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Application of Snyder's method for estimation of body burden and intake to blood to uranium bioassay data

Description: The problem of estimating internal exposure from the intake of uranium is discussed. Excreta samples are routinely taken from workers at regular intervals during normal operations and/or after an accidental release of radioactive substances to the immediate environment of the worker. Data on the activity excreted per day is analyzed to estimate the intake of uranium into the blood and the body. (ACR)
Date: January 1, 1983
Creator: Bernard, S.R.
Partner: UNT Libraries Government Documents Department

Some medical aspects of radionuclide intakes

Description: In the field of medicine, particularly industrial medicine, the radiation aspect of the practice probably takes about 1/10 of 1% of our time. All the health physicist's tools of principles of internal dosimetry, lung models, mathematics, chemistry, etc. have little meaning until applied to an individual who has had an intake. This article discusses some of the medical aspects of internal dosimetry.
Date: January 1, 1983
Creator: Poda, G A
Partner: UNT Libraries Government Documents Department

Psychological aspects of personnel contamination

Description: This paper discusses some of the major emotional considerations involved in the treatment of people who have been contaminated with potentially hazardous materials. Although the principal focus is the treatment of people trained to work with these materials, an attempt is also made to extend these methods to people having little or no knowledge of such matters. Accidents always result in emotional trauma. When the accident involves radioactive or other potentially toxic, carcinogenic, or mutagenic materials, there is a possibility of enhanced emotional stress due to the mystique surrounding these substances. Several psychological principles that have emerged from the treatment of radioactively-contaminated workers are: (1) provide pre-accident training for all radiation workers; (2) avoid secrets; (3) as rapidly as possible following a contamination accident, bring the worker into contact with others; (4) recognize the emotions of the family and the family's fears and trauma; and (5) do not desert the worker after decontamination has been completed. 1 ref.
Date: April 1, 1985
Creator: Wilson, R.L.
Partner: UNT Libraries Government Documents Department

Current internal-dosimetry practices at US Department of Energy facilities

Description: The internal dosimetry practice at DOE facilities were characterized. The purpose was to determine the size of the facilities' internal dosimetry programs, the uniformity of the programs among the facilities, and the areas of greatest concern to health physicists in providing and reporting accurate estimates of internal radiation dose and in meeting proposed changes in internal dosimetry. The differences among the internal-dosimetry programs are related to the radioelements in use at each facility and, to some extent, the number of workers at each facility. The differences include different frequencies in the use of quality control samples, different minimum detection levels, different methods of recording radionuclides, different amounts of data recorded in the permanent record, and apparent differences in modeling the metabolism of radionuclides within the body. Recommendations for improving internal-dosimetry practices include studying the relationship between air-monitoring/survey readings and bioassay data, establishing uniform methods for recording bioassay results, developing more sensitive direct-bioassay procedures, establishing a mechanism for sharing information on internal-dosimetry procedures among DOE facilities, and developing mathematical models and interactive computer codes that can help quantify the uptake of radioactive materials and predict their distribution in the body. 19 refs., 8 tabs.
Date: April 1, 1985
Creator: Traub, R.J.; Murphy, B.L.; Selby, J.M. & Vallario, E.J.
Partner: UNT Libraries Government Documents Department

Contributions of occupational epidemiologic studies to radiation protection

Description: Early evidence of health effects of occupational radiation exposure contributed importantly to the establishment of exposure standards, especially for internal emitters. Standards derived in this manner for radium body burdens and for air concentrations of radon and its daughters were especially influential. The body burden limits for plutonium and other bone-seeking radionuclides were based upon the radium standard. The exposure controls instituted as a consequence of those early limits have reduced the exposure of worker populations to the extent that the current, more sophisticated epidemiologic studies will probably not influence the revision of existing standards. The justification for conducting such studies is discussed.
Date: January 1, 1982
Creator: Marks, S.
Partner: UNT Libraries Government Documents Department

Historical review of personnel dosimetry development and its use in radiation protection programs at Hanford 1944 to the 1980s

