Indoor radon concentrations were measured in four well-known spas of Tunisia usingnuclear track detectors. The radon concentrations in these spas were found to be in therange of 19 - 870 Bq.m-3. The equilibrium factor F between radon and itsprogeny was found to vary in the range of 0.2 - 0.5, depending upon the ventilation rateswithin the buildings of the spas. Using the exposure-dose conversion factor, the effectivedoses to patients and workers were estimated and the dose was found to vary in the range3.7 × 10-3 - 12.5 × 10-3 mSv.y-1 and 0.45 - 1.5 mSv.y-1for patients and workers, respectively. These values are well inside the limit recommendedfor the annual dose limit of 20 mSv.y-1 for an occupational worker. The radiumcontent in the groundwater of all four spas was measured and the results showed nocorrelation between the 226Ra concentration in water and radon concentration inindoor air of the investigated spas.

The concentrations of natural radionuclides in 6 differentcolors of volcanic tuff stones which are derived from the Cappadociaregion in Turkey were determined using gamma-ray spectroscopy witha HPGe detector, and the mineralogical composition and formula ofstones were determined by an X-ray powder diffractometer. The averageactivity concentrations of 238U, 232Th and 40Kare 50.7, 58.6 and 717.6 Bq.kg–1, which are higher thanthe world averages of 35, 30 and 400 Bq.kg–1, respectively.The radium equivalent activities (Raeq), external hazardindex (Hex), and internal hazard (Hin) associatedwith the natural radionuclides, alpha (Iα) and gammaindices (Iγ) were calculated to assess the radiationhazard of the natural radioactivity in the volcanic tuff stones.The average indoor annual effective dose equivalent is 0.1 mSv.All values of the indoor effective dose are lower than the exemptiondose value of 0.3 mSv. The calculated radium equivalent activityvalues vary from 60.31 Bq.kg–1 to 281.32 Bq.kg–1 witha mean of 189.78 Bq.kg–1. All values of radium equivalentactivity are lower than the world average. The average indoor absorbeddose rate (Din) for volcanic tuff stones, calculatedto be 21.18 nGy.h–1, is lower than the world averageof 84 nGy.h–1.

Predictions of the effects of agricultural countermeasures are an important part of thedecision-making process following an accidental release of radioactive material into theenvironment. A new model has been developed for this purpose and integrated into the EUdecision support systems RODOS and ARGOS. The model is based on the existing food chainmodel of RODOS and the previous model for simulating agricultural countermeasures inRODOS. The characteristics of the countermeasures and the supporting databases have beenderived from the compendia and handbooks developed within the EURANOS project. A widerange of potentially practicable countermeasures is considered on timescales from a day tomany years, and endpoints related to their imposition are calculated such that theeconomic and health impacts can be evaluated. This paper outlines the countermeasuresmethodology adopted and the databases used and discusses their applicability.

Les techniques de spectroscopie laser sont de plus en plus employées pour l'analyse élémentaire à bas niveau et la spéciation des actinides et autres radionucléidesd'intérêt. A partir d'une recherche bibliographique et des expériences développées au sein du Laboratoire de spectroscopie laser analytique, le principe,les performances, les applications ainsi que les avantages et les inconvénients de ces différentes techniques laser sont présentés, une comparaison est effectuée avec une autre technique (non-laser) analytique performante, latorche à plasma – spectrométrie de masse. Les différentes techniques laser présentées sont en spectroscopie moléculaire : la lentille thermique, la spectrofluorimétrielaser à résolution temporelle, la fluorescence induite par laser de l'iode, et en spectroscopie atomique : la spectroscopie optogalvanique, la fluorescence induite par laser en four de graphite, la fluorescence induite par laser dans unetorche à plasma, la spectroscopie d'ionisation résonnante colinéaire et l'ionisation laser couplée à la spectrométrie de masse. Les principaux avantages des techniques de spectroscopie laser sont l'absence de préparation d'échantillon, la rapidité, la sélectivité, la sensibilité ainsi que la possibilité de pouvoir effectuer des analyses à distance via fibre optique.

The extent of radiocaesium in soil is very important to appreciate the risk of its recycling by the vegetation and thus the risk of food chain contamination. An intrinsic soil parameter, the radiocaesium interception potential (RIP), could be used to measure this retention. In this study, we tested the possibility to predict the RIP starting from a simple acid extraction in widely different soils coming from the whole world and pertaining to various soil reference groups of the WRB/FAO world soil classification. Our results show that a simple acid extraction could be used as an operational test to estimate the RIP whatever the soil type.

