Integration of a radiation biomarker into modeling of thyroid carcinogenesis and post-Chernobyl risk assessment.

Science.gov (United States)

Kaiser, Jan Christian; Meckbach, Reinhard; Eidemüller, Markus; Selmansberger, Martin; Unger, Kristian; Shpak, Viktor; Blettner, Maria; Zitzelsberger, Horst; Jacob, Peter

2016-12-01

Strong evidence for the statistical association between radiation exposure and disease has been produced for thyroid cancer by epidemiological studies after the Chernobyl accident. However, limitations of the epidemiological approach in order to explore health risks especially at low doses of radiation appear obvious. Statistical fluctuations due to small case numbers dominate the uncertainty of risk estimates. Molecular radiation markers have been searched extensively to separate radiation-induced cancer cases from sporadic cases. The overexpression of the CLIP2 gene is the most promising of these markers. It was found in the majority of papillary thyroid cancers (PTCs) from young patients included in the Chernobyl tissue bank. Motivated by the CLIP2 findings we propose a mechanistic model which describes PTC development as a sequence of rate-limiting events in two distinct paths of CLIP2-associated and multistage carcinogenesis. It integrates molecular measurements of the dichotomous CLIP2 marker from 141 patients into the epidemiological risk analysis for about 13 000 subjects from the Ukrainian-American cohort which were exposed below age 19 years and were put under enhanced medical surveillance since 1998. For the first time, a radiation risk has been estimated solely from marker measurements. Cross checking with epidemiological estimates and model validation suggests that CLIP2 is a marker of high precision. CLIP2 leaves an imprint in the epidemiological incidence data which is typical for a driver gene. With the mechanistic model, we explore the impact of radiation on the molecular landscape of PTC. The model constitutes a unique interface between molecular biology and radiation epidemiology. © The Author 2016. Published by Oxford University Press.

Three-dimensional dose-response models of risk for radiation injury carcinogenesis

International Nuclear Information System (INIS)

Raabe, O.G.

1988-01-01

The use of computer graphics in conjunction with three-dimensional models of dose-response relationships for chronic exposure to ionizing radiation dramaticly clarifies the separate and interactive roles of competing risks. The three dimensions are average dose rate, exposure time, and risk. As an example, the functionally injurious and carcinogenic responses after systemic uptake of Ra-226 by beagles, mice and people with consequent alpha particle irradiation of the bone are represented by three-dimensional dose-rate/time/response surfaces that demonstrate the contributions with the passage of time of the competing deleterious responses. These relationships are further evaluated by mathematical stripping with three-dimensional illustrations that graphically show the resultant separate contribution of each effect. Radiation bone injury predominates at high dose rates and bone cancer at intermediate dose rates. Low dose rates result in spontaneous deaths from natural aging, yielding a type of practical threshold for bone cancer induction. Risk assessment is benefited by the insights that become apparent with these three-dimensional models. The improved conceptualization afforded by them contributes to planning and evaluating epidemiological analyses and experimental studies

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.

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)

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.

Modified Exponential (MOE) Models: statistical Models for Risk Estimation of Low dose Rate Radiation

International Nuclear Information System (INIS)

Ogata, H.; Furukawa, C.; Kawakami, Y.; Magae, J.

2004-01-01

Simultaneous inclusion of dose and dose-rate is required to evaluate the risk of long term irradiation at low dose-rates, since biological responses to radiation are complex processes that depend both on irradiation time and total dose. Consequently, it is necessary to consider a model including cumulative dose,dose-rate and irradiation time to estimate quantitative dose-response relationship on the biological response to radiation. In this study, we measured micronucleus formation and (3H) thymidine uptake in U2OS, human osteosarcoma cell line, as indicators of biological response to gamma radiation. Cells were exposed to gamma ray in irradiation room bearing 50,000 Ci 60Co. After irradiation, they were cultured for 24h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and propidium iodide. The number of binuclear cells bearing a micronucleus was counted under a florescence microscope. For proliferation inhibition, cells were cultured for 48 h after the irradiation and (3h) thymidine was pulsed for 4h before harvesting. We statistically analyzed the data for quantitative evaluation of radiation risk at low dose/dose-rate. (Author)

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)

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.

Dose reconstruction modeling for medical radiation workers

International Nuclear Information System (INIS)

Choi, Yeong Chull; Cha, Eun Shil; Lee, Won Jin

2017-01-01

Exposure information is a crucial element for the assessment of health risk due to radiation. Radiation doses received by medical radiation workers have been collected and maintained by public registry since 1996. Since exposure levels in the remote past are greater concern, it is essential to reconstruct unmeasured doses in the past using known information. We developed retrodiction models for different groups of medical radiation workers and estimate individual past doses before 1996. Reconstruction models for past radiation doses received by medical radiation workers were developed, and the past doses were estimated. Using these estimates, organ doses should be calculated which, in turn, will be used to explore a wide range of health risks of medical occupational radiation exposure. Reconstruction models for past radiation doses received by medical radiation workers were developed, and the past doses were estimated. Using these estimates, organ doses should be calculated which, in turn, will be used to explore a wide range of health risks of medical occupational radiation exposure.

Dose reconstruction modeling for medical radiation workers

Energy Technology Data Exchange (ETDEWEB)

Choi, Yeong Chull; Cha, Eun Shil; Lee, Won Jin [Dept. of Preventive Medicine, Korea University, Seoul (Korea, Republic of)

2017-04-15

Exposure information is a crucial element for the assessment of health risk due to radiation. Radiation doses received by medical radiation workers have been collected and maintained by public registry since 1996. Since exposure levels in the remote past are greater concern, it is essential to reconstruct unmeasured doses in the past using known information. We developed retrodiction models for different groups of medical radiation workers and estimate individual past doses before 1996. Reconstruction models for past radiation doses received by medical radiation workers were developed, and the past doses were estimated. Using these estimates, organ doses should be calculated which, in turn, will be used to explore a wide range of health risks of medical occupational radiation exposure. Reconstruction models for past radiation doses received by medical radiation workers were developed, and the past doses were estimated. Using these estimates, organ doses should be calculated which, in turn, will be used to explore a wide range of health risks of medical occupational radiation exposure.

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

Radiation induced muscositis as space flight risk. Model studies on X-ray and heavy ion irradiated typical oral mucosa models

International Nuclear Information System (INIS)

Tschachojan, Viktoria

2014-01-01

Humans in exomagnetospheric space are exposed to highly energetic heavy ion radiation which can be hardly shielded. Since radiation-induced mucositis constitutes a severe complication of heavy ion radiotherapy, it would also implicate a serious medical safety risk for the crew members during prolonged space flights such as missions to Moon or Mars. For assessment of risk developing radiation-induced mucositis, three-dimensional organotypic cultures of immortalized human keratinocytes and fibroblasts were irradiated with a 12 C particle beam at high energies or X-Rays. Immunofluorescence stainings were done from cryosections and radiation induced release of cytokines and chemokines was quantified by ELISA from culture supernatants. The major focuses of this study were on 4, 8, 24 and 48 hours after irradiation. The conducted analyses of our mucosa model showed many structural similarities with the native oral mucosa and authentic immunological responses to radiation exposure. Quantification of the DNA damage in irradiated mucosa models revealed about twice as many DSB after heavy-ion irradiation compared to X-rays at definite doses and time points, suggesting a higher gene toxicity of heavy ions. Nuclear factor κB activation was observed after treatment with X-rays or 12 C particles. An activation of NF κB p65 in irradiated samples could not be detected. ELISA analyses showed significantly higher interleukin 6 and interleukin 8 levels after irradiation with X-rays and 12 C particles compared to non-irradiated controls. However, only X-rays induced significantly higher levels of interleukin 1β. Analyses of TNF-α and IFN-γ showed no radiation-induced effects. Further analyses revealed a radiation-induced reduction in proliferation and loss of compactness in irradiated oral mucosa model, which would lead to local lesions in vivo. In this study we revealed that several pro-inflammatory markers and structural changes are induced by X-rays and heavy-ion irradiation

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)

Monte Carlo mixture model of lifetime cancer incidence risk from radiation exposure on shuttle and international space station

International Nuclear Information System (INIS)

Peterson, L.E.; Cucinotta, F.A.

1999-01-01

Estimating uncertainty in lifetime cancer risk for human exposure to space radiation is a unique challenge. Conventional risk assessment with low-linear-energy-transfer (LET)-based risk from Japanese atomic bomb survivor studies may be inappropriate for relativistic protons and nuclei in space due to track structure effects. This paper develops a Monte Carlo mixture model (MCMM) for transferring additive, National Institutes of Health multiplicative, and multiplicative excess cancer incidence risks based on Japanese atomic bomb survivor data to determine excess incidence risk for various US astronaut exposure profiles. The MCMM serves as an anchor point for future risk projection methods involving biophysical models of DNA damage from space radiation. Lifetime incidence risks of radiation-induced cancer for the MCMM based on low-LET Japanese data for nonleukemia (all cancers except leukemia) were 2.77 (90% confidence limit, 0.75-11.34) for males exposed to 1 Sv at age 45 and 2.20 (90% confidence limit, 0.59-10.12) for males exposed at age 55. For females, mixture model risks for nonleukemia exposed separately to 1 Sv at ages of 45 and 55 were 2.98 (90% confidence limit, 0.90-11.70) and 2.44 (90% confidence limit, 0.70-10.30), respectively. Risks for high-LET 200 MeV protons (LET=0.45 keV/μm), 1 MeV α-particles (LET=100 keV/μm), and 600 MeV iron particles (LET=180 keV/μm) were scored on a per particle basis by determining the particle fluence required for an average of one particle per cell nucleus of area 100 μm 2 . Lifetime risk per proton was 2.68x10 -2 % (90% confidence limit, 0.79x10 -3 %-0.514x10 -2 %). For α-particles, lifetime risk was 14.2% (90% confidence limit, 2.5%-31.2%). Conversely, lifetime risk per iron particle was 23.7% (90% confidence limit, 4.5%-53.0%). Uncertainty in the DDREF for high-LET particles may be less than that for low-LET radiation because typically there is very little dose-rate dependence. Probability density functions for

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)

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)

Mental models of radiation

International Nuclear Information System (INIS)

Saito, Kiyoko

2005-01-01

Laymen and experts participated in interviews designed to reveal their 'mental models' of the processes potentially causing the miscommunications between experts and the public. We analyzed their responses in terms of an 'expert model' circumscribing scientifically relevant information. From results, there are gaps even between experts. Experts on internal exposure focused mainly on artificial radiation and high level of radiation. Experts on radiation biology focused on medical radiation, level of risk, environmental radiation, and hot springs. Experts on dosimetric performance focused on atomic power generation and needs of radiological protection. It means that even experts, they have interests only on their own specialized field. (author)

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

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

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

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.

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.;

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)

Mutiple simultaneous event model for radiation carcinogenesis

International Nuclear Information System (INIS)

Baum, J.W.

1979-01-01

Theoretical Radiobiology and Risk Estimates includes reports on: Multiple Simultaneous Event Model for Radiation Carcinogenesis; Cancer Risk Estimates and Neutron RBE Based on Human Exposures; A Rationale for Nonlinear Dose Response Functions of Power Greater or Less Than One; and Rationale for One Double Event in Model for Radiation Carcinogenesis

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

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)

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

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

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

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)

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.

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.

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

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

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.

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)

Radiation risk index for pediatric CT. A patient-derived metric

International Nuclear Information System (INIS)

Samei, Ehsan; Tian, Xiaoyu; Paul Segars, W.; Frush, Donald P.

2017-01-01

There is a benefit in characterizing radiation-induced cancer risk in pediatric chest and abdominopelvic CT: a singular metric that represents the whole-body radiation burden while also accounting for age, gender and organ sensitivity. To compute an index of radiation risk for pediatric chest and abdominopelvic CT. Using a protocol approved by our institutional review board, 42 pediatric patients (age: 0-16 years, weight: 2-80 kg) were modeled into virtual whole-body anatomical models. Organ doses were estimated for clinical chest and abdominopelvic CT examinations of the patients using validated Monte Carlo simulations of two major scanner models. Using age-, size- and gender-specific organ risk coefficients, the values were converted to normalized effective dose (by dose length product) (denoted as the k factor) and a normalized risk index (denoted as the q factor). An analysis was performed to determine how these factors are correlated with patient age and size for both males and females to provide a strategy to better characterize individualized risk. The k factor was found to be exponentially correlated with the average patient diameter. For both genders, the q factor also exhibited an exponential relationship with both the average patient diameter and with patient age. For both factors, the differences between the scanner models were less than 8%. The study defines a whole-body radiation risk index for chest and abdominopelvic CT imaging, that incorporates individual estimated organ dose values, organ radiation sensitivity, patient size, exposure age and patient gender. This indexing metrology enables the assessment and potential improvement of chest and abdominopelvic CT performance through surveillance of practice dose profiles across patients and may afford improved informed communication. (orig.)

Radiation risk index for pediatric CT. A patient-derived metric

Energy Technology Data Exchange (ETDEWEB)

Samei, Ehsan [Duke University Medical Center, Department of Radiology, Carl E. Ravin Advanced Imaging Laboratories, Durham, NC (United States); Duke University Medical Center, Department of Biomedical Engineering, Electrical and Computer Engineering, Durham, NC (United States); Duke University Medical Center, Medical Physics Graduate Program, Durham, NC (United States); Tian, Xiaoyu [Duke University Medical Center, Department of Radiology, Carl E. Ravin Advanced Imaging Laboratories, Durham, NC (United States); Paul Segars, W. [Duke University Medical Center, Department of Radiology, Carl E. Ravin Advanced Imaging Laboratories, Durham, NC (United States); Duke University Medical Center, Medical Physics Graduate Program, Durham, NC (United States); Frush, Donald P. [Duke University Medical Center, Medical Physics Graduate Program, Durham, NC (United States); Duke University Medical Center, Division of Pediatric Radiology, Department of Radiology, Durham, NC (United States)

2017-12-15

There is a benefit in characterizing radiation-induced cancer risk in pediatric chest and abdominopelvic CT: a singular metric that represents the whole-body radiation burden while also accounting for age, gender and organ sensitivity. To compute an index of radiation risk for pediatric chest and abdominopelvic CT. Using a protocol approved by our institutional review board, 42 pediatric patients (age: 0-16 years, weight: 2-80 kg) were modeled into virtual whole-body anatomical models. Organ doses were estimated for clinical chest and abdominopelvic CT examinations of the patients using validated Monte Carlo simulations of two major scanner models. Using age-, size- and gender-specific organ risk coefficients, the values were converted to normalized effective dose (by dose length product) (denoted as the k factor) and a normalized risk index (denoted as the q factor). An analysis was performed to determine how these factors are correlated with patient age and size for both males and females to provide a strategy to better characterize individualized risk. The k factor was found to be exponentially correlated with the average patient diameter. For both genders, the q factor also exhibited an exponential relationship with both the average patient diameter and with patient age. For both factors, the differences between the scanner models were less than 8%. The study defines a whole-body radiation risk index for chest and abdominopelvic CT imaging, that incorporates individual estimated organ dose values, organ radiation sensitivity, patient size, exposure age and patient gender. This indexing metrology enables the assessment and potential improvement of chest and abdominopelvic CT performance through surveillance of practice dose profiles across patients and may afford improved informed communication. (orig.)

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

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

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)

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

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

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.)

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

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.

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.)

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

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

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

Fire simulation in radioactive waste disposal and the radiation risk associated

International Nuclear Information System (INIS)

Domingos, Érica Nascimento

2018-01-01

An atmospheric dispersion of radioactive material is one of the possible consequences of an accident scenario in nuclear installations, radiative and radioactive waste deposit. Taking into account a possibility of this release of radioactive material into the atmosphere this work proposes a modeling of the atmospheric dispersion from a fire scenario in a deposit of radioactive waste of low and middle level of radiation varying the amount of inventory released in the fire. For this simulation was adopted the software of physical codes of medical health, the HotSpot Health Physics Codes which uses the Gaussian model to calculate an atmospheric dispersion based on the Pasquill atmospheric stability classes. This software calculates a total effective dose in relation to distance, such as a compromised dose in a list of specific organs, among them the lung, object of work study for calculating the risk of cancer associated with a low dose of radiation. The radiological risk calculation is held by the BEIR V model, Biological Effects of Ionizing Radiations, one of the models to estimate the relative risk of cancer induced by ionizing radiation. (author)

Risks of low-level radiation - the evidence of epidemiology

International Nuclear Information System (INIS)

Gloag, D.

1980-01-01

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

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

A simple model for discounting radiation health effects risks with time

International Nuclear Information System (INIS)

Sandquist, G.M.; Rogers, V.C.

1988-01-01

In estimating human health effects resulting from ionizing radiation exposures, it is often assumed that the age of the person at the time of exposure and the latency period for the appearance of any associated health effects are values that maximize the consequences of the exposure. Such assumptions are obviously conservative, but they can result in distortions and errors when nondiscounted radiation-related health effects arising from nonradiation-related risks. Human life expectancy obviously decreases with age, and the latency period for radiation-related health effects can range from a few years to several decades. For example, if a man is 45 yr old at the time of exposure and this exposure results in a lethal health effect 20 yr after exposure, then the expected number of years of life loss is ∼5 yr and not 70 yr, as is commonly assumed in radiation risk assessment studies. If one full-health effect is equivalent to 70 person-yr, then this example exposure results in only 0.07 full-health effects

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.)

