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Akleyev A.V.,Urals Research Center for Radiation Medicine
Radiation Protection Dosimetry | Year: 2012

Presented in the manuscript are the results of an analytic study on the chronic radiation syndrome (CRS) among 940 residents of the Techa riverside villages. The uniqueness of this pathology is associated with the fact that, so far, this clinical entity has mainly been observed among Mayak PA workers and residents of the Techa riverside villages. The analyses of CRS cases identified among a population characterised by significant heterogeneity in terms of age, baseline health status and other radiosensitivity modification factors presents a considerable scientific and practical interest. It has been shown that a long-term total exposure at doses in excess of the threshold organ dose in people causes primarily functional changes (neutropaenia, thrombocytopaenia, vegetative dysfunction and asthenia) which, if the exposure continues, are transformed into organic changes (bone marrow hypoplasia, organic damage to the nervous system). If the dose rate decreases below the threshold, a complete repair of the functional changes is observed, while organic alterations may persist for a long time. © World Health Organization 2012. All rights reserved. Source

Shishkina E.A.,Urals Research Center for Radiation Medicine
Radiation Measurements | Year: 2012

Non-destructive detection of very low concentrations of 90Sr (about 0.4 Bq g -1) inside powdered samples with masses below 200 mg (such as tooth enamel prepared for EPR measurements) is not a trivial task. Most of the conventional measurement techniques require a special chemical treatment or an enrichment process. Thin-layer α-Al 2O 3:C passive luminescence beta detectors have been successfully used for measuring dose rates due to beta decay of 90Sr inside small samples. In this paper, a new refinement is introduced for the assessment of 90Sr concentration in dental tissue using thin-layer α-Al 2O 3:C passive luminescence beta detectors. The performance parameters of passive luminescence beta detection (such as detection and quantification limits) have been evaluated using statistical analysis of the experimental results. The sources of uncertainty have been analyzed and the total uncertainty calculated using Monte Carlo simulations. The results of TL passive beta detection for measurement of 90Sr concentrations are shown to be in good agreement with those obtained using low-level beta counting. © 2011 Elsevier Ltd. All rights reserved. Source

Smirnova O.A.,Federal State Unitary Enterprise | Akleyev A.V.,Urals Research Center for Radiation Medicine | Dimov G.P.,Urals Research Center for Radiation Medicine
Health Physics | Year: 2014

A profound approach to the analysis of clinical data on the dynamics of major hematopoietic lineages (granulocytopoietic, thrombocytopoietic, and erythrocytopoietic systems) in chronically irradiated humans is proposed. It is based on recently developed mathematical models of these systems in humans, which enable one to study and interpret clinical hematological data. The developed approach is applied to the analysis of statistically processed clinical data, which were obtained under hematological examinations of residents of Techa riverside villages. These people were exposed to chronic irradiation with varying dose rate due to the radioactive contamination of the river basin by the Mayak Production Association. In the course of modeling studies, the relationship between the dynamics of aforementioned systems in examined individuals and the variation of chronic exposure dose rate over the considered period of time is revealed. It is found that the models are capable of reproducing common regularities and peculiarities of the dynamics of systems on hand, including the decreased stationary levels of blood cell concentrations during the period of maximum radiation exposure, the recovery processes during the period of decrease of exposure dose rate, and the prevalence of younger bone marrow granulocytopoietic cells over more mature ones during the entire period. The mechanisms of such effects of chronic irradiation on the hematopoietic lineages are revealed on the basis of modeling studies. All this testifies to the efficiency of employment of the developed models in the analysis, investigation, and prediction of effects of chronic irradiation on human hematopoietic system. Copyright © 2014 Health Physics Society. Unauthorized reproduction of this article is prohibited. Source

Shagina N.B.,Urals Research Center for Radiation Medicine | Tolstykh E.I.,Urals Research Center for Radiation Medicine | Degteva M.O.,Urals Research Center for Radiation Medicine | Anspaugh L.R.,University of Utah | Napier B.A.,Pacific Northwest National Laboratory
Journal of Radiological Protection | Year: 2015

A biokinetic model for strontium in humans is necessary for quantification of internal doses due to strontium radioisotopes. The ICRP-recommended biokinetic model for strontium has limitations for use in a population study, because it is not gender specific and does not cover all age ranges. The extensive Techa River data set on 90Sr in humans (tens of thousands of measurements) is a unique source of data on long-term strontium retention for men and women of all ages at intake. These, as well as published data, were used for evaluation of age- and gender-specific parameters for a new compartment biokinetic model for strontium (Sr-AGe model). The Sr-AGe model has a similar structure to the ICRP model for the alkaline earth elements. The following parameters were mainly re-evaluated: gastrointestinal absorption and parameters related to the processes of bone formation and resorption defining calcium and strontium transfers in skeletal compartments. The Sr-AGe model satisfactorily describes available data sets on strontium retention for different kinds of intake (dietary and intravenous) at different ages (0-80 years old) and demonstrates good agreement with data sets for different ethnic groups. The Sr-AGe model can be used for dose assessment in epidemiological studies of general populations exposed to ingested strontium radioisotopes. © 2015 IOP Publishing Ltd. Source

Degteva M.O.,Urals Research Center for Radiation Medicine | Shagina N.B.,Urals Research Center for Radiation Medicine | Vorobiova M.I.,Urals Research Center for Radiation Medicine | Anspaugh L.R.,University of Utah | Napier B.A.,Pacific Northwest National Laboratory
Health Physics | Year: 2012

The Mayak Production Association was the first site for the production of weapons-grade plutonium in Russia. Early operations led to the waterborne release of radioactive materials into the small Techa River. Residents living downstream used river water for drinking and other purposes. The releases and subsequent flooding resulted in deposition of sediments along the shoreline and on floodplain soil. Primary routes of exposure were external dose from the deposited sediments and ingestion of 90Sr and other radionuclides. Study of the Techa River Cohort has revealed an increased incidence of leukemia and solid cancers. Epidemiologic studies are supported by extensive dose-reconstruction activities that have led to various versions of a Techa River Dosimetry System (TRDS). The correctness of the TRDS has been challenged by the allegation that releases of short-lived radionuclides were much larger than those used in the TRDS. Although the dosimetry system depends more upon measurements of 90Sr in humans and additional measurements of radionuclides and of exposure rates in the environment, a major activity has been undertaken to define more precisely the time-dependent rates of release and their radionuclide composition. The major releases occurred during 1950-1951 in the form of routine releases and major accidental releases. The reevaluated amount of total release is 114 PBq, about half of which was from accidents that occurred in late 1951. The time-dependent composition of the radionuclides released has also been reevaluated. The improved understanding presented in this paper is possible because of access to many documents not previously available. Copyright © 2011 Health Physics Society. Source

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