WorldWideScience

Sample records for low-level radiation exposure

  1. Human exposure to low level ionising radiation

    International Nuclear Information System (INIS)

    Paix, David

    1988-01-01

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

  2. Effects of high vs low-level radiation exposure

    International Nuclear Information System (INIS)

    Bond, V.P.

    1983-01-01

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

  3. Assessing risks from occupational exposure to low-level radiation

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1989-06-01

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

  4. Health effects of low level radiation exposure among radiation workers

    International Nuclear Information System (INIS)

    Murata, Motoi

    2003-01-01

    In Japan, a cohort study of radiation workers has been conducted since 1990. The cohort population consisted of about 176,000 workers (mostly males) who had been registered in the centralized radiation dose registry system and engaged in various radiation works at nuclear facilities. Statistical analyses were performed mainly on the 2,934 deaths, of which 1,191 were cancer cases, detected among 119,000 male subjects during the prospective follow-up. The standardized mortality ratio showed that for any cancers mortality was not different between this population and Japanese general population. By the trend test, though significantly increasing trend in accord with increasing doses was not observed for both cancer in all sites and leukemia, it was highly significant for esophagus cancer and external causes of deaths. Results of the questionnaire survey study of lifestyle of radiation workers suggested that increasing trend of these diseases was at least partly due to the influence of some confounding factors. As a result of reviewing published studies, including the present work, trend of mortality from cancer in all sites with increasing doses seems still unclear, whereas for leukemia it appears to stay flat under 100 mSv but rapidly rise up in the doses higher than this as if fitting to either a linear-quadratic or threshold models. (author)

  5. Regulatory control of low level radiation exposure in Tanzania

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  6. Overview of the hazards of low-level exposure to radiation

    International Nuclear Information System (INIS)

    Ritenour, E.R.

    1984-01-01

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

  7. Childhood cancer after low-level intrauterine exposure to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wakeford, Richard [BNFL, Risley, Warrington, Cheshire (United Kingdom)]. E-mail: R.Wakeford@bnfl.com; Little, Mark P. [Department of Epidemiology and Public Health, Imperial College of Science, Technology and Medicine, London (United Kingdom)

    2002-09-01

    Case-control studies of childhood cancer and foetal exposure to diagnostic x-rays suggest that doses as small as 10 mSv increase the risk of cancer to a detectable extent. A comparison of the risk coefficient derived from the largest such study with that obtained from the Japanese atomic bomb survivors irradiated in utero (average dose, {approx}300 mGy) shows that, once all sources of uncertainty are taken into account, these risk estimates are not incompatible. The absence of a discernible variation in the risk per unit dose over this dose range is consistent with a linear dose-response. However, uncertainties are such that definitive conclusions on the shape of the dose-response at low doses cannot be drawn from this epidemiological evidence alone. Nonetheless, the evidence does suggest that the risk is not zero at doses of the order of 10 mSv. (author)

  8. Low-level radiation

    International Nuclear Information System (INIS)

    Myers, D.K.

    1982-05-01

    It is known that the normal incidence of cancer in human populations is increased by exposure to moderately high doses of ionizing radiation. At background radiation levels or at radiation levels which are 100 times greater, the potential health risks are considered to be directly proportional to the total accumulated dose of radiation. Some of the uncertainties associated with this assumption and with the accepted risk estimates have been critically reviewed in this document. The general scientific consensus at present suggests that the accepted risk estimates may exaggerate the actual risk of low levels of sparsely ionizing radiations (beta-, gamma- or X-rays) somewhat but are unlikely to overestimate the actual risks of densely ionizing radiations (fast neutrons, alpha-particles). At the maximum permissible levels of exposure for radiation workers in nuclear power stations, the potential health hazards in terms of life expectancy would be comparable to those encountered in transportation and public utilities or in the construction industry. At the average radiation exposures received by these workers in practice, the potential health hazards are similar to those associated with safe categories of industries. Uranium mining remains a relativly hazardous occupation. In terms of absolute numbers, the genetic hazards, which are less well established, are thought to be smaller than the carcinogenic hazards of radiation when only the first generation is considered but to be of the same order of magnitude as the carcinogenic hazards when the total number of induced genetic disorders is summed over all generations

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

    International Nuclear Information System (INIS)

    Deniz, Dalji

    2006-01-01

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

  10. Epidemiological methods of assessing risks from low level occupational exposure to ionising radiation

    International Nuclear Information System (INIS)

    Reissland, J.A.

    1982-01-01

    The resolution of radiation-attributable malignancies from the background of malignancies which are responsible for about 20% of all deaths in the Western world, presents a formidable challenge to epidemiological methods. Some of the major difficulties facing those with the task of estimating the risks associated with exposure to low level ionising radiation are discussed, particularly in the context of radiological protection. Some of the studies currently in progress are summarised and suggestions are made for other work which may help to contribute to a better understanding of the quantitative aspects of radiation risk assessment. (author)

  11. Limitations and problems in deriving risk estimates for low-level radiation exposure

    International Nuclear Information System (INIS)

    Cohen, B.L.

    1981-01-01

    Some of the problems in determining the cancer risk of low-level radiation from studies of exposed groups are reviewed and applied to the study of Hanford workers by Mancuso, Stewart, and Kneale. Problems considered are statistical limitations, variation of cancer rates with geography and race, the ''healthy worker effect,'' calendar year and age variation of cancer mortality, choosing from long lists, use of proportional mortality rates, cigarette smoking-cancer correlations, use of averages to represent data distributions, ignoring other data, and correlations between radiation exposure and other factors that may cause cancer. The current status of studies of the Hanford workers is reviewed

  12. Legal recourse for damages suffered from low-level radiation exposure

    International Nuclear Information System (INIS)

    Pesto-Edwards, M.M.

    1984-01-01

    In the past few years several events involving toxic substances have received widespread coverage by the media, thereby altering an already aware population to the hazards of exposure to toxic agents. Incidents such as Three Mile Islane, Love Canal, and Hemlock, Michigan, the exposure plight of veterans to radiation at the Nevada Test Site and to Agent Orange in Vietnam, and to the exposure of factory workers to asbestos, have been highly publicized. In part because of this publicity, the emphasis of the 1970's on controlling water and air pollution has been shifting slowly during the 1980s to the of control of hazardous waste pollution. Despite this shifting emphasis, legislative and judicial systems have been slow to respond. Few remedies are available to real and imagined victims of toxic substances. From a legal point of view, there is little difference between exposure to low levels of radiation and low levels of toxic chemicals. Both instances fall under the broader domain of environmental law. Depending on the circumstances, one instance might provide legal precedent for the other. This chapter presents examples drawn from both areas in order to illustrate current issues. The discussion is divided into four parts: (1) the common law tort theories that may be asserted when a plaintiff has suffered injury resulting from exposure to low-level radiation or other toxic substances; (2) the difficulties posed by the relief mechanisms rooted in traditional common law; (3) current federal legislation, along with its merits and shortcomings; and (4) solutions to the obstacles now faced by plaintiffs in attempting to recover their damages. Also discussed are suggested judicial and legislative solutions designed to remedy the damages caused to persons exposed to toxic wastes

  13. Case-control study of congenital malformations and occupational exposure to low-level ionizing radiation

    International Nuclear Information System (INIS)

    Sever, L.E.; Gilbert, E.S.; Hessol, N.A.; McIntyre, J.M.

    1988-01-01

    In a case-control study, the authors investigated the association of parental occupational exposure to low-level external whole-body penetrating ionizing radiation and risk of congenital malformations in their offspring. Cases and controls were ascertained from births in two counties in southeastern Washington State, where the Hanford Site has been a major employer. A unique feature of this study was the linking of quantitative individual measurement of external whole-body penetrating ionizing radiation exposure of employees at the Hanford Site, using personal dosimeters, and the disease outcome, congenital malformations. The study population included 672 malformation cases and 977 matched controls from births occurring from 1957 through 1980. Twelve specific malformation types were analyzed for evidence of association with employment of the parents at Hanford and with occupational exposure to ionizing radiation. Two defects, congenital dislocation of the hip and tracheoesophageal fistula, showed statistically significant associations with employment of the parents at Hanford, but not with parental radiation exposure. Neural tube defects showed a significant association with parental preconception exposure, on the basis of a small number of cases. Eleven other defects, including Down syndrome, for which an association with radiation was considered most likely, showed no evidence of such an association. When all malformations were analyzed as a group, there was no evidence of an association with employment of the parents at Hanford, but the relation of parental exposure to radiation before conception was in the positive direction (one-tailed p value between 0.05 and 0.10). Given the number of statistical tests conducted, some or all of the observed positive correlations are likely to represent false positive findings. 30 references

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

    International Nuclear Information System (INIS)

    Kant, Krishan

    2012-01-01

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

  15. HELLE: Health Effects of Low Level Exposures/ Gezondheidseffecten van lage blootstellingniveaus [International workshop: Influence of low level exposures to chemicals and radiation on human and ecological health

    Energy Technology Data Exchange (ETDEWEB)

    Schoten, Eert

    1998-11-26

    The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits centers around the appropriateness of extrapolation methods (What can be inferred from data on high exposure levels and on experimental animals?). Generally speaking, there is a lack of direct information on the health effects of low levels of exposure. Effects at these levels cannot usually be detected by means of traditional animal experiments or epidemiological research. The capacity of these analytical instruments to distinguish between ''signal'' and ''noise'' is inadequate in most cases. Annex B of this report contains a brief outline of the difficulties and the established methods for tackling this problem. In spite of this, the hope exists that the posited weak signals, if they are indeed present, can be detected by other means. The search will have to take place on a deeper level. In other words, effort must be made to discover what occurs at underlying levels of biological organization when organisms are exposed to low doses of radiation or substances. Molecular and cell biology provide various methods and techniques which give an insight into the processes within the cell. This results in an increase in the knowledge about the molecular and cellular effects of exposure to agents, or stated differently, the working mechanisms which form the basis of the health effects. Last year, the Health Council considered that the time was ripe to take stock of the state of knowledge in this field. To this end, an international working conference was held from 19 to 21 October 1997, entitled ''Health Effects of

  16. Monitoring of low level environmental gamma exposure by the centralized radiation monitoring system

    International Nuclear Information System (INIS)

    Katagiri, Hiroshi; Kobayashi, Hideo; Obata, Kazuichi; Kokubu, Morinobu; Itoh, Naoji

    1981-07-01

    In the Japan Atomic Energy Research Institute (JAERI), a centralized automatic radiation monitoring system developed 20 years ago has recently been improved to monitor low level gamma radiation more accurately in normal operation of the nuclear facilities and to detect abnormal radioactive releases more effectively. The present state of the system is described. This system puts together environmental monitoring data such as gamma exposure rate (20 points), radioactive concentration in the air (4 points) and in water (2 drains), and meteorological items (14 including wind directions, wind speeds, solar radiation and air temperatures at a observation tower of 40 m height). Environmental monitoring around the JAERI site is carried out effectively using the system. Data processing system consists of a central processing unit, a magnetic disk, a magnetic tape, a line printer and a console typewriter. The data at respective monitoring points are transmitted to the central monitoring room by wireless or telephone line. All data are printed out and field in magnetic disk and magnetic tape every 10 minutes. When the emergency levels are exceeded, however, the data are automatically output on a line printer every 2 minute. This system can distinguish very low gamma exposure due to gaseous effluents, about 1 mR/y, from the background. Even in monthly exposures, calculated values based on the data of release amount and meteorology are in good agreement with the measured ones. (author)

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  18. Radiation and health: low-level-ionizing radiation exposure and effects

    International Nuclear Information System (INIS)

    Kant, Krishan

    2013-01-01

    In the present paper, brief review of the available literature, data and reports of various radiation exposure and protection studies is presented. An in-depth analysis of reports available suggests that the possible beneficial outcomes of exposure to LLIR are: increased Growth rate, Development, Neurogenesis, Memory, Fecundity (Fertility), Immunity (Resistance to diseases due to large doses of radiation) and Lifespan (Longevity) Decreased Cancer deaths, Cardiovascular deaths, Respiratory deaths, Neonatal deaths, Sterility, Infection, Premature deaths. The findings also suggest that the LNT theory is overly stated for assessing carcinogenic risks at low doses. It is not scientifically justified and should be banned as it creates radio phobia thereby blocking the efforts to supply reliable, environmentally friendly nuclear energy and important medical therapies. There is no need for anyone to live in fear of serious health consequences from the radioactivity that comes out from nuclear installations and exposures in the range of background radiation. A linear quadratic model has been given illustrating the validity of radiation hormesis, besides the comparison of the dose rates arising from natural and manmade sources to Indian population

  19. Conceptual basis for evaluating risk from low-level radiation exposure

    International Nuclear Information System (INIS)

    Bond, V.P.

    1981-01-01

    Serious or lethal injuries that may result from the exposure of animals or human beings to ionizing radiations can be divided into two distinctly different categories, on the basis of whether the injury results only from failure of an entire vital organ, or stems from impairment of the function of a single cell. These two categories of injury are termed here organ effects, normally induced by non-stochastic processes, and single cell effects, normally induced by stochastic processes. This presentation is limited to low-level radiation exposure (LLR) since: (1) only with single hit kinetics does the average number of cell doses per cell in the exposed population essentially equal the number of cells dosed; (2) in excluding multihit all-or-none effects, the functions developed are essentially independent of the time rate at which the (instantaneously deposited) cell doses are laid down, and of considerations of repair of sub-effect injury; and (3) it makes little or no difference with LLR if the incidence of single cell effects is expressed in terms of exposed or surviving cells

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

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1992-06-01

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

  1. Low level radiation: biological effects

    International Nuclear Information System (INIS)

    Loken, M.K.

    1983-01-01

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

  2. Exposure to low levels of ionizing radiation and lung cancer risk in Florida

    International Nuclear Information System (INIS)

    Stockwell, H.G.; Lyman, G.H.; Waltz, J.

    1986-01-01

    The phosphate deposits of central Florida contain levels of uranium and its daughter products 30-60 times greater than average soils. A case-control study was conducted to assess the risk of lung cancer associated with living on these phosphateic soils. Using the records of the state-wide Florida Cancer Data System to address this issue, all cases of lung cancer among Florida residents in 1981 were identified (n = 7049). Information was obtained regarding residence, age, sex, race, and smoking habits. Controls consisted of 6643 individuals with cancers of the colon or rectum. Residents of the central Florida phosphate region experienced a significant increase in lung cancer risk compared to other Florida residents (odds ratio (OR) = 1.4). Excess risks appeared concentrated among squamous cell cancer (OR = 1.6) and small cell cancer (OR = 1.6). When smoking habits as well as residential area was considered, no significant excess risk, associated with residence, was observed among nonsmokers or light smokers. Area residents smoking a pack or more per day experienced a 70% increase in lung cancer risk compared to individuals smoking a similar amount but living elsewhere. Highest risks were observed among persons with squamous cell cancer (OR = 2.1) and small cell cancer (OR = 2.5) who smoked more than 40 cigarettes a day. Results suggest exposure to low levels of ionizing radiation increases the lung cancer risk of residents of this area

  3. Tritium: a model for low level long-term ionizing radiation exposure

    International Nuclear Information System (INIS)

    Carsten, A.L.

    1984-01-01

    The somatic, cytogenetic and genetic effects of single and chronic tritiated water (HTO) ingestion in mice was investigated. This study serves not only as an evaluation of tritium toxicity (TRITOX) but due to its design involving long-term low concentration ingestion of HTO may serve as a model for low level long-term ionizing radiation exposure in general. Long-term studies involved animals maintained on HTO at concentrations of 0.3 μCi/ml, 1.0 μCi/ml, 3.0 μCi/ml or depth dose equivalent chronic external exposures to 137 Cs gamma rays. Maintenance on 3.0 μCi/ml resulted in no effect on growth, life-time shortening or bone marrow cellularity, but did result in a reduction of bone marrow stem cells, an increase in DLM's in second generation animals maintained on this regimen and cytogenetic effects as indicated by increased sister chromatid exchanges (SCE's) in bone marrow cells, increased chromosome aberrations in the regenerating liver and an increase in micronuclei in red blood cells. Biochemical and microdosimetry studies showed that animals placed on the HTO regimen reached tritium equilibrium in the body water in approximately 17 to 21 days with a more gradual increase in bound tritium. When animals maintained for 180 days on 3.0 μCi/ml HTO were placed on a tap water regimen, the tritium level in tissue dropped from the equilibrium value of 2.02 μCi/ml before withdrawal to 0.001 μCi/ml at 28 days. 18 references

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

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1982-04-01

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

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

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1982-04-01

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

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

    International Nuclear Information System (INIS)

    Goodhead, D. T.

    2009-01-01

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

  7. Radiation in complex exposure situations. Assessing health risks at low levels from concomitant exposures to radiation and chemicals

    International Nuclear Information System (INIS)

    Hornhardt, S.; Jung, T.; Burkart, W.

    2000-01-01

    Health effects from exposures to ionizing radiation are in general the result of complex multi-step reaction chains involving changes and responses on the level of molecules, cells, tissues and organisms. In environmental low dose exposure situations ionizing radiation only contributes a small fraction to the life-long attack on DNA by other exogenous and endogenous genotoxins. Nevertheless, efforts to assess and quantify deleterious effects at low exposure levels are directed mainly towards radiation as a single isolated agent, and rarely towards the concomitant presence of other natural and anthropogenic toxicants. Only these combined exposures may lead to observable health risk effects. In addition they might differ from those expected from simple addition of the individual risks due to interaction. The existing data base on combined effects is rudimentary, mainly descriptive and rarely covers exposure ranges large enough to make direct inferences to present day low dose exposure situations. Therefore, any risk assessment will have to consider the question whether combined effects, i.e. interaction between two or more agents will influence the health outcome from specific exposure situations in such a way that predictions derived from simple standard exposure situations would have to be revised. In view of the multitude of possible interactions between the large number of potentially harmful agents in the human environment, descriptive approaches will have to be supplemented by the use of mechanistic models for critical health endpoints such as cancer. Agents will have to be grouped depending on their physical or chemical mode of action at the molecular and cellular level, to generalize and predict the outcome of combined exposures at low exposure levels and the possibility of interactions. (author)

  8. Epidemiological survey of radiation workers. Risk of leukemia and solid cancer by low level radiation exposure

    International Nuclear Information System (INIS)

    Tatsumi, Kouichi

    2011-01-01

    An interim report on the epidemiological survey of cohort involving radiation workers in the nuclear power plants in Japan was introduced. It consists of eight chapters such as introduction, the objects of mortality rate survey from death causes and creating a cohort, the method of tracking the life and death, analytical methods of mortality rate, analytical results, confounded effects of life style, discussion: contrast the report on the mortality rate of solid cancer except leukemia in Japan and other countries and the conclusions. The subjects of mortality rate of the forth survey were about 277,000 workers including from the first to the third survey. In a prospective cohort study, 203,904 workers were screened for analytical study, and they included 14,224 deaths (5,711 from malignant neoplasm, 6,310 from nonmalignant neoplasm and 1,995 from extrinsic death). The analytical results were shown by three types of death caused from leukemia, malignant neoplasm except for leukemia and nonmalignant neoplasm. Analytical results of the mortality rate from death caused in third and forth study, change of analytical results from the first to the forth observation period were illustrated. (S.Y.)

  9. The risk of childhood leukaemia from low-level radiation exposure

    International Nuclear Information System (INIS)

    Wakeford, R.; Binks, K.; Slovak, A.J.M.

    1992-01-01

    Exposure to ionizing radiation is an established cause of leukemia in childhood ( -5 excess childhood leukemia cases per mSv for fetal exposure, around 1.5 x 10 -5 excess childhood leukemia cases per mSv for irradiation in early infancy, this latter risk coefficient reducing with advancing age at exposure . The closeness of the risk coefficients for exposure just before and after birth (derived from different sources of information) is reassuring. It is these coefficients that are used in assessing the risk of childhood leukemia due to, say, the operation of a nuclear facility, and such assessments have demonstrated that the risk due to normal operations will produce a very small number of extra cases, a 'signal' that will not be detectable above the unavoidable 'noise' of statistical fluctuations in background incidence rates . However, reports of childhood leukemia 'clusters' near certain nuclear installations in Britain have led to the accuracy of these assessments being challenged. (author)

  10. A trial epidemiological study on health effects of long term and low level radiation exposure

    International Nuclear Information System (INIS)

    Hattori, Yoshiaki; Maeda, Kazuho

    1980-01-01

    As a trial evaluation of applicability of multivariate model in an analysis of health effects of radiation workers, the multiple logistic function method was applied to the data of occupational exposure record and long term absence record obtained from 593 employees of two institutions both of which practice R and D relating nuclear power. In order to estimate parameters of multiple logistic function by maximum likelihood method, followings were defined as variables: age, length of employment and cumulative exposure dose of radiation as independent variables, and the fact that whether the individual worker had the experience of absence lasting more than a week or not as a dependent variable. As the results, due to shortage of amount of data, only the age of workers shows a significant relationship with the absence data, the other variables do not have any significant results in the association with absence. In this preliminary trial, the applicability of multiple logistic function model in risk estimation of long term occupational exposure was not clearly demonstrated because of data shortage. To testify the applicability, further investigations will be needed, accumulating plenty of data concerning exposure and health effects. (author)

  11. Progressive behavioral changes in rats after exposure to low levels of ionizing radiation in utero

    International Nuclear Information System (INIS)

    Norton, S.; Kimler, B.F.; Mullenix, P.J.

    1991-01-01

    The deleterious effects of ionizing radiation on the developing brain may be not only prolonged but progressive. Fetuses were exposed to 0.75 Gy of ionizing radiation on gestational day 15 through whole body exposure of the pregnant rat. Three behavioral tests (gait analysis, continuous corridor activity and photographic analysis of sequences of behavioral acts) were performed at 1 and 3 months, postnatally. Body weight and thickness of the cerebral cortex of irradiated rats were 10-15 percent below controls throughout the period of study. Behavior in all tests was more affected at 3 months than at 1 month of age. Gait of control rats, as measured by the angle of advanced of hind feet, widened about 20 percent for males and 40 percent for females from 1 to 3 months, as expected, while, in irradiated rats, the angle widened only about 10 percent. Continuous corridor activity increased less than 10 percent in controls and about 35 percent in irradiated rats over the same period. In photographic analysis of behavior, controls increased their time spent standing by about 50 percent in males and 20 percent in females from 1 to 3 months of age. Irradiated males increased time standing only about 10 percent and irradiated females decreased about 30 percent over the same period. The data obtained in these experiments support other evidence that some behavioral alterations from perinatal exposure to radiation become more marked with maturation

  12. Cytogenetic damage at low doses and the problem of bioindication of chronic low level radiation exposure

    International Nuclear Information System (INIS)

    Geras'kin, S.A.; Dikarev, V.G.; Nesterov, E.B.; Vasiliev, D.V.; Dikareva, N.S.

    2000-01-01

    The analysis undertaken by us of the experimentally observed cellular responses to low dose irradiation has shown that the relationship between the yield of induced cytogenetic damage and radiation dose within low dose range is non-linear and universal in character. Because of the relationship between the yield of cytogenetic damage and dose within low dose range is non-linear, the aberration frequency cannot be used in biological dosimetry in the most important in terms of practical application case. The cytogenetic damage frequency cannot be used in biological dosimetry also because of the probability of synergistic and antagonistic interaction effects of the different nature factors simultaneously acting on test-object in real conditions is high within low dose (concentration) range. In our experimental study of the regularities in the yield of structural mutations in conditions of combined influence of ionizing radiation, heavy metals and pesticides it was found that synergistic and antagonistic effects are mainly induced in conditions of combined action of low exposure injuring agents. Experiments on agricultural plants were carried out in 1986-1989 at the 30-km zone around Chernobyl NPP. It was shown that chronic low dose exposure could cause an inheritable destabilization of genetic structures expressing in increase of cytogenetic damage and yield karyotypic variability in offspring's of irradiated organisms. Obviously exactly this circumstance is the reason of the phenomenon found in our researches of significant time delay of cytogenetic damage reduction rate from radioactive pollution reduction rate from time past from the accident moment. Research of cytogenetic damage of reproductive (seeds) and vegetative (needles) plant organs of the Pinus sylvestris tree micropopulations growing in contrast by radioactive pollution level sites of the 30-km ChNPP zone and also in the vicinity of the industrial plant > for processing and temporary storage of

  13. Long-term effects of low-level radiation exposure, experimental studies

    International Nuclear Information System (INIS)

    Bond, V.P.

    1978-05-01

    Important considerations in the quantitative estimate of risk of carcinogenesis in the human being are the related factors of the shape of the dose-effect curve, the risk per rad at very low doses (about 10 rad or less) vs. higher doses, and the effect per rad of higher doses delivered at very low dose rates. Data on the human being, though extensive and adequate for quantitative risk estimation at high doses and dose rates, do not allow definitive conclusions on these factors. Data on eukaryotic cells are represented well and in detail by a modified quadratic relationship with a definite linear term, and indicate that both the simple linear and the pure quadratic relationships are rare or essentially nonexistent. A dose rate effect is ubiquitous, but the extent varies widely among different tumors and species. Extensive data on carcinogenesis in mammals are in general represented well by the linear-quadratic model, although simple linearity and the pure quadratic (or threshold) models cannot be excluded in a few tumor systems. Considerations and uncertainties in addition to curve shape and dose rate may tend to offset any credit that might be afforded by dose rate. Hence, while it is almost certain that dose rate does at least to some degree affect (reduce) the current risk estimated based on linearity, it also seems clear that, at least for some time, current carcinogenesis risk estimates based on linearity probably will continue to be used as an approximation of the degree of risk associated with radiation exposure at very low doses and dose rates

  14. Evaluation of Radiation Exposure during Construction and Operation of Concrete Bridge Reinforced with Very Low Level Radioactive Steel

    International Nuclear Information System (INIS)

    Panik, M.; Necas, V.

    2012-01-01

    A lot of nuclear power plants are approaching the end of their lifetime and they will be phased out. Decommissioning of these nuclear power plants involve complete dismantling of technologies and demolition of buildings. During this process it is produced plenty of waste material of different categories. Significant portion of decommissioning materials comprise radionuclides what is caused by contamination and activation processes mostly from the operational period of nuclear power plant. Attention in this paper is paid to waste steel from the decommissioning of nuclear power plants with the specific activity just slightly exceeding legislation limits for the unconditional release into the environment. From the traditional point of view this material should be treated, conditioned and disposed on the radioactive waste repository. Second possibility is to release this material conditionally and reuse it in chosen industrial application. Very low level radioactive steel scrap should be melted and melting products should be processed into products that can be applied in industry. First option requires considerable financial investment, human resources and repository capacity. Second option saves some financial funds and it enables to reuse and save potentially valuable material for the future. Paper comprises evaluation of external and internal exposure during construction and operation of concrete bridges that utilize very low level radioactive steel as part of their reinforcement. Two models of representative concrete bridges were created. External gamma exposure and exposure from inhalation and ingestion of radionuclides were calculated using suitable computational tools. VISIPLAN 3D ALARA planning tool was chosen for the calculation of external gamma exposure. Software GOLDSIM enables to calculate transport of radionuclides initially contained in conditionally released reinforcement steel through subsoil and sequential exposure of people caused by inhalation of

  15. Effects of Low Level Radiation exposure on Neurogenesis and Cognitive Function: Mechanisms and Prevention

    Science.gov (United States)

    2005-09-01

    1 mental model in the old rat. Int. J. Radiat. Oncol. Biol. Phys., 31: 65-70, 1995. give rise to new nerons in the adult mammalian hippocampus. I...Morris water maze localized within a network , could significantly increase the and white noise and bright light used to motivate escape complexity and...irradiation. However, we cannot ex- can be incorporated into the hippocampal networks and/or elude the possibility that a more challenging version of the

  16. Impact of chronic, low-level ionising radiation exposure on terrestrial invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Hingston, J.; Wood, M.D.; Copplestone, D.; Zinger, I. [Liverpool Univ., School of Biological Sciences, Merseyside (United Kingdom)

    2004-07-01

    There is a need to confirm that the environment is being adequately protected from the mixture of contaminants released into it. In the field of environmental radioactivity, tools have been developed to assess the impacts of ionising radiation on wildlife. The scientific data upon which these assessments are based is, however, lacking. New documentation has been produced by the UK Environment Agency to provide guidelines on structuring experiments (using environmentally relevant doses) and select suitable non-human species and endpoints for study. It is anticipated that this documentation will be used to direct future experiments in this field. This paper presents the results of the first of these experiments. Numbers of the earthworm Eisenia fetida and the wood louse Porcellio scaber were segregated and constantly exposed to one of six radiation doses (background, 0.1, 0.4, 1.5, 4.0 and 8.0 mGyh{sup -1}) for a total of 16 and 14 weeks respectively. The endpoints of mortality, number of viable offspring and average weight of an individual were recorded and the results of this study will be discussed here. (author)

  17. 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

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

    International Nuclear Information System (INIS)

    Masse, Roland

    2014-06-01

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

  19. Can low-level radiation cause cancer?

    International Nuclear Information System (INIS)

    Trosko, J.E.

    1995-01-01

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

  20. Effect of Short-term 900 MHz low level electromagnetic radiation exposure on blood serotonin and glutamate levels.

    Science.gov (United States)

    Eris, A H; Kiziltan, H S; Meral, I; Genc, H; Trabzon, M; Seyithanoglu, H; Yagci, B; Uysal, O

    2015-01-01

    Long term exposure to low level electromagnetic radiation (LLER) by using cellular phones causes serious health problems. Ten male Wistar Albino rats were anesthetized 30 min before the LLER exposure, 0.5 ml blood was taken from the tail vein of rats in order to determine control values. Rats were grouped by three and placed on a plexi-glass flat. A fixed equivalent frequency emitter device was used. A sign to be an electromagnetic field 15.14 V/m (608 mW/m(2)) in strength in the head region with 100 kHz FM modulation at 900 MHz was applied to the animals. After calculating the ideal position for the device, electromagnetic LLER energy was applied for 45 minutes from a distance to be equal with energy transmitted by a mobile phone from a 0.5-1 cm distance to their head regions. After 1.5 hours and before the rats awoke, 0.5 ml of blood was taken from the tail veins in order to determine the treatment values. Plasma 5-HT and glutamate levels were measured by enzyme immunoassay (EIA) using commercial kits. It was found that a single 45 min of LLER exposure increased the blood 5-HT level significantly, but did not change the glutamate level of rats. It was concluded that even a single 45 min of LLER exposure may produce an increase in 5-HT level without changing the blood glutamate level. Increased 5-HT level may lead to a retarded learning and a deficit in spatial memory (Tab. 2, Fig. 2, Ref. 24).

  1. Health effects of low level radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hattori, Sadao [Central Research Inst. of Electric Power Industry, Tokyo (Japan)

    1998-12-31

    In 1982, Prof. Thomas Don Luckey of Missouri Univ. asserted `Radiation Hormesis` on the Journal of Health Physics and he published two books. CRIEPI initiated the research program on Radiation Hormesis following his assertion to confirm `is it true or not?` After nearly ten year research activities on data surveys and animal tests with many Universities, we are realizing scientific truth of bio-positive effects by low level radiation exposures. The interesting bio-positive effects we found could be categorized in following five groups. 1) Rejuvenation of cells such as increase of SOD and cell membrane permeability, 2) Moderation of psychological stress through response of key enzymes, 3) Suppression and therapy of adult-diseases such as diabetes and hypertension, 4) Suppression of cancer through enhancement of immune systems such as lymphocytes, 5) Suppression of cancer and ratio-adaptive response by activation of DNA repair and apoptosis. In the responses of many specialists to our initiation of radiation hormesis research program following T.D. Luckey`s claim about low level radiation, I have to pick up for the first, the great success of Prof. Sakamoto. Prof. Sakamoto had been already applying whole body low dose irradiation for ten years before our radiation hormesis research started on the therapy to suppress the cancer reappearing after treatment. He reported about his successful trial to real patients and showed an enhancement of immune system. (author)

  2. Health effects of low level radiation

    International Nuclear Information System (INIS)

    Hattori, Sadao

    1998-01-01

    In 1982, Prof. Thomas Don Luckey of Missouri Univ. asserted 'Radiation Hormesis' on the Journal of Health Physics and he published two books. CRIEPI initiated the research program on Radiation Hormesis following his assertion to confirm 'is it true or not?' After nearly ten year research activities on data surveys and animal tests with many Universities, we are realizing scientific truth of bio-positive effects by low level radiation exposures. The interesting bio-positive effects we found could be categorized in following five groups. 1) Rejuvenation of cells such as increase of SOD and cell membrane permeability, 2) Moderation of psychological stress through response of key enzymes, 3) Suppression and therapy of adult-diseases such as diabetes and hypertension, 4) Suppression of cancer through enhancement of immune systems such as lymphocytes, 5) Suppression of cancer and ratio-adaptive response by activation of DNA repair and apoptosis. In the responses of many specialists to our initiation of radiation hormesis research program following T.D. Luckey's claim about low level radiation, I have to pick up for the first, the great success of Prof. Sakamoto. Prof. Sakamoto had been already applying whole body low dose irradiation for ten years before our radiation hormesis research started on the therapy to suppress the cancer reappearing after treatment. He reported about his successful trial to real patients and showed an enhancement of immune system. (author)

  3. HELLE: Health Effects of Low Level Exposures

    International Nuclear Information System (INIS)

    Schoten, Eert

    1998-01-01

    The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits centers around the appropriateness of extrapolation methods (What can be inferred from data on high exposure levels and on experimental animals?). Generally speaking, there is a lack of direct information on the health effects of low levels of exposure. Effects at these levels cannot usually be detected by means of traditional animal experiments or epidemiological research. The capacity of these analytical instruments to distinguish between ''signal'' and ''noise'' is inadequate in most cases. Annex B of this report contains a brief outline of the difficulties and the established methods for tackling this problem. In spite of this, the hope exists that the posited weak signals, if they are indeed present, can be detected by other means. The search will have to take place on a deeper level. In other words, effort must be made to discover what occurs at underlying levels of biological organization when organisms are exposed to low doses of radiation or substances. Molecular and cell biology provide various methods and techniques which give an insight into the processes within the cell. This results in an increase in the knowledge about the molecular and cellular effects of exposure to agents, or stated differently, the working mechanisms which form the basis of the health effects. Last year, the Health Council considered that the time was ripe to take stock of the state of knowledge in this field. To this end, an international working conference was held from 19 to 21 October 1997, entitled ''Health Effects of Low Level Exposures: Scientific Developments and

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

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1982-06-01

    The quantitative estimation of the carcinogenic risk of low-dose, high-LET radiation in the case of exposure to radon daughters and lung-cancer is subject to numerous uncertainties. The greatest of these concerns the parametric values of the dose-response curve. We lack knowledge and an understanding of the dosimetry and the distribution of aggregates of radioactivity that remain localized as hot spots in specific regions of the lungs and the influence on greater or lesser risk of lung cancer per average lung dose than uniformly deposited radiation (NRC76). We have only a limited understanding of the response to exposure to high-LET radiations, such as alpha particles, for which linear risk estimates for low doses are less likely to overestimate the risk, and may, in fact, underestimate the risk (BEIR80). Other uncertainties include the length of the latency period, the RBE for alpha radiation relative to gamma radiation, the period during which the radiation risk is expressed, the risk projection model used - whether absolute or relative - for projecting risk beyond the period of observation, the effect of dose rate and protraction of dose, and the influence of differences in the natural incidence of lung cancer in different populations. In addition, uncertainties are introduced by the biological and life-style risk characteristics of humans, for example, the effect of sex, the effect of age at the time of irradiation and at the time of appearance of the cancer, the influence of length of observation or follow-up of the study populations, and the influence of perhaps the most important confounding bias, cigarette-smoking. The collective influence of these uncertainties is such as to deny great credibility to any estimate of human lung cancer risk and other cancer risk that can be made for low-dose, high-LET radon daughter radiation exposure

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

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1982-06-01

    The quantitative estimation of the carcinogenic risk of low-dose, high-LET radiation in the case of exposure to radon daughters and lung-cancer is subject to numerous uncertainties. The greatest of these concerns the parametric values of the dose-response curve. We lack knowledge and an understanding of the dosimetry and the distribution of aggregates of radioactivity that remain localized as hot spots in specific regions of the lungs and the influence on greater or lesser risk of lung cancer per average lung dose than uniformly deposited radiation (NRC76). We have only a limited understanding of the response to exposure to high-LET radiations, such as alpha particles, for which linear risk estimates for low doses are less likely to overestimate the risk, and may, in fact, underestimate the risk (BEIR80). Other uncertainties include the length of the latency period, the RBE for alpha radiation relative to gamma radiation, the period during which the radiation risk is expressed, the risk projection model used - whether absolute or relative - for projecting risk beyond the period of observation, the effect of dose rate and protraction of dose, and the influence of differences in the natural incidence of lung cancer in different populations. In addition, uncertainties are introduced by the biological and life-style risk characteristics of humans, for example, the effect of sex, the effect of age at the time of irradiation and at the time of appearance of the cancer, the influence of length of observation or follow-up of the study populations, and the influence of perhaps the most important confounding bias, cigarette-smoking. The collective influence of these uncertainties is such as to deny great credibility to any estimate of human lung cancer risk and other cancer risk that can be made for low-dose, high-LET radon daughter radiation exposure.

  6. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables

  7. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.

  8. Study of the health effects of low-level exposure to environmental radiation contamination in Port Hope, Ontario

    International Nuclear Information System (INIS)

    Steele, R.; Lees, R.E.M.; Roberts, J.H.

    1984-06-01

    From 1939 to 1948 residues from radium production at Eldorado Nuclear Ltd.'s plant in Port Hope, Ontario were disposed of in and around the town of Port Hope. In 1980 a study was set up to determine the health effects of these residues. This report concerns phase two a case- control study of lung cancer in the exposed population. Doses for the 118 cases and controls were reconstructed to give the final year of exposure, the residences occupied during the period of exposure, and the total estimated exposure for various latency periods. Statistical analysis of the data gathered could not give coherent results or show an identifiable increased risk of lung cancer from elevated alpha radiation levels due to the confounding effect of cigarette smoking. Ninety percent of the cases of lung cancer found were attributable to smoking

  9. Low-level radiation risks in people

    International Nuclear Information System (INIS)

    Goloman, M.; Filjushkin, V. lgor

    1993-01-01

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

  10. The effects of low-level ionizing radiation and copper exposure on the incidence of antibiotic resistance in lentic biofilm bacteria.

    Science.gov (United States)

    McArthur, J Vaun; Dicks, Christian A; Bryan, A Lawrence; Tuckfield, R Cary

    2017-09-01

    Environmental reservoirs of antibiotic resistant bacteria are poorly understood. Understanding how the environment selects for resistance traits in the absence of antibiotics is critical in developing strategies to mitigate this growing menace. Indirect or co-selection of resistance by environmental pollution has been shown to increase antibiotic resistance. However no attention has been given to the effects of low-level ionizing radiation or the interactions between radiation and heavy metals on the maintenance or selection for antibiotic resistance (AR) traits. Here we explore the effect of radiation and copper on antibiotic resistance. Bacteria were collected from biofilms in two ponds - one impacted by low-level radiocesium and the other an abandoned farm pond. Through laboratory controlled experiments we examined the effects of increasing concentrations of copper on the incidence of antibiotic resistance. Differences were detected in the resistance profiles of the controls from each pond. Low levels (0.01 mM) of copper sulfate increased resistance but 0.5 mM concentrations of copper sulfate depressed the AR response in both ponds. A similar pattern was observed for levels of multiple antibiotic resistance per isolate. The first principal component response of isolate exposure to multiple antibiotics showed significant differences among the six isolate treatment combinations. These differences were clearly visualized through a discriminant function analysis, which showed distinct antibiotic resistance response patterns based on the six treatment groups. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. 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)

  12. Low-level radiation waste management system

    International Nuclear Information System (INIS)

    Kubofcik, K.W.

    1990-01-01

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

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

    International Nuclear Information System (INIS)

    1972-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1972-11-01

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

  15. Health effects of low-level radiation in shipyard workers

    International Nuclear Information System (INIS)

    Matanoski, G.M.

    1991-06-01

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

  16. Estimation of health effects of long-term chronic exposure of the low level radiation among children exposed in consequence of the disaster at the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    Bomko, E.I.; Romanneko, A.E.; Bomko, A.A.

    1997-01-01

    The low level dose effects have been studied for a long time within a framework of biological effects of radiation exposure. The estimation of the dose level of Ukrainian people who have been exposed in consequence of the Chernobyl accident allowed to consider that one of the critical populations which had been exposed to the low level radiation were children residing on the areas contaminated with radionuclides. The purpose of this work is - to reveal a regularity in morbidity and mortality of the critical populations having been exposed to long-term chronic exposure of the low level doses of radiation in consequences of the Chernobyl accident

  17. Non-Linearity of dose-effect relationship on the example of cytogenetic effects in plant cells at low level exposure to ionising radiation

    International Nuclear Information System (INIS)

    Oudalova, Alla; Geras'kin, Stanislav; Dikarev, Vladimir; Dikareva, Nina; Chernonog, Elena; Copplestone, David; Evseeva, Tatyana

    2006-01-01

    -particles [Nagasawa and Little, 1992; Mothersill et al., 1995]. Other phenomena including genomic instability, low-dose hypersensitivity, and increased radiation resistance effects are also under study [Marples et al., 1997; Kadhim et al., 2004; Bonner, 2004]. The nonlinearity of the dose-effect relationship with low level exposures has been demonstrated in a number of studies where chromosome aberrations were considered as the endpoint of interest. For example, the number of radiation-induced dicentrics in human peripheral blood lymphocytes found in [Pohl-Ruling et al., 1983; Lloyd et al., 1988, 1992] did not exceed the control level at doses below 40 mGy, with some experimental points lying significantly below control values. Essential deviations of chromosome aberrations appearance from linearity in mammals were also shown at higher doses of 100-300 mGy [Luchnik and Sevankaev, 1976; Takahashi et al., 1982]. In other species, deviations of cytogenetic effect induced by low doses from linearity have also been reported. For example, the dose response for cytogenetic effects in Chinese hamster fibroblasts and Vicia faba germs at doses from 0 to 2.5 Gy was shown to be non linear with a plateau at low doses by [Zaichkina et al., 1992]. Dose-effect curves on chromosome aberrations in root meristem cells of Pisum sativum plantlets in the dose range of 0-10 Gy also showed non-linear responses with a plateau for doses up to 1 Gy [Zaka et al., 2002]. However the available information on dose-effect relationships at low doses for non-human species is scarce despite its importance. In their natural environment, some non-human species may be at a higher risk of impact than humans because of differences in ecological niches occupied. [Geras'kin et.al., 2003]. Currently, radiation protection of the environment and maintenance of ecosystem sustainability is of a special concern. and the development of a harmonized approach to human and biota protection has been recognized as a challenge for modern

  18. Non-Linearity of dose-effect relationship on the example of cytogenetic effects in plant cells at low level exposure to ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

    Oudalova, Alla; Geras' kin, Stanislav; Dikarev, Vladimir; Dikareva, Nina; Chernonog, Elena [Russian Institute of Agricultural Radiology and Agroecology, RIARAE, 249032 Obninsk (Russian Federation); Copplestone, David [Environment Agency, Millbank Tower, 25th. Floor, 21/24 Millbank, London, SW1P 4XL (United Kingdom); Evseeva, Tatyana [Institute of Biology, Kommunisticheskaya st., 28 Syktyvkar 167610, Komi Republic (Russian Federation)

    2006-07-01

    alpha-particles [Nagasawa and Little, 1992; Mothersill et al., 1995]. Other phenomena including genomic instability, low-dose hypersensitivity, and increased radiation resistance effects are also under study [Marples et al., 1997; Kadhim et al., 2004; Bonner, 2004]. The nonlinearity of the dose-effect relationship with low level exposures has been demonstrated in a number of studies where chromosome aberrations were considered as the endpoint of interest. For example, the number of radiation-induced dicentrics in human peripheral blood lymphocytes found in [Pohl-Ruling et al., 1983; Lloyd et al., 1988, 1992] did not exceed the control level at doses below 40 mGy, with some experimental points lying significantly below control values. Essential deviations of chromosome aberrations appearance from linearity in mammals were also shown at higher doses of 100-300 mGy [Luchnik and Sevankaev, 1976; Takahashi et al., 1982]. In other species, deviations of cytogenetic effect induced by low doses from linearity have also been reported. For example, the dose response for cytogenetic effects in Chinese hamster fibroblasts and Vicia faba germs at doses from 0 to 2.5 Gy was shown to be non linear with a plateau at low doses by [Zaichkina et al., 1992]. Dose-effect curves on chromosome aberrations in root meristem cells of Pisum sativum plantlets in the dose range of 0-10 Gy also showed non-linear responses with a plateau for doses up to 1 Gy [Zaka et al., 2002]. However the available information on dose-effect relationships at low doses for non-human species is scarce despite its importance. In their natural environment, some non-human species may be at a higher risk of impact than humans because of differences in ecological niches occupied. [Geras'kin et.al., 2003]. Currently, radiation protection of the environment and maintenance of ecosystem sustainability is of a special concern. and the development of a harmonized approach to human and biota protection has been recognized

  19. Nuclear power and low level radiation hazards

    International Nuclear Information System (INIS)

    Myers, D.K.; Newcombe, H.B.

    1979-03-01

    Even in the future, nuclear power is expected to contribute less than 1/10th of the present total population exposure to man-made radiation. By the best estimates available, the current health risks of nuclear power generation appear to be much less than those associated with the major alternative sources of energy, with the exception of natural gas which is about equally safe. Uncertainties concerning the radiation risks from nuclear power, from medical x-rays and from the effects of reduced ventillation to conserve heat appear to be less than those associated with estimates of risks from the use of coal and various other sources of energy. This is in part because of the large amount of effort devoted to studies of radiation effects. The benefits in terms of current life expectancy associated with any of the conventional or unconventional methods of power production appear to greatly outweigh the associated current health hazards. (author)

  20. Low-level radiation and cancer deaths

    International Nuclear Information System (INIS)

    Sanders, B.S.

    1978-01-01

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

  1. Low-level radiation effects: a fact book

    International Nuclear Information System (INIS)

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

    1982-01-01

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

  2. Low-level radiation: The cancer controversy

    International Nuclear Information System (INIS)

    Stewart, A.M.

    1990-01-01

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

  3. Health effects of low-level radiations

    International Nuclear Information System (INIS)

    Tubiana, M.

    1982-01-01

    Epidemiological surveys have attempted to assess the carcinogenic risk induced by exposure to low doses of ionizing radiation. Such studies are difficult to carry out because the incidence of radiation induced cancers is of only a few per cent, even following relativity large doses, and because there is no way to distinguish radiation induced cancer from the background of natural human cancers; moreover these surveys are exposed to many biases due to relatively small sizes of the populations studied and the difficulties of finding an appropriate control group, of estimating the absorbed doses and of collecting the data. A few national or international expert committees have analysed the available data and evaluated the carcinogenic effects. Their estimations of the risk, are similar and allow one to quantify the carcinogenic risk for doses above 100 rads. The risks of lower doses must be determined by extrapolation from human data at high doses. This extrapolation requires the knowledge of the dose-effect relationship. A linear extrapolation is most common and probably leads to a conservative estimate of the risk. A linear-quadratic function is probably more realistic and in better accordance with most scientific data. However the validity of its use for the estimation of carcinogenic risk is still debated. In experimental animals, the influence of dose-rate is important and some data suggest that this is the same for the carcinogenic effect in human beings. The genetic effects are probably less important than was feared a few years ago. The most important recent observation is the absence of any significant genetic effect in the progeny of the survivors of the A. bombs in Hiroshima and Nagasaki. This allows a conservative estimate of the maximum genetic risk for human beings [fr

  4. Tradescantia in studies of genetic effects of low level radiation

    International Nuclear Information System (INIS)

    Yamashita, Atsushi

    1976-01-01

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

  5. Mind-sets, low-level exposures, and research

    International Nuclear Information System (INIS)

    Sagan, L.A.

    1993-01-01

    Much of our environmental policy is based on the notion that carcinogenic agents are harmful at even minuscule doses. From where does this thinking come? What is the scientific evidence that supports such policy? Moreover, why is the public willing to buy into this? Or is it the other way around: Has the scientific community bought into a paradigm that has its origins in public imagery? Or, most likely, are there interactions between the two? It is essential that we find out whether or not there are risks associated with low-level exposures to radiation. The author can see three obvious areas where the future depends on better information: The increasing radiation exposures resulting from the use of medical diagnostic and therapeutic practices need to be properly evaluated for safety; Environmental policies, which direct enormous resources to the reduction of small radiation exposures, needs to be put on a firmer scientific basis; The future of nuclear energy, dependent as it is on public acceptance, may well rely upon a better understanding of low-dose effects. Nuclear energy could provide an important solution of global warming and other possible environmental hazards, but will probably not be implemented as long as fear of low-dose radiation persists. Although an established paradigm has great resilience, it cannot resist the onslaught of inconsistent scientific observations or of the social value system that supports it. Only new research will enable us to determine if a paradigm shift is in order here

  6. The hazards of low-level radiation

    International Nuclear Information System (INIS)

    Blackith, R.

    1979-01-01

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

  7. Health effects of low level radiation

    International Nuclear Information System (INIS)

    Chevillard, S.; Ugolin, N.; Lebeau, J.; Ory, K.

    2006-01-01

    Nuclear energy production is necessarily associated with the handling and storage of radioactive elements, which are liable to have deleterious effects on human health, and on environment. These deleterious effects are varied, but they greatly depend on the dose, which has been received, and the exposure type. Therefore, only intense and massive exposures are liable to be clinically detected. They can entail immediate consequences, even lead to the person's death. Thanks to safety measures, which have been implemented to an international scale, this occurs very rarely. Excluding extensive accidental cases, medical irradiation for therapeutic use and conflicts, workers and population in general are exposed to low doses and low dose-rates. Low dose exposures, resulting from either a contamination or an external irradiation are more frequent. In fact, we could say that the whole humanity is concerned by natural exposure, which varies depending on regions, as well as by medical exposure, which varies depending on the medicalisation status of the country. (author)

  8. Health aspects of low-level radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1979-06-01

    A brief description of natural background radiation is given. To understand the relationship between doses and effects the magnitude and distribution over time are stressed. The derivation of radiation protection standards and corresponding risks are discussed. The risks to the occupational worker and to the public from nuclear power are placed in context of risks in other industries and from alternate energy sources, including conservation. (author)

  9. Biological monitors for low levels of ionising radiation

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  10. Biological monitors for low levels of ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  11. Low level radiation: how low can you get?

    International Nuclear Information System (INIS)

    Townsley, M.

    1990-01-01

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

  12. Responses to the low-level-radiation controversy

    International Nuclear Information System (INIS)

    Bond, V.P.

    1981-01-01

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

  13. Effects on populations of exposure to low levels of ionizing radiation: implications for nuclear energy and medical radiation. The 1979 report of the Advisory Committee on the Biological Effects of Ionizing Radiation (The BEIR Report)

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1979-04-01

    The following aspects of the 1979 BEIR report are described: societal decision-making; nuclear energy needs and medical care services; epidemiological and experimental studies; public acceptance; concept of risks to health; risk estimates and cost-benefit analysis; and comparison of risks. Other topics discussed are as follows: need for advisory committees on radiation; value of the BEIR report; health effects of low levels of ionizing radiation; determination of radiation risk estimates; and quantitation of radioinduced cancer risk estimates

  14. Somatic and genetic effects of low-level radiation

    International Nuclear Information System (INIS)

    Upton, A.C.

    1974-01-01

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

  15. Dose response curves for effects of low-level radiation

    International Nuclear Information System (INIS)

    Myers, D.K.

    1980-01-01

    The linear dose-response model used by international committees to assess the genetic and carcinogenic hazards of low-level radiation appears to be the most reasonable interpretation of the available scientific data that are relevant to this topic. There are, of course, reasons to believe that this model may overestimate radiation hazards in certain instances, a fact acknowledged in recent reports of these committees. The linear model is now also being utilized to estimate the potential carcinogenic hazards of other agents such as asbestos and polycyclic aromatic hydrocarbons. This model implies that there is no safe dose for any of these agents and that potential health hazards will increase in direct proportion to total accumulated dose. The practical implication is the recommendation that all exposures should be kept 'as low as reasonably achievable, economic and social factors being taken into account'. (auth)

  16. Genetic effects of low level radiation

    International Nuclear Information System (INIS)

    Sumner, D.

    1988-01-01

    The author outlines the evidence for genetic effects. The incidence of congenital abnormalities, stillbirths and child deaths has been examined in 70,000 pregnancies in Hiroshima and Nagasaki and compared with pregnancies in an unirradiated control group. No difference was detected in incidence of congenital abnormalities of stillbirths, but there was a small insignificant increase in child deaths when both parents were exposed. The number of children born with chromosome aberrations was slightly higher, but insignificant in the exposed group compared with controls. However, surveys of congenital malformations in children of radiologists and in children of Hanford workers suggest a genetic effect of radiation. Absolute and relative methods of calculating risks and the ICRP risk factor is also briefly discussed. (U.K.)

