The influence of low-level radiation on nucleolus activity of cyprinidae embryos

International Nuclear Information System (INIS)

Arkhipchuk, V.V.

1990-01-01

The number and sizes of nucleoli in embryos of Cyprinus carpio and Carassius auratus gibelio exposed to low-level radiation at a dose-rate of 10 μ Gy/h and down were larger than those on non-irradiated controls

Regulation of radiation-induced protein kinase Cδ activation in radiation-induced apoptosis differs between radiosensitive and radioresistant mouse thymic lymphoma cell lines

International Nuclear Information System (INIS)

Nakajima, Tetsuo; Yukawa, Osami; Tsuji, Hideo; Ohyama, Harumi; Wang, Bing; Tatsumi, Kouichi; Hayata, Isamu; Hama-Inaba, Hiroko

2006-01-01

Protein kinase Cδ (PKCδ) has an important role in radiation-induced apoptosis. The expression and function of PKCδ in radiation-induced apoptosis were assessed in a radiation-sensitive mouse thymic lymphoma cell line, 3SBH5, and its radioresistant variant, XR223. Rottlerin, a PKCδ-specific inhibitor, completely abolished radiation-induced apoptosis in 3SBH5. Radiation-induced PKCδ activation correlated with the degradation of PKCδ, indicating that PKCδ activation through degradation is involved in radiation-induced apoptosis in radiosensitive 3SBH5. In radioresistant XR223, radiation-induced PKCδ activation was lower than that in radiosensitive 3SBH5. Cytosol PKCδ levels in 3SBH5 decreased markedly after irradiation, while those in XR223 did not. There was no apparent change after irradiation in the membrane fractions of either cell type. In addition, basal cytosol PKCδ levels in XR223 were higher than those in 3SBH5. These results suggest that the radioresistance in XR223 to radiation-induced apoptosis is due to a difference in the regulation of radiation-induced PKCδ activation compared to that of 3SBH5. On the other hand, Atm -/- mouse thymic lymphoma cells were more radioresistant to radiation-induced apoptosis than wild-type mouse thymic lymphoma cells. Irradiated wild-type cells, but not Atm -/- cells, had decreased PKCδ levels, indicating that the Atm protein is involved in radiation-induced apoptosis through the induction of PKCδ degradation. The decreased Atm protein levels induced by treatment with Atm small interfering RNA had no effect on radiation-induced apoptosis in 3SBH5 cells. These results suggest that the regulation of radiation-induced PKCδ activation, which is distinct from the Atm-mediated cascade, determines radiation sensitivity in radiosensitive 3SBH5 cells

Time course of cerebellar catalase levels after neonatal ionizing radiations

International Nuclear Information System (INIS)

Di Meglio, A.; Caceres, L.; Zieher, L.M.; Guelman, L.R.

2005-01-01

Full text: Reactive oxygen species are physiologically generated as a consequence of aerobic respiration, but this generation is increased in response to external stimuli, including ionizing radiation. The central nervous system (CNS) is vulnerable to oxidative stress due to its high oxygen consumption rate, its high level of polyunsaturated fatty acids and low levels of antioxidant defences. An important compound of this defence system is the antioxidant enzyme catalase, an heme protein that removes hydrogen peroxide from the cell by catalyzing its conversion to water. The aim of the present work was to study if catalase is susceptible to oxidative stress generated by ionizing radiation on the cerebellum. Neonatal rats were irradiated with 5 Gy of X rays and the levels of catalase were measured at 15, 30 and 60 days of age. Results show that there is a decrease in the activity of catalase in irradiated cerebellum at 15 (% respect the control, 65.6 ± 14.8), 30 (51.35± 5.8%), and 60 days (9.3 ± 0.34%). Catalase activity at 15 and 30 days has shown to be positively correlated with the radiation-induced decrease in tissue's weight, while at 60 days there is an extra decrease. It would be suggested that, at long term, radiation exposure might induce, in addition to cerebellar atrophy, the oxidation of the radiosensitive heme group of the enzyme, leading to its inactivation. In conclusion, the antioxidant enzyme catalase has shown to be especially sensitive to ionizing radiation. (author)

BEIR-III report and the health effects of low-level radiation

International Nuclear Information System (INIS)

Fabrikant, J.I.

1980-01-01

The present BEIR-III Committee has not highlighted any controversy over the health effects of low-level radiation. In its evaluation of the experimental data and epidemiological surveys, the Committee has carefully reviewed and assessed the value of all the available scientific evidence for estimating numerical risk coefficients for the health hazards to human populations exposed to low levels of ionizing radiation. Responsible public awareness of the possible health effects of ionizing radiations from medical and industrial radiation exposure, centers on three important matters of societal concern: (1) to place into perspective the extent of harm to the health of man and his descendants to be expected in the present and in the future from those societal activities involving ionizing radiation; (2) to develop quantitative indices of harm based on dose-effect relationships; such indices could then be used with prudent caution to introduce concepts of the regulation of population doses on the basis of somatic and genetic risks; and (3) to identify the magnitude and extent of radiation activities which could cause harm, to assess their relative significance, and to provide a framework for recommendations on how to reduce unnecessary radiation exposure to human populations. The main difference of the BEIR Committee Report is not so much from new data or new interpretations of existing data, but rather from a philosophical approach and appraisal of existing and future radiation protection resulting from an atmosphere of constantly changing societal conditions and public attitudes

Effect of sublethal levels of ionizing radiation on a predator-prey interaction

International Nuclear Information System (INIS)

Chee, P.C.

1976-01-01

The predator-prey interaction studied was that between the largemouth bass (Micropterus salmoides) and the fathead minnow (Pimephales promelas) in an artificial test environment. Experiments were first conducted to determine the 50% lethal dose at 30 days of the minnow. Three different dose rates were used to test the effect of dose rate on the 50% lethal dose value. After the 50% lethal dose was determined the predator-prey interaction experiment was conducted using 30% of the 50% lethal dose as the highest radiation dose, this dose being considered the upper limit to sublethal radiation levels. A 4 x 4 Latin square design was chosen for the experiment, with four treatment levels (control plus three radiation levels) and four replicates. In each test 10 prey minnow were offered to one predator bass and the number of prey left after 14 days was the parameter of interest. A predator-prey interaction experiment using a single high level of radiation and two types of controls as conducted to ascertain the ability of the test environment to detect changes in the predator-prey interaction. The two types of controls were irradiated prey not exposed to predation and non-irradiated prey exposed to predation. An experiment was also conducted to test the correlation between the physical activity patterns of minnow and different doses of radiation. At a dose rate of 37.8 rad/min the 50% lethal dose at 30 days for minnow was found to be 2650 rad. It was found that dose rate had a strong influence on the 50% lethal dose. In the predator-prey interaction test it was found that the 14-day survival rate of prey was unaffected by sublethal levels of ionizing radiation. No significant correlation was detected between the physical activity patterns of minnow and radiation dose

Elevation of telomerase activity in chronic radiation ulcer of human skin

International Nuclear Information System (INIS)

Li Xiaoying; Zhao Po; Wang Dewen; Yang Zhixiang

1997-01-01

Objective: To investigate the levels of telomerase activity in chronic radiation ulcers of human skin and the possible relationship between the enzyme and cancer transformation. Method: Using nonisotopic telomere repeat amplification protocol (TRAP), detections were performed in 20 cases of chronic radiation ulcers of human skin, 5 cases of normal skin tissues and 5 cases of carcinoma. Results: The positive rates for telomerase activity were 30.0%(6/20), 0(0/5) and 100%(5/5) in chronic radiation ulcers of human skin, normal skin and carcinoma, respectively. The telomerase activity in radiation ulcer was weaker than in carcinoma. Conclusion: The telomerase activity assay might be used as a marker for predicting the prognosis and the effect of treatment in chronic radiation ulcer of human skin

Transcription and activity of antioxidant proteins after ionization irradiation of radiation-resistant and radiation-sensitive mice

International Nuclear Information System (INIS)

Hardmeier, R.

1998-03-01

The involvernent of antioxidant proteins catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH px), and thioredoxin (TRX) in radiobiological processes has been described at the enzyme activity level. We were interested in examining the transcription of these proteins in a mammalian system following ionizing irradiation. In order to answer the question whether radiation effects in sensitive mice (Balb/c) (RS) showed differences at the transcriptional level from radiation effects in resistant mice (C3H) (RR). We exposed the whole body of these strains to X/rays doses of 2, 4, and 6 Gy and sacrificed the animals 5, 15, and 30 minutes after irradiation. The mRNA was isolated from liver and hybrized with probes for antioxidant enzymes and thioredoxin, β-actin was used as a housekeeping gene control. Antioxidant enzyme activities were determined by standard assays. Parameters for aromatic hydroxylation (o-Tyr) and lipid peroxidation (MDA) were determined by HPLC methods. Antioxidant transcription was unchanged in contrast to antioxidant activities. SOD and CAT activities were elevated within 15 minutes in RR animals but not in RS at all radiation doses. Glutathione peroxidase activity was not different between RR and RS mice, and was only moderately elevated after irradiation. No significant differences were found between RR and RS animals at the oxidation level, although a radiation dose-dependent increase of oxidation products was detected in both groups. Quantification of thioredoxin mRNA revealed that RR mice transcribed this protein at a significantly higher level at an earlier time point (5 minutes) than did RS mice. This delay may well be responsible for the radioresistance although no quantitative differences were found. As unchanged transcription of antioxidant enzymes could not have been responsible for the increased antioxidant enzyme activities, preformed antioxidant enzymes may have been released by irradiation. This would be in agreement

SGR-76 gamma radiation level indicator

International Nuclear Information System (INIS)

Chubinskij-Nadezhdin, I.V.

1978-01-01

The design of a gamma-radiation level indicator is described; the instrument is part of a mobile radiometric laboratory (MRL). The design of the instrument permits gamma-radiation dose rates recording at 0.2-200 R/hr, and signals on gamma-background levels. The instrument has two separate threshold levels of signalling actuation. The light signalling at the first level is precautionary, and the sound signalling at the second level indicates the necessity of taking a decision as to whether or not the MRL can remain in the gamma-radiation field. Halogenic counters operating in a current mode are used as detectors. The basic error in recording the dose rate amounts to +-25%. Overall dimensions of the instrument 150x280x100 mm; weight less than 2.5 kg

Can low-level radiation cause cancer?

International Nuclear Information System (INIS)

Trosko, J.E.

1995-01-01

Health in a multicellular organism is maintained by homeostatic processes. Disruption of these homeostatic controls at the molecular, biochemical, cellular, and organ systems levels can be brought about by irreversible changes in the genetic material (mutagenesis), cell death (cytotoxicity), or reversible changes in the expression of genes at the transcriptional, translational, or posttranslational levels (epigenesis). While radiation is known to induce DNA damage/mutations, cell, death and epigenetic changes, in addition to cancers that are found in radiation-exposed animals, experimentally, and in humans, epidemiologically, the question is, At low-level exposure, what is the risk that cancers are open-quotes causedclose quotes by the radiation?

Course of radiation protection: technical level

International Nuclear Information System (INIS)

2002-01-01

The course handbook on radiation protection and nuclear safety, technical level prepared by scientists of the Nuclear Regulatory Authority (ARN) of the Argentina Republic, describes the subjects in 19 chapters and 2 annexes. These topics detailed in the text have the following aspects: radioactivity elements, interaction of the radiation and the matter, radio dosimetry, internal contamination dosimetry, principles of radiation detection, biological radiation effects, fundamentals of radiation protection, dose limits, optimization, occupational exposure, radiation shielding, radioactive waste management, criticality accidents, safe transport of radioactive materials, regulatory aspects

Low level radiation: biological effects

International Nuclear Information System (INIS)

Loken, M.K.

1983-01-01

It is imperative that physicians and scientists using radiations in health care delivery continue to assess the benefits derived, vs. potential risk, to patients and radiation workers being exposed to radiation in its various forms as part of our health delivery system. Insofar as possible we should assure our patients and ourselves that the benefits outweigh the potential hazards involved. Inferences as to the possible biological effects of low level radiation are generally based on extrapolations from those effects observed and measured following acute exposures to considerably higher doses of radiation. Thus, in order to shed light on the question of the possible biological effects of low level radiation, a wide variety of studies have been carried out using cells in culture and various species of plant and animal life. This manuscript makes reference to some of those studies with indications as to how and why the studies were done and the conclusions that might be drawn there from. In addition reference is made to the handling of this information by scientists, by environmentalists, and by the news media. Unfortunately, in many instances the public has been misled by what has been said and/or written. It is hoped that this presentation will provide an understandable and reasonable perspective on the various appropriate uses of radiation in our lives and how such uses do provide significant improvement in our health and in our quality of life

Background radiation levels and standards for protection from ionizing radiations

International Nuclear Information System (INIS)

Farai, I.

1999-01-01

Apart from the amount of radiation which a worker may receive while he performs his work, he is also exposed to radiation because of the nature of his environment. In other words, all individuals are subject to some irradiation even though they may not work with radioactive substances. This source of radiation exposure is often referred to as background radiation. In most environments, it is low-level and can be grouped into two natural and man-made. Background radiation provides the basis on which allowable exposure limits for workers are drawn

A conceptual framework for managing radiation dose to patients in diagnostic radiology using reference dose levels

International Nuclear Information System (INIS)

Almen, Anja; Baath, Magnus

2016-01-01

The overall aim of the present work was to develop a conceptual framework for managing radiation dose in diagnostic radiology with the intention to support optimisation. An optimisation process was first derived. The framework for managing radiation dose, based on the derived optimisation process, was then outlined. The outset of the optimisation process is four stages: providing equipment, establishing methodology, performing examinations and ensuring quality. The optimisation process comprises a series of activities and actions at these stages. The current system of diagnostic reference levels is an activity in the last stage, ensuring quality. The system becomes a reactive activity only to a certain extent engaging the core activity in the radiology department, performing examinations. Three reference dose levels-possible, expected and established-were assigned to the three stages in the optimisation process, excluding ensuring quality. A reasonably achievable dose range is also derived, indicating an acceptable deviation from the established dose level. A reasonable radiation dose for a single patient is within this range. The suggested framework for managing radiation dose should be regarded as one part of the optimisation process. The optimisation process constitutes a variety of complementary activities, where managing radiation dose is only one part. This emphasises the need to take a holistic approach integrating the optimisation process in different clinical activities. (authors)

Clinical Advances of Hypoxia-Activated Prodrugs in Combination With Radiation Therapy.

Science.gov (United States)

Mistry, Ishna N; Thomas, Matthew; Calder, Ewen D D; Conway, Stuart J; Hammond, Ester M

2017-08-01

With the increasing incidence of cancer worldwide, the need for specific, effective therapies is ever more urgent. One example of targeted cancer therapeutics is hypoxia-activated prodrugs (HAPs), also known as bioreductive prodrugs. These prodrugs are inactive in cells with normal oxygen levels but in hypoxic cells (with low oxygen levels) undergo chemical reduction to the active compound. Hypoxia is a common feature of solid tumors and is associated with a more aggressive phenotype and resistance to all modes of therapy. Therefore, the combination of radiation therapy and bioreductive drugs presents an attractive opportunity for synergistic effects, because the HAP targets the radiation-resistant hypoxic cells. Hypoxia-activated prodrugs have typically been precursors of DNA-damaging agents, but a new generation of molecularly targeted HAPs is emerging. By targeting proteins associated with tumorigenesis and survival, these compounds may result in greater selectivity over healthy tissue. We review the clinical progress of HAPs as adjuncts to radiation therapy and conclude that the use of HAPs alongside radiation is vastly underexplored at the clinical level. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Legal aspects of radiation protection at the international level

International Nuclear Information System (INIS)

Papazian, J.

1981-01-01

A review is made of the respective activities of the various international organizations concerned with radiation protection at the legal level. These organizations are either non-governmental (I.C.R.P., I.C.R.U.) or governmental in which case they can act at the world (U.N., I.A.E.A., I.L.O., W.H.O.) or regional level (N.E.A., EURATOM, COMECOM). The legal impact of the recommendations or directives they issue is specified [fr

Radiation-activated sensor

International Nuclear Information System (INIS)

Nirschl, J.C.

1976-01-01

A sensing system is described for use in a remote location which detects electromagnetic radiation energy, the system being self-activating, turning itself automatically on and off, as a function of radiation intensity across the detector. In essence, when no radiation is present across the detector, the system will consume no power, the switches and MOSFET discriminator being essentially in an ''off'' position. Radiation across the detector provides a current to an input capacitance which when charged turns on the switch and the MOSFET discriminator. A switch driver produces an output pulse showing the presence of radiation; the system then shuts off awaiting the next radiation input. Since the sensor system uses virtually no power unless radiation is present, it is ideally suited for use in remote environments where battery power and size is a predominant consideration. 2 claims, 3 drawing figures

Radiation levels on empty cylinders containing heel material

Energy Technology Data Exchange (ETDEWEB)

Shockley, C.W. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

1991-12-31

Empty UF{sub 6} cylinders containing heel material were found to emit radiation levels in excess of 200 mr/hr, the maximum amount stated in ORO-651. The radiation levels were as high as 335 mr/hr for thick wall (48X and 48Y) cylinders and 1050 mr/hr for thin wall (48G and 48H) cylinders. The high readings were found only on the bottom of the cylinders. These radiation levels exceeded the maximum levels established in DOT 49 CFR, Part 173.441 for shipment of cylinders. Holding periods of four weeks for thick-wall cylinders and ten weeks for thin-wall cylinders were established to allow the radiation levels to decay prior to shipment.

A CONCEPTUAL FRAMEWORK FOR MANAGING RADIATION DOSE TO PATIENTS IN DIAGNOSTIC RADIOLOGY USING REFERENCE DOSE LEVELS.

Science.gov (United States)

Almén, Anja; Båth, Magnus

2016-06-01

The overall aim of the present work was to develop a conceptual framework for managing radiation dose in diagnostic radiology with the intention to support optimisation. An optimisation process was first derived. The framework for managing radiation dose, based on the derived optimisation process, was then outlined. The outset of the optimisation process is four stages: providing equipment, establishing methodology, performing examinations and ensuring quality. The optimisation process comprises a series of activities and actions at these stages. The current system of diagnostic reference levels is an activity in the last stage, ensuring quality. The system becomes a reactive activity only to a certain extent engaging the core activity in the radiology department, performing examinations. Three reference dose levels-possible, expected and established-were assigned to the three stages in the optimisation process, excluding ensuring quality. A reasonably achievable dose range is also derived, indicating an acceptable deviation from the established dose level. A reasonable radiation dose for a single patient is within this range. The suggested framework for managing radiation dose should be regarded as one part of the optimisation process. The optimisation process constitutes a variety of complementary activities, where managing radiation dose is only one part. This emphasises the need to take a holistic approach integrating the optimisation process in different clinical activities. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Radiation levels at CERN's injectors and their impact on electronic equipment

CERN Document Server

AUTHOR|(SzGeCERN)649218; Brugger, Markus

2013-01-01

Electronic devices operating in hostile radiation environments, such as those found close to high-energy particle accelerators, can suffer from different types of radiation induced failures. At CERN, the mixed particle and energy radiation fields present at the Large Hadron Collider (LHC) and its injector chain can give rise to both stochastic and cumulative effects causing radiation induced failures of exposed electronics and materials, thus directly impacting components and system lifetimes, as well as maintenance requirements. With its original focus on the LHC, the Radiation to Electronics (R2E) project has been successfully implementing mitigation actions in order to avoid accelerator downtime due to radiation induced failures on active electronics. In a next step, the emphasis is put on CERN's injector chain, collecting the respective available information about radiation levels, the definition of additional monitoring requirements and a critical analysis of present and future equipment installations. T...

Health effects of low-level ionizing radiation

International Nuclear Information System (INIS)

Fabrikant, J.I.

1979-04-01

It is now assumed that any exposure to radiaton at low levels of dose carries some risk of deleterious effects. How low this level may be, or the probability or magnitude of the risk, still are not known. Our best scientific knowledge and advice are essential for the protection of the public health, for the effective application of new technologies in medicine and industry and for guidance in the production of nuclear energy. Unless man wishes to dispense with those activities which inevitably involve exposure to low levels of ionizing radiations, he must recognize that some degree of risk to health, however small, exists. A pragmatic appraisal of how man wishes to continue to derive the benefits of health and happiness from such activities involving ionizing radiaton in times of everchanging conditions and public attitudes in our resource-limited society is the task which lies before all of us - all men and women of our society, of science and of medicine, and of law and government - now and in the future

Responses to the low-level-radiation controversy

International Nuclear Information System (INIS)

Bond, V.P.

1981-01-01

Some data sets dealing with the hazards of low-level radiation are discussed. It is concluded that none of these reports, individually or collectively, changes appreciably or even significantly the evaluations of possible low-level radiation effects that have been made by several authoritative national and international groups

Radiation hormesis: an outcome of exposure to low level ionizing radiation

International Nuclear Information System (INIS)

Kant, Krishan

2012-01-01

Ionizing radiation is a benign environmental agent at background levels. Human population is always exposed to ionizing radiation from natural sources. Important sources are cosmic rays which come from outer space and from the surface of the sun, terrestrial radionuclides which occur in the earths crust in various geological formations in soils, rocks, building materials, plants, water, food, air and in the human body itself. With the increasing use of radiation in health facilities, scientific research, industry and agriculture, the study of impact of low-level ionizing radiation on environment and possible health effects on future generations has been a cause of concern in recent years. As regards the effects, it is established fact that high doses of ionizing radiation are harmful to health, there exists, however, a substantial controversy regarding the effects of low doses of ionizing radiation (LLIR). In the present paper, brief review of the available literature, data and reports on stimulation by low-dose irradiation and recent data supporting radiation hormesis. A linear quadratic model has been given illustrating the validity of radiation hormesis, besides the comparison of the dose rates arising from natural and manmade sources to the Indian population. This overview summarizes various reports

[Effect of low-intensity 900 MHz frequency electromagnetic radiation on rat liver and blood serum enzyme activities].

Science.gov (United States)

Nersesova, L S; Petrosian, M S; Gazariants, M G; Mkrtchian, Z S; Meliksetian, G O; Pogosian, L G; Akopian, Zh I

2014-01-01

The comparative analysis of the rat liver and blood serum creatine kinase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and purine nucleoside phosphorylase post-radiation activity levels after a total two-hour long single and fractional exposure of the animals to low-intensity 900 MHz frequency electromagnetic field showed that the most sensitive enzymes to the both schedules of radiation are the liver creatine kinase, as well as the blood serum creatine kinase and alkaline phosphatase. According to the comparative analysis of the dynamics of changes in the activity level of the liver and blood serum creatine kinase, alanine aminotransferase, aspartate aminotransferase and purine nucleoside phosphorylase, both single and fractional radiation schedules do not affect the permeability of a hepatocyte cell membrane, but rather cause changes in their energetic metabolism. The correlation analysis of the post-radiation activity level changes of the investigated enzymes did not reveal a clear relationship between them. The dynamics of post-radiation changes in the activity of investigated enzyme levels following a single and short-term fractional schedules of radiation did not differ essentially.

Radiation exposure of airplane crews. Exposure levels

International Nuclear Information System (INIS)

Bergau, L.

1995-01-01

Even at normal height levels of modern jet airplanes, the flying crew is exposed to a radiation level which is higher by several factors than the terrestrial radiation. There are several ways in which this can be hazardous; the most important of these is the induction of malignant growths, i.e. tumours. (orig./MG) [de

Electromagnetic Radiation Disturbed the Photosynthesis of Microcystis aeruginosa at the Proteomics Level.

Science.gov (United States)

Tang, Chao; Yang, Chuanjun; Yu, Hui; Tian, Shen; Huang, Xiaomei; Wang, Weiyi; Cai, Peng

2018-01-11

Photosynthesis of Microcystis aeruginosa under Electromagnetic Radiation (1.8 GHz, 40 V/m) was studied by using the proteomics. A total of 30 differentially expressed proteins, including 15 up-regulated and 15 down-regulated proteins, were obtained in this study. The differentially expressed proteins were significantly enriched in the photosynthesis pathway, in which the protein expression levels of photosystems II cytochrome b559 α subunit, cytochrome C550, PsbY, and F-type ATP synthase (a, b) decreased. Our results indicated that electromagnetic radiation altered the photosynthesis-related protein expression levels, and aimed at the function of photosynthetic pigments, photosystems II potential activity, photosynthetic electron transport process, and photosynthetic phosphorylation process of M. aeruginosa. Based on the above evidence, that photoreaction system may be deduced as a target of electromagnetic radiation on the photosynthesis in cyanobacteria; the photoreaction system of cyanobacteria is a hypothetical "shared target effector" that responds to light and electromagnetic radiation; moreover, electromagnetic radiation does not act on the functional proteins themselves but their expression processes.

Radiation doses and possible radiation effects of low-level, chronic radiation in vegetation

International Nuclear Information System (INIS)

Rhoads, W.A.; Franks, L.A.

1975-01-01

Measurements were made of radiation doses in soil and vegetation in Pu-contaminated areas at the Nevada Test Site with the objective of investigating low-level, low-energy gamma radiation (with some beta radiation) effects at the cytological or morphological level in native shrubs. In this preliminary investigation, the exposure doses to shrubs at the approximate height of stem apical meristems were estimated from 35 to 140 R for a ten-year period. The gamma exposure dose estimated for the same period was 20.7 percent +- 6.4 percent of that recorded by the dosimeters used in several kinds of field instrument surveys. Hence, a survey instrument reading made at about 25 cm in the tops of shrubs should indicate about 1 / 5 the dosimeter-measured exposures. No cytology has yet been undertaken because of the drought since last winter. (auth)

Influence of ionizing radiation on gastrointestinal peptide levels

Energy Technology Data Exchange (ETDEWEB)

Wysocki, J.; Esposito, V.; Linard, C. [CEA Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire

1997-03-01

Exposure of the gut to ionising radiation may induce gastrointestinal damage and dysfunction. Early effects such as nausea, vomiting and diarrhea, anorexia may be observed within the first 24 h after irradiation. Such symptoms are seen even with doses as low as 1 Gy. later effects and the onset of the gastrointestinal syndrome are seen at higher doses (10 Gy) and include gastric emptying inhibition, intestinal hemorrhages, disturbances in water and electrolytes balance and septicemia. The severity of which depends on the nature, dose and dose rate received. The mechanism underlying these changes was unclear; it has long been known that exposure to ionising radiation affects intestinal morphology usually because of inhibition of mitotic activity at the level of the crypt enterocyst. The various physiological functions of the gastrointestinal tract are controlled by a wide variety of agents as neurotransmitters, neuropeptides. Radiation induces alterations in hormonal release and response. The present study carried out in the rat focuses on Gastrin Releasing Peptide (GRP), a gastrointestinal neuropeptide present in the central nervous system and in the gut endocrine cells were released into blood. The GRP controls food intake, pancreatic enzyme secretions, gastric emptying, intestinal motility and cellular proliferation. The aim was to investigate the effects of gamma and neutron/gamma on plasma and gastrointestinal tissue levels of GRP

Chromosome Aberration on High Level Background Natural Radiation Areas

International Nuclear Information System (INIS)

Yanti-Lusiyanti; Zubaidah-Alatas

2001-01-01

When the body is irradiated, all cells can suffer cytogenetic damage that can be seen as structural damage of chromosome in the lymphocytes. People no matter where they live in world are exposed to background radiation from natural sources both internal and external such as cosmic radiation, terrestrial radiation, cosmogenic radiation radon and thoron. Level of area natural ionizing radiation is varies depending on the altitude, the soil or rock conditions, particular food chains and the building materials and construction features. Level of normal areas of background exposure is annual effective dose 2.4 mSv and the high level areas of background exposure 20 mSv. This paper discuses the frequency of aberration chromosome especially dysenteries in several countries having high level radiation background. It seems that frequency of chromosome aberrations increase, generally with the increase of age of the people and the accumulated dose received. (author)

Measurement and evaluation of the external radiation level at reactor Kartini

International Nuclear Information System (INIS)

Atok Suhartanto; Suparno

2013-01-01

Measurement and evaluation of external radiation level at reactor Kartini in 2012 has been done. The purpose of this activity is to know the external radiation level as a result of the radioactive or radiation source usage, toward the operational of limit condition. The measurement is using survey meter Inspector 11086, factor of calibration 0.991 mR/h, at 9 locations is: Control room area, Thermal column facilities, Demineralizer, Beamport radiography facilities, bulk shielding Deck, Subcritical facilities, Reactor hall, Deck reactor and on the surface of reactor water tank . The highest room average measurement result in 9 working areas for 12 months continuously are at the reactor tank location is between 13.05±1.09 (xlO -2 mSv/hour) to 16.80±1.40 (x10 -2 mSv/hour), and the lowest measurement result in 1 location (control room) is 0.02±0.005 (x10 -2 mSv/hour) to 0.035±0.009 (x10 -2 mSv/hour). The Kartini reactor is involved in the control area which has potentially contaminated and has radiation exposure at the level of 6 mSv/year. Radiation Protection Officer that work in interval will received radiation exposure dosage of 8.4 mSv/year. This dosage is still below the Below Dosage Value which is recommended by, BAPETEN decree No, 4, 2013 about Protection and Radiation Safety in Nuclear Energy Application at 20 mSv/year. The result of the evaluation above shows that the external radiation which occurred in each area is still below the operational of limit condition that is written on the Kartini reactor safety analysis report, on document number: C7/05/B2/LAK/2010, revision 7. So that the workplace is safe for work monitored. (author)

Environmental policy. Ambient radioactivity levels and radiation doses in 1998

International Nuclear Information System (INIS)

1999-11-01

The report contains information on the natural (background) radiation exposure (chapter II), the natural radiation exposure as influenced by anthropogenic effects (chapter III), the anthropogenic radiation exposure (chapter IV), and the radiation doses to the environment and the population emanating from the Chernobyl fallout (chapter V). The natural radiation exposure is specified referring to the contributions from cosmic and terrestrial background radiation and intake of natural radioactive substances. Changes of the natural environment resulting from anthropogenic effects (technology applications) inducing an increase in concentration of natural radioactive substances accordingly increase the anthropogenic radiation exposure. Indoor air radon concentration in buildings for instance is one typical example of anthropogenic increase of concentration of natural radioactivity, primarily caused by the mining industry or by various materials processing activities, which may cause an increase in the average radiation dose to the population. Measurements so far show that indoor air concentration of radon exceeds a level of 200 Bq/m 3 in less than 2% of the residential buildings; the EUropean Commission therefore recommends to use this concentration value as a maximum value for new residential buildings. Higher concentrations are primarily measured in areas with relevant geological conditions and abundance of radon, or eg. in mining areas. (orig./CB) [de

Radiation protection activities around the CERN accelerators

International Nuclear Information System (INIS)

Fasso, A.

1996-01-01

In 1995 several operational circumstances required careful watching by the Radiation Protection Group. Most of these were linked with new or recently started CERN activities: for instance the increasing importance assumed by ISOLDE operation and the breakdowns encountered which have given rise to contamination of the target region and to activity releases. In the SPS ring, several difficulties were brought about by a toilsome installation of a new interlock system, while lead ion operation marked the end of the year, as usual, with higher radiation levels in the SPS experimental areas, despite the fact that existing shielding had been improved. Also at the end of the year, the increase of LEP beam energy to 68 GeV caused a rise of dose rate levels from synchrotron radiation. This was expected, but studies are still needed to assess the full implications for different aspects of radiation protection. On the other hand, the ageing of magnet coils and other equipment (insulators, cables, flexible pipes), aggravated by the high proton beam intensities, has resulted in an increasing frequency of failures (mainly water leaks) both at the PS and at the SPS. If the apparent trend is confirmed, difficulties could be expected in the future for two reasons: the shortage of specialized staff, some of them approaching the CERN dose limit of 15 mSv annually, who can be assigned to repair work; and the lack of spare parts to replace the damaged items. Luckily, the long cooling times following high intensity proton runs provided by the operation with heavy-ions and by the winter shutdown mitigate this situation

Overview of the hazards of low-level exposure to radiation

International Nuclear Information System (INIS)

Ritenour, E.R.

1984-01-01

In this chapter the authors are concerned with low-level radiation, doses of ionizing radiations that are ten to thousands of times smaller than those required to contract ARS. Low-level radiation may be defined as an absorbed dose of 10 rem or less delivered over a short period of time. A larger dose delivered over a long period of time, for instance, 50 rem in 10 years, may also be considered low level. The definition is purposely loose so as to cover a wide variety of sources of radiation exposure, such as natural background (100 mrem/year) occupational exposures (<5 rem/year), and medical applications, such as diagnostic radiography (<1 rem). Low-level radiation exposure does not produce ARS. The health effects that may be of concern in regard to low-level radiation are its long-term sequelae. Studies of survivors of high-level radiation exposure (both human and laboratory animals) have indicated that there are three health effects that should be examined at low levels of exposure: induction of cancer, birth abnormalities (from irradiation in utero), and genetic effects. No other long-term effects of low-level exposure have been conclusively demonstrated in animals or humans

Low dose radiation enhances the Locomotor activity of D. melanogaster

Energy Technology Data Exchange (ETDEWEB)

Seong, Ki Moon; Lee, Buyng Sub; Nam Seon Young; Kim, Ji Young; Yang, Kwang Hee; Choi, Tae In; Kim, Cha Soon [Radiation Effect Research Team, Radiation Health Research Institute, Korea Hydro and Nuclear Power Co., Ltd., Gyeongju (Korea, Republic of)

2013-04-15

Mild stresses at low level including radiation can induce the beneficial effects in many vertebrate and invertebrate species. However, a large amount of studies in radiation biology have focused on the detrimental effects of high dose radiation (HDR) such as the increased incidence of cancers and developmental diseases. Low dose radiation (LDR) induces biologically favorable effects in diverse fields, for example, cancer development, genomic instability, immune response, and longevity. Our previous data indicated that LDR promotes cells proliferation of which degree is not much but significant, and microarray data explained that LDR irradiated fruit flies showing the augmented immunity significantly changed the program for gene expression of many genes in Gene Ontology (GO) categories related to metabolic process. Metabolic process in development one of major contributors in organism growth, interbreeding, motility, and aging. Therefore, it is valuable to examine whether LDR change the physiological parameters related to metabolism, and how LDR regulates the metabolism in D. melanogaster. In this study, to investigate that LDR influences change of the metabolism, a representative parameter, locomotor activity. In addition, the activation of several cellular signal molecules was determined to investigate the specific molecular mechanism of LDR effects on the metabolism. We explored whether ionizing radiation affects the motility activity. We performed the RING assays to evaluate the locomotor activity, a representative parameter presenting motility of fruit flies. HDR dramatically decreased the motor activity of irradiated flies. Surprisingly, the irradiated flies at low dose radiation in both acute and chronic showed the significantly increased locomotor activity, compared to non-irradiated flies. Irradiation would induce change of the several signal pathways for flies to respond to it. The activation of some proteins involved in the cells proliferation and stress

Radiation levels in Ecuadorian Cattle Milk

International Nuclear Information System (INIS)

Reinoso, Teresa; Vasquez, Ramiro

2008-01-01

Full text: The radiation and natural radioactivity present in the ground from a radioactive decay of 238 U, 235 U and 232 Th, and of the radioisotope 40 K can be transferred to the nutritional chain of the human being. Milk is a food considered basic within population's diet. The Ecuadorian Highlands has the greater production of cattle milk in the country, this industry needs great extensions of graze and available superficial water, which the cows consumed for crude milk production, with the consequent product industrialization. In the present research, gamma radiation levels where monitoring in 12 crude milk representative samples of the zone. The measurements where carried out using an equipment of spectrometry gamma ray system, with a detector of Hiperpuro Germanium (GeHp), which has been used in the analysis of standard and samples spectrums, with a constant geometry of the sample holder. The spectrums of the milk analysis show the presence of the radioisotopes coming from uranium radioactive decay. The majority of the values of activity concentration are below the minimum detection activity, unlike the potassium that presents a detectable but a non quantitative spectrum. So far, with the results obtained it is possible to guarantee the milk consumption and its derivatives in the Andean Region of the country. Related research will allow us implementing the radiological monitoring of this and other foods in the country, in order to protected population health. (author)

Low-level radiation risks in people

International Nuclear Information System (INIS)

Goloman, M.; Filjushkin, V. lgor

1993-01-01

Using the limited human data plus the relationships derived from the laboratory, a leukemia risk model has been developed as well as a suggested model for other cancers in people exposed to low levels of radiation. Theoretical experimental and epidemiological evidence will be presented in an integrated stochastic model for projection of radiation-induced cancer risks

Low-level radiation waste management system

International Nuclear Information System (INIS)

Kubofcik, K.W.

1990-01-01

This patent describes a low-level radiation waste container set for use in conjunction with an open-topped receptacle. It comprises: a receptacle liner having a closed end and an open end, the receptacle liner sized for deployment as an inserted liner in an open-topped receptacle for collecting low-level radiation waste material within the receptacle liner within the open-topped receptacle; a cover sized and shaped to fit over the open top of the open-topped receptacle and the receptacle liner therein with the cover is in a closed position. The cover having a depending skirt which, when the cover is in the closed position, extends downwardly to overlap the open-topped receptacle adjacent the open top thereof and a portion of the receptacle liner received therein; and the receptacle liner and cover being fabricated of flexible radiation shielding material

Low-level radiation: biological interactions, risks, and benefits. A bibliography

International Nuclear Information System (INIS)

1978-09-01

The bibliography contains 3294 references that were selected from the Department of Energy's data base (EDB). The subjects covered are lower-level radiation effects on man, environmental radiation, and other biological interactions of radiation that appear to be applicable to the low-level radiation problem

Molecular requirements for radiation-activated recombination

International Nuclear Information System (INIS)

Stevens, Craig W.; Zeng Ming; Stamato, Thomas; Cerniglia, George

1997-01-01

Purpose/Objective: The major stumbling block to successful gene therapy today is poor gene transfer. We hypothesized that ionizing radiation might activate cellular recombination, and so improve stable gene transfer. We further hypothesized that known DNA-damage-repair proteins might also be important in radiation-activated recombination. Materials and Methods: The effect of irradiation on stable gene transfer efficiency was determined in human (A549 and 39F) and rodent (NIH/3T3) cell lines. Continuous low dose rate and multiple radiation fractions were also tested. Nuclear extracts were made and the effect of irradiation on inter-plasmid recombination/ligation determined. Multiple DNA damage-repair deficient cell lines were tested for radiation-activated recombination. Results: A significant radiation dose-dependent improvement in stable plasmid transfection (by as much as 1300 fold) is demonstrated in neoplastic and primary cells. An improvement in transient plasmid transfection is also seen, with as much as 85% of cells transiently expressing b-galactosidase (20-50 fold improvement). Stable transfection is only improved for linearized or nicked plasmids. Cells have improved gene transfer for at least 96 hours after irradiation. Both fractionated and continuous low dose rate irradiation are effective at improving stable gene transfer in mammalian cells, thus making relatively high radiation dose delivery clinically feasible. Inter-plasmid recombination is radiation dose dependent in nuclear extract assays, and the type of overhang (3', 5' or blunt end) significantly affects recombination efficiency and the type of product. The most common end-joining activity involves filling-in of the overhang followed by blunt end ligation. Adenovirus is a linear, double stranded DNA virus. We demonstrate that adenoviral infection efficiency is increased by irradiation. The duration of transgene expression is lengthened because the virus integrates with high efficiency (∼10

Low-level radiation: biological interactions, risks, and benefits. A bibliography

Energy Technology Data Exchange (ETDEWEB)

None

1978-09-01

The bibliography contains 3294 references that were selected from the Department of Energy's data base (EDB). The subjects covered are lower-level radiation effects on man, environmental radiation, and other biological interactions of radiation that appear to be applicable to the low-level radiation problem.

Assessment of natural radioactivity levels and radiation hazards due to cement industry

International Nuclear Information System (INIS)

El-Taher, A.; Abdel Halim, A.S.

2010-01-01

The cement industry is considered as one of the basic industries that plays an important role in the national economy of developing countries. Activity concentrations of 226 Ra, 232 Th and 40 K in Assiut cement and other local cement types from different Egyptian factories has been measured by using γ-ray spectrometry. From the measured γ-ray spectra, specific activities were determined. The measured activity concentrations for these natural radionuclides were compared with the reported data for other countries. The average values obtained for 226 Ra, 232 Th and 40 K activity concentration in different types of cement are lower than the corresponding global values reported in UNSCEAR publications. The obtained results show that the averages of radiation hazard parameters for Assiut cement factory are lower than the acceptable level of 370 Bq kg -1 for radium equivalent Ra eq , 1 for level index Iγr, the external hazard index Hex ≤1 and 59 (nGy h -1 ) for absorbed dose rate. The manufacturing operation reduces the radiation hazard parameters. Cement does not pose a significant radiological hazard when used for construction of buildings.

Radiation Education Activities | RadTown USA | | US EPA

Science.gov (United States)

2018-03-12

EPA's Radiation Education Activities are designed to help increase awareness and understanding of radiation concepts among middle and high school students. The activities introduce basic concepts of radiation, non-ionizing and ionizing radiation, radiation protection, radioactive atoms and radioactive decay.

Low-level radiation: The cancer controversy

International Nuclear Information System (INIS)

Stewart, A.M.

1990-01-01

According to early studies it would be safe to assume there are no late effects of radiation apart from cancer, no lasting selective effects of the early deaths of A-bomb victims, and no cancer risk at low dose levels (below 20 rad). The nuclear establishment had good reason to believe that a potentially dangerous situation had been completely defused, and optimists were still free to regard daily exposure to background radiation as a benign influence. For several years the only indication to the contrary was the Oxford survey's finding on prenatal X-rays. But today we face the possibility that there are other late effects of radiation besides cancer; and the possibility that the selection effects of the two nuclear explosions are still reflected in death rates among survivors and are the reason why no cancer effects have been found at low dose levels. If these possibilities are confirmed, we may one day realize how fortunate it was that the Oxford survey findings put a brake on the enthusiasms of nuclear power advocates. Otherwise, we might never have pressed for direct studies of the effects of low doses of radiation. 7 refs

Radiation effects on active pixel sensors (APS)

International Nuclear Information System (INIS)

Cohen, M.; David, J.P.

1999-01-01

Active pixel sensor (APS) is a new generation of image sensors which presents several advantages relatively to charge coupled devices (CCDs) particularly for space applications (APS requires only 1 voltage to operate which reduces considerably current consumption). Irradiation was performed using 60 Co gamma radiation at room temperature and at a dose rate of 150 Gy(Si)/h. 2 types of APS have been tested: photodiode-APS and photoMOS-APS. The results show that photoMOS-APS is more sensitive to radiation effects than photodiode-APS. Important parameters of image sensors like dark currents increase sharply with dose levels. Nevertheless photodiode-APS sensitivity is one hundred time lower than photoMOS-APS sensitivity

Radiobiologic effects at low radiation levels

International Nuclear Information System (INIS)

Casarett, G.W.

1975-01-01

Data are reviewed on the effects of low radiation doses on mammals. Data from the 1972 report on the Biological Effects of Ionizing Radiation issued by the Advisory Committee of the National Academy of Sciences and National Research Council are discussed. It was concluded that there are certain radiosensitive systems in which low doses of radiation may cause degenerative effects, including gametogenic epithelium, lens of the eye, and developing embryos. Despite extensive investigation of genetic effects, including chromosomal effects, neither the amount of change that will be caused by very low levels of irradiation nor the degree of associated detriment is known

Acceptable level of radiation risk and its perception

International Nuclear Information System (INIS)

Kusama, Tomoko; Shinozaki, Motoshi; Yoshizawa, Yasuo

1987-01-01

The acceptable level of radiation risk for public members, that is 10 -5 /y, was proposed by ICRP and other international organizations. We studied to survey basic procedures of deriving this value and to derive an acceptable risk value in Japan by using similar procedures. The basic procedures to derive 10 -5 /y were found as follows; (1) 0.1 percent of annual mortality from all diseases, (2) 0.1 percent of life time risk, (3) one percent of mortality from all causes in each age cohort and (4) corresponding value to 1 mSv annual radiation exposure. From these bases we derived the value of 10 -5 /y as acceptable risk level in Japan. The perception to risk level of 10 -5 /y in conventional life was investigated by means of questionnaires for 1,095 college students living in Tokyo. The risks considered in this study were natural background radiation, coffee, skiing, X-ray diagnosis, spontaneous cancer, passive smoking and air pollution. The most acceptable risk was the risk related with natural background radiation. And the risk of natural background radiation was more easily accepted by the students who had knowledges on natural background radiation. On the other hand, the risk from air pollution or passive smoking was the most adverse one. (author)

Effects of high vs low-level radiation exposure

International Nuclear Information System (INIS)

Bond, V.P.

1983-01-01

In order to appreciate adequately the various possible effects of radiation, particularly from high-level vs low-level radiation exposure (HLRE, vs LLRE), it is necessary to understand the substantial differences between (a) exposure as used in exposure-incidence curves, which are always initially linear and without threshold, and (b) dose as used in dose-response curves, which always have a threshold, above which the function is curvilinear with increasing slope. The differences are discussed first in terms of generally familiar nonradiation situations involving dose vs exposure, and then specifically in terms of exposure to radiation, vs a dose of radiation. Examples are given of relevant biomedical findings illustrating that, while dose can be used with HLRE, it is inappropriate and misleading the LLRE where exposure is the conceptually correct measure of the amount of radiation involved

The influence of antioxidants on the disturbance of the brain activity induced by low-level ionizing radiation

International Nuclear Information System (INIS)

Godukhin, O.V.; Arkhipov, V.I.; Shipakina, T.G.; Kalemenev, S.V.; Burlakova, E.B.

1995-01-01

The effects of daily intraperitoneal injections of α-tocopherol (30 mg/kg per day) and synthetic antioxidant IHFAN-30 (30 mg/day) in rats were compared during low-level ionizing radiation (10 days, dose rate 5 mGy/h, total dose 1.2 Gy). There were analysed: (1) amplitude of population spike of hippocampal slices; (2) endogenous phosphorilation in vitro of hippocamplal synaptic proteins in the presense of cAMP; (3) formation, manifestation and reduction of food-procuring reflex. The findings showed that antioxidants made some correction of the functional state of pippocampal slices and cAMP-dependent phosphorylation system activity in brain cells from irradiated animals. No influence on training and memory functions was detected. 12 refs.; 3 figs

Development of the 'Beta-Boy' radiation counter for public acceptance activities

International Nuclear Information System (INIS)

Tanabe, Hiroshi; Kitada, Hiroshi

1993-01-01

Japan Nuclear Fuel Ltd., which was established on July 1st, 1992 largely financed by Japan's electric power companies is presently developing four projects in the village of Rokkasho, Aomori Prefecture, roughly 700 km north of Tokyo: a uranium enrichment plant, which began operation in March, 1992; a reprocessing plant to begin construction in March, 1993; a high level radioactive waste storage facility for waste returned from overseas reprocessing, construction of which began in May, 1992; and a low level radioactive waste disposal center for waste generated in nuclear power plants, which began operation in December, 1992. Approval for the location of these facilities was obtained from the authorities in Aomori Prefecture and Rokkasho Village in 1985. However, following the Chernobyl accident in 1986, the nuclear fuel cycle project in Rokkasho as well as other nuclear facilities throughout the country were faced with very active opposition from the antinuclear movement. Through our efforts to obtain public acceptance by arranging site tours, lectures, public debates and so on, we realized that many of the people of Aomori Prefecture had doubts about the nuclear fuel cycle, and that more than 80% of those people held concerns about radiation. We also found that through the demonstration of measuring atmospheric radiation levels using a large conventional portable GM survey meter of the type used in nuclear facilities, we were able to obtain considerable understanding of the nature of radiation at our lectures. Realizing therefore the need to increase this effect, we decided to develop a simple radiation counter, which all the participants at our lectures could operate themselves to measure radiation. I will now explain the characteristics of 'Beta-Boy', new radiation counter, and the method to explain radiation by using 'Beta-Boy' in our public acceptance activities

Low-level radiation effects on immune cells

International Nuclear Information System (INIS)

Makinodan, T.

