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Sample records for internal dose assessment

  1. Guidance on internal dose assessments from monitoring data (project IDEAS).

    PubMed

    Doerfel, H; Andrasi, A; Bailey, M; Berkovski, V; Castellani, C M; Hurtgen, C; Jourdain, J R; LeGuen, B

    2003-01-01

    Several international inter-comparison exercises on intake and internal dose assessments from monitoring data led to the conclusion that the results calculated by different participants varied significantly, mainly due to the broad variety of methods and assumptions applied in the assessment procedure. Based on these experiences, the need of harmonisation of the procedures has been formulated as an EU research project under the 5th Framework Programme, with the aim of developing general guidelines for standardising assessments of intakes and internal doses. In the IDEAS project, eight institutions from seven European countries are participating, also using inputs from internal dosimetry professionals from across Europe to ensure broad consensus in the outcome of the project. To ensure that the guidelines are applicable to a wide range of practical situations, the first step will be to compile a database on well documented cases of internal contamination. In parallel, an improved version of existing software will be developed and distributed to the partners for further use. Many cases from the database will be evaluated independently by more partners using the same software and the results will be discussed and the draft guidelines prepared. The guidelines will then be revised and refined on the basis of the experiences and discussions of two workshops, and an intercomparison exercise organised in the frame of the project which will be open to all internal dosimetry professionals.

  2. [The methodology development of the calculating and empirical internal dose assessments at far post Chernobyl period].

    PubMed

    Vlasova, N G; Zhuchenko, Iu M; Chunikhin, L A

    2009-01-01

    The comparison analysis of internal dose assessment had been conducted by different calculated methods. The results of the WBC measurements were used as a criteria of internal dose assessment. It was shown that the methodology of the internal dose assessment intended uncertainties reducing of the received results. It is realized by means of the modern WBC modeling.

  3. SECOND LATIN AMERICAN INTERCOMPARISON ON INTERNAL DOSE ASSESSMENT.

    PubMed

    Rojo, A; Puerta, N; Gossio, S; Gómez Parada, I; Cruz Suarez, R; López, E; Medina, C; Lastra Boylan, J; Pinheiro Ramos, M; Mora Ramírez, E; Alves Dos Reis, A; Yánez, H; Rubio, J; Vironneau Janicek, L; Somarriba Vanegas, F; Puerta Ortiz, J; Salas Ramírez, M; López Bejerano, G; da Silva, T; Miri Oliveira, C; Terán, M; Alfaro, M; García, T; Angeles, A; Duré Romero, E; Farias de Lima, F

    2016-09-01

    Internal dosimetry intercomparisons are essential for the verification of applied models and the consistency of results'. To that aim, the First Regional Intercomparison was organised in 2005, and that results led to the Second Regional Intercomparison Exercise in 2013, which was organised in the frame of the RLA 9/066 and coordinated by Autoridad Regulatoria Nuclear of Argentina. Four simulated cases covering intakes of (131)I, (137)Cs and Tritium were proposed. Ninteen centres from thirteen different countries participated in this exercise. This paper analyses the participants' results in this second exercise in order to test their skills and acquired knowledge, particularly in the application of the IDEAS Guidelines. It is important to highlight the increased number of countries that participated in this exercise compared with the first one and, furthermore, the improvement in the overall performance. The impact of the International Atomic Energy Agency (IAEA) Projects since 2003 has led to a significant enhancement of internal dosimetry capabilities that strengthen the radiation protection of workers. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. A structured approach for the assessment of internal dose: the IDEAS guidelines.

    PubMed

    Doerfel, H; Andrasi, A; Bailey, M; Berkovski, V; Blanchardon, E; Castellani, C-M; Cruz-Suarez, R; Hurtgen, C; LeGuen, B; Malatova, I; Marsh, J; Stather, J; Zeger, J

    2007-01-01

    The need for harmonisation of the procedures for internal dose assessment has been recognised within an EU research project under the 5th Framework Programme. The aim of the IDEAS project was to develop general guidelines for standardising assessments of intakes and internal doses. It started in October 2001 and ended in June 2005. The project is closely related to some goals of the work of Committee 2 of the International Commission on Radiological Protection and since 2003 there has been close co-operation between the two groups. The general philosophy of the guidelines is focusing on the principles of harmonisation, accuracy and proportionality. The proposed system of 'level of task' to structure the approach of internal dose evaluation is also reported. Some details of the internal structure of the guidelines for the different pathways of intake are provided.

  5. Internal dosimetry performing dose assessments via bioassay measurements

    SciTech Connect

    Bailey, K.M.

    1993-05-11

    The Internal Dosimetry Department at the Y-12 Plant maintains a state-of-the-art bioassay program managed under the guidance and regulations of the Department of Energy. The two major bioassay techniques currently used at Y-12 are the in vitro (urinalysis) and in vivo (lung counting) programs. Fecal analysis (as part of the in vitro program) is another alternative; however, since both urine and fecal analysis provide essentially the same capabilities for detecting exposures to uranium, the urinalysis is the main choice primarily for aesthetic reasons. The bioassay frequency is based on meeting NCRP 87 objectives which are to monitor the accumulation of radioactive material in exposed individuals, and to ensure that significant depositions are detected.

  6. JADA: a graphical user interface for comprehensive internal dose assessment in nuclear medicine.

    PubMed

    Grimes, Joshua; Uribe, Carlos; Celler, Anna

    2013-07-01

    The main objective of this work was to design a comprehensive dosimetry package that would keep all aspects of internal dose calculation within the framework of a single software environment and that would be applicable for a variety of dose calculation approaches. Our MATLAB-based graphical user interface (GUI) can be used for processing data obtained using pure planar, pure SPECT, or hybrid planar/SPECT imaging. Time-activity data for source regions are obtained using a set of tools that allow the user to reconstruct SPECT images, load images, coregister a series of planar images, and to perform two-dimensional and three-dimensional image segmentation. Curve fits are applied to the acquired time-activity data to construct time-activity curves, which are then integrated to obtain time-integrated activity coefficients. Subsequently, dose estimates are made using one of three methods. The organ level dose calculation subGUI calculates mean organ doses that are equivalent to dose assessment performed by OLINDA/EXM. Voxelized dose calculation options, which include the voxel S value approach and Monte Carlo simulation using the EGSnrc user code DOSXYZnrc, are available within the process 3D image data subGUI. The developed internal dosimetry software package provides an assortment of tools for every step in the dose calculation process, eliminating the need for manual data transfer between programs. This saves times and minimizes user errors, while offering a versatility that can be used to efficiently perform patient-specific internal dose calculations in a variety of clinical situations.

  7. General guidelines for the assessment of internal dose from monitoring data: progress of the IDEAS project.

    PubMed

    Doerfel, H; Andrasi, A; Bailey, M; Blanchardon, E; Cruz-Suarez, R; Berkovski, V; Castellani, C-M; Hurtgen, C; LeGuen, B; Malatova, I; Marsh, J; Stather, J; Zeger, J

    2007-01-01

    In recent major international intercomparison exercises on intake and internal dose assessments from monitoring data, the results calculated by different participants varied significantly. Based on this experience the need for harmonisation of the procedures has been formulated within an EU 5th Framework Programme research project. The aim of the project, IDEAS, is to develop general guidelines for standardising assessments of intakes and internal doses. The IDEAS project started in October 2001 and ended in June 2005. The project is closely related to some goals of the work of Committee 2 of the ICRP and since 2003 there has been close cooperation between the two groups. To ensure that the guidelines are applicable to a wide range of practical situations, the first step was to compile a database of well-documented cases of internal contamination. In parallel, an improved version of an existing software package was developed and distributed to the partners for further use. A large number of cases from the database was evaluated independently by the partners and the results reviewed. Based on these evaluations, guidelines were drafted and discussed with dosimetry professionals from around the world by means of a virtual workshop on the Internet early in 2004. The guidelines have been revised and refined on the basis of the experiences and discussions in this virtual workshop. The general philosophy of the Guidelines is presented here, focusing on the principles of harmonisation, optimisation and proportionality. Finally, the proposed Levels of Task to structure the approach of internal dose evaluation are reported.

  8. Internal dose assessment data management system for a large population of Pu workers.

    PubMed

    Bertelli, L; Miller, G; Little, T; Guilmette, R A; Glasser, S M

    2007-01-01

    This paper describes the design and implementation of the Los Alamos National Laboratory (LANL) dose assessment (DA) data system. Dose calculations for the most important radionuclides at LANL, namely plutonium, americium, uranium and tritium, are performed through the Microsoft Access DA database. DA includes specially developed forms and macros that perform a variety of tasks, such as retrieving bioassay data, launching the FORTRAN internal dosimetry applications and displaying dose results in the form of text summaries and plots. The DA software involves the following major processes: (1) downloading of bioassay data from a remote data source, (2) editing local and remote databases, (3) setting up and carrying out internal dose calculations using the UF code or the ID code, (3) importing results of the dose calculations into local results databases, (4) producing a secondary database of 'official results' and (5) automatically creating and e-mailing reports. The software also provides summary status and reports of the pending DAs, which are useful for managing the cases in process.

  9. Internal dose assessment -- Operation Crossroads. Technical report, 11 January 1984-15 April 1985

    SciTech Connect

    Phillips, J.; Klemm, J.; Goetz, J.

    1985-10-30

    The radiation dose commitment to ten body organs/parts, due to inhalation of resuspended nuclear contaminants from target ships exposed to the underwater burst (Test Baker) is determined for personnel who worked on the ships during and after Operation CROSSROADS. Four representative ships, INDEPENDENCE, NEW YORK, PENSACOLA and SALT LAKE CITY, are examined for the personnel activities associated with post-BAKER reboarding. Additionally, the dose due to internal emitters is assessed for personnel who unloaded ammunition from twenty target ships at Kwajalein, and for shipyard workers exposed to eight of the higher intensity ships at Pearl Harbor, Puget Sound, and San Francisco Naval Shipyards. For almost all activities, fifty-year bone dose commitments are less than 0.15 rem from any annual period of exposure.

  10. Internal dose assessment of 238U contaminated soils based on in-vitro gastrointestinal protocol

    NASA Astrophysics Data System (ADS)

    Perama, Yasmin Mohd Idris; Rashid, Nur Shahidah Abdul; Majid, Amran Ab.; Siong, Khoo Kok

    2017-01-01

    Human exposure to natural radioactive uranium has been a great interest as more industrial rapidly growing contributes to radiation risks. The aim of this case study was to determine the internal dose in humans incorporated with ingestion of 238U contaminated soils. A gastrointestinal analogue test was employed to simulate the human digestive tract. In-vitro approach via German DIN 19738 model was developed in order to estimate the internal exposure of 238U due to ingestion of different types of soils. Synthetic gastrointestinal fluids assay via in-vitro method were produced to determine the concentration of 238U in various soils using ICP-MS. Based on the results, concentration of 238U in BRIS, laterite, peat and alluvium soils were in ranged between (0.0061 ± 0.0057 - 0.0488 ± 0.0148) ppm and (0.0005 ± 0.0004 - 0.0046 ± 0.0007) ppm in gastric and gastrointestinal phase respectively. Types of soil compositions and pH medium were some of the factors that influence mobilization and solubility of 238U contaminanted soil into the digestive juices that resembles human gastrointestinal tract. For the purpose of internal dose assessment, the committed efective dose from 238U intake in soils ranged between 1.237 × 10-11 - 9.8993 × 10-11 Sv y-1 for gastric phase and 1.0184 × 10-12 - 9.3294 × 10-12 Sv y-1 for gastric-intestinal phase. The internal dose measurements from this study were much lower from the recommended values. Hence, ingestion of 238U contaminated soils would not be expected to pose major health risk to humans.

  11. Application of IDEAS guidelines: the IDEAS/IAEA intercomparison exercise on internal dose assessment.

    PubMed

    Hurtgen, C; Andrasi, A; Bailey, M R; Birchall, A; Blanchardon, E; Berkovski, V; Castellani, C M; Cruz-Suarez, R; Davis, K; Doerfel, H; Leguen, B; Malatova, I; Marsh, J; Zeger, J

    2007-01-01

    As part of the EU Fifth Framework Programme IDEAS project 'General Guidelines for the Evaluation of Incorporation Monitoring Data', and in collaboration with the International Atomic Energy Agency, a new intercomparison exercise for the assessment of doses from intakes of radionuclides was organised. Several cases were selected, to cover a wide range of practices in the nuclear fuel cycle and medical applications. The cases were: (1) acute intake of HTO, (2) acute inhalation of the fission products 137Cs and 90Sr, (3) acute inhalation of 60Co, (4) repeated intakes of 131I, (5) intake of enriched uranium and (6) single intake of Pu isotopes and 241Am. This intercomparison exercise especially focused on the effect of the Guidelines proposed by the IDEAS project for harmonisation of internal dosimetry.

  12. Revised series of stylized anthropometric phantoms for internal and external radiation dose assessment

    NASA Astrophysics Data System (ADS)

    Han, Eunyoung

    At present, the dosimetry systems of both the International Commission on Radiological Protection, and the Society of Nuclear Medicine's Medical Internal Radiation Dose Committee utilize a series of stylized or mathematical anthropometric models of patient anatomy developed in 1987 at the Oak Ridge National Laboratory (ORNL). In this study, substantial revisions to the ORNL phantom series are reported with tissue compositions, tissue densities, and organ masses adjusted to match their most recent values in the literature. In addition, both the ICRP and MIRD systems of internal dosimetry implicitly consider that electron and beta-particle energy emitted within the source organs of the patient are fully deposited within these organs. With the development of the revised ORNL phantom series, three additional applications were explored as part of this dissertation research. First, the phantoms were used in combination to assess external radiation exposures to family members caring or interacting with patients released from the hospital following radionuclide therapy with I-131. Values of family member effective dose are then compared to values obtained using NRC guidance and based on a simple point-source methodology which ignores the effects of photon attenuation and scatter within both the source individual (patient) and the target individual (family member). Second, the anatomical structures of the extrathoracic airways and thoracic airways (exclusive of the lungs themselves) have been included in the entire revised ORNL phantom series of pediatric individuals. Values of cross-region photon dose are explored for use in radioactive aerosol inhalation exposures to members of the general public, and comparisons are made to values given by the ICRP in which surrogate organ assignments were made in the absence of explicit models of these airways. Finally, the revised ORNL phantoms of the adult male and adult female are used to determine internal photon exposures to

  13. Internal dose assessments: uncertainty studies and update of ideas guidelines and databases within CONRAD project.

    PubMed

    Marsh, J W; Castellani, C M; Hurtgen, C; Lopez, M A; Andrasi, A; Bailey, M R; Birchall, A; Blanchardon, E; Desai, A D; Dorrian, M-D; Doerfel, H; Koukouliou, V; Luciani, A; Malatova, I; Molokanov, A; Puncher, M; Vrba, T

    2008-01-01

    The work of Task Group 5.1 (uncertainty studies and revision of IDEAS guidelines) and Task Group 5.5 (update of IDEAS databases) of the CONRAD project is described. Scattering factor (SF) values (i.e. measurement uncertainties) have been calculated for different radionuclides and types of monitoring data using real data contained in the IDEAS Internal Contamination Database. Based upon this work and other published values, default SF values are suggested. Uncertainty studies have been carried out using both a Bayesian approach as well as a frequentist (classical) approach. The IDEAS guidelines have been revised in areas relating to the evaluation of an effective AMAD, guidance is given on evaluating wound cases with the NCRP wound model and suggestions made on the number and type of measurements required for dose assessment.

  14. Internal dose assessment of 210Po using biokinetic modeling and urinary excretion measurement

    PubMed Central

    Gerstmann, Udo; Giussani, Augusto; Oeh, Uwe; Paretzke, Herwig G.

    2007-01-01

    The mysterious death of Mr. Alexander Litvinenko who was most possibly poisoned by Polonium-210 (210Po) in November 2006 in London attracted the attention of the public to the kinetics, dosimetry and the risk of this high radiotoxic isotope in the human body. In the present paper, the urinary excretion of seven persons who were possibly exposed to traces of 210Po was monitored. The values measured in the GSF Radioanalytical Laboratory are in the range of natural background concentration. To assess the effective dose received by those persons, the time-dependence of the organ equivalent dose and the effective dose after acute ingestion and inhalation of 210Po were calculated using the biokinetic model for polonium (Po) recommended by the International Commission on Radiological Protection (ICRP) and the one recently published by Leggett and Eckerman (L&E). The daily urinary excretion to effective dose conversion factors for ingestion and inhalation were evaluated based on the ICRP and L&E models for members of the public. The ingestion (inhalation) effective dose per unit intake integrated over one day is 1.7 × 10−8 (1.4 × 10−7) Sv Bq−1, 2.0 × 10−7 (9.6 × 10−7) Sv Bq−1 over 10 days, 5.2 × 10−7 (2.0 × 10−6) Sv Bq−1 over 30 days and 1.0 × 10−6 (3.0 × 10−6) Sv Bq−1 over 100 days. The daily urinary excretions after acute ingestion (inhalation) of 1 Bq of 210Po are 1.1 × 10−3 (1.0 × 10−4) on day 1, 2.0 × 10−3 (1.9 × 10−4) on day 10, 1.3 × 10−3 (1.7 × 10−4) on day 30 and 3.6 × 10−4 (8.3 × 10−5) Bq d−1 on day 100, respectively. The resulting committed effective doses range from 2.1 × 10−3 to 1.7 × 10−2 mSv by an assumption of ingestion and from 5.5 × 10−2 to 4.5 × 10−1 mSv by inhalation. For the case of Mr. Litvinenko, the mean organ absorbed dose as a function of time was calculated using both the above stated models. The red bone marrow, the

  15. Biomarkers of internal dose for the assessment of environmental exposure to benzene.

    PubMed

    Lovreglio, Piero; D'Errico, Maria Nicolà; Fustinoni, Silvia; Drago, Ignazio; Barbieri, Anna; Sabatini, Laura; Carrieri, Mariella; Apostoli, Pietro; Soleo, Leonardo

    2011-10-01

    The urinary excretion of t,t-muconic acid (t,t-MA), S-phenylmercapturic acid (SPMA) and urinary benzene and the influence of a smoking habit and of exposure to urban traffic on the urinary excretion of these biomarkers were investigated in 137 male adults from the general population. All subjects were not occupationally exposed to benzene and resident in two cities in Puglia (Southern-Italy). Environmental exposure to benzene was measured using passive personal samplers. The biomarkers t,t-MA, SPMA and urinary benzene were determined in urine samples collected from each subject at the end of the environmental sampling. The percentage of cases above the limit of detection was higher for SPMA and urinary benzene in smokers than in non-smokers, and for airborne benzene and urinary benzene in subjects exposed to urban traffic. Airborne benzene was correlated with the time spent in urban traffic during the environmental sampling. Among the biomarkers, urinary benzene was found to be correlated with airborne benzene only in non-smokers, and with the time spent in urban traffic, both in smokers and non-smokers considered together, and in non-smokers only. Finally, multiple regression analysis showed that the urinary excretion of all the biomarkers was dependent on the number of cigarettes smoked per day and, for urinary benzene, also on the time spent in urban traffic. In conclusion, urinary benzene seems to be a more valid biomarker than t,t-MA and SPMA to assess environmental exposure to extremely low concentrations of benzene. Cigarette smoking prevailed over traffic exhaust fumes in determining the internal dose of benzene.

  16. Practical applications of internal dose calculations

    SciTech Connect

    Carbaugh, E.H.

    1994-06-01

    Accurate estimates of intake magnitude and internal dose are the goal for any assessment of an actual intake of radioactivity. When only one datum is available on which to base estimates, the choices for internal dose assessment become straight-forward: apply the appropriate retention or excretion function, calculate the intake, and calculate the dose. The difficulty comes when multiple data and different types of data become available. Then practical decisions must be made on how to interpret conflicting data, or how to adjust the assumptions and techniques underlying internal dose assessments to give results consistent with the data. This article describes nine types of adjustments which can be incorporated into calculations of intake and internal dose, and then offers several practical insights to dealing with some real-world internal dose puzzles.

  17. An adaptable internal dose model for risk assessment of dietary and soil dioxin exposures in young children.

    PubMed

    Kerger, Brent D; Leung, Hon-Wing; Scott, Paul K; Paustenbach, Dennis J

    2007-11-01

    An adaptable model is presented for assessing the blood lipid concentrations of polychlorodibenzodioxins and polychlorodibenzofurans (PCDD/Fs) from dietary (breast milk, formula, milk, and other foods) and soil pathway exposures (soil ingestion and dermal contact) utilizing age-specific exposure and intake estimates for young children. The approach includes a simple one-compartment (adipose volume) toxicokinetic model that incorporates empirical data on age-dependent half-lives and bioavailability of PCDD/F congeners, child body size and intake rates, and recent data on breast milk and food dioxin levels. Users can enter site-specific soil concentration data on 2,3,7,8-chlorinated PCDD/F congeners for specific assessment of body burden changes from soil pathways in combination with background dietary exposures from birth through age 7 years. The model produces a profile of the estimated PCDD/F concentration in blood lipid (in World Health Organization 1998 dioxin toxic equivalents) versus time for a child from birth through age 7 years. The peak and time-weighted average (TWA) internal dose (defined as blood lipid dioxin toxic equivalents) for a variety of specific child exposure assumptions can then be compared to safe internal dose benchmarks for risk assessment purposes, similar to an approach taken by United States Environmental Protection Agency for assessing child lead exposures. We conclude that this adaptable toxicokinetic model can provide a more comprehensive assessment of potential health risks of PCDD/Fs to children because it integrates recent empirical findings on PCDD/F kinetics in humans and allows users to assess contributions from varied dietary and site-specific environmental exposure assumptions.

  18. Internal dose assessment for 211At α-emitter in isotonic solution as radiopharmaceutical

    NASA Astrophysics Data System (ADS)

    Yuminov, O. A.; Fotina, O. V.; Priselkova, A. B.; Tultaev, A. V.; Platonov, S. Yu.; Eremenko, D. O.; Drozdov, V. A.

    2003-12-01

    The functional fitness of the α-emitter 211At for radiotherapy of the thyroid gland cancer is evaluated. Radiation doses are calculated using the MIRD method and previously obtained pharmacokinetic data for 211At in isotonic solution and for 123I as sodium iodide. Analysis of the 211At radiation dose to the thyroid gland suggests that this radiopharmaceutical may be predominantly used for the treatment of the thyroid cancer.

  19. Improvement of the measuring equipment used in the assessment of internal doses in emergency situations.

    PubMed

    Muikku, M; Rahola, T

    2007-01-01

    Emergency response plans have long been focused on accidents at nuclear power plants. Recently, the malevolent use of radiation aimed at creating disruption in the society has been considered as a possible threat. In this kind of emergency situations casualties will most likely be members of the public and the number of affected people can vary from a few to mass casualties. There is an evident need for rapid measurements of large groups of internally contaminated people. Radiation and Nuclear Safety Authority (STUK) in Finland has obtained new monitors for thyroid and simple whole-body measurements in field conditions as a part of the continuous improving of emergency preparedness. The new monitors consist of a NaI(Tl) detector and a control unit. The monitors work as spectrometers allowing real-time spectrum analysis in the field.

  20. (32)P measurment of urine samples and internal dose assessment for radiation workers in life science laboratories.

    PubMed

    Yoon, S; Pak, M-J; Park, S; Yoo, J; Ha, W-H; Jang, H-K; Kim, J K

    2014-12-01

    (32)P measurements of urine samples and internal dose assessments were conducted for workers in life science laboratories. A procedure for sample pre-treatment was established and validation was performed to exclude interference and to detect (32)P levels accurately. The detection conditions for Cherenkov radiation were evaluated and the accuracy of Cherenkov radiation measurements validated. The analytical and measurement procedures were applied to urine samples collected from 11 workers from life sciences laboratories. The results of the measurements generally indicated very low background radiation levels, but daily urine samples from two workers were above the minimum detectable activity. The (32)P concentrations for two of the workers were 29.3  ±  10.4 Bq•d(-1) and 24.1  ±  11.8 Bq•d(-1), respectively, at intake levels of 4.12 kBq and 2.61 kBq. The effective doses for these two workers were 4.6 μSv and 2.9 μSv. Overall, the results indicate very low levels of radioactivity, except for cases related to specific working conditions.

  1. A mobile bioassay laboratory for the assessment of internal doses based on in vivo and in vitro measurements.

    PubMed

    Dantas, B M; Lucena, E A; Dantas, A L A; Santos, M S; Julião, L Q C; Melo, D R; Sousa, W O; Fernandes, P C; Mesquita, S A

    2010-10-01

    Internal exposures may occur in nuclear power plants, radioisotope production, and in medicine and research laboratories. Such practices require quick response in case of accidents of a wide range of magnitudes. This work presents the design and calibration of a mobile laboratory for the assessment of accidents involving workers and the population as well as for routine monitoring. The system was set up in a truck with internal dimensions of 3.30 m × 1.60 m × 1.70 m and can identify photon emitters in the energy range of 100-3,000 keV in the whole body, organs, and in urine. A thyroid monitor consisting of a lead-collimated NaI(Tl)3" × 3" (7.62 × 7.62 cm) detector was calibrated with a neck-thyroid phantom developed at the IRD (Instituto de Radioproteção e Dosimetria). Whole body measurements were performed with a NaI(Tl)8" × 4" (20.32 × 10.16 cm) detector calibrated with a plastic-bottle phantom. Urine samples were measured with another NaI(Tl) 3" × 3" (7.62 × 7.62 cm) detector set up in a steel support. Standard solutions were provided by the National Laboratory for Metrology of Ionizing Radiation of the IRD. Urine measurements are based on a calibration of efficiency vs. energy for standard volumes. Detection limits were converted to minimum committed effective doses for the radionuclides of interest using standard biokinetic and dosimetric models in order to evaluate the applicability and limitations of the system. Sensitivities for high-energy activation and fission products show that the system is suitable for use in emergency and routine monitoring of individuals under risk of internal exposure by such radionuclides.

  2. Use of international data sets to evaluate and validate pathway assessment models applicable to exposure and dose reconstruction at DOE facilities. Progress report, August 1993--January 1994

    SciTech Connect

    Hendrickson, S.M.; Hoffman, F.O.

    1994-03-01

    This project, ``Use of International Data Sets to Evaluate and Validate Pathway Assessment Models Applicable to Exposure and Dose Reconstruction at DOE Facilities,`` grew out of several activities being conducted by the Principal Investigator Dr. F Owen Hoffman. One activity was originally part of the Chernobyl Studies Project and began as Task 7.1D, ``Internal Dose From Direct Contamination of Terrestrial Food Sources.`` The objective of Task 7.1D was to (1) establish a collaborative US USSR effort to improve and validate our methods of forecasting doses and dose commitments from the direct contamination of food sources, and (2) perform experiments and validation studies to improve our ability to predict rapidly and accurately the long-term internal dose from the contamination of agricultural soil. The latter was to include the consideration of remedial measures to block contamination of food grown on contaminated soil. The current objective of this project is to evaluate and validate pathway-assessment models applicable to exposure and dose reconstruction at DOE facilities through use of international data sets. This project incorporates the activity of Task 7.1D into a multinational effort to evaluate data used for the prediction of radionuclide transfer through agricultural and aquatic systems to humans. It also includes participation in two multinational studies, BIOMOVS (BIOspheric MOdel Validation Study) with the Swedish National Institute for Radiation Protection and VAMP (VAlidation of Model Predictions) with the International Atomic Energy Agency, that address testing the performance of models of radionuclide transport through foodchains.

  3. Mayak Worker Dosimetry System 2008 (MWDS-2008): assessment of internal dose from measurement results of plutonium activity in urine.

    PubMed

    Khokhryakov, Victor V; Khokhryakov, Valentin F; Suslova, Klara G; Vostrotin, Vadim V; Vvedensky, Vladimir E; Sokolova, Alexandra B; Krahenbuhl, Melinda P; Birchall, Alan; Miller, Scott C; Schadilov, Anatoly E; Ephimov, Alexander V

    2013-04-01

    A new modification of the prior human lung compartment plutonium model, Doses-2005, has been described. The modified model was named "Mayak Worker Dosimetry System-2008" (MWDS-2008). In contrast to earlier models developed for workers at the Mayak Production Association (Mayak PA), the new model more correctly describes plutonium biokinetics and metabolism in pulmonary lymph nodes. The MWDS-2008 also provides two sets of doses estimates: one based on bioassay data and the other based on autopsy data, where available. The algorithm of internal dose calculation from autopsy data will be described in a separate paper. Results of comparative analyses of Doses-2005 and MWDS-2008 are provided. Perspectives on the further development of plutonium dosimetry are discussed.

  4. Utirik Atoll Dose Assessment

    SciTech Connect

    Robison, W.L.; Conrado, C.L.; Bogen, K.T

    1999-10-06

    On March 1, 1954, radioactive fallout from the nuclear test at Bikini Atoll code-named BRAVO was deposited on Utirik Atoll which lies about 187 km (300 miles) east of Bikini Atoll. The residents of Utirik were evacuated three days after the fallout started and returned to their atoll in May 1954. In this report we provide a final dose assessment for current conditions at the atoll based on extensive data generated from samples collected in 1993 and 1994. The estimated population average maximum annual effective dose using a diet including imported foods is 0.037 mSv y{sup -1} (3.7 mrem y{sup -1}). The 95% confidence limits are within a factor of three of their population average value. The population average integrated effective dose over 30-, 50-, and 70-y is 0.84 mSv (84, mrem), 1.2 mSv (120 mrem), and 1.4 mSv (140 mrem), respectively. The 95% confidence limits on the population-average value post 1998, i.e., the 30-, 50-, and 70-y integral doses, are within a factor of two of the mean value and are independent of time, t, for t > 5 y. Cesium-137 ({sup 137}Cs) is the radionuclide that contributes most of this dose, mostly through the terrestrial food chain and secondarily from external gamma exposure. The dose from weapons-related radionuclides is very low and of no consequence to the health of the population. The annual background doses in the U. S. and Europe are 3.0 mSv (300 mrem), and 2.4 mSv (240 mrem), respectively. The annual background dose in the Marshall Islands is estimated to be 1.4 mSv (140 mrem). The total estimated combined Marshall Islands background dose plus the weapons-related dose is about 1.5 mSv y{sup -1} (150 mrem y{sup -1}) which can be directly compared to the annual background effective dose of 3.0 mSv y{sup -1} (300 mrem y{sup -1}) for the U. S. and 2.4 mSv y{sup -1} (240 mrem y{sup -1}) for Europe. Moreover, the doses listed in this report are based only on the radiological decay of {sup 137}Cs (30.1 y half-life) and other

  5. Experimental assessment of absorbed dose to mineralized bone tissue from internal emitters: An electron paramagnetic resonance study

    SciTech Connect

    Desrosiers, M.F.

    1994-12-31

    EPR resonances attributable to radiation-induced centers in hydroxyapatite were not detectable in bone samples supplied by the USTUR. These centers are the basis for imaging and dose assessment. Presumable, the short range of the alpha particles emitted precluded the formation of appreciable amounts of hydroxyapatite centers. However, one bone sample did offer a suggestion of hydroxyapatite centers and newly-developed methods to extract this information will be pursued.

  6. Implications of the ICRP Task Group's proposed lung model for internal dose assessments in the mineral sands industry

    SciTech Connect

    James, A.C. ); Birchall, A. )

    1990-09-01

    The ICRP Task Group on Respiratory Tract Models for Radiological Projection is proposing a model to describe the deposition, clearance, retention and dosimetry of inhaled radionuclides for dose-intake calculations and interpretation of bioassay data. The deposition model takes into account new data on the regional deposition of aerosol particles in human lung and the inhalability of large particles. The clearance model treats clearance as competition between mechanical transport, which moves particles to the gastro-intestinal tract and lymph nodes, and the translocation of material to blood. This provides a realistic estimate of the amount of a given material (such as mineral sand) that is absorbed systemically, and its variation with aerosol size. The proposed dosimetry model takes into account the relative sensitivities of the various tissue components of the respiratory tract. A new treatment of dose received by epithelia in the tracheo-bronchiolar and extrathoracic regions is proposed. This paper outlines the novel features of the task group model, and then examines the impact that adoption of the model may have on the assessment of doses from occupational exposures to mineral sands and thoron progeny. 39 refs., 15 figs., 6 tabs.

  7. Polycyclic aromatic hydrocarbons at fire stations: firefighters' exposure monitoring and biomonitoring, and assessment of the contribution to total internal dose.

    PubMed

    Oliveira, Marta; Slezakova, Klara; Alves, Maria José; Fernandes, Adília; Teixeira, João Paulo; Delerue-Matos, Cristina; Pereira, Maria do Carmo; Morais, Simone

    2017-02-05

    This work characterizes levels of eighteen polycyclic aromatic hydrocarbons (PAHs) in the breathing air zone of firefighters during their regular work shift at eight Portuguese fire stations, and the firefighters' total internal dose by six urinary monohydroxyl metabolites (OH-PAHs). Total PAHs (ΣPAHs) concentrations varied widely (46.4-428ng/m(3)), mainly due to site specificity (urban/rural) and characteristics (age and layout) of buildings. Airborne PAHs with 2-3 rings were the most abundant (63.9-95.7% ΣPAHs). Similarly, urinary 1-hydroxynaphthalene and 1-hydroxyacenaphthene were the predominant metabolites (66-96% ΣOH-PAHs). Naphthalene contributed the most to carcinogenic ΣPAHs (39.4-78.1%) in majority of firehouses; benzo[a]pyrene, the marker of carcinogenic PAHs, accounted with 1.5-10%. Statistically positive significant correlations (r≥0.733, p≤0.025) were observed between ΣPAHs and urinary ΣOH-PAHs for firefighters of four fire stations suggesting that, at these sites, indoor air was their major exposure source of PAHs. Firefighter's personal exposure to PAHs at Portuguese fire stations were well below the existent occupational exposure limits. Also, the quantified concentrations of post-shift urinary 1-hydroxypyrene in all firefighters were clearly lower than the benchmark level (0.5μmol/mol) recommended by the American Conference of Governmental Industrial Hygienists.

  8. LESSONS LEARNED FROM THE EURADOS SURVEY ON INDIVIDUAL MONITORING DATA AND INTERNAL DOSE ASSESSMENTS OF FOREIGNERS EXPOSED IN JAPAN FOLLOWING THE FUKUSHIMA DAIICHI NPP ACCIDENT.

    PubMed

    Lopez, M A; Fojtik, P; Franck, D; Osko, J; Gerstmann, U; Scholl, C; Lebacq, A L; Breustedt, B; Del Risco Norrlid, L

    2016-09-01

    European Radiation Dosimetry Group e.V. (EURADOS) survey on individual monitoring data and dose assessment has been carried out for 550 foreigners returning home after being exposed in Japan to intakes of radionuclides (mainly (131)I, (132)I, (132)Te, (134)Cs and (137)Cs) as a consequence of the Fukushima Daiichi NPP accident. In vivo and in vitro measurements were performed in their respective countries at an early stage after that accident. Intakes of radionuclides were detected in 208 persons from Europe and Canada, but the committed effective dose E(50) was below the annual dose limit for the public (<1 mSv) in all the cases. Lessons learned from this EURADOS survey are presented here regarding not only internal dosimetry issues, but also the management of the emergency situation, the perception of the risk of health effects due to radiation and the communication with exposed persons who showed anxiety and lack of trust in monitoring data and dose assessments. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. THE CHALLENGE OF CIEMAT INTERNAL DOSIMETRY SERVICE FOR ACCREDITATION ACCORDING TO ISO/IEC 17025 STANDARD, FOR IN VIVO AND IN VITRO MONITORING AND DOSE ASSESSMENT OF INTERNAL EXPOSURES.

    PubMed

    Lopez, M A; Martin, R; Hernandez, C; Navarro, J F; Navarro, T; Perez, B; Sierra, I

    2016-09-01

    The accreditation of an Internal Dosimetry Service (IDS) according to ISO/IEC 17025 Standard is a challenge. The aim of this process is to guarantee the technical competence for the monitoring of radionuclides incorporated in the body and for the evaluation of the associated committed effective dose E(50). This publication describes the main accreditation issues addressed by CIEMAT IDS regarding all the procedures involving good practice in internal dosimetry, focussing in the difficulties to ensure the traceability in the whole process, the appropriate calculation of detection limit of measurement techniques, the validation of methods (monitoring and dose assessments), the description of all the uncertainty sources and the interpretation of monitoring data to evaluate the intake and the committed effective dose. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Internal dose following a major nuclear war

    SciTech Connect

    Peterson, K.R.; Shapiro, C.S. )

    1992-01-01

    The PATHWAY model results were used, in conjunction with a hypothetical major nuclear attack on the U.S., to arrive at the ratio of internal to external dose for humans from early (48 h) fallout. Considered were the four nuclides (137Cs, 89Sr, 90Sr, 131I) that account for most of the reconstructed whole-body committed equivalent dose from internal radiation in people who lived downwind of the Nevada Test Site during atmospheric tests. Effects of climate perturbations (the 'nuclear winter' effect) on food crops were considered. These could increase internal dose estimates, depending on the severity of the climate perturbations. Internal and external doses to humans for 10 locations within the U.S. have been calculated, with varying local conditions and varying assumption about their shelters. The estimated 50-y internal dose commitment ranged from 0.0-0.17 Sv, the 48-h external dose from 0.15-4.6 Sv. The resultant ratios of internal to external committed dose received in the first months (until food transport was restored) varied from less than 0.01 to about 0.2. In all cases examined, the total dose from early fallout was found to be dominated by the external dose.

  11. Internal dose following a major nuclear war.

    PubMed

    Peterson, K R; Shapiro, C S

    1992-01-01

    The PATHWAY model results were used, in conjunction with a hypothetical major nuclear attack on the U.S., to arrive at the ratio of internal to external dose for humans from early (48 h) fallout. Considered were the four nuclides (137Cs, 89Sr, 90Sr, 131I) that account for most of the reconstructed whole-body committed equivalent dose from internal radiation in people who lived downwind of the Nevada Test Site during atmospheric tests. Effects of climate perturbations (the "nuclear winter" effect) on food crops were considered. These could increase internal dose estimates, depending on the severity of the climate perturbations. Internal and external doses to humans for 10 locations within the U.S. have been calculated, with varying local conditions and varying assumption about their shelters. The estimated 50-y internal dose commitment ranged from 0.0-0.17 Sv, the 48-h external dose from 0.15-4.6 Sv. The resultant ratios of internal to external committed dose received in the first months (until food transport was restored) varied from less than 0.01 to about 0.2. In all cases examined, the total dose from early fallout was found to be dominated by the external dose.

  12. Integrated retrospective radiation dose assessment.

    PubMed

    Goldman, M

    1997-01-01

    Radiation dose reconstruction is used to estimate exposure to radiation that has occurred externally, e.g., from an atomic bomb, or internally, e.g., from radionuclide ingestion. This commentary reviews techniques for biological dosimetry that have been developed to estimate radiation doses from internal exposures, but which can also be used to estimate external exposures. The author argues for increased development and use of these biological tools.

  13. REMEDIATION FACILITY WORKER DOSE ASSESSMENT

    SciTech Connect

    V. Arakali; E. Faillace

    2004-02-27

    The purpose of this design calculation is to estimate radiation doses received by personnel in the Remediation Facility performing operations to receive, prepare, open, repair, recover, disposition, and correct off-normal and non-standard conditions with casks, canisters, spent nuclear fuel (SNF) assemblies, and waste packages (WP). The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation. The results of this calculation will be used to support the design of the Remediation Facility and provide occupational dose estimates for the License Application.

  14. Use of international data sets to evaluate and validate pathway assessment models applicable to exposure and dose reconstruction at DOE facilities. Progress report, March--May 1994

    SciTech Connect

    Anspaugh, L.R.; Hendrickson, S.M.; Hoffman, F.O.

    1994-06-01

    The project described in this report was the result of a Memorandum of Cooperation between the US and the former-USSR following the accident at the Chernobyl Nuclear Power Plant Unit 4. A joint program was established to improve the safety of nuclear power plants and to understand the implications of environmental releases. The task of Working Group 7 was ``to develop jointly methods to project rapidly the health effects of any future nuclear reactor accident.`` The current objective of this project is to evaluate and validate pathway-assessment models applicable to exposure and dose reconstruction at DOE facilities through use of international data sets. This project incorporates data used for the prediction of radionuclide transfer through agricultural and aquatic systems to humans. It also includes participation in two multinational studies, BIOMOVS (Biospheric Model Validation Study) with the Swedish National Institute for Radiation Protection and VAMP (Validation of Model Predictions) with the International Atomic Energy Agency, that address testing the performance of models of radionuclide transport through foodchains. In the future, this project will be considered separately from the Chernobyl Studies Project and the essential activities of former Task 7.1D will be folded within the broader umbrella of the BIOMOVS and VAMP projects. The Working Group Leader of Task 7.1D will continue to provide oversight for this project.

  15. Respirators, internal dose, and Oyster Creek

    SciTech Connect

    Michal, R.

    1996-06-01

    This article looks at the experience of Oyster Creek in relaxing the requirements for the use of respirators in all facets of plant maintenance, on the overall dose received by plant maintenance personnel. For Roger Shaw, director of radiological controls for three years at GPU Nuclear Corporation`s Oyster Creek nuclear plant the correct dose balance is determined on a job-by-job basis: Does the job require a respirator, which is an effective means of decreasing worker inhalation of airborne radioactive particles? Will wearing a respirator slow down a worker, consequently increasing whole body radiation exposure by prolonging the time spent in fields of high external radiation? How does respiratory protection affect worker safety and to what degree? While changes to the Nuclear Regulatory Commission`s 10CFR20 have updated the radiation protection requirements for the nuclear industry, certain of the revisions have been directed specifically at reducing worker dose, Shaw said. {open_quotes}It basically delineates that dose is dose,{close_quotes} Shaw said, {open_quotes}regardless of whether it is acquired externally or internally.{close_quotes} The revision of Part 20 changed the industry`s attitude toward internal dose, which had always been viewed negatively. {open_quotes}Internal dose was always seen as preventable by wearing respirators and by using engineering techniques such as ventilation control and decontamination,{close_quotes} Shaw said, {open_quotes}whereas external dose, although reduced where practical, was seen as a fact of the job.{close_quotes}

  16. Special Session on Internal Dose at HPS Meeting in Portland

    SciTech Connect

    Strom, Daniel J.

    2007-09-22

    In October 2006, the most recent of the usually quadrennial European internal dosimetry meetings was held in Montpellier, France. Based on questions and discussions at that meeting, Health Physics Society (HPS) Past President Ray Guilmette of Los Alamos National Laboratory (LANL) organized and cochaired with Keith Eckerman a special session onCurrent Topics in Internal Dose Assessment.” For a session scheduled on the last day of the Annual HPS Meeting in Portland, Oregon, one might not expect a huge turnout. However, the session was intense and riveting, with well over 100 people at the beginning, and perhaps 60 holding on until well after noon, after the official ending of the meeting. First, Guilmette invited six of our best and brightest in the internal dosimetry and dose reconstruction community. Then he challenged each to answer five questions on assessment or reconstruction of doses due to intakes of radionuclides: Who is the customer (for the dose assessment)? What are the rules and constraints for the dose assessment? What are the appropriate methods, models, and calculation techniques? What are the dose endpoints? How are uncertainties handled?

  17. AGING FACILITY WORKER DOSE ASSESSMENT

    SciTech Connect

    R.L. Thacker

    2005-03-24

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Aging Facility performing operations to transfer aging casks to the aging pads for thermal and logistical management, stage empty aging casks, and retrieve aging casks from the aging pads for further processing in other site facilities. Doses received by workers due to aging cask surveillance and maintenance operations are also included. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation. There are no Category 1 event sequences associated with the Aging Facility (BSC 2004 [DIRS 167268], Section 7.2.1). The results of this calculation will be used to support the design of the Aging Facility and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in Environmental and Nuclear Engineering.

  18. Fukushima simulation experiment: assessing the effects of chronic low-dose-rate internal 137Cs radiation exposure on litter size, sex ratio, and biokinetics in mice

    PubMed Central

    Nakajima, Hiroo; Yamaguchi, Yoshiaki; Yoshimura, Takashi; Fukumoto, Manabu; Todo, Takeshi

    2015-01-01

    To investigate the transgenerational effects of chronic low-dose-rate internal radiation exposure after the Fukushima Daiichi Nuclear Power Plant accident in Japan, 18 generations of mice were maintained in a radioisotope facility, with free access to drinking water containing 137CsCl (0 and 100 Bq/ml). The 137Cs distribution in the organs of the mice was measured after long-term ad libitum intake of the 137CsCl water. The litter size and the sex ratio of the group ingesting the 137Cs water were compared with those of the control group, for all 18 generations of mice. No significant difference was noted in the litter size or the sex ratio between the mice in the control group and those in the group ingesting the 137Cs water. The fixed internal exposure doses were ∼160 Bq/g and 80 Bq/g in the muscles and other organs, respectively. PMID:26825299

  19. Fukushima simulation experiment: assessing the effects of chronic low-dose-rate internal 137Cs radiation exposure on litter size, sex ratio, and biokinetics in mice.

    PubMed

    Nakajima, Hiroo; Yamaguchi, Yoshiaki; Yoshimura, Takashi; Fukumoto, Manabu; Todo, Takeshi

    2015-12-01

    To investigate the transgenerational effects of chronic low-dose-rate internal radiation exposure after the Fukushima Daiichi Nuclear Power Plant accident in Japan, 18 generations of mice were maintained in a radioisotope facility, with free access to drinking water containing (137)CsCl (0 and 100 Bq/ml). The (137)Cs distribution in the organs of the mice was measured after long-term ad libitum intake of the (137)CsCl water. The litter size and the sex ratio of the group ingesting the (137)Cs water were compared with those of the control group, for all 18 generations of mice. No significant difference was noted in the litter size or the sex ratio between the mice in the control group and those in the group ingesting the (137)Cs water. The fixed internal exposure doses were ∼160 Bq/g and 80 Bq/g in the muscles and other organs, respectively.

  20. Measurement of (131)I activity in thyroid of nuclear medical staff and internal dose assessment in a Polish nuclear medical hospital.

    PubMed

    Brudecki, K; Kowalska, A; Zagrodzki, P; Szczodry, A; Mroz, T; Janowski, P; Mietelski, J W

    2017-03-01

    This paper presents results of (131)I thyroid activity measurements in 30 members of the nuclear medicine personnel of the Department of Endocrinology and Nuclear Medicine Holy Cross Cancer Centre in Kielce, Poland. A whole-body spectrometer equipped with two semiconductor gamma radiation detectors served as the basic research instrument. In ten out of 30 examined staff members, the determined (131)I activity was found to be above the detection limit (DL = 5 Bq of (131)I in the thyroid). The measured activities ranged from (5 ± 2) Bq to (217 ± 56) Bq. The highest activities in thyroids were detected for technical and cleaning personnel, whereas the lowest values were recorded for medical doctors. Having measured the activities, an attempt has been made to estimate the corresponding annual effective doses, which were found to range from 0.02 to 0.8 mSv. The highest annual equivalent doses have been found for thyroid, ranging from 0.4 to 15.4 mSv, detected for a cleaner and a technician, respectively. The maximum estimated effective dose corresponds to 32% of the annual background dose in Poland, and to circa 4% of the annual limit for the effective dose due to occupational exposure of 20 mSv per year, which is in compliance with the value recommended by the International Commission on Radiological Protection.

  1. International Arctic Seas Assessment Project.

    PubMed

    Sjöblom, K L; Salo, A; Bewers, J M; Cooper, J; Dyer, R S; Lynn, N M; Mount, M E; Povinec, P P; Sazykina, T G; Schwarz, J; Scott, E M; Sivintsev, Y V; Tanner, J E; Warden, J M; Woodhead, D

    1999-09-30

    The International Atomic Energy Agency responded to the news that the former Soviet Union had dumped radioactive wastes in the shallow waters of the Arctic Seas, by launching the International Arctic Seas Assessment Project in 1993. The project had two objectives: to assess the risks to human health and to the environment associated with the radioactive wastes dumped in the Kara and Barents Seas; and to examine possible remedial actions related to the dumped wastes and to advise on whether they are necessary and justified. The current radiological situation in the Arctic waters was examined to assess whether there is any evidence for releases from the dumped waste. Potential future releases from the dumped wastes were predicted, concentrating on the high-level waste objects containing the major part of the radionuclide inventory of the wastes. Environmental transport of released radionuclides was modelled and the associated radiological impact on humans and the biota was assessed. The feasibility, costs and benefits of possible remedial measures applied to a selected high-level waste object were examined. Releases from identified dumped objects were found to be small and localised to the immediate vicinity of the dumping sites. Projected future annual doses to members of the public in typical local population groups were very small, less than 1 microSv--corresponding to a trivial risk. Projected future doses to a hypothetical group of military personnel patrolling the foreshore of the fjords in which wastes have been dumped were higher, up to 4 mSv/year, which still is of the same order as the average annual natural background dose. Moreover, since any of the proposed remedial actions were estimated to cost several million US$ to implement, remediation was not considered justified on the basis of potentially removing a collective dose of 10 man Sv. Doses calculated to marine fauna were insignificant, orders of magnitude below those at which detrimental effects on

  2. Critical Dose of Internal Organs Internal Exposure - 13471

    SciTech Connect

    Grigoryan, G.; Amirjanyan, A.; Grigoryan, N.

    2013-07-01

    The health threat posed by radionuclides has stimulated increased efforts to developed characterization on the biological behavior of radionuclides in humans in all ages. In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is assembling a set of age specific biokinetic models for environmentally important radioelements. Radioactive substances in the air, mainly through the respiratory system and digestive tract, is inside the body. Radioactive substances are unevenly distributed in various organs and tissues. Therefore, the degree of damage will depend not only on the dose of radiation have but also on the critical organ, which is the most accumulation of radioactive substances, which leads to the defeat of the entire human body. The main objective of radiation protection, to avoid exceeding the maximum permissible doses of external and internal exposure of a person to prevent the physical and genetic damage people. The maximum tolerated dose (MTD) of radiation is called a dose of radiation a person in uniform getting her for 50 years does not cause changes in the health of the exposed individual and his progeny. The following classification of critical organs, depending on the category of exposure on their degree of sensitivity to radiation: First group: the whole body, gonads and red bone marrow; Second group: muscle, fat, liver, kidney, spleen, gastrointestinal tract, lungs and lens of the eye; The third group: bone, thyroid and skin; Fourth group: the hands, forearms, feet. MTD exposure whole body, gonads and bone marrow represent the maximum exposures (5 rem per year) experienced by people in their normal activities. The purpose of this article is intended dose received from various internal organs of the radionuclides that may enter the body by inhalation, and gastrointestinal tract. The biokinetic model describes the time dependent distribution and excretion of different

  3. Science Teaching and International Assessments

    ERIC Educational Resources Information Center

    Bybee, Rodger W.

    2007-01-01

    This article is an introduction to the international assessments Programme for International Student Assessment (PISA) and the Trends in International Mathematics and Science Study (TIMSS) and a review of results from 2003. International comparisons, especially in the media, have elevated interest in science education and stimulated discussions…

  4. Influence of DTPA Treatment on Internal Dose Estimates.

    PubMed

    Davesne, Estelle; Blanchardon, Eric; Peleau, Bernadette; Correze, Philippe; Bohand, Sandra; Franck, Didier

    2016-06-01

    In case of internal contamination with plutonium materials, a treatment with diethylene triamine pentaacetic acid (DTPA) can be administered in order to reduce plutonium body burden and consequently avoid some radiation dose. DTPA intravenous injections or inhalation can start almost immediately after intake, in parallel with urinary and fecal bioassay sampling for dosimetric follow-up. However, urine and feces excretion will be significantly enhanced by the DTPA treatment. As internal dose is calculated from bioassay results, the DTPA effect on excretion has to be taken into account. A common method to correct bioassay data is to divide it by a factor representing the excretion enhancement under DTPA treatment by intravenous injection. Its value may be based on a nominal reference or observed after a break in the treatment. The aim of this study was to estimate the influence of this factor on internal dose by comparing the dose estimated using default or upper and lower values of the enhancement factor for 11 contamination cases. The observed upper and lower values of the enhancement factor were 18.7 and 63.0 for plutonium and 24.9 and 28.8 for americium. For americium, a default factor of 25 is proposed. This work demonstrates that the use of a default DTPA enhancement factor allows the determination of the magnitude of the contamination because dose estimated could vary by a factor of 2 depending on the value of the individual DTPA enhancement factor. In case of significant intake, an individual enhancement factor should be determined to obtain a more reliable dose assessment.

  5. VOXMAT: Hybrid Computational Phantom for Dose Assessment

    SciTech Connect

    Akkurt, Hatice; Eckerman, Keith F

    2007-01-01

    The Oak Ridge National Laboratory (ORNL) computational phantoms have been the standard for assessing the radiation dose due to internal and external exposure over the past three decades. In these phantoms, the body surface and each organ are approximated by mathematical equations; hence, some of the organs are not necessarily realistic in their shape. Over the past two decades, these phantoms have been revised and updated: some of the missing internal organs have been added and the locations of the existing organs have been revised (e.g., thyroid). In the original phantom, only three elemental compositions were used to describe all body tissues. Recently, the compositions of the organs have been updated based on ICRP-89 standards. During the past decade, phantoms based on CT scans were developed for use in dose assessment. Although their shapes are realistic, some computational challenges are noted; including increased computational times and increased memory requirements. For good spatial resolution, more than several million voxels are used to represent the human body. Moreover, when CT scans are obtained, the subject is in a supine position with arms at the side. In some occupational exposure cases, it is necessary to evaluate the dose with the arms and legs in different positions. It will be very difficult and inefficient to reposition the voxels defining the arms and legs to simulate these exposure geometries. In this paper, a new approach for computational phantom development is presented. This approach utilizes the combination of a mathematical phantom and a voxelized phantom for the representation of the anatomy.

  6. Ingestion of Nevada Test Site Fallout: Internal dose estimates

    SciTech Connect

    Whicker, F.W.; Kirchner, T.B.; Anspaugh, L.R.

    1996-10-01

    This paper summarizes individual and collective dose estimates for the internal organs of hypothetical yet representative residents of selected communities that received measurable fallout from nuclear detonations at the Nevada Test Site. The doses, which resulted from ingestion of local and regional food products contaminated with over 20 radionuclides, were estimated with use of the PATHWAY food-chain-transport model to provide estimates of central tendency and uncertainty. The thyroid gland received much higher doses than other internal organs and tissues. In a avery few cases, infants might have received thyroid doses in excess of 1 Gy, depending on location, diet, and timing of fallout. {sup 131}I was the primary thyroid dose contributor, and fresh milk was the main exposure pathway. With the exception of the thyroid, organ doses from the ingestion pathway were much smaller (<3%) than those from external gamma exposure to deposited fallout. Doses to residents living closest to the Nevada Test Site were contributed mainly by a few fallout events; doses to more distantly located people were generally smaller, but a greater number of events provided measurable contributions. The effectiveness of different fallout events in producing internal organ doses through ingestion varied dramatically with seasonal timing of the test, with maximum dose per unit fallout occurring for early summer depositions when milk cows were on pasture and fresh, local vegetables were used. Within specific communities, internal doses differed by age, sex, and lifestyle. Collective internal dose estimates for specific geographic areas are provided.

  7. Use of international data sets to evaluate and validate pathway assessment models applicable to exposure and dose reconstruction at DOE facilities. Monthly progress reports and final report, October--December 1994

    SciTech Connect

    Hoffman, F.O.

    1995-04-01

    The objective of Task 7.lD was to (1) establish a collaborative US-USSR effort to improve and validate our methods of forecasting doses and dose commitments from the direct contamination of food sources, and (2) perform experiments and validation studies to improve our ability to predict rapidly and accurately the long-term internal dose from the contamination of agricultural soil. At early times following an accident, the direct contamination of pasture and food stuffs, particularly leafy vegetation and grain, can be of great importance. This situation has been modeled extensively. However, models employed then to predict the deposition, retention and transport of radionuclides in terrestrial environments employed concepts and data bases that were more than a decade old. The extent to which these models have been tested with independent data sets was limited. The data gathered in the former-USSR (and elsewhere throughout the Northern Hemisphere) offered a unique opportunity to test model predictions of wet and dry deposition, agricultural foodchain bioaccumulation, and short- and long-term retention, redistribution, and resuspension of radionuclides from a variety of natural and artificial surfaces. The current objective of this project is to evaluate and validate pathway-assessment models applicable to exposure and dose reconstruction at DOE facilities through use of international data sets. This project incorporates the activity of Task 7.lD into a multinational effort to evaluate models and data used for the prediction of radionuclide transfer through agricultural and aquatic systems to humans. It also includes participation in two studies, BIOMOVS (BIOspheric MOdel Validation Study) with the Swedish National Institute for Radiation Protection and VAMP (VAlidation of Model Predictions) with the International Atomic Energy Agency, that address testing the performance of models of radionuclide transport through foodchains.

  8. Assessing intern handover processes.

    PubMed

    Habicht, Robert; Block, Lauren; Silva, Kathryn Novello; Oliver, Nora; Wu, Albert; Feldman, Leonard

    2016-06-01

    New standards for resident work hours set in 2011 changed the landscape of patient care in teaching hospitals, and resulted in new challenges for US residency training programmes to overcome. One such challenge was a dramatic increase in the number of patient handovers performed by residents. As a result, there is a renewed focus for clinical teachers to develop educational strategies to optimise the patient handover process and improve the quality of patient care and safety. In order to investigate current gaps in resident handovers, we examined the handover processes performed by medicine interns at two academic medical centres in Baltimore, Maryland, USA. We used trained observers to collect data on whether handovers were conducted face to face, with questions asked, in private locations, with written documentation, and without distractions or interruptions. Results were analysed using chi-square tests, and adjusted for clustering at the observer and intern levels. Interns successfully conducted handovers face to face (99.5%), asked questions (85.3%), used private locations (91%), included written handover documentation (95.8%) and did not experience distractions for the majority of the time (87.7%); however, interruptions were pervasive, occurring 41.3 per cent of the time. In order to investigate current gaps in resident handovers, we examined the handover processes performed by medicine interns Interns conducted patient handovers face to face, with questions asked, in private locations, with written documentation and without distractions the majority of the time; however, interruptions during the handover process were common. Exploring gaps at the individual programme level is a critical first step to develop effective teaching strategies to optimise handovers in residency. © 2015 John Wiley & Sons Ltd.

  9. Dose rate assessment in tooth enamel

    NASA Astrophysics Data System (ADS)

    Wieser, A.; Göksu, H. Y.; Regulla, D. F.; Vogenauer, A.

    A mammoth found in the southern part of Germany was dated by ESR spectroscopy. This dating method is based on the measurement of the accumulated dose in tooth enamel and assessment of the annual dose. The accumulated dose is obtained from the radiation induced ESR signal at g = 2.0018 of the enamel. The annual dose was first determined by measuring the 238U, 232Th and 40K content of the tooth and of the surrounding soil. As a crosscheck, the dose rate from the tooth was measured by inserting TL dosimeters in the dentine and storing them at 'zero' background in a salt mine. The cosmic dose rate and the gamma dose rate from the soil was evaluated from TL dosimeters buried at the excavation site. The results are discussed with respect to the applicability of ESR dating on teeth.

  10. Biodosimetry and assessment of radiation dose

    PubMed Central

    Crespo, Rafael Herranz; Domene, Mercedes Moreno; Rodríguez, María Jesús Prieto

    2011-01-01

    Aim When investigating radiation accidents, it is very important to determine the exposition dose to the individuals. In the case of exposures over 1 Gy, clinicians may expect deterministic effects arising the following weeks and months, in these cases dose estimation will help physicians in the planning of therapy. Nevertheless, for doses below 1 Gy, biodosimetry data are important due to the risk of developing late stochastic effects. Finally, some accidental overexposures are lack of physical measurements and the only way of quantifying dose is by biological dosimetry. Background The analysis of chromosomal aberrations by different techniques is the most developed method of quantifying dose to individuals exposed to ionising radiations.1,2 Furthermore, the analysis of dicentric chromosomes observed in metaphases from peripheral lymphocytes is the routine technique used in case of acute exposures to assess radiation doses. Materials and methods Solid stain of chromosomes is used to determine dicentric yields for dose estimation. Fluorescence in situ hybridization (FISH) for translocations analysis is used when delayed sampling or suspected chronically irradiation dose assessment. Recommendations in technical considerations are based mainly in the IAEA Technical Report No. 405.2 Results Experience in biological dosimetry at Gregorio Marañón General Hospital is described, including own calibration curves used for dose estimation, background studies and real cases of overexposition. Conclusion Dose assessment by biological dosimeters requires a large previous standardization work and a continuous update. Individual dose assessment involves high qualification professionals and its long time consuming, therefore requires specific Centres. For large mass casualties cooperation among specialized Institutions is needed. PMID:24376970

  11. CANISTER HANDLING FACILITY WORKER DOSE ASSESSMENT

    SciTech Connect

    D.T. Dexheimer

    2004-02-27

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Canister Handling Facility (CHF) performing operations to receive transportation casks, transfer wastes, prepare waste packages, perform associated equipment maintenance. The specific scope of work contained in this calculation covers individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation. The results of this calculation will be used to support the design of the CHF and provide occupational dose estimates for the License Application.

  12. Considerations of beta and electron transport in internal dose calculations

    SciTech Connect

    Bolch, W.E.; Poston, J.W. Sr.

    1990-12-01

    Ionizing radiation has broad uses in modern science and medicine. These uses often require the calculation of energy deposition in the irradiated media and, usually, the medium of interest is the human body. Energy deposition from radioactive sources within the human body and the effects of such deposition are considered in the field of internal dosimetry. In July of 1988, a three-year research project was initiated by the Nuclear Engineering Department at Texas A M University under the sponsorship of the US Department of Energy. The main thrust of the research was to consider, for the first time, the detailed spatial transport of electron and beta particles in the estimation of average organ doses under the Medical Internal Radiation Dose (MIRD) schema. At the present time (December of 1990), research activities are continuing within five areas. Several are new initiatives begun within the second or third year of the current contract period. They include: (1) development of small-scale dosimetry; (2) development of a differential volume phantom; (3) development of a dosimetric bone model; (4) assessment of the new ICRP lung model; and (5) studies into the mechanisms of DNA damage. A progress report is given for each of these tasks within the Comprehensive Report. In each case, preliminary results are very encouraging and plans for further research are detailed within this document.

  13. Considerations of beta and electron transport in internal dose calculations

    SciTech Connect

    Bolch, W.E.; Poston, J.W. Sr. . Dept. of Nuclear Engineering)

    1990-12-01

    Ionizing radiation has broad uses in modern science and medicine. These uses often require the calculation of energy deposition in the irradiated media and, usually, the medium of interest is the human body. Energy deposition from radioactive sources within the human body and the effects of such deposition are considered in the field of internal dosimetry. In July of 1988, a three-year research project was initiated by the Nuclear Engineering Department at Texas A M University under the sponsorship of the US Department of Energy. The main thrust of the research was to consider, for the first time, the detailed spatial transport of electron and beta particles in the estimation of average organ doses under the Medical Internal Radiation Dose (MIRD) schema. At the present time (December of 1990), research activities are continuing within five areas. Several are new initiatives begun within the second or third year of the current contract period. They include: (1) development of small-scale dosimetry; (2) development of a differential volume phantom; (3) development of a dosimetric bone model; (4) assessment of the new ICRP lung model; and (5) studies into the mechanisms of DNA damage. A progress report is given for each of these tasks within the Comprehensive Report. In each use, preliminary results are very encouraging and plans for further research are detailed within this document. 22 refs., 13 figs., 1 tab.

  14. An updated dose assessment for Rongelap Island

    SciTech Connect

    Robison, W.L.; Conrado, C.L.; Bogen, K.T.

    1994-07-01

    We have updated the radiological dose assessment for Rongelap Island at Rongelap Atoll using data generated from field trips to the atoll during 1986 through 1993. The data base used for this dose assessment is ten fold greater than that available for the 1982 assessment. Details of each data base are presented along with details about the methods used to calculate the dose from each exposure pathway. The doses are calculated for a resettlement date of January 1, 1995. The maximum annual effective dose is 0.26 mSv y{sup {minus}1} (26 mrem y{sup {minus}1}). The estimated 30-, 50-, and 70-y integral effective doses are 0.0059 Sv (0.59 rem), 0.0082 Sv (0.82 rem), and 0.0097 Sv (0.97 rem), respectively. More than 95% of these estimated doses are due to 137-Cesium ({sup 137}Cs). About 1.5% of the estimated dose is contributed by 90-Strontium ({sup 90}Sr), and about the same amount each by 239+240-Plutonium ({sup 239+240}PU), and 241-Americium ({sup 241}Am).

  15. Assessing dose rate distributions in VMAT plans

    NASA Astrophysics Data System (ADS)

    Mackeprang, P.-H.; Volken, W.; Terribilini, D.; Frauchiger, D.; Zaugg, K.; Aebersold, D. M.; Fix, M. K.; Manser, P.

    2016-04-01

    Dose rate is an essential factor in radiobiology. As modern radiotherapy delivery techniques such as volumetric modulated arc therapy (VMAT) introduce dynamic modulation of the dose rate, it is important to assess the changes in dose rate. Both the rate of monitor units per minute (MU rate) and collimation are varied over the course of a fraction, leading to different dose rates in every voxel of the calculation volume at any point in time during dose delivery. Given the radiotherapy plan and machine specific limitations, a VMAT treatment plan can be split into arc sectors between Digital Imaging and Communications in Medicine control points (CPs) of constant and known MU rate. By calculating dose distributions in each of these arc sectors independently and multiplying them with the MU rate, the dose rate in every single voxel at every time point during the fraction can be calculated. Independently calculated and then summed dose distributions per arc sector were compared to the whole arc dose calculation for validation. Dose measurements and video analysis were performed to validate the calculated datasets. A clinical head and neck, cranial and liver case were analyzed using the tool developed. Measurement validation of synthetic test cases showed linac agreement to precalculated arc sector times within  ±0.4 s and doses  ±0.1 MU (one standard deviation). Two methods for the visualization of dose rate datasets were developed: the first method plots a two-dimensional (2D) histogram of the number of voxels receiving a given dose rate over the course of the arc treatment delivery. In similarity to treatment planning system display of dose, the second method displays the dose rate as color wash on top of the corresponding computed tomography image, allowing the user to scroll through the variation over time. Examining clinical cases showed dose rates spread over a continuous spectrum, with mean dose rates hardly exceeding 100 cGy min-1 for conventional

  16. Uncertainty Quantification in Internal Dose Calculations for Seven Selected Radiopharmaceuticals.

    PubMed

    Spielmann, Vladimir; Li, Wei Bo; Zankl, Maria; Oeh, Uwe; Hoeschen, Christoph

    2016-01-01

    Dose coefficients of radiopharmaceuticals have been published by the International Commission on Radiological Protection (ICRP) and the MIRD Committee but without information concerning uncertainties. The uncertainty information of dose coefficients is important, for example, to compare alternative diagnostic methods and choose the method that causes the lowest patient exposure with appropriate and comparable diagnostic quality. For the study presented here, an uncertainty analysis method was developed and used to calculate the uncertainty of the internal doses of 7 common radiopharmaceuticals. On the basis of the generalized schema of dose calculation recommended by the ICRP and MIRD Committee, an analysis based on propagation of uncertainty was developed and applied for 7 radiopharmaceuticals. The method takes into account the uncertainties contributed from pharmacokinetic models and the so-called S values derived from several voxel computational phantoms previously developed at Helmholtz Zentrum München. Random and Latin hypercube sampling techniques were used to sample parameters of pharmacokinetic models and S values, and the uncertainties of absorbed doses and effective doses were calculated. The uncertainty factors (square root of the ratio between 97.5th and 2.5th percentiles) for organ-absorbed doses are in the range of 1.1-3.3. Uncertainty values of effective doses are lower in comparison to absorbed doses, the maximum value being approximately 1.4. The ICRP reference values showed a deviation comparable to the effective dose calculated in this study. A general statistical method was developed for calculating the uncertainty of absorbed doses and effective doses for 7 radiopharmaceuticals. The dose uncertainties can be used to further identify the most important parameters in the dose calculation and provide reliable dose coefficients for risk analysis of the patients in nuclear medicine. © 2016 by the Society of Nuclear Medicine and Molecular Imaging

  17. Mesorad dose assessment model. Volume 1. Technical basis

    SciTech Connect

    Scherpelz, R.I.; Bander, T.J.; Athey, G.F.; Ramsdell, J.V.

