The Effects of Ionizing Radiation on the Oral Cavity.

Science.gov (United States)

de Barros da Cunha, Sandra Ribeiro; Ramos, Pedro Augusto Mendes; Nesrallah, Ana Cristina Aló; Parahyba, Cláudia Joffily; Fregnani, Eduardo Rodrigues; Aranha, Ana Cecília Corrêa

2015-08-01

The aim of this study is to present a literature review on the effects of the ionizing radiation from radiotherapy treatment on dental tissues. Among the effects of increasing global life expectancy and longevity of the teeth in the oral cavity, increasing rates of neoplastic diseases have been observed. One of the important treatment modalities for head and neck neoplastic diseases is radiotherapy, which uses ionizing radiation as the main mechanism of action. Therefore, it is essential for dentists to be aware of the changes in oral and dental tissues caused by ionizing radiation, and to develop treatment and prevention strategies. In general, there is still controversy about the effects of ionizing radiation on dental structures. However, qualitative and quantitative changes in saliva and oral microbiota, presence of oral mucositis and radiation-related caries are expected, as they represent the well-known side effects of treatment with ionizing radiation. Points that still remain unclear are the effects of radiotherapy on enamel and dentin, and on their mechanisms of bonding to contemporary adhesive materials. Ionizing radiation has shown important interaction with organic tissues, since more deleterious effects have been shown on the oral mucosa, salivary glands and dentin, than on enamel. With the increasing number of patients with cancer seeking dental treatment before and after head and neck radiotherapy, it is important for dentists to be aware of the effects of ionizing radiation on the oral cavity.

Foundations of ionizing radiation dosimetry

International Nuclear Information System (INIS)

Denisenko, O.N.; Pereslegin, I.A.

1985-01-01

Foundations of dosimetry in application to radiotherapy are presented. General characteristics of ionizing radiations and main characteristics of ionizing radiation sources, mostly used in radiotherapy, are given. Values and units for measuring ionizing radiation (activity of a radioactive substance, absorbed dose, exposure dose, integral dose and dose equivalent are considered. Different methods and instruments for ionizing radiation dosimetry are discussed. The attention is paid to the foundations of clinical dosimetry (representation of anatomo-topographic information, choice of radiation conditions, realization of radiation methods, corrections for a configuration and inhomogeneity of a patient's body, account of biological factors of radiation effects, instruments of dose field formation, control of irradiation procedure chosen)

What is ''ionizing radiation''?

International Nuclear Information System (INIS)

Tschurlovits, M.

1997-01-01

The scientific background of radiation protection and hence ''ionizing radiation'' is undergoing substantial regress since a century. Radiations as we are concerned with are from the beginning defined based upon their effects rather than upon the physical origin and their properties. This might be one of the reasons why the definition of the term ''ionizing radiation'' in radiation protection is still weak from an up to date point of view in texts as well as in international and national standards. The general meaning is unambiguous, but a numerical value depends on a number of conditions and the purpose. Hence, a clear statement on a numerical value of the energy threshold beyond a radiation has to be considered as ''ionizing'' is still missing. The existing definitions are, therefore, either correct but very general or theoretical and hence not applicable. This paper reviews existing definitions and suggests some issues to be taken into account for possible improvement of the definition of ''ionizing radiation''. (author)

Ionizing radiation

International Nuclear Information System (INIS)

Dennis, J.A.

1982-01-01

The subject is discussed under the headings: characteristics of ionizing radiations; biological effects; comparison of radiation and other industrial risks; principles of protection; cost-benefit analysis; dose limits; the control and monitoring of radiation; reference levels; emergency reference levels. (U.K.)

Improved Intratumoral Oxygenation Through Vascular Normalization Increases Glioma Sensitivity to Ionizing Radiation

International Nuclear Information System (INIS)

McGee, Mackenzie C.; Hamner, J. Blair; Williams, Regan F.; Rosati, Shannon F.; Sims, Thomas L.; Ng, Catherine Y.; Gaber, M. Waleed; Calabrese, Christopher; Wu Jianrong; Nathwani, Amit C.; Duntsch, Christopher; Merchant, Thomas E.; Davidoff, Andrew M.

2010-01-01

Purpose: Ionizing radiation, an important component of glioma therapy, is critically dependent on tumor oxygenation. However, gliomas are notable for areas of necrosis and hypoxia, which foster radioresistance. We hypothesized that pharmacologic manipulation of the typically dysfunctional tumor vasculature would improve intratumoral oxygenation and, thus, the antiglioma efficacy of ionizing radiation. Methods and Materials: Orthotopic U87 xenografts were treated with either continuous interferon-β (IFN-β) or bevacizumab, alone, or combined with cranial irradiation (RT). Tumor growth was assessed by quantitative bioluminescence imaging; the tumor vasculature using immunohistochemical staining, and tumor oxygenation using hypoxyprobe staining. Results: Both IFN-β and bevaziumab profoundly affected the tumor vasculature, albeit with different cellular phenotypes. IFN-β caused a doubling in the percentage of area of perivascular cell staining, and bevacizumab caused a rapid decrease in the percentage of area of endothelial cell staining. However, both agents increased intratumoral oxygenation, although with bevacizumab, the effect was transient, being lost by 5 days. Administration of IFN-β or bevacizumab before RT was significantly more effective than any of the three modalities as monotherapy or when RT was administered concomitantly with IFN-β or bevacizumab or 5 days after bevacizumab. Conclusion: Bevacizumab and continuous delivery of IFN-β each induced significant changes in glioma vascular physiology, improving intratumoral oxygenation and enhancing the antitumor activity of ionizing radiation. Additional investigation into the use and timing of these and other agents that modify the vascular phenotype, combined with RT, is warranted to optimize cytotoxic activity.

Tissue macrophage activation: a shared sign of exposure to ionizing and non-ionizing radiation

International Nuclear Information System (INIS)

Petrenyov, D.R.

2012-01-01

The features of oxidative metabolism of peritoneal macrophages were studied in rats exposed to ionizing and non-ionizing radiation. An increased RNS and ROS production reported in animals exposed to both source of radiation showing non-specific response of organism. (authors)

Influence of beryllium ceramics nano-structuring by iron atoms on increase of their stability to ionizing radiations effect

International Nuclear Information System (INIS)

Polyakov, A.I.; Bitenbaev, M.I

2007-01-01

In the work a new results on beryllium ceramics nano-structuring effect by iron oxide atoms on radiation defects quantum yield value G in these materials and defects depth constants in ionizing radiation fields k are presented. Experimental data under dependence of G and k values from concentration of iron atoms in beryllium ceramic matrix are presented. It is shown, that structure modification of beryllium ceramics by feedings on the iron base leads to sharp decrease (almost in 30 times) of radiation defects quantum yield value, i.e. to increase of these ceramics stability enhancement to ionizing radiation effect

Modern state of the application of ionizing radiation for protection of environment. 1. Ionizing radiation sources. Purification of natural and drinking water (review)

International Nuclear Information System (INIS)

Pikaev, AK.

2000-01-01

Review of modern state of the application of ionizing radiations for protection of environment and natural and drinking water purification is presented. Building of installations with electron accelerators with summarized power of beam ∼0.6 MW signifies that application of ionizing radiation for ecological needs increase. It is pointed out that extensible application of electron accelerators is explained by their safety and efficiency as compared with gamma-sources. New information about ionizing radiation sources, radiation-chemical purification of polluted natural and drinking water, mechanisms of processes taking place during treatment by ionizing radiations are generalized [ru

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

Optical Imaging of Ionizing Radiation from Clinical Sources.

Science.gov (United States)

Shaffer, Travis M; Drain, Charles Michael; Grimm, Jan

2016-11-01

Nuclear medicine uses ionizing radiation for both in vivo diagnosis and therapy. Ionizing radiation comes from a variety of sources, including x-rays, beam therapy, brachytherapy, and various injected radionuclides. Although PET and SPECT remain clinical mainstays, optical readouts of ionizing radiation offer numerous benefits and complement these standard techniques. Furthermore, for ionizing radiation sources that cannot be imaged using these standard techniques, optical imaging offers a unique imaging alternative. This article reviews optical imaging of both radionuclide- and beam-based ionizing radiation from high-energy photons and charged particles through mechanisms including radioluminescence, Cerenkov luminescence, and scintillation. Therapeutically, these visible photons have been combined with photodynamic therapeutic agents preclinically for increasing therapeutic response at depths difficult to reach with external light sources. Last, new microscopy methods that allow single-cell optical imaging of radionuclides are reviewed. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Protection policies for ionizing and UV radiation

International Nuclear Information System (INIS)

Bosnjakovic, B.F.M.

1987-01-01

Although ultraviolet radiation is generally considered as being part of non-ionizing radiation, the existing similarities with ionizing radiation are too striking to be overseen. A comparison of these two agents is becoming important in view of the increasing awareness of various environmental and health risks and the tendency to develop more uniform risk management policies with respect to the different physical and chemical agents. This paper explores the similarities and differences of UV and ionizing radiation from the point of view of policies either adopted or in development. Policy determinants include, among others, the following factors: biological effects, dosimetric quantities, relative contribution to exposure from different sources, hazard potential of different sources, quantification of detrimental consequences, public perception of the radiation hazards and regulation developments. These factors are discussed

Health effects of ionizing radiation

International Nuclear Information System (INIS)

Pathak, B.

1989-12-01

Ionizing radiation is energy that travels through space as electromagnetic waves or a stream of fast moving particles. In the workplace, the sources of ionizing radiation are radioactive substances, nuclear power plants, x-ray machines and nuclear devices used in medicine, research and industry. Commonly encountered types of radiation are alpha particles, beta particles and gamma rays. Alpha particles have very little penetrating power and pose a risk only when the radioactive substance is deposited inside the body. Beta particles are more penetrating than alpha particles and can penetrate the outer body tissues causing damage to the skin and the eyes. Gamma rays are highly penetrating and can cause radiation damage to the whole body. The probability of radiation-induced disease depends on the accumulated amount of radiation dose. The main health effects of ionizing radiation are cancers in exposed persons and genetic disorders in the children, grandchildren and subsequent generations of the exposed parents. The fetus is highly sensitive to radiation-induced abnormalities. At high doses, radiation can cause cataracts in the eyes. There is no firm evidence that ionizing radiation causes premature aging. Radiation-induced sterility is highly unlikely for occupational doses. The data on the combined effect of ionizing radiation and other cancer-causing physical and chemical agents are inconclusive

Possibilities to reduce the effect of ionizing radiation by interaction of two types of radiation into a matter: ionized and non-ionized radiation

International Nuclear Information System (INIS)

Tanvir

2007-01-01

Full text: At present it has been accepted that ionized radiation can cause biological effects on the human body and the only way of preventing this effect, is by shielding the source of radiation by absorbing materials. On the other hand, the technology of non-ionizing radiation is upgraded. The canalization of radiation through the wave-guide based structures and optical fiber is well established. This reminds us that passing through benzene non-ionized radiation give the 'Raman' effect, which can ensure the secondary generation of non-ionized radiation with the wave length of nanometer and so far. These types of non-ionized radiation can easily be correlated with the gamma radiation, which is ionized. We know that high-energized photon usually interacts with matter and reduces its energy to the matter and generate electro-magnetic waves into the molecules of the matter. It is also well known that through the wave-guide based structures and optical fiber; the path of energy distribution of photon is likely to be optical energetic modes. If two types of photon from two types of radiation (ionized and non-ionized) interact with matter and pass through the optical fiber, they can generate optical modes with various wavelengths and phase velocities. With 'Raman' effect we can generate secondary electromagnetic waves of nanometer; as well as optical modes into the optical fiber. These optical modes from two types of radiation with various phase velocities, having the similar wavelength, can decrease or accelerate some modes. On the view of signal distribution, we can assume that if two similar signals pass through the circuit with phase difference 180P 0 P, then the result posses no signal. We are also reminded that photon of γ - radiation can spread from 0 deg. to 180 deg. C, where the 'Compton' loss of radiation is minimum. In view of the electro-magnetic theory of Maxwell we can assume the energetic field of optical modes, which are generated into the optical

Biology of ionizing radiation effects

International Nuclear Information System (INIS)

Ferradini, C.; Pucheault, J.

1983-01-01

The present trends in biology of ionizing radiation are reviewed. The following topics are investigated: interaction of ionizing radiations with matter; the radiolysis of water and aqueous solutions; properties of the free radicals intervening in the couples O 2 /H 2 O and H 2 O/H 2 ; radiation chemistry of biological compounds; biological effects of ionizing radiations; biochemical mechanisms involving free radicals as intermediates; applications (biotechnological applications, origins of life) [fr

Review Ionizing Radiation In The Environment

International Nuclear Information System (INIS)

Hassan, K.M.

2007-01-01

Our environment is pervaded by ionizing radiation of natural origin including terrestrial radionuclides and extra-terrestrial sources but man's activities can increase radiation levels by acting on natural sources or by producing artificial radionuclides. The energy released by radionuclides can be measured. The amount of energy generated in our bodies from the radioactive decay of within- body radionuclides is called internal dose. External dose results from gamma rays emitted by terrestrial sources such as the ground, building materials and from extraterrestrial sources. The major contributors to human exposure are radon and its daughters in the air that we breathe. Ionizing radiation can penetrate into matter and thus, causing damage by interacting with the atoms and molecules of the medium. If the medium is living tissue, damage to cells can take place. Very large doses of radiation will result in serious tissue, damage that may lead to death of the organism. Lower doses may also be harmful and do not cause the immediate damage of high doses but instead act to increase the likelihood of developing cancer. So, exposure to ionizing radiation can have health consequences, which is why we are concerned about and, to a large extent, is why this review paper was written. Exposure to ionizing radiation should be kept as minimum as practically possible. People are advised to monitor the concentrations of radon in their houses. In addition, the levels of radionuclides in drinking water should also be monitored in accordance with the guidelines used in the USA

Bio-dosimetry of ionizing radiation

International Nuclear Information System (INIS)

Hadjidekova, V.; Kristova, R.; Stainova, A.; Deleva, S.; Popova, L.; Georgieva, D.

2013-01-01

Full text: Introduction: The impact of ionizing radiation in medical, occupational and accidental human exposure leads to adverse side effects such as increased mortality and carcinogenesis. Information about the level of absorbed dose is important for risk assessment and for implementation of appropriate therapy. In most cases of actual or suspected exposure to ionizing radiation biological dosimetry is the only way to assess the absorbed dose. What you will learn: In this work we discuss the methods for biodosimetry and technological developments in their application in various emergency situations. The application of biological dosimetry and assessment of the influence of external factors in the conduct of epidemiological studies of radiation effects in protracted low-dose ionizing radiation on humans is presented. Discussion: The results of cytogenetic analysis and biological evaluation of absorbed dose based on the analysis of dicentrics in peripheral blood lymphocytes of five people injured in a severe radiation accident in Bulgaria in 2011 are presented. The assessed individual doses of the injured persons are in the range of 1.2 to 5,2 Gy acute homogeneous irradiation and are in line with the estimates of international experts. Conclusion: An algorithm to conduct a biological assessment of the dose in limited radiation accidents and in large scale radiation accidents with large number irradiated or suspected for exposure persons is proposed

Non-ionizing radiation

International Nuclear Information System (INIS)

Fischer, P.G.

1983-01-01

The still growing use of non-ionizing radiation such as ultraviolet radiation laser light, ultrasound and infrasound, has induced growing interest in the effects of these types of radiation on the human organism, and in probable hazards emanating from their application. As there are up to now no generally approved regulations or standards governing the use of non-ionizing radiation and the prevention of damage, it is up to the manufacturers of the relevant equipment to provide for safety in the use of their apparatus. This situation has led to a feeling of incertainty among manufacturers, as to how which kind of damage should be avoided. Practice has shown that there is a demand for guidelines stating limiting values, for measuring techniques clearly indicating safety thresholds, and for safety rules providing for safe handling. The task group 'Non-ionizing radiation' of the Radiation Protection Association started a programme to fulfill this task. Experts interested in this work have been invited to exchange their knowledge and experience in this field, and a collection of loose leaves will soon be published giving information and recommendations. (orig./HP) [de

Ionizing radiation sources. Ionizing radiation interaction with matter

International Nuclear Information System (INIS)

Popits, R.

1976-01-01

Fundamentals of nuclear physics are reviewed under the headings: obtaining of X-rays and their properties; modes of radioactive decay of natural or man-made radionuclides; radioactive neutron sources; nuclear fission as basis for devising nuclear reactors and weapons; thermonuclear reactions; cosmic radiation. Basic aspects of ionizing radiation interactions with matter are considered with regard to charged particles, photon radiation, and neutrons. (A.B.)

29 CFR 1910.1096 - Ionizing radiation.

Science.gov (United States)

2010-07-01

... 29 Labor 6 2010-07-01 2010-07-01 false Ionizing radiation. 1910.1096 Section 1910.1096 Labor... Ionizing radiation. (a) Definitions applicable to this section. (1) Radiation includes alpha rays, beta... the quantity of ionizing radiation absorbed, per unit of mass, by the body or by any portion of the...

Estimation of the contribution of ionization and excitation to the lethal effect of ionizing radiation

International Nuclear Information System (INIS)

Petin, V.G.; Komarov, V.P.

1982-01-01

A simple theoretical model is proposed for estimating the differential contribution of ionization and excitation to the lethal effect of ionizing radiation. Numerical results were obtained on the basis of published experimental data on the ability of bacterial cells Escherichia coli to undergo photoreactivation of radiation-induced damage. It was shown that inactivation by excitation may be highly significant for UV-hypersensitive cells capable of photoreactivation; inactivation by excitation increased with the energy of ionizing radiation and the volume of irradiated suspensions. The data are in qualitative agreement with the assumption of a possible contribution of the UV-component of Cerenkov radiation to the formation of excitations responsible for the lethal effect and the phenomenon of photoreactivation after ionizing radiation. Some predictions from the model are discussed. (orig.)

Ionizing radiation

Science.gov (United States)

Tobias, C. A.; Grigoryev, Y. G.

1975-01-01

The biological effects of ionizing radiation encountered in space are considered. Biological experiments conducted in space and some experiences of astronauts during space flight are described. The effects of various levels of radiation exposure and the determination of permissible dosages are discussed.

Advanced p-MOSFET Ionizing-Radiation Dosimeter

Science.gov (United States)

Buehler, Martin G.; Blaes, Brent R.

1994-01-01

Circuit measures total dose of ionizing radiation in terms of shift in threshold gate voltage of doped-channel metal oxide/semiconductor field-effect transistor (p-MOSFET). Drain current set at temperature-independent point to increase accuracy in determination of radiation dose.

Ionizing radiation and wild birds: a review

International Nuclear Information System (INIS)

Mellinger, P.J.; Schultz, V.

1975-01-01

Since the first atomic explosion, 16 July 1945 at the Trinity Site in south-central New Mexico, the impact of ionizing radiation on bird populations has been of concern to a few individuals. The proliferation of nuclear power plants has increased public concern as to possible deleterious effects of nuclear power plant operation on resident and migratory bird populations. Literature involving wild birds and ionizing radiation is not readily available, and only a few studies have been anywhere near comprehensive, with most effort directed towards monitoring radionuclide concentration in birds. The objective of the paper is to document the literature on wild birds and ionizing radiation including a brief description of pertinent papers

Management in the protection from ionizing radiation

International Nuclear Information System (INIS)

Radunovic, Miodrag; Nikolic, Krsto; Rakic, Goran

2008-01-01

There are numerous types and forms of endangering working and living environment, ranging from natural disasters to nuclear accidents. Challenges of the New Age determined that most of the countries reviewed its strategic decisions in the system of protection from ionizing radiation and nuclear safety and defined in a new way the threats, which could considerably imperil health of the population and national interests as well. Excessive radiation of the population became a serious and actual problem in the era of increasingly mass application of ionizing radiation, especially in medicine. The goal of this work is to reduce the risk through using knowledge and existing experiences, in particular when it comes to ionizing radiation in medicine. Optimization of the protection in radiology actually means an effort to find the compromise between quality information provided by diagnostics procedure and quality effects of therapy procedure on one side and dose of radiation received by patients on the other. Criteria for the quality management in the protection from ionizing radiation used in diagnostic radiology was given by the European Commission: European Guidelines on Quality Criteria for Diagnostic Radiographic Images, EUR, 16260. (author)

Ionizing radiation and a wood-based biorefinery

International Nuclear Information System (INIS)

Driscoll, Mark S.; Stipanovic, Arthur J.; Cheng, Kun; Barber, Vincent A.; Manning, Mellony; Smith, Jennifer L.; Sundar, Smith

2014-01-01

Woody biomass is widely available around the world. Cellulose is the major structural component of woody biomass and is the most abundant polymer synthesized by nature, with hemicellulose and lignin being second and third. Despite this great abundance, woody biomass has seen limited application outside of the paper and lumber industries. Its use as a feedstock for fuels and chemicals has been limited because of its highly crystalline structure, inaccessible morphology, and limited solubility (recalcitrance). Any economic use of woody biomass for the production of fuels and chemicals requires a “pretreatment” process to enhance the accessibility of the biomass to enzymes and/or chemical reagents. Electron beams (EB), X-rays, and gamma rays produce ions in a material which can then initiate chemical reactions and cleavage of chemical bonds. Such ionizing radiation predominantly scissions and degrades or depolymerizes both cellulose and hemicelluloses, less is known about its effects on lignin. This paper discusses how ionizing radiation can be used to make a wood-based biorefinery more environmentally friendly and profitable for its operators. - Highlights: • Ionizing radiation reduces the crystallinity of cellulose. • Ionizing radiation reduces cellulose's degree of polymerization. • The amount and rate of enzymatic hydrolysis of lignocellulosic materials, including wood, are increased with increasing radiation dose. • Wood and other lignocellulosic materials have the potential to be a renewable material for the production of chemicals and fuels

29 CFR 1926.53 - Ionizing radiation.

Science.gov (United States)

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Ionizing radiation. 1926.53 Section 1926.53 Labor... § 1926.53 Ionizing radiation. (a) In construction and related activities involving the use of sources of ionizing radiation, the pertinent provisions of the Nuclear Regulatory Commission's Standards for...

Ionizing radiation and life.

Science.gov (United States)

Dartnell, Lewis R

2011-01-01

Ionizing radiation is a ubiquitous feature of the Cosmos, from exogenous cosmic rays (CR) to the intrinsic mineral radioactivity of a habitable world, and its influences on the emergence and persistence of life are wide-ranging and profound. Much attention has already been focused on the deleterious effects of ionizing radiation on organisms and the complex molecules of life, but ionizing radiation also performs many crucial functions in the generation of habitable planetary environments and the origins of life. This review surveys the role of CR and mineral radioactivity in star formation, generation of biogenic elements, and the synthesis of organic molecules and driving of prebiotic chemistry. Another major theme is the multiple layers of shielding of planetary surfaces from the flux of cosmic radiation and the various effects on a biosphere of violent but rare astrophysical events such as supernovae and gamma-ray bursts. The influences of CR can also be duplicitous, such as limiting the survival of surface life on Mars while potentially supporting a subsurface biosphere in the ocean of Europa. This review highlights the common thread that ionizing radiation forms between the disparate component disciplines of astrobiology. © Mary Ann Liebert, Inc.

Conception of CTMSP ionizing radiation calibration laboratory

International Nuclear Information System (INIS)

Silva, Raimundo Dias da; Kibrit, Eduardo

2009-01-01

The present paper describes the implantation process of an ionizing radiation calibration laboratory in a preexistent installation in CTMSP (bunker) approved by CNEN to operate with gamma-ray for non destructive testing. This laboratory will extend and improve the current metrological capacity for the attendance to the increasing demand for services of calibration of ionizing radiation measuring instruments. Statutory and regulatory requirements for the licensing of the installation are presented and deeply reviewed. (author)

Ionizing radiation induces stemness in cancer cells.

Directory of Open Access Journals (Sweden)

Laura Ghisolfi

Full Text Available The cancer stem cell (CSC model posits the presence of a small number of CSCs in the heterogeneous cancer cell population that are ultimately responsible for tumor initiation, as well as cancer recurrence and metastasis. CSCs have been isolated from a variety of human cancers and are able to generate a hierarchical and heterogeneous cancer cell population. CSCs are also resistant to conventional chemo- and radio-therapies. Here we report that ionizing radiation can induce stem cell-like properties in heterogeneous cancer cells. Exposure of non-stem cancer cells to ionizing radiation enhanced spherogenesis, and this was accompanied by upregulation of the pluripotency genes Sox2 and Oct3/4. Knockdown of Sox2 or Oct3/4 inhibited radiation-induced spherogenesis and increased cellular sensitivity to radiation. These data demonstrate that ionizing radiation can activate stemness pathways in heterogeneous cancer cells, resulting in the enrichment of a CSC subpopulation with higher resistance to radiotherapy.

Radiation damage to tetramethylsilane and tetramethylgermanium ionization chambers

International Nuclear Information System (INIS)

Hoshi, Y.; Higuchi, M.; Oyama, K.

1994-01-01

Two detector media suitable for a warm liquid, ionization chamber filled with tetramethylsilane (TMS) and tetramethylgermanium (TMG) were exposed to γ radiation form a 60 Co source up to dose 579 Gray and 902 Gray, respectively. The electron lifetimes and the free ion yields were measured as a function of accumulated radiation dose. A similar behavior of the electron lifetimes and the free ion yields with increasing radiation does was observed between the TMS and TMG ionization chambers

Mutagenic action of non-ionizing radiations: its implication in radiation protection

International Nuclear Information System (INIS)

Madhvanath, U.; Subrahmanyam, P.; Sankaranarayanan, N.; Singh, D.R.

1977-01-01

Mutagenic effects of non-ionizing radiations except in the ultraviolet and near ultraviolet region are just not known. Results of the investigation carried out using a sensitive diploid yeast system, are presented. The arginine requiring mutant yeast strain BZ34 reverts to prototrophy following exposure to ionizing radiation. Reversion frequencies were determined following exposure to UV (254 nm), near ultraviolet (313, 353 nm) visible region (480 nm), neodymium laser (1.01 μm) and microwave (2450 MHz) radiations. An Aminco - Bowman Spectrophotofluorimeter was used to obtain wavelengths from UV to visible region. Yeast suspensions (concentration of 10 7 cells/ml) were irradiated to doses ranging from 10 7 to 10 9 erg/cm 3 as determined with potassium ferri-oxalate system. Exposure to laser pulses and microwave radiation ranged up to 45 J/cm 2 and 60 mW-h/cm 2 respectively. Results showed that the reversion induction efficiency decreased by six orders of magnitude from ionizing radiations to ultraviolet for the same absorbed dose and this efficiency has further decreased by a factor of fifteen when the wavelength is increased from 254 nm to 313 nm. Although killing could be effected with laser beams (45 J/cm 2 for 50% survival) no increase in the reversion was observed than the background level. It is concluded that radiation of wavelengths higher than 450 nm up to 12 cm studied is not mutagenic and with sufficient intensities of these radiations only killing of cells is possible due to thermal effects. This finding is compared with other known functional and morphological effects at cellular level due to low-level exposures of non-ionizing radiations

Worldwide exposures to ionizing radiation

International Nuclear Information System (INIS)

Bennett, B.G.

1993-01-01

All of mankind is exposed to ionizing radiation from natural sources, from human practices that release natural and artificial radionuclides to the environment, and from medical radiation procedures. This paper reviews the assessment in the UNSCEAR 1993 Report of the exposures of human populations worldwide to the various sources of ionizing radiation

Cataracts induced by microwave and ionizing radiation

International Nuclear Information System (INIS)

Lipman, R.M.; Tripathi, B.J.; Tripathi, R.C.

1988-01-01

Microwaves most commonly cause anterior and/or posterior subcapsular lenticular opacities in experimental animals and, as shown in epidemiologic studies and case reports, in human subjects. The formation of cataracts seems to be related directly to the power of the microwave and the duration of exposure. The mechanism of cataractogenesis includes deformation of heat-labile enzymes, such as glutathione peroxide, that ordinarily protect lens cell proteins and membrane lipids from oxidative damage. Oxidation of protein sulfhydryl groups and the formation of high-molecular-weight aggregates cause local variations in the orderly structure of the lens cells. An alternative mechanism is thermoelastic expansion through which pressure waves in the aqueous humor cause direct physical damage to the lens cells. Cataracts induced by ionizing radiation (e.g., X-rays and gamma rays) usually are observed in the posterior region of the lens, often in the form of a posterior subcapsular cataract. Increasing the dose of ionizing radiation causes increasing opacification of the lens, which appears after a decreasing latency period. Like cataract formation by microwaves, cataractogenesis induced by ionizing radiation is associated with damage to the lens cell membrane. Another possible mechanism is damage to lens cell DNA, with decreases in the production of protective enzymes and in sulfur-sulfur bond formation, and with altered protein concentrations. Until further definitive conclusions about the mechanisms of microwaves and ionizing radiation induced cataracts are reached, and alternative protective measures are found, one can only recommend mechanical shielding from these radiations to minimize the possibility of development of radiation-induced cataracts. 74 references

Effects of ionizing radiation on vitamins

International Nuclear Information System (INIS)

Thayer, D.W.; Fox, J.B. Jr.; Lakritz, L.

1991-01-01

Vitamins are known to be sensitive to the effects of ionizing radiation. Since most foods contain a large proportion of water, the most probable reaction of the ionizing radiation would be with water; and as vitamins are present in very small amounts compared with other substances in the food they will be affected indirectly by the radiation. This chapter discusses the effect of ionizing radiation on water soluble vitamins and fat soluble vitamins. (author)

Non-Ionizing Radiation Used in Microwave Ovens

Science.gov (United States)

... Non-Ionizing Radiation Used in Microwave Ovens Non-Ionizing Radiation Used in Microwave Ovens Explore the interactive, virtual ... can do Where to learn more About Non-Ionizing Radiation Used in Microwave Ovens Microwave Oven. Microwave ovens ...

Identifying and managing the risks of medical ionizing radiation in endourology.

Science.gov (United States)

Yecies, Todd; Averch, Timothy D; Semins, Michelle J

2018-02-01

The risks of exposure to medical ionizing radiation is of increasing concern both among medical professionals and the general public. Patients with nephrolithiasis are exposed to high levels of ionizing radiation through both diagnostic and therapeutic modalities. Endourologists who perform a high-volume of fluoroscopy guided procedures are also exposed to significant quantities of ionizing radiation. The combination of judicious use of radiation-based imaging modalities, application of new imaging techniques such as ultra-low dose computed tomography (CT) scan, and modifying use of current technology such as increasing ultrasound and pulsed fluoroscopy utilization offers the possibility of significantly reducing radiation exposure. We present a review of the literature regarding the risks of medical ionizing radiation to patients and surgeons as it pertains to the field of endourology and interventions that can be performed to limit this exposure. A review of the current state of the literature was performed using MEDLINE and PubMed. Interventions designed to limit patient and surgeon radiation exposure were identified and analyzed. Summaries of the data were compiled and synthesized in the body of the text. While no level 1 evidence exists demonstrating the risk of secondary malignancy with radiation exposure, the preponderance of evidence suggests a dose and age dependent increase in malignancy risk from ionizing radiation. Patients with nephrolithiasis were exposed to an average effective dose of 37mSv over a 2 year period. Multiple evidence-based interventions to limit patient and surgeon radiation exposure and associated risk were identified. Current evidence suggest an age and dose dependent risk of secondary malignancy from ionizing radiation. Urologists must act in accordance with ALARA principles to safely manage nephrolithiasis while minimizing radiation exposure.

Effects of ionizing radiation on life

International Nuclear Information System (INIS)

Rausch, L.

1982-01-01

Radiobiology in the last years was able to find detailed explanations for the effects of ionizing radiation on living organisms. But it is still impossible to make exact statements concerning the damages by radiation. Even now, science has to content itself with probability data. Moreover no typical damages of ionizing radiation can be identified. Therefore, the risks of ionizing radiation can only be determined by comparison with the spontaneous rate of cancerous or genetic defects. The article describes the interaction of high-energy radiation with the molecules of the organism and their consequences for radiation protection. (orig.)

Comparison between radiological protection against ionizing radiation and non ionizing radiation

International Nuclear Information System (INIS)

Jammet, H.P.

1992-01-01

Protection against IR and NIR developed in completely different ways because of the very different evolution of the techniques they involve. While as soon as 1928, the International Society of Radiology created the International Commission of Radiological Protection, we had to wait until 1977 to see the creation of the International Committee for NIR (INIRC) by IRPA. To compare protection against Ionizing Radiations and Non Ionizing Radiations we will first carry out a general analysis of its components and then we will draw the general conclusions leading to a quite comparable evolution. (author)

Comparison between radiological protection against ionizing radiation and non-ionizing radiation

International Nuclear Information System (INIS)

Jammet, H.P.

1988-01-01

The comparison of doctrines concerning protection against ionizing and non-ionizing radiation is a difficult task, because of the many areas in which it is applied. Radiological pollution has grown during the century, but its evolution has not been concomitant. This has resulted in a distortion that can be identified in the successive steps of the evaluation and protection against such radiation. For a better understanding, this discussion deals with the differences in interaction with matter and the induction of the related risks, on the varieties of protection systems and monitoring procedures

Ionizing Radiation Processing Technology

International Nuclear Information System (INIS)

Rida Tajau; Kamarudin Hashim; Jamaliah Sharif; Ratnam, C.T.; Keong, C.C.

2017-01-01

This book completely brief on the basic concept and theory of ionizing radiation in polymers material processing. Besides of that the basic concept of polymerization addition, cross-linking and radiation degradation also highlighted in this informative book. All of the information is from scientific writing based on comprehensive scientific research in polymerization industry which using the radiation ionizing. It is very useful to other researcher whose study in Nuclear Sciencea and Science of Chemical and Material to use this book as a guideline for them in future scientific esearch.

Biomedical applications of ionizing radiation

International Nuclear Information System (INIS)

Rosiak, J.M.; Pietrzak, M.

1997-01-01

Application of ionizing radiation for sterilization of medical devices, hygienization of cosmetics products as well as formation of biomaterials have been discussed. The advantages of radiation sterilization over the conventional methods have been indicated. The properties of modern biomaterials, hydrogels as well as some ways of their formation and modification under action of ionizing radiation were presented. Some commercial biomaterials of this kind produced in accordance with original Polish methods by means of radiation technique have been pointed out. (author)

Ionizing radiation and cancer prevention

International Nuclear Information System (INIS)

Hoel, D.G.

1995-01-01

Ionizing radiation long has been recognized as a cause of cancer. Among environmental cancer risks, radiation in unique in the variety of organs and tissues that it can affect. Numerous epidemiological studies with good dosimetry provide the basis for cancer risk estimation, including quantitative information derived from observed dose-response relationships. The amount of cancer attributable to ionizing radiation is difficult to estimate, but numbers such as 1 to 3% have been suggested. Some radiation-induced cancers attributable to ionizing radiation is difficult to estimate, but numbers such as 1 to 3% have been suggested. Some radiation-induced cancers attributable to naturally occurring exposures, such as cosmic and terrestrial radiation, are not preventable. The major natural radiation exposure, radon, can often be reduced, especially in the home, but not entirely eliminated. Medical use of radiation constitutes the other main category of exposure, radon, can often be reduced, especially in the home, but not entirely eliminated. Medical use of radiation constitutes the other main category of exposure; because of the importance of its benefits to one's health, the appropriate prevention strategy is to simply work to minimize exposures. 9 refs., 1 fig., 5 tabs

The study of the effects of ionizing and non-ionizing radiations on birth weight of newborns to exposed mothers.

Science.gov (United States)

Mortazavi, S M J; Shirazi, K R; Mortazavi, G

2013-01-01

Life evolved in an environment filled with a wide variety of ionizing and non-ionizing radiation. It was previously reported that medical exposures to pregnant women increases the risk of low birth weight. This study intends to investigate the relationship between exposure to ionizing and non-ionizing radiation and the risk of low birth weight. One thousand two hundred mothers with their first-term labor (vaginal or cesarean) whose newborns' history had been registered in neonates' screening program in Shiraz were interviewed and surveyed. Data collection was performed by the assessment of mother's history of radiography before and during pregnancy, physical examination of the mother for height and weight and weighing and examining the newborn for any diagnosis of disease and anomalies. There were no statistical significant differences between the mean weight of newborns whose mothers had been exposed to some common sources of ionizing and non-ionizing radiations such as dental or non dental radiographies, mobile phone, cordless phone and cathode ray tube (CRT) and those of non-exposed mothers. The findings of this study cast doubt on previous reports, which indicated that exposure to ionizing radiation during pregnancy increased the risk of low birth weight.

Down syndrome and ionizing radiation.

Science.gov (United States)

Verger, P

1997-12-01

This review examines the epidemiologic and experimental studies into the possible role ionizing radiation might play in Down Syndrome (trisomy 21). It is prompted by a report of a temporal cluster of cases of this chromosomal disorder observed in West Berlin exactly 9 mo after the radioactive cloud from Chernobyl passed. In approximately 90% of cases, Down Syndrome is due to the nondisjunction of chromosome 21, most often in the oocyte, which may be exposed to ionizing radiation during two separate periods: before the completion of the first meiosis or around the time of ovulation. Most epidemiologic studies into trisomies and exposure to ionizing radiation examine only the first period; the Chernobyl cluster is related to the second. Analysis of these epidemiologic results indicates that the possibility that ionizing radiation might be a risk factor in Down Syndrome cannot be excluded. The experimental results, although sometimes contradictory, demonstrate that irradiation may induce nondisjunction in oogenesis and spermatogenesis; they cannot, however, be easily extrapolated to humans. The weaknesses of epidemiologic studies into the risk factors for Down Syndrome at birth (especially the failure to take into account the trisomy cases leading to spontaneous abortion) are discussed. We envisage the utility and feasibility of new studies, in particular among women exposed to prolonged or repeated artificially-produced ionizing radiation.

Effects of Ionizing Radiation on Cellular Structures, Induced Instability, and Carcinogenesis

International Nuclear Information System (INIS)

Resat, Marianne S.; Arthurs, Benjamin J.; Estes, Brian J.; Morgan, william F.

2006-01-01

According to the American Cancer Society, the United States can expect 1,368,030 new cases of cancer in 2004 [1]. Among the many carcinogens Americans are exposed to, ionizing radiation will contribute to this statistic. Humans live in a radiation environment. Ionizing radiation is in the air we breathe, the earth we live on, and the food we eat. Man-made radiation adds to this naturally occurring radiation level thereby increasing the chance for human exposure. For many decades the scientific community, governmental regulatory bodies, and concerned citizens have struggled to estimate health risks associated with radiation exposures, particularly at low doses. While cancer induction is the primary concern and the most important somatic effect of exposure to ionizing radiation, potential health risks do not involve neoplastic diseases exclusively but also include somatic mutations that might contribute to birth defects and ocular maladies, and heritable mutations that might impact on disease risks in future generations. Consequently it is important we understand the effect of ionizing radiation on cellular structures and the subsequent long-term health risks associated with exposure to ionizing radiation

Prenatal exposition on ionizing radiations

International Nuclear Information System (INIS)

2001-01-01

The Sessions on Prenatal Exposition on Ionizing Radiations was organized by the Argentine Radioprotection Society, in Buenos Aires, between 8 and 9, November 2001. In this event, were presented papers on: biological effects of ionizing radiation; the radiation protection and the pregnant woman; embryo fetal development and its relationship with the responsiveness to teratogens; radioinduced delayed mental; neonatal irradiation: neurotoxicity and modulation of pharmacological response; pre implanted mouse embryos as a model of uranium toxicity studies; hereditary effects of the radiation and new advances from the UNSCEAR 2001; doses estimation in embryo

Ionizing radiation perception by insects

International Nuclear Information System (INIS)

Campanhola, C.

1980-04-01

The proof of the existence of a perception for ionizing radiation by insects was aimed at, as well as the determination of its processing mechanism. It was tried also to check if such perception induces the insects to keep away from the radiation source, proving therefore a protection against the harms caused by ionizing radiation, or else the stimulus for such behaviour is similar to that caused by light radiations. 60 Co and 241 Am were used as gamma radiation sources, the 60 Co source of 0.435mCi and the 241 Am of 99.68mCi activity. Adult insects were used with the following treatments : exposure to 60 Co and 241 Am radiation and non-exposure (control). A total of approximately 50 insects per replication was released in the central region of an opaque white wooden barrier divided into 3 sections with the same area - 60.0 cm diameter and 7.5 cm height - covered with a nylon screen. 5 replications per treatment were made and the distribution of the insects was evaluated by photographs taken at 15, 30, 45, and 60 minutes after release. Sitophilus oryzae (l., 1763) and Ephestia cautella (Walker, 1864) showed some response to 241 Am gamma radiation, i.e. negative tactism. It was concluded that ionizing radiations can be detected by insects through direct visual stimulus or by visual stimulus reslting from interaction of radiation-Cerenkov radiation - with some other occular component with a refraction index greater than water. Also, the activity of the radioactive source with regard to perception for ionizing radiation, is of relevance in comparison with the energy of the radiation emitted by same, or in other words, what really matters is the radiation dose absorbed. (Author) [pt

Regulation on protection against ionizing radiations

International Nuclear Information System (INIS)

1995-01-01

This regulation has as the objective to establish the criteria tending toward protecting the health of the population of the radiologic risks that can be derive from the employment of the ionizing radiations and similar activities. It establishes the requirements to comply with the radiactive installations, equipment transmitters of ionizing radiations, personal that works in them, operate the equipment and carry out any another similar activity such as: production, importation, exportation, transportation, transference of radioactive material or equipment generators of radiations ionizing. (S. Grainger) [es

Ionizing radiation interactions with DNA: nanodosimetry

International Nuclear Information System (INIS)

Bug, Marion; Nettelbeck, Heidi; Hilgers, Gerhard; Rabus, Hans

2011-01-01

The metrology of ionizing radiation is based on measuring values that are averaged over macroscopic volume elements, for instance the energy dose is defined as ratio of the energy deposited on the absorber and the absorber mass. For biological or medical radiation effects the stochastic nature of radiation interaction id of main importance, esp. the interaction of ionizing radiation with the DNA as the genetic information carrier. For radiotherapy and risk evaluation purposes a comprehensive system of radiation weighing factors and other characteristics, like radiation quality or relative biological efficacy was developed. The nanodosimetry is aimed to develop a metrological basis relying on physical characteristics of the microscopic structure of ionizing radiation tracks. The article includes the development of experimental nanodosimetric methods, the respective calibration techniques, Monte-Carlo simulation of the particle track microstructure and the correlation nanodosimetry and biological efficiency.