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)

Acute Radiation Risk and BRYNTRN Organ Dose Projection Graphical User Interface

Science.gov (United States)

Cucinotta, Francis A.; Hu, Shaowen; Nounu, Hateni N.; Kim, Myung-Hee

2011-01-01

The integration of human space applications risk projection models of organ dose and acute radiation risk has been a key problem. NASA has developed an organ dose projection model using the BRYNTRN with SUM DOSE computer codes, and a probabilistic model of Acute Radiation Risk (ARR). The codes BRYNTRN and SUM DOSE are a Baryon transport code and an output data processing code, respectively. The risk projection models of organ doses and ARR take the output from BRYNTRN as an input to their calculations. With a graphical user interface (GUI) to handle input and output for BRYNTRN, the response models can be connected easily and correctly to BRYNTRN. A GUI for the ARR and BRYNTRN Organ Dose (ARRBOD) projection code provides seamless integration of input and output manipulations, which are required for operations of the ARRBOD modules. The ARRBOD GUI is intended for mission planners, radiation shield designers, space operations in the mission operations directorate (MOD), and space biophysics researchers. BRYNTRN code operation requires extensive input preparation. Only a graphical user interface (GUI) can handle input and output for BRYNTRN to the response models easily and correctly. The purpose of the GUI development for ARRBOD is to provide seamless integration of input and output manipulations for the operations of projection modules (BRYNTRN, SLMDOSE, and the ARR probabilistic response model) in assessing the acute risk and the organ doses of significant Solar Particle Events (SPEs). The assessment of astronauts radiation risk from SPE is in support of mission design and operational planning to manage radiation risks in future space missions. The ARRBOD GUI can identify the proper shielding solutions using the gender-specific organ dose assessments in order to avoid ARR symptoms, and to stay within the current NASA short-term dose limits. The quantified evaluation of ARR severities based on any given shielding configuration and a specified EVA or other mission

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)

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)

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

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

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)

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.

A new approach to reduce uncertainties in space radiation cancer risk predictions.

Directory of Open Access Journals (Sweden)

Francis A Cucinotta

Full Text Available The prediction of space radiation induced cancer risk carries large uncertainties with two of the largest uncertainties being radiation quality and dose-rate effects. In risk models the ratio of the quality factor (QF to the dose and dose-rate reduction effectiveness factor (DDREF parameter is used to scale organ doses for cosmic ray proton and high charge and energy (HZE particles to a hazard rate for γ-rays derived from human epidemiology data. In previous work, particle track structure concepts were used to formulate a space radiation QF function that is dependent on particle charge number Z, and kinetic energy per atomic mass unit, E. QF uncertainties where represented by subjective probability distribution functions (PDF for the three QF parameters that described its maximum value and shape parameters for Z and E dependences. Here I report on an analysis of a maximum QF parameter and its uncertainty using mouse tumor induction data. Because experimental data for risks at low doses of γ-rays are highly uncertain which impacts estimates of maximum values of relative biological effectiveness (RBEmax, I developed an alternate QF model, denoted QFγAcute where QFs are defined relative to higher acute γ-ray doses (0.5 to 3 Gy. The alternate model reduces the dependence of risk projections on the DDREF, however a DDREF is still needed for risk estimates for high-energy protons and other primary or secondary sparsely ionizing space radiation components. Risk projections (upper confidence levels (CL for space missions show a reduction of about 40% (CL∼50% using the QFγAcute model compared the QFs based on RBEmax and about 25% (CL∼35% compared to previous estimates. In addition, I discuss how a possible qualitative difference leading to increased tumor lethality for HZE particles compared to low LET radiation and background tumors remains a large uncertainty in risk estimates.

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

Hanford radiation study III: a cohort study of the cancer risks from radiation to workers at Hanford (1944-77 deaths) by the method of regression models in life-tables

International Nuclear Information System (INIS)

Kneale, G.W.; Stewart, A.M.; Mancuso, T.F.

1981-01-01

Results are presented from the study initiated by Mancuso into the health risks from low-level radiation in workers engaged in plutonium manufacture at Hanford Works, Washington State, USA, and attempts to answer criticisms of previous reports by an in-depth study. Previous reports have aroused much controversy because the reported risk per unit radiation dose for cancers of radiosensitive tissues was much greater than the risk generally accepted on the basis of other studies and widely used in setting safety levels for exposure to low-level radiation. The method of regression models in life-tables isolates the effect of radiation after statistically controlling for a wide range of possible interfering factors. Like the risk of lung cancer for uranium miners the dose-response relation showed a significant downward curve at about 10 rem. There may, therefore, be better agreement with other studies, conducted at higher doses, than is widely assumed. The findings on cancer latency (of about 25 years) and the effect of exposure age (increasing age increases the risk) are in general agreement with other studies. An unexplained finding is a significantly higher dose for all workers than for workers who developed cancers in tissues that are supposed to have low sensitivity to cancer induction by radiation. (author)

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)

Comparison of additive (absolute) risk projection models and multiplicative (relative) risk projection models in estimating radiation-induced lifetime cancer risk

International Nuclear Information System (INIS)

Kai, Michiaki; Kusama, Tomoko

1990-01-01

Lifetime cancer risk estimates depend on risk projection models. While the increasing lengths of follow-up observation periods of atomic bomb survivors in Hiroshima and Nagasaki bring about changes in cancer risk estimates, the validity of the two risk projection models, the additive risk projection model (AR) and multiplicative risk projection model (MR), comes into question. This paper compares the lifetime risk or loss of life-expectancy between the two projection models on the basis of BEIR-III report or recently published RERF report. With Japanese cancer statistics the estimates of MR were greater than those of AR, but a reversal of these results was seen when the cancer hazard function for India was used. When we investigated the validity of the two projection models using epidemiological human data and animal data, the results suggested that MR was superior to AR with respect to temporal change, but there was little evidence to support its validity. (author)

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)

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.)

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

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

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.

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 (

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

Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments

Science.gov (United States)

Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B.; Wang, Ya

2016-06-01

Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk.

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)

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)

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.

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)

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.

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)

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.)

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

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.

Validation of elastic cross section models for space radiation applications

Energy Technology Data Exchange (ETDEWEB)

Werneth, C.M., E-mail: charles.m.werneth@nasa.gov [NASA Langley Research Center (United States); Xu, X. [National Institute of Aerospace (United States); Norman, R.B. [NASA Langley Research Center (United States); Ford, W.P. [The University of Tennessee (United States); Maung, K.M. [The University of Southern Mississippi (United States)

2017-02-01

The space radiation field is composed of energetic particles that pose both acute and long-term risks for astronauts in low earth orbit and beyond. In order to estimate radiation risk to crew members, the fluence of particles and biological response to the radiation must be known at tissue sites. Given that the spectral fluence at the boundary of the shielding material is characterized, radiation transport algorithms may be used to find the fluence of particles inside the shield and body, and the radio-biological response is estimated from experiments and models. The fidelity of the radiation spectrum inside the shield and body depends on radiation transport algorithms and the accuracy of the nuclear cross sections. In a recent study, self-consistent nuclear models based on multiple scattering theory that include the option to study relativistic kinematics were developed for the prediction of nuclear cross sections for space radiation applications. The aim of the current work is to use uncertainty quantification to ascertain the validity of the models as compared to a nuclear reaction database and to identify components of the models that can be improved in future efforts.

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)

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)

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

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.

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

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

Lessons learned using different mouse models during space radiation-induced lung tumorigenesis experiments.

Science.gov (United States)

Wang, Jian; Zhang, Xiangming; Wang, Ping; Wang, Xiang; Farris, Alton B; Wang, Ya

2016-06-01

Unlike terrestrial ionizing radiation, space radiation, especially galactic cosmic rays (GCR), contains high energy charged (HZE) particles with high linear energy transfer (LET). Due to a lack of epidemiologic data for high-LET radiation exposure, it is highly uncertain how high the carcinogenesis risk is for astronauts following exposure to space radiation during space missions. Therefore, using mouse models is necessary to evaluate the risk of space radiation-induced tumorigenesis; however, which mouse model is better for these studies remains uncertain. Since lung tumorigenesis is the leading cause of cancer death among both men and women, and low-LET radiation exposure increases human lung carcinogenesis, evaluating space radiation-induced lung tumorigenesis is critical to enable safe Mars missions. Here, by comparing lung tumorigenesis obtained from different mouse strains, as well as miR-21 in lung tissue/tumors and serum, we believe that wild type mice with a low spontaneous tumorigenesis background are ideal for evaluating the risk of space radiation-induced lung tumorigenesis, and circulating miR-21 from such mice model might be used as a biomarker for predicting the risk. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

Consequences of the new atomic bomb survivor dosimetry on radiation risk estimates

International Nuclear Information System (INIS)

Doerschel, B.

1990-01-01

The assessment of radiation risk includes the following steps: a) selection of biological data from epidemiological studies, b) adjustment of biological data to radiation doses, c) time projection of risk beyond the observation period. The life-time risk used by the ICRP since 1977 is mainly based on the epidemiological data for the survivors of Hiroshima and Nagasaki as well as on the linear dose-response and the absolute risk model. A re-evaluation of the life-time risk seems to be useful because since that time the observation period was further growing and better arguments for choosing a time projection model are available. On the other hand the revised dose can cause changes in the shape of the dose-response curves and of the RBE of neutrons. In the present paper the influence of these factors on the life-time risk will be investigated. (author)

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

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.

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

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.

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)

Ionizing radiation and genetic risks

International Nuclear Information System (INIS)

Sankaranarayanan, K.; Wassom, J.S.

2005-01-01

in certain regions of the genome is related to the presence of large segments of repetitive DNA called segmental duplications (also called duplicons or low copy repeats, LCRs) in such regions. The mechanism that is envisaged for the origin of deletions and other rearrangements involves misalignment of region-specific LCRs of homologous chromosomes in meiosis followed by unequal crossing-over (i.e., non-allelic homologous recombination, NAHR). We hypothesize that: (a) in spermatogonial stem cells, NHEJ is probably the principal mechanism underlying the origin of radiation-induced deletions, although SSA and NAHR may also be involved to some extent, especially at low doses; and (b) in irradiated oocytes, NAHR is likely to be the main mechanism for generating deletions. We suggest future research possibilities, including the development of models for identifying regions of the genome that are susceptible to radiation-induced deletions. Such efforts may have particular significance in the context of the estimation of genetic risks of radiation exposure of human females, a problem that is still with us

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

rearrangements in certain regions of the genome is related to the presence of large segments of repetitive DNA called segmental duplications (also called duplicons or low copy repeats, LCRs) in such regions. The mechanism that is envisaged for the origin of deletions and other rearrangements involves misalignment of region-specific LCRs of homologous chromosomes in meiosis followed by unequal crossing-over (i.e., non-allelic homologous recombination, NAHR). We hypothesize that: (a) in spermatogonial stem cells, NHEJ is probably the principal mechanism underlying the origin of radiation-induced deletions, although SSA and NAHR may also be involved to some extent, especially at low doses; and (b) in irradiated oocytes, NAHR is likely to be the main mechanism for generating deletions. We suggest future research possibilities, including the development of models for identifying regions of the genome that are susceptible to radiation-induced deletions. Such efforts may have particular significance in the context of the estimation of genetic risks of radiation exposure of human females, a problem that is still with us.

Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Executive summary

International Nuclear Information System (INIS)

Jacob, P.; Paretzke, H.G.; Roth, P.

2000-01-01

The Association Contract covers a range of research domains that are important to the Radiation Protection Research Action, especially in the areas 'Evaluation of Radiation Risks' and 'Understanding Radiation Mechanisms and Epidemiology'. Three research projects concentrate on radiation dosimetry research and two projects on the modelling of radiation carcinogenesis. The following list gives an overview on the topics and responsible scientific project leaders of the Association Contract: Study of radiation fields and dosimetry at aviation altitudes. Biokinetics and dosimetry of incorporated radionuclides. Dose reconstruction. Biophysical models for the induction of cancer by radiation. Experimental data for the induction of cancer by radiation of different qualities. (orig.)

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)

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)

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)

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

Low dose diagnostic radiation does not increase cancer risk in cancer prone mice

Energy Technology Data Exchange (ETDEWEB)

Boreham, D., E-mail: dboreham@nosm.ca [Northern Ontario School of Medicine, ON (Canada); Phan, N., E-mail: nghiphan13@yahoo.com [Univ. of Ottawa, Ottawa, ON (Canada); Lemon, J., E-mail: lemonja@mcmaster.ca [McMaster Univ., Hamilton, ON (Canada)

2014-07-01

The increased exposure of patients to low dose diagnostic ionizing radiation has created concern that these procedures will result in greater risk of carcinogenesis. However, there is substantial evidence that shows in many cases that low dose exposure has the opposite effect. We have investigated whether CT scans can modify mechanisms associated with carcinogenesis in cancer-prone mice. Cancer was induced in Trp53+/- mice with an acute high dose whole-body 4 Gy γ-radiation exposure. Four weeks following the cancer-inducing dose, weekly whole-body CT scans (10 mGy/scan, 75 kVp X-rays) were given for ten consecutive weeks adding an additional radiation burden of 0.1 Gy. Short-term biological responses and subsequent lifetime cancer risk were investigated. Five days following the last CT scan, there were no detectable differences in the spontaneous levels of DNA damage in blood cells (reticulocytes). In fact, CT scanned mice had significantly lower constitutive levels of oxidative DNA damage and cell death (apoptosis), compared to non-CT scanned mice. This shows that multiple low dose radiation exposures modified the radio response and indicates protective processes were induced in mice. In mice treated with the multiple CT scans following the high cancer-inducing 4 Gy dose, tumour latency was increased, significantly prolonging lifespan. We conclude that repeated CT scans can reduce the cancer risk of a prior high-dose radiation exposure, and delay the progression of specific types of radiation-induced cancers in Trp53+/-mice. This research shows for the first time that low dose exposure long after cancer initiation events alter risk and reduce cancer morbidity. Cancer induction following low doses does not follow a linear non-threshold model of risk and this model should not be used to extrapolate risk to humans following low dose exposure to ionizing radiation. (author)

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.

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

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.

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.)

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.

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)

Projection of radiation-induced cancer risks across time and populations

International Nuclear Information System (INIS)

Muirhead, C.R.

1991-01-01

Various methods can be used to project the risks of radiation-induced cancer estimated in cohort studies beyond the period of follow-up and to other populations. The choice of risk projection model is reviewed based on data from studies such as those of the Japanese atomic bomb survivors and UK ankylosing spondylitis patients given X ray therapy. Risk estimates applicable to a UK population are calculated on the basis of various models, including those developed by the BEIR V Committee. It is emphasised that the continued follow-up of populations such as the Japanese atomic bomb survivors is of great importance in estimating lifetime risks. (author)

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

Modeling the Risk of Secondary Malignancies after Radiotherapy

Directory of Open Access Journals (Sweden)

Uwe Schneider

2011-11-01

Full Text Available In developed countries, more than half of all cancer patients receive radiotherapy at some stage in the management of their disease. However, a radiation-induced secondary malignancy can be the price of success if the primary cancer is cured or at least controlled. Therefore, there is increasing concern regarding radiation-related second cancer risks in long-term radiotherapy survivors and a corresponding need to be able to predict cancer risks at high radiation doses. Of particular interest are second cancer risk estimates for new radiation treatment modalities such as intensity modulated radiotherapy, intensity modulated arc-therapy, proton and heavy ion radiotherapy. The long term risks from such modern radiotherapy treatment techniques have not yet been determined and are unlikely to become apparent for many years, due to the long latency time for solid tumor induction. Most information on the dose-response of radiation-induced cancer is derived from data on the A-bomb survivors who were exposed to γ-rays and neutrons. Since, for radiation protection purposes, the dose span of main interest is between zero and one Gy, the analysis of the A-bomb survivors is usually focused on this range. With increasing cure rates, estimates of cancer risk for doses larger than one Gy are becoming more important for radiotherapy patients. Therefore in this review, emphasis was placed on doses relevant for radiotherapy with respect to radiation induced solid cancer. Simple radiation protection models should be used only with extreme care for risk estimates in radiotherapy, since they are developed exclusively for low dose. When applied to scatter radiation, such models can predict only a fraction of observed second malignancies. Better semi-empirical models include the effect of dose fractionation and represent the dose-response relationships more accurately. The involved uncertainties are still huge for most of the organs and tissues. A major reason for

How safe is safe enough? Radiation risk for a human mission to Mars.

Directory of Open Access Journals (Sweden)

Francis A Cucinotta

Full Text Available Astronauts on a mission to Mars would be exposed for up to 3 years to galactic cosmic rays (GCR--made up of high-energy protons and high charge (Z and energy (E (HZE nuclei. GCR exposure rate increases about three times as spacecraft venture out of Earth orbit into deep space where protection of the Earth's magnetosphere and solid body are lost. NASA's radiation standard limits astronaut exposures to a 3% risk of exposure induced death (REID at the upper 95% confidence interval (CI of the risk estimate. Fatal cancer risk has been considered the dominant risk for GCR, however recent epidemiological analysis of radiation risks for circulatory diseases allow for predictions of REID for circulatory diseases to be included with cancer risk predictions for space missions. Using NASA's models of risks and uncertainties, we predicted that central estimates for radiation induced mortality and morbidity could exceed 5% and 10% with upper 95% CI near 10% and 20%, respectively for a Mars mission. Additional risks to the central nervous system (CNS and qualitative differences in the biological effects of GCR compared to terrestrial radiation may significantly increase these estimates, and will require new knowledge to evaluate.

