Low doses of gamma radiation in soybean

Energy Technology Data Exchange (ETDEWEB)

Franco, José G.; Franco, Suely S.H.; Villavicencio, Anna L.C., E-mail: zegilmar60@gmail.com, E-mail: gilmita@uol.com.br, E-mail: villavic@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil); Arthur, Valter; Arthur, Paula B., E-mail: arthur@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franco, Caio H. [Universidade Federal de São Paulo (UNIFESP), SP (Brazil). Departamento de Microbiologia, Imunologia e Parasitologia

2017-07-01

The degree of radiosensitivity depends mostly on the species, the stage of the embryo at irradiation, the doses employed and the criteria used to measure the effect. One of the most common criteria to evaluate radiosensitivity in seeds is to measure the average plant production. Dry soya seeds were exposed to low doses of gamma radiation from source of Cobalt-60, type Gammecell-220, at 0.210 kGy dose rate. In order to study stimulation effects of radiation on germination, plant growth and production. A treatment with four radiation doses was applied as follows: 0 (control); 12.5; 25.0 and 50.0 Gy. Seed germination and harvested of number of seeds and total production were assessed to identify occurrence of stimulation. Soya seeds number and plants were handled as for usual seed production in Brazil. The low doses of gamma radiation in the seeds that stimulate the production were the doses of 12.5 and 50.0 Gy. The results show that the use of low doses of gamma radiation can stimulate germination and plant production. (author)

Effects of proton radiation dose, dose rate and dose fractionation on hematopoietic cells in mice

International Nuclear Information System (INIS)

Ware, J.H.; Rusek, A.; Sanzari, J.; Avery, S.; Sayers, C.; Krigsfeld, G.; Nuth, M.; Wan, X.S.; Kennedy, A.R.

2010-01-01

The present study evaluated the acute effects of radiation dose, dose rate and fractionation as well as the energy of protons in hematopoietic cells of irradiated mice. The mice were irradiated with a single dose of 51.24 MeV protons at a dose of 2 Gy and a dose rate of 0.05-0.07 Gy/min or 1 GeV protons at doses of 0.1, 0.2, 0.5, 1, 1.5 and 2 Gy delivered in a single dose at dose rates of 0.05 or 0.5 Gy/min or in five daily dose fractions at a dose rate of 0.05 Gy/min. Sham-irradiated animals were used as controls. The results demonstrate a dose-dependent loss of white blood cells (WBCs) and lymphocytes by up to 61% and 72%, respectively, in mice irradiated with protons at doses up to 2 Gy. The results also demonstrate that the dose rate, fractionation pattern and energy of the proton radiation did not have significant effects on WBC and lymphocyte counts in the irradiated animals. These results suggest that the acute effects of proton radiation on WBC and lymphocyte counts are determined mainly by the radiation dose, with very little contribution from the dose rate (over the range of dose rates evaluated), fractionation and energy of the protons.

Effects of proton radiation dose, dose rate and dose fractionation on hematopoietic cells in mice.

Science.gov (United States)

Ware, J H; Sanzari, J; Avery, S; Sayers, C; Krigsfeld, G; Nuth, M; Wan, X S; Rusek, A; Kennedy, A R

2010-09-01

The present study evaluated the acute effects of radiation dose, dose rate and fractionation as well as the energy of protons in hematopoietic cells of irradiated mice. The mice were irradiated with a single dose of 51.24 MeV protons at a dose of 2 Gy and a dose rate of 0.05-0.07 Gy/min or 1 GeV protons at doses of 0.1, 0.2, 0.5, 1, 1.5 and 2 Gy delivered in a single dose at dose rates of 0.05 or 0.5 Gy/min or in five daily dose fractions at a dose rate of 0.05 Gy/min. Sham-irradiated animals were used as controls. The results demonstrate a dose-dependent loss of white blood cells (WBCs) and lymphocytes by up to 61% and 72%, respectively, in mice irradiated with protons at doses up to 2 Gy. The results also demonstrate that the dose rate, fractionation pattern and energy of the proton radiation did not have significant effects on WBC and lymphocyte counts in the irradiated animals. These results suggest that the acute effects of proton radiation on WBC and lymphocyte counts are determined mainly by the radiation dose, with very little contribution from the dose rate (over the range of dose rates evaluated), fractionation and energy of the protons.

Estimation of radiation dose received by the radiation workers during radiographic testing

International Nuclear Information System (INIS)

Mohammed, N. A. H. O.

2013-08-01

This study was conducted primarily to evaluate occupational radiation dose in industrial radiography during radiographic testing at Balil-Hadida, with the aim of building up baseline data on radiation exposure in the industrial radiography practice in Sudan. Dose measurements during radiographic testing were performed and compared with IAEA reference dose. In this research the doses measured by using hand held radiation survey meter and personal monitoring dosimeter. The results showed that radiation doses ranged between minimum (0.448 mSv/ 3 month) , and maximum (1.838 mSv / 3 month), with an average value (0.778 mSv/ 3 month), and the standard deviation 0.292 for the workers used gamma mat camera. The analysis of data showed that the radiation dose for all radiation worker are receives less than annual limit for exposed workers 20 mSv/ year and compare with other study found that the dose received while body doses ranging from 0.1 to 9.4 mSv/ year, work area design in all the radiography site followed the three standard rules namely putting radiation signs, reducing access to control area and making of boundaries. Thus the accidents arising from design faults not likely to occur at these site. Results suggest that adequate fundamental training of radiation workers in general radiography prior to industrial radiography work will further improve the standard of personnel radiation protection. (Author)

Biological effects of low-dose ionizing radiation exposure

International Nuclear Information System (INIS)

Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

2009-01-01

The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

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

International Nuclear Information System (INIS)

1998-01-01

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

Radiation hazard control report

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko; Hisanaga, Saemi; Miki, Ryota; Kawai, Hiroshi; Aoki, Yutaka; Sone, Koji; Okada, Hirokazu

1990-01-01

The report describes the radiation hazard control activities performed at the Atomic Energy Research Institute of Kinki University, Japan, during the one-year period from April 1989 to March 1990. Personal radiation hazard control is outlined first focusing on results of physical examination and data of personal exposure dose equivalent. Radiation control in laboratory is then described. Dose equivalent at various places is discussed on the basis of monthly total dose equivalent measured on film badges, measurements made by TLD, and observations made through a continuous radiations monitoring system. The concentration of radiations in air and water is discussed focusing on their measured concentrations in air at the air outlets of tracer/accelerator facilities, and radioactivity in waste water sampled in the reactor facilities and tracer/accelerator facilities. Another discussion is made on the surface contamination density over the floors, draft systems, sink surface, etc. Concerning outdoor radiation hazard control, furthermore, TLD measurements of environmental gamma-rays, data on total gamma-ray radioactivity in environmental samples, and analysis of gamma-ray emitting nuclides in environmental samples are described and discussed. (N.K.)

Measurement of gamma radiation doses in nuclear power plant environment

International Nuclear Information System (INIS)

Bochvar, I.A.; Keirim-Markus, I.B.; Sergeeva, N.A.

1976-01-01

Considered are the problems of measuring gamma radiation dose values and the dose distribution in the nuclear power plant area with the aim of estimating the extent of their effect on the population. Presented are the dosimeters applied, their distribution throughout the controlled area, time of measurement. The distribution of gamma radiation doses over the controlled area and the dose alteration with the increase of the distance from the release source are shown. The results of measurements are investigated. The conclusion is made that operating nuclear power plants do not cause any increase in the gamma radiation dose over the area. Recommendations for clarifying the techniques for using dose-meters and decreasing measurement errors are given [ru

Dose Assurance in Radiation Processing Plants

DEFF Research Database (Denmark)

Miller, Arne; Chadwick, K.H.; Nam, J.W.

1983-01-01

Radiation processing relies to a large extent on dosimetry as control of proper operation. This applies in particular to radiation sterilization of medical products and food treatment, but also during development of any other process. The assurance that proper dosimetry is performed...... at the radiation processing plant can be obtained through the mediation of an international organization, and the IAEA is now implementing a dose assurance service for industrial radiation processing....

Cancer Control Related to Stimulation of Immunity by Low-Dose Radiation

OpenAIRE

Liu, Shu-Zheng

2006-01-01

Previous studies showed that low dose radiation (LDR) could stimulate the immune system in both animal and human populations. This paper reviews the present status of relevant research as support to the use of LDR in clinical practice for cancer prevention and treatment. It has been demonstrated that radiation-induced changes in immune activity follows an inverse J-shaped curve, i.e., low dose stimulation and high dose suppression. The stimulation of immunity by LDR concerns most anticancer p...

System for verifiable CT radiation dose optimization based on image quality. part II. process control system.

Science.gov (United States)

Larson, David B; Malarik, Remo J; Hall, Seth M; Podberesky, Daniel J

2013-10-01

To evaluate the effect of an automated computed tomography (CT) radiation dose optimization and process control system on the consistency of estimated image noise and size-specific dose estimates (SSDEs) of radiation in CT examinations of the chest, abdomen, and pelvis. This quality improvement project was determined not to constitute human subject research. An automated system was developed to analyze each examination immediately after completion, and to report individual axial-image-level and study-level summary data for patient size, image noise, and SSDE. The system acquired data for 4 months beginning October 1, 2011. Protocol changes were made by using parameters recommended by the prediction application, and 3 months of additional data were acquired. Preimplementation and postimplementation mean image noise and SSDE were compared by using unpaired t tests and F tests. Common-cause variation was differentiated from special-cause variation by using a statistical process control individual chart. A total of 817 CT examinations, 490 acquired before and 327 acquired after the initial protocol changes, were included in the study. Mean patient age and water-equivalent diameter were 12.0 years and 23.0 cm, respectively. The difference between actual and target noise increased from -1.4 to 0.3 HU (P process control chart identified several special causes of variation. Implementation of an automated CT radiation dose optimization system led to verifiable simultaneous decrease in image noise variation and SSDE. The automated nature of the system provides the opportunity for consistent CT radiation dose optimization on a broad scale. © RSNA, 2013.

Problems is applying new internal dose coefficients to radiation control

Energy Technology Data Exchange (ETDEWEB)

Sato, Yuichi [Oarai Laboratory, Chiyoda Technol Corporation, Ibaraki (Japan)

1998-06-01

The author discussed problems concerning the conceivable influence in the radiation control and those newly developing when the new internal dose coefficients are applied in the law in the future. For the conceivable influence, the occupational and public exposure was discussed: In the former, the effective dose equivalent limit (at present, 50 mSv/y) was thought to be reduced and in the latter, the limit to be obscure although it might be more greatly influenced by the new coefficients. For newly developing problems, since the new biological model which is more realistic was introduced for calculation of the internal dose and made the calculation more complicated, use of computer is requisite. The effective dose of the internal exposure in the individual monitoring should be conveniently calculated as done at present even after application of the new coefficients. For calculation of the effective dose of the internal exposure, there are such problems as correction of the inhaled particle size and of the individual personal parameter. A model calculation of residual rate in the chest where the respiratory tract alone participated was presented as an example but for the whole body, more complicated functions were pointed out necessary. The concept was concluded to be incorporated in the law in a convenient and easy manner and a software for calculation of internal dose using the new coefficients was wanted. (K.H.)

The ICRP 66 Internal Radiation Exposure Control and Dose Evaluation of The Institute of Nuclear Energy Research

Energy Technology Data Exchange (ETDEWEB)

Pang, H. F.; Hwang, W. S.; Chiu, J. H.

2004-07-01

The Atomic Energy Council (AEC) is the regulatory body of ionization radiation protection in Taiwan. To effectively control the safety in ionization radiation, AEC brought into force the Ionization Radiation Protection Act on 1 February, 2003 with clear statements of the penalty for violating the Law. The Article 5 of the Act provides: In order to limit the radiation exposure from radiation sources or practices, the Competent Authority shall refer to the latest standards of the International Commission on Radiological Protection to lay down the Safety Standards for Protection against Ionizing Radiation. Thus, AEC is going to draft new safety standards of ionization radiation protection of Taiwan according to ICRP Publication 60. The Institute of Nuclear Energy Research (INER), the governmental institute working on ionization radiation research in Taiwan, took the responsibility of assisting AEC in establishing guidelines on the control of internal radiation exposure and responding to the regulations in the new standards as soon as possible. So, according to the recommendations of ICRP Publications 60, 66,67,68,69,71,78,88, and IAEA Safety Standard Series No. RS-G- 1.1 and 1.2, INER undertook researches on the internal radiation exposure control and dose evaluations for INER's radiation workers as well as dose evaluations for the general public. The research accomplishments not only can be the reference of AEC when making new standards, but also can be followed by other radiation protection businesses. (Author) 23 refs.

The ICRP 66 Internal Radiation Exposure Control and Dose Evaluation of The Institute of Nuclear Energy Research

International Nuclear Information System (INIS)

Pang, H. F.; Hwang, W. S.; Chiu, J. H.