Description: This document is an account of the personnel dosimetry programs as they were developed and practiced at Hanford from their inception in 1943 to 1944 to the 1980s. This history is divided into sections covering the general categories of external and internal measurement methods, in vivo counting, radiation exposure recordkeeping, and calibration of personnel dosimeters. The reasons and circumstances surrounding the inception of these programs at Hanford are discussed. Information about these programs was obtained from documents, letters, and memos that are available in our historical records; the personnel files of many people who participated in these programs; and from the recollections of many long-time, current, and past Hanford employees. For the most part, the history of these programs is presented chronologically to relate their development and use in routine Hanford operations. 131 refs., 38 figs., 23 tabs.
Date: February 1, 1987
Creator: Wilson, R.H.
Partner: UNT Libraries Government Documents Department

Recommended procedures for performance testing of radiobioassay laboratories: Volume 2, In vitro samples

Description: Draft American National Standards Institute (ANSI) Standard N13.30 (Performance Criteria for Radiobioassay) was developed for the US Department of Energy and the US Nuclear Regulatory Commission to help ensure that bioassay laboratories provide accurate and consistent results. The draft standard specifies the criteria for defining the procedures necessary to establish a bioassay performance-testing laboratory and program. The bioassay testing laboratory will conduct tests to evaluate the performance of service laboratories. Pacific Northwest Laboratory helped develop testing procedures as part of an effort to evaluate the performance criteria by testing the existing measurement capabilities of various bioassay laboratories. This report recommends guidelines for the preparation, handling, storage, distribution, shipping, and documentation of in vitro test samples (artificial urine and fecal matter) for indirect bioassay. The data base and recommended records system for documenting radiobioassay performance at the service laboratories are also presented. 8 refs., 3 tabs.
Date: November 1, 1988
Creator: Fenrick, H.W. & MacLellan, J.A.
Partner: UNT Libraries Government Documents Department

Recommended procedures for performance testing of radiobioassay laboratories: Volume 1, Quality assurance. [Contains Glossary]

Description: Draft American National Standards Institute (ANSI) Standard N13.30 (Performance Criteria for Radiobioassay) was developed in response to a concern expressed by the US Department of Energy and US Nuclear Regulatory Commission to help ensure that bioassay laboratories provide accurate and consistent results. The draft standard specifies the criteria for defining the procedures necessary to establish a bioassay performance-testing laboratory and program. The testing laboratory will conduct tests to evaluate the performance of service laboratories. Pacific Northwest Laboratory helped define responsibilities and develop procedures as part of an effort to evaluate the draft ANSI N13.30 performance criteria for quality assurance at bioassay laboratories. This report recommends elements of quality assurance and quality control responsibilities for the bioassay performance-testing laboratory program, including the qualification and performance of personnel and the calibration, certification, and performance of equipment. The data base and recommended records system for documenting radiobioassay performance at the service laboratories are also presented. 15 refs.
Date: November 1, 1988
Creator: Fenrick, H.W. & MacLellan, J.A.
Partner: UNT Libraries Government Documents Department

What is the probability that radiation caused a particular cancer

Description: Courts, lawyers, health physicists, physicians, and others are searching for a credible answer to the question posed in the title of this paper. The cases in which the question arises frequently stem from an individual that has cancer and they, or their next-of-kin, are convinced that a past radiation exposure - usually small - is responsible for causing it. An arithmetic expression of this problem is simple: the probability of causation by the radiation dose in question is equal to the risk of cancer from the radiation dose divided by the risk of cancer from all causes. The application of risk factors to this equation is not so simple. It must involve careful evaluation of the reliability of and variations in risk coefficients for development of cancer due to radiation exposure, other carcinogenic agents, and natural causes for the particular individual. Examination of our knowledge of these various factors indicates that a large range in the answers can result due to the variability and imprecision of the data. Nevertheless, the attempts to calculate and the probability that radiation caused the cancer is extremely useful to provide a gross perspective on the probability of causation. It will likely rule in or out a significant number of cases despite the limitations in our understandings of the etiology of cancer and the risks from various factors. For the remaining cases, a thoughtful and educated judgment based on selected data and circumstances of the case will also be needed before the expert can develop and support his opinion.
Date: January 1, 1983
Creator: Voelz, G.L.
Partner: UNT Libraries Government Documents Department