Secondary Breast Cancer Risk by Radiation Volume in Women With Hodgkin Lymphoma

Energy Technology Data Exchange (ETDEWEB)

Conway, Jessica L. [Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Department of Surgery, University of British Columbia, Vancouver, British Columbia (Canada); Connors, Joseph M. [Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Tyldesley, Scott [Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Department of Surgery, University of British Columbia, Vancouver, British Columbia (Canada); Savage, Kerry J. [Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Campbell, Belinda A. [Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Zheng, Yvonne Y.; Hamm, Jeremy [Department of Cancer Surveillance and Outcomes, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Pickles, Tom, E-mail: TPickles@bccancer.bc.ca [Centre for Lymphoid Cancer, British Columbia Cancer Agency, Vancouver, British Columbia (Canada); Department of Surgery, University of British Columbia, Vancouver, British Columbia (Canada)

2017-01-01

Purpose: To determine whether the risk of secondary breast cancer (SBC) is reduced in women with Hodgkin lymphoma (HL) treated with smaller field radiation therapy (SFRT) versus mantle field radiation therapy (MRT). Methods and Materials: We used the BC Cancer Agency (BCCA) Lymphoid Cancer Database to identify female patients treated for HL between January 1961 and December 2009. Radiation therapy volumes were categorized as MRT or SFRT, which included involved field, involved site, or involved nodal radiation therapy. SBC risk estimates were compared using competing risk analysis and Fine and Gray multivariable model: MRT ± chemotherapy, SFRT ± chemotherapy, or chemotherapy-only. Results: Of 734 eligible patients, 75% of the living patients have been followed up for more than 10 years, SBC has developed in 54, and 15 have died of breast cancer. The 20-year estimated risks (competing risk cumulative incidence) for SBC differed significantly: MRT 7.5% (95% confidence interval [CI] 4.4%-11.5%), SFRT 3.1% (95% CI 1.0%-7.7%), and chemotherapy-only 2.2% (95% CI 1.0%-4.8%) (P=.01). Using a Fine and Gray model to control for death and patients lost to follow-up, MRT was associated with a higher risk of SBC (hazard ratio [HR] = 2.9; 95% CI 1.4%-6.0%; P=.004) compared with chemotherapy-only and with SFRT (HR = 3.3; 95% CI 1.3%-8.4%; P=.01). SFRT was not associated with a greater risk of SBC compared with chemotherapy-only (HR = 0.87; 95% CI 0.28%-2.66%; P=.80). Conclusion: This study confirms that large-volume MRT is associated with a markedly increased risk of SBC; however, more modern small-volume RT is not associated with a greater risk of SBC than chemotherapy alone.

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

A comparison of radiological risk assessment models: Risk assessment models used by the BEIR V Committee, UNSCEAR, ICRP, and EPA (for NESHAP)

International Nuclear Information System (INIS)

Wahl, L.E.

1994-03-01

Radiological risk assessments and resulting risk estimates have been developed by numerous national and international organizations, including the National Research Council's fifth Committee on the Biological Effects of Ionizing Radiations (BEIR V), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), and the International Commission on Radiological Protection (ICRP). A fourth organization, the Environmental Protection Agency (EPA), has also performed a risk assessment as a basis for the National Emission Standards for Hazardous Air Pollutants (NESHAP). This paper compares the EPA's model of risk assessment with the models used by the BEIR V Committee, UNSCEAR, and ICRP. Comparison is made of the values chosen by each organization for several model parameters: populations used in studies and population transfer coefficients, dose-response curves and dose-rate effects, risk projection methods, and risk estimates. This comparison suggests that the EPA has based its risk assessment on outdated information and that the organization should consider adopting the method used by the BEIR V Committee, UNSCEAR, or ICRP

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)

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

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.

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)

Genomic instability and radiation risk in molecular pathways to colon cancer.

Directory of Open Access Journals (Sweden)

Jan Christian Kaiser

Full Text Available Colon cancer is caused by multiple genomic alterations which lead to genomic instability (GI. GI appears in molecular pathways of microsatellite instability (MSI and chromosomal instability (CIN with clinically observed case shares of about 15-20% and 80-85%. Radiation enhances the colon cancer risk by inducing GI, but little is known about different outcomes for MSI and CIN. Computer-based modelling can facilitate the understanding of the phenomena named above. Comprehensive biological models, which combine the two main molecular pathways to colon cancer, are fitted to incidence data of Japanese a-bomb survivors. The preferred model is selected according to statistical criteria and biological plausibility. Imprints of cell-based processes in the succession from adenoma to carcinoma are identified by the model from age dependences and secular trends of the incidence data. Model parameters show remarkable compliance with mutation rates and growth rates for adenoma, which has been reported over the last fifteen years. Model results suggest that CIN begins during fission of intestinal crypts. Chromosomal aberrations are generated at a markedly elevated rate which favors the accelerated growth of premalignant adenoma. Possibly driven by a trend of Westernization in the Japanese diet, incidence rates for the CIN pathway increased notably in subsequent birth cohorts, whereas rates pertaining to MSI remained constant. An imbalance between number of CIN and MSI cases began to emerge in the 1980s, whereas in previous decades the number of cases was almost equal. The CIN pathway exhibits a strong radio-sensitivity, probably more intensive in men. Among young birth cohorts of both sexes the excess absolute radiation risk related to CIN is larger by an order of magnitude compared to the MSI-related risk. Observance of pathway-specific risks improves the determination of the probability of causation for radiation-induced colon cancer in individual patients

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)

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)

Biophysics Representation of the Two-Hit Model of Alzheimer's Disease for the Exploration of Late CNS Risks from Space Radiation

Science.gov (United States)

Cucinotta, Francis A.; Ponomarev, Artem

2009-01-01

A concern for long-term space travel outside the Earth s magnetic field is the late effects to the central nervous system (CNS) from galactic cosmic ray (GCR) or solar particle events (SPE). Human epidemiology data is severely limited for making CNS risk estimates and it is not clear such effects occur following low LET exposures. We are developing systems biology models based on biological information on specific diseases, and experimental data for proton and heavy ion radiation. A two-hit model of Alzheimer s disease (AD) has been proposed by Zhu et al.(1), which is the framework of our model. Of importance is that over 50% of the US population over the age of 75-y have mild to severe forms of AD. Therefore we recommend that risk assessment for a potential AD risk from space radiation should focus on the projection of an earlier age of onset of AD and the prevention of this possible acceleration through countermeasures. In the two-hit model, oxidative stress and aberrant cell cycle-related abnormalities leading to amyloid-beta plaques and neurofibrillary tangles are necessary and invariant steps in AD. We have formulated a stochastic cell kinetics model of the two-hit AD model. In our model a population of neuronal cells is allowed to undergo renewal through neurogenesis and is susceptible to oxidative stress or cell cycle abnormalities with age-specific accumulation of damage. Baseline rates are fitted to AD population data for specific ages, gender, and for persons with an apolipoprotein 4 allele. We then explore how low LET or heavy ions may increase either of the two-hits or neurogenesis either through persistent oxidative stress, direct mutation, or through changes to the micro-environment, and suggest possible ways to develop accurate quantitative estimates of these processes for predicting AD risks following long-term space travel.

Dose-stochastic radiobiological effect relationship in model of two reactions and estimation of radiation risk

International Nuclear Information System (INIS)

Komochkov, M.M.

1997-01-01

The model of dose-stochastic effect relationship for biological systems capable of self-defence under danger factor effect is developed. A defence system is realized in two forms of organism reaction, which determine innate μ n and adaptive μ a radiosensitivities. The significances of μ n are determined by host (inner) factors; and the significances of μ a , by external factors. The possibilities of adaptive reaction are determined by the coefficient of capabilities of the defence system. The formulas of the dose-effect relationship are the solutions of differential equations of assumed process in the defence system of organism. The model and formulas have been checked both at cell and at human levels. Based on the model and personal monitoring data, the estimation of radiation risk at the Joint Institute for Nuclear Research is done

Radiation-induced mammary carcinogenesis in rodent models. What's different from chemical carcinogenesis?

International Nuclear Information System (INIS)

Imaoka, Tatsuhiko; Nishimura, Mayumi; Iizuka, Daisuke; Daino, Kazuhiro; Takabatake, Takashi; Okamoto, Mieko; Kakinuma, Shizuko; Shimada, Yoshiya

2009-01-01

Ionizing radiation is one of a few well-characterized etiologic factors of human breast cancer. Laboratory rodents serve as useful experimental models for investigating dose responses and mechanisms of cancer development. Using these models, a lot of information has been accumulated about mammary gland cancer, which can be induced by both chemical carcinogens and radiation. In this review, we first list some experimental rodent models of breast cancer induction. We then focus on several topics that are important in understanding the mechanisms and risk modification of breast cancer development, and compare radiation and chemical carcinogenesis models. We will focus on the pathology and natural history of cancer development in these models, genetic changes observed in induced cancers, indirect effects of carcinogens, and finally risk modification by reproductive factors and age at exposure to the carcinogens. In addition, we summarize the knowledge available on mammary stem/progenitor cells as a potential target of carcinogens. Comparison of chemical and radiation carcinogenesis models on these topics indicates certain similarities, but it also indicates clear differences in several important aspects, such as genetic alterations of induced cancers and modification of susceptibility by age and reproductive factors. Identification of the target cell type and relevant translational research for human risk management may be among the important issues that are addressed by radiation carcinogenesis models. (author)

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.

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

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

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

Review of problems and methods for radiation risk assessment in the environment of a nuclear power plant

International Nuclear Information System (INIS)

Grgic, M.

1966-01-01

Radiation impact on the nuclear power plant environment is a very important problem which has to be solved during design and construction. Damage that could be caused by release of radioactive material into the environment should be estimated and the magnitude of nuclear and radiation risk of the power plant should be evaluated. In general the accuracy of estimation is rather poor due to statistical fluctuations of the conditions which influence radioactivity expansion in the environment, especially in the air. Different uncertainties and unresolved problems influence the inaccuracy. Since any real risk should be extremely small compared to potential risk i.e. risk induced by nuclear power plant without any safety measures, even inaccurate estimations are very useful. Method for environmental radiation risk assessment is based on relatively simple models of radiation expansion in the environment and in the air. These models are theoretically solved but they are based on relatively limited number of experimental data. Assessment of the radiation effects on the population health and mortality is an important problem [sl

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

Development of Graphical User Interface for ARRBOD (Acute Radiation Risk and BRYNTRN Organ Dose Projection)

Science.gov (United States)

Kim, Myung-Hee; Hu, Shaowen; Nounu, Hatem N.; Cucinotta, Francis A.

2010-01-01

The space radiation environment, particularly solar particle events (SPEs), poses the risk of acute radiation sickness (ARS) to humans; and organ doses from SPE exposure may reach critical levels during extra vehicular activities (EVAs) or within lightly shielded spacecraft. NASA has developed an organ dose projection model using the BRYNTRN with SUMDOSE computer codes, and a probabilistic model of Acute Radiation Risk (ARR). The codes BRYNTRN and SUMDOSE, written in FORTRAN, are a Baryon transport code and an output data processing code, respectively. The ARR code is written in C. The risk projection models of organ doses and ARR take the output from BRYNTRN as an input to their calculations. BRYNTRN code operation requires extensive input preparation. With a graphical user interface (GUI) to handle input and output for BRYNTRN, the response models can be connected easily and correctly to BRYNTRN in friendly way. A GUI for the Acute Radiation Risk and BRYNTRN Organ Dose (ARRBOD) projection code provides seamless integration of input and output manipulations, which are required for operations of the ARRBOD modules: BRYNTRN, SUMDOSE, and the ARR probabilistic response model. The ARRBOD GUI is intended for mission planners, radiation shield designers, space operations in the mission operations directorate (MOD), and space biophysics researchers. The ARRBOD GUI will serve as a proof-of-concept example for future integration of other human space applications risk projection models. The current version of the ARRBOD GUI is a new self-contained product and will have follow-on versions, as options are added: 1) human geometries of MAX/FAX in addition to CAM/CAF; 2) shielding distributions for spacecraft, Mars surface and atmosphere; 3) various space environmental and biophysical models; and 4) other response models to be connected to the BRYNTRN. The major components of the overall system, the subsystem interconnections, and external interfaces are described in this

Estimated risk for secondary cancer in the contra-lateral breast following radiation therapy of breast cancer

International Nuclear Information System (INIS)

Johansen, Safora; Danielsen, Turi; Olsen, Dag Rune

2008-01-01

Purpose. To facilitate a discussion about the impact of dose heterogeneity on the risk for secondary contralateral breast (CB) cancer predicted with linear and non linear models associated with primary breast irradiation. Methods and materials. Dose volume statistics of the CB calculated for eight patients using a collapsed cone algorithm were used to predict the excess relative risk (ERR) for cancer induction in CB. Both linear and non-linear models were employed. A sensitivity analysis demonstrating the impact of different parameter values on calculated ERR for the eight patients was also included in this study. Results. A proportionality assumption was established to make the calculations with a linear and non-linear model comparable. ERR of secondary cancer predicted by the linear model varied considerably between the patients, while the predicted ERR for the same patients using the non-linear model showed very small variation. The predicted ERRs by the two models were indistinguishable for small doses, i.e. below ∼3 Gy. The sensitivity analysis showed that the quadratic component of the radiation-induction pre-malignant cell term is negligible for lower dose level. The ERR is highly sensitive to the value of agr1 and agr2. Conclusions. Optimization of breast cancer radiation therapy, where also the risk for radiation induced secondary malignancies in the contralateral breast is taken into account, requires robust and valid risk assessment. The linear dose-risk model does not account for the complexity in the mechanisms underlying the development of secondary malignancies following exposure to radiation; this is particularly important when estimating risk associated with highly heterogeneous dose distributions as is the case in the contralateral breast of women receiving breast cancer irradiation

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

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)

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

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.)

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.)

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.

Biophysical models in radiation oncology

International Nuclear Information System (INIS)

Cohen, L.

1984-01-01

The paper examines and describes dose-time relationships in clinical radiation oncology. Realistic models and parameters for specific tissues, organs, and tumor types are discussed in order to solve difficult problems which arise in radiation oncology. The computer programs presented were written to: derive parameters from experimental and clinical data; plot normal- and tumor-cell survival curves; generate iso-effect tables of tumor-curative doses; identify alternative, equally effective procedures for fraction numbers and treatment times; determine whether a proposed course of treatment is safe and adequate, and what adjustments are needed should results suggest that the procedure is unsafe or inadequate; combine the physical isodose distribution with computed cellular surviving fractions for the tumor and all normal tissues traversed by the beam, estimating the risks of recurrence or complications at various points in the irradiated volume, and adjusting the treatment plan and fractionation scheme to minimize these risks

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

Environmental Radiation Effects on Mammals A Dynamical Modeling Approach

CERN Document Server

Smirnova, Olga A

2010-01-01

This text is devoted to the theoretical studies of radiation effects on mammals. It uses the framework of developed deterministic mathematical models to investigate the effects of both acute and chronic irradiation in a wide range of doses and dose rates on vital body systems including hematopoiesis, small intestine and humoral immunity, as well as on the development of autoimmune diseases. Thus, these models can contribute to the development of the system and quantitative approaches in radiation biology and ecology. This text is also of practical use. Its modeling studies of the dynamics of granulocytopoiesis and thrombocytopoiesis in humans testify to the efficiency of employment of the developed models in the investigation and prediction of radiation effects on these hematopoietic lines. These models, as well as the properly identified models of other vital body systems, could provide a better understanding of the radiation risks to health. The modeling predictions will enable the implementation of more ef...

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

Overview of Graphical User Interface for ARRBOD (Acute Radiation Risk and BRYNTRN Organ Dose Projection)

Science.gov (United States)

Kim, Myung-Hee Y.; Hu, Shaowen; Nounu, Hatem N.; Cucinotta, Francis A.

2010-01-01

Solar particle events (SPEs) pose the risk of acute radiation sickness (ARS) to astronauts, because organ doses from large SPEs may reach critical levels during extra vehicular activities (EVAs) or lightly shielded spacecraft. NASA has developed an organ dose projection model of Baryon transport code (BRYNTRN) with an output data processing module of SUMDOSE, and a probabilistic model of acute radiation risk (ARR). BRYNTRN code operation requires extensive input preparation, and the risk projection models of organ doses and ARR take the output from BRYNTRN as an input to their calculations. With a graphical user interface (GUI) to handle input and output for BRYNTRN, these response models can be connected easily and correctly to BRYNTRN in a user friendly way. The GUI for the Acute Radiation Risk and BRYNTRN Organ Dose (ARRBOD) projection code provides seamless integration of input and output manipulations required for operations of the ARRBOD modules: BRYNTRN, SUMDOSE, and the ARR probabilistic response model. The ARRBOD GUI is intended for mission planners, radiation shield designers, space operations in the mission operations directorate (MOD), and space biophysics researchers. Assessment of astronauts organ doses and ARS from the exposure to historically large SPEs is in support of mission design and operation planning to avoid ARS and stay within the current NASA short-term dose limits. The ARRBOD GUI will serve as a proof-of-concept for future integration of other risk projection models for human space applications. We present an overview of the ARRBOD GUI product, which is a new self-contained product, for the major components of the overall system, subsystem interconnections, and external interfaces.

Mechanistic models for cancer development after short time radiation exposure

International Nuclear Information System (INIS)

Kottbauer, M. M.

1997-12-01

In this work two biological based models were developed. First the single-hit model for solid tumors (SHM-S) and second the single-hit model for leukemia (SHM-L). These models are a further development of the Armitage-Doll model for the special case of a short time radiation exposure. The basis of the models is the multistage process of carcinogeneses. The single-hit models provide simultaneously the age-dependent cancer-rate of spontaneous and radiation induced tumors as well as the dose-effect relationships at any age after exposure. The SHM-S leads to a biological based dose-effect relationship, which is similar to the relative risk model suggested by the ICRP 60. The SHM-S describes the increased mortality rate of the bomb survivors more accurate than the relative risk model. The SHM-L results in an additive dose-effect relationship. It is shown that only small differences in the derivation of the two models lead to the two dose-effect relationships. Beside the radiation exposure the new models consider the decrease of the cancer mortality rate at higher ages (age>75) which can be traced back mainly to three causes: competitive causes of death, reduction of cell proliferation and reduction of risk groups. The single-hit models also consider children cancer, the different rates of incidence and mortality, influence of the immune system and the cell-killing effect. (author)

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.

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

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.

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

Dose-response relationships and risk estimates for the induction of cancer due to low doses of low-LET radiation

International Nuclear Information System (INIS)

Elaguppillai, V.

1981-01-01

Risk estimates for radiation-induced cancer at low doses can be obtained only by extrapolation from the known effects at high doses and high dose rates, using a suitable dose-response model. The applicability of three different models, linear, sublinear and supralinear, are discussed in this paper. Several experimental studies tend to favour a sublinear dose-response model (linear-quadratic model) for low-LET radiation. However, human epidemiological studies do not exclude any of the dose-response relationships. The risk estimates based on linear and linear quadratic dose-response models are compared and it is concluded that, for low-LET radiation, the linear dose-response model would probably over-estimate the actual risk of cancer by a factor of two or more. (author)

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)

Risk estimation and decision making: the health effects on populations of exposure to low levels of ionizing radiation

International Nuclear Information System (INIS)

Fabrikant, J.I.

