The assessment of the radiological impact of a decommissionednuclear power plant is presented here through the results of anenvironmental monitoring survey carried out in the area surroundingthe Garigliano Power Plant. The levels of radioactivity in soil,water, air and other environmental matrices are shown, in whichα, β and γ activity and the γ equivalent dose rate are measured.Radioactivity levels of the samples from the Garigliano area areanalyzed and then compared with those from a control zone situatedmore than 100 km away. Moreover, a comparison is made with a previous surveycarried out in 2001. The analyses and comparisons show no significantalteration in the radiological characteristics of the area surroundingthe plant, with the overall radioactivity depending mainly on theglobal fallout and natural sources.

Radon (222Rn) is the most important cause of exposure to mankind due to natural radioactivity. Radon exhalation depends not only on the 226Ra concentration in the material, but also on other factors such as mineralogy of the region, size and density of grains and porosity of the material. As building materials are one of the major sources of environmental radon, the radiological implications of the use of materials with great content of uranium must be always assessed. In this work, radon exhalation from several undamaged granitic building materials used as ornamental rocks or coating tiles is determined using the “sealed-can technique” and CR-39 solid state nuclear track detectors (SSNTD). Preliminary results for radon concentrations showed values of the same order that literature values, in a range from 99 Bq.m−3 to 1100 Bq m−3. Further, the methodology will be validated with standard sources of 222Rn.

The rate of chromosome aberrations has been studied in higher aquatic plants: common reed, sagittaria, flowering rush and manna. The main water bodies were Glubokoye and Dalekoye-1 Lakes (left-bank flood lands of the Pripyat River), Azbuchin Lake and Yanovsky Crawl (right-bank flood lands of the Pripyat River), Cooling Pond of the Chernobyl NPP as well as Pripyat and Uzh Rivers. In decreasing sequence due to the absorbed dose rate for hydrobionts the first were water bodies of the left-bank flood lands of the Pripyat River, the second ones from right-bank flood lands. The highest chromosome aberrations rate in root meristems was registered in plants from lakes within the left-bank flood lands of the Pripyat River, the lowest one – in plants from the Pripyat and Uzh Rivers. The chromosome aberration rate in closed and slow-running water bodies within the right-bank flood lands of the Pripyat River was in 3–4 times higher than spontaneous mutagenesis level. It seems that spectrum of the main types of chromosome damages in plants of right-bank flood lands determines by chemical mutagens. The type of chromosome damages distribution in plants of the left-bank flood lands points to practically equivalent effects of radiation and chemical factors.

The organic carbon accumulation rate in mangrove ecosystem was reported to be important sink of carbon as well as that in boreal peat accumulation. For the estimation of 10 years scale organic carbon accumulation rates at mangrove plantation coastal area, the 210Pb is expected to be suitable for decades scale estimation by its half-life, though it has possibility of bio-/physical- turbation effect in applying 210Pb chronology, especially in Asian mangrove ecosystem where the anthropogenic physical turbation by coastal fishery is vigorous. We studied the organic carbon and 210Pb accumulation rates in subtropical mangrove coastal ecosystems in Japan, Vietnam and Thailand to remove the effect of bio- anthropogenic turbation on organic carbon accumulation. We finally concluded that 210Pb was applicable to estimate organic carbon accumulation rates in these ecosystems. The measured organic carbon accumulation rates using 210Pb in mangrove coastal ecosystems of Japan, Vietnam and Thailand were $0.22 - 6.0$ t-C ha-1 y-1.

Mathematical computer model is developed to simulate the population dynamics and dynamic mass budgets of the microbial community realized as a self sustainable aquatic ecological system in the tube. Autotroph algae, heterotroph protozoa and saprotroph bacteria live symbiotically with interspecies' interactions as predator-prey relationship, competition for the common resource, autolysis of detritus and detritus-grazing food chain, etc. The simulation model is the individual-based parallel model, built in the demographic stochasticity, environmental stochasticity by dividing the aquatic environment into patches. Validity of the model is checked by the multifaceted data of the microcosm experiments. In the analysis, intrinsic parameters of umbrella endpoint regarding to lethality are manipulated at the individual level, and tried to find the population level, community level especially focused on predator-prey relationship, and revealed the indirect effect of chronic exposure of radiation on the probability of Tetrahymena's extinction.

Dans le cadre de la surveillance radiotoxicologique du personnel après suspicion de contamination interne par les radioémetteurs alpha, il est essentiel de rechercheret de doser les actinides de manière spécifique dans les milieux biologiques. La technique proposée permet, sur un même échantillon, de mesurer l'activité des isotopes de l'uranium et du plutonium, de l'américium et du curium, en s'affranchissant de l'activité due au thorium et à ses descendants. Cette technique utilise d'une part le pouvoir extractant de nouveaux composés organiques fixés sur desrésines inertes et d'autre part les potentiels de fixation et d'élution des divers actinides en fonction de la composition ionique et du pH des solutions utilisées.