1995-01-01

The purpose of this study was to characterize the effects of chronic low-dose ionizing radiation (LDR) on murine immune cells. Previously, it had been reported that LDR enhances the proliferative activity of T cells in vitro and delays the growth of transplantable immunogenic tumors in vivo. This suggests that LDR eliminates immune suppressor cells, which downregulates immune response and/or adoptively upregulates the responsiveness of immune effector cells. It had also been reported that human lymphocytes become refractive to high dose radiation-induced chromosomal aberrations by pretreating mitotically active lymphocytes in vitro with very low doses of ionizing radiation, and the adaptive effect can be abrogated by cycloheximide. This suggests that protein synthesis is required for lymphocytes to respond adoptively to LDR

Low-level radiation effects: a fact book

International Nuclear Information System (INIS)

Brill, A.B.; Adelstein, S.J.; Saenger, E.L.; Webster, E.W.

1982-01-01

Low Level Raidation Effects: A Fact Book, prepared by the Society of Nuclear Medicine Subcommittee on the Risks of Low-Level Ionizing Radiation, attempts to examine the health effects of small doses of radiation. For immediate questions, this work provides a well-organized brief summary of recent radiologic data from refereed scientific literature and from the publications of advisory groups such as the National Council of Radiation Protection and Measurement (NCRP), the International Commission on Radiological Protection (ICRP), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and the National Academy of Sciences (NAS). Since it consists almost entirely of tables and graphs from the above-mentioned sources along with summary paragraphs, the Fact Book is very useful in the preparation of lectures. The book is divided into seven sections. Chapter One, Glossary, Units and Conversion Factors, is useful because nearly all data given in the rest of the book is in conventional units and should be converted to SI units for future technical audiences. Chapter 2, Radiobiology, covers the fundamental principles of the field. Chapter 3, Radiation Doses, can be used to help an audience appreciate the relative magnitudes of radiation exposures they may read about or encounter. Chapter 4, Late Somatic Effects of Low Doses of Ionizing Radiation, gives data concerning cancer induction and embryonic effects, and Chapter 5 provides data on genetic effects Chapter 6, Risks, Statistical Facts and Public Perception can be used to compare the risks of radiation exposure with more commonly encountered risks

The research on the health effects of low-level radiation in Japan

Energy Technology Data Exchange (ETDEWEB)

Hattori, Sadao [Central Research Institute of the Electric Power Industry (Japan)

1998-07-01

Professor Don Luckey identified the phenomenon of 'radiation hormesis' and he described it in a paper in the Health Physics Society Journal, in 1982. (He also authored two books on this subject.) CRIEPI initiated a research program on radiation hormesis following this publication to confirm, 'Is it true or not?' After nearly ten years of research activities on data surveys and animal tests with many universities, we are realizing the scientific truth of bio-positive effects caused by low-level radiation exposures. The interesting bio-positive effects we found could be categorized in the following five groups: rejuvenation of cells, such as increase of SOD and cell membrane permeability; moderation of psychological stress through response of key enzymes; suppression and therapy of adult diseases, e.g., diabetes and hypertension; suppression of cancer through enhancement of immune systems, such as lymphocytes; suppression of cancer and radio-adaptive response by activation of DNA repair and apoptosis. (author)

The research on the health effects of low-level radiation in Japan

International Nuclear Information System (INIS)

Hattori, Sadao

1998-01-01

Professor Don Luckey identified the phenomenon of 'radiation hormesis' and he described it in a paper in the Health Physics Society Journal, in 1982. (He also authored two books on this subject.) CRIEPI initiated a research program on radiation hormesis following this publication to confirm, 'Is it true or not?' After nearly ten years of research activities on data surveys and animal tests with many universities, we are realizing the scientific truth of bio-positive effects caused by low-level radiation exposures. The interesting bio-positive effects we found could be categorized in the following five groups: rejuvenation of cells, such as increase of SOD and cell membrane permeability; moderation of psychological stress through response of key enzymes; suppression and therapy of adult diseases, e.g., diabetes and hypertension; suppression of cancer through enhancement of immune systems, such as lymphocytes; suppression of cancer and radio-adaptive response by activation of DNA repair and apoptosis. (author)

Multiple chromosome aberrations among newborns from high level natural radiation area and normal level natural radiation area of south west coast of Kerala

International Nuclear Information System (INIS)

Soren, D.C.; Ramachandran, E.N.; Karuppasamy, C.V.; Cheriyan, V.D.; Anil Kumar, V.; Koya, P.K.M.; Seshadri, M.

2010-01-01

Cord blood samples were collected in heparin vials and microculture techniques employed to obtain good metaphase chromosome spreads. In cytogenetic studies on newborns cells with multiple aberrations were recorded in 57 from a total of 27285 newborns (1266972 cells). Of these 17294 newborns (964140 cells) were from High Level Natural Radiation Area (HLNRA) and 9991 newborns (302832 cells) from Normal Level Natural Radiation Area (NLNRA). Cells with multiple aberrations were observed in 38 and 19 newborns from High and Normal Level Natural Radiation Area respectively. On an average one cell with multiple aberrations was observed among 479 newborns. Cells with multiple aberrations were observed in newborns from HLNRA as well as NLNRA in both males and females. Gender difference of newborns, maternal age group and background radiation levels did not seem to have any influence in the occurrence of Multiple chromosome aberrations

Regulatory control of low level radiation exposure in Tanzania

International Nuclear Information System (INIS)

Nyanda, A.M.; Muhogora, W.E.

1997-01-01

In Tanzania, the radiation protection law was issued in 1983. Under this law, the National Radiation Commission is responsible for safe uses of ionizing radiation. The regulatory control of the resulting doses from the uses of radiation sources in medicine, industry, research and teaching is presented. The system of control reflects the existing interactions between the National Radiation Commission and users through the established radiation protection infrastructure. From the national dose registry data, it is found that the highest annual individual doses over 10 years ago, came from less than 5% of total monitored workers and were in the range 10 - 15 mSv y -1 . The experienced radiation levels in uncontrolled areas of potential workplaces is less than 1 μSv h -1 . The possibility for associating such low dose levels to the effectiveness of the existing regulatory dose control framework is discussed. Despite of this achievement, the need to improve further the radiation protection and safety programs is found necessary. (author)

Energy levels, lifetimes and radiative data of W LV

Science.gov (United States)

Ding, Xiao-bin; Sun, Rui; Koike, Fumihiro; Murakami, Izumi; Kato, Daiji; Sakaue, Hiroyuki A.; Nakamura, Nobuyuki; Dong, Chen-zhong

2018-01-01

Calculations of energy levels, radiative data and lifetimes are reported for tungsten Ca-like ion (W LV) by using multi-configuration Dirac-Fock (MCDF) method. The GRASP2K package is adopted to carry out a large-scale systematic computation with a restricted active space treatment; the Breit interaction and QED effects are included in subsequent relativistic configuration interaction calculations. The energies and lifetimes of the lowest 119 levels are listed; the main leading configuration of the levels is of the ground state configuration [Ne]3s23p63d2 and the first excited configuration [Ne]3s23p53d3. The wavelengths, radiative rates and oscillator strengths for relatively strong E1, E2, M1, and M2 transitions are listed. Comparisons with earlier experimental and theoretical values are made. The average relative deviations of energy levels from the NIST results and E1 transition wavelengths from the EBIT experimental results have turned to be only 0.20% and 0.13%, respectively. The other present results are in reasonable agreement with available data. These agreements confirm the reliability and accuracy of the current results. The present datasets may help us with the investigation of the electron-electron correlation effects in complex multi-electron highly charged heavy ions and of the diagnosis of tungsten impurity plasmas in fusion science.

Intermediate bands versus levels in non-radiative recombination

International Nuclear Information System (INIS)

Luque, Antonio; Marti, Antonio; Antolin, Elisa; Tablero, Cesar

2006-01-01

There is a practical interest in developing semiconductors with levels situated within their band gap while preventing the non-radiative recombination that these levels promote. In this paper, the physical causes of this non-radiative recombination are analyzed and the increase in the density of the impurities responsible for the mid-gap levels to the point of forming bands is suggested as the means of suppressing the recombination. Simple models supporting this recommendation and helping in its quantification are presented

Acceptable level of radiation risk and its perception

Energy Technology Data Exchange (ETDEWEB)

Kusama, Tomoko; Shinozaki, Motoshi; Yoshizawa, Yasuo

1987-03-01

The acceptable level of radiation risk for public members, that is 10/sup -5//y, was proposed by ICRP and other international organizations. We studied to survey basic procedures of deriving this value and to derive an acceptable risk value in Japan by using similar procedures. The basic procedures to derive 10/sup -5//y were found as follows; (1) 0.1 percent of annual mortality from all diseases, (2) 0.1 percent of life time risk, (3) one percent of mortality from all causes in each age cohort and (4) corresponding value to 1 mSv annual radiation exposure. From these bases we derived the value of 10/sup -5//y as acceptable risk level in Japan. The perception to risk level of 10/sup -5//y in conventional life was investigated by means of questionnaires for 1,095 college students living in Tokyo. The risks considered in this study were natural background radiation, coffee, skiing, X-ray diagnosis, spontaneous cancer, passive smoking and air pollution. The most acceptable risk was the risk related with natural background radiation. And the risk of natural background radiation was more easily accepted by the students who had knowledges on natural background radiation. On the other hand, the risk from air pollution or passive smoking was the most adverse one.

Background compensation for a radiation level monitor

Science.gov (United States)

Keefe, D.J.

1975-12-01

Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

About the principles of radiation level normalization

International Nuclear Information System (INIS)

Nosovskij, A.V.

2000-01-01

The paper highlights the impact being made by the radiation level normalization principles upon the social and economic indicators. The newly introduced radiation safety standards - 97 are taken as an example. It is emphasized that it is necessary to use a sound approach while defining radiation protection standards, taking into consideration economic and social factors existing in Ukraine at the moment. Based on the concept of the natural radiation background and available results of the epidemiological surveys, the dose limits are proposed for the radiation protection standards. The paper gives a description of the dose limitation system recommended by the International Committee for Radiation Protection. The paper highlights a negative impact of the line non threshold concept, lack of special knowledge in the medical service and mass media to make decisions to protect people who suffered from the Chernobyl accident

The vitamin-like dietary supplement para-aminobenzoic acid enhances the antitumor activity of ionizing radiation

International Nuclear Information System (INIS)

Xavier, Sandhya; MacDonald, Shannon; Roth, Jennifer; Caunt, Maresa; Akalu, Abebe; Morais, Danielle; Buckley, Michael T.; Liebes, Leonard; Formenti, Silvia C.; Brooks, Peter C.

2006-01-01

Purpose: To determine whether para-aminobenzoic acid (PABA) alters the sensitivity of tumor cells to ionizing radiation in vitro and in vivo. Methods and Materials: Cellular proliferation was assessed by WST-1 assays. The effects of PABA and radiation on tumor growth were examined with chick embryo and murine models. Real-time reverse transcriptase-polymerase chain reaction and Western blotting were used to quantify p21 CIP1 and CDC25A levels. Results: Para-aminobenzoic acid enhanced (by 50%) the growth inhibitory activity of radiation on B16F10 cells, whereas it had no effect on melanocytes. Para-aminobenzoic acid enhanced (50-80%) the antitumor activity of radiation on B16F10 and 4T1 tumors in vivo. The combination of PABA and radiation therapy increased tumor apoptosis. Treatment of tumor cells with PABA increased expression of CDC25A and decreased levels of p21 CIP1 . Conclusions: Our findings suggest that PABA might represent a compound capable of enhancing the antitumor activity of ionizing radiation by a mechanism involving altered expression of proteins known to regulate cell cycle arrest

Radiation transport in high-level waste form

International Nuclear Information System (INIS)

Arakali, V.S.; Barnes, S.M.

1992-01-01

The waste form selected for vitrifying high-level nuclear waste stored in underground tanks at West Valley, NY is borosilicate glass. The maximum radiation level at the surface of a canister filled with the high-level waste form is prescribed by repository design criteria for handling and disposition of the vitrified waste. This paper presents an evaluation of the radiation transport characteristics for the vitreous waste form expected to be produced at West Valley and the resulting neutron and gamma dose rates. The maximum gamma and neutron dose rates are estimated to be less than 7500 R/h and 10 mRem/h respectively at the surface of a West Valley canister filled with borosilicate waste glass

Epidemiological studies in high-background radiation areas its potential contribution to evaluating risk of low-level radiation

International Nuclear Information System (INIS)

Akiba, Suminori; Nair, R.K.; Nakamura, Seiichi; Mizuno, Shoich

2008-01-01

The health effect of low-level ionizing radiation is yet unclear. As pointed out by Upton in his review (Upton, 1989), low-level ionizing radiation seems to have different biological effects from what high-level radiation has. Its evaluation requires epidemiological studies of scale-large cohorts (ICRP 99, 2005) such of atomic bomb survivors and nuclear workers. Epidemiological studies in high-background radiation (HBR) areas are also expected to make a significant contribution toward this end. Among several HBR areas in the world, Yangjiang, Guangdong Province in China, Karunagappally in Kerala State of India, Manawalakurichi and Koodankulam in Tamil Nadu of India, and Ramsar in Iran are important areas where epidemiological studies are possible, because of their relatively high background radiation levels and large population sizes. (author)

Variation in well-head gamma radiation levels at the Nigerian ...

African Journals Online (AJOL)

It was generally observed that the level of radiation around the well heads is less than 20x 10-12mSv/hr, which is in agreement with the International Atomic Energy Agency\\'s standard on ionizing radiation background level. Keywords: Radiation, crude oil, radionuclide, contaminant, exposure. Nigerian Journal of Physics ...

Ionizing radiation: levels and effects. Volume I. Levels

International Nuclear Information System (INIS)

1972-01-01

This is the sixth substantive report of the United Nations Scientific Committee on the Effects of Atomic Radiation to the General Assembly. It reviews the levels of radiation received from all sources to which man is exposed and, among the effects of ionizing radiation, it considers the genetic effects, the effects on the immune response and the induction of malignancies in animals and man. These are not the only effects of ionizing radiation. The acute consequences of massive amounts of radiation that may be received accidentally or during nuclear warfare are not reviewed here (the short discussion of this subject in the 1962 report is still largely valid, at least as an introduction), nor are the effects on the nervous system and the induction of chromosome anomalies in somatic cells, which were both considered by the Committee in its 1969 report. Unlike previous reports of the Committee, the present report is submitted to the General Assembly without the technical annexes in which the evidence considered by the Committee is discussed in detail and in which the bases for the Committee's conclusions, which are stated in the report, are fully documented. However, the annexes are being made available at the same time as the report in a separate publication, issued in two volumes and the Committee wishes to draw the attention of the General Assembly to the fact that the separation of the report from the annexes is for convenience only and that major importance attaches to the scientific evidence given in the annexes.

Perspectives of decision-making and estimation of risk in populations exposed to low levels of ionizing radiations

Energy Technology Data Exchange (ETDEWEB)

Fabrikant, J.I.

1979-01-01

The setting of any permissible radiation level or guide remains essentially an arbitrary procedure. Based on the radiation risk estimates derived, any lack of precision does not minimize either the need for setting public health policies nor the conclusion that such risks are extremely small when compared with those avialable of alternative options, and those normally accepted by society as the hazards of everyday life. When compared with the benefits that society has established as goals derived from the necessary activities of medical care and energy production, it is apparent that society must establish appropriate standards and seek appropriate controlling procedures which continue to assure that its needs are being met with the lowest possible risks. This implies continuing decision-making processes in which risk-benefit and cost-effectiveness assessments must be taken into account. Much of the practical information necessary for determination of radiation protection standards for public health policy is still lacking. It is now assumed that any exposure to radiaion at low levels of dose carries some risk of deleterious effects. However, how low this level may be, or the probability, or magnitude of the risk, still are not known. Radiation and the public health becomes a societal and political problem and not solely a scientific one. Our best scientific knowledge and our best scientific advice are essential for the protection of the public health, for the effective application of new technologies in medicine, and for guidance in the production of energy in industry. Unless man wishes to dispense with those activities which inevitably involve exposure to low levels of ionizing radiations, he must recognize that some degree of risk, however small, exists. In the evaluation of such risks from radiation, it is necessary to limit the radiation exposure to a level at which the risk is acceptable both to the individual and to society.

Perspectives of decision-making and estimation of risk in populations exposed to low levels of ionizing radiations

International Nuclear Information System (INIS)

Fabrikant, J.I.

1979-01-01

The setting of any permissible radiation level or guide remains essentially an arbitrary procedure. Based on the radiation risk estimates derived, any lack of precision does not minimize either the need for setting public health policies nor the conclusion that such risks are extremely small when compared with those avialable of alternative options, and those normally accepted by society as the hazards of everyday life. When compared with the benefits that society has established as goals derived from the necessary activities of medical care and energy production, it is apparent that society must establish appropriate standards and seek appropriate controlling procedures which continue to assure that its needs are being met with the lowest possible risks. This implies continuing decision-making processes in which risk-benefit and cost-effectiveness assessments must be taken into account. Much of the practical information necessary for determination of radiation protection standards for public health policy is still lacking. It is now assumed that any exposure to radiaion at low levels of dose carries some risk of deleterious effects. However, how low this level may be, or the probability, or magnitude of the risk, still are not known. Radiation and the public health becomes a societal and political problem and not solely a scientific one. Our best scientific knowledge and our best scientific advice are essential for the protection of the public health, for the effective application of new technologies in medicine, and for guidance in the production of energy in industry. Unless man wishes to dispense with those activities which inevitably involve exposure to low levels of ionizing radiations, he must recognize that some degree of risk, however small, exists. In the evaluation of such risks from radiation, it is necessary to limit the radiation exposure to a level at which the risk is acceptable both to the individual and to society

Distribution of radionuclides and radiation levels in some district of Karnataka State, India - a review

International Nuclear Information System (INIS)

Sannappa, J.

2015-01-01

Radiation is a form of energy that can be travelled through the medium in the form of waves or particles. The heat, sound and light are different forms of radiations that peoples can feel or see but there are other kinds of radiations that human senses cannot detect. Indeed we are constantly receiving such invisible radiation from the sky, earth crust, air, food and even our own body. Such radiations can be divided into ionizing and non ionizing radiation. The exposure of human beings to ionizing radiation from natural sources is a continuing and inescapable feature of life on earth. Our environment contains natural radionuclides in variable amounts. A large number of natural radioactivity measurements were conducted throughout world, in order to know their distribution and to assess their radiological health hazards. Karnataka state has 30 districts and having 74,051 sq m area and it is having various geological formations. The Archean complex made up of Dharwad schists and granitic gneisses, these cover around 60% of the area of the state and it consists of gneisses, granite and charnockite rocks. Some of the minerals found in this region are dolomite, lime stone, gabbro, quartzite, pyroxenite, manganese and iron ore and metabasalt. In addition the proposed uranium mining region is also present in Googi region of Yadagiri district. In many places Iron and manganese mining activities, crushing and quarrying activities are continuously going on. It is expected that such mining and extraction activities can enhance the natural radiation level in the environment. Hence there is a need to estimate the environmental radiation levels in the habitats of these areas. Our research group along with many researches in the Karnataka state initiated systematic study on the dose received by the population in some district of different environmental matrixes and more data are reported in Karnataka state, which have been reviewed and compiled in this paper. (author)

Radiation effects on diamine oxidase activities in intestine and plasma of the rat

International Nuclear Information System (INIS)

Ely, M.J.; Speicher, J.M.; Snyder, S.L.; Catravas, G.N.

1985-01-01

Diamine oxidase (DAO; EC 1.4.3.6) activity was measured in plasma and ileal tissue homogenates prepared from male Sprague-Dawley rats sacrificed at 1-15 days after acute whole-body irradiation with 14.5-MeV electrons. Animals irradiated with 1 Gy showed no significant changes in plasma and ileal DAO activities through day 13 relative to nonirradiated controls. Animals irradiated with 5, 10 and 12 Gy displayed marked declines in ileal DAO, with levels reaching a nadir on day 3. This was paralleled by a decrease in plasma DAO activity in all three dose groups. Recovery of ileal and plasma DAO levels was later seen as early as day 4 in animals irradiated with 5 and 10 Gy doses, but animals receiving 12 Gy did not survive beyond day 3. A further study highlights the relationship between radiation dose and levels of plasma and mucosal DAO on day 3, the time of maximum decrease at all doses tested. Mucosal DAO activity decreased almost linearly with doses up to 6 Gy. Plasma DAO levels closely paralleled the dose dependency of the mucosal levels. These data suggest that plasma DAO activity might be useful as a readily measurable marker of intestinal epithelial injury and recovery after acute radiation exposure

Environmental gamma radiation levels around various DAE research centres

International Nuclear Information System (INIS)

Takale, R.A.; Swarnakar, M.; Shetty, P.G.; Sahu, S.K.; Pandit, G.G.

2014-01-01

This paper presents the gamma radiation levels of four research centres viz. Bhabha Atomic Research Centre (BARC), Trombay; Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam; Variable Energy Cyclotron Centre (VECC), Kolkata; Raja Ramanna Centre for Advanced Technology (RRCAT), Indore; and an industry Board of Radiation and Isotope Technology (BRIT), Vashi. BARC is India's premier nuclear research facility and is a multi-disciplinary research centre with extensive infrastructure for advanced research and development (R and D). IGCAR, Kalpakkam is engaged in scientific research and advanced engineering programme towards the development of Fast Breeder Reactor technology. VECC Kolkata is dedicated to carry out frontier R and D in the fields of Accelerator Science and Technology, Nuclear Science (Theoretical and Experimental), and Material Science etc. RRCAT, Indore has rapidly grown into a premier institute for R and D in lasers, accelerators and their applications. BRIT, Vashi unit is involved in production, development, and supply of radioisotope based products and provision of isotope applications, radiation processing, radio analytical services etc. With an objective to keep a watch on the prevailing environmental background gamma radiation level around all the DAE installations, routine monitoring programme are being carried out using the Thermo Luminescent Dosimeters (TLDs). TLDs provide the simple, inexpensive and precise measurement of small, integrated, external gamma radiation dose rate. The general practice of this programme is to observe the outdoor gamma radiation levels. This paper summarizes the methodology and gamma radiation levels of four research centres viz. BARC, IGCAR, VECC, RRCAT and an industry BRIT, Vashi

Ambient radioactivity levels and radiation doses. Annual report 2011

International Nuclear Information System (INIS)

Bernhard-Stroel, Claudia; Hachenburger, Claudia; Trugenberger-Schnabel, Angela; Peter, Josef

2013-07-01

The annual report 2011 on ambient radioactivity levels and radiation doses covers the following issues: Part A: Natural environmental radioactivity, artificial radioactivity in the environment, occupational radiation exposure, radiation exposure from medical applications, the handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. Part B; Current data and their evaluation: Natural environmental radioactivity, artificial radioactivity in the environment, occupational radiation exposure, radiation exposure from medical applications, the handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. The Appendix includes Explanations of terms, radiation doses and related units, external and internal radiation exposure, stochastic and deterministic radiation effects, genetic radiation effects, induction of malignant neoplasm, risk assessment, physical units and glossary, laws, ordinances, guidelines, recommendations and other regulations concerning radiation protection, list of selected radionuclides.

Activities of Radiation Standard Section

International Nuclear Information System (INIS)

Kannan, A.; Rao, P.S.; Sachadev, R.N.; Shaha, V.V.; Sharma, D.; Srivastava, P.K.

1992-01-01

A brief account of the various facilities and services provided by the Radiation Standards Section (RSS) of the Bhabha Atomic Research Centre, Bombay is given. RSS maintains the primary and secondary standards of various parameters of radiation measurements. It ensures accurate radiological measurements as per international requirements, through periodic international intercomparisons of national standards. It also provides calibration services to various users of radiation sources and instruments. The activities of RSS are described under the headings: (1) Radiological Metrology Standards, (2) Radionuclide Standards, Neutron Metrology, (4) Instruments Calibration, (5) Non-ionizing Radiations, and (6) Instrumentation. (author). figs., tabs

Natural external radiation level and population dose in Hunan province

International Nuclear Information System (INIS)

1985-01-01

A survey of the natural external radiation level in Hunan Province is reported. The measurements were performed with FD-71 scintillation radiometers. On the basis of measurements at about 1,600 locations, the contribution from cosmic radiation is found to be 3.0 x 10 -8 Gy.h -1 , and the average absorbed dose rates in air from terrestrial γ-radiation for outdoors, indoors and roads are determined to be 9.2, 13.1 and 9.0 x 10 -8 Gy.h -1 , respectively. The γ-radiation indoors is markedly higher than that outdoors by a factor of 1.42. The lowest γ-radiation level is found in the sedimentary plain around Donting Lake, while the highest absorbed dose rates in air from terrestrial radiation are observed in some areas with exposed granites. The indoor γ-radiation in brick houses is markedly higher than that in wooden houses. Tarred roads have evidently lower radiation level than sand-gravel roads or concrete roads. The annual effective dose equivalents to the population from cosmic and terrestrial sources are 0.256 and 0.756 mSv, respectively, with a total value of 1.012 mSv

Radiation protection activities and status in Asia

International Nuclear Information System (INIS)

Strohal, P.

1993-01-01

The status of radiation protection practices in Asian countries is monitored by different means, e.g. the IAEA technical cooperation activities, by an overall assessment of conditions in a country by RAPAT missions, and on the basis of data collected through various regional activities. The radiation protection situation in Asia is very heterogeneous. There is a group of countries with very well developed radiation protection practices and advanced in the application of the Basic Safety Standards, but the majority of Asian member states still need improvement, several lacking the necessary fundamental infrastructure for radiation protection

Ramsar hot springs: how safe is to live in an environment with high level of natural radiation

International Nuclear Information System (INIS)

Mortazavi, S.M.J.

2005-01-01

Ramsar in northern Iran is among the world's well-known areas with highest levels of natural radiation. Annual exposure levels in areas with elevated levels of natural radiation in Ramsar are up to 260 mGy y -1 and average exposure rates are about 10 mGy y -1 for a population of about 2000 residents. Due to the local geology, which includes high levels of radium in rocks, soils, and groundwater, Ramsar residents are also exposed to high levels of alpha activity in the form of ingested radium and radium decay progeny as well as very high radon levels (over 1000 MBq m -3 ) in their dwellings. In some cases, the inhabitants of these areas receive doses much higher than the current ICRP-60 dose limit of 20 mSv y -1 . As the biological effects of low doses of radiation are not fully understood, the current radiation protection recommendations are based on the predictions of an assumption on the linear, no-threshold (LNT) relationship between radiation dose and the carcinogenic effects. Considering LNT, areas having such levels of natural radiation must be evacuated or at least require immediate remedial actions. Inhabitants of the high level natural radiation areas (HLNRAs) of Ramsar ar largely unaware of natural radiation, radon, or its possible health effects, and the inhabitants have not encountered any harmful effects due to living in their paternal houses. In this regard, it is often difficult to ask the inhabitants of HLNRAs of Ramsar to carry out remedical actions. Despite the fact that considering LNT and ALARA, public health in HLNRAs like Ramsar is best served by relocating the inhabitants, the residents' health seems unaffected and relocation is upsetting to the residents. Based on the findings obtained by studies on the health effect of high levels of natural radiation in Ramsar, as well as other HLNRAs, no consistent detrimental effect has been detected so far. However, more research is needed to clarify if the regulatory authorities should set limiting

Level of knowledge among the population of radiation safety basic issues

Directory of Open Access Journals (Sweden)

S. A. Zelencova

2015-01-01

Full Text Available The goal of research was to determine the level of knowledge among the population on issues like sources of ionising radiation, methods of ionising radiation measurement, measures of self-protection in case of threating or actual radioactive pollution in the district, and to study self-estimation by the population of their knowledge of radiation safety issues. Research was carried out using the method of questioning of population groups in three regions close to the places of previous peaceful nuclear explosions (Arkhangelsk, Murmansk and Tyumen regions, and in five Far East regions of the Russian Federation (Kamchatka, Khabarovsk, Primorsky, Magadan and South-Sakhalin regions after radiation accident in Japan at "Fukushima-1" NPP. This research included processing of 243 questionnaires from the regions close to places of previous peaceful nuclear explosions and 216 questionnaires from the Far East regions.The analysis of obtained questioning results enabled to make the following conclusions: the level of knowledge among the population about the basic concepts of radiation safety appeared to be generally low among respondents of all eight territories. Considerable number of respondents in seven groups correctly mentioned the x-ray device as a source of ionising radiation (from 71 to 88 % of answers. In Murmansk region – only 52 % of the answers. Respondents of the same seven groups often correctly answered the question on how to detect ionising radiation (only with devices – from 68 to 98 % in different groups. The smallest number of correct answers to this question (42 % is also noted among respondents from the Murmansk region.Level of knowledge on self-protection measures at threating or actual radioactive pollution of the places of residence appeared a little higher among the Far East region population, who had actual concerns regarding the threat of radioactive pollution at the present time. However, in all eight investigated groups

Erythrocytes antioxygant parameters in works occupationally to law levels of ionizing radiation

International Nuclear Information System (INIS)

Klucinski, P.; Martirosian, G.; Wojcik, A.; Grabowska-Bochenek, R.; Gminmski, J.; Mazur, B.; Hrycek, A.; Cieslik, P.

2008-01-01

It has been postulated that ionizing radiation generates reactive oxygen species (ROS). ROS are annihilated by an intracellular enzymatic system composed mainly of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Workers of X-ray departments are occupationally exposed to long-term low levels of ionizing radiation, which may affect their antioxidant status. Erythrocyte activities of SOD, CAT and GPx were measured in 45 workers of X-ray departments and 30 persons who constituted the control group. Subgroups with respect to sex and cigarette smoking were selected. Colorimetric method was used for determination erythrocyte activities of SOD, CAT and GPx. A significant decrease of GPx, SOD and CAT activity in workers as compared to controls was observed. Lower activity of SOD and GPx in female and GPx in male subgroup was found. SOD was significantly more elevated in smoking workers than in the non-smoking staff. Moreover non-smoking employees showed lower SOD and GPx activity in comparison to the non-smoking control. GPx decrease was found in smoking workers in comparison to the smoking control. Additionally, smoking workers showed lower activity of GPx and CAT compared to non-smoking control. (author)

Global levels of radiation exposure: Latest international findings

International Nuclear Information System (INIS)

Gonzalez, A.J.

1993-01-01

The radiation exposure of the world's population has recently been reviewed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). UNSCEAR has reconfirmed that the normal operation of all peaceful nuclear installations contributes insignificantly to the global exposure to radiation. Even taking into account all the nuclear accidents to date (including Chernobyl), the additional exposure would be equivalent to only about 20 days of natural exposure. Military uses of nuclear energy have committed the world to most of the radiation exposure caused by human activities

What happens at very low levels of radiation exposure ? Are the low dose exposures beneficial ?

International Nuclear Information System (INIS)

Deniz, Dalji

2006-01-01

Full text: Radiation is naturally present in our environment and has been since the birth of this planet. The human population is constantly exposed to low levels of natural background radiation, primarily from environmental sources, and to higher levels from occupational sources, medical therapy, and other human-mediated events. Radiation is one of the best-investigated hazardous agents. The biological effects of ionizing radiation for radiation protection consideration are grouped into two categories: The deterministic and the stochastic ones. Deterministic radiation effects can be clinically diagnosed in the exposed individual and occur when above a certain t hreshold a n appropriately high dose is absorbed in the tissues and organs to cause the death of a large number of cells and consequently to impair tissue or organ functions early after exposure. A clinically observable biological effect (Acute Radiation Sendromes, ARS) occurs days to months after an acute radiation dose. Stochastic radiation effects are the chronic effects of radiation result from relatively low exposure levels delivered over long periods of time. These are sort of effects that might result from occupational exposure, or to the background exposure levels. Such late effects might be the development of malignant (cancerous) disease and of the hereditary consequences. These effects may be observed many years after the radiation exposure. There is a latent period between the initial radiation exposure and the development of the biological effect. For this reason, a stochastic effect is called a Linear or Zero-Threshold (LNT) Dose-Response Effect. There is a stochastic correlation between the number of cases of cancers or genetic defects developed inside a population and the dose received by the population at relatively large levels of radiation. These changes in gene activation seem to be able to modify the response of cells to subsequent radiation exposure, termed the a daptive response

Effects of low levels of radiation on humans

International Nuclear Information System (INIS)

Auxier, J.A.

1981-01-01

The state of knowledge on effects of low-level ionizing radiations on humans is reviewed. Several problems relating to dose thresholds or lack of thresholds for several types of cancer and high LET radiations and the effects of fractionation and dose protection are discussed

Diffuse radiation increases global ecosystem-level water-use efficiency

Science.gov (United States)

Moffat, A. M.; Reichstein, M.; Cescatti, A.; Knohl, A.; Zaehle, S.

2012-12-01

Current environmental changes lead not only to rising atmospheric CO2 levels and air temperature but also to changes in air pollution and thus the light quality of the solar radiation reaching the land-surface. While rising CO2 levels are thought to enhance photosynthesis and closure of stomata, thus leading to relative water savings, the effect of diffuse radiation on transpiration by plants is less clear. It has been speculated that the stimulation of photosynthesis by increased levels of diffuse light may be counteracted by higher transpiration and consequently water depletion and drought stress. Ultimately, in water co-limited systems, the overall effect of diffuse radiation will depend on the sensitivity of canopy transpiration versus photosynthesis to diffuse light, i.e. whether water-use efficiency changes with relative levels of diffuse light. Our study shows that water-use efficiency increases significantly with higher fractions of diffuse light. It uses the ecosystem-atmosphere gas-exchange observations obtained with the eddy covariance method at 29 flux tower sites. In contrast to previous global studies, the analysis is based directly on measurements of diffuse radiation. Its effect on water-use efficiency was derived by analyzing the multivariate response of carbon and water fluxes to radiation and air humidity using a purely empirical approach based on artificial neural networks. We infer that per unit change of diffuse fraction the water-use efficiency increases up to 40% depending on diffuse fraction levels and ecosystem type. Hence, in regions with increasing diffuse radiation positive effects on primary production are expected even under conditions where water is co-limiting productivity.

Level of Awareness and Basic Knowledge Related to Radiation Protection Based on Academic Qualification and Service Tenure in Malaysian Nuclear Agency

International Nuclear Information System (INIS)

Munira Shaikh Nasir

2015-01-01

Effective radiation protection program is vital to ensure the safety of workers involved in work related to radiation. This objective of this research was to determine the level of awareness towards radiation protection among the workers at Malaysian Nuclear Agency. Questionnaire forms containing questions related to relevant work experience and knowledge of radiation safety were distributed to a group of identified radiation workers. The hypothesis of this study is that all workers involved have high levels of awareness and basic knowledge as they work in an institution which activities frequently and routinely involve radiation. The result of this research show that the level of awareness and knowledge of the respondents were at a good level, with an average overall score of 87.2% showed a high level of awareness among respondents. Overall, highest academic qualifications did not affect the level of knowledge (p > 0.05). In contrast, service tenure affects their level of knowledge (p < 0.05). (author)

Environmental levels of microwave radiation around a satellite earth station

International Nuclear Information System (INIS)

Joyner, K.H.; Bangay, M.J.

1986-01-01

This paper discusses the background to claims of possible adverse health effects arising from exposure to environmental levels of microwave radiation around satellite earth stations. Results of a recent survey of the environmental levels of microwave radiation around two 32 metre diameter satellite communications antennas owned and operated by the Overseas Telecommunications Commission (OTC) of Australia are presented. From the measurements obtained in this survey it can be concluded that the environmental levels of microwave radiation around the OTC and similar satellite facilities do not pose a health risk to persons in the vicinity

Activation of human immunodeficiency virus by radiation

International Nuclear Information System (INIS)

Beer, J.Z.; Zmudzka, B.Z.

1991-01-01

It was recently demonstrated that ultraviolet radiation (UVR) can induce the HIV promoter as well as activate the complete virus in cultured cells (Valerie et al., 1988). This and subsequent observations, reviewed in this article, suggest a possibility that radiation exposure may accelerate development of AIDS in HIV-infected individuals. They also indicate that studies on HIV activation by stressors, including radiation, may advance our understanding of some phenomena that follow HIV infection. (author)

Physiological benefits from low levels of ionizing radiation

International Nuclear Information System (INIS)

Luckey, T.D.

1982-01-01

Extensive literature indicates that minute doses of ionizing radiation benefit animal growth and development, fecundity, health and longevity. Specific improvements appear in neurologic function, growth rate and survival of young, wound healing, immune competence, and resistance to infection, radiation morbidity, and tumor induction and growth. Decreased mortality from these debilitating factors results in increased average life span following exposure to minute doses of ionizing radiation. The above phenomena suggest the possibility that ionizing radiation may be essential for life. Limited data with protozoa suggest that reproduction rates decrease when they are maintained in subambient radiation environments. This may be interpreted to be a radiation deficiency. Evidence must now be obtained to determine whether or not ionizing radiation is essential for growth, development, nutrient utilization, fecundity, health and longevity of higher animals. Whether or not ionizing radiation is found to be essential for these physiologic functions, the evidence reviewed indicates that the optimal amount of this ubiquitous agent is imperceptibly above ambient levels. (author)

A knowledge and awareness level survey of radiation protection among the radiation workers in Henan Province

International Nuclear Information System (INIS)

Cheng, Xiao-jun; Tian, Chong-bin; Zhang, Qin-fu; Liu, Cheng; Ding, Li

2008-01-01

Full text: Objective: To reveal the knowledge and awareness level of radiation protection among radiation workers in Henan province and to explore the methods to improve it. Methods: A questionnaire survey was carried out among 208 radiation workers. Results: The correct rate of the answer to radiation protection knowledge from radiation workers in Henan province is 53.78%. Most of them (88.9%) realized that it is important to protect patients and their companions. They adhere to the principles of justification of medial exposure and optimization of radiation protection and follow the management system of radiation protection. However, a few workers didn't follow the principles strictly. Sometime, during the radio diagnosis and radiotherapy services, the patients and their companions were not well protected from the radiation, and some patients were given unnecessary X-ray examine. Even worse, some workers did not attach importance to the regulations of radiation protection and disobey them frequently. Again, some hospital leaders disregard the regulation of radiation protection and didn't follow the regulation of health surveillance and radiation protection monitoring properly. And those behaviors and attitude, in fact, influence some workers' attitude to radiation protection. Conclusion: The level of radiation protection knowledge and awareness among the radiation workers in Henan province needs to be improved. It is necessary to strengthen radiation protection knowledge by strengthening training, and to improve safety awareness among the radiation staff, and, more important, the hospital leaders as well. (author)

Study on the biological activity of certain antihistamines subjected to radiation sterilization

International Nuclear Information System (INIS)

El-Sayed, M.E.; Roushdy, H.M.; Seham, H.H.M.

1986-01-01

The effect of gamma irradiation of pheniramine maleate and dimenhydrinate solution the dose levels 15, 25 and 50 KGY on their antihistaminic activity has been investigated using the histamine aerosol and guinea pig ileum methods. From the results obtained it could be concluded that, the antihistaminic activity of both pheniramine maleate and dimenhydrinate was not significantly changed by radiation exposure at the dose levels 15, 25 and 50 KGY. Accordingly, both of the two drugs can be safely sterilized by gamma-irradiation without encountering deleterious effect on their antihistaminic activity

Measurement uncertainty in broadband radiofrequency radiation level measurements

Directory of Open Access Journals (Sweden)

Vulević Branislav D.

2014-01-01

Full Text Available For the evaluation of measurement uncertainty in the measurement of broadband radio frequency radiation, in this paper we propose a new approach based on the experience of the authors of the paper with measurements of radiofrequency electric field levels conducted in residential areas of Belgrade and over 35 municipalities in Serbia. The main objective of the paper is to present practical solutions in the evaluation of broadband measurement uncertainty for the in-situ RF radiation levels. [Projekat Ministarstva nauke Republike Srbije, br. III43009

Regional and national radiation protection activities in Egypt

International Nuclear Information System (INIS)

Gomaa, M.A.M.

2008-01-01

Radiation protection activities in Egypt go back to 1957 where the Egyptian Atomic Energy Commission (EAEC) Law was issued. Radiation protection and civil defense department was one of EAEC eighth departments. Ionizing radiation law was issued in 1960 and its executive regulation in 1962. The main aim of the present work is to through some light on the current radiation protection activities in Egypt. This includes not only the role of governmental organizations but also to the non governmental organizations. Currently a new Nuclear Safety law is understudy. Regional activities such as holding the second all African IRPA regional radiation protection congress which was held in April 2007 and national training and workshops are held regularly through EAEA, AAEA and MERRCAC. (author)

The analysis of radiation levels for daily supplies made in Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, H.R. [Ulsan National Inst. of Science and Tech., Ulsan (Korea, Republic of)

2014-07-01

The radiation levels were measured and assessed for samples around a living environment such as building materials and industrial products for which civil complaint had been filed to have radioactivity in Korea. The dose rates for more than one hundred samples from the goods in a living environment were compared with those of the background. The sample's radiation level ranged from 0.095 μSv/h to 0.162 μSv/h, which are within the range of the laboratory background level from 0.090 μSv/h to 0.174 μSv/h. It was thought the radiation level of the goods for which the civil complaint was given had not particular difference from the environmental radiation level in Korea in spite of deviations for some samples. (author)

Biological monitors for low levels of ionising radiation

International Nuclear Information System (INIS)

Mohankumar, M.N.; Jeevanram, R.K.

1995-01-01

The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author)

Activity concentrations of K, Th, Ra and radiation exposure levels in ...

African Journals Online (AJOL)

use

Available online at http://www.academicjournals.org/AJEST ... average absorbed dose rate for the five quarries was found to be 541.4 nGyh-1 1m above the ground level while .... conversion factors for converting the activity concentrations of.

Biological effects of low-level ionizing and non-ionizing radiation

International Nuclear Information System (INIS)

Upton, A.C.

1986-01-01

Early in this century it was recognized that large doses of ionizing radiation could injure almost any tissue in the body, but small doses were generally thought to be harmless. By the middle of the century however it came to be suspected that even the smallest doses of ionizing radiation to the gonads might increase the risk of hereditary disease in subsequently-conceived offspring. Since then the hypothesis that carcinogenic and teratogenic effects also have no threshold has been adopted for purposes of radiological protection. It is estimated nevertheless that the risks that may be associated with natural background levels of ionizing irradiation are too small to be detectable. Hence validation of such risk estimates will depend on further elucidation of the dose-effect relationships and mechanisms of the effects in question, through studies at higher dose levels. In contrast to the situation with ionizing radiation, exposure to natural background levels of ultraviolet radiation has been implicated definitively in the etiology of skin cancers in fair-skinned individuals. Persons with inherited effects in DNA repair capacity are particularly susceptible. Non-ionizing radiations of other types can also affect health at high dose levels, but whether they can cause injury at low levels of exposure is not known

Acute radiation effects on the content and release of plasminogen activator activity in cultured aortic endothelial cells

International Nuclear Information System (INIS)

Ts'ao, C.H.; Ward, W.F.

1985-01-01

Confluent monolayers from three lines of bovine aortic endothelial cells were exposed to a single dose of 10 Gy of 60 Co γ rays. Seventy-two hours later, the morphology of the irradiated and sham-irradiated monolayers was examined, and cellular DNA and protein contents were determined. In addition, the release of plasminogen activator (PA) activity into the culture media and PA activity in the cell lysates were assayed. DNA and protein contents in the irradiated monolayers were reduced to 43-50% and 72-95% of the control levels, respectively. These data indicate that radiation induced cell loss (detachment and/or lysis) from the monolayer, with hypertrophy of surviving (attached) cells to preserve the continuity of the monolayer surface. Total PA activity (lysate plus medium) in the irradiated dishes was reduced to 50-75% of the control level. However, when endothelial PA activity was expressed on the basis of DNA content, the irradiated monolayers from two of the three cell lines contained significantly more PA activity than did sham-irradiated monolayers. These data suggest that fibrinolytic defects observed in irradiated tissues in situ may be attributable at least in part to a radiation-induced inhibition of PA release by vascular endothelial cells

Environmental radiation levels in and around Kalpakkam during 1983-1987

International Nuclear Information System (INIS)

Nambi, K.S.V.; Mehta, N.K.; Sundaram, Meenakshi; Viswambharan, K.R.

1989-01-01

Results of the environmental radiation monitoring around the Kalpakkam Atomic Power Station carried out routinely on quarterly integrating cycles using thermoluminescent dosimeters, are presented and analysed, for the five year period 1983-87. As the first reactor attained criticality in July 1983 and the second unit in August 1985 the results are compared with the previously published values for the period 1980-82. Only at two locations viz. the Micro-met laboratory situated at 800 meters from the station and the main gate located at the 1.6 km exclusion zone boundary, a possible indication of increases in the environmental radiation level associated with the power reactor operations could be discerned. However these were found to be statistically insignificant. The whole terrain is characterised by somewhat high levels of terrestrial radiations with quite wide temporal fluctuations which easily mask the small increases if any in the radiation levels, contributed by the reactors. Places located farther away from the power station and away from the monazite-bearing beaches, yielded an annual average background level of 117 ± 29 mR as against the value of 125 ± 24 mR obtained during the preoperational period of 1980-82. A declining general trend in the radiation levels is seen at many locations and this is thought to be associated with significant reduction in the 137 Cs fallout component of the environmental radiation. (author). 5 refs., 2 tabs., 11 figs

Radiation levels in nuclear diagnostic examinations

International Nuclear Information System (INIS)

Vermeulen, A.M.T.I.

1987-01-01

To estimate the risks for a pregnant radiological worker, radiation level measurements are executed for common nuclear diagnostic techniques. These measurements are combined with the time which the radiologic worker is present during the performance of the diagnostic techniques. It is concluded that a radiologic worker is receiving less than 5 mSv during pregnancy. This is the case with in vivo determination in a department of nuclear medicine with common diagnostic techniques. Reduction of radiation doses during pregnancy is possible by reduction of heart function examinations, skeletal examinations and brain scans. 1 figure; 13 tabs

Somatic and genetic effects of low-level radiation

International Nuclear Information System (INIS)

Upton, A.C.