  17. Health effects of low-level ionizing radiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1979-04-01

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

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

    International Nuclear Information System (INIS)

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

    1984-04-01

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

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

    International Nuclear Information System (INIS)

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

    1975-01-01

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

  20. Effect of Low Level Cadmium Exposure on Superoxide Dismutase ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of low level cadmium (Cd) exposure on the activity of superoxide dismutase ... cancer, aging and a diversity of diseases [5]. Superoxide .... responsible for the long biological half-life of cadmium [12]. ... indicator of the balance between the damaging effects and the ... Scand J Work Environ.

  1. More on direct estimates of low-level radiation risks

    International Nuclear Information System (INIS)

    Rinsky, R.

    1982-01-01

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

  2. Effects of low levels of radiation on humans

    International Nuclear Information System (INIS)

    Auxier, J.A.

    1981-01-01

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

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

    International Nuclear Information System (INIS)

    Higson, D.

    2001-01-01

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

  4. New study sees greater low-level radiation threat

    International Nuclear Information System (INIS)

    Lobsenz, G.

    1992-01-01

    A new analysis of Energy Department medical records has found higher than expected cancer rates among workers at DOE's Hanford nuclear weapons plant, suggesting occupational exposure to low-level radiation may be more dangerous than previously thought. The study, released Tuesday by the Philadelphia-based Three Mile Island Public Health Fund, is important not only because of its controversial conclusions, but also because it represents the first independent review of DOE's long-secret worker medical records. The new study done by Stewart and Kneale looked at Hanford worker health records dating up to 1986 - part of a huge trove of data withheld by DOE from independent researchers until two years ago. In their re-analysis of the Hanford worker records, Stewart and Kneale found increased cancer rates among older workers who were over 40 years of age when exposed. And they said that increased susceptibility of older people to radiation-induced cancer was not reflected in the highly influential Japanese atomic bomb studies because people over 50 years of age were open-quotes grossly under-representedclose quotes in the A-bomb analyses, possibly because many bomb victims suffered early deaths from high doses

  5. 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

  6. Legislation and litigation related to low-level radiation injury claims

    International Nuclear Information System (INIS)

    McCraw, T.

    1985-01-01

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

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

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    2005-01-01

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

  8. Effectiveness of Aloe vera leaf extract against low level exposure to gamma radiation induced injury in intestinal mucosa of Swiss mice

    International Nuclear Information System (INIS)

    Gehlot, Prashasnika; Saini, M.R.

    2004-01-01

    Full Text: Human beings can not deny the presence of all sorts of incoming radiations, which are detrimental to life. The small intestine represents one of the major dose limiting normal tissues in radiotherapy because of its high radio sensitivity. The purpose of this study was to determine the effects of Aloe vera, a potential radioprotector. Radioprotective efficacy of aloe vera leaf extract in intestinal mucosa in mice (1 g/kg body weight/day) was studied from 6h to day 20 after gamma irradiation (0.5 Gy(. Villus height, goblet cells/villus section, total cells are good parameters for the assessment of radiation damage. The mice selected from inbreed colony were divided into two groups. The first group was given Aloe vera extract orally for 15 consecutive days and served as experimental group. On 15th day, after 30 min of above treatment animals of both the groups were exposed to 0.5 Gy gamma irradiation and autopsied on 6, 12, 24 h and 5, 10, 20 days. Aloe vera pretreatment resulted in a significant increase (p<0.001) in villus height, total cells whereas globlet cells showed a significant decrease (p<0.001) from respective irradiated controls at each autospy day. The results suggest that Aloe vera pretreatment provides protection against radiation-induced alterations in intestinal mucosa of Swiss mice

  9. Low-level radioactive waste disposal: radiation protection laws

    International Nuclear Information System (INIS)

    Chapuis, A.M.; Guetat, P.; Garbay, H.

    1991-01-01

    The politics of radioactive waste management is a part of waste management and activity levels are one of the components of potential waste pollutions in order to assume man and environment safety. French regulations about personnel and public' radiation protection defines clearly the conditions of radioactive waste processing, storage, transport and disposal. But below some activity levels definite by radiation protection laws, any administrative procedures or processes can be applied for lack of legal regulations. So regulations context is not actually ready to allow a rational low-level radioactive waste management. 15 refs.; 4 tabs.; 3 figs

  10. Low-level radiation: a high-level concern

    International Nuclear Information System (INIS)

    Holden, C.

    1979-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Matanoski, G.M.

    1991-06-01

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

  12. Physiological benefits from low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Luckey, T.D.

    1982-01-01

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

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

    International Nuclear Information System (INIS)

    Gilbert, E.S.

    1984-05-01

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

  14. Genetic damage from low-level and natural background radiation

    International Nuclear Information System (INIS)

    Oftedal, P.

    1988-01-01

    Relevant predictions that have been made of possible low level biological effects on man are reviewed, and the estimate of genetic damage is discussed. It is concluded that in spite of a number of attempts, no clear-cut case of effects in human populations of radiation at natural levels has been demonstrated. The stability of genetic material is dynamic, with damage, repair and selection running as continuous processes. Genetic materials are well protected and are conservative in the extreme, not least because evolution by genetic adaptation is an expensive process: Substitution of one allele A 1 by another A 2 means the death of the whole A 1 population

  15. Hazards of radiation exposure

    International Nuclear Information System (INIS)

    Solomon, S.B.

    1982-01-01

    Radiation induced carcinogenesis and mutagenesis form the main risks to health from exposure to low levels of radiation. There is scant data on somatic and genetic risks at environmental and occupational levels of radiation exposure. The available data on radiation induced carcinogenesis and mutagenesis are for high doses and high dose rates of radiation. Risk assessments for low level radiation are obtained using these data, assuming a linear dose-response relationship. During uranium mining the chief source of radiation hazard is inhalation of radon daughters. The correlation between radon daughter exposure and the increased incidence of lung cancer has been well documented. For radiation exposures at and below occupational limits, the associated risk of radiation induced cancers and genetic abnormalities is small and should not lead to a detectable increase over naturally occurring rates

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

    International Nuclear Information System (INIS)

    Best, T.L.; Hoditschek, B.

    1980-12-01

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

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

    International Nuclear Information System (INIS)

    Savitz, D.A.

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Riklis, E.

    1977-01-01

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

  19. Assessment of exposure pathways connected with construction and operation of concrete bridge reinforced with very low level radioactive steel

    International Nuclear Information System (INIS)

    Panik, M.; Necas, V.

    2012-01-01

    Large amount of low level radioactive material arises during decommissioning of nuclear power plants. Material mostly comprises metal scrap and concrete ruble. Paper deals with recycling and reuse of metal scrap and its utilization as part of reinforcement of concrete bridges under the conditional release concept. Radiation exposure originating in very low level reinforcement steel consists of several exposure pathways. Short-term radiation impact is represented mostly by external exposure pathway and it is relevant to the construction workers and users of the bridge. Long-term radiation impacts on inhabitants living near finished bridge and it is divided into inhalation and ingestion of radionuclides-internal exposure pathways. Radiation impact caused by utilization of very low level radioactive waste was calculated using simulation software VISIPLAN 3D ALARA and GOLDSIM. Results of calculations provide fair summary of possibilities of utilization of conditionally released steel as reinforcement of concrete bridges. (Authors)

  20. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells

    International Nuclear Information System (INIS)

    Canuto, K.S.; Guimaraes, O.R.; Geller, M.; Sergio, L.P.S.; Paoli, F.; Fonseca, A.S.

    2015-01-01

    Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia coli cells that were exposed to ultraviolet C (UVC) radiation. Exponential and stationary wild-type and uvrA-deficient E. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC). Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out. (author)

  1. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells

    Energy Technology Data Exchange (ETDEWEB)

    Canuto, K.S.; Guimaraes, O.R.; Geller, M. [Centro Universitario Serra dos Orgaos, Teresopolis, RJ (Brazil). Centro de Ciencias da Saude; Sergio, L.P.S. [Instituto de Biologia Roberto Alcantara Gomes, Rio de Janeiro, RJ (Brazil). Departamento de Biofisica e Biometria; Paoli, F. [Universidade Federal de Juiz de Fora (UFJF), Juiz de Fora, MG (Brazil). Departamento de Morfologia; Fonseca, A.S., E-mail: adnfonseca@ig.com.br [Universidade Federal do Estado do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Departamento de Ciencias Fisiologicas

    2015-10-15

    Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia coli cells that were exposed to ultraviolet C (UVC) radiation. Exponential and stationary wild-type and uvrA-deficient E. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC). Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out. (author)

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

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1980-01-01

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

  3. 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.)

  4. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. V. E

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1990-01-01

    These tables present data on the effects of low-level radiation dose for the following effects:- pre-conception irradiation and Down's Syndrome, pre-conception irradiation and reproductive damage, surveys of effect in relation to the source of radiation, distribution by maternal preconception exposure of the 7 most common major congenital abnormalities in the Japanese, pre-conception irradiation and childhood malignancies, parental gonadal dose at Hiroshima and Nagasaki in relation to leukemia, sex chromosome aneuploids in children of A-bomb survivors, untoward pregnancy outcomes by parental gonad dose, pre-conception irradiation and chromosomal abnormalities, and intra-uterine irradiation and intelligence. (author).

  5. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. V. E

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1990-01-01

    These tables present data on the effects of low-level radiation dose for the following effects:- pre-conception irradiation and Down's Syndrome, pre-conception irradiation and reproductive damage, surveys of effect in relation to the source of radiation, distribution by maternal preconception exposure of the 7 most common major congenital abnormalities in the Japanese, pre-conception irradiation and childhood malignancies, parental gonadal dose at Hiroshima and Nagasaki in relation to leukemia, sex chromosome aneuploids in children of A-bomb survivors, untoward pregnancy outcomes by parental gonad dose, pre-conception irradiation and chromosomal abnormalities, and intra-uterine irradiation and intelligence. (author)

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  7. Low level exposure to chemicals and immune system

    International Nuclear Information System (INIS)

    Colosio, C.; Birindelli, S.; Corsini, E.; Galli, C.L.; Maroni, M.

    2005-01-01

    Industrialized countries are facing an increase of diseases attributable to an alteration of the immune system function, and concern is growing that this trend could be at least partially attributable to new and modified patterns of exposure to chemicals. Among chemicals matter of concern, pesticides can be included. The Authors have reviewed the existing evidence of pesticide immunotoxicity in humans, showing that existing data are inadequate to raise conclusions on the immunotoxic risk related to these compounds. The limits of existing studies are: poor knowledge on exposure levels, heterogeneity of the approach, and difficulty in giving a prognostic significance to the slight changes often observed. To overcome these limits, the Authors have proposed a tier approach, based on three steps: the first, addressed at pointing out a possible immunomodulation; the second, at refining the results and the third one, when needed, to finalize the study and to point out concordance with previous results. Studies should preferably be carried out through comparison of pre- and post-exposure findings in the same groups of subjects to be examined immediately after the end of the exposure. A simplification of the first step approach can be used by the occupational health physician and the occupational toxicologist. Conclusions on the prognostic significance of the slight changes often observed will be reached only by validating the hypothesis generated by field studies with an epidemiological approach. In this field, the most useful option is represented by longitudinal perspective studies

  8. Low level methylmercury exposure affects neuropsychological function in adults

    Directory of Open Access Journals (Sweden)

    Platt Illeane

    2003-06-01

    Full Text Available Abstract Background The neurotoxic effects of methylmercury (MeHg have been demonstrated in both human and animal studies. Both adult and fetal brains are susceptible to the effects of MeHg toxicity. However, the specific effects of adult exposures have been less well-documented than those of children with prenatal exposures. This is largely because few studies of MeHg exposures in adults have used sensitive neurological endpoints. The present study reports on the results of neuropsychological testing and hair mercury concentrations in adults (>17 yrs living in fishing communities of Baixada Cuiabana (Mato Grosso in the Pantanal region of Brazil. Methods A cross-sectional study was conducted in six villages on the Cuiaba River. Participants included 129 men and women older than 17 years of age. They were randomly selected in proportion to the age range and number of inhabitants in each village. Questionnaire information was collected on demographic variables, including education, occupation, and residence history. Mercury exposure was determined by analysis of hair using flameless atomic absorption spectrophotometry. The neurocognitive screening battery included tests from the Wechsler Memory Scale and the Wechsler Adult Intelligence Scale, Concentrated Attention Test of the Toulouse-Pierron Factorial Battery, the Manual Ability Subtests of the Tests of Mechanical Ability, and the Profile of Mood States. Results Mercury exposures in this population were associated with fish consumption. The hair mercury concentration in the 129 subjects ranged from 0.56 to 13.6 μg/g; the mean concentration was 4.2 ± 2.4 micrograms/g and the median was 3.7 μg/g. Hair mercury levels were associated with detectable alterations in performance on tests of fine motor speed and dexterity, and concentration. Some aspects of verbal learning and memory were also disrupted by mercury exposure. The magnitude of the effects increased with hair mercury concentration

  9. Modeling the transmitted and stored energy in multilayer protective clothing under low-level radiant exposure

    International Nuclear Information System (INIS)

    Su, Yun; He, Jiazhen; Li, Jun

    2016-01-01

    Highlights: • A numerical model from heating source to skin tissues through multilayer fabric system is developed. • The numerical model is comprehensively validated with experimental data. • The model is used to investigate the relationship between the transmitted and stored energy and the influencing factors. - Abstract: A finite difference model was introduced to simulate the transmitted and stored energy in firefighters' protective clothing exposed to low-level thermal radiation. The model domain consists of a three-layer fire-resistant fabric system (outer shell, moisture barrier, and thermal liner), the human skin, and the air gap between clothing and the skin. The model accounted for the relationship between the transmitted heat during the exposure and the discharged heat during the cooling-down period. The numerical model predictions were compared with experimental data. Additionally, the parameters that affect the transmitted and stored energy of protective clothing were investigated. The results demonstrate that for the typical multilayer firefighter protective clothing, the transmitted heat during exposure and the discharged heat after exposure totally determine the skin burn under low-level heat exposure, especially for third-degree skin burns. The findings obtained in this study can be used to engineer fabric systems that provide better protection for the stored thermal burn.

  10. Current practices for maintaining occupational exposures ALARA at low-level waste disposal sites

    International Nuclear Information System (INIS)

    Hadlock, D.E.; Herrington, W.N.; Hooker, C.D.; Murphy, D.W.; Gilchrist, R.L.

    1983-12-01

    The United States Nuclear Regulatory Commission contracted with Pacific Northwest Laboratory (PNL) to provide technical assistance in establishing operational guidelines, with respect to radiation control programs and methods of minimizing occupational radiation exposure, at Low-Level Waste (LLW) disposal sites. The PNL, through site visits, evaluated operations at LLW disposal sites to determine the adequacy of current practices in maintaining occupational exposures as low as is reasonably achievable (ALARA). The data sought included the specifics of: ALARA programs, training programs, external exposure control, internal exposure control, respiratory protection, surveillance, radioactive waste management, facilities and equipment, and external dose analysis. The results of the study indicated the following: The Radiation Protection and ALARA programs at the three commercial LLW disposal sites were observed to be adequate in scope and content compared to similar programs at other types of nuclear facilities. However, it should be noted that there were many areas that could be improved upon to help ensure the health and safety of occupationally exposed individuals

  11. Current practices for maintaining occupational exposures ALARA at low-level waste disposal sites

    Energy Technology Data Exchange (ETDEWEB)

    Hadlock, D.E.; Herrington, W.N.; Hooker, C.D.; Murphy, D.W.; Gilchrist, R.L.

    1983-12-01

    The United States Nuclear Regulatory Commission contracted with Pacific Northwest Laboratory (PNL) to provide technical assistance in establishing operational guidelines, with respect to radiation control programs and methods of minimizing occupational radiation exposure, at Low-Level Waste (LLW) disposal sites. The PNL, through site visits, evaluated operations at LLW disposal sites to determine the adequacy of current practices in maintaining occupational exposures as low as is reasonably achievable (ALARA). The data sought included the specifics of: ALARA programs, training programs, external exposure control, internal exposure control, respiratory protection, surveillance, radioactive waste management, facilities and equipment, and external dose analysis. The results of the study indicated the following: The Radiation Protection and ALARA programs at the three commercial LLW disposal sites were observed to be adequate in scope and content compared to similar programs at other types of nuclear facilities. However, it should be noted that there were many areas that could be improved upon to help ensure the health and safety of occupationally exposed individuals.

  12. Evaluation of cytogenetic damage in nuclear medicine personnel occupationally exposed to low-level ionising radiation

    International Nuclear Information System (INIS)

    Garaj-Vrhovac, V.; Kopjar, N.; Poropat, M.

    2005-01-01

    Despite intensive research over the last few decades, there still remains considerable uncertainty as to the genetic impact of ionising radiation on human populations, particularly at low levels. The aim of this study was to provide data on genetic hazards associated with occupational exposure to low doses of ionising radiation in nuclear medicine departments. The assessment of DNA damage in peripheral blood lymphocytes of medical staff was performed using the chromosome aberration (CA) test. Exposed subjects showed significantly higher frequencies of CA than controls. There were significant inter-individual differences in DNA damage within the exposed population, indicating differences in genome sensitivity. Age and gender were not confounding factors, while smoking enhanced the levels of DNA damage only in control subjects. The present study suggests that chronic exposure to low doses of ionising radiation in nuclear medicine departments causes genotoxic damage. Therefore, to avoid potential genotoxic effects, the exposed medical personnel should minimise radiation exposure wherever possible. Our results also point to the significance of biological indicators providing information about the actual risk to the radiation exposed individuals.(author)

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

    International Nuclear Information System (INIS)

    Hattori, Sadao

    1998-01-01

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

  14. Historical background and overview of epidemiological studies on the effects of low-level radiation

    International Nuclear Information System (INIS)

    Upton, A.C.

    1983-01-01

    Recognition of the carcinogenic effects of ionizing radiation dates from the early part of this century, when an increased frequency of skin cancer and leukemia was first reported in radiologists. In the interim, systematic epidemiological studies have disclosed additional carcinogenic effects in radiation workers, A-bomb survivors, patients exposed to diagnostic or therapeutic radiation, and other groups. The studies have provided sufficient data on dose-incidence relationships, the distribution of cancer in relation to age at irradiation and time after exposure, and organ-variations in susceptibility to enable attempts at quantitative assessment of the risks of low-level irradiation. Such assessments, although tentative and controversial, have exerted an important influence on developments in radiological protection

  15. Low-level radiation effects on immune cells

    International Nuclear Information System (INIS)

    Makinodan, T.

    1995-01-01

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

  16. A cytogenetic approach to the effects of low levels of ionizing radiations on occupationally exposed individuals

    Energy Technology Data Exchange (ETDEWEB)

    Zakeri, Farideh [National Radiation Protection Department, Iranian Nuclear Regulatory Authority, Nuclear Science and Research Institute-Agriculture, Medicine and Industry Research School, Tehran (Iran, Islamic Republic of); Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba 263-8522 (Japan)], E-mail: fzakeri@aeoi.org.ir; Hirobe, Tomohisa [Graduate School of Science and Technology, Chiba University, Inage-ku, Chiba 263-8522 (Japan); Radiation Effect Mechanism Research Group, National Institute of Radiological Sciences, Inage-ku, Chiba 263-8555 (Japan)

    2010-01-15

    The aim of the present study was to assess occupationally induced chromosomal damage in hospital workers exposed to low levels of ionizing radiation. Thirty-two interventional cardiologists, 36 nuclear medicine physicians and 33 conventional radiologists were included in this study, along with 35 healthy age- and sex-matched individuals as the control group. We used conventional metaphase chromosome aberration (CA) analysis, cytokinesis-block micronucleus (MN) assay as important biological indicators of ionizing radiation exposure. Occupational dosimetry records were collected over the last year (ranged from 0.25 to 48 mSv) and their whole life exposure (ranged from 1.5 to 147 mSv). The results showed significantly higher frequencies of dicentric and acentric CAs (p < 0.001) and MN (p < 0.01) in all exposed groups than in the controls. Taking all the confounding factors into account, no obvious trend of increased chromosomal damages as a function of either duration of employment, exposed dose, sex or age was observed. Interventional cardiologists had the highest rates of CA and MN frequencies between the worker groups, though the differences were not significant. These results indicate that long term exposure to low dose ionizing radiation could result in DNA damage. Hence, the personnel who work in the hospitals should carefully apply the radiation protection procedures.

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

    International Nuclear Information System (INIS)

    Myers, D.K.

    1977-12-01

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

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

    International Nuclear Information System (INIS)

    Upton, A.C.

    1986-01-01

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

  19. Metabonomics of Pig Blood Plasma Following Whole Body Exposure to Low Levels of Gb Vapor

    National Research Council Canada - National Science Library

    Bevilacqua, Vicky L; D'Onofrio, Terreiice G; Jakubowski, K. M; Hulet, Stanley W; Maguire, Kelly J; Edwards, Jennifer L; Laramee, James A; Brickhouse, Mark D

    2005-01-01

    ...), for which complex data must be analyzed. Therefore, we have begun an exploration of the use of chemometrics for the correlation of metabolic change with low-level CWA exposure in animal models...

  20. CHEMICAL WEAPONS: DoD Does Not Have a Strategy to Address Low-Level Exposures

    National Research Council Canada - National Science Library

    1998-01-01

    The possible exposure of U.S. troops to low levels of chemical warfare agents in Iraq in the weeks after the Gulf War ceasefire, along with chemical warfare prophylaxis, vaccines, oil well fire emissions, and other battlefield...

  1. Respiratory health effects of exposure to low levels of airborne endotoxin - a systematic review.

    Science.gov (United States)

    Farokhi, Azadèh; Heederik, Dick; Smit, Lidwien A M

    2018-02-08

    Elevated endotoxin levels have been measured in ambient air around livestock farms, which is a cause of concern for neighbouring residents. There is clear evidence that occupational exposure to high concentrations of airborne endotoxin causes respiratory inflammation, respiratory symptoms and lung function decline. However, health effects of exposure to low levels of endotoxin are less well described. The aim of this systematic review is to summarize published associations between exposure to relatively low levels of airborne endotoxin and respiratory health endpoints. Studies investigating respiratory effects of measured or modelled exposure to low levels of airborne endotoxin (average effects of exposure to low levels of endotoxin on respiratory symptoms and lung function. However, considerable heterogeneity existed in the outcomes of the included studies and no overall estimate could be provided by meta-analysis to quantify the possible relationship. Instead, a best evidence synthesis was performed among studies examining the exposure-response relationship between endotoxin and respiratory outcomes. Significant exposure-response relationships between endotoxin and symptoms and FEV 1 were shown in several studies, with no conflicting findings in the studies included in the best evidence synthesis. Significantly different effects of endotoxin exposure were also seen in vulnerable subgroups (atopics and patients with broncho-obstructive disease) and smokers. Respiratory health effects of exposure to low levels of airborne endotoxin (health effects, especially in vulnerable subgroups of the population.

  2. Cancer risks and low-level radiation in U.S. shipyard workers

    International Nuclear Information System (INIS)

    Matanoski, Genevieve M.; Tonascia, James A.; Correa-Villasenor, Adolfo; Yates, Katherine C.; Fink, Nancy; Elliott, Elizabeth; Sanders, Bruce; Lantry, Deborah

    2008-01-01

    The risks for four cancers, leukemia, lymphopoietic cancers (LHC), lung cancer and mesothelioma, were studied in workers from shipyards involved in nuclear powered ship overhauls. The population represented a sample of all workers based on radiation dose at study termination. The final sample included 28,000 workers with ≥5.0 mSv, 10,462 workers with <5.0 mSv and 33,353 non-nuclear workers. Nuclear workers had lower mortality rates for leukemia and LHC than United States (US) white males but higher rates of lung cancer and a significant five-fold excess of mesothelioma. Dose-dependent analyses of risks in the high exposure group indicated that for each cancer the risk increased at exposures above 10.0 mSv. An internal comparison of workers with 50.0 mSv exposures to workers with exposures of 5.0-9.9 mSv indicated relative risks for leukemia of 2.41 (95% CI: 0.5, 23.8), for LHC, 2.94 (95% CI: 1.0, 12.0), for lung cancer, 1.26 (95% CI: 0.9, 1.9) and for mesothelioma, 1.61 (95% CI: 0.4, 9.7) for the higher exposure group. Except for LHC, these risks are not significant. However, the increasing risk with increasing exposure for these cancers, some of which are known to be related to radiation, suggests that low-level protracted exposures to gamma rays may be associated with these cancers. Other agents such as asbestos, which are common to shipyard work, may play a role especially in the risk of mesothelioma. Future follow up of the population would identify bounds on radiation risks for this population for comparison with similar risks estimated from other populations. (author)

  3. Cytogenetic and hematological studies in the workers occupationally exposed to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Zakeri, F.; Honarjoo, M.; Rajab pour, M.; Zahadat, A.; Ahmad pour, M.J.; Asghari, K.

    2007-01-01

    Complete text of publication follows. Objective: This study was aimed at detecting both the incidence of chromosomal aberrations and changes in the hematological parameters as biomarkers of possible radiation injury among workers occupationally exposed to low levels of ionizing radiation and detecting the dose-effect relationship. Methods: Samples of peripheral blood were collected from 38 male industrial radiographers exposed to ionizing radiation for 1-16 years and from 24 age- and sex-matched healthy blood donors without radiation history served as control group. All radiation workers were routinely monitored with film badge. Cytogenetic analysis in peripheral blood lymphocytes assessed by the conventional chromosome aberration assay and at least 200 metaphases for each person were scored. The collected blood samples were analyzed for hematological assay using an automatic analyzer Sysmex KX-21, where 14 different parameters were computerized. Mann-Whitney U test was used to compare the frequencies of the unstable aberrations and hematological parameters between test and control groups. Dose-effect relationship and the influence of age and duration of employment was tested by regression analysis. Results and conclusion: The mean frequencies of dicentric and acentric chromosome aberrations were significantly higher in the exposed group than in the control group (P< 0.0005). No correlation between chromosomal aberrations and physical dose and age was observed in the exposed group. Also there is no clear relation between chromosome damage and duration of exposure. However, the increase in chromosome aberrations in the exposed group was not followed by a corresponding hematological depression. The average values of hematological indices were within the reference levels and did not show any significant differences with control group. A tendency of decreasing the absolute lymphocyte count within the referential levels was the only hematological effect in radiation

  4. Cytogenetic monitoring of hospital workers exposed to low-level ionizing radiation

    International Nuclear Information System (INIS)

    Bigatti, P.; Lamberti, L.; Ardito, G.; Armellino, F.

    1988-01-01

    In the present study the cytogenetic effects in hospital workers exposed to low-level radiation were evaluated. Samples of peripheral blood were collected from 63 subjects working in radiodiagnostics and from 30 subjects, working in the same hospitals, who were used as controls. A higher number of cells with chromosome-type aberrations (CA) was observed in the exposed workers vs. the controls and the difference was statistically significant (p<0.05). No correlation was, on the contrary, found between CA and years of exposure. A significant difference was observed in the incidence of cells with CA between smokers and non-smokers, but in the control group only. In contrast, in the workers exposed to ionizing radiation, the frequency of cells with CA was very similar in smokers and non-smokers. 13 refs.; 4 tabs

  5. Childhood leukaemia and low-level radiation - are we underestimating the risk?

    International Nuclear Information System (INIS)

    Wakeford, R.

    1996-01-01

    The Seascale childhood leukaemia 'cluster' can be interpreted as indicating that the risk of childhood leukaemia arising from low-level exposure to ionising radiation has been underestimated. Indeed, several variants of such an interpretation have been advanced. These include exposure to particular radionuclides, an underestimation of the radiation risk coefficient for childhood leukaemia, and the existence of a previously unrecognized risk of childhood leukaemia from the preconceptional irradiation of fathers. However, the scientific assessment of epidemiological associations is a complex matter, and such associations must be interpreted with caution. It would now seem most likely that the Seascale 'cluster' does not represent an unanticipated effect of the exposure to ionising radiation, but rather the effect of unusual population mixing generated by the Sellafield site which has produced an increase in the infection-based risk of childhood leukaemia. This episode in the history of epidemiological research provides a timely reminder of the need for great care in the interpretation-of novel statistical associations. (author)

  6. Mapping very low level occupational exposure in medical imaging: A useful tool in risk communication and decision making

    Energy Technology Data Exchange (ETDEWEB)

    Covens, P., E-mail: pcovens@vub.ac.be [Health Physics Department, Vrije Universiteit Brussel and UZ Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium); Beeldvorming en Fysische Wetenschappen (BEFY), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium); Berus, D., E-mail: dberus@vub.ac.be [Health Physics Department, Vrije Universiteit Brussel and UZ Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium); Mey, J. de, E-mail: Johan.DeMey@uzbrussel.be [Department of Radiology, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium); Beeldvorming en Fysische Wetenschappen (BEFY), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium); Buls, N., E-mail: Nico.Buls@uzbrussel.be [Department of Radiology, UZ Brussel, Laarbeeklaan 101, 1090 Brussels (Belgium); Beeldvorming en Fysische Wetenschappen (BEFY), Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels (Belgium)

    2012-09-15

    Objectives: The use of ionising radiation in medical imaging is accompanied with occupational exposure which should be limited by optimised room design and safety instructions. These measures can however not prevent that workers are exposed to instantaneous dose rates, e.g. the residual exposure through shielding or the exposure of discharged nuclear medicine patients. The latter elements are often questioned by workers and detailed assessment should give more information about the impact on the individual radiation dose. Methods: Cumulated radiation exposure was measured in a university hospital during a period of 6 months by means of thermoluminescent dosimeters. Radiation exposure was measured at background locations and at locations where enhanced exposure levels are expected but where the impact on the individual exposure is unclear. Results: The results show a normal distribution of the cumulated background radiation level. No enhanced cumulated radiation exposure which significantly differs from this background level could be found during the operation of intra-oral apparatus, during ultrasonography procedures among nuclear medicine patients and at operator consoles of most CT-rooms. Conclusions: This 6 months survey offers useful information about occupational low level exposure in medical imaging and the findings can be useful in both risk communication and decision making.

  7. Mapping very low level occupational exposure in medical imaging: A useful tool in risk communication and decision making

    International Nuclear Information System (INIS)

    Covens, P.; Berus, D.; Mey, J. de; Buls, N.

    2012-01-01

    Objectives: The use of ionising radiation in medical imaging is accompanied with occupational exposure which should be limited by optimised room design and safety instructions. These measures can however not prevent that workers are exposed to instantaneous dose rates, e.g. the residual exposure through shielding or the exposure of discharged nuclear medicine patients. The latter elements are often questioned by workers and detailed assessment should give more information about the impact on the individual radiation dose. Methods: Cumulated radiation exposure was measured in a university hospital during a period of 6 months by means of thermoluminescent dosimeters. Radiation exposure was measured at background locations and at locations where enhanced exposure levels are expected but where the impact on the individual exposure is unclear. Results: The results show a normal distribution of the cumulated background radiation level. No enhanced cumulated radiation exposure which significantly differs from this background level could be found during the operation of intra-oral apparatus, during ultrasonography procedures among nuclear medicine patients and at operator consoles of most CT-rooms. Conclusions: This 6 months survey offers useful information about occupational low level exposure in medical imaging and the findings can be useful in both risk communication and decision making

  8. Scientific view of low-level radiation risks

    International Nuclear Information System (INIS)

    Hall, E.J.

    1991-01-01

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

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

    International Nuclear Information System (INIS)

    Bhatia, A.L.

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-09-01

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

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

    International Nuclear Information System (INIS)

    1978-09-01

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

  12. The association betweeen cancers and low level radiation: An evaluation of the epidemiological evidence at the Hanford Nuclear Weapons Facility

    International Nuclear Information System (INIS)

    Britton, J.

    1993-05-01

    Cancer has traditionally been linked to exposure to high doses of radiation, but there is considerable controversy regarding the carcinogenicity of low doses of ionizing radiation in humans. Over the past 30 years there have been 14 studies conducted on employees at the Hanford nuclear weapons facility to investigate the relationship between exposure to low doses of radiation and mortality due to cancer (1-14). Interest in this issue was originally stimulated by the Atomic Energy Commission (AEC) which was trying to determine whether the linear extrapolation of health effects from high to low dose exposure was accurate. If the risk has been underestimated, then the maximum permissible occupational radiation exposure in the United States had been set too high. Because the health risk associated with low level radiation are unclear and controversial it seems appropriate to review the studies relating to Hanford at this time

  13. Techniques for detecting and determining risks from low-level radiation

    International Nuclear Information System (INIS)

    Boice, J.D.

    1980-01-01

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

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

    International Nuclear Information System (INIS)

    Hamilton, L.D.

    1983-01-01

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

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

    International Nuclear Information System (INIS)

    Wolfe, B.; Wallis, L.R.

    1988-01-01

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

  16. Cytogenetic Analysis In Blood Lymphocyte From Workers Occupationally Exposed To Low Levels Of Radiation

    International Nuclear Information System (INIS)

    Rahimah Abdul Rahim; Mohd Rodzi Ali; Noraisyah Mohd Yusof; Juliana Mahamad Napiah; Yahaya Talib; Shafii Khamis

    2016-01-01

    Whether it comes from the ground, the sky, or medical treatment, humans are constantly exposed to ionizing radiation from the world around them. This is a normal occurrence, and has always been the case. According to the IAEA International Basic Safety Standard, the radiation dose for public is not more than 1 mSv per year. That is just an average though, and the actual figure may fluctuate widely per person depending on where they live and the medical procedures they had that year. The international standard is to allow people who work with and around radioactive material (researchers, nuclear power plant workers, X-ray technicians and others) to have exposures of not more than 20 mSv total per year. The 20 mSv annual dose is considered to be safe and not significantly increase the risk for radiation-related health effects. Biological dosimetry based on the analysis of micronuclei in the cytokinesis-block micronucleus (CBMN) assay can be used as an alternative method for scoring dicentric chromosomes in the field of radiation protection. Bio dosimetry is mainly performed, in addition to the physical dosimetry, with the aim of individual dose assessment. The aim of the present study was to perform a cytogenetic analysis in peripheral blood lymphocyte of 30 individuals occupationally exposed to low level of ionizing radiation and compare the result with 30 controls using CBMN assay. Number of bi-nucleated cell and micronuclei were scored and statistical analysis was done to see the effect of micronuclei with gender, age and occupation. In conclusion, scoring of micronuclei is a useful cytogenetic monitoring for radiation workers and assessment of genetic damage. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-07-01

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

  18. Long-term exposure to low-level arsenic in drinking water and diabetes incidence

    DEFF Research Database (Denmark)

    Bräuner, Elvira Vaclavik; Nordsborg, Rikke Baastrup; Andersen, Zorana Jovanovic

    2014-01-01

    BACKGROUND: Established causes of diabetes do not fully explain the present epidemic. High-level arsenic exposure has been implicated in diabetes risk, but the effect of low-level arsenic exposure in drinking water remains unclear. OBJECTIVE: We sought to determine whether long-term exposure to low......-level arsenic in drinking water in Denmark is associated with an increased risk of diabetes using a large prospective cohort. METHODS: During 1993-1997, we recruited 57,053 persons. We followed each cohort member for diabetes occurrence from enrollment until 31 December 2006. We traced and geocoded residential...... exposure and diabetes incidence, separately for two definitions of diabetes: all cases and a more strict definition in which cases of diabetes based solely on blood glucose results were excluded. RESULTS: Over a mean follow-up period of 9.7 years for 52,931 eligible participants, there were a total of 4...

  19. Effects of low level radiation upon the hematopoietic stem cell: Implications for leukemogenesis

    International Nuclear Information System (INIS)

    Cronkite, E.P.; Bond, V.P.; Carsten, A.L.; Miller, M.E.; Bullis, J.E.; Inoue, T.; Yokohama City Univ.

    1987-01-01

    These studies have addressed firstly the effect of single small doses of X-rays upon murine hematopoietic stem cells to obtain a better estimate of the D q . It is small, of the order of 20 rad. Secondly, a dose fractionation schedule that does not kill or perturb the kinetcs of hemopoietic cell proliferation was sought in order to investigate the leukemogenic potential of low level radiation upon an unperturbed hemopoietic system. Doses used by others in past radiation leukemogenesis studies clearly perturb hemopoiesis and kill a detectable fraction of stem cells. The studies reported herein show that 1.25 rad every day decrease the CFU-S content of bone marrow by the time 80 rads are accumulated. Higher daily doses as used in published studies on radiation leukemogenesis produce greater effects. Studies on the effect of 0.5, 1.0, 2.0, and 3.0 rad 3 times per week are under way. Two rad 3 times per week produced a modest decrease in CFU-S content of bone marrow after an accumulation of 68 rad. With 3.0 rad 3 times per week an accumulation of 102 rad produced a significant decrease in CFU-S content of bone marrow. Dose fractionation at 0.5 and 1.0 rad 3 times per week has not produced a CFU-S depression after accumulation of 17 and 34 rad. Radiation leukemogenesis studies published to date have utilized single doses and chronic exposure schedules that probably have significantly perturbed the kinetcs of hematopoietic stem cells. Whether radiation will produce leukemia in animal models with dose schedules that do not perturb kinetics of hematopoietic stem cells remains to be seen. (orig.)

  20. Effects of low-level radiation upon the haematopoietic stem cell. Implications for leukaemogenesis

    International Nuclear Information System (INIS)

    Cronkite, E.P.; Bond, V.P.; Carsten, A.L.; Miller, M.E.; Bullis, J.E.

    1983-01-01

    These studies address first the effect of single small doses of X-rays upon murine haematopoietic stem cells to obtain a better estimate of the Dsub(q). It is small, of the order of 20 rad. Second, a dose fractionation schedule that does not kill or perturb the kinetics of haematopoietic cell proliferation was sought to investigate the leukaemogenic potential of low-level radiation upon an unperturbed haematopoietic system. Doses used by others in past radiation leukaemogenesis studies clearly perturb haematopoiesis and kill a detectable fraction of stem cells. The studies reported in the paper show that 1.25 rad every day decreases the CFU-S content of bone marrow by the time 80 rad are accumulated. Higher daily doses as used in published studies on radiation leukaemogenesis produce greater effects. Studies of the effect of 0.5, 1.0, 2.0 and 3.0 rad three times per week are under way. Two rad three times per week produce a modest decrease in CFU-S content of bone marrow after an accumulation of 68 rad. With 3.0 rad three times per week, an accumulation of 102 rad produces a significant decrease in CFU-S content of bone marrow. Dose fractionation at 0.5 and 1.0 rad three times per week has not produced a CFU-S depression after accumulation of 17 and 34 rad. Radiation leukaemogenesis studies published to date have used single doses and chronic exposure schedules that probably have significantly perturbed the kinetics of haematopoietic stem cells. Whether radiation will produce leukaemia in animal models with dose schedules that do not perturb the kinetics of haematopoietic stem cells remains to be seen. (author)

  1. Radiation safety and health effects related to low-level radioactive wastes

    International Nuclear Information System (INIS)

    King, W.C.

    1979-01-01

    The hazards associated with low-level radioactive waste, one of the nation's greatest concerns, are discussed from a health physicist's perspective. Potential biological hazards, four stages of the low-level radioactive waste disposal process, and suggested methods of reducing the risks of handling and disposal, based on previous studies, are defined. Also discussed are potential pathways of human exposure and two scenarios designed to demonstrate the complexity of modeling exposure pathways. The risks of developing a fatal cancer from exposure to the radioactive material, should it occur, is compared to other more commonly accepted risks

  2. Radio-adaptation: cellular and molecular features of a response to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Rigaud, O.

    1998-01-01

    It is well established that sublethal doses of DNA damaging agents induce protective mechanisms against a subsequent high dose treatment ; for instance, the phenomenon of radio-adaptation in the case of ionizing radiations. Since the early observation described in 1984, numerous studies have confirmed the radio-adaptive response in terms of reduction of chromosomal breaks for varied biological models in vitro and in vivo. Evidence for an adaptive response against the induction of gene mutations and the lethal effect is clearly demonstrated. This paper reviews the experimental results describing various aspects of these adaptive responses expressed on these different biological end-points. The molecular mechanism underlying radio-adaptation still remains nuclear. The development of this phenomenon requires de novo synthesis of transcripts and proteins during the time interval between the two doses. Some data are consistent with the hypotheses that these gene products would be involved in the activation of DNA repair pathways and antioxidant systems. However, a major question still remains unanswered; indeed, it is not clear whether or not the radio-adaptation could affect the estimation of cancer risk related with low level exposure to ionizing radiation, a major concern in radioprotection. Until such data are available, it is yet unwise to evoke the beneficial effects of radio-adaptation. (authors)

  3. Survey of studies of occupational populations exposed to low-level radiation

    International Nuclear Information System (INIS)

    Marks, S.

    1980-04-01

    Studies of occupational populations exposed to large doses of radiation, principally from the ingestion of radium by dial painters and inhalation of radon and its daughters by miners, have provided important information on the health effects of those radioisotopes. Studies of medical radiologists, military personnel exposed to nuclear tests, and factory workers exposed to thorium are in progress. Employees of DOE-contractor facilities and of naval shipyards are also under study. Personnel dosimetry data are generally available for the latter category of occupational populations. Reasons for conducting the studies include interest in exploring the verification at low exposure levels of results of studies of heavily exposed populations and the responsibility of the employer to maintain adequate surveillance of the health of his workers by conducting appropriate epidemiologic studies. The low level of exposure of workers in facilities where adequate personnel dosimetry records are available make it unlikely that the results of such studies can be used to provide health risk estimates in the near future

  4. TP53 and ATM mRNA expression in skin and skeletal muscle after low-level laser exposure.

    Science.gov (United States)

    Guedes de Almeida, Luciana; Sergio, Luiz Philippe da Silva; de Paoli, Flavia; Mencalha, Andre Luiz; da Fonseca, Adenilson de Souza

    2017-08-01

    Low-level lasers are widespread in regenerative medicine, but the molecular mechanisms involved in their biological effects are not fully understood, particularly those on DNA stability. Therefore, this study aimed to investigate mRNA expression of genes related to DNA genomic stability in skin and skeletal muscle tissue from Wistar rats exposed to low-level red and infrared lasers. For this, TP53 (Tumor Protein 53) and ATM (Ataxia Telangiectasia Mutated gene) mRNA expressions were evaluated by real-time quantitative PCR (RT-qPCR) technique 24 hours after low-level red and infrared laser exposure. Our data showed that relative TP53 mRNA expression was not significantly altered in both tissues exposed to lasers. For ATM, relative mRNA expression in skin tissue was not significantly altered, but in muscle tissue, laser exposure increased relative ATM mRNA expression. Low-level red and infrared laser radiations alter ATM mRNA expression related to DNA stability in skeletal muscle tissue.

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

    Science.gov (United States)

    Wolfe, B; Wallis, L R

    1988-08-01

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

  6. Effects of low-level blast exposure on the nervous system: Is there really a controversy?

    Directory of Open Access Journals (Sweden)

    Gregory A Elder

    2014-12-01

    Full Text Available High-pressure blast waves can cause extensive CNS injury in humans. However, in combat settings such as Iraq and Afghanistan, lower level exposures associated with mild TBI (mTBI or subclinical exposure have been much more common. Yet controversy exists concerning what traits can be attributed to low-level blast, in large part due to the difficulty of distinguishing blast-related mTBI from post-traumatic stress disorder (PTSD. We describe how TBI is defined in humans and the problems posed in using current definitions to recognize blast-related mTBI. We next consider the problem of applying definitions of human mTBI to animal models, in particular that TBI severity in humans is defined in relation to alteration of consciousness at the time of injury, which typically cannot be assessed in animals. However, based on outcome assessments a condition of low-level blast exposure can be defined in animals that likely approximates human mTBI or subclinical exposure. We review blast injury modeling in animals noting that inconsistencies in experimental approach have contributed to uncertainty over the effects of low-level blast. Yet animal studies show that low-level blast pressure waves are transmitted to the brain. In brain low-level blast exposures cause behavioral, biochemical, pathological and physiological effects on the nervous system including the induction of PTSD-related behavioral traits in the absence of a psychological stressor. We review the relationship of blast exposure to chronic neurodegenerative diseases noting the paradoxical lowering of Abeta by blast, which along with other observations suggest that blast-related TBI is pathophysiologically distinct from non-blast TBI. Human neuroimaging studies show that blast-related mTBI is associated with a variety of chronic effects that are unlikely to be explained by co-morbid PTSD. We conclude that abundant evidence supports low-level blast as having long-term effects on the nervous system.

  7. Effects of low-level radiation upon the hematopoietic steam cell: implications for leukemogenesis

    International Nuclear Information System (INIS)

    Cronkite, E.P.; Bond, V.P.; Carsten, A.L.; Miller, M.E.; Bullis, J.E.

    1983-01-01

    These studies have addressed firstly the effect of single small doses of x-ray upon murine hematopoietic stem cells to obtain a better estimate of the D/sub q/. It is small, of the order of 20 rads. Secondly, a dose fractionation schedule tht does not kill or perturb the kinetics of hemopoietic cell proliferation was sought in order to investigate the leukemogenic potential of low level radiation upon an unperturbed hemopoietic system. The studies reported herein show tht 1.25 rads every other day decrease the CFU-S content of bone marrow by the time 40 rads are accumulated. Studies on the effect of 0.5, 1.0, 2.0, and 3.0 rads 3 times per week are under way. Two rads 3 times per week produced a modest decrease in CFU-S content of bone marrow after an accumulation of 68 rads. With 3.0 rads 3 times per week an accumulation of 102 rads produces a significant decrease in CFU-S content of bone marrow. Dose fractionation at 0.5 and 1.0 rad 3 times per week has not produced a CFU-S depression after accumulation of 17 and 34 rads. Radiation leukemogenesis studies published to date have utilized single doses and chronic exposure schedules that probably have significantly perturbed the kinetics of hematopoietic stem cells. Whether radiation will produce leukemia in animal models with dose schedules that do not perturb kinetics of hematopoietic stem cells remains to be seen

  8. Occurrence of 210Po and Biological Effects of Low-Level Exposure: The Need for Research

    OpenAIRE

    Seiler, Ralph L.; Wiemels, Joseph L.

    2012-01-01

    Background: Polonium-210 (210Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of 210Po are common in sediments, and segments of the public may be chronically exposed to low levels of 210Po in drinking water or in food products from animals raised in contaminated areas. Objectives: We summarized information on the environmental behavior, bioki...

  9. Current status of research on radiation hormesis in the immune system after low level radiation

    International Nuclear Information System (INIS)

    Liu Shuzheng

    1995-01-01

    The paper highlights the chief results of experimental studies recently carried out in the author's laboratory on the stimulatory effects of low level radiation on immunity. The intercellular relationship within the immune system after whole-body irradiation (WBI) with low doses of X- and gamma-rays was briefly outlined with the emphasis on the potential effect of low dose radiation (LDR) on the helper T cells which was thought to occupy a pivotal position in the process of immuno-stimulation. Data suggesting the facilitation by LDR of the signal transduction process within the T cells were presented. Some hypotheses prevailing in the literature for the explanation of the stimulatory effect of LDR were critically evaluated. Existing experimental data both from the literature and from the author's laboratory were analysed giving no strong support to the speculation of either the preferential deletion of the radiosensitive suppressor T subset or the increased apoptosis of the T cell 'precursors' in the thymus leading to secondary immunologic augmentation by low doses which stimulate immune functions. The possible influence of systemic changes, especially those in the neuroendocrine regulation, on the T cell potentiation following LDR was suggested. Finally the biological implications of the hermetic effects of LDR were discussed

  10. SRXRF study of trace elements in hippocampus of pup rats after prenatal and postnatal exposure to low-level mercury

    International Nuclear Information System (INIS)

    Zhang Fang; Feng Weiyue; Chai Zhifang; Wang Meng; Shi Junwen; Huang Yuying; He Wei

    2005-01-01

    Since the pollution of mercury in the environment still keeps high, more and more concerns over mercury toxicity are focused on the potential risk associated with relatively low-dose and long-term mercury exposure in the environment. It is well known that fetus and developing children are the susceptive victims of mercury damage. Therefore, high attention is focused on whether the prenatal and postnatal exposure to relatively low level of mercury will be harmful to children development. Some epidemiological studies reported that the methylmercury-related neuropsychological deficits were mainly found in the domains of cognitional parts, such as language, attention, memory, and so forth, Our previous study found out that high level of mercury was accumulated in the pup hippocampus after their prenatal and postnatal exposure to low dose of inorganic mercury. Synchrotron radiation X-ray fluorescence technique (SRXRF) is characterized of its simultaneous determination of multi-elements, high sensitivity, small sampling amount and microanalysis. SRXRF does not cause the damage of irradiated samples. Thus, it makes possible to measure the distributions of trace elements in a selected area. In this study, in order to study the effects of low-level mercury exposure to pup rat brain, some oxidation-related elements, e.g. Cu, Fe and Mn in pup hippocampus after in utero and weaning exposure to low-level inorganic mercury were determined by SRXRF. The experiment was performed at a synchrotron radiation facility at Institute of High Energy Physics. And the spot size of the beam irradiating on the sample was adjusted to about 100 x 200 μm 2 , Each spot was irradiated for about 100 s. The spectra were analyzed by the AXIL program. Additionally, the activities of some important antioxidant enzymes, such as GSH-Px, SOD, CAT, were also measured together with the content of malondialdehyde (MDA). The results showed that mercury exposure could lead to significant increase of both

  11. A biological basis for the linear non-threshold dose-response relationship for low-level carcinogen exposure

    International Nuclear Information System (INIS)

    Albert, R.E.

    1981-01-01

    This chapter examines low-level dose-response relationships in terms of the two-stage mouse tumorigenesis model. Analyzes the feasibility of the linear non-threshold dose-response model which was first adopted for use in the assessment of cancer risks from ionizing radiation and more recently from chemical carcinogens. Finds that both the interaction of B(a)P with epidermal DNA of the mouse skin and the dose-response relationship for the initiation stage of mouse skin tumorigenesis showed a linear non-threshold dose-response relationship. Concludes that low level exposure to environmental carcinogens has a linear non-threshold dose-response relationship with the carcinogen acting as an initiator and the promoting action being supplied by the factors that are responsible for the background cancer rate in the target tissue

  12. Health effects of low-level radiation in shipyard workers: report of previous work

    International Nuclear Information System (INIS)

    Matanoski, G.M.

    1984-01-01

    Progress over the course of the Nuclear Shipyard Workers Study is reported. The derivation of the study population, the gathering of health histories, the US Navy radiation protection program, and the determination of radiation exposures is described

  13. Epidemiological survey of the effects of low level radiation dose: a comparative assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1993-10-01

    This volume presents the collations tables of a six volume comparative epidemiological survey of the effects of low level radiation dose. Data are collated for the effects observed in the following irradiated groups:- Preconception irradiation, intra-uterine irradiation, childhood irradiation, adult irradiation. (UK).

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

    International Nuclear Information System (INIS)

    Arkhipchuk, V.V.

    1990-01-01

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

  15. 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)

  16. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation.

    Science.gov (United States)

    Susko, Michele L; Bloom, Michael S; Neamtiu, Iulia A; Appleton, Allison A; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F; Anastasiu, Doru; Gurzau, Eugen S

    2017-04-01

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiṣ County, Romania. Women (n=94) with planned pregnancies of 5-20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

    International Nuclear Information System (INIS)

    Susko, Michele L.; Bloom, Michael S.; Neamtiu, Iulia A.; Appleton, Allison A.; Surdu, Simona; Pop, Cristian; Fitzgerald, Edward F.; Anastasiu, Doru

    2017-01-01

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did

  18. Low-level arsenic exposure via drinking water consumption and female fecundity - A preliminary investigation

    Energy Technology Data Exchange (ETDEWEB)

    Susko, Michele L. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Bloom, Michael S., E-mail: mbloom@albany.edu [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Neamtiu, Iulia A. [Health Department, Environmental Health Center, Cluj-Napoca (Romania); IMOGEN Research Institute, Cluj-Napoca (Romania); Appleton, Allison A. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Surdu, Simona [Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Pop, Cristian [Physico-chemical and Biotoxicological Analysis Laboratory, Environmental Health Center, Cluj-Napoca (Romania); Cluj School of Public Health - College of Political, Administrative and Communication Sciences, Babeș-Bolyai University, Cluj-Napoca (Romania); Faculty of Environmental Science and Engineering, Babeș-Bolyai University, Cluj-Napoca (Romania); Fitzgerald, Edward F. [Department of Epidemiology and Biostatistics, University at Albany, State University of New York, Rensselaer, New York (United States); Department of Environmental Health Sciences, University at Albany, State University of New York, Rensselaer, New York (United States); Anastasiu, Doru [University of Medicine and Pharmacy “Victor Babeș”, Timișoara (Romania); Obstetrics and Gynecology Department of the Emergency County Hospital, Timișoara (Romania); and others

    2017-04-15

    High level arsenic exposure is associated with reproductive toxicity in experimental and observational studies; however, few data exist to assess risks at low levels. Even less data are available to evaluate the impact of low level arsenic exposure on human fecundity. Our aim in this pilot study was a preliminary evaluation of associations between low level drinking water arsenic contamination and female fecundity. This retrospective study was conducted among women previously recruited to a hospital-based case-control study of spontaneous pregnancy loss in Timiá¹£ County, Romania. Women (n=94) with planned pregnancies of 5–20 weeks gestation completed a comprehensive physician-administered study questionnaire and reported the number of menstrual cycles attempting to conceive as the time to pregnancy (TTP). Drinking water samples were collected from residential drinking water sources and we determined arsenic levels using hydride generation-atomic absorption spectrometry (HG-AAS). Multivariable Cox-proportional hazards regression with Efron approximation was employed to evaluate TTP as a function of drinking water arsenic concentrations among planned pregnancies, adjusted for covariates. There was no main effect for drinking water arsenic exposure, yet the conditional probability for pregnancy was modestly lower among arsenic exposed women with longer TTPs, relative to women with shorter TTPs, and relative to unexposed women. For example, 1 µg/L average drinking water arsenic conferred 5%, 8%, and 10% lower likelihoods for pregnancy in the 6th, 9th, and 12th cycles, respectively (P=0.01). While preliminary, our results suggest that low level arsenic contamination in residential drinking water sources may further impair fecundity among women with longer waiting times; however, this hypothesis requires confirmation by a future, more definitive study. - Highlights: • We assessed low level drinking water arsenic as a predictor of fecundability. • Arsenic did

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  20. Low-level exposure to organophosphate pesticides leads to restrictive lung dysfunction.