Distribution of dose within the body from a photon emitter present in an organ

Description: A dosimetric system was developed which provides estimates of mean radiation dose to organs from photon sources distributed uniformly in one or more organs. Although the sources of photons are assumed to be distributed uniformly, it is not true that dose from these photons is uniformly distributed. In particular, when a source of photons is located in a particular organ, nearby tissues will be irradiated at doses which decrease markedly with distance from the source. The mean dose may give a poor approximation to the actual dose if the tissues over which dose is averaged are extensive, for example, the remainder of the body. A set of enveloping organs was devised for liver, lungs, etc., which give mean dose at distances from zero to one centimeter from the source organ, from one to two centimeters, etc. These can be used to yield estimates of the extent of inhomogeneity of the dose distribution from a source of photons located in the source organ.
Date: January 1, 1977
Creator: Snyder, W. S.; Ford, M. R. & Warner, G. G.
Partner: UNT Libraries Government Documents Department

Risk evaluation - conventional and low level effects of radiation

Description: Any discussion of the risk of exposure to potentially-hazardous agents in the environment inevitably involves the question of whether the dose effect curve is of the threshold or linear, non-threshold type. A principal objective of this presentation is to show that the function is actually two separate relationships, each representing distinctly different functions with differing variables on the axes, and each characteristic of quite different functions with differing variables on the axes, and each characteristic of quite different disciplines (i.e., the threshold function, of Pharmacology, Toxicology and Medicine (PTM); the linear, non-threshold function, of Public Health including safety and accident statistics (PHS)). It is shown that low-level exposure (LLE) to radiation falls clearly in the PHS category. A function for cell dose vs. the fraction of single cell quantal responses is characterized, which reflects the absolute and relative sensitivities of cells. Acceptance of this function would obviate any requirement for the use in Radiation Protection of the concepts of a standard radiation, Q, dose equivalent and rem. 9 references, 4 figures.
Date: April 1, 1984
Creator: Bond, V.P. & Varma, M.N.
Partner: UNT Libraries Government Documents Department

Radiation protection guidelines for radiation emergencies

Description: The system of dose limitation and present guidance for emergency workers and guidance for intervention on behalf of the public are discussed. There are three elements for the system of dose limitation: justification, optimization and dose limits. The first element is basically a political process in this country. Justification is based on a risk-benefit analysis, and justification of the use of radioactive materials or radiation is generally not within the authority of radiation protection managers. Radiation protection managers typically assess detriments or harm caused by radiation exposure and have very little expertise in assessing the benefits of a particular practice involving nuclear material.
Date: January 1, 1986
Creator: Lessard, E.T. & Meinhold, C.B.
Partner: UNT Libraries Government Documents Department

Committee on Radiation Epidemiological Research Programs

Description: The Committee on DoE Radiation Epidemiological Research Programs was originally established in response to the needs of the Office of Health and Envirorunental Research, Office of Energy Research in the Department of Energy (DoE). Following a reorganization of DoE health related programs in 1990, the committee now advises the Office of Epidemiology and Health Surveillance which is under the Assistant Secretary for Environment, Safety and Health. These administrative changes have not altered the committee concerns but have served to focus the committee's attention on helping DoE plan for an effective system of worker health surveillance as well as an epidemiologic research program.
Date: June 1, 1992
Creator: Mahlum, D. D.
Partner: UNT Libraries Government Documents Department

United States Transuranium and Uranium Registries

Description: The United States Transuranium and Uranium Registries are unique human tissue research programs studying the distribution, dose, and possible biological effects of the actinide elements in man, with the primary goal of assuring the adequacy of radiation protection standards for these radionuclides. The Registries research is based on radiochemical analysis of tissues collected at autopsy from voluntary donors who have documented occupational exposure to the actinides. To date, tissues, or in some cases radioanalytical results only, have been obtained from approximately 300 individuals; another 464 living individuals have volunteered to participate in the Registries research programs and have signed premortem informed consent and autopsy permissions. The Registries originated at the National Plutonium Registry which was started in 1968 as a then Atomic Energy Commission project under the aegis of a prime contractor at the Hanford site. In 1970, the name was changed to the United States Transuranium Registry to reflect a broader involvement with the higher actinides. In 1978, an administratively separate parallel registry, the United States Uranium Registry, was formed to carry out similar studies among uranium fuel cycle workers.
Date: February 28, 1993
Creator: Kathren, R.
Partner: UNT Libraries Government Documents Department

