Les principales propriétés des dosimètres de rayonnement métal-oxyde-semi-conducteur (MOS) sont décrites. Nous présentons les résultats obtenus pour la sensibilité et la stabilité des dosimètres à oxyde de grille épais qui montrent que ce composant a des applications en dosimétrie des personnels et en médecine. Nous discuterons brièvement les améliorations possibles de la sensibilité.

This study aimed at investigating biological effects in Arabidopsis thalianaleaves and roots irradiated for 72 h with 3.5 Gy or 30 Gy of gamma radiation, and to unravel oxidative stress related responses to achieve a better understanding of the importance of the cellular redox balance as a modulator in gamma radiation stress. A. thaliana performs like a rather radioresistant plant species as no alterations on growth and only minor alterations in the nutrient profile were observed. Gamma irradiation did not seem to induce an NADPH mediated oxidative burst and lipid peroxidation appeared to be directly induced by ionizing radiation rather than mediated through LOX activity. As ionizing radiation can cause indirect damage via water radiolysis, H2O2 is hypothesized to be an important reactive oxygen species under radiation stress. Although most H2O2-scavenging enzymes remained unchanged, important alterations were observed for CAT1, CAT2 and CAT3expression.

An understanding of the dose-effect relationships of ionising radiation for nonhuman biota establishes important baselines for the radiological protection of ecosystems. We used standard laboratory tests to examine the dose-effect relationships of gamma radiation on the survival, growth and reproduction of the earthworm, Eisenia fetida (Oligochaeta). Adult E. fetida were acutely irradiated with increasing doses of gamma radiation, and the subsequent survival, growth in wet weight and number of offspring were examined. The 50% lethal dose (LD50) was 825 Gy, and the 10% and 50% effective doses (ED10 and ED50) for growth were 20.2 and 94.7 Gy, respectively. The ED10 and ED50 for reproduction were 3.3 and 11.1 Gy, respectively.

The radiation risk due to the exposure to natural radionuclides, especially to short-lived radon progeny, is a component of the radiation hazard, common in the natural environment and working environment. In Polish mining industry the radiation hazard, caused by natural radionuclides is the natural hazard. Radon in air and radium present in underground brines are sources of radiation hazards. Sediments precipitated out from such waters with enhanced radium content may cause the increase of external gamma radiation dose rate as well as internal contamination due to accidental ingestion or inhalation.

Investigation of that specific problem has been started in hard coal underground mines in Poland in early 1970’s. At the end of 1980’s first regulation was issued. Dose limits and requirements of the radiation monitoring have been established, internal regulations for monitoring and mitigation measures were developed on the basis of the Polish standard. The monitoring and prevention against natural radiation is obligatory in all Polish underground mines since 1989. This duty is strictly supervised by local offices of State Mining Authority in co-operation with other governmental agencies.

Après avoir rappelé les missions du Centre technique d'homologation de l'instrumentation de radioprotection (CTHIR) et le rôle du groupe de travail "Dosimetric individuelle des neutrons", l'article décrit la procédure d'évaluation des performances en prenant pour exemple les dosimètres neutrons à bulles, type BD 100 R-PND et BDT. Ces appareils portés sur le tronc assurent une dosimetric individuelle. Les grandeurs de référence auxquelles ces dosimètres sont soumis sont celles des rapports ICRU 39 et 47. Les conditions et les résultats des essais sont donnés. Il en ressort que ces appareils ont des performances suffisantes et conformes aux données du constructeur. Cependant, leur exploitation requiert des recommandations d'emploi.

The study of naturally-occurring radiation and its associated risk is one of the preoccupations of bodies responsible for radiation protection. Cosmic particle flux is significantly higher on board aircraft that at ground level. Furthermore, its intensity depends on solar activity and eruptions. Due to their professional activity, flight crews and frequent flyers may receive an annual dose of some millisieverts. This is why the European directive adopted in 1996 requires the aircraft operators to assess the dose and to inform their flight crews about the risk. The effective dose is to be estimated using various experimental and calculation means. In France, the computerized system for flight assessment of exposure to cosmic radiation in air transport (SIEVERT) is delivered to airlines for assisting them in the application of the European directive. This dose assessment tool was developed by the French General Directorate of Civil Aviation (DGAC) and partners: the Institute for Radiation Protection and Nuclear Safety (IRSN), the Paris Observatory and the French Institute for Polar Research - Paul-Emile Victor (IPEV). This professional service is available on an Internet server accessible to companies with a public section. The system provides doses that consider the routes flown by aircraft. Various results obtained are presented.