2004-01-01

The Atomic Energy Council (AEC) is the regulatory body of ionization radiation protection in Taiwan. To effectively control the safety in ionization radiation, AEC brought into force the Ionization Radiation Protection Act on 1 February, 2003 with clear statements of the penalty for violating the Law. The Article 5 of the Act provides: In order to limit the radiation exposure from radiation sources or practices, the Competent Authority shall refer to the latest standards of the International Commission on Radiological Protection to lay down the Safety Standards for Protection against Ionizing Radiation. Thus, AEC is going to draft new safety standards of ionization radiation protection of Taiwan according to ICRP Publication 60. The Institute of Nuclear Energy Research (INER), the governmental institute working on ionization radiation research in Taiwan, took the responsibility of assisting AEC in establishing guidelines on the control of internal radiation exposure and responding to the regulations in the new standards as soon as possible. So, according to the recommendations of ICRP Publications 60, 66,67,68,69,71,78,88, and IAEA Safety Standard Series No. RS-G- 1.1 and 1.2, INER undertook researches on the internal radiation exposure control and dose evaluations for INER's radiation workers as well as dose evaluations for the general public. The research accomplishments not only can be the reference of AEC when making new standards, but also can be followed by other radiation protection businesses. (Author) 23 refs

Radiation dose exposure in patients affected by lymphoma undergoing repeat CT examinations: how to manage the radiation dose variability.

Science.gov (United States)

Paolicchi, Fabio; Bastiani, Luca; Guido, Davide; Dore, Antonio; Aringhieri, Giacomo; Caramella, Davide

2018-03-01

To assess the variability of radiation dose exposure in patients affected by lymphoma undergoing repeat CT (computed tomography) examinations and to evaluate the influence of different scan parameters on the overall radiation dose. A series of 34 patients (12 men and 22 women with a median age of 34.4 years) with lymphoma, after the initial staging CT underwent repeat follow-up CT examinations. For each patient and each repeat examination, age, sex, use of AEC system (Automated Exposure Control, i.e. current modulation), scan length, kV value, number of acquired scans (i.e. number of phases), abdominal size diameter and dose length product (DLP) were recorded. The radiation dose of just one venous phase was singled out from the DLP of the entire examination. All scan data were retrieved by our PACS (Picture Archiving and Communication System) by means of a dose monitoring software. Among the variables we considered, no significant difference of radiation dose was observed among patients of different ages nor concerning tube voltage. On the contrary the dose delivered to the patients varied depending on sex, scan length and usage of AEC. No significant difference was observed depending on the behaviour of technologists, while radiologists' choices had indirectly an impact on the radiation dose due to the different number of scans requested by each of them. Our results demonstrate that patients affected by lymphoma who undergo repeat whole body CT scanning may receive unnecessary overexposure. We quantified and analyzed the most relevant variables in order to provide a useful tool to manage properly CT dose variability, estimating the amount of additional radiation dose for every single significant variable. Additional scans, incorrect scan length and incorrect usage of AEC system are the most relevant cause of patient radiation exposure.

High-dose preoperative radiation for cancer of the rectum: Impact of radiation dose on patterns of failure and survival

International Nuclear Information System (INIS)

Ahmad, N.R.; Mohiuddin, M.; Marks, G.

1993-01-01

A variety of dose-time schedules are currently used for preoperative radiation therapy of rectal cancer. An analysis of patients treated with high-dose preoperative radiation therapy was undertaken to determine the influence of radiation dose on the patterns of failure, survival, and complications. Two hundred seventy-five patients with localized rectal cancer were treated with high-dose preoperative radiation therapy. One hundred fifty-six patients received 45 Gy (low-dose group). Since 1985, 119 patients with clinically unfavorable cancers were given a higher dose, 55 Gy using a shrinking field technique (high-dose group). All patients underwent curative resection. Median follow-up was 66 months in the low-dose group and 28 months in the high-dose group. Patterns of failure, survival, and complications were analyzed as a function of radiation dose. Fourteen percent of the total group developed a local recurrence; 20% in the low-dose group as compared with 6% in the high-dose group. The actuarial local recurrence rate at 5 years was 20% for the low-dose group and 8% for the high-dose group, and approached statistical significance with p = .057. For tethered/fixed tumors the actuarial local recurrence rates at 5 years were 28% and 9%, respectively, with p = .05. Similarly, for low-lying tumors (less than 6 cm from the anorectal junction) the rates were 24% and 9%, respectively, with p = .04. The actuarial rate of distant metastasis was 28% in the low-dose group and 20% in the high-dose group and was not significantly different. Overall actuarial 5-year survival for the total group of patients was 66%. No significant difference in survival was observed between the two groups, despite the higher proportion of unfavorable cancers in the high-dose group. The incidence of complications was 2%, equally distributed between the two groups. High-dose preoperative radiation therapy for rectal cancer results in excellent local control rates. 27 refs., 2 figs., 8 tabs

A programme to reduce down-time and site radiation dose through improvements in control rod design

International Nuclear Information System (INIS)

Izatt, J.A.; Scobie, J.

1985-01-01

On the UTR-300 reactor at SURRC, it has been found necessary to carry out preventive or remedial maintenance at least once per year on the in-core elements of the control rod assemblies. This has led to reduced availability of the reactor and to significant overall radiation doses to the few long-serving staff members who carry out this work. In an attempt to reduce down-time and radiation dose to staff a radical re-design of the control assemblies was undertaken in-house, and a conversion programme has been underway over the last four years. Details of the design improvements are presented together with a discussion of the operating experience to date. (author)

Registration of radiation doses

International Nuclear Information System (INIS)

2000-02-01

In Finland the Radiation and Nuclear Safety Authority (STUK) is maintaining the register (called Dose Register) of the radiation exposure of occupationally exposed workers in order to ensure compliance with the principles of optimisation and individual protection. The guide contains a description of the Dose Register and specifies the responsibilities of the party running a radiation practice to report the relevant information to the Dose Register

Radiation dose distributions due to sudden ejection of cobalt device

International Nuclear Information System (INIS)

Abdelhady, Amr

2016-01-01

The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building. - Highlights: • This study aims to calculate the dose rate profiles after cobalt device ejection from open-pool-type reactor core. • MicroShield code was used to evaluate the dose rates inside the reactor control room. • McSKY code was used to evaluate the dose rates outside the reactor building. • The calculated dose rates for workers are higher than the permissible limits after 18 s from device ejection.

Assessment of cosmic radiation doses received by air crew

International Nuclear Information System (INIS)

McAulay, I.R.

1998-01-01

Cosmic radiation in the atmosphere is such a complex mixture of radiation type that it is difficult to get a single instrument which is suitable for such measurements. Passive devices such as film badges and track etch detectors have also been used, but again present difficulties of interpretation and requirements of multiple devices to accommodate the different types of radiation encountered. In summary, air crew are the occupational group most highly exposed to radiation. The radiation doses experienced by them are sufficiently high as to require assessment on a regular basis and possible control by appropriate rostering. There appears little possibility of the dose limit for workers being exceeded, except possibly in the case of pregnant female crew. This category of air crew should be the subject of special controls aimed at ensuring that the dose limits for the foetus should not be exceeded

Radiation-hardened control system

International Nuclear Information System (INIS)

Vandermolen, R.I.; Smith, S.F.; Emery, M.S.

1993-01-01

A radiation-hardened bit-slice control system with associated input/output circuits was developed to prove that programmable circuits could be constructed to successfully implement intelligent functions in a highly radioactive environment. The goal for this effort was to design and test a programmable control system that could withstand a minimum total dose of 10 7 rads (gamma). The Radiation Hardened Control System (RHCS) was tested in operation at a dose rate that ranged up to 135 krad/h, with an average total dose of 10.75 Mrads. Further testing beyond the required 10 7 rads was also conducted. RHCS performed properly through the target dose of 10 7 rads, and sporadic intermittent failures in some programmable logic devices were noted after ∼ 13 Mrads

Analysis of occupational doses of radiation workers in medical institutions

International Nuclear Information System (INIS)

Sanaye, S.S.; Baburajan, Sujatha; Joshi, V.D.; Pawar, S.G.; Nalawade, S.K.; Raman, N.V.; Kher, R.K.

2007-01-01

Routine monitoring of occupational radiation workers is done for controlling the doses to the individuals and to demonstrate the compliance with occupational dose limits. One of the objective of personnel monitoring program is the assessment of the radiation safety of working area and trends of exposure histories of individuals or group of workers. Computerised dose registry of all monitored radiation workers along with their personnel data helps in analyzing these trends. This in turn helps the institutions in management of their radiation safety programs. In India, annual and life time occupational dose records are maintained as National Dose Registry in the Radiological Physics and Advisory Division, Bhabha Atomic Research Centre. This paper presents analysis of occupational dose data of monitored radiation workers in medical institutions in India during last five years (i.e. 2002-2006)

Radiation dose of CT coronary angiography in clinical practice: Objective evaluation of strategies for dose optimization

International Nuclear Information System (INIS)

Yerramasu, Ajay; Venuraju, Shreenidhi; Atwal, Satvir; Goodman, Dennis; Lipkin, David; Lahiri, Avijit

2012-01-01

Background: CT coronary angiography (CTCA) is an evolving modality for the diagnosis of coronary artery disease. Radiation burden associated with CTCA has been a major concern in the wider application of this technique. It is important to reduce the radiation dose without compromising the image quality. Objectives: To estimate the radiation dose of CTCA in clinical practice and evaluate the effect of dose-saving algorithms on radiation dose and image quality. Methods: Effective radiation dose was measured from the dose-length product in 616 consecutive patients (mean age 58 ± 12 years; 70% males) who underwent clinically indicated CTCA at our institution over 1 year. Image quality was assessed subjectively using a 4-point scale and objectively by measuring the signal- and contrast-to-noise ratios in the coronary arteries. Multivariate linear regression analysis was used to identify factors independently associated with radiation dose. Results: Mean effective radiation dose of CTCA was 6.6 ± 3.3 mSv. Radiation dose was significantly reduced by dose saving algorithms such as 100 kV imaging (−47%; 95% CI, −44% to −50%), prospective gating (−35%; 95% CI, −29% to −40%) and ECG controlled tube current modulation (−23%; 95% CI, −9% to −34%). None of the dose saving algorithms were associated with a significant reduction in mean image quality or the frequency of diagnostic scans (P = non-significant for all comparisons). Conclusion: Careful application of radiation-dose saving algorithms in appropriately selected patients can reduce the radiation burden of CTCA significantly, without compromising the image quality.

Low-cost teleoperator-controlled vehicle for damage assessment and radiation dose measurement

International Nuclear Information System (INIS)

Tyree, W.H.

1991-01-01

A low-cost, disposable, radio-controlled, remote-reading, ionizing radiation and surveillance teleoperator re-entry vehicle has been built. The vehicle carries equipment, measures radiation levels, and evaluates building conditions. The basic vehicle, radio control with amplifiers, telemetry, elevator, and video camera with monitor cost less than $2500. Velcro-mounted alpha, beta-gamma, and neutron sensing equipment is used in the present system. Many types of health physics radiation measuring equipment may be substituted on the vehicle. The system includes a black-and-white video camera to observe the environment surrounding the vehicle. The camera is mounted on a vertical elevator extendible to 11 feet above the floor. The present vehicle uses a video camera with an umbilical cord between the vehicle and the operators. Preferred operation would eliminate the umbilical. Video monitoring equipment is part of the operator control system. Power for the vehicle equipment is carried on board and supplied by sealed lead-acid batteries. Radios are powered by 9-V alkaline batteries. The radio control receiver, servo drivers, high-power amplifier and 49-MHz FM transceivers were irradiated at moderate rates with neutron and gamma doses to 3000 Rem and 300 Rem, respectively, to ensure system operation

A programme to reduce down-time and site radiation dose through improvements in control rod design

International Nuclear Information System (INIS)

Izatt, J.A.; Scobie, J.

1983-01-01

In many nuclear facilities a high proportion of the total radiation dose to staff may be ascribed to very few routine operations. Often this critical operation will require significant shut-down time, both to perform the function itself and to allow sufficient decay time to reduce radiation levels to acceptable values. This situation arises on the UTR-300 reactor at S.U.R.R.C., where over the twenty years of operation it has been found necessary to carry out preventive, and on some occasions remedial, maintenance at least once per year on the in-core elements of the control rod assemblies. This had led inevitably to reduced availability of the reactor and to significant overall radiation doses to the few long-serving staff members who carry out this work. The source of the problem seems to lie in the basic design of the assemblies, which may have been adequate for the original 10 KW versions of this reactor, but has proven to be deficient in several respects at the present 300 KW operating level. In an attempt to reduce down-time and radiation dose to staff a radical re-design of the control assemblies was undertaken in-house, and a conversion programme has been underway over the last two years. Details of the design improvements are presented with a discussion of the operating experience to date. (author)

Radiation doses to Finns

International Nuclear Information System (INIS)

Rantalainen, L.