    Science.gov (United States)

    Peiris-John, Roshini Janet; Ruberu, Dawala Kusuma; Wickremasinghe, Ananda Rajitha; van-der-Hoek, Wim

    2005-10-01

    Apart from symptomology, there are very few reports on lung function following exposure to low levels of organophosphate (OP) pesticides in man. Twenty-five occupationally exposed farmers and 22 environmentally exposed freshwater fishermen were evaluated between and during OP spray seasons. Forty marine fishermen living away from agricultural areas were recruited as a control group. Forced vital capacity (FVC) and forced expiratory volume in the first second (FEV(1)) were measured by spirometry. Haemoglobin corrected erythrocyte acetylcholinesterase (AChE) levels were measured during and between (baseline estimation) spray seasons using a portable WHO-approved Test-mate system (EQM Research, Ohio). FVC ratio was lower in the farmers as compared to the controls (P<0.001) between exposure seasons. In the farmers, FVC ratio decreased further during the exposure season (P=0.023). FEV(1) was lower in the farmers as compared to the controls in both periods (P<0.05). In the fishermen, the decrease in ratios of FVC and FEV(1) following exposure to pesticides was not significant. FEV(1)/FVC ratios were similar in the three groups between (P=0.988) and during (P=0.159) exposure periods. Following exposure to OPs, AChE levels dropped 12.75% in the farmers (P<0.001) and 5.62% in the freshwater fishermen (P=0.001). Occupational exposure to OP results in restrictive lung dysfunction, a phenomenon not observed following environmental exposure.

  1. Aspects of research on effects of population exposed to low level radiation in China

    International Nuclear Information System (INIS)

    Wei, L.

    1992-01-01

    Research works of epidemiology and experimental biology concerning health effects on populations exposed to low level ionizing radiation in China have been reviewed, with emphasis on the studies of mortality of malignancies and prevalence of hereditary diseases in a high background radiation area (HBRA) (radiation level is about three times of the control area of normal background CA), where the inhabitant families have lived for many generations. About one million person-years in HBRA and as many in CA were observed for cancer mortality. Statistical analysis showed that no difference was found either in mortality of all cancers or leukemias between HBRA and CA. The incidence of Down Syndrome in HBRA was within the range of spontaneous incidence and dependent on age of maternity. The characteristics of adaptive response induced by low level irradiation in humans as well as in experimental animal lymphocytes observed in Chinese laboratories are also discussed in this presentation

  2. Radiation exposure

    International Nuclear Information System (INIS)

    Dalton, L.K.

    1991-01-01

    The book gives accounts of some social and environmental impacts of the developing radiation industries, including the experiences of affected communities and individuals. Its structure is based on a division which has been made between nuclear and non-nuclear radiation sources, because they create distinctly different problems for environmental protection and so for public health policy. The emissions from electronic and electrical installations - the non-nuclear radiations - are dealt with in Part I. Emissions from radioactive substances - the nuclear radiations - are dealt with in Part II. Part III is for readers who want more detailed information about scientific basis of radiation-related biological changes and their associated health effects. 75 refs., 9 tabs., 7 figs., ills

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

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1979-01-01

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

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

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1979-01-01

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

  5. Responses of Cell Renewal Systems to Long-term Low-Level Radiation Exposure: A Feasibility Study Applying Advanced Molecular Biology Techniques on Available Histological and Cytological Material of Exposed Animals and Men

    Energy Technology Data Exchange (ETDEWEB)

    Fliedner Theodor M.; Feinendegen Ludwig E.; Meineke Viktor; Fritz Thomas E.

    2005-02-28

    First results of this feasibility study showed that evaluation of the stored material of the chronically irradiated dogs with modern molecular biological techniques proved to be successful and extremely promising. Therefore an in deep analysis of at least part of the huge amount of remaining material is of outmost interest. The methods applied in this feasibility study were pathological evaluation with different staining methods, protein analysis by means of immunohistochemistry, strand break analysis with the TdT-assay, DNA- and RNA-analysis as well as genomic examination by gene array. Overall more than 50% of the investigated material could be used. In particular the results of an increased stimulation of the immune system within the dogs of the 3mSv group as both compared to the control and higher dose groups gives implications for the in depth study of the cellular events occurring in context with low dose radiation. Based on the findings of this study a further evaluation and statistically analysis of more material can help to identify promising biomarkers for low dose radiation. A systematic evaluation of a correlation of dose rates and strand breaks within the dog tissue might moreover help to explain mechanisms of tolerance to IR. One central problem is that most sequences for dog specific primers are not known yet. The discovery of the dog genome is still under progress. In this study the isolation of RNA within the dog tissue was successful. But up to now there are no gene arrays or gene chips commercially available, tested and adapted for canine tissue. The uncritical use of untested genomic test systems for canine tissue seems to be ineffective at the moment, time consuming and ineffective. Next steps in the investigation of genomic changes after IR within the stored dog tissue should be limited to quantitative RT-PCR of tested primer sequences for the dog. A collaboration with institutions working in the field of the discovery of the dog genome could

  6. Responses of Cell Renewal Systems to Long-term Low-Level Radiation Exposure: A Feasibility Study Applying Advanced Molecular Biology Techniques on Available Histological and Cytological Material of Exposed Animals and Men

    International Nuclear Information System (INIS)

    Fliedner Theodor M.; Feinendegen Ludwig E.; Meineke Viktor; Fritz Thomas E.

    2005-01-01

    First results of this feasibility study showed that evaluation of the stored material of the chronically irradiated dogs with modern molecular biological techniques proved to be successful and extremely promising. Therefore an in deep analysis of at least part of the huge amount of remaining material is of outmost interest. The methods applied in this feasibility study were pathological evaluation with different staining methods, protein analysis by means of immunohistochemistry, strand break analysis with the TdT-assay, DNA- and RNA-analysis as well as genomic examination by gene array. Overall more than 50% of the investigated material could be used. In particular the results of an increased stimulation of the immune system within the dogs of the 3mSv group as both compared to the control and higher dose groups gives implications for the in depth study of the cellular events occurring in context with low dose radiation. Based on the findings of this study a further evaluation and statistically analysis of more material can help to identify promising biomarkers for low dose radiation. A systematic evaluation of a correlation of dose rates and strand breaks within the dog tissue might moreover help to explain mechanisms of tolerance to IR. One central problem is that most sequences for dog specific primers are not known yet. The discovery of the dog genome is still under progress. In this study the isolation of RNA within the dog tissue was successful. But up to now there are no gene arrays or gene chips commercially available, tested and adapted for canine tissue. The uncritical use of untested genomic test systems for canine tissue seems to be ineffective at the moment, time consuming and ineffective. Next steps in the investigation of genomic changes after IR within the stored dog tissue should be limited to quantitative RT-PCR of tested primer sequences for the dog. A collaboration with institutions working in the field of the discovery of the dog genome could

  7. Low level prenatal exposure to methylmercury disrupts neuronal migration in the developing rat cerebral cortex

    International Nuclear Information System (INIS)

    Guo, Bao-Qiang; Yan, Chong-Huai; Cai, Shi-Zhong; Yuan, Xiao-Bing; Shen, Xiao-Ming

    2013-01-01

    Highlights: ► Low level MeHg exposure causes migratory defect of rat cerebrocortical neurons. ► The migration defect is due to the impact of MeHg on the neuronal migration itself. ► Rho GTPases seem to be involved in MeHg-induced disruption of neuronal migration. -- Abstract: We determined the effects of low-level prenatal MeHg exposure on neuronal migration in the developing rat cerebral cortex using in utero electroporation. We used offspring rats born to dams that had been exposed to saline or various doses of MeHg (0.01 mg/kg/day, 0.1 mg/kg/day, and 1 mg/kg/day) from gestational day (GD) 11–21. Immunohistochemical examination of the brains of the offspring was conducted on postnatal day (PND) 0, PND3, and PND7. Our results showed that prenatal exposure to low levels of MeHg (0.1 mg/kg/day or 1 mg/kg/day) during the critical stage in neuronal migration resulted in migration defects of the cerebrocortical neurons in offspring rats. Importantly, our data revealed that the abnormal neuronal distribution induced by MeHg was not caused by altered proliferation of neural progenitor cells (NPCs), induction of apoptosis of NPCs and/or newborn neurons, abnormal differentiation of NPCs, and the morphological changes of radial glial scaffold, indicating that the defective neuronal positioning triggered by exposure to low-dose of MeHg is due to the impacts of MeHg on the process of neuronal migration itself. Moreover, we demonstrated that in utero exposure to low-level MeHg suppresses the expression of Rac1, Cdc42, and RhoA, which play key roles in the migration of cerebrocortical neurons during the early stage of brain development, suggesting that the MeHg-induced migratory disturbance of cerebrocortical neurons is likely associated with the Rho GTPases signal pathway. In conclusion, our results provide a novel perspective on clarifying the mechanisms underlying the impairment of neuronal migration induced by MeHg

  8. [Assessment for effect of low level lead-exposure on neurobehavior in workers of printing house].

    Science.gov (United States)

    Niu, Q; Dai, F; Chen, Y

    1998-11-30

    WHO Neurobehavioral Core Test Battery (NCTB) was conducted among 28 lead-exposed workers (mean age 24.84, SD2.85) in printing house and 46 controls (mean age 22.78, SD1.45), in order to assess whether low level lead exposure may be related to neurobehavioral dysfunction. The items of test were: 1. Profile of mood state(POMS), (2) Simple reaction time, (3) Digit span, (4) Santa Anna manual dexterity, (5) Digit simbol, (6) Benton visual retention; and Prusuit aiming test. In all the NCTB test values, there was no significant difference between two groups. Multiple stepwise regression analysis shows that exposure duration is related to neurobehavior scores. Mild lead exposure may affect neurobehavior in some degree but not significant.

  9. The effects of repeated low-level blast exposure on hearing in marines

    Directory of Open Access Journals (Sweden)

    Lina R Kubli

    2017-01-01

    Full Text Available Background: The study evaluates a group of Military Service Members specialized in blast explosive training called “Breachers” who are routinely exposed to multiple low-level blasts while teaching breaching at the U.S. Marine Corps in Quantico Virginia. The objective of this study was to determine if there are any acute or long-term auditory changes due to repeated low-level blast exposures used in training. The performance of the instructor group “Breachers” was compared to a control group, “Engineers”. Methods: A total of 11 Breachers and four engineers were evaluated in the study. The participants received comprehensive auditory tests, including pure-tone testing, speech-in-noise (SIN measures, and central auditory behavioral and objective tests using early and late (P300 auditory evoked potentials over a period of 17 months. They also received shorter assessments immediately following the blast-exposure onsite at Quantico. Results: No acute or longitudinal effects were identified. However, there were some interesting baseline effects found in both groups. Contrary to the expected, the onsite hearing thresholds and distortion product otoacoustic emissions were slightly better at a few frequencies immediately after blast-exposure than measurements obtained with the same equipment weeks to months after each blast-exposure. Conclusions: To date, the current study is the most comprehensive study that evaluates the long-term effects of blast-exposure on hearing. Despite extensive testing to assess changes, the findings of this study suggest that the levels of current exposures used in this military training environment do not seem to have an obvious deleterious effect on hearing.

  10. Occurrence of 210Po and Biological Effects of Low-Level Exposure: The Need for Research

    Science.gov (United States)

    Wiemels, Joseph L.

    2012-01-01

    Background: Polonium-210 (210Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of 210Po are common in sediments, and segments of the public may be chronically exposed to low levels of 210Po in drinking water or in food products from animals raised in contaminated areas. Objectives: We summarized information on the environmental behavior, biokinetics, and toxicology of 210Po and identified the need for future research. Methods: Potential linkages between environmental exposure to 210Po and human health effects were identified in a literature review. Discussion: 210Po accumulates in the ovaries where it kills primary oocytes at low doses. Because of its radiosensitivity and tendency to concentrate 210Po, the ovary may be the critical organ in determining the lowest injurious dose for 210Po. 210Po also accumulates in the yolk sac of the embryo and in the fetal and placental tissues. Low-level exposure to 210Po may have subtle, long-term biological effects because of its tropism towards reproductive and embryonic and fetal tissues where exposure to a single alpha particle may kill or damage critical cells. 210Po is present in cigarettes and maternal smoking has several effects that appear consistent with the toxicology of 210Po. Conclusions: Much of the important biological and toxicological research on 210Po is more than four decades old. New research is needed to evaluate environmental exposure to 210Po and the biological effects of low-dose exposure to it so that public health officials can develop appropriate mitigation measures where necessary. PMID:22538346

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

    International Nuclear Information System (INIS)

    Higson, D.J.

    2006-01-01

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

  12. Health effects of low level radiation in shipyard workers. Progress report

    International Nuclear Information System (INIS)

    1981-09-01

    In order to determine the effects of low-level doses of radiation it was necessary to define an adequate population, to gather and collate data relating to this population and to organize this data in such a manner as to render it suitable for analysis. We have completed much of the groundwork, including the development of data collection systems and the establishment of liaisons with public and private data resources for ascertaining vital status and current address. The major tasks which we now face are two fold: (1) to determine the cause of death for deceased members of the population, and (2) to locate and secure information (occupational, medical and smoking histories) from living members of the population. Once these tasks have been completed we can undertake an analysis of this information to assess the risks of low-level doses of radiation and establish mechanisms through which this population can be followed prospectively

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

    International Nuclear Information System (INIS)

    Arkhipchuk, V.V.

    1995-01-01

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

  14. Relationship of cumulative low-level dose of ionizing radiation on human eye lens and occurrence of cataract

    International Nuclear Information System (INIS)

    Deolalikar, Raghavendra

    2015-01-01

    International Commission on Radiological Protection (ICRP), issued a statement on Tissue Reaction, lowering the equivalent dose limit for eye lens for occupational exposure to 20 mSv per year. With a view to determine presence of any relationship between the cumulative low-level occupational radiation dose to the eye lens and occurrence of cataract, departmental records of the annual medical examination of employees of Narora Atomic Power Plant were examined along with the NAPS eye camps and surgical records of the employees. Analysis of the data showed no demonstrable definite relationship between the two. The analysis of the data and the observations are discussed in this paper. (author)

  15. Low-level effects

    International Nuclear Information System (INIS)

    Devine, R.T.; Chaput, R.L.

    1987-01-01

    Risk assignments can be made to given practices involving exposure to radiation, because sufficient data are available for the effects of high-dose, low-LET radiation and because sufficient exists in the methods of extrapolation to low doses and low dose rates. The confidence in the extrapolations is based on the fact that the risk is not expected to be overestimated, using the assumptions made (as opposed to the possibility that the extrapolations represent an accurate estimate of the risk). These risk estimates have been applied to the selection of permissible exposure levels, to show that various amounts of radiation involve no greater risk to the worker than the risk expected in another industry that is generally considered safe. The setting of standards for protection from exposure to low levels of ionizing radiation is made by expert committees at the national and international levels who weigh social factors as well as scientific factors. Data on low-level effects may be applied when assigning a ''probability of causation'' to a certain exposure of radiation. This has become a prominent method for arriving at an equitable award for damages caused by such exposure. The generation of these tables requires as many (if not more) social and political considerations as does the setting up of protection criteria. It is impossible to extract a purely scientific conclusion solely from the protection standards and other legal decisions. Sufficient information exists on low-LET radiation that safety standards for exposure can be rationally (if not scientifically) agreed upon

  16. Reaction of the immune system to low-level RF/MW exposures

    International Nuclear Information System (INIS)

    Szmigielski, Stanislaw

    2013-01-01

    Radiofrequency (RF) and microwave (MW) radiation have been used in the modern world for many years. The rapidly increasing use of cellular phones in recent years has seen increased interest in relation to the possible health effects of exposure to RF/MW radiation. In 2011 a group of international experts organized by the IARC (International Agency for Research on Cancer in Lyon) concluded that RF/MW radiations should be listed as a possible carcinogen (group 2B) for humans. The incomplete knowledge of RF/MW-related cancer risks has initiated searches for biological indicators sensitive enough to measure the “weak biological influence” of RF/MWs. One of the main candidates is the immune system, which is able to react in a measurable way to discrete environmental stimuli. In this review, the impacts of weak RF/MW fields, including cell phone radiation, on various immune functions, both in vitro and in vivo, are discussed. The bulk of available evidence clearly indicates that various shifts in the number and/or activity of immunocompetent cells are possible, however the results are inconsistent. For example, a number of lymphocyte functions have been found to be enhanced and weakened within single experiments based on exposure to similar intensities of MW radiation. Certain premises exist which indicate that, in general, short-term exposure to weak MW radiation may temporarily stimulate certain humoral or cellular immune functions, while prolonged irradiation inhibits the same functions

  17. Reaction of the immune system to low-level RF/MW exposures

    Energy Technology Data Exchange (ETDEWEB)

    Szmigielski, Stanislaw, E-mail: szmigielski@wihe.waw.pl

    2013-06-01

    Radiofrequency (RF) and microwave (MW) radiation have been used in the modern world for many years. The rapidly increasing use of cellular phones in recent years has seen increased interest in relation to the possible health effects of exposure to RF/MW radiation. In 2011 a group of international experts organized by the IARC (International Agency for Research on Cancer in Lyon) concluded that RF/MW radiations should be listed as a possible carcinogen (group 2B) for humans. The incomplete knowledge of RF/MW-related cancer risks has initiated searches for biological indicators sensitive enough to measure the “weak biological influence” of RF/MWs. One of the main candidates is the immune system, which is able to react in a measurable way to discrete environmental stimuli. In this review, the impacts of weak RF/MW fields, including cell phone radiation, on various immune functions, both in vitro and in vivo, are discussed. The bulk of available evidence clearly indicates that various shifts in the number and/or activity of immunocompetent cells are possible, however the results are inconsistent. For example, a number of lymphocyte functions have been found to be enhanced and weakened within single experiments based on exposure to similar intensities of MW radiation. Certain premises exist which indicate that, in general, short-term exposure to weak MW radiation may temporarily stimulate certain humoral or cellular immune functions, while prolonged irradiation inhibits the same functions.

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

    International Nuclear Information System (INIS)

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

    1984-05-01

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

  19. Radiation and cancer in Wales. The biological consequences of low-level radiation

    International Nuclear Information System (INIS)

    Busby, C.C.

    1994-01-01

    recent developments have made necessary the revision of the original booklet. Chapter 1 of this second edition is an updating of the first edition. Chapter 2 covers in more detail the effects of low-level radiation in Wales, including discussion of the increases in bone cancer and the effects of Chernobyl. The second-event theory is reproduced as Chapter 3, which also includes a copy of the original paper to the International Journal of Radiation Biology and some of the responses which have been made to it, both by the referees for this journal and other authorities in the field

  20. Radiation and cancer in Wales. The biological consequences of low-level radiation

    Energy Technology Data Exchange (ETDEWEB)

    Busby, C C

    1994-07-01

    recent developments have made necessary the revision of the original booklet. Chapter 1 of this second edition is an updating of the first edition. Chapter 2 covers in more detail the effects of low-level radiation in Wales, including discussion of the increases in bone cancer and the effects of Chernobyl. The second-event theory is reproduced as Chapter 3, which also includes a copy of the original paper to the International Journal of Radiation Biology and some of the responses which have been made to it, both by the referees for this journal and other authorities in the field.

  1. Early renal effects of occupational exposure to low-level hexavalent chromium

    Energy Technology Data Exchange (ETDEWEB)

    Nagaya, Teruo (Dept. of Public Health, Gifu Univ. School of Medicine, Tsukasa-machi (Japan)); Ishikawa, Noriko (Occupational Hygiene Center, Gifu Labour Standards Association, Hikie (Japan)); Hata, Hideo (Occupational Hygiene Center, Gifu Labour Standards Association, Hikie (Japan)); Takahashi, Akemi (Gifu-shi Central Public Health Center, Miyako-dori (Japan)); Yoshida, Izumi (Gifu-shi Central Public Health Center, Miyako-dori (Japan)); Okamoto, Yoshinari (Gifu-shi Central Public Health Center, Miyako-dori (Japan))

    1994-05-01

    To detect early renal effects of occupational exposure to hexavalent chromium (Cr), urinary total proteins (U-TP), urinary albumin (U-Alb) and urinary retinol-binding protein (U-RBP) were determined in 166 male Cr platers and 106 male controls. The mean employment time in Cr plating for the platers was 12.6 years. Urinary Cr (U-Cr), which was determined as an index of Cr exposure, ranged from ''not detected'' to 19.91 [mu]g/g creatinine in the platers. The U-Cr level was lower than those in other previous studies. Age-adjusted U-TP, U-Alb or U-RBP levels were not different between the platers and the controls. In the platers, a significant positive correlation was found between age-adjusted U-TP and U-Cr, but U-Cr had no significant relation to age-adjusted U-Alb or U-RBP level. Employment time had no effect on any age-adjusted urinary proteins. The Cr exposure may have been too low to induce definite renal dysfunction. Early renal effects of low-level Cr exposure may be mild, and may not be specific to renal function. (orig.)

  2. Chronic exposure to low-levels of lead in the rat: biochemical and behavioural changes

    International Nuclear Information System (INIS)

    Rossouw, J.

    1987-01-01

    The prevalence of lead in the environment is a cause of continuing toxicology concern and there have been numerous human and animal studies to examine more thoroughly the possible consequences of exposure to this ecotoxicant. Because lead is highly toxic to the developing central nervous system, increasing concern over the rise in the lead content in the environment has been expressed. These concerns seem appropriate since more recent clinical studies have shown that prolonged exposure of children to so called 'subclinical' concentrations of lead may be associated with behavioural disorders, learning disabilities and mental retardation. Moreover, animal studies have shown that chronic perinatal low-level lead exposure elicits alterations in both learned and spontaneous behavioural patterns in the absence of typical outward signs of lead-induced neurological toxicity. No study however could relate behavioural changes to specific alterations in neurochemisty. The aim of this study was therefore to expose rats, in different stages of their development, to low-levels of lead in order to induce behavioural disorders and correlate latter with possible neurochemical changes. In accordance with the general aims of the study, the structuring of the thesis is as follows: (a) a discussion of the neurotransmitters in the brain in order to describe the different systems which have been investigated; (b) a review of appropriate literature regarding the kinetics, toxodynamics and neurotoxicity of lead and (c) a summary of the methods employed in the study. The following results are presented: (d) the effects of lead treatment on physical development of the rats; (e) the induction of behavioural supersensitivity and (f) the effects lead has on central receptors

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  4. Effects of low-level sarin and cyclosarin exposure on hippocampal subfields in Gulf War Veterans.

    Science.gov (United States)

    Chao, Linda L; Kriger, Stephen; Buckley, Shannon; Ng, Peter; Mueller, Susanne G

    2014-09-01

    More than 100,000 US troops were potentially exposed to chemical warfare agents sarin (GB) and cyclosarin (GF) when an ammunition dump at Khamisiyah, Iraq was destroyed during the 1991 Gulf War (GW). We previously reported reduced hippocampal volume in GW veterans with suspected GB/GF exposure relative to matched, unexposed GW veterans estimated from 1.5T magnetic resonance images (MRI). Here we investigate, in a different cohort of GW veterans, whether low-level GB/GF exposure is associated with structural alterations in specific hippocampal subfields, estimated from 4T MRI. The Automatic Segmentation of Hippocampal Subfields (ASHS) technique was used to quantify CA1, CA2, CA3 and dentate gyrus (DG), and subiculum (SUB) subfields volumes from high-resolution T2-weighted images acquired on a 4T MR scanner in 56 GW veterans with suspected GB/GF exposure and 56 "matched" unexposed GW veterans (mean age 49±7 years). GB/GF exposed veterans had smaller CA2 (p=0.003) and CA3/DG (p=0.01) subfield volumes compared to matched, unexposed GW veterans. There were no group difference in total hippocampal volume, quantified with FreeSurfer, and no dose-response relationship between estimated levels of GB/GF exposure and total hippocampal or subfield volume. These findings extend our previous report of structural alterations in the hippocampi of GW veterans with suspected GB/GF exposure to volume changes in the CA2, CA3, and DG hippocampal subfields in a different cohort of GW veterans with suspected GB/GF exposure. Published by Elsevier B.V.

  5. Effects of low-level sarin and cyclosarin exposure on hippocampal microstructure in Gulf War Veterans.

    Science.gov (United States)

    Chao, Linda L; Zhang, Yu

    2018-05-04

    In early March 1991, shortly after the end of the Gulf War (GW), a munitions dump was destroyed at Khamisiyah, Iraq. Later, in 1996, the dump was found to have contained the organophosphorus (OP) nerve agents sarin and cyclosarin. We previously reported evidence of smaller hippocampal volumes in GW veterans with predicted exposure to the Khamisiyah plume compared to unexposed GW veterans. To investigate whether these macroscopic hippocampal volume changes are accompanied by microstructural alterations in the hippocampus, the current study acquired diffusion-tensor imaging (DTI), T1-, and T2-weighted images from 170 GW veterans (mean age: 53 ± 7 years), 81 of whom had predicted exposure to the Khamisiyah plume according to Department of Defense (DOD) plume modeling. We examined fractional anisotropy (FA), mean diffusivity (MD), and grey matter (GM) density from a hippocampal region of interest (ROI). Results indicate that, even after accounting for total hippocampal GM density (or hippocampal volume), age, sex, apolipoprotein ε4 genotype, and potential confounding OP pesticide exposures, hippocampal MD significantly predicted Khamisiyah exposure status (model p = 0.005, R 2  = 0.215, standardized coefficient β = 0.26, t = 2.85). Hippocampal MD was also inversely correlated with verbal memory learning performance in the entire study sample (p = 0.001). There were no differences in hippocampal FA or GM density; however, veterans with predicted Khamisiyah exposure had smaller hippocampal volumes compared to unexposed veterans. Because MD is sensitive to general microstructural disruptions that lead to increased extracellular spaces due to neuronal death, inflammation and gliosis, and/or to axonal loss or demyelination, these findings suggest that low-level exposure to the Khamisiyah plume has a detrimental, lasting effects on both macro- and micro-structure of the hippocampus. Copyright © 2018. Published by Elsevier Inc.

  6. Health effects in women exposed to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1982-06-01

    There are three delayed health effects of radiation which appear at the present time to have importance to women in radiation protection. These are: (1) the probability of cancer-induction at low doses and low-dose rates; (2) the consideration of those cancers in women, notably the breast and the thyroid, attributable to radiation exposure; and (3) the probability of induction of developmental abnormalities in the newborn following low-dose exposure in utero. The bases for the concern over these effects are discussed

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  8. Low-level lead exposure effects on spatial reference memory and working memory in rats

    Institute of Scientific and Technical Information of China (English)

    Xinhua Yang; Ping Zhou; Yonghui Li

    2009-01-01

    BACKGROUND: Studies have demonstrated that lead exposure can result in cognitive dysfunction and behavior disorders. However, lead exposure impairments vary under different experimental conditions.OBJECTIVE: To detect changes in spatial learning and memory following low-level lead exposure in rats, in Morris water maze test under the same experimental condition used to analyze lead exposure effects on various memory types and learning processes.DESIGN AND SETTING: The experiment was conducted at the Animal Laboratory, Institute of Psychology, Chinese Academy of Science between February 2005 and March 2006. One-way analysis of variance (ANOVA) and behavioral observations were performed.MATERIALS: Sixteen male, healthy, adult, Sprague Dawley rats were randomized into normal control and lead exposure groups (n = 8).METHODS: Rats in the normal control group were fed distilled water, and those in the lead exposure group were fed 250 mL of 0.05% lead acetate once per day. At day 28, all rats performed the Morris water maze test, consisting of four phases: space navigation, probe test, working memory test, and visual cue test.MAIN OUTCOME MEASURES: Place navigation in the Morris water maze was used to evaluate spatial learning and memory, probe trials for spatial reference memory, working memory test for spatial working memory, and visual cue test for non-spatial cognitive function. Perkin-Elmer Model 300 Atomic Absorption Spectrometer was utilized to determine blood lead levels in rats.RESULTS: (1) In the working memory test, the time to reach the platform remained unchanged between the control and lead exposure groups (F(1,1) = 0.007, P = 0.935). A visible decrease in escape latencies was observed in each group (P = 0.028). However, there was no significant difference between the two groups (F(1,1) = 1.869, P = 0.193). The working memory probe test demonstrated no change between the two groups in the time spent in the target quadrant during the working memory probe test

  9. Cadmium toxicity studies under long term-low level exposure (LLE) conditions. I

    International Nuclear Information System (INIS)

    Sabbioni, E.; Marafante, E.; Amantini, L.; Ubertalli, L.; Pietra, R.

    1978-01-01

    A long term-low level exposure (LLE) experiment was conducted on rats to determine the metabolic patterns for realistic dietary levels of cadmium. Male rats fed with 61 ppb of cadmium ad libitum, 50 labelled with 109 Cd radiotracer as cadmium chloride via drinking mineral water and 11 unlabelled via food for 2 years. The diet was characterized in its metal content by neutron activation analysis to obtain the total dietary intake of different elements. The kidney was found to be the tissue with the major concentration of cadmium which accumulated continuously during the experiment. The variation of the accumulation pattern of Cd concentration in the liver and intestine indicated an initial rapid increase of Cd during the first 100 days. After this period an apparent equilibrium was attained in both these tissues until the end of the study. The intracellular distribution of cadmium in kidneys, liver, intestine and pancreas were similar, the cytosol fractions containing about 80% of the cellular cadmium. Dialysis experiments indicated that significant amounts of cadmium were able to be associated with cellular organelles, the mitochondria representing the most important organelle capable of binding cadmium. The cytoplasmatic Cd-profiles obtained at various stages of the experiment showed that the metal was only bound to a low-molecular-weight component, cadmium-binding protein (CdBP), which represents the specific cellular-binding component for cadmium under the long term-low level exposure (LLE) conditions. No significant variations in the concentrations of the elements in different organs were observed in animals supplemented with 109 Cd in respect to 109 Cd untreated controls. (Auth.)

  10. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment

    International Nuclear Information System (INIS)

    Rose, K.S.B.

    1988-01-01

    In this report, the health effects of low-level doses of radiation are considered by reference to published epidemiological surveys. The work was carried out with three objectives in mind: 1. to provide a comprehensive and critical review of the subject; 2. to seek consistent indications of particular health effects by collating results and comparing with those from surveys at moderate-level doses; 3. to provide an authoritative view on the epidemiology of low-level radiation-induced health effects. Vol E (DRAFT A) is appended and contains group collation tables. Epidemiological surveys can be conveniently divided into four classes (A, B, C, D) according to the phase of life when irradiation occurs or the effect is diagnosed. The first of the classes (A) is addressed here; this class is concerned with possible effects arising from radiation received by a parent before conception. Possible effects of preconception irradiation were identified under four broad groupings. These are Down's syndrome, ''Indicators of Reproductive Damage'' (mainly Primary Sterility, Congenital Abnormalities, Sex Ratio, Fetal Mortality, Infant Mortality), Childhood Malignancies, and Chromosomal Changes in Abortuses. Information about each survey, and comparisons with results from moderate-level dose surveys, are contained in synopses that are set out in the Appendix. (author)

  11. Early life low-level cadmium exposure is positively associated with increased oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Kippler, Maria [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Bakhtiar Hossain, Mohammad [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh); Department of Laboratory Medicine, Section of Occupational and Environmental Medicine, Lund University, Lund (Sweden); Lindh, Christian [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh); Moore, Sophie E. [MRC Keneba, MRC Laboratories (Gambia); Kabir, Iqbal [Department of Laboratory Medicine, Section of Occupational and Environmental Medicine, Lund University, Lund (Sweden); Vahter, Marie [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Broberg, Karin, E-mail: karin.broberg_palmgren@med.lu.se [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh)

    2012-01-15

    Environmental exposure to cadmium (Cd) is known to induce oxidative stress, a state of imbalance between the production of reactive oxygen species (ROS) and the ability to detoxify them, in adults. However, data are lacking on potential effects in early-life. We evaluated urinary concentrations of 8-oxo-7,8-dihydro-2 Prime -deoxyguanosine (8-oxodG), a recognized marker of oxidative DNA damage, in relation to Cd exposure in 96 predominantly breast-fed infants (11-17 weeks of age) in rural Bangladesh. Urinary 8-oxodG was measured using liquid chromatography tandem mass spectrometry and Cd in urine and breast milk by inductively coupled plasma mass spectrometry. Median concentration of 8-oxodG was 3.9 nmol/L, urinary Cd 0.30 {mu}g/L, and breast-milk Cd 0.13 {mu}g/L. In linear regression analyses, urinary 8-oxodG was positively associated with Cd in both urine (p=0.00067) and breast milk (p=0.0021), and negatively associated with body weight (kg; p=0.0041). Adjustment for age, body weight, socio-economic status, urinary arsenic, as well as magnesium, calcium, and copper in breast milk did not change the association between Cd exposure and urinary 8-oxodG. These findings suggest that early-life low-level exposure to Cd via breast milk induces oxidative stress. Further studies are warranted to elucidate whether this oxidative stress is associated with impaired child health and development.

  12. Early life low-level cadmium exposure is positively associated with increased oxidative stress

    International Nuclear Information System (INIS)

    Kippler, Maria; Bakhtiar Hossain, Mohammad; Lindh, Christian; Moore, Sophie E.; Kabir, Iqbal; Vahter, Marie; Broberg, Karin

    2012-01-01

    Environmental exposure to cadmium (Cd) is known to induce oxidative stress, a state of imbalance between the production of reactive oxygen species (ROS) and the ability to detoxify them, in adults. However, data are lacking on potential effects in early-life. We evaluated urinary concentrations of 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG), a recognized marker of oxidative DNA damage, in relation to Cd exposure in 96 predominantly breast-fed infants (11–17 weeks of age) in rural Bangladesh. Urinary 8-oxodG was measured using liquid chromatography tandem mass spectrometry and Cd in urine and breast milk by inductively coupled plasma mass spectrometry. Median concentration of 8-oxodG was 3.9 nmol/L, urinary Cd 0.30 μg/L, and breast-milk Cd 0.13 μg/L. In linear regression analyses, urinary 8-oxodG was positively associated with Cd in both urine (p=0.00067) and breast milk (p=0.0021), and negatively associated with body weight (kg; p=0.0041). Adjustment for age, body weight, socio-economic status, urinary arsenic, as well as magnesium, calcium, and copper in breast milk did not change the association between Cd exposure and urinary 8-oxodG. These findings suggest that early-life low-level exposure to Cd via breast milk induces oxidative stress. Further studies are warranted to elucidate whether this oxidative stress is associated with impaired child health and development.

  13. Family environmental and dietary implications for low-level prenatal lead exposure in Wujiang City, China.

    Science.gov (United States)

    Yan, Jin; Gao, Zhenyan; Wang, Ju; Ma, Wenjuan; Ying, Xiaolan; Zhou, Cancan; Yan, Chonghuai

    2018-05-01

    To explore the potential environmental and dietary factors during pregnancy affecting low-level prenatal lead exposure, we conducted a longitudinal study in Wujiang City, China. A total of 1976 mother-infant pairs were included from 2009 to 2010. An interviewed questionnaire was conducted and cord blood samples were collected. The geometric means of cord blood lead level was 30.3 μg/L (95% CI, 29.8-30.8) with 99.24% below 100 μg/L. Maternal age, passive smoking, and living in the countryside were significantly associated with cord blood lead concentrations. Multiple logistic models showed that some family environmental factors including using firewood and electricity as kitchen fuel were positively correlated with increased cord blood lead levels. Among dietary sources recorded in this study, meat consumption (> 3 times/week), fish consumption (1-3 times/week), vegetables consumption (> 1 times/day), and fruit intake (> 1 times/day) had inverse relationship with cord blood lead levels. In general, our findings may have important implications for family environmental and dietary direction during pregnancy to decrease prenatal lead exposure.

  14. The influence of low level γ-radiation on the development of bombyx Mori L

    International Nuclear Information System (INIS)

    Yusifov, N.I.; Kuzin, A.M.; Agaev, F.A.; Mozgovoj, E.G.; AN Azerbajdzhanskoj SSR, Baku. Sektor Radiatsionnykh Issledovanij)

    1988-01-01

    Chronic γ-irradiation of a grain at a dose-rate 100, 1000 and 4000 times as high as that of the natural radiation background significantly accelerates the development of Bombyx moti L. The caterpillar development may also be stimulated by a single exposure of the grain to 2 Gy radiation. The acceleration of the caterpillar growth promotes the increase in the cocoon weight and the raw-silk mass

  15. Radiation Exposure and Pregnancy

    Science.gov (United States)

    Fact Sheet Adopted: June 2010 Updated: June 2017 Health Physics Society Specialists in Radiation Safety Radiation Exposure and ... radiation and pregnancy can be found on the Health Physics Society " Ask the Experts" Web site. she should ...

  16. Association of hypothyroidism with low-level arsenic exposure in rural West Texas

    International Nuclear Information System (INIS)

    Gong, Gordon; Basom, Janet; Mattevada, Sravan; Onger, Frederick

    2015-01-01

    It has been reported recently that a higher airborne arsenic level was correlated with higher urinary arsenic concentration and lower serum thyroxin level among urban policemen and rural highway workmen in Italy. The current study was to determine whether exposure to low-level arsenic groundwater (2–22 µg/L) is associated with hypothyroidism among 723 participants (118 male and 267 female Hispanics; 108 male and 230 female non-Hispanic whites, NHW) living in rural West Texas counties. Arsenic and iodine levels in their groundwater used for drinking and or cooking were estimated by the inverse distance weighted (IDW) interpolation technique. Groundwater arsenic was ≥8 µg/L in 36% of the subjects' wells while iodine concentration was <1 µg/L in 91% of their wells. Logistic regression analysis showed that arsenic in groundwater ≥8 µg/L and cumulative arsenic exposure (groundwater arsenic concentration multiplied by the number of years living in the current address) but not groundwater iodine concentration were significant predictors for hypothyroidism among Hispanics (p<0.05) but not NHW after adjusting for covariates such as age, gender, annual household income and health insurance coverage. The ethnic difference may be due to a marginally higher percentage of Hispanics (p=0.0622) who lived in areas with groundwater arsenic ≥8 µg/L compared with NHW. The prevalence of hypothyroidism was significantly higher in Hispanics or NHW of this rural cohort than the national prevalence. Measures should be taken to reduce arsenic in drinking water in order to prevent hypothyroidism in rural areas. - Highlights: • We determined if arsenic exposure is associated with hypothyroidism in rural Texas. • Groundwater arsenic level is associated with hypothyroidism among Hispanics only. • The rate of hypothyroidism in rural Texas was higher than the US general population

  17. Association of hypothyroidism with low-level arsenic exposure in rural West Texas

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Gordon, E-mail: gordon.gong@ttuhsc.edu [F. Marie Hall Institute for Rural and Community Health, Texas Tech University Health Sciences Center, Lubbock, TX (United States); Basom, Janet [F. Marie Hall Institute for Rural and Community Health, Texas Tech University Health Sciences Center, Lubbock, TX (United States); Department of Family and Community Medicine, Texas Tech University Health Sciences Center, Lubbock, TX (United States); Mattevada, Sravan [Department of Internal Medicine, University of North Texas Health Science Center, Fort Worth, TX (United States); Onger, Frederick [Department of Family and Community Medicine, Texas Tech University Health Sciences Center, Lubbock, TX (United States)

    2015-04-15

    It has been reported recently that a higher airborne arsenic level was correlated with higher urinary arsenic concentration and lower serum thyroxin level among urban policemen and rural highway workmen in Italy. The current study was to determine whether exposure to low-level arsenic groundwater (2–22 µg/L) is associated with hypothyroidism among 723 participants (118 male and 267 female Hispanics; 108 male and 230 female non-Hispanic whites, NHW) living in rural West Texas counties. Arsenic and iodine levels in their groundwater used for drinking and or cooking were estimated by the inverse distance weighted (IDW) interpolation technique. Groundwater arsenic was ≥8 µg/L in 36% of the subjects' wells while iodine concentration was <1 µg/L in 91% of their wells. Logistic regression analysis showed that arsenic in groundwater ≥8 µg/L and cumulative arsenic exposure (groundwater arsenic concentration multiplied by the number of years living in the current address) but not groundwater iodine concentration were significant predictors for hypothyroidism among Hispanics (p<0.05) but not NHW after adjusting for covariates such as age, gender, annual household income and health insurance coverage. The ethnic difference may be due to a marginally higher percentage of Hispanics (p=0.0622) who lived in areas with groundwater arsenic ≥8 µg/L compared with NHW. The prevalence of hypothyroidism was significantly higher in Hispanics or NHW of this rural cohort than the national prevalence. Measures should be taken to reduce arsenic in drinking water in order to prevent hypothyroidism in rural areas. - Highlights: • We determined if arsenic exposure is associated with hypothyroidism in rural Texas. • Groundwater arsenic level is associated with hypothyroidism among Hispanics only. • The rate of hypothyroidism in rural Texas was higher than the US general population.

  18. Low Level Laser Therapy Reduces the Development of Lung Inflammation Induced by Formaldehyde Exposure.

    Directory of Open Access Journals (Sweden)

    Cristiane Miranda da Silva

    Full Text Available Lung diseases constitute an important public health problem and its growing level of concern has led to efforts for the development of new therapies, particularly for the control of lung inflammation. Low Level Laser Therapy (LLLT has been highlighted as a non-invasive therapy with few side effects, but its mechanisms need to be better understood and explored. Considering that pollution causes several harmful effects on human health, including lung inflammation, in this study, we have used formaldehyde (FA, an environmental and occupational pollutant, for the induction of neutrophilic lung inflammation. Our objective was to investigate the local and systemic effects of LLLT after FA exposure. Male Wistar rats were exposed to FA (1% or vehicle (distillated water during 3 consecutive days and treated or not with LLLT (1 and 5 hours after each FA exposure. Non-manipulated rats were used as control. 24 h after the last FA exposure, we analyzed the local and systemic effects of LLLT. The treatment with LLLT reduced the development of neutrophilic lung inflammation induced by FA, as observed by the reduced number of leukocytes, mast cells degranulated, and a decreased myeloperoxidase activity in the lung. Moreover, LLLT also reduced the microvascular lung permeability in the parenchyma and the intrapulmonary bronchi. Alterations on the profile of inflammatory cytokines were evidenced by the reduced levels of IL-6 and TNF-α and the elevated levels of IL-10 in the lung. Together, our results showed that LLLT abolishes FA-induced neutrophilic lung inflammation by a reduction of the inflammatory cytokines and mast cell degranulation. This study may provide important information about the mechanisms of LLLT in lung inflammation induced by a pollutant.

  19. Development of a multimedia radionuclide exposure model for low-level waste management

    International Nuclear Information System (INIS)

    Onishi, Y.; Whelan, G.; Skaggs, R.L.

    1982-03-01

    A method is being developed for assessing exposures of the air, water, and plants to low-level waste (LLW) as a part of an overall development effort of a LLW site evaluation methodology. The assessment methodology will predict LLW exposure levels in the environment by simulating dominant mechanisms of LLW migration and fate. The methodology consists of a series of physics-based models with proven histories of success; the models interact with each other to simulate LLW transport in the ecosystem. A scaled-down version of the methodology was developed first by combining the terrestrial ecological model, BIOTRAN; the overland transport model, ARM; the instream hydrodynamic model, DKWAV; and the instream sediment-contaminant transport model, TODAM (a one-dimensional version of SERATRA). The methodology was used to simulate the migration of 239 Pu from a shallow-land disposal site (known as Area C) located near the head of South Mortandad Canyon on the LANL site in New Mexico. The scenario assumed that 239 Pu would be deposited on the land surface through the natural processes of plant growth, LLW uptake, dryfall, and litter decomposition. Runoff events would then transport 239 Pu to and in the canyon. The model provided sets of simulated LLW levels in soil, water and terrestrial plants in the region surrounding the site under a specified land-use and a waste management option. Over a 100-yr simulation period, only an extremely small quantity (6 x 10 -9 times the original concentration) of buried 239 Pu was taken up by plants and deposited on the land surface. Only a small fraction (approximately 1%) of that contamination was further removed by soil erosion from the site and carried to the canyon, where it remained. Hence, the study reveals that the environment around Area C has integrity high enough to curtail LLW migration under recreational land use

  20. 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

  1. UDS and SCE in lymphocytes of persons occupationally exposed to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Tuschl, H.; Kovac, R.; Altmann, H.

    1983-03-01

    Unscheduled DNA synthesis induced by 'in vitro' UV-irradiation was investigated in lymphocytes of persons occupationally exposed to low doses of ionizing radiation (maximum registered radiation dose: 98 mrad/month). For radiation exposures >14 mrad/month, above background level, increased rates of UDS after in vitro UV-irradiation of lymphocytes were found. The bromodeoxyuridine differential chromatid labeling technique was applied to the examination of spontaneous and mytomycin C induced sister chromatid exchanges in the same population. No statistically significant difference could be determined in spontaneously occurring SCEs, while MMC induced SCEs were significantly reduced in persons exposed to radiation doses >14 mrad/month, thus indicating increased repair capability for DNA lesions inflicted by a second insult after protracted low dose irradiation. (Author) [de

  2. Misuse of statistics in the interpretation of data on low-level radiation

    International Nuclear Information System (INIS)

    Hamilton, L.D.

    1982-01-01

    Four misuses of statistics in the interpretation of data of low-level radiation are reviewed: (1) post-hoc analysis and aggregation of data leading to faulty conclusions in the reanalysis of genetic effects of the atomic bomb, and premature conclusions on the Portsmouth Naval Shipyard data; (2) inappropriate adjustment for age and ignoring differences between urban and rural areas leading to potentially spurious increase in incidence of cancer at Rocky Flats; (3) hazard of summary statistics based on ill-conditioned individual rates leading to spurious association between childhood leukemia and fallout in Utah; and (4) the danger of prematurely published preliminary work with inadequate consideration of epidemiological problems - censored data - leading to inappropriate conclusions, needless alarm at the Portsmouth Naval Shipyard, and diversion of scarce research funds

  3. Misuse of statistics in the interpretation of data on low-level radiation

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, L.D.

    1982-01-01

    Four misuses of statistics in the interpretation of data of low-level radiation are reviewed: (1) post-hoc analysis and aggregation of data leading to faulty conclusions in the reanalysis of genetic effects of the atomic bomb, and premature conclusions on the Portsmouth Naval Shipyard data; (2) inappropriate adjustment for age and ignoring differences between urban and rural areas leading to potentially spurious increase in incidence of cancer at Rocky Flats; (3) hazard of summary statistics based on ill-conditioned individual rates leading to spurious association between childhood leukemia and fallout in Utah; and (4) the danger of prematurely published preliminary work with inadequate consideration of epidemiological problems - censored data - leading to inappropriate conclusions, needless alarm at the Portsmouth Naval Shipyard, and diversion of scarce research funds.

  4. Monitoring of radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service.

  5. Monitoring of radiation exposure

    International Nuclear Information System (INIS)

    2000-02-01

    The guide specifies the requirements for the monitoring of radiation exposure in instances where radiation is used. In addition to workers, the guide covers students, apprentices and visitors. The guide shall also apply to exposure from natural radiation. However, the monitoring of radiation exposure in nuclear power plants is dealt with in YVL Guide 7.10 and 7.11. The guide defines the concepts relevant to the monitoring of radiation exposure and provides guidelines for determining the necessity of monitoring and subsequently arranging such in different operations. In addition, the guide specifies the criteria for the approval and regulatory control of the dosimetric service

  6. Radiation hormesis. Stimulatory effects of low level ionizing radiation on plant

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, Shigenobu; Masui, Hisashi; Yoshida, Shigeo; Murata, Isao [Osaka Univ., Suita (Japan). Faculty of Engineering

    1999-04-01

    Recently, the study for radiation hormesis has been executed against animals and plants; subharmful doses of radiation may evoke a stimulatory response in any organism. We executed irradiating experiments of dry seeds with fusion (D-T) neutron, fission neutron, cobalt-60 gamma-ray and investigated existence of the radiation hormesis effects by measuring germination, the length of a stalk and the total weight of a seed leaf on the 7th day after starting cultivation. And we estimated radiation hormesis effects by relative effectiveness, the ratio of the mean value of measurement subjects for the irradiated group to that of non-irradiated group. In relation to Raphanus sativus, the hormesis effects on seed leaf growth from irradiated seeds have only turned up in seed groups irradiated by the fusion (D-T) neutron. We have confirmed that absorbed dose range which revealed the effects is from 1 cGy to 10 Gy and the increasing rate is from 5 percent to 25 percent against a control group. (author)

  7. Radiation camera exposure control

    International Nuclear Information System (INIS)

    Martone, R.J.; Yarsawich, M.; Wolczek, W.

    1976-01-01

    A system and method for governing the exposure of an image generated by a radiation camera to an image sensing camera is disclosed. The exposure is terminated in response to the accumulation of a predetermined quantity of radiation, defining a radiation density, occurring in a predetermined area. An index is produced which represents the value of that quantity of radiation whose accumulation causes the exposure termination. The value of the predetermined radiation quantity represented by the index is sensed so that the radiation camera image intensity can be calibrated to compensate for changes in exposure amounts due to desired variations in radiation density of the exposure, to maintain the detectability of the image by the image sensing camera notwithstanding such variations. Provision is also made for calibrating the image intensity in accordance with the sensitivity of the image sensing camera, and for locating the index for maintaining its detectability and causing the proper centering of the radiation camera image

  8. Dose-to-risk conversion factors for low-level tritium exposures

    International Nuclear Information System (INIS)

    Straume, T.

    1992-01-01

    During the past decade, a large number of radiobiological studies have become available for tritium-many of them focusing on the relative biological effectiveness (RBE) of tritium beta rays. These and previous studies indicate that tritium in body water produces the same spectrum of radiogenic effects, e.g., cancer, genetic effects, developmental abnormalities, and reproductive effects, observed following whole-body exposure to penetrating radiations such as gamma rays and x rays. The only significant difference in biological response between tritium beta-rays and the other common low linear-energy transfer (LET) radiations, such as gamma rays and x rays, appears to be the greater biological effectiveness of tritium beta rays. For example, tritium in the oxide form (HTO) is about 2 to 3 times more effective at low doses or low dose rates than gamma rays from 137 Cs or 60 CO (Straume, 1991). When tritium is bound to organic molecules, RBE values may be somewhat larger than those for HTO. It is now clear from the wealth of tritium data available that RBEs for tritium beta rays are higher than the quality factor of unity generally used in radiation protection

  9. Radiation exposure records management

    International Nuclear Information System (INIS)

    Boiter, H.P.

    1975-12-01

    Management of individual radiation exposure records begins at employment with the accumulation of data pertinent to the individual and any previous occupational radiation exposure. Appropriate radiation monitorinng badges or devices are issued and accountability established. A computer master file is initiated to include the individual's name, payroll number, social security number, birth date, assigned department, and location. From this base, a radiation exposure history is accumulated to include external ionizing radiation exposure to skin and whole body, contributing neutron exposure, contributing tritium exposure, and extremity exposure. It is used also to schedule bioassay sampling and in-vivo counts and to provide other pertinent information. The file is used as a basis for providing periodic reports to management and monthly exposure summaries to departmental line supervision to assist in planning work so that individual annual exposures are kept as low as practical. Radiation exposure records management also includes documentation of radiation surveys performed by the health physicist to establish working rates and the individual estimating and recording his estimated exposure on a day-to-day basis. Exposure information is also available to contribute to Energy Research and Development Administration statistics and to the National Transuranium Registry

  10. Testing of environmental radiation monitors using the Risø low-level radiation measurement stations

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.

