WorldWideScience

Sample records for agents ionising radiation

  1. Ionising radiation

    International Nuclear Information System (INIS)

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

  2. Ionising radiations regulations 1985

    International Nuclear Information System (INIS)

    The (UK) Ionising Radiations Regulations 1985 come into force on 1.1.86 with supporting Approved Code of Practice. They are discussed under the headings: introduction; notifications to start work with ionising radiations; dose limitation (ALARP -as low as reasonably practicable); designation of controlled and supervised areas; Radiation Protection Advisers to be appointed by employers; Local Rules; Radiation Protection Supervisors to be appointed by employers from among employees; instruction and training; dosimetry and medical surveillance; control of radioactive substances; radiation monitoring; assessment of hazards; articles and equipment. (U.K.)

  3. Pulvinic synthesis and evaluation of pulvinic derivatives like agents of protection against radiation ionising

    International Nuclear Information System (INIS)

    This work is devoted to the by-products preparation of mushrooms pigments, the pulvinic acids then to the evaluation of their oxidizing properties in the aim to find new compounds susceptible to be employed as protective drugs against ionizing radiation. An efficient method of symmetric pulvinic acids has been finalized. It is based on a double condensation of silylated cetenes acetals with oxalyl chloride. The treatment of the products got by D.B.U. leads to esters of corresponding pulvinic acids that are then saponified. The oxidizing properties have been studied. Then, the interaction between the pulvinic by-products and DNA are studied. Finally, the evaluation of radioprotective properties of the different synthesized compounds on different models (bacteria, eucaryotes cell and animal) is presented. (N.C.)

  4. Health Service use of ionising radiations: Guidance

    International Nuclear Information System (INIS)

    This booklet gives outline guidance on the use of ionising radiations in the Health Service in the United Kingdom. Extensive reference is made to documents where more detailed information may be found. The guidance covers general advice on the medical use of ionising radiations, statutory requirements, and guidance on selected Health Service issues such as patient identification procedures, information management systems, deviations from prescribed radiation dose, imaging and radiotherapy. (57 references) (U.K.)

  5. Protection of outside workers against ionising radiation

    International Nuclear Information System (INIS)

    This HSE information sheet is aimed at employers of outside workers, managers of contractors, health physics staff, appointed safety representatives, radiation protection advisers (RPA) and radiation protection supervisors (RIPS), employers in control of controlled areas which outside workers may enter, and outside workers themselves. This guidance supplements that in the Approved Code of Practice (ACOP) supporting the Ionising Radiations Regulations 1999 (IRR99) available from HSE Books, ISBN 0 7176 1746 7. IRR99 include provisions for outside workers that were previously required under the Ionising Radiations (Outside Workers) Regulations 1993 (OWR), which were revoked when IRR99 came into effect

  6. Thyroid cancer following exposure to ionising radiation

    International Nuclear Information System (INIS)

    Exposure to ionising radiations during childhood increases the risk of thyroid cancer. Similar risk factors have been found after external radiation exposure or internal contamination with radioactive iodine isotopes. In case of contamination with radio-iodines, administration of potassium iodide can prevent thyroid irradiation. (authors)

  7. Impact assessment of ionising radiation on wildlife

    International Nuclear Information System (INIS)

    This R and D project was commissioned by the Environment Agency and English Nature in January 2001 to provide up-to-date information on the impacts of ionising radiation on wildlife, upon which a robust assessment approach may be developed. This approach will also feed into the European Commission funded project 'Framework for Assessment of Environmental Impact' (FASSET), due to complete in October 2003. This report describes the behaviour and transport of radionuclides in the environment, considers the impact of ionising radiation on wildlife, and makes recommendations on an approach for the impact assessment of ionising radiation on wildlife for England and Wales. The assessment approach focuses on three ecosystems representative of those considered potentially most at risk from the impact of authorised radioactive discharges, namely a coastal grassland (terrestrial ecosystem); estuarine and freshwater ecosystems. The likely scale of the impact on wildlife is also assessed in light of a preliminary analysis based on this assessment approach. The aims of the report are: to summarise the latest research on the behaviour, transfer and impact of ionising radiation effects on wildlife; an outline and review of the relevant European and national legislation which has impacts on the requirements for assessments of the impact of ionising radiation on wildlife in the UK; to consider the role of regulatory bodies in assessing the impact of ionising radiation on wildlife with respect to England and Wales; to make recommendations on the relative biological effectiveness of different types of radiation with respect to wildlife; and to recommend an approach to assess the impacts to wildlife from ionising radiation from authorised discharges in England and Wales, with spreadsheets to support the methodology. The report demonstrates the behaviour and transfer of radionuclides in a number of different ecosystem types. Particular emphasis is placed on exposure pathways in those

  8. Risk from deterministic effects of ionising radiation

    International Nuclear Information System (INIS)

    This publication provides a review of information for assessing deterministic effects on human health likely to arise from serious overexposure to ionising radiation. It updates information in previous Board publications NRPB-R226 and NRPB-M246. It constitutes a parallel document to Documents of the NRPB, 4, No. 4 (1993), which deals with stochastic effects. These two documents, together with Documents of the NRPB, 6, No. 1 (1995), which deals specifically with stochastic risk at low dose rates, give the current Board view on all health consequences of exposure to ionising radiation. Little new primary information on deterministic effects has become available in recent years. However, advances in techniques for data analysis have been made and are incorporated in the present report. These are presented in a form suitable for use in modelling the consequences to populations of serious radiological incidents. (author)

  9. Luminescent detectors of ionising radiation

    International Nuclear Information System (INIS)

    At present in slow neutron imaging an active layer of an imaging plate IP contains a mixture of storage phosphors, usually BaFBr:Eu2+ used for imaging of X-rays, and a neutron converter material, usually Gd2O3, LiF. A novel Li-containing luminescent material perspective for a direct neutron conversion and storage is discussed. Irradiation of LiBaF3 crystals results in generation of Frenkel defect pairs and creation of F-type centres responsible for three absorption bands in UV-and visible spectral region. Because photo-stimulation in each of these absorption bands leads to bleaching of induced absorption, the F-type colour centres are convenient for storage of radiation dose. Photo-stimulated decay of F-centres causes recombination luminescence of impurity centres. Thermoactivated decay of F-type centres is governed by ionic process. The thermal stability of F-centres at RT and consequent material storage characteristics can be improved by doping of the LiBaF3 with heterovalent oxygen impurities. The obtained radiation energy storage, photo- and thermostimulated read-out characteristics justify that LiBaF3 is a suitable active media for imaging of slow neutrons

  10. Ionising radiation from uranium mining in Australia - some legal issues

    International Nuclear Information System (INIS)

    Despite the industrial dangers associated with the extraction and milling of uranium ore, it was not until 1978 that legislation brought into force a Code of Practice in Australia which required surveillance and monitoring of radiation levels in the mine site and mill and which set limits on the exposure of individual workers. The paper briefly describes the dangers confronting uranium mine and mill workers; it then summarises the 1980 Code of Practice on the Mining and Milling of Radioactive Ores and explains the legal status of that Code. Criminal sanctions attaching to the Code may not readily be enforceable in practice. After alluding to the types of injuries which may flow from exposure to ionising radiation, the paper seeks to demonstrate that breaches of the Code of Practice will not necessarily result in civil liability, on the part of a mine operator, to pay common law damages to workers injured by exposure to ionising radiation. This is largely because the injured worker must prove that a particular injury is causally connected with exposure to a particular agent in a particular place, on the balance of probabilities, and it is doubtful whether a particular radiogenic injury can be traced to a particular cause. Thus, in practice, workers exposed to ionising radiation may not be able to avail themselves of common law remedies. Their rights under workers compensation legislation may be exclusive, in the circumstances. The paper concludes with suggestions for reform

  11. Synthesis and evaluation of new protecting agents against ionizing radiations; Synthese et evaluation de nouveaux agents de protection contre les rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Nadal, B.

    2009-10-15

    This thesis is devoted to the synthesis of new pulvinic acid derivatives and the evaluation of their antioxidant and radioprotective properties. This study has been conducted with the aim to develop new protecting agents against ionizing radiations. A new access to pulvinic acid derivatives was developed starting from L-dimethyl tartrate. It is based on a Dieckmann cyclization a dehydration and a Suzuki-Miyaura coupling. It allows a short effective preparation of various pulvinic acid derivatives: tetronic acid derivatives, mono-substituted pulvinic acid derivatives and methyl pulvinates. A modified method has been used to prepare pulvinones. This strategy gave access in four steps to the desired pulvinones. The rapidity of this method is provided by a tandem process, carried out in the final step, involving a Dieckmann cyclization and a {beta}-elimination. A synthesis of 3-aryltetramic acids has also been developed in order to prepare nitrogen derivatives of pulvinic acid. The antioxidant activity of the prepared compounds was then evaluated using various tests: DPPH, ABTS, protection of thymidine and DNA study of lipid peroxidation. These evaluations allowed to define interesting structure-activity relationships of pulvinic derivatives. They have shown that several derivatives have very good antioxidant activities. Finally, radioprotective tests on TK6 cells and mice have have been performed on selected compounds. (author)

  12. Thyroid cancer following exposure to ionising radiation; Cancer de la thyroide apres exposition aux rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Schlumberger, M. [Institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Universite Paris Sud 11, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Chevillard, S.; Ory, K. [Commissariat a l' energie atomique et aux energies alternatives, route du Panorama, 92265 Fontenay-aux-Roses cedex (France); Dupuy, C. [Institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Universite Paris Sud 11, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); UMR 8200 CNRS, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Le Guen, B. [Division production nucleaire, direction production ingenierie, EDF, Tete-Pleyel, 1, place Pleyel, 93282 Saint-Denis cedex (France); De Vathaire, F. [Institut de cancerologie Gustave-Roussy, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); Universite Paris Sud 11, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France); equipe d' epidemiologie des radiations, centre d' etudes en sante des populations, UMR 1018 Inserm, 114, rue edouard-Vaillant, 94805 Villejuif cedex (France)

    2011-08-15

    Exposure to ionising radiations during childhood increases the risk of thyroid cancer. Similar risk factors have been found after external radiation exposure or internal contamination with radioactive iodine isotopes. In case of contamination with radio-iodines, administration of potassium iodide can prevent thyroid irradiation. (authors)

  13. Appraisal of alternative skin model for the study of epidermal restoration following exposure to various environmental stress agents: ionising radiation and UV B

    International Nuclear Information System (INIS)

    Human skin is a major target tissue for ionising radiation (IR) and UV B. We developed a skin explant model and used 2 types of keratinocytes to study survival and oxidative stress induced by these radiations. We examined oxidative damages by measuring R.O.S. produced and cellular anti-oxidant defenses induced. We observed into skin exposed to IR a modulation of genes expression implied in the control of oxidative stress, confirmed by the decrease of catalase, glutathione peroxidase and superoxide dismutase enzymatic activities. The imbalance observed between anti- and pro-apoptotic genes expression shows that keratinocytes apoptosis may be partly dependent on radio-induced R.O.S. production. We showed the difference of radiosensitivity between N.H.E.K. and Ha Ca.T., which may be linked to their differential oxidative responses. In addition, during re-epithelialising, we demonstrated that activated N.H.E.K. after IR express keratin 6, release pro-inflammatory cytokines and proliferate, without modification of their differentiation. Treatment of N.H.E.K. with geranyl geranylacetone (G.G.A.) has a beneficial effect on their radio-induced activation by increasing IL-1 release, their migration in scrapped area and their survival. G.G.A. has an anti apoptotic ability (induction of Hsp70- caspase-3 pathway) and migratory properties (P38/RhoA activation) on N.H.E.K., but after IR, only caspase-3 pathway is induced. This work thus contributes to the understanding of cutaneous damages after IR and G.G.A. mechanism of action which accelerates re-epithelialising. (author)

  14. QUANTIFICATIONS OF THE DETRIMENTAL HEALTHEFFECTS OF IONISING RADIATION

    OpenAIRE

    Walsh, Linda

    2013-01-01

    This thesis, presented to The University of Manchester in 2012 by Dr. Linda Walsh, is in fulfilment of the requirements for the degree of Doctor of Science (DSc) and is entitled “Quantifications of the detrimental health effects of ionising radiation.” A body of work and ensuing publications covering 2000–2012 are presented, predominantly concerning studies of various cohorts of people exposed to ionising radiation. The major areas cover epidemiological and statistical studies on the Life spa...

  15. Immunosuppression by non-ionising and ionising radiation - are there similarities?

    International Nuclear Information System (INIS)

    Solar UV radiation, the ubiqitous environmental non-ionising radiation, initiates its immunomodulating effects almost entirely in the skin. In direct contrast, ionising radiation penetrates much more efficiently, and has a multitude of internal targets throughout the body. As a consequence, the mechanisms underlying UV-induced immunosuppression have been more readily characterised, whereas surprisingly little is known about immunosuppression resulting from ionising radiation. Photoimmunological studies in mice during the past 20-30 years have established the action spectrum for UV-induced immunosuppression, implicating the UVB waveband, 290-320 nm. Controversy rages over the immunosuppressive potential of the UVA waveband, 320-400 nm, but we demonstrate that environmentally relevant doses of UVA not only are immunologically innocuous, but provide protection against UVB-immunosuppression. Increasingly larger UVA exposures increasingly immunosuppress mice. The UVA immunoprotective effect is strongly dependent on the induction of a cutaneous redox-regulated enzyme, haem oxygenase (heat shock protein 32) that is known to protect cells from oxidative stress, and it is consistent that a number of exogenous antioxidants (vitamin E, vitamin C, green tea polyphenols, isoflavones) can protect effectively from photoimmuno-suppression. Thus the UV-immunosuppressed state is promoted by oxidative damage and depletion of endogenous antioxidant molecules. It is also associated with cutaneous cytokine derangements, such that Th-2 cytokines (IL-4, IL-10) are increased at the expense of Th-1 cytokines (IFN-gamma, IL-12), and with histamine and inflammatory prostaglandin activity. In contrast, immunoprotective UVA irradiation protects the cutaneous cytokine array, inhibits IL-10 upregulation and increases IFN-gamma and IL-12 expression. On the other hand, while ionising radiation is known to cause immunosuppression, large doses target the bone marrow and haemopoiesis lethally and

  16. The case against protecting the environment from ionising radiation

    International Nuclear Information System (INIS)

    The objective of this paper is to present the (rarely heard) argument in favour of retention of the present system of radiation protection of the environment. There has been a recent trend in the radioecological and radiation protection community towards greater regulation of the effects of ionising radiations on biota. In particular, the often quoted International Commission on Radiation Protection (ICRP) hypothesis that: If humans are protected from the effects of ionising radiation, then flora and fauna are also adequately protected has been criticised as being too anthropocentric and not adequate for protection of the environment. In this paper I will challenge this view, arguing firstly that this statement is almost always quoted out of its proper context, and secondly that the ICRP hypothesis does adequately protect the environment from the effects of ionising radiations. In view of the relatively insignificant effect of regulated releases of ionising radiation on the environment, the economic cost of further regulation will not result in a significant environmental benefit. Whilst empirical research to test the ICRP hypothesis should continue, until there is clear evidence against it, this simple and cost-effective approach should be retained. This would benefit the environment by directing scarce resources to more urgent environmental problems. (author)

  17. Dosimetry of ionising radiation in modern radiation oncology.

    Science.gov (United States)

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B

    2016-07-21

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these. PMID:27351409

  18. Dosimetry of ionising radiation in modern radiation oncology

    Science.gov (United States)

    Kron, Tomas; Lehmann, Joerg; Greer, Peter B.

    2016-07-01

    Dosimetry of ionising radiation is a well-established and mature branch of physical sciences with many applications in medicine and biology. In particular radiotherapy relies on dosimetry for optimisation of cancer treatment and avoidance of severe toxicity for patients. Several novel developments in radiotherapy have introduced new challenges for dosimetry with small and dynamically changing radiation fields being central to many of these applications such as stereotactic ablative body radiotherapy and intensity modulated radiation therapy. There is also an increasing awareness of low doses given to structures not in the target region and the associated risk of secondary cancer induction. Here accurate dosimetry is important not only for treatment optimisation but also for the generation of data that can inform radiation protection approaches in the future. The article introduces some of the challenges and highlights the interdependence of dosimetric calculations and measurements. Dosimetric concepts are explored in the context of six application fields: reference dosimetry, small fields, low dose out of field, in vivo dosimetry, brachytherapy and auditing of radiotherapy practice. Recent developments of dosimeters that can be used for these purposes are discussed using spatial resolution and number of dimensions for measurement as sorting criteria. While dosimetry is ever evolving to address the needs of advancing applications of radiation in medicine two fundamental issues remain: the accuracy of the measurement from a scientific perspective and the importance to link the measurement to a clinically relevant question. This review aims to provide an update on both of these.

  19. Ionising radiation safety training in the Australian Defence Organisation (ADO)

    International Nuclear Information System (INIS)

    Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation. However, most are designated as radiation protection officers as a secondary duty. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A Training Course, responding to these requirements, has been developed to emphasize, basic radiation theory and protection, operation of radiation monitors available in the ADO, an understanding of the Ionising Radiation Safety Manual, day-to-day radiation safety in units and establishments, and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved successful, both for the students and the ADO generally. To seek national accreditation of the course through the Australian National Training Authority, as a first step, competency standards have been proposed. (authors)

  20. IEC standards for individual monitoring of ionising radiation

    International Nuclear Information System (INIS)

    This paper presents IEC/SC 45B 'Radiation protection instrumentation' and its standards for individual monitoring of ionising radiation: IEC 61526 Ed. 3 for active personal dosemeters and IEC 62387-1 for passive integrating dosimetry systems. The transposition of these standards as CENELEC (European) standards is also discussed together with the collaboration between IEC/SC 45B and ISO/TC 85/SC 2. (authors)

  1. Medical use of ionising radiation - challenges for the third millennium

    International Nuclear Information System (INIS)

    From the very beginning after its discovery ionising radiation has been in beneficial use for health care. But even the drawbacks showed up very early: only a few months after Roentgens discovery reports were published on patients who got severe skin damage after fluoroscopy with x-rays. This finding of the adverse effects was soon turned into something positive: ionising radiation could be used for treatment of cancer. In 1928 radiologists took the initiative to the foundation of what later became the International Commission on Radiological Protection, ICRP. Medical use of ionising radiation is giving by far the largest contribution to the radiation burden of the global population from artificial sources, on average 0,3 mSv per year and inhabitant, excluding doses from radiation treatment. In the Nordic countries this dose is approximately 0,7 mSv. This isn't a problem by itself. The total benefit is exceeding the total radiation risk with large margins. But the margins could even be larger. Methods for examinations and treatments have often a potential for improvements, meaning that the medical effect can be obtained with a lower dose to the patient. In certain circumstances the examination does not contribute to the further treatment of the patient or to her/his well-being and is then regarded as not justified. The huge challenge we are facing depends among other things on the extreme fast technical development which enables exposures of a magnitude that we haven't seen before and applications we only could dream about. There is a risk that the motto 'do what is possible to do' is followed instead of 'do what the individual patient needs'. This presentation addresses the possibilities, but also the dangers that medical use of ionising radiation in medical care is facing in the new millennium, or at least in its first years. (orig.)

  2. Complex systems of biological interest stability under ionising radiations

    International Nuclear Information System (INIS)

    This PhD work presents the study of stability of molecular systems of biological interest in the gas phase after interaction with ionising radiations. The use of ionising radiation can probe the physical chemistry of complex systems at the molecular scale and thus consider their intrinsic properties. Beyond the fundamental aspect, this work is part of the overall understanding of radiation effects on living organisms and in particular the use of ionizing radiation in radiotherapy. Specifically, this study focused on the use of low-energy multiply charged ions (tens of keV) provided by the GANIL (Caen), which includes most of the experiments presented. In addition, experiments using VUV photons were also conducted at synchrotron ELETTRA (Trieste, Italy). The bio-molecular systems studied are amino acids and nucleic acid constituents. Using an experimental crossed beams device allows interaction between biomolecules and ionising radiation leads mainly to the ionization and fragmentation of the system. The study of its relaxation dynamics is by time-of-flight mass spectrometry coupled to a coincidences measurements method. It is shown that an approach combining experiment and theory allows a detailed study of the fragmentation dynamics of complex systems. The results indicate that fragmentation is generally governed by the Coulomb repulsion but the intramolecular rearrangements involve specific relaxation mechanisms. (author)

  3. Use of ionising radiation for food processing applications

    International Nuclear Information System (INIS)

    Food irradiation is a recently developed technique used to sterilize and preserve food. Food products are exposed to ionising radiations such as X-rays, gamma rays or high energy electrons which destroy food borne pathogens and parasites and inhibit sprouting. Shelf life of food is extended. The following aspects of radiation processing of food are discussed in the monograph: radiation sources, choice of dose for specific results, safety and nutritional quality of radiation processed food, international status of acceptance of food irradiation, and cost. (M.G.B.). 6 tabs

  4. Protection aspects in ionising radiation applications

    International Nuclear Information System (INIS)

    Availability of (i) locally made and good quality equipment which satisfy stringent radiation protection standards, (2) tailor-made programmes for training of physicists, physicians, engineers, technologists and researchers in radiation safety and the resultant production of adequate number of well trained personnel (who as users are also made to be involved in decision making on radiation protection programmes and policies), (3) codes, guides, manuals and brochures on radiation safety in different disciplines, and (4) legal and administrative backing for the radiation protection efforts at the governmental level for optimal regulation - not over regulate or over police - should be considered as the real positive points of radiation protection infrastructure in the country. 11 tabs

  5. Ionising radiation safety training in the Australian defence organisation (ADO)

    International Nuclear Information System (INIS)

    Full text: Training personnel in ionising radiation safety within the Australian Defence Organisation (ADO) requires addressing some unique features of an organisation employing both military and civilian personnel. Activities may include those of a civil nature (such as industrial and medical radiography), specific military requirements (for training and emergency response) and scientific research and development. Some personnel may be assigned to full-time duties associated with radiation, while others may be designated as radiation protection officers in remote units with few duties to perform in this role. A further complication is that most military personnel are subjected to postings at regular intervals. The ADO's Directorate of Defence Occupational Health and Safety has established an Ionising Radiation Safety Subcommittee to monitor not only the adequacy of the internal Ionising Radiation Safety Manual but also the training requirements. A training course, responding to these requirements, has been developed to emphasise: basic radiation theory and protection; operation of radiation monitors available in the ADO; an understanding of the Safety Manual; day-to-day radiation safety in units and establishments; and appropriate responses to radiation accidents and emergencies. In addition, students are briefed on a limited number of peripheral topics and participate in some site visits. Currently, two Courses are held annually, each with about twenty students. Most of the material is presented by ADO personnel with external contractor support. The three Courses held to date have proved sufficiently successful, both for the students and the ADO generally, to seek national accreditation through the Australian National Training Authority and, as a first step, competency standards have been identified

  6. Cytogenetic effects of low ionising radiation doses and biological dosimetry

    OpenAIRE

    Gricienė, Birutė

    2010-01-01

    The intensive use of ionising radiation (IR) sources and development of IR technology is related to increased exposure and adverse health risk to workers and public. The unstable chromosome aberration analysis in the group of nuclear energy workers (N=84) has shown that doses below annual dose limit (50 mSv) can induce chromosome aberrations in human peripheral blood lymphocytes. Significantly higher frequencies of the total chromosome aberrations were determened in the study group when compa...

  7. Non-targeted effects of ionising radiation

    International Nuclear Information System (INIS)

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

  8. CVD diamond detectors of ionising radiation

    International Nuclear Information System (INIS)

    Diamond is a resilient material with excellent physical properties for radiation experiments. As such it is an interesting material for fabrication of high performance solid-state particle detectors operating at room temperature. Its high radiation hardness makes it an ideal material in high radiation environment. High breakdown voltage allows application of high electric field and so speeds up the charge collection. Diamond manufacturing technology (CVD) allows low cost diamond production in large sheets and with higher purity than nature diamonds. There have been already produced CVD diamond detectors with coaxial geometry, planar, micro-strip and pixel detectors. Also at Slovak University of Technology have been already produced first CVD diamond layers. (authors)

  9. Control of ionising radiation - a UK viewpoint

    International Nuclear Information System (INIS)

    The primary aim of radiological protection is to provide an appropriate standard of protection for mankind, both as individuals and collectively, without unduly limiting the beneficial practices giving rise to radiation exposure. Guidance on the fundamental principles for radiation protection is provided on a global scale by the International Commission on Radiological Protection (ICRP). Member states of the European Union, such as the UK, are bound by the Euratom Treaty that requires the Commission of the European Communities (CEC) to develop uniform standards for radiological protection. These standards are based on recommendations from ICRP and are laid down in Euratom Directives relating to the safety of workers and the public, and of patients undergoing medical exposures. Member states are required to introduce national legislation to comply with Directives. In addition to ICRP and CEC, other international bodies are involved in developing practical standards and guidelines for radiological protection. For example, the International Atomic Energy Agency (IAEA) provides guidelines relating to the transport of radioactive material, and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) provides information on the biological effects of radiation. In the UK, the National Radiological Protection Board (NRPB) was established in 1970 as a statutory advisory body. It has no regulatory functions. NRPB advises Government on the acceptability and applicability of international recommendations. Principles are then applied in the UK by Acts of Parliament and subsidiary instruments such as regulations, licences, authorizations and approvals. Various government departments are involved in policing the control of radiation according to their particular role, for example the Department of the Environment in relation to pollution, and the Department of Employment for the health and safety of workers. (author)

  10. Population exposure to ionising radiation in India

    International Nuclear Information System (INIS)

    Estimates of exposure from various radiation sources to Indian population are given. The per caput dose from all the identifiable sources, both natural and man-made is estimated to be 2490 μSv per year to the present population of India. 97.9% of this dose is contributed by natural sources which include cosmic and terrestrial radiations, 1.93% by medical sources used for diagnostic and treatment purpose, 0.3% by exposures due to activities related nuclear fuel cycle, nuclear tests and nuclear accidents, and 0.07% by miscellaneous sources such as industrial applications, consumer products, research activities, air travel etc. The monograph is written for the use of the common man. (M.G.B.). 25 refs., 7 tabs., 7 figs

  11. Recent trends in utilising ionising radiations for nondestructive evaluation of materials (Preprint No. SP-3)

    International Nuclear Information System (INIS)

    The various NDT techniques based on the use of ionising radiations can be broadly classified into radiography, radiation gaging techniques and analytical techniques. This paper highlights the state of art of these techniques along with their applications. While an effort has been made to cover the major techniques based on ionising radiations, many techniques utilising ionising radiations as xeroradiography, laminography, ionography etc, have not been dealt with due to their restricted applications. (author). 23 refs., 4 figs

  12. On ionising radiation and breast cancer risk

    International Nuclear Information System (INIS)

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

  13. On ionising radiation and breast cancer risk

    Energy Technology Data Exchange (ETDEWEB)

    Mattson, Anders

    1999-05-01

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

  14. Fitness of equipment used for medical exposures to ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-07-01

    The advice in this guidance note is aimed at employers in control of equipment used for medical exposures to ionising radiation and ancillary equipment. This includes NHS trusts, health authorities or boards, private hospitals, clinics, surgeries, medical X-ray facilities in industry, dentists and chiropractors. The guidance should also be useful to radiation protection advisers appointed by such employers. The guidance provides advice on the requirements of regulation 33 of the Ionising Radiations Regulations 1985 (IRR85). In particular, it covers: (a) the selection, installation, maintenance, calibration and replacement of equipment to ensure that it is capable of restricting, so far as reasonably practicable, the medical exposure of any person to the extent that this is compatible with the intended diagnostic or therapeutic purpose; (b) recommended procedures for the definitive calibration of radiotherapy treatment; and (c) the need to investigate incidents involving a malfunction or defect in any 'radiation equipment' which result in medical exposures much greater than intended and to notify the Health and Safety Executive (HSE). 'Medical exposure' is defined in IRR85 as exposure of a person to ionising radiation for the purpose of his or her medical or dental examination or treatment which is conducted under the direction of a suitably qualified person and includes any such examination or treatment conducted for the purposes of research. For convenience, people undergoing medical exposure will be referred to as 'patients' in this guidance. Nothing in this publication is intended to indicate whether or not patients should be informed of any incident resulting from malfunction or defect in equipment used for medical exposure and the possible consequences of that exposure. As stated above, this guidance concerns medical exposures much greater than intended and although exposures much lower than intended can also have serious

  15. Fitness of equipment used for medical exposures to ionising radiation

    International Nuclear Information System (INIS)

    The advice in this guidance note is aimed at employers in control of equipment used for medical exposures to ionising radiation and ancillary equipment. This includes NHS trusts, health authorities or boards, private hospitals, clinics, surgeries, medical X-ray facilities in industry, dentists and chiropractors. The guidance should also be useful to radiation protection advisers appointed by such employers. The guidance provides advice on the requirements of regulation 33 of the Ionising Radiations Regulations 1985 (IRR85). In particular, it covers: (a) the selection, installation, maintenance, calibration and replacement of equipment to ensure that it is capable of restricting, so far as reasonably practicable, the medical exposure of any person to the extent that this is compatible with the intended diagnostic or therapeutic purpose; (b) recommended procedures for the definitive calibration of radiotherapy treatment; and (c) the need to investigate incidents involving a malfunction or defect in any 'radiation equipment' which result in medical exposures much greater than intended and to notify the Health and Safety Executive (HSE). 'Medical exposure' is defined in IRR85 as exposure of a person to ionising radiation for the purpose of his or her medical or dental examination or treatment which is conducted under the direction of a suitably qualified person and includes any such examination or treatment conducted for the purposes of research. For convenience, people undergoing medical exposure will be referred to as 'patients' in this guidance. Nothing in this publication is intended to indicate whether or not patients should be informed of any incident resulting from malfunction or defect in equipment used for medical exposure and the possible consequences of that exposure. As stated above, this guidance concerns medical exposures much greater than intended and although exposures much lower than intended can also have serious consequences, the incident would not

  16. Appraisal of alternative skin model for the study of epidermal restoration following exposure to various environmental stress agents: ionising radiation and UV B; Evaluation d'un modele alternatif de peau dans l'etude de l'atteinte epidermique apres exposition a differents agents de stress environnementaux: rayonnements ionisants (RI) et ultra-violets B (UVB)

    Energy Technology Data Exchange (ETDEWEB)

    Isoir, M

    2006-06-15

    Human skin is a major target tissue for ionising radiation (IR) and UV B. We developed a skin explant model and used 2 types of keratinocytes to study survival and oxidative stress induced by these radiations. We examined oxidative damages by measuring R.O.S. produced and cellular anti-oxidant defenses induced. We observed into skin exposed to IR a modulation of genes expression implied in the control of oxidative stress, confirmed by the decrease of catalase, glutathione peroxidase and superoxide dismutase enzymatic activities. The imbalance observed between anti- and pro-apoptotic genes expression shows that keratinocytes apoptosis may be partly dependent on radio-induced R.O.S. production. We showed the difference of radiosensitivity between N.H.E.K. and Ha Ca.T., which may be linked to their differential oxidative responses. In addition, during re-epithelialising, we demonstrated that activated N.H.E.K. after IR express keratin 6, release pro-inflammatory cytokines and proliferate, without modification of their differentiation. Treatment of N.H.E.K. with geranyl geranylacetone (G.G.A.) has a beneficial effect on their radio-induced activation by increasing IL-1 release, their migration in scrapped area and their survival. G.G.A. has an anti apoptotic ability (induction of Hsp70- caspase-3 pathway) and migratory properties (P38/RhoA activation) on N.H.E.K., but after IR, only caspase-3 pathway is induced. This work thus contributes to the understanding of cutaneous damages after IR and G.G.A. mechanism of action which accelerates re-epithelialising. (author)

  17. Biological monitors for low levels of ionising radiation

    International Nuclear Information System (INIS)

    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)

  18. Investigation of damage mechanism by ionising radiation on biomolecules

    International Nuclear Information System (INIS)

    Occupational radiation hazard is a very controversial subject. Effects from high radiation doses are well known from past experiences. However, hazard from low doses is still a subject that is hotly debated upon until now. The occupational dosimetry used now is based on a macroscopic scale. Lately, microdosimetry is fast gaining recognition as a more superior way of measuring hazard. More importantly, scientists are researching the basic damage mechanism that leads to biological effects by ionising radiation. In this report, a simulation study of the basic damage mechanism is discussed . This simulation is based upon Monte Carlo calculations and using polyuridylic acid (Poly-U) as the DNA model This simulation tries to relate the physics and chemistry of interactions of ionising radiation with biomolecules. The computer codes used in this simulation, OREC and RADLYS were created by Hamm et al. (1983) in Oak Ridge National Laboratory. The biological endpoints in this simulation are the strand break and base release of the DNA, which is the precursor of all biological effects. These results are compared with model studies that had been done experimentally to check the validity of this simulation. The G-values of strand break and base release from this simulation were -2.35 and 2.75 and compared well with results from irradiation experiments by von Sonntag (I 98 7) from Max Plank's Institute, Germany

  19. Studies of Non-Targeted Effects of Ionising Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Oleg V Belyakov; Heli Mononen; Marjo Peraelae [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2006-07-01

    The discovery of ionising radiation induced non-targeted effects is important for understanding the dose-response mechanisms relevant to low dose irradiation in vivo. One important question is whether the non-targeted effects relates to a protective mechanism or whether, conversely, it amplifies the number of cells damaged by the isolated radiation tracks of low dose exposures leading to an increased risk of carcinogenesis. One theory supported by the experimental data obtained during this project is that the main functions of the non-targeted effects are to decrease the risk of transformation in a multicellular organism exposed to radiation. Differences in the gene expression profiles, temporal and spatial patterns of key proteins expressed in directly irradiated and bystander cells may determine how the cells ultimately respond to low doses of radiation. Such a mechanism of co-operative response would make the tissue system much more robust. (N.C.)

  20. Studies of Non-Targeted Effects of Ionising Radiation

    International Nuclear Information System (INIS)

    The discovery of ionising radiation induced non-targeted effects is important for understanding the dose-response mechanisms relevant to low dose irradiation in vivo. One important question is whether the non-targeted effects relates to a protective mechanism or whether, conversely, it amplifies the number of cells damaged by the isolated radiation tracks of low dose exposures leading to an increased risk of carcinogenesis. One theory supported by the experimental data obtained during this project is that the main functions of the non-targeted effects are to decrease the risk of transformation in a multicellular organism exposed to radiation. Differences in the gene expression profiles, temporal and spatial patterns of key proteins expressed in directly irradiated and bystander cells may determine how the cells ultimately respond to low doses of radiation. Such a mechanism of co-operative response would make the tissue system much more robust. (N.C.)

  1. Review of retrospective dosimetry techniques for external ionising radiation exposures

    International Nuclear Information System (INIS)

    The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements. (authors)

  2. Romanian medical exposure to ionising radiation in 2012

    International Nuclear Information System (INIS)

    Medical exposure, the main source of artificial exposure, shows an increasing trend in the last years, manifested both by increasing the number of examinations with ionising radiation and by increasing the patient dose level. Annual results obtained for medical exposure to ionising radiation based on the data collected from Romanian hospitals are useful for the update of the national database and optimisation of diagnostic procedures in radiology and nuclear medicine. Medical exposure level is expressed in terms of annual collective dose and is evaluated from annual frequencies and the average effective dose per procedure for different types of radiological and nuclear medicine procedures. The Romanian hospitals reported during 2012 a number of 5 505 792 radiological examinations and 17 088 diagnostic procedures of nuclear medicine. Based on the data reported, the average effective doses and their contributions to the collective dose were evaluated. The main contributions to the collective dose of the radiological procedures are registered for CT abdomen and pelvis region, followed by thorax CT and head CT examinations. The next positions are fluoroscopic examination of the thorax and gastrointestinal disease and radiographic examination of the lumbar spine and thorax, which in spite of their low effective dose have an important contribution to the collective dose due to the large number of examinations. For nuclear medicine procedures, major contributions to collective dose are given by bone scintigraphy, followed by PET-CT and thyroid scintigraphy. (authors)

  3. Issues related to radiation protection in the medical application of ionising radiation

    International Nuclear Information System (INIS)

    The medical application of ionising radiation is by far the largest contributor (about 95%) to human exposures from manmade sources of radiation. Diagnostic radiology, radiotherapy, nuclear medicine and interventional radiology procedures are common sources of the medical exposures. In addition to medical exposures, exposures also result from other radiation related occupational activities. This paper endeavours to summarise the relevant findings, conclusions and recommendations of UNSCEAR Report 2000 and the two recent IAEA international conferences, namely, (1) International Conference on the Radiological Protection of Patients in Diagnostic and Interventional Radiology, Nuclear Medicine and Radiotherapy, Malaga, Spain, 2001, and (2) International Conference on Occupational Radiological Protection: Protecting Workers against exposure to ionising radiation, Geneva, Switzerland, 2002, with reference to medical applications of ionising radiation

  4. Protection of the environment from ionising radiation: ethical issues

    International Nuclear Information System (INIS)

    The paper identifies some of the main ethical issues concerning the protection of the environment from radiation and suggests ways in which ethics can aid in developing a system of protection. After a presentation of background on ethical theory and environmental ethics, three main issues related to environmental protection are discussed: First, the question of valuing the environment and implications for the definition of harm and monetary valuation of environmental goods; second, difficulties with scientific uncertainty and applications of the precautionary principle; and third, issues concerned with the distribution of risk and its relevance fo participation in decision-making. In summary, the paper argues that there are strong ethical grounds to provide for the protection of the environment and that, all other things being equal, there is no reason to treat ionising radiation differently to other environmental stressors

  5. Protection of the environment from ionising radiation: ethical issues

    International Nuclear Information System (INIS)

    The paper identifies some of the main ethical issues concerning the protection of the environment from radiation and suggests ways in which ethics can aid in developing a system of protection. After a presentation of background on ethical theory and environmental ethics, three main issues related to practical environmental protection are discussed: First, the question of who or what has moral standing; second the appropriate level of protection; and third compatibility with other environmental stressors. In summary, the paper argues that there are strong ethical grounds for efforts to provide for the protection of the environment and that, all other things being equal, there is no reason to treat ionising radiation differently to other environmental stressors. (author)

  6. International Conference on Low Doses of Ionising Radiation

    International Nuclear Information System (INIS)

    Is there a threshold? and is a little radiation good for you? were two questions raised at the International Conference on Low Doses of Ionising Radiation : Biological Effects and Regulatory Control, jointly organised by the IAEA and WHO, and convened in Seville, Spain, over 17-21 November 1997. The answer to both these questions appears to be 'Maybe', but the answer has no present implications for radiation protection practice and regulation. The conference which had over 500 participants from 65 countries, was organised around ten fora which explored basic molecular mechanisms of radiation effects, through to radiation protection principles and implementation in practices and interventions. Each forum was introduced by an overview presentation by an invited keynote speaker. Brief presentations of a few of the proffered papers followed, and then open discussion. There was opportunity for all proffered papers to be presented as posters. The fora, which occupied 3 full days, were preceded by reports on biological effects of radiation from international orgnaisations, and on related international conferences held in the recent past. The fora were followed by round table presentations of regulatory control and scientiFic research, and a summary session drawing together conclusions on the topic areas of the conference. (author)

  7. The use of detectors based on ionisation recombination in radiation protection

    International Nuclear Information System (INIS)

    Intitial recombination of ionisation in a gas depends on the ionisation density and hence on the linear energy transfer along the tracks of charged particles. This effect can be used as a basis for instruments that respond to different types of ionising radiation approximately in the way required by the quality factor-linear energy transfer relation recommended by the ICRP for use in radiation protection. Empirical instruments based on ionisation recombination that have been used for radiation protection measurements are reviewed, and relations are derived from recombination theory that show that the response of such detectors can be readily predicted. The usefulness of recombination instruments in radiation protection is discussed and their advantages and limitations assessed. It is shown that their main application will be as reference instruments against which other detectors can be calibrated. As an extension to using recombination detectors as reference instruments, the feasibility of specifying radiation quality in terms of ionisation recombination is investigated. (author)

  8. Radicals of DNA and DNA nucleotides generated by ionising radiation

    International Nuclear Information System (INIS)

    A first stage of cell processes leading to DNA damage of initiated by radical reactions. In a model system such transformations were generated by ionising radiation which involves production of electron loss and electron gain centers of the substrate and radical formation. Using cryogenic ESR spectroscopy it was found that the DNA nucleotides, which convert to radical anions upon electron capture undergo the separation of unpaired spin and charge due to protonation. Circular and linear dichroism studies enabled to conclude that iron ions(III) induce strong changes in the DNA helical structure indicating their coordination with nitrogen bases. The repair of DNA radicals produced via radiolytic oxidation, i.e. the guanine radical cation and the allyl type radical of thymine, is possible at elevated temperatures due to the involvement of sulphydryl groups. The influence of the thiol charge is then limited

  9. Martian sub-surface ionising radiation: biosignatures and geology

    Directory of Open Access Journals (Sweden)

    J. M. Ward

    2007-07-01

    Full Text Available The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionising radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Here, we present modelling results of the absorbed radiation dose as a function of depth through the Martian subsurface, suitable for calculation of biomarker persistence. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments.

    We present calculations of the dose-depth profile in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost, solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude, and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and discuss particle deflection by the crustal magnetic fields.

  10. Education and training issues in individual monitoring of ionising radiation

    International Nuclear Information System (INIS)

    The present article deals with the education and training (E and T) issues of individual monitoring (IM) of ionising radiation, based on the requirements provided by the Basic Safety Standards EURATOM Directive and the European Commission Technical Recommendations for IM of external radiation. The structure and the objectives of E and T programmes addressed to the staff of dosimetry services, in order to allow the recognition and ensure the continuity of expertise are discussed. The necessity for the establishment of a national strategy for building competence in IM through information, education, training and retraining programmes, addressed to the individually monitored personnel is underlined. The train the trainers' concept is recognised as being an important tool for optimising resources and transferring the skills necessary for building competence. The conditions under which an efficient train the trainers' approach can be established are discussed. Examples of curricula concerning the key persons involved in the provision of E and T in occupational radiation protection are also given. (authors)

  11. Making ionising radiation a real experience for high school science students

    International Nuclear Information System (INIS)

    The Canadian public has little understanding of ionising radiation due in part to its treatment in popular media. In principle, students learn about ionising radiation in their school science classes. Developments in science curricula are providing more education opportunities for this subject. The Canadian Nuclear Society's program for introducing real, personal experience with ionising radiation in the classroom is starting to make a difference. The demand is expected to exceed the resources of the CNS and the program is being developed to facilitate external support. This paper summarizes the need, the history of this program development, and the path forward. (author)

  12. Proceedings. Protection of the natural environment. International symposium on ionising radiation

    International Nuclear Information System (INIS)

    The symposium was organised jointly by the Swedish Radiation Protection Institute and the Atomic Energy Control Board of Canada. The programme was organised around six major topics: Biological effects of ionising radiation; Ecological effects of ionising radiation; Behaviour and transport of radionuclides in the natural environment; Criteria for environmental protection; Assessment methodology; and Social and economic aspects. All 86 contributions (excluding the opening addresses) have been separately indexed

  13. Using ionising radiation against terrorism and contrabandism - dosimetric problems

    International Nuclear Information System (INIS)

    As will be explained in more detail in a talk at this conference, the personnel X-ray scanners can be divided into two groups, one using the transmitted X rays for image creation, the other one using the Compton back scatters X-rays. In the case of a backscatter scanner, a narrow, pencil -like X-ray beam is produced by a rotating chopper-wheel. The person/object is scanned in a raster scan pattern. The backscattered X-rays of all points are measured and recorded. The transmission X-ray scanner can use both fan-like and pencil like X-ray beams. The transmission detectors are installed behind the object and detect the absorption of the scanned person. Due to the very low dose values of the X-ray scanner systems in combination with a high dose rate in the direct beam for a short irradiation time, special dosemeters have to be used. In the literature and in manufacturers' specifications, the dose values given for some systems are in the range from 0.05 μSv to 5 μSv per scan with a typical irradiation time of a few milliseconds. Due to this pulse-like character of the radiation fields, the dose rate is several sieverts per hour. For the measurements of the investigated scanner, dosemeters were therefore needed having the capability to measure low doses at high dose rates and to measure in pulsed radiation fields. For the optimization of the measurements, the use of measuring devices with a direct indication is necessary. Ionisation chambers are the most suitable measuring instruments to fulfill these requirements. The difficulty for the measurements with an ionisation chamber is that the leakage charge integrated over time can reach values at the level of the expected radiation-produced charge. Additionally unpredictable variations of the leakage charge can be in the same order of magnitude as the expected signal. This challenge led to the development of a special electronics which allow the execution of time-resolved measurements. With this time resolution, it is

  14. Evaluation of background ionising radiation levels within Gwagwalada town, Abuja

    International Nuclear Information System (INIS)

    The background ionising radiation levels within Gwagwalada Town, Abuja has been carried out using Atomtex 1117M Radiation Monitor. Readings were taken in twelve different locations. Twenty different readings were taken at each location and the mean equivalent dose rate was used to calculate the annual equivalent dose rate. A total of 240 measurements were taken across the 12 locations in the study Area. It was observed that the average dose equivalent varied from 0.105±0.008 μSv/h to 0.114±0.015μSv/h with a mean of 0.109±0.013 μSv/h. The mean value from Ungwan Bassa shows the highest equivalent dose rate while the equivalent dose rate from Phase 3 was the lowest. Ungwan Dodo, Ungwan Gwari recorded the second and third highest in-situ gamma radiation of 0.113±0.013 μSv/h and 0.112±0.012 μSv/h respectively. The result shows that the entire equivalent dose rates of all the locations were below the value of the Standard Background Radiation of 0.133 μSv/h. The study also revealed that the average annual equivalent dose rate is 0.192±0.005 mSv/y which is lower than the value of 1.0 mSv/yr averaged over five consecutive years according to the dose limit recommended by the International Commission on Radiological Protection (ICRP).

  15. Ionising radiations produced in the vicinity of a petawatt laser

    Energy Technology Data Exchange (ETDEWEB)

    Borne, F. [CEA Bruyeres le Chatel, Service de Protection contre les Rayonnements 91 (France); Marques, J.R. [Ecole Polytechnique, Lab. pour l' Utilisation des Lasers Intenses, 91 - Palaiseau (France)

    2006-07-01

    A previous experimental study dedicated to radiological characterization of an experimental chamber and surrounding areas of an high intensity laser facility (100-Terawatt regime) revealed significant levels of X ray, gamma and neutrons radiations under particular experimental conditions which can significantly increase while upgrading of the intensity and regime of the laser. In order to improve the knowledge of radiations produced by the new generation of peta watt lasers ( {approx_equal}1021 W/cm{sup 2}) and the associated radiation protection safety devices and shielding in these facilities, a numerical study has been performed using the parameters of the future peta watt laser facility in the Laboratory for the Use of Intense Lasers at Ecole Polytechnique (L.U.L.I. - Palaiseau - France). Based on simulations with the Monte Carlo code M.C.N.P.X., an analysis of doses induced by ionising radiations produced by Bremsstrahlung reactions and secondary reactions, respectively in the laser interaction target and in the vacuum chamber, has been investigated on different positions of the facility, in order to define and size the appropriate materials for protection against external exposure in this new type of plant. These results are benchmarked with previous numerical and experimental results obtained with similar input parameters of the V.U.L.C.A.N. facility at the C.L.R.C. Rutherford Appleton Laboratory (R.A.L. - Oxon - England). This benchmark shows good agreement between these different results. The aim of the present publication is to present and discuss these numerical results. (authors)

  16. The Ionising Radiations Advisory Committee Open Meeting 10 October 2001

    International Nuclear Information System (INIS)

    Full text: The Ionising Radiations Advisory Committee (IRAC) held its first open meeting on 10 October 2001 in response to a request from the Health and Safety Commission (HSC) that all its advisory committees should follow the Commission's example and hold such meetings. Some of the other advisory committees have already held open meetings and others are planning to do so shortly. The aim of the meeting was to enable members of the public to meet IRAC members and to find out more about the Committee - how it worked and the type of issues it dealt with. The first two sessions were devoted to short presentations describing IRAC's work and influences, now and in the future, on radiation protection generally. The third session was a discussion forum. The agenda for the meeting and the presentations are posted on the web at: www.hse.gov.uk/foi/iracopen.htm. Each session of presentations was followed by questions of clarification and the third session of the meeting comprised an open forum. Many of the questions raised were not directly relevant to IRAC but, nevertheless, members provided brief responses and referred questions on to others as appropriate. One question had been notified in advance, asking whether members of IRAC agreed that it is now (regrettably) reasonably foreseeable that a loss of containment of radioactive material may occur at a nuclear facility as a result of impact by an aeroplane or by other hostile acts, and that this should be made clear in published guidance on REPPIR. This question was not within IRAC's remit. The Chairman of the Nuclear Safety Advisory Committee offered to take the question to the Committee's next meeting. Issues discussed included: Concerns that exposure to ionising radiation at low levels is more dangerous than is currently reflected in risk estimates. The European Parliament has adopted a resolution calling on the main international bodies, including the International Commission on Radiological Protection (ICRP), the

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Bernd

    2015-07-01

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

  19. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry

    International Nuclear Information System (INIS)

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  20. Application of ionising radiation to the pharmaceutical industry

    International Nuclear Information System (INIS)

    Pharmacons, commonly called 'Drugs', are subject to a many-sided procedure of development before they are released on the market and reach the patient. Again and again they are submitted to controls for safety reasons and at least seven (sometimes nine or ten) years pass before the active substance has made its way from chemistry through many trials with animals in experimental pathology and through the laboratories of the biochemistry department. Ionising radiation is used in each field of drug research as an additional method for obtaining information. In chemistry the structure of molecules can be detected by X-ray diffraction, and the active component elucidated. In the teratology section of experimental pathology the foetus just before delivery and newborn animals are X-rayed. This is in order to find out skeletal malformations that might have occurred during feeding of the substance in question during gestation. In biochemistry the pharmacon is labelled with a suitable radioactive isotope. Its way through the body can then be followed by measuring absorption rate, distribution, binding and elimination. It is also important to explore the influence of the drug on the organism and the reverse - how the pharmacon is influenced by the organism. This means examining the metabolites of the drug and the mechanism of action by means of serial auto-radiography and clearance or excretion studies. Gamma rays are employed for sterilisation of ointment tubes and vials just before filling. Sterilisation of the pharmacon is discussed. (author)

  1. Emissions and doses from sources of ionising radiation in the Netherlands: radiation policy monitoring

    International Nuclear Information System (INIS)

    In 1997 the Ministry of Housing, Spatial Planning and the Environment requested RIVM to develop an information system for policy monitoring. One of the motives was that the European Union requires that the competent authorities of each member state ensure that dose estimates due to practices involving exposure to ionising radiation are made as realistic as possible for the population as a whole and for reference groups in all places where such groups may occur. Emissions of radionuclides and radiation to the environment can be classified as follows: (1) emissions to the atmosphere, (2) emissions to the aquatic system and (3) emission of external radiation from radioactive materials and equipment that produces ionising radiation. Released radioactivity is dispersed via exposure pathways, such as the atmosphere, deposition on the ground and farmland products, drinking water, fish products, etc. This leads to radiation doses due to inhalation, ingestion and exposure to external radiation. To assess the possible radiation doses different kinds of models are applied, varying from simple multiplications with dispersion coefficients, transfer coefficients and dose conversion coefficients to complex dispersion models. In this paper an overview is given of the human-induced radiation doses in the Netherlands. Also, trends in and the effect of policy on the radiation dose of members of the public are investigated. This paper is based on an RIVM report published recently. A geographical distribution of radiation risks due to routine releases for a typical year in the Netherlands was published earlier

  2. What Influences Public Opinion About Risks of Ionising Radiation in Medicine

    International Nuclear Information System (INIS)

    Full text: Ionising radiation is used in many different ways and for different purposes in medicine. First of all, it is used both in diagnosing (radiology and in nuclear medicine) and therapy. When diagnosing diseases at an early stage, the amount of ionising radiation must be adequate to its specific purpose. In therapeutic medical exposures the usage of ionising radiation is acceptable for treating malignant diseases. Benign diseases (e.g. hyperthyreosis), on the other hand, do not always have to be treated with ionising radiation. Considering public perception of the risks of ionising radiation and their concern for the possible consequences, there are few aspects of how patients accept its use in diagnostic and therapeutic medical exposures. Some people are demanding such examinations and treatments even when there's the least significant symptom of disease. Others are very sceptic and refuse to risk their health (they are afraid of cancer) or to cause genetic effects. Our efforts are concentrated on creating realistic understanding of radiation risk among people. Only specialists in this field are competent and trusting persons who should introduce the patient with the gist of the problem. Their approach should be individual, since and above all, they should use understandable phrases. The intention of this paper is to discuss the main sources of influence on public perception of the (in)sufficiency of radiation protection in diagnosis and treating diseases in medicine. (author)

  3. The ionising radiation (medical exposure) regulations - IR (ME) R, Malta

    International Nuclear Information System (INIS)

    Full text: The regulations in Malta at present are in draft stage. These regulations partially implement European Council Directive 97/43/Euratom. This Directive lays down the basic measurements for the health and protection of individuals against dangers of ionising radiation in relation to medical exposure. The regulations impose duties on persons administering radiations, to protect people from unnecessary exposure whether as part of their own medical diagnosis, treatment or as part of occupational health worker for health screening, medico-legal procedures, voluntary participation in research etc. These regulations also apply to individuals who help other individuals undergoing medical exposure. Main provisions 1. Regulation 2 contains the definitions of 28 terms used in these regulations. 2. Regulation 3.1 and 3.2 sets out the medical exposures to which the regulations apply. 3. Regulation 4 requires approval of medical exposures due to medical research, from radiation protection board of Malta. 4. Regulation 5 prohibits new procedures involving medical exposure unless it has been justified in advance. 5. Regulation 6 provides conditions justifying medical exposures. It prohibits any medical exposure from being carried out which has not been justified and authorized and sets out matters to be taken into account for justification. 6. Regulation 7 requires that practitioner justifies the exposure, shall pay special attention towards (a) exposure from medical research procedures where there is no direct health benefit to the individual undergoing exposure, (b) exposures for medico-legal purposes; (c) exposures to pregnant or possible pregnant women and (d) exposures to breast-feeding women. 7. Regulation 8.1 to 8.3 prohibit any medical exposure from being carried out which has not been justified and sets out matters to be taken for justification 8. Regulation 8.4 prohibits an exposure if it cannot be justified. 9. Regulation 9 requires the employer to provide a

  4. A method of impact assessment for ionising radiation on wildlife

    International Nuclear Information System (INIS)

    A method for undertaking an impact assessment of ionising radiation on wildlife has been developed for the UK Environment Agency, who has a legal requirement to assess the impacts of consents and authorisations for discharges under the Habitats Regulations (1994). A simple approach has been adopted based on the latest thinking in the field, in which the calculation of doses to wildlife are determined by their size, internal incorporation of radionuclides and external exposure in the environment. The doses are calculated either by using literature derived values or empirical measurements of radionuclide concentrations at the site of interest. The data required to enable dose calculations are: - Concentrations of each radionuclide in the soil/sediment, water or air (from empirical or modelled approaches); - Concentration factors for each radionuclide in each organism to be assessed relative to soil, water or air (based on literature values or actual measurements at the site of interest); - Organism dimensions (as an ellipsoid); - The proportion of time the organism spends in different 'compartments' of the ecosystem. The impact assessment approach then focuses on three ecosystems representative of those considered potentially most at risk from the impact of authorised radioactive discharges, namely a coastal grassland (terrestrial ecosystem); estuarine and freshwater ecosystems. A range of target organisms have been chosen to be representative of species found in each ecosystem. Several radionuclides were initially selected for the impact assessment: - Estuarine and freshwater ecosystems: 3H, 14C, 99Tc, 90Sr, 137Cs, 239+240Pu, 238U, 129I, 210Po - Terrestrial ecosystem: 3H, 14C, 35S, 90Sr, 137Cs, 239+240Pu, 238U, 129I, 226Ra. Subsequently, the method has been extended to additional radionuclides, including all the major natural series radionuclides. Dose calculations have been programmed into user-friendly Excel spreadsheets using Visual Basic for Applications. The

  5. Fifty years of individual monitoring of ionising radiation in Switzerland: History, trends and perspectives

    International Nuclear Information System (INIS)

    In the last 50 y, individual monitoring of ionising radiation in Switzerland underwent substantial development, strongly influenced by type of applications of ionising radiation, monitoring technologies, knowledge of health risks, protection philosophies and regulatory frameworks. The role of individual monitoring in the system of radiation protection moved from a passive, a posteriori control of limits towards an important and more interactive tool for optimisation. Dose trends for occupational exposures document these developments. In the future, new and emerging dose intensive applications in medicine and an increasing demand for international harmonisation, particularly in Europe, will pose new challenges in individual monitoring. (authors)

  6. Basic radiation chemistry for the ionising energy treatment of food

    International Nuclear Information System (INIS)

    Before we can understand the chemistry involved in the irradiation of complex substances such as food we need to have some appreciation of the reactions involved and the products formed when ionising energy interacts with the simple substances such as water and dilute solutions. Reactions involving hydrated electrons, hydrogen atoms and hydroxyl radicals are examined and methods for minimising radiolytic effects in foods are discussed

  7. S.I. No 125 of 2000 Radiological Protection Act 1991 (ionising radiation) Order 2000

    International Nuclear Information System (INIS)

    This statutory instrument provides for the implementation of Council Directive 96/29/Euratom of 13 May 1996 laying down basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionising radiation. It also incorporates the provisions of Council Directive 90/641/Euratom of 4 December 1990 on the operational protection of outside workers exposed to the risk of ionising radiation during their activities in controlled areas. It replaces the provisions of the European Communities (Ionising Radiation) Regulations, 1991 (S.I. No. 43 of 1991), the Radiological Protection Act, 1991 (General Control of Radioactive Substances, Nuclear Devices and Irradiating Apparatus) Order, 1993 (S.I. No. 151 of 1993) and the European Communities (Protection of Outside Workers from Ionising Radiation) Regulations, 1994 (S.I. No. 144 of 1994). The main changes introduced in this Order are: the inclusion of work activities involving exposure to natural sources of radiation, stricter application of existing radiation protection principles through the introduction of lower dose limits, the use of dose constraints in keeping doses as low as reasonably achievable (i.e. optimisation process) and extended application of justification principles, the introduction of radiation protection principles for intervention in cases of radiological emergencies or lasting exposures. (author)

  8. Student and intern awareness of ionising radiation exposure from common diagnostic imaging procedures

    International Nuclear Information System (INIS)

    Full text: This study aims to evaluate medical student and intern awareness of ionising radiation exposure from common diagnostic imaging procedures and to suggest how education could be improved. Fourth to sixth year medical students enrolled at a Western Australian university and interns from three teaching hospitals in Perth were recruited. Participants were asked to complete a questionnaire consisting of 26 questions on their background, knowledge of ionising radiation doses and learning preferences for future teaching on this subject. A total of 331 completed questionnaires were received (95.9%). Of the 17 questions assessing knowledge of ionising radiation, a mean score of 6.0 was obtained by respondents (95% CI 5.8-6.2). Up to 54.8% of respondents underestimated the radiation dose from commonly requested radiological procedures. Respondents (11.3 and 25.5%) incorrectly believed that ultrasound and MRI emit ionising radiation, respectively. Of the four subgroups of respondents, the intern doctor subgroup performed significantly better (mean score 6.9, P< 0.0001, 95% CI 6.5-7.3) than each of the three medical student subgroups. When asked for the preferred method of teaching for future radiation awareness, a combination of lectures, tutorials and workshops was preferred. This study has clearly shown that awareness of ionising radiation from diagnostic imaging is lacking among senior medical students and interns. The results highlight the need for improved education to minimise unnecessary exposure of patients and the community to radiation. Further studies are required to determine the most effective form of education.

  9. Fervent: Chemistry-coupled, ionising and non-ionising radiative feedback in magnetohydrodynamical simulations

    CERN Document Server

    Baczynski, C; Klessen, R S

    2015-01-01

    We introduce a radiative transfer code module for the magnetohydrodynamical adaptive mesh refinement code FLASH 4. It is coupled to an efficient chemical network which explicitly tracks the three hydrogen species H, H_2, H+ as well as C+ and CO. The module is geared towards modeling all relevant thermal feedback processes of massive stars, and is able to follow the non-equilibrium time-dependent thermal and chemical state of the present-day interstellar medium as well as that of dense molecular clouds. We describe in detail the implementation of all relevant thermal stellar feedback mechanisms, i.e. photoelectric, photoionization and H_2 dissociation heating as well as pumping of molecular hydrogen by UV photons. All included radiative feedback processes are extensively tested. We also compare our module to dedicated photon-dominated region (PDR) codes and find good agreement in our modeled hydrogen species once our radiative transfer solution reaches equilibrium. In addition, we show that the implemented rad...

  10. Effect of ionising radiation on Tilapia protein biofilms

    International Nuclear Information System (INIS)

    Full text: Although traditional packaging made from petroleum fractions has an excellent protection for a great number of products, it becomes a serious concern to the environment, as the majority is not biodegradable. New alternatives consider the use of renewable sources as raw material to form films, among them proteins, cellulose derivatives, alginates, pectin, starches, waxes, acylglycerols, fatty acids. Several studies evolving thermal treatment, use of cross-linking agents, adjustment of pH and exposure to radiation were carried out in order to improve the biofilms. Radiation of plastics is a way to induce their cross-linking and to improve considerably their performance. As the cross-linking process changes a linear network into a three dimensional one, consequently it evolves a relevant modification of the characteristics of the material. In fact, a certain degree of anchorage avoids intermolecular movements and makes possible the elastic deformation under stress. Ionizing radiation was demonstrated to be effective to improve the casemates cohesion. When gamma radiation is applied to protein film forming solution it resulted in an improvement in mechanical properties of whey protein films. The radicals formed during radiolysis, specially OH promote a binding between two adjacent tyrosine molecules forming a bityrosine, that is one of other possible mechanisms occurring and responsible for an improvement in a better resistance to tensile strength. Others papers showed the improvement in soy protein films based on physical crosslinking using gamma radiation. By the other side, there is little information using ionizing radiation from electron beam machine in improvements of natural polymers. A radiation modification of starch-based plastic sheets was studied and indicated the tensile strength improved due to the formation of intact network structure. In our country, proteins from animal origin were commercialized at competitive prices comparative to these

  11. The impact of 137Cs ionising radiation on the biological effects of plants

    International Nuclear Information System (INIS)

    Biological effects of exposure to low ionising radiation, especially of long-lasting exposure, have not yet been investigated thoroughly.The goal of this study was to determine internal irradiation doses caused by accumulated 137Cs in test plants and organisms. Environmental exposure of 11 test plant species to 137Cs ionising radiation reached internal irradiation doses of up to 32 micro Sv, which can already cause genotoxic changes in plants sensitive to ionising radiation. Laboratory experiments demonstrated that internal irradiation of the test organism Tradescantia with 0.5 micro Sv of 137Cs was lethal for 25 % of nonviable stamen hairs and for 1.3 % of somatic cells.Under laboratory conditions, negligible internal (0.6-600 micro Sv) and external (40-5500 micro Sv) ionising radiation doses of 137Cs stimulated root growth in Lepidium sativum and reduced the length of the cells nearest to the meristem, but no dose-dependent effect was observed.(author)

  12. International responsability of state by the deleterius effects of ionising radiation

    International Nuclear Information System (INIS)

    International Responsability of State, considering the deleterius effects of ionising radiation on the human being, property, territory and environment which are under other jurisdiction, is focused. Conventional rules, costumary rules, the evolution of ''opinion juris'' as well as the decisions of tribunals related to the subject are analysed. (author)

  13. Code of practice for safety in laboratory - non ionising radiation

    International Nuclear Information System (INIS)

    The code identifies the non-ionizing radiation encountered in laboratories and the associated hazards. The code is intended as a laboratory standard reference document for general information on safety requirements relating to the usage of non-ionizing radiations in laboratories. The nonionizing radiations cover in this code, namely, are ultraviolet radiation, visible light, radio-frequency radiation, lasers, sound waves and ultrasonic radiation. (author)

  14. Influence of ionising radiation on macromolecular components of wheat; possible use in detecting irradiated wheat

    Energy Technology Data Exchange (ETDEWEB)

    Jabir, A.-W.Sh.

    1992-01-01

    The treatment of food by ionising radiation is already permitted by many governments and is under consideration by many others. Cereal are irradiated as a means of disinfestation, this study investigates the effects of such processing on the components of wheat and examines using such radiation induced changes to detect irradiation. Wheat has been irradiated with ionising radiation in the dose range up to 1 kGy. The rheological properties of doughs prepared from this irradiated wheat have been investigated. An immunological assay has been employed to investigate the effect of wheat irradiation on the integrity of gliadin. A method has been developed for the routine isolation of DNA from wheat. Radiation-induced disruption of the DNA double helix has been assessed in DNA extracted from irradiated wheat and calf thymus DNA irradiated in aqueous solution. (author).

  15. The effect of the 1985 Ionising Radiations Regulations on a service inspection company

    International Nuclear Information System (INIS)

    The paper concerns the significant changes and requirements resulting from the 1985 Ionising Radiations Regulations, and examines their effect on the administration and operations of a service inspection company engaging in Industrial Radiography. The major innovations introduced by the 1985 Regulations are discussed under three topic headings: 1) local rules and radiation protection personnel, 2) controlled and supervised areas, and 3) hazard assessments and contingency plans. (U.K.)

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

    International Nuclear Information System (INIS)

    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)

  17. Use of ionising radiation in the teaching of physics and chemistry

    International Nuclear Information System (INIS)

    The guide sets out the safety requirements for using radiation in school education and the principles under which radiation sources may be used without the safety licence referred to in section 16 of the Finnish Radiation Act (592/1991). It covers the use of radiation sources emitting ionizing radiation in comprehensive schools and high schools, and the use of radiation in the teaching of physics and chemistry at vocational training institutions and corresponding educational facilities. The radiation sources used at universities and other institutes of higher education are generally of such high activity and power that their use requires a safety licence. If radiation sources that are exempt from safety licensing are used at universities and other institutes of higher education, then their use may be arranged in accordance with this guide. The guide does not apply to electrically operated appliances generating ionising radiation at a voltage of less than 5000 volts

  18. Process and device for irradiating material with ionising radiation

    International Nuclear Information System (INIS)

    The invention is applied for killing micro-organisms and harmful bodies in medicinal one-way articles with reference to foodstuffs. The purpose of the invention is to make better use of gamma and X-ray radiation with great homogeneousness of dose. This problem is solved by the material taking up a position near to the source of radiation and also a position far from the source of radiation during irradiation. The positions are selected so that the material positioned close to the source of radiation partly shields the peripheral areas of the material positioned far from the source of radiation. The material is irradiated preferably from four sides in each position. (orig.)

  19. Exposure of the French paediatric population to ionising radiation from diagnostic medical procedures in 2010

    International Nuclear Information System (INIS)

    Medical examination is the main source of artificial radiation exposure. Because children present an increased sensitivity to ionising radiation, radiology practices at a national level in paediatrics should be monitored. This study describes the ionising radiation exposure from diagnostic medical examinations of the French paediatric population in 2010. Data on frequency of examinations were provided by the French National Health Insurance through a representative sample including 107,627 children ages 0-15 years. Effective doses for each type of procedure were obtained from the published French literature. Median and mean effective doses were calculated for the studied population. About a third of the children were exposed to at least one examination using ionising radiation in 2010. Conventional radiology, dental exams, CT scans and nuclear medicine and interventional radiology represent respectively 55.3%, 42.3%, 2.1% and 0.3% of the procedures. Children 10-15 years old and babies from birth to 1 year are the most exposed populations, with respectively 1,098 and 734 examinations per 1,000 children per year. Before 1 year of age, chest and pelvis radiographs are the most common imaging tests, 54% and 32%, respectively. Only 1% of the studied population is exposed to CT scan, with 62% of these children exposed to a head-and-neck procedure. The annual median and mean effective doses were respectively 0.03 mSv and 0.7 mSv for the exposed children. This study gives updated reference data on French paediatric exposure to medical ionising radiation that can be used for public health or epidemiological purposes. Paediatric diagnostic use appears much lower than that of the whole French population as estimated in a previous study. (orig.)

