Le standard CEI 62471 décrit les limites d’exposition aux sources de rayonnements optiques incohérentes à large spectre, depuis l’UV jusqu’à l’IR en passant par le visible. Son application apparaît particulièrement justifiée pour l’évaluation de sources à LEDs blanches à luminophore, qui combinent une luminance élevée et un spectre riche en ondes courtes (bleu), ce qui expose potentiellement l’œil humain à un risque de lésions rétiniennes (Blue Light Hazard). En théorie, il s’agit simplement de mesurer la luminance énergétique spectrique de la source lumineuse à l’intérieur du champ visuel de l’œil en mouvement puis de la pondérer par la fonction décrivant le risque rétinien en lumière bleue. En pratique cependant, la mesure est assez faiblement répétable lorsque les sources en question n’offrent que des surfaces relativement inhomogènes du point de vue de la luminance. Des protocoles de mesures basés sur l’imagerie CCD permettraient probablement d’améliorer la répétabilité de la mesure. Cet article propose une première approche d’une méthode simple d’évaluation du risque par imagerie monospectrale.

CT scanning technology is a valuable tool to diagnose many diseases; however, the level of the radiation dose is a source of concern, especially for children. CT scan systems and dose measurement methods have evolved over the years; but reported pediatric effective doses (EDs) have sometimes exceeded the annual dose limit recommended by the ICRP (1 mSv per year for persons under 18 years) (ICRP, 2007a). Efforts have been made to reduce organ doses and EDs by adjusting the scan parameters. This paper describes the determinants of the ED, and the dose reduction techniques in pediatric imaging from the early age of CT examinations until now. The first epidemiological results regarding the associated risk of cancer are also briefly presented.

Présents dans notre environnement les rayonnements électromagnétiques (EM) suscitent de multiples questions quant à leurs effets potentiels pour les porteurs de dispositifs médicaux actifs implantés (DMAI). Le nombre croissant de porteurs d’implants médicaux, y compris dans la population active, a entraîné un questionnement quant à leur comportement en présence d’un champ EM. L’interaction entre le corps humain et les champs EM reste complexe et dépend de multiples facteurs tels que la fréquence, la puissance et la modulation des champs. Nous présentons ici une revue de cette problématique dans le cas des champs EM basse fréquence.

This work suggests a classification of interventional radiology and cardiology procedures based on statistical analysis of operators’ finger doses measured in routine clinical conditions. In total, 346 finger doses were measured and the observed mean finger dose per class of procedure ranged from 0.03 mSv to 1.56 mSv for Cerebral, and Bone and Joint procedures, respectively. The statistical analysis showed that the finger dose in Cerebral procedures is significantly lower than in Cardiac procedures, which was significantly lower than the rest. Furthermore, finger doses in therapeutic procedures and in close ones were significantly greater than in diagnostic procedures and in distal ones. This work also studied the statistical relation between the use of ceiling-suspended shields or leaded gloves and the extremity dose. From the set of collected and analyzed data, a finger dose classification was proposed for different criteria: procedure type (diagnostics/therapeutic), proximity (close/distal), procedure class and access route.

The separate contributions of all source regions to organ doses from 131I and 123I administered to the body were calculated using voxelized reference phantoms. The photon and electron components of organ doses were also evaluated for each source region. The MCNPX Monte Carlo particle transport code was utilized for dose calculations. All organs and tissues of male and female phantoms were taken into account as source regions with their corresponding cumulated activities. The results showed that cumulated activities assigned to source regions and inter-organ distances were two factors that strongly affected the contribution of each source to the organ dose. The major contribution of the dose to the main source regions arose from self-irradiation of electrons, while for nearby organs it was due to photons emitted by the main source organs. In addition, self-irradiation plays an important role in the dose delivered to most target organs for lower thyroid uptakes.