An allometric scaling approach has been used to calculate biological half-lives of elimination (TB1/2) and concentration factors (CF) for radionuclides in marine biota. Power functions of organism mass are fitted to a biokinetic database for plankton, seaweed, fish, crustaceans and molluscs, using data generated by us, in combination with reviewed data. Scaling of the CF to M-0.26 ± 0.09 is observed, compatible at ±1σ with metabolic theory predictions that metabolism scales to M0.75. We also observe scaling of TB1/2 to M+0.16 ± 0.03, within the previously reported range +0.15 to +0.30 for biota from various environments and, at < ± 3σ, slightly outside turnover rate scaling predictions to M-0.25. The elements for which the CF scales better allometrically are particle seeking, mainly lanthanides and actinides. Association of the independent term of the allometric power function a with the sediment-water partition coefficient Kd is strongest for these elements, possibly through binding to biological/organic matter. The findings from this study are relevant to extend the range of applicability of our biota dose assessment methodologies where data gaps in transfer exist.

The radionuclide contents in waste products and physico-chemical characterization of effluent samples from some selected industries in the city of Lagos were carried out. The radioactivity concentration levels due to 40K, 226Ra and 228Th in the solid wastes were determined using gamma-ray spectrometry while physico-chemical determination of parameters were based on standard methods of measurements. The average radioactivity levels obtained was between 104 ± 14 Bq kg-1 and 1276 ± 31 Bq kg-1 for 40K, 86 ± 18 Bq kg-1 and 122 ± 23 Bq kg-1 for 226Ra and while for 228Th it ranged between 14 ± 2 Bq kg-1 and 73 ± 10 Bq kg-1. No artificial radioactive elements were detected in any of the samples. The average outdoor effective dose rate due to gamma exposure from these waste materials in the city was calculated as 0.12 mSv y-1. This is far less than 1 mSv y-1 recommended limit for the member of the public by United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The pH of the effluent samples was slightly alkaline, while the electrical conductivity ranged between 275 and 455 µS cm-1 and total suspended solids ranged from 104 to 5616 mg l-1. All these ranges and those of biochemical and chemical oxygen demand values were all higher than the prescribed limits. Presence of heavy metals in the effluent samples was however lower than prescribed with the exception of iron.

Earthworms and their growth media were analyzed for 33 elements, including radionuclide related elements such as Cs, Sr and U, in order to obtain basic information on the transfer parameters of the elements. The earthworms analyzed were Eisenia foetida fed in the laboratory by using cotton linters or leaf litter. The concentrations and transfer factors (TFs) of the elements were determined. Relatively high TFs were observed for Na, Mg, P, K, Ca, Co, Ni, Cu, Zn, Rb, Mo and Cd. The TFs for Al, Sc, Ti, Y, Nb and lanthanide elements were low. The TFs of alkaline elements, K, Rb and Cs, decrease with atomic number. The TFs of Cs were 0.16 for both media. Multi-element analyses could provide much information on the concentration and transfer of elements for earthworms which are one candidate reference organism for environmental radiation protection studies.

A widely applied method of supported lead estimation in sediments using gamma spectrometric 226Ra determination via 222Rn short lived daughter products relies on radioactive equilibrium between 226Ra and 222Rn being established after sealing the samples. Advantages and disadvantages of methods of 226Ra estimation in sediments, using either 226Ra daughter products or direct estimation by the 186.2 keV gamma-emissions are discussed. An equilibrium experiment was performed using test samples and in one case radioactive equilibrium was not reached. On theoretical sediment profiles it is shown how systematic errors in supported 210Pb estimation can lead to wrong interpretations of 210Pbxs profiles and therefore affect 210Pb derived chronologies.

Naturally occurring radioactive materials (NORMS) and fallout 137Cs were estimated in surface soils from the highly mineralized Singhbhum region of Eastern India. The activity concentrations varied from 50.67-109.14 Bq/kg (238U), 48.12-142.55 Bq/kg (226Ra), 28.73-89.78 Bq/kg (232Th), 494.84-1121.36 Bq/kg (40K) and 1.8-7.48 Bq/kg (137Cs). Correlation between radionuclides was studied. 232Th/238U concentration (Clark value) was also calculated. Radiation hazard for the samples was assessed by radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin) and absorbed gamma dose rate (D). Raeq values ranged from 216-263 Bq/kg, Hex values from 0.58-0.71 Bq/kg, Hin values from 0.73-1 Bq/kg and D values from 100-121 nGy/h. Calculated and observed dose rates in air were compared with the help of parametric and non-parametric tests. The tests showed significant difference between the calculated and observed dose rates.