  20. Exposure of the French paediatric population to ionising radiation from diagnostic medical procedures in 2010

    Energy Technology Data Exchange (ETDEWEB)

    Etard, Cecile; Aubert, Bernard [Institut de Radioprotection et de Surete Nucleaire, Medical Expertise Unit, Fontenay-aux-Roses (France); Mezzarobba, Myriam [Institut de Radioprotection et de Surete Nucleaire, Laboratory of Epidemiology, Fontenay-aux-Roses (France); Bernier, Marie-Odile [Institut de Radioprotection et de Surete Nucleaire, Laboratory of Epidemiology, Fontenay-aux-Roses (France); Institut de Radioprotection et de Surete Nucleaire, IRSN/PRP-HOM/SRBE/LEPID, Laboratoire d' Epidemiologie, Fontenay-aux-Roses (France)

    2014-12-15

    Medical examination is the main source of artificial radiation exposure. Because children present an increased sensitivity to ionising radiation, radiology practices at a national level in paediatrics should be monitored. This study describes the ionising radiation exposure from diagnostic medical examinations of the French paediatric population in 2010. Data on frequency of examinations were provided by the French National Health Insurance through a representative sample including 107,627 children ages 0-15 years. Effective doses for each type of procedure were obtained from the published French literature. Median and mean effective doses were calculated for the studied population. About a third of the children were exposed to at least one examination using ionising radiation in 2010. Conventional radiology, dental exams, CT scans and nuclear medicine and interventional radiology represent respectively 55.3%, 42.3%, 2.1% and 0.3% of the procedures. Children 10-15 years old and babies from birth to 1 year are the most exposed populations, with respectively 1,098 and 734 examinations per 1,000 children per year. Before 1 year of age, chest and pelvis radiographs are the most common imaging tests, 54% and 32%, respectively. Only 1% of the studied population is exposed to CT scan, with 62% of these children exposed to a head-and-neck procedure. The annual median and mean effective doses were respectively 0.03 mSv and 0.7 mSv for the exposed children. This study gives updated reference data on French paediatric exposure to medical ionising radiation that can be used for public health or epidemiological purposes. Paediatric diagnostic use appears much lower than that of the whole French population as estimated in a previous study. (orig.)

  1. Health protection of persons occupationally exposed to ionising radiation in Croatia

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the health condition of workers occupationally exposed to ionising radiation. The results for 1406 workers exposed to ionising radiations, who were regularly examined in 2004, were analysed using Statistica 5.0. The analysis included workers' case histories, frequency of illnesses and causes of temporary or permanent work disability. Of 1406 workers, 16 (1.13%) were found permanently disabled; in 11 the cause of disability was lens opacity, in 2 persistent trombocitophenia, and in 2 malignant tumour. Twenty-four workers were temporarily disabled, of whom 5 due to pregnancy. Thrombocytopenia was found in 12 men and only one woman. Anaemia was found in 4 women; dicentric chromosomes were the cause of temporary disability in one person, and tuberculosis in one person. Medical examinations of Croatian workers confirm low occupational exposure to ionising radiation. With this type of radiation, the established lens impairments could not be characterised as occupational. The two malignant tumours however were recognised as occupational diseases.(author)

  2. EURADOS strategic research agenda: vision for dosimetry of ionising radiation.

    Science.gov (United States)

    Rühm, W; Fantuzzi, E; Harrison, R; Schuhmacher, H; Vanhavere, F; Alves, J; Bottollier Depois, J F; Fattibene, P; Knežević, Ž; Lopez, M A; Mayer, S; Miljanić, S; Neumaier, S; Olko, P; Stadtmann, H; Tanner, R; Woda, C

    2016-02-01

    Since autumn 2012, the European Radiation Dosimetry Group (EURADOS) has been developing its Strategic Research Agenda (SRA), which is intended to contribute to the identification of future research needs in radiation dosimetry in Europe. The present article summarises-based on input from EURADOS Working Groups (WGs) and Voting Members-five visions in dosimetry and defines key issues in dosimetry research that are considered important for the next decades. The five visions include scientific developments required towards (a) updated fundamental dose concepts and quantities, (b) improved radiation risk estimates deduced from epidemiological cohorts, (c) efficient dose assessment for radiological emergencies, (d) integrated personalised dosimetry in medical applications and (e) improved radiation protection of workers and the public. The SRA of EURADOS will be used as a guideline for future activities of the EURADOS WGs. A detailed version of the SRA can be downloaded as a EURADOS report from the EURADOS website (www.eurados.org). PMID:25752758

  3. The ENEA calibration service for ionising radiations. Part 1: Photons

    International Nuclear Information System (INIS)

    The ENEA (National Agency for New Technology, Energy and the Environment) calibration service for ionizing radiations has been active for 40 years in the secondary standard dosimetry laboratory web. It has been the first center, in 1985, to be acknowledges by the Italian calibration service (SIT) for the two quantities for photons: exposure and air kerma. Since the Institute for the Radiation Protection of ENEA has moved to the new site in Montecuccolino (Bologna, Italy) in 1995, the whole laboratory has been renovated and all irradiation rooms together with radiation source and equipment have been reorganized according to the Χ, γ, β and neutron fields metrology requirements. The aim of this report, as the first part of a report describing all facilities available at the service, is to give a detailed description of all equipment s qualified for photon fields metrology including the secondary standards and the calibration procedures performed for radiation monitoring devices and dosemeters

  4. EURADOS strategic research agenda: vision for dosimetry of ionising radiation

    International Nuclear Information System (INIS)

    Since autumn 2012, the European Radiation Dosimetry Group (EURADOS) has been developing its Strategic Research Agenda (SRA), which is intended to contribute to the identification of future research needs in radiation dosimetry in Europe. The present article summarises-based on input from EURADOS Working Groups (WGs) and Voting Members-five visions in dosimetry and defines key issues in dosimetry research that are considered important for the next decades. The five visions include scientific developments required towards (a) updated fundamental dose concepts and quantities, (b) improved radiation risk estimates deduced from epidemiological cohorts, (c) efficient dose assessment for radiological emergencies, (d) integrated personalised dosimetry in medical applications and (e) improved radiation protection of workers and the public. The SRA of EURADOS will be used as a guideline for future activities of the EURADOS WGs. A detailed version of the SRA can be downloaded as a EURADOS report from the EURADOS web site (www.eurados.org). (authors)

  5. Teaching about radioactivity and ionising radiation: an alternative approach

    International Nuclear Information System (INIS)

    This article reviews children's ideas about radiation and radioactivity and identifies several common areas of misunderstanding. A new approach to teaching the topic at school level, which seeks specifically to address these known difficulties, is then proposed and outlined. (author)

  6. Effects of ionising radiation exposure on plants, fish and mammals: relevant data for environmental radiation protection

    International Nuclear Information System (INIS)

    In order to develop a framework for the assessment of the environmental impact of radiation, it is necessary to establish the relationship between exposure (dose rate, accumulated dose) and the effects that may be induced in plants and animals. With this purpose in mind, the data available on effects induced by ionising radiation in various wildlife groups have been reviewed as part of the FASSET project. This paper has highlighted that the available information on the effects of low dose rate, continuous irradiation (3 μGy h-1) is reasonable for plants, fish and mammals, but is scarce or non-existent for other wildlife groups. Thus, the effects induced in plants, fish and mammals after chronic exposure to radiation are presented in this paper. The fragmentary nature of the available, relevant information has made it very difficult to characterise the desired dose rate-response relationships in any detail. However, it can be broadly concluded that, although minor effects may be seen at lower dose rates in the most sensitive species and systems, the threshold for statistically significant effects in most studies is about 102 μGy h-1. The responses then increase progressively with increasing dose rate and usually become very clear at dose rates>103 μGy h-1 sustained for a large fraction of the lifespan

  7. The combined carcinogenic effects of ionising radiation and chemical molecules

    International Nuclear Information System (INIS)

    Studies of the combined effects of ionizing radiation and chemicals on the incidence of cancer are briefly reviewed. Results (mainly animal data) are presented for the combined effects of; 1) X-radiation and urethane on the incidence of leukaemia and lymphomas; 2) X-radiation and N-N'-2,7 fluorenylenebisacetamide, X-radiation and carbon tetrachloride, neutron radiation and carbon tetrachloride and cerium-144 and DAB on the incidence of cancer of the liver; 3) 131I and methylthiouracil on the incidence of thyroid cancer; and 4) inhaled radon and cigarette smoking, inhaled plutonium and beryllium oxide, inhaled plutonium oxide and benzopyrene, inhaled plutonium and dimethylnitrosamine, and inhaled radon and 5-6 benzoflavone on the incidence of lung cancer. Many of the studies showed that the combined effects of radiation and chemicals had a potentiating effect on tumour formation; there was often a shortening of the latency period before tumour induction and an increase in the size and the malignancy of the tumours. The mechanism of action of these combined effects on tumour incidence are considered. (UK)

  8. The design of a calorimetric standard of ionising radiation absorbed dose

    International Nuclear Information System (INIS)

    The design of a calorimetric working standard of ionising radiation absorbed dose is discussed. A brief history of the appropriate quantities and units of measurement is given. Detailed design considerations follow a summary of the relevant literature. The methods to be used to relate results to national standards of measurement are indicated, including the need for various correction factors. A status report is given on the construction and testing program

  9. The philosophy and assumptions underlying exposure limits for ionising radiation, inorganic lead, asbestos and noise

    International Nuclear Information System (INIS)

    Full text: A review of the literature relating to exposure to, and exposure limits for, ionising radiation, inorganic lead, asbestos and noise was undertaken. The four hazards were chosen because they were insidious and ubiquitous, were potential hazards in both occupational and environmental settings and had early and late effects depending on dose and dose rate. For all four hazards, the effect of the hazard was enhanced by other exposures such as smoking or organic solvents. In the cases of inorganic lead and noise, there were documented health effects which affected a significant percentage of the exposed populations at or below the [effective] exposure limits. This was not the case for ionising radiation and asbestos. None of the exposure limits considered exposure to multiple mutagens/carcinogens in the calculation of risk. Ionising radiation was the only one of the hazards to have a model of all likely exposures, occupational, environmental and medical, as the basis for the exposure limits. The other three considered occupational exposure in isolation from environmental exposure. Inorganic lead and noise had economic considerations underlying the exposure limits and the exposure limits for asbestos were based on the current limit of detection. All four hazards had many variables associated with exposure, including idiosyncratic factors, that made modelling the risk very complex. The scientific idea of a time weighted average based on an eight hour day, and forty hour week on which the exposure limits for lead, asbestos and noise were based was underpinned by neither empirical evidence or scientific hypothesis. The methodology of the ACGIH in the setting of limits later brought into law, may have been unduly influenced by the industries most closely affected by those limits. Measuring exposure over part of an eight hour day and extrapolating to model exposure over the longer term is not the most effective way to model exposure. The statistical techniques used

  10. Computer modeling and experimental work on the astrobiological implications of the martian subsurface ionising radiation environment

    OpenAIRE

    Dartnell, L. R.

    2008-01-01

    Any microbial life extant in the top meters of the martian subsurface is likely to be held dormant for long periods of time by the current permafrost conditions. In this potential habitable zone, a major environmental hazard is the ionising radiation field generated by the flux of exogenous energetic particles: solar energetic protons and galactic cosmic rays. The research reported here constitutes the first multidisciplinary approach to assessing the astrobiological impact of ...

  11. An isotope view on ionising radiation as a source of sulphuric acid

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker; Bork, Nicolai Christian; Hattori, S.;

    2012-01-01

    Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a miss...... yields of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV) to S(VI) conversion....

  12. An isotopic analysis of ionising radiation as a source of sulphuric acid

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker; Bork, Nicolai Christian; Hattori, S.;

    2012-01-01

    Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a miss...... of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV) to S(VI) conversion....

  13. Non-targeted effects of ionising radiation. Proceedings of the RISC-RAD specialised training course

    International Nuclear Information System (INIS)

    The training course 'Non-targeted effects of ionising radiation' took place at the STUK, Radiation and Nuclear Safety Authority, Helsinki, Finland 14-16 February 2005. Proceeding of this course is collected in this volume. The idea of the course was to convene a number of scientists leading in the area of non-targeted effects of ionising radiation with the aim to outline their visions for the role of these effects and outline the future directions of radiation research on the basis of their expertise. The course was supported by the RISC-RAD IP FI6R-CT-2003-508842, Euratom specific programme for research and training on nuclear energy, 6th FP of the EC. The main objectives of the training course were: (1) to clarify the mechanisms of non-targeted effects, in particular, bystander effects, genomic instability and adaptive response; (2) to look if and how non-targeted effects modulate the cancer risk in the low dose region, and whether they relate to protective or harmful functions; (3) to clarify if ionising radiation can cause non-cancer diseases or beneficial effects at low and intermediate doses; (4) address the issue of individual susceptibility and other factors modifying non-targeted responses; (5) attempt to assess the relevance of non-targeted effects for radiation protection and to set the scientific basis for a modern, more realistic, radiation safety system; (6) and finally to contribute to the conceptualisation of a new paradigm in radiation biology that would cover both the classical direct (DNA-targeted) and non-targeted (indirect) effects

  14. Ionising radiations, radioactive materials and the fire services

    International Nuclear Information System (INIS)

    Extensive experience has shown that ionizing radiations and radioactive materials can be used safely in a wide variety of applications, provided a number of precautions are implemented. Transport of radioactive materials is common and regulations designed to ensure safety in such transport have resulted in an excellent safety record. Pre-planning for fire situations in buildings where radioactive materials are known to be present is very desirable. An Australian Standard, AS2243, recommends that Station Officers of the local fire brigade be appraised of the hazards and the need to take particular care in areas marked with ionizing radiation warning signs

  15. Biological effects of low doses of ionising radiation

    International Nuclear Information System (INIS)

    A study was performed with the aim to examine whether the progeny of cells that had been repeatedly irradiated with low doses of gamma rays will change their sensitivity to cytotoxic agents. Four mammalian cell lines were used in the experiment. It was found that the progeny of cells irradiated in this way do not change their sensitivity to gamma rays but would change their sensitivity to various cytostatics drugs. (A.K.)

  16. Martian sub-surface ionising radiation: biosignatures and geology

    Directory of Open Access Journals (Sweden)

    L. R. Dartnell

    2007-02-01

    Full Text Available The surface of Mars, unshielded by thick atmosphere or global magnetic field, is exposed to high levels of cosmic radiation. This ionizing radiation field is deleterious to the survival of dormant cells or spores and the persistence of molecular biomarkers in the subsurface, and so its characterisation is of prime astrobiological interest. Previous research has attempted to address the question of biomarker persistence by inappropriately using dose profiles weighted specifically for cellular survival. Here, we present modelling results of the unmodified physically absorbed radiation dose as a function of depth through the Martian subsurface. A second major implementation of this dose accumulation rate data is in application of the optically stimulated luminescence technique for dating Martian sediments.

    We present calculations of the dose-depth profile from galactic cosmic rays in the Martian subsurface for various scenarios: variations of surface composition (dry regolith, ice, layered permafrost, solar minimum and maximum conditions, locations of different elevation (Olympus Mons, Hellas basin, datum altitude, and increasing atmospheric thickness over geological history. We also model the changing composition of the subsurface radiation field with depth compared between Martian locations with different shielding material, determine the relative dose contributions from primaries of different energies, and briefly treat particle deflection by the crustal magnetic fields.

  17. Non-targeted effects of ionising radiation and radiotherapy.

    Science.gov (United States)

    Sjostedt, Svetlana; Bezak, Eva

    2010-09-01

    Modern radiobiology is undergoing rapid change due to new discoveries contradicting the target concept which is currently used to predict dose-response relationships. Thus relatively recently discovered radiation-induced bystander effects (RIBEs), that include additional death, mutation and radio-adaptation in non-irradiated cells, change our understanding of the target concept and broadens its boundaries. This can be significant from a radioprotection point of view and also has the potential to reassess radiation damage models currently used in radiotherapy. This article reviews briefly the general concepts of RIBEs such as the proposed underlying mechanisms of signal induction and propagation, experimental approaches and biological end points used to investigate these phenomena. It also summarises several mathematical models currently proposed in an attempt to quantify RIBE. The main emphasis of this article is to review and highlight the potential impact of the bystander phenomena in radiotherapy. PMID:20857259

  18. The ionising radiation effect on reactivation of antibiotics

    International Nuclear Information System (INIS)

    The effect of gamma-radiation on the molecular structure of antibiotics was studied with a view to extending their useful life beyond the current expiration period. The following antibiotics were examined: penicillin, bicillin-3,5, streptomycine, and ampioxe. The samples were irradiated by Co-60 gamma-radiation from a research irradiator. Doses of 0.1, 1, 5, 7, and 10 Gy were applied. The processes were elucidated using the classical method of 2-divisible serial dilutions and IR-spectroscopy. All the measurements were carried out at 300 K. The IR-spectra revealed that the chemical structure of new and old antibiotics is identical; the change in the antibiotic activity is generally a result of deformation of the molecule or change in its conformation; the reactivation process returns the molecule to its previous state and the activity of antibiotic after reactivation meets established standards. Hence, this method can be used for the reactivation of expired antibiotics

  19. Non-Targeted effects of ionising radiation and radiotherapy

    International Nuclear Information System (INIS)

    Full text: Modern radiobiology is undergoing rapid change due to new discoveries contradicting the target concept which is currently used to predict dose-response relationships. Thus relatively recently discovered radiation induced bystander effects (RlBEs), that include additional death, mutation and radio-adaptation in non-irradiated cells, change our understanding of the target concept and broadens its boundaries. This can be significant from a radioprotection point of view and also has the potential to reassess radiation damage models currently used in radiotherapy. This article reviews briefly the general concepts of RlBEs such as the proposed underlying mechanisms of signal induction and propagation, experimental approaches and biological end points used to investigate these phenomena. It also summ rises several mathematical models currently proposed in an attempt to quantify RlBE. The main emphasis of this al1icle is to review and highlight the potential impact of the bystander phenomena in radiotherapy.

  20. The non ionizing radiations; Les rayonnements non ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Vecchia, P. [Institut National de la Sante, Lab. de Physique, Rome (Italy); Souques, M. [Electricite de France (EDF), Service des Etudes Medicales, 75 - Paris (France); Lambrozo, J. [EDF/GDF, Service des Etudes Medicales, 75 - Paris (France)] [and others

    2003-07-01

    The biological effects of non ionizing radiations are studied in this part. The magnetic fields and the cardiac implants, melatonin secretion among the electricians exposed to magnetic fields of 50 hz, the effects of electromagnetic fields in professional medium, evaluation of the effect of an exposure to a signal of a mobile phone (GSM 900) on the skin are the different subjects discussed. (N.C.)

  1. Cataract and ionizing radiation; Cataracte et rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Wassilieff, S. [Ecole des Applications Militaires de l' Energie Atomique, 50 - Cherbourg Octeville (France)

    2009-10-15

    The radiation-induced cataract has been up to now considered as a quite rare pathology, needing high-dose radiations (beyond a dose threshold roughly estimated at 2 Grays to the lens) consisting mainly in head tumour radiotherapy complications. Several new studies on different exposed populations such as astronauts, japanese atomic bomb survivors, people undergoing X-ray examinations, Chernobyl accident 'liquidators' as well as data from animal experiments, suggest that dose threshold for detectable opacities as well as for clinical posterior sub-capsular cataract occurring, might be far lower than those previously assumed. Even the existence of a dose threshold is no longer an absolute certitude insofar as radiation-induced cataract pathogenesis might consist not really in a deterministic effect (direct tissue harmful effect, killing or seriously injuring a critical population of cells) as believed until now, but rather in a stochastic effect (genomic damage in target-cells, altered cell division, abnormal lens fiber cell differentiation). More practically, these new data may lead us to reconsider radioprotection of specifically exposed populations: mainly patients and workers. Regarding workers, labour legislation (lens equivalent dose limit of 150 mSv during 12 consecutive months) might be, in the medium term, reassessed downwards. (author)

  2. Exposure to low dose ionising radiation: Molecular and clinical consequences.

    LENUS (Irish Health Repository)

    Martin, Lynn M

    2014-07-10

    This review article provides a comprehensive overview of the experimental data detailing the incidence, mechanism and significance of low dose hyper-radiosensitivity (HRS). Important discoveries gained from past and present studies are mapped and highlighted to illustrate the pathway to our current understanding of HRS and the impact of HRS on the cellular response to radiation in mammalian cells. Particular attention is paid to the balance of evidence suggesting a role for DNA repair processes in the response, evidence suggesting a role for the cell cycle checkpoint processes, and evidence investigating the clinical implications\\/relevance of the effect.

  3. Non-stochastic effects of ionising radiations on gonads

    International Nuclear Information System (INIS)

    Fractionated gonad doses of 0.35 Gy cause marked temporary reduction in sperm count; fractionated ovarian doses up to 1.5 Gy have no apparent effect in women aged 20 to 30. Single testicular doses of 0.5 to 3 Gy cause aspermia; return to pre-irradiation sperm counts occurs about 30 months after single doses of 2 and 3 Gy. The ovary also has a recovery capacity, particularly in women under 40. Type B spermatogonia are the most radiosensitive germ cells for cell killing. Later stages are more radioresistant, forming a transient population in the total male reproductive life. Following radiation-induced sterilisation, fertility is restored if enough spermatogonia survive to repopulate the seminiferous tubules. Radiation effects on female fertility are explained on the basis of reduction in a fixed oocyte pool. Doses needed to induce artificial menopause are higher in younger women because their ovaries contain larger oocyte numbers. Particular fractionation regimes decrease the threshold dose for permanent male sterility. It has been inferred that human testes could tolerate 1 mGy per day indefinitely without fertility impairment. In female experimental mammals, fractionation reduces fertility damage. Fractionation may also have a protective effect on the human ovary, depending on age and total dose. (U.K.)

  4. Occupational exposure to external ionising radiation in Poland, 1999

    International Nuclear Information System (INIS)

    In 1999 about 6208 radiation workers from 389 departments were monitored by CLOR in Poland. The distribution of annual personal doses shows that 85% of controlled workers received doses below the MDL (0.4 mSv) and about 97% controlled workers received doses below 5 mSv. Doses higher than 50 mSv were received by three operators of industrial radiography units. The radiation workers under control are divided into four main work sectors: nuclear industry, research and education, medicine, and general industry. The average annual dose for all workers in each particular sector was 0.22 mSv, 0.22 mSv, 0.30 mSv and 0.80 mSv, respectively. The average annual dose for the entire monitored population was 0.47 mSv. The average annual dose in each particular sector for number of workers receiving E>0, i.e. Hp(10) (0.4 mSv, amounted to 1.78 mSv, 2.03 mSv, 1.88 mSv and 4.85 mSv, respectively. The average annual dose for the full number of workers receiving E>0 was 3.21 mSv. This paper contains the detailed analysis of occupational exposure. The distributions of annual occupational exposure in different work sectors are also given. (author)

  5. Dosimetry Methods for Human Exposure to Non-Ionising Radiation

    International Nuclear Information System (INIS)

    The paper deals with human exposure to electromagnetic fields from extremely low frequencies (ELF) to GSM frequencies. The problem requires (1) the assessment of external field generated by electromagnetic interference (EMI) source at a given frequency (incident field dosimetry) and then (2) the assessment of corresponding fields induced inside the human body (internal field dosimetry). Several methods used in theoretical and experimental dosimetry are discussed within this work. Theoretical dosimetry models at low frequencies are based on quasistatic approaches, while analyses at higher frequencies use the full-wave models. Experimental techniques involve near and far field measurement. Human exposure to power lines, transformer substations, power line communication (PLC) systems, Radio Frequency Identification (RFID) antennas and GSM base station antenna systems is analyzed. The results o are compared to the exposure limits proposed by relevant safety guidelines. Theoretical incident dosimetry used in this paper is based on the set of Pocklington integro-differential equations for the calculation of the current distribution and subsequently radiated field from power lines. Experimental incident dosimetry techniques involve measurement techniques of fields radiated by RFID antennas and GSM base station antennas. First example set of numerical results is related to the internal dosimetry of realistic well-grounded body model exposed to vertical component of the electric field E = 10 kV/m generated by high voltage power line. The results obtained via the HNA model exceed the ICNIRP basic restrictions for public exposure (2 mA/m2) in knee (8.6 mA/m2) and neck (9.8 mA/m2) and for occupational exposure (10 mA/m2) in ankle (32 mA/m2). In the case of a conceptual model of a realistic human body inside a transformer substation room touching a control panel at the potential φ0 = 400 V and with two scenarios for dry-air between worker's hand and panel, the values of

  6. Ultrastructural effects of ionising radiation on primary cultures of rainbow trout skin

    International Nuclear Information System (INIS)

    Full text: There are few reports on the comparative effects of ionising radiation on different species. Published data report the use of radiation levels far in excess of what could be considered in an environmental context and are therefore difficult to assimilate into environmental research. We are engaged in a comparative study of the cellular effects of non-lethal radiation doses on tissue explants from fish and aquatic invertebrates. The aim of the present work is to investigate the ultrastructural effects of ionising radiation on primary cultures of skin from the rainbow trout. Primary cultures were grown using tissue explants from rainbow trout skin. The cultures were irradiated with doses of cobalt 60 gamma radiation ranging from 0.5Gy to 15Gy. The cultures were fixed in glutaraldehyde, at 7 days post irradiation. They were then post-fixed in osmium tetroxide and dehydrated in ascending grades of alcohol before being embedded in Epon. Blocks of tissue were then sectioned at 1 μm, stained with toluidine blue and surveyed using light microscopy. Ultra-thin sections of particular areas were cut at 50nm and examined by electron microscopy. Nuclear aberrations and changes in cytoplasmic organelles particularly mitochondria, were observed in irradiated skin cultures. Mitochondria were also of a different shape in irradiated cultures. The occurrence of apoptotic bodies in the irradiated cultures suggests that of controlled cell death is involved in the cellular response to radiation. These results may have important considerations for environmental protection. (author)

  7. Effect of ionising radiation exposure on structure and permeability of epithelial junctions in rat ileum

    International Nuclear Information System (INIS)

    Exposure of the digestive tract to ionising radiation results in both morphological and functional alterations of the small intestine. However little is known about the effect of irradiation on the junctions playing a major role in the maintenance of epithelial barrier integrity. Thus the aim of this study was to investigate, in rat ileum, the effect of radiation exposure on the permeability of the epithelial barrier in parallel with the localization of certain inter- and intra-cellular proteins of tight and adherent junctions

  8. Combined effects of ionising gamma radiation and some chemical substances on the Allium sativum growth

    International Nuclear Information System (INIS)

    Co 60 - gamma ionising radiations act in different doses and flows on Allium sativum. They accelerate the germination of bulblets with a couple of days by comparison with the sample. The 10 Gy dose stimulates the plants growth. The 30 Gy dose or 'shock dose' related to the radiation flow and with chemicals used in the treatment, produces strong decays or raises of biological parameter values. The growth region which is implied in growing regulators synthesis is perturbed. The calculation of nuclear and cytoplasmic volumes of nucleus-cytoplasm ratio confirms the perturbation at this level. (Author)

  9. Folic acid deficiency increases sensitivity to genome damage by ionising radiation

    International Nuclear Information System (INIS)

    Folic acid deficiency can lead to uracil misincorporation and disable DNA repair, by decreasing thymidine concentration. It is hypothesized that folic acid is an important micronutrient in the prevention of chromosome damage induced by gamma-irradiation. In this study the impact of folic acid deficiency on the chromosome damage and chromosome 21 aneuploidy by gamma-radiation was determined using the cytokinesis-block micronucleus assay in long term WIL2-NS cultures in cell culture medium with 4 different folic acid concentrations (0.2 nM, 2 nM, 20 nM and 200 nM). The study showed a significant increase of 55.5% in micronucleus frequency with decreasing folic acid concentration (P < 0.0001). Additionally, there was a significant difference of 46.5% and 50.1% in micronucleus frequency and of nucleoplasmic bridge frequency, respectively, between the control and irradiated (1.5 Gy) group (P < 0.05). Folic acid deficiency caused an increase of 51.7% in micronucleus frequency (P < 0.0001) and of 7.1% nucleoplasmic bridge frequency (P = 0.0280) in irradiated cultures when compared to irradiated folic acid replete cultures. Folic acid deficiency and gamma-radiation were shown to have a significant interactive effect on micronucleus frequency (Two-way ANOVA, P < 0.0001). Apoptosis and necrosis were increased by folic acid deficiency but they were not significantly altered by ionising radiation exposure. Chromosome 21 aneuploidy was significantly increased (P <0.05) by folic acid deficiency but not by ionising radiation and there was no significant interaction between these two factors. The results show that folic acid deficiency induces chromosome 21 aneuploidy by non-disjunction as well as inducing chromosome breaks and chromosome rearrangements. In conclusion, folic acid deficiency interacts significantly with ionising radiation in inducing chromosome damage that leads to the formation of micronuclei (e.g. chromosome breaks and chromosome loss)

  10. Evaluating the effects of ionising radiation upon the environment

    International Nuclear Information System (INIS)

    As a result of several recent initiatives, there is now a reasonably well-established international appreciation of the need to evaluate the effects of radiation on the natural environment in a more explicit and comprehensive manner. This need derives not only from what are seen as the inadequacies that result from simply assuring the protection of human beings, but also from a need to satisfy the broader ethical, social, and various forms of legal requirements for the demonstration of adequate environmental protection. In this respect, therefore, because a very wide and disparate range of such requirements already exists, and are likely to continue to arise, it is important to try and maintain some sort of clarity about the different objectives that one might be trying to achieve in any environmental protection evaluation exercise, and how best to achieve them. The presence - or even the risk of the presence - of radionuclides in the environment as a result of human activity is a very emotive subject, and is likely to remain so. It is therefore all the more important for the 'protection' of the environment to be based upon a set of international protocols, and standardised procedures and data bases - as has been the case for the protection of man - that are free from political interference or pressure, either in relation to national bodies or to specific pressure groups. In this regard, suggestions have already been made for the establishment of a 'system of protection' that would parallel, and indeed could be combined with, the 'system' that has been developed to protect human beings under different circumstances from different sources of radiation. This suggestion has been supported by the IUR, and the concept is being actively researched for regional application in Europe and the Arctic as well as at a national level, and has been discussed by an ICRP Task Group. This paper therefore attempts to explore some of the means by which the elements of such a system

  11. Cytogenetic monitoring of nuclear workers occupationally exposed to ionising radiation

    International Nuclear Information System (INIS)

    Chromosome aberration (CA) analysis using Giemsa techniques was performed in blood lymphocytes of 84 nuclear workers with cumulative doses of 1-632 mSv during employment periods of 1-25 y. The control group comprised 82 healthy male donors. An estimated CA frequency in the total radiation-exposed group was significantly higher when compared with the controls (2.27 vs. 1.76 CA/100 cells, p 0.05). However, significant increase in the total CA frequency was determined in workers with additional internal exposure (2.54 CA/100 cells, p < 0.05) and those with registered neutron doses (2.95 CA/100 cells, p < 0.01). No correlation was found between CA frequency and occupational exposure dose. Borderline significant correlation was found between duration of employment and total CA (r = 0.218, p = 0.046, Fig. 2) and chromosome-type aberration (r = 0.265, p = 0.015) frequency. (authors)

  12. Brain Radiation Information Data Exchange (BRIDE): integration of experimental data from low-dose ionising radiation research for pathway discovery

    OpenAIRE

    Karapiperis, Christos; Kempf, Stefan J.; Quintens, Roel; Azimzadeh, Omid; Vidal, Victoria Linares; Pazzaglia, Simonetta; Bazyka, Dimitry; Mastroberardino, Pier G.; Scouras, Zacharias G.; Tapio, Soile; BENOTMANE, MOHAMMED ABDERRAFI; Ouzounis, Christos A

    2016-01-01

    Background The underlying molecular processes representing stress responses to low-dose ionising radiation (LDIR) in mammals are just beginning to be understood. In particular, LDIR effects on the brain and their possible association with neurodegenerative disease are currently being explored using omics technologies. Results We describe a light-weight approach for the storage, analysis and distribution of relevant LDIR omics datasets. The data integration platform, called BRIDE, contains inf...

  13. Diagnostic medical exposures. Advice on exposure to ionising radiation during pregnancy

    International Nuclear Information System (INIS)

    The main objective of NRPB advice concerning in utero exposures to ionising radiations is 'to prevent unnecessary exposure of the fetus when medical diagnostic procedures involving ionising radiations are indicated during pregnancy'. In addition, advice is meant to help to avoid unnecessary concern or action if an exposure does occur. NRPB issued ASP8 (Exposure to ionising radiation of pregnant women: advice on the diagnostic exposure of women who are, or who may be, pregnant) in 1985. This advice suggested that there would be no risks to the concepts following irradiation during the first 10 days of the menstrual cycle and that subsequent risks in the remainder of the first 4 week period would be likely to be so small that no special limitation on exposure was required - sometimes known as 'the 28-day rule'. In 1993, NRPB published further advice to replace ASP8 in the Documents of the NRPB series, in Volume 4, No 4 - henceforth referred to as Doc NRPB 4(4)2 - which drew upon data published since 1985. The more recent data suggest that risks in the interval between 10 days and the date at which the next menstrual period is due, although still small for most diagnostic procedures, may be significant for higher dose procedures. Consequently, it is considered there is a need to operate a modified policy for such higher dose procedures. This pocket publication has been produced to present in a concise and user-friendly format the basis of the most recent NRPB advice and to provide a guide for the implementation of that advice in the everyday practice of diagnostic radiology. The opportunity has also been taken to provide the most up to date data on doses in the UK. This publication is split into three parts: an introduction to the terms used in the document, a practical guide to implementation of the advice, and the scientific background to the advice

  14. The low dose gamma ionising radiation impact upon cooperativity of androgen-specific proteins

    International Nuclear Information System (INIS)

    The paper deals with effects of the ionising radiation (γ-IR, 0.5 Gy) upon serum testosterone (T), characteristics of testosterone-binding globulin (TeBG) and androgen receptor (AR) in parallel with observation of androgen (A) responsive enzyme activity – hexokinase (HK). The interdependence or relationships of T-levels with parameters of the proteins that provide androgenic regulation are consequently analyzed in post-IR dynamics. The IR-stress adjustment data reveal expediency of TeBG- and AR-cooperativity measurements for more precise assessments of endocrine A-control at appropriate emergencies

  15. Relations between age at occupational exposure to ionising radiation and cancer risk.

    OpenAIRE

    Stewart, A. M.; Kneale, G. W.

    1996-01-01

    OBJECTIVES: To discover how the age when a given dose of ionising radiation is received (exposure age) affects the subsequent cancer risk, and whether the types of cancer caused by repeated exposure to small doses during adult life differ from naturally occurring cancers at that age. METHOD: A nested case-control design with all possible controls in a cohort of nuclear workers, and a Mantel-Haenszel test (requiring only one degree of freedom) to discover whether there was any level of exposur...

  16. A digital interface for preset time or voltage measurements using an ionising radiation dosemeter

    International Nuclear Information System (INIS)

    A digital interface circuit has been built to terminate charge collection measurements made with an ionising radiation dosemeter. A compact portable measurement system has been assembled, comprising a digital voltmeter, a period timer and the digital interface module. Digital signals from both the voltmeter and the timer are compared with separate preset limits, and the dosemeter measurement is terminated when one of these limits is reached. The operation of the dosemeter is outlined, and the interface circuit is described in detail. Modifications to the voltmeter and timer are described, and comprehensive users' instructions are given

  17. Glioblastoma stem cells: radiobiological response to ionising radiations of different qualities

    International Nuclear Information System (INIS)

    Glioblastoma multiform (GBM) is the most common and malignant primary brain tumour, with very poor prognosis. The high recurrence rate and failure of conventional treatments are expected to be related to the presence of radio-resistant cancer stem cells (CSCs) inside the tumour mass. CSCs can both self-renew and differentiate into the heterogeneous lineages of cancer cells. Recent evidence showed a higher effectiveness of C-ions and protons in inactivating CSCs, suggesting a potential advantage of Hadrontherapy compared with conventional radiotherapy for GBM treatment. To investigate the mechanisms involved in the molecular and cellular responses of CSCs to ionising radiations, two GBM stem cell (GSC) lines, named lines 1 and 83, which were derived from patients with different clinical outcomes and having different metabolic profiles (as shown by NMR spectroscopy), were irradiated with 137Cs photons and with protons or C-ions of 62 MeV u-1 in the dose range of 5- 40 Gy. The biological effects investigated were: cell death, cell cycle progression, and DNA damage induction and repair. Preliminary results show a different response to ionising radiation between the two GSC lines for the different end points investigated. Further experiments are in progress to consolidate the data and to get more insights on the influence of radiation quality. (authors)

  18. Glioblastoma stem cells: radiobiological response to ionising radiations of different qualities.

    Science.gov (United States)

    Pecchia, I; Dini, V; Ricci-Vitiani, L; Biffoni, M; Balduzzi, M; Fratini, E; Belli, M; Campa, A; Esposito, G; Cirrone, G; Romano, F; Stancampiano, C; Pelacchi, F; Pallini, R; Tabocchini, M A

    2015-09-01

    Glioblastoma multiforme (GBM) is the most common and malignant primary brain tumour, with very poor prognosis. The high recurrence rate and failure of conventional treatments are expected to be related to the presence of radio-resistant cancer stem cells (CSCs) inside the tumour mass. CSCs can both self-renew and differentiate into the heterogeneous lineages of cancer cells. Recent evidence showed a higher effectiveness of C-ions and protons in inactivating CSCs, suggesting a potential advantage of Hadrontherapy compared with conventional radiotherapy for GBM treatment. To investigate the mechanisms involved in the molecular and cellular responses of CSCs to ionising radiations, two GBM stem cell (GSC) lines, named lines 1 and 83, which were derived from patients with different clinical outcomes and having different metabolic profiles (as shown by NMR spectroscopy), were irradiated with (137)Cs photons and with protons or C-ions of 62 MeV u(-1) in the dose range of 5-40 Gy. The biological effects investigated were: cell death, cell cycle progression, and DNA damage induction and repair. Preliminary results show a different response to ionising radiation between the two GSC lines for the different end points investigated. Further experiments are in progress to consolidate the data and to get more insights on the influence of radiation quality. PMID:25969527

  19. Adaptive response to ionising radiation induced by cadmium in zebrafish embryos

    International Nuclear Information System (INIS)

    An adaptive response is a biological response where the exposure of cells or animals to a low priming exposure induces mechanisms that protect the cells or animals against the detrimental effects of a subsequent larger challenging exposure. In realistic environmental situations, living organisms can be exposed to a mixture of stressors, and the resultant effects due to such exposures are referred to as multiple stressor effects. In the present work we demonstrated, via quantification of apoptosis in the embryos, that embryos of the zebrafish (Danio rerio) subjected to a priming exposure provided by one environmental stressor (cadmium in micromolar concentrations) could undergo an adaptive response against a subsequent challenging exposure provided by another environmental stressor (alpha particles). We concluded that zebrafish embryos treated with 1 to 10 μM Cd at 5 h postfertilisation (hpf) for both 1 and 5 h could undergo an adaptive response against subsequent ∼4.4 mGy alpha-particle irradiation at 10 hpf, which could be interpreted as an antagonistic multiple stressor effect between Cd and ionising radiation. The zebrafish has become a popular vertebrate model for studying the in vivo response to ionising radiation. As such, our results suggested that multiple stressor effects should be carefully considered for human radiation risk assessment since the risk may be perturbed by another environmental stressor such as a heavy metal. (paper)

  20. Non-targeted effects of ionising radiation (NOTE) - European Integrated project, 2006-2010

    International Nuclear Information System (INIS)

    The general objectives of the NOTE project are: (1) to investigate the mechanisms of non-targeted effects, in particular, bystander effects, genomic instability and adaptive response; (2) to investigate if and how non-targeted effects modulate the cancer risk in the low dose region, and whether they relate to protective or harmful functions; (3) to investigate if ionising radiation can cause non-cancer diseases or beneficial effects at low and intermediate doses; (4) to investigate individual susceptibility and other factors modifying non-targeted responses; (5) to assess the relevance of non-targeted effects for radiation protection and to set the scientific basis for a modern, more realistic, radiation safety system; (6) to contribute to the conceptualisation of a new paradigm in radiation biology that would cover both the classical direct (DNA-targeted) and non-targeted (indirect) effects. The NOTE brings together 20 major European and Canadian groups involved in the discovery, characterisation and mechanistic investigation of non-targeted effects of ionising radiation in cellular, tissue and animal models. The NOTE research activities are organised in six work packages. Four work packages (WPs 2-5) are problem-oriented, focussing on major questions relevant for the scientific basis of the system of radiation protection: WP2 Mechanisms of non-targeted effects, WP3 Non-cancer diseases, WP4 Factors modifying non-targeted responses, WP5 Modelling of non-targeted effects. The integration activities provided by WP6 strengthen the collaboration by supporting the access to infrastructures, mobility and training. WP7 provides dissemination and exploitation activities in the form of workshops and a public website. Managerial activities (WP1) ensure the organisation and structures for decision making, monitoring of progress, knowledge management and efficient flow of information and financing. Progress of the first two years of the project is described in this paper

  1. External dosimetry for ionising radiation. From the national standard to the users in radiotherapy and radiation protection

    International Nuclear Information System (INIS)

    This report presents a review of the external dosimetry of the ionising radiations for the protection of the human being. Looking at this topic, at first we are confronted with its diversity: the protection of the workers and the public against radiations, the medical exposures for radiotherapy, diagnosis and surgery, and the accidental situations. These aspects are often artificially separated so that the global comprehension becomes more difficult. We underline the points of convergence and the bonds which exist between the concepts of dosimetry adopted to deal with its different aspects. It also appeared useful to avoid proposing a dictionary of definitions copied in the reports of the international commissions, and adopting the formalism of the ICRU reports. This is why the definitions, when they are essential, are put in appendix. This text presents the reasons which led to the adoption of the system of quantity used today for the external dosimetry of the ionising radiations. After an introduction dealing with the general principle, the first chapter deals with the 'physical' quantities and the methods used for the determination of the national references. The second chapter, through the protection against radiation of the workers and the public, describes the bonds between the measurable 'operational' quantities and the non measurable 'protections' quantities which allow establishing the radiation protection limits and check that they are respected. The third chapter deals with the difficulties encountered for the measurements in area and personal dosimetry. The fourth chapter deals with the specificities of the medical exposures with the 'practical' quantities, the principle of optimisation and how radiotherapy is implemented. The fifth chapter briefly describes the case of the concerted exposures and of the accident. In conclusion, we analyse the needs and some potential new avenues of work for the metrology of the ionising radiations. (author)

  2. Cytogenetic studies on the effect of ionising radiation by solid-stain and FISH techniques

    International Nuclear Information System (INIS)

    Full text: The effect of overexposures to very low doses of ionising radiation (IR) have been analysed to evaluate the basal frequency of aberrations using conventional solid-stain and FISH painting techniques. In these studies a significantly higher background frequency respect to a control group was only observed for acentric fragments. For translocations FISH detected, in spite of an slight increase in the exposed population, no significant differences were observed. This result is related to the wide range in the basal frequency of translocations, that contrasts with the reported observations for dicentrics. The implications in bio-dosimetry studies using translocations is discussed. Other studies carried out to evaluate the effect of low dose exposures have been focussed to evaluate the existence of an adaptive response induced by occupational exposures. For this reason lymphocyte treatments in G0 with IR and in G2 with bleomycin have been studied. In these studies significant lower frequencies, in the occupationally exposed group respect to controls, were observed for dicentrics and chromatid breaks respectively. Implications on the inter-individual susceptibility to clastogenic agents, and implications on the bio-dosimetry studies are discussed. Before the elaboration of dose-effect curves using FISH painting techniques, it was analysed the relative chromosome involvement in the radio-induced chromosome aberrations. For this purpose samples from a female and a male were irradiated at 3 and 5 Gy respectively, in both experiments chromosomes were analysed one by one independently. The results indicated that smaller chromosomes are more involved and larger less than expected due to their relative DNA content. Taking into account these results and the different chromosome morphology, to obtain calibration data using FISH techniques, chromosomes 1, 4 and 11 were selected. The coefficients obtained are similar with those obtained by solid stained dicentric

  3. Occupational external exposure to ionising radiation in France (2005-2011)

    International Nuclear Information System (INIS)

    The Institute for Radiological Protection and Nuclear Safety (IRSN) produces the French annual report on occupational exposure to ionising radiation, collecting all national data and aggregating the results according to a unique activity classification expected to be shared by all involved in personal dosimetric monitoring (employers, external dosimetry services and IRSN). Nearly 344 000 monitored workers were counted in France in 2011, with a collective dose of 64.24 man.Sv. The average annual dose (as calculated over the number of measurably exposed workers) differed among the main activity fields: 0.54 mSv in medical and veterinary activities, 1.18 mSv in the nuclear field, 1.60 mSv in non-nuclear industry and 0.47 mSv in research activities. Because of improved knowledge about worker activities, the results for year 2011 are detailed per activity sectors in each field. Lasting limitations prevent from having complete and reliable worker activity information. Solutions are considered to reduce the inaccuracy in the annually published statistics. The evolution of occupational external exposure to ionising radiation from 2005 to 2011 in France is then presented for the main activity fields. (authors)

  4. Modelling the propagation of effects of chronic exposure to ionising radiation from individuals to populations

    Energy Technology Data Exchange (ETDEWEB)

    Alonzo, F. [Laboratory of Environmental Modelling, DEI/SECRE/LME, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache, Building 159, BP3, 13115 St-Paul-lez-Durance Cedex (France); Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)], E-mail: frederic.alonzo@irsn.fr; Hertel-Aas, T. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Gilek, M. [School of Life Sciences, Soedertoern University College, 14189 Huddinge (Sweden); Gilbin, R. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France); Oughton, D.H. [Department of Plant and Environmental Sciences, P.O. Box 5003, Norwegian University of Life Sciences, 1432 Aas (Norway); Garnier-Laplace, J. [Laboratory of Radioecology and Ecotoxicology, DEI/SECRE/LRE, Institute of Radioprotection and Nuclear Safety (IRSN), Cadarache Building 186, BP3, 13115 St-Paul-lez-Durance Cedex (France)

    2008-09-15

    This study evaluated the potential effect of ionising radiation on population growth using simple population models and parameter values derived from chronic exposure experiments in two invertebrate species with contrasting life-history strategies. In the earthworm Eisenia fetida, models predicted increasing delay in population growth with increasing gamma dose rate (up to 0.6 generation times at 11 mGy h{sup -1}). Population extinction was predicted at 43 mGy h{sup -1}. In the microcrustacean Daphnia magna, models predicted increasing delay in population growth with increasing alpha dose rate (up to 0.8 generation times at 15.0 mGy h{sup -1}), only after two successive generations were exposed. The study examined population effects of changes in different individual endpoints (including survival, number of offspring produced and time to first reproduction). Models showed that the two species did not respond equally to equivalent levels of change, the fast growing daphnids being more susceptible to reduction in fecundity or delay in reproduction than the slow growing earthworms. This suggested that susceptibility of a population to ionising radiation cannot be considered independent of the species' life history.

  5. Fluorescence in situ hybridisation in chromosome aberration detection in subjects occupationally exposed to ionising radiation

    International Nuclear Information System (INIS)

    For more than two decades, chromosomal aberration analysis has been used to detect structural chromosomal aberrations as sensitive biodosimeters of occupational exposure to ionising radiation. Its use is also recommended by the World Health Organisation. Changes in chromosome structure detected by that method are considered to be early biomarkers of a possible malignant disease. Aberrations detected by the method are unstable and can be found in the lymphocytes of irradiated personnel only within a limited time after exposure. To detect stable chromosomal aberrations, which persist after exposure, multicolour fluorescent in situ hybridisation has to be used. Using DNA probes labelled with different fluorochromes, it dyes each pair of chromosomes with different colour. Due to the dynamic of unstable aberration formation, chromosomal aberration analysis is more suitable in genome damage assessment of recent exposures. On the other hand, fluorescence in situ hybridisation gives the information on chromosome instability caused by long-term occupational exposure to ionising radiation. Considering the high costs of fluorescence in situ hybridisation and the uncertainty of the result, it should be used in biodosimetry only when it is absolutely necessary.(author)

  6. First Glossary of Modern Physics and Ionising Radiation Protection in Croatian

    International Nuclear Information System (INIS)

    Motivation and encouragement for the Glossary were given as the research theme for the joint seminar between the Faculty of Electrical Engineering and Computing and Rudjer Boskovic Institute, within a postgraduate course subject ''Detectors and electronic instrumentation for particle physics''. A basic motivation is due to a lack of specialized literature in Croatian language in the field of protection of ionising radiation as well as the incompleteness of Croatian terminology in the same field. That is a general problem all over the World because the most glossaries are usually connected either with nuclear power plants or with an application of ionising radiation in medicine. On the other hand, a necessity for the specialized literature for radiation protection which follows a development of modern particle physics and its detection technique is rapidly growing up. A work and development on the Glossary were faced with serious difficulties, since various translations of foreign words and acronyms have already been used by various authors in Croatian literature. Different interpretations of the same term or concept, from diverse sources, had to be very often reconciled. However, the biggest challenge was finding proper Croatian words for the foreign terms, concepts, properties, and quantities which have not yet been commonly used so far in Croatian papers or/and Croatian legislative acts. According to our knowledge this seems to be the first comprehensive Glossary, describing the field of ionising radiation protection and bringing of 300 related entries (terms and guidelines). That is, certainly, the first characteristic Thesaurus in Croatian which includes background of modern physics and chemistry, particle phenomenology and its measurement, all dedicated to the radiological protection of workers, environment and people of the World. A Glossary brings a wide spectrum of terms of broad area of chemistry, radiation protection, nuclear and particle physics. A

  7. Multidisciplinary approach to assess the sensitivity of dwarf tomato plants to low-LET ionising radiation

    Science.gov (United States)

    De Micco, Veronica; De Pascale, Stefania; Aronne, Giovanna; Paradiso, Roberta; Vitaglione, Paola; Turano, Mimmo; Arena, Carmen

    Ionising radiation, acting alone or in interaction with microgravity and other environmental constraints, may affect plant at molecular, morpho-structural and physiological level. The intensity of the plant’s response depends on the properties of radiation and on the features of the plant itself. Indeed, different species are characterised by different susceptibility to radiation which may change during the life course. The aim of this research was to study the radiosensitivity to low-LET ionising radiation of plants of dwarf tomato (Solanum lycopersicum L. ‘Microtom’) at two phenological phases (vegetative and reproductive), within the purpose of analysing plants for consideration as candidates for Bioregenerative Life Support Systems (BLSS) in Space. To pursue this objective, plants of the cultivar Microtom were irradiated with different doses of X-rays either at the stage of the second true leaf (VP - vegetative phase) or when at least one flower was blossomed (RP - reproductive phase). Plant’s response to ionising radiation was assessed through a multidisciplinary approach combining genetic analyses, ecophysiological measurements, morpho-anatomical characterisation of leaves and fruits, nutritional analyses of fruits. Growth, molecular and morpho-functional traits were measured during plant development up to fruiting in both VP and RP plant groups, and compared with non-irradiated control plants. Plant growth was monitored weekly recording parameters such as plant height, number of leaves, leaf area, flowering and fruiting rate. Potential DNA alterations were explored through Random Amplified Polymorphic DNA (RAPD) technique. The efficiency of the photosynthetic apparatus was evaluated by determining photosynthetic pigment composition, photochemistry and leaf gas exchanges. Leaf and fruit structure were analysed through light and epi-fluorescence microscopy. Leaf anatomical traits related to photosynthetic efficiency, and to structural radioprotection

  8. Guidance notes for the protection of persons against ionising radiations arising from medical and dental use

    International Nuclear Information System (INIS)

    Guidance notes have been prepared by the NRPB, the Health Departments and the Health and Safety Executive for the protection of all persons against ionising radiations arising from medical and dental use. The guidance notes are a guide to good radiation protection practice consistent with regulatory requirements. The areas covered include medical and dental radiology, diagnostic X-ray equipment for medical and dental radiography, beam therapy and remotely controlled after-loading, brachytherapy, diagnostic and therapeutic uses of unsealed radioactive substances, diagnostic uses of sealed or other solid radioactive sources, patients leaving hospital after administration of radioactive substances, precautions after death of a patient whom radioactive substances have been administered, storage and movement of radioactive substances, disposal of radioactive waste and contingency planning and emergency procedures. (U.K.)

  9. Applying the ionising radiation regulations to radon in the UK workplace

    International Nuclear Information System (INIS)

    As a response to the identification of a health risk from workplace radon in the UK, the Ionising Radiations Regulations include the protection of workers from excessive levels of radon. Employers are required to make risk assessments, and the interpretation of the Health and Safety Executive is that the regulations apply to workplace premises in locations already designated as Radon Affected Areas for domestic purposes, with the difference that in workplaces, it is the maximum winter radon concentration rather than the annual average which is the parameter of interest. This paper discusses the rationale behind the current regulatory environment, outlines the role and duties of Accredited Radiation Protection Advisers and summarises the strategies necessary to conform to the regulations. (authors)

  10. In vivo EPR dosimetry to quantify exposures to clinically significant doses of ionising radiation

    International Nuclear Information System (INIS)

    As a result of terrorism, accident or war, populations potentially can be exposed to doses of ionising radiation that could cause direct clinical effects within days or weeks. There is a critical need to determine the magnitude of the exposure to individuals so that those with significant risk can have appropriate procedures initiated immediately, while those without a significant probability of acute effects can be reassured and removed from the need for further consideration in the medical/emergency system. It is extremely unlikely that adequate dosemeters will be worn by the potential victims, and it also will be unlikely that prompt and accurate dose reconstruction at the level of individuals will be possible. Therefore, there is a critical need for a method to measure the dose from radiation-induced effects that occur within the individual. In vivo EPR measurements of radiation-induced changes in the enamel of teeth is a method, perhaps the only such method, which can differentiate among doses sufficiently to classify individuals into categories for treatment with sufficient accuracy to facilitate decisions on medical treatment. In its current state, the in vivo EPR dosemeter can provide estimates of absorbed dose of ± 0.5 Gy in the range from 1 to >10 Gy. The lower limit and the precision are expected to improve, with improvements in the resonator and the algorithm for acquiring and calculating the dose. In its current state of development, the method is already sufficient for decision-making action for individuals with regard to acute effects from exposure to ionising radiation for most applications related to terrorism, accidents or nuclear warfare. (authors)

  11. EPR spectroscopy for the detection of foods treated with ionising radiation

    International Nuclear Information System (INIS)

    The advantage of electron paramagnetic resonance spectroscopy (EPR or ESR) as a tool for the control of irradiated food lies in its sensitivity and accuracy. Ionising radiation produces, in irradiated materials, paramagnetic species of different kinds, i.e. radicals, radical-ions and paramagnetic centres, which can be measured by EPR but most of them are not stable enough to be used for the detection of irradiation. It is because radiation-induced paramagnetic species are thermodynamically less stable than surrounding molecules and take part in fast radiolytic reactions leading to the formation of final diamagnetic products that they are not detectable by the EPR method. Most of organic radicals produced by radiation in the liquid phase ae unstable but if the unpaired electron is incorporated into the complex polymeric system as in peptides and polysaccharides and is structurally isolated from the water, its stability is markedly increased. Since 1954 it is known that ionising radiation produces paramagnetic entities in biological materials, cells and tissues and some are stable enough to be observed by EPR spectroscopy at room temperature. The present paper describes and discusses that part of results obtained by this group during the period of ADMIT activity (1989-94) which are original and may be useful to those who will be working in the near future on the development of uniform control systems for the detection of irradiated food. The intention was to focus attention on these facts and data which influence the certainty of the detection in both positive and negative manner. (author)

  12. Genotoxicity in earthworm after combined treatment of ionising radiation and mercury

    International Nuclear Information System (INIS)

    This study was performed to investigate the acute genotoxic effects of mercury and radiation on earthworms (Eisenia fetida). The levels of DNA damage and the repair kinetics in the coelomocytes of E. fetida treated with mercuric chloride (HgCl2) and ionising radiation (gamma rays) were analysed by means of the comet assay. For detection of DNA damage and repair, E. fetida was exposed to HgCl2 (0-160 mg kg-1) and irradiated with gamma rays (0-50 Gy) in vivo. The increase in DNA damage depended on the concentration of mercury or dose of radiation. The results showed that the more the oxidative stress induced by mercury and radiation the longer the repair time that was required. When a combination of HgCl2 and gamma rays was applied, the cell damage was much higher than those treated with HgCl2 or radiation alone, which indicated that the genotoxic effects were increased after the combined treatment of mercury and radiation. (authors)

  13. DNA radiation damage and asymmetric somatic hybridization: Is UV a potential substitute or supplement to ionising radiation in fusion experiments?

    International Nuclear Information System (INIS)

    Recent reports have revealed that the asymmetric nature of the nuclear genome of somatic hybrids, produced following the irradiation of one of the parents with X- or gamma rays, is generally much less than had been anticipated. As a consequence, we have begun to investigate whether UV radiation might be used as an alternative or indeed a supplement to the presently-used ionising radiation techniques in such experiments. Cell culture studies have revealed that UV radiation induces the desired physiological effects in sugar beet (Beta vulgaris) protoplasts, namely, a prevention of cell division without immediate cytotoxicity. Preliminary studies using denaturing and pulsed field gel electrophoresis have shown that UV can also induce substantial physical fragmentation of DNA. When using the same techniques, less breakdown was observed following gamma radiation. All results were highly reproducible. Such results augur well for the potential use of UV in asymmetric somatic cell fusion experiments. (author)

  14. Non-targeted effects of ionising radiation (note). A new European integrated project, 2006-2010

    International Nuclear Information System (INIS)

    Complete text of publication follows. The general objectives of the NOTE project are: (1) to investigate the mechanisms of nontargeted effects, in particular, bystander effects, genomic instability and adaptive response; (2) to investigate if and how non-targeted effects modulate the cancer risk in the low dose region, and whether they relate to protective or harmful functions; (3) to investigate if ionising radiation can cause non-cancer diseases or beneficial effects at low and intermediate doses; (4) to investigate individual susceptibility and other factors modifying non-targeted responses; (5) to assess the relevance of non-targeted effects for radiation protection and to set the scientific basis for a modern, more realistic, radiation safety system; (6) to contribute to the conceptualisation of a new paradigm in radiation biology that would cover both the classical direct (DNA-targeted) and non-targeted (indirect) effects. The NOTE brings together 19 major European and Canadian groups involved in the discovery, characterisation and mechanistic investigation of non-targeted effects of ionising radiation in cellular, tissue and animal models. The NOTE research activities are organised in six work packages. Four work packages (WPs 2-5) are problem-oriented, focussing on major questions relevant for the scientific basis of the system of radiation protection: WP2 Mechanisms of non-targeted effects, WP3 Non-cancer diseases, WP4 Factors modifying non-targeted responses, WP5 Modelling of non-targeted effects. The integration activities provided by WP6 strengthen the collaboration by supporting the access to infrastructures, mobility and training. WP7 provides dissemination and exploitation activities in the form of workshops and a public website. Managerial activities (WP1) ensure the organisation and structures for decision making, monitoring of progress, knowledge management and efficient flow of information and financing. Coordinator of the NOTE project is Prof

  15. Positive effects of small doses of ionising radiation on plants and animals

    International Nuclear Information System (INIS)

    Although part of the favourable results is likely to be due to wrong methods there is still a big part which must be taken seriously. Positive effects occurred after irradiation with X-, β, and γ rays and fast electrons. In plants, positive effects occurred after acute irradiation of the seed in the range of 1 R-10000 R, after acute irradiation of the growing plants with 50 R-1000, and after chronic irradiation of growing plants in the range of 0.02 R/day-230 R/day. For insects, the radiation doses with stimulating effects were, for acute irradiation, between 50 R and 180.00O R, for chronic irradiation between 9.5 R/day-75.9 R/hour. For mammals, positive effects of acute irradiation were found in the range of 40 R-400 R, after chronic irradiation of 0.11 R/day-5 R/day. The lower limits of these dose ranges are mainly due to the fact that smaller doses have not been dealt with at all. Positive effects of ionising radiation were seen especially when the experimental animals or plants were kept under unfavourable conditions. The exact mechanism of the radiation stimulation has not been explained yet. The assumption is favoured that the radiation causes a stimulation of repair mechanisms, - similar to the enzyme induction, may be - which enables the organisms to face further damage better due to their improved repair capacity. The generation of heterocygotes or of polyploidy by radiation seems also a plausible explanation of the positive radiation effects. In some experiments which revealed an increased radiation resistance after pre-radiation the synchronisation of the cell cycle caused by a radiation-induced delay of unitosis is likely to play a role. (orig./MG)

  16. Draft guidance notes for the protection of persons exposed to ionising radiations in research and teaching

    International Nuclear Information System (INIS)

    These guidance notes have been prepared for those who use ionising radiation in a wide range of research work and teaching, such as that under the control of universities, polytechnics, Government Departments or research organisations and for those who work in industrial research laboratories. Ancillary activities, such as the testing and calibration of equipment and the storage and disposal of radioactive materials, are also covered by these notes so far as they are carried out on the same premises. The guidance notes indicate procedures for the protection of all persons who may be exposed as a result of these practices, i.e. all employed persons, apprentices and students, and members of the public. (author)

  17. Guidance on approval of dosimetry services under the ionising radiations regulations 1985

    International Nuclear Information System (INIS)

    Regulation 15 of the Ionising Radiations Regulations 1985 gives the Health and Safety Executive the power to approve suitable dosimetry services for the purpose of Regulations 13 (dose assessment), 14 (accident dosimetry) and 27 (contingency plans). Part 3 of notes for guidance for dosimetry services wishing to apply to the HSE for approval is presented. This describes those aspects which are relevant to co-ordination of inputs from contributing approved dosimetry services (ADS's) and record keeping of assessed doses. It sets out the functions of the co-ordinating ADS's, gives guidance on interpretation of dose quantities, specifies the minimum content of dose records and describes suitable types of dose record storage. Finally the basis on which HSE will assess a service for approval is outlined. (U.K.)

  18. Connecting the dots: a correlation between ionising radiation and cloud mass-loss rate traced by optical integral field spectroscopy

    CERN Document Server

    McLeod, A F; Dale, J E; Ginsburg, A; Klaassen, P D; Mottram, J C; Preibisch, T; Ramsay, S; Reiter, M; Testi, L

    2016-01-01

    We present an analysis of the effect of feedback from O- and B-type stars with data from the integral field spectrograph MUSE mounted on the Very Large Telescope of pillar-like structures in the Carina Nebular Complex, one of the most massive star-forming regions in the Galaxy. For the observed pillars, we compute gas electron densities and temperatures maps, produce integrated line and velocity maps of the ionised gas, study the ionisation fronts at the pillar tips, analyse the properties of the single regions, and detect two ionised jets originating from two distinct pillar tips. For each pillar tip we determine the incident ionising photon flux $Q_\\mathrm{0,pil}$ originating from the nearby massive O- and B-type stars and compute the mass-loss rate $\\dot{M}$ of the pillar tips due to photo-evaporation caused by the incident ionising radiation. We combine the results of the Carina data set with archival MUSE data of a pillar in NGC 3603 and with previously published MUSE data of the Pillars of Creation in M...