1996-01-01

The estimated annual radiation doses to Finns have been reduced in the recent years without any change in the actual radiation environment. This is because the radiation types have been changed. The risk factors will probably be changed again in the future, because recent studies show discrepancies in the neutron dosimetry concerning the city of Hiroshima. Neutron dosimetry discrepancy has been found between the predicted and estimated neutron radiation. The prediction of neutron radiation is calculated by Monte Carlo simulations, which have also been used when designing recommendations for the limits of radiation doses (ICRP60). Estimation of the neutron radiation is made on the basis of measured neutron activation of materials in the city. The estimated neutron dose beyond 1 km is two to ten, or more, times as high as the predicted dose. This discrepancy is important, because the most relevant distances with respect to radiation risk evaluation are between 1 and 2 km. Because of this discrepancy, the present radiation risk factors for gamma and neutron radiation, which rely on the Monte Carlo calculations, are false, too. The recommendations of ICRP60 have been adopted in a few countries, including Finland, and they affect the planned common limits of the EU. It is questionable whether happiness is increased by adopting false limits, even if they are common. (orig.) (2 figs., 1 tab.)

Radiation dose monitoring in the clinical routine

Energy Technology Data Exchange (ETDEWEB)

Guberina, Nika [UK Essen (Germany). Radiology

2017-04-15

Here we describe the first clinical experiences regarding the use of an automated radiation dose management software to monitor the radiation dose of patients during routine examinations. Many software solutions for monitoring radiation dose have emerged in the last decade. The continuous progress in radiological techniques, new scan features, scanner generations and protocols are the primary challenge for radiation dose monitoring software systems. To simulate valid dose calculations, radiation dose monitoring systems have to follow current trends and stay constantly up-to-date. The dose management software is connected to all devices at our institute and conducts automatic data acquisition and radiation dose calculation. The system incorporates 18 virtual phantoms based on the Cristy phantom family, estimating doses in newborns to adults. Dose calculation relies on a Monte Carlo simulation engine. Our first practical experiences demonstrate that the software is capable of dose estimation in the clinical routine. Its implementation and use have some limitations that can be overcome. The software is promising and allows assessment of radiation doses, like organ and effective doses according to ICRP 60 and ICRP 103, patient radiation dose history and cumulative radiation doses. Furthermore, we are able to determine local diagnostic reference doses. The radiation dose monitoring software systems can facilitate networking between hospitals and radiological departments, thus refining radiation doses and implementing reference doses at substantially lower levels.

Radiation doses in interventional neuroradiology

International Nuclear Information System (INIS)

Theodorakou, C.; Butler, P.; Horrocks, J.A.

2001-01-01

Patient radiation doses during interventional radiology (IR) procedures may reach the thresholds for radiation-induced skin and eye lens injuries. This study investigates the radiation doses received by patients undergoing cerebral embolization. Measurements were conducted using thermoluminescent dosimeters. Radiotherapy verification films were used in order to visualise the radiation field. For each procedure the fluoroscopic and digital dose-area product, the fluoroscopic time, the total number of acquired images and entrance-skin dose calculated by the angiographic unit were recorded. In this paper, the skin, eye and thyroid glands doses on a sample of patients are presented. From a preliminary study of 13 patients having undergone cerebral embolization, it was deduced that six of them have received a dose above 1 Gy. Detailed dose data from patients undergoing IR procedures will be collected in the future with the aim of developing a model to allow estimation of the dose prior to the procedure as well as to look at techniques of dose reduction. (author)

Labour cost of radiation dose

International Nuclear Information System (INIS)

Cook, A.; Lockett, L.E.

1978-01-01

In order to optimise capital expenditure on measures to protect workers against radiation it would be useful to have a means to measure radiation dose in money terms. Because labour has to be employed to perform radiation work there must be some relationship between the wages paid and the doses received. Where the next increment of radiation dose requires additional labour to be recruited the cost will at least equal the cost of the extra labour employed. This paper examines some of the factors which affect the variability of the labour cost of radiation dose and notes that for 'in-plant' exposures the current cost per rem appears to be significantly higher than values quoted in ICRP Publication 22. An example is given showing how this concept may be used to determine the capital it is worth spending on installed plant to prevent regular increments of radiation dose to workers. (author)

Radiation dose in dental radiology

International Nuclear Information System (INIS)

Cohnen, M.; Kemper, J.; Moedder, U.; Moebes, O.; Pawelzik, J.

2002-01-01

The aim of this study was to compare radiation exposure in panoramic radiography (PR), dental CT, and digital volume tomography (DVT). An anthropomorphic Alderson-Rando phantom and two anatomical head phantoms with thermoluminescent dosimeters fixed at appropriate locations were exposed as in a dental examination. In PR and DVT, standard parameters were used while variables in CT included mA, pitch, and rotation time. Image noise was assessed in dental CT and DVT. Radiation doses to the skin and internal organs within the primary beam and resulting from scatter radiation were measured and expressed as maximum doses in mGy. For PR, DVT, and CT, these maximum doses were 0.65, 4.2, and 23 mGy. In dose-reduced CT protocols, radiation doses ranged from 10.9 to 6.1 mGy. Effective doses calculated on this basis showed values below 0.1 mSv for PR, DVT, and dose-reduced CT. Image noise was similar in DVT and low-dose CT. As radiation exposure and image noise of DVT is similar to low-dose CT, this imaging technique cannot be recommended as a general alternative to replace PR in dental radiology. (orig.)

The health effects of low-dose ionizing radiation

International Nuclear Information System (INIS)

Dixit, A.N.; Dixit, Nishant

2012-01-01

It has been established by various researches, that high doses of ionizing radiation are harmful to health. There is substantial controversy regarding the effects of low doses of ionizing radiation despite the large amount of work carried out (both laboratory and epidemiological). Exposure to high levels of radiation can cause radiation injury, and these injuries can be relatively severe with sufficiently high radiation doses. Prolonged exposure to low levels of radiation may lead to cancer, although the nature of our response to very low radiation levels is not well known at this time. Many of our radiation safety regulations and procedures are designed to protect the health of those exposed to radiation occupationally or as members of the public. According to the linear no-threshold (LNT) hypothesis, any amount, however small, of radiation is potentially harmful, even down to zero levels. The threshold hypothesis, on the other hand, emphasizes that below a certain threshold level of radiation exposure, any deleterious effects are absent. At the same time, there are strong arguments, both experimental and epidemiological, which support the radiation hormesis (beneficial effects of low-level ionizing radiation). These effects cannot be anticipated by extrapolating from harmful effects noted at high doses. Evidence indicates an inverse relationship between chronic low-dose radiation levels and cancer incidence and/or mortality rates. Examples are drawn from: 1) state surveys for more than 200 million people in the United States; 2) state cancer hospitals for 200 million people in India; 3) 10,000 residents of Taipei who lived in cobalt-60 contaminated homes; 4) high-radiation areas of Ramsar, Iran; 5) 12 million person-years of exposed and carefully selected control nuclear workers; 6) almost 300,000 radon measurements of homes in the United States; and 7) non-smokers in high-radon areas of early Saxony, Germany. This evidence conforms to the hypothesis that

The Spanish National Dose Registry and Spanish radiation passbooks

International Nuclear Information System (INIS)

Hernandez, A.; Martin, A.; Villanueva, I.; Amor, I.; Butragueno, J.L.

2001-01-01

The Spanish National Dose Registry (BDN) is the Nuclear Safety Council's (CSN) national database of occupational exposure to radiation. Each month BDN receives records of individual external doses from approved dosimetry services. The dose records include information regarding the occupational activities of exposed workers. The dose information and the statistical analysis prepared by the BDN are a useful tool for effective operational protection of occupationally exposed workers and a support for the CSN in the development and application of the ALARA principle. The Spanish radiation passbook was introduced in 1990 and since then CSN, as regulatory authority, has required that all outside workers entering controlled areas should have radiation passbooks. Nowadays, CSN has implemented improvements in the Spanish radiation Passbooks, taking into account previous experience and Directive 96/29/EURATOM. (author)

Radiation dose distributions due to sudden ejection of cobalt device.

Science.gov (United States)

Abdelhady, Amr

2016-09-01

The evaluation of the radiation dose during accident in a nuclear reactor is of great concern from the viewpoint of safety. One of important accident must be analyzed and may be occurred in open pool type reactor is the rejection of cobalt device. The study is evaluating the dose rate levels resulting from upset withdrawal of co device especially the radiation dose received by the operator in the control room. Study of indirect radiation exposure to the environment due to skyshine effect is also taken into consideration in order to evaluate the radiation dose levels around the reactor during the ejection trip. Microshield, SHLDUTIL, and MCSky codes were used in this study to calculate the radiation dose profiles during cobalt device ejection trip inside and outside the reactor building. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ionizing radiation dose control for workers in a nuclear plant working with unsealed sources

International Nuclear Information System (INIS)

Gerulis, Eduardo

2006-01-01

With the liberation of the use of the nuclear energy for peaceful applications, International Commission Radiological Protection, ICRP, founded in 1928, created a system of protection of the undesirable doses of ionizing radiation in 1958. This has been received by workers, members of the public and environment and hence it became possible for the introduction of these applications. This protection system is adopted by the International Agency of Energy Atomic, IAEA, that publishes recommendations in safety series, 88 and by the Comissao Nacional de Energia Nuclear, CNEN, which publishes these regulations. The international recommendations and national regulations were adapted and they need to be applied in this way. The present paper uses recommendations of the publication 75 from ICRP, of the publication 115 from 88 and regulations of the regulation NN 3.01 from CNEN to present, through radiological protection measures, the ionizing radiation dose control for workers in a nuclear plant that works in the research, production, division and packing of unsealed sources to be used in clinical applications. In that way it is possible to prevent appropriately the undesirable doses and to confirm the received doses. (author)

Dose reconstruction modeling for medical radiation workers

International Nuclear Information System (INIS)

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

2017-01-01

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

Dose reconstruction modeling for medical radiation workers

Energy Technology Data Exchange (ETDEWEB)

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

2017-04-15

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

Development of radiation dose assessment system for radiation accident (RADARAC)

International Nuclear Information System (INIS)

Takahashi, Fumiaki; Shigemori, Yuji; Seki, Akiyuki

2009-07-01

The possibility of radiation accident is very rare, but cannot be regarded as zero. Medical treatments are quite essential for a heavily exposed person in an occurrence of a radiation accident. Radiation dose distribution in a human body is useful information to carry out effectively the medical treatments. A radiation transport calculation utilizing the Monte Carlo method has an advantageous in the analysis of radiation dose inside of the body, which cannot be measured. An input file, which describes models for the accident condition and quantities of interest, should be prepared to execute the radiation transport calculation. Since the accident situation, however, cannot be prospected, many complicated procedures are needed to make effectively the input file soon after the occurrence of the accident. In addition, the calculated doses are to be given in output files, which usually include much information concerning the radiation transport calculation. Thus, Radiation Dose Assessment system for Radiation Accident (RADARAC) was developed to derive effectively radiation dose by using the MCNPX or MCNP code. RADARAC mainly consists of two parts. One part is RADARAC - INPUT, which involves three programs. A user can interactively set up necessary resources to make input files for the codes, with graphical user interfaces in a personnel computer. The input file includes information concerning the geometric structure of the radiation source and the exposed person, emission of radiations during the accident, physical quantities of interest and so on. The other part is RADARAC - DOSE, which has one program. The results of radiation doses can be effectively indicated with numerical tables, graphs and color figures visibly depicting dose distribution by using this program. These results are obtained from the outputs of the radiation transport calculations. It is confirmed that the system can effectively make input files with a few thousand lines and indicate more than 20

Study of national registration systems for health records of radiation workers. National radiation dose registration system

International Nuclear Information System (INIS)

Nakagawa, Haruo; Kanda, Keiji

1999-01-01

A national radiation dose registration system is proposed in this paper. In Japan, only one radiation dose registration system is partly effective. It is applied for workers in nuclear power plants which are under control of regulatory laws for nuclear reactors. The total system was proposed previously by the Committee for Compensation Claims of Nuclear Accidents. The reason for the delay in establishing a registration system for all radiation workers is supposedly a lack of effort to adjust differences among items in radiation protection laws and the promotion of public acceptance to atomic power. Items about dose recordings, record keeping and dose-record reporting in all of the radiation regulatory laws are compared to each other, and items were extracted for revision. (author)

Management of pediatric radiation dose using Philips fluoroscopy systems DoseWise: perfect image, perfect sense

International Nuclear Information System (INIS)

Stueve, Dick

2006-01-01

Although image quality (IQ) is the ultimate goal for accurate diagnosis and treatment, minimizing radiation dose is equally important. This is especially true when pediatric patients are examined, because their sensitivity to radiation-induced cancer is two to three times greater than that of adults. DoseWise is an ALARA-based philosophy within Philips Medical Systems that is active at every level of product design. It encompasses a set of techniques, programs and practices that ensures optimal IQ while protecting people in the X-ray environments. DoseWise methods include management of the X-ray beam, less radiation-on time and more dose information for the operator. Smart beam management provides automatic customization of the X-ray beam spectrum, shape, and pulse frequency. The Philips-patented grid-controlled fluoroscopy (GCF) provides grid switching of the X-ray beam in the X-ray tube instead of the traditional generator switching method. In the examination of pediatric patients, DoseWise technology has been scientifically documented to reduce radiation dose to <10% of the dose of traditional continuous fluoroscopy systems. The result is improved IQ at a significantly lower effective dose, which contributes to the safety of patients and staff. (orig.)