The aim of this study is to provide data that increase knowledge about the possible health effects of exposure to 90Sr contaminant in drinking water. 90Sr detection in the mouse bone model plays an important complementary role with computational dosimetry in these investigations. S-value (absorbed dose per unit cumulated activity) calculations using Monte Carlo (MC) simulations, 90Sr detection by liquid scintillation β counting in the femur bone and X-ray microanalysis were carried out. The present work is focused on using MCNPX and its validation at a cellular level. The cytoplasm (Cy), nucleus (N) and 90Sr radiation source were simulated with the MC code MCNPX. Cells are assumed to be spherical, with the radii of the cell and cell nucleus ranging from 2 to 10 μm. The S-value (in Gy/Bq.s) calculations were provided for a 90Sr source distributed uniformly in the cell nucleus or cytoplasm and for two source-target combinations (t←s). A comparison between the calculated MC results and the MIRD values agreed very well since the relative deviations are less than 4%. The earliest results of X-ray microanalysis indicated that the 90Sr was below the detection limit (<0.1%) in the bone tissue. However, the measurements by liquid scintillation showed the presence of 90Sr in the femur bone.

The observations made in Japan in 2011 after the Fukushima-Daiichi accident and those made in France, Italy, Greece and Austria in 1986 after the Chernobyl fallout, show that the development stage of orchard trees at the time of atmospheric deposition is a major factor determining the level of caesium contamination in fruits at harvest. Both data sets are shown to be consistent and enable one to estimate, for mobile elements in plants such as caesium, an aggregated transfer factor (expressed in Bq.kg-1 of fresh fruit per Bq.m-2 deposited on the ground surface) whose value strongly depends on the time elapsed between fallout and harvest. The Fukushima data set also enables one to estimate effective half-lives (expressed in days), which are helpful for predicting the decrease in fruit contamination with time. We found an average value of 200 days for the one-year period after radioactive fallout, which is quite consistent with values estimated from post-Chernobyl surveys.

This article proposes an assessment of the ingestion doses potentially received by people living in the Japanese areas most severely affected by the radioactive deposits due to the Fukushima nuclear accident. The assessment distinguishes two consecutive periods: the first 2 months (March 15th to May 15th 2011) and the rest of the year 2011, according to the two main foodstuff contamination periods identified (Renaud et al., 2013). On the basis of the worst-case hypothesis that can reasonably be made, the estimated doses are much lower than they might have been in other circumstances, on account of generally moderate levels of contamination for most foods, early evacuation of the most severely affected areas and the consumption bans ordered by the Japanese authorities. Thus, a single ingestion of 100 g of leafy vegetables in the early days by a one-year-old child living in non-evacuated localities near Iitate and Kawamata could have led to an equivalent dose to the thyroid of about 25 mSv; and to a thyroid dose of about 140 mSv for the rather unrealistic scenario of a daily consumption. Because of the rapid decrease in the contamination of vegetables and a much weaker contamination of other crops, and thanks to measures taken by the authorities (prohibition of consumption, use of certain fodder, etc.), the ingestion doses potentially received during the remainder of the year 2011 are estimated to be below 1 mSv. In the event that sales limits would have been ignored, only repeated consumption of mushrooms would have led to doses above that level. Even with the worst-case hypotheses, the doses potentially caused by ingestion are much lower than those resulting from outdoor exposure to radioactive deposits: approximately several millisieverts in a year for the population living in the non-evacuated localities near Iitate and Kawamata.

La fabrication de verre plombé n’a pas encore été développée en Colombie, ce qui entraîne des lacunes dans la recherche d’améliorations des composants pour la protection radiologique. Le Groupe de Physique Médicale de l’Université Nationale de Colombie a donc initié une étude en vue de développer différents échantillons de verre plombé qui soient adaptés à une utilisation comme blindage contre les rayonnements ionisants. Les caractéristiques optimales ont été trouvées pour une concentration de 50 % d’oxyde de plomb (PbO) dans un verre de plomb-silicate. Un pourcentage de PbO supérieur entraîne des difficultés techniques et une diminution de la clarté du verre. Pour cette fraction molaire nous avons trouvé un coefficient d’absorption linéaire de 0,35 cm-1, c’est-à-dire que pour une énergie de 662 keV un centimètre de ce verre correspond à 3,0 mm de plomb pur; avec cette même énergie la couche de demi-atténuation (CDA) de l’échantillon est égale à celle du ciment ferreux utilisé couramment dans les blindages radiologiques. Enfin il a également été observé que l’application d’une couche d’air de 1 cm entre les lames de verre diminue la transmission des photons jusqu’à 20 % pour le verre contenant 40 % de plomb.