1974-01-01

Although the biological effects of ionizing radiation are probably better known than those of any other physical or chemical agent in the environment, our information about such effects has come from observations at doses and dose rates which are orders of magnitude higher than natural background environmental radiation levels. Whether, therefore biological effects occur in response to such low levels can be estimated only by extrapolation, based on assumptions about the dose-effect relationship and the mechanisms of the effects in question. Present knowledge suggests the possibility that several types of biological effects may result from low-level irradiation. The induction of heritable genetic changes in germ cells and carcinogenic changes in somatic cells are considered to be the most important from the standpoint of their potential threat to health. On the basis of existing data, it is possible to make only tentative upper limit estimates of the risks of these effects at low doses. The estimates imply that the frequency of such effects attributable to exposure at natural background radiation levels would constitute only a small fraction of their natural incidence. 148 references

Radioprotective effect of sesamol on γ-radiation induced DNA damage, lipid peroxidation and antioxidants levels in cultured human lymphocytes

International Nuclear Information System (INIS)

Prasad, N. Rajendra; Menon, Venugopal P.; Vasudev, V.; Pugalendi, K.V.

2005-01-01

Sesamol pretreated (1, 5 and 10 μg/ml) lymphocytes were exposed to different doses of γ-radiation, i.e., 1, 2 and 4 Gray (Gy) and the cellular changes were estimated by using cytokinesis blocked micronucleus assay (MN), dicentric aberration (DC), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Radiation significantly increased MN, DC frequencies, TBARS levels and decreased GSH and antioxidant enzyme levels in a dose dependent manner. The highest damage to lymphocytes was observed at 4 Gy irradiation. On the other hand, sesamol pretreatment significantly decreased MN, DC frequencies, TBARS levels and increased GSH levels and SOD, CAT and GPx activities in a concentration dependent manner. At 1 Gy irradiation all concentrations of sesamol (1, 5 and 10 μg/ml) significantly protects the lymphocytes from radiation damage. At 2 Gy irradiation 5 and 10 μg/ml of sesamol shows significant radioprotection. Since the highest damage was observed at 4 Gy irradiation both 1 and 5 μg/ml of sesamol pretreatment were not sufficient to protect the lymphocytes from radiation damage but 10 μg/ml of sesamol significantly (p < 0.05) protects the lymphocytes from radiation effect. Thus, sesamol pretreatment gives significant protection to cultured human lymphocytes against γ-radiation induced cellular damage. The possible mechanism involved in the radioprotective influence of sesamol is discussed

General discussion about enzymes activities of radiation injury

International Nuclear Information System (INIS)

Vucicevic, M.; Sukalo, I.

1989-01-01

Researching reliable and practical indicators of radiation injury, however, is very interesting and considerable department of scientific studies, practical and theoretical. Enzymes activities are among biochemical indicators which are changed after radiation injury. Activity of these specific proteins is important in regulation of every biochemical reaction in existing beings. Biological macromolecules can be damaged by radiation or the cell permeability can be changed. All of these influence directly on enzymes activities. In this paper we present the review of the all important enzymes, indicators of the radiation injury, which variances on reference to normal values are significant of the functional and the structural changes of essential organs (author)

General discussion about enzymes activities of radiation injury

Energy Technology Data Exchange (ETDEWEB)

Vucicevic, M; Sukalo, I [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

1989-07-01

Researching reliable and practical indicators of radiation injury, however, is very interesting and considerable department of scientific studies, practical and theoretical. Enzymes activities are among biochemical indicators which are changed after radiation injury. Activity of these specific proteins is important in regulation of every biochemical reaction in existing beings. Biological macromolecules can be damaged by radiation or the cell permeability can be changed. All of these influence directly on enzymes activities. In this paper we present the review of the all important enzymes, indicators of the radiation injury, which variances on reference to normal values are significant of the functional and the structural changes of essential organs (author)

Risks of low-level radiation - the evidence of epidemiology

International Nuclear Information System (INIS)

Gloag, D.

1980-01-01

The difficulties involved in estimating risks from very low levels of radiation and the use of dose-response models for cancer incidence are discussed with reference to the third BEIR Committee report on the Effects on Populations of Exposure to low levels of Ionizing Radiation (1980). Cancer risk estimates derived from different epidemiological studies are reviewed. They include atom bomb survivors, medically irradiated groups and occupational groups. (36 references). (author)

Workplaces with elevated levels of exposure to natural radiation: The situation in Sweden

International Nuclear Information System (INIS)

Mjoenes, L.; Aakerblom, G.

2002-01-01

Because of the geological conditions with an abundance of granites and pegmatites rich in uranium and thorium together with large areas of uranium-rich alum shale, exposure from natural radiation is not unusual in certain types of industries and other work activities in Sweden. Although no representative survey of radon at regular workplaces has been performed in Sweden, smaller surveys and the high radon concentrations in dwellings indicate that workplaces with elevated radon levels are frequent in Sweden. Very high levels of indoor radon have been found in waterworks. Radon in mines has been regulated in Sweden since 1972 and radon in other workplaces since 1990. The situation in schools and day-care centres was thoroughly investigated in 2000. The estimated number of school and child care buildings with radon concentrations exceeding the action level 400 Bq/m 3 , is 800, about 200 of these have been identified and in about 100 buildings remedial measures have been taken. Regulations for natural radioactivity in building materials (for new buildings) have been in force since 1980. Lightweight concrete produced from uranium-rich alum shale was in use between 1929 and 1975. Almost 400,000 dwellings, 10 percent of the building stock, contain this material. The situation at NORM (Naturally Occurring Radioactive Material) industries is currently being investigated. Since the beginning of the 1950s it is known that residues from several industrial activities contain enhanced levels of natural radioactivity. Some examples are burnt alum shale from lime burning, radium-rich slag from metal production and waste gypsum from sulphuric acid production. The impact of the exposure from these residues is now being reinvestigated. So far no systematic search for up to now unknown work activities where substantial exposures from natural radiation could occur, has been initiated. For the protection of aircrew from cosmic radiation the responsible Swedish authorities have

Human exposure to low level ionising radiation

International Nuclear Information System (INIS)

Paix, David

1988-01-01

This paper describes the low-level radiation sources and their effects on human populations, from a global perspective. 'Low-level' means exposures in the range of the natural background to which everybody is exposed. The quoted values are whole-world averages, but individual variations are mentioned in a few cases. (author). 22 refs

Evaluating natural radiation level by existing airborne radioactive data

International Nuclear Information System (INIS)

Mingkao, Hu; Changqing, Han; Jiangqi, Fang; Zhengxin, Shen

2002-01-01

Airborne Survey and Remote Sensing Center of Nuclear Industry, founded in the middle of 1950s, is a unique unit specialized in uranium exploration by airborne radioactive survey in China. Large numbers of airborne data of radioactivity and abundant experience have been accumulated for more than 40 years. All-round detailed investigation of environmental radiation levels in our country will not be completed in the near future. Thus, at present it is considered to evaluate natural radiation levels using the existing radioactive data. This paper introduces the results of analysis and study comparing airborne radioactive data for radiation environmental evaluation obtained from survey area in Gansu, China, in the 2001 with the measurement results by ground gamma ray radiation dose-rate instrument for environment. The air-earth inter-comparison error does not exceed 30% at radiation fields with a definite area, and the air-earth inter-comparison error does not exceed 60% at outcrop of granite. In 6km long profile that has various circumstances, such as desert, Gobi, farmland and residential area, minimum of air absorbed dose rate is 47nGy/h at an altitude of 1 meter above the soil plane, maximum is 68nGy/h. The inter-comparison errors are usually less than 20%, and maximum is 25.38%. This shows that it is feasible to obtain natural radiation levels rapidly if we could use the existing radioactive data adequately and make some correction, such as geology factor

Review of the controversy on risks from low levels of radiation

International Nuclear Information System (INIS)

Higson, D.

2001-01-01

The need for regulation of low levels of radiation exposure, and the estimation of risks from such exposures, are based on the assumption that risk is proportional to dose without a threshold, the 'linear no-threshold (LNT) hypothesis'. This assumption is not supported by scientific data. There is no clear evidence of harm from low levels of exposure, up to at least 20 mSv (acute dose) or total dose rates of at least 50 mSv per year. Even allowing for reasonable extrapolation from radiation levels at which harmful effects have been observed, the LNT assumption should not be used to estimate risks from doses less than 100 mSv. Laboratory and epidemiological evidence, and evolutionary expectations of biological effects from low level radiation, suggest that beneficial health effects (sometimes called 'radiation hormesis') are at least as likely as harmful effects from such exposures. Controversy on this matter strikes at the basis of radiation protection practice

Cosmic radiation doses at flight level altitudes of airliners

International Nuclear Information System (INIS)

Viragh, E.; Petr, I.

1985-01-01

Changes are discussed in flux density of cosmic radiation particles with time as are the origin of cosmic radiation, the level of cosmic radiation near the Earth's surface, and the determination of cosmic radiation doses in airliners. Doses and dose rates are given measured on different flight routes. In spite of the fact that the flight duration at an altitude of about 10 km makes for about 80% of the total flight time, the overall radiation burden of the crews at 1000 flight hours a year is roughly double that of the rest of the population. (J.C.)

Biological monitors for low levels of ionising radiation

Energy Technology Data Exchange (ETDEWEB)

Mohankumar, M N; Jeevanram, R K [Safety Research and Health Physics Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

1996-12-31

The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author). 98 refs., 11 figs., 4 tabs.

Quality control of radiation counting systems and measurement of minimum detectable activity

International Nuclear Information System (INIS)

Song, Byoung Chul; Han, Sung Sim; Kim, Young Bok; Jee, Kwang Yong; Sohn, Se Chul

2004-01-01

Various radiation counters have been using to determine radioactivity of radwastes for disposal. A radiation counting system was set up using a radiation detector chosen in this study and its stability was investigated through the periodic determination of background and counting efficiencies in accordance with a quality control program to increase the confidence level. The average background level for the γ-spectrometer was 1.59 cps and the average counting level for the standard sample was 45248 dps within 20 confidence levels. The average alpha background level for the low background α/β counting system was 0.31 cpm and the efficiency for alpha counting was 34.38 %. The average beta background level for the α/β counting system was 1.30 cpm and the efficiency for beta counting was 46.5%. The background level in the region of 3H and 14C for the liquid scintillation counting system was 2.52 and 3.31 cpm and the efficiency for alpha counting was 58.5 and 95.6%, respectively. The minimum detectable activity for the γ-spectrometer was found to be 3.2 Bq/mL and 3.8 Bq/mL for the liquid scintillation counter, and 20.5 and 23.0 Bq/mL, respectively for the α and β counting system

Low-level radiation and cancer deaths

International Nuclear Information System (INIS)

Sanders, B.S.

1978-01-01

It is stated that although the proportion of cancer deaths among males is somewhat higher for Hanford employees with recorded occupational radiation exposure compared with males in the general population of the State of Washington, there is no indication that radiation is the cause of this difference. Statistics are given for mean doses received and for deaths from cancer and other causes for male employees. It is shown that for each year the mean dose level of those who died from cancer is not significantly different from the mean of those who died from other causes. The mean dose level for the majority of those who died in a specific year is lower than the mean for the survivors in the year of death, in the year preceding the year of death, or in the two years preceding the year of death. This is true whether the mean was for those dying from cancer or from other causes. These relationships are similar for female exposed employees and agree with other similar studies. The latest analysis on longevity of exposed male Hanford employees vs those nonexposed and the out-of-plant controls from date of hire to April 1974 are considered and show no firm indication of any lasting adverse health effects among employees attributable to occupational exposure to radiation within permissible limits. (U.K.)

Gamma radiation induced enhancement in the antioxidant and radioprotective activities of flavonoids

International Nuclear Information System (INIS)

Arul Anantha Kumar, A.; Sonwani, Swetha; Bakkiam, D.

2018-01-01

Recently γ-radiation has been used as a tool to induce structural changes in natural biomolecules to enhance their biological and physiological properties. Flavonoids are a family of plant derived polyphenolic compounds having considerable scientific and therapeutic importance. Structurally they are the benzo-γ-pyrone derivatives containing phenolic and pyrane rings. Flavonoid radioprotection is an intense area of research thanks to features like natural origin, effectiveness at non-toxic dose levels and lack of side effects. But till date no report is available on the effect of γ-radiation mediated enhancement in radioprotection activity of flavonoids. In view of this the present study was carried out to determine the γ-radiation induced structural changes in selected flavonoids i.e. apigenin, naringenin and genistein and also to explore the possibility of enhancement in their antioxidant and radioprotective activities

Legislation and litigation related to low-level radiation injury claims

International Nuclear Information System (INIS)

McCraw, T.

1985-01-01

Current legislation and litigation related to radiation exposure will have an enormous impact on the radiation protection and monitoring requirements of the future. A brief review of some proposed injury compensation bills for veterans and a recent court decision for low-level radiation injury claims are reviewed

Investigation of environmental natural penetrating radiation level in inner mongolia

International Nuclear Information System (INIS)

Li Wenyuan; Du Xuelin; Zhang Baozhong; Fu Su; Chen Jun; Zhang Wenhai

1990-01-01

The scheme, quality assurance measure, and results for environmental natural penetrating radiation level investigation in Inner Mongolia Autonomous Region was reported. Over the whole Region area of more than 1.18 million km 2 , 1018 net grid measuring points were selected with grid spacing of 25 x 25 km. The range of natural environmental terrestrial γ-radiation air absorbed dose rate over fields was (0.96-18.62) x 10 -8 Gy·h -1 , the range of γ-radiatoin dose rate over road was (1.07-26.08) x 10 -8 Gy·h -1 , the mean was 5.92 x 10 -8 Gy·h -1 ; the range of γ-radiation dose rate in buildings was (3.82-18.94) x 10 -8 Gy·h -1 ; the range of outdoor air absorbed dose rate caused by ionization compnents of cosmic rays was (3.12-5.55) x 10 -8 Gy·h -1 , while indoor range was (2.60-4.66) x 10 -8 Gy·h -1 ; the range of outdoor natural penetrating radiation dose rate was (8.31-11.26) x 10 -8 Gy·h -1 , indoor range was (11.20-14.67) x 10 -8 Gy·h -1 ; annual average individual effective dose equivalent and annual collective effective dose equivalent caused by natural penetrating radiatoin were 0.84 mSv and 1.61 x 10 4 man·Sv respectively. The georgaphical distribution of terrestrial γ-radiation dose rate within all region was reprted, the increase of environmental terrestial γ-radiation caused by human activity was also pointed. This ought to be paid enough attention to

The Radiation Levels for Household Goods Made in Korea

International Nuclear Information System (INIS)

Kim, Hee Reyoung; Park, Doo Won; Lee, Wan No; Choi, Sang Do; Chung, Kun Ho; Kang, Mun Ja; Choi, Geun Sik; Lee, Chang Woo

2008-01-01

The environmental radiation based on a natural and artificial radiation always exists in the environment. The natural radiation includes cosmic ray coming into the atmosphere from outer space, radiation emitted from the earth's crust or soil, radiation by the radon in the air and its progenies. These natural radiation comes from various buildings like a house and an apartment, agricultural and stock breeding products like rice and milk, and a body, etc. The artificial radiation emanates from a nuclear power plant, a radioisotope facility, a radioactive waste disposal site, a medical or research facility treating a radioactive material, a radiation generation device for an industry, TV, a microwave oven, appliances like a fluorescent clock, an airport security table, etc. Among the various kinds of radioactive nuclides that existed in the earth's crust at the time of the earth's formation about 4,000 million years ago, all the short half life nuclides decayed and the long half life nuclides remain amid the nuclides of a half life with more than 100 million years and their progenies now. In fact, the natural radiation level is determined by the nuclides of the Thorium series which have K-40 (half life 1.25 billion years), Th-232 (half life 14.5 billion years) as a parent nuclide, the nuclides of the uranium series which have U-238 (half life 4.5 billon years) as a parent nuclide, and the cosmic ray like photon and muon. These nuclides are distributed in the soil, sea water, construction material and body with different concentrations. Different radiation dose rates are presented in different regions due to the different concentrations of the radioactive minerals included at the materials. Actually, Brazil and India reveal a relatively high natural radiation level

Report on radiation protection calibration activities in Australia

International Nuclear Information System (INIS)

Hargrave, N.J.

1995-01-01

Australia is a federation of eight autonomous States or Territories. Each of these is responsible for many matters including radiation safety within their borders. National matters are the responsibility of the Federal Government. The Australian Radiation Laboratory (ARL) is a part of the Federal Government Department of Human Services and Health and undertakes research and service activities related to radiation health. Work related to both ionising and non ionising radiation and regulatory matters is performed. Some of the research activities relate to radiation measurement standards, environmental radioactivity (e.g. radon in air, radioactivity in drinking water), effects of electro-magnetic fields on health (ELF), ultra violet radiation (UV) and laser safety, radiochemistry, medical applications of radiation (and doses to the population as a result), general health physics, thermoluminescent dosimetry (TLD) and electron spin resonance (ESR) dosimetry. The calibration of protection instruments are undertaken by the Ionising Radiation Standards Group within the Laboratory and by State Health Laboratories. (J.P.N.)

Studies on the natural radiation levels around the Caspian sea area

International Nuclear Information System (INIS)

Akbari, R.B.

1993-01-01

We measured about 80 items from four areas of Mazandaran, randomly selected samples of food products, soil and water, around the shore of the Caspian sea area. The results showed that the natural radioactivity in beans and broad beans in some areas is much more than in others. The results were also compared with the levels of radiations from some materials from Brazil, which also contained high levels of radiations. Samples measured in this study showed higher levels of radiations than the American food products. (author). 12 refs, 8 tabs

The Level of Europium-154 Contaminating Samarium-153-EDTMP Activates the Radiation Alarm System at the US Homeland Security Checkpoints

Directory of Open Access Journals (Sweden)

Mohammed Najeeb Al Hallak

2009-08-01

Full Text Available 153Sm-EDTMP is a radiopharmaceutical composed of EDTMP (ethylenediamine-tetramethylenephosphonate and Samarium-153 [1]. 153Sm-EDTMP has an affinity for skeletal tissue and concentrates in areas with increased bone turnover; thus, it is successfully used in relieving pain related to diffuse bone metastases [1]. The manufacturing process of 153Sm-EDTMP leads to contamination with 154Eu (Europium-154 [2]. A previous study only alluded to the retention of 154Eu in the bones after receiving treatment with 153Sm-EDTMP [2]. Activation of the alarm at security checkpoints after 153Sm-EDTMP therapy has not been previously reported. Two out of 15 patients who received 153Sm-EDTMP at Roger Maris Cancer Center (Fargo, N. Dak., USA activated the radiation activity sensors while passing through checkpoints; one at a US airport and the other while crossing theAmerican-Canadian border. We assume that the 154Eu which remained in the patients’ bones activated the sensors. Methods: In order to investigate this hypothesis, we obtained the consent from 3 of our 15 patients who received 153Sm-EDTMP within the previous 4 months to 2 years, including the patient who had activated the radiation alarm at the airport. The patients were scanned with a handheld detector and a gamma camera for energies from 511 keV to 1.3 MeV. Results: All three patients exhibited identical spectral images, and further analysis showed that the observed spectra are the result of 154Eu emissions. Conclusion: Depending on the detection thresholds and windows used by local and federal authorities, the remaining activity of 154Eu retained in patients who received 153Sm-EDTMP could be sufficient enough to increase the count rates above background levels and activate the sensors. At Roger Maris Cancer Center, patients are now informed of the potential consequences of 153Sm-EDTMP therapy prior to initiating treatment. In addition, patients treated with 153Sm-EDTMP at Roger Maris Cancer Center

Safety and radiation protection aspects of the management of radioactive wastes of high level activity

International Nuclear Information System (INIS)

Candes, P.; Pradel, J.

1977-01-01

Appropriate consideration is given in France to safety and protection problems to be solved from the production up to the final disposal of radioactive wastes of high level activity. The first stage of the work consisted in emphasizing the various technical options. Different strategies appear to be possible, taking into account technical, political, and psychological difficulties. This results in evaluating the safety problems to be solved in the framework of those strategies. In this field, the main safety and protection principles do not differ from those which apply to other nuclear facilities. Nevertheless, duration is in most cases a quite different factor (thousands or millions of years). The question is then raised of evaluating the importance to be given to very remote consequences, both at philosophical and scientific levels. As a first result of those considerations, the application of the ''barrier'' concept is recommended. This concept is familiar to safety specialists. Different barriers for which particular problems are listed and evaluated, are defined. Another results with regard to radiation protection principles is to consider that if safety provisions should lead to a containment of radioactive products as efficient as possible, it would not be realistic to consider such a containment as absolute, in particular for disposal durations arising to thousands of years. It is therefore assumed that a limited radioactivity transfer should be taken into account, and its consequences for environment and man be calculated. This is especially true in the study of an appropriate site for final storage, and the study should necessarily include a detailed investigation of the retention characteristics of soil layers, and the implementation of appropriate models giving a sufficiently accurate evaluation of the consequences of transfers, including those related to the effect of various elements after their arrival into the biosphere. The authors review the

Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization

Energy Technology Data Exchange (ETDEWEB)

Meng, Zhen [Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Gan, Ye-Hua, E-mail: kqyehuagan@bjmu.edu.cn [Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China)

2015-05-01

Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation. - Highlights: • COX-2 inhibitor, celecoxib, could enhance radiosensitization. • Radiation induced PTEN inactivation (phosphorylation) and AKT activation. • COX-2 inhibitor induced PTEN expression and activation, and inactivated AKT. • COX-2 inhibitor enhanced radiosensitization through activating PTEN.

Level of Radiofrequency (RF) Radiations from GSM Base Stations ...

African Journals Online (AJOL)

Levels of radiofrequency radiations around two global systems for mobile communication (GSM) base stations located in the vicinity of a residential quarter and workplace complex were measured. The effects of the radiofrequency radiations on albino mice placed in exposure cages and located around the base stations ...

Investigation of the relationship between knowledge concerning radiation and the level of anxiety toward radiation in student nurses

International Nuclear Information System (INIS)

Kunugita, Naoki

2008-01-01

In the medical fields, the use of radiation is indispensable in diagnosis, radiotherapy, nuclear medicine and various other areas. On the other hand, great anxiety is often felt due to the misunderstanding of radiation, and this anxiety is seen in not only patients but also nurses. In this study, a questionnaire survey about knowledge of radiation and the level of anxiety was carried out in student nurses for three years from 2005 to 2007. The questionnaire included the level of anxiety about radiation and 12 basic question items concerning radiation. The results showed that the student with poor knowledge about radiation showed high anxiety. After a series of lectures concerning radiation, the acquisition of knowledge and a decrease in anxiety were observed in the students. However, it was still shown that people with scarce knowledge concerning radiation still had high anxiety at the end of the lectures. In conclusion, it was shown that education about radiation is necessary to decrease anxiety about radiation among nurses in medical care. (author)

Evaluation of the activity levels in fusion reactor blankets

International Nuclear Information System (INIS)

Gruber, J.

1977-05-01

The activation of a fusion reactor blanket (316 SS or V-10Cr-10Ti as structure) with a minimum lithium inventory has been calculated for 0.83 MW/m 2 wall load. The resulting radiation levels and waste problems are discussed. The dose rate near the steel structure will always be higher than 0.1 rem/h due to its niobium content. After 200 to 100,000 years of decay the potential biological hazard originating from this high level fusion reactor waste (with plutonium recyclation). (orig.) [de

Frequency-independent radiation modes of interior sound radiation: Experimental study and global active control

Science.gov (United States)

Hesse, C.; Papantoni, V.; Algermissen, S.; Monner, H. P.

2017-08-01

Active control of structural sound radiation is a promising technique to overcome the poor passive acoustic isolation performance of lightweight structures in the low-frequency region. Active structural acoustic control commonly aims at the suppression of the far-field radiated sound power. This paper is concerned with the active control of sound radiation into acoustic enclosures. Experimental results of a coupled rectangular plate-fluid system under stochastic excitation are presented. The amplitudes of the frequency-independent interior radiation modes are determined in real-time using a set of structural vibration sensors, for the purpose of estimating their contribution to the acoustic potential energy in the enclosure. This approach is validated by acoustic measurements inside the cavity. Utilizing a feedback control approach, a broadband reduction of the global acoustic response inside the enclosure is achieved.

Level Densities and Radiative Strength Functions in 170,171Yb

International Nuclear Information System (INIS)

Agvaanluvsan, U.; Schiller, A.; Becker, J.A.; Berstein, L.A.; Guttormsen, M.; Mitchell, G.E.; Rekstad, J.; Siem, S.; Voinov, A.

2003-01-01

Level densities and radiative strength functions in 171 Yb and 170 Yb nuclei have been measured with the 171 Yb( 3 He, 3 He(prime) γ) 171 Yb and 171 Yb( 3 He, αγ) 170 Yb reactions. A simultaneous determination of the nuclear level density and the radiative strength function was made. The present data adds to and is consistent with previous results for several other rare earth nuclei. The method will be briefly reviewed and the result from the analysis will be presented. The radiative strength function for 171 Yb is compared to previously published work.

Terrestrial radiation level in selected asphalt plants in Port Harcourt ...

African Journals Online (AJOL)

Terrestrial radiation level in selected asphalt plants in Port Harcourt, Nigeria. ... An environmental radiation survey in asphalt processing plants in Rivers State was been carried out ... Therefore the results show significant radiological risk.

Epidemiological studies in the high and normal level radiation areas of Kerala

International Nuclear Information System (INIS)

Koya, P.K.M.

2012-01-01

High and normal level natural radiation areas of Kerala give unique opportunities to estimate the risk, if any, of chronic low dose exposure by direct epidemiological studies on human beings. Studies in the area are being carried out by Low Level Radiation Research Laboratory of Bhabha Atomic Research Centre in collaboration with Departments of Health and Family Welfare/Social Welfare of the Government of Kerala and local post graduate colleges. To assess the role of chronic low dose exposure in the induction/transmission of chromosomal alterations across generations, hospital based cytogenetic studies on newborns was carried out to estimate and compare the frequency of chromosomal aberrations and karyotypes anomalies in the high (areas with radiation dose of more than 1.50 mGy/year) and normal (areas with radiation dose of 1.50 mR/year or less) level radiation areas. A total of 1,267,788 metaphases from 27,295 (9,64,390 cells from 17,298 newborns of high and 3,03,398 cells from 9,997 newborns of normal level radiation areas) newborns was screened

Effects of radiation and α-tocopherol on saliva flow rate, amylase activity, total protein and electrolyte levels in oral cavity cancer

Directory of Open Access Journals (Sweden)

Chitra S

2008-01-01

Full Text Available Objective: The objective of the present study was to evaluate early and late effects of radiation and a-tocopherol on the secretion rate of saliva and on selected saliva salivary parameters in oral cavity cancer patients. Patients & Methods: Eighty-nine histologically confirmed oral cavity cancer patients (OCC were enrolled in the study. Resting whole saliva was collected before, during and at the end of the radiation therapy (RT and simultaneous supplementation with α - tocopherol to the radiation treated patients (RT + AT. Results: Salivary flow rate, pH, amylase activity, total protein, sodium and potassium were analyzed. Increased pH, potassium and decreased flow rate, amylase activity, protein content and sodium were observed in 6 weeks of radiation treated patients when compared to OCC patients. A significant improvement of those parameters was observed on α - tocopherol supplementation in RT + AT patients. Conclusion: Supplementation with α - tocopherol improves the salivary flow rate thereby, maintains salivary parameters.

Activities of Moroccan Radiation Protection Association

International Nuclear Information System (INIS)

Choukri, A.

2010-01-01

Encourage activities and information exchange in the field of radiation protection and related areas; Assist in informing both the public and the professionals on the problems and requirements related to radiation protection for the protection of man and the environment; Promote professional training in radiation protection. The use of nuclear technology in medicine, agriculture and industry is very advanced in Morocco. This technological progress has been accompanied by fairly detailed legislation and significant involvement on the part of Morocco in international conventions and agreements

Radiation levels from computer monitor screens within Benue State ...

African Journals Online (AJOL)

Investigation of possible presence of soft X-ray levels from Computer Screens at distances of 0.5m and 1.0m was carried out within Benue State University, Makurdi, using ten different monitor models. Radiation measurement was carried out using a portable digital radiation meter, INSPECTOR 06250 (SE international Inc.

Radiation levels and countermeasure research on radiological protection in tin mine in china

International Nuclear Information System (INIS)

Yang Fengfang; Yuan Yongling

2010-01-01

Objective: To study the distribution of radiation level in our nation's tin mine, therefore comes up with proposals on radiological protection and provide scientific evidence on how to protect lives and health of worker underground in tin mine. Methods: To get the radiation level of the underground workplaces in tin mine by analysis of research papers and the measuring results from on-scene investigations. Results: Majority of the absorbed dose rates of γ radiation in the air of underground workplaces in tin mine falls within the range of radiation levels of normal background. Earlier, the typical values of radon concentration and potential alpha energy concentration of radon daughters in the air of underground workplaces in tin mine are 3.12 kBq/m 3 and 5.61 μJ/m 3 respectively. Now, radon concentration and potential alpha energy concentration of radon daughters in the air of underground workplaces in majority of tin mine are lower than 1000 Bq/m 3 and 3.57 μJ/m 3 . Conclusion: For these tin mine workers with an average of annual effective dose greater than 1 mSv or these of their specific activity for natural uranium in materials are greater than 1 Bq/g need to have regulation of radiological protection. The control limits for the radon concentration and the potential alpha energy concentration of radon daughters and the absorbed dose rates of γ radiation in the air of underground workplaces in tin mine are 1000 Bq/m3, 3.57 μJ/m 3 and 1 μGy/h respectively. The administrative individual dose for workers working under the ground of tin mine is 10 mSv/a. If a worker's total annual effective dose is greater than 10 mSv, he/she should be considered as radioactive worker. (authors)

Radiation safety in radioluminous paint workshop handling tritium activated paint

International Nuclear Information System (INIS)

Gaur, P.K.; Venkateswaran, T.V.

1986-01-01

This paper discusses the safety features related to a workshop when tritium activated luminous paint is handled by workmen. Salient features of the workshop and the methods employed for monitoring the radiation levels are briefly outlined and results are discussed. The importance of proper ventilation of the workplace and precautions to be taken in the storage of painted articles are highlighted. (author). 1 table, 3 figs

Low level ionizing radiation and human mortality: multi-regional epidemiological studies

International Nuclear Information System (INIS)

Hickey, R.J.; Bowers, E.J.; Spence, D.E.; Zemel, B.S.; Clelland, A.B.; Clelland, R.C.

1981-01-01

Analyses of relationships involving environmental chemicals, background radiation, and mortality rates for diseases of the heart and several cancer categories are presented. Bivariate correlation coefficients between radiation and mortality rate were significantly negative for cancer of the lung and respiratory organs, cancer of the buccal cavity and pharynx, cancer of the digestive organs and peritoneum, total cancer and diseases of the heart. Only the correlation coefficient between background radiation and leukemia-aleukemia was positive, and that not significantly positive. Initial multivariate statistical studies support the bivariate results in that all significant regression terms that represent background radiation have been negative. Background radiation level was not a significant predictor for leukemia-aleukemia mortality rate when examined without regard to age. This preliminary work suggests that any health effects of background radiation on the diseases studied do not exceed in magnitude those of environmental chemicals. It also suggests that models implying important long-term deleterious effects of low levels of ionizing radiation on humans may be invalid. (author)

Grazing rates of Calanus finmarchicus on Thalassiosira weissflogii cultured under different levels of ultraviolet radiation.

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David M Fields

Full Text Available UVB alters photosynthetic rate, fatty acid profiles and morphological characteristics of phytoplankton. Copepods, important grazers of primary production, select algal cells based upon their size, morphological traits, nutritional status, and motility. We investigated the grazing rates of the copepod Calanus finmarchicus on the diatom Thalassiosira weissflogii cultured under 3 levels of ultraviolet radiation (UVR: photosynthetically active radiation (PAR only (4 kJ-m(-2/day, and PAR supplemented with UVR radiation at two intensities (24 kJ-m(-2/day and 48 kJ-m(-2/day. There was no significant difference in grazing rates between the PAR only treatment and the lower UVR treatment. However, grazing rates were significantly (∼66% higher for copepods feeding on cells treated with the higher level of UVR. These results suggest that a short-term increase in UVR exposure results in a significant increase in the grazing rate of copepods and, thereby, potentially alters the flow rate of organic matter through this component of the ecosystem.

Active structural acoustic control for reduction of radiated sound from structure

International Nuclear Information System (INIS)

Hong, Jin Seok; Oh, Jae Eung

2001-01-01

Active control of sound radiation from a vibrating rectangular plate by a steady-state harmonic point force disturbance is experimentally studied. Structural excitation is achieved by two piezoceramic actuators mounted on the panel. Two accelerometers are implemented as error sensors. Estimated radiated sound signals using vibro-acoustic path transfer function are used as error signals. The vibro-acoustic path transfer function represents system between accelerometers and microphones. The approach is based on a multi-channel filtered-x LMS algorithm. The results shows that attenuation of sound levels of 11dB, 10dB is achieved

Activation of neuron generator of luciola mingrelica luminescence flashes under the effect of pulse X-radiation

International Nuclear Information System (INIS)

Bol'shakov, V.Yu.; Drobchenko, E.A.; Landa, S.B.; Pejmer, S.I.

1990-01-01

The effect of low-level pulse X-radiation on spontaneous photoactivity and luminous communicative behaviour of Luciola mingrelica has been investigated. It was shown that X-radiation doses of as low as 5x10 -5 Gy increased endogenous flashing activity and disinhibited the reaction of insects to light flashes imitating signals of mating partners. Powerful radiation pulses may influence significantly an instinctive behaviour and its neuronal organization

Examining a link between SPEs and ground level radiation

Science.gov (United States)

Overholt, Andrew

2015-01-01

Researchers have previously found a correlation between solar proton events (SPEs) and congenital malformations (CMs). A similar correlation has also been found between long term solar variability and CMs. We examine the ionizing radiation dose from these events as well as the largest events on record to determine whether these events are capable of producing these effects. We show that the total ionizing radiation dose (consisting of neutrons and muons) at ground level is insufficient for production of the observed increases in CM rate under the current paradigm regarding ionizing radiation from muons and neutrons. Current research on the subject shows that our assumptions regarding muonic ionizing radiation may be underestimating their biologic effect. We recommend further experimentation regarding the radiation dose due to muons, as this may prove to be a more substantial contribution to our radiation environment than previously assumed.

Time-resolved monitoring of outdoor radiation levels in the Netherlands

International Nuclear Information System (INIS)

Smetsers, R.C.G.M.; Blaauboer, R.O.

1994-01-01

Risk management applied to human-induced radiological problems requires proper knowledge of what the situation would be without human interference. In cases where enhanced levels of natural radioactivity are present, this is far from simple, due to the existence of comparatively high and variable natural background levels. More knowledge on the spatial and temporal variety of natural radiation can help to decrease the uncertainty in the assessment of radiation doses from human activities. To obtain quantitative descriptions of natural processes one needs accurate data showing a high resolution in time and space. This paper first shows that data obtained from the Dutch National Radioactivity Monitoring network, although developed for nuclear emergency management, meets these requirements. Next, some early, but interesting, results from a current comprehensive study are reported. Parameter values are given which describe the influence of air pressure, airborne radioactivity and rainfall on ambient dose rate. From the analysis of data distributions of ambient dose rate, information is obtained on the probability of elevated recordings occurring in a certain time period; this information can be used to select warning levels for nuclear alarm systems. Data analysis of airborne radioactivity shows that concentrations of 222 Rn progeny are highly dependent on wind speed and direction. Results obtained for low wind speeds can be used to examine radon characteristics of the local environment while other results yield (aggregated) information about more remote areas. (Author)

Health effects of low-level radiation in shipyard workers

International Nuclear Information System (INIS)

Matanoski, G.M.

1991-06-01

The Nuclear Shipyard Workers Study (NSWS) was designed to determine whether there is an excess risk of leukemia or other cancers associated with exposure to low levels of gamma radiation. The study compares the mortality experience of shipyard workers who qualified to work in radiation areas to the mortality of similar workers who hold the same types of jobs but who are not authorized to work in radiation areas. The population consists of workers from six government and two private shipyards

Radiation-induced progressive decreasing in the expression of reverse transcriptase gene of hEST2 and telomerase activity

International Nuclear Information System (INIS)

Zhu Hanneng; Chen Wenying; Xiong Sidong

2000-01-01

Telomerase is a ribonucleoprotein complex that adds heximeric repeats called telomeres to the growing ends of chromosomal DNA. Telomerase activity is present in a vast majority of tumors but is repressed in most normal tissues. Human telomerase catalytic subunit gene (hEST2) reverse transcriptase (RT) segment was cloned by PCR according to the sequence published in GeneBank. PCR was used to investigate the expression of the hEST2 RT segment in diverse tumors as well as in various normal tissues. Results indicated that hEST2 RT segment was detectable in tumor cells lines but not in normal cells and tissues. In order to identify the relationship between telomerase and the biological effect of radiation injury, HeLa cells, KB cells and A431 cells were employed to measure the change in telomerase activity after 60 Co-ray irradiation at RNA level and protein level. Quantitative PCR determined that expression of hEST2 RT segment that encodes seven motifs of the human telomeras decreased with increasing dosage of radiation. In addition, a PCR-based telomeric repeat amplification protocol was used to assay telomerase activity after exposure to radiation. The results strongly support the experiments we had made: Telomerase activity decreases with increasing dosage of radiation. We conclude that detection of the hEST2 RT segment by Northern blotting is a new method for detecting telomerase activity. Furthermore, radiation can cause a dose-dependent decrease in telomerase activity. The effect of radiation on telomerase is one possible reason for the death of cancer cells after irradiation. (author)

Radionuclide activity and the immune system functioning in residents of radiation contaminated areas

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V. L. Sokolenko

2015-09-01

Full Text Available The objective of this research is to assess the relation of radioactive contamination degree to immune system functioning, in the absence or presence of additional potential immunosuppressants. To achieve the objective, during the period of 1995–2015 we examined 250 people, students of Cherkasy State University, who lived in the areas of enhanced radiation monitoring before. Also we evaluated the additional impact of the emotional stress caused by examinations on examined students. Indicators of cellular immunity were determined by immunophenotyping and dyeing using Romanowsky-Giemsa method. The level of immunoglobulins in blood serum was determined by radial immunodiffusion (Mancini method. The level of cortisol in blood serum was determined by immunoenzyme method. We have found that in absence of the emotional stress among residents of the areas contaminated with radionuclides, cortisol level remained at the upper limit of homeostatic norm. There is an average positive correlation between the activity of radionuclides in the territories of residence and the level of cortisol. There are marked average positive correlations between the activity of radionuclides and the level of neutrophils, and low positive correlations with the levels of IgG and IgM in blood serum. Average negative correlations between the activity of radionuclides and the following parameters are also observed: absolute and relative number of functionally mature T-lymphocytes with phenotype CD3+, absolute and relative number of their helper subpopulation CD4+, absolute and relative number of natural killer cells with phenotype CD16+; and strong negative correlations with immunoregulatory index CD4+/CD8+. Cortisol level shows the similar correlation with the same parameters, but correlation coefficient is lower. Under conditions of additional stress, caused by emotional load during the examinations, cortisol level significantly increases. This enhanced previously discovered

Evaluation of radiation protection educational level of professional exposed workers

International Nuclear Information System (INIS)

Marinkovic, O.; Krstev, S.; Jovanovic, S.

2006-01-01

Full text: Serbia and Montenegro legislation concerning with radiation protection was upgrading after publication ICRP- 60 and B.S.S., No.115. Present Law on the Protection against Ionizing Radiation is in force from 1996. Among quite new issues in radiation protection regulations there was article relate to obligatory refresher training. Due to adverse political and economic situation through many years radiation protection regulations were not fulfill completely. The aim of this investigation was to get real view to education level of professional exposed workers. In Serbia and Montenegro the most of ionizing radiation sources are in medical use and the most exposed workers are radiographers and radiologists. The test was passed by 200 radiographers and 50 radiologists. Main groups of questions were: Radiation protection and safety; difference between safety and security; legislation: law and regulations; incidents, accidents and operational failures: recording, learning. Usually, knowledge from school pales. New quantities (as ambient and personal dose equivalent) are mostly unknown. It is easier to understand the real difference between safety and security than to understand linguistic differences. Discussing regulations workers are more interesting in syndicate regulations than radiation protection ones. Operational failures and incidents are hidden. Better to say: nobody dare to speak about them. The results imposed conclusion that regulatory body has to pay more attention to upraise safety culture and radiation protection education level of professional exposed workers. (authors)

Graphdiyne Nanoparticles with High Free Radical Scavenging Activity for Radiation Protection.

Science.gov (United States)

Xie, Jiani; Wang, Ning; Dong, Xinghua; Wang, Chengyan; Du, Zhen; Mei, Linqiang; Yong, Yuan; Huang, Changshui; Li, Yuliang; Gu, Zhanjun; Zhao, Yuliang

2018-03-06

Numerous carbon networks materials comprised of benzene moieties, such as graphene and fullerene, have held great fascination for radioprotection because of their acknowledged good biocompatibility and strong free radical scavenging activity derived from their delocalized π-conjugated structure. Recently, graphdiyne, a new emerging carbon network material consisting of a unique chemical structure of benzene and acetylenic moieties, has gradually attracted attention in many research fields. Encouraged by its unique structure with strong conjugated π-system and highly reactive diacetylenic linkages, graphdiyne might have free radical activity and can thus be used as a radioprotector, which has not been investigated so far. Herein, for the first time, we synthesized bovine serum albumin (BSA)-modified graphdiyne nanoparticles (graphdiyne-BSA NPs) to evaluate their free radical scavenging ability and investigate their application for radioprotection both in cell and animal models. In vitro studies indicated that the graphdiyne-BSA NPs could effectively eliminate the free-radicals, decrease radiation-induced DNA damage in cells, and improve the viability of cells under ionizing radiation. In vivo experiments showed that the graphdiyne-BSA NPs could protect the bone marrow DNA of mice from radiation-induced damage and make the superoxide dismutase (SOD) and malondialdehyde (MDA) (two kinds of vital indicators of radiation-induced injury) recover back to normal levels. Furthermore, the good biocompatibility and negligible systemically toxicity responses of the graphdiyne-BSA NPs to mice were verified. All these results manifest the good biosafety and radioprotection activity of graphdiyne-BSA NPs to normal tissues. Therefore, our studies not only provide a new radiation protection platform based on graphdiyne for protecting normal tissues from radiation-caused injury but also provide a promising direction for the application of graphdiyne in the biomedicine field.

The amount of DNA damage needed to activate the radiation-induced G2 checkpoint varies between single cells

International Nuclear Information System (INIS)

Tkacz-Stachowska, Kinga; Lund-Andersen, Christin; Velissarou, Angeliki; Myklebust, June H.; Stokke, Trond; Syljuåsen, Randi G.

2011-01-01

Background and purpose: The radiation-induced G2 checkpoint helps facilitate DNA repair before cell division. However, recent work has revealed that human cells often escape the G2 checkpoint with unrepaired DNA breaks. The purpose was to explore whether G2 checkpoint activation occurs according to a threshold level of DNA damage. Materials and methods: G2 checkpoint activation was assayed at 75–90 min and 24–48 h after X-ray irradiation of BJ diploid fibroblasts and U2OS osteosarcoma cells. Multiparameter flow cytometry with pacific blue barcoding, and flow cytometry-based sorting of phospho-H3 positive cells to microscope slides, were used to examine the DNA damage marker γ-H2AX in individual mitotic cells that had escaped the G2 checkpoint. Results: For all radiation doses and times tested, the number of γ-H2AX foci varied between individual mitotic cells. At 75 min the median levels of γ-H2AX in mitotic cells increased with higher radiation doses. At 24–48 h, following a prolonged G2 checkpoint, cells were more resistant to checkpoint re-activation by a second dose of radiation. Conclusion: Our results suggest that different amounts of DNA damage are needed to activate the G2 checkpoint in individual cells. Such single cell variation in checkpoint activation may potentially contribute to radiation-induced genomic instability.

Low salinity and high-level UV-B radiation reduce single-cell activity in antarctic sea ice bacteria.

Science.gov (United States)

Martin, Andrew; Hall, Julie; Ryan, Ken

2009-12-01

Experiments simulating the sea ice cycle were conducted by exposing microbes from Antarctic fast ice to saline and irradiance regimens associated with the freeze-thaw process. In contrast to hypersaline conditions (ice formation), the simulated release of bacteria into hyposaline seawater combined with rapid exposure to increased UV-B radiation significantly reduced metabolic activity.

How much can be learned from populations exposed to low levels of radiation

International Nuclear Information System (INIS)

Gilbert, E.S.

1984-05-01

The assessment of health effects from low-level exposure to radiation is a matter of considerable controversy. Many of the problems in analyzing and interpreting data on populations exposed to low levels of radiation are well illustrated by a current study of the effects on mortality of occupational exposure to radiation at the Hanford plant. The conclusion drawn is that the amount that can be learned from the Hanford population, and other populations exposed to low levels of radiation, is extremely limited. The data are not adequate to determine reliable estimates of risks, or to investigate the appropriateness of various models. Although there are problems in using data from populations exposed at high levels to estimate risks of low level exposure to radiation, the problems in obtaining such estimates directly are even more severe. Thus data from populations such as the Japanese A-bomb survivors and the British ankylosing spondylitis patients must continue to serve as our primary source of information on radiation effects. 27 references, 3 tables

Radiation activation of transcription factors in mammalian cells

International Nuclear Information System (INIS)

Kraemer, M.; Stein, B.; Mai, S.; Kunz, E.; Koenig, H.; Ponta, H.; Herrlich, P.; Rahmsdorf, H.J.; Loferer, H.; Grunicke, H.H.

1990-01-01

In mammalian cells radiation induces the enhanced transcription of several genes. The cis acting elements in the control region of inducible genes have been delimited by site directed mutagenesis. Several different elements have been found in different genes. They do not only activate gene transcription in response to radiation but also in response to growth factors and to tumor promoter phorbol esters. The transcription factors binding to these elements are present also in non-irradiated cells, but their DNA binding activity and their transactivating capability is increased upon irradiation. The signal chain linking the primary radiation induced signal (damaged DNA) to the activation of transcription factors involves the action of (a) protein kinase(s). (orig.)

Health and low-level radiation: turning good news into bad news

International Nuclear Information System (INIS)

Wolfe, B.; Wallis, L.R.