    2000-01-01

    June, 1999. The chief aims of such experiments are to allow the participants to check their home calibrations of their detectors and to compare the responses of the individual environmental radiation measurement systems used in the different EU member states and making a link between the different...... a simulation of a radioactive plume passing over the monitors during a certain time was made using a specially designed source set up in the field that was able to vary the air kerma rate from low activity Cs-137 sources additional to the natural air kerma rate. It is demonstrated that a typical environmental...

  11. Cancer risks related to low-level RF/MW exposures, including cell phones.

    Science.gov (United States)

    Szmigielski, Stanislaw

    2013-09-01

    For years, radiofrequency (RF) and microwave (MW) radiations have been applied in the modern world. The rapidly increasing use of cellular phones called recent attention to the possible health risks of RF/MW exposures. In 2011, a group of international experts organized by IARC (International Agency for Research on Cancer in Lyon) concluded that RF/MW radiations should be listed as a possible carcinogen (group 2B) for humans. Three meta-analyses of case-control studies have concluded that using cell phones for more than ten years was associated with an increase in the overall risk of developing a brain tumor. The Interphone Study, the largest health-related case-control international study of use of cell phones and head and neck tumors, showed no statistically significant increases in brain cancers related to higher amounts of cell phone use, but excess risk in a small subgroup of more heavily exposed users associated with latency and laterality was reported. So far, the published studies do not show that mobile phones could for sure increase the risk of cancer. This conclusion is based on the lack of a solid biological mechanism, and the fact that brain cancer rates are not going up significantly. However, all of the studies so far have weaknesses, which make it impossible to entirely rule out a risk. Mobile phones are still a new technology and there is little evidence about effects of long-term use. For this reason, bioelectromagnetic experts advise application of a precautionary resources. It suggests that if people want to use a cell phone, they can choose to minimize their exposure by keeping calls short and preferably using hand-held sets. It also advises discouraging children from making non essential calls as well as also keeping their calls short.

  12. Radiation exposure management

    International Nuclear Information System (INIS)

    Snihs, J.O.

    1985-01-01

    Radiation exposure management includes administrative control, education and training, monitoring and dose assessments and planning of work and radiation protection. The information and discussion given in the paper are based on experiences in Sweden mainly from nuclear power installations. (Author)

  13. Natural radiation exposure indoors

    International Nuclear Information System (INIS)

    Brown, L.; Cliff, K.D.; Wrixon, A.D.

    1981-01-01

    A brief review is presented of the state of knowledge of indoor natural radiation exposure in the U.K. and the current survey work the N.R.P.B. is carrying out in this field. Discussion is limited in this instance to the improvement in estimation of population exposure and the identification of areas and circumstances in which high exposure occur, rather than the study of properties of a building and methods of building affecting exposure to radiation. (U.K.)

  14. Monitoring and control of occupational radiation exposure in Switzerland

    International Nuclear Information System (INIS)

    Moser, M.

    1997-01-01

    Occupational exposure is the most prominent example for the prolonged exposure to low level ionizing radiation characterized by low doses and dose rates. In this paper the occupational exposure in Switzerland is presented and the regulatory control of this exposure in the framework of the new radiation protection regulations is discussed. (author)

  15. Neoplasms in dogs receiving low-level gamma radiation during pre- and postnatal development

    International Nuclear Information System (INIS)

    Thomassen, R.W.; Angleton, G.M.; Lee, A.C.; Phemister, R.D.; Benjamin, S.A.

    1978-01-01

    Beagle dogs were given whole-body exposure to 60 Co gamma radiation at one of six ages of pre- or postnatal life. Four-hundred and eighty dogs, 120 for each age at exposure, received 20 R at 8, 28 or 55 days postcoitus (dpc) or at 2 days postpartum (dpp). Similarity 480 dogs, in groups of 120, were exposed to 100 R at these same ages. Exposures of 100 R were also given to 118 dogs at 70 dpp and 231 dogs at 365 dpp. An additional 359 dogs were sham-irradiated. Mean values for each age at exposure ranged from 15.6 to 17.5 rads for 20 R exposures and from 80.8 to 88.3 rads for exposure to 100 R. Mortality due to neoplasia during the initial ten years of the experiment was examined. Twenty dogs died or were killed because of neoplasia, 19 having been irradiated. Tumours in these 19 irradiated dogs included five malignant lymphomas, eight carcinomas (two of mammary origin, two of prostatic origin, and one each of oral mucosa, ovary, urinary bladder, and thyroid origin), four sarcomas (two haemangiosarcomas, one fibrosarcoma and one mast cell sarcoma), one astrocytoma, and one hepatocellular adenoma. Neoplasms occurred in all irradiated groups except 8 dpc (20 and 100 R) and 70 dpp (100 R). Eleven neoplasms developed in dogs irradiated perinatally (55 dpc or 2 dpp) with 20 or 100 R. Four of the tumours in the perinatally irradiated dogs were detected before two years of age. The earliest death was at three months, due to an astrocytoma. Preliminary analyses point to findings of particular interest: (1) the preponderance of neoplasms causing death or euthanasia occurred in irradiated dogs; (2) the unusual finding of four deaths due to neoplasia before two years of age in perinatally irradiated dogs; and (3) the occurrence of five malignant lymphomas in this relatively small irradiated population

  16. Proof of causation through expert opinion evidence in low-level radiation cases

    International Nuclear Information System (INIS)

    Heideck, R.E.

    1985-01-01

    Tort law requires that the injured person prove that the injury was caused by a particular exposure to radiation for which the defendant is responsible. Heideck shows how expert evidence helps the court or jury resolve this question. The author analyzes a recent effort to bridge the gap between the legal requirement of proof of causation in individual cases and the conclusions that derive from group statistics. Some scientists argue that this approach is more technically sound than traditional tort law because it attempts to develop a probability of causation in individual cases

  17. Cytogenetic monitoring, radiosensitivity study and adaptive response of workers exposed to low level ionizing radiation

    International Nuclear Information System (INIS)

    Peitl Junior, Paulo

    1996-01-01

    The objectives of the present study were: To determine the frequencies of chromosome aberrations in lymphocytes from individuals belonging to professionally exposed groups, under normal conditions; to determine the possible differences in radiosensitivity between the lymphocytes of technicians and controls after in vitro irradiation with gamma rays during the G 1 phase of the cell cycle (radiosensitivity study), and to examine the influence of in vivo and in vitro pre-exposure to low doses of radiation on the frequency of chromosome aberrations induced in vitro by high doses (study of the adaptive response) in a group of technicians (T) compared to controls (C). (author)

  18. Exposure to natural radiation

    International Nuclear Information System (INIS)

    Green, B.M.R.

    1985-01-01

    A brief report is given of a seminar on the exposure to enhanced natural radiation and its regulatory implications held in 1985 at Maastricht, the Netherlands. The themes of the working sessions included sources of enhanced natural radiation, parameters influencing human exposure, measurement and survey programmes, technical countermeasures, risk and assessment studies, philosophies of dose limitations and national and international policies. (U.K.)

  19. Radiation exposure and radiation protection

    International Nuclear Information System (INIS)

    Heuck, F.; Scherer, E.

    1985-01-01

    The present volume is devoted to the radiation hazards and the protective measures which can be taken. It describes the current state of knowledge on the changes which exposure to ionizing rays and other forms of physical energy can induce in organs and tissues, in the functional units and systems of the organism. Special attention is paid to general cellular radiation biology and radiation pathology and to general questions of the biological effects of densely ionizing particle radiation, in order to achieve a better all-round understanding of the effects of radiation on the living organism. Aside from the overviews dealing with the effects of radiation on the abdominal organs, urinary tract, lungs, cerebral and nervous tissue, bones, and skin, the discussion continues with the lymphatic system, the bone marrow as a bloodforming organ, and the various phases of reaction in the reproductive organs, including damage and subsequent regeneration. A special section deals with environmental radiation hazards, including exposure to natural radiation and the dangers of working with radioactive substances, and examines radiation catastrophes from the medical point of view. Not only reactor accidents are covered, but also nuclear explosions, with exhaustive discussion of possible damage and treatment. The state of knowledge on chemical protection against radiation is reviewed in detail. Finally, there is thorough treatment of the mechanism of the substances used for protection against radiation damage in man and of experience concerning this subject to date. In the final section of the book the problems of combined radiotherapy are discussed. The improvement in the efficacy of tumor radiotherapy by means of heavy particles is elucidated, and the significance of the efficacy of tumor therapy using electron-affinitive substances is explained. There is also discussion of the simultaneous use of radiation and pharmaceuticals in the treatment of tumors. (orig./MG) [de

  20. Americans' Average Radiation Exposure

    International Nuclear Information System (INIS)

    2000-01-01

    We live with radiation every day. We receive radiation exposures from cosmic rays, from outer space, from radon gas, and from other naturally radioactive elements in the earth. This is called natural background radiation. It includes the radiation we get from plants, animals, and from our own bodies. We also are exposed to man-made sources of radiation, including medical and dental treatments, television sets and emission from coal-fired power plants. Generally, radiation exposures from man-made sources are only a fraction of those received from natural sources. One exception is high exposures used by doctors to treat cancer patients. Each year in the United States, the average dose to people from natural and man-made radiation sources is about 360 millirem. A millirem is an extremely tiny amount of energy absorbed by tissues in the body

  1. Epidemiological studies of general population groups exposed to low-level radiation

    International Nuclear Information System (INIS)

    Davies, J.M.; Inskip, H.

    1986-01-01

    The exposure of man to radiation and the resulting risk of carcinogenesis continue to be of concern to the public. In this context, there is often a tendency to carry out epidemiological studies concerning the induction of cancer in radiation workers and members of the public which are not supported by a statistically valid data base or whose result are misinterpreted or misused. To assist national authorities in evaluating radiological risks, the Nuclear Energy Agency has sponsored a critical review of the methodologies for, and the limitations of, these epidemiological studies, and of the precautions to be adopted in interpreting their results. Prepared by two consultants, Dr. Joan M. Davies and Dr. Hazel Inskip, the review focuses on the problems encountered when carrying out epidemiological studies on groups of the general population exposed to radiation, and using their results for radiological protection purposes. The primary objective is to provide background material for national authorities who have responsibilities in the field of radiological protection, as well as to other persons interested in this subject. It is published under the responsibility of the Secretary General of the OECD, and does not necessarily reflect the views of Member Governments

  2. Immunohistopathology in the Guinea Pig Following Chronic Low-Level Exposure to Chemical Warfare Agents

    Science.gov (United States)

    2005-11-01

    U.S. Army Medical Research Institute of Chemical Defense USAMRICD-TR-05-09 Immunohistopathology in the Guinea Pig Following Chronic Low...2005 2. REPORT TYPE Technical Report 3. DATES COVERED (From - To) May 2003 to April 2005 4. TITLE AND SUBTITLE Immunohistopathology in the Guinea Pig Following...release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Guinea pigs exposed repeatedly to low levels of chemical warfare nerve agents

  3. Exposure to low levels of hydrogen sulfide : symptoms, sensory function, and cognitive performance

    International Nuclear Information System (INIS)

    Fiedler, N.; Kipen, H.; Lioy, P.; Zhang, J.; Weisel, C.

    2003-01-01

    Petroleum refineries, kraft paper mills, and coke ovens are some of the sources of hydrogen sulfide exposure. In 1987, the World Health Organization (WHO) recommended an ambient exposure standard of .003 ppm for odor and .01 ppm for eye irritation. In communities with high exposure levels, health effects have been documented as being headaches, eye and nasal symptoms, coughs, breathlessness and decreased psychomotor performance. Refinery workers in some jurisdictions around the world have been subjected to higher exposure levels. This report presents results of clinical studies on the neurobehavioral effects in rats. The tasks of memory and learning in rats parallels those in humans. A pilot exposure study examined the health effects of controlled exposures to 3 concentrations of hydrogen sulfide (.05, .50, and 5 ppm). It was concluded that changes in neurobehavioral measurements can be directly associated with exposure and dose-response. 25 figs

  4. Radiation exposure during ESWL

    International Nuclear Information System (INIS)

    McCullough, D.L.; Van Swearingen, F.L.; Dyer, R.B.; Appel, B.

    1987-01-01

    This paper discusses exposure to ionizing radiation by the ESWL patient and for health professionals. Although the patient is exposed acutely to the highest level of radiation, the lithotripter team is chronically exposed to ionizing radiation at varying levels. Attention to detail is important in reducing that exposure. The operator should follow the guidelines set forth in this chapter in order to minimize exposure to the patient, himself or herself, and to all co-workers. At the present time, investigation of an alternative modality for stone localization, ultrasound, is being investigated

  5. Perspectives on repeated low-level blast and the measurement of neurotrauma in humans as an occupational exposure risk

    Science.gov (United States)

    Carr, W.; Dell, K. C.; Yanagi, M. A.; Hassan, D. M.; LoPresti, M. L.

    2017-11-01

    A pressing question in military medical research is the nature and degree of effects on the human brain from occupational repeated exposure to low-level explosive blast, but reliable and effective means to objectively measure such effects remain elusive. In survey results, headache, difficulty sleeping, irritability, cognitive impairment, and a variety of other symptoms consistent with post-concussive syndrome have been reported by those exposed to blast and there was positive correlation between degree of blast exposure and degree of symptomology, but an important goal is to obtain more objective evidence of an effect than self-report alone. This review reflects recent efforts to measure and evaluate such hypothesized effects and current recommendations for ongoing study. Optimal measures are likely those with sensitivity and specificity to systemic effects in mild neurotrauma, that have minimal to no volitional component, and that can be sampled relatively quickly with minimal intrusion in prospective, observational field studies during routine training with explosives. An understanding of an association between parameters of exposure to repeated low-level blast and negative neurologic effects would support the evaluation of clinical implications and development of protective equipment and surveillance protocols where warranted. At present, low-level blast exposure surveillance measurements do not exist as a systematic record for any professional community.

  6. Acute myeloid and chronic lymphoid leukaemias and exposure to low-level benzene among petroleum workers

    Science.gov (United States)

    Rushton, L; Schnatter, A R; Tang, G; Glass, D C

    2014-01-01

    Background: High benzene exposure causes acute myeloid leukaemia (AML). Three petroleum case–control studies identified 60 cases (241 matched controls) for AML and 80 cases (345 matched controls) for chronic lymphoid leukaemia (CLL). Methods: Cases were classified and scored regarding uncertainty by two haematologists using available diagnostic information. Blinded quantitative benzene exposure assessment used work histories and exposure measurements adjusted for era-specific circumstances. Statistical analyses included conditional logistic regression and penalised smoothing splines. Results: Benzene exposures were much lower than previous studies. Categorical analyses showed increased ORs for AML with several exposure metrics, although patterns were unclear; neither continuous exposure metrics nor spline analyses gave increased risks. ORs were highest in terminal workers, particularly for Tanker Drivers. No relationship was found between benzene exposure and risk of CLL, although the Australian study showed increased risks in refinery workers. Conclusion: Overall, this study does not persuasively demonstrate a risk between benzene and AML. A previously reported strong relationship between myelodysplastic syndrome (MDS) (potentially previously reported as AML) at our study's low benzene levels suggests that MDS may be the more relevant health risk for lower exposure. Higher CLL risks in refinery workers may be due to more diverse exposures than benzene alone. PMID:24357793

  7. ASSESSING EXPOSURE TO THE PUBLIC FROM LOW LEVEL RADIOACTIVE WASTE (LLW) TRANSPORTATION TO THE NEVADA TEST SITE

    International Nuclear Information System (INIS)

    Miller, J.J.; Campbell, S.; Church, B.W.; Shafer, D. S.; Gillespie, D.; Sedano, S.; Cebe, J.J.

    2003-01-01

    The United States (U.S.) Department of Energy (DOE) Nevada Test Site (NTS) is one of two regional sites where low-level radioactive waste (LLW) from approved DOE and U.S. DOD generators across the United States is disposed. In federal fiscal year (FY) 2002, over 57,000 cubic meters of waste was transported to and disposed at the NTS. DOE and U.S. Department of Transportation (DOT) regulations ensure that radiation exposure from truck shipments to members of the public is negligible. Nevertheless, particularly in rural communities along transportation routes in Utah and Nevada, there is perceived risk from members of the public about incremental exposure from LLW trucks, especially when ''Main Street'' and the LLW transportation route are the same. To better quantify the exposure to gamma radiation, a stationary monitoring array of four pressurized ion chambers (PICs) have been set up in a pullout just before LLW trucks reach the entrance to the NTS. The PICs are positioned at a distance of one meter from the sides of the truck trailer and at a height appropriate for the design of the trucks that will be used in FY2003 to haul LLW to the NTS. The use of four PICs (two on each side of the truck) is to minimize and to correct for non-uniformity where radiation levels from waste packages vary from side to side, and from front to back in the truck trailer. The PIC array is being calibrated by collecting readings from each PIC exposed to a known 137Cs source that was positioned at different locations on a flatbed stationed in the PIC array, along with taking secondary readings from other known sources. Continuous data collection using the PICs, with and without a truck in the array, is being used to develop background readings. In addition, acoustic sensors are positioned on each side of the PIC array to record when a large object (presumably a truck) enters the array. In FY2003, PIC surveys from as many incoming LLW trucks as possible will be made and survey data

  8. Low-level maternal methylmercury exposure through rice ingestion and potential implications for offspring health

    Energy Technology Data Exchange (ETDEWEB)

    Rothenberg, Sarah E., E-mail: rothenberg.sarah@gmail.com [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Feng Xinbin, E-mail: fengxinbin@vip.skleg.cn [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China); Li Ping [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, 46 Guanshui Lu, Guiyang 550002 (China)

    2011-04-15

    Fish consumption is considered the primary pathway for MeHg (MeHg) exposure; however, MeHg exposure also occurs through rice ingestion. Rice is grown in an aquatic environment and although documented MeHg concentrations in rice are lower compared to fish tissue, human exposures exceed international guidelines in some regions where rice is a staple food and rice MeHg levels are elevated. Studies concerning human health exposure to MeHg should also include populations where maternal MeHg exposure occurs through ingestion of rice. Rice does not contain long-chain polyunsaturated fatty acids, which are associated with confounding developmental outcomes in offspring. Rice is also a staple food for more than half the world's population; therefore, it is critical to investigate the potential health risks of maternal ingestion of rice to the developing fetus, the most susceptible population to the deleterious effects of MeHg. Data concerning MeHg in rice are reviewed and micronutrients in rice are discussed. - Research highlights: > Maternal methylmercury exposure through rice may be important. > Rice does not contain the same micronutrients as fish, but may contain methylmercury. > Effects to offspring from methylmercury without beneficial micronutrients are unknown. - Studies concerning maternal methylmercury exposure and cognitive outcomes for offspring should include populations where rice ingestion is the primary methylmercury exposure pathway.

  9. Low-level maternal methylmercury exposure through rice ingestion and potential implications for offspring health

    International Nuclear Information System (INIS)

    Rothenberg, Sarah E.; Feng Xinbin; Li Ping

    2011-01-01

    Fish consumption is considered the primary pathway for MeHg (MeHg) exposure; however, MeHg exposure also occurs through rice ingestion. Rice is grown in an aquatic environment and although documented MeHg concentrations in rice are lower compared to fish tissue, human exposures exceed international guidelines in some regions where rice is a staple food and rice MeHg levels are elevated. Studies concerning human health exposure to MeHg should also include populations where maternal MeHg exposure occurs through ingestion of rice. Rice does not contain long-chain polyunsaturated fatty acids, which are associated with confounding developmental outcomes in offspring. Rice is also a staple food for more than half the world's population; therefore, it is critical to investigate the potential health risks of maternal ingestion of rice to the developing fetus, the most susceptible population to the deleterious effects of MeHg. Data concerning MeHg in rice are reviewed and micronutrients in rice are discussed. - Research highlights: → Maternal methylmercury exposure through rice may be important. → Rice does not contain the same micronutrients as fish, but may contain methylmercury. → Effects to offspring from methylmercury without beneficial micronutrients are unknown. - Studies concerning maternal methylmercury exposure and cognitive outcomes for offspring should include populations where rice ingestion is the primary methylmercury exposure pathway.

  10. Biological effects and hazards of radiation exposure

    International Nuclear Information System (INIS)

    Boas, J.F.; Solomon, S.B.

    1990-01-01

    Radiation induced carcinogenesis and mutagenesis form the main risk to health from exposure to low levels of radiation. This risk effects can be at least qualitatively understood by considering the effects of radiation on cell DNA. Whilst exposure to high levels of radiation results in a number of identifiable effects, exposure to low levels of radiation may result in effects which only manifest themselves after many years. Risk estimates for low levels of radiation have been derived on the basis of a number of assumptions. In the case of uranium mine workers a major hazard arises from the inhalation of radon daughters. Whilst the correlation between radon daughter exposure and lung cancer incidence is well established, the numerical value of the risk factor is the subject of controversy. ICRP 50 gives a value of 10 cases per 10 6 person-years at risk per WLM (range 5-15 x 10 -6 PYR -1 WLM -1 ). The effect of smoking on lung cancer incidence rates amongst miners is also controversial. Nevertheless, smoking by miners should be discouraged

  11. Biostimulation effects on wheat seeds (Triticum Aestivum L) caused by low level red laser radiation with λ = 660 nm

    International Nuclear Information System (INIS)

    Hernandez, M.; Michtchenko, A.

    2009-01-01

    The principal objective is to study the biostimulation effects caused by a semiconductor low level laser radiation with ? = 660 nm on wheat seeds (Triticum Aestivum L). Seeds were treated before sowing with this laser light source. An increase in the growth of the stem of 12% with respect to control seeds was registered for seeds radiated by an intensity of 15mW/cm 2 and an irradiation time of 60 seconds. (Author)

  12. Plant response to chronic exposure of low levels of oxidant type air pollution

    Energy Technology Data Exchange (ETDEWEB)

    Feder, W.A.

    1970-01-01

    Cultivars of geranium and carnation exhibit a reduction of side branching, a retardation of floral initiation, and a decrease in floral productivity when exposed daily for 5-7 hr to 0.1 ppm ozone for 1-3 months. These plants also exhibit a reduction in leaf size, an increase in internode length, a progressive destruction of leaf tissue and eventual defoliation in the case of geranium. Cultivars of petunia exposed to chronic low levels of oxidant are slower to flower and bear fewer flowers than those same cultivars grown in charcoal-filtered air from the same source. These plant effects are of special interest because they occur in the presence of pollutant levels encountered daily in areas surrounding US metropolitan centres. 6 references, 3 figures.

  13. Plant response to chronic exposure to low levels of oxidant-type pollution

    Energy Technology Data Exchange (ETDEWEB)

    Feder, W.A.

    1970-01-01

    Cultivars of geranium and carnation exhibit a reduction of side branching, a retardation of floral initiation, and a decrease in floral productivity when exposed daily for 5-7 h to 0.1 ppm ozone for 1-3 months. These plants also exhibit a reduction in leaf size, an increase in internode length, a progressive destruction of leaf tissue and eventual defoliation in the case of geranium. Cultivars of petunia exposed to chronic low levels of oxidant are slower to flower and bear fewer flowers than those same cultivars grown in charcoal-filtered air from the same source. These plant effects are of special interest because they occur in the presence of pollutant levels encountered daily in areas surrounding US metropolitan centers.

  14. Low-Level Effects of VX Vapor Exposure on Pupil Diameter and Cholinesterase Levels in Rats

    National Research Council Canada - National Science Library

    Benton, B. J; Crosier, R. B; Sommerville, D. R; Jakubowski, E. M., Jr; Anthony, J. S., Jr; Scotto, J; Hulet, S. W; Whalley, C. E; Crouse, C. L; Matson, K. L; Miller, D. B

    2004-01-01

    .... Results show that the median effective dosages (ECt sub 50) for miosis are approximately an order of magnitude lower than the calculated ECt sub 50 values for both GB and GF at each of the 3 exposure durations...

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

    International Nuclear Information System (INIS)

    Schultz, E.

    1985-01-01

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

  16. Basal body and striated rootlet changes in primate macular retinal pigmented epithelium after low level diffuse argon laser radiation. Final report 1981-1982

    Energy Technology Data Exchange (ETDEWEB)

    Schuschereba, S.T.; Zwick, H.; Stuck, B.E.; Beatrice, E.S.

    1982-09-01

    Basal bodies or centrioles (BB - microtubule organizing centers) and striated rootlets (SR - bundles of 60 A action-like filaments) have a close association in primate retinal pigmented epithelial (RPE) cells. The frequency of occurrence of these structures was evaluated in the macular RPE after repeated exposure to low level diffuse argon laser radiation (DALR). The awake chaired animal's head was restrained and positioned near the center of the 0.75 m hemisphere which was diffusely irradiated with 514.5 nm laser radiation. The right eye of each subject was occluded during the two-hour exposure session. The first subject received 24 cumulative hours of exposure, the second, 40 hours and the third, 42 hours.

  17. No effect of low-level chronic neonicotinoid exposure on bumblebee learning and fecundity

    Directory of Open Access Journals (Sweden)

    Saija Piiroinen

    2016-03-01

    Full Text Available In recent years, many pollinators have declined in abundance and diversity worldwide, presenting a potential threat to agricultural productivity, biodiversity and the functioning of natural ecosystems. One of the most debated factors proposed to be contributing to pollinator declines is exposure to pesticides, particularly neonicotinoids, a widely used class of systemic insecticide. Also, newly emerging parasites and diseases, thought to be spread via contact with managed honeybees, may pose threats to other pollinators such as bumblebees. Compared to honeybees, bumblebees could be particularly vulnerable to the effects of stressors due to their smaller and more short-lived colonies. Here, we studied the effect of field-realistic, chronic clothianidin exposure and inoculation with the parasite Nosema ceranae on survival, fecundity, sugar water collection and learning using queenless Bombus terrestris audax microcolonies in the laboratory. Chronic exposure to 1 ppb clothianidin had no significant effects on the traits studied. Interestingly, pesticide exposure in combination with additional stress caused by harnessing bees for Proboscis Extension Response (PER learning assays, led to an increase in mortality. In contrast to previous findings, the bees did not become infected by N. ceranae after experimental inoculation with the parasite spores, suggesting variability in host resistance or parasite virulence. However, this treatment induced a slight, short-term reduction in sugar water collection, potentially through stimulation of the immune system of the bees. Our results suggest that chronic exposure to 1 ppb clothianidin does not have adverse effects on bumblebee fecundity or learning ability.

  18. Radiation exposure during ureteroscopy

    International Nuclear Information System (INIS)

    Bagley, D.H.; Cubler-Goodman, A.

    1990-01-01

    Use of fluoroscopy during ureteroscopy increases the risk of radiation exposure to the urologist and patient. Radiation entrance dosages were measured at skin level in 37 patients, and at the neck, trunk and finger of the urologist, and neck and trunk of the circulating nurse. Radiation exposure time was measured in 79 patients, and was related to the purpose of the procedure and the type of ureteroscope used, whether rigid or flexible. Exposure could be minimized by decreasing the fluoroscopy time. A portable C-arm fluoroscopy unit with electronic imaging and last image hold mode should be used to minimize exposure time. Lead aprons and thyroid shields should be used by the urologist and other personnel in the endoscopy room

  19. Practical Model of Cement Based Grout Mix Design, for Use into Low Level Radiation Waste Management

    Directory of Open Access Journals (Sweden)

    Radu Lidia

    2015-12-01

    Full Text Available The cement based grouts, as functional performance composite materials, are widely used for both immobilisation and encapsulation as well as for stabilization in the field of inorganic waste management. Also, to ensure that low level radioactive waste (LLW are contained for storage and ultimate disposal, they are encapsulated or immobilized in monolithic waste forms, with cement –based grouts.

  20. Basic units and concepts in radiation exposures

    International Nuclear Information System (INIS)

    Mlekodaj, R.L.

    1992-01-01

    Some of the most common units, concepts and models in use today in dealing with radiation exposures and the associated risks are presented. Discussions toward a better understanding of some of the basic difficulties in quantifying risks associated with low levels of radiation are presented. The main thrust of this talk is to lay a foundation for better understanding and appreciation of the talks to follow in this symposium

  1. Metabolic response to low-level toxicant exposure in a novel renal tubule epithelial cell system

    NARCIS (Netherlands)

    Ellis, James Keith; Athersuch, Toby James; Cavill, Rachel; Radford, Robert; Slattery, Craig; Jennings, Paul; McMorrow, Tara; Ryan, Michael P; Ebbels, Timothy Mark David; Keun, Hector Charles

    Toxicity testing is vital to protect human health from exposure to toxic chemicals in the environment. Furthermore, combining novel cellular models with molecular profiling technologies, such as metabolomics can add new insight into the molecular basis of toxicity and provide a rich source of

  2. Effects of low-level exposure to xenobiotics present in paints on oxidative stress in workers.

    Science.gov (United States)

    Moro, Angela M; Charão, Mariele; Brucker, Natália; Bulcão, Rachel; Freitas, Fernando; Guerreiro, Gilian; Baierle, Marília; Nascimento, Sabrina; Waechter, Fernanda; Hirakata, Vânia; Linden, Rafael; Thiesen, Flávia V; Garcia, Solange Cristina

    2010-09-15

    Paints are composed of an extensive variety of hazardous substances, such as organic solvents and heavy metals. Biomonitoring is an essential tool for assessing the risk to occupational health. Thus, this study analyzed the levels of biomarkers of exposure for toluene, xylene, styrene, ethylbenzene, and lead, as well as the oxidative stress biomarker alterations in painters of an industry. Lipid peroxidation biomarker (MDA), delta-aminolevulinate dehydratase (ALA-D), nonprotein thyol groups, superoxide dismutase and catalase (CAT) were analyzed in exposed and nonexposed subjects. We estimated which of the paint constituents have the greatest influence on the changes in the biomarkers of oxidative stress in this case of co-exposure. The results demonstrated that despite the fact that all the biomarkers of exposure were below the biological exposure limits, the MDA levels and antioxidant enzyme activities were increased, while nonprotein thyol groups and ALA-D levels were decreased in painters when compared with nonexposed subjects. After statistic test, toluene could be suggested as the principal factor responsible for increased lipid peroxidation and inhibition of ALA-D enzyme; however, further studies on the inhibition of ALA-D enzyme by toluene are necessary. Copyright 2010 Elsevier B.V. All rights reserved.

  3. Impact of exposure to low levels of mercury on the health of dental workers

    Directory of Open Access Journals (Sweden)

    Leda Freitas Jesus

    2016-09-01

    Full Text Available This work evaluated the impact of exposure to mercury on the health of workers comparing dentists and dental assistants exposed to mercury by handling amalgam in a public dental clinic with a reference group which, in private offices, did not make use of the metal in their professional routine. Data collection included mercury levels in urine and air samples determined by cold vapor atomic absorption spectrometry, questionnaires and direct observation. The difference between urine and air samples in both groups was statistically significant while mercury levels in air and urine showed positive associations. Mercury concentration in urine correlated with gender, practice time, and age of workers. Half of those exposed had complaints compatible with mercury contamination. Among the exposed, the most common complaints were cognitive and neurocognitive symptoms. Correlations between symptoms and exposure time and also number of amalgam fillings placed per week were positive. Amalgam handling resulted in environmental and biological contamination by mercury.

  4. Assessment of hemato-biochemical parameters on exposure to low level of deltamethrin in mouse model

    Directory of Open Access Journals (Sweden)

    Anita Tewari

    2014-03-01

    Full Text Available Aim: In this study, sub-acute toxicity of deltamethrin on hematological and biochemical blood parameters of male albino Swiss mice was evaluated. Materials and Methods: Generally, the maximum permissible residue level (MRL of deltamethrin for food products lies between 0.01 to 0.5 mg/kg body weight. So the mice were exposed orally with two doses of pesticide i.e. 0.1 and 0.5 mg/kg body weight. The doses were given on a daily basis for a period of 15 days and 30 days respectively. Ground nut oil was used as control treatment. Samples of blood were collected at the end of the treatment. Hepatotoxicity was evaluated by quantitative analysis of the serum enzymes alanine transaminase (ALT, aspartate transaminase (AST, alkaline phosphatase (ALKP, total bilirubin (TBIL and serum urea. Alterations of hematological parameters were analysed by total leukocyte, differential leukocyte count and hemoglobin levels. Results: Significant increase in the levels of hepatic enzymes (ALT, AST, ALKP were observed for both doses, but no considerable differences were found by histological analysis. The hematological parameters showed significant alterations for 0.5 mg/kg body weight dose which is indicated by leukocytosis, lymphocytosis and neutropenia in long duration study. Conclusions: The results indicated that even very low dose of deltamethrin can promote hematological and hepatic alterations. Thus it is imperative to do further studies on the detrimental effect of the low levels of pyrethroid commonly present in our food, which further necessitate the reduction of maximum permissible levels of residual synthetic pyrethroid levels in foods and feed.

  5. Benzene in blood as a biomarker of low level occupational exposure

    Energy Technology Data Exchange (ETDEWEB)

    Brugnone, F.; Perbellini, L.; Romeo, L.; Cerpelloni, M.; Bianchin, M.; Tonello, A. [Institute of Occupational Medicine, University of Verona, Policlinico Borgo Roma, 37134 Verona (Italy)

    1999-09-01

    The occupational airborne exposure to benzene of 150 workers employed in petrol stations and a refinery plant was assessed using personal sampling pumps. All workers provided blood samples after the end of work and on the following morning before resuming work. Benzene concentrations in the blood of 243 non-occupationally-exposed subjects were also measured. The median occupational benzene exposure for all 150 workers studied was 80 {mu}g/m{sup 3}. Overall median blood benzene of all workers was 251 ng/l at the end of the shift, and 174 ng/l the following morning. The benzene concentrations measured in blood collected the following morning proved to be significantly lower than those measured at the end of the shift. Median blood benzene for the 243 'normal' subjects was 128 ng/l, which was significantly lower than that measured in the workers before a new work shift. The median blood benzene concentration was significantly higher in smokers than in non-smokers, both in the general population (210 ng/l vs. 110 ng/l) and in the exposed workers at the end of the shift (476 ng/l vs. 132 ng/l) and the following morning (360 ng/l vs. 99 ng/l). End-of-shift blood benzene correlated significantly with environmental exposure; this correlation was better in the 83 non-smokers than in the 67 smokers. In non-smokers with the median benzene occupational exposure of 50 {mu}g/m{sup 3}, no difference was found in blood benzene concentration in exposed and non-exposed subjects.

  6. Temporal variability of the quality of Taraxacum officinale seed progeny from the East-Ural radioactive trace: is there an interaction between low level radiation and weather conditions?

    Science.gov (United States)

    Pozolotina, Vera N; Antonova, Elena V

    2017-03-01

    The multiple stressors, in different combinations, may impact differently upon seed quality, and low-level doses of radiation may enhance synergistic or antagonistic effects. During 1991-2014 we investigated the quality of the dandelion (Taraxacum officinale s.l.) seed progeny growing under low-level radiation exposure at the East-Ural Radioactive Trace (EURT) area (result of the Kyshtym accident, Russia), and in plants from areas exposed to background radiation. The viability of the dandelion seed progeny was assessed according to chronic radiation exposure, accounting for the variability of weather conditions among years. Environmental factors (temperature, precipitation, and their ratio in different months) can modify the radiobiological effects. We found a wide range of possible responses to multiple stressors: inhibition, stimulation, and indifferent effects in different seasons. The intraspecific variability of the quality of dandelion seed progeny was greatly increased under conditions of low doses of chronic irradiation. Temperature was the most significant factor for seed progeny formation in the EURT zone, whereas the sums of precipitation and ratios of precipitation to temperature dominantly affected organisms from the background population.

  7. Effect of low-level intensity EHF radiation on endurance and reproductivity of Drosophila Melanogaster

    International Nuclear Information System (INIS)

    Shakhbazov, V.G.; Chepel', L.M.; Bulgakov, B.M.; Sirenko, S.P.; Belous, O.I.; Fisun, A.I.

    1999-01-01

    The effect of the low-intensity microwaves on three gene-radiations of the imago Drosophila Melanogaster has been investigated out. The radiation source was tuned from 37 to 53 GHz. The thermoimmunity and reproductivity of the first generation of females and males of imago after processing by radiation. The obtained effect can be considered as physiological heterosis

  8. Acceptance criteria for deposition of low-level and intermediate-level radiation levels radioactive wastes

    International Nuclear Information System (INIS)

    2002-09-01

    This norm establishes the criteria for acceptance low and intermediate radiation level for safe deposition in repositories, for assuring the protection of workers, population and environment against the hazardous effects of the ionizing radiations. The criteria of this norm applies to the low and intermediate radiation levels

  9. Critical reevaluation of the dose-response relationships for carcinogenic effects of low-level ionizing radiation

    International Nuclear Information System (INIS)

    Upton, A.C.

    2003-01-01

    In recent decades, it has been customary, for radiation protection purposes, to assume that the overall risk of radiation-induced cancer increases as a linear-nonthreshold function of the dose. The existing data do not exclude the existence of a threshold, however, and the dose-response relationship is known to vary, depending on the type of cancer in queation, the dose, dose rate, and LET of the radiation, the age, sex, and physiological state of the exposed individuals, and other variables, including the potential influence of adaptive responses and bystander effects at low doses. In light of advncing knowledge, therefore, the dose-response relationship for carcinogenic effects of low-level radiation has been reevaluated periodically by the National Council on Radiation Protection and Measurements, the International Commission of Radiological Protection, the United Nations Scientific Committee on the Effects of Atomic Radiation, the U.S. National Academy of Sciences, and other organizations. The most recent such reviews have generally found the weight of evidence to suggest that lesions which are precursors to cancer (i.e., mutations and chromosome aberrations), and certain types of cancer as well, may increase in frequency linearly with the dose in the low-dose domain. On this basis, it is concluded that no alternative dose-response model for the carcinogenic effects of low-level radiation is more plausible than the linear-nonthreshold model, although other dose-response relationships cannot be excluded. (authors)

  10. Silica exposure to excavation workers during the excavation of a low level radiological waste pit and tritium disposal shafts

    International Nuclear Information System (INIS)

    Wilson, K.M.

    1995-01-01

    This study evaluated the task-length average (TLA) respirable dust and respirable silica airborne concentrations to which construction workers excavating volcanic tuff at Los Alamos National Laboratory (LANL) were exposed. These workers were excavating a low level radiological waste disposal pit of final dimensions 720 feet long, 132 feet wide and 60 feet deep. The objectives of this study were as follows: (1) evaluate exposures; (2) determine if the type of machinery used affects the respirable dust concentration in the breathing zone of the worker; (3) evaluate the efficacy of wetting the pit to reduce the respirable dust exposure; and (4) determine if exposure increases with increasing depth of pit due to the walls of the pit blocking the cross wind ventilation

  11. Occurrence of ²¹⁰Po and biological effects of low-level exposure: the need for research.

    Science.gov (United States)

    Seiler, Ralph L; Wiemels, Joseph L

    2012-09-01

    Polonium-210 (²¹⁰Po) concentrations that exceed 1 Bq/L in drinking-water supplies have been reported from four widely separated U.S. states where exposure to it went unnoticed for decades. The radionuclide grandparents of ²¹⁰Po are common in sediments, and segments of the public may be chronically exposed to low levels of ²¹⁰Po in drinking water or in food products from animals raised in contaminated areas. We summarized information on the environmental behavior, biokinetics, and toxicology of ²¹⁰Po and identified the need for future research. Potential linkages between environmental exposure to ²¹⁰Po and human health effects were identified in a literature review. ²¹⁰Po accumulates in the ovaries where it kills primary oocytes at low doses. Because of its radiosensitivity and tendency to concentrate ²¹⁰Po, the ovary may be the critical organ in determining the lowest injurious dose for ²¹⁰Po. ²¹⁰Po also accumulates in the yolk sac of the embryo and in the fetal and placental tissues. Low-level exposure to ²¹⁰Po may have subtle, long-term biological effects because of its tropism towards reproductive and embryonic and fetal tissues where exposure to a single alpha particle may kill or damage critical cells. ²¹⁰Po is present in cigarettes and maternal smoking has several effects that appear consistent with the toxicology of ²¹⁰Po. Much of the important biological and toxicological research on ²¹⁰Po is more than four decades old. New research is needed to evaluate environmental exposure to ²¹⁰Po and the biological effects of low-dose exposure to it so that public health officials can develop appropriate mitigation measures where necessary.

  12. Low Level Exposure to GB Vapor in Air: Diagnosis/Dosimetry, Lowest Observable Effect Levels, Performance-Incapacitation, and Possible Delayed Effects

    National Research Council Canada - National Science Library

    1998-01-01

    ...: (I) A glass exposure chamber for whole-body exposure of unanesthetized guinea pigs and marmosets to low levels of OB vapor in air has been designed and constructed, and is in the implementation stage...

  13. Low-level lead exposure and autistic behaviors in school-age children.

    Science.gov (United States)

    Kim, Kyoung-Nam; Kwon, Ho-Jang; Hong, Yun-Chul

    2016-03-01

    The association between lead exposure and autism spectrum disorder is inconclusive. We hypothesized an association between higher blood lead concentrations and more autistic behaviors, including impaired social interactions and communication, stereotypical behaviors, and restricted interests, among school-age children. Data from 2473 Korean children aged 7-8years who had no prior history of developmental disorders were analyzed. Two follow-up surveys were conducted biennially until the children reached 11-12years of age. Blood lead concentrations were measured at every survey, and autistic behaviors were evaluated at 11-12years of age using the Autism Spectrum Screening Questionnaire (ASSQ) and Social Responsiveness Scale (SRS). The associations of blood lead concentration with ASSQ and SRS scores were analyzed using negative binomial, logistic, and linear regression models. Blood lead concentrations at 7-8years of age (geometric mean: 1.64μg/dL), but not at 9-10 and 11-12years of age, were associated with more autistic behaviors at 11-12years of age, according to the ASSQ (β=0.151; 95% confidence interval [CI]: 0.061, 0.242) and SRS (β=2.489; 95% CI: 1.378, 3.600). SRS subscale analysis also revealed associations between blood lead concentrations and social awareness, cognition, communication, motivation, and mannerisms. Even low blood lead concentrations at 7-8years of age are associated with more autistic behaviors at 11-12years of age, underscoring the need for continued efforts to reduce lead exposure. Copyright © 2016. Published by Elsevier B.V.

  14. Low-level laser therapy: Effects on human face aged skin and cell viability of HeLa cells exposed to UV radiation

    Directory of Open Access Journals (Sweden)

    Mezghani Sana

    2015-01-01

    Full Text Available Chronic and excessive exposure to UV radiation leads to photoaging and photocarcinogenesis. Adequate protection of the skin against the deleterious effects of UV irradiation is essential. Low-level laser therapy (LLLT is a light source in the red to near-infrared range that has been accepted in a variety of medical applications. In this study, we explored the effect of LLLT in human face aged skin and the cell viability of HeLa cells exposed to UV radiation. We found that LLLT significantly reduced visible wrinkles and the loss of firmness of facial skin in aging subjects. Additionally, treatment of cultured HeLa cells with LLLT prior to or post UVA or UVB exposure significantly protected cells from UV-mediated cell death. All results showed the beneficial effects of LLLT on relieving signs of skin aging and its prevention and protection of the cell viability against UV-induced damage.

  15. NTPR Radiation Exposure Reports

    Science.gov (United States)

    History Documents US Underground Nuclear Test History Reports NTPR Radiation Exposure Reports Enewetak Atoll Cleanup Documents TRAC About Who We Are Our Values History Locations Our Leadership Director Support Center Contact Us FAQ Sheet Links Success Stories Contracts Business Opportunities Current

  16. Doses from radiation exposure

    International Nuclear Information System (INIS)

    Menzel, H-G.; Harrison, J.D.

    2012-01-01

    Practical implementation of the International Commission on Radiological Protection’s (ICRP) system of protection requires the availability of appropriate methods and data. The work of Committee 2 is concerned with the development of reference data and methods for the assessment of internal and external radiation exposure of workers and members of the public. This involves the development of reference biokinetic and dosimetric models, reference anatomical models of the human body, and reference anatomical and physiological data. Following ICRP’s 2007 Recommendations, Committee 2 has focused on the provision of new reference dose coefficients for external and internal exposure. As well as specifying changes to the radiation and tissue weighting factors used in the calculation of protection quantities, the 2007 Recommendations introduced the use of reference anatomical phantoms based on medical imaging data, requiring explicit sex averaging of male and female organ-equivalent doses in the calculation of effective dose. In preparation for the calculation of new dose coefficients, Committee 2 and its task groups have provided updated nuclear decay data (ICRP Publication 107) and adult reference computational phantoms (ICRP Publication 110). New dose coefficients for external exposures of workers are complete (ICRP Publication 116), and work is in progress on a series of reports on internal dose coefficients to workers from inhaled and ingested radionuclides. Reference phantoms for children will also be provided and used in the calculation of dose coefficients for public exposures. Committee 2 also has task groups on exposures to radiation in space and on the use of effective dose.

  17. Efficacy of Royal Jelly in Modulating Radiation-Induced Liver Damage in Rats Subjected to Low Level of Gamma Radiation

    International Nuclear Information System (INIS)

    Ibrahim, N.K.

    2010-01-01

    Royal Jelly (RJ) is bee product, rich in proteins, vitamins, enzymes, minerals, hormones (trace elements of testosterone), lipids, glucides, niacin, pantothenic acid, biotin, inositol and folic acid, which may be beneficial in neutralizing the free oxygen radicals. The present study was carried out evaluate the radio-protective effect of Royal Jelly exposure of male Swiss albino rats to 1 Gy for 5 times day post day. Royal jelly was supplemented by gavage to rats at a dose of 150 mg/ kg body wt/ day for successive 10 days through exposure to gamma radiation 1 Gy x 5 time day post day. The dose of royal jelly is equivalent to daily human nutritional supplementation quantity. The result revealed that whole body gamma-irradiation of rats produced significant decrease in plasma total protein, albumin and globulin contents and significant increase in plasma alanine transaminase (ALT) and aspartate transaminase (AST) activity. However, plasma testosterone significantly decrease and follicle-stimulating hormone (FSH) and luteinising hormone (LH) significantly increased. Cholesterol (TC), triacyleglycerol (TAC), superoxide dismutase (SOD) and glutathione per oxidise (GSHPx) decreased whereas, malondialdehde (MDA) increased. Oral administration of the RJ exerted a noticeable amelioration of the radiation induced hormonal and biochemical changes according to the results of the present study. It could be concluded that RJ possess anti-oxidative potential that may protect the liver against ?-radiation induced acute oxidative toxicity. This protective effect might be mediated, at least in part, by the limitation of culprit free radicals and the amelioration of oxidative stress and also due to the synergistic relationship between the natural components found in RJ

  18. Creating a strategy for science-based national policy: Addressing conflicting views on the health risk of low-level ionizing radiation. Final report, Wingspread Conference

    International Nuclear Information System (INIS)

    McClellan, Roger O.; Apple, Martin A.

    1998-01-01

    Significant cancer risk for adults exposed to more than 100 millisieverts (10 REM) of ionizing radiation. More research on low-level ionizing radiation is needed in molecular and cellular mechanisms of injury and ongoing exposed populations. Implementation costs should be considered in regulating low-level ionizing radiation. Comparative risk assessment is a powerful tool for risk-based policy formation, and conflicting legal statutes should become harmonized for radiation regulation. More public dialog on low-level radiation is needed. A high level commission should evaluate radiation hazard control practices

  19. Assessment of Relevant Exposure Pathways in Scenario of Reuse of Very Low Level Radioactive Steel in Tunnel Constructions

    International Nuclear Information System (INIS)

    Hrncir, T.; Necas, V.

    2012-01-01

    Decommissioning process and related management of generated radioactive materials during this process became important topics during last several years because of continuously increasing number of nuclear power plant approaching the end of their lifetime. The very low level radioactive waste category includes considerable amount of materials arising from decommissioning. In line with international incentives of optimization of the waste management process, alternative concepts of recycling and reuse of materials are considered. One of these concepts of such optimization is the conditional release of materials with their subsequent recycling and reuse in industrial or nuclear sector. This paper is devoted to an option of recycling and reuse of conditionally released steel in industrial sector, specifically in motorway tunnel constructions. It is assumed that very low level radioactive steel would be released and reused in form of steel reinforcing components, such as steel nets and bars, assembled in primary and secondary lining of motorway tunnel. Assessment of exposure pathways relevant for construction, operation and post-operation period was performed. The computational tool VISIPLAN 3D ALARA was used for calculation of external individual effective dose for personnel constructing the tunnel and for members of the public driving through already built motorway tunnel. The simulation software GOLDSIM was used for the assessment of internal exposure pathways. GOLDSIM environment enables modelling of degradation processes and transport of radionuclides through unsaturated and saturated zone of subsoil. There are international recommendations available for the concept of release of radioactive materials into the environment derived from the principles that the individual effective dose received by critical individual must not exceed some tens of microSv/yr. Dose limits 10 microSv/yr or 50 microSv/yr considering specific conditions are stated in Slovak legislation

  20. Oxidative Stress and Genotoxicity of Long-Term Occupational Exposure to Low Levels of BTEX in Gas Station Workers

    Directory of Open Access Journals (Sweden)

    Feng Xiong

    2016-12-01

    Full Text Available Atmospheric benzene, toluene, ethylbenzene, and xylenes (BTEX can lead to multiple health injuries. However, what remains uncertain is the effect of long-term exposure to low levels of BTEX. Thus, we determined the BTEX levels in the air from the refueling and office areas in gas stations. Then we collected workers’ (200 refueling vs. 52 office workers peripheral blood samples to analyze the serum total-superoxide dismutase (T-SOD, glutathione (GSH, malondialdehyde (MDA, and 8-hydroxydeoxyguanosine (8-OHdG levels. DNA damage was analyzed by the comet assay and micronucleus test in buccal epithelial cells. We found that the levels of BTEX in refueling areas were significantly higher than those in office areas (p < 0.001. The serum T-SOD and GSH of refueling workers were significantly lower than those in office workers (p < 0.001. By contrast, the serum MDA and 8-OHdG of refueling workers were significantly higher than those of office workers (p < 0.001, MDA; p = 0.025, 8-OHdG. Furthermore, tail and Olive tail moments in refueling workers were longer (p = 0.004, tail moment; p = 0.001, Olive tail moment, and the micronucleus rate was higher (p < 0.001 than those in office workers. Taken together, long-term exposure to low levels of BTEX may reduce the antioxidant ability and increase the risk of DNA damage in refueling workers of gas stations.

  1. Sub-acute occupational hypersensitivity pneumonitis due to low-level exposure to diisocyanates in a secretary.

    Science.gov (United States)

    Schreiber, J; Knolle, J; Sennekamp, J; Schulz, K T; Hahn, J U; Hering, K G; Raulf-Heimsoth, M; Merget, R

    2008-09-01

    There is virtually no information in the literature about the exposure levels needed to induce hypersensitivity pneumonitis (HP) by diisocyanates. The present study reports a case of occupational HP due to diisocyanates after low-level exposure. A 53-yr-old female never-smoker developed progressive shortness of breath on exertion, cough, fatigue and flu-like symptoms shortly after she began work as a secretary of a car body repair shop. A diagnosis of HP was made 2 yrs later, based on a restrictive ventilatory defect, a reticulonodular and discrete ground-glass pattern on high-resolution computed tomography, lymphocytosis in bronchoalveolar lavage and specific immunoglobulin G antibodies to diisocyanate human serum albumin conjugates in the patient's serum. The diagnosis was confirmed by recovery after exposure cessation and deterioration after re-exposure. Ambient monitoring revealed air concentrations of different diisocyanate monomers below the detection limit in both the patient's work station and in front of the paint spray booths, with the exception of one measurement that showed 4,4-methylenediphenyl diisocyanate concentrations of 3 microg x m(-3) in front of one booth (corresponding to a total reactive isocyanate group concentration of 1 microg x m(-3)). The present authors conclude that concentrations of diisocyanates far below current exposure limits may induce hypersensitivity pneumonitis in susceptible subjects.

  2. Critical reevaluation of the dose-response relationships for carcinogenic effects of low-level ionizing radiation

    International Nuclear Information System (INIS)

    Upton, Arthur C.

    2002-01-01

    In recent decades, it has been customary, for radiation protection purposes, to assume that the overall risk of radiation- included cancer increases as a linear-nonthreshold function of the dose. The existing data do not exclude the existence of a threshold, however, and the dose-response relationship is known to vary depending on the type of cancer in question, the dose, dose rate and LET of the radiation, the age, sex and physiological state of the exposed individuals, and other variables, including the potential influence of adaptive responses and bystander effects at low doses. In light of advancing knowledge, therefore, the dose-response relationship for carcinogenic effects of low-level radiation has been reevaluated periodically by the National Council on Radiation Protection and Measurements, the International Commission of Radiological Protection, the United Nations Scientific Committee on the Effects of Atomic Radiation, the U.S. National Academy of Sciences Committee on the Effects of Atomic Radiation, the U.S. National Academy of Sciences, and other organizations. The most recent such reviews have generally found the weight of evidence to suggest that lesions which are precursors to cancer (i.e., mutations and chromosome aberrations), and certain types of cancer as well, may increase in frequency linearly aberrations), and certain types of cancer as well, may increase in frequency linearly with the dose in the low-dose domain. On this basis, it is concluded that no alternative dose-response model for the carcinogenic effects of low-level radiation is ore plausible than the linear-nonthreshold model, although other dose-response relationships cannot be excluded. (author)

  3. The effects of low-level ionising radiation on primary explant cultures of rainbow trout Pronephros

    International Nuclear Information System (INIS)

    Olwell, P.; Ni Shuilleabhain, S.; Mothersill, C.; Seymour, C.; Cottell, D.C.; Lyng, F.M.

