Autorité de sûreté nucléaire et de radioprotection

OBJECTIVES: Studies seeking direct estimates of the lung cancer risk associated with residential radon exposure lasting several decades have been conducted in many European countries. Individually these studies have not been large enough to assess moderate risks reliably. Therefore data from all 13 European studies of residential radon and lung cancer satisfying certain prespecified criteria have been brought together and analyzed. METHODS: Data were available for 7148 persons with lung cancer and 14,208 controls, all with individual smoking histories and residential radon histories determined by long-term radon gas measurements. RESULTS: The excess relative risk of lung cancer per 100 Bq/m3 increase in the observed radon concentration was 0.08 [95% confidence interval (95% CI) 0.03-0.16; P=0.0007] after control for confounding. The dose-response relationship was linear with no evidence of a threshold, and it remained significant when only persons with observed radon concentrations of <200 Bq/m3 were included. There was no evidence that the excess relative risk varied with age, sex, or smoking history. Removing the bias induced by random uncertainties related to radon exposure assessment increased the excess relative risk of lung cancer to 0.16 (95% CI 0.05-0.31) per 100 Bq/m3. With this correction, estimated risks at 0, 100, and 400 Bq/m3, relative to lifelong nonsmokers with no radon exposure, were 1.0, 1.2, and 1.6 for lifelong nonsmokers and 25.8, 29.9, and 42.3 for continuing smokers of 15-24 cigarettes/day. CONCLUSIONS: These data provide firm evidence that residential radon acts as a cause of lung cancer in the general population. They provide a solid basis for the formulation of policies with which to manage risk from radon and reduce deaths from the most common fatal cancer in Europe.

Vrijheid, M., Cardis, E., Ashmore, P., Auvinen, A., Gilbert, E., Habib, R. R., Malker, H., Muirhead, C. R., Richardson, D. B., Rogel, A., Schubauer-Berigan, M., Tardy, H. and Telle-Lamberton, M., for the 15-Country Study Group. Ionizing Radiation and Risk of Chronic Lymphocytic Leukemia in the 15-Country Study of Nuclear Industry Workers. Radiat. Res. 170, 661–665 (2008).In contrast to other types of leukemia, chronic lymphocytic leukemia (CLL) has long been regarded as non-radiogenic, i.e. not caused by ionizing radiation. However, the justification for this view has been challenged. We therefore report on the relationship between CLL mortality and external ionizing radiation dose within the 15-country nuclear workers cohort study. The analyses included, in seven countries with CLL deaths, a total of 295,963 workers with more than 4.5 million person-years of follow-up and an average cumulative bone marrow dose of 15 mSv; there were 65 CLL deaths in this cohort. The relative risk (RR) at an occupational dose of 100 mSv compared to 0 mSv was 0.84 (95% CI 0.39, 1.48) under the assumption of a 10-year exposure lag. Analyses of longer lag periods showed little variation in the RR, but they included very small numbers of cases with relatively high doses. In conclusion, the largest nuclear workers cohort study to date finds little evidence for an association between low doses of external ionizing radiation and CLL mortality. This study had little power due to low doses, short follow-up periods, and uncertainties in CLL ascertainment from death certificates; an extended follow-up of the cohorts is merited and would ideally include incident cancer cases.

