WorldWideScience

Sample records for 50-year-old linear-no-threshold radiation

  1. Linear No-Threshold Model VS. Radiation Hormesis

    Doss, Mohan

    2013-01-01

    The atomic bomb survivor cancer mortality data have been used in the past to justify the use of the linear no-threshold (LNT) model for estimating the carcinogenic effects of low dose radiation. An analysis of the recently updated atomic bomb survivor cancer mortality dose-response data shows that the data no longer support the LNT model but are consistent with a radiation hormesis model when a correction is applied for a likely bias in the baseline cancer mortality rate. If the validity of t...

  2. Test of the linear, no threshold, theory of radiation carcinogenesis

    Cancer risks from low level radiation are always estimated using a linear theory, assuming that risk is proportional to exposure. Author aims to test that theory by studying the relationship between lung cancer risk and exposure to radon in homes. This paper shows a discrepancy with theory, that could be explained if there were a strong negative correlation between radon and smoking; i.e. if areas with low radon had much more smoking than areas with high radon. The author develops a quantitative treatment of this explanation. (author). 4 refs., 2 figs

  3. Does Imaging Technology Cause Cancer? Debunking the Linear No-Threshold Model of Radiation Carcinogenesis.

    Siegel, Jeffry A; Welsh, James S

    2016-04-01

    In the past several years, there has been a great deal of attention from the popular media focusing on the alleged carcinogenicity of low-dose radiation exposures received by patients undergoing medical imaging studies such as X-rays, computed tomography scans, and nuclear medicine scintigraphy. The media has based its reporting on the plethora of articles published in the scientific literature that claim that there is "no safe dose" of ionizing radiation, while essentially ignoring all the literature demonstrating the opposite point of view. But this reported "scientific" literature in turn bases its estimates of cancer induction on the linear no-threshold hypothesis of radiation carcinogenesis. The use of the linear no-threshold model has yielded hundreds of articles, all of which predict a definite carcinogenic effect of any dose of radiation, regardless of how small. Therefore, hospitals and professional societies have begun campaigns and policies aiming to reduce the use of certain medical imaging studies based on perceived risk:benefit ratio assumptions. However, as they are essentially all based on the linear no-threshold model of radiation carcinogenesis, the risk:benefit ratio models used to calculate the hazards of radiological imaging studies may be grossly inaccurate if the linear no-threshold hypothesis is wrong. Here, we review the myriad inadequacies of the linear no-threshold model and cast doubt on the various studies based on this overly simplistic model. PMID:25824269

  4. Low-level radiation exposures: time to revisit linear no-threshold concept

    The concepts of LNT (Linear No-Threshold) and the resulting ALARA (As Low As Reasonably Achievable) used for radiological protection have been stumbling blocks for public acceptability of nuclear power. Often, public get confused and easily get exploited by interested people. The application of this concept has perhaps resulted in a more harmful phenomenon now known as 'radiophobia'. Over the years, LNT has become the corner stone of radiation protection philosophy for the international organizations like ICRP, UNSCEAR etc. which is followed by all national regulators. The genesis of these theories is the cellular level findings of half a century back. Most of these are findings at high dose levels in macro systems and extrapolated to low dose. It is time that international radiation safety organizations revisit the assumptions and have a more pragmatic approach towards these abstract concepts in the light of new findings. The article reviews the evolution of LNT hypothesis and the basis for LNT, examines the possibility that there might be a threshold dose, below which there would be no radiation-related cancer risk. Evidences against LNT and the possible existence of a threshold dose are reviewed. The article concludes that this is definitely time to have a re-look of the corner stone concepts in radiation protection philosophy. (author)

  5. Test of the linear-no threshold theory of radiation carcinogenesis for inhaled radon decay products

    Data on lung cancer mortality rates vs. average radon concentration in homes for 1,601 U.S. counties are used to test the linear-no threshold theory. The widely recognized problems with ecological studies, as applied to this work, are addressed extensively. With or without corrections for variations in smoking prevalence, there is a strong tendency for lung cancer rates to decrease with increasing radon exposure, in sharp contrast to the increase expected from the theory. The discrepancy in slope is about 20 standard deviations. It is shown that uncertainties in lung cancer rates, radon exposures, and smoking prevalence are not important and that confounding by 54 socioeconomic factors, by geography, and by altitude and climate can explain only a small fraction of the discrepancy. Effects of known radon-smoking prevalence correlations - rural people have higher radon levels and smoke less than urban people, and smokers are exposed to less radon than non-smokers - are calculated and found to be trivial. In spite of extensive efforts, no potential explanation for the discrepancy other than failure of the linear-no threshold theory for carcinogenesis from inhaled radon decay products could be found. (author)

  6. A test of the linear-no threshold theory of radiation carcinogenesis

    It has been pointed out that, while an ecological study cannot determine whether radon causes lung cancer, it can test the validity of a linear-no threshold relationship between them. The linear-no threshold theory predicts a substantial positive correlation between the average radon exposure in various counties and their lung cancer mortality rates. Data on living areas of houses in 411 counties from all parts of the United States exhibit, rather, a substantial negative correlation with the slopes of the lines of regression differing from zero by 10 and 7 standard deviations for males and females, respectively, and from the positive slope predicted by the theory by at least 16 and 12 standard deviations. When the data are segmented into 23 groups of states or into 7 regions of the country, the predominantly negative slopes and correlations persist, applying to 18 of the 23 state groups and 6 of the 7 regions. Five state-sponsored studies are analyzed, and four of these give a strong negative slope (the other gives a weak positive slope, in agreement with our data for that state). A strong negative slope is also obtained in our data on basements in 253 counties. A random selection-no charge study of 39 high and low lung cancer counties (+4 low population states) gives a much stronger negative correlation. When nine potential confounding factors are included in a multiple linear regression analysis, the discrepancy with theory is reduced only to 12 and 8.5 standard deviations for males and females, respectively. When the data are segmented into four groups by population, the multiple regression vs radon level gives a strong negative slope for each of the four groups. Other considerations are introduced to reduce the discrepancy, but it remains very substantial

  7. Effects at exposure to low doses of ionising radiation. Carcinogenic effect - validity of the linear no-threshold model

    The paper considers the validity of the linear no-threshold model (LNT) for estimating the risk related to low (below 200 mSv) and very low (below 10 mSv) doses. LNT was launched in the early 60s aiming mainly at data registering and radiation protection (RP) measures, since it allows the estimation of the risk just by summing all radiation exposures regardless of the dose and dose rates. In 1965 the International Commission on Radiological Protection (ICRP) stated its position: 'As the existence of a threshold dose is unknown it has been assumed that even the smallest doses involve a proportionately small risk of induction of malignancies. Also, because of the lack of knowledge of the nature of the dose-effect relationship in the induction of malignancies in man - particularly at the dose levels which are relevant in radiological protection - the Commission sees no practical alternative, for the purposes of radiological protection, to assuming non-linear relationship between dose and effect, and that doses act cumulatively. The Commission is aware that the assumptions of no-threshold and of complete ditivity of all doses, but is satisfied that they are unlikely to lead to the underestimation of risks'. In the end of the 70s the discovery of oncogenes was interpreted as a scientific basis of this hypothesis, since only one mutation can transform a proto-oncogene into an oncogene. Meanwhile, LNT validity was questioned by many radiobiologists. The doubts were related to the scientific basis of LNT especially as regards very low doses. This debate is of great importance because the major aim of radiation protection is to estimate the risk related to doses of the order of few mSv, and these are the doses which are received in most of the medical examinations and which are comparable to values from the natural radiation background

  8. Surveys of radon levels in homes in the United States: A test of the linear-no-threshold dose-response relationship for radiation carcinogenesis

    The University of Pittsburgh Radon Project for large scale measurements of radon concentrations in homes is described. Its principal research is to test the linear-no threshold dose-response relationship for radiation carcinogenesis by determining average radon levels in the 25 U.S. counties (within certain population ranges) with highest and lowest lung cancer rates. The theory predicts that the former should have about 3 times higher average radon levels than the latter, under the assumption that any correlation between exposure to radon and exposure to other causes of lung cancer is weak. The validity of this assumption is tested with data on average radon level vs replies to items on questionnaires; there is little correlation between radon levels in houses and smoking habits, educational attainment, or economic status of the occupants, or with urban vs rural environs which is an indicator of exposure to air pollution

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

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

  10. Is the Linear No-Threshold Dose-Response Paradigm Still Necessary for the Assessment of Health Effects of Low Dose Radiation?

    Seong, Ki Moon; Seo, Songwon; Lee, Dalnim; Kim, Min-Jeong; Lee, Seung-Sook; Park, Sunhoo; Jin, Young Woo

    2016-02-01

    Inevitable human exposure to ionizing radiation from man-made sources has been increased with the proceeding of human civilization and consequently public concerns focus on the possible risk to human health. Moreover, Fukushima nuclear power plant accidents after the 2011 East-Japan earthquake and tsunami has brought the great fear and anxiety for the exposure of radiation at low levels, even much lower levels similar to natural background. Health effects of low dose radiation less than 100 mSv have been debated whether they are beneficial or detrimental because sample sizes were not large enough to allow epidemiological detection of excess effects and there was lack of consistency among the available experimental data. We have reviewed an extensive literature on the low dose radiation effects in both radiation biology and epidemiology, and highlighted some of the controversies therein. This article could provide a reasonable view of utilizing radiation for human life and responding to the public questions about radiation risk. In addition, it suggests the necessity of integrated studies of radiobiology and epidemiology at the national level in order to collect more systematic and profound information about health effects of low dose radiation. PMID:26908982

  11. 50-year-old history of the Korean physical society

    This book introduces the root of Korean physics, the dawning of Korean physics, foundation and childhood of Korean physics society, growth of Korean physics society, revival of Korean physics society, corporation Korean physics society, leap of Korean physics society and challenges towards future. It also deals with 50-year-old history of the Korean physical society according to committees, special interest groups, branches in cities and provinces, branches in universities, laboratories, society bureau, and commemoration business to celebrate 50th anniversary.

  12. 50-year-old history of the Korean physical society

    NONE

    2002-12-15

    This book introduces the root of Korean physics, the dawning of Korean physics, foundation and childhood of Korean physics society, growth of Korean physics society, revival of Korean physics society, corporation Korean physics society, leap of Korean physics society and challenges towards future. It also deals with 50-year-old history of the Korean physical society according to committees, special interest groups, branches in cities and provinces, branches in universities, laboratories, society bureau, and commemoration business to celebrate 50th anniversary.

  13. Molecular biology, epidemiology, and the demise of the linear no-threshold (LNT) hypothesis

    The prime concern of radiation protection policy since 1959 has been protecting DNA from damage. The 1995 NCRP Report 121 on collective dose stases that since no human data provides direct support for the linear no threshold hypothesis (LNT), and some studies provide quantitative data that, with statistical significance, contradict LNT, ultimately, confidence in LNT is based on the biophysical concept that the passage of a single charged particle could cause damage to DNA that would result in cancer. Current understanding of the basic molecular biologic mechanisms involved and recent data are examined before presenting several statistically significant epidemiologic studies that contradict the LNT hypothesis. Over eons of time a complex bio-system evolved to control the DNA alterations (oxidative adducts) produced by about 1010 free radicals/cell/d derived from 2-3 % of all metabolized oxygen. Antioxidant prevention, enzymatic repair of DNA damage, and removal of persistent DNA alterations by apoptosis, differentiation, necrosis, and the immune system, sequentially reduce DNA damage from about 106 DNA alterations/cell/d to about 1 mutation/cell/d. These mutations accumulate in stem cells during a lifetime with progressive DNA damage-control impairment associated with aging and malignant growth. A comparatively negligible number of mutations, an average of about 10-7 mutations/cell/d, is produced by low LET radiation background of 0.1 cGy/y. The remarkable efficiency of this bio-system is increased by the adaptive responses to low-dose ionizing radiation. Each of the sequential functions that prevent, repair, and remove DNA damage are adaptively stimulated by long-dose ionizing radiation in contrast to their impairment by high-dose radiation. The biologic effect of radiation is not determined by the number of mutations it creates, but by its effect on the bio-system that controls the relentless enormous burden of oxidative DNA damage. At low doses, radiation

  14. Motivational interest of women of 30-50 years old to the studying of healthy exercises

    Sorokina S.O.; Kudryashova T.I.

    2011-01-01

    This article shows the actual problem, which is not so frequently in the publications of scientific-methodical literature, namely, the identification of motivations to attend to fitness physical exercises women of 30-50 years old. The article considers the level of interest of women30-50 years old to healthy physical exercises, and their attitude to the health and other aspects of activity. The current situation in this matter was analyzed and was planed the possible ways of formation the wom...

  15. A 50-Year-Old Woman Addicted to Heroin: Review of Treatment of Heroin Addiction

    O’Brien, Charles P.

    2008-01-01

    Heroin addiction is a complicated medical and psychiatric issue, with well-established as well as newer modes of treatment. The case of Ms W, a 50-year-old woman with a long history of opiate addiction who has been treated successfully with methadone for 9 years and who now would like to consider newer alternatives, illustrates the complex issues of heroin addiction. The treatment of heroin addiction as a chronic disease is reviewed, including social, medical, and cultural issues and pharmaco...

  16. Effects of thinning intensities on transpiration and productivity of 50-year-old Pinus koraeinsis stands

    Park, J.; Kim, T.; Cho, S.; Ryu, D.; Moon, M.; Kim, H. S.

    2015-12-01

    This study investigated the effects of thinning intensities on stand transpiration and productivity of 50-year-old Korean pine forests for three years. Forest thinning, which remove some fraction of trees from stand, alters the microclimatic conditions such as radiation distribution within canopy, vapor pressure deficit, and amount of available soil water. These changes influence on the tree water use, and related tree growth. Thinning was conducted on March, 2012 with two intensities (Control, Light-thinning, and Heavy-thinning). Transpiration was estimated from sap flux density, which was measured with Granier-type thermal dissipation sensors. Tree diameter growth was measured with dendrometer, and converted to tree productivity using allometric equations developed specifically in our study sites.The climatic conditions showed remarkable differences among three years. In 2012, total precipitation was highest but spring was dry. 2013 was normal year with frequent rain events. In contrast, 2014 was hot and extremely dry. Stand transpiration was initially decreased ca. 20% and 42% on light-thinning and heavy-thinning stand, respectively. In second year, it gradually recovered in both thinning intensities, and was 19% and 37% lower on light-thinning and heavy-thinning stand, respectively. However, the recovery trends were different between two thinning intensities. Transpiration of heavy-thinning stand was recovered slowly than that of light thinning stand. In 2014, heavy-thinning stand transpired ca. 5% more than control plot in early growing season, but severe drought had negative effects that caused reduction of stand transpiration in thinned stand on late growing season. The tree-level productivity was increased initially ca. 24% and 28% on light-thinning and heavy-thinning stand, respectively. During the following growing seasons, this thinning-induced enhancement of productivity was diminished in light-thinning stand (21% in 2013 and 20% in 2014), but was

  17. Effects of thinning intensities on transpiration and productivity of 50-year-old Pinus koraeinsis stands

    Park, Juhan; Kim, Taekyu; Moon, Minkyu; Cho, Sungsik; Ryu, Daun; Kim, Hyun Seok

    2015-04-01

    This study investigated the effects of thinning intensities on stand transpiration and productivity of 50-year-old Korean pine forests for two years. Forest thinning, which removes some fraction of trees from stand, is widely conducted for reducing competition between remaining trees, improving tree productivity, reducing the risk of natural fire, and thus maintaining healthy forest. Forest thinning alters the microclimatic conditions such as radiation distribution within canopy, vapor pressure deficit, and amount of available soil water. These changes influence on the tree water use, and related productivity. Thinning was conducted on March, 2012 with two intensities (Control, Light-thinning (20%), and Heavy-thinning (40% of tree density)). Transpiration was estimated from sap flux density, which was measured with Granier-type thermal dissipation sensors. Tree diameter growth was measured with dendrometer, and converted to tree productivity using allometric equations developed specifically in our study sites. The climatic conditions showed little differences between two years. During the first growing season after thinning, stand transpiration was ca. 20% and 42% lower on light-thinning and heavy-thinning stand, respectively, even though sap flux density were higher in thinned stand. The difference in stand transpiration among treatments showed seasonal trends, so it was larger on summer when soil moisture was abundant due to monsoon, but was diminished on spring and autumn when soil moisture was limited. Tree-level productivity increased ca. 8% and 21% on light-thinning and heavy thinning stand, respectively. However, stand net primary production was ca. 20% lower on light-thinning stand, and ca. 31% on heavy-thinning stand. As a result, water use efficiency increased only in heavy-thinning stand. During the second growing season after thinning, stand transpiration was ca. 19% lower on light-thinning stand, and ca. 37% lower on heavy-thinning stand. The reduction

  18. [The 50-year-old women or older: preventive actions to the HIV infection].

    Rodrigues, Daniela Angelo de Lima; Praça, Neide de Souza

    2010-06-01

    The present study is a qualitative research which aimed to verify the adoption of preventive measures on the transmission of HIV in 50-year-old women or older, who lived in poor communities and were assisted by the Family Health Program in São Paulo, Brazil. Medical Anthropology has been adopted as a theoretical reference, as well as the Discourse of the Collective Individual for data analysis. Thirteen women were interviewed and three discourses were presented: prevention appreciation, invisibility of HIV/AIDS and the rejection of the use of condom. The analysis showed that the group did not realize the risk of contamination through sexual intercourse due to their trust in the partner's loyalty. The casual use of condoms was taken into consideration just out of curiosity. The preventive actions adopted need more scientific support. The results point out the necessity of planning and implementing interventions which are culturally based and directed to the studied segment. PMID:21500513

  19. Noninvasive assessment of cardiomyopathy in normotensive diabetic patients between 20 and 50 years old

    To further the understanding of diabetic heart disease, we tested the hypothesis that an asymptomatic group of normotensive diabetic patients between 20 and 50 years old had a restrictive cardiomyopathy independent of clinically significant coronary artery disease. Quantitative two-dimensional echocardiography and stress myocardial perfusion scintigraphy were performed to detect and characterize the cardiac abnormalities in this study group comprising 88 patients with rigorously classified diabetes and 65 volunteer control subjects. Diabetic patients were shown to have a mildly reduced left ventricular end-diastolic volume index: 50.1 +/- 8.2 and 52.1 +/- 14.7 mL/m2 for patients with type I and type II diabetes, respectively, versus 58.9 +/- 11.7 mL/m2 for control subjects. The left ventricular diastolic filling was also impaired in diabetic patients as reflected by a lower atrial emptying index: 0.73 +/- 0.24 and 0.76 +/- 0.3 for type I and type II diabetics, respectively, compared with 1.14 +/- 0.24 for control subjects. Exercise tolerance was normal in subjects with type I diabetes and slightly reduced in subjects with type II diabetes. Only one patient developed regional ischemia on thallium exercise testing. Using a comprehensive, noninvasive approach, we have shown that asymptomatic normotensive patients with type I or type II diabetes who were between 20 and 50 years old had a restrictive cardiomyopathy characterized by mildly reduced left ventricular end-diastolic volume and altered left ventricular compliance independent of critical coronary artery disease

  20. Effects of Growth Hormone Administration on Muscle Strength in Men over 50 Years Old

    A. B. W. Tavares

    2013-01-01

    Full Text Available Growth hormone (GH use has been speculated to improve physical capacity in subjects without GH deficiency (GHD through stimulation of collagen synthesis in the tendon and skeletal muscle, which leads to better exercise training and increased muscle strength. In this context, the use of GH in healthy elderly should be an option for increasing muscle strength. Our aim was to evaluate the effect of GH therapy on muscle strength in healthy men over 50 years old. Fourteen healthy men aged 50–70 years were evaluated at baseline for body composition and muscle strength (evaluated by leg press and bench press exercises, which focus primarily on quadriceps—lower body part and pectoralis major—upper body part—muscles, resp.. Subjects were randomised into 2 groups: GH therapy (7 subjects and placebo (7 subjects and reevaluated after 6 months of therapy. Thirteen subjects completed the study (6 subjects in the placebo group and 7 subjects in the GH group. Subjects of both groups were not different at baseline. After 6 months of therapy, muscle strength in the bench press responsive muscles did not increase in both groups and showed a statistically significant increase in the leg press responsive muscles in the GH group. Our study demonstrated an increase in muscle strength in the lower body part after GH therapy in healthy men. This finding must be considered and tested in frail older populations, whose physical incapacity is primarily caused by proximal muscle weakness. The trial was registered with NCT01853566.

  1. Multi-stratified multiple regression tests of the linear/no-threshold theory of radon-induced lung cancer

    A plot of lung-cancer rates versus radon exposures in 965 US counties, or in all US states, has a strong negative slope, b, in sharp contrast to the strong positive slope predicted by linear/no-threshold theory. The discrepancy between these slopes exceeds 20 standard deviations (SD). Including smoking frequency in the analysis substantially improves fits to a linear relationship but has little effect on the discrepancy in b, because correlations between smoking frequency and radon levels are quite weak. Including 17 socioeconomic variables (SEV) in multiple regression analysis reduces the discrepancy to 15 SD. Data were divided into segments by stratifying on each SEV in turn, and on geography, and on both simultaneously, giving over 300 data sets to be analyzed individually, but negative slopes predominated. The slope is negative whether one considers only the most urban counties or only the most rural; only the richest or only the poorest; only the richest in the South Atlantic region or only the poorest in that region, etc., etc.,; and for all the strata in between. Since this is an ecological study, the well-known problems with ecological studies were investigated and found not to be applicable here. The open-quotes ecological fallacyclose quotes was shown not to apply in testing a linear/no-threshold theory, and the vulnerability to confounding is greatly reduced when confounding factors are only weakly correlated with radon levels, as is generally the case here. All confounding factors known to correlate with radon and with lung cancer were investigated quantitatively and found to have little effect on the discrepancy

  2. Problems in the radon versus lung cancer test of the linear no-threshold theory and a procedure for resolving them

    It has been shown that lung cancer rates in U.S. counties, with or without correction for smoking, decrease with increasing radon exposure, in sharp contrast to the increase predicted by the linear-no-threshold (LNT) theory. The discrepancy is by 20 standard deviations, and very extensive efforts to explain it were not successful. Unless a plausible explanation for this discrepancy (or conflicting evidence) can be found, continued use of the LNT theory is a violation of open-quotes the scientific method.close quotes Nevertheless, LNT continues to be accepted and used by all official and governmental organizations, such as the International Commission on Radiological Protection, the National Council on Radiation Protection and Measurements, the Council on Radiation Protection and Measurements, the National Academy of Sciences - U.S. Nuclear Regulatory Commission Board of Radiation Effects Research, Environmental Protection Agency etc., and there has been no move by any of these bodies to discontinue or limit its use. Assuming that they rely on the scientific method, this clearly implies that they have a plausible explanation for the discrepancy. The author has made great efforts to discover these 'plausible explanations' by inquiries through various channels, and the purpose of this paper is to describe and discuss them

  3. Disease Burden Due to Herpes Zoster among Population Aged ≥50 Years Old in China: A Community Based Retrospective Survey

    Yin, Dapeng; Liu, Yanmin; Huang, Zhuoying; Xu, Jianfang; Ma, Yujie; Tu, Qiufeng; Li, Qi; Wang, Huaqing

    2016-01-01

    Objective To understand the disease burden due to Herpes Zoster (HZ) among people aged ≥50 years old in China and provide baseline data for future similar studies, and provide evidence for development of herpes zoster vaccination strategy. Methods Retrospective cohort study was conducted in 4 townships and one community. A questionnaire was used to collect information on incidence and cost of HZ among people aged ≥ 50 years old. Results The cumulative incidence rate was 22.6/1,000 among people aged ≥ 50 years old. The average annual incidence rate of HZ was 3.43/1,000 among people aged ≥ 50 years old in 2010–2012. Cumulative incidence and average annual incidence rate increased with age: the cumulative incidence of HZ among people aged ≥ 80 years old was 3.34 times of that among 50- years old (52.3/1000vs15.7/1,000); average annual incidence rate rises from 2.66/1,000 among 50- years old to 8.55/1,000 among 80- year old. Cumulative incidence and average annual incidence rate for females were higher than that for males (cumulative incidence, 26.5/1000vs18.7/1,000; annual incidence rate, 3.95/1000vs2.89/1,000). Cumulative incidence and average annual incidence rate in urban were higher than in rural (cumulative incidence, 39.5/1000vs 17.2/1,000; annual incidence rate, 7.65/1000vs2.06/1,000). The hospitalization rate of HZ was 4.53%. And with the increase of age, the rate has an increasing trend. HZ costs 945,709.5 RMB in total, corresponding to 840.6 RMB per patient with a median cost of 385 RMB (interquartile range 171.7–795.6). Factors associated with cost included the first onset year, area, whether hospitalized and whether sequelae left. Conclusion Incidence rate, complications, hospitalization rate and average cost of HZ increase with age. We recommend that the HZ vaccinations should target people aged ≥50 years old if Zoster vaccine is licensed in China. PMID:27055179

  4. Multiorgan involvements of cowden disease in 50-year-old woman: A case report and literature overview

    Cowden disease is the prototype of phosphate and, tensin homologue deleted on the chromosome 10 (PTEN) hamartoma tumor syndrome caused by germline mutations in the tumor suppressor PTEN, which is characterized by multiple developmentally disorganized benign growths, hamartomas, with an increased risk of both benign and malignant tumors. We present another case of Cowden disease in a 50-year-old woman. Besides the diagnostic criteria of Cowden disease, she had various manifestations in thyroid, lung, spleen, liver, pancreas, and muscle. As far as we know, it is the first case showing radiographic findings of hamartomatous lesions in thyroid, spleen, and pancreas, associated with Cowden disease.

  5. Multiorgan involvements of cowden disease in 50-year-old woman: A case report and literature overview

    Lee, Eun Jae; Jung, Won Sang; Ko, Jeong Min; Park, Hyun Jin [Dept. of Radiology, St. Vincent' s Hospital, The Catholic University of Korea College of Medicine, Suwon (Korea, Republic of)

    2013-09-15

    Cowden disease is the prototype of phosphate and, tensin homologue deleted on the chromosome 10 (PTEN) hamartoma tumor syndrome caused by germline mutations in the tumor suppressor PTEN, which is characterized by multiple developmentally disorganized benign growths, hamartomas, with an increased risk of both benign and malignant tumors. We present another case of Cowden disease in a 50-year-old woman. Besides the diagnostic criteria of Cowden disease, she had various manifestations in thyroid, lung, spleen, liver, pancreas, and muscle. As far as we know, it is the first case showing radiographic findings of hamartomatous lesions in thyroid, spleen, and pancreas, associated with Cowden disease.

  6. Exogenous ochronosis after prolonged use of topical hydroquinone (2% in a 50-year-old Indian female

    Vijay Gandhi

    2012-01-01

    Full Text Available Ochronosis is a rare disease characterized by speckled and diffuse pigmentation symmetrically over the face, neck, and photo-exposed areas. It is characterized histologically by banana-shaped ochre-colored deposits in the dermis. It can present in exogenous or endogenous form. We report a case of exogenous ochronosis in a 50-year-old Indian woman after prolonged use of topical hydroquinone which is a rare complication with a commonly used drug which is available over the counter.

  7. Size of coarse woody debris 5 years after girdling and removal treatments in 50-year-old Loblolly PIne Plantations

    Edwards, M. Boyd [USDA Forest Service, Savannah River, New Ellenton, SC (United States)

    2004-01-01

    PP 108 -113 in: Connor, Kristina F., ed. 2004. Proceedings of the 12th biennial southern silvicultural research conference. Gen. Tech. Rep. SRS71. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. 594 p. Abstract: In 1996, a study began at Savannah River Site to investigate large-scale replicated forest areas to control coarse woody debris for integrated biodiversity objectives. Research design was a randomized complete block with four treatments replicated in four blocks, resulting in 16 plots. The treatments applied to 50-year-old loblolly pine stands were (1) control, (2) girdling of 25 percent of trees to create catastrophic simulation, (3) annual removal of down woody debris > 10 cm in diameter, and (4) annual removal of both standing and down woody debris > 10 cm in diameter. The study tracks coarse woody debris recruitment and loading, rates of decomposition, and effects on the forest ecosystem.

