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Sample records for linear-no-threshold radiation risk

  1. The risk of low doses of ionising radiation and the linear no threshold relationship debate

    International Nuclear Information System (INIS)

    Tubiana, M.; Masse, R.; Vathaire, F. de; Averbeck, D.; Aurengo, A.

    2007-01-01

    The ICRP and the B.E.I.R. VII reports recommend a linear no threshold (L.N.T.) relationship for the estimation of cancer excess risk induced by ionising radiations (IR), but the 2005 report of Medicine and Science French Academies concludes that it leads to overestimate of risk for low and very low doses. The bases of L.N.T. are challenged by recent biological and animal experimental studies which show that the defence against IR involves the cell microenvironment and the immunologic system. The defence mechanisms against low doses are different and comparatively more effective than for high doses. Cell death is predominant against low doses. DNA repairing is activated against high doses, in order to preserve tissue functions. These mechanisms provide for multicellular organisms an effective and low cost defence system. The differences between low and high doses defence mechanisms are obvious for alpha emitters which show several greys threshold effects. These differences result in an impairment of epidemiological studies which, for statistical power purpose, amalgamate high and low doses exposure data, since it would imply that cancer IR induction and defence mechanisms are similar in both cases. Low IR dose risk estimates should rely on specific epidemiological studies restricted to low dose exposures and taking precisely into account potential confounding factors. The preliminary synthesis of cohort studies for which low dose data (< 100 mSv) were available show no significant risk excess, neither for solid cancer nor for leukemias. (authors)

  2. Radiation hormesis and the linear-no-threshold assumption

    CERN Document Server

    Sanders, Charles L

    2009-01-01

    Current radiation protection standards are based upon the application of the linear no-threshold (LNT) assumption, which considers that even very low doses of ionizing radiation can cause cancer. The radiation hormesis hypothesis, by contrast, proposes that low-dose ionizing radiation is beneficial. In this book, the author examines all facets of radiation hormesis in detail, including the history of the concept and mechanisms, and presents comprehensive, up-to-date reviews for major cancer types. It is explained how low-dose radiation can in fact decrease all-cause and all-cancer mortality an

  3. An experimental test of the linear no-threshold theory of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1990-01-01

    There is a substantial body of quantitative information on radiation-induced cancer at high dose, but there are no data at low dose. The usual method for estimating effects of low-level radiation is to assume a linear no-threshold dependence. if this linear no-threshold assumption were not used, essentially all fears about radiation would disappear. Since these fears are costing tens of billions of dollars, it is most important that the linear no-threshold theory be tested at low dose. An opportunity for possibly testing the linear no-threshold concept is now available at low dose due to radon in homes. The purpose of this paper is to attempt to use this data to test the linear no-threshold theory

  4. Validity of the linear no-threshold theory of radiation carcinogenesis at low doses

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1999-01-01

    A great deal is known about the cancer risk of high radiation doses from studies of Japanese A-bomb survivors, patients exposed for medical therapy, occupational exposures, etc. But the vast majority of important applications deal with much lower doses, usually accumulated at much lower dose rates, referred to as 'low-level radiation' (LLR). Conventionally, the cancer risk from LLR has been estimated by the use of linear no-threshold theory (LNT). For example, it is assumed that the cancer risk from 0 01 Sr (100 mrem) of dose is 0 01 times the risk from 1 Sv (100 rem). In recent years, the former risk estimates have often been reduced by a 'dose and dose rate reduction factor', which is taken to be a factor of 2. But otherwise, the LNT is frequently used for doses as low as one hundred-thousandth of those for which there is direct evidence of cancer induction by radiation. It is the origin of the commonly used expression 'no level of radiation is safe' and the consequent public fear of LLR. The importance of this use of the LNT can not be exaggerated and is used in many applications in the nuclear industry. The LNT paradigm has also been carried over to chemical carcinogens, leading to severe restrictions on use of cleaning fluids, organic chemicals, pesticides, etc. If the LNT were abandoned for radiation, it would probably also be abandoned for chemical carcinogens. In view of these facts, it is important to consider the validity of the LNT. That is the purpose of this paper. (author)

  5. Test of the linear-no threshold theory of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1998-01-01

    It is shown that testing the linear-no threshold theory (L-NT) of radiation carcinogenesis is extremely important and that lung cancer resulting from exposure to radon in homes is the best tool for doing this. A study of lung cancer rates vs radon exposure in U.S. Counties, reported in 1975, is reviewed. It shows, with extremely powerful statistics, that lung cancer rates decrease with increasing radon exposure, in sharp contrast to the prediction of L-NT, with a discrepancy of over 20 standard deviations. Very extensive efforts were made to explain an appreciable part of this discrepancy consistently with L-NT, with no success; it was concluded that L-NT fails, grossly exaggerating the cancer risk of low level radiation. Two updating studies reported in 1996 are also reviewed. New updating studies utilizing more recent lung cancer statistics and considering 450 new potential confounding factors are reported. All updates reinforce the previous conclusion, and the discrepancy with L-NT is increased. (author)

  6. Test of the linear-no threshold theory of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1994-01-01

    We recently completed a compilation of radon measurements from available sources which gives the average radon level, in homes for 1730 counties, well over half of all U.S. counties and comprising about 90% of the total U.S. population. Epidemiologists normally study the relationship between mortality risks to individuals, m, vs their personal exposure, r, whereas an ecological study like ours deals with the relationship between the average risk to groups of individuals (population of counties) and their average exposure. It is well known to epidemiologists that, in general, the average dose does not determine the average risk, and to assume otherwise is called 'the ecological fallacy'. However, it is easy to show that, in testing a linear-no threshold theory, 'the ecological fallacy' does not apply; in that theory, the average dose does determine the average risk. This is widely recognized from the fact that 'person-rem' determines the number of deaths. Dividing person-rem by population gives average dose, and dividing number of deaths by population gives mortality rate. Because of the 'ecological fallacy', epidemiology textbooks often state that an ecological study cannot determine a causal relationship between risk and exposure. That may be true, but it is irrelevant here because the purpose of our study is not to determine a causal relationship; it is rather to test the linear-no threshold dependence of m on r. (author)

  7. Linear, no threshold response at low doses of ionizing radiation: ideology, prejudice and science

    International Nuclear Information System (INIS)

    Kesavan, P.C.

    2014-01-01

    The linear, no threshold (LNT) response model assumes that there is no threshold dose for the radiation-induced genetic effects (heritable mutations and cancer), and it forms the current basis for radiation protection standards for radiation workers and the general public. The LNT model is, however, based more on ideology than valid radiobiological data. Further, phenomena such as 'radiation hormesis', 'radioadaptive response', 'bystander effects' and 'genomic instability' are now demonstrated to be radioprotective and beneficial. More importantly, the 'differential gene expression' reveals that qualitatively different proteins are induced by low and high doses. This finding negates the LNT model which assumes that qualitatively similar proteins are formed at all doses. Thus, all available scientific data challenge the LNT hypothesis. (author)

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

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1995-01-01

    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)

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

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1990-01-01

    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

  10. Common misinterpretations of the 'linear, no-threshold' relationship used in radiation protection

    International Nuclear Information System (INIS)

    Bond, V.P.; Sondhaus, C.A.

    1987-01-01

    Absorbed dose D is shown to be a composite variable, the product of the fraction of cells hit (I H ) and the mean ''dose'' (hit size) anti z to those cells. D is suitable for use with high level exposure (HLE) to radiation and its resulting acute organ effects because, since I H =1.0, it approximates closely enough the mean energy density in the cell as well as in the organ. However, the low level exposure (LLE) to radiation and its consequent probability of cancer induction from a single cell, stochastic delivery of energy to cells results in a wide distribution of hit sizes z, and the expected mean value, anti z, is constant with exposure. Thus, with LLE, only I H varies with D so that the apparent proportionality between ''dose'' and the fraction of cells transformed is misleading. This proportionality therefore does not mean that any (cell) dose, no matter how small, can be lethal. Rather, it means that, in the exposure of a population of individual organisms consisting of the constituent relevant cells, there is a small probability of particle-cell ineractions which transfer energy. The probability of a cell transforming and initiating a cancer can only be greater than zero if the hi t size (''dose'') to the cell is large enough. Otherwise stated, if the ''dose'' is defined at the proper level of biological organization, namely, the cell and not the organ, only a large dose z to that cell is effective. (orig.)

  11. Linear-No-Threshold Default Assumptions for Noncancer and Nongenotoxic Cancer Risks: A Mathematical and Biological Critique.

    Science.gov (United States)

    Bogen, Kenneth T

    2016-03-01

    To improve U.S. Environmental Protection Agency (EPA) dose-response (DR) assessments for noncarcinogens and for nonlinear mode of action (MOA) carcinogens, the 2009 NRC Science and Decisions Panel recommended that the adjustment-factor approach traditionally applied to these endpoints should be replaced by a new default assumption that both endpoints have linear-no-threshold (LNT) population-wide DR relationships. The panel claimed this new approach is warranted because population DR is LNT when any new dose adds to a background dose that explains background levels of risk, and/or when there is substantial interindividual heterogeneity in susceptibility in the exposed human population. Mathematically, however, the first claim is either false or effectively meaningless and the second claim is false. Any dose-and population-response relationship that is statistically consistent with an LNT relationship may instead be an additive mixture of just two quasi-threshold DR relationships, which jointly exhibit low-dose S-shaped, quasi-threshold nonlinearity just below the lower end of the observed "linear" dose range. In this case, LNT extrapolation would necessarily overestimate increased risk by increasingly large relative magnitudes at diminishing values of above-background dose. The fact that chemically-induced apoptotic cell death occurs by unambiguously nonlinear, quasi-threshold DR mechanisms is apparent from recent data concerning this quintessential toxicity endpoint. The 2009 NRC Science and Decisions Panel claims and recommendations that default LNT assumptions be applied to DR assessment for noncarcinogens and nonlinear MOA carcinogens are therefore not justified either mathematically or biologically. © 2015 The Author. Risk Analysis published by Wiley Periodicals, Inc. on behalf of Society for Risk Analysis.

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

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1987-01-01

    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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  14. Checking the foundation: recent radiobiology and the linear no-threshold theory.

    Science.gov (United States)

    Ulsh, Brant A

    2010-12-01

    The linear no-threshold (LNT) theory has been adopted as the foundation of radiation protection standards and risk estimation for several decades. The "microdosimetric argument" has been offered in support of the LNT theory. This argument postulates that energy is deposited in critical cellular targets by radiation in a linear fashion across all doses down to zero, and that this in turn implies a linear relationship between dose and biological effect across all doses. This paper examines whether the microdosimetric argument holds at the lowest levels of biological organization following low dose, low dose-rate exposures to ionizing radiation. The assumptions of the microdosimetric argument are evaluated in light of recent radiobiological studies on radiation damage in biological molecules and cellular and tissue level responses to radiation damage. There is strong evidence that radiation initially deposits energy in biological molecules (e.g., DNA) in a linear fashion, and that this energy deposition results in various forms of prompt DNA damage that may be produced in a pattern that is distinct from endogenous (e.g., oxidative) damage. However, a large and rapidly growing body of radiobiological evidence indicates that cell and tissue level responses to this damage, particularly at low doses and/or dose-rates, are nonlinear and may exhibit thresholds. To the extent that responses observed at lower levels of biological organization in vitro are predictive of carcinogenesis observed in vivo, this evidence directly contradicts the assumptions upon which the microdosimetric argument is based.

  15. On the origins of the linear no-threshold (LNT) dogma by means of untruths, artful dodges and blind faith

    International Nuclear Information System (INIS)

    Calabrese, Edward J.

    2015-01-01

    This paper is an historical assessment of how prominent radiation geneticists in the United States during the 1940s and 1950s successfully worked to build acceptance for the linear no-threshold (LNT) dose–response model in risk assessment, significantly impacting environmental, occupational and medical exposure standards and practices to the present time. Detailed documentation indicates that actions taken in support of this policy revolution were ideologically driven and deliberately and deceptively misleading; that scientific records were artfully misrepresented; and that people and organizations in positions of public trust failed to perform the duties expected of them. Key activities are described and the roles of specific individuals are documented. These actions culminated in a 1956 report by a Genetics Panel of the U.S. National Academy of Sciences (NAS) on Biological Effects of Atomic Radiation (BEAR). In this report the Genetics Panel recommended that a linear dose response model be adopted for the purpose of risk assessment, a recommendation that was rapidly and widely promulgated. The paper argues that current international cancer risk assessment policies are based on fraudulent actions of the U.S. NAS BEAR I Committee, Genetics Panel and on the uncritical, unquestioning and blind-faith acceptance by regulatory agencies and the scientific community. - Highlights: • The 1956 recommendation of the US NAS to use the LNT for risk assessment was adopted worldwide. • This recommendation is based on a falsification of the research record and represents scientific misconduct. • The record misrepresented the magnitude of panelist disagreement of genetic risk from radiation. • These actions enhanced public acceptance of their risk assessment policy recommendations.

  16. On the origins of the linear no-threshold (LNT) dogma by means of untruths, artful dodges and blind faith

    Energy Technology Data Exchange (ETDEWEB)

    Calabrese, Edward J., E-mail: edwardc@schoolph.umass.edu

    2015-10-15

    This paper is an historical assessment of how prominent radiation geneticists in the United States during the 1940s and 1950s successfully worked to build acceptance for the linear no-threshold (LNT) dose–response model in risk assessment, significantly impacting environmental, occupational and medical exposure standards and practices to the present time. Detailed documentation indicates that actions taken in support of this policy revolution were ideologically driven and deliberately and deceptively misleading; that scientific records were artfully misrepresented; and that people and organizations in positions of public trust failed to perform the duties expected of them. Key activities are described and the roles of specific individuals are documented. These actions culminated in a 1956 report by a Genetics Panel of the U.S. National Academy of Sciences (NAS) on Biological Effects of Atomic Radiation (BEAR). In this report the Genetics Panel recommended that a linear dose response model be adopted for the purpose of risk assessment, a recommendation that was rapidly and widely promulgated. The paper argues that current international cancer risk assessment policies are based on fraudulent actions of the U.S. NAS BEAR I Committee, Genetics Panel and on the uncritical, unquestioning and blind-faith acceptance by regulatory agencies and the scientific community. - Highlights: • The 1956 recommendation of the US NAS to use the LNT for risk assessment was adopted worldwide. • This recommendation is based on a falsification of the research record and represents scientific misconduct. • The record misrepresented the magnitude of panelist disagreement of genetic risk from radiation. • These actions enhanced public acceptance of their risk assessment policy recommendations.

  17. Molecular biology, epidemiology, and the demise of the linear no-threshold hypothesis

    International Nuclear Information System (INIS)

    Pollycove, M.

    1998-01-01

    The LNT hypothesis is the basic principle of all radiation protection policy. This theory assumes that all radiation doses, even those close to zero, are harmful in linear proportion to dose and that all doses produce a proportionate number of harmful mutations, i.e., mis- or unrepaired DNA alterations. The LNT theory is used to generate collective dose calculations of the number of deaths produced by minute fractions of background radiation. Current molecular biology reveals an enormous amount of relentless metabolic oxidative free radical damage with mis/unrepaired alterations of DNA. The corresponding mis/unrepaired DNA alterations produced by background radiation are negligible. These DNA alterations are effectively disposed of by the DNA damage-control biosystem of antioxidant prevention, enzymatic repair, and mutation removal. High-dose radiation injures this biosystem with associated risk increments of mortality and cancer mortality. Low-dose radiation stimulates DNA damage-control with associated epidemiologic observations of risk decrements of mortality and cancer mortality, i.e., hormesis. How can this 40-year-old LNT paradigm continue to be the operative principle of radiation protection policy despite the contradictory scientific observations of both molecular biology and epidemiology and the lack of any supportive human data? The increase of public fear through repeated statements of deaths caused by 'deadly' radiation has engendered an enormous increase in expenditures now required to 'protect' the public from all applications of nuclear technology: medical, research, energy, disposal, and cleanup remediation. Government funds are allocated to appointed committees, the research they support, and to multiple environmental and regulatory agencies. The LNT theory and multibillion dollar radiation activities have now become a symbiotic self-sustaining powerful political and economic force. (author)

  18. Response to, "On the origins of the linear no-threshold (LNT) dogma by means of untruths, artful dodges and blind faith.".

    Science.gov (United States)

    Beyea, Jan

    2016-07-01

    It is not true that successive groups of researchers from academia and research institutions-scientists who served on panels of the US National Academy of Sciences (NAS)-were duped into supporting a linear no-threshold model (LNT) by the opinions expressed in the genetic panel section of the 1956 "BEAR I" report. Successor reports had their own views of the LNT model, relying on mouse and human data, not fruit fly data. Nor was the 1956 report biased and corrupted, as has been charged in an article by Edward J. Calabrese in this journal. With or without BEAR I, the LNT model would likely have been accepted in the US for radiation protection purposes in the 1950's. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1992-01-01

    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

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

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1996-01-01

    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

  1. Lessons to be learned from a contentious challenge to mainstream radiobiological science (the linear no-threshold theory of genetic mutations).

    Science.gov (United States)

    Beyea, Jan

    2017-04-01

    There are both statistically valid and invalid reasons why scientists with differing default hypotheses can disagree in high-profile situations. Examples can be found in recent correspondence in this journal, which may offer lessons for resolving challenges to mainstream science, particularly when adherents of a minority view attempt to elevate the status of outlier studies and/or claim that self-interest explains the acceptance of the dominant theory. Edward J. Calabrese and I have been debating the historical origins of the linear no-threshold theory (LNT) of carcinogenesis and its use in the regulation of ionizing radiation. Professor Calabrese, a supporter of hormesis, has charged a committee of scientists with misconduct in their preparation of a 1956 report on the genetic effects of atomic radiation. Specifically he argues that the report mischaracterized the LNT research record and suppressed calculations of some committee members. After reviewing the available scientific literature, I found that the contemporaneous evidence overwhelmingly favored a (genetics) LNT and that no calculations were suppressed. Calabrese's claims about the scientific record do not hold up primarily because of lack of attention to statistical analysis. Ironically, outlier studies were more likely to favor supra-linearity, not sub-linearity. Finally, the claim of investigator bias, which underlies Calabrese's accusations about key studies, is based on misreading of text. Attention to ethics charges, early on, may help seed a counter narrative explaining the community's adoption of a default hypothesis and may help focus attention on valid evidence and any real weaknesses in the dominant paradigm. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Lessons to be learned from a contentious challenge to mainstream radiobiological science (the linear no-threshold theory of genetic mutations)

    International Nuclear Information System (INIS)

    Beyea, Jan

    2017-01-01

    There are both statistically valid and invalid reasons why scientists with differing default hypotheses can disagree in high-profile situations. Examples can be found in recent correspondence in this journal, which may offer lessons for resolving challenges to mainstream science, particularly when adherents of a minority view attempt to elevate the status of outlier studies and/or claim that self-interest explains the acceptance of the dominant theory. Edward J. Calabrese and I have been debating the historical origins of the linear no-threshold theory (LNT) of carcinogenesis and its use in the regulation of ionizing radiation. Professor Calabrese, a supporter of hormesis, has charged a committee of scientists with misconduct in their preparation of a 1956 report on the genetic effects of atomic radiation. Specifically he argues that the report mischaracterized the LNT research record and suppressed calculations of some committee members. After reviewing the available scientific literature, I found that the contemporaneous evidence overwhelmingly favored a (genetics) LNT and that no calculations were suppressed. Calabrese's claims about the scientific record do not hold up primarily because of lack of attention to statistical analysis. Ironically, outlier studies were more likely to favor supra-linearity, not sub-linearity. Finally, the claim of investigator bias, which underlies Calabrese's accusations about key studies, is based on misreading of text. Attention to ethics charges, early on, may help seed a counter narrative explaining the community's adoption of a default hypothesis and may help focus attention on valid evidence and any real weaknesses in the dominant paradigm. - Highlights: • Edward J Calabrese has made a contentious challenge to mainstream radiobiological science. • Such challenges should not be neglected, lest they enter the political arena without review. • Key genetic studies from the 1940s, challenged by Calabrese, were

  3. Lessons to be learned from a contentious challenge to mainstream radiobiological science (the linear no-threshold theory of genetic mutations)

    Energy Technology Data Exchange (ETDEWEB)

    Beyea, Jan, E-mail: jbeyea@cipi.com

    2017-04-15

    There are both statistically valid and invalid reasons why scientists with differing default hypotheses can disagree in high-profile situations. Examples can be found in recent correspondence in this journal, which may offer lessons for resolving challenges to mainstream science, particularly when adherents of a minority view attempt to elevate the status of outlier studies and/or claim that self-interest explains the acceptance of the dominant theory. Edward J. Calabrese and I have been debating the historical origins of the linear no-threshold theory (LNT) of carcinogenesis and its use in the regulation of ionizing radiation. Professor Calabrese, a supporter of hormesis, has charged a committee of scientists with misconduct in their preparation of a 1956 report on the genetic effects of atomic radiation. Specifically he argues that the report mischaracterized the LNT research record and suppressed calculations of some committee members. After reviewing the available scientific literature, I found that the contemporaneous evidence overwhelmingly favored a (genetics) LNT and that no calculations were suppressed. Calabrese's claims about the scientific record do not hold up primarily because of lack of attention to statistical analysis. Ironically, outlier studies were more likely to favor supra-linearity, not sub-linearity. Finally, the claim of investigator bias, which underlies Calabrese's accusations about key studies, is based on misreading of text. Attention to ethics charges, early on, may help seed a counter narrative explaining the community's adoption of a default hypothesis and may help focus attention on valid evidence and any real weaknesses in the dominant paradigm. - Highlights: • Edward J Calabrese has made a contentious challenge to mainstream radiobiological science. • Such challenges should not be neglected, lest they enter the political arena without review. • Key genetic studies from the 1940s, challenged by Calabrese, were

  4. Epidemiology and risk assessment for radiation

    International Nuclear Information System (INIS)

    Badwe, R.A.

    2014-01-01

    The hazard and exposures from radiation are known with reasonable accuracy. However, at 'low levels' uncertainty persists as to whether the dose response relationship is linear and whether there is a dose threshold, below which there is no risk. Some have proposed that 'low' exposures to radiation may be beneficial, a hypothesis referred to as 'hormesis'. Over recent decades, various expert groups have adopted linear no-threshold dose-response models for radiation and cancer, based on review of epidemiological and biological evidence. The unexpected epidemic of thyroid cancer among children following the Chernobyl disaster was noticed. The research with epidemiological data and knowledge of the radionuclides to which the children were exposed is needed. Currently a debate concerning potential risks of high frequency electromagnetic radiation from mobile phones illustrates another need for further research

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

    International Nuclear Information System (INIS)

    Higson, D.

    2001-01-01

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

  6. Biological Bases for Radiation Adaptive Responses in the Lung

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Bobby R. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Lin, Yong [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Wilder, Julie [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Belinsky, Steven [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States)

    2015-03-01

    Our main research objective was to determine the biological bases for low-dose, radiation-induced adaptive responses in the lung, and use the knowledge gained to produce an improved risk model for radiation-induced lung cancer that accounts for activated natural protection, genetic influences, and the role of epigenetic regulation (epiregulation). Currently, low-dose radiation risk assessment is based on the linear-no-threshold hypothesis, which now is known to be unsupported by a large volume of data.

  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

    Energy Technology Data Exchange (ETDEWEB)

    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. The risk equivalent of an exposure to-, versus a dose of radiation

    International Nuclear Information System (INIS)

    Bond, V.P.

    1986-01-01

    The long-term potential carcinogenic effects of low-level exposure (LLE) are addressed. The principal point discussed is linear, no-threshold dose-response curve. That the linear no-threshold, or proportional relationship is widely used is seen in the way in which the values for cancer risk coefficients are expressed - in terms of new cases, per million persons exposed, per year, per unit exposure or dose. This implies that the underlying relationship is proportional, i.e., ''linear, without threshold''. 12 refs., 9 figs., 1 tab

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

    International Nuclear Information System (INIS)

    Guillerman, R.P.

    2014-01-01

    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.)

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

    International Nuclear Information System (INIS)

    Suzuki, Keiji; Mitsutake, Norisato; Yamashita, Shunichi

    2012-01-01

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  12. Diagnostic radiation risks

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, T [Addenbrooke' s Hospital, Cambridge (UK)

    1980-04-01

    A brief discussion on diagnostic radiation risks is given. First some fundamental facts on the concepts and units of radiation measurement are clarified. Medical diagnostic radiation doses are also compared to the radiation doses received annually by man from natural background radiation. The controversy concerning the '10-day rule' in X-raying women of child-bearing age is discussed; it would appear that the risk of malformation in an unborn child due to X-radiation is very much less than the natural level of risk of malformation. The differences in the radiographic techniques and thus the different X-ray doses needed to make adequate X-ray images of different parts of the body are considered. The radiation burden of nuclear medicine investigations compared to X-ray procedures is also discussed. Finally, the problems of using volunteers in radiation research are aired.

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

    International Nuclear Information System (INIS)

    Otsuka, Kensuke; Hamada, Nobuyuki; Iwasaki, Toshiyasu; Yoshida, Kazuo

    2011-01-01

    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)

  14. Risks for radiation workers

    International Nuclear Information System (INIS)

    Rotblat, J.

    1978-01-01

    The following topics are discussed: recommendations of the International Commission on Radiological Protection; methods for determining dose limits to workers; use of data from survivors of Hiroshima and Nagasaki for estimating risk factors; use of data from survivors of nuclear explosions in Marshall Islands, uranium miners, and patients exposed to diagnostic and therapeutic radiation; risk factors for radioinduced malignancies; evidence that risk factors for persons exposed to partial-body radiation and Japanese survivors are too low; greater resistance of A-bomb survivors to radiation; and radiation doses received by U.K. medical workers and by U.K. fuel reprocessing workers. It is suggested that the dose limit for radiation workers should be reduced by a factor of 5

  15. Radiation risks in pregnancy

    International Nuclear Information System (INIS)

    Mossman, K.L.; Hill, L.T.

    1982-01-01

    A major contraindication of radiodiagnostic procedures is pregnancy. Approximately 1% of all pregnant women are given abdominal x-rays during the first trimester of pregnancy. Evaluation of radiation exposure should involve consideration of the types of examinations performed and when performed, as well as radiation dose and risk estimation. This information is then weighed against other possible risks of the pregnancy as well as personal factors. In the authors' experiences, radiation exposures usually result in doses to the embryo of less than 5 cGy (rad); the resulting radiation risks are usually small compared with other risks of pregnancy. Procedures to minimize diagnostic x-ray exposure of the fetus are also discussed

  16. Radiation risk estimation

    International Nuclear Information System (INIS)

    Schull, W.J.; Texas Univ., Houston, TX

    1992-01-01

    Estimation of the risk of cancer following exposure to ionizing radiation remains largely empirical, and models used to adduce risk incorporate few, if any, of the advances in molecular biology of a past decade or so. These facts compromise the estimation risk where the epidemiological data are weakest, namely, at low doses and dose rates. Without a better understanding of the molecular and cellular events ionizing radiation initiates or promotes, it seems unlikely that this situation will improve. Nor will the situation improve without further attention to the identification and quantitative estimation of the effects of those host and environmental factors that enhance or attenuate risk. (author)

  17. Perception of radiation risks

    International Nuclear Information System (INIS)

    Brenot, J.

    1992-01-01

    Perception of risks by people depends on many factors, either characterizing the individuals, or specific to the risk sources. The risk concept, which confuses the issue, is precised first. Second, the perception phenomenon is presented as an interactive process involving the individual, the hazard, and the social context. Third, dimensions of perception are listed and used to describe the perception of radiation risks. Finally, the relation between perception and attitude is clarified. (author) 50 refs

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

    International Nuclear Information System (INIS)

    Neill, R.H.

    1997-01-01

    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)

  19. Radiation. Doses, effect, risk

    International Nuclear Information System (INIS)

    Vapirev, E.; Todorov, P.

    1994-12-01

    This book outlines in a popular form the topic of ionizing radiation impacts on living organisms. It contains data gathered by ICRP for a period of 35 years. The essential dosimetry terms and units are presented. Natural and artificial sources of ionizing radiation are described. Possible biological radiation effects and diseases as a consequence of external and internal irradiation at normal and accidental conditions are considered. An assessment of genetic risk for human populations is presented and the concept of 'acceptable risk' is discussed

  20. Donor-specific cell-based assays in studying sensitivity to low-dose radiation: a population-based perspective

    Directory of Open Access Journals (Sweden)

    Dora eIl'yasova

    2014-11-01

    Full Text Available Currently, a linear no-threshold model is used to estimate health risks associated with exposure to low-dose radiation, a prevalent exposure in the general population, because the direct estimation from epidemiological studies suffers from uncertainty. This model has been criticized based on unique biology of low-dose radiation. Whether the departure from linearity is toward increased or decreased risk is intensely debated. We present an approach based on individual radiosensitivity testing and discuss how individual radiosensitivity can be assessed with the goal to develop a quantifiable measure of cellular response that can be conducted via high-throughput population testing.

  1. Radiation and risk

    International Nuclear Information System (INIS)

    Jacobi, W.

    1983-01-01

    From the beginnings of the peaceful utilization of nuclear energy, the principles of prevention and optimization have greatly limited the emission of radioactive substances. In this way, the radiation exposure associated with emissions from nuclear power plants during normal operation has been kept low compared with natural radiation exposure and its variance. This also applies to the local public in the vicinities of such plants. The present health hazard to the public arising from ionizing radiation is only a small fraction of the man-made risk to which the public is exposed in this country. This is also due to the fact that radiation protection employs the principle of prevention, which has been laid down in legal regulations. In this respect, the concepts and criteria developed in radiation protection for evaluation, limitation and optimization may be useful examples to other areas of safety at work and environmental protection. The acceptance of nuclear power is decisively influenced by the remaining residual risk of accidents. Extremely careful inspection and supervision of the technical safety of such plants is indispensable to prevent major accidents. The German Risk Study for Nuclear Power Plants has made an important contribution to this end. It is being continued. However, risk research must always be accompanied by risk comparison to allow numerical risk data to be evaluated properly and important features to be distinguished from unimportant ones. (orig.) [de

  2. Management of radiation risk

    International Nuclear Information System (INIS)

    Hubert, P.

    1996-01-01

    The need to control the risk from ionizing radiation can be tracked back to the eve of the twentieth century. However, as knowledge improved and practices expanded, the approaches to this control have evolved. No longer is the mere respect of some forms of exposure limits or safety related standards sufficient. Rather, it is widely admitted that there is a need for managing radiation risk, both by balancing the advantages and disadvantages of enhancing protection and by setting up a proper organization that allows handling of the risk. This paper describes the multiple aspects of radiation risk management and points out the main related issues. It critically analyzes ALARA and ICRP recommendations. 74 refs, 8 figs, 5 tabs

  3. Cancer risk of low dose/low dose rate radiation: a meta-analysis of cancer data of mammals exposed to low doses of radiation

    International Nuclear Information System (INIS)

    Ogata, Hiromitsu; Magae, Junji

    2008-01-01

    Full text: Linear No Threshold (LNT) model is a basic theory for radioprotection, but the adaptability of this hypothesis to biological responses at low doses or at low dose rates is not sufficiently investigated. Simultaneous consideration of the cumulative dose and the dose rate is necessary for evaluating the risk of long-term exposure to ionizing radiation at low dose. This study intends to examine several numerical relationships between doses and dose rates in biological responses to gamma radiation. Collected datasets on the relationship between dose and the incidence of cancer in mammals exposed to low doses of radiation were analysed using meta-regression models and modified exponential (MOE) model, which we previously published, that predicts irradiation time-dependent biological response at low dose rate ionizing radiation. Minimum doses of observable risk and effective doses with a variety of dose rates were calculated using parameters estimated by fitting meta-regression models to the data and compared them with other statistical models that find values corresponding to 'threshold limits'. By fitting a weighted regression model (fixed-effects meta-regression model) to the data on risk of all cancers, it was found that the log relative risk [log(RR)] increased as the total exposure dose increased. The intersection of this regression line with the x-axis denotes the minimum dose of observable risk. These estimated minimum doses and effective doses increased with decrease of dose rate. The goodness of fits of MOE-model depended on cancer types, but the total cancer risk is reduced when dose rates are very low. The results suggest that dose response curve for cancer risk is remarkably affected by dose rate and that dose rate effect changes as a function of dose rate. For scientific discussion on the low dose exposure risk and its uncertainty, the term 'threshold' should be statistically defined, and dose rate effects should be included in the risk

  4. Homeopathy with radiation?

    International Nuclear Information System (INIS)

    Kiefer, Juergen

    2017-01-01

    There are no reliable data to estimate radiation risk to humans below doses of about 100 mSv. The ICRP adopts for protection purposes the LNT(linear no threshold)-concept. As there is no evidence for its general validity there is room for other ideas. One is ''radiation hormesis'', i.e. the notion that low radiation doses are not harmful but rather beneficial to human health. This view is critically discussed and it is shown that there is no evidence to prove this conception neither from epidemiological studies nor convincingly from animal experiments or mechanistic investigations. There is, therefore, no reason to abandon the prudent approach of the ALARA-principle.

  5. Radiation risk estimation

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1981-11-01

    This report outlines the major publications between 1976 and 1981 that have contributed to the evolution of the way in which radiation risks (cancer and hereditary birth defects) are assessed. The publications include the latest findings of the UNSCEAR, BEIR and ICRP committees, epidemiological studies at low doses and new assessments of the doses received by the Japanese A-bomb survivors. This report is not a detailed critique of those publications, but it highlights the impact of their findings on risk assessment

  6. Why we need new approaches to low-dose risk modeling

    International Nuclear Information System (INIS)

    Alvarez, J.L.; Seiler, F.A.

    1996-01-01

    The linear no-threshold model for radiation effects was introduced as a conservative model for the design of radiation protection programs. The model has persisted not only as the basis for such programs, but has come to be treated as a dogma and is often confused with scientific fact. In this examination a number of serious problems with the linear no-threshold model of radiation carcinogenesis were demonstrated, many of them invalidating the hypothesis. It was shown that the relative risk formalism did not approach 1 as the dose approaches zero. When morality ratios were used instead, the data in the region below 0.3 Sv were systematically below the predictions of the linear model. It was also shown that the data above 0.3 Sv were of little use in formulating a model at low doses. In addition, these data are valid only for doses accumulated at high dose rates, and there is no scientific justification for using the model in low-dose, low-dose-rate extrapolations for purposes of radiation protection. Further examination of model fits to the Japanese survivor data were attempted. Several such models were fit to the data including an unconstrained linear, linear-square root, and Weibull, all of which fit the data better than the relative risk, linear no-threshold model. These fits were used to demonstrate that the linear model systematically over estimates the risk at low doses in the Japanese survivor data set. It is recommended here that an unbiased re-analysis of the data be undertaken and the results used to construct a new model, based on all pertinent data. This model could then form the basis for managing radiation risks in the appropriate regions of dose and dose rate

  7. Radiation risks in perspective

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1987-01-01

    The problem of risk assessment is greater at the low effective dose rates now observed in the majority of all forms of exposure, usually of less than 3 mSv per year from natural causes, from occupational exposure, and from exposure of 'critical groups' of the general public. For most populations there are particular problems also in epidemiological studies at low dose, in addition to those due to the very large numbers of person-years that need to be studied and the long latencies of most radiation effects. Adequate estimates can, however, now be made of the carcinogenic risk of exposure at higher dose of various organs selectively and of the whole body uniformly, and of modes of inference to the risk at lower dose. Estimates can also be made of the risks of inducing major types of inheritable and developmental abnormality. An essential step in viewing the sum of all such radiation risks in the perspective of other occupational and public risks must now be to develop an informed consensus on the relative weight that is regarded as attaching to hazards of different kind and severity. (author)

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

    Science.gov (United States)

    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 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

  9. Genetic risks from radiation

    International Nuclear Information System (INIS)

    Selby, P.B.

    Two widely-recognized committees, UNSCEAR and BEIR, have reevaluated their estimates of genetic risks from radiation. Their estimates for gene mutations are based on two different approaches, one being the doubling-dose approach and the other being a new direct approach based on an empirical determination of the amount of dominant induced damage in the skeletons of mice in the first generation following irradiation. The estimates made by these committees are in reasonably good agreement and suggest that the genetic risks from present exposures resultng from nuclear power production are small. There is room for much improvement in the reliability of the risk estimates. The relatively new approach of measuring the amount of induced damage to the mouse skeleton shows great promise of improving knowledge about how changes in the mutation frequency affect the incidence of genetic disorders. Such findings may have considerable influence on genetic risk estimates for radiation and on the development of risk estimates for other less-well-understood environmental mutagens. (author)

  10. Low dose radiation and ALARA: the potential risks to patients and staff from alpha-therapy

    International Nuclear Information System (INIS)

    Priest, N.D.

    2014-01-01

    This year a new drug containing radium-223, an alpha-emitting radionuclide, was approved for use by the US Food and Drug Administration for the palliative treatment of advanced prostate cancer metastases. Other drugs containing short-lived alpha-emitters are on clinical trial in Europe. Commonly, these employ a radionuclide attached to an antibody that specifically targets tumor cells to produce a highly localized radio-therapeutic dose to the tumor. However, normal tissues within the body will also be irradiated, albeit sometimes at low dose, and the question arises as to whether this presents a significant additional risk to the patient. Similarly, medical staff that handle these radionuclides could receive intakes of the radionuclides. What is the risk to staff? To assess the risk resulting from small tissue alpha-doses the toxicological, both human and animal, database was re-examined. The results of 20 epidemiological and toxicological studies with alpha-emitting radionuclides were analysed. In all cases a polynomial function provided a better fit to the data than a linear, no thresholds function. Also, in 19 cases a threshold dose below which no cancer is seen was indicated. The position of this threshold varied according to cancer type, but was typically in the range 0.1 to 1.0Gy of tissue dose - with a mean of 0.5Gy. It is concluded that alpha-radiation induced tumorogenesis is a threshold response and that as long as tissue doses are kept below these thresholds no additional cancers would be seen in either patients receiving alpha-therapy or in staff exposed to 'spilt' radionuclide. The presence of thresholds questions the appropriateness of current ALARA practices that are mostly used to drive occupational alpha-radiation exposures to as close to zero as possible. (author)

  11. Low dose radiation and ALARA: the potential risks to patients and staff from alpha-therapy

    Energy Technology Data Exchange (ETDEWEB)

    Priest, N.D. [Atomic Energy of Canada Limited, Chalk River, ON (Canada)

    2014-07-01

    This year a new drug containing radium-223, an alpha-emitting radionuclide, was approved for use by the US Food and Drug Administration for the palliative treatment of advanced prostate cancer metastases. Other drugs containing short-lived alpha-emitters are on clinical trial in Europe. Commonly, these employ a radionuclide attached to an antibody that specifically targets tumor cells to produce a highly localized radio-therapeutic dose to the tumor. However, normal tissues within the body will also be irradiated, albeit sometimes at low dose, and the question arises as to whether this presents a significant additional risk to the patient. Similarly, medical staff that handle these radionuclides could receive intakes of the radionuclides. What is the risk to staff? To assess the risk resulting from small tissue alpha-doses the toxicological, both human and animal, database was re-examined. The results of 20 epidemiological and toxicological studies with alpha-emitting radionuclides were analysed. In all cases a polynomial function provided a better fit to the data than a linear, no thresholds function. Also, in 19 cases a threshold dose below which no cancer is seen was indicated. The position of this threshold varied according to cancer type, but was typically in the range 0.1 to 1.0Gy of tissue dose - with a mean of 0.5Gy. It is concluded that alpha-radiation induced tumorogenesis is a threshold response and that as long as tissue doses are kept below these thresholds no additional cancers would be seen in either patients receiving alpha-therapy or in staff exposed to 'spilt' radionuclide. The presence of thresholds questions the appropriateness of current ALARA practices that are mostly used to drive occupational alpha-radiation exposures to as close to zero as possible. (author)

  12. Radiation effects and radiation risks

    International Nuclear Information System (INIS)

    Lengfelder, E.; Forst, D.; Feist, H.; Pratzel, H.

    1988-01-01

    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 [de

  13. Risk Factors: Radiation

    Science.gov (United States)

    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.

  14. Total Risk Management for Low Dose Radiation Exposures

    International Nuclear Information System (INIS)

    Simic, Z.; Mikulicic, V.; Sterc, D.

    2012-01-01

    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

  15. The risks of radiation

    Science.gov (United States)

    Miettenen, Jorma K.

    1988-01-01

    The risks of radioactivity are a really complicated matter, yet they are much better known than are the risks relating to thousands of chemical poisons that occur in our environment. The greatest mistakes are probably made in the definition of safety margins. Except for the bombs dropped in Japan and one other case in the Marshall Islands, there has always—luckily—been a wide safety margin between fallout radiation and doses dangerous to health; the margin has actually been about 1000-fold. The Chernobyl dose of 0.5 mGy/year that we received is only 1/1000 of the acute dose of 0.5 Gy which would cause a slight and nonpermanent change in the blood picture. There is no such safety margin with respect to many air pollutants. The safety standards for sulfuric or nitric oxides, ozone and so on, have been set only just below the level that already causes a health hazard, and these standards are exceeded once in a while. Otherwise, traffic would have to be forbidden and many industrial plants, especially power stations using coal, would have to stop working whenever a low-temperature inversion occurred. Environmental radioactivity does not represent a likely health risk in Finland unless a nuclear war breaks out. Air pollutants, on the contrary, are a real and almost daily health risk that should be carefully considered when decisions about our energy production are being made. In spite of what happened at Chernobyl, global consumption of nuclear power will double by the year 2000, since there are about 140 nuclear power plants presently under construction. It is not likely that another catastrophe like Chernobyl will happen, yet nuclear plant accidents are of course possible, even if their likelihood is diminished by improving reactor safety and even if any eventual damage could be expected to be smaller. If a reactor is hooded by a containment structure, no significant release of radioactive materials should be possible even in case of an accident. However, we must

  16. Radiation exposures: risks and realities

    International Nuclear Information System (INIS)

    Ganesh, G.

    2010-01-01

    Discovery of radioactivity in 1869 by Henry Becquerel and artificial radioactivity by Irene Curie in 1934 led to the development of nuclear field and nuclear materials in 20th century. They are widely used for man-kind across the globe in electricity production, carbon dating, treatment and diagnosis of diseases etc. While deriving benefits and utilizing nuclear resources for the benefit of man-kind, it is inevitable that exposure to radiation can not be avoided. Radiation exists all around us either natural or man-made which can not be totally eliminated or avoided. Radiation exposures from natural background contribute 2.4 to 3.6 mSv in a year. Radiation exposures incurred by a member of public due to nuclear industries constitute less than one hundredth of annual dose due to natural background. Hence it is important to understand the risk posed by radiation and comparison of radiation risk with various risks arising due to other sources. Studies have indicated that risks due to environmental pollution, cigarette smoking, alcohol consumption, heart diseases are far higher in magnitude compared to radiation risks from man made sources. This paper brings about the details and awareness regarding radiation exposures, radiation risk, various risks associated with other industries and benefits of radiation exposures. (author)

  17. Radiation, ecology and the invalid LNT model: the evolutionary imperative.

    Science.gov (United States)

    Parsons, Peter A

    2006-09-27

    Metabolic and energetic efficiency, and hence fitness of organisms to survive, should be maximal in their habitats. This tenet of evolutionary biology invalidates the linear-no threshold (LNT) model for the risk consequences of environmental agents. Hormesis in response to selection for maximum metabolic and energetic efficiency, or minimum metabolic imbalance, to adapt to a stressed world dominated by oxidative stress should therefore be universal. Radiation hormetic zones extending substantially beyond common background levels, can be explained by metabolic interactions among multiple abiotic stresses. Demographic and experimental data are mainly in accord with this expectation. Therefore, non-linearity becomes the primary model for assessing risks from low-dose ionizing radiation. This is the evolutionary imperative upon which risk assessment for radiation should be based.

  18. Radiation risk and radiation protection concepts

    International Nuclear Information System (INIS)

    Doerschel, B.

    1989-01-01

    The revised dosimetry for the survivors of Hiroshima and Nagasaki implies an increased risk from low LET radiation compared with that currently used. During its meeting in 1987 the ICRP stated that the new data at present do not require any change in the dose limits. However, two other factors can cause larger changes in the present risk estimates. Firstly, for some types of cancer the relative risk model seems to describe the observed data better than the absolute risk model currently used by the ICRP. Secondly, the shape of the dose-response relationship considerably influences the derived risks. In the present paper the factor causing a substantial increase in radiation risk are analyzed. Conclusions are drawn in how far a change in the currently recommended dose limits seems to be necessary. (author)

  19. Calculating Risk: Radiation and Chernobyl.

    Science.gov (United States)

    Gale, Robert Peter

    1987-01-01

    Considers who is at risk in a disaster such as Chernobyl. Assesses the difficulty in translating information regarding radiation to the public and in determining the acceptability of technological risks. (NKA)

  20. Homeopathy with radiation?; Homoeopathie mit Strahlen?

    Energy Technology Data Exchange (ETDEWEB)

    Kiefer, Juergen

    2017-07-01

    There are no reliable data to estimate radiation risk to humans below doses of about 100 mSv. The ICRP adopts for protection purposes the LNT(linear no threshold)-concept. As there is no evidence for its general validity there is room for other ideas. One is ''radiation hormesis'', i.e. the notion that low radiation doses are not harmful but rather beneficial to human health. This view is critically discussed and it is shown that there is no evidence to prove this conception neither from epidemiological studies nor convincingly from animal experiments or mechanistic investigations. There is, therefore, no reason to abandon the prudent approach of the ALARA-principle.

  1. Does radiation risk exist?

    International Nuclear Information System (INIS)

    Passchier, W.

    1996-01-01

    Risk assessment and risk management are parts of a dynamic process with the objective to decide on the tolerability of risk and on measures to keep risk within accepted limits. It enables all relevant parties to express their concerns and preferences regarding the different options for the human action involved and regarding the relative importance of criteria to decide on the tolerability of risk. Risk assessment has three phases; problem definition, risk analysis and risk characterization. Risk analysis is primarily a technical and scientific endeavour. With regard to problem definition and ride characterization consultation between risk assessors and risk managers (and other parties concerned) is a must. (author)

  2. Perception of risk from radiation

    International Nuclear Information System (INIS)

    Slovic, P.

    1996-01-01

    Perceptions of risk from radiation have been studied systematically for about 20 years. This paper summarises the key findings and conclusions from this research with regard to the nature of risk perceptions, the impacts of these perceptions, and the need for communication about radiological hazards. Perhaps the most important generalisation from research in this area is that there is no uniform or consistent perception of radiation risks. Public perception and acceptance is determined by the context in which the radiation is used -and the very different reactions to different uses provide insight into the nature of perception and the determinants of acceptable risk. (author)

  3. Ionizing radiation: benefits vs. risks

    International Nuclear Information System (INIS)

    Wagner, H.N. Jr.

    1986-01-01

    No one has been identifiably injured by radiation within the levels set by the NCRP and ICRP in 1934. This fact and the level of natural radiation (average dose 102 millirems/year) help provide standards against which the authors can view the relative increases in exposure from manmade sources of radiation. Because one person in five in the US will die of cancer from all causes, it is impossible to detect small increases in some types of cancer from radiation. A valid assumption is that any exposure to radiation carries some possibility of harm and should be kept below the level of the expected benefits. More is known about radiation toxicity than about any other potentially toxic substances. An obstacle to progress in the use of radioactive materials in biology and medicine is an exaggerated impression by the public of the risk of radiation. Several studies indicate that the public perceives the risk of radiation to be the greatest of all societal risks and at times does not distinguish peaceful from military uses of radiation. It behooves scientists and physicians to inform the public about the benefits as well as the risks of procedures involving radiation

  4. Radiation risks and other risks

    International Nuclear Information System (INIS)

    Jansweyer, C.J.M.

    1981-01-01

    The differences in acceptance of risks of different nature (industrial, in the home, on the road, use of drugs, alcohol, tobacco, coffee or other food stuffs) by the public are compared on the basis of life expectancy values of different categories of people. The safety of radiologic work for both personnel and patients is considered in connection with the basic principles underlying the ICRP recommendations. A computation of the effective body dose equivalent for a mean medical X-ray examination and a nuclear in vivo examination is given. (Auth.)

  5. Contribution of bystander effects in radiation induced genotoxicity

    International Nuclear Information System (INIS)

    Zhou, H.; Persaud, R.; Gillispie, J.; Randers-Pehrson, G.; Hei, T.K.; Suzuki, Masao

    2005-01-01

    The controversial use of a linear, no threshold extrapolation model for low dose risk assessment is based on the accepted dogma that the deleterious effects of ionizing radiation such as mutagenesis and carcinogenesis are attributable mainly to direct damage to DNA. However, this extrapolation was challenged by the recent reports on the bystander phenomenon. The bystander effect contributes to this debate by implying that the biological effects of low doses, where not all cells are traversed by a charged particle, are amplified by the transfer of factors to un-irradiated neighbors. This interested phenomenon implies that a linear extrapolation of risks from high to low doses may underestimate rather than over estimate low dose risks. Together with some radiation-induced phenomena such as adaptive response and genomic instability, the radiobiological response at low doses is likely to be a complex interplay among many factors. (author)

  6. Space Radiation Risk Assessment

    Data.gov (United States)

    National Aeronautics and Space Administration — Project A: Integration and Review: A review of current knowledge from space radiation physics was accepted for publication in Reviews of Modern Physics (Durante and...

  7. Occupational radiation risk to radiologists

    International Nuclear Information System (INIS)

    Schuettmann, W.

    1981-01-01

    A review is given of the most important publications dealing with attempts to estimate the occupational radiation risk to radiologists by comparing data on their mortality from leukemia and other forms of cancer with respective data for other physicians who were not occupationally exposed to ionizing radiation. (author)

  8. Radiation risk education program - local

    International Nuclear Information System (INIS)

    Bushong, S.C.; Archer, B.R.

    1980-01-01

    This article points out the lack of knowledge by the general public and medical profession concerning the true risks of radiation exposure. The author describes an educational program which can be implemented at the local level to overcome this deficiency. The public must understand the enormous extent of benefit derived from radiation applications in our society

  9. Cancer risks after radiation exposures

    International Nuclear Information System (INIS)

    Voelz, G.L.

    1980-01-01

    A general overview of the effects of ionizing radiation on cancer induction is presented. The relationship between the degree of risk and absorbed dose is examined. Mortality from radiation-induced cancer in the US is estimated and percentages attributable to various sources are given

  10. Radiation risks revisited

    International Nuclear Information System (INIS)

    Ackland, L.

    1993-01-01

    The Stewart team's findings are based on previously restricted Hanford data that the U.S. Dept. of Energy began releasing in 1990 to settle a lawsuit filed by the Three Mile Island Public Health Fund. The records include those of the 7,342 workers who died before 1987 and were employed at the plant between 1944 and 1978. These workers were among more than 35,000 men and women whose radiation doses were measured by film-badge monitoring during this period. According to contemporary radiation standards, these recorded exposures were safe. But Stewart and Kneale, using a new technique to more effectively isolate occupational doses from other causes of cancer, have calculated that approximately 3 percent of the 1,732 cancer deaths in the group resulted from work-place radiation exposure

  11. Radiation risk in space exploration

    International Nuclear Information System (INIS)

    Schimmerling, W.; Wilson, J.W.; Cucinotta, F.; Kim, M.H.Y.

    1997-01-01

    Humans living and working in space are exposed to energetic charged particle radiation due to galactic cosmic rays and solar particle emissions. In order to keep the risk due to radiation exposure of astronauts below acceptable levels, the physical interaction of these particles with space structures and the biological consequences for crew members need to be understood. Such knowledge is, to a large extent, very sparse when it is available at all. Radiation limits established for space radiation protection purposes are based on extrapolation of risk from Japanese survivor data, and have been found to have large uncertainties. In space, attempting to account for large uncertainties by worst-case design results in excessive costs and accurate risk prediction is essential. It is best developed at ground-based laboratories, using particle accelerator beams to simulate individual components of space radiation. Development of mechanistic models of the action of space radiation is expected to lead to the required improvements in the accuracy of predictions, to optimization of space structures for radiation protection and, eventually, to the development of biological methods of prevention and intervention against radiation injury. (author)

  12. Sarcoma risk after radiation exposure

    Directory of Open Access Journals (Sweden)

    Berrington de Gonzalez Amy

    2012-10-01

    Full Text Available Abstract Sarcomas were one of the first solid cancers to be linked to ionizing radiation exposure. We reviewed the current evidence on this relationship, focusing particularly on the studies that had individual estimates of radiation doses. There is clear evidence of an increased risk of both bone and soft tissue sarcomas after high-dose fractionated radiation exposure (10 + Gy in childhood, and the risk increases approximately linearly in dose, at least up to 40 Gy. There are few studies available of sarcoma after radiotherapy in adulthood for cancer, but data from cancer registries and studies of treatment for benign conditions confirm that the risk of sarcoma is also increased in this age-group after fractionated high-dose exposure. New findings from the long-term follow-up of the Japanese atomic bomb survivors suggest, for the first time, that sarcomas can be induced by acute lower-doses of radiation (

  13. Competing risk theory and radiation risk assessment

    International Nuclear Information System (INIS)

    Groer, P.G.

    1980-01-01

    New statistical procedures are applied to estimate cumulative distribution functions (c.d.f.), force of mortality, and latent period for radiation-induced malignancies. It is demonstrated that correction for competing risks influences the shape of dose response curves, estimates of the latent period, and of the risk from ionizing radiations. The equivalence of the following concepts is demonstrated: force of mortality, hazard rate, and age or time specific incidence. This equivalence makes it possible to use procedures from reliability analysis and demography for radiation risk assessment. Two methods used by reliability analysts - hazard plotting and total time on test plots - are discussed in some detail and applied to characterize the hazard rate in radiation carcinogenesis. C.d.f.'s with increasing, decreasing, or constant hazard rate have different shapes and are shown to yield different dose-response curves for continuous irradiation. Absolute risk is shown to be a sound estimator only if the force of mortality is constant for the exposed and the control group. Dose-response relationships that use the absolute risk as a measure for the effect turn out to be special cases of dose-response relationships that measure the effect with cumulative incidence. (H.K.)

  14. Carcinogenesis induced by low-dose radiation

    Directory of Open Access Journals (Sweden)

    Piotrowski Igor

    2017-11-01

    Full Text Available Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is a challenging long-term side effect in oncologic patients treated with radiation. Medical sources of radiation like intensity modulated radiotherapy used in cancer treatment and computed tomography used in diagnostics, deliver very low doses of radiation to large volumes of healthy tissue, which might contribute to increased cancer rates in long surviving patients and in the general population. Research shows that because of the phenomena characteristic for low dose radiation the risk of cancer induction from exposure of healthy tissues to low dose radiation can be greater than the risk calculated from linear no-threshold model. Epidemiological data collected from radiation workers and atomic bomb survivors confirms that exposure to low dose radiation can contribute to increased cancer risk and also that the risk might correlate with the age at exposure.