1982-01-01

Presented is a background for an understanding of the potential health effects in populations exposed to low-level radiation. Discussed is the knowledge about the health effects of low-level radiation. Comments on how the risks of radiation-induced cancer and genetically-related ill-health in man may be estimated, the sources of the scientific and epidemiological data, the dose-response models used, and the uncertainties which limit precise estimates of excess risks from radiation. Also discussed are the implications of numerical risk estimation for radiation protection and decision-making for public health policy

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

A method for determining weights for excess relative risk and excess absolute risk when applied in the calculation of lifetime risk of cancer from radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Walsh, Linda [Federal Office for Radiation Protection, Department of Radiation Protection and Health, Oberschleissheim (Germany); University of Manchester, The Faculty of Medical and Human Sciences, Manchester (United Kingdom); Schneider, Uwe [University of Zurich, Vetsuisse Faculty, Zurich (Switzerland); Radiotherapy Hirslanden AG, Aarau (Switzerland)

2013-03-15

Radiation-related risks of cancer can be transported from one population to another population at risk, for the purpose of calculating lifetime risks from radiation exposure. Transfer via excess relative risks (ERR) or excess absolute risks (EAR) or a mixture of both (i.e., from the life span study (LSS) of Japanese atomic bomb survivors) has been done in the past based on qualitative weighting. Consequently, the values of the weights applied and the method of application of the weights (i.e., as additive or geometric weighted means) have varied both between reports produced at different times by the same regulatory body and also between reports produced at similar times by different regulatory bodies. Since the gender and age patterns are often markedly different between EAR and ERR models, it is useful to have an evidence-based method for determining the relative goodness of fit of such models to the data. This paper identifies a method, using Akaike model weights, which could aid expert judgment and be applied to help to achieve consistency of approach and quantitative evidence-based results in future health risk assessments. The results of applying this method to recent LSS cancer incidence models are that the relative EAR weighting by cancer solid cancer site, on a scale of 0-1, is zero for breast and colon, 0.02 for all solid, 0.03 for lung, 0.08 for liver, 0.15 for thyroid, 0.18 for bladder and 0.93 for stomach. The EAR weighting for female breast cancer increases from 0 to 0.3, if a generally observed change in the trend between female age-specific breast cancer incidence rates and attained age, associated with menopause, is accounted for in the EAR model. Application of this method to preferred models from a study of multi-model inference from many models fitted to the LSS leukemia mortality data, results in an EAR weighting of 0. From these results it can be seen that lifetime risk transfer is most highly weighted by EAR only for stomach cancer. However

Sensitivity of APSIM/ORYZA model due to estimation errors in solar radiation

OpenAIRE

Alexandre Bryan Heinemann; Pepijn A.J. van Oort; Diogo Simões Fernandes; Aline de Holanda Nunes Maia

2012-01-01

Crop models are ideally suited to quantify existing climatic risks. However, they require historic climate data as input. While daily temperature and rainfall data are often available, the lack of observed solar radiation (Rs) data severely limits site-specific crop modelling. The objective of this study was to estimate Rs based on air temperature solar radiation models and to quantify the propagation of errors in simulated radiation on several APSIM/ORYZA crop model seasonal outputs, yield, ...

Lower radiation weighting factor for radon indicated in mechanistic modelling of human lung cancer

International Nuclear Information System (INIS)

Brugmans, M.J.P.; Leenhouts, H.P.

2002-01-01

A two-mutation carcinogenesis (TMC) model was fitted to the age-dependent lung cancer incidence in a cohort of Dutch Hodgkin patients treated with radiotherapy. Employing the results of previous TMC analyses of lung cancer due to smoking (by British doctors) and due to exposure to radon (for Colorado miners) a model fit was obtained with an estimate for the low LET radiation effect at the cellular level. This allows risk calculations for lung cancer from low LET radiation. The excess absolute risks are in tune with the values reported in the literature, the excess relative risks differ among the exposed groups. Comparing the cellular radiation coefficients for radon and for low LET radiation leads to an estimated radiation weighting factor for radon of 3 (0.1-6). (author)

Modelling of radiation risk induced by radon and sources of Auger electrons

International Nuclear Information System (INIS)

Boem, R.

2003-01-01

This thesis follows the national and worldwide radon research and application Auger radionuclides in nuclear medicine. Results of this thesis can be summarised into several points: (1) For the prediction of cancer risk following the exposure, it is also necessary to consider the mean cycle time of target cells. From our analyses it can be concluded that the mean cycle time of target cells should exceed 100 days. (2) The value of excess relative risk is for smokers ERR/WLM = (2.4-4.1)x10 -3 WLM -1 and that of the nonsmokers ERR/WLM=(4.2-10.7)x10 -3 WLM -1 , considering the underground medium. Excess relative risk for the nonsmokers ERR/(Bq m -3 ) = (1.0-3.5) Bq -1 m 3 and for smokers ERR/(Bq m -3 ) = (0.3-1.2) 10 -3 Bq -1 m 3 is supposed in dwellings. (3) Microdosimetric models are very helpful and suitable for prediction of the radon risk for underground conditions, as well as for indoor radon risk evaluation and they are also able to take into account the influence of the smoking habit. (4) The spatial distribution of energy deposition events and their magnitude is an essential input to evaluate the effects of radiation on biological systems. Therefore, for the calculation of deposited energy from the DNA incorporated Auger emitters, it is necessary at the DNA level to employ the MC calculation. In an effort to save computer time and memory it is possible to use the fitted function for monoenergetic electrons for estimation of at least relative radiotoxicity. The value of energy deposited in a small volume (sphere of diameter 2 nm) can be considered as the first estimation of an Auger emitter's radiotoxicity. (author)

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

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

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

Modeling of the Martian environment for radiation analysis

International Nuclear Information System (INIS)

De Angelis, G.; Wilson, J.W.; Clowdsley, M.S.; Qualls, G.D.; Singleterry, R.C.

2006-01-01

A model for the radiation environment to be found on the planet Mars due to Galactic Cosmic Rays (GCR) has been developed. Solar modulated primary particles rescaled for conditions at Mars are transported through the Martian atmosphere down to the surface, with altitude and backscattering patterns taken into account. The altitude to compute the atmospheric thickness profile has been determined by using a model for the topography based on the data provided by the Mars Orbiter Laser Altimeter (MOLA) instrument on board the Mars Global Surveyor (MGS) spacecraft. The Mars surface composition has been modeled based on averages over the measurements obtained from orbiting spacecraft and at various landing sites, taking into account the possible volatile inventory (e.g. CO 2 and H 2 O ices) along with its time variations throughout the Martian year. The Mars Radiation Environment Model has been made available worldwide through the Space Ionizing Radiation Effects and Shielding Tools (SIREST) website, a project of NASA Langley Research Center. This site has been developed to provide the scientific and engineering communities with an interactive site containing a variety of environmental models, shield evaluation codes, and radiation response models to allow a thorough assessment of ionizing radiation risk for current and future space missions

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

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

NASA Models of Space Radiation Induced Cancer, Circulatory Disease, and Central Nervous System Effects

Science.gov (United States)

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

2013-01-01

The risks of late effects from galactic cosmic rays (GCR) and solar particle events (SPE) are potentially a limitation to long-term space travel. The late effects of highest concern have significant lethality including cancer, effects to the central nervous system (CNS), and circulatory diseases (CD). For cancer and CD the use of age and gender specific models with uncertainty assessments based on human epidemiology data for low LET radiation combined with relative biological effectiveness factors (RBEs) and dose- and dose-rate reduction effectiveness factors (DDREF) to extrapolate these results to space radiation exposures is considered the current "state-of-the-art". The revised NASA Space Risk Model (NSRM-2014) is based on recent radio-epidemiology data for cancer and CD, however a key feature of the NSRM-2014 is the formulation of particle fluence and track structure based radiation quality factors for solid cancer and leukemia risk estimates, which are distinct from the ICRP quality factors, and shown to lead to smaller uncertainties in risk estimates. Many persons exposed to radiation on earth as well as astronauts are life-time never-smokers, which is estimated to significantly modify radiation cancer and CD risk estimates. A key feature of the NASA radiation protection model is the classification of radiation workers by smoking history in setting dose limits. Possible qualitative differences between GCR and low LET radiation increase uncertainties and are not included in previous risk estimates. Two important qualitative differences are emerging from research studies. The first is the increased lethality of tumors observed in animal models compared to low LET radiation or background tumors. The second are Non- Targeted Effects (NTE), which include bystander effects and genomic instability, which has been observed in cell and animal models of cancer risks. NTE's could lead to significant changes in RBE and DDREF estimates for GCR particles, and the potential

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

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.)

Pitfalls in Prediction Modeling for Normal Tissue Toxicity in Radiation Therapy: An Illustration With the Individual Radiation Sensitivity and Mammary Carcinoma Risk Factor Investigation Cohorts

Energy Technology Data Exchange (ETDEWEB)

Mbah, Chamberlain, E-mail: chamberlain.mbah@ugent.be [Department of Basic Medical Sciences, Faculty of Health Sciences, Ghent University, Ghent (Belgium); Department of Mathematical Modeling, Statistics, and Bioinformatics, Faculty of Bioscience Engineering, Ghent University, Ghent (Belgium); Thierens, Hubert [Department of Basic Medical Sciences, Faculty of Health Sciences, Ghent University, Ghent (Belgium); Thas, Olivier [Department of Mathematical Modeling, Statistics, and Bioinformatics, Faculty of Bioscience Engineering, Ghent University, Ghent (Belgium); National Institute for Applied Statistics Research Australia, University of Wollongong, Wollongong, New South Wales (Australia); De Neve, Jan [Department of Data Analysis, Faculty of Psychology and Educational Sciences, Ghent University, Ghent (Belgium); Chang-Claude, Jenny; Seibold, Petra; Botma, Akke [Division of Cancer Epidemiology, German Cancer Research Center, Heidelberg (Germany); West, Catharine [Translational Radiobiology Group, Institute of Cancer Sciences, Radiotherapy Related Research, Christie Hospital NHS Trust, University of Manchester, Manchester (United Kingdom); De Ruyck, Kim [Department of Basic Medical Sciences, Faculty of Health Sciences, Ghent University, Ghent (Belgium)

2016-08-01

Purpose: To identify the main causes underlying the failure of prediction models for radiation therapy toxicity to replicate. Methods and Materials: Data were used from two German cohorts, Individual Radiation Sensitivity (ISE) (n=418) and Mammary Carcinoma Risk Factor Investigation (MARIE) (n=409), of breast cancer patients with similar characteristics and radiation therapy treatments. The toxicity endpoint chosen was telangiectasia. The LASSO (least absolute shrinkage and selection operator) logistic regression method was used to build a predictive model for a dichotomized endpoint (Radiation Therapy Oncology Group/European Organization for the Research and Treatment of Cancer score 0, 1, or ≥2). Internal areas under the receiver operating characteristic curve (inAUCs) were calculated by a naïve approach whereby the training data (ISE) were also used for calculating the AUC. Cross-validation was also applied to calculate the AUC within the same cohort, a second type of inAUC. Internal AUCs from cross-validation were calculated within ISE and MARIE separately. Models trained on one dataset (ISE) were applied to a test dataset (MARIE) and AUCs calculated (exAUCs). Results: Internal AUCs from the naïve approach were generally larger than inAUCs from cross-validation owing to overfitting the training data. Internal AUCs from cross-validation were also generally larger than the exAUCs, reflecting heterogeneity in the predictors between cohorts. The best models with largest inAUCs from cross-validation within both cohorts had a number of common predictors: hypertension, normalized total boost, and presence of estrogen receptors. Surprisingly, the effect (coefficient in the prediction model) of hypertension on telangiectasia incidence was positive in ISE and negative in MARIE. Other predictors were also not common between the 2 cohorts, illustrating that overcoming overfitting does not solve the problem of replication failure of prediction models completely

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)

Sensitivity of APSIM/ORYZA model due to estimation errors in solar radiation

Directory of Open Access Journals (Sweden)

Alexandre Bryan Heinemann

2012-01-01

Full Text Available Crop models are ideally suited to quantify existing climatic risks. However, they require historic climate data as input. While daily temperature and rainfall data are often available, the lack of observed solar radiation (Rs data severely limits site-specific crop modelling. The objective of this study was to estimate Rs based on air temperature solar radiation models and to quantify the propagation of errors in simulated radiation on several APSIM/ORYZA crop model seasonal outputs, yield, biomass, leaf area (LAI and total accumulated solar radiation (SRA during the crop cycle. The accuracy of the 5 models for estimated daily solar radiation was similar, and it was not substantially different among sites. For water limited environments (no irrigation, crop model outputs yield, biomass and LAI was not sensitive for the uncertainties in radiation models studied here.

The carcinogenic risks of low-LET and high-LET ionizing radiations

International Nuclear Information System (INIS)

Fabrikant, J.I.

1991-08-01

This report presents a discussion on risk from ionizing radiations to human populations. Important new information on human beings has come mainly from further follow-up of existing epidemiological studies, notably the Japanese atomic bomb survivors and the ankylosing spondylitis patients; from new epidemiological surveys, such as the patients treated for cancer of the uterine cervix; and from combined surveys, including workers exposed in underground mines. Since the numerous and complex differences among the different study populations introduce factors that influence the risk estimates derived in ways that are not completely understood, it is not clear how to combine the different risk estimates obtained. These factors involve complex biological and physical variables distributed over time. Because such carcinogenic effects occur too infrequently to be demonstrated at low doses, the risks of low-dose radiation can be estimated only by interpolation from observations at high doses on the basis of theoretical concepts, mathematical models and available empirical evidence, primarily the epidemiological surveys of large populations exposed to ionizing radiation. In spite of a considerable amount of research, only recently has there has been efforts to apply the extensive laboratory data in animals to define the dose-incidence relationship in the low dose region. There simply are insufficient data in the epidemiological studies of large human populations to estimate risk coefficients directly from exposure to low doses. The risk estimates for the carcinogenic effects of radiation have been, in the past, somewhat low and reassessment of the numerical values is now necessary

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.

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)

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)

[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.

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.

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.

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.

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)

A comparison of models for risk assessment

International Nuclear Information System (INIS)

Kellerer, A.M.; Jing Chen

1993-01-01

Various mathematical models have been used to represent the dependence of excess cancer risk on dose, age and time since exposure. For solid cancers, i.e. all cancers except leukaemia, the so-called relative risk model is usually employed. However, there can be quite different relative risk models. The most usual model for the quantification of excess tumour rate among the atomic bomb survivors has been a dependence of the relative risk on age at exposure, but it has been shown recently that an age attained model can be equally applied, to represent the observations among the atomic bomb survivors. The differences between the models and their implications are explained. It is also shown that the age attained model is similar to the approaches that have been used in the analysis of lung cancer incidence among radon exposed miners. A more unified approach to modelling of radiation risks can thus be achieved. (3 figs.)

Phenomenological modelling of second cancer incidence for radiation treatment planning

International Nuclear Information System (INIS)

Pfaffenberger, Asja; Oelfke, Uwe; Schneider, Uwe; Poppe, Bjoern

2009-01-01

It is still an unanswered question whether a relatively low dose of radiation to a large volume or a higher dose to a small volume produces the higher cancer incidence. This is of interest in view of modalities like IMRT or rotation therapy where high conformity to the target volume is achieved at the cost of a large volume of normal tissue exposed to radiation. Knowledge of the shape of the dose response for radiation-induced cancer is essential to answer the question of what risk of second cancer incidence is implied by which treatment modality. This study therefore models the dose response for radiation-induced second cancer after radiation therapy of which the exact mechanisms are still unknown. A second cancer risk estimation tool for treatment planning is presented which has the potential to be used for comparison of different treatment modalities, and risk is estimated on a voxel basis for different organs in two case studies. The presented phenomenological model summarises the impact of microscopic biological processes into effective parameters of mutation and cell sterilisation. In contrast to other models, the effective radiosensitivities of mutated and non-mutated cells are allowed to differ. Based on the number of mutated cells present after irradiation, the model is then linked to macroscopic incidence by summarising model parameters and modifying factors into natural cancer incidence and the dose response in the lower-dose region. It was found that all principal dose-response functions discussed in the literature can be derived from the model. However, from the investigation and due to scarcity of adequate data, rather vague statements about likelihood of dose-response functions can be made than a definite decision for one response. Based on the predicted model parameters, the linear response can probably be rejected using the dynamics described, but both a flattening response and a decrease appear likely, depending strongly on the effective cell

Modeling human risk: Cell & molecular biology in context

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-06-01

It is anticipated that early in the next century manned missions into outer space will occur, with a mission to Mars scheduled between 2015 and 2020. However, before such missions can be undertaken, a realistic estimation of the potential risks to the flight crews is required. One of the uncertainties remaining in this risk estimation is that posed by the effects of exposure to the radiation environment of outer space. Although the composition of this environment is fairly well understood, the biological effects arising from exposure to it are not. The reasons for this are three-fold: (1) A small but highly significant component of the radiation spectrum in outer space consists of highly charged, high energy (HZE) particles which are not routinely experienced on earth, and for which there are insufficient data on biological effects; (2) Most studies on the biological effects of radiation to date have been high-dose, high dose-rate, whereas in space, with the exception of solar particle events, radiation exposures will be low-dose, low dose-rate; (3) Although it has been established that the virtual absence of gravity in space has a profound effect on human physiology, it is not clear whether these effects will act synergistically with those of radiation exposure. A select panel will evaluate the utilizing experiments and models to accurately predict the risks associated with exposure to HZE particles. Topics of research include cellular and tissue response, health effects associated with radiation damage, model animal systems, and critical markers of Radiation response.