Interventional cardiologists (ICs) are repeatedly exposed to scattered ionising radiation during the cardiac procedures they perform, and radiation protection is an important issue for these medical professionals. The use of radiation protection tools is particularly relevant to this population. SISERI (Système d’Information de la Surveillance de l’Exposition aux Rayonnement Ionisants, that is, an information system for monitoring exposure to ionising radiation) is a register that stores personal dosimeter readings for dosimetric monitoring. This paper, based on data for a sample of French ICs from the O’CLOC epidemiological study, aims to provide an overview of the use of radiation protection equipment and dosimetric devices reported by ICs in a specific questionnaire as well as the dosimetric information found in the SISERI database for this population. Material and Methods − Annual information on interventional cardiology activity for the period from 01/01/2005 to 31/12/2009 was collected in an occupational questionnaire. ICs were asked to report the frequency in which they used individual dosimeter and radiation protection tools (lead apron, thyroid shield, eyewear or face shield, ceiling-suspended shield) as follows: never (0% of the time), occasionally (<50%), regularly (>50%), always (100%). We retrieved their medical radiation exposure information (monitored status and monthly effective doses) from the SISERI database for the period 2005−2009. Results – Information for 132 ICs (mean age in 2005 = 46 ± 7 years) was available. All ICs reported routine use of lead aprons, in contrast to their occasional use of lead eyewear or face shields. During the study period, 49% reported systematic use of personal dosimeters, and 21% more regular use. On the other hand, 18% never used a dosimeter during this period. The SISTERI database included 92% of our population, 73% of whom had complete annual dose monitoring in SISERI (corresponding to at least 11 months per year of recorded data). Conclusion − ICs must improve their regular use of radiation protection tools and systematic use of personal dosimeters. The SISERI database is an appropriate tool for flagging those medical professionals exposed to ionising radiation. Better awareness of the importance of radiation protection rules in this population, in particular, systematic dosimeter use, remains an important issue.

The Monte Carlo MCNPX code is used to calculate the scatter fraction, making it possible to assess the scattered dose equivalent rate. Two materials are considered for the phantom: water and steel. The calculations are performed by considering beams of monoenergetic photons (in the range 10 keV to 10 MeV) and bremsstrahlung photons resulting from the interaction of electrons (30–900 keV) on a tungsten target. The variation of the scatter fraction is investigated as a function of the primary photon energy, the beam area at the phantom surface, the scattering angle, and filtration of the bremsstrahlung radiation. We note the shortcomings of the ISO standard issued in 2011, which does not take into account the beam area at the phantom surface, the scattering angle or the scattering materials, thus producing inconsistencies with the computed values given in this study and in the literature. Our values for the scatter fraction are comparable with those given in the literature (e.g. NCRP). As regards the bremsstrahlung radiation, we note the influence of filtration, in particular at low energies. The scatter fractions given here are compatible with the calculation of the ambient dose equivalent, whereas in the literature, they are systematically used for the calculation of air kerma rates. We also obtain scatter fractions for water that are higher by a factor of 5 compared with steel.

The term “dose constraint” has been used in radiological protection since 1990. Its practical application has varied from country to country to the present day. The authors of this paper believe that it is an underestimated tool for the purpose of radiological protection. This study aims to estimate local dose constraints for workers in conventional nuclear medicine and radiology departments, on the basis of doses received in the last 3 to 4 years by different groups of workers. The levels of exposure to employees of the nuclear medicine department correspond well to levels in other countries, but for employees belonging to the radiology department, the levels are significantly lower. Unification of the practical application of dose constraints and legislation concerning their specific values would increase the relevance and effectiveness of these operational units. This is a playing field for radiation safety officers for the determination and widespread publication of local dose constraints in their particular medical departments.