  15. Ionizing radiation, genetic risks and radiation protection

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1992-01-01

    With one method of risk estimation, designed as the doubling dose method, the estimates of total genetic risk (i.e., over all generation) for a population continuously exposed at a rate of 0.01 Gy/generation of low LET irradiation are about 120 cases of Mendelian and chromosomal diseases/10 6 live births and about the same number of cases for multifactorial diseases (i.e., a total of 240 cases/10 6 ). These estimates provide the basis for risk coefficients for genetic effects estimated by ICRP (1991) in its Publication 60. These are: 1.0%/Sv for the general population (which is 40% of 240/10 6 /0.01 Gy), and 0.6%/Sv for radiation workers (which is 60% of that for the general population). The results of genetic studies carried out on the Japanese survivors of A-bombs have shown no significant adverse effects attributable to parental radiation exposures. The studies of Gardner and colleagues suggest that the risk of leukaemia in children born to male workers in the nuclear reprocessing facility in Sellafield, U.K., may be increased. However, this finding is at variance with the results from the Japanese studies and at present, does not lend itself to a simple interpretation based on radiobiological principles. In the light of recent advances in the molecular biology of naturally-occurring human Mendelian diseases and what we presently know about multifactorial diseases, arguments are advanced to support the thesis that (i) current risk estimates for Mendelian diseases may be conservative and (ii) an overall doubling dose for all adverse genetic effects may be higher than the 1 Gy currently used (i.e., the relative risks are probably lower). (author)

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

    International Nuclear Information System (INIS)

    Sugiyama, Ken-ichiro

    2013-01-01

    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)

  17. Radiation in space: risk estimates

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    2002-01-01

    The complexity of radiation environments in space makes estimation of risks more difficult than for the protection of terrestrial population. In deep space the duration of the mission, position of the solar cycle, number and size of solar particle events (SPE) and the spacecraft shielding are the major determinants of risk. In low-earth orbit missions there are the added factors of altitude and orbital inclination. Different radiation qualities such as protons and heavy ions and secondary radiations inside the spacecraft such as neutrons of various energies, have to be considered. Radiation dose rates in space are low except for short periods during very large SPEs. Risk estimation for space activities is based on the human experience of exposure to gamma rays and to a lesser extent X rays. The doses of protons, heavy ions and neutrons are adjusted to take into account the relative biological effectiveness (RBE) of the different radiation types and thus derive equivalent doses. RBE values and factors to adjust for the effect of dose rate have to be obtained from experimental data. The influence of age and gender on the cancer risk is estimated from the data from atomic bomb survivors. Because of the large number of variables the uncertainties in the probability of the effects are large. Information needed to improve the risk estimates includes: (1) risk of cancer induction by protons, heavy ions and neutrons; (2) influence of dose rate and protraction, particularly on potential tissue effects such as reduced fertility and cataracts; and (3) possible effects of heavy ions on the central nervous system. Risk cannot be eliminated and thus there must be a consensus on what level of risk is acceptable. (author)

  18. Radiation risk of diagnostical procedures

    International Nuclear Information System (INIS)

    Pohlit, W.

    1986-01-01

    The environmental radiation burden of man in Germany is about 1 mGy (Milligray) per year. This is, of course, also valid for children. Due to diagnostical procedures this burden is increased to about 1.3 mGy. The question arises wether this can be neglected, or important consequences have to be drawn. To give a clear answer, the action of ionizing radiation in living cells and in organisms is explained in detail. Many of the radiation actions at the DNA can soon be repaired by the cell, if the radiation dose was small. Some damage, however will remain irreparable for the cell and consequently leads to cell death, to mutations or to cell transformation. The number of these lesion increases or decreases linearily with radiation dose. Therefore, it must be expected that the risk of tumour induction is increased to above the normal background even by the smallest doses. This small but not negligible risk has to be compared with other risks of civilization or with other medical risks. But also the benefit and the efficacy of diagnostic procedures have to be considered. (orig./HSCH) [de

  19. Cancer and low dose responses In Vivo: implications for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Mitchel, R.E.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada)

    2006-12-15

    This paper discusses the linear no-threshold (LNT) hypothesis, risk prediction and radiation protection. The summary implications for the radiation protection system are that at low doses the conceptual basis of the present system appears to be incorrect. The belief that the current system embodies the precautionary principle and that the LNT assumption is cautious appears incorrect. The concept of dose additivity appears incorrect. Effective dose (Sievert) and the weighting factors on which it is based appear to be invalid. There may be no constant and appropriate value of DDREF for radiological protection dosimetry. The use of dose as a predictor of risk needs to be re-examined. The use of dose limits as a means of limiting risk need to be re-evaluated.

  20. Occupational risk from radiation

    International Nuclear Information System (INIS)

    Schmitz-Feuerhake, I.

    1988-01-01

    In this paper, the author shows that a real and concrete elevation of cancer cases has to be expected in all groups of occupationally irradiated perons. The risk figure one should use for mortality is 0.1% per rem of whole body dose. The mean dose registered for these persons lies well below the maximum permissible dose. In Germany there are about 0.2 rem per year in medical people and below 0.5 rem per year in the nuclear industry. But there are risk groups working in situations with typical higher exposure. In medicine, these are for example nurses working with radium implants in radiotherapy units, technicians doing cardiac catheterization and cholangiogrammes, nurses and physicians holding very young patient during X-ray investigations. In the nuclear industry there are also high level and low level working areas. Highest doses are generally delivered to personnel who are engaged from outside for revision and cleaning procedures

  1. Radiation and other risks

    International Nuclear Information System (INIS)

    Trott, K.-R.

    1991-01-01

    Examples of occupational cancer and its diagnosis drawn from history are given. These include lung cancer prevalent among cobalt miners at Schneeburg in Sascaria in the nineteenth century. The true agent causing the cancer was not identified until 1955 when it became clear that the cobalt miners of the past and uranium miners currently employed close to the old Schneeburg mines were at risk because of their exposure to the decay products of radon. Radon build up in houses in certain areas became a cause of concern although the significance of the risk has not yet been appropriately investigated. The science of epidemiology has developed new and powerful methods to detect occupational hazards, however, which are being applied to the radon issue and to other cases where the risks are much lower than in the historical examples quoted. The study of occupational cancer at the Sellafield nuclear plant in the United Kingdom is a typical example. This modern research produces results which are much less self-evident and, to the non-specialist, much more difficult to understand. Learning from the past, we may be able to avoid some errors and provide safer working conditions for the future; certainly, over the last twenty years in the UK, occupational exposure to all conceivable carcinogens has decreased considerably. (UK)

  2. Estimation of health risks from radiation exposures

    Energy Technology Data Exchange (ETDEWEB)

    Randolph, M.L.

    1983-08-01

    An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks.

  3. Estimation of health risks from radiation exposures

    International Nuclear Information System (INIS)

    Randolph, M.L.

    1983-08-01

    An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks

  4. Risks Associated with Ionizing Radiations

    International Nuclear Information System (INIS)

    Cascon, Adriana

    2009-01-01

    Medical use of ionizing radiations implies certain risks which are widely balanced by their diagnostic and therapeutic benefits. Nevertheless, knowledge about these risks and how to diagnose and prevent them minimizes their disadvantages and optimizes the quality and safety of the method. This article describes the aspects related to skin dose (nonstochastic effects), the importance of dose limit, the physiopathology of biological damage and, finally, the prevention measures. [es

  5. Quantifying Cancer Risk from Radiation.

    Science.gov (United States)

    Keil, Alexander P; Richardson, David B

    2017-12-06

    Complex statistical models fitted to data from studies of atomic bomb survivors are used to estimate the human health effects of ionizing radiation exposures. We describe and illustrate an approach to estimate population risks from ionizing radiation exposure that relaxes many assumptions about radiation-related mortality. The approach draws on developments in methods for causal inference. The results offer a different way to quantify radiation's effects and show that conventional estimates of the population burden of excess cancer at high radiation doses are driven strongly by projecting outside the range of current data. Summary results obtained using the proposed approach are similar in magnitude to those obtained using conventional methods, although estimates of radiation-related excess cancers differ for many age, sex, and dose groups. At low doses relevant to typical exposures, the strength of evidence in data is surprisingly weak. Statements regarding human health effects at low doses rely strongly on the use of modeling assumptions. © 2017 Society for Risk Analysis.

  6. Radiation risk and science education

    International Nuclear Information System (INIS)

    Eijkelhof, H.M.C.

    1996-01-01

    Almost everywhere the topic of radioactivity is taught in the physics or chemistry classes of secondary schools. The question has been raised whether the common approach of teaching this topic would contribute to a better understanding of the risks of ionising radiation: and, if the answer is negative, how to explain and improve this situation? In a Dutch research programme which took almost ten years, answers to this question have been sought by means of analyses of newspaper reports, curriculum development, consultation with radiation experts, physics textbook analysis, interviews and questionnaires with teachers and pupils, class observations and curriculum development. Th main results of this study are presented and some recommendations given for science teaching and for communication with the public in general as regards radiation risk. (author)

  7. Radiation risks and radiation protection at CRNL

    International Nuclear Information System (INIS)

    Myers, D.K.

    1986-01-01

    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

  8. Risk assessment of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Kai, Michiaki

    2012-01-01

    This commentary describes the radiation cancer risk assessed by international organizations other than ICRP, assessed for radon and for internal exposure, in the series from the aspect of radiation protection of explaining the assessments done until ICRP Pub. 103. Statistic significant increase of cancer formation is proved at higher doses than 100-200 mSv. At lower doses, with use of mathematical model, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported the death probability due to the excess lifetime risk (ELR) at 100 mSv of 0.36-0.77% for solid tumors and 0.03-0.05% for leukemia, and NRC in US, the risk of exposure-induced prevalence and death (REID) per 100 thousands persons of 800 (male)/1,310 (female) and 410/610, respectively. Both are essentially based on findings in A-bomb survivors. The assessment for Rn is described here not on dose. UK and US analyses of pooled raw data in case control studies revealed the significant increase of lung cancer formation at as low level as 100 Bq Rn/m3. Their analyses also showed the significance of smoking, which had been realized as a confounding factor in risk analysis of Rn for uranium miners. The death probability until the age of 85 y was found to be 1.2 x 10 -4 in non-smokers and 24 x 10 -4 in smokers/ Working Level Month (WLM). Increased thyroid cancer incidence has been known in Chernobyl Accident, which is realized as a result of internal exposure of radioiodine; however, the relationship between the internal dose to thyroid and its cancer prevalence resembles that in the case of external exposure. There is no certain evidence against the concept that risk of internal exposure is similar to and/or lower than, the external one although assessment of the internal exposure risk accompanies uncertainty depending on the used model and ingested dose. International Commission on Radiological Protection (ICRP) recommendations hitherto have been important and precious despite

  9. Ionizing radiation and genetic risks

    Energy Technology Data Exchange (ETDEWEB)

    Sankaranarayanan, K. [Department of Toxicogenetics, Leiden University Medical Centre, Sylvius Laboratories, Wassenaarseweg 72, 2333 AL Leiden (Netherlands)]. E-mail: sankaran@lumc.nl; Wassom, J.S. [YAHSGS, LLC, Richland, WA 99352 (United States); Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States)

    2005-10-15

    Recent estimates of genetic risks from exposure of human populations to ionizing radiation are those presented in the 2001 report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). These estimates incorporate two important concepts, namely, the following: (1) most radiation-induced mutations are DNA deletions, often encompassing multiple genes, but only a small proportion of the induced deletions is compatible with offspring viability; and (2) the viability-compatible deletions induced in germ cells are more likely to manifest themselves as multi-system developmental anomalies rather than as single gene disorders. This paper: (a) pursues these concepts further in the light of knowledge of mechanisms of origin of deletions and other rearrangements from two fields of contemporary research: repair of radiation-induced DNA double-strand breaks (DSBs) in mammalian somatic cells and human molecular genetics; and (b) extends them to deletions induced in the germ cell stages of importance for radiation risk estimation, namely, stem cell spermatogonia in males and oocytes in females. DSB repair studies in somatic cells have elucidated the roles of two mechanistically distinct pathways, namely, homologous recombination repair (HRR) that utilizes extensive sequence homology and non-homologous end-joining (NHEJ) that requires little or no homology at the junctions. A third process, single-strand annealing (SSA), which utilizes short direct repeat sequences, is considered a variant of HRR. HRR is most efficient in late S and G{sub 2} phases of the cell cycle and is a high fidelity mechanism. NHEJ operates in all cell cycle phases, but is especially important in G{sub 1}. In the context of radiation-induced DSBs, NHEJ is error-prone. SSA is also an error-prone mechanism and its role is presumably similar to that of HRR. Studies in human molecular genetics have demonstrated that the occurrence of large deletions, duplications or other

  10. Ionizing radiation and genetic risks

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.; Wassom, J.S.

    2005-01-01

    Recent estimates of genetic risks from exposure of human populations to ionizing radiation are those presented in the 2001 report of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). These estimates incorporate two important concepts, namely, the following: (1) most radiation-induced mutations are DNA deletions, often encompassing multiple genes, but only a small proportion of the induced deletions is compatible with offspring viability; and (2) the viability-compatible deletions induced in germ cells are more likely to manifest themselves as multi-system developmental anomalies rather than as single gene disorders. This paper: (a) pursues these concepts further in the light of knowledge of mechanisms of origin of deletions and other rearrangements from two fields of contemporary research: repair of radiation-induced DNA double-strand breaks (DSBs) in mammalian somatic cells and human molecular genetics; and (b) extends them to deletions induced in the germ cell stages of importance for radiation risk estimation, namely, stem cell spermatogonia in males and oocytes in females. DSB repair studies in somatic cells have elucidated the roles of two mechanistically distinct pathways, namely, homologous recombination repair (HRR) that utilizes extensive sequence homology and non-homologous end-joining (NHEJ) that requires little or no homology at the junctions. A third process, single-strand annealing (SSA), which utilizes short direct repeat sequences, is considered a variant of HRR. HRR is most efficient in late S and G 2 phases of the cell cycle and is a high fidelity mechanism. NHEJ operates in all cell cycle phases, but is especially important in G 1 . In the context of radiation-induced DSBs, NHEJ is error-prone. SSA is also an error-prone mechanism and its role is presumably similar to that of HRR. Studies in human molecular genetics have demonstrated that the occurrence of large deletions, duplications or other rearrangements

  11. The risk philosophy of radiation protection

    International Nuclear Information System (INIS)

    Lindell, B.

    1996-01-01

    The processes of risk assessment and risk evaluation are described. The assumptions behind current radiation risk assessments, which are focused on the probability of attributable death from radiation-induced cancer, are reviewed. These assessments involve projection models to take account of future cancer death in irradiated populations, the transfer of risk estimates between populations and the assumptions necessary to derive risk assessments for low radiation doses from actual observations at high doses. The paper ends with a presentation of the basic radiation protection recommendations of the International Commission on Radiological Protection (ICRP) in the context of a risk philosophy. (author)

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

    International Nuclear Information System (INIS)

    Salomaa, S.

    2006-01-01

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  14. Non-targeted effects of ionising radiation

    International Nuclear Information System (INIS)

    Belyakov, O.V.

    2008-01-01

    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.)

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

    International Nuclear Information System (INIS)

    Sisko Salomaa

    2006-01-01

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    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. Cancer risk as a radiation detriment

    International Nuclear Information System (INIS)

    Servomaa, A.; Komppa, T.; Servomaa, K.

    1992-11-01

    Potential radiation detriment means a risk of cancer or other somatic disease, genetic damage of fetal injury. Quantative information about the relation between a radiation dose and cancer risk is needed to enable decision-making in radiation protection. However, assessment of cancer risk by means of the radiation dose is controversial, as epidemiological and biological information about factors affecting the origin of cancers show that risk assessment is imprecise when the radiation dose is used as the only factor. Focusing on radiation risk estimates for breast cancer, lung cancer and leukemia, the report is based on the models given in the Beir V report, on sources of radiation exposure and the uncertainty of risk estimates. Risk estimates are assessed using the relative risk model and the cancer mortality rates in Finland. Cancer incidence and mortality rates for men and women are shown in graphs as a function of age and time. Relative risks are shown as a function of time after exposure and lifetime risks as a function of age at exposure. Uncertainty factors affecting the radiation risk are examined from the point of view of epidemiology and molecular biology. (orig.)

  18. Current features on risk perception and risk communication of radiation

    International Nuclear Information System (INIS)

    Kusama, Tomoko

    1997-01-01

    Health effects and risks of radiation and radionuclides are being misunderstood by many members of general public. Many peoples have fear and anxieties for radiation. So far, the health effects from radiation at low dose and low dose rate have not been cleared on biological aspects. Then, we have quantitatively estimated health risks of low-dose radiation on the basis of linear dose response relationship without threshold from the viewpoints of radiation protection by using both epidemiological data, such as atomic bomb survivors, and some models and assumptions. It is important for researchers and relevant persons in radiation protection to understand the process of risk estimation of radiation and to communicate an exact knowledge of radiation risks of the public members. (author)

  19. Radiation effects and radiation risks. 2. ed.

    International Nuclear Information System (INIS)

    Lengfelder, E.; Forst, D.; Feist, H.; Pratzel, H.G.

    1990-01-01

    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.) With 10 maps in appendix [de

  20. Radiation exposure and risk of death

    International Nuclear Information System (INIS)

    Hongo, Syozo

    1979-01-01

    By using the risk factor given in ICRP publication 26 and an assumption of linear relationship between risk and dose, death rate and death number which correspond to radiation dose level and collective dose level of Japanese are estimated and they are compared with vital statistics of Japanese in 1975 to get out some ideas about radiation risk relative to the risks of everyday life. (author)

  1. Radiation risk perception in Institute 'Vinca'

    International Nuclear Information System (INIS)

    Milanovic, S.; Pavlovic, S

    1999-01-01

    The necessity for research and development of risk analysis methods arise from practical needs for safety for men and environment. Relating to speed of technological development risk is implemented in modern technological achievements. Complexity of approach to the concept of risk presents the essence of risk management. Risk management means to apply risk analysis in order to risk decrease and control. Database for risk management is in technical social, economic and political area. Risk perception is a construction in the field of social psychology i.e. public opinion research. These results are of importance for the risk management. Research presented in this paper has been done on the sample of 240 examines with two basic sub samples: person working with ionizing radiation (140 of them) and persons not working with ionizing radiation (100 of them). Attitudes to risk definition risk acceptance and relation to risk consequences. (author)

  2. Risk and benefits in ionizing radiation uses

    International Nuclear Information System (INIS)

    2010-08-01

    This meeting include: A tribute to Szeinfeld, presentation software for population dose, impact on radiation protection, radiation protection hospital and population exposed workers, regulation and licensing. radiological emergencies, risk, inspection, external radiotherapy and radiation protection with photons, brachytherapy, industrial, environmental monitoring, food irradiation, nuclear power, nuclear medicine.

  3. Radiation in medicine: Origins, risks and aspirations.

    Science.gov (United States)

    Donya, Mohamed; Radford, Mark; ElGuindy, Ahmed; Firmin, David; Yacoub, Magdi H

    2014-01-01

    The use of radiation in medicine is now pervasive and routine. From their crude beginnings 100 years ago, diagnostic radiology, nuclear medicine and radiation therapy have all evolved into advanced techniques, and are regarded as essential tools across all branches and specialties of medicine. The inherent properties of ionizing radiation provide many benefits, but can also cause potential harm. Its use within medical practice thus involves an informed judgment regarding the risk/benefit ratio. This judgment requires not only medical knowledge, but also an understanding of radiation itself. This work provides a global perspective on radiation risks, exposure and mitigation strategies.

  4. Relations between radiation risks and radiation protection measuring techniques

    International Nuclear Information System (INIS)

    Herrmann, K.; Kraus, W.

    Relations between radiation risks and radiation protection measuring techniques are considered as components of the radiation risk. The influence of the exposure risk on type and extent of radiation protection measurements is discussed with regard to different measuring tasks. Based upon measuring results concerning the frequency of certain external and internal occupational exposures in the GDR, it has been shown that only a small fraction of the monitored persons are subjected to a high exposure risk. As a consequence the following recommendations are presented: occupationally exposed persons with small exposure risk should be monitored using only a long-term desimeter (for instance a thermoluminescence desimeter). In the case of internal exposure, the surface and air contamination levels should be controlled so strictly that routine measurements of internal contamination need not be performed

  5. Occupational radiation exposure risks: a review

    Energy Technology Data Exchange (ETDEWEB)

    Besar, Idris [PUSPATI, Selangor (Malaysia)

    1984-06-01

    This paper presents a review of the health risk as a result of exposure to ionizing radiation. A comparison of occupational risk among workers exposed to radiological and nonradiological harms are also presented. This comparison shows that radiation workers exposed to the current nuclear industry average of 3.4 mSv. per year are among the safest of all industry groupings.

  6. Low-level radiation risks in people

    International Nuclear Information System (INIS)

    Goloman, M.; Filjushkin, V. lgor

    1993-01-01

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

  7. Occupational radiation exposure risks: a review

    International Nuclear Information System (INIS)

    Idris Besar

    1984-01-01

    This paper presents a review of the health risk as a result of exposure to ionizing radiation. A comparison of occupational risk among workers exposed to radiological and nonradiological harms are also presented. This comparison shows that radiation workers exposed to the current nuclear industry average of 3.4 mSv. per year are among the safest of all industry groupings. (author)

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

    International Nuclear Information System (INIS)

    Matsumoto, Hideki; Hamada, Nobuyuki; Kobayashi, Yasuhiko; Takahashi, Akihisa; Ohnishi, Takeo

    2007-01-01

    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)

  9. Radiation risk and public education

    International Nuclear Information System (INIS)

    Faden, R.R.

    1983-01-01

    Two issues which deal with the public's perception of radiation hazards are discussed. The goal of public education about radiation, and the relative role of scientific and moral beliefs in public education are examined

  10. Fundamental matters on radiation risk communication

    International Nuclear Information System (INIS)

    Shinohara, Kunihiko; Nagai, Hiroyuki; Yonezawa, Rika; Ohuchi, Hiroko; Chikamoto, Kazuhiko; Taniguchi, Kazufumi; Morimoto, Eriko

    2009-01-01

    In the field of atomic energy and radiation utilization, radiation risk is considered as one of the social uneasy factors. About the perception of risks, there is a gap between experts and general public (non-experts). It is said that the general public tends to be going to judge risk from intuitive fear and a visible concrete instance whereas the experts judge it scientifically. A company, an administration or experts should disclose relating information about the risks and communicate interactively with the stakeholders to find the way to solve the problem with thinking together. This process is called 'risk communication'. The role of the expert is important on enforcement of risk communication. They should be required to explain the information on the risks with plain words to help stakeholders understand the risks properly. The Japan Health Physics Society (JHPS) is the largest academic society for radiation protection professionals in Japan, and one of its missions is supposed to convey accurate and trustworthy information about the radiation risk to the general public. The expert group on risk communication of ionizing radiation of the JHPS has worked for the purpose of summarizing the fundamental matters on radiation risk communication. 'Lecture on risk communication for the members of the JHPS.' which has been up on the JHPS web-site, and the symposium of 'For better understanding of radiation risk.' are a part of the activities. The expert group proposes that the JHPS should enlighten the members continuously for being interested in and practicing risk communication of radiation. (author)

  11. Assessment of risk from radiation sources

    International Nuclear Information System (INIS)

    Subbaratnam, T.; Madhvanath, U.; Somasundaram, S.

    1976-01-01

    Assessment of risk from exposure to ionizing radiations from man-made radiation sources and nuclear installations has to be viewed from three aspects, namely, dose-effect relationship (genetic and somatic) for humans, calculation of doses or dose-commitments to population groups, assessment of risk to radiation workers and the population at large from the current levels of exposure from nuclear industry and comparison of risk estimates with other industries in a modern society. These aspects are discussed in brief. On the basis of available data, it is shown that estimated incidence of genetic diseases and cancers due to exposure of population to radiation from nuclear industry is negligible in comparison with their natural incidence, and radiation risks to the workers in nuclear industry are much lower than the risks in other occupations. (M.G.B.)

  12. Risks associated with utilization of radiation

    International Nuclear Information System (INIS)

    Matsuoka, Satoshi; Kumazawa, Shigeru; Aoki, Yoshiro; Nakamura, Yuji; Takeda, Atsuhiko; Kusama, Tomoko; Inaba, Jiro; Tanaka, Yasumasa.

    1993-01-01

    When mankind decides action, the conveniences and the risks obtained by the action are weighed up. When socially important judgement is done, the logical discussion based on objective data is indispensable. The utilization of radiation spread from industrial circles to general public, accordingly the circumstances changed from the recognition of its risks by professionals to that by general public. The radiation exposure dose of public has increased rapidly by medical treatment. The global radioactivity contamination accompanying nuclear explosion experiment and the Chernobyl accident raised the psychological risk recognition of public. Now, the fear of the potential radioactivity which may be released from nuclear power plants and nuclear fuel cycle facilities expanded. The radiation exposure due to its utilization in recent years is mostly at the level below natural radiation. The acute radiation syndrome by whole body exposure is shown, and the effect is probabilistic. The evaluation of the risks due to radiation in the early effect, the hereditary effect and the delayed effect including canceration is explained. The risks in general human activities, the concept of risks in radiation protection, the effect of Chernobyl accident and the perception of general public on radiation risks are reported. (K.I.)

  13. New radiobiological, radiation risk and radiation protection paradigms

    International Nuclear Information System (INIS)

    Goodhead, Dudley T.

    2010-01-01

    The long-standing conventional paradigm for radiobiology has formed a logical basis for the standard paradigm for radiation risk of cancer and heritable effects and, from these paradigms, has developed the internationally applied system for radiation protection, but with many simplifications, assumptions and generalizations. A variety of additional radiobiological phenomena that do not conform to the standard paradigm for radiobiology may have potential implications for radiation risk and radiation protection. It is suggested, however, that the current state of knowledge is still insufficient for these phenomena, individually or collectively, to be formulated systematically into a new paradigm for radiobiology. Additionally, there is at present lack of direct evidence of their relevance to risk for human health, despite attractive hypotheses as to how they might be involved. Finally, it remains to be shown how incorporation of such phenomena into the paradigm for radiation protection would provide sufficient added value to offset disruption to the present widely applied system. Further research should aim for better mechanistic understanding of processes such as radiation-induced genomic instability (for all radiation types) and bystander effects (particularly for low-fluence high-LET particles) and also priority should be given to confirmation, or negation, of the relevance of the processes to human health risks from radiation.

  14. Radiation induced cancer: risk assessment and prevention

    International Nuclear Information System (INIS)

    Shore, R.E.

    1984-01-01

    A number of factors have to be considered in defining the cancer risk from ionizing radiation. These include the radiation sensitivity of the target tissue(s), the temporal pattern of risk, the shape of the dose-incidence curve, the effects of low dose rates, host susceptibility factors, and synergism with other environmental exposures. For the population as a whole the largest sources of radiation exposure are natural background radiation and medical/dental radiation. Radiation exposures in the medical field make up the largest volume of occupational exposures as well. Although new technologies offer opportunities to lower exposures, worker training, careful exposure monitoring with remedial feedback, and monitoring to prevent unnecessary radiodiagnostic procedures may be even more important means of reducing radiation exposure. Screening of irradiated populations can serve a useful preventive function, but only for those who have received very high doses

  15. Radiobiological input to radiation protection standards

    International Nuclear Information System (INIS)

    Bond, V.P.

    1981-01-01

    A brief review of the radiobiological data relevant to radiation protection standards is given. In particular the nature of the dose-response relationships for mutagenesis and carcinogenesis in animals and man is discussed with reference to the BEIR 1 1972, the NRC75, the UNSCEAR 77 and the NCRP80 Reports. It was concluded that the linear-no-threshold relationship for mutagenesis and carcinogenesis is too simple and that the relationship is best described by curves of varying slopes depending on the dose rate. By examining the data on the incidence of actual tumour systems in animals and man in relation to radiation dose, it was shown that the relationships developed in the simple Tradescantia single-cell system appear to hold widely throughout radiobiology. In developing radiation protection standards, first animal and human radiobiological data were used in determining an appropriate risk coefficient for late and genetic effects for the human being, and second an appropriate comparison of radiation and other more common risks was used as a basis for setting limits of incidence in the exposed population/individual. (U.K.)

  16. Generalized indices for radiation risk analysis

    International Nuclear Information System (INIS)

    Bykov, A.A.; Demin, V.F.

    1989-01-01

    A new approach to ensuring nuclear safety has begun forming since the early eighties. The approach based on the probabilistic safety analysis, the principles of acceptable risk, the optimization of safety measures, etc. has forced a complex of adequate quantitative methods of assessment, safety analysis and risk management to be developed. The method of radiation risk assessment and analysis hold a prominent place in the complex. National and international research and regulatory organizations ICRP, IAEA, WHO, UNSCEAR, OECD/NEA have given much attention to the development of the conceptual and methodological basis of those methods. Some resolutions of the National Commission of Radiological Protection (NCRP) and the Problem Commission on Radiation Hygiene of the USSR Ministry of Health should be also noted. Both CBA (cost benefit analysis) and other methods of radiation risk analysis and safety management use a system of natural and socio-economic indices characterizing the radiation risk or damage. There exist a number of problems associated with the introduction, justification and use of these indices. For example, the price, a, of radiation damage, or collective dose unit, is a noteworthy index. The difficulties in its qualitative and quantitative determination are still an obstacle for a wide application of CBA to the radiation risk analysis and management. During recent 10-15 years these problems have been a subject of consideration for many authors. The present paper also considers the issues of the qualitative and quantitative justification of the indices of radiation risk analysis

  17. Radiation risk - historical perspective and current issues

    Energy Technology Data Exchange (ETDEWEB)

    Kellerer, Albrecht M. [Strahlenbiologisches Institut, Ludwig-Maximilians-Universitaet, Munich, Germany and Institute for Radiation Biology, GSF-National Research Center for Environment and Health, Neuherberg (Germany)

    2002-09-01

    The assessment of radiation risk needs to be seen against the background of a historical development that has reversed the initial belief in a general beneficial effect of radiation to apprehension and fear. Numerical risk estimates are, today, based on large epidemiological studies, and the observations on the A-bomb survivors are outlined as the primary source of information. Since the epidemiological findings are obtained from relatively high radiation exposures, extrapolations are required to the much lower doses that are relevant to radiation protection. The evolution of extrapolation procedures up to current attempts at mechanistic modelling is outlined, and some of the open issues are reviewed. (author)

  18. Radiation risk - historical perspective and current issues

    International Nuclear Information System (INIS)

    Kellerer, Albrecht M.

    2002-01-01

    The assessment of radiation risk needs to be seen against the background of a historical development that has reversed the initial belief in a general beneficial effect of radiation to apprehension and fear. Numerical risk estimates are, today, based on large epidemiological studies, and the observations on the A-bomb survivors are outlined as the primary source of information. Since the epidemiological findings are obtained from relatively high radiation exposures, extrapolations are required to the much lower doses that are relevant to radiation protection. The evolution of extrapolation procedures up to current attempts at mechanistic modelling is outlined, and some of the open issues are reviewed. (author)

  19. Radiation protection. Basic concepts of ICRP

    International Nuclear Information System (INIS)

    Saito, Tsutomu; Hirata, Hideki

    2014-01-01

    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.)

  20. Characterising risk - aggregated metrics: radiation and noise

    International Nuclear Information System (INIS)

    Passchier, W.

    1998-01-01

    The characterisation of risk is an important phase in the risk assessment - risk management process. From the multitude of risk attributes a few have to be selected to obtain a risk characteristic or profile that is useful for risk management decisions and implementation of protective measures. One way to reduce the number of attributes is aggregation. In the field of radiation protection such an aggregated metric is firmly established: effective dose. For protection against environmental noise the Health Council of the Netherlands recently proposed a set of aggregated metrics for noise annoyance and sleep disturbance. The presentation will discuss similarities and differences between these two metrics and practical limitations. The effective dose has proven its usefulness in designing radiation protection measures, which are related to the level of risk associated with the radiation practice in question, given that implicit judgements on radiation induced health effects are accepted. However, as the metric does not take into account the nature of radiation practice, it is less useful in policy discussions on the benefits and harm of radiation practices. With respect to the noise exposure metric, only one effect is targeted (annoyance), and the differences between sources are explicitly taken into account. This should make the metric useful in policy discussions with respect to physical planning and siting problems. The metric proposed has only significance on a population level, and can not be used as a predictor for individual risk. (author)

  1. Radiation. Your health at risk

    International Nuclear Information System (INIS)

    This public information pamphlet gives a simple account of the nature of ionizing radiations and their effects on human health. Sources of radiation, both natural and man-made, to which the population may be exposed and the setting of exposure limits are discussed. The need is stressed for more research into the effects of low levels of exposure over long periods of time. The aims of the Radiation and Health Information Service and a list of organizers in European countries are given. A reading list is included. (UK)

  2. Relations between radiation risks and radiation protection measuring techniques

    International Nuclear Information System (INIS)

    Herrmann, K.; Kraus, W.

    1975-10-01

    'Risk of damage' and 'exposure risk' are considered as components of the radiation risk. The influence of the 'exposure risk' on type and extent of radiation protection measurements is discussed with regard to different measuring tasks. Basing upon measuring results concerning the frequency of certain external and internal occupational exposures in the GDR, it has been shown that only a small fraction of the monitored persons are subjected to a high 'exposure risk'. As a consequence the following recommendations are given for discussion: (a) occupationally exposed persons with small 'exposure risk' should be monitored using only a long-term dosimeter (for instance a thermoluminescence dosimeter), (b) in the case of internal exposure the surface and, if necessary, air contamination should be controlled so strictly that routine measurements of internal contamination need not be performed. (author)

  3. Risk analysis of external radiation therapy

    International Nuclear Information System (INIS)

    Arvidsson, Marcus

    2011-09-01

    External radiation therapy is carried out via a complex treatment process in which many different groups of staff work together. Much of the work is dependent on and in collaboration with advanced technical equipment. The purpose of the research task has been to identify a process for external radiation therapy and to identify, test and analyze a suitable method for performing risk analysis of external radiation therapy

  4. Radiation in medicine: Origins, risks and aspirations.

    OpenAIRE

    Donya, M; Radford, M; ElGuindy, A; Firmin, D; Yacoub, MH

    2014-01-01

    The use of radiation in medicine is now pervasive and routine. From their crude beginnings 100 years ago, diagnostic radiology, nuclear medicine and radiation therapy have all evolved into advanced techniques, and are regarded as essential tools across all branches and specialties of medicine. The inherent properties of ionizing radiation provide many benefits, but can also cause potential harm. Its use within medical practice thus involves an informed judgment regarding the risk/benefit rati...

  5. Radiation exposure and radiation risk of the population

    International Nuclear Information System (INIS)

    Jacobi, W.; Paretzke, H.G.; Ehling, U.H.

    1981-02-01

    The major scientifically founded results concerning the assessment of the radiation exposure and the analysis and evaluation of the radiationhazards for the population, particularly in the range of low doses, are presented. As to the risk analysis special attention is paid to the rays with low ionization density (X-, γ-, β- and electronrays). Contents: 1) Detailed survey of the results and conclusions; 2) Data on the radiation load of the population; 3) Results to epidemiological questioning on the risk of cancer; 4) Genetical radiation hazards of the population. For quantification purposes of the risk of cancer by γ-radiation the observations with the a-bomb survivors in Japan are taken as a basis, as the available dosimetrical data have to be revised. Appendices: 1) German translation of the UNSCEAR-Report (1977); 2) BEIR-Report (1980); 3) Comments from the SSK on the comparability of the risks of natural-artificial radiation exposure; 4) Comments from the SSK on the importance of synergistical influences for the radiation protection (23.9.1977). (HP) [de

  6. Epidemiological data and radiation risk estimates

    International Nuclear Information System (INIS)

    Cardis, E.

    2002-01-01

    The results of several major epidemiology studies on populations with particular exposure to ionizing radiation should become available during the first years of the 21. century. These studies are expected to provide answers to a number of questions concerning public health and radiation protection. Most of the populations concerned were accidentally exposed to radiation in ex-USSR or elsewhere or in a nuclear industrial context. The results will complete and test information on risk coming from studies among survivors of the Hiroshima and Nagasaki atomic bombs, particularly studies on the effects of low dose exposure and prolonged low-dose exposure, of different types of radiation, and environmental and host-related factors which could modify the risk of radiation-induced effects. These studies are thus important to assess the currently accepted scientific evidence on radiation protection for workers and the general population. In addition, supplementary information on radiation protection could be provided by formal comparisons and analyses combining data from populations with different types of exposure. Finally, in order to provide pertinent information for public health and radiation protection, future epidemiology studies should be targeted and designed to answer specific questions, concerning, for example, the risk for specific populations (children, patients, people with genetic predisposition). An integrated approach, combining epidemiology and studies on the mechanisms of radiation induction should provide particularly pertinent information. (author)

  7. Uncertainties in Cancer Risk Coefficients for Environmental Exposure to Radionuclides. An Uncertainty Analysis for Risk Coefficients Reported in Federal Guidance Report No. 13

    Energy Technology Data Exchange (ETDEWEB)

    Pawel, David [U.S. Environmental Protection Agency; Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; Nelson, Christopher [U.S. Environmental Protection Agency

    2007-01-01

    Federal Guidance Report No. 13 (FGR 13) provides risk coefficients for estimation of the risk of cancer due to low-level exposure to each of more than 800 radionuclides. Uncertainties in risk coefficients were quantified in FGR 13 for 33 cases (exposure to each of 11 radionuclides by each of three exposure pathways) on the basis of sensitivity analyses in which various combinations of plausible biokinetic, dosimetric, and radiation risk models were used to generate alternative risk coefficients. The present report updates the uncertainty analysis in FGR 13 for the cases of inhalation and ingestion of radionuclides and expands the analysis to all radionuclides addressed in that report. The analysis indicates that most risk coefficients for inhalation or ingestion of radionuclides are determined within a factor of 5 or less by current information. That is, application of alternate plausible biokinetic and dosimetric models and radiation risk models (based on the linear, no-threshold hypothesis with an adjustment for the dose and dose rate effectiveness factor) is unlikely to change these coefficients by more than a factor of 5. In this analysis the assessed uncertainty in the radiation risk model was found to be the main determinant of the uncertainty category for most risk coefficients, but conclusions concerning the relative contributions of risk and dose models to the total uncertainty in a risk coefficient may depend strongly on the method of assessing uncertainties in the risk model.

  8. Quantitative risk in radiation protection standards

    International Nuclear Information System (INIS)

    Bond, V.P.

    1978-01-01

    The bases for developing quantitative assessment of exposure risks in the human being, and the several problems that accompany the assessment and introduction of the risk of exposure to high and low LET radiation into radiation protection, will be evaluated. The extension of the pioneering radiation protection philosophies to the control of other hazardous agents that cannot be eliminated from the environment will be discussed, as will the serious misunderstandings and misuse of concepts and facts that have inevitably surrounded the application to one agent alone, of the protection philosophy that must in time be applied to a broad spectrum of potentially hazardous agents. (orig.) [de

  9. Radiation sources, radiation environment and risk level at Dubna

    International Nuclear Information System (INIS)

    Komochkov, M.M.

    1991-01-01

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

  10. Space Radiation and Risks to Human Health

    Science.gov (United States)

    Huff, Janice L.; Patel, Zarana S.; Simonsen, Lisa C.

    2014-01-01

    The radiation environment in space poses significant challenges to human health and is a major concern for long duration manned space missions. Outside the Earth's protective magnetosphere, astronauts are exposed to higher levels of galactic cosmic rays, whose physical characteristics are distinct from terrestrial sources of radiation such as x-rays and gamma-rays. Galactic cosmic rays consist of high energy and high mass nuclei as well as high energy protons; they impart unique biological damage as they traverse through tissue with impacts on human health that are largely unknown. The major health issues of concern are the risks of radiation carcinogenesis, acute and late decrements to the central nervous system, degenerative tissue effects such as cardiovascular disease, as well as possible acute radiation syndromes due to an unshielded exposure to a large solar particle event. The NASA Human Research Program's Space Radiation Program Element is focused on characterization and mitigation of these space radiation health risks along with understanding these risks in context of the other biological stressors found in the space environment. In this overview, we will provide a description of these health risks and the Element's research strategies to understand and mitigate these risks.

  11. Radiation as a source of risk

    International Nuclear Information System (INIS)

    Katoh, Kazuaki

    1999-01-01

    Essence and nature of ionizing radiation as a source of risk are reviewed. Following to the appeal of necessity and importance of campaign for enlightening risk management, of individual and of society, background knowledge and information helpful to the promotion and discussion are summarized, also. (author)

  12. Genetic risks of ionizing radiation

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1990-01-01

    Quantitative genetic risk estimation is made using two methods: the direct method, and the doubling dose (DD) method. The doubling dose currently used is 1 Gy for low LET, low dose, low dose rate irradiation, and is based on mouse data. Tables present the 1988 UNSCEAR estimates of genetic risk using both methods. (L.L.) (Tab.)

  13. To manage the ionizing radiations risks

    International Nuclear Information System (INIS)

    Metivier, H.; Romerio, F.

    2000-01-01

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

  14. Risks associated with radiation: General information

    International Nuclear Information System (INIS)

    Baris, D.; Pomroy, C.; Chatterjee, R.M.

    1995-07-01

    Employers have a general responsibility to explain occupational risks to their workers. This document has been prepared to assist employers in this task. Employers should inform their workers about radiation risks associated with their work by: identifying the source(s) of radiation exposure; identifying the risk of health effects due to exposure to these sources, including the risk to the embryo and foetus of pregnant female workers; explaining the relationship between regulatory dose limits and the risk of health effects; and, explaining a worker's personal dose in terms of risk. This publication provides basic information on these subjects in a form that is clear and easy to understand. For further information, a list of suggested additional reading is included at the end of the text. (author). 15 refs., 5 tabs., 3 figs

  15. Risks associated with radiation: General information

    Energy Technology Data Exchange (ETDEWEB)

    Baris, D; Pomroy, C; Chatterjee, R M

    1995-07-01

    Employers have a general responsibility to explain occupational risks to their workers. This document has been prepared to assist employers in this task. Employers should inform their workers about radiation risks associated with their work by: identifying the source(s) of radiation exposure; identifying the risk of health effects due to exposure to these sources, including the risk to the embryo and foetus of pregnant female workers; explaining the relationship between regulatory dose limits and the risk of health effects; and, explaining a worker`s personal dose in terms of risk. This publication provides basic information on these subjects in a form that is clear and easy to understand. For further information, a list of suggested additional reading is included at the end of the text. (author). 15 refs., 5 tabs., 3 figs.

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

    International Nuclear Information System (INIS)

    Radford, E.P.

    1980-01-01

    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

  17. Radiation risks for patients having X rays

    International Nuclear Information System (INIS)

    Hale, J.; Thomas, J.W.

    1985-01-01

    In addition to radiation from naturally occurring radioactive materials and cosmic rays, individuals in developed countries receive radiation doses to bone marrow and gonads from the medical diagnostic use of X rays. A brief discussion of radiation epidemiology shows that deleterious effects are low even when doses are high. The concept of acceptable risk is introduced to help evaluate the small, but still existent, risks of radiation dose. Examples of bone marrow and gonadal doses for representative X-ray examinations are presented along with the current best estimates, per unit of X-ray dose, of the induction of leukemia or of genetic harm. The risk to the patient from an examination can then be compared with the normal risk of mortality from leukemia or of the occurrence of genetic defects. The risk increase is found to be very low. The risks to unborn children from radiographic examinations are also discussed. The benefit to the patient from information obtained from the examination must be balanced against the small risks

  18. Relationship between dose and risk, and assessment of carcinogenic risks associated with low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Tubiana, M.; Aurengo, A.

    2005-01-01

    This report raises doubts on the validity of using LNT (linear no-threshold) relationship for evaluating the carcinogenic risk of low doses (< 100 mSv) and even more for very low doses (< 10 mSv). The LNT concept can be a useful pragmatic tool for assessing rules in radioprotection for doses above 10 mSv; however since it is not based on biological concepts of our current knowledge, it should not be used without precaution for assessing by extrapolation the risks associated with low and even more so, with very low doses (< 10 mSv), especially for benefit-risk assessments imposed on radiologists by the European directive 97-43. The biological mechanisms are different for doses lower than a few dozen mSv and for higher doses. The eventual risks in the dose range of radiological examinations (0.1 to 5 mSv, up to 20 mSv for some examinations) must be estimated taking into account radiobiological and experimental data. An empirical relationship which has been just validated for doses higher than 200 mSv may lead to an overestimation of risks (associated with doses one hundred fold lower), and this overestimation could discourage patients from undergoing useful examinations and introduce a bias in radioprotection measures against very low doses (< 10 mSv). Decision makers confronted with problems of radioactive waste or risk of contamination, should re-examine the methodology used for the evaluation of risks associated with very low doses and with doses delivered at a very low dose rate. This report confirms the inappropriateness of the collective dose concept to evaluate population irradiation risks

  19. Risk from fast neutron exposure

    International Nuclear Information System (INIS)

    Bond, V.P.

    1978-01-01

    The recommendations made by Rossi and Mays imply that the risk associated with the current annual dose equivalent limit of 5 rem for all radiations is unacceptably high, that this limit must be reduced by a factor of 10 or more, and that the conservative linear, no threshold hypothesis must be abandoned. It is shown here that these recommendations are not supported by the newly-analyzed neutron data, and certainly cannot be applied selectively to the annual absorbed dose limit for neutrons. In particular, the judgment that the risk of an annual exposure from 0.5 rad (5 rem) of neutrons is unacceptable high, although perhaps defensible as a personal opinion of the authors, does not follow either from the assumption of a linear-quadratic dose effect relation for low-LET radiation or from other radiobiological considerations. At issue is the level of risk that is to be considered acceptable, a question that is societal and thus not resolvable on purely technical or scientific grounds

  20. Radiation and risk in physics education

    International Nuclear Information System (INIS)

    Eijkelhof, H.M.C.

    1990-01-01

    The study reported in this thesis deals with physics education, particularly with the teaching and learning of radioactivity and ionizing radiation. It is a follow up of earlier research and development work in the Dutch Physics Curriculum Development Project (PLON) on a unit called Ionizing Radiation. The central theme of this unit was the acceptability of the risks of ionizing radiation. Preliminary evaluation of the effectiveness of the PLON-unit showed that pupils appear to have lay-ideas which seem to be resistant to change. In this study the nature and persistence of these lay-ideas have been explored and a set of recommendations have been developed for writing curriculum materials and for teaching strategies, for physics lessons in secondary high school, in order to promote thoughtful risk analysis and assessment as regards applications of ionizing radiation. (H.W.). 225 refs.; 3 figs.; 41 tabs

  1. Aircrew radiation exposure: sources-risks-measurement

    International Nuclear Information System (INIS)

    Duftschmid, K.E.

    1994-05-01

    A short review is given on the actual aircrew exposure and its sources. The resulting risks for harmful effects to the health and discuss methods for in-flight measurements of exposure is evaluated. An idea for a fairly simple and economic approach to a practical, airborne active dosimeter for the assessment of individual crew exposure is presented. The exposure of civil aircrew to cosmic radiation, should not be considered a tremendous risk to the health, there is no reason for panic. However, being significantly higher than the average exposure to radiation workers, it can certainly not be neglected. As recommended by ICRP, aircrew exposure has to be considered occupational radiation exposure and aircrews are certainly entitled to the same degree of protection, as other ground-based radiation workers have obtained by law, since long time. (author)

  2. Risk of cardiovascular disease following radiation exposure

    International Nuclear Information System (INIS)

    Trivedi, A.; Vlahovich, S.; Cornett, R.J.

    2001-01-01

    Excess radiation-induced cardiac mortalities have been reported among radiotherapy patients. Many case reports describe the occurrence of atherosclerosis following radiotherapy for Hodgkin's disease and breast cancer. Some case reports describe the cerebral infarction following radiotherapy to neck region, and of peripheral vascular disease of the lower extremities following radiotherapy to the pelvic region. The association of atomic bomb radiation and cardiovascular disease has been examined recently by incidence studies and prevalence studies of various endpoints of atherosclerosis; all endpoints indicated an increase of cardiovascular disease in the exposed group. It is almost certain that the cardiovascular disease is higher among atomic bomb survivors. However, since a heavy exposure of 10-40 Gy is delivered in radiotherapy and the bomb survivors were exposed to radiation at high dose and dose-rate, the question is whether the results can be extrapolated to individuals exposed to lower levels of radiation. Some recent epidemiological studies on occupationally exposed workers and population living near Chernobyl have provided the evidence for cardiovascular disease being a significant late effect at relatively low doses of radiation. However, the issue of non-cancer mortality from radiation is complicated by lack of adequate information on doses, and many other confounding factors (e.g., smoking habits or socio-economic status). This presentation will evaluate possible radiobiological mechanisms for radiation-induced cardiovascular disease, and will address its relevance to radiation protection management at low doses and what the impact might be on future radiation risk assessments. (authors)

  3. Radiation risk management at DOE accelerator facilities

    International Nuclear Information System (INIS)

    Dyck, O.B. van.

    1997-01-01

    The DOE accelerator contractors have been discussing among themselves and with the Department how to improve radiation safety risk management. This activity-how to assure prevention of unplanned high exposures-is separate from normal exposure management, which historically has been quite successful. The ad-hoc Committee on the Accelerator Safety Order and Guidance [CASOG], formed by the Accelerator Section of the HPS, has proposed a risk- based approach, which will be discussed. Concepts involved are risk quantification and comparison (including with non-radiation risk), passive and active (reacting) protection systems, and probabilistic analysis. Different models of risk management will be presented, and the changing regulatory environment will also be discussed

  4. Comparison of radiation and chemical risks

    International Nuclear Information System (INIS)

    Bengtsson, G.

    1988-01-01

    Injury to living cells is caused by mechanisms which in many cases are similar for radiation and chemicals. It is thus not surprising that radiation and many chemicals can cause similar biological effects, e.g. cancer, fetal injury and hereditary disease. Both radiation and chemicals are always found in our environment. One agent may strengthen or weaken the effect of another, be it radiation in combination with chemicals or one chemical with another. The implications of such synergistic or antagonistic effects are discussed. Intricate mechanisms help the body to defend itself against threats to health from radiation and chemicals, even against cancer risks. In a strategy for health, it might be worth to exploit actively these defense mechanisms, in parallel with decreasing the exposures. On particular interest are the large exposures from commonly known sources such as smoking, sun tanning and high fat contents of food. (author)

  5. Radiation risks : the ethics of health protection

    International Nuclear Information System (INIS)

    Maxey, M.N.

    1988-01-01

    Since the inception of commercial uses of nuclear technology, radiation protection standards established by regulatory agencies have reflected moral concerns based on two assumptions: (1) that the linear, zero-threshold hypothesis derives from scientific data in radiobiology which are virtually conclusive; (2) it is morally better for public health protection to assume that any radiation exposure, no matter how small, has some harmful effect which can and ought to be prevented. In the past few years these beliefs and related assumptions have received closer scrutiny, revealing hidden reasons for regulatory selection of radiation risks as objects of paramount ethical concern, with the result that greater risks to health have escaped comparison and mitigation. Based on this scrutiny this brief paper explores two questions: Are presupposed assumptions ethically justified on grounds of scientific evidence and ethical consistency? and should moral objections claiming to invalidate comparative risk assessments be accepted or rejected?

  6. Radiation in perspective applications, risks and protection

    International Nuclear Information System (INIS)

    1997-01-01

    Everyone on earth is exposed to natural radiation. Radiation produced artificially is no different, either in kind or in effect, from that originating naturally. Although radiation has many beneficial applications, throughout medicine, industry and research, it can be harmful to human beings who must be adequately protected from unnecessary or excessive exposures. For this purpose, a thorough system of international principles and standards and stringent national legislations have been put in place. Yet radiation continues to be the subject of much public fear and controversy. This clearly written report, intended for the nonspecialist reader, aims to contribute to an enlightened debate on this subject by presenting the most up-to-date and authoritative material on sources, uses and affects of radiation, and ways in which people are protected from its risks. It discusses the development of radiation protection measures, its internationally agreed principles, and also addresses social and economic issues such as ethical questions, risk perceptions, risk comparisons, public participation in decision-making and the cost of protection. (author)

  7. Radiation risks -a possible teaching topic

    International Nuclear Information System (INIS)

    Howes, R.W.

    1975-01-01

    Radiation risks has been the subject of hot debate since 1969 due in main to the energy crisis and the switch to nuclear power. Topics of this debate including; the controversy concerned with the late radiobiological effects of low level radiation, the social responsibility of modern scientists, the sometimes acrimonious discussion which has taken place over many years concerning radiation standards, and present day misgivings over the environmental aspect of the nuclear power programme, are discussed and suggestions are made of ways in which the topics could be introduced into teaching courses. (U.K.)

  8. Radiation risk due to occupational exposure

    International Nuclear Information System (INIS)

    Kargbo, A.A

    2012-04-01

    Exposure to ionizing radiation occurs in many occupations. Workers can be exposed to both natural and artificial sources of radiation. Any exposure to ionizing radiation incurs some risk, either to the individual or to the individual's progeny. This dissertation investigated the radiation risk due to occupational exposure in industrial radiography. Analysis of the reported risk estimates to occupational exposure contained in the UNSCEAR report of 2008 in industrial radiography practice was done. The causes of accidents in industrial radiography include: Lack of or inadequate regulatory control, inadequate training, failure to follow operational procedures, human error, equipment malfunction or defect, inadequate maintenance and wilful violation have been identified as primary causes of accidents. To minimise radiation risks in industrial radiography exposure devices and facilities should be designed such that there is intrinsic safety and operational safety ensured by establishing a quality assurance programme, safety culture fostered and maintained among all workers, industrial radiography is performed in compliance with approved local rules, workers engaged have appropriate qualifications and training, available safe operational procedures are followed, a means is provided for detecting incidents and accidents and an analysis of the causes and lessons learned. (author)

  9. Radiation risks and benefits: politics and morality

    International Nuclear Information System (INIS)

    Maxey, M.N.

    1983-01-01

    The bioethical framework from which moral reasoning concerning nuclear technology has been derived is both seriously flawed and conceptually inadequate. The reasons are examined and are arranged in response to three questions. First, what is the status of alleged scientific evidence from which moral conclusions about the unacceptability of man-made radiation exposures are derived. Secondly, what criticisms of risk assessment reasoning are pertinent to ethical reflection. Finally, what revisions in an ethical framework are necessary if risk estimates of low-dose radiation exposure are to be conducted properly

  10. Radiation risk assessment of reprocessed uranium

    International Nuclear Information System (INIS)

    Cardenas, Hugo R.; Perez, Aldo E.; Luna, Manuel F.; Becerra, Fabian A.