The risks of leukaemia and other cancers in Seascale from radiation exposure

International Nuclear Information System (INIS)

Stather, J.W.; Dionian, J.; Brown, J.; Fell, T.P.; Muirhead, C.R.

1986-04-01

Including new data in the radiation dose calculations for the Seascale study population of 1225 children and young persons, followed to 20 years of age or 1980, has, with modifications to dosimetric models, increased the predicted number of radiation-induced leukaemia resulting from Sallafield discharges from 0.01 to 0.016. Risk to the average child in the study, from the discharges, is now calculated as about 1 in 75,000 with a maximum risk of about 1 in 30,000 for children born in the mid-1950s. For the four fatal leukemias to be attributed to the Sellafield operations, the calculated average risk for all the children would have to be increased about 250 times. Estimate of the overall risk of radiation-induced leukaemia in the study population, from combined sources, has increased by less than 10% of the previous estimate and the total number of cases is still rounded to 0.1, as in R171. Risk to the average child is now calculated as about 1 in 12,250, about two thirds from natural background, 16% from Sellafield discharges, and 9% each from weapons fallout and medical exposure. (U.K.)

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.

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.

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)

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.

Risks associated with low level ionizing radiation (with special reference to nuclear power workers)

International Nuclear Information System (INIS)

1989-01-01

This document describes a project to use epidemiological studies of workers in the nuclear industry to estimate the cancer risk associated with low-dose chronic exposure to ionizing radiation. The project aims both to improve the basis for radiation risk assessment and to test the validity of currently used models for the extrapolation of radiation risk. This report focusses on the former aim, and summarizes discussions at two meetings held in June 1988. One of these was a small working group consisting mainly of epidemiologists who had carried out studies of nuclear workers; the other included nominees of the nuclear industries of eleven countries as well as epidemiologists and radiation physicists and biologists. As a result of the meetings, efforts are underway to pool existing data and a feasibility study is addressing the possibility of an international collaborative study of unstudied groups of nuclear workers

Theoretical epidemiology applied to health physics: estimation of the risk of radiation-induced breast cancer

International Nuclear Information System (INIS)

Sutherland, J.V.

1983-01-01

Indirect estimation of low-dose radiation hazards is possible using the multihit model of carcinogenesis. This model is based on cancer incidence data collected over many decades on tens of millions of people. Available data on human radiation effects can be introduced into the modeling process without the requirement that these data precisely define the model to be used. This reduction in the information demanded from the limited data on human radiation effects allows a more rational approach to estimation of low-dose radiation hazards and helps to focus attention on research directed towards understanding the process of carcinogenesis, rather than on repeating human or animal experiments that cannot provide sufficient data to resolve the low-dose estimation problem. Assessment of the risk of radiation-induced breast cancer provides an excellent example of the utility of multihit modeling procedures

Very High-Risk Localized Prostate Cancer: Outcomes Following Definitive Radiation

International Nuclear Information System (INIS)

Narang, Amol K.; Gergis, Carol; Robertson, Scott P.; He, Pei; Ram, Ashwin N.; McNutt, Todd R.; Griffith, Emily; DeWeese, Theodore A.; Honig, Stephanie; Singh, Harleen; Song, Danny Y.; Tran, Phuoc T.; DeWeese, Theodore L.

2016-01-01

Purpose: Existing definitions of high-risk prostate cancer consist of men who experience significant heterogeneity in outcomes. As such, criteria that identify a subpopulation of National Comprehensive Cancer Network (NCCN) high-risk prostate cancer patients who are at very high risk (VHR) for poor survival outcomes following prostatectomy were recently developed at our institution and include the presence of any of the following disease characteristics: multiple NCCN high-risk factors, primary Gleason pattern 5 disease and/or ≥5 biopsy cores with Gleason sums of 8 to 10. Whether these criteria also apply to men undergoing definitive radiation is unclear, as is the optimal treatment regimen in these patients. Methods and Materials: All men consecutively treated with definitive radiation by a single provider from 1993 to 2006 and who fulfilled criteria for NCCN high-risk disease were identified (n=288), including 99 patients (34%) with VHR disease. Multivariate-adjusted competing risk regression models were constructed to assess associations between the VHR definition and biochemical failure (BF), distant metastasis (DM), and prostate cancer–specific mortality (PCSM). Multivariate-adjusted Cox regression analysis assessed the association of the VHR definition with overall mortality (OM). Cumulative incidences of failure endpoints were compared between VHR men and other NCCN high-risk men. Results: Men with VHR disease compared to other NCCN high-risk men experienced a higher 10-year incidence of BF (54.0% vs 35.4%, respectively, P<.001), DM (34.9% vs 13.4%, respectively, P<.001), PCSM (18.5% vs 5.9%, respectively, P<.001), and OM (36.4% vs 27.0%, respectively, P=.04). VHR men with a detectable prostate-specific antigen (PSA) concentration at the end of radiation (EOR) remained at high risk of 10-year PCSM compared to VHR men with an undetectable EOR PSA (31.0% vs 13.7%, respectively, P=.05). Conclusions: NCCN high-risk prostate cancer patients who meet VHR

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)

Implications of the two stage clonal expansion model to radiation risk estimation

International Nuclear Information System (INIS)

Curtis, S.B.; Hazelton, W.D.; Luebeck, E.G.; Moolgavkar, S.H.

2003-01-01

The Two Stage Clonal Expansion Model of carcinogenesis has been applied to the analysis of several cohorts of persons exposed to chronic exposures of high and low LET radiation. The results of these analyses are: (1) the importance of radiation-induced initiation is small and, if present at all, contributes to cancers only late in life and only if exposure begins early in life, (2) radiation-induced promotion dominates and produces the majority of cancers by accelerating proliferation of already-initiated cells, and (3) radiation-induced malignant conversion is important only during and immediately after exposure ceases and tends to dominate only late in life, acting on already initiated and promoted cells. Two populations, the Colorado Plateau miners (high-LET, radon exposed) and the Canadian radiation workers (low-LET, gamma ray exposed) are used as examples to show the time dependence of the hazard function and the relative importance of the three hypothesized processes (initiation, promotion and malignant conversion) for each radiation quality

Assessment of radiation-induced second cancer risks in proton therapy and IMRT for organs inside the primary radiation field

Science.gov (United States)

Paganetti, Harald; Athar, Basit S.; Moteabbed, Maryam; Adams, Judith A.; Schneider, Uwe; Yock, Torunn I.

2012-10-01

There is clinical evidence that second malignancies in radiation therapy occur mainly within the beam path, i.e. in the medium or high-dose region. The purpose of this study was to assess the risk for developing a radiation-induced tumor within the treated volume and to compare this risk for proton therapy and intensity-modulated photon therapy (IMRT). Instead of using data for specific patients we have created a representative scenario. Fully contoured age- and gender-specific whole body phantoms (4 year and 14 year old) were uploaded into a treatment planning system and tumor volumes were contoured based on patients treated for optic glioma and vertebral body Ewing's sarcoma. Treatment plans for IMRT and proton therapy treatments were generated. Lifetime attributable risks (LARs) for developing a second malignancy were calculated using a risk model considering cell kill, mutation, repopulation, as well as inhomogeneous organ doses. For standard fractionation schemes, the LAR for developing a second malignancy from radiation therapy alone was found to be up to 2.7% for a 4 year old optic glioma patient treated with IMRT considering a soft-tissue carcinoma risk model only. Sarcoma risks were found to be below 1% in all cases. For a 14 year old, risks were found to be about a factor of 2 lower. For Ewing's sarcoma cases the risks based on a sarcoma model were typically higher than the carcinoma risks, i.e. LAR up to 1.3% for soft-tissue sarcoma. In all cases, the risk from proton therapy turned out to be lower by at least a factor of 2 and up to a factor of 10. This is mainly due to lower total energy deposited in the patient when using proton beams. However, the comparison of a three-field and four-field proton plan also shows that the distribution of the dose, i.e. the particular treatment plan, plays a role. When using different fractionation schemes, the estimated risks roughly scale with the total dose difference in%. In conclusion, proton therapy can

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

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)

Perception and acceptance of risk from radiation exposure in space flight

International Nuclear Information System (INIS)

Slovic, P.

1997-01-01

There are a number of factors that influence how a person views a particular risk. These include whether the risk is judged to be voluntary and/or controllable, whether the effects are immediate or delayed, and the magnitude of the benefits that are to be gained as a result of being exposed to the risk. An important aspect of the last factor is whether those who suffer the risks are also those who stand to reap the benefits. The manner in which risk is viewed is also significantly influenced by the manner in which it is framed and presented. In short, risk does not exist in the world independent of our minds and cultures, waiting to be measured. Assessments of risk are based on models whose structure is subjective and associated evaluations are laden with assumptions whose inputs are dependent on judgments. In fact, subjectivity permeates every aspect of risk assessment. The assessment of radiation risks in space is no exception. The structuring of the problem includes judgments related to the probability, magnitude, and effects of the various types of radiation likely to be encountered and assumptions related to the quantitative relationship between dose and a range of specific effects, all of which have associated uncertainties. For these reasons, there is no magic formula that will lead us to a precise level of acceptable risk from exposure to radiation in space. Acceptable risk levels must evolve through a process of negotiation that integrates a large number of social, technical, and economic factors. In the end, a risk that is deemed to be acceptable will be the outgrowth of the weighing of risks and benefits and the selection of the option that appears to be best

Risk Perception and Anxiety Regarding Radiation after the 2011 Fukushima Nuclear Power Plant Accident: A Systematic Qualitative Review

Science.gov (United States)

Lyamzina, Yuliya; Suzuki, Yuriko; Murakami, Michio

2017-01-01

The purpose of this study was to provide a review of the publications of the risk perceptions or anxiety regarding radiation among people living in Japan after the 2011 Fukushima nuclear power plant accident. Two database (MEDLINE and PsycINFO) and hand-searched the references in identified publications were searched. For each identified publication, the measurements and time related-change of risk perception and anxiety regarding radiation were summarized. Twenty-four publications were identified. Quantitative measures of risk perception or anxiety were roughly divided into two types: single-item Likert scales that measure anxiety about radiation; and theoretical, or model-based measures. Rates of Fukushima residents with radiation-related anxiety decreased from 2012 to 2015. Factors governing risk perception or radiation-related anxiety were summarized by demographics, disaster-related stressors, trusted information, and radiation-related variables. The effects of risk perception or anxiety regarding radiation were summarized as severe distress, intention to leave employment or not to return home, or other dimensions. This review provides summary of current findings on risk perception or anxiety regarding radiation in Japan after the accident. Further researches are needed about detailed statistical analysis for time-related change and causality among variables. PMID:29077045

Risk Perception and Anxiety Regarding Radiation after the 2011 Fukushima Nuclear Power Plant Accident: A Systematic Qualitative Review.

Science.gov (United States)

Takebayashi, Yoshitake; Lyamzina, Yuliya; Suzuki, Yuriko; Murakami, Michio

2017-10-27

The purpose of this study was to provide a review of the publications of the risk perceptions or anxiety regarding radiation among people living in Japan after the 2011 Fukushima nuclear power plant accident. Two database (MEDLINE and PsycINFO) and hand-searched the references in identified publications were searched. For each identified publication, the measurements and time related-change of risk perception and anxiety regarding radiation were summarized. Twenty-four publications were identified. Quantitative measures of risk perception or anxiety were roughly divided into two types: single-item Likert scales that measure anxiety about radiation; and theoretical, or model-based measures. Rates of Fukushima residents with radiation-related anxiety decreased from 2012 to 2015. Factors governing risk perception or radiation-related anxiety were summarized by demographics, disaster-related stressors, trusted information, and radiation-related variables. The effects of risk perception or anxiety regarding radiation were summarized as severe distress, intention to leave employment or not to return home, or other dimensions. This review provides summary of current findings on risk perception or anxiety regarding radiation in Japan after the accident. Further researches are needed about detailed statistical analysis for time-related change and causality among variables.

Radiation risk and protection of patients in clinical SPECT/CT

Energy Technology Data Exchange (ETDEWEB)

Brix, Gunnar; Nekolla, Elke A.; Nosske, Dietmar [Federal Office for Radiation Protection, Department of Medical and Occupational Radiation Protection, Oberschleissheim (Germany); Borowski, Markus [Klinikum Braunschweig, Institute of Radiation Diagnostics and Nuclear Medicine, Braunschweig (Germany)

2014-05-15

Clinical studies have demonstrated that hybrid single photon emission computed tomography (SPECT)/CT for various diagnostic issues has an added value as compared to SPECT alone. However, the combined acquisition of functional and anatomical images can substantially increase radiation exposure to patients, in particular when using a hybrid system with diagnostic CT capabilities. It is, therefore, essential to carefully balance the diagnostic needs and radiation protection requirements. To this end, the evidence on health effects induced by ionizing radiation is outlined. In addition, the essential concepts for estimating radiation doses and lifetime attributable cancer risks associated with SPECT/CT examinations are presented taking into account both the new recommendations of the International Commission on Radiological Protection (ICRP) as well as the most recent radiation risk models. Representative values of effective dose and lifetime attributable risk are reported for ten frequently used SPECT radiopharmaceuticals and five fully diagnostic partial-body CT examinations. A diagnostic CT scan acquired as part of a combined SPECT/CT examination contributes considerably to, and for some applications even dominates, the total patient exposure. For the common SPECT and CT examinations considered in this study, the lifetime attributable risk of developing a radiation-related cancer is less than 0.27 %/0.37 % for men/women older than 16 years, respectively, and decreases markedly with increasing age at exposure. Since there is no clinical indication for a SPECT/CT examination unless an emission scan has been indicated, the issue on justification comes down to the question of whether it is necessary to additionally acquire a low-dose CT for attenuation correction and anatomical localization of tracer uptake or even a fully diagnostic CT. In any case, SPECT/CT studies have to be optimized, e.g. by adapting dose reduction measures from state-of-the-art CT practice, and

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)

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)

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.

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?

U.S. Department of Energy Workers' mental models of radiation and chemical hazards in the workplace

International Nuclear Information System (INIS)

Quadrel, M.J.; Blanchard, K.A.; Lundgren, R.E.; McMakin, A.H.; Mosley, M.T.; Strom, D.J.

1994-05-01

A pilot study was performed to test the mental models methodology regarding knowledge and perceptions of U.S. Department of Energy contractor radiation workers about ionizing radiation and hazardous chemicals. The mental models methodology establishes a target population's beliefs about risks and compares them with current scientific knowledge. The ultimate intent is to develop risk communication guidelines that address information gaps or misperceptions that could affect decisions and behavior. In this study, 15 radiation workers from the Hanford Site in Washington State were interviewed about radiation exposure processes and effects. Their beliefs were mapped onto a science model of the same topics to see where differences occurred. In general, workers' mental models covered many of the high-level parts of the science model but did not have the same level of detail. The following concepts appeared to be well understood by most interviewees: types, form, and properties of workplace radiation; administrative and physical controls to reduce radiation exposure risk; and the relationship of dose and effects. However, several concepts were rarely mentioned by most interviewees, indicating potential gaps in worker understanding. Most workers did not discuss the wide range of measures for neutralizing or decontaminating individuals following internal contamination. Few noted specific ways of measuring dose or factors that affect dose. Few mentioned the range of possible effects, including genetic effects, birth defects, or high dose effects. Variables that influence potential effects were rarely discussed. Workers rarely mentioned how basic radiation principles influenced the source, type, or mitigation of radiation risk in the workplace

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

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)

Radiation risk models for all solid cancers other than those types of cancer requiring individual assessments after a nuclear accident

International Nuclear Information System (INIS)

Walsh, Linda; Zhang, Wei

2016-01-01

In the assessment of health risks after nuclear accidents, some health consequences require special attention. For example, in their 2013 report on health risk assessment after the Fukushima nuclear accident, the World Health Organisation (WHO) panel of experts considered risks of breast cancer, thyroid cancer and leukaemia. For these specific cancer types, use was made of already published excess relative risk (ERR) and excess absolute risk (EAR) models for radiation-related cancer incidence fitted to the epidemiological data from the Japanese A-bomb Life Span Study (LSS). However, it was also considered important to assess all other types of solid cancer together and the WHO, in their above-mentioned report, stated ''No model to calculate the risk for all other solid cancer excluding breast and thyroid cancer risks is available from the LSS data''. Applying the LSS models for all solid cancers along with the models for the specific sites means that some cancers have an overlap in the risk evaluations. Thus, calculating the total solid cancer risk plus the breast cancer risk plus the thyroid cancer risk can overestimate the total risk by several per cent. Therefore, the purpose of this paper was to publish the required models for all other solid cancers, i.e. all solid cancers other than those types of cancer requiring special attention after a nuclear accident. The new models presented here have been fitted to the same LSS data set from which the risks provided by the WHO were derived. Although it is known already that the EAR and ERR effect modifications by sex are statistically significant for the outcome ''all solid cancer'', it is shown here that sex modification is not statistically significant for the outcome ''all solid cancer other than thyroid and breast cancer''. It is also shown here that the sex-averaged solid cancer risks with and without the sex modification are very similar once breast and thyroid cancers are factored out. Some other notable model

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

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

A critical evaluation of secondary cancer risk models applied to Monte Carlo dose distributions of 2-dimensional, 3-dimensional conformal and hybrid intensity-modulated radiation therapy for breast cancer

International Nuclear Information System (INIS)