L’uranium est un radioélément ainsi qu’un métal lourdauquel l’homme peut être exposé du fait de sa présence dans l’environnementou des activités humaines. Il exerce principalement une toxicitéchimique au niveau du tubule contourné proximal du rein après expositionaiguë ou chronique. Après exposition à une forte dose d’uranium,la néphrite tubulaire aiguë est révélée par une protéinurie ainsi qu’unediminution du débit de filtration glomérulaire. Plus récemment,l’utilisation de marqueurs d’intégrité tissulaire telle que la béta2-microglobuline ou des enzymes tissulaires a pu être corrélée auxaltérations histopathologiques des tubules contournés proximaux.Lors d’exposition chronique à de faible niveau, l’utilisation demarqueurs plus spécifiques et plus sensibles s’avère nécessairelorsque les lésions sont faibles. Des études expérimentales développéesau laboratoire ont montré la pertinence de certains de ces biomarqueurstel que Kim-1 pour détecter de faibles altérations rénales. L’uraniumexerce sa cytotoxicité au niveau des cellules épithéliales des tubules contournésproximaux probablement du fait de son entrée dans la cellule oùil s’accumule préférentiellement dans le noyau cellulaire, lorsqu’iln’est pas sous forme de précipités. Les mécanismes conduisant àla mort des cellules ne sont pas encore totalement élucidés maisle stress oxydant semble y jouer un rôle important.

Tritium can represent a key radionuclide in the aquatic environment, in some cases, contributing significantly to the doses received by aquatic non-human biota and by humans due to aquatic releases. Recently, the necessity to have a robust assessment of tritium routine and accidental risk emissions for large nuclear installations increased the interest in the topic. In the present study, the recent experiments concerning tritium transfer in adult rainbow trout are described. The updated model concerning the dynamics of tritium transfer in aquatic food chain (AQUATRIT model) developed by the authors is applied and tested for these experimental data. The model predicts the experimental data with a factor of 2 to 3 and the potential improvements of the model are discussed. The present model results emphasize that in the field conditions, the major factors influencing the OBT biological loss rate are the temperature and the prey availability while, the OBT uptake is mainly influenced by the fish growth rates. The main goals of this study are to enhance the robustness of aquatic models for tritium risk assessment and to fulfil a gap for aquatic pathways in environment.

Une méthode radiochimique sélective de liode a été développée afin de mesurer 129I (période 1,57x107 ans) par spectrométrie gamma à basses énergies dans les échantillons biologiques. Elleévite la mise en oeuvre de moyens lourds (activation neutronique ou spectrométrie de masse par accélérateur). La méthode est basée sur lextraction de liode des échantillons afin dobtenir unematrice aqueuse standard ne contenant aucun agent datténuation du signal de 129I autre que 127I (stable). Le dosage de 127I, en fin de radiochimie, permet une correction de cette atténuation etune prise en compte des fluctuations saisonnières du métabolisme de liode dans certaines espèces. Des mesures ont été réalisées dans deux algues marines (Fucus serratus et Laminariadigitata) prélevées en janvier et février 1997 dans une zone soumise aux rejets marins de lusine de retraitement de La Hague. Pour les stations proches du point de rejet, les activités en 129I sont de lordre de 60 Bq kg-1 sec dans Fucus serratus et de lordre de 300 Bq kg-1 sec dans Laminaria digitata. A 300 km du point de rejets, les activités en 129I sont de 10 Bq kg-1 sec dans Fucus serratus et de 171 Bq kg-1 sec dans Laminaria digitata. Les concentrations en 127I sont comprises entre 547 et 1 232 mg kg-1 sec dans Fucus serratus et entre 6 624 et 14 296 mg kg-1 sec dansLaminaria digitata pour la période de prélèvements considérée.

A twenty-year follow-up study was carried out at Baiyun Obo Rare-earth Iron Mine in China, This mine has been mined since 1958. Its ore contains 0.04% of ThO2 and 10% of SiO2. The purpose of this study is to investigate possible health effects in dust-exposed miners following long-term exposure to thorium-containing dusts and thoron progeny. By using the negative high voltage exhaled thoron progeny measurement system to estimate the miner’s thorium lung burden. The highest thorium lung burden among 1 158 measurements of 638 miners was 11.11 Bq. The incidence of stage 0+ pneumoconiosis was increased among dust-exposed miners. An epidemiological study showed that the lung cancer mortality of the dust-exposed miners was significantly (p < 0.005) higher than that of the non-exposed group. It is suggested that the difference results in the long-term exposure to thorium-containing dusts (carcinogens are ThO2 and SiO2) and thoron progeny. This is the first evidence in humans of the carcinogenicity after long-term inhalation of thorium-containing dusts and thoron progeny. The total person-years of observation for the dust-exposed miners and the controls were 62 712 and 34 672 respectively.