Carcinogenesis induced by low-dose radiation

Directory of Open Access Journals (Sweden)

Piotrowski Igor

2017-11-01

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

Biological influence from low dose and low-dose rate radiation

International Nuclear Information System (INIS)

Magae, Junji

2007-01-01

Although living organisms have defense mechanisms for radioadaptive response, the influence is considered to vary qualitatively and quantitatively for low dose and high dose, as well as for low-dose rate and high-dose rate. This article describes the bioresponse to low dose and low-dose rate. Among various biomolecules, DNA is the most sensitive to radiation, and accurate replication of DNA is an essential requirement for the survival of living organisms. Also, the influence of active enzymes resulted from the effect of radiation on enzymes in the body is larger than the direct influence of radiation on the body. After this, the article describes the carcinogenic risk by low-dose radiation, and then so-called Hormesis effect to create cancer inhibition effect by stimulating active physiology. (S.K.)

New technologies to reduce pediatric radiation doses

International Nuclear Information System (INIS)

Bernhardt, Philipp; Lendl, Markus; Deinzer, Frank

2006-01-01

X-ray dose reduction in pediatrics is particularly important because babies and children are very sensitive to radiation exposure. We present new developments to further decrease pediatric patient dose. With the help of an advanced exposure control, a constant image quality can be maintained for all patient sizes, leading to dose savings for babies and children of up to 30%. Because objects of interest are quite small and the speed of motion is high in pediatric patients, short pulse widths down to 4 ms are important to reduce motion blurring artifacts. Further, a new noise-reduction algorithm is presented that detects and processes signal and noise in different frequency bands, generating smooth images without contrast loss. Finally, we introduce a super-resolution technique: two or more medical images, which are shifted against each other in a subpixel region, are combined to resolve structures smaller than the size of a single pixel. Advanced exposure control, short exposure times, noise reduction and super-resolution provide improved image quality, which can also be invested to save radiation exposure. All in all, the tools presented here offer a large potential to minimize the deterministic and stochastic risks of radiation exposure. (orig.)

TLD DRD dose discrepancy: role of beta radiation fields

International Nuclear Information System (INIS)

Munish Kumar; Pradhan, S.M.; Bihari, R.R.; Bakshi, A.K.; Chougaonkar, M.P.; Babu, D.A.R.; Gupta, Anil

2014-01-01

Ionization chamber based direct reading/pocket dosimeters (DRDs), are used along with the legal dosimeters (thermoluminescent dosimeters-TLDs) for day to day monitoring and control of radiation doses received by radiation workers. The DRDs are routinely used along with the passive dosimeters (TLDs) in nuclear industry at different radiation installations where radiation levels could vary significantly and the possibility of receiving doses beyond investigation levels by radiation workers is not ruled out. Recently, recommendations for dealing with discrepancies between personal dosimeter systems used in parallel were issued by ISO. The present study was performed to measure the response of ionization chamber based pocket dosimeters to various beta sources having energy (E max ) ranging from 0.224 MeV-3.54 MeV. It is expected that the above study will be useful in resolving the disparity between TLD and DRD doses at those radiation installations where radiation workers are likely to be exposed simultaneously from photons and beta particles

[Dose rate-dependent cellular and molecular effects of ionizing radiation].

Science.gov (United States)

Przybyszewski, Waldemar M; Wideł, Maria; Szurko, Agnieszka; Maniakowski, Zbigniew

2008-09-11

The aim of radiation therapy is to kill tumor cells while minimizing damage to normal cells. The ultimate effect of radiation can be apoptotic or necrotic cell death as well as cytogenetic damage resulting in genetic instability and/or cell death. The destructive effects of radiation arise from direct and indirect ionization events leading to peroxidation of macromolecules, especially those present in lipid-rich membrane structures as well as chromatin lipids. Lipid peroxidative end-products may damage DNA and proteins. A characteristic feature of radiation-induced peroxidation is an inverse dose-rate effect (IDRE), defined as an increase in the degree of oxidation(at constant absorbed dose) accompanying a lower dose rate. On the other hand, a low dose rate can lead to the accumulation of cells in G2, the radiosensitive phase of the cell cycle since cell cycle control points are not sensitive to low dose rates. Radiation dose rate may potentially be the main factor improving radiotherapy efficacy as well as affecting the intensity of normal tissue and whole-body side effects. A better understanding of dose rate-dependent biological effects may lead to improved therapeutic intervention and limit normal tissue reaction. The study reviews basic biological effects that depend on the dose rate of ionizing radiation.

Regulatory control of low level radiation exposure in Tanzania

International Nuclear Information System (INIS)

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

1997-01-01

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

Health effects of low-dose radiation: Molecular, cellular, and biosystem response

International Nuclear Information System (INIS)

Pollycove, M.; Paperiello, C.J.

1997-01-01

Since the fifties, the prime concern of radiation protection has been protecting DNA from damage. UNSCEAR initiated a focus on biosystem response to damage with its 1994 report, ''Adaptive Responses to Radiation of Cells and Organisms''. The DNA damage-control biosystem is physiologically operative on both metabolic and radiation induced damage, both effected predominantly by free radicals. These adaptive responses are suppressed by high-dose and stimulated by low dose radiation. Increased biosystem efficiently reduces the number of mutations that accumulate during a lifetime and decrease DNA damage-control with resultant aging and malignancy. Several statistically significant epidemiologic studies have shown risk decrements of cancer mortality and mortality from all causes in populations exposed to low-dose radiation. Further biologic and epidemiologic research is needed to establish a valid threshold below which risk decrements occur. (author)

Biological effects of low-dose radiation on human population living in high-background radiation areas of Kerala coast

International Nuclear Information System (INIS)

Das, Birajalaxmi

2016-01-01

High-level natural radiation areas (HLNRA) of Kerala coast is densely populated and known for its wide variation in background radiation dose levels due to uneven distribution of monazite in the beach sand. The background radiation dose varies from 1 to 45 mGv/y. The areas with >1.5mGy/y is considered as HLNRA. Human population inhabiting in this area are exposed to low-dose chronic radiation since generations. Hence, this population provides an ideal situation to study dose response and adaptive response, if any, due to natural chronic low-dose exposure. It has been investigated extensively to study the biological and health effects of long-term low-dose/low-dose radiation exposure. So far over 150, 000 newborns monitored from hospital-based study did not reveal any significant difference in the incidence of any of the malformations and stillbirth between HLNRA and adjacent control areas. A case-control study on cleft lip/palate and mental retardation did not show any association with background radiation dose. Cytogenetic investigation of over 27,000 newborns did not show any significant increase in the frequency of chromosome aberrations and karyotype anomalies. DNA damage endpoints, such as micronuclei, telomere length and DNA strand breaks, did not reveal any significant difference between control and exposed population. Studies on DNA damage and repair revealed efficient repair of DNA strand breaks in HLNRA individuals. Molecular studies using high throughput microarray analysis indicated a large number of genes involved in various molecular and cellular pathways. Indications of in vivo radioadaptive response due to natural chronic low-dose exposure in this population have important implications to human health. (author)

Dose budget for exposure control

International Nuclear Information System (INIS)

Nair, P.S.

1999-01-01

Dose budget is an important management tool to effectively control the collective dose incurred in a nuclear facility. The budget represents a set of yardsticks or guidelines for use in controlling the internal activities, involving radiation exposure in the organisation. The management, through budget can evaluate the radiation protection performance at every level of the organisation where a number of independent functional groups work on routine and non-routine jobs. The discrepancy between the plan and the actual performance is high lighted through the budgets. The organisation may have to change the course of its operation in a particular area or revise its plan with due focus on appropriate protective measures. (author)

Analysis of Biochemical Control and Prognostic Factors in Patients Treated With Either Low-Dose Three-Dimensional Conformal Radiation Therapy or High-Dose Intensity-Modulated Radiotherapy for Localized Prostate Cancer

International Nuclear Information System (INIS)

Vora, Sujay A.; Wong, William W.; Schild, Steven E.; Ezzell, Gary A.; Halyard, Michele Y.

2007-01-01

Purpose: To identify prognostic factors and evaluate biochemical control rates for patients with localized prostate cancer treated with either high-dose intensity-modulated radiotherapy (IMRT) or conventional-dose three-dimensional conformal radiotherapy 3D-CRT. Methods: Four hundred sixteen patients with a minimum follow-up of 3 years (median, 5 years) were included. Two hundred seventy-one patients received 3D-CRT with a median dose of 68.4 Gy (range, 66-71 Gy). The next 145 patients received IMRT with a median dose of 75.6 Gy (range, 70.2-77.4 Gy). Biochemical control rates were calculated according to both American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definitions. Prognostic factors were identified using both univariate and multivariate analyses. Results: The 5-year biochemical control rate was 60.4% for 3D-CRT and 74.1% for IMRT (p < 0.0001, first ASTRO Consensus definition). Using the ASTRO Phoenix definition, the 5-year biochemical control rate was 74.4% and 84.6% with 3D-RT and IMRT, respectively (p = 0.0326). Univariate analyses determined that PSA level, T stage, Gleason score, perineural invasion, and radiation dose were predictive of biochemical control. On multivariate analysis, dose, Gleason score, and perineural invasion remained significant. Conclusion: On the basis of both ASTRO definitions, dose, Gleason score, and perineural invasion were predictive of biochemical control. Intensity-modulated radiotherapy allowed delivery of higher doses of radiation with very low toxicity, resulting in improved biochemical control

Radiation control report

International Nuclear Information System (INIS)

Inagaki, Masayo; Matsuda, Toshiro; Wakabayashi, Genichiro; Yamamoto, Tomosada; Takiguchi, Chizuko; Yamanishi, Hirokuni

2015-01-01

This paper reports the results of radiation control during April 2013 and April 2014 at the Atomic Energy Research Institute of Kinki University. The subjects of radiation control were totally 148 persons including teaching staff and students who engaged in radiation jobs at the Atomic Energy Research Institute, the Faculty of Science and Engineering, and the Faculty of Pharmacy. As for the operating conditions of the reactor, total operating time was 485.28 hours. Since new regulations came into force in accordance with the law revision in December 2013, this reactor became unable to operate since the regular inspection in February 2014, and the verification of compliance to the new regulatory standards has become necessary for the restart. In this paper, the following are described as the radiation management that was carried out on a regular basis in FY2013: (1) health diagnosis and individual exposure dose management, as personal management, (2) dose rate measurements in facilities and measurements of radioactive substance concentration in the air and water, as facility management, and (3) measurement data and analysis results of environmental γ-ray dose rate, total β radioactivity concentration in environmental samples, and γ-ray nuclide analysis of environmental samples, as field management. (A.O.)

Time Demand and Radiation Dose in 3D-Fluoroscopy-based Navigation-assisted 3D-Fluoroscopy-controlled Pedicle Screw Instrumentations.

Science.gov (United States)

Balling, Horst

2018-05-01

Prospective single-center cohort study to record additional time requirements and radiation dose in navigation-assisted O-arm-controlled pedicle screw (PS) instrumentations. The aim of this study was to evaluate amount of extra-time and radiation dose for navigation-assisted PS instrumentations of the thoracolumbosacral spine using O-arm 3D-real-time-navigation (O3DN) compared to non-navigated spinal procedures (NNSPs) with a single C-arm and postoperative computed tomography (CT) scan for controlling PS positions. 3D-navigation is reported to enhance PS insertion accuracy. But time-consuming navigational steps and considerable additional radiation doses seem to limit this modern technique's attraction. A detailed analysis of additional time demand and extra-radiation dose in 3D-navigated spine surgery is not provided in literature, yet. From February 2011 through July 2015, 306 consecutive posterior instrumentations were performed in vertebral levels T10-S1 using O3DN for PS insertion. The duration of procedure-specific navigational steps of the overall collective (I) and the last cohort of 50 consecutive O3DN-surgeries (II) was compared to the average duration of analogous surgical steps in 100 consecutive NNSP using a single C-arm. 3D-radiation dose (dose-length-product, DLP) of navigational and postinstrumentation O-arm scans in group I and II was compared to the average DLP of 100 diagnostic lumbar CT scans. The average presurgical time from patient positioning on the operating table to skin incision was 46.2 ± 10.1 minutes (O3DN, I) and 40.6 ± 9.8 minutes (O3DN, II) versus 30.6 ± 8.3 minutes (NNSP) (P demand of 13.0 minutes compared to NNSP, and with a total DLP below that of a diagnostic lumbar CT scan (P ≈ 0.81). 4.