  8. Effect of adapted karate training on quality of life and body balance in 50-year-old men

    Marie-Ludivine Chateau-Degat

    2010-08-01

    Full Text Available Marie-Ludivine Chateau-Degat1, Gérard Papouin2, Philippe Saint-Val3, Antonio Lopez21Axe sante des populations et environmentale, CHUQ, Laval University, Quebec, Canada; 2Service de Cardiologie, Centre Hospitalier Territorial du Taone, 3Fédération Tahitienne de Karaté, Papeete, French PolynesiaBackground: Aging is associated with a decrease in physical skills, sometimes accompanied by a change in quality of life (QOL. Long-term martial arts practice has been proposed as an avenue to counter these deleterious effects. The general purpose of this pilot study was to identify the effects of an adapted karate training program on QOL, depression, and motor skills in 50-year-old men.Methods and design: Fifteen 50-year-old men were enrolled in a one-year prospective experiment. Participants practiced adapted karate training for 90 minutes three times a week. Testing sessions, involving completion of the MOS 36-item Short Form Health Survey (SF36 and Beck Depression Inventory, as well as motor and effort evaluation, were done at baseline, and six and 12 months.Results: Compared with baseline, participants had better Beck Depression Inventory scores after one year of karate training (P < 0.01 and better perception of their physical health (P < 0.01, but not on the mental dimension (P < 0.49. They also improved their reaction time scores for the nondominant hand and sway parameters in the eyes-closed position (P < 0.01.Conclusion: Regular long-term karate practice had favorable effects on mood, perception of physical health confirmed by better postural control, and improved performance on objective physical testing. Adapted karate training would be an interesting option for maintaining physical activity in aging.Keywords: karate, balance, training, sport, aging

  9. Seasonal incidence of medically attended respiratory syncytial virus infection in a community cohort of adults ≥50 years old.

    David L McClure

    Full Text Available BACKGROUND: Diagnostic testing for respiratory syncytial virus (RSV is not routinely performed in adults. We estimated medically attended RSV seasonal incidence in a community cohort of adults ≥50 years old during four influenza seasons (2006-07 through 2009-10. METHODS: Patients seeking care for acute respiratory illness (ARI were prospectively enrolled and tested for RSV by multiplex RT-PCR. Results from enrolled patients were used to estimate projected cases among non-enrolled patients with ARI. The seasonal incidence of medically attended RSV was the sum of actual and projected cases divided by the community cohort denominator. Since each enrollment period did not include the entire RSV season, incidence estimates were adjusted to account for the statewide proportion of RSV occurring outside the study enrollment period. RESULTS: There were 16,088 to 17,694 adults in the cohort each season and 164 RSV cases in all 4 seasons. The overall seasonal incidence of medically attended RSV was 154 episodes (95% CI, 132-180 per 10,000 persons; the incidence was highest in 2007-08 (179 and lowest in 2006-07 (110. Among persons 50-59, 60-69, and ≥70 years old, RSV incidence was 124 (95% CI, 99-156, 147 (95% CI, 110-196, and 199 (95% CI, 153-258, respectively. CONCLUSIONS: The incidence of medically attended RSV increased with age and was similar during four seasons.

  10. Atomic and nano-scale characterization of a 50-year-old hydrated C3S paste

    Geng, Guoqing

    2015-07-15

    This paper investigates the atomic and nano-scale structures of a 50-year-old hydrated alite paste. Imaged by TEM, the outer product C-S-H fibers are composed of particles that are 1.5-2 nm thick and several tens of nanometers long. 29Si NMR shows 47.9% Q1 and 52.1% Q2, with a mean SiO4 tetrahedron chain length (MCL) of 4.18, indicating a limited degree of polymerization after 50 years\\' hydration. A Scanning Transmission X-ray Microscopy (STXM) study was conducted on this late-age paste and a 1.5 year old hydrated C3S solution. Near Edge X-ray Absorption Fine Structure (NEXAFS) at Ca L3,2-edge indicates that Ca2 + in C-S-H is in an irregular symmetric coordination, which agrees more with the atomic structure of tobermorite than that of jennite. At Si K-edge, multi-scattering phenomenon is sensitive to the degree of polymerization, which has the potential to unveil the structure of the SiO44 - tetrahedron chain. © 2015 Elsevier Ltd. All rights reserved.

  11. A Case of a Solid Renal Mass Together with a Cystic Pancreatic Lesion in a 50-Year-Old Patient

    Satorres Rosas J

    2005-03-01

    Full Text Available CONTEXT: Pancreatic cysts may be incidentally detected in asymptomatic patients evaluated for other clinical manifestations. Microcystic adenomas are particularly rare among pancreatic cyst neoplasms. They are benign lesions and can present as solitary pancreatic tumors or as a radiological manifestation combined with other cystic and tumoral lesions affecting different organs. CASE REPORT: A 50-year-old man presented with hematuria. A computed tomography scan of the abdomen showed a 9-centimeter renal mass in the left kidney consistent with a renal-cell carcinoma as well as a cystic lesion the head of the pancreas. The histopathological study of the cystic mass, following a computed tomography guided biopsy, showed a microcystic adenoma. Therefore, further studies were performed so as to assess the relationship between both lesions and determine the final diagnosis. CONCLUSIONS: Microcystic adenomas are exceedingly rare tumors among pancreatic cysts. The combination of a solid renal mass and a pancreatic cystic lesion should lead to a broad differential diagnosis. Pancreatic magnetic resonance imaging has been proven to be particularly useful in evaluating cystic masses. The presence of walls and internal septations in the pancreatic mass with gadolinium enhancement should raise the possibility of an underlying Von Hippel-Lindau syndrome.

  12. The Profile of Fundamental Frequency Changes in Normal Persian-Speaking Individuals 9-50 Years Old

    Ali Ghorbani

    2011-12-01

    Full Text Available Background and Aim: The voice of human being changes during lifetime with different patterns in males and females. In addition to assessment of changes due to aging, some studies examined the voice changes among various languages and ethnical groups. This study is performed to evaluate the fundamental frequency changes in normal 9-50 year-old Persian (Farsi speaking individuals.Methods: In this cross-sectional study, 320 voice samples in normal voiceless environment were recorded. The mean of fundamental frequency of vowels and counting is measured by Dr Speech software (real analysis program. Data analysis was performed by MANOVA test and the profiles of their changes were plotted.Results: The profile of mean of fundamental frequency changes was different in males and females. The mean of fundamental frequency was equal in both genders until 13 years old and the samples of voice had low pitch (Mean: higher than 200 Hz. MFF after 13 years old significantly decreased in males specially in vowels (p<0.001. The changes in vowels and counting were similar. The mean of fundamental frequency in both genders, between 20-40 years old had relative constancy.Conclusion: The mean of fundamental frequency changes of vowels and counting in females and males result from diverse dimensions of larynx and other anatomical differences. Significant changes of mean of fundamental frequency in both genders after 13 years old result from puberty in males. The proportional consistence of mean of fundamental frequency between 20-40 years old is probably due to the uniformity of body in this age range.

  13. The impact of gentle body exercise on the metabolism of lipids in healthy people aged up to 50 years old with normal weight

    M. Ioannidou; I. Siochu; A. Siochu

    2007-01-01

    Aim: The aim of the current study was to determine whether gentle body exercise has a positive impact on the HDL and LDL levels of cholesterol and levels of trigyceryl in people aged up to 50 years old with normal body weight. Material and Method: The sample consisted of 40 healthy persons aged up to 50 years old with normal body weight, which they did not have a cardiovascular disease history, a diabetes history, or a hormonal disorder history. Furthermore, those people were found with high ...

  14. Socioeconomic position and variations in coping strategies in musculoskeletal pain: a cross-sectional study of 1,287 40- and 50-year-old men and women

    Christensen, Ulla; Schmidt, Lone; Hougaard, Charlotte Ørsted;

    2006-01-01

    OBJECTIVE: To examine the association between socioeconomic position and coping strategies in musculoskeletal pain. DESIGN AND SUBJECTS: Cross-sectional study of a random sample of 40- and 50-year-old Danes, participation rate 69%, n=7,125. The study included 1,287 persons who reported functional...... clinicians who advise and support patients in their response to musculoskeletal pain to be aware of socioeconomic differences in coping strategies. Gender differences in the association between socioeconomic factors and coping should be further investigated....

  15. General relativity 50 years old

    1966-01-01

    In May 1916, 'The Foundations of General Relativity Theory' by Albert Einstein was published in 'Annalen der Physik'. Fifty years later, this major contribution to scientific thought still has a rather isolated position with respect to the main-stream of scientific theory. (In contrast, the Special Theory of Relativity is one of the cornerstones of sub-nuclear physics.) To mark the anniversary of the publication of Einstein's paper a theoretician from CERN discusses the theory and its present status.

  16. Dairy Intake Enhances Body Weight and Composition Changes during Energy Restriction in 18–50-Year-Old Adults—A Meta-Analysis of Randomized Controlled Trials

    Stonehouse, Welma; Wycherley, Thomas; Luscombe-Marsh, Natalie; Taylor, Pennie; Brinkworth, Grant; Riley, Malcolm

    2016-01-01

    Background/Aims: A meta-analysis of randomized controlled trials (RCTs) was performed to investigate the effects of dairy food or supplements during energy restriction on body weight and composition in 18–50-year-old. Methods: RCTs ≥ 4 weeks comparing the effect of dairy consumption (whole food or supplements) with control diets lower in dairy during energy restriction on body weight, fat and lean mass were identified by searching MEDLINE, EMBASE, Pubmed, Cochrane Central and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) until March 2016. Reports were identified and critically appraised in duplicate. Data were pooled using random-effects meta-analysis. Chi2- and I2-statistics indicated heterogeneity. Dose effect was assessed using meta-regression analysis. GRADE guidelines were used to rate the quality (QR) of the evidence considering risk of bias, inconsistency, indirectness, imprecision, publication bias and effect estimates. Results: 27 RCTs were reviewed. Participants consumed between 2 and 4 standard servings/day of dairy food or 20–84 g/day of whey protein compared to low dairy control diets, over a median of 16 weeks. A greater reduction in body weight (−1.16 kg [−1.66, −0.66 kg], p < 0.001, I2 = 11%, QR = high, n = 644) and body fat mass (−1.49 kg [−2.06, −0.92 kg], p < 0.001, I2 = 21%, n = 521, QR = high) were found in studies largely including women (90% women). These effects were absent in studies that imposed resistance training (QR = low-moderate). Dairy intake resulted in smaller loss of lean mass (all trials pooled: 0.36 kg [0.01, 0.71 kg], p = 0.04, I2 = 64%, n = 651, QR = moderate). No between study dose-response effects were seen. Conclusions: Increased dairy intake as part of energy restricted diets resulted in greater loss in bodyweight and fat mass while attenuating lean mass loss in 18–50-year-old adults. Further research in males is needed to investigate sex effects. PMID:27376321

  17. Dairy Intake Enhances Body Weight and Composition Changes during Energy Restriction in 18–50-Year-Old Adults—A Meta-Analysis of Randomized Controlled Trials

    Welma Stonehouse

    2016-07-01

    Full Text Available Background/Aims: A meta-analysis of randomized controlled trials (RCTs was performed to investigate the effects of dairy food or supplements during energy restriction on body weight and composition in 18–50-year-old. Methods: RCTs ≥ 4 weeks comparing the effect of dairy consumption (whole food or supplements with control diets lower in dairy during energy restriction on body weight, fat and lean mass were identified by searching MEDLINE, EMBASE, Pubmed, Cochrane Central and World Health Organization International Clinical Trials Registry Platform (WHO ICTRP until March 2016. Reports were identified and critically appraised in duplicate. Data were pooled using random-effects meta-analysis. Chi2- and I2-statistics indicated heterogeneity. Dose effect was assessed using meta-regression analysis. GRADE guidelines were used to rate the quality (QR of the evidence considering risk of bias, inconsistency, indirectness, imprecision, publication bias and effect estimates. Results: 27 RCTs were reviewed. Participants consumed between 2 and 4 standard servings/day of dairy food or 20–84 g/day of whey protein compared to low dairy control diets, over a median of 16 weeks. A greater reduction in body weight (−1.16 kg [−1.66, −0.66 kg], p < 0.001, I2 = 11%, QR = high, n = 644 and body fat mass (−1.49 kg [−2.06, −0.92 kg], p < 0.001, I2 = 21%, n = 521, QR = high were found in studies largely including women (90% women. These effects were absent in studies that imposed resistance training (QR = low-moderate. Dairy intake resulted in smaller loss of lean mass (all trials pooled: 0.36 kg [0.01, 0.71 kg], p = 0.04, I2 = 64%, n = 651, QR = moderate. No between study dose-response effects were seen. Conclusions: Increased dairy intake as part of energy restricted diets resulted in greater loss in bodyweight and fat mass while attenuating lean mass loss in 18–50-year-old adults. Further research in males is needed to investigate sex effects.

  18. Variables of impact on quality of life of HIV-positive people over 50 years old / Variáveis de impacto na qualidade de vida de pessoas acima de 50 anos HIV+

    Josevânia da Silva; Ana Alayde Werba Saldanha; Regina Lígia Wanderlei de Azevedo

    2010-01-01

    This study aimed to analyze the influence of biodemographic and clinical variables on quality of life of HIV-positive people over 50 years old. For that, 43 HIV-positive people over 50 took part in the study ( M=55; DP =4.6), being 63% male. The Scale of Quality of Life in Old Age (WHOQOL-OLD) and a biodemographic questionnaire were used as instruments. It was verified the impact of biodemographic and clinical variables in the following factors: "Autonomy", "Past, Present and Future Activitie...

  19. Variáveis de impacto na qualidade de vida de pessoas acima de 50 anos HIV+ Variables of impact on quality of life of HIV-positive people over 50 years old

    Josevânia da Silva

    2010-04-01

    Full Text Available Este estudo objetivou analisar a influência de variáveis bio-demográficas e clínicas na qualidade de vida (QV de pessoas acima de 50 anos HIV+. Para tanto, contou-se com a participação de 43 pessoas HIV+ acima de 50 anos ( M=55; DP =4,6, sendo 63% do sexo masculino. Utilizou-se como instrumentos a Escala de Qualidade de Vida para a Velhice (WHOQOL-Old e um questionário bio-demográfico. Verificou-se o impacto de variáveis bio-demográficas e clínicas nos seguintes fatores: "Autonomia", "Atividades passadas, presentes e futuras", "Morte e Morrer" e "Intimidade". A QV apresentou-se como uma dimensão da vida humana indissociável de condições objetivas como trabalho, lazer, moradia, dentre outros. Além disso, esse construto está relacionado a características subjetivas, próprias de cada indivíduo, como o suporte social.This study aimed to analyze the influence of biodemographic and clinical variables on quality of life of HIV-positive people over 50 years old. For that, 43 HIV-positive people over 50 took part in the study ( M=55; DP =4.6, being 63% male. The Scale of Quality of Life in Old Age (WHOQOL-OLD and a biodemographic questionnaire were used as instruments. It was verified the impact of biodemographic and clinical variables in the following factors: "Autonomy", "Past, Present and Future Activities", "Death and Dying" and "Intimacy". The QL presented itself as a dimension of human life which is inseparable from objective conditions such as work, leisure, and housing, among others. Moreover, it is related to subjective characteristics, specific to each individual, such as social support.

  20. HIV and people over 50 years old in Europe

    Lazarus, Jeff; Nielsen, K K

    2010-01-01

    The aim of the study was to report on HIV and older people in the European Region, including new data stratified by subregion and year.......The aim of the study was to report on HIV and older people in the European Region, including new data stratified by subregion and year....

  1. Radiation signatures in childhood thyroid cancers after the Chernobyl accident: Possible roles of radiation in carcinogenesis

    Suzuki, Keiji; Mitsutake, Norisato; Saenko, Vladimir; YAMASHITA, Shunichi

    2015-01-01

    After the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant accident, cancer risk from low-dose radiation exposure has been deeply concerning. The linear no-threshold model is applied for the purpose of radiation protection, but it is a model based on the concept that ionizing radiation induces stochastic oncogenic alterations in the target cells. As the elucidation of the mechanism of radiation-induced carcinogenesis is indispensable to justify the concept, studies aimed at ...

  2. Biology responses to low dose radiation

    Biology responses to low dose radiation is the most important problem of medical radiation and radiation protection. The especial mechanism of low dose or low dose rate induced cell responses, has been found independent with linear no-threshold model. This article emphasize to introduce low dose or low dose rate induced biology responses of adaptive response, by-effect, super-sensitivity and genomic instability. (authors)

  3. Prevalencia de ceguera y limitación visual severa, en personas mayores de 50 años de Ciudad de La Habana Prevalence of blindness and severe visual shortage in over 50 years-old adults in the City of Havana province

    Abel Cabrera Martínez

    2007-12-01

    Full Text Available Se realizó un estudio descriptivo de corte transversal, cuyo universo estuvo constituido por la población mayor de 50 años perteneciente a Ciudad de La Habana, en el período comprendido entre junio de 2004 a junio del 2005. Para la determinación del tamaño de la muestra se asumió como universo los 633 396 habitantes mayores de 50 años de Ciudad Habana, con una estimación de la prevalencia esperada de 4,0 %, un error aceptable del 3 % y un efecto de diseño de 70 %. Se efectuó un muestreo sistemático por conglomerados y se determinó como muestra 2 760 habitantes de Ciudad de La Habana, representada por 46 cluster de 60 individuos cada uno. Se definió como ceguera la agudeza visual con corrección, inferior a 20/400 y la deficiencia visual grave como la agudeza visual con corrección >20/400 y The universe of a cross-sectional descriptive study, which was carried out from June 2004 to June 2005, was made up of people aged over 50 years, who lived in the City of Havana. In order to determine the sample size, 633 396 over 50 years-old inhabitants were taken as the universe of study, with an expected prevalence estimation of 4.0 %, an allowable error of 3 % and a design effect of 70 %. On the basis of these data, systematic cluster sampling was made to determine a sample of 2 760 inhabitants from the City of Havana, represented by 46 clusters of 60 subjects each. Blindness was defined as corrected visual acuity lower than 20/400 and severe visual shortage as corrected visual acuity >20/400 and <20/200 in the best eye and with the best available correction. An inter-observer variation to reduce errors for this reason was also made. The study coverage was 98.4 % of the selected sample. The blindness prevalence by sex was 2.4 %. Prevalence of bilateral blind persons by age increases from 2.6 % at 50 years to 15,2 % at 80 years and over. The most important causes of bilateral blindness were cataract (50 %, glaucoma (26 % and diabetic

  4. Pessoas acima de 50 anos com aids: implicações para o dia-a-dia Personas con más de 50 años que tienen sida: implicaciones para el cotidiano People with more than 50 years old with aids: implications to everyday life

    Soraia Romera Machiesqui

    2010-12-01

    vida.It is a qualitative research that aimed to describe the implications related to everyday life of people with more than 50 years old who acquired immunodeficiency syndrome. It was carried out at a training hospital in the southern Brazil. The data were generated by a dynamic technique using the creativity and sensibility dynamic Speaker Map, with five participants in the group. The data were submitted to a content thematic analysis. From ar tistic productions and reports, emerged the effects from diagnosis discovered; the comprehension that they have a normal life in spite of disease; the faith in God; the prejudice and discrimination; and the silence about the serologic condition. We concluded that the care actions must consider the biological, clinical, social and subjective dimensions in a co-responsibility way in the perspective to their autonomy to health care and to choices of their life.

  5. Commentary: Ethical Issues of Current Health-Protection Policies on Low-Dose Ionizing Radiation

    Socol, Yehoshua; Dobrzyński, Ludwik; Doss, Mohan; Feinendegen, Ludwig E.; Janiak, Marek K.; Miller, Mark L.; Sanders, Charles L.; Scott, Bobby R.; Ulsh, Brant; Vaiserman, Alexander

    2013-01-01

    The linear no-threshold (LNT) model of ionizing-radiation-induced cancer is based on the assumption that every radiation dose increment constitutes increased cancer risk for humans. The risk is hypothesized to increase linearly as the total dose increases. While this model is the basis for radiation safety regulations, its scientific validity has been questioned and debated for many decades. The recent memorandum of the International Commission on Radiological Protection admits that the LNT-m...

  6. New method of techno-economic analysis of radiation impact for nuclear industry

    Chudy, Michal; Müller, Marietta; Slabber, Johan F M

    2016-01-01

    Bearing in mind physical and social aspects, health issues connected with operation of nuclear facilities are under continuous control of national and international regulatory institutions. The main purpose of doing so is to reduce risk of ionizing radiation on human health. Under standard operation of any controlled nuclear facility, direct injuries connected by nonstochastic effects of ionizing radiation, such as Acute Radiation Syndrome (ARS) are theoretically possible only if health and safety measures are violated. On the other hand, the stochastic effect of radiation may cause tumors with increasing probability of received radioactive dose. Nuclear facilities such as nuclear power plants use certain formulas to calculate the cost of potential health damage caused by ionizing radiation. These formulas are derived according to Linear No-Threshold Relationship between the dose and cancer risk. However, this Linear No-Threshold relationship (LNT) is becoming debatable with new radiological research. Therefo...

  7. Commentary on Using LNT for Radiation Protection and Risk Assessment

    Cuttler, Jerry M.

    2010-01-01

    An article by Jerome Puskin attempts to justify the continued use of the linear no-threshold (LNT) assumption in radiation protection and risk assessment. In view of the substantial and increasing amount of data that contradicts this assumption; it is difficult to understand the reason for endorsing this unscientific behavior, which severely constrains nuclear energy projects and the use of CT scans in medicine. Many Japanese studies over the past 25 years have shown that low doses and low do...

  8. Evidence Supporting Radiation Hormesis in Atomic Bomb Survivor Cancer Mortality Data

    Doss, Mohan

    2012-01-01

    A recent update on the atomic bomb survivor cancer mortality data has concluded that excess relative risk (ERR) for solid cancers increases linearly with dose and that zero dose is the best estimate for the threshold, apparently validating the present use of the linear no threshold (LNT) model for estimating the cancer risk from low dose radiation. A major flaw in the standard ERR formalism for estimating cancer risk from radiation (and other carcinogens) is that it ignores the potential for ...

  9. Pros and cons of the revolution in radiation protection

    In 1959, the International Commission of Radiation Protection (ICRP) chose the LNT (Linear No-Threshold) model as an assumption to form the basis for regulating radiation protection. During the 1999 UNSCEAR session, held in April in Vienna, the linear no-threshold (LNT) hypothesis was discussed. Among other LNT-related subjects, the Committee discussed the problem of collective dose and dose commitment. These concepts have been introduced in the early 1960s, as the offspring of the linear no-threshold assumption. At the time they reflected a deep concern about the induction of hereditary effects by nuclear tests fallout. Almost four decades later, collective dose and dose commitment are still widely used, although by now both the concepts and the concern should have faded into oblivion. It seems that the principles and concepts of radiation protection have gone astray and have led to exceedingly prohibitive standards and impractical recommendations. Revision of these principles and concepts is now being proposed by an increasing number of scientists and several organisations

  10. Recent research on the effects of low dose radiation: implications to radiation protection

    Radiation protection specialists unanimously agree that radiation at high dose levels can cause cancer. At low dose levels, the results are not conclusive. Specialists accept the Linear-No-Threshold (LNT) dose-effect relationship as a practical approach in radiation protection. That means that the dose-effect relation is linear without a threshold; any dose however small will have some deleterious effect. Application of LNT without appreciating that it is just a pragmatic concept leads to unreasonable fear about radiation. This adversely impact acceptance of nuclear power as a source of energy

  11. Relationship between microbial diversity and chemical contamination along a 50-year-old sediment core

    Berthe, T.; Petit, F.; Boust, D.; Lesueur, P.; Roose-Amsaleg, C.; Cécillon, S.; Kaci-Benaicha, A.

    2013-12-01

    The purpose of this study was to evaluate the potential use of sediment microbial diversity (community structure) as an indicator of the impact of anthropogenic activities within an estuarine ecosystem. The diversity of microbial communities was investigated along a 5-m-long sediment core collected in an anthropized European estuary (Seine, France), giving an evolution of trace metal, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) concentrations over the last 50 years. An increase of trace metal and PCB concentrations are observed with depth, with an enrichment of these contaminants in the 1970s. The concentration profiles of light, intermediate and heavy PAHs showed distinct peaks, but the highest total PAH concentration was also detected in the sediment from the 1970s. We first investigated the bacterial community resistant to cobalt, zinc and cadmium by analyzing the diversity of the czcA gene encoding an RND efflux pump (Heavy Metal Efflux-RND) in 5-year and 33-year-old sediment samples displaying contrasted concentrations in these trace metals. The diversity of the czcA gene was reduced in the 33-year-old and more contaminated sediments suggesting a selection of resistant bacterial species. A molecular fingerprinting method (DGGE) was used to study the evolution of total microbial (Bacteria and Archaea) community structures for samples selected along the sediment core. A correlation is observed between the bacterial community structures, the sediment age, the trace metal and PAH concentrations. The metabolically active and total microbial communities were further characterized by a microarray approach (Phylochips) in sediment samples selected according to the DGGE results. Bacterial diversity was found dominated by Proteobacteria, Actinobacteria, and Firmicutes in all analyzed samples. Diversity of phylotypes corresponds to changes in PAH and trace metal concentrations in sediment, suggesting that chemical contaminants have selected for well-adapted taxa. In addition, the taxa able to survive and remain active within the contaminated sediments have been identified by characterizing the metabolically active fraction of the microbial communities. This metabolically active community is dominated by the same phyla but different classes are observed.

  12. Cross-national differences in grip strength among 50+ year old Europeans

    Andersen-Ranberg, Karen; Petersen, Inge; Frederiksen, Henrik; Mackenbach, Johan; Christensen, Kaare

    2009-01-01

    Grip strength (GS) has an age- and gender-dependent decline with advancing age. One study comparing GS among extremely old show a North-South gradient with lowest GS in Italy compared to France (intermediary) and Denmark (highest) even after adjusting for confounders. As GS is associated with...... higher rates of functional decline and mortality, and thus may be used as a health indicator, it is of interest to examine whether the results on extremely old can be reproduced in a large-scale European survey. GS was measured in a cross-sectional population-based sample of 27,456 individuals aged 50......, education, health and socioeconomic status. The relative excess was found to be 11% and the absolute difference 5.0 kg for 50- to 54-year-old men, increasing to 28% and 6.9 kg among 80+ year-old men. The corresponding figures for women were 16% and 4.3 kg, and 21% and 3.5 kg, respectively. Southern European...

  13. The demoiselle of X-inactivation: 50 years old and as trendy and mesmerising as ever.

    Céline Morey

    2011-07-01

    Full Text Available In humans, sexual dimorphism is associated with the presence of two X chromosomes in the female, whereas males possess only one X and a small and largely degenerate Y chromosome. How do men cope with having only a single X chromosome given that virtually all other chromosomal monosomies are lethal? Ironically, or even typically many might say, women and more generally female mammals contribute most to the job by shutting down one of their two X chromosomes at random. This phenomenon, called X-inactivation, was originally described some 50 years ago by Mary Lyon and has captivated an increasing number of scientists ever since. The fascination arose in part from the realisation that the inactive X corresponded to a dense heterochromatin mass called the "Barr body" whose number varied with the number of Xs within the nucleus and from the many intellectual questions that this raised: How does the cell count the X chromosomes in the nucleus and inactivate all Xs except one? What kind of molecular mechanisms are able to trigger such a profound, chromosome-wide metamorphosis? When is X-inactivation initiated? How is it transmitted to daughter cells and how is it reset during gametogenesis? This review retraces some of the crucial findings, which have led to our current understanding of a biological process that was initially considered as an exception completely distinct from conventional regulatory systems but is now viewed as a paradigm "par excellence" for epigenetic regulation.

  14. Normal Life Expectancy for Paraganglioma Patients: A 50-Year-Old Cohort Revisited

    de Flines, Jeanette; Jansen, Jeroen; Elders, Reinier; Siemers, Maaike; Vriends, Annette; Hes, Frederik; Bayley, Jean-Pierre; van der Mey, Andel; Corssmit, Eleonora

    2011-01-01

    The objective of this study was to assess the long-term survival of patients with a paraganglioma of the head and neck compared with the survival of the general Dutch population. This historic cohort study was conducted using nationwide historical data of paraganglioma patients. We retrieved a cohort of 86 patients diagnosed with a paraganglioma of the head and neck between 1945 and 1960 in the Netherlands. Dates of death were retrieved from the national bureau of genealogy. Survival after di...