  19. Law on protection against ionising radiation and nuclear safety in Slovenia

    International Nuclear Information System (INIS)

    The existing legislation related to nuclear and radiation safety in Slovenia was introduced in 80's. The necessity for the new law is based on the new radiation safety standards (ICRP 60) and the intention of Slovenia to harmonize the legislation with the European Union. The harmonization means adoption of the basic safety standards and other relevant directives and regulations of Euratom. The nuclear safety section of this law is based on the legally binding international conventions ratified by Slovenia. The general approach is similar to that of some members of Nuclear Energy Agency (OECD). The guidelines of the law were set by the Ministry of the Environment and Spatial Planning, Nuclear Safety Administration, and Ministry of Health. The expert group of the Ministry of Environment and Spatial Planning and the Ministry of Health together with the representatives of the users of the ionising sources and representatives of the nuclear sector, prepared the draft of the subject law. The emphasis in this paper is given to main topics and solutions related to the control of the occupationally exposed workers, radiation safety, licensing, nuclear and waste safety, and radiation protection of people and patients. (authors)

  20. Effect of ionizing radiation on cardiovascular system; Les effets des rayonnements ionisants sur le systeme cardiovasculaire

    Energy Technology Data Exchange (ETDEWEB)

    Milliat, F.; Benderitter, M.; Gaugler, M.H. [Institut de radioprotection et de surete nucleaire, DRPH, SRBE, Laboratoire de radiopathologie et de therapies experimentales (LRTE), Fontenay-aux-Roses (France)

    2011-07-01

    Radiotherapy treatment for cancer of the chest, mediastinal area or the neck area is associated with increased risk of cardiovascular disease. With the increasing number of cancer patients and the increased treatment efficiency, the number of cancer survivors is increasing exponentially. The cancer survivors live longer and their long-term follow-up must be considered. The cardiovascular toxicity is mainly associated with the treatment of breast cancer, Hodgkin's lymphoma and head and neck cancer. Radiation-induced cardiovascular effects are insidious and chronic. Their occurrence is linked to numerous factors including the age of the patient at the beginning of the radiotherapy schedule, the number of years following radiotherapy, the doses (and volume) to the heart and the large vessels (coronary and carotid arteries), and the association with the traditional cardiovascular risk factors. Pathophysiological mechanisms remain unclear and, even if similarities with age-related atherosclerosis were established, the specificities of the radiation-induced atherosclerosis for high doses remain to be discovered. For low/moderate doses of ionising radiation, recent epidemiological studies provide evidence of increased risk of cardiovascular pathologies. A better knowledge of the mechanisms associated with the radiation-induced cardiovascular pathologies and the more precise identification of the populations at risk in the future should allow a more effective care of these patients with cardiovascular risk. (authors)

  1. Nuclear and cytoplasmic signalling in the cellular response to ionising radiation

    International Nuclear Information System (INIS)

    DNA is the universal primary target for ionising radiation; however, the cellular response is highly diversified not only by differential DNA repair ability. The monitoring system for the ionising radiation-inflicted DNA damage consists of 3 apparently independently acting enzymes which are activated by DNA breaks: two protein kinases, ATM (ataxia telangiectasia mutated) and DNA-PK (DNA-dependent protein kinase) and a poly(ADP-ribose) polymerase, PARP-1. These 3 enzymes are the source of alarm signals, which affect to various extents DNA repair, progression through the cell cycle and eventually the pathway to cell death. Their functions probably are partly overlapping. On the side of DNA repair their role consists in recruiting and/or activating the repair enzymes, as well as preventing illegitimate recombination of the damaged sites. A large part of the nuclear signalling pathway, including the integrating role of TP53 has been revealed. Two main signalling pathways start at the plasma membrane: the MAPK/ERK (mitogen and extracellular signal regulated protein kinase family) 'survival pathway' and the SAPK/JNK (stress-activated protein kinase/c-Jun N-terminal kinase) 'cell death pathway'. The balance between them is likely to determine the cell's fate. An additional important 'survival pathway' starts at the insulin-like growth factor type I receptor (IGF-IR), involves phosphoinositide- 3 kinase and Akt kinase and is targeted at inactivation of the pro-apoptotic BAD protein. Interestingly, over-expression of IGF-IR almost entirely abrogates the extreme radiation sensitivity of ataxia telangiectasia cells. When DNA break rejoining is impaired, the cell is unconditionally radiation sensitive. The fate of a repair-competent cell is determined by the time factor: the cell cycle arrest should be long enough to ensure the completion of repair. Incomplete repair or misrepair may be tolerated, when generation of the death signal is prevented. So, the character and timing

  2. The effect of additives on the enhancement of methyl methacrylate grafting to cellulose in the presence of UV and ionising radiation

    International Nuclear Information System (INIS)

    The role of various additives in the grafting of methyl methylacrylate (MMA) to cellulose using UV and ionising radiation has been investigated. MMA grafting yields are hampered by competing homopolymerisation. The styrene comonomer technique was utilised to overcome this problem. The role of acid in these reactions has been studied as well as additives like, an inclusion compound (urea), thermal initiators and photoinitiators. Methanol was used as the swelling agent in all the experiments. Molecular weight studies with homopolymers indicate that both chemical and physical processes are involved in the mechanism of the reaction. The physical process involves a partitioning phenomenon whereas the chemical process concerns additional radical reactions in the radiation initiation step. This grafting mechanism is shown to be applicable to the simple radiation polymerisation of monomers in solution and also analogous UV fast curing systems. (author)

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

    International Nuclear Information System (INIS)

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

  4. Gene expression analysis after low dose ionising radiation exposure of the developing organism

    International Nuclear Information System (INIS)

    Measuring gene expression using microarrays is relevant to many areas of biology and medicine, such as follow up of developmental stages and diseases onset, and treatment study. Since there can be tens of thousands of distinct probes on an array, each micro array experiment can accomplish the equivalent number of genetic tests in parallel. Arrays have therefore dramatically accelerated many types of investigations. For example, microarrays can be used to identify stress response genes by comparing gene expression in challenged versus normal cells. In the Molecular and Cellular Biology lab (MCB), the micro array experiments are performed within the Genomic Platform, fully equipped to analyse either the behaviour of bacteria during long space flight, the effect of low dose ionising radiation on the developing organism in mice, or the human individual radiation sensitivity. For the low dose effect, two main stages of development are of interest; 1) the gastrula stage at which ionizing radiation can induce several malformations. 2) the organogenesis. During brain development, epidemiological studies of the atomic bomb survivors of Hiroshima/Nagasaki showed increased risk of mental retardation in children of women exposed between weeks 8-15 of pregnancy or at a lower extend between weeks 15 to 25

  5. The Combined Effect of Anesthetic Sevoflurane and Ionising Radiation on Primary DNA Damage in Mice

    International Nuclear Information System (INIS)

    In induction and maintenance of general anesthesia, an inhalation anaesthetic sevoflurane (hexafluoroisopropyl fluoromethyl ether) is widely used mostly due to its low solubility and non-irritability. The aim of the study was to examine the degree of sensitivity of different types of tissue (brain, liver and kidneys) and peripheral blood leukocytes after interaction of γ-radiation (60Co) in a clinically relevant dose (1 Gy) with anesthetic sevoflurane (2.4 %, 50:50) in the model of Swiss albino mice. For primary DNA damage assessment, the method of alkaline comet assay was applied immediately after and 2, 6 and 24 h after exposure to radiation and anaesthesia. The strongest genotoxic effect was measured in kidney and brain cells 2 hours, in the blood 6 hours, and in the liver 24 hours after the treatment of the animals as compared to a control group. To test the difference in the amount of repair between blood and various tissues, cellular DNA repair index (CRI) was calculated, which showed different sensitivity of organs. The results showed synergistic effect of combined interaction between anaesthetic and ionising radiation, pointing out the necessity for extreme precaution in choosing and dealing with anaestetics during radiotherapy procedures.(author)

  6. Interactions between carbo-platin, cisplatin and ionising radiation in an human ovarian cancer cell line

    International Nuclear Information System (INIS)

    Cisplatin (CDDP) and radiotherapy are frequently used concomitantly in the treatment of various malignant conditions. Because of its toxicity, cisplatin tends to be replaced by carbo-platin (CBDCA) in several indications. Available data regarding the combined effects of cisplatin and carbo-platin with ionising radiation are contradictory. Various concentrations of cisplatin and carbo-platin and various timing of association with radiation have been tested in vitro in a human ovarian cancer cell line. The parental cell line (AOvC-0) and a cisplatin-resistant stable sub-line (AOvC-CDDP/O) (De Pooter et al., Cn Res, 1991) were exposed to carbo-platin (2.5, 5 and 10 M) and to CDDP (1, 2.5 and 5 M), 16 h and 4 h before and 4 h and 16 h after irradiation, respectively. Cell survival was evaluated by a classical clonogenic assay. Exposure of AOvC-0 to 5M CBDCA and of AOvC-CDDDP/O to 10 M CBDCA, before or shortly after radiation exposure, increased cell lethality in a clear supra-additive way, with the highest DEF in the shoulder region of the survival curve and at radiation doses relevant to clinical radiotherapy. In the sensitive cell line, 5 M carbo-platin resulted in an additional lethality equivalent to 4.5 Gy; in the resistant cells, 10M carbo-platin was equivalent to 3.6 Gy. Replacing carbo-platin by cisplatin in an identical set-up demonstrated exclusively simple additivity (DEF = 1). These data suggest that carbo-platin and cisplatin delivered at equi-toxic doses interact with radiation a different way and that, in the present set-up, only carbo-platin enhanced the effects of radiation. Carbo-platin might consequently be a better candidate than cisplatin in some concomitant combinations with radiotherapy. (authors)

  7. Cellular responses in primary epidermal cultures from oncorhynchus mykiss following the combined exposure of ionising radiation and a heavy metal

    International Nuclear Information System (INIS)

    Mechanisms of toxicant action on biological systems are difficult to identify when more than one contaminant is involved due to potential synergistic and antagonistic effects. There is a general paucity of research into the effect of radiation exposure in tandem with common environmental contaminants due to the inherent difficulties involved. In vitro cell cultures are particularly suited to the study of toxic mechanisms due to their proximity to toxic modes of action and the absence of the multiple defence mechanisms present in intact organisms. Primary cell cultures are particularly beneficial in this area of research as they still maintain many of their tissue specific functions. The objective of this study was to distinguish different mechanisms of cell death (growth arrest, apoptosis, primary and secondary necrosis and proliferation), following combination exposure to ionising radiation and a heavy metal (ZnCl2). The model system employed was a primary cell culture of rainbow trout (Oncorhynchus mykiss) epidermal tissue which has been previously used to study the effects of various environmental agents in this laboratory. Apoptosis and necrosis were quantified morphologically while proliferation was assessed immuno-cyto-chemically using an anti PCNA (proliferating cell nuclear antigen) antibody. While radiation doses up to and including 10 Gy had no effect on growth, exposure to ZnCl2 produced a significant dose dependent reduction in growth (10, 50, 75, 100 and 200 ppm ZnCl2). Preliminary results indicate no significant effect on growth following a combined exposure of 5 Gy + 50 ppm ZnCl2. These results may have important implications for understanding the mechanisms underlying cellular responses to multiple contaminant exposures. (author)

  8. The Design of Diagnostic Medical Facilities where Ionising Radiation is used

    International Nuclear Information System (INIS)

    The original Code of Practice on The Design of Diagnostic Medical Facilities Using Ionising Radiation was first published by the Nuclear Energy Board in 1988. In the intervening years the 'Blue Book' as it became known has served the medical community well as the sector has expanded and modernised and the late Dr Noel Nowlan, then Chief Executive of the Nuclear Energy Board, deserves much credit for initiating this pioneering contribution to radiation safety in Ireland. There have been significant developments since its publication in terms of the underlying radiation protection legislation, regulatory practice as well as developments in new technologies that have given rise to the need for a revision of the Code. This revised Code is based on a comprehensive draft document produced by the Haughton Institute under contract to the RPII and was finalised following extensive consultations with the relevant stakeholders. The revised Code includes a brief review of the current legislative framework and its specific impact on the management of building projects (Chapters 1 and 2), a presentation of the main types of radiological (Chapter 3) and nuclear medicine (Chapter 4) facilities, a treatment of the technical aspects of shielding calculations (Chapter 5) and a discussion of the practical aspects of implementing shielding solutions in a building context (Chapter 6). The primary purpose of the Code is to assist in the design of diagnostic facilities to the highest radiation protection standards in order to ensure the safety of workers and members of the public and the delivery of a safe service to patients. Diagnostic radiology is a dynamic environment and the Code is intended to be used in consultation with the current literature, an experienced Radiation Protection Advisor and a multidisciplinary project team

  9. Risk of cancer from occupational exposure to ionising radiation: retrospective cohort study of workers in France, the United Kingdom, and the United States (INWORKS)

    OpenAIRE

    Richardson, David B.; Cardis, Elisabeth; Daniels, Robert D; Gillies, Michael; O’Hagan, Jacqueline A; Hamra, Ghassan B.; Haylock, Richard; Laurier, Dominique; Leuraud, Klervi; MOISSONNIER, Monika; Schubauer-Berigan, Mary K.; Thierry-Chef, Isabelle; Kesminiene, Ausrele

    2015-01-01

    Study question Is protracted exposure to low doses of ionising radiation associated with an increased risk of solid cancer? Methods In this cohort study, 308 297 workers in the nuclear industry from France, the United Kingdom, and the United States with detailed monitoring data for external exposure to ionising radiation were linked to death registries. Excess relative rate per Gy of radiation dose for mortality from cancer was estimated. Follow-up encompassed 8.2 million person years. Of 66 ...

  10. Simulation and measurements of the response of an air ionisation chamber exposed to a mixed high-energy radiation field

    International Nuclear Information System (INIS)

    CERN's radiation protection group operates a network of simple and robust ionisation chambers that are installed inside CERN's accelerator tunnels. These ionisation chambers are used for the remote reading of ambient dose rate equivalents inside the machines during beam-off periods. This Radiation Protection Monitor for dose rates due to Induced Radioactivity ('PMI', trade name: PTW, Type 34031) is a non-confined air ionisation plastic chamber which is operated under atmospheric pressure. Besides its current field of operation it is planned to extend the use of this detector in the Large Hadron Collider to measure radiation under beam operation conditions to obtain an indication of the machine performance. Until now, studies of the PMI detector have been limited to the response to photons. In order to evaluate its response to other radiation components, this chamber type was tested at CERF, the high-energy reference field facility at CERN. Six PMI detectors were installed around a copper target being irradiated by a mixed hadron beam with a momentum of 120 GeV c-1. Each of the chosen detector positions was defined by a different radiation field, varying in type and energy of the incident particles. For all positions, detailed measurements and FLUKA simulations of the detector response were performed. This paper presents the promising comparison between the measurements and simulations and analyses the influence of the different particle types on the resulting detector response. (authors)

  11. The use of caffeine to assess high dose exposures to ionising radiation by dicentric analysis

    International Nuclear Information System (INIS)

    Dicentric analysis is considered as a 'gold standard' method for biological dosimetry. However, due to the radiation-induced mitotic delay or inability to reach mitosis of heavily damaged cells, the analysis of dicentrics is restricted to doses up to 4-5 Gy. For higher doses, the analysis by premature chromosome condensation technique has been proposed. Here, it is presented a preliminary study is presented in which an alternative method to analyse dicentrics after high dose exposures to ionising radiation (IR) is evaluated. The method is based on the effect of caffeine in preventing the G2/M checkpoint allowing damaged cells to reach mitosis. The results obtained indicate that the co-treatment with Colcemide and caffeine increases significantly increases the mitotic index, and hence allows a more feasible analysis of dicentrics. Moreover in the dose range analysed, from 0 to 15 Gy, the dicentric cell distribution followed the Poisson distribution, and a simulated partial-body exposure has been clearly detected. Overall, the results presented here suggest that caffeine has a great potential to be used for dose-assessment after high dose exposure to IR. (authors)

  12. The escape of ionising radiation from high-redshift dwarf galaxies

    CERN Document Server

    Paardekooper, Jan-Pieter; Altay, Gabriel; Kruip, Chael

    2011-01-01

    The UV escape fraction from high-redshift galaxies plays a key role in models of cosmic reionisation. Because it is currently not possible to deduce the escape fractions during the epoch of reionisation from observations, we have to rely on numerical simulations. Our aim is to better constrain the escape fraction from high-redshift dwarf galaxies, as these are the most likely sources responsible for reionising the Universe. We employ a N-body/SPH method that includes realistic prescriptions for the physical processes that are important for the evolution of dwarf galaxies. These models are post-processed with radiative transfer to determine the escape fraction of ionising radiation. We perform a parameter study to assess the influence of the spin parameter, gas fraction and formation redshift of the galaxy and study the importance of numerical parameters as resolution, source distribution and local gas clearing. We find that the UV escape fraction from high-redshift dwarf galaxies that have formed a rotational...

  13. Effect of penetrating ionising radiation on the mechanical properties of pericardium

    Energy Technology Data Exchange (ETDEWEB)

    Daar, Eman, E-mail: e.daar@surrey.ac.u [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Woods, E. [Royal Free Hampstead NHS Trust, Pond Street, Hampstead, London NW3 2QG (United Kingdom); Keddie, J.L. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Nisbet, A. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Royal Surrey County Hospital, Guildford (United Kingdom); Bradley, D.A. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2010-07-21

    The pericardium is an anistropic composite material made up of collagen and elastin fibres embedded in an amorphous matrix mainly composed of proteoglycan and hyaluronan. The collagen fibres are arranged in layers, with different directions of alignment in each layer, giving rise to interesting mechanical properties of pericardium, including the ability to undergo large deformation during performance of regular physiological functions. The present study aims to investigate the effect of penetrating photon ionising radiation on bovine pericardium tissue, being part of a study of the effect of cardiac doses received in breast radiotherapy and the possibility that this can give rise to cardiovascular complications. Irradiation doses in the range 5-80 Gy were used. To characterise the various mechanical properties [elastic modulus, stress relaxation, ultimate tensile strength (UTS) and fracture] a uniaxial tensile test method was applied. The preliminary results reflect the wide inter-sample variations that are expected in dealing with tissues, with only a weak indication of increase in the UTS of the pericardium tissue with increase in radiation dose. Such an effect has also been observed by others, with reduction in UTS at doses of 80 Gy.

  14. A comparison of statistical methods for estimation of less than detectable ionising radiation exposures

    International Nuclear Information System (INIS)

    Methods were developed to estimate the ionising radiation dose below the detection level (DL) of personal monitoring devices for a case-control study of protracted radiation exposure and lung cancer. Exposure data were grouped by dosemeter type and monitoring period. Each group contained dosimetry data that were interval-censored from limitations in measurement precision and included left-censoring of observations below detection. The grouped data were fit to a three parameter hybrid-lognormal distribution by maximum likelihood estimation. Using the fitted distribution, bootstrap samples were either simulated by Monte Carlo or constructed by sampling with replacement. The resulting bootstrap sample distributions were then used to predict the missing dose values and the associated uncertainty in the estimate. Among study subjects, 1357 workers were monitored with film dosimetry. Among the 39,263 dose observations 20,416 were recorded as zero dose, indicating 52% left-censoring. The statistical methods estimated 0.31 person-Sv below the DL or ∼1% of the total collective dose for this study population. (authors)

  15. Framework for the Protection of the Environment from Ionising Radiation (invited paper)

    International Nuclear Information System (INIS)

    A framework is proposed for the protection of the environment from ionising radiation. Key components include the assessment of the environmental transfer of radionuclides and uptake of radionuclides by organisms, the adaptation of existing dosimetric models to calculate absorbed doses and studies concerning dose-effects relationships for selected organisms. The proposed framework will also make use of 'reference' organisms, selection of which will be based on a number of criteria, e.g. radiosensitivity, ubiquity, and will involve the development of standardised biota exposure units which might integrate the Relative Biological Effect (RBE) of the radiation under consideration. In the second part of the study, initial efforts have been made to develop a computerised system in order to provide a simple example of how components of this framework may be formulated. An equilibrium absorbed dose constant model has been used for high LET (Linear Energy Transfer) radionuclides combined with the application of an absorbed fraction for γ-emitting radionuclides. Generalised specific activity information for selected radionuclides from Norwegian marine environments have been used as model input data. For the radionuclides considered, total doses for marine organisms (lobster, mussels, seaweed) ranged between 1.35-2.5 mGy.y-1, mainly attributable to 40K and 210Po. Such levels are well below those where observable effects might be expected. (author)

  16. Surveillance of health care workers exposed to ionising radiation: Rimed pilot study

    International Nuclear Information System (INIS)

    The project so-called RIMED aimed to set up epidemiological surveillance of health care workers exposed to ionizing radiation. A pilot study was conducted in a sample of hospital personnel to examine the possibility of identifying exposed subjects in order to analyse mortality patterns according to occupational characteristics such as medical departments or occupations in a historical cohort. Seven hospitals participated in this pilot study. Health-care workers who had worn a dosimeter up to December 2003 were to be included in this cohort. The subjects' identification data were obtained from the SISERI (Systeme d'information de la surveillance de l'exposition aux rayonnements ionisants - Ionizing Radiation Exposure Monitoring Information System) database managed by the Institut de radioprotection et de surete nucleaire - Radiation Protection and Nuclear Safety Institute (IRSN). The SISERI system was in a 'pilot' phase in 2004. According to SISERI database, a total of 5126 subjects were found to have worn a dosimeter up to December 2003. The subjects' identification data were completed by the administrative services of the hospitals and occupational physicians searched for subjects' occupational data. Information required for the vital status search was satisfactorily completed only for 38% of the cohort subjects. This pilot study showed that obtaining data from SISERI database completed by hospital administrative data in 2004 led to a database of insufficient quality for epidemiological surveillance. The Institut de veille sanitaire (French Institute of Public Health Surveillance) recommends that transmission by the employers of some specific personal or occupational data of the exposed subjects should be made compulsory. In this way, SISERI system should be able to constitute any database with required quality for epidemiological surveillance of ionizing radiation exposed subjects. (authors)

  17. Molecular mechanisms of plant response to ionising radiation. Exploration of the glucosinolate role in the anti-oxidative response

    International Nuclear Information System (INIS)

    Terrestrial organisms are exposed to low doses of ionising radiation from natural or anthropogenic sources. The major effects of the radiations are due to DNA deterioration and water radiolysis which generates an oxidative stress by free radical production. Plants constitute good models to study the effects of ionising radiations and the search of antioxidant molecules because of their important secondary metabolism. Thus this thesis, funded by the Brittany region, characterized the physiological and molecular response of the model plant Arabidopsis thaliana to low (10 Gy) and moderate (40 Gy) doses of ionising radiation, and was therefore interested in glucosinolates, characteristic compounds of the Brassicaceae family. The global proteomic and transcriptomic studies carried out on this model revealed (1) a common response for both doses dealing with the activation of DNA repair mechanisms, cell cycle regulation and protection of cellular structures; (2) an adjustment of the energetic metabolism and an activation of secondary compounds biosynthesis (i.e. glucosinolates and flavonoids) after the 10 Gy dose; (3) an induction of enzymatic control of ROS, the regulation of cellular components recycling and of programmed cell death after the 40 Gy dose. The potential anti-oxidative role of glucosinolates was then explored. The in vitro anti-oxidative power of some glucosinolates and their derivative products were demonstrated. Their modulating effects against irradiation-induced damages were then tested in vivo by simple experimental approaches. The importance of the glucosinolate level to give a positive or negative effect was demonstrated. (author)

  18. Cyclic nucleotide Response Element Binding protein (CREB) activation promotes survival signal in human K562 erythroleukemia cells exposed to ionising radiation/etoposide combined treatment

    International Nuclear Information System (INIS)

    Anticancer therapy addresses the destruction of tumour cells which try to counteract the effect of drugs and/or ionising radiation. Thus the knowledge of the threshold over which the cells do not resist such agents could help in the setting up of therapy protocols. Since a key role was assigned to Cyclic nucleotide Response Element Binding protein (CREB) multigenic family (which is composed of several nuclear transcription factors involved in c-AMP signalling in cell differentiation, proliferation, apoptosis, survival and adaptive response and in hematopoiesis and acute leukemias), attention was paid to the activation of Erk cascade and of the downstream kinases and transcription factors such as p90 RSK and CREB. K562 erythroleukemia cell survival to 1.5 Gy ionising radiation with or without etoposide treatment seemed to involve Erk phosphorylation which, regulating p90 RSK, should activate CREB. In parallel, p38 MAP kinase activity down-modulation, along with low caspase-3 activity, and no modification of Bax and Bcl2 levels, supported such evidence. Thus, endogenous CREB activation, triggering a potent survival signal in K562 cells exposed to 1.5 Gy with or without etoposide, led us to suggest that using specific inhibitors against CREB, such as modified phosphorothionate oligodeoxynucleotides (ODN) corresponding to CREB-1 sequence, anticancer therapy efficacy could be improved. (author)

  19. The Follow-Up of Persons Occupationally Overexposed to Ionising Radiations

    International Nuclear Information System (INIS)

    The number of occasions on which workers are overexposed to ionising radiations is very small even when the definition of an overexposure is taken as being any amount in excess of an ICRP permissible level. There is a need for the fullest information about the prognostic significance of overexposures to be. obtained. While it is true that much larger radiation doses are incurred in therapy, or even in some X-ray diagnostic procedures, there are other factors, such as underlying diseases, which can complicate the interpretation of biological consequences in these cases. Therefore, a simple system of registration for all overexposures to workers should be introduced. Such a system should cover only the relatively small number of cases either of external radiation or of internal contamination in which the dose can be considered likely to be in any way significant in respect of ultimate prognosis. Any necessary administrative effort should be made available by a critical review of the effort devoted to the routine recording of very low doses. This paper outlines an example of a registration system which has been instituted in the United Kingdom and outlines the reasoning behind the limited amount of recording which is considered to be useful. In addition to statistical studies of overexposures, there is a need to apply sound occupational health principles to the supervision and future employment of workers involved in such incidents. These should reflect an individual assessment of all aspects of such cases and rule of thumb numerical rules should not apply. Relevant factors in these individual assessments are discussed. (author)

  20. Protection of the environment from ionising radiation. The development and application of a system of radiation protection for the environment. Proceedings of the third international symposium on the protection of the environment from ionising radiation (SPEIR 3). Unedited papers

    International Nuclear Information System (INIS)

    In recent years, awareness of the vulnerability of the environment has increased, as evidenced by new and developing international policies for environmental protection, starting with the Rio Declaration of 1992. In the context of ionizing radiation, the existing international approach is largely based on providing for the protection of humans, but this is being critically reviewed in several international fora. It is in this context that the Third International Symposium on Protection of the Environment from Ionising Radiation (SPEIR 3) was held between 22 and 26 July 2002, in Darwin, Australia. The symposium focused on issues related to the development and application of a system of radiation protection for the environment. The symposium programme included sessions dedicated to: ongoing research on the effects, responses and mechanisms of the interactions of ionizing radiation with biota; policy and ethical dimensions of the development of a framework for environmental radiation protection; and the development and use of methods and models for evaluating radiation as a stressor to the environment. Three workshops were held to allow for detailed discussion of each of these subjects. This symposium was the third in a series. The first International Symposium on Ionising Radiation: Protection of the Natural Environment, was held in Stockholm, Sweden, 20-24 May 1996. This symposium was organized jointly by the Swedish Radiation Protection Institute (SSI) and the Atomic Energy Control Board (AECB) of Canada, and the proceedings were published by the Akademitryck AB, Edsbruk, Sweden in 1996. The second International Symposium on Ionizing Radiation: Environmental Protection Approaches for Nuclear Facilities, was held in Ottawa, Canada, 10-14 May 1999, and was organized by the Canadian Nuclear Safety Commission (CNSC), the Supervising Scientists Group of Environment Australia, and the Swedish Radiation Protection Institute (SSI). The proceedings were published in April

  1. A value-critical assessment of the policy construction of hazard and risk for the safe use of ionising radiation

    International Nuclear Information System (INIS)

    This paper presents a critique of the concept of ionising radiation safety policy from value perspectives that differ from those of the rationalist scientific. It attempts to present a social interpretation of the constitution of the present methods of policy composition that are primarily based on a conservative, orthodox, scientific paradigm. A modification of this process is then offered to integrate social discourse into the policy construction without compromising the value of the scientific input. 6 refs

  2. Xpg limits the expansion of haematopoietic stem and progenitor cells after ionising radiation.

    Science.gov (United States)

    Avila, Alush I; Illing, Anett; Becker, Friedrich; Maerz, Lars D; Morita, Yohei; Philipp, Melanie; Burkhalter, Martin D

    2016-07-27

    Reduced capacity of genome maintenance represents a problem for any organism, potentially causing premature death, carcinogenesis, or accelerated ageing. Strikingly though, loss of certain genome stability factors can be beneficial, especially for the maintenance of tissue stem cells of the intestine and the haematopoietic system. We therefore screened for genome stability factors negatively impacting maintenance of haematopoietic stem cells (HSC) in the context of ionising radiation (IR). We found that in vivo knock down of Xeroderma pigmentosum, complementation group G (Xpg) causes elevation of HSC numbers after IR treatment, while numbers of haematopoietic progenitors are elevated to a lesser extent. IR rapidly induces Xpg both on mRNA and on protein level. Prevention of this induction does not influence activation of the checkpoint cascade, yet attenuates late checkpoint steps such as induction of p21 and Noxa. This causes a leaky cell cycle arrest and lower levels of apoptosis, both contributing to increased colony formation and transformation rates. Xpg thus helps to adequately induce DNA damage responses after IR, thereby keeping the expansion of damaged cells under control. This represents a new function of Xpg in the response to IR, in addition to its well-characterized role in nucleotide excision repair. PMID:27137888

  3. Genomic instability in rat: Breakpoints induced by ionising radiation and interstitial telomeric-like sequences

    International Nuclear Information System (INIS)

    The Norwegian rat (Rattus norvegicus) is the most widely studied experimental species in biomedical research although little is known about its chromosomal structure. The characterisation of possible unstable regions of the karyotype of this species would contribute to the better understanding of its genomic architecture. The cytogenetic effects of ionising radiation have been widely used for the study of genomic instability, and the importance of interstitial telomeric-like sequences (ITSs) in instability of the genome has also been reported in previous studies in vertebrates. In order to describe the unstable chromosomal regions of R. norvegicus, the distribution of breakpoints induced by X-irradiation and ITSs in its karyotype were analysed in this work. For the X-irradiation analysis, 52 foetuses (from 14 irradiated rats) were studied, 4803 metaphases were analysed, and a total of 456 breakpoints induced by X-rays were detected, located in 114 chromosomal bands, with 25 of them significantly affected by X-irradiation (hot spots). For the analysis of ITSs, three foetuses (from three rats) were studied, 305 metaphases were analysed and 121 ITSs were detected, widely distributed in the karyotype of this species. Seventy-six percent of all hot spots analysed in this study were co-localised with ITSs

  4. An isotopic analysis of ionising radiation as a source of sulphuric acid

    Directory of Open Access Journals (Sweden)

    M. B. Enghoff

    2012-06-01

    Full Text Available Sulphuric acid is an important factor in aerosol nucleation and growth. It has been shown that ions enhance the formation of sulphuric acid aerosols, but the exact mechanism has remained undetermined. Furthermore some studies have found a deficiency in the sulphuric acid budget, suggesting a missing source. In this study the production of sulphuric acid from SO2 through a number of different pathways is investigated. The production methods are standard gas phase oxidation by OH radicals produced by ozone photolysis with UV light, liquid phase oxidation by ozone, and gas phase oxidation initiated by gamma rays. The distributions of stable sulphur isotopes in the products and substrate were measured using isotope ratio mass spectrometry. All methods produced sulphate enriched in 34S and we find an enrichment factor (δ34S of 8.7 ± 0.4‰ (1 standard deviation for the UV-initiated OH reaction. Only UV light (Hg emission at 253.65 nm produced a clear non-mass-dependent excess of 33S. The pattern of isotopic enrichment produced by gamma rays is similar, but not equal, to that produced by aqueous oxidation of SO2 by ozone. This, combined with the relative yields of the experiments, suggests a mechanism in which ionising radiation may lead to hydrated ion clusters that serve as nanoreactors for S(IV to S(VI conversion.

  5. The study of some thiazinic and indaminic dye syntheses induced by ionising radiation

    International Nuclear Information System (INIS)

    With a view to finding some radiochemical reactions applicable on an industrial scale for evaluating the radioactive waste from nuclear reactors, a systematic study was made of the radiochemical synthesis of thiazinic dyes such as methylene blue and Lauths' violet, on which the first tests were carried out in 1954. The first part of the study concerned the identification and the dosage, during radiolysis, of dyes by means of their absorption spectra after separation from the reaction medium by adsorption chromatography or ion-exchange; other radiolysis products such as ammonium chloride and hydrogen peroxide were also identified. During a later stage by systematically varying the physico-chemical parameters it was possible to determine the most favourable conditions for radio-synthesis; the maximum radiochemical yields obtained had the following values: G (Lauths' violet) 1,65; G (Methylene blue) = 1,75. Furthermore, the study of the influence of variously substituted aminated products on the radiochemical yield showed the possibility of synthesising Bindsehedlers green and Wursters blue by radiochemical methods. Finally the discovery of a fundamental intermediate product, Wursters red, together with the kinetic study of the chemical synthesis of methylene blue made it possible to determine the main stages of the reaction mechanism and to decide which of these stages could be attributed to ionising radiations in the case of the radiochemical synthesis. (author)

  6. Low Dose-Rate Effects on Chromosomal Aberrations in Workers Occupationally Exposed to Ionising Radiation

    International Nuclear Information System (INIS)

    Full text: Occupational exposure to ionising radiation can be assessed by chromosomal aberrations detected in peripheral blood lymphocytes. Blood samples were collected from 47 occupationally exposed individuals (X-ray diagnostic machines and industrial gamma defectoscopy). The chromosomal aberrations were analysed from at least 500 metaphases per person and their frequencies were compared with those obtained from 110 control individuals. It has been noticed the higher frequency of chromosomal aberrations in the exposed group related to the control. The increase was analysed according to the age groups (31-40, 41-50, and 51-60), sex and duration of employment. The higher frequency of dicentrics was not directly correlated with the age or duration of employment in the exposed group. The acentric fragments were encountered with much higher frequency in the exposed group. The chromosomal aberrations induced by low dose-rate in occupationally exposed people revealed the degree of individual sensitivity and the severity of the initial damage depending on the biological-pathological conditions. (author)

  7. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Fehringer, F.; Seitz, G. [Berufsgenossenschaft der Feinmechanik und Elektrotechnik, Koln (Germany); Hammer, G.P.; Blettner, M. [Johannes Gutenberg-Universitat Mainz, Institut fur Medizinische Biometrie, Epidemiologie und Informatik des Klinikums (Germany)

    2006-07-01

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  8. Cancer mortality risk of nuclear power workers due to the exposure of ionising radiation in Germany

    International Nuclear Information System (INIS)

    A cohort study of German nuclear power workers was set up to investigate overall and cancer mortality risk related to a chronic exposure to ionising radiation of low-level dose. The German study was performed as a part of an international study carried out by the International Agency for Research on Cancer (IARC), Lyon. First results of the international study have been published recently [1]. German data are not yet included in this analysis. The German cohort consists of 4844 employees from 10 nuclear power plants. All persons who worked in these nuclear power plants in 1991 or started employment between 1991 und 1997 are included (except for employees of one plant, whose observation period started in 1992). These persons accumulated about 31,000 person years. Overall, 68 deaths were observed in the observation period between 1.1.1991-31.12.1997. Standardized mortality ratios (SMR) were computed for all causes of death, all cancers, cardiovascular diseases, external causes, and all other causes. Overall, a strong healthy worker effect was observed (SMR=0.52 [95% CI: 0.41;0.67]). No increase in total cancer mortality was seen (SMR=0.85 [95% CI: 0.53;1.30]). However, numbers are too small for stable risk estimates and further effort is under way to complete the cohort in terms of power plants and to extend the follow-up until 2005. (authors)

  9. Calibration, performance and type testing of personal dosemeters used in ionising-radiation applications in Greece.

    Science.gov (United States)

    Boziari, A; Hourdakis, C J

    2007-01-01

    Active Personal Dosemeters (APDs) are widely used in real-time personal dosimetry. Their performance, operational characteristics and limitations, as well as their calibration should be routinely checked to assure satisfactory operation and safe use. This study summarises the results of such type tests and calibrations performed in almost 4750 dosemeters at Ionising Radiation Calibration Laboratory (HIRCL) of Greek Atomic Energy Commission (GAEC). About 13.8% of the pencil type and 4.3% of the electronic dosemeters were found to be out of limits of acceptable performance. For the pencil type dosemeters, the mean calibration factor (CF+/-SD) for high- and low-dose categories was found to be 1.014+/-0.102 (range 0.793-1.458) and 0.995+/-0.059 (range 0.794-1.311), respectively. Of these >85% of them had reproducibility better than 90%, while <1% showed remarkable non-linearity and approximately 10% of them failed to retain the dose reading within the limits after 24 h. For the electronic dosemeters, the mean CF was 1.034+/-0.046 (range 0.967-1.238). The majority of them showed good reproducibility and linearity results while, after irradiation, the dose readings were not shifted through time. The energy response varies with the dosemeter type, reaching in one dosemeter type down to 50%. Both electronic and pencil did not showed electronic equilibrium problems. PMID:17185312

  10. Contamination on Lyman continuum emission at z >= 3: implication on the ionising radiation evolution

    CERN Document Server

    Vanzella, E; Cristiani, S; Nonino, M

    2010-01-01

    We investigate the possibility of contamination by lower-redshift interlopers in the measure of the ionising radiation escaping from high redshift galaxies. Taking advantage of the new ultra-deep VLT/VIMOS U-band number counts in the GOODS-S field,we calculate the expected probability of contamination by low-z interlopers as a function of the U-mag and the image spatial resolution (PSF). Assuming that ground-based observations can not resolve objects lying within a 0.5" radius of each other, then each z>=3 galaxy has a 2.1 and 3.2% chance of foreground contamination, adopting surface density U-band number counts down to 27.5 and 28.5,respectively. Those probabilities increase to 8.5 and 12.6%, assuming 1.0" radius. If applied to the estimates reported in the literature at z~3 for which a Lyman continuum has been observed directly,the probability that at least 1/3 of them are affected by foreground contamination is larger than 50%.From a Monte-Carlo simulation we estimate the median integrated contribution of ...

  11. Genomic instability in rat: Breakpoints induced by ionising radiation and interstitial telomeric-like sequences

    Energy Technology Data Exchange (ETDEWEB)

    Camats, Nuria [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Ruiz-Herrera, Aurora [Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Parrilla, Juan Jose [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Acien, Maribel [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Paya, Pilar [Servicio de Ginecologia y Obstetricia, Hospital Universitario Virgen de la Arrixaca, Ctra, Madrid-Cartagena, s/n, El Palmar, 30120 Murcia (Spain); Giulotto, Elena [Dipartimento di Genetica e Microbiologia Adriano Buzzati Traverso, Universita degli Studi di Pavia, 27100 Pavia (Italy); Egozcue, Josep [Departament de Biologia Cel.lular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Francisca [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain); Garcia, Montserrat [Institut de Biotecnologia i Biomedicina (IBB), Universitat Autonoma de Barcelona, 08193 Barcelona (Spain) and Departament de Biologia Cellular, Fisiologia i Immunologia Universitat Autonoma de Barcelona, 08193 Barcelona (Spain)]. E-mail: Montserrat.Garcia.Caldes@uab.es

    2006-03-20

    The Norwegian rat (Rattus norvegicus) is the most widely studied experimental species in biomedical research although little is known about its chromosomal structure. The characterisation of possible unstable regions of the karyotype of this species would contribute to the better understanding of its genomic architecture. The cytogenetic effects of ionising radiation have been widely used for the study of genomic instability, and the importance of interstitial telomeric-like sequences (ITSs) in instability of the genome has also been reported in previous studies in vertebrates. In order to describe the unstable chromosomal regions of R. norvegicus, the distribution of breakpoints induced by X-irradiation and ITSs in its karyotype were analysed in this work. For the X-irradiation analysis, 52 foetuses (from 14 irradiated rats) were studied, 4803 metaphases were analysed, and a total of 456 breakpoints induced by X-rays were detected, located in 114 chromosomal bands, with 25 of them significantly affected by X-irradiation (hot spots). For the analysis of ITSs, three foetuses (from three rats) were studied, 305 metaphases were analysed and 121 ITSs were detected, widely distributed in the karyotype of this species. Seventy-six percent of all hot spots analysed in this study were co-localised with ITSs.

  12. Profile of gene expression induced by ionising radiation in human CD4+ T lymphocytes

    International Nuclear Information System (INIS)

    Full text: Radiation-induced damage leads to different cellular responses including apoptosis, cell cycle arrest and transformation. Complex signalling pathways, some of which depend on the p53 status, regulate these responses. In an attempt to get more insight into the molecular mechanisms leading to radiation effects, several recent studies have used microarrays to analyse global gene regulation in peripheral blood lymphocytes. Few genes have been found to be modulated by ionising radiation. Interestingly, some genes have been identified as possible biomarkers of past exposure to radiation (Amundson, 2000; Kang, 2003). In this study, we further explored the cellular and molecular responses to radiation of different hematopoietic cell sub-populations. As a first step, we evaluated the response to irradiation of CD4+ T lymphocytes isolated from blood of three healthy donors. CD4+ T lymphocytes (97% purity), were irradiated ex vivo with 0.01, 0.1 and 1 Gy X-rays (250 kV- 15mA, 1mm Cu) and studied after 2, 8, 24 and 48h following radiation exposure. Apoptosis, measured as ROS (Reactive Oxygen Species) activity and sub G1 peak, increased with dose, becoming statistically significant only after 1 Gy. Programmed cell death also increased gradually with time after exposure, culminating at 25% 48 hours after 1Gy exposure. The patterns of gene induction over time and dose were tested by real-time quantitative RT-PCR on a limited number of candidate genes. One of these genes, DDB2 (DNA Damage Binding protein 2), was activated by 0.1Gy and 1Gy. Its activation was maximal after 1 Gy irradiation at 8h, averaging 8-9 fold for all three donors, and decreased at later time-points (24h and 48h). This dose and time-point were chosen for a large-scale gene expression analysis. cDNA from irradiated samples and sham controls were labelled with two different fluorochromes, mixed and hybridized to glass slide microarrays containing +/- 13.800 different human cDNAs spotted in duplicate

  13. Surveillance of health care workers exposed to ionising radiation: Rimed pilot study; Etude Rimed rayonnements ionisants en milieu medical. Etude de faisabilite. Rapport final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    The project so-called RIMED aimed to set up epidemiological surveillance of health care workers exposed to ionizing radiation. A pilot study was conducted in a sample of hospital personnel to examine the possibility of identifying exposed subjects in order to analyse mortality patterns according to occupational characteristics such as medical departments or occupations in a historical cohort. Seven hospitals participated in this pilot study. Health-care workers who had worn a dosimeter up to December 2003 were to be included in this cohort. The subjects' identification data were obtained from the SISERI (Systeme d'information de la surveillance de l'exposition aux rayonnements ionisants - Ionizing Radiation Exposure Monitoring Information System) database managed by the Institut de radioprotection et de surete nucleaire - Radiation Protection and Nuclear Safety Institute (IRSN). The SISERI system was in a 'pilot' phase in 2004. According to SISERI database, a total of 5126 subjects were found to have worn a dosimeter up to December 2003. The subjects' identification data were completed by the administrative services of the hospitals and occupational physicians searched for subjects' occupational data. Information required for the vital status search was satisfactorily completed only for 38% of the cohort subjects. This pilot study showed that obtaining data from SISERI database completed by hospital administrative data in 2004 led to a database of insufficient quality for epidemiological surveillance. The Institut de veille sanitaire (French Institute of Public Health Surveillance) recommends that transmission by the employers of some specific personal or occupational data of the exposed subjects should be made compulsory. In this way, SISERI system should be able to constitute any database with required quality for epidemiological surveillance of ionizing radiation exposed subjects. (authors)

  14. The use of ionising radiation from 60CO gamma source in controlling mouldiness in dried cocoa beans

    International Nuclear Information System (INIS)

    Mouldiness in stored cocoa beans in Ghana and the production of aflatoxin have been studied. Based on actual weight of discarded beans, mouldy beans have been estimated to constitute 0.13 % and 0.00002 % of marketable beans at the farmers' level and the buying agents' depots respectively in the Tafo District. This is contrasted with an estimated value of 0.16 % obtained in a questionnaire type study involving farmers. Estimated mouldy beans at the Tema port was 0.69 % per year (based on the cut test) representing a financial loss of $1,688,637.19 per year at $989/T should the mouldy beans be discarded. Fifty-eight (58) internally- and externally- borne fungal species were isolated from dried cocoa beans. Of these, forty-eight (48) were internally- borne and ten (10) were superficial. Twenty-nine (29) of the internally occurring fungi have been recorded for the first time on cocoa beans in Ghana. Twenty-six (26) of the fungi isolated belong to Aspergillus group. They included A. parasiticus and A. flavus, which can produce aflatoxins. Five (5) belong to Penicillium, eight (8) to Fusarium and nineteen (19) to other species. Ionising radiation effectively controlled fungi associated with mouldiness in cocoa beans in a dose - dependent manner. A radiation dose of 6 kGy completely inactivated the moulds. A. flavus and A. tamarii were the most radiation - resistant moulds encountered. The moisture content of the beans before, during and after irradiation influenced the effect of radiation. The relative humidity during storage and the type of packaging also influenced the radiation effect. Conidia of A. flavus subjected to moist heat at temperatures 20 0C to 60 0C for 2.5, 5 and 10 min respectively were not significantly affected by heating up to 50 0C. Heating an aqueous conidial suspension at 60 0C for at least 2.5 min reduced the number of fungal colonies by at least 5 log cycles when the suspension was assayed on agar plate media. Heating at 59 0C for 10 min

  15. External dosimetry for ionising radiation. From the national standard to the users in radiotherapy and radiation protection; La dosimetrie externe des rayonnements ionisants de la reference nationale aux utilisateurs en radiotherapie et en radioprotection

    Energy Technology Data Exchange (ETDEWEB)

    Bordy, J.M

    2009-07-01

    This report presents a review of the external dosimetry of the ionising radiations for the protection of the human being. Looking at this topic, at first we are confronted with its diversity: the protection of the workers and the public against radiations, the medical exposures for radiotherapy, diagnosis and surgery, and the accidental situations. These aspects are often artificially separated so that the global comprehension becomes more difficult. We underline the points of convergence and the bonds which exist between the concepts of dosimetry adopted to deal with its different aspects. It also appeared useful to avoid proposing a dictionary of definitions copied in the reports of the international commissions, and adopting the formalism of the ICRU reports. This is why the definitions, when they are essential, are put in appendix. This text presents the reasons which led to the adoption of the system of quantity used today for the external dosimetry of the ionising radiations. After an introduction dealing with the general principle, the first chapter deals with the 'physical' quantities and the methods used for the determination of the national references. The second chapter, through the protection against radiation of the workers and the public, describes the bonds between the measurable 'operational' quantities and the non measurable 'protections' quantities which allow establishing the radiation protection limits and check that they are respected. The third chapter deals with the difficulties encountered for the measurements in area and personal dosimetry. The fourth chapter deals with the specificities of the medical exposures with the 'practical' quantities, the principle of optimisation and how radiotherapy is implemented. The fifth chapter briefly describes the case of the concerted exposures and of the accident. In conclusion, we analyse the needs and some potential new avenues of work for the metrology of the

  16. The Swedish radiation protection institute's regulations on general obligations in medical and dental practices using ionising radiation; issued on April 28, 2000

    International Nuclear Information System (INIS)

    These regulations are applicable to medical and dental practices with ionising radiation used for medical exposures. The regulations are also applicable to exposures of persons who knowingly and willingly, other than as part of their occupation, support and comfort patients undergoing medical exposure

  17. Ionising radiation induced Nrf2-Keap1-ARE pathway and MRN complex mediated DNA repair

    International Nuclear Information System (INIS)

    Whole body exposure of low linear energy transfer (LET) ionising radiation damages the vital intracellular biomolecules due to the direct deposition of IR energy as well as through ionization/radiolysis of intracellular water molecules. A flux of reactive oxygen species (ROS) and free radicals i.e. superoxide anion (O2-), hydroxyl radical (OH), hydrogen peroxide (H2O2), and singlet oxygen (1O2) are generated, which disturb the normal redox homeostasis and lead to a state of 'oxidative stress'. The resultant lesions such as DNA base damage, single strand break (SSBs), double strands break (DSBs), and clustered DNA lesions together with the increased oxidative stress, activate multiple intracellular pathways where, some of the important pathways are oxidative stress regulating Nrf2-Keap1 antioxidant response element (ARE) pathway and MRN (Mre11/Rad50/Nbs1) complex mediated DNA DSBs repair (DDR) pathway. During oxidative stress conditions, Nrf2 acts as a potent transcription factor that binds on to the ARE sequence of DNA within the nucleus and induce gene expression of enzymatic and non-enzymatic antioxidants such as superoxide dismutase (SOD), catalase, heme oxygenase, NAD(P)H oxidoreductase quinone, glutathione peroxidase, glutathione, thioredoxin, and ferratin-12 etc. The radiation induced DNA DSBs γ-H2AX foci, recruit the MRN complex at the damage site. The MRN complex initiates a cascade of phosphorylation event which activate DNA damage response (DDR) protein kinases i.e. nuclear import of active ATM dimer, stabilization of p53 (cell cycle guardian protein) and its regulated p21 protein. The MRN complex together with its associated proteins direct the induction of cell cycle arrest, repair and apoptosis. Evidences suggest that during oxidative stress condition, Nrf2-ARE pathway is influenced by DDR protein p21. This review study offers the insight into the crosstalk between Nrf2-ARE pathway with MRN complex, p53 mediated p21 role in defense mechanism

  18. Phenolic compounds from red wine are protective against the DNA damaging effect of ionising radiation ex vivo

    International Nuclear Information System (INIS)

    Full text: Using the cytokinesis-block micronucleus assay we (a) investigated which compounds in red wine can prevent oxidative damage to DNA in vitro and (b) performed in vivo interventions with red wine (RW), de-alcoholised red wine (DEALC) and alcohol (ALC) to distinguish the effects of alcohol from the other fractions of RW in prevention of oxidative damage to DNA ex vivo. Cells were either challenged with ionising gamma radiation or hydrogen peroxide, two different forms of oxidative stress. The relative contribution of ethanol, glycerol, tartaric acid, catechin + caffeic acid, a mixture of all of these and phenolic stripped RW at in vivo relevant concentrations on spontaneous and oxidative stress induced DNA damage was evaluated in vitro. The results from these studies have shown that (a) only ethanol significantly increases spontaneous DNA damage, but this effect is eliminated when ethanol is included in a mixture of all the other wine components (P<0.05), (b) the strongest and only significant protective effect against hydrogen peroxide induced DNA damage was observed for the catechin + caffeic acid mixture (P<0.05) and (c) all compounds tested were significantly protective against ionising radiation-induced DNA damage in a dose dependent manner with the strongest protection being observed for the catechin + caffeic acid mixture and a mixture of all components (P < 0.0001). In the in vivo intervention studies with ex vivo challenge of whole blood showed that 1-2h after consumption of 300ml DEALC produced a significant protection against the DNA damaging effects of ionising radiation (P = 0.0002) but ALC significantly enhanced the damaging effects of ionising radiation (P 0.0002) while RW produced an intermediate effect. The data from these studies are particularly interesting because they clearly demonstrate the potential beneficial effects of wine phenolics in counteracting the harmful effects of ionising radiation. Furthermore they demonstrate that the

  19. Thermoluminescent properties of CVD diamond: applications to ionising radiation dosimetry; Proprietes thermoluminescentes du diamant CVD: applications a la dosimetrie des rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Petitfils, A

    2007-09-15

    Remarkable properties of synthetic diamond (human soft tissue equivalence, chemical stability, non-toxicity) make this material suitable for medical application as thermoluminescent dosimeter (TLD). This work highlights the interest of this material as radiotherapy TLD. In the first stage of this work, we looked after thermoluminescent (TL) and dosimetric properties of polycrystalline diamond made by Chemically Vapor Deposited (CVD) synthesis. Dosimetric characteristics are satisfactory as TLD for medical application. Luminescence thermal quenching on diamond has been investigated. This phenomenon leads to a decrease of dosimetric TL peak sensitivity when the heating rate increases. The second part of this work analyses the use of synthetic diamond as TLD in radiotherapy. Dose profiles, depth dose distributions and the cartography of an electron beam obtained with our samples are in very good agreement with results from an ionisation chamber. It is clearly shown that CVD) diamond is of interest to check beams of treatment accelerators. The use of these samples in a control of treatment with Intensity Modulated Radiation Therapy underlines good response of synthetic diamond in high dose gradient areas. These results indicate that CVD diamond is a promising material for radiotherapy dosimetry. (author)

  20. The ENEA calibration service for ionising radiations; Il centro di taratura per le radiazioni ionizzanti di Bologna. Parte 1: Fotoni

    Energy Technology Data Exchange (ETDEWEB)

    Monteventi, F.; Sermenghi, I. [ENEA, Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Ambiente

    1999-07-01

    The report describes all the facilities available at the the service of the ENEA Calibration Service for Ionising Radiations at Bologna (Italy). It gives a detailed description of all equipment qualified for photon fields metrology including the secondary standards and the calibration procedures performed for radiation monitoring devices and dosemeters. [Italian] Il presente lavoro descrive i servizi e le attivita' del Centro di Taratura dell'ENEA di Bologna, in particolare delle attrezzature qualificate per la metrologia fotonica, dei campioni di misura e delle procedure adottate per la taratura degli strumenti e dei dosimetri.

  1. Radiation safety and regulatory aspects of Industrial Ionising Radiation Gauging Devices (IRGD)

    International Nuclear Information System (INIS)

    In order to have an effective control on the use of these radiation sources and also to ensure the radiological safety of the user, as well as of the general public, the Government of India had promulgated the Radiation Protection Rules, 1971 under Atomic Energy Act, 1962. The Atomic Energy Regulatory Board (AERB) is the office of the competent authority for enforcing rules and regulations in respect of radiological safety

  2. Assessing the surroundings for effects of ionising radiation on the granting of permits, DOVIS A. Emissions to air and water

    International Nuclear Information System (INIS)

    In the Netherlands, as in most other countries, one generally needs a permit to produce (including the manufacture, processing, control and storage), to apply or to dispose of radioactive materials, or to use equipment that produces ionising radiation. This permit must be in accordance with the Nuclear Energy Act. Limits that are set for radioactive material can be found in the Decree on radiation protection ('Besluit stralings-bescherming') which has been in force since March 1, 2002. Along with the application for a permit, calculation results have to be submitted on the radiation dose that members of the public receive as a consequence of (possible) emissions of radioactive material (into the atmosphere or surface water) or as a consequence of external irradiation. Fairly rough estimates, based on simple rules, will often be satisfactory. These rules can be found in an annex of a Ministerial Order on the assessment of consequences of ionising radiation (mr-AGIS). However, in some cases this will not be adequate, for instance, where there are specific exposure pathways or when a certain specific pre-set criterion is not met. A more detailed assessment is needed in these cases. This report describes this more detailed assessment procedure as far as it concerns (possible) emissions of radioactive material into the atmosphere or surface water. Another report (DOVIS-B), produced by the Nuclear Research and consultancy Group (NRG), discusses the exposure to external radiation from radioactive sources or installations

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

  5. Radiation in the workplace-a review of studies of the risks of occupational exposure to ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wakeford, Richard [Dalton Nuclear Institute, The University of Manchester, Pariser Building-G Floor, PO Box 88, Sackville Street, Manchester M60 1QD (United Kingdom)], E-mail: Richard.Wakeford@manchester.ac.uk

    2009-06-01

    Many individuals are, or have been, exposed to ionising radiation in the course of their work and the epidemiological study of occupationally irradiated groups offers an important opportunity to complement the estimates of risks to health resulting from exposure to radiation that are obtained from other populations, such as the Japanese survivors of the atomic bombings of Hiroshima and Nagasaki in 1945. Moreover, workplace exposure to radiation usually involves irradiation conditions that are of direct relevance to the principal concern of radiological protection: protracted exposure to low level radiation. Further, some workers have been exposed to radioactive material that has been inadvertently taken into the body, and the study of these groups leads to risk estimates derived directly from the experience of those irradiated by these 'internal emitters', intakes of {alpha}-particle-emitters being of particular interest. Workforces that have been the subject of epidemiological study include medical staff, aircrews, radium dial luminisers, underground hard-rock miners, Chernobyl clean-up workers, nuclear weapons test participants and nuclear industry workers. The first solid epidemiological evidence of the stochastic effects of irradiation came from a study of occupational exposure to medical x-rays that was reported in 1944, which demonstrated a large excess risk of leukaemia among US radiologists; but the general lack of dose records for early medical staff who tended to experience the highest exposures hampers the derivation of risks per unit dose received by medical workers. The instrument dial luminisers who inadvertently ingested large amounts of radium-based paint and underground hard-rock miners who inhaled large quantities of radon and its decay products suffered markedly raised excess risks of, respectively, bone and lung cancers; the miner studies have provided standard risk estimates for radon-induced lung cancer. The large numbers of nuclear

  6. Radiation in the workplace-a review of studies of the risks of occupational exposure to ionising radiation.

    Science.gov (United States)

    Wakeford, Richard

    2009-06-01

    Many individuals are, or have been, exposed to ionising radiation in the course of their work and the epidemiological study of occupationally irradiated groups offers an important opportunity to complement the estimates of risks to health resulting from exposure to radiation that are obtained from other populations, such as the Japanese survivors of the atomic bombings of Hiroshima and Nagasaki in 1945. Moreover, workplace exposure to radiation usually involves irradiation conditions that are of direct relevance to the principal concern of radiological protection: protracted exposure to low level radiation. Further, some workers have been exposed to radioactive material that has been inadvertently taken into the body, and the study of these groups leads to risk estimates derived directly from the experience of those irradiated by these 'internal emitters', intakes of alpha-particle-emitters being of particular interest. Workforces that have been the subject of epidemiological study include medical staff, aircrews, radium dial luminisers, underground hard-rock miners, Chernobyl clean-up workers, nuclear weapons test participants and nuclear industry workers. The first solid epidemiological evidence of the stochastic effects of irradiation came from a study of occupational exposure to medical x-rays that was reported in 1944, which demonstrated a large excess risk of leukaemia among US radiologists; but the general lack of dose records for early medical staff who tended to experience the highest exposures hampers the derivation of risks per unit dose received by medical workers. The instrument dial luminisers who inadvertently ingested large amounts of radium-based paint and underground hard-rock miners who inhaled large quantities of radon and its decay products suffered markedly raised excess risks of, respectively, bone and lung cancers; the miner studies have provided standard risk estimates for radon-induced lung cancer. The large numbers of nuclear industry

  7. Radiation in the workplace-a review of studies of the risks of occupational exposure to ionising radiation

    International Nuclear Information System (INIS)

    Many individuals are, or have been, exposed to ionising radiation in the course of their work and the epidemiological study of occupationally irradiated groups offers an important opportunity to complement the estimates of risks to health resulting from exposure to radiation that are obtained from other populations, such as the Japanese survivors of the atomic bombings of Hiroshima and Nagasaki in 1945. Moreover, workplace exposure to radiation usually involves irradiation conditions that are of direct relevance to the principal concern of radiological protection: protracted exposure to low level radiation. Further, some workers have been exposed to radioactive material that has been inadvertently taken into the body, and the study of these groups leads to risk estimates derived directly from the experience of those irradiated by these 'internal emitters', intakes of α-particle-emitters being of particular interest. Workforces that have been the subject of epidemiological study include medical staff, aircrews, radium dial luminisers, underground hard-rock miners, Chernobyl clean-up workers, nuclear weapons test participants and nuclear industry workers. The first solid epidemiological evidence of the stochastic effects of irradiation came from a study of occupational exposure to medical x-rays that was reported in 1944, which demonstrated a large excess risk of leukaemia among US radiologists; but the general lack of dose records for early medical staff who tended to experience the highest exposures hampers the derivation of risks per unit dose received by medical workers. The instrument dial luminisers who inadvertently ingested large amounts of radium-based paint and underground hard-rock miners who inhaled large quantities of radon and its decay products suffered markedly raised excess risks of, respectively, bone and lung cancers; the miner studies have provided standard risk estimates for radon-induced lung cancer. The large numbers of nuclear industry

  8. How reliable are chromosomal aberration assays as bio markers of individual towards ionising radiation?

    International Nuclear Information System (INIS)

    Full text: Biomarkers of susceptibility or sensitivity towards ionising radiation can be important for the identification of individuals that may be at increased risk for the development of cancer after occupational, environmental or medical exposures. It is essential that these biomarkers have certain traits in order to be effective indicators of sensitivity. They should be specific, sensitive and reliable. Possible candidates for biomarkers of radiosensitivity are chromosomal aberrations. It has been shown that the induction of chromatid aberrations after irradiation of lymphocytes in G2 phase of the cell cycle and the induction of MN after irradiation in Go both allow discrimination between normal individuals and patients with cancer prone genetic diseases. In this study we investigated the inter- and intra- individual variation of the MN assay and the G2 assay in irradiated lymphocytes to assess their suitability as biomarkers of susceptibility. For this, the G2 assay and the MN assay were performed on blood samples of 10 healthy individuals. For the MN assay Go lymphocytes were exposed to 3.5 Gy Co γ-rays either at high dose-rate (HDR) and stimulated immediately or with 6h delay (DS) or at low dose-rate (LDR). For the G2 assay lymphocytes were irradiated with a dose of 0.4 Gy Co γ-rays in G2 phase of the cell cycle. Two individuals were assayed 9 times each in nine different experiments over a time period of 1 year. All samples were analysed by 2 scorers and no significant differences between them were observed using a paired t-test. The repeat experiments on blood samples of the same donor revealed that the inter-experimental/intra-individual coefficients of variation were not significantly different from the inter-individual coefficients of variation in both G2 and MN assay. As the intra-individual variability determines the assay reproducibility this would indicate that the assays are not able to detect real, reproducible differences in radiation

  9. Assessing the surroundings for effects of ionising radiation on the granting of permits, DOVIS A. Emissions to air and water

    CERN Document Server

    Blaauboer, R O

    2002-01-01

    In the Netherlands, as in most other countries, one generally needs a permit to produce (including the manufacture, processing, control and storage), to apply or to dispose of radioactive materials, or to use equipment that produces ionising radiation. This permit must be in accordance with the Nuclear Energy Act. Limits that are set for radioactive material can be found in the Decree on radiation protection ('Besluit stralings-bescherming') which has been in force since March 1, 2002. Along with the application for a permit, calculation results have to be submitted on the radiation dose that members of the public receive as a consequence of (possible) emissions of radioactive material (into the atmosphere or surface water) or as a consequence of external irradiation. Fairly rough estimates, based on simple rules, will often be satisfactory. These rules can be found in an annex of a Ministerial Order on the assessment of consequences of ionising radiation (mr-AGIS). However, in some cases this will not be ade...

  10. Microscopical examination: the impact of different ionising radiation doses over protective clothing used in the operating theatre

    Energy Technology Data Exchange (ETDEWEB)

    Abreu, M.J.; Cabec Silva, M.E. [Dept. de Engenharia Textil, Univ. do Minho, Guimaraees (Portugal); Schacher, L.; Adolphe, D. [Ecole Nationale Superieure des Industries Textiles de Mulhouse, Mulhouse (France)

    2004-07-01

    The goals to be pursued by this paper are to highlight the effect of different ionising radiation methods, considered low temperature sterilisation, over protective clothing (surgical gowns) used in the operating theatre through microscopical examination. In order to investigate the influence of the radiation on the properties of nonwoven-based surgical gowns, two types of radiation (gamma and electron beam radiation) were considered in this study. The scanning electron microscope (SEM) is widely used in studies of polymers, although for this kind of nonwoven based structures, that goes through sterilisation treatments it isn't commonly used. So, this paper also intends to relate the results of the evaluation of comfort and barrier properties after irradiated at several doses in a range from 0 to 160 kGy. (orig.)

  11. Lightning-driven inner radiation belt energy deposition into the atmosphere: implications for ionisation-levels and neutral chemistry

    Directory of Open Access Journals (Sweden)

    C. J. Rodger

    2007-08-01

    Full Text Available Lightning-generated whistlers lead to coupling between the troposphere, the Van Allen radiation belts and the lower-ionosphere through Whistler-induced electron precipitation (WEP. Lightning produced whistlers interact with cyclotron resonant radiation belt electrons, leading to pitch-angle scattering into the bounce loss cone and precipitation into the atmosphere. Here we consider the relative significance of WEP to the lower ionosphere and atmosphere by contrasting WEP produced ionisation rate changes with those from Galactic Cosmic Radiation (GCR and solar photoionisation. During the day, WEP is never a significant source of ionisation in the lower ionosphere for any location or altitude. At nighttime, GCR is more significant than WEP at altitudes <68 km for all locations, above which WEP starts to dominate in North America and Central Europe. Between 75 and 80 km altitude WEP becomes more significant than GCR for the majority of spatial locations at which WEP deposits energy. The size of the regions in which WEP is the most important nighttime ionisation source peaks at ~80 km, depending on the relative contributions of WEP and nighttime solar Lyman-α. We also used the Sodankylä Ion Chemistry (SIC model to consider the atmospheric consequences of WEP, focusing on a case-study period. Previous studies have also shown that energetic particle precipitation can lead to large-scale changes in the chemical makeup of the neutral atmosphere by enhancing minor chemical species that play a key role in the ozone balance of the middle atmosphere. However, SIC modelling indicates that the neutral atmospheric changes driven by WEP are insignificant due to the short timescale of the WEP bursts. Overall we find that WEP is a significant energy input into some parts of the lower ionosphere, depending on the latitude/longitude and altitude, but does not play a significant role in the neutral chemistry of the mesosphere.

  12. Predicting the effects of ionising radiation on ecosystems by a generic model based on the Lotka-Volterra equations

    Energy Technology Data Exchange (ETDEWEB)

    Monte, Luigi [ENEA CR Casaccia, Via P. Anguillarese 301 00100 Rome (Italy)], E-mail: luigi.monte@enea.it

    2009-06-15

    The present work describes a model for predicting the population dynamics of the main components (resources and consumers) of terrestrial ecosystems exposed to ionising radiation. The ecosystem is modelled by the Lotka-Volterra equations with consumer competition. Linear dose-response relationships without threshold are assumed to relate the values of the model parameters to the dose rates. The model accounts for the migration of consumers from areas characterised by different levels of radionuclide contamination. The criteria to select the model parameter values are motivated by accounting for the results of the empirical studies of past decades. Examples of predictions for long-term chronic exposure are reported and discussed.

  13. Predicting the effects of ionising radiation on ecosystems by a generic model based on the Lotka-Volterra equations

    International Nuclear Information System (INIS)

    The present work describes a model for predicting the population dynamics of the main components (resources and consumers) of terrestrial ecosystems exposed to ionising radiation. The ecosystem is modelled by the Lotka-Volterra equations with consumer competition. Linear dose-response relationships without threshold are assumed to relate the values of the model parameters to the dose rates. The model accounts for the migration of consumers from areas characterised by different levels of radionuclide contamination. The criteria to select the model parameter values are motivated by accounting for the results of the empirical studies of past decades. Examples of predictions for long-term chronic exposure are reported and discussed.

  14. Proposal for a Graded Authorisation Model for the Use of Ionising Radiation in Ireland

    International Nuclear Information System (INIS)

    The Radiological Protection Institute of Ireland RPII intends to refocus, streamline and modernise its regulation of the use of ionising radiation in Ireland. This report provides detailed proposals for establishing a graded approach to authorisation in which regulators will be able to focus on higher risk practices by simplifying requirements placed on those of lower risk, without compromising the safety or security of the Irish population. These proposals build on RPII strategic analyses that seek to navigate a course between the competing pressures of public sector reform and the rapid technological changes in medical and nuclear arenas, which challenge the licensing and advisory functions of RPII. A graded approach to authorisation provides the potential for a sustainable basis for future regulation in Ireland. Such an approach would be in line with the forthcoming EURATOM Basic Safety Standards and with general current regulatory trends, which are moving away from one-size-fits-all approaches towards more adaptive, interactive and transparent regulation. In seeking this reform, the RPII also aims to fully utilize the benefits of the internet and electronic communications and to improve the transparency of its processes. These proposals have been developed using a robust, comprehensive project methodology involving a root and branch analysis of current and potential future approaches to authorisation. A series of facilitated workshops were held, punctuated by intensive periods of focused co-enquiry, involving all members of the RPII Regulatory Service. This approach made the fullest use of the decades of expertise and knowledge of these staff. It also provided the platform for developing a common vision of a graded approach to authorisation; for agreeing the criteria for differentiating between levels of authorisation; for collecting the necessary evidence for decision-making and for identifying the implications of these decisions. The graded approach presented

  15. Internet-based ICRP resource for healthcare providers on the risks and benefits of medical imaging that uses ionising radiation.