L'exposition aux rayonnements ionisants de la population française est due en majeure partie à la radioactivité naturelle (radon, irradiations externes d'origine tellurique et cosmique, ingestion d'eau et d'aliments). Dans un contexte épidémiologique, il est nécessaire d'estimer au mieux l'exposition de la population afin de pouvoir l'étudier conjointement à des indicateurs sanitaires. Dans cet objectif, des indicateurs d'exposition doivent être créés en prenant en compte les mesures environnementales et en contrôlant les facteurs de variabilité (caractéristiques de l'habitat, variations saisonnières, densité de population). La distribution des expositions doit également pouvoir être étudiée à différents niveaux géographiques (département, zone d'emploi). Le présent travail constitue une mise à jour de l'estimation de l'exposition de la population française à la radioactivité naturelle. Les indicateurs d'exposition au radon domestique reposent sur les concentrations mesurées, corrigées pour la saison et les caractéristiques d'habitat (variation départementale : 19–297 Bq/m3). Les indicateurs d'exposition au rayonnement gamma d'origine tellurique reposent sur les débits de dose mesurés, redressés sur le type d'habitat (22–95 nSv/h). L'exposition aux rayonnements cosmiques est évaluée à partir de l'altitude et pondérée sur la densité de population (0,27–0,38 mSv/an). La dose efficace annuelle due à ces trois composantes est estimée à 2,2 mSv.

Large amount of produced water, containing elevated levels of radionuclides (mainly 226Ra and 228Ra), is discharged to the sea~in connection with oil and gas production on the Norwegian continental shelf. The main objective of this project has been to establish radiological safe discharge limits for radium associated with other components in produced water. We present a summary of the methodology developed and the overall results obtained. Our results show that presence of added chemicals like scale inhibitors in the produced water have a marked influence on the speciation of radium, i.e. formation of radium and barium sulphates when produced water is mixed with seawater. Radium's behaviour in the sea has been modelled using the DREAM model. Also, we have showed that the bioavailability of radium may be increased due to presence of scale inhibitors. Juvenile cod has been exposed to radium through food and from water. The uptake in different organs, i.e. skin, gills, liver, blood, and kidneys, show large variability, but is modest in all organs.

The radioactivity concentrations of 226Ra, 232Th and 40Kwere measured using gamma-ray spectroscopy with NaI (Tl) detectors in four tantalitemining sites in the Oke-Ogun area, South-Western Nigeria. The measured values of theactivities of 40K, 226Ra and 232Th in the soil sampleswere found to lie in the ranges 123.7 ± 3.8 – 1372.3 ± 8.6, 16.8 ± 1.6 – 71.1 ± 2.53 and3.0 ± 0.7 – 31.9 ± 1.0 Bq kg–1, respectively. These samples were also found to have radiumequivalent activity in the range 74.2–121.0 Bq kg-1. Values of 0.2–0.3 for the externaland 0.3–0.4 for the internal hazard indices were estimated for the samples and the annualeffective dose varied from 70.3 ± 13.5 to 100.8 ± 42.8 µSv with a mean of 87.5 ± 18.6 µSvy–1. The annual effective dose is higher than the world average.

We report detailed depth profiles of the particle-reactive radionuclides 234Th (24.1 days) and 7Be (53.3 days) in sediment cores collected at different seasons in the Thau Lagoon, located in the south of France. Two sites with contrasting characteristics were selected: C4 in the middle of the lagoon and C5 nearby oyster farming. Both sites were visited six times between December 2001 and May 2003. 234Th in excess (234Th$_{\mathrm{xs}}$; i.e. supplied to sediment by settling particles) and 7Be both show seasonal variations in activities and in penetration within sediment. With their very short half-lives and moderate sedimentation rates at both sites (around 0.1 - 0.3 cm per year), 234Th$_{\mathrm{xs}}$ and 7Be should be present only at the water-sediment interface. However all the profiles show penetration of both short-lived radionuclides to variable depths, from 1 up to 8 cm, that indicates efficient biological mixing of upper sediments. Such a mixing is usually described as a biodiffusive transport defined by bioturbation coefficient (D$_{\mathrm{b}}$). The simplest way to calculate D$_{\mathrm{b}}$ from radionuclide profiles is to assume steady-state within the mixed layer. For site C4, steady-state bioturbation rates (D$_{\mathrm{b}}$-SS) range between 1 and 12 cm2 yr-1, with a weak seasonal signal. The mixing of surface sediments at site C5 presents a greater range (1 - 31 cm2 yr-1) with the highest values observed in summer. Radionuclide fluxes at the water-sediment interface show too seasonal variations, particularly marked at site C5 in relation with its position. Such a time-series of short radionuclides at the water-sediment is most unusual. It provides the opportunity to develop a non-steady state modelling in order to test the significance of bioturbation rates based on steady state assumption. These tests allow to figure out how variations (seasonal, episodic) of radionuclide fluxes could induce errors on D$_{\mathrm{b}}$-SS determinations.