  15. Radiation signatures in childhood thyroid cancers after the Chernobyl accident: possible roles of radiation in carcinogenesis.

    Suzuki, Keiji; Mitsutake, Norisato; Saenko, Vladimir; Yamashita, Shunichi

    2015-02-01

    After the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant accident, cancer risk from low-dose radiation exposure has been deeply concerning. The linear no-threshold model is applied for the purpose of radiation protection, but it is a model based on the concept that ionizing radiation induces stochastic oncogenic alterations in the target cells. As the elucidation of the mechanism of radiation-induced carcinogenesis is indispensable to justify the concept, studies aimed at the determination of molecular changes associated with thyroid cancers among children who suffered effects from the Chernobyl nuclear accident will be overviewed. We intend to discuss whether any radiation signatures are associated with radiation-induced childhood thyroid cancers. PMID:25483826

  16. Radiation biology of low doses

    Present risk assessments and standards in radiation protection are based on the so-called linear no-threshold (LNT) dose - effect hypothesis, i.e., on a linear, proportional relationship between radiation doses and their effects on biological systems. This concept presupposes that any dose, irrespective of its level and time of occurrence, carries the same risk coefficient and, moreover, that no individual biological effects are taken into account. This contribution presents studies of low energy transfer (LET) radiation which deal with the risk of cancer to individual cells. According to the LNT hypothesis, the relationship for the occurrence of these potential effects should be constant over the dose range: successful repair, cell death, mutation with potential carcinogenesis. The results of the studies presented here indicate more differentiated effects as a function of dose application as far as damage to cellular DNA by ionizing radiation is concerned. At the same overall dose level, multiple exposures to low doses sometimes give rise to much smaller effects than those arising from one single exposure to the total dose. These adaptive effects of cells are known from other studies. The results of the study allow the conclusion to be drawn that non-linear relationships must be assumed to exist for the LET radiation considered. Correspondingly, the linear no-threshold hypothesis model should at least be reconsidered with respect to the low dose range in the light of recent biological findings. The inclusion of other topical research findings also could give rise to a new, revised, risk-oriented approach in radiological protection. (orig.)

  17. Some problems in the acceptability of implementing radiation protection programs

    The three fundamentals that radiation protection programs are based upon are; 1) establishing a quantitative correlation between radiation exposure and biological effects in people; 2) determining a level of acceptable risk of exposure; and 3) establishing systems to measure the radiation dose to insure compliance with the regulations or criteria. The paper discusses the interrelationship of these fundamentals, difficulties in obtaining a consensus of acceptable risk and gives some examples of problems in identifying the most critical population-at-risk and in measuring dose. Despite such problems, it is recommended that we proceed with the existing conservative structure of radiation protection programs based upon a linear no threshold model for low radiation doses to insure public acceptability of various potential radiation risks. Voluntary compliance as well as regulatory requirements should continue to be pursued to maintain minimal exposure to ionizing radiation. (author)

  18. Whole body exposure to low-dose γ-radiation enhances the antioxidant defense system

    It is believed that the extent of cellular damage by low- radiation dose is proportional to the effects observed at high radiation dose as per the Linear-No-Threshold (LNT) hypothesis. However, this notion may not be true at low-dose radiation exposure in the living system. Recent evidence suggest that the living organisms do not respond to ionizing radiations in a linear manner in the low dose range 0.01-0.5Gy and rather restore the homeostasis both in vivo and in vitro by normal physiological mechanisms such as cellular and DNA repair processes, immune reactions, antioxidant defense, adaptive responses, activation of immune functions, stimulation of growth etc. In this study, we have attempted to find the critical radiation dose range and the post irradiation period during which the antioxidant defense systems in the lungs, liver and kidneys remain stimulated in these organs after whole body exposure of the animals to low-dose radiation

  19. Effect of adapted karate training on quality of life and body balance in 50-year-old men

    Marie-Ludivine Chateau-Degat; Gérard Papouin; Philippe Saint-Val; et al.

    2010-01-01

    Marie-Ludivine Chateau-Degat1, Gérard Papouin2, Philippe Saint-Val3, Antonio Lopez21Axe sante des populations et environmentale, CHUQ, Laval University, Quebec, Canada; 2Service de Cardiologie, Centre Hospitalier Territorial du Taone, 3Fédération Tahitienne de Karaté, Papeete, French PolynesiaBackground: Aging is associated with a decrease in physical skills, sometimes accompanied by a change in quality of life (QOL). Long-term martial arts practice...

  20. Neurodegenerative changes in the brainstem and olfactory bulb in people older than 50 years old: a descriptive study

    Francine Hehn de Oliveira

    2015-07-01

    Full Text Available With the increase in life expectancy in Brazil, concerns have grown about the most prevalent diseases in elderly people. Among these diseases are neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases. Protein deposits related to the development of these diseases can pre-date the symptomatic phases by years. The tau protein is particularly interesting: it might be found in the brainstem and olfactory bulb long before it reaches the limbic cortex, at which point symptoms occur. Of the 14 brains collected in this study, the tau protein was found in the brainstems of 10 (71.42% and in olfactory bulbs of 3 out 11. Of the 7 individuals who had a final diagnosis of Alzheimer’s disease (AD, 6 presented tau deposits in some region of the brainstem. Our data support the idea of the presence of tau protein in the brainstem and olfactory bulb in the earliest stages of AD.

  1. Radiation risk to low fluences of alpha particles may be greater than we thought.

    Zhou, H; Suzuki, M; Randers-Pehrson, G; Vannais, D; Chen, G; Trosko, J E; Waldren, C A; Hei, T K

    2001-12-01

    Based principally on the cancer incidence found in survivors of the atomic bombs dropped in Hiroshima and Nagasaki, the International Commission on Radiation Protection (ICRP) and the United States National Council on Radiation Protection and Measurements (NCRP) have recommended that estimates of cancer risk for low dose exposure be extrapolated from higher doses by using a linear, no-threshold model. This recommendation is based on the dogma that the DNA of the nucleus is the main target for radiation-induced genotoxicity and, as fewer cells are directly damaged, the deleterious effects of radiation proportionally decline. In this paper, we used a precision microbeam to target an exact fraction (either 100% or making risk estimates for low dose, high linear-energy-transfer (LET) radiation exposure. PMID:11734643

  2. Review of the controversy on risks from low levels of radiation

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

  3. Pooled Bayesian meta-analysis of two Polish studies on radiation-induced cancers

    The robust Bayesian regression method was applied to perform meta-analysis of two independent studies on influence of low ionising radiation doses on the occurrence of fatal cancers. The re-analysed data come from occupational exposure analysis of nuclear workers in Swierk (Poland) and from ecological study of cancer risk from natural background radiation in Poland. Such two different types of data were analysed, and three popular models were tested: constant, linear and quadratic dose-response dependencies. The Bayesian model selection algorithm was used for all models. The Bayesian statistics clearly indicates that the popular linear no-threshold (LNT) assumption is not valid for presented cancer risks in the range of low doses of ionising radiation. The subject of LNT hypothesis use in radiation risk prediction and assessment is also discussed. (authors)

  4. Radiation exposure in fetal and childhood period

    After East Japan earthquake of March 2011 and Fukushima Daiichi nuclear power plant accident, much more attention has been paid against radiation exposure. Children are much more radiosensitive than adults for radiation exposure. Biological radiation effect has been studied and estimated primarily by using Hiroshima and Nagasaki data of the atomic bomb victims. And the effects of the long term low dose radiation and high dose exposure in the short term are not as well. Effects of radiation exposure in fetal period appear as miscarriage, malformation, and mental retardation. The estimated threshold is 100 mSv. On the other hand, there could be no threshold for the carcinogenesis as late effects of ionizing radiation. The risk of leukemia and solid cancers could be increased along with radiation exposure. Especially thyroid cancer in children increased after the Chernobyl accident. The linear no-threshold (LNT) model is based on the assumption that the risk is directly proportional to the dose at all dose levels, and forms the basis of the radiation protection of the International Commission of Radiological Protection (ICRP). This leads to ALARA concept, which is an acronym for ''As Low As Reasonably Achievable''. Herewith I introduce the concept of radiation protection with review of previous reports, and discuss how to minimize diagnostic radiation exposure. (author)

  5. Biological effects of low doses of ionizing radiation: Conflict between assumptions and observations

    Recent epidemiological data on cancer incidence among the A-bomb survivors and more importantly experimental studies in cell and molecular radiobiology do not lend unequivocal support to the ''linear, no threshold'' (LNT) hypothesis; in fact, the discernible evidence that low and high doses of ionizing radiations induce qualitatively different/opposite effects cannot be summarily rejected. A time has come to examine the mechanistic aspects of ''radiation hormesis'' and ''radioadaptive response'' seriously rather than proclaiming one's profound disbelief about these phenomena. To put the discussion in a serious scientific mode, we briefly catalogue here reports in the literature on gene expression differentially influenced by low and high doses. These are not explicable in terms of the current radiation paradigm. (author)

  6. Secondary osteoporosis due to radiation

    Bone mineral density (BMD) of the 3rd lumber vertebra (L3) and the 5th lumber vertebra (L5) were measured by quantitative computed tomography (QCT). BMD of L3 and L5 in 139 normal control cases decreased linearly with age (L3: Y= 317.32 - 3.283X, L5: Y= 314.35 - 2.9056X). Ratio of the BMD of L5 to L3 (L5/L3 ratio, %) was constant in the value of 106.03±12.84% before 50 years old and increased linearly after 50 years old (Y= 21.624 + 1.7187X). In 30 radiated cases, BMD of the radiated L5 ws decreased after 20 Gy of radiation and reached 47.44±18.74% of the preradiated value after 50 Gy of radiation. L5/L3 ratio was also decreased after 20 Gy of radiation and reached 48.34±19.33% of pre-radiated value after 50 Gy radiation. BMD of L5 and L5/L3 ratio after 50 Gy of radiation were decreased linearly with age (L5: Y= 107.44 - 0.9686X, L5/L3 ratio: Y= 106.98 - 0.9472X). Quality of life (performance status: PS, lumbago score) after radiation correlated significantly with age, body weight, BMD of L3 before radiation, BMD of L5 after radiation. PS and lumbago score were increased significantly in cases of more than 75 years old, less than 50 kg, less than 100 mg/cm3 of BMD of L3 before radiation and less than 40 mg/cm3 of BMD of L5 after radiation. Quality of life after radiation was improved by treatment of alfacalcidol (PS: 3.0±0.61 to 1.2±0.47, lumbago score: 15.4±4.08 to 4.2±1.17). In conclusion, it should be said that pelvic radiation for gynecologic malignancy may disturb the bone metabolism and quality of life in the early phase after radiation, especially in the aged patients and that quality of life could be improved by treatment of alfacalcidol. (author)

  7. Future of Radiation Protection Regulations.

    Doss, Mohan

    2016-03-01

    THERE IS considerable disagreement in the scientific community regarding the carcinogenicity of low-dose radiation (LDR), with publications supporting opposing points of view. However, major flaws have been identified in many of the publications claiming increased cancer risk from LDR. The data generally recognized as the most important for assessing radiation effects in humans, the atomic bomb survivor data, are often cited to raise LDR cancer concerns. However, these data no longer support the linear no-threshold (LNT) model after the 2012 update but are consistent with radiation hormesis. Thus, a resolution of the controversy regarding the carcinogenicity of LDR appears to be imminent, with the rejection of the LNT model and acceptance of radiation hormesis. Hence, for setting radiation protection regulations, an alternative approach to the present one based on the LNT model is needed. One approach would be to determine the threshold dose for the carcinogenic effect of radiation from existing data and establish regulations to ensure radiation doses are kept well below the threshold dose. This can be done by setting dose guidelines specifying safe levels of radiation doses, with the requirement that these safe levels, referred to as guidance levels, not be exceeded significantly. Using this approach, a dose guidance level of 10 cGy for acute radiation exposures and 10 cGy y for exposures over extended periods of time are recommended. The concept of keeping doses as low as reasonably achievable, known as ALARA, would no longer be required for low-level radiation exposures not expected to exceed the dose guidance levels significantly. These regulations would facilitate studies using LDR for prevention and treatment of diseases. Results from such studies would be helpful in refining dose guidance levels. The dose guidance levels would be the same for the public and radiation workers to ensure everyone's safety. PMID:26808881

  8. Knowledge on radiation dose-rate for risk communication on nuclear power plants

    The sense of anxiety on radiation after Fukushima Dai-ichi accident has not disappeared because of the nightmare scenario on radiation cultivated through the Cold War era starting at the atomic bomb dropping at Hiroshima and Nagasaki. In the present paper, from the viewpoint of establishing the social acceptance of nuclear power plants as well as new reasonable regulation, biological defense in depth (production of anti-oxidants, DNA repair, cell death/apoptosis, and immune defense mechanisms) found in a few decades are presented in comparison with the linear no-threshold (LNT) model for the induction of cancer in the range up to 100 mSv (as single or annual doses) applied for the present regulation. (author)

  9. Vanguards of paradigm shift in radiation biology. Radiation-induced adaptive and bystander responses

    The risks of exposure to low dose ionizing radiation (below 100 mSv) are estimated by extrapolating from data obtained after exposure to high dose radiation, using a linear no-threshold model (LNT model). However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose/low dose-rate radiation than they do to high dose/high dose-rate radiation. In other words, there are accumulated findings which cannot be explained by the classical ''target theory'' of radiation biology. The radioadaptive response, radiation-induced bystander effects, low-dose radio-hypersensitivity, and genomic instability are specifically observed in response to low dose/low dose-rate radiation, and the mechanisms underlying these responses often involve biochemical/molecular signals that respond to targeted and non-targeted events. Recently, correlations between the radioadaptive and bystander responses have been increasingly reported. The present review focuses on the latter two phenomena by summarizing observations supporting their existence, and discussing the linkage between them from the aspect of production of reactive oxygen and nitrogen species. (author)

  10. Plenary panel 1: The scientific bases of radiation protection. Non-targeted effects of ionising radiation - Implications for radiation protection

    Salomaa, S. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-07-01

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects, genomic instability and adaptive response. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. New aspects include the role of cellular communication and tissue-level responses. A better understanding of non-targeted effects may have important consequences for health risk assessment and, consequently, on radiation protection. Non-targeted effects may contribute to the estimation of cancer risk from occupational, medical and environmental exposures. In particular, they may have implications for the applicability of the Linear-No-Threshold (L.N.T.) model in extrapolating radiation risk data into the low-dose region. This also means that the adequacy of the concept of dose to estimate risk is challenged by these findings. Moreover, these effects may provide new mechanistic explanations for the development of non-cancer diseases. Further research is required to determine if these effects, typically measured in cell cultures, are applicable in tissue level, whole animals, and ultimately in humans. (authors)

  11. Plenary panel 1: The scientific bases of radiation protection. Non-targeted effects of ionising radiation - Implications for radiation protection

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects, genomic instability and adaptive response. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. New aspects include the role of cellular communication and tissue-level responses. A better understanding of non-targeted effects may have important consequences for health risk assessment and, consequently, on radiation protection. Non-targeted effects may contribute to the estimation of cancer risk from occupational, medical and environmental exposures. In particular, they may have implications for the applicability of the Linear-No-Threshold (L.N.T.) model in extrapolating radiation risk data into the low-dose region. This also means that the adequacy of the concept of dose to estimate risk is challenged by these findings. Moreover, these effects may provide new mechanistic explanations for the development of non-cancer diseases. Further research is required to determine if these effects, typically measured in cell cultures, are applicable in tissue level, whole animals, and ultimately in humans. (authors)

  12. Non-targeted effects of ionising radiation

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects and genomic instability. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm would cover both the classical (targeted) and the non-targeted effects. New aspects include the role of cellular communication and tissue-level responses. A better understanding of non-targeted effects may have important consequences for health risk assessment and, consequently, on radiation protection. Non-targeted effects may contribute to the estimation of cancer risk from occupational, medical and environmental exposures. In particular, they may have implications for the applicability of the Linear-No-Threshold (LNT) model in extrapolating radiation risk data into the low-dose region. This also means that the adequacy of the concept of dose to estimate risk is challenged by these findings. Moreover, these effects may provide new mechanistic explanations for the development of non-cancer diseases. Further research is required to determine if these effects, typically measured in cell cultures, are applicable in tissue level, whole animals, and ultimately in humans. (orig.)

  13. Radiation protection. Basic concepts of ICRP

    The title subject is easily explained. Main international organizations for radiation protection are United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), International Commission on Radiological Protection (ICRP) and International Atomic Energy Agency (IAEA). The UNSCEAR objectively summarizes and publishes scientific findings; ICRP, an NGO, takes part in recommending the radiological protection from the expertized aspect; and IAEA, a UN autonomy, aims at peaceful usage of atomic power. These organizations support the legal regulation and standard of nations. The purpose of the ICRP recommendation (Pub. 103, 2007) is to contribute to the appropriate protection of radiation hazardous effects, which are assumed to be linearly proportional (the model of linear no-threshold, LNT) that radiation risk exists even at the lowest dose. When a change in the single cell results in hazardous alteration, the causative effects are called stochastic effects, which include the mutation leading to cancer formation and genetic effect in offspring (not observed in man). ICRP says the validity of LNT for the stochastic effects essentially from the protective aspect, although epidemiological data support it at >100 mSv exposure. The deterministic effects are caused by loss of cell itself or of its function, where the threshold is defined to be the dose causing >1% of disorder or death. Radiation protective system against exposure is on the situation (programmed, emergent and natural), category (occupational, public and medical) and 3 principles of justification, optimization and application of dose limit. (T.T.)

  14. Low dose ionizing radiation induced acoustic neuroma: A putative link?

    Sachin A Borkar

    2012-01-01

    Full Text Available Although exposure to high dose ionizing radiation (following therapeutic radiotherapy has been incriminated in the pathogenesis of many brain tumors, exposure to chronic low dose ionizing radiation has not yet been shown to be associated with tumorigenesis. The authors report a case of a 50-year-old atomic reactor scientist who received a cumulative dose of 78.9 mSv over a 10-year period and was detected to have an acoustic neuroma another 15 years later. Although there is no proof that exposure to ionizing radiation was the cause for the development of the acoustic neuroma, this case highlights the need for extended follow-up periods following exposure to low dose ionizing radiation.

  15. Non-targeted effects of ionising radiation - Implications for radiation protection

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects, genomic instability and adaptive response. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. New aspects include the role of cellular communication and tissue-level responses. A better understanding of non-targeted effects may have important consequences for health risk assessment and, consequently, on radiation protection. Non-targeted effects may contribute to the estimation of cancer risk from occupational, medical and environmental exposures. In particular, they may have implications for the applicability of the Linear-No-Threshold (LNT) model in extrapolating radiation risk data into the low-dose region. This also means that the adequacy of the concept of dose to estimate risk is challenged by these findings. Moreover, these effects may provide new mechanistic explanations for the development of non-cancer diseases. Further research is required to determine if these effects, typically measured in cell cultures, are applicable in tissue level, whole animals, and ultimately in humans. (author)

  16. Non-targeted effects of ionising radiation - Implications for radiation protection

    Sisko Salomaa [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-07-01

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects, genomic instability and adaptive response. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. New aspects include the role of cellular communication and tissue-level responses. A better understanding of non-targeted effects may have important consequences for health risk assessment and, consequently, on radiation protection. Non-targeted effects may contribute to the estimation of cancer risk from occupational, medical and environmental exposures. In particular, they may have implications for the applicability of the Linear-No-Threshold (LNT) model in extrapolating radiation risk data into the low-dose region. This also means that the adequacy of the concept of dose to estimate risk is challenged by these findings. Moreover, these effects may provide new mechanistic explanations for the development of non-cancer diseases. Further research is required to determine if these effects, typically measured in cell cultures, are applicable in tissue level, whole animals, and ultimately in humans. (author)

  17. The dose makes the poison. Even for radiation

    The dose makes the poison, a quote by Paracelsus a doctor who lived half a millennium ago, is still valid today. Nevertheless this general accepted fact is being excluded in relation to ionizing radiation, which is wrongly considered as radioactive radiation. Here applies the LNT-Hypothesis (Linear No Threshold), agreed on by the ICRP, the Commission on Radiological Protection, a dose-to-effect relationship, which is based on the EU directives and the German Radiation Protection Ordinance. The LNT-hypothesis states, that even every smallest dose of radiation already provides a potentiality of danger and was introduced as precaution assuming that self-healing mechanisms even through weak radiation of damaged cells can be excluded and every damage caused by radiation inevitably leads to cell mutation and with it to cancer development. Without any further knowledge assumptions were made, that the same mechanism for cancer development applies for high and small doses. This assumption turned out to be wrong, as it is increasingly reported on findings which show, that smaller doses of ionized radiation demonstrably does not cause any damage, but on the contrary can even be healthy.

  18. Ionizing radiation in 21st century

    The paper begins with the author's personal experience in Poland on the occasion of Chernobyl nuclear accident followed by main lessons that the author could deduce from the accident. After the discovery of ionizing radiation at the end of 19th century, social perception has altered between acceptance and rejection stemming from recognition of the basic aspects: usefulness for medical applications and for technical and scientific aims, beneficial effects of their low levels, and harmful effects of high levels. The author explains how linear no-threshold (LNT) assumption according to which even the lowest, near zero doses of radiation may cause cancer genetic harm has become established. Comparing the natural radioactivity of the earth's crust with the activity of much shorter-lived radioactive wastes from the nuclear power cycle, it is concluded that none of the man-made component of the radioactive wastes has higher-toxicity than the natural Th 232. The paper concludes by stating that one century has not been long enough to adapt mentally to ionizing radiation and radioactivity and perhaps 21st century will suffice for this adaptation. (S. Ohno)

  19. Non-targeted effects of ionising radiation - A challenge to the current radiobiological paradigm

    A basic paradigm in radiobiology is that, after exposure to ionising radiation, the deposition of energy in the cell nucleus and the resulting damage to DNA, the primary target, are responsible for the harmful biological effects of radiation. The radiation-induced changes are thought to be fixed already in the first cell division following the radiation exposure and health effects are considered to result as a consequence of clonal proliferation of cells carrying mutations in specific genes. Since the initial damage induced in DNA has been shown to be directly proportional to dose, risk is also considered to be directly proportional to dose. Risk from multiple exposures is considered to be additive, and risk from high and low LET radiation exposure is assumed to be qualitatively the same. These assumptions are incorporated into the Linear-No-Threshold (LNT) Hypothesis that is used in all radiation protection practices. A range of evidence has now emerged that challenges the universality of the target theory of radiation induced effects. These effects have also been termed 'non-(DNA)-targeted' and include radiation-induced bystander effects, genomic instability, adaptive response, low-dose hyper-radiosensitivity, abscopal (out-of-field) effects of radiotherapy, clastogenic factors, delayed reproductive death and induction of genes by radiation. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. New aspects include the role of cellular communication and tissue-level responses. A better understanding of non-targeted effects may have important consequences on the health risk assessment and, consequently, on radiation protection. The non-targeted effects may contribute to the estimation of cancer

  20. Radiation

    The chapter one presents the composition of matter and atomic theory; matter structure; transitions; origin of radiation; radioactivity; nuclear radiation; interactions in decay processes; radiation produced by the interaction of radiation with matter

  1. Evidence for beneficial low level radiation effects and radiation hormesis

    Low doses in the mGy range cause a dual effect on cellular DNA. One effect concerns a relatively low probability of DNA damage per energy deposition event and it increases proportional with dose, with possible bystander effects operating. This damage at background radiation exposure is orders of magnitudes lower than that from endogenous sources, such as ROS. The other effect at comparable doses brings an easily obeservable adaptive protection against DNA damage from any, mainly endogenous sources, depending on cell type, species, and metabolism. Protective responses express adaptive responses to metabolic perturbations and also mimic oxygen stress responses. Adaptive protection operates in terms of DNA damage prevention and repair, and of immune stimulation. It develops with a delay of hours, may last for days to months, and increasingly disappears at doses beyond about 100 to 200 mGy. Radiation-induced apoptosis and terminal cell differentiation occurs also at higher doses and adds to protection by reducing genomic instability and the number of mutated cells in tissues. At low doses, damage reduction by adaptive protection against damage from endogenous sources predictably outweighs radiogenic damage induction. The analysis of the consequences of the particular low-dose scenario shows that the linear-no-threshold (LNT) hypothesis for cancer risk is scientifically unfounded and appears to be invalid in favor of a threshold or hormesis. This is consistent with data both from animal studies and human epidemiological observations on low-dose induced cancer. The LNT hypothesis should be abandoned and be replaced by a hypothesis that is scientifically justified. The appropriate model should include terms for both linear and non-linear response probabilities. Maintaining the LNT-hypothesis as basis for radiation protection causes unressonable fear and expenses. (author)

  2. Fifth Warren K. Sinclair Keynote Address: Issues in quantifying the effects of low-level radiation.

    Goodhead, Dudley T

    2009-11-01

    Health risks from exposure to high doses of ionizing radiation are well characterized from epidemiological studies. Uncertainty and controversy remain for extension of these risks to the low doses and low dose rates of particular relevance in the workplace, in medical diagnostics and screening, and from background radiations. In order to make such extrapolations, a number of concepts have been developed for radiation protection, partly on the basis of assumed processes in the mechanisms of radiation carcinogenesis. Included amongst these are the assumptions of a linear no-threshold dose response and simple scaling factors for dose rate and radiation quality. With a progressive reduction in recommended dose limits over the past half century, these approaches have had considerable success in protecting humans. But do they go far enough or, conversely, are they overprotective? Four selected underlying aspects are considered. It is concluded that (1) even the lowest dose of radiation has the capability to cause complex DNA damage that can lead to a variety of permanent cellular changes; (2) the unique clustered characteristics of radiation damage, even at very low doses, enable it to stand out above the much larger quantity of endogenous DNA damage; (3) although a chromosome aberration may represent the rate-limiting initiating event for carcinogenesis, as is often assumed, direct evidence is still lacking; and (4) the extensive influence that dicentric aberrations have had on guiding extrapolations for radiation protection may be substantially misleading. Finally, some comments are offered on aspects that lie outside the current paradigm. PMID:19820449

  3. The influence of the exercises by the system of j . Pilates on the indexes of the external respiration of 30-50-year-old women

    АНДРЕЕВА М.В.; M. V. Andreeva

    2010-01-01

    Дается оценка показателям внешнего дыхания (ЖЕЛ, МОД, ДО, ЧД, МВЛ), отражающим эффективность занятий по системе Дж. Пилатеса. In the article there is the evaluation of the indexes of the external respiration (lung vital capacity, maximal breath volume, breath volume, breathing rate, minute pulmonary ventilation), which show the efficiency of exercises by the system of J. Pilates.

  4. Childhood and Adolescent Body Fat and Its Relationship with Health Outcome in 50 Year Old Males and Females: The Wroclaw Growth Study

    Kozieł, Sławomir; Lipowicz, Anna; Hulanicka, Barbara

    2011-01-01

    The aim of the study was to estimate the association between relative weight in childhood and adolescence and its relationship with adult health outcome. Longitudinal data of the body mass index (BMI) from the Wroc³aw Growth Study (WGS) covering ages 8 to 18 and then a follow-up at 50 were used. At the age of 50, 124 males and 139 females in the longitudinal study underwent medical examination. Systolic and diastolic blood pressure (SBP, DBP), total cholesterol (TCH), high density...