Oligodendroglial response to ionizing radiation: Dose and dose-rate response

International Nuclear Information System (INIS)

Levy, R.P.

1991-01-01

An in vitro system using neuroglia from neonatal rat brain was developed to examining the morphologic, immunocytochemical and biochemical response of oligodendroglia to ionizing radiation. Following acute γ-radiation at day-in-culture (DIC) 8, oligodendrocyte counts at DIC 14 were 55% to 65% of control values after 2 Gy, and 29% to 36% after 5 Gy. Counts increased to near-normal levels at DIC 21 in the 2 Gy group and to 75% of normal in the 5 Gy group. Myelin basic protein levels (MBP) at DIC 14 were 60% of control values after 2 Gy, and 40% after 5 Gy. At DIC 21, MBP after 2 Gy was 45% greater than that observed at DIC 14, but MBP, as a fraction of age-matched control values, dropped from 60% to 50%. Following 5 Gy, absolute MBP changed little between DIC 14 and DIC 21, but decreased from 40% to 25% of control cultures. It was concluded that oligodendrocytes in irradiated cultures had significantly lower functional capacity than did unirradiated controls. The response to split-dose irradiation indicated that nearly all sublethal damage in the oligodendrocyte population (and its precursors) was repaired within 3 h to 4 h. At DIC 14, the group irradiated in a single fraction had significantly lower oligodendrocyte counts than any group given split doses; all irradiated cultures had marked depression of MBP synthesis, but to significant differences referable to time interval between doses. At DIC 21, cultures irradiated at intervals of 0 h to 2 h had similar oligodendrocyte counts to one another, but these counts were significantly lower than in cultures irradiated at intervals of 4 h to 6 h; MBP levels remained depressed at DIC 21 for all irradiated cultures. The oligodendrocyte response to dose rate (0.03 to 1.97 Gy/min) was evaluated at DIC 14 and DIC 21. Exposure at 0.03 Gy/min suppressed oligodendrocyte counts at DIC 21 less than did higher dose rates in 5-Gy irradiated cultures

Cancer and low dose responses in vivo: implications for radiation protection

International Nuclear Information System (INIS)

Mitchel, R.E.J.

2006-01-01

Full text: Radiation protection practices assume that cancer risk is linearly proportional to total dose, without a threshold, both for people with normal cancer risk and for people who may be genetically cancer prone. Mice heterozygous for the Tp 53 gene are cancer prone, and their increased risk from high doses was not different from Tp 53 normal mice. However, in either Tp 53 normal or heterozygous mice, a single low dose of low LET radiation given at low dose rate protected against both spontaneous and radiation-induced cancer by increasing tumor latency. Increased tumor latency without a cancer frequency change implies that low doses in vivo primarily slow the process of genomic instability, consistent with the elevated capacity for correct DSB rejoining seen in low dose exposed cells. The in vivo animal data indicates that, for low doses and low dose rates in both normal and cancer prone adult mice, risk does not increase linearly with dose, and dose thresholds for increased risk exist. Below those dose thresholds (which are influenced by Tp 53 function) overall risk is reduced below that of unexposed control mice, indicating that Dose Rate Effectiveness Factors (DREF) may approach infinity, rather than the current assumption of 2. However, as dose decreases, different tissues appear to have different thresholds at which detriment turns to protection, indicating that individual tissue weighting factors (Wt) are also not constant, but vary from positive values to zero with decreasing dose. Measurements of Relative Biological Effect between high and low LET radiations are used to establish radiation weighting factors (Wr) used in radiation protection, and these are also assumed to be constant with dose. However, since the risk from an exposure to low LET radiation is not constant with dose, it would seem unlikely that radiation-weighting factors for high LET radiation are actually constant at low dose and dose rate

Radiation control system

International Nuclear Information System (INIS)

Murao, Mitsuo.

1985-01-01

Purpose: To rapidly and suitably performing planning and designation by radiation-working control systems in the radiation controlled area of nuclear power plant. Method: Various informations regarding radiation exposure are arranged and actual exposure data are statistically stored, to thereby perform forecasting calculation for the radiation exposure upon workings in the plurality of working regions in the radiation controlled area. Based on the forecast values and the registered workers' exposure dose in the past workings are alocated successively such that the total exposure does upon conducting the workings is less than the limited value, to prepare working plans in the areas. Further, procedures for preparing a series of documents regarding the workings in the radiation area are automated to rapidly and properly provide the informations serving to the planning and designation for the radiation workings. As a result, the radiation managers' burnden can be mitigated and an efficient working management system can be provided, in view of the exposure management and personal management. (Kamimura, M.)

Biological impact of high-dose and dose-rate radiation exposure

International Nuclear Information System (INIS)

Maliev, V.; Popov, D.; Jones, J.; Gonda, S.; Prasad, K.; Viliam, C.; Haase, G.; Kirchin, V.; Rachael, C.

2006-01-01

Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

Biological impact of high-dose and dose-rate radiation exposure

Energy Technology Data Exchange (ETDEWEB)

Maliev, V.; Popov, D. [Russian Academy of Science, Vladicaucas (Russian Federation); Jones, J.; Gonda, S. [NASA -Johnson Space Center, Houston (United States); Prasad, K.; Viliam, C.; Haase, G. [Antioxida nt Research Institute, Premier Micronutrient Corporation, Novato (United States); Kirchin, V. [Moscow State Veterinary and Biotechnology Acade my, Moscow (Russian Federation); Rachael, C. [University Space Research Association, Colorado (United States)

2006-07-01

Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

Radiation research contracts: Biological effects of small radiation doses

Energy Technology Data Exchange (ETDEWEB)

Hug, O [International Atomic Energy Agency, Division of Health, Safety and Waste Disposal, Vienna (Austria)

1959-04-15

To establish the maximum permissible radiation doses for occupational and other kinds of radiation exposure, it is necessary to know those biological effects which can be produced by very small radiation doses. This particular field of radiation biology has not yet been sufficiently explored. This holds true for possible delayed damage after occupational radiation exposure over a period of many years as well as for acute reactions of the organism to single low level exposures. We know that irradiation of less than 25 Roentgen units (r) is unlikely to produce symptoms of radiation sickness. We have, however, found indications that even smaller doses may produce certain instantaneous reactions which must not be neglected

The feasibility of 10 keV X-ray as radiation source in total dose response radiation test

International Nuclear Information System (INIS)

Li Ruoyu; Li Bin; Luo Hongwei; Shi Qian

2005-01-01

The standard radiation source utilized in traditional total dose response radiation test is 60 Co, which is environment-threatening. X-rays, as a new radiation source, has the advantages such as safety, precise control of dose rate, strong intensity, possibility of wafer-level test or even on-line test, which greatly reduce cost for package, test and transportation. This paper discussed the feasibility of X-rays replacing 60 Co as the radiation source, based on the radiation mechanism and the effects of radiation on gate oxide. (authors)

The optimal dose of radiation in Hodgkin's disease: an analysis of clinical and treatment factors affecting in-field disease control

International Nuclear Information System (INIS)

Price Mendenhall, Nancy; Lewis Rodrigue, Lori; Moore-Higgs, Giselle J.; Marcus, Robert B.; Million, Rodney R.

1999-01-01

Purpose: The purpose of this study is to analyze the effect of radiation dose, as well as other clinical and therapeutic factors, on in-field disease control. Patients and Materials: The study population comprised 232 patients with Stage I and II Hodgkin's disease (HD) treated with curative intent at the University of Florida with radiotherapy (RT) alone (169 patients) or chemotherapy and radiotherapy (CMT) (63 patients). Sites of involvement and radiation doses were prospectively recorded and correlated with sites of disease recurrence. Results: Freedom from relapse and absolute survival rates at 10 years were as follows: 76% and 77%, entire group; 76% and 80%, RT group; 79% and 70%, CMT group; 85% and 78%, Stage I; and 71% and 77%, Stage II. Treatment failure occurred in 50 patients (22%) including in-field failure in 22 patients (9%). In-field failure was rare in electively treated sites. Multivariate analysis of clinical factors (tumor size, number of sites involved, B-symptoms, gender, histology, age, and site of involvement) and treatment factors (use of chemotherapy, number of cycles of chemotherapy, radiation dose, radiation treatment volume, and radiation treatment time) showed only tumor size (p = 0.0001) to be significantly correlated with in-field disease control. In RT patients, the in-field failure rate according to tumor size was as follows: 0% for ≤ 3 cm; 4% for > 3 cm and ≤ 6 cm; 23% for > 6 cm and ≤ 9 cm; and 36% for > 9 cm. In CMT patients, the in-field failure rate was as follows: 0% for ≤ 3 cm; 0% for > 3 and ≤ 6 cm; 5% for > 6 cm and ≤ 9 cm; and 26% for > 9 cm. In-field recurrence was not a predominant pattern of failure in RT patients with small tumors (≤ 6 cm); thus, the difference in in-field control in tumors ≤ 6 cm between doses ≤ 35 Gy (6%) and doses ≥ 36 Gy (0%) was not statistically significant. In larger tumors (> 6 cm), in-field recurrence was a predominant pattern of failure; the in-field failure rate in RT

Patient radiation dose during mammography procedures

International Nuclear Information System (INIS)

Mohamed, Swsan Awd Elkriem

2015-11-01

The objectives of this study were to estimate the patient dose in term of mean glandular dose and assist in optimization of radiation protection in mammographic procedures in Sudan. A total number of 107 patients were included. Four mammographic units were participated. Only one center was using automatic exposure control (AEC). The mean doses in (mGy) for the CC projection were 3.13, 1.24, 2.45 and 0.98 and for the MLO projection was 2.13, 1.26, 1.99 and 1.02 for centers A, B, C, and D, respectively. The total mean dose per breast from both projections was 5.26, 2.50, 4.44 and 1.99 mGy for centers A, B, C and D, respectively. The minimum mean glandular dose was found between the digital system which was operated under AEC and one of the manual selected exposure factors systems, this highlight possible optimization of radiation protection in the other manual selected systems. The kilo volt and the tube current time products should be selected correctly according to the breast thickness in both centers A and C. (author)

Analysis of the occupational doses of female radiation workers in India

Energy Technology Data Exchange (ETDEWEB)

Pardasani, P B; Joshi, V D; Awari, J M; Kher, R K [Bhabha Atomic Research Centre, Mumbai (India). Radiation Protection Services Div.

1994-04-01

Basis for control of occupational exposures of women are same as that of men except for pregnant women. Analysis of annual and cumulative occupational doses of female radiation workers as a group has been done. The average annual dose data in the four broad categories and age wise dose distribution is presented. The average working period for female radiation workers is about 3 to 5 years which is same as that of all the radiation workers on our records. The average cumulative dose for female workers is about 3 mSv. (author). 4 refs., 4 tabs.

Analysis of the occupational doses of female radiation workers in India

International Nuclear Information System (INIS)

Pardasani, P.B.; Joshi, V.D.; Awari, J.M.; Kher, R.K.