1988-01-01

This paper has a dual purpose. On the one hand, congratulations are in order; the 25th Hanford Life Sciences Symposium celebrates four decades of important research at Hanford. This research has helped provide a better understanding of ionizing radiation effects on man and his environment. Researchers at Hanford and those at other locations can take pride in the fact that today we know more about the major characteristics and potential health effects of ionizing radiation than we do for any other biological hazard. Ionizing radiation's present mysteries, important as they are, involve subtleties that are difficult to explore in detail because the effects are so small relative to other health effects. It will also be a pleasure to add our tribute, along with many others, to Herb Parker, a friend, colleague, and pioneer in the radiation protection field. Building on the work of early pioneers such as Herb and those who have and will follow in their footsteps, we will develop an even broader understanding--an understanding that will clarify the effects of low-level radiation exposure, an area of knowledge about which sound explanations and predictions elude us today. The second purpose of this paper is to remind those in the radiation protection field that they have been less than successful in one of their most important tasks--that of effective communication. The task is not an easy one because the content of the message depends upon the dose. At high doses, above 1 Sv, where the deleterious effects of radiation are predictable, there is agreement on the message that must be delivered to the public: avoid it. There is no confusion in the public sector about this message. At the much lower doses resulting from beneficial activities, the message we must convey to the public is different

Radiation Dose Contribution To The Worker Health Level At Serpong Area

International Nuclear Information System (INIS)

Yuwono, Indro

2000-01-01

Analysis of internal and external radiation doses received for radiation and non-radiation workers of P2TBDU have been done. In the period of 1997/1998 and 1998/1999 there were no significant increasing level of radiation doses received that was 0.55 mSv and highest received radiation dose was 2.66% from dose limit value. Increasing of healthy difference on the same period was 5.76%. Increasing of healthy difference no cause by increasing of radiation dose received but maybe the food consumption design

Epidemiological studies on the effects of low-level ionizing radiation on cancer risk

International Nuclear Information System (INIS)

Akiba, Suminori

2010-01-01

The health effects of low-level ionizing radiation are yet unclear. As pointed out by Upton in his review (Upton, 1989), low-level ionizing radiation seems to have different biological effects from what high-level radiation has. If so, the hazard identification of ionizing radiation should he conducted separately for low- and high-level ionizing radiation; the hazard identification of low-level radiation is yet to be completed. What makes hazard identification of ionizing radiation difficult, particularly in the case of carcinogenic effect, is the difficulty in distinguishing radiation-induced cancer from other cancers with respect to clinicopathological features and molecular biological characteristics. Actually, it is suspected that radiation-induced carcinogenesis involves mechanisms not specific for radiation, such as oxidative stress. Excess risk per dose in medium-high dose ranges can be extrapolated to a low-dose range if dose-response can be described by the linear-non-threshold model. The cancer risk data of atomic-bomb survivors describes leukemia risk with a linear-quadratic (LQ) model and solid-cancer risk with linear non-threshold (LNT) model. The LQ model for leukemia and the LNT model for solid cancer correspond to the two-hit model and the one-hit model, respectively. Although the one-hit model is an unlikely dose-response for carcinogenesis, there is no convincing epidemiological evidence supporting the LQ model or non-threshold model for solid cancer. It should be pointed out, however, even if the true dose response is non-linear various noises involved in epidemiological data may mask the truth. In this paper, the potential contribution of epidemiological studies on nuclear workers and residents in high background radiation areas will be discussed. (author)

Effect of low doses of ionizing radiation on circulating microparticles levels

International Nuclear Information System (INIS)

Ekhtiar, A.; Al-Massarani, Gh.; Najjar, F.; Aljapawe, A.

2015-01-01

Ionizing radiation is known to cause disruption of cytoskeleton. Cytoskeleton disorganization results in circulating microvesicles (MVs). The aim of this study was to investigate the relationship between the exposure to low-radiation and MVs levels in the peripheral blood of individuals working in radiation technology field.(author)

Initial activities of a radiation emergency medical assistance team to Fukushima from Nagasaki

International Nuclear Information System (INIS)

Matsuda, Naoki; Yoshida, Kouji; Nakashima, Kanami; Iwatake, Satoshi; Morita, Naoko; Ohba, Takashi; Yusa, Takeshi; Kumagai, Atsushi; Ohtsuru, Akira

2013-01-01

As an urgent response to serious radiological accidents in the Fukushima Daiichi nuclear power plant, the radiation emergency medical assistance team (REMAT) from Nagasaki University landed at Fukushima on March 14, 2011, two days after the initiation of radiation crisis by the hydrogen explosion at Unit-1 reactor. During a succession of unexpected disasters, REMAT members were involved in various activities for six days, such as setting the base for radiological triage at the Fukushima Medical University, considerations for administration of stable iodine, and risk communication with health care workers. This report briefly describes what happened around REMAT members and radiation doses measured during their activities. -- Highlights: ► The radiation emergency medical assistance team from Nagasaki was sent to Fukushima. ► The practical action level for body surface contamination was 100 kcpm. ► The ambient radiation dose in Fukushima drastically elevated on March 15, 2011. ► Higher than 10 kBq of I-131, Cs-134, and Cs-137 were detected in soil samples. ► The effective dose of the team members ranged between 51.7 and 127.8 μSv in 6 days

Determination of radiation levels by neutrons in an accelerator for radiotherapy

International Nuclear Information System (INIS)

Paredes G, L.; Salazar B, M.A.; Genis S, R.

1998-01-01

It was determined the radiation levels by neutrons due to photonuclear reactions (γ, n) which occur in the target, levelling filter, collimators and the small pillow blinding of a medical accelerator Varian Clinac 2100C of 18 MeV, using thermoluminescent dosemeters UD-802AS and US-809AS. The experimental values were presented for the patient level, inside and outside of the radiation field, as well as for the small pillow. (Author)

Low-level dosimetry based on activation analysis of badge film, 1

International Nuclear Information System (INIS)

Morikawa, Kaoru; Yamashita, Kazuya; Inamoto, Kazuo; Maeda, Masayuki; Sato, Takashi; Ono, Koichi.

1988-01-01

Underexposed badge film contains a minor quantity of silver which corresponds to the low radiation dose even after completion of the photographic densitometry ; however, it cannot be detected with a photographic densitometer. We intended to clarify the minor silver content based on radioactivation analysis with thermal neutrons at KUR (Kyoto University Research Reactor). The natural silver consists of two stable nuclides, i.e., 107 Ag and 109 Ag. These can be activated with irradiation of thermal neutrons to two radionuclides, i.e., 108 Ag and 110 Ag. In this paper, through the activation analysis of an underexposed badge film, methods of measurements are shown regarding both 108 Ag produced by the 107 Ag (n, γ) reaction and 110 Ag by the 109 Ag (n, γ). After underexposed badge films were irradiated with thermal neutrons, some gamma-rays emitted from the radionuclides in the activated films were measured with a high pure Ge detector or a NaI (Tl) scintillation detector. The following results were obtained: (1) several elements such as silver, iodine, gold, antimony, manganese and copper were detected by activation analyses of films exposed to low level 60 Co gamma-rays, (2) the exposure vs 108 Ag or 110 Ag activity curve was linear in the lower dose range of 60 Co gamma-rays. These data indicate that low level radiation doses, which is indeterminable by ordinary photographic densitometry, can be estimated by activation analysis of silver atoms in badge films. (author)

Resistance of Feather-Associated Bacteria to Intermediate Levels of Ionizing Radiation near Chernobyl.

Science.gov (United States)

Ruiz-González, Mario Xavier; Czirják, Gábor Árpád; Genevaux, Pierre; Møller, Anders Pape; Mousseau, Timothy Alexander; Heeb, Philipp

2016-03-15

Ionizing radiation has been shown to produce negative effects on organisms, although little is known about its ecological and evolutionary effects. As a study model, we isolated bacteria associated with feathers from barn swallows Hirundo rustica from three study areas around Chernobyl differing in background ionizing radiation levels and one control study site in Denmark. Each bacterial community was exposed to four different γ radiation doses ranging from 0.46 to 3.96 kGy to test whether chronic exposure to radiation had selected for resistant bacterial strains. Experimental radiation duration had an increasingly overall negative effect on the survival of all bacterial communities. After exposure to γ radiation, bacteria isolated from the site with intermediate background radiation levels survived better and produced more colonies than the bacterial communities from other study sites with higher or lower background radiation levels. Long-term effects of radiation in natural populations might be an important selective pressure on traits of bacteria that facilitate survival in certain environments. Our findings indicate the importance of further studies to understand the proximate mechanisms acting to buffer the negative effects of ionizing radiation in natural populations.

Low level radiation: how low can you get?

International Nuclear Information System (INIS)

Townsley, M.

1990-01-01

Information stored on the world's largest data bank concerning the health of nuclear industry workers is to be handed over to researchers at Birmingham University by the US Department of Energy. The data bank contains detailed information on 300,000 nuclear employees, going back to the 1940s. Such a large sample size will allow the results of a previous study conducted on workers in the US nuclear industry to be verified. That study was concluded in 1978 and showed that the risk estimates set by the International Commission on Radiological Protection (ICRP) were between 10 and 30 times too low. The current ICRP estimate allows workers up to 50mSv of exposure to low level radiation per year. Risk estimates have been derived from data relating to the atomic bombings of Hiroshima and Nagasaki. However in those cases the radiation doses were relatively high but over a short period. In the nuclear industry the doses are lower but are long term and this may account for the apparent anomalies such as the incidence of leukaemia amongst children whose fathers have worked in the nuclear industry compared with that for the children whose fathers received radiation doses from the atomic bombings. It is expected the study will show that low-level radiation is more damaging than has previously been thought. (author)

Outdoor radiofrequency radiation levels in the West Bank-Palestine.

Science.gov (United States)

Lahham, Adnan; Hammash, Alaa

2012-05-01

This work presents the results of exposure levels to radio frequency (RF) emission from different sources in the environment of the West Bank-Palestine. These RF emitters include FM and TV broadcasting stations and mobile phone base stations. Power densities were measured at 65 locations distributed over the West Bank area. These locations include mainly centres of the major cities. Also a 24 h activity level was investigated for a mobile phone base station to determine the maximum activity level for this kind of RF emitters. All measurements were conducted at a height of 1.7 m above ground level using hand held Narda SRM 3000 spectrum analyzer with isotropic antenna capable of collecting RF signals in the frequency band from 75 MHz to 3 GHz. The average value of power density resulted from FM radio broadcasting in all investigated locations was 0.148 μW cm(-2), from TV broadcasting was 0.007 μW cm(-2) and from mobile phone base station was 0.089 μW cm(-2). The maximum total exposure evaluated at any location was 3.86 μW cm(-2). The corresponding exposure quotient calculated for this site was 0.02. This value is well below unity indicating compliance with the International Commission on non-ionising Radiation protection guidelines. Contributions from all relevant RF sources to the total exposure were evaluated and found to be ~62 % from FM radio, 3 % for TV broadcasting and 35 % from mobile phone base stations. The average total exposure from all investigated RF sources was 0.37 μW cm(-2).

Low LET radiation-induced telomerase catalytic subunit promoter activation is mediated by nuclear factor Kappa B

International Nuclear Information System (INIS)

Natarajan, M.; Hong, F.A.; Mohan, S.; Herman, T.S.

2003-01-01

Full text: The objective of this study is to understand whether low doses of low LET radiation induces survival advantage in normal cells. As an increase in telomerase activity is associated with longevity and cell proliferation, we examined the telomerase response following gamma-irradiation in normal aortic endothelial cells. Telomeric Repeat Amplification Protocol assay following low LET radiation showed an increase in telomerase enzyme activity as early as 8 h post irradiation and reaches its maximum at 24 h. Subsequent analysis revealed that the increased telomerse enzyme activity is due to increased synthesis resulting from an increased transcription. Examination of transcriptional activation of telomerase reverse transcriptase (TERT) promoter regulation showed an enhanced transcription of the telomerse gene following gamma-irradiation. In our previous reports we documented an increase in NF-kB DNA-binding property following low LET radiation (3). Therefore, to determine whether the activation of NF-kB-signaling is responsible for induced TERT promoter activation, cells transiently transfected with minimal promoter region of TERT containing wild type or mutant NF-kB binding site were examined following low LET radiation. TERT promoter activation was induced in wild type transfected cells whereas, in mutant kB binding site, the activation remained at the basal level similar to that of un-irradiated cells. More significantly, the gamma-ray mediated promoter activation of telomerase gene as well as induce telomerase enzyme activity was abrogated by ectopically expressing the IkBa mutant (IkBa (S32A/S36A)), which blocks NF-kB activation. The results thus suggest that exposure to low LET radiation could induce telomerase activity and the activation is at least, in part, mediated by the transcription factor NF-kB. Sustained activation of telomerase in these cells after low LET radiation may impart extended life span

Professional exposure of medical workers: radiation levels, radiation risk and personal dose monitoring

International Nuclear Information System (INIS)

Bai Guang

2005-01-01

The application of radiation in the field of medicine is the most active area. Due to the rapid and strong development of intervention radiology at present near 20 years, particularly, the medical workers become a popularize group which most rapid increasing and also receiving the must high of professional exposure dose. Because, inter alias, radiation protection management nag training have not fully follow up, the aware of radioactive protection and appropriate approach have tot fully meet the development and need, the professional exposure dose received by medical workers, especially those being engaged in intervention radiology, are more higher, as well as have not yet fully receiving the complete personal dose monitoring, the medical workers become the population group which should be paid the most attention to. The writer would advice in this paper that all medical workers who being received a professional radiation exposure should pay more attention to the safety and healthy they by is strengthening radiation protection and receiving complete personal dose monitoring. (authors)

Change of nucleolus characteristic of fish embryo cells under the influence of low-level radiation

International Nuclear Information System (INIS)

Arkhipchuk, V.V.

1995-01-01

The nucleolus activity of fish embryo cells was stimulated by low-level radiation at a dose rate of 2-13 mGy/h. The size of nucleoli generally increased in embryos of Cyprinus carpio, whereas the number of nucleoli was greater in embryos of Carassius auratus gibelio. The higher the functional activity of nucleolus is, the more pronounced are changes in the characteristics. The size of single nucleolus at gastrulation is the most sensitive characteristic. 16 refs.; 1 tab

Radiation Levels around the LHC

CERN Document Server

Mala, P; Calviani, M; Nordt, A

2013-01-01

This work discuss on the radiation levels measured around the LHC machine during the 2012 operational year. The doses and particle fluences are measured primarily by RadMon detectors – about 300 RadMons are installed around the accelerator – and by thermoluminescent detectors. In addition, BLMs, IG5/PMI ionisation chambers as well as FGCs can be used for corresponding cumulated dose evaluations. The probability of SEE depends directly on the high-energy hadron (HEH) fluence, so this is the main parameter that is calculated based on RadMons counts.

Environmental radiation levels around Nuclear Fuel Complex, Hyderabad during 1981-1988

International Nuclear Information System (INIS)

Mehta, Navnit; Lakshmanan, A.R.; Kathuria, S.P.; Nambi, K.S.V.

1989-01-01

This report presents environmental radiation monitoring results around Nuclear Ffuel Complex (NFC) at Hyderabad for the period, 1981-'88. During 1981-'83 only indoor radiations were monitored at 12 locations in the region of about 15 km. radius around NFC plant. However, during 1984-'88 both indoor and outdoor monitoring was done in a standardised manner at 8 locations. In this routine monitoring programme, environmental thermoluminescent dosimeters were used in quarterly integrating cycles. The average outdoor natural radiation level around NFC during 1984-'88 is found to be 227 ± 34 (σ) mR/y, which is the highest among the various sites in the country where DAE units are located. Such a high level of natural background radiation in and around Hyderabad is due to granitic terrains which normally have significant amounts of primordial radioactivity. The indoor to outdoor radiation ratio is found to be 1.35 ± 0.1 (σ). Application of this ratio on all the available indoor radiation monitoring results of 1981-'88 gives an estimate of 230 ± 26 mR/y as the average outdoor radiation level, and this is in very close agreement with the directly measured value mentioned earlier. The temporal variations seen in the quarterly results of each location have been tested for Normal and Log-Normal distributions and found to yield satisfactory correlations, although the plots reveal slight skewness; the latter however, could not be attributed to the NFC operations. (author). 7 refs., 4 tabs., 12 figs

Practical radiation protection

International Nuclear Information System (INIS)

Brouwer, G.; Van den Eijnde, J.H.G.M.

1997-01-01

This textbook aims at providing sufficient knowledge and insight to carry out correctly radiation protection activities and operations. The subjects are appropriate for the training of radiation protection experts for the levels 5A (encapsulated sources, X rays) and 5B (open sources, laboratory activities)

Radiation and man - evaluation of biological and environmental low level radiation effects

International Nuclear Information System (INIS)

Riklis, E.

1977-01-01

The harmful effects of acute radiation cannot be resolved by statistical means and require clearer knowledge of mechanisms of action and much wider collection of human experience before any definite sound stand can be taken. Much information has accumulated from animal experiments, and still the interpretations are not always clearcut, but for human experience it is only the occasional accident which can give a direct answer. Some of the phenomena attributed to low dose radiation are summarized. There are regions of radiation exposure about which we have only limited positive knowledge, an all low-dose risk estimates have been based on effects observed at relatively high doses. Much information has been gathered which does not support the severity of former basic principles, especially our knowledge of mechanisms of repair existing in most cells as natural defence against the damages caused by radiation as well as by many chemicals which act as mutagenic and carcinogenic agents. Understanding these mechanism, their scope of action and their availability to a damaged cell and organism will lead towards modification of the acceptable permissible exposures, in some cases towards severity, but in most cases towards leniency and higher values. For the evaluation of the effects of low level low dose-rate radiations, whether external, or from internal deposition of isotopes, only late somatic and genetic effects should be considered. (B.G.)

Novel Concrete Chemistry Achieved with Low Dose Gamma Radiation Curing and Resistance to Neutron Activation

Science.gov (United States)

Burnham, Steven Robert

As much as 50% of ageing-related problems with concrete structures can be attributed to con-struction deficiencies at the time of placement. The most influential time affecting longevity of concrete structures is the curing phase, or commonly the initial 28 days following its placement. A novel advanced atomistic analysis of novel concrete chemistry is presented in this dissertation with the objective to improve concrete structural properties and its longevity. Based on experiments and computational models, this novel concrete chemistry is discussed in two cases: (a) concrete chemistry changes when exposed to low-dose gamma radiation in its early curing stage, thus improving its strength in a shorter period of time then curing for the conventional 28 days; (b) concrete chemistry is controlled by its atomistic components to assure strength is not reduced but that its activation due to long-term exposure to neutron flux in nuclear power plants is negligible. High dose gamma radiation is well documented as a degradation mechanism that decreases concrete's compressive strength; however, the effects of low-dose gamma radiation on the initial curing phase of concrete, having never been studied before, proved its compressive strength increases. Using a 137 Cs source, concrete samples were subjected to gamma radiation during the initial curing phase for seven, 14, and 28 days. The compressive strength after seven days is improved for gamma cured concrete by 24% and after 14 days by 76%. Concrete shows no improvement in compressive strength after 28 days of exposure to gamma radiation, showing that there is a threshold effect. Scanning Electron Microscopy is used to examine the microstructure of low-dose gamma radiation where no damage to its microstructure is found, showing no difference between gamma cured and conventionally cured concrete. Molecular dynamics modeling based on the MOPAC package is used to study how gamma radiation during the curing stage improves

Experience of water chemistry and radiation levels in Swedish BWRs

International Nuclear Information System (INIS)

Ivars, R.; Elkert, J.

1981-01-01

From the BWR operational experience in Sweden it has been found that the occupational radiation exposures have been comparatively low in an international comparison. One main reason for the favourable conditions is the good water chemistry performance. This paper deals at first with the design considerations of water chemistry and materials selection. Next, the experience of water chemistry and radiation levels are provided. Finally, some methods to further reduce the radiation sources are discussed. (author)

Characterizing dose response relationships: Chronic gamma radiation in Lemna minor induces oxidative stress and altered polyploidy level

International Nuclear Information System (INIS)

Van Hoeck, Arne; Horemans, Nele; Van Hees, May; Nauts, Robin; Knapen, Dries; Vandenhove, Hildegarde; Blust, Ronny

2015-01-01

The biological effects and interactions of different radiation types in plants are still far from understood. Among different radiation types, external gamma radiation treatments have been mostly studied to assess the biological impact of radiation toxicity in organisms. Upon exposure of plants to gamma radiation, ionisation events can cause, either directly or indirectly, severe biological damage to DNA and other biomolecules. However, the biological responses and oxidative stress related mechanisms under chronic radiation conditions are poorly understood in plant systems. In the following study, it was questioned if the Lemna minor growth inhibition test is a suitable approach to also assess the radiotoxicity of this freshwater plant. Therefore, L. minor plants were continuously exposed for seven days to 12 different dose rate levels covering almost six orders of magnitude starting from 80 μGy h"−"1 up to 1.5 Gy h"−"1. Subsequently, growth, antioxidative defence system and genomic responses of L. minor plants were evaluated. Although L. minor plants could survive the exposure treatment at environmental relevant exposure conditions, higher dose rate levels induced dose dependent growth inhibitions starting from approximately 27 mGy h"−"1. A ten-percentage growth inhibition of frond area Effective Dose Rate (EDR_1_0) was estimated at 95 ± 7 mGy h"−"1, followed by 153 ± 13 mGy h"−"1 and 169 ± 12 mGy h"−"1 on fresh weight and frond number, respectively. Up to a dose rate of approximately 5 mGy h"−"1, antioxidative enzymes and metabolites remained unaffected in plants. A significant change in catalase enzyme activity was found at 27 mGy h"−"1 which was accompanied with significant increases of other antioxidative enzyme activities and shifts in ascorbate and glutathione content at higher dose rate levels, indicating an increase in oxidative stress in plants. Recent plant research hypothesized that environmental genotoxic

Radiation shielding activities at the OECD/Nuclear Energy Agency

International Nuclear Information System (INIS)

Sartori, Enrico; Vaz, Pedro

2000-01-01

The OECD Nuclear Energy Agency (NEA) has devoted considerable effort over the years to radiation shielding issues. The issues are addressed through international working groups. These activities are carried out in close co-ordination and co-operation with the Radiation Safety Information Computational Center (RSICC). The areas of work include: basic nuclear data activities in support of radiation shielding, computer codes, shipping cask shielding applications, reactor pressure vessel dosimetry, shielding experiments database. The method of work includes organising international code comparison exercises and benchmark studies. Training courses on radiation shielding computer codes are organised regularly including hands-on experience in modelling skills. The scope of the activity covers mainly reactor shields and spent fuel transportation packages, but also fusion neutronics and in particular shielding of accelerators and irradiation facilities. (author)

Measurement of Background Gamma Radiation Levels at Two ...

African Journals Online (AJOL)

MICHAEL

ABSTRACT: An in-situ measurement of the background radiation level was carried out at the vicinity of three ... Soil contains small quantities of radioactive elements along with their progeny. .... assessment for soil samples from Kestanbol.

Levels of p21WAF1/CIP1 do not affect radiation-induced cell death in human breast epithelial cells

International Nuclear Information System (INIS)

Kim, Harold E.; Han, Sue J.; Waid, David; Lee, Yong J.; Kim, Hyeong-Reh Choi

1997-01-01

Purpose/Objective: Loss of the wild-type p53 activity and/or overexpression of the proto-oncogene bcl-2 are frequently detected in breast cancer and suggested to be related to resistance to chemotherapy and radiation therapy. The long-term goals of this study are to identify the downstream signaling molecules for anti-proliferative and apoptotic activities of p53 and to investigate the interaction of bcl-2 with p53 in human breast epithelial cells. We previously showed that overexpression of bcl-2 downregulates radiation-induced expression of p21 WAF1/CIP1 , a p53 downstream molecule that functions to inhibit cyclin dependent kinases, and suppresses radiation-induced apoptosis in human breast epithelial cell line (MCF10A). In this study, we investigated the role of p21 WAF1/CIP1 in radiation-induced cell death in MCF10A cells. Materials and Methods: To determine whether downregulation of p21 WAF1/CIP1 is required for anti-apoptotic activity of bcl-2, and to investigate the roles of p21 WAF1/CIP1 in cell death following irradiation, we transfected p21 WAF1/CIP1 expression vector into bcl-2 overexpressing MCF10A cells. The effects of p21 WAF1/CIP1 overexpression on cell growth, radiation-induced apoptosis and clonogenic cell survival were analyzed. Results: Overexpression of p21 WAF1/CIP1 resulted in marked growth inhibition, but no effect on dose-dependent radiation-induced cell lethality as determined by clonogenic survival assay. Radiation-induced apoptosis was not detected in bcl-2 overexpressing MCF10A cells independent of levels of p21 WAF1/CIP1 expression. Conclusion: This study suggests that bcl-2 downregulation of p21 WAF1/CIP1 is independent of anti-apoptotic activity of bcl-2 and that levels of p21 WAF1/CIP1 do not affect radiation-induced cell death in human breast epithelial cells

Influence of 2. 45 GHz microwave radiation on enzyme activity

Energy Technology Data Exchange (ETDEWEB)

Galvin, M J; Parks, D L; McRee, D I

1981-05-01

The in vitro activity of acetylcholinesterase and creatine phosphokinase was determined during in vitro exposure to 2.45 GHz microwave radiation. The enzyme activities were examined during exposure to microwave radiation at specific absorption rates (SAR) of 1, 10, 50, and 100 mW/g. These specific absorption rates had no effect on the activity of either enzyme when the temperature of the control and exposed samples were similar. These data demonstrate that the activity of these two enzymes is not affected by microwave radiation at the SARs and frequency employed in this study.

Activation of eNOS in endothelial cells exposed to ionizing radiation involves components of the DNA damage response pathway

Energy Technology Data Exchange (ETDEWEB)

Nagane, Masaki; Yasui, Hironobu; Sakai, Yuri; Yamamori, Tohru [Laboratory of Radiation Biology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan); Niwa, Koichi [Laboratory of Biochemistry, Department of Food and Cosmetic Science, Faculty of Bioindustry, Tokyo University of Agriculture, Abashiri 099-2493 (Japan); Hattori, Yuichi [Department of Molecular and Medical Pharmacology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan); Kondo, Takashi [Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194 (Japan); Inanami, Osamu, E-mail: inanami@vetmed.hokudai.ac.jp [Laboratory of Radiation Biology, Department of Environmental Veterinary Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo 060-0818 (Japan)

2015-01-02

Highlights: • eNOS activity is increased in BAECs exposed to X-rays. • ATM is involved in this increased eNOS activity. • HSP90 modulates the radiation-induced activation of ATM and eNOS. - Abstract: In this study, the involvement of ataxia telangiectasia mutated (ATM) kinase and heat shock protein 90 (HSP90) in endothelial nitric oxide synthase (eNOS) activation was investigated in X-irradiated bovine aortic endothelial cells. The activity of nitric oxide synthase (NOS) and the phosphorylation of serine 1179 of eNOS (eNOS-Ser1179) were significantly increased in irradiated cells. The radiation-induced increases in NOS activity and eNOS-Ser1179 phosphorylation levels were significantly reduced by treatment with either an ATM inhibitor (Ku-60019) or an HSP90 inhibitor (geldanamycin). Geldanamycin was furthermore found to suppress the radiation-induced phosphorylation of ATM-Ser1181. Our results indicate that the radiation-induced eNOS activation in bovine aortic endothelial cells is regulated by ATM and HSP90.

Low level radiation testing of micro-electronic components. Pt. 1

International Nuclear Information System (INIS)

Farren, J.; Stephen, J.H.; Mapper, D.; Sanderson, T.K.; Hardman, M.

1984-05-01

A review of the existing literature has been carried out, dealing with the current technology relating to low level radiation testing of microelectronic devices, as used in space satellite systems. After consideration of the space radiation environment, the general effects of cosmic radiation on MOSFET structures and other MOS devices have been assessed. The important aspect of annealing phenomena in relation to gamma-ray induced damage has also been reviewed in detail. The experimental and theoretical aspects of radiation testing have been assessed, with particular reference to the Harwell LORAD low level irradiation test facility. In addition, a review of modern dosimetry methods has been carried out, with specific regard to the problems of accurately measuring low radiation fields (1 to 10 R/hour) over periods of many months. Finally, a detailed account of the proposed experimental programme to be carried out in the LORAD facility is presented, and aspects of the experimental set-up discussed. The particular types of test circuits to be studied are dealt with, and full consideration is given to the various CMOS memory devices of special interest in the ESA space satellite programme. (author)

Therapeutic efficacy of inosine against radiation-induced damage at cellular, biochemical and chromosomal levels in swiss albino mice

International Nuclear Information System (INIS)

El-Shamy, E.; Sallam, M. H.

2010-01-01

Inosine has been used for treatment of various diseases and disorders in medicine. Modulator effect of inosine against γ radiation-induced histological alterations in testis, reduced glutathione (GSH), lipid peroxidation (LPO), acid and alkaline phosphatases activities (AP and ALP) and chromosomal aberrations (CA) in mice was studied at various experimental intervals between 1 and 30 days. Mice exposed to 8 Gy γ-rays showed acute radiation sickness including marked testis histological changes and chromosomal aberrations (CA) in bone marrow cells with 100 % mortality within 22 days. When inosine was given orally at a dose of 80 mg/ kg body wt for 15 consecutive days after exposure to γ-rays, death in radiation + inosine group was reduced to 70 % at 30 days. The radiation - dose reduction factor (DRF) was 1.43. There was significantly lesser degree of damage to testis tissue architecture and various cell populations including spermatogonia, spermatids and leydig cells. Correspondingly, a significant decrease in the LPO and increase in the GSH levels were observed in testis of radiation + inosine group. Similarly, a significant decrease in level of AP and increase in level of ALP were observed. Inosine treatment significantly prevented γ-rays-induced CA frequency in bone marrow cells.

Doses of low level ionizing radiation; a misunderstood risk, however unavoidable

International Nuclear Information System (INIS)

Nicolli, D.

1988-01-01

The treatment given by international organizations and associations to the problems of radiation exposures, and the recommendations and norms for calculating risks of low level radiation are analysed. It is shown that there are not zero risks for nuclear energy, and emphasis is given to the risks of natural radiation from environment. (M.C.K.) [pt

The environmental radiation monitoring system and in-situ measurements for early notification and OIL (Operational Intervention Levels) calculations

International Nuclear Information System (INIS)

Haquin, G.; Ne'eman, E.; Brenner, S.; Lavi, N.

1997-01-01

The efficiency of the environmental radiation monitoring, low level laboratory and in-situ gamma-ray spectrometry are evaluated as the systems for early notification and for determination of dose rate in air, surface contamination and activity concentration in food during emergencies for Operational Intervention Levels (OIL) recalculation.The National Environmental Radiation Monitoring System has proved its efficiency in the early detection of unregistered radiography work. A mobile station of the network can be used for absorbed dose rate measurement during emergencies in contaminated areas. The calibrated in-situ gamma-ray spectrometry system in an open phosphate ore mine has showed the efficiency of this technique for fast and accurate determination of soil activity concentration. The calibration for an uniform depth distribution can be easily mathematically converted to an exponential depth distribution in cases of radioactive material fallout

Hybrid Active-Passive Radiation Shielding System

Data.gov (United States)

National Aeronautics and Space Administration — A radiation shielding system is proposed that integrates active magnetic fields with passive shielding materials. The objective is to increase the shielding...

Radioactivity levels in the mostly local foodstuff consumed by residents of the high level natural radiation areas of Ramsar, Iran.

Science.gov (United States)

Fathabadi, Nasrin; Salehi, Ali Akbar; Naddafi, Kazem; Kardan, Mohammad Reza; Yunesian, Masud; Nodehi, Ramin Nabizadeh; Deevband, Mohammad Reza; Shooshtari, Molood Gooniband; Hosseini, Saeedeh Sadat; Karimi, Mahtab

2017-04-01

Among High Level Natural Radiation Areas (HLNRAs) all over the world, the northern coastal city of Ramsar has been considered enormously important. Many studies have measured environmental radioactivity in Ramsar, however, no survey has been undertaken to measure concentrations in the diets of residents. This study determined the 226 Ra activity concentration in the daily diet of people of Ramsar. The samples were chosen from both normal and high level natural radiation areas and based on the daily consumption patterns of residents. About 150 different samples, which all are local and have the highest consumption, were collected during the four seasons. In these samples, after washing and drying and pretreatment, the radionuclide was determined by α-spectrometry. The mean radioactivity concentration of 226 Ra ranged between 5 ± 1 mBq kg -1 wet weight (chino and meat) to 725 ± 480 mBq kg -1 for tea dry leaves. The 226 Ra activity concentrations compared with the reference values of UNSCEAR appear to be higher in leafy vegetables, milk and meat product. Of the total daily dietary 226 Ra exposure for adults in Ramsar, the largest percentage was from eggs. The residents consuming eggs from household chickens may receive an elevated dose in the diet. Copyright © 2016. Published by Elsevier Ltd.

Characterizing dose response relationships: Chronic gamma radiation in Lemna minor induces oxidative stress and altered polyploidy level.

Science.gov (United States)

Van Hoeck, Arne; Horemans, Nele; Van Hees, May; Nauts, Robin; Knapen, Dries; Vandenhove, Hildegarde; Blust, Ronny

2015-12-01

The biological effects and interactions of different radiation types in plants are still far from understood. Among different radiation types, external gamma radiation treatments have been mostly studied to assess the biological impact of radiation toxicity in organisms. Upon exposure of plants to gamma radiation, ionisation events can cause, either directly or indirectly, severe biological damage to DNA and other biomolecules. However, the biological responses and oxidative stress related mechanisms under chronic radiation conditions are poorly understood in plant systems. In the following study, it was questioned if the Lemna minor growth inhibition test is a suitable approach to also assess the radiotoxicity of this freshwater plant. Therefore, L. minor plants were continuously exposed for seven days to 12 different dose rate levels covering almost six orders of magnitude starting from 80 μGy h(-1) up to 1.5 Gy h(-1). Subsequently, growth, antioxidative defence system and genomic responses of L. minor plants were evaluated. Although L. minor plants could survive the exposure treatment at environmental relevant exposure conditions, higher dose rate levels induced dose dependent growth inhibitions starting from approximately 27 mGy h(-1). A ten-percentage growth inhibition of frond area Effective Dose Rate (EDR10) was estimated at 95 ± 7 mGy h(-1), followed by 153 ± 13 mGy h(-1) and 169 ± 12 mGy h(-1) on fresh weight and frond number, respectively. Up to a dose rate of approximately 5 mGy h(-1), antioxidative enzymes and metabolites remained unaffected in plants. A significant change in catalase enzyme activity was found at 27 mGy h(-1) which was accompanied with significant increases of other antioxidative enzyme activities and shifts in ascorbate and glutathione content at higher dose rate levels, indicating an increase in oxidative stress in plants. Recent plant research hypothesized that environmental genotoxic stress conditions

Health physics experience in commissioning and operation of radiation and air activity monitoring system at FBTR

International Nuclear Information System (INIS)

Raghunath, V.M.; Meenakshisundaram, V.; Viswanathan, S.; Bala Sundar, S.; Jose, M.T.; Suriyamurthy, N.; Ravi, T.; Subramanian, V.

2001-01-01

The Radiation and Air Activity Monitoring System (RAAMS) at Fast Breeder Test Reactor (FBTR) is meant to monitor and record the radiation and air activity levels at various potentially active areas in FBTR complex. Health Physics Group, FBTR was associated during commissioning of RAAMS in fixing the alarm settings for the monitors, their relocation and in formulating the surveillance procedures. The areas were surveyed to check for any release of activity for confirming the observed readings during operation of the reactor. In such cases, augmentation of shielding was recommended and was promptly implemented by the station management. The details of the long and fruitful experience gained by the Health Physics Group, FBTR are described in this paper. (author)

Activation of chemical biological defense mechanisms and remission of vital oxidative injury by low dose radiation

International Nuclear Information System (INIS)

Yamaoka, K.; Nomura, T.; Kojima, S.

2000-01-01

Excessive active oxygen produced in vivo by various causes is toxic. Accumulation of oxidation injuries due to excessive active causes cell and tissue injuries, inducing various pathologic conditions such as aging and carcinogenesis. On the other hand, there are chemical defense mechanisms in the body that eliminate active oxygen or repair damaged molecules, defending against resultant injury. It is interesting reports that appropriate oxidation stress activate the chemical biological defense mechanisms. In this study, to elucidate these phenomena and its mechanism by low dose radiation, we studied on the below subjects. Activation of chemical biological defense mechanisms by low dose radiation: (1) The effects radiation on lipid peroxide (LPO) levels in the organs, membrane fluidity and the superoxide dismutase (SOD) activity were examined in rats and rabbits. Rats were irradiated with low dose X-ray over their entire bodies, and rabbits inhaled vaporized radon spring water, which primarily emitted α-ray. The following results were obtained. Unlike high dose X-ray, low dose X-ray and radon inhalation both reduced LPO levels and made the state of the SH-group on membrane-bound proteins closer to that of juvenile animals, although the sensitivity to radioactivity varied depending on the age of the animals and among different organs and tissues. The SOD activity was elevated, suggesting that low dose X-ray and radon both activate the host defensive function. Those changes were particularly marked in the organs related to immune functions of the animals which received low dose X-ray, while they were particularly marked in the brain after radon inhalation. It was also found that those changes continued for longer periods after low dose X-irradiation. (2) Since SOD is an enzyme that mediates the dismutation of O 2 - to H 2 O 2 , the question as to whether the resultant H 2 O 2 is further detoxicated into H 2 O and O 2 or not must still be evaluated. Hence, we studied

Outdoor radiofrequency radiation levels in the West Bank-palestine

International Nuclear Information System (INIS)

Lahham, A.; Hammash, A.

2012-01-01

This work presents the results of exposure levels to radio frequency (RF) emission from different sources in the environment of the West Bank-Palestine. These RF emitters include FM and TV broadcasting stations and mobile phone base stations. Power densities were measured at 65 locations distributed over the West Bank area. These locations include mainly centres of the major cities. Also a 24 h activity level was investigated for a mobile phone base station to determine the maximum activity level for this kind of RF emitters. All measurements were conducted at a height of 1.7 m above ground level using hand held Narda SRM 3000 spectrum analyzer with isotropic antenna capable of collecting RF signals in the frequency band from 75 MHz to 3 GHz. The average value of power density resulted from FM radio broadcasting in all investigated locations was 0.148 μW cm -2 , from TV broadcasting was 0.007 μW cm -2 and from mobile phone base station was 0.089 μW cm -2 . The maximum total exposure evaluated at any location was 3.86 μW cm -2 . The corresponding exposure quotient calculated for this site was 0.02. This value is well below unity indicating compliance with the International Commission on non-ionising Radiation protection guidelines. Contributions from all relevant RF sources to the total exposure were evaluated and found to be ∼62 % from FM radio, 3 % for TV broadcasting and 35 % from mobile phone base stations. The average total exposure from all investigated RF sources was 0.37 μW cm -2 . (authors)

The role of the stress-activated protein kinase (SAPK/JNK) signaling pathway in radiation-induced apoptosis

International Nuclear Information System (INIS)

Verheij, M.; Ruiter, G.A.; Zerp, S.F.; Bartelink, H.; Blitterswijk, W.J. van; Fuks, Z.; Haimovitz-Friedman, A.

1998-01-01

Ionizing radiation, like a variety of other cellular stress factors, initiates apoptosis, or programmed cell death, in many cell systems. This mode of radiation-induced cell kill should be distinguished from clonogenic cell death due to unrepaired DNA damage. Ionizing radiation not only exerts its effect on the nuclear DNA, but also at the plasma membrane level where it may activate multiple signal transduction pathways. One of these pathways is the stress-activated protein kinase (SAPK) cascade which transduces death signals from the cell membrane to the nucleus. This review discusses recent evidence on the critical role of this signaling system in radiation- and stress-induced apoptosis. An improved understanding of the mechanisms involved in radiation-induced apoptosis may ultimately provide novel strategies of intervention in specific signal transduction pathways to favorably alter the therapeutic ratio in the treatment of human malignancies. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Estimation of natural radiation background level and population dose in China

International Nuclear Information System (INIS)

Pan Ziqiang

1992-01-01

The authors describe in general the natural radiation background level in China, and based on available data present an estimated annual effective dose equivalent of the population to natural radiation that is some 2.3 mSv, of which about 0.54 mSv is from original γ radiation and about 0.8 mSv from radon and its short-lived daughters

Active electromagnetic invisibility cloaking and radiation force cancellation

Science.gov (United States)

Mitri, F. G.

2018-03-01

This investigation shows that an active emitting electromagnetic (EM) Dirichlet source (i.e., with axial polarization of the electric field) in a homogeneous non-dissipative/non-absorptive medium placed near a perfectly conducting boundary can render total invisibility (i.e. zero extinction cross-section or efficiency) in addition to a radiation force cancellation on its surface. Based upon the Poynting theorem, the mathematical expression for the extinction, radiation and amplification cross-sections (or efficiencies) are derived using the partial-wave series expansion method in cylindrical coordinates. Moreover, the analysis is extended to compute the self-induced EM radiation force on the active source, resulting from the waves reflected by the boundary. The numerical results predict the generation of a zero extinction efficiency, achieving total invisibility, in addition to a radiation force cancellation which depend on the source size, the distance from the boundary and the associated EM mode order of the active source. Furthermore, an attractive EM pushing force on the active source directed toward the boundary or a repulsive pulling one pointing away from it can arise accordingly. The numerical predictions and computational results find potential applications in the design and development of EM cloaking devices, invisibility and stealth technologies.

Serum testosterone levels after external beam radiation for clinically localized prostate cancer

International Nuclear Information System (INIS)

Zagars, Gunar K.; Pollack, Alan

1997-01-01

Purpose: To determine whether serum total testosterone levels change after external beam radiation therapy for localized prostate cancer. Methods and Materials: Eighty-five men with clinically localized prostate cancer (T1-T3, N0/NX, M0) who underwent external beam radiation therapy without androgen ablation had pretreatment and 3-month posttreatment total serum testosterone levels determined by radioimmunoassay. Scattered doses to the testicles were measured with thermoluminescent dosimetry in 10 men. Results: Pretreatment serum testosterone levels ranged from 185 to 783 ng/dl, with a mean of 400 ng/dl and a median of 390 ng/dl. The coefficient of variation was 30%. Postradiation 3-month testosterone levels ranged from 163 ng/dl to 796 ng/dl, with mean and median values of 356 ng/dl and 327 ng/ml, respectively. The coefficient of variation was 34%. The 3-month value was significantly lower than the pretreatment value (Wilcoxon paired p = 0.0001). The mean absolute fall was 94 ng/dl and the mean percentage fall was 9%. Although the fall in testosterone level was statistically significant, the difference was very small quantitatively. In contrast, serum prostate-specific antigen levels fell dramatically by 3 months after radiation. Testicular scattered doses ranged from 1.84 to 2.42 Gy, with a mean of 2.07 Gy for a prostatic tumor dose of 68 Gy. Conclusions: Although significant, the fall in serum testosterone level after radiation for localized prostate cancer was small and likely of no pathophysiologic consequence. It is unlikely that scattered testicular radiation plays any significant role in the genesis of this change in testosterone level, which most likely occurs as a nonspecific stress response

Environmental radiation level, radiation anxiety, and psychological distress of non-evacuee residents in Fukushima five years after the Great East Japan Earthquake: Multilevel analyses

Directory of Open Access Journals (Sweden)

Maiko Fukasawa

2017-12-01

Full Text Available The present study aimed to clarify the associations among radiation exposure or psychological exposure to the Fukushima nuclear power plant accident (i.e., fear/anxiety immediately after the accident, current radiation anxiety, and psychological distress among non-evacuee community residents in Fukushima five years after the Great East Japan Earthquake, which occurred in March 2011. A questionnaire survey was administered to a random sample of non-evacuee community residents from 49 municipalities of Fukushima prefecture from February to April 2016, and data from 1684 respondents (34.4% were analyzed. Environmental radiation levels at the time of the accident were ascertained from survey meter data, while environmental radiation levels at the time of the survey were ascertained from monitoring post data. In the questionnaire, immediate fear/anxiety after the accident, current radiation anxiety, and psychological distress were measured using a single-item question, a 7-item scale, and K6, respectively. Multilevel linear or logistic regression models were applied to analyze the determinants of radiation anxiety and psychological distress. The findings showed that environmental radiation levels at the time of the survey were more strongly associated with radiation anxiety than radiation levels immediately after the accident. Disaster-related experiences, such as direct damage, disaster-related family stress, and fear/anxiety after the accident, and demographic characteristics (e.g., younger age, being married, low socioeconomic status were significantly associated with radiation anxiety. Environmental radiation levels at the time of the accident or survey were not significantly associated with psychological distress. Radiation anxiety largely mediated the association between fear/anxiety after the accident and psychological distress. In addition to environmental radiation levels, respondents’ radiation anxiety was affected by multiple factors

Investigation on the acceptance level of radiation exposure. Comparison of Chinese and Japanese

International Nuclear Information System (INIS)

Wu, Jin; Katoh, Kazuaki

1999-01-01

Safety standards must be determined with the contract between a society and the person concerned, i.e. the agreement in a social community. Individual understandings on the (ionizing) radiation should be proper and uniform as far as possible, just in the case. The individual acceptable radiation dose level of a constituent of a community is one of the key roles for radiation managements and also coping with radiofobia (persons who have hatred and/or allergic syndromes for the radiation). The authors have obtained information by means of questionnaires on the acceptable dose levels of the radiation for 2 groups in a community, the one is a medical science group and the other is a science-technology group in both countries, China and Japan. The annual natural radiation dose etc. are described with inquiries to preclude meaningless responses. The levels of the acceptable radiation dose are different in individuals and show wide distributions. The gap between the two acceptable dose levels for a person is narrow, i.e. the one is the minimum radiation dose that a person rejects with dread and the other is the maximum dose that a person does not have any anxiety. The Japanese science-technology group shows the significant higher dose than that of the Chinese science-technology group. The Chinese medical science group shows the significant higher dose than that of the Chinese science-technology group. The Japanese medical science group does not show the statistically significant difference from the Japanese science-technology group. A perception for the radiation exposure and safety is unexpectedly scattered from person to person even though among the high-level intellectual groups mentioned above. There is no difference on this scattering between the Japan and China. (Y. Tanaka)

Radiation cancer, safety standards and current levels of exposure

International Nuclear Information System (INIS)

Mole, R.H.