    Science.gov (United States)

    Demeter, S; Applegate, K E; Perez, M

    2016-06-01

    The purpose of the International Commission on Radiological Protection (ICRP) Committee 3 Working Party was to update the 2001 web-based module 'Radiation and your patient: a guide for medical practitioners' from ICRP. The key elements of this task were: to clearly identify the target audience (such as healthcare providers with an emphasis on primary care); to review other reputable sources of information; and to succinctly publish the contribution made by ICRP to the various topics. A 'question-and-answer' format addressing practical topics was adopted. These topics included benefits and risks of imaging using ionising radiation in common medical situations, as well as pertaining to specific populations such as pregnant, breast-feeding, and paediatric patients. In general, the benefits of medical imaging and related procedures far outweigh the potential risks associated with ionising radiation exposure. However, it is still important to ensure that the examinations are clinically justified, that the procedure is optimised to deliver the lowest dose commensurate with the medical purpose, and that consideration is given to diagnostic reference levels for particular classes of examinations. PMID:27012846

  16. Implications for human and environmental health of low doses of ionising radiation

    International Nuclear Information System (INIS)

    The last 20 years have seen a major paradigm shift in radiation biology. Several discoveries challenge the DNA centric view which holds that DNA damage is the critical effect of radiation irrespective of dose. This theory leads to the assumption that dose and effect are simply linked – the more energy deposition, the more DNA damage and the greater the biological effect. This is embodied in radiation protection (RP) regulations as the linear-non-threshold (LNT) model. However the science underlying the LNT model is being challenged particularly in relation to the environment because it is now clear that at low doses of concern in RP, cells, tissues and organisms respond to radiation by inducing responses which are not readily predictable by dose. These include adaptive responses, bystander effects, genomic instability and low dose hypersensitivity, and are commonly described as stress responses, while recognizing that “stress” can be good as well as bad. The phenomena contribute to observed radiation responses and appear to be influenced by genetic, epigenetic and environmental factors, meaning that dose and response are not simply related. The question is whether our discovery of these phenomena means that we need to re-evaluate RP approaches. The so-called “non-targeted” mechanisms mean that low dose radiobiology is very complex and supra linear or sub-linear (even hormetic) responses are possible but their occurrence is unpredictable for any given system level. Issues which may need consideration are synergistic or antagonistic effects of other pollutants. RP, at present, only looks at radiation dose but the new (NTE) radiobiology means that chemical or physical agents, which interfere with tissue responses to low doses of radiation, could critically modulate the predicted risk. Similarly, the “health” of the organism could determine the effect of a given low dose by enabling or disabling a critical response. These issues will be discussed

  17. Second analysis of the National Registry for Radiation Workers. Occupational exposure to ionising radiation and mortality

    International Nuclear Information System (INIS)

    The National Registry for Radiation Workers (NRRW) is the largest epidemiological study of UK radiation workers. Following the first analysis published in 1992, a second analysis has been conducted based on an enlarged cohort of 124,743 workers, updated dosimetry and personal data for some workers, and a longer follow-up. Overall levels of mortality were less than those expected from national rates; the standardised mortality ratio (SMR) for all causes was 82, increasing to 89 after adjusting for social class. This 'healthy worker effect' was particularly strong for lung cancer and for some smoking-related non-malignant diseases. Analysis of potential radiation effects involved testing for any trend in mortality risk with external dose, after adjusting for likely confounding factors. For leukaemia excluding chronic lymphatic leukaemia (CLL) the central estimate of excess relative risk (ERR) per sievert (Sv) was similar to that estimated for the Japanese atomic bomb survivors at low doses (without the incorporation of a dose-rate correction factor); the corresponding 90% confidence limits for this trend were tighter than in the first analysis, ranging from just under four times the risk estimated at low doses from the Japanese A-bomb survivors to about zero. For the grouping of all malignancies other than leukaemia, the central estimate of the trend in risk with dose was closer to zero than in the first analysis; also, the 90% confidence limits were tighter than before and included zero. Since results for lung cancer and non-malignant smoking related diseases suggested the possibility of confounding by smoking, as in the first analysis an examination was made of all malignancies other than leukaemia and lung cancer. In this instance the central estimate of the ERR per Sv was similar to that from the A-bomb data (without the incorporation of a dose-rate correction factor), with a 90% confidence interval ranging from about four times the A-bomb value to less than zero

  18. Comparative evaluation of different approaches to environmental protection against ionising radiation in view of practicability and consistency

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, M.; Hornung, L.; Mundigl, S.; Kirchner, G. [Federal Office for Radiation Protection, Salzgitter, (Germany)

    2006-07-01

    International organisations, including ICRP, IAEA and UNSCEAR, and the international scientific community are currently engaged in work on the protection of non-human species against ionising radiation as a complement to the existing framework centred on humans. The basic ideas and conceptual approaches developed during the last decade substantially agree with each other. The EC funded FASSET project (Framework for Assessment of Environmental Impact) summarizes and reviews the current knowledge of radiation effects on biota, provides basic dosimetric models for fauna and flora and suggests an assessment framework. Protection of the environment against ionising radiation, on the one hand, aims to close a conceptual gap in radiation protection. Therefore, current frameworks for environmental protection conceptually follow radiation protection of man. On the other hand, preservation of natural resources, habitats and the biological diversity are common objectives of environmental protection against radioactive as well as chemical pollutants, suggesting an integrated approach based on the fundamental ideas of conventional environmental protection. In essence, a conceptual framework encompassing protection of man as well as of fauna and flora against chemical and radioactive pollutants would be highly desirable in view of coherence, consistency and transparency. Such an umbrella concept communicates the positive message that similar issues are treated in a conceptually similar manner, thus facilitating scientific justification and public communication and increasing acceptance. This paper discusses different concepts and approaches to radiation protection of man, radiation protection of non-human biota and environmental protection against chemical pollutants, identifies common principles and differences, addresses conflicting requirements and evaluates the feasibility and limitations of such an encompassing framework. (authors)

  19. Comparative evaluation of different approaches to environmental protection against ionising radiation in view of practicability and consistency

    International Nuclear Information System (INIS)

    International organisations, including ICRP, IAEA and UNSCEAR, and the international scientific community are currently engaged in work on the protection of non-human species against ionising radiation as a complement to the existing framework centred on humans. The basic ideas and conceptual approaches developed during the last decade substantially agree with each other. The EC funded FASSET project (Framework for Assessment of Environmental Impact) summarizes and reviews the current knowledge of radiation effects on biota, provides basic dosimetric models for fauna and flora and suggests an assessment framework. Protection of the environment against ionising radiation, on the one hand, aims to close a conceptual gap in radiation protection. Therefore, current frameworks for environmental protection conceptually follow radiation protection of man. On the other hand, preservation of natural resources, habitats and the biological diversity are common objectives of environmental protection against radioactive as well as chemical pollutants, suggesting an integrated approach based on the fundamental ideas of conventional environmental protection. In essence, a conceptual framework encompassing protection of man as well as of fauna and flora against chemical and radioactive pollutants would be highly desirable in view of coherence, consistency and transparency. Such an umbrella concept communicates the positive message that similar issues are treated in a conceptually similar manner, thus facilitating scientific justification and public communication and increasing acceptance. This paper discusses different concepts and approaches to radiation protection of man, radiation protection of non-human biota and environmental protection against chemical pollutants, identifies common principles and differences, addresses conflicting requirements and evaluates the feasibility and limitations of such an encompassing framework. (authors)

  20. Field studies on long term ecosystem consequences of ionising radiation and chemical pollutants (EANOR Project)

    International Nuclear Information System (INIS)

    -barcoding, invertebrate DNA barcoding, DNA methylation, and other molecular endpoints is ongoing, together with studies of possible adaptation of plants, invertebrates and microorganisms. Preliminary results show significant differences in diversity for many species between contaminated and reference sites. However, more research is needed to draw conclusions about the cause of such observations. Nevertheless, by combining a through site characterisation and exposure assessment with a variety of ecologically relevant biomarker and endpoint measurements, the data produced should be a valuable contribution to international activities looking at the impacts of chronic exposure of ionising radiation on non-human species. Project participants: Elena Belykh, Anna Kaneva, Boris Kondratenok, Alla Kolesnikova, Alexey Kurdin, Tatinana Majstrenko, Taskayeva Anastasia Oleshya Vakhrusheva, Illa Velegzhaninov, Vladimir Zainullin (IoB, Komi Republic, Russia); S. Haciyakupoglu (Istanbul Technical University, Turkey); Rahime Oral, Sabriye Yusan, Filiz Gur Filiz (Ege University, Turkey); Murat Belivermis, Onder Kilic (Istanbul University, Turkey); Fatma Kocbas (Celal Bayar University, Turkey); Mustafa Akiner, (Rize University, Turkey); Claire Coutris, Erik Joner (Bioforsk, Norway); Turid Hertel-Aas, Emmanuel Lapied, Yevgeniya Tomkiv, Brit Salbu, Lindis Skipperud (Centre for Environmental Radioactivity, UMB, Norway). Document available in abstract form only. (authors)

  1. Field studies on long term ecosystem consequences of ionising radiation and chemical pollutants (EANOR Project)

    Energy Technology Data Exchange (ETDEWEB)

    Oughton, D. [Centre for Environmental Radioactivity - CERAD (Norway); Evseeva, T. [Institute of Biology RAS (Russian Federation); Erenturk, S. [Istanbul Technical University (Turkey)

    2014-07-01

    -barcoding, invertebrate DNA barcoding, DNA methylation, and other molecular endpoints is ongoing, together with studies of possible adaptation of plants, invertebrates and microorganisms. Preliminary results show significant differences in diversity for many species between contaminated and reference sites. However, more research is needed to draw conclusions about the cause of such observations. Nevertheless, by combining a through site characterisation and exposure assessment with a variety of ecologically relevant biomarker and endpoint measurements, the data produced should be a valuable contribution to international activities looking at the impacts of chronic exposure of ionising radiation on non-human species. Project participants: Elena Belykh, Anna Kaneva, Boris Kondratenok, Alla Kolesnikova, Alexey Kurdin, Tatinana Majstrenko, Taskayeva Anastasia Oleshya Vakhrusheva, Illa Velegzhaninov, Vladimir Zainullin (IoB, Komi Republic, Russia); S. Haciyakupoglu (Istanbul Technical University, Turkey); Rahime Oral, Sabriye Yusan, Filiz Gur Filiz (Ege University, Turkey); Murat Belivermis, Onder Kilic (Istanbul University, Turkey); Fatma Kocbas (Celal Bayar University, Turkey); Mustafa Akiner, (Rize University, Turkey); Claire Coutris, Erik Joner (Bioforsk, Norway); Turid Hertel-Aas, Emmanuel Lapied, Yevgeniya Tomkiv, Brit Salbu, Lindis Skipperud (Centre for Environmental Radioactivity, UMB, Norway). Document available in abstract form only. (authors)

  2. Radio-oxidation of an EPDM elastomer under weak or strong ionising radiations: measurement and modelling of dioxygen consumption

    International Nuclear Information System (INIS)

    Usually, the irradiation of polymers under ionising radiations occurs in air that is in the presence of oxygen. This leads to a radio oxidation process and to oxygen consumption. Our material is an EPDM elastomer (ethylene propylene 1,4 hexadiene) used as insulator in control-command cables in nuclear plants (Pressurised Water Reactor). A specific device has been conceived and built up during this PhD work for measuring very small oxygen consumptions with an accuracy of around 10%. Ionising radiations used are electrons at 1 MeV and carbon ions at 11 MeV per nucleon. Under both electron and ion irradiations, the influence of oxygen pressure on oxygen consumption has been studied in a very large range: between 1 and 200 mbar. In both cases, the yield of oxygen consumption is constant in-between 200 and 5 mbar. Then, at lower pressures, it decreases appreciably. On the other hand, the oxygen consumption during ion irradiation is four times smaller than during electron irradiation. This emphasizes the role of the heterogeneity of the energy deposition at a nano-metric scale. The adjustment of the experimental results obtained during electron irradiation with the general homogeneous steady-state kinetic model has allowed extracting all the values of the kinetic parameters for the chosen mechanism of radio oxidation. The knowledge of these numbers will allow us to face our results obtained during ion irradiation with a heterogeneous kinetic model under development. (author)

  3. Medical and Dental Guidance Notes. A Good Practice Guide on all Aspects of Ionising Radiation Protection in the Clinical Environment

    International Nuclear Information System (INIS)

    Institute of Physics and Engineering in Medicine York: IPEM 225 pp, ISBN: 1-903613-09-4. This book is the much awaited replacement for the old yellow 'Guidance Notes' published in 1988 by the National Radiological Protection Board (NRPB). Since then nearly all Regulations covering the use of ionising radiation have been updated. The Institute of Physics and Engineering in Medicine (IPEM) established a working group in 1999 to produce a first draft for consultation (produced in April 2000) and to consider subsequent comments to this draft. The final document, published by IPEM, is therefore the end product of numerous contributions from professionals working in healthcare and wide consultation with professional bodies, the NRPB, UK Health Departments, Environment Agencies and the HSE. The notes provide general guidance on good practice - not just legal requirements. Radiation Protection Advisers and Medical Physics Experts may well have instigated slightly different arrangements locally. The publication has been available in electronic form on the IPEM website ( www.ipem.org.uk/publications/IRR99.html) for a few months. This has been useful for quick access to advice and for searching for particular topics but is difficult to read in large sections. Although it can be downloaded, the main documented is protected so that it can not be printed and specific text can not be 'cut and pasted'. The appendices are in a separate file that can be printed. Although the chapter paragraph numbers are consistent between the electronic and papers versions, the page numbers are different. The new guidance is ring bound, so, apart from at the beginning and end of the book, it is generally easy to open it out and lay it flat. The book consists of 19 chapters and 21 appendices and, with 225 pages, is considerably more extensive than the old notes. It begins with the general measures for radiation protection followed by radiation protection of persons undergoing medical exposures

  4. Application of the Alkaline Comet Assay and the Analysis of Structural Chromosome Aberrations in Assessment of Genetic Damage After Accidental Exposure to Ionising Radiation

    International Nuclear Information System (INIS)

    Full text: Living with the effects of low-level ionising radiation is one of the normal hazards of life. However, the effects of lower doses may not show up for years after exposure and are due to various changes in DNA molecules and chromosomes. Radiation-induced mutations seem to be brought about by the deletion of small pieces of chromosomes during the process of chromosome breakage and repair. Since chromosome damage is most likely to happen in dividing cells, ionising radiation usually cause cancer in those parts of the body where cells are actively dividing. Ionising radiation kills rapidly dividing cells, blood lymphocytes among them. People are exposed to high doses of ionising radiation when radiation accidents occur. The cytogenetical consequences of accidental exposure to gamma-radiation (radiation dose 221 mSv) were investigated by using alkaline Comet assay and the analysis of structural chromosomal aberrations (CA). Blood samples were repeatedly collected during one-year period after the accident. By using the Comet assay immediately after accidental exposure a high level of DNA damage was recorded. Although this level was decreasing over a one-year period, it was still elevated compared to normal values of DNA damage for unexposed persons. Immediately after the accident prevalence of CA (dicentrics, acentrics) over chromatid aberrations was recorded. However, one year afterwards only a few chromatid breaks were recorded. Our results confirmed usefulness of the alkaline Comet assay as a simple and sensitive technique for the biomonitoring of DNA damages, especially in the cases of accidental exposure to ionising radiation. (author)

  5. Apoptosis is signalled early by low doses of ionising radiation in a radiation-induced bystander effect

    International Nuclear Information System (INIS)

    Highlights: ► Molecular mechanisms involved in the production of a radiation induced bystander effect are not well known. ► We investigate gene expression changes in apoptotic genes in both direct and bystander responses. ► We demonstrate initiation of the apoptotic cascade in a bystander response. ► Lower doses reveal a specific but differential response related to apoptosis compared to higher doses. - Abstract: It is known that ionising radiation (IR) induces a complex signalling apoptotic cascade post-exposure to low doses ultimately to remove damaged cells from a population, specifically via the intrinsic pathway. Therefore, it was hypothesised that bystander reporter cells may initiate a similar apoptotic response if exposed to low doses of IR (0.05 Gy and 0.5 Gy) and compared to directly irradiated cells. Key apoptotic genes were selected according to their role in the apoptotic cascade; tumour suppressor gene TP53, pro-apoptotic Bax and anti-apoptotic Bcl2, pro-apoptotic JNK and anti-apoptotic ERK, initiator caspase 2 and 9 and effector caspase 3, 6 and 7. The data generated consolidated the role of apoptosis following direct IR exposure for all doses and time points as pro-apoptotic genes such as Bax and JNK as well as initiator caspase 7 and effector caspase 3 and 9 were up-regulated. However, the gene expression profile for the bystander response was quite different and more complex in comparison to the direct response. The 0.05 Gy dose point had a more significant apoptosis gene expression profile compared to the 0.5 Gy dose point and genes were not always expressed within 1 h but were sometimes expressed 24 h later. The bystander data clearly demonstrates initiation of the apoptotic cascade by the up-regulation of TP53, Bax, Bcl-2, initiator caspase 2 and effector caspase 6. The effector caspases 3 and 7 of the bystander samples demonstrated down-regulation in their gene expression levels at 0.05 Gy and 0.5 Gy at both time points therefore not

  6. Apoptosis is signalled early by low doses of ionising radiation in a radiation-induced bystander effect

    Energy Technology Data Exchange (ETDEWEB)

    Furlong, Hayley, E-mail: hayley.furlong@dit.ie [DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland); School of Biological Sciences, College of Sciences and Health, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland); Mothersill, Carmel [Medical Physics and Applied Radiation Sciences, Nuclear Research Building, 1280 Hamilton, Ontario L8S 4K1 (Canada); Lyng, Fiona M. [DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland); Howe, Orla [DIT Centre for Radiation and Environmental Science, Focas Research Institute, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland); School of Biological Sciences, College of Sciences and Health, Dublin Institute of Technology, Kevin St, Dublin 8 (Ireland)

    2013-01-15

    Highlights: ► Molecular mechanisms involved in the production of a radiation induced bystander effect are not well known. ► We investigate gene expression changes in apoptotic genes in both direct and bystander responses. ► We demonstrate initiation of the apoptotic cascade in a bystander response. ► Lower doses reveal a specific but differential response related to apoptosis compared to higher doses. - Abstract: It is known that ionising radiation (IR) induces a complex signalling apoptotic cascade post-exposure to low doses ultimately to remove damaged cells from a population, specifically via the intrinsic pathway. Therefore, it was hypothesised that bystander reporter cells may initiate a similar apoptotic response if exposed to low doses of IR (0.05 Gy and 0.5 Gy) and compared to directly irradiated cells. Key apoptotic genes were selected according to their role in the apoptotic cascade; tumour suppressor gene TP53, pro-apoptotic Bax and anti-apoptotic Bcl2, pro-apoptotic JNK and anti-apoptotic ERK, initiator caspase 2 and 9 and effector caspase 3, 6 and 7. The data generated consolidated the role of apoptosis following direct IR exposure for all doses and time points as pro-apoptotic genes such as Bax and JNK as well as initiator caspase 7 and effector caspase 3 and 9 were up-regulated. However, the gene expression profile for the bystander response was quite different and more complex in comparison to the direct response. The 0.05 Gy dose point had a more significant apoptosis gene expression profile compared to the 0.5 Gy dose point and genes were not always expressed within 1 h but were sometimes expressed 24 h later. The bystander data clearly demonstrates initiation of the apoptotic cascade by the up-regulation of TP53, Bax, Bcl-2, initiator caspase 2 and effector caspase 6. The effector caspases 3 and 7 of the bystander samples demonstrated down-regulation in their gene expression levels at 0.05 Gy and 0.5 Gy at both time points therefore not

  7. Influence of SNP Polymorphisms in DNA Repair Genes on the Level of Persistent Damage in Human Lymphocytes After Exposure to 2 Gy of Ionising Radiation

    International Nuclear Information System (INIS)

    Variation in cell response to ionising radiation could be result of changes in gene expression and/or polymorphisms of DNA repair genes. The aim of the study was to estimate the DNA damage level in human lymphocytes after exposure to 2 Gy of ionising radiation. Medical workers occupationally exposed to low doses of ionising radiation (N = 20) and matched controls (N 20) were genotyped for polymorphic hOGG1, XRCC1, APE1, XPD10, XPD23, XRCC3, PARP1 and MGMT genes. Micronucleus (MN) test was used for the estimation of DNA damage before and after radiation. Incidence of MN in irradiated samples positively correlated with age and negatively with polymorphic variants of XPD23. Significant difference was observed between irradiated homozygotes (HO) and heterozygotes (HE). HO and HE APE1 differed in MN before exposure. HO and polymorphic variants of XPD10 differed in MN after exposure. Gender showed different MN in the exposed group after exposure. Age correlated positively with MN after exposure, working probation and received dose. Multiple regression analysis revealed connection between polymorphic variants of APE1 and XRCC3 with MN before exposure. These results confirm the value of micronucleus assay in DNA damage estimation and suggest possible use of polymorphic genes in monitoring of individuals professionaly exposed to ionising radiation. (author)

  8. Fourth IRMF comparison of calibrations of portable gamma-ray dose- rate monitors 2001-2002 Ionising radiation

    CERN Document Server

    Lewis, V E

    2002-01-01

    The Ionising Radiations Metrology Forum (IRMF) organised a fourth comparison of calibrations of gamma-ray dose-rate monitors in which fifteen establishments in the UK participated. The exercise involved the circulation of three gamma-ray monitors for calibration in the fields produced using sup 1 sup 3 sup 7 Cs, sup 2 sup 4 sup 1 Am and sup 6 sup 0 Co. The instruments used were an Electra with MC 20 probe, a Mini-Instruments Mini-rad 1000 and a Siemens electronic personal dosemeter Mk 2 (EPD). The responses relative to 'true' dose equivalent rate were calculated by the individual participants and submitted to the for analysis along with details of the facilities and fields employed. Details of the estimated uncertainties were also reported. The results are compared and demonstrate generally satisfactory agreement between the participating establishments. However, the participants' treatment of uncertainties needs improvement and demonstrates a need for guidance in this area.

  9. For the development of therapy with ionising radiation in tooth, mouth and jaw medicine. An historical summary

    International Nuclear Information System (INIS)

    Based on the corresponding literature study, the development of therapy with ionising radiation, especially in the areas of tooth, mouth and jaw medicine, is reported from the discovery of X-rays up till the present. First from 1915 on did the X-ray antiphlogistic irradiation with in importance, from 1925 to about 1940 it played a domineering role, after the war was hardly still in use and since 1970 is considered in the stomatological sector obsolete. In comparison, already in 1905 there were individual successes in tumor therapy using X radiation. After many failures and competition with the method of radium therapy in the following years, a new upswing in X-radiation came starting in around 1930 with the introduction of the Chaoul contact therapy. The high point of this development is the introduction of supervolt therapy starting around 1965. It is the result of comprehensive research in the area of radiation physics. As a result of further developed techniques there were soon combined and competing procedures available, whose results, however, have not been adequately compared and documented. From 1970 on electronic data processing has primarily taken over individual irradiation planning (cobalt 60 and electron irradiation), predictions about clinically relevant therapy successes are not present at this time. (TRV)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-01

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

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

    International Nuclear Information System (INIS)

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

  12. Occupational exposure to ionising radiation 1990-1996. Analysis of doses reported to the Health and Safety Executive's Central Index of Dose Information

    International Nuclear Information System (INIS)

    The Central Index of Dose Information (CIDI) is the Health and Safety Executive's (HSE's) national database of occupational exposure to ionising radiation. It is operated under contract by the National Radiological Protection Board (NRPB). CIDI receives annually, from Approved Dosimetry Services (ADS) summaries of radiation doses recorded for employees designated as classified persons in the United Kingdom. This is the second analysis of dose summary information to be published. (author)

  13. [Low dose ionising radiation and cancer: findings and methods. Report of a meeting and consequences for Switzerland].

    Science.gov (United States)

    Schüler, G; Gutzwiller, F

    1991-01-01

    Today's society is concerned about the dangers of ionising radiation, especially in the aftermath of Chernobyl. On the other hand, there exists a widespread lack of understanding radiation biology and radioepidemiology--the very sciences which provide the data from which today's risk estimates have been derived. The papers in this issue of the Journal were presented at a workshop on "Low level radiation and cancer: data and methods" held on 10th-11th December in Feuisberg, near Zurich. The meeting was organised by the Institute of Social and Preventive Medicine of the University of Zurich under the auspices of the Swiss Federal Office of Public Health. Its aims were threefold. First, to give an introduction to some basic facts and methodological issues in radiation physics, biology and epidemiology. Secondly, to give an overview of the availability of data for radioepidemiological research in Switzerland and, thirdly, to evaluate possible research strategies in this country. A list of some notions and units commonly used in the radiation sciences serves an an introduction to the field (G. Schüler et al.). In using units and notions it is important to distinguish the description of biological experiments and epidemiological observations from definitions and risk projections proposed by international reports and consensus bodies for radioprotection purposes. The next papers deal more specifically with selected aspects of the basic sciences. Dosimetry means quantifying the physical effects of ionizing radiation in human tissue; this is not a straight-forward procedure (I. Cordt). The foundations of general radiation biology are succinctly summarised by C. Michel. An account of our present knowledge and theories of radiation carcinogenesis is provided by W. Burkart. W Lutz compares dose-response models of chemical carcinogenesis with those used in radiation carcinogenesis. During the last decade the epidemiological foundations of radioprotection have changed

  14. Estimation of annual occupational effective doses from external ionising radiation at medical institutions in Kenya

    OpenAIRE

    Geoffrey K Korir; Jeska S. Wambani; Ian K Korir

    2011-01-01

    This study details the distribution and trends of doses from occupational radiation exposure among radiation workers from participating medical institutions in Kenya, where monthly dose measurements were collected for a period of one year (January to December 2007) using thermoluminescent dosimeters. A total of 367 medical radiation workers were monitored, comprising 27% radiologists, 2% oncologists, 4% dentists, 5% physicists, 45% technologists, 4% nurses, 3% film processor technicians, 4% a...

  15. The Council of Europe teaching modules - ionising radiation and protection of man

    International Nuclear Information System (INIS)

    An outline review is presented of the modular training course prepared for the training of staff responsible for radiological protection, particularly those people not working full-time in radiological protection, but in fringe fields where a working knowledge of the subject is required. The lecture part of the course is intended to occupy 60 hours and is divided into six sections, covering the fundamentals of nuclear physics, radiation quantities and units, the principles of radiation detection, biological aspects, the principles of radiation protection, dose equivalents, dose limitation, natural and man-made sources of radiation, and legal aspects. (U.K.)

  16. Potential role of intense ionising radiation sources in municipal sludge management and environmental protection

    International Nuclear Information System (INIS)

    Magnitude of the problem of safe disposal of sewage and sludge is explained. With rapid increase in the quantum of generated municipal and industrial wastes, their disposal on land or in sea is becoming harmful to public health, hazardous to aquatic life and disturbing to ecological balance. These wastes can be recycled, but to make this recycling beneficial and at the same time harmless to public health, the wastes must be disinfected. Radiation disinfection of sewage and sludge is examined as one of the ways of disinfection. Irradiation can be carried out with gamma radiation or energised electrons. Techniques of radiation disinfection and radiation doses required for disinfection are discussed. Case studies of a few radiation plants for sludge disinfection are presented. They include the Palmdale Plant in Florida, Sandia Irradiator at Albuqurque, New Mexico, Energised Electron Facility at Deer Island, Boston - all these in U.S.A., and the Munich Plant in West Germany. Mention has been made to the work in progress in India on the design of irradiators. Reference has been made to the proposed electron irradiation system for destruction of toxic chemicals such as PCB in drinking water and for disinfection of secondary water. Economics of radiation disinfection is also discussed and it is noted that the radiation process can become economically competitive when cheap sources of radiation become available. (M.G.B.)

  17. Food ionisation. Realities and perspectives

    International Nuclear Information System (INIS)

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  18. Functional characterisation of an Arabidopsis gene strongly induced by ionising radiation: the gene coding the poly(ADP-ribose)polymerase-1 (AthPARP-1)

    International Nuclear Information System (INIS)

    Arabidopsis thaliana, the model-system in plant genetics, has been used to study the responses to DNA damage, experimentally introduced by γ-irradiation. We have characterised a radiation-induced gene coding a 111 kDa protein, AthPARP-1, homologous to the human poly(ADP-ribose)polymerase-1 (hPARP-1). As hPARP-1 is composed by three functional domain with characteristic motifs, AthPARP-1 binds to DNA bearing single-strand breaks and shows DNA damage-dependent poly(ADP-ribosyl)ation. The preferential expression of AthPARP-1 in mitotically active tissues is in agreement with a potential role in the maintenance of genome integrity during DNA replication, as proposed for its human counterpart. Transcriptional gene activation by ionising radiation of AthPARP-1 and AthPARP-2 genes is to date plant specific activation. Our expression analyses after exposure to various stress indicate that 1) AthPARP-1 and AthPARP-2 play an important role in the response to DNA lesions, particularly they are activated by genotoxic agents implicating the BER DNA repair pathway 2) AthPARP-2 gene seems to play an additional role in the signal transduction induced by oxidative stress 3) the observed expression profile of AthPARP-1 is in favour of the regulation of AthPARP-1 gene expression at the level of transcription and translation. This mode of regulation of AthPARP-1 protein biosynthesis, clearly distinct from that observed in animals, needs the implication of a so far unidentified transcription factor that is activated by the presence of DNA lesions. The major outcome of this work resides in the isolation and characterisation of such new transcription factor, which will provide new insight on the regulation of plant gene expression by genotoxic stress. (author)

  19. Determination of relevant parameters for the use of electronic dosemeters in pulsed fields of ionising radiation

    International Nuclear Information System (INIS)

    Active electronic dosemeters using counting techniques are used for radioprotection purposes in pulsed radiation fields in X-ray diagnostics or therapy. The disadvantage of the limited maximum measurable dose rate becomes significant in these radiation fields and leads to some negative effects. In this study, a set of relevant parameters for a dosemeter is described, which can be used to decide whether it is applicable in a given radiation field or not. The determination of these relevant parameters-maximum measurable dose rate in the radiation pulse, dead time of the dosemeter, indication per counting event and measurement cycle time-is specified. The results of the first measurements on the determination of these parameters for an electronic personal dosemeter of the type Thermo Fisher Scientific EPD Mk2 are shown. (authors)

  20. Considerations concerning the use of counting active personal dosimeters in pulsed fields of ionising radiation.

    Science.gov (United States)

    Ambrosi, Peter; Borowski, Markus; Iwatschenko, Michael

    2010-06-01

    Active personal electronic dosimeters (APDs) exhibit limitations in pulsed radiation fields, which cannot be overcome without the use of new detection technology. As an interim solution, this paper proposes a method by which some conventional dosimeters can be operated in a way such that, based on the basic knowledge about the pulsed radiation field, any dosimetric failure of the dosimeter is signalised by the instrument itself. This method is not applicable to all combinations of APD and pulsed radiation field. The necessary requirements for the APD and for the parameters of the pulsed radiation field are given in the paper. Up to now, all such requirements for APDs have not been tested or verified in a type test. The suitability of the method is verified for the use of one APD used in two clinical pulsed fields. PMID:20083488

  1. The effect of combined modality treatment with ionising radiation and TPPS-mediated photodynamic therapy on murine tail skin

    International Nuclear Information System (INIS)

    The effect on normal skin of combined modality treatment with 300 kV X-rays and photodynamic therapy (PDT) using the photosensitising drug meso-tetra (sulphonatophenyl) porphine (TPPS) was studied using the mouse tail necrosis assay. Prior treatment with a tolerance dose of PDT produced a significant increase in the probability of necrosis following graded doses of ionising radiation. A tolerance dose of X-rays administered prior to graded doses of PDT also produced a significant rise in the necrosis rate. TPPS appeared to have a radiosensitising effect but, as the animals were kept in subdued light, the low dose of PDT they therefore received may provide an alternative explanation. The effect of prolonging the interval between the modalities on the necrosis rate did not appear to be related to the time course of either the changes in blood flow produced by each modality, measured by zenon clearance studies or the development of the skin reaction following X-ray irradiation. (author)

  2. Protection of the environment from ionising radiation in a regulatory context-an overview of the PROTECT coordinated action project

    International Nuclear Information System (INIS)

    The outcome of the PROTECT project (Protection of the Environment from Ionising Radiation in a Regulatory Context) is summarised, focusing on the protection goal and derivation of dose rates which may detrimentally affect wildlife populations. To carry out an impact assessment for radioactive substances, the estimated dose rates produced by assessment tools need to be compared with some form of criteria to judge the level of risk. To do this, appropriate protection goals need to be defined and associated predefined dose rate values, or benchmarks, derived and agreed upon. Previous approaches used to estimate dose rates at which there may be observable changes in populations or individuals are described and discussed, as are more recent derivations of screening benchmarks for use in regulatory frameworks. We have adopted guidance and procedures used for assessment and regulation of other chemical stressors to derive benchmarks. On the basis of consultation with many relevant experts, PROTECT has derived a benchmark screening dose rate, using data on largely reproductive effects to derive species sensitivity distributions, of 10 μGy h-1 which can be used to identify situations which are below regulatory concern with a high degree of confidence.

  3. Study of the uncertainty in estimation of the exposure of non-human biota to ionising radiation

    International Nuclear Information System (INIS)

    Uncertainty in estimations of the exposure of non-human biota to ionising radiation may arise from a number of sources including values of the model parameters, empirical data, measurement errors and biases in the sampling. The significance of the overall uncertainty of an exposure assessment will depend on how the estimated dose compares with reference doses used for risk characterisation. In this paper, we present the results of a study of the uncertainty in estimation of the exposure of non-human biota using some of the models and parameters recommended in the FASSET methodology. The study was carried out for semi-natural terrestrial, agricultural and marine ecosystems, and for four radionuclides (137Cs, 239Pu, 129I and 237Np). The parameters of the radionuclide transfer models showed the highest sensitivity and contributed the most to the uncertainty in the predictions of doses to biota. The most important ones were related to the bioavailability and mobility of radionuclides in the environment, for example soil-to-plant transfer factors, the bioaccumulation factors for marine biota and the gut uptake fraction for terrestrial mammals. In contrast, the dose conversion coefficients showed low sensitivity and contributed little to the overall uncertainty. Radiobiological effectiveness contributed to the overall uncertainty of the dose estimations for alpha emitters although to a lesser degree than a number of transfer model parameters

  4. Possible health effects from terrestrial trunked radio (TETRA). Report on an Advisory Group on Non-ionising Radiation

    International Nuclear Information System (INIS)

    This report by the National Radiological Protection Board's Advisory Group on Non-ionising Radiation gives advice on possible health effects of Terrestrial Trunked Radio (TETRA). It has been prepared, at the request of Government, as a consequence of a recommendation by the Independent Expert Group on Mobile Phones (IEGMP) in May 2000 that 'as a precautionary measure, amplitude modulation around 16 Hz should be avoided, if possible, in future developments in signal coding'. The IEGMP recommendation was made because of the results of a number of studies on the effects of radiofrequency (RF) fields on the rate of loss of radiolabelled calcium from brain and other tissues. These studies, most of which were carried out in the late 1970s and early 1980s on isolated tissues, had suggested that when the RF signal was modulated at around 16 Hz the rate of calcium efflux was increased. IEGMP concluded that although no obvious health risk was suggested, as a precautionary measure, amplitude modulation around 16 Hz should be avoided, if possible

  5. Combined effects, ionizing radiation plus other agents

    International Nuclear Information System (INIS)

    It is clear from cell studies, and confirmed in a general way by animal sudies, that radiation produces effects that are interactive with those due to other physical agents, chemicals of various types, and viruses. Our understanding is limited, however, in respect to the mechanisms of action in cells and, accordingly, even less penetrating in respect to our comprehension of effects in animals. Thus, the conclusion follows at this time, that we are unable to predict responses in humans due to combined action because of our incomplete understanding of individual and combined responses of radiation and other agents in experimental systems. The study of possible public health hazards due to the combined effects of radiation plus other agents is one that should be coverged upon simultaneously by the laboratory investigator and the epidemiologist-public health specialist. What is clear is the likelihood that agents biologically active in their own right may interact. Indeed, an important and significant guiding principle can be extracted from current knowledge. Relative to induced cellular changes, agents that register lesions in the genetic substance of a cell are likely to produce interactive effects. Such effects may become expressed in individual cells, in tissues, or in whole organisms

  6. Orthopaedic surgeries - assessment of ionising radiations exposure in health care workers

    International Nuclear Information System (INIS)

    Full text of publication follows: 1. Objectives: The health care workers are exposed to ionizing radiations during their activities. In the operating rooms, the ionizing radiations are used in orthopaedic surgery and the dose depends on some factors, like the characteristics of the equipment. This study aims to: Estimate the occupational dose of ionizing radiations exposure of the orthopaedic doctors and nurses during the orthopaedic surgeries, in a Portuguese operating room; Sensitize the health care workers to use the individual dosimeter and to adopt radiation preventive measures. 2. Population and methods The study was conducted on nine Orthopaedic doctors and two nurses of an operating room of a hospital in Lisbon neighborhoods. We made a risk evaluating concerning: the radiations dose in different points, corresponding to gonads, hands and crystalline lens levels of all the professionals, during the surgeries; the average period of radiation in the orthopaedic surgeries; the number of annual orthopaedic surgeries, looking for that in the surgeries registers, to estimate the annual ionizing radiations dose of each orthopaedic doctor and nurse. 3. Results The annual doses estimated at different levels for orthopaedic doctors were the following: gonads: between 20,63 and 68,75 mGy; hands: 4,95 16,50 mGy; crystalline lens: 8,25 27,50 mGy). For the orthopaedic nurses: gonads: 130,63 151,25 mGy; hands: 31,35 36,30 mGy; crystalline lens 52,25 60,25 mGy. 4. Conclusions Although the location and positions of health care workers are not the same during the different surgeries and the equipment has an automatic control of the X ray emission, the annual ionizing radiations dose exposure for health care workers is an important one. The risk rating justifies the use of individual dosimeters for better individual dose assessment as part of an ionizing radiations prevention program. As a matter of fact preventive measures begin with a good quantitative risk assessment of

  7. Orthopaedic surgeries - assessment of ionising radiations exposure in health care workers

    Energy Technology Data Exchange (ETDEWEB)

    Leite, E.S.; Uva, A.S. [Lisbon Univ., National School of Public Health/New (Portugal)

    2006-07-01

    Full text of publication follows: 1. Objectives: The health care workers are exposed to ionizing radiations during their activities. In the operating rooms, the ionizing radiations are used in orthopaedic surgery and the dose depends on some factors, like the characteristics of the equipment. This study aims to: Estimate the occupational dose of ionizing radiations exposure of the orthopaedic doctors and nurses during the orthopaedic surgeries, in a Portuguese operating room; Sensitize the health care workers to use the individual dosimeter and to adopt radiation preventive measures. 2. Population and methods The study was conducted on nine Orthopaedic doctors and two nurses of an operating room of a hospital in Lisbon neighborhoods. We made a risk evaluating concerning: the radiations dose in different points, corresponding to gonads, hands and crystalline lens levels of all the professionals, during the surgeries; the average period of radiation in the orthopaedic surgeries; the number of annual orthopaedic surgeries, looking for that in the surgeries registers, to estimate the annual ionizing radiations dose of each orthopaedic doctor and nurse. 3. Results The annual doses estimated at different levels for orthopaedic doctors were the following: gonads: between 20,63 and 68,75 mGy; hands: 4,95 16,50 mGy; crystalline lens: 8,25 27,50 mGy). For the orthopaedic nurses: gonads: 130,63 151,25 mGy; hands: 31,35 36,30 mGy; crystalline lens 52,25 60,25 mGy. 4. Conclusions Although the location and positions of health care workers are not the same during the different surgeries and the equipment has an automatic control of the X ray emission, the annual ionizing radiations dose exposure for health care workers is an important one. The risk rating justifies the use of individual dosimeters for better individual dose assessment as part of an ionizing radiations prevention program. As a matter of fact preventive measures begin with a good quantitative risk assessment of

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

    International Nuclear Information System (INIS)

    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)

  9. Estimation of annual occupational effective doses from external ionising radiation at medical institutions in Kenya

    Directory of Open Access Journals (Sweden)

    Geoffrey K Korir

    2011-12-01

    Full Text Available This study details the distribution and trends of doses from occupational radiation exposure among radiation workers from participating medical institutions in Kenya, where monthly dose measurements were collected for a period of one year (January to December 2007 using thermoluminescent dosimeters. A total of 367 medical radiation workers were monitored, comprising 27% radiologists, 2% oncologists, 4% dentists, 5% physicists, 45% technologists, 4% nurses, 3% film processor technicians, 4% auxiliary staff, and 5% radiology office staff. The average annual effective dose for all subjects ranged from 1.19 to 2.52 mSv. Among these workers, technologists received the largest annual effective dose. The study forms the initiation stage of wider, comprehensive and more frequent monitoring of occupational radiation exposures and long-term investigations into its accumulation patterns, which could form the basis of future records on the detrimental effects of radiation, characteristic of workers in the medical sector, and other co-factors in a developing country such as Kenya.

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

    International Nuclear Information System (INIS)

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

  11. Risks of low dose ionising radiation exposures Riesgos derivados de la exposición a dosis bajas de radiación ionizante

    Directory of Open Access Journals (Sweden)

    Almudena Real Gallego

    2010-12-01

    Full Text Available Although ionising radiation has been shown to have several beneficial applications for humans, it can also produce detrimental effects in humans and the environment. To adequately protect man and environment from the potential harmful effects of ionising radiation, is essential to know in detail the biological effects produced by it, its characteristics and the various factors that influence these effects. That is the objective of this article, describe the current status of knowledge about biological effects induced by ionising radiation, with special emphasis on those effects occurring after low dose exposures.La radiación ionizante ha mostrado tener diversas aplicaciones beneficiosas para el hombre, pero también puede dañar la salud de las personas y el medio ambiente. Para proteger adecuadamente al hombre de los posibles efectos nocivos de la radiación ionizante es imprescindible conocer en detalle los efectos biológicos producidos por esta, sus características y los distintos factores que influyen en dichos efectos. Ese es el objetivo de este artículo: describir el estado actual del conocimiento sobre los efectos biológicos que puede producir la radiación ionizante, con especial énfasis en aquellos efectos que se producen tras la exposición a dosis bajas.

  12. Risk of stillbirth in offspring of men exposed to ionising radiation

    International Nuclear Information System (INIS)

    Radiation genetic risk models are employed to predict the frequency of radiation-related stillbirths to partners of occupationally exposed male workers, using the incidence data recently reported by Parker et al from an epidemiological study of Cumbrian births. Expanding on previously developed conservative risk estimates suggests that, of the 130 observed stillbirths to partners of male radiation workers, 0.3 cases would be attributable to paternal preconceptional irradiation, in contrast to the 17.5 (95% confidence interval: 3.1 to 31.9) cases predicted by Parker et al from their preferred dose-response model. The incompatibility of the results reported by Parker et al with those from other investigations, both epidemiological and experimental, and the inability of the study to consider a number of factors which might affect stillbirth rates, particularly those relating to the mother, make it difficult to accept that paternal irradiation received occupationally could have contributed to a detectable increase in stillbirths. (author)

  13. Delayed behavioral dysfunctions following exposure to ionising radiation: role of neurogenesis

    International Nuclear Information System (INIS)

    Being a terminally differentiated organ, the brain has been considered to be a radioresistant one. Traditionally, delayed radiation-induced CNS damage was hypothesized as chiefly attributable to impaired vascular endothelial system and neuroinflammatory glial cell populations. In the recent decades, preclinical studies have focused on the hippocampal dentate gyrus, one of two discrete sites of the brain where adult neurogenesis takes place. Neurogenesis, in such area of the brain takes place throughout the adulthood and makes the brain highly vulnerable to the radiation. Recent investigations, including our own reports indicated that radiation ablates hippocampal neurogenesis, alters neuronal function, and induces neuroinflammation. Since the hippocampus is involved in learning and memory, behavioral adaptation and HPA axis regulation, damage by radiation leads to severe behavioral and cognitive dysfunctions. The present study aimed at evaluating the delayed effects of gamma-irradiation on the cognitive and affective functions, which were further corroborated to changes in neurogenesis. C57BL/6J mice were exposed to whole body irradiation as well as cranial irradiation by gamma-rays at different sub-lethal doses. The behavioral tests, consisting spontaneous motor activity, open field test, novel object recognition test, forced swim test and Morris water maze were performed at 1 month and 5 months post-exposure. Neurogenic potential was evaluated using flow-cytometry (FC) and immuno-histo-chemistry (IHC). The results indicated the significant changes in the affective and cognitive functions at delayed time points of radiation exposure. Profound alteration in the anxiety and depressive phenotype was observed following irradiation. Additionally, both long term and short term memory functions were disrupted, which were attributable to changes in the neurogenic potential as reported in the terms of BrdU positive cells using FC and IHC. Present investigation clearly

  14. Intercomparisons as an important element of quality assurance in metrology of ionising radiation

    Directory of Open Access Journals (Sweden)

    Živanović Miloš Z.

    2015-01-01

    Full Text Available Intercomparisons are important activities performed to ensure that the services provided by calibration laboratories to end-users follow internationally accepted standards. Ionizing radiation dosimetry intercomparisons are usually of two types - postal thermoluminescent dosimeter intercomparisons and ionization chamber calibration intercomparisons. In this paper, both types of intercomparisons are analysed together with the results of seven years of participation in such intercomparisons. Several discrepancies were discovered as a result of intercomparisons analysis and the resolution of the discrepancies was discussed. [Projekat Ministarstva nauke Republike Srbije, br. III43009: New Technologies for Monitoring and Protection of Environment from Harmful Chemical Substances and Radiation Impact

  15. Process for irradiating large units to be irradiated with ionising radiation

    International Nuclear Information System (INIS)

    The invention concerns a process for irradiating medicinal one-way articles and foodstuffs with gamma rays or X-rays to kill micro-organisms and harmful insects. The purpose of the invention is to improve the homogeneousness of dose and the use of the radiation. This problem is solved by the material to be irradiated being situated in a transport unit, so that there is a region of lower density at the centre then at the peripheral areas. The transport unit must be irradiated from at least two sides by a source of radiation. (orig.)

  16. Pre-Service Teachers' Subject Knowledge of and Attitudes about Radioactivity and Ionising Radiation

    Science.gov (United States)

    Colclough, Nicholas Denys; Lock, Roger; Soares, Allan

    2011-01-01

    This study focussed on secondary school (11-18 years) pre-service teachers' (n = 73) knowledge of and attitudes towards risks associated with alpha, beta, and gamma radiations. A multi-method approach was used with physics, chemistry, biology, and history graduates undertaking the one-year initial teacher training, Post Graduate Certificate in…

  17. Calibration and evaluation of the quality assurance during 1996 at the National Laboratory for ionising radiation

    International Nuclear Information System (INIS)

    The Swedish Radiation Protection Institute is the National Laboratory for the dosimetric quantities kerma, absorbed dose and dose equivalent. The activity is based on established calibration procedures and a QA program for the used standards. This report gives a brief summary of the calibrations performed during 1996 and a more detailed description and analysis of the QA this year. 10 figs, 9 tabs

  18. Examination, characterisation and analysis techniques for the knowledge and the conservation / restoration of cultural heritage - importance of ionising radiation techniques

    International Nuclear Information System (INIS)

    For the examination, characterisation and analysis of cultural heritage artefacts or art objects and their component materials, the conservation scientist needs a palette of non destructive and non invasive techniques, in order to improve our knowledge concerning their elaboration, their evolution and/or degradation during time, and to give rational basis for their restoration and conservation. A general survey and illustrations showing the usefulness of these techniques will be presented. Among these methods, many are based on the use of ionising radiation. 1. Radiography (using X-rays, gamma rays, beta particles, secondary electrons, neutrons), electron emission radiography, tomodensimetry, 2. Scanning electron microscope associated with X-ray spectrometry, 3. X-ray diffraction, 4. Synchrotron radiation characterisation, 5. X-ray fluorescence analysis, 6. Activation analysis, 7. Ion beam analysis (PIXE, PIGE, RBS, secondary X-ray fluorescence), 8. Thermoluminescence dating, 9. Carbon-14 dating. These methods are used alone or in connection with other analytical methods. Any kind of materials can be encountered, for instance: i. stones, gems, ceramics, terracotta, enamels, glasses, i i. wood, paper, textile, bone, ivory, i i i. metals, jewellery, i v. paint layers, canvas and wooden backings, pigments, dyers, oils, binding media, varnishes, glues. Some examples will be taken, among recent work done at the Centre of Research and Restoration of the Museums of France (C2RMF), from various geographical origins, various ages and different art disciplines. This will illustrate the kind of assistance that science and technology can provide to a better knowledge of mankind's cultural heritage and also to the establishment of rational basis for its better conservation for the future generations. (Author)

  19. The FASSET Framework for assessment of environmental impact of ionising radiation in European ecosystems-an overview

    International Nuclear Information System (INIS)

    The FASSET project was launched in November 2000 under the EC 5th Framework Programme to develop a framework for the assessment of environmental impact of ionising radiation in European ecosystems. It involved 15 organisations in seven European countries and delivered its final report in spring 2004. The project set out to organise radioecological and radiobiological data into a logical structure that would facilitate the assessment of likely effects on non-human biota resulting from known or postulated depositions of radionuclides in the environment. The project included an overview of 20 pathway-based environmental assessment systems targeted at radioactive substances, or at hazardous substances in general. The resulting framework includes the following fundamental elements: source characterisation; description of seven major European ecosystems; selection of a number of reference organisms on the basis of prior ecosystem and exposure analysis; environmental transfer analysis; dosimetric considerations; effects analysis; and general guidance on interpretation including consideration of uncertainties. The project has used existing information supplemented with development in some areas, e.g. Monte Carlo calculations to derive dose conversion coefficients, model development, and the building of an effects database (FRED, the FASSET Radiation Effects Database). On the basis of experience from FASSET and other recent programmes, it can be concluded that (i) there is substantial agreement in terms of conceptual approaches between different frameworks currently in use or proposed, (ii) differences in technical approaches can be largely attributed to differences in ecosystems of concern or in national regulatory requirements, (iii) sufficient knowledge is available to scientifically justify assessments following the Framework structure, but (iv) significant data gaps exist for environmental transfer of key nuclides as well as for effects data for key wildlife groups at

  20. Uncertainties in estimating health risks associated with exposure to ionising radiation

    International Nuclear Information System (INIS)

    The information for the present discussion on the uncertainties associated with estimation of radiation risks and probability of disease causation was assembled for the recently published NCRP Report No. 171 on this topic. This memorandum provides a timely overview of the topic, given that quantitative uncertainty analysis is the state of the art in health risk assessment and given its potential importance to developments in radiation protection. Over the past decade the increasing volume of epidemiology data and the supporting radiobiology findings have aided in the reduction of uncertainty in the risk estimates derived. However, it is equally apparent that there remain significant uncertainties related to dose assessment, low dose and low dose-rate extrapolation approaches (e.g. the selection of an appropriate dose and dose-rate effectiveness factor), the biological effectiveness where considerations of the health effects of high-LET and lower-energy low-LET radiations are required and the transfer of risks from a population for which health effects data are available to one for which such data are not available. The impact of radiation on human health has focused in recent years on cancer, although there has been a decided increase in the data for noncancer effects together with more reliable estimates of the risk following radiation exposure, even at relatively low doses (notably for cataracts and cardiovascular disease). New approaches for the estimation of hereditary risk have been developed with the use of human data whenever feasible, although the current estimates of heritable radiation effects still are based on mouse data because of an absence of effects in human studies. Uncertainties associated with estimation of these different types of health effects are discussed in a qualitative and semi-quantitative manner as appropriate. The way forward would seem to require additional epidemiological studies, especially studies of low dose and low dose

  1. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study

    Energy Technology Data Exchange (ETDEWEB)

    Geisel, Dominik; Zimmermann, Elke; Rief, Matthias; Greupner, Johannes; Hamm, Bernd [Charite Medical School, Department of Radiology, Berlin (Germany); Laule, Michael; Knebel, Fabian [Charite Medical School, Department of Cardiology, Berlin (Germany); Dewey, Marc [Charite Medical School, Department of Radiology, Berlin (Germany); Charite, Institut fuer Radiologie, Berlin (Germany)

    2012-08-15

    To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. On average there were 0.12 {+-} 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 {+-} 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. (orig.)

  2. DNA double-strand breaks as potential indicators for the biological effects of ionising radiation exposure from cardiac CT and conventional coronary angiography: a randomised, controlled study

    International Nuclear Information System (INIS)

    To prospectively compare induced DNA double-strand breaks by cardiac computed tomography (CT) and conventional coronary angiography (CCA). 56 patients with suspected coronary artery disease were randomised to undergo either CCA or cardiac CT. DNA double-strand breaks were assessed in fluorescence microscopy of blood lymphocytes as indicators of the biological effects of radiation exposure. Radiation doses were estimated using dose-length product (DLP) and dose-area product (DAP) with conversion factors for CT and CCA, respectively. On average there were 0.12 ± 0.06 induced double-strand breaks per lymphocyte for CT and 0.29 ± 0.18 for diagnostic CCA (P < 0.001). This relative biological effect of ionising radiation from CCA was 1.9 times higher (P < 0.001) than the effective dose estimated by conversion factors would have suggested. The correlation between the biological effects and the estimated radiation doses was excellent for CT (r = 0.951, P < 0.001) and moderate to good for CCA (r = 0.862, P < 0.001). One day after radiation, a complete repair of double-strand breaks to background levels was found in both groups. Conversion factors may underestimate the relative biological effects of ionising radiation from CCA. DNA double-strand break assessment may provide a strategy for individualised assessments of radiation. (orig.)

  3. Occupational exposure to external ionising radiation: Personnel monitoring and dose evaluation at Cernavoda NPP

    International Nuclear Information System (INIS)

    Cernavoda NPP has two CANDU 600 reactors in commercial operation. For a CANDU reactor the major contributor (95%) to the external dose is gamma radiation. Individual dose monitoring is provided by an accredited dosimetric service, approved by the Romanian regulatory body (CNCAN) at CNE Cernavoda. For all the persons entering radiological controlled areas Health Physics Department provides individual dosimetric surveillance. When entering / working in areas where approved dose rates could be exceeded, beside TLD, an electronic direct reading, a personal alarm dosimeter (PAD) is used. When entering / working in areas with significant neutron dose rates an integrating portable neutron monitor is used. The main purpose of design and implementation of an Individual Dosimetry Program is to measure, assign and record all the significant radiation doses (Hp(10), Hp(0.07) and E50) received by an individual during activities performed at CNE Cernavoda NPP and ensure that all the exposure are kept under ALARA prescriptions. (authors)

  4. Inter-comparison of safety culture within selected practices in Ghana utilising ionising radiation

    International Nuclear Information System (INIS)

    The safety culture of selected practices and facilities in Ghana utilising radiation sources or radiation emitting devices has been assessed using a performance indicator, which provided status information on management and operating staff commitment to safety. The questionnaire was based on the following broad areas: general safety considerations, safety policy at the facility level, safety practices at the facility level, definition of responsibility, staff training, safety of the physical structure of the facility and the emergency plans. The analysis showed that the percentage levels of commitment to safety for the respective practices are as follows: conventional radiography, 23.3-90.0%; research reactor, 73.3 %; gamma irradiation facility, 53.3%; radiotherapy, 76.7%; X-ray scanner, 80.0%; gamma scanner, 76.7%; industrial radiography 86.7% and nuclear density practice, 78%. None of the practices or facilities was able to satisfy all the requirements that will ensure a 100% level of safety culture. (authors)

  5. Extension of the shelf life of meat by means of ionising radiation

    International Nuclear Information System (INIS)

    Fresh meat, especially in minced form, has an exceptionally limited shelf life. Radurisation to a 3 kGy dose lengthened the shelf life of vacuum-packed mincemeat by some weeks (compared with a few days for control samples). Spoilage bacteria like the pseudomonads and other Gram-negative rods were completely eliminated by a 3 kGy dose. Attention was also given to combination treatments. Radiation in combination with lactic acid additions had a synergistic preservation effect, resulting in an extended shelf life. Gram-positive organisms like the lactic acid bacteria, and to a lesser extent Brochothrix thermosphacta as well as yeasts, were the most important surviving organisms in radurised meat. Lactobacilli, especially, were present in large numbers in radurised meat at the end of the storage period. Potential pathogens and food-poisoning bacteria like Salmonella typhimurium and some Staphylococcus spp. which are found in the meat, were killed by radurising radiation doses. Radurisation of high-grade, vacuum-packed meat cuts by radiation doses of 2 kGy, resulted in a doubling of the shelf life (stored at 4 degrees Celsius). With the exception of taste and aroma, organoleptic evaluations showed that radurised mincemeat and meat cuts were better than the unirradiated product. Radiation treatment at temperatures of 0 degrees Celsius to 2 degrees Celsius eliminated the problem of taste and aroma. Identification of representative isolates from radurised and control (unirradiated) mincemeat samples confirmed the results obtained with the aid of selective media. The examinations showed that lactobacilli are the most important group of bacteria in radurised meat, while the yeasts also contributed a prominent portion of the total microbe population. The possibilities of applying the process, and aspects which justify further investigation are discussed

  6. S.I. No 249 of 1972, Factories Ionising Radiations (Unsealed Radioactive Substances) Regulations, 1972

    International Nuclear Information System (INIS)

    The Regulations which entered into force on 1 December 1972 apply to factories in which a process involving the use of unsealed radioactive substances is carried on and where the total activity of the unsealed radioactive substances exceeds specified levels, or where there are objects contaminated in excess of certain levels. The Schedules specify the maximum radiation doses and the maximum permissible levels of contamination and provide for a classification of radionuclides

  7. Calibrations and evaluation of the quality assurance during 1999 at the National Laboratory for ionising radiation

    International Nuclear Information System (INIS)

    The Swedish Radiation Protection Institute is the National Laboratory for the dosimetric quantities kerma, absorbed dose and dose equivalent. The activity is based on established calibration procedures and a quality assurance program for the used standards. This report gives a brief summary of the calibrations performed during 1999 and a more detailed description and analysis of the quality assurance during this year. The report makes it easier to draw conclusions about the long-term stability and possible malfunctions

  8. Diagnostic medical exposures: advice on exposure to ionising radiation during pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-01-01

    The NRPB offers advice on exposure to ionizing radiation during pregnancy, based on data published since 1985. In providing this advice the Board has considered risks to the developing embryo and fetus of death, malformation, mental impairment, cancer (solid tumours and leukaemias) and genetic damage from irradiation after the first missed menstrual period. The possible risks from irradiation of the early (up to 3-4 weeks) conceptus and from gonodal irradiation of patients is also covered in the present advice. (Author).

  9. About particular use of ionizing radiations; Des usages particuliers des rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-02-01

    Different uses of ionizing radiations are reviewed: tracers techniques, nuclear gauges, dating by carbon 14, silica doping, use of gamma irradiation for the density measurement in civil engineering, use of a electron capture detector to study by gas chromatography chlorinated contaminants in environment, neutron activation as environmental gauge, analysis of lead in paint and pollutants in ground and dusts, help for work of art valuation by x spectrometry. (N.C.)

  10. Late effects of ionising radiation on the central nervous system of the rat

    International Nuclear Information System (INIS)

    This thesis investigated the role of neuroglial cells in the pathogenesis of delayed radionecrosis of the rat central nervous system (CNS) for up to one year after irradiation. The observed radiation induced changes in the cell kinetics of the subependymal plate of the brain were considered to be important in the development of white matter necrosis. White matter necrosis was apparent in the dorsal, ventral and lateral columns of the cervical cord but in the lumbar cord necrosis was only observed in the nerve bundles of the nerve roots. The glial cell population of the cervical cord was not static and a loss of oligodendrocytes appeared to be important in the development of white matter necrosis. Schwann cells also appeared to be involved in the development of nerve root necrosis of the lumbar cord. It is concluded that a gradual loss of radiation damaged, slowly turning-over supporting cells is the mechanism resulting in the development of late radiation necrosis in the mammalian CNS. The applications of these findings are considered. (UK)

  11. Factors Affecting the Medical Management and Care of Persons Accidentally Overexposed to Ionising Radiations

    International Nuclear Information System (INIS)

    All establishments where acute external radiation overexposure or significant intake of radioactive materials may occur have to make plans to deal with such situations. This paper describes the various stages in such plans and covers selection, early care and, where necessary, transfer of exposed persons for more specialised care. The factors influencing decisions on these matters are discussed, and the necessary degrees of urgency and precision at various stages of the process are reviewed. All emergency schemes have the objective of guarding against deterioration in the condition of the patient and of preparing him for further definitive treatment. In this respect, the approach to cases of internal contamination is different from that applicable to extemal radiation cases. These differences are reviewed and an outline emergency drill is described for each category of incident. Occupational radiation incidents can be considered as a specialised aspect of occupational health but the planning attention devoted to them has been more detailed than that thought appropriate in other fields of industrial hygiene and safety. The need for a clear distinction in the approach to procedures carried out for the benefit of the patient and those carried out for radiological reasons or research purposes is discussed. (author)

  12. Follow-up of children exposed to ionising radiation from cardiac catheterisation: the Coccinelle study

    International Nuclear Information System (INIS)

    Cardiac catheterisation has become an essential tool in the diagnosis and treatment of children with a wide variety of congenital and acquired forms of cardiovascular disease. Despite the clear clinical benefit to the patient, radiation exposure from paediatric cardiac catheterisation procedures (CCPs) may be substantial. Given children's greater sensitivity to radiation and the longer life span during which radiation health effects can develop, an epidemiological cohort study, named Coccinelle or 'Ladybird' (French acronym for 'Cohorte sur le risque de cancer apres cardiologie interventionnelle pediatrique'), is carried out in France to evaluate the risks of leukaemia and solid cancers in this population. A total number of 8000 included children are expected. Individual CCP-related doses will be assessed for each child included in the cohort. For each CCP performed, dosimetric parameters (dose-area product, fluoroscopy time and total number of cine frames) are retrieved retrospectively. Organ doses, especially to the lung, the oesophagus and the thyroid, are calculated with PCXMC software. The cohort will be followed up through linkage with French paediatric cancer registries. (authors)

  13. Development of a Framework for ASSessing the Environmental impacT of ionising radiation on European ecosystems - FASSET

    International Nuclear Information System (INIS)

    A total of 15 organisations (including regulators, research institutes and industry) in seven European countries (Finland, France, Germany, Norway, Spain, Sweden and UK) are collaborating on creating a Framework for ASSessment of Environmental impacT (FASSET) of ionising radiation. The project aims at developing approaches and tools for assessing impact on biota and ecosystems, and to support efforts to protect the environment from harmful effects of radiation. The project is supported by the European Union through the EC 5th Framework Programme, and is due to end in October 2003. The Project is divided into four work packages. In WP2, seven European ecosystems are considered in the assessments; three aquatic (marine, brackish, freshwater) and four terrestrial (seminatural ecosystems including pasture, agricultural ecosystems, wetlands and forests). A list of candidate generic reference organisms has been drawn up on the basis of expert judgement of exposure situations in the selected ecosystems. These organisms are considered references or 'surrogates' for existing biota in the natural habitat. They serve as starting points for development of dosimetric models, being developed in WP 1, and for pooling available information on ecological relevance and biological effects. Further analysis of the candidate reference organisms is performed to justify their choice and assess their applicability in different situations, taking into account modelling of radionuclide transfer, estimates of internal and external dose rates, ecological significance and biological effects. WP3 considers general 'umbrella' effects that, when manifested in an individual, may have an impact at population level or at higher levels of the organisational hierarchy. The four categories are: morbidity (fitness or well-being), mortality (death directly attributable to radiation), reproductive success (changed number of offspring) and scorable cytogenetic effects (molecular actions, aberrations, etc

  14. Cytogenetic methods for bio-dosimetry and risk individualisation after exposure to ionising radiation

    International Nuclear Information System (INIS)

    Measurement of dicentric chromosomes in human lymphocytes has been applied to assess dose received by potentially overexposed people and estimate risk for health effects. Since the dicentrics in exposed people decrease with time, the introduction of fluorescent in situ hybridisation enables to measure stable translocations for bio-dosimetry and address old or long-term exposures. In addition, premature chromosome condensation, which enables analysis in interphase, offers several advantages for bio-dosimetry. However, dose and risk estimates derived using cytogenetics and adequate calibration curves are based on the assumption that all individuals respond equally to radiation. Since increased radiosensitivity has been associated with cancer proneness, there is particular interest for risk assessment at the individual level. Towards this end, the efficiency of dynamics that govern DNA repair and apoptosis, as well as the conserved cellular processes that have evolved to facilitate DNA damage recognition using signal transduction pathways to activate cell cycle arrest and preserve genomic integrity, are being investigated. Recent work in cancer cytogenetics and on the modulation of radiation effects at the chromosome level using changes in gene expression associated with proteins or factors such as caffeine or amifostine treatment during G2 to M-phase transition, reconfirmed the importance of G2 checkpoint in determining radiosensitivity and of the cdk1/cyclin-B activity in the conversion of DNA damage into chromatid breaks. G2-chromosomal radiosensitivity may offer, therefore, a basis for the identification or testing of key genetic targets for modulation of radiation effects and the establishment of a screening method to detect intrinsic radiosensitivity. (authors)

  15. Nuclear law: protection against ionizing radiations; Droit nucleaire: protection contre les rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-15

    The object of this work is since its first edition in 1983 under the title 'Collection of nuclear activities legislation and regulation ' to realize an ordered collection of texts constituting the juridical and institutional frame of nuclear activities, gathering the legislative, regulatory and technical texts; the international, European and national texts. Aiming to include the whole of the atom applications, this collection tackles various themes, in ten chapters. The volume number three is constituted by the following chapter: Protection against ionizing radiations. (N.C.)

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

    International Nuclear Information System (INIS)

    Purpose: This paper gives an overview of the methods that are used to calculate dose and risk from exposure to ionizing radiation as a support to other papers in this special issue. Background: The optimization of radiation dose is a legal requirement in medical exposures. This review paper aims to provide the reader with knowledge of dose by providing definitions and concepts of absorbed, effective and equivalent dose. Criticisms of the use of effective dose to infer the risk of an exposure to an individual will be discussed and an alternative approach considering the lifetime risks of cancer incidence will be considered. Prior to any dose or risk calculation, data concerning the dose absorbed by the patient needs to be collected. This paper will describe and discuss the main concepts and methods that can be utilised by a researcher in dose assessments. Concepts behind figures generated by imaging equipment such as dose-area-product, computed tomography dose index, dose length product and their use in effective dose calculations will be discussed. Processes, advantages and disadvantages in the simulation of exposures using the Monte Carlo method and direct measurement using digital dosimeters or thermoluminescent dosimeters will be considered. Beyond this special issue, it is proposed that this paper could serve as a teaching or CPD tool for personnel working or studying medical imaging

  17. Deterministic effect of lens at leukergy of patients who received low doses of ionising radiation

    International Nuclear Information System (INIS)

    To explore the possibility to use the lens extract as an in vitro stimulator to conduct a test of stimulated leukergy in liquidators of the accident consequences (LAC) on Chernobyl Nuclear Power Plant (CNPP) with a cataract in the long-term period. The study sample included 72 men-LAC on CNPP, at the age from 42 to 65 y, who have a cataract. The comparison group consisted of 60 men, with a cataract, of the same age, and who were not exposed to radiation. The control group was composed of 60 men, at the age of 42-58 y without lens pathology. Phenomenon of the stimulated leukergy was revealed in persons who had been exposed to radiation in the dose of 18.2±0.58 cGy and was observed in 5.7- 8.05 % (P < 0.001), suggesting a continued high auto-aggression to the lens antigens, and the strength of cell-mediated immunity (authors)

  18. Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

    International Nuclear Information System (INIS)

    Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in 137Cs contamination from 100 to 15500 kBq m-2 and estimated external dose rates ranged from 0.13 to 30.7 μGy h-1. General linear models were used to assess whether abundance of individuals, taxon richness, Berger-Parker dominance and Shannon-Wiener diversity varied across the lakes. Step-wise multiple regressions were used to relate variation in total abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity, taxon richness within major groups of macroinvertebrates and abundance of the more common individual taxa to the measured environmental characteristics (conductivity, pH, total hardness and phosphate; lake area, lake maximum depth and total external dose) of the lakes. No evidence was found in this study that the ecological status of lake communities has been influenced by radioactive contamination from the Chernobyl accident. Indeed, the most contaminated lake, Glubokoye, contained the highest richness of aquatic invertebrates. Taxon richness in the eight study lakes varied from 22 (Svyatskoe no. 7) to 42 (Glubokoye) which spans a range typical for uncontaminated lakes in the region. Since 90Sr is readily-absorbed by Mollusca, estimated dose rates to this group exceeded those for other invertebrate groups in two lakes (Perstok and Glubokoye). However this study found no association between mollusc diversity or abundance of individual snail species and variation between lakes in the external radiation dose. Indeed Glubokoye, the lake most contaminated by 90Sr, had the highest richness of freshwater snails per sample (an average of 8.9 taxa per sample). - Highlights: → We studied the effect of radiation on macroinvertebrates in Chernobyl affected lakes. → Abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity evaluated. → No relationship between

  19. Abundance and diversity of aquatic macroinvertebrate communities in lakes exposed to Chernobyl-derived ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, J.F. [NERC Centre for Ecology and Hydrology, Wallingford, Oxfordshire, OX10 8BB (United Kingdom); Nagorskaya, L.L. [Institute of Zoology NAS Belarus, 27, Academicheskaya st., 220072, Minsk (Belarus); Smith, J.T., E-mail: Jim.Smith@port.ac.uk [School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Bldg, Burnaby Road, Portsmouth PO1 3QL (United Kingdom)

    2011-07-15

    Littoral (lake shore) macroinvertebrate communities were studied in eight natural lakes affected by fallout from the Chernobyl accident. The lakes spanned a range in {sup 137}Cs contamination from 100 to 15500 kBq m{sup -2} and estimated external dose rates ranged from 0.13 to 30.7 {mu}Gy h{sup -1}. General linear models were used to assess whether abundance of individuals, taxon richness, Berger-Parker dominance and Shannon-Wiener diversity varied across the lakes. Step-wise multiple regressions were used to relate variation in total abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity, taxon richness within major groups of macroinvertebrates and abundance of the more common individual taxa to the measured environmental characteristics (conductivity, pH, total hardness and phosphate; lake area, lake maximum depth and total external dose) of the lakes. No evidence was found in this study that the ecological status of lake communities has been influenced by radioactive contamination from the Chernobyl accident. Indeed, the most contaminated lake, Glubokoye, contained the highest richness of aquatic invertebrates. Taxon richness in the eight study lakes varied from 22 (Svyatskoe no. 7) to 42 (Glubokoye) which spans a range typical for uncontaminated lakes in the region. Since {sup 90}Sr is readily-absorbed by Mollusca, estimated dose rates to this group exceeded those for other invertebrate groups in two lakes (Perstok and Glubokoye). However this study found no association between mollusc diversity or abundance of individual snail species and variation between lakes in the external radiation dose. Indeed Glubokoye, the lake most contaminated by {sup 90}Sr, had the highest richness of freshwater snails per sample (an average of 8.9 taxa per sample). - Highlights: > We studied the effect of radiation on macroinvertebrates in Chernobyl affected lakes. > Abundance, taxon richness, Berger-Parker dominance, Shannon-Wiener diversity evaluated. > No

  20. The combined effect of diabetes and ionising radiation on the retinal vasculature of the rat

    International Nuclear Information System (INIS)

    The clinical impression that pre-existing diabetes exacerbates radiation injury to the retinal vasculature was studied in STZ diabetic rats. Half of 2 groups of streptozotocin (STZ)-induced diabetic rats and 1 group of normal animals had their right eyes irradiated with 1000 cGy of 90 KVP x-rays. The prevalence of acellular capillaries in trypsin digests of the retinal vasculature was quantified for each of the 6 groups of animals at 6.5 months post-irradiation. The prevalence of acellular capillaries in both non-irradiated diabetic groups was significantly higher than in controls while the irradiated animals in each of the three main categories showed a statistically significant increase compared to their non-irradiated equivalents. (author)

  1. Pregnancy and exposure to ionizing radiations; Femme enceinte et exposition aux rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Topsoba, T.L. [Ouagadougou-Burkina Faso Univ., Lab. de Biophysique UFR/SDS (Burkina Faso); Tapsoba, T.L.; Cisse, R.; Lougue Sorgho, L.C.; Bamouni, Y.A. [Centre Hospitalier Universitaire Yo, Service de Radiologie et d' Imagerie Medicale (Burkina Faso); Gassama Seck, S. [Faculte de Medecine - UCAD, Dakar (Senegal)

    2006-06-15

    The sensitivity of the embryo and foetus varies during pregnancy. Recent studies confirm that the principal damage is mental retardation. It is generally admitted that the risk is negligible for a dose < 100 milli-sieverts (mSv). A possible termination of pregnancy will be considered for an exposure > 200 mSv.The objective of this work is to provide precise information on the various risks related to the irradiation for the foetus, according to the age of gestation and delivered dose, and the action to be taken in case of accidental irradiation. The medical use of ionizing radiation in pregnant women can only be considered within the framework of precise information. (author)

  2. Protection of the environment from ionising radiation in a regulatory context (protect): proposed numerical benchmark values

    International Nuclear Information System (INIS)

    Criteria are needed to be able to judge the level of risk associated with dose rates estimated for non-human biota. In this paper, European guidance on the derivation of predicted no-effect chemical concentrations has been applied to appropriate radiation sensitivity data. A species sensitivity distribution fitted to the data for all species resulted in a generic predicted no-effect dose rate of 10 μGy h-1. Currently, data are inadequate to derive screening values for separate organism groups. A second, higher, benchmark could aid in decision making by putting results into context on the scale of no effect to a risk of 'serious' effect. The need for, meaning and use of such a value needs to be debated by the wider community. This paper explores potential approaches of deriving scientific input to this debate. The concepts proposed in this paper are broadly consistent with the framework for human protection.