Joosten, A; Bochud, F; Moeckli, R

2014-01-01

The comparison of radiotherapy techniques regarding secondary cancer risk has yielded contradictory results possibly stemming from the many different approaches used to estimate risk. The purpose of this study was to make a comprehensive evaluation of different available risk models applied to detailed whole-body dose distributions computed by Monte Carlo for various breast radiotherapy techniques including conventional open tangents, 3D conformal wedged tangents and hybrid intensity modulated radiation therapy (IMRT). First, organ-specific linear risk models developed by the International Commission on Radiological Protection (ICRP) and the Biological Effects of Ionizing Radiation (BEIR) VII committee were applied to mean doses for remote organs only and all solid organs. Then, different general non-linear risk models were applied to the whole body dose distribution. Finally, organ-specific non-linear risk models for the lung and breast were used to assess the secondary cancer risk for these two specific organs. A total of 32 different calculated absolute risks resulted in a broad range of values (between 0.1% and 48.5%) underlying the large uncertainties in absolute risk calculation. The ratio of risk between two techniques has often been proposed as a more robust assessment of risk than the absolute risk. We found that the ratio of risk between two techniques could also vary substantially considering the different approaches to risk estimation. Sometimes the ratio of risk between two techniques would range between values smaller and larger than one, which then translates into inconsistent results on the potential higher risk of one technique compared to another. We found however that the hybrid IMRT technique resulted in a systematic reduction of risk compared to the other techniques investigated even though the magnitude of this reduction varied substantially with the different approaches investigated. Based on the epidemiological data available, a reasonable

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

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

Radiation dose dependent risk of liver cancer mortality in the German uranium miners cohort 1946–2003

International Nuclear Information System (INIS)

Dufey, F; Walsh, L; Sogl, M; Tschense, A; Schnelzer, M; Kreuzer, M

2013-01-01

An increased risk of mortality from primary liver cancers among uranium miners has been observed in various studies. An analysis of the data from a German uranium miner cohort (the ‘Wismut cohort’) was used to assess the relationship with ionising radiation. To that end the absorbed organ dose due to high and low linear energy transfer radiation was calculated for 58 987 miners with complete information on radiation exposure from a detailed job–exposure matrix. 159 deaths from liver cancer were observed in the follow-up period from 1946 to 2003. Relative risk models with either linear or categorical dependence on high and low linear energy transfer radiation liver doses were fitted by Poisson regression, stratified on age and calendar year. The linear trend of excess relative risk in a model with both low and high linear transfer radiation is −0.8 (95% confidence interval (CI): −3.7, 2.1) Gy −1 and 48.3 (95% CI: −32.0, 128.6) Gy −1 for low and high linear energy transfer radiation, respectively, and thus not statistically significant for either dose. The increase of excess relative risk with equivalent liver dose is 0.57 (95% CI: −0.69, 1.82) Sv −1 . Adjustment for arsenic only had a negligible effect on the radiation risk. In conclusion, there is only weak evidence for an increase of liver cancer mortality with increasing radiation dose in the German uranium miners cohort considered. However, both a lack of statistical power and potential misclassification of primary liver cancer are issues. (paper)

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

Science.gov (United States)

Schwartz, Boris; Benadjaoud, Mohamed Amine; Cléro, Enora; Haddy, Nadia; El-Fayech, Chiraz; Guibout, Catherine; Teinturier, Cécile; Oberlin, Odile; Veres, Cristina; Pacquement, Hélène; Munzer, Martine; N'guyen, Tan Dat; Bondiau, Pierre-Yves; Berchery, Delphine; Laprie, Anne; Hawkins, Mike; Winter, David; Lefkopoulos, Dimitri; Chavaudra, Jean; Rubino, Carole; Diallo, Ibrahima; Bénichou, Jacques; de Vathaire, Florent

2014-05-01

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 between 1942 and 1986 in France and Britain has been followed prospectively. We collected detailed information on treatments received during childhood cancer. Additionally, an innovative methodology has been developed to evaluate the dose-response relationship between bone sarcoma and radiation dose throughout this cohort. The median follow-up was 26 years, and 39 patients had developed bone sarcoma. It was found that the overall incidence was 45-fold higher [standardized incidence ratio 44.8, 95 % confidence interval (CI) 31.0-59.8] than expected from the general population, and the absolute excess risk was 35.1 per 100,000 person-years (95 % CI 24.0-47.1). The risk of bone sarcoma increased slowly up to a cumulative radiation organ absorbed dose of 15 Gy [hazard ratio (HR) = 8.2, 95 % CI 1.6-42.9] and then strongly increased for higher radiation doses (HR for 30 Gy or more 117.9, 95 % CI 36.5-380.6), compared with patients not treated with radiotherapy. A linear model with an excess relative risk per Gy of 1.77 (95 % CI 0.6213-5.935) provided a close fit to the data. These findings have important therapeutic implications: Lowering the radiation dose to the bones should reduce the incidence of secondary bone sarcomas. Other therapeutic solutions should be preferred to radiotherapy in bone sarcoma-sensitive areas.

Risk Factors for Cataract After Palladium-103 Ophthalmic Plaque Radiation Therapy

International Nuclear Information System (INIS)

Finger, Paul T.; Chin, Kimberly J.; Yu Guopei; Patel, Neil S.

2011-01-01

Purpose: To examine how tumor characteristics and dose affect cataract development after plaque radiation therapy. Methods and Materials: Three hundred and eighty-four patients were diagnosed with uveal melanoma and treated with palladium-103 ( 103 Pd) plaque radiation therapy. Of these, 282 (74%) inclusion met exclusion criteria for follow-up time, tumor location, and phakic status. Then patient-, ophthalmic-, and radiation-specific factors (patient age, diabetes, hypertension, tumor location, tumor dimensions, and lens dose) were examined (by a Cox proportional regression model) as predictors for the development of radiation-related cataract. Results: Radiation cataract developed in 76 (24%) of patients at a mean follow-up of 39.8 months (range, 1-192). Patients with anteriorly located tumors were noted to have a higher incidence of cataract at 43.0% (43 of 100 patients) vs. 18.1% (33 cataracts per 182 patients) for posteriorly located tumors (p <0.0001). However, multivariate Cox proportional modeling showed that increasing patient age at time of treatment (p for trend = 0.0003) and higher lens dose (p for trend = 0.001) were the best predictors (biomarkers) for radiation cataract. Conclusions: Although anterior tumor location, greater tumor height, and increased patient age (at treatment) were associated with significantly greater risk for radiation cataract, dose to lens was the most significant factor.

Formation of potential radiation risk groups to render timely targeted medical care: Lessons of Chernobyl

International Nuclear Information System (INIS)

Ivanov, V. K.; Kashcheev, V. V.; Zamulaeva, I. A.; Saenko, A. S.; Orlova, N. V.; Smirnova, S. G.; Korelo, A. M.; Gorsky, A. I.; Maksioutov, M. A.

2012-01-01

The paper discusses technology for establishing potential cancer risk groups, based on methods of molecular and radiation epidemiology. Assay of gene mutations at the T-cell receptor (TCR) locus as the method of molecular epidemiology was used for measuring the frequency of TCR-mutations in 320 nuclear workers of the Inst. of Physics and Power Engineering (IPPE). The method of radiation epidemiology was applied to the estimation of attributable risk fraction (ARF) for solid cancers in these groups. The main estimates of radiation risk after the Chernobyl accident are in close agreement with the International Commission on Radiological Protection (ICRP) Publication, 103 models published in 2007. In nuclear workers of the IPPE with ARF ≥ 10%, the increased level of TCR-mutations occurs more often (risk ratio=9.7; 95% CI: 2.9; 32.1). (authors)

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

Development of model for assessment of radiation discharge to the environment

International Nuclear Information System (INIS)

Shang Zhaorong; Wu Hao; Liu Hua

2003-01-01

International Atomic Energy Agency (IAEA) establish basic and detailed requirements for protection against the risks associated with exposure to radiation and for the safety of radiation sources that may deliver such exposure, in which, particularly emphasize to 'make an assessment of the nature, magnitude and likelihood of the exposure attributed to the source'. It is clear that the assessment of the consequential radiation exposure arising from any releases of radioactive materials to the environment will have to rely on some form of model. This paper summary recent progress in radiation protection policy and radioecology research and primary concludes the basis requirements in assessment model development

Risk Perception and Anxiety Regarding Radiation after the 2011 Fukushima Nuclear Power Plant Accident: A Systematic Qualitative Review

Directory of Open Access Journals (Sweden)

Yoshitake Takebayashi

2017-10-01

Full Text Available The purpose of this study was to provide a review of the publications of the risk perceptions or anxiety regarding radiation among people living in Japan after the 2011 Fukushima nuclear power plant accident. Two database (MEDLINE and PsycINFO and hand-searched the references in identified publications were searched. For each identified publication, the measurements and time related-change of risk perception and anxiety regarding radiation were summarized. Twenty-four publications were identified. Quantitative measures of risk perception or anxiety were roughly divided into two types: single-item Likert scales that measure anxiety about radiation; and theoretical, or model-based measures. Rates of Fukushima residents with radiation-related anxiety decreased from 2012 to 2015. Factors governing risk perception or radiation-related anxiety were summarized by demographics, disaster-related stressors, trusted information, and radiation-related variables. The effects of risk perception or anxiety regarding radiation were summarized as severe distress, intention to leave employment or not to return home, or other dimensions. This review provides summary of current findings on risk perception or anxiety regarding radiation in Japan after the accident. Further researches are needed about detailed statistical analysis for time-related change and causality among variables.

Modeling human risk: Cell ampersand molecular biology in context

International Nuclear Information System (INIS)

1997-06-01

It is anticipated that early in the next century manned missions into outer space will occur, with a mission to Mars scheduled between 2015 and 2020. However, before such missions can be undertaken, a realistic estimation of the potential risks to the flight crews is required. One of the uncertainties remaining in this risk estimation is that posed by the effects of exposure to the radiation environment of outer space. Although the composition of this environment is fairly well understood, the biological effects arising from exposure to it are not. The reasons for this are three-fold: (1) A small but highly significant component of the radiation spectrum in outer space consists of highly charged, high energy (HZE) particles which are not routinely experienced on earth, and for which there are insufficient data on biological effects; (2) Most studies on the biological effects of radiation to date have been high-dose, high dose-rate, whereas in space, with the exception of solar particle events, radiation exposures will be low-dose, low dose-rate; (3) Although it has been established that the virtual absence of gravity in space has a profound effect on human physiology, it is not clear whether these effects will act synergistically with those of radiation exposure. A select panel will evaluate the utilizing experiments and models to accurately predict the risks associated with exposure to HZE particles. Topics of research include cellular and tissue response, health effects associated with radiation damage, model animal systems, and critical markers of Radiation response

Stochastic Model for Population Exposed to Low Level Risk

International Nuclear Information System (INIS)

Merkle, J.M.

1996-01-01

In this paper the stochastic model for population size, i.e. calculation of the number of deaths due to lethal stochastic health effects caused by the exposure to low level ionising radiation is presented. The model is defined for subpopulation with parameter (a, b) being fixed. Using the corresponding density function, it is possible to find all the quantities of interest by averaging over whole possible values for (a, l). All processes ar at first defined for one radionuclide, exposure pathway and the health effect under consideration. The results obtained in this paper are the basic quantities in the risk assessment, loss of life expectancy etc. The results presented in this paper are also applicable to the other sources of low level risk, not only the radiation risk

XRCC3 polymorphisms are associated with the risk of developing radiation-induced late xerostomia in nasopharyngeal carcinoma patients treated with intensity modulation radiated therapy.

Science.gov (United States)

Zou, Yan; Song, Tao; Yu, Wei; Zhao, Ruping; Wang, Yong; Xie, Ruifei; Chen, Tian; Wu, Bo; Wu, Shixiu

2014-03-01

The incidence of radiation-induced late xerostomia varies greatly in nasopharyngeal carcinoma patients treated with radiotherapy. The single-nucleotide polymorphisms in genes involved in DNA repair and fibroblast proliferation may be correlated with such variability. The purpose of this paper was to evaluate the association between the risk of developing radiation-induced late xerostomia and four genetic polymorphisms: TGFβ1 C-509T, TGFβ1 T869C, XRCC3 722C>T and ATM 5557G>A in nasopharyngeal carcinoma patients treated with Intensity Modulation Radiated Therapy. The severity of late xerostomia was assessed using a patient self-reported validated xerostomia questionnaire. Polymerase chain reaction-ligation detection reaction methods were performed to determine individual genetic polymorphism. The development of radiation-induced xerostomia associated with genetic polymorphisms was modeled using Cox proportional hazards, accounting for equivalent uniform dose. A total of 43 (41.7%) patients experienced radiation-induced late xerostomia. Univariate Cox proportional hazard analyses showed a higher risk of late xerostomia for patients with XRCC3 722 TT/CT alleles. In multivariate analysis adjusted for clinical and dosimetric factors, XRCC3 722C>T polymorphisms remained a significant factor for higher risk of late xerostomia. To our knowledge, this is the first study that demonstrated an association between genetic polymorphisms and the risk of radiation-induced late xerostomia in nasopharyngeal carcinoma patients treated with Intensity Modulation Radiated Therapy. Our findings suggest that the polymorphisms in XRCC3 are significantly associated with the risk of developing radiation-induced late xerostomia.

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.

Low Dose Radiation Cancer Risks: Epidemiological and Toxicological Models

Energy Technology Data Exchange (ETDEWEB)

David G. Hoel, PhD

2012-04-19

The basic purpose of this one year research grant was to extend the two stage clonal expansion model (TSCE) of carcinogenesis to exposures other than the usual single acute exposure. The two-stage clonal expansion model of carcinogenesis incorporates the biological process of carcinogenesis, which involves two mutations and the clonal proliferation of the intermediate cells, in a stochastic, mathematical way. The current TSCE model serves a general purpose of acute exposure models but requires numerical computation of both the survival and hazard functions. The primary objective of this research project was to develop the analytical expressions for the survival function and the hazard function of the occurrence of the first cancer cell for acute, continuous and multiple exposure cases within the framework of the piece-wise constant parameter two-stage clonal expansion model of carcinogenesis. For acute exposure and multiple exposures of acute series, it is either only allowed to have the first mutation rate vary with the dose, or to have all the parameters be dose dependent; for multiple exposures of continuous exposures, all the parameters are allowed to vary with the dose. With these analytical functions, it becomes easy to evaluate the risks of cancer and allows one to deal with the various exposure patterns in cancer risk assessment. A second objective was to apply the TSCE model with varing continuous exposures from the cancer studies of inhaled plutonium in beagle dogs. Using step functions to estimate the retention functions of the pulmonary exposure of plutonium the multiple exposure versions of the TSCE model was to be used to estimate the beagle dog lung cancer risks. The mathematical equations of the multiple exposure versions of the TSCE model were developed. A draft manuscript which is attached provides the results of this mathematical work. The application work using the beagle dog data from plutonium exposure has not been completed due to the fact

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.)

Sensitivity Analysis of Median Lifetime on Radiation Risks Estimates for Cancer and Circulatory Disease amongst Never-Smokers

Science.gov (United States)

Chappell, Lori J.; Cucinotta, Francis A.

2011-01-01

Radiation risks are estimated in a competing risk formalism where age or time after exposure estimates of increased risks for cancer and circulatory diseases are folded with a probability to survive to a given age. The survival function, also called the life-table, changes with calendar year, gender, smoking status and other demographic variables. An outstanding problem in risk estimation is the method of risk transfer between exposed populations and a second population where risks are to be estimated. Approaches used to transfer risks are based on: 1) Multiplicative risk transfer models -proportional to background disease rates. 2) Additive risk transfer model -risks independent of background rates. In addition, a Mixture model is often considered where the multiplicative and additive transfer assumptions are given weighted contributions. We studied the influence of the survival probability on the risk of exposure induced cancer and circulatory disease morbidity and mortality in the Multiplicative transfer model and the Mixture model. Risks for never-smokers (NS) compared to the average U.S. population are estimated to be reduced between 30% and 60% dependent on model assumptions. Lung cancer is the major contributor to the reduction for NS, with additional contributions from circulatory diseases and cancers of the stomach, liver, bladder, oral cavity, esophagus, colon, a portion of the solid cancer remainder, and leukemia. Greater improvements in risk estimates for NS s are possible, and would be dependent on improved understanding of risk transfer models, and elucidating the role of space radiation on the various stages of disease formation (e.g. initiation, promotion, and progression).

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

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.)

Radiation induced muscositis as space flight risk. Model studies on X-ray and heavy ion irradiated typical oral mucosa models; Strahlungsinduzierte Mukositis als Risiko der Raumfahrt. Modelluntersuchungen an Roentgen- und Schwerionen-bestrahlten organotypischen Mundschleimhaut-Modellen

Energy Technology Data Exchange (ETDEWEB)

Tschachojan, Viktoria

2014-07-29

Humans in exomagnetospheric space are exposed to highly energetic heavy ion radiation which can be hardly shielded. Since radiation-induced mucositis constitutes a severe complication of heavy ion radiotherapy, it would also implicate a serious medical safety risk for the crew members during prolonged space flights such as missions to Moon or Mars. For assessment of risk developing radiation-induced mucositis, three-dimensional organotypic cultures of immortalized human keratinocytes and fibroblasts were irradiated with a {sup 12}C particle beam at high energies or X-Rays. Immunofluorescence stainings were done from cryosections and radiation induced release of cytokines and chemokines was quantified by ELISA from culture supernatants. The major focuses of this study were on 4, 8, 24 and 48 hours after irradiation. The conducted analyses of our mucosa model showed many structural similarities with the native oral mucosa and authentic immunological responses to radiation exposure. Quantification of the DNA damage in irradiated mucosa models revealed about twice as many DSB after heavy-ion irradiation compared to X-rays at definite doses and time points, suggesting a higher gene toxicity of heavy ions. Nuclear factor κB activation was observed after treatment with X-rays or {sup 12}C particles. An activation of NF κB p65 in irradiated samples could not be detected. ELISA analyses showed significantly higher interleukin 6 and interleukin 8 levels after irradiation with X-rays and {sup 12}C particles compared to non-irradiated controls. However, only X-rays induced significantly higher levels of interleukin 1β. Analyses of TNF-α and IFN-γ showed no radiation-induced effects. Further analyses revealed a radiation-induced reduction in proliferation and loss of compactness in irradiated oral mucosa model, which would lead to local lesions in vivo. In this study we revealed that several pro-inflammatory markers and structural changes are induced by X-rays and heavy

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

A framework for estimating radiation-related cancer risks in Japan from the 2011 Fukushima nuclear accident.