    2004-01-01

    It has long been known that the haematopoietic tissue of mammals is one of the most radiosensitive tissues. In vitro studies on prawn have also shown that low doses of radiation has an extremely deleterious effect on cells cultured from this animal's blood forming tissues. This raises the question on the relative effects of radiation between animals from different species. One of the most important aquatic animals, from both an economic and ecologic point of view, is the fish. With this in mind, primary cultures of the blood forming tissues of rainbow trout were exposed to radiation followed by a morphological comparison between control and irradiated cultures. The cultured cells were characterised as macrophages following incubation with non-specific fluorescent beads and human apoptotic PMN. The cells demonstrated both specific and non-specific phagocytosis, by consuming the non-indigenous bodies, and were classified as phagocytic leucocytes. These cells were found in two morphological forms, stretched and rounded. It was shown that there was a commensurate increase in the number of stretched cells following application of radiation. Radiation was also shown to cause a dose-dependent increase in the amounts of apoptosis and necrosis in cells over time. The phagocytic efficacy of the irradiated leucocytes compared to controls was also investigated. (author)

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

    International Nuclear Information System (INIS)

    Upton, A.C.

    1987-01-01

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

  5. Genetic impact of low-level ionizing radiation: risk estimates for first and subsequent generations

    International Nuclear Information System (INIS)

    Abrahamson, S.

    1985-01-01

    This presentation is summarized as follows: (1) a discussion of the induced mutation rates/rad employed to derive central estimates for five major classes of genetic disease; (2) the expected first generation yield of mutations per million liveborn when both parents have received a gonadal exposure of 1 rad; (3) the expected yield of mutant offspring through all time from a single rad of parental exposure; (4) the impact in terms of effective years of life lost; and (5) a prediction of how many induced genetic disorders of each class should be found among the offspring of the A-bomb survivors using the risk estimates presented. 15 references, 6 tables

  6. Atmospheric ions and probable indirect biological effect of low-level radiation

    International Nuclear Information System (INIS)

    Spurny, Z.

    1984-01-01

    The problem is discussed of the health consequences of low radiation doses (of less than 0.01 Gy). Owing to natural radioactivity and cosmic radiation, ions are formed in the atmosphere which may thus indirectly mediate the effects of ionizing radiation on the organism. The rate of ion formation is approximately 6.1 ion pairs/cm 3 .s and their number will not exceed 10 3 ions/cm 3 . In an environment where artificial radioactive sources are used, the ion concentration may reach up to 10 5 ions/cm 3 . The effect of ions on man may be divided into several types: 1. effect on mental state (behaviour, fatigue, headaches); 2. effect on the cardiovascular system; 3. effect on the bronchial system;and 4. effect on physiological processes, e.g., secretion by endocrine glands. It is not yet known whether the biological effect of small (fast) ions is a function of their electric charge only or of their kinetic energy as well. The view is discussed that low radiation doses through indirect effects have favourable and beneficial influence on the human organism. (M.D.)

  7. New method of radiation measurement at carbon isotope 14 low level in an environmental atmospheric sampling

    International Nuclear Information System (INIS)

    Tormos, J.

    2009-01-01

    A new method of preparation is proposed to extract the atmospheric carbon trapped in the solution of soda coming from air sampling in environment with a carbon-14 bubbler (type H.A.G. 7000). It is based on the neutralisation of the global soda solution got from bubbling pots by nitric acid, the complete desorption of the carbon under gaseous oxidized form (CO 2 ) and its trapping in a only capacity containing a reactive. The whole of the device is scanned by air at steady rate. A test catch of the reactive and of the trapped carbon dioxide is then blended to a glistening liquid (Permafluor E+) and measured in beta counting by scintillation in liquid medium with a counter for the measurement of low energy beta emitters at very low level of activity (Quantulus type). this method allows to get a limit of detection equal to 5 mBq/m 3 for the atmospheric organic carbon. The principal interest of this method is its quickness and simplicity of setting in motion for a measurement of 14 C in the atmospheric carbon dioxide at a level of natural activity. (N.C.)

  8. Dermal damage promoted by repeated low-level UV-A1 exposure despite tanning response in human skin.

    Science.gov (United States)

    Wang, Frank; Smith, Noah R; Tran, Bao Anh Patrick; Kang, Sewon; Voorhees, John J; Fisher, Gary J

    2014-04-01

    Solar UV irradiation causes photoaging, characterized by fragmentation and reduced production of type I collagen fibrils that provide strength to skin. Exposure to UV-B irradiation (280-320 nm) causes these changes by inducing matrix metalloproteinase 1 and suppressing type I collagen synthesis. The role of UV-A irradiation (320-400 nm) in promoting similar molecular alterations is less clear yet important to consider because it is 10 to 100 times more abundant in natural sunlight than UV-B irradiation and penetrates deeper into the dermis than UV-B irradiation. Most (approximately 75%) of solar UV-A irradiation is composed of UV-A1 irradiation (340-400 nm), which is also the primary component of tanning beds. To evaluate the effects of low levels of UV-A1 irradiation, as might be encountered in daily life, on expression of matrix metalloproteinase 1 and type I procollagen (the precursor of type I collagen). In vivo biochemical analyses were conducted after UV-A1 irradiation of normal human skin at an academic referral center. Participants included 22 healthy individuals without skin disease. Skin pigmentation was measured by a color meter (chromometer) under the L* variable (luminescence), which ranges from 0 (black) to 100 (white). Gene expression in skin samples was assessed by real-time polymerase chain reaction. Lightly pigmented human skin (L* >65) was exposed up to 4 times (1 exposure/d) to UV-A1 irradiation at a low dose (20 J/cm2), mimicking UV-A levels from strong sun exposure lasting approximately 2 hours. A single exposure to low-dose UV-A1 irradiation darkened skin slightly and did not alter matrix metalloproteinase 1 or type I procollagen gene expression. With repeated low-dose UV-A1 irradiation, skin darkened incrementally with each exposure. Despite this darkening, 2 or more exposures to low-dose UV-A1 irradiation significantly induced matrix metalloproteinase 1 gene expression, which increased progressively with successive exposures. Repeated UV-A1

  9. Kinetics of granulocytic and erythroid progenitor cells are affected differently by short-term, low-level benzene exposure

    Energy Technology Data Exchange (ETDEWEB)

    Dempster, A.M.; Snyder, C.A. (New York Univ. Medical Center, NY (United States). Inst. of Environmental Medicine)

    1991-09-01

    Mice were exposed to either air or 10 ppm benzene for 6 h/d X 5 d. Immediately after the last exposure, mice were injected, i.v., with either saline or hydroxyurea (HU). The dose of HU was sufficient to kill hematopoietic cells in or near S-phase of the cell cycle and sufficient to synchronize the surviving populations of hematopoietic cells. Three days after benzene exposure, CFU-E numbers had declined to 50% of control values while CFU-GM numbers were equal to control values at this time. The benzene exposures were sufficient to double the percentage of CFU-E in S-phase but produced no such increase among CFU-Gm. During 3 days of recovery from benzene exposure and HU treatment, the CFU-E population expanded 30-fold while the CFU-GM population expanded less than 3-fold. Following benzene exposure and HU treatment, both progenitor cells produced elevated numbers of their respective progeny. When CFU-E from benzene-exposed mice were cultured with varying concentrations of erythropoietin (EPO), the response at maximal EPO concentration was 66% of the response by control CFU-E. This strongly suggests that the CFU-E populations from benzene-exposed mice had been depleted of cells in or near S-phase. The results indicate that CFU-GM respond to low-level benzene exposure by increasing their rate of differentiation but not their rate of proliferation, while CFU-E respond by increasing both their rates of differentiation and proliferation. We speculate that it is the increase in CFU-E proliferation that renders these cells more susceptible to benzene than their granulocytic counterparts, especially those CFU-E at or near the S-phase of the cell cycle. (orig.).

  10. Doses from radiation exposure

    CERN Document Server

    Menzel, H G

    2012-01-01

    Practical implementation of the International Commission on Radiological Protection's (ICRP) system of protection requires the availability of appropriate methods and data. The work of Committee 2 is concerned with the development of reference data and methods for the assessment of internal and external radiation exposure of workers and members of the public. This involves the development of reference biokinetic and dosimetric models, reference anatomical models of the human body, and reference anatomical and physiological data. Following ICRP's 2007 Recommendations, Committee 2 has focused on the provision of new reference dose coefficients for external and internal exposure. As well as specifying changes to the radiation and tissue weighting factors used in the calculation of protection quantities, the 2007 Recommendations introduced the use of reference anatomical phantoms based on medical imaging data, requiring explicit sex averaging of male and female organ-equivalent doses in the calculation of effecti...

  11. Chromosome aberration analysis in persons exposed to low-level radiation from the JCO criticality accident in Tokai-mura

    International Nuclear Information System (INIS)

    Sasaki, Masao S.; Hayata, Isamu; Kamada, Nanao; Kodama, Yoshiaki; Kodama, Seiji

    2001-01-01

    Chromosome aberrations were studied in peripheral blood lymphocytes of 43 persons who were exposed to low-level radiation of mixed neutrons and γ-rays resulting from the JCO criticality accident. When the age-adjusted frequencies of dicentric and ring chromosomes were compared with the dose calibration curve established in vitro for 60 Co γ-rays as a reference radiation, a significant correlation was observed between the chromosomally estimated doses and the documented doses evaluated by physical means. The regression coefficient of the chromosomal doses against the documented doses, 1.47±0.33, indicates that the relative biological effectiveness of fission neutrons at low doses is considerably higher than that currently adopted in the radiation protection standard. (author)

  12. The association between low level exposures to ambient air pollution and term low birth weight: a retrospective cohort study

    Directory of Open Access Journals (Sweden)

    Stieb David

    2006-02-01

    trimester to relatively low levels of some air pollutants may be associated with a reduction in birth weight in term-born infants. These findings have implications for the development of effective risk management strategies to minimize the public health impacts for pregnant women.

  13. Cellulose acetobutyrate films and beryllium oxide discs for low-level radiation monitoring

    International Nuclear Information System (INIS)

    Ventura, S.A.; Kleinschmidt, D.E.; Mbu, J.B.

    1976-01-01

    The effect of mylar films on the attenuation of alpha particle energy and the production of etchable tracks in cellulose acetobutyrate was studied. A model developed predicts a 15-μ optimum mylar film thickness, while experimental results indicated a 22.8-μ optimum. The effect of alpha particle and potassium hydroxide solution interaction with CAB was reviewed and process improvements suggested. The TSEE response of BeO discs to tritium at 5.0 mCi/m 3 for up to 15-hr exposure was also investigated. An average TSEE/β ratio of 0.02 was obtained

  14. Effects of low-level sarin and cyclosarin exposure on white matter integrity in Gulf War Veterans.

    Science.gov (United States)

    Chao, Linda L; Zhang, Yu; Buckley, Shannon

    2015-05-01

    We previously found evidence of reduced gray and white matter volume in Gulf War (GW) veterans with predicted low-level exposure to sarin (GB) and cyclosarin (GF). Because loss of white matter tissue integrity has been linked to both gray and white matter atrophy, the current study sought to test the hypothesis that GW veterans with predicted GB/GF exposure have evidence of disrupted white matter microstructural integrity. Measures of fractional anisotropy and directional (i.e., axial and radial) diffusivity were assessed from the 4T diffusion tensor images (DTI) of 59 GW veterans with predicted GB/GF exposure and 59 "matched" unexposed GW veterans (mean age: 48 ± 7 years). The DTI data were analyzed using regions of interest (ROI) analyses that accounted for age, sex, total brain gray and white matter volume, trauma exposure, posttraumatic stress disorder, current major depression, and chronic multisymptom illness status. There were no significant group differences in fractional anisotropy or radial diffusivity. However, there was increased axial diffusivity in GW veterans with predicted GB/GF exposure compared to matched, unexposed veterans throughout the brain, including the temporal stem, corona radiata, superior and inferior (hippocampal) cingulum, inferior and superior fronto-occipital fasciculus, internal and external capsule, and superficial cortical white matter blades. Post hoc analysis revealed significant correlations between higher fractional anisotropy and lower radial diffusivity with better neurobehavioral performance in unexposed GW veterans. In contrast, only increased axial diffusivity in posterior limb of the internal capsule was associated with better psychomotor function in GW veterans with predicted GB/GF exposure. The finding that increased axial diffusivity in a region of the brain that contains descending corticospinal fibers was associated with better psychomotor function and the lack of significant neurobehavioral deficits in veterans

  15. An in vitro study of the effects of low-level laser radiation on human blood

    Science.gov (United States)

    Siposan, Dan G.; Lukacs, Adalbert

    2003-12-01

    In the last time the study of the effects of LLLR on the blood is considered to be a subject of great importance in elucidating the mechanisms of action between LLLR and biologic tissues. Different methods of therapy by blood irradiation have been developed and used in clinical purposes with benefic effects. This study investigates some in vitro effects of LLLR on some selected rheologic indices of human blood. After establishing whether or not damaging effects could appear due to laser irradiation of the blood, we tried to find a new method for rejuvenating the blood preserved in MacoPharma-type bags. Blood samples were obtained from adult regular donors (volunteers). HeNe laser and laser diodes were used as radiation source, in a wide range of wavelengths, power densities, doses and other parameters of irradiation protocol. In the first series of experiments we established that LLLR does not alter the fresh blood from healthy donors, for doses between 0 and 10 J/cm3 and power densities between 30 and 180 mW/cm3. In the second series of experiments we established that LLLR does have, in some specific conditions, a revitalizing effect on the erythrocytes in preserved blood. We concluded that laser irradiation of the preserved blood, following a selected protocol of irradiation, could be used as a new method to improve the performances of preservation: prolonging the period of storage and blood rejuvenation before transfusion.

  16. Neoplasms in dogs receiving low-level gamma radiation during pre- and postnatal development

    International Nuclear Information System (INIS)

    Benjamin, S.A.; Thomassen, R.W.; Hargis, A.M.; Angleton, G.M.; Lee, A.C.

    1978-01-01

    Mortality because of neoplasia was examined in Segment III dogs exposed to 0,20, or 100 R of 60 Co gamma radiation in prenatal and early postnatal life. During the inital 10 years of the experiment (through January 31, 1978) 20 dogs died or were killed because of neoplasia, 19 having been irradiated. Tumors in these 19 irradiated dogs included 5 malignant lymphomas, 8 carcinomas (2 of mammary origin, 2 of prostatic origin, and 1 each or oral mucosa, ovary, urinary bladder, and thyroid origin), 4 sarcomas (2 hemangiosarcomas, 1 fibrosarcoma and 1 mast cell sarcoma), 1 astrocytoma, and 1 hepatocellular adenoma. Neoplasms occurred in all irradiated groups except 8 dpc (20 and 100R) and 70 dpp (100R). Eleven neoplasms developed in dogs irradiated perinatally (55 dpc or 2 dpp) with 20 or 100R. Four of the tumors in the perinatally irradiated dogs were detected before 2 years of age. The earliest death was at 3 months, because of an astrocytoma. A single sham-irradiated dog died or a malignant tumor, a mammary carcinoma. Preliminary analyses point to three findings of particular interest: the preponderance of neoplasms causing death or euthanasia occurred in irradiated dogs, the unusual finding of four deaths because of neoplasia prior to 2 years of age in perinatally irradiated dogs, and the occurrence of five malignant lymphomas in this relatively small irradiated population

  17. Dust Propagation and Radiation In the Presence of a Low-level Jet in Central China on March 17, 2010

    Science.gov (United States)

    McDowell, B. K.; Chen, S. H.

    2014-12-01

    Suspended dust in the air can directly change the energy budget in the atmosphere and at the surface through scattering and absorption of radiation. Thus, dust can potentially modify the development of weather systems. To explore the dust-radiation effects on weather systems, a dust model was developed based on the Weather Research and Forecasting (WRF) model. The calculations of dust processes in the WRF dust model include emission, advection, boundary layer mixing, cumulus mixing, dust-radiation interaction, wet scavenging, and sedimentation. Due to a high vertical spatial resolution near the surface a time splitting method was applied to the calculation of dust sedimentation to relax the numerical time step. The "Hexi Corridor" is the historical name given to a string of oases along the northern slope of the Tibetan Plateau that formed a relatively easy transportation route between eastern China and central Asia. As trade developed over the centuries, this route became known as the Silk Road. This corridor also marks the transition from the relatively flat Gobi desert area in northern China to the elevated mountains of the Tibetan Plateau. These mountains present a southern barrier to the paths of dust storms that develop during spring outbreaks of the Mongolian Cyclone. In March of 2010, a series of dust storms developed in the Gobi Desert north of the Hexi Corridor that transported massive amounts of dust eastward to central and northeastern China, Korea and Japan. On March 17 during this event, a low-level jet developed along the northern perimeter of the Plateau, in alignment with upper level winds and the Hexi Corridor. Over the course of the day, a well-defined short-duration dust plume was emitted in the southern Gobi desert area and was transported over 1300 km in a southeast direction, over the Loess Plateau and into the Gansu Province. In this study, the interactions of synoptic conditions with regional topography that led to the development of the low-level

  18. Risks and management of radiation exposure.

    Science.gov (United States)

    Yamamoto, Loren G

    2013-09-01

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

  19. Serum metabolome biomarkers associate low-level environmental perfluorinated compound exposure with oxidative /nitrosative stress in humans.

    Science.gov (United States)

    Wang, Xiaofei; Liu, Liangpo; Zhang, Weibing; Zhang, Jie; Du, Xiaoyan; Huang, Qingyu; Tian, Meiping; Shen, Heqing

    2017-10-01

    Previous in vivo and in vitro studies have linked perfluorinated compound (PFC) exposure with metabolic interruption, but the inter-species difference and high treatment doses usually make the results difficult to be extrapolated to humans directly. The best strategy for identifying the metabolic interruption may be to establish the direct correlations between monitored PFCs data and metabolic data on human samples. In this study, serum metabolome data and PFC concentrations were acquired for a Chinese adult male cohort. The most abundant PFCs are PFOA and PFOS with concentration medians 7.56 and 12.78 nM, respectively; in together they count around 81.6% of the total PFCs. PFC concentration-related serum metabolic profile changes and the related metabolic biomarkers were explored by using partial least squares-discriminant analysis (PLS-DA). Respectively taking PFOS, PFOA and total PFC as the classifiers, serum metabolome can be differentiated between the lowest dose group (1st quartile PFCs) and the highest PFC dose group (4th quartile PFCs). Ten potential PFC biomarkers were identified, mainly involving in pollutant detoxification, antioxidation and nitric oxide (NO) signal pathways. These suggested that low-level environmental PFC exposure has significantly adverse impacts on glutathione (GSH) cycle, Krebs cycle, nitric oxide (NO) generation and purine oxidation in humans. To the best of our knowledge, this is the first report investigating the association of environmental PFC exposure with human serum metabolome alteration. Given the important biological functions of the identified biomarkers, we suggest that PFC could increase the metabolism syndromes risk including diabetes and cardiovascular diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. A case of tongue edema associated with radiation-induced ulcer with low level of C1 inhibitor activity

    International Nuclear Information System (INIS)

    Hata, Tsuyoshi; Hosoda, Masaru

    2003-01-01

    A 66-year-old man became aware of sudden swelling of the tongue with swallowing disturbance. He had a medical history of tongue cancer treated by interstitial radiotherapy and had undergone a cytological examination of an ulcer on the right side of the tongue three weeks earlier because of suspected recurrence. The cytological examination result was class I with no malignant findings. Angioneurotic edema, so-called ''Quincke's edema'', associated with radiation-induced ulcer of the tongue, was diagnosed. Tranexamic acid, d-chlorpheniramine maleate, and epinephrine were administered. After six days, the tongue edema had almost disappeared. Laboratory examination revealed a low level of C1 inhibitor activity with normal levels of CH50, C1, C3, and C4 at the time of swelling. Hereditary angioneurotic edema with absence of hereditary trait was suspected based on the sudden edema attack and low level of C1 inhibitor activity. The C1 inhibitor activity returned to normal after disappearance of the tongue edema. (author)

  1. An exposure assessment of radionuclide emissions associated with potential mixed-low level waste disposal facilities at fifteen DOE sites

    International Nuclear Information System (INIS)

    Lombardi, D.A.; Socolof, M.L.

    1996-01-01

    A screening method was developed to compare the doses received via the atmospheric pathway at 15 potential DOE MLLW (mixed low-level waste) sites. Permissible waste concentrations were back calculated using the radioactivity NESHAP (National Emissions Standards for Hazardous Air Pollutants) in 40 FR 61 (DOE Order 5820.2A performance objective). Site-specific soil and meteorological data were used to determine permissible waste concentrations (PORK). For a particular radionuclide, perks for each site do not vary by more than one order of magnitude. perks of 14 C are about six orders of magnitude more restrictive than perks of 3 H because of differences in liquid/vapor partitioning, decay, and exposure dose. When comparing results from the atmospheric pathway to the water and intruder pathways, 14 C disposal concentrations were limited by the atmospheric pathway for most arid sites; for 3 H, the atmospheric pathway was not limiting at any of the sites. Results of this performance evaluation process are to be used for planning for siting of disposal facilities

  2. CYP2E1 epigenetic regulation in chronic, low-level toluene exposure: Relationship with oxidative stress and smoking habit

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Garza, Octavio, E-mail: ojimenezgarza@ugto.mx [Health Sciences Division, University of Guanajuato Campus León, Blvd. Puente del Milenio 1001, Fracción del Predio San Carlos, C.P. 37670 León, Guanajuato (Mexico); Baccarelli, Andrea A.; Byun, Hyang-Min [Laboratory of Environmental Epigenetics, Department of Environmental Health, Harvard T.H. Chan School of Public Health, 677 Huntington Avenue, Boston, MA 02115 (United States); Márquez-Gamiño, Sergio [Health Sciences Division, University of Guanajuato Campus León, Blvd. Puente del Milenio 1001, Fracción del Predio San Carlos, C.P. 37670 León, Guanajuato (Mexico); Barrón-Vivanco, Briscia Socorro [Environmental Toxicology and Pollution Laboratory, Nayarit Autonomous University, Av. Ciudad de la Cultura s/n, “Amado Nervo”, Tepic, Nayarit C.P. 63155 (Mexico); Albores, Arnulfo [Department of Toxicology, CINVESTAV, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, 07360 Mexico DF (Mexico)

    2015-08-01

    Background: CYP2E1 is a versatile phase I drug-metabolizing enzyme responsible for the biotransformation of most volatile organic compounds, including toluene. Human toluene exposure increases CYP2E1 mRNA and modifies its activity in leucocytes; however, epigenetic implications of this interaction have not been investigated. Goal: To determine promoter methylation of CYP2E1 and other genes known to be affected by toluene exposure. Methods: We obtained venous blood from 24 tannery workers exposed to toluene (mean levels: 10.86 +/− 7 mg/m{sup 3}) and 24 administrative workers (reference group, mean levels 0.21 +/− 0.02 mg/m{sup 3}) all of them from the city of León, Guanajuato, México. After DNA extraction and bisulfite treatment, we performed PCR-pyrosequencing in order to measure methylation levels at promoter region of 13 genes. Results: In exposed group we found significant correlations between toluene airborne levels and CYP2E1 promoter methylation (r = − .36, p < 0.05), as well as for IL6 promoter methylation levels (r = .44, p < 0.05). Moreover, CYP2E1 promoter methylation levels where higher in toluene-exposed smokers compared to nonsmokers (p = 0.009). We also observed significant correlations for CYP2E1 promoter methylation with GSTP1 and SOD1 promoter methylation levels (r = − .37, p < 0.05 and r = − .34, p < 0.05 respectively). Conclusion: These results highlight the importance of considering CYP2E1 epigenetic modifications, as well as its interactions with other genes, as key factors for unraveling the sub cellular mechanisms of toxicity exerted by oxidative stress, which can initiate disease process in chronic, low-level toluene exposure. People co-exposed to toluene and tobacco smoke are in higher risk due to a possible CYP2E1 repression. - Highlights: • We investigated gene-specific methylation in persons chronically exposed to toluene. • In a previous study, a reduced CYP2E1 activity was observed in these participants. • CYP2E1

  3. CYP2E1 epigenetic regulation in chronic, low-level toluene exposure: Relationship with oxidative stress and smoking habit

    International Nuclear Information System (INIS)

    Jiménez-Garza, Octavio; Baccarelli, Andrea A.; Byun, Hyang-Min; Márquez-Gamiño, Sergio; Barrón-Vivanco, Briscia Socorro; Albores, Arnulfo

    2015-01-01

    Background: CYP2E1 is a versatile phase I drug-metabolizing enzyme responsible for the biotransformation of most volatile organic compounds, including toluene. Human toluene exposure increases CYP2E1 mRNA and modifies its activity in leucocytes; however, epigenetic implications of this interaction have not been investigated. Goal: To determine promoter methylation of CYP2E1 and other genes known to be affected by toluene exposure. Methods: We obtained venous blood from 24 tannery workers exposed to toluene (mean levels: 10.86 +/− 7 mg/m 3 ) and 24 administrative workers (reference group, mean levels 0.21 +/− 0.02 mg/m 3 ) all of them from the city of León, Guanajuato, México. After DNA extraction and bisulfite treatment, we performed PCR-pyrosequencing in order to measure methylation levels at promoter region of 13 genes. Results: In exposed group we found significant correlations between toluene airborne levels and CYP2E1 promoter methylation (r = − .36, p < 0.05), as well as for IL6 promoter methylation levels (r = .44, p < 0.05). Moreover, CYP2E1 promoter methylation levels where higher in toluene-exposed smokers compared to nonsmokers (p = 0.009). We also observed significant correlations for CYP2E1 promoter methylation with GSTP1 and SOD1 promoter methylation levels (r = − .37, p < 0.05 and r = − .34, p < 0.05 respectively). Conclusion: These results highlight the importance of considering CYP2E1 epigenetic modifications, as well as its interactions with other genes, as key factors for unraveling the sub cellular mechanisms of toxicity exerted by oxidative stress, which can initiate disease process in chronic, low-level toluene exposure. People co-exposed to toluene and tobacco smoke are in higher risk due to a possible CYP2E1 repression. - Highlights: • We investigated gene-specific methylation in persons chronically exposed to toluene. • In a previous study, a reduced CYP2E1 activity was observed in these participants. • CYP2E1 promoter

  4. Radiation hormesis: Beneficial effects of exposure to low levels of ionizing radiation. A critical review

    International Nuclear Information System (INIS)

    Koch, J.; Schlesinger, T.

    2002-01-01

    Hormesis is defined as the stimulating effect of low doses of agents that cause an inhibiting effect at high doses. The hormesis hypothesis states that most chemical and physical agents may stimulate biological effects at doses lower than a threshold, while they are toxic at doses higher than this threshold. Since the eighties of the nineties century multiple evidences of hormetic responses have been reported in the scientific literature

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

    International Nuclear Information System (INIS)

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

    1995-01-01

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

  6. Staff radiation exposure in radiation diagnostics

    International Nuclear Information System (INIS)

    Khakimova, N.U.; Malisheva, E.Yu.; Shosafarova, Sh.G.

    2010-01-01

    Present article is devoted to staff radiation exposure in radiation diagnostics. Data on staff radiation exposure obtained during 2005-2008 years was analyzed. It was found that average individual doses of staff of various occupations in Dushanbe city for 2008 year are at 0.29-2.16 mSv range. They are higher than the average health indicators but lower than maximum permissible dose. It was defined that paramedical personnel receives the highest doses among the various categories of staff.

  7. Bases for establishing radiation exposure limits

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1977-01-01

    It is an essential requirement of good radiation protection that all unnecessary exposure of people should be avoided and that any necessary exposure, whether of workers or of members of the general public, should be minimised. It is, however, an additional requirement that such necessary exposures should not exceed certain stated limits. These principles are based on the possibility that even the smallest exposures may involve some risk of harm, that any risk of harm should be justifiable by the circumstances necessitating it, and that risk should always be limited to an appropriately low level. The bases for establishing exposure limits must therefore involve an assessment of the risk involved in any form of radiation exposure, and an opinion as to the degree of safety that should be ensured in circumstances which necessitate any occupational or public exposure to radiation. There is increasing quantitative evidence on the frequency on which harm, and particularly the induction of malignancies, may be caused in people exposed to radiation at high doses; and somewhat clearer bases than previously for inferring the possible frequencies at low doses. It is therefore easier to assess the degree of safety ensured by restricting radiation exposure to particular levels. The degree of safety which should be regarded as appropriate in different circumstances remains a matter for review, but suggestions are made as to levels which would be advocated by informed opinion, and the exposure limits which would correspond to these. It is clear also that a comparable degree of safety should be ensured whether the radiation exposure involves the whole body more of less uniformly, or individual tissues or organs selectively. Increasing epidemiological evidence is available on the relative sensitivity to radiation induction of malignancies in a number of organs, and to the apparently much lower sensitivity of other organs; and experimental evidence in animals allows a comparable

  8. Cytogenetic evaluation of hospital workers occupationally exposed to low levels of ionizing radiation. Assessment of two cytogenetic procedures: accumulated dosimetry versus radiosensitivity

    International Nuclear Information System (INIS)

    Garcia-Sagredo, J. M.; Villalon, C.; Lopez-Abente, G.; Arranz, L.; Ferro, M. T.; Ferrando, P.; Pollan, M.; Aragones, N.; Ferrer, N.; Sastre, J. M.

    2004-01-01

    We try to establish a cumulative ionising radiation (IR) biologicla dosimetry in occupationally exposed workers as a routine health tes, analysing chromosome translocations. 100 hospital workers occupationally exposed to low levels of X-ray, g-ray and radioactive isotopes are included in this study. Blood samples were cultured for cytogenetic analysis. Chromosome translocatiosn were scored using whole chromosome paint probes cocktail (Vysis) for chromosomes 1, 2, 3, 4, 5 and 6. Furthermore, a personal detailed interview about confounding factors, as tobacco smoking X-ray examination, occupational exposure to chemotherapeutics agents and solvents, electromagnetic fields exposure, and others was done. Our results showed that there is no statistical association between cumulative doses of IRE, type of LET and chromosome translocation rate. For the contraty, we have found a translocation risk increase related with IR equivalent dose rate, independently of the time of exposure and age. Those workers receiving 1mSv/year or more vs<1mSv/year show a relative risk of 2.56 (95% confidence interval 1.10-5.95). A comparison of translocationrate and different confounding factors suggest a relative risk increase in intensive users of mobile phones. Other exposures as tobacco smoking solvents, UV radiation anaesthetic gases and any other confounding factors have not shown assocaition with translocation rate. At the same time, we try to analyse radiosensitivity through the CBMN-test (cytokinesis block micronucelus test). Results on CBMN are in progress. Finally we try to asses the two cytogentic procedures as the most suitable routine health test in radiation occupational protection. (Author)

  9. G2 repair and chromosomal damage in lymphocytes from workers occupationally exposed to low-level ionizing radiation

    Directory of Open Access Journals (Sweden)

    J PINCHEIRA

    1999-01-01

    Full Text Available The effect of the G2 repair of chromosomal damage in lymphocytes from workers exposed to low levels of X- or g-rays was evaluated. Samples of peripheral blood were collected from 15 radiation workers, 20 subjects working in radiodiagnostics, and 30 healthy control donors. Chromosomal aberrations (CA were evaluated by scoring the presence of chromatid and isochromatid breaks, dicentric and ring chromosomes in lymphocytes with/without 5mM caffeine plus 3mM-aminobenzamide (3-AB treatment during G2. Our results showed that the mean value of basal aberrations in lymphocytes from exposed workers was higher than in control cells (p< 0.001. The chromosomal damage in G2, detected with caffeine plus 3-AB treatment was higher than the basal damage (untreated conditions, both in control and exposed populations (p< 0.05. In the exposed workers group, the mean value of chromosomal abnormalities in G2 was higher than in the control (p< 0.0001. No correlation was found between the frequency of chromosome type of aberrations (basal or in G2, and the absorbed dose. Nevertheless, significant correlation coefficients (p< 0.05 between absorbed dose and basal aberrations yield (r = 0.430 or in G2 (r = 0.448 were detected when chromatid breaks were included in the total aberrations yield. Under this latter condition no significant effect of age, years of employment or smoking habit on the chromosomal aberrations yield was detected. However, analysis of the relationship between basal aberrations yield and the efficiency of G2 repair mechanisms, defined as the percentage of chromosomal lesions repaired in G2, showed a significant correlation coefficient (r = -0.802; p< 0.001. These results suggest that in addition to the absorbed dose, the individual G2 repair efficiency may be another important factor affecting the chromosomal aberrations yield detected in workers exposed to low-level ionizing radiation

  10. Low-level exposure of guinea pigs and marmosets to sarin vapour in air: Lowest-observable-adverse-effect level (LOAEL) for miosis

    NARCIS (Netherlands)

    Helden, H.P.M. van; Trap, H.C.; Kuijpers, W.C.; Oostdijk, J.P.; Benschop, H.P.; Langenberg, J.P.

    2004-01-01

    The purpose of this pilot study was to indicate, for low-level exposure of conscious guinea pigs and marmoset monkeys to sarin vapour in air, the lowest-observable-adverse-effect level (LOAEL) of sarin for miosis. This is the concentration × time (C·t) value (t = 5 h) of exposure at which miosis

  11. Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site

    International Nuclear Information System (INIS)

    Miller, J.; Shafer, D.; Gray, K.; Church, B.; Campbell, S.; Holz, B.

    2005-01-01

    This study has shown that, based upon measurements from industry standard radiation detection instruments, such as the RS model RSS-131 PICs in a controlled configuration, a person may be exposed to gamma radiation above background when in close proximity to some LLW trucks. However, in approximately half (47.7 percent) the population of trucks measured in this study, a person would receive no exposure above background at a distance of 1.0 m (3.3 ft) away from a LLW truck. An additional 206 trucks had net exposures greater than zero, but equal to or less than 1 (micro)R/h. Finally, nearly 80 percent of the population of trucks (802 of 1,012) had net exposures less than or equal to 10 (micro)R/h. Although there are no shipping or exposure standards at 1.0 m (3.3 ft) distance, one relevant point of comparison is the DOT shipping standard of 10 mrem/h at 2.0 m (6.6 ft) distance. Assuming a one-to-one correspondence between Roentgens and Rems, then 903 trucks (89.2 percent of the trucks measured) were no greater than one percent of the DOT standard at 1.0 m (3.3 ft). Had the distance at which the trucks been measured increased to 2.0 m (6.6 ft), the net exposure would be even less because of the increase in distance between the truck and the receptor. However, based on the empirical data from this study, the rate of decrease may be slower than for either a point or line source as was done for previous studies (Gertz, 2001; Davis et al., 2001). The highest net exposure value at 1.0 m (3.3 ft) distance, 11.9 mR/h, came from the only truck with a value greater than 10 mR/h at 1.0 m (3.3 ft) distance

  12. Prenatal exposure to low-level methylmercury alters the child's fine motor skills at the age of 18 months.

    Science.gov (United States)

    Prpić, Igor; Milardović, Ana; Vlašić-Cicvarić, Inge; Špiric, Zdravko; Radić Nišević, Jelena; Vukelić, Petar; Snoj Tratnik, Janja; Mazej, Darja; Horvat, Milena

    2017-01-01

    To compare motor, cognitive and language characteristics in children aged 18 months who were prenatally exposed to low-level methyl-mercury (MeHg), and to analyze the eventual differences in these characteristics in relation to cord blood THg concentration. The total number of 205 child-mother pairs was included in the study, and total cord blood mercury was measured in 198 of them. Out of the 198 already measured samples, 47 of them have also been tested for methyl-mercury in cord blood. Data regarding the 47 samples of MeHg levels has been used for calculating the correlation between cord blood THg and cord blood MeHg. MeHg and THg showed a significant correlation (r=0.95, pmotor, cognitive and language skills were conducted on 168 children using The Bayley Scales of Infant and Toddler Development, Third Edition (BSID-III). Regarding the cord blood THg concentration, 135 children were divided in 4 quartile groups. Their neurodevelopmental characteristics have been compared. The cord blood THg concentration median and inter-quartile range was 2.98ng/g (1.41-5.61ng/g). There was a negative correlation between cord blood THg concentration and fine motor skills (rho=-0.22, p=0.01). It is evident that children grouped in 2nd ,3rd and 4th quartile had statistically significant lower fine motor skills assessment related to those grouped in 1st quartile (2nd quartile -1.24, p=0.03; 3rd quartile -1.28, p=0.03; 4th quartile -1.45, p=0.01). The differences in fine motor skills assessments between children in 2nd and 3rd and 3rd and 4th quartile were not statistically significant. Intrauterine exposure to low-level THg (MeHg) is associated with alterations in fine motor skills at the age of 18 months. Copyright © 2016. Published by Elsevier Inc.

  13. Pregnancy and radiation exposure

    International Nuclear Information System (INIS)

    Trott, K.H.; Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Neuherberg

    1978-01-01

    In confirmed or presumptive pregnancy it is especially critical to determine the indications for X-ray examination. This assumes that every young woman, before an examination in the pelvic region, be asked explicity when her last normal period was. Examinations of the pelvis which are not acutely necessary should be postponed until the first 10 days after menstruation. If radiologic examination of the true pelvis must be carried out despite pregnancy or is inadvertently done because pregnancy was not recognized, the radiation exposure of the embryo is so small in most cases because of modern dose-sparing equipment, that an interruption of pregnancy is not justified. A dose of less than 1 rad is, as a rule, justifiable, but it is less justifiable that alarmed, uninformed physicians instill a deep-seated fear of giving brith to a freak in a woman through false information. (orig.) [de

  14. Environmental radiation and exposure to radiation

    International Nuclear Information System (INIS)

    1981-02-01

    Compared to 1977 the exposure to radiation of the population of the Federal Republic of Germany from both natural and artificial radiation sources has not greatly charged. The amin part of exposure to natural radiation is caused by environmental radiation and by the absorption of naturally radioactive substances into the body. Artificial exposure to radiation of the population is essentially caused by the use of ionizing rays and radioactive substances in medicine. When radioactive materials are released from nuclear facilities the exposure to radiation of the population is only very slightly increased. The real exposure to radiation of individual people can even in the worst affected places, have been at most fractions of a millirem. The exposure to radiation in the worst afected places in the area of a hard-coal power station is higher than that coming from a nuclear power station of the same capacity. The summation of all contributions to the exposure of radiation by nuclear facilities to the population led in 1978 in the Federal Republic of Germany to a genetically significant dose of clearly less than 1 millerem per year. The medium-ranged exposure to radiation by external radiation effects through professional work was in 1978 at 80 millirems. No difference to 1977. The contribution of radionuclide from the fallout coming from nuclear-weapon tests and which has been deposited in the soil, to the whole-body dose for 1978 applies the same as the genetically significant dose of the population with less than 1 millirem. (orig./HP) [de

  15. Bioeffects and health risks of low-level exposures to radiofrequency and microwave fields-scientific facts and public concerns

    International Nuclear Information System (INIS)

    Szmigielski, Stanislaw

    2001-01-01

    Radiofrequency (RF) and microwave (MW) radiations, parts of the electromagnetic spectrum at wave frequencies of 0.1 - 300 MHz and 300 MHz - 300 GHz, respectively, can penetrate human tissues and exert various bioeffects at relatively low field power densities. Exposure of the general public to RF/MW radiation in the environment is generally below intensities which are considered as responsible for evoking such bioeffects. Use of mobile phones (MP) considerably increased local exposure to 900 or 1800 MHz MWs and raised concerns of the risk of brain tumors and other neoplasms of the head. At present the experimental and epidemiological bulk of evidence is too limited for valid assessment of the risks. Health consequences of long-term use of MPs are not known in detail, but available data indicate that development of non-specific health symptoms is possible, at least in 'MW-hypersensitive' subjects. In contrast to cellular terminals, which emit locally relatively high intensity MW fields, transmitting antennas and base stations contribute to MW environmental contaminations only with a small portion of the energy and do not pose established health risks. Two available epidemiological studies of brain cancer morbidity in MP users did not confirm an increased risk for all types of neoplasms, but unexplained excesses of particular types and/or locations of the tumors has been reported. Experimental investigations revealed the possibility of epigenetic activity of certain MW exposures (frequently limited to particular frequencies and/or modulations of the carrier wave), but there exists no satisfactory support from epidemiological studies for the increased cancer risk in MW-exposed subjects. However, there exist single epidemiological studies which indicate increased mortality of certain types of neoplasms in workers exposed to microwave radiation. As an example, the multiyear study of cancer morbidity in Polish military personnel exposed to 2 - 10 W/m2 will be presented

  16. DOE 2012 occupational radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2013-10-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2012 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past 5-year period, the occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site.

  17. DOE 2011 occupational radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2012-12-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2011 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past five years.

  18. Cardiovascular diseases induced by low level ionizing radiation. Current status and proposal of future directions of the biological studies

    International Nuclear Information System (INIS)

    Iwasaki, Toshiyasu; Nomura, Takaharu; Ishii, Keiichiro

    2013-01-01

    In the publication on tissue reactions of the International Commission on Radiological Protection (ICRP), the risk of cardiovascular diseases (CVD) was calculated based on linear non-threshold model, without taking account of dose-rate effect. To evaluate the validity of this estimation, we analyzed recent epidemiological and biological findings on CVD at low dose or low dose-rate. Though epidemiological data suggested that radiation would have a causal association with CVD by inducing atherosclerosis, it was limited by heterogeneity among studies, and the contribution of other pathways was also suggested. As biological mechanisms, inflammation is considered as the critical factor of radiation induced CVD. However, the inflammatory responses at low dose were inconsistent among studies, and there were few data at low dose-rate. Furthermore, because those responses were transient, it was very difficult to link them to CVD with long latency. We proposed a concept for the analysis of these long latency diseases by focusing the premonitory symptoms of CVD which could be affected by radiation. As the premonitory symptoms recruitment of white blood cells to inflamed blood vessels and/or tissues would have the highest priority to investigate. To elucidate the dose-rate effect and reflect the results on the radiological protection, it would be important to examine the premonitory symptoms after long term exposure mimicking the actual situation, such as chronic exposure or fractionated exposure of very small dose. (author)

  19. Bases for establishing radiation exposure limits

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1977-01-01

    It is an essential requirement of good radiation protection that all unnecessary exposure of people should be avoided and that any necessary exposure, whether of workers or of members of the general public, should be minimized. It is, however, an additional requirement that such necessary exposures should not exceed certain stated limits. These principles are based on the possibility that even the smallest exposures may involve some risk of harm, that any risk of harm should be justifiable by the circumstances necessitating it, and that risk should always be limited to an appropriately low level. The bases for establishing exposure limits must therefore involve an assessment of the risk involved in any form of radiation exposure, and an opinion as to the degree of safety that should be ensured in circumstances which necessitate any occupational or public exposure to radiation. There is increasing quantitative evidence on the frequency on which harm, and particularly the induction of malignancies, may be caused in people exposed to radiation at high doses; and somewhat clearer bases than previously for inferring the possible frequencies at low doses. It is therefore easier to assess the degree of safety ensured by restricting radiation exposure to particular levels. It is clear also that a comparable degree of safety should be ensured whether the radiation exposure involves the whole body more of less uniformly, or individual tissues or organs selectively. The ''weighting'' factors appropriate to irradiation of particular tissues from internal emitters can thus be defined in terms of their likely individual contributions to the harm of whole-body irradiation. In this way the limits for different modes of exposure by external or internal radiation can be related so as to ensure that protection should be equally effective for different distributions of absorbed dose in the body. In particular, the over-simplified concept of a single critical organ determining the

  20. Environmental radioactivity and radiation exposure

    International Nuclear Information System (INIS)

    1980-01-01

    In 1977 population exposure in the Federal Republic of Germany has not changed as compared to the previous years. The main share of the total exposure, nearly two thirds, is attributed to natural radioactive substances and cosmic radiation. The largest part (around 85%) of the artificial radiation exposure is caused by X-ray diagnostics. In comparison to this, radiation exposure from application of ionizing radiation in medical therapy, use of radioactive material in research and technology, or from nuclear facilities is small. As in the years before, population exposure caused by nuclear power plants and other nuclear facilities is distinctly less than 1% of the natural radiation exposure. This is also true for the average radiation exposure within a radius of 3 km around nuclear facilities. On the whole, the report makes clear that the total amount of artificial population exposure will substantially decrease only if one succeeds in reducing the high contribution to the radiation exposure caused by medical measures. (orig.) [de

  1. Radiation exposure from incorporated isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Beleznay, F [Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics

    1985-01-01

    Recommendations for the limitation of the burden of the human body from radiation exposure were developed to avoid direct radiation health damage such that the occurrence of stochastic damage can be held below a resonable risk level. The recommendations, published under ICRP 26 and ICRP 30, contain several guidelines and concepts which are discussed here. They include the primary internal dose exposure limits, secondary and implied limits for the monitoring of internal radiation exposure (Annual Limit of Intake, Derived Air Concentrations). Methods are presented for inspection and monitoring of internal exposure in medical laboratories, inspection of incorporation of sup(131)I and sup(99m)Tc.

  2. Non-linearity of dose-effect relationship at low level exposure on the example of cytogenetic effects in plant cells

    International Nuclear Information System (INIS)

    Oudalova, A.A.; Geras'kin, S.A.; Dikarev, V.G.; Dikareva, N.S.; Chernonog, E.V.

    2007-01-01

    Complete text of publication follows. There has been an increasing concern in the current scientific society and among the public about the need to protect the environment in order to maintain the ecosystem sustainability and future well-being of man. The linear non-threshold (LNT) hypothesis as the most officially acknowledged concept of biological effect of radiation fails to explain many facts on effects at low level exposures (LLE) accumulated lately. Available information on the dose-effect relationship at low doses is scarce and incomplete for non-human species despite the fact that, under conditions of increased radiation exposure, some biota species occur at a risk of higher impact than humans because of differences in ecological niches occupied. Dose-effect relationships for cytogenetic damage in the range of LLE are studied in a series os experiments with plant (Hordeum vulgare L.) meristem cells. Dose-effect dependences obtained show an obvious non-linear behavior in the LLE region. A piecewise linear model (PLM) for dose-cytogenetic effect relationship that considers an existence of dose-independent part at LLE ('plateau') is developed and specified on the data obtained. An advantage of the PLM over linear model in approximating the frequency of cytogenetic disturbances is demonstrated. From an empirical probability distribution analysis, it is shown that the increase in cytogenetic damage level is tightly connected with changes in a process of absorbed energy distribution between target volumes in terms of fraction of cells experienced a radiation hit event. An appropriateness of the LNT hypothesis to the description of cytogenetic disturbances yield in plant meristem cells in the LLE region is discussed. The results support a conclusion about indirect mechanism of mutagenesis induced by low doses. New data obtained concern a perception of fundamental mechanisms governing cell response to LLE. These findings are of general biological interest, since

  3. DOE 2010 occupational radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2011-11-01

    The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE.* The DOE 2010 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with DOE Part 835 dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. The occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site over the past 5 years.

  4. The sources of radiation exposure

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1992-01-01

    Radiation protection of workers and of members of the public requires an assessment of the various sources of exposure, their variations in time or under specific conditions or circumstances, and the possibilities for control or limitation. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has evaluated the various components of natural and man-made sources in some detail. Natural exposures form the largest component of radiation exposure of man. Variability in exposures depends on elevation, the concentrations of radionuclides in soil, food and water, the composition of building materials and the susceptibility of indoor spaces to radon build-up. Man-made sources have included exposures to fallout from atmospheric nuclear testing and discharged from nuclear fuel cycle installations in routine operations or in accidents. The other main source of radiation exposures of individuals is in medical diagnostic examinations and therapeutic treatments. (author)

  5. Occupational exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Snihs, J.O.

    1985-01-01

    An overview of occupational exposure is presented. Concepts and quantities used for radiation protection are explained as well as the ICRP system of dose limitation. The risks correlated to the limits are discussed. However, the actual exposure are often much lower than the limits and the average risk in radiation work is comparable with the average risk in other safe occupations. Actual exposures in various occupations are presented and discussed. (author)

  6. Calculating radiation exposure and dose

    International Nuclear Information System (INIS)

    Hondros, J.

    1987-01-01

    This paper discusses the methods and procedures used to calculate the radiation exposures and radiation doses to designated employees of the Olympic Dam Project. Each of the three major exposure pathways are examined. These are: gamma irradiation, radon daughter inhalation and radioactive dust inhalation. A further section presents ICRP methodology for combining individual pathway exposures to give a total dose figure. Computer programs used for calculations and data storage are also presented briefly

  7. Worldwide exposures to ionizing radiation

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1993-01-01

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

  8. 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)

  9. Lactobacillus rhamnosus ATCC 7469 exopolysaccharides synergizes with low level ionizing radiation to modulate signaling molecular targets in colorectal carcinogenesis in rats.

    Science.gov (United States)

    Zahran, Walid E; Elsonbaty, Sawsan M; Moawed, Fatma S M

    2017-08-01

    Combination therapy that targets cellular signaling pathway represents an alternative therapy for the treatment of colon cancer (CRC). The present study was therefore aimed to investigate the probable interaction of Lactobacillus rhamnosus ATCC 7469 exopolysaccharides (EPS) with low level ionizing γ radiation (γ-R) exposure against dimethylhydrazine (DMH)- induced colorectal carcinogenesis in rats. Colon cancer was induced with 20mg DMH/kg BW. Rats received daily by gastric gavage 100mg EPS/Kg BW concomitant with 1Gy γ-R over two months. Colonic oxidative and inflammatory stresses were assessed. The change in the expression of p-p38 MAPK, p-STAT3, β-catenin, NF-kB, COX-2 and iNOS was evaluated by western blotting and q-PCR. It was found that DMH treatment significantly induced colon oxidative injury accompanied by inflammatory disturbance along with increased protein expression of the targeted signaling factors p-p38 MAPK, p-STAT3 and β-catenin. The mRNA gene expression of NF-kB, COX-2 and iNOS was significantly higher in DMH-treated animals. It's worthy to note that colon tissues with DMH treatment showed significant dysplasia and anaplasia of the glandular mucosal lining epithelium with loses of goblet cells formation, pleomorphism in the cells and hyperchromachia in nuclei. Interestingly, EPS treatment with γ-R exposure showed statistically significant amelioration of the oxidative and inflammatory biomarkers with modulated signaling molecular factors accompanied by improved histological structure against DMH-induced CRC. In conclusion, our findings showed that Lactobacillus rhamnosus ATCC 7469 EPS with low level γ-R in synergistic interaction are efficacious control against CRC progression throughout the modulation of key signaling growth factors associated with inflammation via antioxidant mediated anti-inflammatory and anti-proliferative activities. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  10. Effects after prenatal radiation exposures

    International Nuclear Information System (INIS)

    Streffer, C.

    2001-01-01

    The mammalian organism is highly radiosensitive during all prenatal developmental periods. For most effects a dose relationship with a threshold is observed. These threshold doses are generally above the exposures from medical diagnostic procedures. The quality and extent of radiation effects are very much dependent on the developmental stage during which an exposure takes place and on the radiation dose. An exposure during the preimplantation period will cause lethality. Malformations are usually induced after exposures during the major organogenesis. Growth retardation is also possible during the late organogenesis and foetal periods. The lower limits of threshold doses for these effects are in the range of 100 mGy. A radiation exposure during the early foetal period can lead to severe mental retardation and impairment of intelligence. There are very serious effects with radiation doses above 0.3 Gy. Carcinogenesis can apparently occur after radiation exposures during the total prenatal development period. The radiation risk factor up to now has not been clear, but it seems that it is in the range of risk factors for cancer that are observed after exposures during childhood. For radiation doses that are used in radiological diagnostics the risk is zero or very low. A termination of pregnancy after doses below 100 mGy should not be considered. (author)

  11. Low Level Exposure to GB Vapor in Air: Diagnosis/Dosimetry, Lowest Observable Effect Levels, Performance-Incapacitation, and Possible Delayed Effects

    National Research Council Canada - National Science Library

    Helden, Herman

    2002-01-01

    .... 2001 under experimental conditions similar to those in Nov. 2000 when they were first 5 h exposed to air followed by 5 h exposure to low levels of GB vapor in air in a concentration range of 7.5 - 150 micron/m3...