  3. Protection of the environment from ionising radiation in a regulatory context (protect): proposed numerical benchmark values

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Pal, E-mail: pal.andersson@ssm.s [Swedish Radiation Safety Authority, 171 16 Stockholm (Sweden); Garnier-Laplace, Jacqueline [Institut de Radioprotection et de Surete Nucleaire DEI/SECRE, CEN Cadarache, Bt 159, BP 3, 13115 Saint-Paul-lez-Durance (France); Beresford, Nicholas A. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Copplestone, David [Environment Agency, PO Box 12, Richard Fairclough House, Knutsford Road, Warrington, WA4 1HG (United Kingdom); Howard, Brenda J. [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster, LA1 4AP (United Kingdom); Howe, Paul [Centre for Ecology and Hydrology, Monks Wood, Abbots Ripton, Huntingdon, Cambridgeshire, PE28 2LS (United Kingdom); Oughton, Deborah [Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, 1432 Aas (Norway); Whitehouse, Paul [Environment Agency, Red Kite House, West Area Office, Howbery Park, Crowmarsh Gifford, Wallingford, Oxfordshire, OX10 8BD (United Kingdom)

    2009-12-15

    Criteria are needed to be able to judge the level of risk associated with dose rates estimated for non-human biota. In this paper, European guidance on the derivation of predicted no-effect chemical concentrations has been applied to appropriate radiation sensitivity data. A species sensitivity distribution fitted to the data for all species resulted in a generic predicted no-effect dose rate of 10 muGy h{sup -1}. Currently, data are inadequate to derive screening values for separate organism groups. A second, higher, benchmark could aid in decision making by putting results into context on the scale of no effect to a risk of 'serious' effect. The need for, meaning and use of such a value needs to be debated by the wider community. This paper explores potential approaches of deriving scientific input to this debate. The concepts proposed in this paper are broadly consistent with the framework for human protection.

  4. Effects of low doses of ionizing radiation; Effets des faibles doses de rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France)

    2006-07-01

    Several groups of human have been irradiated by accidental or medical exposure, if no gene defect has been associated to these exposures, some radioinduced cancers interesting several organs are observed among persons exposed over 100 to 200 mSv delivered at high dose rate. Numerous steps are now identified between the initial energy deposit in tissue and the aberrations of cell that lead to tumors but the sequence of events and the specific character of some of them are the subject of controversy. The stake of this controversy is the risk assessment. From the hypothesis called linear relationship without threshold is developed an approach that leads to predict cancers at any tiny dose without real scientific foundation. The nature and the intensity of biological effects depend on the quantity of energy absorbed in tissue and the modality of its distribution in space and time. The probability to reach a target (a gene) associated to the cancerating of tissue is directly proportional to the dose without any other threshold than the quantity of energy necessary to the effect, its probability of effect can be a more complex function and depends on the quality of the damage produced as well as the ability of the cell to repair the damage. These two parameters are influenced by the concentration of initial injuries in the target so by the quality of radiation and by the dose rate. The mechanisms of defence explain the low efficiency of radiation as carcinogen and then the linearity of effects in the area of low doses is certainly the least defensible scientific hypothesis for the prediction of the risks. (N.C.)

  5. Radiation Chemistry Studies on Chemotherapeutic Agents

    DEFF Research Database (Denmark)

    Gohn, M.; Getoff, N.; Bjergbakke, Erling

    1977-01-01

    Adrenalin has been studied as a model radiation protective agent by means of pulse radiolysis in aqueous solutions. The rate constants for the reactions of adrenalin with e–aq and OH were determined : k(e–aq+ adr—NH+2)= 7.5 × 108 dm3 mol–1 s–1, k(e–aq+ adr—NH)= 2.5 × 108 dm3 mol–1 s–1, and k(OH +...

  6. The long-term effects of acute exposure to ionising radiation on survival and fertility in Daphnia magna.

    Science.gov (United States)

    Sarapultseva, Elena I; Dubrova, Yuri E

    2016-10-01

    The results of recent studies have provided strong evidence for the transgenerational effects of parental exposure to ionising radiation and chemical mutagens. However, the transgenerational effects of parental exposure on survival and fertility remain poorly understood. To establish whether parental irradiation can affect the survival and fertility of directly exposed organisms and their offspring, crustacean Daphnia magna were given 10, 100, 1000 and 10,000mGy of acute γ-rays. Exposure to 1000 and 10,000mGy significantly compromised the viability of irradiated Daphnia and their first-generation progeny, but did not affect the second-generation progeny. The fertility of F0 and F1Daphnia gradually declined with the dose of parental exposure and significantly decreased at dose of 100mGy and at higher doses. The effects of parental irradiation on the number of broods were only observed among the F0Daphnia exposed to 1000 and 10,000mGy, whereas the brood size was equally affected in the two consecutive generations. In contrast, the F2 total fertility was compromised only among progeny of parents that received the highest dose of 10,000mGy. We propose that the decreased fertility observed among the F2 progeny of parents exposed to 10,000mGy is attributed to transgenerational effects of parental irradiation. Our results also indicate a substantial recovery of the F2 progeny of irradiated F0Daphnia exposed to the lower doses of acute γ-rays. PMID:27288911

  7. Effects of the ionising radiations on the structure and the function of the intestinal epithelial cell

    International Nuclear Information System (INIS)

    The intestinal mucosa is a particularly radio-sensitive tissue and damage may occur following either accidental or therapeutic exposure. the deleterious actions of ionizing radiation are linked to the formation of sometimes overwhelming quantities of reactive oxygen species (R.O.S.). Production of R.O.S. is both direct and indirect from the secondary effects of irradiation. A better comprehension of the underlying mechanisms of injury will lead to more adapted therapeutic approaches to limit the harmful effects of irradiation. The homeostasis of the intestinal epithelium is regulated by three factors: proliferation, apoptosis and differentiation. these three factors were studied using the cell model, HT29, in order to analyze modulations of this balance after irradiation. our results, in agreement with other data, showed the establishment of mitotic delay. This arrest of proliferation was followed by apoptosis to be the major mechanism leading to cell death in this model. thus, for the first time, we have shown that irradiated intestinal epithelial cells preserve their capacity to differentiate. This indicates, although indirectly, that intestinal cells have and preserve an intrinsic capacity restore a functional epithelium. R.O.S. are considered as intermediates between the physical nature of radiations and biological responses. It seems essential to understand anti-oxidant mechanisms used by the cell for defence against the deleterious effects of R.O.S post exposure. This study of several anti-oxidant defence mechanisms of intestinal mucosa, was carried out in vivo in the mouse at different times following abdominal irradiation. We observed an early mitochondrial response in the hours following irradiation revealing this organelle as a particular target. We demonstrated a strong alteration of anti-oxidant capacity as revealed by a decrease in S.O.D.s, catalase and an increase of the G.P.X.s and M.T.s. A part of these modifications appeared to depend on an

  8. Using ionising radiation against terrorism and contrabandage determination of the occurring dose values

    International Nuclear Information System (INIS)

    Full text of publication follows: Presently the combat against terrorism and contrabandage is gaining in importance. This leads to a growing need for human inspections for weapons or chemical substances like drugs or explosives at e.g. airports and federal buildings. Up to now, this has been done mainly by pat search or the use of metal detectors. But the installed metal detection systems can have a high rate of false alerts, caused e.g. by belt buckles, leading to a high rate of time consuming manual follow-up checks. Also, it is not possible to detect chemical substances or modern plastic weapons. Therefore, a lot of efforts have been made to develop reliable technologies for passenger and cargo controls. Up to now, the demands placed on control systems for the use in routine are fulfilled only by X-ray screening systems. X-ray scanners have been used successfully for several years for personnel controls (checks) at diamond mines and prisons or as cargo scanner. So far, however, these systems have not been used frequently for human inspections, e.g. at airports. In general, two aspects must be considered wit h regard to the use of X-ray personnel scanners: the privacy aspect, because the body shape is seen, and the radiation protection aspect. For radiation protection purposes, and to observe the prescribed dose limits, it is extremely important to know the dose a person gets knowingly when passing a personnel scanner or, as a stowaway, a cargo scanner. Within the scope of a research project measurements were performed on different types of personnel and cargo scanners, using the transmission and backscattering method. All scanners investigated work with a high dose rate and use a short irradiation time. Because of this technique, reliable values of the personal and ambient dose equivalent, Hp(10) and H*(10), could be determined only with a specially developed measuring system (presented in a poster at this conference). The scanner systems and dose values

  9. Measurement of occupational doses of ionising radiation to the lens of the eyes of interventional radiologists.

    Science.gov (United States)

    Higgins, Anthony

    2016-03-01

    Currently, there exists no standardised method for monitoring radiation doses to the eye lens. This investigation aimed to determine the optimum method for monitoring the eye doses for interventional radiologists. Three interventional radiologists were issued with a series of dosimeters to wear during their routine work. These dosimeters were worn at defined positions on the body and the absorbed dose to each position was measured. It was confirmed that the dose received to the thyroid collar followed an apparently well-defined relationship to the dose recorded on the forehead, which is representative of the dose to the lens of the eye. It was also confirmed that, as hypothesised, the dose to the left eye was universally greater than to the right, although by varying factors. It was concluded that the use of dosimeters attached to the inside arms of protective eyewear is the optimum solution for eye lens dosimetry. It was also concluded that, when used with a dose conversion factor which corroborates existing literature, dosimeters attached to the outside of a thyroid collar yield sufficiently accurate results for use in routine dosimetry programmes. PMID:26643204

  10. ELF electromagnetic fields and neurodegenerative disease. Report of an Advisory Group on Non-ionising radiation

    International Nuclear Information System (INIS)

    There are continuing concerns about the possible health effects that may arise as a consequence of exposure to electromagnetic fields and radiations (EMFs). In relation to exposures to power frequency (extremely low frequency, ELF) electromagnetic fields, the principal concern has been the possibility that they may be implicated in the development of cancer. In developing its advice for the Board of NRPB on the possible health effects of electromagnetic fields, the Advisory Group has reviewed a number of studies that have examined associations between Alzheimer's disease, motor neuron disease and Parkinson's disease and exposure to electromagnetic fields. These diseases may be classed as neurodegenerative disease as all involve the death of neurons, although their aetiology is different. This report examines first the biological basis of these neurodegenerative diseases, the location of the nerve cells implicated in their development, and the pathological changes that become manifest as they develop. lt then reviews the relevant epidemiological studies. These have examined the possibility of a relationship with exposure to ELF electromagnetic fields, particularly as a consequence of work involving the use of electricity (eg electric power line/cable workers, welders, electricians and dressmakers)

  11. Effect of ionising radiation on shelf life and potency of herbal raw materials

    International Nuclear Information System (INIS)

    Medicinal herbs are involving from fringe to mainstream use with a greater number of people seeking remedies and health approaches free from side effects caused by synthetic chemicals. Unfortunately, the number of reports of people experiencing negative effects, caused by the use of herbal drugs, has also been increasing. There may be various reasons for such problems, poor quality of herbal medicines due to insufficient attention being paid to the quality assurance and control of these products. Plants are associated with their own microflora, in addition to that soil and air act as main inoculum source for causing contamination in crude herbs along with other field practices like harvesting, handling and packing. The study was aimed to determine the type, level of bacterial and fungal load and feasibility of electron beam irradiation to hygenise the commonly used herbal raw materials using electron beam radiation with three different dosages viz., 8 kGy, 12 kGy, 15 kGy. Irradiated and control samples were analysed for microbial load and biochemical compositions. In present study, microbial load was proportionately reduced with increase in dosage compared to non-irradiated samples. Results indicated that non-irradiated samples were highly contaminated with microbial load. E. coli and Staphylococcus spp. were predominant among the bacterial contaminants at varying levels. The fungi enumerated from raw materials includes species of Penicillium, Rhizopus, Mucor and Aspergillus. Minimum variation was recorded in the carbohydrate, protein, phenolic, tannin and ascorbic acid content of the herb samples with irradiation treatment. (author)

  12. Updated estimates of the proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionising radiation

    International Nuclear Information System (INIS)

    The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionising radiation, such as was experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily upon studies of the Japanese A-bomb survivors imply that low-level exposure to ionising radiation, including to ubiquitous natural background radiation, also raises the risk of childhood leukaemia. In a recent paper (Wakeford et al 2009 Leukaemia 23 770-6) we estimated the proportion of childhood leukaemia incidence in Great Britain attributable to natural background radiation to be about 20%. In this paper we employ the two sets of published leukaemia risk models used previously, but use recently published revised estimates of natural background radiation doses received by the red bone marrow of British children to update the previous results. Using the newer dosimetry we calculate that the best estimate of the proportion of cases of childhood leukaemia in Great Britain predicted to be attributable to this source of exposure is 15-20%, although the uncertainty associated with certain stages in the calculation (e.g. the nature of the transfer of risk between populations and the pertinent dose received from naturally occurring alpha-particle-emitting radionuclides) is significant. The slightly lower attributable proportions compared with those previously derived by Wakeford et al (Leukaemia 2009 23 770-6) are largely due to the lower doses (and in particular lower high LET doses) for the first year of life.

  13. Updated estimates of the proportion of childhood leukaemia incidence in Great Britain that may be caused by natural background ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

    Little, Mark P [Department of Epidemiology and Public Health, Imperial College, London W2 1PG (United Kingdom); Wakeford, Richard [Dalton Nuclear Institute, University of Manchester, Pariser Building-G Floor, PO Box 88, Sackville Street, Manchester M60 1QD (United Kingdom); Kendall, Gerald M [Childhood Cancer Research Group, Richards Building, University of Oxford, Old Road Campus, Oxford OX3 7LG (United Kingdom)], E-mail: mark.little@imperial.ac.uk

    2009-12-01

    The aetiology of childhood leukaemia remains generally unknown, although exposure to moderate and high levels of ionising radiation, such as was experienced during the atomic bombings of Japan or from radiotherapy, is an established cause. Risk models based primarily upon studies of the Japanese A-bomb survivors imply that low-level exposure to ionising radiation, including to ubiquitous natural background radiation, also raises the risk of childhood leukaemia. In a recent paper (Wakeford et al 2009 Leukaemia 23 770-6) we estimated the proportion of childhood leukaemia incidence in Great Britain attributable to natural background radiation to be about 20%. In this paper we employ the two sets of published leukaemia risk models used previously, but use recently published revised estimates of natural background radiation doses received by the red bone marrow of British children to update the previous results. Using the newer dosimetry we calculate that the best estimate of the proportion of cases of childhood leukaemia in Great Britain predicted to be attributable to this source of exposure is 15-20%, although the uncertainty associated with certain stages in the calculation (e.g. the nature of the transfer of risk between populations and the pertinent dose received from naturally occurring alpha-particle-emitting radionuclides) is significant. The slightly lower attributable proportions compared with those previously derived by Wakeford et al (Leukaemia 2009 23 770-6) are largely due to the lower doses (and in particular lower high LET doses) for the first year of life.

  14. Effects of chronic exposure to ionising radiation in the Pacific oyster Crassostrea gigas

    International Nuclear Information System (INIS)

    The Cotentin peninsula (Normandy, France) hosts nuclear industry facilities which operate with controlled discharges of radionuclides in the marine environment. Compared to natural radioactivity, the increase by artificial radionuclides is small but constant. As a consequence, marine species are chronically exposed to low additional doses of ionizing radiation (IR). The effects of chronic exposure to radionuclides were investigated in early stages of development of the Japanese oyster Crassostrea gigas. On the basis of literature, mollusks are expected to be particularly resistant to acute IR (UNSCEAR, 1996. Sources and effects of ionizing radiation. Report to the General Assembly, with Scientific Annex. 86 p). Two different chronic exposure conditions consisted in external (137Cs) and internal (241Am) irradiation for two weeks. Biological endpoints were analyzed in parallel at both the integrated (growth) and molecular (target stress gene expression) levels. To identify potential biological targets of IR, oysters were first exposed to very high dose rates and radionuclide activities with the perspective to reduce the levels and to derive dose-response curves. Although the initial exposure levels (137Cs 30 000 μGy.h-1; 241Am 57 000 Bq.L-1) were many orders of magnitude higher than those encountered in the natural environment, no significant change in the measured parameters was observed. This result was surprising because data from the literature showed that exposure of mussel Mytilus edulis to 3H at lower doses rates (10-100 μGy.h-1) induced DNA damage in hemocytes (Jha et al., 2005. Impact of low doses of tritium on the marine mussel, Mytilus edulis: Genotoxic effects and tissue-specific bioconcentration. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 586, 47-57). To understand this apparent discrepancy between those two filtering bivalves, a new experiment was performed to compare the response of oyster exposed to 3H in the same condition

  15. Effects of chronic exposure to ionising radiation in the Pacific oyster Crassostrea gigas

    Energy Technology Data Exchange (ETDEWEB)

    Fievet, B.; Devos, A.; Voiseux, C.; Leconte-Pradines, C. [Institut de Radioprotection et de Surete' Nucleaire (France); Dallas, L.; Jha, A. [University of Plymouth (United Kingdom)

    2014-07-01

    The Cotentin peninsula (Normandy, France) hosts nuclear industry facilities which operate with controlled discharges of radionuclides in the marine environment. Compared to natural radioactivity, the increase by artificial radionuclides is small but constant. As a consequence, marine species are chronically exposed to low additional doses of ionizing radiation (IR). The effects of chronic exposure to radionuclides were investigated in early stages of development of the Japanese oyster Crassostrea gigas. On the basis of literature, mollusks are expected to be particularly resistant to acute IR (UNSCEAR, 1996. Sources and effects of ionizing radiation. Report to the General Assembly, with Scientific Annex. 86 p). Two different chronic exposure conditions consisted in external ({sup 137}Cs) and internal ({sup 241}Am) irradiation for two weeks. Biological endpoints were analyzed in parallel at both the integrated (growth) and molecular (target stress gene expression) levels. To identify potential biological targets of IR, oysters were first exposed to very high dose rates and radionuclide activities with the perspective to reduce the levels and to derive dose-response curves. Although the initial exposure levels ({sup 137}Cs 30 000 μGy.h{sup -1}; {sup 241}Am 57 000 Bq.L{sup -1}) were many orders of magnitude higher than those encountered in the natural environment, no significant change in the measured parameters was observed. This result was surprising because data from the literature showed that exposure of mussel Mytilus edulis to {sup 3}H at lower doses rates (10-100 μGy.h{sup -1}) induced DNA damage in hemocytes (Jha et al., 2005. Impact of low doses of tritium on the marine mussel, Mytilus edulis: Genotoxic effects and tissue-specific bioconcentration. Mutation Research/Genetic Toxicology and Environmental Mutagenesis 586, 47-57). To understand this apparent discrepancy between those two filtering bivalves, a new experiment was performed to compare the response

  16. Carcinogenic risk assessment and management of ionising radiation, asbestos and nickel: a comparative approach

    International Nuclear Information System (INIS)

    The objective of this study is to identify the similarities as well as the differences of risk assessment and management of ionizing radiation, asbestos and nickel in France. The comparison has been performed at three levels of analysis: concepts, regulation and practices. Ionizing radiation (IR) is compared with asbestos as far as occupational exposure is concerned and to nickel and nickel compounds as far as general population exposure is concerned. The three main stages of risk assessment were considered: hazard identification, exposure-risk relationship, exposure assessment. Alternative risk management policies were reviewed. The main results are the following: At the conceptual level, the risk assessment and management frameworks present many similarities: exposure-risk relationships exist, and low dose extrapolation is considered as legitimate. Comparison of protection strategies can be carried out with reference to the 'optimization' principle developed for IR. At the regulatory level, the status of the IR dose limits differs from the status of the exposure limit values set for asbestos and nickel. For IR, compliance with the dose limit cannot be seen as the final objective of protection: the burden is put on the requirement to maintain the doses as low as reasonably achievable, social and economical factors being taken into account (ALARA). In most of the situations, actual exposure to IR in industry appear to be significantly lower than the dose limit. In the case of asbestos and nickel, the exposure limit values are very low and compliance with the limits is indeed a quite ambitious objective. At the practical level, some noticeable differences exist as far as the decision aiding procedures are concerned. A process which may be considered as an ALARA approach is applied, in the case of nickel: seeking for the 'best available technologies', defining and implementing with stakeholdes regional plans for air quality. In the case of asbestos, the predictive

  17. Indian estimates of risk from exposure to ionising radiation- an update

    International Nuclear Information System (INIS)

    The ICRP and various expert committees have obtained estimates of exposure induced stochastic effects on contemporary populations using risk coefficients from the studies of death rates in Japanese atom bomb survivors along with data on characteristic base-line cancer and all-causes mortality of populations. In this paper we present updated Indian base-line cancer and all causes mortality data and apply it for the estimation of radiation exposure attributable risk quantities using risk coefficients of the relative risk model. The base-line cancer data is obtained as an average of six Indian cities and the all-causes mortality data is from the Indian life tables for the period 1986-90. Indian estimates of lifetime probability (R) of exposure attributable fatal cancer and the years of lifetime lost (Y) in case of attributable death are estimated for occupational and public exposure scenarios. Lifetime excess mortality (LEM) from acute exposure of age distributed populations of all-ages and of adult workers are also estimated. It is shown that the Indian values of R and LEM estimated by the relative risk model are about a factor of three lower than the ICRP world average values. The Indian values of R (public) and R (occupational) obtained using 1986-90 life tables are higher than those obtained using the 1981-86 life tables by about 8 % to 4 % respectively. These increases are attributed to increase in Indian life-expectancy-at-birth from 55.5 to 57.9 years and life-expectancy-at-age 18 years from 49.8 years to 50.3 years respectively during the five-year period. There is no significant change in values of LEM estimated with the 1981-85 and 1986-90 life tables. (author)

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

    International Nuclear Information System (INIS)

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

  19. The problem of radiation damage to DNA. Methods for control of antagonism and radio-protective effect in combined action ionising radiation on DNA

    International Nuclear Information System (INIS)

    Combined effects of hard (gamma quantum, neutrons) and soft (VUV) ionising radiations and property of intercellular medium (temperature, viscous friction of DNA) on depolymerisation, repairing and stability of DNA macromolecules are studied. The paper deals with the situation evolved from double breaks in complementary chains of DNA, which are caused by gamma-radiation or neutrons and are non-repairable by the enzyme ligase. It was shown that at a low relative concentration of hydrated electrons (α≤10-9) the pair guanine-thymine interacts attractively when the width of a break is small (L10-20A. When α>10-9 the barrier for a guanine-thymine interaction gets lower and at α≥10-7 the barrier disappears. When the coefficient of viscous friction decreases there are the same results. All other pairs of nucleotides experience only attraction. The above situation creates the possibility of a total self-repairing of all kinds of DNA double breakage. These data testify to the existence of basic (physical) radioresistance of cell genome, defined by the structure of DNA

  20. Radiation induced sterility to control tsetse flies. The effect of ionising radiation and hybridisation on tsetse biology and the use of the sterile insect technique in integrated tsetse control.

    OpenAIRE

    Vreysen, M. J. B.

    1995-01-01

    The induction of dominant lethal mutations by exposing tsetse flies as pupae or adult insects to ionising radiation and the use of hybrid sterility resulting from crosses of closely related tsetse species or subspecies, are potential methods of genetic control of tsetse flies. In this thesis the effects of radiation and hybridisation on the reproductive biology and fitness of several species of tsetse flies has been examined. In addition, aspects of field releases of sterile insects have also...

  1. Risk of cancer from occupational exposure to ionising radiation: retrospective cohort study of workers in France, the United Kingdom, and the United States (INWORKS)

    Science.gov (United States)

    Cardis, Elisabeth; Daniels, Robert D; Gillies, Michael; O’Hagan, Jacqueline A; Hamra, Ghassan B; Haylock, Richard; Laurier, Dominique; Leuraud, Klervi; Moissonnier, Monika; Schubauer-Berigan, Mary K; Thierry-Chef, Isabelle; Kesminiene, Ausrele

    2015-01-01

    Study question Is protracted exposure to low doses of ionising radiation associated with an increased risk of solid cancer? Methods In this cohort study, 308 297 workers in the nuclear industry from France, the United Kingdom, and the United States with detailed monitoring data for external exposure to ionising radiation were linked to death registries. Excess relative rate per Gy of radiation dose for mortality from cancer was estimated. Follow-up encompassed 8.2 million person years. Of 66 632 known deaths by the end of follow-up, 17 957 were due to solid cancers. Study answer and limitations Results suggest a linear increase in the rate of cancer with increasing radiation exposure. The average cumulative colon dose estimated among exposed workers was 20.9 mGy (median 4.1 mGy). The estimated rate of mortality from all cancers excluding leukaemia increased with cumulative dose by 48% per Gy (90% confidence interval 20% to 79%), lagged by 10 years. Similar associations were seen for mortality from all solid cancers (47% (18% to 79%)), and within each country. The estimated association over the dose range of 0-100 mGy was similar in magnitude to that obtained over the entire dose range but less precise. Smoking and occupational asbestos exposure are potential confounders; however, exclusion of deaths from lung cancer and pleural cancer did not affect the estimated association. Despite substantial efforts to characterise the performance of the radiation dosimeters used, the possibility of measurement error remains. What this study adds The study provides a direct estimate of the association between protracted low dose exposure to ionising radiation and solid cancer mortality. Although high dose rate exposures are thought to be more dangerous than low dose rate exposures, the risk per unit of radiation dose for cancer among radiation workers was similar to estimates derived from studies of Japanese atomic bomb survivors. Quantifying the cancer risks associated

  2. Bystander effects and biota: implications of radiation-induced bystander effects for protection of the environment from ionising radiation

    International Nuclear Information System (INIS)

    Bystander effects are now known to be induced by both high and low LET in a variety of cells in culture. They have been proven to occur in vivo in mice following 0.5Gy total body irradiation and in blood from humans being treated for cancer by radiotherapy. Effects have also been detected in fish, crustacea and molluscs. The important questions now are not whether bystander effects occur but why and what implications they have, if any, for radiation protection. Different species and different genetic backgrounds within a species produce different types of bystander effect, different organs also produce different effects. This paper will review the data in this field and will discuss likely implications for protection of man and non-human biota. In particular it will look at the potential long-term outcomes for different organisational levels, from cell to ecosystem, of bystander mechanisms. In view of new concerns about the effects of low level radiation on non-human biota, emphasis will be placed on considering how bystander effects might operate at chronic low doses versus acute accidental low doses. Problems of radiation interaction with chemicals, whether chemicals can also induce 'bystander effects' , and how regulators might handle these situations which occur all the time in real environments, will be presented for discussion. Finally the paper will discuss likely implications of these mechanisms for evolutionary biology

  3. Studies of ionising radiation induced bystander effects in 3D artificial tissue system and applications for radiation protection

    International Nuclear Information System (INIS)

    The universality of the target theory of radiation-induced effects is challenged by observations on non-targeted effects such as bystander effects. Essential features of non-targeted effects are that they do not require direct nuclear exposure by radiation and they are particularly significant at low doses. This new evidence suggests a need for a new paradigm in radiation biology. The new paradigm should cover both the classical (targeted) and the non-targeted effects. The bystander effect cannot be comprehensively explained on the basis of a single cell reaction. It is well known that an organism is composed of different cell types that interact as functional units in a way to maintain normal tissue function. Therefore the radiation response is not simply the sum of cellular responses as assumed in classical radiobiology, predominantly from studies using cell cultures. Experimental models, which maintain tissue-like intercellular cell signalling and 3D structure, are essential for proper understanding of the bystander effect. Our work relates to experimentation with novel 3D artificial human tissue systems available from MatTek Corporation (Boston, USA). Air-liquid interface culture technique is used to grow artificial tissues, which allow to model conditions present in vivo. The Gray Cancer Institute (Northwood, UK) charged particle microbeam was used to irradiate tissue samples in a known pattern with a known number of 3He2+ particles or protons. After irradiation, the tissues models were incubated for 3 days, fixed in 10 % NBF, paraffin embedded and then sliced into 5 μm histological sections located at varying distances from the plane of the irradiated cells. We studied in situ apoptosis and markers of differentiation. Significantly elevated bystander induced apoptosis was observed with 3'-OH DNA end-labelling based technique in 3D artificial tissue systems. Our results also suggested an importance of proliferation and differentiation status for bystander

  4. Nicotinamide and other benzamide analogs as agents for overcoming hypoxic cell radiation resistance in tumours

    International Nuclear Information System (INIS)

    Oxygen deficient hypoxic cells, which are resistant to sparsely ionising radiation, have now been identified in most animal and some human solid tumours and will influence the response of those tumours to radiation treatment. This hypoxia can be either chronic, arising from an oxygen diffusion limitation, or acute, resulting from transient stoppages in microregional blood flow. Extensive experimental studies, especially in the last decade, have shown that nicotinamide and structurally related analogs can effectively sensitize murine tumours to both single and fractionated radiation treatments and that they do so in preference to the effects seen in mouse normal tissues. The earliest studies suggested that this enhancement of radiation damage was the result of an inhibition of the repair mechanisms. However, recent studies in mouse tumours have shown that these drugs prevent transient cessations in blood flow, thus inhibiting the development of acute hypoxia. This novel discovery led to the suggestion that the potential role of these agents as radiosensitizers would be when combined with treatments that overcame chronic hypoxia. The combined nicotinamide with hyperthermia proved that the enhancement of radiation damage by both agents together was greater than that seen with each agent alone. Similar results were later seen for nicotinamide combined with a perfluorochemical emulsion, carbogen breathing, and pentoxifylline, and in all these studies the effects in tumours were always greater than those seen in appropriate normal tissues. Of all the analogs, it is nicotinamide itself which has been the most extensively studied as a radiosensitizer in vivo and the one that shows the greatest effect in animal tumours. It is also an agent that has been well established clinically, with daily doses of up to 6 g, associated with a low incidence of side effects. This human dose is equivalent to 100-200 mg/kg in mice and such doses will maximally sensitize murine tumours to

  5. Radiation Chemistry Studies on Chemotherapeutic Agents

    DEFF Research Database (Denmark)

    Gohn, M.; Getoff, N.; Bjergbakke, Erling

    1977-01-01

    Adrenalin has been studied as a model radiation protective agent by means of pulse radiolysis in aqueous solutions. The rate constants for the reactions of adrenalin with e–aq and OH were determined : k(e–aq+ adr—NH+2)= 7.5 × 108 dm3 mol–1 s–1, k(e–aq+ adr—NH)= 2.5 × 108 dm3 mol–1 s–1, and k......(OH + adr)= 2.2 × 1010 dm3 mol–1 s–1(pH = 9.2). e–aq attacks the amino group by splitting off methylamine, whereas OH and O–aq lead to the formation of the corresponding adducts of the cyclohexadienyl type. OH radicals can also abstract an electron from an O– group at pH > 8....

  6. Ionising Radiation Immediately Impairs Synaptic Plasticity-Associated Cytoskeletal Signalling Pathways in HT22 Cells and in Mouse Brain: An In Vitro/In Vivo Comparison Study

    Science.gov (United States)

    Kempf, Stefan J.; Buratovic, Sonja; von Toerne, Christine; Moertl, Simone; Stenerlöw, Bo; Hauck, Stefanie M.; Atkinson, Michael J.; Eriksson, Per; Tapio, Soile

    2014-01-01

    Patients suffering from brain malignancies are treated with high-dose ionising radiation. However, this may lead to severe learning and memory impairment. Preventive treatments to minimise these side effects have not been possible due to the lack of knowledge of the involved signalling pathways and molecular targets. Mouse hippocampal neuronal HT22 cells were irradiated with acute gamma doses of 0.5 Gy, 1.0 Gy and 4.0 Gy. Changes in the cellular proteome were investigated by isotope-coded protein label technology and tandem mass spectrometry after 4 and 24 hours. To compare the findings with the in vivo response, male NMRI mice were irradiated on postnatal day 10 with a gamma dose of 1.0 Gy, followed by evaluation of the cellular proteome of hippocampus and cortex 24 hours post-irradiation. Analysis of the in vitro proteome showed that signalling pathways related to synaptic actin-remodelling were significantly affected at 1.0 Gy and 4.0 Gy but not at 0.5 Gy after 4 and 24 hours. We observed radiation-induced reduction of the miR-132 and Rac1 levels; miR-132 is known to regulate Rac1 activity by blocking the GTPase-activating protein p250GAP. In the irradiated hippocampus and cortex we observed alterations in the signalling pathways similar to those in vitro. The decreased expression of miR-132 and Rac1 was associated with an increase in hippocampal cofilin and phospho-cofilin. The Rac1-Cofilin pathway is involved in the modulation of synaptic actin filament formation that is necessary for correct spine and synapse morphology to enable processes of learning and memory. We suggest that acute radiation exposure leads to rapid dendritic spine and synapse morphology alterations via aberrant cytoskeletal signalling and processing and that this is associated with the immediate neurocognitive side effects observed in patients treated with ionising radiation. PMID:25329592

  7. Ionising radiation immediately impairs synaptic plasticity-associated cytoskeletal signalling pathways in HT22 cells and in mouse brain: an in vitro/in vivo comparison study.

    Directory of Open Access Journals (Sweden)

    Stefan J Kempf

    Full Text Available Patients suffering from brain malignancies are treated with high-dose ionising radiation. However, this may lead to severe learning and memory impairment. Preventive treatments to minimise these side effects have not been possible due to the lack of knowledge of the involved signalling pathways and molecular targets. Mouse hippocampal neuronal HT22 cells were irradiated with acute gamma doses of 0.5 Gy, 1.0 Gy and 4.0 Gy. Changes in the cellular proteome were investigated by isotope-coded protein label technology and tandem mass spectrometry after 4 and 24 hours. To compare the findings with the in vivo response, male NMRI mice were irradiated on postnatal day 10 with a gamma dose of 1.0 Gy, followed by evaluation of the cellular proteome of hippocampus and cortex 24 hours post-irradiation. Analysis of the in vitro proteome showed that signalling pathways related to synaptic actin-remodelling were significantly affected at 1.0 Gy and 4.0 Gy but not at 0.5 Gy after 4 and 24 hours. We observed radiation-induced reduction of the miR-132 and Rac1 levels; miR-132 is known to regulate Rac1 activity by blocking the GTPase-activating protein p250GAP. In the irradiated hippocampus and cortex we observed alterations in the signalling pathways similar to those in vitro. The decreased expression of miR-132 and Rac1 was associated with an increase in hippocampal cofilin and phospho-cofilin. The Rac1-Cofilin pathway is involved in the modulation of synaptic actin filament formation that is necessary for correct spine and synapse morphology to enable processes of learning and memory. We suggest that acute radiation exposure leads to rapid dendritic spine and synapse morphology alterations via aberrant cytoskeletal signalling and processing and that this is associated with the immediate neurocognitive side effects observed in patients treated with ionising radiation.

  8. Environmental ionising radiation study: Assessment of the public exposure to the environmental gamma and X rays, and to radon in Antananarivo city

    International Nuclear Information System (INIS)

    Radioactivity is one of the indicators of the environmental state because humankind is continuously exposed to ionising radiations. Knowledge of the various components of this natural radioactivity becomes a necessity. As Antananarivo is the most populated city of Madagascar, its environmental radioactivity and radiation dose were assessed with the aim of establishing a database for radioactivity levels. The present work is entitled 'Assessment of the Public Exposure to the Environmental Gamma and X-rays, and to Radon in Antananarivo City'. This paper is the synthesis of several works carried out within the frame of a research project that lasted three years (April 1998-April 2001), consisting of more than a hundred in-situ measurements campaigns and laboratory sample analyses. Ionising radiations were measured through gamma and X ray global counting. Environmental material radioactivity was characterized by in-situ and laboratory gamma spectrometry. Alpha, gamma and X ray dosimetric measurements were done indoor and outdoor, in daytime and at night. The results obtained were the basis for three scientific communications at the Madagascar National Academy of Arts, Letters and Sciences. The first is entitled 'The Cesium-137 Artificial Radioisotope Pollution in Antananarivo City' (June 1998), the second 'the Atmospheric Radon in Antananarivo City '(May 1999), and the third 'Kerma in Air and Counting Rate of the Environmental Gamma and X Rays in Antananarivo City' (December 2000). From this work, the environmental gamma and X ray , and radon contribution to natural radiation doses were obtained. We have found that the population of Antananarivo is exposed to an annual average effective dose of 5.3 mSv.y-1, which is two times higher than the world quoted value.

  9. Probing X-ray photoevaporative winds through their interaction with ionising radiation in cluster environments: the case for X-ray proplyds

    CERN Document Server

    Clarke, C J

    2014-01-01

    We show that if young low mass stars undergo vigorous X-ray driven disc winds, these may be detected in clusters through their interaction with ionising radiation from massive stars. We argue that in the ONC (Orion Nebula Cluster) one should see $\\sim$ 10s of `X-ray proplyds' ( objects with optically imaged offset ionisation fronts) in the range $0.3-0.6$pc from $\\theta_1$C Ori (the dominant O star in the ONC). Such objects lie outside the central `FUV zone' in the ONC where proplyds are instead well explained by neutral winds driven by external Far Ultraviolet (FUV) emission from $\\theta_1$C. We show that the predicted numbers and sizes of X-ray proplyds are compatible with those observed and that this may also explain at least some of the far flung proplyds seen in the Carina nebula. We compare the sizes of observed proplyds outside the FUV region of the ONC with model predictions based on the current observed X-ray luminosities of these sources ( bearing in mind that the current size is actually set by the...

  10. Flash ionisation signature in coherent cyclotron emission from Brown Dwarfs

    CERN Document Server

    Vorgul, Irena

    2016-01-01

    Brown dwarfs form mineral clouds in their atmospheres, where charged particles can produce large-scale discharges in form of lightning resulting in a substantial sudden increase of local ionisation. Brown dwarfs are observed to emit cyclotron radio emission. We show that signatures of strong transient atmospheric ionisation events (flash ionisation) can be imprinted on a pre-existing radiation. Detection of such flash ionisation events will open investigations into the ionisation state and atmospheric dynamics. Such ionisation events can also result from explosion shock waves, bursts or eruptions. We present an analytical model that describes the modulation of a pre-existing electromagnetic radiation by a time-dependent (flash) conductivity that is characteristic for flash ionisation events like lightning. Our conductivity model reproduces the conductivity function derived from observations of Terrestrial Gamma Ray Flashes, and is applicable to astrophysical objects with strong temporal variations in the loca...

  11. Enhancement of tumor radiation response by the antivascular agent 5,6-dimethylxanthenone-4-acetic acid

    International Nuclear Information System (INIS)

    Purpose: 5,6-dimethylxanthenone-4-acetic acid (DMXAA) selectively damages tumor vasculature and is currently in clinical trial as an antitumor agent. Its ability to induce synthesis of tumor necrosis factor (TNF), and its apparent selectivity for poorly-perfused regions in tumors, suggests it possible use in combination with radiotherapy. This investigation examines activity of DMXAA as a radiation modifier using two murine tumors. Methods and Materials: Tumor growth delay was evaluated using i.m. RIF-1 and MDAH-MCa-4 tumors irradiated in unanaesthetised, restrained mice (cobalt-60) using single dose or multiple fractions (8 x 2.5 Gy over 4 days) with DMXAA administered i.p. at various times in relation to irradiation. Results: Administration of DMXAA (80 μmol/kg, i.p.) immediately after radiation resulted in a large increase in tumor growth delay, giving a radiation dose modifying factor of 2.3 for RIF-1 and 3.9 for MDAH-MCa-4. The combination was less active when radiation was given 1-4 h after DMXAA, but was highly active 12-48 h after DMXAA. At the latter times, clamping the tumor blood supply caused a large increase in radioresistance. These studies suggest that cells surviving DMXAA are hypoxic for only a short period. DMXAA increased overall growth delay when administered daily during fractionated irradiation, giving an approximately additive response. Conclusions: The marked synergy between DMXAA and single dose ionising radiation may reflect the complementarity of these agents at the microregional level, with DMXAA preferentially killing hypoxic cells in poorly perfused regions. Despite additional hypoxia shortly after DMXAA treatment, surviving cells appear to reoxygenate quickly which makes it feasible to use DMXAA before and during fractionated radiotherapy. The combination of fractionated radiation and DMXAA appears to be less effective than for single dose radiation (possibly because of the smaller contribution of hypoxia under these conditions), but

  12. Semi-insulating GaAs-based Schottky contacts in the role of detectors of ionising radiation: An effect of the interface treatment

    CERN Document Server

    Ivanco, J; Darmo, J; Krempasky, M; Besse, I; Senderak, R

    1999-01-01

    It is generally agreed that the substrate material quality plays a key role in the performance of back-to-back detectors of ionising radiation based on semi-insulating (SI) material. The aim of this paper is to evaluate usually overlooked problem, namely the influence of the Schottky contact preparation on detector performance. We report on different approaches to modify and control the quality of the metal/SI GaAs interface via a treatment of the SI-GaAs surface by means of low-temperature hydrogen plasma and wet etching. The measured electrical and detecting properties of such structures display a strong dependence on the history and the way the GaAs surface is treated prior to the metal evaporation. We point out, therefore, that the semiconductor surface treatment before the Schottky metallization plays a role of comparable importance to the influence of the SI-GaAs substrate properties on detector performances. (author)

  13. The use of whole body magnetic resonance imaging in detecting bone marrow disorders - a valid alternative to imaging modalities that utilise ionising radiation

    International Nuclear Information System (INIS)

    Imaging modalities for investigation of bone marrow abnormalities have traditionally involved the use of ionising radiation. Now magnetic resonance imaging (MRI) offers an alternative to x-rays, computer tomography (CT), nuclear medicine bone scans and bone mineral densitometry. This study attempts to evaluate the sensitivity and specificity of whole body MRI in detecting bone marrow abnormalities, using Tl and short tau inversion recovery (STIR) weighted sequences. This was achieved by reviewing already acquired scan data to discover whether this method is more sensitive to marrow changes than conventional radiographic skeletal surveys and other imaging tests, involving ionising radiation. The study involved 10 adult participants all of whom suffered from heamatological malignancies, including multiple myeloma, plasma cell dyscrasia, non-Hodgkin's lymphoma and acute lymphocytic leukaemia. Most of the study group presented with multiple myeloma. Abnormal skeletal MRI findings were reported in nine out of the 10 participants, i.e., a positive detection rate of 90%, using whole body MRI. All participants in the study who suffered from multiple myeloma or plasma cell dyscrasia showed positive MRI findings regardless of the stage of their disease. Four already had a confirmed diagnosis prior to the MRI scan, which was either visible on x-ray or bone scintigraphy. Three participants had positive serum/urine tests, but negative radiographic findings. The study therefore established that, when investigating possible marrow disorders, MRI was more sensitive to changes in the bone-marrow producing part of the skeleton and that MRI therefore must be considered a more suitable imaging tool. Copyright (2005) Australian Institute of Radiography

  14. Patient cumulative radiation exposure in interventional cardiology; Exposition cumulee aux rayonnements ionisants des patients en cardiologie interventionnelle: caracteristiques cliniques et dosimetriques

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, M.O.; Jacob, S.; Laurier, D. [Institut de radioprotection et de surete nucleaire (IRSN), DRPH, SRBE, LEPID, Fontenay-aux-Roses (France); Maccia, C. [Centre d' assurance de qualite des applications technologiques dans le domaine de la sante - CAATS, Bourg-la-Reine (France); Bar, O.; Blanchard, D. [Clinique Saint-Gatien, Tours (France); Catelinois, O. [Institut de veille sanitaire, St Maurice (France)

    2012-01-15

    Interventional cardiology procedures can involve potentially high doses of radiation to the patients. Stochastic effects of ionising radiation - radiation-induced cancers in the long term - may occur. We analysed clinical characteristics and dosimetric data in a population of patients undergoing interventional cardiology. In all, 1 591 patients who had undergone coronarography and/or angioplasty in the course of a year at the Saint-Gatien Clinic in Tours (France) were included. Information on patients' individual clinical characteristics and Dose-Area Product values were collected. Organ doses to the lung, oesophagus, bone marrow and breast were mathematically evaluated. The median age of patients was 70 years. Their median cumulative dose-area product value was 48.4 Gy.cm{sup 2} for the whole year and the median effective dose was 9.7 mSv. The median organ doses were 41 mGy for the lung, 31 mGy for the oesophagus, 10 mGy for the bone marrow and 4 mGy for the breast. Levels of doses close to the heart appear to be rather high in the case of repeated interventional cardiology procedures. Clinical characteristics should be taken into account when planning epidemiological studies on potential radiation-induced cancers. (authors)

  15. Ionising radiation induces persistent alterations in the cardiac mitochondrial function of C57BL/6 mice 40 weeks after local heart exposure

    International Nuclear Information System (INIS)

    Background and purpose: Radiotherapy of thoracic and chest-wall tumours increases the long-term risk of radiation-induced heart disease. The aim of this study was to investigate the long-term effect of local heart irradiation on cardiac mitochondria. Methods: C57BL/6 and atherosclerosis-prone ApoE−/− mice received local heart irradiation with a single X-ray dose of 2 Gy. To investigate the low-dose effect, C57BL/6 mice also received a single heart dose of 0.2 Gy. Functional and proteomic alterations of cardiac mitochondria were evaluated after 40 weeks, compared to age-matched controls. Results: The respiratory capacity of irradiated C57BL/6 cardiac mitochondria was significantly reduced at 40 weeks. In parallel, protein carbonylation was increased, suggesting enhanced oxidative stress. Considerable alterations were found in the levels of proteins of mitochondria-associated cytoskeleton, respiratory chain, ion transport and lipid metabolism. Radiation induced similar but less pronounced effects in the mitochondrial proteome of ApoE−/− mice. In ApoE−/−, no significant change was observed in mitochondrial respiration or protein carbonylation. The dose of 0.2 Gy had no significant effects on cardiac mitochondria. Conclusion: This study suggests that ionising radiation causes non-transient alterations in cardiac mitochondria, resulting in oxidative stress that may ultimately lead to malfunctioning of the heart muscle

  16. The critical examination of X-ray generating equipment in diagnostic radiology. Guidance on the interpretation of the Ionising Radiation Regulations 1985, Regulation 32(2)a

    International Nuclear Information System (INIS)

    Regulation 32(2)a requires an examination, where appropriate, of X-ray equipment and its operating environment, following its installation, repair or modification. In this context 'appropriate' means - 'if there are possible radiation protection implications'. The examination should be carried out before the equipment is brought into use. The intent of the Regulation is to ensure that the installation process does not compromise the radiation safety of the equipment as provided for by its original design and manufacture, and that any persons who might be exposed are adequately protected. However, the scope of the Regulation does not directly cover features controlling the optimisation of dose for a medical exposure. An examination of the equipment relating to the radiation protection consequences of the way it was installed is required. This is termed 'critical', emphasising the need to review the installation to a greater degree than the simple fulfilment of a preconceived test procedure. The involvement of a radiation protection adviser is required as an expert in radiation safety. This document provides guidance on when it is necessary to carry out a critical examination, and on its content. The Ionising Radiations Regulations 1985 firmly place the responsibility for ensuring that a critical examination is carried out, on the installer of the equipment. However, knowledge of various aspects of the critical examination is also relevant to employers who manage health related facilities, as well as their RPAs, and physicists who carry out equipment tests. Aside from the actual examination itself, there are issues pertaining to purchase contracts, and a knowledge of the satisfactory completion of a critical examination will be relevant to an employer in fulfilling his duties under Regulations 6 and 33. (author)

  17. Predicting the effect of ionising radiation on biological populations: testing of a non-linear Leslie model applied to a small mammal population

    International Nuclear Information System (INIS)

    The present work describes the application of a non-linear Leslie model for predicting the effects of ionising radiation on wild populations. The model assumes that, for protracted chronic irradiation, the effect-dose relationship is linear. In particular, the effects of radiation are modelled by relating the increase in the mortality rates of the individuals to the dose rates through a proportionality factor C. The model was tested using independent data and information from a series of experiments that were aimed at assessing the response to radiation of wild populations of meadow voles and whose results were described in the international literature. The comparison of the model results with the data selected from the above mentioned experiments showed that the model overestimated the detrimental effects of radiation on the size of irradiated populations when the values of C were within the range derived from the median lethal dose (L50) for small mammals. The described non-linear model suggests that the non-expressed biotic potential of the species whose growth is limited by processes of environmental resistance, such as the competition among the individuals of the same or of different species for the exploitation of the available resources, can be a factor that determines a more effective response of population to the radiation effects. -- Highlights: • A model to assess the radiation effects on wild population is described. • The model is based on non-linear Leslie matrix. • The model is applied to small mammals living in an irradiated meadow. • Model output is conservative if effect-dose factor estimated from L50 is used. • Systemic response to stress of populations in competitive conditions may be more effective

  18. The legal situation of the radiation protection agent

    International Nuclear Information System (INIS)

    The radiation protection agent is an entirely office-internal institution and no public-legal control instance. Its task solely consists of supporting the person responsible for radiation protection in fulfilling his/her duties concerning radiation protection thus enabling him/her to do his/her public-legal duties. Adherence to these duties is controlled by the authority without regard to the person responsible for radiation protection (paragraph 32). The radiation protection agent only acts on private level in reaction to the person responsible for radiation protection. Interpretation of the concrete legal relationships depends on the point if the radiation protection agent acts as internal or external expert. In the first case, the relationship is based on a work contract, i.e. any legal arguing must be carried out at employment courts. There is no special protection for the radiation protection agent concerning his time of notice. In the case of an external radiation protection agent, the mutual duties are legally based on the work or employment contract which was signed on the basis of civil law. Arguments are subject to orderly courts. (orig./HP)

  19. About the contribution of occupational health's services for risk factors evaluation, medical and dosimetric follow-up in the workers monitoring exposed to ionising radiations in France

    International Nuclear Information System (INIS)

    Full text of publication follows: French national regulation (31/03/2003) indicates principles of a global approach about the medical and dosimetric follow-up in the workers monitoring. Legislator insists on risks and expositions trace ability along all professional career and after. The aim of this French specific system is to institute medical clinic aspects in accordance with dosimetry and professional risks. The occupational practitioners are approved practitioners who have followed a specific training. The organisation guarantees that a worker will be followed by one specific practitioner in order to reinforce the quality and the traceability of follow up. Medical supervision is done at taking on and at least once a year. It means to identify and take care of risks and expositions at work stations. If necessary, biological measurements and recommendations about collective and individual protection equipments complete the estimation of risks. On the subject of emergency, first aid is delivered on sites by occupational health personnel, either for classic medical problem or for radiological accident. Furthermore, occupational health personnel assist outside emergency services with whom we have specific conventions. External dosimetric follow-up is done with radiation protection qualified expert of the company. The internal contamination supervision and internal dose evaluation are done by the occupational health services. Measurements either whole body counts or radio-toxicologic analysis are submitted to technical quality process. Beyond the respect of regulatory dose limits, the aim of the dosimetric follow-up is the contribution to the preparation of work places with strong dosimetric focus. Informations at workers are dispensed about every risks and every kinds of risks: ionising radiation health effects, ionising radiation and pregnancy, high exposition, chemical risks, work at heat, asbestos. All data are conserved 50 years after the exposure These data

  20. Biological effects of the ionizing radiation. Press breakfast; Effets biologiques des rayonnements ionisants. Petit dejeuner de presse

    Energy Technology Data Exchange (ETDEWEB)

    Flury-Herard, A. [CEA, Direction des Sciences du Vivant, DSV, 75 - Paris (France); Boiteux, S.; Dutrillaux, B. [CEA/Fontenay-aux-Roses, Direction des Sciences du Vivant, DSV, 92 (France); Toledano, M. [CEA Saclay, Direction des Sciences du Vivant, DSV, 91 - Gif-sur-Yvette (France)

    2000-06-01

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

  1. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996-1999. Biophysical models for the induction of cancer by radiation. Final report

    International Nuclear Information System (INIS)

    The overall project is organised into seven work packages. WP1 concentrates on the development of mechanistic, quantitative models for radiation oncogenesis using selected data sets from radiation epidemiology and from experimental animal studies. WP2 concentrates on the development of mechanistic, mathematical models for the induction of chromosome aberrations. WP3 develops mechanistic models for radiation mutagenesis, particularly using the HPRT-mutation as a paradigm. WP4 will develop mechanistic models for damage and repair of DNA, and compare these with experimentally derived data. WP5 concentrates on the improvement of our knowledge on the chemical reaction pathways of initial radiation chemical species in particular those that migrate to react with the DNA and on their simulation in track structure codes. WP6 models by track structure simulation codes the production of initial physical and chemical species, within DNA, water and other components of mammalian cells, in the tracks of charged particles following the physical processes of energy transfer, migration, absorption, and decay of excited states. WP7 concentrates on the determination of the start spectra of those tracks considered in WP6 for different impinging radiation fields and different irradiated biological objects. (orig.)

  2. Food ionisation. Realities and perspectives; L'ionisation alimentaire. Realites et perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G

    1994-06-01

    The ionisation of food is a treatment using a certain type of energy. the radiations used in the industrial treatments are limited to three sources. The gamma radiations, the x radiations and the electrons beams emitted with accelerators. The physical treatments by ionizing radiations have for aim to cleanse and to increase the conservation time of food. Now, the applications in agriculture and food industry, are still marginal. The industrial using ionisation are these ones that did not find any alternative decontamination method. The barriers are more scientific or technical or economical than a question of regulation or behaviour. (N.C.)

  3. Direct measurements of plutonium in man: A report on developments made to meet the requirements of the new ionising radiation regulations

    International Nuclear Information System (INIS)

    In preparation for the introduction of the United Kingdom Ionising Radiation Regulations (IRRs), based on the Euratom Directive 1980 and ICRP 26, Winfrith have re-examined their approach to the direct measurement of plutonium and plutonium-based fuel mixtures in the lung. The results of lung monitoring will be combined with the results of other monitoring regimes on a computer data base to form an overall assessment of plutonium dosimetry for an individual. Calibrations using a realistic chest phantom and tissue equivalent overlays are discussed together with the treatment and prediction of subject backgrounds. The limits of detection of the developed techniques are considered in relation to the requirement to demonstrate compliance with the IRRs and the Annual Limit on Intake concept. The re-examination shows that compliance can be demonstrated using techniques employing a knowledge of the plutonium fuel mixture when ICRP metabolic behaviour is assumed. An outline is also given of the application of this technique using the observed metabolic behaviour of Winfrith-type plutonium fuel mixtures and corresponding derived Annual Limits on Intake. (author)

  4. The place of ionizing radiation in the cancer genesis; La place des rayonnements ionisants dans la genese des cancers

    Energy Technology Data Exchange (ETDEWEB)

    Simon, J. [Societe Francaise d' Energie Nucleaire, 75 - Paris (France)

    2009-12-15

    Two different fields are considered: the field of high radiation doses (over 1 Sv), the contribution of ionizing radiation in the carcinogenesis is doubtless and the linear dose-effect relationship is unshakable. but this high doses area is rare ( major accident of civil nuclear, radiotherapy, war with use of nuclear weapon) and escapes to usual standards. The field of low dose irradiation (inferior to 100 MSv) we cannot assure the absence of carcinogen risk of ionizing radiation. We can tell that this risk is very low, very inferior to 5% by sievert accepted by the ICRP in conformance with the precautionary principle. In any case, very inferior to the risk in relation with the big causes of cancer that are addiction to smoking, (30% of cancers), food (30% of cancers), chronic diseases (11% of cancers) and hormonal processes (10% of cancers). (N.C.)

  5. Training strategic community agents in health effects of ionizing radiation

    International Nuclear Information System (INIS)

    The main motivation for the development of training was the need to train agents (opinion makers) with proximity and credibility among the population, to clarify the most frequently asked questions in relation to ionizing radiation, the operation of nuclear power plants, emergency plans and about the possibility of there effects of radiation on the health of inhabitants in regions close to the central Nuclear Almirante Alvaro Alberto - CNAAA. The project has a target audience of 420 agents, 60 of them have already been trained in a pilot project . The results indicate that the topics of training were adequate and the agents have expanded their knowledge. On the other hand, the information passed on to communities by agents, recognized by this population as ' the most reliable people', is of greater credibility and likelihood of success in communicating important issues for the population living in the vicinity of the CNAAA. (author)

  6. Occupational exposures to ionising radiation in the region of Anatolia, Turkey for the period 1995-1999

    International Nuclear Information System (INIS)

    For this study, the individual annual dose information on classified workers who are occupationally exposed to extended radiation sources in Turkey, was assessed and analysed by the Ankara Nuclear Research and Training Centre dosimetry service at the Turkish Atomic Energy Authority for the years 1995-1999. The radiation workers monitored are divided into three main work sectors: conventional industry (8.24%), medicine (90.20%) and research-education (1.56%). The average annual dose for all workers in each particular sector was 0.14, 0.38 and 0.08 mSv, respectively, in 1995-1999. This paper contains the detailed analysis of occupational exposure. The statistical analysis provided includes the mean annual dose, the collective dose, the distributions of the dose over the different sectors and the number of workers who have exceeded any of the established dose levels. (authors)

  7. Significance of 8-oxoG in the spectrum of DNA damages caused by ionising radiation of different quality

    Czech Academy of Sciences Publication Activity Database

    Štěpán, Václav; Davídková, Marie

    2007-01-01

    Roč. 122, 1-4 (2007), s. 113-115. ISSN 0144-8420. [Symposium on Microdosimetry /14./. Venezia, 13.11.2005-18.11.2005] R&D Projects: GA AV ČR KJB4048401; GA ČR GA202/05/2728 Institutional research plan: CEZ:AV0Z10480505 Keywords : DNA damage * 8-oxoguanine * ionizing radiation * theoretical modeling Subject RIV: BO - Biophysics Impact factor: 0.528, year: 2007

  8. Effects of ionising radiation on plants and animals: What we now know and still need to learn

    International Nuclear Information System (INIS)

    Full text: The intent of this presentation was to provide a broad review of the status of existing knowledge on the effects of ionizing radiation on plants and animals, in the context of field rather than laboratory settings, and to offer thoughts on what more we need to learn in order to set protection criteria and test for compliance with greater confidence. General findings from historical studies on designed and accidental irradiation of plant communities and animals, including comparative radiosensitivity and modifying factors, were reviewed. Experimental limitations of most studies and difficulties in response interpretation were discussed in reference to ecological relevance and protection criteria. Recovery of radiation damaged plant communities and animal populations, both during and after radiation exposure, were discussed. The commonly measured responses, mortality and reproduction, were reviewed and questioned as the most radiosensitive, ecologically-relevant endpoints. Our perceptions of major knowledge gaps on effects of ionizing radiation on the environment were reviewed, and the types of specific studies that appear needed were presented. These needs were discussed under the general headings of dosimetry, damage endpoints, and dose/response relationships. In the area of dosimetry for example, more work is needed on critical species identification, dose model refinements to account for temporal and spatial dose distribution, and RBEs for various damage endpoints. It is known that biological effects such as genomic damage occur in organisms at dose rates well-below those required to obviously impair reproduction. The question is, are such effects harmful to populations in the irradiated generation or in succeeding generations, and if so, under what conditions? Many species and ecosystems have not been experimentally irradiated, either with relatively uniform photon exposures from sealed sources, or from radioactive contamination, which produces large

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

    International Nuclear Information System (INIS)

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

  10. Guideline for radiation protection in veterinary medicine. Guideline relating to the Ordinance for Protection Against Damage Through Ionising Radiation (Radiation Protection Ordinance - StrlSchV) and the Ordinance for Protection Against X-Ray Radiation (X-Ray Ordinance - RoeV)

    International Nuclear Information System (INIS)

    The Guideline on ''Radiation Protection in Veterinary Medicine'' primarily addresses the supreme Land authorities that are responsible for radiation protection. Its purpose is to harmonise the radiation protection procedures employed by the Laender, thus establishing a nationwide uniform system for monitoring the handling of radioactive substances and ionising radiation applications in veterinary medicine on the basis of the legal regulations in force. In addition the guideline is intended to serve veterinary staff as a source of practical information which explains the radiation protection requirements stipulated by the legal regulations and technical rules. This concerns in particular the rules for the acquisition of the necessary radiation protection skills or the necessary knowledge of radiation protection by the veterinary surgeon performing the application or the staff cooperation in the application

  11. The principal phenolic and alcoholic components of wine protect human lymphocytes against hydrogen peroxide- and ionising radiation-induced DNA damage in vitro

    International Nuclear Information System (INIS)

    the DNA damaging effects of two important oxidants ie hydrogen peroxide and ionising radiation, in this physiologically relevant in vitro system

  12. Resistance of male gamete function to ionising radiation: Implications in evolution and in induced transformation in higher organisms

    International Nuclear Information System (INIS)

    In plants, highly irradiated pollen grains are capable of growing, discharging their fragmented DNA into the egg, and causing egg transformation. The present study suggests that sperms of higher animals are similarly resistant to radiation damage to their DNA delivery function, i.e., their motility. This observation, taken in conjunction with available evidence regarding pseudo-fertilisation and polyspermy after insemination with irradiated spermatozoa, suggests that recovery of egg-transformed progeny may be possible in animals as well as in plants. Evolutionary implications of gametic resistance are discussed. (auth)

  13. Interaction of ionising radiation and acidulants on the growth of the microflora of a vacuum-packaged chilled meat product

    International Nuclear Information System (INIS)

    Microbiological effects of gamma irradiation dose of 2 kGy, with and without reduction of pH to 5.3-5.2, have been investigated with a vacuum-packaged, minced meat product prepared from pork and beef with spices and cereal fillings. Either glucono-delta-lactone or ascorbic acid were used as acidulants. Experimental batches were stored at 0-2 degrees C for 4 weeks. Effect of temperature abuse condition was also studied by transferring packages for one week to 10 degrees C after 2-week holding at 0-2 degrees C. The irradiation caused two decimal reduction of the aerobic viable cell count determined after incubation at room temperature and four decimal reduction in the Enterobacteriaceae count. Lactic acid bacteria appeared to be more radiation resistant and became the dominant component of the microflora during storage. Combination of pH-reduction and irradiation prevented growth of Enterobacteriaceae even at 10 degrees C incubation. (author)

  14. The use of ionising radiation for the treatment of injuries to flexor tendons and supporting ligaments in horses

    International Nuclear Information System (INIS)

    A technique was developed using radioactive isotopes as a source of radiation for the treatment of injuries to the superficial and deep flexor tendons and the associated ligaments in the horse. The treatment area was sub-divided so that different dosages could be applied over the limb as necessary. A plaster of Paris impression was taken on the whole area to be treated. In the isotope laboratory a plaster negative was made and loaded with the dose of radioactive isotope. The loaded cast was then strapped to the horse's limb for the calculated time, usually about three days. A total of 42 horses were treated and follow up information was obtained from 28. Twenty-five animals raced again: two relapsed before racing and one was destroyed with navicular disease. Ten of the 42 horses had been treated by firing before irradiation. Five of these returned to racing but the history of four of them was not known. (author)

  15. Nuclear law: nuclear matter and ionizing radiation sources. Wastes; Droit nucleaire: matieres nucleaires et sources de rayonnements ionisants. Dechets

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-15

    The object of this work is since its first edition in 1983 under the title 'Collection of nuclear activities legislation and regulation ' to realize an ordered collection of texts constituting the juridical and institutional frame of nuclear activities, gathering the legislative, regulatory and technical texts; the international, European and national texts. Aiming to include the whole of the atom applications, this collection tackles various themes, in ten chapters.The volume number two includes the following chapters: nuclear matters and ionizing radiations sources; wastes. Previously edited by the Cea, that realizes it it is now published in the collection 'Legislation and regulation' of officials journals editions. (N.C.)