    1986-03-01

    MESORAD is a dose assessment model for emergency response applications. Using release data for as many as 50 radionuclides, the model calculates: (1) external doses resulting from exposure to radiation emitted by radionuclides contained in elevated or deposited material; (2) internal dose commitment resulting from inhalation; and (3) total whole-body doses. External doses from airborne material are calculated using semi-infinite and finite cloud approximations. At each stage in model execution, the appropriate approximation is selected after considering the cloud dimensions. Atmospheric processes are represented in MESORAD by a combination of Lagrangian puff and Gaussian plume dispersion models, a source depletion (deposition velocity) dry deposition model, and a wet deposition model using washout coefficients based on precipitation rates.

  18. Radiological assessment. A textbook on environmental dose analysis

    SciTech Connect

    Till, J.E.; Meyer, H.R.

    1983-09-01

    Radiological assessment is the quantitative process of estimating the consequences to humans resulting from the release of radionuclides to the biosphere. It is a multidisciplinary subject requiring the expertise of a number of individuals in order to predict source terms, describe environmental transport, calculate internal and external dose, and extrapolate dose to health effects. Up to this time there has been available no comprehensive book describing, on a uniform and comprehensive level, the techniques and models used in radiological assessment. Radiological Assessment is based on material presented at the 1980 Health Physics Society Summer School held in Seattle, Washington. The material has been expanded and edited to make it comprehensive in scope and useful as a text. Topics covered include (1) source terms for nuclear facilities and Medical and Industrial sites; (2) transport of radionuclides in the atmosphere; (3) transport of radionuclides in surface waters; (4) transport of radionuclides in groundwater; (5) terrestrial and aquatic food chain pathways; (6) reference man; a system for internal dose calculations; (7) internal dosimetry; (8) external dosimetry; (9) models for special-case radionuclides; (10) calculation of health effects in irradiated populations; (11) evaluation of uncertainties in environmental radiological assessment models; (12) regulatory standards for environmental releases of radionuclides; (13) development of computer codes for radiological assessment; and (14) assessment of accidental releases of radionuclides.

  19. Risk assessment in international operations

    SciTech Connect

    Stricklin, Daniela L.

    2008-11-15

    During international peace-keeping missions, a diverse number of non-battle hazards may be encountered, which range from heavily polluted areas, endemic disease, toxic industrial materials, local violence, traffic, and even psychological factors. Hence, elevated risk levels from a variety of sources are encountered during deployments. With the emphasis within the Swedish military moving from national defense towards prioritization of international missions in atypical environments, the risk of health consequences, including long term health effects, has received greater consideration. The Swedish military is interested in designing an optimal approach for assessment of health threats during deployments. The Medical Intelligence group at FOI CBRN Security and Defence in Umea has, on request from and in collaboration with the Swedish Armed Forces, reviewed a variety of international health threat and risk assessment models for military operations. Application of risk assessment methods used in different phases of military operations will be reviewed. An overview of different international approaches used in operational risk management (ORM) will be presented as well as a discussion of the specific needs and constraints for health risk assessment in military operations. This work highlights the specific challenges of risk assessment that are unique to the deployment setting such as the assessment of exposures to a variety of diverse hazards concurrently.

  20. Assessments for High Dose Radionuclide Therapy Treatment Planning

    SciTech Connect

    Fisher, Darrell R.

    2003-10-01

    Advances in the biotechnology of cell-specific targeting of cancer, and the increased number of clinical trials involving treatment of cancer patients with radiolabeled antibodies, peptides, and similar delivery vehicles have led to an increase in the number of high-dose radionuclide therapy procedures. Optimized radionuclide therapy for cancer treatment is based on the concept of absorbed dose to the dose-limiting normal organ or tissue. The limiting normal tissue is often the red marrow, but it may sometimes be lungs, liver, intestinal tract, or kidneys. Appropriate treatment planning requires assessment of radiation dose to several internal organs and tissues, and usually involves biodistribution studies in the patient using a tracer amount of radionuclide bound to the targeting agent and imaged at sequential time points using a planar gamma camera. Time-activity curves are developed from the imaging data for the major organs tissues of concern, for the whole body, and sometimes for selected tumors. Patient-specific factors often require that dose estimates be customized for each patient. The Food and Drug Administration regulates the experimental use of investigational new drugs and requires reasonable calculation of radiation absorbed dose to the whole body and to critical organs using methods prescribed by the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. Review of high-dose studies in the U.S. and elsewhere shows that 1) some studies are conducted with minimal dosimetry, 2) the marrow dose is difficult to establish and is subject to large uncertainties, and 3) despite the general availability of MIRD software, internal dosimetry methods are often inconsistent from one clinical center to another.

  1. DRY TRANSFER FACILITY WORKER DOSE ASSESSMENT

    SciTech Connect

    J.S. Tang

    2004-09-23

    The purpose of this calculation is to estimate radiation doses received by personnel working in the Dry Transfer Facility No.1 (DTF-1) performing operations to receive transportation casks, transfer wastes, prepare waste packages, and ship out loaded waste packages and empty casks. Doses received by workers due to maintenance operations are also included in this revision. The specific scope of work contained in this calculation covers both collective doses and individual worker group doses on an annual basis, and includes the contributions due to external and internal radiation from normal operation, excluding the remediation area of the building. The results of this calculation will be used to support the design of the DTF-1 and to provide occupational dose estimates for the License Application. The calculations contained in this document were developed by Environmental and Nuclear Engineering of the Design and Engineering Organization and are intended solely for the use of the Design and Engineering Organization in its work regarding facility operation. Yucca Mountain Project personnel from the Environmental and Nuclear Engineering should be consulted before use of the calculations for purposes other than those stated herein or use by individuals other than authorized personnel in the Environmental and Nuclear Engineering.

  2. Reassessing benzene risks using internal doses and Monte-Carlo uncertainty analysis.

    PubMed Central

    Cox, L A

    1996-01-01

    Human cancer risks from benzene have been estimated from epidemiological data, with supporting evidence from animal bioassay data. This article reexamines the animal-based risk assessments using physiologically based pharmacokinetic (PBPK) models of benzene metabolism in animals and humans. Internal doses (total benzene metabolites) from oral gavage experiments in mice are well predicted by the PBPK model. Both the data and the PBPK model outputs are also well described by a simple nonlinear (Michaelis-Menten) regression model, as previously used by Bailer and Hoel [Metabolite-based internal doses used in risk assessment of benzene. Environ Health Perspect 82:177-184 (1989)]. Refitting the multistage model family to internal doses changes the maximum-likelihood estimate (MLE) dose-response curve for mice from linear-quadratic to purely cubic, so that low-dose risk estimates are smaller than in previous risk assessments. In contrast to Bailer and Hoel's findings using interspecies dose conversion, the use of internal dose estimates for humans from a PBPK model reduces estimated human risks at low doses. Sensitivity analyses suggest that the finding of a nonlinear MLE dose-response curve at low doses is robust to changes in internal dose definitions and more consistent with epidemiological data than earlier risk models. A Monte-Carlo uncertainty analysis based on maximum-entropy probabilities and Bayesian conditioning is used to develop an entire probability distribution for the true but unknown dose-response function. This allows the probability of a positive low-dose slope to be quantified: It is about 10%. An upper 95% confidence limit on the low-dose slope of excess risk is also obtained directly from the posterior distribution and is similar to previous q1* values. This approach suggests that the excess risk due to benzene exposure may be nonexistent (or even negative) at sufficiently low doses. Two types of biological information about benzene effects

  3. Ivermectin dose assessment without weighing scales.

    PubMed Central

    Alexander, N. D.; Cousens, S. N.; Yahaya, H.; Abiose, A.; Jones, B. R.

    1993-01-01

    Described are two alternatives to the weighing of patients for assessing the dose of ivermectin for use in mass chemotherapy campaigns against onchocerciasis. The first method uses height to separate patients into four dosing categories (1/2, 1, 11/2 and 2 tablets), while the second involves estimating one of these dosing categories according to an individual's physical appearance, without making any measurements. Data for the height-based method were obtained from 6373 people who were taking part in a placebo-controlled trial of ivermectin in northern Nigeria. Use of an arbitrary trade-off of approximately 100 people "overdosed" for every person "underdosed" would lead to 0.5% of the population being underdosed by 1/2 tablet, 46.5% being dosed correctly, 51.7% being overdosed by 1/2 tablet, and 1.2% being overdosed by 1 tablet. The physical appearance approach involved three observers and 779 subjects. A total of 82% of the observers' estimates were "correct", with all the incorrect dosing deviating by only 1/2 tablet from the dose that the subjects should have received. PMID:8324855

  4. Dose estimates for the solid waste performance assessment

    SciTech Connect

    Rittman, P.D.

    1994-08-30

    The Solid Waste Performance Assessment calculations by PNL in 1990 were redone to incorporate changes in methods and parameters since then. The ten scenarios found in their report were reduced to three, the Post-Drilling Resident, the Post-Excavation Resident, and an All Pathways Irrigator. In addition, estimates of population dose to people along the Columbia River are also included. The attached report describes the methods and parameters used in the calculations, and derives dose factors for each scenario. In addition, waste concentrations, ground water concentrations, and river water concentrations needed to reach the performance objectives of 100 mrem/yr and 500 person-rem/yr are computed. Internal dose factors from DOE-0071 were applied when computing internal dose. External dose rate factors came from the GENII Version 1.485 software package. Dose calculations were carried out on a spreadsheet. The calculations are described in detail in the report for 63 nuclides, including 5 not presently in the GENII libraries. The spreadsheet calculations were checked by comparison with GENII, as described in Appendix D.

  5. Computed Tomography: Image and Dose Assessment

    SciTech Connect

    Valencia-Ortega, F.; Ruiz-Trejo, C.; Rodriguez-Villafuerte, M.; Buenfil, A. E.; Mora-Hernandez, L. A.

    2006-09-08

    In this work an experimental evaluation of image quality and dose imparted during a computed tomography study in a Public Hospital in Mexico City is presented; The measurements required the design and construction of two phantoms at the Institute of Physics, UNAM, according to the recommendations of American Association of Physicists in Medicine (AAPM). Image assessment was performed in terms the spatial resolution and image contrast. Dose measurements were carried out using LiF: Mg,Ti (TLD-100) dosemeters and pencil-shaped ionisation chamber; The results for a computed tomography head study in single and multiple detector modes are presented.

  6. Internal dose following a large-scale nuclear war

    SciTech Connect

    Peterson, K.R.; Shapiro, C.S.; Harvey, T.F.

    1988-03-01

    In this study, we use the PATHWAY model, in conjunction with a reasonable hypothetical nuclear attack on the US to arrive at calculations of internal and external dose estimates that are based on valid model results. Our own estimates are presented with calculational aids (at every step) that enable readers to use their own nuclear war scenarios, fallout patterns, assumptions about the climatic changes brought on by large fires following a nuclear attack, the viability of the transportation system for food delivery, the quality and quantity of water and foods available locally, the required caloric intakes of the survivors, and several other factors. We conclude that the average American family that survived a large-scale nuclear war, using their own home or workplace as a refuge, would receive a total internal dose from ingestion that is from one to 10 percent of the total external dose. Those who stayed where shelter protection factors and foraged food consumption were large could receive internal doses from 11 percent to more than 100% of the total external dose. 28 refs., 9 figs.

  7. Gamma dose from activation of internal shields in IRIS reactor.

    PubMed

    Agosteo, Stefano; Cammi, Antonio; Garlati, Luisella; Lombardi, Carlo; Padovani, Enrico

    2005-01-01

    The International Reactor Innovative and Secure is a modular pressurised water reactor with an integral design. This means that all the primary system components, such as the steam generators, pumps, pressuriser and control rod drive mechanisms, are located inside the reactor vessel, which requires a large diameter. For the sake of better reliability and safety, it is desirable to achieve the reduction of vessel embrittlement as well as the lowering of the dose beyond the vessel. The former can be easily accomplished by the presence of a wide downcomer, filled with water, which surrounds the core region, while the latter needs the presence of additional internal shields. An optimal shielding configuration is under investigation, for reducing the ex-vessel dose due to activated internals and for limiting the amount of the biological shielding. MCNP 4C calculations were performed to evaluate the neutron and the gamma dose during operation and the 60Co activation of various shields configurations. The gamma dose beyond the vessel from activation of its structural components was estimated in a shutdown condition, with the Monte Carlo code FLUKA 2002 and the MicroShield software. The results of the two codes are in agreement and show that the dose is sufficiently low, even without an additional shield.

  8. Dose Calculation Evolution for Internal Organ Irradiation in Humans

    SciTech Connect

    Jimenez V, Reina A.

    2007-10-26

    The International Commission of Radiation Units (ICRU) has established through the years, a discrimination system regarding the security levels on the prescription and administration of doses in radiation treatments (Radiotherapy, Brach therapy, Nuclear Medicine). The first level is concerned with the prescription and posterior assurance of dose administration to a point of interest (POI), commonly located at the geometrical center of the region to be treated. In this, the effects of radiation around that POI, is not a priority. The second level refers to the dose specifications in a particular plane inside the patient, mostly the middle plane of the lesion. The dose is calculated to all the structures in that plane regardless if they are tumor or healthy tissue. In this case, the dose is not represented by a point value, but by level curves called 'isodoses' as in a topographic map, so you can assure the level of doses to this particular plane, but it also leave with no information about how this values go thru adjacent planes. This is why the third level is referred to the volumetrical description of doses so these isodoses construct now a volume (named 'cloud') that give us better assurance about tissue irradiation around the volume of the lesion and its margin (sub clinical spread or microscopic illness). This work shows how this evolution has resulted, not only in healthy tissue protection improvement but in a rise of tumor control, quality of life, better treatment tolerance and minimum permanent secuelae.

  9. Multi-component assessment of chronic obstructive pulmonary disease: an evaluation of the ADO and DOSE indices and the global obstructive lung disease categories in international primary care data sets

    PubMed Central

    Jones, Rupert C; Price, David; Chavannes, Niels H; Lee, Amanda J; Hyland, Michael E; Ställberg, Björn; Lisspers, Karin; Sundh, Josefin; van der Molen, Thys; Tsiligianni, Ioanna

    2016-01-01

    Suitable tools for assessing the severity of chronic obstructive pulmonary disease (COPD) include multi-component indices and the global initiative for chronic obstructive lung disease (GOLD) categories. The aim of this study was to evaluate the dyspnoea, obstruction, smoking, exacerbation (DOSE) and the age, dyspnoea, obstruction (ADO) indices and GOLD categories as measures of current health status and future outcomes in COPD patients. This was an observational cohort study comprising 5,114 primary care COPD patients across three databases from UK, Sweden and Holland. The associations of DOSE and ADO indices with (i) health status using the Clinical COPD Questionnaire (CCQ) and St George’s Respiratory Questionnaire (SGRQ) and COPD Assessment test (CAT) and with (ii) current and future exacerbations, admissions and mortality were assessed in GOLD categories and DOSE and ADO indices. DOSE and ADO indices were significant predictors of future exacerbations: incident rate ratio was 1.52 (95% confidence intervals 1.46–1.57) for DOSE, 1.16 (1.12–1.20) for ADO index and 1.50 (1.33–1.68) and 1.23 (1.10–1.39), respectively, for hospitalisations. Negative binomial regression showed that the DOSE index was a better predictor of future admissions than were its component items. The hazard ratios for mortality were generally higher for ADO index groups than for DOSE index groups. The GOLD categories produced widely differing assessments for future exacerbation risk or for hospitalisation depending on the methods used to calculate them. None of the assessment systems were excellent at predicting future risk in COPD; the DOSE index appears better than the ADO index for predicting many outcomes, but not mortality. The GOLD categories predict future risk inconsistently. The DOSE index and the GOLD categories using exacerbation frequency may be used to identify those at high risk for exacerbations and admissions. PMID:27053297

  10. Multi-component assessment of chronic obstructive pulmonary disease: an evaluation of the ADO and DOSE indices and the global obstructive lung disease categories in international primary care data sets.

    PubMed

    Jones, Rupert C; Price, David; Chavannes, Niels H; Lee, Amanda J; Hyland, Michael E; Ställberg, Björn; Lisspers, Karin; Sundh, Josefin; van der Molen, Thys; Tsiligianni, Ioanna

    2016-04-07

    Suitable tools for assessing the severity of chronic obstructive pulmonary disease (COPD) include multi-component indices and the global initiative for chronic obstructive lung disease (GOLD) categories. The aim of this study was to evaluate the dyspnoea, obstruction, smoking, exacerbation (DOSE) and the age, dyspnoea, obstruction (ADO) indices and GOLD categories as measures of current health status and future outcomes in COPD patients. This was an observational cohort study comprising 5,114 primary care COPD patients across three databases from UK, Sweden and Holland. The associations of DOSE and ADO indices with (i) health status using the Clinical COPD Questionnaire (CCQ) and St George's Respiratory Questionnaire (SGRQ) and COPD Assessment test (CAT) and with (ii) current and future exacerbations, admissions and mortality were assessed in GOLD categories and DOSE and ADO indices. DOSE and ADO indices were significant predictors of future exacerbations: incident rate ratio was 1.52 (95% confidence intervals 1.46-1.57) for DOSE, 1.16 (1.12-1.20) for ADO index and 1.50 (1.33-1.68) and 1.23 (1.10-1.39), respectively, for hospitalisations. Negative binomial regression showed that the DOSE index was a better predictor of future admissions than were its component items. The hazard ratios for mortality were generally higher for ADO index groups than for DOSE index groups. The GOLD categories produced widely differing assessments for future exacerbation risk or for hospitalisation depending on the methods used to calculate them. None of the assessment systems were excellent at predicting future risk in COPD; the DOSE index appears better than the ADO index for predicting many outcomes, but not mortality. The GOLD categories predict future risk inconsistently. The DOSE index and the GOLD categories using exacerbation frequency may be used to identify those at high risk for exacerbations and admissions.

  11. Internal dose conversion factors for calculation of dose to the public

    SciTech Connect

    Not Available

    1988-07-01

    This publication contains 50-year committed dose equivalent factors, in tabular form. The document is intended to be used as the primary reference by the US Department of Energy (DOE) and its contractors for calculating radiation dose equivalents for members of the public, resulting from ingestion or inhalation of radioactive materials. Its application is intended specifically for such materials released to the environment during routine DOE operations, except in those instances where compliance with 40 CFR 61 (National Emission Standards for Hazardous Air Pollutants) requires otherwise. However, the calculated values may be equally applicable to unusual releases or to occupational exposures. The use of these committed dose equivalent tables should ensure that doses to members of the public from internal exposures are calculated in a consistent manner at all DOE facilities.

  12. Assessment of dose during an SGTR

    SciTech Connect

    Adams, J.P.

    1993-01-01

    The Nuclear Regulatory Commission requires utilities to determine the response of a pressurized water reactor to a steam generator tube rupture (SGTR) as part of the safety analysis for the plant. The SGTR analysis includes assumptions regarding the iodine concentration in the reactor coolant system (RCS) due to iodine spikes, primary flashing and bypass fractions, and iodine partitioning in the secondary coolant system (SCS). Experimental and analytical investigations have recently been completed wherein these assumptions were tested to determine whether and to what degree they were conservative (that is, whether they result in a calculated iodine source term/dose that is at least as large or larger than that expected during an actual event). The current study has the objective to assess the overall effects of the results of these investigations on the calculated iodine dose to the environment during an SGTR. To assist in this study, a computer program, DOSE, was written. This program uses a simple, non-mechanistic model to calculate the iodine source term to the environment during an SGTR as a function of water mass inventories and flow rates and iodine concentrations in the RCS and SCS. The principal conclusion of this study is that the iodine concentration in the RCS is the dominant parameter, due to the dominance of primary flashing on the iodine source term.

  13. Natural radionuclides in clay deposits: concentration and dose assessment.

    PubMed

    Khater, Ashraf E M; Al-Mobark, Layla H; Aly, Amany A; Al-Omran, A M

    2013-09-01

    Clays are among the most important industrially used minerals. Three potential clay mineral mining sites in Saudi Arabia were chosen, and 21 clay deposit samples were collected. The activity concentrations (average±standard deviation) of the naturally occurring radioactive materials (NORMs), (238)U, (226)Ra, (232)Th, (228)Ra and (40)K, were 49±20, 47±23, 34±11, 40±20 and 751 Bq kg(-1), respectively. The radiation dose assessments (e.g., absorbed dose rate, nGy h(-1); effective dose equivalent, µSv y(-1); and effective dose rate due to dust inhalation, µSv y(-1)) and hazardous indices (e.g., radium equivalent [Ra-eq] value, external hazardous index [Hex], internal hazardous index [Hin] and representative gamma level [Iγ]) were calculated. The wide variations in the activity concentrations of the NORMs according to sampling region could be due to the origin of the geological formation and the geochemical behaviour of the NORMs. Based on calculated hazardous (external and internal) indices, there were no expected radiological hazardous impacts of using clay deposits as building materials.

  14. Patient doses in CT examinations in 18 countries: initial results from International Atomic Energy Agency projects.

    PubMed

    Muhogora, W E; Ahmed, N A; Beganovic, A; Benider, A; Ciraj-Bjelac, O; Gershan, V; Gershkevitsh, E; Grupetta, E; Kharita, M H; Manatrakul, N; Milakovic, M; Ohno, K; Ben Omrane, L; Ptacek, J; Schandorf, C; Shabaan, M S; Stoyanov, D; Toutaoui, N; Wambani, J S; Rehani, M M

    2009-09-01

    The purpose of this prospective study at 73 facilities in 18 countries in Africa, Asia and Eastern Europe was to investigate if the CT doses to adult patients in developing countries are higher than international standards. The dose assessment was performed in terms of weighted computed tomography dose index (CTDIw) and dose length product (DLP) for chest, chest (high resolution), lumbar spine, abdomen and pelvis CT examinations using standard methods. Except in one case, the mean CTDIw values were below diagnostic reference level (DRL) while for DLP, 17 % of situations were above DRLs. The resulting CT images were of adequate quality for diagnosis. The CTDIw and DLP data presented herein are largely similar to those from two recent national surveys. The study has shown a stronger need to create awareness and training of radiology personnel as well as monitoring of radiation doses in many developing countries so as to conform to the ALARA principle.

  15. Assessment of out-of-field absorbed dose and equivalent dose in proton fields

    SciTech Connect

    Clasie, Ben; Wroe, Andrew; Kooy, Hanne; Depauw, Nicolas; Flanz, Jay; Paganetti, Harald; Rosenfeld, Anatoly

    2010-01-15

    . Conclusions: The dose deposited immediately downstream of the primary field, in these cases, is dominated by internally produced neutrons; therefore, scattered and scanned fields may have similar risk of second cancer in this region. The authors confirm that there is a reduction in the out-of-field dose in active scanning but the effect decreases with depth. GEANT4 is suitable for simulating the dose deposited outside the primary field. The agreement with measurements is comparable to or better than the agreement reported for other implementations of Monte Carlo models. Depending on the position, the absorbed dose outside the primary field is dominated by contributions from primary protons that may or may not have scattered in the brass collimating devices. This is noteworthy as the quality factor of the low LET protons is well known and the relative dose risk in this region can thus be assessed accurately.

  16. Internal scatter, the unavoidable major component of the peripheral dose in photon-beam radiotherapy.

    PubMed

    Chofor, Ndimofor; Harder, Dietrich; Willborn, Kay C; Poppe, Björn

    2012-03-21

    In clinical photon beams, the dose outside the geometrical field limits is produced by photons originating from (i) head leakage, (ii) scattering at the beam collimators and the flattening filter (head scatter) and (iii) scattering from the directly irradiated region of the patient or phantom (internal scatter). While the first two components can be modified, e.g. by reinforcement of shielding components or by re-modeling the filter system, internal scatter remains an unavoidable contributor to the peripheral dose. Its relative magnitude compared to the other components, its numerical variation with beam energy, field size and off-axis distance as well as its spectral distribution are evaluated in this study. We applied a detailed Monte Carlo (MC) model of our 6/15 MV Siemens Primus linear accelerator beam head, provided with ideal head leakage shielding conditions (multi-leaf collimator without gaps) to assess the head scatter contribution. Experimental values obtained under real shielding conditions were used to evaluate the head leakage contribution. It was found that the MC-computed internal scatter doses agree with the results of our previous measurements, that internal scatter is the major contributor to the peripheral dose in the near periphery while head leakage prevails in the far periphery, and that the lateral decline of the internal scatter dose can be represented by the sum of two exponentials, with an asymptotic tenth value of 18 to 19 cm. Internal scatter peripheral doses from various elementary beams are additive, so that their sum increases approximately in proportion with field size. The ratio between normalized internal scatter doses at 6 and 15 MV is approximately 2:1. The energy fluence spectra of the internal scatter component at all points of interest outside the field have peaks near 500 keV. The fact that the energy-shifted internal scatter constitutes the major contributor to the dose in the near periphery has a general bearing for

  17. Internal scatter, the unavoidable major component of the peripheral dose in photon-beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Chofor, Ndimofor; Harder, Dietrich; Willborn, Kay C.; Poppe, Björn

    2012-03-01

    In clinical photon beams, the dose outside the geometrical field limits is produced by photons originating from (i) head leakage, (ii) scattering at the beam collimators and the flattening filter (head scatter) and (iii) scattering from the directly irradiated region of the patient or phantom (internal scatter). While the first two components can be modified, e.g. by reinforcement of shielding components or by re-modeling the filter system, internal scatter remains an unavoidable contributor to the peripheral dose. Its relative magnitude compared to the other components, its numerical variation with beam energy, field size and off-axis distance as well as its spectral distribution are evaluated in this study. We applied a detailed Monte Carlo (MC) model of our 6/15 MV Siemens Primus linear accelerator beam head, provided with ideal head leakage shielding conditions (multi-leaf collimator without gaps) to assess the head scatter contribution. Experimental values obtained under real shielding conditions were used to evaluate the head leakage contribution. It was found that the MC-computed internal scatter doses agree with the results of our previous measurements, that internal scatter is the major contributor to the peripheral dose in the near periphery while head leakage prevails in the far periphery, and that the lateral decline of the internal scatter dose can be represented by the sum of two exponentials, with an asymptotic tenth value of 18 to 19 cm. Internal scatter peripheral doses from various elementary beams are additive, so that their sum increases approximately in proportion with field size. The ratio between normalized internal scatter doses at 6 and 15 MV is approximately 2:1. The energy fluence spectra of the internal scatter component at all points of interest outside the field have peaks near 500 keV. The fact that the energy-shifted internal scatter constitutes the major contributor to the dose in the near periphery has a general bearing for

  18. Shuttle radiation dose measurements in the International Space Station orbits.

    PubMed

    Badhwar, Gautam D

    2002-01-01

    The International Space Station (ISS) is now a reality with the start of a permanent human presence on board. Radiation presents a serious risk to the health and safety of the astronauts, and there is a clear requirement for estimating their exposures prior to and after flights. Predictions of the dose rate at times other than solar minimum or solar maximum have not been possible, because there has been no method to calculate the trapped-particle spectrum at intermediate times. Over the last few years, a tissue-equivalent proportional counter (TEPC) has been flown at a fixed mid-deck location on board the Space Shuttle in 51.65 degrees inclination flights. These flights have provided data that cover the expected changes in the dose rates due to changes in altitude and changes in solar activity from the solar minimum to the solar maximum of the current 23rd solar cycle. Based on these data, a simple function of the solar deceleration potential has been derived that can be used to predict the galactic cosmic radiation (GCR) dose rates to within +/-10%. For altitudes to be covered by the ISS, the dose rate due to the trapped particles is found to be a power-law function, rho(-2/3), of the atmospheric density, rho. This relationship can be used to predict trapped dose rates inside these spacecraft to +/-10% throughout the solar cycle. Thus, given the shielding distribution for a location inside the Space Shuttle or inside an ISS module, this approach can be used to predict the combined GCR + trapped dose rate to better than +/-15% for quiet solar conditions.

  19. Preliminary dose assessment of the Chernobyl accident

    SciTech Connect

    Hull, A.P.

    1987-01-01

    From the major accident at Unit 4 of the Chernobyl nuclear power station, a plume of airborne radioactive fission products was initially carried northwesterly toward Poland, thence toward Scandinavia and into Central Europe. Reports of the levels of radioactivity in a variety of media and of external radiation levels were collected in the Department of Energy's Emergency Operations Center and compiled into a data bank. Portions of these and other data which were obtained directly from published and official reports were utilized to make a preliminary assessment of the extent and magnitude of the external dose to individuals downwind from Chernobyl. Radioactive /sup 131/I was the predominant fission product. The time of arrival of the plume and the maximum concentrations of /sup 131/I in air, vegetation and milk and the maximum reported depositions and external radiation levels have been tabulated country by country. A large amount of the total activity in the release was apparently carried to a significant elevation. The data suggest that in areas where rainfall occurred, deposition levels were from ten to one-hundred times those observed in nearby ''dry'' locations. Sufficient spectral data were obtained to establish average release fractions and to establish a reference spectra of the other nuclides in the release. Preliminary calculations indicated that the collective dose equivalent to the population in Scandinavia and Central Europe during the first year after the Chernobyl accident would be about 8 x 10/sup 6/ person-rem. From the Soviet report, it appears that a first year population dose of about 2 x 10/sup 7/ person-rem (2 x 10/sup 5/ Sv) will be received by the population who were downwind of Chernobyl within the U.S.S.R. during the accident and its subsequent releases over the following week. 32 refs., 14 figs., 20 tabs.

  20. Interactive Rapid Dose Assessment Model (IRDAM): scenarios for comparing dose-assessment models. Vol. 3

    SciTech Connect

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    The Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program designed to provide rapid assessments of the radiological impact of accidents at nuclear power plants. The main body of this document consists of 28 examples of IRDAM input and output, representing various types of accidents and releases. These examples are intended to provide a basis for comparison with other models or for testing IRDAM itself. Figures are included which show dose rates calculated by IRDAM for each scenario. Figures are also included which show calculations made using the computer codes WRAITH (Scherpelz, Borst and Hoenes, 1980) and RADPUR (Dabbert, et. al., 1982). Two other companion volumes to this one provide additional information on IRDAM. The User's Guide (NUREG/CR-3012, Volume 1) describes the setup and operation of equipment necessary to run IRDAM. Reactor Accident Assessment Methods (NUREG/CR-3012, Volume 2) describes the technical bases for IRDAM including methods, models and assumptions used in calculations.

  1. International assessment of PCA codes

    SciTech Connect

    Neymotin, L.; Lui, C.; Glynn, J.; Archarya, S.

    1993-11-01

    Over the past three years (1991-1993), an extensive international exercise for intercomparison of a group of six Probabilistic Consequence Assessment (PCA) codes was undertaken. The exercise was jointly sponsored by the Commission of European Communities (CEC) and OECD Nuclear Energy Agency. This exercise was a logical continuation of a similar effort undertaken by OECD/NEA/CSNI in 1979-1981. The PCA codes are currently used by different countries for predicting radiological health and economic consequences of severe accidents at nuclear power plants (and certain types of non-reactor nuclear facilities) resulting in releases of radioactive materials into the atmosphere. The codes participating in the exercise were: ARANO (Finland), CONDOR (UK), COSYMA (CEC), LENA (Sweden), MACCS (USA), and OSCAAR (Japan). In parallel with this inter-code comparison effort, two separate groups performed a similar set of calculations using two of the participating codes, MACCS and COSYMA. Results of the intercode and inter-MACCS comparisons are presented in this paper. The MACCS group included four participants: GREECE: Institute of Nuclear Technology and Radiation Protection, NCSR Demokritos; ITALY: ENEL, ENEA/DISP, and ENEA/NUC-RIN; SPAIN: Universidad Politecnica de Madrid (UPM) and Consejo de Seguridad Nuclear; USA: Brookhaven National Laboratory, US NRC and DOE.

  2. 10 CFR 835.203 - Combining internal and external equivalent doses.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... External Exposure § 835.203 Combining internal and external equivalent doses. (a) The total effective dose during a year shall be determined by summing the effective dose from external exposures and the committed... 10 Energy 4 2010-01-01 2010-01-01 false Combining internal and external equivalent doses....

  3. 241Am Ingrowth and Its Effect on Internal Dose

    DOE PAGES

    Konzen, Kevin

    2016-07-01

    Generally, plutonium has been manufactured to support commercial and military applications involving heat sources, weapons and reactor fuel. This work focuses on three typical plutonium mixtures, while observing the potential of 241Am ingrowth and its effect on internal dose. The term “ingrowth” is used to describe 241Am production due solely from the decay of 241Pu as part of a plutonium mixture, where it is initially absent or present in a smaller quantity. Dose calculation models do not account for 241Am ingrowth unless the 241Pu quantity is specified. This work suggested that 241Am ingrowth be considered in bioassay analysis when theremore » is a potential of a 10% increase to the individual’s committed effective dose. It was determined that plutonium fuel mixtures, initially absent of 241Am, would likely exceed 10% for typical reactor grade fuel aged less than 30 years; however, heat source grade and aged weapons grade fuel would normally fall below this threshold. In conclusion, although this work addresses typical plutonium mixtures following separation, it may be extended to irradiated commercial uranium fuel and is expected to be a concern in the recycling of spent fuel.« less

  4. Perspectives on Numeracy: Reflections from International Assessments

    ERIC Educational Resources Information Center

    Tout, Dave; Gal, Iddo

    2015-01-01

    This paper examines perspectives regarding the mathematical skills expected of adults and school graduates, comparing ideas developed as part of two major multinational comparative assessments of skills: the Programme for International Student Assessment and the Programme for International Assessment of Adult Competencies (also known as the OECD…

  5. Perspectives on Numeracy: Reflections from International Assessments

    ERIC Educational Resources Information Center

    Tout, Dave; Gal, Iddo

    2015-01-01

    This paper examines perspectives regarding the mathematical skills expected of adults and school graduates, comparing ideas developed as part of two major multinational comparative assessments of skills: the Programme for International Student Assessment and the Programme for International Assessment of Adult Competencies (also known as the OECD…

  6. Estimates of internal-dose equivalent from inhalation and ingestion of selected radionuclides

    SciTech Connect

    Dunning, D.E.

    1982-01-01

    This report presents internal radiation dose conversion factors for radionuclides of interest in environmental assessments of nuclear fuel cycles. This volume provides an updated summary of estimates of committed dose equivalent for radionuclides considered in three previous Oak Ridge National Laboratory (ORNL) reports. Intakes by inhalation and ingestion are considered. The International Commission on Radiological Protection (ICRP) Task Group Lung Model has been used to simulate the deposition and retention of particulate matter in the respiratory tract. Results corresponding to activity median aerodynamic diameters (AMAD) of 0.3, 1.0, and 5.0 ..mu..m are given. The gastorintestinal (GI) tract has been represented by a four-segment catenary model with exponential transfer of radioactivity from one segment to the next. Retention of radionuclides in systemic organs is characterized by linear combinations of decaying exponential functions, recommended in ICRP Publication 30. The first-year annual dose rate, maximum annual dose rate, and fifty-year dose commitment per microcurie intake of each radionuclide is given for selected target organs and the effective dose equivalent. These estimates include contributions from specified source organs plus the systemic activity residing in the rest of the body; cross irradiation due to penetrating radiations has been incorporated into these estimates. 15 references.

  7. Astronaut's organ doses inferred from measurements in a human phantom outside the international space station.

    PubMed

    Reitz, Guenther; Berger, Thomas; Bilski, Pawel; Facius, Rainer; Hajek, Michael; Petrov, Vladislav; Puchalska, Monika; Zhou, Dazhuang; Bossler, Johannes; Akatov, Yury; Shurshakov, Vyacheslav; Olko, Pawel; Ptaszkiewicz, Marta; Bergmann, Robert; Fugger, Manfred; Vana, Norbert; Beaujean, Rudolf; Burmeister, Soenke; Bartlett, David; Hager, Luke; Pálfalvi, József; Szabó, Julianna; O'Sullivan, Denis; Kitamura, Hisashi; Uchihori, Yukio; Yasuda, Nakahiro; Nagamatsu, Aiko; Tawara, Hiroko; Benton, Eric; Gaza, Ramona; McKeever, Stephen; Sawakuchi, Gabriel; Yukihara, Eduardo; Cucinotta, Francis; Semones, Edward; Zapp, Neal; Miller, Jack; Dettmann, Jan

    2009-02-01

    Space radiation hazards are recognized as a key concern for human space flight. For long-term interplanetary missions, they constitute a potentially limiting factor since current protection limits for low-Earth orbit missions may be approached or even exceeded. In such a situation, an accurate risk assessment requires knowledge of equivalent doses in critical radiosensitive organs rather than only skin doses or ambient doses from area monitoring. To achieve this, the MATROSHKA experiment uses a human phantom torso equipped with dedicated detector systems. We measured for the first time the doses from the diverse components of ionizing space radiation at the surface and at different locations inside the phantom positioned outside the International Space Station, thereby simulating an extravehicular activity of an astronaut. The relationships between the skin and organ absorbed doses obtained in such an exposure show a steep gradient between the doses in the uppermost layer of the skin and the deep organs with a ratio close to 20. This decrease due to the body self-shielding and a concomitant increase of the radiation quality factor by 1.7 highlight the complexities of an adequate dosimetry of space radiation. The depth-dose distributions established by MATROSHKA serve as benchmarks for space radiation models and radiation transport calculations that are needed for mission planning.

  8. Dosimetry experiences and lessons learned for radiation dose assessment in Korean nuclear power plants.

    PubMed

    Choi, Jong Rak; Kim, Hee Geun; Kong, Tae Young; Son, Jung Kwon

    2013-07-01

    Since the first Korean nuclear power plant (NPP), Kori 1, commenced operation in 1978, a total of 21 NPPs had been put into operation in Korea by the end of 2011. Radiation doses of NPP workers have been periodically evaluated and controlled within the prescribed dose limit. Radiation dose assessment is carried out monthly by reading personal dosemeters for external radiation exposure, which have traceability in compliance with strict technical guidelines. In the case of the internal radiation exposure, workers who have access to the possible area of polluted air are also evaluated for their internal dose after maintenance task. In this article, the overall situation and experience for the assessment and distribution of radiation doses in Korean NPPs is described.

  9. Smartphone apps for calculating insulin dose: a systematic assessment.

    PubMed

    Huckvale, Kit; Adomaviciute, Samanta; Prieto, José Tomás; Leow, Melvin Khee-Shing; Car, Josip

    2015-05-06

    Medical apps are widely available, increasingly used by patients and clinicians, and are being actively promoted for use in routine care. However, there is little systematic evidence exploring possible risks associated with apps intended for patient use. Because self-medication errors are a recognized source of avoidable harm, apps that affect medication use, such as dose calculators, deserve particular scrutiny. We explored the accuracy and clinical suitability of apps for calculating medication doses, focusing on insulin calculators for patients with diabetes as a representative use for a prevalent long-term condition. We performed a systematic assessment of all English-language rapid/short-acting insulin dose calculators available for iOS and Android. Searches identified 46 calculators that performed simple mathematical operations using planned carbohydrate intake and measured blood glucose. While 59% (n = 27/46) of apps included a clinical disclaimer, only 30% (n = 14/46) documented the calculation formula. 91% (n = 42/46) lacked numeric input validation, 59% (n = 27/46) allowed calculation when one or more values were missing, 48% (n = 22/46) used ambiguous terminology, 9% (n = 4/46) did not use adequate numeric precision and 4% (n = 2/46) did not store parameters faithfully. 67% (n = 31/46) of apps carried a risk of inappropriate output dose recommendation that either violated basic clinical assumptions (48%, n = 22/46) or did not match a stated formula (14%, n = 3/21) or correctly update in response to changing user inputs (37%, n = 17/46). Only one app, for iOS, was issue-free according to our criteria. No significant differences were observed in issue prevalence by payment model or platform. The majority of insulin dose calculator apps provide no protection against, and may actively contribute to, incorrect or inappropriate dose recommendations that put current users at risk of both catastrophic overdose and more

  10. BRADOS - Dose determination in the Russian segment of the International Space Station

    NASA Astrophysics Data System (ADS)

    Hajek, M.; Berger, T.; Fürstner, M.; Fugger, M.; Vana, N.; Akatov, Y.; Shurshakov, V.; Arkhangelsky, V.

    Absorbed dose and dose-average linear energy transfer (LET) were assessed by means of LiF: Mg, Ti thermoluminescence (TL) detectors at different locations onboard the Russian segment (RS) of the International Space Station (ISS) in the timeframe between February and November 2001, i.e. for 248 days. Based on calibrations of the employed detectors in a variety of heavy-ion beams, mainly at the Heavy Ion Medical Accelerator (HIMAC) in Chiba, Japan, the measured absorbed dose values could be corrected for the TL dose registration efficiency in the radiation climate onboard the ISS. Various strategies for efficiency correction are discussed. For the specific case the efficiency correction accounted for a reduction by nearly 20 % in dose, implying that without proper consideration of the TL efficiency behaviour the absorbed dose inside the ISS would be overestimated. The dose-average LET was derived from TLD-700 measurements evaluated according to the well-established high-temperature ratio (HTR) method which analyzes the TL emission in the temperature range between 248 and 310 C. According to the shielding distribution, the efficiency-corrected absorbed dose was found to vary between 155 μ Gy/d for panel N 457 (RS-ISS toilet) and 230 μ Gy/d for panel N 443 (RS-ISS starboard cabin). The determined LET indicated a modification of the spectral composition of the onboard radiation field for the different exposure locations. Arrangement of TLD-600 and TLD-700 in pair allowed also some information about the neutron component to be drawn. Experimentally determined absorbed dose values are compared with model calculations by means of a self-developed code, using as input data detailed shielding distributions and proton fluxes from AP-8 and JPL algorithms.

  11. MESORAD dose assessment of the Chernobyl reactor accident

    SciTech Connect

    Ramsdell, J.V.; Hubbe, J.M.; Athey, G.F.; Davis, W.E.

    1989-12-01

    An accident involving Unit 4 of the Chernobylskaya Atomic Energy Station resulted in the release of a large amount of radioactive material to the atmosphere. This report describes the results of an assessment of the doses near the site (within 80 km) made at the Pacific Northwest Laboratory using the MESORAD Dose Assessment model. 6 refs., 10 figs., 5 tabs.

  12. Mathematical phantoms for evaluation of age-specific internal dose

    SciTech Connect

    Cristy, M.

    1980-01-01

    A series of mathematical phantoms representing children has been developed for use with photon transport codes. These phantoms, patterned after the Fisher-Snyder adult phantom, consist of simple mathematical expressions for the boundaries of the major organs and body sections. The location and shape of the organs are consistent with drawings depicting developmental anatomy, with the organ volumes assigned such that the masses at the various ages conform closely with the data presented in Reference Man. The explicit mathematical expressions for the various ages overcome the potential misrepresentation of organ sizes that occurred in phantoms derived from simple mathematical transformations of the adult phantom. Female breast tissue has been added to the phantoms, including the adult, now allowing assessment of doses to this organ.

  13. Vaginal dose assessment in image-guided brachytherapy for cervical cancer: Can we really rely on dose-point evaluation?

    PubMed

    Limkin, Elaine Johanna; Dumas, Isabelle; Rivin Del Campo, Eleonor; Chargari, Cyrus; Maroun, Pierre; Annède, Pierre; Petit, Claire; Seisen, Thomas; Doyeux, Kaya; Tailleur, Anne; Martinetti, Florent; Lefkopoulos, Dimitri; Haie-Meder, Christine; Mazeron, Renaud

    2016-01-01

    Although dose-volume parameters in image-guided brachytherapy have become a standard, the use of posterior-inferior border of the pubic symphysis (PIBS) points has been recently proposed in the reporting of vaginal doses. The aim was to evaluate their pertinence. Nineteen patients who received image-guided brachytherapy after concurrent radiochemotherapy were included. Per treatment, CT scans were performed at Days 2 and 3, with reporting of the initial dwell positions and times. Doses delivered to the PIBS points were evaluated on each plan, considering that they were representative of one-third of the treatment. The movements of the applicator according to the PIBS point were analysed. Mean prescribed doses at PIBS -2, PIBS, PIBS +2 were, respectively, 2.23 ± 1.4, 6.39 ± 6.6, and 31.85 ± 36.06 Gy. Significant differences were observed between the 5 patients with vaginal involvement and the remaining 14 at the level of PIBS +2 and PIBS: +47.60 Gy and +7.46 Gy, respectively (p = 0.023 and 0.03). The variations between delivered and prescribed doses at PIBS points were not significant. However, at International commission on radiation units and measurements rectovaginal point, the delivered dose was decreased by 1.43 ± 2.49 Gy from the planned dose (p = 0.019). The delivered doses at the four points were strongly correlated with the prescribed doses with R(2) ranging from 0.93 to 0.95. The movements of the applicator in regard of the PIBS point assessed with the Digital Imaging and Communications in Medicine coordinates were insignificant. The doses evaluated at PIBS points are not impacted by intrafractional movements. PIBS and PIBS +2 dose points allow distinguishing the plans of patients with vaginal infiltration. Further studies are needed to correlate these parameters with vaginal morbidity. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  14. Personnel Dose Assessment during Active Interrogation

    SciTech Connect

    Miller, Thomas Martin; Akkurt, Hatice; Patton, Bruce W

    2010-01-01

    A leading candidate in the detection of special nuclear material (SNM) is active interrogation (AI). Unlike passive interrogation, AI uses a source to enhance or create a detectable signal from SNM (usually fission), particularly in shielded scenarios or scenarios where the SNM has a low activity. The use of AI thus makes the detection of SNM easier or, in some scenarios, even enables previously impossible detection. During the development of AI sources, significant effort is put into determining the source strength required to detect SNM in specific scenarios. Usually during this process, but not always, an evaluation of personnel dose is also completed. In this instance personnel dose could involve any of the following: (1) personnel performing the AI; (2) unknown stowaways who are inside the object being interrogated; or (3) in clandestine interrogations, personnel who are known to be inside the object being interrogated but are unaware of the interrogation. In most instances, dose to anyone found smuggling SNM will be a secondary issue. However, for the organizations performing the AI, legal if not moral considerations should make dose to the personnel performing the AI, unknown stowaways, or innocent bystanders in clandestine interrogations a serious concern.

  15. Preliminary pathway analysis for YMP preclosure biosphere dose assessment

    SciTech Connect

    Wu, D.; Liu, N.; Tappen, J.J.; Tung, C.H.

    1998-05-13

    The preliminary preclosure biosphere dose assessment for the Yucca Mountain Project (YMP) involves the calculation of a radiation dose to a subsistence farmer living near the proposed Yucca Mountain repository. Eight radionuclides, H-3, Co-60, Kr-85, Sr-90, Ru-106, I-129, Cs-134, and Cs-137, are considered in this study. Radiation doses resulting from unit release rates of these radionuclides are analyzed. Total dose has been broken down into components that result from various exposure pathways. By using this approach, the most important pathways that deliver a radiation dose to a subsistence farmer can be clearly identified.

  16. Iodine-129 Dose in LLW Disposal Facility Performance Assessments

    SciTech Connect

    Wilhite, E.L.

    1999-10-15

    Iodine-129 has the lowest Performance Assessment derived inventory limit in SRS disposal facilities. Because iodine is concentrated in the body to one organ, the thyroid, it has been thought that dilution with stable iodine would reduce the dose effects of 129I.Examination of the dose model used to establish the Dose conversion factor for 129I shows that, at the levels considered in performance assessments of low-level waste disposal facilities, the calculated 129I dose already accounts for ingestion of stable iodine. At higher than normal iodine ingestion rates, the uptake of iodine by the thyroid itself decrease, which effectively cancels out the isotopic dilution effect.

  17. Measurement and assessment of radiation dose of astronauts in space

    NASA Astrophysics Data System (ADS)

    Zhang, Binquan; Sun, Yue-qiang; Yang, Chuibai; Zhang, Shenyi; Liang, Jinbao

    Astronauts in flight are exposed by the space radiation, which is mainly composed of proton, electron, heavy ion, and neutron. To assess the radiation risk, measurement and assessment of radiation dose of astronauts is indispensable. Especially, measurement for heavy ion radiation is most important as it contributes the major dose. Until now, most of the measurements and assessments of radiation dose of astronauts are based on the LET (Linear Energy Transfer) spectrum of space radiation. However, according to the ICRP Publication 123, energy and charge number of heavy ions should be measured in order to assess space radiation exposure to astronauts. In addition, from the publication, quality factors for each organs or tissues of astronauts are different and they should be calculated or measured independently. Here, a method to measure the energy and charge number of heavy ion and a voxel phantom based on the anatomy of Chinese adult male are presented for radiation dose assessment of astronauts.

  18. External radiation dose and cancer mortality among French nuclear workers: considering potential confounding by internal radiation exposure.

    PubMed

    Fournier, L; Laurent, O; Samson, E; Caër-Lorho, S; Laroche, P; Le Guen, B; Laurier, D; Leuraud, K

    2016-11-01

    French nuclear workers have detailed records of their occupational exposure to external radiation that have been used to examine associations with subsequent cancer mortality. However, some workers were also exposed to internal contamination by radionuclides. This study aims to assess the potential for bias due to confounding by internal contamination of estimates of associations between external radiation exposure and cancer mortality. A cohort of 59,004 workers employed for at least 1 year between 1950 and 1994 by CEA (Commissariat à l'Energie Atomique), AREVA NC, or EDF (Electricité de France) and badge-monitored for external radiation exposure were followed through 2004 to assess vital status and cause of death. A flag based on a workstation-exposure matrix defined four levels of potential for internal contamination. Standardized mortality ratios were assessed for each level of the internal contamination indicator. Poisson regression was used to quantify associations between external radiation exposure and cancer mortality, adjusting for potential internal contamination. For solid cancer, the mortality deficit tended to decrease as the levels of potential for internal contamination increased. For solid cancer and leukemia excluding chronic lymphocytic leukemia, adjusting the dose-response analysis on the internal contamination indicator did not markedly change the excess relative risk per Sievert of external radiation dose. This study suggests that in this cohort, neglecting information on internal dosimetry while studying the association between external dose and cancer mortality does not generate a substantial bias. To investigate more specifically the health effects of internal contamination, an effort is underway to estimate organ doses due to internal contamination.

  19. DOSE ASSESSMENTS FROM THE DISPOSAL OF LOW ...

    EPA Pesticide Factsheets

    Modeling the long-term performance of the RCRA-C disposal cell and potential doses to off-site receptors is used to derive maximum radionuclide specific concentrations in the wastes that would enable these wastes to be disposed of safely using the RCRA-C disposal cell technology. Modeling potential exposures to derive these waste acceptance concentrations involves modeling exposures to workers during storage, treatment and disposal of the wastes, as well as exposures to individuals after disposal operations have ceased. Post facility closure exposures can result from the slow expected degradation of the disposal cell over long time periods (one thousand years after disposal) and in advertent human intrusion. Provide a means of determining waste acceptance radionuclide concentrations for disposal of debris from radiological dispersal device incidents as well as low-activity wastes generated in commercial, medical and research activities, potentially serve as the technical basis for guidance on disposal of these materials.

  20. A Framework for "Fit for Purpose" Dose Response Assessment

    EPA Science Inventory

    The NRC report Science and Decisions: Advancing Risk Assessment made several recommendations to improve chemical risk assessment, with a focus on in-depth chronic dose-response assessments conducted by the U.S. Environmental Protection Agency. The recommendations addressed two ...

  1. A Framework for "Fit for Purpose" Dose Response Assessment

    EPA Science Inventory

    The NRC report Science and Decisions: Advancing Risk Assessment made several recommendations to improve chemical risk assessment, with a focus on in-depth chronic dose-response assessments conducted by the U.S. Environmental Protection Agency. The recommendations addressed two ...

  2. Angular absorbed dose dependence of internal radiation-generating devices in radiotherapy.

    PubMed

    Bevelacqua, J J

    2012-01-01

    The angular dependence of the absorbed dose from internal radiation-generating devices located within a tumor mass is investigated. Given the systematics of proton and heavy-ion differential scattering cross sections, candidate internal radiation-generating devices will have a relatively constant absorbed dose output beyond a critical angle. Inside this angle, the absorbed dose output is suppressed because elastic and inelastic differential cross sections are peaked in the beam direction. This peaking increases in severity as the particle energy increases and suggests internal radiation-generating devices must have a limited rotation capability to compensate for the depression in the absorbed dose for angles near the beam direction.

  3. Comparison of internal dose estimates obtained using organ-level, voxel S value, and Monte Carlo techniques

    SciTech Connect

    Grimes, Joshua; Celler, Anna

    2014-09-15

    Purpose: The authors’ objective was to compare internal dose estimates obtained using the Organ Level Dose Assessment with Exponential Modeling (OLINDA/EXM) software, the voxel S value technique, and Monte Carlo simulation. Monte Carlo dose estimates were used as the reference standard to assess the impact of patient-specific anatomy on the final dose estimate. Methods: Six patients injected with{sup 99m}Tc-hydrazinonicotinamide-Tyr{sup 3}-octreotide were included in this study. A hybrid planar/SPECT imaging protocol was used to estimate {sup 99m}Tc time-integrated activity coefficients (TIACs) for kidneys, liver, spleen, and tumors. Additionally, TIACs were predicted for {sup 131}I, {sup 177}Lu, and {sup 90}Y assuming the same biological half-lives as the {sup 99m}Tc labeled tracer. The TIACs were used as input for OLINDA/EXM for organ-level dose calculation and voxel level dosimetry was performed using the voxel S value method and Monte Carlo simulation. Dose estimates for {sup 99m}Tc, {sup 131}I, {sup 177}Lu, and {sup 90}Y distributions were evaluated by comparing (i) organ-level S values corresponding to each method, (ii) total tumor and organ doses, (iii) differences in right and left kidney doses, and (iv) voxelized dose distributions calculated by Monte Carlo and the voxel S value technique. Results: The S values for all investigated radionuclides used by OLINDA/EXM and the corresponding patient-specific S values calculated by Monte Carlo agreed within 2.3% on average for self-irradiation, and differed by as much as 105% for cross-organ irradiation. Total organ doses calculated by OLINDA/EXM and the voxel S value technique agreed with Monte Carlo results within approximately ±7%. Differences between right and left kidney doses determined by Monte Carlo were as high as 73%. Comparison of the Monte Carlo and voxel S value dose distributions showed that each method produced similar dose volume histograms with a minimum dose covering 90% of the volume (D90

  4. Monte Carlo assessment of computed tomography dose to tissue adjacent to the scanned volume.

    PubMed

    Boone, J M; Cooper, V N; Nemzek, W R; McGahan, J P; Seibert, J A

    2000-10-01

    The assessment of the radiation dose to internal organs or to an embryo or fetus is required on occasion for risk assessment or for comparing imaging studies. Limited resources hinder the ability to accurately assess the radiation dose received to locations outside the tissue volume actually scanned during computed tomography (CT). The purpose of this study was to assess peripheral doses and provide tabular data for dose evaluation. Validated Monte Carlo simulation techniques were used to compute the dose distribution along the length of water-equivalent cylindrical phantoms, 16 and 32 cm in diameter. For further validation, comparisons between physically measured and Monte Carlo-derived air kerma profiles were performed and showed excellent (1% to 2%) agreement. Polyenergetic x-ray spectra at 80, 100, 120, and 140 kVp with beam shaping filters were studied. Using 10(8) simulated photons input to the cylinders perpendicular to their long axis, line spread functions (LSF) of the dose distribution were determined at three depths in the cylinders (center, mid-depth, and surface). The LSF data were then used with appropriate mathematics to compute dose distributions along the long axis of the cylinder. The dose distributions resulting from helical (pitch = 1.0) scans and axial scans were approximately equivalent. Beyond about 3 cm from the edge of the CT scanned tissue volume, the fall-off of radiation dose was exponential. A series of tables normalized at 100 milliampere seconds (mAs) were produced which allow the straight-forward assessment of dose within and peripheral to the CT scanned volume. The tables should be useful for medical physicists and radiologists in the estimation of dose to sites beyond the edge of the CT scanned volume.

  5. The International Arctic Seas Assessment Project

    SciTech Connect

    Linsley, G.S.; Sjoeblom, K.L.

    1994-07-01

    The International Arctic Seas Assessment Project (IASAP) was initiated in 1993 to address widespread concern over the possible health and environmental impacts associated with the radioactive waste dumped into the shallow waters of the Arctic Seas. This article discusses the project with these general topics: A brief history of dumping activities; the international control system; perspectives on arctic Seas dumping; the IASAP aims and implementation; the IASAP work plan and progress. 2 figs.

  6. Internal Mammary Lymph Node Irradiation Contributes to Heart Dose in Breast Cancer

    SciTech Connect

    Chargari, Cyrus; Castadot, Pierre; MacDermed, Dhara; Vandekerkhove, Christophe; Bourgois, Nicolas; Van Houtte, Paul; Magne, Nicolas

    2010-10-01

    We assessed the impact of internal mammary chain radiotherapy (IMC RT) to the radiation dose received by the heart in terms of heart dose-volume histogram (DVH). Thirty-six consecutive breast cancer patients presenting with indications for IMC RT were enrolled in a prospective study. The IMC was treated by a standard conformal RT technique (50 Gy). For each patient, a cardiac DVH was generated by taking into account the sole contribution of IMC RT. Cardiac HDV were compared according to breast cancer laterality and the type of previous surgical procedure, simple mastectomy or breast conservative therapy (BCT). The contribution of IMC RT to the heart dose was significantly greater for patients with left-sided versus right-sided tumors (13.8% and 12.8% for left-sided tumors versus 3.9% and 4.2% for right-sided tumors in the BCT group and the mastectomy group, respectively; p < 0.0001). There was no statistically significant difference in IMC contribution depending on the initial surgical procedure. IMC RT contributes to cardiac dose for both left-sided and right-sided breast cancers, although the relative contribution is greater in patients with left-sided tumors.

  7. Estimates of intakes and internal doses from ingestion of {sup 32}P at MIT and NIH

    SciTech Connect

    Stabin, M.G.; Toohey, R.E.

    1996-06-01

    A researcher at Massachusetts Institute of Technology (MIT) became internally contaminated with {sup 32}P, probably due to an intentional act. The incident occurred on or about 14 August 1995. Subsequent measurement of activity in urine and a single whole body count were used to estimate the individual`s intake, with the assumption of ingestion as the route of intake. Two separate Sets of urine data were analyzed-one supplied by MIT and one from independent analyses of urine samples conducted at Oak Ridge Institute for Science and Education (ORISE); the former data set contained 35 samples, the latter 49. In addition, the results of 35 whole body counts, provided by MIT from a chair-type counter calibrated for 32p, were used to obtain a separate estimate of intake. The kinetic model for 32P proposed in ICRP Publication 30 and implemented in NUREG/CR-4884 was used to interpret the data. The data were analyzed using both the weighted and unweighted least squares techniques. All of the intake estimates were in very good agreement with each other, ranging from 18-22 MBq. Based on the dose model in ICRP 30, this would indicate a committed effective dose equivalent of 38-46 mSv. The incident was helpful in assessing the value of the least squares techniques in determining estimates of intake and dose. The ICRP model tended to slightly overestimate the whole body retention data and underestimate the urinary excretion at later times. Further results obtained by visual best fit and development of an individual-specific kinetic and dose model will also be discussed. This incident was quite similar to another case of ingestion of 32p that occurred at the National Institute of Health (NIH) on 28 June 1995. Dose assessment for the NIH case will also be presented if the data are available for public release.

  8. Interactive Rapid Dose Assessment Model (IRDAM): user's guide

    SciTech Connect

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    As part of the continuing emphasis on emergency preparedness the US Nuclear Regulatory Commission (NRC) sponsored the development of a rapid dose assessment system by Pacific Northwest Laboratory (PNL). This system, the Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program for rapidly assessing the radiological impact of accidents at nuclear power plants. This User's Guide provides instruction in the setup and operation of the equipment necessary to run IRDAM. Instructions are also given on how to load the magnetic disks and access the interactive part of the program. Two other companion volumes to this one provide additional information on IRDAM. Reactor Accident Assessment Methods (NUREG/CR-3012, Volume 2) describes the technical bases for IRDAM including methods, models and assumptions used in calculations. Scenarios for Comparing Dose Assessment Models (NUREG/CR-3012, Volume 3) provides the results of calculations made by IRDAM and other models for specific accident scenarios.

  9. Respiratory dose assessment of inhaled particles: continuing progress

    EPA Science Inventory

    Internal dose is a key factor for determining the health risk ofinhaled pollutant particles on the one hand and the efficacy ofdrug inhalantsonthe other. Accurateestimation ofrespiratorydose, however, is a difficult task because multiple factors come to play roles in the process....

  10. Respiratory dose assessment of inhaled particles: continuing progress

    EPA Science Inventory

    Internal dose is a key factor for determining the health risk ofinhaled pollutant particles on the one hand and the efficacy ofdrug inhalantsonthe other. Accurateestimation ofrespiratorydose, however, is a difficult task because multiple factors come to play roles in the process....

  11. Automated size-specific CT dose monitoring program: Assessing variability in CT dose

    SciTech Connect

    Christianson, Olav; Li Xiang; Frush, Donald; Samei, Ehsan

    2012-11-15

    Purpose: The potential health risks associated with low levels of ionizing radiation have created a movement in the radiology community to optimize computed tomography (CT) imaging protocols to use the lowest radiation dose possible without compromising the diagnostic usefulness of the images. Despite efforts to use appropriate and consistent radiation doses, studies suggest that a great deal of variability in radiation dose exists both within and between institutions for CT imaging. In this context, the authors have developed an automated size-specific radiation dose monitoring program for CT and used this program to assess variability in size-adjusted effective dose from CT imaging. Methods: The authors radiation dose monitoring program operates on an independent health insurance portability and accountability act compliant dosimetry server. Digital imaging and communication in medicine routing software is used to isolate dose report screen captures and scout images for all incoming CT studies. Effective dose conversion factors (k-factors) are determined based on the protocol and optical character recognition is used to extract the CT dose index and dose-length product. The patient's thickness is obtained by applying an adaptive thresholding algorithm to the scout images and is used to calculate the size-adjusted effective dose (ED{sub adj}). The radiation dose monitoring program was used to collect data on 6351 CT studies from three scanner models (GE Lightspeed Pro 16, GE Lightspeed VCT, and GE Definition CT750 HD) and two institutions over a one-month period and to analyze the variability in ED{sub adj} between scanner models and across institutions. Results: No significant difference was found between computer measurements of patient thickness and observer measurements (p= 0.17), and the average difference between the two methods was less than 4%. Applying the size correction resulted in ED{sub adj} that differed by up to 44% from effective dose estimates

  12. Dosimetry software Hermes Internal Radiation Dosimetry: from quantitative image reconstruction to voxel-level absorbed dose distribution.

    PubMed

    Hippeläinen, Eero T; Tenhunen, Mikko J; Mäenpää, Hanna O; Heikkonen, Jorma J; Sohlberg, Antti O

    2017-05-01

    The aim of this work is to validate a software package called Hermes Internal Radiation Dosimetry (HIRD) for internal dose assessment tailored for clinical practice. The software includes all the necessary steps to perform voxel-level absorbed dose calculations including quantitative reconstruction, image coregistration and volume of interest tools. The basics of voxel-level dosimetry methods and implementations to HIRD software are reviewed. Then, HIRD is validated using simulated SPECT/CT data and data from Lu-DOTATATE-treated patients by comparing absorbed kidney doses with OLINDA/EXM-based dosimetry. In addition, electron and photon dose components are studied separately in an example patient case. The simulation study showed that HIRD can reproduce time-activity curves accurately and produce absorbed doses with less than 10% error for the kidneys, liver and spleen. From the patient data, the absorbed kidney doses calculated using HIRD and using OLINDA/EXM were highly correlated (Pearson's correlation coefficient, r=0.98). From Bland-Altman plot analysis, an average absorbed dose difference of -2% was found between the methods. In addition, we found that in Lu-DOTATATE-treated patients, photons can contribute over 10% of the kidney's total dose and is partly because of cross-irradiation from high-uptake lesions close to the kidneys. HIRD is a straightforward voxel-level internal dosimetry software. Its clinical utility was verified with simulated and clinical Lu-DOTATATE-treated patient data. Patient studies also showed that photon contribution towards the total dose can be relatively high and voxel-level dose calculations can be valuable in cases where the target organ is in close proximity to high-uptake organs.

  13. Radiation dose assessment of exposure to depleted uranium.

    PubMed

    Li, Wei Bo; Gerstmann, Udo C; Höllriegl, Vera; Szymczak, Wilfried; Roth, Paul; Hoeschen, Christoph; Oeh, Uwe

    2009-07-01

    Depleted uranium (DU) is claimed to contribute to human health problems, known as the Gulf War Syndrome and the Balkan Syndrome. Quantitative radiation dose is required to estimate the health risk of DU materials. The influences of the solubility parameters in the human alimentary tract and the respiratory tract systems and the aerosol particles size on the radiation dose of DU materials were evaluated. The dose conversion factor of daily urinary excretion of DU is provided. The retention and excretion of DU in the human body after a contamination at a wound site were predicted. Dose coefficients of DU after ingestion and inhalation were calculated using the solubility parameters of the DU corrosion products in simulated gastric and simulated lung fluid, which were determined in the Helmholtz Zentrum München. (238)U is the main radiation dose contributor per 1 Bq of DU materials. The dose coefficients of DU materials were estimated to be 3.5 x 10(-8) and 2.1 x 10(-6) Sv Bq(-1) after ingestion and inhalation for members of the public. The ingestion dose coefficient of DU materials is about 75% of the natural uranium value. The inhalation dose coefficient of DU material is in between those for Type M and Type S according to the category for inhaled materials defined by the International Commission on Radiological Protection. Radiation dose possibly received from DU materials can directly be estimated by using the dose conversion factor provided in this study, if daily urinary excretion of DU is measured.