    1999-01-01

    Reprocessed uranium contains 232 U, which is not found in nature, as well as 234 U which is present in higher proportion than in natural uranium. Both isotopes modify the radiological properties of the material. The paper evaluates the increase of the internal and external radiation risk on the base of experimental data and theoretical calculations. It also suggests measures to be taken in the production of fuel elements with slightly enriched uranium.The radiation risk of reprocessed uranium is directly proportional to the content of 232 U and 234 U as well as to the aging time of the material

  11. Radiation effects, nuclear energy and comparative risks

    International Nuclear Information System (INIS)

    Gopinath, D.V.

    2007-01-01

    Nuclear energy had a promising start as an unlimited, inexpensive and environmentally benign source of energy for electricity generation. However, over the decades its growth was severely retarded due to concerns about its possible detrimental effects on the well-being of mankind and the environment. Since such concerns are essentially due to the gigantic magnitude of radioactivity and ionizing radiations associated with nuclear energy, this article starts with a comprehensive account of effects of the ionizing radiation on living systems. Quantitative description of types of radiation exposure and their varied effects is given. The origin, type and magnitude of mutagenic effects of radiation are described. The concept of radiation risk factors, basis for their evaluation and their currently accepted values are presented. With this background, origin and magnitude of radioactivity and associated ionizing radiations in nuclear reactors are presented and the elaborate measures to contain them are described. It is recognized that notwithstanding all the measures taken in the nuclear industry, certain amount of radiation exposure, however small, is inevitable and the values, based on the experience world over, are presented. Estimated health risk due to such exposures is evaluated. For a comparative analysis, risks in other options of electricity generation such as hydel and fossil-fuelled plants are described. It is seen that on an overall basis, the nuclear option is no more risky than the other commonly employed options, and is in fact, significantly less. Lastly, since every option of electricity generation entails some risk, the case of 'no addition of electricity, and its impact on the society are considered. Based on the analysis of extensive data provided by UNDP on the human development parameters for different countries in the world, it is shown that at least for developing countries, any option of addition of electricity would be far more desirable than the

  12. Emerging Radiation Health-Risk Mitigation Technologies

    International Nuclear Information System (INIS)

    Wilson, J.W.; Cucinotta, F.A.; Schimmerling, W.

    2004-01-01

    Past space missions beyond the confines of the Earth's protective magnetic field have been of short duration and protection from the effects of solar particle events was of primary concern. The extension of operational infrastructure beyond low-Earth orbit to enable routine access to more interesting regions of space will require protection from the hazards of the accumulated exposures of Galactic Cosmic Rays (GCR). There are significant challenges in providing protection from the long-duration exposure to GCR: the human risks to the exposures are highly uncertain and safety requirements places unreasonable demands in supplying sufficient shielding materials in the design. A vigorous approach to future radiation health-risk mitigation requires a triage of techniques (using biological and technical factors) and reduction of the uncertainty in radiation risk models. The present paper discusses the triage of factors for risk mitigation with associated materials issues and engineering design methods

  13. What Are the Radiation Risks from CT?

    Science.gov (United States)

    ... doses. Some scientists believe that low doses of radiation do not increase the risk of developing cancer at all, but this is a minority view. More in Medical X-ray Imaging Radiography Computed Tomography (CT) Dental Cone-beam Computed Tomography Fluoroscopy Mammography Page Last ...

  14. Risk assessment perspectives in radiation protection

    International Nuclear Information System (INIS)

    Rowe, W.D.

    1980-01-01

    Risk evaluation involves a) optimization, where collective dose is reduced by application of controls, b) justification, where benefits and costs are balanced, and c) application of dose limits. Justification may be determined in general by examining the difference between the new practice and a reference condition in the form of a diference equation. This equation is expanded to take into account other risks in addition to radiation risks. The relative potencies of some toxic chemicals are compared with those of some isotopes. Nuclear and waste disposal accidents are also considered. It is concluded that a probablistic analysis may be useful for resolving the high level radioactive waste question but not for nuclear accidents. However, in the latter case, relative risk models may provide insight into the causes of risk and where resources for reducing the risk may be best spent. (H.K.)

  15. Radiation induced cancer risk, detriment and radiation protection

    International Nuclear Information System (INIS)

    Sinclair, W.K.

    1992-01-01

    Recommendations on radiation protection limits for workers and for the public depend mainly on the total health detriment estimated to be the result of low dose ionizing radiation exposure. This detriment includes the probability of a fatal cancer, an allowance for the morbidity due to non-fatal cancer and the probability of severe hereditary effects in succeeding generations. In a population of all ages, special effects on the fetus particularly the risk of mental retardation at defined gestational ages, should also be included. Among these components of detriment after low doses, the risk of fatal cancer is the largest and most important. The estimates of fatal cancer risk used by ICRP in the 1990 recommendations were derived almost exclusively from the study of the Japanese survivors of the atomic bombs of 1945. How good are these estimates? Uncertainties associated with them, apart from those due to limitations in epidemiological observation and dosimetry, are principally those due to projection forward in time and extrapolation from high dose and dose rate to low dose and dose rate, each of which could after the estimate by a factor of 2 or so. Recent estimates of risk of cancer derived directly from low dose studies are specific only within very broad ranges of risk. Nevertheless, such studies are important as confirmation or otherwise of the estimates derived from the atomic bomb survivors. Recent U.S. British and Russian studies are examined in this light. (author)

  16. Implications of radiation risk for practical dosimetry

    International Nuclear Information System (INIS)

    Dennis, J.A.

    1984-01-01

    Radiobiological experiments with animals and cells have led to an expectation that the risks of cancer and hereditary effects are reduced at low doses and low dose rates of low LET radiation. Risk estimates derived from human exposures at high doses and dose rates usually contain an allowance for low dose effects in comparison with high dose effects, but no allowance may have been made for low dose rate effects. Although there are reasons for thinking that leukaemia risks may possibly have been underestimated, the total cancer risk assumed by ICRP for occupational exposures is reasonably realistic. For practical dosimetry the primary dose concepts and limits have to be translated into secondary quantities that are capable of practical realisation and measurement, and which will provide a stable and robust system of metrology. If the ICRP risk assumptions are approximately correct, it is extremely unlikely that epidemiological studies of occupational exposures will detect the influence of radiation. Elaboration of dosimetry and dose recording for epidemiological purposes is therefore unjustified except possibly in relation to differences between high and low LET radiations. (author)

  17. The importance of radiation risk assessment

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1979-01-01

    In its Publication 26, ICRP recommends a system of radiation dose limitation that is designed to ensure adequate protection from the harmful effects of radiation in conditions both of occupational and of environmental exposure. Clearly, however, no such system can be recommended or accepted as sufficiently safe unless the risks of the resultant exposures have been quantitatively assessed. Publication 26 reflects the increasing quantitative information that is now available on (a) carcinogenic risks of radiation in man, both from exposure of the whole body and from that of individual organs, at moderate exposures; (b) theoretical bases for inference of risk, from moderate to lower exposures; (c) genetic risks in the mouse, and inferences from such risks to those in man; (d) the dose equivalent levels at which certain non-stochastic effects may be induced. Despite a number of uncertainties, substantially improved estimates can therefore be made of the levels of safety that are likely to be achieved by observing the Commission's recommended dose limits, and the associated system of limitation of exposures to levels as low as reasonably achievable below these limits. Both for occupational exposure and for the exposure of the members of the public, these estimates are expressed in Publication 26 in terms of the risk of inducing fatal malignancies or serious hereditary ill health. These frequencies are compared with those of occupational fatalities in other industries or with accidental fatalities amongst the general public. The comparison between harm from radiation and from other agents in different industries is extended in ICRP-27 (on ''Problems Involved in Developing an Index of Harm'') in a review of the time lost through occupational diseases and non-fatal accidents, as well as from fatal diseases and accidents, so that the levels of safety achievable by the Commission's recommendations can be reviewed in the general perspective of occupational safety. (author)

  18. Mammography and radiation risk; Mammographie und Strahlenrisiko

    Energy Technology Data Exchange (ETDEWEB)

    Jung, H. [Hamburg Univ. (Germany). Inst. fuer Biophysik und Strahlenbiologie

    1998-10-01

    Breast cancer is the most frequent malignant neoplasia among women in Germany. The use of mammography as the most relevant diagnostic procedure has increased rapidly over the last decade. Radiation risks associated with mammography may be estimated from the results of numerous epidemiological studies providing risk coefficients for breast cancer in relation to age at exposure. Various calculations can be performed using the risk coefficients. For instance, a single mammography examination (bilateral, two views of each breast) of a women aged 45 may enhance the risk of developing breast cancer during her lifetime numerically from about 12% of 12.0036%. This increase in risk is lower by a factor of 3,300 as compared to the risk of developing breast cancer in the absence of radiation exposure. At the age of 40 or more, the benefit of mammography exceeds the radiation risk by a factor of about 100. At higher ages this factor increases further. Finally, the dualism of individual risk and collective risk is considered. It is shown that the individual risk of a patient, even after multiple mammography examinations, is vanishingly small. Nevertheless, the basic principle of minimising radiation exposure must be followed to keep the collective risk in the total population as low as reasonably achievable. (orig.) [Deutsch] Das Mammakarzinom ist in Deutschland die haeufigste Krebserkrankung der Frau, und entsprechend oft wird die Mammographie als das derzeit wichtigste Diagnoseverfahren eingesetzt. Zur Beurteilung des mit einer mammographischen Untersuchung verbundenen Strahlenrisikos liegen die Resultate einer groesseren Anzahl strahlenepidemiologischer Studien vor. Diese liefern den Risikokoeffizienten fuer Brustkrebs in Abhaengigkeit vom Lebensalter bei Strahlenexposition und ermoeglichen somit die Berechnung des altersabhaengigen Strahlenrisikos. Beispielsweise wird durch eine einmalige Mammographie-Untersuchung (bilateral, je zwei Aufnahmen in zwei Ebenen) bei einer 45

  19. Recent international regulations: low dose-low rate radiation protection and the demise of reason.

    Science.gov (United States)

    Okkalides, Demetrios

    2008-01-01

    The radiation protection measures suggested by the International Committee for Radiation Protection (ICRP), national regulating bodies and experts, have been becoming ever more strict despite the decrease of any information supporting the existence of the Linear no Threshold model (LNT) and of any adverse effects of Low Dose Low Rate (LDLR) irradiation. This tendency arises from the disproportionate response of human society to hazards that are currently in fashion and is unreasonable. The 1 mSv/year dose limit for the public suggested by the ICRP corresponds to a 1/18,181 detriment-adjusted cancer risk and is much lower than other hazards that are faced by modern societies such as e.g. driving and smoking which carry corresponding rate risks of 1/2,100 and 1/2,000. Even worldwide deadly work accidents rate is higher at 1/ 8,065. Such excessive safety measures against minimal risks from man made radiation sources divert resources from very real and much greater hazards. In addition they undermine research and development of radiation technology and tend to subjugate science and the quest for understanding nature to phobic practices.

  20. Risk approaches in setting radiation standards

    International Nuclear Information System (INIS)

    Whipple, C.

    1984-01-01

    This paper discusses efforts to increase the similarity of risk regulation approaches for radiation and chemical carcinogens. The risk assessment process in both cases involves the same controversy over the extrapolation from high to low doses and dose rates, and in both cases the boundaries between science and policy in risk assessment are indistinct. Three basic considerations are presented to approach policy questions: the economic efficiency of the regulatory approach, the degree of residual risk, and the technical opportunities for risk control. It is the author's opinion that if an agency can show that its standard-setting policies are consistent with those which have achieved political and judicial acceptance in other contexts, the greater the predictability of the regulatory process and the stability of this process

  1. Radiation risks to the developing nervous system

    International Nuclear Information System (INIS)

    Kriegel, H.; Schmahl, W.; Stieve, F.E.; Gerber, G.B.

    1986-01-01

    A symposium dealing with 'Radiation Risks to the Developing Nervous System' held at Neuherberg, June 18-20, 1985 was organised by the Radiation Protection Programme of the Commission of the European Communities and the Gesellschaft fuer Strahlen- und Umweltforschung mbH. The proceedings of this symposium present up-to-date information on the development of the nervous system and the modifications caused by prenatal radiation there upon. A large part of the proceedings is devoted to the consequences of prenatal irradiation in experimental animals with respect to alterations in morphology, biochemistry and behaviour, to the influence of dose, dose rate and radiation quality and to the question whether damage of the brain can arise from a synergistic action of radiation together with other agents. Since animal models for damage to the human central nervous system have inherent short-comings due to the differences in structure, complexity and development it is discussed how experimental studies could be applied to the human situation. The most recent data on persons exposed in utero at Hiroshima and Nagasaki are reviewed. A round table discussion, published in full, analyses all this information with a view to radiation protection, and defines the areas where future studies are needed. Separate abstracts were prepared for papers in these proceedings. (orig./MG)

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

    International Nuclear Information System (INIS)

    Becker, K.

    1997-01-01

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K [DIN German Standards Inst., Berlin (Germany)

    1997-11-01

    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). 16 refs.

  4. Environmental radiation standards and risk limitation

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1987-01-01

    The Environmental Protection Agency and Nuclear Regulatory Commission have established environmental radiation standards for specific practices which correspond to limits on risk to the public that vary by several orders of magnitude and often are much less than radiation risks that are essentially unregulated, e.g., risks from radon in homes. This paper discusses a proposed framework for environmental radiation standards that would improve the correspondence with limitation of risk. This framework includes the use of limits on annual effective dose equivalent averaged over a lifetime, rather than limits on dose equivalent to whole body or any organ for each year of exposure, and consideration of exposures of younger age groups as well as adults; limits on annual effective dose equivalent averaged over a lifetime no lower than 0.25 mSv (25 mrem) per practice; maintenance of all exposures as low as reasonably achievable (ALARA); and establishment of a generally applicable de minimis dose for public exposures. Implications of the proposed regulatory framework for the current system of standards for limiting public exposures are discussed. 20 refs

  5. The risk from fast neutron exposure

    International Nuclear Information System (INIS)

    Bond, V.P.

    1979-01-01

    The conclusions and recommendations made by Rossi and Mays in recent papers (Rad. Res. 71, 1, 1977; Rad. Environ. Biophys. 14, 275, 1977; Health Phys. 34, 353, 1978), based on their analysis of recent Japanese data are discussed. They imply that the risk associated with the current annual dose equivalent limit of 5 rem for all radiations is unacceptably high, that this limit must be reduced by a factor of 10 or more, and that the conservative linear, no threshold hypothesis must be abandoned. It is shown in this paper that these recommendations are not supported by the newly-analyzed neutron data, and certainly cannot be applied selectively to the annual absorbed dose limit for neutrons. In particular the judgement that the risk of an annual exposure from 0.5 rad (5 rem) of neutrons is unacceptably high, is a personal opinion of the authors, and does not necessarily follow either from the assumption of a linear-quadratic dose effect relation for low-LET radiation or from other radiobiological considerations. At issue is the level of risk that is to be considered 'acceptable', a question that is societal and thus not resolvable on purely technical or scientific grounds. (author)

  6. Radiation quality and radiation risks - some current problems

    International Nuclear Information System (INIS)

    Kellerer, A.M.; Hahn, K.

    1989-01-01

    The newly evaluated cancer mortality data of the atomic bomb survivors suggest substantially enhanced risk estimates, and the various factors that are involved in the change are considered. The enhanced risk estimates have already led to added restrictions in the dose limits for radiation workers, and there may be a further tightening of regulations in the future. The impending revision of the quality factors in radiation protection may, therefore, lead to practical difficulties, and a careful consideration of the various aspects involved in a revision is required. A liaison group of ICRU and ICRP has proposed a reformulation of the quality factor that is related not to the LET, but to the microdosimetric variably y. The relation leads to increased quality factors for neutrons, but also to a quality factor for γ rays of only 0.5. Alternatives are presented that relate the quality factor to LET and that retain γ- rays as the reference radiation. One option corresponds to different quality factors for γ rays and X-rays, the other option sets the quality factor for photons approximately equal to unity, irrespective of energy. (author)

  7. On ionising radiation and breast cancer risk

    Energy Technology Data Exchange (ETDEWEB)

    Mattson, Anders

    1999-05-01

    A cohort of 3,090 women with clinical diagnosis of benign breast disease (BBD) was studied. Of these, 1,216 were treated with radiation therapy during 1925-54 (median age 40 years). The mean dose to the breasts was 5.8 Gy (range 0-50 Gy). Among other organs the lung received the highest scattered dose (0.75 Gy; range 0.004-8.98 Gy) and the rectum the lowest (0.008 Gy; range 0-0.06 Gy). A pooled analysis of eight breast cancer incidence cohorts was done, including: tumour registry data on breast cancer incidence among women in the Life Span Study cohort of atomic bomb survivors; women in Massachusetts who received repeated chest fluoroscopic during lung collapse treatment for tuberculosis; women who received x-ray therapy for acute post-partum mastitis; women who were irradiated in infancy for enlarged thymus glands ; two Swedish cohorts of women who received radiation treatments during infancy for skin hemangioma; and the BBD cohort. Together the cohorts included almost 78,000 women (-35,000 were exposed), around 1.8 million woman-years and 1500 cases. The breast cancer incidence rate as a function of breast dose was analysed using linear-quadratic Poisson regression models. Cell-killing effects and other modifying effects were incorporated through additional log-linear terms. Additive (EAR) and multiplicative (ERR) models were compared in estimating the age-at-exposure patterns and time related excess. The carcinogenic risks associated with radiation in mammographic mass screening is evaluated. Assessment was made in terms of breast cancer mortality and years of life. Effects were related to rates not influenced by a mammographic mass screening program and based on a hypothetical cohort of 100,000 40-year old women with no history of breast cancer being followed to 100 years of age. Two radiation risk assumptions were compared. The dose-response relationship is linear with little support in data for an upward curvature at low to medium doses. The competing effect

  8. On ionising radiation and breast cancer risk

    International Nuclear Information System (INIS)

    Mattson, Anders

    1999-01-01

    A cohort of 3,090 women with clinical diagnosis of benign breast disease (BBD) was studied. Of these, 1,216 were treated with radiation therapy during 1925-54 (median age 40 years). The mean dose to the breasts was 5.8 Gy (range 0-50 Gy). Among other organs the lung received the highest scattered dose (0.75 Gy; range 0.004-8.98 Gy) and the rectum the lowest (0.008 Gy; range 0-0.06 Gy). A pooled analysis of eight breast cancer incidence cohorts was done, including: tumour registry data on breast cancer incidence among women in the Life Span Study cohort of atomic bomb survivors; women in Massachusetts who received repeated chest fluoroscopic during lung collapse treatment for tuberculosis; women who received x-ray therapy for acute post-partum mastitis; women who were irradiated in infancy for enlarged thymus glands ; two Swedish cohorts of women who received radiation treatments during infancy for skin hemangioma; and the BBD) cohort. Together the cohorts included almost 78,000 women (-35,000 were exposed), around 1.8 million woman-years and 1500 cases. The breast cancer incidence rate as a function of breast dose was analysed using linear-quadratic Poisson regression models. Cell-killing effects and other modifying effects were incorporated through additional log-linear terms. Additive (EAR) and multiplicative (ERR) models were compared in estimating the age-at-exposure patterns and time related excess. The carcinogenic risks associated with radiation in mammographic mass screening is evaluated. Assessment was made in terms of breast cancer mortality and years of life. Effects were related to rates not influenced by a mammographic mass screening program and based on a hypothetical cohort of 100,000 40-year old women with no history of breast cancer being followed to 100 years of age. Two radiation risk assumptions were compared. The dose-response relationship is linear with little support in data for an upward curvature at low to medium doses. The competing effect

  9. Quantitative risk in radiation protection standards

    International Nuclear Information System (INIS)

    Bond, V.P.

    1979-01-01

    Although the overall aim of radiobiology is to understand the biological effects of radiation, it also has the implied practical purpose of developing rational measures for the control of radiation exposure in man. The emphasis in this presentation is to show that the enormous effort expended over the years to develop quantitative dose-effect relationships in biochemical and cellular systems, animals, and human beings now seems to be paying off. The pieces appear to be falling into place, and a framework is evolving to utilize these data. Specifically, quantitative risk assessments will be discussed in terms of the cellular, animal, and human data on which they are based; their use in the development of radiation protection standards; and their present and potential impact and meaning in relation to the quantity dose equivalent and its special unit, the rem

  10. Perception of low dose radiation risks among radiation researchers in Korea.

    Science.gov (United States)

    Seong, Ki Moon; Kwon, TaeWoo; Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

    2017-01-01

    Expert's risk evaluation of radiation exposure strongly influences the public's risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts' radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual's opinions have often exacerbated the public's confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years' research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects perception of radiation exposure.

  11. Pros and cons of the revolution in radiation protection

    International Nuclear Information System (INIS)

    Latek, Stanislav

    2001-01-01

    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

  12. Radiation, cancer risk, and the new dosimetry

    International Nuclear Information System (INIS)

    Mole, R.H.

    1987-01-01

    This letter discusses revision of risk estimates in the light of the new dosimetry (DS86) and concludes that direct observation is more to be relied on than the extrapolation from A-bomb survivors' experience. X-ray treatment for ankylosing spondylitis, cervical cancer data, and figures observed from 50,000 workers occupationally exposed to radiation are used as examples. (U.K.)

  13. Sigmoidal response model for radiation risk

    International Nuclear Information System (INIS)

    Kondo, Sohei

    1995-01-01

    From epidemiologic studies, we find no measurable increase in the incidences of birth defects and cancer after low-level exposure to radiation. Based on modern understanding of the molecular basis of teratogenesis and cancer, I attempt to explain thresholds observed in atomic bomb survivors, radium painters, uranium workers and patients injected with Thorotrast. Teratogenic injury induced by doses below threshold will be completely eliminated as a result of altruistic death (apoptosis) of injured cells. Various lines of evidence obtained show that oncomutations produced in cancerous cells after exposure to radiation are of spontaneous origin and that ionizing radiation acts not as an oncomutation inducer but as a tumor promoter by induction of chronic wound-healing activity. The tissue damage induced by radiation has to be repaired by cell growth and this creates opportunity for clonal expansion of a spontaneously occurring preneoplastic cell. If the wound-healing error model is correct, there must be a threshold dose range of radiation giving no increase in cancer risk. (author)

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

    International Nuclear Information System (INIS)

    Gentner, N.E.

    1997-01-01

    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)

  15. Is radiation an appropriate model for chemical mutagenesis and carcinogenesis

    International Nuclear Information System (INIS)

    Bond, V.P.

    1982-01-01

    This chapter attempts to show why the quadratic, or ''linear quadratic,'' relationship holds for organ dose-single cell radiation effects, and to explore the extension of this relationship to chemical exposures in general. Demonstrates that although the ''αD + βD 2 relationship'' may be unexpected for normal pharmacologicalmedical dose-response relationships, a linear, no-threshold curve of this kind is expected for all stochastic-type (accidental or risk) situations with health consequences (e.g. all common accidents) including exposure to ''low-level radiation'' (LLR). Discusses the stochastic or risk approach, relevant radiobiology, and the stochastic for chemicals. Assumes that even though actual mutational rates cannot be expected to apply to the relevance of Tradescantia or any other single cell system as a predictor for mutagenesis and carcinogenesis in animals and man, the cardinal principles of genetics largely transcend species and the particular environment in which the cell is located. Concludes that with regard to LLR, the curve shapes and other relationships developed for Tradescantia would be expected to apply in principle to animal and human mutagenesis and carcinogenesis

  16. Radiation risk perception and public information

    International Nuclear Information System (INIS)

    Boggs-Mayes, C.J.

    1988-01-01

    We as Health Physicists face what, at many times, appears to be a hopeless task. The task simply stated is informing the public about the risks (or lack thereof) of radiation. Unfortunately, the public has perceived radiation risks to be much greater than they actually are. An example of this problem is shown in a paper by Arthur C. Upton. Three groups of people -- the League of Women Voters, students, and Business and Professional Club members -- were asked to rank 30 sources of risk according to their contribution to the number of deaths in the United States. Not surprisingly, they ranked nuclear power much higher and medical x-rays much lower than the actual values. In addition to the perception problem, we are faced with another hurdle: health physicists as communicators. Members of the Health Physics Society (HPS) found that the communication styles of most health physicists appear to be dissimilar to those of the general public. These authors administered the Myers-Briggs Type Indicator to the HPS Baltimore-Washington Chapter. This test, a standardized test for psychological type developed by Isabel Myers, ask questions that provide a quantitative measure of our natural preferences in four areas. Assume that you as a health physicist have the necessary skills to communicate information about radiation to the public. Health physicists do nothing with these tools. Most people involved in radiation protection do not get involved with public information activies. What I will attempt to do is heighten your interest in such activities. I will share information about public information activities in which I have been involved and give you suggestions for sources of information and materials. 2 refs., 1 tab

  17. How health risk from radiation is assessed

    International Nuclear Information System (INIS)

    Rahm-Crites, L.

    1994-07-01

    The likelihood that a dose of radiation will result in death from cancer at some future time can be estimated by multiplying the dose equivalent by a risk factor, or dose-to-risk conversion factor. Conversion factors, which are based on studies of atomic bomb survivors and others, provide approximate predictions of the health effects to be expected from a given radiological exposure. Following recommendations of the Nuclear Regulatory Commission, the Department of Energy currently uses risk conversion factors of 4 x 10 -4 (0.0004 LCFs) per person-rem for workers and 5 x 10 -4 (0.0005 LCFs) per person-rem for the general public (NRC 1991; DOE 1993). The conversion factor for general public is slightly higher than that for workers because the general public includes infants and children, who are more susceptible to cancer. The current overall death rate from cancer in the United States is between 20 and 25 percent, in other words, cancer accounts for one out of nearly every four deaths. An action affecting a population of 20,000 people, with the estimated potential to induce one latent cancer fatality, should therefore be understood as adding one death from cancer to a normally expected total of 4500. Studies dedicated to improving their ability to predict radiation health effects are constantly in progress, nationally and internationally, and risk conversion factors are periodically revised to incorporate new experimental and epidemiological information

  18. Radiation and health. Benefit and risks

    International Nuclear Information System (INIS)

    Kiefer, Juergen

    2012-01-01

    The book on radiation and health covers the following topics: The world of radiation and waves; a sight into biology; if radiation hits the body; a sight into the internal radiation diagnostics; radiation hazards; the not always beloved sun; mobile phones, microwave ovens and power poles; healing with and due to radiation; radiation and food; radiation in the environment; generation and interactions of radiation in more detail; radiation effects in the cell - closer insight; radiation doses and measurement; epidemiology and its pitfalls; the system of radiation protection radiation accidents.

  19. Hypofractionation does not increase radiation pneumonitis risk with modern conformal radiation delivery techniques

    DEFF Research Database (Denmark)

    Vogelius, Ivan R; Westerly, David C; Cannon, George M

    2010-01-01

    To study the interaction between radiation dose distribution and hypofractionated radiotherapy with respect to the risk of radiation pneumonitis (RP) estimated from normal tissue complication probability (NTCP) models.......To study the interaction between radiation dose distribution and hypofractionated radiotherapy with respect to the risk of radiation pneumonitis (RP) estimated from normal tissue complication probability (NTCP) models....

  20. Single Low-Dose Radiation Induced Regulation of Keratinocyte Differentiation in Calcium-Induced HaCaT Cells

    OpenAIRE

    Hahn, Hyung Jin; Youn, Hae Jeong; Cha, Hwa Jun; Kim, Karam; An, Sungkwan; Ahn, Kyu Joong

    2016-01-01

    Background We are continually exposed to low-dose radiation (LDR) in the range 0.1 Gy from natural sources, medical devices, nuclear energy plants, and other industrial sources of ionizing radiation. There are three models for the biological mechanism of LDR: the linear no-threshold model, the hormetic model, and the threshold model. Objective We used keratinocytes as a model system to investigate the molecular genetic effects of LDR on epidermal cell differentiation. Methods To identify kera...

  1. A practical threshold concept for simple and reasonable radiation protection

    International Nuclear Information System (INIS)

    Kaneko, Masahito

    2002-01-01

    A half century ago it was assumed for the purpose of protection that radiation risks are linearly proportional at all levels of dose. Linear No-Threshold (LNT) hypothesis has greatly contributed to the minimization of doses received by workers and members of the public, while it has brought about 'radiophobia' and unnecessary over-regulation. Now that the existence of bio-defensive mechanisms such as DNA repair, apoptosis and adaptive response are well recognized, the linearity assumption can be said 'unscientific'. Evidences increasingly imply that there are threshold effects in risk of radiation. A concept of 'practical' thresholds is proposed and the classification of 'stochastic' and 'deterministic' radiation effects should be abandoned. 'Practical' thresholds are dose levels below which induction of detectable radiogenic cancers or hereditary effects are not expected. There seems to be no evidence of deleterious health effects from radiation exposures at the current dose limits (50 mSv/y for workers and 5 mSv/y for members of the public), which have been adopted worldwide in the latter half of the 20th century. Those limits are assumed to have been set below certain 'practical' thresholds. As any workers and members of the public do not gain benefits from being exposed, excepting intentional irradiation for medical purposes, their radiation exposures should be kept below 'practical' thresholds. There is no use of 'justification' and 'optimization' (ALARA) principles, because there are no 'radiation detriments' as far as exposures are maintained below 'practical' thresholds. Accordingly the ethical issue of 'justification' to allow benefit to society to offset radiation detriments to individuals can be resolved. And also the ethical issue of 'optimization' to exchange health or safety for economical gain can be resolved. The ALARA principle should be applied to the probability (risk) of exceeding relevant dose limits instead of applying to normal exposures

  2. DNA Damage Signals and Space Radiation Risk

    Science.gov (United States)

    Cucinotta, Francis A.

    2011-01-01

    Space radiation is comprised of high-energy and charge (HZE) nuclei and protons. The initial DNA damage from HZE nuclei is qualitatively different from X-rays or gamma rays due to the clustering of damage sites which increases their complexity. Clustering of DNA damage occurs on several scales. First there is clustering of single strand breaks (SSB), double strand breaks (DSB), and base damage within a few to several hundred base pairs (bp). A second form of damage clustering occurs on the scale of a few kbp where several DSB?s may be induced by single HZE nuclei. These forms of damage clusters do not occur at low to moderate doses of X-rays or gamma rays thus presenting new challenges to DNA repair systems. We review current knowledge of differences that occur in DNA repair pathways for different types of radiation and possible relationships to mutations, chromosomal aberrations and cancer risks.

  3. Risk management of radiation therapy. Survey by north Japan radiation therapy oncology group

    International Nuclear Information System (INIS)

    Aoki, Masahiko; Abe, Yoshinao; Yamada, Shogo; Hareyama, Masato; Nakamura, Ryuji; Sugita, Tadashi; Miyano, Takashi

    2004-01-01

    A North Japan Radiation Oncology Group (NJRTOG) survey was carried out to disclose the risk management of radiation therapy. During April 2002, we sent questionnaires to radiation therapy facilities in northern Japan. There were 31 replies from 27 facilities. Many incidents and accidents were reported, including old cases. Although 60% of facilities had a risk management manual and/or risk manager, only 20% had risk management manuals for radiation therapy. Eighty five percent of radiation oncologists thought that incidents may be due to a lack of manpower. Ninety percent of radiation oncologists want to know the type of cases happened in other facilities. The risk management system is still insufficient for radiation therapy. We hope that our data will be a great help to develop risk management strategies for radiation therapy for all radiation oncologists in Japan. (author)

  4. Medical radiation exposure and genetic risks

    International Nuclear Information System (INIS)

    Baker, D.G.

    1980-01-01

    Everyone is exposed to background radiation throughout life (100 mrem/year to the gonads or 4 to 5 rem during the reproductive years). A lumbosacral series might deliver 2500 mrem to the male or 400 mrem to the female gonads. A radiologic procedure is a cost/benefit decision, and genetic risk is a part of the cost. Although cost is usually very low compared to benefit, if the procedure is unnecessary then the cost may be unacceptable. On the basis of current estimates, the doubling dose is assumed to be 40 rem (range 20 to 200) for an acute dose, and 100 rem for protracted exposure. Although there is no satisfactory way to predict the size of the risk for an individual exposed, any risk should be incentive to avoid unnecessary radiation to the gonads. Conception should be delayed for at least ten months for women and three or four months for men after irradiation of the gonads. The current incidence of genetically related diseases in the United States population is 60,000 per million live births. Based on the most conservative set of assumptions, an average gonadal dose of 1000 mrem to the whole population would increase the incidence of genetically related diseases by 0.2%

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

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    2005-01-01

    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)

  6. Radiation dose and cancer risk to out-of-field and partially in-field organs from radiotherapy for symptomatic vertebral hemangiomas

    Energy Technology Data Exchange (ETDEWEB)

    Mazonakis, Michalis, E-mail: mazonak@med.uoc.gr; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, Crete 71003 (Greece); Tzedakis, Antonis [Department of Medical Physics, University Hospital of Iraklion, Iraklion, Crete 71110 (Greece); Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, Iraklion, Crete 71110 (Greece)

    2016-04-15

    Purpose: Vertebral hemangiomas (VHs) are the most common benign tumors of the spine that may cause bone resorption. Megavoltage irradiation is usually the treatment of choice for the management of symptomatic VHs. The current study was conducted to estimate the risk for carcinogenesis from radiotherapy of this benign disease on the basis of the calculated radiation doses to healthy organs. Methods: The Monte Carlo N-particle transport code was employed to simulate the irradiation with 6 MV x-rays of a VH presented in the cervical, upper thoracic, lower thoracic, and lumbar spine. The average radiation dose (D{sub av}) received by each critical organ located outside the primarily irradiated area was calculated. Three-dimensional treatment plans were also generated for the VHs occurring at the four different sites of the spinal cord based on patients’ computed tomography data. The organ equivalent dose (OED) to each radiosensitive structure, which was partly encompassed by the applied treatment fields, was calculated with the aid of differential dose–volume histograms. The D{sub av} and the OED values were combined with a linear-no-threshold model and a nonlinear mechanistic model, respectively, to estimate the organ-, age-, and gender-specific lifetime attributable risks (LARs) for cancer development. The estimated risks were compared with the respective nominal lifetime intrinsic risks (LIRs) for the unexposed population. Results: For a standard target dose of 34 Gy, the OED varied from 0.39–5.15 Gy by the organ of interest and the irradiation site. The D{sub av} range for the out-of-field organs was 4.9 × 10{sup −4} to 0.56 Gy. The LAR for the appearance of malignancies in the partially in-field organs after radiotherapy of male and female patients was (0.08%–1.8%) and (0.09%–1.9%), respectively. These risk values were 1.5–15.5 times lower when compared to the respective LIRs. The lifetime probability for out-of-field cancer induction in irradiated

  7. Radiation dose and cancer risk to out-of-field and partially in-field organs from radiotherapy for symptomatic vertebral hemangiomas

    International Nuclear Information System (INIS)

    Mazonakis, Michalis; Damilakis, John; Tzedakis, Antonis; Lyraraki, Efrossyni

    2016-01-01

    Purpose: Vertebral hemangiomas (VHs) are the most common benign tumors of the spine that may cause bone resorption. Megavoltage irradiation is usually the treatment of choice for the management of symptomatic VHs. The current study was conducted to estimate the risk for carcinogenesis from radiotherapy of this benign disease on the basis of the calculated radiation doses to healthy organs. Methods: The Monte Carlo N-particle transport code was employed to simulate the irradiation with 6 MV x-rays of a VH presented in the cervical, upper thoracic, lower thoracic, and lumbar spine. The average radiation dose (D_a_v) received by each critical organ located outside the primarily irradiated area was calculated. Three-dimensional treatment plans were also generated for the VHs occurring at the four different sites of the spinal cord based on patients’ computed tomography data. The organ equivalent dose (OED) to each radiosensitive structure, which was partly encompassed by the applied treatment fields, was calculated with the aid of differential dose–volume histograms. The D_a_v and the OED values were combined with a linear-no-threshold model and a nonlinear mechanistic model, respectively, to estimate the organ-, age-, and gender-specific lifetime attributable risks (LARs) for cancer development. The estimated risks were compared with the respective nominal lifetime intrinsic risks (LIRs) for the unexposed population. Results: For a standard target dose of 34 Gy, the OED varied from 0.39–5.15 Gy by the organ of interest and the irradiation site. The D_a_v range for the out-of-field organs was 4.9 × 10"−"4 to 0.56 Gy. The LAR for the appearance of malignancies in the partially in-field organs after radiotherapy of male and female patients was (0.08%–1.8%) and (0.09%–1.9%), respectively. These risk values were 1.5–15.5 times lower when compared to the respective LIRs. The lifetime probability for out-of-field cancer induction in irradiated males and

  8. Radiation doses and risks from internal emitters

    International Nuclear Information System (INIS)

    Harrison, John; Day, Philip

    2008-01-01

    This review updates material prepared for the UK Government Committee Examining Radiation Risks from Internal Emitters (CERRIE) and also refers to the new recommendations of the International Commission on Radiological Protection (ICRP) and other recent developments. Two conclusions from CERRIE were that ICRP should clarify and elaborate its advice on the use of its dose quantities, equivalent and effective dose, and that more attention should be paid to uncertainties in dose and risk estimates and their implications. The new ICRP recommendations provide explanations of the calculation and intended purpose of the protection quantities, but further advice on their use would be helpful. The new recommendations refer to the importance of understanding uncertainties in estimates of dose and risk, although methods for doing this are not suggested. Dose coefficients (Sv per Bq intake) for the inhalation or ingestion of radionuclides are published as reference values without uncertainty. The primary purpose of equivalent and effective dose is to enable the summation of doses from different radionuclides and from external sources for comparison with dose limits, constraints and reference levels that relate to stochastic risks of whole-body radiation exposure. Doses are calculated using defined biokinetic and dosimetric models, including reference anatomical data for the organs and tissues of the human body. Radiation weighting factors are used to adjust for the different effectiveness of different radiation types, per unit absorbed dose (Gy), in causing stochastic effects at low doses and dose rates. Tissue weighting factors are used to take account of the contribution of individual organs and tissues to overall detriment from cancer and hereditary effects, providing a simple set of rounded values chosen on the basis of age- and sex-averaged values of relative detriment. While the definition of absorbed dose has the scientific rigour required of a basic physical quantity

  9. Ionization radiations - basis, risks and benefits

    International Nuclear Information System (INIS)

    Bodart, F.

    1991-01-01

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

  10. The biological effects of exposure to ionising radiation

    International Nuclear Information System (INIS)

    Higson, D.J.

    2016-01-01

    Scenarios for exposure to ionising radiation range from natural background radiation (chronic) to the explosions of atomic bombs (acute), with some medical, industrial and research exposures lying between these extremes. Biological responses to radiation that predominate at high doses incurred at high dose rates are different from those that predominate at low doses and low dose rates. Single doses from bomb explosions ranged up to many thousand mGy. Acute doses greater than about 1000 mGy cause acute radiation syndrome (ARS). Below this threshold, radiation has a variety of potential latent health effects: Change to the incidence of cancer is the most usual subject of attention but change to longevity may be the best overall measure because decreased incidences of non-cancer mortality have been observed to coincide with increased incidence of cancer mortality. Acute doses greater than 500 mGy cause increased risks of cancer and decreased life expectancy. For doses less than 100 mGy, beneficial overall health effects ('radiation hormesis') have been observed. At the other end of the spectrum, chronic exposure to natural radiation has occurred throughout evolution and is necessary for the normal life and health of current species. Dose rates greater than the present global average of about 2 mGy per year have either no discernible health effect or beneficial health effects up to several hundred mGy per year. It is clearly not credible that a single health effects model -- such as the linear no-threshold (LNT) model of risk estimation -- could fit all latent health effects. A more realistic model is suggested.

  11. Health risk assessment of exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Ogata, Hiromitsu

    2011-01-01

    Risk assessment is an essential process for evaluating the human health effects of exposure to ionizing radiation and for determining acceptable levels of exposure. There are two major components of radiation risk assessment: a measure of exposure level and a measure of disease occurrence. For quantitative estimation of health risks, it is important to evaluate the association between exposure and disease occurrence using epidemiological or experimental data. In these approaches, statistical risk models are used particularly for estimating cancer risks related to exposure to low levels of radiation. This paper presents a summary of basic models and methods of risk assessment for studying exposure-risk relationships. Moreover, quantitative risk estimates are subject to several sources of uncertainty due to inherent limitations in risk assessment studies. This paper also discusses the limitations of radiation risk assessment. (author)

  12. Perception of low dose radiation risks among radiation researchers in Korea

    Science.gov (United States)

    Seo, Songwon; Lee, Dalnim; Park, Sunhoo; Jin, Young Woo; Lee, Seung-Sook

    2017-01-01

    Expert’s risk evaluation of radiation exposure strongly influences the public’s risk perception. Experts can inform laypersons of significant radiation information including health knowledge based on experimental data. However, some experts’ radiation risk perception is often based on non-conclusive scientific evidence (i.e., radiation levels below 100 millisievert), which is currently under debate. Examining perception levels among experts is important for communication with the public since these individual’s opinions have often exacerbated the public’s confusion. We conducted a survey of Korean radiation researchers to investigate their perceptions of the risks associated with radiation exposure below 100 millisievert. A linear regression analysis revealed that having ≥ 11 years’ research experience was a critical factor associated with radiation risk perception, which was inversely correlated with each other. Increased opportunities to understand radiation effects at risk perception of radiation exposure. In addition, radiation researchers conceived that more scientific evidence reducing the uncertainty for radiation effects risk perception of radiation exposure. PMID:28166286

  13. Informing people about radiation risks: a review of obstacles to public understanding and effective risk communication

    International Nuclear Information System (INIS)

    Covello, V.T.

    1988-01-01

    This paper reviews the literature on informing people about radiation risks. The paper focuses on obstacles to public understanding and effective risk communication. The paper concludes with a set of guidelines for communicating information about radiation risks to the public. The paper also includes an appendix that reviews the literature on one of the most important tools for communicating information about radiation risks: risk comparisons

  14. Comments on the theory of radiation risk I Systematic outline of the theory of radiation risk

    CERN Document Server

    Neufeld, J

    1974-01-01

    Presents a systematic outline of the current theory of radiation risk. The most basic ideas of the theory can be expressed by two quantities which represent the administrative approach to radiation risk. These quantities are 'specific dose', D/sub s/, which relates to individual organs or tissues and 'overall dose', D/sub 0/, which relates to the entire human body. By taking D/sub s/ and D/sub 0/ as a starting point and by using postulational methods, two auxiliary quantities have been derived which are 'dose equivalent', D/sub e/(r), and quality factor, Q. Dose equivalent, D/sub e/(r), is a macroscopic field quantity and is, therefore, different from the ICRP defined dose equivalent, H, which is microscopic.

  15. Review of the current status of radiation risk estimates

    International Nuclear Information System (INIS)

    Charles, M.W.; Little, M.P.

    1988-10-01

    This report reviews the current status of radiation risk estimation for low linear energy transfer radiation. Recent statements by various national and international organisations regarding risk estimates are critically discussed. The recently published revised population risk estimates from the study of Japanese bomb survivors are also reviewed and used with some unpublished data from Japan to calculate risk figures for a general work force. (author)

  16. Knowledge of medical imaging radiation dose and risk among doctors

    International Nuclear Information System (INIS)

    Brown, Nicholas; Jones, Lee

    2013-01-01

    The growth of computed tomography (CT) and nuclear medicine (NM) scans has revolutionised healthcare but also greatly increased population radiation doses. Overuse of diagnostic radiation is becoming a feature of medical practice, leading to possible unnecessary radiation exposures and lifetime-risks of developing cancer. Doctors across all medical specialties and experience levels were surveyed to determine their knowledge of radiation doses and potential risks associated with some diagnostic imaging. A survey relating to knowledge and understanding of medical imaging radiation was distributed to doctors at 14 major Queensland public hospitals, as well as fellows and trainees in radiology, emergency medicine and general practice. From 608 valid responses, only 17.3% correctly estimated the radiation dose from CT scans and almost 1 in 10 incorrectly believed that CT radiation is not associated with any increased lifetime risk of developing cancer. There is a strong inverse relationship between a clinician's experience and their knowledge of CT radiation dose and risks, even among radiologists. More than a third (35.7%) of doctors incorrectly believed that typical NM imaging either does not use ionising radiation or emits doses equal to or less than a standard chest radiograph. Knowledge of CT and NM radiation doses is poor across all specialties, and there is a significant inverse relationship between experience and awareness of CT dose and risk. Despite having a poor understanding of these concepts, most doctors claim to consider them prior to requesting scans and when discussing potential risks with patients.

  17. Epidemiology Without Biology: False Paradigms, Unfounded Assumptions, and Specious Statistics in Radiation Science (with Commentaries by Inge Schmitz-Feuerhake and Christopher Busby and a Reply by the Authors)

    OpenAIRE

    Sacks, Bill; Meyerson, Gregory; Siegel, Jeffry A.

    2016-01-01

    Radiation science is dominated by a paradigm based on an assumption without empirical foundation. Known as the linear no-threshold (LNT) hypothesis, it holds that all ionizing radiation is harmful no matter how low the dose or dose rate. Epidemiological studies that claim to confirm LNT either neglect experimental and/or observational discoveries at the cellular, tissue, and organismal levels, or mention them only to distort or dismiss them. The appearance of validity in these studies rests o...

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

    Science.gov (United States)

    Giugni, U

    2012-01-01

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

  19. Information from the National Institute of Radiation Protection about radiation doses and radiation risks at x-ray screening

    International Nuclear Information System (INIS)

    1975-05-01

    This report gives a specification of data concerning radiation doses and risks at x-ray investigations of lungs. The dose estimations are principally based on measurements performed in 1974 by the National Institute of Radiation Protection. The radiation doses at x-ray screening are of that magnitude that the risk for acute radiation injuries is non-existent. At these low doses it has not either been able to prove that the radiation gives long-range effects as changes in the genes or cancer of late appearance. At considerable higher doses, more than tens of thousands of millirads, a risk of cancer appearance at a small part of all irradiated persons has been proved, based on the assumption that the cancer risk is proportional to the radiation dose. Cancer can thus occure at low radiation doses too. Because of the mass radiography in Sweden 1974 about twenty cases of cancer may appear in the future. (M.S.)

  20. Evaluating shielding effectiveness for reducing space radiation cancer risks

    International Nuclear Information System (INIS)

    Cucinotta, Francis A.; Kim, Myung-Hee Y.; Ren, Lei

    2006-01-01

    We discuss calculations of probability distribution functions (PDF) representing uncertainties in projecting fatal cancer risk from galactic cosmic rays (GCR) and solar particle events (SPE). The PDFs are used in significance tests for evaluating the effectiveness of potential radiation shielding approaches. Uncertainties in risk coefficients determined from epidemiology data, dose and dose-rate reduction factors, quality factors, and physics models of radiation environments are considered in models of cancer risk PDFs. Competing mortality risks and functional correlations in radiation quality factor uncertainties are included in the calculations. We show that the cancer risk uncertainty, defined as the ratio of the upper value of 95% confidence interval (CI) to the point estimate is about 4-fold for lunar and Mars mission risk projections. For short-stay lunar missions ( 180d) or Mars missions, GCR risks may exceed radiation risk limits that are based on acceptable levels of risk. For example, the upper 95% CI exceeding 10% fatal risk for males and females on a Mars mission. For reducing GCR cancer risks, shielding materials are marginally effective because of the penetrating nature of GCR and secondary radiation produced in tissue by relativistic particles. At the present time, polyethylene or carbon composite shielding cannot be shown to significantly reduce risk compared to aluminum shielding based on a significance test that accounts for radiobiology uncertainties in GCR risk projection

  1. Acceptable level of radiation risk and its perception

    Energy Technology Data Exchange (ETDEWEB)

    Kusama, Tomoko; Shinozaki, Motoshi; Yoshizawa, Yasuo

    1987-03-01

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

  2. Acceptable level of radiation risk and its perception

    International Nuclear Information System (INIS)

    Kusama, Tomoko; Shinozaki, Motoshi; Yoshizawa, Yasuo

    1987-01-01

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

  3. Improvement of biological decontamination, protective and repair activity against radiation injury

    International Nuclear Information System (INIS)

    Kagawa, Yasuo

    2013-01-01

    Because the protection of human subject from late radiation injury is the final goal of remediation of radioactive contamination of 137 Cs in environment, improvement of DNA-repairing ability and 137 Cs-removal from human body is important. In order to reduce environmental radioactivity in areas exceeding 5 mSv/year in Fukushima prefecture, the cost is estimated to be 118 trillion yen, and there are difficulties in finding place to store 137 Cs-contaminated soils and in 137 Cs-recontamination. The radiation damage of DNA molecule takes place stochastically following linear no threshold model (LNT), but the cancer risk and other late radiation injury from long-term low dose radiation do not follow LNT model if we improve DNA repair and the cell regeneration systems. Indirect effects of radiation damage on DNA mediated by reactive oxygen species (ROS) are prevented by vitamin C, E, carotenoids including lycopene and phytochemicals. ROS is also removed by superoxide dismutases containing Cu, Mn and Z. Direct effects of radiation damage on DNA are repaired by enzyme systems using folic acid, vitamins B 6 and B 12 . In addition, before the radiation injury, absorption of 137 Cs is prevented by taking pectin etc. and excretion of 137 Cs is accelerated by ingesting more K. Finally, early detection of cancer and its removal by detailed health check of radiation-exposed people is needed. Radiation-protecting diet developed to protect astronauts from about 1 mSv per day, will be useful for many workers of atomic power plant as well as people living in the 137 Cs-contaminated areas. (author)

  4. Neoplastic transformation in vitro by low doses of ionizing radiation: Role of adaptive response and bystander effects

    International Nuclear Information System (INIS)

    Ko, M.; Lao, X.-Y.; Kapadia, R.; Elmore, E.; Redpath, J.L.

    2006-01-01

    The shape of the dose-response curve for cancer induction by low doses of ionizing radiation is of critical importance to the assessment of cancer risk at such doses. Epidemiologic analyses are limited by sensitivity to doses typically greater than 50-100 mGy for low LET radiation. Laboratory studies allow for the examination of lower doses using cancer-relevant endpoints. One such endpoint is neoplastic transformation in vitro. It is known that this endpoint is responsive to both adaptive response and bystander effects. The relative balance of these processes is likely to play an important role in determining the shape of the dose-response curve at low doses. A factor that may influence this balance is cell density at time of irradiation. The findings reported in this paper indicate that the transformation suppressive effect of low doses previously seen following irradiation of sub-confluent cultures, and attributed to an adaptive response, is reduced for irradiated confluent cultures. However, even under these conditions designed to optimize the role of bystander effects the data do not fit a linear no-threshold model and are still consistent with the notion of a threshold dose for neoplastic transformation in vitro by low LET radiation

  5. Cancer risks following diagnostic and therapeutic radiation exposure in children

    Energy Technology Data Exchange (ETDEWEB)

    Kleinerman, Ruth A. [National Institutes of Health, Division of Cancer Epidemiology and Genetics, National Cancer Institute, EPS 7044, Rockville, MD (United States)

    2006-09-15

    The growing use of interventional and fluoroscopic imaging in children represents a tremendous benefit for the diagnosis and treatment of benign conditions. Along with the increasing use and complexity of these procedures comes concern about the cancer risk associated with ionizing radiation exposure to children. Children are considerably more sensitive to the carcinogenic effects of ionizing radiation than adults, and children have a longer life expectancy in which to express risk. Numerous epidemiologic cohort studies of childhood exposure to radiation for treatment of benign diseases have demonstrated radiation-related risks of cancer of the thyroid, breast, brain and skin, as well as leukemia. Many fewer studies have evaluated cancer risk following diagnostic radiation exposure in children. Although radiation dose for a single procedure might be low, pediatric patients often receive repeated examinations over time to evaluate their conditions, which could result in relatively high cumulative doses. Several cohort studies of girls and young women subjected to multiple diagnostic radiation exposures have been informative about increased mortality from breast cancer with increasing radiation dose, and case-control studies of childhood leukemia and postnatal diagnostic radiation exposure have suggested increased risks with an increasing number of examinations. Only two long-term follow-up studies of cancer following cardiac catheterization in childhood have been conducted, and neither reported an overall increased risk of cancer. Most cancers can be induced by radiation, and a linear dose-response has been noted for most solid cancers. Risks of radiation-related cancer are greatest for those exposed early in life, and these risks appear to persist throughout life. (orig.)

  6. Cancer risks following diagnostic and therapeutic radiation exposure in children

    International Nuclear Information System (INIS)

    Kleinerman, Ruth A.

    2006-01-01

    The growing use of interventional and fluoroscopic imaging in children represents a tremendous benefit for the diagnosis and treatment of benign conditions. Along with the increasing use and complexity of these procedures comes concern about the cancer risk associated with ionizing radiation exposure to children. Children are considerably more sensitive to the carcinogenic effects of ionizing radiation than adults, and children have a longer life expectancy in which to express risk. Numerous epidemiologic cohort studies of childhood exposure to radiation for treatment of benign diseases have demonstrated radiation-related risks of cancer of the thyroid, breast, brain and skin, as well as leukemia. Many fewer studies have evaluated cancer risk following diagnostic radiation exposure in children. Although radiation dose for a single procedure might be low, pediatric patients often receive repeated examinations over time to evaluate their conditions, which could result in relatively high cumulative doses. Several cohort studies of girls and young women subjected to multiple diagnostic radiation exposures have been informative about increased mortality from breast cancer with increasing radiation dose, and case-control studies of childhood leukemia and postnatal diagnostic radiation exposure have suggested increased risks with an increasing number of examinations. Only two long-term follow-up studies of cancer following cardiac catheterization in childhood have been conducted, and neither reported an overall increased risk of cancer. Most cancers can be induced by radiation, and a linear dose-response has been noted for most solid cancers. Risks of radiation-related cancer are greatest for those exposed early in life, and these risks appear to persist throughout life. (orig.)

  7. Radiation doses and radiation risk in foreign nuclear objects

    International Nuclear Information System (INIS)

    Tvehlov, Yu.