  16. Bio dosimetric tools for a fast triage of people accidentally exposed to ionising radiation. Statistical and computational aspects

    International Nuclear Information System (INIS)

    Consideration of statistical methodology is essential for the application of cytogenetic and other bio dosimetry techniques to triage for mass casualty situations. This is because the requirement for speed and accuracy in bio dosimetric triage necessarily introduces greater uncertainties than would be acceptable in day-to-day bio dosimetry. Additionally, in a large scale accident type situation, it is expected that a large number of laboratories from around the world will assist and it is likely that each laboratory will use one or more different dosimetry techniques. Thus issues arise regarding combination of results and the associated errors. In this article we discuss the statistical and computational aspects of radiation bio dosimetry for triage in a large scale accident-type situation. The current status of statistical analysis techniques is reviewed and suggestions are made for improvements to these methods which will allow first responders to estimate doses quickly and reliably for suspected exposed persons.

  17. An evaluation of the shielding effectiveness of lead aprons used in clinics for protection against ionising radiation from novel radioisotopes.

    Science.gov (United States)

    Deb, Pradip; Jamison, Robert; Mong, Lisa; U, Paul

    2015-07-01

    The purpose of this study is to evaluate the effectiveness of personal radiation shields currently worn in hospital and other diagnostic environments. This study was performed with four different radioisotopes; (18)F, (99m)Tc, (124)I and (131)I. (18)F results showed a decrease in dose with 0.5-mm Pb shielding but the reduction provided does not warrant its use clinically. (124)I testing demonstrated that dose enhancement can occur in greater shield thicknesses. PET isotope (124)I can be adequately shielded using 0.25-mm Pb equivalent aprons but any higher thickness increase the wearer's dose. As a result more shielding does not always equal more protection. The (131)I test showed that no dose reduction occurred, even when tested with up to 1.25-mm Pb equivalent shielding. Novel radioisotopes being used in the laboratory and clinic should be individually tested as each requires specific shielding testing. PMID:25848112

  18. Assessing the performance under ionising radiation of lead tungstate scintillators for EM calorimetry in the CLAS12 Forward Tagger

    Energy Technology Data Exchange (ETDEWEB)

    Fegan, S., E-mail: fegan@ge.infn.it [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Auffray, E. [CERN, European Organisation for Nuclear Research, Geneva (Switzerland); Battaglieri, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Buchanan, E. [University of Glasgow, Glasgow G12 8QQ (United Kingdom); Caiffi, B.; Celentano, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Colaneri, L.; D' Angelo, A. [Istituto Nazionale di Fisica Nucleare, Sezione Roma2 Tor Vergata and Università degli studi di Roma Tor Vergata, Via Scientifica 1, 00133 Roma (Italy); De Vita, R. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Dormenev, V. [II. Physikalisches Institut, Universität Gießen, 35392 Gießen (Germany); Fanchini, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Genova and Dipartimento di Fisica dell' Universitá, Via Dodecaneso 33, 16146 Genova (Italy); Lanza, L. [Istituto Nazionale di Fisica Nucleare, Sezione Roma2 Tor Vergata and Università degli studi di Roma Tor Vergata, Via Scientifica 1, 00133 Roma (Italy); Novotny, R.W. [II. Physikalisches Institut, Universität Gießen, 35392 Gießen (Germany); and others

    2015-07-21

    The well-established technology of electromagnetic calorimetry using Lead Tungstate crystals has recently seen an upheaval, with the closure of one of the most experienced large-scale suppliers of such crystals, the Bogoroditsk Technical Chemical Plant (BTCP), which was instrumental in the development of mass production procedures for PWO-II, the current benchmark for this scintillator. Obtaining alternative supplies of Lead Tungstate crystals matching the demanding specifications of contemporary calorimeter devices now presents a significant challenge to detector research and development programmes. In this paper we describe a programme of assessment carried out for the selection, based upon the performance under irradiation, of Lead Tungstate crystals for use in the Forward Tagger device, part of the CLAS12 detector in Hall B at Jefferson Lab. The crystals tested were acquired from SICCAS, the Shanghai Institute of Ceramics, Chinese Academy of Sciences. The tests performed are intended to maximise the performance of the detector within the practicalities of the crystal manufacturing process. Results of light transmission, before and after gamma ray irradiation, are presented and used to calculate dk, the induced radiation absorption coefficient, at 420 nm, the peak of the Lead Tungstate emission spectrum. Results for the SICCAS crystals are compared with identical measurements carried out on Bogoroditsk samples, which were acquired for the Forward Tagger development program before the closure of the facility. Also presented are a series of tests performed to determine the feasibility of recovering radiation damage to the crystals using illumination from an LED, with such illumination available in the Forward Tagger from a light monitoring system integral to the detector.

  19. Assessing the performance under ionising radiation of lead tungstate scintillators for EM calorimetry in the CLAS12 Forward Tagger

    International Nuclear Information System (INIS)

    The well-established technology of electromagnetic calorimetry using Lead Tungstate crystals has recently seen an upheaval, with the closure of one of the most experienced large-scale suppliers of such crystals, the Bogoroditsk Technical Chemical Plant (BTCP), which was instrumental in the development of mass production procedures for PWO-II, the current benchmark for this scintillator. Obtaining alternative supplies of Lead Tungstate crystals matching the demanding specifications of contemporary calorimeter devices now presents a significant challenge to detector research and development programmes. In this paper we describe a programme of assessment carried out for the selection, based upon the performance under irradiation, of Lead Tungstate crystals for use in the Forward Tagger device, part of the CLAS12 detector in Hall B at Jefferson Lab. The crystals tested were acquired from SICCAS, the Shanghai Institute of Ceramics, Chinese Academy of Sciences. The tests performed are intended to maximise the performance of the detector within the practicalities of the crystal manufacturing process. Results of light transmission, before and after gamma ray irradiation, are presented and used to calculate dk, the induced radiation absorption coefficient, at 420 nm, the peak of the Lead Tungstate emission spectrum. Results for the SICCAS crystals are compared with identical measurements carried out on Bogoroditsk samples, which were acquired for the Forward Tagger development program before the closure of the facility. Also presented are a series of tests performed to determine the feasibility of recovering radiation damage to the crystals using illumination from an LED, with such illumination available in the Forward Tagger from a light monitoring system integral to the detector

  20. Health and biological effects of non-ionizing radiations; Effets biologiques et sanitaires des rayonnements non ionisants

    Energy Technology Data Exchange (ETDEWEB)

    De Seze, R.; Souques, M.; Aurengo, A.; Bach, V.; Burais, N.; Cesarini, J.P.; Cherin, A.; Decobert, V.; Dubois, G.; Hours, M.; Lagroye, I.; Leveque, Ph.; Libert, J.P.; Lombard, J.; Loos, N.; Mir, L.; Perrin, A.; Poulletier De Gannes, F.; Thuroczy, G.; Wiart, J.; Lehericy, St.; Pelletier, A.; Marc-Vergnes, J.P.; Douki, Th.; Guibal, F.; Tordjman, I.; Gaillot de Saintignon, J.; Collard, J.F.; Scoretti, R.; Magne, I.; Veyret, B.; Katrib, J.

    2011-07-01

    This document gathers the slides of the available presentations given during this conference day on the biological and health effects of non-ionizing radiations. Sixteen presentations out of 17 are assembled in the document and deal with: 1 - NMR: biological effects and implications of Directive 2004/40 on electromagnetic fields (S. Lehericy); 2 - impact of RF frequencies from mobile telephone antennas on body homeostasis (A. Pelletier); 3 - expression of stress markers in the brain and blood of rats exposed in-utero to a Wi-Fi signal (I. Lagroye); 4 - people exposure to electromagnetic waves: the challenge of variability and the contribution of statistics to dosimetry (J. Wiart); 5 - status of knowledge about electromagnetic fields hyper-sensitivity (J.P. Marc-Vergnes; 6 - geno-toxicity of UV radiation: respective impact of UVB and UVA (T. Douki); 7 - National day of prevention and screening for skin cancers (F. Guibal); 8 - UV tan devices: status of knowledge about cancer risks (I. Tordjman, and J. Gaillot de Saintignon); 9 - modulation of brain activity during a tapping task after exposure to a 3000 {mu}T magnetic field at 60 Hz (M. Souques and A. Legros); 10 - calculation of ELF electromagnetic fields in the human body by the finite elements method (R. Scoretti); 11 - French population exposure to the 50 Hz magnetic field (I. Magne); 12 - LF and static fields, new ICNIRP recommendations: what has changed, what remains (B. Veyret); 13 - risk assessment of low energy lighting systems - DELs and CFLs (J.P. Cesarini); 14 - biological effects to the rat of a chronic exposure to high power microwaves (R. De Seze); 15 - theoretical and experimental electromagnetic compatibility approaches of active medical implants in the 10-50 Hz frequency range: the case of implantable cardiac defibrillators (J. Katrib); French physicians and electromagnetic fields (M. Souques). (J.S.)

  1. The Utility of Lymphocyte Premature Chromosome Condensation Analysis for Biological Dosimetry Following Accidental Overexposure to Ionising Radiation

    International Nuclear Information System (INIS)

    Premature chromosome condensation (PCC) appears to have a possible utility for biological dosimetry purposes. The PCC technique may be adapted for cases of suspicion of overexposure where sampling is performed at least one day after an accident. For this purpose, human blood samples were exposed in vitro to 60Co (0.5 Gy.min-1) up to 4 Gy and the PCC technique was performed after 24 h, 48 h, and 72 h of DNA repair at 37 deg. C. Analysis of excess PCC fragments distribution showed an overdispersion and the dose-effect relationship was best characterised by linear regression. Radiation-induced damage was reduced to 32% between the first and the second day of repair and to 42% the following day. Statistical precision of the dose was found to be dependent on the irradiation dose and on the number of cells examined. The necessity to establish dose-response relationships after different periods of DNA repair is demonstrated, and the use of PCC excess fragments yield as a bioindicator should take this fact into account. (author)

  2. Radiological risk from Am-241 in ionisation smoke chambers

    International Nuclear Information System (INIS)

    The author discusses the risk to man from the use of ionisation smoke chamber detectors with an Am-241 radiation source. The estimated dose is compared with that due to natural radioactivity. (G.T.H.)

  3. Policy, development and delivery of education and training programmes in radiation protection: a crucial contribution to the safe use of ionising radiation

    International Nuclear Information System (INIS)

    Need for radiation protection knowledge, skills and competences: Today’s situation - Over past years: decrease in number of high-level competences in radiation protection. However, increased attention to RP is needed: more technologies (and more frequently used) rely on ionizing radiation. Actions: Fill the gap - Increase awareness that knowledge of RP science and adequate skills are important (at all levels in medical, industry, research, …). Prepare for future needs - Support of young students and professionals in their need to gain and maintain high level radiation protection competences. Attract new people: Provide adequate E and T - Develop good infrastructure for education and training: → to combat the decline in expertise; → to assure high level of future RP knowledge and skills; → Overall safe use of ionizing radiation

  4. Electron beam radiation of resin luting agents - a cytotoxic evaluation

    International Nuclear Information System (INIS)

    The aim of this study was to evaluate and compare the cytotoxicity of three resin luting agents rely x luting cement, rely x luting 2 cement, and clearfil SA luting agent on human dental pulp cells before and after electron beam irradiation. Growth and maintenance of cell cultures of human pulp cells was done in Dulbecco's modified Eagle's Medium (DMEM). The test samples were divided into two categories based on radiation exposure, irradiated category and non-radiated category. Samples in Irradiated category were exposed to electron beam radiation after dose standardisation (Microtron, Electron Beam Accelerator, Microtron Centre, Mangalore University). The dose of radiation used was 200 Gy. Two subgroups of radiated category were made. In 1st sub-group (containing 18 samples), all the 3 luting cements will be placed in sterile packets and irradiated without mixing the two components. In 2nd sub-group (containing 18 samples), all the 3 luting cements will be mixed separately, placed in sterile packets and exposed to electron-beam radiations. Samples in non radiated category were also made 2 groups. In 1st sub-group (containing 18 samples), all the 3 luting cements will be placed in sterile teflon moulds and kept in a humid chamber at 37℃ without mixing the two components. In 2nd sub-group (containing 18 samples), all the 3 the luting cements will be mixed separately, placed in sterile teflon moulds and kept in a humid chamber at 37℃. All the samples were subjected to MTT assay and spectrophotometric analysis and their cytotoxicity was assessed. (author)

  5. Formulas for ionization yield functions and ionisation capability of solar cosmic rays in the ionosphere and atmosphere

    International Nuclear Information System (INIS)

    The solar cosmic rays produced in solar flares (and in some other high energy solar processes) are one of the most important manifestations of solar activity and one of the main agents in solar-terrestrial relationships. Two approaches have been developed to compute the CR ionisation, e.g.: i ) the model CORIMIA – COsmic Ray Ionisation Model for Ionosphere and Atmosphere is analytical, while ii ) CORSIKA code, including the FLUKA Monte Carlo package is statistical; it is based on a Monte Carlo simulation of the atmospheric cascade. Usually the analytical models use the ionisation capability C function, while the statistical simulations utilize the ionisation yield Y function. In the present work formulas for ionisation capability C and ionisation yield functions Y are derived for the solar cosmic rays, i.e. for sub-relativistic approximation. Some practical applications are discussed. Key words: solar cosmic rays, iono/atmosphere system, ionisation capability, ionisation yield function

  6. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996 - 1999. Mid-term reports for the period 1996-1997

    International Nuclear Information System (INIS)

    The main objectives of the first dosimetry project are the measurement of neutron and charged particle flux and energy spectra at altitudes in civil aviation, the determination of response characteristics for detectors, the investigation of calibration procedures, and the evaluation of exposures of aircrews. The overall objective of the second dosimetry project is to improve estimates of dose following the intake of radionuclides by adults and children. The work includes the development of biokinetic and dosimetric models, including models of the gastrointestinal tract, for the systemic behaviour of radionuclides, and for the developing embryo and foetus. Further subjects are target cell dosimetry for short-range particles and the development of computational tools for sensitivity and uncertainty analysis models. The third dosimetry project encompasses the study of different methods for retrospective dose assessments for individuals or groups of individuals accidentally exposed to increased levels of radiation. The methods investigated include electron paramagnetic resonance (EPR) of tooth enamel and chromosome painting (FISH) for lymphocytes in peripheral blood for individual retrospective dose assessments, luminescence techniques on materials in inhabited environment (ceramics, bricks) and model calculations using environmental data as input. (orig.)

  7. Radiation fields, dosimetry, biokinetics and biophysical models for cancer induction by ionising radiation 1996 - 1999. Mid-term reports for the period 1996-1997

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, P.; Paretzke, H.G.; Roth, P. [GSF - Forschungszentrum fuer Umwelt und Gesundheit Neuherberg GmbH, Oberschleissheim (Germany). Inst. fuer Strahlenschutz; Michael, B.D. [Mount Vernon Hospital, Northwood (United Kingdom). Gray Lab.; O`Sullivan, D. [Dublin Inst. for Advanced Studies (Ireland)

    1998-12-31

    The main objectives of the first dosimetry project are the measurement of neutron and charged particle flux and energy spectra at altitudes in civil aviation, the determination of response characteristics for detectors, the investigation of calibration procedures, and the evaluation of exposures of aircrews. The overall objective of the second dosimetry project is to improve estimates of dose following the intake of radionuclides by adults and children. The work includes the development of biokinetic and dosimetric models, including models of the gastrointestinal tract, for the systemic behaviour of radionuclides, and for the developing embryo and foetus. Further subjects are target cell dosimetry for short-range particles and the development of computational tools for sensitivity and uncertainty analysis models. The third dosimetry project encompasses the study of different methods for retrospective dose assessments for individuals or groups of individuals accidentally exposed to increased levels of radiation. The methods investigated include electron paramagnetic resonance (EPR) of tooth enamel and chromosome painting (FISH) for lymphocytes in peripheral blood for individual retrospective dose assessments, luminescence techniques on materials in inhabited environment (ceramics, bricks) and model calculations using environmental data as input. (orig.)

  8. The effect of nucleating agent on radiation stability of polypropylene

    International Nuclear Information System (INIS)

    The radiation stability of polypropylene (PP) with and without nucleating agent (NA) is compared in relation to radiation sterilization of medical devices. In both cases high-and-low-molecular weight PP, the addition of NA increased the transparency and peak crystallization temperature of the PP. On the other hand, in poly(propylene-co-06%ethylene) copolymer, the addition of NA did not improve the transparency but crystallization occurred at higher temperature. Thus, adding NA to PP and copolymer give the advantage of shorter moulding time in the production of medical devices. It is found that both PP and copolymer with NA are less stable during irradiation and during storage after irradiation than without NA, this being the case especially for the lower molecular weight PP. The higher transparency and peak crystallization temperature in the PP and CP with NA were found to be due to smaller spherulites. As the effect of irradiation on polymer, addition of NA induce reduction of radiation stability of polymer owing to the change in morphology. (Author)

  9. Effects of the ionising radiations on the structure and the function of the intestinal epithelial cell; Effets des rayonnements ionisants sur la structure et la fonction de la cellule epitheliale intestinale

    Energy Technology Data Exchange (ETDEWEB)

    Haton, C

    2005-06-15

    The intestinal mucosa is a particularly radio-sensitive tissue and damage may occur following either accidental or therapeutic exposure. the deleterious actions of ionizing radiation are linked to the formation of sometimes overwhelming quantities of reactive oxygen species (R.O.S.). Production of R.O.S. is both direct and indirect from the secondary effects of irradiation. A better comprehension of the underlying mechanisms of injury will lead to more adapted therapeutic approaches to limit the harmful effects of irradiation. The homeostasis of the intestinal epithelium is regulated by three factors: proliferation, apoptosis and differentiation. these three factors were studied using the cell model, HT29, in order to analyze modulations of this balance after irradiation. our results, in agreement with other data, showed the establishment of mitotic delay. This arrest of proliferation was followed by apoptosis to be the major mechanism leading to cell death in this model. thus, for the first time, we have shown that irradiated intestinal epithelial cells preserve their capacity to differentiate. This indicates, although indirectly, that intestinal cells have and preserve an intrinsic capacity restore a functional epithelium. R.O.S. are considered as intermediates between the physical nature of radiations and biological responses. It seems essential to understand anti-oxidant mechanisms used by the cell for defence against the deleterious effects of R.O.S post exposure. This study of several anti-oxidant defence mechanisms of intestinal mucosa, was carried out in vivo in the mouse at different times following abdominal irradiation. We observed an early mitochondrial response in the hours following irradiation revealing this organelle as a particular target. We demonstrated a strong alteration of anti-oxidant capacity as revealed by a decrease in S.O.D.s, catalase and an increase of the G.P.X.s and M.T.s. A part of these modifications appeared to depend on an

  10. Comparison of radiation dosimetry for several potential myocardial imaging agents

    International Nuclear Information System (INIS)

    Although myocardial imaging is currently dominated by Tl-201, several alternative agents with improved physiologic or radionuclidic properties have been proposed. Based on human and animal studies in the literature, the metabolism of several of these compounds was studied for the purpose of generating radiation dose estimates. Dose estimates are listed for several I-123-labeled free fatty acids, an I-123-labeled phosphonium compound, Rb-82, Cu-64, F-18 FDG (all compounds which are taken up by the normal myocardium), and for Tc-99m pyrophosphate (PYP) (which localizes in myocardial infarcts). Dose estimates could not be generated for C-11 palmitate, but his compound was included in a comparison of myocardial retention times. For the I-123-labeled compounds, I-124 was included as a contaminant in generating the dose estimates. Radiation doses were lowest for Rb-82 (gonads 0.3-0.4 Gy/MBq, kidneys 8.6 Gy/MBq). Doses for the I-123-labeled fatty acids were similar to one another, with IPPA being the lowest (gonads 15 Gy/MBq, heart wall 18 Gy/MBq). Doses for Tc-99m PYP were also low (gonads 4-7 Gy/MBq, heart wall 4 Gy/MBq, skeleton 15 Gy/MBq). The desirability of these compounds is discussed briefly, considering half-life, imaging mode and energy, and dosimetry, including a comparison of the effective whole body dose equivalents. 37 references, 11 tables

  11. Strong ionisation in carbon nanowires

    Science.gov (United States)

    Kaymak, V.; Pukhov, A.; Shlyaptsev, V. N.; Rocca, J. J.

    2016-04-01

    Surfaces covered with nanostructures, such as nanowire arrays, are shown to facilitate a significantly higher absorption of laser energy as compared to flat surfaces. Due to the efficient coupling of the laser energy, highly energetic electrons are produced, which in turn can emit intense ultrafast X-ray pulses. Full three dimensional PIC simulations are used to analyse the behaviour of arrays of carbon nanowires 400 nm in diameter, irradiated by a 400-nm laser pulse of 60-fs duration at FWHM and a vector potential of α0 = 18. We analyse the ionisation dynamics of the nanowires. The difference of the ionisation strength and structure between linearly and circularly polarised laser beam is investigated. The nanowires are found to be fully ionised after about 30 laser cycles. Circularly polarised light reveals a slightly stronger ionisation effect.

  12. Degradation products of benzyldibutylamine as extraction agent

    International Nuclear Information System (INIS)

    The composition of the degradation products of benzyldibutylamine (BDBuN) and benzene radiolysis in the presence of nitric acid and lanthanide nitrates was identified by means of mass, NMR and infrared spectra, elementary analysis and gas liquid chromatography. The change in the extraction capacity of this agent and its solutions in aromatic hydrocarbon solvents in the extraction of Eu/III/ and Am/III/ was investigated in dependence on the absorbed dose of the ionising radiation. (author)

  13. Degradation products of benzyldibutylamine as extracton agent

    Science.gov (United States)

    Mirchi, R.; Jedinakova, V.

    The composition of the degradation products of benzyldibutylamine (BDBuN) and benzene radiolysis in the presence of nitric acid and lanthanide nitrates was identified by means of mass, NMR and infrared spectra, elementary analysis and gas liquid chromatography. The change in the extraction capacity of this agent and its solutions in aromatic hydrocarbon solvents in the extraction of Eu/III/ and Am/III/ was investigated in dependence on the absorbed dose of the ionising radiation.

  14. Synthesis and evaluation of new protecting agents against ionizing radiations

    International Nuclear Information System (INIS)

    This thesis is devoted to the synthesis of new pulvinic acid derivatives and the evaluation of their antioxidant and radioprotective properties. This study has been conducted with the aim to develop new protecting agents against ionizing radiations. A new access to pulvinic acid derivatives was developed starting from L-dimethyl tartrate. It is based on a Dieckmann cyclization a dehydration and a Suzuki-Miyaura coupling. It allows a short effective preparation of various pulvinic acid derivatives: tetronic acid derivatives, mono-substituted pulvinic acid derivatives and methyl pulvinates. A modified method has been used to prepare pulvinones. This strategy gave access in four steps to the desired pulvinones. The rapidity of this method is provided by a tandem process, carried out in the final step, involving a Dieckmann cyclization and a β-elimination. A synthesis of 3-aryltetramic acids has also been developed in order to prepare nitrogen derivatives of pulvinic acid. The antioxidant activity of the prepared compounds was then evaluated using various tests: DPPH, ABTS, protection of thymidine and DNA study of lipid peroxidation. These evaluations allowed to define interesting structure-activity relationships of pulvinic derivatives. They have shown that several derivatives have very good antioxidant activities. Finally, radioprotective tests on TK6 cells and mice have have been performed on selected compounds. (author)

  15. Efficacy of agents counteracting hypoxia in fractionated radiation regimes

    International Nuclear Information System (INIS)

    Background and purpose: Solid tumours contain hypoxic cells which are resistant to radiotherapy. This study compares the efficacy of several strategies to counteract diffusion-limited hypoxia, or intermittent hypoxia in a fractionated regimen of 1 to 6 x 2 Gy. Materials and methods: Nicotinamide (250 mg/kg), perflubron emulsion (OxygentTM) (4 ml/kg), tirapazamine (SR4233) (0.10 mmol/kg) and carbogen breathing, administered alone or in combination, were investigated on two tumour cell lines: EMT6 (a rodent mammary carcinoma) and HRT18 (a human rectal adenocarcinoma) using a clonogenic assay. The radiosensitizing effect of the agents was assessed after 1 and 6 x 2 Gy for drugs used alone, and 1, 2, 4, 6 x 2 Gy for drugs used in combination. Results: At the end of the fractionated radiation regimen, the combination of nicotinamide + carbogen induced the greatest radiosensitization for EMT6 tumours, while greatest radiosensitization of HRT18 was obtained with nicotinamide + carbogen + tirapazamine. Conclusion: The efficacy of the strategies for overcoming hypoxia using a fractionated regimen depends on the tumour cell line. These differences could be linked to differences in the initial percentages of acute and chronic hypoxic cells, and to changes in the two types of hypoxia during treatment

  16. About the contribution of occupational health's services for risk factors evaluation, medical and dosimetric follow-up in the workers monitoring exposed to ionising radiations in France

    Energy Technology Data Exchange (ETDEWEB)

    Bailloeuil, C.; Gonin, M.; Gerondal, M. [Gaz de France (EDF/GDF), 75 - Paris (France)

    2006-07-01

    Full text of publication follows: French national regulation (31/03/2003) indicates principles of a global approach about the medical and dosimetric follow-up in the workers monitoring. Legislator insists on risks and expositions trace ability along all professional career and after. The aim of this French specific system is to institute medical clinic aspects in accordance with dosimetry and professional risks. The occupational practitioners are approved practitioners who have followed a specific training. The organisation guarantees that a worker will be followed by one specific practitioner in order to reinforce the quality and the traceability of follow up. Medical supervision is done at taking on and at least once a year. It means to identify and take care of risks and expositions at work stations. If necessary, biological measurements and recommendations about collective and individual protection equipments complete the estimation of risks. On the subject of emergency, first aid is delivered on sites by occupational health personnel, either for classic medical problem or for radiological accident. Furthermore, occupational health personnel assist outside emergency services with whom we have specific conventions. External dosimetric follow-up is done with radiation protection qualified expert of the company. The internal contamination supervision and internal dose evaluation are done by the occupational health services. Measurements either whole body counts or radio-toxicologic analysis are submitted to technical quality process. Beyond the respect of regulatory dose limits, the aim of the dosimetric follow-up is the contribution to the preparation of work places with strong dosimetric focus. Informations at workers are dispensed about every risks and every kinds of risks: ionising radiation health effects, ionising radiation and pregnancy, high exposition, chemical risks, work at heat, asbestos. All data are conserved 50 years after the exposure These data

  17. Mouse Models for Efficacy Testing of Agents against Radiation Carcinogenesis—A Literature Review

    OpenAIRE

    Leena Rivina; Robert Schiestl

    2012-01-01

    As the number of cancer survivors treated with radiation as a part of their therapy regimen is constantly increasing, so is concern about radiation-induced cancers. This increases the need for therapeutic and mitigating agents against secondary neoplasias. Development and efficacy testing of these agents requires not only extensive in vitro assessment, but also a set of reliable animal models of radiation-induced carcinogenesis. The laboratory mouse (Mus musculus) remains one of the best anim...

  18. Significance of stable and unstable cytogenetic biomarkers in estimation of genome damage in subjects exposed to physical and chemical agents

    International Nuclear Information System (INIS)

    The last few years have shown that cytogenetic biomarkers do predict increased cancer risk. The most frequently used biomarkers in genetic toxicology are chromosome aberration assay (CA) and micronucleus (MN) assay. Fluorescent in situ hybridisation (FISH), in turn, enables analysis of translocation as a stable genome damage. With technological development, working environment has become associated with complex exposure to ionising and non-ionising radiation and chemical agents. A follow-up of 1200 subjects occupationally exposed to ionising radiation and chemical agents using CA and MN showed that the highest deviations from control values were detected in complex exposure to ionising radiation and ultrasound or to radioisotopes in medicine and in industrial radiography and to ionising radiation in specific jobs in nuclear plants. FISH used in a group of subjects exposed to gamma radiation and ultrasound showed that translocation frequency could rise even when CA frequency is within control values. This example shows that health risk is present even when results obtained by routine methods for the last few decades do not deviate from control values and that a decrease in permissible doses does not protect from accumulated genome damage during employment under different conditions. As biological effects of complex exposure are not possible to monitor by physical measurements, cytogenetic biomarkers are the only reliable tools to evaluate of genome damage and significant parameters in regulating health surveillance of exposed subjects.(author)

  19. Prevention of risks in relation with occupational exposure to ionizing radiation; Prevention des risques lies a l'exposition professionnelle aux rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    After remind the base notions in the field of ionizing radiation, this file evaluates the situation on the natural and occupational exposures: modes, sources, and exposure level, risk for health. It presents the principles of prevention allowing in a professional area (out of nuclear industry) to reduce and control these exposures. Some practical cases illustrate the radiation protection approach. references are given: regulatory benchmarks, useful links, books to consult. (N.C.)

  20. Low doses ionising radiation: - the scientific controversy about the effects; - opinions of some persons involved in medical X-ray diagnostics

    International Nuclear Information System (INIS)

    After an introduction on biological radiation effects, different dose concepts, dose-response relationships, standards for radiation hygiene and legal regulations for radiation protection, the authors try to make explicit what is missing in the way of knowledge, research data and analytical or statistical methods leading to the so called BEIR-III controversy. Comparisons are drawn up between the BEIR-III report, articles by Rossi, Radford and Fabrikant, the Hanford investigations, the Three State Investigation, and research by Bertell and Bross. Causes of the controversy are found to be the difference in risk estimation methods, interpretation differences, non-scientific motivations for not accepting or overstressing the importance of presented data. In the next chapters the radiation burden due to medical X-ray radiography in the Netherlands is compiled with help of data from hospitals, population screening projects, and medical registrations. Critical remarks by experts in the field of radiology are presented in full. The last chapter contains a recommendation for lowering the population radiation burden due to medical applications and various means to achieve this. (Auth.)

  1. Ionizing radiation M.O.S. dosimeters: sensibility and stability; Dosimetres M.O.S. de rayonnements ionisants: sensibilite et stabilite

    Energy Technology Data Exchange (ETDEWEB)

    Gessinn, F.

    1993-12-01

    This thesis is a contribution to the study of the ionizing radiation responsivity of P.O.M.S. dosimeters. Unlike the development of processing hardening techniques, our works goal were to increase, on the one hand, the M.O.S. dosimeters sensitivity in order to detect small radiation doses and on the other hand, the stability with time and temperature of the devices, to minimize the absorbed-dose estimation errors. With this aim in mind, an analysis of all processing parameters has been carried out: the M.O.S. dosimeter sensitivity is primarily controlled by the gate oxide thickness and the irradiation electric field. Thus, P.M.O.S. transistors with 1 and 2 {mu}m thick silica layers have been fabricated for our experiments. The radiation response of our devices in the high-field mode satisfactorily fits a D{sub ox}{sup 2} power law. The maximum sensitivity achieved (9,2 V/Gy for 2{mu}m devices) is close to the ideal value obtained when considering only an unitary carrier-trapping level, and allows to measure about 10{sup -2} Gy radiation doses. Read-time stability has been evaluated under bias-temperature stress conditions: experiments underscore slow fading, corresponding to 10{sup -3} Gy/h. The temperature response has also been studied: the analytical model we have developed predicts M.O.S. transistors threshold voltage variations over the military specifications range [-50 deg. C, + 150 deg. C]. Finally, we have investigated the possibilities of irradiated dosimeters thermal annealing for reusing. It appears clearly that radiation-induced damage annealing is strongly gate bias dependent. Furthermore, dosimeters radiation sensitivity seems not to be affected by successive annealings. (author). 146 refs., 58 figs., 9 tabs.

  2. Interaction of Radiation Therapy With Molecular Targeted Agents

    OpenAIRE

    Morris, Zachary S.; Harari, Paul M.

    2014-01-01

    The development of molecular targeted therapeutics in oncology builds on many years of scientific investigation into the cellular mechanics of malignant transformation and progression. The past two decades have brought an accelerating pace to the clinical investigation of new molecular targeted agents, particularly in the setting of metastatic disease. The integration of molecular targeted agents into phase III clinical trial design has lagged in the curative treatment setting, particularly i...

  3. Radiation hardenable impregnating agents for the consolidating conservation of wooden objects

    International Nuclear Information System (INIS)

    Radiation hardenable impregnating agents offer some advantages over the conventional agents. At the author's institution objects up to 110 cm length can be impregnated for conservation. More than 200 monomers and resins have been investigated. The procedure of impregnation is outlined and some kinds of wooden objects conserved in this way listed. (G.W.)

  4. Accelerated induction of skin cancers by ultraviolet radiation in hairless mice treated with immunosuppressive agents

    International Nuclear Information System (INIS)

    An increased incidence of cancer is well recognized in organ transplant recipients treated with immunosuppressive agents. Skin cancers are the most common lesions encountered. To investigate a possible relationship between the immunosuppressive agents and ultraviolet radiation (UVR), several groups of hairless mice were treated with ultraviolet light, azathioprine, or prednisone, or the three in various combination. The two latter drugs are the immunosuppressive agents most frequently used in organ transplant recipients

  5. Accelerated induction of skin cancers by ultraviolet radiation in hairless mice treated with immunosuppressive agents

    Energy Technology Data Exchange (ETDEWEB)

    Koranda, F.C.; Loeffler, R.T.; Koranda, D.M.; Penn, I.

    1975-01-01

    An increased incidence of cancer is well recognized in organ transplant recipients treated with immunosuppressive agents. Skin cancers are the most common lesions encountered. To investigate a possible relationship between the immunosuppressive agents and ultraviolet radiation (UVR), several groups of hairless mice were treated with ultraviolet light, azathioprine, or prednisone, or the three in various combination. The two latter drugs are the immunosuppressive agents most frequently used in organ transplant recipients.

  6. Plane electrode device for multiwire detector for ionizing radiations. Dispositif d'electrodes planes pour multidetecteur de rayons ionisants et procede pour realiser un tel dispositif

    Energy Technology Data Exchange (ETDEWEB)

    Tirelli, M.; Hecquet, R.

    1988-01-08

    A multiwire proportional counter type detector with thin slits instead of wires is presented. It can detect either charged particles (positive or negative) or radiation. The detector can be used as a counter or as an image converter. In radiography, it can replace photographic film or TV camera systems. It can also be used to measure particle or radiation energy. The slits which replace wires in the anode are introduced between two parallel microstrip conductors with different potentials. A quasi-polar electric field is produced between these strips. To obtain high fields, the slits are extremely narrow. Microstrips less than a micron can be obtained, giving structural dimensions of a few microns, i.e., 100 times smaller than the spacing in a classic wire anode.

  7. The ENEA calibration service for ionising radiations. Part 1: Photons; Il centro di taratura per la radiazioni ionizzanti di Bologna. Parte 1: Fotoni

    Energy Technology Data Exchange (ETDEWEB)

    Monteventi, F.; Sermenghi, I. [ENEA Centro Ricerche Ezio Clementel, Bologna (Italy). Dipt. Ambiente

    1999-07-01

    The ENEA (National Agency for New Technology, Energy and the Environment) calibration service for ionizing radiations has been active for 40 years in the secondary standard dosimetry laboratory web. It has been the first center, in 1985, to be acknowledges by the Italian calibration service (SIT) for the two quantities for photons: exposure and air kerma. Since the Institute for the Radiation Protection of ENEA has moved to the new site in Montecuccolino (Bologna, Italy) in 1995, the whole laboratory has been renovated and all irradiation rooms together with radiation source and equipment have been reorganized according to the {chi}, {gamma}, {beta} and neutron fields metrology requirements. The aim of this report, as the first part of a report describing all facilities available at the service, is to give a detailed description of all equipment s qualified for photon fields metrology including the secondary standards and the calibration procedures performed for radiation monitoring devices and dosemeters. [Italian] Il centro di taratura dell'ENEA di Bologna opera nel campo della metrologia secpndaria da quasi 40 anni ed e' stato il primo centro nel 1985 ad essere riconosciuto dal SIT (Servizio di Taratura in Italia) per le grandezze esposizione e Kerma in aria. Con l'insediamento di tutto l'Istituto per la Radioprotezione nella nuova sede di Montecuccolino sono state ricostruite e riorganizzate anche tutte le sale di irraggiamento e tutti gli impianti radiogeni a disposizione per la metrologia delle radiazioni X, gamma, beta e neutroni. Intenzione di questo primo rapporto e' descrivere le attrezzature qualificate per la metrologia fotonica, dei campioni di misura e delle procedure adottate per la taratura degli strumenti e dei dosimetri.

  8. Reinforce the radiation protection of the health personnel, patients and public; Renforcer la protection contre les rayonnements ionisants. Des professionnels de sante, des patients et du public

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-03-01

    One of the missions of the IRSN is the public radiation protection. In this context and in order to inform the public, this press document presents the actions of the IRSN in the occupational safety, the patients and the public, with a special interest to the Chernobyl accident consequences in France. The prevention policy against the radon, implemented by the Institute is also presented. (A.L.B.)

  9. What impact does ionising radiation have on humans and the environment? Use of SCK-CEN biosphere models in international studies

    International Nuclear Information System (INIS)

    Certain nuclear activities may have an impact on man and the environment. To understand the precise magnitude of the effect, one must first understand the distribution and behaviour of radioactive substances in the environment. This knowledge is also necessary in order to take appropriate measures to reduce radiation exposure. analysing the environmental effects of MYRRHA and of waste disposal facilities are just some of the applications of SCK-CEN biosphere impact studies.

  10. Comprehensive data on ionising radiation from Fukushima Daiichi nuclear power plant in the town of Miharu, Fukushima prefecture: The Misho Project

    International Nuclear Information System (INIS)

    Data related to radioactivity released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 15 March 2011 gathered by residents of Miharu, Fukushima Prefecture, and by Tohoku University are presented. These data sets consist of (1) the earliest radiation monitoring by a Geiger counter in the town, (2) ratios of radioactivity between 132Te and 137Cs for a wide area between Fukushima and Tokyo, (3) radiation measurement of soil samples collected from 18 school grounds, and (4) external radiation exposure of 1400 students using OSL badges. By combining and analysing these various data sets, a curve for the cumulative total external exposure as a function of time, with 16 : 00 h on 15 March 2011 being time zero, is obtained. The average cumulative external dosage is estimated to be 10 mSv (σ = 4.2 mSv) over 10 years. In addition, the initiative that the residents of Miharu took in response to the FDNPP accident, which became known as The Misho Project (MP), is documented; in particular, the time at which the municipality instructed the immediate ingestion of iodine tablets by those under the age of 40, 13 : 00 h on 15 March 2011, is assessed. (paper)

  11. Histopathology as biomarkers: in treated mouse brain with radiation, cadmium and therapeutic agents (Aloe Vera)

    International Nuclear Information System (INIS)

    There are two different types of radiation energetic particles and electromagnetic waves. These two types can penetrate into living tissue or cell and result in transduction of radiation energy to biological materials. The absorbed energy of ionising radiation can break chemical bonds and cause ionization of different molecules including water and different biological essential macromolecules of as DNA, membrane lipids and protein. Many types of DNA lesions are produce in cell by ionizing radiation and chemicals during cancer therapy. Cadmium is known to deplete glutathione and protein bounds sulfhydrl groups which results in enhance production of reactive oxygen species (ROS). The reactions of these ROS with cellular biomolecules have been shown to lead to lipid per-oxidation. Aloe vera is dietary antioxidant that plays an important role in controlling oxidative stress. For this purpose, six to eight weeks old male Swiss albino mice (Mus musculus) were randomly divided into seven groups. On the basis of radiation, cadmium, combined treatment and Aloe treated groups the animals were sacrificed at each post treatment intervals of 1, 2, 4, 7, 14 and 28 days. The brain were taken out and weighed to the analytical balance and fixed for 24 hours in alcoholic Bouin's fixative. A pinch of lithium carbonate was added to remove excess picric acid in the fixative. Histological studies were carried out using the standard techniques of haematoxyline and eosin staining. After combined treatment of radiation and cadmium chloride synergistic changes were observed. These changes were less severe in the Aloe vera treated brain which may be due to the protection provided by drug

  12. Synergism in mutations induction in Tradescantia by plants protection agents acting jointly with ionizing radiation

    International Nuclear Information System (INIS)

    Tradescantia was first treated by plants protection agents such as: Ambusz, Afalton, Ripcord, Decis, deltametryne and after that irradiated with X radiation. The synergism of both factors was observed. The mutation frequency dependence on radiation doses was studied. 7 figs., 4 refs. (A.S.)

  13. Epidemiological studies of Fukushima residents exposed to ionising radiation from the Fukushima Daiichi Nuclear Power Plant prefecture—a preliminary review of current plans

    International Nuclear Information System (INIS)

    It is now more than six months since the beginning of the accident on 11 March 2011 at the Fukushima Daiichi Nuclear Power Plant in Japan. The Japanese government and local health authorities have started to collect the information necessary to estimate radiation doses received by those living in the area around the plant, drafted plans for the health care of residents, and started to implement some of them. This paper reviews and discusses the studies necessary for risk evaluation of cancer and non-cancer diseases, including those already planned, mainly from the view point of evaluating health risk using epidemiological approaches. In the long run, it is important to establish a cohort with a control group. Even if the cumulative doses are estimated to be so low that it is difficult to evaluate the risk of cancer and non-cancer diseases, it is necessary to conduct such a study to reassure residents. The health care programme of the Fukushima Prefecture government, including health check-ups of residents, will help to assess indirect effects of radiation exposure, including psychological problems. The success of any studies of radiation epidemiology depends on the collection of accurate information on radiation doses received by the study subjects. However, some of the dosimetry surveys were not conducted in a timely manner. (It should be recognised, though, that such a problem might have been inevitable, considering the chaotic condition after the nuclear accident.) Accurate estimation of the radiation dose received by each resident is not only important for scientific risk evaluation but also to inform each resident about his or her potential risk. Otherwise, residents will bear an undue psychological burden from uncertainties regarding their radiation exposure and its health consequences. One of other important tasks in Fukushima is the improvement of the quality of the regional cancer registry in this prefecture. It is also important to start thyroid cancer

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

    International Nuclear Information System (INIS)

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

  15. Manufacturing process for electrodes for ionizing radiation detectors. Procede de fabrication d'une electrode pour detecteur de rayons ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Tirelli, M.G.; Hecquet, R.

    1987-12-24

    A manufacturing proces for electrodes for ionizing radiation detectors, particularly electrodes for X-ray multidetectors, is proposed. It consists of electrodepositing at least one layer of an electrically conducting material on at least one side of a relatively flat plate. A ductile material is used to form the conducting layer. The assembly formed by the plate covered by the ductile conducting material is subjected to pressing to crush the ductile conducting material at least in the zones where the assembly formed by the plate and the covering material has a total thickness superior to a constant thickness desired for the electrode.

  16. Characterization and pharmacological modulation of intestinal inflammation induced by ionizing radiation; Caracterisation et modulation pharmacologique de l'inflammation intestinale induite par les rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    Gremy, O

    2006-12-15

    The use of radiation therapy to treat abdominal and pelvic malignancies inevitably involves exposure of healthy intestinal tissues which are very radiosensitive. As a result, most patients experience symptoms such as abdominal pain, nausea and diarrhea. Such symptoms are associated with acute damage to intestine mucosa including radio-induced inflammatory processes. With a rat model of colorectal fractionated radiation, we have shown a gradual development of a colonic inflammation during radiation planning, without evident tissue injury. This radio-induced inflammation is characterized not only by the sur expressions of pro-inflammatory cytokines and chemokines, a NF-kB activation, but also by a repression of anti-inflammatory cytokines and the nuclear receptors PPARa and RXRa, both involved in inflammation control. This early inflammation is associated with a discreet neutrophil recruitment and a macrophage accumulation. Macrophages are still abnormally numerous in tissue 27 weeks after the last day of irradiation. Inflammatory process is the most often related to a specific immune profile, either a type Th1 leading to a cellular immune response, or a type Th2 for humoral immunity. According to our studies, a unique abdominal radiation in the rat induces an ileum inflammation and an immune imbalance resulting in a Th2-type profile. Inhibiting this profile is important as its persistence promotes chronic inflammation, predisposition to bacterial infections and fibrosis which is the main delayed side-effect of radiotherapy. The treatment of rats with an immuno-modulator compound, the caffeic acid phenethyl ester (C.A.P.E.), have the potential to both reduce ileal mucosal inflammation and inhibit the radio-induced Th2 status. In order to search new therapeutic molecular target, we has been interested in the PPARg nuclear receptor involved in the maintenance of colon mucosal integrity. In our abdominal irradiation model, we have demonstrated that the prophylactic

  17. A comparative study of the effect of low doses of ionising radiation on primary cultures from rainbow trout, Oncorhynchus mykiss, and Dublin Bay prawn, Nephrops norvegicus

    International Nuclear Information System (INIS)

    There have been very few studies on comparative radiobiology. Any work that has been done has involved very high doses which are not relevant for environmental exposures. The aim of the present study was to compare the effects of radiation on primary cultures from both rainbow trout and Dublin Bay prawn, Nephrops norvegicus. Primary cultures from the pronephros of rainbow trout and from the haematopoietic tissue of Nephrops norvegicus were irradiated in situ 2-4 days after explantation using a 60Co teletherapy unit. The doses used were 0.5 and 5 Gy. The cultures were fixed 4-7 days post irradiation in 2.5% glutaraldehyde, post fixed in 1% OsO4, dehydrated in ascending grades of ethanol and embedded in epoxy resin. Thin sections were cut en face from the embedded cultures, stained with uranyl acetate and lead citrate and examined using a JEOL 2000 transmission electron microscope. The irradiated cultures from both rainbow trout and Nephrops norvegicus displayed pronounced morphological damage, in particular to the nucleus and mitochondria. Damage to the cytoskeleton was also evident. However, cells from the haematopoietic tissue of Nephrops norvegicus appeared to be considerably more radiosensitive than cells from the pronephros of rainbow trout. These results may have important implications for environmental radiation protection policies. (author)

  18. ARPANSA's regulatory role in the protection of the environment from ionising radiation. Licensing the remediation of abandoned uranium mine workings in Kakadu National Park

    International Nuclear Information System (INIS)

    ARPANSA was established by the Australian Radiation Protection and Nuclear Safety Act 1998 to perform a number of specific functions including the licensing of those activities involving radioactive material that are undertaken by Commonwealth entities. This paper describes the role of the regulator in the rehabilitation of an area of Kakadu National Park, which has been licensed as a Prescribed Radiation Facility. When making a decision on whether to issue a licence, the CEO of ARPANSA is obliged by the ARPANS Act to consider, inter alia, whether it has been established that the proposed conduct can be carried on without undue risk to the health and safety of people, and to the environment. However, when licensing the remediation of environmental and radiological consequences of mining activities special difficulties may arise in determining the regulatory approach to be adopted with regard to an intervention of this nature. One specific example is the limited internationally accepted objective radiological criteria on which to base regulation of any remediation. In the particular case of an intervention in Kakadu National Park, the multiplicity of interest groups directly or indirectly involved in management of the affairs of this world heritage listed area adds an extra element to the regulatory equation. (author)

  19. 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)

    Over several decades, modelling the effects of ionizing radiation on biological system has relied on the target principle [Timofeeff-Ressovsky et al., 1935], which assumes that cell damage or modification to genes appear as a direct consequence of the exposure of biological macromolecules to charged particles. Furthermore, it is assumed that there is no threshold for the induction of biological damage and that the effects observed are proportional to the energy absorbed. Following this principle, the average number of hits per target should increase linearly with dose, and the yield of mutations per unit of dose is assumed to be the same at both low and high doses (linearity of response). This principle has served as the scientific background for the linear no-threshold (LNT) concept that forms the basis for the radiological protection for the public and the environment [ICRP, 1990]. It follows from the LNT that there is an additional risk for human health from exposure to any radiation level, even below natural background. Since the mid 50's, however, the scientific basis for the LNT concept has been challenged as experimental data have shown that, at low doses, there was a non linear relationship in the dose response. Luchnik and Timofeeff-Ressovsky were the first who showed a non-linear response to a low dose exposure [Luchnik, 1957; Timofeeff-Ressovsky and Luchnik, 1960]. Since then, many data have been accumulated which contradict the LNT model at low doses and dose rates. However, the hit-effect paradigm has become such a strong and indissoluble fact that it has persisted even under the growing pressure of scientific evidence for phenomena at low dose exposure that can not be successfully accounted for by the LNT concept. In recent years, additional information on non-targeted effects of radiation has been accumulated following the first reports of an adaptive response in human lymphocytes [Olivieri et al., 1984] as well as bystander mutagenic effect of alpha

  20. 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

    Over several decades, modelling the effects of ionizing radiation on biological system has relied on the target principle [Timofeeff-Ressovsky et al., 1935], which assumes that cell damage or modification to genes appear as a direct consequence of the exposure of biological macromolecules to charged particles. Furthermore, it is assumed that there is no threshold for the induction of biological damage and that the effects observed are proportional to the energy absorbed. Following this principle, the average number of hits per target should increase linearly with dose, and the yield of mutations per unit of dose is assumed to be the same at both low and high doses (linearity of response). This principle has served as the scientific background for the linear no-threshold (LNT) concept that forms the basis for the radiological protection for the public and the environment [ICRP, 1990]. It follows from the LNT that there is an additional risk for human health from exposure to any radiation level, even below natural background. Since the mid 50's, however, the scientific basis for the LNT concept has been challenged as experimental data have shown that, at low doses, there was a non linear relationship in the dose response. Luchnik and Timofeeff-Ressovsky were the first who showed a non-linear response to a low dose exposure [Luchnik, 1957; Timofeeff-Ressovsky and Luchnik, 1960]. Since then, many data have been accumulated which contradict the LNT model at low doses and dose rates. However, the hit-effect paradigm has become such a strong and indissoluble fact that it has persisted even under the growing pressure of scientific evidence for phenomena at low dose exposure that can not be successfully accounted for by the LNT concept. In recent years, additional information on non-targeted effects of radiation has been accumulated following the first reports of an adaptive response in human lymphocytes [Olivieri et al., 1984] as well as bystander mutagenic effect of

  1. A legal analysis of the use of ionising radiation in medical hospital practice: an inquiry into the influence of prevention and precaution on health protection and liability. Doctoral thesis prepared at SCK-CEN and defended in 2004

    International Nuclear Information System (INIS)

    The article refers to an abstract of a doctoral thesis. From a legal perspective there exists a clear need for a general framework describing conditions and consequences of risk management in the field of high technology. Despite the existence of many kinds of Safety Procedures and Soft Law, specific guidelines are lacking for regulators and courts, especially in case of scientific controversy and uncertainty about the health effects of an activity or a product such as low doses of ionising radiation, electro-magnetic fields, genetically modified organisms, PCB's in salmon etc. The research of the PISA Project on Legal Aspects and Liability has been focussed on the medical applications of ionising radiation. The safety approach depends on the risk characterisation and differs for stochastic and deterministic effects. The most important objective was to find liability or funding systems which can cope with these differences, in particular between dose limits (as for the nuclear industry), reference dose levels foreseen in the EC medical Directive (as for nuclear medicine), and Optimisation referring to the ALARA principle. Risk assessment and risk management that are based on traditional narrow risk-assessment models have to be revised in the light of the Precautionary Principle. This principle urges policy-makers to adopt a broader, more pluralistic approach, considering the societal equilibrium, i.e. the general interest of the activity at stake, the general impact of individual protective measures and the existence of reasonable alternatives from a sociological, economical, scientific and technological point of view. One of the characteristics of the Precautionary Principle relates to our opinion to the collective damage to human health, i.e. a detriment that relates to a group of people. Nevertheless, as a result of the application of the Precautionary Principle, we believe that in case of individual damage the standard of care shall be more and more defined

  2. Cytogenetic effect of low dose radiation and contrast agent

    International Nuclear Information System (INIS)

    The effect of the X-ray contrast medium Amidotrizoate on radiation-induced chromosomal damage was investigated in peripheral human lymphocytes, in vitro. The blood undergoes treatment in one of three ways: 1) Amidotriozate alone at concentrations 1, 3 and 5%; 2) X-irradiation alone at dose 0,2 Gy; 3) X-irradiation in the presence of the contrast medium. Given alone Amidotrisoate was not effective in producing chromosomal aberrations. The cytogenetic effect of 0,2 Gy X-ray was statistically significant. The presence of Amidotrisoate during irradiation potentiates radiation-induced chromosomal damage depending on the concentration used. (author)

  3. About the interest of a space of dialogue and exchange between occupational health services of the European Union involved in the monitoring of workers exposed to ionising radiations

    International Nuclear Information System (INIS)

    The members states of union have in common the Community directives, transposed by each country in their national legislations.In practice organizations, and even regulations are different from one country to another for more historical and cultural reasons than strictly technical ones. Common objectives and necessity of exchange appeared more strongly because of increase mobility of exposed workers in the European Union and the necessity to facilitate their entry in the European nuclear power plant s respecting quality of medical and dosimetric follow-up, the promotion of the creation of an European worker passport, the strict respect of the European regulations, the necessity of common references for crisis trans-bordering radiological injured persons, the interest of exchanges about good medical or technical practices or specific knowledge's in subject such as therapeutic and follow-up, internal contamination, skin dose..., the interest of exchanges about the technical quality process in laboratories or occupational health services. This group could be integrated in radiation protection society of each country for example. this group will be able to exchange by meetings, technical groups, publications, specific workshops. The different country actually represented are France, Belgium, Germany, Italy, Luxembourg, Spain. (N.C.)

  4. Analysis of the Relation Between Exposure to Ionising Radiation from Computed Tomography Scans in Childhood and Cancer Incidence within the 'Cohorte Enfant Scanner' Study

    International Nuclear Information System (INIS)

    Computed tomography (CT) is a powerful imaging technique that provides great benefits for diagnosis and medical management of patients. Nonetheless, the widespread use of this procedure raises many concerns about the potential adverse effects induced by X-rays exposure, both in clinical practice and in terms of public health. First epidemiological studies have suggested an increased risk of cancer associated with CT scan exposures in childhood or adolescence. The interpretation of these results is, however, controversial, and evidence about radiation-induced risks of cancer is still limited at this level of exposure and during childhood. In France, the 'Enfant Scanner' cohort was set up by IRSN to study the incidence of cancer among more than 100,000 children who received CT scans before the age of 10 in 21 university hospitals. This study is part of the European Epi-CT project - coordinated by the International Agency for Research on Cancer - which includes nine national cohorts set up on the basis of a common protocol. The current thesis, based on the French cohort, focuses on characterizing the exposure of children receiving diagnostic CT scans and quantifying the risk of cancer associated with these exposures. Dosimetric assessment was performed from the radiological protocols used in paediatrics between 2000 and 2011 in the participating hospitals. This study presents the evolution of the exposures during the period and the variability of practices in the radiology departments. The results show that there is a leeway for optimizing the procedures and limiting the exposure of patients, especially for scans of the head that account for most of the examinations in paediatrics. A quantitative assessment of cancer risk potentially induced by CT scans in paediatrics was performed - on the basis of estimates of risk in other contexts of ionizing radiation exposure. The results show that each CT scan could be associated with an excess risk of tumours of the

  5. Vitamin C acts as radiation-protecting agent

    International Nuclear Information System (INIS)

    It is well known that vitamin C (L-ascorbic acid) is a very efficient, water soluble antioxidant. Its multifunctional biological and biochemical activities are rather well established in the last few decades (e.g. Sies and Stahl, 1995; Meydani et al., 1995; NRC, 1989. In the present letter we are reporting briefly the pronounced radiation-protecting properties of ascorbate (AH-) observed on bacteria (E. coli AB1157) as well as on cultured cells (SCC VII, eukaryotic cells)

  6. In-vivo models for radiation mitigator agents

    International Nuclear Information System (INIS)

    The US Department of Health and Human Services assigned the National Institute of Allergy and Infectious Diseases (NIAID), National Institute of Health (NIH), with the responsibility to identify, characterize and develop new medical countermeasure (MCM) products against radiological and nuclear attacks that may cause-a public health emergency. MCMs must be developed within the criteria of the U.S. Food and Drug Administration's (FDA) 'animal rule' (AR) which requires the design and conduct of validated animal models to define the major sequelae of the Acute Radiation Syndrome (ARS) and Delayed Effects of Acute Radiation Exposure (DEARE). To this end, the NIAID-funded Product Development Support Services Program has established an ARS/DEARE animal model research platform which includes several basic animal models for hematopoietic and gastrointestinal ARS in the mouse and nonhuman primate (NHP) using total-body irradiation (TBI), whole-thorax lung irradiation (WTLI), or a multi-organ dysfunction model defined by partial-body irradiation with 5% bone marrow sparing (PBI/ BM5). These specific models will be discussed as well as ongoing observational studies NIAID is funding to assess the long-term effects of radiation in NHPs and A-Bomb survivors. (author)

  7. Radiation-curable impregnating agents for the conservation of archaeologic wooden objects. Part 2

    International Nuclear Information System (INIS)

    As a continuation of the work described in OEFZS Ber. No. 4165, impregnating agents curable by ionizing radiation, such as free radical polymerizable monomers or artificial resins, have been investigated. Specific weight and viscosity of the liquid mixtures have been as well determined as the specific weight and gel content of the gamma radiation-cured samples. Hardness and elastic behaviour have been estimated only. The shrinkage during hardening was found to be 5 to 12 % for low viscous mixtures (up to 600 mPa.s) and 3 to 8 % for higher viscous impregnating agents. The results are to be discussed. (Author)

  8. Mouse Models for Efficacy Testing of Agents against Radiation Carcinogenesis — A Literature Review

    Directory of Open Access Journals (Sweden)

    Leena Rivina

    2012-12-01

    Full Text Available As the number of cancer survivors treated with radiation as a part of their therapy regimen is constantly increasing, so is concern about radiation-induced cancers. This increases the need for therapeutic and mitigating agents against secondary neoplasias. Development and efficacy testing of these agents requires not only extensive in vitro assessment, but also a set of reliable animal models of radiation-induced carcinogenesis. The laboratory mouse (Mus musculus remains one of the best animal model systems for cancer research due to its molecular and physiological similarities to man, small size, ease of breeding in captivity and a fully sequenced genome. This work reviews relevant M. musculus inbred and F1 hybrid animal models and methodologies of induction of radiation-induced leukemia, thymic lymphoma, breast, and lung cancer in these models. Where available, the associated molecular pathologies are also included.

  9. Simulation studies on a prototype ionisation chamber for measurement of personal dose equivalent, Hp(10)

    International Nuclear Information System (INIS)

    A prototype ionisation chamber for direct measurement of the personal dose equivalent, Hp(10), similar to the one developed by the Physikalisch-Technische Bundesantalt (PTB), was designed and constructed by the Metrological Laboratory of Ionizing Radiation (LMRI) of Nuclear and Technological Inst. (ITN). Tests already performed have shown that the behaviour of this chamber is very similar to the PTB chamber, mainly the energy dependence for the X-ray radiation qualities of the ISO 4037-1 narrow series N-30, N-40, N-60, N-80, N-100 and N-120 and also for gamma radiation of 137Cs and 60Co. However, the results obtained also show a dependence on the energy and angles of incident radiation and a low magnitude of the electrical response of the ionisation chamber. In order to optimise the performance of the chamber, the LMRI initiated numerical simulation of this ionisation chamber by Monte Carlo method using the MCNPX code. (authors)

  10. The draft Radioactive Substances (Basic Safety Standards) (Northern Ireland) Regulations 2002. Proposals for the implementation of European Directive 96/29/ Euratom (laying down basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionising radiation); consultation paper

    International Nuclear Information System (INIS)

    This consultation paper contains proposals for changes to the Radioactive Substances Act 1993 and the introduction of new subordinate legislation to implement aspects of the European Directive Euratom 96/29. This directive lays down basic safety standards for the protection of the health of workers and the general public against the dangers of ionising radiation. This consultation paper:- explains the background to the proposed regulations; summarises the results of the initial consultation exercise; describes the proposed changes; contains the draft regulations; describes the Next Steps and contains a draft Regulatory Impact Assessment

  11. Unbiased metal oxide semiconductor ionising radiation dosemeter

    International Nuclear Information System (INIS)

    To assess the application of MOS devices as low dose rate dosemeters, the sensitivity is the major factor although little studies have been performed on that subject. It is studied here, as well as thermal stability and linearity of the response curve. Other advantages are specified such as large measurable dose range, low cost, small size, possibility of integration. (D.L.)

  12. Occupational radiation hazards during pregnancy

    International Nuclear Information System (INIS)

    The general principles in teratology are discussed and it is pointed out that ionising radiation is only one of many agents with teratogenic effects. Human experience with radiation induced congenital malformations is insufficient to warrant conclusions about dose and effect. The teratogenic effects are then discussed in more detail and indications of radiation doses said to produce these are given. The question of a threshold dose is briefly discussed, as is the possibility of carcinogenesis. Finally precautions to be taken and the recommendations of the ICRP and the CEC are presented. (JIW)

  13. Repair Capacity for DNA Defects and Inactivation of Microorganisms During Treatment with Radiation and Other Agents

    International Nuclear Information System (INIS)

    The DNA can be considered as the main target of agents inactivating microorganisms. Counteracting are enzymatic processes that repair the defects produced, thereby increasing the survival of microorganisms. The proposed model is based on the hypothesis that only a limited number of defects can be repaired in a given time with a low error rate. If agents produce a higher number of defects, the fraction of not or incorrectly repaired defects increases exponentially. In the case of ionizing radiations, the deposited energy determines the number of DNA defects. Therefore, the effect has to be a linear/exponential function of the local energy density. Results from research in molecular biology, radiation chemistry, microdosimetry and computerized investigations of the biological evolution process are used in developing and justifying the described approach. DNA defects occur spontaneously with high frequency in living cells. They are repaired with the naturally occurring extremely low error rate. Therefore, it seems justified to use the number of spontaneously occurring DNS defects as an indicator for the capacity and effectiveness of the repair systems. For low LET radiations it is shown that a dose-rate of 102 to 103 Gy/h is necessary to ensure that the inactivation potential for microorganisms per unit of dose is completely used. At lower dose-rates the inactivation effect becomes a function of the dose-rate. Different low LET radiations may then show differing biological effectiveness. The synergistic effects of ionizing radiations and other agents can be anticipated if the other agent produces the same DNA defects as the radiation, or if it reduces the capacity and effectiveness of enzymatic mechanisms for the repair of the defects caused by radiation. (author)

  14. The Clinical Development of Molecularly Targeted Agents in Combination With Radiation Therapy: A Pharmaceutical Perspective

    International Nuclear Information System (INIS)

    Summary: This paper explores historical and current roles of pharmaceutical industry sponsorship of clinical trials testing radiation therapy combinations with molecularly targeted agents and attempts to identify potential solutions to expediting further combination studies. An analysis of clinical trials involving a combination of radiation therapy and novel cancer therapies was performed. Ongoing and completed trials were identified by searching the (clinicaltrials.gov) Web site, in the first instance, with published trials of drugs of interest identified through American Society of Clinical Oncology, European CanCer Organisation/European Society for Medical Oncology, American Society for Radiation Oncology/European Society for Therapeutic Radiology and Oncology, and PubMed databases and then cross-correlated with (clinicaltrials.gov) protocols. We examined combination trials involving radiation therapy with novel agents and determined their distribution by tumor type, predominant molecular mechanisms examined in combination to date, timing of initiation of trials relative to a novel agent's primary development, and source of sponsorship of such trials. A total of 564 studies of targeted agents in combination with radiation therapy were identified with or without concomitant chemotherapy. Most studies were in phase I/II development, with only 36 trials in phase III. The tumor site most frequently studied was head and neck (26%), followed by non-small cell lung cancer. Pharmaceutical companies were the sponsors of 33% of studies overall and provided support for only 16% of phase III studies. In terms of pharmaceutical sponsorship, Genentech was the most active sponsor of radiation therapy combinations (22%), followed by AstraZeneca (14%). Most radiation therapy combination trials do not appear to be initiated until after drug approval. In phase III studies, the most common (58%) primary endpoint was overall survival. Collectively, this analysis suggests that such

  15. Changes in the population structure of stem rust agent (PUCCINIA GRAMINIS) under low dose chronic radiation

    International Nuclear Information System (INIS)

    The data concerning the changes in population structure of Puccinia graminis, a causal agent of stem rust under low dose chronic radiation are present. The structure has been changed in 10-km ChNPP zone by appearance of a new population with high frequency of more virulent clones as compared to other regions of Ukraine

  16. Cancer chemoprevention by phytochemicals. Expectation for phytochemicals as preventive agents against radiation-induced carcinogenesis

    International Nuclear Information System (INIS)

    There is growing evidence from the studies using animal models that phytochemicals in plants have preventive effect on cancer induction, which is mediated by polyphenol anti-oxidative and anti-inflammatory functions. Some phytochemicals such as curcumin and epigallocatechin gallate have been moved onto clinical trials. These phytochemicals are also expected to reduce the deleterious effect of radiation, and to be a powerful tool for the prevention of radiation carcinogenesis. In this review, we summarized the general concept of cancer chemoprevention and usefulness of phytochemicals as cancer preventive agents, and pointed out their possibilities for prevention of radiation-induced carcinogenesis. (author)

  17. Antiangiogenic Agent Might Upgrade tumor Cell Sensitivity to Ionizing Radiation

    International Nuclear Information System (INIS)

    The understanding of the fundamental role of angiogenesis and metastasis in cancer growth has led to tremendous interest in research regarding its regulatory mechanisms and clinical implications in the management of cancer. The present study was conducted to evaluate the influence of the angiogenic regulators modification on the tumor growth and the cell sensitivity to ionizing radiation targeting the improvement of cancer therapeutic protocols. Accordingly, the antiangiogenic activity of apigenin and selenium was tested in vitro via MTT assay. The action of Apigenin and or Selenium was examined in vivo by using a model of solid tumor carcinoma (EAC). The growth rate of solid tumor in all experimental groups was measured by Caliper. The irradiated mice were exposed to 6.5 Gy of gamma rays. Apigenin 50 mg/kg body weight and selenium 5 μg per mice were daily administrated for 14 consecutive days after tumor volume reached 1mm3. The angiogenic activators TNF-α (key cytokine) in spleen, serum MMP 2 and MMP 9, liver and tumor NO, the lipid peroxidation (LPx) and angiogenic inhibitor TIMP-1 in spleen as well as, antioxidant markers (CAT, SOD, GPX) in tumor and liver tissue and DNA fragmentation in splenocytes were estimated to monitor efficacy of Apigenin and selenium in cancer treatment strategy. All parameters were determined as a time course on days 16 and 22 after tumor volume reached 1mm3. The using of MTT assay on EAC cells shows inhibition in EAC cell proliferation after the incubation with apigenin and /or selenium. The administration of apigenin and /or selenium to mice bearing tumor and to irradiated mice bearing tumor reduce significantly the TNF-α expression, MMP 2,9 , NO , LPx level and increased the antioxidant enzymes (GPx , SOD and CAT) activities. The DNA fragmentation and the antiangiogenic factors TIMP-1 were significantly increased when compared with their values in mice bearing tumor or in irradiated mice bearing tumor. From the results obtained

  18. Two-photon ionisation of metastable helium

    International Nuclear Information System (INIS)

    An experimental and theoretical study of two-photon ionisation of He(21S) and He(23S) by a pulsed laser strong enough to saturate the ionisation process through the 3P intermediate and to display the quadrupole transition through the 3D intermediate is presented. A pronounced dip sensitive to the laser pulse shape in the profile of the 21S-31P resonance is shown to stem from a competition between relaxation and ionisation. Further complex but reproducible unexpected structure, which is not yet understood, is seen in both the singlet and triplet 2S-3P resonances. (author)

  19. Radio-oxidation of an EPDM elastomer under weak or strong ionising radiations: measurement and modelling of dioxygen consumption; Radio-oxydation d'un elastomere de type EPDM lors d'irradiations faiblement ou fortement ionisantes: mesure et modelisation de la consommation de dioxygene

    Energy Technology Data Exchange (ETDEWEB)

    Dely, N

    2005-10-15

    Usually, the irradiation of polymers under ionising radiations occurs in air that is in the presence of oxygen. This leads to a radio oxidation process and to oxygen consumption. Our material is an EPDM elastomer (ethylene propylene 1,4 hexadiene) used as insulator in control-command cables in nuclear plants (Pressurised Water Reactor). A specific device has been conceived and built up during this PhD work for measuring very small oxygen consumptions with an accuracy of around 10%. Ionising radiations used are electrons at 1 MeV and carbon ions at 11 MeV per nucleon. Under both electron and ion irradiations, the influence of oxygen pressure on oxygen consumption has been studied in a very large range: between 1 and 200 mbar. In both cases, the yield of oxygen consumption is constant in-between 200 and 5 mbar. Then, at lower pressures, it decreases appreciably. On the other hand, the oxygen consumption during ion irradiation is four times smaller than during electron irradiation. This emphasizes the role of the heterogeneity of the energy deposition at a nano-metric scale. The adjustment of the experimental results obtained during electron irradiation with the general homogeneous steady-state kinetic model has allowed extracting all the values of the kinetic parameters for the chosen mechanism of radio oxidation. The knowledge of these numbers will allow us to face our results obtained during ion irradiation with a heterogeneous kinetic model under development. (author)

  20. Mutagenic effect of ionizing radiation and chemical and environmental agents in Tradescantia

    International Nuclear Information System (INIS)

    The studies covered the following problems: an influence of some environmental agents on the mutagenic effectiveness of ionizing radiation, interaction between ionizing radiation and chemical mutagens in the induction of somatic mutations and also an application of Tradescantia model system for biological monitoring. The studies showed that the pretreatment of Tradescantia plants with sodium fluoride or the modification of the soil composition with dolomite admixture, visibly influences plants radiosensitivity. The analysis of the changes in the dose-response curves suggested that the employed agents were influencing in different ways the repair processes of the DNA. The studies on the interaction between agents proved that the synergistic effect occurs in case of combined action of ionizing radiation with such chemical mutagens as ethyl methansulfonate or 1,2 dibromomethane. It was also discovered that in the range of low doses the effect was proportional to radiation dose and total exposition to chemical mutagen. The field application of Tradescantia method defined the mutagenicity of air pollution in the Cracow area. The highest frequencies of mutations were detected after the Chernobyl accident and after the damage of the filters in the Pharmaceutical Plant. The applied method was evaluated in respect of its usefulness for biological monitoring of environmental pollution. 163 refs. (author)

  1. Innovations in gas filled ionisation chambers

    International Nuclear Information System (INIS)

    The gas filled parallel plate ion chamber and coaxial cylindrical ion chambers are widely used for detection of nuclear radiations for more than hundred years. Thin Metal electrodes or metal coated planes are used as cathode and anodes in both parallel plate and cylindrical ionization chambers since its invention. For neutral particle detection, either the ionising medium or a coated electrode surface is used as a converter material for producing secondary charged particles which are detected in these ionisation chambers. Boron, and 235U are coated as thin layer on the cathode surface with optimum thickness to give maximum neutron detection sensitivity. The neutron sensitivity mostly depends upon the coated surface area and to enhance the neutron sensitivity diameter and the length/ diameter of the coated electrodes have to be increased which also results in an increase in the volume of the counter. For many applications, it is necessary to reduce the size of the counter by a factor of 2 to 5 but having the same efficiency. Recently this has been achieved by designing a non planar electrode surface/ s which has surface area larger by a factor or up to five keeping the external dimensions the same. By using this new technique, it is possible to increase the coated area up to 5 times, without changing the overall dimensions of the counter both for proportional counters and ion chambers. The three methods have been developed to enhance the neutron sensitivity the use of: additional coated wires, coated baffles, coated fins: in sensitive volume of gas detectors. The introduction of these three-dimensional boron coated structures into the sensitive volume without enlarging the outer detector dimensions increases the Boron/Uranium content in the sensitive region without any significant change in the nature of the pulses from these counters. In the newly developed Wire Plane Chambers both in the DC mode and pulse mode, wire planes have been used as anode and cathodes with

  2. Evolution of tubular singular pulsed beams in a nonlinear dielectric medium upon ionisation

    International Nuclear Information System (INIS)

    The dynamics of a high-power femtosecond tubular pulsed beam in a dielectric medium is numerically analysed upon optically induced ionisation. It is found that the balance between nonlinearities of opposite sign and different magnitude in the case of multiphoton ionisation favours the establishment of a quasi-soliton regime of radiation propagation over a distance exceeding several diffraction lengths. The use of these beams enables attaining high-density light fields and generate high-density plasmas. (interaction of laser radiation with matter. laser plasma)

  3. Radiation Recall Reaction: Two Case Studies Illustrating an Uncommon Phenomenon Secondary to Anti-Cancer Agents

    International Nuclear Information System (INIS)

    Radiation recall phenomenon is a tissue reaction that develops throughout a previously irradiated area, precipitated by the administration of certain drugs. Radiation recall is uncommon and easily neglected by physicians; hence, this phenomenon is underreported in literature. This manuscript reports two cases of radiation recall. First, a 44-year-old man with nasopharyngeal carcinoma was treated with radiotherapy in 2010 and subsequently developed multi-site bone metastases. A few days after the docetaxel-based chemotherapy, erythema and papules manifested dermatitis, as well as swallowing pain due to pharyngeal mucositis, developed on the head and neck that strictly corresponded to the previously irradiated areas. Second, a 19-year-old man with recurrent nasal NK/T cell lymphoma initially underwent radiotherapy followed by chemotherapy after five weeks. Erythema and edema appeared only at the irradiated skin. Both cases were considered chemotherapeutic agents that incurred radiation recall reactions. Clinicians should be knowledgeable of and pay attention to such rare phenomenon

  4. Keeping the Universe ionised: Photo-ionisation heating and the critical star formation rate at redshift z = 6

    CERN Document Server

    Pawlik, Andreas H; van Scherpenzeel, Eveline

    2008-01-01

    The critical star formation rate density required to keep the intergalactic hydrogen ionised depends crucially on the average rate of recombinations in the intergalactic medium (IGM). This rate is proportional to the clumping factor C = / avg(rho_b)^2, where rho_b and avg(rho_b) are the local and cosmic mean baryon density, respectively, and the brackets indicate spatial averaging over the recombining gas in the IGM. We perform a suite of cosmological smoothed particle hydrodynamics simulations that include radiative cooling to calculate the volume-weighted clumping factor of the IGM at redshifts z >= 6. We focus on the effect of photo-ionisation heating by a uniform ultra-violet background and find that photo-heating strongly reduces the clumping factor because the increased pressure support smoothes out small-scale density fluctuations. Photo-ionisation heating is often said to provide a negative feedback on the reionisation of the IGM because it suppresses the cosmic star formation rate by boiling the ga...