  14. Identification and dose assessment of irradiated cumin by EPR spectrometry.

    PubMed

    Abdel-Fattah, A A

    2002-03-01

    The use of electron paramagnetic resonance spectroscopy to accurately distinguish irradiated from unirradiated cumin and assess the absorbed dose to radiation-processed cumin is examined. The results were successful for identifying both irradiated and unirradiated cumin. Additive reirradiation of the cumin produces a reproducible dose response function, which can be used to assess the initial dose by back-extrapolation. Third-degree polynomial and exponential functions were used to fit the EPR signal/dose curves. It was found that the 3rd degree polynomial function provides satisfactory results without correction for decay of free radicals. The exponential fit to the data cannot be used without correction of decay of free radicals. The stability of the radiation-induced EPR signal of irradiated cumin was studied over a storage period of 6 months. The additive reirradiation of some samples was carried out at different storage times (10, 20 and 30 days) after initial irradiation.

  15. Estimation of Internal Radiation Dose from both Immediate Releases and Continued Exposures to Contaminated Materials

    SciTech Connect

    Napier, Bruce A.

    2012-03-26

    A brief description is provided of the basic concepts related to 'internal dose' and how it differs from doses that result from radioactive materials and direct radiation outside of the body. The principles of radiation dose reconstruction, as applied to both internal and external doses, is discussed based upon a recent publication prepared by the US National Council on Radiation Protection and Measurements. Finally, ideas are introduced related to residual radioactive contamination in the environment that has resulted from the releases from the damaged reactors and also to the management of wastes that may be generated in both regional cleanup and NPP decommissioning.

  16. External dose assessment in the Ukraine following the Chernobyl accident

    NASA Astrophysics Data System (ADS)

    Frazier, Remi Jordan Lesartre

    While the physiological effects of radiation exposure have been well characterized in general, it remains unclear what the relationship is between large-scale radiological events and psychosocial behavior outcomes in individuals or populations. To investigate this, the National Science Foundation funded a research project in 2008 at the University of Colorado in collaboration with Colorado State University to expand the knowledge of complex interactions between radiation exposure, perception of risk, and psychosocial behavior outcomes by modeling outcomes for a representative sample of the population of the Ukraine which had been exposed to radiocontaminant materials released by the reactor accident at Chernobyl on 26 April 1986. In service of this project, a methodology (based substantially on previously published models specific to the Chernobyl disaster and the Ukrainian population) was developed for daily cumulative effective external dose and dose rate assessment for individuals in the Ukraine for as a result of the Chernobyl disaster. A software platform was designed and produced to estimate effective external dose and dose rate for individuals based on their age, occupation, and location of residence on each day between 26 April 1986 and 31 December 2009. A methodology was developed to transform published 137Cs soil deposition contour maps from the Comprehensive Atlas of Caesium Deposition on Europe after the Chernobyl Accident into a geospatial database to access these data as a radiological source term. Cumulative effective external dose and dose rate were computed for each individual in a 703-member cohort of Ukrainians randomly selected to be representative of the population of the country as a whole. Error was estimated for the resulting individual dose and dose rate values with Monte Carlo simulations. Distributions of input parameters for the dose assessment methodology were compared to computed dose and dose rate estimates to determine which

  17. Assessment of the effective dose equivalent for external photon radiation

    SciTech Connect

    Reece, W.D.; Poston, J.W.; Xu, X.G. )

    1993-02-01

    Beginning in January 1994, US nuclear power plants must change the way that they determine the radiation exposure to their workforce. At that time, revisions to Title 10 Part 20 of the Code of Federal Regulations will be in force requiring licensees to evaluate worker radiation exposure using a risk-based methodology termed the effective dose equivalent.'' A research project was undertaken to improve upon the conservative method presently used for assessing effective dose equivalent. In this project effective dose equivalent was calculated using a mathematical model of the human body, and tracking photon interactions for a wide variety of radiation source geometries using Monte Carlo computer code simulations. Algorithms were then developed to relate measurements of the photon flux on the surface of the body (as measured by dosimeters) to effective dose equivalent. This report (Volume I of a two-part study) describes: the concept of effective dose equivalent, the evolution of the concept and its incorporation into regulations, the variations in human organ susceptibility to radiation, the mathematical modeling and calculational techniques used, the results of effective dose equivalent calculations for a broad range of photon energiesand radiation source geometries. The study determined that for beam radiation sources the highest effective dose equivalent occurs for beams striking the front of the torso. Beams striking the rear of the torsoproduce the next highest effective dose equivalent, with effective dose equivalent falling significantly as one departs from these two orientations. For point sources, the highest effective dose equivalent occurs when the sources are in contact with the body on the front of the torso. For females the highest effective dose equivalent occurs when the source is on the sternum, for males when it is on the gonads.

  18. EYE LENS EXPOSURE TO MEDICAL STAFF PERFORMING ELECTROPHYSIOLOGY PROCEDURES: DOSE ASSESSMENT AND CORRELATION TO PATIENT DOSE.

    PubMed

    Ciraj-Bjelac, Olivera; Antic, Vojislav; Selakovic, Jovana; Bozovic, Predrag; Arandjic, Danijela; Pavlovic, Sinisa

    2016-12-01

    The purpose of this study was to assess the patient exposure and staff eye dose levels during implantation procedures for all types of pacemaker therapy devices performed under fluoroscopic guidance and to investigate potential correlation between patients and staff dose levels. The mean eye dose during pacemaker/defibrillator implementation was 12 µSv for the first operator, 8.7 µSv for the second operator/nurse and 0.50 µSv for radiographer. Corresponding values for cardiac resynchronisation therapy procedures were 30, 26 and 2.0 µSv, respectively. Significant (p < 0.01) correlation between the eye dose and the kerma-area product was found for the first operator and radiographers, but not for other staff categories. The study revealed eye dose per procedure and eye dose normalised to patient dose indices for different staff categories and provided an input for radiation protection in electrophysiology procedures. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. 3D-printed applicators for high dose rate brachytherapy: Dosimetric assessment at different infill percentage.

    PubMed

    Ricotti, Rosalinda; Vavassori, Andrea; Bazani, Alessia; Ciardo, Delia; Pansini, Floriana; Spoto, Ruggero; Sammarco, Vittorio; Cattani, Federica; Baroni, Guido; Orecchia, Roberto; Jereczek-Fossa, Barbara Alicja

    2016-12-01

    Dosimetric assessment of high dose rate (HDR) brachytherapy applicators, printed in 3D with acrylonitrile butadiene styrene (ABS) at different infill percentage. A low-cost, desktop, 3D printer (Hamlet 3DX100, Hamlet, Dublin, IE) was used for manufacturing simple HDR applicators, reproducing typical geometries in brachytherapy: cylindrical (common in vaginal treatment) and flat configurations (generally used to treat superficial lesions). Printer accuracy was investigated through physical measurements. The dosimetric consequences of varying the applicator's density by tuning the printing infill percentage were analysed experimentally by measuring depth dose profiles and superficial dose distribution with Gafchromic EBT3 films (International Specialty Products, Wayne, NJ). Dose distributions were compared to those obtained with a commercial superficial applicator. Measured printing accuracy was within 0.5mm. Dose attenuation was not sensitive to the density of the material. Surface dose distribution comparison of the 3D printed flat applicators with respect to the commercial superficial applicator showed an overall passing rate greater than 94% for gamma analysis with 3% dose difference criteria, 3mm distance-to-agreement criteria and 10% dose threshold. Low-cost 3D printers are a promising solution for the customization of the HDR brachytherapy applicators. However, further assessment of 3D printing techniques and regulatory materials approval are required for clinical application. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  20. Peak Dose Assessment for Proposed DOE-PPPO Authorized Limits

    SciTech Connect

    Maldonado, Delis

    2012-06-01

    The Oak Ridge Institute for Science and Education (ORISE), a U.S. Department of Energy (DOE) prime contractor, was contracted by the DOE Portsmouth/Paducah Project Office (DOE-PPPO) to conduct a peak dose assessment in support of the Authorized Limits Request for Solid Waste Disposal at Landfill C-746-U at the Paducah Gaseous Diffusion Plant (DOE-PPPO 2011a). The peak doses were calculated based on the DOE-PPPO Proposed Single Radionuclides Soil Guidelines and the DOE-PPPO Proposed Authorized Limits (AL) Volumetric Concentrations available in DOE-PPPO 2011a. This work is provided as an appendix to the Dose Modeling Evaluations and Technical Support Document for the Authorized Limits Request for the C-746-U Landfill at the Paducah Gaseous Diffusion Plant, Paducah, Kentucky (ORISE 2012). The receptors evaluated in ORISE 2012 were selected by the DOE-PPPO for the additional peak dose evaluations. These receptors included a Landfill Worker, Trespasser, Resident Farmer (onsite), Resident Gardener, Recreational User, Outdoor Worker and an Offsite Resident Farmer. The RESRAD (Version 6.5) and RESRAD-OFFSITE (Version 2.5) computer codes were used for the peak dose assessments. Deterministic peak dose assessments were performed for all the receptors and a probabilistic dose assessment was performed only for the Offsite Resident Farmer at the request of the DOE-PPPO. In a deterministic analysis, a single input value results in a single output value. In other words, a deterministic analysis uses single parameter values for every variable in the code. By contrast, a probabilistic approach assigns parameter ranges to certain variables, and the code randomly selects the values for each variable from the parameter range each time it calculates the dose (NRC 2006). The receptor scenarios, computer codes and parameter input files were previously used in ORISE 2012. A few modifications were made to the parameter input files as appropriate for this effort. Some of these changes

  1. An analytical model for calculating internal dose conversion coefficients for non-human biota.

    PubMed

    Amato, Ernesto; Italiano, Antonio

    2014-05-01

    To assess the radiation burden of non-human living organisms, dose coefficients are available in the literature, precalculated by assuming an ellipsoidal shape of each organism. A previously developed analytical method was applied for the determination of absorbed fractions inside ellipsoidal volumes from alpha, beta, and gamma radiations to the calculation of dose conversion coefficients (DCCs) for 15 reference organisms, animals and plants, either terrestrial, amphibian, or aquatic, and six radionuclides ((14)C, (90)Sr, (60)Co, (137)Cs, (238)U, and (241)Am). The results were compared with the reference values reported in Publication 108 of the International Commission on Radiological Protection, in which a different calculation approach for DCCs was employed. The results demonstrate that the present analytical method, originally intended for applications in internal dosimetry of nuclear medicine therapy, gives consistent results for all the beta-, beta-gamma-, and alpha-emitting radionuclides tested in a wide range of organism masses, between 8 mg and 1.3 kg. The applicability of the method proposed can take advantage from its ease of implementation in an ordinary electronic spreadsheet, allowing to calculate, for virtually all possible radionuclide emission spectra, the DCCs for ellipsoidal models of non-human living organisms in the environment.

  2. Predictors of polycyclic aromatic hydrocarbon exposure and internal dose in inner city Baltimore children

    PubMed Central

    Peters, Kamau O.; Williams, D’ Ann L.; Abubaker, Salahadin; Curtin-Brosnan, Jean; McCormack, Meredith C.; Peng, Roger; Breysse, Patrick N.; Matsui, Elizabeth C.; Hansel, Nadia N.; Diette, Gregory B.; Strickland, Paul T.

    2017-01-01

    Polycyclic aromatic hydrocarbons (PAHs), the by-products of incomplete combustion of organic materials, are commonly found on particulate matter (PM) and have been associated with the development of asthma and asthma exacerbation in urban populations. We examined time spent in the home and outdoors as predictors of exposures to airborne PAHs and measured urinary 1-hydroxypyrene-glucuronide (1-OHPG) as internal dose of PAHs in 118 children aged 5–12 years from Baltimore, MD. During weeklong periods (Saturday–Saturday) in each of four seasons: daily activities were assessed using questionnaires, indoor air nicotine and PM concentrations were monitored, and urine specimens were collected on Tuesday (day 3) and Saturday (day 7) for measurement of 1-OHPG. Time spent in non-smoking homes was associated with significantly decreased 1-OHPG concentration in urine (β = −0.045, 95% CI (−0.076, −0.013)), and secondhand smoke (SHS) exposures modified these associations, with higher urinary 1-OHPG concentrations in children spending time in smoking homes than non-smoking homes (P-value for interaction = 0.012). Time spent outdoors was associated with increased urinary 1-OHPG concentrations (β=0.097, 95% CI (0.037, 0.157)) in boys only. Our results suggest that SHS and ambient (outdoor) air pollution contribute to internal dose of PAHs in inner city children. PMID:27966668

  3. Application of the International Life Sciences Institute Key Events Dose-Response Framework to food contaminants.

    PubMed

    Fenner-Crisp, Penelope A

    2012-12-01

    Contaminants are undesirable constituents in food. They may be formed during production of a processed food, present as a component in a source material, deliberately added to substitute for the proper substance, or the consequence of poor food-handling practices. Contaminants may be chemicals or pathogens. Chemicals generally degrade over time and become of less concern as a health threat. Pathogens have the ability to multiply, potentially resulting in an increased threat level. Formal structures have been lacking for systematically generating and evaluating hazard and exposure data for bioactive agents when problem situations arise. We need to know what the potential risk may be to determine whether intervention to reduce or eliminate contact with the contaminant is warranted. We need tools to aid us in assembling and assessing all available relevant information in an expeditious and scientifically sound manner. One such tool is the International Life Sciences Institute (ILSI) Key Events Dose-Response Framework (KEDRF). Developed as an extension of the WHO's International Program on Chemical Safety/ILSI mode of action/human relevance framework, it allows risk assessors to understand not only how a contaminant exerts its toxicity but also the dose response(s) for each key event and the ultimate outcome, including whether a threshold exists. This presentation will illustrate use of the KEDRF with case studies included in its development (chloroform and Listeriaonocytogenes) after its publication in the peer-reviewed scientific literature (chromium VI) and in a work in progress (3-monochloro-1, 2-propanediol).

  4. INTEGRATED RISK ASSESSMENT - RESULTS FROM AN INTERNATIONAL WORKSHOP

    EPA Science Inventory

    The WHO International Programme on Chemical Safety and international partners have developed a framework for integrated assessment of human health and ecological risks and four case studies. An international workshop was convened to consider how ecological and health risk assess...

  5. INTEGRATED RISK ASSESSMENT - RESULTS FROM AN INTERNATIONAL WORKSHOP

    EPA Science Inventory

    The WHO International Programme on Chemical Safety and international partners have developed a framework for integrated assessment of human health and ecological risks and four case studies. An international workshop was convened to consider how ecological and health risk assess...

  6. Radiological assessment of worker doses during sludge mobilization and removal at the Melton Valley storage tanks

    SciTech Connect

    Kerr, G.D.; Coleman, R.L.; Kocher, D.C.; Wynn, C.C.

    1996-12-17

    This report presents an assessment of potential radiation doses to workers during mobilization and removal of contaminated sludges from the Melton Valley Storage Tanks at Oak Ridge National Laboratory. The assessment is based on (1) measurements of radionuclide concentrations in sludge and supernatant liquid samples from the waste storage tanks, (2) measurements of gamma radiation levels in various areas that will be accessed by workers during normal activities, (3) calculations of gamma radiation levels for particular exposure situations, especially when the available measurements are not applicable, and (4) assumed scenarios for worker activities in radiation areas. Only doses from external exposure are estimated in this assessment. Doses from internal exposure are assumed to be controlled by containment of radioactive materials or respiratory protection of workers and are not estimated.

  7. Fetal and maternal dose assessment for diagnostic scans during pregnancy

    NASA Astrophysics Data System (ADS)

    Rafat Motavalli, Laleh; Miri Hakimabad, Hashem; Hoseinian Azghadi, Elie

    2016-05-01

    Despite the concerns about prenatal exposure to ionizing radiation, the number of nuclear medicine examinations performed for pregnant women increased in the past decade. This study attempts to better quantify radiation doses due to diagnostic nuclear medicine procedures during pregnancy with the help of our recently developed 3, 6, and 9 month pregnant hybrid phantoms. The reference pregnant models represent the adult female international commission on radiological protection (ICRP) reference phantom as a base template with a fetus in her gravid uterus. Six diagnostic scintigraphy scans using different radiopharmaceuticals were selected as typical diagnostic nuclear medicine procedures. Furthermore, the biokinetic data of radioiodine was updated in this study. A compartment representing iodide in fetal thyroid was addressed explicitly in the biokinetic model. Calculations were performed using the Monte Carlo transport method. Tabulated dose coefficients for both maternal and fetal organs are provided. The comparison was made with the previously published fetal doses calculated for stylized pregnant female phantoms. In general, the fetal dose in previous studies suffers from an underestimation of up to 100% compared to fetal dose at organ level in this study. A maximum of difference in dose was observed for the fetal thyroid compared to the previous studies, in which the traditional models did not contain the fetal thyroid. Cumulated activities of major source organs are primarily responsible for the discrepancies in the organ doses. The differences in fetal dose depend on several other factors including chord length distribution between fetal organs and maternal major source organs, and anatomical differences according to gestation periods. Finally, considering the results of this study, which was based on the realistic pregnant female phantoms, a more informed evaluation of the risks and benefits of the different procedures could be made.

  8. Radiation dose reduction in paediatric coronary computed tomography: assessment of effective dose and image quality.

    PubMed

    Habib Geryes, Bouchra; Calmon, Raphael; Khraiche, Diala; Boddaert, Nathalie; Bonnet, Damien; Raimondi, Francesca

    2016-07-01

    To assess the impact of different protocols on radiation dose and image quality for paediatric coronary computed tomography (cCT). From January-2012 to June-2014, 140 children who underwent cCT on a 64-slice scanner were included. Two consecutive changes in imaging protocols were performed: 1) the use of adaptive statistical iterative reconstruction (ASIR); 2) the optimization of acquisition parameters. Effective dose (ED) was calculated by conversion of the dose-length product. Image quality was assessed as excellent, good or with significant artefacts. Patients were divided in three age groups: 0-4, 5-7 and 8-18 years. The use of ASIR combined to the adjustment of scan settings allowed a reduction in the median ED of 58 %, 82 % and 85 % in 0-4, 5-7 and 8-18 years group, respectively (7.3 ± 1.4 vs 3.1 ± 0.7 mSv, 5.5 ± 1.6 vs 1 ± 1.9 mSv and 5.3 ± 5.0 vs 0.8 ± 2.0 mSv, all p < 0,05). Prospective protocol was used in 51 % of children. The reduction in radiation dose was not associated with reduction in diagnostic image quality as assessed by the frequency of coronary segments with excellent or good image quality (88 %). cCT can be obtained at very low radiation doses in children using ASIR, and prospective acquisition with optimized imaging parameters. • Using ASIR allows 25 % to 41 % reduction in the ED. • Prospective protocol is used up to 51 % of children after premedication. • Low dose is possible using ASIR and optimized prospective paediatric cCT.

  9. Prenatal Perfluorooctanoic Acid Exposure in CD-1 Mice: Low-Dose Developmental Effects and Internal Dosimetry

    PubMed Central

    Macon, Madisa B.; Villanueva, LaTonya R.; Tatum-Gibbs, Katoria; Zehr, Robert D.; Strynar, Mark J.; Stanko, Jason P.; White, Sally S.; Helfant, Laurence

    2011-01-01

    Perfluorooctanoic acid (PFOA) is an environmental contaminant that causes adverse developmental effects in laboratory animals. To investigate the low-dose effects of PFOA on offspring, timed-pregnant CD-1 mice were gavage dosed with PFOA for all or half of gestation. In the full-gestation study, mice were administered 0, 0.3, 1.0, and 3.0 mg PFOA/kg body weight (BW)/day from gestation days (GD) 1–17. In the late-gestation study, mice were administered 0, 0.01, 0.1, and 1.0 mg PFOA/kg BW/day from GD 10–17. Exposure to PFOA significantly (p < 0.05) increased offspring relative liver weights in all treatment groups in the full-gestation study and in the 1.0 mg PFOA/kg group in the late-gestation study. In both studies, the offspring of all PFOA-treated dams exhibited significantly stunted mammary epithelial growth as assessed by developmental scoring. At postnatal day 21, mammary glands from the 1.0 mg/kg GD 10–17 group had significantly less longitudinal epithelial growth and fewer terminal end buds compared with controls (p < 0.05). Evaluation of internal dosimetry in offspring revealed that PFOA concentrations remained elevated in liver and serum for up to 6 weeks and that brain concentrations were low and undetectable after 4 weeks. These data indicate that PFOA-induced effects on mammary tissue (1) occur at lower doses than effects on liver weight in CD-1 mice, an observation that may be strain specific, and (2) persist until 12 weeks of age following full-gestational exposure. Due to the low-dose sensitivity of mammary glands to PFOA in CD-1 mice, a no observable adverse effect level for mammary developmental delays was not identified in these studies. PMID:21482639

  10. Integrated Worker Radiation Dose Assessment for the K Basins

    SciTech Connect

    NELSON, J.V.

    1999-10-27

    This report documents an assessment of the radiation dose workers at the K Basins are expected to receive in the process of removing spent nuclear fuel from the storage basins. The K Basins (K East and K West) are located in the Hanford 100K Area.

  11. The Assessment of Effective Dose Equivalent Using Personnel Dosimeters

    NASA Astrophysics Data System (ADS)

    Xu, Xie

    From January 1994, U.S. nuclear plants must develop a technically rigorous approach for determining the effective dose equivalent for their work forces. This dissertation explains concepts associated with effective dose equivalent and describes how to assess effective dose equivalent by using conventional personnel dosimetry measurements. A Monte Carlo computer code, MCNP, was used to calculate photon transport through a model of the human body. Published mathematical phantoms of the human adult male and female were used to simulate irradiation from a variety of external radiation sources in order to calculate organ and tissue doses, as well as effective dose equivalent using weighting factors from ICRP Publication 26. The radiation sources considered were broad parallel photon beams incident on the body from 91 different angles and isotropic point sources located at 234 different locations in contact with or near the body. Monoenergetic photons of 0.08, 0.3, and 1.0 MeV were considered for both sources. Personnel dosimeters were simulated on the surface of the body and exposed to with the same sources. From these data, the influence of dosimeter position on dosimeter response was investigated. Different algorithms for assessing effective dose equivalent from personnel dosimeter responses were proposed and evaluated. The results indicate that the current single-badge approach is satisfactory for most common exposure situations encountered in nuclear plants, but additional conversion factors may be used when more accurate results become desirable. For uncommon exposures involving source situated at the back of the body or source located overhead, the current approach of using multi-badges and assigning the highest dose is overly conservative and unnecessarily expensive. For these uncommon exposures, a new algorithm, based on two dosimeters, one on the front of the body and another one on the back of the body, has been shown to yield conservative assessment of

  12. Assessing the dose-dependency of allometric scaling performance using physiologically based pharmacokinetic modeling.

    PubMed

    Kirman, C R; Sweeney, L M; Meek, M E; Gargas, M L

    2003-12-01

    The performance of allometric scaling of dose as a power of body weight under a variety of extrapolation conditions with respect to species, route, exposure intensity, and mechanism/mode of action, remains untested in many cases. In this paper, animal-human internal dose ratio comparisons have been developed for 12 chemicals (benzene, carbon tetrachloride, chloroform, diisopropylfluorophosphate, ethanol, ethylene oxide, methylene chloride, methylmercury, styrene, tetrachloroethene, trichloroethene, and vinyl chloride). This group of predominantly volatile and lipophilic chemicals was selected on the basis that their kinetics have been well-studied and can be predicted in mice, rats, and humans using physiologically based pharmacokinetic (PBPK) models. PBPK model predictions were compared to the allometric scaling predictions for interspecies extrapolation. Recommendations for the application of the allometric scaling are made with reference to internal dose measure (mode of action) and concentration level. The results of this assessment generally support the use of scaling factors recommended in the published literature, which includes scaling factors of 1.0 for risk assessments in which toxicity is attributed to the parent chemical or stable metabolite, and -0.75 for dose-response assessments in which toxicity is attributed to the formation of a reactive metabolite from an inhaled compound. A scaling factor of 0.75 is recommended for dose-response assessments of orally administered compounds in which toxicity is attributed to the parent chemical or stable metabolite and 1.0 for risk assessments in which toxicity is attributed to the formation of a reactive metabolite from a compound administered by the oral route. A dose-dependency in the results suggests that the scaling factors appropriate at high exposures may differ from those at low exposures, primarily due to the impact of saturable metabolism.

  13. Estimating the Radiation Dose to the Fetus in Prophylactic Internal Iliac Artery Balloon Occlusion: Three Cases

    PubMed Central

    Kai, Kentaro; Hamada, Tomohiro; Yuge, Akitoshi; Kiyosue, Hiro; Nishida, Yoshihiro; Nasu, Kaei; Narahara, Hisashi

    2015-01-01

    Background. Although radiation exposure is of great concern to expecting patients, little information is available on the fetal radiation dose associated with prophylactic internal iliac artery balloon occlusion (IIABO). Here we estimated the fetal radiation dose associated with prophylactic IIABO in Caesarean section (CS). Cases. We report our experience with the IIABO procedure in three consecutive patients with suspected placenta previa/accreta. Fetal radiation dose measurements were conducted prior to each CS by using an anthropomorphic phantom. Based on the simulated value, we calculated the fetal radiation dose as the absorbed dose. We found that the fetal radiation doses ranged from 12.88 to 31.6 mGy. The fetal radiation dose during the prophylactic IIABOs did not exceed 50 mGy. Conclusion. The IIABO procedure could result in a very small increase in the risk of harmful effects to the fetus. PMID:26180648

  14. Technical Note: scuda: A software platform for cumulative dose assessment.

    PubMed

    Park, Seyoun; McNutt, Todd; Plishker, William; Quon, Harry; Wong, John; Shekhar, Raj; Lee, Junghoon

    2016-10-01

    Accurate tracking of anatomical changes and computation of actually delivered dose to the patient are critical for successful adaptive radiation therapy (ART). Additionally, efficient data management and fast processing are practically important for the adoption in clinic as ART involves a large amount of image and treatment data. The purpose of this study was to develop an accurate and efficient Software platform for CUmulative Dose Assessment (scuda) that can be seamlessly integrated into the clinical workflow. scuda consists of deformable image registration (DIR), segmentation, dose computation modules, and a graphical user interface. It is connected to our image PACS and radiotherapy informatics databases from which it automatically queries/retrieves patient images, radiotherapy plan, beam data, and daily treatment information, thus providing an efficient and unified workflow. For accurate registration of the planning CT and daily CBCTs, the authors iteratively correct CBCT intensities by matching local intensity histograms during the DIR process. Contours of the target tumor and critical structures are then propagated from the planning CT to daily CBCTs using the computed deformations. The actual delivered daily dose is computed using the registered CT and patient setup information by a superposition/convolution algorithm, and accumulated using the computed deformation fields. Both DIR and dose computation modules are accelerated by a graphics processing unit. The cumulative dose computation process has been validated on 30 head and neck (HN) cancer cases, showing 3.5 ± 5.0 Gy (mean±STD) absolute mean dose differences between the planned and the actually delivered doses in the parotid glands. On average, DIR, dose computation, and segmentation take 20 s/fraction and 17 min for a 35-fraction treatment including additional computation for dose accumulation. The authors developed a unified software platform that provides accurate and efficient monitoring of

  15. Dose Assessments to the Hands of Radiopharmaceutical Workers

    SciTech Connect

    Ilas, Dan; Eckerman, Keith F; Sherbini, Sami; Karagiannis, Harriet

    2008-01-01

    This paper describes the characterization of radiation doses to the hands of nuclear medicine technicians resulting from the handling of radiopharmaceuticals. Radiation monitoring using ring dosimeters indicates that finger dosimeters may overestimate or underestimate the radiation doses to the skin that are used to show compliance with applicable regulations depending on the nature of the particular procedure and the radioisotope being handled. To better understand the parameters governing the absorbed dose distributions, a detailed model of the hands was created and used in Monte Carlo simulations of selected nuclear medicine procedures. Simulations on realistic configurations typical for workers handling radiopharmaceuticals were performed for a range of energies of the source photons. The lack of charged-particle equilibrium necessitated full photon-electron coupled transport calculations. The results show that the dose to different regions of the fingers can differ substantially from the dosimeters' readings when the dosimeters are located at the base of the finger. We tried to identify consistent patterns that relate the actual dose to the dosimeter readings. These patterns depend on the specific work conditions and can be used to better assess the absorbed dose to different regions of the exposed skin.

  16. TSD-DOSE: A radiological dose assessment model for treatment, storage, and disposal facilities

    SciTech Connect

    Pfingston, M.; Arnish, J.; LePoire, D.; Chen, S.-Y.

    1998-10-14

    Past practices at US Department of Energy (DOE) field facilities resulted in the presence of trace amounts of radioactive materials in some hazardous chemical wastes shipped from these facilities. In May 1991, the DOE Office of Waste Operations issued a nationwide moratorium on shipping all hazardous waste until procedures could be established to ensure that only nonradioactive hazardous waste would be shipped from DOE facilities to commercial treatment, storage, and disposal (TSD) facilities. To aid in assessing the potential impacts of shipments of mixed radioactive and chemically hazardous wastes, a radiological assessment computer model (or code) was developed on the basis of detailed assessments of potential radiological exposures and doses for eight commercial hazardous waste TSD facilities. The model, called TSD-DOSE, is designed to incorporate waste-specific and site-specific data to estimate potential radiological doses to on-site workers and the off-site public from waste-handling operations at a TSD facility. The code is intended to provide both DOE and commercial TSD facilities with a rapid and cost-effective method for assessing potential human radiation exposures from the processing of chemical wastes contaminated with trace amounts of radionuclides.

  17. 10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Conditions requiring individual monitoring of external and internal occupational dose. 20.1502 Section 20.1502 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Surveys and Monitoring § 20.1502 Conditions requiring individual monitoring of external and internal...

  18. INTERNAL DOSE AND RESPONSE IN REAL-TIME.

    EPA Science Inventory

    Abstract: Rapid temporal fluctuations in exposure may occur in a number of situations such as accidents or other unexpected acute releases of airborne substances. Often risk assessments overlook temporal exposure patterns under simplifying assumptions such as the use of time-wei...

  19. INTERNAL DOSE AND RESPONSE IN REAL-TIME.

    EPA Science Inventory

    Abstract: Rapid temporal fluctuations in exposure may occur in a number of situations such as accidents or other unexpected acute releases of airborne substances. Often risk assessments overlook temporal exposure patterns under simplifying assumptions such as the use of time-wei...

  20. Estimation of internal organ motion-induced variance in radiation dose in non-gated radiotherapy

    NASA Astrophysics Data System (ADS)

    Zhou, Sumin; Zhu, Xiaofeng; Zhang, Mutian; Zheng, Dandan; Lei, Yu; Li, Sicong; Bennion, Nathan; Verma, Vivek; Zhen, Weining; Enke, Charles

    2016-12-01

    In the delivery of non-gated radiotherapy (RT), owing to intra-fraction organ motion, a certain degree of RT dose uncertainty is present. Herein, we propose a novel mathematical algorithm to estimate the mean and variance of RT dose that is delivered without gating. These parameters are specific to individual internal organ motion, dependent on individual treatment plans, and relevant to the RT delivery process. This algorithm uses images from a patient’s 4D simulation study to model the actual patient internal organ motion during RT delivery. All necessary dose rate calculations are performed in fixed patient internal organ motion states. The analytical and deterministic formulae of mean and variance in dose from non-gated RT were derived directly via statistical averaging of the calculated dose rate over possible random internal organ motion initial phases, and did not require constructing relevant histograms. All results are expressed in dose rate Fourier transform coefficients for computational efficiency. Exact solutions are provided to simplified, yet still clinically relevant, cases. Results from a volumetric-modulated arc therapy (VMAT) patient case are also presented. The results obtained from our mathematical algorithm can aid clinical decisions by providing information regarding both mean and variance of radiation dose to non-gated patients prior to RT delivery.

  1. TSD-DOSE : a radiological dose assessment model for treatment, storage, and disposal facilities.

    SciTech Connect

    Pfingston, M.

    1998-12-23

    In May 1991, the U.S. Department of Energy (DOE), Office of Waste Operations, issued a nationwide moratorium on shipping slightly radioactive mixed waste from DOE facilities to commercial treatment, storage, and disposal (TSD) facilities. Studies were subsequently conducted to evaluate the radiological impacts associated with DOE's prior shipments through DOE's authorized release process under DOE Order 5400.5. To support this endeavor, a radiological assessment computer code--TSD-DOSE (Version 1.1)--was developed and issued by DOE in 1997. The code was developed on the basis of detailed radiological assessments performed for eight commercial hazardous waste TSD facilities. It was designed to utilize waste-specific and site-specific data to estimate potential radiological doses to on-site workers and the off-site public from waste handling operations at a TSD facility. The code has since been released for use by DOE field offices and was recently used by DOE to evaluate the release of septic waste containing residual radioactive material to a TSD facility licensed under the Resource Conservation and Recovery Act. Revisions to the code were initiated in 1997 to incorporate comments received from users and to increase TSD-DOSE's capability, accuracy, and flexibility. These updates included incorporation of the method used to estimate external radiation doses from DOE's RESRAD model and expansion of the source term to include 85 radionuclides. In addition, a detailed verification and benchmarking analysis was performed.

  2. Assessment of Organ Doses for a Glovebox Worker Using Realistic Postures with PIMAL and VOXMAT

    SciTech Connect

    Akkurt, Hatice; Bekar, Kursat; Eckerman, Keith F

    2009-01-01

    In an earlier effort, the Oak Ridge National Laboratory (ORNL) mathematical phantom has been revised to enable assessment of radiation dose for different postures in occupational exposures by enabling freely positioning arms and legs. The revised phantom is called PIMAL: Phantom wIth Moving Arms and Legs. Further, to assist the analyst with input preparation and output manipulation for different postures, a graphical user interface has been developed. Also, at ORNL a hybrid computational phantom, which uses a combination of voxelized and stylized geometry, for radiation dose assessment was recently developed. This phantom is based on the International Commission on Radiological Protection's (ICRP's) male phantom model and is called VOXMAT. For VOXMAT, the head and torso, which contain significant anatomical details, were described using voxel geometry. The arms and legs, which contain less-detailed anatomical structures, were modeled using the mathematical equations (stylized approach). With this approach the number of voxels was reduced from 7 million to 2.3 million, which translated into a proportional reduction in computational time and memory requirements. More importantly, VOXMAT allows easy the movement of arms and legs for radiation dose assessment for realistic postures. To determine/demonstrate the importance of the realistic posture for a case study, PIMAL and VOXMAT are applied to assess the dose to a glovebox worker. In this paper, the comparative computational results for the estimated dose are presented.

  3. AN APPROACH TO REDUCTION OF UNCERTAINTIES IN INTERNAL DOSES RECONSTRUCTED FOR THE TECHA RIVER POPULATION

    SciTech Connect

    Degteva, M. O.; Shagina, N. B.; Tolstykh, E. I.; Bougrov, N. G.; Zalyapin, V. I.; Anspaugh, L. R.; Napier, Bruce A.

    2007-12-01

    A methodology is being developing for reduction of uncertainties in estimates of internal dose for residents of the Techa Riverside communities, who were exposed as a result of releases of radionuclides from the Mayak plutonium-production facility in 1949–1956. The “Techa River Dosimetry System” (TRDS) was specifically elaborated for reconstruction of doses. A preliminary analysis of uncertainty for doses estimated using the current version of the TRDS showed large ranges in the uncertainty of internal absorbed dose and led to suggestions of methods to reduce uncertainties. The new methodological approaches described in this paper will allow for significant reduction of uncertainties of 90Sr-dose. The major sources of reduction are in making use of individual measured values of 90Sr and through development of a Household Registry to associate unmeasured persons with measured persons living in the same household(s).

  4. Dose estimation for internal organs during boron neutron capture therapy for body-trunk tumors.

    PubMed

    Sakurai, Y; Tanaka, H; Suzuki, M; Masunaga, S; Kinashi, Y; Kondo, N; Ono, K; Maruhashi, A

    2014-06-01

    Radiation doses during boron neutron capture therapy for body-trunk tumors were estimated for various internal organs, using data from patients treated at Kyoto University Research Reactor Institute. Dose-volume histograms were constructed for tissues of the lung, liver, kidney, pancreas, and bowel. For pleural mesothelioma, the target total dose to the normal lung tissues on the diseased side is 5Gy-Eq in average for the whole lung. It was confirmed that the dose to the liver should be carefully considered in cases of right lung disease. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Patient doses in {gamma}-intracoronary radiotherapy: The Radiation Burden Assessment Study

    SciTech Connect

    Thierens, Hubert . E-mail: hubert.thierens@Ughent.be; Reynaert, Nick; Bacher, Klaus; Eijkeren, Marc van; Taeymans, Yves

    2004-10-01

    Purpose: To determine accurately the radiation burden of both patients and staff from intracoronary radiotherapy (IRT) with {sup 192}Ir and to investigate the importance of IRT in the patient dose compared with interventional X-rays. Methods and materials: The Radiation Burden Assessment Study (RABAS) population consisted of 9 patients undergoing {gamma}-IRT after percutaneous transluminal coronary angioplasty and 14 patients undergoing percutaneous transluminal coronary angioplasty only as the control group. For each patient, the dose to the organs and tissues from the internal and external exposure was determined in detail by Monte Carlo N-particle simulations. Patient skin dose measurements with thermoluminescence dosimeters served as verification. Staff dosimetry was performed with electronic dosimeters, thermoluminescence dosimeters, and double film badge dosimetry. Results: With respect to the patient dose from IRT, the critical organs are the thymus (58 mGy), lungs (31 mGy), and esophagus (27 mGy). The mean effective dose from IRT was 8 mSv. The effective dose values from interventional X-rays showed a broad range (2-28 mSv), with mean values of 8 mSv for the IRT patients and 13 mSv for the control group. The mean dose received by the radiotherapist from IRT was 4 {mu}Sv/treatment. The doses to the other staff members were completely negligible. Conclusion: Our results have shown that the patient and personnel doses in {gamma}-IRT remain at an acceptable level. The patient dose from IRT was within the variations in dose from the accompanying interventional X-rays.

  6. Effects of body habitus on internal radiation dose calculations using the 5-year-old anthropomorphic male models

    NASA Astrophysics Data System (ADS)

    Xie, Tianwu; Kuster, Niels; Zaidi, Habib

    2017-08-01

    Computational phantoms are commonly used in internal radiation dosimetry to assess the amount and distribution pattern of energy deposited in various parts of the human body from different internal radiation sources. Radiation dose assessments are commonly performed on predetermined reference computational phantoms while the argument for individualized patient-specific radiation dosimetry exists. This study aims to evaluate the influence of body habitus on internal dosimetry and to quantify the uncertainties in dose estimation correlated with the use of fixed reference models. The 5-year-old IT’IS male phantom was modified to match target anthropometric parameters, including body weight, body height and sitting height/stature ratio (SSR), determined from reference databases, thus enabling the creation of 125 5-year-old habitus-dependent male phantoms with 10th, 25th, 50th, 75th and 90th percentile body morphometries. We evaluated the absorbed fractions and the mean absorbed dose to the target region per unit cumulative activity in the source region (S-values) of F-18 in 46 source regions for the generated 125 anthropomorphic 5-year-old hybrid male phantoms using the Monte Carlo N-Particle eXtended general purpose Monte Carlo transport code and calculated the absorbed dose and effective dose of five 18F-labelled radiotracers for children of various habitus. For most organs, the S-value of F-18 presents stronger statistical correlations with body weight, standing height and sitting height than BMI and SSR. The self-absorbed fraction and self-absorbed S-values of F-18 and the absorbed dose and effective dose of 18F-labelled radiotracers present with the strongest statistical correlations with body weight. For 18F-Amino acids, 18F-Brain receptor substances, 18F-FDG, 18F-L-DOPA and 18F-FBPA, the mean absolute effective dose differences between phantoms of different habitus and fixed reference models are 11.4%, 11.3%, 10.8%, 13.3% and 11.4%, respectively. Total body

  7. An internal radiation dosimetry computer program, IDAC 2.0, for estimation of patient doses from radiopharmaceuticals.

    PubMed

    Andersson, M; Johansson, L; Minarik, D; Mattsson, S; Leide-Svegborn, S

    2014-12-01

    The internal dosimetry computer program internal dose assessment by computer (IDAC) for calculations of absorbed doses to organs and tissues as well as effective doses to patients from examinations with radiopharmaceuticals has been developed. The new version, IDAC2.0, incorporates the International Commission on Radiation Protection (ICRP)/ICRU computational adult male and female voxel phantoms and decay data from the ICRP publication 107. Instead of only 25 source and target regions, calculation can now be made with 63 source regions to 73 target regions. The major advantage of having the new phantom is that the calculations of the effective doses can be made with the latest tissue weighting factors of ICRP publication 103. IDAC2.0 uses the ICRP human alimentary tract (HAT) model for orally administrated activity and for excretion through the gastrointestinal tract and effective doses have been recalculated for radiopharmaceuticals that are orally administered. The results of the program are consistent with published data using the same specific absorption fractions and also compared with published data from the same computational phantoms but with segmentation of organs leading to another set of specific absorption fractions. The effective dose is recalculated for all the 34 radiopharmaceuticals that are administered orally and has been published by the ICRP. Using the new HAT model, new tissue weighting factors and the new adult computational voxel phantoms lead to an average effective dose of half of its earlier estimated value. The reduction mainly depends on electron transport simulations to walled organs and the transition from the stylised phantom with unrealistic interorgan distances to more realistic voxel phantoms.

  8. Absorbed dose assessment in newborns during x-ray examinations

    NASA Astrophysics Data System (ADS)

    Taipe, Patricia K.; Berrocal, Mariella J.; Carita, Raúl F.

    2012-02-01

    Often a newborn presents breathing problems during the early days of life, i.e. bronchopneumonia, wich are caused in most of cases, by aspirating a mixture of meconium and amniotic fluid. In these cases, it is necessary to make use of a radiograph, requested by the physician to reach a diagnosis. This paper seeks to evaluate the absorbed doses in neonates undergoing a radiograph. For this reason we try to simulate the real conditions in a X-ray room from Lima hospitals. With this finality we perform a simulation made according a questionnaire related to technical data of X-ray equipment, distance between the source and the neonate, and its position to be irradiated. The information obtained has been used to determine the absorbed dose by infants, using the MCNP code. Finally, the results are compared with reference values of international health agencies.

  9. Fetal Assessment before and after Dosing with Buprenorphine or Methadone

    PubMed Central

    Salisbury, Amy L.; Coyle, Mara G.; O’Grady, Kevin E.; Heil, Sarah H.; Martin, Peter R.; Stine, Susan M.; Kaltenbach, Karol; Weninger, Manfred; Jones, Hendrée E.

    2014-01-01

    Aim To determine pre- and post-dosing effects of prenatal methadone compared to buprenorphine on fetal well-being. Design A secondary analysis of data derived from the Maternal Opioid Treatment: Human Experimental Research (MOTHER) study, a double-blind, double-dummy, randomized clinical trial. Setting Six United States sites and one European site that provided comprehensive opioid-dependence treatment to pregnant women. Participants 81 of the 131 opioid-dependent pregnant women completing the MOTHER clinical trial, assessed between 31 and 33 weeks of gestation. Measurements Two fetal assessments were conducted, once before and once after study medication dosing. Measures included mean fetal heart rate (FHR), number of FHR accelerations, FHR reactivity in the fetal non-stress test (NST), and biophysical profile (BPP) score. Findings Significant group differences were found for number of FHR accelerations, non-reactive NST, and BPP scores (all Ps < 0.05). There were no significant group differences before time of dosing. Significant decreases (all Ps < 0.05) occurred from pre- to post-dose assessment for mean FHR, FHR accelerations, reactive NST, and fetal movement. The decrease in accelerations and reactive NST were only significant for fetuses in the methadone group and this resulted in a significantly lower likelihood of a reactive NST compared to fetuses in the buprenorphine group. Conclusion Buprenorphine compared with methadone appears to result in less suppression of mean fetal heart rate, fetal heart rate reactivity, and the biophysical profile score after medication dosing and provide support for the relative safety of buprenorphine when fetal indices are considered as part of the complete risk-benefit ratio. PMID:23106925

  10. Fetal assessment before and after dosing with buprenorphine or methadone.

    PubMed

    Salisbury, Amy L; Coyle, Mara G; O'Grady, Kevin E; Heil, Sarah H; Martin, Peter R; Stine, Susan M; Kaltenbach, Karol; Weninger, Manfred; Jones, Hendrée E

    2012-11-01

    To determine pre- and post-dosing effects of prenatal methadone compared to buprenorphine on fetal wellbeing. A secondary analysis of data derived from the Maternal Opioid Treatment: Human Experimental Research (MOTHER) study, a double-blind, double-dummy, randomized clinical trial. Six United States sites and one European site that provided comprehensive opioid-dependence treatment to pregnant women. Eighty-one of the 131 opioid-dependent pregnant women completing the MOTHER clinical trial, assessed between 31 and 33 weeks of gestation. Two fetal assessments were conducted, once before and once after study medication dosing. Measures included mean fetal heart rate (FHR), number of FHR accelerations, FHR reactivity in the fetal non-stress test (NST) and biophysical profile (BPP) score. Significant group differences were found for number of FHR accelerations, non-reactive NST and BPP scores (all Ps < 0.05). There were no significant group differences before time of dosing. Significant decreases (all Ps < 0.05) occurred from pre- to post-dose assessment for mean FHR, FHR accelerations, reactive NST and fetal movement. The decrease in accelerations and reactive NST were significant only for fetuses in the methadone group, and this resulted in a significantly lower likelihood of a reactive NST compared to fetuses in the buprenorphine group. Buprenorphine compared with methadone appears to result in less suppression of mean fetal heart rate, fetal heart rate reactivity and the biophysical profile score after medication dosing and these findings provide support for the relative safety of buprenorphine when fetal indices are considered as part of the complete risk-benefit ratio. © 2012 The Authors, Addiction © 2012 Society for the Study of Addiction.

  11. Assessment of patient dose in medical processes by in-vivo dose measuring devices: A review

    NASA Astrophysics Data System (ADS)

    Tuncel, Nina

    2016-11-01

    In-vivo dosimetry (IVD) in medicine especially in radiation therapy is a well-established and recommended procedure for the estimation of the dose delivered to a patient during the radiation treatment. It became even more important with the emerging use of new and more complex radiotherapy techniques such as intensity-modulated or image-guided radiation therapy. While IVD has been used in brachytherapy for decades and the initial motivation for performing was mainly to assess doses to organs at risk by direct measurements, it is now possible to calculate 3D for detection of deviations or errors. In-vivo dosimeters can be divided into real-time and passive detectors that need some finite time following irradiation for their analysis. They require a calibration against a calibrated ionization chamber in a known radiation field. Most of these detectors have a response that is energy and/or dose rate dependent and consequently require adjustments of the response to account for changes in the actual radiation conditions compared to the calibration situation. Correction factors are therefore necessary to take. Today, the most common dosimeters for patients' dose verification through in-vivo measurements are semiconductor diodes, thermo-luminescent dosimeters, optically stimulated luminescence dosimeters, metal-oxide-semiconductor field-effect transistors and plastic scintillator detectors with small outer diameters.

  12. Intraoperative fluoroscopic dose assessment in prostate brachytherapy patients.

    PubMed

    Reed, Daniel R; Wallner, Kent E; Narayanan, Sreeram; Sutlief, Steve G; Ford, Eric C; Cho, Paul S

    2005-09-01

    To evaluate a fluoroscopy-based intraoperative dosimetry system to guide placement of additional sources to underdosed areas, and perform computed tomography (CT) verification. Twenty-six patients with prostate carcinoma treated with either I-125 or Pd-103 brachytherapy at the Puget Sound VA using intraoperative postimplant dosimetry were analyzed. Implants were performed by standard techniques. After completion of the initial planned brachytherapy procedure, the initial fluoroscopic intraoperative dose reconstruction analysis (I-FL) was performed with three fluoroscopic images acquired at 0 (AP), +15, and -15 degrees. Automatic seed identification was performed and the three-dimensional (3D) seed coordinates were computed and imported into VariSeed for dose visualization. Based on a 3D assessment of the isodose patterns additional seeds were implanted, and the final fluoroscopic intraoperative dose reconstruction was performed (FL). A postimplant computed tomography (CT) scan was obtained after the procedure and dosimetric parameters and isodose patterns were analyzed and compared. An average of 4.7 additional seeds were implanted after intraoperative analysis of the dose coverage (I-FL), and a median of 5 seeds. After implantation of additional seeds the mean V100 increased from 89% (I-FL) to 92% (FL) (p < 0.001). In I-125 patients an improvement from 91% to 94% (p = 0.01), and 87% to 93% (p = 0.001) was seen for Pd-103. The D90 increased from 105% (I-FL) to 122% (FL) (p < 0.001) for I-125, and 92% (I-FL) to 102% (FL) (p = 0.008) for Pd-103. A minimal change occurred in the R100 from a mean of 0.32 mL (I-FL) to 0.6 mL (FL) (p = 0.19). No statistical difference was noted in the R100 (rectal volume receiving 100% of the prescribed dose) between the two techniques. The rate of adverse isodose patterns decreased between I-FL and FL from 42% to 8%, respectively. The I-125 patients demonstrated a complete resolution of adverse isodose patterns after the initial isodose

  13. Radiological environmental dose assessment methods and compliance dose results for 2015 operations at the Savannah River Site

    SciTech Connect

    Jannik, G. T.; Dixon, K. L.

    2016-09-01

    This report presents the environmental dose assessment methods and the estimated potential doses to the offsite public from 2015 Savannah River Site (SRS) atmospheric and liquid radioactive releases. Also documented are potential doses from special-case exposure scenarios - such as the consumption of deer meat, fish, and goat milk.

  14. Cone beam computed tomography radiation dose and image quality assessments.

    PubMed

    Lofthag-Hansen, Sara

    2010-01-01

    Diagnostic radiology has undergone profound changes in the last 30 years. New technologies are available to the dental field, cone beam computed tomography (CBCT) as one of the most important. CBCT is a catch-all term for a technology comprising a variety of machines differing in many respects: patient positioning, volume size (FOV), radiation quality, image capturing and reconstruction, image resolution and radiation dose. When new technology is introduced one must make sure that diagnostic accuracy is better or at least as good as the one it can be expected to replace. The CBCT brand tested was two versions of Accuitomo (Morita, Japan): 3D Accuitomo with an image intensifier as detector, FOV 3 cm x 4 cm and 3D Accuitomo FPD with a flat panel detector, FOVs 4 cm x 4 cm and 6 cm x 6 cm. The 3D Accuitomo was compared with intra-oral radiography for endodontic diagnosis in 35 patients with 46 teeth analyzed, of which 41 were endodontically treated. Three observers assessed the images by consensus. The result showed that CBCT imaging was superior with a higher number of teeth diagnosed with periapical lesions (42 vs 32 teeth). When evaluating 3D Accuitomo examinations in the posterior mandible in 30 patients, visibility of marginal bone crest and mandibular canal, important anatomic structures for implant planning, was high with good observer agreement among seven observers. Radiographic techniques have to be evaluated concerning radiation dose, which requires well-defined and easy-to-use methods. Two methods: CT dose index (CTDI), prevailing method for CT units, and dose-area product (DAP) were evaluated for calculating effective dose (E) for both units. An asymmetric dose distribution was revealed when a clinical situation was simulated. Hence, the CTDI method was not applicable for these units with small FOVs. Based on DAP values from 90 patient examinations effective dose was estimated for three diagnostic tasks: implant planning in posterior mandible and

  15. Dose assessment during complex meteorology in the Texas panhandle

    SciTech Connect

    Schalk, W.W. III; Foster, K.

    1989-06-01

    Recently the opportunity arose to perform a radiological assessment during complex meteorological conditions in the panhandle region of Texas. The complex conditions consisted of the formation of an occluded front from a trof and its passage from the southwest, a southwest to northeast trof formation northwest of the assessment point, an area of low pressure centered to the west, and severe thunderstorms at the assessment time at and near the study region while under watch box notification. Most of these features can be seen on the 17 May 89 surface analysis. The assessment included a normalized release rate of tritiated water vapor in which the 50 year committed effective whole body integrated air dose plots were compared over time. 2 refs., 2 figs.

  16. Assessment of organ absorbed doses and estimation of effective doses from pediatric anthropomorphic phantom measurements for multi-detector row CT with and without automatic exposure control.

    PubMed

    Brisse, Hervé J; Robilliard, Magalie; Savignoni, Alexia; Pierrat, Noelle; Gaboriaud, Geneviève; De Rycke, Yann; Neuenschwander, Sylvia; Aubert, Bernard; Rosenwald, Jean-Claude

    2009-10-01

    This study was designed to measure organ absorbed doses from multi-detector row computed tomography (MDCT) on pediatric anthropomorphic phantoms, calculate the corresponding effective doses, and assess the influence of automatic exposure control (AEC) in terms of organ dose variations. Four anthropomorphic phantoms (phantoms represent the equivalent of a newborn, 1-, 5-, and 10-y-old child) were scanned with a four-channel MDCT coupled with a z-axis-based AEC system. Two CT torso protocols were compared: a first protocol without AEC and constant tube current-time product and a second protocol with AEC using age-adjusted noise indices. Organ absorbed doses were monitored by thermoluminescent dosimeters (LiF: Mg, Cu, P). Effective doses were calculated according to the tissue weighting factors of the International Commission on Radiological Protection (). For fixed mA acquisitions, organ doses normalized to the volume CT dose index in a 16-cm head phantom (CTDIvol16) ranged from 0.6 to 1.5 and effective doses ranged from 8.4 to 13.5 mSv. For the newborn-equivalent phantom, the AEC-modulated scan showed almost no significant dose variation compared to the fixed mA scan. For the 1-, 5- and 10-y equivalent phantoms, the use of AEC induced a significant dose decrease on chest organs (ranging from 61 to 31% for thyroid, 37 to 21% for lung, 34 to 17% for esophagus, and 39 to 10% for breast). However, AEC also induced a significant dose increase (ranging from 28 to 48% for salivary glands, 22 to 51% for bladder, and 24 to 70% for ovaries) related to the high density of skull base and pelvic bones. These dose increases should be considered before using AEC as a dose optimization tool in children.

  17. Dose limits to the lens of the eye: International Basic Safety Standards and related guidance.

    PubMed

    Boal, T J; Pinak, M

    2015-06-01

    The International Atomic Energy Agency (IAEA) safety requirements: 'General Safety Requirements Part 3--Radiation protection and safety of radiation sources: International Basic Safety Standards' (BSS) was approved by the IAEA Board of Governors at its meeting in September 2011, and was issued as General Safety Requirements Part 3 in July 2014. The equivalent dose limit for the lens of the eye for occupational exposure in planned exposure situations was reduced from 150 mSv year(-1) to 20 mSv year(-1), averaged over defined periods of 5 years, with no annual dose in a single year exceeding 50 mSv. This reduction in the dose limit for the lens of the eye followed the recommendation of the International Commission on Radiological Protection in its statement on tissue reactions of 21 April 2011. IAEA has developed guidance on the implications of the new dose limit for the lens of the eye. This paper summarises the process that led to the inclusion of the new dose limit for the lens of the eye in the BSS, and the implications of the new dose limit.

  18. Radon dose assessment in underground mines in Brazil.

    PubMed

    Santos, T O; Rocha, Z; Cruz, P; Gouvea, V A; Siqueira, J B; Oliveira, A H

    2014-07-01

    Underground miners are internally exposed to radon, thoron and their short-lived decay products during the mineral processing. There is also an external exposure due to the gamma emitters present in the rock and dust of the mine. However, the short-lived radon decay products are recognised as the main radiation health risk. When inhaled, they are deposited in the respiratory system and may cause lung cancer. To address this concern, concentration measurements of radon and its progeny were performed, the equilibrium factor was determined and the effective dose received was estimated in six Brazilian underground mines. The radon concentration was measured by using E-PERM, AlphaGUARD and CR-39 detectors. The radon progeny was determined by using DOSEman. The annual effective dose for the miners was estimated according to United Nations Scientific Committee on the Effects of Atomic Radiation methodologies. The mean value of the equilibrium factor was 0.4. The workers' estimated effective dose ranged from 1 to 21 mSv a(-1) (mean 9 mSv a(-1)). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. TRIAGE DOSE ASSESSMENT FOR PARTIAL-BODY EXPOSURE: DICENTRIC ANALYSIS

    PubMed Central

    Moroni, Maria; Pellmar, Terry C.

    2009-01-01

    Partial-body biodosimetry is likely to be required after a radiological or nuclear exposure. Clinical signs and symptoms, distribution of dicentrics in circulating blood cells, organ-specific biomarkers, physical signals in teeth and nails all can provide indications of non-homogeneous exposures. Organ specific biomarkers may provide early warning regarding physiological systems at risk after radiation injury. Use of a combination of markers and symptoms will be needed for clinical insights for therapeutic approaches. Analysis of dicentrics, a marker specific for radiation injury, is the “Gold standard” of biodosimetry and can reveal partial-body exposures. Automation of sample processing for dicentric analysis can increase throughput with customization of off-the-shelf technologies for cytogenetic sample processing and information management. Automated analysis of the metaphase spreads is currently limited but improvements are in development. Our efforts bridge the technological gaps to allow the use of dicentric chromosome assay (DCA) for risk-based stratification of mass casualties. This article summarizes current knowledge on partial-body cytogenetic dose assessment synthesizing information leading to the proposal of an approach to triage dose prediction in radiation mass casualties, based on equivalent whole-body doses under partial-body exposure conditions and assesses the validity of using this model. An initial screening using only 20 metaphase spreads per subject can confirm irradiation above 2-Gy. A subsequent increase to 50 metaphases improves dose determination to allow risk stratification for clinical triage. Metaphases evaluated for inhomogeneous distribution of dicentrics can reveal partial-body exposures. We tested the validity of this approach in an in vitro model that simulates partial-body irradiation by mixing irradiated and un-irradiated lymphocytes in various proportions. Our preliminary results support the notion that this approach will

  20. Habitability Assessment of International Space Station

    NASA Technical Reports Server (NTRS)

    Thaxton, Sherry

    2015-01-01

    The purpose of this study is to assess habitability during the International Space Station 1-year mission, and subsequent 6-month missions, in order to better prepare for future long-duration spaceflights to destinations such as Near Earth Asteroid (NEA) and Mars, which will require crewmembers to live and work in a confined spacecraft environment for over a year. Data collected using Space Habitability Observation Reporting Tool (iSHORT), crew-collected videos, questionnaires, and PI conferences will help characterize the current state of habitability for the ISS. These naturalistic techniques provide crewmembers with the opportunity to self-report habitability and human factors observations in near real-time, which is not systematically done during ISS missions at present.

  1. Source term calculations for assessing radiation dose to equipment

    SciTech Connect

    Denning, R.S.; Freeman-Kelly, R.; Cybulskis, P.; Curtis, L.A.

    1989-07-01

    This study examines results of analyses performed with the Source Term Code Package to develop updated source terms using NUREG-0956 methods. The updated source terms are to be used to assess the adequacy of current regulatory source terms used as the basis for equipment qualification. Time-dependent locational distributions of radionuclides within a containment following a severe accident have been developed. The Surry reactor has been selected in this study as representative of PWR containment designs. Similarly, the Peach Bottom reactor has been used to examine radionuclide distributions in boiling water reactors. The time-dependent inventory of each key radionuclide is provided in terms of its activity in curies. The data are to be used by Sandia National Laboratories to perform shielding analyses to estimate radiation dose to equipment in each containment design. See NUREG/CR-5175, Beta and Gamma Dose Calculations for PWR and BWR Containments.'' 6 refs., 11 tabs.

  2. ARAC: A flexible real-time dose consequence assessment system

    SciTech Connect

    Ellis, J.S.; Sullivan, T.J.

    1993-10-07

    Since its beginning, the Atmospheric Release Advisory Capability (ARAC), an emergency radiological dose assessment service of the US Government, has been called on to do consequence assessments for releases into the atmosphere of radionuclides and a variety of other substances. Some of the more noteworthy emergency responses have been for the Three Mile Island and Chernobyl nuclear power reactor accidents, and more recently, for a cloud of gases from a rail-car spill into the Sacramento river of the herbicide metam sodium, smoke from hundreds of burning oil wells in Kuwait, and ash clouds from the eruption of Mt. Pinatubo. The spatial scales of these responses range from local, to regional, to global, and the response periods from hours, to weeks, to months. Because of the variety of requirements of each unique assessment, ARAC has developed and maintains a flexible system of people, computer software and hardware.

  3. Why a Global International Waters Assessment (GIWA)?

    PubMed

    Hempel, Gotthilf; Daler, Dag

    2004-02-01

    Why GIWA? Six years ago several people had their doubts as to whether a Global International Waters Assessment would be worth the money and effort. Nowadays, it is no longer necessary to justify the creation of GIWA. On the contrary, we will show how important it was that the Global Environmental Facility (GEF) and UNEP, constituted GIWA. Countless water-related assessments focus on specific regions and/or specific issues. But GIWA is unique in its global and holistic policy-oriented approach applying a common methodology to address the major problems in all parts of the global hydrosphere. One major achievement of GIWA will be the GIWA publications which provide advice to GEF and other decision-making organizations. Further assets include the network of regional focal points and teams. GIWA encompasses marine, surface freshwater, and groundwater systems, following the flow of water from the sources in the mountains through the rivers and estuaries into the coastal waters and the shelf seas. GIWA studies the physical, chemical and biological properties of those waterbodies and living resources in relation to the human activities, combining ecological and socioeconomic considerations.

  4. Upper-Bound Radiation Dose Assessment for Military Personnel at McMurdo Station, Antarctica, between 1962 and 1979

    DTIC Science & Technology

    2013-06-01

    radiation doses U.S. DoD-affiliated persons present in Japan following the nuclear reactor accident . Prior to working on the NTPR program, Dr. Chehata’s...Reconstruction (VBDR) to assess these risks . A DoD integrated program team was formed of military, civilian, and contract radiation health experts from the...possible health risk from exposure to radiation. The total equivalent dose to 3 the thyroid gland is from external and internal radiation sources and is

  5. Mixed species radioiodine air sampling readout and dose assessment system

    DOEpatents

    Distenfeld, Carl H.; Klemish, Jr., Joseph R.

    1978-01-01

    This invention provides a simple, reliable, inexpensive and portable means and method for determining the thyroid dose rate of mixed airborne species of solid and gaseous radioiodine without requiring highly skilled personnel, such as health physicists or electronics technicians. To this end, this invention provides a means and method for sampling a gas from a source of a mixed species of solid and gaseous radioiodine for collection of the mixed species and readout and assessment of the emissions therefrom by cylindrically, concentrically and annularly molding the respective species around a cylindrical passage for receiving a conventional probe-type Geiger-Mueller radiation detector.

  6. RADAR realistic animal model series for dose assessment.

    PubMed

    Keenan, Mary A; Stabin, Michael G; Segars, William P; Fernald, Michael J

    2010-03-01

    Rodent species are widely used in the testing and approval of new radiopharmaceuticals, necessitating murine phantom models. As more therapy applications are being tested in animal models, calculating accurate dose estimates for the animals themselves becomes important to explain and control potential radiation toxicity or treatment efficacy. Historically, stylized and mathematically based models have been used for establishing doses to small animals. Recently, a series of anatomically realistic human phantoms was developed using body models based on nonuniform rational B-spline. Realistic digital mouse whole-body (MOBY) and rat whole-body (ROBY) phantoms were developed on the basis of the same NURBS technology and were used in this study to facilitate dose calculations in various species of rodents. Voxel-based versions of scaled MOBY and ROBY models were used with the Vanderbilt multinode computing network (Advanced Computing Center for Research and Education), using geometry and tracking radiation transport codes to calculate specific absorbed fractions (SAFs) with internal photon and electron sources. Photon and electron SAFs were then calculated for relevant organs in all models. The SAF results were compared with values from similar studies found in reference literature. Also, the SAFs were used with standardized decay data to develop dose factors to be used in radiation dose calculations. Representative plots were made of photon electron SAFs, evaluating the traditional assumption that all electron energy is absorbed in the source organs. The organ masses in the MOBY and ROBY models are in reasonable agreement with models presented by other investigators noting that considerable variation can occur between reported masses. Results consistent with those found by other investigators show that absorbed fractions for electrons for organ self-irradiation were significantly less than 1.0 at energies above 0.5 MeV, as expected for many of these small-sized organs

  7. International exchange of emergency phase information and assessments: an aid to national/international decision makers.

    PubMed

    Sullivan, Thomas J; Chino, Masamichi; Ehrhardt, Joachim; Shershakov, Vyacheslav

    2004-01-01

    This paper discusses a collaborative project (1) to demonstrate the feasibility and benefit of a system seeking early review, in a 'quasi peer review' mode, of nuclear accident plume and dose assessment predictions by four major international nuclear accident emergency response systems before release of calculations to respective national authorities followed by (2) sharing these results with responsible national/international authorities, (3) development of an affordable/accessible system to distribute results to countries without prediction capabilities and (4) utilisation for exercises and collaboration studies. The project exploits Internet browser technology and low-cost PC hardware, incorporates an Internet node, with access control, for depositing a minimal set of XML-based graphics files for presentation in an identical map format. Side-by-side viewing and televideo conferencing will permit rapid evaluation, data elaboration and recalculation (if necessary) and should produce strong consensus among decision makers. Successful completion affords easy utilisation by national/international organisations and non-nuclear states at risk of trans-boundary incursion.

  8. A comprehensive dose reconstruction methodology for former rocketdyne/atomics international radiation workers.

    PubMed

    Boice, John D; Leggett, Richard W; Ellis, Elizabeth Dupree; Wallace, Phillip W; Mumma, Michael; Cohen, Sarah S; Brill, A Bertrand; Chadda, Bandana; Boecker, Bruce B; Yoder, R Craig; Eckerman, Keith F

    2006-05-01

    Incomplete radiation exposure histories, inadequate treatment of internally deposited radionuclides, and failure to account for neutron exposures can be important uncertainties in epidemiologic studies of radiation workers. Organ-specific doses from lifetime occupational exposures and radionuclide intakes were estimated for an epidemiologic study of 5,801 Rocketdyne/Atomics International (AI) radiation workers engaged in nuclear technologies between 1948 and 1999. The entire workforce of 46,970 Rocketdyne/AI employees was identified from 35,042 Kardex work histories cards, 26,136 electronic personnel listings, and 14,189 radiation folders containing individual exposure histories. To obtain prior and subsequent occupational exposure information, the roster of all workers was matched against nationwide dosimetry files from the Department of Energy, the Nuclear Regulatory Commission, the Landauer dosimetry company, the U.S. Army, and the U.S. Air Force. Dosimetry files of other worker studies were also accessed. Computation of organ doses from radionuclide intakes was complicated by the diversity of bioassay data collected over a 40-y period (urine and fecal samples, lung counts, whole-body counts, nasal smears, and wound and incident reports) and the variety of radionuclides with documented intake including isotopes of uranium, plutonium, americium, calcium, cesium, cerium, zirconium, thorium, polonium, promethium, iodine, zinc, strontium, and hydrogen (tritium). Over 30,000 individual bioassay measurements, recorded on 11 different bioassay forms, were abstracted. The bioassay data were evaluated using ICRP biokinetic models recommended in current or upcoming ICRP documents (modified for one inhaled material to reflect site-specific information) to estimate annual doses for 16 organs or tissues taking into account time of exposure, type of radionuclide, and excretion patterns. Detailed internal exposure scenarios were developed and annual internal doses were derived

  9. Assessment of the occupational eye lens dose for clinical staff in interventional radiology, cardiology and neuroradiology.