Assessments of radiation exposure of reptiles may be required in some countries as many species are protected. However, there are few data available for the transfer of radionuclides to them, especially in terrestrial ecosystems, and consequently, no specific peer reviewed reptile data have been used in the derivation of default transfer parameters in the ERICA Tool. Twenty samples of Lacerta agilis (sand lizard) and five of Natrix natrix (grass snake) were collected from two sites within the Chernobyl Exclusion Zone and analysed for Pu-isotopes, 137Cs and 90Sr. Corresponding activity concentrations for soil from the sampling sites were available. These data have been used to derive concentration ratios (CR) (i.e. reptile whole-body fresh weight activity concentration relative to the dry weight activity concentration in soil). CR values for N. natrix tended to be lower than those for L. agilis. The CR values derived in this paper will be used to improve the default values provided within the ERICA Tool. Whole-body activity concentrations determined in the reptile samples were broadly comparable with data available from the same sampling sites for small mammal species.

Le service de santé au travail du CEA/CADARACHE est un service médical de site chargé de la surveillance radiologique de l'exposition interne de l'ensemble du personnel travaillant sur le centre de Cadarache. Dans notre activité spécifique de surveillance du risque radiologique prédomine la gestion des expositions aux actinides, plutonium et américium principalement, avec environ 600 agents concernés. Nous présentons les protocoles de prise en charge des incidents de contamination que nous avons élaborés et mis en place en 1996 ainsi que le retour d'expérience sur plus de 1 500 évènements gérés jusqu'à fin 2002.

In view of its high potential for containing large amounts of radioactive materials and due to its wide-spread use as construction and facing material worldwide, radiation doses received from the marble used in dwellings have been determined. As a first step, specific activity measurements were made using a NaI(Tl) gamma ray spectrometer using the spectrum stripping technique. For the samples studied, the average values of specific activities for 226Ra, 232Th and 40K have been found to be 27, 26 and 58 Bg kg-1 respectively. The mesh-adaptive, volume-integral method based code INGRE (Mirza et al., 1991) gave calculated values of the dose equivalent rates inside the standard room (Tufail et al., 1994) due to 226Ra, 232Th and 40K; these we re found to lie between 5-77, 12-52 and 1-11 nGy h-1 respectively. The values of whole-body dose equivalent rates have been found to lie in the 27-108 nGy h-1 range. As these values are below internationally accepted maximum permissible values, therefore marble available in Pakistan can safelybe used in dwellings as a construction material.

Within the scope of a joint IRSN/EDF research program, it is possible to present a first status of free water tritium and organically bound tritium levels in the French coastal marine environment, from Concarneau to Gravelines. Seasonal sampling was conducted over two years, 2001 and 2002. The matrices selected for this specific survey include water, seaweed, molluscs, crustaceans and fish. The background concentration, estimated from the results obtained at two sites, Concarneau and Roscoff, remote from industrial sources, is close to the detection limit of 1,2 Bq.l-1. Along the Channel coast and the entrance of the North Sea, tritium is released in seawater by four nuclear power plants (14 reactors) and mainly by the reprocessing plant of La Hague. The concentrations measured are in good agreement with activities calculated with the hydrodynamic model of dispersion TRANSMER. The results confirm a dilution factor of two between the north Cotentin area and the Straits of Dover for soluble radionuclides. The concentrations are in the range of 2 to 20 Bq.l-1 for free and organically bound tritium in biota. Although isotopic fractionation is theoretically expected to be slight, the available results indicate a ratio between tritium bound to organic matter and tritium in free water greater than one.

Precise and accurate measurement of uranium isotope ratio is essential in environmental monitoring of any contamination in nuclear safeguards. 234U, 235U and 238U are naturally occurring alpha-emitting long-lived radionuclides, which are taken up daily at low levels with food and drinking. IUPAC has established natural isotopic composition of 235U/238U to be 0.00725. Therefore, isotope ratio measurements are important to provide information on the origin of uranium. The isotope ratios of uranium, 234U/238U, 235U/238U and 236U/238U were measured using a VG Sector 54 thermal ionization mass spectrometer (TIMS) as well as high resolution inductively coupled plasma mass spectrometry (ICP-MS) in soil samples as well as in some water samples collected in the exclusion zone of Chernobyl nuclear power plant. The isotopic composition of Chernobyl soil samples showed significant deviation from the natural uranium and presence of 236U is quite noticeable. The 234U/238U activity ratio varies in the range 1.06 to 2.1 and 1.42 to 5.75 for soil and water samples, respectively. Enrichment of 235U was also noticeable for soil as well as ground water samples.