Naturally occurring radioactive materials (NORM) contribute to the dose arising from radiation exposure for workers, public and non-human biota in different working and environmental conditions. Within the EURATOM Horizon 2020 RadoNorm project, work is ongoing to identify NORM exposure situations and scenarios in European countries and to collect qualitative and quantitative data of relevance for radiation protection. The data obtained will contribute to improved understanding of the extent of activities involving NORM, radionuclide behaviours and the associated radiation exposure, and will provide an insight into related scientific, practical and regulatory challenges. The development of a tiered methodology for identification of NORM exposure situations and complementary tools to support uniform data collection were the first activities in the mentioned project NORM work. While NORM identification methodology is given in Michalik et al., 2023, in this paper, the main details of tools for NORM data collection are presented and they are made publicly available. The tools are a series of NORM registers in Microsoft Excel form, that have been comprehensively designed to help (a) identify the main NORM issues of radiation protection concern at given exposure situations, (b) gain an overview of materials involved (i.e., raw materials, products, by-products, residues, effluents), c) collect qualitative and quantitative data on NORM, and (d) characterise multiple hazards exposure scenarios and make further steps towards development of an integrated risk and exposure dose assessment for workers, public and non-human biota. Furthermore, the NORM registers ensure standardised and unified characterisation of NORM situations in a manner that supports and complements the effective management and regulatory control of NORM processes, products and wastes, and related exposures to natural radiation worldwide.

In 2009, the European High Level and Expert Group identified key policy and scientific questions to be addressed through a strategic research agenda for low-dose radiation risk. This initiated the establishment of a European Research Platform, called MELODI (Multidisciplinary European Low Dose Research Initiative). In 2010, the DoReMi Network of Excellence was launched in the Euratom 7th Framework Programme. DoReMi has acted as an operational tool for the sustained development of the MELODI platform during its early years. A long-term Strategic Research Agenda for European low-dose radiation risk research has been developed by MELODI. Strategic planning of DoReMi research activities is carried out in close collaboration with MELODI. The research priorities for DoReMi are designed to focus on objectives that are achievable within the 6-y lifetime of the project and that are in areas where stimulus and support can help progress towards the longer-term strategic objectives.

Recommendations and requirements for the management of foodstuffs including drinking water and feedstuffs (but not other commodities) contaminated after a nuclear accident or a radiological event have been developed by international bodies such as Codex Alimentarius Commission or European Union as well as by individual countries. However, the experience from severe nuclear accidents (Chernobyl, Fukushima) and less serious radiological events, shows that the implementation of such systems (based on criteria expressed in activity concentration) seems to be not fully suitable to prevent several difficulties such as, for instance, stigmatization and even rejection attitudes from consumers or retailers (anticipating the fears of consumers). To further investigate the possible strategies and stakeholder expectations to deal with this sensitive issue, a study has been launched within the European research project PREPARE-WP3. The overall objective of this work, coordinated is to contribute to the development of strategies, guidance and tools for the management of the contaminated products, taking into account the views of producers, processing and retail industries and consumers. For this purpose, 10 stakeholder panels from different European countries have been set up. In addition, feedback experience from the management of contaminated goods following the Fukushima accident has been provided by Japanese stakeholders. This paper highlights the key topics tackled by the different European stakeholders' panels.

The EUropean RAdiation DOSimetry Group (EURADOS) initiated in 2005 the CONRAD Project, a Coordinated Network for Radiation Dosimetry funded by the European Commission (EC), within the 6th Framework Programme (FP). The main purpose of CONRAD is to generate a European Network in the field of Radiation Dosimetry and to promote both research activities and dissemination of knowledge. The objective of CONRAD Work Package 5 (WP5) is the coordination of research on assessment and evaluation of internal exposures. Nineteen institutes from 14 countries participate in this action. Some of the activities to be developed are continuations of former European projects supported by the EC in the 5th FP (OMINEX and IDEAS). Other tasks are linked with ICRP activities, and there are new actions never considered before. A collaboration is established with CONRAD Work Package 4, dealing with Computational Dosimetry, to organise an intercomparison on Monte Carlo modelling for in vivo measurements of (241)Am deposited in a knee phantom. Preliminary results associated with CONRAD WP5 tasks are presented here.

