Registry for Chronic Radiation Sickness in a Cohort of Mayak PA Workers Exposed to Ionizing Radiation

2020 ◽  
Vol 65 (4) ◽  
pp. 87-96
Author(s):  
T. Azizova ◽  
M. Bannikova ◽  
E. Grigor'eva ◽  
G. Zhuntova ◽  
M. Moseeva ◽  
...  

Purpose: To present descriptive characteristics, and structure of the chronic radiation sickness (CRS) registry prospects of its use. Materials and methods: A registry for CRS diagnosed in workers of the nuclear production facility Mayak Production Association (PA) throughout the follow-up period of 1948–2018 was established within a medical and dosimetry database ‘Clinic’ of the Southern Urals Biophysics Institute. Results: The CRS registry includes 2068 cases: 1517 (73.4 %) in males and 551 (26.6 %) in females. Almost all workers (97.9 %) with CRS were hired at the Mayak PA in 1948–1954 and chronically externally and/or internally exposed to ionizing radiation. At a date of CRS diagnosis the mean cumulative red bone marrow absorbed dose of external exposure to gamma rays was 1.1 ± 0.7 Gy in males and 1.0 ± 0.6 Gy in females; the mean annual dose was 0.46 ± 0.33 Gy and 0.38 ± 0.22 Gy in males and females, respectively; maximum annual dose was 0.67 ± 0.46 Gy and 0.55 ± 0.34 Gy in males and females, respectively. The CRS frequency in the Mayak PA worker cohort significantly increased with the cumulative and mean annual RBM absorbed dose of external exposure to gamma rays. In the meantime, the CRS frequency was not associated either with a dose of external neutron exposure or with a dose of internal exposure to alpha particles from incorporated plutonium.  Conclusion: The established CRS registry providing complete high quality demographical, medical and dosimetry information, together with available biological specimens, in future will allow: the updating of dose–response and dose–time–response relationships; the estimation of latent periods, risks and dose thresholds and associated uncertainties for CRS development; certain tissue reactions in lymphoid and haematopoietic tissues; and a better understanding of their development patterns and mechanisms, taking into account non-radiation factors.

2019 ◽  
Vol 96 (9) ◽  
pp. 809-812 ◽  
Author(s):  
Leonid A. Ilin

The main aspects of radiological and nuclear terrorism have been considered in the paper. The nuclear terrorism scenario, i.e. the usage of nuclear weapons by terrorists has been emphasized to look unlikely. While the threat of radiological terrorism related to the usage of radioactive materials with the purpose of malicious exposure to the public, for example, by detonating of a “dirty bomb” with further radioactive contamination of the environment where people live, or by a hidden usage of radioactive materials appears to be rather realistic. The character and consequences of the usage of various types and sources of ionizing radiation from alpha-emitting radionuclides to gamma-, gamma-beta or beta-emitting radionuclides under external, internal or contact exposure have been discussed. The criteria of radiation impact to a person are emphasized to include both the absorbed dose and absorbed dose rate. In the case of external exposure it is necessary to consider the character of the exposure: total (whole body exposure) or local (some parts of a body) to a person; in the case of the internal exposure - features of distribution and metabolic characteristics of a specific radionuclide. Deterministic effects (acute radiation sickness, local radiation injury, chronic radiation sickness) and stochastic effects (malignant tumors, hereditary diseases) are considered as effects of the radiation exposure. Under the comparison of a radiation threat due to different pathways as a result of an act of radiological terrorism usually the first place is taken by the external exposure, followed by the internal exposure by inhalation intake of radionuclides, in the case of dispersed radioactive materials due to detonation - through wounds and burned skin surfaces; the lesser important pathway is oral intake of radionuclides. The analysis of various scenarios of the radiological terrorism shows the number of casualties with deterministic effects will be small, while the number of people with stochastic effects will not be discernible from spontaneous variation of levels of the prevalence rate of malignant tumors and hereditary diseases. The main negative factor of radiological terrorism is psychological impact of the terrorism associated with a radiation threat


Electrons generated from machine sources operated at or below an energy level of 10 MeV The eV (electronvolt) is the unit of energy used to measure and describe the energy of electrons and of other types of radiation. The energy of 1 eV is equivalent to the kinetic energy acquired by an electron on being accelerated through a potential difference of 1 V. The eV is a very small unit of energy. It is therefore more common to speak of keV (kiloelectronvolt = 1000 eV) or MeV (megaelectronvolt = 1 million eV). To convert eV to units of energy one can use the conversion 1 MeV = 1.602 X 10“ J (joule). Gamma rays and x-rays are part of the electromagnetic spectrum (Fig. 1), which reaches from the low-energy, long-wavelength radiowaves to the high-energy, short-wavelength cosmic rays. Radiowaves, infrared (IR) waves, and visible light are nonionizing radiations. Ultraviolet (UV) light can ionize only certain types of molecule under specific conditions and is generally not consid­ ered as ionizing radiation. X-rays and gamma rays are identical in their physical properties and in their effect on matter; they differ in their origin. X-rays are produced by machines and exhibit a wide continuous spectrum of radiation, whereas gamma rays come from radioactive isotopes (radionuclides) in a discon­ tinuous spectrum of radiation intensities. When ionizing radiation penetrates into a medium (e.g., the irradiated food) all or part of the radiation energy is absorbed by the medium. This is called the absorbed dose. The unit in which the absorbed dose is measured is the gray (Gy); it is equal to the absorption of 1 J (joule)/kg. One kGy (kilogray) = 1000 Gy. Formerly the dose unit rad was used. It was defined as 100 erg/g. The conversion of old to new units is based on the relationship 1000 rad = 1 Gy, or 1 krad = 10 Gy, or 1 Mrad = 10 kGy. The dose accumulated per unit of time is called the dose rate. Gamma ray sources provide a relatively low dose rate (typically 100-10,000 Gy/h, whereas