Long-term observations on the effects of a fertilization treatment on 137Cs concentrations in forest vegetation are scarce. Needles of Scots pine were used as biological indicators of radionuclide uptake of trees. The fertilization experiments are located in western Finland in an area where radioactive contamination from the Chernobyl accident in 1986 was relatively high (22–75 kBq m−2) compared to other parts of Finland. Fertilization treatments included different combinations of major nutrients, i.e. nitrogen, phosphorus, potassium and calcium. Needle 137Cs concentrations of Scots pine were analyzed during 1991–2006. The effect of fertilization on 137Cs concentration was tested 5 to 20 years after radioactive contamination from the Chernobyl accident in 1986. Fertilization clearly decreased 137Cs concentration in Scots pine needles 1–21 growing seasons after application. Single K fertilization decreased significantly 137Cs concentration 21 growing seasons after radioactive deposition on a drained mire. Mineral nutrients (application of commercial fertilizer or wood ash) can well be recommended for remediation of forests contaminated by accidental radionuclide deposition. The site conditions need to be taken into account in planning of remediation.

Bitumen samples and soil samples around a bituminous deposit in Ondo State, Nigeria, wereanalysed for 40K, 226Ra and 232Th employing gamma-rayspectrometry. The activity concentrations of 40K, 226Ra and232Th in soil varied from (45.2 ± 5.3) to (484.2 ± 25.9), BDL (belowdetectable limit) to (27.7 ± 2.1) and (22.8 ± 2.7) to (62.4 ± 6.8) Bq.kg-1,respectively. The corresponding mean values were (240.2 ± 133.5), (13.3 ± 8.0) and (40.0 ±10.2) Bq.kg-1, respectively. The mean activity concentrations of theradionuclides in the bitumen were (58.4 ± 36.4), (16.1 ± 13.3) and (32.5 ± 13.1)Bq.kg-1, respectively, for 40K, 226Ra and232Th. The mean absorbed dose and effective dose for the soil samples were(41.5 ± 8.9) nGy.h-1 and (50.7 ± 10.9) μSv.y-1, respectively, whilethose of the bitumen samples were (29.5 ± 15.6) nGy.h-1 and (36.1 ± 19.1)μSv.y-1, respectively. For radiological hazard assessment, the radiumequivalent activity and the external hazard index were determined. The values of theradium equivalent activity and external hazard index obtained for the soil and bitumensamples were lower than the recommended limit.

In the frame of the IRSN Chernobyl Pilot Site Project, a waste trench containing hot particles was instrumented to study the fate of radioactive pollutants. Results have shown the formation of a 90Sr plume in the downstream aquifer, mainly present in the Aeolian layer after 15 years. Laboratories experiments were performed to analyse the transport of 90Sr and 137Cs in the Aeolian sand in both saturated and unsaturated conditions. Batch experiments were performed to study the chemical equilibrium state of the soil/solution system under static conditions. Stirred flow-through reactor experiments were performed to study the kinetics and reversibility of sorption reactions at the surface of solid particles under dynamic conditions. Column experiments in the structured porous media were also performed in saturated and unsaturated flow conditions. Experimental data pointed out a non-linear, instantaneous and reversible sorption process of 90Sr. 137Cs exhibits a non-linear behaviour with a partial irreversible sorption process. A suitable cation-exchange model was used to describe the solute/soil reactions. The former model was coupled with transport models to describe behaviour of 90Sr and 137Cs in both saturated and unsaturated steady flow conditions. Main transport parameters were identified and discussed. An effective simple Kd type approach to describe radionuclides transport properties under unsaturated conditions was evaluated

Radionuclides find their way into the water resources at sites in the vicinity of nuclearfacilities involved in mining, milling, ore separation, purification, etc. The presentedstudy delineates the distribution of radionuclides {Ra and U(nat)} in groundwatersexisting in the vicinity of two proposed uranium mine sites and evaluates their ingestiondose through the intake of drinking water. The study reveals that the U(nat) concentrationin groundwater varied from <0.5 to 11.2μg.l-1 in the Bagjata mining area and from<0.5 to 27.5 μg.l-1 in theBanduhurang mining area, while 226Ra was found in the range of <3.5 to 206 mBq.l-1 and<3.5 to 82 mBq.l-1, respectively, for both areas.Seasonal variation and distribution of radionuclides in the study area did not show anydefinite pattern. A strong positive correlation of U(nat) in groundwater with pH andnegative correlation of 226Ra with pH is shown in the study. The ingestion doseto the public through intake of drinking water is estimated as 9.43μSv.y-1 for Bagjata and 6.28μSv.y-1 for Banduhurang, which is much lower than thereference limit (100 μSv.y-1) given by the WHO.