1976-01-01

Cancer can be induced by radiation in any tissue where cancer occurs naturally. The observation that antenatal diagnostic radiography causes a small but definite increase in childhood cancer is as good evidence as could be expected in support of the scientific expectation that there would be no threshold of dose for carcinogenesis. A linear relation between radiation dose and frequency of induced cancer is a necessary assumption for a system of radiological protection but is not necessarily a reasonable basis for realistic assessments of cancer risk. Indeed there are radiobiological and epidemiological reasons to the contrary. If the linear hypothesis is accepted then at the present time in the UK the routine practice of medicine is of about 2 orders of magnitude more important in causing cancer than environmental pollution by discharge of radio-activity. The acceptability of radiation safety standards for occupational exposure may be justified by comparison of radiation cancer risks with risks from fatal accidents in the safer industries. The acceptability of the corresponding standards for members of the public seems to require more public discussion of the concept of negligible risk. Emotional reactions to uncontrolled releases of radio-activity are based at least in part on a failure to appreciate the hypothesis of linearity

Ambient radiation levels in positron emission tomography/computed tomography (PET/CT) imaging center

Energy Technology Data Exchange (ETDEWEB)

Santana, Priscila do Carmo; Oliveira, Paulo Marcio Campos de; Mamede, Marcelo; Silveira, Mariana de Castro; Aguiar, Polyanna; Real, Raphaela Vila, E-mail: pridili@gmail.com [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Silva, Teogenes Augusto da [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2015-01-15

Objective: to evaluate the level of ambient radiation in a PET/CT center. Materials and methods: previously selected and calibrated TLD-100H thermoluminescent dosimeters were utilized to measure room radiation levels. During 32 days, the detectors were placed in several strategically selected points inside the PET/CT center and in adjacent buildings. After the exposure period the dosimeters were collected and processed to determine the radiation level. Results: in none of the points selected for measurements the values exceeded the radiation dose threshold for controlled area (5 mSv/ year) or free area (0.5 mSv/year) as recommended by the Brazilian regulations. Conclusion: in the present study the authors demonstrated that the whole shielding system is appropriate and, consequently, the workers are exposed to doses below the threshold established by Brazilian standards, provided the radiation protection standards are followed. (author)

IAEA standard syllabus of a course to acquire competence on ionizing radiation sources activities

International Nuclear Information System (INIS)

Antonova, M.

2004-01-01

The specialized training for Ionizing Radiation Sources (IRS) activities is conducted according to educational syllabuses developed for every job position in compliance with art. 12, (3) of new Regulation of the conditions and procedure for acquiring professional qualification and for the procedure for issuing licenses for specialized training and certificates for qualification for use of nuclear energy. A brief review of the modular structure of the standard syllabus of the Postgraduate Educational Course in Radiation Protection and the Safe Use of Radiation Sources is presented in this paper. The content and level of training for categories of persons engaged in different practices are also listed

Effect of radiation on activity of sulphate reducing bacteria

International Nuclear Information System (INIS)

Agaev, N.M.; Smorodin, A.E.; Gusejnov, M.M.

1985-01-01

The effect of γ-radiation on activity of sulphate reducing bacteria has been studied. Concentration of biogenic hydrogen, generated in the medium, is the main criterion, characterizing corrosion activity of the bacteria studied. The developed method of suppression of active development of sulfate reducing bacteria considerably reduces, and at lethal doses of γ-radiation eliminates altogether the bacteria activity and formation of the main corrosion agent-hydrogen sulphide-in the medium and that, in its turn, liquidates hydrogen sulphide corrosion

The Effect of Gamma radiation, microwave radiation, their interaction and storage on chemical composition, antinutritional factors and the activities of trypsin inhibitor and lipoxygenase of soybean seeds

Energy Technology Data Exchange (ETDEWEB)

Abdel-Rahim, E A; Abdel-Fatah, O M [Dept. of Biochem., Faculty of Agric., Cairo University. (Egypt); El-Adawy, M; Badea, M Y [Food Technol. Dept., National Center for Research and Radiation Technol., Atomic Energy Authority (Egypt)

2000-07-01

The effect of gamma radiation, microwave radiation, interaction between them; and storage of radiated soybean seeds were investigated to find out the best treatment which had to the maximum reduction of antinutrional factors (Trypsin inhibitor and lipoxygenase activities) without significant effect on the chemical constituents. The gamma rays was used at three doses of 2.5, 5.0 and 8.0 kGy, microwave radiation was at 70 level power for 2 and 4 min; and the storage of seeds was at temperature, R.H. 50-55% for six months. The data revealed that, effects of interaction treatments were more effective than the treatment with microwave or gamma radiation alone.

The Effect of Gamma radiation, microwave radiation, their interaction and storage on chemical composition, antinutritional factors and the activities of trypsin inhibitor and lipoxygenase of soybean seeds

International Nuclear Information System (INIS)

Abdel-Rahim, E.A.; Abdel-Fatah, O.M.; El-Adawy, M.; Badea, M.Y.

2000-01-01

The effect of gamma radiation, microwave radiation, interaction between them; and storage of radiated soybean seeds were investigated to find out the best treatment which had to the maximum reduction of antinutrional factors (Trypsin inhibitor and lipoxygenase activities) without significant effect on the chemical constituents. The gamma rays was used at three doses of 2.5, 5.0 and 8.0 kGy, microwave radiation was at 70 level power for 2 and 4 min; and the storage of seeds was at temperature, R.H. 50-55% for six months. The data revealed that, effects of interaction treatments were more effective than the treatment with microwave or gamma radiation alone

Radiation levels in eastern Europe

International Nuclear Information System (INIS)

Webb, G.A.M.; Simmonds, J.R.; Wilkins, B.T.

1986-01-01

Immediately after news of the accident at Chernobyl became available on 28 April, the National Radiological Protection Board (NRPB) was asked by the UK Foreign and Commonwealth Office (FCO) for an appraisal of the radiation situation on the basis of which advice would be given to embassy staff, residents in affected countries and prospective travellers. The first Swedish measurements, external gamma dose rates and, later, concentrations of atmospheric and ground radioactivity, were used to estimate the quantity of radioactivity released by means of NRPB's accident consequence code (1), MARC. Our first predictions of 29 April indicated a substantial release of the order of 10 17 - 10 18 Bq, which was expected to lead to tens of early radiation-induced deaths in the area around the site. On the basis of NRPB's recommended Emergency Reference Levels (ERL's), it was thought that there would be a need for evacuation out to 20 to 30 km and for temporary food restrictions out to a few hundred kilometres from the site. FCO accordingly decided to evacuate students from Kiev and Minsk and to advise people not to travel to the western Soviet Union or to north-east Poland unless absolutely necessary

An overview of radiation protection at national level in Greece

International Nuclear Information System (INIS)

Dimitriou, P.A.

1997-01-01

The Greek radiation protection Regulations were revised extensively and harmonized with the relevant Euratom Directives in 1991, covering almost all applications of ionizing radiation. According to the low in force, Greek Atomic Energy Commission (GAEC) is the regulatory and competent authority on radiation protection matters. Among others is responsible: for evaluating the environmental radiation, for introducing emergency plans to responsible Ministries to cope with radiation accidents or increased radioactivity levels, for issuing safety regulation concerning the operation employing ionizing radiation, performing inceptions to all installations or laboratories where radioisotopes or radiation producing machines are employed including all medical applications and issuing the certificate of compliance with the radiation protection regulations. GAEC is the governmental licensing authority for import, export, possession, use, transport and disposal of radioactive materials including fissile materials, and is also responsible for providing training and education to scientists and technical personnel on radiation protection and operates a two years postgraduate course in Medical radiation Physics in collaboration with three Greek Universities, leading to an M Sc degree.The achievements, initiatives and perceptivities of GAEC in the fields of its responsibility are discussed. Statistical data concerning the application of ionising radiation in Greece during the last five years are also presented (author)

External radiation levels in installations of nuclear technology center

International Nuclear Information System (INIS)

Maletta, Paulo Guilherme M.; Filipetto, Joao; Wakabayashi, Tetsuaki; Silva, Teogenes A. da

2005-01-01

The radiological protection is a basic activity of nuclear technology center so that can carry through its activities with security, having to be planned and executed with total effectiveness. One of the basic tools of the radiological protection is the adoption of monitoring programs, that have as objective generality to evaluate the radiological conditions of the workstation and to assure that these conditions are acceptable safe for the displayed individuals, either workers or members of the public, as established in the basic norms of radiological protection. The Centro de Desenvolvimento da Tecnologia Nuclear - CDTN, first institution in Brazil, created in 1952 to entirely dedicate the related works to the nuclear area, to own 39 building, of which they are kept the Triga Reactor, Irradiation Gamma Laboratory, Reject Laboratory, Calibration Dosemeters Laboratory and others. In such installations, radioactive materials are produced, handled, processed and stored, being necessary the levels of external radiation ambient monitoring. As part of the radioprotection plan, monitoring 63 points on strategically located in the external areas to the building of CDTN, using characterized and calibrated thermoluminescence dosemeters. This work describes the dose distribution of the points, the doses evaluation procedure and the 4 results carried through between 2001 and 2004. The data demonstrate the attendance to the level of security established in the basic norm, what it contributed for the operation licensing of to the IBAMA. (author)

Low-level radiation: a high-level concern

International Nuclear Information System (INIS)

Holden, C.

1979-01-01

The role of DOE in radiation health effects research is discussed. The possibility of conflict of interest is presented. The Mancuso episode is cited as evidence. The roles of several agencies (EPA, NRC, and OSHA) in establishing safe limits of radiation exposure are discussed

Change in catalase and peroxidase activity in rat blood in case of combined burn and radiation injury

International Nuclear Information System (INIS)

Abramova, L.P.; Simonova, L.N.

1982-01-01

The peroxidase activity of blood and catalase activity were studied in white rats, subjected to whole-body X-irradiation with the dose 129 mC/kg and burn injury (20% of body surface) of 3A-3B degree and also combined burn and radiation injury. It is established that catalase activity was decreased in all groups and at all terms of the investigation. The changes in the blood peroxide activity were of phase character and normalized only by 14th day. The peroxide activity restores to intact level only by 30th day in animals with burn and radiation injury, that testifies to heavier course of the desease and to protracted character of recovery processes

Radioprotective effect of Haberlea rhodopensis (Friv.) leaf extract on gamma-radiation-induced DNA damage, lipid peroxidation and antioxidant levels in rabbit blood.

Science.gov (United States)

Georgieva, Svetlana; Popov, Borislav; Bonev, Georgi

2013-01-01

Different concentrations of H. rhodopensis total extract (HRE; 0.03, 0.06 and 0.12 g/kg body weight) were injected im, into rabbits 2 h before collecting the blood samples. The whole blood samples were exposed in vitro to 2.0 Gy 60Co gamma-radiation. The radiation-induced changes were estimated by using the chromosome aberration test (CA) and cytokinesis blocked micronucleus assay (CBMN) in peripheral lymphocytes, and by determining the malondialdehyde levels (MDA) in blood plasma and the superoxide dismutase (SOD) and catalase (CAT) activity in erythrocytes. Radiation significantly increased the chromosome aberration and micronuclei frequencies as well as MDA levels and decreased the antioxidant enzyme activity. On the other hand, the HRE pretreatment significantly decreased the CA, MN frequencies and MDA levels and increased the SOD and CAT activity in a concentration dependent manner. The most effective was the highest concentration of HRE (0.12 g/kg body weight). The results suggest that HRE as a natural product with a nantioxidant capacity could play a modulatory role against the cellular damage induced by gamma-irradiation. The possible mechanism involved in the radioprotective potential of HRE is discussed.

Radioprotective effect of Haberlea rhodopensis (Friv.) leaf extract on γ-radiation-induced DNA damage, lipid peroxidation and antioxidant levels in rabbit blood

International Nuclear Information System (INIS)

Georgieva, Svetlana; Bonev, Georgi; Popov, Borislav

2013-01-01

Different concentrations of H. rhodopensis total extract (HRE; 0.03, 0.06 and 0.12 g/kg body weight) were injected im, into rabbits 2 h before collecting the blood samples. The whole blood samples were exposed in vitro to 2.0 Gy 60 Co γ-radiation. The radiation-induced changes were estimated by using the chromosome aberration test (CA) and cytokinesis blocked micronucleus assay (CBMN) in peripheral lymphocytes, and by determining the malondialdehyde levels (MDA) in blood plasma and the superoxide dismutase (SOD) and catalase (CAT) activity in erythrocytes. Radiation significantly increased the chromosome aberration and micronuclei frequencies as well as MDA levels and decreased the antioxidant enzyme activity. On the other hand, the HRE pretreatment significantly decreased the CA, MN frequencies and MDA levels and increased the SOD and CAT activity in a concentration dependent manner. The most effective was the highest concentration of HRE (0.12 g/kg body weight). The results suggest that HRE as a natural product with an antioxidant capacity could play a modulatory role against the cellular damage induced by γ-irradiation. The possible mechanism involved in the radioprotective potential of HRE is discussed. (author)

Solid-state radiation detectors for active personal dosimetry and radiations source tracking

International Nuclear Information System (INIS)

Talpalariu, Corneliu; Talpalariu, Jeni; Matei, Corina; Lita, Ioan; Popescu, Oana

2010-01-01

We report on the design of the readout electronics using PIN diode radiation detector of 5 mm thickness for nuclear safety and active personal dosimetry. Our effort consisted in designing and fabricating the electronics to reflect the needs of gamma radiations dosimetry and hybrids PIN diode arrays for charged particle detectors. We report results obtained during testing and characterizing the new devices in gamma fields, operating at room temperature. There were determined the energy spectrum resolution, radiation hardness and readout rate. Also, data recording methods and parallel acquisition problems from a transducer matrix are presented. (authors)

Gamma radiation treatment activates glucomoringin synthesis in Moringa oleifera

Directory of Open Access Journals (Sweden)

Tsifhiwa Ramabulana

Full Text Available Abstract Plants are a very rich source of pharmacologically relevant metabolites. However, the relative concentrations of these compounds are subject to the genetic make-up, the physiological state of the plant as well as environmental effects. Recently, metabolic perturbations through the use of abiotic stressors have proven to be a valuable strategy for increasing the levels of these compounds. Oxidative stress-associated stressors, including ionizing radiation, have also been reported to induce metabolites with various biological activities in plants. Hence, the aim of the current study was to investigate the effect of gamma radiation on the induction of purported anti-cancerous metabolites, glucomoringin and its derivatives, in Moringa oleifera Lam., Moringaceae. Here, an UHPLC-qTOF-MS-based targeted metabolic fingerprinting approach was used to evaluate the effect of gamma radiation treatment on the afore-mentioned health-beneficial secondary metabolites of M. oleifera. Following radiation, an increase in glucomoringin and three acylated derivatives was noted. As such, these molecules can be regarded as components of the inducible defense mechanism of M. oleifera as opposed to being constitutive components as it has previously been assumed. This might be an indication of a possible, yet unexplored role of moringin against the effects of oxidative stress in M. oleifera plants. The results also suggest that plants undergoing photo-oxidative stress could accumulate higher amounts of glucomoringin and related molecules.

The importance of making right knowledge about radiation popular. Activity of 'radiation education forum'

International Nuclear Information System (INIS)

Matsuura, Tatsuo; Iiri, Yuichi

2000-01-01

Radiation and radionuclides are not only indispensable in medical diagnoses and treatments, but are widely used in fundamental researches in various fields and in industry, thus contribute much to humans for elevating the quality of life. Nuclear power production is also playing an important role in saving the nonrenewable natural energy resources, without producing potentially problematic carbon dioxide. However, a majority of people has an excessive concern for radiation and radioactivity even for very minute quantities. This is due to the following three facts: (1) the first use of nuclear energy as the disastrous weapon in 1945 has resulted a profound after-effect in socio-psychological sense especially in Japan, (2) the major accidents of nuclear power plants which occurred in 1980's have been repeatedly reported in mass media with undue sensationalism, and (3) the proposition, that every ray of ionizing radiation may destroy DNA of human cells and is harmful by bringing carcinogenic or hereditary effects, has fixed as a suspicion-free common sense for general public. This proposition has its basis on the recommendation by ICRP of adopting the LNT (linear non-threshold), model even for low dose of radiations comparative with the natural radiation level. Thus the majority of people shows the syndrome of radio phobia'. Because there are so many risks other than radiation in the present day civilization, the extremely severe regulation only of radiation has many social demerits, and it is highly necessary that this situation be improved, by making the correct scientific information popular to the public. As an approach to this goal, a voluntary group, 'Radiation Education Forum', comprised of scientists, schoolteachers, journalists and citizens, has been established in 1994 in Japan, and has continued various types of activities. Because the social education has its basis on the school education, we have focussed our energy mainly for improving the education

Ambient radiation levels in positron emission tomography/computed tomography (PET/CT) imaging center

Science.gov (United States)

Santana, Priscila do Carmo; de Oliveira, Paulo Marcio Campos; Mamede, Marcelo; Silveira, Mariana de Castro; Aguiar, Polyanna; Real, Raphaela Vila; da Silva, Teógenes Augusto

2015-01-01

Objective To evaluate the level of ambient radiation in a PET/CT center. Materials and Methods Previously selected and calibrated TLD-100H thermoluminescent dosimeters were utilized to measure room radiation levels. During 32 days, the detectors were placed in several strategically selected points inside the PET/CT center and in adjacent buildings. After the exposure period the dosimeters were collected and processed to determine the radiation level. Results In none of the points selected for measurements the values exceeded the radiation dose threshold for controlled area (5 mSv/year) or free area (0.5 mSv/year) as recommended by the Brazilian regulations. Conclusion In the present study the authors demonstrated that the whole shielding system is appropriate and, consequently, the workers are exposed to doses below the threshold established by Brazilian standards, provided the radiation protection standards are followed. PMID:25798004

European activities in space radiation biology and exobiology

International Nuclear Information System (INIS)

Horneck, G.

1996-01-01

In view of the space station era, the European Space Agency has initiated a review and planning document for space life sciences. Radiation biology includes dosimetry of the radiation field and its modification by mass shielding, studies on the biological responses to radiation in space, on the potential impact of space flight environment on radiation effects, and assessing the radiation risks and establishing radiation protection guidelines. To reach a better understanding of the processes leading to the origin, evolution and distribution of life, exobiological activities include the exploration of the solar system, the collection and analysis of extraterrestrial samples and the utilization of space as a tool for testing the impact of space environment on organics and resistant life forms. (author)

Radiation therapy induced changes in male sex hormone levels in rectal cancer patients

International Nuclear Information System (INIS)

Dueland, Svein; Groenlie Guren, Marianne; Rune Olsen, Dag; Poulsen, Jan Peter; Magne Tveit, Kjell

2003-01-01

Background and purpose:To determine the effect of curative radiation therapy (46-50 Gy) on the sex hormone levels in male rectal cancer patients. Materials and methods:Twenty-five male rectal cancer patients (mean age 65 years), receiving pelvic radiation therapy (2 Gyx23-25 fractions in 5 weeks) were included. Serum testosterone, FSH and LH were determined before start of treatment, at the 10th and 25th fractions, and 4-6 weeks after completed radiotherapy. The testicular dose was determined by thermoluminescent dosimetry. Results:Five weeks of radiation therapy (46-50 Gy) resulted in a 100% increase in serum FSH, a 70% increase in LH, and a 25% reduction in testosterone levels. After treatment, 35% of the patients had serum testosterone levels below lower limit of reference. The mean radiation dose to the testicles was 8.4 Gy. A reduction in testosterone values was observed already after a mean dose of 3.3 Gy (10th fraction). Conclusion:Radiation therapy (46-50 Gy) for rectal cancer resulted in a significant increase in serum FSH and LH and a significant decrease in testosterone levels, indicating that sex hormone production is sensitive to radiation exposure in patients with a mean age of 65 years

Split energy level radiation detection

International Nuclear Information System (INIS)

Barnes, G.T.

1986-01-01

This patent describes an energy discriminating radiation detector comprising: (a) a first element comprising a first material of a kind which is preferentially responsive to penetrative radiation of a first energy range; (b) a second element comprising a second material different in kind from the first material and of a kind which is preferentially responsive to penetrative radiation of second energy range extending higher than the first energy range. The element is positioned to receive radiation which has penetrated through a portion of the first element; and (c) a filter of penetrative radiation interposed between the first and second elements

The effect of gamma radiation on the peroxides activity, colour and ascorbic acid content of papaya

International Nuclear Information System (INIS)

Asmah, R.; Nitisewojo, P.

1977-01-01

The activity of peroxidase enzyme increases during ripening with external colour used as a maturity index. An experiment indicated that 200 Krad dose level was most effective in inhibiting any increase in peroxidase activity when papaya was stored at room temperature. The doses of 25, 50 and 100 Krad level at least double the shelf life of fruit with 100 Krad was the most effective when kept in the cold. The development of yellow colour and synthesis of vitamin C is not effected. So, this preliminary study indicates that gamma radiation prolongs the shelf life of papaya when stored at cold or room temperature due to the inhibiting of the ripening process. It is also suggested that treatment of fungicides combined with gamma radiation might have an additive effect on shelf life

Alternative interpretations of statistics on health effects of low-level radiation

International Nuclear Information System (INIS)

Hamilton, L.D.

1983-01-01

Four examples of the interpretation of statistics of data on low-level radiation are reviewed: (a) genetic effects of the atomic bombs at Hiroshima and Nagasaki, (b) cancer at Rocky Flats, (c) childhood leukemia and fallout in Utah, and (d) cancer among workers at the Portsmouth Naval Shipyard. Aggregation of data, adjustment for age, and other problems related to the determination of health effects of low-level radiation are discussed. Troublesome issues related to post hoc analysis are considered

The regeneration of polluted active carbon by radiation techniques

International Nuclear Information System (INIS)

Bao Borong; Wu Minghong; Hu Longxin; Zhou Riumin; Zhu Jinliang

1998-01-01

In this paper, we investigated the regeneration of polluted active carbon from monosodium glutamate factory by combination of radiation and acid-alkali chemical techniques. The experimental results show that the polluted active carbon will be highly regenerated on the conditions of process concentration 3%, process time 0.5 hour and the adjustment process concentration 2%, time 0.5 hour, radiation dose 5kGy. As regeneration times increase, the regenerated active carbon behaves with good repetition and stable property

Role of activated carbon on micropollutans degradation by different radiation processes

Directory of Open Access Journals (Sweden)

Inmaculada Velo Gala

2015-04-01

Full Text Available The objective of this study was to analyse the influence of the presence of activated carbon on radiation processes. The triiodinated contrast medium diatrizoate was chosen as the contaminant model. We selected four commercial activated carbons and sixteen gamma radiation-modified carbons derived from these. The different advanced oxidation/reduction processes that have been studied were improved through the addition of activated carbon in the UV light and gamma radiating processes. In the UV/activated carbon process, the synergic activity of the activated carbon is enhanced in the samples with higher percentages of surface oxygen, ester/anhydride groups and carbon atoms with sp2 hybridization. Band gap determination of activated carbons revealed that they behave as semiconductor materials and, therefore, as photoactive materials in the presence of UV radiation, given that all band gap values are <4 eV. We also observed that the gamma radiation treatment reduces the band gap values of the activated carbons and that, in a single series of commercial carbons, lower band gap values correspond to higher contaminant removal rate values. We observed that the activity of the reutilized activated carbons is similar to that of the original carbons. Based on these results, we proposed that the activated carbon acts as a photocatalyst, promoting electrons of the valence band to the conduction band and increasing the generation of HO• radicals in the medium. Similarly, there was a synergic effect made by the presence of activated carbon in gamma radiation system, which favours pollutant removal. This synergic effect is independent of the textural but not the chemical characteristics of the activated carbon, observing a higher synergic activity for carbons with a higher surface content of oxygen, specifically quinone groups. We highlight that the synergic effect of the activated carbon requires adsorbent–adsorbate electrostatic interaction and is absent

Social economical and psychological considerations in conveying potential radiation risks from high level natural background radiation to the residents of Ramsar, Iran

International Nuclear Information System (INIS)

Mortazavi, S. M. J.; Ghiassi-nejad, M.

2003-01-01

X-rays and radioactivity were discovered more than 100 years ago but the need for protection against very low doses of ionizing radiation and especially different levels of natural radiation is still among the most controversial matters in radiobiology and radiation protection. According to formal reports, some areas in Ramsar, a city in northern Iran, are the inhabited areas with the highest levels of natural radiation studied so far. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy y''-1 and the highest recorded external gamma dose rates are about 130 mGy y''-1. We have previously shown that in high background radiation areas (HBRAs), cultured human lymphocytes of the inhabitants whose cumulative radiation doses were as much as 170 times more than those of a control area when subjected to 1.5 Gy challenge dose,were significantly more radioresistant compared to the residents of the control area (Mortazavi et al. 2002a,b, Mortazavi and Karam 2002, Ghiassi-Najed et al. 2002). The people who live in these areas are usually unaware of the high levels of natural radiation in their environment. Studies performed on the residents of these areas have indicated that the effective dose of the inhabitants, in some cases, is much higher than the dose limits for occupational irradiation. Considering recent policies of ICRP regarding suggesting dose limits for exposure to natural sources of ionizing including radon, it seems that the inhabitants should become familiar with the possible risks of the exposure to high levels of ionizing radiation. They should also realize that studies performed over the past years have indicated no detrimental effect. On the other hand, according to ICRP suggestions and considering the experiences in other countries, especially evacuation of the residents of contaminated areas after Chernobyl accident, setting any radiation protection regulation for the inhabitants without considering social, economic and

A passive and active microwave-vector radiative transfer (PAM-VRT) model

International Nuclear Information System (INIS)

Yang, Jun; Min, Qilong

2015-01-01

A passive and active microwave vector radiative transfer (PAM-VRT) package has been developed. This fast and accurate forward microwave model, with flexible and versatile input and output components, self-consistently and realistically simulates measurements/radiation of passive and active microwave sensors. The core PAM-VRT, microwave radiative transfer model, consists of five modules: gas absorption (two line-by-line databases and four fast models); hydrometeor property of water droplets and ice (spherical and nonspherical) particles; surface emissivity (from Community Radiative Transfer Model (CRTM)); vector radiative transfer of successive order of scattering (VSOS); and passive and active microwave simulation. The PAM-VRT package has been validated against other existing models, demonstrating good accuracy. The PAM-VRT not only can be used to simulate or assimilate measurements of existing microwave sensors, but also can be used to simulate observation results at some new microwave sensors. - Highlights: • A novel microwave vector radiative transfer model is developed. • It can simulate passive and active microwave radiative transfer simultaneously. • It can be applied to simulate measurements for different types of viewing geometry. • The accuracy of this model has been validated against other existing models

Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

Directory of Open Access Journals (Sweden)

Marie Ragon

Full Text Available BACKGROUND: The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. METHODOLOGY/PRINCIPAL FINDINGS: To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta and ascomycete fungi (Ascomycota dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. CONCLUSIONS/SIGNIFICANCE: Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in

Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels.

Science.gov (United States)

Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

2011-01-01

The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general diversity patterns, despite increased mutation levels at the single

Sunlight-Exposed Biofilm Microbial Communities Are Naturally Resistant to Chernobyl Ionizing-Radiation Levels

Science.gov (United States)

Ragon, Marie; Restoux, Gwendal; Moreira, David; Møller, Anders Pape; López-García, Purificación

2011-01-01

Background The Chernobyl accident represents a long-term experiment on the effects of exposure to ionizing radiation at the ecosystem level. Though studies of these effects on plants and animals are abundant, the study of how Chernobyl radiation levels affect prokaryotic and eukaryotic microbial communities is practically non-existent, except for a few reports on human pathogens or soil microorganisms. Environments enduring extreme desiccation and UV radiation, such as sunlight exposed biofilms could in principle select for organisms highly resistant to ionizing radiation as well. Methodology/Principal Findings To test this hypothesis, we explored the diversity of microorganisms belonging to the three domains of life by cultivation-independent approaches in biofilms developing on concrete walls or pillars in the Chernobyl area exposed to different levels of radiation, and we compared them with a similar biofilm from a non-irradiated site in Northern Ireland. Actinobacteria, Alphaproteobacteria, Bacteroidetes, Acidobacteria and Deinococcales were the most consistently detected bacterial groups, whereas green algae (Chlorophyta) and ascomycete fungi (Ascomycota) dominated within the eukaryotes. Close relatives to the most radio-resistant organisms known, including Rubrobacter species, Deinococcales and melanized ascomycete fungi were always detected. The diversity of bacteria and eukaryotes found in the most highly irradiated samples was comparable to that of less irradiated Chernobyl sites and Northern Ireland. However, the study of mutation frequencies in non-coding ITS regions versus SSU rRNA genes in members of a same actinobacterial operational taxonomic unit (OTU) present in Chernobyl samples and Northern Ireland showed a positive correlation between increased radiation and mutation rates. Conclusions/Significance Our results show that biofilm microbial communities in the most irradiated samples are comparable to non-irradiated samples in terms of general

Determination of gamma radiation lethal dose (LD50) and resveratrol cytotoxicity level in tumor cells line

International Nuclear Information System (INIS)

Magalhaes, Vanessa D.; Rogero, Sizue O.; Rogero, Jose R.; Cruz, Aurea S.

2011-01-01

Cancer is a disease with high incidence and it is considered a worldwide public health problem. Resveratrol is a polyphenol occurring naturally in a wide variety of plants according to response of ultraviolet radiation (UV) exposition or according to mechanical stress resulting of pathogens or chemical and physical agents. This polyphenol possesses a pharmacological activity of carcinogenesis inhibition in multiple levels. It also protects cells by scavenging the free radicals which are considered toxic products. These free radicals are formed of natural process of cell aging and also by incidence of ionizing radiation in the organism. Thus, resveratrol is considered as a cell radioprotector. On the other hand, in some elevated concentrations resveratrol may be considered as a radiosensitizing. The aim of this work was the determination of radiation lethal dose (LD 50 ) and also verifies the cytotoxicity level of resveratrol in tumor cells line: muco epidermoid pulmonary carcinoma cells (NCI-H292) and rhabdomyosarcoma cells (RD). The cytotoxicity test was performed by neutral red uptake assay. The results of resveratrol IC 50% in NCI-H292 cells was 192μM and in RD cells was 128μM; and RD cells gamma radiation LD 50 was 435Gy. (author)

Analysis of radiation level on dinosaur fossil in Zigong

International Nuclear Information System (INIS)

Yang Changshu; Liang Shuzhi; Fan Zhengnian.

1995-01-01

Study on radiation level of dinosaur fossil and environment in conservation zone in Zigong, Sichuan has been done. The results showed that the γ radiation dose and radioactivity strength of 232 Th and 40 K in dinosaur fossil, soil and rock in the conservation zone were within the limits of radioactive background value in Zigong. Radioactivity strength of 238 U, 226 Ra in dinosaur fossil were 26.6 and 29.2 times higher than the rock of same layer respectively

Solar Modulation of Atmospheric Cosmic Radiation:. Comparison Between In-Flight and Ground-Level Measurements

Science.gov (United States)

Iles, R. H. A.; Taylor, G. C.; Jones, J. B. L.

January 2000 saw the start of a collaborative study involving the Mullard Space Science Laboratory, Virgin Atlantic Airways, the Civil Aviation Authority and the National Physical Laboratory in a program to investigate the cosmic radiation exposure to aircrew. The study has been undertaken in view of EU Directive 96/291 (May 2000) which requires the assessment of the level of radiation exposure to aircrew. The project's aims include validation of radiation dose models and evaluation of space weather effects on atmospheric cosmic radiation levels, in particular those effects not accounted for by the models. Ground level measurements are often used as a proxy for variations in cosmic radiation dose levels at aircraft altitudes, especially during Forbush Decreases (FDs) and Solar Energetic Particle (SEP) events. Is this estimation realistic and does the ground level data accurately represent what is happening at altitude? We have investigated the effect of a FD during a flight from Hong Kong to London Heathrow on the 15th July 2000 and compared count rate and dose measurements with simultaneous variations measured at ground level. We have also compared the results with model outputs.

Collaboration of local government and experts responding to increase in environmental radiation level due to the nuclear disaster: focusing on their activities and latest radiological discussion

International Nuclear Information System (INIS)

Iimoto, T.; Nunokawa, J.; Fujii, H.; Takashima, R.; Hashimoto, M.; Fukuhara, T.; Yajima, T.; Matsuzawa, H.; Kurosawa, K.; Yanagawa, Y.; Someya, S.

2015-01-01

Activities were introduced in Kashiwa city in the Tokyo metropolitan area to correspond to the elevated environmental radiation level after the disaster of the Fukushima Daiichi nuclear power plant. These were based on a strong cooperation between local governments and experts. Ambient dose rate and radioactivity of foodstuff produced inside of the city have been monitored. Representative ambient dose rates around living environments have almost already become their original levels of the pre-accident because of the decontamination activity, natural washout and effective half-lives of radioactivity. The internal annual dose due to radioactive cesium under the policy of 'Local Production for Local Consumption' is estimated as extremely low comparing the variation range due to natural radioactivity. Systematic survey around a retention basin has been started. All of these latest monitoring data would be one of the core information for the policy making as well as a cost-benefit discussion and risk communication. (authors)

Effects of shutdown chemistry on steam generator radiation levels at Point Beach Unit 2. Interim report

International Nuclear Information System (INIS)

Kormuth, J.W.

1982-05-01

A refueling shutdown chemistry test was conducted at a PWR, Point Beach Unit 2. The objective was to yield reactor coolant chemistry data during the cooldown/shutdown process which might establish a relationship between shutdown chemistry and its effects on steam generator radiation fields. Of particular concern were the effects of the presence of hydrogen in the coolant as contrasted to an oxygenated coolant. Analysis of reactor coolant samples showed a rapid soluble release (spike) in Co-58, Co-60, and nickel caused by oxygenation of the coolant. The measurement of radioisotope specific activities indicates that the material undergoing dissolution during the shutdown originated from different sources which had varying histories of activation. The test program developed no data which would support theories that oxygenation of the coolant while the steam generators are full of water contributes to increased steam generator radiation levels

Inhibition of Protease-activated Receptor 1 Ameliorates Intestinal Radiation Mucositis in a Preclinical Rat Model

Energy Technology Data Exchange (ETDEWEB)

Wang, Junru; Kulkarni, Ashwini [Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Chintala, Madhu [Schering-Plough Research Institute, Kenilworth, New Jersey (United States); Fink, Louis M. [Nevada Cancer Institute, Las Vegas, Nevada (United States); Hauer-Jensen, Martin, E-mail: mhjensen@life.uams.edu [Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas (United States); Surgery Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas (United States)

2013-01-01

Purpose: To determine, using a specific small-molecule inhibitor of protease-activated receptor 1 (PAR1) signaling, whether the beneficial effect of thrombin inhibition on radiation enteropathy development is due to inhibition of blood clotting or to cellular (PAR1-mediated) thrombin effects. Methods and Materials: Rats underwent fractionated X-irradiation (5 Gy Multiplication-Sign 9) of a 4-cm small-bowel segment. Early radiation toxicity was evaluated in rats receiving PAR1 inhibitor (SCH602539, 0, 10, or 15 mg/kg/d) from 1 day before to 2 weeks after the end of irradiation. The effect of PAR1 inhibition on development of chronic intestinal radiation fibrosis was evaluated in animals receiving SCH602539 (0, 15, or 30 mg/kg/d) until 2 weeks after irradiation, or continuously until termination of the experiment 26 weeks after irradiation. Results: Blockade of PAR1 ameliorated early intestinal toxicity, with reduced overall intestinal radiation injury (P=.002), number of myeloperoxidase-positive (P=.03) and proliferating cell nuclear antigen-positive (P=.04) cells, and collagen III accumulation (P=.005). In contrast, there was no difference in delayed radiation enteropathy in either the 2- or 26-week administration groups. Conclusion: Pharmacological blockade of PAR1 seems to reduce early radiation mucositis but does not affect the level of delayed intestinal radiation fibrosis. Early radiation enteropathy is related to activation of cellular thrombin receptors, whereas platelet activation or fibrin formation may play a greater role in the development of delayed toxicity. Because of the favorable side-effect profile, PAR1 blockade should be further explored as a method to ameliorate acute intestinal radiation toxicity in patients undergoing radiotherapy for cancer and to protect first responders and rescue personnel in radiologic/nuclear emergencies.

The environmental radiation monitoring system and in-situ measurements for early notification and OIL (Operational Intervention Levels) calculations

Energy Technology Data Exchange (ETDEWEB)

Haquin, G.; Ne`eman, E.; Brenner, S.; Lavi, N. [Tel Aviv Univ. (Israel). Sackler School of Medicine. Inst. for Environmental Research

1997-12-31

The efficiency of the environmental radiation monitoring, low level laboratory and in-situ gamma-ray spectrometry are evaluated as the systems for early notification and for determination of dose rate in air, surface contamination and activity concentration in food during emergencies for Operational Intervention Levels (OIL) recalculation.The National Environmental Radiation Monitoring System has proved its efficiency in the early detection of unregistered radiography work. A mobile station of the network can be used for absorbed dose rate measurement during emergencies in contaminated areas. The calibrated in-situ gamma-ray spectrometry system in an open phosphate ore mine has showed the efficiency of this technique for fast and accurate determination of soil activity concentration. The calibration for an uniform depth distribution can be easily mathematically converted to an exponential depth distribution in cases of radioactive material fallout 7 refs., 3 figs., 1 tab.; e-mail: envirad at post.tau.ac.il; env{sub r}ad at netvision,net.il

Far-red enrichment and photosynthetically active radiation level influence leaf senescence in field-grown sunflower

International Nuclear Information System (INIS)

Rousseaux, M.C.; Hall, A.J.; Sánchez, R.A.

1996-01-01

Basal leaves frequently senesce before anthesis in high population density crops. This paper evaluates the hypothesis that quantitative and qualitative changes in the light environment associated with a high leaf area index (LAI) trigger leaf senescence in sunflower (Helianthus annuus L.) canopies. Mean leaf duration (LD, time from achievement of maximum leaf area) of leaf 8 was significantly (P < 0.05) reduced from 51 to 19 days as crop population density was increased from 0.47 to 4.76 plants m−2. High compared to low plant population density was associated with earlier reduction in the photosynthetically active radiation (PAR) and red/far-red ratio (R/FR) reaching the target leaf. However the changes in R/FR preceded those in PAR. When the light environment of individual leaves of isolated plants growing under field conditions was manipulated using filters and FR-reflecting mirrors, LD was positively and linearly related with the mean daily PAR (MDR) received in the FR- (no FR enrichment) treatments. FR enrichment of light reaching the abaxial surface of the leaf significantly (P < 0.05) reduced LD by 9 days at intermediate PAR levels with respect to FR-controls, but did not affect LD at the maximum PAR used in these experiments. However, when light reaching both leaf surfaces was enriched with FR, LD (for leaves receiving maximum PAR) was 13 days shorter than that of the FR- control. These results show that basal leaf senescence in sunflower is enhanced both by a decrease in PAR and by a decrease in R/FR. (author)

Vessel used in radiation counting to determine radioactivity levels

International Nuclear Information System (INIS)

Charlton, J.C.; Glover, J.S.; Shephard, B.P.

1977-01-01

This invention concerns the vessels used in radiation counting to determine radioactivity levels. These vessels prove to be particularly useful in analyses of the kind where a radioactive element or compound is separated into two phases and the radioactivity of one phase is determined. Such a vessel used in the counting of radiation includes an organic plastic substance tube appreciably cylindrical in shape whose upper end is open whilst the lower end is closed and integral with it, and an anti-radiation shield in metal or in metal reinforced plastic located at the lower end of the tube and extending along the wall of the tube up to a given height. The vessel contains a reaction area of 1 to 10 ml for holding fluid reagents [fr

Vegetative and reproductive plasticity of broccoli at three levels of incident photosynthetically active radiation

International Nuclear Information System (INIS)

Francescangeli, N.; Martí, H.R.; Sangiacomo, M.A.

2007-01-01

To study the effects of shading on the growth, development, dry matter partitioning, and plant architecture of broccoli, ‘Legacy’ hybrid plants were grown in pots in a greenhouse under black shading meshes to generate different levels of photosynthetically active radiation (PAR). The average incident PAR was 23 mol PPF m –2 d –1 under control conditions, 15.2 under a 35% mesh, and 6.7 under a 70% mesh. The air temperature was within the range 15-22°C. As shading increased so did the duration of the growth cycle and the leaf area (LA). Shading did not affect the number of leaves, although the upper ones were more erect. The stem length and the accumulated intercepted PAR (IPAR) were negatively related. Inflorescence diameter and commercial fresh weight decreased only with the 70% mesh. Shading did not affect stem dry weight (DW) but altered dry matter allocation in the root and spear. The DW of the leaves maintained an average 45.7% of the total DW despite the greater LA developed under shade. The net assimilation rate diminished with the reduction of IPAR, and the LA increased; the plant relative growth rate was therefore practically constant. With increased shading, the leaves and the stem became the dominant photosynthate sinks. The commercial fresh weight achieved with 15.2 mol photosynthetic photon flux (PPF) m –2 d –1 was equivalent to that obtained with 23 mol PPF m –2 d –1 , but the cycle was extended for 4.5 days. With 6.7 mol PPF m –2 d –1 , yield diminished because of the lower DW produced in a cycle extended by 15 days, and because more dry matter was allocated to the stem than to the spear. Based on these results, broccoli could be considered a shade-tolerant plant. (author) [es

Radiation levels in Cath Lab and occupational exposures during manual 192Ir intracoronary brachytherapy

International Nuclear Information System (INIS)

Sharma, S.D.; Shanta, A.; Tripathi, U.B.; Bhatt, B.C.

2001-01-01

Intracoronary brachytherapy is a new modality of radiation therapy and is being used to reduce the rate of restenosis after angioplasty. Clinical trials for evaluation of safety and efficacy of manually implanted 192 Ir seed ribbons are underway at various cardiology centres in India. 192 Ir emits high energy gamma rays (0.136 -1.06 MeV), which causes concern regarding safety of the personnel when these sources are manually used in the cardiac catheterization laboratory (Cath Lab) for intracoronary irradiation. Radiation levels in Cath Lab and exposures to personnel have been measured at 6 different cardiology centres in the country during 8 different clinical trials using radiation survey meter, personnel monitoring badges and pocket dosimeters. Activities of 192 Ir seed ribbons used in these clinical trials were in the range of 5.55 - 14.8 GBq. Measured radiation levels behind the mobile lead shields, at the top of lead shields, near the patient head, near the patient toes and at the main door of the Cath Lab were in the range of 2.6-20, 50-256, 385-450, 22-225 and 2-16 μSv/hr/3.7GBq, respectively. Measured effective doses to occupational workers were in range of 14-100 μSv/procedure/3.7GBq. Based on these measurements, user institutions have been advised to use lead glass mounted L-shaped mobile lead shields with proper orientation during clinical trials, avoid unwanted occupancy in the Cath Lab and around the patient during irradiation and use conveniently long forceps or tongs for implantation and removal of sources. (author)

Radiation processing activities at OGFL

International Nuclear Information System (INIS)

Sarkar, Atish

2014-01-01

CONCAST group of Industries has set up the first Radiation Processing Plant in Eastern India as 'VIKIRAN' named as Organic Green Foods Ltd., situated at Dankuni (Durgapur Highway Express) 25 km away from central Kolkata on August 21, 2004. Shri Sanjay Sureka, Managing Director of Organic Green Foods Ltd., Kolkata belongs to the famous CONCAST Group of Industries operates the largest plant of West Bengal engaged in manufacturing of Steel Industry. The facility was aimed at improving the quality of healthcare products and devices as well as Laboratory, Spice, Herbal and Ayurvedic Products of large volumes on an industrial scale. The operation of VIKIRAN for the last ten years, has unambiguously proved that both the above objectives have been fully met and now radiation sterilization has emerged as an efficient and effective industrial process. The irradiator is a panoramic wet storage class-IV type. This Facility is designed for 1000 KCi activity of source and is suitable in medium and high dose range application. VIKIRAN offers radiation sterilization service to more than 100 manufacturers

Low-level radiation: a review of current estimates of hazards to human populations

International Nuclear Information System (INIS)

Myers, D.K.

1977-12-01

Mankind has always lived with low levels of ionizing radiation from natural sources. This ionizing radiation may induce cancers in irradiated persons and genetic defects in the descendents of irradiated persons. The internationally accepted estimates of risks suggest that the numbers of cancers and genetic defects induced in the general population by natural background radiation are not more than about 1% of the numbers of cancers and genetic defects normally present in the general population. The added risks to the general public due to any prospective nuclear power program are minute compared to those from background radiation. At the maximum permissible levels of radiation exposures for occupational workers, the predicted number of fatal cancers induced would lead to a reduction in average life-span from 73.0 years to about 72.7 years. Since occupational exposures are usually much less than maximum permissible levels, the risks are correspondingly reduced. These occupational risks are comparable to those in most other industries and occupations. Some areas of uncertainty in the accepted risk estimates are discussed in detail in this review. (author)

Swedish Radiation Protection Institute: information activities

International Nuclear Information System (INIS)

Persson, Lars

2000-01-01

The purpose of SSI's Information and PR Service is to broaden public awareness of radiation and radiation risks as well as to fulfill other performance goals. SSI achieves this through its advisory, educational and informative activities. SSI publishes two external magazines, Stralskyddsnytt and SSI News. Stralskyddsnytt - which is available in Swedish only - has a circulation of 2,000 and is published four times a year. SSI News - which is in English - is published twice a year and has a circulation of about 1,800. Another important channel of communication is the web site (www.ssi.se). Taking advantage of PUSH technology, SSI also distributes, by e-mail, press releases and other important information on radiation to radiation protection professionals in Sweden. SSI continuously monitors news by subscribing to a press clipping service. SSI Training is a commercial unit within the Information and PR Service. A policy for mass media contacts exists as well as a policy for internal communication. SSI has a graphic profile. SSI has a specialized research library. (author)

Swedish radiation protection institute. Information activities

International Nuclear Information System (INIS)

Persson, Lars

1999-01-01

The purpose of SSI's information and PR Service is to broaden public awareness of radiation and radiation risks as well as to fulfil other performance goals. SSI achieves this through its advisory, educational and informative activities. SSI publishes two external magazines, Straalskyddsnytt and SSI News. Straalskyddsnytt - which is available in Swedish only - has a circulation of 2,400 and is published four times a year. SSI News - which is in English - is published twice a year and has a circulation of about 1,500. Another important channel of communication is the web site (www.ssi.se). Taking advantage of PUSH technology, SSi also distributes, by e-mail, press releases and other important information of radiation to radiation protection professionals in Sweden. SSI continuously monitors news by subscribing to a press clipping service. SSI Training is a commercial unit within the Information and PR Service. A policy for mass media contacts exists as well as a policy for internal communication. SSI has a graphic profile. SSI has a specialised research library. (au)

Radiation exposure in the young level 1 trauma patient: a retrospective review.

Science.gov (United States)

Gottschalk, Michael B; Bellaire, Laura L; Moore, Thomas

2015-01-01

Computed tomography (CT) has become an increasingly popular and powerful tool for clinicians managing trauma patients with life-threatening injuries, but the ramifications of increasing radiation burden on individual patients are not insignificant. This study examines a continuous series of 337 patients less than 40 years old admitted to a level 1 trauma center during a 4-month period. Primary outcome measures included number of scans; effective dose of radiation from radiographs and CT scans, respectively; and total effective dose from both sources over patients' hospital stays. Several variables, including hospital length of stay, initial Glasgow Coma Scale score, and Injury Severity Score, correlated with greater radiation exposure. Blunt trauma victims were more prone to higher doses than those with penetrating or combined penetrating and blunt trauma. Location and mechanism of injury were also found to correlate with radiation exposure. Trauma patients as a group are exposed to high levels of radiation from X-rays and CT scans, and CT scans contribute a very high proportion (91.3% ± 11.7%) of that radiation. Certain subgroups of patients are at a particularly high risk of exposure, and greater attention to cumulative radiation dose should be paid to patients with the above mentioned risk factors.