1995 ◽  
pp. 28-28

Author(s):  
A H Pakravan ◽  
S M R Aghamiri ◽  
T Bamdadian ◽  
M Gholami ◽  
M Moshfeghi

Background: Panoramic imaging is one of the most common imaging methods in dentistry. Regarding the side-effects of ionizing radiation, it is necessary to survey different aspects and details of panoramic imaging. In this study, we compared the absorbed x-ray dose around two panoramic x-ray units: PM 2002 CC Proline (Planmeca, Helsinki, Finland) and Cranex Tome (Soredex, Helsinki, Finland).Materials and Methods: In order to estimate x-ray dose, 15 thermoluminescet dosemeters (TLD-100) were placed in 3 semi-circles of 40cm, 80cm and 120cm radii. Around each unit, the number of TLDs in each semi-circle was 5 with equal intervals. The center of semicircles accords with the patient’s position. Each TLD was exposed 40 times. These dosemeters were read out with a Harshaw Model 4000 TLD Reader (USA). The calibration processing and the reading of dosemeters were performed by the Atomic Energy Organization of Iran.Results: The mean absorbed dose in three lines of PM 2002 CC Proline was 123.2±15.1, 118.0±11.0 and 108.0±9.1 µSv, (p=0.013). The results were 140.4±15.2, 120.2±10.4 and 111.6±11.2 µSv in Cranex Tome (p=0.208), which reveals no significant difference between two systems.Conclusion: There are no significant differences between the mean absorbed dose of surveyed models in panoramic imaging by two units (PM 2002 CC Proline and Cranex Tome). These results were less than occupational exposure recommended by ICRP, even at the highest calculated doses.


Author(s):  
Olena Cherniak ◽  
Nataliia Sorocolat ◽  
Iryna Kanytska ◽  
Ihor Bahaiev ◽  
Lina Fatieieva

Methods for sterilizing textile materials in a pandemic (COVID-19) and the disadvantages of these methods are presented. A number of modern scientific works related to the sterilization of textile materials in a pandemic are considered, aimed at developing a technology for sterilizing protective medical masks and medical suits by radiation methods using gamma radiation. As a result of the analysis, it was found that the use of gamma radiation is a very dangerous technological process since natural sources are used - gamma rays, radiation technologies with gamma radiation are difficult when disposing of spent energy sources and are not easy to maintain. For sterilization of textile materials, the method of ionizing radiation is proposed. The essence of the method is that the textile material is sterilized by accelerated electrons. The expediency of carrying out theoretical and experimental research has been determined. It was found that the main criterion for sterilization of textile materials is the absorbed dose. The absorbed dose is determined experimentally, but such a procedure is time-consuming and resource-intensive, and it is not always possible to carry it out. Therefore, to calculate the absorbed dose, it is proposed to apply the mathematical formula of the absorbed dose of medical textile materials, depending on the frequency of passage of pulses of the accelerated electron beam, conveyor speed and geometric parameters of textile materials, the mathematical formula will allow finding the optimal technological modes of the sterilization process. Using the mathematical model of the absorbed dose of radiation by the material with the proposed technology, taking into account the properties of materials, it is possible to calculate the modes of irradiation of various textile materials that differ in size, shape, and physical properties, which will make it possible to develop a system of normative modes for the technology of radiation-physical sterilization and to ensure the legislative and regulatory requirements of hygiene in conditions of a pandemic.


2019 ◽  
Author(s):  
Ibrahim Arman

<p>This study aimed at investigating the Effectiveness of Mantle of the Expert in creative thinking Skills among the 7<sup>th</sup> Graders. The study conducted on a sample of 7<sup>th</sup> Graders at Kober Secondary Boys School and Upper Kober Elementary Girls School. The study sample consisted of (100) students split into two groups (experimental and control). The researcher adopting the Torrance test for creative thinking the verbal image "A" by examining the tests used in the Ristow study (1988), Edwards and Baldov (1987) study, and designing a teacher book for the (engineering and measurement) unit according to the integration between the strategies of the mantle of the expert and role playing.</p> <p>This study adopted quasi-experimental design. It included two groups (experimental and controlled) in two branches (males and females) for each group. The controlled group was taught by using the traditional method whereas the experimental group by the mantle of the expert. The data analyzed using (ANCOVA) test to measure the differences in the development of creative thinking between the control and experimental groups.</p> <p>The Conclusions showed that there are statistically significant differences in the mean scores of the creative thinking test due to the way, gender and interaction between them.</p> <p>Based on the Conclusions of the study, the researcher recommends the need to use the mantles of the expert in the teaching of mathematics.</p>