  5. Comportement des pesticides ionisables dans les sols

    OpenAIRE

    Kah, Mélanie; Brown, Colin D.

    2007-01-01

    Ionisable pesticides can be partially ionised within the range of natural soil pH and this strongly influences their reactivity in soils. This group includes important, worldwide contaminants of groundwater and surface waters. It is essential that their specific behaviour is recognised within risk assessment procedures. Experiments were carried out with ten pesticides (six acids and four bases) and nine arable soils (range in pH, texture and organic matter content) to advance the understandin...

  6. Radiobiological aspects of application of interleucine as agents for the first aid under strong radiation action

    International Nuclear Information System (INIS)

    The paper substantiates the application of the interleucine-1 beta (IL-1) as an emergency medical care agent in case of the acute emergency exposure of a human being. During simulation experiments a human recombinant IL-1 was added to suspension of the affected bony marrow-cells extracted a few minutes following the total 5 Gy exposure of Fi male-mice (CBAxC57B1). Recombinant mouse IL-3 and GM-CSF agents (produced by Bering company, Germany) were used for comparison purpose (agent concentration constituted 100-10000 unit/ml). The incubated bony marrow cells were tested for trunk potencies in mice-recipients irradiated by 8.5 Gy dose during 24 h. Following nine days the colonies in their spleen and bony marrow cellular texture were estimated. IL-1 was shown to have the protective effect both on separated trunk type hemopoietic cells and on the whole body irradiated hemopoietic system. IL-1 turned to be similar to radiation-protective agents of polysaccharide nature and to radiation-protective EIR procedure. It is pointed out that IL-1 has no whole body toxic or any other by effects

  7. The combination of novel targeted molecular agents and radiation in the treatment of pediatric gliomas

    Directory of Open Access Journals (Sweden)

    Tina eDasgupta

    2013-05-01

    Full Text Available Brain tumors are the most common solid pediatric malignancy. For high-grade, recurrent or refractory pediatric brain tumors, radiation therapy (XRT is an integral treatment modality. In the era of personalized cancer therapy, molecularly targeted agents have been designed to inhibit pathways critical to tumorigenesis. Our evolving knowledge of genetic aberrations in low-grade gliomas is being exploited with targeted inhibitors. These agents are also being combined with XRT to increase their efficacy. In this review, we discuss novel agents targeting three different pathways in low-grade gliomas, and their potential combination with XRT. B-Raf is a kinase in the Ras/Raf/MAPK kinase pathway, which is integral to cellular division, survival and metabolism. In low-grade pediatric gliomas, point mutations in BRAF (BRAF V600E or a BRAF fusion mutation (KIAA1549:BRAF causes overactivation of the MEK/MAPK pathway. Pre-clinical data shows cooperation between XRT and tagrgeted inhibitors of BRAF V600E, and MEK and mTOR inhibitors in the gliomas with the BRAF fusion. A second important signaling cascade in pediatric glioma pathogenesis is the PI3 kinase (PI3K/mTOR pathway. Dual PI3K/mTOR inhibitors are poised to enter studies of pediatric tumors. Finally, many brain tumors express potent stimulators of angiogenesis. Several inhibitors of immunomodulators are currently being evaluated in in clinical trials for the treatment of recurrent or refractory pediatric central nervous system (CNS tumors. In summary, combinations of these targeted inhibitors with radiation are currently under investigation in both translational bench research and early clinical trials. We summarize the molecular rationale for, and the pre-clinical data supporting the combinations of these targeted agents with other anti-cancer agents and XRT in pediatric gliomas. Parallels are drawn to adult gliomas, and the molecular mechanisms underlying the efficacy of these agents is discussed

  8. Applying radiation approaches to the control of public risks from chemical agents

    International Nuclear Information System (INIS)

    IF a hazardous agent has a threshold, prevention is the obvious measure of success. To the eyes of this author, success is also achieveable for a hazardous agent that may have no threshold and that causes its effects in a probabilistic manner. First, the technical people responsible for protection must be given a reasonable, well defined risk objective by governmental authorities. To the extent that they meet that objective (1) without unnecessarily increasing operational costs, (2) without interfering unnecessarily with operational activities, and (3) without diverting resources away from greater risks, they are successful. Considering these three qualifications, radiation protection for members of the public can hardly be presented as the panacea for other hazardous agents. It would be an error to dismiss the improvement opportunities discussed above as being of acdemic interest only. Decades of experience with radiation have demonstrated that these problems are both real adn significant. In the US the axioms discussed above are accepted as scientific fact for radiation by many policy makers, the news media and the public. For any operation the collective dose is calculated using zero dose as the lower limit of integration, the results are converted to cancer deaths using the risk coefficients, and decisions are made as though these deaths would actually occur without governmental intervention. As a result, billions of dollars and a very large number of highly skilled persons are being expended to protect against radiation doses far smaller than geographical variations in the natural radiation background. These expenditures are demanded by, and required for well-meaning, nontechnical people who have been misled. It is often stated by knowledgeable people that if the degree of protection required for radiation were also to be requested for the other hazards, human progress would come to a halt. If the radiation approaches are to be used in the control of public

  9. Radiation-curable impregnating agents for the conservation of archaeologic wooden objects (part 3) and conservation experiments applying these agents to intact and artificially decayed wood samples

    International Nuclear Information System (INIS)

    As a continuation of the work described in the reports OEFZS Ber. No. 4165 and No. 4195, impregnating agents curable by ionizing radiation such as polymerizable monomers or artificial resins have been investigated. Specific weight and viscosity of the liquid mixtures have been as well determined as the specific weight and gel content of the gamma radiation-cured samples. Hardness and elastic behaviour have been estimated only, the shrinkage during hardening has been calculated. In continuation of OEFZS Ber. No. 4198, conservation experiments have been performed with selected impregnating agents by applying these agents to intact and chemically decayed wood samples, whereby the monomer uptake, the alteration of dimensions and volume and the deformation of the samples have been taken for the evaluation of the impregnating agents. (Author)

  10. Combined effect of environmental radiation and other agents: Is there a synergism trap?

    International Nuclear Information System (INIS)

    Most assessments of possible deleterious outcomes from environmental and occupational exposures concentrate on single agents and neglect the potential for combined effects, i.e. synergisms or antagonisms. Biomechanistic considerations based on multistep processes such as carcinogenesis indicate the potential for highly detrimental interactions, if two or more consecutive rate limiting steps are specifically effected by different agents. However, low specificity towards molecular structure or DNA-sequence - and therefore exchangeability - of many genotoxic agents indicate little functional specificity and therefore little vulnerability towards synergism at most occupational and environmental exposure situations. The low potential for significant combined effects for those common low exposure situations where non-genotoxic agents with highly non-linear dose effect relationships and apparent thresholds are involved, is also evident. Nevertheless, a quantitative assessment of the contribution of synergistic interactions to the total detriment from natural and man-made toxicants based on experimental data is far away. The existing database 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. 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. Finally an important question considering the shape of dose effect relationships for ionizing radiation arises from the unresolved question whether real or apparent thresholds may be used for any genotoxic agent separately or only one time for an exposed genome. (author)

  11. Sesamol protects human embryonic kidney cells from radiation induced cell death: a potential radioprotective agent

    International Nuclear Information System (INIS)

    Radioprotectors are agents which reduce the radiation effects on cell when applied prior to exposure of radiation. In our earlier studies, we have demonstrated that sesamol protected DNA (plasmid and calf thymus) and V79 cells from radiation induced cell death and the effect was higher (DMF=2) in comparison to melatonin (DMF=1.3). This prompted us to study, sesamol mediated radioprotection in detail to understand the mechanism of action. We have chosen human embryonic kidney (HEK) cells to understand the mechanism of radioprotection. The HEK cells were treated with sesamol before exposure of g rays (60Co teletherapy, Bhabhatron II) in the radiation dose range 0-7 Gy for clonogenic survival. Toxicity, antioxidant enzyme activity other biochemical assays were performed. Flow cytometric analysis (FACS Calibre, BD, USA) was used to determine the apoptotic population and mitochondrial membrane potential (Rh 123, JC-1). ROS was determined using DCFHDA. Cell cycle analysis, caspase 3 activity and cytochrome C were also measured. Results suggested that sesamol protected HEK cells from cell death. The dose modifying factor for sesamol was 1.3, whereas the alpha protection factor was 2. Sesamol inhibited radiation induced cell cycle arrest in G2/M phase; ROS generation and depolarization of mitochondrial membrane potential and caspase-3 activity. Sesamol inhibited damage of critical cellular components (protein, lipids, membrane and amino acid) and maintained the redox status of cells. The results will be helpful in understanding the mechanistic aspects and development of sesamol based radioprotector. (author)

  12. Radiation proctitis in the rat. Sequential changes and effects of anti-inflammatory agents

    Energy Technology Data Exchange (ETDEWEB)

    Northway, M.G.; Scobey, M.W.; Geisinger, K.R.

    1988-11-01

    Female Wistar rats were treated with single exposure irradiation to 2 cm of distal colon to cause radiation proctitis. All animals were evaluated by examination, colonoscopy and histologic evaluation for changes post-irradiation. Exposures of 10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5 and 30 Gy caused dose-related clinical and histologic changes peaking at 7 to 15 days post-exposure. Rats treated with 20 Gy were colonoscoped and biopsied daily and showed sequential post-irradiation endoscopic changes ranging from mucosal edema and mild inflammatory changes to erosion and ulcers. Histologically, crypt abscess and mural wall necrosis similar to changes found in the human rectum after radiotherapy were noted. Treatment with nonsteroidal anti-inflammatory agents, (aspirin, indomethacin, piroxicam), misoprostol (a prostaglandin E1 analogue), or sucralfate (an anti-ulcer agent) did not ameliorate nor exacerbate radiation proctitis in rats exposed to 22.5 Gy. We conclude from these data that the female Wistar rat is a good model for studying radiation proctitis because endoscopic, histologic, and clinical changes seen post-exposure closely resemble those found in man.

  13. Radiation-curable impregnating agents for the conservation of archaelogic wooden objects

    International Nuclear Information System (INIS)

    Impregnating agents curable by ionizing radiation, such as free radical polymerizable monomers, monomer mixtures of artificial resins (dissolved in monomers), have been investigated. Specific weight and viscosity of the liquid mixtures have been determined. Applying increasing gamma doses the curing has been followed. Specific weight and gel content of the cured samples have been determined, and their hardness and elastic properties have been estimated. From the change in specific weight during hardening the shrinkage can be deduced. The results are to be discussed. (Author)

  14. Ionisation as indicator for cosmic ray acceleration

    Science.gov (United States)

    Schuppan, F.; Röken, C.; Fedrau, N.; Becker Tjus, J.

    2014-06-01

    Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies E ≲ 1 TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of atomic and molecular hydrogen, can lead to observable signatures. A correlation study of both gamma ray emission, induced by proton-proton interactions of cosmic ray protons with kinetic energies Ep ≥ 280 MeV with ambient hydrogen, and ionisation induced by cosmic ray protons of kinetic energies Ep sub)TeV cosmic rays.

  15. Biological effects of radiation in combination with other physical, chemical or biological agents. Annex L

    International Nuclear Information System (INIS)

    This Annex considers the combined action of radiation with potentially important environmental conditions. Since there is a scarcity of systematic data on which an analysis of combined effects can be based, this Annex will be more hypothetical and will attempt to suggest definitions, to identify suitable methods of analysis, to select from a large amount of diffuse information the conditions and the data of importance for further consideration and to provide suggestions for future research. For humans in environmental circumstances the UNSCEAR Committee has been unable to document any clear case of synergistic interaction between radiation and other agents, which could lead to substantial modifications of the risk estimates for significant sections of the population

  16. Combined radiation-protective and radiation-sensitizing agents. IV. Measurement of intracellular protector concentrations

    International Nuclear Information System (INIS)

    Radiosensitization of hypoxic V79 Chinese hamster cells by 0.5 mM misonidazole at approximately 0-4 degrees C is substantially enhanced by pretreating the cells overnight with 0.1 mM buthionine sulfoximine, which lowers the cellular glutathione content to 5% of control values (from 4 mM to approximately 0.2 mM). The enhanced sensitization is reversed by concentrations of exogenous cysteine that are much lower (0.02 mM) than the original glutathione content. Reduced Co-enzyme A affords reversal of the enhancing effect at concentrations of about 1 mM. Sodium ascorbate gives no protection at all even at concentrations of 2 mM. The intracellular concentration of the reducing agents was measured using a spin-through oil technique. There was no diffusion of Co-A (MW greater than 750) or ascorbate (excluded by charge) into the cells. In contrast, cysteine was rapidly concentrated by factors of 4-10, even at the low temperatures used. Extracellular ascorbate's inability to radioprotect argues against electron transfer across the cell membrane as a mechanism for radioprotection. This mechanism could have explained the ability of exogenous thiols to radioprotect in former studies using glutathione, and in the present studies using Co-A. The potential of cysteine to be concentrated by cells poses a problem in the interpretation of exogenous protection by non-diffusing thiols, since trace contamination by cysteine could lead to the actual protection observed. Cysteine could also be formed by exchange reactions of exogenous thiols with the disulfide of cysteine, present in all media formulations

  17. Effects of some nonsteroidal anti-inflammatory agents on experimental radiation pneumonitis

    Energy Technology Data Exchange (ETDEWEB)

    Gross, N.J.; Holloway, N.O.; Narine, K.R. (Medical Radiology Service, Hines VA Hospital, Maywood, IL (United States))

    1991-09-01

    Corticosteroids have previously been found to be protective against the mortality of radiation pneumonitis in mice, even when given well after lethal lung irradiation. The authors explored the possibility that this effect was due to their well-known anti-inflammatory actions by giving various nonsteroidal inhibitors of arachidonate metabolism to groups of mice that had received 19 Gy to the thorax (bilaterally). Treatments of four cyclooxygenase inhibitors, one lipoxygenase inhibitor, and one leukotriene receptor antagonist, given by various routes in various doses, were commenced 10 weeks after irradiation or sham irradiation and continued throughout the period when death from radiation pneumonitis occurs, 11-26 weeks after irradiation. Each of the treatments had the appropriate effect on arachidonate metabolism in the lungs as assessed by LTB4 and PGE2 levels in lung lavage fluid. The principal end point was mortality. The 5-lipoxygenase inhibitor diethylcarbamazine and the LTD4/LTE4 receptor antagonist LY 171883 markedly reduced mortality in dose-response fashion. The effects of cyclooxygenase inhibitors were divergent; piroxicam and ibuprofen were marginally protective, indomethacin in all doses accelerated mortality, and aspirin reduced mortality in a dose-response fashion. These results suggest that the protective effect of corticosteroids in radiation pneumonitis can be tentatively attributed to their anti-inflammatory actions, and that nonsteroidal anti-inflammatory agents, particularly those that affect lipoxygenase products, may offer equal or better protection than corticosteroids against mortality due to radiation pneumonitis.

  18. Use of virtual simulator for agent training in radiation protection actions in major events

    International Nuclear Information System (INIS)

    With the proximity of the events of the Olympic Games, Brazil can become a great place of visibility for running dirty bombs or any other radiation mode proliferation by terrorists. Aware of these problems, the government and the organizations created managements of emergencies to ensure that these events elapse in an orderly and safe manner. The management of emergency situations at an event is a complex problem, which involves dynamic, unforeseen and unintended situations, emphasizing the potential complexity of the contexts in which organizations operate and, as a consequence, the people involved in the execution of multiple tasks from activities that require intense cognitive effort, are often challenged to adapt dynamically to maintain the productivity of the organization at satisfactory levels of performance usually impedes these people reflect on the results of their actions and learn from them. Therefore, it is extremely important to create tools that address the methods and techniques of Cognitive Task Analysis (CTA) to assist in the previous training of the security agents, for example, detection and approaches of people who carry radioactive elements. One of the possible ways to accomplish this training is through the use of virtual reality. Virtual environments bring some advantages like reducing costs and risks. The aim of this paper is to present a virtual simulator to evaluate the use in training agents in major events. As a case study, the Maracana and the agents of the National Nuclear Energy Commission (CNEN) was chosen. (author)

  19. Use of virtual simulator for agent training in radiation protection actions in major events

    Energy Technology Data Exchange (ETDEWEB)

    Passos, Claudio Azevedo, E-mail: cpassos.cp2@gmail.com [Universidade Federal do Rio de Janeiro (CCMN/NCE/UFRJ), Rio de Janeiro, RJ (Brazil); Mol, Antonio Carlos A.; Carvalho, Paulo V.R., E-mail: mol@ien.gov.br, E-mail: paulov@ien.gov.br [nstituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Lima, Fabio Almeida; Rocha, Tiago Lima, E-mail: profantoniocarlosmol@gmail.com, E-mail: falmeida@unicarioca.edu.br, E-mail: tlrtiago@gmail.com [Centro Universitario Carioca (Unicarioca), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    With the proximity of the events of the Olympic Games, Brazil can become a great place of visibility for running dirty bombs or any other radiation mode proliferation by terrorists. Aware of these problems, the government and the organizations created managements of emergencies to ensure that these events elapse in an orderly and safe manner. The management of emergency situations at an event is a complex problem, which involves dynamic, unforeseen and unintended situations, emphasizing the potential complexity of the contexts in which organizations operate and, as a consequence, the people involved in the execution of multiple tasks from activities that require intense cognitive effort, are often challenged to adapt dynamically to maintain the productivity of the organization at satisfactory levels of performance usually impedes these people reflect on the results of their actions and learn from them. Therefore, it is extremely important to create tools that address the methods and techniques of Cognitive Task Analysis (CTA) to assist in the previous training of the security agents, for example, detection and approaches of people who carry radioactive elements. One of the possible ways to accomplish this training is through the use of virtual reality. Virtual environments bring some advantages like reducing costs and risks. The aim of this paper is to present a virtual simulator to evaluate the use in training agents in major events. As a case study, the Maracana and the agents of the National Nuclear Energy Commission (CNEN) was chosen. (author)

  20. Nucleation in an ultra low ionisation environment

    DEFF Research Database (Denmark)

    Enghoff, Martin Andreas Bødker

    In this work we have studied aerosol formation at ultra-low ionisation levels, using the existing deep underground science facility at Boulby mine, UK. At 1100 m depth, with a corresponding factor 106 reduction in cosmic ray muon flux, the Boulby facility is an ideal place to study the role of ions...

  1. Unjustified prenatal radiation exposure in medical applications

    International Nuclear Information System (INIS)

    The exposure to the radiation ionising of pregnant women, frequently constitutes motive of preoccupation for the expectant mother and the medical professionals taken the responsibility with its attention. The protection of the embryo-fetus against the ionising radiation is of singular importance due to its special vulnerability to this agent. On the other hand the diagnosis or treatment with radiations ionising beneficial for the expectant mother, are only indirectly for the embryo-fetus that is exposed to a hazard without perceiving anything. The present paper presents the experience obtained in the clinical and dosimetric evaluation from twenty-one pregnant patients subjected to diverse radiodiagnostic procedures or nuclear medicine during the years 1999-2000. The obtained results evidence that 24% of the patients was subjected to procedures of nuclear medicine with diagnostic purposes. While the period of pregnancy of the patients ranged between 4 and 12 weeks, it could be concluded that in all the cases the doses received by the patients in the whole body did not exceed 2 mSv. When conjugating the period of pregnancy of the patients with the doses received, there is no evidence of significant risk for the embryo-fetus. Paradoxically the physicians of assistance suggested to their patients in all the cases to carry out the interruption of the pregnancy, demonstrating with this decision ignorance on the biological effects of the ionizing radiations during the prenatal exposures. (author)

  2. EDDIX--a database of ionisation double differential cross sections.

    Science.gov (United States)

    MacGibbon, J H; Emerson, S; Liamsuwan, T; Nikjoo, H

    2011-02-01

    The use of Monte Carlo track structure is a choice method in biophysical modelling and calculations. To precisely model 3D and 4D tracks, the cross section for the ionisation by an incoming ion, double differential in the outgoing electron energy and angle, is required. However, the double differential cross section cannot be theoretically modelled over the full range of parameters. To address this issue, a database of all available experimental data has been constructed. Currently, the database of Experimental Double Differential Ionisation Cross sections (EDDIX) contains over 1200 digitalised experimentally measured datasets from the 1960s to present date, covering all available ion species (hydrogen to uranium) and all available target species. Double differential cross sections are also presented with the aid of an eight parameter functions fitted to the cross sections. The parameters include projectile species and charge, target nuclear charge and atomic mass, projectile atomic mass and energy, electron energy and deflection angle. It is planned to freely distribute EDDIX and make it available to the radiation research community for use in the analytical and numerical modelling of track structure. PMID:21113060

  3. Epidemiology and quantitation of environmental risk in humans from radiation and other agents

    International Nuclear Information System (INIS)

    The identification and quantitation of environmental risk in humans is one of the main problems to be solved in order to improve the protection of individuals and of human populations against physical and chemical pollutants. Epidemiology plays a central role in the evaluation of health risk directly in human populations. In this volume are collected 33 lectures presented at the AS! course on ''Epidemiology and quantitation of environmental risk in humans from radiation and other agents: potential and limitations'', sponsored by NATO and Italian Association of Radiobiology and organized by ENEA. The course has been devoted to a number of aspects of environmental risk analysis and evaluation based on epidemiological investigation. Basic epidemiological concepts and methods have been reviewed. Fundamentals of dosimetry and microdosimetry were presented in relation to the contribution of epidemiology in defining the dose effect relationships for radiation carcinogenesis and its relation with age, sex and ethnicity. The mechanisms of carcinogenesis as a multi-stage process were illustrated. One of the main topics was 'cancer epidemiology' and its correlation with: - occupational and non-occupational exposure to radiation - diagnostic and therapeutic irradiation - cancer proneness - hereditary and familiar diseases - abnormal response to carcinogens - environmental pollution in air and water - exposure to radon in mines and in building material - atomic bomb explosion - chemotherapy - dioxin and related compounds

  4. 188Re-ethylene dicysteine: a novel agent for possible use in endovascular radiation therapy.

    Science.gov (United States)

    Das, T; Banerjee, S; Samuel, G; Sarma, H D; Ramamoorthy, N; Pillai, M R

    2000-10-01

    Several agents, such as 188ReO4-, 188Re-MAG3 and 188Re-DTPA are currently under investigation as radiation sources in liquid-filled balloons for prevention of restenosis following coronary angioplasty. Bearing in mind the risk factor associated with leakage of radioactivity in the event of balloon rupture, the criteria sought in selecting suitable agents for endovascular radiation therapy (EVRT) are rapid clearance and low dose to vital organs. Since 99Tcm labelled ethylene dicysteine (EC) is a well established agent for renal tubular function imaging, the use of 186Re-ethylene dicysteine as a potential agent for prevention of restenosis after angioplasty has been evaluated previously. Therefore, it was of interest to evaluate the applicability of the more potential isotope of rhenium, 188Re, a high energy beta-emitter (Ebetamax = 2.12 MeV) with a suitable T 1/2 = 16.9 h, obtainable carrier-free from the 188W-188Re generator, as an attractive and alternative radionuclide for labelling with L,L-EC. In this paper, the preparation and pharmacological behaviour of the 188Re complex of ethylene dicysteine are reported. The complex can be prepared in high yields (99.5%) under optimized conditions of pH 2-3, at a ligand concentration of 15 mM, 50 microg (0.18 mM) carrier rhenium and using 2 mg x mL(-1) stannous chloride. On storage at 4 degrees C, the RC purity was more than 97% after 48 h when prepared under optimum conditions. Biodistribution studies in Wistar rats showed the desired characteristics of fast blood clearance and low retention of activity in the vital organs (< 2% in intestine, < 1% in stomach, < 0.5% in liver) with a high renal excretion (90.65+/-0.6%) at 3 h post-injection. These results confirm the advantages of using the 188Re-EC complex compared with perrhenate and other rhenium radiopharmaceuticals currently being used in balloons for EVRT. PMID:11130335

  5. Variable filtered photographic film as a radiation detector for environmental radiation monitoring

    Science.gov (United States)

    Majid, Zafri Azran Abdul; Junet, Laila Kalidah; Hazali, Norazlanshah; Abdullah, Abdul Adam; Hanafiah, Megat Ahmad Kamal Megat

    2013-05-01

    Environmental radiation is an ionising radiation that present in the natural environment which mostly originates from cosmic rays and radionuclide agents in the environment. This may lead the population to be exposed to the radiation. Therefore, the environmental radiation needs to be observed cautiously to minimize the impact of radiation. However, there is no specific or proper monitoring device that provides an outdoor environmental radiation monitoring. Hence, a new outdoor environmental radiation monitoring device was developed. A photographic film has been chosen as a dosimeter. The purpose of this study was to prove the covered photographic film attached with variable filter can be used to develop environmental radiation monitoring device to detect the ionising radiation. The filter used was variable thickness of plastic, aluminium (Al) and lead (Pb). The result from the study showed that the mean optical density (OD) values for medium speed film are in the range 0.41 to 0.73, and for fast speed film the OD values are in the range 0.51 to 1.35. The OD values decreased when the filter was attached. This has proven that the photographic film can be used to detect radiation and fast speed film was more sensitive compared to medium speed film.

  6. Non-targeted effects of ionising radiation—Implications for low dose risk

    DEFF Research Database (Denmark)

    Kadhim, Munira; Salomaa, Sisko; Wright, Eric;

    2013-01-01

    respect to systemic (human health) consequences at low and intermediate doses of ionising radiation. Other outstanding questions include links between the different non-targeted responses and the variations in response observed between individuals and cell lines, possibly a function of genetic background....... Furthermore, it is still not known what the initial target and early interactions in cells are that give rise to non-targeted responses in neighbouring or descendant cells. This paper provides a commentary on the current state of the field as a result of the non-targeted effects of ionising radiation (NOTE......) Integrated Project funded by the European Union. Here we critically examine the evidence for non-targeted effects, discuss apparently contradictory results and consider implications for low-dose radiation health effects. © 2012 Elsevier B.V. All rights reserved....

  7. Quantitative functional lung imaging with synchrotron radiation using inhaled xenon as contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Bayat, S. [TIMC-PRETA, UMR CNRS 5525, Laboratoire de Physiologie, Universite Joseph Fourier, Faculte de Medecine, Domaine de la Merci, Grenoble (France)]. E-mail: sam.bayat@imag.fr; Le Duc, G.; Berruyer, G.; Nemoz, C.; Monfraix, S.; Fiedler, S.; Thomlinson, W. [European Synchrotron Radiation Facility, BP 220, Grenoble (France); Porra, L.; Suortti, P. [Department of Physics, University of Helsinki, Helsinki (Finland); Standertskjoeld-Nordenstam, C.G. [Department of Radiology, University of Helsinki Central Hospital, Helsinki (Finland); Sovijaervi, A.R.A. [Department of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital, Helsinki (Finland)

    2001-12-01

    Small airways play a key role in the distribution of ventilation and in the matching of ventilation to perfusion. The purpose of this study was to introduce an imaging method that allows measurement of regional lung ventilation and evaluation of the function of airways with a small diameter. The experiments were performed at the Medical Beamline of the European Synchrotron Radiation Facility. Monochromatic synchrotron radiation beams were used to obtain quantitative respiration-gated images of lungs and airways in two anaesthetized and mechanically ventilated rabbits using inhaled stable xenon (Xe) gas as a contrast agent. Two simultaneous images were acquired at two different energies, above and below the K-edge of Xe. Logarithmic subtraction of the two images yields absolute Xe concentrations. This technique is known as K-edge subtraction (KES) radiography. Two-dimensional planar and CT images were obtained showing spatial distribution of Xe concentrations within the airspaces, as well as the dynamics of filling with Xe. Bronchi down to 1 mm in diameter were visible both in the subtraction radiographs and in tomographic images. Absolute concentrations of Xe gas were calculated within the tube carrying the inhaled gas mixture, small and large bronchi, and lung tissue. Local time constants of ventilation with Xe were obtained by following the evolution of gas concentration in sequential computed tomography images. The results of this first animal study indicate that KES imaging of lungs with Xe gas as a contrast agent has great potential in studies of the distribution of ventilation within the lungs and of airway function, including airways with a small diameter. (author)

  8. Mutagenic interactions between near-ultraviolet (365 nm) radiation and alkylating agents in Escherichia coli

    International Nuclear Information System (INIS)

    The mutagenic interaction between near-ultrviolet (365 nm) radiation and the alkylting agents ehtyl methanesulponate (EMS) and methyl methanesulphonate (MMS) was studied in a repair-component and an excision-deficient stram of Escherichia coli. Near-UV raditation modified the metabolic response of of exposure to these chemicals and either reduced or increased their mutagenic efficiency. Based on these results, an experimental model was formulated to explain the mutagenic interactions that occur between near-UV and various agents that induce prototrophic reverants cia error-prone repair of DNA. According to this model, low doses of near-UV provoke conditions for mutation frequency decline (MFI) and lead to a mutagenic antagonism. With increasing near-Uv doses, damage to constitutive error-free repairs system increases, favouring the error-prone system and inhibiting the MFD. Under these conditions there will be a progressive decrease in antagonism until at high doses an enhancement of mutation frequency (positive interaction) will occur. (orig.)

  9. Investigating the stability of gadolinium based contrast agents towards UV radiation.

    Science.gov (United States)

    Birka, Marvin; Roscher, Jörg; Holtkamp, Michael; Sperling, Michael; Karst, Uwe

    2016-03-15

    Since the 1980s, the broad application of gadolinium(Gd)-based contrast agents for magnetic resonance imaging (MRI) has led to significantly increased concentrations of Gd in the aqueous environment. Little is known about the stability of these highly polar xenobiotics under environmental conditions, in wastewater and in drinking water treatment. Therefore, the stability of frequently applied Gd-based MRI contrast agents towards UV radiation was investigated. The hyphenation of hydrophilic interaction liquid chromatography (HILIC) with inductively coupled plasma mass spectrometry (ICP-MS) and of HILIC with electrospray ionization mass spectrometry (ESI-MS) provided quantitative elemental information as well as structural information. The contrast agents Gd-DTPA, Gd-DOTA and Gd-BT-DO3A showed a high stability in irradiation experiments applying a wavelength range from 220 nm to 500 nm. Nevertheless, the degradation of Gd-BOPTA as well as the formation of Gd-containing transformation products was observed by means of HILIC-ICP-MS. Matrix-dependent irradiation experiments showed a degradation of Gd-BOPTA down to 3% of the initial amount in purified water after 300 min, whereas the degradation was slowed down in drinking water and surface water. Furthermore, it was observed that the sum of species continuously decreased with proceeding irradiation in all matrices. After irradiation in purified water for 300 min only 16% of the sum of species was left. This indicates a release of Gd(III) ions from the complex in course of irradiation. HILIC-ESI-MS measurements revealed that the transformation products mostly resulted from O-dealkylation and N-dealkylation reactions. In good correlation with retention times, the majority of transformation products were found to be more polar than Gd-BOPTA itself. Based on accurate masses, sum formulas were obtained and structures could be proposed. PMID:26802476

  10. Effects of differential-inducing agents on the radiation response of human colon adenocarcinoma cells in vitro

    International Nuclear Information System (INIS)

    This study was undertaken to investigate, in depth, the radiation responses of two tumor subpopulations obtained from a heterogeneous human colon adenocarcinoma. Of particular interest were the effects of differentiation-inducing agents on these tumor cells in vitro. These two subpopulations were found to differ significantly in their intrinsic sensitivity to x-irradiation when exponentially growing control cells were irradiated with single doses of x-rays. However, no significant differences were found between the radiation responses of these two subpopulations in the plateau phase of growth. Clone D cells always expressed a greater amount of PLDR than clone a cells regardless of the nutritional state examined. The magnitude of expression of sublethal damage recovery (SLDR) was the same for both cell lines. The effects of the differentiating agents, N,N-dimethylformamide (DMF), sodium butyrate (NaB), 5-azacytidine (5-aza-CR), and 5-aza-2'-deoxycytidine (5-aza-CdR) on intrinsic radiosensitivity and recovery processes were investigated in plateau phase cultures treated with the agents for three passages in vitro. Using a typical clinical radiation dose of 2 Gy for comparison, both DMF and NaB enhanced radiation cell killing in the low dose (shoulder) region of the survival curves for both of the tumor subpopulations. These studies indicate that differentiation-inducing agents can significantly modify the radiation response of human tumor cells in vitro and the nature of these changes may impact strongly on any combined modality therapy involving their use

  11. Ionisation as indicator for cosmic ray acceleration

    CERN Document Server

    Schuppan, Florian; Fedrau, Natalie; Tjus, Julia Becker

    2014-01-01

    Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies $E\\lesssim 1\\,$TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of atomic and molecular hydrogen, can lead to observable signatures. A correlation study of both gamma ray emission, induced by proton-proton interactions of cosmic ray protons with kinetic energies $E_\\mathrm{p}\\ge 280\\,$MeV with ambient hydrogen, and ionisation induced by cosmic ray protons of kinetic energies $E_\\mathrm{p}< 280\\,$MeV can be performed in order to study potential sources of (sub)TeV cosmic rays.

  12. Critical ionisation velocity effects in astrophysical plasmas

    International Nuclear Information System (INIS)

    Critical ionisation velocity effects are relevant to astrophysical situations where neutral gas moves through a magnetised plasma. The experimental significance of the critical velocity is well established and the physical basis is now becoming clear. The underlying mechanism depends on the combined effects of electron impact ionisation and electron energisation by collective plasma interactions. For low density plasmas a theory based on a circular process involving electron heating through a modified two stream instability has been developed. Several applications of critical velocity effects to astrophysical plasmas have been discussed in the literature. The importance of the effect in any particular case may be determined from a detailed consideration of energy and momentum balance, using appropriate atomic rate coefficients and taking full account of collective plasma processes. (Auth.)

  13. {sup 166}Ho-chitosan as a radiation synovectomy agent - biocompatibility study of {sup 166}Ho-chitosan in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sug Jun; Lee, Soo Yong; Jeon, Dae Geun; Lee Jong Seok [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1997-01-01

    Radiation synovectomy is a noninvasive therapy that has been investigated as an alternative to surgical synovectomy. It is been successfully employed in the treatment of synovitis in rheumatoid arthrits and other inflammatory arthropathies. We developed the {sup 166}Ho-chitosan complex for possible use as a radiation synovectomy agent. Holmium is the more practical isotope based on its higher radioactivity and logner half-life. And isotope based on its higher radioactivity and logner half-life. And chitosan is ideal and suitable particles based on its soluble and biodegradable characteristics. So we investigated the biocompatibility of the {sup 166}Ho-chitosan complex to evaluated the suitability as a radiation synovectomy agent. In this study, we performed in vivo and in vitro stability test and biodistribution test. Our results indicate that {sup 166}Ho-chitosan may be an effective radiopharmaceutical for radiation synovectomy. (author). 30 refs., 7 tabs.

  14. 166Ho-chitosan as a radiation synovectomy agent - biocompatibility study of 166Ho-chitosan in rabbits

    International Nuclear Information System (INIS)

    Radiation synovectomy is a noninvasive therapy that has been investigated as an alternative to surgical synovectomy. It is been successfully employed in the treatment of synovitis in rheumatoid arthrits and other inflammatory arthropathies. We developed the 166Ho-chitosan complex for possible use as a radiation synovectomy agent. Holmium is the more practical isotope based on its higher radioactivity and logner half-life. And isotope based on its higher radioactivity and logner half-life. And chitosan is ideal and suitable particles based on its soluble and biodegradable characteristics. So we investigated the biocompatibility of the 166Ho-chitosan complex to evaluated the suitability as a radiation synovectomy agent. In this study, we performed in vivo and in vitro stability test and biodistribution test. Our results indicate that 166Ho-chitosan may be an effective radiopharmaceutical for radiation synovectomy. (author). 30 refs., 7 tabs

  15. Dedicated Trigger for Highly Ionising Particles at ATLAS

    CERN Document Server

    Katre, Akshay; The ATLAS collaboration

    2015-01-01

    In 2012, a novel strategy was designed to detect signatures of Highly Ionising Particles (HIPs) such as magnetic monopoles, dyons or Q-balls with ATLAS. A dedicated trigger was developed and deployed for proton-proton collisions at a centre of mass energy of 8 TeV. It uses the Transition Radiation Tracker (TRT) system, applying an algorithm distinct from standard tracking ones. The high threshold (HT) readout capability of the TRT is used to distinguish HIPs from other background processes. The trigger requires significantly lower energy depositions in the electromagnetic calorimeters and is thereby capable of probing a larger range of HIP masses and charges. A description of the algorithm for this newly developed trigger is presented, along with a comparitive study of its performance during the 2012 data-taking period with respect to previous efforts.

  16. Propionyl-L-carnitine as a potential protective agent against radiation-induced cardiotoxicity

    International Nuclear Information System (INIS)

    In this study, propiony-L-carnitine (PLC); a natural short-chain derivative of L-carnitine, has been tested as a potential protective agent against radiation-induced cardio-toxicity. Cardiotoxicity was assessed in the homo-genate of the heart by measuring the plasma levels of creatine phosphokinase (CPK), lactic acid dehydrogenase (LDH), aspartate aminotransferase (AST), as well as malon-dialdehyde (MDA), glutathione content (GSH), glutathione peroxidase (GSH-PX), superoxide dismutase (SOD), adenosine triphosphate (ATP) and nitric oxide (NO) production, whole body gamma-irradiation (2 and 6Gy ) of rats significantly increased CPK, LDH, AST,MDA, and NO and significantly decreased GSH,GSH-PX, SOD and ATP. Daily administration (one week) of PLC before whole body irradiation caused significant recovery for the serum enzyme CPK, LDH, AST and MDA, GSH, GSH-PX, SOD, ATP and NO levels in cardiac tissue. The protective effect PLC was attributed to it's antioxidant properties. Radiation therapy, likewise, is a valuable method of treatment for a variety of intrathoracic neoplasms. During radiotherapy of thoracic tumorus, the heart is often included in the primary treatment volume and chronic impairment of myocadial function occurs (cilliers and lochner, 1993; benderitter et al., 1995). Irradiation causes numerous changes in different metabolic reactions within the cardiac cells with major adverse undersirable effects that involve cardiotoxicity

  17. New therapeutic agent for radiation synovectomy - preparation of 166Ho-EDTMP-HA particle

    International Nuclear Information System (INIS)

    In order to prepare new therapeutical agent for radiation synovectomy, Hydroxyapatite (HA) was labelled with 166Ho by EDTMP that had high affinity to HA particles. Radiolabelling of HA particles was divided into two steps, 166Ho-EDTMP was prepared first; then mixed with HA particles completely and vibrated for 15 minutes on the micromixer at room temperature, washed 3 times with deionized water. Radiolabelling particle was separated from free 166Ho via centrifugation to determine its radiolabelling efficiency. 166Ho-EDTMP-HA and 166Ho-EDTMP were injected into knee joint of normal rabbits respectively, every group was killed at different time postinjection, took out major organ and collected urine and blood, then weighted and determined their radio counts. HA particles, as a natural component of bone was known to have good compatibility with soft tissue and biodegrade into calcium and phosphate in vivo. It was readily prepared from common chemical and formed into particles of desired size range in a controlled process, it had high stability in vitro and vivo. Radiolabelling of HA particle with 166Ho by EDTMP was simple to perform and provides an excellent labelling yield that was more than 95% under the optimal labelling condition. The optimal labelling condition at room temperature was pH 6.0-8.0 and vibration time 15 minutes. The absorbed capacity of HA particle was 5 mg Ho/g HA particle and size of radiolabelling particle was at range of 2-5,μm that is suitable for therapy of radiation synovectomy. 166Ho-EDTMP-HA particle demonstrated high in vitro stability in either normal saline or 1% BSA solution, but instability under extremely acidic condition (pH 1-2). The control studies performed with 166Ho-EDTMP not bound to HA particle provided information on the distribution of radioactivity that would occur upon leakage of the radiochemical compound from joint. Its short half-life, its extremely low leakage from the joint and its even distribution throughout the

  18. Environmental protection from ionising contaminants in the Arctic

    International Nuclear Information System (INIS)

    The traditional ICRP doctrine concerning environmental protection, in essence expressing that the dose limits in place for man ensure that flora and fauna are protected from the effects of ionising radiation, has been recently criticised. In its place, a system for the radiological protection of the environment has been promoted to include agreed quantities and units, selected reference organisms, reference dose models and tables of effects for reference organisms. The EC project 'Environmental Protection for Ionising Contaminants in the Arctic 'EPIC' adopts a practical perspective in developing a protection framework for the Arctic environment. The objectives of the project were:(1) collate the information about environmental transfer of selected radionuclides (2) identify reference Arctic biota; (3) model the uptake of radionuclides; (4) develop a reference set of dose models (5) compile data of dose-effects relationships for reference biota, and (6) integrate assessment of environmental impact from radionuclides with those for other contaminants. In the selection of reference organisms, several key criteria have been identified: ecological niche, radiosensitivity, radioecological sensitivity, distribution and amenability to further research. The application of these criteria has allowed an informed selection of suitable Arctic reference organisms to be made. Field studies were performed in the area of residual radioactive contamination in the Republic of Sakha, Yakutia. Biological material and soils were sampled, notes on plant morphology in elevated dose area were made, and seeds from high dose rate areas were sampled and tested for germination rate. A database on dose-effects relationships has been constructed. The database is subdivided into radiation effects on terrestrial and aquatic organisms. The database will help to establish dose-effect relationships for different end points. At present, effort has been concentrated on populating the database; In

  19. No evidence for large-scale outflows in the extended ionised halo of ULIRG Mrk273

    CERN Document Server

    Spence, R A W; Tadhunter, C N; Rose, M; Cabrera-Lavers, A; Spoon, H; Munoz-Tunon, C

    2016-01-01

    We present deep new GTC/OSIRIS narrow-band images and optical WHT/ISIS long-slit spectroscopy of the merging system Mrk273 that show a spectacular extended halo of warm ionised gas out to a radius of $\\sim45$ kpc from the system nucleus. Outside of the immediate nuclear regions (r > 6 kpc), there is no evidence for kinematic disturbance in the ionised gas: in the extended regions covered by our spectroscopic slits the emission lines are relatively narrow (FWHM $\\lesssim$ 350 km$\\rm s^{-1}$) and velocity shifts small (|$\\Delta$V| $\\lesssim{} $250 km$\\rm s^{-1}$). This is despite the presence of powerful near-nuclear outflows (FWHM > 1000 km$\\rm s^{-1}$; |$\\Delta$V| > 400 km$\\rm s^{-1}$; r < 6 kpc). Diagnostic ratio plots are fully consistent with Seyfert 2 photo-ionisation to the NE of the nuclear region, however to the SW the plots are more consistent with low-velocity radiative shock models. The kinematics of the ionised gas, combined with the fact that the main structures are aligned with low-surface-bri...

  20. Nanodosimetry, from radiation physics to radiation biology.

    Science.gov (United States)

    Grosswendt, B

    2005-01-01

    In view of the fact that early damage to genes and cells by ionising radiation starts with the early damage to segments of the DNA, it is a great challenge to radiation research to describe the general behaviour of ionising radiation in nanometric target volumes (nanodosimetry). After summarising basic aspects of nanodosimetry, an overview is given about its present state. As far as experimental procedures are concerned, main emphasis is laid on single-ion counting and single-electron counting methods, which use millimetric target volumes filled with a low-pressure gas to simulate nanometric target volumes at unit density. Afterwards, physical principles are discussed, which can be used to convert experimental ionisation cluster-size distributions into those caused by ionising radiation in liquid water. In the final section, possibilities are analysed of how to relate parameters derived from the probability of cluster-size formation in liquid water to parameters derived from radiobiological experiments. PMID:16381675

  1. Nanodosimetry, from radiation physics to radiation biology

    International Nuclear Information System (INIS)

    In view of the fact that early damage to genes and cells by ionising radiation starts with the early damage to segments of the DNA, it is a great challenge to radiation research to describe the general behaviour of ionising radiation in nano-metric target volumes (nanodosimetry). After summarising basic aspects of nanodosimetry, an overview is given about its present state. As far as experimental procedures are concerned, main emphasis is laid on single-ion counting and single-electron counting methods, which use millimetric target volumes filled with a low-pressure gas to simulate nano-metric target volumes at unit density. Afterwards, physical principles are discussed, which can be used to convert experimental ionisation cluster-size distributions into those caused by ionising radiation in liquid water. In the final section, possibilities are analysed of how to relate parameters derived from the probability of cluster-size formation in liquid water to parameters derived from radiobiological experiments. (authors)

  2. Report of National Cancer Institute symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. I. Common molecular mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Borg, D.C.

    1984-01-01

    Some aspects of molecular mechanisms common to radiation and chemical carcinogenesis are discussed, particularly the DNA damage done by these agents. Emphasis is placed on epidemiological considerations and on dose-response models used in risk assessment to extrapolate from experimental data obtained at high doses to the effects from long-term, low-level exposures. 3 references, 6 figures. (ACR)

  3. Combined effect of gamma radiation and some fungal control agents on the greasy cut- worm

    International Nuclear Information System (INIS)

    The greasy cut worm, Agrotis ipsilon (Lepidoptera- Noctuidae) is widely distributed all over the world, particularly in moderate and subtropical countries of the northern and southern hemispheres (Kononenko ,2003). The greasy cut worm causes damage to vegetables, cucurbitaceous and industrial crops. The greatest damage is caused to cotton, essential-oil cultures, maize, tobacco, sunflower, tomatoes, sugar beet and potato. The pest can strongly harm vegetables, and also damage seedlings of tree species (pine, maple, and nut). This pest has solitary habits. They commonly feed on seedlings at ground level, cutting off the stem and sometimes dragging the plants into their burrows. The continuous use of chemical pesticides against pests, resistance to the action of pesticides had dramatically evolved. Also, the extensive use of these chemicals has given rise to problems such as residual toxicity (pollution) and harmful effects on beneficial insects, which are natural enemies of target or nontarget pest species. Such problems have become a cause of search for safety pesticides including microbial agents as fungi, bacteria and viruses (Rashed, 1993). The use of radiation to induce dominate lethal mutations in the sterile insect technique (SIT) is now as the major component of many large and successful programs for pest suppression and eradication. Adult insects, and their different developmental stages, differ in their sensitivity to the induction of dominate lethal mutation. Care has to be taken to identify the appropriate dose of radiation that produces the required level of sterility without impairing the overall fitness of the released insects.(Sawires, 2005). This technique would be successful control device for suppressing and combating many lepidopteraus insect pests, including A. Ipsilon has been studied (EL- kady et al., 1983, EL-Naggar et al., 1984, Abd El -Hamid 2004 and Gabarty, 2008). Entomopathogenic fungi that infect insects have received considerable

  4. International Atomic Energy Agency Regional Workshop on Commercialisation of ionising energy treatment of food: proceedings

    International Nuclear Information System (INIS)

    The global need to ensure adequate food supplies places a demand on new technologies and techniques to improve yields and preservation of food by eliminating or reducing bacterial degradation and infestation of raw or processed foods. The use of ionising radiation in food processing also has potential to alleviate certain food-borne diseases which cause serious threats to the health of people in many countries

  5. Pharmacological toxicological studies on certain drugs subjected to radiation or used radioprotective agents

    International Nuclear Information System (INIS)

    The present study represents two main subjects. The first encounters the effect of radiosterilization of certain pharmaceretical preparations such as antihistaminics (cimetidine), anticonvulsants (diazepam), beta and calcium channel blacker (propranolol and verapamil) on their pharmacological activity. Results of this study revealed that the previously mentioned drugs can be effectively and safely sterilized by gamma irradiation without deleterious effect on their pharmacological activity. The other subject presented in this study is essentially a pharmacological subject encountering toxicological problems. Data of this study demonstrated that chemical radiation protection has been successfully reported using single drug administration has been successfully reported using single drug administration such as imidazole, and Sh-bearing compounds. In the present work, the radioprotective effect of imidazole was demonstrated on the cardiovascular and respiratory systems. Furthermore, combined drug administration was found to exert more protective action with less toxicity and therefore minimize the side effects of the radioprotective drugs. Thus, combination of imidazole and serotonin showed potential protective effect on blood gases was also reported. In addition, combination of cysteine and vitamin E afforded a better protection on adrenocortical function in rats than either agent alone. 4 figs., 1 tab

  6. Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: Study protocol

    NARCIS (Netherlands)

    M. Gallastegi (Mara); M. Guxens (Mònica ); A. Jiménez-Zabala (Ana); I. Calvente (Irene); M. Fernández (Marta); L. Birks (Laura); B. Struchen (Benjamin); M. Vrijheid (Martine); M. Estarlich (Marisa); M.F. Fernandez (Mariana); M. Torrent (Maties); F. Ballester (Ferran); J.J. Aurrekoetxea (Juan José); J. Ibarluzea (Jesús); D. Guerra (David); J. González (Julián); M. Röösli (Martin); L. Santa-Marina (Loreto)

    2016-01-01

    textabstractBackground: Analysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR) and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol de

  7. Ionising energy treatment of fresh fruit

    International Nuclear Information System (INIS)

    The main purposes of the ionising energy treatment of fresh fruit are: the extension of shelf life of the commodity due to a direct physiological effect on the particular product; the extension of shelf life of the commodity due to a reduction in the development of moulds and rots which would normally render the product worthless; and the killing of insect pests of quarantine significance, to allow for normal marketing of fresh fruit without the risk of introducing insect pests to previously pest-free areas

  8. Realisation of dosimetric studies for workplaces with a risk of exposure to ionizing radiations (version 2). Practical guide; Realisation des etudes dosimetriques de poste de travail presentant un risque d'exposition aux rayonnements ionisants (version 2). Guide pratique

    Energy Technology Data Exchange (ETDEWEB)

    Donadille, L.; Rehel, J.L.; Deligne, J.M.; Queinnec, F.; Aubert, B.; Bottollier-Depois, J.F.; Clairand, I.; Jourdain, J.R.; Rannou, A.

    2010-07-01

    This guide proposes a methodological approach to help carry out dosimetric workplace studies complying with the french regulation, and necessary to identify risks of radiological exposure, optimize radiation protection, classify the workers into different categories and the workplaces into different areas. Additional information is provided relating the main objectives of a workplace study, the French regulatory context, main sources and pathways of exposure to ionizing radiation. Radiation protection and operational quantities are reminded. Recommendations about the selection and use of detectors and about the implementation of calculation methods are also provided. The general methodological approach is applied and developed into 'workplace sheets', each one devoted to a particular type of workplace. (authors)

  9. Cosmic-ray ionisation in collapsing clouds

    CERN Document Server

    Padovani, Marco; Galli, Daniele

    2013-01-01

    Cosmic rays (CR) play an important role in dense molecular cores, affecting their thermal and dynamical evolution and initiating the chemistry. Several studies have shown that the formation of protostellar discs in collapsing clouds is severely hampered by the braking torque exerted by the entrained magnetic field on the infalling gas, as long as the field remains frozen to the gas. We examine the possibility that the concentration and twisting of the field lines in the inner region of collapse can produce a significant reduction of the ionisation fraction. To check whether the CR ionisation rate (CRir) can fall below the critical value required to maintain good coupling, we first study the propagation of CRs in a model of a static magnetised cloud varying the relative strength of the toroidal/poloidal components and the mass-to-flux ratio. We then follow the path of CRs using realistic magnetic field configurations generated by numerical simulations of a rotating collapsing core. We find that an increment of...

  10. Detection of ionizing radiations with the SOS chromotest, a bacterial short-term test for genotoxic agents

    International Nuclear Information System (INIS)

    The effects if 3 type of ionizing radiation, γ-rays, neutrons and accelerated α-particles, were examined usingthe SOS Chromotest, a bacterial colorimetric assay for genotoxic agents besed on the measurement of the SOS response in Escherichia coli. The SOS Chromotest appeared to be a sensitive and simple assay to detect quantitatively these radiations as well as their biological effects. The range of adsorbed doses for which induction was observed was similar for the 3 types of radiation, the minimum inducing doses deing in the order of 2.5-5 Gy. We discuss the possible use of these observation to study the molecular action of radiations and to compare their genotoxic effects with those of chemicals. (Author). 43 refs.; 1 fig.; 1 tab

  11. Time-dependent hydrogen ionisation in the solar chromosphere. I: Methods and first results

    CERN Document Server

    Wedemeyer-Boehm, J L S

    2006-01-01

    An approximate method for solving the rate equations for the hydrogen populations was extended and implemented in the three-dimensional radiation (magneto-)hydrodynamics code CO5BOLD. The method is based on a model atom with six energy levels and fixed radiative rates. It has been tested extensively in one-dimensional simulations. The extended method has been used to create a three-dimensional model that extends from the upper convection zone to the chromosphere. The ionisation degree of hydrogen in our time-dependent simulation is comparable to the corresponding equilibrium value up to 500 km above optical depth unity. Above this height, the non-equilibrium ionisation degree is fairly constant over time and space, and tends to be at a value set by hot propagating shock waves. The hydrogen level populations and electron density are much more constant than the corresponding values for statistical equilibrium, too. In contrast, the equilibrium ionisation degree varies by more than 20 orders of magnitude between...

  12. Dexamethasone-induced enhancement of resistance to ionizing radiation and chemotherapeutic agents in human tumor cells

    International Nuclear Information System (INIS)

    Background: Dexamethasone-induced changes in radioresistance have previously been observed by several authors. Here, we examined effects of dexamethasone on resistance to ionizing radiation in 10 additional human cell lines and strains, and on resistance to carboplatin and paclitaxel in 13 fresh tumor samples. Material and Methods: Eight human carcinoma cell lines, a glioblastoma cell line and a strain of normal human diploid fibroblasts were arbitrarily chosen for these in-vitro studies. Effects on radiosensitivity were assessed using a conventional colony formation assay. Effects on resistance to the drugs were investigated prospectively (ATP cell viability assay) using 13 fresh tumor samples from consecutive patients operated for ovarian cancer within the context of a Swiss nation-wide randomized prospective clinical trial (SAKK 45/94). Results: Dexamethasone promoted proliferation of 1 of the cell lines without affecting radiosensitivity, while it completely inhibited proliferation of another cell line (effects on radiosensitivity could thus not be examined). Furthermore, dexamethasone induced enhanced radioresistance in 1 of the 8 carcinoma cell lines examined. In the glioblastoma cell line, there was no effect on growth or radioresistance, nor in the fibroblasts. Treatment with dexamethasone enhanced resistance of the malignant cells to carboplatin in 4 of the 13 fresh tumor samples examined, while no enhancement in resistance to paclitaxel was observed. Conclusions: In agreement with previous reports, we found that dexamethasone may induce radioresistance in human carcinoma cells. Including the published data from the literature, dexamethasone induced enhancement in radioresistance in 4 of 12 carcinoma cell lines (33%), but not in 3 glioblastoma cell lines, nor in 3 fibroblast strains. Dexamethasone also induced enhanced resistance to carboplatin with a similar probability in fresh samples of ovarian cancer evaluated prospectively (in 4 of 13 samples; 31

  13. Exposure of the french population to ionizing radiation link to medical diagnosis act in 2007; Exposition de la population francaise aux rayonnements ionisants liee aux actes de diagnostic medical en 2007

    Energy Technology Data Exchange (ETDEWEB)

    Etard, C.; Aubert, B. [Institut de Radioprotection et de Surete Nucleaire, 92 - Clamart (France); Sinno-Tellier, S. [Institut de Veille Sanitaire, 94 - Saint Maurice (France)

    2010-07-01

    The objective of this report is to update and complete the data relative to the medical exposure of the French population to diagnostic imaging examinations for the year 2007. The last published data correspond to the year 2002. The information supplied by this report precise: the medical exposure to diagnostic imaging examinations by imaging modality (conventional radiology, scanner, nuclear medicine, and diagnostic interventional imaging), by anatomical area, by age, and according to the sex of the patient and it also the part of the French population (strength, age, sex) who actually benefited of diagnostic acts using ionizing radiation in 2007. In 2007, 74.6 millions of diagnostic acts using ionizing radiation have been realised in france. These acts induce for the year 2007 to an efficient average dose of 1.3 MSv. (N.C.)

  14. Outcomes of children with central nervous system germinoma treated with multi-agent chemotherapy followed by reduced radiation.

    Science.gov (United States)

    Cheng, Sylvia; Kilday, John-Paul; Laperriere, Normand; Janzen, Laura; Drake, James; Bouffet, Eric; Bartels, Ute

    2016-03-01

    CNS germinomas have an excellent prognosis with radiation therapy alone. However, in children, volume and dose of CNS radiation are associated with neurocognitive and neuroendocrine sequelae. Our objective was to determine long-term outcomes of our cohort who received chemotherapy and reduced radiation. This retrospective cohort study analyzed treatment and outcome of intracranial germinoma patients consecutively treated at Sick Kids, Toronto, Canada, from January 2000 to December 2013. 24 children (13 male, 11 female; median age 13.36 years) were identified. Median follow up was 61 months (range 1-144 months). Tumor location was suprasellar (n = 9), bifocal (8), pineal (6), and basal ganglia (1). Three children showed dissemination on imaging. 2/24 had only elevated serum human chorionic gonadotropin, 3/24 only elevated lumbar cerebrospinal fluid (CSF) hCG, and 2/24 had both elevated serum and lumbar CSF hCG. 23/24 children completed treatment and received multi-agent chemotherapy followed by either ventricular radiation (2340-2400 cGy) (n = 9), ventricular radiation + boost (1600 cGy) (n = 8), whole brain (2340 cGy) (n = 3), focal (4000 cGy) (n = 2) or craniospinal radiation (2340 cGy) (n = 1). Five-year progression free and overall survival was 96 and 100 % respectively. 8/24 patients with ventricular radiation ± boost (2340/4000 cGy) displayed stable full scale intelligence quotient over a mean interval of 3 years following radiation, but showed declined processing speed. In this limited experience, excellent 5-year overall survival rates were achieved with chemotherapy followed by reduced whole ventricular radiation even if ventricular radiation was delivered without boost. PMID:26744133

  15. Ionizing radiation sources: very diversified means, multiple applications and a changing regulatory environment. Conference proceedings; Les sources de rayonnements ionisants: des moyens tres diversifies, des applications multiples et une reglementation en evolution. Recueil des presentations

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-11-15

    This document brings together the available presentations given at the conference organised by the French society of radiation protection about ionizing radiation source means, applications and regulatory environment. Twenty eight presentations (slides) are compiled in this document and deal with: 1 - Overview of sources - some quantitative data from the national inventory of ionizing radiation sources (Yann Billarand, IRSN); 2 - Overview of sources (Jerome Fradin, ASN); 3 - Regulatory framework (Sylvie Rodde, ASN); 4 - Alternatives to Iridium radiography - the case of pressure devices at the manufacturing stage (Henri Walaszek, Cetim; Bruno Kowalski, Welding Institute); 5 - Dosimetric stakes of medical scanner examinations (Jean-Louis Greffe, Charleroi hospital of Medical University); 6 - The removal of ionic smoke detectors (Bruno Charpentier, ASN); 7 - Joint-activity and reciprocal liabilities - Organisation of labour risk prevention in case of companies joint-activity (Paulo Pinto, DGT); 8 - Consideration of gamma-graphic testing in the organization of a unit outage activities (Jean-Gabriel Leonard, EDF); 9 - Radiological risk control at a closed and independent work field (Stephane Sartelet, Areva); 10 - Incidents and accidents status and typology (Pascale Scanff, IRSN); 11 - Regional overview of radiation protection significant events (Philippe Menechal, ASN); 12 - Incident leading to a tritium contamination in and urban area - consequences and experience feedback (Laurence Fusil, CEA); 13 - Experience feedback - loss of sealing of a calibration source (Philippe Mougnard, Areva); 14 - Blocking incident of a {sup 60}Co source (Bruno Delille, Salvarem); 15 - Triggering of gantry's alarm: status of findings (Philippe Prat, Syctom); 16 - Non-medical electric devices: regulatory changes (Sophie Dagois, IRSN; Jerome Fradin, ASN); 17 - Evaluation of the dose equivalent rate in pulsed fields: method proposed by the IRSN and implementation test (Laurent Donadille

  16. Alteration of the digestive motility linked with radiation-induced inflammatory processes in rats; Alterations de la motricite digestive associees aux processus inflammatoires induits par les rayonnements ionisants chez le rat

    Energy Technology Data Exchange (ETDEWEB)

    Picard, C

    2000-12-01

    Exposure to ionizing radiation, whether accidental or for medical reasons, may lead to gastro-intestinal injury, characterized by nausea, vomiting, diarrhea and abdominal cramps. The aetiology of radiation-induced diarrhea remains to date unclear. In this study, we have investigated the acute effects of a 10 Gy abdominal irradiation on rat digestive functions. The objective of the first study was to evaluate the role of sensory afferent neurons, capsaicin-sensitive, on morphological changes and the inflammatory response following exposure. Three days after irradiation, we observed an inflammatory response characterized by neutrophils infiltration and mast cells de-granulation. No effect of capsaicin pre-treatment was seen on these parameters. However, neutrophils infiltration was increased as early as one day after irradiation in capsaicin-treated rats. No difference in severity of diarrhea was observed after denervation nor in morphological changes. These data demonstrate that abdominal irradiation results in diarrhea concomitant with an inflammatory response, and that sensory innervation does not play a major protective role. The objective of the rest of the work was in the first instance to characterize radiation-induced alterations of intestinal and colonic motility leading to diarrhea and secondly to evaluate the role of serotonin in such disorders. Perturbations in intestinal (MMC) and colonic (LSB) motor profiles were observed from the first day onwards. Migrating motor complexes (MMC) were completely disrupted at three days at the same time as the onset of diarrhea. In addition to inhibition of LSB, colonic fluid absorptive capacity was decreased and serotonin colonic tissue levels were increased three days after irradiation. Radiation-induced diarrhea was reduced by treatment with an antagonist of 5-HT{sub 3} receptors, granisetron, as were alterations of colonic motility and serotonin tissue levels. However, this treatment did not significantly ameliorate

  17. Development of an optical digital ionisation chamber

    International Nuclear Information System (INIS)

    We are developing a new device for optically detecting and imaging the track of a charged particle in a gas. The electrons in the particle track are made to oscillate rapidly by the application of an external, short duration, high voltage, RF electric field. The excited electrons produce additional ionisation and electronic excitation of the gas molecules in their immediate vicinity, leading to copious light emission (fluorescence) from the selected gas, allowing the location of the electrons along the track to be determined. Two digital cameras simultaneously scan the emitted light across two perpendicular planes outside the chamber containing the gas. The information thus obtained for a given track can be used to infer relevant quantities for microdosimetry and dosimetry, e.g. energy deposited, LET, and track structure in the gas. The design of such a device now being constructed and methods of obtaining the dosimetric data from the digital output will be described. (author)

  18. The need for radiation protection of the patient

    International Nuclear Information System (INIS)

    Radiation protection of the patient is an important issue for a number of different reasons. These include the nature of ionising radiation itself, its long term effects on tissue, the size of the population dose from medical work, and certain economic factors. Legislation in the UK requires staff concerned with ionising radiations to be properly trained. (Author)

  19. Effects of the electric field on ionisation in two different types of ionisation chambers

    International Nuclear Information System (INIS)

    A parallel plate cavity ionisation chamber was irradiated with 60Co γ rays from the polarising electrode. Beyond the recombinations region, the output current of the chamber increases (decreases) linearly with applied positive (negative) voltage. This effect is attributed to the change in the stopping power of air due to acceleration or deceleration of secondary electrons in the applied electric field. In a free-air ionisation chamber, secondary electrons emitted in the direction of the electric field lose energy and those emitted in the opposite direction gain energy and, hence, cause a reduction or enhancement in ionisation, respectively. Computer calculations have shown that the enhancement and reduction are in a range from 0.15 to 0.3% when exposure is measured for X rays generated at a tube voltage of 60-300 kV and at an electric field strength of 20 KV.m-1. The net increase in the output current change at this field strength is smaller than the calculation uncertainties. (author)

  20. Development of Antioxidant COX-2 Inhibitors as Radioprotective Agents for Radiation Therapy-A Hypothesis-Driven Review.