Radiation protection in Sudan

International Nuclear Information System (INIS)

Elamin, O.I.; Hajmusa, E.A.; Shaddad, I.A.

2001-01-01

The regulatory framework as established by the Sudan Atomic Energy Commission (SAEC) Act, promulgated in 1996, is described in the report. Three levels of responsibility in meeting radiation protection requirements are established: the Board, the Radiation Protection Technical Committee as the competent authority in the field of radiation protection, and the SAEC Department of Radiation Protection and Environmental Monitoring as the implementing technical body. The report also refers to environmental activities, patient doses in diagnostic radiology, the management of disused sources, emergency preparedness and orphan sources, and the national training activities in the radiation protection field. (author)

Activity levels of 137 Cs in mushrooms collected from the territory of Serbia and Montenegro during 2003-2008

International Nuclear Information System (INIS)

Cuculovic, A.; Momcilovic, M.; Dragovic, S.

2009-01-01

In this paper activity levels of 137 Cs in mushrooms collected from the territory of Serbia and Montenegro during 2003-2008 are presented. Results pointed out that mushrooms are good bioindicators of radioactive contamination of the environment and also that activity levels of this radionuclide depend on mushroom specie and its treatment. Due to high activity levels of 137 Cs in some mushrooms species they must be taken into consideration in the assessment of radiation burden of population, especially in highland ecosystems. (author) [sr

Assessing risks from occupational exposure to low-level radiation

International Nuclear Information System (INIS)

Gilbert, E.S.

1989-06-01

Currently, several epidemiological studies of workers who have been exposed occupationally to radiation are being conducted. These include workers in the United States, Great Britain, and Canada, involved in the production of both defense materials and nuclear power. A major reason for conducting these studies is to evaluate possible adverse health effects that may have resulted because of the radiation exposure received. The general subject of health effects resulting from low levels of radiation, including these worker studies, has attracted the attention of various news media, and has been the subject of considerable controversy. These studies provide a good illustration of certain other aspects of the statistician's role; namely, communication and adequate subject matter knowledge. A competent technical job is not sufficient if these other aspects are not fulfilled

Calmodulin-activated cyclic nucleotide phosphodiesterase from brain. Relationship of subunit structure to activity assessed by radiation inactivation

International Nuclear Information System (INIS)

Kincaid, R.L.; Kemdner, E.; Manganiello, V.C.; Osborne, J.C.; Vaughan, M.

1981-01-01

The apparent target sizes of the basal and calmodulin-dependent activities of calmodulin-activated phosphodiesterase from bovine brain were estimated using target theory analysis of data from radiation inactivation experiments. Whether crude or highly purified samples were irradiated, the following results were obtained. Low doses of radiation caused a 10 to 15% increase in basal activity, which, with further irradiation, decayed with an apparent target size of approx.60,000 daltons. Calmodulin-dependent activity decayed with an apparent target size of approx.105,000 daltons. The percentage stimulation of enzyme activity by calmodulin decreased markedly as a function of radiation dosage. These observations are consistent with results predicted by computer-assisted modeling based on the assumptions that: 1) the calmodulin-activated phosphodiesterase exists as a mixture of monomers which are fully active in the absence of calmodulin and dimers which are inactive in the absence of calmodulin; 2) in the presence of calmodulin, a dimer exhibits activity equal to that of two monomers; 3) on radiation destruction of a dimer, an active monomer is generated. This monomer-dimer hypothesis provides a plausible explanation for and definition of basal and calmodulin-dependent phosphodiesterase activity

Research status on radiation hormesis at CRIEPI

International Nuclear Information System (INIS)

Hattori, Sadao

1996-01-01

In 1982, Thomas D. Luckey, Prof. Emeritus, University of Missouri published a paper on radiation hormesis. His emphasis was on the beneficial effects of low-level radiation contributing to a healthy body, longer life, vitalization, etc. Radiation hormesis research by the Central Research Institute of Electric Power Industry in Japan was initiated on the rationale that if Luckey's claim were true, radiation management in Japan was extremely erroneous and the research institutes had to determine the truth. Obtaining many test results from some human data and various animal experiments on the health effects of low-level radiation that support the radiation hormesis hypothesis, the Central Research Institute decided to expand their research activities into a collaborative testing program with 14 universities and 2 other institutes on various subjects. The subjects in which they are now interested are as follows: 1. enhancement of molecular biological activities such as gene repair and apoptosis by low-level radiation; 2. enhancement of the immune system such as the ratio of Helper T cell/Suppressor T cell by low-level radiation; 3. rejuvenation such as cell membrane permeability, superoxide dismutase activity, and the therapy of old-age diseases such as diabetes and high blood pressure

Health and low-level radiation: turning good news into bad news.

Science.gov (United States)

Wolfe, B; Wallis, L R

1988-08-01

This paper has a dual purpose. On the one hand, congratulations are in order; the 25th Hanford Life Sciences Symposium celebrates four decades of important research at Hanford. This research has helped provide a better understanding of ionizing radiation effects on man and his environment. Researchers at Hanford and those at other locations can take pride in the fact that today we know more about the major characteristics and potential health effects of ionizing radiation than we do for any other biological hazard. Ionizing radiation's present mysteries, important as they are, involve subtleties that are difficult to explore in detail because the effects are so small relative to other health effects. It will also be a pleasure to add our tribute, along with many others, to Herb Parker, a friend, colleague, and pioneer in the radiation protection field. Building on the work of early pioneers such as Herb and those who have and will follow in their footsteps, we will develop an even broader understanding--an understanding that will clarify the effects of low-level radiation exposure, an area of knowledge about which sound explanations and predictions elude us today. The second purpose of this paper is to remind those in the radiation protection field that they have been less than successful in one of their most important tasks--that of effective communication. The task is not an easy one because the content of the message depends upon the dose. At high doses, above 1 Sv, where the deleterious effects of radiation are predictable, there is agreement on the message that must be delivered to the public: avoid it. There is no confusion in the public sector about this message. At the much lower doses resulting from beneficial activities, the message we must convey to the public is different. Unfortunately, the only message about radiation that the public seems to remember is "avoid it." We know the proper message is not being received when the medical profession resorts

Validity of the linear no-threshold (LNT) hypothesis in setting radiation protection regulations for the inhabitants in high level natural radiation areas of Ramsar, Iran

International Nuclear Information System (INIS)

Mortazavi, S.M.J.; Atefi, M.; Razi, Z.; Mortazavi Gh

2010-01-01

Some areas in Ramsar, a city in northern Iran, have long been known as inhabited areas with the highest levels of natural radiation. Despite the fact that the health effects of high doses of ionizing radiation are well documented, biological effects of above the background levels of natural radiation are still controversial and the validity of the LNT hypothesis in this area, has been criticized by many investigators around the world. The study of the health effects of high levels of natural radiation in areas such as Ramsar, help scientists to investigate the biological effects without the need for extrapolating the observations either from high doses of radiation to low dose region or from laboratory animals to humans. Considering the importance of these studies, National Radiation Protection Department (NRPD) of the Iranian Nuclear Regulatory Authority has started an integrative research project on the health effects of long-term exposure to high levels of natural radiation. This paper reviews findings of the studies conducted on the plants and humans living or laboratory animals kept in high level natural radiation areas of Ramsar. In human studies, different end points such as DNA damage, chromosome aberrations, blood cells and immunological alterations are discussed. This review comes to the conclusion that no reproducible detrimental health effect has been reported so far. In this paper the validity of LNT hypothesis in the assessment of the health effects of high levels of natural radiation is discussed. (author)

Are we at risk from level radiation - DNA repair capacity studies

International Nuclear Information System (INIS)

Riklis, E.; Kol, R.; Heimer, Y.M.

1979-01-01

A new biochemical method, based on determination of DNA repair capability, which will enable predetermination of radiation sensitivity and further - an indication of inherent sensitivity which may be expressed only in the future when a cell will be faced with a situation in which its repair capacity will have to function to its full capability was developed. Cells are treated with trioxalen (trimethylpsoralen, TMP) and near ultraviolet light (NUV), bringing about an almost complete cessation of semiconservative DNA synthesis, 99.5 to 99.8 % inhibition. This method enabled the accurate measurement of incorporation of labelled thymidine into DNA following assaults by radiation or chemicals, indicating that repair synthesis is occurring. The method has been found suitable for the following cells: human fibroblasts, human breast cancer cells, chinese hamster V-79 cells, human lymphocytes. Since the method is applicable also for lymphocytes, it will enable carrying out a world-wide interlaboratory comparative study in which the range of 'repair capacity' of 'normal healthy' humans will be established. Individuals showing no repair capacity will not be permitted to be exposed to any level of radiation above natural background. These are the persons 'at risk' from radiation, while the general public, showing normal repair capacity may be considered safe from the effects of low-level radiations. (B.G.)

Background radiation levels and medical exposure levels in Australia

International Nuclear Information System (INIS)

Webb, D.V.; Solomon, S.B.; Thomson, J.E.M.

1999-01-01

The average effective background dose received by the Australian population has been reassessed to be ∼1.5 millisievert (mSv) per year. Over half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This background is to be compared with medical radiation, primarily diagnostic, which could add half as much again to the population exposure. This paper reviews research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background and from medical use. While the latter exposure is accepted to have a social benefit, there is a need to ensure that doses are no more than necessary to provide effective diagnosis and optimal treatment. Copyright (1999) Australasian Radiation Protection Society Inc

Determination of gamma radiation lethal dose (LD{sub 50}) and resveratrol cytotoxicity level in tumor cells line

Energy Technology Data Exchange (ETDEWEB)

Magalhaes, Vanessa D.; Rogero, Sizue O.; Rogero, Jose R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Cruz, Aurea S. [Instituto Adolfo Lutz (IAL-SP) Secao de Culturas Celulares, SP (Brazil)

2011-07-01

Cancer is a disease with high incidence and it is considered a worldwide public health problem. Resveratrol is a polyphenol occurring naturally in a wide variety of plants according to response of ultraviolet radiation (UV) exposition or according to mechanical stress resulting of pathogens or chemical and physical agents. This polyphenol possesses a pharmacological activity of carcinogenesis inhibition in multiple levels. It also protects cells by scavenging the free radicals which are considered toxic products. These free radicals are formed of natural process of cell aging and also by incidence of ionizing radiation in the organism. Thus, resveratrol is considered as a cell radioprotector. On the other hand, in some elevated concentrations resveratrol may be considered as a radiosensitizing. The aim of this work was the determination of radiation lethal dose (LD{sub 50}) and also verifies the cytotoxicity level of resveratrol in tumor cells line: muco epidermoid pulmonary carcinoma cells (NCI-H292) and rhabdomyosarcoma cells (RD). The cytotoxicity test was performed by neutral red uptake assay. The results of resveratrol IC{sub 50%} in NCI-H292 cells was 192{mu}M and in RD cells was 128{mu}M; and RD cells gamma radiation LD{sub 50} was 435Gy. (author)

Conditioning of low level radioactive wastes, spent radiation sources and their transport at the interim storage building of the Institute of Nuclear Physics in Albania

International Nuclear Information System (INIS)

Qafmolla, L.

2000-01-01

Aspects of treatment and management of radioactive wastes resulting from the use of radiation sources and radioisotopes in research, medicine and industry, are described. The methods applied for the conditioning of low-level radioactive wastes and spent radiation sources are simple. Solid radioactive wastes with low-level activity, after accumulation, minimization, segregation and measurement, are burned or compressed in a simple compactor of the PGS type. Spent radiation sources are placed into 200 l drums, are cemented and conditioned. Conditioned drums from the Radiation Protection Division of the Institute of Nuclear Physics (INP), which is the responsible Institution for the treatment and management of radioactive wastes in Albania, are transported to the interim storage building of the Institute of Nuclear Physics in Tirana. Work to construct a new building for treatment and management of radioactive wastes and spent radiation sources within the territory of INP is underway. Funds have been allocated accordingly: based on the Law No. 8025 of 25.11.1995, it is the Albanian Government's responsibility to finance activities concerned with the treatment and management of radioactive wastes generating from the use of ionizing radiation in science, medicine and industry in the country. (author)

Effects of combined radiofrequency radiation exposure on levels of reactive oxygen species in neuronal cells

International Nuclear Information System (INIS)

Kang, Kyoung Ah; Lee, Hyung Chul; Lee, Je-Jung

2014-01-01

The objective of this study was to investigate the effects of the combined RF radiation (837 MHz CDMA plus 1950 MHz WCDMA) signal on levels of intracellular reactive oxygen species (ROS) in neuronal cells. Exposure of the combined RF signal was conducted at specific absorption rate values of 2 W/kg of CDMA plus 2 W/kg of WCDMA for 2 h. Co-exposure to combined RF radiation with either H 2 O 2 or menadione was also performed. The experimental exposure groups were incubator control, sham-exposed, combined RF radiation-exposed with or without either H 2 O 2 or menadione groups. The intracellular ROS level was measured by flow cytometry using the fluorescent probe dichlorofluorescein diacetate. Intracellular ROS levels were not consistently affected by combined RF radiation exposure alone in a time-dependent manner in U87, PC12 or SH-SY5Y cells. In neuronal cells exposed to combined RF radiation with either H 2 O 2 or menadione, intracellular ROS levels showed no statically significant alteration compared with exposure to menadione or H 2 O 2 alone. These findings indicate that neither combined RF radiation alone nor combined RF radiation with menadione or H 2 O 2 influences the intracellular ROS level in neuronal cells such as U87, PC12 or SH-SY5Y. (author)

Study on regeneration of activated carbon by means of electron radiation

International Nuclear Information System (INIS)

Zhu Guanghua; Arai, H.; Hosono, M.

1991-01-01

The results of regeneration of activated carbon adsorbing sodium lauryl sulfate (SLS) by 2 MeV electron radiation, and the dependence of the regeneration rate of activated carbon on the electron current intensity, the temperature of sample and the atmosphere were reported. It is shown that regeneration of activated carbon by electron radiation is full of promise

Experience in the development and practical use of working control levels for radiation safety

International Nuclear Information System (INIS)

Epishin, A.V.

1981-01-01

The experience of development and practical use of working control levels (WCL) of radiation safety in the Gorky region, is discussed. WCL are introduced by ''Radiation Safety Guides'' (RSG-76) and have great practical importance. Regional control levels of radiation safety are determined for certain types of operations implying radioactive hazard and differentiated according to the types of sources applied and types of operation. Dose rates, radioactive contamination of operating surfaces, skin, air and waste water are subject to normalization. Limits of individual radiation doses specified according to operation categories are included. 10 tables of regional WCL indices are developed [ru

The Australasian radiation protection society's position statement on risks from low levels of ionizing radiation

International Nuclear Information System (INIS)

Don, Higson; Ches, Mason; Andrew, McEwan; Peter, Burns; Riaz, Akber; Ron, Cameron; Pamela, Sykes; Joe, Young

2006-01-01

At its Annual General Meeting in 2004, the Australasian Radiation Protection Society (A.R.P.S.) set up a working group to draft a statement of the Society's position on risks from low levels of exposure to ionizing radiation. The resulting position statement was adopted by the Society at its Annual General Meeting in 2005. Its salient features are as follows: First, there is insufficient evidence to establish a dose-effect relationship for doses that are less than a few tens of milli sieverts in a year. A linear extrapolation from higher dose levels should be assumed only for the purpose of applying regulatory controls. Secondly, estimates of collective dose arising from individual doses that are less than some tens of milli sieverts in a year should not be used to predict numbers of fatal cancers. Thirdly, the risk to an individual of doses significantly less than 100 micro sieverts in a year is so small, if it exists at all, that regulatory requirements to control exposure at this level are not warranted. (authors)

The hazards of low-level radiation

International Nuclear Information System (INIS)

Blackith, R.

1979-01-01

Safety standards are questioned, particularly in relation to the risk of inducing cancer at low doses of radiation. Statements are made on the following topics: incidence of leukaemia among children around reactors, general aging effect due to radiation, leukaemia among radiation workers in a shipyard repairing nuclear submarines, official withdrawal of funds from research workers in the field of radiation hazards, discrepancies between different measurements of radiation near nuclear power plants. (U.K.)

Operator dependency of the radiation exposure in cardiac interventions: feasibility of ultra low dose levels

International Nuclear Information System (INIS)

Emre Ozpelit, Mehmet; Ercan, Ertugrul; Pekel, Nihat; Tengiz, Istemihan; Yilmaz, Akar; Ozpelit, Ebru; Ozyurtlu, Ferhat

2017-01-01

Introduction: Mean radiation exposure in invasive cardiology varies greatly between different centres and interventionists. The International Commission on Radiological Protection and the EURATOM Council stipulate that, despite reference values, 'All medical exposure for radiodiagnostic purposes shall be kept as low as reasonably achievable' (ALARA). The purpose of this study is to establish the effects of the routine application of ALARA principles and to determine operator and procedure impact on radiation exposure in interventional cardiology. Materials and methods: A total of 240 consecutive cardiac interventional procedures were analysed. Five operators performed the procedures, two of whom were working in accordance with ALARA principles (Group 1 operators) with the remaining three working in a standard manner (Group 2 operators). Radiation exposure levels of these two groups were compared. Results: Total fluoroscopy time and the number of radiographic runs were similar between groups. However, dose area product and cumulative dose were significantly lower in Group 1 when compared with Group 2. Radiation levels of Group 1 were far below even the reference levels in the literature, thus representing an ultra-low-dose radiation exposure in interventional cardiology. Conclusion: By use of simple radiation reducing techniques, ultra-low-dose radiation exposure is feasible in interventional cardiology. Achievability of such levels depends greatly on operator awareness, desire, knowledge and experience of radiation protection. (authors)

1991 implementation of As Low As Reasonably Achievable (ALARA) administrative radiation exposure levels: Experiences and lessons learned

International Nuclear Information System (INIS)

Aldridge, T.L.; Baumann, B.L.

1993-06-01

As Low As Reasonably Achievable (ALARA) radiation exposure levels were implemented on January 1, 1991, by Westinghouse Hanford Company (WHC), a prime US Department of Energy (DOE) contractor, located in Richland, Washington. This paper describes the radiation exposure levels which were implemented and the associated experiences and lessons learned. The issue of a report from the Committee on Biological Effectiveness of Ionizing Radiation in 1989 prompted DOE to re-evaluate its position on radiation exposure limits and the resulting doses received by occupational radiation workers. DOE requested that all it's contractors determine the impacts to operations from reduced radiation exposure levels

The effect of low LET (Linear Energy Transfer ionizing radiation to catalase activity of Wistar’s submandibular gland

Directory of Open Access Journals (Sweden)

Nevy Triditha Putri

2016-12-01

Full Text Available Intraoral periapical radiograph examination is the additional examination which is the most widely used in Dentistry. This radiograph examination using an x-ray ionizing radiation with low LET (Linear Energy Transfer, and may affect submandibular salivary gland. Ionizing radiation exposure can cause damage by inducing a series of changes at the molecular and cellular level. This study aimed to prove the effects of x-ray ionizing radiation with low LET towards the catalase activity of Rattus norvegicus strain Wistar’s submandibular gland. The subjects were 28 male Wistar rats and divided into 4 groups (n=7. Three groups were exposed 4, 8 and 14 times to radiation with 0.002 µSv for each exposure. The catalase activity of each rat was examined by a spectrophotometer. Data were analyzed using one-way ANOVA followed by Bonferroni test. The results showed the average of catalase activity on Wistar rat’s submandibular gland, respectively for: 0.150±0.0895 (KK, 0.1405±0.0607 (K1, 0.1228±0.0290 (K2, 0.1227±0.0556 (K3. Data showed significant differences of catalase activity between test groups, but showed not significant differences of catalase activity between each groups of Rattus norvegicus strain Wistar’s submandibular gland. In this study concluded decreased catalase activity of Rattus norvegicus strain Wistar’s submandibular gland resulting from x-rays ionizing radiation by 4 times, 8 times and 14 times exposures.

Miniature Active Space Radiation Dosimeter, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Space Micro will extend our Phase I R&D to develop a family of miniature, active space radiation dosimeters/particle counters, with a focus on biological/manned...

DNA-dependent protein kinase participates in the radiation activation of NF-kB

International Nuclear Information System (INIS)

Rosenzweig, Kenneth E.; Youmell, Matthew B.; Price, Brendan D.

1997-01-01

The NF-kB transcription factor is maintained in an inactive state by binding to the lkBa inhibitory protein. Activation requires phosphorylation and degradation of lkBa, releasing active NF-kB. NF-kB can be activated by cytokines, antigens, free radicals and X-ray irradiation. The protein kinase responsible for phosphorylation of lkBa in vivo has not been fully characterized. Here, we have examined the role of the DNA-dependent protein kinases (DNA-PK) in the radiation-activation of NF-kB. Wortmannin is an inhibitor of DNA-PK and related kinases. Exposure of SW480 cells to wortmannin inhibited the radioactivation of NF-kB DNA-binding. Analysis of lkBa levels by western blotting indicated that wortmannin blocked the radiation induced degradation of lkBa. In in vitro experiments, purified DNA-PK was able to efficiently phosphorylate lkBa, and this phosphorylation was inhibited by wortmannin. In contrast, the induction of NF-kB activity by TNFa was unaffected by wortmannin. The results suggest that DNA-PK may phosphorylate lkBa following irradiation, leading to degradation of lkBa and the release of active NF-kB. The inability of wortmannin to block TNFa activation of NF-kB indicates there may be more than one pathway for the activation of NF-kB

PERCEPTION LEVEL EVALUATION OF RADIO ELECTRONIC MEANS TO A PULSE OF ELECTROMAGNETIC RADIATION

Directory of Open Access Journals (Sweden)

2016-01-01

Full Text Available The method for evaluating the perception level of electronic means to pulsed electromagnetic radiation is consid- ered in this article. The electromagnetic wave penetration mechanism towards the elements of electronic systems and the impact on them are determined by the intensity of the radiation field on the elements of electronic systems. The impact of electromagnetic radiation pulses to the electronic systems refers to physical and analytical parameters of the relationship between exposure to pulses of electromagnetic radiation and the sample parameters of electronic systems. A physical and mathematical model of evaluating the perception level of electronic means to pulsed electromagnetic radiation is given. The developed model was based on the physics of electronics means failure which represents the description of electro- magnetic, electric and thermal processes that lead to the degradation of the original structure of the apparatus elements. The conditions that lead to the total equation electronic systems functional destruction when exposed to electromagnetic radia- tion pulses are described. The internal characteristics of the component elements that respond to the damaging effects are considered. The ratio for the power failure is determined. A thermal breakdown temperature versus pulse duration of expo- sure at various power levels is obtained. The way of evaluation the reliability of electronic systems when exposed to pulses of electromagnetic radiation as a destructive factor is obtained.

ROLE OF TAURINE ON THE LEVEL OF SOME ESSENTIAL ELEMENTS AND OXIDATIVE STRESS IN DIFFERENT TISSUES OF RATS EXPOSED TO GAMMA RADIATION

International Nuclear Information System (INIS)

ANIS, L.M.

2008-01-01

Whole body exposure to ionizing radiation induces the formation of reactive oxygen species (ROS) in the different tissues provoking oxidative damage and organ dysfunction. The present study was designed to determine the possible protective effect of taurine against gamma radiation-induced disorders in iron (Fe), copper (Cu), zinc (Zn) and magnesium (Mg) in parallel to radiation-induced oxidative stress in liver, spleen and heart tissues. Irradiated rats were whole body exposed to 6.5 Gy gamma radiations. Taurine treated irradiated rats received 250 mg taurine/kg body weight/day for 10 successive days before irradiation. Animals were sacrificed on 1 st , 7 th and 14 th days after irradiation. The results obtained demonstrated significant increases in Fe, Cu, Zn and Mg levels in the liver. Significant increases of Fe and Cu and significant decrease of Zn and non-significant changes in Mg were observed in the spleen. Heart tissues showed significant decrease in the level of iron and non-significant changes in the levels of Cu, Zn and Mg. Alterations in the levels of essential elements were associated with oxidative stress. Significant decreases of SOD and CAT activities along with significant increase of TBARS levels were recorded in the different tissues after irradiation. Taurine administration pre-irradiation has significantly attenuated the radiation-induced oxidative stress and alteration in the levels of essential elements. It could be concluded that taurine might protect from oxidative damage induced by gamma irradiation

Comprehensive Approach for Monitoring and Analyzing the Activity Concentration Level of PET Isotopes

International Nuclear Information System (INIS)

Osovizky, A.; Paran, J.; Ankry, N.; Vulasky, E.; Ashkenazi, B.; Tal, N.; Dolev, E.; Gonen, E.

2004-01-01

A comprehensive approach for measuring and analyzing low concentration levels of positron emitter isotopes is introduced. The solution is based on a Continuous Air Monitoring Sampler (CAMS), Stack Monitoring System (SMS) and software package. Positron Emission Tomography (PET) is a major tool for both, biochemical research and non-invasive diagnostics for medicine imaging. The PET method utilizes short half life β + radioisotopes that are produced in cyclotron sites built especially for this purpose. The growing need for β + isotopes brought about a commonly wide use of cyclotrons next to populated areas. Isotopes production involves two possible radiation hazards deriving from the activity concentration; one refers to the nearby population by the activity released through the ventilation system and the other refers to the personnel working in the nuclear facility. A comprehensive system providing solution for both radiation hazards is introduced in this work

Research for Actively Reducing Infrared Radiation by Thermoelectric Refrigerator

Energy Technology Data Exchange (ETDEWEB)

Kim, Hoon; Kim, Kyomin; Kim, Woochul [Yonsei Univ., Seoul (Korea, Republic of)

2017-03-15

We introduced a technology for reducing infrared radiation through the active cooling of hot surfaces by using a thermoelectric refrigerator. Certain surfaces were heated by aerodynamic heating, and the heat generation processes are proposed here. We calculated the temperatures and radiations from surfaces, while using thermoelectric refrigerators to cool the surfaces. The results showed that the contrast between the radiations of certain surfaces and the ambient environments can be removed using thermoelectric refrigerators.

IRPA's contribution to E and T activities for radiation protection professionals

International Nuclear Information System (INIS)

Gallego, E.; Hefner, A.

2009-01-01

The International Radiation Protection Association (IRPA) promotes excellence in the practice of radiation protection through national and regional Associate Societies for radiation protection professionals. IRPA has recently prepared and E and T Plan structured around three main lines: the cooperation with international and regional organizations dealing with E and T in Radiation Protection; the internal stimulation of E and T by organizing discussion forums during IRPA Congresses; and the stimulation and support to the organization of E and T activities either by IRPA or by its Associate Societies. The main innovations are in the possibility of undertaking common activities by two or more Associate Societies; the promotion of E and T networks sharing language or regional proximity; and the emergence of activities to attract young generations to the profession. (authors)

Synoptic Traveling Weather Systems on Mars: Effects of Radiatively-Active Water Ice Clouds

Science.gov (United States)

Hollingsworth, Jeffery; Kahre, Melinda; Haberle, Robert; Urata, Richard

2017-01-01

Atmospheric aerosols on Mars are critical in determining the nature of its thermal structure, its large-scale circulation, and hence the overall climate of the planet. We conduct multi-annual simulations with the latest version of the NASA Ames Mars global climate model (GCM), gcm2.3+, that includes a modernized radiative-transfer package and complex water-ice cloud microphysics package which permit radiative effects and interactions of suspended atmospheric aerosols (e.g., water ice clouds, water vapor, dust, and mutual interactions) to influence the net diabatic heating. Results indicate that radiatively active water ice clouds profoundly affect the seasonal and annual mean climate. The mean thermal structure and balanced circulation patterns are strongly modified near the surface and aloft. Warming of the subtropical atmosphere at altitude and cooling of the high latitude atmosphere at low levels takes place, which increases the mean pole-to-equator temperature contrast (i.e., "baroclinicity"). With radiatively active water ice clouds (RAC) compared to radiatively inert water ice clouds (nonRAC), significant changes in the intensity of the mean state and forced stationary Rossby modes occur, both of which affect the vigor and intensity of traveling, synoptic period weather systems.Such weather systems not only act as key agents in the transport of heat and momentum beyond the extent of the Hadley circulation, but also the transport of trace species such as water vapor, water ice-clouds, dust and others. The northern hemisphere (NH) forced Rossby waves and resultant wave train are augmented in the RAC case: the modes are more intense and the wave train is shifted equatorward. Significant changes also occur within the subtropics and tropics. The Rossby wave train sets up, combined with the traveling synoptic period weather systems (i.e., cyclones and anticyclones), the geographic extent of storm zones (or storm tracks) within the NH. A variety of circulation

Activities of RADA in promotion of radiation applications

International Nuclear Information System (INIS)

Tanase, M.; Funayama, Y.; Tanaka, O.

2007-01-01

Radiation Application Development Association (RADA) was established to promote the applications of radiation in 1968. Among the activities of RADA, we have five works directly to promote the application of radiation to the public. One of them is to publish a quarterly journal 'Radiation and Industries' which carries comprehensive articles on timely topics of radiation-based applications, patent information etc. And also RADA organizes the Radiation Process Symposium, which has been held every other year strictly, for exchange of information on radiation applications. The symposium started in 1985, where researchers and engineers in various and wide fields have been discussed on the radiation applications to industries. As the third, RADA distributes beautiful ornaments, which were produced by gamma-ray irradiation of crystals, glass and pearls, to promote better understanding of radiation. We also have taken charge of two businesses contracted with the Ministry of Education, Culture, Sports, Science and Technology (MEXT). One is to hold seminars on radiation and nuclear energy for teachers of primary, junior high and senior high schools to enhance their understanding about radiation and nuclear energy, and to facilitate the use in their classrooms of such knowledge concerning energy, environment and their effects on our lives. The other is to facilitate the transfer of technologies of radiation application in the realms of industry, agriculture, medical treatment, etc. through dispatching of experts, releasing data on radiation applications, and organizing technical seminars. Recently, we arranged an opportunity to use neutrons from research reactors through trial experiments for transferring the technology to industries. (author)

Level of terrestrial gamma radiation and doses to population in Jiangsu province

International Nuclear Information System (INIS)

1985-01-01

In this paper the results of investigation of terrestrial gamma radiation level in Jiangsu Province are reported and the population doses due to this radiation are estimated. The sketch map of the geographical distribution of the terrestrial gamma radiation level is given. In this investigation FD-71 portable scintillation counters and RSS-111 high pressure ionization chambers were used. The results showed that the terrestrial gamma absorbed dose rates in air for indoors and outdoors were 10.7 x 10 -8 Gy/h and 6.5 x 10 -8 Gy/h (weighted values) respectively. The indoors-to-outdoors ratio was 1.65. The total (indoor plus outdoor) annual effective dose equivalent from terrestrial gamma radiation, averaged over the population in this province, was 6.0 x 10 -4 Sv. The collective annual effective dose equivalent was 3.6 x 10 4 man.Sv. Therefore, the absorbed dose to population in Jiangsu Province is in the range of the normal background

Investigation of environmental activity levels of bone-coal mining area in five provinces

International Nuclear Information System (INIS)

Ye Jida; Wu Zongmei; Kong Lingli; Shi Jinhua; Li Ying; Jiang Shan; Zhang Liang

2005-01-01

During 1991-1993, the activity levels of the bone-coal mines were investigated in Zhejiang, Hubei, Hunan, Jiangxi and Anhui Province, respectively, where the reserve of bone-coal is about 90% of our country's total reserve. The average of γ radiation dose rate level measured for bone-coal, bone-coal cinder (BCC) and bone-coal cinder brick (BCCB) in these provinces is about 500 nGy/h, 400 nGy/h and 700 nGy/h respectively, while that for fields, roads and houses made of BCCB in corresponding regions of these provinces is about 200 nGy/h, 260 nGy/h and 300 nGy/h respectively. It is shown that the environmental activity level of bone-coal mining area is about 3 times higher than the reference spots. (authors)

Radiation levels in samples of dicalcium phosphate (DCP) and bovine and poultry rations by gamma-ray spectrometry

International Nuclear Information System (INIS)

Luz Filho, Isaias Venancio da; Scheibel, Viviane; Appoloni, Carlos Roberto

2009-01-01

The objective of the present work is to determine the radiation levels found in bovine rations and in the dicalcium phosphate (DCP) feed supplement. Knowledge of the radiation levels in samples of rations and DCP for cattle is important, because they are directly and indirectly-part of the human diet. In order to obtain this data, gamma-ray spectrometry technique was used, employing a HPGe detector of 66% of relative efficiency, with an energy resolution of 2.03 KeV for the 60 Co 1332.46 KeV line. The radioactive activity of the radionuclides 40 K, 137 Cs, 238 U, 232 Th and its respective decay series was measured. The accommodation recipient of the samples was a Marinelli beaker of 1 L. The 238 U series activities were calculated through 214 Pb and 214 Bi activities, and the 232 Th series' activity was calculated through the 228 Ac, 212 Pb, 212 Bi and 208 Tl values. The DCP samples and the rations measured in this work were produced in Londrina city, Brazil, in the second semester of 2007. Among the rations, the largest 40 K and 228 Ra activities were found in the ration sample for milk cattle, 402 ± 14 and 1.71 ± 0.10 Bq/kg, respectively. The ration for beef cattle yielded the largest activity for 226 Ra, 1.51 + 0.93 Bq/kg. In the DCP sample, the activities for the 238 U, 40 K and 232 Th were respectively 83 ± 26; 46.6 ± 2.8 and 7.79 ± 0.70 Bq/kg. The MDA values for 137 Cs varied from 0.037 to 0.29 Bq/kg. (author)

Radiation-induced bilateral cystic frontal lobe necroses demonstrating a fluid-blood level; Case report

Energy Technology Data Exchange (ETDEWEB)

Mineura, Katsuyoshi; Sasajima, Toshio; Kowada, Masayoshi [Akita Univ. (Japan). School of Medicine; Ogawa, Toshihide

1992-02-01

A 41-year-old male developed radiation-induced bilateral cystic frontal lobe necroses after irradiation for an olfactory neuroblastoma. Computed tomography (CT) and magnetic resonance (MR) imaging revealed the lesions, one containing a fluid-blood level on CT scans and niveau formation on MR images. It was proved to be a coagulated hematoma within the cyst at surgery. Such a fluid-blood level in a radiation-induced cyst has never been reported, although hemorrhage frequently accompanies delayed radiation necrosis. Positron emission tomography with multiple tracers may be useful in differentiating cerebral radiation necrosis from tumor recurrence, because of absence of abnormal tracer accumulation. (author).

The importance of making right knowledge about radiation popular. Activity of 'radiation education forum'

Energy Technology Data Exchange (ETDEWEB)

Matsuura, Tatsuo; Iiri, Yuichi [Radiation Education Forum, Tokyo (Japan)

2000-05-01

Radiation and radionuclides are not only indispensable in medical diagnoses and treatments, but are widely used in fundamental researches in various fields and in industry, thus contribute much to humans for elevating the quality of life. Nuclear power production is also playing an important role in saving the nonrenewable natural energy resources, without producing potentially problematic carbon dioxide. However, a majority of people has an excessive concern for radiation and radioactivity even for very minute quantities. This is due to the following three facts: (1) the first use of nuclear energy as the disastrous weapon in 1945 has resulted a profound after-effect in socio-psychological sense especially in Japan, (2) the major accidents of nuclear power plants which occurred in 1980's have been repeatedly reported in mass media with undue sensationalism, and (3) the proposition, that every ray of ionizing radiation may destroy DNA of human cells and is harmful by bringing carcinogenic or hereditary effects, has fixed as a suspicion-free common sense for general public. This proposition has its basis on the recommendation by ICRP of adopting the LNT (linear non-threshold), model even for low dose of radiations comparative with the natural radiation level. Thus the majority of people shows the syndrome of radio phobia'. Because there are so many risks other than radiation in the present day civilization, the extremely severe regulation only of radiation has many social demerits, and it is highly necessary that this situation be improved, by making the correct scientific information popular to the public. As an approach to this goal, a voluntary group, 'Radiation Education Forum', comprised of scientists, schoolteachers, journalists and citizens, has been established in 1994 in Japan, and has continued various types of activities. Because the social education has its basis on the school education, we have focussed our energy mainly for

Concurrent Transient Activation of Wnt/{beta}-Catenin Pathway Prevents Radiation Damage to Salivary Glands

Energy Technology Data Exchange (ETDEWEB)

Hai Bo; Yang Zhenhua; Shangguan Lei; Zhao Yanqiu [Institute for Regenerative Medicine, Scott and White Hospital, Molecular and Cellular Medicine Department, Texas A and M Health Science Center, Temple, Texas (United States); Boyer, Arthur [Department of Radiology, Scott and White Hospital, Temple, Texas (United States); Liu, Fei, E-mail: fliu@medicine.tamhsc.edu [Institute for Regenerative Medicine, Scott and White Hospital, Molecular and Cellular Medicine Department, Texas A and M Health Science Center, Temple, Texas (United States)

2012-05-01

Purpose: Many head and neck cancer survivors treated with radiotherapy suffer from permanent impairment of their salivary gland function, for which few effective prevention or treatment options are available. This study explored the potential of transient activation of Wnt/{beta}-catenin signaling in preventing radiation damage to salivary glands in a preclinical model. Methods and Materials: Wnt reporter transgenic mice were exposed to 15 Gy single-dose radiation in the head and neck area to evaluate the effects of radiation on Wnt activity in salivary glands. Transient Wnt1 overexpression in basal epithelia was induced in inducible Wnt1 transgenic mice before together with, after, or without local radiation, and then saliva flow rate, histology, apoptosis, proliferation, stem cell activity, and mRNA expression were evaluated. Results: Radiation damage did not significantly affect activity of Wnt/{beta}-catenin pathway as physical damage did. Transient expression of Wnt1 in basal epithelia significantly activated the Wnt/{beta}-catenin pathway in submandibular glands of male mice but not in those of females. Concurrent transient activation of the Wnt pathway prevented chronic salivary gland dysfunction following radiation by suppressing apoptosis and preserving functional salivary stem/progenitor cells. In contrast, Wnt activation 3 days before or after irradiation did not show significant beneficial effects, mainly due to failure to inhibit acute apoptosis after radiation. Excessive Wnt activation before radiation failed to inhibit apoptosis, likely due to extensive induction of mitosis and up-regulation of proapoptosis gene PUMA while that after radiation might miss the critical treatment window. Conclusion: These results suggest that concurrent transient activation of the Wnt/{beta}-catenin pathway could prevent radiation-induced salivary gland dysfunction.

Concurrent Transient Activation of Wnt/β-Catenin Pathway Prevents Radiation Damage to Salivary Glands

International Nuclear Information System (INIS)

Hai Bo; Yang Zhenhua; Shangguan Lei; Zhao Yanqiu; Boyer, Arthur; Liu, Fei

2012-01-01

Purpose: Many head and neck cancer survivors treated with radiotherapy suffer from permanent impairment of their salivary gland function, for which few effective prevention or treatment options are available. This study explored the potential of transient activation of Wnt/β-catenin signaling in preventing radiation damage to salivary glands in a preclinical model. Methods and Materials: Wnt reporter transgenic mice were exposed to 15 Gy single-dose radiation in the head and neck area to evaluate the effects of radiation on Wnt activity in salivary glands. Transient Wnt1 overexpression in basal epithelia was induced in inducible Wnt1 transgenic mice before together with, after, or without local radiation, and then saliva flow rate, histology, apoptosis, proliferation, stem cell activity, and mRNA expression were evaluated. Results: Radiation damage did not significantly affect activity of Wnt/β-catenin pathway as physical damage did. Transient expression of Wnt1 in basal epithelia significantly activated the Wnt/β-catenin pathway in submandibular glands of male mice but not in those of females. Concurrent transient activation of the Wnt pathway prevented chronic salivary gland dysfunction following radiation by suppressing apoptosis and preserving functional salivary stem/progenitor cells. In contrast, Wnt activation 3 days before or after irradiation did not show significant beneficial effects, mainly due to failure to inhibit acute apoptosis after radiation. Excessive Wnt activation before radiation failed to inhibit apoptosis, likely due to extensive induction of mitosis and up-regulation of proapoptosis gene PUMA while that after radiation might miss the critical treatment window. Conclusion: These results suggest that concurrent transient activation of the Wnt/β-catenin pathway could prevent radiation-induced salivary gland dysfunction.

Impact of low-level radiation with special reference to tritium in environment

International Nuclear Information System (INIS)

Bhatia, A.L.

2005-01-01

Radiation is invisible, but exists in various types, in the form of particles and/or energy bundles. The effects of low-level radiation seem very abstract since these can not be perceived by our sensory organs. The increase in natural background radiation from various inadvertent sources like tritium has the prospect of altering the entire scenario of billions of years' slow and steady biogenetic evolution. Mankind, by developing atomic technologies, is unleashing forces which it does understand but not beyond experimental findings. There is no wise sorcerer who can undo the damage we are causing. Tritium is a radioactive form of hydrogen that is produced in the reactor core. The released tritium replaces hydrogen in water. Tritium in water when gets ingested, causes continuos internal low-level beta radiation exposure over a long period. Proposed presentation will focus on the possible long term damage caused by its low-level exposure is dependent on the length of duration living tissue spends in the radiation field, not on the relative radiation field strength. As internal radiation pulses never stop, impact is continuous by the ambient radiation atmosphere. There is no chance to heal at the molecular level, except small chances of DNA repair since the organically bound tritium has greater severe influence with the slow turnover. Though the situation needs not be alarming with tritium, the studies on radiation damage on various parameters have given evidence of two compartments of radiation damage; the reparable or potentially lethal and the irreparable or lethal. With emerging new reports on the stochastic effects, those for which the probability, rather than the severity of an effect from tritium occurring as a function of dose also can not be ruled out. Biotoxicity of tritium in the form of induction of cancer, hereditary effects, teratogenesis and life shortening really needs an exhaustive investigation and warrants careful evaluation. However, a positive

Report on our activities to spread knowledge about radiation in Musashi Institute of Technology

International Nuclear Information System (INIS)

Okada, Yukiko

2007-01-01

In Musashi Institute of Technology, radiation knowledge spread activities are performed twice per year. One is 'the science experience classroom which children enjoy.' Another is 'the open school which studies atomic power'. The writer participated in the 'life and radiation' project as a WEN member, and has performed the radiation knowledge spread activities to a citizen. In this paper, these activities are introduced and the necessity and problem of radiation knowledge spread activities are considered. (author)

Radiation level survey of a mobile phone base station

International Nuclear Information System (INIS)

Campos, M.C.; Schaffer, S.R.

2006-01-01

Electromagnetic field (E.M.F.) evaluations were carried out in the surroundings of a roof-top mobile-phone radio-base station (R.B.S.). Four of its sector-panel antennas are installed on two parallel vertical masts, each supporting two panels in a vertical collinear-array. The geometry is such that the vertical plane containing both masts is about 10 meters distant and parallel to the backside of an educational institution. This proximity provoked great anxiety among the local community members regarding potential health hazards.1. Introduction: To keep up with the expansion of the mobile-phone services, the number of Radio-Base Stations (R.B.S.) installations is increasing tremendously in Brazil. Efficient control and radiation monitoring to assess R.B.S. compliance to existing regulations are still lacking and particularly in big cities, clearly non - compliant R.B.S. can be seen which represent potentially hazardous E.M.F. sources to the nearby population. This first survey of an irregular R.B.S. revealed significant E-field strengths outside, as well as inside a classroom of an educational building where an usually prolonged stay is necessary. These results confirm that this problem deserves further attention, moreover, if one considers that public and occupational exposure limits set by I.C.N.I.R.P. (also adopted in Brazil) are exclusively based on the immediate thermal effects of acute exposure, disregarding any potential health risk from prolonged exposure to lower level radiation. Research activities focusing on quantitative aspects of electromagnetic radiation from R.B.S., as well as on biological and adverse health effects are still at a very incipient level, urging for immediate actions to improve this scenario in our country. 2. Material, methods and results Measurements were carried out with a broadband field strength monitor, E.M.R.-300 (W and G) coupled to an isotropic E-field probe (100 khz to 3 GHz). Preliminary measurements helped locating

The assessment of risks from exposure to low-levels of ionizing radiation

International Nuclear Information System (INIS)

Gilbert, E.S.

1992-06-01

This report is concerned with risk assessments for human populations receiving low level radiation doses; workers routinely exposed to radiation, Japanese victims of nuclear bombs, and the general public are all considered. Topics covered include risk estimates for cancer, mortality rates, risk estimates for nuclear site workers, and dosimetry

Natural radiation external exposures levels in Chilean Sub-Antarctic and country stations

International Nuclear Information System (INIS)

Stuardo, E.

1988-01-01

Since 1983 gamma exposures levels, at 1,5 m above the soil are being investigated using TLD detectors. A network of 12 stations have been established from ARICA (18 deg 20' S latitude) in Northern Chile to YELCHO (64 deg 52' S latitude) in Antartic territory. One year monitoring period was used at Antartic stations and a four months period in the country. The main subject of this study is to assess the average background radiation levels along the territory which is relevant to get a reference level and specially an estimate of the average natural radiation contribution to the population dose in Southern Chile

[Nanometer scale exciton spectroscopy and photochemistry: Dynamic imaging of DNA structure-activity relations and radiation signatures

International Nuclear Information System (INIS)

1992-01-01

Our aim is to investigate, on the molecular level at a spatially resolved mode of operation, structure-activity relations of DNA and their sensitivity to ionizing radiation. This entails in-vitro (and later in-vivo) ultra-resolved microscopy, spectroscopy and chemical sensing, with non-destructive probing

Ambient radioactivity levels and radiation doses. Annual report 2014; Umweltradioaktivitaet und Strahlenbelastung. Jahresbericht 2014

Energy Technology Data Exchange (ETDEWEB)

Trugenberger-Schnabel, Angela; Loebke-Reinl, Angelika; Peter, Josef (comps.) [Bundesamt fuer Strahlenschutz, Salzgitter (Germany)

2016-08-15

The annual report 2014 on ambient radioactivity levels and radiation doses covers the following topics: (1) Actual data and their evaluation: natural environmental radioactivity, artificial environmental radioactivity, occupational radiation exposure, radiation exposures from medical applications, handling of radioactive materials and sources of ionizing radiation, non-ionizing radiation. (2) Fundamentals and general information: legal basis and explanations, basic information on natural environmental radioactivity, basic information on artificial radioactivity in the environment, basic information on occupational radiation exposure, basic information on radiation exposures from medical applications, basic information on the handling of radioactive materials and sources of ionizing radiation, basic information on non-ionizing radiation. (3) Tables.

High level natural radiation areas with special regard to Ramsar

International Nuclear Information System (INIS)

Sohrabi, M.