    2001-01-01

    Data on levels of irradiation on NPP operating in different regions of the world obtained from the data of the International Information System ISOE created by IAEA in association with the Nuclear Energetic Agency OECD are performed. Effect of commissioning new NPP, sacrifice of radiation situation at the Ignalina NPP in 1996, importance of the development and introduction of programs on perfecting of radiation protection and culture of safety are noted [ru

  8. Radiation risk from CT: implications for cancer screening.

    Science.gov (United States)

    Albert, Jeffrey M

    2013-07-01

    The cancer risks associated with patient exposure to radiation from medical imaging have become a major topic of debate. The higher doses necessary for technologies such as CT and the increasing utilization of these technologies further increase medical radiation exposure to the population. Furthermore, the use of CT for population-based cancer screening continues to be explored for common malignancies such as lung cancer and colorectal cancer. Given the known carcinogenic effects of ionizing radiation, this warrants evaluation of the balance between the benefit of early cancer detection and the risk of screening-induced malignancy. This report provides a brief review of the process of radiation carcino-genesis and the literature evaluating the risk of malignancy from CT, with a focus on the risks and benefits of CT for cancer screening. The available data suggest a small but real risk of radiation-induced malignancy from CT that could become significant at the population level with widespread use of CT-based screening. However, a growing body of literature suggests that the benefits of CT screening for lung cancer in high-risk patients and CT colonography for colorectal cancer may significantly outweigh the radiation risk. Future studies evaluating the benefits of CT screening should continue to consider potential radiation risks.

  9. Occuptional radiation exposures and thyroid cancer risk among radiologic technologists

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Eun Kyeong; Lee, Won Jin [Korea University, Seoul (Korea, Republic of); Ha, Mina [Dankook University Seoul (Korea, Republic of); Kim, Jae Young [Keimyung University, Daegu (Korea, Republic of); Jun, Jae Kwan [National Cancer Center, Seoul (Korea, Republic of); Jin, Young Won [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2016-04-15

    Medical radiation workers were among the earliest occupational groups exposed to external ionizing radiation due to their administration of a range of medical diagnostic procedures and accounted for 7.4 million worldwide in 2008. Ionizing radiation is the confirmed human carcinogen for most organ sites. The aims of the study is to evaluate the association between occupational practices including radiation exposure and thyroid cancer risk among radiologic technologists. We found no significant association between the risk of thyroid cancer and the majority of work practices among diagnostic radiation technologists in general. However workers performing fluoroscopy and interventional procedures showed increased risks although the lack of a clear exposure– response gradient makes it difficult to draw clear conclusions. Future studies with larger sample size and detailed work practices implementation are needed to clarify the role of occupational radiation work in thyroid cancer carcinogenesis.

  10. Medical interventional procedures--reducing the radiation risks

    Energy Technology Data Exchange (ETDEWEB)

    Cousins, C. E-mail: claire.cousins@addenbrookes.nhs.uk; Sharp, C

    2004-06-01

    Over the last 40 years, the number of percutaneous interventional procedures using radiation has increased significantly, with many secondary care clinicians using fluoroscopically guided techniques. Many procedures can deliver high radiation doses to patients and staff, with the potential to cause immediate and delayed radiation effects. The challenge for interventionists is to maximize benefit, whilst minimizing radiation risk to patients and staff. Non-radiologist clinicians are often inadequately trained in radiation safety and radiobiology. However, clinical governance and legislation now requires a more rigorous approach to protecting patients and staff. Protection can be ensured, and risks can be controlled, by appropriate design, procurement and commissioning of equipment; quality assurance; and optimal operational technique, backed by audit. Interventionists need knowledge and skills to reduce the risks. Appropriate training should include awareness of the potential for radiation injury, equipment operational parameters, doses measurement and recording methods and dose reduction techniques. Clinical governance requires informed consent, appropriate patient counselling and follow-up.

  11. Medical interventional procedures--reducing the radiation risks

    International Nuclear Information System (INIS)

    Cousins, C.; Sharp, C.

    2004-01-01

    Over the last 40 years, the number of percutaneous interventional procedures using radiation has increased significantly, with many secondary care clinicians using fluoroscopically guided techniques. Many procedures can deliver high radiation doses to patients and staff, with the potential to cause immediate and delayed radiation effects. The challenge for interventionists is to maximize benefit, whilst minimizing radiation risk to patients and staff. Non-radiologist clinicians are often inadequately trained in radiation safety and radiobiology. However, clinical governance and legislation now requires a more rigorous approach to protecting patients and staff. Protection can be ensured, and risks can be controlled, by appropriate design, procurement and commissioning of equipment; quality assurance; and optimal operational technique, backed by audit. Interventionists need knowledge and skills to reduce the risks. Appropriate training should include awareness of the potential for radiation injury, equipment operational parameters, doses measurement and recording methods and dose reduction techniques. Clinical governance requires informed consent, appropriate patient counselling and follow-up

  12. Occuptional radiation exposures and thyroid cancer risk among radiologic technologists

    International Nuclear Information System (INIS)

    Moon, Eun Kyeong; Lee, Won Jin; Ha, Mina; Kim, Jae Young; Jun, Jae Kwan; Jin, Young Won

    2016-01-01

    Medical radiation workers were among the earliest occupational groups exposed to external ionizing radiation due to their administration of a range of medical diagnostic procedures and accounted for 7.4 million worldwide in 2008. Ionizing radiation is the confirmed human carcinogen for most organ sites. The aims of the study is to evaluate the association between occupational practices including radiation exposure and thyroid cancer risk among radiologic technologists. We found no significant association between the risk of thyroid cancer and the majority of work practices among diagnostic radiation technologists in general. However workers performing fluoroscopy and interventional procedures showed increased risks although the lack of a clear exposure– response gradient makes it difficult to draw clear conclusions. Future studies with larger sample size and detailed work practices implementation are needed to clarify the role of occupational radiation work in thyroid cancer carcinogenesis.

  13. Natural radiation, radioactive waste and chemical risk determinants

    International Nuclear Information System (INIS)

    Christensen, T.; Mustonen, R.; Edhwall, H.; Hansen, H.; Soerensen, A.; Stranden, E.

    1990-01-01

    Doses from natural radiation to the population in the Nordic countries are summarized, and man-made modifications of the natural radiation environment are discussed. An account is given for the radiological concequences of energy concervation by reduced ventilation. Risks from possible future releases of radioactivity from final depositories of spent nuclear fuel are compared to the risks from present natural radioactivity in the environment. The possibilities for comparison between chemical and radiological risks are discussed. 104 refs., 36 figs., 47 tabs

  14. NASA Space Radiation Program Integrative Risk Model Toolkit

    Science.gov (United States)

    Kim, Myung-Hee Y.; Hu, Shaowen; Plante, Ianik; Ponomarev, Artem L.; Sandridge, Chris

    2015-01-01

    NASA Space Radiation Program Element scientists have been actively involved in development of an integrative risk models toolkit that includes models for acute radiation risk and organ dose projection (ARRBOD), NASA space radiation cancer risk projection (NSCR), hemocyte dose estimation (HemoDose), GCR event-based risk model code (GERMcode), and relativistic ion tracks (RITRACKS), NASA radiation track image (NASARTI), and the On-Line Tool for the Assessment of Radiation in Space (OLTARIS). This session will introduce the components of the risk toolkit with opportunity for hands on demonstrations. The brief descriptions of each tools are: ARRBOD for Organ dose projection and acute radiation risk calculation from exposure to solar particle event; NSCR for Projection of cancer risk from exposure to space radiation; HemoDose for retrospective dose estimation by using multi-type blood cell counts; GERMcode for basic physical and biophysical properties for an ion beam, and biophysical and radiobiological properties for a beam transport to the target in the NASA Space Radiation Laboratory beam line; RITRACKS for simulation of heavy ion and delta-ray track structure, radiation chemistry, DNA structure and DNA damage at the molecular scale; NASARTI for modeling of the effects of space radiation on human cells and tissue by incorporating a physical model of tracks, cell nucleus, and DNA damage foci with image segmentation for the automated count; and OLTARIS, an integrated tool set utilizing HZETRN (High Charge and Energy Transport) intended to help scientists and engineers study the effects of space radiation on shielding materials, electronics, and biological systems.

  15. Effective doses and standardised risk factors from paediatric diagnostic medical radiation exposures: Information for radiation risk communication

    International Nuclear Information System (INIS)

    Bibbo, Giovanni

    2018-01-01

    In the paediatric medical radiation setting, there is no consistency on the radiation risk information conveyed to the consumer (patient/carer). Each communicator may convey different information about the level of risk for the same radiation procedure, leaving the consumer confused and frustrated. There is a need to standardise risks resulting from medical radiation exposures. In this study, paediatric radiographic, fluoroscopic, CT and nuclear medicine examination data have been analysed to provide (i) effective doses and radiation induced cancer risk factors from common radiological and nuclear medicine diagnostic procedures in standardised formats, (II) awareness of the difficulties that may be encountered in communicating risks to the layperson, and (iii) an overview of the deleterious effects of ionising radiation so that the risk communicator can convey with confidence the risks resulting from medical radiation exposures. Paediatric patient dose data from general radiographic, computed tomography, fluoroscopic and nuclear medicine databases have been analysed in age groups 0 to <5 years, 5 to <10 years, 10 to <15 years and 15 to <18 years to determine standardised risk factors. Mean, minimum and maximum effective doses and the corresponding mean lifetime risks for general radiographic, fluoroscopic, CT and nuclear medicine examinations for different age groups have been calculated. For all examinations, the mean lifetime cancer induction risk is provided in three formats: statistical, fraction and category. Standardised risk factors for different radiological and nuclear medicine examinations and an overview of the deleterious effects of ionising radiation and the difficulties encountered in communicating the risks should facilitate risk communication to the patient/carer.

  16. Risks from ionizing radiation during pregnancy

    Directory of Open Access Journals (Sweden)

    mehrdad Gholami

    2007-04-01

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

  17. Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

    Science.gov (United States)

    Bednarz, Bryan; Besemer, Abigail

    2017-09-01

    The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

  18. Radiation and society: Comprehending radiation risk. V. 3. Proceedings of an international conference

    International Nuclear Information System (INIS)

    1997-01-01

    This IAEA international conference on Radiation and Society was the first major international meeting devoted to the comprehension of radiation risk, public attitude towards radiation risk and hazards encountered by the general public in contaminated areas. Volume three of the proceedings contains the speeches, ten introductory papers, summaries of the technical discussion sessions, the key note paper on uncertainties in the health impact of environmental pollutants. Refs, figs, tabs

  19. Discussions about nuclear and radiation risk information communication

    International Nuclear Information System (INIS)

    Yang Bo; Wang Erqi; Peng Xianxun

    2013-01-01

    This paper described the definition and the objective of risk communication and the development of the risk communication research. It stated that how to establish a trustworthy relationship with public and the 8 aspects that should be done for keeping the relationship. With the analysis of the cognition and the influencing of the nuclear and radiation risk, this article figured out the factors which could influence the cognition of public on nuclear and radiation risk. Moreover, it explained the principles for enhancing the efficiency of the risk communication and the specific works in each phase of the risk communication. Finally, the suggestions for the development of the risk communication of the nuclear and radiation in China had been provided. (authors)

  20. Biological effect and tumor risk of diagnostic x-rays. The ''war of the theories''; Biologische Wirkung und Tumorrisiko diagnostischer Roentgenstrahlen. Der ''Krieg der Modelle''

    Energy Technology Data Exchange (ETDEWEB)

    Selzer, E.; Hebar, A. [Medizinische Universitaet Wien, Abteilung fuer Strahlenbiologie, Klinik fuer Strahlentherapie, Wien (Austria)

    2012-10-15

    Since the introduction of ionizing radiation as a treatment and diagnostic tool in humans, scientists have been trying to estimate its side effects and potential health risks. There is now ample evidence for the principal existence of a direct relationship between higher doses and the risks of side effects. Most of the uncertainties lie in the field of low-dose effects especially with respect to the risk of cancer induction. Low-dose effects are usually of relevance in diagnostic medicine while high-dose radiation effects are typically observed after radiotherapeutic treatment for cancer or after nuclear accidents. The current state of the ''war of theories'' may be summarized as follows: one group of scientists and health regulatory officials favors the hypothesis that there is no threshold dose, i.e. the linear-no-threshold hypothesis (LNT) of radiation which can be regarded as safe. On the contrary, the critics of this hypothesis suggest that the risks of doses below 50 mSv are not measurable or even of clinical relevance and are not adequately described by a linear dose-response relationship. The aim of this article is to summarize the major unresolved issues in this field. Arguments are presented why the validity of the LNT model in the low-dose range should be regarded as at least inconsistent and is thus questionable. (orig.) [German] Seit der Einfuehrung ionisierender Strahlen als ein Mittel zur Behandlung und Diagnose beim Menschen haben Wissenschaftler versucht, ihre Nebenwirkungen und potenziellen Risiken fuer die Gesundheit einzuschaetzen. Es gibt nun ausreichende Evidenz fuer das grundsaetzliche Vorliegen einer direkten Beziehung zwischen hoeheren Dosen und Nebenwirkungsrisiken. Die meisten Unsicherheiten liegen auf dem Gebiet der Niedrigdosisforschung v. a. im Hinblick auf das Risiko der Induktion von Krebs. Niedrigdosiseffekte sind ueblicherweise von Bedeutung in der diagnostischen Medizin, waehrend Hochdosisbestrahlungseffekte

  1. Radiation risks and the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Lindell, B

    1986-01-01

    A review is given of the basic of radiation protection, including nomenclature and units and principles for protection at accidents. The consequences of the Chernobyl accident in the Soviet Union and in Sweden is described, and the recommendations and protection measures applied in Sweden are presented. In particular, the radiation levels and restrictions concerning food are discussed. (L.E.).

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

    International Nuclear Information System (INIS)

    Matsuura, T.

    1997-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Matsuura, T. [Radiation Education Forum, Minato-ku, Tokyo (Japan)

    1997-10-01

    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 50 refs., 2 tabs., 4 figs.

  4. Acceptability of risk from radiation: Application to human space flight

    International Nuclear Information System (INIS)

    1997-01-01

    This one of NASA's sponsored activities of the NCRP. In 1983, NASA asked NCRP to examine radiation risks in space and to make recommendations about career radiation limits for astronauts (with cancer considered as the principal risk). In conjunction with that effort, NCRP was asked to convene this symposium; objective is to examine the technical, strategic, and philosophical issues pertaining to acceptable risk and radiation in space. Nine papers are included together with panel discussions and a summary. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database

  5. Acceptability of risk from radiation: Application to human space flight

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-30

    This one of NASA`s sponsored activities of the NCRP. In 1983, NASA asked NCRP to examine radiation risks in space and to make recommendations about career radiation limits for astronauts (with cancer considered as the principal risk). In conjunction with that effort, NCRP was asked to convene this symposium; objective is to examine the technical, strategic, and philosophical issues pertaining to acceptable risk and radiation in space. Nine papers are included together with panel discussions and a summary. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  6. Identification of risk aversion factor for radiation workers in Korea

    International Nuclear Information System (INIS)

    Fadul, Abdulbagi; Na, Seong H.

    2016-01-01

    Radiation aversion factor reflects the degree of avoidance of radiation exposure which is considered a fundamental element in the optimization of radiation protection and a key factor in determining the real monetary value of the man-Sievert (Sv). This study provides an adjusted risk aversion factor, which was prescribed by the Korea Institute for Nuclear Safety (KINS), a regulatory body in Korea. Specifically, the Korea Hydro and Nuclear Power Co., Ltd. (KHNP) evaluated the monetary value of the man-Sv for Korean Nuclear Power Plants (NPPs) workers. This monetary value was assessed by the radiation aversion factor. Consequently, identifying the monetary value of the man-Sv in this study will enhance not only the effectiveness of optimization of radiation protection in Korea but also contribute to reduce doses to As Low As Reasonably Achievable (ALARA) when accounting for economic and societal aspects. The primary purpose of this study is to obtain the risk aversion factor for radiation workers in medical and industrial facilities in Korea. The secondary purpose is to evaluate the real monetary value of the man-Sv.These objectives will be accomplished by collecting data from surveys that consider a variety of socio-economic conditions. The value of 1.45 represents considerable avoidance of radiation risk for the majority of NDT radiographers due to familiarity and work experience with radiation hazards. On the other hand, the value 1.57 indicates that most of radiation medical practitioners, in particular, interventional radiologists have a strong will to avoid radiation risk. However, they will accept more risk with incremental salary increases. For international comparison, the concept of Purchasing Power Parity (PPP) should be adopted to obtain the alpha values in real term. Certainly, this monetary value of the man-Sv is expected to contribute effectively in optimization of radiation protection in both medical and industrial fields. The findings of this study

  7. Identification of risk aversion factor for radiation workers in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Fadul, Abdulbagi [KAIST, Daejeon (Korea, Republic of); Na, Seong H. [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-10-15

    Radiation aversion factor reflects the degree of avoidance of radiation exposure which is considered a fundamental element in the optimization of radiation protection and a key factor in determining the real monetary value of the man-Sievert (Sv). This study provides an adjusted risk aversion factor, which was prescribed by the Korea Institute for Nuclear Safety (KINS), a regulatory body in Korea. Specifically, the Korea Hydro and Nuclear Power Co., Ltd. (KHNP) evaluated the monetary value of the man-Sv for Korean Nuclear Power Plants (NPPs) workers. This monetary value was assessed by the radiation aversion factor. Consequently, identifying the monetary value of the man-Sv in this study will enhance not only the effectiveness of optimization of radiation protection in Korea but also contribute to reduce doses to As Low As Reasonably Achievable (ALARA) when accounting for economic and societal aspects. The primary purpose of this study is to obtain the risk aversion factor for radiation workers in medical and industrial facilities in Korea. The secondary purpose is to evaluate the real monetary value of the man-Sv.These objectives will be accomplished by collecting data from surveys that consider a variety of socio-economic conditions. The value of 1.45 represents considerable avoidance of radiation risk for the majority of NDT radiographers due to familiarity and work experience with radiation hazards. On the other hand, the value 1.57 indicates that most of radiation medical practitioners, in particular, interventional radiologists have a strong will to avoid radiation risk. However, they will accept more risk with incremental salary increases. For international comparison, the concept of Purchasing Power Parity (PPP) should be adopted to obtain the alpha values in real term. Certainly, this monetary value of the man-Sv is expected to contribute effectively in optimization of radiation protection in both medical and industrial fields. The findings of this study

  8. Knowledge of medical imaging radiation dose and risk among doctors.

    Science.gov (United States)

    Brown, Nicholas; Jones, Lee

    2013-02-01

    The growth of computed tomography (CT) and nuclear medicine (NM) scans has revolutionised healthcare but also greatly increased population radiation doses. Overuse of diagnostic radiation is becoming a feature of medical practice, leading to possible unnecessary radiation exposures and lifetime-risks of developing cancer. Doctors across all medical specialties and experience levels were surveyed to determine their knowledge of radiation doses and potential risks associated with some diagnostic imaging. A survey relating to knowledge and understanding of medical imaging radiation was distributed to doctors at 14 major Queensland public hospitals, as well as fellows and trainees in radiology, emergency medicine and general practice. From 608 valid responses, only 17.3% correctly estimated the radiation dose from CT scans and almost 1 in 10 incorrectly believed that CT radiation is not associated with any increased lifetime risk of developing cancer. There is a strong inverse relationship between a clinician's experience and their knowledge of CT radiation dose and risks, even among radiologists. More than a third (35.7%) of doctors incorrectly believed that typical NM imaging either does not use ionising radiation or emits doses equal to or less than a standard chest radiograph. Knowledge of CT and NM radiation doses is poor across all specialties, and there is a significant inverse relationship between experience and awareness of CT dose and risk. Despite having a poor understanding of these concepts, most doctors claim to consider them prior to requesting scans and when discussing potential risks with patients. © 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.

  9. Low dose effects of ionizing radiations in in vitro and in vivo biological systems: a multi-scale approach study

    International Nuclear Information System (INIS)

    Antoccia, A.; Berardinelli, F.; Argazzi, E.; Balata, M.; Bedogni, R.

    2011-01-01

    Long-term biological effects of low-dose radiation are little known nowadays and its carcinogenic risk is estimated on the assumption that risk remains linearly proportional to the radiation dose down to low-dose levels. However in the last 20 years this hypothesis has gradually begun to seem in contrast with a huge collection of experimental evidences, which has shown the presence of plethora of non-linear phenomena (including hypersensitivity and induced radioresistance, adaptive response, and non-targeted phenomena like bystander effect and genomic instability) occurring after low-dose irradiation. These phenomena might imply a non-linear behaviour of cancer risk curves in the low-dose region and question the validity of the Linear No-Threshold (LNT) model currently used for cancer risk assessment through extrapolation from existing high-dose data. Moreover only few information is available regarding the effects induced on cryo preserved cells by multi-year background radiation exposure, which might induce a radiation-damage accumulation, due to the inhibition of cellular repair mechanisms. In this framework, the multi-year Excalibur (Exposure effects at low doses of ionizing radiation in biological culture) experiment, funded by INFN-CNS5, has undertaken a multi-scale approach investigation on the biological effects induced in in vitro and in vivo biological systems, in culture and cryo preserved conditions, as a function of radiation quality (X/γ-rays, protons, He-4 ions of various energies) and dose, with particular emphasis on the low-dose region and non-linear phenomena, in terms of different biological endpoints.

  10. Interaction between radiation and other breast cancer risk factors

    International Nuclear Information System (INIS)

    Boice, J.D. Jr.; Stone, B.J.

    1978-01-01

    A follow-up study was conducted of 1764 women institutionalized for pulmonary tuberculosis between 1930 and 1954. Among 1047 women exposed to fluoroscopic chest X-rays during air collapse therapy of the lung, an excess of breast cancer was observed and previously reported (41 cases observed versus 23.3 expected). Among 717 comparison patients who received other treatments, no excess breast cancer risk was apparent (15 cases observed versus 14.1 expected). To determine whether breast cancer risk factors modify the carcinogenic effect of radiation, analyses were performed evaluating the interaction of radiation with indicators of breast cancer risk. The greatest radiation risk was found when radiation exposure occurred just before and during menarche. Similarly, exposures during first pregnancy appeared substantially more hazardous than exposures occurring before or after first pregnancy, suggesting that the condition of the breast at the time of pregnancy modifies the effect of radiation in such a way as to enhance the risk. Age at menopause did not appear to influence the risk of radiation exposure. Other than radiation, benign breast disease was the most significant breast cancer risk indicator. Benign breast disease was not seen to modify the effect of radiation exposure; however, excessive radiation exposure might have increased the incidence of benign breast disease, complicating the interaction analysis. Because of the uncertainty due to small-number sampling variation, these study results will require confirmation by a larger series. They do, however, suggest that stages when breast tissue undergoes high mitotic activity, e.g. menarche and pregnancy, are times of special vulnerability to the harmful effects of ionizing radiation

  11. Risks and management of radiation exposure.

    Science.gov (United States)

    Yamamoto, Loren G

    2013-09-01

    High-energy ionizing radiation is harmful. Low-level exposure sources include background, occupational, and medical diagnostics. Radiation disaster incidents include radioactive substance accidents and nuclear power plant accidents. Terrorism and international conflict could trigger intentional radiation disasters that include radiation dispersion devices (RDD) (a radioactive dirty bomb), deliberate exposure to industrial radioactive substances, nuclear power plant sabotage, and nuclear weapon detonation. Nuclear fissioning events such as nuclear power plant incidents and nuclear weapon detonation release radioactive fallout that include radioactive iodine 131, cesium 137, strontium 90, uranium, plutonium, and many other radioactive isotopes. An RDD dirty bomb is likely to spread only one radioactive substance, with the most likely substance being cesium 137. Cobalt 60 and strontium 90 are other RDD dirty bomb possibilities. In a radiation disaster, stable patients should be decontaminated to minimize further radiation exposure. Potassium iodide (KI) is useful for iodine 131 exposure. Prussian blue (ferric hexacyanoferrate) enhances the fecal excretion of cesium via ion exchange. Ca-DTPA (diethylenetriaminepentaacetic acid) and Zn-DTPA form stable ionic complexes with plutonium, americium, and curium, which are excreted in the urine. Amifostine enhances chemical and enzymatic repair of damaged DNA. Acute radiation sickness ranges in severity from mild to lethal, which can be assessed by the nausea/vomiting onset/duration, complete blood cell count findings, and neurologic symptoms.

  12. Physical and biomedical countermeasures for space radiation risk

    International Nuclear Information System (INIS)

    Durante, Marco

    2008-01-01

    Radiation exposure represents a serious hindrance for long-term interplanetary missions because of the high uncertainty on risk coefficients, and to the lack of simple countermeasures. Even if uncertainties in risk assessment will he reduced in the next few years, there is little doubt that appropriate countermeasures have to be taken to reduce the exposure or the biological damage produced by cosmic radiation. In addition, it is necessary to provide effective countermeasures against solar particle events, which can produce acute effects, even life threatening, for inadequately protected crews. Strategies that may prove to he effective in reducing exposure, or the effects of the irradiation, include shielding, administration of drugs or dietary supplements to reduce the radiation effects, crew selection based on a screening of individual radiation sensitivity. It is foreseeable that research in passive and active radiation shielding, radioprotective chemicals, and individual susceptibility will boost in the next years to provide efficient countermeasures to the space radiation threat. (orig.)

  13. Alleged radiation risks from visual display terminals

    International Nuclear Information System (INIS)

    Knave, B.G.; Bergqvist, U.O.V.

    1988-01-01

    A number of careful scientific studies have been focussed on the measurement of electromagnetic radiation or fields due to VDTs based on the cathode ray tube technique (CRT), whole limited attention has also been given acoustic radiation. The discussion as to whether work at VDTs can affect human health has been centered on different types of effects such as eye damage or discomforts, neck and shoulder discomfort, adverse reproductive outcomes, skin disorders and different stress reactions. In the present paper a short review is given of some of the alleged radiation hazards from the VDTs, mainly with emphasis on pregnancy outcome

  14. Developments in assessing carcinogenic risks from radiation

    International Nuclear Information System (INIS)

    Beebe, G.W.

    1984-01-01

    The papers in this volume have ranged widely over theoretical, experimental, and epidemiologic topics relating to radiation carcinogenesis. The multistage character of carcinogenesis, emphasis on the ease with which the initial event occurs in contrast to the infrequency of carcinogenic expression, the role of cell repair, and factors that may influence expression were major themes of the theoretical and experimental papers. The elegance of the cell transformation tool was illustrated in reviews of experimental work dealing with the exposure and environmental variables that influence radiation-induced transformation, among them the intracellular environment. Arguments were advanced for the view that more than one cell must be affected by radiation if a critical event is to occur. The relative congruence of carcinogens and clastogens was noted, and the suggestion made that the rules governing the induction of chromosomal aberrations by ionizing may apply to radiation carcinogenesis as well

  15. Risk of cancer subsequent to low-dose radiation

    International Nuclear Information System (INIS)

    Warren, S.

    1980-01-01

    The author puts low dose irradiation risks in perspective using average background radiation doses for standards. He assailed irresponsible media coverage during the height of public interest in the Three-Mile Island Reactor incident

  16. Assessment of health risks from exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Beebe, G.W.

    1982-01-01

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

  17. Biological consequences of radiation: risk factors

    International Nuclear Information System (INIS)

    1985-01-01

    This publication is a syllabus of a course on Radiation Protection. The publication offers an overview of the biological radiation effects at cellular level. For that purpose, different forms of cancers and their incidence are first discussed; structure and functioning of normal cells are considered and an introduction in genetics is given. Finally, an overview is presented of the character of tissue damage after high-dose irradiation. (G.J.P.)

  18. Social impacts induced by radiation risk in Fukushima prefecture

    International Nuclear Information System (INIS)

    Murayama, Takehiko

    2011-01-01

    An accident of Fukushima Daiichi nuclear power plant induced by an earthquake of M9.0 and subsequent tsunami gave various kinds of impacts around the plant. After reviewing arguments of local governments for low dose radiation risk, this paper analyzed social impacts by the risk in terms of a gap of emergency response between national and local governments, corruption of communities in various levels induced by plural statements for risk levels in low level radiation, and economic impacts for agricultural crops made in Fukushima prefecture. Afterwards, clues for improving the situation were discussed, which include understanding of characteristics of public perception, attitudes of experts and interactive risk communication. (author)

  19. Risks of low-level radiation - the evidence of epidemiology

    International Nuclear Information System (INIS)

    Gloag, D.

    1980-01-01

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

  20. Delineating organs at risk in radiation therapy

    CERN Document Server

    Ausili Cèfaro, Giampiero; Perez, Carlos A

    2014-01-01

    This book offers an invaluable guide to the delineation of organs at risk of toxicity in patients undergoing radiotherapy. It details the radiological anatomy of organs at risk as seen on typical radiotherapy planning CT scans.

  1. The stochastic risks of radioactive radiation - risk assessment, risk proportions, dose limits

    International Nuclear Information System (INIS)

    Lindackers, K.H.

    1990-01-01

    The latest data on the delayed injury to the a-bomb survivors of Hiroshima and Nagasaki reveal that the effects of radiation are more severe than was estimated in the past. However, the application of these data to small dose rate radiation exposure over longer periods of time leads to an overestimation of the actual risk. The future supersonic aviation schemes for altitudes within 20,000 m should include early personnel check-ups for assessment of the required protective measures. (orig./DG) [de

  2. Risk evaluation for protection of the public in radiation accidents

    International Nuclear Information System (INIS)

    1967-01-01

    Evaluation of the risk that would be involved in the exposure of the public in the event of a radiation accident requires information on the biological consequences expected of such an exposure. This report defines a range of reference doses of radiation and their corresponding risks to the public in the event of a radiation accident. The reference doses and the considerations on which they were based will be used for assessing the hazards of nuclear installations and for policy decisions by the authorities responsible for measures taken to safeguards the public in the case of a nuclear accident.

  3. Cancer risk from low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Auvinen, A.

    1997-06-01

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

  4. Cancer risk from low doses of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Auvinen, A

    1997-06-01

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

  5. Radiation risks - how low can one get

    International Nuclear Information System (INIS)

    Bunyard, P.

    1978-01-01

    The level of the maximum permissible dose of ionizing radiation at present adopted is discussed. Statistics relating to the incidence of cancer among persons exposed to radiation are considered, with special reference to workers at the USAEC Hanford plant, persons in Nagasaki or Hiroshima at or shortly after the dropping of the atomic bombs, and children whose mothers were x-rayed during pregnancy. The hearings at the Windscale official inquiry into the proposed BNFL thermal oxide reprocessing plant are also discussed. (U.K.)

  6. Ethical Aspects of Radiation Risk Management

    OpenAIRE

    Wikman-Svahn, Per

    2012-01-01

    This thesis is based on the assumption that the intersection of moral philosophy and practical risk management is a rewarding area to study. In particular, the thesis assumes that concepts, ideas, and methods that are used in moral philosophy can be of great benefit for risk analysis, but also that practices in risk regulation provide a useful testing ground for moral philosophical theories. The thesis consists of an introduction and five articles. Article I is a review article on social and ...

  7. Factors that modify risks of radiation-induced cancer

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1988-11-01

    The collective influence of biologic and physical factors that modify risks of radiation-induced cancer introduces uncertainties sufficient to deny precision of estimates of human cancer risk that can be calculated for low-dose radiation in exposed populations. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, minimum latent period, time-to-tumor recognition, and the influence of individual host (age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Other modifying factors include other carcinogens, and other biological sources (hormonal status, immune status, hereditary factors)

  8. Risk of occupational radiation-induced cataract in medical workers

    International Nuclear Information System (INIS)

    Snezana, Milacic

    2008-01-01

    The objective of this study was determination of criteria for recognition of a pre senile cataract as a professional disease in health care personnel exposed to small doses of ionizing radiation. Method: The study included 3240 health workers in medical centers of Serbia in the period 1992-2002. A total of 1560 workers were employed in the zone (group A) and 1680 out of ionizing radiation zone (group B). Among group A, two groups had been selected: 1. Group A-1: Health workers in the ionizing radiation zone who contracted lens cataract during their years of service while dosimetry could not reveal higher absorbed dose (A-1=115); 2. Group A-2: Health workers in the ionizing radiation zone with higher incidence of chromosomal aberrations and without cataract (A-2=100). Results: More significant incidence of cataract was found in group A, χ 2 =65.92; p<0.01. Radiation risk was higher in health workers in radiation zone than in others, relative risk is 4, 6. Elevated blood sugar level was found in higher percentage with health workers working in radiation zone who developed cataract. Conclusion: Low doses of radiation are not the cause of occupational cataract as individual occupational disease. X-ray radiation may be a significant cofactor of cataract in radiological technicians. (author)

  9. Stress induction in the bacteria Shewanella oneidensis and Deinococcus radiodurans in response to below-background ionizing radiation.

    Science.gov (United States)

    Castillo, Hugo; Schoderbek, Donald; Dulal, Santosh; Escobar, Gabriela; Wood, Jeffrey; Nelson, Roger; Smith, Geoffrey

    2015-01-01

    The 'Linear no-threshold' (LNT) model predicts that any amount of radiation increases the risk of organisms to accumulate negative effects. Several studies at below background radiation levels (4.5-11.4 nGy h(-1)) show decreased growth rates and an increased susceptibility to oxidative stress. The purpose of our study is to obtain molecular evidence of a stress response in Shewanella oneidensis and Deinococcus radiodurans grown at a gamma dose rate of 0.16 nGy h(-1), about 400 times less than normal background radiation. Bacteria cultures were grown at a dose rate of 0.16 or 71.3 nGy h(-1) gamma irradiation. Total RNA was extracted from samples at early-exponential and stationary phases for the rt-PCR relative quantification (radiation-deprived treatment/background radiation control) of the stress-related genes katB (catalase), recA (recombinase), oxyR (oxidative stress transcriptional regulator), lexA (SOS regulon transcriptional repressor), dnaK (heat shock protein 70) and SOA0154 (putative heavy metal efflux pump). Deprivation of normal levels of radiation caused a reduction in growth of both bacterial species, accompanied by the upregulation of katB, recA, SOA0154 genes in S. oneidensis and the upregulation of dnaK in D. radiodurans. When cells were returned to background radiation levels, growth rates recovered and the stress response dissipated. Our results indicate that below-background levels of radiation inhibited growth and elicited a stress response in two species of bacteria, contrary to the LNT model prediction.

  10. Radiation and health risks: a bioethical perspective

    International Nuclear Information System (INIS)

    Maxey, M.N.

    1983-01-01

    The author suggests that radiation and radioactivity have acquired a set of attributes that tend almost inevitably to intensify public alarm as public concern over nuclear energy and nuclear weapons has escalated. She discusses the moral argument that widespread use of radioactive substances seems tantamount to an immoral violation of human rights no matter what the benefits might be

  11. Real and perceived risks of medical radiation exposure

    International Nuclear Information System (INIS)

    Hendee, W.R.

    1983-01-01

    After considering all the evidence related to the health effects of exposure to low levels of radiation, it is apparent that the risk is immeasurably small to any single person in a population exposed to small amounts of radiation. However, multiplying this immeasurably small estimate of risk by very large populations yields numbers that seem to imply that significant health effects (cancer, malformations, genetic effects) occur following exposure to small quantities of radiation. Although many advisory groups have cautioned against this procedure and conclusion, both continue to be used by some scientists and political action groups. In a public opinion poll conducted by Decision Research, Inc. of Eugene, Oregon, three groups were asked to rank the relative risks of various societal activities. Two of the three groups ranked nuclear power as the most hazardous of all societal activities, with a risk factor greater than that for smoking, automobiles, handguns and alcohol. Actually, nuclear power is the least hazardous of all 30 of the activities included in the poll. It is a conservative posture and probably a wise course of action to assume that exposure to any amount of radiation carries with it some element of risk. For example, requests for x-ray studies and nuclear medicine procedures should always be accompanied by an appreciation of the possibility of risk to the patient and to radiological personnel. At the same time, this element of risk should be placed in a realistic perspective by comparing it with other risks we assume every day

  12. Risky business: challenges and successes in military radiation risk communication.

    Science.gov (United States)

    Melanson, Mark A; Geckle, Lori S; Davidson, Bethney A

    2012-01-01

    Given the general public's overall lack of knowledge about radiation and their heightened fear of its harmful effects, effective communication of radiation risks is often difficult. This is especially true when it comes to communicating the radiation risks stemming from military operations. Part of this difficulty stems from a lingering distrust of the military that harkens back to the controversy surrounding Veteran exposures to Agent Orange during the Vietnam War along with the often classified nature of many military operations. Additionally, there are unique military exposure scenarios, such as the use of nuclear weapons and combat use of depleted uranium as antiarmor munitions that are not found in the civilian sector. Also, the large, diverse nature of the military makes consistent risk communication across the vast and widespread organization very difficult. This manuscript highlights and discusses both the common and the distinctive challenges of effectively communicating military radiation risks, to include communicating through the media. The paper also introduces the Army's Health Risk Communication Program and its role in assisting in effective risk communication efforts. The authors draw on their extensive collective experience to share 3 risk communication success stories that were accomplished through the innovative use of a matrixed, team approach that combines both health physics and risk communication expertise.

  13. Radiation risk estimation based on measurement error models

    CERN Document Server

    Masiuk, Sergii; Shklyar, Sergiy; Chepurny, Mykola; Likhtarov, Illya

    2017-01-01

    This monograph discusses statistics and risk estimates applied to radiation damage under the presence of measurement errors. The first part covers nonlinear measurement error models, with a particular emphasis on efficiency of regression parameter estimators. In the second part, risk estimation in models with measurement errors is considered. Efficiency of the methods presented is verified using data from radio-epidemiological studies.

  14. Health effects of low level exposure to ionizing radiation: origin and development of a controversy

    International Nuclear Information System (INIS)

    Masse, Roland

    2014-06-01

    Health hazard assessment related to doses of ionizing radiation lower than 100-200 mSv is a matter of controversy, and more acutely when choosing transition towards a new energetic paradigm. Neither epidemiological nor experimental data can be used to determine the shape of the dose-effect relationship from 0 to 100 mSv. Recently, however, long term follow-up of children and young adults exposed to CT scans evidenced that doses of 50 to 60 mGy delivered at high dose-rate were associated to a significant increase of leukemias and cancers, including brain cancer. On the basis of the available data, this article leaves some questions about the plausibility of the linear no threshold hypothesis (LNT) used by radiological protection bodies to control overexposure of the members of public and workers. It concludes that although the plausibility of LNT is fairly weak, using LNT helps to situate the order of magnitude of health risks associated with the development of nuclear power plants and to compare them with those resulting from burning fossil fuels and biomass; the results show that sparing human lives can only be achieved with nuclear for the same quantity of energy produced. (author)

  15. Prototype Biology-Based Radiation Risk Module Project

    Science.gov (United States)

    Terrier, Douglas; Clayton, Ronald G.; Patel, Zarana; Hu, Shaowen; Huff, Janice

    2015-01-01

    Biological effects of space radiation and risk mitigation are strategic knowledge gaps for the Evolvable Mars Campaign. The current epidemiology-based NASA Space Cancer Risk (NSCR) model contains large uncertainties (HAT #6.5a) due to lack of information on the radiobiology of galactic cosmic rays (GCR) and lack of human data. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. Our proposed study will compare DNA damage, histological, and cell kinetic parameters after irradiation in normal 2D human cells versus 3D tissue models, and it will use a multi-scale computational model (CHASTE) to investigate various biological processes that may contribute to carcinogenesis, including radiation-induced cellular signaling pathways. This cross-disciplinary work, with biological validation of an evolvable mathematical computational model, will help reduce uncertainties within NSCR and aid risk mitigation for radiation-induced carcinogenesis.

  16. Radiation risk and its estimation for nuclear facilities

    International Nuclear Information System (INIS)

    Krueger, F.W.

    1979-01-01

    The level of knowledge achieved in estimating risks due to the operation of nuclear facilities is discussed. In this connection it is analyzed to what extent risk estimates may be used for establishing requirements for facilities and measures of radiation protection and accident prevention. At present, estimates of risks are subject to great uncertainties. However, the results attainable already permit to discern the causes of possible accidents and to develop effective measures for preventing such accidents. For the time being (and maybe in principle) risk estimation is possible only with more or less arbitrary premises. Within the foreseeable future, cost-benefit comparisons cannot compensate for discretionary decisions in establishing requirements for measures of radiation protection and accident prevention. In preparing such decisions based on experience, expert opinions, political and socio-economic reflections and views, comparison of the risk of novel technologies with existing ones or accepted risks may be a useful means. (author)

  17. Risk perception in the process of working with radiation sources

    International Nuclear Information System (INIS)

    Carneiro, J.C.G.; Levy, D.; Sanches, M.P.; Rodrigues, D.L.; Sordi, G.M.A.A.

    2017-01-01

    This study discusses occupational risk under three distinct aspects, which are often interconnected or interdependent in the work environment. These are: environmental risks, human failures and equipment failures. The article addresses the potential exposure in the workplace, caused by the agent's physical radiation risk, resulting from handling with sources of ionizing radiation. Based on the history of accidents occurring in normal operations, the study summarizes the main accidents in various facilities and possible causes involving the three aspects of risk. In its final considerations, it presents the lessons learned and the measures to be taken with the intention of contributing to the prevention and mitigation of risks in the work environment. The analysis of accident cases and their causes provide valuable information to prevent the risk of similar accidents and contribute to the improvement of operational projects and procedures

  18. Air travel and radiation risks - review of current knowledge

    International Nuclear Information System (INIS)

    Zeeb, H.; Blettner, M.

    2004-01-01

    Aircrew and passengers are exposed to cosmic radiation, in particular when travelling routes close to the poles and in high altitudes. The paper reviews current radiation measurement and estimation approaches as well as the actual level of cosmic radiation that personnel and travellers receive and summarizes the available epidemiological evidence on health effects of cosmic radiation. On average, German aircrew is exposed to les than 5 mSv per annum, and even frequent travellers only rarely reach values above 1 mSv/year. Cohort studies among aircrew have found very little evidence for an increased incidence or mortality of radiation-associated cancers. Only malignant melanoma rates have consistently found to be increased among male aircrew. Socioeconomic and reproductive aspects are likely to contribute to the slightly elevated breast cancer risk of female aircrew. Cytogenetic studies have not yielded consistent results. Based on these data overall risk increases for cancer among occupationally exposed aircrew appear unlikely. This also applies to air travellers who are usually exposed to much lower radiation levels. Occasional air travel during pregnancy does not pose a significant radiation risk, but further considerations apply in this situation. The currently available studies are limited with regard to methodological issues and case numbers so that a continuation of cohort studies in several European countries is being planned. (orig.) [de

  19. Estimation of radiation risks at low dose

    International Nuclear Information System (INIS)

    1990-04-01

    The report presents a review of the effects caused by radiation in low doses, or at low dose rates. For the inheritable (or ''genetic''), as well as for the cancer producing effects of radiation, present evidence is consistent with: (a) a non-linear relationship between the frequency of at least some forms of these effects, with comparing frequencies caused by doses many times those received annually from natural sources, with those caused by lower doses; (b) a probably linear relationship, however, between dose and frequency of effects for dose rates in the region of that received from natural sources, or at several times this rate; (c) no evidence to indicate the existence of a threshold dose below which such effects are not produced, and a strong inference from the mode of action of radiation on cells at low dose rates that no such thresholds are likely to apply to the detrimental, cancer-producing or inheritable, effects resulting from unrepaired damage to single cells. 19 refs

  20. Radiation Risk Associated with Low Doses of Ionizing Radiation: Irrational Fear or Real Danger

    International Nuclear Information System (INIS)

    Reshetin, V.

    2007-01-01

    The established worldwide practice of protecting people from radiation based on the assessments of radiation risk received in the researches carried out earlier costs hundreds of billions of dollars a year to implement. In the opinion of the well-known experts, the maintenance of the existing radiation protection regulations or moreover acceptance of more tough regulations can influence the development of nuclear power engineering. The accepted practice of assessment of human health risk from radiation may also significantly affect our perception of threats of radiation terrorism. In this work, the critical analysis of publications on the assessment of the effects of small doses of radiation on human health is carried out. In our analysis, we especially emphasize the data on cancer mortality among survivors of the atomic bombing of Hiroshima and Nagasaki who received instantaneous radiation doses of less than 200 mSv including the data on leukemia and solid cancer, as well as epidemiological studies in the regions of India and China with high level of natural radiation. Since the investigations of radiation risk is a base for formulating modern radiation protection regulations, their reliability and validity are of great importance. As follows from the analysis, the subsequent, during three decades, toughening of radiation protection regulations has already led to exceedingly prohibitive standards and impractical recommendations the science-based validity of which can cause serious doubts. Now, a number of world-wide known scientists and authoritative international organizations call for revision of these standards and of the radiation safety concept itself. (author)

  1. Ionizing radiation risk assessment, BEIR IV

    International Nuclear Information System (INIS)

    1991-10-01

    This report of the Subpanel discusses the potential impact on Federal agencies and indicates individual risk factors that could be used by them in risk assessment. The approach used in this CIRRPC report was to consider the risk factors presented in BEIR IV for each radionuclide (or group radioelements) and to make some judgments regarding their validity and/or the uncertainties involved. The coverage of Radon-222 and its progeny dominated the BEIR IV report and this Subpanel felt is was proper to devote more attention to this radionuclide family. This risk factor presented in BEIR IV for radon is 350 cancer deaths per million person-working level months (WLM) of exposure for a lifetime. There is a range of opinions on the conversion from WLM to absorbed dose. As discussed in the text, the use of the WLM concept makes it difficult or infeasible to compare the risk factor for radon with that of other radionuclides which are based on organ dose. This report also includes a discussion of certain fundamental scientific and operational issues that may have decisive effect upon risk factor selection. These adjunct items are dealt with under separate headings and include discussions of threshold dose considerations, extrapolation to low doses, and age at exposure

  2. Assessment of the radiation risk from diagnostic radiology

    International Nuclear Information System (INIS)

    Streffer, C.; Mueller, W.U.

    1995-01-01

    In any assessment of radiation risks from diagnostic radiology the main concern is the possible induction of cancer. It now appears to be beyond all doubt that ionizing rays invite the development of cancer in humans. The radiation doses encountered in diagnostic radiology generally vary from 1 to 50 mSv. For this dose range, no measured values are available to ascertain cancer risks from ionizing rays. The effects of such doses must therefore be extrapolated from higher dose levels under consideration of given dose-effect relationships. All relevant figures for diagnostic X-ray measures are therefore mathematically determined approximate values. The stochastic radiation risk following non-homogeneous radiation exposure is assessed on the basis of the effective dose. This dose was originally introduced to ascertain the risk from radioactive substances incorporated at the working place. A secondary intention was to trigger further developmental processes in radiation protection. Due to the difficulties previously outlined and the uncertainties surrounding the determination and assessment of the effective dose from diagnostic X-ray procedures, this dose should merely be used for technological refinements and comaprisons of examination procedures. It appears unreasonable that the effective doses determined for the individual examinations are summed up to obtain a collective effective dose and to multiply this with a risk factor so as to give an approximation of the resulting deaths from cancer. A reasonable alternative is to inform patients subjected to X-ray examinations about the associated radiation dose and to estimate form this the magnitude of the probable radiation risk. (orig./MG) [de

  3. Harmonization of risk management approaches: radiation and chemical exposures

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, P. [Bhabha Atomic Research Centre, Radiation Safety Systems Div., Mumbai (India)

    2006-07-01

    Assessment of occupational and public risk from the environmental pollutants like chemicals, radiation, etc demands that the effects be considered not only from each individual pollutant, but from the combination of all the pollutants. An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policy makers and decision takers to try to achieve risk reduction in totality. The basis for risk-based radiation dose limits is derived from epidemiological studies, which provide a rich source of data largely unavailable to chemical risk assessors. In addition, use of the principle of optimization as expressed in the ALARA concept has resulted in a safety culture, which is much more than just complying with stipulated limits. The conservative hypothesis of no-threshold dose-effect relation (ICRP) is universally assumed. The end-points and the severity of different classes of pollutants and even different pollutants in a same class vary over a wide range. Hence, it is difficult to arrive at a quantitative value for the net detriment that weighs the various types of end-points and various classes of pollutants. Once the risk due to other pollutants is quantified by some acceptable methodology, it can be expressed in terms of the Risk Equivalent Radiation Dose (R.E.R.D.) for easy comparison with options involving radiation exposure. This paper is an effort to use to quantify and present the risk due to exposure to chemicals and radiation in a common scale for the purpose of easy comparison to facilitate decision taking. (authors)

  4. Harmonization of risk management approaches: radiation and chemical exposures

    International Nuclear Information System (INIS)

    Srinivasan, P.

    2006-01-01

    Assessment of occupational and public risk from the environmental pollutants like chemicals, radiation, etc demands that the effects be considered not only from each individual pollutant, but from the combination of all the pollutants. An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policy makers and decision takers to try to achieve risk reduction in totality. The basis for risk-based radiation dose limits is derived from epidemiological studies, which provide a rich source of data largely unavailable to chemical risk assessors. In addition, use of the principle of optimization as expressed in the ALARA concept has resulted in a safety culture, which is much more than just complying with stipulated limits. The conservative hypothesis of no-threshold dose-effect relation (ICRP) is universally assumed. The end-points and the severity of different classes of pollutants and even different pollutants in a same class vary over a wide range. Hence, it is difficult to arrive at a quantitative value for the net detriment that weighs the various types of end-points and various classes of pollutants. Once the risk due to other pollutants is quantified by some acceptable methodology, it can be expressed in terms of the Risk Equivalent Radiation Dose (R.E.R.D.) for easy comparison with options involving radiation exposure. This paper is an effort to use to quantify and present the risk due to exposure to chemicals and radiation in a common scale for the purpose of easy comparison to facilitate decision taking. (authors)

  5. Systematic review on physician's knowledge about radiation doses and radiation risks of computed tomography

    International Nuclear Information System (INIS)

    Krille, Lucian; Hammer, Gael P.; Merzenich, Hiltrud; Zeeb, Hajo

    2010-01-01

    Background: The frequent use of computed tomography is a major cause of the increasing medical radiation exposure of the general population. Consequently, dose reduction and radiation protection is a topic of scientific and public concern. Aim: We evaluated the available literature on physicians' knowledge regarding radiation dosages and risks due to computed tomography. Methods: A systematic review in accordance with the Cochrane and PRISMA statements was performed using eight databases. 3091 references were found. Only primary studies assessing physicians' knowledge about computed tomography were included. Results: 14 relevant articles were identified, all focussing on dose estimations for CT. Overall, the surveys showed moderate to low knowledge among physicians concerning radiation doses and the involved health risks. However, the surveys varied considerably in conduct and quality. For some countries, more than one survey was available. There was no general trend in knowledge in any country except a slight improvement of knowledge on health risks and radiation doses in two consecutive local German surveys. Conclusions: Knowledge gaps concerning radiation doses and associated health risks among physicians are evident from published research. However, knowledge on radiation doses cannot be interpreted as reliable indicator for good medical practice.

  6. [Ionizing and non-ionizing radiation (comparative risk estimations)].

    Science.gov (United States)

    Grigor'ev, Iu G

    2012-01-01

    The population has widely used mobile communication for already more than 15 years. It is important to note that the use of mobile communication has sharply changed the conditions of daily exposure of the population to EME We expose our brain daily for the first time in the entire civilization. The mobile phone is an open and uncontrollable source of electromagnetic radiation. The comparative risk estimation for the population of ionizing and non-ionizing radiation was carried out taking into account the real conditions of influence. Comparison of risks for the population of ionizing and non-ionizing radiation leads us to a conclusion that EMF RF exposure in conditions of wide use of mobile communication is potentially more harmful than ionizing radiation influence.

  7. Radiation polluton and cancer: comparative risks and proof

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1982-01-01

    A case study of the comparative risks from nuclear radiation and coal burning is presented for a given level of energy production. Mr. Cohen indicates results that might be realized under judicial reforms. Cohen notes the typical overstatement of health hazards from low-level radiation, when current risk assessment methodology derives it from high-level radiation statistics. However, he sees public attention focused on the danger of even low-level radiation brought about by radioactive waste disposal uncertainties. Cohen accuses the information media of generating bad news even when facts point in the opposite direction. He offers as an example, a rationale for the Best-Collins proposal to adjudicate pollution engendered torts under the guidance of reputable authorities rather than impressionable juries guided by proximate case. The paper ends with the question, How can the ajudication system be reformed, given such perverse incentives

  8. Radiation and risk: A look at the data

    International Nuclear Information System (INIS)

    Schillaci, M.E.

    1996-01-01

    This paper is a review of current data on the risks associated with human exposure to ionizing radiation. We examine these risks for dose levels ranging from very high (atomic bomb survivors) to very low (background). The principal end point considered is cancer mortality. Cancer is the only observed clinical manifestation of radiation-induced stochastic effects. Stochastic effects are caused by subtle radiation-induced cellular changes (DNA mutations) that are random in nature and have no threshold dose (assuming less than perfect repair). The probability of such effects increases with dose, but the severity does not. The time required for cancer to develop ranges from several years for leukemia to decades for solid tumors. In addition to somatic cells, radiation can also damage germ cells (ova and sperm) to produce hereditary effects, which are also classified as stochastic. However, clinical manifestations of such effects have not been observed in humans at a statistically significant level

  9. Radiation risk factors and dose limits

    International Nuclear Information System (INIS)

    Barendsen, G.W.

    1979-01-01

    The contents of the ICRP publications 9 (1965) and 26 (1977) are outlined and the research conducted during these years considered. Expressions are derived for the frequency for induction of cancer from the most common irradiations - X rays, gamma rays and electrons. The dose limits advised by the ICRP are discussed and the first two fundamental principles are presented - that no one should be subjected to radiation without useful cause and that in those cases where irradiation is thought necessary, the medical, scientific, social and economic advantages need to be carefully considered with respect to the possible disadvantages. (C.F.)

  10. Radiation risk assessment: the 1982 UNSCEAR report

    International Nuclear Information System (INIS)

    1982-01-01

    Since its establishment in 1955 the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has reported yearly to the General Assembly and at irregular intervals has submitted more comprehensive reports with detailed scientific annexes. In 1982, the eighth in the series of such substantive reports was published. It consists of a summary and a main text outlining the conclusions reached in the Committee's discussions and 12 scientific annexes reviewing in considerable detail the procedures and the scientific information on which such conclusions rest. The Summary of the main conclusions of the Committee is reprinted in this paper

  11. Radiation Dose Risk and Diagnostic Benefit in Imaging Investigations

    OpenAIRE

    Dobrescu, Lidia; Rădulescu, Gheorghe-Cristian

    2015-01-01

    The paper presents many facets of medical imaging investigations radiological risks. The total volume of prescribed medical investigations proves a serious lack in monitoring and tracking of the cumulative radiation doses in many health services. Modern radiological investigations equipment is continuously reducing the total dose of radiation due to improved technologies, so a decrease in per caput dose can be noticed, but the increasing number of investigations has determined a net increase ...