    PubMed

    Omar, Artur; Kadesjö, Nils; Palmgren, Charlotta; Marteinsdottir, Maria; Segerdahl, Tony; Fransson, Annette

    2017-03-20

    In accordance with recommendations by the International Commission on Radiological Protection, the current European Basic Safety Standards has adopted a reduced occupational eye lens dose limit of 20 mSv yr(-1). The radiation safety implications of this dose limit is of concern for clinical staff that work with relatively high dose x-ray angiography and interventional radiology. Presented in this work is a thorough assessment of the occupational eye lens dose based on clinical measurements with active personal dosimeters worn by staff during various types of procedures in interventional radiology, cardiology and neuroradiology. Results are presented in terms of the estimated equivalent eye lens dose for various medical professions. In order to compare the risk of exceeding the regulatory annual eye lens dose limit for the widely different clinical situations investigated in this work, the different medical professions were separated into categories based on their distinct work pattern: staff that work (a) regularly beside the patient, (b) in proximity to the patient and (c) typically at a distance from the patient. The results demonstrate that the risk of exceeding the annual eye lens dose limit is of concern for staff category (a), i.e. mainly the primary radiologist/cardiologist. However, the results also demonstrate that the risk can be greatly mitigated if radiation protection shields are used in the clinical routine. The results presented in this work cover a wide range of clinical situations, and can be used as a first indication of the risk of exceeding the annual eye lens dose limit for staff at other medical centres.

  10. International harmonization for the risk assessment of pesticides: results of an IPCS survey.

    PubMed

    Dragula, C; Burin, G

    1994-12-01

    Risk assessment harmonization has become an important issue on the environmental agendas of numerous countries. The benefits of an international consensus on risk assessment methodologies include decreased duplication of toxicity testing through the sharing of experimental data, decreased barriers to trade, and more consistency and cooperation within the scientific community. This paper presents the findings of an international survey of regulatory scientists in OECD and select non-OECD countries. The survey was sponsored by the International Programme on Chemical Safety (IPCS), which itself was formed by a cooperative agreement between the World Health Organization, the International Labor Organization, and the United Nations Environment Program. The survey results represent the first step in a project initiated by the IPCS to harmonize risk assessment methodologies used worldwide for the toxicological evaluation of chemicals. In this phase, the primary focus was on the health risk assessment of pesticides. Participants responded to questions regarding: (1) the support or review documents relied on for performing risk assessments; (2) procedures used and criteria applied when evaluating carcinogenicity data, including issues relating to mechanism of action, the maximum tolerated dose, and doses used in carcinogenicity bioassays; (3) risk assessment methodologies, such as the use no effect levels with safety factors or risk assessment models; (4) methods for assessing occupational and dietary exposure to pesticides; and (5) the primary areas of interest for the commencement of international harmonization efforts. There was significant consensus on specific issues relating to risk assessment methods and carcinogenicity assessment, as well as strong positive support for international harmonization activities. Differences existed with respect to the doses used in bioassays and data interpretation.

  11. Evaluation of the Emergency Response Dose Assessment System(ERDAS)

    NASA Technical Reports Server (NTRS)

    Evans, Randolph J.; Lambert, Winifred C.; Manobianco, John T.; Taylor, Gregory E.; Wheeler, Mark M.; Yersavich, Ann M.

    1996-01-01

    The emergency response dose assessment system (ERDAS) is a protype software and hardware system configured to produce routine mesoscale meteorological forecasts and enhanced dispersion estimates on an operational basis for the Kennedy Space Center (KSC)/Cape Canaveral Air Station (CCAS) region. ERDAS provides emergency response guidance to operations at KSC/CCAS in the case of an accidental hazardous material release or an aborted vehicle launch. This report describes the evaluation of ERDAS including: evaluation of sea breeze predictions, comparison of launch plume location and concentration predictions, case study of a toxic release, evaluation of model sensitivity to varying input parameters, evaluation of the user interface, assessment of ERDA's operational capabilities, and a comparison of ERDAS models to the ocean breeze dry gultch diffusion model.

  12. The immune tolerance induction (ITI) dose debate: does the International ITI Study provide a clearer picture?

    PubMed

    Ettingshausen, C Escuriola; Kreuz, W

    2013-01-01

    Among the proposed predictors for immune tolerance induction (ITI) outcome, the therapeutic regimen - specifically the dose and frequency of administered factor VIII (FVIII) as well as FVIII product type - is intensely debated. Are there any advantages for low-dose regimens (50 IU FVIII kg(-1) three times a week) over high-dose regimens (200 IU FVIII kg day(-1)) or vice versa? Are von Willebrand factor (VWF)-containing plasma-derived concentrates superior to recombinant FVIII concentrates for tolerance induction? A review of the available literature indicates that patients with good prognostic factors can achieve success with either low-dose or high-dose ITI regimens. Retrospective data suggest that patient characteristics such as maximum historical inhibitor titres and pre-ITI inhibitor titres are better predictors of treatment success than dose. Results of the prospective International ITI Study have recently become available. In inhibitor patients with good prognosis, success rates were similar between low-dose (50 IU FVIII kg(-1) three times a week) and high-dose (200 IU FVIII kg(-1) daily) regimens. However, patients receiving low-dose ITI took longer to achieve various ITI milestones and had a significantly higher bleed rate per month compared with the high-dose group (0.62 vs. 0.28; P = 0.00024), findings with important clinical implications. Inhibitor patients with poor prognostic features should be treated with a high-dose protocol. This conclusion is supported by a meta-analysis of the International Immune Tolerance Registry and North American Immune Tolerance Registry and by data from Germany showing good success rates with the high-dose, high-frequency Bonn protocol in poor prognosis patients. Type of concentrate also appears to have an influence on ITI success rates in this patient subgroup, with evidence suggesting an advantage for VWF-containing plasma-derived FVIII concentrates over recombinant or VWF-free concentrates. The ongoing prospective

  13. Environmental impact assessment: An international evaluation

    NASA Astrophysics Data System (ADS)

    Hollick, Malcolm

    1986-03-01

    Experiences with environmental impact assessment (EIA) in a number of countries are discussed in the light of both explicit and implicit goals and objectives. Adequate environmental information is not always available to decision makers because of failure to apply EIA to all relevant decisions, the continuing inadequacies of prediction and evaluation techniques, the failure to consider alternatives adequately, and the bias of some EISs. EIA frequently results in changes to proposals and may result in stricter environmental management conditions in some cases, but some people regard it as a failure because it has not stopped development. Generally, EIA leads to better integration of environmental factors into project planning. Open procedures and freedom of information encourage responsiveness to EIA procedures, which can be weakened by discretionary powers and lack of access to the courts by public interest groups. However, legal standing may have side effects that offset its advantages. EIA can encourage cooperation and coordination between agencies but does not ensure them. Similarly, it can have a limited role in coordinating interstate and international policies. In the long term, the success of EIA depends on adequate monitoring, reassessment, and enforcement over the life of the project. EIA has generally opened up new opportunities for public participation, and may help to reduce conflict. EIA procedures need to be integrated with other environmental protection and development control programs, and various means exist for reducing its cost to developers and the public.

  14. International Developments in Environmental and Social Impact Assessment

    EPA Science Inventory

    The author has been involved in international developments in comprehensive impact assessment since 1995. During that time she has participated in ISO 14040 series development, initiated and co-chaired three international workshops, participated in Society of Environmental Toxic...

  15. International Developments in Environmental and Social Impact Assessment

    EPA Science Inventory

    The author has been involved in international developments in comprehensive impact assessment since 1995. During that time she has participated in ISO 14040 series development, initiated and co-chaired three international workshops, participated in Society of Environmental Toxic...

  16. INTDOS: a computer code for estimating internal radiation dose using recommendations of the International Commission on Radiological Protection

    SciTech Connect

    Ryan, M.T.

    1981-09-01

    INTDOS is a user-oriented computer code designed to calculate estimates of internal radiation dose commitment resulting from the acute inhalation intake of various radionuclides. It is designed so that users unfamiliar with the details of such can obtain results by answering a few questions regarding the exposure case. The user must identify the radionuclide name, solubility class, particle size, time since exposure, and the measured lung burden. INTDOS calculates the fractions of the lung burden remaining at time, t, postexposure considering the solubility class and particle size information. From the fraction remaining in the lung at time, t, the quantity inhaled is estimated. Radioactive decay is accounted for in the estimate. Finally, effective committed dose equivalents to various organs and tissues of the body are calculated using inhalation committed dose factors presented by the International Commission on Radiological Protection (ICRP). This computer code was written for execution on a Digital Equipment Corporation PDP-10 computer and is written in Fortran IV. A flow chart and example calculations are discussed in detail to aid the user who is unfamiliar with computer operations.

  17. Assessing the effect of electron density in photon dose calculations

    SciTech Connect

    Seco, J.; Evans, P. M.

    2006-02-15

    Photon dose calculation algorithms (such as the pencil beam and collapsed cone, CC) model the attenuation of a primary photon beam in media other than water, by using pathlength scaling based on the relative mass density of the media to water. In this study, we assess if differences in the electron density between the water and media, with different atomic composition, can influence the accuracy of conventional photon dose calculations algorithms. A comparison is performed between an electron-density scaling method and the standard mass-density scaling method for (i) tissues present in the human body (such as bone, muscle, etc.), and for (ii) water-equivalent plastics, used in radiotherapy dosimetry and quality assurance. We demonstrate that the important material property that should be taken into account by photon dose algorithms is the electron density, and not the mass density. The mass-density scaling method is shown to overestimate, relative to electron-density predictions, the primary photon fluence for tissues in the human body and water-equivalent plastics, where 6%-7% and 10% differences were observed respectively for bone and air. However, in the case of patients, differences are expected to be smaller due to the large complexity of a treatment plan and of the patient anatomy and atomic composition and of the smaller thickness of bone/air that incident photon beams of a treatment plan may have to traverse. Differences have also been observed for conventional dose algorithms, such as CC, where an overestimate of the lung dose occurs, when irradiating lung tumors. The incorrect lung dose can be attributed to the incorrect modeling of the photon beam attenuation through the rib cage (thickness of 2-3 cm in bone upstream of the lung tumor) and through the lung and the oversimplified modeling of electron transport in convolution algorithms. In the present study, the overestimation of the primary photon fluence, using the mass-density scaling method, was shown

  18. 78 FR 14912 - International Aviation Safety Assessment (IASA) Program Change

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-08

    ... Federal Aviation Administration 14 CFR Part 129 International Aviation Safety Assessment (IASA) Program... statement describes a policy change to the FAA's International Aviation Safety Assessment (IASA) program... appropriate IASA category rating for a country using information collected during an in-country assessment of...

  19. Technical Basis for Expedited Processing of Radiation Dose Assessments for NTPR Hiroshima and Nagasaki Participants

    DTIC Science & Technology

    2015-11-01

    expedited processing of Radiation Dose Assessments (RDAs) for Hiroshima and Nagasaki (H&N) veterans in the Nuclear Test Personnel Review (NTPR) Program...Expedited processing of Nuclear Test Personnel Review program radiation dose assessments (RDAs) is an option for certain claims from the Department...Agency), 2015a. Expedited Processing of Radiation Dose Assessments for Atmospheric Nuclear Weapons Testing Veterans, NTPR Standard Operating

  20. Pharmacokinetic/Pharmacodynamic Modelling of Receptor Internalization with CRTH2 Antagonists to Optimize Dose Selection.

    PubMed

    Krause, Andreas; Zisowsky, Jochen; Strasser, Daniel S; Gehin, Martine; Sidharta, Patricia N; Groenen, Peter M A; Dingemanse, Jasper

    2016-07-01

    The chemoattractant receptor-homologous molecule expressed on T helper-2 cells (CRTH2) is a G-protein-coupled receptor for prostaglandin D2 (PGD2), a key mediator in inflammatory disorders. Two selective and potent CRTH2 antagonists currently in clinical development, ACT-453859 and setipiprant, were compared with respect to their (predicted) clinical efficacy. Population pharmacokinetic (PK) and pharmacodynamic (PD) models were developed to characterize how plasma concentrations (PK) of ACT-453859, its active metabolite ACT-463036 and setipiprant related to their effect on blocking PGD2-induced internalization of CRTH2 on eosinophils (PD). Simulations were used to identify doses and dosing regimens leading to 90 % of maximum blockade of CRTH2 internalization at trough. A combined concentration of ACT-453859 and its metabolite ACT-463036, with weights proportional to potency (based on an eosinophil shape change assay), enabled good characterization of the PD effect. The modelling and simulation results facilitated decision making by suggesting an ACT-453859 dose of 400 mg once daily (or 100 mg twice daily) for clinically relevant CRTH2 antagonism. Pharmacometric quantification demonstrated that CRTH2 internalization is a useful new biomarker to study CRTH2 antagonism. Ninety percent of maximum blockade of CRTH2 internalization at trough is suggested as a quantitative PD target in clinical studies.

  1. EXPOSURES AND INTERNAL DOSES OF TRIHALOMETHANES IN HUMANS: MULTI-ROUTE CONTRIBUTIONS FROM DRINKING WATER (FINAL)

    EPA Science Inventory

    The National Center for Environmental Assessment (NCEA) has released a final report that presents and applies a method to estimate distributions of internal concentrations of trihalomethanes (THMs) in humans resulting from a residential drinking water exposure. The report presen...

  2. International Exchange of Emergency Phase Information and Assessment: An Aid to Inter/National Decision Makers

    SciTech Connect

    Sullivan, T J; Chino, M; Ehrhardt, J; Shershakov, V

    2003-09-01

    This paper discusses a collaborative project whose purpose is (1) to demonstrate the technical feasibility and mutual benefit of a system seeking early review or preview, in a ''quasi peer review'' mode, of nuclear accident plume and dose assessment predictions by four major international nuclear accident emergency response systems before release of their calculations to their respective national authorities followed by (2) sharing these results with responsible international authorities. The extreme sensitivity of the general public to any nuclear accident information has been a strong motivation to seek peer review prior to public release. Another intended objective of this work is (3) the development of an affordable/accessible system for distribution of prediction results to countries having no prediction capabilities and (4) utilization of the link for exercises and collaboration studies. The project exploits the Internet as a ubiquitous communications medium, browser technology as a simple, user friendly interface, and low-cost PC level hardware. The participants are developing a web based dedicated node with ID and password access control, where the four systems can deposit a minimal set of XML-based data and graphics files, which are then displayed in a common identical map format. Side-by-side viewing and televideo conferencing will permit rapid evaluation, correction or elaboration of data, recalculation (if necessary) and should produce a strong level of consensus to assist international decision makers. Successful completion of this work could lead to easy utilization by national and international organizations, such as the IAEA and WHO, as well as by non-nuclear states at risk of a trans-boundary incursion on their territory.

  3. Possibilities for an International Assessment in Geography

    ERIC Educational Resources Information Center

    Lane, Rod; Bourke, Terri

    2017-01-01

    A recent editorial in International Research in Geographical and Environmental Education (IRGEE) highlighted an opportunity for the inclusion of geography as a subject in the Trends in International Mathematics and Science Study (TIMSS) tests. At present, TIMSS tests only encompass mathematics and physical sciences. The IRGEE editors encouraged…

  4. Possibilities for an International Assessment in Geography

    ERIC Educational Resources Information Center

    Lane, Rod; Bourke, Terri

    2017-01-01

    A recent editorial in International Research in Geographical and Environmental Education (IRGEE) highlighted an opportunity for the inclusion of geography as a subject in the Trends in International Mathematics and Science Study (TIMSS) tests. At present, TIMSS tests only encompass mathematics and physical sciences. The IRGEE editors encouraged…

  5. Calculation of internal dose from ingested soil-derived uranium in humans: Application of a new method.

    PubMed

    Träber, S C; Li, W B; Höllriegl, V; Nebelung, K; Michalke, B; Rühm, W; Oeh, U

    2015-08-01

    The aim of the present study was to determine the internal dose in humans after the ingestion of soil highly contaminated with uranium. Therefore, an in vitro solubility assay was performed to estimate the bioaccessibility of uranium for two types of soil. Based on the results, the corresponding bioavailabilities were assessed by using a recently published method. Finally, these bioavailability data were used together with the biokinetic model of uranium to assess the internal doses for a hypothetical but realistic scenario characterized by a daily ingestion of 10 mg of soil over 1 year. The investigated soil samples were from two former uranium mining sites of Germany with (238)U concentrations of about 460 and 550 mg/kg. For these soils, the bioavailabilities of (238)U were quantified as 0.18 and 0.28 % (geometric mean) with 2.5th percentiles of 0.02 and 0.03 % and 97.5th percentiles of 1.48 and 2.34 %, respectively. The corresponding calculated annual committed effective doses for the assumed scenario were 0.4 and 0.6 µSv (GM) with 2.5th percentiles of 0.2 and 0.3 µSv and 97.5th percentiles of 1.6 and 3.0 µSv, respectively. These annual committed effective doses are similar to those from natural uranium intake by food and drinking water, which is estimated to be 0.5 µSv. Based on the present experimental data and the selected ingestion scenario, the investigated soils-although highly contaminated with uranium-are not expected to pose any major health risk to humans related to radiation.

  6. Interactive Rapid Dose Assessment Model (IRDAM): reactor-accident assessment methods. Vol. 2

    SciTech Connect

    Poeton, R.W.; Moeller, M.P.; Laughlin, G.J.; Desrosiers, A.E.

    1983-05-01

    As part of the continuing emphasis on emergency preparedness, the US Nuclear Regulatory Commission (NRC) sponsored the development of a rapid dose assessment system by Pacific Northwest Laboratory (PNL). This system, the Interactive Rapid Dose Assessment Model (IRDAM) is a micro-computer based program for rapidly assessing the radiological impact of accidents at nuclear power plants. This document describes the technical bases for IRDAM including methods, models and assumptions used in calculations. IRDAM calculates whole body (5-cm depth) and infant thyroid doses at six fixed downwind distances between 500 and 20,000 meters. Radionuclides considered primarily consist of noble gases and radioiodines. In order to provide a rapid assessment capability consistent with the capacity of the Osborne-1 computer, certain simplifying approximations and assumptions are made. These are described, along with default values (assumptions used in the absence of specific input) in the text of this document. Two companion volumes to this one provide additional information on IRDAM. The user's Guide (NUREG/CR-3012, Volume 1) describes the setup and operation of equipment necessary to run IRDAM. Scenarios for Comparing Dose Assessment Models (NUREG/CR-3012, Volume 3) provides the results of calculations made by IRDAM and other models for specific accident scenarios.

  7. Dose assessment to workers in a dicalcium phosphate production plant.

    PubMed

    Mulas, D; Garcia-Orellana, J; Casacuberta, N; Hierro, A; Moreno, V; Masqué, P

    2016-12-01

    The production of dicalcium phosphate (DCP) uses phosphate rock (PR) as a raw material. Sedimentary phosphate rocks are enriched with relevant concentrations of natural radionuclides from the (238)U decay chain (around 10(3) Bq·kg(-1)), leading to the need of controlling potential exposures to radiation of workers and members of the public in accordance with IAEA safety standards. Indeed, phosphate industries are classified as Naturally Occurring Radioactive Material (NORM) industries. Thus, the aim of this work is to assess the radiological risk of the workers in a DCP production plant located in the Iberian Peninsula (South-West Europe), which digests PR with hydrochloric acid. In the present study (238)U, (230)Th, (222)Rn, (210)Pb and (210)Po concentrations in aerosols (indoor and outdoor areas) are reported. Aerosols showed concentrations between 0.42-92 mBq·m(-3) for (238)U, 0.24-33 mBq·m(-3) for (230)Th, 0.67-147 mBq·m(-3) for (210)Pb and 0.09-34 mBq·m(-3) for (210)Po. Long-term exposure (four months) of passive (222)Rn detectors provided concentrations that ranged from detection limit (< DL) to 121 Bq·m(-3) in outdoor areas and from < DL to 211 Bq·m(-3) in indoor areas, similar to concentrations obtained from short-term measurements with active detectors from < DL to 117 Bq·m(-3) in outdoor areas and from < DL to 318 Bq·m(-3) in indoor places. (226)Ra accumulation in ebonite and pipe scales were the most important contributions to the ambient dose equivalent H*(10), resulting in 0.07 (background)-27 μSv·h(-1) with a median value of 1.1 μSv·h(-1). Average (222)Rn air concentrations were lower than the 300 Bq·m(-3) limit and therefore, according to European Directive 2013/59/EURATOM, (222)Rn concentration is excluded from the worker operational annual effective dose. Thus, considering the inhalation of aerosols and the external dose sources, the total effective dose determined for plant operators was 0.37 mSv·y(-1). Copyright © 2016 Elsevier

  8. ASSESSMENT OF EFFECTIVE DOSE FROM CONE BEAM CT IMAGING IN SPECT/CT EXAMINATION IN COMPARISON WITH OTHER MODALITIES.

    PubMed

    Tonkopi, Elena; Ross, Andrew A

    2016-12-01

    The aim of this study was to assess radiation dose from the cone beam computed tomography (CBCT) component of single photon emission tomography/computed tomography (SPECT/CT) examinations and to compare it with the radiopharmaceutical related dose as well as dose from multidetector computed tomography (MDCT). Effective dose (ED) from computed tomography (CT) was estimated using dose-length product values and anatomy-specific conversion factors. The contribution from the SPECT component was evaluated using ED per unit administered activity for the radiopharmaceuticals listed in the International Commission on Radiological Protection Publications 80 and 106. With the exception of cardiac studies (0.11 mSv), the CBCT dose (3.96-6.04 mSv) was similar to that from the radiopharmaceutical accounting for 29-56 % of the total ED from the examination. In comparison with MDCT examinations, the CBCT dose was 48 and 42 % lower for abdomen/pelvis and chest/abdomen/pelvis scans, respectively, while in the chest the CBCT scan resulted in higher dose (23 %). Radiation dose from the CT component should be taken into consideration when evaluating total SPECT/CT patient dose. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    SciTech Connect

    Akabani, G.; Poston, J.W. Sr. )

    1991-05-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system used relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, EGS4 Monte Carlo calculations were performed. Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessels sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No penetration of the radionuclide into the blood vessel was assumed nor was cross fire between the vessel assumed. The results are useful in assessing the dose to blood and blood vessel walls for different nuclear medicine procedures.

  10. Absorbed dose calculations to blood and blood vessels for internally deposited radionuclides

    SciTech Connect

    Akabani, G. ); Poston, J.W. . Dept. of Nuclear Engineering)

    1991-05-01

    At present, absorbed dose calculations for radionuclides in the human circulatory system used relatively simple models and are restricted in their applications. To determine absorbed doses to the blood and to the surface of the blood vessel wall, EGS4 Monte Carlo calculations were performed. Absorbed doses were calculated for the blood and the blood vessel wall (lumen) for different blood vessels sizes. The radionuclides chosen for this study were those commonly used in nuclear medicine. No diffusion of the radionuclide into the blood vessel was assumed nor cross fire between vessel was assumed. Results are useful in assessing the dose in blood and blood vessel walls for different nuclear medicine procedures. 6 refs., 6 figs., 5 tabs.

  11. Dosimetric evaluation of internal shielding in a high dose rate skin applicator

    PubMed Central

    Granero, Domingo; Perez-Calatayud, Jose; Carmona, Vicente; Pujades, M Carmen; Ballester, Facundo

    2011-01-01

    Purpose The Valencia HDR applicators are accessories of the microSelectron HDR afterloading system (Nucletron) shaped as truncated cones. The base of the cone is either 2 or 3 cm diameter. They are intended to treat skin lesions, being the typical prescription depth 3 mm. In patients with eyelid lesions, an internal shielding is very useful to reduce the dose to the ocular globe. The purpose of this work was to evaluate the dose enhancement from potential backscatter and electron contamination due to the shielding. Material and methods Two methods were used: a) Monte Carlo simulation, performed with the GEANT4 code, 2 cm Valencia applicator was placed on the surface of a water phantom in which 2 mm lead slab was located at 3 mm depth; b) radiochromic EBT films, used to verify the Monte Carlo results, positioning the films at 1.5, 3, 5 and 7 mm depth, inside the phantom. Two irradiations, with and without the lead shielding slab, were carried out. Results The Monte Carlo results showed that due to the backscatter component from the lead, the dose level raised to about 200% with a depth range of 0.5 mm. Under the lead the dose level was enhanced to about 130% with a depth range of 1 mm. Two millimeters of lead reduce the dose under the slab with about 60%. These results agree with film measurements within uncertainties. Conclusions In conclusion, the use of 2 mm internal lead shielding in eyelid skin treatments with the Valencia applicators were evaluated using MC methods and EBT film dosimetry. The minimum bolus thickness that was needed above and below the shielding was 0.5 mm and 1 mm respectively, and the shielding reduced the absorbed dose delivered to the ocular globe by about 60%. PMID:27877198

  12. High-Dose Daptomycin Therapy for Left-Sided Infective Endocarditis: a Prospective Study from the International Collaboration on Endocarditis

    PubMed Central

    Bayer, Arnold S.; Miró, Josè M.; Park, Lawrence P.; Guimarães, Armenio C.; Skoutelis, Athanasios; Fortes, Claudio Q.; Durante-Mangoni, Emanuele; Hannan, Margaret M.; Nacinovich, Francisco; Fernández-Hidalgo, Nuria; Grossi, Paolo; Tan, Ru-San; Holland, Thomas; Fowler, Vance G.; Corey, Ralph G.; Chu, Vivian H.

    2013-01-01

    The use of daptomycin in Gram-positive left-sided infective endocarditis (IE) has significantly increased. The purpose of this study was to assess the influence of high-dose daptomycin on the outcome of left-sided IE due to Gram-positive pathogens. This was a prospective cohort study based on 1,112 cases from the International Collaboration on Endocarditis (ICE)-Plus database and the ICE-Daptomycin Substudy database from 2008 to 2010. Among patients with left-sided IE due to Staphylococcus aureus, coagulase-negative staphylococci, and Enterococcus faecalis, we compared those treated with daptomycin (cohort A) to those treated with standard-of-care (SOC) antibiotics (cohort B). The primary outcome was in-hospital mortality. Time to clearance of bacteremia, 6-month mortality, and adverse events (AEs) ascribable to daptomycin were also assessed. There were 29 and 149 patients included in cohort A and cohort B, respectively. Baseline comorbidities did not differ between the two cohorts, except for a significantly higher prevalence of diabetes and previous episodes of IE among patients treated with daptomycin. The median daptomycin dose was 9.2 mg/kg of body weight/day. Two-thirds of the patients treated with daptomycin had failed a previous antibiotic regimen. In-hospital and 6-month mortalities were similar in the two cohorts. In cohort A, median time to clearance of methicillin-resistant S. aureus (MRSA) bacteremia was 1.0 day, irrespective of daptomycin dose, representing a significantly faster bacteremia clearance compared to SOC (1.0 versus 5.0 days; P < 0.01). Regimens with higher daptomycin doses were not associated with increased incidence of AEs. In conclusion, higher-dose daptomycin may be an effective and safe alternative to SOC in the treatment of left-sided IE due to common Gram-positive pathogens. PMID:24080644

  13. Commentary on the OECD's Programme for International Student Assessment 2012

    ERIC Educational Resources Information Center

    Froese-Germain, Bernie

    2013-01-01

    Every three years the focus of the international education community shifts to the release of the Programme for International Student Assessment (PISA) study conducted by the Organisation for Economic Co-operation and Development (OECD). No other international study of education commands as much attention as PISA. In an age of intense global…

  14. Non-Linear Dose-Response Relationships in Biology, Toxicology and Medicine - An International Conference

    SciTech Connect

    Calabrese, Edward J.; Kostecki, Paul T.

    2002-05-28

    Conference abstract book contains seven sections: Plenary-4 abstracts; Chemical-9 abstracts; Radiation-7 abstracts; Ultra Low Doses and Medicine-6 abstracts; Biomedical-11 abstracts; Risk Assessment-5 abstracts and Poster Sessions-25 abstracts. Each abstract was provided by the author/presenter participating in the conference.

  15. Screening level dose assessment of aquatic biota downstream of the Marcoule nuclear complex in southern France

    SciTech Connect

    St-Pierre, S.; Chambers, D.B.; Lowe, L.M.; Bontoux, J.G.

    1999-09-01

    Aquatic biota in the Rhone River downstream of the Marcoule nuclear complex in France are exposed to natural sources of radiation and to radioactivity released from the Marcoule complex. A simple conservative screening level model was used to estimate the range of concentrations in aquatic media of both artificial and natural radionuclides and the consequent absorbed dose rates for aquatic organisms. Five categories of aquatic organisms were studied, namely, submerged aquatic plants (phanerogam), non-bottom-feeding fish, bottom-feeding fish, mollusca, and fish-eating birds. The analysis was based on the radionuclide concentrations reported in four consecutive annual radioecological monitoring reports published by French agencies with nuclear regulatory responsibilities. The results of this assessment were used to determine, qualitatively, the magnitude of any potential health impacts on each of the five categories of aquatic organisms studied. The range of dose rate estimates ranged over three orders of magnitude, with maximum dose rates estimated to be in the order of 1 to 10 {micro}Gy h{sup {minus}1}. These maximum dose rates are a factor 40 or more below the international guideline intended to ensure the protection of aquatic populations, and a factor ten or more below the level which may trigger the need for a more detailed evaluation of potential ecological consequences to the exposed populations.

  16. Diffuse and fugitive emission dose assessment on the Hanford Site

    SciTech Connect

    Davis, W.E.; Schmidt, J.W.; Gleckler, B.P.; Rhoads, K.

    1995-01-01

    On February 3, 1993, the US Department of Energy, Richland Operations Office (RL), received a Compliance Order and Information Request from the Director of the Air and Toxics Division of the US Environmental Protection Agency (EPA), Region 10. The Compliance Order requires RL to (1) evaluate all radionuclide emission points at the Hanford Site to determine which are subject to continuous emission measurement requirements in 40 Code of Federal Regulations (CFR) 61, Subpart H, and (2) continuously measure radionuclide emissions in accordance with 40 CFR 61.93. The Information Request requires RL to provide a written Compliance Plan to meet the requirements of the Compliance Order. The RL Compliance Plan included as one of its milestones the requirement to develop a Federal Facility Compliance Agreement (FFCA). An FFCA was negotiated between RL and the EPA, Region 10, and was entered into on February 7, 1994. One of the milestones was to provide EPA, Region 10, with a copy of the Federal Clean Air Act Title V operating air permit application and Air Emission Inventory (AEI) concurrent with its submission to the Washington State Department of Ecology. The AEI will include an assessment of the diffuse and fugitive emissions from the Hanford Site. This assessment does not identify any diffuse or fugitive emission source that would cause an effective dose equivalent greater than 0.1 mrem/yr.

  17. Occupational radiation dose to eyes from interventional radiology procedures in light of the new eye lens dose limit from the International Commission on Radiological Protection.

    PubMed

    O'Connor, U; Walsh, C; Gallagher, A; Dowling, A; Guiney, M; Ryan, J M; McEniff, N; O'Reilly, G

    2015-05-01

    In 2011, the International Commission on Radiological Protection (ICRP) recommended a substantial reduction in the equivalent dose limit for the lens of the eye, in line with a reduced threshold of absorbed dose for radiation-induced cataracts. This is of particular relevance in interventional radiology (IR) where it is well established that staff doses can be significant, however, there is a lack of data on IR eye doses in terms of Hp(3). Hp(3) is the personal dose equivalent at a depth of 3 mm in soft tissue and is used for measuring lens dose. We aimed to obtain a reliable estimate of eye dose to IR operators. Lens doses were measured for four interventional radiologists over a 3-month period using dosemeters specifically designed to measure Hp(3). Based on their typical workloads, two of the four interventional radiologists would exceed the new ICRP dose limit with annual estimated doses of 31 and 45 mSv to their left eye. These results are for an "unprotected" eye, and for IR staff who routinely wear lead glasses, the dose beneath the glasses is likely to be significantly lower. Staff eye dose normalized to patient kerma-area product and eye dose per procedure have been included in the analysis. Eye doses to IR operators have been established using a dedicated Hp(3) dosemeter. Estimated annual doses have the potential to exceed the new ICRP limit. We have estimated lens dose to interventional radiologists in terms of Hp(3) for the first time in an Irish hospital setting.

  18. Measurement of absorbed dose during the phantom torso experiment on the International Space Station

    NASA Astrophysics Data System (ADS)

    Semones, E.; Gibbons, F.; Golightly, M.; Weyland, M.; Johnson, A.; Smith, G.; Shelfer, T.; Zapp, N.

    The Phantom Torso Experiment (PTE) was flown on the International Space Station (ISS) during Increment 2 (April-August 2001). The experiment was located in the US Lab module Human Research Facility (HRF) rack. The objective of the passive dosimetry portion of the experiment was to measure spatial distributions of absorbed dose in the 34, 1 inch sections of a modified RandoTM phantom. In each section of the phantom, thermoluminescent detectors (TLDs) were placed at various locations (depths) to provide the spatial measurement. TLDs were also located at several radiosensitive organ locations (brain, thyroid, heart/lung, stomach and colon) and two locations on the surface (skin). Active silicon detectors were also placed at these organ locations to provide time resolved results of the absorbed dose rates. Using these detectors, it is possible to separate the trapped and galactic cosmic ray components of the absorbed dose. The TLD results of the spatial and organ dose measurements will be presented and comparisons of the TLD and silicon detector organ absorbed doses will be made.

  19. Internal thyroid doses to Fukushima residents—estimation and issues remaining

    PubMed Central

    Kim, Eunjoo; Kurihara, Osamu; Kunishima, Naoaki; Momose, Takumaro; Ishikawa, Tetsuo; Akashi, Makoto

    2016-01-01

    Enormous quantities of radionuclides were released into the environment following the disastrous accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011. It is of great importance to determine the exposure doses received by the populations living in the radiologically affected areas; however, there has been significant difficulty in estimating the internal thyroid dose received through the intake of short-lived radionuclides (mainly, 131I), because of the lack of early measurements on people. An estimation by the National Institute of Radiological Sciences for 1 April 2012 to 31 March 2013 was thus performed using a combination of the following three sources: thyroid measurement data (131I) for 1080 children examined in the screening campaign, whole-body counter measurement data (134Cs, 137Cs) for 3000 adults, and atmospheric transport dispersion model simulations. In this study, the residents of Futaba town, Iitate village and Iwaki city were shown to have the highest thyroid equivalent dose, and their doses were estimated to be mostly below 30 mSv. However, this result involved a lot of uncertainties and provided only representative values for the residents. The present paper outlines a more recent dose estimation and preliminary analyses of personal behavior data used in the new method. PMID:27538842

  20. Establishing bounding internal dose estimates for thorium activities at Rocky Flats.

    PubMed

    Ulsh, Brant A; Rich, Bryce L; Chew, Melton H; Morris, Robert L; Sharfi, Mutty; Rolfes, Mark R

    2008-07-01

    As part of an evaluation of a Special Exposure Cohort petition filed on behalf of workers at the Rocky Flats Plant, the National Institute for Occupational Safety and Health (NIOSH) was required to demonstrate that bounding values could be established for radiation doses due to the potential intake of all radionuclides present at the facility. The main radioactive elements of interest at Rocky Flats were plutonium and uranium, but much smaller quantities of several other elements, including thorium, were occasionally handled at the site. Bounding potential doses from thorium has proven challenging at other sites due to the early historical difficulty in detecting this element through urinalysis methods and the relatively high internal dose delivered per unit intake. This paper reports the results of NIOSH's investigation of the uses of thorium at Rocky Flats and provides bounding dose reconstructions for these operations. During this investigation, NIOSH reviewed unclassified reports, unclassified extracts of classified materials, material balance and inventory ledgers, monthly progress reports from various groups, and health physics field logbooks, and conducted interviews with former Rocky Flats workers. Thorium operations included: (1) an experimental metal forming project with 240 kg of thorium in 1960; (2) the use of pre-formed parts in weapons mockups; (3) the removal of Th from U; (4) numerous analytical procedures involving trace quantities of thorium; and (5) the possible experimental use of thorium as a mold coating compound. The thorium handling operations at Rocky Flats were limited in scope, well-monitored and documented, and potential doses can be bounded.

  1. The Internal Consultant Model for Assessment

    ERIC Educational Resources Information Center

    Lewis, Kristi L.; Swerdzewski, Peter J.

    2009-01-01

    Many universities rely on a committee approach to assessment in which a group of faculty, staff, and administrators is tapped to provide guidance for assessment projects on behalf of various university programs or departments or the entire university. However, other organizational approaches to achieving strong programs of assessment are…

  2. The Internal Consultant Model for Assessment

    ERIC Educational Resources Information Center

    Lewis, Kristi L.; Swerdzewski, Peter J.

    2009-01-01

    Many universities rely on a committee approach to assessment in which a group of faculty, staff, and administrators is tapped to provide guidance for assessment projects on behalf of various university programs or departments or the entire university. However, other organizational approaches to achieving strong programs of assessment are…

  3. The effective dose assessment of C-arm CT in hepatic arterial embolisation therapy.

    PubMed

    Tyan, Y-S; Li, Y-Y; Ku, M-C; Huang, H-H; Chen, T-R

    2013-04-01

    To assess the effective dose of the liver C-arm computed tomography (CT) scan during hepatic arterial embolisation surgery with clinical dose-area product (DAP) data from Taiwan. The experiment used two kinds of phantoms: RANDO® Man and RANDO Woman (The Phantom Laboratory, Salem, NY), embedded with thermoluminescent dosemeters at locations according to the International Commission on Radiological Protection 103 report. The conversion factors of DAP to effective doses for males and females, respectively, were obtained. The clinical DAP data of liver C-arm CT scan during hepatic arterial embolisation surgery were collected in a hospital in Taiwan. There were 125 liver transarterial embolisation therapy cases, including 94 males and 31 females, from February 2009 to June 2010. C-arm CT was used 38 times for males and 17 times for females. The corresponding average and standard deviation of clinical DAP were 61.0±6.6 Gy cm(2) and 52.2±8.3 Gy cm(2), respectively. The DAP of RANDO Man and RANDO Woman phantoms simply scanned by C-arm CT are much lower than that of patients. After consideration of the clinical DAP of patients, the effective doses of a liver C-arm CT scan recommended for males and females in Taiwan are 11.5±2.3 mSv and 11.3±3.0 mSv, respectively. The conversion factors of DAP to effective doses for males and females are 0.19±0.03 mSv Gy(-1) cm(-2) and 0.22±0.05 mSv Gy(-1) cm(-2). Only if the actual DAP value of a patient scan is multiplied by the conversion factor can the correct effective dose be determined.

  4. An international dosimetry exchange for boron neutron capture therapy. Part I: Absorbed dose measurements.

    PubMed

    Binns, P J; Riley, K J; Harling, O K; Kiger, W S; Munck af Rosenschöld, P M; Giusti, V; Capala, J; Sköld, K; Auterinen, I; Serén, T; Kotiluoto, P; Uusi-Simola, J; Marek, M; Viererbl, L; Spurny, F

    2005-12-01

    An international collaboration was organized to undertake a dosimetry exchange to enable the future combination of clinical data from different centers conducting neutron capture therapy trials. As a first step (Part I) the dosimetry group from the Americas, represented by MIT, visited the clinical centers at Studsvik (Sweden), VTT Espoo (Finland), and the Nuclear Research Institute (NRI) at Rez (Czech Republic). A combined VTT/NRI group reciprocated with a visit to MIT. Each participant performed a series of dosimetry measurements under equivalent irradiation conditions using methods appropriate to their clinical protocols. This entailed in-air measurements and dose versus depth measurements in a large water phantom. Thermal neutron flux as well as fast neutron and photon absorbed dose rates were measured. Satisfactory agreement in determining absorbed dose within the experimental uncertainties was obtained between the different groups although the measurement uncertainties are large, ranging between 3% and 30% depending upon the dose component and the depth of measurement. To improve the precision in the specification of absorbed dose amongst the participants, the individually measured dose components were normalized to the results from a single method. Assuming a boron concentration of 15 microg g(-1) that is typical of concentrations realized clinically with the boron delivery compound boronophenylalanine-fructose, systematic discrepancies in the specification of the total biologically weighted dose of up to 10% were apparent between the different groups. The results from these measurements will be used in future to normalize treatment plan calculations between the different clinical dosimetry protocols as Part II of this study.

  5. Contracting Processes, Internal Controls, and Procurement Fraud: A Knowledge Assessment

    DTIC Science & Technology

    2015-04-30

    assess DoD contracting officers??? knowledge of the DoD???s contract management processes and related internal controls. Our research findings indicated... knowledge of the DoD’s contract management processes and related internal controls. Our research findings indicated contracting officers may have a...internal controls. The purpose of this research was to assess DoD contracting officers’ knowledge of the DoD’s contract management processes and related

  6. Technology Assessment and Roadmap for the Emergency Radiation Dose Assessment Program

    SciTech Connect

    Turteltaub, K W; Hartman-Siantar, C; Easterly, C; Blakely, W

    2005-10-03

    A Joint Interagency Working Group (JIWG) under the auspices of the Department of Homeland Security Office of Research and Development conducted a technology assessment of emergency radiological dose assessment capabilities as part of the overall need for rapid emergency medical response in the event of a radiological terrorist event in the United States. The goal of the evaluation is to identify gaps and recommend general research and development needs to better prepare the Country for mitigating the effects of such an event. Given the capabilities and roles for responding to a radiological event extend across many agencies, a consensus of gaps and suggested development plans was a major goal of this evaluation and road-mapping effort. The working group consisted of experts representing the Departments of Homeland Security, Health and Human Services (Centers for Disease Control and the National Institutes of Health), Food and Drug Administration, Department of Defense and the Department of Energy's National Laboratories (see appendix A for participants). The specific goals of this Technology Assessment and Roadmap were to: (1) Describe the general context for deployment of emergency radiation dose assessment tools following terrorist use of a radiological or nuclear device; (2) Assess current and emerging dose assessment technologies; and (3) Put forward a consensus high-level technology roadmap for interagency research and development in this area. This report provides a summary of the consensus of needs, gaps and recommendations for a research program in the area of radiation dosimetry for early response, followed by a summary of the technologies available and on the near-term horizon. We then present a roadmap for a research program to bring present and emerging near-term technologies to bear on the gaps in radiation dose assessment and triage. Finally we present detailed supporting discussion on the nature of the threats we considered, the status of technology

  7. History of the international societies in health technology assessment: International Society for Technology Assessment in Health Care and Health Technology Assessment International.

    PubMed

    Banta, David; Jonsson, Egon; Childs, Paul

    2009-07-01

    The International Society for Technology Assessment in Health Care (ISTAHC) was formed in 1985. It grew out of the increasing awareness of the international dimensions of health technology assessment (HTA) and the need for new communication methods at the international level. The main function of ISTAHC was to present an annual conference, which gradually grew in size, and also to generally improve in quality from to year. ISTAHC overextended itself financially early in the first decade of the 2000s and had to cease its existence. A new society, Health Technology Assessment international (HTAi), based on many of the same ideas and people, grew up beginning in the year 2003. The two societies have played a large role in making the field of HTA visible to people around the world and providing a forum for discussion on the methods and role of HTA.

  8. Dose assessment in environmental radiological protection: State of the art and perspectives.

    PubMed

    Stark, Karolina; Goméz-Ros, José M; Vives I Batlle, Jordi; Lindbo Hansen, Elisabeth; Beaugelin-Seiller, Karine; Kapustka, Lawrence A; Wood, Michael D; Bradshaw, Clare; Real, Almudena; McGuire, Corynne; Hinton, Thomas G

    2017-09-01

    Exposure to radiation is a potential hazard to humans and the environment. The Fukushima accident reminded the world of the importance of a reliable risk management system that incorporates the dose received from radiation exposures. The dose to humans from exposure to radiation can be quantified using a well-defined system; its environmental equivalent, however, is still in a developmental state. Additionally, the results of several papers published over the last decade have been criticized because of poor dosimetry. Therefore, a workshop on environmental dosimetry was organized by the STAR (Strategy for Allied Radioecology) Network of Excellence to review the state of the art in environmental dosimetry and prioritize areas of methodological and guidance development. Herein, we report the key findings from that international workshop, summarise parameters that affect the dose animals and plants receive when exposed to radiation, and identify further research needs. Current dosimetry practices for determining environmental protection are based on simple screening dose assessments using knowledge of fundamental radiation physics, source-target geometry relationships, the influence of organism shape and size, and knowledge of how radionuclide distributions in the body and in the soil profile alter dose. In screening model calculations that estimate whole-body dose to biota the shapes of organisms are simply represented as ellipsoids, while recently developed complex voxel phantom models allow organ-specific dose estimates. We identified several research and guidance development priorities for dosimetry. For external exposures, the uncertainty in dose estimates due to spatially heterogeneous distributions of radionuclide contamination is currently being evaluated. Guidance is needed on the level of dosimetry that is required when screening benchmarks are exceeded and how to report exposure in dose-effect studies, including quantification of uncertainties. Further

  9. PHYSIOLOCIGALLY BASED PHARMACOKINETIC (PBPK) MODELING AND MODE OF ACTION IN DOSE-RESPONSE ASSESSMENT

    EPA Science Inventory

    PHYSIOLOGICALLY BASED PHARMACOKINETIC (PBPK) MODELING AND MODE OF ACTION IN DOSE-RESPONSE ASSESSMENT. Barton HA. Experimental Toxicology Division, National Health and Environmental Effects Laboratory, ORD, U.S. EPA
    Dose-response analysis requires quantitatively linking infor...

  10. ASSESSING POPULATION EXPOSURES TO MULTIPLE AIR POLLUTANTS USING A MECHANISTIC SOURCE-TO-DOSE MODELING FRAMEWORK

    EPA Science Inventory

    The Modeling Environment for Total Risks studies (MENTOR) system, combined with an extension of the SHEDS (Stochastic Human Exposure and Dose Simulation) methodology, provide a mechanistically consistent framework for conducting source-to-dose exposure assessments of multiple pol...

  11. ASSESSING POPULATION EXPOSURES TO MULTIPLE AIR POLLUTANTS USING A MECHANISTIC SOURCE-TO-DOSE MODELING FRAMEWORK

    EPA Science Inventory

    The Modeling Environment for Total Risks studies (MENTOR) system, combined with an extension of the SHEDS (Stochastic Human Exposure and Dose Simulation) methodology, provide a mechanistically consistent framework for conducting source-to-dose exposure assessments of multiple pol...

  12. Imaging dose assessment for IGRT in particle beam therapy.

    PubMed

    Steiner, Elisabeth; Stock, Markus; Kostresevic, Boris; Ableitinger, Alexander; Jelen, Urszula; Prokesch, Hannah; Santiago, Alina; Trnková, Petra; Wolf, Adam; Wittig, Andrea; Lomax, Antony; Jäkel, Oliver; Baroni, Guido; Georg, Dietmar

    2013-12-01

    Image-guided advanced photon and particle beam treatments are promising options for improving lung treatments. Extensive use of imaging increases the overall patient dose. The aim of this study was to determine the imaging dose for different IGRT solutions used in photon and particle beam therapy. Measurements were performed in an Alderson phantom with TLDs. Clinically applied protocols for orthogonal planar kV imaging, stereoscopic imaging, CT scout views, fluoroscopy, CT, 4D-CT and CBCT were investigated at five ion beam centers and one conventional radiotherapy department. The overall imaging dose was determined for a patient undergoing a lung tumor irradiation with institute specific protocols. OAR doses depended on imaging modality and OAR position. Dose values were in the order of 1 mGy for planar and stereoscopic imaging and 10-50 mGy for volumetric imaging, except for one CBCT device leading to lower doses. The highest dose per exam (up to 150 mGy to the skin) was recorded for a 3-min fluoroscopy. Modalities like planar kV or stereoscopic imaging result in very low doses (≈ 1 mGy) to the patient. Imaging a moving target during irradiation, low-dose protocols and protocol optimization can reduce the imaging dose to the patient substantially. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  13. Radiological Dose Assessment - Nonuniform Skin Dose, Radioactive Skin Contamination, and Multiple Dosimetry

    SciTech Connect

    W. C. Inkret; M. E. Schillaci

    1999-03-01

    Radioactive skin contamination with {beta}- and {gamma}-emitting radionuclides may result in biologically significant absorbed doses to the skin. A specific exposure scenario of interest is a nonuniform skin dose delivered by {beta}- and {gamma}-emissions from radioactive skin contamination. The United States Department of Energy requires a formal evaluation and reporting of nonuniform skin doses. The United States Department of Energy also requires specific, formal procedures for evaluating the results from the placement or use of multiple dosimeters. Action levels relative to potential absorbed doses for the contamination survey instrumentation in use at Los Alamos and formal procedures for evaluating nonuniform skin doses and multiple dosimeters are developed and presented here.

  14. Dose assessment from chronic exposure to industrial NORM in iron ore processing.

    PubMed

    Dal Molin, Franck; Fisher, Raymond; Frost, David; Anderson, David R; Read, David

    2017-09-05

    Radiological exposures due to naturally occurring radioactive material (NORM) can occur during a wide range of work-related activities in the mineral processing and chemical industries. However, evaluation of such exposures in industrial settings remains a difficult exercise owing inter alia to the large number of personnel, operations and plants affected; assumptions that often have to be made concerning the actual duration and frequency of exposures; the complex chemistry and radioactive disequilibria involved and typically, the paucity of historical data. In our study, the challenges associated with assessing chronic exposure to fugitive dust enriched in 210Pb and 210Po and the determination of the associated internal dose by inhalation and ingestion are described by reference to a case study undertaken at an iron ore sintering plant between June 2013 and July 2015. The applicability of default dose coefficients and biokinetic models provided by the International Commission for Radiological Protection (ICRP) was verified by combining air and dust monitoring with information on the characteristics of the aerosols and in-vitro solubility experiments. The disparity between particulate matter 100 microns or less in diameter (PM100), particulate matter 10 microns or less in diameter (PM10) and 210Pb/210Po activity concentrations observed over the different monitoring campaigns and sampling locations confirmed that use of positional short-term monitoring surveys to extrapolate intake over a year was not appropriate and could lead to unrealistic intake and dose figures. Personal air sampling is more appropriate for estimating the dose in such situations, though it is not always practical and may collect insufficient quantities of material for radiochemical analysis; this is an important constraint when dealing with low specific activity materials. © 2017 IOP Publishing Ltd.

  15. Dose assessment from chronic exposure to industrial NORM in iron ore processing.

    PubMed

    Dal-Molin, Franck; Fisher, Raymond; Frost, David; Anderson, David R; Read, David

    2017-06-26

    Radiological exposures due to naturally occurring radioactive material (NORM) can occur during a wide range of work-related activities in the mineral processing and chemical industries. However, evaluation of such exposures in industrial settings remains a difficult exercise owing inter alia to the large number of personnel, operations and plants affected; assumptions that often have to be made concerning the actual duration and frequency of exposures; the complex chemistry and radioactive disequilibria involved and typically, the paucity of historical data. In our study, the challenges associated with assessing chronic exposure to fugitive dust enriched in (210)Pb and (210)Po and the determination of the associated internal dose by inhalation and ingestion are described by reference to a case study undertaken at an iron ore sintering plant between June 2013 and July 2015. The applicability of default dose coefficients and biokinetic models provided by the International Commission for Radiological Protection was verified by combining air and dust monitoring with information on the characteristics of the aerosols and in-vitro solubility experiments. The disparity between particulate matter 100 microns or less in diameter (PM100), particulate matter 10 microns or less in diameter (PM10) and (210)Pb/(210)Po activity concentrations observed over the different monitoring campaigns and sampling locations confirmed that use positional short-term monitoring surveys to extrapolate intake over a year was not appropriate and could lead to unrealistic intake and dose figures. Personal air sampling is more appropriate for estimating the dose in such situations, though it is not always practical and may collect insufficient quantities of material for radiochemical analysis; this is an important constraint when dealing with low specific activity materials.

  16. Internal Dose from Food and Drink Ingestion in the Early Phase after the Accident

    NASA Astrophysics Data System (ADS)

    Kawai, Masaki; Yoshizawa, Nobuaki; Hirakawa, Sachiko; Murakami, Kana; Takizawa, Mari; Sato, Osamu; Takagi, Shunji; Miyatake, Hirokazu; Takahashi, Tomoyuki; Suzuki, Gen

    2017-09-01

    Activity concentrations in food and drink, represented by water and vegetables, have been monitored continuously since the Fukushima Daiichi Nuclear Power Plant accident, with a focus on radioactive cesium. On the other hand, iodine-131 was not measured systematically in the early phase after the accident. The activity concentrations of iodine-131 in food and drink are important to estimate internal exposure due to ingestion pathway. When the internal dose from ingestion in the evacuation areas is estimated, water is considered as the main ingestion pathway. In this study, we estimated the values of activity concentrations in water in the early phase after the accident, using a compartment model as an estimation method. The model uses measurement values of activity concentration and deposition rate of iodine-131 onto the ground, which is calculated from an atmospheric dispersion simulation. The model considers how drinking water would be affected by radionuclides deposited into water. We estimated the activity concentrations of water on Kawamata town and Minamisouma city during March of 2011 and the committed effective doses were 0.08 mSv and 0.06 mSv. We calculated the transfer parameters in the model for estimating the activity concentrations in the areas with a small amount of measurement data. In addition, we estimated the committed effective doses from vegetables using atmospheric dispersion simulation and FARMLAND model in case of eating certain vegetables as option information.

  17. Cardiac monitoring of high-dose verapamil in cluster headache: An international Delphi study.

    PubMed

    Koppen, H; Stolwijk, J; Wilms, E B; van Driel, V; Ferrari, M D; Haan, J

    2016-12-01

    In many patients, high-dose verapamil (HDV) is the only effective prophylactic treatment for cluster headache. Although cardiac adverse events and EKG abnormalities are relatively common, evidence-based guidelines for screening and monitoring patients on HDV are lacking. Using the Delphi approach, we interviewed 22 international clinical experts in cardiac rhythm disorders to formulate EKG guidelines for the pretreatment screening and monitoring of cluster headache patients using HDV. The panel agreed only on performing pretreatment EKG to screen for pre-existing cardiac arrhythmia. Pretreatment EKG was deemed not necessary by most panel members for patients who did not have cardiac adverse events during a previous period of cluster headache attacks treated with HDV. Half the panel advised Holter EKG for patients on verapamil ≥ 480 mg/day. The highest recommended daily doses varied between 240 and 960 mg. Contraindications for use of verapamil largely followed FDA guidelines. Experts in cardiac rhythm disorders agreed on pretreatment EKG monitoring, but no consensus was reached on EKG monitoring during HDV treatment and around dose adjustments. © International Headache Society 2016.

  18. Assessment of the Annual Additional Effective Doses amongst Minamisoma Children during the Second Year after the Fukushima Daiichi Nuclear Power Plant Disaster.

    PubMed

    Tsubokura, Masaharu; Kato, Shigeaki; Morita, Tomohiro; Nomura, Shuhei; Kami, Masahiro; Sakaihara, Kikugoro; Hanai, Tatsuo; Oikawa, Tomoyoshi; Kanazawa, Yukio

    2015-01-01

    An assessment of the external and internal radiation exposure levels, which includes calculation of effective doses from chronic radiation exposure and assessment of long-term radiation-related health risks, has become mandatory for residents living near the nuclear power plant in Fukushima, Japan. Data for all primary and secondary children in Minamisoma who participated in both external and internal screening programs were employed to assess the annual additional effective dose acquired due to the Fukushima Daiichi nuclear power plant disaster. In total, 881 children took part in both internal and external radiation exposure screening programs between 1st April 2012 to 31st March 2013. The level of additional effective doses ranged from 0.025 to 3.49 mSv/year with the median of 0.70 mSv/year. While 99.7% of the children (n = 878) were not detected with internal contamination, 90.3% of the additional effective doses was the result of external radiation exposure. This finding is relatively consistent with the doses estimated by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The present study showed that the level of annual additional effective doses among children in Minamisoma has been low, even after the inter-individual differences were taken into account. The dose from internal radiation exposure was negligible presumably due to the success of contaminated food control.

  19. Assessment of the Annual Additional Effective Doses amongst Minamisoma Children during the Second Year after the Fukushima Daiichi Nuclear Power Plant Disaster

    PubMed Central

    Tsubokura, Masaharu; Kato, Shigeaki; Morita, Tomohiro; Nomura, Shuhei; Kami, Masahiro; Sakaihara, Kikugoro; Hanai, Tatsuo; Oikawa, Tomoyoshi; Kanazawa, Yukio

    2015-01-01

    An assessment of the external and internal radiation exposure levels, which includes calculation of effective doses from chronic radiation exposure and assessment of long-term radiation-related health risks, has become mandatory for residents living near the nuclear power plant in Fukushima, Japan. Data for all primary and secondary children in Minamisoma who participated in both external and internal screening programs were employed to assess the annual additional effective dose acquired due to the Fukushima Daiichi nuclear power plant disaster. In total, 881 children took part in both internal and external radiation exposure screening programs between 1st April 2012 to 31st March 2013. The level of additional effective doses ranged from 0.025 to 3.49 mSv/year with the median of 0.70 mSv/year. While 99.7% of the children (n = 878) were not detected with internal contamination, 90.3% of the additional effective doses was the result of external radiation exposure. This finding is relatively consistent with the doses estimated by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The present study showed that the level of annual additional effective doses among children in Minamisoma has been low, even after the inter-individual differences were taken into account. The dose from internal radiation exposure was negligible presumably due to the success of contaminated food control. PMID:26053271

  20. Environmental dose assessment methods for normal operations at DOE nuclear sites

    SciTech Connect

    Strenge, D.L.; Kennedy, W.E. Jr.; Corley, J.P.

    1982-09-01

    Methods for assessing public exposure to radiation from normal operations at DOE facilities are reviewed in this report. The report includes a discussion of environmental doses to be calculated, a review of currently available environmental pathway models and a set of recommended models for use when environmental pathway modeling is necessary. Currently available models reviewed include those used by DOE contractors, the Environmental Protection Agency (EPA), the Nuclear Regulatory Commission (NRC), and other organizations involved in environmental assessments. General modeling areas considered for routine releases are atmospheric transport, airborne pathways, waterborne pathways, direct exposure to penetrating radiation, and internal dosimetry. The pathway models discussed in this report are applicable to long-term (annual) uniform releases to the environment: they do not apply to acute releases resulting from accidents or emergency situations.

  1. Austrian dose measurements onboard space station MIR and the International Space Station - overview and comparison

    NASA Astrophysics Data System (ADS)

    Berger, T.; Hajek, M.; Summerer, L.; Vana, N.; Akatov, Y.; Shurshakov, V.; Arkhangelsky, V.

    2004-01-01

    The Atominstitute of the Austrian Universities has conducted various space research missions in the last 12 years in cooperation with the Institute for Biomedical Problems in Moscow. They dealt with the exact determination of the radiation hazards for cosmonauts and the development of precise measurement devices. Special emphasis will be laid on the last experiment on space station MIR the goal of which was the determination of the depth distribution of absorbed dose and dose equivalent in a water filled Phantom. The first results from dose measurements onboard the International Space Station (ISS) will also be discussed. The spherical Phantom with a diameter of 35 cm was developed at the Institute for Biomedical Problems and had 4 channels where dosemeters can be exposed in different depths. The exposure period covered the timeframe from May 1997 to February 1999. Thermoluminescent dosemeters (TLDs) were exposed inside the Phantom, either parallel or perpendicular to the hull of the spacecraft. For the evaluation of the linear energy transfer (LET), the high temperature ratio (HTR) method was applied. Based on this method a mean quality factor and, subsequently, the dose equivalent is calculated according to the Q(LET ∞) relationship proposed in ICRP 26. An increased contribution of neutrons could be detected inside the Phantom. However the total dose equivalent did not increase over the depth of the Phantom. As the first Austrian measurements on the ISS dosemeter packages were exposed for 248 days, starting in February 2001 at six different locations onboard the ISS. The Austrian dosemeter sets for this first exposure on the ISS contained five different kinds of passive thermoluminescent dosemeters. First results showed a position dependent absorbed dose rate at the ISS.

  2. Impact of Internal Metallic Ports in Temporary Tissue Expanders on Postmastectomy Radiation Dose Distribution

    SciTech Connect

    Chen, Susie A.; Ogunleye, Tomiwa; Dhabbaan, Anees; Huang, Eugene H.; Losken, Albert; Gabram, Sheryl; Davis, Lawrence; Torres, Mylin A.

    2013-03-01

    Purpose: Temporary tissue expanders (TTE) with an internal magnetic metal port (IMP) have been increasingly used for breast reconstruction in post-mastectomy patients who receive radiation therapy (XRT). We evaluated XRT plans of patients with IMP to determine its effect on XRT dose distribution. Methods and Materials: Original treatment plans with CT simulation scans of 24 consecutive patients who received XRT (ORI), planned without heterogeneity corrections, to a reconstructed breast containing an IMP were used. Two additional treatment plans were then generated: one treatment plan with the IMP assigned the electron density of the rare earth magnet, nickel plated neodymium-iron-boron (HET), and a second treatment plan with the IMP assigned a CT value of 1 to simulate a homogeneous breast without an IMP (BRS). All plans were prescribed 50 Gy to the reconstructed breast (CTV). Results: CTV coverage by 50 Gy was significantly lower in the HET (mean 87.7% CTV) than in either the ORI (mean 99.7% CTV, P<.001) or BRS plans (mean 95.0% CTV, P<.001). The effect of the port was more pronounced on CT slices containing the IMP with prescription dose coverage of the CTV being less in the HET than in either ORI (mean difference 33.6%, P<.01) or BRS plans (mean difference 30.1%, P<.001). HET had a less homogeneous and conformal dose distribution than BRS or ORI. Conclusion: IMPs increase dose heterogeneity and reduce dose to the breast CTV through attenuation of the beam. For optimal XRT treatment, heterogeneity corrections should be used in XRT planning for patients with TTE with IMP, as the IMP impacts dose distribution.

  3. Evaluation of various approaches for assessing dose indicators and patient organ doses resulting from radiotherapy cone-beam CT

    SciTech Connect

    Rampado, Osvaldo Giglioli, Francesca Romana; Rossetti, Veronica; Ropolo, Roberto; Fiandra, Christian; Ragona, Riccardo

    2016-05-15

    Purpose: The aim of this study was to evaluate various approaches for assessing patient organ doses resulting from radiotherapy cone-beam CT (CBCT), by the use of thermoluminescent dosimeter (TLD) measurements in anthropomorphic phantoms, a Monte Carlo based dose calculation software, and different dose indicators as presently defined. Methods: Dose evaluations were performed on a CBCT Elekta XVI (Elekta, Crawley, UK) for different protocols and anatomical regions. The first part of the study focuses on using PCXMC software (PCXMC 2.0, STUK, Helsinki, Finland) for calculating organ doses, adapting the input parameters to simulate the exposure geometry, and beam dose distribution in an appropriate way. The calculated doses were compared to readouts of TLDs placed in an anthropomorphic Rando phantom. After this validation, the software was used for analyzing organ dose variability associated with patients’ differences in size and gender. At the same time, various dose indicators were evaluated: kerma area product (KAP), cumulative air-kerma at the isocenter (K{sub air}), cone-beam dose index, and central cumulative dose. The latter was evaluated in a single phantom and in a stack of three adjacent computed tomography dose index phantoms. Based on the different dose indicators, a set of coefficients was calculated to estimate organ doses for a range of patient morphologies, using their equivalent diameters. Results: Maximum organ doses were about 1 mGy for head and neck and 25 mGy for chest and pelvis protocols. The differences between PCXMC and TLDs doses were generally below 10% for organs within the field of view and approximately 15% for organs at the boundaries of the radiation beam. When considering patient size and gender variability, differences in organ doses up to 40% were observed especially in the pelvic region; for the organs in the thorax, the maximum differences ranged between 20% and 30%. Phantom dose indexes provided better correlation with organ

  4. Internal assessment of practical coursework in GCSE

    NASA Astrophysics Data System (ADS)

    Skevington, John H.

    1986-07-01

    The proposed introduction in September 1986 of a system of examinations to replace the present GCE O-level and CSE will impose on teachers the responsibility for a significant proportion of the assessment of their pupils. In addition, the adoption of the National Criteria for GCSE means that there will be some degree of commonality imposed on all physics syllabuses and schemes of assessment. One of the requirements of the criteria is that all examinations at this level will include an assessment of practical skills in the laboratory and that this will be carried out by the teacher. The introduction of a compulsory assessment of practical and experimental skills for all candidates, together with the requirement that this should be, at least in part, the assessment of practical work carried out as part of the course, is a source of concern for many teachers. The author outlines the schemes of practical assessment, which have been accepted by the SEC as meeting the National Criteria, showing how they develop from the relevant objectives in the criteria, and suggests how teachers might begin to produce their own assessment programme.

  5. LIFE CYCLE ASSESSMENT: AN INTERNATIONAL EXPERIENCE

    EPA Science Inventory

    Life Cycle Assessment (LCA) is used to evaluate environmental burdens associated with a product, process or activity by identifying and quantifying relevant inputs and outputs of the defined system and evaluating their potential impacts. This article outlines the four components ...

  6. LIFE CYCLE ASSESSMENT: AN INTERNATIONAL EXPERIENCE

    EPA Science Inventory

    Life Cycle Assessment (LCA) is used to evaluate environmental burdens associated with a product, process or activity by identifying and quantifying relevant inputs and outputs of the defined system and evaluating their potential impacts. This article outlines the four components ...

