limpet haemocyanin did not show any significant functional modification of the immune system in ¹³⁷Cs-ingesting animals as compared with control animals. Overall, our results suggest that chronic ingestion of a low concentration of ¹³⁷Cs in drinking water in the long term does not have any biologically relevant effect on the immune system.

[en] Safety is not just an engineering discipline that consists of accumulating technological countermeasures to prevent any incident. It is a multi-disciplinary field that takes into account physics, biology, human and environmental sciences. Its ability to adapt to the realities of the field and to the capabilities of those involved, without ever giving in to complexity, is essential to ensure the greatest possible efficiency. This dossier reviews 11 key points about nuclear safety: 1 - Engineering? Safe systems must leave plenty of room for human intelligence; 2 - Stress corrosion, a look back at an unprecedented year; 3 - French reactors are safer than when they were commissioned; 4 - Nuclear power and safety: an overview of different approaches around the world (USA, UK, China); 5 - Safety and complexity: the limits of managerial action; 6 - The Nuclear Rapid Response Force continues to evolve; 7 - Heat wave 2022: water issues for nuclear operations; 8 - People's lives and radiation protection in contaminated areas; 9 - The biological effects of ionizing radiations; 10 - Protect, repair: French doctrine after a nuclear accident; 11 - Looking back: the main approaches to safety

[en] Procedures using iodine-131 represent more than 90% of all therapies in nuclear medicine in Algeria. It is important to evaluate the long-term biological effects of iodine treatment on non-target organs to improve patient radiation protection. This experimental radiotoxicology study aims to determine the biokinetic models of iodine contamination. For this purpose, two Wistar rat models, with and without a thyroid, have been used to evaluate the biological half-life of iodine and then to perform a biodistribution study of iodine activity in 15 organs and tissues. For the most relevant organs, the respective absorbed doses have been calculated using RODES software. (paper)

[en] Exposures in post-accidental situations are complex and include both external exposure and internal contamination with several radionuclides. However, in vivo and in vitro studies generally use simplified exposures, while a recent study suggested that combined external irradiation and internal contamination may induce more severe biological effects compared to single exposures. In an attempt to test the hypothesis of potential non-additive effects of multiple radiological exposures, we used a mouse model of combined external x-ray irradiation at 1 and 5 Gy and internal contamination with injection of 20 KBq ¹³⁷Cs. The results showed differential kinetics of ¹³⁷Cs elimination in irradiated animals compared to sham-irradiated, ¹³⁷Cs injected animals. Moreover, changes in plasma potassium and in relative testis weight were observed 38 days after irradiation and injection in co-exposed animals compared to ¹³⁷Cs injection alone. These results demonstrate that an external exposure combined with an internal contamination may lead to unexpected changes in biokinetics of radionuclides and biological effects compared to single exposures. (paper)

[en] In order to support animal experiments of chronic radionuclides intake with realistic dosimetry, voxel-based three-dimensional computer models of mice and rats of both sexes and three ages were built from magnetic resonance imaging. Radiation transport of mono-energetic photons of 11 energies and electrons of 7 energies was simulated with MCNPX 2.6c to assess specific absorbed fractions (SAFs) of energy emitted from 13 source regions and absorbed in 28 target regions. RODES software was developed to combine SAF with radiation emission spectra and user-supplied biokinetic data to calculate organ absorbed doses per nuclear transformation of radionuclides in source regions ( S -factors) and for specific animal experiments with radionuclides. This article presents the design of RODES software including the simulation of the particles in the created rodent voxel phantoms. SAF and S -factor values were compared favourably with published results from similar studies. The results are discussed for rodents of different ages and sexes. (paper)

[en] The presence of ¹³⁷Cesium (¹³⁷Cs) in the environment after nuclear accidents at Chernobyl and more recently Fukushima Daiichi raises many health issues for the surrounding populations chronically exposed through the food chain. To mimic different exposure situations, we set up a male rat model of exposure by chronic ingestion of a ¹³⁷Cs concentration likely to be ingested daily by residents of contaminated areas (6500 Bq.l⁻¹) and tested contaminations lasting 9 months for adult, neonatal and fetal rats. We tested plasma and serum biochemistry to identify disturbances in general indicators (lipids, proteins, carbohydrates and electrolytes) and in biomarkers of thyroid, heart, brain, bone, kidney, liver and testis functions. Analysis of the general indicators showed increased levels of cholesterol (+26%), HDL cholesterol (+31%), phospholipids B (+15%) and phosphorus (+100%) in the postnatal group only. Thyroid, heart, brain, bone and kidney functions showed no blood changes in any model. The liver function evaluation showed changes in total bilirubin (+67%) and alkaline phosphatase (–11%) levels, but only for the rats exposed to ¹³⁷Cs intake in adulthood. Large changes in 17β-estradiol (–69%) and corticosterone (+36%) levels affected steroidogenesis, but only in the adult model. This study showed that response profiles differed according to age at exposure: lipid metabolism was most radiosensitive in the postnatal model, and steroid hormone metabolism was most radiosensitive in rats exposed in adulthood. There was no evidence of deleterious effects suggesting a potential impact on fertility or procreation.