Ionizing radiation, nuclear energy and radiation protection for school

International Nuclear Information System (INIS)

Lucena, E.A.; Reis, R.G.; Pinho, A.S.; Alves, A.S.; Rio, M.A.P.; Reis, A.A.; Silva, J.W.S.; Paula, G.A. de; Goncalves Junior, M.A.

2017-01-01

Since the discovery of X-rays in 1895, ionizing radiation has been applied in many sectors of society, such as medicine, industry, safety, construction, engineering and research. However, population is unaware of both the applications of ionizing radiation and their risks and benefits. It can be seen that most people associate the terms 'radiation' and 'nuclear energy' with the atomic bomb or cancer, most likely because of warlike applications and the stealthy way radioactivity had been treated in the past. Thus, it is necessary to clarify the population about the main aspects related to the applications, risks and associated benefits. These knowledge can be disseminated in schools. Brazilian legislation for basic education provides for topics such as nuclear energy and radioactivity to high school students. However, some factors hamper such an educational practice, namely, few hours of class, textbooks do not address the subject, previous concepts obtained in the media, difficulty in dealing with the subject in the classroom, phobia, etc. One solution would be the approximation between schools and institutions that employ technologies involving radioactivity, which would allow students to know the practices, associated radiological protection, as well as the risks and benefits to society. Currently, with the increasing application of ionizing radiation, especially in medicine, it is necessary to demystify the use of radioactivity. (author)

The study of the effects of ionizing and non-ionizing radiations on birth weight of newborns to exposed mothers

OpenAIRE

Mortazavi, S. M. J.; Shirazi, K. R.; Mortazavi, G.

2013-01-01

Objectives: Life evolved in an environment filled with a wide variety of ionizing and non-ionizing radiation. It was previously reported that medical exposures to pregnant women increases the risk of low birth weight. This study intends to investigate the relationship between exposure to ionizing and non-ionizing radiation and the risk of low birth weight. Materials and Methods: One thousand two hundred mothers with their first-term labor (vaginal or cesarean) whose newborns? history had been...

100 years of ionizing radiation protection

International Nuclear Information System (INIS)

Baltrukiewicz, Z.; Musialowicz, T.

1999-01-01

The development of radiation protection from the end of 19. century and evolution of opinion about injurious effect of ionizing radiation were presented. Observations of undesirable effects of ionizing radiation exposition, progress of radiobiology and dosimetry directed efforts toward radiation protection. These activities covered, at the beginning, limited number of persons and were subsequently extended to whole population. The current means, goals and regulations of radiological control have been discussed

Radiation protection and dosimetry issues in the medical applications of ionizing radiation

International Nuclear Information System (INIS)

Vaz, Pedro

2014-01-01

The technological advances that occurred during the last few decades paved the way to the dissemination of CT-based procedures in radiology, to an increasing number of procedures in interventional radiology and cardiology as well as to new techniques and hybrid modalities in nuclear medicine and in radiotherapy. These technological advances encompass the exposure of patients and medical staff to unprecedentedly high dose values that are a cause for concern due to the potential detrimental effects of ionizing radiation to the human health. As a consequence, new issues and challenges in radiological protection and dosimetry in the medical applications of ionizing radiation have emerged. The scientific knowledge of the radiosensitivity of individuals as a function of age, gender and other factors has also contributed to raising the awareness of scientists, medical staff, regulators, decision makers and other stakeholders (including the patients and the public) for the need to correctly and accurately assess the radiation induced long-term health effects after medical exposure. Pediatric exposures and their late effects became a cause of great concern. The scientific communities of experts involved in the study of the biological effects of ionizing radiation have made a strong case about the need to undertake low dose radiation research and the International System of Radiological Protection is being challenged to address and incorporate issues such as the individual sensitivities, the shape of dose–response relationship and tissue sensitivity for cancer and non-cancer effects. Some of the answers to the radiation protection and dosimetry issues and challenges in the medical applications of ionizing radiation lie in computational studies using Monte Carlo or hybrid methods to model and simulate particle transport in the organs and tissues of the human body. The development of sophisticated Monte Carlo computer programs and voxel phantoms paves the way to an accurate

New Croatian Act on Ionizing Radiation Protection

International Nuclear Information System (INIS)

Grgic, S.

1998-01-01

According to the new Croatian Act on ionizing radiation protection which is in a final stage of genesis, Ministry of Health of the Republic of Croatia is the governmental body responsible for all aspects relating sources of ionizing radiation in Croatia: practices, licenses, users, transport, in medicine and industry as well, workers with sources of ionizing radiation, emergency preparedness in radiological accidents, storage of radioactive wastes, x-ray machines and other machines producing ionizing radiation and radioactive materials in the environment. Ministry of Health is responsible to the Government of the Republic of Croatia, closely collaborating with the Croatian Radiation Protection Institute, health institution for the performance of scientific and investigation activities in the field of radiation protection. Ministry of Health is also working together with the Croatian Institute for the Occupational Health. More emphasis has been laid on recent discussion among the world leading radiation protection experts on justification of the last recommendations of the ICRP 60 publication. (author)

Radiation dependent ionization model

International Nuclear Information System (INIS)

Busquet, M.

1991-01-01

For laser created plasma simulation, hydrodynamics codes need a non-LTE atomic physics package for both EOS and optical properties (emissivity and opacity). However in XRL targets as in some ICF targets, high Z material can be found. In these cases radiation trapping can induce a significant departure from the optically thin ionization description. The authors present a method to change an existing LTE code into a non-LTE code with coupling of ionization to radiation. This method has very low CPU cost and can be used in 2D simulations

Environmental Ionizing Radiation Survey of Quarry Sites in Ilorin ...

African Journals Online (AJOL)

NJABS

Besides, human exposure to radiations may increase if they live in areas with radiation doses above normal background value. Hence, this study involves the determination of background ionizing radiation levels around quarry sites in the industrial area of Ilorin with a view to assessing whether the radiation level is within ...

Ionizing radiation sources management in the Commonwealth of Independent States - CIS

International Nuclear Information System (INIS)

Iskra, A.; Bufetova, M.

2006-01-01

Ionizing radiation sources cover a broad band of power: from powerful NPP reactors and research reactors to portable radioisotope ionizing radiation sources applied in medicine, agriculture, industry and in the energy supply systems of remote facilities. At present, scales and use field of radionuclide sources in the CIS have the tendency to increase. In this connection, the issues of ionizing radiation sources management safety at all stages of their life cycle, from production to treatment, have been of a great importance. The materials on ionizing radiation sources inventory and treatment in the CIS (Russia, Armenia, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Tajikistan and Ukraine) are presented in the report. It is shown that in some republics, there is difficulty in ionizing radiation sources accounting and control system; the national regulatory and legal framework bases regulating activity on radioactive sources use, localization and treatment require update. Many problems are connected with the sources beyond state accounting. The problem of ionizing radiation sources use safety is complicated by the growing activity of various terrorist groups. The opportunity to use ionizing radiation sources with terrorism goals requires the application of defined systems of security and physical protection at all stages of their management. For this purpose a collective, with all CIS countries, organization of radioactive sources accounting and control as well as countermeasures on their illegal transportation and use are necessary. In this connection, the information collection regarding situation with providing of ionizing radiation sources safety, conditions of equipment and storage facilities, radioactive materials accounting and control system in the CIS countries is vitally needed

Measurement of indoor background ionizing radiation in some ...

African Journals Online (AJOL)

Certain types of building materials are known to be radioactive. Exposure to indoor ionizing radiation like exposure to any other type of ionizing radiation results in critical health challenges. Measurement of the background ionizing radiation profile within the Chemistry Research Laboratory and Physics Laboratory III all of ...

Basic symbol for ionizing radiations (second revision)

International Nuclear Information System (INIS)

1992-01-01

Includes a detailed description of basic symbol for ionizing radiations to be used to prevent about the presence, or possibility of presence, of ionizing radiations (X-ray, gamma radiation, particles, electrons, neutrons and protons), as well as to identify radioactive devices and materials

Medical students' knowledge of ionizing radiation and radiation protection.

Science.gov (United States)

Hagi, Sarah K; Khafaji, Mawya A

2011-05-01

To assess the knowledge of fourth-year medical students in ionizing radiation, and to study the effect of a 3-hour lecture in correcting their misconceptions. A cohort study was conducted on fourth-year medical students at King Abdul-Aziz University, Jeddah, Kingdom of Saudi Arabia during the academic year 2009-2010. A 7-question multiple choice test-type questionnaire administered before, and after a 3-hour didactic lecture was used to assess their knowledge. The data was collected from December 2009 to February 2010. The lecture was given to 333 (72%) participants, out of the total of 459 fourth-year medical students. It covered topics in ionizing radiation and radiation protection. The questionnaire was validated and analyzed by 6 content experts. Of the 333 who attended the lecture, only 253 (76%) students completed the pre- and post questionnaire, and were included in this study. The average student score improved from 47-78% representing a gain of 31% in knowledge (p=0.01). The results indicated that the fourth-year medical students' knowledge regarding ionizing radiation and radiation protection is inadequate. Additional lectures in radiation protection significantly improved their knowledge of the topic, and correct their current misunderstanding. This study has shown that even with one dedicated lecture, students can learn, and absorb general principles regarding ionizing radiation.

Safe use of ionizing radiations

Energy Technology Data Exchange (ETDEWEB)

1973-01-01

Based on the ''Code of Practice for the protection of persons against ionizing radiations arising from medical and dental use'' (CIS 74-423), this handbook shows how hospital staff can avoid exposing themselves and others to these hazards. It is designed particularly for junior and student nurses. Contents: ionizing radiations, their types and characteristics; their uses and dangers; basic principles in their safe use; safe use in practice; explanation of terms.

Risks from ionizing radiation during pregnancy

Directory of Open Access Journals (Sweden)

mehrdad Gholami

2007-04-01

Full Text Available Gholami M1, Abedini MR2, Khossravi HR3, Akbari S4 1. Instructor, Department of medical physics, Faculty of medicine, Lorestan University of medical sciences 2. Assistant professor, Department of radiology, Faculty of medicine, Lorestan University of medical sciences 3. Assistant professor, Department of radiation protection, Iranian Atomic Energy Organization 4. Assistant professor, Department of gynecology, Faculty of medicine, Lorestan University of medical sciences Abstract Background: The discovery of the X-ray in November 1895 by the W. C. Roentgen caused the increasing use of x-ray, because of the benefits that patients get from the resultant the diagnosis. Since medical radiation exposure are mainly in artificial radiation sources, immediately after the x- ray discovery, progressive dermatitis and ophthalmic diseases were occurred in the early physicians and physicists. But delay effects were observed approximately 20 years after the x-ray discovery. History: Based on the studies, ionizing radiation is a potential hazard to the developing fetus, avoiding unnecessary radiation exposure to pregnant women is a standard practice in radiology, unless there are important clinical indications. Due to difference in stages of fetus development, using of the current radiation protection standards includes: justification of a practice, optimization of radiation protection procedures and dose limitation to prevent of serious radiation induced conditions is necessary. Conclusion: Conversely the somatic and genetic effects of x-rays, since the X-ray has the benefit effects, special in diagnostic and treatment procedures, there is increasing use of x-ray, so using of the latest radiation protection procedures is necessary. Radiation protection not only is a scientific subject but also is a philosophy, Moral and reasonable. since the ionizing radiation is a potential hazard to the developing fetus, avoiding unnecessary radiation exposure to the pregnant

Code of practice for ionizing radiation

International Nuclear Information System (INIS)

Khoo Boo Huat

1995-01-01

Prior to 1984, the use of ionizing radiation in Malaysia was governed by the Radioactive Substances Act of 1968. After 1984, its use came under the control of Act 304, called the Atomic Energy Licensing Act 1984. Under powers vested by the Act, the Radiation Protection (Basic Safety Standards) Regulations 1988 were formulated to regulate its use. These Acts do not provide information on proper working procedures. With the publication of the codes of Practice by The Standards and Industrial Research Institute of Malaysia (SIRIM), the users are now able to follow proper guidelines and use ionizing radiation safely and beneficially. This paper discusses the relevant sections in the following codes: 1. Code of Practice for Radiation Protection (Medical X-ray Diagnosis) MS 838:1983. 2. Code of Practice for Safety in Laboratories Part 4: Ionizing radiation MS 1042: Part 4: 1992. (author)

Non-Ionizing Radiation - sources, exposure and health effects

International Nuclear Information System (INIS)

Hietanen, M.

2003-01-01

Non-ionizing radiation contains the electromagnetic wavelengths from ultraviolet (UV) radiation to static electric and magnetic fields. Optical radiation consists of UV, visible and infrared (IR) radiation while EM fields include static, extremely low (ELF), low frequency (LF) and radiofrequency (RF) fields. The principal scientific organization on non-ionizing radiation is the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The main activity of ICNIRP is to provide guidance on safe exposure and protection of workers and members of the public by issuing statements and recommendations. (orig.)

Epidemiology and ionizing radiations

International Nuclear Information System (INIS)

Bourguignon, M.; Masse, R.; Slama, R.; Spira, A.; Timarche, M.; Laurier, D.; Billon, S.; Rogel, A.; Telle Lamberton, M.; Catelinois, O.; Thierry, I.; Grosche, B.; Ron, E.; Vathaire, F. de; Cherie Challine, L.; Donadieu, J.; Pirard, Ph.; Bloch, J.; Setbon, M.

2004-01-01

The ionizing radiations have effects on living being. The determinist effects appear since a threshold of absorbed dose of radiation is reached. In return, the stochastic effects of ionizing radiations are these ones whom apparition cannot be described except in terms of probabilities. They are in one hand, cancers and leukemia, on the other hand, lesions of the genome potentially transmissible to the descendants. That is why epidemiology, defined by specialists as the science that studies the frequency and distribution of illness in time and space, the contribution of factors that determine this frequency and this distribution among human populations. This issue gathers and synthesizes the knowledge and examines the difficulties of methodologies. It allows to give its true place to epidemiology. (N.C.)

Ionizing radiation, radiation sources, radiation exposure, radiation effects. Pt. 2

International Nuclear Information System (INIS)

Schultz, E.

1985-01-01

Part 2 deals with radiation exposure due to artificial radiation sources. The article describes X-ray diagnosis complete with an analysis of major methods, nuclear-medical diagnosis, percutaneous radiation therapy, isotope therapy, radiation from industrial generation of nucler energy and other sources of ionizing radiation. In conclusion, the authors attempt to asses total dose, genetically significant dose and various hazards of total radiation exposure by means of a summation of all radiation impacts. (orig./WU) [de

Is ionizing radiation regulated more stringently than chemical carcinogens

International Nuclear Information System (INIS)

Travis, C.C.; Pack, S.R.; Hattemer-Frey, H.A.

1989-01-01

It is widely believed that United States government agencies regulate exposure to ionizing radiation more stringently than exposure to chemical carcinogens. It is difficult to verify this perception, however, because chemical carcinogens and ionizing radiation are regulated using vastly different strategies. Chemical carcinogens are generally regulated individually. Regulators consider the risk of exposure to one chemical rather than the cumulative radiation exposure from all sources. Moreover, standards for chemical carcinogens are generally set in terms of quantities released or resultant environmental concentrations, while standards for ionizing radiation are set in terms of dose to the human body. Since chemicals and ionizing radiation cannot be compared on the basis of equal dose to the exposed individual, standards regulating chemicals and ionizing radiation cannot be compared directly. It is feasible, however, to compare the two sets of standards on the basis of equal risk to the exposed individual, assuming that standards for chemicals and ionizing radiation are equivalent if estimated risk levels are equitable. This paper compares risk levels associated with current standards for ionizing radiation and chemical carcinogens. The authors do not attempt to determine whether either type of risk is regulated too stringently or not stringently enough but endeavor only to ascertain if ionizing radiation is actually regulated more strictly than chemical carcinogens

Reducing ionizing radiation doses during cardiac interventions in pregnant women.

Science.gov (United States)

Orchard, Elizabeth; Dix, Sarah; Wilson, Neil; Mackillop, Lucy; Ormerod, Oliver

2012-09-01

There is concern over ionizing radiation exposure in women who are pregnant or of child-bearing age. Due to the increasing prevalence of congenital and acquired heart disease, the number of women who require cardiac interventions during pregnancy has increased. We have developed protocols for cardiac interventions in pregnant women and women of child-bearing age, aimed at substantially reducing both fluoroscopy duration and radiation doses. Over five years, we performed cardiac interventions on 15 pregnant women, nine postpartum women and four as part of prepregnancy assessment. Fluoroscopy times were minimized by simultaneous use of intracardiac echocardiography, and by using very low frame rates (2/second) during fluoroscopy. The procedures most commonly undertaken were closure of atrial septal defect (ASD) or patent foramen ovale (PFO) in 16 women, coronary angiograms in seven, right and left heart catheters in three and two stent placements. The mean screening time for all patients was 2.38 minutes (range 0.48-13.7), the median radiation dose was 66 (8.9-1501) Gy/cm(2). The median radiation dose to uterus was 1.92 (0.59-5.47) μGy, and the patient estimated dose was 0.24 (0.095-0.80) mSv. Ionizing radiation can be used safely in the management of severe cardiac structural disease in pregnancy, with very low ionizing radiation dose to the mother and extremely low exposure to the fetus. With experience, ionizing radiation doses at our institution have been reduced.

Circuitry for use with an ionizing-radiation detector

International Nuclear Information System (INIS)

Marshall, J.H. III; Harrington, T.M.

1976-01-01

An improved system of circuitry for use in combination with an ionizing-radiation detector over a wide range of radiation levels includes a current-to-frequency converter together with a digital data processor for respectively producing and measuring a pulse repetition frequency which is proportional to the output current of the ionizing-radiation detector, a dc-to-dc converter for providing closely regulated operating voltages from a rechargeable battery and a bias supply for providing high voltage to the ionization chamber. The ionizing-radiation detector operating as a part of this system produces a signal responsive to the level of ionizing radiation in the vicinity of the detector, and this signal is converted into a pulse frequency which will vary in direct proportion to such level of ionizing-radiation. The data processor, by counting the number of pulses from the converter over a selected integration interval, provides a digital indication of radiation dose rate, and by accumulating the total of all such pulses provides a digital indication of total integrated dose. Ordinary frequency-to-voltage conversion devices or digital display techniques can be used as a means for providing audible and visible indications of dose and dose-rate levels

Radiation exposure of airline crew members to the atmospheric ionizing radiation environment

International Nuclear Information System (INIS)

Angelis, G. De; Ballard, T.; Lagorio, S.; Verdecchia, A.

2000-01-01

All risk assessment techniques for possible health effects from low dose rate radiation exposure should combine knowledge both of the radiation environment and of the biological response, whose effects (e.g. carcinogenesis) are usually evaluated through mathematical models and/or animal and cell experiments. Data on human exposure to low dose rate radiation exposure and its effects are not readily available, especially with regards to stochastic effects, related to carcinogenesis and therefore to cancer risks, for which the event probability increases with increasing radiation exposure. The largest source of such data might be airline flight personnel, if enrolled for studies on health effects induced by the cosmic-ray generated atmospheric ionizing radiation, whose total dose, increasing over the years, might cause delayed radiation-induced health effects, with the high-LET and highly ionizing neutron component typical of atmospheric radiation. In 1990 flight personnel has been given the status of 'occupationally exposed to radiation' by the International Commission for Radiation Protection (ICRP), with a received radiation dose that is at least twice larger than that of the general population. The studies performed until now were limited in scope and cohort size, and moreover no information whatsoever on radiation occupational exposure (e.g. dose, flight hours, route haul, etc.) was used in the analysis, so no correlation has been until now possible between atmospheric ionizing radiation and (possibly radiation-induced) observed health effects. Our study addresses the issues, by considering all Italian civilian airline flight personnel, both cockpit and cabin crew members, with about 10,000 people selected, whose records on work history and actual flights (route, aircraft type, date, etc. for each individual flight for each person where possible) are considered. Data on actual flight routes and profiles have been obtained for the whole time frame. The actual dose

Hygiene of ionizing radiations

International Nuclear Information System (INIS)

Legare, I.-M.; Conceicao Cunha, M. da

1976-01-01

The concepts of quality factor and rem are introduced and a table of biological effects of external ionizing radiation sources is presented. Natural exposures, with tables of background radiation sources and of doses due to cosmic rays on high altitude areas and their populations are treated, as well as medical exposures; artificial background; fallout; scientific, industrial and other sources. The maximum and limit doses for man are given and tables of maximum admissible doses of ionizing radiations for 16-18 year old workers professionaly exposed, for professionals eventually subjected to radiation in their work and for people eventually exposed. Professional protection is discussed and tables are given of half-value layer of water, concrete, iron and lead for radiations of different energies, as well as the classification of exposure zones to the radiations and of maximum acceptable contamination for surfaces. The basic safety standards for radiation protection are summarized; tables are given also with emergency references for internal irradiation. Procedures with patients which received radioisotopes are discussed. At last, consideration is given to the problem of radioactive wastes in connection with the medical use of radionuclides [pt

Targeted and non-targeted effects of ionizing radiation

Directory of Open Access Journals (Sweden)

Omar Desouky

2015-04-01

Full Text Available For a long time it was generally accepted that effects of ionizing radiation such as cell death, chromosomal aberrations, DNA damage, mutagenesis, and carcinogenesis result from direct ionization of cell structures, particularly DNA, or from indirect damage through reactive oxygen species produced by radiolysis of water, and these biological effects were attributed to irreparable or misrepaired DNA damage in cells directly hit by radiation. Using linear non-threshold model (LNT, possible risks from exposure to low dose ionizing radiation (below 100 mSv are estimated by extrapolating from data obtained after exposure to higher doses of radiation. This model has been challenged by numerous observations, in which cells that were not directly traversed by the ionizing radiation exhibited responses similar to those of the directly irradiated cells. Therefore, it is nowadays accepted that the detrimental effects of ionizing radiation are not restricted only in the irradiated cells, but also to non-irradiated bystander or even distant cells manifesting various biological effects.

Biological effects of ionizing radiation - changing worker attitudes

International Nuclear Information System (INIS)

Johnson, N.; Schenley, C.

1989-01-01

Training Resources and Data Exchange (TRADE) Radiation Protection Training Special Interest Group has taken an innovative approach to providing DOE contractors with radiation worker training material information. Newly-hired radiation workers may be afraid to work near radiation and long-term radiation workers may become indifferent to the biological hazard of radiation. Commercially available training material is often presented at an inappropriate technical level or in an uninteresting style. These training problems have been addressed in the DOE system through development of a training videotape and supporting material package entitled Understanding Ionizing Radiation and its Biological Effects. The training package, developed and distributed by TRADE specifically to meet the needs of DOE contractor facilities, contains the videotape and accompanying paper supporting materials designed to assist the instructor. Learning objectives, presentation suggestion for the instructor, trainee worksheets, guided discussion questions, and trainee self-evaluation sheets are included in the training package. DOE contractors have agreed that incorporating this training module into radiation worker training programs enhances the quality of the training and increase worker understanding of the biological effects of ionizing radiation

Effects of ionizing radiation and steady magnetic field on erythrocytes

International Nuclear Information System (INIS)

Ivanov, S. P.; Galutzov, B. P.; Kuzmanova, M. A.; Markov, M. S.

1996-01-01

A complex biophysical test for studying the effects of ionizing and non-ionizing radiation has been developed. The following cell and membrane parameters have been investigated: cell size, cell shape, cell distribution by size, electrophoretic mobility, extent of hemolysis, membrane transport and membrane impedance. Gamma ray doses of 2.2 Gy and 3.3 Gy were used as ionizing radiation and steady (DC) magnetic field of 5-90 mT representing the non-ionizing radiation. Erythrocytes from humans and rats were exposed in vitro to both ionizing and non-ionizing radiation. In some experiments ionizing radiation was applied in vivo as well. Each of the simultaneously studied parameters have been found to change as a function of applied radiation. The proposed test allows an estimation of the changes in the elastic, rheological and electrical parameters of cells and biological membranes. Results indicate that ionizing radiation is significantly more effective in an in vivo application, while magnetic fields are more effective when applied in vitro. Surprisingly, steady magnetic fields were found to act as protector against some harmful effects of ionizing radiation. (authors)

Ionizing radiation effects on floating gates

International Nuclear Information System (INIS)

Cellere, G.; Paccagnella, A.; Visconti, A.; Bonanomi, M.

2004-01-01

Floating gate (FG) memories, and in particular Flash, are the dominant among modern nonvolatile memory technologies. Their performance under ionizing radiation was traditionally studied for the use in space, but has become of general interest in recent years. We are showing results on the charge loss from programmed FG arrays after 10 keV x-rays exposure. Exposure to ionizing radiation results in progressive discharge of the FG. More advanced devices, featuring smaller FG, are less sensitive to ionizing radiation that older ones. The reason is identified in the photoemission of electrons from FG, since at high doses it dominates over charge loss deriving from electron/hole pairs generation in the oxides

Role of Ionizing Radiation in Neurodegenerative Diseases

Directory of Open Access Journals (Sweden)

Neel K. Sharma

2018-05-01

Full Text Available Ionizing radiation (IR from terrestrial sources is continually an unprotected peril to human beings. However, the medical radiation and global radiation background are main contributors to human exposure and causes of radiation sickness. At high-dose exposures acute radiation sickness occurs, whereas chronic effects may persist for a number of years. Radiation can increase many circulatory, age related and neurodegenerative diseases. Neurodegenerative diseases occur a long time after exposure to radiation, as demonstrated in atomic bomb survivors, and are still controversial. This review discuss the role of IR in neurodegenerative diseases and proposes an association between neurodegenerative diseases and exposure to IR.

Role of Ionizing Radiation in Neurodegenerative Diseases

Science.gov (United States)

Sharma, Neel K.; Sharma, Rupali; Mathur, Deepali; Sharad, Shashwat; Minhas, Gillipsie; Bhatia, Kulsajan; Anand, Akshay; Ghosh, Sanchita P.

2018-01-01

Ionizing radiation (IR) from terrestrial sources is continually an unprotected peril to human beings. However, the medical radiation and global radiation background are main contributors to human exposure and causes of radiation sickness. At high-dose exposures acute radiation sickness occurs, whereas chronic effects may persist for a number of years. Radiation can increase many circulatory, age related and neurodegenerative diseases. Neurodegenerative diseases occur a long time after exposure to radiation, as demonstrated in atomic bomb survivors, and are still controversial. This review discuss the role of IR in neurodegenerative diseases and proposes an association between neurodegenerative diseases and exposure to IR. PMID:29867445

Ionizing radiations, detection, dosimetry, spectrometry

International Nuclear Information System (INIS)

Blanc, D.

1997-10-01

A few works in French language are devoted to the detection of radiations. The purpose of this book is to fill a gap.The five first chapters are devoted to the properties of ionizing radiations (x rays, gamma rays, leptons, hadrons, nuclei) and to their interactions with matter. The way of classification of detectors is delicate and is studied in the chapter six. In the chapter seven are studied the statistics laws for counting and the spectrometry of particles is treated. The chapters eight to thirteen study the problems of ionization: charges transport in a gas, ionization chambers (theory of Boag), counters and proportional chambers, counters with 'streamers', chambers with derive, spark detectors, ionization chambers in liquid medium, Geiger-Mueller counters. The use of a luminous signal is the object of the chapters 14 to 16: conversion of a luminous signal in an electric signal, scintillators, use of the Cerenkov radiation. Then, we find the neutron detection with the chapter seventeen and the dosimetry of particles in the chapter eighteen. This book does not pretend to answer to specialists questions but can be useful to physicians, engineers or physics teachers. (N.C.)

Thin films deposited by laser ablation for the measurement of the ionizing and non-ionizing radiation

International Nuclear Information System (INIS)

Villarreal B, J.E.; Escobar A, L.; Camps, E.; Romero, S.; Gonzalez, P.; Salinas, B.

2001-01-01

In this work the obtained results to synthesize thin films of amorphous carbon with incorporated nitrogen and hydrogen are presented, as well as thin films of aluminium oxide using the laser ablation technique. The thin films were exposed to ionizing radiation (gamma rays of a 60 Co source, beta radiation of a 90 Sr source) and a non-ionizing radiation (UV radiation). The obtained results show that it is possible to obtain materials in thin film form with thickness of hundreds of nanometers, which present thermoluminescent response when being irradiated with ionizing radiation and non-ionizing radiation. (Author)

Chemical protection against ionizing radiation. Final report

International Nuclear Information System (INIS)

Livesey, J.C.; Reed, D.J.; Adamson, L.F.

1984-08-01

The scientific literature on radiation-protective drugs is reviewed. Emphasis is placed on the mechanisms involved in determining the sensitivity of biological material to ionizing radiation and mechanisms of chemical radioprotection. In Section I, the types of radiation are described and the effects of ionizing radiation on biological systems are reviewed. The effects of ionizing radiation are briefly contrasted with the effects of non-ionizing radiation. Section II reviews the contributions of various natural factors which influence the inherent radiosensitivity of biological systems. Inlcuded in the list of these factors are water, oxygen, thiols, vitamins and antioxidants. Brief attention is given to the model describing competition between oxygen and natural radioprotective substances (principally, thiols) in determining the net cellular radiosensitivity. Several theories of the mechanism(s) of action of radioprotective drugs are described in Section III. These mechanisms include the production of hypoxia, detoxication of radiochemical reactive species, stabilization of the radiobiological target and the enhancement of damage repair processes. Section IV describes the current strategies for the treatment of radiation injury. Likely areas in which fruitful research might be performed are described in Section V. 495 references

Chemical protection against ionizing radiation. Final report

Energy Technology Data Exchange (ETDEWEB)

Livesey, J.C.; Reed, D.J.; Adamson, L.F.

1984-08-01

The scientific literature on radiation-protective drugs is reviewed. Emphasis is placed on the mechanisms involved in determining the sensitivity of biological material to ionizing radiation and mechanisms of chemical radioprotection. In Section I, the types of radiation are described and the effects of ionizing radiation on biological systems are reviewed. The effects of ionizing radiation are briefly contrasted with the effects of non-ionizing radiation. Section II reviews the contributions of various natural factors which influence the inherent radiosensitivity of biological systems. Inlcuded in the list of these factors are water, oxygen, thiols, vitamins and antioxidants. Brief attention is given to the model describing competition between oxygen and natural radioprotective substances (principally, thiols) in determining the net cellular radiosensitivity. Several theories of the mechanism(s) of action of radioprotective drugs are described in Section III. These mechanisms include the production of hypoxia, detoxication of radiochemical reactive species, stabilization of the radiobiological target and the enhancement of damage repair processes. Section IV describes the current strategies for the treatment of radiation injury. Likely areas in which fruitful research might be performed are described in Section V. 495 references.

Food irradiation with ionizing radiation

International Nuclear Information System (INIS)

Hrudkova, A.; Pohlova, M.; Sedlackova, J.

1974-01-01

Application possibilities are discussed of ionizing radiation in inhibiting plant germination, in radiopasteurization and radiosterilization of food. Also methods of combining radiation with thermal food sterilization are discussed. The problems of radiation doses and of hygienic purity of irradiated foodstuffs are dealt with. (B.S.)

Pressing problems of measurement of ionizing radiations

International Nuclear Information System (INIS)

Fominykh, V.I.; Yudin, M.F.

1993-01-01

The current system for ensuring the unity of measurements in the Russian Federation and countries of the former Soviet Union ensures a high quality of dosimetric, radiometric, and spectrometric measurements in accordance with the recommendations of the Consulative Committee on Standards for Measurements of Ionizing Radiations of the International Bureau of Weights and Measures (IBWM), International Organization on Radiological Units (ICRU), International Commission on Radiological Protection (ICRP), International Organization on Legislative Metrology (IOLM), International Atomic Energy Agency (IAEA), World Health Organization (WHO), etc. Frequent collation of the national primary and secondary standards of Russia with those of IBWM and the leading national laboratories of the world facilitate mutual verification of the measurements of ionizing radiations. The scope of scientific and scientific-technical problems that can be solved by using ionizing radiations has expanded significantly in recent years. In this paper the authors consider some pressing problems of the metrology of ionizing radiations which have arisen as a result of this expansion. These include the need for unity and reliability of measurements involved in radiation protection, the measurement of low doses involving low dose rates, ensuring the unity of measurements when monitoring the radiological security of the population, the need for more uniformity on an international scale regarding the basic physical quantities and their units for characterizing radiation fields, determination of the accuracy of measurement of the radiation dose absorbed by an irradiated tissue or organ, and the development of complex standards for ionizing radiations. 5 refs., 1 tab

Ionizing radiation for insect control in grain and grain products

International Nuclear Information System (INIS)

Tilton, E.W.; Brower, J.H.

1987-01-01

A technical review summarizes and discusses information on various aspects of the use of ionizing radiation for the control of insect infestation in grains and grain products. Topics include: the effects of ionizing radiation on insects infesting stored-grain products; the 2 main types of irradiators (electron accelerators; radioisotopes (e.g.: Co-60; Cs-137); dosimetry systems and methodology; variations in radiation resistance by stored-product pests; the proper selection of radiation dose; the effects of combining various treatments (temperature, infrared/microwave radiation, hypoxia, chemicals) with ionizing radiation; sublethal radiation for controlling bulk grain insects; the feeding capacity of irradiated insects; the susceptibility of insecticide-resistant insects to ionizing radiation; and the possible resistance of insects to ionizing radiation. Practical aspects of removing insects from irradiated grain also are discussed

A link between solar events and congenital malformations: Is ionizing radiation enough to explain it?

Science.gov (United States)

Overholt, Andrew C.; Melott, Adrian L.; Atri, Dimitra

2015-03-01

Cosmic rays are known to cause biological effects directly and through ionizing radiation produced by their secondaries. These effects have been detected in airline crews and other specific cases where members of the population are exposed to above average secondary fluxes. Recent work has found a correlation between solar particle events and congenital malformations. In this work we use the results of computational simulations to approximate the ionizing radiation from such events as well as longer-term increases in cosmic ray flux. We find that the amounts of ionizing radiation produced by these events are insufficient to produce congenital malformations under the current paradigm regarding muon ionizing radiation. We believe that further work is needed to determine the correct ionizing radiation contribution of cosmogenic muons. We suggest that more extensive measurements of muon radiation effects may show a larger contribution to ionizing radiation dose than currently assumed.

Atmospheric Ionizing Radiation (AIR) ER-2 Preflight Analysis

Science.gov (United States)

Tai, Hsiang; Wilson, John W.; Maiden, D. L.

1998-01-01

Atmospheric ionizing radiation (AIR) produces chemically active radicals in biological tissues that alter the cell function or result in cell death. The AIR ER-2 flight measurements will enable scientists to study the radiation risk associated with the high-altitude operation of a commercial supersonic transport. The ER-2 radiation measurement flights will follow predetermined, carefully chosen courses to provide an appropriate database matrix which will enable the evaluation of predictive modeling techniques. Explicit scientific results such as dose rate, dose equivalent rate, magnetic cutoff, neutron flux, and air ionization rate associated with those flights are predicted by using the AIR model. Through these flight experiments, we will further increase our knowledge and understanding of the AIR environment and our ability to assess the risk from the associated hazard.

Effects of ionizing radiation on gelatine films added with antioxidant

International Nuclear Information System (INIS)

Kraide, Felipe H.; Inamura, Patricia Y.; Mastro, Nelida L. del

2011-01-01

This work evaluates the effect of ionizing radiation on the gelatin films in presence of antioxidant. Gelatin solutions of glycerine and poly vinil alcohol, with and without the addition were prepared until the complete homogenization. The films were irradiated with 20 and 40 kGy in a electron accelerator, in the presence of air and at the room temperature. The use of ionizing radiation and the addition of antioxidant changed the properties of the film. The result of water absorption test revealed that with increasing of radiation dose occurred a reduction in the absorption, suggesting that happen a reticulation

Effect of ionizing radiation on rat parotid gland

Energy Technology Data Exchange (ETDEWEB)

Boraks, George; Tampelini, Flavio Silva; Pereira, Kleber Fernando; Chopard, Renato Paulo [University of Sao Paulo (USP), SP (Brazil). Inst. of Biomedical Sciences. Dept. of Anatomy]. E-mail: rchopard@usp.br

2008-01-15

A common side effect of radiotherapy used in the treatment of oral cancer is the occurrence of structural and physiological alterations of the salivary glands due to exposure to ionizing radiation, as demonstrated by conditions such as decreased salivary flow. The present study evaluated ultrastructural alterations in the parotid glands of rats receiving a fractionated dose (1,500-cGy) of radiation emitted by a Cesium-137 source and rats that were not subjected to ionizing radiation. After sacrifice, the parotid glands were removed and examined by transmission electron microscopy. Damage such as cytoplasmic vacuolisation, dilatation of the endoplasmic reticulum and destruction of mitochondria, as well as damage to the cellular membrane of acinar cells, were observed. These findings lead to the conclusion that ionizing radiation promotes alterations in the glandular parenchyma, and that these alterations are directly related to the dose level of absorbed radiation. Certain phenomena that appear in the cytoplasm and nuclear material indicate that ionizing radiation causes acinar cell death (apoptosis). (author)

Ionizing and non-ionizing radiation and the risk of childhood cancer-illustrated with domestic radon and radio frequency electromagnetic field exposure

OpenAIRE

Hauri, Dimitri

2013-01-01

Background Children are exposed to many different environmental factors, including exposure to low-dose ionizing radiation and to non-ionizing radiation. Low-dose ionizing radiation comprises anthropogenic modified radiation and natural ionizing radiation from cosmic rays from the atmosphere, terrestrial gamma radiation from radionuclides in rocks and soils and radiation from radon. Non-ionizing radiation comprises optical radiation and radiation from electromagnetic fields. The la...

Occupational radiation protection: Protecting workers against exposure to ionizing radiation. Contributed papers

International Nuclear Information System (INIS)

2003-07-01

Occupational exposure to ionizing radiation can occur in a range of industries, mining and milling; medical institutions, educational and research establishments and nuclear fuel cycle facilities. The term 'occupational exposure' refers to the radiation exposure incurred by a worker, which is attributable to the worker's occupation and committed during a period of work. According to the latest (2000) Report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), an estimated 11 million workers are monitored for exposure to ionizing radiation. They incur radiation doses attributable to their occupation, which range from a small fraction of the global average background exposure to natural radiation up to several times that value. It should be noted that the UNSCEAR 2000 Report describes a downward trend in the exposure of several groups of workers, but it also indicates that occupational exposure is affecting an increasingly large group of people worldwide. The International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation Sources (BSS), which are co-sponsored by, inter alia, the International Atomic Energy Agency (IAEA), the International Labour Organization (ILO), the OECD Nuclear Energy Agency (NEA) and the World Health Organization (WHO), establish a system of radiation protection which includes radiation dose limits for occupational exposure. Guidance supporting the requirements of the BSS for occupational protection is provided in three interrelated Safety Guides, jointly sponsored by the IAEA and the ILO. These Guides describe, for example, the implications for employers in discharging their main responsibilities (such as setting up appropriate radiation protection programmes) and similarly for workers (such as properly using the radiation monitoring devices provided to them). The IAEA i organized its first International Conference on Occupational Radiation Protection. The

Ionizing radiations

International Nuclear Information System (INIS)

2009-01-01

After having recalled some fundamental notions and measurement units related to ionizing radiations, this document describes various aspects of natural and occupational exposures: exposure modes and sources, exposure levels, biological effects, health impacts. Then, it presents prevention principles aimed at, in an occupational context of use of radiation sources (nuclear industry excluded), reducing and managing these exposures: risk assessment, implementation of safety from the front end. Some practical cases illustrate the radiation protection approach. The legal and regulatory framework is presented: general notions, worker exposure, measures specific to some worker categories (pregnant and breast feeding women, young workers, temporary workers). A last part describes what is to be done in case of incident or accident (dissemination of radioactive substances from unsealed sources, anomaly occurring when using a generator or a sealed source, post-accident situation)

Occupational radiation exposure to low doses of ionizing radiation and female breast cancer

International Nuclear Information System (INIS)

Adelina, P.; Bliznakov, V.; Bairacova, A.