The sedimentary sandstone and clay sequence of the Miocene Kamlial and Murree Formationsis exposed in the sub-Himalayas of the Dhirkot area, State of Azad Jammu and Kashmir,Pakistan. The indoor radon and outdoor gamma dose rates were measured from dwellings andbasement sandstone and clay rocks, respectively. The radon concentration in dwellings was36 ± 14 Bq.m-3 to 195 ± 27 Bq.m-3, with an average of 121 ± 26Bq.m-3. The average radon concentration in pucka, semi-kucha and kucha houseswas 124 ± 25 Bq.m-3, 143 ± 25 Bq.m-3 and 136 ± 26Bq.m-3, respectively. The outdoor gamma dose rates for the basementsandstones and clays of the Murree Formation and Kamlial Formation were 74.0 ± 1.4–113.1± 2.4 nGy/h and 69.6 ± 2.2–108.8 ± 1.4 nGy/h, respectively. The average gamma doserates for the Murree and Kamlial Formations were 91.3 ± 14.3 nGy/h. The gamma dose rateis maximum (113.1 ± 2.4 nGy/h) and minimum (69.6 ± 2.2 nGy/h) at higher (5 539 feet)and lower (4 493 feet) altitudes, respectively. The overall causes for the increase inaverage radon concentration in dwellings of the Dhirkot area were poor ventilation, oldhouses, humidity and temperature, cracks in houses, geology, and aggregates. The gammadose rate variation depends on sandstone and clay lithologies, altitude and radionuclidecontributions. This study shows that the average radon (121 ± 26 Bq.m-3)concentration for the inhabitants of the Dhirkot area was within the accepted safe healthlimit (200 Bq.m-3, ICRP, 1993; UNSCEAR, 1993).

Dans le cadre des travaux de transposition en droit français de la directive 97/43 Euratom relative à la radioprotection des patients, une campagne nationale de dosimétrie en radiodiagnostic s’est déroulée entre avril 2001 et février 2003, à l’initiative conjointe des sociétés savantes et professionnelles, de la Direction générale de la Sûreté nucléaire et de la radioprotection (DGSNR) et de l’Institut de radioprotection et de sûreté nucléaire (IRSN). Son objectif était d’associer des niveaux de doses aux procédures radiologiques standardisées, élaborées dans une étape précédente par la Société française de radiologie, et d’engager une première étude pour la détermination de niveaux de référence diagnostiques (NRD) français. Sur la base de protocoles de mesures et de fiches d’informations établis par l’IRSN et la Société française de physique médicale, la campagne a reposé sur des équipes pluridisciplinaires (radiologue, physicien, technicien), dans 24 services de radiologie volontaires. Son organisation pratique, la centralisation des données et le traitement des résultats ont été assurés par l’IRSN. Pour les 8 examens sélectionnés (4 en radiologie classique et 4 en scanographie), dans chaque service, 20 sujets d’âge adulte et de morphologie moyenne devaient faire l’objet d’une dosimétrie. En radiologie classique, la dose à l’entrée a été mesurée par dosimètres thermoluminescents placés à la peau, pour 1231 patients. En scanographie l’indice de dose de scanographie pondéré et le produit dose × longueur ont été déterminés pour 667 patients à partir des paramètres de l’examen et des données de base du scanner. Pour chaque type d’examen les valeurs moyennes de chacune de ces grandeurs ainsi que celles du 75e percentile ont été calculées. Pour la grande majorité des examens et des centres ayant participé à l’étude, il apparaît que ces valeurs se situent en dessous des NRD proposés par la Commission européenne en 1996. Ces résultats, analysés en fonction des facteurs d’influence sur la dose et des limites méthodologiques de l’étude (volontariat des services participant), prouvent la faisabilité et le grand intérêt d’une campagne nationale de mesures de doses en radiologie, à plus grande échelle, qui permettrait d’établir des NRD spécifiques à la pratique française, de prévoir leur révision périodique et de définir les démarches d’optimisation appropriées.