[en] The Research and Health Section of the French Society of Radiation Protection (SFRP) organized a technical meeting on the radiation protection aspects of dismantlement, from the dismantling work to the risk, the measurement of body contamination, the potentially harmful health effects, the available medical treatments, the actual needs and the developments in progress. This document brings together the abstracts and the presentations (slides) of the different talks given at the meeting: 1 - Situation: what radionuclides, what situations? (Philippe BERARD, CEA); 2 - Dismantling workplace experience feedback with internal contamination hazard (Philippe MOUGNARD, AREVA); 3 - Experience feedback on internal exposure monitoring at power plants in France (Michele GONIN, EDF); 4 - Evolution of routine and intervention measurement methods (Geraldine LECOIX, CEA); 5 - Evolution of radiation dose calculation models (Francois PAQUET, IRSN); 6 - Taking uncertainties into account in internal contamination monitoring protocols (Estelle DAVESNE, IRSN); 7 - Radionuclides behaviour and effects in men (Florence MENETRIER, CEA); 8 - The plutonium case (Henri METIVIER, SFRP); 9 - Cesium-137 and internal contamination: status and perspectives (Jean-Marc BERTHO, IRSN); 10 - Iodine and thyroid (Florence MENETRIER, CEA); 11 - Actual treatments and research pathways (Alexandra LEITERER, CEA); 12 - Radionuclide contamination treatment: new developments in the US (Rebecca ABERGEL, Berkeley USA); 13 - Internal contaminations treatment: French recent effort for its improvement (Olivier GREMY, CEA)

[en] The potential health impacts of chronic exposures to uranium, as they occur in occupational settings, are not well characterized. Most epidemiological studies have been limited by small sample sizes, and a lack of harmonization of methods used to quantify radiation doses resulting from uranium exposure. Experimental studies have shown that uranium has biological effects, but their implications for human health are not clear. New studies that would combine the strengths of large, well-designed epidemiological datasets with those of state-of-the-art biological methods would help improve the characterization of the biological and health effects of occupational uranium exposure. The aim of the European Commission concerted action CURE (Concerted Uranium Research in Europe) was to develop protocols for such a future collaborative research project, in which dosimetry, epidemiology and biology would be integrated to better characterize the effects of occupational uranium exposure. These protocols were developed from existing European cohorts of workers exposed to uranium together with expertise in epidemiology, biology and dosimetry of CURE partner institutions. The preparatory work of CURE should allow a large scale collaborative project to be launched, in order to better characterize the effects of uranium exposure and more generally of alpha particles and low doses of ionizing radiation. (paper)

[en] Purpose: To compare the efficacy of autologous cell therapy after irradiation combined with granulocyte-colony stimulating factor (G-CSF) injections with G-CSF treatment alone in a heterogeneous model of irradiation representative of an accidental situation. Material and Methods: Non-human primates were irradiated at 8.7 Gy whole-body dose with the right arm shielded to receive 4.8 Gy. The first group of animals received G-CSF (lenograstim) injections starting 6 h after irradiation, and a second group received a combination of G-CSF (lenograstim) injections and autologous expanded hematopoietic cells. Animals were followed up for blood cell counts, circulating progenitors, and bone marrow cellularity. Results: No significant differences were seen between the two treatment groups, whatever the parameter observed: time to leukocyte or platelet recovery and duration and severity of aplasia. Conclusion: Our results indicated that identical recovery kinetic was observed when irradiated animals are treated with G-CSF independently of the reinjection of ex vivo expanded autologous hematopoietic cells. Thus G-CSF injections might be chosen as a first-line therapeutic strategy in the treatment of accidental acute radiation victims

[en] The Eqo is a body scanner which allows images of the whole body to be obtained for safety purposes, without any exposure to ionising radiations, in a reliable and non-intrusive way in comparison with pat-down searching. Its technology is based on the use of so-called 'millimetre' waves. This expertise report is an answer to a public body request for an assessment of health risks related to the use of such a device. The authors first present the context of this investigation, and the Eqo gantry (operation, physical parameters, obtained image, control capacity, gantry usage). They report the assessment of electromagnetic field levels emitted by the Eqo gantry (measurement conditions, measurements), and the assessment of exposure to millimetre waves in relationship with the use of the Eqo gantry as far as passengers, airport workers and flight crews, operators, and testers are concerned. After a presentation of the potential health and biological effects of waves with a frequency higher than 1 GHz, the authors also report an assessment of health risks related to the use of Eqo (depth of penetration of waves into the body, issue of potential thermal and non thermal effects). Some recommendations are made