2003-01-01

The aim of this study is to examine the relationship between past occupational radiation exposure to low doses of ionizing radiation and cases of diagnosed and registered breast cancer [probability of causation - PC] among Bulgarian women who have used different ionizing radiation sources during their working experience. The National Institute of Health (NIH) in US has developed a method for estimating the probability of causation (PC) between past occupational radiation exposure to low doses of ionizing radiation and cases of diagnosed cancer. We have used this method. A group of 27 women with diagnosed breast cancer has been studied. 11 of them are former workers in NPP - 'Kozloduy', and 16 are from other sites using different sources of ionizing radiation. Analysis was performed for 14 women, for whom full personal data were available. The individual radiation dose for each of them is below 1/10 of the annual dose limit, and the highest cumulative dose for a period of 14 years of occupational exposure is 50,21 mSv. The probability of causation (PC) values in all analyzed cases are below 1%, which confirms the extremely low probability of causation (PC) between past occupational radiation exposure to low doses of ionizing radiation and occurring cases of breast cancer. (orig.)

Tooth-germ damage by ionizing radiation

International Nuclear Information System (INIS)

Sobkowiak, E.M.; Beetke, E.; Bienengraeber, V.; Held, M.; Kittner, K.H.

1977-01-01

Experiments on animals (four-week-old dogs) were conducted in an investigation made to study the possibility of dose-dependent tooth-germ damage produced by ionizing radiation. The individual doses were 50 R and 200 R, respectively, and they were administered once to three times at weekly intervals. Hyperemia and edemata could be observed on tooth-germ pulps from 150 R onward. Both of these conditions became more acute as the radiation dose increased (from 150 R to 600 R). Possible damage to both the dentin and enamel is pointed out. (author)

Neurophysiological appropriateness of ionizing radiation effects

International Nuclear Information System (INIS)

Nyagu, A.I.; Loganovsky, K.N.

1997-01-01

The goal of this study was to compare bioelectrical activity of the brain in remote period of acute radiation sickness (ARS), chronic and prenatal irradiation as a result of the Chernobyl disaster. Registration of computerized 19-channel EEG, visual and somato-sensory evoked potentials have been carried out for 70 patients who had a verified ARS, 100 Chernobyl disaster survivors, who have been working in the Chernobyl exclusion zone since 1986-87 during 5 and more years, 50 prenatally irradiated children, and relevant controls. The relative risks of neurophysiological abnormalities are 4.5 for the ARS-patients, 3.6 for the chronically irradiated persons and 3.7 for the prenatally irradiated children. The data obtained testify to possibility of radiation-induced neurophysiological abnormalities in examined Chernobyl accident survivors which seems to be non-stochastic effects of ionizing radiation. For all examined irradiated patients it was typically an increasing of δ- and β- powers of EEG, particularly, in the frontal lobe shifted to the left fronto-temporal region, but spectral power of both θ- and α-range was significantly depressed. Aforesaid signs together with data of evoked potentials reflect the structural and functional abnormalities of limbic system and the left hemisphere as the first revealed neurophysiological appropriateness of ionizing radiation effects. (author)

Neurophysiological appropriateness of ionizing radiation effects

Energy Technology Data Exchange (ETDEWEB)

Nyagu, A I; Loganovsky, K N [Department of Neurology, Inst. of Clinical Radiology, Scientific Centre for Radiation Medicine of Academy of Medical Sciences of Ukraine, Kiev (Ukraine)

1997-11-01

The goal of this study was to compare bioelectrical activity of the brain in remote period of acute radiation sickness (ARS), chronic and prenatal irradiation as a result of the Chernobyl disaster. Registration of computerized 19-channel EEG, visual and somato-sensory evoked potentials have been carried out for 70 patients who had a verified ARS, 100 Chernobyl disaster survivors, who have been working in the Chernobyl exclusion zone since 1986-87 during 5 and more years, 50 prenatally irradiated children, and relevant controls. The relative risks of neurophysiological abnormalities are 4.5 for the ARS-patients, 3.6 for the chronically irradiated persons and 3.7 for the prenatally irradiated children. The data obtained testify to possibility of radiation-induced neurophysiological abnormalities in examined Chernobyl accident survivors which seems to be non-stochastic effects of ionizing radiation. For all examined irradiated patients it was typically an increasing of {delta}- and {beta}- powers of EEG, particularly, in the frontal lobe shifted to the left fronto-temporal region, but spectral power of both {theta}- and {alpha}-range was significantly depressed. Aforesaid signs together with data of evoked potentials reflect the structural and functional abnormalities of limbic system and the left hemisphere as the first revealed neurophysiological appropriateness of ionizing radiation effects. (author). 25 refs.

Protection criteria from the non-ionizing radiations

International Nuclear Information System (INIS)

Touzet, Rodolfo E.

2004-01-01

The first objective of the protection philosophy is to determinate the relation reason-effect in order to establish the exposition thresholds to acceptable values. To establish the radioprotection criteria is important to considerate the following: a-) The damage and effects of the non-ionizing radiation; b-) The physical aspects of the fields exposition; and c-) The dosimetry of the involucrate tissues. The non-ionizing radiation includes the optics radiations (ultraviolet, visible, infrared and laser), and the electromagnetic radiations (microwave, radars, magnetic and electrostatics fields)

Fast Atom Ionization in Strong Electromagnetic Radiation

Science.gov (United States)

Apostol, M.

2018-05-01

The Goeppert-Mayer and Kramers-Henneberger transformations are examined for bound charges placed in electromagnetic radiation in the non-relativistic approximation. The consistent inclusion of the interaction with the radiation field provides the time evolution of the wavefunction with both structural interaction (which ensures the bound state) and electromagnetic interaction. It is shown that in a short time after switching on the high-intensity radiation the bound charges are set free. In these conditions, a statistical criterion is used to estimate the rate of atom ionization. The results correspond to a sudden application of the electromagnetic interaction, in contrast with the well-known ionization probability obtained by quasi-classical tunneling through classically unavailable non-stationary states, or other equivalent methods, where the interaction is introduced adiabatically. For low-intensity radiation the charges oscillate and emit higher-order harmonics, the charge configuration is re-arranged and the process is resumed. Tunneling ionization may appear in these circumstances. Extension of the approach to other applications involving radiation-induced charge emission from bound states is discussed, like ionization of molecules, atomic clusters or proton emission from atomic nuclei. Also, results for a static electric field are included.

Radiation ionization is an underestimated industrial technique

International Nuclear Information System (INIS)

Anon.

1999-01-01

Industrial radiation ionization requires electron beams coming from an accelerator or gamma radiation from a radioactive source (Co 60 ). The energy deposed in the irradiated material modifies its chemical bounds or kills micro-organisms. This process is used in medical material sterilization, in disinfestation of stored and packaged food products, in the production of plastic, in the coloring of glass, in the hardening of electronic components and in the modification of the properties of semi-conductors. For 40 years radiation ionization has been investigated, UNO (United Nations Organization) and WHO (World Health Organisation) recommend it for food processing. With a growing rate of 15% per year for the last 15 years, radiation ionization is now widely used. More than 170 gamma irradiation facilities are operating throughout the world. (A.C.)

Electrical pulse burnout of transistors in intense ionizing radiation

International Nuclear Information System (INIS)

Hartman, E.F.; Evans, D.C.

1975-01-01

Tests examining possible synergistic effects of electrical pulses and ionizing radiation on transistors were performed and energy/power thresholds for transistor burnout determined. The effect of ionizing radiation on burnout thresholds was found to be minimal, indicating that electrical pulse testing in the absence of radiation produces burnout-threshold results which are applicable to IEMP studies. The conditions of ionized transistor junctions and radiation induced current surges at semiconductor device terminals are inherent in IEMP studies of electrical circuits

Ionizing radiation changes the electronic properties of melanin and enhances the growth of melanized fungi.

Science.gov (United States)

Dadachova, Ekaterina; Bryan, Ruth A; Huang, Xianchun; Moadel, Tiffany; Schweitzer, Andrew D; Aisen, Philip; Nosanchuk, Joshua D; Casadevall, Arturo

2007-05-23

Melanin pigments are ubiquitous in nature. Melanized microorganisms are often the dominating species in certain extreme environments, such as soils contaminated with radionuclides, suggesting that the presence of melanin is beneficial in their life cycle. We hypothesized that ionizing radiation could change the electronic properties of melanin and might enhance the growth of melanized microorganisms. Ionizing irradiation changed the electron spin resonance (ESR) signal of melanin, consistent with changes in electronic structure. Irradiated melanin manifested a 4-fold increase in its capacity to reduce NADH relative to non-irradiated melanin. HPLC analysis of melanin from fungi grown on different substrates revealed chemical complexity, dependence of melanin composition on the growth substrate and possible influence of melanin composition on its interaction with ionizing radiation. XTT/MTT assays showed increased metabolic activity of melanized C. neoformans cells relative to non-melanized cells, and exposure to ionizing radiation enhanced the electron-transfer properties of melanin in melanized cells. Melanized Wangiella dermatitidis and Cryptococcus neoformans cells exposed to ionizing radiation approximately 500 times higher than background grew significantly faster as indicated by higher CFUs, more dry weight biomass and 3-fold greater incorporation of (14)C-acetate than non-irradiated melanized cells or irradiated albino mutants. In addition, radiation enhanced the growth of melanized Cladosporium sphaerospermum cells under limited nutrients conditions. Exposure of melanin to ionizing radiation, and possibly other forms of electromagnetic radiation, changes its electronic properties. Melanized fungal cells manifested increased growth relative to non-melanized cells after exposure to ionizing radiation, raising intriguing questions about a potential role for melanin in energy capture and utilization.

NMR Metabolomics in Ionizing Radiation

Energy Technology Data Exchange (ETDEWEB)

Hu, Jian Z.; Xiao, Xiongjie; Hu, Mary Y.

2016-09-08

Ionizing radiation is an invisible threat that cannot be seen, touched or smelled and exist either as particles or waves. Particle radiation can take the form of alpha, beta or neutrons, as well as high energy space particle radiation such as high energy iron, carbon and proton radiation, etc. (1) Non-particle radiation includes gamma- and x-rays. Publically, there is a growing concern about the adverse health effects due to ionizing radiation mainly because of the following facts. (a) The X-ray diagnostic images are taken routinely on patients. Even though the overall dosage from a single X-ray image such as a chest X-ray scan or a CT scan, also called X-ray computed tomography (X-ray CT), is low, repeated usage can cause serious health consequences, in particular with the possibility of developing cancer (2, 3). (b) Human space exploration has gone beyond moon and is planning to send human to the orbit of Mars by the mid-2030s. And a landing on Mars will follow.

Biological effects of ionizing radiation

International Nuclear Information System (INIS)

Gisone, Pablo; Perez, Maria R.

2001-01-01

It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

Interactive visual intervention planning in particle accelerator environments with ionizing radiation

CERN Document Server

Fabry, Thomas

Radiation is omnipresent. It has many interesting applications: in medicine, where it allows curing and diagnosing patients; in communication, where modern communication systems make use of electromagnetic radiation; and in science, where it is used to discover the structure of materials; to name a few. Physically, radiation is a process in which particles or waves travel through any kind of material, usually air. Radiation can be very energetic, in which case it can break the atoms of ordinary matter (ionization). If this is the case, radiation is called ionizing. It is known that ionizing radiation can be far more harmful to living beings than non-ionizing radiation. In this dissertation, we are concerned with ionizing radiation. Naturally occurring ionizing radiation in the form of radioactivity is a most natural phenomenon. Almost everything is radioactive: there is radiation emerging from the soil, it is in the air, and the whole planet is constantly undergoing streams of energetic cosmic radiation. Sinc...

Effects of total dose of ionizing radiation on integrated circuits

Energy Technology Data Exchange (ETDEWEB)

Silveira, Marcilei A.G.; Cirne, K.H.; Gimenez, S.; Santos, R.B.B. [Centro Universitario da FEI, Sao Bernardo do Campo, SP (Brazil); Added, N.; Barbosa, M.D.L.; Medina, N.H.; Tabacniks, M.H. [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Lima, J.A. de; Seixas Junior, L.E.; Melo, W. [Centro de Tecnologia da Informacao Paulo Archer, Sao Paulo, SP (Brazil)

2011-07-01

Full text: The study of ionizing radiation effects on materials used in electronic devices is of great relevance for the progress of global technological development and, particularly, it is a necessity in some strategic areas in Brazil. Electronic circuits are strongly influenced by radiation and the need for IC's featuring radiation hardness is largely growing to meet the stringent environment in space electronics. On the other hand, aerospace agencies are encouraging both scientific community and semiconductors industry to develop hardened-by-design components using standard manufacturing processes to achieve maximum performance, while significantly reducing costs. To understand the physical phenomena responsible for changes in devices exposed to ionizing radiation several kinds of radiation should then be considered, among them alpha particles, protons, gamma and X-rays. Radiation effects on the integrated circuits are usually divided into two categories: total ionizing dose (TID), a cumulative dose that shifts the threshold voltage and increases transistor's off-state current; single events effects (SEE), a transient effect which can deposit charge directly into the device and disturb the properties of electronic circuits. TID is one of the most common effects and may generate degradation in some parameters of the CMOS electronic devices, such as the threshold voltage oscillation, increase of the sub-threshold slope and increase of the off-state current. The effects of ionizing radiation are the creation of electron-hole pairs in the oxide layer changing operation mode parameters of the electronic device. Indirectly, there will be also changes in the device due to the formation of secondary electrons from the interaction of electromagnetic radiation with the material, since the charge carriers can be trapped both in the oxide layer and in the interface with the oxide. In this work we have investigated the behavior of MOSFET devices fabricated with

The toxic effects of ionizing radiations

International Nuclear Information System (INIS)

Draghita Payet, A.C.

2006-06-01

The sources of radiations to which the human body is subjected are of natural or artificial origin and the irradiation of the human body can take place either by internal or external way. The ionizing radiations act at several levels of the human body, the main thing being the molecule of DNA. The ionizing radiations have no specificity, the effects on the human body can be: somatic, genetic or hereditary, teratogen. In the case of a human being irradiation, we proceed to the diagnosis and to the treatment of the irradiated person, however, to decrease the incidence of injuries we use the radiation protection. The treatment if necessary will be established according to the irradiation type. (N.C.)

Radiobiology: Biologic effects of ionizing radiations

International Nuclear Information System (INIS)

Held, K.D.

1987-01-01

The biologic effects after exposure to ionizing radiation, such as cell death or tissue injury, result from a chain of complex physical, chemical, metabolic, and histologic events. The time scale of these radiation actions spans many orders of magnitude. The physical absorption of ionizing radiation occurs in about 10 -18 s, while late carcinogenic and genetic effects are expressed years or even generations later. Collectively, these effects form the science of radiobiology. Many of the concepts discussed in this chapter have been developed through the study of effects generated in tissues by external radiation sources, but they apply generally and often specifically to internally distributed radiopharmaceuticals which form the central topic of this book

Personnel ionizing radiation dosimeter

International Nuclear Information System (INIS)

Williams, R.A.

1975-01-01

A dosimeter and method for use by personnel working in an area of mixed ionizing radiation fields for measuring and/or determining the effective energy of x- and gamma radiation; beta, x-, and gamma radiation dose equivalent to the surface of the body; beta, x-, and gamma radiation dose equivalent at a depth in the body; the presence of slow neutron, fast neutron dose equivalent; and orientation of the person wearing the dosimeter to the source of radiation is disclosed. Optionally integrated into this device and method are improved means for determining neutron energy spectrum and absorbed dose from fission gamma and neutron radiation resulting from accidental criticality

Application of ionizing radiation to preservation of mushrooms

International Nuclear Information System (INIS)

Smierzchalska, K.; Gubrynowicz, E.

1979-01-01

The influence of ionizing radiation on prolongation of preservation time and quality of mushrooms is discussed. Some numerical data are cited. The influence of ionizing radiation on growth rate and physiological processes is also presented. (A.S.)

Taurine Protects Mouse Spermatocytes from Ionizing Radiation-Induced Damage Through Activation of Nrf2/HO-1 Signaling.

Science.gov (United States)

Yang, Wenjun; Huang, Jinfeng; Xiao, Bang; Liu, Yan; Zhu, Yiqing; Wang, Fang; Sun, Shuhan

2017-01-01

The increasing prevalence of ionizing radiation exposure has inevitably raised public concern over the potential detrimental effects of ionizing radiation on male reproductive system function. The detection of drug candidates to prevent reproductive system from damage caused by ionizing radiation is urgent. We aimed to investigate the protective role of taurine on the injury of mouse spermatocyte-derived cells (GC-2) subjected to ionizing radiation. mouse spermatocytes (GC-2 cells) were exposed to ionizing radiation with or without treatment of Taurine. The effect of ionizing radiation and Taurine treatment on GC-2 cells were evaluated by cell viability assay (CCK8), cell cycle and apoptosis. The relative protein abundance change was determined by Western blotting. The siRNA was used to explore whether Nrf2 signaling was involved in the cytoprotection of Taurine. Taurine significantly inhibited the decrease of cell viability, percentage of apoptotic cells and cell cycle arrest induced by ionizing radiation. Western blot analysis showed that taurine significantly limited the ionizing radiation-induced down-regulation of CyclinB1 and CDK1, and suppressed activation of Fas/FasL system pathway. In addition, taurine treatment significantly increased the expression of Nrf2 and HO-1 in GC-2 cells exposed to ionizing radiation, two components in antioxidant pathway. The above cytoprotection of Taurine was blocked by siNrf2. Our results demonstrate that taurine has the potential to effectively protect GC-2 cells from ionizing radiation- triggered damage via upregulation of Nrf2/HO-1 signaling. © 2017 The Author(s). Published by S. Karger AG, Basel.

Pregnancy and ionizing radiation

International Nuclear Information System (INIS)

Plataniotis, Th.N.; Nikolaou, K.I.; Syrgiamiotis, G.V.; Dousi, M.; Panou, Th.; Georgiadis, K.; Bougias, C.

2008-01-01

Full text: In this report there will be presented the effects of ionizing radiation at the fetus and the necessary radioprotection. The biological results on the fetus, caused by the irradiation, depend on the dose of ionizing radiation that it receives and the phase of its evolution. The imminent effects of the irradiation can cause the fetus death, abnormalities and mental retardation, which are the result of overdose. The effects are carcinogenesis and leukemia, which are relative to the acceptable irradiating dose at the fetus and accounts about 0,015 % per 1 mSv. The effects of ionizing radiation depend on the phase of the fetus evolution: 1 st phase (1 st - 2 nd week): presence of low danger; 2 nd phase (3 rd - 8 th week): for doses >100 mSv there is the possibility of dysplasia; 3 rd phase (8 th week - birth): this phase concerns the results with a percentage 0,015 % per 1 mSv. We always must follow some rules of radioprotection and especially at Classical radiation use of necessary protocols (low dose), at Nuclear Medicine use of the right radioisotope and the relative field of irradiation for the protection of the adjacent healthy tissues and at Radiotherapy extreme caution is required regarding the dose and the treatment. In any case, it is forbidden to end a pregnancy when the pregnant undergoes medical exams, in which the uterus is in the beam of irradiation. The radiographer must always discuss the possibility of pregnancy. (author)

THE ROLE OF RADIATION ACCIDENTS AND INDUSTRIAL APPLICATIONS OF IONIZING RADIATION SOURCES IN THE PROBLEM OF RADIATION DAMAGE

OpenAIRE

Кіхтенко, Ігор Миколайович

2016-01-01

Subject of research – the relevance of radiation damage at modern development of industry and medicine. In the world of radiation sources used in different fields of practice and their application in the future will increase, which greatly increases the likelihood of injury in a significant contingent of people.Research topic – the definition of the role of nuclear energy and the industrial use of ionizing radiation sources in the problem of radiation damage. The purpose of research – identif...

Ionizing radiation in the education of medicine

International Nuclear Information System (INIS)

Ivanova, N.

2016-01-01

Physics is a fundamental science that finds its applications in all areas of our lives. Its application in modern medicine is undeniable. In today’s medical practice special attention is dedicated to the use of ionizing radiation. The wide range of modern science and technology offers enormous possibilities for creation and implementation of new equipment using adequate doses of ionizing radiation. For accurate medical diagnostics and effective treatment of patients, this type of equipment must provide the necessary information to the physicians. On the other hand, the physicians should possess enough knowledge in the relative field of medicine. This paper contains information about the knowledge communicated to the students of the graduate program Medical Physics and Biophysics in the discipline Medicine in the first year of graduate study at the Medical University “Prof. Dr. Paraskev Stoyanov” of Varna. Firstly, we discuss the topics in the lectures of these two disciplines, concerning knowledge about ionizing radiation. Secondly, the respective laboratory exercises are described that illustrate the lectures in the graduate programs Medical Physics and Biophysics. Keywords: ionizing radiation, education, medicine, medical physics, biophysics

Effects of ionizing radiations on proteins

International Nuclear Information System (INIS)

Maire, M. le; Foresta, B. de; Viel, A.; Thauvette, L.; Beauregard, G.; Potier, M.

1990-01-01

We have reinvestigated the use of ionizing radiations to measure the molecular mass of water-soluble or membrane proteins. Exposure of purified standard proteins to increasing doses of ionizing radiation causes progressive fragmentation of the native protein into defined peptide patterns. The coloured band corresponding to the intact protein was measured on the SDS gel as a function of dose to determine the dose (D 37.t ) corresponding to 37% of the initial amount of unfragmented protein deposited on the gel. This led to a calibration curve and the known molecular mass of the standard proteins. However, we have to conclude that this method is useless to determine the state of aggregation of a protein, since, for all the oligomers tested, the best fit was obtained by using the protomeric molecular mass, suggesting that there is no energy transfer between protomers. Furthermore, SDS greatly increases the fragmentation rate of proteins, which suggests additional calibration problems for membrane proteins in detergent or in the lipid bilayer. The main drawback of the technique is that some proteins behaved anomalously, leading to very large errors in the apparent target size as compared with true molecular mass. It is thus unreliable to apply the radiation method for absolute molecular-mass determination. We then focused on the novel finding that discrete fragmentation of proteins occurs at preferential sites, and this was studied with aspartate transcarbamylase. (author)

Oncology Patient Perceptions of the Use of Ionizing Radiation in Diagnostic Imaging.

Science.gov (United States)

Steele, Joseph R; Jones, Aaron K; Clarke, Ryan K; Giordano, Sharon H; Shoemaker, Stowe

2016-07-01

To measure the knowledge of oncology patients regarding use and potential risks of ionizing radiation in diagnostic imaging. A 30-question survey was developed and e-mailed to 48,736 randomly selected patients who had undergone a diagnostic imaging study at a comprehensive cancer center between November 1, 2013 and January 31, 2014. The survey was designed to measure patients' knowledge about use of ionizing radiation in diagnostic imaging and attitudes about radiation. Nonresponse bias was quantified by sending an abbreviated survey to patients who did not respond to the original survey. Of the 48,736 individuals who were sent the initial survey, 9,098 (18.7%) opened it, and 5,462 (11.2%) completed it. A total of 21.7% of respondents reported knowing the definition of ionizing radiation; 35.1% stated correctly that CT used ionizing radiation; and 29.4% stated incorrectly that MRI used ionizing radiation. Many respondents did not understand risks from exposure to diagnostic doses of ionizing radiation: Of 3,139 respondents who believed that an abdominopelvic CT scan carried risk, 1,283 (40.9%) believed sterility was a risk; 669 (21.3%) believed heritable mutations were a risk; 657 (20.9%) believed acute radiation sickness was a risk; and 135 (4.3%) believed cataracts were a risk. Most patients and caregivers do not possess basic knowledge regarding the use of ionizing radiation in oncologic diagnostic imaging. To ensure health literacy and high-quality patient decision making, efforts to educate patients and caregivers should be increased. Such education might begin with information about effects that are not risks of diagnostic imaging. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

Genetic variation in resistance to ionizing radiation

International Nuclear Information System (INIS)

Ayala, F.J.

1991-01-01

We proposed an investigation of genetically-determined individual differences in sensitivity to ionizing radiation. The model organism is Drosophila melanogaster. The gene coding for Cu,Zn superoxide dismutase (SOD) is the target locus, but the effects of variation in other components of the genome that modulate SOD levels are also taken into account. SOD scavenges oxygen radicals generated during exposure to ionizing radiation. It has been shown to protect against ionizing radiation damage to DNA, viruses, bacteria, mammalian cells, whole mice, and Drosophila. Two alleles, S and F, are commonly found in natural populations of D. melanogaster; in addition we have isolated from a natural population ''null'' (CA1) mutant that yields only 3.5% of normal SOD activity. The S, F, and CA1 alleles provide an ideal model system to investigate SOD-dependent radioresistance, because each allele yields different levels of SOD, so that S > F >> CA1. The roles of SOD level in radioresistance are being investigated in a series of experiments that measure the somatic and germ-line effects of increasing doses of ionizing radiation. In addition, we have pursued an unexpected genetic event-namely the nearly simultaneous transformation of several lines homozygous for the SOD ''null'' allele into predominately S lines. Using specifically designed probes and DNA amplification by means of the Tag polymerase chain reaction (PCR) we have shown that (1) the null allele was still present in the transformed lines, but was being gradually replaced by the S allele as a consequence of natural selection; and (2) that the transformation was due to the spontaneous deletion of a 0.68 Kb truncated P-element, the insertion of which is characteristic of the CA1 null allele

Six categories of ionizing radiation quantities practical in various fields

International Nuclear Information System (INIS)

Zheng Junzheng; Zhuo Weihai

2011-01-01

This paper is the part of review on the evolvement of the systems for ionizing radiation quantities and units. In the paper, for better understanding and correct use of the relevant quantities of ionizing radiation, the major ionizing radiation quantities in various fields are divided into six categories. (authors)

The health effects of low-dose ionizing radiation

International Nuclear Information System (INIS)

Dixit, A.N.; Dixit, Nishant

2012-01-01

It has been established by various researches, that high doses of ionizing radiation are harmful to health. There is substantial controversy regarding the effects of low doses of ionizing radiation despite the large amount of work carried out (both laboratory and epidemiological). Exposure to high levels of radiation can cause radiation injury, and these injuries can be relatively severe with sufficiently high radiation doses. Prolonged exposure to low levels of radiation may lead to cancer, although the nature of our response to very low radiation levels is not well known at this time. Many of our radiation safety regulations and procedures are designed to protect the health of those exposed to radiation occupationally or as members of the public. According to the linear no-threshold (LNT) hypothesis, any amount, however small, of radiation is potentially harmful, even down to zero levels. The threshold hypothesis, on the other hand, emphasizes that below a certain threshold level of radiation exposure, any deleterious effects are absent. At the same time, there are strong arguments, both experimental and epidemiological, which support the radiation hormesis (beneficial effects of low-level ionizing radiation). These effects cannot be anticipated by extrapolating from harmful effects noted at high doses. Evidence indicates an inverse relationship between chronic low-dose radiation levels and cancer incidence and/or mortality rates. Examples are drawn from: 1) state surveys for more than 200 million people in the United States; 2) state cancer hospitals for 200 million people in India; 3) 10,000 residents of Taipei who lived in cobalt-60 contaminated homes; 4) high-radiation areas of Ramsar, Iran; 5) 12 million person-years of exposed and carefully selected control nuclear workers; 6) almost 300,000 radon measurements of homes in the United States; and 7) non-smokers in high-radon areas of early Saxony, Germany. This evidence conforms to the hypothesis that

Non-ionizing radiation protection training manual for radiation control. Lectures, demonstrations, laboratories and tours on the course on non-ionizing radiations. Final report

International Nuclear Information System (INIS)

Morgan, K.Z.; Burkhart, R.L.

1976-03-01

In late 1974, consultation with the National Training Coordination Committee of the Conference of Radiation Control Program Directors determined that State personnel needed training in order to fulfill their responsibility with respect to the growing number of non-ionizing radiation sources. A contract was awarded to the Georgia Institute of Technology to develop materials for a training program on non-ionizing radiation protection, pilot test these materials in a two-week presentation for Federal, State, and local government health personnel, and revise the materials as needed to produce a self-contained training manual. The materials were pilot-tested in March 1976, and then revised to provide the final manual. The course consists of three parts (1) general discussions of basic principles, properties, propagation and behavior of all types of non-ionizing radiations (2) an indepth study of all types and applications of coherent (laser) radiations, and (3) a study of ultraviolet, infrared, microwave, r.f., longwave and mechanical radiations as they may be used to have applications in hospitals and other medical institutions

Sterilization by ionizing radiation comparative evaluation

International Nuclear Information System (INIS)

Tata, A.; Giuliani, S.

1996-01-01

Sterilization of surgical and medical devices by ionizing radiation (gamma or accelerated electron beams) is currently regarded as one of the main industrial-scale applications of radiation technology processes. Considering the most widely utilized chemical-physical methods (i.e. ethylene oxide (EtO) fumigation and radiation treatment), about 10-12 millions m(3) of surgical and medical devices are estimated to be processed yearly all around the world, of which 7 on beams. Due to the increasing demand for reusable and single-use devices, and the need of assuring their sterility in order to prevent, as much as possible, the diffusion of serious infective diseases (among which for instance Aids), the market of sterilization of these items is considerably expanding. In the general depicted scenario, radiation technologies are expected to gain a leading role, even a part from their economic attractiveness, as an alternative to EtO treatment, which is more and more considered as responsible for increasing environmental, social and public health problems

F--Ray: A new algorithm for efficient transport of ionizing radiation

Science.gov (United States)

Mao, Yi; Zhang, J.; Wandelt, B. D.; Shapiro, P. R.; Iliev, I. T.

2014-04-01

We present a new algorithm for the 3D transport of ionizing radiation, called F2-Ray (Fast Fourier Ray-tracing method). The transfer of ionizing radiation with long mean free path in diffuse intergalactic gas poses a special challenge to standard numerical methods which transport the radiation in position space. Standard methods usually trace each individual ray until it is fully absorbed by the intervening gas. If the mean free path is long, the computational cost and memory load are likely to be prohibitive. We have developed an algorithm that overcomes these limitations and is, therefore, significantly more efficient. The method calculates the transfer of radiation collectively, using the Fast Fourier Transform to convert radiation between position and Fourier spaces, so the computational cost will not increase with the number of ionizing sources. The method also automatically combines parallel rays with the same frequency at the same grid cell, thereby minimizing the memory requirement. The method is explicitly photon-conserving, i.e. the depletion of ionizing photons is guaranteed to equal the photoionizations they caused, and explicitly obeys the periodic boundary condition, i.e. the escape of ionizing photons from one side of a simulation volume is guaranteed to be compensated by emitting the same amount of photons into the volume through the opposite side. Together, these features make it possible to numerically simulate the transfer of ionizing photons more efficiently than previous methods. Since ionizing radiation such as the X-ray is responsible for heating the intergalactic gas when first stars and quasars form at high redshifts, our method can be applied to simulate thermal distribution, in addition to cosmic reionization, in three-dimensional inhomogeneous cosmological density field.

Ionizing radiation regulations and the dental practitioner: 1. The nature of ionizing radiation and its use in dentistry.

Science.gov (United States)

Rout, John; Brown, Jackie

2012-04-01

Legislation governing the use of ionizing radiation in the workplace and in medical treatment first became law in 1985 and 1988, being superseded by the Ionizing Radiations Regulations 1999 (IRR99) and the Ionizing Radiation (Medical Exposure) Regulations 2000, (IR(ME)R 2000), respectively. This legislation ensures a safe environment in which to work and receive treatment and requires that those involved in the radiographic process must be appropriately trained for the type of radiographic practice they perform. A list of the topics required is detailed in Schedule 2 of IR(ME)R 2000 and is paraphrased in Table 1, with the extent and amount of knowledge required depending on the type of radiographic practice undertaken. Virtually all dental practitioners undertake radiography as part of their clinical practice. Legislation requires that users of radiation, including dentists and members of the dental team, understand the basic principles of radiation physics, hazards and protection, and are able to undertake dental radiography safely with the production of high quality, diagnostic images.

Metrology of ionizing radiations and environmental measurements

International Nuclear Information System (INIS)

Nourreddine, Abdel-Mjid

2008-01-01

The subject of radiation protection covers all measurements taken by the authorities to ensure protection of the population and its environment against the harmful effects of ionizing radiation. Dosimetry occupies an important place in this field, because it makes it possible to consider and to quantify the risk of using radiations in accordance with the prescribed limits. In this course, we will review the fundamental concepts used in the metrology and dosimetry of ionizing radiations. After classification of ionizing radiations according to their interactions with biological matter, we will present the various quantities and units brought into play and in particular the new operational quantities that are good estimators raising protection standards. They are directly connected to the annual limits of effective dose and of equivalent dose defined in the French regulation relating to the protection of the population and of workers against ionizing radiations. The average natural exposure of the population in France varies between 2 to 2.5 mSv per year, depending on geographic location. It comes principally from three sources: cosmic radiation, radioactive elements contained in the ground and radioactive elements that we absorb when breathing or eating. Radon, which is a naturally occurring radioactive gas, is a public health risk and represents 30% of the exposure. Finally, we will give some applications of dosimetry and environmental measurements developed recently at RaMsEs/IPHC laboratory of Strasbourg. (author)

Professional exposure to ionizing radiation some hematological cytomorfological and immunological tests

International Nuclear Information System (INIS)

Trajkovicj, M.; Veljkovicj, D.; Barjaktarevicj, N.; Kosticj, V.; Brkicj, S.; Pendicj, B.

1977-01-01

The paper represents results of some hematological, cytomorphological and immunological tests for persons professionally exposed to ionizing radiations. Number of leucocytes, neutrophil granulocytes and lymphocytes do not show statistically significant differences between the exposed and control groups. An increase of binucleated lymphocytes and chromosome abberations is registered, the second being statistically significant in comparison to the control group. A small depression in cellular immunity is observed for several persons working with ionizing radiation for a longer period

21 CFR 579.22 - Ionizing radiation for treatment of animal diets.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ionizing radiation for treatment of animal diets..., AND HANDLING OF ANIMAL FEED AND PET FOOD Radiation and Radiation Sources § 579.22 Ionizing radiation for treatment of animal diets. Ionizing radiation for treatment of complete diets for animals may be...

Influence of Dust Loading on Atmospheric Ionizing Radiation on Mars

Science.gov (United States)

Norman, Ryan B.; Gronoff, Guillaume; Mertens, Christopher J.

2014-01-01

Measuring the radiation environment at the surface of Mars is the primary goal of the Radiation Assessment Detector on the NASA Mars Science Laboratory's Curiosity rover. One of the conditions that Curiosity will likely encounter is a dust storm. The objective of this paper is to compute the cosmic ray ionization in different conditions, including dust storms, as these various conditions are likely to be encountered by Curiosity at some point. In the present work, the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety model, recently modified for Mars, was used along with the Badhwar & O'Neill 2010 galactic cosmic ray model. In addition to galactic cosmic rays, five different solar energetic particle event spectra were considered. For all input radiation environments, radiation dose throughout the atmosphere and at the surface was investigated as a function of atmospheric dust loading. It is demonstrated that for galactic cosmic rays, the ionization depends strongly on the atmosphere profile. Moreover, it is shown that solar energetic particle events strongly increase the ionization throughout the atmosphere, including ground level, and can account for the radio blackout conditions observed by the Mars Advanced Radar for Subsurface and Ionospheric Sounding instrument on the Mars Express spacecraft. These results demonstrate that the cosmic rays' influence on the Martian surface chemistry is strongly dependent on solar and atmospheric conditions that should be taken into account for future studies.

Simulation and measurement of total ionizing dose radiation induced image lag increase in pinned photodiode CMOS image sensors

Energy Technology Data Exchange (ETDEWEB)

Liu, Jing [School of Materials Science and Engineering, Xiangtan University, Hunan (China); State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China); Chen, Wei, E-mail: chenwei@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China); Wang, Zujun, E-mail: wangzujun@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China); Xue, Yuanyuan; Yao, Zhibin; He, Baoping; Ma, Wuying; Jin, Junshan; Sheng, Jiangkun; Dong, Guantao [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an (China)

2017-06-01

This paper presents an investigation of total ionizing dose (TID) induced image lag sources in pinned photodiodes (PPD) CMOS image sensors based on radiation experiments and TCAD simulation. The radiation experiments have been carried out at the Cobalt −60 gamma-ray source. The experimental results show the image lag degradation is more and more serious with increasing TID. Combining with the TCAD simulation results, we can confirm that the junction of PPD and transfer gate (TG) is an important region forming image lag during irradiation. These simulations demonstrate that TID can generate a potential pocket leading to incomplete transfer.

Legislations for regulating the work with ionizing radiations in the arab counties a comparative analytical study

International Nuclear Information System (INIS)

El-Baroudy, M.M.

2005-01-01

In the framework of the developments taking place in nuclear sciences and technologies during the twentieth century and the resulting increase of useful applications of these technologies, the international efforts aiming at helping different countries to establish nuclear safety systems. This was also increased through the promulgation of legislations that render the practices, which could be accompanied with exposure to ionizing radiations, more safe within a firm legal system that is also backed by promulgating suitable executive regulations. Most Arab countries are keen to promulgate their legislations for regulating the work with ionizing radiations and protection against their dangers. Those legislations usually get their genesis and provisions from the international recommendations as well as from the general legal system of the country. The present work consists of four chapters. The first chapter deals with the definition of legislations for regulating the work with ionizing radiations. Chapter two discusses the international trend to promulgate legislations for protection against ionizing radiations. Chapter three includes an analytical comparative study on the legislations that regulates the work with ionizing radiations in the Arab countries. Finally, chapter four deals with the legislations for protection against ionizing radiations in the Arab Republic of Egypt

Generation of polypeptide-templated gold nanoparticles using ionizing radiation.

Science.gov (United States)

Walker, Candace Rae; Pushpavanam, Karthik; Nair, Divya Geetha; Potta, Thrimoorthy; Sutiyoso, Caesario; Kodibagkar, Vikram D; Sapareto, Stephen; Chang, John; Rege, Kaushal

2013-08-13

Ionizing radiation, including γ rays and X-rays, are high-energy electromagnetic radiation with diverse applications in nuclear energy, astrophysics, and medicine. In this work, we describe the use of ionizing radiation and cysteine-containing elastin-like polypeptides (C(n)ELPs, where n = 2 or 12 cysteines in the polypeptide sequence) for the generation of gold nanoparticles. In the presence of C(n)ELPs, ionizing radiation doses higher than 175 Gy resulted in the formation of maroon-colored gold nanoparticle dispersions, with maximal absorbance at 520 nm, from colorless metal salts. Visible color changes were not observed in any of the control systems, indicating that ionizing radiation, gold salt solution, and C(n)ELPs were all required for nanoparticle formation. The hydrodynamic diameters of nanoparticles, determined using dynamic light scattering, were in the range of 80-150 nm, while TEM imaging indicated the formation of gold cores 10-20 nm in diameter. Interestingly, C2ELPs formed 1-2 nm diameter gold nanoparticles in the absence of radiation. Our results describe a facile method of nanoparticle formation in which nanoparticle size can be tailored based on radiation dose and C(n)ELP type. Further improvements in these polypeptide-based systems can lead to colorimetric detection of ionizing radiation in a variety of applications.

Sperm quality and DNA damage in men from Jilin Province, China, who are occupationally exposed to ionizing radiation.

Science.gov (United States)

Zhou, D D; Hao, J L; Guo, K M; Lu, C W; Liu, X D

2016-03-22

Long-term radiation exposure affects human health. Ionizing radiation has long been known to raise the risk of cancer. In addition to high doses of radiation, low-dose ionizing radiation might increase the risk of cardiovascular disease, lens opacity, and some other non-cancerous diseases. Low- and high-dose exposures to ionizing radiation elicit different signaling events at the molecular level, and may involve different response mechanisms. The health risks arising from exposure to low doses of ionizing radiation should be re-evaluated. Health workers exposed to ionizing radiation experience low-dose radiation and have an increased risk of hematological malignancies. Reproductive function is sensitive to changes in the physical environment, including ionizing radiation. However, data is scarce regarding the association between occupational radiation exposure and risk to human fertility. Sperm DNA integrity is a functional parameter of male fertility evaluation. Hence, we aimed to report sperm quality and DNA damage in men from Jilin Province, China, who were occupationally exposed to ionizing radiation. Sperm motility and normal morphology were significantly lower in the exposed compared with the non-exposed men. There was no statistically significant difference in sperm concentration between exposed and non-exposed men. The sperm DNA fragmentation index was significantly higher in the exposed than the non-exposed men. Chronic long-term exposure to low doses of ionizing radiation could affect sperm motility, normal morphology, and the sperm DNA fragmentation index in the Chinese population. Sperm quality and DNA integrity are functional parameters that could be used to evaluate occupational exposure to ionizing radiation.

Induction of inositol 1,4,5 trisphosphate receptor genes by ionizing radiation

International Nuclear Information System (INIS)

Yan, J.