  12. Evaluation of environmental radiation exposure

    International Nuclear Information System (INIS)

    Imai, Kazuhiko

    1974-01-01

    The environmental radiation exposure due to radioactive rare gases is most important both at the time of reactor accidents and also in the long-term normal operation of reactor plants. The exposure dose is usually calculated by means of computers. The procedure of the calculation on environmental exposure dose is divided in several consecutive steps. The calculational formulae frequently used and those proposed recently are given with the explanation on released radionuclides, release to the atmosphere, concentration in the atmosphere, β-ray exposure, γ-ray exposure, and calculation of long-term exposure dose. (Mori, K.)

  13. 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)

  14. Assessment of capabilities and research needs in the area of health effects of low-level ionizing radiation. A joint report to the Congress

    International Nuclear Information System (INIS)

    1979-08-01

    The report summarizes the capabilities, research needs and on-going projects of the Environmental Protection Agency and the Nuclear Regulatory Commission related to the health effects of low-level ionizing radiation. The statutory authorities of both EPA and NRC related to radiation protection and radiation research are also briefly described. An introductory general section describes current efforts to improve Federal radiation research and general methods used by both agencies for radiation dose assessment and the estimation of the potential health effects of low-level ionizing radiation. Separate sections describe the respective authorities, needs, capabilities, and current research programs of the two agencies. The report was prepared to fulfill a requirement by the US Congress which is contained in Section 5(c) of Public Law 95-601

  15. Control of external radiation exposure

    International Nuclear Information System (INIS)

    Abd Nasir Ibrahim; Azali Muhammad; Ab Razak Hamzah; Abd Aziz Mohamed; Mohammad Pauzi Ismail

    2004-01-01

    The following subjects are discussed - Control of external radiation exposure: working time, working distance, shielding: Total Linear Attenuation Coefficient, Half-Value Layer (HVL), Tenth-Value Layer (TVL); Build-up Factor

  16. Intentional exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Kivisakk, E.

    1987-01-01

    Exposure to UV radiation can cause a number of detrimental effects to human health. Some of these are particularly grave, as for instance the induction of skin cancer. Nevertheless, intentional exposure to UV radiation is commonly practiced for many purposes, ranging from medical treatment to merely a simple form of pastime. From the radiation point of view, the risks associated with exposure to UV radiation in any particular application should be carefully considered, and only accepted if they are obviously compensated by the benefits of the irradiation. This is not always the case today, to some extent due to shortage of information about the effect of UV radiation - especially on a long term basis

  17. Radiation exposure and infant cancer

    Energy Technology Data Exchange (ETDEWEB)

    Watari, T [Tokyo Univ. (Japan). Faculty of Medicine

    1974-12-01

    Medical exposures accompanied by an increase in radiation use in the field of pediatrics were described. Basic ideas and countermeasures to radiation injuries were outlined. In order to decrease the medical exposure, it is necessary for the doctor, x-ray technician and manufacturer to work together. The mechanism and characteristics of radio carcinogenesis were also mentioned. Particularly, the following two points were described: 1) How many years does it take before carcinogenesis appears as a result of radiation exposure in infancy 2) How and when does the effect of fetus exposure appear. Radiosensitivity in infants and fetuses is greater than that of an adult. The occurrence of leukemia caused by prenatal exposure was reviewed. The relation between irradiation for therapy and morbidity of thyroid cancer was mentioned. Finally, precautions necessary for infants, pregnant women and nursing mothers when using radioisotopes were mentioned.

  18. 8-Hydroxy-2'-deoxyguanosine (8-OH-dG): A biomarker of oxidative damage in yellow bullheads chronically exposed to low-level radiation

    International Nuclear Information System (INIS)

    McCreedy, C.D.; Glickman, L.T.

    1995-01-01

    8-hydroxy-2'-deoxyguanosine (8-OH-dG), an oxidation product of the nucleotide deoxyguanosine (dG) was used as a biomarker to assess oxidative damage in brain and gill tissues of yellow bullhead catfish (Ameiurus natalis; n = 18) inhabiting an abandoned reactor reservoir contaminated with low levels of d137 Cs (Pond B, Savannah River Site, SC). DNA was isolated by chloroform-isoamyl extraction, enzymatically digested with Nuclease P1/Calf Intestinal Phosphatase, and analyzed by HPLC with electrochemical detection.Length, weight, age, condition and muscle 137 Cs activity of each fish were also determined. Concentrations of 8-OH-dG were greater in brain than in gill tissues. 8-OH-dG in gill tissues decreased as condition of fish increased, but as age increased, the effect of condition declined. Brain 8-OH-dG concentration was not related to age or condition of fish, but was greater in females and the interaction between gender and 137 Cs was significant. Brain 8-OH-dG was positively associated with muscle 137 Cs concentration among females, but was unrelated to 137 Cs concentration in males. At lower 137 Cs concentrations, females tended to have fewer oxidative DNA adducts in brian than did males. Deposition of somatic lipids into eggs may provide females some anti-oxidant benefit by diminishing the contribution of lipid peroxidation to DNA damage. 8-OH-dG is a sensitive biomarker of low-level radiation exposure, however, its application in fish requires consideration of factors such as gender, age, body-condition, and the tissue type sampled

  19. Relationship between long-term exposure to low-level arsenic in drinking water and the prevalence of abnormal blood pressure.

    Science.gov (United States)

    Zhang, Chuanwu; Mao, Guangyun; He, Suxia; Yang, Zuopeng; Yang, Wei; Zhang, Xiaojing; Qiu, Wenting; Ta, Na; Cao, Li; Yang, Hui; Guo, Xiaojuan

    2013-11-15

    Arsenic increases the risk and incidence of cardiovascular disease. To explore the impact of long-term exposure to low-level arsenic in drinking water on blood pressure including pulse pressure (PP) and mean arterial blood pressure (MAP), a cross-sectional study was conducted in 2010 in which the blood pressure of 405 villagers was measured, who had been drinking water with an inorganic arsenic content 30-50 years of arsenic exposure and a 2.95-fold (95%CI: 1.31-6.67) increase in the group with >50 years exposure. Furthermore, the odds ratio for prevalence of abnormal PP and MAP were 1.06 (95%CI: 0.24-4.66) and 0.87 (95%CI: 0.36-2.14) in the group with >30-50 years of exposure, and were 2.46 (95%CI: 0.87-6.97) and 3.75 (95%CI: 1.61-8.71) for the group with >50 years exposure, compared to the group with arsenic exposure ≤ 30 years respectively. Significant trends for Hypertension (p<0.0001), PP (p<0.0001) and MAP (p=0.0016) were found. The prevalence of hypertension and abnormal PP as well as MAP is marked among a low-level arsenic exposure population, and significantly increases with the duration of arsenic exposure. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Malignant mesothelioma following radiation exposure

    International Nuclear Information System (INIS)

    Antman, K.H.; Corson, J.M.; Li, F.P.; Greenberger, J.; Sytkowski, A.; Henson, D.E.; Weinstein, L.

    1983-01-01

    Mesothelioma developed in proximity to the field of therapeutic radiation administered 10-31 years previously in four patients. In three, mesothelioma arose within the site of prior therapeutic radiation for another cancer. Mesothelioma in the fourth patient developed adjacent to the site of cosmetic radiation to a thyroidectomy scar. None of these four patients recalled an asbestos exposure or had evidence of asbestosis on chest roentgenogram. Lung tissue in one patient was negative for ferruginous bodies, a finding considered to indicate no significant asbestos exposure. Five other patients with radiation-associated mesothelioma have been reported previously, suggesting that radiation is an uncommon cause of human mesothelioma. Problems in the diagnosis of radiation-associated mesotheliomas are considered

  1. [Effects of radiation exposure on human body].

    Science.gov (United States)

    Kamiya, Kenji; Sasatani, Megumi

    2012-03-01

    There are two types of radiation health effect; acute disorder and late on-set disorder. Acute disorder is a deterministic effect that the symptoms appear by exposure above a threshold. Tissues and cells that compose the human body have different radiation sensitivity respectively, and the symptoms appear in order, from highly radiosensitive tissues. The clinical symptoms of acute disorder begin with a decrease in lymphocytes, and then the symptoms appear such as alopecia, skin erythema, hematopoietic damage, gastrointestinal damage, central nervous system damage with increasing radiation dose. Regarding the late on-set disorder, a predominant health effect is the cancer among the symptoms of such as cancer, non-cancer disease and genetic effect. Cancer and genetic effect are recognized as stochastic effects without the threshold. When radiation dose is equal to or more than 100 mSv, it is observed that the cancer risk by radiation exposure increases linearly with an increase in dose. On the other hand, the risk of developing cancer through low-dose radiation exposure, less 100 mSv, has not yet been clarified scientifically. Although uncertainty still remains regarding low level risk estimation, ICRP propound LNT model and conduct radiation protection in accordance with LNT model in the low-dose and low-dose rate radiation from a position of radiation protection. Meanwhile, the mechanism of radiation damage has been gradually clarified. The initial event of radiation-induced diseases is thought to be the damage to genome such as radiation-induced DNA double-strand breaks. Recently, it is clarified that our cells could recognize genome damage and induce the diverse cell response to maintain genome integrity. This phenomenon is called DNA damage response which induces the cell cycle arrest, DNA repair, apoptosis, cell senescence and so on. These responses act in the direction to maintain genome integrity against genome damage, however, the death of large number of

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

    Science.gov (United States)

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

    2013-03-18

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

  3. Radiation Exposure from Medical Exams and Procedures

    Science.gov (United States)

    Fact Sheet Adopted: January 2010 Health Physics Society Specialists in Radiation Safety Radiation Exposure from Medical Exams and Procedures Ionizing radiation is used daily in hospitals and clinics ...

  4. Radiation Exposure - Multiple Languages

    Science.gov (United States)

    ... Rays) - 繁體中文 (Chinese, Traditional (Cantonese dialect)) PDF California Dental Association Nuclear or Radiation Emergencies - 繁體中文 (Chinese, Traditional (Cantonese dialect)) Bilingual PDF ...

  5. Radiation protection: occupational exposure

    International Nuclear Information System (INIS)

    Shah, G.A.

    1990-01-01

    The basis of the occupational exposure limit of 50 mSv recommended by the ICRP is questioned. New dosimetry at Hiroshima and Nagasaki, the fact that the dose-response curve may be non-linear and that the relative risk model may be applicable, are some of the arguments advanced to support a reduction in the occupational exposure dose limits. 5 refs., 2 tabs., 3 figs

  6. 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 (

  7. DOE 2013 occupational radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    none,

    2014-11-01

    The Office of Analysis within the U.S. Department of Energy (DOE) Office of Environment, Health, Safety and Security (EHSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2013 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past five-year period, the occupational radiation exposure information has been analyzed in terms of aggregate data, dose to individuals, and dose by site.

  8. Radiation Exposure of Passengers to Cosmic Radiation

    International Nuclear Information System (INIS)

    Salah El-Din, T.; Gomaa, M.A.; Sallah, N.

    2010-01-01

    The main aim of the present study is to review exposure of Egyptian passengers and occupational workers to cosmic radiation during their work. Computed effective dose of passengers by computer code CARI-6 using during either short route, medium route or long route as well as recommended allowed number of flights per year

  9. Regulation of gene expression by low levels of ultraviolet-B radiation in Pisum sativum: Isolation of novel genes by suppression subtractive hybridisation

    International Nuclear Information System (INIS)

    Sävenstrand, H.; Brosché, M.; Strid, A.

    2002-01-01

    Suppression subtractive hybridisation was used to isolate genes differentially regulated by low levels (UV-B BE,300 0.13 W m -2 ) of ultraviolet-B radiation (UV-B; 290–320 nm) in Pisum sativum. Six genes were regulated, two of which were novel. The mRNA levels for these two (PsTSDC and PsUOS1) were increased and depressed by UV-B treatment, respectively. Domains in the PsTSDC translation product was similar to TIR (Toll-Interleukin-1 receptor-similar) domains and a NB-ARC domain (nucleotide-binding domain in APAF-1, R gene products and CED-4). The PsUOS1 translation product was similar to an open reading frame in Arabidopsis. Genes encoding embryo-abundant protein (PsEMB) and S-adenosyl-l-methionine synthase (PsSAMS) were induced by UV-B, whereas the transcript levels for genes encoding sucrose transport protein (PsSUT) or ribulose-5-phosphate 3-epimerase (PsR5P3E) were decreased. These regulation patterns are novel, and the PsEMB and PsR5P3E sequences are reported for the first time. The stress-specificity of regulation of these genes were tested by ozone fumigation (100 ppb O 3 ). Qualitatively, the similarity of expression after both UV-B and ozone exposure suggests that, for these genes, similar stress-response pathways are in action. (author)

  10. Very low level radioactive material

    International Nuclear Information System (INIS)

    Schaller, K.H.; Linsley, G.; Elert, M.

    1993-01-01

    Man's environment contains naturally occurring radionuclides and doses from exposures to these radionuclides mostly cannot be avoided. Consequently, almost everything may be considered as very low level radioactive material. In practical terms, management and the selection of different routes for low level material is confined to material which was subject to industrial processing or which is under a system of radiological control. Natural radionuclides with concentrations reaching reporting or notification levels will be discussed below; nevertheless, the main body of this paper will be devoted to material, mainly of artificial origin, which is in the system involving notification, registration and licensing of practices and sources. It includes material managed in the nuclear sector and sources containing artificially produced radionuclides used in hospitals, and in industry. Radioactive materials emit ionising radiations which are harmful to man and his environment. National and international regulations provide the frame for the system of radiation protection. Nevertheless, concentrations, quantities or types of radionuclide may be such, that the material presents a very low hazard, and may therefore be removed from regulatory control, as it would be a waste of time and effort to continue supervision. These materials are said to be exempted from regulatory control. Material exempted in a particular country is no longer distinguishable from ''ordinary'' material and may be moved from country to country. Unfortunately, criteria for exempting radioactive materials differ strongly between countries and free trade. Therefore there is a necessity for an international approach to be developed for exemption levels

  11. Levels of oxylipins, endocannabinoids and related lipids in plasma before and after low-level exposure to acrolein in healthy individuals and individuals with chemical intolerance.

    Science.gov (United States)

    Claeson, Anna-Sara; Gouveia-Figueira, Sandra; Häggström, Jenny; Fowler, Christopher J; Nording, Malin L

    2017-06-01

    Oxylipins and endocannabinoids play important biological roles, including effects upon inflammation. It is not known whether the circulating levels of these lipids are affected by inhalation of the environmental pollutant acrolein. In the present study, we have investigated the consequences of low-level exposure to acrolein on oxylipin, endocannabinoid and related lipid levels in the plasma of healthy individuals and individuals with chemical intolerance (CI), an affliction with a suggested inflammatory origin. Participants were exposed twice (60min) to heptane and a mixture of heptane and acrolein. Blood samples were collected before exposure, after and 24h post-exposure. There were no overt effects of acrolein exposure on the oxylipin lipidome or endocannibinoids detectable in the bloodstream at the time points investigated. No relationship between basal levels or levels after exposure to acrolein and CI could be identified. This implicates a minor role of inflammatory mediators on the systemic level in CI. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Environmental radioactivity and radiation exposure

    International Nuclear Information System (INIS)

    1976-01-01

    The environmental radioactivity in the Federal Republic of Germany was almost as high in 1976 as in 1975. It only increased temporarily in autumn 1976 as a result of the above-ground nuclear weapons test of the People's Republic of China on September 29th 1976 and then returned to its previous level. The radioactivity in food had a slight decreasing trend in 1976, apart from a temporary increase in the radioactivity in milk also caused by the nuclear weapons test mentioned. The population exposure remains basically unchanged in 1976 compared with 1975. The artificial radiation exposure is about half as high as the natural radiation exposure to which man has always been exposed. The former is based to 83% on using X-rays in medicine, particularly for X-ray diagnostic purposes. The population exposure due to nuclear power plants and other nuclear plants is still well below 1% of the natural radiation exposure although in 1976 three new nuclear power plants were put into operation. This is also true for the average radiation exposure within an area of 3 km around the nuclear plant. (orig.) [de

  13. Neurophysiologic and Neuropathologic Effects in Monkeys of Low Level Exposures to Sarin, Pyridostigmine, Pesticides and Botulinum Toxoid

    National Research Council Canada - National Science Library

    Olson, Carl

    1998-01-01

    .... Pilot studies are being performed to select doses of pyridostigmine bromide (PB), chlorpyrifos (CPF), and sarin (GE) to be used in two-week exposures with a 9-month post-dosing evaluation period...

  14. Size-dependent effects of low level cadmium and zinc exposure on the metabolome of the Asian clam, Corbicula fluminea

    Energy Technology Data Exchange (ETDEWEB)

    Spann, Nicole, E-mail: nicole.spann@web.de [Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ (United Kingdom); Aldridge, David C., E-mail: da113@cam.ac.uk [Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ (United Kingdom); Griffin, Julian L., E-mail: jlg40@mole.bio.cam.ac.uk [Sanger Building, Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom); Jones, Oliver A.H., E-mail: o.jones@gmail.com [Sanger Building, Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA (United Kingdom)

    2011-10-15

    Highlights: Small and large Corbicula fluminea were exposed to cadmium and zinc spiked sediment. Metabolomic changes in the freshwater clams were determined by NMR and GC-MS. Metabolic perturbations were related to amino acid and energy related metabolism. Small and large clams were differentiated by their metabolic composition. Size classes showed opposite responses to metal stress. - Abstract: The toxic effects of low level metal contamination in sediments are currently poorly understood. We exposed different sized Asian clams, Corbicula fluminea, to sediment spiked with environmentally relevant concentrations of either zinc, cadmium or a zinc-cadmium mixture for one week. This freshwater bivalve is well suited for sediment toxicity tests as it lives partly buried in the sediment and utilises sediment particles as a food resource. After one week, the whole tissue composition of low molecular weight metabolites was analysed by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography-mass spectrometry (GC-MS). The condition index (ratio of tissue dry weight to volume inside the shell valves) was also measured. Small and large clams were clearly differentiated by their metabolic composition and the two size classes showed opposite responses to the mixture spiked sediment. No effects of zinc alone on the metabolome were found and cadmium only influenced the smaller size class. The main perturbations were seen in amino acid and energy metabolism, with small clams using amino acids as an energy resource and larger clams primarily drawing on their larger storage reserves of carbohydrates. Our study demonstrates that metabolomics is a useful technique to test for low level toxicity which does not manifest in mortality or condition index changes. The differing effects between the two size classes stress that it is important to consider age/size when conducting metabolomic and ecotoxicology assessments, since testing for the effects on only one size class makes

  15. Size-dependent effects of low level cadmium and zinc exposure on the metabolome of the Asian clam, Corbicula fluminea

    International Nuclear Information System (INIS)

    Spann, Nicole; Aldridge, David C.; Griffin, Julian L.; Jones, Oliver A.H.

    2011-01-01

    Highlights: Small and large Corbicula fluminea were exposed to cadmium and zinc spiked sediment. Metabolomic changes in the freshwater clams were determined by NMR and GC–MS. Metabolic perturbations were related to amino acid and energy related metabolism. Small and large clams were differentiated by their metabolic composition. Size classes showed opposite responses to metal stress. - Abstract: The toxic effects of low level metal contamination in sediments are currently poorly understood. We exposed different sized Asian clams, Corbicula fluminea, to sediment spiked with environmentally relevant concentrations of either zinc, cadmium or a zinc–cadmium mixture for one week. This freshwater bivalve is well suited for sediment toxicity tests as it lives partly buried in the sediment and utilises sediment particles as a food resource. After one week, the whole tissue composition of low molecular weight metabolites was analysed by nuclear magnetic resonance spectroscopy (NMR) and gas chromatography–mass spectrometry (GC–MS). The condition index (ratio of tissue dry weight to volume inside the shell valves) was also measured. Small and large clams were clearly differentiated by their metabolic composition and the two size classes showed opposite responses to the mixture spiked sediment. No effects of zinc alone on the metabolome were found and cadmium only influenced the smaller size class. The main perturbations were seen in amino acid and energy metabolism, with small clams using amino acids as an energy resource and larger clams primarily drawing on their larger storage reserves of carbohydrates. Our study demonstrates that metabolomics is a useful technique to test for low level toxicity which does not manifest in mortality or condition index changes. The differing effects between the two size classes stress that it is important to consider age/size when conducting metabolomic and ecotoxicology assessments, since testing for the effects on only one size

  16. Radiation exposure in manned spaceflight

    Energy Technology Data Exchange (ETDEWEB)

    Buecker, H. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V., Koeln (Germany)); Horneck, G. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V., Koeln (Germany)); Facius, R. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V., Koeln (Germany)); Reitz, G. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V., Koeln (Germany))

    1993-08-01

    Space missions exposure humans to a radiation environment of a particulate composition and intensity not encountered within our biosphere. The natural radiation environment encountered in Earth orbit is a complex mixture of charged particles of galactic and solar origin and of those trapped by the geomagnetic field. In addition, secondaries are produced by interaction of cosmic ray primaries with the spacecraft shielding material. Among this large variety of radiation components in space, it is likely that the heavy ions are the significant species as far as radiobiological effects are concerned. In addition, a synergistic interaction of microgravity and radiation on living systems has been reported in some instances. Based on an admissible risk of 3% mortality due to cancers induced during a working career, radiation protection guidelines have been developed for this radiation environment. (orig.)

  17. The causes and consequences of human exposure to ionising radiation

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1991-01-01

    Few phenomena cause as much concern in developed countries as human exposure to artificial sources of radiation, and yet there are more potent threats to health: natural radiation is more pervasive and exposures more substantial; common practices such as smoking and drinking are more detrimental. Developing countries may be more anxious to establish radiological procedures than radiological protection. This paper gives the ranges of exposure to which people are subjected from natural and artificial sources which should help to put all doses in perspective. The relationship between dose and risk is established and used to show that exposures to radiation leak to low levels of risk. Finally, the new recommendations of ICRP for the control of radiation risk are presented. (Author)

  18. Psychiatric disorders after radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Kokai, Masahiro [Hyogo Coll. of Medicine, Nishinomiya (Japan); Soejima, Toshinori; Wang, Shangdong; Shinfuku, Naotaka

    2001-04-01

    This review focuses on the mental and psychological effects of medical radiation exposure, the nuclear accident at Three Mile Island, the Chernobyl disaster, atomic bomb explosions at Nagasaki and Hiroshima, and accidents at nuclear power plants and nuclear waste plants. Studies have shown that anxiety about the adverse effects of radiation in medicine (such as infertility, carcinogenicity, and genotoxicity) and fear for exposure has caused psychiatric disorders. Several studies on the mental health effects of the nuclear accident at Three Mile Island were conducted, and the results indicated that psychiatric distress persisted for a certain period of time, particularly in pregnant women and women who have children, even when no evidence of substantial of radiation exposure is seen clinically. The psychological consequences of the Chernobyl disaster have been investigated continuously, and various problems, e.g., acute stress reaction, neurosis, and psychosis, have been identified, although no physical damage due to the radiation or PTSD have been reported. By contrast, PTSD has been seen in survivors of the Nagasaki and Hiroshima nuclear explosions. A study in Ohio, (United States), which has a nuclear waste plant, investigated PTSD in people living near the plant and found that the symptom level was mild. In general, the most common symptoms among people with mental and psychological disorders due to radiation exposure are depression and anxiety, with many people having associated somatoform disorders, and some people complain of PTSD. Vague anxiety and fear of sequelae, regardless of the exposure dose, appears to cause such psychiatric disorders. Although it is rare for psychiatrists to see such cases of psychiatric disorders due to radiation exposure, their number may increase as psychiatric services become more widely available. (K.H.)

  19. Psychiatric disorders after radiation exposure

    International Nuclear Information System (INIS)

    Kokai, Masahiro; Soejima, Toshinori; Wang, Shangdong; Shinfuku, Naotaka

    2001-01-01

    This review focuses on the mental and psychological effects of medical radiation exposure, the nuclear accident at Three Mile Island, the Chernobyl disaster, atomic bomb explosions at Nagasaki and Hiroshima, and accidents at nuclear power plants and nuclear waste plants. Studies have shown that anxiety about the adverse effects of radiation in medicine (such as infertility, carcinogenicity, and genotoxicity) and fear for exposure has caused psychiatric disorders. Several studies on the mental health effects of the nuclear accident at Three Mile Island were conducted, and the results indicated that psychiatric distress persisted for a certain period of time, particularly in pregnant women and women who have children, even when no evidence of substantial of radiation exposure is seen clinically. The psychological consequences of the Chernobyl disaster have been investigated continuously, and various problems, e.g., acute stress reaction, neurosis, and psychosis, have been identified, although no physical damage due to the radiation or PTSD have been reported. By contrast, PTSD has been seen in survivors of the Nagasaki and Hiroshima nuclear explosions. A study in Ohio, (United States), which has a nuclear waste plant, investigated PTSD in people living near the plant and found that the symptom level was mild. In general, the most common symptoms among people with mental and psychological disorders due to radiation exposure are depression and anxiety, with many people having associated somatoform disorders, and some people complain of PTSD. Vague anxiety and fear of sequelae, regardless of the exposure dose, appears to cause such psychiatric disorders. Although it is rare for psychiatrists to see such cases of psychiatric disorders due to radiation exposure, their number may increase as psychiatric services become more widely available. (K.H.)

  20. Establishment of database for radiation exposure and safety assessment

    Energy Technology Data Exchange (ETDEWEB)

    Choi, G. S.; Kim, J. H. [Science Culture Research Institute, Seoul (Korea, Republic of)

    2005-12-15

    The nuclear electric energy in our country plays a major role for the national industrial development as well as for the secure living of the peoples. It is, however, considered as a socially dreadful elements because of the radiation materials exposed into the environment. In effect, the DB is intended to serve for the reference to the epidemical study upon the low-level radiation exposure involving the nuclear facilities, radio-isotope business enterprises, and the related workers at the radiation sites. In connection with the development of nuclear energy, the low-level radiation, associated with the radioisotope materials exposed into our environment out of nuclear facilities, is believed to possibly raise significant hazardous effects toward human persons. Therefor, it is necessary to take a positive counter measures by means of comprehensive quantitative estimates on its possibilities. In consequence, the low-level radiation effects do not bring about the immediate hazard cases, however, appear to possibly pose the lately caused diseases such as cancer cause, life reduction, and creation of mutation, etc. Therefore, it is intended to set up the social security with the secure safety, by conducting an advanced safety study on the low-level radiation.

  1. Establishment of database for radiation exposure and safety assessment

    International Nuclear Information System (INIS)

    Choi, G. S.; Kim, J. H.

    2005-12-01

    The nuclear electric energy in our country plays a major role for the national industrial development as well as for the secure living of the peoples. It is, however, considered as a socially dreadful elements because of the radiation materials exposed into the environment. In effect, the DB is intended to serve for the reference to the epidemical study upon the low-level radiation exposure involving the nuclear facilities, radio-isotope business enterprises, and the related workers at the radiation sites. In connection with the development of nuclear energy, the low-level radiation, associated with the radioisotope materials exposed into our environment out of nuclear facilities, is believed to possibly raise significant hazardous effects toward human persons. Therefor, it is necessary to take a positive counter measures by means of comprehensive quantitative estimates on its possibilities. In consequence, the low-level radiation effects do not bring about the immediate hazard cases, however, appear to possibly pose the lately caused diseases such as cancer cause, life reduction, and creation of mutation, etc. Therefore, it is intended to set up the social security with the secure safety, by conducting an advanced safety study on the low-level radiation

  2. Low-level Radioactive waste Management

    International Nuclear Information System (INIS)

    1991-01-01

    This meeting describes low-level radioactive waste management problems and contains 8 papers: 1 Low-level radioactive waste management: exemption concept and criteria used by international organizations. 2 Low-level radioactive waste management: french and foreign regulations 3 Low-level radioactive waste management in EDF nuclear power plants (FRANCE) 4 Low-level radioactive waste management in COGEMA (FRANCE) 5 Importance of low-level radioactive wastes in dismantling strategy in CEA (FRANCE) 6 Low-level radioactive waste management in hospitals 7 Low-level radioactive waste disposal: radiation protection laws 8 Methods of low-level radioactive materials measurements during reactor dismantling or nuclear facilities demolition (FRANCE)

  3. Occupational radiation exposure in Germany: many monitored persons = high exposure?

    International Nuclear Information System (INIS)

    Nitschke, J.

    1996-01-01

    Natural radiation affects the entire population in Germany, and most of Germany's inhabitants are exposed to medical radiation in their lifetime. Occupational radiation exposure, however, is a kind of exposure affecting only a limited and well-defined group of the population, and this radiation exposure has been recorded and monitored as precisely as technically possible ever since the radiation protection laws made occupational radiation exposure monitoring a mandatory obligation. Official personal dosimetry applying passive dosemeters in fact does not offer direct protection against the effects of ionizing radiation, as dosemeter read-out and dose calculation is a post-exposure process. But it nevertheless is a rewarding monitoring duty under radiation protection law, as is shown by the radiation exposure statistics accumulated over decades: in spite of the number of monitored persons having been increasing over the years, the total exposure did not, due to the corresponding improvements in occupational radiation protection. (orig.) [de

  4. Respiratory cancer risks associated with low-level nickel exposure: an integrated assessment based on animal, epidemiological, and mechanistic data.

    Science.gov (United States)

    Seilkop, Steven K; Oller, Adriana R

    2003-04-01

    Increased lung and nasal cancer risks have been reported in several cohorts of nickel refinery workers, but in more than 90% of the nickel-exposed workers that have been studied there is little, if any evidence of excess risk. This investigation utilizes human exposure measurements, animal data from cancer bioassays of three nickel compounds, and a mechanistic theory of nickel carcinogenesis to reconcile the disparities in lung cancer risk among nickel-exposed workers. Animal data and mechanistic theory suggest that the apparent absence of risk in workers with low nickel exposures is due to threshold-like responses in lung tumor incidence (oxidic nickel), tumor promotion (soluble nickel), and genetic damage (sulfidic nickel). When animal-based lung cancer dose-response functions for these compounds are extrapolated to humans, taking into account interspecies differences in deposition and clearance, differences in particle size distributions, and human work activity patterns, the predicted risks at occupational exposures are remarkably similar to those observed in nickel-exposed workers. This provides support for using the animal-based dose-response functions to estimate occupational exposure limits, which are found to be comparable to those in current use.

  5. Further studies on the genetic damage to bone marrow and other somatic effects following exposure to low level tritium

    International Nuclear Information System (INIS)

    Carsten, A.L.; Benz, R.D.; Commerford, S.L.; Hughes, W.; Ichimasa, Y.; Ikushima, T.; Tezuka, H.

    1984-01-01

    This paper emphasizes results obtained over the last 3 years, supplementing information presented at the first 3 H workshop. Sister chromtid exchange (SCE) measurements on mice maintained on 3.0 μCi/ml of tritiated water (HTO) or receiving an equal depth dose 137 Cs gamma exposure for 52 weeks have been completed. Small but significantly higher numbers of SCEs were found in animals receiving gamma exposures or maintained on HTO than in their controls. In animals removed from the HTO regimen after 27 weeks, the number of SCEs decreases with time, but did not return to control levels within the first 30 weeks. Comparative studies with the 137 Cs exposures indicate an RBE not significantly different than 1.0. Mice were also maintained on 7.5, 15.0 and 30.0 μCi/ml HTO for SCE studies. Results similar to those described for 3.0 μCi/ml were found. Maintaining animals on a 0.15% saccharin solution is the most effective of those tested for increasing the animals' water intake and for enhancing excretion of 3 H. The rate of disappearance of 3 H from animals maintained chronically on HTO indicated a two phase 3 H disappearance curve from hemoglobin. Single injections of HTO showed a brief delay in incorporation of 3 H followed by a disappearance paralleling the slower phase of the chronic exposure curve, and indicating a RBC lifetime of approximately 40 days. 21 references, 7 figures, 1 table

  6. Low-level environmental lead exposure in childhood and adult intellectual function: a follow-up study

    Directory of Open Access Journals (Sweden)

    Gregas Matthew

    2011-03-01

    Full Text Available Abstract Background Early life lead exposure might be a risk factor for neurocognitive impairment in adulthood. Objectives We sought to assess the relationship between early life environmental lead exposure and intellectual function in adulthood. We also attempted to identify which time period blood-lead concentrations are most predictive of adult outcome. Methods We recruited adults in the Boston area who had participated as newborns and young children in a prospective cohort study that examined the relationship between lead exposure and childhood intellectual function. IQ was measured using the Wechsler Abbreviated Scale of Intelligence (WASI. The association between lead concentrations and IQ scores was examined using linear regression. Results Forty-three adults participated in neuropsychological testing. Childhood blood-lead concentration (mean of the blood-lead concentrations at ages 4 and 10 years had the strongest relationship with Full-Scale IQ (β = -1.89 ± 0.70, p = 0.01. Full-scale IQ was also significantly related to blood-lead concentration at age 6 months (β = -1.66 ± 0.75, p = 0.03, 4 years (β = -0.90 ± 0.41, p = 0.03 and 10 years (β = -1.95 ± 0.80, p = 0.02. Adjusting for maternal IQ altered the significance of the regression coefficient. Conclusions Our study suggests that lead exposure in childhood predicts intellectual functioning in young adulthood. Our results also suggest that school-age lead exposure may represent a period of increased susceptibility. Given the small sample size, however, the potentially confounding effects of maternal IQ cannot be excluded and should be evaluated in a larger study.

  7. Low levels of vitamin D poorly responsive to daylight exposure in patients with therapy-resistant schizophrenia.

    Science.gov (United States)

    Bogers, Jan P.A.M.; Bostoen, Tijmen; Broekman, Theo G.

    2016-01-01

    Low vitamin D levels are associated with schizophrenia, but the possible association between vitamin D levels and illness severity or duration of exposure to daylight has barely been investigated. To compare vitamin D levels in therapy-refractory severely ill schizophrenia patients and members of staff. To investigate the influence of daylight exposure on vitamin D levels in patients. Vitamin D was measured in patients with therapy-resistant schizophrenia in April, after the winter, and in patients and staff members in June, after an exceptionally sunny spring. Vitamin D levels in April and June were compared in patients, and levels in June were compared in patients and staff. The influence of daylight was taken into account by comparing the time patients spent outdoors during the day with the recommended minimum time for adequate vitamin D synthesis, and by comparing time spent outdoors in patients and staff. Patients had high rates of vitamin D deficiency (79-90%) and lower levels of vitamin D than staff members (p vitamin D levels did not normalize, despite the considerably longer than recommended exposure of the skin to daylight (p vitamin D deficiency of therapy-resistant schizophrenia patients is pronounced and cannot be explained by differences in skin pigmentation or by an inactive, indoor lifestyle on the ward. Even theoretically sufficient exposure of the patients to daylight did not ameliorate the low vitamin D levels. While vitamin D deficiency probably plays a role in somatic health problems, it may also play a role in schizophrenia. Interestingly, exposure to daylight during an unusually sunny spring was not sufficient to correct the vitamin D deficiency seen in the patients. This emphasizes the need to measure and correct vitamin D levels in these patients.

  8. Vodnyi. A long-term, low-level radiation exposure field site in Russia

    International Nuclear Information System (INIS)

    Taskaev, A.I.; Guryev, D.V.

    2004-01-01

    The Vodnyi site in the Komi Republic of Russia represents a unique radioecological field site. The history of industrial operations associated with radioactivity here spans the period 1931 to 1956. Initial operations focused on the extraction of radium from groundwater [ 226 Ra concentration up to 7840 pCi/L (290 Bq/L) ]. In 1947, the extraction of uranium and radium from ores began. Radionuclide contamination in the Vodnyi region includes soils that had been in long-term contact with radium-rich groundwater, charcoal- and gypsum/anhydrite-bearing solid wastes associated with radium production from groundwater, and uranium/radium mill tailings (ore residues). Environmental monitoring and radioecological investigations in the region began in 1957. Due to the restrictive publication practices of the past, many of the radioecological studies done at the Vodnyi site have received limited attention outside the former Soviet Union. Our goal here is to introduce the Vodnyi site to a wider audience and to describe past and current investigations. (author)

  9. Radiation exposure of the dentist

    Energy Technology Data Exchange (ETDEWEB)

    Regulla, D F; Wachsmann, F

    1975-08-01

    The radiation doses per person undergoing dental treatment measured at the trunk is rather considerable, though not alarming. However, the number of people whose hands had been exposed to radiation as well as the individual extent of exposure were unexpectedly high. The radiation doses measured at the hands was about 100 times bigger than the radiation doses determined at the trunk for the whole body. Although these results may be very impressive, it should be borne in mind that the data on which the investigation was based date from 1967/68 and may no longer be fully applicable to the present situation. Whether and to what extent this assumption is justified ought to be found out by control studies regarding radiation doses per person and Roepak programs which are presently being started and whose results will be discussed in this journal.

  10. Biological monitoring of radiation exposure

    Science.gov (United States)

    Horneck, G.

    1998-11-01

    Complementary to physical dosimetry, biological dosimetry systems have been developed and applied which weight the different components of environmental radiation according to their biological efficacy. They generally give a record of the accumulated exposure of individuals with high sensitivity and specificity for the toxic agent under consideration. Basically three different types of biological detecting/monitoring systems are available: (i) intrinsic biological dosimeters that record the individual radiation exposure (humans, plants, animals) in measurable units. For monitoring ionizing radiation exposure, in situ biomarkers for genetic (e.g. chromosomal aberrations in human lymphocytes, germ line minisatellite mutation rates) or metabolic changes in serum, plasma and blood (e.g. serum lipids, lipoproteins, lipid peroxides, melatonin, antibody titer) have been used. (ii) Extrinsic biological dosimeters/indicators that record the accumulated dose in biological model systems. Their application includes long-term monitoring of changes in environmental UV radiation and its biological implications as well as dosimetry of personal UV exposure. (iii) Biological detectors/biosensors for genotoxic substances and agents such as bacterial assays (e.g. Ames test, SOS-type test) that are highly sensitive to genotoxins with high specificity. They may be applicable for different aspects in environmental monitoring including the International Space Station.

  11. Exposure to low level GSM 935 MHz radiofrequency fields does not induce apoptosis in proliferating or differentiated murine neuroblastoma cells

    International Nuclear Information System (INIS)

    Moquet, J.; Ainsbury, E.; Bouffler, S.; Lloyd, D.

    2008-01-01

    The aim of this study was to investigate whether radiofrequency (RF) fields characteristic of mobile phones at non-thermal levels can induce apoptosis in murine neuroblastoma (N2a) cells in both proliferating and differentiated states. Cells were exposed continuously for 24 h to one of the three 935-MHz RF signals: global system for mobile communication (GSM) basic, GSM talk and a continuous wave, unmodulated signal; all at a specific energy absorption rate of 2 W kg -1 . The measured increase in temperature of the cells due to the RF fields was around 0.06 deg. C. At a number of time points between 0 and 48 h post-exposure, the cells were assessed for apoptosis under a fluorescence microscope using three independent assays: Annexin V, caspase activation and in situ end-labelling. No statistically significant differences in apoptosis levels were observed between the exposed and sham-exposed cells using the three assays at any time point post-exposure. These data suggest that RF exposures, characteristic of GSM mobile phones, do not significantly affect the apoptosis levels in proliferating and differentiated murine neuroblastoma cell line N2a. (authors)

  12. Binding of ethylene oxide in spermiogenic germ cell stages of the mouse after low-level inhalation exposure

    International Nuclear Information System (INIS)

    Sega, G.A.; Owens, J.G.

    1987-01-01

    Mice received inhalation exposures of 3 H-labeled ethylene oxide (EtO) gas at levels from 0.65 to 3.2 parts per million-hours (ppm-hr), which are below the exposure limits currently allowed for humans. Subsequently, spermatozoa were recovered from the reproductive tracts of the animals over a two-week period and assayed for the amount of bound EtO. A strong increase in the level of EtO binding occurred in late spermatid stages; these stages are also genetically sensitive to the action of EtO. Alkylation of the DNA within the sperm accounted for a very small fraction of the total sperm head alkylation, averaging about 20 DNA alkylations per sperm per ppm-hr of exposure over the two-week period. However, alkylation of protamine, a protein unique to sperm cells, was found to be correlated with total sperm head alkylation and accounted for nearly all of the EtO binding. Protamine alkylation appears to be a significant cause of EtO-induced genetic damage in spermiogenic cells of the mammal

  13. Exercise Training under Exposure to Low Levels of Fine Particulate Matter: Effects on Heart Oxidative Stress and Extra-to-Intracellular HSP70 Ratio

    Directory of Open Access Journals (Sweden)

    Aline Sfalcin Mai

    2017-01-01

    Full Text Available Fine particulate matter (PM2.5 promotes heart oxidative stress (OS and evokes anti-inflammatory responses observed by increased intracellular 70 kDa heat shock proteins (iHSP70. Furthermore, PM2.5 increases the levels of these proteins in extracellular fluids (eHSP70, which have proinflammatory roles. We investigated whether moderate and high intensity training under exposure to low levels of PM2.5 modifies heart OS and the eHSP70 to iHSP70 ratio (H-index, a biomarker of inflammatory status. Male mice (n=32, 30 days old, were divided into six groups for 12 weeks: control (CON, moderate (MIT and high intensity training (HIT, exposure to 5 μg of PM2.5 daily (PM2.5, and moderate and high intensity training exposed to PM2.5 (MIT + PM2.5 and HIT + PM2.5 groups. The CON and PM2.5 groups remained sedentary. The MIT + PM2.5 group showed higher heart lipid peroxidation levels than the MIT and PM2.5 groups. HIT and HIT + PM2.5 showed higher heart lipid peroxidation levels and lower eHSP70 and H-index levels compared to sedentary animals. No alterations were found in heart antioxidant enzyme activity or iHSP70 levels. Moderate exercise training under exposure to low levels of PM2.5 induces heart OS but does not modify eHSP70 to iHSP70 ratio (H-index. High intensity exercise training promotes anti-inflammatory profile despite exposure to low levels of PM2.5.

  14. Occupational radiation exposure in Slovakia

    International Nuclear Information System (INIS)

    Boehm, K.; Cabanekova, H.

    2014-01-01

    Recently are 2 nuclear power plants in operation in the Slovak republic. Apart from nuclear facilities there are 450 licensed undertakings with monitored workers. The majority of the licensed undertakings are active in health care. In Slovak republic are five dosimetry services performing assessments on personal doses due to external exposure and two dosimetry services are approved to carry out monitoring of internal exposure. Dosemeters used for the monitoring of external individual exposure include: personal whole-body film dosemeters, thermoluminescence dosemeters (TLD) or optically stimulated luminescence dosimeters (OSL) for measurements of beta and gamma radiation; TLD for measurements of neutron radiation and TLD for extremities. The measured operational dose quantities are Hp(10), Hp(3) and Hp(0.07). Approved dosimetry service reports the measured dose data to the employers and to the Central register of occupational doses (CROD). Annually are monitored about 12500 - 16200 active workers. Average effective doses per one monitored worker are presented. (author)

  15. Co-exposure to lead increases the renal response to low levels of cadmium in metallurgy workers.

    Science.gov (United States)

    Hambach, R; Lison, D; D'Haese, P C; Weyler, J; De Graef, E; De Schryver, A; Lamberts, L V; van Sprundel, M

    2013-10-24

    Research on the effect of co-exposure to Cd and Pb on the kidney is scarce. The objective of the present study was to assess the effect of co-exposure to these metals on biomarkers of early renal effect. Cd in blood (Cd-B), Cd in urine (Cd-U), Pb in blood (Pb-B) and urinary renal biomarkers, i.e., microalbumin (μ-Alb), beta-2-microglobulin (β₂-MG), retinol binding protein (RBP), N-acetyl-β-d-glucosaminidase (NAG), intestinal alkaline phosphatase (IAP) were measured in 122 metallurgic refinery workers examined in a cross-sectional survey. The median Cd-B, Cd-U, Pb-B were: 0.8 μg/l (IQR = 0.5, 1.2), 0.5 μg/g creatinine (IQR = 0.3, 0.8) and 158.5 μg/l (IQR = 111.0, 219.3), respectively. The impact of Cd-B on the urinary excretion of NAG and IAP was only evident among workers with Pb-B concentrations ≥ 75th percentile. The association between Cd-U and the renal markers NAG and RBP was also evidenced when Pb-B ≥ 75th percentile. No statistically significant interaction terms were observed for the associations between Cd-B or Cd-U and the other renal markers under study (i.e., μ-Alb and β2-MG). Our findings indicate that Pb increases the impact of Cd exposure on early renal biomarkers. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  16. Radiation exposure during equine radiography

    International Nuclear Information System (INIS)

    Ackerman, N.; Spencer, C.P.; Hager, D.A.; Poulos, P.W. Jr.

    1988-01-01

    All personnel present in the X-ray examination room during equine radiography were monitored using low energy direct reading ionization chambers (pockets dosimeters) worn outside the lead apron at neck level. The individuals' task and dosimeter readings were recorded after each examination. Average doses ranged from 0 to 6 mrad per study. The greatest exposures were associated with radiography of the shoulder and averaged less than 4 mrad. The individual extending the horse's limb was at greatest risk although the individual holding the horse's halter and the one making the X-ray exposure received similar exposures. A survey of the overhead tube assembly used for some of the X-ray examinations also was performed. Meter readings obtained indicated an asymetric dose distribution around the tube assembly, with the highest dose occurring on the side to which the exposure cord was attached. Although the exposures observed were within acceptable limits for occupational workers, we have altered our protocol and no longer radiograph the equine shoulder unless the horse is anesthetized. Continued use of the pocket dosimeters and maintenance of a case record of radiation exposure appears to make the technologists more aware of radiation hazards

  17. Effect of Long Term Low-Level Gamma Radiation on Thermal Sensitivity of RDX/HMX Mixtures

    Science.gov (United States)

    1976-11-01

    1.1x10 R. It was concluded that the slight exothermic reaction before the 3^6 HMX polymorphic transition could be caused by a radiation-induced...Radiation on Thermal Sensitivity of RDX / HMX Mixtures 5. TYPE OF REPORT 4 PERIOD COVERED Final Report 6. PERFORMING ORG. REPORT NUMBER 7...and Identity by block number) Gamma radiation Weight loss HMX Impact sensitivity test RDX Vacuum stability test DTA Infrared spectrometry TGA

  18. CYP2E1 epigenetic regulation in chronic, low-level toluene exposure: Relationship with oxidative stress and smoking habit.

    Science.gov (United States)

    Jiménez-Garza, Octavio; Baccarelli, Andrea A; Byun, Hyang-Min; Márquez-Gamiño, Sergio; Barrón-Vivanco, Briscia Socorro; Albores, Arnulfo

    2015-08-01

    CYP2E1 is a versatile phase I drug-metabolizing enzyme responsible for the biotransformation of most volatile organic compounds, including toluene. Human toluene exposure increases CYP2E1 mRNA and modifies its activity in leucocytes; however, epigenetic implications of this interaction have not been investigated. To determine promoter methylation of CYP2E1 and other genes known to be affected by toluene exposure. We obtained venous blood from 24 tannery workers exposed to toluene (mean levels: 10.86+/-7mg/m(3)) and 24 administrative workers (reference group, mean levels 0.21+/-0.02mg/m(3)) all of them from the city of León, Guanajuato, México. After DNA extraction and bisulfite treatment, we performed PCR-pyrosequencing in order to measure methylation levels at promoter region of 13 genes. In exposed group we found significant correlations between toluene airborne levels and CYP2E1 promoter methylation (r=-.36, psmoke are in higher risk due to a possible CYP2E1 repression. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Qafmolla, L.

    2000-01-01

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

  20. Dose-related gene expression changes in forebrain following acute, low-level chlorpyrifos exposure in neonatal rats

    International Nuclear Information System (INIS)

    Ray, Anamika; Liu Jing; Ayoubi, Patricia; Pope, Carey

    2010-01-01

    Chlorpyrifos (CPF) is a widely used organophosphorus insecticide (OP) and putative developmental neurotoxicant in humans. The acute toxicity of CPF is elicited by acetylcholinesterase (AChE) inhibition. We characterized dose-related (0.1, 0.5, 1 and 2 mg/kg) gene expression profiles and changes in cell signaling pathways 24 h following acute CPF exposure in 7-day-old rats. Microarray experiments indicated that approximately 9% of the 44,000 genes were differentially expressed following either one of the four CPF dosages studied (546, 505, 522, and 3,066 genes with 0.1, 0.5, 1.0 and 2.0 mg/kg CPF). Genes were grouped according to dose-related expression patterns using K-means clustering while gene networks and canonical pathways were evaluated using Ingenuity Pathway Analysis (registered) . Twenty clusters were identified and differential expression of selected genes was verified by RT-PCR. The four largest clusters (each containing from 276 to 905 genes) constituted over 50% of all differentially expressed genes and exhibited up-regulation following exposure to the highest dosage (2 mg/kg CPF). The total number of gene networks affected by CPF also rose sharply with the highest dosage of CPF (18, 16, 18 and 50 with 0.1, 0.5, 1 and 2 mg/kg CPF). Forebrain cholinesterase (ChE) activity was significantly reduced (26%) only in the highest dosage group. Based on magnitude of dose-related changes in differentially expressed genes, relative numbers of gene clusters and signaling networks affected, and forebrain ChE inhibition only at 2 mg/kg CPF, we focused subsequent analyses on this treatment group. Six canonical pathways were identified that were significantly affected by 2 mg/kg CPF (MAPK, oxidative stress, NFΚB, mitochondrial dysfunction, arylhydrocarbon receptor and adrenergic receptor signaling). Evaluation of different cellular functions of the differentially expressed genes suggested changes related to olfactory receptors, cell adhesion/migration, synapse

  1. Low-level human equivalent gestational lead exposure produces sex-specific motor and coordination abnormalities and late-onset obesity in year-old mice.

    Science.gov (United States)

    Leasure, J Leigh; Giddabasappa, Anand; Chaney, Shawntay; Johnson, Jerry E; Pothakos, Konstantinos; Lau, Yuen Sum; Fox, Donald A

    2008-03-01

    Low-level developmental lead exposure is linked to cognitive and neurological disorders in children. However, the long-term effects of gestational lead exposure (GLE) have received little attention. Our goals were to establish a murine model of human equivalent GLE and to determine dose-response effects on body weight, motor functions, and dopamine neurochemistry in year-old offspring. We exposed female C57BL/6 mice to water containing 0, 27 (low), 55 (moderate), or 109 ppm (high) of lead from 2 weeks prior to mating, throughout gestation, and until postnatal day 10 (PN10). Maternal and litter measures, blood lead concentrations ([BPb]), and body weights were obtained throughout the experiment. Locomotor behavior in the absence and presence of amphetamine, running wheel activity, rotarod test, and dopamine utilization were examined in year-old mice. Peak [BPb] were obesity. Similarly, we observed male-specific decreased spontaneous motor activity, increased amphetamine-induced motor activity, and decreased rotarod performance in year-old GLE mice. Levels of dopamine and its major metabolite were altered in year-old male mice, although only forebrain utilization increased. GLE-induced alterations were consistently larger in low-dose GLE mice. Our novel results show that GLE produced permanent male-specific deficits. The nonmonotonic dose-dependent responses showed that low-level GLE produced the most adverse effects. These data reinforce the idea that lifetime measures of dose-response toxicant exposure should be a component of the neurotoxic risk assessment process.

  2. Detection of low-level environmental exposure rates due to noble gas releases from the Muehleberg nuclear power plant

    International Nuclear Information System (INIS)

    Czarnecki, J.; Volkle, H.; Pretre, S.

    1980-01-01

    The increase of radiation doses in the vicinity of the Swiss Nuclear Power Stations due to airborne releases is generally expected to be below one mrem/year (about one percent of the natural radiation dose). To prove this expected rate, long term measurements with pressure ionization chambers in the vicinity of the Muhleberg plant (BWR) were conducted. Two of these chambers were installed at places where the greatest dose rates from the noble gas plumes were expected in the two prevailing wind directions. The local dose rates were continuously registered on magnetic tape to allow minicomputer evaluation. After the fuel change in the summer of 1976 the noble gas releases from Muhleberg dropped considerably. From that time the noble gas releases consisted of a very low continuous component and some rare short-time spike compoments resulting from turbine and reactor trips. The dose due to the low continuous component was determined by correlating the dose rates at the measuring points with the release measure--ments at the stack and with weather conditions, and by subtracting the natural background. The short noble gas spikes lasted from minutes to some hours and caused small dose rate increases which were easily measured with the ionization chambers, and usually amounted to doses of some microroentgens. By further correlating these dose peaks with wind direction and stack emission measurements, determination of short time atmospheric dilution factors for existing weather situations became possible. By this process, the very low annual environmental doses in the range of 1 mrem per year were determined. (author)

  3. Diagnostic and therapeutic radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Russell, W J [Radiation Effects Research Foundation, Hiroshima (Japan)

    1975-09-01

    Diagnostic and therapeutic radiology were studied as possible contaminants in the evaluations of A-bomb survivors in the ABCC-JNIH Adult Health Study for radiation effects. Hiroshima and Nagasaki subjects received X-ray examinations elsewhere within three months of their ABCC visits at rates of 23 and 12%, respectively. Medical X-ray examinations were more frequent among survivors than comparison subjects. Hiroshima and Nagasaki radiologic practice steadily increased since 1948, and differed markedly by city. From 1946-70 the Hiroshima and Nagasaki X-ray bone marrow doses were 2,300 and 1,000 g-rads, respectively. By 1970, cumulated medical X-ray doses approximated A-bomb doses at distances from the hypocenters of 2,000 m in Hiroshima and 2,800 m in Nagasaki. ABCC X-ray examination doses per subject are routinely updated for comparison with A-bomb doses. Each subject's reported fluoroscopy, photofluorography and radiation therapy exposure elsewhere are for future reference. Dental radiography, though increasing, was not currently an important contributor to survivors' overall exposure. Radiation therapy exposures of 137 subjects were confirmed, and doses estimated for most. Two-thirds the treatments were for malignancies; therapy differed markedly by city; and five cancers possibly arose from earlier radiation therapy. This underscores the importance of considering diagnostic and therapeutic radiology when attributing diseases to the atomic bombs.