1993-01-01

The studies of high level natural radiation areas (HLNRAs) around the world are of great importance for determination of risks due to long-term low-level whole body exposures of public. Many areas of the world possess HLNRAs the number of which depends on the criteria defined. Detailed radiological studies have been carried out in some HLNRAs the results of which have been reported at least in three international conferences. Among the HLNRAs, Ramsar has so far the highest level of natural radiation in some areas where radiological studies have been of concern. A program was established for Ramsar and its HLNRAs to study indoor and outdoor gamma exposures and external and internal doses of the inhabitants, 226 Ra content of public water supplies and hot springs, of food stuffs, etc., 222 Rn levels measured in 473 rooms of near 350 houses, 16 schools and 89 rooms and many locations of old and new Ramsar Hotels in different seasons, cytogenetic effects on inhabitants of Talesh Mahalleh, the highest radiation area, compared to that of a control area and radiological parameters of a house with a high potential for internal and external exposures of the inhabitants. It was concluded that the epidemiological studies in a number of countries did not show any evidence of increased health detriment in HLNRAs compared to control groups. In this paper, the conclusions drawn from studies in some HLNRAs around the world in particular Ramsar are discussed. (author). 20 refs, 2 figs, 1 tab

Collaboration of local governments and experts responding to the increase of the environmental radiation level secondary to the nuclear accident: a unique activity to relieve residents' anxiety

International Nuclear Information System (INIS)

Fujii, H.; Hamamichi, S.; Iimoto, T.; Tsuzuki, T.; Iiizumi, S.; Someya, S.; Kessler, M.M.

2015-01-01

After the Fukushima nuclear power plant accident, 'hot spots' were found in Tokatsu area in Chiba prefecture. Although ambient radiation dose in this area was too low to harm residents' health, local residents were particularly worried about possible adverse effects from exposure to radiation. To avoid unnecessary panic reactions in the public, local governments in Tokatsu area collaborated with radiation specialists and conducted activities to provide local residents with accurate information on health effects from radiation. In addition to these activities, the authors offered one-to-one consultations with a radiologist for parents of small children and expecting mothers. They herein report this unique attempt, focusing on parents' anxiety and the age of their children. Taken together, this unique collaborative activity between local government and experts would be one of the procedures to relieve residents' anxiety. (authors)

Investigation on the acceptance level of radiation exposure. Comparison of Chinese and Japanese

International Nuclear Information System (INIS)

Wu, Jin; Katoh, Kazuaki

1999-01-01

Radiation has helped to develop our culture and civilization, both of material and of spiritual, and without doubt it is useful to develop our civilization further and to enrich our future life. On the other hand, we cannot help avoiding to live with some by-product radiation of 'advanced civilization' in addition. Thus we must associate with radiation even if we like it or not. To our understanding, safety standard or criteria of safety control is nothing but a contract of the body concerned with the society. In order to make this contract rigorously, it is required for both sides to have adequately enough knowledge and data on the methodology of treating the matter. In such societies, people's acceptable levels to radiation exposure would not be widely distributed. Unification of the wills of the society is absolutely necessary to establish such a contact or develop the philosophy on radiation safety. Hence, we have tried to investigate the acceptable levels of people to radiation exposure. Two kinds of levels, upper limit of the acceptable dose for instantaneous whole body exposure, Lu, and lowest of the dose caring in mind, Ll, were set for inquiry. In this presentation, some results of our survey to both Chinese and Japanese professionals in the fields of science-technology and medical science are reported. Similarly to the previous study by Katoh, in 1989 or so, the distribution of these two levels were very broad and the band widths between the two levels, Lu and Ll, were quite narrow. The former seems reveal the variety of individual's sense of value. Moreover, it was found that, two levels, Lu and Ll, were significantly higher (p<0.05, p<0.005) in Japanese to in Chinese in science/engineering group, while in medical group, the two levels were higher apparently in Japanese than in Chinese, but no statistically significant difference was observed. Moreover, in medical group, Lu and Ll showed higher values than those in science-technology group for the

Radiation sources, radiation environment and risk level at Dubna

International Nuclear Information System (INIS)

Komochkov, M.M.

1991-01-01

The overall information about ionizing radiation sources, which form radiation environment and risk at Dubna, is introduced. Systematization of the measurement results is performed on the basis of the effective dose and losses of life expectancy. The contribution of different sources to total harm of Dubna inhabitants has been revealed. JINR sources carry in ∼ 4% from the total effective dose of natural and medicine radiation sources; the harm from them is much less than the harm from cigarette smoking. 18 refs.; 2 tabs

1999-2003 Shortwave Characterizations of Earth Radiation Budget Satellite (ERBS)/Earth Radiation Budget Experiment (ERBE) Broadband Active Cavity Radiometer Sensors

Science.gov (United States)

Lee, Robert B., III; Smith, George L.; Wong, Takmeng

2008-01-01

From October 1984 through May 2005, the NASA Earth Radiation Budget Satellite (ERBS/ )/Earth Radiation Budget Experiment (ERBE)ERBE nonscanning active cavity radiometers (ACR) were used to monitor long-term changes in the earth radiation budget components of the incoming total solar irradiance (TSI), earth-reflected TSI, and earth-emitted outgoing longwave radiation (OLR). From September1984 through September 1999, using on-board calibration systems, the ERBS/ERBE ACR sensor response changes, in gains and offsets, were determined from on-orbit calibration sources and from direct observations of the incoming TSI through calibration solar ports at measurement precision levels approaching 0.5 W/sq m , at satellite altitudes. On October 6, 1999, the onboard radiometer calibration system elevation drive failed. Thereafter, special spacecraft maneuvers were performed to observe cold space and the sun in order to define the post-September 1999 geometry of the radiometer measurements, and to determine the October 1999-September 2003 ERBS sensor response changes. Analyses of these special solar and cold space observations indicate that the radiometers were pointing approximately 16 degrees away from the spacecraft nadir and on the anti-solar side of the spacecraft. The special observations indicated that the radiometers responses were stable at precision levels approaching 0.5 W/sq m . In this paper, the measurement geometry determinations and the determinations of the radiometers gain and offset are presented, which will permit the accurate processing of the October 1999 through September 2003 ERBE data products at satellite and top-of-the-atmosphere altitudes.

Radiation therapists' perceptions of the minimum level of experience required to perform portal image analysis

International Nuclear Information System (INIS)

Rybovic, Michala; Halkett, Georgia K.; Banati, Richard B.; Cox, Jennifer

2008-01-01

Background and purpose: Our aim was to explore radiation therapists' views on the level of experience necessary to undertake portal image analysis and clinical decision making. Materials and methods: A questionnaire was developed to determine the availability of portal imaging equipment in Australia and New Zealand. We analysed radiation therapists' responses to a specific question regarding their opinion on the minimum level of experience required for health professionals to analyse portal images. We used grounded theory and a constant comparative method of data analysis to derive the main themes. Results: Forty-six radiation oncology facilities were represented in our survey, with 40 questionnaires being returned (87%). Thirty-seven radiation therapists answered our free-text question. Radiation therapists indicated three main themes which they felt were important in determining the minimum level of experience: 'gaining on-the-job experience', 'receiving training' and 'working as a team'. Conclusions: Radiation therapists indicated that competence in portal image review occurs via various learning mechanisms. Further research is warranted to determine perspectives of other health professionals, such as radiation oncologists, on portal image review becoming part of radiation therapists' extended role. Suitable training programs and steps for implementation should be developed to facilitate this endeavour

Discrete level schemes and their gamma radiation branching ratios (CENPL-DLS). Pt. 1

International Nuclear Information System (INIS)

Su Zongdi; Zhang Limin; Zhou Chunmei; Sun Zhengjun

1994-01-01

The DLS data file, which is a sub-library (version 1) of Chinese Evaluated Nuclear Parameter Library (CENPL), consists of data and information of discrete levels and gamma radiations. The data and information of this data file are translated from the Evaluated Nuclear Structure Data File (ENSDF). The transforming code from ENSDF to DLS was written. In the DLS data file, there are the data on discrete levels with determinate energy and their gamma radiations. At present, this file contains the data of 79456 levels and 100411 gammas for 1908 nuclides

Radiation protection law

International Nuclear Information System (INIS)

Hebert, J.

1981-01-01

This article first reviews the general radiation protection law at international and national level, with particular reference to the recommendations of the International Commission on Radiological Protection (ICRP) which, although not mandatory, are nevertheless taken into consideration by international organisations establishing basic radiation protection standards such as the UN, IAEA, NEA and Euratom, at Community level, and by national legislation. These standards are therefore remarkably harmonized. Radiation protection rule applied in France for the different activities and uses of radioactive substances are then described, and finally, a description is given of the regulations governing artificial radioisotopes and radioactive effluents. (NEA) [fr

Radiation-related operator's dose distribution according to LLD(recording level)

International Nuclear Information System (INIS)

Park, Jae Duck

2008-01-01

Recently, the area of radiation usage is being enlarged by the industry's advancement over the world. And, the usage of radiation generator and radioisotope is increasing every year. So, they are researching actively how to protect operators from the radiation that causes direct or indirect harmfulness to radiation-related operators of the related institutions. Therefore, in case of operator's dose, not only the main dosimeter's correctness but also the reasonal evaluation to the read values becomes the important factor. From this view, LLD's application to the read dose value is being embossed more importantly than any other thing. So, this study tried to find out what change was generated in the personal dose and the group dose when LLD was applied based on the internal real operator's read value, for 3 years, 2005 - 2007, and find out the personal dose change after dividing them into the exposure group and the supervising group based on the common people's personal dose (1 mSv/y)

Radiation exposure rate and liquid level measurement inside a high level liquid waste (HLLW) storage tank

International Nuclear Information System (INIS)

Sur, B.; Yue, S.; Thekkevarriam, A.

2007-01-01

An instrument based on an inexpensive, small silicon diode has been developed and used to measure, for the first time, the gamma radiation exposure rate profile inside a 6.4 mm diameter reentrant thermo-well tube, immersed in the highly radioactive liquid solution in an HLLW storage tank. The measurement agrees with previous calculations of exposure rate, and provides confirmation for safe and effective radiation work plans and material selection for investigations and remediation of the storage tank facility. The measured radiation exposure rate profile is also used to confirm that the position of tank internal structures have not changed because of aging and corrosion, and to obtain, within a few mm, the level of liquid inside the tank. (author)

Prompt radiation activation analysis, (1) Theoretical study

International Nuclear Information System (INIS)

EL Barouni, A. M.; Araddad, S. Y.; Mosbah, D. S.; Elfakhri, S. M.; Rateb, J. M.; Benghzail, M. A.

2004-01-01

The measurement of the prompt γ following neutron capture in the reaction has been extensively developed. In this method the gamma-ray intensity is depended only upon the radiative capture cross-section and not upon the half-life of the product nucleus. The prompt gamma-ray activation analysis method stems from the radiative capture process which results in the decay of the compound nucleus by the emission of characteristic gamma radiation, either as a single photon with kinetic energy equal to the excitation energy less the recoil energy or, more likely, by a cascade of two or more photons with the same energy. The equations and the computer program required to calculate the yield, the intensity and the K χ emission probability per disintegration, are given in this study.(author)

Relationship of in-coming radiation with photosynthetically active, infra-red and net radiations in Brassica species and rocket salad (Eruca sativa)

International Nuclear Information System (INIS)

Nandwal, A.S.; Kuhad, M.S.

1989-01-01

Marked variation was observed among genotypes when the data for in-coming solar radiation were monitored horizontally. The regression equation for in-coming solar radiation versus photosynthetically active radiation and incoming solar radiation versus in-coming infra red radiation indicated linear relationship

Health effects of low-level radiation in shipyard workers. Final report: [Draft

Energy Technology Data Exchange (ETDEWEB)

Matanoski, G.M.

1991-06-01

The Nuclear Shipyard Workers Study (NSWS) was designed to determine whether there is an excess risk of leukemia or other cancers associated with exposure to low levels of gamma radiation. The study compares the mortality experience of shipyard workers who qualified to work in radiation areas to the mortality of similar workers who hold the same types of jobs but who are not authorized to work in radiation areas. The population consists of workers from six government and two private shipyards.

Activities of the Institute of Radiation Protection and Dosimetry on radiation overexposure analysis - results from 1994 to 1997

International Nuclear Information System (INIS)

Silva, Francisco C.A. da; Ramalho, Adriana

1999-01-01

Since 1985 the Institute of Radiation Protection and Dosimetry has operated a service carried out by a multi-disciplinary Group called Radiation Overexposure analysis Group - GADE. It is composed of specialists in radiation protection and dosimetry and has the main objective of taking coordinated actions on radiation overexposure cases. This paper shows mainly the results got from 1984 to 1997 with the methodology used. It was observed that the cases are falling down due to radiation protection activities in the installation. (author)

Linear devices in combined high-level radiation environments

International Nuclear Information System (INIS)

van Vonno, N.W.

1987-01-01

The design of precision analog integrated circuits for use in combined high-level radiation environments has traditionally been on a full-custom basis. The use of semicustom design methods has become prevalent in digital devices, with standard cell libraries and gate arrays readily available from multiple vendors. This paper addresses the application of semicustom design techniques to analog parts. In all cases the emphasis is on bipolar technology, since this provides an optimal combination of precision and radiation hardness. A mixed mode analog/digital (A/D) cell family for implementing semicustom designs is described, together with the fabrication process used. Specific processing and design methods are used to provide circuit hardness against neutron, total gamma dose, and transient gamma environments. Semicustom mixed analog/digital design is seen as an appropriate methodology for implementation of medium-performance mixed mode functions for radiation-hardened applications. This leads to trade-offs in process complexity and performance. Full custom design remains necessary for demanding applications such as high-speed A/D conversion and associated sample/hold functions. An A/D cell family optimized for hardness is described, together with the bipolar process used to implement it

JAIF's teacher support activity on radiation education

International Nuclear Information System (INIS)

Kito, K.; Kudo, K.

2016-01-01

Japan Atomic Industrial Forum (JAIF) has been conducting science teacher support activities on radiation education since 2011, after the Fukushima NPP Accident, in cooperation with member organizations of the Japan Nuclear Human Resource Development Network (JN-HRD Net). (author)

Energy levels and radiative rates for transitions in Ti VI

International Nuclear Information System (INIS)

Aggarwal, K M; Keenan, F P; Msezane, A Z

2013-01-01

We report on calculations of energy levels, radiative rates, oscillator strengths and line strengths for transitions among the lowest 253 levels of the (1s 2 2s 2 2p 6 ) 3s 2 3p 5 , 3s3p 6 , 3s 2 3p 4 3d, 3s3p 5 3d, 3s 2 3p 3 3d 2 , 3s 2 3p 4 4s, 3s 2 3p 4 4p and 3s 2 3p 4 4d configurations of Ti VI. The general-purpose relativistic atomic structure package and flexible atomic code are adopted for the calculations. Radiative rates, oscillator strengths and line strengths are reported for all electric dipole (E1), magnetic dipole (M1), electric quadrupole (E2) and magnetic quadrupole (M2) transitions among the 253 levels, although calculations have been performed for a much larger number of levels. Comparisons are made with existing available results and the accuracy of the data is assessed. Additionally, lifetimes for all 253 levels are listed, although comparisons with other theoretical results are limited to only 88 levels. Our energy levels are estimated to be accurate to better than 1% (within 0.03 Ryd), whereas results for other parameters are probably accurate to better than 20%. A reassessment of the energy level data on the National Institute of Standards and Technology website for Ti VI is suggested. (paper)

Effects of chronic low level radiation in the population residing in the high level natural radiation area in Kerala, India: employing heritable DNA mutation studies.

Science.gov (United States)

Ahmad, Shazia; Koya, P K M; Seshadri, M

2013-03-18

To study the effect of chronic low level radiation, 4040 meiosis were screened at eight microsatellite and five minisatellite (2485 and 1555 meiosis respectively) marker loci in people residing in high and normal level natural radiation areas of Kerala. Variants in the repeat length of allele were considered as mutants. Mutation rates (expressed as the number of mutations observed in the total number of meiosis) were 6.4×10(-3) (16/2485) and 2.6×10(-3) (4/1555) at microsatellite and minisatellite respectively. The germline microsatellite mutation frequency of father was 1.78 times higher at 7.52×10(-3) (8/1064) compared to 4.22×10(-3) (6/1421) of mother (P=0.292, Fisher's Exact two-sided test). The paternal and maternal mutation rates at minisatellite loci were more or less similar at 2.78×10(-3) (2/719) and 2.39×10(-3) (2/836), respectively (P=1.0, Fisher's Exact two-sided test). Higher but statistically non-significant microsatellite mutation frequency was observed in HLNRA compared to NLNRA (7.25×10(-3) vs 3.64×10(-3); P=0.547). The apparent increase in the mutation rate of microsatellite loci with the increase in radiation dose was also not statistically significant. All the four minisatellite mutation observed were from HLNRA (1198 meiosis) and no mutation was observed among 357 meiosis screened from NLNRA families. All the markers used in the present study were in the non-coding region and hence mutations in these regions may not cause adverse health effects, but the study is important in understanding the effect of chronic low level radiation. Copyright © 2012 Elsevier B.V. All rights reserved.

[Effect of Low-Intensity 900 MHz Frequency Electromagnetic Radiation on Rat Brain Enzyme Activities Linked to Energy Metabolism].

Science.gov (United States)

Petrosyan, M S; Nersesova, L S; Gazaryants, M G; Meliksetyan, G O; Malakyan, M G; Bajinyan, S A; Akopian, J I

2015-01-01

The research deals with the effect of low-intensity 900 MHz frequency electromagnetic radiation (EMR), power density 25 μW/cm2, on the following rat brain and blood serum enzyme activities: creatine kinase (CK), playing a central role in the process of storing and distributing the cell energy, as well as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) that play a key role in providing the conjunction of carbohydrate and amino acid metabolism. The comparative analysis of the changes in the enzyme activity studied at different times following the two-hour single, as well as fractional, radiation equivalent of the total time showed that the most radiosensitive enzyme is the brain creatine kinase, which may then be recommended as a marker of the radio frequency radiation impact. According to the analysis of the changing dynamics of the CK, ALT and AST activity level, with time these changes acquire the adaptive character and are directed to compensate the damaged cell energy metabolism.

Photosynthetically-active radiation: sky radiance distributions under clear and overcast conditions

International Nuclear Information System (INIS)

Grant, R.H.; Heisler, G.M.; Gao, W.

1996-01-01

The photosynthetically active radiation (PAR), defined as the wavelength band of 0.400 μm to 0.700 μm, represents most of the visible solar radiation. Although the proportion of global irradiance that originates from diffuse sky radiation is higher for PAR than for all solar shortwave radiation, it is often assumed that the PAR diffuse sky radiation is distributed identically to that of all shortwave solar radiation. This assumption has not been tested. PAR sky radiance measurements were made in a rural area over a wide range of solar zenith angles. The distribution of PAR sky radiance was modeled using physically-based, non-linear equations.For clear skies, the normalized sky radiance distribution (N) was best modeled using the scattering angle (ψ) and the zenith position in the sky (Θ) as N (Θ, ψ) = 0.0361 [6.3 + (1 + cos 2 Θ / (1 - cos ψ)] [1-e -0.31 sec ( Θ]. The angle Ψ is defined by cos ψ = cos Θ cos Θ * + sin Θ sin Θ * cos Φ, where solar zenith angle is Θ* and the difference in azimuth between the sun and the position in the sky is Φ. Modeling of the overcast sky depended on the visibility of the solar disk. The translucent middle/high cloud overcast conditions (cloud base greater than 300 m above ground level) were best modeled as: N(Θ∗, ψ) = 0.149 + 0.084Θ∗ + 1.305e −2.5ψ while the translucent low cloud overcast conditions (cloud base less than 300 m above ground level) were best modeled as: N(Θ∗, ψ) = 0.080 + 0.058Θ∗ + 0.652e −2.1ψ . The obscured overcast sky condition (solar disk obscured) was best modeled as: N(Θ) = 0.441 [1 + 4.6cos Θ] /[1 + 4.6]. The unit of N for all equations is π Sr −1 , so that integration of each function over the sky hemisphere yields 1.0.These equations can be applied directly to the sky diffuse irradiance on the horizontal, I diff , to provide radiance distributions for the sky. Estimates of actual sky radiance distribution can be estimated from N a (Θ, ψ) = I diff N(Θ, �

A guide to radiation and radioactivity levels near high energy particle accelerators

International Nuclear Information System (INIS)

Sullivan, A.H.

1992-01-01

An estimate of likely radiation and radioactivity levels is needed at the design stage of an accelerator for deciding the radiation safety features to be incorporated in the infrastructure of the machine and for predicting where radiation damage possibilities will have to be taken into account. Both these aspects can have a significant influence on the machine layout and cost. Failure to make a reasonable assessment at the right time may have far reaching consequences for future costs. The purpose of this guide is to bring together basic data and methods that have been found useful in assessing radiation situations around accelerators and to provide a practical means of arriving at the radiation and induced radioactivity levels that could occur under a wide variety of circumstances. An attempt is made to present the information in a direct and unambiguous way with sufficient confidence that the necessity for large safety factors is avoided. In many cases assumptions and simplifications have been made and reliance placed on extrapolating from experimental data into regions where the basic physics is too complicated to make meaningful absolute calculations. Wherever possible such extrapolations have been tied to real or otherwise acceptable data originating from independent sources. (Author)

Investigation of environmental natural penetrating radiation level in Beijing

International Nuclear Information System (INIS)

Wu Zengxin; Zhang Wenying; Zheng Rukuan; Wei Shujun; Ding Huiqiu

1992-01-01

The authors report the methods and results of investigation of environmental natural penetrating radiation level in Beijing. There were 83 measurement points selected, which were located at the vertexes of 1 x 1 km square meshes and uniformly distributed over the urban district. 173 net grid measuring points selected with grid spacing of 10 x 10 km and uniformly distributed over the suburban district. Another 131 more densely distributed points were added over some special areas. The results show that: (1) The point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate over field is 56.2, 56.4 and 50.1 nGy · h -1 respectively. The γ radiation dose rate is higher in west and north area than in southeast area. (2) The point-weighted average value of natural γ radiation dose rate over roads was 49.3 nGy · h -1 . (3) The point weighted and population-weighted average value of natural γ radiation dose inside buildings was 83.5 and 77.1 nGy · h -1 respectively. (4) The weighted average of air absorbed dose rate from the ionizing components of cosmic rays (except for neutron) over point number and population was respectively 29.0 and 27.5 nGy · h -1 indoors, and 32.3 and 30.8 nGy · h -1 outdoors. (5) The point and population-weighted means of natural penetrating radiation dose rate (the contribution from neutron is not included) are 112.8 and 104.5 nGy · h -1 indoors, respectively; 88.7 and 81.3 nGy · h -1 outdoors, respectively. (6) The annual effective dose equivalent per capital people natural γ radiation, cosmic ray and natural penetrating radiation was 0.43, 0.25 and 0.68 mSv respectively, and the annual collective effective dose equivalent was 4.0, 2.3 and 6.3 x 10 3 man · Sv, respectively

Radiation induced deep level defects in bipolar junction transistors under various bias conditions

International Nuclear Information System (INIS)

Liu, Chaoming; Yang, Jianqun; Li, Xingji; Ma, Guoliang; Xiao, Liyi; Bollmann, Joachim

2015-01-01

Bipolar junction transistor (BJT) is sensitive to ionization and displacement radiation effects in space. In this paper, 35 MeV Si ions were used as irradiation source to research the radiation damage on NPN and PNP bipolar transistors. The changing of electrical parameters of transistors was in situ measured with increasing irradiation fluence of 35 MeV Si ions. Using deep level transient spectroscopy (DLTS), defects in the bipolar junction transistors under various bias conditions are measured after irradiation. Based on the in situ electrical measurement and DLTS spectra, it is clearly that the bias conditions can affect the concentration of deep level defects, and the radiation damage induced by heavy ions.

Sequential activation of proteases in radiation induced apoptosis

International Nuclear Information System (INIS)

Watters, D.; Waterhouse, N.

1997-01-01

Full text: Significant advances have been made in recent years in unraveling the molecular mechanisms of apoptosis particularly in relation to Fas- and TNF-mediated cell death, however there are considerable gaps in our knowledge of the processes involved in apoptosis induced by ionizing radiation. We have used the degradation of specific proteolytic targets in a pair of isogenic Burkitt's Iymphoma cells lines (BL30A, sensitive and BL30K resistant) to study the sequence of events in the execution of radiation-induced apoptosis. Fodrin can be cleaved to fragments of 150 kDa and 120 kDa. In the case of Fas-mediated apoptosis both cleavages are inhibited by the caspase inhibitor zVAD-fmk at 10 μM, a concentration which inhibits all the hallmarks of apoptosis. However in radiation-induced apoptosis, inhibition of the clevage of fodrin to the 150 kDa fragment requires 100 μM zVAD-fink while apoptosis itself is inhibited at 10 μM. This suggests that different enzymes are responsible for the generation of the 150 kDa fragment in the two models of apoptosis. Fodrin has been reported to be cleaved by μ-calpain to a 150 kDa fragment however, the involvement of μ-calpain in apoptosis has not yet been established. In murine fodrin there is a caspase cleavage site within 1 kDa of the calpain cleavage site. In vitro studies using purified enzymes showed that only caspase-3 and μ-calpain could cleave fodrin in untreated cell extracts to the same sized fragments as seen during apoptosis in vivo. We provide evidence for the early activation of μ-calpain after ionizing radiation in the sensitive BL30A cell line, and show that the time course of μ-calpain activation parallels that of the appearance of the 150 kDa fragment. Caspase-3 is activated much later and is likely to be responsible for the generation of the 120 kDa fragment. μ-Calpain was not activated in the resistant cell line. Based on these results we propose a model for the proteolytic cascade in radiation

Radiation levels in samples of dicalcium phosphate (DCP) and bovine and poultry rations by gamma-ray spectrometry

Energy Technology Data Exchange (ETDEWEB)

Luz Filho, Isaias Venancio da; Scheibel, Viviane; Appoloni, Carlos Roberto, E-mail: isaiasfilhojr@yahoo.com.b [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Fisica

2009-07-01

The objective of the present work is to determine the radiation levels found in bovine rations and in the dicalcium phosphate (DCP) feed supplement. Knowledge of the radiation levels in samples of rations and DCP for cattle is important, because they are directly and indirectly-part of the human diet. In order to obtain this data, gamma-ray spectrometry technique was used, employing a HPGe detector of 66% of relative efficiency, with an energy resolution of 2.03 KeV for the {sup 60}Co 1332.46 KeV line. The radioactive activity of the radionuclides {sup 40}K, {sup 137}Cs, {sup 238}U, {sup 232}Th and its respective decay series was measured. The accommodation recipient of the samples was a Marinelli beaker of 1 L. The {sup 238}U series activities were calculated through {sup 214}Pb and {sup 214}Bi activities, and the {sup 232}Th series' activity was calculated through the {sup 228}Ac, {sup 212}Pb, {sup 212}Bi and {sup 208}Tl values. The DCP samples and the rations measured in this work were produced in Londrina city, Brazil, in the second semester of 2007. Among the rations, the largest {sup 40}K and {sup 228}Ra activities were found in the ration sample for milk cattle, 402 +- 14 and 1.71 +- 0.10 Bq/kg, respectively. The ration for beef cattle yielded the largest activity for {sup 226}Ra, 1.51 + 0.93 Bq/kg. In the DCP sample, the activities for the {sup 238}U, {sup 40}K and {sup 232}Th were respectively 83 +- 26; 46.6 +- 2.8 and 7.79 +- 0.70 Bq/kg. The MDA values for {sup 137}Cs varied from 0.037 to 0.29 Bq/kg. (author)

Activated barrier crossing dynamics in the non-radiative decay of NADH and NADPH

Energy Technology Data Exchange (ETDEWEB)

Blacker, Thomas S., E-mail: t.blacker@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Marsh, Richard J., E-mail: richard.marsh@ucl.ac.uk [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Duchen, Michael R., E-mail: m.duchen@ucl.ac.uk [Research Department of Cell and Developmental Biology, University College London, London WC1E 6BT (United Kingdom); Bain, Angus J., E-mail: a.bain@ucl.ac.uk [Centre for Mathematics and Physics in the Life Sciences and Experimental Biology (CoMPLEX), University College London, London WC1E 6BT (United Kingdom); Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

2013-08-30

Highlights: ► NADH and NADPH have a high rate of non-radiative excited state decay. ► Conformational relaxation is shown to be a significant non-radiative pathway. ► The Kramers equation describes the barrier crossing dynamics of the relaxation. ► Conformational restriction upon enzyme binding will alter NAD(P)H lifetimes. - Abstract: In live tissue, alterations in metabolism induce changes in the fluorescence decay of the biological coenzyme NAD(P)H, the mechanism of which is not well understood. In this work, the fluorescence and anisotropy decay dynamics of NADH and NADPH were investigated as a function of viscosity in a range of water–glycerol solutions. The viscosity dependence of the non-radiative decay is well described by Kramers and Kramers–Hubbard models of activated barrier crossing over a wide viscosity range. Our combined lifetime and anisotropy analysis indicates common mechanisms of non-radiative relaxation in the two emitting states (conformations) of both molecules. The low frequencies associated with barrier crossing suggest that non-radiative decay is mediated by small scale motion (e.g. puckering) of the nicotinamide ring. Variations in the fluorescence lifetimes of NADH and NADPH when bound to different enzymes may therefore be attributed to differing levels of conformational restriction upon binding.

Conversion Efficiency of Photosynthetically Active Radiation Into Acacia mearnsii Biomass

Directory of Open Access Journals (Sweden)

Elder Eloy

2018-02-01

Full Text Available ABSTRACT The objective of this experiment was to determine the conversion efficiency of intercepted photosynthetically active radiation into biomass of Acacia mearnsii De Wild. seedlings. A forest species, plastic tubes (90 cm3, and 11 evaluation periods (up to 180 days after emergence were used in this study. The leaf area index (LAI, total dry biomass (BIO, global solar radiation (GSR, cumulative intercepted photosynthetically active radiation (PARic, and conversion efficiency of radiation (εb were determined using a pyranometer (LI200X, LICOR. The value of εb in BIO seedlings of Acacia mearnsii was 7.76 g MJ-1. LAI was directly related to the efficiency of PARic, and this influenced the development, production potential and accumulation of BIO. The value of GSR flow was 11.81 MJ m-2 day-1, while the value inside the greenhouse was 6.26 MJ m-2 day-1.

13th AINSE radiation biology conference: conference handbook

International Nuclear Information System (INIS)

1991-01-01

The forty one papers presented at this conference covered the areas of radiation induced lesions, apoptosis, genetics and radiobiological consequences of low level radiation exposure, clinical applications of radiation, mammalian cells radiosensitivity and radiation-activated proteins

Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

Energy Technology Data Exchange (ETDEWEB)

Fabrikant, J.I.

1982-04-01

Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation. (ERB)

Carcinogenesis and low-level ionizing radiation with special reference to lung cancer and exposure to radon daughters

International Nuclear Information System (INIS)

Fabrikant, J.I.

1982-04-01

Of the important health effects of ionizing radiation, three important late effects - carcinogenesis, teratogenesis and mutagenesis are of greatest concern. This is because any exposure, even at low levels, carries some risk of such deleterious effects. As the dose of radiation increases above very low levels, the risk of health effects increases. Cancer-induction is the most important late somatic effect of low-dose ionizing radiation. Solid cancers, rather than leukemia, are principal late effects in exposed individuals. Tissues vary greatly in their susceptibility to radiation carcinogenesis. The most frequently occurring radiation-induced cancers in man include, in decreasing order of susceptibility: the female breast, the thyroid gland, the blood-forming tissues, the lung, certain organs of the gastrointestinal tract, and the bones. A number of biological and physical factors affect the cancer risk, such as age, sex, life-style, LET, and RBE. Despite uncertainty about low-level radiation risks, regulatory and advisory bodies must set standards for exposure, and individuals need information to be able to make informed judgments for themselves. From the point of view of the policy maker, the overriding concern is the fact that small doses of radiation can cause people to have more cancers than would otherwise be expected. While concern for all radiation effects exists, our human experience is limited to cancer-induction in exposed populations. This discussion is limited to cancer risk estimation and decision-making in relation to the health effects on populations of exposure to low levels of ionizing radiation. Here, low-level radiation will refer to yearly whole-body doses up to 5 rems or 0.05 Sv, or to cumulative doses up to 50 rems or 0.5 Sv from low-LET radiation and from high-LET radiation

Serum pepsin levels Hiroshima adult health study. Relation to radiation, ABO blood groups, and gastrointestinal diseases

Energy Technology Data Exchange (ETDEWEB)

Knittle, J L

1961-07-12

At the ABCC clinic in Hiroshima 1330 subjects were investigated as to serum pepsin levels over a four month period. The normal mean values compared well with those reported for a United States population using a similar technique. There appeared to be no significant change in serum pepsin level with age, and no difference could be detected among individuals of the ABO blood groups. No relationship was found between serum pepsin level and exposure to ionizing radiation. Patients with gastric and duodenal ulcers had mean levels which were higher than normal mean values, while patients with leukemia had lower than normal mean levels. Patients with gastric polyps and gastric cancer had normal mean values. It is believed that the relation of serum pepsin activity to cancer of the stomach is not settled and deserves further investigation. 23 references, 2 figures, 4 tables.

Current radiation protection activities of the International Atomic Energy Agency

International Nuclear Information System (INIS)

Webb, G.A.M.

1996-01-01

The International Atomic Energy Agency (IAEA) program of the Radiation Safety Section is described in this paper. The Section has two main components: (1) the development of consensus safety documentation and (2) the use of that documentation as the basis for assisting countries to deal safely with their applications of radiation and radioactivity. Main activities of the section are listed for each of these components. Activities include documentation, coordinated research programs, and assistance to developing countries. 14 tabs

Radiation safety handbook for ionizing and nonionizing radiation

International Nuclear Information System (INIS)

Kincaid, C.B.

1976-10-01

The Handbook is directed primarily to users of radiation sources throughout the Food and Drug Administration. Specific precautions regarding the possession and use of radiation sources in meeting the Agency's objectives are an inherent responsibility of all employees. In addition, the increased emphasis on occupational safety and health and the responsibilities placed on the Department by Public Law and Executive Order make it mandatory that all organizational levels and activities conform to the intent of this Handbook. The policies and procedures described in this document apply to all Agency operators and activities and are intended to protect employees and the general public

Activities of Institute of Radiation Protection and Dosimety/Brazil as Technical and Scientific Support Organization on Occupational Radiation Protection

International Nuclear Information System (INIS)

Da Silva, F.C.A.; Ferreira, P.R.; Matta, L.E.C.; Peres, M.A.L.; Godoy, J.M.; Alencar, M.A.V.; Carlos, M.T.; Souza-Santos, D.; Leocadio, J.C.; Oliveira, M.S.

2010-01-01

There are, in Brazil, about 126,000 workers registered on National Dose Registry System (SRD/IRD) as occupationally exposed. They work on 4,000 radioactive installations, 20 nuclear fuel cycle installations and with 90,000 x-ray diagnostic devices. There are two main Regulatory Authorities to license and control these installations on nuclear and radioactive areas, and another Regulatory Authority that is responsible for safety and health protection of workers on their labour activities. Belonging to structure of the National Commission of Nuclear Energy (CNEN-Brazil) there is an Institute dedicated to radiation protection, dosimetry and metrology of ionizing radiation, that is the Institute of Radiation Protection and Dosimetry (IRD). This paper presents two main IRD activities related to occupational radiation protection that can be seen as example of technical and scientific support to Regulatory Authorities: the Radiation Overexposure Analysis that is performed by the Radiation Overexposure Analysis Group (GADE) and the Approval of Individual Monitoring Services and Calibration Laboratory of Equipment used in Radiation Protection that is performed by the Committee for the Evaluation of Essay and Calibration Services (CASEC). (author)

Investigation of the electromagnetic radiation field level in the vicinity of Damascus international airport

International Nuclear Information System (INIS)

Abukassem, I.

2011-07-01

The aim of this work is to estimate the electromagnetic radiation exposure of Damascus international airport workers.Different kinds of electromagnetic wave sources exist in the vicinity of the airport, for example, mobile phone base stations. It was found that the exposure level in all studied points (offices, halls, traffic control tour, etc) is lower than the international restriction levels. Few recommendations were given for some work situation or places where the measured electromagnetic radiation levels were relatively high.(author)

Radio frequency radiation effects on protein kinase C activity in rats' brain

International Nuclear Information System (INIS)

Paulraj, R.; Behari, J.

2004-01-01

The present work describes the effect of amplitude modulated radio frequency (rf) radiation (112 MHz amplitude-modulated at 16 Hz) on calcium-dependent protein kinase C (PKC) activity on developing rat brain. Thirty-five days old Wistar rats were used for this study. The rats were exposed 2 h per day for 35 days at a power density of 1.0 mW/cm 2 (SAR=1.48 W/kg). After exposure, rats were sacrificed and PKC was determined in whole brain, hippocampus and whole brain minus hippocampus separately. A significant decrease in the enzyme level was observed in the exposed group as compared to the sham exposed group. These results indicate that this type of radiation could affect membrane bound enzymes associated with cell signaling, proliferation and differentiation. This may also suggest an affect on the behavior of chronically exposed rats

A possible methodological approach to setting up control level of radiation factors

International Nuclear Information System (INIS)

Devyatajkin, E.V.; Abramov, Yu.V.

1986-01-01

The mathematical formalization of the concept of control levels (CL) which enables one to obtain CL numerical values of controllable parameters required for rapid control purposes is described. The initial data for the assessment of environmental radioactivity are the controllable parameter values that is practical characteristic of controllable radiation factor showing technically measurable or calculation value. The controllable parameters can be divided into two classes depending on the degree of radiation effect on a man: possessing additivity properties (dosimetric class) and non-possessing (radiation class, which comprises the results of control of medium alteration dynamics, equipment operation safety, completeness of protection measures performance). The CL calculation formulas with account for requirements of radiation safety standards (RSS-76) are presented

Critical review of the Hanford worker studies: cancer risk and low-level radiation

International Nuclear Information System (INIS)

Savitz, D.A.

1983-01-01

Current estimates of cancer risks attributable to low-level radiation exposure are extrapolated from effects observed at higher doses. The inherent uncertainties in this approach make direct study of low-dose effects in human populations of great significance. Employees of the Hanford works in Richland, Washington constitute a large group of workers exposed to low-level radiation. The cancer mortality patterns in relation to radiation dose have been discussed by numerous investigators beginning with Mancuso, Stewart, and Kneale in 1977 and continuing to the present. These studies and their published critiques are summarized, with an effort to account for discrepant results by careful review of the analytic methods. Detailed consideration is given to exposure definition, classification of health outcomes, latency, the statistical methods employed, and selection biases. From this, it is concluded that (a) total cancers are unrelated to radiation exposure among these workers; (b) multiple myeloma and pancreatic cancer show a positive association with radiation dose based upon a few highly exposed cases; and (c) the relationship of radiosensitive cancers in the aggregate to radiation exposure is unresolved. Further study of the temporal course of exposure and latency in a classical cohort analysis of radiosensitive cancers might be informative, with special attention to the possibility of selection for jobs within the cohort

A method of alpha-radiating nuclide activity measuring in aerosol filters

International Nuclear Information System (INIS)

Ignatov, V.P.; Galkina, V.N.

1992-01-01

Scintillation method of determination of alpha-radiating nuclide activity in aerosol filters was suggested. The method involves dissolution of the filter in organic solvent, introduction of luminophore into solution prepared, drying of the preparation and measurement of radionuclide activity. Dependences of alpha-radiation detection efficiency on the content of luminophore, filter material, colourless and coloured substances in preparations analyzed were considered

Measurement of radiation levels in soil samples by γ-ray spectrometry

International Nuclear Information System (INIS)

Sontakke, C.V.; Thamke, A.N.; Devika, K.; Srikanth, S.; Jayachandran, N.; Chander, Harish

2016-01-01

The natural terrestrial gamma radiation dose rate is an important contribution to the average dose rate received by the world's population. Estimation of the radiation dose distribution is important in assessing the health risk to a population and serve as the reference in documenting changes to environmental radioactivity in soil due to anthropogenic activities. Human beings are exposed outdoors to the natural terrestrial radiation that originates predominantly from the upper 30 cm of the soil. Only radionuclides with half-lives comparable with the age of the earth or their corresponding decay products existing in terrestrial material such as 238 U, 232 Th and 40 K are of great interest. Since these radionuclides are not uniformly distributed, the knowledge of their distribution in soil and rock play an important role in radiation protection and measurement. Gamma radiation from these represents the main external source of irradiation to the human body and the concentrations of these radionuclides in soil are determined by the radioactivity of the rock and also nature of the process of the formation of the soils. Therefore, radionuclides in soil generate a significant component of the background radiation exposure to the population

Asymmetric active nano-particles for directive near-field radiation

DEFF Research Database (Denmark)

Arslanagic, Samel; Thorsen, Rasmus O.

2016-01-01

In this work, we demonstrate the potential of cylindrical active coated nano-particles with certain geometrical asymmetries for the creation of directive near-field radiation. The particles are excited by a near-by magnetic line source, and their performance characteristics are reported in terms...... of radiated power, near-field and power flow distributions as well as the far-field directivity....

Approaches to assign security levels for radioactive substances and radiation sources

International Nuclear Information System (INIS)

Ivanov, M.V.; Petrovskij, N.P.; Pinchuk, G.N.; Telkov, S.N.; Kuzin, V.V.

2011-01-01

The article contains analyzed provisions on categorization of radioactive substances and radiation sources according to the extent of their potential danger. Above provisions are used in the IAEA documents and in Russian regulatory documents for differentiation of regulatory requirements to physical security. It is demonstrated that with the account of possible threats of violators, rules of physical protection of radiation sources and radioactive substances should be amended as regards the approaches to assign their categories and security levels [ru

Effects of low-level radiation on biologic systems: a literature review

International Nuclear Information System (INIS)

Best, T.L.; Hoditschek, B.

1980-12-01

This review presents an organized survey of scientific literature dealing with the biologic effects of low-level radiation. It includes brief discussions of topics of particular interest, a listing of useful review articles, an extensive bibliography, and listings of sources that can be used to update this document in the future. The topics discussed include experimental studies, the linear hypothesis, medical effects, occupational effects, effects of exposure to naturally occurring radiation, consumer products, and laws and regulations

Investigation of environmental natural penetrating radiation level in Anhui province

International Nuclear Information System (INIS)

Zhu Jingqiu; Chen Shuping; Jiang Shan; Zhu Xingsheng; Huang Jiangbin; Wu Chuanyong; Wang Weining

1992-01-01

The methods and results of the investigation on natural penetrating radiation level in Anhui Province in 1987 are presented. The results show that: (1) The point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate for field is 5.67, 5.62 and 5.55 x 10 -8 Gy· -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 5.38 x 10 -8 Gy·h -1 ; (3) The point-weighted and population-weighted average value of natural γ radiation dose rate inside buildings is 9.59 and 9.36 x 10 -8 Gy·h -1 , respectively; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 2.64 and 2.62 x 10 -8 ·h -1 , and outside buildings is 2.95 and 2.94 x 10 -8 ·h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 12.23 and 11.99 x 10 -8 Gy·h -1 , outside buildings is 8.62 and 8.49 x 10 -8 ·h -1 , respectively; (6) The annual effective dose equivalent from natural γ radiation, cosmic ray and natural penetrating radiation is 0.51, 0.24, and 0.75 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 2.5, 1.2 and 3.7 x 10 4 man·Sv, respectively

Techniques for detecting and determining risks from low-level radiation

International Nuclear Information System (INIS)

Boice, J.D.

1980-01-01

Epidemiology is the study of disease in man. In evaluating radiation hazards, analytic studies have utilized the cohort type of investigation (where persons exposed and not exposed to radiation are followed forward in time for determination of disease experience) or case-control approaches (where persons with and without a specific disease are evaluated for previous exposure to radiation). Most radiation studies have evaluated cohorts (e.g., radiologists), although important case-control studies have been conducted (e.g., childhood leukemia as related to prenatal x ray). At its best, epidemiology is capable fo evaluating relative risks (RR) on the order of 1.4 (i.e., a 40% relative excess). However, the RRs of interest following low doses of radiation (1 rad) are on the order of 1.02-1.002. Thus, not much should be anticipated from direct observations at 1 rad, and indirect approaches must be taken to estimate low-dose effects. Such indirect approaches include evaluating 1) populations exposed to a range of doses, both low and high, where interpolation models can be reasonably applied to estimate low-dose effects; and 2) populations exposed to fractionated doses over a long period of time where the resulting dose-effect relationship theoretically should be linear and the estimation of low-level health effects facilitated

The correlation between osteopontin level and radiation response of malignant gliomas at Cipto Mangunkusumo Hospital

Directory of Open Access Journals (Sweden)

Isnaniah Hasan

2016-12-01

Full Text Available Osteopontin is an endogenous molecular marker for tumor hypoxia, and hypoxia is one of the factors that determine the aggressiveness of the disease. The purpose of this study is to determine the correlation between osteopontin levels and radiation response in malignant glioma. A retrospective cohort study was conducted on 15 malignant glioma patients who underwent radiation therapy from July 2004 to May 2015 at the RSUPN Dr. Cipto Mangunkusumo Hospital. Osteopontin levels were measured from paraffin-embedded tissue using a commercial ELISA kit. Tumor volume was calculated using computed tomography (CT scan and magnetic resonance imaging (MRI images, based on three-dimensional volume measurements. Tumor response was evaluated by comparing pre- and post-radiation tumor volumes using CT scan and MRI images. The mean osteopontin level was 0.49 ± 0.45 ng/mL and the mean percentage change in tumor volume was 8.59 ± 54.22%, with a 60% enlargement in tumor volume. A progressive disease was found in 26.7% of patients. There was a weak but insignificant negative correlation (r = -0.39, p = 0.146 between the level of osteopontin and radiation response. In contrast, there was a strong but insignificant positive correlation (r = +0.68, p = 0.219 between the level of osteopontin and radiation response in the patient group that used the chemosensitizer temozolamide.

Preliminary radiation-oxidizing treatment influence on radiation-catalytic activity of zirconium during water decomposition process

International Nuclear Information System (INIS)

Garibov, A.A.; Aliyev, A.G.; Agayev, T.N.; Aliyev, S.M.; Velibekova, G.Z.

2004-01-01

The study of physical-chemical processes proceeding in contact of metal constructional materials nuclear reactors with water at simultaneous influence of temperature and radiation represents the large interest at the decision of problems material authority and safety of work of nuclear -power installations [1-2]. One of the widely widespread materials of active zone nuclear reactors is metal zirconium and its alloys. The influence of preliminary radiation processing on radiation, radiation -thermal and thermal processes of accumulation of molecular hydrogen and oxidation zirconium in contact with water is investigated at T=673 K and ρ=5mg/sm 3 [3-4]. Initial samples zirconium previously has been exposed by an irradiation in medium H 2 O 2 at D=20-410 kGy. The contribution of radiation processes in these contacts in process thermo-radiation decomposition of water and oxidation of materials of zirconium is revealed. It is established that the interaction of Zr metal, preliminary treated by radiation, with water at radiation -heterogeneous processes leads to passivity of a surface. The rate meanings of thermal, radiation -thermal processes and radiation-chemical yields of hydrogen are determined. It is revealed, that at radiation-heterogeneous processes in system Zr +H 2 O (ρ =5mg/sm 3 T=673 K) the increase of the absorbed doze up to 123 kGy results to reduction of a radiation -chemical yield of molecular hydrogen. The further increase of the absorbed doze results to increase of a radiation -chemical yield of hydrogen. The observable effect at the preliminary radiation of zirconium is connected to formation of oxide phase on a surface. The mechanism of radiation -heterogeneous processes proceeding in system Zr+H 2 O is suggested. (author)

Activation and radiation damage in the environment of hadron accelerators

CERN Document Server

Kiselev, Daniela

2013-01-01

A component which suffers radiation damage usually also becomes radioactive, since the source of activation and radiation damage is the interaction of the material with particles from an accelerator or with reaction products. However, the underlying mechanisms of the two phenomena are different. These mechanisms are described here. Activation and radiation damage can have far-reaching consequences. Components such as targets, collimators, and beam dumps are the first candidates for failure as a result of radiation damage. This means that they have to be replaced or repaired. This takes time, during which personnel accumulate dose. If the dose to personnel at work would exceed permitted limits, remote handling becomes necessary. The remaining material has to be disposed of as radioactive waste, for which an elaborate procedure acceptable to the authorities is required. One of the requirements of the authorities is a complete nuclide inventory. The methods used for calculation of such inventories are presented,...