1996-01-01

We used differential display, a method designed to amplify partial cDNA sequences from subsets of mRNAs, to identify mRNAs induced by ionizing radiation in human Epstein Barr Virus (EBV)-transformed lymphoblastoid cells. Increased expression of a cDNA corresponding to the inositol 1,4,5 trisphosphate receptor (InsP 3 R) type 1 was observed after exposure of cells to 3Gy γ-rays. This was confirmed by Northern blot analysis. The increase in mRNA for InsP 3 R type 1 was accompanied by a corresponding increase in the level of InsP 3 R type 1 protein as determined by Western blotting. Exposure of cells from patients with the human genetic disorder ataxia-telangiectasia (A-T), characterized by hypersensitivity to ionizing radiation, failed to change the levels of InsP 3 R type 1 mRNA and, as expected, there was no increase in InsP 3 R type 1 protein in A-T cells in response to radiation exposure. Protein levels for two other InsP 3 Rs, types 2 and 3, were observed to increase in control and A-T cells after exposure to ionizing radiation. The induction of the InsP 3 R type 1, which is primarily located in the endoplasmic reticulum, may play an important role in radiation signal transduction. (Author)

Ionizing radiation detector

Science.gov (United States)

Thacker, Louis H.

1990-01-01

An ionizing radiation detector is provided which is based on the principle of analog electronic integration of radiation sensor currents in the sub-pico to nano ampere range between fixed voltage switching thresholds with automatic voltage reversal each time the appropriate threshold is reached. The thresholds are provided by a first NAND gate Schmitt trigger which is coupled with a second NAND gate Schmitt trigger operating in an alternate switching state from the first gate to turn either a visible or audible indicating device on and off in response to the gate switching rate which is indicative of the level of radiation being sensed. The detector can be configured as a small, personal radiation dosimeter which is simple to operate and responsive over a dynamic range of at least 0.01 to 1000 R/hr.

Autophagic cell death induced by reactive oxygen species is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells.

Science.gov (United States)

Yuan, Guang-Jin; Deng, Jun-Jian; Cao, De-Dong; Shi, Lei; Chen, Xin; Lei, Jin-Ju; Xu, Xi-Ming

2017-08-14

To investigate whether autophagic cell death is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells, and to explore the underlying mechanism. Human hepatocellular carcinoma cells were treated with hyperthermia and ionizing radiation. MTT and clonogenic assays were performed to determine cell survival. Cell autophagy was detected using acridine orange staining and flow cytometric analysis, and the expression of autophagy-associated proteins, LC3 and p62, was determined by Western blot analysis. Intracellular reactive oxygen species (ROS) were quantified using the fluorescent probe DCFH-DA. Treatment with hyperthermia and ionizing radiation significantly decreased cell viability and surviving fraction as compared with hyperthermia or ionizing radiation alone. Cell autophagy was significantly increased after ionizing radiation combined with hyperthermia treatment, as evidenced by increased formation of acidic vesicular organelles, increased expression of LC3II and decreased expression of p62. Intracellular ROS were also increased after combined treatment with hyperthermia and ionizing radiation. Pretreatment with N-acetylcysteine, an ROS scavenger, markedly inhibited the cytotoxicity and cell autophagy induced by hyperthermia and ionizing radiation. Autophagic cell death is involved in hyperthermic sensitization of cancer cells to ionizing radiation, and its induction may be due to the increased intracellular ROS.

Biological effects of ionizing radiation

International Nuclear Information System (INIS)

Heribanova, A.

1995-01-01

The basic principles and pathways of effects of ionizing radiation on living organisms and cells are outlined. The following topics are covered: effects of radiation on living matter (direct effects, radical or indirect effects, dual radiation action, and molecular biological theories); effects of radiation on cells and tissues (cell depletion, changes in the cytogenetic information, reparation mechanisms), dose-response relationship (deterministic effects, stochastic effects), and the effects of radiation on man (acute radiation sickness, acute local changes, fetus injuries, non-tumorous late injuries, malignant tumors, genetic changes). (P.A.). 3 tabs., 2 figs., 5 refs

Responses of populations of small mammals to ionizing radiation

International Nuclear Information System (INIS)

Kitchings, J.T.

1978-01-01

Studies on the responses of small mammals to ionizing radiation have, over the past 30 years, documented numerous effects on direct mortality, reproduction, the hemopoietic systems, and radionuclide metabolism. Three general findings have resulted from past efforts: (1) ionizing radiation is a factor in environmental stress, (2) the response of wild small mammals to ionizing radiation is a mosaic of varying radiosensitivities interacting with environmental variables, and (3) one of the most sensitive organismal processes to radiation is reproduction. While an excellent understanding of the biological effects resulting from high or intermediate-level radiation exposures has been developed, this is not the case for effects of low-level doses

The dosimetry of ionizing radiation

CERN Document Server

1990-01-01

A continuation of the treatise The Dosimetry of Ionizing Radiation, Volume III builds upon the foundations of Volumes I and II and the tradition of the preceeding treatise Radiation Dosimetry. Volume III contains three comprehensive chapters on the applications of radiation dosimetry in particular research and medical settings, a chapter on unique and useful detectors, and two chapters on Monte Carlo techniques and their applications.

Effects of occupational exposure to ionizing radiation on reproductive and child health

International Nuclear Information System (INIS)

Bienefeld, M.K.; McLaughlin, J.R.

1998-01-01

The evidence regarding the effects of occupational exposure to low levels of ionizing radiation on reproductive health is limited. However, exposure to high doses of ionizing radiation is associated with increased risk of adverse reproductive outcomes. The resulting uncertainty about the effects of occupational exposures has caused concern among some workers, therefore, we have designed a study to examine this question among Canadian medical radiation technologists. A short mailed questionnaire will be sent to all CAMRT members to obtain information about reproductive history, and a sample of respondents will receive a second questionnaire requesting information about other important exposures. Occupational dose records will be retrieved from the National Dose Registry. Using this information, relative risks for each outcome will be calculated for different radiation dose levels. This article provides a brief review of the literature on ionizing radiation exposure and reproductive outcomes, and an outline of the proposed study

Clinical practitioners' knowledge of ionizing radiation doses in ...

African Journals Online (AJOL)

Questions on radiosensitivity of different organs, imaging modalities that use ionizing radiation and considerations for the choice of ionizing radiation (IR) based examinations were included. Participants were also asked for their preferred methods of filling any knowledge gap on IR issues. Responses were presented in ...

Detection and measurement of ionizing radiation

International Nuclear Information System (INIS)

Anon.

1990-01-01

All detection or measurement of radiation rests in the possibility of recognizing the interactions of radiation with matter. When radiation passes through any kind of material medium, all or a portion of its energy is transferred to this medium. This transferred energy produces an effect in the medium. In principle, the detection of radiation is based on the appearance and the observation of this effect. In theory, all of the effects produced by radiation may be used in detecting it: in practice, the effects most commonly employed are: (1) ionization of gases (gas detectors), or of some chemical substance which is transformed by radiation (photographic or chemical dosimeters); (2) excitations in scintillators or semiconductors (scintillation counters, semiconductor counters); (3) creation of structural defects through the passage of radiation (transparent thermoluminescent and radioluminescent detectors); and (4) raising of the temperature (calorimeters). This study evaluates in detail, instruments based on the ionization of gases and the production of luminescence. In addition, the authors summarize instruments which depend on other forms of interaction, used in radiation medicine and hygiene (radiology, nuclear medicine)

Ionizing radiation increases primary cilia incidence and induces multiciliation in C2C12 myoblasts

Czech Academy of Sciences Publication Activity Database

Filipová, A.; Diaz-Garcia, D.; Bezrouk, A.; Čížková, D.; Havelek, R.; Vávrová, J.; Dayanithi, Govindan; Řezáčová, M.

2015-01-01

Roč. 39, č. 8 (2015), s. 943-953 ISSN 1065-6995 Institutional support: RVO:68378041 Keywords : cell line * ionizing radiation * multiple cilia * myoblast * primary cilium * serum starvation stress Subject RIV: FP - Other Medical Disciplines Impact factor: 1.663, year: 2015

Biological effects of low doses of ionizing radiation

International Nuclear Information System (INIS)

Gonzalez, A.J.

1994-01-01

Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

Proceedings of the 15. Berzelius symposium on somatic and genetic effects of ionizing radiation

International Nuclear Information System (INIS)

Stigbrand, T.

1989-01-01

The symposium begins with a brush up on the physics of ionizing radiation and a background to the natural and man-made source of radiation to which we are exposed. The next section deals with the origin and nature of radiation-induced damage to DNA. The somatic effects of ionizing radiation span from DNA lesions to various effects on cell structure and cell function and effects on whole organs. The somatic effects are immediate as well as long-term, with mental impairment and an increased risk for carcinogenesis as consequences of main concern. The genetic effects of ionizing radiation can result in: infertility, spontaneous abortions, genetic diseases and malformations and increased risk for cancer. This leads over to the problems of risk estimation. Risk estimation which is mainly based on experimental data using animal models, human cell lines and epidemiological studies of exposed and unexposed populations

The characteristics of peripheral blood leukocytes in persons working with ionizing radiation sources

International Nuclear Information System (INIS)

Zykova, I.A.; Sokolova, N.B.; Yas'kova, V.Z.

1984-01-01

Functional and qualitative changes of peripheral blood cellular composition were studied in persons working over a long period of time with ionizing radiation sources under the action of various factors of production upon an organism. Appression of a function and increase of T-lymphocyte chromosome damages were revealed against the background of a decrease both of enzymatic activity level and leukocyte number in persons operating for a long time (more than 10 years) with ionizing radiation sources. Discovered changes occurred under the action upon a human being not only of small doses of ionizing radiation but a whole complex of industrial factors which may initiate changes of adapted character

Adaptation of the black yeast Wangiella dermatitidis to ionizing radiation: molecular and cellular mechanisms.

Directory of Open Access Journals (Sweden)

Kelly L Robertson

Full Text Available Observations of enhanced growth of melanized fungi under low-dose ionizing radiation in the laboratory and in the damaged Chernobyl nuclear reactor suggest they have adapted the ability to survive or even benefit from exposure to ionizing radiation. However, the cellular and molecular mechanism of fungal responses to such radiation remains poorly understood. Using the black yeast Wangiella dermatitidis as a model, we confirmed that ionizing radiation enhanced cell growth by increasing cell division and cell size. Using RNA-seq technology, we compared the transcriptomic profiles of the wild type and the melanin-deficient wdpks1 mutant under irradiation and non-irradiation conditions. It was found that more than 3000 genes were differentially expressed when these two strains were constantly exposed to a low dose of ionizing radiation and that half were regulated at least two fold in either direction. Functional analysis indicated that many genes for amino acid and carbohydrate metabolism and cell cycle progression were down-regulated and that a number of antioxidant genes and genes affecting membrane fluidity were up-regulated in both irradiated strains. However, the expression of ribosomal biogenesis genes was significantly up-regulated in the irradiated wild-type strain but not in the irradiated wdpks1 mutant, implying that melanin might help to contribute radiation energy for protein translation. Furthermore, we demonstrated that long-term exposure to low doses of radiation significantly increased survivability of both the wild-type and the wdpks1 mutant, which was correlated with reduced levels of reactive oxygen species (ROS, increased production of carotenoid and induced expression of genes encoding translesion DNA synthesis. Our results represent the first functional genomic study of how melanized fungal cells respond to low dose ionizing radiation and provide clues for the identification of biological processes, molecular pathways and

Application of Ionizing Radiation on the Cork Wastewater Treatment

Energy Technology Data Exchange (ETDEWEB)

Melo, R.; Madureira, J.; Verde, S. Cabo; Nunes, I.; Santos, P. M.P.; Silva, T.; Leal, J. P.; Botelho, M. L. [Instituto Tecnológico e Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa, Sacavém (Portugal)

2012-07-01

In the framework of the CRP on “Radiation treatment of wastewater for reuse with particular focus on wastewaters containing organic pollutants” Portuguese team is been developed studies on the implementation of ionizing radiation technology as a complementary treatment for industrial effluents and increase the added value of these wastewaters. Based on these assumptions, preliminary studies of the gamma radiation effects on the antioxidant compounds present in cork cooking water were carried out. Radiation studies were performed by using radiation between 20 and 50 kGy at 0.4 kGy/h and 2.4 kGy/h. The radiation effects on organic matter content were evaluated by Chemical Oxygen Demand (COD). The antioxidant activity was measured by Ferric Reducing Power (FRAP) assay. The total phenolic content was studied by Folin-Ciocalteau method. Results point out that gamma radiation increases both the amount of phenolic compounds and antioxidant capacity of cork cooking water. By the other hand, the radiolytic degradation by ionizing radiation of gallic acid and esculetin as models for recalcitrants were studied. The objective of this study was to find out if radiolytic degradation, followed by microbial degradation could increase the treatment efficiency. A natural cork wastewater bacterium was selected from the irradiated wastewater at 9 kGy. The applied methodology was based on the evaluation of growth kinetics of the selected bacteria by turbidimetry and colony forming units, in minimal salt medium with non-irradiated and irradiated phenolic as substrate. The overall obtained results highlights the potential of this technology for increase the add value of cork waters and raised some issues to explain by new methodological setup on biodegradation studies. (author)

Application of Ionizing Radiation on the Cork Wastewater Treatment

International Nuclear Information System (INIS)

Melo, R.; Madureira, J.; Verde, S. Cabo; Nunes, I.; Santos, P.M.P.; Silva, T.; Leal, J.P.; Botelho, M.L.

2012-01-01

In the framework of the CRP on “Radiation treatment of wastewater for reuse with particular focus on wastewaters containing organic pollutants” Portuguese team is been developed studies on the implementation of ionizing radiation technology as a complementary treatment for industrial effluents and increase the added value of these wastewaters. Based on these assumptions, preliminary studies of the gamma radiation effects on the antioxidant compounds present in cork cooking water were carried out. Radiation studies were performed by using radiation between 20 and 50 kGy at 0.4 kGy/h and 2.4 kGy/h. The radiation effects on organic matter content were evaluated by Chemical Oxygen Demand (COD). The antioxidant activity was measured by Ferric Reducing Power (FRAP) assay. The total phenolic content was studied by Folin-Ciocalteau method. Results point out that gamma radiation increases both the amount of phenolic compounds and antioxidant capacity of cork cooking water. By the other hand, the radiolytic degradation by ionizing radiation of gallic acid and esculetin as models for recalcitrants were studied. The objective of this study was to find out if radiolytic degradation, followed by microbial degradation could increase the treatment efficiency. A natural cork wastewater bacterium was selected from the irradiated wastewater at 9 kGy. The applied methodology was based on the evaluation of growth kinetics of the selected bacteria by turbidimetry and colony forming units, in minimal salt medium with non-irradiated and irradiated phenolic as substrate. The overall obtained results highlights the potential of this technology for increase the add value of cork waters and raised some issues to explain by new methodological setup on biodegradation studies. (author)

Influence of ionizing radiation on human body

Directory of Open Access Journals (Sweden)

Zygmunt Zdrojewicz

2016-06-01

Full Text Available This article describes positive and negative aspects of ionizing radiation and its effects on human body. Being a part of various medical procedures in medicine, ionising radiation has become an important aspect for both medical practitioners and patients. Commonly used in treatment, diagnostics and interventional radiology, its medical usage follows numerous rules, designed to reduce excessive exposure to ionizing radiation. Its widespread use makes it extremely important to research and confirm effects of various doses of radiation on patients of all ages. Two scientific theories, explaining radiation effects on human organism, stand in contrast: commonly accepted LNT-hypothesis and yet to be proven hormesis theory. Despite the fact that the current radiation protection standards are based on the linear theory (LNT-hypothesis, the hormesis theory arouses more and more interest, and numerous attempts are made to prove its validity. Further research expanding the knowledge on radiation hormesis can change the face of the future. Perhaps such researches will open up new possibilities for the use of ionizing radiation, as well as enable the calculation of the optimal and personalised radiation dose for each patient, allowing us to find a new “golden mean”. The authors therefore are careful and believe that these methods have a large future, primarily patient’s good should however be kept in mind.

Effect of ionizing radiations on connective tissue

International Nuclear Information System (INIS)

Altman, K.I.; Gerber, G.B.

1980-01-01

The effects of ionizing radiations on connective tissue in lung, heart, vasculature, kidney, skin, and skeletal tissues are reviewed. Special emphasis is given to the effect of ionizing radiations on vasculo-connective tissue and fibrotic changes following radiation-induced injury to organs and tissues. In order to put the subject matter in proper prospective, the general biochemistry, physiology, and pathology of connective tissue is reviewed briefly together with the participation of connective tissue in disease. The review closes with an assessment of future problems and an enumeration and discussion of important, as yet unanswered questions

Ionizing radiation environment for the TOMS mission

Science.gov (United States)

Lauriente, M.; Maloy, J. O.; Vampola, A. L.

1992-01-01

The Total Ozone Mapping Spectrometer (TOMS) will fly on several different spacecraft, each having an orbit which is approximately polar and 800-980 km in altitude. A description is given of the computer-based tools used for characterizing the spacecraft interactions with the ionizing radiation environment in orbit and the susceptibility requirements for ionizing radiation compatibility. The peak flux from the model was used to derive the expected radiation-induced noise in the South Atlantic Anomaly for the new TOMS instruments intended to fly on Advanced Earth Observatory System and Earth Probe.

Response of GaAs charge storage devices to transient ionizing radiation

Science.gov (United States)

Hetherington, D. L.; Klem, J. F.; Hughes, R. C.; Weaver, H. T.

Charge storage devices in which non-equilibrium depletion regions represent stored charge are sensitive to ionizing radiation. This results since the radiation generates electron-hole pairs that neutralize excess ionized dopant charge. Silicon structures, such as dynamic RAM or CCD cells are particularly sensitive to radiation since carrier diffusion lengths in this material are often much longer than the depletion width, allowing collection of significant quantities of charge from quasi-neutral sections of the device. For GaAs the situation is somewhat different in that minority carrier diffusion lengths are shorter than in silicon, and although mobilities are higher, we expect a reduction of radiation sensitivity as suggested by observations of reduced quantum efficiency in GaAs solar cells. Dynamic memory cells in GaAs have potential increased retention times. In this paper, we report the response of a novel GaAs dynamic memory element to transient ionizing radiation. The charge readout technique is nondestructive over a reasonable applied voltage range and is more sensitive to stored charge than a simple capacitor.

Effects of ionizing radiation on plant tissue cultures

International Nuclear Information System (INIS)

Hell, K.G.

1978-01-01

A short review is done of the biological effects of ionizing radiations on plant tissues kept in culture, from the work of Gladys King, in 1949, with X-ray irradiated tobacco. The role of plant hormones is discussed in the processes of growth inhibition and growth restoration of irradiated tissues, as well as morphogenesis. Radioresistance of cells kept in culture and the use of ionizing radiations as mutagens are also commented. Some aspects of the biological effects of ionizing radiations that need to be investigated are discussed, and the problem of genome instability of plant tissues kept in culture is pointed out. (M.A.) [pt

Biological effects of ionizing radiation

International Nuclear Information System (INIS)

Anon.

1991-01-01

Experiments with small animals, tissue cultures, and inanimate materials help with understanding the effects of ionizing radiation that occur at the molecular level and cause the gross effects observed in man. Topics covered in this chapter include the following: Radiolysis of Water; Radiolysis of Organic Compounds; Radiolysis in Cells; Radiation Exposure and Dose Units; Dose Response Curves; Radiation Effects in Animals; Factors Affecting Health Risks. 8 refs., 3 figs., 5 tabs

Protection during work with ionizing radiation sources; Ochrana pri praci se zdroji ionizujiciho zareni

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

The publication has been set up as a textbook for training courses dealing with health protection during work with ionizing radiation, designed for supervisory staff and persons directly responsible for activities which involve the handling of ionizing radiation sources. The book consists of a preface and the following chapters: (1) Fundamentals of ionizing radiation physics; (2) Quantities and units used in ionizing radiation protection; (3) Principles of ionizing radiation dosimetry; (4) Biological effects of ionizing radiation; (5) An overview of sources of public irradiation; (6) Principles and methods of health protection against ionizing radiation; (7) Examples of technical applications of sources of ionizing radiation; (8) Personnel and working environment monitoring; (9) Documentation maintained at sites with ionizing radiation sources; (10) Methods of personnel protection against external irradiation and internal radionuclide contamination; (11) Radiation incidents and accidents; (12) Health care of personnel exposed to the ionizing radiation risk; (12) Additional radiation protection requirements in handling radioactive substances other than sealed sources; (13) Measurement and metrology. (P.A.).

Regulation of tumor necrosis factor gene expression by ionizing radiation in human myeloid leukemia cells and peripheral blood monocytes

International Nuclear Information System (INIS)

Sherman, M.L.; Datta, R.; Hallahan, D.E.; Weichselbaum, R.R.; Kufe, D.W.

1991-01-01

Previous studies have demonstrated that ionizing radiation induces the expression of certain cytokines, such as TNF alpha/cachectin. However, there is presently no available information regarding the molecular mechanisms responsible for the regulation of cytokine gene expression by ionizing radiation. In this report, we describe the regulation of the TNF gene by ionizing radiation in human myeloid leukemia cells. The increase in TNF transcripts by x rays was both time- and dose-dependent as determined by Northern blot analysis. Similar findings were obtained in human peripheral blood monocytes. Transcriptional run-on analyses have demonstrated that ionizing radiation stimulates the rate of TNF gene transcription. Furthermore, induction of TNF mRNA was increased in the absence of protein synthesis. In contrast, ionizing radiation had little effect on the half-life of TNF transcripts. These findings indicate that the increase in TNF mRNA observed after irradiation is regulated by transcriptional mechanisms and suggest that production of this cytokine by myeloid cells may play a role in the pathophysiologic effects of ionizing radiation

Chromosomal aberrations in subjects exposed to ionizing radiation

International Nuclear Information System (INIS)

Jovicic, D.; Milacic, S.; Kovacevic, R.; Tanaskovic, I.

2006-01-01

Occupational exposure is particularly delicate because of chronic exposure to low doses of ionizing radiation and its cumulative effect, where it is important to consider the biological response of body to given conditions of exposure. The objective of this study was the observation of the recovery of the DNA damages in subjects working in the radiation area in two different intervals.Group I, consisting of 30 subjects, was exposed to ionizing radiation and unstable chromosomal aberrations were identified. Group II included the same, re-examined subjects (30) 9 months later. It was verified that 5 (16.67%) subjects still had unstable chromosomal aberrations, although they had been excluded from radiation area Controls groups (C) consisted of 64 subjects that were not exposed to mutagenic agents.The comparison of the control group with the two studied groups revealed the reduction of the unstable aberrations (p<0.05). The total effective doses, which increased with the years spent in radiation area, reflected the yield of chromosomal aberrations. The presence of chromosomal aberrations in some subjects, after the exclusion from the ionising radiation exposure, suggests that the time needed for the recovery of the DNA damages is different, which indicates the individual differences in radiosensitivity as well as different of the reparatory cellular response. (author)

Solar irradiance changes and photobiological effects at earth's surface following astrophysical ionizing radiation events.

Science.gov (United States)

Thomas, Brian C; Neale, Patrick J; Snyder, Brock R

2015-03-01

Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in surface-level solar ultraviolet radiation. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In this work, we employed the Tropospheric Ultraviolet and Visible (TUV) radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light) for clear-sky conditions and fixed aerosol parameter values. We also considered a wide range of biological effects on organisms ranging from humans to phytoplankton. We found that past work overestimated UVB irradiance but that relative estimates for increase in exposure to DNA-damaging radiation are still similar to our improved calculations. We also found that the intensity of biologically damaging radiation varies widely with organism and specific impact considered; these results have implications for biosphere-level damage following astrophysical ionizing radiation events. When considering changes in surface-level visible light irradiance, we found that, contrary to previous assumptions, a decrease in irradiance is only present for a short time in very limited geographical areas; instead we found a net increase for most of the modeled time-space region. This result has implications for proposed climate changes associated with ionizing radiation events.

Risk of occupational exposure to ionizing radiation among medical workers in Canada

International Nuclear Information System (INIS)

Zielinski, Jan M.; Band, Pierre R.; Garner, Michael J.; Krewski, Daniel; Shilnikova, Natalia S.; Jiang, Huixia; Ashmore, Patrick J.; Sont, Willem N.; Fair, Martha E.; Letourneau, Ernest G.; Semenciw, Robert

2010-01-01

Medical workers are exposed to chronic low dose ionizing radiation from a variety of sources. Potential cancer risks associated with ionizing radiation exposures have been derived from cohorts experiencing acute high intensity exposure, most notably the Japanese atomic bomb survivors. Since such extrapolations are subject to uncertainty, direct information on the risk associated with chronic low dose occupational exposure to ionizing radiation is needed. We examined possible associations with cancer incidence and mortality in a cohort of medical workers ascertained by the National Dose Registry of Canada (NDR). Data from the NDR were used to assess the exposure to ionizing radiation incurred between 1951 to 1987 inclusive in a cohort of 67,562 subjects classified as medical workers. Standardized mortality (SMRs) and incidence (SIRs) ratios were ascertained by linking NDR data with the data maintained by Statistics Canada in the Canadian Mortality and in the Canadian Cancer Incidence Databases respectively. Dosimetry information was obtained from the National Dosimetry Services of the Radiation Protection Bureau of Health Canada. There were 23,580 male and 43,982 female medical workers in the cohort. During the follow-up period, 1309 incident cases of cancer (509 in males, 800 in females) and 1,325 deaths (823 in males, 502 in females) were observed. Mortality from cancer and non-cancer causes was generally below expected compared to the Canadian population. Thyroid cancer incidence was significantly elevated in both males and females, with a combined SIR of 1.74 and 90% confidence interval (90% CI: 1.40-2.10). Our result of an increased risk of thyroid cancer among medical workers occupationally exposed to ionizing radiation confirms previous reports. Over the last 50 years, radiation protection measures have been effective in reducing occupational exposures of medical workers to ionizing radiation to current very low levels. (author)

Basic ionizing radiation symbol

International Nuclear Information System (INIS)

1987-01-01

A description is given of the standard symbol for ionizing radiation and of the conditions under which it should not be used. The Arabic equivalent of some English technical terms in this subject is given in one page. 1 ref., 1 fig

Role of ionizing radiation in chemical evolution studies

International Nuclear Information System (INIS)

Albarran, G.; Negron-Mendoza, A.; Trevino, C.; Torres, J.L.

1988-01-01

The purpose of this paper is to emphasize the role of ionizing radiation in radiation-induced reactions in prebiotic chemistry. The use of ionizing radiation as an energy source is based on its unique qualities, its specific manner of energy deposition and its abundance in the Earth's crust. As an example of radiation-induced reactions, the radiolysis of malonic acid was investigated. Malonic acid is converted into other carboxylic acids. The results obtained have been correlated with the ready formation of this compound in prebiotic experiments. (author)

Ionizing radiations: effects and sources

International Nuclear Information System (INIS)

Vignes, S.; Nenot, J.C.

1978-01-01

Having first mentioned the effects of ionizing radiations in cancerogenisis, pre-natal, and genetic fields, the authors present the different sources of radiations and estimate their respective contributions to the total irradiation dose. Their paper makes reference to the main elements of a report issued by the United Nations Scientific Committee in 1977 [fr

Chemical protection against ionizing radiation

International Nuclear Information System (INIS)

Livesey, J.C.; Reed, D.J.

1987-01-01

Over 40 years have passed since the research of the Manhattan Project suggested the possibility of chemical protection against ionizing radiation. During that time, much has been learned about the nature of radiation-induced injury and the factors governing the expression of that injury. Thousands of compounds have been tested for radioprotective efficacy, and numerous theories have been proposed to account for these actions. The literature on chemical radioprotection is large. In this article, the authors consider several of the mechanisms by which chemicals may protect against radiation injury. They have chosen to accent this view of radioprotector research as opposed to that research geared toward developing specific molecules as protective agents because they feel that such an approach is more beneficial in stimulating research of general applicability. This paper describes the matrix of biological factors upon which an exogenous radioprotector is superimposed, and examines evidence for and against various mechanisms by which these agents may protect biological systems against ionizing radiation. It concludes with a brief outlook for research in chemical radioprotection

Epigenetic effects of ionizing radiation

International Nuclear Information System (INIS)

EI-Naggar, A.M.

2007-01-01

Data generated during the last three decades provide evidence of Epigenetic Effects that ave-induced by ionizing radiation, particularly those of high LET values, and low level dose exposures. Epigenesist is defined as the stepwise process by which genetic information, as modified by environmental influences, is translated into the substance and behavior of cells, tissues, organism.The epigenetic effects cited in the literature are essentially classified into fine types depending on the type and nature of the effect induced.The most accepted postulation, for the occurrence of these epigenetic effects, is a radiation induced bio electric disturbances in the environment of the non-irradiated cellular volume. This will trigger signals that will induce effects in the unirradiated cells.The epigenetic effects referenced in the literature up to date are five types; namely, Genomic Instability, Bystander. Effects, Clastogenic Plasma Factors,, Abscopal Effects, and Tran generational Effects.The demonstration of Epigenetic Effects associated with exposure to ionizing radiation indicates the need to re- examine the concept of radiation dose and target size. Also an improved understanding of qualifiring and quantifying radiation risk estimates may be attained. Also, a more logical means to understand the underlying mechanisms of radiation induced carcinogenic transformation of cells

The mechanism for the primary biological effects of ionizing radiation

International Nuclear Information System (INIS)

Byakov, Vsevolod M; Stepanov, Sergei V

2006-01-01

The primary biological response of living organisms to the passage of fast charged particles is traditionally believed to be dominated by the chemical reactions of the radical products from the radiolysis of cellular water (OH, H, e aq - , O 2 - , H 2 O 2 ) and by the bioradicals that they produce (and which can also result from the direct electronic activation of biomolecules). This understanding has provided insight into how ionizing radiations affect biological systems and, most importantly, what radioprotection and radiosensibilizing effects are produced by chemical compounds introduced into an organism. However, a number of key radiobiological facts remain unexplained by the current theory, stimulating a search for other biologically active factors that may be triggered by radiation. This review examines a fact that is usually ignored in discussing the biological impact of ionizing radiation: the local increase in acidity in the water solution along the track of a charged particle. The acidity in the track is very different from its value for cellular water in a living organism. Biological processes are well-known to be highly sensitive to changes in the environmental acidity. It seems that the biological impact of ionizing radiations is dominated not by the water radiolysis products (mostly radicals) listed above but particles of a different nature, hydroxonium ions H 3 O + , where the term hydroxonium refer to protonated water molecules. This modification of the mechanism of primary radiobiological effects is in good agreement with experimental data. In particular, the extremal dependence of the relative biological efficiency (RBE) of radiations on their ionizing energy losses is accounted for in quantitative terms, as is the increase in the RBE in the relativistic energy range. (reviews of topical problems)

Method and apparatus to monitor a beam of ionizing radiation

Science.gov (United States)

Blackburn, Brandon W.; Chichester, David L.; Watson, Scott M.; Johnson, James T.; Kinlaw, Mathew T.

2015-06-02

Methods and apparatus to capture images of fluorescence generated by ionizing radiation and determine a position of a beam of ionizing radiation generating the fluorescence from the captured images. In one embodiment, the fluorescence is the result of ionization and recombination of nitrogen in air.

Biological effects of the ionizing radiation. Press breakfast

International Nuclear Information System (INIS)

Flury-Herard, A.; Boiteux, S.; Dutrillaux, B.; Toledano, M.

2000-06-01

This document brings together the subjects discussed during the Press breakfast of 29 june 2000 on the biological effects of the ionizing radiations, with scientists of the CEA and the CNRS. It presents the research programs and provides inquiries on the NDA operating to introduce the NDA damages by ionizing radiations, the possible repairs and the repair efficiency facing the carcinogenesis. Those researches allow the scientists to define laws on radiation protection. (A.L.B.)

Applications of ionizing radiations

International Nuclear Information System (INIS)

2014-01-01

Developments in standard applications and brand new nuclear technologies, with high impact on the future of the agriculture, medicine, industry and the environmental preservation. The Radiation Technology Center (CTR) mission is to apply the radiation and radioisotope technologies in Industry, Health, Agriculture, and Environmental Protection, expanding the scientific knowledge, improving human power resources, transferring technology, generating products and offering services for the Brazilian society. The CTR main R and D activities are in consonance with the IPEN Director Plan (2011-2013) and the Applications of Ionizing Radiation Program, with four subprograms: Irradiation of Food and Agricultural Products; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for the Applications of Nuclear Techniques

Applications of ionizing radiations

Energy Technology Data Exchange (ETDEWEB)

NONE

2014-07-01

Developments in standard applications and brand new nuclear technologies, with high impact on the future of the agriculture, medicine, industry and the environmental preservation. The Radiation Technology Center (CTR) mission is to apply the radiation and radioisotope technologies in Industry, Health, Agriculture, and Environmental Protection, expanding the scientific knowledge, improving human power resources, transferring technology, generating products and offering services for the Brazilian society. The CTR main R and D activities are in consonance with the IPEN Director Plan (2011-2013) and the Applications of Ionizing Radiation Program, with four subprograms: Irradiation of Food and Agricultural Products; Radiation and Radioisotopes Applications in Industry and Environment; Radioactive Sources and Radiation Applications in Human Health; and Radioactive Facilities and Equipment for the Applications of Nuclear Techniques.

38 CFR 3.311 - Claims based on exposure to ionizing radiation.

Science.gov (United States)

2010-07-01

... to ionizing radiation. 3.311 Section 3.311 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... Evaluations; Service Connection § 3.311 Claims based on exposure to ionizing radiation. (a) Determinations of... to ionizing radiation in service, an assessment will be made as to the size and nature of the...

Specification for symbol for ionizing radiation

International Nuclear Information System (INIS)

1974-01-01

This Malaysia Standard specification specifies a symbol recommended for use only to signify the actual or potential presence of ionizing radiation (#betta#, α, #betta# only) and to identify objects, devices, materials or combinations of materials which emit such radiation. (author)

Does nitrate deposition following astrophysical ionizing radiation events pose an additional threat to amphibians?

OpenAIRE

Thomas, Brian C.; Honeyman, Michelle D.

2008-01-01

It is known that amphibians are especially susceptible to the combination of heightened UVB radiation and increased nitrate concentrations. Various astrophysical events have been suggested as sources of ionizing radiation that could pose a threat to life on Earth, through destruction of the ozone layer and subsequent increase in UVB, followed by deposition of nitrate. In this study, we investigate whether the nitrate deposition following an ionizing event is sufficiently large to cause an add...

Device for the integral measurement of ionizing radiations

International Nuclear Information System (INIS)

Micheron, Francois.

1980-01-01

This invention relates to devices for the integral determination of ionizing radiations, particularly to the construction of a portable dosemeter. Portable measuring instruments have been suggested in the past, particularly dosemeters in which the discharge of a capacitor under the action of ionizing radiations is measured. Since the charge of a capacitor is not stable owing to dielectric imperfections, these measuring instruments have to be recalibrated at frequent intervals. To overcome this drawback, the invention suggests using the discharge of an electret, electrically charged to a pre-set initial value, under the action of ionizing radiations, as the transducer means of a dosemeter used in conjunction with display or warning systems [fr

Modulation of the Inflammatory Response by Ionizing Radiation and the Possible Role of Curcumin

International Nuclear Information System (INIS)

Hegazy, M.El.A.

2009-01-01

The increasing use of radiation and the recent incidents of massive radiation exposure give an importance to study possible radiation hazards. Radiation-induced cell changes may result in death of the organism, death of the cells, modulation of physiological activity, or cancers that have no features distinguishing them from those induced by other types of cell injury (Valko et al., 2004). Electromagnetic radiation is divided into non-ionizing and ionizing radiation according to the energy required to eject electrons from molecules (Bessonov, 2006). Ionizing radiation, which may exhibit the properties of both waves and particles, has sufficient energy to produce ionization in matter. The ionizing radiation that exhibits corpuscular properties include alpha and beta particles, while those that behave more like waves of energy include x-rays and gamma-rays (γ-rays) (Bessonov, 2006). Radiation exposure comes from many sources and may be directly or indirectly ionizing. Directly ionizing radiation carries an electric charge that directly interacts, by electrostatic attraction or repulsion, with atoms in the tissue or the exposed medium. On the other hand, indirectly ionizing radiation is not electrically charged but results in production of charged particles by which its energy is absorbed (Metting et al., 1988). One of the characteristics of charged particles produced directly or indirectly is the linear energy transfer (LET), the energy loss per unit of distance traveled, usually expressed in kilo-electron volts (keV) per micrometer (μm). The LET, depending on the velocity and charge of the particles, may vary from about 0.2 to more than 1000 keV/μm (Table (1)). Radiation interacts with matter by direct and indirect processes to form ion pairs, some of which may be free radicals. These ion pairs rapidly interact with themselves and other surrounding molecules to produce free radicals. Both the indirect and direct activities of ionizing radiation lead to molecular

Use of ionizing radiation in waste water treatment

International Nuclear Information System (INIS)

Cech, R.

1976-01-01

A survey is presented of methods and possibilities of applying ionizing radiation in industrial waste water treatment. The most frequently used radiation sources include the 60 Co and 137 Cs isotopes and the 90 Sr- 90 Y combined source. The results are reported and the methods used are described of waste water treatment by sedimenting impurities and decomposing organic and inorganic compounds by ionizing radiation. It was found that waste water irradiation accelerated sedimentation and decomposition processes. The doses used varied between 50 and 500 krads. Ionizing radiation may also be used in waste water disinfection in which the effects are used of radiation on microorganisms and of the synthesis of ozone which does not smell like normally used chlorine. The described methods are still controversial from the economic point of view but the cost of waste water treatment by irradiation will significantly be reduced by the use of spent fuel elements. (J.B.)

Interaction of ionizing radiation with matter

International Nuclear Information System (INIS)

Calisto, Washington

1994-01-01

Definition of ionizing radiation,interaction of electrons with matter,physical model of collision,elastic and inelastic collisions,range of electron in matter,interaction of photon with matter.Photoelectric effect , Compton effect,pair production,consideration of interaction of various radiations with soft tissue

Ionizing radiation sensitivity of DNA polymerase lambda-deficient cells.

NARCIS (Netherlands)

Vermeulen, C.; Bertocci, B.; Begg, A.C.; Vens, C.

2007-01-01

Ionizing radiation induces a diverse spectrum of DNA lesions, including strand breaks and oxidized bases. In mammalian cells, ionizing radiation-induced lesions are targets of non-homologous end joining, homologous recombination, and base excision repair. In vitro assays show a potential involvement

Space Flight Ionizing Radiation Environments

Science.gov (United States)

Koontz, Steve

2017-01-01

The space-flight ionizing radiation (IR) environment is dominated by very high-kinetic energy-charged particles with relatively smaller contributions from X-rays and gamma rays. The Earth's surface IR environment is not dominated by the natural radioisotope decay processes. Dr. Steven Koontz's lecture will provide a solid foundation in the basic engineering physics of space radiation environments, beginning with the space radiation environment on the International Space Station and moving outward through the Van Allen belts to cislunar space. The benefits and limitations of radiation shielding materials will also be summarized.

High-throughput identification of ionizing radiation-sensitive plant genes and development of radiation indicator plant and radiation sensing Genechip

International Nuclear Information System (INIS)

Kim, Dong Sub; Kim, Jinbaek; Ha, Bokeun; Kim, Sang Hoon; Kim, Sunhee

2013-05-01

Physiological analysis of monocot model plant (rice) in response to ionizing radiation (cosmic-ray, gamma-ray, Ion beam). - Identification of antioxidant characters through cytochemical analysis. - Comparison of antioxidant activities in response to ionizing irradiation. - Evaluation of anthocyanin quantity in response to ionizing irradiation. Ionization energy response gene family analysis via bioinformatic validation. - Expression analysis of monocot and dicot gene families. - In silico and bioinformatic approach to elucidate gene function. Characterization and functional analysis of genes specifically expressed in response to ionizing irradiation (cosmic-ray, gamma-ray, Ion beam). - High throughput trancriptomic analysis of plants under ionizing radiation using microarray. - Promotor and cis-element analysis of genes specifically expressed in response to ionizing radiation. - Validation and function analysis of candidate genes. - Elucidation of plant mechanism of sensing and response to ionization energy. Development of bioindicator plants detecting ionization energy. - Cloning and identification of 'Radio marker genes (RMG)'. - Development of Over-expression (O/E) or Knock-out (K/O) plant using RMG. Development of Genechip as an ionization energy detector. - Expression profiling analysis of genes specifically expression in response to ionization energy. - Prepare high-conserved gene specific oligomer. - Development of ionization energy monitoring Genechip and application

High-throughput identification of ionizing radiation-sensitive plant genes and development of radiation indicator plant and radiation sensing Genechip

Energy Technology Data Exchange (ETDEWEB)

Kim, Dong Sub; Kim, Jinbaek; Ha, Bokeun; Kim, Sang Hoon; Kim, Sunhee

2013-05-15

Physiological analysis of monocot model plant (rice) in response to ionizing radiation (cosmic-ray, gamma-ray, Ion beam). - Identification of antioxidant characters through cytochemical analysis. - Comparison of antioxidant activities in response to ionizing irradiation. - Evaluation of anthocyanin quantity in response to ionizing irradiation. Ionization energy response gene family analysis via bioinformatic validation. - Expression analysis of monocot and dicot gene families. - In silico and bioinformatic approach to elucidate gene function. Characterization and functional analysis of genes specifically expressed in response to ionizing irradiation (cosmic-ray, gamma-ray, Ion beam). - High throughput trancriptomic analysis of plants under ionizing radiation using microarray. - Promotor and cis-element analysis of genes specifically expressed in response to ionizing radiation. - Validation and function analysis of candidate genes. - Elucidation of plant mechanism of sensing and response to ionization energy. Development of bioindicator plants detecting ionization energy. - Cloning and identification of 'Radio marker genes (RMG)'. - Development of Over-expression (O/E) or Knock-out (K/O) plant using RMG. Development of Genechip as an ionization energy detector. - Expression profiling analysis of genes specifically expression in response to ionization energy. - Prepare high-conserved gene specific oligomer. - Development of ionization energy monitoring Genechip and application.