  5. Low radiation dose effects - is it a myth or reality?

    The effects of low-level radiation are very difficult to observe and highly controversial. The radiation doses that result from chronic exposures but does not manifest in deterministic effects could be categorised as low radiation doses. These doses result in only potential stochastic effects which are probabilistic in nature. On the other hand, high radiation doses result in both deterministic effects and stochastic effects. Stochastic effects from higher doses are extrapolated linearly to the low doses on the basis of a hypothesis that the dose response curve is linear at all doses. This is what is termed as 'Linear No Threshold (LNT)' hypothesis. Based on this hypothesis, all regulatory agencies stipulate regulatory limits for radiation workers and for members of public. Particularly, the optimisation principle of radiation protection 'as low as reasonably achievable (ALARA)' is insisted on by regulatory bodies resulting in the often asked question as to whether it is really evidence based hypothesis or fear based regulatory concern. Many studies of high background areas in India, Iran, Brazil, etc. have not resulted in proof of excess cancer risk at radiation doses encountered in these areas of high background. Studies on large population of radiation workers who have received higher radiation doses than stipulated in the earlier periods of radiation safety limits have also not shown any increase in cancer incidence ascribable to radiation dose. On the contrary studies have shown, documented by many reputed scientific journals, American Nuclear Society, World Nuclear Agency and BEIR Committee that at low radiation doses the dose response curve is not only nonlinear but also shows a threshold for any harmful effect. (author)

  6. The communication of the radiation risk from CT in relation to its clinical benefit in the era of personalized medicine. Pt. 1. The radiation risk from CT

    The theory of radiation carcinogenesis has been debated for decades. Most estimates of the radiation risks from CT have been based on extrapolations from the lifespan follow-up study of atomic bomb survivors and on follow-up studies after therapeutic radiation, using the linear no-threshold theory. Based on this, many population-based projections of induction of future cancers by CT have been published that should not be used to estimate the risk to an individual because of their large margin of error. This has changed recently with the publication of three large international cohort follow-up studies, which link observed cancers to CT scans received in childhood. A fourth ongoing multi-country study in Europe is expected to have enough statistical power to address the limitations of the prior studies. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) report released in 2013 specifically addresses variability in response of the pediatric population exposed to ionizing radiation. Most authorities now conclude that there is enough evidence to link future cancers to the radiation exposure from a single CT scan in childhood but that cancer risk estimates for individuals must be based on the specifics of exposure, age at exposure and absorbed dose to certain tissues. Generalizations are not appropriate, and the communication of the CT risk to individuals should be conducted within the framework of personalized medicine. (orig.)

  7. The communication of the radiation risk from CT in relation to its clinical benefit in the era of personalized medicine. Pt. 1. The radiation risk from CT

    Westra, Sjirk J. [Massachusetts General Hospital, Division of Pediatric Radiology, Boston, MA (United States)

    2014-10-15

    The theory of radiation carcinogenesis has been debated for decades. Most estimates of the radiation risks from CT have been based on extrapolations from the lifespan follow-up study of atomic bomb survivors and on follow-up studies after therapeutic radiation, using the linear no-threshold theory. Based on this, many population-based projections of induction of future cancers by CT have been published that should not be used to estimate the risk to an individual because of their large margin of error. This has changed recently with the publication of three large international cohort follow-up studies, which link observed cancers to CT scans received in childhood. A fourth ongoing multi-country study in Europe is expected to have enough statistical power to address the limitations of the prior studies. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) report released in 2013 specifically addresses variability in response of the pediatric population exposed to ionizing radiation. Most authorities now conclude that there is enough evidence to link future cancers to the radiation exposure from a single CT scan in childhood but that cancer risk estimates for individuals must be based on the specifics of exposure, age at exposure and absorbed dose to certain tissues. Generalizations are not appropriate, and the communication of the CT risk to individuals should be conducted within the framework of personalized medicine. (orig.)

  8. Commentary: ethical issues of current health-protection policies on low-dose ionizing radiation.

    Socol, Yehoshua; Dobrzyński, Ludwik; Doss, Mohan; Feinendegen, Ludwig E; Janiak, Marek K; Miller, Mark L; Sanders, Charles L; Scott, Bobby R; Ulsh, Brant; Vaiserman, Alexander

    2014-05-01

    The linear no-threshold (LNT) model of ionizing-radiation-induced cancer is based on the assumption that every radiation dose increment constitutes increased cancer risk for humans. The risk is hypothesized to increase linearly as the total dose increases. While this model is the basis for radiation safety regulations, its scientific validity has been questioned and debated for many decades. The recent memorandum of the International Commission on Radiological Protection admits that the LNT-model predictions at low doses are "speculative, unproven, undetectable and 'phantom'." Moreover, numerous experimental, ecological, and epidemiological studies show that low doses of sparsely-ionizing or sparsely-ionizing plus highly-ionizing radiation may be beneficial to human health (hormesis/adaptive response). The present LNT-model-based regulations impose excessive costs on the society. For example, the median-cost medical program is 5000 times more cost-efficient in saving lives than controlling radiation emissions. There are also lives lost: e.g., following Fukushima accident, more than 1000 disaster-related yet non-radiogenic premature deaths were officially registered among the population evacuated due to radiation concerns. Additional negative impacts of LNT-model-inspired radiophobia include: refusal of some patients to undergo potentially life-saving medical imaging; discouragement of the study of low-dose radiation therapies; motivation for radiological terrorism and promotion of nuclear proliferation. PMID:24910586

  9. Low doses of ionizing radiation: Biological effects and regulatory control. Invited papers and discussions. Proceedings of an international conference

    The levels and biological effects resulting from exposure to ionizing radiation are continuously reviewed by the United Nations Committee on the Effects of Atomic Radiation (UNSCEAR). Since its creation in 1928, the International Commission on Radiological Protection (ICRP) has issued recommendations on protection against ionizing radiation. The UNSCEAR estimates and the ICRP recommendations have served as the basis for national and international safety standards on radiation safety, including those developed by the International Atomic Energy Agency (IAEA) and the World Health Organization (WHO). Concerning health effects of low doses of ionizing radiation, the international standards are based on the plausible assumption that, above the unavoidable background radiation dose, the probability of effects increases linearly with dose, i.e. on a 'linear, no threshold' (LNT) assumption. However, in recent years the biological estimates of health effects of low doses of ionizing radiation and the regulatory approach to the control of low level radiation exposure have been much debated. To foster information exchange on the relevant issues, an International Conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, jointly sponsored by the IAEA and WHO in co-operation with UNSCEAR, was held from 17-21 November 1997 at Seville, Spain. These Proceedings contain the invited special reports, keynote papers, summaries of discussions, session summaries and addresses presented at the opening and closing of the Conference

  10. Do we need a new cost/benefit assessment for low radiation doses?

    Current cost/benefit estimates related to radiation protection, e.g. regarding the consequences of population exposures after accidents, decommissioning and waste management programs, etc., are based on the linear-no-threshold hypothesis and the related collective dose concept, as recommended in ICRP 60, the Basic Safety Standards (BSS), and EU directives. However, the extrapolation from very high to very low doses is increasingly questioned by radiation scientists for fundamental radiobiological reasons, as well as by epidemiological studies with exposed populations. Moreover, if also applied to natural radiation (e.g. in mining or high natural radiation areas, or radon in buildings), the resulting high costs justify, for ethical as well as socio-economical reasons, a careful analysis of the actual benefits of such measures, to be compared with demonstrable health detriments and the cost/benefit ratio in other public health and risk reduction programs in modern industrial societies. Some aspects of these problems will be discussed briefly, and summarized in questions addressed to the advisory bodies on whose recommendations current regulations are based. As a first step, abolishment of the use of the collective dose concept below about 100 mSv total of ''artificial'' radiation per person of the public, and below 50 mSv p.a. for radiation workers, appears advisable. (author)

  11. Molecular alterations in childhood thyroid cancer after Chernobyl accident and low-dose radiation risk

    The linear no-threshold (LNT) model of radiation carcinogenesis has been used for evaluating the risk from radiation exposure. While the epidemiological studies have supported the LNT model at doses above 100 mGy, more uncertainties are still existed in the LNT model at low doses below 100 mGy. Thus, it is urged to clarify the molecular mechanisms underlying radiation carcinogenesis. After the Chernobyl accident in 1986, significant amount of childhood thyroid cancer has emerged in the children living in the contaminated area. As the incidence of sporadic childhood thyroid cancer is very low, it is quite evident that those cancer cases have been induced by radiation exposure caused mainly by the intake of contaminated foods, such as milk. Because genetic alterations in childhood thyroid cancers have extensively been studied, it should provide a unique chance to understand the molecular mechanisms of radiation carcinogenesis. In a current review, molecular signatures obtained from the molecular studies of childhood thyroid cancer after Chernobyl accident have been overviewed, and new roles of radiation exposure in thyroid carcinogenesis will be discussed. (author)

  12. Health risks associated with low dose diagnostic or therapeutic radiation exposures

    The health risks to humans associated with exposure to low doses of ionizing radiation have been extrapolated from effects observed at high doses, dose rates, and mixed radiation qualities using a linear no threshold model. Based on this approach, it has been argued that human exposure to low doses of diagnostics X-rays and gamma-rays increase an individual's risk of developing cancer throughout their life-time. Also, repeated medical diagnostic procedures involving low dose exposures will have an additive effect and consequently further increase health risk. The specific aim of this seminar will be to address the relative risk associated with diagnostic X-rays from CT scans and gamma-rays from positron emission tomography (PET) scans. Objectives of the talk will include: 1) Defining low dose exposures at a cellular level and relate that to diagnostic or therapeutic exposures, 2) Describing modern tools in molecular cytogenetics to estimate radiation exposure and assess radiation risk, 3) Identifying the different cellular mechanisms that influence radiation risk at high and low dose exposures and relate that to individual radiation risk. (author)

  13. Human health effects of low doses of ionizing radiation: the BEIR III controversy

    Controversy in the BEIR III Subcommittee on Somatic Effects concerning human health effects of low doses of low-LET radiation has centered on (a) the appropriate dose-response relationship by which extrapolation to low doses of data obtained at relatively high doses should be governed, and (b) the appropriate human evidence which should be the basis of estimation of lifetime cancer risk from radiation exposure. It is shown that the use of the linear no-threshold dose-response relationship for extrapolation purposes is an excellent approximation that is in agreement with widely accepted fundamental radiobiological principles. The appropriate human data for derivation of cancer risks are the composite age-specific risks derived from all epidemiologic studies of human cancer resulting from partial-body and whole-body radiation exposure; this composite is in good agreement with the currently available cancer incidence dose-response data obtained from the Nagasaki Tumor Registry. The current version of BEIR III significantly underestimates the radiation-induced cancer risk because it ignores the effect of high-dose-rate, low-LET radiation on cell survival in relation to cancer induction probability, and because it emphasizes cancer mortality rather than cancer incidence. The controversy and the way in which it was resolved raises important questions about how the public and its representatives can in the future obtain objective scientific evaluations of issues that may have significant economic, social, and political implications

  14. Differential stimulation of antioxidant defense in various organs of mice after whole body exposure to low-dose gamma radiation

    It has been generally considered that any dose of ionizing radiation is detrimental to the living organisms, however low the radiation dose may be. The much relied upon 'Linear-No-Threshold' (LNT) hypothesis dose not have any convincing experimental evidence regarding the damaging effects at very low-doses and low-dose rates. Generally, the deleterious biological effects have been inferred theoretically by extrapolating the known effects of high radiation dose to low-dose range. Recently, it has been reported that the living organisms do not respond to ionizing radiations in a linear manner in the low-dose range 0.01-0.50 Gy and rather restore the homeostasis both in-vivo and in-vitro by normal physiological mechanisms such as, cellular and DNA repair processes, immune reactions, antioxidant defense, adaptive responses, activation of immune functions; stimulation of growth etc. In this study, we have attempted to find: (i) the critical radiation dose range and the post irradiation period during which the antioxidant defense systems in the lungs, liver and kidneys remain stimulated; and (ii) to evaluate the degree to which these defense mechanisms remain stimulated in these organs after whole body exposure of the animal to low-dose radiation

  15. From 'Image Gently' to image intelligently: a personalized perspective on diagnostic radiation risk

    The risk of ionizing radiation from diagnostic imaging has been a popular topic in the radiology literature and lay press. Communicating the magnitude of risk to patients and caregivers is problematic because of the uncertainty in estimates derived principally from epidemiological studies of large populations, and alternative approaches are needed to provide a scientific basis for personalized risk estimates. The underlying patient disease and life expectancy greatly influence risk projections. Research into the biological mechanisms of radiation-induced DNA damage and repair challenges the linear no-threshold dose-response assumption and reveals that individuals vary in sensitivity to radiation. Studies of decision-making psychology show that individuals are highly susceptible to irrational biases when judging risks. Truly informed medical decision-making that respects patient autonomy requires appropriate framing of radiation risks in perspective with other risks and with the benefits of imaging. To follow the principles of personalized medicine and treat patients according to their specific phenotypic and personality profiles, diagnostic imaging should optimally be tailored not only to patient size, body region and clinical indication, but also to underlying disease conditions, radio-sensitivity and risk perception and preferences that vary among individuals. (orig.)

  16. Radiation

    The basic facts about radiation are explained, along with some simple and natural ways of combating its ill-effects, based on ancient healing wisdom as well as the latest biochemical and technological research. Details are also given of the diet that saved thousands of lives in Nagasaki after the Atomic bomb attack. Special comment is made on the use of radiation for food processing. (U.K.)

  17. Applicability of the tissue stem cell turnover concept on the validity of cumulative dose based radiation risk evaluation

    The radiation protection system adopts the linear no-threshold model to achieve proper radiation protection for considering cancer risks resulting from radiation exposure. This model uses cumulative dose to a tissue for risk evaluation in which cumulative dose is related to the amount of DNA damage and consequential induction of gene mutation. In this concept, gene mutation accumulates in tissue stem cells, the putative target of carcinogenesis, with total dose given to the tissue. Unlike high-dose-rate exposure, epidemiological studies in high radiation background areas, such as Kerala in India, revealed that cancer risks is not elevated by the dose to the inhabitants, suggesting that there exists some mechanisms to eliminate the damage/mutation in the exposed tissue under extremely low-dose-rate exposure situations. In this report, the dynamics of tissue stem cell turnover is evaluated as a possible mechanism under extremely low-dose-rate exposure situations. To this end, we reviewed recent literatures studying tissue stem cell turnover, and found that great advances in stem cell research have made it possible to trace a fate of stem cells in tissues. Furthermore, turnover of tissue stem cells is found to occur after irradiation, due to competition of stem cells within tissues. This raises a possibility that radiation effects may not accumulate in a tissue depending on the dose-rate and duration of exposure period. (author)

  18. Report on the recently-updated study of cancer mortality in the A-bomb survivors: insights for radiation protection

    The Radiation Effects Research Foundation (RERF) in Hiroshima has recently released an updated study of cancer mortality in the Life Span Study (LSS) cohort of survivors of the atomic bombings at Hiroshima and Nagasaki. (The LSS is believed to contain about one-half of the total number of survivors who were within 2.5 km of the hypocentre.) The update has considerably more statistical power than previous studies because of five more years of follow-up(1986-1990 inclusive) and because of adding 10.536 survivors for whom DS86 dose estimates recently became available. Together these add about 550.000 person-years of follow-up compared to the previous report, which covered mortality to the end of 1985. Moreover, about 25% of the excess solid cancer deaths have occurred in these last five years of follow-up. Since the LSS is the most important source of information about the risk of induced cancer in humans following acute radiation exposures, this paper first summarizes this important new information. This is a keystone of radiation risk assessment and therefore of our radiation protection history; one cannot make sense of the current controversy concerning linearity without understanding what this data says and doesn't say. This communication then moves into a discussion of what implications there may be from this updated information, in the context of current debates about whether the linear-no threshold model is an appropriate one for radiation protection use. (DM)

  19. Radiation

    Exposure to solar and ionizing radiation increases the risk for cancer in humans. Some 5% of solar radiation is within the ultraviolet spectrum and may cause both malignant melanoma and non-melanocytic skin cancer; the latter is regarded as a benign disease and is accordingly not included in our estimation of avoidable cancers. Under the assumption that the rate of occurrence of malignant melanoma of the buttocks of both men and women and of the scalp of women would apply to all parts of the body in people completely unexposed to solar radiation, it was estimated that approximately 95% of all malignant melanomas arising in the Nordic populations around the year 2000 will be due to exposure to natural ultraviolet radiation, equivalent to an annual number of about 4700 cases, with 2100 in men and 2600 in women, or some 4% of all cancers notified. Exposure to ionizing radiation in the Nordic countries occurs at an average effective dose per capita per year of about 3 mSv (Iceland, 1.1 mSv) from natural sources, and about 1 mSv from man-made sources. While the natural sources are primarily radon in indoor air, natural radionuclides in food, cosmic radiation and gamma radiation from soil and building materials, the man-made sources are dominated by the diagnostic and therapeutic use of ionizing radiation. On the basis of measured levels of radon in Nordic dwellings and associated risk estimates for lung cancer derived from well-conducted epidemiological studies, we estimated that about 180 cases of lung cancer (1% of all lung cancer cases) per year could be avoided in the Nordic countries around the year 2000 if indoor exposure to radon were eliminated, and that an additional 720 cases (6%) could be avoided annually if either radon or tobacco smoking were eliminated. Similarly, it was estimated that the exposure of the Nordic populations to natural sources of ionizing radiation other than radon and to medical sources will each give rise to an annual total of 2120

  20. Atomic Bomb Survivors Life-Span Study: Insufficient Statistical Power to Select Radiation Carcinogenesis Model.

    Socol, Yehoshua; Dobrzyński, Ludwik

    2015-01-01

    The atomic bomb survivors life-span study (LSS) is often claimed to support the linear no-threshold hypothesis (LNTH) of radiation carcinogenesis. This paper shows that this claim is baseless. The LSS data are equally or better described by an s-shaped dependence on radiation exposure with a threshold of about 0.3 Sievert (Sv) and saturation level at about 1.5 Sv. A Monte-Carlo simulation of possible LSS outcomes demonstrates that, given the weak statistical power, LSS cannot provide support for LNTH. Even if the LNTH is used at low dose and dose rates, its estimation of excess cancer mortality should be communicated as 2.5% per Sv, i.e., an increase of cancer mortality from about 20% spontaneous mortality to about 22.5% per Sv, which is about half of the usually cited value. The impact of the "neutron discrepancy problem" - the apparent difference between the calculated and measured values of neutron flux in Hiroshima - was studied and found to be marginal. Major revision of the radiation risk assessment paradigm is required. PMID:26673526

  1. From 'Image Gently' to image intelligently: a personalized perspective on diagnostic radiation risk

    Guillerman, R.P. [Department of Pediatric Radiology, Texas Children' s Hospital, Baylor College of Medicine, Houston, TX (United States)

    2014-10-15

    The risk of ionizing radiation from diagnostic imaging has been a popular topic in the radiology literature and lay press. Communicating the magnitude of risk to patients and caregivers is problematic because of the uncertainty in estimates derived principally from epidemiological studies of large populations, and alternative approaches are needed to provide a scientific basis for personalized risk estimates. The underlying patient disease and life expectancy greatly influence risk projections. Research into the biological mechanisms of radiation-induced DNA damage and repair challenges the linear no-threshold dose-response assumption and reveals that individuals vary in sensitivity to radiation. Studies of decision-making psychology show that individuals are highly susceptible to irrational biases when judging risks. Truly informed medical decision-making that respects patient autonomy requires appropriate framing of radiation risks in perspective with other risks and with the benefits of imaging. To follow the principles of personalized medicine and treat patients according to their specific phenotypic and personality profiles, diagnostic imaging should optimally be tailored not only to patient size, body region and clinical indication, but also to underlying disease conditions, radio-sensitivity and risk perception and preferences that vary among individuals. (orig.)

  2. The dose-effect relationship and the estimation of carcinogen effects of low dose of ionizing radiation

    The carcinogen risks of an exposure to ionizing radiation have been evaluated by numerous epidemiological studies between 0.2 and 5 Sv. But the field of doses that concerns the human health is generally under a decade of mSv. The epidemiological studies do not detect any effect for doses under 100 mSv, either there is not or the statistical power of inquiries is not sufficient to detect them. Progress in radiobiology has shown that a cell is not passively affected by the accumulation of lesions induced by ionizing radiation. It react through at least three mechanisms: first, by fighting against reactive oxygen species (R.O.S.) generated by ionizing radiation and by oxidative stress, secondly, by eliminating injured cells (mutated or instable), through two mechanisms: apoptosis which can be initiated by doses as low as a few mSv, thus eliminating cells with genomes that have been damaged or mis-repaired, death of cells during mitosis when lesions have not been repaired, thirdly by stimulating or activating DNA repair systems following slightly higher doses of about ten mSv. About radio-carcinogenesis, with regard to tissue, the mechanisms which govern embryogenesis and direct tissue repair after injury appear to play also an important role in the control of cell proliferation. This is particularly important when a transformed cell is surrounded by normal cells. These mechanisms could explain the lower efficacy of heterogeneous irradiation as well as the absence of a carcinogenic effect in humans or experimental animals contaminated by small quantities of alpha emitter radionuclides. The latter data suggest the existence of a threshold. Immuno-surveillance systems are able to eliminate clones of transformed cells as is shown by tumor cell transplants. These data show that it is not justified to use linear no-threshold relationship to assess the carcinogenic risk of low doses from observations made for doses from .2 to 5 Sv since for the same dose increment the

  3. Regarding the Credibility of Data Showing an Alleged Association of Cancer with Radiation from CT Scans.

    Socol, Yehoshua; Welsh, James S

    2016-02-01

    Computed tomography (CT) scans are of high clinical value as a diagnostic technique, and new applications continue to be identified. However, their application is challenged by emerging concerns regarding carcinogenesis from their radiation. Recent articles made a significant contribution to the above-mentioned concerns by reporting evidence for direct association of the radiation from CT scans with cancer. Such interpretation of the data has already been criticized; there is the possibility of reverse causation due to confounding factors. Nevertheless, such work has had a high impact, with one article being cited more than 300 times from the Web of Science Core Collection within 2 years. However, the data points on cancer relative risk versus CT dose in that article fit straight lines corresponding to the linear no-threshold hypothesis suspiciously well. Here, by applying rigorous statistical analysis, it is shown that the probability of the fit truly being that good or better is only 2%. The results of such studies therefore appear "too good to be true" and the credibility of their conclusions must be questioned. PMID:25616624

  4. Some non-scientific influences on radiation protection standards and practice

    In this introductory lecture to the 5th International Congress of the IRPA, the problem of setting radiation protection standards and practice is broadly reviewed under the following headings:- 1) Biological effects of radiation, 2) Philosophy, 3) The Media, 4) Morality, (with particular reference to the problem of different classes of exposure) 5) Laws and Regulations (with particular reference to the U.S.) 6) Economics, 7) Education, 8) Credibility of scientists. It is suggested that because of their basic training in a sense of objectivity, a good argument can be made that scientists are as devoid of special interest as any other group. An argument is made that the problem of setting standards for protection can be reduced to a blending of two theories, a) that we are dealing with a single linear, no-threshold dose-effect relationship and b) the toxicological view that concentrations of a toxic substance should be set somewhat below that at which any effect could be found. (U.K.)

  5. How to understand the radiation effects of small dose - some critical comments on ICRP recommendations

    The widespread feeling of 'radiophobia' by the general public has its basis on the ICRP's 'linear no-threshold' hypothesis in dose-response relationship for low dose radiation from the standpoint of radiation protection. Although this common feeling served as a merit for constructing the 'safety culture' of society, it has now become a large obstacle for the development of peaceful uses of nuclear technology as a demerit. Recently many data have been accumulated for the radiation effects of low dose, both epidemiologically and experimentally. Although in general it is very difficult to obtain clear evidence of presence or absence of threshold, it seems to be true that the risk by radiation exposure at low level (the definition of which is below 0.2 Gy) is not so large as that of extrapolation from the high or medium dose range. In fact, many data suggest that some quite different mechanisms are working in low dose from high dose, such as 'adaptive response', and a new concept, 'radiation hormesis', has emerged, that the low level radiation is not only quite harmless but is rather necessary for living cells or beneficial for human health. In this paper, some critical comments on ICRP recommendations are given as a personal view by the author. These include: (1) a question of exact assessment of exposed dose by A-bomb survivors used for the epidemiological data, which are regarded to be the most authentic and important; (2) a brief summary of effects at the natural radiation level, including the high background area data; (3) the importance of dose rate effect, which reflects the living matter's repairability from radiation injury, and (4) the proposal of new paradigm by adopting the reasonable 'de minimis' level (below which there is no harm) both for low dose and at low dose rate. A simple mathematical analysis for representative data of dose rate effect was shown as an appendix

  6. How do we face low-dose radiation exposure

    Radio-contamination caused by Fukushima Daiichi Nuclear Power Plant Accident has spread to wide areas of the Prefecture and the present radiation level even in its capital Fukushima City is around 1 micro-Sv/h, 20 times as high as the past before the Accident. Japanese Government defines that the level <20 mSv/y is not hazardous to human health but residents always feel uneasiness. This paper describes about radiation problems present in administrative guidance from the scientific view. There are 3 different opinions about the health hazard of low dose exposure of <100 mSv/y: no influence, lower risk corresponding to lower dose (linear no threshold theory), and not always lower risk corresponding to lower dose. These are scientifically uncertain, and safety for radiation cannot be easily defined. Additional dose limit defined by Administration is 1 mSv/y for general public, to which compliance should be thought to be a prerequisite condition. The project of Fukushima Health Management Survey should be conducted in order to lessen the unnecessary exposure dose of residents as one of its aims. The most effective decontamination means are unknown at present, and therefore, whether the level of <1 mSv/y is attainable by decontamination of areas exceeding this is unknown. As seeable in easily declared safety of rice, people should not be overconfident in systems for monitoring urgently established after the accident. Three risk advisers invited by the Prefecture are saying that unnecessary exposure should be avoided, despite that they have the opinion of null risk at <100 mSv/y. The author comments that as the limited, insufficient information is said to lead the public to anxiety, confusion and finally panic, the Administration should not take a willful attitude tending to safety. (T.T.)