    Science.gov (United States)

    Laube, Markus; Kniess, Torsten; Pietzsch, Jens

    2016-01-01

    Radiation therapy (RT) evolved to be a primary treatment modality for cancer patients. Unfortunately, the cure or relief of symptoms is still accompanied by radiation-induced side effects with severe acute and late pathophysiological consequences. Inhibitors of cyclooxygenase-2 (COX-2) are potentially useful in this regard because radioprotection of normal tissue and/or radiosensitizing effects on tumor tissue have been described for several compounds of this structurally diverse class. This review aims to substantiate the hypothesis that antioxidant COX-2 inhibitors are promising radioprotectants because of intercepting radiation-induced oxidative stress and inflammation in normal tissue, especially the vascular system. For this, literature reporting on COX inhibitors exerting radioprotective and/or radiosensitizing action as well as on antioxidant COX inhibitors will be reviewed comprehensively with the aim to find cross-points of both and, by that, stimulate further research in the field of radioprotective agents. PMID:27104573

  1. Development of Antioxidant COX-2 Inhibitors as Radioprotective Agents for Radiation Therapy—A Hypothesis-Driven Review

    Directory of Open Access Journals (Sweden)

    Markus Laube

    2016-04-01

    Full Text Available Radiation therapy (RT evolved to be a primary treatment modality for cancer patients. Unfortunately, the cure or relief of symptoms is still accompanied by radiation-induced side effects with severe acute and late pathophysiological consequences. Inhibitors of cyclooxygenase-2 (COX-2 are potentially useful in this regard because radioprotection of normal tissue and/or radiosensitizing effects on tumor tissue have been described for several compounds of this structurally diverse class. This review aims to substantiate the hypothesis that antioxidant COX-2 inhibitors are promising radioprotectants because of intercepting radiation-induced oxidative stress and inflammation in normal tissue, especially the vascular system. For this, literature reporting on COX inhibitors exerting radioprotective and/or radiosensitizing action as well as on antioxidant COX inhibitors will be reviewed comprehensively with the aim to find cross-points of both and, by that, stimulate further research in the field of radioprotective agents.

  2. Report on NCI symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. II. Cellular and animal models

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1984-01-01

    The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could be demonstrated after exposure to low-LET radiation but not after exposure to chemical carcinogens.

  3. Report on NCI symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. II. Cellular and animal models

    International Nuclear Information System (INIS)

    The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could be demonstrated after exposure to low-LET radiation but not after exposure to chemical carcinogens

  4. Application to the Department of Health for clearance for the unlimited sale of potatoes treated with ionising radiation for the purpose of extending the storage lifetime of this commodity

    International Nuclear Information System (INIS)

    Potatoes were chosen as the subject of the first petition to the South African Department of Health for unlimited clearance for sale of an irradiated foodstuff in the Republic. This 'model' foodstuff was selected as it has been thoroughly tested overseas and proved to be perfectly safe for consumption. This report consists of the resulting petition, which includes a description of the need for, and advantages of, the radiation treatment, results of technological studies to confirm that the process is applicable under South African conditions, and detailed wholesomeness studies carried out in other countries. Acceptance of the petition by the Minister of Health is presented as an Appendix to the report. It is intended that future petitions for clearance of other foodstuffs will follow the pattern set in this document

  5. Amifostine, a radioprotectant agent, protects rat brain tissue lipids against ionizing radiation induced damage: An FTIR microspectroscopic imaging study

    Energy Technology Data Exchange (ETDEWEB)

    Cakmak G.; Miller L.; Zorlu, F.; Severcan, F.

    2012-03-03

    Amifostine is the only approved radioprotective agent by FDA for reducing the damaging effects of radiation on healthy tissues. In this study, the protective effect of amifostine against the damaging effects of ionizing radiation on the white matter (WM) and grey matter (GM) regions of the rat brain were investigated at molecular level. Sprague-Dawley rats, which were administered amifostine or not, were whole-body irradiated at a single dose of 800 cGy, decapitated after 24 h and the brain tissues of these rats were analyzed using Fourier transform infrared microspectroscopy (FTIRM). The results revealed that the total lipid content and CH{sub 2} groups of lipids decreased significantly and the carbonyl esters, olefinic=CH and CH{sub 3} groups of lipids increased significantly in the WM and GM after exposure to ionizing radiation, which could be interpreted as a result of lipid peroxidation. These changes were more prominent in the WM of the brain. The administration of amifostine before ionizing radiation inhibited the radiation-induced lipid peroxidation in the brain. In addition, this study indicated that FTIRM provides a novel approach for monitoring ionizing radiation induced-lipid peroxidation and obtaining different molecular ratio images can be used as biomarkers to detect lipid peroxidation in biological systems.

  6. RADIATION AND EFFECTS ON HUMAN HEALTH

    Directory of Open Access Journals (Sweden)

    Hakan YAREN

    2005-08-01

    Full Text Available In modern world, living without radiation is impossible. Radiation is defined as ?energy transmitted through space as waves or particles? and also determined as ?particles or waves emitted from the nucleus of unstable radioactive atoms to become stable? Mainly two types of radiation are exist; ionising radiation and non-ionising radiation. Ionising radiation is consist of alpha, beta particules, neutrons, x rays and gamma rays. Ionising radiation which can be measured by ion chambers, geiger-Mueller detectors, Scintillation Counters, fluorescent counters etc. Has harmfull effects on human health in levels of molecular, cellular, tissue, organs and organ systems. These harmfull effects can also be named somatic and genetic. One of the most encountered problem is ?Acute Radiation Syndrom? which has three sub syndroms called haematopoetic syndrom, gastrointestinal syndrom and neurovascular syndrom. Exposure time, distance and armorisation are the key elements of protection from radiation. [TAF Prev Med Bull 2005; 4(4.000: 199-208

  7. Integrated effect of gamma radiation and biocontrol agent on quality parameters of apple fruit: An innovative commercial preservation method

    International Nuclear Information System (INIS)

    Effects of gamma irradiation and biocontrol agent (Pseudomonas fluorescens) on the physico-chemical parameters (including moisture, total soluble solids, antioxidant activity, phenolic content and firmness) of cv. Golden Delicious apples were investigated for their ability to avoid the post-harvest blue mold caused by Penicillium expansum during cold storage. Freshly harvested apples were inoculated with P. expansum. Treated fruits were irradiated at doses of 0, 200, 400, 600 and 800 Gy and then inoculated with P. fluorescens suspension. Samples were evaluated at 3 month intervals. The results demonstrated a clear link between antioxidant activity and phenolic content, so that dose range of 200–400 Gy significantly increased phenolic content and antioxidant activity. Effect of P. fluorescens was similar to irradiation at 200 and 400 Gy that could prevent lesion diameter in pathogen-treated apples. As dose and storage time increased firmness decreased but, combination of P. fluorescens as well as irradiation (at 200–400 Gy) could decrease softening apple fruits during storage. In all parameters, P. fluorescens (as biocontrol agent) inhibited P. expansum similar to irradiation at 200–400 Gy. So, integrated treatment of irradiation and biocontrol agent explored the potential dual benefit of low doses (200 and 400 Gy) as a suitable method to sustain physico-chemical quality and conclusively reduce apple fruits losses during post-harvest preservation. - Highlights: • A suitable method to reduce apple quality losses during 9 month storage period. • Effects of γ radiation in combination with biocontrol agent on physico-chemical parameters of the apple fruits during cold storage. • The potential dual benefit of low irradiation dose combined with biocontrol agent. • Radiation dose determination for Penicillium expansum (postharvest pathogen) control

  8. Innershell ionisation at small impactparameters in proton-atom collisions

    International Nuclear Information System (INIS)

    This thesis concentrates on innershell ionisation in proton-atom collisions. An experiment on K-shell ionisation of argon is described, performed in a gasfilled collision chamber under single collision conditions. Further experiments with carbon and aluminium were performed, the K-shell vacancy production in the collision of protons with these atoms being detected through the measurement of Auger-electrons. A spectrometer with a large solid angle was specially constructed for this and its performance is described. K-shell ionisation accompanying nuclear (p,γ) reactions has also been measured using 26Mg and 27Al. (Auth./C.F.)

  9. The effects of radioprotective agents on the radiation-induced DNA single strand breaks

    International Nuclear Information System (INIS)

    With the increased use of atomic energy in science, industry, medicine and public power production, the probability of nuclear accidents certainly appears to be on the increase. Therefore, early medical diagnosis and first-aid are needed urgently to establish an efficient treatment. We carried out the studies of radiation protector such as DDC, MEA, WR-2721 and variety of decontaminator with a view to establishing the protective measure and diagnostic standards for safety of worker and neighbors living around the radiation area in case of occurring the accidental contamination. In this experiment, we examined radiation-induced DNA single strand breaks as one of the study on molecular biology of the response of cells to radiation because an understanding of the radiation-induced damage in molecular level would add to our knowledge of radiation protection and treatment. (Author)

  10. A detailed study of the pulse height deficit effect in gas ionisation detectors

    International Nuclear Information System (INIS)

    Full text: Gas ionisation detectors were originally developed for nuclear physics applications but have more recently also found use in nuclear techniques of analysis such as accelerator mass spectrometry (AMS) and ion beam analysis (IBA). They are ideal for heavy ion detection primarily because they do not suffer from radiation damage. It is well known that the pulse height versus energy relation for gas ionization detectors is non-linear. Previous studies have established that this is due to a pulse height deficit effect, which increases with both the atomic number and energy of the detected ion, and is of the order of 5 - 8MeV for typical fission fragment energies and masses. Published data does not, however, provide accurate estimates of the size of this effect for the wide range of ion species and energies applicable to materials analysis applications such as heavy ion elastic recoil detection (HIERDA), nor does it provide complete understanding of the factors which contribute to the effect. This presentation reports on a detailed study of the pulse height deficit effect, undertaken at the ANU 14UD pelletron accelerator facility using a propane-filled gas ionisation detector. Results will be presented quantifying the size of the pulse height deficit for a variety of ion species and energies. Furthermore, it will be demonstrated that a significant residual pulse height deficit remains after accounting for energy loss in the detector window, and non-ionising energy loss processes in the detector gas

  11. The First Billion Years Project: The escape fraction of ionising photons in the epoch of reionisation

    CERN Document Server

    Paardekooper, Jan-Pieter; Vecchia, Claudio Dalla

    2015-01-01

    Proto-galaxies forming in low-mass dark matter haloes are thought to provide the majority of ionising photons needed to reionise the Universe, due to their high escape fractions of ionising photons. We study how the escape fraction in high-redshift galaxies relates to the physical properties of the halo in which the galaxies form by computing escape fractions for 75801 haloes between redshifts 27 and 6 that were extracted from the FiBY project, high-resolution cosmological hydrodynamics simulations of galaxy formation. We find that the main constraint on the escape fraction is the presence of dense gas within 10 pc of the young sources that emit the majority of the ionising photons produced over the lifetime of the stellar population. This results in a strong mass dependence of the escape fraction. The lower potential well in haloes with virial mass below 10^8 solar mass results in lower column densities close to the sources that can be penetrated by the radiation from young, massive stars. In general only a ...

  12. Dedicated Trigger for Highly Ionising Particles at ATLAS

    CERN Document Server

    Katre, Akshay; The ATLAS collaboration

    2015-01-01

    In 2012, a novel strategy was designed to detect signatures of Highly Ionising Particles (HIPs) such as magnetic monopoles, dyons or Qballs with the ATLAS trigger system. With proton-proton collisions at a centre of mass enegy of 8 TeV, the trigger was designed to have unique properties as a tracker for HIPs. It uses only the Transition Radiation Tracker (TRT) system, applying an algorithm distinct from standard tracking ones. The unique high threshold readout capability of the TRT is used at the location where HIPs in the detector are looked for. In particular the number and the fraction of TRT high threshold hits is used to distinguish HIPs from background processes. The trigger requires significantly lower energy depositions in the electro-magnetic calorimeters as a seed unlike previously used trigger algorithms for such searches. Thus the new trigger is capable of probing a large range of HIP masses and charges. We will give a description of the algorithms for this newly developed trigger for HIP searches...

  13. Ionisation and discharge in cloud-forming atmospheres of brown dwarfs and extrasolar planets

    Science.gov (United States)

    Helling, Ch; Rimmer, P. B.; Rodriguez-Barrera, I. M.; Wood, Kenneth; Robertson, G. B.; Stark, C. R.

    2016-07-01

    Brown dwarfs and giant gas extrasolar planets have cold atmospheres with rich chemical compositions from which mineral cloud particles form. Their properties, like particle sizes and material composition, vary with height, and the mineral cloud particles are charged due to triboelectric processes in such dynamic atmospheres. The dynamics of the atmospheric gas is driven by the irradiating host star and/or by the rotation of the objects that changes during its lifetime. Thermal gas ionisation in these ultra-cool but dense atmospheres allows electrostatic interactions and magnetic coupling of a substantial atmosphere volume. Combined with a strong magnetic field \\gg {{B}\\text{Earth}} , a chromosphere and aurorae might form as suggested by radio and x-ray observations of brown dwarfs. Non-equilibrium processes like cosmic ray ionisation and discharge processes in clouds will increase the local pool of free electrons in the gas. Cosmic rays and lighting discharges also alter the composition of the local atmospheric gas such that tracer molecules might be identified. Cosmic rays affect the atmosphere through air showers in a certain volume which was modelled with a 3D Monte Carlo radiative transfer code to be able to visualise their spacial extent. Given a certain degree of thermal ionisation of the atmospheric gas, we suggest that electron attachment to charge mineral cloud particles is too inefficient to cause an electrostatic disruption of the cloud particles. Cloud particles will therefore not be destroyed by Coulomb explosion for the local temperature in the collisional dominated brown dwarf and giant gas planet atmospheres. However, the cloud particles are destroyed electrostatically in regions with strong gas ionisation. The potential size of such cloud holes would, however, be too small and might occur too far inside the cloud to mimic the effect of, e.g. magnetic field induced star spots.

  14. Consideration of measurement errors in the analysis of the risk related to the exposure to ionising radiation in an occupational cohort: application to the French cohort of uranium miners

    International Nuclear Information System (INIS)

    In epidemiological studies, measurement errors in exposure can substantially bias the estimation of the risk associated to exposure. A broad variety of methods for measurement error correction has been developed, but they have been rarely applied in practice, probably because their ability to correct measurement error effects and their implementation are poorly understood. Another important reason is that many of the proposed correction methods require to know measurement errors characteristics (size, nature, structure and distribution). The aim of this thesis is to take into account measurement error in the analysis of risk of lung cancer death associated to radon exposure based on the French cohort of uranium miners. The mains stages were (1) to assess the characteristics (size, nature, structure and distribution) of measurement error in the French uranium miners cohort, (2) to investigate the impact of measurement error in radon exposure on the estimated excess relative risk (ERR) of lung cancer death associated to radon exposure, and (3) to compare the performance of methods for correction of these measurement error effects. The French cohort of uranium miners includes more than 5000 miners chronically exposed to radon with a follow-up duration of 30 years. Measurement errors have been characterized taking into account the evolution of uranium extraction methods and of radiation protection measures over time. A simulation study based on the French cohort of uranium miners has been carried out to investigate the effects of these measurement errors on the estimated ERR and to assess the performance of different methods for correcting these effects. Measurement error associated to radon exposure decreased over time, from more than 45% in the early 70's to about 10% in the late 80's. Its nature also changed over time from mostly Berkson to classical type from 1983. Simulation results showed that measurement error leads to an attenuation of the ERR towards the null

  15. Comparison of the efficiency of the action of ionizing radiation and chemical toxic agents (Cu and phenol) on the pigment system of red algae from the Black Sea

    International Nuclear Information System (INIS)

    The action of various deleterious agents such as gamma-radiation, phenol, and copper on the Black Sea red algae is studied by using the general unit, Grey-ecoequivalent. The comparison of their effective doses that cause the same effect on the algae is made, and the arrangement of the toxic agents is presented according to their toxic properties

  16. Studies of phenolic chelating agents on free radical scavenging activities and inhibitory action in radiation-induced lipid peroxidation

    International Nuclear Information System (INIS)

    Effects of single molecular and double molecular substituted phenolic chelating agents on scavenging of superoxide anions and hydroxyl radicals and inhibition of rat liver mitochondria lipid peroxidation induced by irradiation were studied. The phenolic chelating agents were shown to different extent to scavenge oxygen free radical and the protect against radiation-induced lipid peroxidation, and their half inhibition concentrations (IC50) on hydroxyl radicals generation and lipid peroxidation were 1 x 10-6 mol/L, which of scavenging of superoxide anions were 1 x 10-3 mol/L. 7601(CBMIDA), 9501 and 9502 were the best among them. The free radical scavenging and antioxidant activities were close related to chemical structure and de-corporate bioactivity

  17. Electron impact single ionisation of multiply charged krypton ions

    International Nuclear Information System (INIS)

    Absolute cross sections σsub(q,q+1) for electron impact single ionisation of Krsup(q+) ions (q = 1, 2, 3) have been measured for electron energies up to 700 eV by employing a dynamic crossed-beams technique. The experimental data significantly exceed the Lotz prediction for direct ionisation of Kr2+ and Kr3+ ions, indicating the importance of indirect processes for multiply charged Krsup(q+) ions. The observed ionisation thresholds of cross sections from the present measurements as well as of data from other workers indicate the presence of metastable ions in the parent ion beams. The influence of metastable states on the cross sections is discussed on the basis of Lotz calculations for direct ionisation from different excited states, and differences observed in the experiments are rationalised. (author)

  18. 166Ho-chitosan as a radiation synovectomy agent - antigen-induced arthritis in rabbits

    International Nuclear Information System (INIS)

    Radiation synovectomy is a noninvasive therapy that has been investigated as an alternative to surgical synovectomy. It has been successfully employed in the treatment of synovitis in rheumatoid arthritis and other inflammatory arthropathies. In this study, we developed experimental animal model for radiation synovectomy. A model system in which a single injection of ovalbumin into the knee joints of previously sensitized rabbits consistently produced a chronic arthritis which was histologically similiar to human rheumatoid arthritis. (author). 8 refs., 8 figs

  19. Effects of Heating and Gamma Radiation on the Inhibition of Bacterial Spores by Curing Agents

    International Nuclear Information System (INIS)

    Studies on the resistance of bacterial spores to inhibition by sodium chloride in the recovery medium have shown that both heat and gamma radiation are capable of inflicting damage to the spores which manifests itself as a reduction in salt tolerance. Radiation is at least as effective as heat in causing this damage. Implications of these observations are discussed with respect to cured meat products. (author)

  20. Carcinogenic risks of radiations

    International Nuclear Information System (INIS)

    Ionising radiations are known since the end of the 19th century. Early, after being discovered, they were applied in Medicine and the association with an increased number of different malignant tumors was proved. This paper presents a literature review concerning epidemiological proof of radiation induced cancer, molecular mechanisms and factors that increase or decrease the carcinogenic action of ionizing radiations

  1. Cycloxygenase-2(cox-2) - a potential target for screening of small molecules as radiation countermeasure agents: an in silico study

    International Nuclear Information System (INIS)

    COX-2 is well established for its role in inflammation and cancer, and has also been reported to play a significant role in radiation induced inflammation and by standard effect. It's already reported to have a role in protection against radiation induced damage suggesting it to be an important target for identifying novel radiation countermeasure agents. Present study aims at identifying novel small molecules from pharmacopoeia using COX-2 as target in-silico. Systematic search of the reported molecules exhibiting radiation protection revealed lat around 29 % (40 in 138) of them have a role in inflammation and a small percentage of these molecules (20 %; 8 in 40) are reported to as non steroidal anti-inflammatory drugs (NSAIDS). Docking studies performed further clarified that all these 8 radioprotective molecules shows high binding affinity and inhibit COX-2. Further Johns Hopkins clinical compound library (JHCCL), a collection of small molecule clinical compounds, were screened virtually for COX-2 inhibition by docking approach. Docking of around 1400 small molecules against COX-2 lead to identification of a number of previously unreported molecules which are likely to act as radioprotectors. (author)

  2. Acute syndrome of radiation: injuries to the gastrointestinal tract

    International Nuclear Information System (INIS)

    Acute syndrome of radiation: injuries to the gastrointestinal tract. Exposure to ionising radiation at medium to high doses results in the manifestation of mixed pathologies. Following the analysis of several radiation accidents it is clear that intestinal injury influences patient survival. However the appearance of the classically defined gastrointestinal syndrome is not always evident. Nevertheless injury to the gastrointestinal tract, in particular loss of barrier function, seems to play an important role in the development of Multiple Organ Failure such as reported in the recent accident at Tokai Mura. Ionising radiation overexposure results in changes in intestinal motility and nutrient, fluid and electrolyte absorption and secretion all which may contribute to the genesis of diarrhea. In addition to modified cellular transport properties for nutrients or electrolytes, important loss of epithelial cells is also a major contributing factor. Intestinal functions are controlled by many factors such as neurotransmitters, locally released mediators from endocrine cells or immunocompetent cells in addition to luminal agents. To date, treatment of radiation-induced gastrointestinal injury is mainly symptomatic. However treatments such as growth factors, anti-inflammatory cytokines as well as cellular transplantation remain to be validated in the radiation accident situation. (author)

  3. STTARR: a radiation treatment and multi-modal imaging facility for fast tracking novel agent development in small animal models

    International Nuclear Information System (INIS)

    Small animal models play a pivotal role in the pipeline development of novel agents and strategies in personalized cancer therapy. The Spatio-Temporal Targeting and Amplification of Radiation Response Program (STTARR) consists of an animal imaging and precision radiation facility designed to provide innovative biologic imaging and targeted radiation treatment strategies in small animals. The design is to mirror the imaging and radiation treatment facility in a modern cancer center. The STTARR features imaging equipment of small animal scale including CT, MRI, PET, SPECT, Optical devices as well as image guided irradiators. The fleet of imaging and irradiation equipment provides a platform for identification of biological targets of the specific molecular pathways that influence both tumor progression and a patient's response to radiation therapy. Examples will be given in the utilization of the imaging facilities for development in novel approaches in cancer therapy including a PET-FAZA study for hypoxia measurement in a pancreatic adenocarcinoma xenograft model. In addition, the cone-beam image guided small animal irradiator developed at our institute will also be described. The animal platform (couch) provides motion in 3 dimensions to position the animal to the isocentre of the beam. A pair of rotational arms supporting the X-ray/detector pair enables acquisition of cone-beam images of the animal which give rise to image guided precision of 0.5 mm. The irradiation energy ranges from 50 to 225 kVp at a dose rate from 10-400 cGy/min. The gantry is able to direct X-ray beam of different directions to give conformal radiation treatment to the animal. A dedicated treatment planning system is able to perform treatment planning and provide commonly used clinical metrics in the animal treatment plan. Examples will be given to highlight the use of the image guided irradiator for research of drug/irradiation regimen in animal models. (author)

  4. The effect of intergalactic helium on hydrogen reionisation: implications for the sources of ionising photons at z > 6

    CERN Document Server

    Ciardi, B; Maselli, A; Graziani, L

    2011-01-01

    We investigate the effect of helium on hydrogen reionisation using a hydrodynamical simulation combined with the cosmological radiative transfer code CRASH. The simulations are run in a 35.12/h comoving Mpc box using a variety of assumptions for the amplitude and power-law extreme-UV (EUV) spectral index, alpha, of the ionising emissivity. We use an empirically motivated prescription for ionising sources which ensures all of the models are consistent with constraints on the Thomson scattering optical depth and the hydrogen photo-ionisation rate at z=6. The inclusion of helium slightly delays reionisation due to the small number of ionising photons which reionise neutral helium instead of hydrogen. However, helium has a significant impact on the thermal state of the IGM. Models with alpha=3 produce IGM temperatures at the mean density at z=6 which are about 20 % higher compared to models without helium photo-heating. Harder EUV indices produce even larger IGM temperature boosts. A comparison to recent observat...

  5. The energy and momentum input of supernova explosions in structured and ionised molecular clouds

    CERN Document Server

    Walch, S K

    2014-01-01

    We investigate the early impact of single and binary supernova (SN) explosions on dense gas clouds with three-dimensional, high-resolution, hydrodynamic simulations. The effect of cloud structure, radiative cooling, and ionising radiation from the progenitor stars on the net input of kinetic energy, f_kin=E_kin/E_SN, thermal energy, f_therm=E_therm/E_SN, and gas momentum f_P=P/P_SN to the interstellar medium (ISM) is tested. For clouds with n=100 cm^{-3}, the momentum generating Sedov and pressure-driven snowplough phases are terminated early (~ 0.01 Myr) and radiative cooling limits the coupling to f_therm ~ 0.01, f_kin ~ 0.05, and f_P ~ 9, significantly lower than for the case without cooling. For pre-ionised clouds these numbers are only increased by ~ 50%, independent of the cloud structure. This only suffices to accelerate ~ 5% of the cloud to radial velocities >30km/s. A second SN might further enhance the coupling efficiencies if delayed past the Sedov phase of the first explosion. Such very low coupli...

  6. European Radiation Protection Course - Basics

    International Nuclear Information System (INIS)

    Radiation protection is a major challenge in the industrial applications of ionising radiation, both nuclear and non-nuclear, as well as in other areas such as the medical and research domains. The overall objective of this textbook is to participate to the development of European high-quality scheme and good practices for education and training in radiation protection (RP), coming from the new Council Directive 2013/59/Euratom laying down basic safety standards for protection against the dangers arising from exposure to ionising radiation. These ERPTS (European Radiation Protection Training Scheme) reflects the needs of the Radiation Protection Expert (RPE) and the Radiation Protection Officer (RPO), specifically with respect to the Directive 2013/59/Euratom in all sectors where ionising radiation are applied. To reflect the RPE training scheme, six chapters have been developed in this textbook: Radioactivity and nuclear physics; Interaction of ionising radiation with matter; Dosimetry; Biological effects of ionising radiation; Detection and measurement of ionising radiation; Uses of sources of ionising radiation. The result is a homogeneous textbook, dealing with the ERPTS learning outcomes suggested by ENETRAPII project (European Network on Education and Training in Radiological Protection II) from the 7. Framework Programme. A cyber-book is also part of the whole training material to develop the concept of 'learning more' (http://www.rpe-training.eu). The production of this first module 'basics' training material, in the combined form of a textbook plus a cyber-book as learning tools, will contribute to facilitate mutual recognition and enhanced mobility of these professionals across the European Union. (authors)

  7. Radiation dose estimates for oral agents used in upper gastrointestinal disease

    International Nuclear Information System (INIS)

    Radiation dosimetry was calculated for a number of orally administered radiopharmaceuticals used for study of upper gastrointestinal function. These include: Tc-99m sulfur colloid in water, in a cooked egg, and in chicken liver labeled in vivo; In-111 DTPA; Tc-99m DTPA; In-113m DTPA; Tc-99m ovalbumin in cooked egg; and In-111 colloid in chicken liver labeled in vivo. Radiation burdens to the stomach, small intestine, upper and lower large intestine, ovaries, testes, and total body are calculated for each preparation

  8. Safety Culture in activities involving ionising radiation-education project

    Energy Technology Data Exchange (ETDEWEB)

    Sahyun, A.; Sordi, G. M.; Sanches, M. P.; Levy, P. J.; Levy, D. S.

    2004-07-01

    The Brazilian National Commission of Nuclear Energy (CNEN) requires a Radiological Protection Plan for all installations authorized to work with radioactive material and a qualified Radiological Protection Supervisor. The CNEN requires the certification of practical experience in the area plus a qualification exam, applied by them. ATOMO, has opted to develop on-line courses, using multimedia resources, available at the time this congress takes place. OMICCRON, a multimedia enterprise, is in charge of the program and design. First, the research and brochures have to be adapted for the electronic language, through links, hot words and icons, especially developed for additional information. Besides the images and graphs from the original brochures, Omiccron developed, in graphic computing, specific animation explaining the procedures in more details, illustrating and simplifying the comprehension of the more complex subjects. The CD ROM presentation was enhanced with some slide displays, automatically changing the pictures, as the explanations are given. For practical visualization of these complex and important procedures, the CD also shows some technical videos. At the end of each unit covering a specific subject, the students will be submitted to self-evaluation tests, for more profitable results. This CD is not only an electronic brochure, but mainly an on-line course with weekly Internet support via e-mail or chat site, where the learners will access the instructors and a frequent questions database, useful links and related sites, permanently upgraded. Before going to the following module, the learner has to pass a written test prepared by ATOMO, via Internet. At the end of the course, a certificate will be given. The control will be made through the use of a password, provided for the authorized company and /or users. The instructors will evaluate the learners' advancement by Internet. In the case of companies, this tool will be equally offered, by using a personal manager password. (Author) 10 refs.

  9. Improvements in extremity dose assessment for ionising radiation medical applications

    International Nuclear Information System (INIS)

    This study aims at testing the INTE ring dosemeter based on MCP-Ns and TLD-100 detectors on users from the field of medical applications, namely radio-pharmacists, personnel at a cyclotron facility with corresponding FDG synthesis cells, interventional radiology technologists and radiologists. These users were chosen due to the fact that they have a significantly high risk of exposure to their hands. Following previous results, MCP-Ns TL thin material was used for radiology measurements, whereas TLD-100 was preferred for other applications. The dosemeters were tested to make sure that they were waterproof and that they could be sterilised properly prior to use. Results confirm the need to implement finger dosimetry, mainly for interventional radiologists as finger dose can be >50 times higher than whole-body dose and 3 times higher than wrist dose. (authors)

  10. Safety Culture in activities involving ionising radiation-education project

    International Nuclear Information System (INIS)

    The Brazilian National Commission of Nuclear Energy (CNEN) requires a Radiological Protection Plan for all installations authorized to work with radioactive material and a qualified Radiological Protection Supervisor. The CNEN requires the certification of practical experience in the area plus a qualification exam, applied by them. ATOMO, has opted to develop on-line courses, using multimedia resources, available at the time this congress takes place. OMICCRON, a multimedia enterprise, is in charge of the program and design. First, the research and brochures have to be adapted for the electronic language, through links, hot words and icons, especially developed for additional information. Besides the images and graphs from the original brochures, Omiccron developed, in graphic computing, specific animation explaining the procedures in more details, illustrating and simplifying the comprehension of the more complex subjects. The CD ROM presentation was enhanced with some slide displays, automatically changing the pictures, as the explanations are given. For practical visualization of these complex and important procedures, the CD also shows some technical videos. At the end of each unit covering a specific subject, the students will be submitted to self-evaluation tests, for more profitable results. This CD is not only an electronic brochure, but mainly an on-line course with weekly Internet support via e-mail or chat site, where the learners will access the instructors and a frequent questions database, useful links and related sites, permanently upgraded. Before going to the following module, the learner has to pass a written test prepared by ATOMO, via Internet. At the end of the course, a certificate will be given. The control will be made through the use of a password, provided for the authorized company and /or users. The instructors will evaluate the learners' advancement by Internet. In the case of companies, this tool will be equally offered, by using a personal manager password. (Author) 10 refs

  11. Epidemiological studies and ionizing radiations; Etudes epidemiologiques et rayonnements ionisants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    After some generalities on epidemiological studies, this report presents the current status of knowledge and researches in three peculiar domains: leukaemia for young people living around nuclear power stations, pathologies in workers of the nuclear sector, and health condition (incidence of cancers) of populations living around nuclear power stations

  12. Measurement of ionising radiation semiconductor detectors: a review

    International Nuclear Information System (INIS)

    Manufacturing techniques for nuclear detectors using semiconductors are constantly advancing, and a large range of models with different specificities and characteristics are available. After a theoretical reminder, this report describes the main types of detectors, their working and their preferential use. A comparative table guides the neophyte reader in his choice

  13. Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: study protocol

    OpenAIRE

    Gallastegi, Mara; Guxens, Mònica; Jiménez-Zabala, Ana; Calvente, Irene; Fernández, Marta; Birks, Laura; Struchen, Benjamin; Vrijheid, Martine; Estarlich, Marisa; Fernandez, Mariana; Torrent, Maties; Ballester, Ferran; Aurrekoetxea, Juan José; Ibarluzea, Jesús; Guerra, David

    2016-01-01

    textabstractBackground: Analysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR) and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol describes the methodologies used for characterising exposure of children to EMF-NIR in the INMA (INfancia y Medio Ambiente- Environment and Childhood) Project, a prospective cohort study. Methods/Des...

  14. Radiation compatibilization of polyamide-6/polypropylene blends, enhanced by the presence of compatibilizing agent

    International Nuclear Information System (INIS)

    Radiation compatibilization of polyamide-6 (PA6)/polypropylene (PP) blends was obtained by pre-irradiation of PP by gamma or electron beam irradiation, and enhanced in blends with PP-g-MA (maleic anhydride). Thermal behavior and morphological development were determined by DSC, X-ray and SEM. Compatibilization was confirmed by xylene extraction and Molau test

  15. Synthetic diamond devices for radiotherapy applications: Thermoluminescent dosimeter and ionisation chamber

    International Nuclear Information System (INIS)

    In radiotherapy field, the major usage of dosimeters is in the measurement of the dose received by the patient during radiotherapy (in-vivo measurements) and in beam calibration and uniformity checks. Diamond exhibits several interesting characteristics that make it a good candidate for radiation detection. It is indeed soft-tissue equivalent (Z=6 compared to Z=7.42 for human tissue), mechanically robust and relatively insensitive to radiation damage, chemically stable and non toxic. Moreover, the recent availability of synthetic samples, grown under controlled conditions using the chemical vapour deposition (C.V.D.) technique, allowed decreasing the high cost and the long delivery time of diamond devices. Diamond can be use for off-line dosimetry as thermoluminescent dosimeters or for on-line dosimetry as ionisation chamber [2,3]. These both applications are reported here. For this study, samples were grown in the laboratory and devices were then tested under X-ray irradiations and in clinical environment under medical cobalt source. The work described in this paper was performed in the framework of the European Integrated Project M.A.E.S.T.R.O., Methods and Advanced Equipment for Simulation and Treatment in Radio-Oncology, (6. FP) which is granted by the European Commission.The first results of this study clearly show that C.V.D. diamond detectors are suitable for dosimetry in radiotherapy applications. Moreover, for both T.L. dosimeters and ionisation chambers applications, and even though the sensitivity is subsequently reduced, nitrogen incorporation in films seems to significantly improve the dosimetric characteristics of the devices. Therefore, the optimisation of the material quality appears as a very important issue in order to increase the dosimetric characteristics of devices and more particularly, for use as thermoluminescent dosimeters, other impurities (Nickel, Phosphorus) will be tested. For ionisation chamber applications, experiments with

  16. Optimization of Samarium-153 labeled Hydroxyapatite Particles as Therapeutic Agent for Radiation Synovectomy

    International Nuclear Information System (INIS)

    Hydroxyapatite (HA) was studied as a particular carrier for beta-emitting radionuclides in radiation synovectomy. Particles were labeled with 153Sm (T1/2 = 46.7 hrs., β-energy = 810 (20%), 710(50%), 640(30%) keV, γ-energy = 103.2 (29.8%) KeV, range in tissue = 2.5 mm). Labeling efficiency was greater than 95%, pH 4-6, sterile and pyrogen free, stability is 6 days and in vivo studies by intra-articular injection into knee of normal rats showed the total cumulative leakage of 153Sm over 6 days was around 2% ID, The ease of preparation of 153Sm-HA, efficiency of labeling and low leakage from the joint make 153Sm-HA attractive for radiation synovectomy

  17. Work on optimum medical radiation doses

    International Nuclear Information System (INIS)

    Every day the medical world makes use of X-rays and radioisotopes. Radiology allows organs to be visualised, nuclear medicine diagnoses and treats cancer by injecting radioisotopes, and radiotherapy uses ionising radiation for cancer therapy. The medical world is increasingly mindful of the risks of ionising radiation that patients are exposed to during these examinations and treatments. In 2009 SCK-CEN completed two research projects that should help optimise the radiation doses of patients.

  18. The development of a low-pressure proportional chamber for particle detection in ion-X-ray-coincidence experiments and a study of inner shell differential ionisation probabilities

    International Nuclear Information System (INIS)

    The ionisation chamber is based on design principles of the chambers used in high energy physics. With a low mass coverage of less than 1 mg/cm2 heavy ions (Z>20) with energies higher than 10 MeV can be detected in both spacial directions. Experiments have been performed to measure the K-shell ionisation probability and to study the quasi-molecular L-radiation, in the case of which structures in the differential emission cross-sections have been observed. In addition, by double differential measurements the formation of short-lifed molecular states can be studied. (DG)

  19. Nanoscale photoelectron ionisation detector based on lanthanum hexaboride

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, C.M.; Kunze, U. [Werkstoffe und Nanoelektronik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Schubert, J. [Institute of Bio- and Nanosystems (IBN-1) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Juelich GmbH, 52425 Juelich (Germany); Hamann, S. [Werkstoffe der Mikrotechnik, Ruhr-Universitaet Bochum, 44780 Bochum (Germany); Doll, T. [Institut fuer Physik, Johannes-Gutenberg-Universitaet Mainz, 55128 Mainz (Germany); Adlantis Dortmund, 44263 Dortmund (Germany)

    2011-06-15

    A nanoscale ioniser is presented exceeding the limitation of conventional photoionisation detectors. It employs accelerated photoelectrons that allow obtaining molecule specificity by the tuning of ionisation energies. The material lanthanum hexaboride (LaB{sub 6}) is used as air stable photo cathode. Thin films of that material deposited by pulsed laser deposition (PLD) show quantum efficiency (QE) in the range of 10{sup -5} which is comparable to laser photo stimulation results. A careful treatment of the material yields reasonable low work functions even after surface reoxidation which opens up the possibility of using ultraviolet light emitting diodes (UV LEDs) in replacement of discharge lamps. Schematic diagram of a photoelectron ionisation detector (PeID) operating by an electron emitter based on the photoelectric effect of lanthanum hexaboride. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. The RF System for the International Muon Ionisation Cooling Experiment

    CERN Document Server

    Ronald, K.; Dick, A.J.; Speirs, D.C.; Moss, A.; Grant, A.; White, C.; Griffiths, S.; Stanley, T.; Li, D.; DeMello, A.J.; Virostek, S.; Moretti, A.; Pasquinelli, R.; Peterson, D.; Schultz, R.; Volk, J.; Popovic, M.; Torun, Y.; Hanlet, P.; Alsari, S.; Long, K.; Pasternak, J.; Hunt, C.; Summers, D.; Luo, T.; Smith, P.J.

    2014-01-01

    The International Muon Ionisation Cooling Experiment (MICE) is designed to demonstrate the effectiveness of ionisation cooling to reduce the phase space footprint of a charged particle beam, principally to allow the subsequent acceleration of muons for next generation colliders and/or neutrino factories. The experiment (and indeed any subsequent accelerator cooling channel based on the same principles) poses certain unusual requirements on its RF system, whilst the precision measurement of the ionisation cooling process demands special diagnostics. This paper shall outline the key features of the RF system, including the low level RF control, the power amplifier chain, distribution network, cavities, tuners and couplers, many parts of which are required to operate in a high magnetic field environment. The RF diagnostics which, in conjunction with the other MICE diagnostics, shall allow detailed knowledge of the amplitude and phase of the acceleration field during the transit of each individual muon will also ...

  1. In vitro evaluation of rutin and rutin hydrate as potential radiation countermeasure agents

    International Nuclear Information System (INIS)

    DNA damage is one of the major consequences of radiation exposure onto the biological systems. A series of compounds including flavanoids were found to render DNA protection against radiation damage. In this study we elucidated the potential of rutin and rutin hydrate to protect plasmid DNA against damage induced by irradiation. DPPH and hydroxyl radical scavenging assays were performed to assess the antiradical potential of rutin and rutin hydrate. Absorption measurements were performed to assess binding parameters of rutin and rutin hydrate with CT-DNA. DNA plasmid relaxation assay was performed to compare the radioprotective potential rutin and rutin hydrate against gamma irradiation mediated oxidative damage of pET28 (plasmid DNA). DPPH· assay indicated fast reaction kinetics for rutin and rutin hydrate however antiradical parameter in terms of EC50 suggested better scavenging capacity for rutin hydrate compared to rutin. Hydroxyl radical scavenging assay further suggested that both the compounds displayed significant reduction in hydroxyl radicals. Absorption binding study with CT-DNA suggested that rutin hydrate has better binding constant value (Ka=8.257x104 M-1) compared to Ka= 1.834x104 M-1 for rutin. Plasmid relaxation study demonstrated that plasmid DNA remains predominantly in the super-coiled form in the presence of both rutin and rutin hydrate after exposure to 100 Gy of γ-radiation. The mechanistic studies suggested that binding and scavenging capacity of rutin hydrate and rutin contributes towards DNA radioprotection. This study may be helpful in devising potent radioprotector molecules helpful for the radiotherapy treatment. (author)

  2. Sensitivity of human cells defective of DNA repair enzyme genes to radiation and medical agents

    International Nuclear Information System (INIS)

    Homologous recombination and non-homologous end-joining (NHEJ) are the known mechanisms of repairing DNA with double strand break (DSB) yielded by radiation and cell-cycle independent NHEJ is thought to be major in higher eukaryotes. Recognized now are 7 proteins like Artemis and XRCC4 concerned in NHEJ, but little is known for functions of those proteins in human cells. Authors have developed a method to destroy the specific gene by targeting for the study of the responses to DNA damage in human Artemis-/- and XRCC4-/- cells, which is described in this paper. Parent cell strain is a human colorectal cancer-derived epithelial HCT116, and those defective cells are obtained by targeting with puromycin and neomycin resistant vectors. Their sensitivities to X-ray (0.6 Gy/min), to etoposide and to other anti-cancers are examined by survival vs dose; and the relationship between the sensitivity to damaged DNA stress and DSB production is tested by chromosome aberration frequency and by γH22AX focus formation (a measure of DSB yield) after X-exposure. Results obtained show the important role of Artemis and XRCC4 also in human cell DSB response. With reactive oxygen species (H2O2), those cells are further used in similar experiments to above, which suggesting a different mechanism of DSB induction by H2O2 from that by radiation. Other genes than the two here in NHEJ will be investigated in future with gene targeting techniques for systematic, molecular elucidation of radiation effects in humans. (K.T.)

  3. Biological effects of radiation and chemical agents with special regard to repair processes

    International Nuclear Information System (INIS)

    It is reasonably certain that the introduction or increase of pollutants in the environment can augment mutagenic and carcinogenic effects. These effects are operationally definable, but the genetic organization and the underlying mechanisms of DNA repair, mutagenesis and carcinogenesis are so complex as to make the extrapolation of results from mutagenicity test data to carcinogenicity somewhat uncertain. The subject is reviewed. Recent discoveries in gene organization and expression include overlapping genes in bacteriophages, split genes, processing of RNA and splicing, translocation of genes in eukaryotes, inactivation of the X-chromosome in mammals, etc. Apart from the genetic regulation, plasmids, insertion sequences and mutators can additionally affect mutation frequency. Cancers due to gene mutations, viruses, chemicals and physical agents are known. However, little is known about the epigenetic mechanisms involved. The value of mutagenicity test data is beyond question, but in view of the extraordinary complexities encountered our extrapolations will be more sound if the data have the underpinning of basic information. (author)

  4. The effectiveness of photocatalytic ionisation disinfection of filter materials.

    Science.gov (United States)

    Pietrzak, Katarzyna; Gutarowska, Beata

    2013-01-01

    The purpose of this study was to determine the effectiveness of photocatalytic ionisation as a disinfection method for filter materials contaminated by microorganisms, and to assess how air relative humidity (RH), time and microbe type influence the effectiveness of this disinfection. In the quantitative analysis of a used car air filter, bacterial contamination equalled 1.2 x 10(5) cfu/cm2, fungal contamination was 3.8 x 10(6) cfu/cm2, and the isolated microorganisms were Aspergillus niger, Bacillus megaterium, Cladosporium herbarum, Cryptococcus laurenti, Micrococcus sp., Rhodotorula glutinis and Staphylococcus cohnii. In the model experiment, three isolates (C. herbarum, R. glutinis, S. cohnii) and 3 ATCC species (A. niger, E. coli, S. aureus) were used for photocatalytic ionisation disinfection. The conditions of effective photocatalytic ionisation disinfection (R > or = 99.9%) were established as 2-3 h at RH = 77% (bacteria) and 6-24 h at RH = 53% (fungi). RH has an influence on the effectiveness of the photocatalytic disinfection process; the highest effectiveness was obtained for bacteria at RH = 77%, with results 5% higher than for RH = 49%. The studies show that the sensitivity of microorganisms to photocatalytic ionisation disinfection is ordered as follows: Gram-positive bacteria (S. cohnii, S. aureus), Gram-negative bacteria (E. coli), yeasts (R. glutinis), and moulds (C. herbarum, A. niger). Of all the mathematical models used for the description of death dynamics after photocatalytic ionisation disinfection, the Chick-Watson model is the most useful, but for more resistant microorganisms, the delayed Chick-Watson model is highly recommended. It therefore seems, that the presented disinfection method of photocatalytic ionisation can be successfully used to clean filtration materials. PMID:24053016

  5. SU-E-QI-13: Predictable Models for Radio-Sensitizing Agent Kinetics: Application to Stereotactic Synchrotron Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Obeid, L; Schmitt, M; Esteve, F; Adam, J [Grenoble Institut des Neurosciences, La Tronche, RHONE-ALPES (France)

    2014-06-15

    Purpose: Iodine-enhanced radiotherapy is an innovative treatment combining the selective accumulation of an iodinated contrast agent in brain tumors with irradiations using monochromatic medium energy x-rays. The radiation dose enhancement depends on the time course of iodine in the tumors. A prolonged CT scanning (∼30 min) is required to follow-up iodine kinetics for recruited patients. This protocol could lead to substantial radiation dose to the patient. A novel method is proposed to reduce the acquisition time. Methods: 12 patients received an intravenous bolus of iodinated contrast agent, followed by a steady-state infusion to ensure stable intra-tumoral amounts of iodine during the treatment. Absolute iodine concentrations (IC) were derived from 40 multi-slice dynamic conventional CT images of the brain. The impulse response function (IRF) to the bolus was estimated using the adiabatic approximation of the Johnson and Wilson's model. The arterial input function (AIF) of the steady-state infusion was fitted with several models: Gamma, Gamma with recirculation and hybrid. Estimated IC were calculated by convolving the IRF with the modeled AIF and were compared to the measured data. Results: The gamma variate function was not relevant to model the AIF due to high differences with the measured AIF. The hybrid and the gamma with recirculation models provided differences below 8% during the whole acquisition time. The absolute difference between the measured and the estimated IC was lower than 0.5 mg/ml, which corresponds to 5% of dose enhancement error. Conclusion: The proposed method allows a good estimation of the iodine time course with reduced scanning delays (3 instead of 30 min) and dose to the patient. The results suggest that the dose errors may stay within the radiotherapy standards.

  6. Biological monitors of DNA damage by radiations and other environmental agents. Progress report, May 1974

    International Nuclear Information System (INIS)

    Monolayers of purified spores of repair-defective mutant strains of Bacillus subtilis were used in studies on lethal and mutagenic effects of radiation. Dose-survival and mutation frequency data were obtained with several wave-lengths of uv radiation. Mutation frequencies were higher for spores than for vegetative cells and the use of sporulation and colony morphology markers amplified the detection of mutations. Irradiation by several wavelengths of uv light of B. subtilis bacteriophages and transforming DNA was investigated with repair--defective mutants as hosts. The relative resistance of free DNA to the lethal effects of 300 nm irradiation suggests the formation of unique lesions, such as DNA-protein cross-links in the irradiated phages. Photodynamic inactivation of phages was studied with the result that lesions produced by proflavine and methylene blue were unrepaired in excision repair strains. By contrast, photodynamic inactivation by riboflavin was of the same order of magnitude in excision-repair and wild type strains. A radioimmunoassay was developed for identification of thymine dimers in uv-irradiated B. subtiles DNA. (U.S.)

  7. Long-term genetic and reproductive effects of ionizing radiation and chemotherapeutic agents on cancer patients and their offspring.

    Science.gov (United States)

    Byrne, J

    1999-04-01

    The continuing search for a cure for cancer has lead to more aggressive therapies as new agents are developed with largely unknown late complications. Standard therapy for the majority of cancers today, following surgery, often consists of combinations of high doses of radiation and multi-drug therapy. Compared with exposures experienced by atomic bomb survivors, cancer survivors have been exposed to higher doses of partial body irradiation and combination chemotherapy over longer periods. Thus, cancer survivors provide a model system with which to evaluate the long-term effects on the human organism of high doses of agents known to damage DNA. Five-year survival after cancer diagnosis is now greater than 56%; more than 5 million Americans are considered cured of cancer. However, the late complications of cancer in long-term survivors has been poorly evaluated, especially in adults, and little is known of the most troubling possibility, that is, that the effects of cancer treatments could be passed on to the next generation. What little we know comes from studies of at most 5,000 survivors of childhood cancer, treated decades ago. So far, results are reassuring that with the means now available, we cannot detect clinical evidence of heritable damage. However, reproductive effects, including infertility, are common consequences of cancer therapy and may represent germ cell damage. We are just in the infancy of studies of germ cell mutagenesis in cancer survivors. The relatively small numbers of survivors, and the few types of exposures studied so far, provide only limited grounds for reassurance. More comprehensive, properly designed, studies of modern new agents are urgently need. PMID:10331521

  8. Liquid-xenon γ-camera with ionisation readout

    International Nuclear Information System (INIS)

    The successful operation of a liquid-xenon ionisation chamber with imaging capability is reported. A bi-dimensional readout based on a mini-strip plate--a glass slab with metal strips deposited along two perpendicular directions--was developed and studied both experimentally and by computation. An image of a 122 keV γ-source of 5 mm diameter was obtained with a liquid-xenon ionisation chamber equipped with such readout. A position resolution better than 2 mm was achieved

  9. New Finnish radiation law

    International Nuclear Information System (INIS)

    The new Finnish Radiation Act will enter into force on 1.1.1992. The Act aims to protect man's health against the harmful effects of radiation. The Act applies to the utilization of ionising radiation and natural radiation as well as non-ionising radiation. It emphasises the fact that a licensed organization or entrepreneur carrying out a practice which causes radiation exposure is responsible for the safety of the activity. The organization or entrepreneur in question is also obliged to take care of radioactive waste. The provisions of the Radiation Act which apply to monitoring of worker exposure are also applied to the use of nuclear energy. Activities involving the use of radiation and the use of nuclear energy are regulated by one authority, the Finnish Centre for Radiation and Nuclear Safety. (author)

  10. Health and biological effects of non-ionizing radiations. Meeting of the non-ionizing radiation section of the French radiation protection society (SFRP). Meeting review; Les effets biologiques et sanitaires des rayonnements non ionisants. Journee scientifique de la section RNI de la SFRP - Compte rendu de congres

    Energy Technology Data Exchange (ETDEWEB)

    Perrin, A.; Souques, M. [Electricite de France (EDF), 75 - Paris (France)

    2011-07-15

    This document makes a review of this conference day on biological and health effects of non-ionizing radiations. The program comprised three sessions with a total of 17 presentations dealing with: 1 - NMR: biological effects and implications of Directive 2004/40 on electromagnetic fields (S. Lehericy); 2 - impact of RF frequencies from mobile telephone antennas on body homeostasis (A. Pelletier); 3 - expression of stress markers in the brain and blood of rats exposed in-utero to a Wi-Fi signal (I. Lagroye); 4 - people exposure to electromagnetic waves: the challenge of variability and the contribution of statistics to dosimetry (J. Wiart); 5 - status of knowledge about electromagnetic fields hyper-sensitivity (J.P. Marc-Vergnes); 6 - geno-toxicity of UV radiation: respective impact of UVB and UVA (T. Douki); 7 - National day of prevention and screening for skin cancers (F. Guibal); 8 - UV tan devices: status of knowledge about cancer risks (I. Tordjman, and J. Gaillot de Saintignon); 9 - In vitro study of the extremely low frequencies (ELF) effect on genes expression (J.F. Collard); 10 - modulation of brain activity during a tapping task after exposure to a 3000 {mu}T magnetic field at 60 Hz (M. Souques and A. Legros); 11 - calculation of ELF electromagnetic fields in the human body by the finite elements method (R. Scoretti); 12 - French population exposure to the 50 Hz magnetic field (I. Magne); 13 - LF and static fields, new ICNIRP recommendations: what has changed, what remains (B. Vey. Veyret); 14 - risk assessment of low energy lighting systems - DELs and CFLs (J.P. Cesarini); 15 - biological effects to the rat of a chronic exposure to high power microwaves (R. De Seze); 16 - theoretical and experimental electromagnetic compatibility approaches of active medical implants in the 10-50 Hz frequency range: the case of implantable cardiac defibrillators (J. Katrib); 17 - French physicians and electromagnetic fields (M. Souques). (J.S.)

  11. Cancer in the offspring of radiation workers - a record linkage study

    International Nuclear Information System (INIS)

    The objectives of this study were to test the 'Gardner hypothesis' that childhood leukaemia and non-Hodgkin lymphoma can be caused by paternal exposure to ionising radiation before the conception of the child, and more generally, to investigate whether such radiation exposure of either parent is a cause of childhood cancer. This was a case-control study, conducted in Great Britain, that involved 35,949 children diagnosed as having cancer, together with matched controls. Examination was made of: parental employment as radiation worker as defined by inclusion in the National Registry for Radiation Workers and being monitored for external radiation before conception of child; cumulative dose of external ionising radiation for various periods of employment before conception; pregnancy dose. It is concluded that the results do not support the hypothesis that paternal preconception irradiation is a cause of childhood leukaemia and non-Hodgkin lymphoma; the observed associations may be chance or result from exposure to infective or other agents. If there is any increased risk for the children of fathers who are radiation workers it is small in absolute terms: in Britain the average risk by age 15 years is 6.5 per 10,000; our best estimate, using all available data, is that the increase is 5.4 per 10,000. For mothers, the numbers are too small for reliable estimates of the risk, if any, to be made. (author)

  12. Control of root rot of chickpea caused by Sclerotium rolfsii by different agents and gamma radiation

    International Nuclear Information System (INIS)

    Sclerotium rolfsii causes root rot disease in several crops including chickpea that result in low yield. Artificial infection of chickpea seedlings by S. rolfsii in vitro demonstrated that different tissues of the plant completely disintegrated by fungal infection. In vitro and green house pot experiments demonstrated that inducers in combination with fungicides, oils and bio agents resulted in about 80 % suppression of root rot disease. Treatments have no phyto toxic effect on chickpea seedlings at low doses. Gliocladium virens and Gliocladium deliquescens were effective as biocontrol agents against Sclerotium rolfsii. The percent of survival plants, fresh weight, dry weight and plant height of chickpea plants increased with different treatments with inducers compared with the control. Chlorophyll a, b, and total chlorophyll amounts increased to the maximum values. The activity of two plant enzymes, peroxidase and polyphenol oxidase increased. In this study, gamma irradiation of chickpea seeds at doses 5, 10, 15, 20, 25 and 30 Gy have negative effect on survival, plant height, fresh weight and dry weight of chickpea. The effect of gamma irradiation at doses 0.25, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kGy on the antagonistic effect of Gliocladium virens and Gliocladium deliquescens against S. rolfsii were investigated. The results revealed that gamma irradiation increase the antagonistic effect of Gliocladium virens and Gliocladium deliquescens against S. rolfsii . Effect of gamma irradiation at doses of 0, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 5 kGy on the mycelial growth and pathogenicity of S. rolfsii were investigated. The results revealed that gamma irradiation at doses 0.25 up to 3.0 kGy increase the pathogenicity of S. rolfsii but gamma irradiation at dose 5.0 kGy completely inhibited the growth of S. rolfsii. Extracellular polygalacturonase was characterized and purified by precipitation with 70 % ammonium sulfate, dialysis and gel filtration through Sephadex 75

  13. Radiation-flotation apparatus for waste water purification from surface active agents

    International Nuclear Information System (INIS)

    The flowsheet is described of combined radiation-biological purification of the foam condensate of sewage subjected to flotation by surface-active substances (SAS). Two irradiation schemes at radiolysis are examined, viz. irradiation of foam in an exterior destructor and irradiation in the same volume in which the foam forms. An analysis of the material balance equations in the two schemes shows that at the SAS concentration of 65 mg/l and higher, sewage should be treated by the scheme with destructor, and the irradiated condensate should be introduced into the line of the initial fluid. When the SAS concentration is lower than 65 mg/l, the sewage may be treated by the scheme, in which the destructor and flotation equipment are combined

  14. Imaging Primary Mouse Sarcomas After Radiation Therapy Using Cathepsin-Activatable Fluorescent Imaging Agents

    Energy Technology Data Exchange (ETDEWEB)

    Cuneo, Kyle C. [Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Mito, Jeffrey K.; Javid, Melodi P. [Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States); Ferrer, Jorge M. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Kim, Yongbaek [Department of Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul (Korea, Republic of); Lee, W. David [The David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Bawendi, Moungi G. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Brigman, Brian E. [Department of Orthopedic Surgery, Duke University School of Medicine, Durham, North Carolina (United States); Kirsch, David G., E-mail: david.kirsch@duke.edu [Department of Radiation Oncology, Duke University School of Medicine, Durham, North Carolina (United States); Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, North Carolina (United States)

    2013-05-01

    Purpose: Cathepsin-activated fluorescent probes can detect tumors in mice and in canine patients. We previously showed that these probes can detect microscopic residual sarcoma in the tumor bed of mice during gross total resection. Many patients with soft tissue sarcoma (STS) and other tumors undergo radiation therapy (RT) before surgery. This study assesses the effect of RT on the ability of cathepsin-activated probes to differentiate between normal and cancerous tissue. Methods and Materials: A genetically engineered mouse model of STS was used to generate primary hind limb sarcomas that were treated with hypofractionated RT. Mice were injected intravenously with cathepsin-activated fluorescent probes, and various tissues, including the tumor, were imaged using a hand-held imaging device. Resected tumor and normal muscle samples were harvested to assess cathepsin expression by Western blot. Uptake of activated probe was analyzed by flow cytometry and confocal microscopy. Parallel in vitro studies using mouse sarcoma cells were performed. Results: RT of primary STS in mice and mouse sarcoma cell lines caused no change in probe activation or cathepsin protease expression. Increasing radiation dose resulted in an upward trend in probe activation. Flow cytometry and immunofluorescence showed that a substantial proportion of probe-labeled cells were CD11b-positive tumor-associated immune cells. Conclusions: In this primary murine model of STS, RT did not affect the ability of cathepsin-activated probes to differentiate between tumor and normal muscle. Cathepsin-activated probes labeled tumor cells and tumor-associated macrophages. Our results suggest that it would be feasible to include patients who have received preoperative RT in clinical studies evaluating cathepsin-activated imaging probes.

  15. Regulation of radiation protective agents on cell damage induced by reactive oxygen species

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Hee; Lee, Si Eun; Ju, Eun Mi; Gao, Eu Feng [Kyung Hee University, Seoul (Korea)

    2002-04-01

    In this study, we developed candidates of new radio-protective agents and elucidated the regulation mechanism of these candidates on cell damage induced by reactive oxygen species. The methanol extracts and ethylacetate fractions of NP-1, NP-5, NP-7, NP-11, NP-12 and NP-14 showed higher radical scavenging activity. The extracts of NP-7, NP-12 and NP-14 showed strong protective effect against oxidative damage induced by UV and H{sub 2}O{sub 2}. The most of samples enhanced SOD, CAT and GPX activity in V79-4 cells. The protective effect of samples on H{sub 2}O{sub 2}-induced apoptosis was observed with microscope and flow cytometer. Cells exposed to H{sub 2}O{sub 2} exhibit distinct morphological features of programmed cell death, such as nuclear fragmentation and increase in the percentage of cells with a sub-G1 DNA content. However, cells which was pretreated with samples significantly reduced the characteristics of apoptotic cells. Their morphological observation and DNA profiles were similar to those of the control cells. NP-14 which had excellent antioxidant activity restored G2/M arrest induced by oxidative stress. These data suggested that natural medicinal plants protected H{sub 2}O{sub 2}-induced apoptosis. 42 refs., 29 figs., 11 tabs. (Author)

  16. DNA Repair Genes: Alternative Transcription and Gene Expression at the Exon Level in Response to the DNA Damaging Agent, Ionizing Radiation

    OpenAIRE

    Forrester, Helen B.; Li, Jason; Hovan, Daniel; Ivashkevich, Alesia N.; Sprung, Carl N.

    2012-01-01

    DNA repair is an essential cellular process required to maintain genomic stability. Every cell is subjected to thousands of DNA lesions daily under normal physiological conditions. Ionizing radiation (IR) is a major DNA damaging agent that can be produced by both natural and man-made sources. A common source of radiation exposure is through its use in medical diagnostics or treatments such as for cancer radiotherapy where relatively high doses are received by patients. To understand the detai...

  17. An application of resonant ionisation spectroscopy to accelerator based high energy physics

    International Nuclear Information System (INIS)

    The simulation of charged particle tracks by pulsed UV lasers is now used extensively in the calibration of multiwire drift chambers. The identity of the trace quantities of low ionisation potential impurities responsible for the laser induced ionisation in conventional chamber gases has caused much discussion. Using two photon resonant ionisation spectroscopy two of the major sources of ionisation in proportional counters have been identified as phenol and toluene. (author)

  18. The risk of childhood leukaemia following exposure to ionising radiation—a review

    International Nuclear Information System (INIS)

    Since the early years of follow-up of the Japanese atomic-bomb survivors, it has been apparent that childhood leukaemia has a particular sensitivity to induction by ionising radiation, the excess relative risk (ERR) being expressed as a temporal wave with time since exposure. This pattern has been generally confirmed by studies of children treated with radiotherapy. Case-control studies of childhood leukaemia and antenatal exposure to diagnostic x-rays, a recent large cohort study of leukaemia following CT examinations of young people, and a recent large case-control study of natural background γ-radiation and childhood leukaemia have found evidence of raised risks following low-level exposure. These findings indicate that an ERR/Sv for childhood leukaemia of ∼50, which may be derived from risk models based upon the Japanese atomic-bomb survivors, is broadly applicable to low dose or low dose-rate exposure circumstances. (paper)

  19. Ionizing radiations in Italian health care structures

    International Nuclear Information System (INIS)

    The Council of the European Union has completely renewed the framework regarding radiation protection by adopting some directives: Directive 97/43 EURATOM lays down the general principles of the radiation protection of individuals undergoing exposure to ionising radiations related to medical exposures, as a supplement of Directive 96/29 EURATOM laying down the basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionising radiations.The incorporation into Italian legislation of the European Community directives on the improvement of health and safety at work has promoted a vast effort in order to revise the surveillance approach in many facilities, including hospitals. In Italy, safety law is referred to every workplace; anyway the use of ionising radiations is ruled by specific laws. So in the health care structures it is necessary integrating both the laws and this process is often difficult to carry on. The Italian Legislative Decree 230/95, one the main laws that aim to protect workers against ionising radiations, introduced Directive 96/29/EURATOM. This Decree asks that a doctor and a technical expert analyse the workplace and classify area and workers in according to dose of ionising radiation established by law. The Italian Legislative Decree 626/94 asks that risk analysis in general is made by doctor and specialist in risk. So, in case of risk from ionising radiation, all these figures have to cooperate in order to make an evaluation risk document. (N.C.)

  20. Ionizing radiations in Italian health care structures

    Energy Technology Data Exchange (ETDEWEB)

    Fizzano, M.R.; Frusteri, L. [Technical Advisory Dept. for Risk Assessment and Prevention, Italian Workers Compensation Authority, Rome (Italy)

    2006-07-01

    The Council of the European Union has completely renewed the framework regarding radiation protection by adopting some directives: Directive 97/43 EURATOM lays down the general principles of the radiation protection of individuals undergoing exposure to ionising radiations related to medical exposures, as a supplement of Directive 96/29 EURATOM laying down the basic safety standards for the protection of the health of workers and the general public against the dangers arising from ionising radiations.The incorporation into Italian legislation of the European Community directives on the improvement of health and safety at work has promoted a vast effort in order to revise the surveillance approach in many facilities, including hospitals. In Italy, safety law is referred to every workplace; anyway the use of ionising radiations is ruled by specific laws. So in the health care structures it is necessary integrating both the laws and this process is often difficult to carry on. The Italian Legislative Decree 230/95, one the main laws that aim to protect workers against ionising radiations, introduced Directive 96/29/EURATOM. This Decree asks that a doctor and a technical expert analyse the workplace and classify area and workers in according to dose of ionising radiation established by law. The Italian Legislative Decree 626/94 asks that risk analysis in general is made by doctor and specialist in risk. So, in case of risk from ionising radiation, all these figures have to cooperate in order to make an evaluation risk document. (N.C.)