THE ESCAPE FRACTION OF IONIZING RADIATION FROM GALAXIES

International Nuclear Information System (INIS)

Benson, Andrew; Venkatesan, Aparna; Shull, J. Michael

2013-01-01

The escape of ionizing radiation from galaxies plays a critical role in the evolution of gas in galaxies, and the heating and ionization history of the intergalactic medium. We present semi-analytic calculations of the escape fraction of ionizing radiation for both hydrogen and helium from galaxies ranging from primordial systems to disk-type galaxies that are not heavily dust-obscured. We consider variations in the galaxy density profile, source type, location, and spectrum, and gas overdensity/distribution factors. For sufficiently hard first-light sources, the helium ionization fronts closely track or advance beyond that of hydrogen. Key new results in this work include calculations of the escape fractions for He I and He II ionizing radiation, and the impact of partial ionization from X-rays from early active galactic nuclei or stellar clusters on the escape fractions from galaxy halos. When factoring in frequency-dependent effects, we find that X-rays play an important role in boosting the escape fractions for both hydrogen and helium, but especially for He II. We briefly discuss the implications of these results for recent observations of the He II reionization epoch at low redshifts, as well as the UV data and emission-line signatures from early galaxies anticipated from future satellite missions.

THE ESCAPE FRACTION OF IONIZING RADIATION FROM GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Benson, Andrew [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Venkatesan, Aparna [Department of Physics and Astronomy, University of San Francisco, San Francisco, CA 94117 (United States); Shull, J. Michael, E-mail: abenson@obs.carnegiescience.edu, E-mail: avenkatesan@usfca.edu, E-mail: michael.shull@colorado.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)

2013-06-10

The escape of ionizing radiation from galaxies plays a critical role in the evolution of gas in galaxies, and the heating and ionization history of the intergalactic medium. We present semi-analytic calculations of the escape fraction of ionizing radiation for both hydrogen and helium from galaxies ranging from primordial systems to disk-type galaxies that are not heavily dust-obscured. We consider variations in the galaxy density profile, source type, location, and spectrum, and gas overdensity/distribution factors. For sufficiently hard first-light sources, the helium ionization fronts closely track or advance beyond that of hydrogen. Key new results in this work include calculations of the escape fractions for He I and He II ionizing radiation, and the impact of partial ionization from X-rays from early active galactic nuclei or stellar clusters on the escape fractions from galaxy halos. When factoring in frequency-dependent effects, we find that X-rays play an important role in boosting the escape fractions for both hydrogen and helium, but especially for He II. We briefly discuss the implications of these results for recent observations of the He II reionization epoch at low redshifts, as well as the UV data and emission-line signatures from early galaxies anticipated from future satellite missions.

Exposure to Ionizing Radiation Causes Long-Term Increase in Serum Estradiol and Activation of PI3K-Akt Signaling Pathway in Mouse Mammary Gland

Energy Technology Data Exchange (ETDEWEB)

Suman, Shubhankar [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States); Johnson, Michael D. [Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States); Fornace, Albert J. [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States); Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC (United States); Datta, Kamal, E-mail: kd257@georgetown.edu [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, DC (United States)

2012-10-01

Purpose: Exposure to ionizing radiation is an established risk factor for breast cancer. Radiation exposure during infancy, childhood, and adolescence confers the highest risk. Although radiation is a proven mammary carcinogen, it remains unclear where it acts in the complex multistage process of breast cancer development. In this study, we investigated the long-term pathophysiologic effects of ionizing radiation at a dose (2 Gy) relevant to fractionated radiotherapy. Methods and Materials: Adolescent (6-8 weeks old; n = 10) female C57BL/6J mice were exposed to 2 Gy total body {gamma}-radiation, the mammary glands were surgically removed, and serum and urine samples were collected 2 and 12 months after exposure. Molecular pathways involving estrogen receptor-{alpha} (ER{alpha}) and phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling were investigated by immunohistochemistry and Western blot. Results: Serum estrogen and urinary levels of the oncogenic estrogen metabolite (16{alpha}OHE1) were significantly increased in irradiated animals. Immunostaining for the cellular proliferative marker Ki-67 and cyclin-D1 showed increased nuclear accumulation in sections of mammary glands from irradiated vs. control mice. Marked increase in p85{alpha}, a regulatory sub-unit of the PI3K was associated with increase in Akt, phospho-Akt, phospho-BAD, phospho-mTOR, and c-Myc in irradiated samples. Persistent increase in nuclear ER{alpha} in mammary tissues 2 and 12 months after radiation exposure was also observed. Conclusions: Taken together, our data not only support epidemiologic observations associating radiation and breast cancer but also, specify molecular events that could be involved in radiation-induced breast cancer.

Biological effects of radiation and health risks from exposure to low levels of ionizing radiation

International Nuclear Information System (INIS)

Kotian, Rahul P.; Kotian, Sahana Rahul; Sukumar, Suresh

2013-01-01

The very fact that ionizing radiation produces biological effects is known from many years. The first case of injury reported by Sir Roentgen was reported just after a few months after discovery of X-rays in 1895. As early as 1902, the first case of X-ray induced cancer was reported in the literature. Early human evidence of harmful effects as a result of exposure to radiation in large amounts existed in the 1920s and 1930s, based upon the experience of early radiologists, miners exposed to airborne radioactivity underground, persons working in the radium industry, and other special occupational groups. The long-term biological significance of smaller, repeated doses of radiation, however, was not widely appreciated until relatively recently, and most of our knowledge of the biological effects of radiation has been accumulated since World War II. The mechanisms that lead to adverse health effects after exposure to ionizing radiation are still not fully understood. Ionizing radiation has sufficient energy to change the structure of molecules, including DNA, within the cells of the body. Some of these molecular changes are so complex that it may be difficult for the body's repair mechanisms to mend them correctly. However, the evidence is that only a small fraction of such changes would be expected to result in cancer or other health effects. The most thoroughly studied individuals for the evaluation of health effects of ionizing radiation are the survivors of the Hiroshima and Nagasaki atomic bombings, a large population that includes all ages and both sexes.The Radiation Effects Research Foundation (RERF) in Japan has conducted followup studies on these survivors for more than 50 years. An important finding from these studies is that the occurrence of solid cancers increases in proportion to radiation dose. More than 60% of exposed survivors received a dose of radiation of less than 100 mSv (the definition of low dose used by the BEIR VII report). (author)

Influence of ionizing radiation and 12-crown-4 on coagulation system components of rat blood

International Nuclear Information System (INIS)

Kratenko, R.Yi.

2006-01-01

The influence of 12-crown-4 and ionizing radiation on some components of blood coagulation system: Ca 2+ contents and prostaglandin concentrations in the blood serum, and erythrocyte contents in the blood plasma are studied. The influence of 12-crown-4 and ionizing radiation increases the coagulational properties of erythrocytes. The synergism of ionizing irradiation and 12-crown-4 influence blood coagulation process points out at the occurrence of radiomimetic properties of the latter

Design, construction and characterization of special ionization chambers for X radiation beams monitoring

International Nuclear Information System (INIS)

Yoshizumi, Maira Tiemi

2010-01-01

X radiation equipment may show fluctuations in the radiation beam intensity, as they are connected to the power net. These intensity variations can, in turn, modify the air kerma rate produced by this radiation beam. In a calibration laboratory, where radiation detectors (from clinics and hospital services) are calibrated, variations in the radiation beam intensity may cause an error in the absorbed dose determination. The monitor ionization chambers are used to verify the radiation beam intensity constancy, and to provide a correction for possible fluctuations. In this work, monitor ionization chambers for X radiation beams were designed, assembled and characterized. The developed ionization chambers have an innovative design, ring-shaped, with aluminium or graphite electrodes. These ring-shaped ionization chambers have the advantage of not interfering in the direct radiation beams. A double-volume ionization chamber with graphite electrodes was also developed. This ionization chamber is similar to the commercial monitor ionization chamber used in the Calibration Laboratory of the Instituto de Pesquisas Energeticas e Nucleares. All developed ionization chambers were tested in several standardized radiation beams and their performances were compared with those of commercial ionization chambers. The results show that two of the four ionization chambers developed showed performance comparable to that of the commercial ionization chambers tested. Besides presenting good results, the ionization chambers were designed and manufactured using low cost materials, which are easily found on the Brazilian market. (author)

Metastatic spreading and growth of rhabdomyosarcoma in exposure to hyperglycemia, hyperthermia and ionizing radiation

International Nuclear Information System (INIS)

Ul'yanenko, S.E.; Salamatina, N.A.; Dedenkov, A.N.

1985-01-01

Under the effect of local UHF-hyperthermia, short-term hyperglycemia and ionizing radiation on metastasing strain of rhabdomysarcoma an increase in metastatic spreading or stimulated growth of primary tumor are not noticed. Otherwise, it is stated that hyperglycemia and hyperthermia thrice-used prevent from metastatic spreading of the tumor. Ionizing radiation decelerates both tumor growth and to a least extent its metastatic spreading

Radiation protection requirements for medical application of ionizing radiation in the Republic of Macedonia

International Nuclear Information System (INIS)

Nestoroska, Svetlana; Angelovski, Goran; Shahin, Nuzi

2010-01-01

In this paper, the regulatory infrastructure in radiation protection in the Republic of Macedonia is presented. The national radiation protection requirements for the medical application of ionizing radiation are reviewed for both occupational exposed persons and patients undergoing a medical treatment with ionizing radiation and their compliance with the international standards is considered. The gaps identified on the national level are presented and steps for overcoming such gaps are analyzed.(Author)

Polymers under ionizing radiation: the study of energy transfers to radiation induced defects

International Nuclear Information System (INIS)

Ventura, A.

2013-01-01

Radiation-induced defects created in polymers submitted to ionizing radiations, under inert atmosphere, present the same trend as a function of the dose. When the absorbed dose increases, their concentrations increase then level off. This behavior can be assigned to energy transfers from the polymer to the previously created macromolecular defects; the latter acting as energy sinks. During this thesis, we aimed to specify the influence of a given defect, namely the trans-vinylene, in the behavior of polyethylene under ionizing radiations. For this purpose, we proposed a new methodology based on the specific insertion, at various concentrations, of trans-vinylene groups in the polyethylene backbone through chemical synthesis. This enables to get rid of the variety of created defects on one hand and on the simultaneity of their creation on the other hand. Modified polyethylenes, containing solely trans-vinylene as odd groups, were irradiated under inert atmosphere, using either low LET beams (gamma, beta) or high LET beams (swift heavy ions). During irradiations, both macromolecular defects and H 2 emission were quantified. According to experimental results, among all defects, the influence of the trans-vinylene on the behavior of polyethylene is predominant. (author) [fr

Protection in handling ionizing radiation sources in national economy

International Nuclear Information System (INIS)

1986-01-01

The collection of study texts is divided into 13 chapters giving an explanation of the structure of the atom, the properties of ionizing radiation and its interactions, quantities and units used, basic dosimetric methods, biological radiation effects, the sources of population exposure, the principles of radiation protection, technological applications of ionizing radiation, the monitoring of personnel and environment, the method of recording and filing, the method of protection from external radiation and internal contamination, health care, and requirements for protection in handling nonsealed sources. (M.D.)

Ionizing radiation treatment to improve postharvest life and maintain quality of fresh guava fruit

International Nuclear Information System (INIS)

Singh, S.P.; Pal, R.K.

2009-01-01

We investigated the potential of ionizing radiation for improving physiological responses, quality, and storage time of fresh guava fruit. Ionizing radiation treatment suppressed the respiration and ethylene production rates and thus retarded the process of fruit ripening during storage. Irradiation treatment also retarded the physical and biochemical changes associated with ripening such as firmness, titratable acidity, soluble solids content, and vitamin C during storage, but for doses higher than 0.25 kGy the vitamin C content decreased. The positive effects of ionizing radiation treatment on delayed fruit ripening and other quality attributes diminished during 22 days of storage at 10 deg. C. Thus, a combination of ionizing radiation with low-temperature storage (10 deg. C) did not have much synergistic effect on storage life and quality of guava fruit. In conclusion, ionizing radiation treatment of guava fruit with 0.25 kGy dose increased the postharvest life by 3-4 days, maintained fruit quality, and reduced the decay incidence. The optimal dose (0.25 kGy) for postharvest life extension of guava fruit may be exploited to provide phytosanitary security against many insect pests including fruit flies

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.

Initial events in the cellular effects of ionizing radiations: clustered damage in DNA

International Nuclear Information System (INIS)

Goodhead, D.T.

1994-01-01

Ionizing radiations produce many hundreds of different simple chemical products in DNA and also multitudes of possible clustered combinations. The simple products, including single-strand breaks, tend to correlate poorly with biological effectiveness. Even for initial double-strand breaks, as a broad class, there is apparently little or no increase in yield with increasing ionization density, in contrast with the large rise in relative biological effectiveness for cellular effects. Track structure analysis has revealed that clustered DNA damage of severity greater than simple double-strand breaks is likely to occur at biologically relevant frequencies with all ionizing radiations. Studies are in progress to describe in more detail the chemical nature of these clustered lesions and to consider the implications for cellular repair. (author)

Review on evolvement of systems of ionizing radiation quantities and units

International Nuclear Information System (INIS)

Zheng Junzheng; Zeng Zhi

2009-01-01

To scientifically and practically measure the ionizing radiation in unison is an indispensable prerequisite and foundation for the extensive uses of nuclear science and technology, development of radiological protection and safety standards, as well as prevention and treatment of ionizing radiation hazards. Concerning about the quantities and units of ionizing radiation as well as their corresponding measurement and application methods, relevant international organizations and all countries in the world generally adopt the systems proposed by the International Commission on Radiation Units and Measurements (ICRU) which is a well recognized and authoritative academic organization.In the paper,the major evolutions of the systems for ionizing radiation quantities and units in the past decades are summarized. (authors)

Surface and Bulk Nanostructuring of Polymers Using Ionizing Radiation

Energy Technology Data Exchange (ETDEWEB)

Güven, O.; Barsbay, M.; Ateş,; Akbulut, M. [Hacettepe University, Department of Chemistry, Ankara (Turkey)

2009-07-01

Ionizing radiation has long been known tobe a powerful tool in modifying and controlled the properties, forms and eventually end-uses of polymeric materials for a variety of applications. Industrial applications are full of successful examples of macro scale, bulk property modifications by radiation. Extremely short wavelength of ionizing radiation however, makes it an important and useful tool in creating very small size structures in polymers.

Surface and Bulk Nanostructuring of Polymers Using Ionizing Radiation

International Nuclear Information System (INIS)

Güven, O.; Barsbay, M.; Ateş; Akbulut, M.

2009-01-01

Ionizing radiation has long been known tobe a powerful tool in modifying and controlled the properties, forms and eventually end-uses of polymeric materials for a variety of applications. Industrial applications are full of successful examples of macro scale, bulk property modifications by radiation. Extremely short wavelength of ionizing radiation however, makes it an important and useful tool in creating very small size structures in polymers

The industrial applications of ionizing radiations

International Nuclear Information System (INIS)

1992-10-01

This report presents all industrial applications of ionizing radiations in France, for food preservation, radiosterilization of drugs, medical materials and cosmetic products, for radiation chemistry of polymers. This report also describes the industrial plants of irradiation (electron, cobalt 60). Finally, it explains the legal and safety aspects

Radiation monitoring in a synchrotron light source facility using magnetically levitated electrode ionization chambers

International Nuclear Information System (INIS)

Ichiki, Hirofumi; Kawaguchi, Toshirou; Utsunomiya, Yoshitomo; Ishibashi, Kenji; Ikeda, Nobuo; Korenaga, Kazuhito

2009-01-01

We developed a highly accurate differential-type automatic radiation dosimeter to measure very low radiation doses. The dosimeter had two ionization chambers, each of which had a magnetically levitated electrode and it was operated in a repetitive-time integration mode. We first installed the differential-type automatic radiation dosimeter with MALICs at a high-energy electron accelerator facility (Kyushu Synchrotron Light Research Center Facility) and measured the background and ionizing radiations in the facility as well as the gaseous radiation in air. In the background dose measurements, the accuracy of the repetitive-time integration-type dosimeter was three times better than that of a commercial ionization chamber. When the radiation dose increased momentarily at the electron injection from the linac to the operating storage ring, the dosimeter with repetitive-time integral mode gave a successful response to the actual dose variation. The gaseous radiation dose in the facility was at the same level as that in Fukuoka City. We confirmed that the dosimeter with magnetically levitated electrode ionization chambers was usable in the accelerator facility, in spite of its limited response when operated in the repetitive-time integration mode. (author)

Effect of Ionizing Beta Radiation on the Mechanical Properties of Poly(ethylene under Thermal Stress

Directory of Open Access Journals (Sweden)

Bednarik Martin

2016-01-01

Full Text Available It was found in this study, that ionizing beta radiation has a positive effect on the mechanical properties of poly(ethylene. In recent years, there have been increasing requirements for quality and cost effectiveness of manufactured products in all areas of industrial production. These requirements are best met with the polymeric materials, which have many advantages in comparison to traditional materials. The main advantages of polymer materials are especially in their ease of processability, availability, and price of the raw materials. Radiation crosslinking is one of the ways to give the conventional plastics mechanical, thermal, and chemical properties of expensive and highly resistant construction polymers. Several types of ionizing radiation are used for crosslinking of polymers. Each of them has special characteristics. Electron beta and photon gamma radiation are used the most frequently. The great advantage is that the crosslinking occurs after the manufacturing process at normal temperature and pressure. The main purpose of this paper has been to determine the effect of ionizing beta radiation on the tensile modulus, strength and elongation of low and high density polyethylene (LDPE and HDPE. These properties were examined in dependence on the dosage of the ionizing beta radiation (non-irradiated samples and those irradiated by dosage 99 kGy were compared and on the test temperature. Radiation cross-linking of LDPE and HDPE results in increased tensile strength and modulus, and decreased of elongation. The measured results indicate that ionizing beta radiation treatment is effective tool for improvement of mechanical properties of LDPE and HDPE under thermal stress.

Disordered redox metabolism of brain cells in rats exposed to low doses of ionizing radiation or UHF electromagnetic radiation.

Science.gov (United States)

Burlaka, A P; Druzhyna, M O; Vovk, A V; Lukin, S М

2016-12-01

To investigate the changes of redox-state of mammalian brain cells as the critical factor of initiation and formation of radiation damage of biological structures in setting of continuous exposure to low doses of ionizing radiation or fractionated ultra high frequency electromagnetic radiation (UHF EMR) at non-thermal levels. The influence of low-intensity ionizing radiation was studied on outbred female rats kept for 1.5 years in the Chernobyl accident zone. The effects of total EMR in the UHF band of non-thermal spectrum were investigated on Wistar rats. The rate of formation of superoxide radicals and the rate of NO synthesis in mitochondria were determined by the EPR. After exposure to ionizing or UHF radiation, the levels of ubisemiquinone in brain tissue of rats decreased by 3 and 1.8 times, respectively. The content of NO-FeS-protein complexes in both groups increased significantly (р < 0.05). In the conditions of ionizing or EMR the rates of superoxide radical generation in electron-transport chain of brain cell mitochondria increased by 1.5- and 2-fold, respectively (р < 0.05). In brain tissue of rats kept in the Chernobyl zone, significant increase of NO content was registered; similar effect was observed in rats treated with UHFR (р < 0.05). The detected changes in the electron transport chain of mitochondria of brain cells upon low-intensity irradiation or UHF EMR cause the metabolic reprogramming of cell mitochondria that increases the rate of superoxide radical generation and nitric oxide, which may initiate the development of neurodegenerative diseases and cancer. This article is part of a Special Issue entitled "The Chornobyl Nuclear Accident: Thirty Years After".

Natural sources of ionizing radiations

International Nuclear Information System (INIS)

Marej, A.N.

1984-01-01

Natural sources of ionizing radiations are described in detail. The sources are subdivided into sources of extraterrestrial origin (cosmic radiation) and sources of terrestrial origin. Data on the concentration of different nuclides in rocks, various soils, ground waters, atmospheric air, tissues of plants and animals, various food stuffs are presented. The content of natural radionuclides in environmental objects, related to human activities, is discussed

Biological effects of low-dose ionizing radiation exposure

International Nuclear Information System (INIS)

Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

2009-01-01

The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

Influence of ionizing radiation on the plasma membrane proteins

International Nuclear Information System (INIS)

Dreval', V.I.

1992-01-01

The effect of ionizing radiation on the meat cattle thymocytes plasma membranes was studied. Using fluorescence quenching technique the effect of irradiation of proteins conformation was investigated. The influence of ionizing radiation on the plasma membranes was shown to be followed by changes of the protein structure-dynamic organization

Effects of low doses of ionizing radiation

International Nuclear Information System (INIS)

Anon.

2008-01-01

Ionizing radiation of cosmic or terrestrial origin is part of the environment in which all living things have evolved since the creation of the universe. The artificial radioactivity generated by medical diagnostic and treatment techniques, some industrial activities, radioactive fallout, etc. has now been added to this natural radioactivity. This article reviews the biological effects of the low doses of ionizing radiation to which the population is thus exposed. Their carcinogenic risk cannot simply be extrapolated from what we know about high-dose exposure. (author)

Effects of ionizing radiation on the immune system

International Nuclear Information System (INIS)

Dubois, J.B.

1986-01-01

After reviewing the different lymphoid organs and the essential phases of the immune response, we studied the morphological and functional effects of ionizing radiation on the immunological system. Histologic changes in the lymph nodes, spleen, thymus, and different lymphocyte subpopulations were studied in relation with the radiation dose and irradiated volume (whole body irradiation, localized irradiation). Functional changes in the immune system induced by ionizing radiation were also investigated by a study of humoral-mediated immunity (antibody formation) and cell-mediated immunity (behavior of macrophages, B-cells, T suppressor cells, T helper cells, T effector cells, and natural killer cells). A study into the mechanisms of action of ionizing radiation and the immune processes it interferes with suggests several likely hypotheses (direct action on the immune cells, on their precursors, on seric mediators or on cell mediators). The effects on cancer patients' immune reactions of low radiation doses delivered to the various lymphoid organs are discussed, as well as the relationships between the host and the evolution of the tumor [fr

Ionizing radiation detector using multimode optical fibers

International Nuclear Information System (INIS)

Suter, J.J.; Poret, J.C.; Rosen, M.; Rifkind, J.M.

1993-01-01

An optical ionizing radiation detector, based on the attenuation of 850-nm light in 50/125-μm multimode fibers, is described. The detector is especially well suited for application on spacecraft because of its small design. The detection element consists of a section of coiled fibers that has been designed to strip higher-order optical modes. Cylindrical radiation shields with atomic numbers ranging from Z = 13 (aluminum too) Z = 82 (lead) were placed around the ionizing radiation detector so that the effectiveness of the detector could be measured. By exposing the shields and the detector to 1.25-MeV cobalt 60 radiation, the mass attenuation coefficients of the shields were measured. The detector is based on the phenomenon that radiation creates optical color centers in glass fibers. Electron spin resonance spectroscopy performed on the 50/125-μm fibers showed the presence of germanium oxide and phosphorus-based color centers. The intensity of these centers is directly related to the accumulated gamma radiation

Monitoring occupational exposure to ionizing radiation

International Nuclear Information System (INIS)

Button, J.B.C.

1997-01-01

A brief overview is presented of methods of monitoring occupational exposure to ionizing radiation together with reasons for such monitoring and maintaining dose histories of radiation occupationally exposed persons. The various Australian providers of external radiation monitoring services and the types of dosemeters they supply are briefly described together with some monitoring results. Biological monitoring methods, are used to determine internal radiation dose. Whole body monitors, used for this purpose are available at Australian Radiation Lab., ANSTO and a few hospitals. Brief mention is made of the Australian National Radiation Dose Register and its objectives

To manage the ionizing radiations risks

International Nuclear Information System (INIS)

Metivier, H.; Romerio, F.

2000-01-01

Mister Romerio's work tackles the problem of controversy revealed by the experts in the field of estimation and management of ionizing radiations risks. The author describes the three paradigms at the base of the debate: the relationship without threshold (typified by the ICRP and its adepts), these ones that think that low doses risks are overestimated ( Medicine Academia for example) or that ones that believe that dose limits are too severe and induce unwarranted costs; then that ones that think that these risks are under-estimated and limits should be more reduced, even stop these practices that lead to public exposure to ionizing radiations. The author details the uncertainties about the risk estimations, refreshes the knowledge in radiation protection with the explanations of the different paradigms. At the end a table summarize the positions of the three paradigms

Ionizing radiation calculations and comparisons with LDEF data

Science.gov (United States)

Armstrong, T. W.; Colborn, B. L.; Watts, J. W., Jr.

1992-01-01

In conjunction with the analysis of LDEF ionizing radiation dosimetry data, a calculational program is in progress to aid in data interpretation and to assess the accuracy of current radiation models for future mission applications. To estimate the ionizing radiation environment at the LDEF dosimeter locations, scoping calculations for a simplified (one dimensional) LDEF mass model were made of the primary and secondary radiations produced as a function of shielding thickness due to trapped proton, galactic proton, and atmospheric (neutron and proton cosmic ray albedo) exposures. Preliminary comparisons of predictions with LDEF induced radioactivity and dose measurements were made to test a recently developed model of trapped proton anisotropy.

Decomposition of persistent pharmaceuticals in wastewater by ionizing radiation

International Nuclear Information System (INIS)

Kimura, Atsushi; Osawa, Misako; Taguchi, Mitsumasa

2012-01-01

Pharmaceuticals in wastewater were treated by the combined method of activated sludge and ionizing radiation in laboratory scale. Oseltamivir, aspirin, and ibuprofen at 5 μmol dm −3 in wastewater were decomposed by the activated sludge at reaction time for 4 h. Carbamazepine, ketoprofen, mefenamic acid, clofibric acid, and diclofenac were not biodegraded completely, but were eliminated by γ-ray irradiation at 2 kGy. The rate constants of the reactions of these pharmaceuticals with hydroxyl radicals were estimated by the competition reaction method to be 4.0–10×10 9 mol −1 dm 3 s −1 . Decompositions of the pharmaceuticals in wastewater by ionizing radiation were simulated by use of the rate constants and the amount of total organic carbon as parameters. Simulation curves of concentrations of these pharmaceuticals as a function of dose described the experimental data, and the required dose for the elimination of them in wastewater by ionizing radiation can be estimated by this simulation. - Highlights: ► We treat pharmaceuticals in wastewater by activated sludge and ionizing radiation. ► Activated sludge decreases the amounts of total organic carbons in wastewater. ► Pharmaceuticals were decomposed by γ-ray irradiation at 2 kGy. ► We construct simulation for treatment of pharmaceuticals by ionizing radiation.

Relative effectiveness of ionizing radiations in relation to LET and the influence of oxygen

International Nuclear Information System (INIS)

Barendsen, G.W.

1966-01-01

phenomena in terms of a specific model is its potentiality to account for the modification of radiation-induced effects by protecting and potentiating agents. It has been demonstrated with various systems that cells in anoxic conditions are less sensitive to ionizing radiations than oxygenated cells. In addition, it has been observed that this enhancing action of oxygen depends on the type of ionizing radiation used and generally decreases with increasing LET. The present contribution describes a comparison and analysis of the RBE- LET relations for impairment of the proliferative capacity of cultured human cells irradiated in oxygenated and anoxic conditions

Cancer risk from low doses of ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Auvinen, A

1997-06-01

The aim of the study was to estimate cancer risk from small doses of ionizing radiation from various sources, including both external and internal exposure. The types of radiation included alpha, gamma, and neutron radiation. A nationwide follow-up study covering the years up to 1992 revealed no significant association between fallout from the Chernobyl accident and incidence of childhood leukemia. An excess of eight cases or more per year could be excluded. However, some indication of an increase was evident in the most heavily affected areas. Furthermore, the risk estimates were in accordance with those reported from Hiroshima and Nagasaki, although the confidence intervals were wide. (282 refs.).

Cancer risk from low doses of ionizing radiation

International Nuclear Information System (INIS)

Auvinen, A.

1997-06-01

The aim of the study was to estimate cancer risk from small doses of ionizing radiation from various sources, including both external and internal exposure. The types of radiation included alpha, gamma, and neutron radiation. A nationwide follow-up study covering the years up to 1992 revealed no significant association between fallout from the Chernobyl accident and incidence of childhood leukemia. An excess of eight cases or more per year could be excluded. However, some indication of an increase was evident in the most heavily affected areas. Furthermore, the risk estimates were in accordance with those reported from Hiroshima and Nagasaki, although the confidence intervals were wide. (282 refs.)

Child-bearing function in women with ionizing radiation

International Nuclear Information System (INIS)

Vusik, I.M.; Kogan, I.A.

1979-01-01

Study on a generating function in 393 women working in the sphere of ionizing radiation effect has shown that when working without exceeding the permissible irradiation level of 5 rem/year, some strengthening of this function is observed while working, with a considerable excess of permissible irradiation doses at the reproductive age, the decrease of childbirth and the increase in the number of miscarriages and premature birth are noted. The growth of girl childbirth as compared with boy childbirth is proportional to radiation load during the work with radiation sources. The secondary sterility appears in the same number of women exposed to the occupational irradiation and women of a control group

Measuring ionizing radiation with a mobile device

Science.gov (United States)

Michelsburg, Matthias; Fehrenbach, Thomas; Puente León, Fernando

2012-02-01

In cases of nuclear disasters it is desirable to know one's personal exposure to radioactivity and the related health risk. Usually, Geiger-Mueller tubes are used to assess the situation. Equipping everyone with such a device in a short period of time is very expensive. We propose a method to detect ionizing radiation using the integrated camera of a mobile consumer device, e.g., a cell phone. In emergency cases, millions of existing mobile devices could then be used to monitor the exposure of its owners. In combination with internet access and GPS, measured data can be collected by a central server to get an overview of the situation. During a measurement, the CMOS sensor of a mobile device is shielded from surrounding light by an attachment in front of the lens or an internal shutter. The high-energy radiation produces free electrons on the sensor chip resulting in an image signal. By image analysis by means of the mobile device, signal components due to incident ionizing radiation are separated from the sensor noise. With radioactive sources present significant increases in detected pixels can be seen. Furthermore, the cell phone application can make a preliminary estimate on the collected dose of an individual and the associated health risks.

Genetic effects of ionizing radiation – some questions with no answers

International Nuclear Information System (INIS)

Mosse, Irma B.

2012-01-01

There are a lot of questions about genetic effects of ionizing radiation, the main one is does ionizing radiation induce mutations in humans? There is no direct evidence that exposure of parents to radiation leads to excess heritable disease in offspring. What is the difference between human and other species in which radiation induced mutations are easily registered? During evolution germ cell selection ex vivo has been changed to a selection in vivo and we cannot observe such selection of radiation damaged cells in human. Low radiation doses – are they harmful or beneficial? The “hormesis” phenomenon as well as radioadaptive response proves positive effects of low radiation dose. Can analysis of chromosomal aberration rate in lymphocytes be used for dosimetry? Many uncontrolled factors may be responsible for significant mistakes of this method. Why did evolution preserve the bystander effect? This paper is discussion one and its goal is to pay attention on some effects of ionizing radiation. - Highlights: ► There are a lot of questions about genetic effects of ionizing radiation. ► Does ionizing radiation induce mutations in human? ► During evolution germ cell selection ex vivo has been changed to a selection in vivo. ► Radioadaptive response proves positive effects of low radiation doses. ► Many uncontrolled factors may be responsible for significant biodosimetry mistakes.

The situation of knowledge on ionizing radiation

International Nuclear Information System (INIS)

2005-01-01

Occupational exposure to ionizing radiation occurs: during sources use, during the use of matter including radioactivity used for other properties than their radioactivity, in presence of natural radioactivity on the working area, following an accident during an industrial process. to protect man taken into account the incurred risk, goes by the risk evaluation, in taking into account the industrial process and exposure conditions of persons, then by the application of prevention measures that aim to control the contamination risks by radioactive matters as well as the exposure risks to ionizing radiations. (N.C.)

Ionizing radiation in earth's atmosphere and in space near earth.

Science.gov (United States)

2011-05-01

The Civil Aerospace Medical Institute of the FAA is charged with identifying health hazards in air travel and in : commercial human space travel. This report addresses one of these hazards ionizing radiation. : Ionizing radiation is a subatomic p...

Time- and dose-dependent effects of total-body ionizing radiation on muscle stem cells

Science.gov (United States)

Masuda, Shinya; Hisamatsu, Tsubasa; Seko, Daiki; Urata, Yoshishige; Goto, Shinji; Li, Tao-Sheng; Ono, Yusuke

2015-01-01

Exposure to high levels of genotoxic stress, such as high-dose ionizing radiation, increases both cancer and noncancer risks. However, it remains debatable whether low-dose ionizing radiation reduces cellular function, or rather induces hormetic health benefits. Here, we investigated the effects of total-body γ-ray radiation on muscle stem cells, called satellite cells. Adult C57BL/6 mice were exposed to γ-radiation at low- to high-dose rates (low, 2 or 10 mGy/day; moderate, 50 mGy/day; high, 250 mGy/day) for 30 days. No hormetic responses in proliferation, differentiation, or self-renewal of satellite cells were observed in low-dose radiation-exposed mice at the acute phase. However, at the chronic phase, population expansion of satellite cell-derived progeny was slightly decreased in mice exposed to low-dose radiation. Taken together, low-dose ionizing irradiation may suppress satellite cell function, rather than induce hormetic health benefits, in skeletal muscle in adult mice. PMID:25869487

Study on ionizing radiation effects of bipolar transistor with BPSG films

International Nuclear Information System (INIS)

Lu Man; Zhang Xiaoling; Xie Xuesong; Sun Jiangchao; Wang Pengpeng; Lu Changzhi; Zhang Yanxiu

2013-01-01

Background: Because of the damage induced by ionizing radiation, bipolar transistors in integrated voltage regulator could induce the current gain degradation and increase leakage current. This will bring serious problems to electronic system. Purpose: In order to ensure the reliability of the device work in the radiation environments, the device irradiation reinforcement technology is used. Methods: The characteristics of 60 Co γ irradiation and annealing at different temperatures in bipolar transistors and voltage regulators (JW117) with different passive films for SiO 2 +BPSG+SiO 2 and SiO 2 +SiN have been investigated. Results: The devices with BPSG film enhanced radiation tolerance significantly. Because BPSG films have better absorption for Na + in SiO 2 layer, the surface recombination rate of base region in a bipolar transistor and the excess base current have been reduced. It may be the main reason for BJT with BPSG film having a good radiation hardness. And annealing experiments at different temperatures after irradiation ensure the reliability of the devices with BPSG films. Conclusions: A method of improving the ionizing irradiation hardness of bipolar transistors is proposed. As well as the linear integrated circuits which containing bipolar transistors, an experimental basis for the anti-ionizing radiation effects of bipolar transistors is provided. (authors)

Long-term effects of ionizing radiation

International Nuclear Information System (INIS)

Kaul, Alexander; Burkart, Werner; Grosche, Bernd; Jung, Thomas; Martignoni, Klaus; Stephan, Guenther

1997-01-01

This paper approaches the long-term effects of ionizing radiation considering the common thought that killing of cells is the basis for deterministic effects and that the subtle changes in genetic information are important in the development of radiation-induced cancer, or genetic effects if these changes are induced in germ cells

Performance of a pencil ionization chamber in various radiation beams

International Nuclear Information System (INIS)

Maia, A.F.; Caldas, L.V.E.

2003-01-01

Pencil ionization chambers were recommended for use exclusively in the computed tomography (CT) dosimetry, and, from the start, they were developed only with this application in view. In this work, we studied the behavior of a pencil ionization chamber in various radiation beams with the objective of extending its application. Stability tests were performed, and calibration coefficients were obtained for several standard radiation qualities of the therapeutical and diagnostic levels. The results show that the pencil ionization chamber can be used in several radiation beams other than those used in CT

Evaluation of the genotoxic effects of chronic low-dose ionizing radiation exposure on nuclear medicine workers

Energy Technology Data Exchange (ETDEWEB)

Sahin, Ali [Department of Nuclear Medicine, Faculty of Medicine, Medical School, Ataturk University, Erzurum (Turkey)], E-mail: alibabam2001@yahoo.com; Tatar, Abdulgani; Oztas, Sitki [Department of Genetics, Faculty of Medicine, Ataturk University, 25240 Erzurum (Turkey); Seven, Bedri; Varoglu, Erhan [Department of Nuclear Medicine, Faculty of Medicine, Medical School, Ataturk University, Erzurum (Turkey); Yesilyurt, Ahmet [Department of Genetics, Faculty of Medicine, Ataturk University, 25240 Erzurum (Turkey); Ayan, Arif Kursad [Department of Nuclear Medicine, Faculty of Medicine, Medical School, Ataturk University, Erzurum (Turkey)

2009-07-15

Introduction: Nuclear medicine workers are occupationally exposed to chronic ionizing radiation. It is known that ionizing radiation may have damaging effects on chromosomes. In the present study, we investigated the genotoxic effects of ionizing radiation on nuclear medicine workers. We used two different indicators of genotoxicity methods: sister chromatid exchange (SCE) and micronucleus (MN). Methods: The present research was carried out using 21 nuclear medicine workers (11 females and 10 males) during two periods: during normal working conditions and after a 1-month vacation. The radiation dose varied from 1.20 to 48.56 mSv, which accumulated during the occupational exposure time between two vacations. Peripheral blood samples were taken from each subject for two distinct lymphocyte cultures (SCE and MN) in each period. Results: In nearly all subjects, SCE values increased significantly during radiation exposure compared to the postvacation period (P<.05). Similarly, MN frequencies in most of the subjects increased significantly during radiation exposure compared to the postvacation period (P<.05). Conclusions: This study revealed that both SCE and MN frequencies in most of the subjects were significantly higher during exposure to ionizing radiation than after a 1-month vacation period. However, this genotoxic effect was reversible in most of the subjects.

Evaluation of the genotoxic effects of chronic low-dose ionizing radiation exposure on nuclear medicine workers

International Nuclear Information System (INIS)

Sahin, Ali; Tatar, Abdulgani; Oztas, Sitki; Seven, Bedri; Varoglu, Erhan; Yesilyurt, Ahmet; Ayan, Arif Kursad

2009-01-01

Introduction: Nuclear medicine workers are occupationally exposed to chronic ionizing radiation. It is known that ionizing radiation may have damaging effects on chromosomes. In the present study, we investigated the genotoxic effects of ionizing radiation on nuclear medicine workers. We used two different indicators of genotoxicity methods: sister chromatid exchange (SCE) and micronucleus (MN). Methods: The present research was carried out using 21 nuclear medicine workers (11 females and 10 males) during two periods: during normal working conditions and after a 1-month vacation. The radiation dose varied from 1.20 to 48.56 mSv, which accumulated during the occupational exposure time between two vacations. Peripheral blood samples were taken from each subject for two distinct lymphocyte cultures (SCE and MN) in each period. Results: In nearly all subjects, SCE values increased significantly during radiation exposure compared to the postvacation period (P<.05). Similarly, MN frequencies in most of the subjects increased significantly during radiation exposure compared to the postvacation period (P<.05). Conclusions: This study revealed that both SCE and MN frequencies in most of the subjects were significantly higher during exposure to ionizing radiation than after a 1-month vacation period. However, this genotoxic effect was reversible in most of the subjects.

Radiation protection in the application of ionizing radiation in industry

International Nuclear Information System (INIS)

Mohamad Yusof Mohamad Ali

1987-01-01

There is a substantial increase in the use of ionizing radiation in industry throughout the country especially in the last five years or so. With this growth in the number of users and activity of sources used, and together with the introduction of the new Atomic Energy Licensing Act (AELA) in 1984, the question of radiation safety and protection of workers and members of the public in general, can no longer be taken lightly. It has to be dealt with effectively. In this paper, a general discussion and clarification on certain practical aspects of radiation protection as recommended by the International Atomic Energy Agency (IAEA) is presented. Amongst the topics chosen are those on area monitoring, personnel monitoring, leak testing of sealed sources and training of personnel. Also presented in the paper is a brief discussion about UTN's experience in giving out radiation protection services to various agencies throughout the country. (author)

Targeted and non-targeted effects of ionizing radiation

OpenAIRE

Omar Desouky; Nan Ding; Guangming Zhou

2015-01-01

For a long time it was generally accepted that effects of ionizing radiation such as cell death, chromosomal aberrations, DNA damage, mutagenesis, and carcinogenesis result from direct ionization of cell structures, particularly DNA, or from indirect damage through reactive oxygen species produced by radiolysis of water, and these biological effects were attributed to irreparable or misrepaired DNA damage in cells directly hit by radiation. Using linear non-threshold model (LNT), possible ris...