  7. Pediatric cardiac-gated CT angiography: assessment of radiation dose.

    PubMed

    Hollingsworth, Caroline L; Yoshizumi, Terry T; Frush, Donald P; Chan, Frandics P; Toncheva, Greta; Nguyen, Giao; Lowry, Carolyn R; Hurwitz, Lynne M

    2007-07-01

    The purpose of our study was to determine a dose range for cardiac-gated CT angiography (CTA) in children. ECG-gated cardiac CTA simulating scanning of the heart was performed on an anthropomorphic phantom of a 5-year-old child on a 16-MDCT scanner using variable parameters (small field of view; 16 x 0.625 mm configuration; 0.5-second gantry cycle time; 0.275 pitch; 120 kVp at 110, 220, and 330 mA; and 80 kVp at 385 mA). Metal oxide semiconductor field effect transistor (MOSFET) technology measured 20 organ doses. Effective dose calculated using the dose-length product (DLP) was compared with effective dose determined from measured absorbed organ doses. Highest organ doses included breast (3.5-12.6 cGy), lung (3.3-12.1 cGy), and bone marrow (1.7-7.6 cGy). The 80 kVp/385 mA examination produced lower radiation doses to all organs than the 120 kVp/220 mA examination. MOSFET effective doses (+/- SD) were as follows: 110 mA: 7.4 mSv (+/- 0.6 mSv), 220 mA: 17.2 mSv (+/- 0.3 mSv), 330 mA: 25.7 mSv (+/- 0.3 mSv), 80 kVp/385 mA: 10.6 mSv (+/- 0.2 mSv). DLP effective doses for diagnostic runs were as follows: 110 mA: 8.7 mSv, 220 mA: 19 mSv, 330 mA: 28 mSv, 80 kVp/385 mA: 12 mSv. DLP effective doses exceeded MOSFET effective doses by 9.7-17.2%. Radiation doses for a 5-year-old during cardiac-gated CTA vary greatly depending on parameters. Organ doses can be high; the effective dose may reach 28.4 mSv. Further work, including determination of size-appropriate mA and image quality, is important before routine use of this technique in children.

  8. Use of in vivo counting measurements to estimate internal doses from (241)Am in workers from the Mayak production association.

    PubMed

    Sokolova, Alexandra B; Suslova, Klara G; Efimov, Alexander V; Miller, Scott C

    2014-08-01

    Comparisons between results of in vivo counting measurements of americium burden and results from radiochemical analyses of organ samples taken at autopsy of 11 cases of former Mayak workers were made. The in vivo counting measurements were performed 3-8 y before death. The best agreement between in vivo counting measurements for americium and autopsy data was observed for the skull. For lungs and liver, the ratios of burden measured by in vivo counting to those obtained from radiochemical analyses data ranged from 0.7-3.8, while those for the skull were from 1.0-1.1. There was a good correlation between the estimates of americium burden in the entire skeleton obtained from in vivo counting with those obtained from autopsy data. Specifically, the skeletal burden ratio, in vivo counting/autopsy, averaged 0.9 ± 0.1. The prior human americium model, D-Am2010, used in vivo counting measurements for americium in the skeleton to estimate the contents of americium and plutonium at death. The results using this model indicate that in vivo counting measurements of the skull can be used to estimate internal doses from americium in the Mayak workers. Additionally, these measurements may also be used to provide a qualitative assessment of internal doses from plutonium.

  9. EVALUATING QUANTITATIVE FORMULAS FOR DOSE-RESPONSE ASSESSMENT OF CHEMICAL MIXTURES

    EPA Science Inventory

    Risk assessment formulas are often distinguished from dose-response models by being rough but necessary. The evaluation of these rough formulas is described here, using the example of mixture risk assessment. Two conditions make the dose-response part of mixture risk assessment d...

  10. EVALUATING QUANTITATIVE FORMULAS FOR DOSE-RESPONSE ASSESSMENT OF CHEMICAL MIXTURES

    EPA Science Inventory

    Risk assessment formulas are often distinguished from dose-response models by being rough but necessary. The evaluation of these rough formulas is described here, using the example of mixture risk assessment. Two conditions make the dose-response part of mixture risk assessment d...

  11. The Concentration Of Tritium In Urine And Internal Radiation Dose Estimation Of PTNBR Radiation Workers

    SciTech Connect

    Tjahaja, Poppy Intan; Sukmabuana, Putu; Aisyah, Neneng Nur

    2010-12-23

    The operation of Triga 2000 reactor in Nuclear Technology Center for Materials and Radiometry (PTNBR BATAN) normally produce tritium radionuclide which is the activation product of deuterium atom in reactor primary cooling water. According to previous monitoring, tritium was detected with the concentration of 8.236{+-}0.677 kBq/L and 1.704{+-}0.046 Bq/L in the primary cooling water and in reactor hall air, respectively. The tritium in reactor hall air chronically can be inhaled by the workers. In this research, tritium content in radiation workers' urine was determined to estimate the internal radiation doses received by the workers. About 50-100 mL of urine samples were collected from 48 PTNBR workers that is classified as 24 radiation workers and 24 administration staffs as a control. Urine samples of 25 mL were then prepared by active charcoal and KMnO{sub 4} addition and followed with complete distillation. The 2 mL of distillate was added with 13 mL scintillator, shaked vigorously and remained in cool and dark condition for about 24 hours. The tritium in the samples was then measured using liquid scintillation counter (LSC) for 1 hour. From the measurement results it was obtained that the tritium concentration in the urine of radiation workers were in the range of not detected and 5.191 Bq/mL, whereas in the administration staffs the concentration were between not detected and 4.607 Bq/mL. Internally radiation doses were calculated using the tritium concentration data, and it was found the averages about 0.602 {mu}Sv/year and 0.532 {mu}Sv/year for radiation workers and administration staffs, respectively. The doses received by the workers were lower than that of the permissible doses from tritium, i.e. 40 {mu}Sv/year.

  12. International organizations, risk assessment and research-Why, what and how.

    PubMed

    Preston, R Julian

    2017-03-08

    The process of setting radiation protection standards requires the interaction of a number of international and national organizations that in turn require the input of scientific and regulatory experts. Bill Morgan served in an expert capacity for several of these organizations particularly for the application of radiation biology data to risk assessment. He brought great enthusiasm and dedication to these committee efforts. In fact, he really enjoyed this type of service. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), for example, provides comprehensive reviews of the input data for radiation risk assessments. In this context, they do not conduct risk assessments. In Europe, a research component of the risk assessment process is provided by the Multidisciplinary European Low Dose Initiative (MELODI). Specific issue areas are identified for which additional research can aid in reducing uncertainty in risk assessments. The International Commission on Radiological Protection (ICRP) uses these types of input data to develop nominal cancer risk estimates as input data for establishing dose limits for the public and workers. A similar regulatory role is provided in the US by the National Council on Radiation Protection and Measurements (NCRP). The NCRP Reports address the underlying principles for setting regulatory dose limits for the US public and workers; these differ to a limited extent from those of ICRP. The implementation of dose limits is conducted by individual countries but with significant guidance by the International Atomic Energy Agency (IAEA) through its Basic Safety Standards. The role of other national and international organizations are discussed in this same framework.

  13. Assessment of the benefits and impacts in the U.S. Nuclear Power Industry of hypothesized lower occupational dose limits

    SciTech Connect

    Andersen, R.L.; Schmitt, J.F.

    1995-03-01

    The International Commission on Radiological Protection and the National Council on Radiation Protection and Measurements have issued recommendations that would limit occupational exposure of individuals to doses lower than regulatory limits contained in the Nuclear Regulatory Commission`s 10 CFR Part 20, {open_quotes}Standards for Protection Against Radiation{close_quotes}. Because of this situation, there is interest in the potential benefits and impacts that would be associated with movement of the NRC regulatory limits toward the advisory bodies recommendations. The records of occupational worker doses in the U.S. commercial nuclear power industry show that the vast majority of these workers have doses that are significantly below the regulatory limit of 50 mSv (5 rem) per year. Some workers doses do approach the limits, however. This is most common in the case of specially skilled workers, especially those with skills utilized in support of plant outage work. Any consideration of the potential benefits and impacts of hypothesized lower dose limits must address these workers as an important input to the overall assessment. There are also, of course, many other areas in which the benefits and impacts must be evaluated. To prepare to provide valid, constructive input on this matter, the U.S. nuclear power industry is undertaking an assessment, facilitated by the Nuclear Energy Institute (NEI), of the potential benefits and impacts at its facilities associated with hypothesized lower occupational dose limits. Some preliminary results available to date from this assessment are provided.

  14. Occupational radiation dose to eyes from endoscopic retrograde cholangiopancreatography procedures in light of the revised eye lens dose limit from the International Commission on Radiological Protection.

    PubMed

    O'Connor, U; Gallagher, A; Malone, L; O'Reilly, G

    2013-02-01

    Endoscopic retrograde cholangiopancreatography (ERCP) is a common procedure that combines the use of X-ray fluoroscopy and endoscopy for examination of the bile duct. Published data on ERCP doses are limited, including staff eye dose from ERCP. Occupational eye doses are of particular interest now as the International Commission on Radiological Protection (ICRP) has recommended a reduction in the dose limit to the lens of the eye. The aim of this study was to measure occupational eye doses obtained from ERCP procedures. A new eye lens dosemeter (EYE-D(™), Radcard, Krakow, Poland) was used to measure the ERCP eye dose, H(p)(3), at two endoscopy departments in Ireland. A review of radiation protection practice at the two facilities was also carried out. The mean equivalent dose to the lens of the eye of a gastroenterologist is 0.01 mSv per ERCP procedure with an undercouch X-ray tube and 0.09 mSv per ERCP procedure with an overcouch X-ray tube. Staff eye dose normalised to patient kerma area product is also presented. Staff eye doses in ERCP have the potential to exceed the revised ICRP limit of 20 mSv per annum when an overcouch X-ray tube is used. The EYE-D dosemeter was found to be a convenient method for measuring lens dose. Eye doses in areas outside of radiology departments should be kept under review, particularly in light of the new ICRP eye dose limit. Occupational eye lens doses from ERCP procedures have been established using a new commercially available dedicated H(p)(3) dosemeter.

  15. Nuclear Decay Data in the MIRD (Medical Internal Radiation Dose) Format

    DOE Data Explorer

    MIRD is a database of evaluated nuclear decay data for over 2,100 radioactive nuclei. Data are extracted from ENSDF, processed by the program RadList, and used for medical internal radiation dose calculations. When using the MIRD interface, tables of nuclear and atomic radiations from nuclear decay and decay scheme drawings will be produced in the MIRD format from the Evaluated Nuclear Structure Data File (ENSDF) for the specified nuclide. Output may be either HTML-formatted tables and JPEG drawings, PostScript tables and drawings, or PDF tables and drawings.

  16. The Northern Marshall Islands radiological survey: Data and dose assessments

    SciTech Connect

    Robison, W.L.; Noshkin, V.E.; Conrado, C.L.

    1997-07-01

    Fallout from atmospheric nuclear tests, especially from those conducted at the Pacific Proving Grounds between 1946 and 1958, contaminated areas of the Northern Marshall Islands. A radiological survey at some Northern Marshall Islands was conducted from September through November 1978 to evaluate the extent of residual radioactive contamination. The atolls included in the Northern Marshall Islands Radiological Survey (NMIRS) were Likiep, Ailuk, Utirik, Wotho, Ujelang, Taka, Rongelap, Rongerik, Bikar, Ailinginae, and Mejit and Jemo Islands. The original test sites, Bikini and Enewetak Atolls, were also visited on the survey. An aerial survey was conducted to determine the external gamma exposure rate. Terrestrial (soil, food crops, animals, and native vegetation), cistern and well water samples, and marine (sediment, seawater, fish and clams) samples were collected to evaluate radionuclide concentrations in the atoll environment. Samples were processed and analyzed for {sup 137}Cs, {sup 90}Sr, {sup 239+240}Pu and {sup 241}Am. The dose from the ingestion pathway was calculated using the radionuclide concentration data and a diet model for local food, marine, and water consumption. The ingestion pathway contributes 70% to 90% of the estimated dose. Approximately 95% of the dose is from {sup 137}Cs accounts for about 10% to 30% of the dose. {sup 239+240}Pu and {sup 241}Am are the major contributors to dose via the inhalation pathway; however, inhalation accounts for only about 1% of the total estimated dose, based on surface soil levels and resuspension studies. All doses are computed for concentrations decay corrected to 1996. The maximum annual effective dose from manmade radionuclides at these atolls ranges from .02 mSv y{sup -1}. The background dose in the Marshall Islands is estimated to be 2.4 mSv y{sup -1} to 4.5 mSv y{sup -1}. The 50-y integral dose ranges from 0.5 to 65 mSv. 35 refs., 2 figs., 9 tabs.

  17. Assessment of International Work on Organizational Factors

    SciTech Connect

    Wall, Ian

    2002-06-01

    This report describes the concept of organizational factors and includes a consensus definition. It summarizes existing methods for assessing organizations from a safety culture perspective, for analyzing past incidents at plants to assess the role of safety culture, and for using such incident analysis to provide a database supporting organizational factors models. It describes existing methods that potentially could be extended to quantify organizational factors in a Probabilistic Safety Analysis. It concludes that no method is clearly superior for this purpose and recommends the organization of a workshop to clarify important issues prior to selecting a method.

  18. Assessment of Dose to the Nursing Infant from Radionuclides in Breast Milk

    SciTech Connect

    Leggett, Richard Wayne; Eckerman, Keith F

    2010-03-01

    A computer software package was developed to predict tissue doses to an infant due to intake of radionuclides in breast milk based on bioassay measurements and exposure data for the mother. The package is intended mainly to aid in decisions regarding the safety of breast feeding by a mother who has been acutely exposed to a radionuclide during lactation or pregnancy, but it may be applied to previous intakes during the mother s adult life. The package includes biokinetic and dosimetric information needed to address intake of Co-60, Sr-90, Cs-134, Cs-137, Ir-192, Pu-238, Pu-239, Am-241, or Cf-252 by the mother. It has been designed so that the library of biokinetic and dosimetric files can be expanded to address a more comprehensive set of radionuclides without modifying the basic computational module. The methods and models build on the approach used in Publication 95 of the International Commission on Radiological Protection (ICRP 2004), Doses to Infants from Ingestion of Radionuclides in Mothers Milk . The software package allows input of case-specific information or judgments such as chemical form or particle size of an inhaled aerosol. The package is expected to be more suitable than ICRP Publication 95 for dose assessment for real events or realistic planning scenarios in which measurements of the mother s excretion or body burden are available.

  19. Standards-Based Assessment for Principal Interns

    ERIC Educational Resources Information Center

    Koonce, Glenn; Causey, Ralph

    2011-01-01

    The Framework for School Leaders, an architecture derived from the Interstate School Leaders Licensure Consortium (ISLLC) Standards, is utilized in the design of the Principal Internship Mentor's Assessment (PIMA). PIMA outcomes are reported for average scores for each standard and investigated as a measure of ISLLC Standards achievement and for…

  20. KREAM: Korean Radiation Exposure Assessment Model for Aviation Route Dose

    NASA Astrophysics Data System (ADS)

    Hwang, J.; Dokgo, K.; Choi, E. J.; Kim, K. C.; Kim, H. P.; Cho, K. S. F.

    2014-12-01

    Since Korean Air has begun to use the polar route from Seoul/ICN airport to New York/JFK airport on August 2006, there are explosive needs for the estimation and prediction against cosmic radiation exposure for Korean aircrew and passengers in South Korea from public. To keep pace with those needs of public, Korean government made the law on safety standards and managements of cosmic radiation for the flight attendants and the pilots in 2013. And we have begun to develop our own Korean Radiation Exposure Assessment Model (KREAM) for aviation route dose since last year funded by Korea Meteorological Administration (KMA). GEANT4 model and NRLMSIS 00 model are used for calculation of the energetic particles' transport in the atmosphere and for obtaining the background atmospheric neutral densities depending on altitude. For prediction the radiation exposure in many routes depending on the various space weather effects, we constructed a database from pre-arranged simulations using all possible combinations of R, S, and G, which are the space weather effect scales provided by the National Oceanic and Atmospheric Administration (NOAA). To get the solar energetic particles' spectrum at the 100 km altitude which we set as a top of the atmospheric layers in the KREAM, we use ACE and GOES satellites' proton flux observations. We compare the results between KREAM and the other cosmic radiation estimation programs such as CARI-6M which is provided by the Federal Aviation Agency (FAA). We also validate KREAM's results by comparison with the measurement from Liulin-6K LET spectrometer onboard Korean commercial flights and Korean Air Force reconnaissance flights.

  1. Toxicity from repeated doses of acetaminophen in children: Assessment of causality and dose in reported cases

    PubMed Central

    Heard, Kennon; Bui, Alison; Mlynarchek, Sara L; Green, Jody L.; Bond, G. Randall; Clark, Richard F.; Kozer, Eran; Koff, Raymond S.; Dart, Richard C.

    2012-01-01

    Background Liver injury has been reported in children treated with repeated doses of acetaminophen. The objective of this study is to identify and validate reports of liver injury or death in children younger than 6 years of age following repeated therapeutic doses of acetaminophen. Methods We reviewed United States (US) Poison Center data, peer-reviewed literature, US FDA Adverse event reports and US Manufacturer safety reports describing adverse effects following acetaminophen administration. Reports that described hepatic abnormalities (description of liver injury or abnormal laboratory testing) or death following administration to children younger than 6 years of age were included. The identified reports were double abstracted and then reviewed by an expert panel to determine if the hepatic injury was related to acetaminophen, and whether the dose of acetaminophen was therapeutic (≤75 mg/kg) or supra-therapeutic. Results Our search yielded 2531 reports of adverse events associated with acetaminophen use. From these cases, we identified 76 cases of hepatic injury and 26 deaths associated with repeated acetaminophen administration. There were 6 cases of hepatic abnormalities and no deaths associated with what our panel determined to be therapeutic doses. A large proportion of cases could not be fully evaluated due to incomplete case reporting. Conclusions While we identified numerous examples of liver injury and death following repeated doses of acetaminophen, all of the deaths and all but 6 cases of hepatic abnormalities involved doses greater than 75 mg/kg/day. This study suggests that the doses of less than 75 mg/kg/day of acetaminophen are safe for children younger than 6 years of age. PMID:22407198

  2. Toxicity from repeated doses of acetaminophen in children: assessment of causality and dose in reported cases.

    PubMed

    Heard, Kennon; Bui, Alison; Mlynarchek, Sara L; Green, Jody L; Bond, G Randall; Clark, Richard F; Kozer, Eran; Koff, Raymond S; Dart, Richard C

    2014-01-01

    Liver injury has been reported in children treated with repeated doses of acetaminophen. The objective of this study was to identify and validate reports of liver injury or death in children younger than 6 years who were administered repeated therapeutic doses of acetaminophen. We reviewed US Poison Center data, peer-reviewed literature, US Food and Drug Administration Adverse Event Reports, and US Manufacturer Safety Reports describing adverse effects after acetaminophen administration. Reports that described hepatic abnormalities (description of liver injury or abnormal laboratory testing) or death after acetaminophen administration to children younger than 6 years were included. The identified reports were double abstracted and then reviewed by an expert panel to determine if the hepatic injury was related to acetaminophen and whether the dose of acetaminophen was therapeutic (≤75 mg/kg) or supratherapeutic. Our search yielded 2531 reports of adverse events associated with acetaminophen use. From these cases, we identified 76 cases of hepatic injury and 26 deaths associated with repeated acetaminophen administration. There were 6 cases of hepatic abnormalities and no deaths associated with what our panel determined to be therapeutic doses. A large proportion of cases could not be fully evaluated due to incomplete case reporting. Although we identified numerous examples of liver injury and death after repeated doses of acetaminophen, all the deaths and all but 6 cases of hepatic abnormalities involved doses more than 75 mg/kg per day. This study suggests that the doses of less than 75 mg/kg per day of acetaminophen are safe for children younger than 6 years.

  3. Exposure versus internal dose: Respiratory tract deposition modeling of inhaled asbestos fibers in rats and humans (Presentation Poster)

    EPA Science Inventory

    Exposure to asbestos is associated with respiratory diseases, including asbestosis, lung cancer and mesothelioma. Internal fiber dose depends on fiber inhalability and orientation, fiber density, length and width, and various deposition mechanisms (DM). Species-specific param...

  4. Exposure versus internal dose: Respiratory tract deposition modeling of inhaled asbestos fibers in rats and humans (Presentation Poster)

    EPA Science Inventory

    Exposure to asbestos is associated with respiratory diseases, including asbestosis, lung cancer and mesothelioma. Internal fiber dose depends on fiber inhalability and orientation, fiber density, length and width, and various deposition mechanisms (DM). Species-specific param...

  5. The chernobyl accident 20 years on: an assessment of the health consequences and the international response.

    PubMed

    Baverstock, Keith; Williams, Dillwyn

    2006-09-01

    The Chernobyl accident in 1986 caused widespread radioactive contamination and enormous concern. Twenty years later, the World Health Organization and the International Atomic Energy Authority issued a generally reassuring statement about the consequences. Accurate assessment of the consequences is important to the current debate on nuclear power. Our objectives in this study were to evaluate the health impact of the Chernobyl accident, assess the international response to the accident, and consider how to improve responses to future accidents. So far, radiation to the thyroid from radioisotopes of iodine has caused several thousand cases of thyroid cancer but very few deaths ; exposed children were most susceptible. The focus on thyroid cancer has diverted attention from possible nonthyroid effects, such as mini-satellite instability, which is potentially important. The international response to the accident was inadequate and uncoordinated, and has been unjustifiably reassuring. Accurate assessment of Chernobyl's future health effects is not currently possible in the light of dose uncertainties, current debates over radiation actions, and the lessons from the late consequences of atomic bomb exposure. Because of the uncertainties over the dose from and the consequences of the Chernobyl accident, it is essential that investigations of its effects should be broadened and supported for the long term. Because of the problems with the international response to Chernobyl, the United Nations should initiate an independent review of the actions and assignments of the agencies concerned, with recommendations for dealing with future international-scale accidents. These should involve independent scientists and ensure cooperation rather than rivalry.

  6. Dose assessment of 2% chlorhexidine acetate for canine superficial pyoderma.

    PubMed

    Murayama, Nobuo; Terada, Yuri; Okuaki, Mio; Nagata, Masahiko

    2011-10-01

    The dose of 2% chlorhexidine acetate (2CA; Nolvasan(®) Surgical Scrub; Fort Dodge Animal Health, Fort Dodge, IA, USA) for canine superficial pyoderma was evaluated. The first trial compared three doses (group 1, 57 mL/m(2) body surface area; group 2, 29 mL/m(2) body surface area; and group 3, 19 mL/m(2) body surface area) in a randomized, double-blind, controlled fashion. Twenty-seven dogs with superficial pyoderma were treated with 2CA at the allocated doses every 2 days for 1 week. The owners and investigators subjectively evaluated the dogs, and investigators scored skin lesions, including erythema, papules/pustules, alopecia and scales, on a 0-4 scale. There were no significant differences in response between the treatment groups. The second trial established a practical dose-measuring method for 2CA. Sixty-eight owners were asked to apply 2CA on their palm in an amount corresponding to a Japanese ¥500 coin, 26.5 mm in diameter. This yielded an average dose of 0.90±0.40 mL. Mathematically, the doses used in groups 1, 2 and 3 can be represented as one coin per approximately one-, two- and three-hand-sized lesions, respectively. The results therefore suggest that owners instructed to apply one coin of the product per two-hand-sized areas of superficial pyoderma would use the range of doses evaluated in this trial.

  7. Development of wireless communication system in real-time internal radiation dose measurement system using magnetic field

    NASA Astrophysics Data System (ADS)

    Sato, Fumihiro; Shinohe, Kohta; Takura, Tetsuya; Matsuki, Hidetoshi; Yamada, Syogo; Sato, Tadakuni

    2009-04-01

    In radiation therapy, excessive radiation occurs because the actual delivered dose to the tumor is unknown. To overcome this problem, we need a system in which the delivered dose is measured inside the body, and the dose data are transmitted from the inside to the outside of the body. In this study, a wireless communication system, using magnetic fields was studied, and an internal circuit for obtaining radiation dose data from an x-ray detector was examined. As a result, a communication distance of 200 mm was obtained. An internal circuit was developed, and a signal transmission experiment was performed using the wireless communication system. As a result, the radiation dose data from an x-ray detector was transmitted over a communication distance of 200 mm, and the delivered dose was determined from the received signal.

  8. Development of wireless communication system in real-time internal radiation dose measurement system using magnetic field

    SciTech Connect

    Sato, Fumihiro; Shinohe, Kohta; Takura, Tetsuya; Matsuki, Hidetoshi; Yamada, Syogo; Sato, Tadakuni

    2009-04-01

    In radiation therapy, excessive radiation occurs because the actual delivered dose to the tumor is unknown. To overcome this problem, we need a system in which the delivered dose is measured inside the body, and the dose data are transmitted from the inside to the outside of the body. In this study, a wireless communication system, using magnetic fields was studied, and an internal circuit for obtaining radiation dose data from an x-ray detector was examined. As a result, a communication distance of 200 mm was obtained. An internal circuit was developed, and a signal transmission experiment was performed using the wireless communication system. As a result, the radiation dose data from an x-ray detector was transmitted over a communication distance of 200 mm, and the delivered dose was determined from the received signal.

  9. Radiation Dose-Response Relationships and Risk Assessment

    SciTech Connect

    Strom, Daniel J.

    2005-07-05

    The notion of a dose-response relationship was probably invented shortly after the discovery of poisons, the invention of alcoholic beverages, and the bringing of fire into a confined space in the forgotten depths of ancient prehistory. The amount of poison or medicine ingested can easily be observed to affect the behavior, health, or sickness outcome. Threshold effects, such as death, could be easily understood for intoxicants, medicine, and poisons. As Paracelsus (1493-1541), the 'father' of modern toxicology said, 'It is the dose that makes the poison.' Perhaps less obvious is the fact that implicit in such dose-response relationships is also the notion of dose rate. Usually, the dose is administered fairly acutely, in a single injection, pill, or swallow; a few puffs on a pipe; or a meal of eating or drinking. The same amount of intoxicants, medicine, or poisons administered over a week or month might have little or no observable effect. Thus, before the discovery of ionizing radiation in the late 19th century, toxicology ('the science of poisons') and pharmacology had deeply ingrained notions of dose-response relationships. This chapter demonstrates that the notion of a dose-response relationship for ionizing radiation is hopelessly simplistic from a scientific standpoint. While useful from a policy or regulatory standpoint, dose-response relationships cannot possibly convey enough information to describe the problem from a quantitative view of radiation biology, nor can they address societal values. Three sections of this chapter address the concepts, observations, and theories that contribute to the scientific input to the practice of managing risks from exposure to ionizing radiation. The presentation begins with irradiation regimes, followed by responses to high and low doses of ionizing radiation, and a discussion of how all of this can inform radiation risk management. The knowledge that is really needed for prediction of individual risk is presented

  10. INTEGRATED RISK ASSESSMENT - RESULTS OF AN INTERNATIONAL WORKSHOP

    EPA Science Inventory

    The UNEP/ILO/WHO International Programme on Chemical Safety (IPCS), the Organization for Economic Cooperation and Development (OECD), and the U.S. Environmental Protection Agency (USEPA) have developed a collaborative partnership to foster integration of assessment approaches to ...

  11. INTEGRATED RISK ASSESSMENT - RESULTS OF AN INTERNATIONAL WORKSHOP

    EPA Science Inventory

    The UNEP/ILO/WHO International Programme on Chemical Safety (IPCS), the Organization for Economic Cooperation and Development (OECD), and the U.S. Environmental Protection Agency (USEPA) have developed a collaborative partnership to foster integration of assessment approaches to ...

  12. Needs Assessment of International Students at Eastern Oregon State College.

    ERIC Educational Resources Information Center

    Eid, Mamoud Taha; Jordan-Domschot, Theresa

    The purpose of the research project was to assess the needs, satisfaction, and concerns of international students attending Eastern Oregon State College. The international student population consisted of students from Micronesia, Netherlands, Somalia, Saudi Arabia, Jordan, Iran, Japan, Thailand, Zimbabwe, Belgium, Canada, Nigeria, China,…

  13. International Civic and Citizenship Education Study: Assessment Framework

    ERIC Educational Resources Information Center

    Schulz, Wolfram; Fraillon, Julian; Ainley, John; Losito, Bruno; Kerr, David

    2008-01-01

    This document outlines the framework and assessment design for the International Civic and Citizenship Education Study (ICCS) sponsored by the International Association for the Evaluation of Educational Achievement (IEA). Over the past 50 years, IEA has conducted comparative research studies focusing on educational policies, practices, and…

  14. Internal Assessment as a First Step in Strategic Planning.

    ERIC Educational Resources Information Center

    Morris, Pamela; Tuthill, Suzanne

    The internal assessment process described in this report was initiated at the Wilmington/Stanton Campus of Delaware Technical and Community College in 1985 in preparation for a reaccreditation study and in response to a climate of rapid internal and external change. Following introductory comments on the campus, the purpose of the internal…

  15. Needs Assessment of International Students at Eastern Oregon State College.

    ERIC Educational Resources Information Center

    Eid, Mamoud Taha; Jordan-Domschot, Theresa

    The purpose of the research project was to assess the needs, satisfaction, and concerns of international students attending Eastern Oregon State College. The international student population consisted of students from Micronesia, Netherlands, Somalia, Saudi Arabia, Jordan, Iran, Japan, Thailand, Zimbabwe, Belgium, Canada, Nigeria, China,…

  16. 42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

  17. 42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

  18. 42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

  19. 42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

  20. 42 CFR 82.18 - How will NIOSH calculate internal dose to the primary cancer site(s)?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... primary cancer site(s)? 82.18 Section 82.18 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND... Dose Reconstruction Process § 82.18 How will NIOSH calculate internal dose to the primary cancer site(s... cancer covered by a claim is in a tissue not covered by existing ICRP models, NIOSH will use the ICRP...

  1. Assessment of Lower Doses of Intravitreous Bevacizumab for Retinopathy of Prematurity: A Phase 1 Dosing Study.

    PubMed

    Wallace, David K; Kraker, Raymond T; Freedman, Sharon F; Crouch, Eric R; Hutchinson, Amy K; Bhatt, Amit R; Rogers, David L; Yang, Michael B; Haider, Kathryn M; VanderVeen, Deborah K; Siatkowski, R Michael; Dean, Trevano W; Beck, Roy W; Repka, Michael X; Smith, Lois E; Good, William V; Hartnett, Mary Elizabeth; Kong, Lingkun; Holmes, Jonathan M

    2017-06-01

    Intravitreous bevacizumab (0.25 to 0.625 mg) is increasingly used to treat type 1 retinopathy of prematurity (ROP), but there remain concerns about systemic toxicity. A much lower dose may be effective while reducing systemic risk. To find a dose of intravitreous bevacizumab that was lower than previously used for severe ROP, was effective in this study, and could be tested in future larger studies. Between May 2015 and September 2016, 61 premature infants with type 1 ROP in 1 or both eyes were enrolled in a masked, multicenter, phase 1 dose de-escalation study. One eye of 10 to 14 infants received 0.25 mg of intravitreous bevacizumab. If successful, the dose was reduced for the next group of infants (to 0.125 mg, then 0.063 mg, and finally 0.031 mg). Diluted bevacizumab was delivered using 300 µL syringes with 5/16-inch, 30-gauge fixed needles. Bevacizumab injections at 0.25 mg, 0.125 mg, 0.063 mg, and 0.031 mg. Success was defined as improvement in preinjection plus disease or zone I stage 3 ROP by 5 days after injection or sooner, and no recurrence of type 1 ROP or severe neovascularization requiring additional treatment within 4 weeks. Fifty-eight of 61 enrolled infants had 4-week outcomes completed; mean birth weight was 709 g and mean gestational age was 24.9 weeks. Success was achieved in 11 of 11 eyes at 0.25 mg, 14 of 14 eyes at 0.125 mg, 21 of 24 eyes at 0.063 mg, and 9 of 9 eyes at 0.031 mg. A dose of bevacizumab as low as 0.031 mg was effective in 9 of 9 eyes in this phase 1 study and warrants further investigation. Identifying a lower effective dose of bevacizumab may reduce the risk for neurodevelopmental disability or detrimental effects on other organs.

  2. Radiological dose assessments of atolls in the Northern Marshall Islands

    SciTech Connect

    Robison, W.L.

    1983-11-01

    Methods and models used to estimate the radiation doses to a returning population of the atolls in the Marshall Islands are presented. In this environment natural processes have acted on source-term radionuclides for nearly 30 years. The data bases developed for the models, and the results of the radiological dose analyses at the various atolls are described. The major radionuclides in order of their contribution to the total estimated doses were /sup 137/Cs, /sup 90/Sr, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 60/Co. Exposure pathways in order of their contribution to the estimated doses were: terrestrial food chain, external ..gamma.., marine food chain, inhalation, and cistern water and ground water. 56 references, 13 figures, 16 tables.

  3. Dose assessment of an accidental exposure at the IPNS

    SciTech Connect

    Campos Torres, M.M.

    1995-02-01

    Seven different methods were used to estimate the dose rate to a female worker who was accidentally exposed in the neutron PHOENIX beamline at the IPNS. Theoretical and measured entrance dose ranged from 550 mrem/min to 2850 mrem/min. Theoretical estimates were based on a Monte Carlo simulation of a spectrum provided by IPNS (Crawford Spectrum). Dose measurements were made with TLDs on phantoms and with ionization chambers in a water phantom. Estimates of the whole body total effective dose equivalent (TEDE) rate ranged from 5.2 mrem/min to 840 mrem/min. Assumed and measured quality factors ranged from 2.6 to 11.8. Cytogenetic analyses of blood samples detected no positive exposure. The recommended TEDE rate was 158 mrem/min. The TEDE was 750 mrem.

  4. Dose assessment of an accidental exposure at IPNS

    SciTech Connect

    Torres, M.M.C.

    1996-05-01

    Seven different methods were used to estimate the dose rate to a female worker who was accidentally exposed in the neutron PHOENIX beamline at the IPNS. Theoretical and measured entrance dose rates ranged from 550 mrem/min to 2,850 mrem/min. Theoretical estimates were based on a Monte Carlo simulation of a spectrum provided by IPNS (Crawford Spectrum). Dose measurements were made with TLDs on phantoms and with ionization chambers in a water phantom. Estimates of the whole body total effective dose equivalent (TEDE) rate ranged from 5.2 mrem/min to 840 mrem/min. Assumed and measured quality factors ranged from 2.6 to 11.8. Cytogenic analyses of blood samples detected no positive exposure. The recommended TEDE rate was 158 mrem/min. The TEDE was 750 mrem.

  5. The Northern Marshall Islands Radiological Survey: data and dose assessments.

    PubMed

    Robison, W L; Noshkin, V E; Conrado, C L; Eagle, R J; Brunk, J L; Jokela, T A; Mount, M E; Phillips, W A; Stoker, A C; Stuart, M L; Wong, K M

    1997-07-01

    Fallout from atmospheric nuclear tests, especially from those conducted at the Pacific Proving Grounds between 1946 and 1958, contaminated areas of the Northern Marshall Islands. A radiological survey at some Northern Marshall Islands was conducted from September through November 1978 to evaluate the extent of residual radioactive contamination. The atolls included in the Northern Marshall Islands Radiological Survey (NMIRS) were Likiep, Ailuk, Utirik, Wotho, Ujelang, Taka, Rongelap, Rongerik, Bikar, Ailinginae, and Mejit and Jemo Islands. The original test sites, Bikini and Enewetak Atolls, were also visited on the survey. An aerial survey was conducted to determine the external gamma exposure rate. Terrestrial (soil, food crops, animals, and native vegetation), cistern and well water samples, and marine (sediment, seawater, fish and clams) samples were collected to evaluate radionuclide concentrations in the atoll environment. Samples were processed and analyzed for 137Cs, 90Sr, 239+240Pu and 241Am. The dose from the ingestion pathway was calculated using the radionuclide concentration data and a diet model for local food, marine, and water consumption. The ingestion pathway contributes 70% to 90% of the estimated dose. Approximately 95% of the dose is from 137Cs. 90Sr is the second most significant radionuclide via ingestion. External gamma exposure from 137Cs accounts for about 10% to 30% of the dose. 239+240Pu and 241Am are the major contributors to dose via the inhalation pathway; however, inhalation accounts for only about 1% of the total estimated dose, based on surface soil levels and resuspension studies. All doses are computed for concentrations decay corrected to 1996. The maximum annual effective dose from manmade radionuclides at these atolls ranges from .02 mSv y(-1) to 2.1 mSv y(-1). The background dose in the Marshall Islands is estimated to be 2.4 mSv y(-1). The combined dose from both background and bomb related radionuclides ranges from slightly

  6. Estimating dose rates to organs as a function of age following internal exposure to radionuclides

    SciTech Connect

    Leggett, R.W.; Eckerman, K.F.; Dunning, D.E. Jr.; Cristy, M.; Crawford-Brown, D.J.; Williams, L.R.

    1984-03-01

    The AGEDOS methodology allows estimates of dose rates, as a function of age, to radiosensitive organs and tissues in the human body at arbitrary times during or after internal exposure to radioactive material. Presently there are few, if any, radionuclides for which sufficient metabolic information is available to allow full use of all features of the methodology. The intention has been to construct the methodology so that optimal information can be gained from a mixture of the limited amount of age-dependent, nuclide-specific data and the generally plentiful age-dependent physiological data now available. Moreover, an effort has been made to design the methodology so that constantly accumulating metabolic information can be incorporated with minimal alterations in the AGEDOS computer code. Some preliminary analyses performed by the authors, using the AGEDOS code in conjunction with age-dependent risk factors developed from the A-bomb survivor data and other studies, has indicated that the doses and subsequent risks of eventually experiencing radiogenic cancers may vary substantially with age for some exposure scenarios and may be relatively invariant with age for other scenarios. We believe that the AGEDOS methodology provides a convenient and efficient means for performing the internal dosimetry.

  7. An overview of internal dose estimation using whole-body counters in Fukushima Prefecture.

    PubMed

    Miyazaki, Makoto; Ohtsuru, Akira; Ishikawa, Tetsuo

    2014-01-01

    A large amount of radioactive cesium was released by the Fukushima Daiichi Nuclear Power Plant accident following the Great East Japan Earthquake. Due to the increasing concerns about internal exposure, more than 50 whole-body counters (WBCs) have been installed at various locations in Fukushima Prefecture. A study on around 10,000 subjects in the early stage after the accident revealed that very few received a committed effective dose of more than 0.3 mSv for subjects (age >13 years old). Another study on WBC results for one hospital showed that the ratio of cesium-positive was 1.0% among all the subjects. Assuming a constant daily intake, the detection limit of 300 Bq/body for a typical WBC corresponds to an effective dose of 21 μSv/y even for a subject of age up to 10. It was also seen out that the subjects with a significant amount of body cesium are likely to regularly eat wild products, which they harvested or caught themselves without testing for radioactive cesium. These study findings suggested that the internal exposure for most of the residents was controlled at a very low level. Future tasks regarding WBC measurements are how to personally explain the WBC results to each subject and how to disclose the statistically processed WBC data to the general public.

  8. Effect of Gold Nanoparticles on Prostate Dose Distribution under Ir-192 Internal and 18 MV External Radiotherapy Procedures Using Gel Dosimetry and Monte Carlo Method

    PubMed Central

    Khosravi, H.; Hashemi, B.; Mahdavi, S. R.; Hejazi, P.

    2015-01-01

    Background Gel polymers are considered as new dosimeters for determining radiotherapy dose distribution in three dimensions. Objective The ability of a new formulation of MAGIC-f polymer gel was assessed by experimental measurement and Monte Carlo (MC) method for studying the effect of gold nanoparticles (GNPs) in prostate dose distributions under the internal Ir-192 and external 18MV radiotherapy practices. Method A Plexiglas phantom was made representing human pelvis. The GNP shaving 15 nm in diameter and 0.1 mM concentration were synthesized using chemical reduction method. Then, a new formulation of MAGIC-f gel was synthesized. The fabricated gel was poured in the tubes located at the prostate (with and without the GNPs) and bladder locations of the phantom. The phantom was irradiated to an Ir-192 source and 18 MV beam of a Varian linac separately based on common radiotherapy procedures used for prostate cancer. After 24 hours, the irradiated gels were read using a Siemens 1.5 Tesla MRI scanner. The absolute doses at the reference points and isodose curves resulted from the experimental measurement of the gels and MC simulations following the internal and external radiotherapy practices were compared. Results The mean absorbed doses measured with the gel in the presence of the GNPs in prostate were 15% and 8 % higher than the corresponding values without the GNPs under the internal and external radiation therapies, respectively. MC simulations also indicated a dose increase of 14 % and 7 % due to presence of the GNPs, for the same experimental internal and external radiotherapy practices, respectively. Conclusion There was a good agreement between the dose enhancement factors (DEFs) estimated with MC simulations and experiment gel measurements due to the GNPs. The results indicated that the polymer gel dosimetry method as developed and used in this study, can be recommended as a reliable method for investigating the DEF of GNPs in internal and external

  9. Warfarin Dosing and Time Required to Reach Therapeutic International Normalized Ratio in Patients with Hypercoagulable Conditions

    PubMed Central

    Kahlon, Pushpinderdeep; Nabi, Shahzaib; Arshad, Adeel; Jabbar, Absia; Haythem, Ali

    2016-01-01

    Objective: The purpose of this study was to analyze the difference in duration of anticoagulation and dose of warfarin required to reach a therapeutic international normalized ratio [(INR) of 2 to 3] in patients with hypercoagulable conditions as compared to controls. To our knowledge, this study is the first in the literature to delineate such a difference. Materials and Methods: A retrospective chart review was performed in a tertiary care hospital. The total study population was 622. Cases (n=125) were patients with a diagnosis of a hypercoagulable syndrome who developed venous thromboembolism. Controls (n=497) were patients with a diagnosis of venous thromboembolism in the absence of a hypercoagulable syndrome and were matched for age, sex, and race. Results: The total dose of warfarin required to reach therapeutic INR in cases was higher (50.7±17.6 mg) as compared to controls (41.2±17.7 mg). The total number of days required to reach therapeutic INR in cases was 8.9±3.5 days as compared to controls (6.8±2.9 days). Both of these differences were statistically significant (p<0.001). Conclusion: Patients with hypercoagulable conditions require approximately 10 mg of additional total warfarin dose and also require, on average, 2 extra days to reach therapeutic INR as compared to controls. PMID:27093959

  10. 241Am Ingrowth and Its Effect on Internal Dose

    SciTech Connect

    Konzen, Kevin

    2016-07-01

    Generally, plutonium has been manufactured to support commercial and military applications involving heat sources, weapons and reactor fuel. This work focuses on three typical plutonium mixtures, while observing the potential of 241Am ingrowth and its effect on internal dose. The term “ingrowth” is used to describe 241Am production due solely from the decay of 241Pu as part of a plutonium mixture, where it is initially absent or present in a smaller quantity. Dose calculation models do not account for 241Am ingrowth unless the 241Pu quantity is specified. This work suggested that 241Am ingrowth be considered in bioassay analysis when there is a potential of a 10% increase to the individual’s committed effective dose. It was determined that plutonium fuel mixtures, initially absent of 241Am, would likely exceed 10% for typical reactor grade fuel aged less than 30 years; however, heat source grade and aged weapons grade fuel would normally fall below this threshold. In conclusion, although this work addresses typical plutonium mixtures following separation, it may be extended to irradiated commercial uranium fuel and is expected to be a concern in the recycling of spent fuel.

  11. Warfarin Dosing and Time Required to Reach Therapeutic International Normalized Ratio in Patients with Hypercoagulable Conditions.

    PubMed

    Kahlon, Pushpinderdeep; Nabi, Shahzaib; Arshad, Adeel; Jabbar, Absia; Haythem, Ali

    2016-12-01

    The purpose of this study was to analyze the difference in duration of anticoagulation and dose of warfarin required to reach a therapeutic international normalized ratio [(INR) of 2 to 3] in patients with hypercoagulable conditions as compared to controls. To our knowledge, this study is the first in the literature to delineate such a difference. A retrospective chart review was performed in a tertiary care hospital. The total study population was 622. Cases (n=125) were patients with a diagnosis of a hypercoagulable syndrome who developed venous thromboembolism. Controls (n=497) were patients with a diagnosis of venous thromboembolism in the absence of a hypercoagulable syndrome and were matched for age, sex, and race. The total dose of warfarin required to reach therapeutic INR in cases was higher (50.7±17.6 mg) as compared to controls (41.2±17.7 mg). The total number of days required to reach therapeutic INR in cases was 8.9±3.5 days as compared to controls (6.8±2.9 days). Both of these differences were statistically significant (p<0.001). Patients with hypercoagulable conditions require approximately 10 mg of additional total warfarin dose and also require, on average, 2 extra days to reach therapeutic INR as compared to controls.

  12. The Radiobiological Basis for Improvements in Radiotherapy and Low Dose Risk Assessment

    SciTech Connect

    Hei, Tom K

    2009-12-09

    Overall Goal: This conference grant was proposed to organize and host an international conference at Columbia University in New York to critically assess the cellular and molecular signaling events and tissue response following radiation damage. The conference would also serve as a venue to play tribute to the more than forty years contributions made by Professor Eric J. Hall to the radiation biology field. The goals of the meeting were to examine tumor hypoxia and sensitizer development; recent advances made in clinical radiotherapy; addressed several low dose phenomena, including genomic instability and bystander effects that are important in radiation risk assessment. Study and Results: The symposium was held on October 13th and 14th, 2008 at the Alfred Lerner Hall in the Morningside campus of Columbia University. The symposium, entitled “From Beans to Genes: A Forty Year Odyssey in Radiation Biology” was attended by more than 120 faculty, scientists, clinicians, fellows and students. The symposium, spanned over a day and a half, covered four scientific themes. These included tumor hypoxia and radiosensitizers; low dose radiation response; radiation biology in the practice of radiotherapy, and radiation hazard in space and genetic predisposition to cancer. The program of the symposium is as follow:

  13. [Assessment of cognitive functions in internal medicine].

    PubMed

    Capron, J

    2015-12-01

    The evaluation of cognitive functions can be performed using two approaches: a quantitative one, based on screening tools; a qualitative one, based on the examination of specific cognitive functions. The quantitative approach offers a pragmatic process: to screen rapidly for a cognitive dysfunction that may require assistance or treatments. We will present three screening tools and their diagnostic value: the clock test, the Mini Mental State Examination and the Montreal Cognitive Assessment. They help select patients who require a more detailed examination to precisely diagnose their cognitive dysfunction. We propose a way to perform a detailed cognitive examination at the bedside, including the examination of alertness, attention, memory, language, frontal functions, praxis and hemi-neglect. This simple examination indicates the location of the cerebral lesion and sometimes suggests the underlying disease. Copyright © 2015. Published by Elsevier SAS.

  14. Radiological dose assessments in the northern Marshall Islands (1989--1991)

    SciTech Connect

    Sun, L.C.; Meinhold, C.B.; Moorthy, A.R.; Clinton, J.H.; Kaplan, E.

    1992-01-01

    The present Brookhaven National Laboratory (BNL) Marshall Islands Radiological Safety Program (MIRSP) began in 1987 with funding from the US Department of Energy (DOE). The objectives of the MIRSP are to determine the radionuclides present in the bodies of those people potentially exposed to residual radionuclide from weapon tests and fallout, and to assess their present and lifetime dose from external and internal sources. Field bioassay missions involving whole body counting (WBC) and urine sample collection have, therefore, been important components of the program. WBC is used to measure {gamma}-emitters, such as {sup 40}K, {sup 60}Co and {sup 137}Cs, present in individuals. Urine samples are used to measure {alpha} and {beta}-emitting nuclides, such as {sup 239}Pu and {sup 90}Sr, that are undetectable by WBC routine methods.

  15. Radiological dose assessments in the northern Marshall Islands (1989--1991)

    SciTech Connect

    Sun, L.C.; Meinhold, C.B.; Moorthy, A.R.; Clinton, J.H.; Kaplan, E.

    1992-01-01

    The present Brookhaven National Laboratory (BNL) Marshall Islands Radiological Safety Program (MIRSP) began in 1987 with funding from the US Department of Energy (DOE). The objectives of the MIRSP are to determine the radionuclides present in the bodies of those people potentially exposed to residual radionuclide from weapon tests and fallout, and to assess their present and lifetime dose from external and internal sources. Field bioassay missions involving whole body counting (WBC) and urine sample collection have, therefore, been important components of the program. WBC is used to measure {gamma}-emitters, such as {sup 40}K, {sup 60}Co and {sup 137}Cs, present in individuals. Urine samples are used to measure {alpha} and {beta}-emitting nuclides, such as {sup 239}Pu and {sup 90}Sr, that are undetectable by WBC routine methods.

  16. Dose assessment according to changes in algorithm in cardiac CT

    NASA Astrophysics Data System (ADS)

    Jang, H. C.; Cho, J. H.; Lee, H. K.; Hong, I. S.; Cho, M. S.; Park, C. S.; Lee, S. Y.; Dong, K. R.; Goo, E. H.; Chung, W. K.; Ryu, Y. H.; Lim, C. S.

    2012-06-01

    The principal objective of this study was to determine the effects of the application of the adaptive statistical iterative reconstruction (ASIR) technique in combination with another two factors (body mass index (BMI) and tube potential) on radiation dose in cardiac computed tomography (CT). For quantitative analysis, regions of interest were positioned on the central region of the great coronary artery, the right coronary artery, and the left anterior descending artery, after which the means and standard deviations of measured CT numbers were obtained. For qualitative analysis, images taken from the major coronary arteries (right coronary, left anterior descending, and left circumflex) were graded on a scale of 1-5, with 5 indicating the best image quality. Effective dose, which was calculated by multiplying the value of the dose length product by a standard conversion factor of 0.017 for the chest, was employed as a measure of radiation exposure dose. In cardiac CT in patients with BMI of less than 25 kg/m2, the use of 40% ASIR in combination with a low tube potential of 100 kVp resulted in a significant reduction in the radiation dose without compromising diagnostic quality. Additionally, the combination of the 120 kVp protocol and the application of 40% ASIR application for patients with BMI higher than 25 kg/m2 yielded similar results.

  17. Design and performance characteristics of an experimental cesium-137 irradiator to simulate internal radionuclide dose rate patterns.

    PubMed

    Howell, R W; Goddu, S M; Rao, D V

    1997-05-01

    When radionuclides are administered internally, the biological effect can depend on the total absorbed dose and the rate at which it is delivered. A 137Cs irradiator was designed to deliver dose-rate patterns that simulate those encountered in radionuclide therapy. An 18-Ci 137Cs irradiator was fitted with a computer-controlled mercury attenuator that facilitated changes in dose rates as desired. The absorbed dose and dose rates were calibrated with MOSFET dosimeters customized for low dose-rates. Initial dose rates ranging from 0.01-30 cGy/hr can be delivered depending on the location of the cage in the irradiator and the thickness of the mercury in the attenuator system. To demonstrate the irradiator system's capability to deliver dose-rate patterns encountered in radionuclide therapy, a simulation was performed where the dose rate initially increased exponentially followed by an exponential decrease in the dose rate. The irradiator system is well-suited to expose small animals to any dose-rate pattern, thereby facilitating calibration of biological dosimeters (e.g., cell survival, chromosome aberrations), which can be used to measure the absorbed dose to a target tissue after administration of radionuclides.

  18. Harmonization of international risk assessment protocol.

    PubMed

    Toyofuku, Hajime

    2006-01-01

    For over centuries developments in food production and new food safety management systems in most developed countries have been perceived by many to be efficient in the prevention of food-borne disease. Nevertheless a number of problems remain dominant, one of these being the high level of food-borne microbiological disease which seems, for some pathogens, to have increased over the last decades. The development of an interdisciplinary approach with direct interaction between surveillance and risk analysis systems is described as a potential basis for improved prevention of food-borne disease. Quantitative microbiological risk assessment is a relatively new scientific approach, able to link data from food within the entire food chain and the various data on human disease to provide a clear estimation of risk. Today food safety is one of the WHOs top eleven priorities; the Organization calls for more systematic and aggressive steps to be taken to reduce significantly the risk of microbiological food-borne diseases. Dealing with this challenge is one of the major challenges for the 21st century in regard to food safety, implying a significant re-direction of food microbiology efforts in many parts of the world.

  19. Involving Classroom Teachers in the Assessment of Preservice Intern Portfolios.

    ERIC Educational Resources Information Center

    Rakow, Steven J.

    1999-01-01

    The University of Houston-Clear Lake requires preservice teachers to develop a portfolio to demonstrate their proficiency in seven standard areas. The portfolios are developed and assessed under the guidance of university faculty and mentor teachers at the public schools. This team assessment provides interns more extensive and objective feedback,…

  20. International Large-Scale Assessments: What Uses, What Consequences?

    ERIC Educational Resources Information Center

    Johansson, Stefan

    2016-01-01

    Background: International large-scale assessments (ILSAs) are a much-debated phenomenon in education. Increasingly, their outcomes attract considerable media attention and influence educational policies in many jurisdictions worldwide. The relevance, uses and consequences of these assessments are often the focus of research scrutiny. Whilst some…

  1. An International Assessment of Bachelor Degree Graduates' Learning Outcomes

    ERIC Educational Resources Information Center

    Coates, Hamish; Richardson, Sarah

    2012-01-01

    This paper examines rationales, aspirations, assumptions and methods shaping an international assessment of learning outcomes: the OECD's Assessment of Higher Education Learning Outcomes (AHELO) feasibility study. The first part of the paper is analytical, exploring formative rationales, and shaping contexts and normative perspectives that frame…

  2. International Large-Scale Assessments: What Uses, What Consequences?

    ERIC Educational Resources Information Center

    Johansson, Stefan

    2016-01-01

    Background: International large-scale assessments (ILSAs) are a much-debated phenomenon in education. Increasingly, their outcomes attract considerable media attention and influence educational policies in many jurisdictions worldwide. The relevance, uses and consequences of these assessments are often the focus of research scrutiny. Whilst some…

  3. Computational assessment of effective dose and patient specific doses for kilovoltage stereotactic radiosurgery of wet age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Hanlon, Justin Mitchell

    Age-related macular degeneration (AMD) is a leading cause of vision loss and a major health problem for people over the age of 50 in industrialized nations. The current standard of care, ranibizumab, is used to help slow and in some cases stabilize the process of AMD, but requires frequent invasive injections into the eye. Interest continues for stereotactic radiosurgery (SRS), an option that provides a non-invasive treatment for the wet form of AMD, through the development of the IRay(TM) (Oraya Therapeutics, Inc., Newark, CA). The goal of this modality is to destroy choroidal neovascularization beneath the pigment epithelium via delivery of three 100 kVp photon beams entering through the sclera and overlapping on the macula delivering up to 24 Gy of therapeutic dose over a span of approximately 5 minutes. The divergent x-ray beams targeting the fovea are robotically positioned and the eye is gently immobilized by a suction-enabled contact lens. Device development requires assessment of patient effective dose, reference patient mean absorbed doses to radiosensitive tissues, and patient specific doses to the lens and optic nerve. A series of head phantoms, including both reference and patient specific, was derived from CT data and employed in conjunction with the MCNPX 2.5.0 radiation transport code to simulate treatment and evaluate absorbed doses to potential tissues-at-risk. The reference phantoms were used to evaluate effective dose and mean absorbed doses to several radiosensitive tissues. The optic nerve was modeled with changeable positions based on individual patient variability seen in a review of head CT scans gathered. Patient specific phantoms were used to determine the effect of varying anatomy and gaze. The results showed that absorbed doses to the non-targeted tissues were below the threshold levels for serious complications; specifically the development of radiogenic cataracts and radiation induced optic neuropathy (RON). The effective dose

  4. Experimental assessment of proton dose calculation accuracy in inhomogeneous media.

    PubMed

    Sorriaux, J; Testa, M; Paganetti, H; Orban de Xivry, J; Lee, J A; Traneus, E; Souris, K; Vynckier, S; Sterpin, E

    2017-06-01

    Proton therapy with Pencil Beam Scanning (PBS) has the potential to improve radiotherapy treatments. Unfortunately, its promises are jeopardized by the sensitivity of the dose distributions to uncertainties, including dose calculation accuracy in inhomogeneous media. Monte Carlo dose engines (MC) are expected to handle heterogeneities better than analytical algorithms like the pencil-beam convolution algorithm (PBA). In this study, an experimental phantom has been devised to maximize the effect of heterogeneities and to quantify the capability of several dose engines (MC and PBA) to handle these. An inhomogeneous phantom made of water surrounding a long insert of bone tissue substitute (1×10×10 cm(3)) was irradiated with a mono-energetic PBS field (10×10 cm(2)). A 2D ion chamber array (MatriXX, IBA Dosimetry GmbH) lied right behind the bone. The beam energy was such that the expected range of the protons exceeded the detector position in water and did not attain it in bone. The measurement was compared to the following engines: Geant4.9.5, PENH, MCsquare, as well as the MC and PBA algorithms of RayStation (RaySearch Laboratories AB). For a γ-index criteria of 2%/2mm, the passing rates are 93.8% for Geant4.9.5, 97.4% for PENH, 93.4% for MCsquare, 95.9% for RayStation MC, and 44.7% for PBA. The differences in γ-index passing rates between MC and RayStation PBA calculations can exceed 50%. The performance of dose calculation algorithms in highly inhomogeneous media was evaluated in a dedicated experiment. MC dose engines performed overall satisfactorily while large deviations were observed with PBA as expected. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  5. Assessment of patient and occupational dose in established and new applications of MDCT fluoroscopy.

    PubMed

    Joemai, Raoul M S; Zweers, Dirk; Obermann, Wim R; Geleijns, Jacob

    2009-04-01

    This study aimed to assess patient dose and occupational dose in established and new applications of MDCT fluoroscopy. Electronic personal dosimeters were used to measure occupational dose equivalent. Effective patient dose was derived from the recorded dose-length product. Acquisition parameters that were observed during CT fluoroscopy (CTF) provided the basis for the estimation of an entrance skin dose profile. Two hundred ten CT-guided interventional procedures were included in the study. The median effective patient dose was 10 mSv (range, 0.1-235 mSv; 107 procedures). The median peak entrance skin dose was 0.4 Sv (0.1-2.1 Sv; 27 procedures). From 547 measurements of occupational dose equivalent, a median occupational effective dose of 3 muSv per procedure was derived for the interventional radiologists and 0.4 muSv per procedure for the assisting radiologists and radiology technologists. The estimated maximum occupational effective dose reached 0.4 mSv. The study revealed high effective patient doses, up to 235 mSv, mainly for relatively new applications such as CTF-guided radiofrequency ablations using MDCT, vertebroplasty, and percutaneous ethanol injections of tumors. Entrance doses were occasionally in the range of the warning level for deterministic skin effects but were always below the threshold for serious deterministic effects. The complexity of the procedure, expected benefits of the treatment, and general health state of the patient contribute to the justification of observed high effective patient doses.

  6. Assessment and Minimization of Contralateral Breast Dose for Conventional and Intensity Modulated Breast Radiotherapy

    SciTech Connect

    Burmeister, Jay Alvarado, Nicole; Way, Sarah; McDermott, Patrick; Bossenberger, Todd; Jaenisch, Harriett; Patel, Rajiv; Washington, Tara

    2008-04-01

    Breast radiotherapy is associated with an increased risk of contralateral breast cancer (CBC) in women under age 45 at the time of treatment. This risk increases with increasing absorbed dose to the contralateral breast. The use of intensity modulated radiotherapy (IMRT) is expected to substantially reduce the dose to the contralateral breast by eliminating scattered radiation from physical beam modifiers. The absorbed dose to the contralateral breast was measured for 5 common radiotherapy techniques, including paired 15 deg. wedges, lateral 30 deg. wedge only, custom-designed physical compensators, aperture based (field-within-field) IMRT with segments chosen by the planner, and inverse planned IMRT with segments chosen by a leaf sequencing algorithm after dose volume histogram (DVH)-based fluence map optimization. Further reduction in contralateral breast dose through the use of lead shielding was also investigated. While shielding was observed to have the most profound impact on surface dose, the radiotherapy technique proved to be most important in determining internal dose. Paired wedges or compensators result in the highest contralateral breast doses (nearly 10% of the prescription dose on the medial surface), while use of IMRT or removal of the medial wedge results in significantly lower doses. Aperture-based IMRT results in the lowest internal doses, primarily due to the decrease in the number of monitor units required and the associated reduction in leakage dose. The use of aperture-based IMRT reduced the average dose to the contralateral breast by greater than 50% in comparison to wedges or compensators. Combined use of IMRT and 1/8-inch-thick lead shielding reduced the dose to the interior and surface of the contralateral breast by roughly 60% and 85%, respectively. This reduction may warrant the use of IMRT for younger patients who have a statistically significant risk of contralateral breast cancer associated with breast radiotherapy.

  7. Increased absorbed liver dose in Selective Internal Radiation Therapy (SIRT) correlates with increased sphere-cluster frequency and absorbed dose inhomogeneity.

    PubMed

    Högberg, Jonas; Rizell, Magnus; Hultborn, Ragnar; Svensson, Johanna; Henrikson, Olof; Mölne, Johan; Gjertsson, Peter; Bernhardt, Peter

    2015-12-01

    The higher tolerated mean absorbed dose for selective internal radiation therapy (SIRT) with intra-arterially infused (90)Y microspheres compared to external beam therapy is speculated to be caused by absorbed dose inhomogeneity, which allows for liver regeneration. However, the complex liver microanatomy and rheology makes modelling less valuable if the tolerance doses are not based on the actual microsphere distribution. The present study demonstrates the sphere distribution and small-scale absorbed dose inhomogeneity and its correlation with the mean absorbed dose in liver tissue resected after SIRT. A patient with marginally resectable cholangiocarcinoma underwent SIRT 9 days prior to resection including adjacent normal liver tissue. The resected specimen was formalin-fixed and sliced into 1 to 2-mm sections. Forty-one normal liver biopsies 6-8 mm in diameter were punched from these sections and the radioactivity measured. Sixteen biopsies were further processed for detailed analyses by consecutive serial sectioning of 15 30-μm sections per biopsy, mounted and stained with haematoxylin-eosin. All sections were scrutinised for isolated or conglomerate spheres. Small-scale dose distributions were obtained by applying a (90)Y-dose point kernel to the microsphere distributions. A total of 3888 spheres were found in the 240 sections. Clusters were frequently found as strings in the arterioles and as conglomerates in small arteries, with the largest cluster comprising 453 spheres. An increased mean absorbed dose in the punch biopsies correlated with large clusters and a greater coefficient of variation. In simulations the absorbed dose was 5-1240 Gy; 90% were 10-97 Gy and 45% were <30 Gy, the assumed tolerance in external beam therapy. Sphere clusters were located in both arterioles and small arteries and increased in size with increasing sphere concentration, resulting in increased absorbed dose inhomogeneity, which contradicts earlier modelling studies.

  8. Climate Change Impact Assessments for International Market Systems (CLIMARK)

    NASA Astrophysics Data System (ADS)

    Winkler, J. A.; Andresen, J.; Black, J.; Bujdoso, G.; Chmielewski, F.; Kirschke, D.; Kurlus, R.; Liszewska, M.; Loveridge, S.; Niedzwiedz, T.; Nizalov, D.; Rothwell, N.; Tan, P.; Ustrnul, Z.; von Witzke, H.; Zavalloni, C.; Zhao, J.; Zhong, S.

    2012-12-01

    The vast majority of climate change impact assessments evaluate how local or regional systems and processes may be affected by a future climate. Alternative strategies that extend beyond the local or regional scale are needed when assessing the potential impacts of climate change on international market systems, including agricultural commodities. These industries have multiple production regions that are distributed worldwide and are likely to be differentially impacted by climate change. Furthermore, for many industries and market systems, especially those with long-term climate-dependent investments, temporal dynamics need to be incorporated into the assessment process, including changing patterns of international trade, consumption and production, and evolving adaptation strategies by industry stakeholder groups. A framework for conducting climate change assessments for international market systems, developed as part of the CLIMARK (Climate Change and International Markets) project is outlined, and progress toward applying the framework for an impact assessment for the international tart cherry industry is described. The tart cherry industry was selected for analysis in part because tart cherries are a perennial crop requiring long-term investments by the producer. Components of the project include the preparation of fine resolution climate scenarios, evaluation of phenological models for diverse production regions, the development of a yield model for tart cherry production, new methods for incorporating individual decision making and adaptation options into impact assessments, and modification of international trade models for use in impact studies. Innovative aspects of the project include linkages between model components and evaluation of the mega-uncertainty surrounding the assessment outcomes. Incorporation of spatial and temporal dynamics provides a more comprehensive evaluation of climate change impacts and an assessment product of potentially greater

  9. Assessment of gamma-dose rate in city of Kermanshah

    PubMed Central

    Tavakoli, Mohamad Bagher; Kodamoradi, Ehsan; Shaneh, Zahra

    2012-01-01

    Introduction: Environmental natural radiation measurement is of great importance and interest especially for human health. The induction of genetic disorder and cancer appears to be the most important in an exposed population. Materials and Methods: Measurements of background gamma rays were performed using a mini-rad environmental survey meter at 25 different locations around the city of Kermanshah (a city in the west of Iran). The measurements were also performed at two different time of day one in the morning and the other in the afternoon. At each location and time measurements were repeated for five times and the mean was considered as the background dose at that location. Results and Discussions: Comparison between the measured results in the morning and afternoon has not shown any significant difference (P > 0.95). The maximum and minimum obtained results were 2.63 mSv/y and 1.49 mSv/y, respectively. From the total measurements at 25 sites mean and SD background radiation dose to the population is 2.24 ± 0.25 mSv. Conclusion: The mean radiation dose to the population is about 2.5 times of the world average total external exposure cosmic rays and terrestrial gamma rays dose reported by UNSCEAR. PMID:23555133

  10. A dose assessment associated with landspreading petroleum industry NORM.

    SciTech Connect

    Arnish, J. J.; Smith, K. P.; Blunt, D. L.; Environmental Assessment

    2002-04-01

    As a result of oil and gas production and processing operations, naturally occurring radioactive material (NORM) sometimes accumulates at elevated concentrations in byproduct waste streams. The primary radionuclide of concern in NORM wastes are radium-226 (Ra-226) of the uranium-238 decay series; radium-228 of the thorium-232 decay series is also present, but usually at lower concentrations. The production waste streams most likely to be contaminated by elevated radium concentrations include produced water, scale, and sludge. Scales and sludges removed from production equipment sometimes are disposed of by landspreading, a method in which wastes are spread over the soil surface to allow the hydrocarbon component of the wastes to degrade. The disposal of NORM-contaminated wastes by landspreading was modeled to evaluate potential radiological doses to the general public. A variety of future land use scenarios - including residential, industrial, recreational, and agricultural scenarios - were considered. The waste streams considered included scales and sludges containing NORM above background levels. The RESRAD computer code was used to estimate the radiological doses for the maximally exposed receptor for each scenario. Depending on the land-use scenario, potential exposure pathways evaluated for the general public included external radiation; inhalation of contaminated particulates; inhalation of indoor and outdoor radon-222; inadvertent ingestion of contaminated soil; and ingestion of crops, milk, and meat grown on the property. Potential doses were modeled for a unit concentration of 1 Bq g{sup -1} of Ra-226 in soil. Because dose increases linearly with radium concentration, doses were extrapolated for a range of radium concentrations.

  11. Assessment of dose and DNA damages in individuals exposed to low dose and low dose rate ionizing radiations during computed tomography imaging.