  4. The feasibility of epidemiologic investigations of the health effects of low-level ionizing radiation. Final report, 3 July 1979-30 October 1980

    International Nuclear Information System (INIS)

    Dreyer, N.A.; Kohn, H.I.; Clapp, R.W.; Covino, S.J. Jr.; Fahey, F.H.

    1980-11-01

    This is the final report of 'A Study to Determine the Feasibility of Conducting Epidemiologic Investigations of the Health Effects of Low-Level Ionizing Radiation', begun July 3, 1979. The study defines low-level ionizing radiation as a single dose of 5 rem (whole-body) or less and chronic doses that accumulate at the rate of less than 5 rem per year. The objective of this project was to determine whether or not further epidemiologic research (either expansion of current projects or initiation of new ones) would be useful at this time for quantitating the health effects due to low-level ionizing radiation. No outstanding candidate population is recommended for study since, even if the largest available populations are studied, the chance of finding a definite positive result is very small. However, the decision to conduct a study must rest heavily on social and political considerations rather than on purely scientific ones. Therefore, four populations are tentatively proposed for prospective cohort studies, with nested case-control studies as needed. Overall, the most practical approach would be to conduct a study through a national worker registry, with cancer as the endpoint of interest

  5. 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.

  6. 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

  7. Risk of death from cardiovascular disease associated with low-level arsenic exposure among long-term smokers in a US population-based study

    International Nuclear Information System (INIS)

    Farzan, Shohreh F.; Chen, Yu; Rees, Judy R.; Zens, M. Scot; Karagas, Margaret R.

    2015-01-01

    High levels of arsenic exposure have been associated with increases in cardiovascular disease risk. However, studies of arsenic's effects at lower exposure levels are limited and few prospective studies exist in the United States using long-term arsenic exposure biomarkers. We conducted a prospective analysis of the association between toenail arsenic and cardiovascular disease mortality using longitudinal data collected on 3939 participants in the New Hampshire Skin Cancer Study. Using Cox proportional hazard models adjusted for potential confounders, we estimated hazard ratios and 95% confidence intervals associated with the risk of death from any cardiovascular disease, ischemic heart disease, and stroke, in relation to natural-log transformed toenail arsenic concentrations. In this US population, although we observed no overall association, arsenic exposure measured from toenail clipping samples was related to an increased risk of ischemic heart disease mortality among long-term smokers (as reported at baseline), with increased hazard ratios among individuals with ≥ 31 total smoking years (HR: 1.52, 95% CI: 1.02, 2.27), ≥ 30 pack-years (HR: 1.66, 95% CI: 1.12, 2.45), and among current smokers (HR: 1.69, 95% CI: 1.04, 2.75). These results are consistent with evidence from more highly exposed populations suggesting a synergistic relationship between arsenic exposure and smoking on health outcomes and support a role for lower-level arsenic exposure in ischemic heart disease mortality. - Highlights: • Arsenic (As) has been associated with increased cardiovascular disease (CVD) risk. • Little is known about CVD effects at lower levels of As exposure common in the US. • Few have investigated the joint effects of As and smoking on CVD in US adults. • We examine chronic low-level As exposure and smoking in relation to CVD mortality. • Arsenic exposure may increase ischemic heart disease mortality among smokers in US

  8. Risk of death from cardiovascular disease associated with low-level arsenic exposure among long-term smokers in a US population-based study

    Energy Technology Data Exchange (ETDEWEB)

    Farzan, Shohreh F. [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States); Departments of Population Health and Environmental Medicine, New York University School of Medicine, New York, NY (United States); Chen, Yu [Departments of Population Health and Environmental Medicine, New York University School of Medicine, New York, NY (United States); Rees, Judy R.; Zens, M. Scot [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States); Karagas, Margaret R., E-mail: margaret.r.karagas@dartmouth.edu [Department of Epidemiology, Geisel School of Medicine at Dartmouth, Lebanon, NH (United States)

    2015-09-01

    High levels of arsenic exposure have been associated with increases in cardiovascular disease risk. However, studies of arsenic's effects at lower exposure levels are limited and few prospective studies exist in the United States using long-term arsenic exposure biomarkers. We conducted a prospective analysis of the association between toenail arsenic and cardiovascular disease mortality using longitudinal data collected on 3939 participants in the New Hampshire Skin Cancer Study. Using Cox proportional hazard models adjusted for potential confounders, we estimated hazard ratios and 95% confidence intervals associated with the risk of death from any cardiovascular disease, ischemic heart disease, and stroke, in relation to natural-log transformed toenail arsenic concentrations. In this US population, although we observed no overall association, arsenic exposure measured from toenail clipping samples was related to an increased risk of ischemic heart disease mortality among long-term smokers (as reported at baseline), with increased hazard ratios among individuals with ≥ 31 total smoking years (HR: 1.52, 95% CI: 1.02, 2.27), ≥ 30 pack-years (HR: 1.66, 95% CI: 1.12, 2.45), and among current smokers (HR: 1.69, 95% CI: 1.04, 2.75). These results are consistent with evidence from more highly exposed populations suggesting a synergistic relationship between arsenic exposure and smoking on health outcomes and support a role for lower-level arsenic exposure in ischemic heart disease mortality. - Highlights: • Arsenic (As) has been associated with increased cardiovascular disease (CVD) risk. • Little is known about CVD effects at lower levels of As exposure common in the US. • Few have investigated the joint effects of As and smoking on CVD in US adults. • We examine chronic low-level As exposure and smoking in relation to CVD mortality. • Arsenic exposure may increase ischemic heart disease mortality among smokers in US.

  9. Atomic veterans and their families: Responses to radiation exposure

    International Nuclear Information System (INIS)

    Murphy, B.C.; Ellis, P.; Greenberg, S.

    1990-01-01

    In-depth interviews with seven atomic veterans and their families indicated powerful psychological effects on all family members from exposure to low-level ionizing radiation. Four themes emerged: the invalidation of their experiences by government and other authority figures; family concerns about genetic effects on future generations; family members' desire to protect each other from fears of physical consequences; and desire to leave a record of their experiences to help prevent future suffering

  10. Radiation exposure by using unsealed radiation sources

    International Nuclear Information System (INIS)

    Preitfellner, J.

    1999-05-01

    Investigations on patients using radioactive substances are performed on a routinely basis in nuclear medicine facilities at many hospitals in our days. These investigations are performed by administering a radiopharmacon to the patient which, depending on several parameters, remains in the body of the patient for various periods of time. All these investigations have in common a g-ray exposure of the environment by the radioactive substance in the body of the patient. Among others, doctors, technical personnel, cleaning personnel, and accompanying persons of patients are exposed to g-rays. Based on these facts, the degree of danger for persons who get into contact with these patients is repeatedly questioned. An additional problem is the health risk of persons employed at a nuclear medicine facility. To answer the first question, the local dose rate in the environment of 102 patients was evaluated immediately after application of the radioactive substance, in intervals from 30 minutes up to several hours, over a period of up to 2 weeks. Depending on the nature of the investigation, the patients were subdivided into 6 groups of 16-20 persons. From the data measured, the effective and the biological half life as well as the local dose were computed. With the aid of concrete case examples, the possible radiation exposure for contact persons was estimated. Postulating unfavorable local and temporal factors in our estimations, the actual radiation exposure is to be estimated about 10-30 % lower. As a reference value for the danger of persons, the maximum permissible boundary values from the Austrian Regulations for Protection against Radiation were used. Referring to these boundary values, for none of the six nuclear medicine investigation methods a danger for contact persons could be derived, indicating that available security measures offer a sufficient protection for affected contact persons. To answer the question about the risk for persons employed at a nuclear

  11. Cellular and molecular research to reduce uncertainties in estimates of health effects from low-level radiation

    Energy Technology Data Exchange (ETDEWEB)

    Elkind, M.M.; Bedford, J.; Benjamin, S.A.; Waldren, C.A. (Colorado State Univ., Fort Collins, CO (USA)); Gotchy, R.L. (Science Applications International Corp., McLean, VA (USA))

    1990-10-01

    A study was undertaken by five radiation scientists to examine the feasibility of reducing the uncertainties in the estimation of risk due to protracted low doses of ionizing radiation. In addressing the question of feasibility, a review was made by the study group: of the cellular, molecular, and mammalian radiation data that are available; of the way in which altered oncogene properties could be involved in the loss of growth control that culminates in tumorigenesis; and of the progress that had been made in the genetic characterizations of several human and animal neoplasms. On the basis of this analysis, the study group concluded that, at the present time, it is feasible to mount a program of radiation research directed at the mechanism(s) of radiation-induced cancer with special reference to risk of neoplasia due to protracted, low doses of sparsely ionizing radiation. To implement a program of research, a review was made of the methods, techniques, and instruments that would be needed. This review was followed by a survey of the laboratories and institutions where scientific personnel and facilities are known to be available. A research agenda of the principal and broad objectives of the program is also discussed. 489 refs., 21 figs., 14 tabs.

  12. Cellular and molecular research to reduce uncertainties in estimates of health effects from low-level radiation

    International Nuclear Information System (INIS)

    Elkind, M.M.; Bedford, J.; Benjamin, S.A.; Waldren, C.A.; Gotchy, R.L.

    1990-10-01

    A study was undertaken by five radiation scientists to examine the feasibility of reducing the uncertainties in the estimation of risk due to protracted low doses of ionizing radiation. In addressing the question of feasibility, a review was made by the study group: of the cellular, molecular, and mammalian radiation data that are available; of the way in which altered oncogene properties could be involved in the loss of growth control that culminates in tumorigenesis; and of the progress that had been made in the genetic characterizations of several human and animal neoplasms. On the basis of this analysis, the study group concluded that, at the present time, it is feasible to mount a program of radiation research directed at the mechanism(s) of radiation-induced cancer with special reference to risk of neoplasia due to protracted, low doses of sparsely ionizing radiation. To implement a program of research, a review was made of the methods, techniques, and instruments that would be needed. This review was followed by a survey of the laboratories and institutions where scientific personnel and facilities are known to be available. A research agenda of the principal and broad objectives of the program is also discussed. 489 refs., 21 figs., 14 tabs

  13. Prenatal radiation exposure. Dose calculation

    International Nuclear Information System (INIS)

    Scharwaechter, C.; Schwartz, C.A.; Haage, P.; Roeser, A.

    2015-01-01

    The unborn child requires special protection. In this context, the indication for an X-ray examination is to be checked critically. If thereupon radiation of the lower abdomen including the uterus cannot be avoided, the examination should be postponed until the end of pregnancy or alternative examination techniques should be considered. Under certain circumstances, either accidental or in unavoidable cases after a thorough risk assessment, radiation exposure of the unborn may take place. In some of these cases an expert radiation hygiene consultation may be required. This consultation should comprise the expected risks for the unborn while not perturbing the mother or the involved medical staff. For the risk assessment in case of an in-utero X-ray exposition deterministic damages with a defined threshold dose are distinguished from stochastic damages without a definable threshold dose. The occurrence of deterministic damages depends on the dose and the developmental stage of the unborn at the time of radiation. To calculate the risks of an in-utero radiation exposure a three-stage concept is commonly applied. Depending on the amount of radiation, the radiation dose is either estimated, roughly calculated using standard tables or, in critical cases, accurately calculated based on the individual event. The complexity of the calculation thereby increases from stage to stage. An estimation based on stage one is easily feasible whereas calculations based on stages two and especially three are more complex and often necessitate execution by specialists. This article demonstrates in detail the risks for the unborn child pertaining to its developmental phase and explains the three-stage concept as an evaluation scheme. It should be noted, that all risk estimations are subject to considerable uncertainties.

  14. Radiation exposure in diagnostic medicine

    International Nuclear Information System (INIS)

    Haehnel, S.; Michalczak, H.; Reinoehl-Kompa, S.

    1995-01-01

    This volume includes the manuscripts of the papers read at the conference as well as a summary and assessment of its results. The scientific discussions were centred upon the following issues: - International surveys and comparisons of rdiation exposures in diagnostic radiology and nuclear medicine, frequency of the individual diagnostic procedures and age distribution of patients examined; - policies and regulations for the radiation protection of patients, charcteristic dosimetric values and practical usefulness of the effective dose concept during medical examinations; - assessments of the relative benefits and risks and measures to reduce the radiation exposure in the light of quality assurance aspects. The main objective of this conference not only was to evaluate the risks from diagnostic radiology and nuclear medicine but also to encourgage a critical analysis and adjustment of examination routines followed in everyday practice. Among the measures recommended were quality assurance, maintenace of international standards, development of guidelines, introduction of standard doses, improved training and professional education of personnel as well as surveys and analyses of certain examination procedures associated with substantial radiation exposure. (orig./MG) [de

  15. Radiation exposure in monazite industry

    Energy Technology Data Exchange (ETDEWEB)

    Paul, A C [Bhabha Atomic Research Centre, Bombay (India). Health Physics Div.

    1979-04-01

    The monazite present in the beach sands of Kerala and Tamil Nadu (India) is separated in the mineral separation plants at Manavalakurichi and Chavara, operated by M/s Indian Rare Earths Ltd. The physical and chemical processing of the sand involves radiation hazards due to the presence of thorium, uranium and their daughter products in monazite. The paper reviews present status in the light of past experiences and analyses the dose apportionment in different work catagories. The problem of internal contamination and environmental radiation levels are also discussed with the help of the recently available data. Radiation fields in the physical processing of monazite at different stages are presented. Apportionment of doses at different stages of the chemical operation involving 10 tonne lots of monazite is presented in a tabular form. The changing trend in external exposure reflected in the man-rem/t of monazite over the years is illustrated in a graph.

  16. Techniques for controlling radiation exposure

    International Nuclear Information System (INIS)

    Ocken, H.; Wood, C.J.

    1993-01-01

    The US nuclear power industry has been remarkably successful in reducing worker radiation exposure over the past 10 years. There has been more than a fourfold reduction in person-rem per MW-year of electric power generated: from 1.8 person-rems in 1980 to only 0.4 person-rems in 1991. Despite this substantial improvement, challenges for the industry remain. Individual exposure limits have been tightened in the 1990 Recommendations of the International Commission on Radiological Protection, ICRP Publication 60, and there will be more requirements for special maintenance work as plants age, suggesting that vigorous efforts will be required to meet the 1995 industry goals for unit median collective exposure. No one method will suffice, but implementing suitable combinations from this compendium will help utilities to achieve their exposure goals. Radiation reduction is generally cost-effective: Outages are shorter, staffing requirements are reduced, and work quality is improved. Despite up-front costs, the benefits over the following one to three years typically outweigh the expenses

  17. Radiation exposure and chromosome damage

    International Nuclear Information System (INIS)

    Lloyd, D.

    1979-01-01

    Chromosome damage is discussed as a means of biologically measuring radiation exposure to the body. Human lymphocytes are commonly used for this test since the extent of chromosome damage induced is related to the exposure dose. Several hundred lymphocytes are analysed in metaphase for chromosome damage, particularly dicentrics. The dose estimate is made by comparing the observed dicentric yield against calibration curves, previously produced by in vitro irradiation of blood samples to known doses of different types of radiation. This test is useful when there is doubt that the film badge has recorded a reasonable whole body dose and also when there is an absence of any physical data. A case of deliberate exposure is described where the chromosome damage test estimated an exposure of 152 rads. The life span of cell aberrations is also considered. Regular checks on radiotherapy patients and some accidental overdose cases have shown little reduction in the aberration levels over the first six weeks after which the damage disappears slowly with a half-life of about three years. In conclusion, chromosome studies have been shown to be of value in resolving practical problems in radiological protection. (U.K.)

  18. Radiation exposure analysis of female nuclear medicine radiation workers

    International Nuclear Information System (INIS)

    Lee, Ju Young; Park, Hoon Hee

    2016-01-01

    In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus

  19. Radiation exposure analysis of female nuclear medicine radiation workers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju Young [Dept. of Biomedical Engineering Graduate School, Chungbuk National University, Cheongju (Korea, Republic of); Park, Hoon Hee [Dept. of Radiological Technologist, Shingu College, Sungnam (Korea, Republic of)

    2016-06-15

    In this study, radiation workers who work in nuclear medicine department were analyzed to find the cause of differences of radiation exposure from General Characteristic, Knowledge, Recognition and Conduct, especially females working on nuclear medicine radiation, in order to pave the way for positive defense against radiation exposure. The subjects were 106 radiation workers who were divided into two groups of sixty-four males and forty-two females answered questions about their General Characteristic, Knowledge, Recognition, Conduct, and radiation exposure dose which was measured by TLD (Thermo Luminescence Dosimeter). The results of the analysis revealed that as the higher score of knowledge and conduct was shown, the radiation exposure decreased in female groups, and as the higher score of conduct was shown, the radiation exposure decreased in male groups. In the correlation analysis of female groups, the non-experienced in pregnancy showed decreasing amount of radiation exposure as the score of knowledge and conduct was higher and the experienced in pregnancy showed decreasing amount of radiation exposure as the score of recognition and conduct was higher. In the regression analysis on related factors of radiation exposure dose of nuclear medicine radiation workers, the gender caused the meaningful result and the amount of radiation exposure of female groups compared to male groups. In the regression analysis on related factors of radiation exposure dose of female groups, the factor of conduct showed a meaningful result and the amount of radiation exposure of the experienced in pregnancy was lower compared to the non-experienced. The conclusion of this study revealed that radiation exposure of female groups was lower than that of male groups. Therefore, male groups need to more actively defend themselves against radiation exposure. Among the female groups, the experienced in pregnancy who have an active defense tendency showed a lower radiation exposure. Thus

  20. Radiation exposure and radiation hazards of human population. Pt. 1

    International Nuclear Information System (INIS)

    Jacobi, W.

    1982-01-01

    The present Part I provides a survey on the various sources of natural and artificial radiation exposure of human population. Furthermore, biological radiation effects and radiation damages are surveyed. In an appendix, radiation types, radiation doses, and radiation dose units are explained. (orig./GSCH) [de

  1. A cytogenetic bio-monitoring of industrial radiographers occupationally exposed to low levels of ionizing radiation by using CBMN assay

    International Nuclear Information System (INIS)

    Shakeri, Mahsa; Changizi, Vahid; Zakeri, Farideh; Rajabpour, Mohammad Reza; Farshidpour, Mohammad Reza

    2017-01-01

    Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. The average annual effective dose in industrial radiography is one of the highest among radiation workers. The aim of this study was to investigate the cytogenetic effects of ionizing radiation in the peripheral blood lymphocytes of 60 industrial radiographers and 40 non-exposed individuals as the control group by using cytokinesis-block micronucleus (CBMN) assay. Totally, the frequencies of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were significantly higher in the industrial radiographers than in the controls (p = 0.000). The mean MN frequency per 1000 binucleated cells in the industrial radiographers with last 5-y radiation dose of >100 mSv was significantly higher than those with ≤100 mSv (34.81 ± 12.70 vs. 26.33 ± 7.940, p = 0.024). The effect of age was observed in the control group and subjects with the age of >30 y showed significantly higher MN frequency compared with the subjects with the age of ≤30 y (9.45 ± 3.710 vs. 6.81 ± 3.050, p = 0.02). No obvious trend of increased MN as a function of either duration of employment or age or smoking status was observed in the industrial radiographers. The results show the increased levels of cytogenetic damages in the industrial radiographers. Even the workers exposed to the permissible doses are subjected to elevated frequencies of DNA damages. These findings confirm the importance of cytogenetic bio-monitoring program beside physical dosimetry, surveying radiation safety of equipment and periodic training of workers for improvement of safety and radiation protection. (authors)

  2. Occupational radiation exposures in Cyprus

    Energy Technology Data Exchange (ETDEWEB)

    Kaplanis, Prodromos A; Christofides, Stelios [Medical Physics Department, Nicosia General Hospital, 1450 Nicosia (Cyprus)

    1999-12-31

    For the first time ever the occupational radiation exposure data of all the radiation workers of Cyprus, as obtained by the personnel monitoring service of the Dosimetry Laboratory of the Medical Physics Department of the Ministry of Health, is published and compared with that of other countries. The presented data shows a systematic trend of improvement both with regards to the methodology of monitoring and data recording. The efforts of the past few years in educating and training the users of ionising radiation with regards to the importance of the personnel monitoring service and the hazards of ionising radiation, has paid off and this is evident from the doses recorded in the past three years which are compared favourably with those of other countries, as given by the UNSCEAR 1993 report. The introduction of extremity monitoring, promises even better improvement in the methodology of monitoring the doses received by personnel working in Interventional Radiology, as well as other groups whose hands, unavoidably, come close to radiation sources. (authors) 3 refs., 12 tabs.

  3. Metabonomics evaluation of urine from rats administered with phorate under long-term and low-level exposure by ultra-performance liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Sun, Xiaowei; Xu, Wei; Zeng, Yan; Hou, Yurong; Guo, Lin; Zhao, Xiujuan; Sun, Changhao

    2014-02-01

    The purpose of this study was to investigate the toxic effect of long-term and low-level exposure to phorate using a metabonomics approach based on ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Male Wistar rats were given phorate daily in drinking water at low doses of 0.05, 0.15 or 0.45 mg kg⁻¹ body weight (BW) for 24 weeks consecutively. Rats in the control group were given an equivalent volume of drinking water. Compared with the control group, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBIL), urea nitrogen (BUN) and creatinine (CR) were increased in the middle- and high-dose groups whereas albumin (ALB) and cholinesterase (CHE) were decreased. Urine metabonomics profiles were analyzed by UPLC-MS. Compared with the control group, 12 metabolites were significantly changed in phorate-treated groups. In the negative mode, metabolite intensities of uric acid, suberic acid and citric acid were significantly decreased in the middle- and high-dose groups, whereas indoxyl sulfic acid (indican) and cholic acid were increased. In the positive mode, uric acid, creatinine, kynurenic acid and xanthurenic acid were significantly decreased in the middle- and high-dose groups, but 7-methylguanine (N⁷G) was increased. In both negative and positive modes, diethylthiophosphate (DETP) was significantly increased, which was considered as a biomarker of exposure to phorate. In conclusion, long-term and low-level exposure to phorate can cause disturbances in energy-related metabolism, liver and kidney function, the antioxidant system, and DNA damage. Moreover, more information can be provided on the evaluation of toxicity of phorate using metabonomics combined with clinical chemistry. Copyright © 2012 John Wiley & Sons, Ltd.

  4. Low level and sub-chronic exposure to methylmercury induces hypertension in rats: nitric oxide depletion and oxidative damage as possible mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Grotto, Denise; Barcelos, Gustavo R.M.; Barbosa, Fernando [Universidade de Sao Paulo, Departamento de Analises Clinicas, Toxicologicas e Bromatologicas, Faculdade de Ciencias Farmaceuticas de Ribeirao Preto, Ribeirao Preto, SP (Brazil); Castro, Michele M. de [Universidade de Sao Paulo, Departamento de Farmacologia, Faculdade de Medicina de Ribeirao Preto, Ribeirao Preto, SP (Brazil); Garcia, Solange C. [Universidade Federal de Santa Maria, Departamento de Analises Clinicas e Toxicologicas, Santa Maria, Rio Grande do Sul (Brazil)

    2009-07-15

    Increased risk of hypertension after methylmercury (MeHg) exposure has been suggested. However, the underlying mechanisms are not well explored. In this paper, we have analyzed whether sub-chronic exposure to MeHg increases systolic blood pressure even at very low levels. In addition, we analyzed if the methylmercury-induced hypertension is associated with a decreased plasmatic nitric oxide levels and with a dysregulation of the activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), as well as the levels of MDA and glutathione. For this study, Wistar rats were treated with methylmercury chloride (100 {mu}g/kg per day) or vehicle. Total treatment time was 100 days. Malondialdehyde (MDA) and circulating NOx levels and superoxide dismutase (SOD) and catalase (CAT) activities were determined in plasma, whereas glutathione levels were determined in erythrocytes. Our results show that long-term treatment at a low level of MeHg affected systolic blood pressure, increasing and reducing the levels of plasmatic MDA and NOx, respectively. However, the activity of SOD did not decrease in the MeHg exposed group when compared to the control. We found a negative correlation between plasmatic nitrite/nitrate (NOx) levels and systolic blood pressure (r=-0.67; P=0.001), and a positive correlation between MDA and systolic blood pressure (r=0.61; P=0.03), thus suggesting increased inhibition of NO formation with the increase of hypertension. In conclusion, long-term exposure to a low dose of MeHg increases the systolic pressure and is associated, at least in part, with increased production of ROS as judged by increased production of malondialdehyde and depressed NO availability. (orig.)

  5. A cytogenetic biomonitoring of industrial radiographers occupationally exposed to low levels of ionizing radiation by using cbmn assay.

    Science.gov (United States)

    Shakeri, Mahsa; Zakeri, Farideh; Changizi, Vahid; Rajabpour, Mohammad Reza; Farshidpour, Mohammad Reza

    2017-06-15

    Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. The average annual effective dose in industrial radiography is one of the highest among radiation workers. The aim of this study was to investigate the cytogenetic effects of ionizing radiation in the peripheral blood lymphocytes of 60 industrial radiographers and 40 non-exposed individuals as the control group by using cytokinesis-block micronucleus (CBMN) assay. Totally, the frequencies of micronuclei (MN), nucleoplasmic bridges (NPBs) and nuclear buds (NBUDs) were significantly higher in the industrial radiographers than in the controls (p = 0.000). The mean MN frequency per 1000 binucleated cells in the industrial radiographers with last 5-y radiation dose of >100 mSv was significantly higher than those with ≤100 mSv (34.81 ± 12.7‰ vs. 26.33 ± 7.94‰, p = 0.024). The effect of age was observed in the control group and subjects with the age of >30 y showed significantly higher MN frequency compared with the subjects with the age of ≤30 y (9.45 ± 3.71‰ vs. 6.81 ± 3.05‰, p = 0.02). No obvious trend of increased MN as a function of either duration of employment or age or smoking status was observed in the industrial radiographers. The results show the increased levels of cytogenetic damages in the industrial radiographers. Even the workers exposed to the permissible doses are subjected to elevated frequencies of DNA damages. These findings confirm the importance of cytogenetic biomonitoring program beside physical dosimetry, surveying radiation safety of equipment and periodic training of workers for improvement of safety and radiation protection. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Epidemiological surveys on the effects of low-level radiation dose: a comparative assessment. Vol. A: pre-conception irradiation effects. Vol. E (DRAFT A): group collation tables

    Energy Technology Data Exchange (ETDEWEB)

    Rose, K.S.B.

    1988-01-01

    In this report, the health effects of low-level doses of radiation are considered by reference to published epidemiological surveys. The work was carried out with three objectives in mind: 1. to provide a comprehensive and critical review of the subject; 2. to seek consistent indications of particular health effects by collating results and comparing with those from surveys at moderate-level doses; 3. to provide an authoritative view on the epidemiology of low-level radiation-induced health effects. Vol E (DRAFT A) is appended and contains group collation tables. Epidemiological surveys can be conveniently divided into four classes (A, B, C, D) according to the phase of life when irradiation occurs or the effect is diagnosed. The first of the classes (A) is addressed here; this class is concerned with possible effects arising from radiation received by a parent before conception. Possible effects of preconception irradiation were identified under four broad groupings. These are Down's syndrome, ''Indicators of Reproductive Damage'' (mainly Primary Sterility, Congenital Abnormalities, Sex Ratio, Fetal Mortality, Infant Mortality), Childhood Malignancies, and Chromosomal Changes in Abortuses. Information about each survey, and comparisons with results from moderate-level dose surveys, are contained in synopses that are set out in the Appendix.

  7. Effects of low-level exposure to sarin and cyclosarin during the 1991 Gulf War on brain function and brain structure in US veterans.

    Science.gov (United States)

    Chao, Linda L; Rothlind, Johannes C; Cardenas, Valerie A; Meyerhoff, Dieter J; Weiner, Michael W

    2010-09-01

    Potentially more than 100,000 US troops may have been exposed to the organophosphate chemical warfare agents sarin (GB) and cyclosarin (GF) when a munitions dump at Khamisiyah, Iraq was destroyed during the Gulf War (GW) in 1991. Although little is known about the long-term neurobehavioral or neurophysiological effects of low-dose exposure to GB/GF in humans, recent studies of GW veterans from the Devens Cohort suggest decrements in certain cognitive domains and atrophy in brain white matter occur individuals with higher estimated levels of presumed GB/GF exposure. The goal of the current study is to determine the generalizability of these findings in another cohort of GW veterans with suspected GB/GF exposure. Neurobehavioral and imaging data collected in a study on Gulf War Illness between 2002 and 2007 were used in this study. We focused on the data of 40 GW-deployed veterans categorized as having been exposed to GB/GF at Khamisiyah, Iraq and 40 matched controls. Magnetic resonance images (MRI) of the brain were analyzed using automated and semi-automated image processing techniques that produced volumetric measurements of gray matter (GM), white matter (WM), cerebrospinal fluid (CSF) and hippocampus. GW veterans with suspected GB/GF exposure had reduced total GM and hippocampal volumes compared to their unexposed peers (p< or =0.01). Although there were no group differences in measures of cognitive function or total WM volume, there were significant, positive correlations between total WM volume and measures of executive function and visuospatial abilities in veterans with suspected GB/GF exposure. These findings suggest that low-level exposure to GB/GF can have deleterious effects on brain structure and brain function more than decade later. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Relationship between human respiratory reactivity and neutrophil metabolism under intermittent hypoxic influences in humans exposed to low-level radiation

    International Nuclear Information System (INIS)

    Serebrovskaya, T.V.; Oberenko, O.A.; Guseva, S.A.

    1996-01-01

    The group of 18 men exposed to radiation during amelioration work in the Chernobyl NPP was examined in the course of adaptation to intermittent hypoxia (rebreathing technique during 10 days of three dayly 5-7 min sessions with 15 min break). The starting level of ventilatory response to hypoxic stimulus (HVR) did not differ from the one in persons living in non-contaminated areas. This hypoxic training (HT) caused the increase of HVR, activity of NADPH-oxidase and cationic protein content in neutrophyls as well as various changes in mieloperoxidase activity. The correlation between respiration reactivity and deviations in neutrophil metabolism under HT was found. 14 refs., 2 figs

  9. Paramecium aurelia as a cellular model used for studies of the biological effects of natural ionizing radiation or chronic low-level irradiation

    International Nuclear Information System (INIS)

    Planel, H.; Soleilhavoup, J.P.; Tixador, R.; Croute, F.; Richoilley, G.

    1979-01-01

    Paramecium aurelia appears to be a very suitable object for investigating the biological effects of natural ionizing radiation or the influence of low doses of radiation. The biological effects of ionizing radiation on cell proliferation kinetics were tested. It is shown that radio-protection or chronic exposure to very low doses of 60 Co gamma rays induce different changes in cell growth rate. Special experimental techniques can help to obtain more obvious results using cells more sensitive to the stimulating effects of low doses of ionizing radiation. (author)

  10. Estimate of radiation damage to low-level electronics of the RF system in the LHC cavities arising from beam gas collisions

    International Nuclear Information System (INIS)

    Butterworth, A.; Ferrari, A.; Tsoulou, E.; Vlachoudis, V.; Wijnands, T.

    2005-01-01

    Monte Carlo simulations have been performed to estimate the radiation damage induced by high-energy hadrons in the digital electronics of the RF low-level systems in the LHC cavities. High-energy hadrons are generated when the proton beams interact with the residual gas. The contributions from various elements - vacuum chambers, cryogenic cavities, wideband pickups and cryo-module beam tubes - have been considered individually, with each contribution depending on the gas composition and density. The probability of displacement damage and single event effects (mainly single event upsets) is derived for the LHC start-up conditions. (authors)

  11. Estimate of radiation damage to low-level electronics of the RF system in the LHC cavities arising from beam gas collisions.

    Science.gov (United States)

    Butterworth, A; Ferrari, A; Tsoulou, E; Vlachoudis, V; Wijnands, T

    2005-01-01

    Monte Carlo simulations have been performed to estimate the radiation damage induced by high-energy hadrons in the digital electronics of the RF low-level systems in the LHC cavities. High-energy hadrons are generated when the proton beams interact with the residual gas. The contributions from various elements-vacuum chambers, cryogenic cavities, wideband pickups and cryomodule beam tubes-have been considered individually, with each contribution depending on the gas composition and density. The probability of displacement damage and single event effects (mainly single event upsets) is derived for the LHC start-up conditions.

  12. Unintentional exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Sliney, D.H.

    1987-01-01

    To evaluate the risks from unintentional exposure to ultraviolet radiation (UVR), and to consider hazard control regulation, one must face first the problem of their state of scientific knowledge and the public's perception of UVR. Few people in the general public would question the health benefits of sunlight. Many flock to the beaches each summer to develop a healthy tan. Since the 1920's scientists have recognized that most of the benefits--and risks--of sunlight exposure result from the UVR present in sunlight. Dermatologists warn sunbathers to avoid exposure or protect themselves against the intense midday UVR or risk skin cancer. A growing number of scientists warn of hazards to the eye if UVR--perhaps even shorter visible wavelengths--are not filtered by lenses. In addition to any intentional exposure for health or cosmetic purposes, many people are also exposed to UVR without being aware of it or without their intent to be exposed. Outdoor workers are exposed to sunlight, many industrial workers (e.g., welders) are exposed to UVR from arc sources, some UVR penetrates clothing, and people indoors are exposed to UVR from artificial lighting

  13. Application and possible mechanisms of combining LLLT (low level laser therapy), infrared hyperthermia and ionizing radiation in the treatment of cancer

    Science.gov (United States)

    Abraham, Edward H.; Woo, Van H.; Harlin-Jones, Cheryl; Heselich, Anja; Frohns, Florian

    2014-02-01

    Benefit of concomitant infrared hyperthermia and low level laser therapy and ionizing radiation is evaluated in this study. The purpose/objectives: presentation with locally advanced bulky superficial tumors is clinically challenging. To enhance the efficacy of chemotherapy and IMRT (intensity-modulated radiation therapy) and/or electron beam therapy we have developed an inexpensive and clinically effective infrared hyperthermia approach that combines black-body infrared radiation with halogen spectrum radiation and discrete wave length infrared clinical lasers LLLT. The goal is to produce a composite spectrum extending from the far infrared to near infrared and portions of the visible spectrum with discrete penetrating wavelengths generated by the clinical infrared lasers with frequencies of 810 nm and/or 830 nm. The composite spectrum from these sources is applied before and after radiation therapy. We monitor the surface and in some cases deeper temperatures with thermal probes, but use an array of surface probes as the limiting safe thermal constraint in patient treatment while at the same time maximizing infrared entry to deeper tissue layers. Fever-grade infrared hyperthermia is produced in the first centimeters while non-thermal infrared effects act at deeper tissue layers. The combination of these effects with ionizing radiation leads to improved tumor control in many cancers.

  14. Natural and anthropogenic radiation exposure of humans in Germany

    International Nuclear Information System (INIS)

    Koelzer, Winfried

    2016-12-01

    The contribution on natural and anthropogenic radiation exposure in Germany covers the following issues: (1) natural radiation exposure: external radiation exposure - cosmic and terrestric radiation, internal radiation exposure - primordial and cosmogenic radionuclides; radiation exposure due to sola neutrinos and geo-neutrinos. (2) Anthropogenic radiation exposure: radiation exposure in medicine, radioactivity in industrial products, radiation exposure during flights, radiation exposure due to nuclear facilities, radiation exposure due to fossil energy carriers in power generation, radiation exposure due to nuclear explosions, radiation exposure due to nuclear accidents. (3) Occupational radiation exposure in Germany: radiation monitoring with personal dosimeters in medicine and industry, dose surveillance of the aviation personal, working places with increases radiation exposure by natural radiation sources.

  15. Neighborhood Perceptions and Cumulative Impacts of Low Level Chronic Exposure to Fine Particular Matter (PM2.5 on Cardiopulmonary Health

    Directory of Open Access Journals (Sweden)

    Kristen M. C. Malecki

    2018-01-01

    Full Text Available Adverse perceptions of neighborhood safety, aesthetics and quality including access to resources can induce stress and may make individuals more sensitive to cardiopulmonary effects of air pollution exposure. Few studies have examined neighborhood perceptions as important and modifiable non-chemical stressors of the built environment that may exacerbate effects of air pollution on cardiopulmonary health outcomes, particularly among general population based cohorts. This study examined associations between low-level chronic exposure to fine particulate matter (PM2.5 and cardiopulmonary health, and the potential mediating or modifying effects of adverse neighborhood perceptions. Using data from the Survey of the Health of Wisconsin (SHOW, 2230 non-asthmatic adults age 21–74 were included in the analyses. The overall goals of this study were to assess if individuals who experience stress from neighborhood environments in which they live were more sensitive to low levels of fine particular matter (PM2.5 μg/m3. Demographic predictors of air pollution exposure included younger age, non-White race, lower education and middle class income. After adjustments, objective lung function measures (FEV1 and FEV1 to FVC ratio were the only cardiopulmonary health indicators significantly associated with chronic three-year annual averages of PM2.5. Among all non-asthmatics, a ten unit increase in estimated three year annual average PM2.5 exposure was significantly associated with lower forced expiratory volume (L in one second FEV1 (β = −0.40 μg/L; 95% CI −0.45, −0.06. Among all individuals, adverse perceptions of the neighborhood built environment did not appear to statistically moderate or mediate associations. However, stratified analysis did reveal significant associations between PM2.5 and lung function (FEV1 only among individuals with negative perceptions and increased reports of neighborhood stressors. These findings included individuals who

  16. Neighborhood Perceptions and Cumulative Impacts of Low Level Chronic Exposure to Fine Particular Matter (PM2.5) on Cardiopulmonary Health.

    Science.gov (United States)

    Malecki, Kristen M C; Schultz, Amy A; Bergmans, Rachel S

    2018-01-06

    Adverse perceptions of neighborhood safety, aesthetics and quality including access to resources can induce stress and may make individuals more sensitive to cardiopulmonary effects of air pollution exposure. Few studies have examined neighborhood perceptions as important and modifiable non-chemical stressors of the built environment that may exacerbate effects of air pollution on cardiopulmonary health outcomes, particularly among general population based cohorts. This study examined associations between low-level chronic exposure to fine particulate matter (PM 2.5 ) and cardiopulmonary health, and the potential mediating or modifying effects of adverse neighborhood perceptions. Using data from the Survey of the Health of Wisconsin (SHOW), 2230 non-asthmatic adults age 21-74 were included in the analyses. The overall goals of this study were to assess if individuals who experience stress from neighborhood environments in which they live were more sensitive to low levels of fine particular matter (PM 2.5 μg/m³). Demographic predictors of air pollution exposure included younger age, non-White race, lower education and middle class income. After adjustments, objective lung function measures (FEV1 and FEV1 to FVC ratio) were the only cardiopulmonary health indicators significantly associated with chronic three-year annual averages of PM 2.5 . Among all non-asthmatics, a ten unit increase in estimated three year annual average PM 2.5 exposure was significantly associated with lower forced expiratory volume (L) in one second FEV1 (β = -0.40 μg/L; 95% CI -0.45, -0.06). Among all individuals, adverse perceptions of the neighborhood built environment did not appear to statistically moderate or mediate associations. However, stratified analysis did reveal significant associations between PM 2.5 and lung function (FEV1) only among individuals with negative perceptions and increased reports of neighborhood stressors. These findings included individuals who felt their

  17. Boundary conditions for pathways, safety analysis and basic criteria for low-level radiation waste site selection

    International Nuclear Information System (INIS)

    Saverot, P.

    1994-01-01

    There are three successive periods in the life of a disposal facility: the operating period, the institutional control period and the unrestricted site access period. The purpose of safety analysis of the disposal facility is to ensure that the radiological impacts for each period in the life of the facility are acceptable under all circumstances. Founded on a deterministic approach, this analysis leads to a determination of the maximum quantity of each radionuclide present in the facility at the beginning of the institutional control period in order for the impacts to be considered acceptable. Safety analysis involves the calculation of the radiological impacts of a given radiological inventory under a selected scenario, from all plausible scenarios of radionuclide migration to the environment in both normal and accident conditions, and taking into account other specified variables. The calculation itself involves an assessment of the quantities of radionuclides that could be released to the environment under the specific scenario selected and following identified pathways, and a determination of the resultant exposure, both internal and external, to the public. An iterative approach is used in the performance of pathways analyses. If the pathways analyses result in unacceptable radiological impacts, either the radiological inventory of the site is reduced or barrier characteristics not previously factored into the analysis are taken into account. New pathways analyses are then performed until the results are within the acceptable range. Once accepted by the safety authorities, the radiological inventory becomes the radiological capacity, which is the approved quantities of specific radionuclides that may be disposed of at the site. The following elaborates on the boundary conditions used in safety analyses and describes the types of pathways analyses performed for a LLW disposal facility

  18. Exposure to non ionizing radiations

    International Nuclear Information System (INIS)

    Campanella, L.; Dragone, R.; Pastorelli, A.

    2001-01-01

    In the last years the exposure levels to electric, magnetic and electromagnetic fields of workers and citizens have dramatically increased due to the technological development as in the exemplar case of cellular phones. The object of this research concerns the biological evaluation of the risk from exposure to non ionizing radiations (NIR) by an opportunely designed biosensor based on immobilized Saccharomyces cerevisiae cells and by an amperometric transducer (Clark oxygen electrode). The results have been obtained by comparing the respiratory activities of exposed and not exposed yeast cells to NIR (at 900 MHz, frequency of the first generation cellular phones). The measurements have been performed by irradiation of the cells in a G-TEM chamber. The obtained results clearly show a decrease of the respiration activity of the irradiation cells in comparison with blank. This variation results to be proportional to the exposure time. Concerning reversibility of the damage it seems that the recovery of the initial conditions begins after 4 hours since the end of exposition and is complete within the following 48 hrs [it

  19. Adaptive response after low level irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pelevina, I I; Afanasjev, G G; JaGotlib, V; Tereschenko, D G; Tronov, V A; Serebrjany, A M [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Chemical Physics

    1996-02-01

    The experiments conducted on cultured HeLa (tissue culture) cells revealed that there is a limit of dose above which adaptive response was not observed and a limit of dose below which this response was not induced. The exposure of cells in the territories with elevated radiation background leads to genome instability which results in enhanced radiosensitivity. Investigations on the blood lymphocytes of people living in contaminated regions revealed that adaptive response was more significant in children whereas in adults there was slight increase. Acute irradiation serves as a tool revealing the changes that took place in DNA during chronic low level irradiations after Chernobyl disaster. (author).

  20. Chronic low-level arsenite exposure through drinking water increases blood pressure and promotes concentric left ventricular hypertrophy in female mice.

    Science.gov (United States)

    Sanchez-Soria, Pablo; Broka, Derrick; Monks, Sarah L; Camenisch, Todd D

    2012-04-01

    Cardiovascular disease is the leading cause of death in the United States and worldwide. High incidence of cardiovascular diseases has been linked to populations with elevated arsenic content in their drinking water. Although this correlation has been established in many epidemiological studies, a lack of experimental models to study mechanisms of arsenic-related cardiovascular pathogenesis has limited our understanding of how arsenic exposure predisposes for development of hypertension and increased cardiovascular mortality. Our studies show that mice chronically exposed to drinking water containing 100 parts per billion (ppb) sodium arsenite for 22 weeks show an increase in both systolic and diastolic blood pressure. Echocardiographic analyses as well as histological assessment show concentric left ventricular hypertrophy, a primary cardiac manifestation of chronic hypertension. Live imaging by echocardiography shows a 43% increase in left ventricular mass in arsenic-treated animals. Relative wall thickness (RWT) was calculated showing that all the arsenic-exposed animals show an RWT greater than 0.45, indicating concentric hypertrophy. Importantly, left ventricular hypertrophy, although often associated with chronic hypertension, is an independent risk factor for cardiovascular-related mortalities. These results suggest that chronic low-level arsenite exposure promotes the development of hypertension and the comorbidity of concentric hypertrophy.

  1. Radiation exposure of airplane crews. Exposure levels

    International Nuclear Information System (INIS)

    Bergau, L.

    1995-01-01

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

  2. Effects of low-level sarin and cyclosarin exposure and Gulf War Illness on brain structure and function: a study at 4T.

    Science.gov (United States)

    Chao, Linda L; Abadjian, Linda; Hlavin, Jennifer; Meyerhoff, Deiter J; Weiner, Michael W

    2011-12-01

    More than 100,000 US troops were potentially exposed to chemical warfare agents sarin (GB) and cyclosarin (GF) when an ammunition dump at Khamisiyah, Iraq was destroyed during the 1991 Persian Gulf War (GW). We previously found reduced total gray matter (GM) volume in 40 GW veterans with suspected GB/GF exposure relative to 40 matched, unexposed GW veterans on a 1.5T MR scanner. In this study, we reexamine the relationship between GB/GF exposure and volumetric measurements of gross neuroanatomical structures in a different cohort of GW veterans on a 4T MR scanner. Neuropsychological and magnetic resonance imaging (MRI) data from a cross sectional study on Gulf War Illness performed between 2005 and 2010 were used in this study. 4T MRI data were analyzed using automated image processing techniques that produced volumetric measurements of gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF). Binary comparisons of 64 GB/GF exposed veterans and 64 'matched', unexposed veterans revealed reduced GM (p=0.03) and WM (p=0.03) volumes in the exposed veterans. Behaviorally, exposed veterans committed more errors of omission (p=0.02) and tended to have slower responses (p=0.05) than unexposed veterans on the Continuous Performance Test (CPT), a measure sustained and selective attention. Regression analyses confirmed that GB/GF exposure status predicted GM (β=-0.11, p=0.02) and WM (β=-0.14, p=0.03) volumes, and number of CPT omission errors (β=0.22, p=0.02) over and above potentially confounding demographic, clinical, and psychosocial variables. There was no dose-response relationship between estimated levels of GB/GF exposure and brain volume. However, we did find an effect of Gulf War Illness/Chronic Multisymptom Illness on both GM and WM volume in the GB/GF exposed veterans. These findings confirm previous reports by our group and others of central nervous system pathology in GW veterans with suspected exposure to low levels of GB/GF two decades after the

  3. A new radiation exposure record system

    International Nuclear Information System (INIS)

    Lyon, M.; Berndt, V.L.; Trevino, G.W.; Oakley, B.M.

    1993-04-01

    The Hanford Radiological Records Program (HRRP) serves all Hanford contractors as the single repository for radiological exposure for all Hanford employees, subcontractors, and visitors. The program administers and preserves all Hanford radiation exposure records. The program also maintains a Radiation Protection Historical File which is a historical file of Hanford radiation protection and dosimetry procedures and practices. Several years ago DOE declared the existing UNIVAC mainframe computer obsolete and the existing Occupational Radiation Exposure (ORE) system was slated to be redeveloped. The new system named the Radiological Exposure (REX) System is described in this document

  4. Global environment and radiation exposure

    International Nuclear Information System (INIS)

    Okamoto, Kazuto

    1991-01-01

    The present status of investigation of acid rain, stratospheric ozone depletion and greenhouse effect and their relations to radiation exposure are reported. Soil acidification increases transfer rates of radioactivities to plants which increases the population dose. There are two types of ozone depletion, conventional type and ozone hole type and the latter is much more serious than the former. In the greenhouse effect, although there are large uncertainties both in theoretical and observational sides, present predictions about the global warming will not be very far from reality. Environmental effects are wide-ranging and serious. Radon and thoron exhalation rates are affected by the global warming. The influence of the greenhouse effect on ozone depletion is to suppress depletion for conventional type and enhance depletion for ozone hole type. (author) 65 refs

  5. Low level waste repositories

    International Nuclear Information System (INIS)

    Hill, P.R.H.; Wilson, M.A.

    1983-11-01

    Factors in selecting a site for low-level radioactive waste disposal are discussed. South Australia has used a former tailings dam in a remote, arid location as a llw repository. There are also low-level waste disposal procedures at the Olympic Dam copper/uranium project

  6. Radiation in the living environment: sources, exposure and effects

    International Nuclear Information System (INIS)

    Gupta, Rashi

    2013-01-01

    We are living in a milieu of radiations and continuously exposed to radiations from natural sources from conception to death. We are exposed to radiation from Sun and outer space, radioactive materials present in the earth, house we live in, buildings and workplace, food we eat and air we breath. Each flake of snow, grain of soil, drop of rain, a flower, and even each man in the street is a source of this radiation. Even our own bodies contain naturally occurring radioactive elements. The general belief is that the radiations are harmful and everybody is scared of the same. The cancer is the most important concern on account of exposure to Ionizing Radiation which is initiated by the damage to DNA. The level of exposure depends on the environmental and working conditions and may vary from low to moderate to high and depending on the same the exposed humans can be classified as general public, non nuclear workers (NNW) and nuclear workers (NW). Though, the LNT theory which is considered to be the radiation paradigm considers all radiation at all levels to be harmful and the -severity of the deleterious effect increases with the increase in dose, however, the available literature, data and reports (epidemiological and experimental) speaks otherwise particularly at low levels. The purpose of this paper is to address the question, whether the radiation is harmful at all levels or it is simply media hype and the truth is different, and to promote harmony with nature and to improve our quality of life with the knowledge that cancer mortality rates decrease following exposure to LLIR. Various sources of radiation exposure and the subsequent consequences will be discussed. (author)

  7. Low level postnatal methylmercury exposure in vivo alters developmental forms of short-term synaptic plasticity in the visual cortex of rat

    International Nuclear Information System (INIS)

    Dasari, Sameera; Yuan, Yukun

    2009-01-01

    Methylmercury (MeHg) has been previously shown to affect neurotransmitter release. Short-term synaptic plasticity (STP) is primarily related to changes in the probability of neurotransmitter release. To determine if MeHg affects STP development, we examined STP forms in the visual cortex of rat following in vivo MeHg exposure. Neonatal rats received 0 (0.9% NaCl), 0.75 or 1.5 mg/kg/day MeHg subcutaneously for 15 or 30 days beginning on postnatal day 5, after which visual cortical slices were prepared for field potential recordings. In slices prepared from rats treated with vehicle, field excitatory postsynaptic potentials (fEPSPs) evoked by paired-pulse stimulation at 20-200 ms inter-stimulus intervals showed a depression (PPD) of the second fEPSP (fEPSP2). PPD was also seen in slices prepared from rats after 15 day treatment with 0.75 or 1.5 mg/kg/day MeHg. However, longer duration treatment (30 days) with either dose of MeHg resulted in paired-pulse facilitation (PPF) of fEPSP2 in the majority of slices examined. PPF remained observable in slices prepared from animals in which MeHg exposure had been terminated for 30 days after completion of the initial 30 day MeHg treatment, whereas slices from control animals still showed PPD. MeHg did not cause any frequency- or region-preferential effect on STP. Manipulations of [Ca 2+ ] e or application of the GABA A receptor antagonist bicuculline could alter the strength and polarity of MeHg-induced changes in STP. Thus, these data suggest that low level postnatal MeHg exposure interferes with the developmental transformation of STP in the visual cortex, which is a long-lasting effect.

  8. 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)

  9. Radiation hormesis at occupational exposure

    International Nuclear Information System (INIS)

    Zaharieva, E.; Georgieva, R.