Results of radioecological investigations of rodents having different ecological specialization – wood and field mice, northern red-backed voles and mole-voles to acute (laboratory experiment) and chronic (long-term inhabiting the East Ural Radioactive Trace – EURT) irradiation are summarized. These species are greatly distinguished by a way of life, a migratory activity, an average life span etc. Numerous immunological, hematological and cytogenetical disturbances were found in more radioresistant wood and field mice and northern red-backed voles inhabiting the EURT zone (density of soil pollution by 90Sr-18.5 MBq/m2=500 Ci/km2) as compared with the reference samples. On the contrary there were no pathological shifts in more radiosensitive mole-voles from the more radioactively contaminated site (90Sr-37 MBq/m2=1000 Ci/km2. The absorbed dozes during the life for the mole-voles from the EURT zone were significantly higher (in 30 times) than these ones for mice and voles. These data testify about the possibility of radioadaptation in a series of generations in mole-voles that developed due to their ecophysiological features and isolation of settlement in the radiocontaminated zone. Mice and voles form a flowing population and slip off the prolonged influence of a damaging factor, this circumstance prevents the development of radioadaptation.

Saline waters from underground coal mines in Poland often contain natural radioactive isotopes, mainly 226Ra from the uranium decay series and 228Ra from the thorium series. More than 70% of the total amount of radium remains underground as radioactive deposits due to spontaneous co-precipitation or water treatment technologies, but several tens of MBq of 226Ra and even higher activity of 228Ra are released daily into the rivers along with the other mine effluents from all Polish coal mines. Mine waters can have a severe impact on the natural environment, mainly due to its salinity. Additionally high levels of radium concentration in river waters, bottom sediments and vegetation were also observed. Sometimes radium concentrations in rivers exceeded 0.7 kBq/m3, which was the permitted level for waste waters under Polish law. The investigations described here were carried out for all coal mines and on this basis the total radium balance in effluents has been calculated. Measurements in the vicinity of mine settling ponds and in rivers have given us an opportunity to study radium behaviour in river waters and to assess the degree of contamination. For removal of radium from saline waters a method of purification has been developed and implemented in full technical scale in two of Polish coal mines. The purification station in Piast Colliery was unique, the first underground installation for the removal of radium isotopes from saline waters. Very good results have been achieved – approximately 6 m3/min of radium-bearing waters were treated there, more than 100 MBq of 226Ra and 228Ra remained underground each day. Purification has been started in 1999, therefore a lot of experiences have been gathered during this period. Since year 2006, a new purification station is working in another colliery, Ziemowit, at the level – 650 meters. Barium chloride is used as a cleaning agent, and amount of water to be purified is reaching 9 m3/min. Technical measures such as inducing the precipitation of radium in gobs, decreasing the amount of meteoric inflow water into underground workings etc., have been undertaken in several coal mines, and as a result of these measures the total amount of radium released to the surface waters is much has diminished significantly during the last 15 years.

For targeted radionuclide therapies, treatment planning usually consists of theadministration of standard activities without accounting for the patient-specific activitydistribution, pharmacokinetics and dosimetry to organs at risk. The OEDIPE software is auser-friendly interface which has an automation level suitable for performing personalizedMonte Carlo 3D dosimetry for diagnostic and therapeutic radionuclide administrations. Meanabsorbed doses to regions of interest (ROIs), isodose curves superimposed on apersonalized anatomical model of the patient and dose-volume histograms can be extractedfrom the absorbed dose 3D distribution. Moreover, to account for the differences inradiosensitivity between tumoral and healthy tissues, additional functionalities have beenimplemented to calculate the 3D distribution of the biologically effective dose (BED),mean BEDs to ROIs, isoBED curves and BED-volume histograms along with the EquivalentUniform Biologically Effective Dose (EUD) to ROIs. Finally, optimization tools areavailable for treatment planning optimization using either the absorbed dose or BEDdistributions. These tools enable one to calculate the maximal injectable activity whichmeets tolerance criteria to organs at risk for a chosen fractionation protocol. This paperdescribes the functionalities available in the latest version of the OEDIPE software toperform personalized Monte Carlo dosimetry and treatment planning optimization in targetedradionuclide therapies.