    PubMed

    Kanagaraj, Karthik; Abdul Syed Basheerudeen, Safa; Tamizh Selvan, G; Jose, M T; Ozhimuthu, Annalakshmi; Panneer Selvam, S; Pattan, Sudha; Perumal, Venkatachalam

    2015-08-01

    Computed tomography (CT) is a frequently used imaging modality that contributes to a tenfold increase in radiation exposure to the public when compared to other medical imaging modalities. The use of radiation for therapeutic need is always rationalized on the basis of risk versus benefit thereby increasing concerns on the dose received by patients undergoing CT imaging. Therefore, it was of interest to us to investigate the effects of low dose and low dose-rate X-irradiation in patients who underwent CT imaging by recording the doses received by the eye, forehead and thyroid, and to study the levels of damages in the lymphocytes in vivo. Lithium manganese borate doped with terbium (LMB:Tb) thermo luminescence dosimeters (TLD) were used to record the doses in the patient's (n = 27) eye, forehead, and thyroid and compared with the dose length product (DLP) values. The in vivo DNA damages measured were compared before and after CT imaging using chromosomal aberration (CA) and micronucleus (MN) assays. The overall measured organ dose ranged between 2 ± 0.29 and 520 ± 41.63 mGy for the eye, 0.84 ± 0.29 and 210 ± 20.50 mGy for the forehead, and 1.79 ± 0.43 and 185 ± 0.70 mGy for the thyroid. The in vivo damages measured from the blood lymphocytes of the subjects showed an extremely significant (p < 0.0001) increase in CA frequency and significant (p < 0.001) increase in MN frequency after exposure, compared to before exposure. The results suggest that CT imaging delivers a considerable amount of radiation dose to the eye, forehead, and thyroid, and the observed increase in the CA and MN frequencies show low dose radiation effects calling for protective regulatory measures to increase patient's safety. This study is the first attempt to indicate the trend of doses received by the patient's eye, forehead and thyroid and measured directly in contrast to earlier values obtained by extrapolation from phantoms, and to assess the in vivo low dose effects in an Indian

  12. Overview of Dose Assessment Developments and the Health of Riverside Residents Close to the “Mayak” PA Facilities, Russia

    PubMed Central

    Standring, William J.F.; Dowdall, Mark; Strand, Per

    2009-01-01

    The Norwegian Radiation Protection Authority (NRPA) has been involved in studies related to the Mayak PA and the consequences of activities undertaken at the site for a number of years. This paper strives to present an overview of past and present activities at the Mayak PA and subsequent developments in the quantification of health effects on local populations caused by discharges of radioactive waste into the Techa River. Assessments of doses to affected populations have relied on the development of dose reconstruction techniques for both external and internal doses. Contamination levels are typically inhomogeneous and decrease with increasing distance from the discharge point. Citations made in this paper give a comprehensive, though not exhaustive, basis for further reading about this topic. PMID:19440276

  13. International Harmonization of Food Safety Assessment of Pesticide Residues.

    PubMed

    Ambrus, Árpád

    2016-01-13

    This paper summarizes the development of principles and methods applied within the program of the FAO/WHO Codex Alimentarius during the past 50 years for the safety assessment of pesticide residues in food and feed and establishing maximum residue limits (MRLs) to promote free international trade and assure the safety of consumers. The role of major international organizations in this process, the FAO capacity building activities, and some problematic areas that require special attention are briefly described.

  14. International core data sets for integrated environmental assessment

    SciTech Connect

    Singh, A.

    1996-12-31

    Integrated environmental assessments are needed to provide policy relevant information for decision making at national, regional and international scales and the means for priority setting and action planning. One of the important components of integrated assessment is the critical examination of Pressure-State-Impact-Response (PSIR) model in key assessment areas. The paper highlights some of the initiatives of the United Nations Environment Program (UNEP) in assembling the platform of information necessary for constructing an integrated assessment framework for State of the Environment (SOE) reporting. The current status of international core data sets such as land use/land cover, demographics, hydrology, topography, climatology, infrastructure, economy, soils, air quality and water quality, needed for such assessments is also briefly described.

  15. Dose, effect severity, and imparted energy in assessing biological effects.

    PubMed

    Bond, V P

    1995-05-01

    Because of the widespread efforts in cancer radioepidemiological studies to attach a value of absorbed dose to each exposed individual, the notion seems to have become prevalent that dose plays an essential role in the medical determination of the diagnosis and prognosis of the individual. This view is enhanced by the fact that, while the present quantities and units for radiological physics were developed in the context of the acute effects of large exposures to radiation, e.g., in radiotherapy where they still apply well, these same quantities and units have been used, without modification, to apply to cancer radioepidemiology in the context of low level irradiation. A principle purpose of the present communication is to show that, in medicine, dose plays a limited role even in the deterministic application of therapeutic agents, and that diagnosis and estimates of prognosis in medicine are based, not on dose, but on the severity of effect on, or damage to the organ or organs involved in a particular medical condition. Thus it is "going backward" to view estimates of the severity of effect, e.g., the fraction of cells with abnormalities, or killed, as a "biological dosimeter," rather than as a quantitative estimate of the severity of effect. The use of biological indicators is of maximum value in noncancerous disease or injury in which the severity of an effect causative for organ failure and a consequent quantal, e.g., a lethal response in the individual, can be measured with increasing accuracy by modern medical techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. A Needs Assessment for a Longitudinal Emergency Medicine Intern Curriculum.

    PubMed

    Shappell, Eric; Ahn, James

    2017-01-01

    A key task of emergency medicine (EM) training programs is to develop a consistent knowledge of core content in recruits with heterogeneous training backgrounds. The traditional model for delivering core content is lecture-based weekly conference; however, a growing body of literature finds this format less effective and less appealing than alternatives. We sought to address this challenge by conducting a needs assessment for a longitudinal intern curriculum for millennial learners. We surveyed all residents from the six EM programs in the greater Chicago area regarding the concept, format, and scope of a longitudinal intern curriculum. We received 153 responses from the 300 residents surveyed (51% response rate). The majority of respondents (80%; 82% of interns) agreed or strongly agreed that a dedicated intern curriculum would add value to residency education. The most positively rated teaching method was simulation sessions (91% positive responses), followed by dedicated weekly conference time (75% positive responses) and dedicated asynchronous resources (71% positive responses). Less than half of respondents (47%; 26% of interns) supported use of textbook readings in the curriculum. There is strong learner interest in a longitudinal intern curriculum. This needs assessment can serve to inform the development of a universal intern curriculum targeting the millennial generation.

  17. A Needs Assessment for a Longitudinal Emergency Medicine Intern Curriculum

    PubMed Central

    Shappell, Eric; Ahn, James

    2017-01-01

    Introduction A key task of emergency medicine (EM) training programs is to develop a consistent knowledge of core content in recruits with heterogeneous training backgrounds. The traditional model for delivering core content is lecture-based weekly conference; however, a growing body of literature finds this format less effective and less appealing than alternatives. We sought to address this challenge by conducting a needs assessment for a longitudinal intern curriculum for millennial learners. Methods We surveyed all residents from the six EM programs in the greater Chicago area regarding the concept, format, and scope of a longitudinal intern curriculum. Results We received 153 responses from the 300 residents surveyed (51% response rate). The majority of respondents (80%; 82% of interns) agreed or strongly agreed that a dedicated intern curriculum would add value to residency education. The most positively rated teaching method was simulation sessions (91% positive responses), followed by dedicated weekly conference time (75% positive responses) and dedicated asynchronous resources (71% positive responses). Less than half of respondents (47%; 26% of interns) supported use of textbook readings in the curriculum. Conclusion There is strong learner interest in a longitudinal intern curriculum. This needs assessment can serve to inform the development of a universal intern curriculum targeting the millennial generation. PMID:28116005

  18. Assessment of radiation doses from residential smoke detectors that contain americium-241

    SciTech Connect

    O'Donnell, F.R.; Etnier, E.L.; Holton, G.A.; Travis, C.C.

    1981-10-01

    External dose equivalents and internal dose commitments were estimated for individuals and populations from annual distribution, use, and disposal of 10 million ionization chamber smoke detectors that contain 110 kBq (3 ..mu..Ci) americium-241 each. Under exposure scenarios developed for normal distribution, use, and disposal using the best available information, annual external dose equivalents to average individuals were estimated to range from 4 fSv (0.4 prem) to 20 nSv (2 ..mu..rem) for total body and from 7 fSv to 40 nSv for bone. Internal dose commitments to individuals under post disposal scenarios were estimated to range from 0.006 to 80 ..mu..Sv (0.0006 to 8 mrem) to total body and from 0.06 to 800 ..mu..Sv to bone. The total collective dose (the sum of external dose equivalents and 50-year internal dose commitments) for all individuals involved with distribution, use, or disposal of 10 million smoke detectors was estimated to be about 0.38 person-Sv (38 person-rem) to total body and 00 ft/sup 2/).

  19. Assessment of ultrafine particles in Portuguese preschools: levels and exposure doses.

    PubMed

    Fonseca, J; Slezakova, K; Morais, S; Pereira, M C

    2014-12-01

    The aim of this work was to assess ultrafine particles (UFP) number concentrations in different microenvironments of Portuguese preschools and to estimate the respective exposure doses of UFP for 3-5-year-old children (in comparison with adults). UFP were sampled both indoors and outdoors in two urban (US1, US2) and one rural (RS1) preschool located in north of Portugal for 31 days. Total levels of indoor UFP were significantly higher at the urban preschools (mean of 1.82 × 10(4) and 1.32 × 10(4) particles/cm(3) at US1 an US2, respectively) than at the rural one (1.15 × 10(4) particles/cm(3) ). Canteens were the indoor microenvironment with the highest UFP (mean of 5.17 × 10(4) , 3.28 × 10(4) , and 4.09 × 10(4) particles/cm(3) at US1, US2, and RS1), whereas the lowest concentrations were observed in classrooms (9.31 × 10(3) , 11.3 × 10(3) , and 7.14 × 10(3) particles/cm(3) at US1, US2, and RS1). Mean indoor/outdoor ratios (I/O) of UFP at three preschools were lower than 1 (0.54-0.93), indicating that outdoor emissions significantly contributed to UFP indoors. Significant correlations were obtained between temperature, wind speed, relative humidity, solar radiation, and ambient UFP number concentrations. The estimated exposure doses were higher in children attending urban preschools; 3-5-year-old children were exposed to 4-6 times higher UFP doses than adults with similar daily schedules. This study reports information on ultrafine particles (UFPs) in various indoor and outdoor microenvironments (canteens, classrooms, gymnasiums, and outdoor) of urban and rural preschools. It identifies the potential sources and origins, characterizes the influence of meteorological parameters on UFP levels, and performs a comparison with other existing international studies. To this date, relatively few studies have investigated UFP in preschools (none in Portugal) and none assessed exposure dose for different age-groups. The obtained findings showed that levels of UFP in

  20. Development of the voxel computational phantoms of pediatric patients and their application to organ dose assessment

    NASA Astrophysics Data System (ADS)

    Lee, Choonik

    A series of realistic voxel computational phantoms of pediatric patients were developed and then used for the radiation risk assessment for various exposure scenarios. The high-resolution computed tomographic images of live patients were utilized for the development of the five voxel phantoms of pediatric patients, 9-month male, 4-year female, 8-year female, 11-year male, and 14-year male. The phantoms were first developed as head and torso phantoms and then extended into whole body phantoms by utilizing computed tomographic images of a healthy adult volunteer. The whole body phantom series was modified to have the same anthropometrics with the most recent reference data reported by the international commission on radiological protection. The phantoms, named as the University of Florida series B, are the first complete set of the pediatric voxel phantoms having reference organ masses and total heights. As part of the dosimetry study, the investigation on skeletal tissue dosimetry methods was performed for better understanding of the radiation dose to the active bone marrow and bone endosteum. All of the currently available methodologies were inter-compared and benchmarked with the paired-image radiation transport model. The dosimetric characteristics of the phantoms were investigated by using Monte Carlo simulation of the broad parallel beams of external phantom in anterior-posterior, posterior-anterior, left lateral, right lateral, rotational, and isotropic angles. Organ dose conversion coefficients were calculated for extensive photon energies and compared with the conventional stylized pediatric phantoms of Oak Ridge National Laboratory. The multi-slice helical computed tomography exams were simulated using Monte Carlo simulation code for various exams protocols, head, chest, abdomen, pelvis, and chest-abdomen-pelvis studies. Results have found realistic estimates of the effective doses for frequently used protocols in pediatric radiology. The results were very

  1. Digital breast tomosynthesis: Dose and image quality assessment.

    PubMed

    Maldera, A; De Marco, P; Colombo, P E; Origgi, D; Torresin, A

    2017-01-01

    The aim of this work was to evaluate how different acquisition geometries and reconstruction parameters affect the performance of four digital breast tomosynthesis (DBT) systems (Senographe Essential - GE, Mammomat Inspiration - Siemens, Selenia Dimensions - Hologic and Amulet Innovality - Fujifilm) on the basis of a physical characterization. Average Glandular Dose (AGD) and image quality parameters such as in-plane/in-depth resolution, signal difference to noise ratio (SDNR) and artefact spread function (ASF) were examined. Measured AGD values resulted below EUREF limits for 2D imaging. A large variability was recorded among the investigated systems: the mean dose ratio DBT/2D ranged between 1.1 and 1.9. In-plane resolution was in the range: 2.2mm(-1)-3.8mm(-1) in chest wall-nipple direction. A worse resolution was found for all devices in tube travel direction. In-depth resolution improved with increasing scan angle but was also affected by the choice of reconstruction and post-processing algorithms. The highest z-resolution was provided by Siemens (50°, FWHM=2.3mm) followed by GE (25°, FWHM=2.8mm), while the Fujifilm HR showed the lowest one, despite its wide scan angle (40°, FWHM=4.1mm). The ASF was dependent on scan angle: smaller range systems showed wider ASF curves; however a clear relationship was not found between scan angle and ASF, due to the different post processing and reconstruction algorithms. SDNR analysis, performed on Fujifilm system, demonstrated that pixel binning improves detectability for a fixed dose/projection. In conclusion, we provide a performance comparison among four DBT systems under a clinical acquisition mode. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  2. Preliminary Risk Assessment Associated with IGSCC of BWR Vessel Internals

    SciTech Connect

    A. Ware; K. Morton; M. Nitzel; N. Chokshi; T-Y. Chang

    1999-08-01

    BWR core shrouds and other reactor internals important to safety are experiencing intergranular stress corrosion cracking (IGSCC). The United States Nuclear Regulatory Commission (NRC) has followed the problem, and as part of its investigations, contracted with the Idaho National Engineering and Environmental Laboratory (INEEL) to conduct a risk assessment. The overall project objective is to assess the potential consequences and risks associated with the failure of IGSCC-susceptible BWR vessel internals, with specific consideration given to potential cascading and common mode effects. The paper presents an overview of the program, discusses the results of a preliminary qualitative assessment, and summarizes a simplified risk assessment that was conducted on sequences resulting from failures of jet pump components of a BWR/4 plant.

  3. TRANSPORTATION CASK RECEIPT AND RETURN FACILITY WORKER DOSE ASSESSMENT

    SciTech Connect

    V. Arakali

    2005-02-24

    The purpose of this design calculation is to estimate radiation doses received by personnel working in the Transportation Cask Receipt and Return Facility (TCRRF) of the repository including the personnel at the security gate and cask staging areas. This calculation is required to support the preclosure safety analysis (PCSA) to ensure that the predicted doses are within the regulatory limits prescribed by the U.S. Nuclear Regulatory Commission (NRC). The Cask Receipt and Return Facility receives NRC licensed transportation casks loaded with spent nuclear fuel (SNF) and high-level radioactive waste (HLW). The TCRRF operation starts with the receipt, inspection, and survey of the casks at the security gate and the staging areas, and proceeds to the process facilities. The transportation casks arrive at the site via rail cars or trucks under the guidance of the national transportation system. This calculation was developed by the Environmental and Nuclear Engineering organization and is intended solely for the use of Design and Engineering in work regarding facility design. Environmental and Nuclear Engineering personnel should be consulted before using this calculation for purposes other than those stated herein or for use by individuals other than authorized personnel in the Environmental and Nuclear Engineering organization.

  4. Assessment of effective dose to staff in brachytherapy.

    PubMed

    Faulkner, K; James, H V; Chapple, C L; Rawlings, D J

    1996-11-01

    The aim of this paper is to investigate the problem of monitoring effective dose to hospital staff who are involved in the treatment of tumors using sealed sources placed inside the body (brachytherapy). In addition, the use of an unsealed source to treat the thyroid was also considered. Radiation distributions produced by both sealed sources commonly used in brachytherapy (192I, 137Cs, 226Ra) and an unsealed source used in the treatment of the thyroid (131I) were used to irradiate a Rando phantom. The brachytherapy treatments of esophageal and gynecological carcinoma were simulated. The Rando phantom was loaded with lithium fluoride thermoluminescent dosimeters at positions corresponding to a number of radiosensitive organs. Film badges and electronic personal dosimeters were attached to the Rando phantom at various anatomical sites. The Rando phantom was positioned adjacent to the patient at an angle of 90 degrees to the longitudinal axis of the patient. Irradiations were performed with and without a portable lead screen used on the radiotherapy wards. Effective dose was estimated for each simulated radiotherapy treatment and compared with the personal monitor readings. The data were used as a basis for the provision of advice on the wearing of the film badge dosimeters and the design of portable lead screens. The data also permitted a comparison between the two types of dosimeter when used for personal monitoring in brachytherapy.

  5. Radiation dose assessment from ingestion pathway in Saudi Arabia

    SciTech Connect

    Abdul-Majid, S.; Abdul-Fattah, A.R.A.F.; Abulfaraj, W.H. )

    1992-01-01

    Levels of radioactivities in foodstuffs in the local market have been measured for the period from November 1987 until end of June 1988. Out of the 674 samples analyzed there were 83 milk powder, 85 infant milk powder, 54 infant cereals, 89 meat, 16 lentils, 14 wheat, and 26 macaroni samples. The average radioactivity concentration of {sup 137}Cs and {sup 134}Cs, in these samples in Bq/kg were 19, 13, 18, 6, 10, 25 and 13 respectively. The rest adults and infant foodstuffs had negligible radioactivity levels. The calculated annual doses from ingestion pathway due to {sup 137}Cs and {sup 134}Cs for adults were 3.13 {times} 10{sup {minus}5} Sv and 2.1 {times} 10{sup {minus}5} Sv while for one year old infant they were 12 {times} 10{sup {minus}5} Sv and 8 {times} 10{sup {minus}5} Sv respectively. The estimated accumulated dose for 50 years from {sup 90}Sr due to one year food ingestion for adults and one year old infants were 3.76 {times} 3.76 {times} 10{sup {minus}5} Sv and 5.2 {times} 10{sup {minus}5} Sv respectively.

  6. EMP Attachment 3 DOE-SC PNNL Site Dose Assessment Guidance

    SciTech Connect

    Snyder, Sandra F.

    2011-12-21

    This Dose Assessment Guidance (DAG) describes methods to use to determine the Maximally-Exposed Individual (MEI) location and to estimate dose impact to that individual under the U.S. Department of Energy Office of Science (DOE-SC) Pacific Northwest National Laboratory (PNNL) Site Environmental Monitoring Plan (EMP). This guidance applies to public dose from radioactive material releases to the air from PNNL Site operations. This document is an attachment to the Pacific Northwest National Laboratory (PNNL) Environmental Monitoring Plan (EMP) and describes dose assessment guidance for radiological air emissions. The impact of radiological air emissions from the U.S. Department of Energy Office of Science (DOE-SC) PNNL Site is indicated by dose estimates to a maximally exposed member of the public, referred to as the maximally exposed individual (MEI). Reporting requirements associated with dose to members of the public from radiological air emissions are in 40 CFR Part 61.94, WAC 246-247-080, and DOE Order 458.1. The DOE Order and state standards for dose from radioactive air emissions are consistent with U.S. Environmental Protection Agency (EPA) dose standards in 40 CFR 61.92 (i.e., 10 mrem/yr to a MEI). Despite the fact that the current Contract Requirements Document (CRD) for the DOE-SC PNNL Site operations does not include the requirement to meet DOE CRD 458.1, paragraph 2.b, public dose limits, the DOE dose limits would be met when EPA limits are met.

  7. Assessing health impact assessment: multidisciplinary and international perspectives

    PubMed Central

    Krieger, N; Northridge, M; Gruskin, S; Quinn, M; Kriebel, D; Davey, S; Bassett, M; Rehkopf, D; Miller, C

    2003-01-01

    Health impact assessment (HIA) seeks to expand evaluation of policy and programmes in all sectors, both private and public, to include their impact on population health. While the idea that the public's health is affected by a broad array of social and economic policies is not new and dates back well over two centuries, what is new is the notion—increasingly adopted by major health institutions, such as the World Health Organisation (WHO) and the United Kingdom National Health Services (NHS)—that health should be an explicit consideration when evaluating all public policies. In this article, it is argued that while HIA has the potential to enhance recognition of societal determinants of health and of intersectoral responsibility for health, its pitfalls warrant critical attention. Greater clarity is required regarding criteria for initiating, conducting, and completing HIA, including rules pertaining to decision making, enforcement, compliance, plus paying for their conduct. Critical debate over the promise, process, and pitfalls of HIA needs to be informed by multiple disciplines and perspectives from diverse people and regions of the world. PMID:12933768

  8. Using the Monte Carlo method for assessing the tissue and organ doses of patients in dental radiography

    NASA Astrophysics Data System (ADS)

    Makarevich, K. O.; Minenko, V. F.; Verenich, K. A.; Kuten, S. A.

    2016-05-01

    This work is dedicated to modeling dental radiographic examinations to assess the absorbed doses of patients and effective doses. For simulating X-ray spectra, the TASMIP empirical model is used. Doses are assessed on the basis of the Monte Carlo method by using MCNP code for voxel phantoms of ICRP. The results of the assessment of doses to individual organs and effective doses for different types of dental examinations and features of X-ray tube are presented.

  9. ESTIMATION OF EARLY INTERNAL DOSES TO FUKUSHIMA RESIDENTS AFTER THE NUCLEAR DISASTER BASED ON THE ATMOSPHERIC DISPERSION SIMULATION.

    PubMed

    Kim, Eunjoo; Tani, Kotaro; Kunishima, Naoaki; Kurihara, Osamu; Sakai, Kazuo; Akashi, Makoto

    2016-11-01

    Estimating the early internal doses to residents in the Fukushima Daiichi Nuclear Power Station accident is a difficult task because limited human/environmental measurement data are available. Hence, the feasibility of using atmospheric dispersion simulations created by the Worldwide version of System for Prediction of Environmental Emergency Dose Information 2nd Version (WSPEEDI-II) in the estimation was examined in the present study. This examination was done by comparing the internal doses evaluated based on the human measurements with those calculated using time series air concentration maps ((131)I and (137)Cs) generated by WSPEEDI-II. The results showed that the latter doses were several times higher than the former doses. However, this discrepancy could be minimised by taking into account personal behaviour data that will be available soon. This article also presents the development of a prototype system for estimating the internal dose based on the simulations. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Method for Fast CT/SPECT-Based 3D Monte Carlo Absorbed Dose Computations in Internal Emitter Therapy

    NASA Astrophysics Data System (ADS)

    Wilderman, S. J.; Dewaraja, Y. K.

    2007-02-01

    The DPM (Dose Planning Method) Monte Carlo electron and photon transport program, designed for fast computation of radiation absorbed dose in external beam radiotherapy, has been adapted to the calculation of absorbed dose in patient-specific internal emitter therapy. Because both its photon and electron transport mechanics algorithms have been optimized for fast computation in 3D voxelized geometries (in particular, those derived from CT scans), DPM is perfectly suited for performing patient-specific absorbed dose calculations in internal emitter therapy. In the updated version of DPM developed for the current work, the necessary inputs are a patient CT image, a registered SPECT image, and any number of registered masks defining regions of interest. DPM has been benchmarked for internal emitter therapy applications by comparing computed absorption fractions for a variety of organs using a Zubal phantom with reference results from the Medical Internal Radionuclide Dose (MIRD) Committee standards. In addition, the beta decay source algorithm and the photon tracking algorithm of DPM have been further benchmarked by comparison to experimental data. This paper presents a description of the program, the results of the benchmark studies, and some sample computations using patient data from radioimmunotherapy studies using 131I

  11. [International trend of guidance for nanomaterial risk assessment].

    PubMed

    Hirose, Akihiko

    2013-01-01

    In the past few years, several kinds of opinions or recommendations on the nanomaterial safety assessment have been published from international or national bodies. Among the reports, the first practical guidance of risk assessment from the regulatory body was published from the European Food Safety Authorities in May 2011, which included the determination of exposure scenario and toxicity testing strategy. In October 2011, European Commission (EC) adopted the definition of "nanomaterial" for regulation. And more recently, Scientific Committee on Consumer Safety of EC released guidance for assessment of nanomaterials in cosmetics in June 2012. A series of activities in EU marks an important step towards realistic safety assessment of nanomaterials. On the other hand, the US FDA announced a draft guidance for industry in June 2011, and then published draft guidance documents for both "Cosmetic Products" and "Food Ingredients and Food Contact Substances" in April 2012. These draft documents do not restrictedly define the physical properties of nanomaterials, but when manufacturing changes alter the dimensions, properties, or effects of an FDA-regulated product, the products are treated as new products. Such international movements indicate that most of nanomaterials with any new properties would be assessed or regulated as new products by most of national authorities in near future, although the approaches are still case by case basis. We will introduce such current international activities and consideration points for regulatory risk assessment.

  12. Estimating Toxicity Pathway Activating Doses for High Throughput Chemical Risk Assessments

    EPA Science Inventory

    Estimating a Toxicity Pathway Activating Dose (TPAD) from in vitro assays as an analog to a reference dose (RfD) derived from in vivo toxicity tests would facilitate high throughput risk assessments of thousands of data-poor environmental chemicals. Estimating a TPAD requires def...

  13. Estimating Toxicity Pathway Activating Doses for High Throughput Chemical Risk Assessments

    EPA Science Inventory

    Estimating a Toxicity Pathway Activating Dose (TPAD) from in vitro assays as an analog to a reference dose (RfD) derived from in vivo toxicity tests would facilitate high throughput risk assessments of thousands of data-poor environmental chemicals. Estimating a TPAD requires def...

  14. A dosimetric study of cardiac dose sparing using the reverse semi-decubitus technique for left breast and internal mammary chain irradiation.

    PubMed

    Niglas, Mark; McCann, Claire; Keller, Brian M; Makhani, Nadiya; Presutti, Joseph; Vesprini, Danny; Rakovitch, Eileen; Elzibak, Alyaa; Mashouf, Shahram; Lee, Justin

    2016-01-01

    Breath-hold techniques can reduce cardiac dose in breast radiotherapy. The reverse semi-decubitus (RSD) technique is an alternative free-breathing method used at our centre. This study compares the dosimetry of free-breathing supine, RSD and moderate deep inspiration breath-hold (mDIBH) techniques. Twelve patients with left-sided breast cancer who were simulated using standard supine, RSD and mDIBH techniques were identified retrospectively. New plans using standard breast tangents and techniques for internal mammary chain (IMC) nodal coverage were assessed. Using standard tangents, mean heart dose, heart V25Gy and mean left anterior descending artery (LAD) dose were found to be significantly lower for RSD and mDIBH when compared to free-breathing supine (p ⩽ 0.03). Using wide-tangents, the maximum LAD point dose was also lower for RSD and mDIBH (p ⩽ 0.02). There were no statistically significant dosimetric differences found between the RSD and mDIBH simulation techniques for standard breast-tangent plans, though organ-at-risk doses were lower for mDIBH in wide-tangent plans. There was no improvement in cardiac dosimetry between RSD and free-breathing supine when using an electron field IMC plan. For patients unable to tolerate breath-hold, the RSD technique is an alternative approach that can reduce cardiac dose. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. A method for calculating Bayesian uncertainties on internal doses resulting from complex occupational exposures.

    PubMed

    Puncher, M; Birchall, A; Bull, R K

    2012-08-01

    Estimating uncertainties on doses from bioassay data is of interest in epidemiology studies that estimate cancer risk from occupational exposures to radionuclides. Bayesian methods provide a logical framework to calculate these uncertainties. However, occupational exposures often consist of many intakes, and this can make the Bayesian calculation computationally intractable. This paper describes a novel strategy for increasing the computational speed of the calculation by simplifying the intake pattern to a single composite intake, termed as complex intake regime (CIR). In order to assess whether this approximation is accurate and fast enough for practical purposes, the method is implemented by the Weighted Likelihood Monte Carlo Sampling (WeLMoS) method and evaluated by comparing its performance with a Markov Chain Monte Carlo (MCMC) method. The MCMC method gives the full solution (all intakes are independent), but is very computationally intensive to apply routinely. Posterior distributions of model parameter values, intakes and doses are calculated for a representative sample of plutonium workers from the United Kingdom Atomic Energy cohort using the WeLMoS method with the CIR and the MCMC method. The distributions are in good agreement: posterior means and Q(0.025) and Q(0.975) quantiles are typically within 20 %. Furthermore, the WeLMoS method using the CIR converges quickly: a typical case history takes around 10-20 min on a fast workstation, whereas the MCMC method took around 12-72 hr. The advantages and disadvantages of the method are discussed.

  16. Natural radioactivities in iron and nickel ores imported into Japan and the dose assessment for workers handling them.

    PubMed

    Iwaoka, Kazuki; Tagami, Keiko; Yonehara, Hidenori

    2010-09-01

    Japan imports Fe and Ni ores from abroad for use as industrial raw materials in the manufacture of industrial products like stainless steel. Some of these ores might contain high levels of radioactivity, and then workers handling them would be exposed to radiation without being aware of it. Activity concentrations in these ores should be measured to evaluate the radiation exposure of workers. In this study, Fe and Ni ores used as industrial raw materials were collected from iron and steel companies, and the activity concentrations of the (238)U series, the (232)Th series and (40)K in these ores were determined using inductively coupled plasma mass spectrometry (ICP-MS) and gamma ray spectrometry. The activity concentrations of the (238)U series, the (232)Th series and (40)K in these ores samples were lower than the International Atomic Energy Agency (IAEA) values. The doses to workers handling these ores were estimated using methods for dose assessment given in a report by the European Commission. In each scenario, a maximum value of the annual effective dose to workers was estimated to be about 6.8 × 10(-6) Sv, which was lower than intervention exemption levels (annual dose 1.0 × 10(-3) Sv) given in International Commission on Radiological Protection (ICRP) Publication 82.

  17. International Students' Satisfaction: Assessing the Determinants of Satisfaction

    ERIC Educational Resources Information Center

    Asare-Nuamah, Peter

    2017-01-01

    Studies have shown that students' satisfaction is an important element that should be given much attention by educators in their policymaking. Students' satisfaction has impact on retention and financial capacity of institutions. With the objective of assessing the factors affecting international students' satisfaction, a descriptive research was…

  18. Internal Medicine Residents Do Not Accurately Assess Their Medical Knowledge

    ERIC Educational Resources Information Center

    Jones, Roger; Panda, Mukta; Desbiens, Norman

    2008-01-01

    Background: Medical knowledge is essential for appropriate patient care; however, the accuracy of internal medicine (IM) residents' assessment of their medical knowledge is unknown. Methods: IM residents predicted their overall percentile performance 1 week (on average) before and after taking the in-training exam (ITE), an objective and well…

  19. International Computer and Information Literacy Study: Assessment Framework

    ERIC Educational Resources Information Center

    Fraillon, Julian; Schulz, Wolfram; Ainley, John

    2013-01-01

    The purpose of the International Computer and Information Literacy Study 2013 (ICILS 2013) is to investigate, in a range of countries, the ways in which young people are developing "computer and information literacy" (CIL) to support their capacity to participate in the digital age. To achieve this aim, the study will assess student…

  20. Assessing Student Learning Outcomes Internationally: Insights and Frontiers

    ERIC Educational Resources Information Center

    Coates, Hamish

    2016-01-01

    As higher education systems and institutions expand, more energy is being invested in ensuring that sufficient learning has been achieved to warrant the award of a qualification. Many commonly used assessment approaches do not scale well, and there remains a pressing need for reform. This paper distils insights from international investigations of…

  1. International Perspective on Assessment & Evaluation of Visual Arts Education.

    ERIC Educational Resources Information Center

    Grauer, Kit, Ed.

    1994-01-01

    The articles in this volume explore various conceptions of assessment and evaluation and the ramifications of these perspectives in a number of countries across many diverse art educational settings. Kit Grauer introduces the theme in "An Editorial: Values and Evaluation." In "International Perspectives on Evaluation and Assessment…

  2. AN INTERNATIONAL WORKSHOP ON LIFE CYCLE IMPACT ASSESSMENT SOPHISTICATION

    EPA Science Inventory

    On November 29-30,1998 in Brussels, an international workshop was held to discuss Life Cycle Impact Assessment (LCIA) Sophistication. Approximately 50 LCA experts attended the workshop from North America, Europe, and Asia. Prominant practicioners and researchers were invited to ...

  3. Internal Medicine Residents Do Not Accurately Assess Their Medical Knowledge

    ERIC Educational Resources Information Center

    Jones, Roger; Panda, Mukta; Desbiens, Norman

    2008-01-01

    Background: Medical knowledge is essential for appropriate patient care; however, the accuracy of internal medicine (IM) residents' assessment of their medical knowledge is unknown. Methods: IM residents predicted their overall percentile performance 1 week (on average) before and after taking the in-training exam (ITE), an objective and well…

  4. Assessing Student Learning Outcomes Internationally: Insights and Frontiers

    ERIC Educational Resources Information Center

    Coates, Hamish

    2016-01-01

    As higher education systems and institutions expand, more energy is being invested in ensuring that sufficient learning has been achieved to warrant the award of a qualification. Many commonly used assessment approaches do not scale well, and there remains a pressing need for reform. This paper distils insights from international investigations of…

  5. An International Review of Autism Knowledge Assessment Measures

    ERIC Educational Resources Information Center

    Harrison, Ashley J.; Slane, Mylissa M.; Hoang, Linh; Campbell, Jonathan M.

    2017-01-01

    Autism spectrum disorder-specific knowledge deficits contribute to current disparities in the timing and quality of autism spectrum disorder services throughout the United States and globally. This study conducted a systematic review of Western and International literature to examine measures used to assess autism spectrum disorder knowledge. This…

  6. Strategically Assessing International Business Course-Specific Learning Aims

    ERIC Educational Resources Information Center

    Kashlak, Roger; Lorenzi, Peter; Cummings, Jeffrey

    2007-01-01

    During the past 30 years, there have been calls for universities and business schools to internationalize curriculum, students and faculty. As most U.S. business schools have added international components to their respective programs, the assessment of these programs was subsequently recommended from accreditation and competitive perspectives. To…

  7. AN INTERNATIONAL WORKSHOP ON LIFE CYCLE IMPACT ASSESSMENT SOPHISTICATION

    EPA Science Inventory

    On November 29-30,1998 in Brussels, an international workshop was held to discuss Life Cycle Impact Assessment (LCIA) Sophistication. Approximately 50 LCA experts attended the workshop from North America, Europe, and Asia. Prominant practicioners and researchers were invited to ...

  8. [ESTIMATION OF IONIZING RADIATION EFFECTIVE DOSES IN THE INTERNATIONAL SPACE STATION CREWS BY THE METHOD OF CALCULATION MODELING].

    PubMed

    Mitrikas, V G

    2015-01-01

    Monitoring of the radiation loading on cosmonauts requires calculation of absorbed dose dynamics with regard to the stay of cosmonauts in specific compartments of the space vehicle that differ in shielding properties and lack means of radiation measurement. The paper discusses different aspects of calculation modeling of radiation effects on human body organs and tissues and reviews the effective dose estimates for cosmonauts working in one or another compartment over the previous period of the International space station operation. It was demonstrated that doses measured by a real or personal dosimeters can be used to calculate effective dose values. Correct estimation of accumulated effective dose can be ensured by consideration for time course of the space radiation quality factor.

  9. The principal results of the International Immune Tolerance Study: a randomized dose comparison.

    PubMed

    Hay, Charles R M; DiMichele, Donna M

    2012-02-09

    The International Immune Tolerance Study was a multicenter, prospective, randomized comparison of high-dose (HD; 200 IU/kg/d) and low-dose (LD; 50 IU/kg 3 times/week) factor VIII regimens in 115 "good-risk," severe high-titer inhibitor hemophilia A subjects. Sixty-six of 115 subjects reached the defined study end points: success, n = 46 (69.7%); partial response, n = 3 (4.5%); and failure, n = 17 (25.8%). Successes did not differ between treatment arms (24 of 58 LD vs 22/57 HD, P = .909). The times taken to achieve a negative titer (P = .027), a normal recovery (P = .002), and tolerance (P = .116, nonsignificant) were shorter with the HD immune tolerance induction (ITI). Peak historical (P = .026) and on-ITI (P = .002) titers were correlated inversely with success, but only peak titer on ITI predicted outcome in a multivariate analysis (P = .002). LD subjects bled more often (odds ratio, 2.2; P = .0019). The early bleed rate/month was 0.62 (LD) and 0.28 (HD; P = .000 24), decreasing by 90% once negative titers were achieved. Bleeding was absent in 8 of 58 LD versus 21 of 57 HD subjects (P = .0085). One hundred twenty-four central catheter infections were reported in 41 subjects (19 LD); infection frequency did not differ between the treatment arms. Neither bleeding nor infection influenced outcome. Although it was stopped early for futility and safety considerations, this trial contributed valuable data toward evidence-based ITI practice.

  10. Relativistic electrons high doses at International Space Station and Foton M2/M3 satellites

    NASA Astrophysics Data System (ADS)

    Dachev, T. P.; Tomov, B.; Matviichuk, Yu.; Dimitrov, Pl.; Bankov, N.

    2009-12-01

    The paper presents observation of relativistic electrons. Data are collected by the Radiation Risk Radiometer-Dosimeters (R3D) B2/B3 modifications during the flights of Foton M2/M3 satellites in 2005 and 2007 as well as by the R3DE instrument at the European Technology Exposure Facility (EuTEF) on the Columbus External Payload Adaptor at the International Space Station (ISS) in the period February 20 - April 28, 2008. On the Foton M2/M3 satellites relativistic electrons are observed more frequently than on the ISS because of higher (62.8°) inclination of the orbit. At both Foton satellites the usual duration of the observations are a few minutes long. On the ISS the duration usually is about 1 min or less. The places of observations of high doses due to relativistic electrons are distributed mainly at latitudes above 50° geographic latitude in both hemispheres on Foton M2/M3 satellites. A very high maximum is found in the southern hemisphere at longitudinal range 0°-60°E. At the ISS the maximums are observed between 45° and 52° geographic latitude in both hemispheres mainly at longitudes equatorward from the magnetic poles. The measured absolute maximums of dose rates generated by relativistic electrons are found to be as follows: 304 μGy h -1 behind 1.75 g cm -2 shielding at Foton M2, 2314 μGy h -1 behind 0.71 g cm -2 shielding at Foton M3 and 19,195 μGy h -1 (Flux is 8363 cm -2 s -1) behind les than 0.4 g cm -2 shielding at ISS.

  11. Dose assessment for sheep exposed to fallout from nuclear test Nancy

    SciTech Connect

    Sasser, L.B.; Soldat, J.K.; Kennedy, W.E. Jr.; Murphy, D.W.

    1982-10-01

    Radiation doses were estimated for sheep wintering on Nevada ranges during the testing at the Nevada Test Site of the nuclear weapon Nancy on March 24, 1953. Exposure pathways considered were inhalation of radionuclides from both cloud passage and resuspension, external exposure of the total body and skin, and ingestion of contaminated forage and soil. Physiological, metabolic, and dosimetric data needed for these calculations were obtained from data appropriate for the sheep. Dose rate and radionuclide deposition values for shot Nancy were used. Radionuclide deposition and retention on the desert vegetation were obtained from data collected during several nuclear tests at the Nevada Test Site. Existing dosimetric computer programs, whose libraries were modified to include the sheep data, and specially developed models were used to estimate the dose commitment for the sheep. The total-body dose for reference sheep located within the 40-mR/hr (H+12) isopleth from all modes of exposure was estimated to be 2.6 rad. Ingestion of fallout on edible vegetation contributed the majority of the dose, whereas inhalation of radionuclides and consumption of contaminated soil from the ground contributed little to the internal doses. The dose to the thyroid of ewes from radioiodine and other radionuclides reaching the thyroid was approximately 400 rad. The calculated uniform dose to the reticulo-rumen was 4 rad; however, if fallout particles were assumed to concentrate in the ventral rumen, a localized dose of 200 rad could have been received by the rumen wall. Estimated dose to the bare skin of ewes was 120 rad. The dose to the fetal thyroid from radioiodine ingested by a pregnant ewe grazing at a location where the dose rate was 40 mR/hr (H+12) was estimated to be 700 rad, or approximately twice the dose to the maternal thyroid.

  12. WRAITH - A Computer Code for Calculating Internal and External Doses Resulting From An Atmospheric Release of Radioactive Material

    SciTech Connect

    Scherpelz, R. I.; Borst, F. J.; Hoenes, G. R.

    1980-12-01

    WRAITH is a FORTRAN computer code which calculates the doses received by a standard man exposed to an accidental release of radioactive material. The movement of the released material through the atmosphere is calculated using a bivariate straight-line Gaussian distribution model, with Pasquill values for standard deviations. The quantity of material in the released cloud is modified during its transit time to account for radioactive decay and daughter production. External doses due to exposure to the cloud can be calculated using a semi-infinite cloud approximation. In situations where the semi-infinite cloud approximation is not a good one, the external dose can be calculated by a "finite plume" three-dimensional point-kernel numerical integration technique. Internal doses due to acute inhalation are cal.culated using the ICRP Task Group Lung Model and a four-segmented gastro-intestinal tract model. Translocation of the material between body compartments and retention in the body compartments are calculated using multiple exponential retention functions. Internal doses to each organ are calculated as sums of cross-organ doses, with each target organ irradiated by radioactive material in a number of source organs. All doses are calculated in rads, with separate values determined for high-LET and low-LET radiation.

  13. QUANTITATION OF MOLECULAR ENDPOINTS FOR THE DOSE-RESPONSE COMPONENT OF CANCER RISK ASSESSMENT

    EPA Science Inventory

    Cancer risk assessment involves the steps of hazard identification, dose-response assessment, exposure assessment and risk characterization. The rapid advances in the use of molecular biology approaches has had an impact on all four components, but the greatest overall current...

  14. QUANTITATION OF MOLECULAR ENDPOINTS FOR THE DOSE-RESPONSE COMPONENT OF CANCER RISK ASSESSMENT

    EPA Science Inventory

    Cancer risk assessment involves the steps of hazard identification, dose-response assessment, exposure assessment and risk characterization. The rapid advances in the use of molecular biology approaches has had an impact on all four components, but the greatest overall current...

  15. Cancer Dose-Response Assessment for Polychlorinated Biphenyls (PCBs) and Application to Environmental Mixtures

    EPA Pesticide Factsheets

    This report updates the cancer dose-response assessment for PCBs and shows how information on toxicity, disposition, and environmental processes can be considered together to evaluate health risks from PCB mixtures in the environment.

  16. ASSESSING RESIDENTIAL EXPOSURE USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL

    EPA Science Inventory

    As part of a workshop sponsored by the Environmental Protection Agency's Office of Research and Development and Office of Pesticide Programs, the Aggregate Stochastic Human Exposure and Dose Simulation (SHEDS) Model was used to assess potential aggregate residential pesticide e...

  17. ASSESSING RESIDENTIAL EXPOSURE USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL

    EPA Science Inventory

    As part of a workshop sponsored by the Environmental Protection Agency's Office of Research and Development and Office of Pesticide Programs, the Aggregate Stochastic Human Exposure and Dose Simulation (SHEDS) Model was used to assess potential aggregate residential pesticide e...

  18. Assessment of gamma dose rates in air in Adana/Turkey.

    PubMed

    Degerlier, M; Ozger, G

    2008-01-01

    This study assesses the outdoor gamma absorbed dose levels in air of the Adana's region. The measurements were taken from 130 different sample points in this area by Eberline Smart Portable (ESP-2) with SPA-6 plastic scintillation detector. The outdoor gamma absorbed dose rates order from 40 to 145 nGy h(-1). Average outdoor gamma dose rates were measured as 65 nGy h(-1). Average effective dose received from outdoor gamma radiation in Adana's region is 80 microSv y(-1).

  19. Gene Expression Response of Mice after a Single Dose of 137Cs as an Internal Emitter

    PubMed Central

    Paul, Sunirmal; Ghandhi, Shanaz A.; Weber, Waylon; Doyle-Eisele, Melanie; Melo, Dunstana; Guilmette, Raymond; Amundson, Sally A.

    2014-01-01

    Cesium-137 is a radionuclide of concern in fallout from reactor accidents or nuclear detonations. When ingested or inhaled, it can expose the entire body for an extended period of time, potentially contributing to serious health consequences ranging from acute radiation syndrome to increased cancer risks. To identify changes in gene expression that may be informative for detecting such exposure, and to begin examining the molecular responses involved, we have profiled global gene expression in blood of male C57BL/6 mice injected with 137CsCl. We extracted RNA from the blood of control or 137CsCl-injected mice at 2, 3, 5, 20 or 30 days after exposure. Gene expression was measured using Agilent Whole Mouse Genome Microarrays, and the data was analyzed using BRB-ArrayTools. Between 466–6,213 genes were differentially expressed, depending on the time after 137Cs administration. At early times (2–3 days), the majority of responsive genes were expressed above control levels, while at later times (20–30 days) most responding genes were expressed below control levels. Numerous genes were overexpressed by day 2 or 3, and then underexpressed by day 20 or 30, including many Tp53-regulated genes. The same pattern was seen among significantly enriched gene ontology categories, including those related to nucleotide binding, protein localization and modification, actin and the cytoskeleton, and in the integrin signaling canonical pathway. We compared the expression of several genes three days after 137CsCl injection and three days after an acute external gamma-ray exposure, and found that the internal exposure appeared to produce a more sustained response. Many common radiation-responsive genes are altered by internally administered 137Cs, but the gene expression pattern resulting from continued irradiation at a decreasing dose rate is extremely complex, and appears to involve a late reversal of much of the initial response. PMID:25162453

  20. The relevance of international assessments to GRAS determinations.

    PubMed

    Kruger, Claire

    2016-08-01

    A discussion of the risk assessment process as applied to the Generally Recognized As Safe (GRAS) determination of safety for new ingredients can benefit from an international perspective. When we think about how risk assessments are performed around the world it is critical to assess what can be learned. What are the similarities? What are the differences? What are the takeaways? It is important to talk about the similarities in processes, because it validates the approach taken by risk assessors who are charged with protecting the food supply. It is also instructive to evaluate the differences in order to determine where improvements can be made to our process.

  1. The Chernobyl Accident 20 Years On: An Assessment of the Health Consequences and the International Response

    PubMed Central

    Baverstock, Keith; Williams, Dillwyn

    2006-01-01

    Background The Chernobyl accident in 1986 caused widespread radioactive contamination and enormous concern. Twenty years later, the World Health Organization and the International Atomic Energy Authority issued a generally reassuring statement about the consequences. Accurate assessment of the consequences is important to the current debate on nuclear power. Objectives Our objectives in this study were to evaluate the health impact of the Chernobyl accident, assess the international response to the accident, and consider how to improve responses to future accidents. Discussion So far, radiation to the thyroid from radioisotopes of iodine has caused several thousand cases of thyroid cancer but very few deaths; exposed children were most susceptible. The focus on thyroid cancer has diverted attention from possible nonthyroid effects, such as mini-satellite instability, which is potentially important. The international response to the accident was inadequate and uncoordinated, and has been unjustifiably reassuring. Accurate assessment of Chernobyl’s future health effects is not currently possible in the light of dose uncertainties, current debates over radiation actions, and the lessons from the late consequences of atomic bomb exposure. Conclusions Because of the uncertainties over the dose from and the consequences of the Chernobyl accident, it is essential that investigations of its effects should be broadened and supported for the long term. Because of the problems with the international response to Chernobyl, the United Nations should initiate an independent review of the actions and assignments of the agencies concerned, with recommendations for dealing with future international-scale accidents. These should involve independent scientists and ensure cooperation rather than rivalry. PMID:16966081

  2. Appropriate Use of Effective Dose in Radiation Protection and Risk Assessment.

    PubMed

    Fisher, Darrell R; Fahey, Frederic H

    2017-08-01

    Effective dose was introduced by the ICRP for the single, over-arching purpose of setting limits for radiation protection. Effective dose is a derived quantity or mathematical construct and not a physical, measurable quantity. The formula for calculating effective dose to a reference model incorporates terms to account for all radiation types, organ and tissue radiosensitivities, population groups, and multiple biological endpoints. The properties and appropriate applications of effective dose are not well understood by many within and outside the health physics profession; no other quantity in radiation protection has been more confusing or misunderstood. According to ICRP Publication 103, effective dose is to be used for "prospective dose assessment for planning and optimization in radiological protection, and retrospective demonstration of compliance for regulatory purposes." In practice, effective dose has been applied incorrectly to predict cancer risk among exposed persons. The concept of effective dose applies generally to reference models only and not to individual subjects. While conceived to represent a measure of cancer risk or heritable detrimental effects, effective dose is not predictive of future cancer risk. The formula for calculating effective dose incorporates committee-selected weighting factors for radiation quality and organ sensitivity; however, the organ weighting factors are averaged across all ages and both genders and thus do not apply to any specific individual or radiosensitive subpopulations such as children and young women. Further, it is not appropriate to apply effective dose to individual medical patients because patient-specific parameters may vary substantially from the assumptions used in generalized models. Also, effective dose is not applicable to therapeutic uses of radiation, as its mathematical underpinnings pertain only to observed late (stochastic) effects of radiation exposure and do not account for short-term adverse

  3. A comprehensive dose assessment of irradiated hand by iridium-192 source in industrial radiography.

    PubMed

    Hosseini Pooya, S M; Dashtipour, M R; Paydar, R; Mianji, F; Pourshahab, B

    2017-09-04

    Among the various incidents in industrial radiography, inadvertent handling of sources by hands is one of the most frequent incidents in which some parts of the hands may be locally exposed to high doses. An accurate assessment of extremity dose assists medical doctors in selecting appropriate treatments, preventing the injury expansion in the region. In this study, a phantom was designed to simulate a fisted hand of a radiographer when the worker holds a radioactive source in their hands. The local doses were measured using implanted TLDs in the phantom at different distances from a source. Furthermore, skin dose distribution was measured by Gaf-chromic films in the palm region of the phantom. The reliability of the measurements has been studied via analytical as well as Monte-Carlo simulation methods. The results showed that the new phantom design can be used reliably in extremity dose assessments, particularly at the points next to the source.

  4. Dosimetric models of the eye and lens of the eye and their use in assessing dose coefficients for ocular exposures.

    PubMed

    Bolch, W E; Dietze, G; Petoussi-Henss, N; Zankl, M

    2015-06-01

    Based upon recent epidemiological studies of ocular exposure, the Main Commission of the International Commission on Radiological Protection (ICRP) in ICRP Publication 118 states that the threshold dose for radiation-induced cataracts is now considered to be approximately 0.5 Gy for both acute and fractionated exposures. Consequently, a reduction was also recommended for the occupational annual equivalent dose to the lens of the eye from 150 mSv to 20 mSv, averaged over defined periods of 5 years. To support ocular dose assessment and optimisation, Committee 2 included Annex F within ICRP Publication 116 . Annex F provides dose coefficients - absorbed dose per particle fluence - for photon, electron, and neutron irradiation of the eye and lens of the eye using two dosimetric models. The first approach uses the reference adult male and female voxel phantoms of ICRP Publication 110. The second approach uses the stylised eye model of Behrens et al., which itself is based on ocular dimensional data given in Charles and Brown. This article will review the data and models of Annex F with particular emphasis on how these models treat tissue regions thought to be associated with stem cells at risk.

  5. ACS/HRC Internal Assessment of Data Quality

    NASA Astrophysics Data System (ADS)

    Sirianni, Marco

    2006-07-01

    This program will assess the functionality of HRC after the ACS Suspend event that occurred on day 266 2006.A series of Bias, 0.1 sec pseudo dark, Dark and internal flat will be executed through amps A and B to assessdata quality.10-09-2006 : visits 01-03 should be withdrawn. 10-10-2006: visits 04-07 contains bias and dark frames to allow the creation of reference files using the standardamount of images. Two pairs of internal flats have been added for sanity checks.

  6. 4D cone beam CT-based dose assessment for SBRT lung cancer treatment

    NASA Astrophysics Data System (ADS)

    Cai, Weixing; Dhou, Salam; Cifter, Fulya; Myronakis, Marios; Hurwitz, Martina H.; Williams, Christopher L.; Berbeco, Ross I.; Seco, Joao; Lewis, John H.

    2016-01-01

    The purpose of this research is to develop a 4DCBCT-based dose assessment method for calculating actual delivered dose for patients with significant respiratory motion or anatomical changes during the course of SBRT. To address the limitation of 4DCT-based dose assessment, we propose to calculate the delivered dose using time-varying (‘fluoroscopic’) 3D patient images generated from a 4DCBCT-based motion model. The method includes four steps: (1) before each treatment, 4DCBCT data is acquired with the patient in treatment position, based on which a patient-specific motion model is created using a principal components analysis algorithm. (2) During treatment, 2D time-varying kV projection images are continuously acquired, from which time-varying ‘fluoroscopic’ 3D images of the patient are reconstructed using the motion model. (3) Lateral truncation artifacts are corrected using planning 4DCT images. (4) The 3D dose distribution is computed for each timepoint in the set of 3D fluoroscopic images, from which the total effective 3D delivered dose is calculated by accumulating deformed dose distributions. This approach is validated using six modified XCAT phantoms with lung tumors and different respiratory motions derived from patient data. The estimated doses are compared to that calculated using ground-truth XCAT phantoms. For each XCAT phantom, the calculated delivered tumor dose values generally follow the same trend as that of the ground truth and at most timepoints the difference is less than 5%. For the overall delivered dose, the normalized error of calculated 3D dose distribution is generally less than 3% and the tumor D95 error is less than 1.5%. XCAT phantom studies indicate the potential of the proposed method to accurately estimate 3D tumor dose distributions for SBRT lung treatment based on 4DCBCT imaging and motion modeling. Further research is necessary to investigate its performance for clinical patient data.

  7. International Global Crop Condition Assessments in the framework of GEOGLAM

    NASA Astrophysics Data System (ADS)

    Becker-Reshef, I.; Justice, C. O.; Vermote, E.; Whitcraft, A. K.; Claverie, M.

    2013-12-01

    The Group on Earth Observations (partnership of governments and international organizations) developed the Global Agricultural Monitoring (GEOGLAM) initiative in response to the growing calls for improved agricultural information. The goal of GEOGLAM is to strengthen the international community's capacity to produce and disseminate relevant, timely and accurate forecasts of agricultural production at national, regional and global scales through the use of Earth observations. This initiative is designed to build on existing agricultural monitoring initiatives at national, regional and global levels and to enhance and strengthen them through international networking, operationally focused research, and data/method sharing. GEOGLAM was adopted by the G20 as part of the action plan on food price volatility and agriculture and is being implemented through building on the extensive GEO Agricultural Community of Practice (CoP) that was initiated in 2007 and includes key national and international agencies, organizations, and universities involved in agricultural monitoring. One of the early GEOGLAM activities is to provide harmonized global crop outlooks that offer timely qualitative consensus information on crop status and prospects. This activity is being developed in response to a request from the G-20 Agricultural Market Information System (AMIS) and is implemented within the global monitoring systems component of GEOGLAM. The goal is to develop a transparent, international, multi-source, consensus assessment of crop growing conditions, status, and agro-climatic conditions, likely to impact global production. These assessments are focused on the four primary crop types (corn, wheat, soy and rice) within the main agricultural producing regions of the world. The GEOGLAM approach is to bring together international experts from global, regional and national monitoring systems that can share and discuss information from a variety of independent complementary sources in

  8. Assessment of adequacy of hemodialysis dose at a Palestinian hospital.

    PubMed

    Adas, Heba; Al-Ramahi, Rowa; Jaradat, Nidal; Badran, Rand

    2014-03-01

    Adequacy of hemodialysis improves patient survival, quality of life and biochemical outcomes and minimizes disease complications and hospitalizations. This study was an observational cross-sectional study that was conducted in July 2012. Blood tests, weight and blood pressure were measured before and after hemodialysis. Single-pool Kt/V and urea reduction ratio (URR) were calculated. The targets based on the National Kidney Foundation Disease Outcomes Quality Initiative (KDOQI) Clinical Practice Guidelines were Kt/V ≥ 1.2 and URR ≥ 65%. Of the 64 patients, 41 (64.1%) were males. The mean age of the patients was 58.13 ± 17.2 years. The mean body mass index (BMI) was 25.04 ± 5.01 kg/m 2 . The mean Kt/V and URR were 1.06 ± 0.05 and 54.4 ± 19.3, respectively. There was no significant difference between men and women (1.06 ± 0.47 versus 1.04 ± 0.55, P = 0.863) and (54.7 ± 19.59 versus 53.81 ± 19.17, P = 0.296). Only 25 (39.1%) patients achieved the Kt/V goal and only 22 (34.4%) had target URR, and there was no significant association between hemodialysis adequacy and any of the variables such as sex, age, presence of chronic diseases or BMI. Serum potassium levels post-dialysis were significantly lower in patients who reached the target Kt/V (mean = 3.44 ± 0.48 versus 3.88 ± 0.48, P = 0.001). Most patients were inadequately dialyzed and a large percentage of the patients did not attain the targets. Attempts to achieve the desired goals are necessary. It is important to calculate Kt/V or URR and individualize the dialysis doses for each patient.

  9. Rescuing Data from International Scientific Assessments: A Case Study

    NASA Astrophysics Data System (ADS)

    Downs, R. R.; Chen, R. S.; Xing, X.

    2016-12-01

    International scientific assessments such as the Millennium Ecosystem Assessment (MA) and the Intergovernmental Panel on Climate Change (IPCC) assessments represent significant efforts by the global scientific community to review, synthesize, and communicate diverse scientific knowledge, data, and information to support societal decision making on pressing problems such as resource management and climate change. To support the transparency, integrity, and usability of these assessments, it is vital that the underlying data used in these assessments be made openly available and usable by diverse stakeholders. Unfortunately, due to the many geographically dispersed contributors to assessments of this kind, as well as the severe time pressures and limited resources when assessments are conducted, appropriate management and preservation of these data are not always a priority. This can lead to the need to "rescue" key data to ensure their long-term preservation, integrity, accessibility, and appropriate reuse, especially in subsequent assessments. We describe here efforts over two decades to rescue selected data from the MA and IPCC assessments, to work with assessment authors and other contributors to validate and document assessment data, and to develop appropriate levels of data stewardship in light of potential user needs and constrained resources. The IPCC efforts are supported by the IPCC Data Distribution Center (DDC), which is operated collaboratively by the Center for Environmental Data Analysis in the United Kingdom, the World Data Center-Climate in Germany, and the NASA Socioeconomic Data and Applications Center (SEDAC) in the U.S. With the sixth IPCC assessment cycle now starting, a key challenge is to help the assessment community improve data management during the assessment process to reduce the risks of data loss, inadequate documentation, incomplete provenance, unnecessary data restrictions, and other problems.

  10. ANDROS: A code for Assessment of Nuclide Doses and Risks with Option Selection

    SciTech Connect

    Begovich, C.L.; Sjoreen, A.L.; Ohr, S.Y.; Chester, R.O.

    1986-11-01

    ANDROS (Assessment of Nuclide Doses and Risks with Option Selection) is a computer code written to compute doses and health effects from atmospheric releases of radionuclides. ANDROS has been designed as an integral part of the CRRIS (Computerized Radiological Risk Investigation System). ANDROS reads air concentrations and environmental concentrations of radionuclides to produce tables of specified doses and health effects to selected organs via selected pathways (e.g., ingestion or air immersion). The calculation may be done for an individual at a specific location or for the population of the whole assessment grid. The user may request tables of specific effects for every assessment grid location. Along with the radionuclide concentrations, the code requires radionuclide decay data, dose and risk factors, and location-specific data, all of which are available within the CRRIS. This document is a user manual for ANDROS and presents the methodology used in this code.

  11. Guidelines and Ethical Considerations for Assessment Center Operations: International Task Force on Assessment Center Guidelines.

    ERIC Educational Resources Information Center

    Public Personnel Management, 2000

    2000-01-01

    This update of the International Personnel Management Association's guidelines for organizational psychologists, human resource management specialists, and others addresses elements of assessment centers, policy statements, assessor training, informed participation, and participants' rights. (SK)

  12. Guidelines and Ethical Considerations for Assessment Center Operations: International Task Force on Assessment Center Guidelines.

    ERIC Educational Resources Information Center

    Public Personnel Management, 2000

    2000-01-01

    This update of the International Personnel Management Association's guidelines for organizational psychologists, human resource management specialists, and others addresses elements of assessment centers, policy statements, assessor training, informed participation, and participants' rights. (SK)

  13. [Environmental damage assessment: international regulations and revelation to China].

    PubMed

    Zhang, Hong-zhen; Cao, Dong; Yu, Fang; Wang, Jin-nan; Qi, Ji; Jia, Qian; Zhang, Tian-zhu; Luo, Yong-ming

    2013-05-01

    As the whole society gradually realizes the scarcity of nature resources and environmental value, countries all over the world have evolved and improved the system of environmental damage assessment through the practices of pollution prevention and ecological environmental protection. On one hand, in the research prospective, the practices of environmental damage assessment brought new challenges to environmental law, environmental economics, environmental science, environmental engineering, etc. On the other hand, they constantly promoted and developed relevant laws and regulations, techniques, working mechanism, and guidelines on procedure in practice. On the hasis of comparison and analysis of international practices and experiences from US, EU, and Japan, etc., this article identified relevant concepts, content, and scope of environmental damage assessment, and presented its scientific positioning and development direction. At present, both theory and practice of environmental damage assessment in China are in their infancy period. Considering current environmental situation and socioeconomic development features of China, learning international practices and experiences and raising the orientation of environmental damage assessment have great meaning in exploring the suitable environmental damage assessment system.

  14. Assessment of human effective absorbed dose of 67 Ga-ECC based on biodistribution rat data.

    PubMed

    Shanehsazzadeh, Saeed; Yousefnia, Hassan; Lahooti, Afsaneh; Zolghadri, Samaneh; Jalilian, Amir Reza; Afarideh, Hossien

    2015-02-01

    In a diagnostic context, determination of absorbed dose is required before the introduction of a new radiopharmaceutical to the market to obtain marketing authorization from the relevant agencies. In this work, the absorbed dose of [67 Ga]-ethylenecysteamine cysteine [(67 Ga)ECC] to human organs was determined by using distribution data for rats. For biodistribution data, the animals were sacrificed by CO2 asphyxiation at selected times after injection (0.5, 2 and 48 h, n = 3 for each time interval), then the tissue (blood, heart, lung, brain, intestine, feces, skin, stomach, kidneys, liver, muscle and bone) were removed. The absorbed dose was determined by Medical Internal Radiation Dose (MIRD) method after calculating cumulated activities in each organ. Our prediction shows that a 185-MBq injection of (67)Ga-ECC into the humans might result in an estimated absorbed dose of 0.029 mGy in the whole body. The highest absorbed doses are observed in the spleen and liver with 33.766 and 16.847 mGy, respectively. The results show that this radiopharmaceutical can be a good SPECT tracer since it can be produced easily and also the absorbed dose in each organ is less than permitted absorbed dose.

  15. A biosphere modeling methodology for dose assessments of the potential Yucca Mountain deep geological high level radioactive waste repository.

    PubMed

    Watkins, B M; Smith, G M; Little, R H; Kessler, J

    1999-04-01

    Recent developments in performance standards for proposed high level radioactive waste disposal at Yucca Mountain suggest that health risk or dose rate limits will likely be part of future standards. Approaches to the development of biosphere modeling and dose assessments for Yucca Mountain have been relatively lacking in previous performance assessments due to the absence of such a requirement. This paper describes a practical methodology used to develop a biosphere model appropriate for calculating doses from use of well water by hypothetical individuals due to discharges of contaminated groundwater into a deep well. The biosphere model methodology, developed in parallel with the BIOMOVS II international study, allows a transparent recording of the decisions at each step, from the specification of the biosphere assessment context through to model development and analysis of results. A list of features, events, and processes relevant to Yucca Mountain was recorded and an interaction matrix developed to help identify relationships between them. Special consideration was given to critical/potential exposure group issues and approaches. The conceptual model of the biosphere system was then developed, based on the interaction matrix, to show how radionuclides migrate and accumulate in the biosphere media and result in potential exposure pathways. A mathematical dose assessment model was specified using the flexible AMBER software application, which allows users to construct their own compartment models. The starting point for the biosphere calculations was a unit flux of each radionuclide from the groundwater in the geosphere into the drinking water in the well. For each of the 26 radionuclides considered, the most significant exposure pathways for hypothetical individuals were identified. For 14 of the radionuclides, the primary exposure pathways were identified as consumption of various crops and animal products following assumed agricultural use of the contaminated

  16. Radiological dose assessments at the Kennedy Space Center

    SciTech Connect

    Firstenberg, H.; Jubach, R.; Bartram, B.; Vaughan, F.

    1989-01-01

    This paper discusses the application of an atmospheric transport and diffusion model for launch window and safety risk assessment studies in support of the Galileo (which is scheduled for the October/November 1989 period) and Ulysses (scheduled for {approximately}1 yr after Galileo) missions at the Kennedy Space Center (KSC). The model is resident in the EMERGE software system developed by NUS Corporation and modified for the U.S. Department of Energy (DOE) to provide real-time and safety analyses report support for the launches. The application is unique in that the model accommodates the varied amount of meteorological data at KSC and Cape Canaveral and includes a site-specific algorithm to account for local-scale circulations. This paper focuses on the Galileo mission application, including discussions of the use of the meteorological data available at KSC, integration of the EMERGE sea-breeze algorithm, and examples of real-time and safety analyses report assessments. The Galileo spacecraft is to be launched toward Jupiter using the space shuttle.

  17. Assessment of the radiological impact of gamma and radon dose rates at former U mining sites in Tajikistan.

    PubMed

    Lespukh, E; Stegnar, P; Yunusov, M; Tilloboev, H; Zyazev, G; Kayukov, P; Hosseini, A; Strømman, G; Salbu, B

    2013-12-01

    An assessment of the radiological situation due to exposure to gamma radiation, radon ((222)Rn) and thoron ((220)Rn) was carried out at former uranium (U) mining and processing sites in Taboshar and at Digmai in Tajikistan. Gamma dose rate measurements were made using various field instruments. (222)Rn/(220)Rn measurements were carried out with field instruments for instantaneous measurements and then discriminative (222)Rn/(220)Rn solid state nuclear track detectors (SSNTD) were used for longer representative measurements. The detectors were exposed for an extended period of time in different outdoor and indoor public and residential environments at the selected U legacy sites. The results showed that gamma, (222)Rn and (220)Rn doses were in general low, which consequently implies a low to relatively low radiological risk. The radiation doses deriving from external radiation (gamma dose rate), indoor (222)Rn and (220)Rn with their short-lived progenies did not exceed national or international standards. At none of the sites investigated did the average individual annual effective doses exceed 10 mSv, the recommended threshold value for the general public. A radiation hazard could be associated with exceptional situations, such as elevated exposures to ionizing radiation at the Digmai tailings site and/or in industrial facilities, where gamma and (222)Rn/(220)Rn dose rates could reach values of several 10 mSv/a. Current doses of ionizing radiation do not represent a hazard to the health of the resident public, with the exception of some specific situations. These issues should be adequately addressed to further reduce needless exposure of the resident public to ionizing radiation.