  12. Medical effects and risks of exposure to ionising radiation

    International Nuclear Information System (INIS)

    Mettler, Fred A

    2012-01-01

    Effects and risk from exposure to ionising radiation depend upon the absorbed dose, dose rate, quality of radiation, specifics of the tissue irradiated and other factors such as the age of the individual. Effects may be apparent almost immediately or may take decades to be manifest. Cancer is the most important stochastic effect at absorbed doses of less than 1 Gy. The risk of cancer induction varies widely across different tissues; however, the risk of fatal radiation-induced cancer for a general population following chronic exposure is about 5% Sv −1 . Quantification of cancer risk at doses of less than 0.1 Gy remains problematic. Hereditary risks from irradiation that might result in effects to offspring of humans appear to be much lower and any such potential risks can only be estimated from animal models. At high doses (over 1 Gy) cell killing and modification causes deterministic effects such as skin burns, and bone marrow depression, in which case immunosuppression becomes a critical issue. Acute whole body penetrating gamma irradiation at doses in excess of 2 Gy results in varying degrees of acute radiation sickness and doses over 10 Gy are usually lethal as a result of combined organ injury. (note)

  13. Study on technology for minimizing radiation risk

    International Nuclear Information System (INIS)

    Lee, Jeong Ho; Kim, In Gyu; Kim, Jin Kyu; Lee, Kang Suk; Kim, Kug Chan; Chun, Ki Chung.

    1997-01-01

    Apoptosis, also called programmed cell death to discriminate it from necrosis, is characterized by : chromatin condensation, apoptotic body formation, fragmentation of DNA into oligonucleosome sized pieces, swelling and progressive cell degradation. We examined morphological and biochemical changes of T-lymphocytes following gamma irradiation exposure. The results are followings. 1) Murine lymphocytes have several characteristics : The irradiated cells undergo morphological and biochemical changes characteristic of apoptosis, causing growth delay. (0.01, 0.1, 1.0 Gy) 2) The onset of DNA fragmentation in cells occurs after one more cell divisions. 3) DNA fragmentation in cells occurs in all irradiated group (0.1, 1.0, 2.0, 4.0 Gy, 24 hours following gamma radiation exposure) 4) Apoptotic bodies were detected by confocal microscope with ease when compared with electron microscope. For the developing technology for minimizing radiation damage, the following experimental works have been done. 1) Establishment of experimental system for pre-screening of radioprotectants - Screening of protective substances using TSH bioindicator - Efficacy test of some radioprotective materials 2) TSH bioindicator system can make a scientific role in screening unknown materials for their possible radioprotective effect. (author). 42 refs., 3 tabs., 9 figs

  14. Study on technology for minimizing radiation risk

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Ho; Kim, In Gyu; Kim, Jin Kyu; Lee, Kang Suk; Kim, Kug Chan; Chun, Ki Chung

    1997-01-01

    Apoptosis, also called programmed cell death to discriminate it from necrosis, is characterized by : chromatin condensation, apoptotic body formation, fragmentation of DNA into oligonucleosome sized pieces, swelling and progressive cell degradation. We examined morphological and biochemical changes of T-lymphocytes following gamma irradiation exposure. The results are followings. (1) Murine lymphocytes have several characteristics : The irradiated cells undergo morphological and biochemical changes characteristic of apoptosis, causing growth delay. (0.01, 0.1, 1.0 Gy) (2) The onset of DNA fragmentation in cells occurs after one more cell divisions. (3) DNA fragmentation in cells occurs in all irradiated group (0.1, 1.0, 2.0, 4.0 Gy, 24 hours following gamma radiation exposure) (4) Apoptotic bodies were detected by confocal microscope with ease when compared with electron microscope. For the developing technology for minimizing radiation damage, the following experimental works have been done. (1) Establishment of experimental system for pre-screening of radioprotectants - Screening of protective substances using TSH bioindicator - Efficacy test of some radioprotective materials (2) TSH bioindicator system can make a scientific role in screening unknown materials for their possible radioprotective effect. (author). 42 refs., 3 tabs., 9 figs.

  15. Exposure Risks Among Children Undergoing Radiation Therapy: Considerations in the Era of Image Guided Radiation Therapy

    International Nuclear Information System (INIS)

    Hess, Clayton B.; Thompson, Holly M.; Benedict, Stanley H.; Seibert, J. Anthony; Wong, Kenneth; Vaughan, Andrew T.; Chen, Allen M.

    2016-01-01

    Recent improvements in toxicity profiles of pediatric oncology patients are attributable, in part, to advances in the field of radiation oncology such as intensity modulated radiation (IMRT) and proton therapy (IMPT). While IMRT and IMPT deliver highly conformal dose to targeted volumes, they commonly demand the addition of 2- or 3-dimensional imaging for precise positioning—a technique known as image guided radiation therapy (IGRT). In this manuscript we address strategies to further minimize exposure risk in children by reducing effective IGRT dose. Portal X rays and cone beam computed tomography (CBCT) are commonly used to verify patient position during IGRT and, because their relative radiation exposure is far less than the radiation absorbed from therapeutic treatment beams, their sometimes significant contribution to cumulative risk can be easily overlooked. Optimizing the conformality of IMRT/IMPT while simultaneously ignoring IGRT dose may result in organs at risk being exposed to a greater proportion of radiation from IGRT than from therapeutic beams. Over a treatment course, cumulative central-axis CBCT effective dose can approach or supersede the amount of radiation absorbed from a single treatment fraction, a theoretical increase of 3% to 5% in mutagenic risk. In select scenarios, this may result in the underprediction of acute and late toxicity risk (such as azoospermia, ovarian dysfunction, or increased lifetime mutagenic risk) in radiation-sensitive organs and patients. Although dependent on variables such as patient age, gender, weight, body habitus, anatomic location, and dose-toxicity thresholds, modifying IGRT use and acquisition parameters such as frequency, imaging modality, beam energy, current, voltage, rotational degree, collimation, field size, reconstruction algorithm, and documentation can reduce exposure, avoid unnecessary toxicity, and achieve doses as low as reasonably achievable, promoting a culture and practice of “gentle IGRT.”

  16. Exposure Risks Among Children Undergoing Radiation Therapy: Considerations in the Era of Image Guided Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hess, Clayton B. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Thompson, Holly M. [Department of Diagnostic Radiology, University of California Davis Medical Center, Sacramento, California (United States); Benedict, Stanley H. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Seibert, J. Anthony [Department of Diagnostic Radiology, University of California Davis Medical Center, Sacramento, California (United States); Wong, Kenneth [Department of Radiation Oncology, University of California Los Angeles Jonsson Comprehensive Cancer Center, University of California David Geffen School of Medicine, Los Angeles, California (United States); Vaughan, Andrew T. [Department of Radiation Oncology, University California Davis Comprehensive Cancer Center, Sacramento, California (United States); Chen, Allen M., E-mail: allenmchen@yahoo.com [Department of Radiation Oncology, University of California Los Angeles Jonsson Comprehensive Cancer Center, University of California David Geffen School of Medicine, Los Angeles, California (United States)

    2016-04-01

    Recent improvements in toxicity profiles of pediatric oncology patients are attributable, in part, to advances in the field of radiation oncology such as intensity modulated radiation (IMRT) and proton therapy (IMPT). While IMRT and IMPT deliver highly conformal dose to targeted volumes, they commonly demand the addition of 2- or 3-dimensional imaging for precise positioning—a technique known as image guided radiation therapy (IGRT). In this manuscript we address strategies to further minimize exposure risk in children by reducing effective IGRT dose. Portal X rays and cone beam computed tomography (CBCT) are commonly used to verify patient position during IGRT and, because their relative radiation exposure is far less than the radiation absorbed from therapeutic treatment beams, their sometimes significant contribution to cumulative risk can be easily overlooked. Optimizing the conformality of IMRT/IMPT while simultaneously ignoring IGRT dose may result in organs at risk being exposed to a greater proportion of radiation from IGRT than from therapeutic beams. Over a treatment course, cumulative central-axis CBCT effective dose can approach or supersede the amount of radiation absorbed from a single treatment fraction, a theoretical increase of 3% to 5% in mutagenic risk. In select scenarios, this may result in the underprediction of acute and late toxicity risk (such as azoospermia, ovarian dysfunction, or increased lifetime mutagenic risk) in radiation-sensitive organs and patients. Although dependent on variables such as patient age, gender, weight, body habitus, anatomic location, and dose-toxicity thresholds, modifying IGRT use and acquisition parameters such as frequency, imaging modality, beam energy, current, voltage, rotational degree, collimation, field size, reconstruction algorithm, and documentation can reduce exposure, avoid unnecessary toxicity, and achieve doses as low as reasonably achievable, promoting a culture and practice of “gentle IGRT.”.

  17. A mathematical foundation for controlling radiation health risks

    International Nuclear Information System (INIS)

    Kumazawa, S.

    2000-01-01

    Radiation protection is to attain an adequate control of radiation health risk compared with other risks. Our society in the 21 st century is predicted by some experts to seek the high priority of safety for expanding activity of human beings. The law of controlling risks will be a key subject to serve the safety of human beings and their environment. The main principles of the ICRP system of radiological system are strongly relating to the general law of various risk controls. The individual-based protection concept clearly gives us a mathematical model of controlling risks in general. This paper discusses the simplest formulation of controlling risks in the ICRP system, including other relating systems. First, the basic characteristics of occupational exposure as a risk control is presented by analyzing the data compiled over half a century. It shows the relation ship between dose control levels and individually controlled doses. The individual-based control also exerts some influence on the resultant collective dose. The study of occupational exposure concludes the simple mathematical expression of controlling doses under the ICRP system as shown by Kumazawa and Numakunai. Second, the typical characteristics of biological effects with repair or recovery of bio-systems are given by analyzing the data published. Those show the relationship between dose and biologically controlled or regulated response. The bio-system is undoubtedly relating to cybernetics that contains many functions of controlling risks. Consequently radiation effects might somewhat express the feature of biological risk controls. The shouldered survival of irradiated cells shows cybernetic characteristics that are assumed to be the mathematical foundation of controlling risks. The dose-response relationship shows another type of cybernetic characteristics, which could be reduced to the same basic form of controlling risks. The limited study of radiation effects definitely confirms the two

  18. Distance factor on reducing scattered radiation risk during interventional fluoroscopy

    International Nuclear Information System (INIS)

    Husaini Salleh; Mohd Khalid Matori; Muhammad Jamal Mat Isa; Zainal Jamaluddin; Mohd Firdaus Abdul Rahman; Mohd Khairusalih Mohd Zin

    2012-01-01

    Interventional Radiology (IR) is subspecialty of diagnostic radiology where minimally invasive procedures are performed using an x-ray as a guidance. This procedure can deliver high radiation doses to patient and medical staff compared with other radiological method due to long screening time. The use of proper shielding, shorten the exposure time and keep the distance are the practices to reduce scattered radiation risks to staff involve in this procedure. This project is to study the distance factor on reducing the scattered radiation effect to the medical staff. It also may provide the useful information which can be use to establish the scattered radiation profile during the IR for the sake of radiation protection and safety to the medical staff involved. (author)

  19. Risks and hazards from conventional and radiation sources

    International Nuclear Information System (INIS)

    Iyer, P.S.; Ganguly, A.K.

    1978-01-01

    Beneficial uses of radioisotopes in medicine, industry, agriculture and research are discussed. In absence of adequate safety precautions, uses of radiation may also result in harmful biological effects or genetic effects. Radiation risks and hazards are evaluated by comparing with other risks and hazards which are routinely encountered. The risk of fatality per year by various causes in U.S.A. is given. It is stated with examples and observations that some of the routine habits and necessities and minor luxuries are more risky than radiation risks. Countrywide radiation safety program in India by the Department of Atomic Energy is described in brief. Data are given to show that the risks from radiation are much lower in comparison with many conventional sources. More efficient equipment such as image intensifier is recommended to help to reduce the patient dose. It is stated that caution has to be exercised while handling the X-ray machines which may be harmful not only to patients but to doctors also. As regards, nuclear medicine, it is mentioned that though it is a fast expanding speciality in India, the number of procedures carried out in various centres is small as compared to U.S.A. and France. Some instances are given to show the consequences of the ignorance of the radiation hazards in operating machines in X-ray and gamma ray beam therapy facilities. A survey made by DRP, BARC revealed that some research laboratories lacked basic radiation protection requirements in using X-ray crystallography or analytical equipment. (B.G.W.)

  20. Ionizing radiation risks to satellite power systems (SPS) workers

    International Nuclear Information System (INIS)

    1980-11-01

    The radiation risks to the health of workers who will construct and maintain solar power satellites in the space environment were examined. For ionizing radiation, the major concern will be late or delayed health effects, particularly the increased risk of radiation-induced cancer. The estimated lifetime risk for cancer is 0.8 to 5.0 excess deaths per 10,000 workers per rad of exposure. Thus, for example, in 10,000 workers who completed ten missions with an exposure of 40 rem per mission, 320 to 2000 additional deaths in excess of the 1640 deaths from normally occurring cancer, would be expected. These estimates would indicate a 20 to 120% increase in cancer deaths in the worker-population. The wide range in these estimates stems from the choice of the risk-projection model and the dose-response relationsip. The choice between a linear and a linear-quadratic dose-response model may alter the risk estimate by a factor of about two. The method of analysis (e.g., relative vs absolute risk model) can alter the risk estimate by an additional factor of three. Choosing different age and sex distributions can further change the estimate by another factor of up to three. The potential genetic consequences could be of significance, but at the present time, sufficient information on the age and sex distribution of the worker population is lacking for precise estimation of risk. The potential teratogenic consequences resulting from radiation are considered significant. Radiation exposure of a pregnant worker could result in developmental abnormalities

  1. Ionizing radiation risks to satellite power systems (SPS) workers

    Energy Technology Data Exchange (ETDEWEB)

    Lyman, J.T.; Ainsworth, E.J.; Alpen, E.L.; Bond, V.; Curtis, S.B.; Fry, R.J.M.; Jackson, K.L.; Nachtwey, S.; Sondhaus, C.; Tobias, C.A.; Fabrikant, J.I.

    1980-11-01

    The radiation risks to the health of workers who will construct and maintain solar power satellites in the space environment were examined. For ionizing radiation, the major concern will be late or delayed health effects, particularly the increased risk of radiation-induced cancer. The estimated lifetime risk for cancer is 0.8 to 5.0 excess deaths per 10,000 workers per rad of exposure. Thus, for example, in 10,000 workers who completed ten missions with an exposure of 40 rem per mission, 320 to 2000 additional deaths in excess of the 1640 deaths from normally occurring cancer, would be expected. These estimates would indicate a 20 to 120% increase in cancer deaths in the worker-population. The wide range in these estimates stems from the choice of the risk-projection model and the dose-response relationsip. The choice between a linear and a linear-quadratic dose-response model may alter the risk estimate by a factor of about two. The method of analysis (e.g., relative vs absolute risk model) can alter the risk estimate by an additional factor of three. Choosing different age and sex distributions can further change the estimate by another factor of up to three. The potential genetic consequences could be of significance, but at the present time, sufficient information on the age and sex distribution of the worker population is lacking for precise estimation of risk. The potential teratogenic consequences resulting from radiation are considered significant. Radiation exposure of a pregnant worker could result in developmental abnormalities.

  2. Radiation Risk and Possible Consequences for Ukrainian Population

    Energy Technology Data Exchange (ETDEWEB)

    Pivovarov, Alexander [Ukrainian State Chemical-Technology Univ., Dnepropetrovsk (Ukraine)

    2006-09-15

    The paper deals with the values of risk related to environmental pollution with radionuclides from the main sources located both on the territory of Ukraine and outside, which affect the Ukrainian population, in the context of long-range outlook. Ratios of risk for stochastic effects occurrence are given per unit of individual or collective dose, as well as for occurrence of fatal cancer, non-fatal cancer or serious hereditary effects. Besides, the paper mentions not only the impact of ionizing radiation, but severe population stress as well, which in certain regions turns into radiophobia. It is shown that for essential decrease of radiation risk in Ukraine, global problems should be solved, first of all, at the governmental level. Whereas a number of issues connected with the Chernobyl catastrophe are at least partially solved, the problems concerning the effects of radon and other radiation-dangerous factors are still to be tackled.

  3. NASA Space Radiation Risk Project: Overview and Recent Results

    Science.gov (United States)

    Blattnig, Steve R.; Chappell, Lori J.; George, Kerry A.; Hada, Megumi; Hu, Shaowen; Kidane, Yared H.; Kim, Myung-Hee Y.; Kovyrshina, Tatiana; Norman, Ryan B.; Nounu, Hatem N.; hide

    2015-01-01

    The NASA Space Radiation Risk project is responsible for integrating new experimental and computational results into models to predict risk of cancer and acute radiation syndrome (ARS) for use in mission planning and systems design, as well as current space operations. The project has several parallel efforts focused on proving NASA's radiation risk projection capability in both the near and long term. This presentation will give an overview, with select results from these efforts including the following topics: verification, validation, and streamlining the transition of models to use in decision making; relative biological effectiveness and dose rate effect estimation using a combination of stochastic track structure simulations, DNA damage model calculations and experimental data; ARS model improvements; pathway analysis from gene expression data sets; solar particle event probabilistic exposure calculation including correlated uncertainties for use in design optimization.

  4. Probabilistic methodology for estimating radiation-induced cancer risk

    International Nuclear Information System (INIS)

    Dunning, D.E. Jr.; Leggett, R.W.; Williams, L.R.

    1981-01-01

    The RICRAC computer code was developed at Oak Ridge National Laboratory to provide a versatile and convenient methodology for radiation risk assessment. The code allows as input essentially any dose pattern commonly encountered in risk assessments for either acute or chronic exposures, and it includes consideration of the age structure of the exposed population. Results produced by the analysis include the probability of one or more radiation-induced cancer deaths in a specified population, expected numbers of deaths, and expected years of life lost as a result of premature fatalities. These calculatons include consideration of competing risks of death from all other causes. The program also generates a probability frequency distribution of the expected number of cancers in any specified cohort resulting from a given radiation dose. The methods may be applied to any specified population and dose scenario

  5. Radiation Risk and Possible Consequences for Ukrainian Population

    International Nuclear Information System (INIS)

    Pivovarov, Alexander

    2006-01-01

    The paper deals with the values of risk related to environmental pollution with radionuclides from the main sources located both on the territory of Ukraine and outside, which affect the Ukrainian population, in the context of long-range outlook. Ratios of risk for stochastic effects occurrence are given per unit of individual or collective dose, as well as for occurrence of fatal cancer, non-fatal cancer or serious hereditary effects. Besides, the paper mentions not only the impact of ionizing radiation, but severe population stress as well, which in certain regions turns into radiophobia. It is shown that for essential decrease of radiation risk in Ukraine, global problems should be solved, first of all, at the governmental level. Whereas a number of issues connected with the Chernobyl catastrophe are at least partially solved, the problems concerning the effects of radon and other radiation-dangerous factors are still to be tackled

  6. Epidemiological studies of radiation risks (NRPB Association)

    International Nuclear Information System (INIS)

    Muirhead, C.R.; Kellerer, A.M.; Chmelevsky, D.

    1993-01-01

    Objectives of project are: to analyse data on populations exposed to high doses of radiation, such as the Japanese atomic bomb survivors and groups of uranium miners; to examine data on populations exposed at low doses and methods for analysing such data; to perform preparatory work for the compilation of 'probability of causation' tables that are specific to EC countries and that also cover radon daughter exposures; to study the incidence and mortality from thyroid cancer in a cohort with medical exposures to 131 I; to study cancer incidence and mortality among Swedish patients given radiotherapy for skin haemangioma in childhood; and to examine the incidence of second tumours among Italian patients given radiotherapy for cancer of the head, neck, breast, endometrium, uterine cervix or thyroid. Results of the six contributions for the reporting period are presented. (R.P.) 4 refs

  7. Perception of radiation risk from a cross cultural perspective

    International Nuclear Information System (INIS)

    Brenot, J.; Hessler, A.; Joussen, W.; Sjoeberg, L.

    1996-01-01

    Regarding radiation risk individual coping strategies range from apathy, no worry, avoidance, information seeking, changes in life style, inter alia. How they occur and when, is a necessary information for the development of better risk communication programmes. To address these points four particular situations involving radiation were chosen, namely indoor radon exposure, X-ray diagnostic, consumption of irradiated food, and radioactive waste management. Situations correspond to very different contexts, natural exposure (with indoor radon), daily life (with medical diagnostic and food consumption) and the industrial and energy context (with waste). From a cross-cultural perspective it was deemed fruitful to compare these situations in various countries. (author)

  8. Radiation protection standards: A practical exercise in risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Roger H [National Radiological Protection Board (United Kingdom)

    1992-07-01

    Within 12 months of the discovery of x-rays in 1895, it was reported that large doses of radiation were harmful to living human tissues. The first radiation protection standards were set to avoid the early effects of acute irradiation. By the 1950s, evidence was mounting for late somatic effects - mainly a small excess of cancers - in irradiated populations. In the late 1980's, sufficient human epidemiological data had been accumulated to allow a comprehensive assessment of carcinogenic radiation risks following the delivery of moderately high doses. Workers and the public are exposed to lower doses and dose-rates than the groups from whom good data are available so that risks have had to be estimated for protection purposes. However, in the 1990s, some confirmation of these risk factors has been derived occupationally exposed populations. If an estimate is made of the risk per unit dose, then in order to set dose limits, an unacceptable level of risk must be established for both workers and the public. There has been and continues to be a debate about the definitions of 'acceptable' and 'tolerable' and the attributing of numerical values to these definitions. This paper discusses the issues involved in the quantification of these terms and their application to setting dose limits on risk grounds. Conclusions are drawn about the present protection standards and the application of the methods to other fields of risk assessment. (author)

  9. Radiation protection standards: A practical exercise in risk assessment

    International Nuclear Information System (INIS)

    Clarke, Roger H.

    1992-01-01

    Within 12 months of the discovery of x-rays in 1895, it was reported that large doses of radiation were harmful to living human tissues. The first radiation protection standards were set to avoid the early effects of acute irradiation. By the 1950s, evidence was mounting for late somatic effects - mainly a small excess of cancers - in irradiated populations. In the late 1980's, sufficient human epidemiological data had been accumulated to allow a comprehensive assessment of carcinogenic radiation risks following the delivery of moderately high doses. Workers and the public are exposed to lower doses and dose-rates than the groups from whom good data are available so that risks have had to be estimated for protection purposes. However, in the 1990s, some confirmation of these risk factors has been derived occupationally exposed populations. If an estimate is made of the risk per unit dose, then in order to set dose limits, an unacceptable level of risk must be established for both workers and the public. There has been and continues to be a debate about the definitions of 'acceptable' and 'tolerable' and the attributing of numerical values to these definitions. This paper discusses the issues involved in the quantification of these terms and their application to setting dose limits on risk grounds. Conclusions are drawn about the present protection standards and the application of the methods to other fields of risk assessment. (author)

  10. A review of radiation risk estimates

    International Nuclear Information System (INIS)

    1991-06-01

    Three authoritative reports (UNSCEAR-1988, BEIR-V-1990, and ICRP-1990 Recommendations) on risk estimates have been reviewed and compared to previous risk estimates published by the same organizations. The ICRP now uses the term 'probability' in place of the term 'risk'. For fatal cancers, the new ICRP probability estimates are 5.0 x 10 -2 Sv -1 for a population of all ages and 4.0 x 10 -2 Sv -1 for a population of working age. For serious hereditary effects summarized over all generations, the ICRP probability coefficients are 1.0 x 10 -2 Sv -1 for a population of all ages and 0.6 x 10 -2 Sv -1 for a population of working age. For prenatal irradiation, at 8 - 15 weeks after conception, there may be a decrease of 30 I.Q. points per Sv and a risk of cancer which may lie in the range of 2 to 10 x 10 -2 Sv -1 . Based mainly on the new probability estimates the ICRP recommends a limit on effective dose of 20 mSv per year, averaged over 5 years (100 mSv in 5 years) with the further provision that the effective dose should not exceed 50 mSv in any single year. For public exposure the ICRP recommends an annual limit on effective dose of 1 mSv. However, in special circumstances, a higher value of effective dose could be allowed in a single year provided that the average over 5 five years does not exceed 1 mSv per year. Once pregnancy has been declared, the conceptus should be protected by applying a supplementary equivalent dose limit to the surface of the woman's abdomen of 2 mSv for the remainder of the pregnancy and by limiting intakes of radionuclides to about 1/20 of the annual limit on intake. A brief survey of epidemiological studies of workers and the risks from radon and thoron progeny is also included. (110 refs, 29 tabs., 10 figs.)

  11. Radiation risk analysis of tritium in PWR plants

    International Nuclear Information System (INIS)

    Yang Maochun; Wang Shimin

    1999-03-01

    Tritium is a common radionuclide in PWR nuclear power plant. In the normal operation conditions, its radiation risk to plant workers is the internal radiation exposure when tritium existing in air as HTO (hydrogen tritium oxide) is breathed in. As the HTO has the same physical and chemical characteristics as water, the main way that HTO entering the air is by evaporation. There are few opening systems in Nuclear Power Plant, the radiation risk of tritium mainly exists near the area of spent fuel pit and reactor pit. The highest possible radiation risk it may cause--the maximum concentration in air is the level when equilibrium is established between water and air phases for tritium. The author analyzed the relationship among the concentration of HTO in water, in air and the water temperature when equilibrium is established, the equilibrated HTO concentration in air increases with HTO concentration in water and water temperature. The analysis revealed that at 30 degree C, the equilibrated HTO concentration in air might reach 1 DAC (derived air concentration) when the HTO concentration in water is 28 GBq/m 3 . Owing to the operation of plant ventilation systems and the existence of moisture in the input air of the ventilation, the practical tritium concentration in air is much lower than its equilibrated levels, the radiation risk of tritium in PWR plant is quite limited. In 1997, Daya Bay Nuclear Power Plant's practical monitoring result of the HTO concentration in the air of the nuclear island and the urine of workers supported this conclusion. Based on this analysis, some suggestions to the reduction of tritium radiation risk were made

  12. Radiation risk in Republics Belarus after Chernobyl accident

    International Nuclear Information System (INIS)

    Saltanova, I.

    2006-01-01

    Full text: Radiation pollution of the territory of the Republic of Belarus has been considered for a long time as a basic ecological danger source. Since the disaster at Chernobyl, a considerable number of the inhabited areas turned out to be situated on the territory contaminated with the radioactive substances. A risk value of the radiation-inducible affections is used in order to appraise the damage to the health of the population, residing in such regions, in other words - of the long term (stochastic) effects probability, among which malignant neoplasm represents the most serious danger. In many countries the systems of radiological protection and safety criteria are based on ecocentric approaches. Nevertheless the post-Chernobyl situation in the Republic of Belarus is continually producing a wide spectrum of hard questions of human health and social activity on contaminated territories. That is why present work is completely produced in the frameworks of anthropocentric approach. The radiation risk has been evaluated for a number of regions of Gomel areas and Mogilev region in accordance with the linear non-threshold model 'Dose-Effect'. A lifelong risk coefficient of the radiation-inducible cancers of 5% / Zv, offered by the ICRP, is used in the evaluations. The doses, used for the risk assessment, are taken from the Doses Catalogue-1992 of the Ministry of Health, Republic of Belarus, which contains the doses, referring to the years 1991-1992. Correspondingly, our evaluations determine potential cancers, conditioned by the radiation exposure during this period of time. Obtained evaluations do not take into account either the radiation-inducible cancers of the thyroid gland, or the leukemia cases, observed in the liquidators as a result of the radiation exposure in the year 1986. The work also contains an evaluation of the component, specific for the Chernobyl radiation risk, conditioned by the radiation dose, accumulated in the population of the regions

  13. Informing the public about the risks from ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Slovic, P; Fischhoff, B; Lichtenstein, S [Perceptronics, Eugene, OR (USA)

    1981-10-01

    Designers of programs for informing the public about radiation hazards need to consider the difficulties inherent in communicating highly technical information about risk. To be effective, information campaigns must be buttressed by empirical research aimed at determining what people know, what they want to know, and how best to convey that information. Drawing upon studies of risk perception, some of the problems that any information program must confront are described.

  14. Social and psychological factors under realization of radiation risk

    International Nuclear Information System (INIS)

    Sushko, S.N.; Malenchenko, S.A.

    2001-01-01

    In the experiments with mice of Af line, irradiated by gamma-radiation with doses of up to 1.0 Gy and subjected to psycho-emotional effect (the model of 'the provoked aggression') have been investigated the processes of tumour formation. The index of cariogenic efficiency of effects is the number of the induced adenomas in lungs. It has been shown that under separate effect of these factors the frequency of adenomas increases. Under the combined effect the additional number of adenomas per mouse is registered, which exceeds theoretically the expected value assuming additivity of effects, the synergism coefficient was 1.57 (for females). It has been marked that the character of tumour reaction on separate and the combined effect of radiation, as well as the stress-factor has sex distinctions. It has been shown that that real assessment of the radiation risk and the development of the measures system on minimization of medical and biological consequences of the accident should take into account not only the radiation factor, but also a psychological one, especially in those cases when realization of the risk of combined effect of radiation and non-radiation factors can manifest synergism

  15. Ionising radiation and risk of death from leukaemia and lymphoma in radiation-monitored workers (INWORKS)

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Bernd

    2015-07-01

    Since July 2015 the study ''ionising radiation and risk of death from leukaemia and lymphoma in radiation-monitored workers (INWORKS) - an international cohort study'' is available. INWORKS comprised data from 300.000 occupational exposed and dosimetric monitored persons from France, USA and UK. The contribution is a critical discussion of this study with respect to the conclusion of a strong evidence of positive associations between protracted low-dose irradiation exposure and leukemia.

  16. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    Science.gov (United States)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low

  17. Ionizing radiation causing a risk of cancer in man

    International Nuclear Information System (INIS)

    Fichardt, T.; Sandison, A.G.; Savage, D.J.

    1977-01-01

    An attempt has been made to present, in short review, the most important carcinogens that have been implicated in the development of cancer in the various organ sites of the human body and to demonstrate the relatively minor role played by ionizing radiation, especially radiotherapy, in causing a risk of cancer in man

  18. Medicine and ionizing radiation: help cards for risk analysis

    International Nuclear Information System (INIS)

    Gauron, C.

    2004-01-01

    Following an inquiry in Ile de France on radiation protection, a scientific committee associating several institutions and different experts has elaborated cards for help to risk analysis. A first series of this cards is published in this issue documents for the labour physician and will be next on Internet. the other fields of medical use will be covered in the future. (N.C.)

  19. Radiation risk in the context of liability for injury

    International Nuclear Information System (INIS)

    Riley, Peter

    2003-01-01

    It is perceived by the man in the street that low-level radiation from a nuclear facility is more dangerous than that from other practices. The radiation protection system, in particular the ALARA principle, leads to concerns that even the smallest exposure to radiation is abnormal and dangerous. Public perception of the radiation risk leads to fear in the minds of the public. A consequence of this fear itself may be damage to health in the form of psychological damage or nervous shock. The paper draws attention to the liability for damages by radiation, in particular under the common law of the UK and US, and how liability, determined by the court, is not necessarily influenced by scientific rationality. A natural conclusion may be that a claimant suffering injury of the type caused by radiation and who had been exposed to radiation, no matter how small a dose, that could be shown to come from a nuclear installation would be awarded damages against the licensee of the site of the installation unless it could be shown that the injury was predominantly caused by another source (radioactive or otherwise)

  20. Biological effects of radiation and estimation of risk to radiation workers

    International Nuclear Information System (INIS)

    Murthy, M.S.S.

    1987-01-01

    The biological effects of radiation have three stages: physical, chemical and biological. A precise mathematical description of biological effects and of one-to-one correspondence between the initial energy absorption and final effect has not been possible, because several factors are involved in biological effects and their manifestation period varies from less than one second to several years. The mechanism of biological radiation effects is outlined. The two groups of these effects are (1) immediate and (2) delayed. The main aim of radiation protection programme is to eliminate the risk of non-stochastic effects to an acceptable level. The mean annual dose for 30,000 radiation workers in India is 2.7 m Sv. Estimated risk of fatal cancer from this dose is about 50 cases of cancer per year per million workers which is well below the ICRP standard for safe occupation stipulated at fatality rate less than or equal to 100 per year per milion workers. When compared with risk in other occupations, the risk to radiation workers is much less. (M.G.B.)

  1. Adequacy of relative and absolute risk models for lifetime risk estimate of radiation-induced cancer

    International Nuclear Information System (INIS)

    McBride, M.; Coldman, A.J.

    1988-03-01

    This report examines the applicability of the relative (multiplicative) and absolute (additive) models in predicting lifetime risk of radiation-induced cancer. A review of the epidemiologic literature, and a discussion of the mathematical models of carcinogenesis and their relationship to these models of lifetime risk, are included. Based on the available data, the relative risk model for the estimation of lifetime risk is preferred for non-sex-specific epithelial tumours. However, because of lack of knowledge concerning other determinants of radiation risk and of background incidence rates, considerable uncertainty in modelling lifetime risk still exists. Therefore, it is essential that follow-up of exposed cohorts be continued so that population-based estimates of lifetime risk are available

  2. ATM, radiation, and the risk of second primary breast cancer.

    Science.gov (United States)

    Bernstein, Jonine L; Concannon, Patrick

    2017-10-01

    It was first suggested more than 40 years ago that heterozygous carriers for the human autosomal recessive disorder Ataxia-Telangiectasia (A-T) might also be at increased risk for cancer. Subsequent studies have identified the responsible gene, Ataxia-Telangiectasia Mutated (ATM), characterized genetic variation at this locus in A-T and a variety of different cancers, and described the functions of the ATM protein with regard to cellular DNA damage responses. However, an overall model of how ATM contributes to cancer risk, and in particular, the role of DNA damage in this process, remains lacking. This review considers these questions in the context of contralateral breast cancer (CBC). Heterozygous carriers of loss of function mutations in ATM that are A-T causing, are at increased risk of breast cancer. However, examination of a range of genetic variants, both rare and common, across multiple cancers, suggests that ATM may have additional effects on cancer risk that are allele-dependent. In the case of CBC, selected common alleles at ATM are associated with a reduced incidence of CBC, while other rare and predicted deleterious variants may act jointly with radiation exposure to increase risk. Further studies that characterize germline and somatic ATM mutations in breast cancer and relate the detected genetic changes to functional outcomes, particularly with regard to radiation responses, are needed to gain a complete picture of the complex relationship between ATM, radiation and breast cancer.

  3. [Occupational risk related to optical radiation exposure in construction workers].

    Science.gov (United States)

    Gobba, F; Modenese, A

    2012-01-01

    Optical Radiation is a relevant occupational risk in construction workers, mainly as a consequence of the exposure to the ultraviolet (UV) component of solar radiation (SR). Available data show that UV occupational limits are frequently exceeded in these workers, resulting in an increased occupational risk of various acute and chronic effects, mainly to skin and to the eye. One of the foremost is the carcinogenic effect: SR is indeed included in Group 1 IARC (carcinogenic to humans). UV exposure is related to an increase of the incidence of basal cell carcinoma, squamous cell carcinoma of the skin and cutaneous malignant melanoma (CMM). The incidence of these tumors, especially CMM, is constantly increasing in Caucasians in the last 50 years. As a conclusion, an adequate evaluation of the occupational risk related to SR, and adequate preventive measures are essential in construction workers. The role of occupational physicians in prevention is fundamental.

  4. Modifying EPA radiation risk models based on BEIR VII

    International Nuclear Information System (INIS)

    Pawel, D.; Puskin, J.

    2007-01-01

    This paper summarizes a 'draft White Paper' that provides details on proposed changes in EPA's methodology for estimating radiogenic cancer risks. Many of the changes are based on the contents of a recent National Academy of Sciences (NAS) report (BEIR VII), that addresses cancer and genetic risks from low doses of low-LET radiation. The draft White Paper was prepared for a meeting with the EPA's Science Advisory Board's Radiation Advisory Committee (RAC) in September for seeking advice on the application of BEIR VII and on issues relating to these modifications and expansions. After receiving the Advisory review, we plan to implement the changes by publishing the new methodology in an EPA report, which we expect to submit to the RAC for final review. The revised methodology could then be applied to update the cancer risk coefficients for over 800 radionuclides that are published in EPA's Federal Guidance Report 13. (author)

  5. A new perspective on radiation risk communication in Fukushima, Japan

    International Nuclear Information System (INIS)

    Svendsen, E.R.

    2013-01-01

    The March 11, 2011 cascading disasters of the historic earthquake, unprecedented tsunami, and subsequent radioactive substances release from the Fukushima Daiichi nuclear power plant have shocked the world. But the specter of radiation exposure has complicated the earthquake and tsunami disaster aid activities. Herein is a personal commentary on the current status of the risk communication activities within the disaster populations in Fukushima prefecture. A literature review of the current scientific literature was performed focusing on risk communication within the Fukushima region during the disaster recovery phase. I have limited my commentary to only the 5 most relevant of the publications which focus exclusively on the issue of risk communication and the problems which have generated the urgency to improve risk communication. There were several themes which were consistently identified across the articles and echo some of the personal observations of the many types of responses which victims are now demonstrating: fear, anger, distrust, denial, confusion, uncertainty, ambivalence, and hyperbole stood out regarding their varied responses to the current radiological situation and, regarding the government role in risk communication, corruption and lack of transparency. Two recommendations for helping to address these issues in risk communication are the inclusion of a community intermediary and great use of community engagement in the disaster recovery process. Improved risk communication, perhaps using established guidelines and including both community intermediaries and improved community engagement, may prove useful within the radiation affected populations of Japan. (author)

  6. Assessment of genetic risk for human exposure to radiation

    International Nuclear Information System (INIS)

    Sevcenko, V.A.; Rubanovic, A.V.

    2002-01-01

    Full text: The methodology of assessing the genetic risk of radiation exposure is based on the concept of 'hitting the target' in development of which N.V. Timofeeff-Ressovsky has played and important role. To predict genetic risk posed by irradiation, the U N Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has worked out direct and indirect methods of assessment, extrapolation, integral and palpitation criteria of risk analysis that together permit calculating the risk from human exposure on the basis of data obtained for mice. Based on the reports of UNSCEAR for the period from 1958 to 2001 the paper presents a retrospective analysis of the use of direct methods and the doubling dose method for quantitative determination of the genetic risk of human exposure expressed as different hereditary diseases. As early as 1962 UNSCEAR estimated the doubling dose (a dose causing as many mutations as those occurring spontaneously during one generation) at 1 Gy for cases of exposure to ionizing radiations with low LET at a low dose rate and this value was confirmed in the next UNSCEAR reports up to now. For cases of acute irradiation the doubling dose was estimated at 0,3-0,4 Gy for the period under review. The paper considers the evolution of the concepts of human natural hereditary variability which is a basis for assessing the risk of exposure by the doubling dose method. The level of human natural genetic variability per 1 000 000 newborns is estimated at 738 000 hereditary diseases including mendelian, chromosomal and multifactorial ones. The greatest difficulties in assessing the doubling dose value were found to occur in the case of multifactorial diseases the pheno typical expression of which depends on mutational events in polygenic systems and on numerous environmental factors. The introduction in calculations of the potential recoverability correction factor (RPCF) made it possible to assess the genetic risk taking into account this class of

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    International Nuclear Information System (INIS)

    Karam, P. Andrew; Mortazavi, S.M. Javad

    2001-01-01

    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 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 leukemia, breast and

  9. Communicating Radiation Risk to the Population of Fukushima

    International Nuclear Information System (INIS)

    Takamura, N.; Taira, Y.; Yoshida, K.; Nakashima-Hashiguchi, K.; Orita, M.; Yamashita, S.

    2016-01-01

    Radiological specialists from Nagasaki University have served on the medical relief team organized at Fukushima Medical University Hospital (Fukushima City) ever since the accident at the Fukushima Dai-ichi nuclear power plant. Furthermore, we have conducted the radiation crisis communication efforts by spreading correct information on the health effects of radiation as 'advisors on radiation health risk control'. Nagasaki University has been assisting the reconstruction efforts of Kawauchi Village in Fukushima Prefecture, which was the first village to declare that residents could safely return to their homes because radiation doses were found to be at comparatively low levels. In April 2013, Nagasaki University and the Kawauchi government office concluded an agreement concerning comprehensive cooperation toward reconstruction of the village. As a result, we established a satellite facility of the university in the village. In conclusion, training of specialists who can take responsibility for long-term risk communication regarding the health effects of radiation as well as crisis communication in the initial phase of the accident is an essential component of all such recovery efforts. Establishment of a training system for such specialists will be very important both for Japan and other countries worldwide. (authors)

  10. Radiation effects and risks: overview and a new risk perception index

    International Nuclear Information System (INIS)

    Rehani, M.M.

    2015-01-01

    Uncertainty provides opportunities for differences in perception, and radiation risks at low level of exposures involved in few computed tomography scans fall in this category. While there is good agreement among national and international organisations on risk probability of cancer, risk perception has barely been dealt with by these organisations. Risk perception is commonly defined as the subjective judgment that people make about the characteristics and severity of a risk. Severity and latency are important factors in perception. There is a need to connect all these. Leaving risk perception purely as a subjective judgement provides opportunities for people to amplifying risk. The author postulates a risk perception index as severity divided by latency that becomes determining factor for risk perception. It is hoped that this index will bring rationality in risk perception. (authors)

  11. Radiation Dose-Response Relationships and Risk Assessment

    International Nuclear Information System (INIS)

    Strom, Daniel J.

    2005-01-01

    The notion of a dose-response relationship was probably invented shortly after the discovery of poisons, the invention of alcoholic beverages, and the bringing of fire into a confined space in the forgotten depths of ancient prehistory. The amount of poison or medicine ingested can easily be observed to affect the behavior, health, or sickness outcome. Threshold effects, such as death, could be easily understood for intoxicants, medicine, and poisons. As Paracelsus (1493-1541), the 'father' of modern toxicology said, 'It is the dose that makes the poison.' Perhaps less obvious is the fact that implicit in such dose-response relationships is also the notion of dose rate. Usually, the dose is administered fairly acutely, in a single injection, pill, or swallow; a few puffs on a pipe; or a meal of eating or drinking. The same amount of intoxicants, medicine, or poisons administered over a week or month might have little or no observable effect. Thus, before the discovery of ionizing radiation in the late 19th century, toxicology ('the science of poisons') and pharmacology had deeply ingrained notions of dose-response relationships. This chapter demonstrates that the notion of a dose-response relationship for ionizing radiation is hopelessly simplistic from a scientific standpoint. While useful from a policy or regulatory standpoint, dose-response relationships cannot possibly convey enough information to describe the problem from a quantitative view of radiation biology, nor can they address societal values. Three sections of this chapter address the concepts, observations, and theories that contribute to the scientific input to the practice of managing risks from exposure to ionizing radiation. The presentation begins with irradiation regimes, followed by responses to high and low doses of ionizing radiation, and a discussion of how all of this can inform radiation risk management. The knowledge that is really needed for prediction of individual risk is presented

  12. Urban pollution by electromagnetic radiation. What risk for human health?

    International Nuclear Information System (INIS)

    Bressa, G.

    1999-01-01

    Power lines, domestic appliances, radios, TV sets, cell-phones, radar, etc., they are all instruments which, entering our everyday life, cause electromagnetic pollution. The risks for human health as a consequence of being exposed to this kind of radiation haven't been clearly ascertained yet, even if there is proof of the connection between the onset of some tumoral forms and exposure to electromagnetic fields. Many countries, among which Italy, are tackling the problem of safety distances, necessary to reduce exposure to non-ionising radiation, by issuing bills suitable for human health protection [it

  13. CANCER RISKS ATTRIBUTABLE TO LOW DOSES OF IONIZING RADIATION - ASSESSING WHAT WE REALLY KNOW?

    Science.gov (United States)

    Cancer Risks Attributable to Low Doses of Ionizing Radiation - What Do We Really Know?AbstractHigh doses of ionizing radiation clearly produce deleterious consequences in humans including, but not exclusively, cancer induction. At very low radiation doses the situatio...

  14. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    International Nuclear Information System (INIS)

    Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner; Simon, Steven L; Wojcik, Andrzej; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

    2009-01-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222 Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

  15. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Energy Technology Data Exchange (ETDEWEB)

    Hendry, Jolyon H; Sohrabi, Mehdi; Burkart, Werner [Department of Nuclear Sciences and Applications, International Atomic Energy Agency, Vienna (Austria); Simon, Steven L [Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Wojcik, Andrzej [Institute of Nuclear Chemistry and Technology, Warsaw (Poland); Cardis, Elisabeth [Centre for Research in Environmental Epidemiology (CREAL), Municipal Institute of Medical Research (IMIM-Hospital del Mar) and CIBER Epidemiologia y Salud Publica - CIBERESP, Barcelona (Spain); Laurier, Dominique; Tirmarche, Margot [Radiobiology and Epidemiology Department, Radiological and Human Health Division, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses (France); Hayata, Isamu [National Institute of Radiological Sciences, Chiba (Japan)], E-mail: jhendry2002uk@yahoo.com

    2009-06-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of {sup 222}Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case-control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case-control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors.

  16. Human exposure to high natural background radiation: what can it teach us about radiation risks?

    Science.gov (United States)

    Hendry, Jolyon H; Simon, Steven L; Wojcik, Andrzej; Sohrabi, Mehdi; Burkart, Werner; Cardis, Elisabeth; Laurier, Dominique; Tirmarche, Margot; Hayata, Isamu

    2014-01-01

    Natural radiation is the major source of human exposure to ionising radiation, and its largest contributing component to effective dose arises from inhalation of 222Rn and its radioactive progeny. However, despite extensive knowledge of radiation risks gained through epidemiologic investigations and mechanistic considerations, the health effects of chronic low-level radiation exposure are still poorly understood. The present paper reviews the possible contribution of studies of populations living in high natural background radiation (HNBR) areas (Guarapari, Brazil; Kerala, India; Ramsar, Iran; Yangjiang, China), including radon-prone areas, to low dose risk estimation. Much of the direct information about risk related to HNBR comes from case–control studies of radon and lung cancer, which provide convincing evidence of an association between long-term protracted radiation exposures in the general population and disease incidence. The success of these studies is mainly due to the careful organ dose reconstruction (with relatively high doses to the lung), and to the fact that large-scale collaborative studies have been conducted to maximise the statistical power and to ensure the systematic collection of information on potential confounding factors. In contrast, studies in other (non-radon) HNBR areas have provided little information, relying mainly on ecological designs and very rough effective dose categorisations. Recent steps taken in China and India to establish cohorts for follow-up and to conduct nested case–control studies may provide useful information about risks in the future, provided that careful organ dose reconstruction is possible and information is collected on potential confounding factors. PMID:19454802

  17. Radiation related cancer risk after ionization radiation exposure to the Bulgarian population

    International Nuclear Information System (INIS)

    Chobanova, N.; Vasilev, G.; Hadjieva, T.

    2008-01-01

    Average annual individual effective dose of natural radiation background (NRB) for the Bulgarian population is estimated to be 2.33 mSv.a -1 (from 1.60 to 3.06). NRB has been considered nearly constant in time, but during the 20th century the radiation above NRB has gradually increased. It was mainly caused by the medical X-ray and radionuclide diagnostics, radiation treatment, occupational radiation, global radioactive fallout, Chernobyl accident, exploitation of thermal power and nuclear power stations, etc. For the years 1950-2000 collective dose from NRB represents 965 000 man.Sv and radiation over NRB gives 1 042 800 man.Sv. Population risk following radiation exposure is estimated mainly on stochastic health effect by implementation of the so-called Linear non-threshold model (LNM) dose-effect. It postulates no dose threshold for radiation-induced health effects. Using different models, assumptions and assessments, authors have determined the contribution of lethal radiogenic cancer to Bulgarian spontaneous cancer rate to be from 3.7% to 20.6%. Numerous contradictions and concepts about the LNM still persist, because from statistical point of view, LNM can neither be proved nor rejected. (authors)

  18. National Chernobyl registry of Russia: Radiation risks analysis

    International Nuclear Information System (INIS)

    Ivanov, V.K.; Tsyb, A.F.

    1997-01-01

    Ten years have elapsed after the Chernobyl accident. The problem concerning the estimation of the total integral damage to life and health of people exposed to radiation remains very complicated. A negative influence of the Chernobyl included a spectrum of factors which may reinforce each other. In particular, to date there are no theoretical models or practical recommendations on integral estimating the contribution of social and psycho-emotional factors to the risks of diseases due to radiological accidents. On the other hand, for maximum effective rehabilitation of suffered people the ranging and impartial determination of contribution both of proper radiation and non-radiation components of influence are needed. Therefore, continuation of long-standing investigations is of great practical importance to diminish health consequences of the accident. 5 refs, 7 figs, 4 tabs

  19. National Chernobyl registry of Russia: Radiation risks analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, V K; Tsyb, A F [Medical Radiological Research Center (RAMS), Obninsk (Russian Federation)

    1997-09-01

    Ten years have elapsed after the Chernobyl accident. The problem concerning the estimation of the total integral damage to life and health of people exposed to radiation remains very complicated. A negative influence of the Chernobyl included a spectrum of factors which may reinforce each other. In particular, to date there are no theoretical models or practical recommendations on integral estimating the contribution of social and psycho-emotional factors to the risks of diseases due to radiological accidents. On the other hand, for maximum effective rehabilitation of suffered people the ranging and impartial determination of contribution both of proper radiation and non-radiation components of influence are needed. Therefore, continuation of long-standing investigations is of great practical importance to diminish health consequences of the accident. 5 refs, 7 figs, 4 tabs.

  20. Survey of Tsuruga inhabitants concerning radiation and its risks

    International Nuclear Information System (INIS)

    Shinoda, Yoshihiko; Yamano, Naoki

    2015-01-01

    The Fukushima Daiichi nuclear accident has led to changes in the acceptance of nuclear power in many people. The authors conducted an opinion survey of 300 adult inhabitants of Tsuruga city in Fukui prefecture, Japan. The aim of this survey is to obtain people's opinions concerning radiation and its risks. Authors classified Tsuruga inhabitants on the basis of responses to questions on the concept and knowledge of risk and the cognition of radiation by factor and cluster analyses of multivariable analysis. Using the results of these analyses, Tsuruga inhabitants have been assigned to five categories: “acceptance group,” “anxiety group,” and three intermediate groups. (author)

  1. Risks derived from the industrial uses of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, A

    1981-01-01

    The industrial uses of ionizing radiation are clasified according to its importance in the surveillance and control of industrial processes, the possibility of modifying properties of materials under irradiation and the liberation and transformation of nuclear and desintegration energy into other useful forms. Within that framework, the industrial uses of radiation in Spain are presented together with an indication of the amount and classification of responsible operating personal. The basic concepts of risk and benefit are analyzed to show that the public perception of nuclear risk is greater that the real one. To bring both together, it is important to show a good operating experience and to develop a complete and precise set of rules and regulations. The situation in Spain on this later concept is presented in some detail.

  2. Individual-based model for radiation risk assessment

    Science.gov (United States)

    Smirnova, O.

    A mathematical model is developed which enables one to predict the life span probability for mammals exposed to radiation. It relates statistical biometric functions with statistical and dynamic characteristics of an organism's critical system. To calculate the dynamics of the latter, the respective mathematical model is used too. This approach is applied to describe the effects of low level chronic irradiation on mice when the hematopoietic system (namely, thrombocytopoiesis) is the critical one. For identification of the joint model, experimental data on hematopoiesis in nonirradiated and irradiated mice, as well as on mortality dynamics of those in the absence of radiation are utilized. The life span probability and life span shortening predicted by the model agree with corresponding experimental data. Modeling results show the significance of ac- counting the variability of the individual radiosensitivity of critical system cells when estimating the radiation risk. These findings are corroborated by clinical data on persons involved in the elimination of the Chernobyl catastrophe after- effects. All this makes it feasible to use the model for radiation risk assessments for cosmonauts and astronauts on long-term missions such as a voyage to Mars or a lunar colony. In this case the model coefficients have to be determined by making use of the available data for humans. Scenarios for the dynamics of dose accumulation during space flights should also be taken into account.

  3. Review of European research trends of low dose radiation risk

    International Nuclear Information System (INIS)

    Iwasaki, Toshiyasu; Yoshida, Kazuo

    2010-01-01

    Large research projects on low dose radiation effects in Europe and US over the past decade have provided limited scientific knowledge which could underpin the validation of radiation protection systems. Recently in Europe, there have been repeated discussions and dialogues to improve the situation, and as the consequence, the circumstances surrounding low dose radiation risks are changing. In 2009, Multidisciplinary European Low Dose Initiative (MELODI) was established as a trans-national organization capable of ensuring appropriate governance of research in the pursuit of a long term shared vision, and Low Dose Research towards Multidisciplinary Integration (DoReMi) network was launched in 2010 to achieve fairly short term results in order to prove the validity of the MELODI approach. It is expected to be very effective and powerful activities to facilitate the reduction of uncertainties in the understanding of low dose risks, but the regulatory requests rushing the reinforcement of radiological protection regulations based on the precautional principles are more increasing. To develop reasonable radiological protection systems based on scientific evidences, we need to accelerate to collect scientific evidences which could directly underpin more appropriate radiation protection systems even in Japan. For the purpose, we Japan need to develop from an independent standpoint and share as a multidisciplinary vision a long term and holistic research strategy which enables to enhance Japanese advantages such as low dose rate facilities and animal facilities, as soon as possible. (author)

  4. Understanding the risk coming from the radiation exposure

    International Nuclear Information System (INIS)

    Pierzo, J.A.

    2007-01-01

    From 1972, the National Academy has published a series of reports on the biological effects of ionizing radiation (BEIR) in relation to the health effects of the low level radiation. The Environmental Protection Agency, the Department of Energy and the Academy of Sciences of US, began in 1996 the first phase of the BEIR VII report about the health risks associated to the exposure to low level ionizing radiation. The purpose of the first phase of the study is to revise the literature and to decide if enough novel information existed to guarantee the complete study. The National Academies concluded that enough information existed with an appropriate time to carry out the reanalysis. Among the conclusions of BEIR VII are that the current scientific evidence is concordant with the hypothesis of the existence of a linear model without threshold (LSU) in the dose-response relationship among the exposure to ionizing radiation and the cancer development in humans. This implies that very low dose even has the potential of causing deleterious effects in the health, although the risk to low dose is very small. (Author)

  5. Occupational radiation risks in conveyance of bulk phosphate and potash

    International Nuclear Information System (INIS)

    Grof, Y.; Even, O.; Schlesinger, T.; Margaliot, M.