  7. Radiation risks of medical imaging: separating fact from fantasy.

    Hendee, William R; O'Connor, Michael K

    2012-08-01

    During the past few years, several articles have appeared in the scientific literature that predict thousands of cancers and cancer deaths per year in the U.S. population caused by medical imaging procedures that use ionizing radiation. These predictions are computed by multiplying small and highly speculative risk factors by large populations of patients to yield impressive numbers of "cancer victims." The risk factors are acquired from the Biological Effects of Ionizing Radiation (BEIR) VII report without attention to the caveats about their use presented in the BEIR VII report. The principal data source for the risk factors is the ongoing study of survivors of the Japanese atomic explosions, a population of individuals that is greatly different from patients undergoing imaging procedures. For the purpose of risk estimation, doses to patients are converted to effective doses, even though the International Commission on Radiological Protection warns against the use of effective dose for epidemiologic studies or for estimation of individual risks. To extrapolate cancer incidence to doses of a few millisieverts from data greater than 100 mSv, a linear no-threshold model is used, even though substantial radiobiological and human exposure data imply that it is not an appropriate model. The predictions of cancers and cancer deaths are sensationalized in electronic and print public media, resulting in anxiety and fear about medical imaging among patients and parents. Not infrequently, patients are anxious about a scheduled imaging procedure because of articles they have read in the public media. In some cases, medical imaging examinations may be delayed or deferred as a consequence, resulting in a much greater risk to patients than that associated with imaging examinations. © RSNA, 2012. PMID:22821690

  8. Frequency of somatic mutations in a population of occupationally exposed radiation workers

    Epidemiological studies of cancer incidence are unable to provide an accurate estimate of the excess risk due to low level radiation exposure. Advances in the understanding of the aetiology of malignant disease suggest an alternative approach. Cancer is induced by somatic mutations, therefore somatic mutation frequencies should correlate both with radiation exposure and with risk. This should be equally true of mutations which are not specific to cancer because radiation acts randomly on the genome. Mutation frequencies at the glycophorin-A (CPA) locus have previously been found to increase after high radiation doses. Here we demonstrate the application of the GPA assay to occupational exposure. A weak positive association was found between the ln of cumulative dose and ln of N0 variant cell frequency (p=0.04). This was not apparently confounded by age or smoking but was dependent on workers with doses greater than 500 mSv. The average N0 frequency per million cells for workers with doses up to 20 mSv was 9.43 (SD=8.76, n=77) compared to 19.72 (SD=15.42, n=16) for those with doses above 500 mSv. When tested using a likelihood ratio statistic the data were better fitted by a threshold model comparing those with doses above and below 500 mSv than by a linear, no-threshold model. Although this data set is relatively small it demonstrates the potential of using somatic mutations for resolving the current uncertainties about the effects of low does of radiation. With recent developments in molecular biology it should, in future, be possible to determine the frequency of specific cancer-associated mutations. (authors)

  9. Changing the paradigm: a radiation protection model for utilizing active systems in homeland defense applications

    Full text: The emerging threat from non-state actors and terrorist organizations openly asserting the use of weapons of mass destruction has led to an increased global emphasis on homeland defense and national security. The threat is real and thus many states are spending large amounts of resources to combat the problem. Issues such as unsecured radioactive sources, illicit movement of nuclear material, the use of radioactive sources in the medical and industrial sectors are just a few of the areas being examined. Countering these threats involves a major paradigm shift in the manner in which radiation is viewed. Radiation-based technologies are playing a key role in this emerging area from the development of new passive detection modalities to the use of active systems for detecting illicit materials. The screening of humans, baggage and cargo present overwhelming challenges. With these developments comes the concern from both governmental agencies and the public as to the safety of such systems. This paper will explore one such modality; the employment of radiation-based illicit material detection systems. The authors will present a review of the international (IAEA) and US regulatory and statutory documents as well as recommendations from scientific bodies such as the International Commission on Radiological Protection and the International Commission on Radiation Units and Measurements. This review coupled with sound scientific data are used to develop a proposed framework for the future employment of active systems for homeland defense applications. Issues considered include the ability to effectively measure and/or predict dose, is the As Low As Reasonably Achievable (ALARA) concept appropriate?, how much dose should be allowed relative to national security?, where does the linear-no-threshold hypothesis fit in? The authors use this analysis to develop a model which examines the trade-offs and cost-benefits in using the proposed systems. The major findings of

  10. The world's high background natural radiation areas (HBNRAs) revisited: A broad overview of the dosimetric, epidemiological and radiobiological issues

    The residents of the world's high background natural radiation areas (HBNRAs), such as Ramsar (in Iran), Guarapari (in Brazil), Orissa and Kerala (in India) and Yangjiang (in China) have lived in these areas for generations under extraordinary radiation fields. The failure of earlier epidemiological studies to report any substantial increase in cancer incidence in HBNRAs has raised some controversy regarding the validity of the linear no-threshold hypothesis. This paper reviews some of the most recent studies of HBNRAs with the intent of stimulating greater research interest in the dosimetric, epidemiological and radiobiological issues related to the world's HBNRAs and proposes solutions to the challenges facing HBNRA studies. This paper may serve as a useful reference for some of the harder-to-find literature. - Highlights: • Some of the challenging issues of HBNRAs have not been resolved. • A literature review of the most recent studies of HBNRAs has been conducted. • An overview of some of the challenging issues and viable solutions are presented

  11. Hyper-radiosensitivity and induced radioresistance and bystander effects in rodent and human cells as a function of radiation quality

    In the past two decades, a body of experimental evidences in vitro has shown the presence of a plethora of phenomena occurring after low-dose irradiation [including hypersensitivity and induced radioresistance (IRR), adaptive response, bystander effect (BE) and genomic instability], which might imply a non-linear behaviour of cancer risk curves in the low-dose region and question the validity of the linear no-threshold model for cancer risk assessment in such a dose region. In this framework, a systematic investigation have been undertaken on non-linear effects at low doses as a function of different radiation quality and cellular radiosensitivity and in terms of different biological end points. The present article reports the recent results on hyper-radiosensitivity and IRR and BE phenomena, in terms of clonogenic survival in V79 Chinese hamster cells and T98G human glioblastoma cells irradiated with protons and carbon ions with different energy, as a function of dose (and fluence). (authors)

  12. Evaluation of the detriment associated with exposure at low doses and low dose rates in the radiation protection system

    Questions about quantifying the radiological risk associated with exposure to ionising radiation have been debated repeatedly for a variety of exposure situations, including, among others, medical irradiation, discharges from nuclear facilities, transportation of radioactive waste, and potential nuclear accidents. This paper aims to shed light on the link between exposure and risk, focusing on the items that constitute the detriment associated with this exposure. The management of the risk associated with it relies on a cautious hypothesis of a linear no-threshold relation between exposure and risk of death or detriment. The International Commission on Radiological Protection (ICRP) published General Recommendations in 1966 that recognised this relation, but did not publish a quantification of the risk until 1977. The Commission introduced the concept of effective dose as a risk indicator that makes it possible to determine dose limits according to the risk associated with them. In 1990, the Commission proposed a revision of the quantification and construction of detriment. New limits, based on risk quantification and, for the first time, risk tolerability, were proposed. The optimisation of radiation protection - keeping radiation exposure as low as reasonably achievable in light of the economic and social context - became the key principle of the radiation protection system. The use of detriment makes it possible to use economic tools to guide the decision process for this optimisation - by assessing the monetary value of human life. This concept, widely used in health economics during the 1980's, has been criticised by many and must be used cautiously. ICRP published the latest quantifications of detriment in 2007. Detriment is thus an indicator that assesses the risk of death associated with exposure to ionising radiation for an average individual. Its construction relies on simplifying assumptions that are needed to implement a robust and effective radiation

  13. The evolution of and challenges for industrial radiation processing—2012

    Berejka, A. J.; Cleland, M. R.; Walo, M.

    2014-01-01

    The evolution of industrial radiation processing is traced from Roentgen's discovery of X-radiation in 1895 by following the development of high current, electron beam accelerators (EB) throughout the twentieth century. Although Becquerel soon followed Roentgen with his discovery of what became to be known as radioactivity, electrical sources for ionizing radiation dominate industrial processing with there being more than ten times as many industrial installations using high current EB equipment than the facilities relying upon large concentrations of radioactive isotopes. In the 1950s, the discovery that ionizing radiation would enhance the value of what has become the world's largest volume commodity plastic, polyethylene (PE), opened the way for full scale commercial use of high current EB equipment. While the crosslinking of the PE insulation on wire became one of the first major industrial applications, other uses of EB processing soon followed. In the 1970s, low-energy, self-shielded EB equipment made the surface curing of inks, coatings and adhesives more industrially viable. In the early part of the twenty-first century, new market applications involving the low-energy EB surface decontamination of packaging materials emerged. This new area poses challenges for the metrology needed to control industrial processes, in that there is limited EB penetration into what have been used as dosimeters by industry. Major industrial use of radiation process is now over 50 years old. Because of the diversity of end-uses and the fact that the use of ionizing radiation in industry is a process technique, it is hard to quantify the value-added to numerous commercial products that benefit from this energy efficient process. It may be in excess of a trillion Euros in value-added to articles of commerce. In this milieu, there are some broad-based opportunities for research which are noted.

  14. 50岁以上精神分裂症患者的认知特征%Clinical analysis of cognitive function in schizophrenic patients with age being more than 50 years old

    左小光; 杨甫德; 吉中孚

    2001-01-01

    Objective:To explore the characteristics and influence factors of cognitive impairment in schizophrenic patients (age≥50y). Method:Sixty schizophrenic patients and 40 normal controls were examined with Wisconsin card sorting test (WCST),Wechsler adult intelligence scale (WAIS-R),Wechsler memory scale (WMS),the language fluency test (LF),the finger tapping test (FTT),the brief psychiatric rating scale (BPRS) and the scale for the assessment of negative symptoms (SANS). Results:The cognitive functions in schizophrenia were reduced more significantly than that in controls.Age,illness duration,negative symptoms and subtype of diagnosis were associated with cognitive deficits in schizophrenia. Conclusion:The senile schizophrenic patients with long duration sever negative symptoms and non-paranoid type may have more obvious cognitive deficits.%目的:探讨50岁以上精神分裂症患者的认知损害特征及其影响因素。方法:对60例50岁以上精神分裂症患者和40例正常人进行了威斯康星卡片分类测验(WCST)、韦氏成人智力量表(WAIS-R)、韦氏记忆量表(WMS)、语言流利性测验(LF)、手指敲击测验(FTT)、简明精神病评定量表(BPRS)及阴性症状评定量表(SANS)等测查。结果:患者组的所有认知测查结果均较正常人显著减退,且年龄、病程,阴性症状及亚型对患者认知功能有显著影响。结论:年龄较大、病程较长、阴性症状较重及非偏执型的精神分裂症患者认知缺损严重。

  15. Evaluation the treatment outcomes of intracapsular femoral neck fractures with closed or open reduction and internal fixation by screw in 18-50-year-old patients in Isfahan from Nov 2010 to Nov 2011

    Mohammad Javdan

    2013-01-01

    Conclusion: This study showed that femoral neck fracture is associated with several complications, especially if open reduction was necessary. So, the surgical method and necessary equipments such as radiolucent bed, C-ARM machine, and implant cannulated screw set should be considered.

  16. Aged-Related Changes in Body Composition and Association between Body Composition with Bone Mass Density by Body Mass Index in Chinese Han Men over 50-year-old.

    Ying Jiang

    Full Text Available Aging, body composition, and body mass index (BMI are important factors in bone mineral density (BMD. Although several studies have investigated the various parameters and factors that differentially influence BMD, the results have been inconsistent. Thus, the primary goal of the present study was to further characterize the relationships of aging, body composition parameters, and BMI with BMD in Chinese Han males older than 50 years.The present study was a retrospective analysis of the body composition, BMI, and BMD of 358 Chinese male outpatients between 50 and 89 years of age that were recruited from our hospital between 2009 and 2011. Qualified subjects were stratified according to age and BMI as follows: 50-59 (n = 35, 60-69 (n = 123, 70-79 (n = 93, and 80-89 (n = 107 years of age and low weight (BMI: < 20 kg/m2; n = 21, medium weight (20 ≤ BMI < 24 kg/m2; n = 118, overweight (24 ≤ BMI < 28 kg/m2; n = 178, and obese (BMI ≥ 28 kg/m2; n = 41. Dual-energy X-ray absorptiometry (DEXA was used to assess bone mineral content (BMC, lean mass (LM, fat mass (FM, fat-free mass (FFM, lumbar spine (L1-L4 BMD, femoral neck BMD, and total hip BMD. Additionally, the FM index (FMI; FM/height2, LM index (LMI; LM/height2, FFM index (FFMI; [BMC+LM]/height2, percentage of BMC (%BMC; BMC/[BMC+FM+LM] × 100%, percentage of FM (%FM; FM/[BMC+FM+LM] × 100%, and percentage of LM (%LM; LM/(BMC+FM+LM × 100% were calculated. Osteopenia or osteoporosis was identified using the criteria and T-score of the World Health Organization.Although there were no significant differences in BMI among the age groups, there was a significant decline in height and weight according to age (p < 0.0001 and p = 0.0002, respectively. The LMI and FFMI also declined with age (both p < 0.0001 whereas the FMI exhibited a significant increase that peaked in the 80-89-years group (p = 0.0145. Although the absolute values of BMC and LM declined with age (p = 0.0031 and p < 0.0001, respectively, there was no significant difference in FM. In terms of body composition, there were no significant differences in %BMC but there was an increase in %FM (p < 0.0001 and a decrease in %LM (p < 0.0001 with age. The femoral neck and total hip BMD significantly declined with age (p < 0.0001 and p = 0.0027, respectively but there were no differences in L1-L4. BMD increased at all sites (all p < 0.01 as BMI increased but there were declines in the detection rates of osteoporosis and osteopenia (both p < 0.001. A logistic regression revealed that when the medium weight group was given a BMI value of 1, a decline in BMI was an independent risk factor of osteoporosis or osteopenia, while an increase in BMI was a protective factor for BMD. At the same time, BMD in L1-L4 exhibited a significant positive association with FMI (p = 0.0003 and the femoral neck and total hip BMDs had significant positive associations with FFMI and LMI, respectively (both p < 0.0001.These data indicate that LMI and FFMI exhibited significant negative associations with aging in Chinese Han males older than 50 years, whereas FMI had a positive association. BMD in the femoral neck and total hip declined with age but an increased BMI was protective for BMD. LMI and FFMI were protective for BMD in the femoral neck and total hip.

  17. A case of radiation induced carcinoma of the cervical esophagus

    A patient with carcinoma of the cervical esophagus who visited a hospital with a complaint of difficulty in swallowing was reported. This patient was a 50 year old woman. It was 32 years since she had had external irradiation with x- ray over the neck for Basedow's disease at the age of 18. From the age of 30, she had had hypothyroidism and had used thyroid. She became aware of difficulty in swallowing in October, 1976. Then this symptom progressed gradually, and she also had hoarseness. She visited a hospital in August, 1977. At the first medical examination, pigmentation and atrophic changes in the neck induced by radiation were observed, and some lymphnodes with the size of a red bean were palpated. Esophageal roentogenography revealed circular and spiral type lesion in the cervical esophagus, which was 4 cm in length and had a clear boundary. Endoscopic examination revealed circular stenotic lesion. This lesion was diagnosed as squamous cell carcinoma by biopsy. Total of 3,000 rad of Linac x-ray was irradiated over the neck and the clavicle before operation. Operation findings revealed fibrosis, atrophy, and hardening of the thyroid gland caused by radiation. Carcinoma with the size 35 mm x 18 mm was limited to the cervical esophagus, and the degree of the progress was A2, N2, M0 (Pl0). Histological findings revealed moderately differentiated squamous cell carcinoma and its metastases to the right supraclaviclar lymphnodes. This carcinoma was diagnosed as radiation-induced carcinoma of the cervical esophagus, because this patient had had irradiation over the neck, locally marked atrophic changes and scar remained, and carcinoma occurred in the area which had been irradiated with x-ray. (Tsunoda, M.)

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

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

  19. The evolution of and challenges for industrial radiation processing—2012

    The evolution of industrial radiation processing is traced from Roentgen's discovery of X-radiation in 1895 by following the development of high current, electron beam accelerators (EB) throughout the twentieth century. Although Becquerel soon followed Roentgen with his discovery of what became to be known as radioactivity, electrical sources for ionizing radiation dominate industrial processing with there being more than ten times as many industrial installations using high current EB equipment than the facilities relying upon large concentrations of radioactive isotopes. In the 1950s, the discovery that ionizing radiation would enhance the value of what has become the world's largest volume commodity plastic, polyethylene (PE), opened the way for full scale commercial use of high current EB equipment. While the crosslinking of the PE insulation on wire became one of the first major industrial applications, other uses of EB processing soon followed. In the 1970s, low-energy, self-shielded EB equipment made the surface curing of inks, coatings and adhesives more industrially viable. In the early part of the twenty-first century, new market applications involving the low-energy EB surface decontamination of packaging materials emerged. This new area poses challenges for the metrology needed to control industrial processes, in that there is limited EB penetration into what have been used as dosimeters by industry. Major industrial use of radiation process is now over 50 years old. Because of the diversity of end-uses and the fact that the use of ionizing radiation in industry is a process technique, it is hard to quantify the value-added to numerous commercial products that benefit from this energy efficient process. It may be in excess of a trillion Euros in value-added to articles of commerce. In this milieu, there are some broad-based opportunities for research which are noted. - Highlights: ► The evolution of industrial radiation processing is traced from

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

    adaptive response seems to be the manifestation of a protective effect that may reduce risk at very low doses. Current knowledge in molecular biology shows no evidence of a threshold effect for Stochastic Effects. Therefore, any level of radiation may be considered to cause them. Conversely, some studies show that low levels of irradiation are in fact beneficial to the health (Radiation Hormesis). However, in the absence of clear scientific evidence, the regulators adopted a conservative approach and consider all levels of radiation as being potentially damaging to the human body (LNT theory). According to LNT theory; the effects of low doses of ionizing radiation can be estimated by linear extrapolation from effects observed by linear extrapolation from effects observed by high doses. There is not any safe dose because even very low doses of ionizing radiation produce some biological effect. The results of many investigations do not support the LNT theory. Furthermore relationship between environmental radon concentrations and lung cancer even contradict this theory and clearly suggest a hermetic effect -radiation hormesis-. Although data are still incomplete, extensive epidemiological studies have indicated that radiation hormesis is really exist. In this review, contradictory evidence Linear No-Threshold Theory and Radiation Hormesis Effect is discussed

  1. PREFACE: Radiation Damage in Biomolecular Systems (RADAM07)

    McGuigan, Kevin G.

    2008-03-01

    The annual meeting of the COST P9 Action `Radiation damage in biomolecular systems' took place from 19-22 June 2007 in the Royal College of Surgeons in Ireland, in Dublin. The conference was structured into 5 Working Group sessions: Electrons and biomolecular interactions Ions and biomolecular interactions Radiation in physiological environments Theoretical developments for radiation damage Track structure in cells Each of the five working groups presented two sessions of invited talks. Professor Ron Chesser of Texas Tech University, USA gave a riveting plenary talk on `Mechanisms of Adaptive Radiation Responses in Mammals at Chernobyl' and the implications his work has on the Linear-No Threshold model of radiation damage. In addition, this was the first RADAM meeting to take place after the Alexander Litvenenko affair and we were fortunate to have one of the leading scientists involved in the European response Professor Herwig Paretzke of GSF-Institut für Strahlenschutz, Neuherberg, Germany, available to speak. The remaining contributions were presented in the poster session. A total of 72 scientific contributions (32 oral, 40 poster), presented by 97 participants from 22 different countries, gave an overview on the current progress in the 5 different subfields. A 1-day pre-conference `Early Researcher Tutorial Workshop' on the same topic kicked off on 19 June attended by more than 40 postgrads, postdocs and senior researchers. Twenty papers, based on these reports, are included in this volume of Journal of Physics: Conference Series. All the contributions in this volume were fully refereed, and they represent a sample of the courses, invited talks and contributed talks presented during RADAM07. The interdisciplinary RADAM07 conference brought together researchers from a variety of different fields with a common interest in biomolecular radiation damage. This is reflected by the disparate backgrounds of the authors of the papers presented in these proceedings

  2. Low doses of ionizing radiation: Relationship between biological benefit and damage induction. A synopsis

    damage at high doses but protection at low doses. This low-dose induced protection mainly functions against accumulation of DNA damage from endogenous sources, such as ROS. Bystander effects from high-dosed cells to non-irradiated neighboring cells appear to induce both damage and protection. With respect to oncogenesis, a model using microdosimetry and based on the above dual response pattern at low doses and dose rates is consistent with published non-linear epidemiological and experimental data and, thus, contradicts the linear-no-threshold dose-risk hypothesis for radiation induced cancer. The LNT hypothesis should be abandoned and be replaced by a hypothesis that is scientifically justified and causes less unreasonable fear and unnecessary expenditure. (author)

  3. Energy and entropy in radiation dosimetry and protection

    Oliveira, A.D. [Instituto Tecnologico e Nuclear, Dept. de Proteccao Radiologica e Seguranca Nuclear (Portugal)

    2006-07-01

    In this work we present and discuss a proposal to describe the degradation of the energy of photons when they interact with matter, which can be applied in radiation dosimetry and protection. Radiation dosimetry is founded in the well known physical approach of field theory as showed by Roesch and Rossi. Fluence and energy deposited are the most fundamental quantities in radiation dosimetry allowing us to calculate absorbed dose. One of the main characteristics of absorbed dose, sometimes ignored, is that it is an intensive quantity pushing radiation dosimetry into the field of statistical physics. In radiation dosimetry it is often used what we can call collective or macroscopic concepts, such as, for example, effective energy, beam quality or beam hardening and absorbed dose. Some of these concepts are trials to describe macroscopically and with simplicity what happens microscopically with a rather higher degree of complexity. In other words, is a tentative to make a bridge between the non continuous world of atoms and photons to the continuous world of radiation protection dosimetry. In computer simulations, that allow to known accurately the energy deposited in matter, absorbed dose (or fluence) is still a very useful and used quantity; however, some issues are still open problems, source of many discussions in conferences and journals in spite of the development of microdosimetry and nano-dosimetry. In spite of that, macroscopic quantities like absorbed dose are still important quantities. One of the important and controversial open question in biological effects at low doses is the linear no threshold concept (L.N.T.). In our opinion this problem is directly related with the problem mentioned above of the bridge between microscopic and macroscopic concepts. Actually, the extrapolation to low dose region is a good expression of the challenge we have to deal in order to make the connections between both worlds, the discrete micro-world to the continuous macro

  4. Energy and entropy in radiation dosimetry and protection

    In this work we present and discuss a proposal to describe the degradation of the energy of photons when they interact with matter, which can be applied in radiation dosimetry and protection. Radiation dosimetry is founded in the well known physical approach of field theory as showed by Roesch and Rossi. Fluence and energy deposited are the most fundamental quantities in radiation dosimetry allowing us to calculate absorbed dose. One of the main characteristics of absorbed dose, sometimes ignored, is that it is an intensive quantity pushing radiation dosimetry into the field of statistical physics. In radiation dosimetry it is often used what we can call collective or macroscopic concepts, such as, for example, effective energy, beam quality or beam hardening and absorbed dose. Some of these concepts are trials to describe macroscopically and with simplicity what happens microscopically with a rather higher degree of complexity. In other words, is a tentative to make a bridge between the non continuous world of atoms and photons to the continuous world of radiation protection dosimetry. In computer simulations, that allow to known accurately the energy deposited in matter, absorbed dose (or fluence) is still a very useful and used quantity; however, some issues are still open problems, source of many discussions in conferences and journals in spite of the development of microdosimetry and nano-dosimetry. In spite of that, macroscopic quantities like absorbed dose are still important quantities. One of the important and controversial open question in biological effects at low doses is the linear no threshold concept (L.N.T.). In our opinion this problem is directly related with the problem mentioned above of the bridge between microscopic and macroscopic concepts. Actually, the extrapolation to low dose region is a good expression of the challenge we have to deal in order to make the connections between both worlds, the discrete micro-world to the continuous macro

  5. The Very High Background Radiation Area in Ramsar, Iran: Public Health Risk or Signal for a Regulatory Paradigm Shift?

    Karam, P. Andrew [Univ. of Rochester, Rochester, NY (United States); Mortazavi, S.M. Javad [Rafsanjan Univ. of Medical Sciences (Iran, Islamic Republic of). Medical Physics Dept.

    2001-07-01

    Ramsar, a city on the Caspian Sea in northern Iran hosts the highest measured natural background radiation levels in the world. These are due to the local geology and hydrogeology and, in some places, deliver radiation doses far in excess of those recommended for radiation workers. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy/yr and the highest recorded doses are about 260 mGy/yr. These high radiation levels are due to the deposition of {sup 226}Ra in local rocks and, because these rocks are used in the construction of many local houses, interior radiation levels are often similar to those found outside. The presence of areas such as Ramsar raises an interesting public health policy question: Is it necessary to relocate the inhabitants to areas of lower natural background radiation levels in the interests of public health? According to the linear, no-threshold (LNT) hypothesis, there is no doubt that relocating the population of Ramsar will result in a reduction in cancer incidence. Therefore, under any reasonable policy based on the LNT hypothesis, the public health is best served by relocating many of Ramsar's inhabitants to other areas along the Caspian Sea. At present, there is no reliable epidemiological data on cancer incidence among the inhabitants of Ramsar's high background radiation areas (HBRAs), but local physicians feel that local cancer incidence rates are lower than in neighboring cities. Furthermore, preliminary results indicate that there is a statistically significant radio adaptation in the inhabitants of Ramsar. Interestingly, it seems that the frequency of chromosome aberrations in the lymphocytes of the inhabitants of Ramsar is no higher than the control areas. This important finding suggests that the cancer rate in Ramsar should be no higher than in other comparable parts of Iran. In other HBRAs such as Yangjiang, China it has been reported that mortality from all cancers and those from

  6. The Very High Background Radiation Area in Ramsar, Iran: Public Health Risk or Signal for a Regulatory Paradigm Shift?

    Ramsar, a city on the Caspian Sea in northern Iran hosts the highest measured natural background radiation levels in the world. These are due to the local geology and hydrogeology and, in some places, deliver radiation doses far in excess of those recommended for radiation workers. A population of about 2000 is exposed to average annual radiation levels of 10.2 mGy/yr and the highest recorded doses are about 260 mGy/yr. These high radiation levels are due to the deposition of 226Ra in local rocks and, because these rocks are used in the construction of many local houses, interior radiation levels are often similar to those found outside. The presence of areas such as Ramsar raises an interesting public health policy question: Is it necessary to relocate the inhabitants to areas of lower natural background radiation levels in the interests of public health? According to the linear, no-threshold (LNT) hypothesis, there is no doubt that relocating the population of Ramsar will result in a reduction in cancer incidence. Therefore, under any reasonable policy based on the LNT hypothesis, the public health is best served by relocating many of Ramsar's inhabitants to other areas along the Caspian Sea. At present, there is no reliable epidemiological data on cancer incidence among the inhabitants of Ramsar's high background radiation areas (HBRAs), but local physicians feel that local cancer incidence rates are lower than in neighboring cities. Furthermore, preliminary results indicate that there is a statistically significant radio adaptation in the inhabitants of Ramsar. Interestingly, it seems that the frequency of chromosome aberrations in the lymphocytes of the inhabitants of Ramsar is no higher than the control areas. This important finding suggests that the cancer rate in Ramsar should be no higher than in other comparable parts of Iran. In other HBRAs such as Yangjiang, China it has been reported that mortality from all cancers and those from leukemia, breast and

  7. A database for a meta-analysis of cancer risk in animals at low doses and dose rates of ionising radiation

    Results of animal experiments listed in the International Radiobiology Archives (I.R.A.), complemented with data published in peer-reviewed literature since 1996 have been assembled in one data base and the induction of cancer at low doses has been analyzed. In total, approximately 100 separate, independent sets of experimental data have been studied. The main objective of this work is to provide information on radiation risk in the 0-500 mGy range. The data analyzed were those for which no significant reduction of life span was observed in exposed animals; or doses did not exceed 1 Gy; or no cancer was observed in exposed animals. With these criteria data sets with organ doses well in excess of 1 Gy were taken into account. In animals with a low natural incidence of cancer, the difference between the observed number of cancer cases and the prediction of the Linear No-threshold (LNT) hypothesis was compared in each experiment. Following intake of alpha emitters, the number of cancers observed is about 60% of the number of number predicted by the LNT, and only about 56% following intake of beta emitters. In some experiments, statistically weak protective effects were observed following the intake of alpha emitters, whereas apparently statistically strong protective effects were observed in some groups of animals exposed to beta radiation. In animals exposed to low LET radiation and neutrons, both clear excess cancer risk and clear cancer deficits were observed. In a second series of analysis, the several modeling approaches were used to model dose-response. Linear, logistic and probit regression models were examined. For all the data sets examined in this work, the analysis of the data using the LOGISTIC model seems to indicate surplus of negative slopes in the dose-response fits. Finer analyses are underway to determine what parameters are common to experiments which display similar dose-response relationships. If they exist in a sufficient number of experiments

  8. Radiation risk associated with mammography screening examinations for women younger than 50 years of age

    The target group of the German mammography screening program, conducted according to the European guidelines, is clearly defined: all women aged 50 to 69 years without evidence of breast cancer are invited to screening mammography every two years. In the present study the question was raised whether breast cancer screening by means of mammography is - from the point of view of radiation hygiene - justified also for women under 50 years of age. Based on current radio-epidemiological breast cancer studies, the excess lifetime risk (ELR) to incur or die from breast cancer of a 40, 45 and 50 year old woman was assessed. Different risk models were used to estimate the radiation risk, e.g. models given for the 'Life Span Study' of the atomic bomb survivors and the risk model given in the recent Biological Effects of Ionizing Radiation (BEIR) VII report. The benefit risk ratio was defined as the ratio of the number of 'saved lives' due to screening to the number of deaths due to 'radiation induced breast cancer'. All estimations were based on the assumption that screening is taking place up to the age of 69 years, with screening examinations being performed annually up to the age of 50 and every two years from the age of 50 onwards. The glandular dose per two-view mammography investigation was assumed to be 4 mGy. The benefit due to mammography screening was assumed to be 25% for all age groups. Assuming screening from the age of 40 or 45 years, the ELR of breast cancer is on average about 3.5 or 2 times as high compared to the ELR associated with screening starting from the age of 50 years. In comparison to the benefit risk ratio, which results for women participating in a mammography screening from the age of 50 years, the benefit risk ratio for women starting with screening already from the age of 40 or 45 years is reduced by a factor of 3 or 2. With the present data - with regard to both, the benefit and the radiation risk - it appears not to be justified to expose

  9. Radiation dosimetry.

    Cameron, J.

    1991-01-01

    This article summarizes the basic facts about the measurement of ionizing radiation, usually referred to as radiation dosimetry. The article defines the common radiation quantities and units; gives typical levels of natural radiation and medical exposures; and describes the most important biological effects of radiation and the methods used to measure radiation. Finally, a proposal is made for a new radiation risk unit to make radiation risks more understandable to nonspecialists.