1994-01-01

Basis for control of occupational exposures of women are same as that of men except for pregnant women. Analysis of annual and cumulative occupational doses of female radiation workers as a group has been done. The average annual dose data in the four broad categories and age wise dose distribution is presented. The average working period for female radiation workers is about 3 to 5 years which is same as that of all the radiation workers on our records. The average cumulative dose for female workers is about 3 mSv. (author). 4 refs., 4 tabs

Effects of high dose rate gamma radiation on survival and reproduction of Biomphalaria glabrata

Energy Technology Data Exchange (ETDEWEB)

Cantinha, Rebeca S.; Nakano, Eliana [Instituto Butantan, Sao Paulo, SP (Brazil). Lab. de Parasitologia], e-mail: rebecanuclear@gmail.com, e-mail: eliananakano@butantan.gov.br; Borrely, Sueli I. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes], e-mail: sborrely@ipen.br; Amaral, Ademir; Melo, Ana M.M.A. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Energia Nuclear. Grupo de Estudos em Radioprotecao e Radioecologia (GERAR)], e-mail: amaral@ufpe.br; Silva, Luanna R.S. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Dept. de Biofisica e Radiobiologia. Lab. de Radiobiologia], e-mail: amdemelo@hotmail.com, e-mail: luannaribeiro_lua@hotmail.com

2009-07-01

Ionizing radiations are known as mutagenic agents, causing lethality and infertility. This characteristic has motivated its application on animal biological control. In this context, the freshwater snail Biomphalaria glabrata can be considered an excellent experimental model to study effects of ionizing radiations on lethality and reproduction. This work was designed to evaluate effects of {sup 60}Co gamma radiation at high dose rate (10.04 kGy/h) on B. glabrata. For this purpose, adult snails were selected and exposed to doses ranging from 20 to 100 Gy, with 10 Gy intervals; one group was kept as control. There was not effect of dose rate in the lethality of gamma radiation; the value of 64,3 Gy of LD{sub 50} obtained in our study was similar to that obtained by other authors with low dose rates. Nevertheless, our data suggest that there was a dose rate effect in the reproduction. On all dose levels, radiation improved the production of embryos for all exposed individuals. However, viability indexes were below 6% and, even 65 days after irradiation, fertility was not recovered. These results are not in agreement with other studies using low dose rates. Lethality was obtained in all groups irradiated, and the highest doses presented percentiles of dead animals above 50%. The results demonstrated that doses of 20 and 30 Gy were ideal for population control of B. glabrata. Further studies are needed; nevertheless, this research evidenced great potential of high dose rate gamma radiation on B. glabrata reproductive control. (author)

Effects of high dose rate gamma radiation on survival and reproduction of Biomphalaria glabrata

International Nuclear Information System (INIS)

Cantinha, Rebeca S.; Nakano, Eliana; Silva, Luanna R.S.

2009-01-01

Ionizing radiations are known as mutagenic agents, causing lethality and infertility. This characteristic has motivated its application on animal biological control. In this context, the freshwater snail Biomphalaria glabrata can be considered an excellent experimental model to study effects of ionizing radiations on lethality and reproduction. This work was designed to evaluate effects of 60 Co gamma radiation at high dose rate (10.04 kGy/h) on B. glabrata. For this purpose, adult snails were selected and exposed to doses ranging from 20 to 100 Gy, with 10 Gy intervals; one group was kept as control. There was not effect of dose rate in the lethality of gamma radiation; the value of 64,3 Gy of LD 50 obtained in our study was similar to that obtained by other authors with low dose rates. Nevertheless, our data suggest that there was a dose rate effect in the reproduction. On all dose levels, radiation improved the production of embryos for all exposed individuals. However, viability indexes were below 6% and, even 65 days after irradiation, fertility was not recovered. These results are not in agreement with other studies using low dose rates. Lethality was obtained in all groups irradiated, and the highest doses presented percentiles of dead animals above 50%. The results demonstrated that doses of 20 and 30 Gy were ideal for population control of B. glabrata. Further studies are needed; nevertheless, this research evidenced great potential of high dose rate gamma radiation on B. glabrata reproductive control. (author)

Effects of small radiation doses

International Nuclear Information System (INIS)

Fuchs, G.

1986-01-01

The term 'small radiation dosis' means doses of about (1 rem), fractions of one rem as well as doses of a few rem. Doses like these are encountered in various practical fields, e.g. in X-ray diagnosis, in the environment and in radiation protection rules. The knowledge about small doses is derived from the same two forces, on which the radiobiology of human beings nearly is based: interpretation of the Hiroshima and Nagasaki data, as well as the experience from radiotherapy. Careful interpretation of Hiroshima dates do not provide any evidence that small doses can induce cancer, fetal malformations or genetic damage. Yet in radiotherapy of various diseases, e.g. inflammations, doses of about 1 Gy (100 rad) do no harm to the patients. According to a widespread hypothesis even very small doses may induce some types of radiation damage ('no threshold'). Nevertheless an alternative view is justified. At present no decision can be made between these two alternatives, but the usefullness of radiology is definitely better established than any damage calculated by theories or extrapolations. Based on experience any exaggerated fear of radiations can be met. (author)

Radiation dose during angiographic procedures

International Nuclear Information System (INIS)

Lavoie, Ch.; Rasuli, P.

2001-01-01

The use of angiographic procedures is becoming more prevalent as new techniques and equipment are developed. There have been concerns in the scientific community about the level of radiation doses received by patients, and indirectly by staff, during some of these radiological procedures. The purpose of this study was to assess the level of radiation dose from angiographic procedures to patient at the Ottawa Hospital, General Campus. Radiation dose measurements, using Thermo-Luminescent Dosimeters (TLDs), were performed on more than 100 patients on various procedures. The results show that while the patient dose from the great majority of angiographic procedures is less than 2 Gy, a significant number of procedures, especially interventional procedures may have doses greater than 2 Gy and may lead to deterministic effects. (author)

Intussusception reduction: Effect of air vs. liquid enema on radiation dose

Energy Technology Data Exchange (ETDEWEB)

Kaplan, Summer L.; Edgar, J.C.; Anupindi, Sudha A.; Zhu, Xiaowei [The Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States); University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA (United States); Magill, Dennise; Felice, Marc A. [University of Pennsylvania, Environmental Health and Radiation Safety, Philadelphia, PA (United States)

2017-10-15

Both air and radiopaque liquid contrast are used to reduce ileocolic intussusception under fluoroscopy. Some suggest air lowers radiation dose due to shorter procedure times. However, air enema likely lowers radiation dose regardless of fluoroscopy time due to less density over the automatic exposure control cells. We test the hypothesis that air enema reduction of ileocolic intussusception results in lower radiation dose than liquid contrast enema independent of fluoroscopy time. We describe a role for automatic exposure control in this dose difference. We retrospectively evaluated air and liquid intussusception reductions performed on a single digital fluoroscopic unit during a 26-month period. We compared patient age, weight, gender, exam time of day and year, performing radiologist(s), radiographic image acquisitions, grid and magnification use, fluoroscopy time and dose area product. We compared categorical and continuous variables statistically using chi-square and Mann-Whitney U tests, respectively. The mean dose area product was 2.7-fold lower for air enema, 1.3 ± 0.9 dGy.cm{sup 2}, than for liquid, 3.5 ± 2.5 dGy.cm{sup 2} (P<0.005). The mean fluoroscopy time was similar between techniques. The mean dose area product/min was 2.3-fold lower for air, 0.6 ± 0.2 dGy.cm{sup 2}/min, than for liquid, 1.4 ± 0.5 dGy.cm{sup 2}/min (P<0.001). No group differences were identified in other measured dose parameters. Fluoroscopic intussusception reduction using air enema uses less than half the radiation dose of liquid contrast enema. Dose savings are independent of fluoroscopy time and are likely due to automatic exposure control interaction. (orig.)

Radiation dose-reduction strategies in thoracic CT.

Science.gov (United States)

Moser, J B; Sheard, S L; Edyvean, S; Vlahos, I

2017-05-01

Modern computed tomography (CT) machines have the capability to perform thoracic CT for a range of clinical indications at increasingly low radiation doses. This article reviews several factors, both technical and patient-related, that can affect radiation dose and discusses current dose-reduction methods relevant to thoracic imaging through a review of current techniques in CT acquisition and image reconstruction. The fine balance between low radiation dose and high image quality is considered throughout, with an emphasis on obtaining diagnostic quality imaging at the lowest achievable radiation dose. The risks of excessive radiation dose reduction are also considered. Inappropriately low dose may result in suboptimal or non-diagnostic imaging that may reduce diagnostic confidence, impair diagnosis, or result in repeat examinations incurring incremental ionising radiation exposure. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Are low radiation doses Dangerous?

International Nuclear Information System (INIS)

Garcia Lima, O.; Cornejo, N.

1996-01-01

In the last few years the answers to this questions has been affirmative as well as negative from a radiation protection point of view low doses of ionizing radiation potentially constitute an agent causing stochasting effects. A lineal relation without threshold is assumed between dose and probability of occurrence of these effects . Arguments against the danger of probability of occurrence of these effects. Arguments again the danger of low dose radiation are reflected in concepts such as Hormesis and adaptive response, which are phenomena that being studied at present

Analysis of CT radiation dose based on radiation-dose-structured reports

International Nuclear Information System (INIS)

Wang Weipeng; Zhang Yi; Zhang Menglong; Zhang Dapeng; Song Shaojuan

2014-01-01

Objective: To analyse the CT radiation dose statistically using the standardized radiation-dose-structured report (RDSR) of digital imaging and communications in medicine (DICOM). Methods: Using the self-designed software, 1230 RDSR files about CT examination were obtained searching on the picture archiving and communication system (PACS). The patient dose database was established by combination of the extracted relevant information with the scanned sites. The patients were divided into adult group (over 10 years) and child groups (0-1 year, 1-5 years, 5-10 years) according to the age. The average volume CT dose index (CTDI vol ) and dose length product (DLP) of all scans were recorded respectively, and then the effective dose (E) was estimated. The DLP value at 75% quantile was calculated and compared with the diagnostic reference level (DRL). Results: In adult group, CTDI vol and DLP values were moderately and positively correlated (r = 0.41), the highest E was observed in upper abdominal enhanced scan, and the DLP value at 75% quantile was 60% higher than DRL. In child group, their CTDI vol in group of 5-10 years was greater than that in groups of 0-1 and 1-5 years (t = 2.42, 2.04, P < 0.05); the DLP value was slightly and positively correlated with the age (r = 0.16), while E was moderately and negatively correlated with the age (r = -0.48). Conclusions: It is a simple and efficient method to use RDSR to obtain the radiation doses of patients. With the popularization of the new equipment and the application of regionalized medical platform, RDSR would become the main tool for the dosimetric level surveying and individual dose recording. (authors)

''Low dose'' and/or ''high dose'' in radiation protection: A need to setting criteria for dose classification

International Nuclear Information System (INIS)

Sohrabi, M.

1997-01-01

The ''low dose'' and/or ''high dose'' of ionizing radiation are common terms widely used in radiation applications, radiation protection and radiobiology, and natural radiation environment. Reading the title, the papers of this interesting and highly important conference and the related literature, one can simply raise the question; ''What are the levels and/or criteria for defining a low dose or a high dose of ionizing radiation?''. This is due to the fact that the criteria for these terms and for dose levels between these two extreme quantities have not yet been set, so that the terms relatively lower doses or higher doses are usually applied. Therefore, setting criteria for classification of radiation doses in the above mentioned areas seems a vital need. The author while realizing the existing problems to achieve this important task, has made efforts in this paper to justify this need and has proposed some criteria, in particular for the classification of natural radiation areas, based on a system of dose limitation. (author)

Transperineal high-dose-rate interstitial radiation therapy in the management of gynecologic malignancies

Energy Technology Data Exchange (ETDEWEB)

Itami, Jun; Hara, Ryuseke; Kozuka, Takuyou; Yamashita, Hideomi; Nakajima, Kaori; Shibata, Kouji; Abe, Yoshihisa; Fuse, Masashi; Ito, Masashi [International Medical Center of Japan, Tokyo (Japan). Dept. of Radiation Therapy and Oncology

2003-11-01

Background: High-dose-rate interstitial radiation therapy is a newly introduced modality, and its role in the management of gynecologic malignancies remains to be studied. Clinical experience in high-dose-rate interstitial radiation therapy was retrospectively investigated. Patients and Methods: Eight patients with primary and nine with recurrent gynecologic malignancies underwent high-dose-rate interstitial radiation therapy with/without external-beam irradiation. Fractional dose of the high-dose-rate interstitial radiation therapy ranged between 4 and 6 Gy with total doses of 15-54 Gy. Interstitial irradiation was performed twice daily with an interval of > 6 h. Results: 2-year local control rate was 75% for primary treatment and 47% for treatment of recurrence (p = 0.46). Maximum tumor size had a statistically significant impact on local control (p < 0.002). Grade 2 and 4 late complications were seen in five patients, and the incidence was significantly higher in patients with a larger volume enclosed by the prescribed fractional dose of high-dose-rate interstitial radiation therapy. The incidence of grade 2 and 4 complications at 18 months was 78% and 0% with a volume > 100 cm{sup 3} and {<=} 100 cm{sup 3}, respectively (p < 0.04). Conclusion: Although high-dose-rate interstitial radiation therapy is a promising modality, it must be applied cautiously to patients with bulky tumors because of the high incidence of serious complications. (orig.)

Do dose area product meter measurements reflect radiation doses ...

African Journals Online (AJOL)

Enrique

SA JOURNAL OF RADIOLOGY • August 2004. Abstract. This study determined the correlation between radiation doses absorbed by health care workers and dose area product meter (DAP) measurements at Universitas Hospital, Bloemfontein. The DAP is an instrument which accurately measures the radiation emitted from ...

Do dose area product meter measurements reflect radiation doses ...

African Journals Online (AJOL)

This study determined the correlation between radiation doses absorbed by health care workers and dose area product meter (DAP) measurements at Universitas Hospital, Bloemfontein. The DAP is an instrument which accurately measures the radiation emitted from the source. The study included the interventional ...