During the last decade or so, the topic of environmental protection from ionising radiation has become a major issue within the field of radiological protection. The change of focus from a purely anthropocentric approach has led to the development and availability of bespoke methodologies for the assessment of impacts on wildlife from radioactive contaminants. The application of such assessment methodologies to actual situations, however, remains relatively limited. This paper describes the implementation of the ERICA Integrated Approach and associated tools to areas exhibiting elevated levels of NORM at Søve in Norway and Wislinka and Kaniow in Poland. In all cases, lichen and bryophytes were found to be the most exposed organisms and tree and large mammals the least exposed. With the exception of Kaniow, Ra-226 is the radionuclide that dominates in terms of its contribution to the total dose rates for all animal organism groups. For plants, Th-228 and Po-210 are dominant contributors. While Th-228 is the primary contributor to external dose rates for all species at Søve and Wislinka, Ra-226 is the primary contributor to internal dose rates in most cases for all sites.

In the last few years there has been significant development of radiation therapy (RT)equipment with advanced imaging and delivery techniques, as well as treatment planningsystems. From this perspective, proactive approaches for risk assessment were identifiedas a powerful tool in modern radiation oncology. A multidisciplinary working group (WG)has been established in the framework of the Italian association for medical physics(AIFM) to promote the use of prospective approaches in the radiotherapy scientificcommunity. This paper describes the main actions carried out by the WG in order to collectinformation about the engagement of Italian medical physicists in the risk managementprocess, in reporting possible incidents in RT and in the procedures of collecting andanalysing near misses. In particular, the main scope of the study was to evaluate theactual level of experience in use of proactive risk analysis tools in modern RT by medicalphysicists. Finally, the measures implemented by the WG in order to promote the use ofsuch approaches, and consequently to contribute to enhancing safety and radiationprotection culture in radiation oncology are described.

Dans le domaine des eaux douces, un très grand nombre de travaux ont été réalisés pour caractériser les échanges des radionucléides entre phases solide et liquide constituant les compartimentsphysiques des écosystèmes naturels. Ces échanges dépendent des conditions physiques, chimiques et biologiques régnant dans le milieu. Généralement le concept de Kd ou coefficient dedistribution, est utilisé pour quantifier la répartition du radionucléide entre phase dissoute et particulaire. Les principaux paramètres environnementaux influençant la valeur du Kd sont les suivants : temps de contact, concentration en matières en suspension, nature et granulométrie de la phase solide (plus particulièrement pour le césium, le cobalt, le manganèse, l'argent, l'iode),concentration en isotopes stables des phases solide et liquide (césium, cobalt, manganèse, argent), composition minérale de la phase liquide (césium), pH de l'eau (cobalt, manganèse, argent),conditions d'oxydoréduction des deux phases (césium, manganèse), composés organiques dissous (cobalt, antimoine, iode). Ainsi, en liaison avec l'influence de ces divers paramètres, la gammede variation du Kd est très vaste pour chaque radionucléide. Cette gamme peut être réduite, pour un écosytème à un moment donné de son cycle hydrologique, si les valeurs in situ des paramètresmajeurs influençant les échanges entre phases sont connus. La réalisation d'expériences, en laboratoire et/ou de terrain permet de déterminer la valeur de Kd adaptée à la situation étudiée.

We review collated data and available models for estimating the transfer of radionuclides to terrestrial biota within the European Arctic. The most abundant data are for radiocaesium and radiostrontium although many data for natural radionuclides are available. For some radionuclides no data are available for describing transfer to Arctic biota. Allometric-kinetic models have been used to estimate transfer for radionuclide-biota combinations. Predicted values were in good agreement with observed data for some radionuclides although less so for others. There are no bespoke models to enable the dynamic prediction of radionuclide transfer to Arctic biota. A human Arctic foodchain model has been adapted to estimate 137Cs and 90Sr transfer to some Arctic biota. There are many factors of Arctic ecosystems which may influence radionuclide behaviour including short growing seasons, prolonged soil freezing, and effects of low temperatures on biological rates. If exposure to ionising radiation in Arctic ecosystems is to be robustly predicted such factors must be fully understood and incorporated into models.