    1996-01-01

    The issue of occupational ionizing radiation risks encountered in the conveyance and storage of Phosphates and Potash as loose cargo got very minor attention from the national health and occupational safety authorities in the world. In Israel, the Phosphates include an average 100- 150 ppm of Uranium in equilibrium with its daughters, while in Phosphates produced in most other countries the inaction reaches regularly only few ppm up to 50 ppm. Because of the high content of the Uranium in the Phosphate in Israel we must take into consideration the radiological implications involved in the handling of this mineral. The radiological implications of handling Potash are less significant but can not be neglected as we demonstrate bellow In this presentation we will estimate the occupational radiological risks involved in the storing and transportation of Phosphate and Potash. Note, that the main risk in working with Phosphate and Potash is the risk from the dust itself (authors)

  6. Occupational radiation risks in conveyance of bulk phosphate and potash

    Energy Technology Data Exchange (ETDEWEB)

    Grof, Y; Even, O; Schlesinger, T; Margaliot, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

    1996-12-01

    The issue of occupational ionizing radiation risks encountered in the conveyance and storage of Phosphates and Potash as loose cargo got very minor attention from the national health and occupational safety authorities in the world. In Israel, the Phosphates include an average 100- 150 ppm of Uranium in equilibrium with its daughters, while in Phosphates produced in most other countries the inaction reaches regularly only few ppm up to 50 ppm. Because of the high content of the Uranium in the Phosphate in Israel we must take into consideration the radiological implications involved in the handling of this mineral. The radiological implications of handling Potash are less significant but can not be neglected as we demonstrate bellow In this presentation we will estimate the occupational radiological risks involved in the storing and transportation of Phosphate and Potash. Note, that the main risk in working with Phosphate and Potash is the risk from the dust itself (authors).

  7. Usage of geotechnologies for risk management in radiation accidents

    International Nuclear Information System (INIS)

    Silva, T.A.A.; Marques, F.A.P.; Murta, Y.L.

    2017-01-01

    Through the use of geotechnologies an important tool can be created for risk management in radiation accidents. With the use of the QGIS software (Las Palmas version), it is shown its applicability in situations of radiological emergency, as in the case of the accident with cesium-137 in Goiânia. The work analyses the risk of a possible accident with the deposit of cesium wastes that still remains in the region, aiming to protect the population with the best exit routes and forms of allocation of the residents

  8. Environmental chemical mutagens and genetic risks: Lessons from radiation genetics

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1996-01-01

    The last three decades have witnessed substantial progress in the development and use of a variety of in vitro and in vivo assay systems for the testing of environmental chemicals which may pose a mutagenic hazard to humans. This is also true of basic studies in chemical mutagenesis on mechanisms, DNA repair, molecular dosimetry, structure-activity relationships, etc. However, the field of quantitative evaluation of genetic risks of environmental chemicals to humans is still in it infancy. This commentary addresses the question of how our experience in estimating genetic risks of exposure to ionizing radiation can be helpful in similar endeavors with environmental chemical mutagens. 24 refs., 3 tabs

  9. Risks, radiation dose and image quality of mammography

    International Nuclear Information System (INIS)

    Menges, V.

    1979-01-01

    For some time to come, early detection of breast cancer will remain the only way to improve the therapeutical success. Mammography is an absolutely indispensible way to take advantage of this opportunity. Today, mammography is undoubtedly the most reliable method of examination for an early detection of breast cancer. Only mammography can detect carcinomas smaller than the critical tumour size of 1cm. If carried out properly and with present dose levels, it involves hardly any radiation risk. (orig.) [de

  10. Some concepts, terminology, and methodology for radiation risk assessment

    International Nuclear Information System (INIS)

    Groer, P.G.; Barlow, R.E.

    1982-01-01

    The controversy concerning cancer risk estimates for human populations exposed to low doses of ionizing radiations is discussed. The authors note that while little can be done to obtain more and better data on human populations, the analysis of available data can be sharpened through the consistent use of appropriate statistical techniques. Some probabilistic concepts that will help to define ''dose-response curve'' are given

  11. Current estimates of radiation risks and implications for dose limits

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1989-01-01

    The publication of the 1988 report of UNSCEAR represents a major step forward in that there is an international consensus on the estimation of risk from exposure to ionising radiation. The estimates of fatal cancers in the UNSCEAR report are up to 4 times the values in the 1977 review. This paper will describe the reasons for the increase, the remaining uncertainties and the implications for dose limits in occupational and public exposure. (author)

  12. Estimating radiation risk induced by CT screening for Korean population

    Science.gov (United States)

    Yang, Won Seok; Yang, Hye Jeong; Min, Byung In

    2017-02-01

    The purposes of this study are to estimate the radiation risks induced by chest/abdomen computed tomography (CT) screening for healthcare and to determine the cancer risk level of the Korean population compared to other populations. We used an ImPACT CT Patient Dosimetry Calculator to compute the organ effective dose induced by CT screening (chest, low-dose chest, abdomen/pelvis, and chest/abdomen/pelvis CT). A risk model was applied using principles based on the BEIR VII Report in order to estimate the lifetime attributable risk (LAR) using the Korean Life Table 2010. In addition, several countries including Hong Kong, the United States (U.S.), and the United Kingdom, were selected for comparison. Herein, each population exposed radiation dose of 100 mSv was classified according to country, gender and age. For each CT screening the total organ effective dose calculated by ImPACT was 6.2, 1.5, 5.2 and 11.4 mSv, respectively. In the case of Korean female LAR, it was similar to Hong Kong female but lower than those of U.S. and U.K. females, except for those in their twenties. The LAR of Korean males was the highest for all types of CT screening. However, the difference of the risk level was negligible because of the quite low value.

  13. Perception of radiation related risks among three population groups

    International Nuclear Information System (INIS)

    Mihai, L.T.; Milu, C.; Voicu, B.; Enachescu, D.

    2003-01-01

    A questionnaire survey was conducted among three groups that mainly differ in socioeconomic status and professional exposure to ionizing radiations. Seventy-seven (26.3%) of the respondents were professionally exposed to radiation, 35 (11.9%) were medical doctors without professional exposure and 177 (68.4%) belonged to the general population group. The level of anxiety toward radiation, expressed as a concernedness index, is significantly lower in people who are professionally exposed to radiation compared to medical doctors and general population (0.81±0.94, 1.42±1.21 and 1.72±1.34 respectively, p < 0.001). In a similar manner, concernedness index values varied with the education status, with lowest values among medical university graduates and highest among public school graduates (p < 0.001). Both university-graduated groups significantly differ from the non-university groups (p < 0.05). Knowledge about radiation and knowledge about emergency plans in nuclear accident/incident were also checked in relation with concernedness, the results confirming the hypothesis that better knowledge associates lower concernedness. The extent to which people accept the civil utilization of nuclear power is also related to concernedness and knowledge, significant associations having been found. The results suggest that a political decision in radiation matter requires a valid analysis of the public's understanding and acceptance. For that reason, it is important that radiological protection authorities develop new plans and materials for communicating with people, in order to improve knowledge upon ionizing radiation, irradiation risks and safety of nuclear energy application for civil purposes. (author)

  14. Female gonadal shielding with automatic exposure control increases radiation risks

    Energy Technology Data Exchange (ETDEWEB)

    Kaplan, Summer L.; Zhu, Xiaowei [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA (United States); Magill, Dennise; Felice, Marc A. [University of Pennsylvania, Environmental Health and Radiation Safety, Philadelphia, PA (United States); Xiao, Rui [University of Pennsylvania, Department of Biostatistics and Epidemiology, Philadelphia, PA (United States); Ali, Sayed [Temple University Hospital, Department of Radiology, Philadelphia, PA (United States)

    2018-02-15

    Gonadal shielding remains common, but current estimates of gonadal radiation risk are lower than estimated risks to colon and stomach. A female gonadal shield may attenuate active automatic exposure control (AEC) sensors, resulting in increased dose to colon and stomach as well as to ovaries outside the shielded area. We assess changes in dose-area product (DAP) and absorbed organ dose when female gonadal shielding is used with AEC for pelvis radiography. We imaged adult and 5-year-old equivalent dosimetry phantoms using pelvis radiograph technique with AEC in the presence and absence of a female gonadal shield. We recorded DAP and mAs and measured organ absorbed dose at six internal sites using film dosimetry. Female gonadal shielding with AEC increased DAP 63% for the 5-year-old phantom and 147% for the adult phantom. Absorbed organ dose at unshielded locations of colon, stomach and ovaries increased 21-51% in the 5-year-old phantom and 17-100% in the adult phantom. Absorbed organ dose sampled under the shield decreased 67% in the 5-year-old phantom and 16% in the adult phantom. Female gonadal shielding combined with AEC during pelvic radiography increases absorbed dose to organs with greater radiation sensitivity and to unshielded ovaries. Difficulty in proper use of gonadal shields has been well described, and use of female gonadal shielding may be inadvisable given the risks of increasing radiation. (orig.)

  15. Decommissioning and material recycling. Radiation risk management issues

    International Nuclear Information System (INIS)

    Dodd, D.H.

    1996-09-01

    Once nuclear fuel cycle facilities have permanently stopped operations they have to be decommissioned. The decommissioning of a nuclear facility involves the surveillance and dismantling of the facility systems and buildings, the management of the materials resulting from the dismantling activities and the release of the site for further use. The management of radiation risks associated with these activities plays an important role in the decommissioning process. Existing legislation covers many aspects of the decommissioning process. However, in most countries with nuclear power programmes legislation with respect to decommissioning is incomplete. In particular this is true in the Netherlands, where government policy with respect to decommissioning is still in development. Therefore a study was performed to obtain an overview of the radiation risk management issues associated with decommissioning and the status of the relevant legislation. This report describes the results of that study. It is concluded that future work at the Netherlands Energy Research Foundation on decommissioning and radiation risk management issues should concentrate on surveillance and dismantling activities and on criteria for site release. (orig.)

  16. Female gonadal shielding with automatic exposure control increases radiation risks

    International Nuclear Information System (INIS)

    Kaplan, Summer L.; Zhu, Xiaowei; Magill, Dennise; Felice, Marc A.; Xiao, Rui; Ali, Sayed

    2018-01-01

    Gonadal shielding remains common, but current estimates of gonadal radiation risk are lower than estimated risks to colon and stomach. A female gonadal shield may attenuate active automatic exposure control (AEC) sensors, resulting in increased dose to colon and stomach as well as to ovaries outside the shielded area. We assess changes in dose-area product (DAP) and absorbed organ dose when female gonadal shielding is used with AEC for pelvis radiography. We imaged adult and 5-year-old equivalent dosimetry phantoms using pelvis radiograph technique with AEC in the presence and absence of a female gonadal shield. We recorded DAP and mAs and measured organ absorbed dose at six internal sites using film dosimetry. Female gonadal shielding with AEC increased DAP 63% for the 5-year-old phantom and 147% for the adult phantom. Absorbed organ dose at unshielded locations of colon, stomach and ovaries increased 21-51% in the 5-year-old phantom and 17-100% in the adult phantom. Absorbed organ dose sampled under the shield decreased 67% in the 5-year-old phantom and 16% in the adult phantom. Female gonadal shielding combined with AEC during pelvic radiography increases absorbed dose to organs with greater radiation sensitivity and to unshielded ovaries. Difficulty in proper use of gonadal shields has been well described, and use of female gonadal shielding may be inadvisable given the risks of increasing radiation. (orig.)

  17. Genetic risks associated with radiation exposures during space flight

    International Nuclear Information System (INIS)

    Grahn, D.

    1983-01-01

    Although the genetic risks of space radiation do not pose a significant hazard to the general population, the risks may be very important to the individual astronaut. The present paper summarizes some experimental results on the induction of dominant lethal mutations and chromosomal damage in the first generation which may be used in the prediction of the genetic risks of radiation exposures of space crews. Young adult male mice were exposed to single, weekly and continuous doses of gamma rays, neutrons in single doses and weekly exposures and continuous doses of Pu-239 alpha particles. Evaluation of fetal survival rates in females mated to the exposed males shows the mutation rate in individuals exposed to gamma rays to decline as the exposure period is prolonged and the dose rate is reduced, while the response to neutrons is in the opposite direction. Cytological determinations show the rate of balanced chromosomal translocations to drop as gamma ray exposures change from one-time to continuous, however little or no dose rate effect is seen with neutron radiation and alpha particle exposure shows no regular dose-response. Based on the above results, it is predicted that the rate of dominant mutations and transmissible chromosome aberrations in astronauts on a 100-day mission will increase by 4.5 to 41.25 percent over the spontaneous rate. 35 references

  18. Female gonadal shielding with automatic exposure control increases radiation risks.

    Science.gov (United States)

    Kaplan, Summer L; Magill, Dennise; Felice, Marc A; Xiao, Rui; Ali, Sayed; Zhu, Xiaowei

    2018-02-01

    Gonadal shielding remains common, but current estimates of gonadal radiation risk are lower than estimated risks to colon and stomach. A female gonadal shield may attenuate active automatic exposure control (AEC) sensors, resulting in increased dose to colon and stomach as well as to ovaries outside the shielded area. We assess changes in dose-area product (DAP) and absorbed organ dose when female gonadal shielding is used with AEC for pelvis radiography. We imaged adult and 5-year-old equivalent dosimetry phantoms using pelvis radiograph technique with AEC in the presence and absence of a female gonadal shield. We recorded DAP and mAs and measured organ absorbed dose at six internal sites using film dosimetry. Female gonadal shielding with AEC increased DAP 63% for the 5-year-old phantom and 147% for the adult phantom. Absorbed organ dose at unshielded locations of colon, stomach and ovaries increased 21-51% in the 5-year-old phantom and 17-100% in the adult phantom. Absorbed organ dose sampled under the shield decreased 67% in the 5-year-old phantom and 16% in the adult phantom. Female gonadal shielding combined with AEC during pelvic radiography increases absorbed dose to organs with greater radiation sensitivity and to unshielded ovaries. Difficulty in proper use of gonadal shields has been well described, and use of female gonadal shielding may be inadvisable given the risks of increasing radiation.

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

    International Nuclear Information System (INIS)

    Nicolli, D.

    1988-01-01

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

  20. Radiation dose and radiation risk to foetuses and newborns during X-ray examinations

    Energy Technology Data Exchange (ETDEWEB)

    Kettunen, A. [Oulu Univ. (Finland)

    2004-05-01

    The purpose of this study is to determine the way in which the demands set by degree 423/2000 by the Ministry of Social Affairs and Health are fulfilled with respect to the most radiosensitive groups, the foetus and the child, by estimating the radiation dose and radiation risk to the foetus from x-ray examinations of an expectant mother's pelvic region, finding out the practice involved in preventing doses to embryos and foetuses and assessing dose practices in cases where an embryo or foetus is or shall be exposed, and by estimating radiation dose and risk due to the radiation received by a new-born being treated in a paediatric intensive care unit. No statistics are available in Finland to indicate how many x-ray examinations of the pelvic region and lower abdomen are made to pregnant patients or to show the dose and risk to the foetus due these examinations. In order to find out the practices in radiological departments concerning the pelvic x-ray examination of fertile woman and the number of foetuses exposed, a questionnaire was sent to all radiation safety officers responsible for the safe use of radiation (n = 290). A total of 173 questionnaires were returned. This study recorded the technique and Dose-Area Product of 118 chest examinations of newborns in paediatric intensive care units. Entrance surface doses and effective doses were calculated separately to each newborn. Based on the patient records, the number of all x-ray examinations during the study was calculated and the effective doses were estimated retrospectively to each child. The radiation risk was estimated both for the foetuses and for the newborns. According to this study, it is rare in Finland to expose a pregnant woman to radiation. On the other hand, with the exception of pelvimetry examinations, there are no compiled statistics concerning the number of pelvic x-ray examinations of a pregnant woman. There was no common practice on how to exclude the possibility of pregnancy. The dose

  1. Radiation dose and radiation risk to foetuses and newborns during X-ray examinations

    International Nuclear Information System (INIS)

    Kettunen, A.

    2004-05-01

    The purpose of this study is to determine the way in which the demands set by degree 423/2000 by the Ministry of Social Affairs and Health are fulfilled with respect to the most radiosensitive groups, the foetus and the child, by estimating the radiation dose and radiation risk to the foetus from x-ray examinations of an expectant mother's pelvic region, finding out the practice involved in preventing doses to embryos and foetuses and assessing dose practices in cases where an embryo or foetus is or shall be exposed, and by estimating radiation dose and risk due to the radiation received by a new-born being treated in a paediatric intensive care unit. No statistics are available in Finland to indicate how many x-ray examinations of the pelvic region and lower abdomen are made to pregnant patients or to show the dose and risk to the foetus due these examinations. In order to find out the practices in radiological departments concerning the pelvic x-ray examination of fertile woman and the number of foetuses exposed, a questionnaire was sent to all radiation safety officers responsible for the safe use of radiation (n = 290). A total of 173 questionnaires were returned. This study recorded the technique and Dose-Area Product of 118 chest examinations of newborns in paediatric intensive care units. Entrance surface doses and effective doses were calculated separately to each newborn. Based on the patient records, the number of all x-ray examinations during the study was calculated and the effective doses were estimated retrospectively to each child. The radiation risk was estimated both for the foetuses and for the newborns. According to this study, it is rare in Finland to expose a pregnant woman to radiation. On the other hand, with the exception of pelvimetry examinations, there are no compiled statistics concerning the number of pelvic x-ray examinations of a pregnant woman. There was no common practice on how to exclude the possibility of pregnancy. The dose to a

  2. Solid cancer risks from radiation exposure for the Australian population

    International Nuclear Information System (INIS)

    Wise, K.N.

    2003-01-01

    Estimates are made of the risks to the Australian population as a function of age and gender for mortality or morbidity for all solid cancers after exposure to radiation. Excess relative risk (ERR) and excess absolute risk (EAR) models are used. The model coefficients are re-evaluated for radiation doses expressed as effective dose using data from the Japanese Life Span Study. Life-table methods are used throughout and the risk measures studied are: the risk of exposure related death, RERD and the risk of exposure related cancer, RERC. Australian life-table data and the age-specific cancer incidence and mortality rates of Australian males and females are taken from recent published tables. No dose and dose-rate effectiveness factor is applied. Sources of uncertainty used to calculate the confidence regions for the estimated risks include the statistical uncertainties of the model parameters and of the extrapolation of the risks beyond the period supported by the epidemiological data. Summary values of the risks are reported as averages of those calculated from the ERR and the EAR models. For males, the mortality risks per sievert range from 14% for 0-9 year age group, 7% at 30-39 years and 4% at 50-59 years. Corresponding values for females are 20%, 10% and 6%. Incidence risks are higher: for males the estimates are 32% for the 0-9 year group, 12% at 30-39 and 5% at 50-59. Corresponding values for females are 56%, 20% and 8%. The 90% confidence regions are about ± 50% of these values. Estimates are given for the risks from CT whole-body scanning or virtual colonoscopy which could be used for cancer screening. If used at 3 year intervals and the effective dose per procedure is 10 mSv, then the RERD for males beginning screening at 40, 50 and 60 years is 0.4%, 0.3% and 0.1%, respectively and for females, 0.6%, 0.4% and 0.2%, respectively. RERD estimates for a 5 year interval between screens are about one-third smaller. Copyright (2003) Australasian College of

  3. RISKAP, Risk Assessment of Radiation Exposure for Population

    International Nuclear Information System (INIS)

    1992-01-01

    1 - Description of program or function: RISKAP estimates risk to a population exposed to radioactivity. Risk is measured in terms of the expected number of premature deaths resulting from radiogenic cancers, the number of years of life lost as a result of these deaths, and the average number of years of life lost per premature death. RISKAP accommodates latency and plateau periods that vary with age at exposure and risk functions that vary with age at exposure as well as time after exposure. 2 - Method of solution: The user defines a population by specifying its size and age distribution at reference time zero, its subsequent age-specific mortality rates assuming no radiogenic deaths, and its subsequent birth rates. Radiation doses that may vary with age and time are also assigned by the user. These doses are used to compute an annual, age-specific risk of premature cancer death, based on a dose-response function selected by the user. Calculations of premature radiation deaths, deaths from all causes, and new age distribution of the population are performed for one-year intervals. The population is tracked over any specified period. This version of RISKAP allows the use of a linear, quadratic, or linear-quadratic dose-response function. The user may substitute any preferred dose-response function by editing the code. 3 - Restrictions on the complexity of the problem: None noted

  4. Heart irradiation as a risk factor for radiation pneumonitis

    International Nuclear Information System (INIS)

    Huang, Ellen X.; El Naqa, Issam; Deasy, Joseph O.; Bradley, Jeffrey D.; Hope, Andrew J.; Lindsay, Patricia E.; Trovo, Marco

    2011-01-01

    Purpose. To investigate the potential role of incidental heart irradiation on the risk of radiation pneumonitis (RP) for patients receiving definitive radiation therapy for non-small-cell lung cancer (NSCLC). Material and methods. Two hundred and nine patient datasets were available for this study. Heart and lung dose-volume parameters were extracted for modeling, based on Monte Carlo-based heterogeneity corrected dose distributions. Clinical variables tested included age, gender, chemotherapy, pre-treatment weight-loss, performance status, and smoking history. The risk of RP was modeled using logistic regression. Results. The most significant univariate variables were heart related, such as heart heart V65 (percent volume receiving at least 65 Gy) (Spearman Rs = 0.245, p < 0.001). The best-performing logistic regression model included heart D10 (minimum dose to the hottest 10% of the heart), lung D35, and maximum lung dose (Spearman Rs 0.268, p < 0.0001). When classified by predicted risk, the RP incidence ratio between the most and least risky 1/3 of treatments was 4.8. The improvement in risk modeling using lung and heart variables was better than using lung variables alone. Conclusions. These results suggest a previously unsuspected role of heart irradiation in many cases of RP

  5. A comparative review of radiation-induced cancer risk models

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Hee; Kim, Ju Youl [FNC Technology Co., Ltd., Yongin (Korea, Republic of); Han, Seok Jung [Risk and Environmental Safety Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    With the need for a domestic level 3 probabilistic safety assessment (PSA), it is essential to develop a Korea-specific code. Health effect assessments study radiation-induced impacts; in particular, long-term health effects are evaluated in terms of cancer risk. The objective of this study was to analyze the latest cancer risk models developed by foreign organizations and to compare the methodology of how they were developed. This paper also provides suggestions regarding the development of Korean cancer risk models. A review of cancer risk models was carried out targeting the latest models: the NUREG model (1993), the BEIR VII model (2006), the UNSCEAR model (2006), the ICRP 103 model (2007), and the U.S. EPA model (2011). The methodology of how each model was developed is explained, and the cancer sites, dose and dose rate effectiveness factor (DDREF) and mathematical models are also described in the sections presenting differences among the models. The NUREG model was developed by assuming that the risk was proportional to the risk coefficient and dose, while the BEIR VII, UNSCEAR, ICRP, and U.S. EPA models were derived from epidemiological data, principally from Japanese atomic bomb survivors. The risk coefficient does not consider individual characteristics, as the values were calculated in terms of population-averaged cancer risk per unit dose. However, the models derived by epidemiological data are a function of sex, exposure age, and attained age of the exposed individual. Moreover, the methodologies can be used to apply the latest epidemiological data. Therefore, methodologies using epidemiological data should be considered first for developing a Korean cancer risk model, and the cancer sites and DDREF should also be determined based on Korea-specific studies. This review can be used as a basis for developing a Korean cancer risk model in the future.

  6. Risk equivalent of exposure versus dose of radiation

    International Nuclear Information System (INIS)

    Bond, V.P.

    1986-01-01

    Radiation is perhaps unique among all agents of interest in the Health Sciences in that it alone is both a therapeutic agent for the control of cancer and an essentially ubiquitous environmental agent with a potential for increasing the cancer rate in human populations. Therapy of tumors is accomplished with the high-level exposure (HLE) to radiation in order to effect control or a cure. Thus, it conforms to the concepts and approaches of pharmacology, toxicology, and therapeutic medicine. Only one function, that which relates the object-oriented and nonstochastic independent variable organ dose to its effect on a cancer or an organ, is needed to estimate the probability, P 2 , of a quantal response. Only P 2 is needed because P 1 , that the cancer slated for such treatment will receive some amount of the agent and be affected to some degree, is effectively unity. The health problem involving low-level exposure (LLE) to radiation, in contrast, is not at all analogous to those of pharmacology, toxicology, and medicine. Rather, it presents a public health problem in that it is a health population, albeit of cells, that is exposed in a radiation field composed of moving radiation particles with some attendant low-order carcinogenic or mutagenic risk. Thus, the concepts, quantities, and terminology applied to low-level radiation must be modified from their present orientation toward pharmacology, toxicology, medicine, and dose to conform to those of public health and accident statistics, in which both P 1 and P 2 for the exposed cells must be estimated

  7. Risks of carcinogenesis from electromagnetic radiation of mobile telephony devices.

    Science.gov (United States)

    Yakymenko, I; Sidorik, E

    2010-07-01

    Intensive implementation of mobile telephony technology in everyday human life during last two decades has given a possibility for epidemiological estimation of long-term effects of chronic exposure of human organism to low-intensive microwave (MW) radiation. Latest epidemiological data reveal a significant increase in risk of development of some types of tumors in chronic (over 10 years) users of mobile phone. It was detected a significant increase in incidence of brain tumors (glioma, acoustic neuroma, meningioma), parotid gland tumor, seminoma in long-term users of mobile phone, especially in cases of ipsilateral use (case-control odds ratios from 1.3 up to 6.1). Two epidemiological studies have indicated a significant increase of cancer incidence in people living close to the mobile telephony base station as compared with the population from distant area. These data raise a question of adequacy of modern safety limits of electromagnetic radiation (EMR) exposure for humans. For today the limits were based solely on the conception of thermal mechanism of biological effects of RF/MW radiation. Meantime the latest experimental data indicate the significant metabolic changes in living cell under the low-intensive (non-thermal) EMR exposure. Among reproducible biological effects of low-intensive MWs are reactive oxygen species overproduction, heat shock proteins expression, DNA damages, apoptosis. The lack of generally accepted mechanism of biological effects of low-intensive non-ionizing radiation doesn't permit to disregard the obvious epidemiological and experimental data of its biological activity. Practical steps must be done for reasonable limitation of excessive EMR exposure, along with the implementation of new safety limits of mobile telephony devices radiation, and new technological decisions, which would take out the source of radiation from human brain.

  8. Epidemiological and radio-biological studies in high background radiation areas of Kerala coast: implications in radiation protection science and human health

    International Nuclear Information System (INIS)

    Das, Birajalaxmi

    2018-01-01

    Till date, Linear No Threshold hypothesis (LNT) is well accepted in radiation protection science in spite of its limitations. However, dose response studies using multiple biological end points from high-background radiation areas have challenged the linearity. Radio-biological and epidemiological studies from high level natural radiation areas of Kerala coast showed non-linearity as well as efficient repair of DNA damage in HLNRA indicating that dose limits for public exposure needs to be revisited which may have implications in radiation protection science, human health and low dose radiation biology. However, further studies using high throughput approach is required to identify chronic radiation signatures in human population exposed to elevated level of natural background radiation

  9. [Solar radiation exposure in agriculture: an underestimated risk].

    Science.gov (United States)

    Gobba, F

    2012-01-01

    Solar Radiation (SR) is a major occupational risk in agriculture, mainly related to its ultraviolet (UV) component. Available data show that UV occupational limits are frequently exceeded in these workers, resulting in an increased occupational risk of various acute and chronic effects, mainly to skin and to the eye. One of the foremost is the carcinogenic effect: SR is indeed included in Group 1 IARC (carcinogenic to humans). UV exposure is related to an increase of the incidence of basal cell carcinoma and squamous cell carcinoma of the skin, and cutaneous malignant melanoma (CMM). The incidence of these tumors, especially CMM, is constantly increasing in Caucasians in the last 50 years. As a conclusion, an adequate evaluation of the occupational risk related to SR, and adequate preventive measures are essential in agriculture. The role of the Occupational Physician in prevention is fundamental.

  10. Risk estimates for the health effects of alpha radiation

    International Nuclear Information System (INIS)

    Thomas, D.C.; McNeill, K.G.

    1981-09-01

    This report provides risk estimates for various health effects of alpha radiation. Human and animal data have been used to characterize the shapes of dose-response relations and the effects of various modifying factors, but quantitative risk estimates are based solely on human data: for lung cancer, on miners in the Colorado plateau, Czechoslovakia, Sweden, Ontario and Newfoundland; for bone and head cancers, on radium dial painters and radium-injected patients. Slopes of dose-response relations for lung cancer show a tendency to decrease with increasing dose. Linear extrapolation is unlikely to underestimate the excess risk at low doses by more than a factor of l.5. Under the linear cell-killing model, our best estimate

  11. Comparison of methods for prioritizing risk in radiation oncology

    International Nuclear Information System (INIS)

    Biazotto, Bruna; Tokarski, Marcio

    2016-01-01

    Proactive risk management tools, such as Failure Mode and Effect Analysis (FEMA), were imported from engineering and have been widely used in Radiation Oncology. An important step in this process is the risk prioritization and there are many methods to do that. This paper compares the risk prioritization of computerized planning phase in interstitial implants with high dose rate brachytherapy performed with Health Care Failure Mode and Effect Analysis (HFMEA) and FMEA with guidelines given by the Task Group 100 (TG 100) of the American Association of Physicists in Medicine. Out of the 33 possible failure modes of this process, 21 require more attention when evaluated by HFMEA and 22, when evaluated by FMEA TG 100. Despite the high coincidence between the methods, the execution of HFMEA was simpler. (author)

  12. Radiation efficacy and biological risk from whole-breast irradiation via intensity modulated radiation therapy (IMRT)

    Science.gov (United States)

    Desantis, David M.

    Radiotherapy is an established modality for women with breast cancer. During the delivery of external beam radiation to the breast, leakage, scattered x-rays from the patient and the linear accelerator also expose healthy tissues and organs outside of the breast, thereby increasing the patient's whole-body dose, which then increases the chance of developing a secondary, radiation-induced cancer. Generally, there are three IntensityModulated Radiotherapy (IMRT) delivery techniques from a conventional linear accelerator; forward planned (FMLC), inverse planned 'sliding window' (DMLC), and inverse planned 'step-and-shoot' (SMLC). The goal of this study was to determine which of these three techniques delivers an optimal dose to the breast with the least chance of causing a fatal, secondary, radiation-induced cancer. A conventional, non-IMRT, 'Wedge' plan also was compared. Computerized Tomography (CT) data sets for both a large and small sized patient were used in this study. With Varian's Eclipse AAA algorithm, the organ doses specified in the revised ICRP 60 publication were used to calculate the whole-body dose. Also, an anthropomorphic phantom was irradiated with thermoluminescent dosimeters (TLD) at each organ site for measured doses. The risk coefficient from the Biological Effects of Ionizing Radiation (BEIR) VII report of 4.69 x 10-2 deaths per Gy was used to convert whole-body dose to risk of a fatal, secondary, radiation-induced cancer. The FMLC IMRT delivered superior tumor coverage over the 3D conventional plan and the inverse DMLC or SMLC treatment plans delivered clinically equivalent tumor coverage. However, the FMLC plan had the least likelihood of inadvertently causing a fatal, secondary, radiation-induced cancer compared to the inverse DMLC, SMLC, and Wedge plans.

  13. Scientific uncertainties associated with risk assessment of radiation

    International Nuclear Information System (INIS)

    Hubert, P.; Fagnani, F.

    1989-05-01

    The proper use and interpretation of data pertaining to biological effects of ionizing radiations is based on a continuous effort to discuss the various assumptions and uncertainties in the process of risk assessment. In this perspective, it has been considered useful by the Committee to review critically the general scientific foundations that constitute the basic framework of data for the evaluation of health effects of radiation. This review is an attempt to identify the main sources of uncertainties, to give, when possible, an order of magnitude for their relative importance, and to clarify the principal interactions between the different steps of the process of risk quantification. The discussion has been restricted to stochastic effects and especially to cancer induction in man: observations at the cellular levels and animal and in vitro experiments have not been considered. The consequences which might result from abandoning the hypothesis of linearity have not been directly examined in this draft, especially in respect to the concept of collective dose. Since another document dealing with 'Dose-response relationships for radiation-induced cancer' is in preparation, an effort has been made to avoid any overlap by making reference to that document whenever necessary

  14. Risk management strategies for the radon paradox in radiation protection

    International Nuclear Information System (INIS)

    Poffijn, A.; Eggermont, G.X.; Van Deynse, A.

    1996-01-01

    Indoor radon is recognised as being the most important radiation burden for the general public. In Belgium, as in many other countries, exposure levels giving rise to yearly risks of more than 10 -2 have been found. This latter value is normally considered unacceptable for the public. Moreover, an important fraction of the population lives in houses with radon levels of more than 400 Bq.m -3 , representing a risk level of 10 -3 per year or more. A level of this order is the limit for authorised and regulated activities at work. Prevention and intervention opportunities exist for these situations. The dose reduction opportunities are limited, but higher than the total collective dose in all nuclear activities. The analysis of radiation protection approaches, communication and decision-making for radon, compared to nuclear industrial activities shows incoherence at different levels. As a first attempt to develop a rational and coherent approach, cost-benefit analysis was applied to radon. Four optimisation scenarios were developed: three remediation and one about prevention. Referring to the α values applied by radiation protection authorities in France, Sweden and the Netherlands, the different scenarios are found to be highly justified. (author)

  15. Scientific uncertainties associated with risk assessment of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, P; Fagnani, F

    1989-05-01

    The proper use and interpretation of data pertaining to biological effects of ionizing radiations is based on a continuous effort to discuss the various assumptions and uncertainties in the process of risk assessment. In this perspective, it has been considered useful by the Committee to review critically the general scientific foundations that constitute the basic framework of data for the evaluation of health effects of radiation. This review is an attempt to identify the main sources of uncertainties, to give, when possible, an order of magnitude for their relative importance, and to clarify the principal interactions between the different steps of the process of risk quantification. The discussion has been restricted to stochastic effects and especially to cancer induction in man: observations at the cellular levels and animal and in vitro experiments have not been considered. The consequences which might result from abandoning the hypothesis of linearity have not been directly examined in this draft, especially in respect to the concept of collective dose. Since another document dealing with 'Dose-response relationships for radiation-induced cancer' is in preparation, an effort has been made to avoid any overlap by making reference to that document whenever necessary.

  16. Radiation risk, medical surveillance programme and radiation protection in mining and milling of uranium ores

    International Nuclear Information System (INIS)

    Rakshit, A.K.

    1991-01-01

    Mining and milling of uranium ores comprise multiple operations such as developement, drilling, blasting, handling, crushing, grinding, leaching of the ore and concentration, drying, packaging and storing of the concentrate product. Apart from the hazards of any metal mining and milling operations due to dust, noise, chemicals, accidents etc there are radiation risks also resulting from exposure to airborne radioactivity and external radiation. The inhalation risk is of more concern in underground mines than in open pit mines. The objective of a Medical Surveillance Programme (an occupational Health Programme) is to ensure a healthy work force. It should ultimately lead to health maintenance and improvement, less absenteeism increased productivity and the achievement of worker and corporate goals. The programme includes prevention, acute care, counselling and rehabilitation. Radiological workers require special monitoring for their work-related radiation exposure effect by film monitoring service, whole body counting and bioassay. Radiation protection in the mining and milling of Uranium ores include the use of personal protective equipment, work station protection, personal hygiene and house keeping. (author). 15 refs

  17. Life after Chernobyl. Radiation burden - radiation effects - risks. Leben nach Tschernobyl. Belastung - Wirkung - Risiko

    Energy Technology Data Exchange (ETDEWEB)

    Haury, H J; Ullmann, C

    1986-01-01

    The book is intended to help dissolving the feelings of helplessness and discomfiture among the population, by providing the information needed to avoid unnecessary worries, and to take the right decisions. The authors have collected the scientific knowledge available today of radioactive radiation and its effects on the biological environment and the human body. Taking into account the measured data and other insight obtained from previous accidents like the one at Seveso, e.g., or from the atmospheric nuclear weapons tests and the resulting fallout, the authors present advice and proposals that have been weighed with a view to a reasonable risk-benefit relation. The authors think that a well-informed person can today assess his own personal radiation risk after careful consideration of personal habits, and keep the radiation burden as low as possible. Apart from the variety of practical hints and advice given, the authors also discuss the confusion created by officials and authorities through their meager information policy, which finally led to the credibility gap in public opinion. The book is completed by an annex containing a survey of the Atomic Energy Laws, the Radiation Protection Ordinance, resolutions of the Strahlenschutzkommission (SSK), a literature index, and a comprehensive subject index.

  18. [Mobile phones radiate--risk to the health?].

    Science.gov (United States)

    Jokela, Kari; Auvinen, Anssi; Hämäläinen, Heikki

    2011-01-01

    The mobile phones radiate electromagnetic energy which is partly absorbed into the tissues in the vicinity of the phone. The minor heating, in maximum up to 0.3 degrees C, may cause some alterations in the expression of genes and proteins similar to physiological response to other stimuli. Biophysical studies at the cellular and molecular level have not revealed any well established interaction mechanism, through which mobile phone radiation could induce toxic effects below the thermal effect level. Research results on various biological effects in vitro and in vivo are continuously published but there is no consistent evidence on well established harmful effects. The mobile phone radiation is not carcinogenic for experimental animals or genotoxic for cells. According to epidemiological studies and psychophysiological brain function studies the use of mobile phones does not seem to increase the risk of tumors in the head and brain or disturb the function of central nervous system. However, there is a need for more research on the long-term effects of mobile phone radiation particularly on children.

  19. Patient absorbed dose and radiation risk in nuclear medicine

    International Nuclear Information System (INIS)

    Hetherington, E.; Cochrane, P.

    1992-01-01

    Since the introduction of technetium-99m labelled radiopharmaceuticals used as imaging agents in the nuclear medicine departments of Australian hospitals, patients have voiced concern about the effect of having radioactive materials injected into their bodies. The danger of X-ray exposure is widely known and well accepted, as is exposure to ultrasound, computed tomography scans and other imaging techniques. However, radioactivity is an unknown, and fear of the unknown can occasionally lead to patients refusing to undergo a nuclear medicine procedure. The authors emphasised that the radiation dose to a patient from a typical procedure would depend on the patient's medical history and treatment; the average dose being approximately 50 times the exposure received from the natural environmental background radiation. Furthermore, over an extended period the body can repair most minor damage caused by radiation, just as the body can repair the damage caused by sunburn resulting from too much exposure to sunlight. The risk of genetic effects as a result of a medical radiation dose is than very small

  20. Prostate Cancer Radiation Therapy and Risk of Thromboembolic Events

    Energy Technology Data Exchange (ETDEWEB)

    Bosco, Cecilia, E-mail: Cecilia.t.bosco@kcl.ac.uk [Translational Oncology & Urology Research (TOUR), Division of Cancer Studies, King' s College London, London (United Kingdom); Garmo, Hans [Translational Oncology & Urology Research (TOUR), Division of Cancer Studies, King' s College London, London (United Kingdom); Regional Cancer Centre, Uppsala, Akademiska Sjukhuset, Uppsala (Sweden); Adolfsson, Jan [CLINTEC Department, Karolinska Institutet, Stockholm (Sweden); Stattin, Pär [Department of Surgical Sciences, Uppsala University, Uppsala (Sweden); Department of Surgical and Perioperative Sciences, Urology and Andrology, Umeå University, Umeå (Sweden); Holmberg, Lars [Translational Oncology & Urology Research (TOUR), Division of Cancer Studies, King' s College London, London (United Kingdom); Regional Cancer Centre, Uppsala, Akademiska Sjukhuset, Uppsala (Sweden); Department of Surgical Sciences, Uppsala University, Uppsala (Sweden); Nilsson, Per; Gunnlaugsson, Adalsteinn [Department of Hematology, Oncology and Radiation Physics, Skane University Hospital, Lund University, Lund (Sweden); Widmark, Anders [Department of Radiation Sciences, Oncology, Umeå University, Umeå (Sweden); Van Hemelrijck, Mieke [Translational Oncology & Urology Research (TOUR), Division of Cancer Studies, King' s College London, London (United Kingdom); Institute of Environmental Medicine, Karolinska Institute, Stockholm (Sweden)

    2017-04-01

    Purpose: To investigate the risk of thromboembolic disease (TED) after radiation therapy (RT) with curative intent for prostate cancer (PCa). Patients and Methods: We identified all men who received RT as curative treatment (n=9410) and grouped according to external beam RT (EBRT) or brachytherapy (BT). By comparing with an age- and county-matched comparison cohort of PCa-free men (n=46,826), we investigated risk of TED after RT using Cox proportional hazard regression models. The model was adjusted for tumor characteristics, demographics, comorbidities, PCa treatments, and known risk factors of TED, such as recent surgery and disease progression. Results: Between 2006 and 2013, 6232 men with PCa received EBRT, and 3178 underwent BT. A statistically significant association was found between EBRT and BT and risk of pulmonary embolism in the crude analysis. However, upon adjusting for known TED risk factors these associations disappeared. No significant associations were found between BT or EBRT and deep venous thrombosis. Conclusion: Curative RT for prostate cancer using contemporary methodologies was not associated with an increased risk of TED.

  1. Prostate Cancer Radiation Therapy and Risk of Thromboembolic Events

    International Nuclear Information System (INIS)

    Bosco, Cecilia; Garmo, Hans; Adolfsson, Jan; Stattin, Pär; Holmberg, Lars; Nilsson, Per; Gunnlaugsson, Adalsteinn; Widmark, Anders; Van Hemelrijck, Mieke

    2017-01-01

    Purpose: To investigate the risk of thromboembolic disease (TED) after radiation therapy (RT) with curative intent for prostate cancer (PCa). Patients and Methods: We identified all men who received RT as curative treatment (n=9410) and grouped according to external beam RT (EBRT) or brachytherapy (BT). By comparing with an age- and county-matched comparison cohort of PCa-free men (n=46,826), we investigated risk of TED after RT using Cox proportional hazard regression models. The model was adjusted for tumor characteristics, demographics, comorbidities, PCa treatments, and known risk factors of TED, such as recent surgery and disease progression. Results: Between 2006 and 2013, 6232 men with PCa received EBRT, and 3178 underwent BT. A statistically significant association was found between EBRT and BT and risk of pulmonary embolism in the crude analysis. However, upon adjusting for known TED risk factors these associations disappeared. No significant associations were found between BT or EBRT and deep venous thrombosis. Conclusion: Curative RT for prostate cancer using contemporary methodologies was not associated with an increased risk of TED.

  2. Risks to health from radiation at low dose rates

    International Nuclear Information System (INIS)

    Gentner, N.E.; Osborne, R.V.

    1997-01-01

    Our focus is on whether, using a balance-of-evidence approach, it is possible to say that at a low enough dose, or at a sufficiently low dose rate, radiation risk reduces to zero in a population. We conclude that insufficient evidence exists at present to support such a conclusion. In part this reflects statistical limitations at low doses, and in part (although mechanisms unquestionably exist to protect us against much of the damage induced by ionizing radiation) the biological heterogeneity of human populations, which means these mechanisms do not act in all members of the population at all times. If it is going to be possible to demonstrate that low doses are less dangerous than we presently assume, the evidence, paradoxically, will likely come from studies of higher dose and dose rate scenarios than are encountered occupationally. (author)

  3. Literature search on risks related to ionizing radiations

    International Nuclear Information System (INIS)

    Abou Anoma, G.; Bijaoui, A.; Gauron, C.

    2013-09-01

    The authors propose a selection of information sources regarding risks related to ionizing radiations. They present knowledge bases which can be found on different Internet sites belonging to different bodies and agencies (IRSN, CEA, INRS, SFRP, CNRS, Radioprotection Cirkus, EDF) and in different books. They present information sources dealing with radionuclides which can be found in French and international Internet sites and in books, information sources concerning different professional activities and sectors (ASN, IRSN, INRS, medical-professional sheets proposed by the CISME, sheets proposed by the Labour Ministry and other bodies). It presents information sources dealing with radiological incidents, accidents and emergencies, dealing with radioactive wastes, with the legal European and French framework. Some additional tools of general or more detailed information are indicated (CIPR, IAEA, UNSCAR, IRPA, IRSN, SFRP, CEA, CEPN, Radiation Cirkus, books). Ways to get an updated search are indicated for different databases, as well as some practical services

  4. Radiation exposure and risk assessment for critical female body organs

    International Nuclear Information System (INIS)

    Atwell, W.; Weyland, M.D.; Hardy, A.C.

    1991-07-01

    Space radiation exposure limits for astronauts are based on recommendations of the National Council on Radiation Protection and Measurements. These limits now include the age at exposure and sex of the astronaut. A recently-developed computerized anatomical female (CAF) model is discussed in detail. Computer-generated, cross-sectional data are presented to illustrate the completeness of the CAF model. By applying ray-tracing techniques, shield distribution functions have been computed to calculate absorbed dose and dose equivalent values for a variety of critical body organs (e.g., breasts, lungs, thyroid gland, etc.) and mission scenarios. Specific risk assessments, i.e., cancer induction and mortality, are reviewed. 13 refs

  5. Are passive smoking, air pollution and obesity a greater mortality risk than major radiation incidents?

    Directory of Open Access Journals (Sweden)

    Smith Jim T

    2007-04-01

    Full Text Available Abstract Background Following a nuclear incident, the communication and perception of radiation risk becomes a (perhaps the major public health issue. In response to such incidents it is therefore crucial to communicate radiation health risks in the context of other more common environmental and lifestyle risk factors. This study compares the risk of mortality from past radiation exposures (to people who survived the Hiroshima and Nagasaki atomic bombs and those exposed after the Chernobyl accident with risks arising from air pollution, obesity and passive and active smoking. Methods A comparative assessment of mortality risks from ionising radiation was carried out by estimating radiation risks for realistic exposure scenarios and assessing those risks in comparison with risks from air pollution, obesity and passive and active smoking. Results The mortality risk to populations exposed to radiation from the Chernobyl accident may be no higher than that for other more common risk factors such as air pollution or passive smoking. Radiation exposures experienced by the most exposed group of survivors of Hiroshima and Nagasaki led to an average loss of life expectancy significantly lower than that caused by severe obesity or active smoking. Conclusion Population-averaged risks from exposures following major radiation incidents are clearly significant, but may be no greater than those from other much more common environmental and lifestyle factors. This comparative analysis, whilst highlighting inevitable uncertainties in risk quantification and comparison, helps place the potential consequences of radiation exposures in the context of other public health risks.

  6. Radiation dose and cancer risk to children undergoing skull radiography

    International Nuclear Information System (INIS)

    Mazonakis, Michael; Damilakis, John; Raissaki, Maria; Gourtsoyiannis, Nicholas

    2004-01-01

    Background: Limited data exist in the literature concerning the patient-effective dose from paediatric skull radiography. No information has been provided regarding organ doses, patient dose during PA skull projection, risk of cancer induction and dose to comforters, i.e. individuals supporting children during exposure. Objective: To estimate patient-effective dose, organ doses, lifetime cancer mortality risk to children and radiation dose to comforters associated with skull radiography. Materials and methods: Data were collected from 136 paediatric examinations, including AP, PA and lateral skull radiographs. Entrance-surface dose (ESD) and dose to comforters were measured using thermoluminescent dosimeters. Patients were divided into the following age groups: 0.5-2, 3-7, 8-12 and 13-18 years. The patient-effective dose and corresponding organ doses were calculated using data from the NRPB and Monte Carlo techniques. The risk for fatal cancer induction was assessed using appropriate risk coefficients. Results: For AP, PA and lateral skull radiography, effective dose ranges were 8.8-25.4, 8.2-27.3 and 8.4-22.7 μSv respectively, depending upon the age of the child. For each skull projection, the organs receiving doses above 10 μGy are presented. The number of fatal cancers was found to be less than or equal to 2 per 1 million children undergoing a skull radiograph. The mean radiation dose absorbed by the hands of comforters was 13.4 μGy. Conclusions: The current study provides detailed tabular and graphical data on ESD, effective dose, organ doses and lifetime cancer mortality risk to children associated with AP, PA and lateral skull projections at all patient ages. (orig.)

  7. Radiation risk to patients from nuclear medicine procedures in Cuba

    International Nuclear Information System (INIS)

    Brigido, O.; Montalván, A.; Barreras, A.; Hernández, J.

    2015-01-01

    Man-made radiation exposure to the Cuban population predominantly results from the medical use of ionizing radiation. It was therefore the aim of the present study, to provide public health information concerning diagnostic nuclear medicine procedures carried out in Camagüey and Ciego de Ávila provinces between 2000 and 2005. Population radiation dose estimation due to administration of radiopharmaceuticals in Camagüey and Ciego de Ávila provinces was carried out using Medical Internal Radiation Dose scheme (MIRD). Data were gathered on the type of radiopharmaceuticals used, the administered activity, the numbers of each kind of examination, and the age and sex of the patients involved during the period 2000 – 2005. The average annual frequency of examinations was estimated to be 3.34 per 1000 population. The results show that imaging nuclear medicine techniques of thyroid and bone explorations with 13.3 and 12.9%, respectively and iodide uptake with 50% are the main techniques implicated in the relative contribution to the total annual effective collective dose which averaged 95 man⋅Sv for the studied period. Radiation risks for the Camagüey-Ciego de Avila population caused by nuclear medicine examinations in the period studied were calculated: the total number of fatal and non-fatal cancers was 34.2 and the number of serious hereditary disturbance was 7.4 as a result of 24139 nuclear medicine procedures, corresponding a total detriment of 1.72 per 1000 examination. (authors)

  8. Risk assessment and management of radiofrequency radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Dabala, Dana [Railways Medical Clinic Cluj-Napoca, Occupational Medicine Department, 16-20 Bilascu Gheorghe St., 400015 Cluj-Napoca (Romania); Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath St., 400293 Cluj-Napoca (Romania)

    2013-11-13

    Radiofrequency radiation (RFR) industry managers, occupational physicians, security department, and other practitioners must be advised on the basic of biophysics and the health effects of RF electromagnetic fields so as to guide the management of exposure. Information on biophysics of RFR and biological/heath effects is derived from standard texts, literature and clinical experiences. Emergency treatment and ongoing care is outlined, with clinical approach integrating the circumstances of exposure and the patient's symptoms. Experimental risk assessment model in RFR chronic exposure is proposed. Planning for assessment and monitoring exposure, ongoing care, safety measures and work protection are outlining the proper management.

  9. Radiation dose and risk in gastrointestinal roentgendiagnostic of the child

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, H; Loehr, H; Wallbaum, F [Hamburg Univ. (Germany, F.R.). Abt. fuer Roentgendiagnostik

    1978-11-01

    In gastrointestinal roentgendiagnostic of the child the exposure of the skin and the testis depends on body height and body weight. The dose grows with the age. The squaredose product (Rcm/sup 2/) and the energy absorbed by the body(integraldose, rdkg)increases comparably. On the other hand the quotient integraldosis/body weight is similar for the different age-groups. The radiation risk (the probability to die as consequence of a roentgenray induced disease) is approximately 1:100,000 to 1:10,000,000.

  10. Risk assessment and management of radiofrequency radiation exposure

    International Nuclear Information System (INIS)

    Dabala, Dana; Surducan, Emanoil; Surducan, Vasile; Neamtu, Camelia

    2013-01-01

    Radiofrequency radiation (RFR) industry managers, occupational physicians, security department, and other practitioners must be advised on the basic of biophysics and the health effects of RF electromagnetic fields so as to guide the management of exposure. Information on biophysics of RFR and biological/heath effects is derived from standard texts, literature and clinical experiences. Emergency treatment and ongoing care is outlined, with clinical approach integrating the circumstances of exposure and the patient's symptoms. Experimental risk assessment model in RFR chronic exposure is proposed. Planning for assessment and monitoring exposure, ongoing care, safety measures and work protection are outlining the proper management

  11. [Socio-psychological and ecological aspects within the system of nuclear radiation risk mitigation].

    Science.gov (United States)

    Davydov, B I; Ushakov, I B; Zuev, V G

    2004-01-01

    The authors bring into light several aspects of nuclear radiation risks, i.e. physical safety of nuclear technologies and ecology, place of operator within the nuclear radiation safety system (proficiency, protective culture, safety guides) and consider approaches to the human factor quantification within the system of mitigation of risks from nuclear technologies, and IAEA recommendations on probable risk estimation. Future investigations should be aimed at extension of the radiation sensitivity threshold, personnel selection as by psychological so genetic testing for immunity to ionizing radiation, development of pharmachemical and physical protectors and methods of enhancing nonspecific resistance to extreme, including radiation, environments, and building of radiation event simulators for training.

  12. Estimation of enhanced cancer risk with 18FDG PET/CT investigations

    International Nuclear Information System (INIS)

    Kaushik, Aruna; Mishra, Anil K.; Sharma, Rajnish; Mondal, Anupam; Dwarakanath, B.S.

    2014-01-01

    18 F-Fluorodeoxyglucose ( 18 FDG) Positron Emission Tomography/Computed Tomography (PET/CT) investigation involves internal administration of 18 FDG and use of CT X-rays for the purpose of obtaining functional and anatomical information of a patient. However, the radiation exposure from undergoing PET/CT investigation may enhance the risk of cancer incidence as per the Linear-No-Threshold (LNT) model. The objective of the present study was to quantify the risk of cancer incidence associated with radiation exposure from 18 FDG PET/CT investigations. The organ doses from internally administered 18 FDG were estimated using OLINDA/EXM Code by performing dynamic PET scans in different regions of the body in a total of forty-nine patients. Organ doses from the CT component were calculated using the software CT-Expo. The associated cancer risk was calculated in terms of life time risk of cancer incidence resulting from a specified dose of ionizing radiation and was expressed in terms of Lifetime Attributable Risk (LAR). LAR values and the organ doses estimated for males and females were used to estimate the lifetime risk of cancer incidence from whole body 18 FDG PET/CT scan. Since from 18 FDG whole body PET/CT investigations, various tissues of the body receive substantially different doses, the site specific risk of cancer incidence was estimated and summed to obtain the total risk. This was compared with the baseline lifetime risk of cancer incidence in Indian population. LAR of cancer incidence was observed to be relatively higher in females as compared to males. The risk estimates ranged from 0.36% to 0.49% for a 20 year old male and 0.58% to 0.79% for a 20 year old female and were observed to be higher in younger ages and decreased with age. 18 FDG whole body PET/CT investigation was observed to be associated with non-negligible radiation risk as compared to the risks associated with other diagnostic modalities. (author)

  13. The report of the French Academy of Science: 'Problems associated with the effects of low doses of ionising radiation'

    International Nuclear Information System (INIS)

    Tubiana, M.

    1998-01-01

    In 1995 the French Academy of Science published a report on 'Problems associated with low doses of ionising radiation'. This report aroused interest among French-speaking scientists and a translation in English was published a year later. The report pointed out that an important issue in radioprotection was not whether to accept or reject the linear no-threshold model but rather to test its validity. The aim of this review is to analyse the report and its recommendations, and to briefly indicate the progress which has been made and the questions which remain open. Three areas of the report are covered in this review: DNA repair, carcinogenesis and epidemiological data. (author)

  14. Dose dependence on stochastic radiobiological effect in radiation risk estimation

    International Nuclear Information System (INIS)

    Komochkov, M.M.