Science.gov (United States)

Walsh, L; Zhang, W; Shore, R E; Auvinen, A; Laurier, D; Wakeford, R; Jacob, P; Gent, N; Anspaugh, L R; Schüz, J; Kesminiene, A; van Deventer, E; Tritscher, A; del Rosarion Pérez, M

2014-11-01

We present here a methodology for health risk assessment adopted by the World Health Organization that provides a framework for estimating risks from the Fukushima nuclear accident after the March 11, 2011 Japanese major earthquake and tsunami. Substantial attention has been given to the possible health risks associated with human exposure to radiation from damaged reactors at the Fukushima Daiichi nuclear power station. Cumulative doses were estimated and applied for each post-accident year of life, based on a reference level of exposure during the first year after the earthquake. A lifetime cumulative dose of twice the first year dose was estimated for the primary radionuclide contaminants ((134)Cs and (137)Cs) and are based on Chernobyl data, relative abundances of cesium isotopes, and cleanup efforts. Risks for particularly radiosensitive cancer sites (leukemia, thyroid and breast cancer), as well as the combined risk for all solid cancers were considered. The male and female cumulative risks of cancer incidence attributed to radiation doses from the accident, for those exposed at various ages, were estimated in terms of the lifetime attributable risk (LAR). Calculations of LAR were based on recent Japanese population statistics for cancer incidence and current radiation risk models from the Life Span Study of Japanese A-bomb survivors. Cancer risks over an initial period of 15 years after first exposure were also considered. LAR results were also given as a percentage of the lifetime baseline risk (i.e., the cancer risk in the absence of radiation exposure from the accident). The LAR results were based on either a reference first year dose (10 mGy) or a reference lifetime dose (20 mGy) so that risk assessment may be applied for relocated and non-relocated members of the public, as well as for adult male emergency workers. The results show that the major contribution to LAR from the reference lifetime dose comes from the first year dose. For a dose of 10 mGy in

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

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.

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.

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.

[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.

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.”

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.”.

Genetic radiation risks: a neglected topic in the low dose debate

Directory of Open Access Journals (Sweden)

Inge Schmitz-Feuerhake

2016-01-01

Full Text Available Objectives To investigate the accuracy and scientific validity of the current very low risk factor for hereditary diseases in humans following exposures to ionizing radiation adopted by the United Nations Scientific Committee on the Effects of Atomic Radiation and the International Commission on Radiological Protection. The value is based on experiments on mice due to reportedly absent effects in the Japanese atomic bomb (Abomb survivors. Methods To review the published evidence for heritable effects after ionising radiation exposures particularly, but not restricted to, populations exposed to contamination from the Chernobyl accident and from atmospheric nuclear test fallout. To make a compilation of findings about early deaths, congenital malformations, Down’s syndrome, cancer and other genetic effects observed in humans after the exposure of the parents. To also examine more closely the evidence from the Japanese A-bomb epidemiology and discuss its scientific validity. Results Nearly all types of hereditary defects were found at doses as low as one to 10 mSv. We discuss the clash between the current risk model and these observations on the basis of biological mechanism and assumptions about linear relationships between dose and effect in neonatal and foetal epidemiology. The evidence supports a dose response relationship which is non-linear and is either biphasic or supralinear (hogs-back and largely either saturates or falls above 10 mSv. Conclusions We conclude that the current risk model for heritable effects of radiation is unsafe. The dose response relationship is non-linear with the greatest effects at the lowest doses. Using Chernobyl data we derive an excess relative risk for all malformations of 1.0 per 10 mSv cumulative dose. The safety of the Japanese A-bomb epidemiology is argued to be both scientifically and philosophically questionable owing to errors in the choice of control groups, omission of internal exposure effects and

Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit

Science.gov (United States)

Chancellor, Jeffery C.; Scott, Graham B. I.; Sutton, Jeffrey P.

2014-01-01

Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS) decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO). Shielding is an effective countermeasure against solar particle events (SPEs), but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR) nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts. PMID:25370382

Space Radiation: The Number One Risk to Astronaut Health beyond Low Earth Orbit

Directory of Open Access Journals (Sweden)

Jeffery C. Chancellor

2014-09-01

Full Text Available Projecting a vision for space radiobiological research necessitates understanding the nature of the space radiation environment and how radiation risks influence mission planning, timelines and operational decisions. Exposure to space radiation increases the risks of astronauts developing cancer, experiencing central nervous system (CNS decrements, exhibiting degenerative tissue effects or developing acute radiation syndrome. One or more of these deleterious health effects could develop during future multi-year space exploration missions beyond low Earth orbit (LEO. Shielding is an effective countermeasure against solar particle events (SPEs, but is ineffective in protecting crew members from the biological impacts of fast moving, highly-charged galactic cosmic radiation (GCR nuclei. Astronauts traveling on a protracted voyage to Mars may be exposed to SPE radiation events, overlaid on a more predictable flux of GCR. Therefore, ground-based research studies employing model organisms seeking to accurately mimic the biological effects of the space radiation environment must concatenate exposures to both proton and heavy ion sources. New techniques in genomics, proteomics, metabolomics and other “omics” areas should also be intelligently employed and correlated with phenotypic observations. This approach will more precisely elucidate the effects of space radiation on human physiology and aid in developing personalized radiological countermeasures for astronauts.

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

Some statistical considerations related to the estimation of cancer risk following exposure to ionizing radiation

International Nuclear Information System (INIS)

Land, C.E.; Pierce, D.A.

1983-01-01

Statistical theory and methodology provide the logical structure for scientific inference about the cancer risk associated with exposure to ionizing radiation. Although much is known about radiation carcinogenesis, the risk associated with low-level exposures is difficult to assess because it is too small to measure directly. Estimation must therefore depend upon mathematical models which relate observed risks at high exposure levels to risks at lower exposure levels. Extrapolated risk estimates obtained using such models are heavily dependent upon assumptions about the shape of the dose-response relationship, the temporal distribution of risk following exposure, and variation of risk according to variables such as age at exposure, sex, and underlying population cancer rates. Expanded statistical models, which make explicit certain assumed relationships between different data sets, can be used to strengthen inferences by incorporating relevant information from diverse sources. They also allow the uncertainties inherent in information from related data sets to be expressed in estimates which partially depend upon that information. To the extent that informed opinion is based upon a valid assessment of scientific data, the larger context of decision theory, which includes statistical theory, provides a logical framework for the incorporation into public policy decisions of the informational content of expert opinion

Evidence Report: Risk of Cardiovascular Disease and Other Degenerative Tissue Effects from Radiation Exposure

Science.gov (United States)

Patel, Zarana; Huff, Janice; Saha, Janapriya; Wang, Minli; Blattnig, Steve; Wu, Honglu; Cucinotta, Francis

2015-01-01

(SI unit for ionizing radiation dosage, i.e. one joule of radiation energy per one kilogram of matter)) to facilitate risk prediction. This risk has considerable uncertainty associated with it, and no acceptable model for projecting degenerative tissue risk is currently available. In particular, risk factors such as obesity, alcohol, and tobacco use can act as confounding factors that contribute to the large uncertainties. The PELs could be violated under certain scenarios, including following a large SPE (solar proton event) or long-term GCR (galactic cosmic ray) exposure. Specifically, for a Mars mission, the accumulated dose is sufficiently high that epidemiology data and preliminary risk estimates suggest a significant risk for cardiovascular disease. Ongoing research in this area is intended to provide the evidence base for accurate risk quantification to determine criticality for extended duration missions. Data specific to the space radiation environment must be compiled to quantify the magnitude of this risk to decrease the uncertainty in current PELs and to determine if additional protection strategies are required. New research results could lead to estimates of cumulative radiation risk from CNS and degenerative tissue diseases that, when combined with the cancer risk, may have major negative impacts on mission design, costs, schedule, and crew selection. The current report amends an earlier report (Human Research Program Requirements Document, HRP-47052, Rev. C, dated Jan 2009) in order to provide an update of evidence since 2009.

What Becomes of Nuclear Risk Assessment in Light of Radiation Hormesis?

International Nuclear Information System (INIS)

Cuttler, J.M.

2004-01-01

A nuclear probabilistic risk or safety assessment (PRA or PSA) is a scientific calculation that uses very pessimistic assumptions and models to determine the likelihood of plant or fuel repository failures and the corresponding releases of radioactivity. Although PRAs demonstrate that nuclear power plants and fuel repositories are very safe compared with the risks of other generating options or other risks that people readily accept, frightening negative images are formed and exaggerated safety and health concerns are communicated. Large-scale tests and experience with nuclear accidents demonstrate that such incidents expose the public to low doses of radiation, and a century of research and experience have demonstrated that such exposures are beneficial to health. PRAs are valuable tools for improving plant designs, but if nuclear power is to play a significant role in meeting future energy needs, we must communicate its many real benefits and dispel the negative images formed by unscientific extrapolations of the harmful effects that occur at high radiation doses

Estimated risk of radiation-induced cancer from paediatric chest CT: two-year cohort study

Energy Technology Data Exchange (ETDEWEB)

Niemann, Tilo [Cantonal Hospital Baden, Department of Radiology, Baden (Switzerland); University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Colas, Lucie; Santangelo, Teresa; Faivre, Jean Baptiste; Remy, Jacques; Remy-Jardin, Martine [University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Roser, Hans W.; Bremerich, Jens [University of Basel Hospital, Clinic of Radiology and Nuclear Medicine, Medical Physics, Basel (Switzerland)

2015-03-01

The increasing absolute number of paediatric CT scans raises concern about the safety and efficacy and the effects of consecutive diagnostic ionising radiation. To demonstrate a method to evaluate the lifetime attributable risk of cancer incidence/mortality due to a single low-dose helical chest CT in a two-year patient cohort. A two-year cohort of 522 paediatric helical chest CT scans acquired using a dedicated low-dose protocol were analysed retrospectively. Patient-specific estimations of radiation doses were modelled using three different mathematical phantoms. Per-organ attributable cancer risk was then estimated using epidemiological models. Additional comparison was provided for naturally occurring risks. Total lifetime attributable risk of cancer incidence remains low for all age and sex categories, being highest in female neonates (0.34%). Summation of all cancer sites analysed raised the relative lifetime attributable risk of organ cancer incidence up to 3.6% in female neonates and 2.1% in male neonates. Using dedicated scan protocols, total lifetime attributable risk of cancer incidence and mortality for chest CT is estimated low for paediatric chest CT, being highest for female neonates. (orig.)

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

Radiation risk models for all solid cancers other than those types of cancer requiring individual assessments after a nuclear accident

Energy Technology Data Exchange (ETDEWEB)

Walsh, Linda [Federal Office for Radiation Protection, Department ' ' Radiation Protection and Health' ' , Oberschleissheim (Germany); University of Zurich, Medical Physics Group, Institute of Physics, Zurich (Switzerland); Zhang, Wei [Public Health England, Centre for Radiation, Chemical and Environmental Hazards, Oxford (United Kingdom)

2016-03-15

In the assessment of health risks after nuclear accidents, some health consequences require special attention. For example, in their 2013 report on health risk assessment after the Fukushima nuclear accident, the World Health Organisation (WHO) panel of experts considered risks of breast cancer, thyroid cancer and leukaemia. For these specific cancer types, use was made of already published excess relative risk (ERR) and excess absolute risk (EAR) models for radiation-related cancer incidence fitted to the epidemiological data from the Japanese A-bomb Life Span Study (LSS). However, it was also considered important to assess all other types of solid cancer together and the WHO, in their above-mentioned report, stated ''No model to calculate the risk for all other solid cancer excluding breast and thyroid cancer risks is available from the LSS data''. Applying the LSS models for all solid cancers along with the models for the specific sites means that some cancers have an overlap in the risk evaluations. Thus, calculating the total solid cancer risk plus the breast cancer risk plus the thyroid cancer risk can overestimate the total risk by several per cent. Therefore, the purpose of this paper was to publish the required models for all other solid cancers, i.e. all solid cancers other than those types of cancer requiring special attention after a nuclear accident. The new models presented here have been fitted to the same LSS data set from which the risks provided by the WHO were derived. Although it is known already that the EAR and ERR effect modifications by sex are statistically significant for the outcome ''all solid cancer'', it is shown here that sex modification is not statistically significant for the outcome ''all solid cancer other than thyroid and breast cancer''. It is also shown here that the sex-averaged solid cancer risks with and without the sex modification are very similar once breast and

Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights

Science.gov (United States)

Denkins, P.; Badhwar, G.; Obot, V.; Wilson, B.; Jejelewo, O.

2001-01-01

NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far. the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space. exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation

Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights

Science.gov (United States)

Denkins, Pamela; Badhwar, Gautam; Obot, Victor; Wilson, Bobby; Jejelewo, Olufisayo

2001-08-01

NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far, the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space, exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation

Methods and models used in comparative risk studies

International Nuclear Information System (INIS)

Devooght, J.

1983-01-01

Comparative risk studies make use of a large number of methods and models based upon a set of assumptions incompletely formulated or of value judgements. Owing to the multidimensionality of risks and benefits, the economic and social context may notably influence the final result. Five classes of models are briefly reviewed: accounting of fluxes of effluents, radiation and energy; transport models and health effects; systems reliability and bayesian analysis; economic analysis of reliability and cost-risk-benefit analysis; decision theory in presence of uncertainty and multiple objectives. Purpose and prospect of comparative studies are assessed in view of probable diminishing returns for large generic comparisons [fr

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

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

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

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)

Selected materials of the international workshop on radiation risk and its origin at molecular and cellular level

International Nuclear Information System (INIS)

Pinak, Miroslav

2003-11-01

The workshop ''International Workshop on Radiation Risk and its Origin at Molecular and Cellular Level'' was held at The Tokai Research Establishment, Japan Atomic Energy Research Institute, on the 6th and 7th of February 2003. The Laboratory of Radiation Risk Analysis of JAERI organized it. This international workshop attracted scientists from several different scientific areas, including radiation physics, radiation biology, molecular biology, crystallography of biomolecules, modeling and bio-informatics. Several foreign and domestic keynote speakers addresses the very fundamental areas of radiation risk and tried to establish a link between the fundamental studies at the molecular and cellular level and radiation damages at the organism. The symposium consisted of 13 oral lectures, 10 poster presentations and panel discussion. The 108 participants attended the workshop. This publication comprises of proceedings of oral and poster presentations where available. For the rest of contributions the abstracts or/and selections of presentation materials are shown instead. The 5 papers are indexed individually. (J.P.N.)

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...

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

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

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)

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

An integrated model for radiation induced cancer

International Nuclear Information System (INIS)

Hall, E.J.; Varma, M.

1994-01-01

Risk estimates for radiation induced cancer are based on epidemiological data, principally the Japanese A bomb survivors. These estimates for radiation are better known than for any other environmental pollutant, but they do not relate directly to exposure to low doses and low dose rate. Recent rapid advances in molecular genetics, coupled with steady gains in cellular biology, radiation physics and chemistry led to the notion that the time may not be far off when it may be possible to arrive at human cancer risk estimates entirely from laboratory data. Whether risk estimates based on laboratory data will ever replace estimates based on epidemiological studies is an open question. What is clear is that laboratory data can supplement the present risk estimates by providing information on the relative effectiveness of high LET radiations, the importance of dose rate and dose protraction, and by identifying subpopulations which are unusually sensitive or resistant to radiation carcinogenesis. (author)

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.

Cancer risk from low doses of ionizing radiation

Energy Technology Data Exchange (ETDEWEB)

Auvinen, A

1997-06-01

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

Cancer risk from low doses of ionizing radiation

International Nuclear Information System (INIS)

Auvinen, A.

1997-06-01

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

Genetic instability model for cancer risk in A-bomb survivors

International Nuclear Information System (INIS)

Niwa, Ohtsura

1998-01-01

This review was written rather against Mendelsohn's reductionist model for cancer risk in A-bomb survivors in following chapters. Assumptions for carcinogenic process: mutation of a cell to the cancer cell and its proliferation. Multi-step theory for carcinogenesis and age of crisis: induction of cancer by accumulation of cancer-related gene mutations which being linear to time (age). Effect of exogenous hit in the multi-step theory: radiation as an exogenous hit to damage DNA. Dose-effect relationship for cancer risk in the survivors and the problem for the latent period: for solid tumors, dose-effect relationship is linear and shortening of the latent period is not observed. Considerations on cancer data in adulthood exposure/Indirect effect model in radiation carcinogenesis: solid cancer data supporting the indirect effect model. Possible mechanism for radiation-induced long-term increase of natural mutation frequency: genetic instability remaining in the irradiated cells which being a basis of the indirect effect model. Notes for considerations of carcinogenicity in exposed people/Difference in carcinogenic mechanisms due to age. The author concluded that the radiation-induced carcinogenesis is deeply related with the natural carcinogenesis and particularly for solid cancers, it can not be explained by the classic reductionist model. (K.H.)

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.

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

Patients with Testicular Cancer Undergoing CT Surveillance Demonstrate a Pitfall of Radiation-induced Cancer Risk Estimates: The Timing Paradox

Science.gov (United States)

Eisenberg, Jonathan D.; Lee, Richard J.; Gilmore, Michael E.; Turan, Ekin A.; Singh, Sarabjeet; Kalra, Mannudeep K.; Liu, Bob; Kong, Chung Yin; Gazelle, G. Scott

2013-01-01

Purpose: To demonstrate a limitation of lifetime radiation-induced cancer risk metrics in the setting of testicular cancer surveillance—in particular, their failure to capture the delayed timing of radiation-induced cancers over the course of a patient’s lifetime. Materials and Methods: Institutional review board approval was obtained for the use of computed tomographic (CT) dosimetry data in this study. Informed consent was waived. This study was HIPAA compliant. A Markov model was developed to project outcomes in patients with testicular cancer who were undergoing CT surveillance in the decade after orchiectomy. To quantify effects of early versus delayed risks, life expectancy losses and lifetime mortality risks due to testicular cancer were compared with life expectancy losses and lifetime mortality risks due to radiation-induced cancers from CT. Projections of life expectancy loss, unlike lifetime risk estimates, account for the timing of risks over the course of a lifetime, which enabled evaluation of the described limitation of lifetime risk estimates. Markov chain Monte Carlo methods were used to estimate the uncertainty of the results. Results: As an example of evidence yielded, 33-year-old men with stage I seminoma who were undergoing CT surveillance were projected to incur a slightly higher lifetime mortality risk from testicular cancer (598 per 100 000; 95% uncertainty interval [UI]: 302, 894) than from radiation-induced cancers (505 per 100 000; 95% UI: 280, 730). However, life expectancy loss attributable to testicular cancer (83 days; 95% UI: 42, 124) was more than three times greater than life expectancy loss attributable to radiation-induced cancers (24 days; 95% UI: 13, 35). Trends were consistent across modeled scenarios. Conclusion: Lifetime radiation risk estimates, when used for decision making, may overemphasize radiation-induced cancer risks relative to short-term health risks. © RSNA, 2012 Supplemental material: http

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)

Low level radiation: how does the linear without threshold model provide the safety of Canadian

International Nuclear Information System (INIS)

Anon.