    2006-01-01

    Full text: The aim of our work was to find appropriate biomarkers applicable in molecular epidemiological surveys of occupationally exposed individuals to prove radiation hormesis. Blood samples were taken from a group of irradiated persons, and from a control group. For each worker we estimated a parameter arbitrarily called by us 'mean annual dose' as a quotient of cumulated dose and length of service. DNA repair synthesis in leucocytes before and after in vitro exposure to a challenge dose of 2.0 Gy gamma rays was determined by the level of incorporation of radioactively labeled nucleotides, level of DNA damage in lymphocytes was analyzed by single cell gel electrophoresis and level of lipid peroxidation processes was evaluated by malonedialdehyde concentration in blood plasma. A significant decrease of potentially lethal damage in persons with 'mean annual dose' lower or equal to 5 mSv/y was found, compared to the control group. The highest repair capacity after a challenging dose of 2.0 Gy gamma rays as well as a significant decrease in the level of oxidative stress determined in the blood plasma was evaluated for persons from the same group. The present investigation of occupationally exposed workers showed that annual doses no higher than twice the natural radiation background exert positive effects on DNA damage and repair, increase cellular resistance and decrease oxidative stress

  10. PET radiation exposure control for nurses

    International Nuclear Information System (INIS)

    Kawabata, Yumiko; Kikuta, Daisuke; Anzai, Taku

    2005-01-01

    Recently, the number of clinical PET centers is increasing all over Japan. For this reason, the monitoring and control of radiation exposure of employees, especially nurses, in PET-dedicated clinics and institutions are becoming very important issues for their health. We measured the radiation exposure doses of the nurses working at Nishidai Diagnostic Imaging Center, and analyzed the exposure data obtained from them. The exposure doses of the nurses were found to be 4.8 to 7.1 mSv between April 2003 and March 2004. We found that the nurses were mostly exposed to radiation when they had to have contact with patients received an FDG injection or they had trouble with the FDG automatic injection system. To keep radiation exposure of nurses to a minimum we reconfirmed that a proper application of the three principles of protection against radiation exposure was vital. (author)

  11. 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)

  12. Medical exposure and the effects of radiation

    International Nuclear Information System (INIS)

    Okuyama, Chio

    2011-01-01

    Radiation gives cracks to genes. The influence is divided into deterministic effect with a threshold value, and the stochastic effect (tumor and genetic effect) which increases according to the exposure amount. Although we are put to various non-artificial radiations, which we cannot be avoided, on the earth, the contamination by artificial radiation can be defended. Artificial radioactive exposure includes medical exposure and non-medical exposure for example by nuclear power plant. As to medical examinations using radiation, the inquiry about the radiation exposure is increasing after the occurrence of the first nuclear power plant disaster of Fukushima. While concern about non-medical radioactive exposure increases, the uneasiness to medical irradiation is also increasing. The dose limit by artificial radioactive exposure other than medical exposure is set up in order to prevent the influence on the health. While the dose limit of the public exposure is set to the lower value than the total dose of non-artificial exposure concerning of a safety margin for all people, the dose limit of medical exposure is not defined, since it is thought that medical irradiation has a benefit for those who receive irradiation. Making an effort to decrease the radiation dose in performing the best medical treatment is the responsibility with which we are burdened. (author)

  13. Leukaemia incidence in Welsh children linked with low level radiation-making sense of some erroneous results published in the media

    International Nuclear Information System (INIS)

    Steward, John A; White, Ceri; Reynolds, Shelagh

    2008-01-01

    A series of self-published epidemiological reports purporting to show a major excess risk of leukaemia in pre-school children living near the Irish Sea coast of Wales have been presented in the media as evidence of the harmful effects of low level radiation arising from Sellafield. The Welsh Cancer Intelligence and Surveillance Unit (WCISU), the body responsible for population-based cancer information in Wales, can provide insights into the validity of these reports, which appear to be a consequence of various mistakes. This raises important questions about the research governance of such reports and the communication of scientific findings via the mass media. Without suitable safeguards the media are in danger of promulgating misinformation

  14. Application of maximum radiation exposure values and monitoring of radiation exposure

    International Nuclear Information System (INIS)

    1996-01-01

    The guide presents the principles to be applied in calculating the equivalent dose and the effective dose, instructions on application of the maximum values for radiation exposure, and instruction on monitoring of radiation exposure. In addition, the measurable quantities to be used in monitoring the radiation exposure are presented. (2 refs.)

  15. Analytical study of the effects of the Low-Level Jet on moisture convergence and vertical motion fields at the Southern Great Plains Cloud and Radiation Testbed site

    Energy Technology Data Exchange (ETDEWEB)

    Bian, X.; Zhong, S.; Whiteman, C.D.; Stage, S.A. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-04-01

    The Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) is located in a region that is strongly affected by a prominent meteorological phenomenon--the Great Plains Low-Level Jet (LLJ). Observations have shown that the LLJ plays a vital role in spring and summertime cloud formation and precipitation over the Great Plains. An improved understanding of the LLJ characteristics and its impact on the environment is necessary for addressing the fundamental issue of development and testing of radiational transfer and cloud parameterization schemes for the general circulation models (GCMs) using data from the SGP CART site. A climatological analysis of the summertime LLJ over the SGP has been carried out using hourly observations from the National Oceanic and Atmospheric Administration (NOAA) Wind Profiler Demonstration Network and from the ARM June 1993 Intensive Observation Period (IOP). The hourly data provide an enhanced temporal and spatial resolution relative to earlier studies which used 6- and 12-hourly rawinsonde observations at fewer stations.

  16. The Screening of Genes Sensitive to Long-Term, Low-Level Microwave Exposure and Bioinformatic Analysis of Potential Correlations to Learning and Memory

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ya Li; LI Ying Xian; MA Hong Bo; LI Dong; LI Hai Liang; JIANG Rui; KAN Guang Han; YANG Zhen Zhong; HUANG Zeng Xin

    2015-01-01

    Objective To gain a better understanding of gene expression changes in the brain following microwave exposure in mice. This study hopes to reveal mechanisms contributing to microwave-induced learning and memory dysfunction. Methods Mice were exposed to whole body 2100 MHz microwaves with specific absorption rates (SARs) of 0.45 W/kg, 1.8 W/kg, and 3.6 W/kg for 1 hour daily for 8 weeks. Differentially expressing genes in the brains were screened using high-density oligonucleotide arrays, with genes showing more significant differences further confirmed by RT-PCR. Results The gene chip results demonstrated that 41 genes (0.45 W/kg group), 29 genes (1.8 W/kg group), and 219 genes (3.6 W/kg group) were differentially expressed. GO analysis revealed that these differentially expressed genes were primarily involved in metabolic processes, cellular metabolic processes, regulation of biological processes, macromolecular metabolic processes, biosynthetic processes, cellular protein metabolic processes, transport, developmental processes, cellular component organization, etc. KEGG pathway analysis showed that these genes are mainly involved in pathways related to ribosome, Alzheimer's disease, Parkinson's disease, long-term potentiation, Huntington's disease, and Neurotrophin signaling. Construction of a protein interaction network identified several important regulatory genes including synbindin (sbdn), Crystallin (CryaB), PPP1CA, Ywhaq, Psap, Psmb1, Pcbp2, etc., which play important roles in the processes of learning and memory. Conclusion Long-term, low-level microwave exposure may inhibit learning and memory by affecting protein and energy metabolic processes and signaling pathways relating to neurological functions or diseases.

  17. The Screening of Genes Sensitive to Long-Term, Low-Level Microwave Exposure and Bioinformatic Analysis of Potential Correlations to Learning and Memory.

    Science.gov (United States)

    Zhao, Ya Li; Li, Ying Xian; Ma, Hong Bo; Li, Dong; Li, Hai Liang; Jiang, Rui; Kan, Guang Han; Yang, Zhen Zhong; Huang, Zeng Xin

    2015-08-01

    To gain a better understanding of gene expression changes in the brain following microwave exposure in mice. This study hopes to reveal mechanisms contributing to microwave-induced learning and memory dysfunction. Mice were exposed to whole body 2100 MHz microwaves with specific absorption rates (SARs) of 0.45 W/kg, 1.8 W/kg, and 3.6 W/kg for 1 hour daily for 8 weeks. Differentially expressing genes in the brains were screened using high-density oligonucleotide arrays, with genes showing more significant differences further confirmed by RT-PCR. The gene chip results demonstrated that 41 genes (0.45 W/kg group), 29 genes (1.8 W/kg group), and 219 genes (3.6 W/kg group) were differentially expressed. GO analysis revealed that these differentially expressed genes were primarily involved in metabolic processes, cellular metabolic processes, regulation of biological processes, macromolecular metabolic processes, biosynthetic processes, cellular protein metabolic processes, transport, developmental processes, cellular component organization, etc. KEGG pathway analysis showed that these genes are mainly involved in pathways related to ribosome, Alzheimer's disease, Parkinson's disease, long-term potentiation, Huntington's disease, and Neurotrophin signaling. Construction of a protein interaction network identified several important regulatory genes including synbindin (sbdn), Crystallin (CryaB), PPP1CA, Ywhaq, Psap, Psmb1, Pcbp2, etc., which play important roles in the processes of learning and memorye. Long-term, low-level microwave exposure may inhibit learning and memory by affecting protein and energy metabolic processes and signaling pathways relating to neurological functions or diseases. Copyright © 2015 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  18. Low-level radioactive wastes: Their treatment, handling, disposal

    Energy Technology Data Exchange (ETDEWEB)

    Straub, Conrad P [Robert A. Taft Sanitary Engineering Center, Radiological Health Research Activities, Cincinnati, OH(United States)

    1964-07-01

    The release of low level wastes may result in some radiation exposure to man and his surroundings. This book describes techniques of handling, treatment, and disposal of low-level wastes aimed at keeping radiation exposure to a practicable minimum. In this context, wastes are considered low level if they are released into the environment without subsequent control. This book is concerned with practices relating only to continuous operations and not to accidental releases of radioactive materials. It is written by use for those interested in low level waste disposal problems and particularly for the health physicist concerned with these problems in the field. It should be helpful also to water and sewage works personnel concerned with the efficiency of water and sewage treatment processes for the removal of radioactive materials; the personnel engaged in design, construction, licensing, and operation of treatment facilities; and to student of nuclear technology. After an introduction the following areas are discussed: sources, quantities and composition of radioactive wastes; collection, sampling and measurement; direct discharge to the water, soil and air environment; air cleaning; removal of radioactivity by water-treatment processes and biological processes; treatment on site by chemical precipitation , ion exchange and absorption, electrodialysis, solvent extraction and other methods; treatment on site including evaporation and storage; handling and treatment of solid wastes; public health implications. Appendices include a glossary; standards for protection against radiation; federal radiation council radiation protection guidance for federal agencies; site selection criteria for nuclear energy facilities.

  19. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles

    Directory of Open Access Journals (Sweden)

    Dörr Harald

    2011-11-01

    Full Text Available Abstract Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed.

  20. DOE Occupational Radiation Exposure, 2001 report

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2001-12-31

    The goal of the U.S. Department of Energy (DOE) is to conduct its operations, including radiological, to ensure the safety and health of all DOE employees, contractors, and subcontractors. The DOE strives to maintain radiation exposures to its workers below administrative control levels and DOE limits and to further reduce these exposures to levels that are “As Low As Reasonably Achievable” (ALARA). The 2001 DOE Occupational Radiation Exposure Report provides a summary and analysis of the occupational radiation exposure received by individuals associated with DOE activities. The DOE mission includes stewardship of the nuclear weapons stockpile and the associated facilities, environmental restoration of DOE, and energy research.

  1. Ionizing radiation exposure of LDEF

    Science.gov (United States)

    Benton, E. V. (Editor); Heinrich, W. (Editor)

    1990-01-01

    The Long Duration Exposure Facility (LDEF) was launched into orbit by the Space Shuttle 'Challenger' mission 41C on 6 April 1984 and was deployed on 8 April 1984. The original altitude of the circular orbit was 258.5 nautical miles (479 km) with the orbital inclination being 28.5 degrees. The 21,500 lb NASA Langley Research Center satellite, having dimensions of some 30x14 ft was one of the largest payloads ever deployed by the Space Shuttle. LDEF carried 57 major experiments and remained in orbit five years and nine months (completing 32,422 orbits). It was retrieved by the Shuttle 'Columbia' on January 11, 1990. By that time, the LDEF orbit had decayed to the altitude of 175 nm (324 km). The experiments were mounted around the periphery of the LDEF on 86 trays and involved the representation of more than 200 investigators, 33 private companies, 21 universities, seven NASA centers, nine Department of Defense laboratories and eight foreign countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures, power and propulsion. The data contained in the LDEF mission represents an invaluable asset and one which is not likely to be duplicated in the foreseeable future. The data and the subsequent knowledge which will evolve from the analysis of the LDEF experiments will have a very important bearing on the design and construction of the Space Station Freedom and indeed on other long-term, near-earth orbital space missions. A list of the LDEF experiments according to experiment category and sponsor is given, as well as a list of experiments containing radiation detectors on LDEF including the LDEF experiment number, the title of the experiment, the principal investigator, and the type of radiation detectors carried by the specific experiment.

  2. Low Magnitude Occupational Radiation Exposures Are They Safe or Unsafe

    International Nuclear Information System (INIS)

    Ravichandran, R.

    2013-01-01

    Man has always been exposed to ionizing radiation from natural sources and background exposure varies with the locations. No deleterious effects have been uniquely correlated, either they are not produced at low levels of exposure or their frequency is too low to be statistically observable. Direct source of information on radiation hazards in man is obviously based on follow up of population groups exposed to certain levels of radiation. Harmful effects of ionizing radiations are traced to documented exposures; for radiologists during 1920 s and 30 s, miners exposed to airborne radioactivity, workers in the radium industry, follow-up data of Japanese nuclear bomb survivors of Hiroshima and Nagasaki, the Marshallese accident in 1954, and the victims of the limited number of accidents at nuclear installations including Chernobyl. Mostly these information are from situations involving higher doses and dose rates. Ionizing radiations have been used extensively on the peaceful applications of atomic energy in general and medical applications in particular have shown to outweigh benefits over the risks. Personnel, low magnitude of exposures are encountered during routine work in handling radiation sources. In the light of present knowledge there is need to reassess the quantum of actual risk instead of projected risk based on long time models. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) described models for dose-response relationships and micro-dosimetric arguments for defining low doses. The definition of low doses could also be based on direct observations in experimental or epidemiological studies. Through measurement of cell damage or death using human lymphocytes, linear and quadratic terms have been fitted the response and low doses have been judged to be 20-40 mSv. Data derived from epidemiological studies, mainly the atomic bomb survivors, suggests that for solid tumours and leukaemia, 200 mSv could be considered the

  3. Sources of radiation exposure - an overview

    International Nuclear Information System (INIS)

    Mason, G.C.

    1990-01-01

    Sources of radiation exposure are reviewed from the perspective of mining and milling of radioactive ores in Australia. The major sources of occupational and public exposure are identified and described, and exposures from mining and milling operations are discussed in the context of natural radiation sources and other sources arising from human activities. Most radiation exposure of humans comes from natural sources. About 80% of the world average of the effective dose equivalents received by individual people arises from natural radiation, with a further 15-20% coming from medical exposures*. Exposures results from human activities, such as mining and milling of radioactive ores, nuclear power generation, fallout from nuclear weapons testing and non-medical use of radioisotopes and X-rays, add less than 1% to the total. 9 refs., 4 tabs., 10 figs

  4. The analysis of radiation exposure of hospital radiation workers

    International Nuclear Information System (INIS)

    Jeong, Tae Sik; Shin, Byung Chul; Moon, Chang Woo; Cho, Yeong Duk; Lee, Yong Hwan; Yum, Ha Yong

    2000-01-01

    This investigation was performed in order to improve the health care of radiation workers, to predict a risk, to minimize the radiation exposure hazard to them and for them to realize radiation exposure danger when they work in radiation area in hospital. The documentations checked regularly for personal radiation exposure in four university hospitals in Pusan city in Korea between January 1, 1993 and December 31, 1997 were analyz ed. There were 458 persons in this documented but 111 persons who worked less then one year were excluded and only 347 persons were included in this study. The average of yearly radiation exposure of 347 persons was 1.52±1.35 mSv. Though it was less than 5OmSv, the limitaion of radiation in law but 125 (36%) people received higher radiation exposure than non-radiation workers. Radiation workers under 30 year old have received radiation exposure of mean 1.87±1.01 mSv/year, mean 1.22±0.69 mSv between 31 and 40 year old and mean 0.97±0.43 mSv/year over, 41year old (p<0.001). Men received mean 1.67±1.54 mSv/year were higher than women who received mean 1.13±0.61 mSv/year (p<0.01). Radiation exposure in the department of nuclear medicine department in spite of low energy sources is higher than other departments that use radiations in hospital (p<0.05). And the workers who received mean 3.69±1.81 mSv/year in parts of management of radiation sources and injection of sources to patient receive high radiation exposure in nuclear medicine department (0<0.01). In department of diagnostic radiology high radiation exposure is in barium enema rooms where workers received mean 3.74±1.74 mSv/year and other parts where they all use fluoroscopy such as angiography room of mean 1.17±0.35 mSv/year and upper gastrointestinal room of mean 1.74±1.34 mSv/year represented higher radiation exposure than average radiation exposure in diagnostic radiology (p<0.01). Doctors and radiation technologists received higher radiation exposure of each mean 1.75±1

  5. Primary water chemistry improvement for radiation exposure reduction at Japanese PWR Plants

    Energy Technology Data Exchange (ETDEWEB)

    Nishizawa, Eiichi [Omiya Technical Institute, Saitama-ken (Japan)

    1995-03-01

    Radiation exposure during the refueling outages at Japanese Pressurized Water Reactor (PWR) Plants has been gradually decreased through continuous efforts keeping the radiation dose rates at relatively low level. The improvement of primary water chemistry in respect to reduction of the radiation sources appears as one of the most important contributions to the achieved results and can be classified by the plant operation conditions as follows

  6. Application of maximum radiation exposure values and monitoring of radiation exposure

    International Nuclear Information System (INIS)

    1993-01-01

    According to the Section 32 of the Radiation Act (592/91) the Finnish Centre for Radiation and Nuclear Safety gives instructions concerning the monitoring of the radiation exposure and the application of the dose limits in Finland. The principles to be applied to calculating the equivalent and the effective doses are presented in the guide. Also the detailed instructions on the application of the maximum exposure values for the radiation work and for the natural radiation as well as the instructions on the monitoring of the exposures are given. Quantities and units for assessing radiation exposure are presented in the appendix of the guide

  7. Minimizing radiation exposure during percutaneous nephrolithotomy.

    Science.gov (United States)

    Chen, T T; Preminger, G M; Lipkin, M E

    2015-12-01

    Given the recent trends in growing per capita radiation dose from medical sources, there have been increasing concerns over patient radiation exposure. Patients with kidney stones undergoing percutaneous nephrolithotomy (PNL) are at particular risk for high radiation exposure. There exist several risk factors for increased radiation exposure during PNL which include high Body Mass Index, multiple access tracts, and increased stone burden. We herein review recent trends in radiation exposure, radiation exposure during PNL to both patients and urologists, and various approaches to reduce radiation exposure. We discuss incorporating the principles of As Low As reasonably Achievable (ALARA) into clinical practice and review imaging techniques such as ultrasound and air contrast to guide PNL access. Alternative surgical techniques and approaches to reducing radiation exposure, including retrograde intra-renal surgery, retrograde nephrostomy, endoscopic-guided PNL, and minimally invasive PNL, are also highlighted. It is important for urologists to be aware of these concepts and techniques when treating stone patients with PNL. The discussions outlined will assist urologists in providing patient counseling and high quality of care.

  8. Radiation exposure of uranium mill workers

    International Nuclear Information System (INIS)

    Jha, Giridhar; Saha, S.C.

    1982-01-01

    The uranium mill workers at Jaduguda were covered by a regular film badge service from 1969 onwards. Since the log normal plot is useful in interpreting occupational exposure, a statistical analysis of the radiation exposure data was attempted. Exposure data for each year has been plotted as cumulative percentage and worker's population with exposure levels in different class intervals. The plot for each of the year under investigation shows an occupational exposure distribution more or less consistent with the log normal distribution function. The analysis shows that more than 98% of radiation workers received less than 200 mrem (2 mSv). (author)

  9. Risk equivalent of exposure versus dose of radiation

    International Nuclear Information System (INIS)

    Bond, V.P.

    1986-01-01

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

  10. External radiation exposure of the public

    International Nuclear Information System (INIS)

    Mehl, J.

    1977-01-01

    Results of several ten thousand measurements on external radiation (outside buildings, in living rooms) are used for illustrating by isodose charts covering the total area of the Federal Republic of Germany the exposure of the public from external radiation originating from natural radiation of the environment. Results of calculations on external radiation exposure of the public due to releases of radioactivity in air from nuclear installations are used for illustrating by coloured isodose charts the exposure of the public in the plant site vicinity. From comparison of the exposure levels it becomes obvious that if exposure levels of several 10 mrem per year are considered to be of real concern to public health, control of natural radoactivity in the environment of man would require more attention than present and foreseeable releases of radioactivity in air from nuclear inst

  11. Low level waste disposal

    International Nuclear Information System (INIS)

    Barthoux, A.

    1985-01-01

    Final disposal of low level wastes has been carried out for 15 years on the shallow land disposal of the Manche in the north west of France. Final participant in the nuclear energy cycle, ANDRA has set up a new waste management system from the production center (organization of the waste collection) to the disposal site including the setting up of a transport network, the development of assessment, additional conditioning, interim storage, the management of the disposal center, records of the location and characteristics of the disposed wastes, site selection surveys for future disposals and a public information Department. 80 000 waste packages representing a volume of 20 000 m 3 are thus managed and disposed of each year on the shallow land disposal. The disposal of low level wastes is carried out according to their category and activity level: - in tumuli for very low level wastes, - in monoliths, a concrete structure, of the packaging does not provide enough protection against radioactivity [fr

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

    International Nuclear Information System (INIS)

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

    1998-01-01

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

  13. Monitoring occupational exposure to ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  14. Monitoring occupational exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Button, J.B.C.

    1997-01-01

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

  15. 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

  16. Radiation exposure and protection during angiography

    Energy Technology Data Exchange (ETDEWEB)

    Biazzi, L; Garbagna, P [Pavia Univ. (Italy)

    1979-05-01

    The authors describe the radiological techniques during angiography examinations in their hospital. For every technique they measured the radiation exposure and dose to the staff of doctors, assistants and nurses in their standard positions in the room and the radiation dose at various points on their bodies. The results are critically discussed and alternative protection devices are analysed, since there are many difficulties concerning the employ of usual radiation protection systems. Cardiologists, above all, are given some recommendations to reduce radiation exposure without prejudicing the exam results.

  17. Radiation exposure and protection during angiography

    International Nuclear Information System (INIS)

    Biazzi, L.; Garbagna, P.

    1979-01-01

    The authors describe the radiological techniques during angiography examinations in their hospital. For every technique they measured the radiation exposure and dose to the staff of doctors, assistants and nurses in their standard positions in the room and the radiation dose at various points on their bodies. The results are critically discussed and alternative protection devices are analysed, since there are many difficulties concerning the employ of usual radiation protection systems. Cardiologists, above all, are given some recomandations to reduce radiation exposure without prejudicing the exam results [fr

  18. Radiation exposure of children during cardiac catheterisation

    International Nuclear Information System (INIS)

    Popp, W.

    1979-01-01

    It is well known that in adults, cardiac catheterisation involves the highest possible radiation exposure for a single examination. The paper now investigates the radiation exposure in paediatric cardiac cathetrisations. Dosimeters attached to the children during the examination were used as well as phantom measurements under the conditions of cardiac catheterisation. With the aid of the phantom, also the total energy absorption during an examination procedure was determined. This value was estimated to be 80 mJ. In spite of the high individual exposure, the contribution to the population exposure is low due to the small number of cardiac catheterisations. (orig.) 891 AJ/orig. 892 MKO [de

  19. Exposure to background radiation in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, S.B. [Australian Radiation Lab., Melbourne, VIC (Australia)

    1997-12-31

    The average effective dose received by the Australian population is estimated to be {approx}1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m{sup -3} in Queensland to 16 Bq m{sup -3} in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year. 9 refs., 2 tabs., 4 figs.

  20. Exposure to background radiation in Australia

    International Nuclear Information System (INIS)

    Solomon, S.B.

    1997-01-01

    The average effective dose received by the Australian population is estimated to be ∼1.8 mSv / year. One half of this exposure arises from exposure from terrestrial radiation and cosmic rays, the remainder from radionuclides within the body and from inhalation of radon progeny. This paper reviews a number of research programmes carried out by the Australian Radiation Laboratory to study radiation exposure from natural background, particularly in the workplace and illustrate approaches to the quantification and management of exposure to natural radiation. The average radiation doses to the Australian population are relatively low; the average annual radon concentration ranged from 6 Bq m -3 in Queensland to 16 Bq m -3 in the Australian Capital Territory (ACT). Of more importance is the emerging issue of exposure to elevated background radiation in the workplace. Two situation are presented; the radiation exposure to air crues and show cave tour guides. Annual doses up to 3.8 mSv were estimated for international crew members while the highest estimate for show cave tour guides was 9 mSv per year

  1. Exposures to natural radiation in Switzerland

    International Nuclear Information System (INIS)

    Murith, Ch.; Gurtner, A.

    1999-01-01

    The exposure of human beings to ionising radiation from natural sources is a continuing and inescapable feature of life on earth. There are two main sources that contribute to this exposure: high-energy cosmic-ray particles incident to the earth's atmosphere and radioactive nuclides that originated in the earth's crust and are present everywhere in the environment, including human body itself. Both external and internal exposures to humans arise from these sources. Exposures to natural radiation sources in Switzerland and some of their variations are here summarised and the resulting effective doses are compared to those from man-made sources exposures. It results that the natural background exposures are more significant for the population than most exposures to man-made sources. (authors)

  2. Health consequences of ionizing radiation exposure

    International Nuclear Information System (INIS)

    Dalci, D.; Dorter, G.; Guclu, I.

    2004-01-01

    The increasing use of ionizing radiations all over the world induces an ever increasing interest of the professionals as well as of the whole society in health protection and the risk due to these practices. Shortly after its discovery, it was recognized that ionizing radiation can have adverse health effects and knowledge of its detrimental effects has accumulated. The fact that ionizing radiation produces biological damage has been known for many years. The biological effects of ionizing radiation for radiation protection considerations are grouped into two categories: The deterministic and the stochastic ones. Deterministic radiation effects can be clinically diagnosed in the exposed individual and occur when above a certain 'threshold' an appropriately high dose is absorbed in the tissues and organs to cause the death of a large number of cells and consequently to impair tissue or organ functions early after exposure. A clinically observable biological effect (Acute Radiation Syndromes, ARS) that occurs days to months after an acute radiation dose. ARS is a complex of acute injury manifestations that occur after a sufficiently large portion of a person's body is exposed to a high dose of ionizing radiation. Such irradiation initially injures all organs to some extent, but the timing and extent of the injury manifestations depend upon the type, rate, and dose of radiation received. Stochastic radiation effects are the chronic effects of radiation result from relatively low exposure levels delivered over long periods of time. These are sort of effects that might result from occupational exposure, or to the background exposure levels (includes radioactive pollution). Such late effects might be the development of malignant (cancerous) disease and of the hereditary consequences. These effects may be observed many years after the radiation exposure. There is a latent period between the initial radiation exposure and the development of the biological effect. In this

  3. Occupational radiation exposure and mortality study

    International Nuclear Information System (INIS)

    Coppock, E.; Dobson, D.; Fair, M.

    1992-06-01

    An epidemiological cohort study of some 300,000 Canadians enrolled in the National Dose Registry (NDR) is being undertaken to determine if there is excess cancer or other causes of mortality among those workers who are occupationally exposed to low levels of ionizing radiation. The results of this study may provide better understanding of the dose-response relationship for low doses of ionizing radiation and aid in the verification of risk estimates for radiation-induced cancer mortality. The Department of National Health and Welfare (DNHW) is responsible for the Registry; this study is being carried out by the Bureau of Radiation and Medical Devices (BRMD) with financial assistance and co-operation of various agencies including Statistics Canada and the Atomic Energy Control Board

  4. Electromagnetic radiation-2450 MHz exposure causes cognition ...

    Indian Academy of Sciences (India)

    83

    Electromagnetic radiation-2450 MHz exposure causes cognition deficit with mitochondrial. 1 ... decrease in levels of acetylcholine, and increase in activity of acetyl ...... neuronal apoptosis and cognitive disturbances in sevoflurane or propofol ...

  5. Control of radiation exposure (principles and methods)

    International Nuclear Information System (INIS)

    Agwimah, R. I.

    1999-01-01

    Biological risks are directly related to the tissue radiation dose, so it is very important to maintain personnel doses as low as realistically possible. This goal can be achieved by minimizing internal contamination and external exposure to radioactive sources

  6. Occupational radiation exposure in nuclear medicine

    International Nuclear Information System (INIS)

    Gloebel, B.; Muth, H.; Keller, K.D.; Hector, G.; Lehnen, H.

    1982-01-01

    In a large hospital (University Hospital, Homburg/Saar, 2000 beds) the use of radionuclides was determined with the aim of a balance of the radionuclide flow through the clinic and the resulting radiation exposure for the persons involved. (author)

  7. Radiation exposure and management of medical employes

    International Nuclear Information System (INIS)

    Yamamoto, Chiaki

    1981-01-01

    Medical employes handling medical radiation are increasing in recent years. In connection with the radiation exposure management, it was surveyed how much their cumulative exposure doses are and how many employes distribute in respective exposure levels. The medical employes surveyed are physicians, radiation technicians and nurses, working in the hospitals of educational institutions. The period of survey is every three years, from 1962 to 1977. For X-ray and ν-ray, respectively, the yearly cumulative exposure doses were measured by film badges, stepwise starting from below 500 mrem upward to over 5000 mrem; for the respective groups of employes, the percentage in each dose level was shown. The percentage in the level below 500 mrem was the largest in all groups, and in both X-ray and ν-ray, the percentages in higher levels decreased sharply to less than 7%. The exposure management has been improved in recent years. (J.P.N.)

  8. Radiation exposure and management of medical employes

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, C [Nagoya Univ. (Japan)

    1981-11-01

    Medical employes handling medical radiation are increasing in recent years. In connection with the radiation exposure management, it was surveyed how much their cumulative exposure doses are and how many employes distribute in respective exposure levels. The medical employes surveyed are physicians, radiation technicians and nurses, working in the hospitals of educational institutions. The period of survey is every three years, from 1962 to 1977. For X-ray and ..gamma..-ray, respectively, the yearly cumulative exposure doses were measured by film badges, stepwise starting from below 500 mrem upward to over 5000 mrem; for the respective groups of employes, the percentage in each dose level was shown. The percentage in the level below 500 mrem was the largest in all groups, and in both X-ray and ..gamma..-ray, the percentages in higher levels decreased sharply to less than 7%. The exposure management has been improved in recent years.

  9. Exposure of the orthopaedic surgeon to radiation

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Kiyonobu; Koga, Takamasa; Matsuzaki, Akio; Kido, Masaki; Satoh, Tetsunori [Fukuoka Univ. (Japan). Chikushi Hospital

    1995-09-01

    We monitored the amount of radiation received by surgeons and assistants during surgery carried out with fluoroscopic assistance. The radiation was monitored with the use of MYDOSE MINIX PDM107 made by Aloka Co. Over a one year period from Aug 20, 1992 to Aug 19, 1993, a study was undertaken to evaluate exposure of the groin level to radiation with or without use of the lead apron during 106 operation (Group-1). In another group, radiation was monitored at the breast and groin level outside of the lead apron during 39 operations (Group-2). In Group-1, the average exposure per person during one year was 46.0 {mu}SV and the average exposure for each procedure was 1.68 {mu}SV. The use of the lead apron affirmed its protective value; the average radiation dose at the groin level out-side of the apron was 9.11 {mu}SV, the measured dose beneath the apron 0.61 {mu}SV. The average dose of exposure to the head, breast at groin level outside of the lead apron, were 7.68 {mu}SV, 16.24 {mu}SV, 32.04 {mu}SV respectively. This study and review of the literature indicate that the total amount of radiation exposure during surgery done with fluoroscopic control remains well within maximum exposure limits. (author).

  10. Exposure of the orthopaedic surgeon to radiation

    International Nuclear Information System (INIS)

    Katoh, Kiyonobu; Koga, Takamasa; Matsuzaki, Akio; Kido, Masaki; Satoh, Tetsunori

    1995-01-01

    We monitored the amount of radiation received by surgeons and assistants during surgery carried out with fluoroscopic assistance. The radiation was monitored with the use of MYDOSE MINIX PDM107 made by Aloka Co. Over a one year period from Aug 20, 1992 to Aug 19, 1993, a study was undertaken to evaluate exposure of the groin level to radiation with or without use of the lead apron during 106 operation (Group-1). In another group, radiation was monitored at the breast and groin level outside of the lead apron during 39 operations (Group-2). In Group-1, the average exposure per person during one year was 46.0 μSV and the average exposure for each procedure was 1.68 μSV. The use of the lead apron affirmed its protective value; the average radiation dose at the groin level out-side of the apron was 9.11 μSV, the measured dose beneath the apron 0.61 μSV. The average dose of exposure to the head, breast at groin level outside of the lead apron, were 7.68 μSV, 16.24 μSV, 32.04 μSV respectively. This study and review of the literature indicate that the total amount of radiation exposure during surgery done with fluoroscopic control remains well within maximum exposure limits. (author)

  11. 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

  12. Natural background radiation exposures world-wide

    International Nuclear Information System (INIS)

    Bennett, B.G.

    1993-01-01

    The average radiation dose to the world's population from natural radiation sources has been assessed by UNSCEAR to be 2.4 mSv per year. The components of this exposure, methods of evaluation and, in particular, the variations in the natural background levels are presented in this paper. Exposures to cosmic radiation range from 0.26 mSv per year at sea level to 20 times more at an altitude of 6000 m. Exposures to cosmogenic radionuclides ( 3 H, 14 C) are relatively insignificant and little variable. The terrestrial radionuclides 40 K, 238 U, and 232 Th and the decay products of the latter two constitute the remainder of the natural radiation exposure. Wide variations in exposure occur for these components, particularly for radon and its decay products, which can accumulate to relatively high levels indoors. Unusually high exposures to uranium and thorium series radionuclides characterize the high natural background areas which occur in several localized regions in the world. Extreme values in natural radiation exposures have been estimated to range up to 100 times the average values. (author). 15 refs, 3 tabs

  13. Cosmic radiation exposure to airline flight passenger

    International Nuclear Information System (INIS)

    Momose, Mitsuhiro

    2000-01-01

    At the high altitudes, airline flight passengers can be exposed to some levels of cosmic radiation. The purpose of this study was to quantify this radiation exposure. Cosmic radiation was measured during 5 flights using a personal dosimeter (PDM-102, Aloka). Cosmic radiation equivalent dose rates ranged from 0.7 to 1.43 microsieverts per hour, the average rate was 1.08. For the passenger who travels only occasionally, the cosmic radiation levels are well below occupational limits, and the risks are extremely small. (author)

  14. Cosmic radiation exposure to airline flight passenger

    Energy Technology Data Exchange (ETDEWEB)

    Momose, Mitsuhiro [Shinshu Univ., Matsumoto, Nagano (Japan). School of Medicine

    2000-08-01

    At the high altitudes, airline flight passengers can be exposed to some levels of cosmic radiation. The purpose of this study was to quantify this radiation exposure. Cosmic radiation was measured during 5 flights using a personal dosimeter (PDM-102, Aloka). Cosmic radiation equivalent dose rates ranged from 0.7 to 1.43 microsieverts per hour, the average rate was 1.08. For the passenger who travels only occasionally, the cosmic radiation levels are well below occupational limits, and the risks are extremely small. (author)

  15. 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.

  16. Valuing the radiation detriment of occupational exposure

    International Nuclear Information System (INIS)

    Robb, J.D.; Crick, M.J.

    1989-01-01

    The implications of changes in the radiation risk estimates on the valuation of radiation detriment for use in cost-benefit analysis are being considered at the National Radiological Protection Board. This paper discusses the pertinent factors that are currently being considered for further investigation. An example of relevance to occupational exposure is detailed. (author)

  17. 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)

  18. Non-occupational exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Snihs, J.O.

    1985-01-01

    An overview of non-occupational exposure is presented. The special problems in connection with assessments of collective doses (time, geographical extension, cut-off, uncertainties) are discussed. Examples of methods and principles for monitoring and dose assessments used for various sources of radiation are given and data on public exposure are presented and discussed. (author)

  19. The radiation resistance and cobalt biosorption activity of yeast strains isolated from the Lanyu low-level radioactive waste repository in Taiwan.

    Science.gov (United States)

    Li, Chia-Chin; Chung, Hsiao-Ping; Wen, Hsiao-Wei; Chang, Ching-Tu; Wang, Ya-Ting; Chou, Fong-In

    2015-08-01

    The ubiquitous nature of microbes has made them the pioneers in radionuclides adsorption and transport. In this study, the radiation resistance and nuclide biosorption capacity of microbes isolated from the Lanyu low-level radioactive waste (LLRW) repository in Taiwan was assessed, the evaluation of the possibility of using the isolated strain as biosorbents for (60)Co and Co (II) from contaminated aqueous solution and the potential impact on radionuclides release. The microbial content of solidified waste and broken fragments of containers at the Lanyu LLRW repository reached 10(5) CFU/g. Two yeast strains, Candida guilliermondii (CT1) and Rhodotorula calyptogenae (RT1) were isolated. The radiation dose necessary to reduce the microbial count by one log cycle of CT1 and RT1 was 2.1 and 0.8 kGy, respectively. Both CT1 and RT1 can grow under a radiation field with dose rate of 6.8 Gy/h, about 100 times higher than that on the surface of the LLRW container in Lanyu repository. CT1 and RT1 had the maximum (60)Co biosorption efficiency of 99.7 ± 0.1% and 98.3 ± 0.2%, respectively in (60)Co aqueous solution (700 Bq/mL), and the (60)Co could stably retained for more than 30 days in CT 1. Nearly all of the Co was absorbed and reached equilibrium within 1 h by CT1 and RT1 in the 10 μg/g Co (II) aqueous solution. Biosorption efficiency test showed almost all of the Co (II) was adsorbed by CT1 in 20 μg/g Co (II) aqueous solution, the efficiency of biosorption by RT1 in 10 μg/g of Co (II) was lower. The maximum Co (II) sorption capacity of CT1 and RT1 was 5324.0 ± 349.0 μg/g (dry wt) and 3737.6 ± 86.5 μg/g (dry wt), respectively, in the 20 μg/g Co (II) aqueous solution. Experimental results show that microbial activity was high in the Lanyu LLRW repository in Taiwan. Two isolated yeast strains, CT1 and RT1 have high potential for use as biosorbents for (60)Co and Co (II) from contaminated aqueous solution, on the other hand, but may have the

  20. 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

  1. Applied physics of external radiation exposure dosimetry and radiation protection

    CERN Document Server

    Antoni, Rodolphe

    2017-01-01

    This book describes the interaction of living matter with photons, neutrons, charged particles, electrons and ions. The authors are specialists in the field of radiation protection. The book synthesizes many years of experiments with external radiation exposure in the fields of dosimetry and radiation shielding in medical, industrial and research fields. It presents the basic physical concepts including dosimetry and offers a number of tools to be used by students, engineers and technicians to assess the radiological risk and the means to avoid them by calculating the appropriate shields. The theory of radiation interaction in matter is presented together with empirical formulas and abacus. Numerous numerical applications are treated to illustrate the different topics. The state of the art in radiation protection and dosimetry is presented in detail, especially in the field of simulation codes for external exposure to radiation, medical projects and advanced research. Moreover, important data spread in differ...

  2. Radiation exposure modeling and project schedule visualization

    International Nuclear Information System (INIS)

    Jaquish, W.R.; Enderlin, V.R.

    1995-10-01

    This paper discusses two applications using IGRIP (Interactive Graphical Robot Instruction Program) to assist environmental remediation efforts at the Department of Energy (DOE) Hanford Site. In the first application, IGRIP is used to calculate the estimated radiation exposure to workers conducting tasks in radiation environments. In the second, IGRIP is used as a configuration management tool to detect interferences between equipment and personnel work areas for multiple projects occurring simultaneously in one area. Both of these applications have the capability to reduce environmental remediation costs by reducing personnel radiation exposure and by providing a method to effectively manage multiple projects in a single facility

  3. Occupational radiation exposures in Canada - 1982

    International Nuclear Information System (INIS)

    Fujimoto, K.R.; Wilson, J.A.; Ashmore, J.P.; Grogan, D.

    1983-12-01

    This report is the fifth in a series of annual reports in Occupational Radiation Exposures in Canada. The data is derived from the Radiation Protection Bureau's National Dose Registry which contains dose records for radiation workers. The report presents average yearly doses by region and occupational category, dose distributions, and variation of average doses with time. Statistical data concerning investigations of high exposures reported by the National Dosimetry Services are included, and individual cases are briefly summarized where the maximum permissible dose is exceeded

  4. Occupational radiation exposures in Canada - 1980

    International Nuclear Information System (INIS)

    Ashmore, J.P.; Fujimoto, K.R.; Wilson, J.A.; Grogan, D.

    1981-08-01

    This report is the third in a series of annual reports on Occupational Radiation Exposures in Canada. The data is derived from the Radiation Protection Bureau's National Dose Registry which includes dose records for radiation workers. The report presents average yearly doses by region and occupational category, dose distributions, and variation of average doses with time. Statistical data concerning investigations of high exposures reported by the National Dosimetry Services are included and individual cases are briefly summarized where the maximum permissible dose is exceeded. The decrease in the overall average doses established over the last 20 years appears to be changing. In some occupational categories a consistent upward trend is observed

  5. Eighth annual occupational radiation exposure report, 1975

    International Nuclear Information System (INIS)

    Brooks, B.G.

    1976-10-01

    This is a report by the U.S. Nuclear Regulatory Commission on the operation of the Commission's centralized repository of personnel occupational radiation exposure information. Annual reports were received from 387 covered licensees indicating that some 78,713 individuals, having an average exposure of 0.36 rems, were monitored for exposure to radiation during 1975 and that 21,601 individuals terminated their employment or work assignment with covered licensees in 1975. The number of personnel overexposures reported in 1975 decreased from previous years. The most significant overexposures which occurred in 1975 are summarized

  6. Long-term effects of prenatal exposure to low levels of gamma rays on open-field activity in male mice

    International Nuclear Information System (INIS)

    Minamisawa, Takeru; Hirokaga, Kouichi

    1995-01-01

    The open-field activity of first-generation (F 1 ) hybrid male C57BL/6 x C3H mice irradiated with γ rays on day 14 of gestation was studied at the following ages: 6-7 months (young), 12-13 months (adult) and 19-20 months (old). Doses were 0.5 Gy or 1.0 Gy. Open-field activity was recorded with a camera. The camera output signal was recorded every second through an A/D converter to a personal computer. The field was divided into 25 8-cm 2 units. All recordings were continuous for 60 min. The walking speed of the 1.0-Gy group recorded at 19-20 months was higher than that for the comparably aged control group. The time which the irradiated group, recorded at 19-20 months, spent in the corner fields was high in comparison with the control group at the same age. Conversely, the time spent by the irradiated group in the middle fields when recorded at 19-20 months was shorter than in the comparably aged control group. No effect of radiation was shown for any of the behaviors observed and recorded at 6-7 and 12-13 months. The results demonstrate that such exposure to γ rays on day 14 of gestation results in behavioral changes which occur at 19-20 but not at 6-7 or 12-13 months. 10 refs. 2 figs., 1 tab

  7. Long-term effects of prenatal exposure to low levels of gamma rays on open-field activity in male mice.

    Science.gov (United States)

    Minamisawa, T; Hirokaga, K

    1995-11-01

    The open-field activity of first-generation (F1) hybrid male C57BL/6 x C3H mice irradiated with gamma rays on day 14 of gestation was studied at the following ages: 6-7 months (young), 12-13 months (adult) and 19-20 months (old). Doses were 0.5 Gy or 1.0 Gy. Open-field activity was recorded with a camera. The camera output signal was recorded every second through an A/D converter to a personal computer. The field was divided into 25 8-cm2 units. All recordings were continuous for 60 min. The walking speed of the 1.0-Gy group recorded at 19-20 months was higher than that for the comparably aged control group. The time which the irradiated group, recorded at 19-20 months, spent in the corner fields was high in comparison with the control group at the same age. Conversely, the time spent by the irradiated group in the middle fields when recorded at 19-20 months was shorter than in the comparably aged control group. No effect of radiation was shown for any of the behaviors observed and recorded at 6-7 and 12-13 months. The results demonstrate that such exposure to gamma rays on day 14 of gestation results in behavioral changes which occur at 19-20 months but not at 6-7 or 12-13 months.

  8. CHOLINERGIC AND NORADRENERGIC MODULATION OF LONG-TERM EXPLICIT MEMORY ARE ALTERED BY CHRONIC LOW-LEVEL LEAD EXPOSURE. (U915393)

    Science.gov (United States)

    Recent evidence suggests that septohippocampal cholinergic activity is suppressed in rats exposed to low levels of lead (Pb). As a result, noradrenergic activity may be elevated due to compensatory sympathetic sprouting. Therefore, the goals of this study were to (a) determine...

  9. Integrated occupational radiation exposure information system

    International Nuclear Information System (INIS)

    Hunt, H.W.

    1983-06-01

    The integrated (Occupational Radiation Exposure) data base information system has many advantages. Radiation exposure information is available to operating management in a more timely manner and in a more flexible mode. The ORE system has permitted the integration of scattered files and data to be stored in a more cost-effective method that permits easy and simultaneous access by a variety of users with different data needs. The external storage needs of the radiation exposure source documents are several orders of magnitude less through the use of the computer assisted retrieval techniques employed in the ORE system. Groundwork is being layed to automate the historical files, which are maintained to help describe the radiation protection programs and policies at any one point in time. The file unit will be microfilmed for topical indexing on the ORE data base

  10. Atmospheric Ionizing Radiation and Human Exposure

    Science.gov (United States)

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

    2005-01-01

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

  11. Atmospheric Ionizing Radiation and Human Exposure

    Science.gov (United States)

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

    2004-01-01

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

  12. Liability for radiation exposure from the viewpoint of the practitioner

    International Nuclear Information System (INIS)

    Collins, V.P.

    1980-01-01

    A mounting concern for environmental radiation hazards spills over into an increasing fear and mistrust of medical uses of radiation. This situation sets the stage for an increasing recourse to litigation particularly in the area of low level radiation exposure. Knowledge that the initial exposure is unfelt, that the injury may be long-delayed in appearance, and that the injury is nonspecific, only feeds the apprehension of the public. Over centuries of experience, courts have evolved rules of law for the decision-making process that call for definitions of proof and truth that differ from those of science. A series of legal cases involving radiation injuries are presented to demonstrate the evolution of applicable legal mechanisms. The earliest cases leaned to strict application of the elements of negligence, proof of injury, causation and fault. These requirements relaxed gradually to minimize the burden of proof of the injured plaintiff. Elements of anxiety were recognized as compensable. A requirement of informed consent replaced a need to prove negligence. The element of fault, becoming increasingly difficult to prove with the complexity of delayed effects and statistics of probability, is dropped in the doctrine of product liability or strict liability. This may be a necessary solution to allow compensation of an innocent injured party where fault may be impossible to prove and where, in fact, it may not exist

  13. Routine medicare and radiation exposure. Introductory remarks

    International Nuclear Information System (INIS)

    Hirata, Hideki; Saito, Tsutomu

    2013-01-01

    As an introduction of the title series, outlines of radiation in physics, chemistry, biochemistry, biological effect and protection are explained from the clinical doctors' aspect of routine medicare, and of radiation exposure in which people's interest is raised after the Fukushima Nuclear Power Plant Accident in 2011. For physics, ionizing effects of radiation are described in relation to its quantum energy transfer and its medical utilization like imaging and radiotherapy. Then mentioned in brief is the radiation from elements consisting of human body, cosmic ray and background radiation from the earth, with reference to natural and standardized limits of exposure doses. Radiations from 226 Rn and 40 K are explained as an instance of environmental natural sources together with the concepts of radioactive decay series/scheme, of internal exposure, of hazard like double strand break (DSB) and of medical use such as boron neutron capture therapy (BNCT). For an artifact radiation source, shown are fission products of 235 U by neutron, first yielded in 1945. Evidence of evolution in biochemical repair mechanisms of DSB is explained with a comparison of irradiated drosophila mutation where linear non-threshold (LNT) hypothesis is proposed, and human non-homologous end joining and homologous recombination. Historical process of occupational, medical, public exposures and their protection is finally described from the discovery of X-ray in 1895 to the first ICRP publication in 1958 via the A-bomb explosion in 1945. (T.T.)

  14. An assessment of the potential radiation exposure from residual radioactivity in scrap metal for recycling

    International Nuclear Information System (INIS)

    Lee, Sang Yoon; Lee, Kun Jai

    1997-01-01

    With current waste monitoring technology it is reasonable to assume that much of the material designated as low level waste (LLW), generated within nuclear facilities, is in fact uncontaminated. This may include operational wastes, metal and rubble, office waste and discrete items from decommissioning or decontamination operations. Materials that contain only trivial quantities of radionuclides could realistically be exempted or released from regulatory control for recycle or reuse. A criterion for uncontrolled disposal of low-level radioactive contaminated waste is that the radiation exposure of the public and of each individual caused by this disposal is so low that radiation protection measures need not be taken. The International Atomic Energy Agency (IAEA) suggests an annual effective doses of 10 μ Sv as a limit for the individual radiation dose. In 1990, new recommendation on radiation protection standards was developed by International Commission on Radiological Protection (ICRP) to take into account new biological information related to the detriment associated with radiation exposure. Adoption of these recommendations necessitated a revision of the Commission's secondary limits contained in Publication 30, Parts 1 ∼ 4. This study summarized the potential radiation exposure from valuable scrap metal considered to uncontrolled recycle by new ICRP recommendations. Potential exposure pathways to people following were analyzed and relevant models developed. Finally, concentrations leading to an individual dose of 10 μ Sv/yr were calculated for 14 key radionuclides. These potential radiation exposures are compared with the results of an IAEA study. 12 refs., 6 tabs., figs

  15. Indoor exposure to natural radiation in Denmark

    International Nuclear Information System (INIS)

    Ulbak, K.; Stenum, B.; Soerensen, A.; Majborn, B.; Boetter-Jensen, L.; Nielsen, S.P.

    1988-01-01

    Assessment of the exposures to the Danish population from different natural radiation sources including building materials, drinking water, fly ash etc. has been performed from 1975 and up till now. In 1987 a comprehensive nationwide investigation of the gamma exposures and radon levels in 500 randomly selected Danish dwellings will be concluded by the National Institute of Radiation Hygiene. At the same time the Danish authorities will publish a control strategy for limiting the exposure of the Danish population from natural sources, especially from radon daughter exposure in dwellings. The presentation will outline the main results of the nationwide survey in Danish dwellings together with the main principles behind and the consequences of the initiated control strategy for limiting the exposures from natural radioactive sources

  16. Human exposure to ultraviolet radiation

    International Nuclear Information System (INIS)

    Bernhardt, J.H.; Matthes, R.

    1987-01-01

    Ultraviolet radiation is that part of the electromagnetic spectrum located between the softest ionizing radiation and visible radiation. The lower limit of 100 nm is equivalent to photon energies of 12.4 eV, which corresponds approximately to the limit for the production of ionization in biologically important materials. A historical subdividing of the UV-region takes some of the biological effects into account. In this arrangement the range 400-315 nm, the so-called black light region, is called UV-A. In this wavelength region, fluorescence can be induced in many substances. UV-B covers the range 315-280 nm (the skin erythemal region). Most of the biologically active and potentially harmful UV from the sun reaching the surface of the earth is part of this spectral region. UV-C includes the radiation of wavelengths less than 280 nm (the germicidal region). It should be noted that this classification is somewhat arbitrary, and today it is more usual to evaluate the biological effectiveness of the whole UV-range from 200 to 400 nm

  17. 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)

  18. Investigation of genomic instability by assay of DNA fingerprint from the offspring of male mice exposed to chronic low-level γ-radiation

    International Nuclear Information System (INIS)

    Bezlepkin, V.G.; Vasil'eva, G.V.; Lomaeva, M.G.; Sirota, N.P.; Gaziev, A.I.

    2000-01-01

    By polymerase chain reaction with arbitrary primer (AP-PCR), the possibility of transmission of genome instability to somatic cells of the offspring (F 1 generation) from male parents of mice exposed to chronic low-dose γ-radiation was studied. Male mice 15 days after exposure to 10-50 cGy were mated with unirradiated females. Biopsies were taken from tale tips of two month-old mice progeny for DNA separation. Primer in the AP-PCR was 20-mer oligonucleotide flanking the micro-satellite locus Atplb2 on chromosome 11 of the mouse. Comparative analysis of individual fingerprints of AP-PCR products on DNA-templates from the offspring of irradiated and unirradiated male mice revealed an increased variability of micro-satellite-associated sequences in the genome of the offspring of males exposed to 25 and 50 cGy. DNA-fingerprints of the offspring of male mice exposed to chronic irradiation doses 10 and 25 cGy. 15 days before fertilization (at the post-meiotic stage of spermatogenesis) showed an increased frequency of non-parent bands. Result of the study point to the possibility of transmission to the offspring somatic cells of changes increasing genome instability from male parents exposed to chronic low-dose radiation prior to fertilization [ru

  19. Radiation exposure from civil aviation

    International Nuclear Information System (INIS)

    Schalch, D.

    1994-01-01

    The question as to whether civil air crews and frequent air passengers ought to be classified among the group of occupationally exposed persons has in principle been decided by the recommendations adopted by the ICRP, the competent bodies of the EU, and national authorities. Measurements for more information on the radiation fields involved are planned. The German Radiation Protection Office (BfS) recently published a statement on dose commitments, assuming a maximum annual dose of approx. 8 mS