    1999-01-01

    The analysis of the results in dose -- effect relationship observation has been carried out on the cell and organism levels, with the aim to obtain more precise data on the risk coefficients at low doses. The results are represented by two contrasting groups of dose dependence on effect: a downwards concave and a J-shaped curve. Both types of dependence are described by the equation solutions of an assumed unified protective mechanism, which comprises two components: constitutive and adaptive or inducible ones. The latest data analysis of the downwards concave dependence curves shows a considerable underestimation of radiation risk in all types of cancer, except leukemia, for a number of critical groups in a population, at low doses comparing to the ICRP recommendations. With the dose increase, the decrease of the effect value per dose unit is observed. It may be possibly related to the switching of the activity of the adaptive protective mechanism, with some threshold dose values being exceeded

  15. Evaluation of radiation risk and work practices during cerebral interventions

    Energy Technology Data Exchange (ETDEWEB)

    Livingstone, Roshan S; Raghuram, L; Korah, Ipeson P; Raj, D Victor [Department of Radiodiagnosis, Christian Medical College, Vellore 632004 (India)

    2003-09-01

    This study was intended to evaluate radiation risk to patients during cerebral interventions and the contribution to this risk from work practices. Thirty nine patients undergoing cerebral interventions in a digital subtraction angiography suite were included in this study. Patients who underwent cerebral interventions were categorised into two groups according to the number of cerebral interventions performed on them, and their effective doses were calculated. The effective dose for patients undergoing a single cerebral intervention (group A) varied from 1.55 to 15.9 mSv and for multiple cerebral interventions (group B) varied from 16.52 to 43.52 mSv. Two patients who underwent multiple cerebral interventions (group B) had alopecia of the irradiated scalp.

  16. Predictions of space radiation fatality risk for exploration missions.

    Science.gov (United States)

    Cucinotta, Francis A; To, Khiet; Cacao, Eliedonna

    2017-05-01

    In this paper we describe revisions to the NASA Space Cancer Risk (NSCR) model focusing on updates to probability distribution functions (PDF) representing the uncertainties in the radiation quality factor (QF) model parameters and the dose and dose-rate reduction effectiveness factor (DDREF). We integrate recent heavy ion data on liver, colorectal, intestinal, lung, and Harderian gland tumors with other data from fission neutron experiments into the model analysis. In an earlier work we introduced distinct QFs for leukemia and solid cancer risk predictions, and here we consider liver cancer risks separately because of the higher RBE's reported in mouse experiments compared to other tumors types, and distinct risk factors for liver cancer for astronauts compared to the U.S. The revised model is used to make predictions of fatal cancer and circulatory disease risks for 1-year deep space and International Space Station (ISS) missions, and a 940 day Mars mission. We analyzed the contribution of the various model parameter uncertainties to the overall uncertainty, which shows that the uncertainties in relative biological effectiveness (RBE) factors at high LET due to statistical uncertainties and differences across tissue types and mouse strains are the dominant uncertainty. NASA's exposure limits are approached or exceeded for each mission scenario considered. Two main conclusions are made: 1) Reducing the current estimate of about a 3-fold uncertainty to a 2-fold or lower uncertainty will require much more expansive animal carcinogenesis studies in order to reduce statistical uncertainties and understand tissue, sex and genetic variations. 2) Alternative model assumptions such as non-targeted effects, increased tumor lethality and decreased latency at high LET, and non-cancer mortality risks from circulatory diseases could significantly increase risk estimates to several times higher than the NASA limits. Copyright © 2017 The Committee on Space Research (COSPAR

  17. A method to adjust radiation dose-response relationships for clinical risk factors

    DEFF Research Database (Denmark)

    Appelt, Ane Lindegaard; Vogelius, Ivan R

    2012-01-01

    Several clinical risk factors for radiation induced toxicity have been identified in the literature. Here, we present a method to quantify the effect of clinical risk factors on radiation dose-response curves and apply the method to adjust the dose-response for radiation pneumonitis for patients...

  18. A proposed methodology for performing risk analysis of state radiation control programs

    International Nuclear Information System (INIS)

    Dornsife, W.P.

    1996-01-01

    This paper is comprised of viewgraphs from a conference presentation. Topics discussed include barriers to effective risk assessment and management, and real versus perceived risk for various radiation programs in the state of Pennsylvania. Calculation results for Pennsylvania are provided for low-level radioactive waste transportation risks, indoor radon risk, and cancer morbidity risk from x-rays. A methodology for prioritizing radiation regulatory programs based on risk is presented with calculations for various Pennsylvania programs

  19. Estimation of radiation cancer risk in CT-KUB

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Bradley, D. A.; Ang, W. C.; Bahrudin, N. A.; Mhareb, M. H. A.

    2017-08-01

    The increased demand for computed tomography (CT) in radiological scanning examinations raises the question of a potential health impact from the associated radiation exposures. Focusing on CT kidney-ureter-bladder (CT-KUB) procedures, this work was aimed at determining organ equivalent dose using a commercial CT dose calculator and providing an estimate of cancer risks. The study, which included 64 patients (32 males and 32 females, mean age 55.5 years and age range 30-80 years), involved use of a calibrated CT scanner (Siemens-Somatom Emotion 16-slice). The CT exposures parameter including tube potential, pitch factor, tube current, volume CT dose index (CTDIvol) and dose-length product (DLP) were recorded and analyzed using CT-EXPO (Version 2.3.1, Germany). Patient organ doses, including for stomach, liver, colon, bladder, red bone marrow, prostate and ovaries were calculated and converted into cancer risks using age- and sex-specific data published in the Biological Effects of Ionizing Radiation (BEIR) VII report. With a median value scan range of 36.1 cm, the CTDIvol, DLP, and effective dose were found to be 10.7 mGy, 390.3 mGy cm and 6.2 mSv, respectively. The mean cancer risks for males and females were estimated to be respectively 25 and 46 out of 100,000 procedures with effective doses between 4.2 mSv and 10.1 mSv. Given the increased cancer risks from current CT-KUB procedures compared to conventional examinations, we propose that the low dose protocols for unenhanced CT procedures be taken into consideration before establishing imaging protocols for CT-KUB.

  20. Epistemological problems in assessing cancer risks at low radiation doses

    International Nuclear Information System (INIS)

    Walinder, G.

    1987-01-01

    Historically, biology has not been subjected to any epistemological analysis as has been the case with mathematics and physics. Our knowledge of the effects in biological systems of various stimuli proves to be dualistic in a complementary (although not mutually exclusive) way, which bears resemblance to the knowledge of phenomena in quantum physics. The dualistic limbs of biological knowledge are the action of stimuli and the response of the exposed, biological system. With regard to radiogenic cancer, this corresponds to the action of the ionizations and the response of the exposed mammal to that action, respectively. The following conclusions can be drawn from the present analysis: Predictions as to radiogenic cancer seem often if not always to have neglected the response variability (variations in radiosensitivity) in individuals or among individuals in populations, i.e. the predictions have been based exclusively on radiation doses and exposure conditions. The exposed individual or population, however, must be considered an open statistical system, i.e. a system in which predictions as to the effect of an agent are only conditionally possible. The knowledge is inverse to the size of the dose or concentration of the active agent. On epistemological grounds, we can not gain knowledge about the carcinogenic capacity of very low (non-dominant) radiation doses. Based on the same principle, we can not predict cancer risks at very low (non-dominant) radiation doses merely on the basis of models, or otherwise interpolated or extrapolated high-dose effects, observed under special exposure conditions

  1. Risk estimation of radiation exposure in early pregnancy

    International Nuclear Information System (INIS)

    Neumeister, K.; Waesser, S.

    1977-01-01

    The biomedical effects of radiation exposure (occupational, by X-ray diagnosis or examinations in nuclear medicine) to low doses on early pregnancy have been subject of a research work dealing with the dose level which, in case of exceeding, may lead to somatic damage (1.5 to 10 rem), and with the type of radiation injuries (malformations, functional disorder, cancer induction, increase in morbidity rate, genetic damage). A pilot study was the basis for the programme which will record such cases from all over the GDR. Within the scope of the health centre at the National Board of Nuclear Safety and Radiation Protection of the GDR, medical opinion on the interruption or preservation of pregnancy at its early stage, after exposure, was delivered in more than 50 cases. Exposure of the foetus was exactly determined. These children were re-investigated at the age of 1 to 3 years by applying pediatric and genetic examinations. The latter were based on clinical and biochemical methods as well as chromosome analyses. From these results, the risk of exposure in early pregnancy is estimated and adequate dose limits are suggested. In case these limits are exceeded, an interruption should be advised

  2. Risk evaluation - conventional and low level effects of radiation

    International Nuclear Information System (INIS)

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

    1984-04-01

    Any discussion of the risk of exposure to potentially-hazardous agents in the environment inevitably involves the question of whether the dose effect curve is of the threshold or linear, non-threshold type. A principal objective of this presentation is to show that the function is actually two separate relationships, each representing distinctly different functions with differing variables on the axes, and each characteristic of quite different functions with differing variables on the axes, and each characteristic of quite different disciplines (i.e., the threshold function, of Pharmacology, Toxicology and Medicine [PTM]; the linear, non-threshold function, of Public Health including safety and accident statistics [PHS]). It is shown that low-level exposure (LLE) to radiation falls clearly in the PHS category. A function for cell dose vs. the fraction of single cell quantal responses is characterized, which reflects the absolute and relative sensitivities of cells. Acceptance of this function would obviate any requirement for the use in Radiation Protection of the concepts of a standard radiation, Q, dose equivalent and rem. 9 references, 4 figures

  3. Provenance of nuclear radioactivity radiation and hazardous health risks

    International Nuclear Information System (INIS)

    Sakhuja, Geeta

    2016-01-01

    This assessment has an important consideration for nuclear energy upon the creation of radioactivity being generated and mobilized through various energy agencies. The term 'Radioactivity' or the rate of nuclear decay is measured in units called 'Becquerel' (Bq), where 1 Bq= 1 event (disintegration) per second. Another commonly used unit of radioactivity is the Curie (Ci), where 1 Ci = 3.70 x 10"1"0 Bq. Radiation is all around us. It is in our environment and has been since the earth was formed. As a result, life has evolved in the presence of significant levels of ionizing radiation. It comes from outer space (cosmic), ground (terrestrial) and even from within our own bodies. It is in the air we breathe, the food we eat, the water we drink, and the state of our wellbeing. However, the entire system is related to human and human-health issues. This paper examines the empirical evidence incorporated with human-made nuclear radioactivity from nuclear energy sources, especially while maintaining the viability of radioactive mechanisms, which may cause the uncontrolled highly dangerous harmful effects of radionuclides in human body and these radiations can even damage the DNA in the cells of people when exposed to it, because it is the DNA that passes on instructions for growth and development to the next generation. This, in turn, is the paradigm for the health risks of various sources of nuclear radioactivity. (author)

  4. An estimate of the radiation-induced cancer risk from the whole-body stray radiation exposure in neutron radiotherapy

    International Nuclear Information System (INIS)

    Geraci, J.P.; Jackson, K.L.; Mariano, M.S.

    1982-01-01

    1980 BEIR III risk factors have been used to estimate the secondary cancer risks from the whole-body stray radiation exposures occurring in neutron radiotherapy. Risks were calculated using linear, linear-quadratic and quadratic dose-response models for the gamma component of the stray radiation. The linear dose-response model was used to calculate risk for the neutron component of the stray radiation. These estimates take into consideration for the first time the age and sex distribution of patients undergoing neutron therapy. Changes in risk as a function of the RBE (10-100) assigned to the stray neutron radiation component have also been assessed. Excess risks in neutron-treated patients have been compared with excess risks for photon-treated patients and with the expected incidence of cancer in a normal population having the same age and sex distribution. Results indicate that it will be necessary to tolerate a higher incidence of secondary cancers in patients undergoing fast neutron therapy than is the case with conventional photon therapy. For neutron RBEs of less than 50 the increased risk is only a fraction of the normal expected incidence of cancer in this population. Comparison of the radiation-induced risk with reported normal tissue complication rates in the treatment volume indicates that the excess cancer risk is substantially lower than the risk from other late normal tissue effects. (author)

  5. Multicomponent risk inherent to nuclear or radiation accidents

    International Nuclear Information System (INIS)

    Poyarkov, V.A.

    1997-01-01

    A nuclear or radiation emergency response planning is based on expected avertable doses for a short (4 hours, 2 days, 1 week) and a long (50 or 70 years) periods of time. On calculating the doses one should take into account not only the sources of ionizing radiation with their foreseen characteristics, e.g. a half-life, but also the possibility of their probabilistic transformations. It can be illustrated by the chronicle of Chernobyl accident, where for nine days it was impossible to envisage with reliability the quantities of released radionuclides due to many uncontrolled factors related to the scope and character of the zone wreckage. Any other developments of the accident, such as destruction of the under reactor support plate, sinking of the melted zone into a highly radioactive water down at the reactor cavity or changing of the wind could have resulted in a substantial contamination of 3 mln. Kiev and other densely populated area of Ukraine. Another factor to be taken into account in the emergency response is a way of an actual risk perception by the population. The article suggests an approach to take into account the time-dependent secondary sources of exposure and the disparity in accepting the hazard of real risk of an accident by the trained workers and population. (author)

  6. Uncertainties in fatal cancer risk estimates used in radiation protection

    International Nuclear Information System (INIS)

    Kai, Michiaki

    1999-01-01

    Although ICRP and NCRP had not described the details of uncertainties in cancer risk estimates in radiation protection, NCRP, in 1997, firstly reported the results of uncertainty analysis (NCRP No.126) and which is summarized in this paper. The NCRP report pointed out that there are following five factors which uncertainty possessing: uncertainty in epidemiological studies, in dose assessment, in transforming the estimates to risk assessment, in risk prediction and in extrapolation to the low dose/dose rate. These individual factors were analyzed statistically to obtain the relationship between the probability of cancer death in the US population and life time risk coefficient (% per Sv), which showed that, for the latter, the mean value was 3.99 x 10 -2 /Sv, median, 3.38 x 10 -2 /Sv, GSD (geometrical standard deviation), 1.83 x 10 -2 /Sv and 95% confidential limit, 1.2-8.84 x 10 -2 /Sv. The mean value was smaller than that of ICRP recommendation (5 x 10 -2 /Sv), indicating that the value has the uncertainty factor of 2.5-3. Moreover, the most important factor was shown to be the uncertainty in DDREF (dose/dose rate reduction factor). (K.H.)

  7. Cardiovascular risks associated with low dose ionizing particle radiation.

    Directory of Open Access Journals (Sweden)

    Xinhua Yan

    Full Text Available Previous epidemiologic data demonstrate that cardiovascular (CV morbidity and mortality may occur decades after ionizing radiation exposure. With increased use of proton and carbon ion radiotherapy and concerns about space radiation exposures to astronauts on future long-duration exploration-type missions, the long-term effects and risks of low-dose charged particle irradiation on the CV system must be better appreciated. Here we report on the long-term effects of whole-body proton ((1H; 0.5 Gy, 1 GeV and iron ion ((56Fe; 0.15 Gy, 1GeV/nucleon irradiation with and without an acute myocardial ischemia (AMI event in mice. We show that cardiac function of proton-irradiated mice initially improves at 1 month but declines by 10 months post-irradiation. In AMI-induced mice, prior proton irradiation improved cardiac function restoration and enhanced cardiac remodeling. This was associated with increased pro-survival gene expression in cardiac tissues. In contrast, cardiac function was significantly declined in (56Fe ion-irradiated mice at 1 and 3 months but recovered at 10 months. In addition, (56Fe ion-irradiation led to poorer cardiac function and more adverse remodeling in AMI-induced mice, and was associated with decreased angiogenesis and pro-survival factors in cardiac tissues at any time point examined up to 10 months. This is the first study reporting CV effects following low dose proton and iron ion irradiation during normal aging and post-AMI. Understanding the biological effects of charged particle radiation qualities on the CV system is necessary both for the mitigation of space exploration CV risks and for understanding of long-term CV effects following charged particle radiotherapy.

  8. MDS. A disease with high radiation-risk

    International Nuclear Information System (INIS)

    Ban, Sadayuki; Sudo, Hitomi; Saegusa, Kumiko; Sagara, Masashi; Imai, Takashi

    2003-01-01

    A preliminary epidemiological study demonstrated that myelodysplastic syndrome (MDS) has an excess relative risk per sievert of 13 in atomic bomb survivors. MDS is the only other radiogenic blood disease apart from leukemia. Clinically, MDS involves dysplastic hematopoiesis and an increased risk of leukemic transformation. Because it is uncertain whether MDS pathogenesis affects lymphoid progenitor cells as well as myeloid progenitor cells, we investigated the micronucleus (MN) frequency in peripheral T lymphocytes of twenty-three atomic bomb survivors with MDS and five normal individuals. The spontaneous- and X-ray-induced-MN frequencies were significantly higher in MDS patients than in normal individuals. Interestingly, radiation sensitivity increased along with the severity of MDS clinical subtypes. Because many of the patients in this study had not been exposed to chemo- or radiation-therapy, their unusual radiosensitivities may be related to their chromosomal or genomic instability. To explain the cause of unusual radiosensitivity, we measured the expression levels of four nucleotide excision repair (NER) genes (ERCC1, ERCC3, ERCC5 and XPC) in peripheral blood mononuclear cells using a reverse transcripts-polymerase chain reaction (RT-PCR) method. The ERCC5 gene was expressed at reduced levels in only one of 10 patients with mild symptom. Reduction of NER genes was expressed in four of 11 patients with severe symptom. Immortalized lymphoid cell lines were established from B-lymphocytes infected with Epstein-Barr virus in vitro. The abrogation of radiation-induced-G2/M arrnst was observed in some of MDS-B lymphoid cell lines, but not in the normal B lymphoid cell lines. Our data suggest that the control of chromosomal stability is impaired in pluripotent stem cells of MDS patients, and that DNA repair defects and loss of G2/M arrest may be involved in the pathophysiology of disease progression. (authors)

  9. Toxicity risk of non-target organs at risk receiving low-dose radiation: case report

    International Nuclear Information System (INIS)

    Shueng, Pei-Wei; Lin, Shih-Chiang; Chang, Hou-Tai; Chong, Ngot-Swan; Chen, Yu-Jen; Wang, Li-Ying; Hsieh, Yen-Ping; Hsieh, Chen-Hsi

    2009-01-01

    The spine is the most common site for bone metastases. Radiation therapy is a common treatment for palliation of pain and for prevention or treatment of spinal cord compression. Helical tomotherapy (HT), a new image-guided intensity modulated radiotherapy (IMRT), delivers highly conformal dose distributions and provides an impressive ability to spare adjacent organs at risk, thus increasing the local control of spinal column metastases and decreasing the potential risk of critical organs under treatment. However, there are a lot of non-target organs at risk (OARs) occupied by low dose with underestimate in this modern rotational IMRT treatment. Herein, we report a case of a pathologic compression fracture of the T9 vertebra in a 55-year-old patient with cholangiocarcinoma. The patient underwent HT at a dose of 30 Gy/10 fractions delivered to T8-T10 for symptom relief. Two weeks after the radiotherapy had been completed, the first course of chemotherapy comprising gemcitabine, fluorouracil, and leucovorin was administered. After two weeks of chemotherapy, however, the patient developed progressive dyspnea. A computed tomography scan of the chest revealed an interstitial pattern with traction bronchiectasis, diffuse ground-glass opacities, and cystic change with fibrosis. Acute radiation pneumonitis was diagnosed. Oncologists should be alert to the potential risk of radiation toxicities caused by low dose off-targets and abscopal effects even with highly conformal radiotherapy

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

    International Nuclear Information System (INIS)

    Higson, D.J.

    2006-01-01

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

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

    International Nuclear Information System (INIS)

    Pathak, C.M.; Avti, P.K.; Khanduja, K.L.; Sharma, S.C.

    2008-01-01

    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

  12. ADVISORY ON UPDATED METHODOLOGY FOR ESTIMATING CANCER RISKS FROM EXPOSURE TO IONIZING RADIATION

    Science.gov (United States)

    The National Academy of Sciences (NAS) published the Biological Effects of Ionizing Radiation (BEIR) committee's report (BEIR VII) on risks from ionizing radiation exposures in 2006. The Committee analyzed the most recent epidemiology from the important exposed cohorts and factor...

  13. Comparative risk assessment: an element for a more rational and ethical approach to radiation risk

    International Nuclear Information System (INIS)

    Danesi, P.R.

    2006-01-01

    Peaceful nuclear technologies are still perceived by a large fraction of the general public, the media as well as by some decision makers, as more risky than many other 'conventional' technologies. One of the approaches that can help bringing more rationality and ethics into the picture is to present the risk associated with radiation and nuclear technologies in the frame of correctly conducted comparative risk assessments. However, comparing different risks is not so straightforward because quantifying different risks on a comparable scale requires overcoming both conceptual and practical difficulties. Risk (R) can be expressed as the product of the probability (P) that a given undesired event, the risk, will occur, times the consequences of this event (C), i.e. R = P x C. Although in principle risks could be compared by simply ranking them according to the different values of R, this simplistic approach is not always possible because to correctly compare risks all factors, circumstances and assumptions should be mutually equivalent and quantified and the (often large) uncertainties taken into proper account. In the case of radiation risk, ICRP has assumed as valid the LNT model, (probability coefficient of 5 % per Sievert for attributable death from cancer) and selected the present equivalent dose limit of 1 mSv per year for public exposure. This dose corresponds to 50 lethal cancers by 1 million people exposed and is approximately equivalent (in terms of probability of death) to the risk of bicycling for 600 km, driving for 3200 km, crossing a busy road twice a day for 1 year, smoking 2.5 packets of cigarettes or being X-rayed once for kidney metabolism. However, according to many scientists on the basis of both epidemiological and biological results and considerations, the actual risk is far lower than that predicted by the LNT model. Nevertheless, the policies and myths that were created about half a century ago are still persisting and have lead the general

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

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1992-06-01

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

  15. Alpha-risk: a European project on the quantification of risks associated with multiple radiation exposures

    International Nuclear Information System (INIS)

    Laurier, D.; Monchaux, G.; Tirmarche, M.; Darby, S.; Cardis, E.; Binks, K.; Hofmann, W.; Muirhead, C.

    2006-01-01

    The Alpha-Risk research project is being conducted within the Sixth European Framework Programme (EC-FP6, 2005 -2008). It aims to improve the quantification of risks associated with multiple exposures, taking into account the contribution of different radionuclides and external exposure using specific organ dose calculations. The Alpha-Risk Consortium involves 18 partners from 9 countries, and is coordinated by the IRSN. Its composition allows a multidisciplinary collaboration between researchers in epidemiology, dosimetry, statistics, modelling and risk assessment. Alpha-Risk brings together major epidemiological studies in Europe, which are able to evaluate long-term health effects of internal exposure from radionuclides. It includes large size cohort and case-control studies, with accurate registration of individual annual exposures: uranium miner studies, studies on lung cancer and indoor radon exposure, and studies of lung cancer and leukaemia among nuclear workers exposed to transuranic nuclides (mainly uranium and plutonium), for whom organ doses will be reconstructed individually. The contribution of experts in dosimetry will allow the calculation of organ doses in presence of multiple exposures (radon decay products, uranium dust and external gamma exposure). Expression of the risk per unit organ dose will make it possible to compare results with those from other populations exposed to external radiation. The multidisciplinary approach of Alpha-Risk promotes the development of coherent and improved methodological approaches regarding risk modelling. A specific work - package is dedicated to the integration of results and their use for risk assessment, especially for radon. Alpha-Risk will contribute to a better understanding of long-term health risks following chronic low doses from internal exposures. The project also has the great potential to help resolve major public health concerns about the effects of low and/or protracted exposures, especially

  16. Radiation risks and monitoring of transboundary rivers of Kazakhstan

    International Nuclear Information System (INIS)

    Kadyrzhanov, K.K.; Solodukhin, V.P.; Khazhekber, S.; Poznyak, V.L.; Chernykh, E.E.; Passell, H.D.

    2006-01-01

    Full text: The condition of the water resources of the Republic of Kazakhstan is characterized with their whole deficiency as well as their high pollution and desiccation. The situation is also aggravated with much relaxation of work coordination on regulation of trans-boundary river flows and control of their water quality as a result of the USSR collapse and isolation of separate republics. The absence of objective information on water condition of rivers and their contamination sources creates a danger of high ecological risk and psychological stress for inhabitants, localities of that related to the basins of these rivers, and serves as reasoning for claims (occasionally unreasonable) to neighboring countries. Following rivers are the largest trans-boundary ones in Kazakhstan: Ile, Syrdarya, Ural and Irtysh. All these rivers are of great importance for people's life-support of the republic. At the same time presence of a number of large industrial centers, agricultural enterprises and radiation-dangerous objects in the basins of these rivers creates a potential danger of chemical and radiation contamination for their water flows. Objective information on its influence rate is required. The most acceptable form of the control of radiation and hydro-chemical situation in the basins of transboundary rivers is their monitoring based on modern nuclear-and-physical methods of analysis. Very important factor in organization of such monitoring system is participation of all the countries concerned with the basin of the river under the control. There is a work experience of many years in Central Asia on monitoring of large Syrdarya and Amudarya rivers. These works have been carried out since 2000 with the framework of the International project NAVRUZ. Participants of this project are organizations of nuclear profile from Uzbekistan, Kirghizia, Tajikistan and Kazakhstan. The collaborator of this project is the Sandia National Laboratories (SNL), USA. Experience of these

  17. Postoperative radiation for cervical cancer with pathologic risk factors

    International Nuclear Information System (INIS)

    Hart, Kimberly; Han, Ihn; Deppe, Gunter; Malviya, Vinay; Malone, John; Christensen, Carl; Chuba, Paul; Porter, Arthur

    1997-01-01

    Purpose: To examine the efficacy of postoperative radiation therapy for early-stage cervical cancer with pathologic risk factors. Methods and Materials: We reviewed the charts of 83 patients who received postoperative radiation therapy at our facility from March 1980 to November 1993 for early stage cervix cancer with positive surgical margins, positive pelvic or periaortic lymph nodes, lymphovascular space invasion, deep invasion, or for disease discovered incidentally at simple hysterectomy. Twenty-eight patients received low dose rate (LDR) intracavitary radiation with or without external beam pelvic irradiation and 55 patients received external beam pelvic irradiation with high dose rate (HDR) intracavitary implants. Of these 83 patients, 66 were evaluable--20 LDR and 46 HDR patients. All patients received 45-50 Gy external beam irradiation and 20 Gy LDR equivalent intracavitary irradiation prescribed to 0.5 cm below the mucosa. Ninety percent of the LDR group and 92% of the HDR group completed treatment within < 56 days. Treatment-related toxicities were scored according to the GOG toxicity scale. Mean and median follow-up times were 101 months and 111 months (3-172 months) for the LDR group and 42 and 40 months (3-98 months) for the HDR group. Results: The 5-year disease-free survival was 89% for the LDR group and 72% for the HDR group. Local control was observed in 90% (18 out of 20) of the LDR patients and 89% (41 out of 46) of the HDR patients for an overall local control rate of 89.5%. Two of 20 LDR patients (10%) experienced recurrence (two pelvic with distant metastasis). Nine of 46 HDR patients (22%) had recurrence of disease (three pelvic, four distant metastasis, and two pelvic with distant metastasis). In the HDR group, 6 out of 16 (38%) with positive lymph nodes died of disease whereas, 27 out of 30 (90%) of the patients with negative lymph nodes remain free of disease. Three of 20 (15%) LDR patients and 4 out of 46 (9%) HDR patients experienced

  18. Calculation of the quantities of radiation risk in Japanese population

    International Nuclear Information System (INIS)

    Nakamura, Yuji

    1993-01-01

    The purpose of this study was to reevaluate various kinds of indicators of radiation risks using additive projection and multiplicative projection models, as proposed by ICRP. Total death probability rate (1985) and probability rate of cancer death (1983 to 1987) were used as data base. The following indicators were calculated: total conditional death probability rate and conditional death probability rate; normalized death age probability density and unconditional death probability rate; attributable life-time probability of cancer death; and other risk indicators, including mean loss of life expectancy, reduction of life expectancy, mean annually committed probability of attributable cancer deaths, annual extra probability of cancer death, probability density of the age of death, maximum relative death probability rate (age at maximum relative rate), and probabilistic aging. In terms of calculations of these risk indicators for the comprehensive cancer death, there was no great difference between the Japanese population and ICRP. When calculating according to sites of cancer, calculations of indicators for cancer mortality (or cancer cure rate) in the Japanese population might bedifferent from ICRP's calculation. (N.K.) different from ICRP's calculations. (N.K.)

  19. Scientific view of low-level radiation risks

    International Nuclear Information System (INIS)

    Hall, E.J.

    1991-01-01

    The average number of diagnostic x-ray procedures per year in the United States equals the total population and results in an annual collective effective dose equivalent of about 9 million person-rem. Possible deleterious effects include (a) genetic consequences, the risks of which can be assessed only from animal studies; (b) carcinogenesis, which can be assessed from survivors of nuclear bombings and patients exposed for medical reasons; and (c) effects on the developing embryo or fetus. For stochastic endpoints such as cancer and genetic anomalies, it is estimated that the current practice of radiology in the United States increases spontaneous frequency by less than 1%. No single procedure is likely to produce harm to the conceptus, but an accumulation of procedures in a pregnant woman could be hazardous during the sensitive period of 8-15 weeks after conception, with microcephaly and mental retardation the most likely deleterious effects. The balance of risk versus benefit in diagnostic radiology is heavily weighted toward benefit, but the risks are there, and constant efforts are needed to reduce radiation doses to the minimum necessary

  20. Low-dose extrapolation of radiation health risks: some implications of uncertainty for radiation protection at low doses.

    Science.gov (United States)

    Land, Charles E

    2009-11-01

    Ionizing radiation is a known and well-quantified human cancer risk factor, based on a remarkably consistent body of information from epidemiological studies of exposed populations. Typical examples of risk estimation include use of Japanese atomic bomb survivor data to estimate future risk from radiation-related cancer among American patients receiving multiple computed tomography scans, persons affected by radioactive fallout, or persons whose livelihoods involve some radiation exposure, such as x-ray technicians, interventional radiologists, or shipyard workers. Our estimates of radiation-related risk are uncertain, reflecting statistical variation and our imperfect understanding of crucial assumptions that must be made if we are to apply existing epidemiological data to particular situations. Fortunately, that uncertainty is also highly quantifiable, and can be presented concisely and transparently. Radiation protection is ultimately a political process that involves consent by stakeholders, a diverse group that includes people who might be expected to be risk-averse and concerned with plausible upper limits on risk (how bad could it be?), cost-averse and concerned with lower limits on risk (can you prove there is a nontrivial risk at current dose levels?), or combining both points of view. How radiation-related risk is viewed by individuals and population subgroups also depends very much on perception of related benefit, which might be (for example) medical, economic, altruistic, or nonexistent. The following presentation follows the lead of National Council on Radiation Protection and Measurements (NCRP) Commentary 14, NCRP Report 126, and later documents in treating radiation protection from the viewpoint of quantitative uncertainty analysis.

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  2. Radiation exposure and risk of pediatric thyroid cancer

    International Nuclear Information System (INIS)

    Miyakawa, Megumi

    2012-01-01

    A large amount of radioactive substances were released in air following the Great East Japan Earthquake, tsunami and Fukushima Nuclear Power Plant Accident (Mar. 2011), of which subsequent medical and pediatric events are reported herein. Many residents who had lived close to the Plant had to dwell in the evacuation area. The risk of their pediatric thyroid cancer has become a subject of anxiety since the incidence of the cancer alone is known to have increased post Chernobyl nuclear accident. The cancer is quite rare in the pediatric field, the tissue type is mostly of differentiated papillocarcinoma, and the long prognosis is reportedly as good as that of the cancer not due to radiation exposure if surgically treated appropriately. After the Accident, Radiation Medical Science Center for Fukushima Health Management Survey was founded in Fukushima Medical University, where the whole lifetime health management of Fukushima prefectural residents is to be continued. Among them, the ultrasonic examination of the thyroid started in Oct. 2011 to 360 thousands children of the age 20 mm cyst or >5 mm solid node. It is important to carefully watch the health of children involving their mental side as they suffer from the experience of ''exposed'', rather than the actual physical effect. (T.T.)

  3. Health risks (early, delayed and genetic) from the present radiation level

    International Nuclear Information System (INIS)

    Stranden, E.

    1981-01-01

    A general survey is given of the risks of early, delayed and genetic injuries from present radiation environment. Brief data is presented on some industrial and medical accidents. It is stated that in Norway there are 5-10 incidents per year in industrial radiography, none of which have led to radiation syndrome. Delayed radiation effects are discussed and figures quoted for risk due to mining, industrial and medical radiography and natural sources. Genetic effects are similarly discussed and genetically significant doses from similar sources are quoted. It is concluded that the health risk from the radiation environment is very small compared with other risks. (JIW)

  4. Risk concepts in various fields including radiation protection. A historical review and some recent topics

    International Nuclear Information System (INIS)

    Kai, Michiaki

    2000-01-01

    This is a review by the expert group concerning risks in radiation protection and in chemical management, recent state of protection and of health-risk assessment of low dose radiation, and risk concepts in other fields. Risk concepts in radiation protection are described mainly on ICRP: Its history leading to its Publication 1 (1958), Pub. 9 (1965), Pub. 26 (1977) and Pub. 60 (1990). In that recent publication, the term, risk, is used only for the established one like estimated risk or excess relative risk. Risk management of chemicals involves that against pollution from environmental and ecological aspects, and assessment of dioxin and chemicals from toxicology and carcinogenicity aspects. Recently, risks of low dose radiation have been actively discussed conceivably because of possible reduction of the exposure limit in ICRP Recommendation 1990, Chernobyl accident, advances of radiation biology and radiation protection problem in the radioactive waste disposition. Globally, many academic societies such as American Health-Physics Society published Position Statements and Reports and there are activities like the Research program plan for the risk and an international conference of bridging radiation policy and science. Risk concepts involve technological and ecological ones, insurance ones and health ones. Risk assessment or analysis is done through recognition, measurement and prediction, thus through the scientific process based on objective facts. (K.H.)

  5. How to promote risk literacy of atomic energy and radiation in public

    International Nuclear Information System (INIS)

    Matsubara, Junko

    2005-01-01

    According to broad use of radiation and nuclear energy in our society we recognize that the promotion of risk literacy in public is urgently needed. Necessary topics as follows are explained and discussed. 1. view-points of micro-, macro- and human-world, 2.how to measure risks objectively, 3. why we need to consider nuclear/radiation risks, 4. nuclear/radiation safety measures, 5. how to protect ourselves from risks, and 6. needs to establish new system of comprehensive risk education in the future. (author)

  6. Radiation risk statement in the participant information for a research protocol that involves exposure to ionising radiation

    International Nuclear Information System (INIS)

    Caon, Martin

    2005-01-01

    A Human Research Ethics Committee (HREC) is required to scrutinise the protocols of clinical drug trials that recruit patients as participants. If the study involves exposing the participants to ionizing radiation the information provided to the participant should contain a radiation risk statement that is understandable by the Committee and the participant. The information that should be included in the risk statement is available from a variety of published sources and is discussed. The ARPANSA Code of Practice Exposure of Humans to Ionizing Radiation for Research Purposes (2005) states explicitly what the responsibilities of the researcher and the HREC are. Some research protocols do not provide the information required by good radiation protection practice and explicitly called for by the Code. Nine points (including: state that ionizing radiation is involved; that the radiation is additional to standard care; the effective dose to be received; the dose compared to natural background; the dose to the most exposed organs; a statement of risk; the benefits accruing from the exposure; ask the participant about previous exposures; name a contact person from whom information may be sought) that should be considered for inclusion in the participant information are presented and discussed. An example of a radiation risk statement is provided

  7. Methodology in use for the assessment of carcinogenic risk. II. Radiation. Oncology overview

    International Nuclear Information System (INIS)

    1983-04-01

    Oncology Overviews are a service of the International Cancer Research Data Bank (ICRDB) Program of the National Cancer Institute, intended to facilitate and promote the exchange of information between cancer scientists by keeping them aware of literature related to their research being published by other laboratories throughout the world. Each Oncology Overview represents a survey of the literature associated with a selected area of cancer research. It contains abstracts of articles which have been selected and organized by researchers associated with the field. Contents: Assessment of carcinogenic risk from environmental and occupational exposures to ionizing radiation; Assessment of carcinogenic risk from exposure to ionizing radiation used for medical diagnosis or treatment; Assessment of carcinogenic risk from exposure to ionizing radiation following nuclear bomb explosions; Comparison of risk from radiation sources with risk from nonradiation sources; Experimental studies to assess risk of carcinogenesis following exposure to ionizing radiation; Theoretical aspects of dose-response relationships in the assessment of carcinogenic risk from exposure to ionizing radiation; Public policy and standards for acceptable risk from exposure to ionizing radiation; General reviews on the assessment of risk from exposure to ionizing radiation

  8. Lifetime attributable risk for cancer from occupational radiation exposure among radiologic technologists

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Eun Kyeong; Lee, Won Jin [Dept. of Preventive Medicine, Korea University College of Medicine, Seoul (Korea, Republic of)

    2016-12-15

    Medical radiation workers were among the earliest occupational groups exposed to external ionizing radiation due to their administration of a range of medical diagnostic procedures. Ionizing radiation is a confirmed human carcinogen for most organ sites. This study, therefore, was aimed to estimate lifetime cancer risk from occupational exposure among radiologic technologists that has been recruited in 2012-2013. Our findings showed a small increased cancer risk in radiologic technologists from their occupational radiation exposure in Korea. However, continuous dose monitoring and strict regulation on occupational safety at the government level should be emphasized to prevent any additional health hazards from occupational radiation exposure. Our findings showed a small increased cancer risk in radiologic technologists from their occupational radiation exposure in Korea. However, continuous dose monitoring and strict regulation on occupational safety at the government level should be emphasized to prevent any additional health hazards from occupational radiation exposure.

  9. Lifetime attributable risk for cancer from occupational radiation exposure among radiologic technologists

    International Nuclear Information System (INIS)

    Moon, Eun Kyeong; Lee, Won Jin

    2016-01-01

    Medical radiation workers were among the earliest occupational groups exposed to external ionizing radiation due to their administration of a range of medical diagnostic procedures. Ionizing radiation is a confirmed human carcinogen for most organ sites. This study, therefore, was aimed to estimate lifetime cancer risk from occupational exposure among radiologic technologists that has been recruited in 2012-2013. Our findings showed a small increased cancer risk in radiologic technologists from their occupational radiation exposure in Korea. However, continuous dose monitoring and strict regulation on occupational safety at the government level should be emphasized to prevent any additional health hazards from occupational radiation exposure. Our findings showed a small increased cancer risk in radiologic technologists from their occupational radiation exposure in Korea. However, continuous dose monitoring and strict regulation on occupational safety at the government level should be emphasized to prevent any additional health hazards from occupational radiation exposure.

  10. Physics must join with biology in better assessing risk from low-dose irradiation

    International Nuclear Information System (INIS)

    Feinendegen, L. E.; Neumann, R. D.

    2005-01-01

    This review summarises the complex response of mammalian cells and tissues to low doses of ionising radiation. This thesis encompasses induction of DNA damage, and adaptive protection against both renewed damage and against propagation of damage from the basic level of biological organisation to the clinical expression of detriment. The induction of DNA damage at low radiation doses apparently is proportional to absorbed dose at the physical/chemical level. However, any propagation of such damage to higher levels of biological organisation inherently follows a sigmoid function. Moreover, low-dose-induced inhibition of damage propagation is not linear, but instead follows a dose-effect function typical for adaptive protection, after an initial rapid rise it disappears at doses higher than ∼0.1-0.2 Gy to cells. The particular biological response duality at low radiation doses precludes the validity of the linear-no-threshold hypothesis in the attempt to relate absorbed dose to cancer. In fact, theory and observation support not only a lower cancer incidence than expected from the linear-no-threshold hypothesis, but also a reduction of spontaneously occurring cancer, a hormetic response, in the healthy individual. (authors)

  11. Understanding and characterisation of the risks to human health from exposure to low levels of radiation

    International Nuclear Information System (INIS)

    Goodhead, D. T.

    2009-01-01

    Exposure to ionising radiation can lead to a wide variety of health effects. Cancer is judged to be the main risk from radiation at low doses and low dose rates, and controlling this risk has been the main factor in developing radiation protection practice. Conventional paradigms of radiobiology and radiation carcinogenesis have served to guide extrapolations of epidemiological data on exposed human populations, so as to estimate risks at low doses and low dose rates, to other types of ionising radiation and to non-uniform exposures. These paradigms are founded on a century of experimental and theoretical studies, but nevertheless there remain many uncertainties. Major assumptions and simplifications have been introduced to achieve a practical system of additive doses (and implied risks) for radiation protection. Advancing epidemiological studies and experimental research continue to reduce uncertainties in some areas while, in others, they raise new challenges to the generality and applicability of the conventional paradigms. (authors)

  12. Interactive effects between radiation and other factors on cancer risk among A-bomb survivors

    International Nuclear Information System (INIS)

    Akiba, Suminori

    1991-01-01

    This paper reviews RERF cancer studies conducted to examine interactive effects between radiation and epidemiological risk factors, including smoking habits, occupation, dietary habits and OB/GYN history. Special emphasis is placed on a review of studies of interactive effects between cigarette smoking and radiation on lung cancer risk. Comments on these studies are made and proposals for future studies are presented. (author)

  13. Risk associated with occupational exposure to ionizing radiation kept in perspective

    International Nuclear Information System (INIS)

    Bonnell, J.A.; Harte, G.

    1978-01-01

    The risks associated with exposure to ionizing radiations are placed in perspective by a study of the natural incidence of those diseases in the United Kingdom that can be induced by radiation exposure. It is apparent that at ICRP recommended annual dose equivalent limits the small risks associated with exposure to ionizing radiations are acceptable, bearing in mind the obvious benefits that accrue from activities such as power production. This applies both to genetic and somatic diseases. (author)

  14. The risk of melanoma associated with ambient summer ultraviolet radiation.

    Science.gov (United States)

    Pinault, Lauren; Bushnik, Tracey; Fioletov, Vitali; Peters, Cheryl E; King, Will D; Tjepkema, Michael

    2017-05-17

    Depletion of the ozone layer has meant that ambient ultraviolet radiation (UVR) has increased in recent decades. At the same time, the incidence of skin cancers, including melanoma, has risen. The relatively few large-scale studies that linked ambient UVR to melanoma found a trend toward rising incidence closer to the equator, where UVR estimates are highest. Similar research has not been conducted in Canada, where ambient UVR is generally lower than in countries further south. Modelled UVR data for the months of June through August during the 1980-to-1990 period were spatially linked in Geographic Information Systems to 2.4 million white members of the 1991 Canadian Census Health and Environment Cohort and tracked for melanoma diagnosis over an 18-year period (1992 to 2009). Standard Cox proportional hazards models were used to estimate melanoma risk associated with increases of ambient summer UVR, assigned by residence at baseline. Models were adjusted for age, sex and socioeconomic (SES) characteristics. Separate analyses by body site of melanoma were conducted. Effect modification of the association between ambient UVR and melanoma by sex, age, outdoor occupation and selected SES characteristics was evaluated. Differences of one standard deviation (446 J/m², or 7% of the mean) in average ambient summer UVR were associated with an increased hazard ratio (HR) for melanoma of 1.22 (95% CI: 1.19 to 1.25) when adjusting for sex, age and SES characteristics. The HR for melanoma in relative UVR (per 1 standard deviation) was larger for men (HR = 1.26; 95% CI: 1.21 to 1.30) than for women (HR = 1.17; 95% CI: 1.13 to 1.22). Ambient summer UVR is associated with a greater risk of melanoma among the white population, even in a country where most people live within a narrow latitudinal belt. A stronger association between melanoma and ambient UVR was evident among men and among people of lower SES.

  15. Studies on risk estimation to public from medical radiation (III)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hai Yong; Kim, Jong Hyung; Kim, Hyeog Ju; Kim, Ji Soon; Oh, Hyeon Joo; Kim, Cheol Hyeon; Yang, Hyun Kyu [Korea Food and Drug Administraion, Seoul (Korea, Republic of); Park, Chan Il [Seoul National Univ., Seoul (Korea, Republic of)

    1998-06-01

    A nationwide survey was conducted to give representative levels of effective doses to patient for 17 types of CT examination and also representative level of MGD (mean glandular dose) to standard breast for mammography X-ray equipment. The effective doses to patient from 16 CT scanners were estimated from measurement of CTDI (Computed Tomography Dose Index) in air by multiplying conversion coefficients which are specified by National Radiological Protection Board in United Kingdom. The lowest and hightest mean values of effective dose measured to patient from CT scanner were 0.05 mSv for IAM examination and 17.75 mSv for routine abdomen examination, respectively. The average values of 17 effective doses were lower than other results of foreign countrys' surveys. The mean glandular doses to a standard breast for 26 mammography units were estimated from measurement of the air kerma at the surface of a 40 mm plain Perspex phantom by applying conversion factors described in Report 59 of the Institute of Physical Sciences in Medicine of United Kingdom. The exposure factors for this measurement were those used clinically at each hospital. The average MGD to standard breast was 1.06 mGy in units with grid and 0.49 mGy in units without grid. These results are lower than guidance levels by IPSM and AAPM. These results will be used for risk estimation to the Korean public from the medical radiation.

  16. Risk of ionising radiation to trainee orthopaedic surgeons.

    Science.gov (United States)

    Khan, Ishrat A; Kamalasekaran, Senthil; Fazal, M Ali

    2012-02-01

    We undertook this study to determine the amount of scattered radiation received by the primary surgeon, assistant and patient during dynamic hip screw fixation for proximal femoral fractures. Data was collected from fifty patients. Five registrars were included as operating surgeon and four senior house officers as assistant surgeon. Radiation was monitored by thermo luminescent dosimeters placed on the surgeon and assistant. The approximate distance of surgeon and assistant from the operative site was measured. A dosimeter on the unaffected hip of patients measured the radiation to the patient. The results show that the surgeon's dominant hand receives the highest dose of radiation and radiation exposure is dependent on the experience of the operator. Our study concludes that exposure to radiation during this procedure is well below the toxic levels; however greater awareness is needed for harmful effects of exposure to long term low dose radiation.

  17. What is risk perception in general and in radiation protection?

    International Nuclear Information System (INIS)

    Chen, David Te-Yao

    2000-01-01

    In view of the universal roll Risk Perception plays in our daily life, the author makes an effort to understand this notion better. For such a subtle task, it will be good to know something about the person, who undertakes such a challenge. Thus, he first makes a short description of himself in a number of relevant personal feature, emphasising rather what he is not: cadre of insurance company.... etc. He starts with a literal understanding of the idiom Risk Perception in English and in other languages (in Chinese). This formulation, still abstract, is framed with concrete objects, and materialised into touchable structures. He then puts life into these structures, and makes them accessible to emotion and experience. Now that this notion is animated, he follows it's way into life in the field of Radiation Protection, and find among others that the term Cost and Benefit correspond to the Chinese idiom, and that the system of Justification and Optimisation is as difficult to achieve objectively as an Upright Walk on the Confucian Path to-ward the Middle. One of the difficulties lies in the difference in the scale in estimating values. For instance, though the idea of Asian and Western Values are rather diffuse, their difference is never-the-less high enough to render it to be insurmountable, at least at present. These observation belong actually to common experience of Health physicists, and nothing new or spectacular is presented. The author emphasises only, again not a new idea of his own, only putting weight to, that perception depends on point of view, or rather on stand of viewing points, and rarely represent the whole story, the true situation. This leads, according to the author, to the well known and accepted term of Risk Residuum, in German, Rest Risiko. Despite of partialness of all perceptions, solid decisions are based on perception. We all know mournful consequences of unsound decision in our daily life. It is tragic, when this happens in history. The

  18. What is risk perception in general and in radiation protection?

    Energy Technology Data Exchange (ETDEWEB)

    Chen, David Te-Yao [CH-5400 Baden (Switzerland)

    2000-05-01

    In view of the universal role Risk Perception plays in our daily life, the author makes an effort to understand this notion better. For such a subtle task, it will be good to know something about the person who undertakes such a challenge. Thus, he first makes a short description of himself in a number of relevant personal feature, emphasising rather what he is not: cadre of insurance company.... etc. He starts with a literal understanding of the idiom Risk Perception in English and in other languages (in Chinese). This formulation, still abstract, is framed with concrete objects, and materialised into touchable structures. He then puts life into these structures, and makes them accessible to emotion and experience. Now that this notion is animated, he follows its way into life in the field of Radiation Protection, and find among others that the term Cost and Benefit correspond to the Chinese idiom, and that the system of Justification and Optimisation is as difficult to achieve objectively as an Upright Walk on the Confucian Path to-ward the Middle. One of the difficulties lies in the difference in the scale in estimating values. For instance, though the idea of Asian and Western Values are rather diffuse, their difference is never-the-less high enough to render it to be insurmountable, at least at present. These observation belong actually to common experience of Health physicists, and nothing new or spectacular is presented. The author emphasises only, again not a new idea of his own, only putting weight to, that perception depends on point of view, or rather on stand of viewing points, and rarely represent the whole story, the true situation. This leads, according to the author, to the well known and accepted term of Risk Residuum, in German, Rest Risiko. Despite of partialness of all perceptions, solid decisions are based on perception. We all know mournful consequences of unsound decision in our daily life. It is tragic, when this happens in history. The

  19. 2013 Space Radiation Standing Review Panel Status Review for: The Risk of Acute and Late Central Nervous System Effects from Radiation Exposure, The Risk of Acute Radiation Syndromes Due to Solar Particle Events (SPEs), The Risk Of Degenerative Tissue Or Other Health Effects From Radiation Exposure, and The Risk of Radiation Carcinogenesis

    Science.gov (United States)

    2014-01-01

    The Space Radiation Standing Review Panel (from here on referred to as the SRP) was impressed with the strong research program presented by the scientists and staff associated with NASA's Space Radiation Program Element and National Space Biomedical Research Institute (NSBRI). The presentations given on-site and the reports of ongoing research that were provided in advance indicated the potential Risk of Acute and Late Central Nervous System Effects from Radiation Exposure (CNS) and were extensively discussed by the SRP. This new data leads the SRP to recommend that a higher priority should be placed on research designed to identify and understand these risks at the mechanistic level. To support this effort the SRP feels that a shift of emphasis from Acute Radiation Syndromes (ARS) and carcinogenesis to CNS-related endpoints is justified at this point. However, these research efforts need to focus on mechanisms, should follow pace with advances in the field of CNS in general and should consider the specific comments and suggestions made by the SRP as outlined below. The SRP further recommends that the Space Radiation Program Element continue with its efforts to fill the vacant positions (Element Scientist, CNS Risk Discipline Lead) as soon as possible. The SRP also strongly recommends that NASA should continue the NASA Space Radiation Summer School. In addition to these broad recommendations, there are specific comments/recommendations noted for each risk, described in detail below.

  20. Risk of second bone sarcoma following childhood cancer: role of radiation therapy treatment

    OpenAIRE

    Schwartz, Boris; Benadjaoud, Mohamed Amine; Clero, Enora; Haddy, Nadia; El-Fayech, Chiraz; Guibout, Catherine; Teinturier, Cecile; Oberlin, Odile; Veres, Cristina; Pacquement, Helene; Munzer, Martine; Tan Dat N'Guyen; Bondiau, Pierre-Yves; Berchery, Delphine; Laprie, Anne

    2014-01-01

    International audience; : Bone sarcoma as a second malignancy is rare but highly fatal. The present knowledge about radiation-absorbed organ dose-response is insufficient to predict the risks induced by radiation therapy techniques. The objective of the present study was to assess the treatment-induced risk for bone sarcoma following a childhood cancer and particularly the related risk of radiotherapy. Therefore, a retrospective cohort of 4,171 survivors of a solid childhood cancer treated be...

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

    International Nuclear Information System (INIS)

    Deniz, Dalji

    2006-01-01

    . This 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

  2. Current issues regarding radiation risk education in Medical Universities of Japan

    International Nuclear Information System (INIS)

    Tsuzuki, Teruhisa; Hosoi, Yoshio; Matsuda, Naoki; Kanda, Reiko; Hosoya, Noriko; Miyagawa, Kiyoshi; Awai, Kazuo; Kondo, Takashi

    2017-01-01

    The main purpose of radiation research is to understand the biological effects of radiation exposure to humans, the molecular mechanisms of biological response m organisms, and its sale application for medical and industrial use. In order to know the current state or education on fundamentals of radiology including radiation biology, a nation-wide questionnaire survey had been performed at medical schools and different co-medical courses in Japanese universities, during the period of 2004 and 2005. The survey results showed: (1) Difference in teaching hours for education on radiation between medical schools with and without department or division of radiation biology or radiation-related field. (2) Teaching hours for education on radiation in nursing course were very limited among the co-medical courses. Although, some improvement have been found about the state of education on radiation risk at medical schools, after the disaster of nuclear accident at Fukushima No.1 Nuclear Power Plant of TEPCO in March 2011. However, still much more effort t is needed to improve basic education on radiation. Science Council of Japan issued the recommendation on September 4, 2014 'Making radiation health risk education compulsory in medical education'. The working group for this purpose was set up under the Council of Head of National Medical Schools of Japan, on January 28, 2015. Here, we describe the details and current issues regarding radiation risk education in medical schools of Japan, as well as the efforts required for its betterment. (author)

  3. Estimates of radiation doses and cancer risk from food intake in Korea

    International Nuclear Information System (INIS)

    Moon, Eun Kyeong; Lee, Won Jin; Ha, Wi Ho; Seo, Song Won; Jin, Young Woo; Jeong, Kyu Hwan; Yoon, Hae Jung; Kim, Hyoung Soo; Hwang, Myung Sil; Choi, Hoon

    2016-01-01

    After the Fukushima Daiichi nuclear power plant accident, a widespread public concern for radiation exposure through the contamination of domestic or imported food has continued worldwide. Because the internal exposure from contaminated food is an important consideration for human health effect, some studies for estimating radiation doses and cancer risk from the Fukushima nuclear accident have been conducted in several countries (1). The aims of the study is to estimate internal radiation dose and lifetime risks of cancer from food ingestion in Korean population. Our findings suggest no discernible increase n radiation doses or excess fatal cancer risk from food ingestion at this stage in Korea, and provide scientific evidence of the risk communication with general public associated with low-dose radiation exposure.

  4. The radiologist's professional radiation risk in the view of international epidemiological studies

    International Nuclear Information System (INIS)

    Schuettmann, W.