2010-01-01

The linear without threshold model is a model of risk used worldwide by the most of health organisms of nuclear regulation in order to establish dose limits for workers and public. It is in the heart of the approach adopted by the Canadian commission of nuclear safety (C.C.S.N.) in matter of radiation protection. The linear without threshold model presumes reasonably it exists a direct link between radiation exposure and cancer rate. It does not exist scientific evidence that chronicle exposure to radiation doses under 100 milli sievert (mSv) leads harmful effects on health. Several scientific reports highlighted scientific evidences that seem indicate a low level of radiation is less harmful than the linear without threshold predicts. As the linear without threshold model presumes that any radiation exposure brings risks, the ALARA principle obliges the licensees to get the radiation exposure at the lowest reasonably achievable level, social and economical factors taken into account. ALARA principle constitutes a basic principle in the C.C.S.N. approach in matter of radiation protection; On the radiation protection plan, C.C.S.N. gets a careful approach that allows to provide health and safety of Canadian people and the protection of their environment. (N.C.)

Using multistage models to describe radiation-induced leukaemia

International Nuclear Information System (INIS)

Little, M.P.; Muirhead, C.R.; Boice, J.D. Jr.; Kleinerman, R.A.

1995-01-01

The Armitage-Doll model of carcinogenesis is fitted to data on leukaemia mortality among the Japanese atomic bomb survivors with the DS86 dosimetry and on leukaemia incidence in the International Radiation Study of Cervical Cancer patients. Two different forms of model are fitted: the first postulates up to two radiation-affected stages and the second additionally allows for the presence at birth of a non-trivial population of cells which have already accumulated the first of the mutations leading to malignancy. Among models of the first form, a model with two adjacent radiation-affected stages appears to fit the data better than other models of the first form, including both models with two affected stages in any order and models with only one affected stage. The best fitting model predicts a linear-quadratic dose-response and reductions of relative risk with increasing time after exposure and age at exposure, in agreement with what has previously been observed in the Japanese and cervical cancer data. However, on the whole it does not provide an adequate fit to either dataset. The second form of model appears to provide a rather better fit, but the optimal models have biologically implausible parameters (the number of initiated cells at birth is negative) so that this model must also be regarded as providing an unsatisfactory description of the data. (author)

The concept of radiological risk and the epidemiology of the ionizing radiation

International Nuclear Information System (INIS)

Angeles C, A.; Garcia M, T.; Benitez S, J. A.

2013-10-01

The present work has as objective to describe in general way which is the methodology to be able to propose and to determine the exhibition limits of the ionizing radiations in terms of the radiological risk. First a description of the radiological risk concept is made, considering that the concept has more than a meaning, but that technical and scientifically is a punctual concept. Starting from the understanding of the term risk and example of numeric calculation of the same one is made and next a description of the epidemiology meaning is made. The epidemiology concept is described and a brief description of three of the main epidemic methods is made: the ecological, analytic, (divided in case-control) and cohort studies. A description is made of how starting from the statistical data of cohort studies the mortality data are obtained in terms of the cause-effect relationship, being these dose-cancer like the main stochastic effect and later on starting from these data models are proposed to describe the radiological risk. As the dose levels of the considered cohorts are very high in comparison with the normal labor levels, then the cause-effect models should be extrapolated for low dose levels, once established these models are to decide the grade of acceptable risk for the activity that involves the use of ionizing radiations, starting from there and with numeric values the dose limits to recommend are established and that would be adopted by the countries or regions in terms of their social, economic and technical conditions. (Author)

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.

Evidence Report: Risk of Acute and Late Central Nervous System Effects from Radiation Exposure

Science.gov (United States)

Nelson, Gregory A.; Simonsen, Lisa; Huff, Janice L.

2016-01-01

Possible acute and late risks to the central nervous system (CNS) from galactic cosmic rays (GCR) and solar particle events (SPE) are concerns for human exploration of space. Acute CNS risks may include: altered cognitive function, reduced motor function, and behavioral changes, all of which may affect performance and human health. Late CNS risks may include neurological disorders such as Alzheimer's disease (AD), dementia and premature aging. Although detrimental CNS changes are observed in humans treated with high-dose radiation (e.g., gamma rays and 9 protons) for cancer and are supported by experimental evidence showing neurocognitive and behavioral effects in animal models, the significance of these results on the morbidity to astronauts has not been elucidated. There is a lack of human epidemiology data on which to base CNS risk estimates; therefore, risk projection based on scaling to human data, as done for cancer risk, is not possible for CNS risks. Research specific to the spaceflight environment using animal and cell models must be compiled to quantify the magnitude of CNS changes in order to estimate this risk and to establish validity of the current permissible exposure limits (PELs). In addition, the impact of radiation exposure in combination with individual sensitivity or other space flight factors, as well as assessment of the need for biological/pharmaceutical countermeasures, will be considered after further definition of CNS risk occurs.

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

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.

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.

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

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

A biological approach to the interspecies prediction of radiation-induced mortality risk

International Nuclear Information System (INIS)

Carnes, B.A.; Grahn, D.; Olshansky, S.J.

1997-01-01

Evolutionary explanations for why sexually reproducing organisms grow old suggest that the forces of natural selection affect the ages when diseases occur that are subject to a genetic influence (referred to here as intrinsic diseases). When extended to the population level for a species, this logic leads to the general prediction that age-specific death rates from intrinsic causes should begin to rise as the force of selection wanes once the characteristic age of sexual maturity is attained. Results consistent with these predictions have been found for laboratory mice, beagles, and humans where, after adjusting for differences in life span, it was demonstrated that these species share a common age pattern of mortality for intrinsic causes of death. In quantitative models used to predict radiation-induced mortality, risks are often expressed as multiples of those observed in a control population. A control population, however, is an aging population. As such, mortality risks related to exposure must be interpreted relative to the age-specific risk of death associated with aging. Given the previous success in making interspecies predictions of age-related mortality, the purpose of this study was to determine whether radiation-induced mortality observed in one species could also be predicted quantitatively from a model used to describe the mortality consequences of exposure to radiation in a different species. Mortality data for B6CF 1 mice and beagles exposed to 60 Co γ-rays for the duration of life were used for analysis

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

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)

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

Progress in Space Weather Modeling and Observations Needed to Improve the Operational NAIRAS Model Aircraft Radiation Exposure Predictions

Science.gov (United States)

Mertens, C. J.; Kress, B. T.; Wiltberger, M. J.; Tobiska, W.; Xu, X.

2011-12-01

The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. During the development of the NAIRAS model, new science questions were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. Addressing these science questions require improvements in both space weather modeling and observations. The focus of this talk is to present these science questions, the proposed methodologies for addressing these science questions, and the anticipated improvements to the operational predictions of atmospheric radiation exposure. The overarching goal of this work is to provide a decision support tool for the aviation industry that will enable an optimal balance to be achieved between minimizing health risks to passengers and aircrew while simultaneously minimizing costs to the airline companies.

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.

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

Interest and limits of epidemiology for the evaluation of radiation induced cancer risks and the setting up of radiation protection standards

International Nuclear Information System (INIS)

Hubert, D.

1990-01-01

Epidemiological studies allow to confirm that a risk does exist for some types of cancer following high-dose exposures often at high dose-rates. However, no conclusion can be drawn for low doses and low dose-rates. Therefore we have to extrapolate from known high-dose risks to low doses and low dose-rates by various dose-response patterns. Another difficulty in assessing radiation cancer risks comes from the long latency time, which explains that all excess cancers have not yet been observed in the irradiated population studied. Once more, mathematical models are used to project excess lifetime cancer mortality. The estimations of radiation cancer risks are therefore marked by a great number of uncertainties, since they change accordingly to the model used. Other uncertainties come from the data, especially the dose estimates and are heightened when extrapolating to other populations. In 1988, UNSCEAR assessed new estimates for excess lifetime cancer mortality in the range of 4 to 11% per gray. These values mean a revaluation of the previous estimates by a 1.6 to 4.4 factor, which is mainly consecutive to the use of different projection models. Besides, they are solely based on the Hiroshima and Nagasaki survivors, whereas patient studies assess a lower risk. Finally UNSCEAR does not precisely state what is the available reduction factor to modify risks for low doses and low dose rates which should lie between 2 and 10. Due to a number of persistent uncertainties, we should not consider it justified to revise protection standards presently. 9 tabs.; 45 refs [fr

Interests and limits of epidemiology for the evaluation of risks of radiation induced cancer and the establishing of radiation protection standards

International Nuclear Information System (INIS)

Hubert, D.

1991-04-01

Epidemiological studies allow to confirm that a risk does exist for some types of cancer following high-dose exposures often at high dose-rates. However, no conclusion can be drawn for low doses and low dose-rates. Therefore we have to extrapolate from known high-dose risks to low doses and low dose-rates by various dose-response patterns. Another difficulty in assessing radiation cancer risks comes from the long latency time, which explains that all excess cancers have not yet been observed in the irradiated population studied. Once more, mathematical models are used to project excess lifetime cancer mortality. The estimations of radiation cancer risks are therefore marked by a great number of uncertainties, since they change accordingly to the model used. Other uncertainties come from the data, especially the dose estimates and are heightened when extrapolating to other populations. In 1988, UNSCEAR assessed new estimates for excess lifetime cancer mortality in the range of 4 to 11% per gray. These values mean a revaluation of the previous estimates by a 1.6 to 4.4 factor, which is mainly consecutive to the use of different projection models. Besides, they are solely based on the Hiroshima and Nagasaki survivors, whereas patient studies assess a lower risk. Finally UNSCEAR does not precisely state what is the available reduction factor to modify risks for low doses and low dose rates which should lie between 2 and 10. Due to a number of persistent uncertainties, we should not consider it justified to revise protection standards presently. (author)

Extrapolating ecological risks of ionizing radiation from individuals to populations to ecosystems

International Nuclear Information System (INIS)

Barnthouse, L.W.

1997-01-01

Approaches for protecting ecosystems from ionizing radiation are quite different from those used for protecting ecosystems from adverse effects of toxic chemicals. The methods used for chemicals are conceptually similar to those used to assess risks of chemicals to human health in that they focus on the protection of the most sensitive or most highly exposed individuals. The assumption is that if sensitive or maximally exposed species and life stages are protected, then ecosystems will be protected. Radiological protection standards, on the other hand, are explicitly premised on the assumption that organisms, populations and ecosystems all possess compensatory capabilities to allow them to survive in the face of unpredictable natural variation in their environments. These capabilities are assumed to persist in the face of at least some exposure to ionizing radiation. The prevailing approach to radiological protection was developed more than 30 years ago, at a time when the terms risk assessment and risk management were rarely used. The expert review approach used to derive radiological protection standards is widely perceived to be inconsistent with the open, participatory approach that prevails today for the regulation of toxic chemicals. The available data for environmental radionuclides vastly exceeds that available for any chemical. Therefore, given an understanding of dose-response relationships for radiation effects and exposures for individual organisms, it should be possible to develop methods for quantifying effects of radiation on populations. A tiered assessment scheme as well as available population models that could be used for the ecological risk assessment of radionuclides is presented. (author)

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)

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)

Space Radiation Cancer, Circulatory Disease and CNS Risks for Near Earth Asteroid and Mars Missions: Uncertainty Estimates for Never-Smokers

Science.gov (United States)

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

2011-01-01

The uncertainties in estimating the health risks from galactic cosmic rays (GCR) and solar particle events (SPE) are a major limitation to the length of space missions and the evaluation of potential risk mitigation approaches. NASA limits astronaut exposures to a 3% risk of exposure induced cancer death (REID), and protects against uncertainties in risks projections using an assessment of 95% confidence intervals after propagating the error from all model factors (environment and organ exposure, risk coefficients, dose-rate modifiers, and quality factors). Because there are potentially significant late mortality risks from diseases of the circulatory system and central nervous system (CNS) which are less well defined than cancer risks, the cancer REID limit is not necessarily conservative. In this report, we discuss estimates of lifetime risks from space radiation and new estimates of model uncertainties are described. The key updates to the NASA risk projection model are: 1) Revised values for low LET risk coefficients for tissue specific cancer incidence, with incidence rates transported to an average U.S. population to estimate the probability of Risk of Exposure Induced Cancer (REIC) and REID. 2) An analysis of smoking attributable cancer risks for never-smokers that shows significantly reduced lung cancer risk as well as overall cancer risks from radiation compared to risk estimated for the average U.S. population. 3) Derivation of track structure based quality functions depends on particle fluence, charge number, Z and kinetic energy, E. 4) The assignment of a smaller maximum in quality function for leukemia than for solid cancers. 5) The use of the ICRP tissue weights is shown to over-estimate cancer risks from SPEs by a factor of 2 or more. Summing cancer risks for each tissue is recommended as a more accurate approach to estimate SPE cancer risks. 6) Additional considerations on circulatory and CNS disease risks. Our analysis shows that an individual s

Calculating excess lifetime risk in relative risk models

International Nuclear Information System (INIS)

Vaeth, M.; Pierce, D.A.

1990-01-01

When assessing the impact of radiation exposure it is common practice to present the final conclusions in terms of excess lifetime cancer risk in a population exposed to a given dose. The present investigation is mainly a methodological study focusing on some of the major issues and uncertainties involved in calculating such excess lifetime risks and related risk projection methods. The age-constant relative risk model used in the recent analyses of the cancer mortality that was observed in the follow-up of the cohort of A-bomb survivors in Hiroshima and Nagasaki is used to describe the effect of the exposure on the cancer mortality. In this type of model the excess relative risk is constant in age-at-risk, but depends on the age-at-exposure. Calculation of excess lifetime risks usually requires rather complicated life-table computations. In this paper we propose a simple approximation to the excess lifetime risk; the validity of the approximation for low levels of exposure is justified empirically as well as theoretically. This approximation provides important guidance in understanding the influence of the various factors involved in risk projections. Among the further topics considered are the influence of a latent period, the additional problems involved in calculations of site-specific excess lifetime cancer risks, the consequences of a leveling off or a plateau in the excess relative risk, and the uncertainties involved in transferring results from one population to another. The main part of this study relates to the situation with a single, instantaneous exposure, but a brief discussion is also given of the problem with a continuous exposure at a low-dose rate

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.

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.

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.

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

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.

Application of Improved Radiation Modeling to General Circulation Models

Energy Technology Data Exchange (ETDEWEB)

Michael J Iacono

2011-04-07

This research has accomplished its primary objectives of developing accurate and efficient radiation codes, validating them with measurements and higher resolution models, and providing these advancements to the global modeling community to enhance the treatment of cloud and radiative processes in weather and climate prediction models. A critical component of this research has been the development of the longwave and shortwave broadband radiative transfer code for general circulation model (GCM) applications, RRTMG, which is based on the single-column reference code, RRTM, also developed at AER. RRTMG is a rigorously tested radiation model that retains a considerable level of accuracy relative to higher resolution models and measurements despite the performance enhancements that have made it possible to apply this radiation code successfully to global dynamical models. This model includes the radiative effects of all significant atmospheric gases, and it treats the absorption and scattering from liquid and ice clouds and aerosols. RRTMG also includes a statistical technique for representing small-scale cloud variability, such as cloud fraction and the vertical overlap of clouds, which has been shown to improve cloud radiative forcing in global models. This development approach has provided a direct link from observations to the enhanced radiative transfer provided by RRTMG for application to GCMs. Recent comparison of existing climate model radiation codes with high resolution models has documented the improved radiative forcing capability provided by RRTMG, especially at the surface, relative to other GCM radiation models. Due to its high accuracy, its connection to observations, and its computational efficiency, RRTMG has been implemented operationally in many national and international dynamical models to provide validated radiative transfer for improving weather forecasts and enhancing the prediction of global climate change.

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)

Chemical and radiation environmental risk management at the crossroads: Case studies

International Nuclear Information System (INIS)

Tran, N.; Burke, T.; Locke, P.

1999-01-01

Although many of the major environmental risk management decisions we face today require the simultaneous evaluation and control of both radiological and chemical risks, the separation of radiation and chemical risk management persists along legal, regulatory, programmatic, training and professional practice levels. In June 1998, a panel of 40 chemical and radiation risk experts met at an interactive workshop entitled 'Addressing the Similarities and Differences in Chemical and Radiation Environmental Risk Management,' in Annapolis, Maryland to discuss several perspectives on harmonizing chemical and radiation risk management approaches. At the conclusion of the meeting, workshop participants recommended that case studies of clean-up sites at which radioactive materials and hazardous chemical risks were addressed, be developed to help educate participants in the harmonization dialogue about their counterpart's issues, stimulate discussion and sharpen issues in a way that they can be resolved. Several key risk management issues that were highlighted from the discussion at the Annapolis meeting are being evaluated in the case studies. They include: decision criteria, costs and public/stakeholder input. This paper presents these key issues and the approach taken in the case studies. (author)

An overview of measuring and modelling dose and risk from ionising radiation for medical exposures