Hanford Dose Overview Program. Comparison of AIRDOS-EPA and Hanford site dose codes

Description: Radiation dose commitments for persons in the Hanford environs calculated using AIRDOS-EPA were compared with those calculated using a suite of Hanford codes: FOOD, PABLM, DACRIN, and KRONIC. Dose commitments to the population and to the maximally exposed individual (MI) based on annual releases of eight radionuclides from the N-Reactor, were calculated by these codes. Dose commitments from each pathway to the total body, lung, thyroid, and lower large intestine (LLI) are given for the population and MI, respectively. 11 refs., 25 tabs.
Date: November 1, 1985
Creator: Aaberg, R.L. & Napier, B.A.
Partner: UNT Libraries Government Documents Department

Regional aerosol deposition in human upper airways

Description: Laboratory experimental studies were carried out to investigate the factors influencing the deposition of aerosols ranging in size from 1 nm to 10 [mu]m in the human nasal, oral, pharyngeal and laryngeal airways. These experimental studies were performed in replicate upper airway physical models and in human volunteer subjects. New replicate models of the oral passage of an infant, the oral passage of an adult at two openings and the combined nasal and oral airways of an adult were constructed during the period, adding to the existing models of adult, child and infant nasal and oral airways models. Deposition studies in the adult oral and adult nasal models were performed under simulated cyclic flow conditions with 1 nm particles to compare with previously measured constant flow studies. Similar studies with inertial particles (1--10 [mu]m diameter) were performed with the adult nasal model; in both instances, results with cyclic flow were similar to constant flow results using a simple average flow rate based on inspiratory volume and time of inspiration. Human subject studies were performed with particle sizes 5--20 nm for nasal inspiration; preliminary analysis shows good agreement with model studies at several representative flow rates. Nasal inspiratory inertial deposition of 1--4 [mu]m diameter particles was measured in several adults as a function of airway dimensions; dimensional changes of the valve area by decongestion did not produce concomitant deposition changes.
Date: November 1, 1992
Creator: Swift, D.L.
Partner: UNT Libraries Government Documents Department

Tolerance concentration of radioactive gases in air

Description: The effects of ionizing radiation on the lung, specifically the bronchial tubes, were discussed relative to the incidence of lung cancer in radium miners. The energy transferred to the epithelium by inhaled radon was calculated, and the steps in the process leading to the initiation of cancer were described. (ACR)
Date: January 1, 1944
Creator: Failla, G.
Partner: UNT Libraries Government Documents Department

Deposition of inhaled charged ultrafine particles in a simple tracheal model

Description: The deposition of ultrafine (d [le] 200 nm) particles on airway surfaces is an important determinant of the radiation dose that results from inhalation of radon progeny. The activity median diameter of particles to which radon daughters attach is small (10--140 nm). In the absence of charge, deposition in the upper airways of the respiratory system occurs by impaction for large particles and diffusion for small particles. Sedimentation is negligible due to the high flow rates in these airways. Experiments conducted in hollow casts and in vivo in humans have all shown an increase in deposition due to the particle charge. In vivo experimental results showed that there exists a threshold value of charge on the particle (q[sub c]) above which the electrostatic charge enhances deposition. These experiments were performed for particles for which deposition by diffusion is small (d [le] 300 nm). Deposition of ultrafine particles in the airways may occur by a combined mechanism of diffusion and electrostatic charge.
Date: January 1, 1992
Creator: Cohen, B.S.; Ayres, L. & Xiong, J.
Partner: UNT Libraries Government Documents Department

A model of the circulating blood for use in radiation dose calculations

Description: Over the last few years there has been a significant increase in the use of radionuclides in leukocyte, platelet, and erythrocyte imaging procedures. Radiopharmaceutical used in these procedures are confined primarily to the blood, have short half-lives, and irradiate the body as they move through the circulatory system. There is a need for a model, to describe the circulatory system in an adult human, which can be used to provide radiation absorbed dose estimates for these procedures. A simplified model has been designed assuming a static circulatory system and including major organs of the body. The model has been incorporated into the MIRD phantom and calculations have been completed for a number of exposure situations and radionuclides of clinical importance. The model will be discussed in detail and results of calculations using this model will be presented.
Date: January 1, 1987
Creator: Hui, T.E. & Poston, J.W. Sr.
Partner: UNT Libraries Government Documents Department