Environmental radiation levels are modified in regions where the oil industrial activity is more aggressive, such as in the Zulia State and the Orinoco's Oil Belt. In these regions Venezuela is producing 1750 thousand barrels of oil from the near-to-the-surface or deep oil drilling, being its 2003 total OPEC market share 2932 thousand barrels of oil per day [1]. Petroleum constitutes an important source of energy and as the majority of natural sources it contains radionuclides and their disintegration products. The combustion of oil concentrates in the ashes those radioelements, which later enters the environment by different pathways producing adverse effects on the quality of man life. The concentration of radioelements varies greatly between oil fields, and then still requiring local survey studies in this area. Moreover due to the recent national interest in recycling processes, it becomes important to take care in the selection of materials that may contain by-products of industrial origin. In fact the oil ashes and other mining by-products are employable in the building industry. The concentration of radioactivity and heavy metals in crude oil, fuel oil N$^{\circ}$ 6 and the ashes from power plants were determined. The analysis includes the two major thermoelectric power plants in Venezuela, Ricardo Zuluaga on the northern seaside of Caracas and Planta Centro on the littoral of Carabobo State. The study covers different samples: fuel oil N° 6, heavy and medium petroleum as well as fuel Oil N°6 ashes. Gamma spectrometry was used for measuring 226Ra, 214Pb, 214Bi, 228Ac, 212Pb, 212Bi, 208Tl and 40K, and heavy metallic cations were determined by ICP-MS, which also allows the direct determination of 232Th and 238U. In this material (oil ashes) the total activity concentration is above 300 Bq.kg-1. Some criteria from the literature have been compared and used to investigate the applicability of oil ashes as an additive for building materials. The combustion concentrate also heavy metal cations, as is the case of Pb, Ni, Mn, V, Zn among others. The found high metal concentrations can represent an important environmental risk since the high amount of sulfates in the Venezuelan oil and ashes contributes to their dissolution and bioavailability.

Le concept de niveau de référence diagnostique (NRD) introduit dans la CIPR 73 “ Protection et sûreté radiologique en médecine ” est spécifique aux expositions médicales. Dans ce domaine, en effet, l'un des trois principes de la radioprotection, la limitation réglementaire des doses, ne peut s'appliquer comme pour les expositions professionnelles et publiques. Les niveaux de référence ne sont ni des “ limites de dose ”, ni des “ doses optimales ”, ce sont des outils pour l'optimisation. Ils sont établis pour des examens standardisés et des patients types, et ne devraient pas être dépassés sans justification, pour des procédures courantes. Les NRD sont des indicateurs dosimétriques de la qualité des pratiques destinés à identifier les situations nécessitant une action corrective. Dans le cadre de la transposition de la directive 97/43 Euratom, le directeur général de la santé a confié à l'OPRI, en 1999, une mission spécifique pour la mise en œuvre des niveaux de référence, en concertation avec les sociétés savantes et professionnelles concernées. La méthode recommandée par la Commission européenne, dite du 75e percentile, basée sur le traitement statistique d'enquêtes dosimétriques représentatives, est à l'heure actuelle inopérante en France en raison de l'insuffisance des données. Une démarche spécifique a donc été définie. Dans un premier temps, un travail de standardisation des procédures radiologiques avec adoption des niveaux de référence européens comme point de départ a été effectué. Dans un second temps, une campagne nationale de mesures de doses co-pilotée par l'OPRI (actuellement l'IRSN et la DGSNR), la SFR et la SFPM est en cours de réalisation pour établir des NRD français.

The gamma-ray exposure build-up factors of raw materialsof bricks (soils and fly-ashes) in the state of Punjab were investigatedfor the photon energy range 0.015 to 15 MeV up to 40 mfp penetrationdepth by the geometrical progression (GP) method. Appreciable variationsin the exposure build-up factor (EBF) are noted for the raw materials.The EBFs of the raw materials of bricks change depending on thephoton energy, penetration depth and chemical composition. The build-up factorsare low at low and high photon energies, whereas they are very highin the medium-energy region. The peak energy of the EBF for soilsis 0.3 MeV and 0.2 MeV for fly ashes. The EBFs of the raw materialsof bricks are also compared with those of bricks of red mud andcommon brick materials. Common bricks were found to have the lowestgamma-ray EBF. This study should be useful for emergency preparednessplanning and emergency dose estimation for future planned nuclearpower plants in the state of Punjab.