Atmospheric Ionizing Radiation and Human Exposure

Science.gov (United States)

Wilson, John W.; Mertens, Christopher J.; Goldhagen, Paul; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.

2005-01-01

Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes. especially along the coastal plain and interior low lands, and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.

Atmospheric Ionizing Radiation and Human Exposure

Science.gov (United States)

Wilson, J. W.; Goldhagen, P.; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.

2004-01-01

Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes especially along the coastal plain and interior low lands and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.

Ground-Level Ozone Following Astrophysical Ionizing Radiation Events: An Additional Biological Hazard?

Science.gov (United States)

Thomas, Brian C; Goracke, Byron D

2016-01-01

Astrophysical ionizing radiation events such as supernovae, gamma-ray bursts, and solar proton events have been recognized as a potential threat to life on Earth, primarily through depletion of stratospheric ozone and subsequent increase in solar UV radiation at Earth's surface and in the upper levels of the ocean. Other work has also considered the potential impact of nitric acid rainout, concluding that no significant threat is likely. Not yet studied to date is the potential impact of ozone produced in the lower atmosphere following an ionizing radiation event. Ozone is a known irritant to organisms on land and in water and therefore may be a significant additional hazard. Using previously completed atmospheric chemistry modeling, we examined the amount of ozone produced in the lower atmosphere for the case of a gamma-ray burst and found that the values are too small to pose a significant additional threat to the biosphere. These results may be extended to other ionizing radiation events, including supernovae and extreme solar proton events.

Monitoring occupational exposure to ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Button, J.B.C. [Radiation Safety Consultancy, Engadine, NSW (Australia)

1997-12-31

A brief overview is presented of methods of monitoring occupational exposure to ionizing radiation together with reasons for such monitoring and maintaining dose histories of radiation occupationally exposed persons. The various Australian providers of external radiation monitoring services and the types of dosemeters they supply are briefly described together with some monitoring results. Biological monitoring methods, are used to determine internal radiation dose. Whole body monitors, used for this purpose are available at Australian Radiation Lab., ANSTO and a few hospitals. Brief mention is made of the Australian National Radiation Dose Register and its objectives. 8 refs., 9 tabs.

Ionizing radiations and health. Exposures, epidemiological surveillance and sociological monitoring measurements

International Nuclear Information System (INIS)

Spira, Alfred; Boutou, Odile

1999-01-01

This paper draws attention to the epidemiological effect of natural and artificial ionizing radiation exposures on man. It describes ionizing radiation sources from nuclear facilities and medical establishments. The case here is in the region of La Hague in France where 4800 employees are exposed to ionizing radiations. The topic of leukemia research and thyroid studies for children in the region are discussed. The impact of radiations on fertility, life quality is covered. Finally, national propositions to establish a monitoring measurement system is also discussed including the personnel and the general population exposed

Radioprotective properties of tocopherol succinate against ionizing radiation in mice

International Nuclear Information System (INIS)

Singh, V.K.; Singh, P.K.; Wise, S.Y.; Posarac, A.; Fatanmi, O.O.

2013-01-01

Threats of nuclear and other radiologic exposures have been increasing but no countermeasure for acute radiation syndrome has been approved by regulatory authorities. In prior publications we have demonstrated the efficacy of tocopherol succinate (TS) as a promising radiation countermeasure with the potential to protect against lethal doses of ionizing radiation exposure. The aim of this study was to gain further insight regarding how TS protects mice against a lethal dose of radiation. CD2F1 mice were injected subcutaneously with 400 mg/kg of TS, and 24 h later exposed to 60 Co γ-radiation. Intestinal tissues or spleen/thymus were harvested after irradiation and analyzed for CD68-positive inflammatory cells and apoptotic cells by immunostaining of jejunal cross-sections. Comet assay was used to analyze DNA damage in various tissues. Phospho-histone H3 (pH3) and the proliferating cell nuclear antigen (PCNA) were used as mitotic markers for immunostaining jejunal cross-sections. We observed that injecting TS significantly decreased the number of CD68-positive cells, DNA damage and apoptotic cells (bcl-associated X protein (BAX), caspase 3 and cleaved poly (ADP-ribose) polymerase-positive cells) as judged by various apoptotic pathway markers. TS treatment also increased proliferating cells in irradiated mice. Results of this study further support our contention that TS protects mice against lethal doses of ionizing radiation by inhibiting radiation-induced apoptosis and DNA damage while enhancing cell proliferation. (author)

Radioprotection in the medical applications of the ionizing radiations

International Nuclear Information System (INIS)

2001-01-01

This publication presents information about of the radiological safety in the medical application of the ionizing radiation compiled in 11 chapter and 1 annex. The first four chapters are principally dedicated to technical uses in radioprotection, the external and internal irradiation and the biological radiation effects. The radioprotection principles, the individual monitoring techniques, and the radioprotection systems are developed afterwards in the followings three chapters. The second half of the document is dedicated entirely to the medical practices using ionizing radiations, specially to the radioprotection aspects in radiodiagnosis, nuclear medicine and radiotherapy. The final chapter is dedicated to radiological accidents happened worldwide in the field of the medical applications of the ionizing radiations. The annex, about of the regulatory area, established a set of standards, laws, decrees and other force regulations in radiological safety, related in radiodiagnosis, nuclear medicine and radiotherapy

Assessment of health risks from exposure to ionizing radiation

International Nuclear Information System (INIS)

Beebe, G.W.

1982-01-01

Rapid development in the assessment of health risks from exposure to ionizing radiation has produced an impressive array of risk differentials of presumed biologic significance. In the human data these differentials involve: (1) the variety of cancer, especially its size; (2) host factors, especially age; (3) time following exposure; (4) magnitude of dose; and (5) type of radiation. From experimental work we may presume that dose-rate also plays a role, especially for sparsely ionizing radiation. Current research is extending the scope of differentials with respect to these and other variables, including cell type and concomitant environmental risk factors, and testing dose-response models suggested by experimental and theoretical work. As facts to be explained, differentials in risk may lead to hypotheses to be explored experimentally and improve our understanding of how ionizing radiation causes cancer. 74 references

Social trust and ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Meadd, E. [Faculty of Environmental Studies, York University, Toronto, Ontario (Canada)

2002-07-01

The linkages that exist between the environmental risks associated with nuclear energy production (both perceived and real) and the myriad of social and political issues and processes that influence social trust are a current issue in literature, but are not well explored, particularly for the Canadian context. This paper will examine one particular issue and its relationship with social trust: ionizing radiation and public health. Social trust is defined for this paper as including interpersonal trust, but having a much broader focus, extending to public trust in governments, institutions, corporations, and the power elite, and across whole societies. Of particular interest for the nuclear energy issue is how waning social trust may impact the functioning of democratic decision-making processes, particularly those associated with the siting of waste facilities. Social trust is a central issue in the management of environmental risks, particularly those related to high technology; its absence is seen as a major cause of intractable conflict in decisions related to nuclear power generation and waste disposal. Understanding the dynamics of social trust is important if a resolution is to be found to the nuclear waste management debate in Canada, that is, one that involves broad public, or social, support. For instance, what factors cause distrust to emerge, and when distrust emerges, what authorities do members of affected communities seek out for information and support? This paper begins to examine social trust in relation to human health and ionizing radiation, particularly low dose radiation from radioactive wastes resulting from uranium and radium processing activities in Port Hope, Ontario. These activities date back to the 1930s and are of great concern to community members. This paper looks at some of the roots of public concern, for example, scientific uncertainty around whether or not human health is compromised by exposure to low dose ionizing radiation

Social trust and ionizing radiation

International Nuclear Information System (INIS)

Meadd, E.

2002-01-01

The linkages that exist between the environmental risks associated with nuclear energy production (both perceived and real) and the myriad of social and political issues and processes that influence social trust are a current issue in literature, but are not well explored, particularly for the Canadian context. This paper will examine one particular issue and its relationship with social trust: ionizing radiation and public health. Social trust is defined for this paper as including interpersonal trust, but having a much broader focus, extending to public trust in governments, institutions, corporations, and the power elite, and across whole societies. Of particular interest for the nuclear energy issue is how waning social trust may impact the functioning of democratic decision-making processes, particularly those associated with the siting of waste facilities. Social trust is a central issue in the management of environmental risks, particularly those related to high technology; its absence is seen as a major cause of intractable conflict in decisions related to nuclear power generation and waste disposal. Understanding the dynamics of social trust is important if a resolution is to be found to the nuclear waste management debate in Canada, that is, one that involves broad public, or social, support. For instance, what factors cause distrust to emerge, and when distrust emerges, what authorities do members of affected communities seek out for information and support? This paper begins to examine social trust in relation to human health and ionizing radiation, particularly low dose radiation from radioactive wastes resulting from uranium and radium processing activities in Port Hope, Ontario. These activities date back to the 1930s and are of great concern to community members. This paper looks at some of the roots of public concern, for example, scientific uncertainty around whether or not human health is compromised by exposure to low dose ionizing radiation

Annual individual doses for personnel dealing with ionizing radiation sources

International Nuclear Information System (INIS)

Poplavskij, K.K.

1982-01-01

Data on annual individual doses for personnel of national economy enterprises, research institutes, high schools, medical establishments dealing with ionizing radiation sources are presented. It is shown that radiation dose for the personnel constitutes only shares of standards established by sanitary legislation. Numeral values of individual doses of the personnel are determined by the type, character and scope of using ionizing radiation sources

Consultative committee on ionizing radiation: Impact on radionuclide metrology

International Nuclear Information System (INIS)

Karam, L.R.; Ratel, G.

2016-01-01

In response to the CIPM MRA, and to improve radioactivity measurements in the face of advancing technologies, the CIPM's consultative committee on ionizing radiation developed a strategic approach to the realization and validation of measurement traceability for radionuclide metrology. As a consequence, measurement institutions throughout the world have devoted no small effort to establish radionuclide metrology capabilities, supported by active quality management systems and validated through prioritized participation in international comparisons, providing a varied stakeholder community with measurement confidence. - Highlights: • Influence of CIPM MRA on radionuclide metrology at laboratories around the world. • CCRI strategy: to be the “undisputed hub for ionizing radiation global metrology.” • CCRI Strategic Plan stresses importance of measurement confidence for stakeholder. • NMIs increasing role in radionuclide metrology by designating institutions (DIs). • NMIs and DIs establish quality systems; validate capabilities through comparisons.

Cell fusion by ionizing radiation

International Nuclear Information System (INIS)

Khair, M.B.

1993-08-01

The relevance and importance of cell fusion are illustrated by the notion that current interest in this phenomenon is shared by scientists in quite varied disciplines. The diversity of cellular membrane fusion phenomena could provoke one to think that there must be a multitude of mechanisms that can account for such diversity. But, in general, the mechanism for the fusion reaction itself could be very similar in many, or even all, cases. Cell fusion can be induced by several factors such as virus Sendai, polyethylene glycol, electric current and ionizing radiation. This article provides the reader with short view of recent progress in research on cell fusion and gives some explanations about fusion mechanisms. This study shows for the first time, the results of the cell fusion induced by ionizing radiations that we have obtained in our researches and the work performed by other groups. (author). 44 refs

Interactive visual intervention planning in particle accelerator environments with ionizing radiation

International Nuclear Information System (INIS)

Fabry, Thomas

2014-01-01

Radiation is omnipresent. It has many interesting applications: in medicine, where it allows curing and diagnosing patients; in communication, where modern communication systems make use of electromagnetic radiation; and in science, where it is used to discover the structure of materials; to name a few. Physically, radiation is a process in which particles or waves travel through any kind of material, usually air. Radiation can be very energetic, in which case it can break the atoms of ordinary matter (ionization). If this is the case, radiation is called ionizing. It is known that ionizing radiation can be far more harmful to living beings than non-ionizing radiation. In this dissertation, we are concerned with ionizing radiation. Naturally occurring ionizing radiation in the form of radioactivity is a most natural phenomenon. Almost everything is radioactive: there is radiation emerging from the soil, it is in the air, and the whole planet is constantly undergoing streams of energetic cosmic radiation. Since the beginning of the twentieth century, we are also able to artificially create radioactive matter. This has opened a lot of interesting technological opportunities, but has also given a tremendous responsibility to humanity, as the nuclear accidents in Chernobyl and Fukushima, and various accidents in the medical world have made clear. This has led to the elaboration of a radiological protection system. In practice, the radiological protection system is mostly implemented using a methodology that is indicated with the acronym ALARA: As Low As Reasonably Achievable. This methodology consists of justifying, optimizing and limiting the radiation dose received. This methodology is applied in conjunction with the legal limits. The word 'reasonably' means that the optimization of radiation exposure has to be seen in context. The optimization is constrained by the fact that the positive effects of an operation might surpass the negative effects caused by the

Ionizing radiation, antioxidant response and oxidative damage: A meta-analysis

Energy Technology Data Exchange (ETDEWEB)

Einor, D., E-mail: daniel@einor.com [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); Bonisoli-Alquati, A., E-mail: andreabonisoli@gmail.com [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA 70803 (United States); Costantini, D., E-mail: davidcostantini@libero.it [Department of Biology, University of Antwerp, Wilrijk, B-2610, Antwerp (Belgium); Mousseau, T.A., E-mail: mousseau@sc.edu [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); Faculty of Bioscience and Biotechnology, Chubu University, Kasugai (Japan); Møller, A.P., E-mail: anders.moller@u-psud.fr [Laboratoire d' Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, F-91405 Orsay Cedex (France)

2016-04-01

One mechanism proposed as a link between exposure to ionizing radiation and detrimental effects on organisms is oxidative damage. To test this hypothesis, we surveyed the scientific literature on the effects of chronic low-dose ionizing radiation (LDIR) on antioxidant responses and oxidative damage. We found 40 publications and 212 effect sizes for antioxidant responses and 288 effect sizes for effects of oxidative damage. We performed a meta-analysis of signed and unsigned effect sizes. We found large unsigned effects for both categories (0.918 for oxidative damage; 0.973 for antioxidant response). Mean signed effect size weighted by sample size was 0.276 for oxidative damage and − 0.350 for antioxidant defenses, with significant heterogeneity among effects for both categories, implying that ionizing radiation caused small to intermediate increases in oxidative damage and small to intermediate decreases in antioxidant defenses. Our estimates are robust, as shown by very high fail-safe numbers. Species, biological matrix (tissue, blood, sperm) and age predicted the magnitude of effects for oxidative damage as well as antioxidant response. Meta-regression models showed that effect sizes for oxidative damage varied among species and age classes, while effect sizes for antioxidant responses varied among species and biological matrices. Our results are consistent with the description of mechanisms underlying pathological effects of chronic exposure to LDIR. Our results also highlight the importance of resistance to oxidative stress as one possible mechanism associated with variation in species responses to LDIR-contaminated areas. - Highlights: • There is interest in variation in metabolic effects of chronic low-dose ionizing radiation • A random effect meta-analysis of effect sizes of radioactive contamination was performed • We found significant effects of radiation on oxidative damage and antioxidant response • We found significant heterogeneity among

Ionizing radiation decreases human cancer mortality rates

International Nuclear Information System (INIS)

Luckey, T.D.

1997-01-01

Information from nine studies with exposed nuclear workers and military observers of atmospheric bomb explosions confirms the results from animal studies which showed that low doses of ionizing radiation are beneficial. The usual ''healthy worker effect'' was eliminated by using carefully selected control populations. The results from 13 million person-years show the cancer mortality rate of exposed persons is only 65.6% that of carefully selected unexposed controls. This overwhelming evidence makes it politically untenable and morally wrong to withhold public health benefits of low dose irradiation. Safe supplementation of ionizing radiation should become a public health service. (author)

Ionizing radiation-induced metabolic oxidative stress and prolonged cell injury

Science.gov (United States)

Azzam, Edouard I.; Jay-Gerin, Jean-Paul; Pain, Debkumar

2013-01-01

Cellular exposure to ionizing radiation leads to oxidizing events that alter atomic structure through direct interactions of radiation with target macromolecules or via products of water radiolysis. Further, the oxidative damage may spread from the targeted to neighboring, non-targeted bystander cells through redox-modulated intercellular communication mechanisms. To cope with the induced stress and the changes in the redox environment, organisms elicit transient responses at the molecular, cellular and tissue levels to counteract toxic effects of radiation. Metabolic pathways are induced during and shortly after the exposure. Depending on radiation dose, dose-rate and quality, these protective mechanisms may or may not be sufficient to cope with the stress. When the harmful effects exceed those of homeostatic biochemical processes, induced biological changes persist and may be propagated to progeny cells. Physiological levels of reactive oxygen and nitrogen species play critical roles in many cellular functions. In irradiated cells, levels of these reactive species may be increased due to perturbations in oxidative metabolism and chronic inflammatory responses, thereby contributing to the long-term effects of exposure to ionizing radiation on genomic stability. Here, in addition to immediate biological effects of water radiolysis on DNA damage, we also discuss the role of mitochondria in the delayed outcomes of ionization radiation. Defects in mitochondrial functions lead to accelerated aging and numerous pathological conditions. Different types of radiation vary in their linear energy transfer (LET) properties, and we discuss their effects on various aspects of mitochondrial physiology. These include short and long-term in vitro and in vivo effects on mitochondrial DNA, mitochondrial protein import and metabolic and antioxidant enzymes. PMID:22182453

Ionizing radiation sensitivity and the rate of gross chromosomal rearrangement in yeast

International Nuclear Information System (INIS)

Brown, J.A.; Brown, M.

2003-01-01

Full text: Many of the genes conferring resistance to DNA damage in the yeast Saccharomyces cerevisiae have been identified. The systematic deletion of every open reading frame presents the opportunity to make great strides in determining the physiological role of many genes whose function has remained elusive. The ability to discriminate among all of the strains carrying unique non-essential gene deletions in a pool has allowed us to screen for novel genes required for survival to ionizing radiation. Many of these genes have not yet been characterized. A possible role for these genes could be in the initial sensing of the double strand break introduced by ionizing radiation, the cell cycle arrest permitting the cell time for the repair process, or directly in the repair. A consequence of a failure of any of these functions could result in an increase in mutation rate as well the more detrimental gross chromosomal rearrangement (GCR). We tested the hypothesis that any gene which when deleted caused an increase in ionizing radiation sensitivity would also demonstrate an increase in mutation rate and GCR. This turned out not to be the case with many having no significant increase and one in particular which caused a significant decrease in GCR. Data on several of the more intriguing genes will be presented

Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

International Nuclear Information System (INIS)

Sabanero, M.; Flores V, L. L.; Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M.; Castruita D, J. P.; Barbosa S, G.

2015-10-01

Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H 2 O 2 /1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

Mammalian cells exposed to ionizing radiation: structural and biochemical aspects

Energy Technology Data Exchange (ETDEWEB)

Sabanero, M.; Flores V, L. L. [Universidad de Guanajuato, Departamento de Biologia, DCNE, Noria Alta s/n, 36250 Guanajuato, Gto. (Mexico); Azorin V, J. C.; Vallejo, M. A.; Cordova F, T.; Sosa A, M. [Universidad de Guanajuato, Departamento de Ingenieria Fisica, DCI, Loma del Bosque 103, Col. Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Castruita D, J. P. [Universidad de Guadalajara, Departamento de Ecologia, CUCBA, Las Agujas, 45100 Zapopan, Jalisco (Mexico); Barbosa S, G., E-mail: myrna.sabanero@gmail.com [Universidad de Guanajuato, Departamento de Ciencias Medicas, DCS, 20 de Enero No. 929, Col. Obregon, 37000 Leon, Guanajuato (Mexico)

2015-10-15

Acute or chronic exposure to ionizing radiation is a factor that may be hazardous to health. It has been reported that exposure to low doses of radiation (less than 50 mSv / year) and subsequently exposure to high doses have greater effects in people. However, it is unknown molecular and biochemical level alteration. This study, analyzes the susceptibility of a biological system (HeLa Atcc CCL-2 human cervix cancer cell line) to ionizing radiation (6 and 60 mSv/ 90). Our evaluate multiple variables such as: total protein profile, mitochondrial metabolic activity (XTT assay), cell viability (Trypan blue exclusion assay), cytoskeleton (actin micro filaments), nuclei (D API), genomic DNA. The results indicate, that cells exposed to ionizing radiation structurally show alterations in nuclear phenotype and aneuploidy, further disruption in the tight junctions and consequently on the distribution of actin micro filaments. Similar alterations were observed in cells treated with a genotoxic agent (200μM H{sub 2}O{sub 2}/1 h). In conclusion, this multi-criteria assessment enables precise comparisons of the effects of radiation between any biological systems. However, it is necessary to determine stress markers for integration of the effects of ionizing radiation. (Author)

Ionizing radiation from tobacco

International Nuclear Information System (INIS)

Westin, J.B.

1987-01-01

Accidents at nuclear power facilities seem inevitably to bring in their wake a great deal of concern on the part of both the lay and medical communities. Relatively little attention, however, is given to what may be the largest single worldwide source of effectively carcinogenic ionizing radiation: tobacco. The risk of cancer deaths from the Chernobyl disaster are tobacco smoke is discussed

Ionizing radiation and non-ionizing radiation in educational environment

International Nuclear Information System (INIS)

Matsuzawa, Takao; Otsubo, Tomonobu; Ikke, Satoshi; Taguchi, Noriko; Takeda, Rie

2005-01-01

By chance, we measured gamma dose rates in our school, and around the JCO Tokai Plant during the criticality on September 30 in 1999, with our GM survey meter. At that time, we made sure to estimate the position of criticality reaction (source point), and the source intensity of criticality reaction, with our own data, measured along the public roads, route 6 and local road 62. The intensity of gamma dose rates along the road was analyzed as Lorentz functions. At the time, there were no environmental radiation data about the criticality accident, or all the data, especially radioactivity and dose rates around the JCO Tokai Plant, was closed to the public. Recently, we are interested in the intensity of non-ionizing radiation, especially extremely low frequency (ELF) magnetic field, and electric field, in our environment. We adopted the same method to analyze the source position and source intensity of an ELF magnetic field and electric behind a wall. (author)

Relationship between autophagy and apoptosis of MCF-7 cells induced by ionizing radiation

International Nuclear Information System (INIS)

Qi Yali; Zhang Zhenyu; Wang Hongyan; Li Jinhua; Gong Shouliang

2009-01-01

Objective: To detect the inhibitory effects of ionizing radiation combined with autophagy and apoptosis inhibitors and inducers on the proliferation of human breast cancer cell line. Methods: MTT and flow cytometry (FCM) were used to detect the surviving and proliferation of MCF-7 cells, which were under 0, 2, 4, 8 and 10 Gy X-ray radiation and different dealing methods 4 Gy, 4 Gy + 3-MA, 4 Gy + rapamycin, 4 Gy + z-VAD-fmk, and the relationship of dose-effects and time-effects was analyzed. Results: With the increase of irradiation doses (4, 8 and 10 Gy) and the elongation of irradiation time (48 and 72 h), the inhibitory rates of the proliferation of breast cancer cells were increased, there were significant differences between various groups (P<0.05 or P<0.01). The inhibitory rates of the proliferation of breast cancer cells in 4 Gy+3-MA or 4 Gy+ z-VAD-fmk groups were significantly different from those in 4Gy+rapamycin group (P<0.05 or P<0.01), and there were significant differences after treated for 24, 48 and 72 h between various groups (P<0.05 or P<0.01). Conclusion: Ionizing radiation in combination with autophagy inducer could induced the autophagy in human breast cancer cells and promote the apoptosis; the ionizing radiation in combination with autophagy inhibitor or apoptosis inhibitor could inhibit the apoptosis. Thus, ionizing radiation can induce the autophagy in human breast cancer cells, and promote the apoptosis. (authors)

Comparative study of the use of non-ionizing and ionizing radiation in the cure of epoxy resin: microwave versus electron electron

Energy Technology Data Exchange (ETDEWEB)

Kersting, Daniel, E-mail: daniel.kersting@usp.br [Centro Tecnologico da Marinha em Sao Paulo (CTMSP/USP), Sao Paulo, SP (Brazil); Wiebeck, Helio, E-mail: hwiebeck@usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica; Marinucci, Gerson; Silva, Leonardo G.A. e, E-mail: marinuci@ipen.br, E-mail: gasilva@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

Several processes for curing epoxy resins were developed over the years. Two methods are discussed in this paper, in order to present the main advantages and disadvantages of using microwave radiation (non-ionizing radiation) and electron beam radiation (ionizing radiation). The microwave radiation is a non-ionizing radiation, with great power of penetration and transfer of heat in microwave absorbing materials, or materials with microwave absorbing fillers. The frequency usually used in research and development is 2.45 GHz, the same available in commercial equipment. The microwave effect provides increase on the collision velocity between the reactant which, combined with energy absorbed by the reaction system, accelerates the curing reaction. None modifications in the epoxy system are required to use microwave heating for the curing process.On the other hand, the electron beam is a form of ionizing radiation in which the high energy electrons have the ability to interact with the irradiated material and produce ions, free radicals, and molecules in excited state, which can be used to initiate and propagate a polymerization. Specific initiators are necessary for an effective cure of the resin. In this study, a DGEBA epoxy resin with initiators based on anhydride and amine was used under the same conditions indicated by the manufacturer. The curing of the catalyzed system was performed in a domestic microwave oven adapted for laboratory use. The degradation and glass transition temperatures were evaluated by thermal analysis techniques. For comparative purposes, it was used data available in the literature for electron beam irradiation. (author)

Comparative study of the use of non-ionizing and ionizing radiation in the cure of epoxy resin: microwave versus electron electron

International Nuclear Information System (INIS)

Kersting, Daniel; Wiebeck, Helio

2013-01-01

Several processes for curing epoxy resins were developed over the years. Two methods are discussed in this paper, in order to present the main advantages and disadvantages of using microwave radiation (non-ionizing radiation) and electron beam radiation (ionizing radiation). The microwave radiation is a non-ionizing radiation, with great power of penetration and transfer of heat in microwave absorbing materials, or materials with microwave absorbing fillers. The frequency usually used in research and development is 2.45 GHz, the same available in commercial equipment. The microwave effect provides increase on the collision velocity between the reactant which, combined with energy absorbed by the reaction system, accelerates the curing reaction. None modifications in the epoxy system are required to use microwave heating for the curing process.On the other hand, the electron beam is a form of ionizing radiation in which the high energy electrons have the ability to interact with the irradiated material and produce ions, free radicals, and molecules in excited state, which can be used to initiate and propagate a polymerization. Specific initiators are necessary for an effective cure of the resin. In this study, a DGEBA epoxy resin with initiators based on anhydride and amine was used under the same conditions indicated by the manufacturer. The curing of the catalyzed system was performed in a domestic microwave oven adapted for laboratory use. The degradation and glass transition temperatures were evaluated by thermal analysis techniques. For comparative purposes, it was used data available in the literature for electron beam irradiation. (author)

[Use of ionizing radiation sources in metallurgy: risk assessment].

Science.gov (United States)

Giugni, U

2012-01-01

Use of ionizing radiation sources in the metallurgical industry: risk assessment. Radioactive sources and fixed or mobile X-ray equipment are used for both process and quality control. The use of ionizing radiation sources requires careful risk assessment. The text lists the characteristics of the sources and the legal requirements, and contains a description of the documentation required and the methods used for risk assessment. It describes how to estimate the doses to operators and the relevant classification criteria used for the purpose of radiation protection. Training programs must be organized in close collaboration between the radiation protection expert and the occupational physician.

Administration of ionizing radiation to human subjects in medical research

International Nuclear Information System (INIS)

1985-01-01

Any administration of ionizing radiation to human subjects for the purposes of diagnostic or therapeutic research involving either irradiation or the administration of radionuclides, should be undertaken only after approval by an institutional ethics committee. The ethics committee should obtain advice from a person experienced in radiation protection before granting approval. The research proposal must conform to regulatory requirements relating to the use of ionizing radiation

Scientific colloquium on medical supervision of workers exposed to ionizing and non ionizing radiations

International Nuclear Information System (INIS)

1975-01-01

The general principles of medical surveillance for workers exposed to ionizing radiation were defined in the Euratom Basic Standards in 1959. These principles, which are in accordance with the early IGRP publications, have been adopted by the national authorities and implemented without difficulty. However, because of the forthcoming publication of the revised Basic Standards- in accordance with recent IGRP recommendations, the Commission decided to organize a meeting of doctors responsible for the medical surveillance of workers exposed to ionizing radiation in order to disseminate as widely as possible the results of experience gained in the field of radiological protection and to pinpoint the practical difficulties which might arise when the principles were applied. The Commission also considered it important to inform doctors specializing in radiological protection about the principles to be followed by those responsible for the health protection of workers exposed to non-ionizing radiation, particularly microwaves and Laser beams. The complete text of each report in the original language is given in this volume

Suppression of E. multilocularis hydatid cysts after ionizing radiation exposure.

Directory of Open Access Journals (Sweden)

Xin Zhou

Full Text Available BACKGROUND: Heavy-ion therapy has an advantage over conventional radiotherapy due to its superb biological effectiveness and dose conformity in cancer therapy. It could be a potential alternate approach for hydatid cyst treatment. However, there is no information currently available on the cellular and molecular basis for heavy-ion irradiation induced cell death in cystic echinococcosis. METHODODOLOGY/PRINCIPAL FINDINGS: LD50 was scored by protoscolex death. Cellular and ultrastructural changes within the parasite were studied by light and electron microscopy, mitochondrial DNA (mtDNA damage and copy number were measured by QPCR, and apoptosis was determined by caspase 3 expression and caspase 3 activity. Ionizing radiation induced sparse cytoplasm, disorganized and clumped organelles, large vacuoles and devoid of villi. The initial mtDNA damage caused by ionizing radiation increased in a dose-dependent manner. The kinetic of DNA repair was slower after carbon-ion radiation than that after X-rays radiation. High dose carbon-ion radiation caused irreversible mtDNA degradation. Cysts apoptosis was pronounced after radiation. Carbon-ion radiation was more effective to suppress hydatid cysts than X-rays. CONCLUSIONS: These studies provide a framework to the evaluation of attenuation effect of heavy-ion radiation on cystic echinococcosis in vitro. Carbon-ion radiation is more effective to suppress E. multilocularis than X-rays.

Occupational Diseases Caused by Ionizing Radiation in Poland, 1971-2006

International Nuclear Information System (INIS)

Wilczynska, U.; Szeszenia-Dabrowska, N.

2008-01-01

The whole spectrum of disorders of the hematopoietic tissue, eye and skin induced by ionizing radiation covers complex pathologies termed as a postirradiation syndrome, as well as various malignancies. The aim of this work is to present the data on incidence of occupational diseases with ionizing radiation as a causative agent. The work is based on the data compiled from 'Occupational Diseases Reporting Forms' for the years 1971-2006 collected in the Central Register of Occupational Diseases. The incidence of certified occupational diseases with ionizing radiation as a causative agent is expressed in absolute numbers and the rate per 100 000 employees. The data comprise information on disease entities, gender, age, exposure duration and the branch of national economy. In total, 599 diseases (0.2% of all occupational diseases) were diagnosed as those induced by ionizing radiation. Annual incidence rates per 100 000 employees fell within the range of 0.0-0.7. Miners formed the major (51.9%) occupational group affected by ionizing radiation. They were followed by health care (34.3%) and construction (6.4%) workers. Cancers made over 50% of pathologies located at 28 sites. These included cancers of lung (59.2%), skin (10.0%) and hematopoietic tissue (8.7%). Almost all (99.35) diseases recorded in the mining industry were cancers. Non-cancer diseases were more frequent in health care workers, among them postradiation cataract occupied the first place. A great deal of reported cancer sites give rise to controversy in terms of the cause-effect association with ionizing radiation exposure and also due to incomplete data on exposure duration. Postradiation cancers among health care workers have not been registered over recent years, which means that occupational exposure surveillance carried out for many years proves to be effective. Distant effects of exposure to ionizing radiation, revealed in workers of no longer existing uranium mine, appeared to be a particular problem

'K' contribution to the biological effect of ionizing radiations

International Nuclear Information System (INIS)

Boissiere, Arnaud

2004-01-01

The aim of this work is to determine the importance of 'K' ionizations on DNA as critical physical events initiating the biological effects of ionizing radiation, in particular in human cells. Ultra-soft X-rays are used as a probe of core ionization events. A decisive test consists in comparing the biological effects at 250 eV and 350 eV (before and after the carbon K - threshold). The results show a sharp increase of the biological efficiency for both cellular inactivation and chromosomal exchange aberration above the carbon K-threshold, correlated with the one of core events occurring in DNA atoms. The heavy ion irradiation displays again the paradoxical behaviour of cellular inactivation cross sections as a function of LET. Finally, the 'K' event contribution to cellular inactivation of usual low LET radiation is estimated to be about 75%. (author) [fr

Assessment of dose level of ionizing radiation in army scrap

International Nuclear Information System (INIS)

Abdel Hamid, S. M.

2010-12-01

Radiation protection is the science of protecting people and the environment from the harmful effects of ionizing radiation, which includes both particle radiation and high energy radiation. Ionizing radiation is widely used in industry and medicine. Any human activity of nuclear technologies should be linked to the foundation of scientific methodology and baseline radiation culture to avoid risk of radiation and should be working with radioactive materials and expertise to understand, control practices in order to avoid risks that could cause harm to human and environment. The study was conducted in warehouses and building of Sudan air force Khartoum basic air force during September 2010. The goal of this study to estimate the radiation dose and measurement of radioactive contamination of aircraft scrap equipment and increase the culture of radiological safety as well as the concept of radiation protection. The results showed that there is no pollution observed in the contents of the aircraft and the spire part stores outside, levels of radiation dose for the all contents of the aircraft and spire part within the excitable level, except temperature sensors estimated radiation dose about 43 μSv/h outside of the shielding and 12 μSv/h inside the shielding that exceeded the internationally recommended dose level. One of the most important of the identification of eighteen (18) radiation sources used in temperature and fuel level sensors. These are separated from the scrap, collected and stored in safe place. (Author)

Genetic and somatic effects of ionizing radiation

International Nuclear Information System (INIS)

1986-01-01

This is the ninth substantive report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) to the General Assembly. This report contains reviews on three special topics in the field of biological effects of ionizing radiation that are among those presently under consideration by the Committee: genetic effects of radiation, dose-response relationships for radiation-induced cancer and biological effects of pre-natal irradiation

Mortality from diseases other than cancer following low doses of ionizing radiation

DEFF Research Database (Denmark)

Vrijheid, M; Cardis, E; Ashmore, P

2007-01-01

BACKGROUND: Ionizing radiation at very high (radio-therapeutic) dose levels can cause diseases other than cancer, particularly heart diseases. There is increasing evidence that doses of the order of a few sievert (Sv) may also increase the risk of non-cancer diseases. It is not known, however......, whether such effects also occur following the lower doses and dose rates of public health concern. METHODS: We used data from an international (15-country) nuclear workers cohort study to evaluate whether mortality from diseases other than cancer is related to low doses of external ionizing radiation....... Analyses included 275 312 workers with adequate information on socioeconomic status, over 4 million person-years of follow-up and an average cumulative radiation dose of 20.7 mSv; 11 255 workers had died of non-cancer diseases. RESULTS: The excess relative risk (ERR) per Sv was 0.24 [95% CI (confidence...

Improved capacity in ionizing radiation metrology at SANAEM

International Nuclear Information System (INIS)

Yucel, U.

2014-01-01

Full text : Turkey is planning to build nuclear power plants in the south and north coasts to supply the ever-increasing energy demand. The nuclear power plants based on old soviet technology in Armenia and Bulgaria close to Turkey's borders also makes constant monitoring of environmental radioactivity extremely important due to public health and environment contamination concerns. Radiation Metrology Division at SANAEM has been established in 2012 to provide uniformity and reliability of the measurements in the field of ionizing radiation metrology by R and D studies and by constituting, developing, keeping and extending internationally accepted reference measurement standards and techniques

Non-targeted and delayed effects of exposure to ionizing radiation

International Nuclear Information System (INIS)

Zuo Yahui; Tong Jian

2007-01-01

Non-targeted and delayed effects are relative phenomena in cellular responses to ionizing radiation. These effects (bystander effects, genomic instability and adaptive responses) have been studied most extensively for radiation exposures. It is clear that adaptive responses, bystander effects and genomic instability will play an important role in the low dose-response to radiation. This review will provide a synthesis of the known, and proposed interrelationships amongst low-dose cellular responses to radiation, It also will examine the potential biological significance of non-targeted and delayed effects of exposure to ionizing radiation. (authors)

The effects on populations of exposure to low levels of ionizing radiation. Report of the Advisory Committee on the Biological Effects of Ionizing Radiations

Energy Technology Data Exchange (ETDEWEB)

NONE

1972-11-01

In the summer of 1970, the Federal Radiation Council (whose activities have since been transferred to the Radiation Office of the EPA) asked the National Academy of Sciences for information relevant to an evaluation of present radiation protection guides. This report is in response to that request. It presents a summary and analysis, by members of the Advisory Committee on the Biological Effects of Ionizing Radiations and its subcommittees, of current knowledge relating to risks from exposure to ionizing radiation. In many respects, the report is a sequel to the reports of the Committee on the Biological Effects of Atomic Radiation, published by the NAS-NRC from 1956 to 1961.

The effects on populations of exposure to low levels of ionizing radiation. Report of the Advisory Committee on the Biological Effects of Ionizing Radiations

International Nuclear Information System (INIS)

1972-11-01

In the summer of 1970, the Federal Radiation Council (whose activities have since been transferred to the Radiation Office of the EPA) asked the National Academy of Sciences for information relevant to an evaluation of present radiation protection guides. This report is in response to that request. It presents a summary and analysis, by members of the Advisory Committee on the Biological Effects of Ionizing Radiations and its subcommittees, of current knowledge relating to risks from exposure to ionizing radiation. In many respects, the report is a sequel to the reports of the Committee on the Biological Effects of Atomic Radiation, published by the NAS-NRC from 1956 to 1961

Si no. 43 of 1991 - European Communities (ionizing radiation) regulations, 1991

International Nuclear Information System (INIS)

1991-01-01

These Regulations entered into force on 5 April 1991 and repeal the Factories Ionizing Radiations (Sealed Sources) Regulations, 1972 and the Factories Ionizing Radiations (Unsealed Sources) Regulations, 1972. They were made in implementation of the European Communities' Council Directive 80/836 Euratom of 15 July 1980, as amended by Council Directive 84/467 Euratom of 3 September 1984, laying down the basic safety standards for the health protection of the general public and workers against the dangers of ionizing radiation. They also complement the Nuclear Energy (General Control of Fissile Fuels, Radioactive Substances and Irradiation Apparatus) Order, 1977 with regard to licensing requirements. They apply to the production, processing, handling, use, transport, storage, etc. of natural and artificial radioactive substances and to any other activity which involves a hazard arising from ionizing radiation. (NEA) [fr

Wound trauma alters ionizing radiation dose assessment

Directory of Open Access Journals (Sweden)

Kiang Juliann G

2012-06-01

Full Text Available Abstract Background Wounding following whole-body γ-irradiation (radiation combined injury, RCI increases mortality. Wounding-induced increases in radiation mortality are triggered by sustained activation of inducible nitric oxide synthase pathways, persistent alteration of cytokine homeostasis, and increased susceptibility to bacterial infection. Among these factors, cytokines along with other biomarkers have been adopted for biodosimetric evaluation and assessment of radiation dose and injury. Therefore, wounding could complicate biodosimetric assessments. Results In this report, such confounding effects were addressed. Mice were given 60Co γ-photon radiation followed by skin wounding. Wound trauma exacerbated radiation-induced mortality, body-weight loss, and wound healing. Analyses of DNA damage in bone-marrow cells and peripheral blood mononuclear cells (PBMCs, changes in hematology and cytokine profiles, and fundamental clinical signs were evaluated. Early biomarkers (1 d after RCI vs. irradiation alone included significant decreases in survivin expression in bone marrow cells, enhanced increases in γ-H2AX formation in Lin+ bone marrow cells, enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood, and concomitant decreases in γ-H2AX formation in PBMCs and decreases in numbers of splenocytes, lymphocytes, and neutrophils. Intermediate biomarkers (7 – 10 d after RCI included continuously decreased γ-H2AX formation in PBMC and enhanced increases in IL-1β, IL-6, IL-8, and G-CSF concentrations in blood. The clinical signs evaluated after RCI were increased water consumption, decreased body weight, and decreased wound healing rate and survival rate. Late clinical signs (30 d after RCI included poor survival and wound healing. Conclusion Results suggest that confounding factors such as wounding alters ionizing radiation dose assessment and agents inhibiting these responses may prove therapeutic for radiation combined

Ionizing radiation sources used in medical applications in Brazil

International Nuclear Information System (INIS)

Araujo, A.M.C.; Carlos, M.T.; Cruz, L.R.F.; Domingues, C.; Farias, J.T.; Ferreira, R.; Figueiredo, L.; Peixoto, J.E.; Oliveira, S.M.V.; Drexler, G.