Probabilistic Fault Displacement Hazard Analysis (PFDHA) is pivotal in assessing the probability of surface fault displacement during seismic events, with critical implications for infrastructure systems like pipelines and lifelines. Recent earthquakes have underscored the importance of fault displacement as a cause of damage. This study aims to improve predictive models and regression analyses to assess the probability and expected amount of throw on distributed ruptures (DR) from normal and reverse earthquakes. The research leverages the SURE 2.0 database, which classifies ruptures into different ranks, including primary and various typologies of distributed ruptures. Logistic regression models are employed to assess the probability of DR occurrence, considering factors such as earthquake magnitude, proximity to the principal fault, faulting style, and DR location (hanging wall/footwall) as predictor variable. In addition, a fault displacement model is formulated to estimate the median throw on DRs based on these parameters and on a mean throw on the principal fault. The outcomes offer valuable insights into the characteristics and likelihood of DRs, carrying implications for PFDHA applications. The study introduces a decision-tree algorithm designed to assist PFDHA practitioners in selecting the most suitable approach based on the available geological knowledge. This study contributes to an improved understanding of fault displacement hazard analysis and provides a versatile framework for its application across diverse geological contexts.

The costs of monitoring for internal exposure in the workplace are usually significantly greater than the equivalent costs for external exposures. Therefore, there is a need to ensure that resources are employed with maximum effectiveness. The EC-funded OMINEX (optimisation of monitoring for internal exposure) project is developing methods for optimising the design and implementation of internal exposure monitoring programmes. Current monitoring programmes are being critically reviewed, the major sources of uncertainty in assessed internal dose investigated, and guidance formulated on factors such as programme design, choice of method/techniques, monitoring intervals, and monitoring frequency. OMINEX will promote a common, harmonised approach to the design and implementation of internal dose monitoring programmes throughout the EU.

Po is the dominant contributor irrespective of country-specific diets or restricted diet scenarios (fish-only, seaweed-only, etc.). Study results provide new guidance to improve the design, interpretation and communication of seafood ingestion dose assessments.

Abstract Fault displacement hazard poses significant risks to critical infrastructure such as buildings, roads, and pipelines. While some structures can tolerate a certain degree of surface displacement, others, such as buildings, are far more vulnerable. Probabilistic Fault Displacement Hazard Assessment (PFDHA) quantifies the probability of exceeding a certain level of displacement at a site due to surface‐rupturing earthquakes. A PFDHA model consists primarily of two components: the surface rupture probability and the fault displacement models (FDMs). FDMs distinguish between principal fault rupture and distributed rupture. Principal fault rupture occurs along the primary fault plane, where seismic energy is primarily released during an earthquake. In contrast, distributed rupture refers to all other tectonic surface ruptures occurring away from the principal fault. This differentiation was first introduced during the pioneering PFDHA study conducted for the Yucca Mountain nuclear waste repository (Nevada, USA) in the early 2000s. Since then, the methodology has been applied to various fault types, including strike‐slip and reverse faults. In recent years, the number of new models and the awareness of PFDHA has grown thanks to several international initiatives such as the worldwide and unified database of surface ruptures, the fault displacement hazard initiative, and the benchmark project led by the International Atomic Energy Agency. With growing interest and rapid advancements in this field, this article aims to provide a complete overview of all published models, discuss their applicability and limitations, standardize the terminology, and outline the necessary developments to guide future research.