  18. Assessment of natural radioactivity levels and associated dose rates in soil samples from Northern Rajasthan, India.

    PubMed

    Duggal, Vikas; Rani, Asha; Mehra, Rohit; Ramola, R C

    2014-01-01

    The analysis of naturally occurring radionuclides ((226)Ra, (232)Th and (40)K) has been carried out in 40 soil samples collected from four districts of the Northern Rajasthan, India using gamma-ray spectrometry with an NaI(Tl) detector. The activity concentrations of the samples range from 38±9 to 65±11 Bq kg(-1) with a mean value of 52 Bq kg(-1) for (226)Ra, from 8±8 to 32±9 Bq kg(-1) with a mean value of 19 Bq kg(-1) for (232)Th and from 929±185 to 1894±249 Bq kg(-1) with a mean value of 1627 Bq kg(-1) for (40)K. The measured activity concentration of (226)Ra and (40)K in soil was higher and for (232)Th was lower than the worldwide range. Radium equivalent activities were calculated for the soil samples to assess the radiation hazards arising due to the use of these soils in the construction of buildings. The calculated average radium equivalent activity was 205±20 Bq kg(-1), which is less than the recommended limit of 370 Bq kg(-1) by the Organization for Economic Cooperation and Development. The total absorbed dose rate calculated from the activity concentration of (226)Ra, (232)Th and (40)K ranges from 77 to 123 nGy h(-1) with an average value of 103 nGy h(-1). The mean external (Hex) and internal hazard indices (Hin) for the area under study were determined to be 0.55 and 0.69, respectively. The corresponding average annual effective dose was found to be 0.63 mSv.

  19. Displaying 3D radiation dose on endoscopic video for therapeutic assessment and surgical guidance

    NASA Astrophysics Data System (ADS)

    Qiu, Jimmy; Hope, Andrew J.; Cho, B. C. John; Sharpe, Michael B.; Dickie, Colleen I.; DaCosta, Ralph S.; Jaffray, David A.; Weersink, Robert A.

    2012-10-01

    We have developed a method to register and display 3D parametric data, in particular radiation dose, on two-dimensional endoscopic images. This registration of radiation dose to endoscopic or optical imaging may be valuable in assessment of normal tissue response to radiation, and visualization of radiated tissues in patients receiving post-radiation surgery. Electromagnetic sensors embedded in a flexible endoscope were used to track the position and orientation of the endoscope allowing registration of 2D endoscopic images to CT volumetric images and radiation doses planned with respect to these images. A surface was rendered from the CT image based on the air/tissue threshold, creating a virtual endoscopic view analogous to the real endoscopic view. Radiation dose at the surface or at known depth below the surface was assigned to each segment of the virtual surface. Dose could be displayed as either a colorwash on this surface or surface isodose lines. By assigning transparency levels to each surface segment based on dose or isoline location, the virtual dose display was overlaid onto the real endoscope image. Spatial accuracy of the dose display was tested using a cylindrical phantom with a treatment plan created for the phantom that matched dose levels with grid lines on the phantom surface. The accuracy of the dose display in these phantoms was 0.8-0.99 mm. To demonstrate clinical feasibility of this approach, the dose display was also tested on clinical data of a patient with laryngeal cancer treated with radiation therapy, with estimated display accuracy of ˜2-3 mm. The utility of the dose display for registration of radiation dose information to the surgical field was further demonstrated in a mock sarcoma case using a leg phantom. With direct overlay of radiation dose on endoscopic imaging, tissue toxicities and tumor response in endoluminal organs can be directly correlated with the actual tissue dose, offering a more nuanced assessment of normal tissue

  20. Displaying 3D radiation dose on endoscopic video for therapeutic assessment and surgical guidance.

    PubMed

    Qiu, Jimmy; Hope, Andrew J; Cho, B C John; Sharpe, Michael B; Dickie, Colleen I; DaCosta, Ralph S; Jaffray, David A; Weersink, Robert A

    2012-10-21

    We have developed a method to register and display 3D parametric data, in particular radiation dose, on two-dimensional endoscopic images. This registration of radiation dose to endoscopic or optical imaging may be valuable in assessment of normal tissue response to radiation, and visualization of radiated tissues in patients receiving post-radiation surgery. Electromagnetic sensors embedded in a flexible endoscope were used to track the position and orientation of the endoscope allowing registration of 2D endoscopic images to CT volumetric images and radiation doses planned with respect to these images. A surface was rendered from the CT image based on the air/tissue threshold, creating a virtual endoscopic view analogous to the real endoscopic view. Radiation dose at the surface or at known depth below the surface was assigned to each segment of the virtual surface. Dose could be displayed as either a colorwash on this surface or surface isodose lines. By assigning transparency levels to each surface segment based on dose or isoline location, the virtual dose display was overlaid onto the real endoscope image. Spatial accuracy of the dose display was tested using a cylindrical phantom with a treatment plan created for the phantom that matched dose levels with grid lines on the phantom surface. The accuracy of the dose display in these phantoms was 0.8-0.99 mm. To demonstrate clinical feasibility of this approach, the dose display was also tested on clinical data of a patient with laryngeal cancer treated with radiation therapy, with estimated display accuracy of ∼2-3 mm. The utility of the dose display for registration of radiation dose information to the surgical field was further demonstrated in a mock sarcoma case using a leg phantom. With direct overlay of radiation dose on endoscopic imaging, tissue toxicities and tumor response in endoluminal organs can be directly correlated with the actual tissue dose, offering a more nuanced assessment of normal tissue

  1. Effective dose assessment for participants in the National Lung Screening Trial undergoing posteroanterior chest radiographic examinations.

    PubMed

    Kruger, Randell; Flynn, Michael J; Judy, Phillip F; Cagnon, Christopher H; Seibert, J Anthony

    2013-07-01

    The National Lung Screening Trial (NLST) is a multicenter randomized controlled trial comparing low-dose helical CT with chest radiography in the screening of older current and former heavy smokers for early detection of lung cancer. Recruitment was launched in September 2002 and ended in April 2004, when 53,454 participants had been randomized at 33 screening sites. The objective of this study was to determine the effective radiation dose associated with individual chest radiographic screening examinations. A total of 73,733 chest radiographic examinations were performed with 92 chest imaging systems. The entrance skin air kerma (ESAK) of participants' chest radiographic examinations was estimated and used in this analysis. The effective dose per ESAK for each examination was determined with a Monte Carlo-based program. The examination effective dose was calculated as the product of the examination ESAK and the Monte Carlo estimate of the ratio of effective dose per ESAK. This study showed that the mean effective dose assessed from 66,157 postero-anterior chest examinations was 0.052 mSv. Additional findings were a median effective dose of 0.038 mSv, a 95th percentile value of 0.136 mSv, and a fifth percentile value of 0.013 mSv. The effective dose for participant NLST chest radiographic examinations was determined and is of specific interest in relation to that associated with the previously published NLST low-dose CT examinations conducted during the trial.

  2. Comparison of normal tissue dose with three-dimensional conformal techniques for breast cancer irradiation including the internal mammary nodes

    SciTech Connect

    Laan, Hans P. van der . E-mail: h.p.van.der.laan@rt.umcg.nl; Dolsma, Wil V.; Veld, Aart A. van 't; Bijl, Hendrik P.; Langendijk, Johannes A.

    2005-12-01

    Purpose: To compare the Para Mixed technique for irradiation of the internal mammary nodes (IMN) with three commonly used strategies, by analyzing the dose to the heart and other organs at risk. Methods and Materials: Four different three-dimensional conformal dose plans were created for 30 breast cancer patients. The IMN were enclosed with the Para Mixed technique by a widened mediolateral tangent photon beam and an anterior electron beam, with the Patched technique by an anterior electron beam, with the Standard technique by an anterior photon and electron beam, and with the PWT technique by partially wide tangents. All techniques were optimized for conformality and produced equally adequate target coverage. Results: Heart dose was lowest with the Para Mixed and Patched technique for all patients and with the PWT technique for right-sided treatment only. Lung dose was highest with the PWT, lowest with the Patched, and intermediate with the Para Mixed and Standard techniques. Skin dose was highest with the Patched, lowest with the PWT, and intermediate with the Para Mixed and the Standard techniques. The Para Mixed technique resulted in a 13-Gy lower dose in an overlap area, and the PWT technique was the only technique that incorporated considerable volumes of the contralateral breast. Conclusion: The Para Mixed technique yielded the overall best results. No other technique resulted in a lower heart dose. Lung and skin were equally spared instead of one of them being compromised, and the contralateral breast was avoided.

  3. Dose assessment intercomparisons within the RENEB network using G0-lymphocyte prematurely condensed chromosomes (PCC assay).

    PubMed

    Terzoudi, Georgia I; Pantelias, Gabriel; Darroudi, Firouz; Barszczewska, Katarzyna; Buraczewska, Iwona; Depuydt, Julie; Georgieva, Dimka; Hadjidekova, Valeria; Hatzi, Vasiliki I; Karachristou, Ioanna; Karakosta, Maria; Meschini, Roberta; M'Kacher, Radhia; Montoro, Alegria; Palitti, Fabrizio; Pantelias, Antonio; Pepe, Gaetano; Ricoul, Michelle; Sabatier, Laure; Sebastià, Natividad; Sommer, Sylwester; Vral, Anne; Zafiropoulos, Demetre; Wojcik, Andrzej

    2017-01-01

    Dose assessment intercomparisons within the RENEB network were performed for triage biodosimetry analyzing G0-lymphocyte PCC for harmonization, standardization and optimization of the PCC assay. Comparative analysis among different partners for dose assessment included shipment of PCC-slides and captured images to construct dose-response curves for up to 6 Gy γ-rays. Accident simulation exercises were performed to assess the suitability of the PCC assay by detecting speed of analysis and minimum number of cells required for categorization of potentially exposed individuals. Calibration data based on Giemsa-stained fragments in excess of 46 PCC were obtained by different partners using galleries of PCC images for each dose-point. Mean values derived from all scores yielded a linear dose-response with approximately 4 excess-fragments/cell/Gy. To unify scoring criteria, exercises were carried out using coded PCC-slides and/or coded irradiated blood samples. Analysis of samples received 24 h post-exposure was successfully performed using Giemsa staining (1 excess-fragment/cell/Gy) or centromere/telomere FISH-staining for dicentrics. Dose assessments by RENEB partners using appropriate calibration curves were mostly in good agreement. The PCC assay is quick and reliable for whole- or partial-body triage biodosimetry by scoring excess-fragments or dicentrics in G0-lymphocytes. Particularly, analysis of Giemsa-stained excess PCC-fragments is simple, inexpensive and its automation could increase throughput and scoring objectivity of the PCC assay.

  4. In Vitro Partial-Body Dose Assessment Using a Radiation Responsive Protein Biomarker

    DTIC Science & Technology

    2005-01-01

    partial - body ionizing radiation exposure . The radiation responsive protein biomarker studied was Growth Arrest DNA-Damage... radiation responsive protein bioassay to assess partial - body exposures in a murine in vivo validation, 23 These projects would offer a... REPORT TYPE 3. DATES COVERED - 4. TITLE AND SUBTITLE In Vitro Partial - Body Dose Assessment Using a Radiation Responsive Protein Biomarker

  5. Analysis of Data from a System of Assessment of the Gonadal Radiation Dose During Radiographic Procedures

    PubMed Central

    Duggan, H. E.; Olde, G. L.

    1965-01-01

    The radiation hazard, if any, from diagnostic x-ray examinations was assessed in a study divided into three phases: (1) the gathering of data to allow estimation of the total gonadal dose received by each patient; (2) the accumulation of the individual and accumulative gonadal-dose totals on a large group of patients; (3) the examination and follow-up of patients who had received a substantial gonadal dose to determine any relationship between small recurring doses of ionizing radiation and various indices of somatic and genetic damage. The mean gonadal dose received by females was much higher than that received by males—1012 mr. as compared to 310 mr. Of 7021 individuals in this study, only 428 (6.1%) received 2 r. or more during the three-year test period. No definite conclusions as to radiation hazard could be made. A system, however, has been developed which, if continued, could eventually produce this basic information. PMID:14281086

  6. Assessment of the dose from radon and its decay products in the Bozkov dolomite cave.

    PubMed

    Rovenská, K; Thinová, L; Zdímal, V

    2008-01-01

    The dose from radon and its progeny remains a frequently discussed problem. ICRP 65 provides a commonly used methodology to calculate the dose from radon. Our work focuses on a cave environment and on assessing the doses in public open caves. The differences in conditions (aerosol size distribution, humidity, radon and its progeny ratio, etc.) are described by the so-called cave factor j. The cave factor is used to correct the dose for workers which is calculated using the ICRP 65 recommendation. In this work, the authors have brought together measured data of aerosol size distribution, unattached and attached fraction activity, and have calculated the so-called cave factor for the Bozkov dolomite cave environment. The dose conversion factors based on measured data and used for evaluating the cave factor were calculated by LUDEP software, which implements HRTM ICRP66.

  7. Objective assessment of image quality and dose reduction in CT iterative reconstruction

    SciTech Connect

    Vaishnav, J. Y. Jung, W. C.; Popescu, L. M.; Zeng, R.; Myers, K. J.

    2014-07-15

    Purpose: Iterative reconstruction (IR) algorithms have the potential to reduce radiation dose in CT diagnostic imaging. As these algorithms become available on the market, a standardizable method of quantifying the dose reduction that a particular IR method can achieve would be valuable. Such a method would assist manufacturers in making promotional claims about dose reduction, buyers in comparing different devices, physicists in independently validating the claims, and the United States Food and Drug Administration in regulating the labeling of CT devices. However, the nonlinear nature of commercially available IR algorithms poses challenges to objectively assessing image quality, a necessary step in establishing the amount of dose reduction that a given IR algorithm can achieve without compromising that image quality. This review paper seeks to consolidate information relevant to objectively assessing the quality of CT IR images, and thereby measuring the level of dose reduction that a given IR algorithm can achieve. Methods: The authors discuss task-based methods for assessing the quality of CT IR images and evaluating dose reduction. Results: The authors explain and review recent literature on signal detection and localization tasks in CT IR image quality assessment, the design of an appropriate phantom for these tasks, possible choices of observers (including human and model observers), and methods of evaluating observer performance. Conclusions: Standardizing the measurement of dose reduction is a problem of broad interest to the CT community and to public health. A necessary step in the process is the objective assessment of CT image quality, for which various task-based methods may be suitable. This paper attempts to consolidate recent literature that is relevant to the development and implementation of task-based methods for the assessment of CT IR image quality.

  8. Treatment of early non-response in patients with schizophrenia: assessing the efficacy of antipsychotic dose escalation.

    PubMed

    Loebel, Antony; Citrome, Leslie; Correll, Christoph U; Xu, Jane; Cucchiaro, Josephine; Kane, John M

    2015-10-31

    Early non-response to antipsychotic treatment in patients with schizophrenia has been shown in multiple studies to predict poor response at short-term trial endpoint. Therefore, strategies to address the challenge of non-improvement early in the course of treatment are needed. A novel trial design was developed to assess the potential utility of antipsychotic dose escalation in patients with an inadequate initial treatment response. This design was embedded in a study intended to assess the efficacy of low dose lurasidone in patients with schizophrenia. The purpose of this report is to describe the background, rationale and design of this study that included a novel method for the assessment of the potential for dose-response in early non-responding patients with schizophrenia. In this 6-week, international, multicenter, double-blind trial, eligible adults with acute schizophrenia were randomized to receive fixed doses of lurasidone 20 mg/day, 80 mg/day (active control), or placebo in a 1:2:1 ratio. Patients initially randomized to lurasidone 80 mg/day who did not have a Positive and Negative Syndrome Scale total score improvement ≥ 20% at Week 2 were re-randomized on a 1:1 basis to receive either lurasidone 80 mg/day or lurasidone 160 mg/day for the remainder of the trial. All other groups remained on their initially assigned treatment. The formal primary objective of the study was to evaluate the efficacy of low-dose lurasidone (20 mg/day) compared to placebo; secondary objectives included evaluating the efficacy of lurasidone 80 mg/day versus 160 mg/day in early non-responders, and evaluating the efficacy of lurasidone in all subjects initially randomized to 80 mg/day versus placebo. Since a lack of early improvement predicts poor response to short-term antipsychotic treatment in patients with schizophrenia, several treatment strategies have been proposed to enhance treatment outcome in early non-responders. A novel clinical trial design involving a placebo

  9. Comparison of 50-year and 70-year internal-dose-conversion factors

    SciTech Connect

    Ryan, M.T.; Dunning, D.E. Jr.

    1981-03-01

    The 50-year inhalation and ingestion dose commitments associated with an acute intake (of a radionuclide) of 3.7 x 10/sup 4/ Bq (1 ..mu..Ci) in one day were compared with the corresponding dose commitments calculated for a 70-year integration period resulting from a chronic intake of the same amount at a rate of 101 Bq/d (0.00274 ..mu..Ci/d) for one year. These values, known as dose conversion factors, estimate the dose accumulated during a given period of time following a unit of intake of a radionuclide. It was demonstrated that the acute intake of 3.7 x 10/sup 4/ Bq in one day and the chronic intake of 101 Bq/d for one year (a total intake of 3.7 x 10/sup 4/ Bq) result in essentially the same dose commitment for a relatively long integration period. Therefore, the comparison of 50-year acute dose conversion factors and 70-year chronic dose conversion factors is essentially only a measure of the additional dose accumulated in the 50 to 70 year period. It was found that for radionuclides with atomic mass less than 200 the percent difference in the 70-year and 50-year dose conversion factors was essentially zero in most cases. Differences of approximately 5 to 50% were obtained for dose conversion factors for most alpha emitters with atomic masses of greater than 200. Comparisons were made on the basis of both organ dose equivalent and effective dose equivalent. The implications and significance of these results are discussed.

  10. 10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... year, from radiation sources external to the body, a deep dose equivalent in excess of 0.1 rem (1 mSv), a lens dose equivalent in excess of 0.15 rem (1.5 mSv), or a shallow dose equivalent to the skin or to the extremities in excess of 0.5 rem (5 mSv); (3) Declared pregnant women likely to receive during...

  11. 10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... year, from radiation sources external to the body, a deep dose equivalent in excess of 0.1 rem (1 mSv), a lens dose equivalent in excess of 0.15 rem (1.5 mSv), or a shallow dose equivalent to the skin or to the extremities in excess of 0.5 rem (5 mSv); (3) Declared pregnant women likely to receive during...

  12. 10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... year, from radiation sources external to the body, a deep dose equivalent in excess of 0.1 rem (1 mSv), a lens dose equivalent in excess of 0.15 rem (1.5 mSv), or a shallow dose equivalent to the skin or to the extremities in excess of 0.5 rem (5 mSv); (3) Declared pregnant women likely to receive during...

  13. 10 CFR 20.1502 - Conditions requiring individual monitoring of external and internal occupational dose.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... year, from radiation sources external to the body, a deep dose equivalent in excess of 0.1 rem (1 mSv), a lens dose equivalent in excess of 0.15 rem (1.5 mSv), or a shallow dose equivalent to the skin or to the extremities in excess of 0.5 rem (5 mSv); (3) Declared pregnant women likely to receive during...

  14. Assessment of the effective doses from two dental cone beam CT devices

    PubMed Central

    Schilling, R; Geibel, M-A

    2013-01-01

    Objectives: This study compares the effective dose for different fields of view (FOVs), resolutions and X-ray parameters from two cone beam CT units: the KaVo 3D (three-dimensional) eXam and the KaVo Pan eXam Plus 3D (KaVo Dental, Biberach, Germany). Methods: Measurements were made using thermoluminescent dosemeter chips in a radiation analog dosimetry head and neck phantom. The calculations of effective doses are based on the ICRP 60 and ICRP 103 recommendations of the International Commission on Radiological Protection. Results: Effective doses from the 3D eXam ranged between 32.8 µSv and 169.8 µSv, and for the Pan eXam Plus effective doses ranged between 40.2 µSv and 183.7 µSv; these were measured using ICRP 103 weighting factors in each case. The increase in effective dose between ICRP 60 and ICRP 103 recommendations averaged 157% for all measurements. Conclusions: Effective doses can be reduced significantly with the choice of lower resolutions and mAs settings as well as smaller FOVs to avoid tissues sensitive to radiation being inside the direct beam. Larger FOVs do not necessarily lead to higher effective doses. PMID:23420855

  15. Assessment of the effective doses from two dental cone beam CT devices.

    PubMed

    Schilling, R; Geibel, M-A

    2013-01-01

    This study compares the effective dose for different fields of view (FOVs), resolutions and X-ray parameters from two cone beam CT units: the KaVo 3D (three-dimensional) eXam and the KaVo Pan eXam Plus 3D (KaVo Dental, Biberach, Germany). Measurements were made using thermoluminescent dosemeter chips in a radiation analog dosimetry head and neck phantom. The calculations of effective doses are based on the ICRP 60 and ICRP 103 recommendations of the International Commission on Radiological Protection. Effective doses from the 3D eXam ranged between 32.8 µSv and 169.8 µSv, and for the Pan eXam Plus effective doses ranged between 40.2 µSv and 183.7 µSv; these were measured using ICRP 103 weighting factors in each case. The increase in effective dose between ICRP 60 and ICRP 103 recommendations averaged 157% for all measurements. Effective doses can be reduced significantly with the choice of lower resolutions and mAs settings as well as smaller FOVs to avoid tissues sensitive to radiation being inside the direct beam. Larger FOVs do not necessarily lead to higher effective doses.

  16. Identification and dose assessment of irradiated cardamom and cloves by EPR spectrometry

    NASA Astrophysics Data System (ADS)

    Beshir, W. B.

    2014-03-01

    The use of electron paramagnetic resonance spectroscopy to accurately distinguish irradiated from unirradiated cardamom and cloves and assesses the absorbed dose to radiation processed cardamom and cloves are examined. The results were successful for identifying both irradiated and unirradiated cardamom and cloves. Additive reirradiation of cardamom and cloves produces reproducible dose-response functions, which can be used to assess the initial dose by back-extrapolation. Third degree polynomial function was used to fit the EPR signal/dose curves. It was found that this 3rd degree polynomial function provides satisfactory results without correction of decay for free radicals. The stability of the radiation induced EPR signal of irradiated cardamom and cloves were studied over a storage period of almost 8 months.

  17. Qualitative and quantitative approaches in the dose-response assessment of genotoxic carcinogens.

    PubMed

    Fukushima, Shoji; Gi, Min; Kakehashi, Anna; Wanibuchi, Hideki; Matsumoto, Michiharu

    2016-05-01

    Qualitative and quantitative approaches are important issues in field of carcinogenic risk assessment of the genotoxic carcinogens. Herein, we provide quantitative data on low-dose hepatocarcinogenicity studies for three genotoxic hepatocarcinogens: 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and N-nitrosodiethylamine (DEN). Hepatocarcinogenicity was examined by quantitative analysis of glutathione S-transferase placental form (GST-P) positive foci, which are the preneoplastic lesions in rat hepatocarcinogenesis and the endpoint carcinogenic marker in the rat liver medium-term carcinogenicity bioassay. We also examined DNA damage and gene mutations which occurred through the initiation stage of carcinogenesis. For the establishment of points of departure (PoD) from which the cancer-related risk can be estimated, we analyzed the above events by quantitative no-observed-effect level and benchmark dose approaches. MeIQx at low doses induced formation of DNA-MeIQx adducts; somewhat higher doses caused elevation of 8-hydroxy-2'-deoxyquanosine levels; at still higher doses gene mutations occurred; and the highest dose induced formation of GST-P positive foci. These data indicate that early genotoxic events in the pathway to carcinogenesis showed the expected trend of lower PoDs for earlier events in the carcinogenic process. Similarly, only the highest dose of IQ caused an increase in the number of GST-P positive foci in the liver, while IQ-DNA adduct formation was observed with low doses. Moreover, treatment with DEN at low doses had no effect on development of GST-P positive foci in the liver. These data on PoDs for the markers contribute to understand whether genotoxic carcinogens have a threshold for their carcinogenicity. The most appropriate approach to use in low dose-response assessment must be approved on the basis of scientific judgment.

  18. Radiological dose assessment related to management of naturally occurring radioactive materials generated by the petroleum industry

    SciTech Connect

    Smith, K.P.; Blunt, D.L.; Williams, G.P.; Tebes, C.L.

    1996-09-01

    A preliminary radiological dose assessment of equipment decontamination, subsurface disposal, landspreading, equipment smelting, and equipment burial was conducted to address concerns regarding the presence of naturally occurring radioactive materials (NORM) in production waste streams. The assessment estimated maximum individual dose equivalents for workers and the general public. Sensitivity analyses of certain input parameters also were conducted. On the basis of this assessment, it is concluded that (1) regulations requiring workers to wear respiratory protection during equipment cleaning operations are likely to result in lower worker doses, (2) underground injection and downhole encapsulation of NORM wastes present a negligible risk to the general public, and (3) potential doses to workers and the general public related to smelting NORM-contaminated equipment can be controlled by limiting the contamination level of the initial feed. It is recommended that (1) NORM wastes be further characterized to improve studies of potential radiological doses; (2) states be encouraged to permit subsurface disposal of NORM more readily, provided further assessments support this study; results; (3) further assessment of landspreading NORM wastes be conducted; and (4) the political, economic, sociological, and nonradiological issues related to smelting NORM-contaminated equipment be studied to fully examine the feasibility of this disposal option.

  19. Development and application of a tomographic model from CT images for calculating internal dose to a pregnant woman

    NASA Astrophysics Data System (ADS)

    Shi, Chengyu

    Assessment of radiation dose and possible risk to a pregnant woman and her fetus is an important task in radiation protection. Although stylized models for male and female patients of different ages have been developed, tomographic models for pregnant women have not been developed to date. This dissertation presents an effort to construct a partial-body model of a pregnant woman from a set of CT images. The patient was 30-weeks pregnant, and the CT scan covered the portion of the body between the lower breast and the upper thigh in 70 slices, each 7 mm thick. The image resolution was 512 x 512 pixels in a 48 cm x 48 cm field. The images were carefully segmented to identify 34 organs and tissues, It has been found that the masses are different from the Reference Woman. The characteristics of the resulting model is discussed and compared with one existing stylized mathematical model for pregnant women. Based on this tomographic model, a Monte Carlo code, EGS4-VLSI, was used to derive Specific Absorbed Fractions. Monoenergetic and isotropic photon and electron emitters distributed in different source organs were assumed and the energies ranged from 10 keV to 4 MeV for photons and from 100 keV to 4 MeV for electrons. The results for high energy (>50 keV) photons showed general agreement with previous studies, however, the results for lower energy (<50 keV) photons showed differences of up to several hundreds percent for some source and target organs. For electron results, several tens of percent differences were found. Those differences can be explained by mass differences and the relative geometry differences between source and target organs. In summary, the stylized models for pregnant women are satisfactory for a very large size patient for most of the photon energies (between 50 keV and 4 MeV). However, a tomographic model has to be used to obtain acceptable dose assessments for electrons. The newly calculated SAF data set can provide the nuclear medicine dosimetry

  20. The debate on the use of linear no threshold for assessing the effects of low doses.

    PubMed

    Tubiana, M; Aurengo, A; Averbeck, D; Masse, R

    2006-09-01

    From December 2004 to July 2005, three reports on the effects of low doses of ionising radiation were released: ICRP (2004), the joint report of the French Academies of Science and Medicine (Tubiana et al 2005), and a report from the American Academy of Sciences (BEIR VII 2005). These reports quote the same recent articles on the biological effects of low doses, yet their conclusions diverge. The French report concludes that recent biological data show that the efficacy of defense mechanisms is modulated by dose and dose rate and that linear no threshold (LNT) is no longer plausible. The ICRP and the BEIR VII reports recognise that there are biologic arguments against LNT but feel that there are not sufficient biological proofs against it to change risk assessment methodology and subsequent regulatory policy based on LNT. They point out the remaining uncertainties and the lack of mechanistic explanations of phenomena such as low dose hyperlethality or the adaptive response. In this context, a critical analysis of the available data is necessary. The epidemiological data and the experimental data challenge the validity of the LNT hypothesis for assessing the carcinogenic effect of low doses, but do not allow its exclusion. Therefore, the main criteria for selecting the most reliable dose-effect relationship from a scientific point of view should be based on biological data. Their analysis should help one to understand the current controversy.

  1. Evaluation of the neutron spectrum and dose assessment around the venus reactor.

    PubMed

    Coeck, Michèle; Vermeersch, Fernand; Vanhavere, Filip

    2005-01-01

    An assessment of the neutron field near the VENUS reactor is made in order to evaluate the neutron dose to the operators, particularly in an area near the reactor shielding and in the control room. Therefore, a full MCNPX model of the shielding geometry was developed. The source term used in the simulation is derived from a criticality calculation done beforehand. Calculations are compared to routine neutron dose rate measurements and show good agreement. The MCNPX model developed easily allows core adaptations in order to evaluate the effect of future core configuration on the neutron dose to the operators.

  2. Assessing the Clinical Impact of Approximations in Analytical Dose Calculations for Proton Therapy

    SciTech Connect

    Schuemann, Jan Giantsoudi, Drosoula; Grassberger, Clemens; Moteabbed, Maryam; Min, Chul Hee; Paganetti, Harald

    2015-08-01

    Purpose: To assess the impact of approximations in current analytical dose calculation methods (ADCs) on tumor control probability (TCP) in proton therapy. Methods: Dose distributions planned with ADC were compared with delivered dose distributions as determined by Monte Carlo simulations. A total of 50 patients were investigated in this analysis with 10 patients per site for 5 treatment sites (head and neck, lung, breast, prostate, liver). Differences were evaluated using dosimetric indices based on a dose-volume histogram analysis, a γ-index analysis, and estimations of TCP. Results: We found that ADC overestimated the target doses on average by 1% to 2% for all patients considered. The mean dose, D95, D50, and D02 (the dose value covering 95%, 50% and 2% of the target volume, respectively) were predicted within 5% of the delivered dose. The γ-index passing rate for target volumes was above 96% for a 3%/3 mm criterion. Differences in TCP were up to 2%, 2.5%, 6%, 6.5%, and 11% for liver and breast, prostate, head and neck, and lung patients, respectively. Differences in normal tissue complication probabilities for bladder and anterior rectum of prostate patients were less than 3%. Conclusion: Our results indicate that current dose calculation algorithms lead to underdosage of the target by as much as 5%, resulting in differences in TCP of up to 11%. To ensure full target coverage, advanced dose calculation methods like Monte Carlo simulations may be necessary in proton therapy. Monte Carlo simulations may also be required to avoid biases resulting from systematic discrepancies in calculated dose distributions for clinical trials comparing proton therapy with conventional radiation therapy.

  3. MOVING FROM EXTERNAL EXPOSURE CONCENTRATION TO INTERNAL DOSE: DURATION EXTRAPOLATION BASED ON PHYSIOLOGICALLY-BASED PHARMACOKINETIC-MODEL DERIVED ESTIMATES OF INTERNAL DOSE

    EPA Science Inventory

    The potential human health risk(s) from exposure to chemicals under conditions for which adequate human or animal data are not available must frequently be assessed. Exposure scenario is particularly important for the acute neurotoxic effects of volatile organic compounds (VOCs)...

  4. MOVING FROM EXTERNAL EXPOSURE CONCENTRATION TO INTERNAL DOSE: DURATION EXTRAPOLATION BASED ON PHYSIOLOGICALLY-BASED PHARMACOKINETIC-MODEL DERIVED ESTIMATES OF INTERNAL DOSE

    EPA Science Inventory

    The potential human health risk(s) from exposure to chemicals under conditions for which adequate human or animal data are not available must frequently be assessed. Exposure scenario is particularly important for the acute neurotoxic effects of volatile organic compounds (VOCs)...

  5. Psychological assessment in XLMR: a proposal for setting international standards.

    PubMed

    Fisch, G S

    2000-01-01

    The need for an agreed upon set of standards for assessing individuals with XLMR was made quite evident this past year at the Fragile X and XLMR Workshop in Strasbourg. Several affected individuals from different families may have been incorrectly diagnosed as MR. Many factors can have a negative affect on IQ testing. As a result, evaluating individuals with cognitive deficits can be problematic. To be effective, psychological assessments must produce uniform results that are consistent with the definition of MR. Therefore, to foster international research in XLMR. I propose a two-stage standardized protocol. To determine which tests may be suitable. I review an assortment of instruments for psychological assessment at each stage, noting their strengths and weaknesses. Afterward, I present a set of standardized protocols based on age and language ability.

  6. Dose Assessment in Computed Tomography Examination and Establishment of Local Diagnostic Reference Levels in Mazandaran, Iran

    PubMed Central

    Janbabanezhad Toori, A.; Shabestani-Monfared, A.; Deevband, M.R.; Abdi, R.; Nabahati, M.

    2015-01-01

    Background Medical X-rays are the largest man-made source of public exposure to ionizing radiation. While the benefits of Computed Tomography (CT) are well known in accurate diagnosis, those benefits are not risk-free. CT is a device with higher patient dose in comparison with other conventional radiation procedures. Objective This study is aimed at evaluating radiation dose to patients from Computed Tomography (CT) examination in Mazandaran hospitals and defining diagnostic reference level (DRL). Methods Patient-related data on CT protocol for four common CT examinations including brain, sinus, chest and abdomen & pelvic were collected. In each center, Computed Tomography Dose Index (CTDI) measurements were performed using pencil ionization chamber and CT dosimetry phantom according to AAPM report No. 96 for those techniques. Then, Weighted Computed Tomography Dose Index (CTDIW), Volume Computed Tomography Dose Index (CTDI vol) and Dose Length Product (DLP) were calculated. Results The CTDIw for brain, sinus, chest and abdomen & pelvic ranged (15.6-73), (3.8-25. 8), (4.5-16.3) and (7-16.3), respectively. Values of DLP had a range of (197.4-981), (41.8-184), (131-342.3) and (283.6-486) for brain, sinus, chest and abdomen & pelvic, respectively. The 3rd quartile of CTDIW, derived from dose distribution for each examination is the proposed quantity for DRL. The DRLs of brain, sinus, chest and abdomen & pelvic are measured 59.5, 17, 7.8 and 11 mGy, respectively. Conclusion Results of this study demonstrated large scales of dose for the same examination among different centers. For all examinations, our values were lower than international reference doses. PMID:26688796

  7. An appraisal of critical effect sizes for the benchmark dose approach to assess dose-response relationships in genetic toxicology.

    PubMed

    Zeller, Andreas; Duran-Pacheco, Gonzalo; Guérard, Melanie

    2017-08-10

    The benchmark dose (BMD) concept is increasingly utilized to analyze quantitative dose-response relationships in genetic toxicology. This methodology requires the user (i.e. the toxicologist) to a priori define a small increase over controls that is "acceptable" to be induced by a genotoxic test substance. The increase is called benchmark response (BMR) or critical effect size (CES), depending on the software used. To render the metrics calculated from the data of animals treated with the test substance applicable for risk assessment, the BMR or CES must represent biologically relevant changes of parameters measured in in vivo genotoxicity assays such as the Micronucleus, Comet, Transgenic rodent or Pig-a assay. Current recommendations for CES in genotoxicology are arbitrary (10% increase over mean vehicle controls) or based on limited, usually 5-6, data points (i.e. the standard deviation of the concurrent vehicle control group). We have, therefore, analyzed historical vehicle control data of standard in vivo genotoxicity test systems with statistical methods. Based on this evaluation, we illustrate limitations of the currently recommended CES values and propose a pragmatic approach that may contribute to better defining endpoint-specific CES values for BMD software like PROAST.

  8. Factors that elevate the internal radionuclide and chemical retention, dose and health risks to infants and children in a radiological-nuclear emergency.

    PubMed

    Richardson, Richard B

    2009-06-01

    The factors that influence the dose and risk to vulnerable population groups from exposure and internal uptake of chemicals are examined and, in particular, the radionuclides released in chemical, biological, radiological, nuclear and explosive events. The paper seeks to identify the areas that would benefit from further research. The intake and body burdens of carbon and calcium were assessed as surrogates for contaminants that either act like or bind to hydrocarbons (e.g. tritium and (14)C) or bone-seeking radionuclides (e.g. (90)Sr and (239)Pu). The shortest turnover times for such materials in the whole body were evaluated for the newborn: 11 d and 0.5 y for carbon and calcium, respectively. However, their biokinetic behaviour is complicated by a particularly high percentage of the gut-absorbed dietary intake of carbon (approximately 16%) and calcium (approximately 100%) that is incorporated into the soft tissue and skeleton of the growing neonate. The International Commission on Radiological Protection dose coefficients (Sv Bq(-1)) were examined for 14 radionuclides, including 9 of concern because of their potential use in radiological dispersal devices. The dose coefficients for a 3-month-old are greater than those for adults (2-56 times more for ingestion and 2-12 times for inhalation). The age-dependent dose and exposure assessment of contaminant intakes would improve by accounting for gender and growth where it is currently neglected. Health risk is evaluated as the product of the exposure and hazard factors, the latter being about 10-fold greater in infants than in adults. The exposure factor is also approximately 10-fold higher for ingestion by infants than by adults, and unity for inhalation varying with the contaminant. Qualitative and quantitative physiological and epidemiological evidence supports infants being more vulnerable to cancer and neurological deficit than older children.

  9. Computed tomography dose assessment for a 160 mm wide, 320 detector row, cone beam CT scanner.

    PubMed

    Geleijns, J; Salvadó Artells, M; de Bruin, P W; Matter, R; Muramatsu, Y; McNitt-Gray, M F

    2009-05-21

    Computed tomography (CT) dosimetry should be adapted to the rapid developments in CT technology. Recently a 160 mm wide, 320 detector row, cone beam CT scanner that challenges the existing Computed Tomography Dose Index (CTDI) dosimetry paradigm was introduced. The purpose of this study was to assess dosimetric characteristics of this cone beam scanner, to study the appropriateness of existing CT dose metrics and to suggest a pragmatic approach for CT dosimetry for cone beam scanners. Dose measurements with a small Farmer-type ionization chamber and with 100 mm and 300 mm long pencil ionization chambers were performed free in air to characterize the cone beam. According to the most common dose metric in CT, namely CTDI, measurements were also performed in 150 mm and 350 mm long CT head and CT body dose phantoms with 100 mm and 300 mm long pencil ionization chambers, respectively. To explore effects that cannot be measured with ionization chambers, Monte Carlo (MC) simulations of the dose distribution in 150 mm, 350 mm and 700 mm long CT head and CT body phantoms were performed. To overcome inconsistencies in the definition of CTDI100 for the 160 mm wide cone beam CT scanner, doses were also expressed as the average absorbed dose within the pencil chamber (D100). Measurements free in air revealed excellent correspondence between CTDI300air and D100air, while CTDI100air substantially underestimates CTDI300air. Results of measurements in CT dose phantoms and corresponding MC simulations at centre and peripheral positions were weighted and revealed good agreement between CTDI300w, D100w and CTDI600w, while CTDI100w substantially underestimates CTDI300w. D100w provides a pragmatic metric for characterizing the dose of the 160 mm wide cone beam CT scanner. This quantity can be measured with the widely available 100 mm pencil ionization chamber within 150 mm long CT dose phantoms. CTDI300w measured in 350 mm long CT dose phantoms serves as an appropriate standard of

  10. Evaluating quantitative formulas for dose-response assessment of chemical mixtures.

    PubMed

    Hertzberg, Richard C; Teuschler, Linda K

    2002-12-01

    Risk assessment formulas are often distinguished from dose-response models by being rough but necessary. The evaluation of these rough formulas is described here, using the example of mixture risk assessment. Two conditions make the dose-response part of mixture risk assessment difficult, lack of data on mixture dose-response relationships, and the need to address risk from combinations of chemicals because of public demands and statutory requirements. Consequently, the U.S. Environmental Protection Agency has developed methods for carrying out quantitative dose-response assessment for chemical mixtures that require information only on the toxicity of single chemicals and of chemical pair interactions. These formulas are based on plausible ideas and default parameters but minimal supporting data on whole mixtures. Because of this lack of mixture data, the usual evaluation of accuracy (predicted vs. observed) cannot be performed. Two approaches to the evaluation of such formulas are to consider fundamental biological concepts that support the quantitative formulas (e.g., toxicologic similarity) and to determine how well the proposed method performs under simplifying constraints (e.g., as the toxicologic interactions disappear). These ideas are illustrated using dose addition and two weight-of-evidence formulas for incorporating toxicologic interactions.

  11. Occupational radiation dose assessment for the DOE spent-fuel storage facility

    SciTech Connect

    Hadley, J.; Eble, R.G. Jr.

    1997-12-01

    To expedite the licensing process of the centralized interim storage facility (CISF), the U.S. Department of Energy has completed a CISF topical safety analysis report (TSAR). The TSAR will be used in licensing the CISF when a site is designated. An occupational radiation dose assessment of the facility operations is performed as part of the CISF design. The first phase of the CISF has the capability to receive, transfer, and store spent nuclear fuel (SNF) in dual-purpose casks. Currently, there are five vendor technologies under consideration. The preliminary dose assessment is based on estimated occupational exposures using traditional power plant independent spent-fuel storage installation (ISFSI) and transport cask-handling processes. The second step in the process is to recommend as-low-as-reasonably-achievable (ALARA) techniques to reduce potential exposures. A final dose assessment is completed implementing the ALARA techniques, and a review is performed to ensure that the design is in compliance with regulatory criteria. The dose assessment and ALARA evaluation are determined using the following input information: dose estimates from vendor safety analysis reports, ISFSI experience with similar systems, traditional methods of operations, expected CISF cask receipt rates, and feasible ALARA techniques.

  12. International Space Station End-of-Life Probabilistic Risk Assessment

    NASA Technical Reports Server (NTRS)

    Duncan, Gary

    2014-01-01

    Although there are ongoing efforts to extend the ISS life cycle through 2028, the International Space Station (ISS) end-of-life (EOL) cycle is currently scheduled for 2020. The EOL for the ISS will require de-orbiting the ISS. This will be the largest manmade object ever to be de-orbited, therefore safely de-orbiting the station will be a very complex problem. This process is being planned by NASA and its international partners. Numerous factors will need to be considered to accomplish this such as target corridors, orbits, altitude, drag, maneuvering capabilities, debris mapping etc. The ISS EOL Probabilistic Risk Assessment (PRA) will play a part in this process by estimating the reliability of the hardware supplying the maneuvering capabilities. The PRA will model the probability of failure of the systems supplying and controlling the thrust needed to aid in the de-orbit maneuvering.

  13. International Space Station End-of-Life Probabilistic Risk Assessment

    NASA Technical Reports Server (NTRS)

    Duncan, Gary W.

    2014-01-01

    The International Space Station (ISS) end-of-life (EOL) cycle is currently scheduled for 2020, although there are ongoing efforts to extend ISS life cycle through 2028. The EOL for the ISS will require deorbiting the ISS. This will be the largest manmade object ever to be de-orbited therefore safely deorbiting the station will be a very complex problem. This process is being planned by NASA and its international partners. Numerous factors will need to be considered to accomplish this such as target corridors, orbits, altitude, drag, maneuvering capabilities etc. The ISS EOL Probabilistic Risk Assessment (PRA) will play a part in this process by estimating the reliability of the hardware supplying the maneuvering capabilities. The PRA will model the probability of failure of the systems supplying and controlling the thrust needed to aid in the de-orbit maneuvering.

  14. Assessment of opacimeter calibration according to International Standard Organization 10155.

    PubMed

    Gomes, J F

    2001-01-01

    This paper compares the calibration method for opacimeters issued by the International Standard Organization (ISO) 10155 with the manual reference method for determination of dust content in stack gases. ISO 10155 requires at least nine operational measurements, corresponding to three operational measurements per each dust emission range within the stack. The procedure is assessed by comparison with previous calibration methods for opacimeters using only two operational measurements from a set of measurements made at stacks from pulp mills. The results show that even if the international standard for opacimeter calibration requires that the calibration curve is to be obtained using 3 x 3 points, a calibration curve derived using 3 points could be, at times, acceptable in statistical terms, provided that the amplitude of individual measurements is low.

  15. An updated dose assessment for a U.S. Nuclear Test Site - Bikini Atoll

    SciTech Connect

    Robison, W.L.; Bogen, K.T.; Conrado, C.L.

    1995-10-01

    On March 1, 1954, a nuclear weapon test, code-named BRAVO, conducted at Bikini Atoll in the northern Marshall Islands contaminated the major residence island. There has been a continuing effort since 1977 to refine dose assessments for resettlement options at Bikini Atoll. Here we provide a radiological dose assessment for the main residence island, Bikini, using extensive radionuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island as part of our continuing research and monitoring program that began in 1975. The unique composition of coral soil greatly alters the relative contribution of cesium-137 ({sup 137}Cs) and strontium-90 ({sup 90}Sr) to the total estimated dose relative to expectations based on North American and European soils. Without counter measures, cesium-137 produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The doses are calculated assuming a resettlement date of 1999. The estimated maximum annual effective dose for current island conditions is 4.0 mSv when imported foods, which are now an established part of the diet, are available. The corresponding 30-, 50-, and 70-y integral effective doses are 9.1 cSv, 13 cSv, and 15 cSv, respectively. A corresponding uncertainty analysis showed that after about 5 y of residence, the 95% confidence limits on population-average dose would be {plus_minus}35% of its expected value. We have evaluated various countermeasures to reduce {sup 137}Cs in food crops. Treatment with potassium reduces the uptake of {sup 137}Cs into food crops, and therefore the ingestion dose, to about 5% of pretreatment levels and has essentially no negative environmental consequences.

  16. Applying International Standards for Hydrokinetic Energy Resource Assessments

    NASA Astrophysics Data System (ADS)

    Haas, K. A.

    2015-12-01

    The extraction of hydrokinetic energy is the conversion of the kinetic energy of moving water into another more useful form of energy, frequently electricity. This water motion may be in the form of waves, tides, ocean currents or river flows. In addition to the development of the technology, the successful extraction of hydrokinetic energy requires a better understanding of physical, environmental and social aspects of the resource and their interactions with the technology. To assist with the development of the hydrokinetic industry as a whole, much work over the past decade has been completed developing international technical standards which can be used by the full range of stakeholders in the hydrokinetic industry. To support the design of projects for tidal energy extraction, a new International Electrotechnical Commission (IEC) Technical Specification (TS) has recently been published outlining a standardized methodology for performing resource assessments. In addition, presently work is ongoing on producing another TS for performing resource assessments on in-stream river projects. While the specific technology for extracting the energy from tidal and river flows may be similar, the methodologies for performing the respective resource assessments is quite different due to the differing nature of the physical processes involved. This presentation will discuss both the tidal and in-stream river methodologies, highlighting their respective key aspects. In addition, a case study illustrating the use of the published tidal TS will be presented.

  17. Aspects of operational radiation protection during dismantling of nuclear facilities relevant for the estimation of internal doses.

    PubMed

    Labarta, T

    2007-01-01

    Operational radiation protection of workers during the dismantling of nuclear facilities is based on the same radiation protection principles as that applied in its exploitation period with the objective of ensuring proper implementation of the as-low-as-reasonably-achievable (ALARA) principle. These principles are: prior determination of the nature and magnitude of radiological risk; classification of workplaces and workers depending on the risks; implementation of control measures; monitoring of zones and working conditions, including, if necessary, individual monitoring. From the experiences and the lessons learned during the dismantling processes carried out in Spain, several important aspects in the practical implementation of these principles that directly influence and ensure an adequate prevention of exposures and the estimation of internal doses are pointed out, with special emphasis on the estimation of internal doses due to transuranic intakes.

  18. Austrian radiation dose measurements onboard space station mir and the international space station iss - overview and comparison

    NASA Astrophysics Data System (ADS)

    Berger, T.; Hajek, M.; Summerer, L.; Vana, N.; Akatov, Y.; Shurshakov, V.; Arkhangelsky, V.

    The Atominstitut of the Austrian Universities has conducted various space research missions in the last 12 years in cooperation with the Institute for Biomedical Problems in Moscow. They dealt with the exact determination of the radiation hazards for cosmonauts and the development o precise measurement devices.f Special emphasis will be laid on the last experiment on space station MIR the goal of which was the determination of the depth distribution of absorbed dose and dose equivalent in a water filled phantom. The first results from dose measurements onboard the International Space Station will also be discussed.. The phantom with a diameter of 35 cm was developed at the Institute for Biomedical Problems and had 4 channels where dosemeters can be exposed in different depths. The exp osure period covered the timeframe from May 1997 to February 1999. Thermoluminescent dosemeters (TLDs) were exposed inside the phantom, either parallel or perpendicular to the hull of the spacecraft. For the evaluation of the linear energy transfer (LET), the High Temperature Ratio (HTR) - method was applied. Based on this method a mean quality factor and, subsequently, the dose equivalent is calculated according to the Q(LET ) relationship proposed in ICRP 26. An increased contribution of neutrons could be detected inside the phantom. However the total dose equivalent did not increase over the depth of the phantom. As the first Austrian measurements on the ISS dosemeter packages were exposed for 248 days, starting in February 2001 at six different locations onboard the ISS. The Austrian dosemeter sets for this first exposure on the ISS contained 5 different kinds of passive thermoluminescent dosemeters. First results showed a position dependent absorbed dose rate and LET at the ISS. Dose rates ranged from 180 to 280 μGy/d. The differences in dose measurements onboard the 2 space stations will be discussed.

  19. Health technology assessment agencies: an international overview of organizational aspects.

    PubMed

    Martelli, Francesco; La Torre, Giuseppe; Di Ghionno, Elena; Staniscia, Tommaso; Neroni, Massimo; Cicchetti, Americo; Von Bremen, Konrade; Ricciardi, Walter

    2007-01-01

    The aim of the study is to make an international comparison of Health Technology Assessment (HTA) Agencies, to show their similarities and differences. An e-mail questionnaire was sent to thirty HTA agencies internationally. Questions related to the structure of the agency, the relationship with health-related institutions, the prescriptiveness of the decisions taken, the main core and the modalities to spread the assessment, and the type of funding. Twenty-four HTA Agencies answered the questionnaire: 25 percent in America, 4.2 percent in Australia, and 70.8 percent in Europe. Fifty-four percent of HTA Agencies are governmental institutions (83.3 percent have central government funding), while 62.5 percent have relationships with health-related governmental institutions. Of the agencies, 87 percent reported that their decisions are not prescriptive, while for 20.8 percent and 8.3 percent of them stated that this was the case totally or partially, respectively, especially for the governmental and American Agencies. Seventeen agencies (70.8 percent) declared their work on multiannual programs (77 percent of the governmental HTA Agencies and 100 percent of the American ones). The assessments mainly addressed diagnostic procedures (85.7 percent) and pharmaceuticals (25 percent). The most common way to disseminate results is by means of paper report (91.7 percent), followed by the Internet (16.7 percent), and seminars to expert audiences (12.5 percent). The comparative analysis of HTA Agencies showed that governmental and American Agencies have a profound impact on the prescriptiveness of their assessment, and this could be linked to the fact that these types of Agencies work on multiannual programs. European and American HTA Agencies have many similarities in terms of type of assessment, funding, and dissemination of results.

  20. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

    PubMed Central

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-01-01

    Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

  1. Fetal dose assessment from invasive special procedures by Monte Carlo methods.

    PubMed

    Metzger, R L; Van Riper, K A

    1999-08-01

    The assessment of fetal dose from a special procedure in the clinical environment is difficult as patient size, fluoroscopic beam motion, and imaging sequences vary significantly from study to study. Fetal dose is particularly difficult to estimate when the fetus is exposed partially or totally to scatter radiation from images taken in other locations of the mother's body. A method to reliably estimate fetal dose has been developed by using template based input files for the Monte Carlo radiation transport code MCNP. Female patient phantoms at 0, 3, 6, and 9 months of pregnancy and source terms for common diagnostic tube potentials are used to rapidly build an input file for MCNP. The phantoms can be easily modified to fit patient shape. The geometry and beam location for each type of image acquired (i.e. fluoroscopy, spot filming, etc.) is verified by the use of a 3D visualization code (Sabrina). MCNP is then run to estimate the dose to the embryo/fetus and the exposure to skin entrance (ESE) for the beam being modeled. The actual ESE for the beam is then measured with ion chambers and the fetal dose is determined from the MCNP supplied ratio of ESE to fetal dose. Runs are made for each type of imaging and the doses are summed for the total fetal dose. For most procedures, the method can provide an estimate of the fetal dose within one day of the study. The method can also be used to prospectively model a study in order to choose imaging sequences that will minimize fetal dose.

  2. Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico.

    PubMed

    Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

    2015-09-30

    Determining ionizing radiation in a geographic area serves to assess its effects on a population's health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h(-1). At the same sites, 48 soil samples were taken to obtain the activity concentrations of (226)Ra, (232)Th and (40)K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h(-1). Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg(-1), for (226)Ra, (232)Th and (40)K, respectively. From the analysis, the spatial distribution of (232)Th, (226)Ra and (40)K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

  3. (Considerations of beta and electron transport in internal dose calculations): (Progress report)

    SciTech Connect

    Poston, J.W.

    1989-01-01

    This task involved use of the code INDOSE-EGS for calculation of S-values for radionuclides of importance in nuclear medicine. This task was proposed to proceed in a logical fashion as outlined below: identification of radionuclides for which more refined dose estimates are required; identification of the target and source combinations for which the previous assumption is clearly invalid; production of a base of data for monoenergetic radiations with sufficient accuracy to be used in dose calculations; calculation of revised dose estimates, i.e., S-values. The extension of this code to include head and neck models, gall bladder models, and kidney models are discussed. 2 refs.

  4. Assessment of secondhand smoke in international airports in Thailand, 2013.

    PubMed

    Kungskulniti, Nipapun; Charoenca, Naowarut; Peesing, Jintana; Trangwatana, Songwut; Hamann, Stephen; Pitayarangsarit, Siriwan; Chitanondh, Hatai

    2015-11-01

    To assess secondhand smoke (SHS) exposure in Thai international airports using a fine particulate indicator, particulate matter ≤2.5 μm (PM2.5), and to compare with 2012 exposure findings in international airports in the USA. Smoking rooms in the four largest international airports that serve the most travellers and with the most operating designated smoking rooms (DSRs) were monitored using PM2.5 monitoring equipment following an approved research protocol for assessing fine particle pollution from tobacco smoke. Monitoring was conducted inside and just outside DSRs and throughout the airport terminals in all four airports. Altogether 104 samples were taken to assess SHS exposure in four airports. Simultaneous samples were taken multiple times in a total of 11 DSRs available for sampling in the research period. Levels of PM2.5 in DSRs were extremely high in all four airports and were more dangerous inside DSRs than in the US airports (overall mean=532.5 vs 188.7 µg/m(3)), higher outside DSRs than in the US airports (overall mean=50.1 vs 43.7 µg/m(3)), and at comparable levels with the US airports in the terminals away from DSRs (overall mean=13.8 vs 11.5 µg/m(3). Findings show that travellers and employees in or near DSRs in the airports assessed in Thailand are being exposed to even higher levels of SHS than in US airports that still have DSRs. Extremely high levels of SHS in and adjacent to DSR show that these rooms are not providing safe air quality for employees and travellers. These high levels of exposure are above those levels reported in US airports and show the need for remedial action to ensure safe air quality in international airports in Thailand. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  5. INFOMAT: The international materials assessment and application centre's internet gateway

    NASA Astrophysics Data System (ADS)

    Branquinho, Carmen Lucia; Colodete, Leandro Tavares

    2004-08-01

    INFOMAT is an electronic directory structured to facilitate the search and retrieval of materials science and technology information sources. Linked to the homepage of the International Materials Assessment and Application Centre, INFOMAT presents descriptions of 392 proprietary databases with links to their host systems as well as direct links to over 180 public domain databases and over 2,400 web sites. Among the web sites are associations/unions, governmental and non-governmental institutions, industries, library holdings, market statistics, news services, on-line publications, standardization and intellectual property organizations, and universities/research groups.

  6. Effect of Low-Dose MDCT and Iterative Reconstruction on Trabecular Bone Microstructure Assessment

    PubMed Central

    Baum, Thomas; Nasirudin, Radin A.; Mei, Kai; Garcia, Eduardo G.; Burgkart, Rainer; Rummeny, Ernst J.; Kirschke, Jan S.; Noël, Peter B.

    2016-01-01

    We investigated the effects of low-dose multi detector computed tomography (MDCT) in combination with statistical iterative reconstruction algorithms on trabecular bone microstructure parameters. Twelve donated vertebrae were scanned with the routine radiation exposure used in our department (standard-dose) and a low-dose protocol. Reconstructions were performed with filtered backprojection (FBP) and maximum-likelihood based statistical iterative reconstruction (SIR). Trabecular bone microstructure parameters were assessed and statistically compared for each reconstruction. Moreover, fracture loads of the vertebrae were biomechanically determined and correlated to the assessed microstructure parameters. Trabecular bone microstructure parameters based on low-dose MDCT and SIR significantly correlated with vertebral bone strength. There was no significant difference between microstructure parameters calculated on low-dose SIR and standard-dose FBP images. However, the results revealed a strong dependency on the regularization strength applied during SIR. It was observed that stronger regularization might corrupt the microstructure analysis, because the trabecular structure is a very small detail that might get lost during the regularization process. As a consequence, the introduction of SIR for trabecular bone microstructure analysis requires a specific optimization of the regularization parameters. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods. PMID:27447827

  7. Effect of low-dose CT and iterative reconstruction on trabecular bone microstructure assessment

    NASA Astrophysics Data System (ADS)

    Kopp, Felix K.; Baum, Thomas; Nasirudin, Radin A.; Mei, Kai; Garcia, Eduardo G.; Burgkart, Rainer; Rummeny, Ernst J.; Bauer, Jan S.; Noël, Peter B.

    2016-03-01

    The trabecular bone microstructure is an important factor in the development of osteoporosis. It is well known that its deterioration is one effect when osteoporosis occurs. Previous research showed that the analysis of trabecular bone microstructure enables more precise diagnoses of osteoporosis compared to a sole measurement of the mineral density. Microstructure parameters are assessed on volumetric images of the bone acquired either with high-resolution magnetic resonance imaging, high-resolution peripheral quantitative computed tomography or high-resolution computed tomography (CT), with only CT being applicable to the spine, which is one of clinically most relevant fracture sites. However, due to the high radiation exposure for imaging the whole spine these measurements are not applicable in current clinical routine. In this work, twelve vertebrae from three different donors were scanned with standard and low radiation dose. Trabecular bone microstructure parameters were assessed for CT images reconstructed with statistical iterative reconstruction (SIR) and analytical filtered backprojection (FBP). The resulting structure parameters were correlated to the biomechanically determined fracture load of each vertebra. Microstructure parameters assessed for low-dose data reconstructed with SIR significantly correlated with fracture loads as well as parameters assessed for standard-dose data reconstructed with FBP. Ideal results were achieved with low to zero regularization strength yielding microstructure parameters not significantly different from those assessed for standard-dose FPB data. Moreover, in comparison to other approaches, superior noise-resolution trade-offs can be found with the proposed methods.

  8. Awareness and knowledge among internal medicine house-staff for dose adjustment of commonly used medications in patients with CKD.

    PubMed

    Surana, Sikander; Kumar, Neeru; Vasudeva, Amita; Shaikh, Gulvahid; Jhaveri, Kenar D; Shah, Hitesh; Malieckal, Deepa; Fogel, Joshua; Sidhu, Gurwinder; Rubinstein, Sofia

    2017-01-17

    Drug dosing errors result in adverse patient outcomes and are more common in patients with chronic kidney disease (CKD). As internists treat the majority of patients with CKD, we study if Internal Medicine house-staff have awareness and knowledge about the correct dosage of commonly used medications for those with CKD. A cross-sectional survey was performed and included 341 participants. The outcomes were the awareness of whether a medication needs dose adjustment in patients with CKD and whether there was knowledge for the level of glomerular filtration rate (GFR) a medication needs to be adjusted. The overall pattern for all post-graduate year (PGY) groups in all medication classes was a lack of awareness and knowledge. For awareness, there were statistically significant increased mean differences for PGY2 and PGY3 as compared to PGY1 for allergy, endocrine, gastrointestinal, and rheumatologic medication classes but not for analgesic, cardiovascular, and neuropsychotropic medication classes. For knowledge, there were statistically significant increased mean differences for PGY2 and PGY3 as compared to PGY1 for allergy, cardiovascular, endocrine, and gastrointestinal, medication classes but not for analgesic, neuropsychotropic, and rheumatologic medication classes. Internal Medicine house-staff across all levels of training demonstrated poor awareness and knowledge for many medication classes in CKD patients. Internal Medicine house-staff should receive more nephrology exposure and formal didactic educational training during residency to better manage complex treatment regimens and prevent medication dosing errors.

  9. 76 FR 53847 - New International Commission on Radiological Protection; Recommendations on the Annual Dose Limit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ... REIRS database (NUREG-0713, ``Occupational Radiation Exposure at Commercial Nuclear Power Reactors and... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY... Annual Dose Limit to the Lens of the Eye AGENCY: Nuclear Regulatory Commission. ACTION: Request...

  10. Dose assessment following an overexposure of a worker at a Swiss nuclear power plant.

    PubMed

    Bailat, Claude J; Laedermann, Jean-Pascal; Baechler, Sébastien; Desorgher, Laurent; Aroua, Abbas; Bochud, François O

    2017-07-27

    The aim of this work was to assess the doses received by a diver exposed to a radiation source during maintenance work in the fuel transfer pool at a Swiss nuclear power plant, and to define whether the statutory limit was breached or not. Onsite measurements were carried out and different scenarios were simulated using the MicroShield Software and the MCNPX Monte Carlo radiation transport code to estimate the activity of the irradiating object as well as the doses to the limbs and the effective dose delivered to the operator. The activity of the object was estimated to 1.8 TBq. From the various dose estimations, a conservative value of 7.5 Sv was proposed for the equivalent dose to the skin on the hands and an effective dose of 28 mSv. The use of different experimental and calculation methods allowed us to accurately estimate the activity of the object and the dose delivered to the diver, useful information for making a decision on the most appropriate scheme of follow up for the patient.

  11. A A field test for extremity dose assessment during outages at Korean nuclear power plants.

    PubMed

    Kim, Hee Geun; Kong, Tae Young

    2013-05-01

    During maintenance on the water chamber of a steam generator, the pressuriser heater and the pressure tube feeder in nuclear power plants, workers are likely to receive high radiation doses due to the severe workplace conditions. In particular, it is expected that workers' hands would receive the highest radiation doses because of their contact with the radioactive materials. In this study, field tests for extremity dose assessments in radiation workers undertaking contact tasks with high radiation doses were conducted during outages at pressurised water reactors and pressurised heavy water reactors in Korea. In the test, the radiation workers were required to wear additional thermoluminescent dosemeters (TLDs) on their backs and wrists and an extremity dosemeter on the finger, as well as a main TLD on the chest while performing the maintenance tasks.

  12. Preliminary Assessment of ICRP Dose Conversion Factor Recommendations for Accident Analysis Applications

    SciTech Connect

    Vincent, A.M.

    2002-03-13

    Accident analysis for U.S. Department of Energy (DOE) nuclear facilities is an integral part of the overall safety basis developed by the contractor to demonstrate facility operation can be conducted safely. An appropriate documented safety analysis for a facility discusses accident phenomenology, quantifies source terms arising from postulated process upset conditions, and applies a standardized, internationally-recognized database of dose conversion factors (DCFs) to evaluate radiological conditions to offsite receptors.

  13. Comprehensive assessment of radiation dose estimates for the CORE320 study.

    PubMed

    Rybicki, Frank J; Mather, Richard T; Kumamaru, Kanako K; Brinker, Jeffrey; Chen, Marcus Y; Cox, Christopher; Matheson, Matthew B; Dewey, Marc; DiCarli, Marcelo F; Miller, Julie M; Geleijns, Jacob; George, Richard T; Paul, Narinder; Texter, John; Vavere, Andrea; Yaw, Tan Swee; Lima, Joao A C; Clouse, Melvin E

    2015-01-01

    OBJECTIVE. The purpose of this study was to comprehensively study estimated radiation doses for subjects included in the main analysis of the Combined Non-invasive Coronary Angiography and Myocardial Perfusion Imaging Using 320 Detector Computed Tomography (CORE320) study ( ClinicalTrials.gov identifier NCT00934037), a clinical trial comparing combined CT angiography (CTA) and perfusion CT with the reference standard catheter angiography plus myocardial perfusion SPECT. SUBJECTS AND METHODS. Prospectively acquired data on 381 CORE320 subjects were analyzed in four groups of testing related to radiation exposure. Radiation dose estimates were compared between modalities for combined CTA and perfusion CT with respect to covariates known to influence radiation exposure and for the main clinical outcomes defined by the trial. The final analysis assessed variations in radiation dose with respect to several factors inherent to the trial. RESULTS. The mean radiation dose estimate for the combined CTA and perfusion CT protocol (8.63 mSv) was significantly (p < 0.0001 for both) less than the average dose delivered from SPECT (10.48 mSv) and the average dose from diagnostic catheter angiography (11.63 mSv). There was no significant difference in estimated CTA-perfusion CT radiation dose for subjects who had false-positive or false-negative results in the CORE320 main analyses in a comparison with subjects for whom the CTA-perfusion CT findings were in accordance with the reference standard SPECT plus catheter angiographic findings. CONCLUSION. Radiation dose estimates from CORE320 support clinical implementation of a combined CT protocol for assessing coronary anatomy and myocardial perfusion.

  14. Revisions to US EPA Superfund Risk and Dose Assessment Models and Guidance - 13403

    SciTech Connect

    Walker, Stuart A.

    2013-07-01

    The U.S. Environmental Protection Agency (EPA) Superfund program's six Preliminary Remediation Goal (PRG) and Dose Compliance Concentration (DCC) internet based calculators for risk and dose assessment at Superfund sites are being revised to reflect better science, revisions to existing exposure scenarios and new scenarios, and changes to match up more closely with the EPA chemical regional screening level calculator. A revised version of the 1999 guidance document that provides an overview for the Superfund risk assessment process at radioactively contaminated sites, 'Radiation Risk Assessment At CERCLA Sites: Q and A', is being completed that will reflect Superfund recommended guidance and other technical documents issued over the past 13 years. EPA is also issuing a series of fact sheets in the document 'Superfund Radiation Risk Assessment: A Community Tool-kit'. This presentation would go over those changes that are expected to be finished by this spring. (authors)

  15. Doses to internal organs for various breast radiation techniques--implications on the risk of secondary cancers and cardiomyopathy.