  10. A study on the efficacy and adverse effects of post-operative beta-radiation in the prevention of recurrence of Pterygium

    Beta irradiation by Strontium (Sr-90) has been in use for about 20 years in Bangladesh. This retrospective analysis was performed to evaluate its efficacy and the risk and incidence of complications, both short-term and long-term. A retrospective analysis was done of all 417 patients receiving post-operative beta irradiation from January 2001 to January 2006.There were 303 males and 114 females, age ranged from 18 to 65 years with a mean of 38 years. Each patient received 2500cGy to the post-operative sclera surface in five fractions by hand held Sr-90 surface applicator from Amersham International. The patients were followed up at one week, one month, six months and one year after beta irradiation. All 417 cases reported for follow up at one week. But then gradually some patients did not turn up according to the schedule. The number of patients who reported for follow up at one month, 6 months and one year were 401, 325 and 288 respectively. Eighteen cases had recurrence within one year and received a second dose of beta radiation. Short-term complications included conjunctivitis, photophobia, watering of eyes etc. As for long term complications, two patients developed cataract and one patient developed ophthalmomalacia. The short-term complications were self limiting and had no serious effects. The two cases who developed cataracts were over 50 years old, so it could not be clearly understood whether the normal ageing process or the radiation contributed more in the development of the cataract. The rare ophthalmo-malacia developed in a case, which had simultaneous Graves' disease. All other patients in the study are doing well with significant improvement in visual acuity. The results of this retrospective study reveal that Sr- 90 beta irradiation is an effective and safe treatment option to prevent recurrence of Pterygium. (author)

  11. Isotropic Radiators

    Matzner, H; Matzner, Haim; Donald, Kirk T. Mc

    2003-01-01

    We give two examples of antennas with isotropic radiation patterns. Because these involve elliptically polarized radiation, they evade the "hairy-ball theorem" that suggests isotropic radiation would be impossible.

  12. Radiation protection

    This work define procedures and controls about ionizing radiations. Between some definitions it found the following topics: radiation dose, risk, biological effects, international radioprotection bodies, workers exposure, accidental exposure, emergencies and radiation protection

  13. Radiation dosimetry

    Hine, Gerald J; Hine, Gerald J

    1956-01-01

    Radiation Dosimetry focuses on the advancements, processes, technologies, techniques, and principles involved in radiation dosimetry, including counters and calibration and standardization techniques. The selection first offers information on radiation units and the theory of ionization dosimetry and interaction of radiation with matter. Topics include quantities derivable from roentgens, determination of dose in roentgens, ionization dosimetry of high-energy photons and corpuscular radiations, and heavy charged particles. The text then examines the biological and medical effects of radiation,

  14. Radiation Hydrodynamics

    Mihalas, Dimitri

    Basic Radiation Theory Specific Intensity Photon Number Density Photon Distribution Function Mean Intensity Radiation Energy Density Radiation Energy Flux Radiation Momentum Density Radiation Stress Tensor (Radiation Pressure Tensor) Thermal Radiation Thermodynamics of Thermal Radiation and a Perfect Gas The Transfer Equation Absorption, Emission, and Scattering The Equation of Transfer Moments of the Transfer Equation Lorentz Transformation of the Transfer Equation Lorentz Transformation of the Photon 4-Momentum Lorentz Transformation of the Specific Intensity, Opacity, and - Emissivity Lorentz Transformation of the Radiation Stress Energy Tensor The Radiation 4-Force Density Vector Covariant Form of the Transfer Equation Inertial-Frame Equations of Radiation Hydrodynamics Inertial-Frame Radiation Equations Inertial-Frame Equations of Radiation Hydrodynamics Comoving-Frame Equation of Transfer Special Relativistic Derivation (D. Mihalas) Consistency Between Comoving-Frame and Inertial-Frame Equations Noninertial Frame Derivation (J. I. Castor) Analysis of O (v/c) Terms Lagrangian Equations of Radiation Hydrodynamics Momentum Equation Gas Energy Equation First Law of Thermodynamics for the Radiation Field First Law of Thermodynamics for the Radiating Fluid Mechanical Energy Equation Total Energy Equation Consistency of Different Forms of the Radiating-Fluid Energy - and Momentum Equations Consistency of Inertial-Frame and Comoving-Frame Radiation Energy - and Momentum Equations Radiation Diffusion Radiation Diffusion Nonequilibrium Diffusion The Problem of Flux Limiting Shock Propagation: Numerical Methods Acoustic Waves Numerical Stability Systems of Equations Implications of Shock Development Implications of Diffusive Energy Transport Illustrative Example Numerical Radiation Hydrodynamics Radiating Fluid Energy and Momentum Equations Computational Strategy Energy Conservation Formal Solution Multigroup Equations An Astrophysical Example Adaptive-Grid Radiation

  15. Total Risk Management for Low Dose Radiation Exposures

    Our civilization is witnessing about century of nuclear age mixed with enormous promises and cataclysmic threats. Nuclear energy seems to encapsulate both potential for pure good and evil or at least we humans are able to perceive that. These images are continuously with us and they are both helping and distracting from making best of nuclear potentials for civilization. Today with nuclear use significantly present and with huge potential to further improve our life with energy and medical use it is of enormous importance to try to have calmed, rational, and objective view on potential risks and certain benefits. Because all use of nuclear energy proved that their immediate risks are negligible (i.e., Three Mile Island and Fukushima) or much smaller than from the other alternatives (i.e., Chernobyl) it seems that the most important issue is the amount of risk from the long term effects to people from exposure to small doses of radiation. A similar issue is present in the increased use of modern computational tomography and other radiation sources use in medicine for examination and therapy. Finally, extreme natural exposures are third such potential risk sources. Definition of low doses varies depending on the way of delivery (i.e., single, multiple or continuous exposures), and for this paper usual dose of 100 mSv is selected as yearly upper amount. There are three very different scientifically supported views on the potential risks from the low doses exposure. The most conservative theory is that all radiation is harmful, and even small increments from background levels (i.e., 2-3 mSv) present additional risk. This view is called linear no threshold theory (LNT) and it is accepted as a regulatory conservative simple approach which guarantees safety. Risk is derived from the extrapolation of the measured effects of high levels of radiation. Opposite theory to LNT is hormesis which assumes that in fact small doses of radiation are helpful and they are improving our

  16. Radiation carcinogenesis

    This general discussion is dealt with under the following headings: problems of collecting information (epidemiology, experimental animal studies), the temporal stages of radiation action (physical and chemical effects and cellular response), human cancer, radiation dose and risk, epidemiology and dose-response relationships, cellular and molecular processes (cell inactivation, chromosome damage and cell mutation, radiation transformation, virus and oncogene activation, free radical aspects of radiation carcinogenesis, interaction of radiation and chemical carcinogens. (U.K.)

  17. Mulheres com idade igual ou superior a 50 anos: ações preventivas da infecção pelo HIV Mujeres com edad igual o superior a 50 años: acciones preventivas de la infección por el VIH The 50-year-old women or older: preventive actions to the HIV infection

    Daniela Angelo de Lima Rodrigues

    2010-06-01

    Full Text Available Trata-se de pesquisa qualitativa que buscou verificar a adoção de ações preventivas da transmissão do HIV por mulheres com idade igual ou superior a 50 anos, moradoras em uma comunidade de baixa renda e atendidas pelo Programa Saúde da Família, no Município de São Paulo. Adotou-se como referencial teórico a Antropologia Médica e, para o tratamento dos dados, o Discurso do Sujeito Coletivo. Foram entrevistadas 13 mulheres e são apresentados três discursos: valorizando a prevenção; invisibilidade do HIV/aids; e rejeição à adesão ao preservativo. A análise mostrou que o grupo não se percebia em risco à infecção pela via sexual devido à confiança na fidelidade do parceiro. O eventual uso do preservativo foi atribuído somente à curiosidade. As ações preventivas adotadas carecem de embasamento científico. Os resultados alertam para a necessidade do planejamento e da implementação de intervenções culturalmente embasadas direcionadas ao segmento estudado.Se trata de una investigación cualitativa que buscó verificar la adopción de acciones preventivas de la transmisión del VIH por mujeres con edad igual o superior a 50 años, moradoras en una comunidad de baja renta y atendidas por el Programa Salud de la Familia, en el municipio de São Paulo, Brasil. Se adoptó como referencial teórico la Antropología Médica y, para el tratamiento de los datos, el Discurso del Sujeto Colectivo. Se entrevistaron 13 mujeres y son presentados tres discursos: valorar la prevención; invisibilidad del VIH/SIDA; rechazo a la adherencia al preservativo. El análisis apuntó que el grupo no percibió el riesgo a la infección por la vía sexual a causa de la confianza en la fidelidad del compañero. El eventual uso del preservativo fue atribuido solamente a la curiosidad. Las acciones preventivas adoptadas carecen de base científica. Los resultados alertan para la necesidad del planeamiento y de la implantación de intervenciones culturalmente basadas direccionada al seguimiento estudiado.The present study is a qualitative research which aimed to verify the adoption of preventive measures on the transmission of HIV in women aged 50 or over it, who live in poor communities and were followed by the Family Health Program in São Paulo, Brazil. Medical Anthropology has been adopted as a theoretical reference as well as the Discourse of the Collective Individual for data analysis. There have been 13 women interviewed and three discourses have been presented: prevention appreciation, invisibility of HIV/aids and the rejection of the use of condom. The analysis has shown that the group did not realize the risk of contamination through sexual intercourse due to trust in their partners' loyalty. The casual use of condoms was taken into consideration just out of curiosity. The preventive actions adopted need more scientific basis. The results point out the necessity of planning and implementation of interventions which are culturally based and directed to the studied segment.

  18. 深圳市东部地区50岁以上人群骨退行性变的危险因素分析%Risk Factors of Crowd Bone Degeneration for People Over 50 Years Old in the Eastern Region of Shenzhen

    黄仁辉; 张大敏; 罗杰

    2013-01-01

      目的:对深圳市东部地区215名50岁以上患有骨退行性变人群的自然状况进行分析,找出其退行性变的危险因素。方法:测定215名50岁以上人群的骨密度(BMD),计算出T评分,诊断其是否发生骨质疏松,以该人群的年龄、性别、身高、民族、有无家族史、有无外伤史、职业、是否发生骨质疏松等作为自变量,以是否发生骨退行性变为因变量进行多因素的logistic回归分析。结果:最终进入模型的影响因素有:性别、有无外伤史、是否发生骨质疏松。结论:50岁以上人群中性别、有外伤史和患有骨质疏松症是发生骨退行性变的危险因素。%Objective:Shenzhen City, the eastern part of 215 over age 50 suffer from bone degeneration crowd natural conditions were analyzed to identify the risk factors for its degeneration.Methods:215 people over the age of 50, bone mineral density (BMD), to calculate the T score, a diagnosis of osteoporosis, the age of the population, gender, height, ethnicity, whether the family history, with or without history of trauma,occupation,osteoporosis,etc.as independent variables into a multivariate logistic regression analysis the dependent variable to the occurrence of bone degeneration.Results:The final influencing factors into the model: sex, history of trauma, the occurrence of osteoporosis. Conclusion:People over the age of 50, sex, history of trauma and patients with osteoporosis is bone degeneration risk factors.

  19. Dose assessment for the fetus considering scattered and secondary radiation from photon and proton therapy when treating a brain tumor of the mother

    Geng, Changran; Moteabbed, Maryam; Seco, Joao; Gao, Yiming; Xu, X. George; Ramos-Méndez, José; Faddegon, Bruce; Paganetti, Harald

    2016-01-01

    The goal of this work was to determine the scattered photon dose and secondary neutron dose and resulting risk for the sensitive fetus from photon and proton radiotherapy when treating a brain tumor during pregnancy. Anthropomorphic pregnancy phantoms with three stages (3-, 6-, 9-month) based on ICRP reference parameters were implemented in Monte Carlo platform TOPAS, to evaluate the scattered dose and secondary neutron dose and dose equivalent. To evaluate the dose equivalent, dose averaged quality factors were considered for neutrons. This study compared three treatment modalities: passive scattering and pencil beam scanning proton therapy (PPT and PBS) and 6-MV 3D conformal photon therapy. The results show that, for 3D conformal photon therapy, the scattered photon dose equivalent to the fetal body increases from 0.011 to 0.030 mSv per treatment Gy with increasing stage of gestation. For PBS, the neutron dose equivalent to the fetal body was significantly lower, i.e. increasing from 1.5  ×  10-3 to 2.5  ×  10-3 mSv per treatment Gy with increasing stage of gestation. For PPT, the neutron dose equivalent of the fetus decreases from 0.17 to 0.13 mSv per treatment Gy with the growing fetus. The ratios of dose equivalents to the fetus for a 52.2 Gy(RBE) course of radiation therapy to a typical CT scan of the mother’s head ranged from 3.4-4.4 for PBS, 30-41 for 3D conformal photon therapy and 180-500 for PPT, respectively. The attained dose to a fetus from the three modalities is far lower than the thresholds of malformation, severe mental retardation and lethal death. The childhood cancer excessive absolute risk was estimated using a linear no-threshold dose-response relationship. The risk would be 1.0 (95% CI: 0.6, 1.6) and 0.1 (95% CI:  -0.01, 0.52) in 105 for the 9-month fetus for PBS with a prescribed dose of 52.2 Gy(RBE). The increased risks for PPT and photon therapy are about two and one orders of magnitude larger than that for PBS

  20. Evaluation of Fe and Zn/Cu ratio in serum of patients with sickle cell anemia by total reflection X-ray fluorescence using synchrotron radiation

    Canellas, Catarine G.L.; Leitao, Roberta G.; Lopes, Ricardo T., E-mail: catarine@lin.ufrj.b, E-mail: ricardo@lin.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear. Lab. de Instrumentaco Nuclear; Carvalho, Silvia M.F., E-mail: silvia@hemorio.rj.gov.b [State Institute of Hematology Arthur de Siqueira Cavalcanti (HEMORIO), Rio de Janeiro, RJ (Brazil); Bellido, Alfredo Victor B., E-mail: alfredo@ien.gov.b [Federal Fluminense University (UFF), Niteroi, RJ (Brazil). Chemistry Inst.; Anjos, Marcelino J., E-mail: marcelin@lin.ufrj.b [State University of Rio de Janeiro (UERJ), RJ (Brazil). Physics Inst.

    2011-07-01

    Sickle cell anemia (SCA) is a blood disorder that affects hemoglobin, the protein found in red blood cells that help carry oxygen throughout the body. In this work we have analyzed serum samples from patients with SCA by using total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). The SRTXRF measurements were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo using a polychromatic beam. We have studied forty-three patients aged 18-50 years old, suffering from SCA and Sixty healthy volunteers aged 18-60 years old. It was possible to determine the concentrations of the following elements: P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. Student's t-test was applied in order to check whether the two populations (CG x SCA) had the same mean values. It was observed that elemental concentration of P, Cl, K, Fe, Cu, Zn and Br differed significantly ({alpha} = 0.05) between groups of healthy subjects and SCA. The concentrations of K, Fe and Cu in the serum samples of patients with SCA were larger 15%, 120 % and 20 %, respectively, when compared with the CG. On the other hand, the concentrations of P (-20 %), Cl (-6 %), Zn (-25 %) and Br (-22 %) were smaller than the values determined for the control group. The serum level Cu/Zn ratio was significantly higher (60%) in the serum samples of patients with SCA group than the CG. So, the Cu/Zn ratio can be used as an adjuvant index in enhancement for diagnosis of SCA. There are evidences of an association among Fe, Cu, Zn and Cu/Zn in the SCA pathogenesis process. (author)

  1. Evaluation of Fe and Zn/Cu ratio in serum of patients with sickle cell anemia by total reflection X-ray fluorescence using synchrotron radiation

    Sickle cell anemia (SCA) is a blood disorder that affects hemoglobin, the protein found in red blood cells that help carry oxygen throughout the body. In this work we have analyzed serum samples from patients with SCA by using total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). The SRTXRF measurements were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo using a polychromatic beam. We have studied forty-three patients aged 18-50 years old, suffering from SCA and Sixty healthy volunteers aged 18-60 years old. It was possible to determine the concentrations of the following elements: P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. Student's t-test was applied in order to check whether the two populations (CG x SCA) had the same mean values. It was observed that elemental concentration of P, Cl, K, Fe, Cu, Zn and Br differed significantly (α = 0.05) between groups of healthy subjects and SCA. The concentrations of K, Fe and Cu in the serum samples of patients with SCA were larger 15%, 120 % and 20 %, respectively, when compared with the CG. On the other hand, the concentrations of P (-20 %), Cl (-6 %), Zn (-25 %) and Br (-22 %) were smaller than the values determined for the control group. The serum level Cu/Zn ratio was significantly higher (60%) in the serum samples of patients with SCA group than the CG. So, the Cu/Zn ratio can be used as an adjuvant index in enhancement for diagnosis of SCA. There are evidences of an association among Fe, Cu, Zn and Cu/Zn in the SCA pathogenesis process. (author)

  2. Radiation Therapy

    ... goal of causing less harm to the surrounding healthy tissue. You don't have to worry that you'll glow in the dark after radiation treatment: People who receive external radiation are not radioactive. You' ...

  3. Radiation Protection

    ... Radiation Dose & Risk Low-Activity Radioactive Waste Multi-Agency Radiation Survey and Site Investigation Manual (MARSSIM) Contact Us to ask a question, provide feedback, or report a problem. Main menu Learn the Issues Air Chemicals and ...

  4. Medical radiation

    This leaflet in the At-a-Glance Series describes the medical use of X-rays, how X-rays help in diagnosis, radiation protection of the patient, staff protection, how radioactive materials in nuclear medicine examinations help in diagnosis and the use of radiation in radiotherapy. Magnetic resonance imaging, a diagnostic technique involving no ionizing radiation, is also briefly examined. The role of the NRPB in the medical use of radiation is outlined. (UK)

  5. Ionizing radiation

    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.)

  6. Ionizing radiations

    The purpose of this article is to simplify some of the relevant points of legislation, biological effects and protection for the benefit of the occupational health nurse not familiar with the nuclear industries. The subject is dealt with under the following headings; Understanding atoms. What is meant by ionizing radiation. Types of ionizing radiation. Effects of radiation: long and short term somatic effects, genetic effects. Control of radiation: occupational exposure, women of reproductive age, medical aspects, principles of control. The occupational health nurse's role. Emergency arrangements: national arrangements for incidents involving radiation, action to be taken by the nurse. Decontamination procedures: external and internal contamination. (U.K.)

  7. Atoms, Radiation, and Radiation Protection

    Turner, James E

    2007-01-01

    Atoms, Radiation, and Radiation Protection offers professionals and advanced students a comprehensive coverage of the major concepts that underlie the origins and transport of ionizing radiation in matter. Understanding atomic structure and the physical mechanisms of radiation interactions is the foundation on which much of the current practice of radiological health protection is based. The work covers the detection and measurement of radiation and the statistical interpretation of the data. The procedures that are used to protect man and the environment from the potential harmful effects of

  8. Radiation dosimetry and radiation biophysics

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with the design and measurement of physical parameters used in theory or to support biological experiments. The radiation biophysics program tests and uses the theoretical developments for experimental design, and provides information for further theoretical development through experiments on cellular systems

  9. Radiation dosimetry and radiation biophysics

    Radiation dosimetry and radiation biophysics are two closely integrated programs whose joint purpose is to explore the connections between the primary physical events produced by radiation and their biological consequences in cellular systems. The radiation dosimetry program includes the theoretical description of primary events and their connection with the observable biological effects. This program also is concerned with design and measurement of those physical parameters used in the theory or to support biological experiments. The radiation biophysics program tests and makes use of the theoretical developments for experimental design. Also, this program provides information for further theoretical development through experiments on cellular systems

  10. Radiation Chemistry

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  11. Radiation acoustics

    Lyamshev, Leonid M

    2004-01-01

    Radiation acoustics is a developing field lying at the intersection of acoustics, high-energy physics, nuclear physics, and condensed matter physics. Radiation Acoustics is among the first books to address this promising field of study, and the first to collect all of the most significant results achieved since research in this area began in earnest in the 1970s.The book begins by reviewing the data on elementary particles, absorption of penetrating radiation in a substance, and the mechanisms of acoustic radiation excitation. The next seven chapters present a theoretical treatment of thermoradiation sound generation in condensed media under the action of modulated penetrating radiation and radiation pulses. The author explores particular features of the acoustic fields of moving thermoradiation sound sources, sound excitation by single high-energy particles, and the efficiency and optimal conditions of thermoradiation sound generation. Experimental results follow the theoretical discussions, and these clearl...

  12. Radiation injury

    Radiation accidents and incidents continue to be of great interest and concern to the public. Issues such as the threat of nuclear war, the Chernobyl reactor accident, or reports of sporadic incidences of accidental radiation exposure keep this interest up and maintain a high level of fear among the public. In this climate of real concern and radiation phobia, physicians should not only be prepared to answer questions about acute or late effects of ionizing radiation, but also be able to participate in the initial assessment and management of individuals who have been exposed to ionizing radiation or contaminated with radioactive material. Some of the key facts about radiation injury and its medical treatment are discussed by the author

  13. Radiation regulation

    The five main areas of radiation regulation considered are radiation exposure in the mining of uranium and other minerals, exposure in the use of uranium in nuclear reactors, risks in the transport of radioactive materials and hazards associated with the disposal of used materials. In Australia these problems are regulated by mines departments, the Australian Atomic Energy Commission and radiation control branches in state health departments. Each of these instutional areas of regulation is examined

  14. GRAVITATIONAL RADIATION

    SALTIK, Metin; Mustafa KURT; Mehmet KAYMAK

    1996-01-01

    According to classical electromagnetic theory, an accelerated charge or system of charges radiates electromagnetic waves. In a radio transmitter antenna charges are accelerated along the antenna and release electromagnetic waves, which is radiated at the velocity of light in the surrounding medium. All of the radio transmitters work on this principle today. In this study an analogy is established between the principles by which accelerated charge systems markes radiation and the accelerated m...

  15. Hawking radiation

    Parentani, Renaud; Spindel, Philippe

    2011-12-01

    Hawking radiation is the thermal radiation predicted to be spontaneously emitted by black holes. It arises from the steady conversion of quantum vacuum fluctuations into pairs of particles, one of which escaping at infinity while the other is trapped inside the black hole horizon. It is named after the physicist Stephen Hawking who derived its existence in 1974. This radiation reduces the mass of black holes and is therefore also known as black hole evaporation.

  16. Plume radiation

    Dirscherl, R.

    1993-06-01

    The electromagnetic radiation originating from the exhaust plume of tactical missile motors is of outstanding importance for military system designers. Both missile- and countermeasure engineer rely on the knowledge of plume radiation properties, be it for guidance/interference control or for passive detection of adversary missiles. To allow access to plume radiation properties, they are characterized with respect to the radiation producing mechanisms like afterburning, its chemical constituents, and reactions as well as particle radiation. A classification of plume spectral emissivity regions is given due to the constraints imposed by available sensor technology and atmospheric propagation windows. Additionally assessment methods are presented that allow a common and general grouping of rocket motor properties into various categories. These methods describe state of the art experimental evaluation techniques as well as calculation codes that are most commonly used by developers of NATO countries. Dominant aspects influencing plume radiation are discussed and a standardized test technique is proposed for the assessment of plume radiation properties that include prediction procedures. These recommendations on terminology and assessment methods should be common to all employers of plume radiation. Special emphasis is put on the omnipresent need for self-protection by the passive detection of plume radiation in the ultraviolet (UV) and infrared (IR) spectral band.

  17. Radiation medicine

    This booklet has been produced by UKAEA and the Marie Curie Memorial Foundation to give some basic information about what radiation is and how it is used in day to day diagnosis and treatment. It will be of interest to people undergoing treatment, their relatives and friends, and anyone who wants to know more about this important area. After a brief historical introduction the booklet explains what radiation is, the natural and man-made sources of radiation, how it is produced and how X-rays are used in medical diagnosis and treatment. The radiation protection measures taken and safety standards followed are mentioned. (author)

  18. GRAVITATIONAL RADIATION

    Metin SALTIK

    1996-03-01

    Full Text Available According to classical electromagnetic theory, an accelerated charge or system of charges radiates electromagnetic waves. In a radio transmitter antenna charges are accelerated along the antenna and release electromagnetic waves, which is radiated at the velocity of light in the surrounding medium. All of the radio transmitters work on this principle today. In this study an analogy is established between the principles by which accelerated charge systems markes radiation and the accelerated mass system, and the systems cousing gravitational radiation are investigated.

  19. Radiation roulette

    Radiation biologists at the Medical Research Council, now argue that radiation exposure may cause a much wider range of diseases than epidemiological studies currently predict, with effects being felt well below the 1 millisievert a year public safety levels enforce at present. A fourth outcome for ionizing radiation affecting a living cell has recently been identified, whereby DNA damage to cells can only be detected after they have divided several times, so-called radiation-induced genomic instability. Initial results have been confirmed internationally, but interpretations differ, with some scientists dismissing the connection between genomic instability and disease causation. (UK)

  20. Radiation roulette

    Edwards, R.

    1997-10-11

    Radiation biologists at the Medical Research Council, now argue that radiation exposure may cause a much wider range of diseases than epidemiological studies currently predict, with effects being felt well below the 1 millisievert a year public safety levels enforce at present. A fourth outcome for ionizing radiation affecting a living cell has recently been identified, whereby DNA damage to cells can only be detected after they have divided several times, so-called radiation-induced genomic instability. Initial results have been confirmed internationally, but interpretations differ, with some scientists dismissing the connection between genomic instability and disease causation. (UK).

  1. Radiation protection

    A NRPB leaflet in the 'At-a-Glance' series explains in a simple but scientifically accurate way what radiation is, the biological effects and the relative sensitivity of different parts of the human body. The leaflet then discusses radiation protection principles, radiation protection in the UK and finally the effectiveness of this radiation protection as judged by a breakdown of the total dose received by an average person in the UK, a heavy consumer of Cumbrian seafood, an average nuclear industry worker and an average person in Cornwall. (UK)

  2. Radiation hematology

    State-of-the-Art ofl radiation hematology and review of the problems now facing this brauch of radiobiology and nuclear medicine are presented. Distortion of division and maturation of hemopoiesis parent cells is considered as main factor of radiopathology for hematopoetic system. Problems of radiation injury and functional variation of hematopoetic microenvironment cell populations are discussed. 176 figs.; 23 figs.; 18 tabs

  3. Radiation signatures

    A new concept for modelling radiation risk is proposed. This concept is based on the proposal that the spectrum of molecular lesions, which we dub ''the radiation signature'', can be used to identify the quality of the causal radiation. If the proposal concerning radiation signatures can be established then, in principle, both prospective and retrospective risk determination can be assessed on an individual basis. A major goal of biophysical modelling is to relate physical events such as ionization, excitation, etc. to the production of radiation carcinogenesis. A description of the physical events is provided by track structure. The track structure is determined by radiation quality, and it can be considered to be the ''physical signature'' of the radiation. Unfortunately, the uniqueness characteristics of this signature are dissipated in biological systems in ∼10-9s. Nonetheless, it is our contention that this physical disturbance of the biological system eventuates later, at ∼100s, in molecular lesion spectra which also characterize the causal radiation. (author)

  4. Synchrotron radiation

    The paper on Synchrotron Radiation contains the appendix to the Daresbury Annual Report 1987/88. The appendix is mainly devoted to the scientific progress reports on the work at the Synchrotron Radiation Source in 1987/8. The parameters of the Experimental Stations and the index to the Scientific Reports are also included in the appendix. (U.K.)