    1980-01-01

    Publications of the past 30 years on the problem of professional radiation risk of the radiologist were analysed. Because of the low extent of possible damaging effects to be expected only those results of epidemiological papers were considered for the quantification of this risk which were based on large collectives. The radiation-induced malignant neoplasms as the decisive risk are in the focus of consideration. The decrease in radiation-induced professional leukemias and carcinomas, which is statistically clearly demonstrated, is described. The remaining, though only minimal, risk on the conditions of present radiation protection, which can be concluded from theoretical considerations and epidemiological knowledge, is discussed in detail. Finally, the importance of certain partial exposures of the body with respect to non-stochastic radiation effects on eyes and skin is referred to. (author)

  5. Estimates of radiation doses and cancer risk from food intake in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Eun Kyeong; Lee, Won Jin [Korea University, Seoul (Korea, Republic of); Ha, Wi Ho; Seo, Song Won; Jin, Young Woo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Jeong, Kyu Hwan [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Yoon, Hae Jung; Kim, Hyoung Soo; Hwang, Myung Sil [Ministry of Food and Drug Safety, Cheongju (Korea, Republic of); Choi, Hoon [Wonkwang University, Iksan (Korea, Republic of)

    2016-04-15

    After the Fukushima Daiichi nuclear power plant accident, a widespread public concern for radiation exposure through the contamination of domestic or imported food has continued worldwide. Because the internal exposure from contaminated food is an important consideration for human health effect, some studies for estimating radiation doses and cancer risk from the Fukushima nuclear accident have been conducted in several countries (1). The aims of the study is to estimate internal radiation dose and lifetime risks of cancer from food ingestion in Korean population. Our findings suggest no discernible increase n radiation doses or excess fatal cancer risk from food ingestion at this stage in Korea, and provide scientific evidence of the risk communication with general public associated with low-dose radiation exposure.

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

    Science.gov (United States)

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

    2018-02-01

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

  7. Senior medical students' awareness of radiation risks from common diagnostic imaging examinations.

    Science.gov (United States)

    Scali, Elena; Mayo, John; Nicolaou, Savvas; Kozoriz, Michael; Chang, Silvia

    2017-12-01

    Senior medical students represent future physicians who commonly refer patients for diagnostic imaging studies that may involve ionizing radiation. The radiology curriculum at the University of British Columbia provides students with broad-based knowledge about common imaging examinations. The purpose of this study was to investigate students' awareness of radiation exposures and risks. An anonymous multiple-choice cross-sectional questionnaire was distributed to final year medical students to assess knowledge of radiation from common diagnostic examinations and radiation-related risks following completion of the longitudinal radiology curriculum, carried out over the four years of medical training. Sixty-three of 192 eligible students participated (33% response rate). The majority felt that knowledge of radiation doses of common imaging examinations is somewhat or very important; however, only 12% (N = 8) routinely discuss radiation-related risks with patients. While all respondents recognized children as most sensitive to the effects of radiation, only 24% (N = 15) correctly identified gonads as the most radiation-sensitive tissue. Almost all respondents recognized ultrasound and MRI as radiation free modalities. Respondents who correctly identified the relative dose of common imaging examinations in chest x-ray equivalents varied from 3-77% (N = 2 - 49); the remaining responses were largely underestimates. Finally, 44% (N = 28) correctly identified the excess risk of a fatal cancer from an abdominal CT in an adult, while the remainder underestimated this risk. Medical students acknowledge the importance of radiation-related issues to patient care. While almost all students are familiar with radiation-free modalities, many are not familiar with, and commonly underestimate, the relative doses and risks of common imaging studies. This may expose patients to increasing imaging investigations and exposure to radiation hazards.

  8. Space Radiation Heart Disease Risk Estimates for Lunar and Mars Missions

    Science.gov (United States)

    Cucinotta, Francis A.; Chappell, Lori; Kim, Myung-Hee

    2010-01-01

    The NASA Space Radiation Program performs research on the risks of late effects from space radiation for cancer, neurological disorders, cataracts, and heart disease. For mortality risks, an aggregate over all risks should be considered as well as projection of the life loss per radiation induced death. We report on a triple detriment life-table approach to combine cancer and heart disease risks. Epidemiology results show extensive heterogeneity between populations for distinct components of the overall heart disease risks including hypertension, ischaemic heart disease, stroke, and cerebrovascular diseases. We report on an update to our previous heart disease estimates for Heart disease (ICD9 390-429) and Stroke (ICD9 430-438), and other sub-groups using recent meta-analysis results for various exposed radiation cohorts to low LET radiation. Results for multiplicative and additive risk transfer models are considered using baseline rates for US males and female. Uncertainty analysis indicated heart mortality risks as low as zero, assuming a threshold dose for deterministic effects, and projections approaching one-third of the overall cancer risk. Medan life-loss per death estimates were significantly less than that of solid cancer and leukemias. Critical research questions to improve risks estimates for heart disease are distinctions in mechanisms at high doses (>2 Gy) and low to moderate doses (<2 Gy), and data and basic understanding of radiation doserate and quality effects, and individual sensitivity.

  9. Assessment of radiation risk as a part of ecological risk in the Republic of Belarus after the Chernobyl accident

    International Nuclear Information System (INIS)

    Saltanova, Irina; Saltanov, Eugene

    2008-01-01

    Full text: The purpose of the work: foundation for principles of planning protection measures, that provide safety for population activity on the territories, contaminated with radio-nuclides, by analysing radio-chemical situation, using risk assessment methods. Problems set in the work: -) Analyses of radiation risk in the structure of ecological risk in the territory of the Republic of Belarus after the Chernobyl accident; -) Investigation of chemical risk level, connected with air pollution from stationary objects exhausts, for the territories, contaminated with Chernobyl radio-nuclides; -) Modelling of the combined impact of ionising radiation and chemical carcinogen for the possible ecological risk assessment; -) Involving modern geo informational systems in the radio-ecological risk assessment process; -) Foundation for the assessment methodology of the complex influence of negative factors in the territories, contaminated with Chernobyl radio-nuclides. The problems are solved by carrying out specific experiments and by analysing published and own data on radioactive and chemical contamination of some regions of Belarus. Major findings: Radiation input to the really registered carcinogens is estimated to app. 10 %. In case of multiple factors influence of different contaminators of industrial and natural origin (i.e. radiation is not the only negative factor), ignorance of non-radiation origin factors may seriously distort estimation of radiation risk, when it is related to the registered effects. Radiation should be in no way treated as the major factor of real ecological risk in Belarus. Method for comparative analysis of territories' ecological risk level is developed and implemented. A GIS segment, that includes subsystem of the real and forecasted radio-ecological mapping, is created. The authors grounded the experimental model for study the complex influence of radioactive and non-radioactive (chemical carcinogen) factors. Revealed dependencies 'dose

  10. Review of NASA approach to space radiation risk assessments for Mars exploration.

    Science.gov (United States)

    Cucinotta, Francis A

    2015-02-01

    Long duration space missions present unique radiation protection challenges due to the complexity of the space radiation environment, which includes high charge and energy particles and other highly ionizing radiation such as neutrons. Based on a recommendation by the National Council on Radiation Protection and Measurements, a 3% lifetime risk of exposure-induced death for cancer has been used as a basis for risk limitation by the National Aeronautics and Space Administration (NASA) for low-Earth orbit missions. NASA has developed a risk-based approach to radiation exposure limits that accounts for individual factors (age, gender, and smoking history) and assesses the uncertainties in risk estimates. New radiation quality factors with associated probability distribution functions to represent the quality factor's uncertainty have been developed based on track structure models and recent radiobiology data for high charge and energy particles. The current radiation dose limits are reviewed for spaceflight and the various qualitative and quantitative uncertainties that impact the risk of exposure-induced death estimates using the NASA Space Cancer Risk (NSCR) model. NSCR estimates of the number of "safe days" in deep space to be within exposure limits and risk estimates for a Mars exploration mission are described.

  11. Managing of risks in the cases of radiation and materials: On the way to harmonization?

    International Nuclear Information System (INIS)

    Janssen, M.P.M.; Slaper, H.; Lembrechts, J.F.M.M.; Moen, J.E.T.

    1995-01-01

    Risk analysis is important to assess environmental loads of human activities. Besides, risk analysis can be used in formulating environmental standards, the adjustment of political decisions and prioritization in the environmental policy. A pre-condition for such a use of risk analysis is that the starting points and the risk analysis methods are mutually consistent and adjusted. In this article attention is paid to the mutual adjustment and comparison of risk analysis of radiation and materials. 14 refs

  12. Health effects of low-level ionising radiation: biological basis for risk assessment

    International Nuclear Information System (INIS)

    Upton, A.C.

    1987-01-01

    The biological basis for risk assessment is discussed. The risks of carcinogenic effects, teratogenic effects, and genetic (heritable) effects are estimated to vary in proportion with the dose of radiation in the low-dose domain; however, the risks also appear to vary with the LET of the radiation, age at the time of irradiation, and other variables. Although the data suffice to place the risks in perspective with other hazards of modern life, further research to refine the reliability of the risk assessment is called for. (author)

  13. Medical radiation workers and the risk of cancer: A retrospective follow-up study

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Seul Ki; Cha, Eun Shil; Lee, Won Jin [Dept. of Preventive Medicine, Korea University College of Medicine, Seoul (Korea, Republic of)

    2017-04-15

    Medical radiation workers are important population to study of chronic low dose radiation exposure and the numbers are continuously increasing worldwide. We have launched a retrospective cohort for medical radiation workers to investigate their health status and to assess the association with occupational radiation exposure. In this first analysis of cancer incidence using data from national dose registry, a number of significant findings at specific cancer sites were observed. Further investigation is needed to assess the association with observed cancer risk and occupational radiation exposure. In this first analysis of cancer incidence using data from national dose registry, a number of significant findings at specific cancer sites were observed.

  14. NASA Space Radiation Protection Strategies: Risk Assessment and Permissible Exposure Limits

    Science.gov (United States)

    Huff, J. L.; Patel, Z. S.; Simonsen, L. C.

    2017-01-01

    Permissible exposure limits (PELs) for short-term and career astronaut exposures to space radiation have been set and approved by NASA with the goal of protecting astronauts against health risks associated with ionizing radiation exposure. Short term PELs are intended to prevent clinically significant deterministic health effects, including performance decrements, which could threaten astronaut health and jeopardize mission success. Career PELs are implemented to control late occurring health effects, including a 3% risk of exposure induced death (REID) from cancer, and dose limits are used to prevent cardiovascular and central nervous system diseases. For radiation protection, meeting the cancer PEL is currently the design driver for galactic cosmic ray and solar particle event shielding, mission duration, and crew certification (e.g., 1-year ISS missions). The risk of cancer development is the largest known long-term health consequence following radiation exposure, and current estimates for long-term health risks due to cardiovascular diseases are approximately 30% to 40% of the cancer risk for exposures above an estimated threshold (Deep Space one-year and Mars missions). Large uncertainties currently exist in estimating the health risks of space radiation exposure. Improved understanding through radiobiology and physics research allows increased accuracy in risk estimation and is essential for ensuring astronaut health as well as for controlling mission costs, optimization of mission operations, vehicle design, and countermeasure assessment. We will review the Space Radiation Program Element's research strategies to increase accuracy in risk models and to inform development and validation of the permissible exposure limits.

  15. An Overview of NASA's Risk of Cardiovascular Disease from Radiation Exposure

    Science.gov (United States)

    Patel, Zarana S.; Huff, Janice L.; Simonsen, Lisa C.

    2015-01-01

    The association between high doses of radiation exposure and cardiovascular damage is well established. Patients that have undergone radiotherapy for primary cancers of the head and neck and mediastinal regions have shown increased risk of heart and vascular damage and long-term development of radiation-induced heart disease [1]. In addition, recent meta-analyses of epidemiological data from atomic bomb survivors and nuclear industry workers has also shown that acute and chronic radiation exposures is strongly correlated with an increased risk of circulatory disease at doses above 0.5 Sv [2]. However, these analyses are confounded for lower doses by lifestyle factors, such as drinking, smoking, and obesity. The types of radiation found in the space environment are significantly more damaging than those found on Earth and include galactic cosmic radiation (GCR), solar particle events (SPEs), and trapped protons and electrons. In addition to the low-LET data, only a few studies have examined the effects of heavy ion radiation on atherosclerosis, and at lower, space-relevant doses, the association between exposure and cardiovascular pathology is more varied and unclear. Understanding the qualitative differences in biological responses produced by GCR compared to Earth-based radiation is a major focus of space radiation research and is imperative for accurate risk assessment for long duration space missions. Other knowledge gaps for the risk of radiation-induced cardiovascular disease include the existence of a dose threshold, low dose rate effects, and potential synergies with other spaceflight stressors. The Space Radiation Program Element within NASA's Human Research Program (HRP) is managing the research and risk mitigation strategies for these knowledge gaps. In this presentation, we will review the evidence and present an overview of the HRP Risk of Cardiovascular Disease and Other Degenerative Tissue Effects from Radiation Exposure.

  16. Radiation and other risk issues in Norwegian newspapers ten years after Chernobyl

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Aa.; Reitan, J.B.; Toennesen, A.; Waldahl, R.

    1997-09-01

    Content analysis of risk articles has been performed in 1996 for five Norwegian newspapers four weeks before and four weeks after the 10th anniversary of the Chernobyl accident in 1986. The main focus has been on radiation and/or nuclear risks. The report is part of an international project on risk perception and communication. 94 refs.

  17. Radiation and other risk issues in Norwegian newspapers ten years after Chernobyl

    International Nuclear Information System (INIS)

    Nilsson, Aa.; Reitan, J.B.; Toennesen, A.; Waldahl, R.

    1997-09-01

    Content analysis of risk articles has been performed in 1996 for five Norwegian newspapers four weeks before and four weeks after the 10th anniversary of the Chernobyl accident in 1986. The main focus has been on radiation and/or nuclear risks. The report is part of an international project on risk perception and communication. 94 refs

  18. Environmental radiation: basic principles, biological facts, potential risks

    International Nuclear Information System (INIS)

    Rodemann, H.P.

    2000-01-01

    This book describes the complex processes that underlie the effects of different types of radiation at the cellular, organ and organismic level. Technical terms central to the subject matter are printed in italicize and explained in a glossary along with all physical quantities and dimensional units referred to. Through a systematic presentation of various aspects of the effects of environmental radiation on humans the author has endeavoured to make it clear that any discussion on potential health hazards must be conducted specific to the type of radiation in question. Furthermore, to study these issues meaningfully one must have a knowledge of the scientific basis of interactions between the various types of radiation and biological systems and be able to assess the relative impact of environmental radiation compared with other environmental health hazards

  19. Risk of cataract among medical staff in neurosurgical department occupationally exposed to radiation

    International Nuclear Information System (INIS)

    Stankova-Mileva, I.; Vassileva, J.; Djounova, J.

    2012-01-01

    In this study we present the risk of cataract among medical staff in neurosurgical department occupationally exposed to radiation compared to those of non-radiation workers. Cataract is the most common degenerative opacity of the crystalline lens developing with aging. Other risk factors for cataract are: infrared and ultraviolet radiation, systemic diseases (diabetes, hypertonic disease), eye diseases (glaucoma, high myopia), drugs (steroids), etc. High risk of developing cataract we find among staff occupationally exposed to radiation during operations - interventional cardiologists and neurosurgeons. This study includes 30 people between 33 and 60 years of age working in neurosurgical department and control group (the same amount and age of people not exposed to radiation in their work). After visual acuity measurement, the lens was examined by retroillumination method (red reflex) and using a bio microscope. The patients were asked for presence of ocular and systemic diseases, eye trauma, drug, alcohol and tobacco abuse and for how many years they work in this department. There was one case with cataract among neurosurgeons. The doctor doesn't have eye or systemic diseases, doesn't take any drugs and is not alcohol or tobacco abuser. In the control group there were two persons with subcapsular cataract but they have diabetes. Radiation is one of the risk factors for cataract. Continuing of this epidemiological survey will provide further knowledge on the potential risk of occupational radiation-induced cataract among neurosurgical staff and will contribute for optimization of radiation protection. (authors)

  20. Multidisciplinary European Low Dose Initiative (MELODI). Strategic research agenda for low dose radiation risk research

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzer, M. [Federal Office for Radiation Protection, BfS, Department of Radiation Protection and Health, Neuherberg (Germany); Auvinen, A. [University of Tampere, Tampere (Finland); STUK, Helsinki (Finland); Cardis, E. [ISGlobal, Barcelona Institute for Global Health, Barcelona (Spain); Durante, M. [Institute for Fundamental Physics and Applications, TIFPA, Trento (Italy); Harms-Ringdahl, M. [Stockholm University, Centre for Radiation Protection Research, Stockholm (Sweden); Jourdain, J.R. [Institute for Radiological Protection and Nuclear Safety, IRSN, Fontenay-aux-roses (France); Madas, B.G. [MTA Centre for Energy Research, Environmental Physics Department, Budapest (Hungary); Ottolenghi, A. [University of Pavia, Physics Department, Pavia (Italy); Pazzaglia, S. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Rome (Italy); Prise, K.M. [Queens University Belfast, Belfast (United Kingdom); Quintens, R. [Belgian Nuclear Research Centre, SCK-CEN, Mol (Belgium); Sabatier, L. [French Atomic Energy Commission, CEA, Paris (France); Bouffler, S. [Public Health England, PHE, Chilton (United Kingdom)

    2018-03-15

    MELODI (Multidisciplinary European Low Dose Initiative) is a European radiation protection research platform with focus on research on health risks after exposure to low-dose ionising radiation. It was founded in 2010 and currently includes 44 members from 18 countries. A major activity of MELODI is the continuous development of a long-term European Strategic Research Agenda (SRA) on low-dose risk for radiation protection. The SRA is intended to identify priorities for national and European radiation protection research programs as a basis for the preparation of competitive calls at the European level. Among those key priorities is the improvement of health risk estimates for exposures close to the dose limits for workers and to reference levels for the population in emergency situations. Another activity of MELODI is to ensure the availability of European key infrastructures for research activities, and the long-term maintenance of competences in radiation research via an integrated European approach for training and education. The MELODI SRA identifies three key research topics in low dose or low dose-rate radiation risk research: (1) dose and dose rate dependence of cancer risk, (2) radiation-induced non-cancer effects and (3) individual radiation sensitivity. The research required to improve the evidence base for each of the three key topics relates to three research lines: (1) research to improve understanding of the mechanisms contributing to radiogenic diseases, (2) epidemiological research to improve health risk evaluation of radiation exposure and (3) research to address the effects and risks associated with internal exposures, differing radiation qualities and inhomogeneous exposures. The full SRA and associated documents can be downloaded from the MELODI website (http://www.melodi-online.eu/sra.html). (orig.)

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

    International Nuclear Information System (INIS)

    Kesavan, P.C.; Devasagayam, T.P.A.

    1997-01-01

    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)

  2. A radiation protection training program with a focus on communicating risk

    International Nuclear Information System (INIS)

    Clement, C.H.; Zelmer, R.L.; Tourneur, F.

    2000-01-01

    Radiation protection training is generally provided to promote a radiologically safe work environment, and to help ensure that doses are kept as low as reasonably achievable. In many cases, this reason makes good sense. Radiological risk can often be a significant concern when working with radioactive materials or radiation-emitting devices. However, in conducting the work of the Low-Level Radioactive Waste Management Office, it is often the case that the perception of radiological risk is of greater concern that the radiological risk itself. In this case, radiation protection training can serve another equally important purpose. It can be used to convey, in a balanced manner, the actual radiological risks associated with the work, and to put those risks in perspective. For individuals who are not familiar with radiation safety, effective radiation protection training that focuses on risk communication can reduce the level of concern surrounding work to be performed. This, in turn, can have an overall positive impact on the efficiency of the work, on goodwill within the community where the work is taking place, and even on the overall safety of those conducting the work. The radiation protection training program developed and implemented by the Low-Level Radioactive Waste Management Office is described in the context of other, more traditional radiation protection training programs. (author)

  3. Risk of radiation-induced cancer at low doses and low dose rates for radiation protection purposes

    International Nuclear Information System (INIS)

    1995-01-01

    The aim of this report is to provide an updated, comprehensive review of the data available for assessing the risk of radiation-induced cancer for radiation protection purposes. Particular emphasis is placed on assessing risks at low doses and low dose rates. The review brings together the results of epidemiological investigations and fundamental studies on the molecular and cellular mechanisms involved in radiation damage. Additionally, this information is supplemented by studies with experimental animals which provide further guidance on the form of the dose-response relationship for cancer induction, as well as on the effect of dose rate on the tumour yield. The emphasis of the report is on cancer induction resulting from exposure to radiations with a low linear energy transfer (LET). The work was performed under contract for the Institut de Protection et de Surete Nucleaire, Fontenay-aux-Roses, Paris, France, whose agreement to publish is gratefully ackowledged. It extends the advice on radiation risks given in Documents of the NRPB, 4 No. 4 (1993). (Author)

  4. Operationalisation of the model 'risk-sovereignty' in the field of radiation protection. Final report

    International Nuclear Information System (INIS)

    Renn, Ortwin; Ruddat, Michael; Sautter, Alexander

    2007-01-01

    The central aim of the BfS research project titled ''operationalization of the 'risk sovereignty model' with special consideration to lifestyle and value approaches as a basis for risk communication in the field of radiation protection'' was the identification of suitable measures to enhance the degree of risk sovereignty of the German population with regard to radiation risks (mobile telephony, nuclear power, ultraviolet radiation and X-rays). This requires the development of a measuring instrument for capturing the prevailing degree of risk sovereignty in the whole population or in certain subgroups with regard to radiation risks empirically. In the first two phases of the project suitable instruments for the construct ''risk sovereignty'' have been developed. Furthermore a value-typology for the identification of different groups of persons as well as independent variables likely to have an influence on 'risk sovereignty' (information behavior, communication or participation intention) were included in the study. The empirical research is divided into a quantitative and a qualitative inquiry. Based on the empirical studies, a guidance document to improve the cognitive capability of people to build up risk sovereignty, in particular in relation to radiation was developed. For the three types of respondents, different strategies were recommended taking into account their needs and information seeking behavior

  5. Fundamentals of risk/benefit analysis in radiation uses in preventive medicine

    International Nuclear Information System (INIS)

    Stieve, F.E.

    1977-01-01

    The term 'risk' stems from the insurance branch. It serves to estimate the probability of making statements about future events on the basis of events which have taken place. Risk estimations are increasingly being made in medicine, especially for determining the advantages and dangers brought to the population by preventive measures. The international radiation protection commission has, for some time, been expressing the dangers of ionising radiation in terms of risk and using these terms as basis for the dose limit values it determined for the professional and general population. This paper deals with possibilities of determining risks in preventive medicine. For doing this, acceptable risk values must be determined and risks resulting from diseases, esp. from those which were not recognized in time, must be compared with those resulting from the application of ionising radiation. (orig.) [de

  6. Is energy imparted a good measure of the radiation risk associated with CT examinations

    International Nuclear Information System (INIS)

    Huda, W.

    1984-01-01

    The dose distribution in a Rando phantom has been measured for typical EMI 5005 CT scans of the head, chest, abdomen and pelvis. These dose distributions have been used to generate quantitative estimates of the somatic and genetic radiation risks associated with these CT examinations and also to measure the total energy imparted during each scan. A comparison has been made between the radiation risk estimates and the energy imparted measurements. The energy imparted measurements are not a good indicator of the somatic and/or genetic risks when one type of CT scan is compared with another. However, for a given type of scan, the energy imparted may be a reasonable indicator of the relative somatic risks associated with different CT examinations. Considerable care should be taken when interpreting and using any measured value of energy imparted in a radiological examination since published values of the risk per unit energy imparted can significantly underestimate the radiation risk. (author)

  7. Stroke After Radiation Therapy for Head and Neck Cancer: What Is the Risk?

    Energy Technology Data Exchange (ETDEWEB)

    Arthurs, Erin [Department of Public Health Sciences, Queen' s University, Kingston, Ontario (Canada); Hanna, Timothy P. [Division of Cancer Care and Epidemiology, Queen' s University, Kingston, Ontario (Canada); Department of Oncology, Queen' s University, Kingston, Ontario (Canada); Zaza, Khaled [Department of Oncology, Queen' s University, Kingston, Ontario (Canada); Peng, Yingwei [Department of Public Health Sciences, Queen' s University, Kingston, Ontario (Canada); Hall, Stephen F., E-mail: sfh@queensu.ca [Division of Cancer Care and Epidemiology, Queen' s University, Kingston, Ontario (Canada); Department of Otolaryngology, Queen' s University, Kingston, Ontario (Canada)

    2016-11-01

    Purpose: A retrospective population-based cohort study was conducted to determine the risk of ischemic stroke with respect to time, associated with curative radiation therapy in head and neck squamous cell carcinomas (HNSCC). Methods and Materials: On the basis of data from the Ontario Cancer Registry and regional cancer treatment centers, 14,069 patients were identified with diagnoses of squamous cell carcinoma of the oral cavity, larynx, and pharynx who were treated for cure between 1990 and 2010. Hazards of stroke and time to stroke were examined, accounting for the competing risk of death. Stroke risk factors identified through diagnostic and procedural administrative codes were adjusted for in the comparison between treatment regimens, which included surgery alone versus radiation therapy alone and surgery alone versus any exposure to radiation therapy. Results: Overall, 6% of patients experienced an ischemic stroke after treatment, with 5% experiencing a stroke after surgery, 8% after radiation therapy alone, and 6% after any exposure to radiation therapy. The cause-specific hazard ratios of ischemic stroke after radiation therapy alone and after any exposure to radiation therapy compared with surgery were 1.70 (95% confidence interval [CI]: 1.41-2.05) and 1.46 (95% CI: 1.23-1.73), respectively, after adjustment for stroke risk factors, patient factors, and disease-related factors. Conclusions: Radiation therapy was associated with an increased risk of ischemic stroke compared with surgery alone: for both radiation therapy alone and after all treatment modalities that included any radiation treatment were combined. Because of a shift toward a younger HNSCC patient population, our results speak to the need for adequate follow-up and survivorship care among patients who have been treated with radiation therapy. Advances in treatment that minimize chronic morbidity also require further evaluation.

  8. Radiation

    International Nuclear Information System (INIS)

    Winther, J.F.; Ulbak, K.; Dreyer, L.; Pukkala, E.; Oesterlind, A.

    1997-01-01

    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

  9. Dosimetric analysis of varying cord planning organ at risk volume in spine stereotactic body radiation therapy

    Directory of Open Access Journals (Sweden)

    Dawn Owen, MD, PhD

    2016-01-01

    Conclusion: Current guidelines may overestimate the risk of myelopathy from spine SBRT. The current study's population included both radiation-naïve and retreatment cases, but no myelopathy was observed despite exceeding recommended spine limits.

  10. Improvements to the Ionizing Radiation Risk Assessment Program for NASA Astronauts

    Science.gov (United States)

    Semones, E. J.; Bahadori, A. A.; Picco, C. E.; Shavers, M. R.; Flores-McLaughlin, J.

    2011-01-01

    To perform dosimetry and risk assessment, NASA collects astronaut ionizing radiation exposure data from space flight, medical imaging and therapy, aviation training activities and prior occupational exposure histories. Career risk of exposure induced death (REID) from radiation is limited to 3 percent at a 95 percent confidence level. The Radiation Health Office at Johnson Space Center (JSC) is implementing a program to integrate the gathering, storage, analysis and reporting of astronaut ionizing radiation dose and risk data and records. This work has several motivations, including more efficient analyses and greater flexibility in testing and adopting new methods for evaluating risks. The foundation for these improvements is a set of software tools called the Astronaut Radiation Exposure Analysis System (AREAS). AREAS is a series of MATLAB(Registered TradeMark)-based dose and risk analysis modules that interface with an enterprise level SQL Server database by means of a secure web service. It communicates with other JSC medical and space weather databases to maintain data integrity and consistency across systems. AREAS is part of a larger NASA Space Medicine effort, the Mission Medical Integration Strategy, with the goal of collecting accurate, high-quality and detailed astronaut health data, and then securely, timely and reliably presenting it to medical support personnel. The modular approach to the AREAS design accommodates past, current, and future sources of data from active and passive detectors, space radiation transport algorithms, computational phantoms and cancer risk models. Revisions of the cancer risk model, new radiation detection equipment and improved anthropomorphic computational phantoms can be incorporated. Notable hardware updates include the Radiation Environment Monitor (which uses Medipix technology to report real-time, on-board dosimetry measurements), an updated Tissue-Equivalent Proportional Counter, and the Southwest Research Institute

  11. A perspective on the radiation protection problem and risk analysis for the nuclear era

    International Nuclear Information System (INIS)

    Vohra, K.G.

    1977-01-01

    The projected large scale use of nuclear energy and sources of ionizing radiations would involve the radiation exposure of larger numbers of occupational workers, individuals and groups in the population, and the population-at-large. There is an urgent need for projecting these exposures in a proper perspective, by comparing the associated risks with the risks from alternative energy sources, e.g. with those from the combustion products released by the fossil fuel plants. A comparative study of the risk of cancer mortality from radiations and airborne chemical pollutants has been presented. Radiation risk data is given in terms of cancer deaths per million per year for a given dose rate, based on the human experience. The lung cancer risks of the combined products of coal burning and a specific carcinogen benzo(a)pyrene have also been estimated, based on the extensive epidemiological data available for different countries. Using the dose-response data for radiation exposure at different annual dose rates, dose equivalents of chemical pollutants have been determined. Whereas the estimated risk for power reactor effluents is found to be only 1% of the risk at the ICRP dose limits for ionizing radiations, the current urban levels of benzo(a)pyrene (a product of fossil fuel combustion) are already large enough to present a 100 fold higher risk, equivalent to that of the ICRP dose limit for ionizing radiations. Comparison shows that percentage contributions to the overall risk are 0.06, 5.5 and 19.0 for nuclear power, fossil fuel pollutant benzo(a)pyrene (per ng/m 3 ) and total coal pollutants (per ton/capita consumption), respectively. Risk estimates for different stages of the nuclear fuel cycle, including the fast breeder reactor fuel cycle, are also presented

  12. Natural and anthropogeneous radiation in the Erzgebirge: Risk factor radon

    International Nuclear Information System (INIS)

    Jacobi, W.

    1992-01-01

    The geological formations in the saxoinian-thuringian low mountain range contain rocks with a relatively high share of uranium ( 238 U) and its follow-up product radium ( 226 Ra). Independent of mining this results in increased radiation levels to which the local population has always been exposed. Natural radiation levels may, of course, vary strongly from one location to the next and therefore human exposure varies accordingly. (orig.) [de

  13. Radiation risks in the 20. Century: reality, illusions and ethics

    International Nuclear Information System (INIS)

    Jaworowski, Z.

    1998-01-01

    Average global natural ionizing radiation dose for man is 2.4 mSv/year ranging in various geographical regions from about 1 to 220 mSv/year. At the dawn of life this dose was by a factor of three to five higher than now. The entire man-made contribution to radiation dose is only about 0.2% of natural radiation. From medical radiodiagnostics the average global dose is about 0.5 mSv/year, from nuclear explosions was in 1963 <0.2 mSv/year, from Chernobyl accident was in 1986-1987 0.05 mSv/year, and from nuclear power in 1995 about 0.007 mSv/year. Radiation is rather a weak noxious agent as compared with other natural and man-made hazards. Radiophobia has its source not in real peace-time radiation hazard to population, but in politics and group interests. Current excessive radiation protection standards, e.g. 1mSv/year, are based on an arbitrary assumption on linearity and a lack of threshold in dose/effect relationship, and on ignoring the beneficial effects of low doses of radiation. A whole body dose rate of 1mSv/year causes about 2 DNA damages in each cell. This can be compared with 70 million natural DNA damaging events occurring in each cell per year. Regulations based on this assumption lead to the wasting of resources desperately needed to deal with real health problems, and to strangulation of development of environmentally and human friendly nuclear technologies. Radiation standards should be based on 'practical threshold', one below which induction of detectable radiogenic cancers or genetic effects is not expected. (author)

  14. Assessment of radiation-induced cancer risks from the Chernobyl fallout in Finland

    International Nuclear Information System (INIS)

    Servomaa, A.; Komppa, T.; Suomela, M.

    1997-01-01

    Application of detailed radiation risk models to populations affected by radiation doses from the Chernobyl fallout allows forecasting and estimation of the consequences of the accident in countries far from the place of the accident, and comparison of the model estimates with epidemiological observations in low-dose conditions among large populations. 14 refs, 11 figs, 1 tab

  15. Assessment of radiation-induced cancer risks from the Chernobyl fallout in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Servomaa, A; Komppa, T; Suomela, M [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

    1997-09-01

    Application of detailed radiation risk models to populations affected by radiation doses from the Chernobyl fallout allows forecasting and estimation of the consequences of the accident in countries far from the place of the accident, and comparison of the model estimates with epidemiological observations in low-dose conditions among large populations. 14 refs, 11 figs, 1 tab.

  16. An update on standards for radiation in the environment and associated estimates of risk

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1989-01-01

    This presentation reviews current and proposed standards, recommendations, and guidances for limiting routine radiation exposures of the public, and estimates the risk corresponding to standards, recommendations, and guidances. These estimates provide a common basis for comparing different criteria for limiting public exposures to radiation, as well as hazardous chemicals

  17. The 15-Country Collaborative Study of Cancer Risk among Radiation Workers in the Nuclear Industry

    DEFF Research Database (Denmark)

    Cardis, E; Vrijheid, M; Blettner, M

    2007-01-01

    A 15-Country collaborative cohort study was conducted to provide direct estimates of cancer risk following protracted low doses of ionizing radiation. Analyses included 407,391 nuclear industry workers monitored individually for external radiation and 5.2 million person-years of follow-up. A sign...

  18. Effective Patient Education in Medical Imaging: Public Perceptions of Radiation Exposure Risk.

    Science.gov (United States)

    Ludwig, Rebecca L.; Turner, Lori W.

    2002-01-01

    In a cross-sectional survey of 200 adults, less than half agreed with experts on the risks of radiation exposure; 75-90% thought that medical imaging providers should be highly regulated; and less than one-quarter knew that most radiation damage is not permanent. (SK)

  19. Proceedings of the fourth JAEA-US EPA workshop on radiation risk assessment

    International Nuclear Information System (INIS)

    Endo, Akira; Boyd, Michael

    2007-02-01

    This report is the proceedings of the fourth workshop jointly organized by the Japan Atomic Energy Agency (JAEA) and the United States Environmental Protection Agency (US EPA) under the terms of agreement for cooperation in the field of radiation protection. The workshop was sponsored by the Nuclear Science and Engineering Directorate and was held at the Nuclear Science Research Institute, the Tokai Research and Development Center, JAEA, on November 7-8, 2006. The objective of the workshop was to exchange and discuss recent information on radiation effects, radiation risk assessment, radiation dosimetry, emergency response, radiation protection standards, and waste management. Twenty-two papers were presented by experts from JAEA, US EPA, the National Academies, Oak Ridge National Laboratory, Washington State University and the US Nuclear Regulatory Commission. Three keynotes addressed research on radiation effects and radiation protection at JAEA, the latest report on health risks from exposure to low levels of ionizing radiation published by the National Research Council (BEIR VII Phase 2), and recent developments in Committee 2 for the forthcoming recommendations of the International Commission on Radiological Protection (ICRP). The workshop provided a good opportunity for identifying future research needed for radiation risk assessment. The 22 of the presented papers are indexed individually. (J.P.N.)

  20. The relevance of animal experimental results for the assessment of radiation genetic risks in man

    International Nuclear Information System (INIS)

    Stephan, G.

    1981-01-01

    No suitable data are available from man for the quantitative assessment of genetic radiation risk. Therefore, the results from experiments on animals must be utilized. Two hypotheses are presented here in drawing analogical conclusions from one species to another. Although the extrapolation of results from animal experiments remains an open question, the use of experimental results from mice seems to be justified for an assessment of the genetic radiation risk in man. (orig.) [de

  1. A method for calculating effective lifetime risk of radiation-induced cancer from screening mammography

    International Nuclear Information System (INIS)

    Ali, R.M.; England, A.; McEntee, M.F.; Hogg, P.

    2015-01-01

    Purpose: To propose a method for evaluating the effective lifetime risk of radiation-induced cancer from screening mammography and to present initial data for the UK National Breast Screening Programme. Material and methods: The imaging was undertaken using a Hologic Selenia full field digital mammographic unit. The proposed method utilises an ATOM phantom containing thermoluminescent dosimeters and a perspex-polyethylene breast phantom to measure organ doses during a standard four view screening mammogram. Effective dose was calculated and effective risk was modelled for a range of client ages. The total lifetime effective risk was then calculated for the UK national screening programme. Calculation of effective risk includes the radiation dose to examined and contralateral breasts in addition to other body organs; this is an advantage over the mean glandular dose. Results: The contralateral breast, thyroid, thymus, brain, lung, salivary glands, and bone marrow all receive more than 1 μGy radiation dose during screening mammography. A major difference exists for total effective lifetime risk of radiation-induced cancer between clients with average and high breast cancer risk. Differences are attributed to the commencement age of screening and time interval between screens. Conclusion: This study proposes a method to evaluate effective lifetime risk of radiation-induced cancer from screening mammography in order to compare different mammography screening programmes. - Highlights: • We proposed a method for the calculation of radiation-induced cancer from screening mammography. • We measured the radiation absorbed dose of different organs during screening mammography. • There are major differences between mammography screening programme categories with regard to radiation effective risk.

  2. Radiation risk perception: a discrepancy between the experts and the general population

    International Nuclear Information System (INIS)

    Perko, Tanja

    2014-01-01

    Determining the differences in the perception of risks between experts who are regularly exposed to radiation, and lay people provides important insights into how potential hazards may be effectively communicated to the public. In the present study we examined lay people's (N = 1020) and experts' (N = 332) perception of five different radiological risks: nuclear waste, medical x-rays, natural radiation, an accident at a nuclear installation in general, and the Fukushima accident in particular. In order to link risk perception with risk communication, media reporting about radiation risks is analysed using quantitative and qualitative content analyses. The results showed that experts perceive radiological risks differently from the general public. Experts' perception of medical X-rays and natural radiation is significantly higher than in general population, while for nuclear waste and an accident at a nuclear installation, experts have lower risk perception than the general population. In-depth research is conducted for a group of workers that received an effective dose higher than 0.5 mSv in the year before the study; for this group we identify predictors of risk perception. The results clearly show that mass media don't use the same language as technical experts in addressing radiological risks. The study demonstrates that the discrepancy in risk perception and the communication gap between the experts and the general population presents a big challenge in understanding each other

  3. Radiation induced bystander effects: mechanisms and implication for low dose radiation risk assessment

    International Nuclear Information System (INIS)

    Hei, T.L.; Randers-Pehrson, G.; Zhou, H.

    2003-01-01

    Using a precision microbeam to target an exact fraction of cells in a population and irradiated their nuclei with exactly one alpha particle each, we found that the frequencies of induced mutations and chromosomal changes in populations where some known fractions of nuclei were hit are consistent with non-hit cells contributing significantly to the response. In fact, irradiation of 10% of a mammalian cell population with a single alpha particle per cell results in a mutant yield similar to that observed when all of the cells in the population are irradiated. Although the bystander observations have been well established, the underlying mechanism(s) remain largely unknown. There are indications that multiple pathways are involved in the bystander phenomenon and different cell types respond differently to the bystander signaling. In confluent monolayers, there is evident that gap junctional communication is crucial in mediating the bystander effect whereas reactive oxygen and reactive nitrogen species have been implicated as the mediating molecules in sub-confluent cultures. Although p53 is not necessary for the expression of bystander effect, there is evident that repair deficient cells may express a higher bystander response. Using cDNA microarrays, a number of cellular signaling genes have been shown to be differentially expressed among bystander cells. The functional roles of these genes in the bystander effect will be discussed. The bystander observations imply that the relevant target for various radiobiological endpoints is larger than an individual cell and suggest a need to reconsider the validity of the linear extrapolation in making risk estimate for low dose radiation exposure. (Work supported by NIH grants CA 49062 and CA-RR11623)

  4. Diagnostic Dental Radiation Risk during Pregnancy: Awareness among General Dentists in Tabriz

    Directory of Open Access Journals (Sweden)

    Tahmineh Razi

    2011-06-01

    Full Text Available Background and aims. Pregnant women often do not receive proper dental care in emergency visits due to a lack of awareness of the effect of radiation doses and the involved risks for the fetus. The aim of the present study was to assess the awareness of general dentists practicing in Tabriz, Iran, of the risks involved during exposure to diagnostic dental radiation in pregnant women. Materials and methods. In this descriptive/cross-sectional study, 250 general dentists, who had attended continuing education courses under the supervision of the Faculty of Dentistry, filled out questionnaires on their awareness of radiation risks. Data was analyzed by Spearman's correlation coefficient test. Results. The mean of correct answers was 6.47±1.66, with the least and highest correct answers of 2 and 10, respectively. The highest and the lowest levels of awareness were related to the use of a lead apron (92% and a long rectangular collimator (3.2%, respectively. There was a statistically significant correlation between the age of practitioners and awareness of radiation risks (P=0.02. However, no statistically significant correlation was observed between job experience (P=0.25 and the number of continuing education courses attended (P=0.16 and awareness of radiation risks. Conclusion. The studied population of dentists does not seem to have the sufficient knowledge regarding the diagnostic dental radiation risk during pregnancy. Further educational courses and pamphlets are recommended for increasing their awareness of this subject.

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

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    2005-01-01

    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)

  6. Prenatal exposure to atomic radiation and brain damage

    International Nuclear Information System (INIS)

    Otake, Masanori; Yoshimaru, Hiroshi; Schull, W.J.

    1989-01-01

    The purpose of this study was threefold: to evaluate the risks to the developing human embryonic and fetal brain of exposure to ionizing radiation using the new DS86 doses; to compare the estimate of risk so derived with those based on the earlier T65DR doses; and to present the evidence bearing on a threshold in the low dose region under the two systems of dosimetry, especially for the data on clinically recognized severe mental retardation (SMR) and seizure. Regarding dose-related SMR, IQ scores, school performance and seizures, there was a high temporal correspondence between the T65DR and DS86 dosimetry systems. A linear no-threshold model with both dosimetry systems also revealed that a significant increase in SMR was observed when the subjects were exposed in the uterus during the periods both 8-15 and 16-25 weeks after fertilization. A threshold in the low dose region was not suggested with the T65DR fetal absorbed doses, but suggested with the DS86 uterine absorbed doses. However, the location or even the existence of a threshold during both periods after fertilization was difficult to demonstrate statistically with the DS86 uterine absorbed doses. When two probable nonradiation-related cases of Down's syndrome were excluded, a threshold with a lower bound was suggested to be observed in the 0.10-0.20 Gy region. Both dosimetries indicated a threshold in the dose-response function for mental retardation in the 16-25 week period, probably within the range from 0.23 to 0.70 Gy. The seizure data provided no persuasive evidence of a threshold during the 8-15 week period after fertilization; the 95% lower bound of the estimate of the threshold included zero. Finally, although the mean IQ scores and the mean school performances in the low dose region were similar to the values in the control group, particularly with doses under 0.10 Gy, evidence for a threshold is not compelling. (N.K.)

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

    International Nuclear Information System (INIS)

    Akiba, Suminori

    2010-01-01

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

  8. Education on radiation risk in primary and middle schools in Japan

    International Nuclear Information System (INIS)

    Tada, Junichiro

    1999-01-01

    The (ionizing) radiation appears in the text of social studies in primary and middle school curriculums. The radiation is almost not involved in the text of science. Consequently, pupils know only the examples of disasters caused by the excessive radiation and have no chance to learn real natures and characters of the radiation after the compulsory education course. This situation means difficulties to give a lesson on the radiation risk. Erupting volcanoes, earthquakes and lightning are similar in danger of the excessive radiations. However, few pupils have a supernatural threat for these phenomena that ancient people do, because they have the adequate knowledge for theses after primary and middle school curriculums. This situation is a full of contrast to the case of the radiation on the major sensitivity that they have. The point is to let pupils learn that the radiation is one of the natural phenomena like heat and electricity, those exist before a birth of human being. Natural ionizing radiation sources are recommended for the first teaching material. Pupils know that the radiation is one of commonplace events, then. Radiation is one of the universe elements. Consequently, they will know that human being is evolving with the radiation exposures. The general perception on safety and danger is a kind of antinomy in Japan. A person who is following antinomy accepts only zero risk. Preschool educations will be needed to grow out of an antinomy concept on safety and danger, and to recognize the reality. A comprehensive knowledge should be provided with a full balance for the perception of risk. For an example, prejudices against HIV patients still remain in Japan, due to many belated campaigns on weak infection. People remember danger, and they do not remember the fact that is not dangerous. (Y. Tanaka)

  9. Education on radiation risk in primary and middle schools in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Junichiro [Japan Synchrotron Radiation Research Institute (SPring-8), Mikaduki, Hyogo (Japan)

    1999-09-01

    The (ionizing) radiation appears in the text of social studies in primary and middle school curriculums. The radiation is almost not involved in the text of science. Consequently, pupils know only the examples of disasters caused by the excessive radiation and have no chance to learn real natures and characters of the radiation after the compulsory education course. This situation means difficulties to give a lesson on the radiation risk. Erupting volcanoes, earthquakes and lightning are similar in danger of the excessive radiations. However, few pupils have a supernatural threat for these phenomena that ancient people do, because they have the adequate knowledge for theses after primary and middle school curriculums. This situation is a full of contrast to the case of the radiation on the major sensitivity that they have. The point is to let pupils learn that the radiation is one of the natural phenomena like heat and electricity, those exist before a birth of human being. Natural ionizing radiation sources are recommended for the first teaching material. Pupils know that the radiation is one of commonplace events, then. Radiation is one of the universe elements. Consequently, they will know that human being is evolving with the radiation exposures. The general perception on safety and danger is a kind of antinomy in Japan. A person who is following antinomy accepts only zero risk. Preschool educations will be needed to grow out of an antinomy concept on safety and danger, and to recognize the reality. A comprehensive knowledge should be provided with a full balance for the perception of risk. For an example, prejudices against HIV patients still remain in Japan, due to many belated campaigns on weak infection. People remember danger, and they do not remember the fact that is not dangerous. (Y. Tanaka)

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  11. [Regulatory radiation risks' for the population and natural objects within the Semipalatinsk Test Site].

    Science.gov (United States)

    Spiridonov, S I; Teten'kin, V L; Mukusheva, M K; Solomatin, V M

    2008-01-01

    Advisability of using risks as indicators for estimating radiation impacts on environmental objects and humans has been jusified. Results are presented from identification of dose burdens distribution to various cohorts of the population living within the Semipalatinsk Test Site (STS) and consuming contaminated farm products. Parameters of dose burden distributions are estimated for areas of livestock grazing and the most contaminated sectors within these areas. Dose distributions to meadow plants for the above areas have been found. Regulatory radiation risks for the STS population and meadow ecosystem components have been calculated. Based on the parameters estimated, levels of radiation exposure of the population and herbaceous plants have been compared.

  12. Risk and value of conventional myelography with regard to radiation exposure of the patient

    International Nuclear Information System (INIS)

    Hentschel, F.

    1989-01-01

    To estimate the effective equivalent dose with reference to the area under examination and the foils employed, fifty patients underwent conventional diagnostic myelography, after which, by means of thermoluminescence surface dosimetry, the mean organ dose was ascertained from the radiation field size, using the computer program ORDOS. Effective equivalent dose can be used to determine the inherent risk of radiation injury involved. The risk-benefit ratios obtained would suggest that conventional myelography, prospectively in the form of digital myelography, and spinal computer tomography are not opposing but complementary approaches to spinal diagnosis. Spinal NMR imaging must not be discussed under the aspect of radiation exposure but under the aspect of availability. (author)

  13. Epidemiological methods of assessing risks from low level occupational exposure to ionising radiation

    International Nuclear Information System (INIS)

    Reissland, J.A.

    1982-01-01

    The resolution of radiation-attributable malignancies from the background of malignancies which are responsible for about 20% of all deaths in the Western world, presents a formidable challenge to epidemiological methods. Some of the major difficulties facing those with the task of estimating the risks associated with exposure to low level ionising radiation are discussed, particularly in the context of radiological protection. Some of the studies currently in progress are summarised and suggestions are made for other work which may help to contribute to a better understanding of the quantitative aspects of radiation risk assessment. (author)

  14. Assessing risks from occupational exposure to low-level radiation

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1989-06-01

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

  15. Radiobiology in clinical radiation therapy: Long term risks - Carcinogenic, hereditary, and teratogenetic effects

    International Nuclear Information System (INIS)

    Brenner, David J.

    1997-01-01

    The long-term risks induced by radiation are of much concern to patients and clinicians alike. As an example, perceived radiation risks are frequently cited in a woman's decision to choose a radical mastectomy over lumpectomy + radiation. In consequence, the actual radiation risks are often considerably overstated, or unreasonably downplayed. In this lecture we will discuss just what is known about the long term risks following radiotherapy, both from the human experience and from the laboratory. We will discuss risks both to the patient and to radiotherapy personnel. A good deal is known about the carcinogenic effects of high and low doses of radiation, in large part thanks to the careful study of the survivors of the atomic bombing in Japan, as well as studies of individuals exposed to medical x rays. It is possible to make an estimate, which is probably good to within a factor of, perhaps, three to five, of the cancer risks faced by a patient of a particular age and sex who is going to undergo a particular radiotherapeutic regimen. It is also possible to make an estimate of the risks faced by radiotherapy and nursing staff exposed to low doses. Brachytherapy related risk estimates are likely to be somewhat more uncertain, due to the poorly known sparing effects of the low dose rates used; for the radiotherapy personnel in brachytherapy, because of the doses which can be received, the risks can be quite significant. A recent complication in external-beam radiotherapy is the advent of high-energy linacs, which can produce a significant fast neutron dose which, dose for dose, may be ten to fifty times more carcinogenic than gamma rays. Data relating to the risks of hereditary effects of radiation come almost entirely from laboratory experiments in animals. Studies involving several million mice form the basis of most of our current understanding of hereditary effects. The results of these studies indicate that radiation is a relatively inefficient mutagen. The

  16. Radiobiology in clinical radiation therapy - Part IV: Long term risks - Carcinogenic, hereditary, and teratogenetic effects

    International Nuclear Information System (INIS)

    Brenner, David J.

    1996-01-01

    The long-term risks induced by radiation are of much concern to patients and clinicians alike. As an example, perceived radiation risks are frequently cited in a woman's decision to choose a radical mastectomy over lumpectomy + radiation. In consequence, the actual radiation risks are often considerably overstated, or unreasonably downplayed. In this lecture we will discuss just what is known about the long term risks following radiotherapy, both from the human experience and from the laboratory. We will discuss risks both to the patient and to radiotherapy personnel. A good deal is known about the carcinogenic effects of high and low doses of radiation, in large part thanks to the careful study of the survivors of the atomic bombing in Japan, as well as studies of individuals exposed to medical x rays. It is possible to make an estimate, which is probably good to within a factor of, perhaps, three to five, of the cancer risks faced by a patient of a particular age and sex who is going to undergo a particular radiotherapeutic regimen. It is also possible to make an estimate of the risks faced by radiotherapy and nursing staff exposed to low doses. Brachytherapy related risk estimates are likely to be somewhat more uncertain, due to the poorly known sparing effects of the low dose rates used; for the radiotherapy personnel in brachytherapy, because of the doses which can be received, the risks can be quite significant. A recent complication in external-beam radiotherapy is the advent of high-energy linacs, which can produce a significant fast neutron dose which, dose for dose, may be ten to fifty times more carcinogenic than gamma rays. Data relating to the risks of hereditary effects of radiation come almost entirely from laboratory experiments in animals. Studies involving several million mice form the basis of most of our current understanding of hereditary effects. The results of these studies indicate that radiation is a relatively inefficient mutagen. The

  17. Risk factors for radiation-induced hypothyroidism: A Literature-Based Meta-Analysis

    DEFF Research Database (Denmark)

    Vogelius, Ivan R; Bentzen, Søren; Maraldo, Maja V

    2011-01-01

    BACKGROUND: A systematic overview and meta-analysis of studies reporting data on hypothyroidism (HT) after radiation therapy was conducted to identify risk factors for development of HT. METHODS: Published studies were identified from the PubMed and Embase databases and by hand-searching published...... reviews. Studies allowing the extraction of odds ratios (OR) for HT in 1 or more of several candidate clinical risk groups were included. A meta-analysis of the OR for development of HT with or without each of the candidate risk factors was performed. Furthermore, studies allowing the extraction......% risk of HT at a dose of 45 Gy but with considerable variation in the dose response between studies. Chemotherapy and age were not associated with risk of HT in this analysis. CONCLUSIONS: Several clinical risk factors for HT were identified. The risk of HT increases with increasing radiation dose...

  18. Study warns of radiation risk in medical imaging

    Science.gov (United States)

    Gwynne, Peter

    2009-10-01

    A study of a million US patients suggests that some who undergo medical imaging could be exposed to more ionizing radiation than those who work with radioactive materials in nuclear power plants. The study, reported in The New England Journal of Medicine (361 849), implies that current exposure to radiation from conventional X-ray equipment as well as computed tomography (CT) and positron-emission tomography (PET) scanners could lead to tens of thousands of extra cases of cancer in the US alone.

  19. Leukaemia risks and exposure to ionizing radiations. ASN seminar, Tuesday, June 9, 2015, report

    International Nuclear Information System (INIS)

    Niel, Jean-Christophe; Samain, Jean-Paul; Colonna, Marc; Maynadie, Marc; Richardson, David; Bey, Pierre; Leuraud, Klervi; Laurier, Dominique; Hemon, Denis; Spycher, Ben; Kosti, Ourania; Bouville, Andre; Grosche, Bernd; Ziegelberger, Gunde; Kesminiene, Ausrele; Clavel, Jacqueline; Smeesters, Patrick; Murith, Christophe

    2015-08-01

    This seminar aims at proposing a review of present knowledge on leukaemia risks for children and adults associated with ionizing radiations, and at sharing knowledge between experts. After an introduction which outlined the interest of the ASN in research issues, and the importance awarded by the ASN to the variety of points of view, a first session addressed leukaemia and exposures to ionizing radiations. The contributions addressed some general aspects (an overview of leukaemia in France, the different types of adult and child leukaemia), leukaemia and acute exposures to ionizing radiations (ionizing radiation and leukaemia among Japanese bomb survivors, risks of leukaemia after radiotherapy), leukaemia and chronic exposures to ionizing radiations (assessment of epidemiological studies for adult chronic exposures). The second session addressed childhood leukaemia and ionizing radiations. The contributions of this second session more particularly addressed the following topics: childhood leukaemia and natural radioactivity (French studies, synthesis of international studies and a new Swiss study), childhood leukaemia and proximity of nuclear base installations (assessment of national and international studies, analysis of cancer risks in populations near nuclear facilities in the US, calculation of dose at the medulla as example of dosimetry of ionizing radiations and leukaemia, conclusions of the 2012 MELODI workshop), childhood leukaemia and scanner (recent results and perspectives), childhood leukaemia and other risk factors (etiology of childhood leukaemia - presentation of French studies initiated by the INSERM, and presentation of studies initiated by BfS)

  20. Assessment of radiation-induced second cancer risks in proton therapy and IMRT for organs inside the primary