Radionuclides released to the environment may be present in different physico-chemical forms, ranging from ionic species to colloids, particles and fragments. Following releases during nuclear events such as nuclear weapon tests or use of depleted uranium munitions, and from nuclear accidents associated with explosions or fires, radionuclides such as uranium and plutonium are predominantly present as particles, mainly fuel particles. Similarly, radioactive particles are present in effluents from reprocessing facilities, and radioactive particles are observed in sediments in the close vicinity of radioactive waste dumped at sea. Thus, releases of radioactive particles occur far more often than earlier anticipated. Soils and sediments can act as a sink for colloids, particles and fragments, while contaminated soils and sediments may also act as a potential diffuse source, depending on particle characteristics and processes influencing particle weathering and remobilisation of associated radionuclides. To assess long-term impact from radioactive particle contamination, information on the source term is essential, i.e. activity concentrations and isotopic ratios as well as the particle size distribution, crystallographic structures and oxidation states influencing particle weathering rates and the subsequent mobilisation and biological uptake of associated radionuclides. The activity concentrations and the isotopic ratios will be source dependant, while particle characteristics will also reflect the release scenario, dispersion processes and deposition conditions. The present paper will summarise information on various nuclear sources summarise having released radioactive particles in the past


The Rhône watershed extends over almost one hundred thousands square kilometers, i.e. one fifth of the metropolitan French territory. The Rhône is the major River entering the Western Mediterranean Sea as it generates the main source of sediments and freshwater (50%) to the sea, with an average water discharge of 1700 m3 s-1. The River input affects primary production significantly in the north-western Mediterranean area and plays a leading role on the marine ecosystem functioning in the whole Gulf of Lion. Almost twenty nuclear reactors are situated along the Rhône valley, representing Europe’s biggest concentration of nuclear power plants. Down flow all these installations the spent fuel reprocessing plant of Marcoule released over many years most of the liquid radioactive wastes including plutonium isotopes in the Rhône river. Artificial radionuclides also originate from the weathering of the catchment basin labeled by both the global and the Chernobyl accident atmospheric fallout. These radioactive inputs have led to a permanent contamination of the Rhône river waters. Long-term chronological series of artificial radionuclide activities within the waters at the lower reaches of the Rhône river were acquired from 1979 to 2002. These data give evidence for various radioecological responses of the aquatic system over years. Based on these observations several major radioecological sensitivity factors for river waters are identified.

This paper shows that natural materials such as barks can successfully replace syntheticresins for industrial purposes. Evaluated in batch conditions, biosorption of uranium onsuitably prepared Douglas fir barks took place in less than 10 min and appeared to beoptimum at pH>4. The biosorption process of uranium (uranyl formUO\hbox{$_{\mathrm{\mathbf{2}}}^{\mathrm{\mathbf{2+}}}$}$\begin{array}{}{2}\mathrm{+}\\ {2}\end{array}$)was characterized in the optimal physico-chemical conditions and could be mathematicallymodeled as a Langmuir isotherm. With a maximum uranium specific uptakeqmaxvalue of 1.16 meq.g-1 (138mgU.g-1) it was found that the sorption capability of Douglas fir barks wasat least five times higher for uranium than for other heavy metals such as lead.Adsorption of uranium contained in water leached from a former uranium mine was thenmonitored over a one-month period in a laboratory-scale chromatography column. Thefixation capacity remained fairly constant throughout the whole testing period. Waterradioactivity decreased from 1500 mBq.L-1 (0.12 mgU.L-1) to <5 mBq.L-1(0.4 μ gU.L-1) at the columnexit. This technology was successfully transferred and tested through a pilot projectunder industrial conditions with the support of AREVA NC.

In surface soils, the native physical and chemical properties of the abiotic components control most of the sorption-desorption processes. Moreover, micro-organisms may significantly modify the speciation of trace elements and/or radionuclides and subsequently determine their fate, to a large extent. Micro-organisms, mainly bacteria and fungi, develop many strategies that may affect indirectly or directly the behaviour of trace elements. Due to their activity, changes in the pore-water composition, e.g. pH, redox-potential, may occur in relation with organic acid production or solid phase alteration, reduction or oxidation of metallic oxi-hydroxides, and mineralization of organo-metallic complexes. Micro-organisms may also directly modify the speciation of radionuclides as a result of bio-accumulation in living cells, biosorption on cellular components, direct reduction or oxidation, biomethylation, etc. Each one of these microbial processes may either increase or decrease radionuclide mobility, depending on the element, the soil reactivity and the environmental conditions. The resulting effect of these processes is still poorly known. This literature review intends to present a comprehensive overview of the role of micro-organisms on radionuclide mobility. It aims at classifying these elements, regarding to their potential sensitivity to these microbial processes. It summarizes the theoretical effect of these mechanisms, resulting in a potential increase or decrease of the solid-liquid distribution. The environmental significance of such processes for various biogeochemical radionuclides cycles still remains to be confirmed by experiments. (This study is part of a research program supported by Andra).