KERMA-based radiation dose management system for real-time patient dose measurement

Science.gov (United States)

Kim, Kyo-Tae; Heo, Ye-Ji; Oh, Kyung-Min; Nam, Sang-Hee; Kang, Sang-Sik; Park, Ji-Koon; Song, Yong-Keun; Park, Sung-Kwang

2016-07-01

Because systems that reduce radiation exposure during diagnostic procedures must be developed, significant time and financial resources have been invested in constructing radiation dose management systems. In the present study, the characteristics of an existing ionization-based system were compared to those of a system based on the kinetic energy released per unit mass (KERMA). Furthermore, the feasibility of using the KERMA-based system for patient radiation dose management was verified. The ionization-based system corrected the effects resulting from radiation parameter perturbations in general radiography whereas the KERMA-based system did not. Because of this difference, the KERMA-based radiation dose management system might overestimate the patient's radiation dose due to changes in the radiation conditions. Therefore, if a correction factor describing the correlation between the systems is applied to resolve this issue, then a radiation dose management system can be developed that will enable real-time measurement of the patient's radiation exposure and acquisition of diagnostic images.

The effect of well-characterized, very low-dose x-ray radiation on fibroblasts.

Science.gov (United States)

Truong, Katelyn; Bradley, Suzanne; Baginski, Bryana; Wilson, Joseph R; Medlin, Donald; Zheng, Leon; Wilson, R Kevin; Rusin, Matthew; Takacs, Endre; Dean, Delphine

2018-01-01

The purpose of this study is to determine the effects of low-dose radiation on fibroblast cells irradiated by spectrally and dosimetrically well-characterized soft x-rays. To achieve this, a new cell culture x-ray irradiation system was designed. This system generates characteristic fluorescent x-rays to irradiate the cell culture with x-rays of well-defined energies and doses. 3T3 fibroblast cells were cultured in cups with Mylar® surfaces and were irradiated for one hour with characteristic iron (Fe) K x-ray radiation at a dose rate of approximately 550 μGy/hr. Cell proliferation, total protein analysis, flow cytometry, and cell staining were performed on fibroblast cells to determine the various effects caused by the radiation. Irradiated cells demonstrated increased proliferation and protein production compared to control samples. Flow cytometry revealed that a higher percentage of irradiated cells were in the G0/G1 phase of the cell cycle compared to control counterparts, which is consistent with other low-dose studies. Cell staining results suggest that irradiated cells maintained normal cell functions after radiation exposure, as there were no qualitative differences between the images of the control and irradiated samples. The result of this study suggest that low-dose soft x-ray radiation might cause an initial pause, followed by a significant increase, in proliferation. An initial "pause" in cell proliferation could be a protective mechanism of the cells to minimize DNA damage caused by radiation exposure. The new cell irradiation system developed here allows for unprecedented control over the properties of the x-rays given to the cell cultures. This will allow for further studies on various cell types with known spectral distribution and carefully measured doses of radiation, which may help to elucidate the mechanisms behind varied cell responses to low-dose x-rays reported in the literature.

Annual radiation dose in thermoluminescence dating

International Nuclear Information System (INIS)

Li Huhou

1988-01-01

The annual radiation dose in thermoluminescence dating has been discussed. The autor gives an entirely new concept of the enviromental radiation in the thermoluminescence dating. Methods of annual dose detemination used by author are dating. Methods of annual dose determination used by author are summed up, and the results of different methods are compared. The emanium escapiug of three radioactive decay serieses in nature has been considered, and several determination methods are described. The contribution of cosmic rays for the annual radiation dose has been mentioned

Annual radiation dose in thermoluminescence dating

Energy Technology Data Exchange (ETDEWEB)

Huhou, Li [Chinese Academy of Social Sciences, Beijing, BJ (China). Inst. of Archaeology

1988-11-01

The annual radiation dose in thermoluminescence dating has been discussed. The autor gives an entirely new concept of the enviromental radiation in the thermoluminescence dating. Methods of annual dose detemination used by author are dating. Methods of annual dose determination used by author are summed up, and the results of different methods are compared. The emanium escapiug of three radioactive decay serieses in nature has been considered, and several determination methods are described. The contribution of cosmic rays for the annual radiation dose has been mentioned.

We can do better than effective dose for estimating or comparing low-dose radiation risks

International Nuclear Information System (INIS)

Brenner, D.J.

2012-01-01

The effective dose concept was designed to compare the generic risks of exposure to different radiation fields. More commonly these days, it is used to estimate or compare radiation-induced cancer risks. For various reasons, effective dose represents flawed science: for instance, the tissue-specific weighting factors used to calculate effective dose are a subjective mix of different endpoints; and the marked and differing age and gender dependencies for different health detriment endpoints are not taken into account. This paper suggests that effective dose could be replaced with a new quantity, ‘effective risk’, which, like effective dose, is a weighted sum of equivalent doses to different tissues. Unlike effective dose, where the tissue-dependent weighting factors are a set of generic, subjective committee-defined numbers, the weighting factors for effective risk are simply evaluated tissue-specific lifetime cancer risks per unit equivalent dose. Effective risk, which has the potential to be age and gender specific if desired, would perform the same comparative role as effective dose, be just as easy to estimate, be less prone to misuse, be more directly understandable, and would be based on solid science. An added major advantage is that it gives the users some feel for the actual numerical values of the radiation risks they are trying to control.

Assessment and recording of radiation doses to workers

International Nuclear Information System (INIS)

1986-01-01

The assessment and recording of the radiation exposure of workers in activities involving radiation risks are required for demonstrating compliance with institutional dose limitations and for a number of other complementary purposes. A significant proportion of the labor force involved in radiation work is currently represented by those specialised workers who operate as itinerant contractors for different nuclear installations and in different countries. In order to ensure that the exposure of these workers is adequately and consistently controlled and kept within acceptable limits, there is a need for the criteria and methods for dose assessment and recording to be harmonised throughout the different countries. An attempt in that direction has been made in this report, which has been prepared by a group of experts convened by the Committee on Radiation Protection and Public Health of the OECD Nuclear Energy Agency. Its primary purpose is to describe recommended technical procedures for an unified approach to the assessment and recording of worker doses. The report is published under the responsibility of the Secretary-General of the OECD, and does not commit Member governments

Analysis of radiation doses to patients from diagnostic department of nuclear medicine

International Nuclear Information System (INIS)

Lepej, L.; Messingerova, M.

1995-01-01

In this paper the values of mean effective dose equivalents per unit activity (H E/1Bq ) were used for the calculation of mean effective dose equivalents for one examination (H E ). The collective effective dose equivalents for each radiopharmaceutical and type of examination (S ER ) and global collective effective dose equivalent for department for all radiopharmaceuticals (S E ) during evaluated period were defined. The data for years from 1992 to 1994 were evaluated and compared with results in literature. The evaluation of radiation doses in nuclear medicine department is useful parameter for internal quality control. Using this method, the radiation dose in this laboratory was changed to minimum (under mean value of Slovak Republic). Unfortunately, the real data of patients radiation doses are different from the calculated one. Due to different kinetic of radiopharmaceuticals in individual patients (influenced by pathology, age, etc.) the evaluation of radiation burden to nuclear medicine patients is problematic. But this approach enable the relative comparison of the changes in values of H E and S E during the observed period. The evaluation of individual (minimal) effective dose equivalent - (H min ) which represents dose calculated under physiologic conditions can be useful for indication of diagnostic examination by physicians. Therefore the systematic registration of H min from all examinations - patient's radiation history. This is specially important in the case of children and young people. The importance of the proposed method, is in regulation of radiation dose from nuclear medicine diagnostic examinations, not only be the control of number and type of examinations, but also by selection of used radiopharmaceuticals and by the way how to use them. (J.K.) 1 fig., 2 refs

Hormesis of Low Doses of Ionizing Radiation Exposure on Immune System

International Nuclear Information System (INIS)

Ragab, M.H.; Abbas, M.O.; El-Asady, R.S.; Amer, H.A.; El-Khouly, W.A.; Shabon, M.H.

2015-01-01

The effect of low doses of ionizing radiation on the immune system has been a controversial subject. To evaluate the effect of low-doses γ-irradiation exposure on immune system. An animal model, using Rattus Rattus rats was used. The rats were divided into groups exposed to either continuous or fractionated 100, 200, 300, 400 and 500 mSv of radiation and compared to control rats that did not receive radiation. All groups were exposed to a total white blood count (Wcs), lymphocyte count and serum IgG level measurement, as indicators of the function of the cell-mediated (T lymphocytes) and the humoral (B lymphocytes) immune system. The results of the current study revealed that the counts of total leukocytes (WBCs) and lymphocytes, as well as the serum level of IgG were increased significantly in rats receiving low dose radiation, indicating enhancement of immune system. The data suggests that low-dose gamma-radiation improved hematological parameters and significantly enhances immune response indices of the exposed rats. These findings are similar to the radiation adaptive responses in which a small dose of pre irradiation would induce certain radiation resistance and enhances the cell response after exposure to further irradiation doses The applied low doses used in the present study may appear effective inducing the radio adaptive response. Farooqi and Kesavan (1993) and Bravard et al. (1999) reported that the adaptive response to ionizing radiation refers to the phenomenon by which cells irradiated with low (cGy) or sublethal doses (conditioning doses) become less susceptible to genotoxic effects of a subsequent high dose (challenge dose, several Gy).

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

Science.gov (United States)

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

2006-01-01

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

Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

Energy Technology Data Exchange (ETDEWEB)

Koga, Taeko; Morishima, Hiroshige [Kinki Univ., Atomic Energy Research Institute, Osaka (Japan); Tatsumi, Kusuo [Kinki Univ., Life Science Research Institute, Osaka (Japan); Nakai, Sayaka; Sugahara, Tsutomu [Health Research Foundation, Kyoto (Japan); Yuan Yongling [Labor Hygiene Institute of Hunan Prov. (China); Wei Luxin [Laboratory of Industorial Hygiene, Ministry of Health (China)

2001-01-01

As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: (1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. (2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

Dose measurement, its distribution and individual external dose assessments of inhabitants on high background radiation area in China

International Nuclear Information System (INIS)

Koga, Taeko; Morishima, Hiroshige; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2001-01-01

As a part of the China-Japan cooperative research on the natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external to natural radiation in the high background radiation area (HBRA) of Yangjiang in Guangdong province and in the control area (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by the personal dosimeters, an indirect method was applied to estimate the exposed dose rates from the environmental radiation dose rates measured by survey meters and the occupancy factors of each hamlet. An individual radiation dose roughly correlates with the environmental radiation dose and the life style of the inhabitant. We have analyzed the environmental radiation doses in the hamlets and the variation of the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and the several hamlets of the different level doses in HBRA and Hampizai hamlet in CA. With these parameters, we made estimations of individual dose rates and compared them with those obtained from the direct measurement using dosimeters carried by selected individuals. The results obtained are as follows: 1) The environmental radiation dose rates are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiation. The indoor radiation dose rates were due to the exposure from the natural radioactive nuclides in the building materials and they were about twice higher than the outdoor radiation dose rates. This difference was not observed in CA. 2) The occupancy factor was affected by the age of individuals and the seasons of a year. Indoor occupancy factors were higher for infants and aged individuals than for other age groups. This lead to higher

Low-dose x-radiation and congenital anomalies

International Nuclear Information System (INIS)

Kameyama, Yoshiro

1983-01-01

Among radiation effects on developing embryos and fetuses, occurrence of germinal mutation due to exposure of the gonads and postnatal manifestation of neoplasms are considered to be stochastic effects from the aspect of radiation protection. On the other hand, somatic effects such as teratogenic and embryo-toxic effects can be regarded as nonstochastic ones with threshold doses. In experimental teratological studies with mice and rats, the lowest radiation doses for manifestation of the non-stochastic somatic effects which have been recognized so far are:5 rad for resorption of preimplantation embryos; 5-10 rad for acute cytological changes such as pyknosis, cytoplasmic degeneration and mitotic delay; 5 rad for increasing frequency of spontaneous minor anomalies of the skeleton; 15-20 rad for malformations of the eye, brain and spinal cord; 20-25 rad for histogenetic and functional disorders of the central nervous system; and 20-25 rad for impaired fertility. Pregnant women who are subject to X-ray examinations are much concerned about potential hazard of radiation to their offspring in utero. The above experimental findings suggest that the possibility of non-stochastic somatic effects of diagnostic radiation on human embryos and fetuses is extremely low, and probably negligible, given the proper dose control measures. Possible effects which should be considered for risk evaluation of diagnostic exposure are two stochastic effects, carcinogenic and mutagenic. (author)

Radiation Protection Control Area Around Baggage Control X-ray Units

International Nuclear Information System (INIS)

Prlic, I.; Radalj, Z.; Milkovic-Kraus, S.; Cerovac, Z.