2019 ◽  
Vol 65 (3) ◽  
pp. 441-446
Author(s):  
Valentina Rybkina ◽  
Tamara Azizova ◽  
Yevgeniya Grigoreva

Purpose of the study. The study is aimed to investigate skin melanoma incidence in workers occupationally exposed to radiation over a prolonged period. Materials and methods. Skin melanoma incidence was studied in a cohort of workers first employed at nuclear facility Mayak Production Association (PA) between 1948 and 1982 who had been followed up till 31.12.2013 (22,377 individuals). Mean cumulative doses from external gamma-rays over the whole follow-up period were 0.54±0.001 Sv in males and 0.44±0.002 Sv in females. Incident rates for skin melanoma were analyzed by sex, attained age, calendar period of diagnostics and radiation dose using worldwide standard and the direct standardization technique. Results. 60 skin melanoma cases (37 in males and 23 in females) were registered in the study cohort over the whole follow-up period. The standardized skin melanoma incident rate was 8.51±1.46 in males and 8.78±2.27 in females per 100000 workers revealing statistically higher rates compared to corresponding rates for general populations of the Russian Federation, Urals Federal District and Chelyabinsk region. Skin melanoma incidence was significantly increased in the period of 1994 - 2013 as compared to the period of 1974 - 1993. Skin melanoma incidence excess in females was greater than that for males. Skin melanoma incidence increment in females was mostly driven by modifications of disease occurrence risk while in males it was driven by a combined effect of age pattern modifications in the study cohort and increase of disease risk. Conclusions. Skin melanoma incidence rates in the cohort of workers occupationally exposed to ionizing radiation over a prolonged period were associated with sex and attained age workers and the calendar period of diagnostics. No significant association of skin melanoma incidence with dose from external gamma-rays was observed. A significantly increasing trend was observed for skin melanoma incidence by the end of the follow-up in both males and females.


1998 ◽  
Author(s):  
Mira M. Kossenko ◽  
Lidiya A. Nikolayenko ◽  
Svetlana B. Yepifanova ◽  
Yevghenya V. Ostroumova

Author(s):  
Roya Kazemi ◽  
Seyed Jalal Hosseinimehr

Objective: Pioglitazone (PG) is used to control high blood sugar in patients with type 2 diabetes mellitus. PG acts as a peroxisome proliferator-activated receptor γ agonist. In addition to the insulin-sensitizing effect, PG possesses anti-inflammatory effect. In this study, the protective effect of PG was evaluated against DNA damage induced by ionizing radiation in human healthy lymphocytes. Methods: The microtubes containing human whole blood were treated with PG at various concentrations (1-50 μM) for three hours. Then, the blood samples were irradiated with X-ray. Lymphocytes were cultured for determining the frequency of micronuclei as a genotoxicity biomarker in binucleated lymphocytes. Results: The mean percentage of micronuclei was significantly increased in human lymphocytes when were exposed to IR, while it was decreased in lymphocytes pre-treated with PG. The maximum reduction in the frequency of micronuclei in irradiated lymphocytes was observed at 5 μM of PG treatment (48% decrease). Conclusion: The anti-inflammatory property is suggested the mechanism action of PG for protection human lymphocytes against genotoxicity induced by ionizing radiation.


1982 ◽  
Vol 47 (7) ◽  
pp. 1780-1786 ◽  
Author(s):  
Rostislav Kudláček ◽  
Jan Lokoč

The effect of gamma pre-irradiation of the mixed nickel-magnesium oxide catalyst on the kinetics of hydrogenation of maleic acid in the liquid phase has been studied. The changes of the hydrogenation rate are compared with the changes of the adsorbed amount of the acid and with the changes of the solution composition, activation energy, and absorbed dose of the ionizing radiation. From this comparison and from the interpretation of the experimental data it can be deduced that two types of centers can be distinguished on the surface of the catalyst under study, namely the sorption centres for the acid and hydrogen and the reaction centres.


1991 ◽  
Vol 48 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
Jan Henning L'Abée-Lund

I compared adult size and sea age at sexual maturity among nine populations of anadromous brown trout, Salmo trutta, in two Norwegian rivers to determine the extent of inter- and intrariverine variations. Variation in the mean length of spawners and in the mean sea age at sexual maturity were mainly dependent on the variations found within rather than between rivers. Mean lengths and mean age at maturity of males increased significantly with increasing altitude of the spawning area and with migration distance in freshwater. In females, positive significant correlations were found with mean lengths and altitude of the spawning area and with mean sea age at maturity and both spawning site altitude and migration distance. Mean lengths and ages of males and females were not significantly correlated with the rate of water discharge in the streams during spawning. The size of gravel substrate for spawning was of minor importance in explaining interpopulation variation in mean female size. The increase noted in mean length and in mean sea age at maturity of both males and females is probably an adaptation to greater energy expenditure to reach the uppermost natal spawning areas.


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