The activity concentrations of primordial radionuclides(40K, 226Ra and 232Th) in fivedifferent types of commonly used building materials in southwestNigeria were measured using a low-background NaI(Tl) detector coupledto an IBM-compatible multichannel analyzer. The highest mean concentrationof 40K, which was 887.5 ± 101.3 Bq.kg–1, was obtainedin gravel. Also, the highest mean concentrations of 226Raand 232Th were obtained, respectively, in sand and brick samples.The lowest mean concentrations of 40K, 226Raand 232Th, respectively, were obtained in brick and cementsample. The annual gonadal effective dose (AGED) and other radiologicalparameters were estimated from the activity concentrations of theradionuclides. The highest mean values of the AGED and radium equivalentactivity concentration obtained were 359.1 μSv.y–1 and110.9 Bq.kg–1, respectively. All these radiological parameterswere below the maximum permissible levels recommended for safe useof materials in building construction. It can therefore be concludedthat these materials do not pose any radiological hazard to thedwellers of buildings constructed with them.

Les pratiques de radioprotection des patients sont peudocumentées en Afrique subsaharienne en raison de l’absence ou dela mise en œuvre approximative des lois et règlements qui y sontrelatifs. Ce travail investigue la justification et l’optimisationen scanographie pédiatrique dans deux hôpitaux universitaires deYaoundé au Cameroun. L’enquête rétrospective portait sur 171 examenschez des enfants de 0 à 15 ans pendant un trimestre. Les données collectéesà l’aide d’une fiche adaptée du modèle de l’Institut de radioprotectionet de sureté nucléaire d’évaluation dosimétrique en scanographieont été confrontées aux référentiels de la Société française deradiologie et de la Société francophone d’imagerie pédiatrique etprénatale. La conformité de chaque examen a été analysée et lesvaleurs d’index de dose scanographique et de produit dose longueur(PDL) ont été comparées aux niveaux de référence diagnostiques (NRD)des référentiels ci-dessus.Si tous les examens étaient justifiés,les protocoles, non affichés, étaient variables selon les équipeset les services. La tension était conforme dans 87,7 % des cas et 15,2 %des PDL étaient supérieurs aux NRD pour les scanners thoraciqueset abdominaux en mode spiralé et cérébraux en mode séquentiel. Unaffichage des protocoles optimisés est nécessaire pour améliorerles pratiques dans ces services avec une rotation importante detechniciens et résidents de radiologie.

Transfer factors of 226Ra, 210Pb and 210Po from soilcontaminated with naturally occurring radioactive materials (NORM) in oilfields to somegrazing plants were determined using pot experiments. Contaminated soil was collected froma dry surface evaporation pit from a Syrian oilfield in the Der Ezzor area. Five types ofplants (Atriplex halimus L., Atriplex canescens, Atriplex Leucoclada Bioss,Alfalfa and Bermuda grass) were grown and harvested three times over two years.The results show that the mean transfer factors of 226Ra from the contaminatedsoil to the studied plant species were 1.6 × 10-3 for Atriplexhalimus L., 2.1 × 10-3 for Atriplexcanescens, 2.5 × 10-3 for Atriplex LeucocladaBioss, 8.2 × 10-3 for Bermuda grass, and thehighest value was 1.7 × 10-2 for Alfalfa. Transferfactors of 210Pb and 210Po were higher than 226Ra TFs byone order of magnitude and reached 7 × 10-3, 1.1 × 10-2,1.2 × 10-2, 3.2 × 10-2 and 2.5 × 10-2for Atriplex halimus, Atriplex canescens, Atriplex Leucoclada Bioss, Bermuda grassand Alfalfa, respectively. The results can be considered as basevalues for transfer factors of 226Ra, 210Pb and 210Po insemiarid regions.

Compartment models are widely used for the evaluation of radiological consequences to man and biota in the marine environment over large spatial and long temporal scales. The model developed at the Norwegian Radiation Protection Authority (NRPA) is based on a compartment modelling approach that includes terms describing dispersion of radionuclides into oceanic space with time (non-instantaneous mixing in oceanic space). In this paper the latest modification of the NRPA model will be presented. The main improvement concerns the “time of availability” parameters (i.e. the times at which dispersed radionuclides reach compartment boundaries). The modifications have been implemented through the use of a comprehensive 99Tc data set collected under the course of the project “RADNOR” and through comparison with the results of simulations provided by the 3D hydrodynamic NAOSIM model. The present version of the NRPA model describes the dispersion of 99Tc in the Arctic Ocean and seas with a significantly improved precision for some marine regions. Results of the calculations indicate that defined “time of availability” parameters are in good agreement with transit times observed in the actual marine environment.