1991-02-01

Preliminary data about ionizing radiation sources used in medical applications and obtained through a national programme by IRD/CNEN together with Brazilian health authorities are presented. The data presentation follows, as close as possible, recommendations given by the United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR). This programme has two main aims: First: to contribute for research in the field of ionizing radiation effects and risks including information about equipment quality control and procedures adopted by professionals working in Radiation Medicine. Second: to investigate the radiation protection status in Brazil, in order to give assistance to Brazilian health authorities for planning regional radiation programmes and training programmes for medical staffs. (F.E.). 13 refs, 19 figs, 34 tabs

Ionizing-radiation warning - Supplementary symbol

International Nuclear Information System (INIS)

2007-01-01

This International Standard specifies the symbol to warn of the presence of a dangerous level of ionizing radiation from a high-level sealed radioactive source that can cause death or serious injury if handled carelessly. This symbol is not intended to replace the basic ionizing radiation symbol [ISO 361, ISO 7010:2003, Table 1 (Reference number W003)], but to supplement it by providing further information on the danger associated with the source and the necessity for untrained or uninformed members of the public to stay away from it. This symbol is recommended for use with International Atomic Energy Agency (IAEA) Category 1, 2, and 3 sealed radioactive sources. These sources are defined by the IAEA as having the ability to cause death or serious injuries. The paper informs about scope, shape, proportions and colour of the symbol, and application of the symbol. An annex provides the technical specifications of the symbol

Trans-generational effects induced by alpha and gamma ionizing radiations at Daphnia magna

International Nuclear Information System (INIS)

Parisot, Florian

2015-01-01

Anthropogenic activities related to the nuclear industry contribute to continuous discharges of radionuclides into terrestrial and aquatic ecosystems. Over the past decades, the ecological risk of ionizing radiation has become a growing public, regulatory and scientific concern for ecosystems protection. Until recently, only few studies focus on exposure situations at low doses of irradiation, although these situations are representative of realistic environmental conditions. Understanding how ionizing radiation affects species over several generations and at various levels of biological organization is a major research goal in radioecology. The aim of this PhD was to bring new knowledge on the effects of ionizing radiation during a multi-generational expose of the aquatic invertebrate, Daphnia magna. A two-step strategy was implemented. First, an external gamma radiation at environmentally relevant dose rates was performed on D. magna over three successive generations (F0, F1 and F2). The objective of this experiment was to examine whether low dose rates of radiation induced increasing effects on survival, growth and reproduction of daphnids over generations and to test a possible accumulation and transmission of DNA alterations from adults to offspring. Results showed an accumulation and a transmission of DNA alterations over generations, together with an increase in effect severity on growth and reproduction from generation F0 to generation F2. Transiently more efficient DNA repair leading to some recovery at the organism level was suggested in generation F1. Second, data from the external gamma irradiation and those from an earlier study of internal alpha contamination were analyzed with DEBtox models (Dynamic Energy Budget applied to toxicology), to identify and compare the causes of the trans-generational increase in effect severity between the two types of radiation. In each case, two distinct metabolic modes of action were necessary to explain effects on

Origin of irradiations by ionizing radiations

International Nuclear Information System (INIS)

Metivier, H.

1998-01-01

Irradiations by ionizing radiations proceed from two main sources: the natural radiations from the environment and the sources of 'human' origin, i.e. linked with modern technology. In most countries the irradiation by natural sources remains the most important. The irradiations for medical purposes comes in second position and depends on the degree of technological evolution of the country, and in the last position are the irradiations linked with nuclear industry. The inventory of these irradiations is regularly updated by the Scientific Committee of the United Nations for the study of ionizing radiation effects (UNSCEAR). In France the mean individual irradiation due to natural radioactivity is of 2 mSv per year of efficient dose and can vary with a factor 3 from one region to the other. Irradiation of medical diagnosis origin is of about 1 mSv per year. This paper presents successively: the natural irradiation sources (cosmic radiation, cosmic rays and cosmogenic radionuclides, the Earth's radiations, primary radionuclides and radon), the natural sources modified by the technology (extraction industries, fossil fuels and phosphated ores, aerial transports and space activities, consumer products), the irradiation sources of technological origin (nuclear weapons, electric power production, major accidents, occupational irradiations), and the medical irradiations (diagnosis techniques, radiology, nuclear medicine and therapeutic uses). (J.S.)

Ionizing radiation in medical education in the National University of Cuyo

International Nuclear Information System (INIS)

Lopez Vernengo, Andrea B.

2009-01-01

Medical irradiations constitute the most important contribution to the human exposure to ionizing radiations of artificial origin. The world-wide statistics indicate an increasing tendency in the annual number of these practices based on the development of new techniques of diagnosis by images, the application of new drugs labeled with diverse isotopes and novel advances in cancer treatments. Due to this widespread use, Radiation Protection (RP) has become an excellent subject for scientific societies and regulating organisms. In this sense, most of the European countries have implemented plans of action for the radiological safety of the patient. An example is the guide RP/116 reported by the European Commission in the year 2000, which recommends including a course about RP in the study programs of Schools of Medicine and Dentistry. Consequently, the general purpose of this research project was to critically describe and to analyze the present situation of educational contents referred to the use of ionizing radiations in the Career of Medicine of the National University of Cuyo. The main results show that there is no curricular subject or area of study which includes in its syllabus minimum compulsory contents about RP or basic knowledge about Radiation Physics. In addition, RP and environmental topics related to the use of ionizing radiations in Medicine are not developed according to the 4 recommendations published by specialized International Organisms. Considering that many methods of diagnosis by images use ionizing radiations, it is suggested that that the curriculum of the Medical Career include contents related to this issue. The aim is to incorporate the culture of RP in the formative process of future professionals and, consequently, to reduce the execution of non-justified practices that threaten both individual and environmental health. (authors) [es

Ionizing radiation and water reuse

International Nuclear Information System (INIS)

Borrely, Sueli Ivone; Sampa, Maria Helena de Oliveira; Oikawa, Hiroshi; Silveira, Carlos Gaia da; Duarte, Celina Lopes; Cherbakian, Eloisa Helena

2002-01-01

The aim of the present paper is to point out the possibility of including ionizing radiation for wastewater treatment and reuse. Radiation processing is an efficient technology which can be useful for water reuse once the process can reduce not only the biological contamination but also organic substances, promoting an important acute toxicity removal from aquatic resources. Final secondary effluents from three different wastewater treatment plant were submitted to electron beam radiation and the process efficacy was evaluated. Concerning disinfection, relatively low radiation doses (2,0 - 4,0 kGy) accounted for 4 to 6 cycle log reduction for total coliforms. When radiation was applied for general wastewater improvement related to the chemical contamination, radiation process reduced from 78% up to 100% the total acute toxicity, measured for crustaceans, D. similis, and for V. fiscehri bacteria. (author)

Detoxification of snake venom using ionizing radiation

International Nuclear Information System (INIS)

Rogero, J.R.; Nascimento, N.

1995-01-01

It is generally recognized that energy absorbed by ionizing radiation (gamma rays) can inactivate biological material in tow ways. A direct effects occurs when the primary event, i.e., ionization, is produced in the molecule itself. This is the case when a compound is irradiated in dry state. When a compound is irradiated in a solution, the indirect effect joins the direct. Since water is the most abundant constituent of biological material, it is important to consider the species produced by excitation and ionization of water itself, and the reaction of these species with the target molecules of biological importance. This indirect effect results from the reactions among the studied molecules and the products of radiation interaction with water or other solvents. Highly reactive compounds, the so-called free radicals, which are formed many reactions among themselves, with the dissolved gas, and with other molecules in the solution. With water, the excitation is less important than ionization which is followed within picosecond by the formation of free hydroxyl radicals and hydrated electrons. Alexander and Hamilton showed that irradiation of proteins has revealed damage to aminoacid side chains, production of new groups, splitting of peptide bonds and formation of intramolecular and intermolecular cross-links. With these results it would be possible to use ionizing radiation to change those proteins molecules in order to improve some of their properties according to the necessity. On the other hand, it is recognized that venoms in general are poorly immunogenic, yet fairly toxic. This cause problems because serotherapy is the treatment of choice in snakebite envenomations, and horse antivenom availability is dependent upon. (author)

Ionizing and Nonionizing Radiation Protection. Module SH-35. Safety and Health.

Science.gov (United States)

Center for Occupational Research and Development, Inc., Waco, TX.

This student module on ionizing and nonionizing radiation protection is one of 50 modules concerned with job safety and health. This module describes various types of ionizing and nonionizing radiation, and the situations in the workplace where potential hazards from radiation may exist. Following the introduction, 13 objectives (each keyed to a…

Biopositive Effects of Ionizing Radiation?

International Nuclear Information System (INIS)

Broda, E.

1972-01-01

This paper was written for a talk given by E. Broda in Vienna for an event organised by the chemical physical society, the Austrian biochemical society and the Austrian biophysical society in December 1972. In this paper Broda analyses the question of biopositive effects of ionizing radiation. (nowak)

The value of the photoreactivable component in E. coli Bsub(s-1) cells exposed to densely and sparsely ionizing radiations

International Nuclear Information System (INIS)

Myasnik, M.N.; Morozov, I.I.; Petin, V.G.

1980-01-01

The dependence of the photoreactivation effect in E coli Bsub(s-1) cells on LET and energy of sparsely ionizing radiation was studied. The photoreactivation was shown to be absent after densely ionizing radiation (α-particles of 239 Pu; fast neutron Esub(n) = 0.85 MeV) and after sparsely ionizing radiation with energies below 200 keV. In those cases where photoreactivation took place, the photoreactivable sector was found to increase with the voltage of the radiation. (author)

Procedure to evaluate the ionizing radiation influence over LED and magnetic induction lamps

International Nuclear Information System (INIS)

Oliveira, Otavio Luis de; Menzel, Silvio Carlos; Ribas, Jacinto Oliveira

2015-01-01

The goal of this paper is to present a methodology to evaluate the ionizing radiation influence over Lighting Emitting Diode (LED) and Magnetic Induction (MI) lamps as they use a lot of electronic in their power supply. Considering they have a huge lifetime it is interesting to apply this technology into environments under ionizing radiation, such as a nuclear facility. Thus, it is possible to increase the period between two consecutive maintenance, reduce the repair and global maintenance costs and reduce the operational personnel exposure to ionizing radiation. In this context it is going to be presented a scheme to select different LED and MI lamps available in the Brazilian market, a methodology to irradiate several lamp samples according various radiation levels that can be found in the facilities and the electrical and photometric evaluation to be performed. Considering this methodology it will be possible to analyze the lamps capacity to withstand ionizing radiation, under regular operating conditions of the facilities and its effects in the performance and lifetime of the selected lamps. Thus, the procedures suggested in this work can be used as a guide to perform experiments and analysis to find specific lamps that can reduce the global maintenance costs and the personnel exposure. Hereafter, several lamps are going to be acquired and the tests performed, according the procedures here described. (author)

Procedure to evaluate the ionizing radiation influence over LED and magnetic induction lamps

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Otavio Luis de; Menzel, Silvio Carlos, E-mail: otavioluis@ipen.br, E-mail: scmenzel@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (CEN/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear; Ribas, Jacinto Oliveira, E-mail: jacinto@eletronuclear.gov.br [Eletrobras Termonuclear S.A. (ELETRONUCLEAR), Angra dos Reis, RJ (Brazil). Gerencia de Eletrica e Instrumentacao

2015-07-01

The goal of this paper is to present a methodology to evaluate the ionizing radiation influence over Lighting Emitting Diode (LED) and Magnetic Induction (MI) lamps as they use a lot of electronic in their power supply. Considering they have a huge lifetime it is interesting to apply this technology into environments under ionizing radiation, such as a nuclear facility. Thus, it is possible to increase the period between two consecutive maintenance, reduce the repair and global maintenance costs and reduce the operational personnel exposure to ionizing radiation. In this context it is going to be presented a scheme to select different LED and MI lamps available in the Brazilian market, a methodology to irradiate several lamp samples according various radiation levels that can be found in the facilities and the electrical and photometric evaluation to be performed. Considering this methodology it will be possible to analyze the lamps capacity to withstand ionizing radiation, under regular operating conditions of the facilities and its effects in the performance and lifetime of the selected lamps. Thus, the procedures suggested in this work can be used as a guide to perform experiments and analysis to find specific lamps that can reduce the global maintenance costs and the personnel exposure. Hereafter, several lamps are going to be acquired and the tests performed, according the procedures here described. (author)

Code of practice : safe use of ionizing radiation

International Nuclear Information System (INIS)

1988-07-01

Ionizing radiation is used extensively in the field of scientific research. The risk of uncontrolled exposure to both the worker and the environment is ever present. The purpose of this Code is to set out practices considered by the CSIRO Health and Safety Committee to be appropriate for CSIRO staff and, if followed, they will result in appropriate protection for research staff and the environment. The Code does not cover sources of non-ionizing radiation such as microwave ovens, RF generators and laser sources

measurement of indoor background ionizing radiation in some

African Journals Online (AJOL)

Administrator

Measurement of the background ionizing radiation profile within the. Chemistry Research Laboratory and Physics Laboratory III all of the. University of Jos and their immediate neighbourhood were carried out. These science laboratories also harbour a number of active radiation sources. The radiation levels were measured ...

[Dose rate-dependent cellular and molecular effects of ionizing radiation].

Science.gov (United States)

Przybyszewski, Waldemar M; Wideł, Maria; Szurko, Agnieszka; Maniakowski, Zbigniew

2008-09-11

The aim of radiation therapy is to kill tumor cells while minimizing damage to normal cells. The ultimate effect of radiation can be apoptotic or necrotic cell death as well as cytogenetic damage resulting in genetic instability and/or cell death. The destructive effects of radiation arise from direct and indirect ionization events leading to peroxidation of macromolecules, especially those present in lipid-rich membrane structures as well as chromatin lipids. Lipid peroxidative end-products may damage DNA and proteins. A characteristic feature of radiation-induced peroxidation is an inverse dose-rate effect (IDRE), defined as an increase in the degree of oxidation(at constant absorbed dose) accompanying a lower dose rate. On the other hand, a low dose rate can lead to the accumulation of cells in G2, the radiosensitive phase of the cell cycle since cell cycle control points are not sensitive to low dose rates. Radiation dose rate may potentially be the main factor improving radiotherapy efficacy as well as affecting the intensity of normal tissue and whole-body side effects. A better understanding of dose rate-dependent biological effects may lead to improved therapeutic intervention and limit normal tissue reaction. The study reviews basic biological effects that depend on the dose rate of ionizing radiation.

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)

The effects of ionizing radiation on man

International Nuclear Information System (INIS)

Watson, G.M.

1975-08-01

This paper describes the major effects of ionizing radiation on man and the relationship between such effects and radiation dose, with the conclusion that standards of radiological safety must be based on the carcinogenetic and mutagenic properties of ionizing radiation. Man is exposed to radiation from natural sources and from man-made sources. Exposure from the latter should be regulated but, since there is little observational or experimental evidence for predicting the effects of the very small doses likely to be required for adequate standards of safety, it is necessary to infer them from what is seen at high doses. Because the formal relationship between dose and effect is not fully understood, simplifying assumptions are necessary to estimate the effects of low doses. Two such assumptions are conventionally used; that there is a linear relationship between dose and effect at all levels of dose, and that the rate at which a dose of radiation is given does not alter the magnitude of the effect. These assumptions are thought to be conservative, that is they will not lead to an underestimation of the effects of small radiation doses although they may give an over-estimate. (author)

Doses and biological effect of ionizing radiation

International Nuclear Information System (INIS)

Hrynkiewicz, A.

1993-01-01

The aim of the monograph is to review practical aspects of dosimetry. The work describes basic units which are used in dosimetry and natural as well as industrial sources of ionizing radiation. Information given in the monograph help in assessment of the radiation risk. 8 refs, 15 tabs

Future Prospects: Ionization Radiation Processing Technology. Chapter 12

International Nuclear Information System (INIS)

Rida Tajau

2017-01-01

This final chapter concluded that the ionizing radiation processing technology was potentially used to develop new and advanced products. The new advanced products which been discussed was HBPUA, printing ink, PSA, hydrogel, bioplastic, SWA, CNT, RVNRL and others. With this new innovative technology, it will develop the country's economy and increase the productivity of manufacturing industry, medical, science and technology and also strenghten the social science field.

Dosimetry methods for the estimation of exposure to ionizing radiation

International Nuclear Information System (INIS)

Lopez Bejarano, Gladys

2012-01-01

Ionizing radiations, by their nature, have required for their detection the use of suitable devices generically referred detecting systems. The detection of secondary particles arising during the processes of ionization and excitation to the passage of radiation in the environment, have constituted the basis of the measurement methods. A detector system is a device that converts the energy of the incident radiation on a signal (electrical, photochemical, etc.) that is easily processable from the technological point of view, but without distorting the original information. These devices have provided qualitative or quantitative information about the radiation of interest. The detector system is a set of a detector together with a processing system. This system has based its operation in methods of: gas ionization, scintillation, semiconductor, film, thermoluminescence, among others. (author) [es

Bond strength of dental adhesive systems irradiated with ionizing radiation.

Science.gov (United States)

Dibo da Cruz, Adriana; Goncalves, Luciano de Souza; Rastelli, Alessandra Nara de Souza; Correr-Sobrinho, Lorenco; Bagnato, Vanderlei Salvador; Boscolo, Frab Norberto

2010-04-01

The aim of the present paper was to determine the effect of different types of ionizing radiation on the bond strength of three different dentin adhesive systems. One hundred twenty specimens of 60 human teeth (protocol number: 032/2007) sectioned mesiodistally were divided into 3 groups according to the adhesives systems used: SB (Adper Single Bond Plus), CB (Clearfil SE Bond) and AP (Adper Prompt Self-Etch). The adhesives were applied on dentin and photo-activated using LED (Lec 1000, MMoptics, 1000 mW/cm2). Customized elastomer molds (0.5 mm thickness) with three orifices of 1.2 mm diameter were placed onto the bonding areas and filled with composite resin (Filtek Z-250), which was photo-activated for 20 s. Each group was subdivided into 4 subgroups for application of the different types of ionizing radiation: ultraviolet radiation (UV), diagnostic x-ray radiation (DX), therapeutic x-ray radiation (TX) and without irradiation (control group, CG). Microshear tests were carried out (Instron, model 4411), and afterwards the modes of failure were evaluated by optical and scanning electron microscope and classified using 5 scores: adhesive failure, mixed failures with 3 significance levels, and cohesive failure. The results of the shear bond strength test were submitted to ANOVA with Tukey's test and Dunnett's test, and the data from the failure pattern evaluation were analyzed with the Mann Whitney test (p = 0.05). No change in bond strength of CB and AP was observed after application of the different radiation types, only SB showed increase in bond strength after UV (p = 0.0267) irradiation. The UV also changed the failure patterns of SB (p = 0.0001). The radio-induced changes did not cause degradation of the restorations, which means that they can be exposed to these types of ionizing radiation without weakening the bond strength.

V. Physical effects in ionizing radiation passage through matter

International Nuclear Information System (INIS)

1984-01-01

The ionization of the medium during absorption of alpha particles is described. The ranges are given of alpha particles in the air and in certain liquids and solids. The absorption of protons and deuterons takes place similarly as in alpha particles but protons and deuterons have a bigger range at the same energy. The term half-thickness has been introduced for the absorption of beta particles. For different energies of beta particles the absorption of these particles is graphically represented for different materials. The greatest attention is devoted to the absorption of electromagnetic radiation, i.e., X radiation and gamma radiation. The mechanisms are explained of absorption by photoelectric effect, the Compton effect and electron pair formation. In X radiation radiotherapy, filters are used, mostly aluminium, copper or zinc plates. The values are given of radiation intensity for different thicknesses of aluminium and copper filters and a survey is given of combined filters for 220 to 400 kV. For radiotherapy purposes great attention is devoted to the calculation of the depth dose. The effects are discussed of ionizing radiation on photographic emulsion, on changes in the colouring of some substances and fluorescence. Also given are the biological effects of ionizing radiation and the theory of direct and indirect effects is briefly described. (E.S.)

Human exposure to non-ionizing radiation and potential adverse health effects

International Nuclear Information System (INIS)

Vulevic, B.; Maric, B.; Zivkovic, D.

1999-01-01

The problem of protection from the non-ionizing radiation has presented an actual subject in the last twenty years both worldwide and in our country. Great attention has been paid to this problem throughout the world and there is not almost a field of human activities that disregards the effect of non-ionizing radiation to the human health.The object of this work is to point concisely, on the basis of numerous domestic and foreign referential data, to the potential adverse health effects caused by uncontrolled exposure to non-ionizing radiation. (author)

Chemical inhibition of cell recovery after irradiation with sparsely and densely ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Evastratova, Ekaterina S.; Petin, Vladislav [A. Tsyb Medical Radiological Research Centre-branch of the National Medical Research Radiological Centre of the Ministry of Health of the Russian Federation, Obninsk (Russian Federation); Kim, Jin Hong; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Advanced Radiation Technology Institute (ARTI), Jeongeup (Korea, Republic of); Lim, Youg Khi [Dept. of Radiological Science, Gachon University, Incheon (Korea, Republic of)

2017-02-15

The dependence of cell survival on exposure dose and the duration of the liquid holding recovery (LHR) was obtained for diploid yeast cells irradiated with ionizing radiation of different linear energy transfer (LET) and recovering from radiation damage without and with various concentrations of cisplatin - the most widely used anticancer drug. The ability of yeast cells to recover from radiation damage was less effective after cell exposure to high-LET radiation, when cells were irradiated without drug. The increase in cisplatin concentration resulted in the disappearance of this difference whereas the fraction of irreversible damage was permanently enlarged independently of radiation quality. The probability of cell recovery was shown to be constant for various conditions of irradiation and recovery. A new mechanism of cisplatin action was suggested according with which the inhibition of cell recovery after exposure to ionizing radiations was completely explained by the production of irreversible damage.

Chemical inhibition of cell recovery after irradiation with sparsely and densely ionizing radiation

International Nuclear Information System (INIS)

Evastratova, Ekaterina S.; Petin, Vladislav; Kim, Jin Hong; Kim, Jin Kyu; Lim, Youg Khi

2017-01-01

The dependence of cell survival on exposure dose and the duration of the liquid holding recovery (LHR) was obtained for diploid yeast cells irradiated with ionizing radiation of different linear energy transfer (LET) and recovering from radiation damage without and with various concentrations of cisplatin - the most widely used anticancer drug. The ability of yeast cells to recover from radiation damage was less effective after cell exposure to high-LET radiation, when cells were irradiated without drug. The increase in cisplatin concentration resulted in the disappearance of this difference whereas the fraction of irreversible damage was permanently enlarged independently of radiation quality. The probability of cell recovery was shown to be constant for various conditions of irradiation and recovery. A new mechanism of cisplatin action was suggested according with which the inhibition of cell recovery after exposure to ionizing radiations was completely explained by the production of irreversible damage

Influence of low dose ionizing radiation on amplification and antitumor activity of LAK/TIL cells

International Nuclear Information System (INIS)

Liu Wei; Hou Dianjun; Qiao Jianwei; Shang Ximei; Li Jieqing

2000-01-01

Objective: To study the influence of low dose ionization on amplification and antitumor activity of LAK/TIL cells. Methods: TIL cells isolated from Lewis lung cancer tissues and LAK cells from spleen of tumor-bearing mouse were irradiated with different low doses of X-rays and were cultured after irradiation. Results: Low dose ionizing radiation improved the amplification volume of LAK/TIL cells, decreased the cell death ratio in amplification process, and increased the toxicity of LAK/TIL cells, Conclusions: Low dose ionizing radiation can result in amplification of biologically activated lymphocytes, and decreases the death ratio of the cells in amplification process

When theory and observation collide: Can non-ionizing radiation cause cancer?

Science.gov (United States)

Havas, Magda

2017-02-01

This paper attempts to resolve the debate about whether non-ionizing radiation (NIR) can cause cancer-a debate that has been ongoing for decades. The rationale, put forward mostly by physicists and accepted by many health agencies, is that, "since NIR does not have enough energy to dislodge electrons, it is unable to cause cancer." This argument is based on a flawed assumption and uses the model of ionizing radiation (IR) to explain NIR, which is inappropriate. Evidence of free-radical damage has been repeatedly documented among humans, animals, plants and microorganisms for both extremely low frequency (ELF) electromagnetic fields (EMF) and for radio frequency (RF) radiation, neither of which is ionizing. While IR directly damages DNA, NIR interferes with the oxidative repair mechanisms resulting in oxidative stress, damage to cellular components including DNA, and damage to cellular processes leading to cancer. Furthermore, free-radical damage explains the increased cancer risks associated with mobile phone use, occupational exposure to NIR (ELF EMF and RFR), and residential exposure to power lines and RF transmitters including mobile phones, cell phone base stations, broadcast antennas, and radar installations. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of ionizing radiation on the filamentous actin of vascular endothelial cell

International Nuclear Information System (INIS)

Yao Xiaowu; Chen Shisheng; Yang Lihe; Lin Juelong; Yang Haiwei

2006-01-01

Objective: To observe the ionizing radiation effect on filamentous actin of vascular endothelial cell and explore its mechanism. Methods: The vascular endothelial cells were irradiated with 0, 2, 4, 6, 8, 10 and 12 Gy 60 Co γ-rays. The cytoskeleton was observed with CLSM at 6 hs after the irradiation and the cytoskeleton protein F-actin detected with flow cytometry after 12 and 24 hs. Results: The damage to cytoskeletons increased with the radiation dose. The cytoskeleton protein F-actin was significantly decreased at 12 hs after the irradiation, and then recovered after 24 hs. Conclusion: Ionizing radiation caused vascular endothelial cell injury by damaging the cytoskeleton and depolymerizating the F-actin. (authors)

Methylation of the ATM promoter in glioma cells alters ionizing radiation sensitivity

International Nuclear Information System (INIS)

Roy, Kanaklata; Wang, Lilin; Makrigiorgos, G. Mike; Price, Brendan D.

2006-01-01

Glioblastomas are among the malignancies most resistant to radiation therapy. In contrast, cells lacking the ATM protein are highly sensitive to ionizing radiation. The relationship between ATM protein expression and radiosensitivity in 3 glioma cell lines was examined. T98G cells exhibited normal levels of ATM protein, whereas U118 and U87 cells had significantly lower levels of ATM and increased (>2-fold) sensitivity to ionizing radiation compared to T98G cells. The ATM promoter was methylated in U87 cells. Demethylation by azacytidine treatment increased ATM protein levels in the U87 cells and decreased their radiosensitivity. In contrast, the ATM promoter in U118 cells was not methylated. Further, expression of exogenous ATM did not significantly alter the radiosensitivity of U118 cells. ATM expression is therefore heterogeneous in the glioma cells examined. In conclusion, methylation of the ATM promoter may account for the variable radiosensitivity and heterogeneous ATM expression in a fraction of glioma cells

Radioresistant DNA synthesis in cells of patients showing increased chromosomal sensitivity to ionizing radiation

International Nuclear Information System (INIS)

Barenfeld, L.S.; Pleskach, N.M.; Bildin, V.N.; Prokofjeva, V.V.; Mikhelson, V.M.

1986-01-01

The rate of DNA synthesis after γ-irradiation was studied either by analysis of the steady-state distribution of daughter [ 3 H]DNA in alkaline sucrose gradients or by direct assay of the amount of [ 3 H]thymidine incorporated into DNA of fibroblasts derived from a normal donor (LCH882) and from Down's syndrome (LCH944), Werner's syndrome (WS1LE) and xeroderma pigmentosum (XP2LE) patients with chromosomal sensitivity to ionizing radiation. Doses of γ-irradiation that markedly inhibited the rate of DNA synthesis in normal human cells caused almost no inhibition of DNA synthesis in the cells from the affected individuals. The radioresistant DNA synthesis in Down's syndrome cells was mainly due to a much lower inhibition of replicon initiation than that in normal cells; these cells were also more resistant to damage that inhibited replicon elongation. Our data suggest that radioresistant DNA synthesis may be an intrinsic feature of all genetic disorders showing increased radiosensitivity in terms of chromosome aberrations. (orig.)

Preventive medical programmes to personnel exposed to ionizing radiation

International Nuclear Information System (INIS)

Estrada F, E.

1996-01-01

The increasing use of ionizing radiation in the medical field as well as in industry and research grants has special importance to the security aspects related to the individual as well as his surroundings, reason for which the implementation of effective Occupational Radiation Protection Programmes constitutes a priority. Presently, in Guatemala, an Occupational Medicine Programme, directed to the Radiosanitary watch over of occupationally exposed personnel does not exist. It is the goal in this project to organize and establish such programme, based on protective and training actions focused toward the employee as the main entity, his specific activities and his work surroundings. Medical watch over together with Radiation Protection will permit the reduction of the occurrence probability of accidents or incidents, as well as the limitation of stochastic effects to the undermost values. The application scope of the present project is, in the first place, directed to the occupationally exposed personnel of the Direcci[n General de Energ[a Nuclear, as regulatory entity of these activities, and afterwards, its application in the different institutions which work with ionizing radiations. All the previously exposed is based on the Nuclear Legislation prevailing in Guatemala as well as the recommendations of international organizations. (author)

CARCINOGENIC EFFECTS OF LOW DOSES OF IONIZING RADIATION

Science.gov (United States)

Carcinogenic Effects of Low Doses of Ionizing RadiationR Julian Preston, Environmental Carcinogenesis Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711The form of the dose-response curve for radiation-induced cancers, particu...

Ionization versus indirect effects of ionizing radiation on cellular DNA

International Nuclear Information System (INIS)

Cadet, Jean; Ravanat, Jean-Luc; Douki, Thierry

2012-01-01

Emphasis has been placed in the last decade on the elucidation of the main degradation pathways of isolated DNA mediated by hydroxyl radical (OH) and one-electron oxidation reactions as the result of indirect and direct effects of ionizing radiation respectively. This has led to the isolation and characterization of about 100 oxidized purine and pyrimidine nucleosides if hydroperoxide precursors and diastereomers are included. However, far less information is available on the mechanisms of radiation-induced degradation of bases in cellular DNA mostly due partly to analytical difficulties. It may be reminded that the measurement of oxidized nucleosides and bases in nuclear DNA is still a challenging issue which until recently has been hampered by the use of inappropriate methods such as the GC-MS that have led to overestimated values of the lesions by factors varying between two and three orders of magnitude. At the present, using the accurate and sensitive HPLC/MS/MS assay, 11 single modified nucleosides and bases were found to be generated in cellular DNA upon exposure to gamma rays and heavy ions. This validates several of the OH-mediated oxidation pathways of thymine, guanine and adenine that were previously inferred from model studies. The concomitant decrease in the yields of oxidized bases with the increase in the LET of heavy ions is accounted for by the preponderance of indirect effects in the damaging action of ionizing radiation on DNA. Further evidence for the major role played by .OH was provided by the results of exposure of cells to high intensity 266 nm laser pulses. Under these conditions 8-oxo-7,8-dihydroguanine is mostly produced by biphotonic ionization of DNA nucleobases and subsequent hole migration to guanine bases. It is likely that some of the oxidized bases that have been isolated as single lesions are in fact involved in clustered damage. Interestingly it was recently shown that a single oxidation hit is capable of generating complex

Ionization radiations - basis, risks and benefits

International Nuclear Information System (INIS)

Bodart, F.

1991-01-01

An attempt is made to discuss the use of ionizing radiations in an impartial way. Ionizing radiation is potentially harmfull; excessive doses have a devastating effect on living cells. However, there is no direct, conclusive evidence of human disability, either in the form of cancer or genetic anomalies, arising as a consequence of low-level doses of x- or gamma-rays of about 0.01 Gray (1 rad) the entire dose range involved in medical radiography or in nuclear industry. Statements appearing in the press that a certain number of excess cancers will be produced are estimates, based maybe on plausible assumptions, but estimates nevertheless; they are not measured quantities or established facts. A balanced view of radiation must include appreciation of the substantial benefits which result from their use in both medicine and industry. The risks are small and hard to demonstrate, and it is instructive to make a comparison with the other hazards occuring continually in an industrialized society, such as driving a motorcar or smoking cigarettes. (Author)

Comparison of the dose-effect relationship for UV radiation and ionizing radiation

International Nuclear Information System (INIS)

Leenhouts, H.P.; Sijsma, M.J.; Chadwick, K.H.

1990-06-01

Ionizing radiation and ultraviolet radiation (UV) are both physical agents with mutagenic and carcinogenic properties. However, there are some basic differences in the fundamental mechanism of their interaction with biological material that may have consequences for risk assessment. In this paper the dose-effect relationships for gamma radiation and UV at cellular level will be used to demonstrate the different radio-biological effectiveness of both agents. The results will be discussed in the framework of a biophysical model, based on the assumption that DNA doublestranded lesions are crucial for the cytotoxic action. After exposure to ionizing radiation, the lesions are fixed immediately following irradiation, but after UV exposure the lethal lesions are recognized only in the next DNA synthesis phase. The combination of this concept with the mechanism of lesion induction and the possibility of repair, leads to different dose and time relationships for the radiation effects of both agents. The possible consequences for risk assessment at low levels will be discussed. (author). 9 refs.; 5 figs

Study of genomic instability induced by low dose ionizing radiation

International Nuclear Information System (INIS)

Seoane, A.; Crudeli, C.; Dulout, F.

2006-01-01

The crews of commercial flights and services staff of radiology and radiotherapy from hospitals are exposed to low doses of ionizing radiation. Genomic instability includes those adverse effects observed in cells, several generations after the exposure occurred. The purpose of this study was to analyze the occurrence of genomic instability by very low doses of ionizing radiation [es

Influence of beryllium ceramics nano-structuring by iron atoms on increase of their stability to ionizing radiations effect; Vliyanie nanostrukturirovaniya berillievykh keramik atomami zheleza na povyshenie ikh ustojchivosti k vozdejstviyu ioniziruyushchikh izluchenij

Energy Technology Data Exchange (ETDEWEB)

Polyakov, A I; Bitenbaev, M I [Fiziko-Tekhnicheskij Inst., Almaty (Kazakhstan)

2007-07-01

In the work a new results on beryllium ceramics nano-structuring effect by iron oxide atoms on radiation defects quantum yield value G in these materials and defects depth constants in ionizing radiation fields k are presented. Experimental data under dependence of G and k values from concentration of iron atoms in beryllium ceramic matrix are presented. It is shown, that structure modification of beryllium ceramics by feedings on the iron base leads to sharp decrease (almost in 30 times) of radiation defects quantum yield value, i.e. to increase of these ceramics stability enhancement to ionizing radiation effect.

Ionizing radiation measurements using low cost instruments for teaching in college or high-school in Brazil

Science.gov (United States)

Silva, M. C.; Vilela, D. C.; Migoto, V. G.; Gomes, M. P.; Martin, I. M.; Germano, J. S. E.

2017-11-01

Ionizing radiation one of modern physics experimental teaching in colleges and high school can be easily implemented today due to low coasts of detectors and also electronic circuits and data acquisition interfaces. First it is interesting to show to young’s students what is ionizing radiation and from where they appears near ground level? How it is possible to measure these radiations and how to check intensities variation during day, night, dry and wet periods in the same school? For increasing interest and stimulation in others students how to proceed in making the graphics of the ionizing radiation and presenting him in real time using Web internet facilities? Many others facilities like calibration of the detector using low intensities radioactive ionizing radiation sources, make comparison of the measurements and discussions of the results should be possible between many groups of students from several schools in the region of Brazil. This paper presents the experimental procedures including detectors and associated electronic including data acquisition, graphics elaboration and Web internet procedures to discuss and exchanging data measurements from several schools.

Monitoring the genetic health of persons in Goiania accidentally exposed to ionizing radiation from caesium-137

International Nuclear Information System (INIS)

Da Cruz, A.D.; Glickman, B.W.

1998-01-01

This work describes the long term genetic monitoring of the Goiania population exposed to ionizing radiation from 137 Cs, using cytogenetic and molecular endpoints. Cytogenetically, micronucleus frequencies differentiated groups exposed to different levels of radiation. Two molecular methods were employed: 1) the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed four and a half years after original exposure. The spectrum of hprt mutations recovered from ten individuals exposed to relatively high doses of radiation revealed a fourfold increase in the frequency of A:T → G:C transitions. The increase is consistent with the effects of ionizing radiation in prokaryotes and lower eukaryotes. Additionally, a twofold increase in the frequency of deletions was observed which may reflect radiation induced DNA strand breakage; 2) determination of microsatellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distributions of somatic microsatellite alterations in exposed and non-exposed populations were not different. Our assay lacked sensitivity to discriminate between spontaneous and induced microsatellite instability and therefore, is not suitable for population monitoring. Finally, we estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased nearly twenty-fourfold. The risk of carcinogenesis was increased by a factor of 1.5. (author)

Monitoring the genetic health of persons in Goiania accidentally exposed to ionizing radiation from caesium-137

Energy Technology Data Exchange (ETDEWEB)

Da Cruz, A D; Glickman, B W [Centre for Environmental Health, Department of Biology, University of Victoria, Victoria, BC (Canada)

1998-12-01

This work describes the long term genetic monitoring of the Goiania population exposed to ionizing radiation from {sup 137}Cs, using cytogenetic and molecular endpoints. Cytogenetically, micronucleus frequencies differentiated groups exposed to different levels of radiation. Two molecular methods were employed: (1) the hprt clonal assay, involving in vitro selection of 6-thioguanine-resistant hprt mutant clones which were characterized at the molecular level using RT-PCR and genomic analysis. Ionizing radiation exposure initially elevated hprt mutation frequency which gradually diminished, so that no significant increase was observed four and a half years after original exposure. The spectrum of hprt mutations recovered from ten individuals exposed to relatively high doses of radiation revealed a fourfold increase in the frequency of A:T {yields} G:C transitions. The increase is consistent with the effects of ionizing radiation in prokaryotes and lower eukaryotes. Additionally, a twofold increase in the frequency of deletions was observed which may reflect radiation induced DNA strand breakage; (2) determination of microsatellite instability using fluorescent PCR and genomic DNA from mononuclear cells. The frequency distributions of somatic microsatellite alterations in exposed and non-exposed populations were not different. Our assay lacked sensitivity to discriminate between spontaneous and induced microsatellite instability and therefore, is not suitable for population monitoring. Finally, we estimated the risk associated with radiation exposure for the exposed Goiania population. The estimated genetic risk of dominant disorders in the first post-exposure generation was increased nearly twenty-fourfold. The risk of carcinogenesis was increased by a factor of 1.5. (author)

Food preservation by ionizing radiation in Nigeria. Present and future status

International Nuclear Information System (INIS)

Olorunda, A.O.; Aboaba, F.O.

1978-01-01

Research into the use of ionizing radiation in food preservation in Nigeria is still in its very infancy and most of the work done to date is at the exploratory stage. Such work has, however, demonstrated the potential of ionizing radiation in prolonging the shelf-life of yams and, possibly, onions. The paper reviews the present status of the use of radiation food preservation in Nigeria. The present research programme of the Faculty of Technology, University of Ibadan, which includes a wider application of ionizing radiation to fruit and vegetable preservation and grain storage, is also highlighted. The primary objectives of this programme are to establish the wholesomeness of the irradiated foods and the economics of the process. (author)

The Enceladus Ionizing Radiation Environment: Implications for Biomolecules

Science.gov (United States)

Teodoro, L. A.; Elphic, R. C.; Davila, A. F.; McKay, C.; Dartnell, L.

2016-12-01

Enceladus' subsurface ocean is a possible abode for life, but it is inaccessible with current technology. However, icy particles and vapor are being expelled into space through surface fractures known as Tiger Stripes, forming a large plume centered in the South Polar Terrains. Direct chemical analyses by Cassini have revealed salts and organic compounds in a significant fraction of plume particles, which suggests that the subsurface ocean is the main source of materials in the plume (i.e. frozen ocean spray). While smaller icy particles in the plume reach escape velocity and feed Saturn's E-ring, larger particles fall back on the moon's surface, where they accumulate as icy mantling deposits at practically all latitudes. The organic content of these fall-out materials could be of great astrobiological relevance. Galactic Cosmic Rays (GCRs) that strike both Enceladus' surface and the lofted icy particles produce ionizing radiation in the form of high-energy electrons, protons, gamma rays, neutrons and muons. An additional source of ionizing radiation is the population of energetic charged particles in Saturn's magnetosphere. The effects of ionizing radiation in matter always involve the destruction of chemical bonds and the creation of free radicals. Both affect organic matter, and can damage or destroy biomarkers over time. Using ionizing radiation transport codes, we recreated the radiation environment on the surface of Enceladus, and evaluated its possible effects on organic matter (including biomarkers) in the icy mantling deposits. Here, we present full Monte-Carlo simulations of the nuclear reactions induced by the GCRs hitting Enceladus's surface using a code based on the GEANT-4 toolkit for the transport of particles. To model the GCR primary spectra for Z= 1-26 (protons to iron nuclei) we assumed the CREAME96 model under solar minimum, modified to take into account Enceladus' location. We considered bulk compositions of: i) pure water ice, ii) water ice

Chromosomal instability induced by ionizing radiation

International Nuclear Information System (INIS)

Morgan, W.F.; Marder, B.A.; Day, J.P.