Contributions of the Higher Vibrational Levels of Nitric Oxide to the Radiative Cooling of the Thermosphere

Science.gov (United States)

Venkataramani, K.; Yonker, J. D.; Bailey, S. M.

2014-12-01

The 5.3μm emission from the vibrational levels of nitric oxide (NO) and the 15μm emission from CO2 are known to be the dominant sources of cooling in the thermosphere above 100 km. The 5.3μm emission is primarily produced by the radiative de-excitation of NO from its first vibrational level, which in turn is mainly populated by the collisions of NO with atomic oxygen. However, the reaction of atomic nitrogen (N(4S) and N(2D)) with O2 yields vibrationally excited NO with v>1, resulting in a radiative cascade which produces more than one 5.3μm photon per vibrationally excited NO molecule. This chemiluminescence is approximately 20% in magnitude of the emission produced by thermal collisions. These additional sources of the 5.3μm emission are introduced into a one dimensional photochemical model and the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) to assess their variability with latitude and solar activity, and to also understand their effect on the thermospheric energy budget. The results from the models are compared with data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment on-board the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite, which has been making measurements of the infrared radiative response of the mesosphere and thermosphere to solar inputs since 2002.

Radiation-induced taste aversion: effects of radiation exposure level and the exposure-taste interval

International Nuclear Information System (INIS)

Spector, A.C.; Smith, J.C.; Hollander, G.R.

1986-01-01

Radiation-induced taste aversion has been suggested to possibly play a role in the dietary difficulties observed in some radiotherapy patients. In rats, these aversions can still be formed even when the radiation exposure precedes the taste experience by several hours. This study was conducted to examine whether increasing the radiation exposure level could extend the range of the exposure-taste interval that would still support the formation of a taste aversion. Separate groups of rats received either a 100 or 300 R gamma-ray exposure followed 1, 3, 6, or 24 h later by a 10-min saccharin (0.1% w/v) presentation. A control group received a sham exposure followed 1 h later by a 10-min saccharin presentation. Twenty-four hours following the saccharin presentation all rats received a series of twelve 23-h two-bottle preference tests between saccharin and water. The results indicated that the duration of the exposure-taste interval plays an increasingly more important role in determining the initial extent of the aversion as the dose decreases. The course of recovery from taste aversion seems more affected by dose than by the temporal parameters of the conditioning trial

Dose evaluation and establishment of reference levels in activity for nuclear medicine

International Nuclear Information System (INIS)

Ribeiro, Julio Cesar de Souza

2017-01-01

The International Commission on Radiation Protection (ICRP) has emphasized the importance of accurately determining the mean dose levels, or administered activity, received by the patients for each medical procedure that uses ionizing radiation. However, the number of bibliographic references addressing the need to know and optimize these levels is insufficient, or rather limited, which may lead to non-standardizes techniques, a lack of exposures control, and also the increase of associated radiological risks of these procedures. In this context, a software in Visual Basic® of Microsoft© language was developed whose function is to elaborate a method of obtaining the Reference Levels in Activity (RLA) for nuclear medicine patients by determining the third quartile of the examinations carried out. The program also allows obtaining absorbed dose values in critical organs based on patient specificities as age, sex and Body Mass Index (BMI) in order to evaluate the risk involved in each procedure. The main nuclear medicine diagnostic procedures were evaluated through the database of two public hospitals and a private clinic, obtaining the NRAs of each facility, where the software was validated by comparison with the traditionally accepted calculation methods. Due to the results obtained in each installation, in addition to NRA determination, gaps in treatment capacities and unjustified dose variations for the same procedure were identified, indicating the need for optimization. Thus, the developed program is able to provide the estimated values of effective and absorbed doses involved in each procedure, for each patient, providing reference values for nuclear medicine field, not available in the national scenario so far. (author)

Risk evaluation - conventional and low level effects of radiation

International Nuclear Information System (INIS)

Bond, V.P.; Varma, M.N.

1984-04-01

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

More on direct estimates of low-level radiation risks

International Nuclear Information System (INIS)

Rinsky, R.

1982-01-01

In an epidemiologic study of mortality at the Portsmouth Naval Shipyard (PNS), the National Institute for Occupational Safety and Health (NIOSH) found no evidence of excess deaths due to leukemia or other cancers among workers exposed to low levels of ionizing radiation. In a subsequent analysis, Bross and Driscoll identified excess lung cancer mortality in PNS workers with lifetime radiation dose of 1 rem or greater and with more than 15 years' latency since first radiation exposure. Although that observation may be important and is currently being examined through case-control analyses, it must be recognized that Bross and Driscoll extracted their observation from matrices of over 4,000 data cells apparently by recombination of innumerable possible permutations of dosage and latency intervals. For that reason, their finding can be regarded as no more than a suggestion for further study. It certainly does not represent a proper scientific conclusion. Bross and Driscoll's analysis illustrates the hazard of performing multiple statistical comparisons on complex data sets in the absence of a priori hypotheses

Radiation therapists' perceptions of the minimum level of experience required to perform portal image analysis

Energy Technology Data Exchange (ETDEWEB)

Rybovic, Michala [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825 (Australia)], E-mail: mryb6983@mail.usyd.edu.au; Halkett, Georgia K. [Western Australia Centre for Cancer and Palliative Care, Curtin University of Technology, Health Research Campus, GPO Box U1987, Perth, WA 6845 (Australia)], E-mail: g.halkett@curtin.edu.au; Banati, Richard B. [Faculty of Health Sciences, Brain and Mind Research Institute - Ramaciotti Centre for Brain Imaging, University of Sydney, PO Box 170, Lidcombe, NSW 1825 (Australia)], E-mail: r.banati@usyd.edu.au; Cox, Jennifer [Discipline of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe, NSW 1825 (Australia)], E-mail: jenny.cox@usyd.edu.au

2008-11-15

Background and purpose: Our aim was to explore radiation therapists' views on the level of experience necessary to undertake portal image analysis and clinical decision making. Materials and methods: A questionnaire was developed to determine the availability of portal imaging equipment in Australia and New Zealand. We analysed radiation therapists' responses to a specific question regarding their opinion on the minimum level of experience required for health professionals to analyse portal images. We used grounded theory and a constant comparative method of data analysis to derive the main themes. Results: Forty-six radiation oncology facilities were represented in our survey, with 40 questionnaires being returned (87%). Thirty-seven radiation therapists answered our free-text question. Radiation therapists indicated three main themes which they felt were important in determining the minimum level of experience: 'gaining on-the-job experience', 'receiving training' and 'working as a team'. Conclusions: Radiation therapists indicated that competence in portal image review occurs via various learning mechanisms. Further research is warranted to determine perspectives of other health professionals, such as radiation oncologists, on portal image review becoming part of radiation therapists' extended role. Suitable training programs and steps for implementation should be developed to facilitate this endeavour.

Trade Study of System Level Ranked Radiation Protection Concepts for Deep Space Exploration

Science.gov (United States)

Cerro, Jeffrey A

2013-01-01

A strategic focus area for NASA is to pursue the development of technologies which support exploration in space beyond the current inhabited region of low earth orbit. An unresolved issue for crewed deep space exploration involves limiting crew radiation exposure to below acceptable levels, considering both solar particle events and galactic cosmic ray contributions to dosage. Galactic cosmic ray mitigation is not addressed in this paper, but by addressing credible, easily implemented, and mass efficient solutions for the possibility of solar particle events, additional margin is provided that can be used for cosmic ray dose accumulation. As a result, NASA s Advanced Engineering Systems project office initiated this Radiation Storm Shelter design activity. This paper reports on the first year results of an expected 3 year Storm Shelter study effort which will mature concepts and operational scenarios that protect exploration astronauts from solar particle radiation events. Large trade space definition, candidate concept ranking, and a planned demonstration comprised the majority of FY12 activities. A system key performance parameter is minimization of the required increase in mass needed to provide a safe environment. Total system mass along with operational assessments and other defined protection system metrics provide the guiding metrics to proceed with concept developments. After a downselect to four primary methods, the concepts were analyzed for dosage severity and the amount of shielding mass necessary to bring dosage to acceptable values. Besides analytical assessments, subscale models of several concepts and one full scale concept demonstrator were created. FY12 work terminated with a plan to demonstrate test articles of two selected approaches. The process of arriving at these selections and their current envisioned implementation are presented in this paper.

Resistance of Feather-Associated Bacteria to Intermediate Levels of Ionizing Radiation near Chernobyl

OpenAIRE

Ruiz-Gonz?lez, Mario Xavier; Czirj?k, G?bor ?rp?d; Genevaux, Pierre; M?ller, Anders Pape; Mousseau, Timothy Alexander; Heeb, Philipp

2016-01-01

Ionizing radiation has been shown to produce negative effects on organisms, although little is known about its ecological and evolutionary effects. As a study model, we isolated bacteria associated with feathers from barn swallows Hirundo rustica from three study areas around Chernobyl differing in background ionizing radiation levels and one control study site in Denmark. Each bacterial community was exposed to four different ? radiation doses ranging from 0.46 to 3.96 kGy to test whether ch...

Interactive effects of solar radiation and dissolved organic matter on bacterial activity and community structure.

Science.gov (United States)

Pérez, María Teresa; Sommaruga, Ruben

2007-09-01

We studied the interactive effects of dissolved organic matter (DOM) and solar radiation on the activity and community structure of bacteria from an alpine lake. Activity was assessed both at the community level as leucine incorporation rates and at the single-cell level by microautoradiography. Fluorescent in situ hybridization and signal amplification by catalysed reporter deposition (CARD-FISH) was used to track changes in the bacterial community composition. Bacteria-free filtrates of different DOM sources (lake, algae or soil) were incubated either in the dark or exposed to solar radiation. Afterwards, the natural bacterial assemblage was inoculated and the cultures incubated in the dark for 24-48 h. Bacterial activity was enhanced in the first 24 h in the soil and algal DOM amendments kept in the dark. After 48 h, the enhancement effect was greatly reduced. The initial bacterial community was dominated by Betaproteobacteria followed by Actinobacteria. The relative abundance (expressed as a percentage of DAPI-stained cells) of Betaproteobacteria increased first in dark incubated DOM amendments, but after 48 h no significant differences were detected among treatments. In contrast, the relative abundance of Actinobacteria increased in pre-irradiated DOM treatments. Although Betaproteobacteria dominated at the end of the experiment, the relative abundance of their R-BT subgroup differed among treatments. Changes in bacterial community activity were significantly correlated with those of the relative abundance and activity of Betaproteobacteria, whereas the contribution of Actinobacteria to the bulk activity was very modest. Our results indicate a negative effect of DOM photoalteration on the bulk bacterial activity. The magnitude of this effect was time-dependent and related to rapid changes in the bacterial assemblage composition.

Radiation level analysis for the port cell of the ITER electron cyclotron-heating upper launcher

Energy Technology Data Exchange (ETDEWEB)

Weinhorst, Bastian, E-mail: bastian.weinhorst@kit.edu [KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Fischer, Ulrich; Lu, Lei [KIT, Institute for Neutron Physics and Reactor Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Strauss, Dirk; Spaeh, Peter; Scherer, Theo [KIT, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Leichtle, Dieter [F4E, Analysis & Codes/Technical Support Services, Josep Pla 2, Torres Diagonal Litoral B3, 08019 Barcelona (Spain)

2016-11-01

Highlights: • First detailed neutronic modelling of the ECHUL port cell with ECHUL equipment (including beam lines with diamond windows, the beam lines mounting box, conduit boxes and rails). • Three different bioshield port plug configurations and two different neutron source configurations are investigated. • Radiation Levels are calculated in the port cell, focusing on the position of the diamond window. • The dose rate in the port cell is below the limit for maintenance in the port cell. • The radiation level at the diamond window is very low and should not influence its performance. - Abstract: The electron cyclotron-heating upper launcher (ECHUL) will be installed in four upper ports of the ITER tokamak thermonuclear fusion reactor. Each ECHUL is able to deposit 8 MW power into the plasma for plasma mode stabilization via microwave beam lines. An essential part of these beam lines are the diamond windows. They are located in the upper port cell behind the bioshield to reduce the radiation levels to a minimum. The paper describes the first detailed neutronic modelling of the ECHUL port cell with ECHUL equipment. The bioshield plug is modelled including passageways for the microwave beam lines, piping and cables looms as well as rails and openings for ventilation. The port cell is equipped with the beam lines including the diamond windows, the beam lines mounting box, conduit boxes and rails. The neutrons are transported into the port cell starting from a surface source in front of the bioshield. Neutronic results are obtained for radiation levels in the port cell at different positions, mainly focusing on the diamond windows position. It is shown that the radiation level is below the limit for maintenance in the port cell. The radiation level at the diamond window is very low and should not influence its performance.

Assessment of environmental gamma radiation levels at locations having different source characteristics using TLDs

International Nuclear Information System (INIS)

Sahu, S.K.; Swarnkar, M.; Takale, R.A.; Shetty, P.G.; Pandit, G.G.; Puranik, V.D.

2012-01-01

Naturally occurring radionuclides are the major contributor to the total effective dose of ionizing radiation received by the population (UNSCEAR, 1993). The dose in environment thus depends largely on natural radiation than manmade or artificially produced radiation. In the last few decades, there is a growing concern all over the world about radiation and their exposure to population. Thus, it is a necessity to conduct frequent radiological environmental surveillance in order to assess population exposure accurately. Recently, application of thermoluminescence dosimeters (TLDs) has been extended to the measurement of mixed radiation field as encountered in the environment. The advantages of passive TL dosimeters for environmental monitoring are that they are small, cheap and do not require power supply during application. The passive TL dosimeters play an important role to provide data on natural background radiation and to determine the contribution to the dose to public from man-made sources. In the present study, three different sites were chosen to compare environmental gamma radiation levels in different scenarios. Kaiga has been chosen as site 1, where four unit of pressurized heavy water reactor (PHWR) of 220 MWe each are in operation. Site 2 is chosen at natural high background radiation area (NHBRA) of Kerala and Vishakhapatnam was chosen as site 3, which is situated at a normal background area. The objective of the study is to illustrate the effect, if any, of an operating nuclear power reactor on environmental gamma radiation levels

Development of an omnidirectional gamma-ray imaging Compton camera for low-radiation-level environmental monitoring

Science.gov (United States)

Watanabe, Takara; Enomoto, Ryoji; Muraishi, Hiroshi; Katagiri, Hideaki; Kagaya, Mika; Fukushi, Masahiro; Kano, Daisuke; Satoh, Wataru; Takeda, Tohoru; Tanaka, Manobu M.; Tanaka, Souichi; Uchida, Tomohisa; Wada, Kiyoto; Wakamatsu, Ryo

2018-02-01

We have developed an omnidirectional gamma-ray imaging Compton camera for environmental monitoring at low levels of radiation. The camera consisted of only six CsI(Tl) scintillator cubes of 3.5 cm, each of which was readout by super-bialkali photo-multiplier tubes (PMTs). Our camera enables the visualization of the position of gamma-ray sources in all directions (∼4π sr) over a wide energy range between 300 and 1400 keV. The angular resolution (σ) was found to be ∼11°, which was realized using an image-sharpening technique. A high detection efficiency of 18 cps/(µSv/h) for 511 keV (1.6 cps/MBq at 1 m) was achieved, indicating the capability of this camera to visualize hotspots in areas with low-radiation-level contamination from the order of µSv/h to natural background levels. Our proposed technique can be easily used as a low-radiation-level imaging monitor in radiation control areas, such as medical and accelerator facilities.

Study of Radiation Shielding Analysis for Low-Intermediate Level Waste Transport Ship

Energy Technology Data Exchange (ETDEWEB)

Kim, Dohyung; Lee, Unjang; Song, Yangsoo; Kim, Sukhoon; Ko, Jaehoon [Korea Nuclear Engineering and Service Corporation, Seoul (Korea, Republic of)

2007-07-01

In Korea, it is planed to transport Low-Intermediate Level Radioactive Waste (LILW) from each nuclear power plant site to Kyongju LILW repository after 2009. Transport through the sea using ship is one of the most prospective ways of LILW transport for current situation in Korea. There are domestic and international regulations for radiation dose limit for radioactive material transport. In this article, radiation shielding analysis for LILW transport ship is performed using 3-D computer simulation code, MCNP. As a result, the thickness and materials for radiation shielding walls next to cargo in the LILW transport ship are determined.

Epistemology of radiation protection

International Nuclear Information System (INIS)

Malcolm, C.

2010-01-01

The scientific committee had assess Status of levels, effects and risks of ionizing radiation for General assembly, scientific community and public. The review of levels, sources and exposures. The natural sources of radiation include cosmic rays, terrestrial and artificial sources include medical issues, military activities, civil nuclear power occupational exposure and accidents. The global average exposure is 80% natural source, 20% medical examination 0.2% weapon fallout < 0.1% cherbonyl accidents and < 0.1 nuclear power. The effects of radiation incudes health effects, hereditable effects, bystander effects, and abscopal effects. The randon risks include lancer risk, plant and animal

Overview of Twenty Years of Radiation and Tissue Banking Activity in Argentina

International Nuclear Information System (INIS)

Kairiyama, E.

2015-01-01

Radiation sterilization of human tissues in Argentina was a consequence of health care products sterilization by gamma radiation. Radiation technology was implemented in 1970 when the first multipurpose gamma facility was built at the Ezeiza Atomic Centre of CNEA. Organ and tissue transplantation is a well established effective therapy that saves lives and significantly improves the quality of life. Ionizing radiation is used for sterilization in order to provide clinically safe tissue for therapeutic purposes of implantation in every patient in need. Argentina radiation and tissue banking activity started in 1993 with the establishment of two tissue banks using radiation under the IAEA programme of technical cooperation, a skin bank and a bone one. Additionally to this start, other tissue banks have adopted tissue sterilization by irradiation. The compatible tissues sterilized with this methodology are mainly skin (frozen, glycerolized), bone (lyophilized, frozen), and amniotic membrane (glycerolized, frozen, dehydrated). The donation and transplant of human organ, tissue and cells is regulated and coordinated by the National Institute Unique Central Coordinator of Ablation and Implant (INCUCAI). In regards to radiation and nuclear safety, physical protection and nuclear non-proliferation issues are regulated and contorted by the Nuclear Regulatory Authority (ARN). Eight tissue banks use gamma radiation for sterilization of human tissues (6 musculoskeletal, 1 skin and 1 amniotic membrane). Argentina has participated actively in several IAEA projects regarding radiation and tissue banking program, and it has been selected by the IAEA to host the Regional Training Centre for the Latin American region. The following activities were implemented: regional training courses in Buenos Aires, face to face (five) and virtual (four) modalities; collaboration on several materials related to tissue banking and radiation sterilization of tissue allograft, codes of practice for

Active Radiative Thermal Switching with Graphene Plasmon Resonators.

Science.gov (United States)

Ilic, Ognjen; Thomas, Nathan H; Christensen, Thomas; Sherrott, Michelle C; Soljačić, Marin; Minnich, Austin J; Miller, Owen D; Atwater, Harry A

2018-03-27

We theoretically demonstrate a near-field radiative thermal switch based on thermally excited surface plasmons in graphene resonators. The high tunability of graphene enables substantial modulation of near-field radiative heat transfer, which, when combined with the use of resonant structures, overcomes the intrinsically broadband nature of thermal radiation. In canonical geometries, we use nonlinear optimization to show that stacked graphene sheets offer improved heat conductance contrast between "ON" and "OFF" switching states and that a >10× higher modulation is achieved between isolated graphene resonators than for parallel graphene sheets. In all cases, we find that carrier mobility is a crucial parameter for the performance of a radiative thermal switch. Furthermore, we derive shape-agnostic analytical approximations for the resonant heat transfer that provide general scaling laws and allow for direct comparison between different resonator geometries dominated by a single mode. The presented scheme is relevant for active thermal management and energy harvesting as well as probing excited-state dynamics at the nanoscale.

Investigation of environmental natural penetrating radiation level in Hubei Province

International Nuclear Information System (INIS)

Zhang Sihui; Zhang Jiaxian

1992-01-01

The methods and results of the investigation on natural penetrating radiation level in Hubei Province are presented, 290 measuring points of 25 x 25 km-grid were set uniformly up all over the province, with 385 densely measuring points of different types added. The results show that: (1) The area-weighted, population-weighted and point-weighted average value of natural γ radiation dose rate for field is 60.8, 58.5 and 60.9 nGy ·h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 55.3 nGy·h -1 ; (3) The population-weighted and point-weighed average value of natural γ radiation dose rate inside buildings is 94.5 and 93.2 x 10 nGy·h -1 , respectively; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 27.8 and 26.3 nGy·h -1 , and outside buildings is 31.8 and 30.4 nGy·h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside building is 121.0 and 120.7 nGy·h -1 , outside buildings is 92.8 and 88.9 nGy·h -1 , respectively; (6) The annual effective dose equivalent from cosmic ray, natural γ radiation and natural penetrating radiation is 0.24, 0.52 and 0.76 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 1.2, 2.5 and 3.7 x 10 4 man·Sv, respectively

Investigation of environmental natural penetrating radiation level in Heilongjiang Province

International Nuclear Information System (INIS)

Liu Yuncheng; Wu Chengxiang; Zhang Juling; Zhao Defeng

1994-01-01

The methods and results of the investigation on natural penetrating radiation level in Heilongjiang Province are presented. 221 25 km x 25 km-grid measuring points were set uniformly up all over the province, with 555 densely measuring points of different types added. The results show that: (1)The area-weighted, population-weighted and point-weighted average value of natural γ radiation dose rate for field is 53.5, 58.5 and 54.2 nGy·h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 58.4 nGy·h -1 ; (3) The population-weighted and point-weighted average value of natural γ radiation dose rate inside buildings is 85.2 and 78.9 nGy·h -1 , respectively; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 28.6 and 28.1 nGy·h -1 , and outside buildings is 32.4 and 32.2 nGy·h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 109.7 and 112.8 nGy·h -1 , outside buildings is 84.8 and 91.0 nGy·h -1 , respectively; (6) The annual effective dose equivalent from cosmic ray, natural γ radiation and natural penetrating radiation is 0.26, 0.48 and 0.73 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 0.8 x 10 4 , 1.6 x 10 4 and 2.4 x 10 4 man·Sv, respectively

Investigation of environmental natural penetrating radiation level in Jiangsu province

International Nuclear Information System (INIS)

Liu Ming; Wang Chengbao.

1993-01-01

The methods and results of in investigation on natural penetrating radiation level in Jiangsu Province are presented. 182 25 km x 25 km-grid measuring points were set up uniformly all over the province, with 236 densely measuring points of different types added. The results show that: (1) The area-weighted, population-weighted and point-weighted average value of natural γ radiation dose rate for field is 50.3, 50.6 and 50.4 nGy · h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 47.1 nGy · h -1 ; (3) The population-weighted and point-weighted average value of natural γ radiation dose rate inside buildings is 89.7 and 89.2 nGy · h -1 , respectively; (4) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 26.0 and 25.8 nGy · h -1 , and outside buildings is 29.2 and 29.1 nGy · h -1 , respectively; (5) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 115.1 and 115.5 nGy · h -1 , outside buildings is 79.5 and 79.7 nGy · h -1 , respectively; (6) The annual effective dose equivalent from cosmic ray, natural γ radiation and natural penetrating radiation is 0.23, 0.48 and 0.71 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 3.0, 1.5 and 4.5 x 10 4 man · Sv, respectively

Investigation of environmental natural penetrating radiation level in Shaanxi Province

International Nuclear Information System (INIS)

Zhang Chunfang; Li Jiyin

1994-01-01

The methods and results of the investigation on natural penetrating radiation level in Shaanxi Province are presented. 359 25 km x 25 km-grid measuring points were set uniformly up all over the province, with 433 densely measuring points of different types added. The results show that: (1) The area-weighted, population-weighted and point-weighted average value of natural γ radiation dose rate for field is 62.0, 63.0 and 61.0 nGy·h -1 , respectively; (2) The point-weighted average value of natural γ radiation dose rate for road is 63.0 nGy · h -1 ; (3)The population-weighted and point-weighted average value of natural γ radiation dose rate inside buildings is 100.0 and 98.0 nGy·h -1 , respectively; (4)The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 32.0 and 31.0 nGy·h -1 , and outside buildings is 37.0 and 36.0 nGy·h -1 , respectively; (5)The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 130.0 and 131.0 nGy·h -1 , outside buildings is 130.0 and 130.0 nGy·h -1 , respectively; (6)The annual effective dose equivalent from cosmic ray, natural γ radiation and natural penetrating radiation is 0.55, 0.28 and 0.83 mSv, respectively; and correspondingly, the annual collective effective dose equivalent is 1.63, 0.83 and 2.46 x 10 4 man·Sv, respectively

Modulation of DNA methylation levels sensitizes doxorubicin-resistant breast adenocarcinoma cells to radiation-induced apoptosis

Energy Technology Data Exchange (ETDEWEB)

Luzhna, Lidia [Department of Biological Sciences, University of Lethbridge, AB, Canada T1K 3M4 (Canada); Kovalchuk, Olga, E-mail: olga.kovalchuk@uleth.ca [Department of Biological Sciences, University of Lethbridge, AB, Canada T1K 3M4 (Canada)

2010-02-05

Chemoresistant tumors often fail to respond to other cytotoxic treatments such as radiation therapy. The mechanisms of chemo- and radiotherapy cross resistance are not fully understood and are believed to be epigenetic in nature. We hypothesize that MCF-7 cells and their doxorubicin-resistant variant MCF-7/DOX cells may exhibit different responses to ionizing radiation due to their dissimilar epigenetic status. Similar to previous studies, we found that MCF-7/DOX cells harbor much lower levels of global DNA methylation than MCF-7 cells. Furthermore, we found that MCF-7/DOX cells had lower background apoptosis levels and were less responsive to radiation than MCF-7 cells. Decreased radiation responsiveness correlated to significant global DNA hypomethylation in MCF-7/DOX cells. Here, for the first time, we show that the radiation resistance of MCF-7/DOX cells can be reversed by an epigenetic treatment - the application of methyl-donor SAM. SAM-mediated reversal of DNA methylation led to elevated radiation sensitivity in MCF-7/DOX cells. Contrarily, application of SAM on the radiation sensitive and higher methylated MCF-7 cells resulted in a decrease in their radiation responsiveness. This data suggests that a fine balance of DNA methylation is needed to insure proper radiation and drug responsiveness.

Measurement of the solar ultraviolet radiation at ground level in Bangi, Malaysia

Energy Technology Data Exchange (ETDEWEB)

Aljawi, Ohoud; Gopir, Geri; Duay, Abdul Basit [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia. ohoud-aljawi@hotmail.com (Malaysia)

2015-04-24

Understanding the amount of ultraviolet (UV) radiation received by human, plant, and animal organisms near the earth’s surface is important to a wide range of fields such as cancer research, agriculture and forestry. The solar ultraviolet spectral irradiance at ground level was measured using the Avantes spectrometer for the period of January to March 2014 at Bangi (2°55´N, 101°46´E, 50 m above sea level) in Malaysia. These data were used to estimate the diurnal variation of UV irradiance (300 – 400 nm). The maximum irradiance of UV radiation was 45 W m{sup −2} on horizontal surface. The maximum irradiance of UV received in the local noon time, and the minimum values of UV irradiance was received in the local morning time. It is found a bigger value of UV radiation was observed on clear sky in January. The estimation of daily flux average of UV irradiance was (921± 91) kJ m{sup −2}.

Research in radiation biology, in the environment, and in radiation protection at CRNL

International Nuclear Information System (INIS)

Marko, A.M.; Myers, D.K.; Ophel, I.L.; Cowper, G.; Newcombe, H.B.

1978-01-01

Research in radiation biology at CRNL is concerned with: evaluation of the effects of low doses of radiation upon humans and other living organisms; the development of new methods for detecting the effects of radiation exposure in large populations; the continued development of improved methods by which radiation levels can be measured accurately and reliably; and evaluation of the effects of nuclear power use upon the environment. The present report summarizes our background knowledge of radiation hazards and describes current research activities in Biology and Health Physics Division at CRNL. (author)

The Australasian radiation protection society's position statement on risks from low levels of ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Don, Higson; Ches, Mason; Andrew, McEwan; Peter, Burns; Riaz, Akber; Ron, Cameron; Pamela, Sykes; Joe, Young [Australasian Radiation Protection Society (Australia)

2006-07-01

At its Annual General Meeting in 2004, the Australasian Radiation Protection Society (A.R.P.S.) set up a working group to draft a statement of the Society's position on risks from low levels of exposure to ionizing radiation. The resulting position statement was adopted by the Society at its Annual General Meeting in 2005. Its salient features are as follows: First, there is insufficient evidence to establish a dose-effect relationship for doses that are less than a few tens of milli sieverts in a year. A linear extrapolation from higher dose levels should be assumed only for the purpose of applying regulatory controls. Secondly, estimates of collective dose arising from individual doses that are less than some tens of milli sieverts in a year should not be used to predict numbers of fatal cancers. Thirdly, the risk to an individual of doses significantly less than 100 micro sieverts in a year is so small, if it exists at all, that regulatory requirements to control exposure at this level are not warranted. (authors)

Tradescantia in studies of genetic effects of low level radiation

International Nuclear Information System (INIS)

Yamashita, Atsushi

1976-01-01

Tradescantia in studies on genetic effects of low level radiation is briefly introduced. Radiosensitivity, method of screening stamen hair mutation, materials in current uses, spontaneous mutation rate, and modifying factors are refered. For stamen hair mutation b values in exponential model were lower in irradiation with low dose rate at high environmental temperature. The dose response curves under these modifying conditions, when extrapolated to low dose range, well fit to the line which was obtained by Sparrow's experiment of low level irradiation. In chronic irradiation, the frequency of stamen hair mutation reaches to the constant value after 17 days from the start of irradiation, and is as much as 4 times higher than the peak value in one day irradiation at the same exposure rate. The spontaneous mutation rate of KU-7 varied with temperature. The increase with 1 0 C increment of mean temperature was -0.04%. Uses of Tradescantia in monitoring the environmental radiation is discussed. (auth.)

[Level of microwave radiation from mobile phone base stations built in residential districts].

Science.gov (United States)

Hu, Ji; Lu, Yiyang; Zhang, Huacheng; Xie, Hebing; Yang, Xinwen

2009-11-01

To investigate the condition of microwave radiation pollution from mobile phone base station built in populated area. Random selected 18 residential districts where had base station and 10 residential districts where had no base stations. A TES-92 electromagnetic radiation monitor were used to measure the intensity of microwave radiation in external and internal living environment. The intensities of microwave radiation in the exposure residential districts were more higher than those of the control residential districts (p station, it would gradually weaken with the increase of the distance. The level of microwave radiation in antenna main lobe region is not certainly more higher than the side lobe direction, and the side lobe direction also is not more lower. At the same district, where there were two base stations, the electromagnetic field nestification would take place in someplace. The intensities of microwave radiation outside the exposure windows in the resident room not only changed with distance but also with the height of the floor. The intensities of microwave radiation inside the aluminum alloys security net were more lower than those of outside the aluminum alloys security net (p 0.05). Although all the measure dates on the ground around the base station could be below the primary standard in "environment electromagnetic wave hygienic standard" (GB9175-88), there were still a minorities of windows which exposed to the base station were higher, and the outside or inside of a few window was even higher beyond the primary safe level defined standard. The aluminum alloys security net can partly shield the microwave radiation from the mobile phone base station.

Perception of radiation hazards

International Nuclear Information System (INIS)

Sorenson, J.A.

1986-01-01

The health risks of radiation have been carefully studied and are relatively well understood in comparison with other risks to the human environment. Public perception of these risks often is distorted, due in part to lack of familiarity with the actual risk levels involved. There is a need for dissemination to the public of accurate information on radiation risks as well as to patients and volunteer subjects for studies involving radiation exposures. Often such information can be presented meaningfully by comparing the risks of radiation exposure with other, more familiar risks. Natural background radiation is a universally present and generally accepted source of risk, and thus serves as one reference against which to compare the risks of other radiation exposures. Natural background radiation averages about 100 mrem/yr, but much higher levels are encountered in some parts of the US (400 mrem/yr) and worldwide (2000 mrem/yr). These variations are due primarily to differences in cosmic ray intensity with altitude and in terrestrial radiation originating from soil and rocks. Radiation risks also may be compared with the risks of other human activities, both voluntary and involuntary. The former are useful for comparisons with the risks of voluntary radiation exposures such as occupational exposure and participation in medical or research procedures involving radiation. Involuntary radiation exposure, such as might result from the transportation and disposal of radioactive waste, poses a more complicated issue. Comparisons of such exposures to natural background radiation levels and their variations are helpful. Two other concepts that have been proposed for assessing the relative risk of low-level radiation exposure are de minimus risk and probability of causation. 28 references

The radiation protection programme activities of the World Health Organization

International Nuclear Information System (INIS)

Komarov, E.; Suess, M.J.

1980-01-01

The radiation protection activities of the World Health Organization are reviewed. They include studies of radiation protection standards and guidelines, and public health aspects of nuclear power. WHO also provides member states with world data on radioactivity in air, water and food, and assessments of population exposure and health effects. (H.K.)

Ambient radiation levels in a microPET/CT research laboratory

Energy Technology Data Exchange (ETDEWEB)

Sarmento, D.M.; Rodrigues, D.L.; Sanches, M.P.; Carneiro, J.C.G.G., E-mail: janetegc@ipen.br [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

This study focuses on initial radiological evaluation and the exposure situation related to the worker task in a micro-positron emission tomography/computed tomography laboratory (microPET/CT). Selected and calibrated thermoluminescent dosimeters, TLD, of CaSO{sub 4}:Dy were used to measure room radiation levels. The detectors were placed in several selected points inside the microPET/CT laboratory and adjacent rooms. In addition, the occupationally exposed workers were monthly evaluated for external and internal exposures. In none of the selected points the dose values exceeded the radiation dose limit established for supervised area, as well as the values obtained in individual monitoring. (author)

Ambient radiation levels in a microPET/CT research laboratory

International Nuclear Information System (INIS)

Sarmento, D.M.; Rodrigues, D.L.; Sanches, M.P.; Carneiro, J.C.G.G.

2015-01-01

This study focuses on initial radiological evaluation and the exposure situation related to the worker task in a micro-positron emission tomography/computed tomography laboratory (microPET/CT). Selected and calibrated thermoluminescent dosimeters, TLD, of CaSO 4 :Dy were used to measure room radiation levels. The detectors were placed in several selected points inside the microPET/CT laboratory and adjacent rooms. In addition, the occupationally exposed workers were monthly evaluated for external and internal exposures. In none of the selected points the dose values exceeded the radiation dose limit established for supervised area, as well as the values obtained in individual monitoring. (author)

Investigation of environmental natural penetrating radiation level in Hebei province

International Nuclear Information System (INIS)

Zheng Deliang; Wang Shuming; Yang Huanfeng

1990-01-01

The methods and results of the investigation on natural penetrating radiation level in Hebei Province from 1985 to 1987 are presented. 285 25 x 25 km-netted measuring points were set unformly up all over the porvince, with 204 densely measuring points of different types added. The results show that: (1) The point-weighted, area-weighted and population-weighted average value of natural γ radiation dose rate for field is 5.59, 5.51 and 5.31 x 10 -8 Gy·h -1 , respectively; (2) The point-weighted and population-weighted average value of the dose rate inside buildings from cosmic ray is 3.05 and 2.80 x 10 -8 Gy·h -1 , and outside buildings is 3.38 and 3.11 x 10 -8 Gy·h -1 , respectively; (3) The point-weighted and population-weighted average value of natural penetrating radiation dose rate inside buildings is 12.44 and 11.97 x 10 -8 Gy·h -1 , outside buildings is 8.97 and 8.42 x 10 -8 Gy·h -1 , respectively; (4) The annual effective dose equivalent from natural γ radiation, cosmic ray and natural penetrating radiation is 0.50, 0.25, and 0.75 mSv, respectively; and correspondingly, the annual collective effectiv dose equivalent is 2.7, 1.3 and 4.0 x 10 4 man·Sv, respectively

Long distance elementary measurement of the radiation dose ratio produced by neutron activation

International Nuclear Information System (INIS)

Zhou Changgeng; Lou Benchao; Wu Chunlei; Hu Yonghong; Li Yan

2009-04-01

The working principle and the structure and performances of a long distance controllable individual radiation dose ratio instrument are described. The radiation dose ratio produced by neutron activation is elementarily measured by using this instrument in the neutron generator hall with high neutron yield. When neutron yield arrives to 2 x 10 11 s -1 , the radiation dose ratio produced by neutron activation is 99.9 μSv/h in 1 h after the generator being stopped. The radiation dose ratio is reduced to 24.4 μSv/h in 39 h after the generator being stopped. When neutron yield is 3.2 x 10 10 s -1 , the radiation dose ratio produced by neutron activation is 21.9 μSv/h in 36 min, after the generator being stopped. The measurement results may provide reference for physical experimenters and neutron generator operators. (authors)

Radiation-induced bistable centers with deep levels in silicon n{sup +}–p structures

Energy Technology Data Exchange (ETDEWEB)

Lastovskii, S. B., E-mail: lastov@ifttp.bas-net.by [Scientific and Practical Materials Research Center of the National Academy of Sciences of Belarus (Belarus); Markevich, V. P. [Manchester University, Photon Science Institute (United Kingdom); Yakushevich, H. S.; Murin, L. I. [Scientific and Practical Materials Research Center of the National Academy of Sciences of Belarus (Belarus); Krylov, V. P. [Vladimir State University (Russian Federation)

2016-06-15

The method of deep level transient spectroscopy is used to study electrically active defects in p-type silicon crystals irradiated with MeV electrons and α particles. A new radiation-induced defect with the properties of bistable centers is determined and studied. After keeping the irradiated samples at room temperature for a long time or after their short-time annealing at T ∼ 370 K, this defect does not display any electrical activity in p-type silicon. However, as a result of the subsequent injection of minority charge carriers, this center transforms into the metastable configuration with deep levels located at E{sub V} + 0.45 and E{sub V} + 0.54 eV. The reverse transition to the main configuration occurs in the temperature range of 50–100°C and is characterized by the activation energy ∼1.25 eV and a frequency factor of ∼5 × 10{sup 15} s{sup –1}. The determined defect is thermally stable at temperatures as high as T ∼ 450 K. It is assumed that this defect can either be a complex of an intrinsic interstitial silicon atom with an interstitial carbon atom or a complex consisting of an intrinsic interstitial silicon atom with an interstitial boron atom.

Scale dependence of absorption of photosynthetically active radiation in terrestrial ecosystems

International Nuclear Information System (INIS)

Asner, G.P.; Wessman, C.A.; Archer, S.

1998-01-01

The fraction of photosynthetically active radiation absorbed by plant canopies (fAPAR) is a critical biophysical variable for extrapolating ecophysiological measurements from the leaf to landscape scale. Quantification of fAPAR determinants at the landscape level is needed to improve the interpretation of remote sensing data, to facilitate its use in constraining ecosystem process models, and to improve synoptic-scale links between carbon and nutrient cycles. Most canopy radiation budget studies have focused on light attenuation in plant canopies, with little regard for the importance of the scale-dependent biophysical and structural factors (e.g., leaf and stem optical properties, leaf and stem area, and extent of vegetation structural types) that ultimately determine fAPAR at canopy and landscape scales. Most studies have also assumed that nonphotosynthetic vegetation (litter and stems) contributes little to fAPAR. Using a combined field measurement and radiative transfer modeling approach, we quantified (a) the relative role of the leaf-, canopy-, and landscape-level factors that determine fAPAR in terrestrial ecosystems and (b) the magnitude of PAR absorption by grass litter and woody plant stems. Variability in full spectral-range (400–2500 nm) reflectance/transmittance and PAR (400–700 nm) absorption at the level of individual leaf, stem, and litter samples was quantified for a wide array of broadleaf arborescent and grass species along a 900-km north–south Texas savanna transect. Among woody growth forms, leaf reflectance and transmittance spectra were statistically comparable between populations, species within a genus, and functional types (deciduous vs. evergreen, legume vs. nonlegume). Within the grass life-form, spectral properties were statistically comparable between species and C 3 /C 4 physiologies. We found that tissue-level PAR absorption among species, genera, functional groups, and growth forms and between climatologically diverse regions

Radiation effects in glass waste forms for high-level waste and plutonium disposal

International Nuclear Information System (INIS)

Weber, W.J.; Ewing, R.C.

1997-01-01

A key challenge in the permanent disposal of high-level waste (HLW), plutonium residues/scraps, and excess weapons plutonium in glass waste forms is the development of predictive models of long-term performance that are based on a sound scientific understanding of relevant phenomena. Radiation effects from β-decay and α-decay can impact the performance of glasses for HLW and Pu disposition through the interactions of the α-particles, β-particles, recoil nuclei, and γ-rays with the atoms in the glass. Recently, a scientific panel convened under the auspices of the DOE Council on Materials Science to assess the current state of understanding, identify important scientific issues, and recommend directions for research in the area of radiation effects in glasses for HLW and Pu disposition. The overall finding of the panel was that there is a critical lack of systematic understanding on radiation effects in glasses at the atomic, microscopic, and macroscopic levels. The current state of understanding on radiation effects in glass waste forms and critical scientific issues are presented

Soybean growth responses to enhanced levels of ultraviolet-B radiation under greenhouse conditions

International Nuclear Information System (INIS)

Teramura, A.H.; Sullivan, J.H.

1987-01-01

Soybean (Glycine max [L.] Merr. cv. Essex) was grown in an unshaded greenhouse under three levels of biologically effective ultraviolet-B (UV-BBE) radiation (effective daily dose: 0, 11.5 and 13.6 kJ m -2 ) for 91 days. Plants were harvested at regular intervals beginning 10 days after germination until reproductive maturity. Mathematical growth analysis revealed that the effects of UV-B radiation varied with plant growth stage. The transition period between vegetative and reproductive growth was the most sensitive to UV-B radiation. Intermediate levels of UV-B had deleterious effects on plant height, leaf area, and total plant dry weight at late vegetative and reproductive stages of development. Specific leaf weight increased during vegetative growth but was unaffected by UV-B during reproductive growth stages. Relative growth, net assimilation, and stem elongation rates were decreased by UV-B radiation during vegetative and early reproductive growth stages. Variation in plant responses may be due in part to changes in microclimate within the plant canopy or to differences in repair or protection mechanisms at differing developmental stages. (author)

γ radiation effects on Collembola

International Nuclear Information System (INIS)

Loring, S.J.

1985-01-01

Pitfall traps were used to collect surface-active Collembola at intervals of 10-100 m from a γ radiation source on Long Island, N.Y., during the summer of 1968. Thirty-two species of Collembola were collected along the radiation transect. Community diversities were similar at all intervals except 10 m. Collembola appeared resistant to γ radiation; only chronic, very high γ radiation exposure seriously affected population levels and community diversity of surface Collembola

Monolithic active pixel radiation detector with shielding techniques

Energy Technology Data Exchange (ETDEWEB)

Deptuch, Grzegorz W.

2018-03-20

A monolithic active pixel radiation detector including a method of fabricating thereof. The disclosed radiation detector can include a substrate comprising a silicon layer upon which electronics are configured. A plurality of channels can be formed on the silicon layer, wherein the plurality of channels are connected to sources of signals located in a bulk part of the substrate, and wherein the signals flow through electrically conducting vias established in an isolation oxide on the substrate. One or more nested wells can be configured from the substrate, wherein the nested wells assist in collecting charge carriers released in interaction with radiation and wherein the nested wells further separate the electronics from the sensing portion of the detector substrate. The detector can also be configured according to a thick SOA method of fabrication.

Radiation studies on the microflora in a High-level radiation environment

International Nuclear Information System (INIS)

Zahiera, T.S.

1988-01-01

Radiation sensitivities of microflora in the air environment of the irradiation room of the 60 CO industrial irradiation facility of NCRRT was studied. The isolated microflora was identified to be the Gram positive micrococci, and the gram positive bacilli: coagulans and laterosporous. The study of the dose-survival counts dependence of the colonies showed the existance of the combination of at least two groups of micro-organisms with different sensitivities to radiation. The value of the radiation resistant group was found to be 2.2 10kGy. A method is presented to estimate the amount of each group in the initial culture. A study of the dependence of radiation lethality on the dose rate of radiation on the aerobic dry microbes showed no significant effect in the dose-rate range from 330 down to 44 Gy.min

The Australasian radiation protection society's position statement on risks fro low levels of ionizing radiation

International Nuclear Information System (INIS)

Higson, D.J.

2006-01-01

Full text: Controversy continues in the radiation protection literature on whether or not ionizing radiation is harmful at low doses, with unresolved scientific uncertainty about effects below a few tens of millisieverts. To settle what regulatory controls (if any) should apply in this dose region, an assumption has to be made relating dose to the possibility of harm or benefit. The assumption made and the way it is applied can have far-reaching effects, not only on the scale of regulatory compliance required but also on public perception of risk, and therefore on the technological choices made by society. It is important therefore that decisions reached concerning the regulation of low doses of ionizing radiation derive from rational arguments and are perceived to have an ethical basis. It is also important that such decisions are neither portrayed nor perceived as resolving the scientific uncertainties: rather, they serve merely to facilitate the implementation of appropriate measures to ensure safety. At its Annual General Meeting in 2004, the Australasian Radiation Protection Society (ARPS) set up a working group to draft a statement of the Society's position on this matter. The resulting position statement was adopted by the Society at its Annual General Meeting on 14 November 2005. Its salient features are as follows: There is insufficient evidence to establish a dose-effect relationship for doses that are less than a few tens of millisieverts in a year. A linear extrapolation from higher dose levels should be assumed only for the purpose of applying regulatory controls; Estimates of collective dose arising from individual doses that are less than some tens of millisieverts in a year should not be used to predict numbers of fatal cancers; The risk to an individual of doses significantly less than 100 microsieverts in a year is so small, if it exists at all, that regulatory requirements to control exposure at this level are not warranted. The paper will