Uranium (U) phosphate minerals are commonly found in U-contaminated environments, and understanding their origin and fate is essential for predicting U mobility at these sites. In this study, we used 238 U, 235 U, and 232 Th decay series to investigate U and radiogenic lead (Pb*) behavior within individual U-phosphate minerals in a wetland affected by past U-mining activities. Three groups of U-phosphates were identified using SEM-EDXS based on their U, Ca, and P contents: ningyoite-like minerals (CaU IV (PO 4 ) 2 ·2H 2 O), near-ideal Ca-autunites (Ca(U VI O 2 ) 2 (PO 4 ) 2 ·11H 2 O), and Ca-depleted autunite/chernikovite-like minerals ((H 3 O)(U VI O 2 )(PO 4 )·3H 2 O). NanoSIMS analysis of ( 230 Th/ 238 U) activity ratios revealed substantial U losses from the ningyoite-like minerals, particularly those located in the upstream vadose zone of the wetland, likely due to their oxidative dissolution under hydrological fluctuations. In contrast, the Ca-autunites and Ca-depleted autunite/chernikovite-like minerals exhibited ( 230 Th/ 238 U) signatures indicative of U accumulation. This behavior, more pronounced in the vadose zone, was interpreted as various stages of dissolution–precipitation that may have occurred upon early weathering of the U-ore and/or in the wetland. Finally, 206 Pb*/ 238 U ratios and Pb zoning within the U-grains revealed Pb losses, likely due to Pb diffusion in the mineral structure. Overall, this study demonstrates the relevance of NanoSIMS to investigate U and Pb mobility within microsized U-bearing minerals in contaminated environments.

Abstract. More than 23 million workers worldwide are occupationally exposed to ionizing radiation and all people in the world are exposed to environmental radiation. The mean exposure, that is the mean annual dose of per person, is dominated by medical applications and exposure to natural sources. Due to recent developments in healthcare, e.g. the increasing application of ionising radiation in medical imaging with relative high doses like CT, and modern high dose applications (for example CT angiography), the exposure due to medical application has risen. Additionally, the changes in living conditions increase the exposure to natural radioactivity also: More living time is spent in buildings or in an urban environment, which causes higher exposure to Naturally Occurring Radioactive Materials (NORM) in building materials and higher exposure to radon. The level of radon activity concentration in buildings is far higher than in the environment (outdoor). This effect is often amplified by modern energy-efficient buildings which reduce the air exchange and thus increase the radon indoor activity concentration. In summary both medical application of ionizing radiation and natural sources are responsible for the increase of the mean annual exposure of the population. The accurate measurement of radiation dose is key to ensuring safety but there are two challenges to be faced: First, new standards and reference fields are needed due to the rapid developments in medical imaging, radiotherapy and industrial applications. Second, direct communication channels are needed to ensure that information on best practice in measurements reaches effectively and quickly the people concerned. It is therefore necessary to allow for an international exchange of information on identified problems and solutions. Consequently, a European Metrology Network (EMN) for radiation protection under the roof of EURAMET is in the foundation phase. This network EMN for Radiation Protection is being prepared by the project EMPIR 19NET03 supportBSS. The project aims to prepare this EMN by addressing this issue through the identification of stakeholder research needs and by implementing a long-term ongoing dialogue between stakeholders and the metrology community. The EMN will serve as a unique point of contact to address all metrological needs related to radiation protection and it will relate to all environmental processes where ionising radiation and radionuclides are involved. A Strategic Research Agenda and two roadmaps are in development, covering the metrology needs of both the Euratom Treaty and the EU Council Directive 2013/59/EURATOM pinning down the basic safety standards for protection against the dangers arising from exposure to ionizing radiation. Furthermore, long-term knowledge sharing, and capacity building will be supported and a proposal for a sustainable joint European metrology infrastructure is under way. This will significantly strengthen the radiation protection metrology and support radiation protection measures. The final goal of the network project is a harmonised, sustainable, coordinated and smartly specialised infrastructure to underpin the current and future needs expressed in the European regulations for radiation protection.