    PubMed

    Pignol, Jean-Philippe; Keller, Brian M; Ravi, Ananth

    2011-01-14

    Breast cancers are more frequently diagnosed at an early stage and currently have improved long term outcomes. Late normal tissue complications induced by adjuvant radiotherapy like secondary cancers or cardiomyopathy must now be avoided at all cost. Several new breast radiotherapy techniques have been developed and this work aims at comparing the scatter doses of internal organs for those techniques. A CT-scan of a typical early stage left breast cancer patient was used to describe a realistic anthropomorphic phantom in the MCNP Monte Carlo code. Dose tally detectors were placed in breasts, the heart, the ipsilateral lung, and the spleen. Five irradiation techniques were simulated: whole breast radiotherapy 50 Gy in 25 fractions using physical wedge or breast IMRT, 3D-CRT partial breast radiotherapy 38.5 Gy in 10 fractions, HDR brachytherapy delivering 34 Gy in 10 treatments, or Permanent Breast 103Pd Seed Implant delivering 90 Gy. For external beam radiotherapy the wedge compensation technique yielded the largest doses to internal organs like the spleen or the heart, respectively 2,300 mSv and 2.7 Gy. Smaller scatter dose are induced using breast IMRT, respectively 810 mSv and 1.1 Gy, or 3D-CRT partial breast irradiation, respectively 130 mSv and 0.7 Gy. Dose to the lung is also smaller for IMRT and 3D-CRT compared to the wedge technique. For multicatheter HDR brachytherapy a large dose is delivered to the heart, 3.6 Gy, the spleen receives 1,171 mSv and the lung receives 2,471 mSv. These values are 44% higher in case of a balloon catheter. In contrast, breast seeds implant is associated with low dose to most internal organs. The present data support the use of breast IMRT or virtual wedge technique instead of physical wedges for whole breast radiotherapy. Regarding partial breast irradiation techniques, low energy source brachytherapy and external beam 3D-CRT appear safer than 192Ir HDR techniques.

  16. International physical protection self-assessment tool for chemical facilities.

    SciTech Connect

    Tewell, Craig R.; Burdick, Brent A.; Stiles, Linda L.; Lindgren, Eric Richard

    2010-09-01

    This report is the final report for Laboratory Directed Research and Development (LDRD) Project No.130746, International Physical Protection Self-Assessment Tool for Chemical Facilities. The goal of the project was to develop an exportable, low-cost, computer-based risk assessment tool for small to medium size chemical facilities. The tool would assist facilities in improving their physical protection posture, while protecting their proprietary information. In FY2009, the project team proposed a comprehensive evaluation of safety and security regulations in the target geographical area, Southeast Asia. This approach was later modified and the team worked instead on developing a methodology for identifying potential targets at chemical facilities. Milestones proposed for FY2010 included characterizing the international/regional regulatory framework, finalizing the target identification and consequence analysis methodology, and developing, reviewing, and piloting the software tool. The project team accomplished the initial goal of developing potential target categories for chemical facilities; however, the additional milestones proposed for FY2010 were not pursued and the LDRD funding therefore was redirected.

  17. A dose assessment for a U.S. nuclear test site -- Bikini Atoll

    SciTech Connect

    Robison, W.L.; Bogen, K.T.; Conrado, C.L.

    1993-07-01

    On March 1, 1954, a nuclear weapon test, code-named BRAVO, conducted at Bikini Atoll in the northern Marshall Islands contaminated the major residence island. Here the authors provide a radiological dose assessment for the main residence island, Bikini, using extensive radionuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island. The unique composition of coral soil greatly alters the relative contribution of cesium-137 and strontium-90 to the total estimated dose relative to expectations based on North American and European soils. Cesium-137 produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The estimated maximum annual effective dose is 4.4 mSv y{sup {minus}1} when imported foods, which are now an established part of the diet, are available. The 30-, 50-, and 70-y integral effective doses are 10 cSv, 14 cSv, and 16 cSv, respectively. An analysis of interindividual variability in 0- to 30-y expected integral dose indicates that 95% of Bikini residents would have expected doses within a factor of 3.4 above and 4.8 below the population-average value. A corresponding uncertainty analysis showed that after about 5 y of residence, the 95% confidence limits on population-average dose would be {+-}35% of its expected value. The authors have evaluated various countermeasures to reduce {sup 137}Cs in food crops. Treatment with potassium reduces the uptake of {sup 137}Cs into food crops, and therefore the ingestion dose, to less than 10% of pretreatment levels and has essentially no negative environmental consequences.

  18. Assessment of bilateral filter on 1/2-dose chest-pelvis CT views.

    PubMed

    Al-Hinnawi, Abdel Razzak; Daear, Mohammed; Huwaijah, Said

    2013-07-01

    A bilateral filter (BF) is a non-linear filter that has been proved to de-noise images without overrunning edges. Multi-slice computerized tomography (CT) may employ a BF to participate in dose reduction. This paper quantifies the role of the BF in achieving this objective on 1/2-dose CT. Two sets of CT images are acquired for the chest-pelvis at two different radiation doses. The BF was applied on the 1/2-dose CT images by use of various window sizes. Each time, a set of values of the BF range was fixed while the BF domain was modified. The goal was to observe the behavior of the BF on 1/2-dose CT images in comparison with full-dose CT images. The comparison was carried out by use of four co-occurrence matrix descriptors. Additionally, the peak signal-to-noise ratio (PSNR) and the mean square error (MSE) were reported. The study was applied to the sagittal, coronal, and axial CT views. The results showed that the impact of applying a BF varies among different CT views. The BF can retrieve only part of the signal being lost due to reduction of the radiation dose by one half. Yet, the BF improves the appearance of the 1/2-dose chest-pelvis CT examination. Thus, the BF can contribute to a 50% dose reduction. A procedure for employing the BF on CT machines is proposed. The results also showed that texture descriptors are similar to the PSNR and MSE in providing quantities for assessing medical image quality.

  19. Measurements of radioactivity and dose assessments in some building materials in Bitlis, Turkey.

    PubMed

    Kayakökü, Halime; Karatepe, Şule; Doğru, Mahmut

    2016-09-01

    In this study, samples of perlite, pumice and Ahlat stones (Ignimbrite) extracted from mines in Bitlis and samples of other building materials produced in facilities in Bitlis were collected and analyzed. Activity concentrations of (226)Ra, (232)Th and (40)K in samples of building materials were measured using NaI detector (NaI(Tl)) with an efficiency of 24%. The radon measurements of building material samples were determined using CR-39 nuclear track detectors. (226)Ra, (232)Th and (40)K radioactivity concentrations ranged from (29.6±5.9 to 228.2±38.1Bq/kg), (10.8±5.4 to 95.5±26.1Bq/kg) and (249.3±124.7 to 2580.1±266.9Bq/kg), respectively. Radon concentration, radium equivalent activities, absorbed dose rate, excess lifetime cancer risk and the values of hazard indices were calculated for the measured samples to assess the radiation hazards arising from using those materials in the construction of dwellings. Radon concentration ranged between 89.2±12.0Bq/m(3) and 1141.0±225.0Bq/m(3). It was determined that Raeq values of samples conformed to world standards except for perlite and single samples of brick and Ahlat stone. Calculated values of absorbed dose rate ranged from 81.3±20.5 to 420.6±42.8nGy/h. ELCR values ranged from (1.8±0.3)×10(-3) to (9.0±1.0)×10(-3). All samples had ELCR values higher than the world average. The values of Hin and Hex varied from 0.35±0.11 to 1.78±0.18 and from 0.37±0.09 to 1.17±0.13, respectively. The results were compared with standard radioactivity values determined by international organizations and with similar studies. There would be a radiation risk for people living in buildings made of perlite, Ahlat-1 and Brick-3.

  20. Assessing intern core competencies with an objective structured clinical examination.

    PubMed

    Short, Matthew W; Jorgensen, Jennifer E; Edwards, John A; Blankenship, Robert B; Roth, Bernard J

    2009-09-01

    Residents are evaluated using Accreditation Council for Graduate Medical Education (ACGME) core competencies. An Objective Structured Clinical Examination (OSCE) is a potential evaluation tool to measure these competencies and provide outcome data. Create an OSCE to evaluate and demonstrate improvement in intern core competencies of patient care, medical knowledge, practice-based learning and improvement, interpersonal and communication skills, professionalism, and systems-based practice before and after internship. From 2006 to 2008, 106 interns from 10 medical specialties were evaluated with a preinternship and postinternship OSCE at Madigan Army Medical Center. The OSCE included eight 12-minute stations that collectively evaluated the 6 ACGME core competencies using human patient simulators, standardized patients, and clinical scenarios. Interns were scored using objective and subjective criteria, with a maximum score of 100 for each competency. Stations included death notification, abdominal pain, transfusion consent, suture skills, wellness history, chest pain, altered mental status, and computer literature search. These stations were chosen by specialty program directors, created with input from board-certified specialists, and were peer reviewed. All OSCE testing on the 106 interns (ages 25 to 44 [average, 28.6]; 70 [66%] men; 65 [58%] allopathic medical school graduates) resulted in statistically significant improvement in all ACGME core competencies: patient care (71.9% to 80.0%, P < .001), medical knowledge (59.6% to 78.6%, P < .001), practice-based learning and improvement (45.2% to 63.0%, P < .001), interpersonal and communication skills (77.5% to 83.1%, P < .001), professionalism (74.8% to 85.1%, P < .001), and systems-based practice (56.6% to 76.5%, P < .001). An OSCE during internship can evaluate incoming baseline ACGME core competencies and test for interval improvement. The OSCE is a valuable assessment tool to provide

  1. Toward a Molecular Equivalent Dose: Use of the Medaka Model in Comparative Risk Assessment.

    EPA Science Inventory

    Recent challenges in risk assessment underscore the need to compare the results of toxicity and dose-response testing among a growing list of animal models and, possibly, an array of in vitro screening assays. Assays that quantify types of DNA damage that are directly relevant to...

  2. Toward a Molecular Equivalent Dose: Use of the Medaka Model in Comparative Risk Assessment.

    EPA Science Inventory

    Recent challenges in risk assessment underscore the need to compare the results of toxicity and dose-response testing among a growing list of animal models and, possibly, an array of in vitro screening assays. Assays that quantify types of DNA damage that are directly relevant to...

  3. Toxicokinetics to identify nonlinearities in dose-response and implications for risk assessment

    EPA Science Inventory

    For presentation at the 45th Annual Symposium of the Society of Toxicology of Canada. The meeting will be held on 4-5 December 2013 at the Ottawa Convention Centre. Toxicokinetics to identify nonlinearities in dose-response and implications for risk assessment. Rory Conolly, Offi...

  4. RESPIRATORY DOSE TO SUSCEPTIBLE POPULATIONS ASSESSED BY EXPOSURE AND DOSIMETRY STUDIES

    EPA Science Inventory

    Respiratory Dose to Susceptible Populations Assessed by Exposure and Dosimetry Studies

    Chong Kim1 and Ronald Williams2, 1USEPA National Health and Environmental Effects Research Laboratory and 2USEPA National Exposure Research Laboratory, RTP, NC.

    Rationale: Parti...

  5. RESPIRATORY DOSE TO SUSCEPTIBLE POPULATIONS ASSESSED BY EXPOSURE AND DOSIMETRY STUDIES

    EPA Science Inventory

    Respiratory Dose to Susceptible Populations Assessed by Exposure and Dosimetry Studies

    Chong Kim1 and Ronald Williams2, 1USEPA National Health and Environmental Effects Research Laboratory and 2USEPA National Exposure Research Laboratory, RTP, NC.

    Rationale: Parti...

  6. Toward a molecular equivalent dose: use of the medaka model in comparative risk assessment

    EPA Science Inventory

    Recent challenges in risk assessment underscore the need to compare the results of toxicity and dose-response testing among a growing list of animal models and, possibly, an array of in vitro screening assays. Assays that quantify types of DNA damage that are directly relevant to...

  7. Transcriptomic Dose-Response Analysis for Mode of Action and Risk Assessment

    EPA Science Inventory

    Microarray and RNA-seq technologies can play an important role in assessing the health risks associated with environmental exposures. The utility of gene expression data to predict hazard has been well documented. Early toxicogenomics studies used relatively high, single doses w...

  8. Transcriptomic Dose-Response Analysis for Mode of Action and Risk Assessment

    EPA Science Inventory

    Microarray and RNA-seq technologies can play an important role in assessing the health risks associated with environmental exposures. The utility of gene expression data to predict hazard has been well documented. Early toxicogenomics studies used relatively high, single doses w...

  9. Toxicokinetics to identify nonlinearities in dose-response and implications for risk assessment

    EPA Science Inventory

    For presentation at the 45th Annual Symposium of the Society of Toxicology of Canada. The meeting will be held on 4-5 December 2013 at the Ottawa Convention Centre. Toxicokinetics to identify nonlinearities in dose-response and implications for risk assessment. Rory Conolly, Offi...

  10. Toward a molecular equivalent dose: use of the medaka model in comparative risk assessment

    EPA Science Inventory

    Recent challenges in risk assessment underscore the need to compare the results of toxicity and dose-response testing among a growing list of animal models and, possibly, an array of in vitro screening assays. Assays that quantify types of DNA damage that are directly relevant to...

  11. Radiological dose assessments in the northern Marshall Islands (1989--1991). Revision

    SciTech Connect

    Sun, L.C.; Meinhold, C.B.; Moorthy, A.R.; Clinton, J.H.; Kaplan, E.

    1991-11-01

    The Republic of the Marshall Islands (RMI) is located in the central Pacific Ocean about 3500 km southwest of Hawaii and 4500 km east of Manila, Philippines. It consists of 34 atolls and 2 coral islands, having a total land area of about 180 km{sup 2}, distributed over more than 2.5 {times} 10{sup 6} of ocean. Between 1946 and 1958 the United states conducted nuclear tests there: 43 at Enewetak and 23 at Bikini. Thirty-three years after the cessation of nuclear testing in the RMI, the impact of these operations on the health and radiological safety of the people living in or planning to return to their contaminated homelands is still an important concern. The present Brookhaven National Laboratory (BNL) Marshall Islands Radiological Safety Program (MIRSP) began in 1987 with funding from the US Department of Energy (DOE). The objectives of the MIRSP are to determine the radionuclides present in the bodies of those people potentially exposed to residual radionuclide from weapon tests and fallout, and to assess their present and lifetime dose from external and internal sources. Field bioassay missions involving whole-body counting (WBC) and urine sample collection have, therefore, been important components of the program. WBC is used to measure {gamma}-emitters, such as {sup 40}K, {sup 60}Co and {sup 137}Cs, present in individuals. Urine samples are used to measure {alpha} and {beta}-emitting nuclides such as {sup 239}Pu and {sup 90}Sr, that are undetectable by WBC routine methods.

  12. Radiological dose assessments in the northern Marshall Islands (1989--1991)

    SciTech Connect

    Sun, L.C.; Meinhold, C.B.; Moorthy, A.R.; Clinton, J.H.; Kaplan, E.

    1991-12-01

    The Republic of the Marshall Islands (RMI) is located in the central Pacific Ocean about 3500 km southeast of Hawaii and 4500 km east of Manila, Philippines. It consists of 34 atolls and 2 coral island, having a total land area of about 180 km{sup 2}, distributed over more than 2.5 {times} 10{sup 6} km{sup 2} of ocean. Between 1946 and 1958 the United States conducted nuclear tests there: 43 at Enewetak and 23 at Bikini. Thirty-three years after the cessation of nuclear testing in the RMI, the impact of these operations on the health and radiological safety of the people living in or planing to return to their contaminated homelands is still an important concern. The present Brookhaven National Laboratory (BNL) Marshall Islands Radiological Safety Program (MIRSP) began in 1987 with funding from the US Department of Energy (DOE). The objectives of the MIRSP are to determine the radionuclides present in the bodies of those people potentially exposed to residual radionuclide from weapon tests and fallout, and to assess their present and lifetime dose from external and internal sources. Field bioassay missions involving whole-body counting (WBC) and urine sample collection have, therefore, been important components of the program. WBC is used to measure {gamma}-emitters, such as {sup 40}K, {sup 60}Co and {sup 137}Cs, present in individuals. Urine samples are used to measure {alpha} and {beta}-emitting nuclides, such as {sup 239}Pu and {sup 90}Sr, that are undetectable by WBC routine methods. 6 refs.

  13. Radiological dose assessments in the northern Marshall Islands (1989--1991). Revision

    SciTech Connect

    Sun, L.C.; Meinhold, C.B.; Moorthy, A.R.; Clinton, J.H.; Kaplan, E.

    1991-12-01

    The Republic of the Marshall Islands (RMI) is located in the central Pacific Ocean about 3500 km southeast of Hawaii and 4500 km east of Manila, Philippines. It consists of 34 atolls and 2 coral island, having a total land area of about 180 km{sup 2}, distributed over more than 2.5 {times} 10{sup 6} km{sup 2} of ocean. Between 1946 and 1958 the United States conducted nuclear tests there: 43 at Enewetak and 23 at Bikini. Thirty-three years after the cessation of nuclear testing in the RMI, the impact of these operations on the health and radiological safety of the people living in or planing to return to their contaminated homelands is still an important concern. The present Brookhaven National Laboratory (BNL) Marshall Islands Radiological Safety Program (MIRSP) began in 1987 with funding from the US Department of Energy (DOE). The objectives of the MIRSP are to determine the radionuclides present in the bodies of those people potentially exposed to residual radionuclide from weapon tests and fallout, and to assess their present and lifetime dose from external and internal sources. Field bioassay missions involving whole-body counting (WBC) and urine sample collection have, therefore, been important components of the program. WBC is used to measure {gamma}-emitters, such as {sup 40}K, {sup 60}Co and {sup 137}Cs, present in individuals. Urine samples are used to measure {alpha} and {beta}-emitting nuclides, such as {sup 239}Pu and {sup 90}Sr, that are undetectable by WBC routine methods. 6 refs.

  14. Radiological dose assessments in the northern Marshall Islands (1989--1991)

    SciTech Connect

    Sun, L.C.; Meinhold, C.B.; Moorthy, A.R.; Clinton, J.H.; Kaplan, E.

    1991-11-01

    The Republic of the Marshall Islands (RMI) is located in the central Pacific Ocean about 3500 km southwest of Hawaii and 4500 km east of Manila, Philippines. It consists of 34 atolls and 2 coral islands, having a total land area of about 180 km{sup 2}, distributed over more than 2.5 {times} 10{sup 6} of ocean. Between 1946 and 1958 the United states conducted nuclear tests there: 43 at Enewetak and 23 at Bikini. Thirty-three years after the cessation of nuclear testing in the RMI, the impact of these operations on the health and radiological safety of the people living in or planning to return to their contaminated homelands is still an important concern. The present Brookhaven National Laboratory (BNL) Marshall Islands Radiological Safety Program (MIRSP) began in 1987 with funding from the US Department of Energy (DOE). The objectives of the MIRSP are to determine the radionuclides present in the bodies of those people potentially exposed to residual radionuclide from weapon tests and fallout, and to assess their present and lifetime dose from external and internal sources. Field bioassay missions involving whole-body counting (WBC) and urine sample collection have, therefore, been important components of the program. WBC is used to measure {gamma}-emitters, such as {sup 40}K, {sup 60}Co and {sup 137}Cs, present in individuals. Urine samples are used to measure {alpha} and {beta}-emitting nuclides such as {sup 239}Pu and {sup 90}Sr, that are undetectable by WBC routine methods.

  15. Clinical evaluation of a dose monitoring software tool based on Monte Carlo Simulation in assessment of eye lens doses for cranial CT scans.

    PubMed

    Guberina, Nika; Suntharalingam, Saravanabavaan; Naßenstein, Kai; Forsting, Michael; Theysohn, Jens; Wetter, Axel; Ringelstein, Adrian

    2016-10-01

    The aim of this study was to verify the results of a dose monitoring software tool based on Monte Carlo Simulation (MCS) in assessment of eye lens doses for cranial CT scans. In cooperation with the Federal Office for Radiation Protection (Neuherberg, Germany), phantom measurements were performed with thermoluminescence dosimeters (TLD LiF:Mg,Ti) using cranial CT protocols: (I) CT angiography; (II) unenhanced, cranial CT scans with gantry angulation at a single and (III) without gantry angulation at a dual source CT scanner. Eye lens doses calculated by the dose monitoring tool based on MCS and assessed with TLDs were compared. Eye lens doses are summarized as follows: (I) CT angiography (a) MCS 7 mSv, (b) TLD 5 mSv; (II) unenhanced, cranial CT scan with gantry angulation, (c) MCS 45 mSv, (d) TLD 5 mSv; (III) unenhanced, cranial CT scan without gantry angulation (e) MCS 38 mSv, (f) TLD 35 mSv. Intermodality comparison shows an inaccurate calculation of eye lens doses in unenhanced cranial CT protocols at the single source CT scanner due to the disregard of gantry angulation. On the contrary, the dose monitoring tool showed an accurate calculation of eye lens doses at the dual source CT scanner without gantry angulation and for CT angiography examinations. The dose monitoring software tool based on MCS gave accurate estimates of eye lens doses in cranial CT protocols. However, knowledge of protocol and software specific influences is crucial for correct assessment of eye lens doses in routine clinical use.

  16. VARSKIN MOD 2 and SADDE MOD2: Computer codes for assessing skin dose from skin contamination

    SciTech Connect

    Durham, J.S. )

    1992-12-01

    The computer code VARSKIN has been modified to calculate dose to skin from three-dimensional sources, sources separated from the skin by layers of protective clothing, and gamma dose from certain radionuclides correction for backscatter has also been incorporated for certain geometries. This document describes the new code, VARSKIN Mod 2, including installation and operation instructions, provides detailed descriptions of the models used, and suggests methods for avoiding misuse of the code. The input data file for VARSKIN Mod 2 has been modified to reflect current physical data, to include the contribution to dose from internal conversion and Auger electrons, and to reflect a correction for low-energy electrons. In addition, the computer code SADDE: Scaled Absorbed Dose Distribution Evaluator has been modified to allow the generation of scaled absorbed dose distributions for mixtures of radionuclides and intereat conversion and Auger electrons. This new code, SADDE Mod 2, is also described in this document. Instructions for installation and operation of the code and detailed descriptions of the models used in the code are provided.

  17. On the role of "internal variability" on soil erosion assessment

    NASA Astrophysics Data System (ADS)

    Kim, Jongho; Ivanov, Valeriy; Fatichi, Simone

    2017-04-01

    Empirical data demonstrate that soil loss is highly non-unique with respect to meteorological or even runoff forcing and its frequency distributions exhibit heavy tails. However, all current erosion assessments do not describe the large associated uncertainties of temporal erosion variability and make unjustified assumptions by relying on central tendencies. Thus, the predictive skill of prognostic models and reliability of national-scale assessments have been repeatedly questioned. In this study, we attempt to reveal that the high variability in soil losses can be attributed to two sources: (1) 'external variability' referring to the uncertainties originating at macro-scale, such as climate, topography, and land use, which has been extensively studied; (2) 'geomorphic internal variability' referring to the micro-scale variations of pedologic properties (e.g., surface erodibility in soils with multi-sized particles), hydrologic properties (e.g., soil structure and degree of saturation), and hydraulic properties (e.g., surface roughness and surface topography). Using data and a physical hydraulic, hydrologic, and erosion and sediment transport model, we show that the geomorphic internal variability summarized by spatio-temporal variability in surface erodibility properties is a considerable source of uncertainty in erosion estimates and represents an overlooked but vital element of geomorphic response. The conclusion is that predictive frameworks of soil erosion should embed stochastic components together with deterministic assessments, if they do not want to largely underestimate uncertainty. Acknowledgement: This study was supported by the Basic Science Research Program of the National Research Foundation of Korea funded by the Ministry of Education (2016R1D1A1B03931886).

  18. [Spatial distribution of local absorbed doses inside the Russian segment of the International Space Station].

    PubMed

    Bondarenko, V A; Mitrikas, V G; Tsetlin, V V

    2011-01-01

    The article discusses the procedure of operational radiation safety monitoring with the use of portable Pille-MKS dosimeters, presents the results of ISS dose measurements from September 22, 2003 (after Pille deployment on board the ISS) to March 16, 2011 (completion of the ISS-25 mission). The necessity of continuous dynamic tracking of the radiation environment in ISS compartments arises from the character and uniqueness of space ionizing radiation effects on crew. Radiation loading in the ISS compartments was analyzed and results of using different dosimeters were compared. Experimental radiation studies of the ISS piloted compartments are needed for reliable prediction of doses for the crew that still defy precise estimation.

  19. Radioactivity in food and the environment: calculations of UK radiation doses using integrated assessment methods.

    PubMed

    Camplin, W C; Brownless, G P; Round, G D; Winpenny, K; Hunt, G J

    2002-12-01

    A new method for estimating radiation doses to UK critical groups is proposed for discussion. Amongst others, the Food Standards Agency (FSA) and the Scottish Environment Protection Agency (SEPA) undertake surveillance of UK food and the environment as a check on the effect of discharges of radioactive wastes. Discharges in gaseous and liquid form are made under authorisation by the Environment Agency and SEPA under powers in the Radioactive Substance Act. Results of surveillance by the FSA and SEPA are published in the Radioactivity in Food and the Environment (RIFE) report series. In these reports, doses to critical groups are normally estimated separately for gaseous and liquid discharge pathways. Simple summation of these doses would tend to overestimate doses actually received. Three different methods of combining the effects of both types of discharge in an integrated assessment are considered and ranked according to their ease of application, transparency, scientific rigour and presentational issues. A single integrated assessment method is then chosen for further study. Doses are calculated for surveillance data for the calendar year 2000 and compared with those from the existing RIFE method.

  20. A user friendly database for use in ALARA job dose assessment

    SciTech Connect

    Zodiates, A.M.; Willcock, A.

    1995-03-01

    The pressurized water reactor (PWR) design chosen for adoption by Nuclear Electric plc was based on the Westinghouse Standard Nuclear Unit Power Plant (SNUPPS). This design was developed to meet the United Kingdom requirements and these improvements are embodied in the Sizewell B plant which will start commercial operation in 1994. A user-friendly database was developed to assist the station in the dose and ALARP assessments of the work expected to be carried out during station operation and outage. The database stores the information in an easily accessible form and enables updating, editing, retrieval, and searches of the information. The database contains job-related information such as job locations, number of workers required, job times, and the expected plant doserates. It also contains the means to flag job requirements such as requirements for temporary shielding, flushing, scaffolding, etc. Typical uses of the database are envisaged to be in the prediction of occupational doses, the identification of high collective and individual dose jobs, use in ALARP assessments, setting of dose targets, monitoring of dose control performance, and others.

  1. Deterministic vs. probabilistic analyses to identify sensitive parameters in dose assessment using RESRAD.

    PubMed

    Kamboj, Sunita; Cheng, Jing-Jy; Yu, Charley

    2005-05-01

    The dose assessments for sites containing residual radioactivity usually involve the use of computer models that employ input parameters describing the physical conditions of the contaminated and surrounding media and the living and consumption patterns of the receptors in analyzing potential doses to the receptors. The precision of the dose results depends on the precision of the input parameter values. The identification of sensitive parameters that have great influence on the dose results would help set priorities in research and information gathering for parameter values so that a more precise dose assessment can be conducted. Two methods of identifying site-specific sensitive parameters, deterministic and probabilistic, were compared by applying them to the RESRAD computer code for analyzing radiation exposure for a residential farmer scenario. The deterministic method has difficulty in evaluating the effect of simultaneous changes in a large number of input parameters on the model output results. The probabilistic method easily identified the most sensitive parameters, but the sensitivity measure of other parameters was obscured. The choice of sensitivity analysis method would depend on the availability of site-specific data. Generally speaking, the deterministic method would identify the same set of sensitive parameters as the probabilistic method when 1) the baseline values used in the deterministic method were selected near the mean or median value of each parameter and 2) the selected range of parameter values used in the deterministic method was wide enough to cover the 5th to 95th percentile values from the distribution of that parameter.

  2. Toward Increasing Fairness in Score Scale Calibrations Employed in International Large-Scale Assessments

    ERIC Educational Resources Information Center

    Oliveri, Maria Elena; von Davier, Matthias

    2014-01-01

    In this article, we investigate the creation of comparable score scales across countries in international assessments. We examine potential improvements to current score scale calibration procedures used in international large-scale assessments. Our approach seeks to improve fairness in scoring international large-scale assessments, which often…

  3. 49 CFR 192.927 - What are the requirements for using Internal Corrosion Direct Assessment (ICDA)?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Corrosion Direct Assessment (ICDA)? 192.927 Section 192.927 Transportation Other Regulations Relating to... Internal Corrosion Direct Assessment (ICDA)? (a) Definition. Internal Corrosion Direct Assessment (ICDA) is... on the locations in covered segments where internal corrosion is most likely to exist. The...

  4. 49 CFR 192.927 - What are the requirements for using Internal Corrosion Direct Assessment (ICDA)?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Corrosion Direct Assessment (ICDA)? 192.927 Section 192.927 Transportation Other Regulations Relating to... Internal Corrosion Direct Assessment (ICDA)? (a) Definition. Internal Corrosion Direct Assessment (ICDA) is... on the locations in covered segments where internal corrosion is most likely to exist. The...

  5. 49 CFR 192.927 - What are the requirements for using Internal Corrosion Direct Assessment (ICDA)?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Corrosion Direct Assessment (ICDA)? 192.927 Section 192.927 Transportation Other Regulations Relating to... Internal Corrosion Direct Assessment (ICDA)? (a) Definition. Internal Corrosion Direct Assessment (ICDA) is... on the locations in covered segments where internal corrosion is most likely to exist. The...

  6. 12 CFR 630.5 - Accuracy of reports and assessment of internal control over financial reporting.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... CREDIT SYSTEM General § 630.5 Accuracy of reports and assessment of internal control over financial... assessment of internal control over financial reporting. (1) Annual reports must include a report by the Funding Corporation's management assessing the effectiveness of the internal control over...

  7. Toward Increasing Fairness in Score Scale Calibrations Employed in International Large-Scale Assessments

    ERIC Educational Resources Information Center

    Oliveri, Maria Elena; von Davier, Matthias

    2014-01-01

    In this article, we investigate the creation of comparable score scales across countries in international assessments. We examine potential improvements to current score scale calibration procedures used in international large-scale assessments. Our approach seeks to improve fairness in scoring international large-scale assessments, which often…

  8. Detection and original dose assessment of egg powders subjected to gamma irradiation by using ESR technique

    NASA Astrophysics Data System (ADS)

    Aydın, Talat

    2015-09-01

    ESR (electron spin resonance) techniques were applied for detection and original dose estimation to radiation-processed egg powders. The un-irradiated (control) egg powders showed a single resonance line centered at g=2.0086±0.0005, 2.0081±0.0005, 2.0082±0.0005 (native signal) for yolk, white and whole egg, respectively. Irradiation induced at least one additional intense singlet overlapping to the control signal and caused a significant increase in signal intensity without any changes in spectral patterns. Responses of egg powders to different gamma radiation doses in the range 0-10 kGy were examined. The stability of the radiation-induced ESR signal of irradiated egg powders were investigated over a storage period of about 5 months. Additive reirradiation of the egg powders produces a reproducible dose response function, which can be used to assess the initial dose by back-extrapolation. The additive dose method gives an estimation of the original dose within ±12% at the end of the 720 h storage period.

  9. Monte Carlo Assessments of Absorbed Doses to the Hands of Radiopharmaceutical Workers Due to Photon Emitters

    SciTech Connect

    Ilas, Dan; Eckerman, Keith F; Karagiannis, Harriet

    2009-01-01

    This paper describes the characterization of radiation doses to the hands of nuclear medicine technicians resulting from the handling of radiopharmaceuticals. Radiation monitoring using ring dosimeters indicates that finger dosimeters that are used to show compliance with applicable regulations may overestimate or underestimate radiation doses to the skin depending on the nature of the particular procedure and the radionuclide being handled. To better understand the parameters governing the absorbed dose distributions, a detailed model of the hands was created and used in Monte Carlo simulations of selected nuclear medicine procedures. Simulations of realistic configurations typical for workers handling radiopharmaceuticals were performedfor a range of energies of the source photons. The lack of charged-particle equilibrium necessitated full photon-electron coupled transport calculations. The results show that the dose to different regions of the fingers can differ substantially from dosimeter readings when dosimeters are located at the base of the finger. We tried to identify consistent patterns that relate the actual dose to the dosimeter readings. These patterns depend on the specific work conditions and can be used to better assess the absorbed dose to different regions of the exposed skin.

  10. An assessment of the reliability of dose coefficients for intakes of radionuclides by members of the public.

    PubMed

    Puncher, M

    2014-09-01

    This paper summarises work undertaken on behalf of the Environment Agency for England to quantify uncertainties resulting from internal exposures to a number of radionuclides considered significant because of their anthropogenic origin, namely: (238)U, (226)Ra, (239)Pu, (241)Am, (137)Cs, (90)Sr, (131)I, (129)I and (3)H. Uncertainties in the biokinetic models that are used to calculate the retention and excretion of radionuclides are derived in order to calculate distributions of effective dose per unit intake following their inhalation or ingestion by members of the UK public. The central values and ranges of the distributions are used to inform the derivation of uncertainty factors (UFs) for the different dose coefficients, which can be used to assess reliability. These represent uncertainties inherent in the structures of the biokinetic models and their parameter values. The inferred UF values are typically around 2-3 for ingestion and 2-6 for inhalation for all age groups, and are comparable to UF values inferred from published studies. It is instructive to consider these ranges alongside the likely levels of exposure that are expected from the radionuclides considered (the microsievert range) and the dose limit of planned exposures for members of the public (1000 μSv).

  11. Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models

    SciTech Connect

    Xie, Tianwu; Lee, Choonsik; Bolch, Wesley E.; Zaidi, Habib

    2015-06-15

    Purpose: Nuclear cardiology plays an important role in clinical assessment and has enormous impact on the management of a variety of cardiovascular diseases. Pediatric patients at different age groups are exposed to a spectrum of radiation dose levels and associated cancer risks different from those of adults in diagnostic nuclear medicine procedures. Therefore, comprehensive radiation dosimetry evaluations for commonly used myocardial perfusion imaging (MPI) and viability radiotracers in target population (children and adults) at different age groups are highly desired. Methods: Using Monte Carlo calculations and biological effects of ionizing radiation VII model, we calculate the S-values for a number of radionuclides (Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82) and estimate the absorbed dose and effective dose for 12 MPI radiotracers in computational models including the newborn, 1-, 5-, 10-, 15-yr-old, and adult male and female computational phantoms. Results: For most organs, {sup 201}Tl produces the highest absorbed dose whereas {sup 82}Rb and {sup 15}O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of {sup 82}Rb is 48% and 77% lower than that of {sup 99m}Tc-tetrofosmin (rest), respectively. Conclusions: {sup 82}Rb results in lower effective dose in adults compared to {sup 99m}Tc-labeled tracers. However, this advantage is less apparent in children. The produced dosimetric databases for various radiotracers used in cardiovascular imaging, using new generation of computational models, can be used for risk-benefit assessment of a spectrum of patient population in clinical nuclear cardiology practice.

  12. Assessment of radiation dose in nuclear cardiovascular imaging using realistic computational models

    PubMed Central

    Xie, Tianwu; Lee, Choonsik; Bolch, Wesley E.; Zaidi, Habib

    2015-01-01

    Purpose: Nuclear cardiology plays an important role in clinical assessment and has enormous impact on the management of a variety of cardiovascular diseases. Pediatric patients at different age groups are exposed to a spectrum of radiation dose levels and associated cancer risks different from those of adults in diagnostic nuclear medicine procedures. Therefore, comprehensive radiation dosimetry evaluations for commonly used myocardial perfusion imaging (MPI) and viability radiotracers in target population (children and adults) at different age groups are highly desired. Methods: Using Monte Carlo calculations and biological effects of ionizing radiation VII model, we calculate the S-values for a number of radionuclides (Tl-201, Tc-99m, I-123, C-11, N-13, O-15, F-18, and Rb-82) and estimate the absorbed dose and effective dose for 12 MPI radiotracers in computational models including the newborn, 1-, 5-, 10-, 15-yr-old, and adult male and female computational phantoms. Results: For most organs, 201Tl produces the highest absorbed dose whereas 82Rb and 15O-water produce the lowest absorbed dose. For the newborn baby and adult patient, the effective dose of 82Rb is 48% and 77% lower than that of 99mTc-tetrofosmin (rest), respectively. Conclusions: 82Rb results in lower effective dose in adults compared to 99mTc-labeled tracers. However, this advantage is less apparent in children. The produced dosimetric databases for various radiotracers used in cardiovascular imaging, using new generation of computational models, can be used for risk-benefit assessment of a spectrum of patient population in clinical nuclear cardiology practice. PMID:26127049

  13. Age-dependent dose assessment of 226Ra from bottled water intake.

    PubMed

    Bronzovic, Maja; Marovic, Gordana

    2005-05-01

    Water may present a source of prolonged exposure to naturally occurring radionuclides. One of the most frequently occurring radionuclides in natural mineral and spring waters is 226Ra and its decay products. The contribution of drinking water to the total exposure is very small, at about 5% of the average effective dose attributable annually to natural background radiation, but that exposure contributes to the risk of adverse health consequences. In this study the mean values of 226Ra concentration determined in natural mineral and spring bottled waters range from 6 to 412 mBq L(-1), which is in accord with Croatian legislation. 226Ra effective doses per year from spring water consumption range up to 86 microSv, while 226Ra effective doses per year from mineral water consumption show much higher values. The highest 226Ra effective doses per year from mineral waters consumption, which are up to seven times higher than the dose recommended by WHO (100 microSv), were found in infants and teens. Based on this study, drinking of certain brands of bottled mineral water is not recommended for these age groups because assessed 226Ra effective doses per year exceed the recommended limits. From other research it is known that testosterone appears in elevated concentration during these life periods and affects bone calcification. Therefore, testosterone could affect the retention of 226Ra into the bone. To make more precise conclusions further research is necessary. Adults and especially elderly people are much less susceptible to the presence of 226Ra. According to the results obtained in this study, 226Ra effective doses per year assessed for these age groups were considerably lower (i.e., 10 microSv).

  14. Preliminary assessment of the dose to the interventional radiologist in fluoro-CT-guided procedures.

    PubMed

    Pereira, M F; Alves, J G; Sarmento, S; Santos, J A M; Sousa, M J; Gouvêa, M; Oliveira, A D; Cardoso, J V; Santos, L M

    2011-03-01

    A preliminary assessment of the occupational dose to the intervention radiologist received in fluoroscopy computerised tomography (CT) used to guide the collection of lung and bone biopsies is presented. The main aim of this work was to evaluate the capability of the reading system as well as of the available whole-body (WB) and extremity dosemeters used in routine monthly monitoring periods to measure per procedure dose values. The intervention radiologist was allocated 10 WB detectors (LiF: Mg, Ti, TLD-100) placed at chest and abdomen levels above and below the lead apron, and at both right and left arms, knees and feet. A special glove was developed with casings for the insertion of 11 extremity detectors (LiF:Mg, Cu, P, TLD-100H) for the identification of the most highly exposed fingers. The H(p)(10) dose values received above the lead apron (ranged 0.20-0.02 mSv) depend mainly on the duration of the examination and on the placement of physician relative to the beam, while values below the apron are relatively low. The left arm seems to receive a higher dose value. H(p)(0.07) values to the hand (ranged 36.30-0.06 mSv) show that the index, middle and ring fingers are the most highly exposed. In this study, the wrist dose was negligible compared with the finger dose. These results are preliminary and further studies are needed to better characterise the dose assessment in CT fluoroscopy.

  15. Radiation dose assessment in a 320-detector-row CT scanner used in cardiac imaging

    SciTech Connect

    Goma, Carles; Ruiz, Agustin; Jornet, Nuria; Latorre, Artur; Pallerol, Rosa M.; Carrasco, Pablo; Eudaldo, Teresa; Ribas, Montserrat

    2011-03-15

    Purpose: In the present era of cone-beam CT scanners, the use of the standardized CTDI{sub 100} as a surrogate of the idealized CTDI is strongly discouraged and, consequently, so should be the use of the dose-length product (DLP) as an estimate of the total energy imparted to the patient. However, the DLP is still widely used as a reference quantity to normalize the effective dose for a given scan protocol mainly because the CTDI{sub 100} is an easy-to-measure quantity. The aim of this article is therefore to describe a method for radiation dose assessment in large cone-beam single axial scans, which leads to a straightforward estimation of the total energy imparted to the patient. The authors developed a method accessible to all medical physicists and easy to implement in clinical practice in an attempt to update the bridge between CT dosimetry and the estimation of the effective dose. Methods: The authors used commercially available material and a simple mathematical model. The method described herein is based on the dosimetry paradigm introduced by the AAPM Task Group 111. It consists of measuring the dose profiles at the center and the periphery of a long body phantom with a commercial solid-state detector. A weighted dose profile is then calculated from these measurements. To calculate the CT dosimetric quantities analytically, a Gaussian function was fitted to the dose profile data. Furthermore, the Gaussian model has the power to condense the z-axis information of the dose profile in two parameters: The single-scan central dose, f(0), and the width of the profile, {sigma}. To check the energy dependence of the solid-state detector, the authors compared the dose profiles to measurements made with a small volume ion chamber. To validate the overall method, the authors compared the CTDI{sub 100} calculated analytically to the measurement made with a 100 mm pencil ion chamber. Results: For the central and weighted dose profiles, the authors found a good

  16. Dose verification of intensity-modulated arc therapy using an ERGO++ treatment planning system and Elekta internal multileaf collimators for prostate cancer treatment.

    PubMed

    Yoda, K; Nakagawa, K; Shiraishi, K; Okano, Y; Ohtomo, K; Pellegrini, R G

    2009-04-01

    Dose verification of intensity-modulated arc therapy using an ERGO++ treatment planning system and Elekta internal multileaf collimators is described. Prostate intensity-modulated arc therapy was planned using the arc modulation optimization algorithm inverse planning module of ERGO++. After transferring the plan to Elekta Synergy's controller (Elekta Ltd, Crawley, UK), the isocentre dose was measured and compared with a calculated dose using a pinpoint chamber and a water phantom in a cylindrical acrylic enclosure. Subsequently, an EDR2 film was placed inside a multilayer plastic phantom, and total dose distributions were measured in three axial planes as well as in the coronal and sagittal planes to compare the actual dose with the calculated dose. The dose discrepancy at the isocentre was 1.7%. The calculated gamma indices were less than 1 over 90% of the three axial planes, as well as in the coronal and sagittal planes, having a dose greater than 50% of the maximum target dose.

  17. Assessment of knowledge, attitude, and practices on fixed dose combinations among postgraduate dental students

    PubMed Central

    Vinnakota, Narayana R.; Krishna, V.; Viswanath, V.; Ahmed, Zaheer; Shaik, Kamal S.; Boppana, Naveen K.

    2016-01-01

    Aim: To assess the knowledge, attitude, and practices of fixed dose combination drugs among postgraduate dental students. Materials and Methods: A cross-sectional study was carried out among postgraduate dental students of dental colleges in coastal Andhra Pradesh. Three colleges were randomly selected and students of all the three years were included. Data was collected from the specialities of oral medicine and radiology, oral surgery, endodontics, pedodontics, periodontics, and public health dentistry. The total sample was 90 postgraduate students; informed consent was obtained from the participants, and a pretested questionnaire was distributed to them. Data was analyzed using the Statistical Package for the Social Sciences version 20 software. Results: Out of 90 postgraduates, 33 were males and 57 were females. Thirty-five percent were aware of the essential medical list (EML), among them 11% were from oral medicine and radiology and 6.7% were from pedodontics. However, most of them were unaware of the number of fixed dose combination drugs present in the World Health Organization EML. None of them were able to name at least a single banned fixed dose combination drug. Most of them were unaware of the advantages and disadvantages of using fixed dose combination drugs. Amoxicillin with clavulanic acid was the most common drug prescribed by students (73.3%) followed by ofloxacin with ornidazole (54.4%), ibuprofen with paracetamol (53.3%), and sulfamethoxazole with trimethoprim (6%). Most of them were unaware of the rationality in using fixed dose combination drugs. Common sources of information were medical representatives 43 (47.8%), internet 39 (43.3%), and 12 (13.3%) reported using WHO EML. Conclusion: There is an urgent need to improve knowledge on the rationality for using fixed dose combination, EML, and banned fixed dose combination in India to the promote rational use of fixed dose combination. PMID:28217544

  18. Assessment of knowledge, attitude, and practices on fixed dose combinations among postgraduate dental students.

    PubMed

    Vinnakota, Narayana R; Krishna, V; Viswanath, V; Ahmed, Zaheer; Shaik, Kamal S; Boppana, Naveen K

    2016-12-01

    To assess the knowledge, attitude, and practices of fixed dose combination drugs among postgraduate dental students. A cross-sectional study was carried out among postgraduate dental students of dental colleges in coastal Andhra Pradesh. Three colleges were randomly selected and students of all the three years were included. Data was collected from the specialities of oral medicine and radiology, oral surgery, endodontics, pedodontics, periodontics, and public health dentistry. The total sample was 90 postgraduate students; informed consent was obtained from the participants, and a pretested questionnaire was distributed to them. Data was analyzed using the Statistical Package for the Social Sciences version 20 software. Out of 90 postgraduates, 33 were males and 57 were females. Thirty-five percent were aware of the essential medical list (EML), among them 11% were from oral medicine and radiology and 6.7% were from pedodontics. However, most of them were unaware of the number of fixed dose combination drugs present in the World Health Organization EML. None of them were able to name at least a single banned fixed dose combination drug. Most of them were unaware of the advantages and disadvantages of using fixed dose combination drugs. Amoxicillin with clavulanic acid was the most common drug prescribed by students (73.3%) followed by ofloxacin with ornidazole (54.4%), ibuprofen with paracetamol (53.3%), and sulfamethoxazole with trimethoprim (6%). Most of them were unaware of the rationality in using fixed dose combination drugs. Common sources of information were medical representatives 43 (47.8%), internet 39 (43.3%), and 12 (13.3%) reported using WHO EML. There is an urgent need to improve knowledge on the rationality for using fixed dose combination, EML, and banned fixed dose combination in India to the promote rational use of fixed dose combination.

  19. Cardiovascular disorders associated with naloxone monotherapy and in fixed-dose combination with opioids: Data from international safety surveillance.

    PubMed

    Sandhu, Amneet; Kao, David; Mehler, Philip S; Haigney, Mark C P; Krantz, Mori J

    2016-06-01

    The widespread use of opioids has resulted in sharp rise of associated complications, particularly opioid-induced constipation (OIC). Opioid receptor antagonists have been proposed to treat OIC, but could precipitate rapid opioid withdrawal. As cardiovascular safety data are lacking, we assessed disproportionate reporting of adverse cardiac events associated with naloxone across large, international pharmacovigilance systems. Post-marketing data from the World Health Organization (WHO) and FDA Adverse Events Reporting System (FAERS) were evaluated for naloxone and the synthetic opioids oxycodone and tilidine. The proportional reporting ratio (PRR), a measure of reporting frequency analogous to an odds ratio, was assessed. The primary outcome was reporting frequency of the MedDRA System Organ Class (SOC) 'Cardiac Disorders' for naloxone alone and in fixed-dose combination with opioids. Opioid mono-preparations served as quasi-experimental controls. A PRR greater than 2.0 was considered significant. In total, 14,827,374 million adverse drug event reports were reviewed. In WHO, there were 1757 reports of SOC cardiac disorders among 10,866 total reports for oxycodone (PRR 2.38 [95% CI 2.28-2.49, χ(2)=1504]). For oxycodone-naloxone, there were 43/453 reports of SOC cardiac disorders (PRR 1.45 [95% CI 1.09-1.92, χ(2)=6.4]). For the synthetic opioid tilidine there were 13/179 reports (PRR 1.13 [95% CI 0.67-1.91, χ(2)=0.2]) and for tilidine-naloxone, 30/505 reports (PRR 0.92 [95% CI 0.65-1.31, χ(2)=0.2]). In FAERS, the PRR for SOC cardiac disorders was 0.95 [95% CI 0.89-1.01, χ(2)=2.1] for naloxone (all administration routes) and 1.16 [95% CI 0.93-1.45, χ(2)=1.3] for naloxone (oral only). In comparison, the PRR was 1.66 [95% CI 1.63-1.69, χ(2)=4278] for oxycodone and 1.52 [CI 1.28-1.80, χ(2)=1500] for oxycodone-naloxone. Available pharmacovigilance data do not suggest disproportionate reporting of adverse cardiovascular events for opioid antagonists used to treat

  20. Modeling of occupational exposure to accidentally released manufactured nanomaterials in a production facility and calculation of internal doses by inhalation

    PubMed Central

    Vaquero-Moralejo, Celina; Jaén, María; Lopez De Ipiña Peña, Jesús; Neofytou, Panagiotis

    2016-01-01

    Background Occupational exposure to manufactured nanomaterials (MNMs) and its potential health impacts are of scientific and practical interest, as previous epidemiological studies associate exposure to nanoparticles with health effects, including increased morbidity of the respiratory and the circulatory system. Objectives To estimate the occupational exposure and effective internal doses in a real production facility of TiO2 MNMs during hypothetical scenarios of accidental release. Methods Commercial software for geometry and mesh generation, as well as fluid flow and particle dispersion calculation, were used to estimate occupational exposure to MNMs. The results were introduced to in-house software to calculate internal doses in the human respiratory tract by inhalation. Results Depending on the accidental scenario, different areas of the production facility were affected by the released MNMs, with a higher dose exposure among individuals closer to the particles source. Conclusions Granted that the study of the accidental release of particles can only be performed by chance, this numerical approach provides valuable information regarding occupational exposure and contributes to better protection of personnel. The methodology can be used to identify occupational settings where the exposure to MNMs would be high during accidents, providing insight to health and safety officials. PMID:27670588

  1. 10 CFR 20.1202 - Compliance with requirements for summation of external and internal doses.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... section. (Note: The dose equivalents for the lens of the eye, the skin, and the extremities are not... it in demonstrating compliance with the limits. (d) Intake through wounds or absorption through skin. The licensee shall evaluate and, to the extent practical, account for intakes through wounds or...

  2. Linking Different Exposure Patterns to Internal Lung Dose for Heterogeneous Ambient Aerosols

    EPA Science Inventory

    Particulate matter (PM) in the ambient air is a complex mixture of particles with different sizes and chemical compositions. Because potential health effects are known to be different for different size particles, specific dose of size-fractionated PM under realistic exposure con...

  3. Linking Different Exposure Patterns to Internal Lung Dose for Heterogeneous Ambient Aerosols

    EPA Science Inventory

    Particulate matter (PM) in the ambient air is a complex mixture of particles with different sizes and chemical compositions. Because potential health effects are known to be different for different size particles, specific dose of size-fractionated PM under realistic exposure con...

  4. An international review of autism knowledge assessment measures.

    PubMed

    Harrison, Ashley J; Slane, Mylissa M; Hoang, Linh; Campbell, Jonathan M

    2017-04-01

    Autism spectrum disorder-specific knowledge deficits contribute to current disparities in the timing and quality of autism spectrum disorder services throughout the United States and globally. This study conducted a systematic review of Western and International literature to examine measures used to assess autism spectrum disorder knowledge. This review identified 44 unique autism spectrum disorder knowledge measures across 67 studies conducted in 21 countries. Measures used in each study were evaluated in terms of psychometric strength. Of the 67 studies reviewed, only 7% were rated as using a measure with strong psychometric support compared to 45% that were rated as using a measure with no reported psychometric support. Additionally, we examined content overlap and subdomains of autism spectrum disorder knowledge assessed (e.g. etiology, symptoms) and cross-cultural adaptation procedures utilized in the field. Based on these findings, the need for a cross-culturally valid and psychometrically sound measure of autism spectrum disorder knowledge is discussed and recommendations for improving current assessment methods are presented, including suggestions for measure subdomains.

  5. Comparison of Nine Statistical Model Based Warfarin Pharmacogenetic Dosing Algorithms Using the Racially Diverse International Warfarin Pharmacogenetic Consortium Cohort Database.

    PubMed

    Liu, Rong; Li, Xi; Zhang, Wei; Zhou, Hong-Hao

    2015-01-01

    Multiple linear regression (MLR) and machine learning techniques in pharmacogenetic algorithm-based warfarin dosing have been reported. However, performances of these algorithms in racially diverse group have never been objectively evaluated and compared. In this literature-based study, we compared the performances of eight machine learning techniques with those of MLR in a large, racially-diverse cohort. MLR, artificial neural network (ANN), regression tree (RT), multivariate adaptive regression splines (MARS), boosted regression tree (BRT), support vector regression (SVR), random forest regression (RFR), lasso regression (LAR) and Bayesian additive regression trees (BART) were applied in warfarin dose algorithms in a cohort from the International Warfarin Pharmacogenetics Consortium database. Covariates obtained by stepwise regression from 80% of randomly selected patients were used to develop algorithms. To compare the performances of these algorithms, the mean percentage of patients whose predicted dose fell within 20% of the actual dose (mean percentage within 20%) and the mean absolute error (MAE) were calculated in the remaining 20% of patients. The performances of these techniques in different races, as well as the dose ranges of therapeutic warfarin were compared. Robust results were obtained after 100 rounds of resampling. BART, MARS and SVR were statistically indistinguishable and significantly out performed all the other approaches in the whole cohort (MAE: 8.84-8.96 mg/week, mean percentage within 20%: 45.88%-46.35%). In the White population, MARS and BART showed higher mean percentage within 20% and lower mean MAE than those of MLR (all p values < 0.05). In the Asian population, SVR, BART, MARS and LAR performed the same as MLR. MLR and LAR optimally performed among the Black population. When patients were grouped in terms of warfarin dose range, all machine learning techniques except ANN and LAR showed significantly higher mean percentage within 20

  6. Assessment of eye lens doses for workers during interventional radiology procedures.

    PubMed

    Urboniene, A; Sadzeviciene, E; Ziliukas, J

    2015-07-01

    The assessment of eye lens doses for workers during interventional radiology (IR) procedures was performed using a new eye lens dosemeter. In parallel, the results of routine individual monitoring were analysed and compared with the results obtained from measurements with a new eye lens dosemeter. The eye lens doses were assessed using Hp(3) measured at the level of the eyes and were compared with Hp(10) measured with the whole-body dosemeter above the lead collar. The information about use of protective measures, the number of performed interventional procedures per month and their fluoroscopy time was also collected. The assessment of doses to the lens of the eye was done for 50 IR workers at 9 Lithuanian hospitals for the period of 2012-2013. If the use of lead glasses is not taken into account, the estimated maximum annual dose equivalent to the lens of the eye was 82 mSv. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Beyond dose assessment: using risk with full disclosure of uncertainty in public and scientific communication.

    PubMed

    Hoffman, F Owen; Kocher, David C; Apostoaei, A Iulian

    2011-11-01

    Evaluations of radiation exposures of workers and the public traditionally focus on assessments of radiation dose, especially annual dose, without explicitly evaluating the health risk associated with those exposures, principally the risk of radiation-induced cancer. When dose is the endpoint of an assessment, opportunities to communicate the significance of exposures are limited to comparisons with dose criteria in regulations, doses due to natural background or medical x-rays, and doses above which a statistically significant increase of disease has been observed in epidemiologic studies. Risk assessment generally addresses the chance (probability) that specific diseases might be induced by past, present, or future exposure. The risk of cancer per unit dose will vary depending on gender, age, exposure type (acute or chronic), and radiation type. It is not uncommon to find that two individuals with the same effective dose will have substantially different risks. Risk assessment has shown, for example, that: (a) medical exposures to computed tomography scans have become a leading source of future risk to the general population, and that the risk would be increased above recently published estimates if the incidence of skin cancer and the increased risk from exposure to x-rays compared with high-energy photons were taken into account; (b) indoor radon is a significant contributor to the baseline risk of lung cancer, particularly among people who have never smoked; and (c) members of the public who were exposed in childhood to I in fallout from atmospheric nuclear weapons tests and were diagnosed with thyroid cancer later in life would frequently meet criteria established for federal compensation of cancers experienced by energy workers and military participants at atmospheric weapons tests. Risk estimation also enables comparisons of impacts of exposures to radiation and chemical carcinogens and other hazards to life and health. Communication of risk with

  8. Analysis of finite dose dermal absorption data: Implications for dermal exposure assessment

    PubMed Central

    Frasch, H Frederick; Dotson, G Scott; Bunge, Annette L; Chen, Chen-Peng; Cherrie, John W; Kasting, Gerald B; Kissel, John C; Sahmel, Jennifer; Semple, Sean; Wilkinson, Simon

    2014-01-01

    A common dermal exposure assessment strategy estimates the systemic uptake of chemical in contact with skin using the fixed fractional absorption approach: the dermal absorbed dose is estimated as the product of exposure and the fraction of applied chemical that is absorbed, assumed constant for a given chemical. Despite the prominence of this approach there is little guidance regarding the evaluation of experiments from which fractional absorption data are measured. An analysis of these experiments is presented herein, and limitations to the fixed fractional absorption approach are discussed. The analysis provides a set of simple algebraic expressions that may be used in the evaluation of finite dose dermal absorption experiments, affording a more data-driven approach to dermal exposure assessment. Case studies are presented that demonstrate the application of these tools to the assessment of dermal absorption data. PMID:23715085

  9. The use of mode of action information in risk assessment: quantitative key events/dose-response framework for modeling the dose-response for key events.

    PubMed

    Simon, Ted W; Simons, S Stoney; Preston, R Julian; Boobis, Alan R; Cohen, Samuel M; Doerrer, Nancy G; Fenner-Crisp, Penelope A; McMullin, Tami S; McQueen, Charlene A; Rowlands, J Craig

    2014-08-01

    The HESI RISK21 project formed the Dose-Response/Mode-of-Action Subteam to develop strategies for using all available data (in vitro, in vivo, and in silico) to advance the next-generation of chemical risk assessments. A goal of the Subteam is to enhance the existing Mode of Action/Human Relevance Framework and Key Events/Dose Response Framework (KEDRF) to make the best use of quantitative dose-response and timing information for Key Events (KEs). The resulting Quantitative Key Events/Dose-Response Framework (Q-KEDRF) provides a structured quantitative approach for systematic examination of the dose-response and timing of KEs resulting from a dose of a bioactive agent that causes a potential adverse outcome. Two concepts are described as aids to increasing the understanding of mode of action-Associative Events and Modulating Factors. These concepts are illustrated in two case studies; 1) cholinesterase inhibition by the pesticide chlorpyrifos, which illustrates the necessity of considering quantitative dose-response information when assessing the effect of a Modulating Factor, that is, enzyme polymorphisms in humans, and 2) estrogen-induced uterotrophic responses in rodents, which demonstrate how quantitative dose-response modeling for KE, the understanding of temporal relationships between KEs and a counterfactual examination of hypothesized KEs can determine whether they are Associative Events or true KEs.

  10. New model for assessing dose, dose rate, and temperature sensitivity of radiation-induced absorption in glasses

    SciTech Connect

    Gilard, Olivier; Quadri, Gianandrea; Caussanel, Matthieu; Duval, Herve; Reynaud, Francois

    2010-11-15

    A new theoretical approach is proposed to explain the dose, dose rate and temperature sensitivity of the radiation-induced absorption (RIA) in glasses. In this paper, a {beta}{sup th}-order dispersive kinetic model is used to simulate the growth of the density of color centers in irradiated glasses. This model yields an explanation for the power-law dependence on dose and dose rate usually observed for the RIA in optical fibers. It also leads to an Arrhenius-like relationship between the RIA and the glass temperature during irradiation. With a very limited number of adjustable parameters, the model succeeds in explaining, with a good agreement, the RIA growth of two different optical fiber references over wide ranges of dose, dose rate and temperature.

  11. Human Health Risk Assessment: A case study application of principles in dose response assessment

    EPA Science Inventory

    This case study application workshop will build on fundamental concepts and techniques in risk assessment presented and archived at previous TRAC meeting workshops. Practical examples from publicly available, peer reviewed risk assessments will be used as teaching aids. Course ...

  12. Applications of the International Space Station Probabilistic Risk Assessment Model

    NASA Technical Reports Server (NTRS)

    Grant, Warren; Lutomski, Michael G.

    2011-01-01

    Recently the International Space Station (ISS) has incorporated more Probabilistic Risk Assessments (PRAs) in the decision making process for significant issues. Future PRAs will have major impact to ISS and future spacecraft development and operations. These PRAs will have their foundation in the current complete ISS PRA model and the current PRA trade studies that are being analyzed as requested by ISS Program stakeholders. ISS PRAs have recently helped in the decision making process for determining reliability requirements for future NASA spacecraft and commercial spacecraft, making crew rescue decisions, as well as making operational requirements for ISS orbital orientation, planning Extravehicular activities (EVAs) and robotic operations. This paper will describe some applications of the ISS PRA model and how they impacted the final decision. This paper will discuss future analysis topics such as life extension, requirements of new commercial vehicles visiting ISS.

  13. Measurements of the neutron dose and energy spectrum on the International Space Station during expeditions ISS-16 to ISS-21.

    PubMed

    Smith, M B; Akatov, Yu; Andrews, H R; Arkhangelsky, V; Chernykh, I V; Ing, H; Khoshooniy, N; Lewis, B J; Machrafi, R; Nikolaev, I; Romanenko, R Y; Shurshakov, V; Thirsk, R B; Tomi, L

    2013-01-01

    As part of the international Matroshka-R and Radi-N experiments, bubble detectors have been used on board the ISS in order to characterise the neutron dose and the energy spectrum of neutrons. Experiments using bubble dosemeters inside a tissue-equivalent phantom were performed during the ISS-16, ISS-18 and ISS-19 expeditions. During the ISS-20 and ISS-21 missions, the bubble dosemeters were supplemented by a bubble-detector spectrometer, a set of six detectors that was used to determine the neutron energy spectrum at various locations inside the ISS. The temperature-compensated spectrometer set used is the first to be developed specifically for space applications and its development is described in this paper. Results of the dose measurements indicate that the dose received at two different depths inside the phantom is not significantly different, suggesting that bubble detectors worn by a person provide an accurate reading of the dose received inside the body. The energy spectra measured using the spectrometer are in good agreement with previous measurements and do not show a strong dependence on the precise location inside the station. To aid the understanding of the bubble-detector response to charged particles in the space environment, calculations have been performed using a Monte-Carlo code, together with data collected on the ISS. These calculations indicate that charged particles contribute <2% to the bubble count on the ISS, and can therefore be considered as negligible for bubble-detector measurements in space.

  14. Internal radiation exposure dose in Iwaki city, Fukushima prefecture after the accident at Fukushima Dai-ichi Nuclear Power Plant.

    PubMed

    Orita, Makiko; Hayashida, Naomi; Nukui, Hiroshi; Fukuda, Naoko; Kudo, Takashi; Matsuda, Naoki; Fukushima, Yoshiko; Takamura, Noboru

    2014-01-01

    As a result of the accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) on 11 March 2011, a huge amount of radionuclides, including radiocesium, was released and spread over a wide area of eastern Japan. Although three years have passed since the accident, residents around the FNPP are anxious about internal radiation exposure due to radiocesium. In this study, we screened internal radiation exposure doses in Iwaki city of Fukushima prefecture, using a whole-body counter. The first screening was conducted from October 2012 to February 2013, and the second screening was conducted from May to November 2013. Study participants were employees of ALPINE and their families who underwent examination. A total of 2,839 participants (1,366 men and 1,473 women, 1-86 years old) underwent the first screening, and 2,092 (1,022 men and 1,070 women, 1-86 years old) underwent the second screening. The results showed that 99% of subjects registered below 300 Bq per body in the first screening, and all subjects registered below 300 Bq per body in the second screening. The committed effective dose ranged from 0.01-0.06 mSv in the first screening and 0.01-0.02 mSv in the second screening. Long-term follow-up studies are needed to avoid unnecessary chronic internal exposure and to reduce anxiety among the residents by communicating radiation health risks.

  15. Internal Radiation Exposure Dose in Iwaki City, Fukushima Prefecture after the Accident at Fukushima Dai-ichi Nuclear Power Plant

    PubMed Central

    Orita, Makiko; Hayashida, Naomi; Nukui, Hiroshi; Fukuda, Naoko; Kudo, Takashi; Matsuda, Naoki; Fukushima, Yoshiko; Takamura, Noboru

    2014-01-01

    As a result of the accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) on 11 March 2011, a huge amount of radionuclides, including radiocesium, was released and spread over a wide area of eastern Japan. Although three years have passed since the accident, residents around the FNPP are anxious about internal radiation exposure due to radiocesium. In this study, we screened internal radiation exposure doses in Iwaki city of Fukushima prefecture, using a whole-body counter. The first screening was conducted from October 2012 to February 2013, and the second screening was conducted from May to November 2013. Study participants were employees of ALPINE and their families who underwent examination. A total of 2,839 participants (1,366 men and 1,473 women, 1–86 years old) underwent the first screening, and 2,092 (1,022 men and 1,070 women, 1–86 years old) underwent the second screening. The results showed that 99% of subjects registered below 300 Bq per body in the first screening, and all subjects registered below 300 Bq per body in the second screening. The committed effective dose ranged from 0.01–0.06 mSv in the first screening and 0.01–0.02 mSv in the second screening. Long-term follow-up studies are needed to avoid unnecessary chronic internal exposure and to reduce anxiety among the residents by communicating radiation health risks. PMID:25478794

  16. Assessment of Annual Effective Dose for Natural Radioactivity of Gamma Emitters in Biscuit Samples in Iraq.

    PubMed

    Abojassim, Ali Abid; Al-Alasadi, Lubna A; Shitake, Ahmed R; Al-Tememie, Faeq A; Husain, Afnan A

    2015-09-01

    Biscuits are an important type of food, widely consumed by babies in Iraq and other countries. This work uses gamma spectroscopy to measure the natural radioactivity due to long-lived gamma emitters in children's biscuits; it also estimates radiation hazard indices, that is, the radium equivalent activity, the representative of gamma level index, the internal hazard index, and the annual effective dose in children. Ten samples were collected from the Iraqi market from different countries of origin. The average specific activities for (226)Ra, (232)Th, and (40)K were 9.390, 3.1213, and 214.969 Bq/kg, respectively, but the average of the radium equivalent activity and the internal hazard index were 33.101 Bq/kg and 0.107, respectively. The total average annual effective dose from consumption by adults, children, and infants is estimated to be 0.655, 1.009, and 0.875 mSv, respectively. The values found for specific activity, radiation hazard indices, and annual effective dose in all samples in this study were lower than worldwide median values for all groups; therefore, these values are found to be safe.

  17. Historical development and evolution of EPRI's post-closure dose assessment of potential releases to the biosphere from the proposed HLW repository at Yucca Mountain.

    PubMed

    Smith, Graham; Kozak, Matthew W

    2011-12-01

    This paper describes the development and evolution of the Electric Power