  5. Radiation oncology

    The Radiation Oncology Division has had as its main objectives both to operate an academic training program and to carry out research on radiation therapy of cancer. Since fiscal year 1975, following a directive from ERDA, increased effort has been given to research. The research activities have been complemented by the training program, which has been oriented toward producing radiation oncologists, giving physicians short-term experience in radiation oncology, and teaching medical students about clinical cancer and its radiation therapy. The purpose of the research effort is to improve present modalities of radiation therapy of cancer. As in previous years, the Division has operated as the Radiation Oncology Program of the Department of Radiological Sciences of the University of Puerto Rico School of Medicine. It has provided radiation oncology support to patients at the University Hospital and to academic programs of the University of Puerto Rico Medical Sciences Campus. The patients, in turn, have provided the clinical basis for the educational and research projects of the Division. Funding has been primarily from PRNC (approx. 40%) and from National Cancer Institute grants channeled through the School of Medicine (approx. 60%). Special inter-institutional relationships with the San Juan Veterans Administration Hospital and the Metropolitan Hospital in San Juan have permitted inclusion of patients from these institutions in the Division's research projects. Medical physics and radiotherapy consultations have been provided to the Radiotherapy Department of the VA Hospital

  6. Concepts of radiation protection

    This seventh chapter presents the concepts and principles of safety and radiation protection, emergency situations; NORM and TENORM; radiation protection care; radiation protection plan; activities of the radiation protection service; practical rules of radiation protection and the radiation symbol

  7. Radiation sickness

    The frequency of radiation sickness in 1,060 patients treated at our Department was 12.8 percent. It was frequent in patients with brain cancer (12 percent), whole spine cancer (47 percent), uterus cancer (28 percent), lung cancer (22 percent) and esophagus cancer (12 percent). Radiation sickness following X-irradiation was studied in its relation to patient's age, size of radiation fields, dosis and white blood cell count. However, we could not find any definite clinical feature relevant to occurrence. There are many theories published concerning the mechanism of radiation sickness. Clinical experiences have shown that radiation sickness cannot be explained by one theory alone but by several theories such as those based on psychology, stress or histamine. (author)

  8. Medical radiation

    Three slide sets which can be used in lectures about radiation protection have been published by NRPB. The slide sets are based on publications in the NRPB ''At-a-Glance'' series of broadsheets, which use illustrations as the main source of information, supported by captions; the series generally avoids the jargon of radiation protection, although each leaflet is based on scientific studies. Slide Set Number 3, ''Medical Radiation'', outlines the production and use of x-rays in diagnosis, the protection of staff and patients, and the use of radioactive materials in diagnosis and radiotherapy. It summarises the use of magnetic resonance imaging. Radiation doses received during various x-ray examinations are compared with radiation doses from nature. (Author)

  9. Radiation carcinogenesis

    Studies on neutron carcinogenesis, time-dose relationships, the role of host factors in radiation carcinogenesis, and the dynamics of the carcinogenic process after exposure to radiation and chemicals are reported. Problems are being pursued with in vivo studies as well as in vitro and in vivo/in vitro approaches. A common theme among all of these studies is the examination of mechanisms and the establishment of general principles which may alow a better understanding of the risks to humans from radiation exposure. Data from all of these studies are also being used to examine more direct methods of extrapolation of animal data to human risks. The program in ultraviolet radiation carcinogenesis (UVR) is concerned with development of model systems, methods and background information necessary for designing quantitative UVR carcinogenesis experiments, the role of interactions of UVR and chemicals, and interactions between ionizing and ultraviolet radiation in skin carcinogenesis

  10. Radiation detector

    Fultz, Brent T.

    1983-01-01

    Apparatus is provided for detecting radiation such as gamma rays and X-rays generated in backscatter Mossbauer effect spectroscopy and X-ray spectrometry, which has a large "window" for detecting radiation emanating over a wide solid angle from a specimen and which generates substantially the same output pulse height for monoenergetic radiation that passes through any portion of the detection chamber. The apparatus includes a substantially toroidal chamber with conductive walls forming a cathode, and a wire anode extending in a circle within the chamber with the anode lying closer to the inner side of the toroid which has the least diameter than to the outer side. The placement of the anode produces an electric field, in a region close to the anode, which has substantially the same gradient in all directions extending radially from the anode, so that the number of avalanche electrons generated by ionizing radiation is independent of the path of the radiation through the chamber.

  11. Radiation accidents

    Radiation accidents may be viewed as unusual exposure event which provide possible high exposure to a few people and, in the case of nuclear plants events, low exposure to large population. A number of radiation accidents have occurred over the past 50 years, involving radiation machines, radioactive materials and uncontrolled nuclear reactors. These accidents have resulted in number of people have been exposed to a range of internal and external radiation doses and those involving radioactive materials have involved multiple routs of exposure. Some of the more important accidents involving significant radiation doses or releases of radioactive materials, including any known health effects involves in it. An analysis of the common characteristics of accidents is useful resolving overarching issues, as has been done following nuclear power, industrial radiography and medical accidents. Success in avoiding accidents and responding when they do occur requires planning in order to have adequately trained and prepared health physics organization; well defined and developed instrument program; close cooperation among radiation protection experts, local and state authorities. Focus is given to the successful avoidance of accidents and response in the events they do occur. Palomares, spain in late 1960, Goiania, Brazil in 1987, Thule, Greenland in 1968, Rocky flats, Colorado in 1957 and 1969, Three mile island, Pennsylvania in 1979, Chernobyl Ukraine in april 1986, Kyshtym, former Soviet Union in 1957, Windscale, UK in Oct. 1957 Tomsk, Russian Federation in 1993, and many others are the important examples of major radiation accidents. (author)

  12. Radiation Hydrodynamics

    Castor, J I

    2003-10-16

    The discipline of radiation hydrodynamics is the branch of hydrodynamics in which the moving fluid absorbs and emits electromagnetic radiation, and in so doing modifies its dynamical behavior. That is, the net gain or loss of energy by parcels of the fluid material through absorption or emission of radiation are sufficient to change the pressure of the material, and therefore change its motion; alternatively, the net momentum exchange between radiation and matter may alter the motion of the matter directly. Ignoring the radiation contributions to energy and momentum will give a wrong prediction of the hydrodynamic motion when the correct description is radiation hydrodynamics. Of course, there are circumstances when a large quantity of radiation is present, yet can be ignored without causing the model to be in error. This happens when radiation from an exterior source streams through the problem, but the latter is so transparent that the energy and momentum coupling is negligible. Everything we say about radiation hydrodynamics applies equally well to neutrinos and photons (apart from the Einstein relations, specific to bosons), but in almost every area of astrophysics neutrino hydrodynamics is ignored, simply because the systems are exceedingly transparent to neutrinos, even though the energy flux in neutrinos may be substantial. Another place where we can do ''radiation hydrodynamics'' without using any sophisticated theory is deep within stars or other bodies, where the material is so opaque to the radiation that the mean free path of photons is entirely negligible compared with the size of the system, the distance over which any fluid quantity varies, and so on. In this case we can suppose that the radiation is in equilibrium with the matter locally, and its energy, pressure and momentum can be lumped in with those of the rest of the fluid. That is, it is no more necessary to distinguish photons from atoms, nuclei and electrons, than it is

  13. Radiation sterilisation

    The South African Atomic Energy Board operates an irradiation plant for the sterilisation of pharmaceutical products at Pelindaba. The advantages of this plant are discussed as well as the position radiation processing currently enjoys in industry

  14. Radiation sensors

    Radiation detectors, suitable for use in industrial environments, eg coal mines are claimed. At least two scintillation crystals are mounted on a resilient support material, preferably silicone rubber. The sensors are both robust and compact. (U.K.)

  15. Radiation Therapy

    ... therapy. At this time, you will have a physical exam , talk about your medical history , and maybe have imaging tests . Your doctor or nurse will discuss external beam radiation therapy, its benefits and side effects, and ways you can care ...

  16. Synchrotron radiation

    A detailed account of the research work associated with the Synchrotron Radiation Source at Daresbury Laboratory, United Kingdom, in 1984/85, is presented in the Appendix to the Laboratory's Annual Report. (U.K.)

  17. Radiation curing

    In the beginning of the seventies the two types of radiation sources applied in industrial processes, electron radiation and UV, had been given rather optimistic forecasts. While UV could succeed in the field of panel and film coating, electron radiation curing seems to gain success in quite new fields of manufacturing. The listing of the suggested applications of radiation curing and a comparison of both advantages and disadvantages of this technology are followed by a number of case studies emphasizing the features of these processes and giving some examplary calculations. The data used for the calculations should provide an easy calculation of individual manufacturing costs if special production parameters, investment or energy costs are employed. (Author)

  18. Radiation Entomology

    A. Nagaratnam

    2000-01-01

    The article reviews the use of radiation and radioisotopes in entomology with special reference to the use of radiotracers in entomological studies and the use of sterile insect techniques in the control of insect pests. It also presents' a profile of Shri Koshy and his contributions to defence entomology, including design of an efficient device for the rearing of cockroaches, evaluation of different repellents against leeches, laboratory and pilot field studies on the use of radiation-steril...

  19. Radiation Protection

    Major achievements of SCK-CEN's Radiation Protection Department in 2000 are described. The main areas for R and D of the department remain neutron dosimetry and neutron activation analysis, safeguards information handling and non-destructive assay techniques. Further activities include low-level radioactivity measurements in environmental and biological samples and radiation protection research. Finally, achievements in decision strategy research and social sciences in nuclear research are reported

  20. Electromagnetic Radiation

    Andrews, D L

    2010-01-01

    Electromagnetic radiation, commonly referred to as light, underpins all spectroscopic techniques, ranging from the highly energetic gamma rays, through x-rays, ultraviolet, visible, infrared, microwaves to the low-energy radio waves. The principles of wave- and particle-like behaviour determine the nature of the radiation and its interaction with matter, whether in the form of subatomic, atomic, molecular or macromolecular structures. © 1999 Elsevier Ltd All rights reserved.

  1. Synchrotron radiation

    A report is given on the work involving the Synchrotron Radiation Division of the Daresbury Laboratory during the period January 1981 - March 1982. Development of the source, beamlines and experimental stations is described. Progress reports from individual investigators are presented which reveal the general diversity and interdisciplinary nature of the research which benefits from access to synchrotron radiation and the associated facilities. Information is given on the organisation of the Division and publications written by the staff are listed. (U.K.)

  2. Radiation emergencies

    Elaborate precautions are taken in the design, construction and operation of nuclear installations. Even then, there always remains the possibility, however small, of accidents. A radiation emergency can be defined as any abnormal situation following an incident/accident which may result in either unusually large radiation fields in any plant/area or large release of air or liquid borne radioactivity leading to widespread contamination of areas

  3. Synchrotron radiation

    The paper on synchrotron radiation is the appendix to the Daresbury (United Kingdom) annual report, 1985/86. The bulk of the volume is made up of the progress reports for the work carried out during the year under review using the Synchrotron Radiation Source (SRS) at Daresbury. The Appendix also contains: the scientific programmes at the the SRS, progress on beamlines, instrumentation and computing developments, and activities connected with accelerator development. (U.K.)

  4. Radiation Transport

    Urbatsch, Todd James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  5. Radiation dosimeters

    A radiation dosimeter is a device, instrument or system that measures or evaluates, either directly or indirectly, the quantities exposure, kerma, absorbed dose or equivalent dose, or their time derivatives (rates), or related quantities of ionizing radiation. A dosimeter along with its reader is referred to as a dosimetry system. Measurement of a dosimetric quantity is the process of finding the value of the quantity experimentally using dosimetry systems. The result of a measurement is the value of a dosimetric quantity expressed as the product of a numerical value and an appropriate unit. To function as a radiation dosimeter, the dosimeter must possess at least one physical property that is a function of the measured dosimetric quantity and that can be used for radiation dosimetry with proper calibration. In order to be useful, radiation dosimeters must exhibit several desirable characteristics. For example, in radiotherapy exact knowledge of both the absorbed dose to water at a specified point and its spatial distribution are of importance, as well as the possibility of deriving the dose to an organ of interest in the patient. In this context, the desirable dosimeter properties will be characterized by accuracy and precision, linearity, dose or dose rate dependence, energy response, directional dependence and spatial resolution. Obviously, not all dosimeters can satisfy all characteristics. The choice of a radiation dosimeter and its reader must therefore be made judiciously, taking into account the requirements of the measurement situation

  6. Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

    Chu, Sung Sil; Suh, Chang Ok; Kim, Gwi Eon [Yonsei Univ., Seoul (Korea, Republic of)

    2002-03-15

    High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of As Low As Reasonably Achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons . This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients are treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Polo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions 30cm x 30cm x 20cm. The anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is

  7. Shielding for Critical Organs and Radiation Exposure Dose Distribution in Patients with High Energy Radiotherapy

    High energy photon beams from medical linear accelerators produce large scattered radiation by various components of the treatment head, collimator and walls or objects in the treatment room including the patient. These scattered radiation do not provide therapeutic dose and are considered a hazard from the radiation safety perspective. Scattered dose of therapeutic high energy radiation beams are contributed significant unwanted dose to the patient. ICRP take the position that a dose of 500mGy may cause abortion at any stage of pregnancy and that radiation detriment to the fetus includes risk of mental retardation with a possible threshold in the dose response relationship around 100 mGy for the gestational period. The ICRP principle of As Low As Reasonably Achievable (ALARA) was recommended for protection of occupation upon the linear no-threshold dose response hypothesis for cancer induction. We suggest this ALARA principle be applied to the fetus and testicle in therapeutic treatment. Radiation dose outside a photon treatment filed is mostly due to scattered photons . This scattered dose is a function of the distance from the beam edge, treatment geometry, primary photon energy, and depth in the patient. The need for effective shielding of the fetus and testicle is reinforced when young patients are treated with external beam radiation therapy and then shielding designed to reduce the scattered photon dose to normal organs have to considered. Irradiation was performed in phantom using high energy photon beams produced by a Varian 2100C/D medical linear accelerator (Varian Oncology Systems, Polo Alto, CA) located at the Yonsei Cancer Center. The composite phantom used was comprised of a commercially available anthropomorphic Rando phantom (Phantom Laboratory Inc., Salem, YN) and a rectangular solid polystyrene phantom of dimensions 30cm x 30cm x 20cm. The anthropomorphic Rando phantom represents an average man made from tissue equivalent materials that is

  8. Radiation enteritis and radiation scoliosis

    Shah, M.; Eng, K.; Engler, G.L.

    1980-09-01

    Any patient with radiation scoliosis should be suspected of having a visceral lesion as well. Chronic radiation enteritis may be manifested by intestinal obstruction, fistulas, perforation, and hemorrhage. Intestinal obstruction is the most common complication, and must be differentiated from postoperative cast or from spinal-traction syndrome. Obstruction that does not respond promptly to conservative measures must be treated surgically. Irradiated bowel is ischemic, and necrosis with spontaneous perforation can only be avoided with early diagnosis and surgical intervention.

  9. Radiation enteritis and radiation scoliosis

    Any patient with radiation scoliosis should be suspected of having a visceral lesion as well. Chronic radiation enteritis may be manifested by intestinal obstruction, fistulas, perforation, and hemorrhage. Intestinal obstruction is the most common complication, and must be differentiated from postoperative cast or from spinal-traction syndrome. Obstruction that does not respond promptly to conservative measures must be treated surgically. Irradiated bowel is ischemic, and necrosis with spontaneous perforation can only be avoided with early diagnosis and surgical intervention

  10. Radiation cataract

    Until very recently, ocular exposure guidelines were based on the assumption that radiation cataract is a deterministic event requiring threshold doses generally greater than 2 Gy. This view was, in part, based on older studies which generally had short follow-up periods, failed to take into account increasing latency as dose decreased, had relatively few subjects with doses below a few Gy, and were not designed to detect early lens changes. Newer findings, including those in populations exposed to much lower radiation doses and in subjects as diverse as astronauts, medical workers, atomic bomb survivors, accidentally exposed individuals, and those undergoing diagnostic or radiotherapeutic procedures, strongly suggest dose-related lens opacification at significantly lower doses. These observations resulted in a recent re-evaluation of current lens occupational exposure guidelines, and a proposed lowering of the presumptive radiation cataract threshold to 0.5 Gy/year and the occupational lens exposure limit to 20 mSv/year, regardless of whether received as an acute, protracted, or chronic exposure. Experimental animal studies support these conclusions and suggest a role for genotoxicity in the development of radiation cataract. Recent findings of a low or even zero threshold for radiation-induced lens opacification are likely to influence current research efforts and directions concerning the cellular and molecular mechanisms underlying this pathology. Furthermore, new guidelines are likely to have significant implications for occupational and/or accidental exposure, and the need for occupational eye protection (e.g. in fields such as interventional medicine).

  11. Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control. Invited papers and discussions from a conference in Seville, Spain, 17-21 November 1997

    Radiological protection is concerned with the limitation of the consequential risks from exposure to ionising radiation. In recent years, there has been much debate about the validity of one of the fundamental bases of the present system for the limitation of these risks, i.e., at the low dose rates with which we are usually concerned in routine activities, the incremental increase in the risk of stochastic effects (primarily cancer) is linearly related to the additional radiation dose above that from the natural background. This is the linear, no-threshold (LNT) dose-response paradigm adopted by the ICRP in developing its recommendations. Re-analysis and interpretation of existing data, and new data on effects that may (or may not) be of relevance to cancer induction, have led to proposals for contrary supralinear, threshold and hormetic (beneficial) response relationships at low doses. It was the purpose of this conference to provide a forum to examine the latest information and debate the issues. A detailed meeting report has been given in an earlier issue of this journal (Wakeford R and Tawn E J 1998 J. Radiol. Prot. 18 52-6), and the majority of the short papers presented at the conference were issued, at that time, as an IAEA Technical Document (IAEA TECDOC-976, available free of charge from the IAEA in Vienna). This publication provides the keynote papers, summaries of the discussions and the session chairmen's summaries for each of the set of ten fora, a special session and a final round-table discussion that constituted the main body of the conference. Also included are the papers presented in two introductory background sessions that provided some context for the conference. All of the keynote papers provide, as might be expected, useful summaries of the state of the art in the respective fields. This is particularly so for the fora 8-10 that introduced the discussion of control measures and criteria for intervention, in which circumstance there is, at

  12. Dose–responses from multi-model inference for the non-cancer disease mortality of atomic bomb survivors

    Schöllnberger, H.; Kaiser, J. C.; Jacob, P.; Walsh, L

    2012-01-01

    The non-cancer mortality data for cerebrovascular disease (CVD) and cardiovascular diseases from Report 13 on the atomic bomb survivors published by the Radiation Effects Research Foundation were analysed to investigate the dose–response for the influence of radiation on these detrimental health effects. Various parametric and categorical models (such as linear-no-threshold (LNT) and a number of threshold and step models) were analysed with a statistical selection protocol that rated the mode...

  13. Atomic Bomb Health Benefits

    Luckey, T.D.

    2008-01-01

    Media reports of deaths and devastation produced by atomic bombs convinced people around the world that all ionizing radiation is harmful. This concentrated attention on fear of miniscule doses of radiation. Soon the linear no threshold (LNT) paradigm was converted into laws. Scientifically valid information about the health benefits from low dose irradiation was ignored. Here are studies which show increased health in Japanese survivors of atomic bombs. Parameters include decreased mutation,...

  14. Radiation gauge

    Fuji Electric has developed a pipe wall thinning detection device, which operates based on radiation gauge technology, for use in nuclear power plants and thermoelectric power plants. The radiation from the pipe wall thinning detection device, which can be used even during the plant operation, can penetrate heat insulation material. The device consists of detector and radiation source, and can detect the thickness of pipes (less than 500 mm in external diameter and less than 50 mm in thickness) with 2% reproducibility (with a measurement time of several minutes), based on the attenuation rate. Operation is easy and efficient since there is no need to remove the heat insulation and it is easy to mount the device, thus enabling more effective detection. (author)

  15. Radiation myelopathy

    Sutherland, I.A.; Myers, S.J.

    1976-02-01

    Myelopathy secondary to radiation is a relatively uncommon entity which was reported initially in 1941 by Ahlbom. From a total of 65 patients who were seen in our spinal injury clinic during the past four years, three patients have received a diagnosis of radiation myelopathy. This is 4.6 percent of the total number. The case histories of two patients with radiation myelopathy are presented. The clinical and pathologic features are discussed. Since the three patients with this diagnosis whose cases are followed in the clinic are still alive, the second case that is reported is taken from the files of the pathology department so that autopsy and histologic data also can be presented.

  16. Radiation myelopathy

    Myelopathy secondary to radiation is a relatively uncommon entity which was reported initially in 1941 by Ahlbom. From a total of 65 patients who were seen in our spinal injury clinic during the past four years, three patients have received a diagnosis of radiation myelopathy. This is 4.6 percent of the total number. The case histories of two patients with radiation myelopathy are presented. The clinical and pathologic features are discussed. Since the three patients with this diagnosis whose cases are followed in the clinic are still alive, the second case that is reported is taken from the files of the pathology department so that autopsy and histologic data also can be presented

  17. Synchrotron radiation

    Synchrotron radiation has had a revolutionary effect on a broad range of scientific studies, from physics, chemistry and metallurgy to biology, medicine and geoscience. The situation during the last decade has been one of very rapid growth, there is a great vitality to the field and a capability has been given to a very broad range of scientific disciplines which was undreamt of just a decade or so ago. In this paper, the authors discuss some of the properties of synchrotron radiation that makes it so interesting and something of the sources in existence today including the National Synchrotron Light Source (NSLS). The NSLS is one of the new facilities built specifically for synchrotron radiation research and the model that was developed there for involvement of the scientific community is a good one which provides some good lessons for these facilities and others

  18. Synchrotron radiation

    Synchrotron radiation (SR) from the bending magnet of a circular electron (positron) accelerator is a brilliant source in the vacuum ultraviolet, soft- and hard-x ray regions. First the characteristics of the bending SR are delete discussed. Though the brilliance of SR was improved dramatically in the last decade, neither bending, wiggler SR nor undulator SR is coherent. Coherent far infrared radiation in the mm wavelength region has recently been observed from a short electron bunch (∼ 2.5 mm long) in a bending magnet connected to a linac at Tohoku University. Coherent radiation due to higher harmonics generation by laser excitation of electron bunches in an undulator is then described. Finally a free electron laser (FEL) using optical klystron in a storage ring is reviewed. (author)

  19. Radiation risks

    This report contains an evaluation of data available about the deleterious effects of exposure of people to ionising radiation, assuming that the total exposure is low (low dose) or that exposure to dose takes place gradually (low dose rate). It is a revision of the 1985 Health Council report on 'The scientific foundations for radiation protection policy based on the UNSCEAR-77, -82, and BEIR reports'. The report is also meant to be a reply to a request for advice made by the Minister of Welfare, Public Health and Culture in 1989. Scientific opinion on induction of cancer by radiation has clearly changed since 1988. This is a consequence of new publications of epidemiological studies among survivors of the atomic explosions of Hiroshima and Nagasaki. The Committee that has produced the present report has paid much attention to this development. Besides, in the request for advice just mentioned it is asked whether the margins of uncertainty which complicated the quantitative assessment of the radiation risk can be reduced. Consequently the Committee has dealt extensively with the potential errors and uncertainties in available data. Especially these 2 elements - a careful consideration of a recent shift in scientific opinion and a constant attention for the magnitude of potential uncertainties - have had a predominant influence on the content and design of this report. The Committee has tried to answer as fully as possible the complex question how to transform results of scientific research into a well-organised data set on which the government can base its radiation protection policy. The Committee had also compared its evaluation to the recent recommendations of the International Commission on Radiological Protection (ICRP) and the points of view of the Dutch policy directive 'Dealing with radiation risks'. (author). 111 refs.; 12 tabs

  20. Radiation control

    This paper describes on how the condition of radiation level in the ring (storage ring) experimentation room changes corresponding to the operating stage of SOR-ring (synchrotron radiation storage ring), and does not describe on the present radiation control in the SOR facility. The operating stage of SOR is divided into the following five: (1) 307 MeV electron injection, (2) 307 MeV electron storage (used for SOR experiments), (3) energy increase from 307 to 380 MeV, (4) 380 MeV electron storage, (5) re-injection and completion of operation. Gamma and X ray levels are shown when electron beam is injected from the electron synchrotron to the SOR-ring. Two main causes of the high level are reported. Spatial dose rate in storing 307 MeV electrons in also illustrated. This is sufficiently lower than that at electron incidence. The measurement of radiation level at the time of energy increase from 307 to 380 MeV has just started. Since the radiation level in 380 MeV storage, measured at the points about 20 cm apart from the electron orbit, showed several mR/h, the level seems to be negligible at the points where experiments are carried out, 1 m away from the measurement points. The radiation level in electron reinjection and completion of operation may be large during a short period (a few Roentgen) like the time of energy increase. Therefore, the beam shall be re-injected or decreased after confirming that all experimenters have retreated into the predetermined place. (Wakatsuki, Y.)

  1. Radiation Entomology

    A. Nagaratnam

    2000-10-01

    Full Text Available The article reviews the use of radiation and radioisotopes in entomology with special reference to the use of radiotracers in entomological studies and the use of sterile insect techniques in the control of insect pests. It also presents' a profile of Shri Koshy and his contributions to defence entomology, including design of an efficient device for the rearing of cockroaches, evaluation of different repellents against leeches, laboratory and pilot field studies on the use of radiation-sterilised males for the control of the mosquito Culex fatigans.

  2. Radiation toxicology

    Extensive studies on both human and experimental animal populations have provided information that allow radiation protection standards to be set with greater confidence than for most if not all other carcinogenic agents. Furthermore, both international and national advisory bodies are continually updating the risk estimates and the standards as new information is available. However, it is clear that models are needed that take into account the multistage nature of carcinogenesis. Studies in both ionizing and ultraviolet radiation carcinogenesis are more valuable to the general problem of elucidating the mechanisms involved in cancer than is indicated by the amount of work or support for this field of research

  3. Radiation dermatitis

    Even in this era of modern radiotherapy, injuries associated with the medical and industrial use of radiation devices will continue to pose a difficult problem for the reconstructive surgeon. It must be borne in mind that the single most serious hazard to surgery in irradiated tissue is the lodgement of bacteria in tissue rendered avascular by the radiation and the secondary necrosis from the infection itself. The basic principles of wound management must be augmented by thorough knowledge of the use of well-vascularized muscle and musculocutaneous flap to provide adequate, blood-rich, soft-tissue coverage

  4. Radiation toxicology

    The extensive studies on both human and experimental animal populations have provided information that allows radiation protection standards to be set with greater confidence than for most if not all other carcinogenic agents. Furthermore, both international and national advisory bodies are continually updating the risk estimates and the standards as new information is available. However, it is clear that we need models that take into account the multistage nature of carcinogenesis. Studies in both ionizing and ultraviolet radiation carcinogenesis are more valuable to the general problem of elucidating the mechanisms involved in cancer than is indicated by the amount of work or support for this field of research

  5. Radiation Technology

    The conference was organized to evaluate the application directions of radiation technology in Vietnam and to utilize the Irradiation Centre in Hanoi with the Co-60 source of 110 kCi. The investigation and study of technico-economic feasibility for technology development to various items of food and non-food objects was reported. (N.H.A)

  6. Radiation dosimetry

    Film is one of the most simple ways to detect radiation although for film as dosimeters a careful attention is required in many aspects, such as emulsion characteristics, film response capacity processing techniques and interpretation of the exposition. Surpassing these factors the film dosimeter is the most reliable

  7. Radiation dosage

    Radiation dosage at Bikini Atoll is the result of current soil contamination, a relic of the nuclear weapons testing program of some 30 years ago. The principal contaminants today and some of their physical properties are listed: cesium-137, strontium-90, plutonium -239, 240 and americium-241. Cobalt-60 contributes less than 1 to the dose and is not considered significant. A resident of the atoll would accumulate radiation dose (rem) in two ways -- by exposure to radiation emanating from the ground and vegetation, and by exposure to radiation released in the spontaneous decay of radionuclides that have entered his body during the ingestion of locally grown foods. The latter process would account for some 90% of the dose; cesium-137 would be responsible for 0 90% of it. Since BARC's method of estimating dosage differs in some respects from that employed by the Lawrence Livermore National Laboratory (LLNL), (Ref.1, LLNL 1982) we are presenting our method in detail. The differences have two sources. First, the numbers used by BARC for the daily ingestion of radionuclides via the diet are higher than LLNL's. Second, BARC's calculation of dose from radionuclide intake utilizes the ICRP system. The net result is that BARC doses are consistently higher than LLNL doses, and in this respect are more conservative

  8. Radiation effects and radiation risks

    The book presents the facts and the principles of assessment and evaluation of biological radiation effects in general and also with particular reference to the reactor accident of Chernobyl, reviewing the consequences and the environmental situation on the basis of current national and international literature, including research work by the authors. The material compiled in this book is intended especially for physicians, but will also prove useful for persons working in the public health services, in administration, or other services taking care of people. The authors tried to find an easily comprehensible way of presenting and explaining the very complex processes and mechanisms of biological radiation effects and carcinogenesis, displaying the physical primary processes and the mechanisms of the molecular radiation effects up to the effects of low-level radiation, and present results of comparative epidemiologic studies. This section has been given considerable space, in proportion to its significance. It also contains literature references for further reading, offering more insight and knowledge of aspects of special subject fields. The authors also present less known results and data and discuss them against the background of well-known research results and approaches. Apart from the purpose of presenting comprehensive information, the authors intend to give an impact for further thinking about the problems, and helpful tools for independent decisions and action on the basis of improved insight and assessment, and in this context particularly point to the problems induced by the Chernobyl reactor accident. (orig./MG) With 8 maps in appendix

  9. Radiation teratogenesis

    Although small head size and metal retardation (MR) were first recognized as teratogenic effects of ionizing radiation in the 1920s, new information continues to emerge about these effects. Early studies of the Japanese atomic-bomb survivors showed that small head size was induced by doses as low as 10-19 rad in air. The next steps are to relate the effects to the new (1985) dosimetry, and to seek lesser effects on the brain by new tests to detect such clinical deficits as inability to sequence ideas, comprehend complex syntax, or pay attention. Although an array of congenital anomalies has been induced by prenatal radiation exposures of animals, only small head size and MR have occured excessively in the human

  10. Radiation protection

    Radioactive Shipping Service

    2005-01-01

    The section of the radiation protection group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tél. 73171

  11. Radiation protection

    2005-01-01

    The section of the Radiation Protection Group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tél. 73171

  12. Radiation protection

    2005-01-01

    The section of the Radiation Protection Group in charge of shipping radioactive material would like to remind users that all radioactive material leaving CERN must be checked for radioactivity and must be shipped according to the procedure given at http://cern.ch/service-rp-shipping Do not hesitate to contact us for any question or control. Radioactive Shipping Service: service-rp-shipping@cern.ch Tel. 73171

  13. Radiation detector

    The scintillation crystal is suitable for use in computer tomography. It is in the form of a wedge, at whose wide end there is a photo-electric diode. The X-rays or γ-radiation impinges on one of the wedge surfaces. The other wedge surfaces, except the wide end, are provided with light scattering coatings, so that all the light produced is directed to the photo-electric diode. (DG)

  14. Radiation pager

    Methods of interdicting nuclear materials to date have favored the use of large portal detectors at choke points, or hand carried instruments used by trained personnel for conducting spot searches. Although these methods are effective in some instances, it is often impractical to insert choke points at busy traffic areas, and it is not cost effective to maintain a force of skilled operators whose focus is nuclear interdiction. Recent technology developments are causing profound changes in the philosophy and methods employed for interdicting nuclear materials. Breakthrough advances in the miniaturization of detectors and low power electronics have made possible a new class of small gamma-ray radiation detectors, roughly the size of a message pager, with unprecedented sensitivity for their size. These instruments, named Radiation PagersTM, are ideally suited for use by untrained individual law enforcement personnel and emergency responders in the course of their regular duties. New tactics that utilize a radiation detector worn by every officer are creating a moving curtain of detection with a significantly higher likelihood of locating illicit nuclear contraband. These individual detectors also provide each officer with a high level of confidence that they are not being unknowingly irradiated in the course of their work. (author)

  15. Risk Factors: Radiation

    Radiation of certain wavelengths, called ionizing radiation, has enough energy to damage DNA and cause cancer. Ionizing radiation includes radon, x-rays, gamma rays, and other forms of high-energy radiation.