• First earthquake-landslide-induced tsunami model, which included seismic waves. • Simulated seiche mechanism and homogenite formation in Lake Bourget. • Seismically induced seiche kept fine sediments in suspension, forming homogenite. • Numerical results validated against geological and historical records. • Framework to distinguish seismic vs. nonseismic sources of homogenite in lake deposits. Earthquakes leave distinct signatures on lake systems, including event deposits that serve as valuable paleoseismological archives. Among these deposits, homogenite layers are commonly associated with lake oscillations, i.e., seiches. Here, we investigate the seiche mechanism and the formation of a homogenite related sediment deposit within a lacustrine environment. This study focuses on the 1822 CE earthquake in the Western European Alps, which triggered subaqueous landslides in Lake Bourget (France). This event caused oscillations in the lake's water, which subsequently resulted in the formation of a homogenite layer in the deep basin. The underlying mechanism is resolved by presenting the first comprehensive numerical model via coupling of coseismic displacement, seismic wave propagation, and mass movement with the tsunami model. The numerical simulations show excellent agreement with the available geological and historical observations. The water disturbances caused by subaqueous landslides generated small tsunami waves with a maximum runup height of approximately 2.5 m. By analyzing the tsunami signals using Fourier spectral analysis and fast iterative filtering, we determined that seismic waves are the primary drivers of seiche, which excite the natural modes of Lake Bourget. Our numerical results confirm that the sediments found in the deep basin originated from one main subaqueous landslide and from tsunami erosion of littoral sands (backwash). However, the seismically induced seiche was solely responsible for keeping the fine-grained sediment cloud in suspension for several days and led to the formation of the homogenite layer (or seiche deposit) with typical grain orientation characteristics. The proposed numerical framework could also be effective in identifying whether landslides or delta collapses (linked to homogenite/megaturbidites) in closed lakes were triggered by seismic or nonseismic sources. This distinction is crucial for reconstructing the history of past earthquakes and associated hazards.

Biological effects induced by diverse types of ionizing radiation are known to show important variations. Nanodosimetry is suitable for studying the link between these variations and the patterns of radiation interactions within nanometer-scale volumes, using experimental techniques complemented by Monte Carlo track structure (MCTS) simulations. However, predicted nanodosimetric quantities differ among MCTS codes, primarily because each code employs distinct molecular-scale particle interaction models. This multi-code study examines these variations for low-energy electrons (20-10,000 eV), which play a critical role in energy deposition and biological effects by virtually all types of ionizing radiation. Specifically, the hypothesis tested in this work is that inter-code variability in nanodosimetry results is mainly caused by differences in assumptions regarding total interaction cross sections. Ionization cluster size distributions and derived nanodosimetric parameters were simulated with seven MCTS codes (PARTRAC, PHITS-TS, MCwater, PTra, and three Geant4-DNA options) in liquid water as a surrogate for biological tissue. Significant inter-code differences were observed, especially at the lowest energies. They were substantially reduced upon replacing the original cross sections in each code with a common, averaged dataset, created ad-hoc for this study and not based on theoretical assumptions. For example, for 50 eV electrons in 8 nm spheres, the variability in the predicted mean ionization numbers decreased from 23% to 5%, and in the probability of inducing two or more ionizations from 34% to 7% (relative standard deviations). This quantification demonstrates that total interaction cross sections are the primary source of uncertainty at low electron energies. A sensitivity test using DNA damage simulations with the PARTRAC code revealed that cross section variations notably affect biological outcome predictions. Replacing the code's original cross sections with the averaged ones increased the predicted double-strand break yield by up to 15%. These findings underscore the urgent need for improved characterization of low-energy electron interaction cross sections to reduce uncertainties in MCTS simulations and enhance mechanistic understanding of radiation-induced biological effects.