1995-01-01

There is accumulating evidence indicating genomic instability can manifest multiple generations after cellular exposure to DNA damaging agents. For instance, some cells surviving exposure to ionizing radiations show delayed reproductive cell death, delayed mutation and / or delayed chromosomal instability. Such instability, especially chromosome destabilization has been implicated in mutation, gene amplification, cellular transformation, and cell killing. To investigate chromosomal instability following DNA damage, we have used fluorescence in situ hybridization to detect chromosomal rearrangements in a human/hamster somatic hybrid cell line following exposure to ionizing radiation. Delayed chromosomal instability was detected when multiple populations of uniquely arranged metaphases were observed in clonal isolates raised from single cells. The relationship between delayed chromosomal destabilization and other endpoints of genomic instability, namely; delayed mutation and gene amplification will be discussed, as will the potential cytogenetic and molecular mechanisms contributing to delayed chromosomal instability

[Occupational diseases caused by ionizing radiation in Poland, 1971-2006].

Science.gov (United States)

Wilczyńska, Urszula; Szeszenia-Dabrowska, Neonila

2008-01-01

The whole spectrum of disorders of the hematopoietic tissue, eye and skin induced by ionizing radiation covers complex pathologies termed as a postirradiation syndrome, as well as various malignancies. The aim of this work is to present the data on incidence of occupational diseases with ionizing radiation as a causative agent. The work is based on the data compiled from "Occupational Diseases Reporting Forms" for the years 1971-2006 collected in the Central Register of Occupational Diseases. The incidence of certified occupational diseases with ionizing radiation as a causative agent is expressed in absolute numbers and the rate per 100 000 employees. The data comprise information on disease entities, gender, age, exposure duration and the branch of national economy. In total, 599 diseases (0.2% of all occupational diseases) were diagnosed as those induced by ionizong radiation. Annual incidence rates per 100,000 employees fell within the range of 0.0-0.7. Miners formed the major (51.9%) occupational group affected by ionizing radiation. They were followed by health care (34.3%) and construction (6.4%) workers. Cancers made over 50% of pathologies located at 28 sites. These included cancers of lung (59.2%), skin (10.0%) and hematopoietic tissue (8.7%). Almost all (99.35) diseases recorded in the mining industry were cancers. Non-cancer diseases were more frequent in health care workers, among them postradiation cataract occupied the first place. A great deal of reported cancer sites give rise to controversy in terms of the cause-effect association with ionizing radiation exposure and also due to incomplete data on exposure level. Postradiation cancers among health care workers have not been registered over recent years, which means that occupational exposure surveillance carried out for many years proves to be effective. Distant effects of exposure to ionizing radiation, revealed in workers of no longer existing uranium mine, appeared to be a particular problem

Solar Irradiance Changes And Photobiological Effects At Earth's Surface Following Astrophysical Ionizing Radiation Events

Science.gov (United States)

Thomas, Brian; Neale, Patrick

2016-01-01

Astrophysical ionizing radiation events have been recognized as a potential threat to life on Earth for decades. Although there is some direct biological damage on the surface from redistributed radiation several studies have indicated that the greatest long term threat is from ozone depletion and subsequent heightened solar ultraviolet (UV) radiation. It is known that organisms exposed to this irradiation experience harmful effects such as sunburn and even direct damage to DNA, proteins, or other cellular structures. Simulations of the atmospheric effects of a variety of events (such as supernovae, gamma-ray bursts, and solar proton events) have been previously published, along with estimates of biological damage at Earth's surface. In the present work, we employed a radiative transfer model to expand and improve calculations of surface-level irradiance and biological impacts following an ionizing radiation event. We considered changes in surface-level UVB, UVA, and photosynthetically active radiation (visible light). Using biological weighting functions we have considered a wide range of effects, including: erythema and skin cancer in humans; inhibition of photosynthesis in the diatom Phaeodactylum sp. and dinoflagellate Prorocentrum micans inhibition of carbon fixation in Antarctic phytoplankton; inhibition of growth of oat (Avena sativa L. cv. Otana) seedlings; and cataracts. We found that past work overestimated UVB irradiance, but that relative estimates for increase in exposure to DNA damaging radiation are still similar to our improved calculations. We also found that the intensity of biologically damaging radiation varies widely with organism and specific impact considered; these results have implications for biosphere-level damage following astrophysical ionizing radiation events. When considering changes in surface-level visible light irradiance, we found that, contrary to previous assumptions, a decrease in irradiance is only present for a short time in

Side effects of ionizing radiation on healthy tissues and organs at risk

International Nuclear Information System (INIS)

Cosset, J.M.

2010-01-01

Ionizing radiations induce cell death, causing deterministic or stochastic side-effects. This paper briefly summarizes the biological mechanisms of early and late side-effects of ionizing radiations on healthy tissue. (author)

Progress in research on ionizing radiation-induced microRNA

International Nuclear Information System (INIS)

Hu Zheng; Tie Yi; Sun Zhixian; Zheng Xiaofei

2011-01-01

MicroRNAs (miRNAs) are small single-stranded noncoding RNAs consisting of 21-23 nucleotides that play important gene-regulatory roles in eukaryotes by pairing to the mRNAs of protein-coding genes to direct their posttranscriptional repression. A growing body of evidence indicates that alterations in miRNA expression may occur following exposure to several oxidative stress including ionizing radiation. So miRNAs may serve as potential new targets for co-therapies aiming to improve the effects of radiation disease therapy in cancer patients. The progress in research on ionizing radiation-induced miRNAs is reviewed in this paper. (authors)

Increase in Efficiency of Use of Pedestrian Radiation Portal Monitors

Science.gov (United States)

Solovev, D. B.; Merkusheva, A. E.

2017-11-01

Most international airports in the world use radiation portal monitors (RPM) for primary radiation control organization. During the exploitation pedestrian radiation portal monitors operators (in the Russian Federation it is a special subdivision of customs officials) have certain problems related to the search of an ionizing radiation source causing the alarm signal of a radiation monitor. Radiation portal monitors at standard (factory) settings have to find out the illegal moving of the radioisotopes moved by physical persons passing through a controlled zone and having a steady radiation by the gamma or neutron channel. The problem is that recently the number of the ownerships who underwent treatment or medical diagnostics with the use of radio pharmaceuticals considerably increased, i.e,. ownerships represent such an ionizing radiation source. The operator of the radiation portal monitor has to define very quickly whether the ownership is a violator (takes unsolved radioisotopes illegally) or is just a patient of the clinic who underwent treatment/diagnostics with the use of radio pharmaceuticals. The research showing the radioisotopes which are most often used in the medical purposes are given in article, it is offered to use the new software developed by the authors allowing the operator of the radiation portal monitor to define the location of the ownership which has such ionizing radiation source by the activity of radiation similar to the radiation from radio pharmaceuticals.

Possible use of ionizing radiation in food preservation

International Nuclear Information System (INIS)

Salkova, Z.

1975-01-01

An informative survey is presented of the application of ionizing radiation in the food industry based on experiments performed and literary data. The possibility of radiation treatment of potatoes, onions and strawberries is discussed and the positive effect of experimentally determined gamma radiation doses on the extension of storage of meat is shown

Untargeted effects of ionizing radiation: Implications for radiation pathology

International Nuclear Information System (INIS)

Wright, Eric G; Coates, Philip J

2006-01-01

The dogma that genetic alterations are restricted to directly irradiated cells has been challenged by observations in which effects of ionizing radiation, characteristically associated with the consequences of energy deposition in the cell nucleus, arise in non-irradiated cells. These, so called, untargeted effects are demonstrated in cells that have received damaging signals produced by irradiated cells (radiation-induced bystander effects) or that are the descendants of irradiated cells (radiation-induced genomic instability). Radiation-induced genomic instability is characterized by a number of delayed adverse responses including chromosomal abnormalities, gene mutations and cell death. Similar effects, as well as responses that may be regarded as protective, have been attributed to bystander mechanisms. Whilst the majority of studies to date have used in vitro systems, some adverse non-targeted effects have been demonstrated in vivo. However, at least for haemopoietic tissues, radiation-induced genomic instability in vivo may not necessarily be a reflection of genomically unstable cells. Rather the damage may reflect responses to ongoing production of damaging signals; i.e. bystander responses, but not in the sense used to describe the rapidly induced effects resulting from direct interaction of irradiated and non-irradiated cells. The findings are consistent with a delayed and long-lived tissue reaction to radiation injury characteristic of an inflammatory response with the potential for persisting bystander-mediated damage. An important implication of the findings is that contrary to conventional radiobiological dogma and interpretation of epidemiologically-based risk estimates, ionizing radiation may contribute to malignancy and particularly childhood leukaemia by promoting initiated cells rather than being the initiating agent. Untargeted mechanisms may also contribute to other pathological consequences

Regulatory control of ionizing radiations in Ecuador

International Nuclear Information System (INIS)

Benitez, Manuel

1996-03-01

This document deals with legal aspects for controlling ionizing radiations, radiological safety regulations and objectives, scopes and features of the national radioprotection planning in Ecuador. (The author)

Effect of ionizing radiation on advanced life support medications

International Nuclear Information System (INIS)

Sullivan, D.J.; Hubbard, L.B.; Broadbent, M.V.; Stewart, P.; Jaeger, M.

1987-01-01

Advanced life support medications stored in emergency department stretcher areas, diagnostic radiology rooms, and radiotherapy suites are exposed to ionizing radiation. We hypothesized that radiation may decrease the potency and thus the shelf life of medications stored in these areas. Atropine, dopamine, epinephrine, and isoproterenol were exposed to a wide range of ionizing radiation. The potency of the four drugs was unaffected by levels of radiation found in ED stretcher areas and high-volume diagnostic radiograph rooms (eg, chest radiograph, computed tomography, fluoroscopy). The potency of atropine may be reduced by gamma radiation in high-use radiotherapy suites. However, dopamine, epinephrine, and isoproterenol were unaffected by high doses of gamma radiation. Atropine, dopamine, epinephrine, and isoproterenol may be safely kept in ED stretcher areas and diagnostic radiology rooms without loss of potency over the shelf life of the drugs

Studying the Effect of Ionization Radiation of 60Co on the Spirulina

Science.gov (United States)

Ai, Weidang; Guo, Shuang-Sheng; Ai, Weidang; Dong, Wen-Ping; Qin, Li-Feng; Tang, Yong-Kang

It studied the effect of ionization radiation on the Spirulina plastensis(No.6) by using the γ-rays of 60 Co. In the experiment, Spirulina were irradiated, and the dose of the ionization radiation covered 0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0kGy. After irradiating, these Spirulina were cultured under the same conditions. During the course of the experiment, the growth rate, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the results, low dose of γ-rays (less than 1.5kGy) could improve the content of phycobilin and protein of Spirulina. Only small changes in the morphology of algae filament were found at dose less than 1.0kGy. But with the increase of the dose of γ-rays (more than 1.5kGy), the filaments would break up or even disintegrate. Spirulina had stronger ionization radiation proof and self-rehabilitation capacity, but the growth of Spirulina was stagnated. The LD50 (i.e. the dose resulted in 50% death of the Spirulina) of the colony was 2.0kGy. Considering the capacity of being resistant to γ-rays irradiation, Spirulina can be considered as one of the key biological components in the Controlled Ecological Life Support System (CELSS) for future long-term space missions. Keywords: Controlled Ecological Life Support System (CELSS); Spirulina; ionization radiation; biological component

Strategies for protection against exposure to ionizing radiation

International Nuclear Information System (INIS)

Goel, H.C.

2005-01-01

Radiations are known to be mutagenic, carcinogenic and cyto-lethal depending on the total dose, dose rate, quality of radiation and many other factors related to the person exposed. Therefore strategies for protection against exposure to ionizing radiations have to be accordingly planned. Radioprotection, though remains prophylactic in principle, includes mitigating and therapeutic modalities also. Initially, the central theme of biological radioprotection has been to protect against radiation-induced lethality and to optimize radiotherapy of tumours; the emphasis has now extended to cover many more situations of planned and unplanned nature. The central dogma of radioprotection work has been antioxidant action, which is relevant indeed against low LET radiation. The increasing understanding of the mechanism of radiation damage, however, permitted the advent of newer agents of both synthetic and natural origin. Sulfhydryl compounds like cysteamine, AET, Amifostine and endogenous molecules like GSH, SOD etc have been very important agents. Molecules like cytokines, immunomodulators, anti-inflammatory agents, angiotensin converting enzymes, metallo-elements and metallothionins, DNA ligands and Calcium antagonists have also been investigated recently. Unfortunately, no single agent could yield desired results especially due to toxicity at their radioprotective concentration. This led to the emergence of combinational modality where two or more agents working with different mechanisms could synergistically complement radioprotective action.. Recently, herbal extracts and dietary agents, which are the natural combinations of a large number of compounds that have important attributes to counter the damaging effects of ionizing radiations, have gained world-wide interest.. These agents have been found to be less toxic. Decorporation of radionuclei and protection against low dose chronic exposures like space flights and long haul inter-continental flights need to be

Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

International Nuclear Information System (INIS)

Perez, C.F.

1984-08-01

The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT + colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references

Ionizing and ultraviolet radiation enhances the efficiency of DNA mediated gene transfer in vitro

Energy Technology Data Exchange (ETDEWEB)

Perez, C.F.

1984-08-01

The enhancement effects of ionizing and non-ionizing radiation on the efficiency of DNA mediated gene transfer were studied. Confluent Rat-2 cells were transfected with purified SV40 viral DNA, irradiated with either X-rays or ultraviolet, trypsinized, plated, and assayed for the formation of foci on Rat-2 monolayers. Both ionizing and ultraviolet radiation enhanced the frequency of A-gene transformants/survivor compared to unirradiated transfected cells. These enhancements were non-linear and dose dependent. A recombinant plasmid, pOT-TK5, was constructed that contained the SV40 virus A-gene and the Herpes Simplex virus (HSV) thymidine kinase (TK) gene. Confluent Rat-2 cells transfected with pOT-TK5 DNA and then immediately irradiated with either X-rays or 330 MeV/amu argon particles at the Berkeley Bevalac showed a higher frequency of HAT/sup +/ colonies/survivor than unirradiated transfected cells. Rat-2 cells transfected with the plasmid, pTK2, containing only the HSV TK-gene were enhanced for TK-transformation by both X-rays and ultraviolet radiation. The results demonstrate that radiation enhancement of the efficiency of DNA mediated gene transfer is not explained by increased nuclear uptake of the transfected DNA. Radiation increases the competence of the transfected cell population for genetic transformation. Three models for this increased competence are presented. The targeted integration model, the inducible recombination model, the partition model, and the utilization of DNA mediated gene transfer for DNA repair studies are discussed. 465 references.

Ionizing radiation alters the properties of sodium channels in rat brain synaptosomes

Energy Technology Data Exchange (ETDEWEB)

Mullin, M J; Hunt, W A; Harris, R A

1986-08-01

The effect of ionizing radiation on neuronal membrane function was assessed by measurement of neurotoxin-stimulated /sup 22/Na/sup +/ uptake by rat brain synaptosomes. High-energy electrons and gamma photons were equally effective in reducing the maximal uptake of /sup 22/Na/sup +/ with no significant change in the affinity of veratridine for its binding site in the channel. Ionizing radiation reduced the veratridine-stimulated uptake at the earliest times measured (3 and 5 s), when the rate of uptake was greatest. Batrachotoxin-stimulated /sup 22/Na/sup +/ uptake was less sensitive to inhibition by radiation. The binding of (/sup 3/H)saxitoxin to its receptor in the sodium channel was unaffected by exposure to ionizing radiation. The effect of ionizing radiation on the lipid order of rat brain synaptic plasma membranes was measured by the fluorescence polarization of the molecular probes 1,6-diphenyl-1,3,5-hexatriene and 1-(4-(trimethylammonium)phenyl)-6-phenyl-1,3,5-hexatriene. A dose of radiation that reduced the veratridine-stimulated uptake of /sup 22/Na/sup +/ had no effect on the fluorescence polarization of either probe. These results demonstrate an inhibitory effect of ionizing radiation on the voltage-sensitive sodium channels in rat brain synaptosomes. This effect of radiation is not dependent on changes in the order of membrane lipids.

Ionizing radiation and thyroid cancer

Energy Technology Data Exchange (ETDEWEB)

Hall, P. (Karolinska Inst., Stockholm (Sweden). Inst. of Environmental Medicine); Holm, L.E. (Swedish Radiation Protection Inst., Stockholm (Sweden))

1994-01-01

Epidemiological studies provide the primary data source on cancer risk in man after exposure to ionizing radiation. The present paper discusses methodological difficulties in epidemiological studies and reviews current epidemiological knowledge on radiation-induced thyroid cancer. Most studies of radiation-induced cancer are of a ''historical observational'' type and are also non-experimental in design. Seldom is there an opportunity to consider other factors playing on cancer risk. Since many of the study subjects were exposed a long time ago there could also be difficulties in calculating the radiation doses, and to identify and follow the exposed subjects. Short exposure to low doses of gamma radiation can induce thyroid cancer in children, whereas a relationship between protracted low-dose exposure and thyroid cancer has not been established so far. The most important future issues concerning radiation-induced thyroid cancer are the risks following low radiation doses and/or protracted radiation exposure and cancer risks after [sup 131]I exposure in childhood. (authors). 35 refs., 3 tabs.

Space Weather Nowcasting of Atmospheric Ionizing Radiation for Aviation Safety

Science.gov (United States)

Mertens, Christopher J.; Wilson, John W.; Blattnig, Steve R.; Solomon, Stan C.; Wiltberger, J.; Kunches, Joseph; Kress, Brian T.; Murray, John J.

2007-01-01

There is a growing concern for the health and safety of commercial aircrew and passengers due to their exposure to ionizing radiation with high linear energy transfer (LET), particularly at high latitudes. The International Commission of Radiobiological Protection (ICRP), the EPA, and the FAA consider the crews of commercial aircraft as radiation workers. During solar energetic particle (SEP) events, radiation exposure can exceed annual limits, and the number of serious health effects is expected to be quite high if precautions are not taken. There is a need for a capability to monitor the real-time, global background radiations levels, from galactic cosmic rays (GCR), at commercial airline altitudes and to provide analytical input for airline operations decisions for altering flight paths and altitudes for the mitigation and reduction of radiation exposure levels during a SEP event. The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model is new initiative to provide a global, real-time radiation dosimetry package for archiving and assessing the biologically harmful radiation exposure levels at commercial airline altitudes. The NAIRAS model brings to bear the best available suite of Sun-Earth observations and models for simulating the atmospheric ionizing radiation environment. Observations are utilized from ground (neutron monitors), from the atmosphere (the METO analysis), and from space (NASA/ACE and NOAA/GOES). Atmospheric observations provide the overhead shielding information and the ground- and space-based observations provide boundary conditions on the GCR and SEP energy flux distributions for transport and dosimetry simulations. Dose rates are calculated using the parametric AIR (Atmospheric Ionizing Radiation) model and the physics-based HZETRN (High Charge and Energy Transport) code. Empirical models of the near-Earth radiation environment (GCR/SEP energy flux distributions and geomagnetic cut-off rigidity) are benchmarked

Innate immune genes including a mucin-like gene, mul-1, induced by ionizing radiation in Caenorhabditis elegans.

Science.gov (United States)

Kimura, Takafumi; Takanami, Takako; Sakashita, Tetsuya; Wada, Seiichi; Kobayashi, Yasuhiko; Higashitani, Atsushi

2012-10-01

The effect of radiation on the intestine has been studied for more than one hundred years. It remains unclear, however, whether this organ uses specific defensive mechanisms against ionizing radiation. The infection with Pseudomonas aeruginosa (PA14) in Caenorhabditis elegans induces up-regulation of innate immune response genes. Here, we found that exposure to ionizing radiation also induces certain innate immune response genes such as F49F1.6 (termed mul-1), clec-4, clec-67, lys-1 and lys-2 in the intestine. Moreover, pre-treatment with ionizing radiation before seeding on PA14 lawn plate significantly increased survival rate in the nematode. We also studied transcription pathway of the mul-1 in response to ionizing radiation. Induction of mul-1 gene was highly dependent on the ELT-2 transcription factor and p38 MAPK. Moreover, the insulin/IGF-1 signal pathway works to enhance induction of this gene. The mul-1 gene showed a different induction pattern from the DNA damage response gene, ced-13, which implies that the expression of this gene might be triggered as an indirect effect of radiation. Silencing of the mul-1 gene led to growth retardation after treatment with ionizing radiation. We describe the cross-tolerance between the response to radiation exposure and the innate immune system.

Radiation, ionization, and detection in nuclear medicine

International Nuclear Information System (INIS)

Gupta, Tapan K.

2013-01-01

Up-to-date information on a wide range of topics relating to radiation, ionization, and detection in nuclear medicine. In-depth coverage of basic radiophysics relating to diagnosis and therapy. Extensive discussion of instrumentation and radiation detectors. Detailed information on mathematical modelling of radiation detectors. Although our understanding of cancer has improved, the disease continues to be a leading cause of death across the world. The good news is that the recent technological developments in radiotherapy, radionuclide diagnostics and therapy, digital imaging systems, and detection technology have raised hope that cancer will in the future be combatted more efficiently and effectively. For this goal to be achieved, however, safe use of radionuclides and detailed knowledge of radiation sources are essential. Radiation, Ionization, and Detection in Nuclear Medicine addresses these subjects and related issues very clearly and elaborately and will serve as the definitive source of detailed information in the field. Individual chapters cover fundamental aspects of nuclear radiation, including dose and energy, sources, and shielding; the detection and measurement of radiation exposure, with detailed information on mathematical modelling; medical imaging; the different types of radiation detector and their working principles; basic principles of and experimental techniques for deposition of scintillating materials; device fabrication; the optical and electrical behaviors of radiation detectors; and the instrumentation used in nuclear medicine and its application. The book will be an invaluable source of information for academia, industry, practitioners, and researchers.

Radiation, ionization, and detection in nuclear medicine

Energy Technology Data Exchange (ETDEWEB)

Gupta, Tapan K. [Radiation Monitoring Devices Research, Nuclear Medicine, Watertown, MA (United States)

2013-08-01

Up-to-date information on a wide range of topics relating to radiation, ionization, and detection in nuclear medicine. In-depth coverage of basic radiophysics relating to diagnosis and therapy. Extensive discussion of instrumentation and radiation detectors. Detailed information on mathematical modelling of radiation detectors. Although our understanding of cancer has improved, the disease continues to be a leading cause of death across the world. The good news is that the recent technological developments in radiotherapy, radionuclide diagnostics and therapy, digital imaging systems, and detection technology have raised hope that cancer will in the future be combatted more efficiently and effectively. For this goal to be achieved, however, safe use of radionuclides and detailed knowledge of radiation sources are essential. Radiation, Ionization, and Detection in Nuclear Medicine addresses these subjects and related issues very clearly and elaborately and will serve as the definitive source of detailed information in the field. Individual chapters cover fundamental aspects of nuclear radiation, including dose and energy, sources, and shielding; the detection and measurement of radiation exposure, with detailed information on mathematical modelling; medical imaging; the different types of radiation detector and their working principles; basic principles of and experimental techniques for deposition of scintillating materials; device fabrication; the optical and electrical behaviors of radiation detectors; and the instrumentation used in nuclear medicine and its application. The book will be an invaluable source of information for academia, industry, practitioners, and researchers.

Effects of ionizing radiation on cryogenic infrared detectors

Science.gov (United States)

Moseley, S. H.; Silverberg, R. F.; Lakew, B.

1989-01-01

The Diffuse Infrared Background Experiment (DIRBE) is one of three experiments to be carried aboard the Cosmic Background Explorer (COBE) satellite scheduled to be launched by NASA on a Delta rocket in 1989. The DIRBE is a cryogenic absolute photometer operating in a liquid helium dewar at 1.5 K. Photometric stability is a principal requirement for achieving the scientific objectives of this experiment. The Infrared Astronomy Satellite (IRAS), launched in 1983, which used detectors similar to those in DIRBE, revealed substantial changes in detector responsivity following exposure to ionizing radiation encountered on passage through the South Atlantic Anomaly (SAA). Since the COBE will use the same 900 Km sun-synchronous orbit as IRAS, ionizing radiation-induced performance changes in the detectors were a major concern. Here, ionizing radiation tests carried out on all the DIRBE photodetectors are reported. Responsivity changes following exposure to gamma rays, protons, and alpha particle are discussed. The detector performance was monitored following a simulated entire mission life dose. In addition, the response of the detectors to individual particle interactions was measured. The InSb photovoltaic detectors and the Blocked Impurity Band (BIB) detectors revealed no significant change in responsivity following radiation exposure. The Ge:Ga detectors show large effects which were greatly reduced by proper thermal annealing.

Cytotoxic Effects of Ionizing Radiation and Chlorpyrifos on White Rats

International Nuclear Information System (INIS)

El-Bahkery, A.M.L.H.

2014-01-01

The hazard of accidental exposure to ionizing radiation (IR) and/or neurotoxic insecticides like the organophosphorus insecticide chlorpyrifos (CPF) represent series health problem for human. In the present work, the cytotoxic effects of ionizing radiation and chlorpyrifos on rats were studied where animals were under glutathione (GSH) depletion. Animals were pre-treated with single dose of Buthionine Sulfoximine (BSO) (200 mg/kg body weight, by oral intubation), then treated with high dose of CPF (30 mg/kg body weight) and or exposure to IR (single dose of 6 Gy whole body gamma ray) one hour after BSO treatment. Another groups of animals pertreated with N-acetyl cystiene (NAC) one hour before treated with CPF and/or IR. After 24 hours blood sample, liver and brain were taken and used for estimate the GSH level and the activities of glutathione-stransferase (GST), glutathione reductase (GR), acetyl cholinesterase (AChE), carboxyl esterase (CE), paraoxonase (PON) and arylesterase (AE). Also, native PAGE electrophoresis was undertaken for separating the CE and PON isozymes in plasma, liver and brain. The results indicated that CPF produced no change in GSH level. Whereas, treatment with either BSO or IR, produced decrease in GSH level. NAC restored GSH level near the control level in all treated groups CPF had no effect on GST activity and pretreatment with either BSO or NAC increased GST activity in CPF treated groups. Also, exposure to IR had no effect on GST activity. Whereas, IR in combination with CPF and/or NAC and/or BSO produced inhibition in plasma GST activity and increased liver GST activity. In addition, both CPF and IR had no effect on the activity of GR. Whereas, pre-treatment with either BSO or NAC produced inhibition in plasma and liver GR activity in CPF treated groups. No change had observed in the IR exposed groups. Treatment with CPF inhibited AChE activity in plasma, liver and brain. Whereas, exposure to IR inhibited AChE activity in brain only

Ionizing radiation accidents. Data interpretation

International Nuclear Information System (INIS)

Cascon, Adriana S.

2003-01-01

After a general outlook of the biological effects at the cellular and molecular level, the somatic effects of the ionizing radiation are described. Argentine regulations and the ICRP recommendations on radiological protection of professionally exposed workers are also summarized. The paper includes practical advices for the physician that has to take care of an irradiated patient

Stimulating effects of ionizing radiation

International Nuclear Information System (INIS)

Jaworowski, Z.

1995-01-01

The influence of low doses on human organism is not definite known up to now. The worldwide discussion on this topic has been presented. A lot of analysed statistical data proved that the stimulating effect of low doses of ionizing radiation really exists and can have a beneficial influence on human health. 43 refs, 4 figs, 6 tabs

Regulation of glycogen synthase kinase-3β (GSK-3β) after ionizing radiation

International Nuclear Information System (INIS)

Boehme, K.A.

2006-12-01

Glycogen Synthase Kinase-3β (GSK-3β) phosphorylates the Mdm2 protein in the central domain. This phosphorylation is absolutely required for p53 degradation. Ionizing radiation inactivates GSK-3β by phosphorylation at serine 9 and in consequence prevents Mdm2 mediated p53 degradation. During the work for my PhD I identified Akt/PKB as the kinase that phosphorylates GSK-3β at serine 9 after ionizing radiation. Ionizing radiation leads to phosphorylation of Akt/PKB at threonine 308 and serine 473. The PI3 Kinase inhibitor LY294002 completely abolished Akt/PKB serine 473 phosphorylation and prevented the induction of GSK-3β serine 9 phosphorylation after ionizing radiation. Interestingly, the most significant activation of Akt/PKB after ionizing radiation occurred in the nucleus while cytoplasmic Akt/PKB was only weakly activated after radiation. By using siRNA, I showed that Akt1/PKBa, but not Akt2/PKBβ, is required for phosphorylation of GSK- 3β at serine 9 after ionizing radiation. Phosphorylation and activation of Akt/PKB after ionizing radiation depends on the DNA dependent protein kinase (DNA-PK), a member of the PI3 Kinase family, that is activated by free DNA ends. Both, in cells from SCID mice and after knockdown of the catalytic subunit of DNA-PK by siRNA in osteosarcoma cells, phosphorylation of Akt/PKB at serine 473 and of GSK-3β at serine 9 was completely abolished. Consistent with the principle that phosphorylation of GSK-3 at serine 9 contributes to p53 stabilization after radiation, the accumulation of p53 in response to ionizing radiation was largely prevented by downregulation of DNA-PK. From these results I conclude, that ionizing radiation induces a signaling cascade that leads to Akt1/PKBa activation mediated by DNA-PK dependent phosphorylation of serine 473. After activation Akt1/PKBa phosphorylates and inhibits GSK-3β in the nucleus. The resulting hypophosphorylated form of Mdm2 protein is no longer able to degrade p53 which in

The Assessment of Primary DNA Damage in Medical Personnel Occupationally Exposed to Ionizing Radiation

International Nuclear Information System (INIS)

Kopjar, N.; Garaj-Vrhovac, V.

2003-01-01

alkaline comet assay was selected. Working in the presence of ionizing radiation is one of many managed risks within a hospital. Among individuals occupationally exposed to ionizing radiation different cytogenetic changes, for example increased frequencies of chromosome aberrations and micronuclei are well known. Lesions induced by ionizing radiation in DNA can be also detected by comet assay. The increased comet values measured in peripheral blood leukocytes of exposed subjects indicate highly significant levels of primary radiation-induced DNA damage compared to control. However, the influences of the different occupational settings and doses absorbed on the levels of DNA damage in majority of subjects might be excluded. In the present study smoking habit did not significantly increased the levels of primary DNA damage both in control and exposed subjects. Cigarette smoking was not a very potent confounding factor on the comet parameters measured. The results indicate that the alkaline comet assay might be useful additional complement to standard biodosimetric methods. By detection of momentary DNA damage and/or repair activity, it reflects the concurrent exposure and the actual levels of DNA damage present in peripheral blood leukocytes of the radiological workers at the moment of blood sampling.(author)

29 CFR 570.57 - Exposure to radioactive substances and to ionizing radiations (Order 6).

Science.gov (United States)

2010-07-01

... to Their Health or Well-Being § 570.57 Exposure to radioactive substances and to ionizing radiations... radioactive substances and to ionizing radiations are particularly hazardous and detrimental to health for... involves exposure to ionizing radiations in excess of 0.5 rem per year. (b) Definitions. As used in this...

Applications of ionizing radiation for monuments conservation

International Nuclear Information System (INIS)

Chyzewski, M.; Galant, S.; Perkowski, J.

1996-01-01

Ionizing radiation can be used for conservation of monuments and old art objects. The irradiation of wooden and cellulose objects for disinfestation has been described. The irradiation conditions and lethal doses in respect to different species have been discussed. The different technique is the radiation consolidation of historical objects made of various materials. The method consists in radiation polymerization. The object undergoing conservation is saturated with monomer prior irradiation. The radiation polymerization results in consolidation of the object pieces and reinforcement of its material. 3 figs

Low doses effects of ionizing radiation on Saccharomyces cerevisiae

International Nuclear Information System (INIS)

Durand, J.; Broock, M. van; Gillette, V.H.

2000-01-01

The exposure of living cells to low doses of ionizing radiation induce in response the activation of cellular protection mechanisms against subsequent larger doses of radiation. This cellular adaptive response may vary depending on radiation intensity and time of exposure, and also on the testing probes used whether they were mammalian cells, yeast, bacteria and other organisms or cell types. The mechanisms involved are the genome activation, followed by DNA repair enzymes synthesis. Due to the prompt cell response, the cell cycle can be delayed, and the secondary detoxification of free radicals and/or activation of membrane bound receptors may proceed. All these phenomena are submitted to intense scientific research nowadays, and their elucidation will depend on the complexity of the organism under study. In the present work, the effects of low doses of ionizing radiation (gamma rays) over a suspension of the yeast Saccharomyces cerevisiae (Baker's yeast) was studied, mainly in respect to survival rate and radio-adaptive response. At first, the yeast surviving curve was assessed towards increasing doses, and an estimation of Lethal Dose 50 (LD50) was made. The irradiation tests were performed at LINAC (electrons Linear Accelerator) where electron energy reached approximately 2.65 MeV, and gamma-radiation was produced for bremsstrahlung process over an aluminium screen target. A series of experiments of conditioning doses was performed and an increment surviving fraction was observed when the dose was 2.3 Gy and a interval time between this and a higher dose (challenging dose) of 27 Gy was 90 minutes. A value of 58 ± 4 Gy was estimated for LD50, at a dose rate of 0.44 ± 0.03 Gy/min These quantities must be optimized. Besides data obtained over yeast survival, an unusual increasing amount of tiny yeast colonies appeared on the agar plates after incubation, and this number increased as increasing the time exposure. Preliminary results indicate these colonies as

Counseling Patients Exposed to Ionizing Radiation in Diagnostic Radiology During Pregnancy

International Nuclear Information System (INIS)

Brnic, Z.; Leder, N.I.; Popic Ramac, J.; Vidjak, V.; Knezevic, Z.

2013-01-01

There are many false assumptions regarding influence of radiation on pregnant patients and fetus during diagnostic procedures in spite of scientific facts based on studies (both in general population and among physicians). These false assumptions are mostly based on the idea that every diagnostic procedure that uses ionizing radiation is a cause for serious concern and consideration for artificial abortion as a possible solution. We have analysed the data of counselling of pregnant patients exposed to ionizing radiation during diagnostic procedures in University Hospital Merkur, during a period of four years. In this period we had 26 patients come in counselling due to exposure to ionizing radiation during pregnancy. Results show that most of these patients have been exposed to radiation between 2nd and 3rd week of gestation (36 %), between 4th and 5th week - 32 %; before 2nd week - 24%; and after 6th week of gestation less than 8 %. Average doses were: up to 0.01 cGy in 46.2 % patients; 0.01 - 0.15 cGy in 19.2 % patients; 0.2 - 1 cGy in 26.9 % and 1 cGy or more in 7.7 % of patients. No one of the counselled patients had a medical indication for abortion, even though in a small percentage of patients abortion was a personal subjective decision. Considering that there are no Croatian guidelines for counselling patients exposed to ionizing radiation during pregnancy, recommendation is to use International Commission on Radiological Protection (ICRP) guidelines for management of pregnant patients exposed to ionizing radiation.(author)

Guideline on radiation protection requirements for ionizing radiation shielding in nuclear power plants

International Nuclear Information System (INIS)

1988-01-01

The guideline which entered into force on 1 May 1988 stipulates the radiation protection requirements for shielding against ionizing radiation to be met in the design, construction, commissioning, operation, and decommissioning of nuclear power plants

Regulations on the prevention of ionizing radiation hazards

International Nuclear Information System (INIS)

1977-01-01

In accordance with the Law on Health and Safety at Work (Law No. 57, 1972) the regulations require any employer who runs an undertaking performing radiation-related works (hereinafter called ''the employer'') to protect his employees from ionizing radiation hazards. Chapter 1 (general provisions) gives the definitions of such technical terms as the ionizing radiations, the radioactive substances and the radiation-related works. Chapter 2 defines the controlled areas and the tolerance doses of radiation exposures. The controlled areas mean the areas within which the employer is required: to control the radiation doses; to prohibit access thereto of anyone other than who are necessary there; not to cause any person who is engaged there in the radiation-related works to be exposed to the radiation dose more than 3 rem within 3 months and any other person who has access regularly thereto to be exposed to more than 1.5 rem within a year; and to build special rooms for containing prescribed radiation-related appliances or apparatus. Chapter 4 requires the employer to build special working rooms for the treatment of such radioactive substances that are not sealed up tightly, and also prescribes the requirements concerning the construction of such rooms. (Matsushima, A.)

Simulation of the saturation curve of the ionization chamber in overlapping pulsed radiation

International Nuclear Information System (INIS)

Park, Se Hwan; Kim, Yong Kyun; Kim, Han Soo; Kang, Sang Mook; Ha, Jang Ho

2006-01-01

Procedures for determination of collection efficiency in ionization chambers have been studied by numerous investigators. If the theoretical approach for air-filled ionization chambers exposed to continuous radiation is considered, the result in the near-saturation region is a linear relationship between ) (1/I(V) vs 1/V 2 , where I(V) is the current measured with the ionization chamber at a given polarization voltage V . For pulsed radiation beams, Boag developed a model and the resulted in a linear relationship between ) (1/I(V) and 1/V when the collection efficiency, f , is larger than 0.9. The assumption of the linear relationship of ) (1/I(V) with 1/V or 1/V 2 in the near-saturation region makes the determination of the saturation current simple, since the linear relationship may be determined with only two measured data points. The above discussion of the collection efficiency of the ionization chamber exposed to the pulsed radiation is valid only if each pulse is cleared before the next one occurs. The transit times of the ions in the chamber must be shorter than the time interval between the radiation pulses. Most of the previous works concerning the characteristics of the saturation curve of an ionization chamber in the pulsed beam were done for the case where the transit times of the ions were shorter than the interval between the radiation pulses. However, the experimental data for the intermediate case, where the ion transit time was comparable to the interval between the radiation pulses or the ion transit time was slightly longer than the interval between the radiation pulses, were rare. The saturation curves of the ionization chambers in the pulsed radiation were measured with the pulse beamed electron accelerator at the Korea Atomic Energy Research Institute (KAERI), where the ion transit times in the ionization chambers were longer than the time interval between the radiation pulses. We used two ionization chambers: one was a commercial thimble

Exposure of pregnant women to ionizing radiation in hospitals

International Nuclear Information System (INIS)

Deschamps, S.

1996-01-01

Occupational health physicians often face the problem of whether to keep pregnant women at work in hospitals where they risk exposure to ionizing radiation. Current legislation requires that doctors ensure a certain level of safety for the embryo and the fetus. The current rules are unsatisfactory, however, because women are not obliged to declare that they are pregnant until the third month, which is one month past the period when he fetus is most sensitive to ionizing radiation. (author). 15 refs

Morphology and steroidogenesis of cultured granulosa cells obtained from ovaries of women treated with ionizing radiation

International Nuclear Information System (INIS)

Skrzypczak, J.

1997-01-01

The object of the study was the morphology and steroidogenesis of cultured granulosa cells obtained from 6 women aged 28-39 years who, because of Ib cervix carcinoma, were treated with ionizing radiation and later underwent surgery. It was observed that the granulosa cells were viable, had strong proliferative ability, and formed a monolayer on day 2 of culture. Contrary to our expectations, these cells produced larger amounts of steroids in culture than the control cells harvested from normal ovaries in late follicular phase. It was also found that the cells treated with ionizing radiation responded to exogenous gonadotropins with higher production of progesterone and estradiol than the controls. It is concluded that the increase in metabolic activity by granulosa cells from ovaries which had been indirectly affected by ionizing radiation is manifested by the stimulating influence of radiation on steroidogenesis. (author)

Effects of ionizing radiation on aquatic organisms and ecosystems

International Nuclear Information System (INIS)

1976-01-01

A panel of experts in November 1971 specifically considered the effects of ionizing radiation on aquatic organisms and ecosystems and formulated detailed suggestions for research in the area. A further panel meeting took place in April 1974. The results of the work are presented in this report which is divided into 3 chapters in the first chapter the concentrations of natural and artificial radionuclides in aquatic environments and the radiation dose rates received by aquatic organisms are discussed. In particular, simple dosimetry models for phytoplankton, zooplankton, mollusca, crustacea and fish are presented which permit the estimation of the dose rates from incorporated radionuclides and from radionuclides in the external environment. In the second chapter the somatic and genetic effects of ionizing radiation on aquatic organisms are reviewed. Somatic effects are discussed separately as effects due to short-term (acute) exposure to near-lethal doses of radiation. Great attention is paid to the effects due to long-term (chronic) exposure at lower doses rates. Consideration is given to behaviour, repair mechanisms and metabolic stimulation after exposure, and also the influence of environmental factors on radiation effects. In the third chapter the potential effects of low-level irradiation on aquatic populations are considered. First, the possible consequences of somatic effects on egg and larval mortality, stock-recruitment, fecundity and ecosystem stability are discussed. Subsequently, the assessment of genetic effects as they relate to population genetics and increased mutation rates are considered

Non-ionizing radiations : physical characteristics, biological effects and health hazard assessment

International Nuclear Information System (INIS)

Repacholi, M.H.

1988-01-01

The Workshop was a project of the International Non-Ionizing Radiation Committee of IRPA and comprised a series of educational lectures and demonstrations intended to give a comprehensive overview of non-ionizing electromagnetic radiation: physical characteristics, sources of concern, levels of exposure, mechanisms of interaction and reported effects of these fields and radiations with biological tissues, human studies, health risk assessment, national and international standards and guidelines, and protective measures

Experience with qualification examinations of workers handling ionizing radiation sources

International Nuclear Information System (INIS)

Skokanova, K.