  16. Radiation preservation of maize

    Radiation preservation of maize was carried out. Radiation doses and sources, shielding materials, packaging materials, chemical radiation effects, biological radiation effects, were discussed. Experimental methods, samples and accessories were also presented. (SMN)

  17. Radiation protection

    Three main pillars underpin the IAEA's mission: Safety and Security - The IAEA helps countries to upgrade their infrastructure for nuclear and radiation safety and security, and to prepare for and respond to emergencies. Work is keyed to international conventions, the development of international standards and the application of these standards. The aim is to protect people and the environment from the harmful effects of exposure to ionizing radiation. Science and Technology - The IAEA is the world's focal point for mobilizing peaceful applications of nuclear science and technology for critical needs in developing countries. The work contributes to alleviating poverty, combating disease and pollution of the environment and to other goals of sustainable development. Safeguards and Verification - The IAEA is the nuclear inspectorate, with more than four decades of verification experience. Inspectors work to verify that nuclear material and activities are not diverted towards military purposes. Quantities and Units: Dose equivalent is the product of absorbed dose of radiation and quality factor (Q). For absorbed dose in rads, dose equivalent is in rems. If absorbed dose is in gray, the dose equivalent is in sievert. Quality factor is defined without reference to any particular biological end point. Quality factors are recommended by committees such as the International Commission on Radiological Protection (ICRP) or the National Council on Radiation Protection and Measurements (NCRP), based on experimental RBE values but with some judgment exercised. Effective Dose Equivalent: It is the sum of the weighted dose equivalents for all irradiated tissues, in which the weighting factors represent the different risks of each tissue to mortality from cancer and hereditary effects. Committed dose equivalent: It is the integral over 50 years of dose equivalent following the intake of a radionuclide. Collective effective dose equivalent: It is a quantity for a population and is

  18. Perspective of radiation processing

    The area of the applications of radiation techniques is very wide. This paper only relates to the applications of radiation techniques in industries including radiation chemical industry, radiation processing of foods and environmental protection by radiation, but the nuclear instruments and the instrumentations of radiation are out-side of our study. (author)

  19. Radiation hormesis

    The author defines hormesis as the stimulus given to any organism by non-toxic concentrations of toxic substances and gives a few examples of the experimental evidence for the existence of radiation hormesis. The most probable explanation for its working lies not in the education of the nuclear repair system but in the education of the immune system, which is very complex and is capable of learning to deal with a variety of threats to living cells. The effects of both high LET and low LET particles are considered. (author)

  20. Radiation nephropathy

    Reports of damage to the normal kidney of children who had undergone radiotherapy, together with the administration of antitumour drugs, for Wilms' tumour are briefly reviewed. Acute radiation nephritis has been recorded after doses as low as 1500 rad. The number of children with Wilms' tumour surviving after treatment is increasing rapidly, and more intensive treatment regimens (radiotherapy and cytotoxic drugs) are now being used in young children with malignant tumours. The effects of this combined treatment on normal tissues should be recognised if excessive morbidity from treatment is to be avoided. (U.K.)

  1. Radiation sensitizers

    The following classes of radiosensitizers are discussed: electron affinic compounds, pyrimidine analogs, and antibiotics. Metronidazole and nitroimidazole are discussed as examples of electron-affinic compounds. Studies on the enhancement ratio for sensitization of x-irradiated hamster cells showed that these drugs sensitize at concentrations much lower than the toxic concentrations. Criteria for a clinically useful hypoxic cell sensitizer are listed and mechanisms of electron-affinic sensitizers are discussed. The radiosensitizing effects of the pyrimidine analogs, BUDR, BCDR, IUDR, CUDR, and FUDR, are examined and the enhancement of radiation effects by the chemotherapeutic agent, 5-fluorouracil, is discussed. Other agents discussed are methotrexate, actinomycin D, bleomycin, and adriamycin

  2. Synchrotron radiation

    This report details the activities in synchrotron radiation and related areas at Daresbury Laboratory during 1989/90. The number and scope of the scientific reports submitted by external users and in-house staff is a reflection of the large amount of scheduled beamtime and high operating efficiency achieved at the Synchrotron Radiation Source (SRS) during the past year. Over 4000 hours of user beam were available, equivalent to about 80% of the total scheduled time. Many of the reports collected here illustrate the increasing technical complexity of the experiments now being carried out at Daresbury. Provision of the appropriate technical and scientific infrastructure and support is a continuing challenge. The development of the Materials Science Laboratory together with the existing Biological Support Laboratory will extend the range of experiments which can be carried out on the SRS. This will particularly facilitate work in which the sample must be prepared or characterised immediately before or during an experiment. The year 1989/90 has also seen a substantial upgrade of several stations, especially in the area of x-ray optics. Many of the advantages of the High Brightness Lattice can only be exploited effectively with the use of focusing optics. As the performance of these stations improves, the range of experiments which are feasible on the SRS will be extended significantly. (author)

  3. Ultraviolet radiation

    Ultraviolet radiation (UVR) from the sun or artificial sources is reflected or transmitted at the surface of the skin, about 5% of normally incident rays being directly reflected. The transmitted fraction is scattered, photochemically absorbed or dissipated as heat within the skin, or passes from it to contribute to the variable total amount of reflected and transmitted radiation. The UVR absorbers in skin are not definitely known, but DNA is a definite target and probably lipoprotein membranes, RNA, proteins, mucopolysaccharides, elastin and collagen. Photochemical or free radical damage to absorber or nearby organelles leads to pharmacological, ultrastructural, histological and clinical changes. Most frequent DNA damage is pyrimidine dimer formation, apparently inhibiting cell function and replication. This is largely enzymatically repaired in man in the dark by excision repair, post-replication repair and possible other enzymatic mechanisms, and at least in some organisms by light-induced photoreactivation repair. UVR exposure causes well recognized acute and chronic clinical syndromes in man. These are discussed in this paper

  4. Radiation risks and radiation protection at CRNL

    Radiation exposure is an occupational hazard at CRNL. The predicted health effects of low levels of radiation are described and compared with other hazards of living. Data related to the health of radiation workers are also considered. Special attention is given to the expected effects of radiation on the unborn child. Measures taken to protect CRNL employees against undue occupational exposure to radiation are noted

  5. Radiation. Protection. Health. Proceedings

    The topics of the meeting are the diagnostic and therapeutic application of ionizing radiations, the application of radiation in research, industry and engineering and radiation protection. The volume includes the following chapters: Radiation protection and society, radiation protection infrastructure, population and environment, metrology and measuring techniques, 1. Workshop on population and environment, NORM and radon, 2. Update: dose - extent of damage - limiting value definition, radiation protection for personnel (except medicine), radiation protection in medicine.

  6. 北京市西城区金融街社区30~50岁糖调节受损患者采用中药辨证施治的调查研究%Investigation on the effect of traditional Chinese medicine syndrome differentiation treatment in 30~50 years old patients with impaired glucose regulation in Jingrong street community of Beijing Xicheng district

    史凌燕

    2015-01-01

    Objective:To investigate the traditional Chinese medicine syndrome differentiation method in community people with impaired glucose regulation,and to evaluate its effect and feasibility.Methods:Using traditional Chinese medicine syndrome differ-entiation in patients with impaired glucose regulation,and observed the changes on related risk factors after treatment.Results:Af-ter the traditional Chinese medicine syndrome differentiation treatment,the levels of blood glucose,triglyceride,total cholesterol, glycosylated hemoglobin,C reactive protein and insulin peak were decreased significantly than before the treatment,and the differ-ences were statistically significant(P<0.05).Conclusion:The traditional Chinese medicine syndrome differentiation method can improve early insulin secretion,and reduce the diabetes risk factors in people with impaired glucose regulation significantly,so it is a very practical community treatment method.%目的:探讨社区糖调节受损人群的中药辨证施治方法并评价其效果、可行性。方法:通过中药辨证施治后观察糖调节受损的患者相关危险因素的变化。结果:通过中药辨证施治后患者血糖、甘油三酯、总胆固醇、糖化血红蛋白、C反应蛋白和胰岛素峰值较治疗前均明显下降,并且上述差异均具有统计学意义(P<0.05)。结论:中药辨证施治改善早期胰岛素分泌,明显降低糖调节受损人群的糖尿病危险因素水平,是一种比较实用的社区治疗方法。

  7. Remarks about the LNT-hormesis discrepancy and Cohen's theory on indoor radon

    Adaptive and stimulating effects of ionizing radiation occur at near natural doses. The phenomenon is known in literature as 'hormesis' but this disagrees with the linear no-threshold hypothesis on the dose effect relationship. Radiation hormesis goes beyond the notion that radiation has no deleterious effects at small doses; it is considered that at small doses there exist new effects beneficial to the organism. The LNT theories assume that there is no threshold below which the harmful effects, in linear proportion to the dose, cease to appear. Several recent Cohen's papers have reported strong negative association between home indoor radon and lung cancer risk. Following the average radon concentration in homes for 1,601 U.S. counties, the discrepancy of these data with prediction of the linear no-threshold theory LNT found by Cohen is about 20 standard deviations. Most epidemiologists have considered this fact to be spurious because no case-control study on this subject has exhibited a similar strong negative association. There are different opinions among scientists that have been widely discussed about the testing of the linear no-threshold theory with ecological data pointing out some factors responsible for this discrepancy. In this paper a critical analysis and presentation of different views on the validity of the ecological epidemiology and 'the hormesis' reported by Cohen is made. Also we will present new data and results of some recent case-control studies. (author)

  8. Radiation biophysics

    Summaries of research projects conducted during 1978 and 1979 are presented. The overall thrust of the research is aimed at understanding the effects of radiation on organisms. Specific subject areas include: the effects of heavy-particle beam nuclear interactions in tissue on dosimetry; tracer studies with radioactive fragments of heavy-ion beams; the effects of heavy/ions on human kidney cells and Chinese hamster cells; the response of a rhabdomyosarcoma tumor system in rats to heavy-ion beams; the use of heavy charged particles in radiotherapy of human cancer; heavy-ion radiography; the biological effects of high magnetic fields; central nervous system neurotoxicity; and biophysical studies on cell membranes

  9. Radiating Joy

    Marlies Gabriele Prinzl

    2012-12-01

    Full Text Available A bunch of cheerful boys. They were totally playing it up for the camera, indeed, that was something I noticed frequently during the walk through this poor area of Vasant Vihar: the children were keen on being photographed. They were posing, but I still love this image for the sheer raw energy and happy smiles that radiate from these children’s faces. Although they are not the poorest of the poor – they don’t live on the streets, they aren’t orphans and, even if they would probably be considered underweight by Western standards, they aren’t starving – they do live in poverty, in shabby homes and with probably no more than a change or two of clothes. And yet, the delight in their faces gives a feeling of hope. If children aren’t happy like this, where would we be in this world?

  10. Ionising radiation

    This issue of 'Revue Francaise de Metrologie' presents the 2006 activity report of the national laboratory of metrology and tests (LNE). This paper presents the metrology activities in the domain of ionizing radiations. These activities are shared between two laboratories: the LNE-LNHB (Henry Becquerel national laboratory), i.e. the national laboratory of metrology of CEA-Saclay, and the LMDN (laboratory of dose metrology), which belongs to IRSN-Cadarache (Institute of radioprotection and nuclear safety). The different activities reported here concern: the international comparisons and actions, the advances in the lyophilization process for the drying of radioactive solutions, the use of renewable dead-times for radionuclides activity measurement using the anticoincidence method, the establishment of dosimetry references for low- and medium-energy X-photons, the advances in electron paramagnetic resonance (EPR) technology, and other international and national actions. (J.S.)

  11. Environmental radiation

    The types of ionizing radiations from the atomic nucleus are explained, such as the beams alpha, beta and gamma. The definitions of spectrometry and nuclear traces have been included.The study presents two researches realized in Costa Rica on the radioactive nuclear and artificial elements in the environment. The first shown is the analysis of coastal sediments where explains which are radioactive artificial isotopes and the pollution that occurs in food, coastal sediments, fertilizers, the soil, the water and the air. Within the analysis techniques are the gamma spectrometry, alpha spectrometry and nuclear strokes. Among the conclusions of this initial investigation is shown that at Punta Leona descendants of Uranium and Thorium present lower concentrations in relation to the gulf and its variations are not important. In the following study the radon gas is analyzed in the human environment where is determined that it is the second generator that causes cancer in lungs after the tobacco. This work indicates that the doses come from natural and artificial sources of radiation for the public are a whole of 2.7 mSv/year, information provided by the UNSCEAR, 2000. The radon gas is inert and radioactive of atomic number 86, includes 23 isotopes and 3 natural isotopes. The radon is everywhere, as are houses and buildings, in Costa Rica it is located in old homes with little ventilation. It describes the equipment used for the detection of radon gas in the environment. Within the conclusions radon gas is concentrated in confined spaces which can be harmful to health. It is determined that enough ventilation in places of high concentrations of radon is important. Finally it is recommended to monitor the sites where can be detected high concentrations of radon and that they have important influx of people

  12. Lead for radiation shields

    Fabrication programme lead in radiation protection: lead bricks, radiation protection tables and windows, locks, lead containers, vaults and bunkers, radiation protection capsules as well as lead fillings for reactor aggregates. (RW/LH)

  13. Nuclear radiation in warfare

    The subject is covered in chapters, entitled: introduction; digest of nuclear weaponry (characteristics of nuclear weapons; effects of nuclear weapons other than ionizing radiation (fire-ball, fall-out, thermal radiation, blast wave, electromagnetic pulse); the nuclear arms race; war scenarios; biological effects of radiations on man (radiation doses; natural sources of radiation; acute effects of radiation; long-term somatic effects; genetic effects; factors affecting the biological response to radiation; internal exposure; synergistic effects; protection against radiation effects); radiations from nuclear explosions (initial radiation; fall-out; effects of fall-out on animal and plant life; contamination of water and food supplies by fall-out); radiation casualties in a nuclear war; effectiveness of civil defence; other warlike uses of radiation (attacks on civilian nuclear power installations; radiological warfare; terrorist activities); conclusion. (orig./HP)

  14. 'Radiating' victims

    There is no other continent the uranium and nuclear power industry is as closely connected with as with North America and so incurably entangled with as with the very United States. The extraction and processing of radiating materials in reservations or nearby makes the American Indians living on the Colorado plateau in the southwest, in the State of Washington or in the surroundings of the Black Hills suffer a lot. Oekozid extra reports on the injuries, the protest and dying of the victims, the radioactive devastation of the landscape, the cynical practice of the responsible political organs and the complicity of the Federal Republic of Germany. The author appeals for a new consciousness as regards to the dimension of human action and the knowledge of the fact that any anti-nuclear power/plutonium policy has to include putting a stop to uranium extraction and uranium processing. Warnings and admonitions the traditional Indians have been giving since 1948, have been ignored so far. (orig./HP)

  15. Synchrotron radiation

    Work at the Daresbury SRS has of necessity been interrupted this year (1991/92) due to the incorporation of Wiggler II. However, considerable beamtime was awarded before the shutdown and the major part of this appendix is concerned with the progress reports of the research undertaken then. The reports have been organised under the following broad headings: Molecular Science (19 papers), Surface and Materials Science (169 papers), Biological Science (85 papers), Instrumental and Technique Developments (13 papers) and Accelerator Physics (3 papers). It is hoped that in time the number of contributions on accelerator physics will grow to reflect the in-house activity on, for example, accelerator improvement and design. The research reports are preceded by the Annual Report of the Synchrotron Radiation Facilities Committee, which outlines the research highlights identified by that Committee (also included are details of the current membership of the SRFC and the chairmen of the Beamtime Allocation Panels). Following the reports are the specifications for the beamlines and stations. This year Section 3 contains 289 reports (nearly 100 more than last year) and the number of publications, generated by scientists and engineers who have used or are associated with Daresbury Laboratory facilities, has topped 500 for the first time. (author)

  16. Applying radiation

    The invention discloses a method and apparatus for applying radiation by producing X-rays of a selected spectrum and intensity and directing them to a desired location. Radiant energy is directed from a laser onto a target to produce such X-rays at the target, which is so positioned adjacent to the desired location as to emit the X-rays toward the desired location; or such X-rays are produced in a region away from the desired location, and are channeled to the desired location. The radiant energy directing means may be shaped (as with bends; adjustable, if desired) to circumvent any obstruction between the laser and the target. Similarly, the X-ray channeling means may be shaped (as with fixed or adjustable bends) to circumvent any obstruction between the region where the X-rays are produced and the desired location. For producing a radiograph in a living organism the X-rays are provided in a short pulse to avoid any blurring of the radiograph from movement of or in the organism. For altering tissue in a living organism the selected spectrum and intensity are such as to affect substantially the tissue in a preselected volume without injuring nearby tissue. Typically, the selected spectrum comprises the range of about 0.1 to 100 keV, and the intensity is selected to provide about 100 to 1000 rads at the desired location. The X-rays may be produced by stimulated emission thereof, typically in a single direction

  17. Radiation hazard

    Radiation hazards to infants in the treatment of malignant tumor were discussed. Late effects of radiotherapy in infants became an important problem in an increasing number of cases with prolonged survival periods. Late effects of radiotherapy included tumor and leukemia induction, as well as disturbance of growth in the eyes, bone, etc. In order to avoid iatrogenic disorders, physicians should be required to have adequate knowledge of the anatomy and physiology of normal tissue, and variations with age. Pathology of tumors and the condition of patients before and after resection should be thoroughly understood. To determine normal tissue tolerance dose, various function tests, especially radiological examinations, are required. Suspected tissue should be frequently biopsied, and clinical observations should also be frequent. Postoperative irradiation should be selected depending on the kind of lesion. In treatment, the younger the patient is, the less should be the dose applied, and the longer the overall time of application. Fields should be limited to an area somewhat larger than the tumor lesion except in the case of malignant lymphoma, when anticancer drugs are combined with radiotherapy. It is difficult to determine the normal tissue tolerance dose, and tolerance dose of normal infant tissue differs considerably by age. Based on the author's experience, tolerance doses for skin, brain, spinal cord, eyes, face, cervical area, and extremities were demonstrated. (S. MUKOHATA)

  18. Thermal radiation heat transfer

    Howell, John R; Siegel, Robert

    2016-01-01

    Further expanding on the changes made to the fifth edition, Thermal Radiation Heat Transfer, 6th Edition continues to highlight the relevance of thermal radiative transfer and focus on concepts that develop the radiative transfer equation (RTE). The book explains the fundamentals of radiative transfer, introduces the energy and radiative transfer equations, covers a variety of approaches used to gauge radiative heat exchange between different surfaces and structures, and provides solution techniques for solving the RTE.

  19. Radiation cataract

    This report reviews the relationship of ionizing radiation to the occurrence of cataracts (posterior lenticular opacities) among the A-bomb survivors in Hiroshima and Nagasaki. The new DS86 doses are available for 1,983 (93.4%) of the 2,124 A-bomb survivors analyzed in 1982. The DS86 kerma neutron component for Hiroshima is much smaller than its comparable T65DR component, but still 4.2 fold higher (0.38 Gy at 6 Gy) than that in Nagasaki (0.09 Gy at 6 Gy). Thus, if the eye is especially sensitive to neutrons, there may yet be some useful information on their effects, particularly in Hiroshima. Under the best fitting dose-response model, an L (gamma)-L (neutron) with two thresholds, both the gamma and neutron regression coefficients of the occurrence of cataracts on dose are positive and highly significant for the DS86 eye organ doses. The DS86 gamma coefficient is almost the same as that associated with the T65DR gamma dose, the ratio of the two coefficients being 1.1 (95% confidence limits: 0.5-2.3) for DS86 kerma in the individual dose data, and if the risks based on the DS86 eye organ dose and DS86 kerma are compared, the ratio is 1.3 (0.6-2.8). However, the risk estimates associated with neutron exposure are 6.4 (2.2-19.2) fold higher for the DS86 kerma than the T65DR kerma and 1.6 (0.5-2.3) fold higher for the DS86 eye organ dose than for the DS86 kerma. (author)

  20. Detection of Terahertz Radiation

    2015-01-01

    The present invention relates to a system for detecting terahertz radiation, a camera device, and a method for detecting terahertz radiation.......The present invention relates to a system for detecting terahertz radiation, a camera device, and a method for detecting terahertz radiation....

  1. Radiation and People

    Freilich, Florence G.

    1970-01-01

    Describes the development of radiation as a tool of medicine. Includes topics on history of radiation, electromagnetic spectrum, X-ray tubes, high energy machines, radioactive sources, artificial radioactivity, radioactive scanning, units, present radiation background, and effect of radiation on living tissue. (DS)

  2. Dictionary of radiation terms

    This book is written to arrange the terms of radiation, which deals with radiodiagnosis, radiation therapy, radioisotopes, measurement, management technique in fields of physics, chemistry and biology. It goes into details on electricity and device, roentgenography, and radiation physic with easy explanations to use in convenience. The terms of radiation on this book are in alphabetical order.

  3. Introduction to radiation biology

    This book is arranged in a logical sequence, starting from radiation physics and radiation chemistry, followed by molecular, subcellular and cellular effects and going on to the level of organism. Topics covered include applied radiobiology like modifiers of radiosensitivity, predictive assay, health physics, human genetics and radiopharmaceuticals. The topics covered are : 1. Radiation Physics, 2. Detection and Measurement of Radiation, 3. Radiation Chemistry, 4. DNA Damage and Repair, 5. Chromosomal Aberrations and Gene Mutations, 6. Cellular Radiobiology 7. Acute Radiation Effects, 8. Delayed Effects of Radiation, 9. Biological Basis of Radiotherapy, 10. Chemical Modifiers of Radiosensitivity, 11. Hyperthermia, 12. High LET Radiations in Cancer, Therapy, 13. Predictive Assays, 14. Radiation Effects on Embryos, 15. Human Radiation Genetics, 16. Radiolabelled Compounds in Biology and Medicine and 17. Radiological Health

  4. Radiation protection forum

    The National Director of the Nuclear Regulatory Authority and Radiation Protection of Uruguay in the first forum for radiation protection set out the following themes: activity of regulatory body, radiation safety, physical security, safeguards, legal framework, committed substantive program, use of radiation, risks and benefits, major sources of radiation, the national regulatory framework, national inventory of sources, inspections, licensing, import and export of sources control , radioactive transport, materials safety, agreements, information and teaching, radiological emergencies and prompt response.

  5. Wireless radiation sensor

    Lamberti, Vincent E.; Howell, Jr, Layton N.; Mee, David K.; Kress, Reid L.

    2016-08-09

    Disclosed is a sensor for detecting radiation. The sensor includes a ferromagnetic metal and a radiation sensitive material coupled to the ferromagnetic metal. The radiation sensitive material is operable to change a tensile stress of the ferromagnetic metal upon exposure to radiation. The radiation is detected based on changes in the magnetic switching characteristics of the ferromagnetic metal caused by the changes in the tensile stress.

  6. Radiation and toxix materials

    General radiobiological concepts in aviation medicine related to the biological effect of ionizing radiation on flying factors are presented. Principles of standartization, permissible doses, general principles of radiation protection and prophylaxis of aviation personnel are described. Characteristics of radio emission, microwaves, procedure of their measurements are given. Pathophysiology of electromagnetic radiation is presented. Problems on radiation protection, technical and organization problems on electromagnetic radiation protection, as well as technology in aviation are discussed

  7. Radiation Safety Compliance.

    Koth, Jana; Smith, Marcia Hess

    2016-05-01

    This article discusses radiation safety programs, including the members of the radiation safety team, their roles, and the challenges they face, with a focus on the radiation safety officer's duties. Agencies that regulate radiation safety also are described. The importance of minimizing patient dose, ensuring that dosimetry badges are worn correctly, and using therapeutic radioactive materials safely are addressed. Finally, radiologic technologists' role in using radiation safely is discussed, and the principles of time, distance, and shielding are reviewed. PMID:27146175

  8. Radiation physics, biophysics, and radiation biology

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiotherapy. Current research topics include: oncogenic transformation assays, mutation studies involving interactions between radiation and environmental contaminants, isolation, characterization and sequencing of a human repair gene, characterization of a dominant transforming gene found in C3H 10T1/2 cells, characterize ab initio the interaction of DNA and radiation, refine estimates of the radiation quality factor Q, a new mechanistic model of oncogenesis showing the role of long-term low dose medium LET radiation, and time dependent modeling of radiation induced chromosome damage and subsequent repair or misrepair

  9. From radiation chemistry to radiation engineering

    During the past 25 years there has been a steady recognition that radiation in the form of electrons or gamma rays can offer positive advantages as a processing technology. Underlying this process industry, and largely responsible for its success, are significant contributions from the field of basic and applied radiation chemistry. In this paper it is attempted to relate fundamental radiation chemistry studies directly to the practical engineering applications

  10. Fundamentals of radiation technologies

    The proceedings contain papers dealing with current trends in radiation technologies, the basic concepts of radiation technologies, the interaction of ionizing radiation with matter, and the foundations of radiation chemistry. Also described are the technical and economic principles of design and the use of radionuclide radiation sources and electron accelerators. The problems are discussed of radiosterilization, the radiation processing of polymers and their degradation, and the radiopreservation of cultural and museum objects. Also dealt with is the irradiation of foods and the impact of radiation technologies on the environment including radiation chemistry problems of nuclear power plants. The basic principles are explained of work safety in handling sources of ionizing radiation. (J.C.)