Lung cancer remains the leading cause of cancer mortality worldwide, with tobacco smoke and radon exposure being the primary risk factors. The interaction between these two factors has been described as sub-multiplicative, but a better understanding is needed of how they jointly contribute to lung carcinogenesis. In this context, a comprehensive analysis of current knowledge regarding the effects of radon and tobacco smoke on lung cancer was conducted using a computational approach. Information on this co-exposure was extracted and clustered from databases, particularly the literature, using the text mining tool AOP-helpFinder and other artificial intelligence (AI) resources. The collected information was then organized into Aggregate Exposure Pathway (AEP) and Adverse Outcome Pathways (AOP) models. AEPs and AOPs represent analytical concepts useful for assessing the potential risks associated with exposure to various stressors. AOPs provide a structured framework to organize knowledge of essential Key Events (KEs) from a Molecular Initiating Event (MIE) to an Adverse Outcome (AO) at an organism or population level, while AEPs model exposures from the initial source of the stressor to the internal exposure site within the target organism, situated upstream of the AOP. Combining these frameworks offered an integrated method for knowledge consolidation of radon and tobacco smoke, detailing the association from the environment to a mechanistic level, and highlighting specific differences between the two stressors in DNA damage, mutational profiles, and histological types. This approach also identified gaps in understanding joint exposure, particularly the lack of mechanistic studies on the precise role of certain KEs such as inflammation, as well as the need for studies that more closely replicate real-world exposure conditions. In conclusion, this study demonstrates the potential of AI and machine learning tools in developing alternative toxicological models. It highlights the complex interaction between radon and tobacco smoke and encourages collaboration among scientific communities to conduct future studies aiming to fully understand the mechanisms associated with this co-exposure.

This paper provides an overview of the Fault Displacement Hazard Initiative (FDHI). The FDHI is a community-based and multi-year research initiative with the goals of developing: (a) a comprehensive empirical database of surface fault displacement measurements and mapped ruptures, and (b) a suite of next-generation fault displacement predictive models. The database was developed by systematically collecting worldwide data from professional literature, followed by an extensive review and quality assurance process. The FDHI database contains 75 surface-rupturing earthquakes ranging from moment magnitude M 4.9 to 8.0 including data from strike-slip, reverse/reverse-oblique, and normal/normal-oblique faulting events. As part of the FDHI Program, employing the database, four new fault displacement models (FDMs) were developed. The FDMs predict principal or aggregate surface displacement, where aggregate is the combined displacement across principal and distributed ruptures. Two models were developed for all styles of faulting, while the other two are for reverse or strike-slip faulting. The new models include improved magnitude scaling and aleatory variability modeling. Compared with pre-existing models, average displacements in the new models are about 40% larger for M ~7, but smaller for lower and higher magnitudes. In addition, the new models predict significantly smaller displacement at low probability of exceedance. Besides the core FDHI tasks, in this article we also provide an overview of other parallel projects completed in coordination with the FDHI Program.

Laser-driven neutron generation is an attractive alternative to more established methods for compact, short-pulse-duration neutron sources with applications in medical science, material science and imaging. Despite extensive investigation of various techniques, achieving performance comparable to nuclear reactors or conventional accelerators remains challenging. In this work, we generate a stable, high-repetition-rate laser-driven neutron source reaching a record average flux of 7.8 × 107 n/sr/s, improving on other existing laser-based sources by more than one order of magnitude. Our approach is based on a two-step process where electrons are accelerated to relativistic energies via laser wakefield acceleration (LWFA), and subsequently generate neutrons through Bremsstrahlung emission followed by photonuclear reactions in a tungsten converter. Experimental results, supported by Monte Carlo simulations, show a neutron flux of 3.0 × 107 n/cm2/s near the target, on par with some compact accelerator-based neutron sources. Additionally, a direct comparison with the target-normal sheath acceleration (TNSA) pitcher-catcher scheme, performed on the same laser system, reveals a significantly higher total neutron yield of 3.9 × 108 neutrons per shot, outperforming the TNSA scheme by several orders of magnitude. These findings represent a significant advancement towards the development of practical laser-driven neutron sources and highlight the advantages of LWFA-based neutron generation for future applications. Current short-pulse-duration neutron sources suffer from a low repetition rate, hindering applications. Here, the authors demonstrate advancements of laser-wakefield based photoneutron generation at high repetition rates and conversion efficiencies, providing an alternative to traditional pitcher-catcher methods.