Le code de la santé publique et notamment l’arrêté du 11 janvier 2007, relatif aux limites et références de qualité des eaux brutes et des eaux destinées à la consommation humaine, fixe quatre indicateurs de la qualité radiologique des eaux du robinet (l’activité α globale, l’activité β globale, l’activité du tritium et la dose totale indicative), ainsi que des valeurs guides et des références de qualité. Les chroniques issues de la surveillance des eaux filtrées du Rhône aval montrent que, si la radioactivité d’origine naturelle demeure bien évidemment constante au cours du temps, les niveaux de contamination radioactive d’origine artificielle ont fortement diminué à partir du début des années 90, de 10 à 100 fois suivant les radionucléides. Les données soulignent également qu’aucune des limites d’activités α globale, β globale et en tritium n’a été dépassée dans l’eau filtrée du Rhône aval au cours de l’ère industrielle nucléaire. Les doses totales indicatives (DTI) calculées à partir des prélèvements d’eau filtrée du Rhône aval (canal Philippe Lamour – Réseau hydraulique régional propriété de la région Languedoc Roussillon géré par BRL), de l’Orb et de l’Hérault effectués en 2011 sont très inférieures à la valeur de référence de 100 μSv/an. La contribution à la DTI des radionucléides artificiels détectés dans ces hydrosystèmes est en outre négligeable (<0,01 %).

Transfer factors of 226Ra, 210Pb and 210Po from soil contaminated with naturally occurring radioactive materials (NORM) in oilfields to some grazing plants were determined using pot experiments. Contaminated soil was collected from a dry surface evaporation pit from a Syrian oilfield in the Der Ezzor area. Five types of plants (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 contaminated soil to the studied plant species were 1.6 × 10-3 for Atriplex halimus L., 2.1 × 10-3 for Atriplex canescens, 2.5 × 10-3 for Atriplex Leucoclada Bioss, 8.2 × 10-3 for Bermuda grass, and the highest value was 1.7 × 10-2 for Alfalfa. Transfer factors of 210Pb and 210Po were higher than 226Ra TFs by one order of magnitude and reached 7 × 10-3, 1.1 × 10-2, 1.2 × 10-2, 3.2 × 10-2 and 2.5 × 10-2 for Atriplex halimus, Atriplex canescens, Atriplex Leucoclada Bioss, Bermuda grass and Alfalfa, respectively. The results can be considered as base values for transfer factors of 226Ra, 210Pb and 210Po in semiarid regions.

We calculated mass attenuation coefficients, effective atomic numbers and Kerma relative to air for human organ and tissue substitutes (i.e. wax, plastic and polymer materials). The effective atomic numbers of the tissue substitutes were calculated by the direct method, interpolation method, Auto-Zeff software and single value XMuDat program and then compared. The calculated effective atomic numbers were also compared with available experimental data and a good agreement was observed. A large difference in effective atomic numbers calculated by the direct and interpolation methods was observed in photoelectric and pair-production regions. The direct method was found to be appropriate for effective atomic number computation in low-(>10 keV) and medium-(0.1 ≤ E ≤ 10 MeV) photon energy regions. Kerma relative to air of the selected tissue substitutes was found to be dependent upon the atomic number and element compositions, which show a sharp peak due to K-edge absorption.

The measurement performances of in vivo monitoring vehicles were studied considering an increase in the radiological background in areas where the population is not evacuated after a nuclear accident. The study focused on 137Cs and 131I Detection Limits (DLs) and corresponding doses, for adults and one-year-old children. These DLs for ground contamination were obtained experimentally using a grid of point sources. Then, the DLs and doses were calculated using the experimental data and a safety factor for two accident scenarios. For these scenarios the 137Cs DL corresponds to a committed effective dose of 0.02 mSv. The 131I DL corresponds to committed equivalent thyroid doses of 3 mSv (adult) and 30 mSv (one-year-old child). To guarantee a 45 mSv thyroid equivalent dose assessment for the child the surface activity of 131I + 132I + 133I should be below 1.6 MBq/m2. This study shows that the vehicles can operate in a contaminated area where the population is not evacuated. However, in such a case, the contamination level outside and inside the vehicle should be kept stable to guarantee efficient body counting.