A linear, time-varying simulation of the respiratory tract system

Description: These results show that regional deposition efficiencies of inhaled particles are highly dependent on the level of physical activity in all the spectrum of thermodynamic and aerodynamic aerosol particle sizes; also it was shown that for particles in the aerodynamic size range, the values of regional deposition efficiencies at the inner regions of the lung are highly dependent on age. In addition, the shape of regional deposition efficiency curves as a function of particle size have a similar behavior for all ages; thus, any variation of the airway geometry and respiratory physiological parameters such as tidal volumes and breathing frequencies due to age difference do not cause a change in the fundamental mechanisms of deposition. Thus, for all the cases of physical activity and age dependency, the deposition of ultrafine aerosol particles is highly enhanced by diffusive processes in all regions of the respiratory tract, and for very large aerosol size particles this behavior is repeated again due to impaction and sedimentation mechanisms. Although the results presented at this work, are the result of computer simulations based on different sources of experimental data, the structure of the computer simulation code BIODEP is flexible enough to the acquisition of any kind of new experimental information in terms of biokinetic analysis and regional deposition parameters. In addition, since the design of BIODEP was intended for easy access to the users, then with exception of the subroutine DIVPAG, at this moment, the modular design of BIODEP using FORTRAN 77 allows the implementation of all the subroutines of BIODEP to be used in a interactive mode with any microcomputer.
Date: November 1, 1992
Creator: Hernandez, O.
Partner: UNT Libraries Government Documents Department

Analysis of uncertainties in CRAC2 calculations: the inhalation pathway

Description: CRAC2 is a computer code for estimating the health effects and economic costs that might result from a release of radioactivity from a nuclear reactor to the environment. This paper describes tests of sensitivity of the predicted health effects to uncertainties in parameters associated with inhalation of the released radionuclides. These parameters are the particle size of the carrier aerosol and, for each element in the release, the clearance parameters for the lung model on which the code's dose conversion factors for inhalation are based. CRAC2 uses hourly meteorological data and a straight-line Gaussian plume model to predict the transport of airborne radioactivity; it includes models for plume depletion and population evacuation, and data for the distributions of population and land use. The code can compute results for single weather sequences, or it can perform random sampling of weather sequences from the meteorological data file and compute results for each weather sequence in the sample. For the work described in this paper, we concentrated on three fixed weather sequences that represent a range of conditions. For each fixed weather sequence, we applied random sampling to joint distributions of the inhalation parameters in order to estimate the sensitivity of the predicted health effects. All sampling runs produced coefficients of variation that were less than 50%, but some differences of means between weather sequences were substantial, as were some differences between means and the corresponding CRAC2 results without random sampling. Early injuries showed differences of as much as 1 to 2 orders of magnitude, while the differences in early fatalities were less than a factor of 2. Latent cancer fatalities varied by less than 10%. 19 references, 6 figures, 3 tables.
Date: January 1, 1984
Creator: Killough, G.G. & Dunning, D.E. Jr.
Partner: UNT Libraries Government Documents Department

Human disease from radon exposures: the impact of energy conservation in buildings

Description: The level of radon and its daughters inside conventional buildings is often higher than the ambient background level. Interest in conserving energy is motivating home-owners and builders to reduce the rate of infiltration of fresh air into homes, and hence to increase the concentration of indoor air contaminants, including radon. It is unlikely, but possible, that the present radiation levels from radon daughters account for much of the lung cancer rate in non-smokers. In any event, it is likely that some increased lung cancer risk would result from increased radon exposures; hence, it is desirable not to allow radon concentrations to rise significantly. There are several ways to circumvent the increased risk without compromising energy conservation considerations.
Date: August 8, 1978
Creator: Budnitz, R.J.; Berk, J.V.; Hollowell, C.D.; Nazaroff, W.W.; Nero, A.V. & Rosenfeld, A.H.
Partner: UNT Libraries Government Documents Department