Manganese (Mn) removal in passive mine water treatment remains a challenge due to its slow oxidation kinetics, requiring specific biogeochemical conditions. Constructed wetlands are often the key functional units enabling Mn removal in full-scale passive treatment plants. This study examines the key biogeochemical factors influencing Mn removal in a full-scale passive mine water treatment plant located in Alès (South-East France). Over one year, monitoring of physicochemical parameters, microbial communities, and Mn speciation in solid phases was conducted every two months. Results highlight temporal variations in Mn removal efficiency, with two main mechanisms identified: (1) Mn carbonate (MnCO₃) precipitation, likely influenced by high carbonate concentrations in mine water, and (2) Mn oxide (δ-MnO₂) formation, mainly associated with reed rhizosphere, where it accumulates as mineral plaque. In mine water, Mn removal correlates with Fe particle concentrations, suggesting a catalytic effect, as well as with alkalinity and the abundance of microorganisms affiliated to Alteromonadaceae, suggesting a microbial influence. Mn removal appears to be primarily abiotic, driven by favourable pH and alkaline conditions that promote Mn carbonate precipitation, by autocatalytic oxidation reactions occurring on rhizosphere surfaces and by plant's design including surface area and hydrological conditions. Microbial communities may facilitate certain Mn removal processes depending on environmental conditions.

RadoNorm has come a long way since its inception, in addressing and managing risks for radon and NORM. The output of the project has been substantial in generating new findings and developing novel methodologies and tools. At the same time, the project has been translating its results into recommendations, which have been published as deliverables and scientific publications, and communicated to various stakeholders through its annual meetings, monthly webinars and the most recent RadoNorm Showcase Meeting held in Brussels. This review aims to produce a comprehensive summary of RadoNorm results and recommendations until this point (June 2025) as well as the recent discussions at the RadoNorm Showcase Meeting in March 2025, where the results were presented to a variety of stakeholders including the radiation research platforms. The results are presented under the themes of "health effects and risks", "exposure and mitigation" and "risk communication and societal aspects". RadoNorm has performed a comprehensive assessment of what has been achieved and what future questions have arisen from the latest results of the project, which are also elaborated upon herein and addressed as challenges for the European radiation research platforms to assimilate into their research portfolios.

Radiation therapy is a medical treatment that uses high doses of radiation to kill or damage cancer cells. It works by damaging the DNA within the cancer cells, ultimately causing cell death. Radiotherapy can be used as a primary treatment, adjuvant treatment in combination with surgery or chemotherapy or palliative treatment to relieve symptoms in advanced cancer stages. Radiation therapy is constantly improving in order to enhance the effect on cancer cells and reduce the side effects on healthy tissues. Our results clearly demonstrate that proton therapy and, even more, carbon ion therapy appear as promising alternatives to overcome the radioresistance of various tumors thanks to less dependency on oxygen and a better ability to kill cancer stem cells. Interestingly, hadrons also retain the advantages of radiosensitization approaches. These data confirm the great ability of hadrons to spare healthy tissue near the tumor via various mechanisms (reduced lymphopenia, bystander effect, etc.). Technology and machine improvements such as image-guided radiotherapy or particle therapies can improve treatment quality and efficacy (dose deposition and biological effect) in tumors while increasingly sparing healthy tissues. Radiation biology can help to understand how cancer cells resist radiation (hypoxia, DNA repair mechanisms, stem cell status, cell cycle position, etc.), how normal tissues may display sensitivity to radiation and how radiation effects can be increased with either radiosensitizers or accelerated particles. All these research topics are under investigation within the ARCHADE research community in France. By focusing on these areas, radiotherapy can become more effective, targeted and safe, enhancing the overall treatment experience and outcomes for cancer patients. Our goal is to provide biological evidence of the therapeutic advantages of hadrontherapy, according to the tumor characteristics. This article aims to give an updated view of our research in radiation biology within the frame of the French "ARCHADE association" and new perspectives on research and treatment with the C400 multi-ions accelerator prototype.