2003-01-01

The importance of prompt occupational dose reporting rises when dose is received within a short-time interval or when the radiation source suffers any technical failures. Radiation exposure is to be recognized as a private/or group hazard of each person alone. Actual radiation quality of the source is to be taken into account. To optimize the radiological radiation protection Quality Control measurements of the source are done. We have developed digital dosemeters of type ALARA OD2 for external dosimetry to be used for establishing the real pattern of occupational dose delivered to the workers or/and as the (Ort) professional environmental measuring station. We are using dosemeter to define the control areas and areas of concern - point (Ort) around the source. This upgrade to legal obligatory external (film badge) dosimetry will help us to ease defining the professional stuff and working places which are actually exposed to ionising radiation of concern and for which it is necessary to provide legally required, or even additional, occupational health care programme. This means the analysis of exposure situations for specific jobs near the X-ray equipment used for baggage control in the context of carrying out a detailed study for the optimisation of radiation protection. PC data readout from device forms a real time exposure dose rate pattern that proves that any worker or other employee working nearby the baggage X-ray unit is not obliged to undergo any legal occupational monitoring (dosimetry or health) hence the total dose per year will not exceed 1 mSv under the worst working conditions. (author)

Health effect of low dose/low dose rate radiation

International Nuclear Information System (INIS)

Kodama, Seiji

2012-01-01

The clarified and non-clarified scientific knowledge is discussed to consider the cause of confusion of explanation of the title subject. The low dose is defined roughly lower than 200 mGy and low dose rate, 0.05 mGy/min. The health effect is evaluated from 2 aspects of clinical symptom/radiation hazard protection. In the clinical aspect, the effect is classified in physical (early and late) and genetic ones, and is classified in stochastic (no threshold value, TV) and deterministic (with TV) ones from the radioprotection aspect. Although the absence of TV in the carcinogenic and genetic effects has not been proved, ICRP employs the stochastic standpoint from the safety aspect for radioprotection. The lowest human TV known now is 100 mGy, meaning that human deterministic effect would not be generated below this dose. Genetic deterministic effect can be observable only in animal experiments. These facts suggest that the practical risk of exposure to <100 mGy in human is the carcinogenesis. The relationship between carcinogenic risk in A-bomb survivors and their exposed dose are found fitted to the linear no TV model, but the epidemiologic data, because of restriction of subject number analyzed, do not always mean that the model is applicable even below the dose <100 mGy. This would be one of confusing causes in explanation: no carcinogenic risk at <100 mGy or risk linear to dose even at <100 mGy, neither of which is scientifically conclusive at present. Also mentioned is the scarce risk of cancer in residents living in the high background radiation regions in the world in comparison with that in the A-bomb survivors exposed to the chronic or acute low dose/dose rate. Molecular events are explained for the low-dose radiation-induced DNA damage and its repair, gene mutation and chromosome aberration, hypothesis of carcinogenesis by mutation, and non-targeting effect of radiation (bystander effect and gene instability). Further researches to elucidate the low dose

Radiation absorbed doses in cephalography

International Nuclear Information System (INIS)

Eliasson, S.; Julin, P.; Richter, S.; Stenstroem, B.

1984-01-01

Radiation absorbed doses to different organs in the head and neck region in lateral (LAT) and postero-anterior (PA) cephalography were investigated. The doses were measured by thermoluminescence dosimeters (TLD) on a tissue equivalent phantom head. Lanthanide screens in speed group 4 were used at 90 and 85 k Vp. A near-focus aluminium dodger was used and the radiation beam was collimated strictly to the face. The maximum entrance dose from LAT was 0.25 mGy and 0.42 mGy from a PA exposure. The doses to the salivary glands ranged between 0.2 and 0.02 mGy at LAT and between 0.15 and 0.04 mGy at PA exposures. The average thyroid gland dose without any shielding was 0.11 mGy (LAT) and 0.06 mGy (PA). When a dodger was used the dose was reduced to 0.07 mGy (LAT). If the thyroid gland was sheilded off, the dose was further reduced to 0.01 mGy and if the thyroid region was collimated out of the primary radiation field the dose was reduced to only 0.005 mGy. (authors)

Radiation dose estimates for radiopharmaceuticals

International Nuclear Information System (INIS)

Stabin, M.G.; Stubbs, J.B.; Toohey, R.E.

1996-04-01

Tables of radiation dose estimates based on the Cristy-Eckerman adult male phantom are provided for a number of radiopharmaceuticals commonly used in nuclear medicine. Radiation dose estimates are listed for all major source organs, and several other organs of interest. The dose estimates were calculated using the MIRD Technique as implemented in the MIRDOSE3 computer code, developed by the Oak Ridge Institute for Science and Education, Radiation Internal Dose Information Center. In this code, residence times for source organs are used with decay data from the MIRD Radionuclide Data and Decay Schemes to produce estimates of radiation dose to organs of standardized phantoms representing individuals of different ages. The adult male phantom of the Cristy-Eckerman phantom series is different from the MIRD 5, or Reference Man phantom in several aspects, the most important of which is the difference in the masses and absorbed fractions for the active (red) marrow. The absorbed fractions for flow energy photons striking the marrow are also different. Other minor differences exist, but are not likely to significantly affect dose estimates calculated with the two phantoms. Assumptions which support each of the dose estimates appears at the bottom of the table of estimates for a given radiopharmaceutical. In most cases, the model kinetics or organ residence times are explicitly given. The results presented here can easily be extended to include other radiopharmaceuticals or phantoms

Cytogenetic effects of low-dose radiation

International Nuclear Information System (INIS)

Metalli, P.

1983-01-01

The effects of ionizing radiation on chromosomes have been known for several decades and dose-effect relationships are also fairly well established in the mid- and high-dose and dose-rate range for chromosomes of mammalian cells. In the range of low doses and dose rates of different types of radiation few data are available for direct analysis of the dose-effect relationships, and extrapolation from high to low doses is still the unavoidable approach in many cases of interest for risk assessment. A review is presented of the data actually available and of the attempts that have been made to obtain possible generalizations. Attention is focused on some specific chromosomal anomalies experimentally induced by radiation (such as reciprocal translocations and aneuploidies in germinal cells) and on their relevance for the human situation. (author)

Validation of radiation dose estimations in VRdose: comparing estimated radiation doses with observed radiation doses

International Nuclear Information System (INIS)

Nystad, Espen; Sebok, Angelia; Meyer, Geir

2004-04-01

The Halden Virtual Reality Centre has developed work-planning software that predicts the radiation exposure of workers in contaminated areas. To validate the accuracy of the predicted radiation dosages, it is necessary to compare predicted doses to actual dosages. During an experimental study conducted at the Halden Boiling Water Reactor (HBWR) hall, the radiation exposure was measured for all participants throughout the test session, ref. HWR-681 [3]. Data from this experimental study have also been used to model tasks in the work-planning software and gather data for predicted radiation exposure. Two different methods were used to predict radiation dosages; one method used all radiation data from all the floor levels in the HBWR (all-data method). The other used only data from the floor level where the task was conducted (isolated data method). The study showed that the all-data method gave predictions that were on average 2.3 times higher than the actual radiation dosages. The isolated-data method gave predictions on average 0.9 times the actual dosages. (Author)

Prenatal radiation doses from radiopharmaceuticals

International Nuclear Information System (INIS)

Rojo, A.M.; Gomez Parada, I.M.; Di Trano, J.L.

1998-01-01

The radiopharmaceutical administration with diagnostic or therapeutic purpose during pregnancy implies a prenatal radiation dose. The dose assessment and the evaluation of the radiological risks become relevant due to the great radiosensitivity of the fetal tissues in development. This paper is a revision of the available data for estimating fetal doses in the cases of the more frequently used radiopharmaceuticals in nuclear medicine, taking into account recent investigation in placental crossover. The more frequent diagnostic and therapeutic procedures were analyzed according to the radiation doses implied. (author) [es

Does fast-neutron radiotherapy merely reduce the radiation dose

International Nuclear Information System (INIS)

Ando, Koichi

1984-01-01

We examined whether fast-neutron radiotherapy is superior to low-LET radiotherpy by comparing the relationship between cell survival and tumor control probabilities after exposure of tumor-bearing (species) to the two modalities. Analysis based on TCD 50 assay and lung colony assay indicated that single dose of fast neutron achieved animal cures at higher survival rates than other radiation modalities including single and fractionated γ-ray doses, fractionated doses of fast neutron, and the mixed-beam scheme with a sequence of N-γ-γ-γ-N. We conclude that fast-neutron radiotherapy cured animal tumors with lower cell killing rates other radiation modalities. (author)

Doses from radiation exposure

International Nuclear Information System (INIS)

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

2012-01-01

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

Operation of the radiation dose registration system for decontamination and related works

International Nuclear Information System (INIS)

Ogawa, Tsubasa; Yasutake, Tsuneo; Itoh, Atsuo; Miyabe, Kenjiro

2017-01-01

The radiation dose registration system for decontamination and related works was established on 15 November 2013. Radiation dose registration center and primary contractors of decontamination and related works manage decontamination registration and management system. As of 31 March 2017, 384 primary contractors joined in the radiation dose registration system for decontamination and related works. 383,087 quarterly exposure dose records for decontamination and related works were registered. Based on the registered data provided by the primary contractors, radiation dose registration center has released the statistical data that represent the radiation control status for workers engaged in radiation work at the work areas of decontamination and related works, etc. The statistical data shows that there were 40,377 workers engaged in decontamination and related works in 2015. The average exposure dose for workers was 0.6 mSv in 2015. The maximum exposure dose for workers was 7.8 mSv in 2015. Dose distribution by age of workers shows the range of 60 to 64 years old were most engaged in decontamination and related works in 2015. Dose distribution by gender of workers shows 97% of workers were male in 2015. From 2012 to 2015, about 95% of workers were exposed to radiation less than 3 mSv. And about 80% of workers were exposed to radiation less than 1 mSv. The average exposure dose per year was ranged from 0.5 to 0.7 mSv. (author)

Radiation doses to neonates and issues of radiation protection in a special care baby unit

International Nuclear Information System (INIS)

Armpilia, C.I.; Fife, I.A.J.; Croasdale, P.L.

2001-01-01

Radiographs are most commonly taken in the neonatal period to assist in the diagnosis and management of respiratory difficulties. Frequent accurate radiographic assessment is required and a knowledge of the radiation dose is necessary to make the justification of such exposures. A survey of radiation doses to neonates from diagnostic X-ray examinations (chest and abdomen) has been carried out in the special care baby unit (SCBU) of the Royal Free Hospital. Entrance surface dose (ESD) was calculated from Quality Control measurements on the X-ray set itself. Direct measurement of radiation doses was also performed using highly sensitive thermoluminescence dosimeters (LiF:Mg,Cu,P), calibrated and tested for consistency in sensitivity. The mean ESD per radiograph was calculated to be 36μGy (with a standard deviation of 6μGy), averaged over 95 X-ray examinations. The ESD's as derived from the TLD crystals, ranged from 18μGy to 60μGy. The mean energy imparted (EI) and the mean whole body dose per radiograph were estimated to be 14μJ and 10μGy respectively. Assuming that neonates and foetuses are equally susceptible to carcinogenic effects of radiation (it involves an overestimation of risk), the radiation risk of childhood cancer from a single radiograph was estimated to be of the order (0.3-1.3)x10 -6 . Radiation doses compared favourably with the reference value of 80μGy ESD published by CEC in 1996. (author)

Determination of the radiation dose to the body due to external radiation

International Nuclear Information System (INIS)

Drexler, G.; Eckerl, H.

1985-01-01

Section 63 of the Radiation Protection Ordinance defines the basic requirement, determination of radiation dose to the body. The determination of dose equivalents for the body is the basic step in practical monitoring of dose equivalents or dose limits with regard to individuals or population groups, both for constant or varying conditions of exposure. The main field of monitoring activities is the protection of persons occupationally exposed to ionizing radiation. Conversion factors between body doses and radiation quantities are explained. (DG) [de

Assessment of dose level of ionizing radiation in army scrap

International Nuclear Information System (INIS)

Abdel Hamid, S. M.

2010-12-01

Radiation protection is the science of protecting people and the environment from the harmful effects of ionizing radiation, which includes both particle radiation and high energy radiation. Ionizing radiation is widely used in industry and medicine. Any human activity of nuclear technologies should be linked to the foundation of scientific methodology and baseline radiation culture to avoid risk of radiation and should be working with radioactive materials and expertise to understand, control practices in order to avoid risks that could cause harm to human and environment. The study was conducted in warehouses and building of Sudan air force Khartoum basic air force during September 2010. The goal of this study to estimate the radiation dose and measurement of radioactive contamination of aircraft scrap equipment and increase the culture of radiological safety as well as the concept of radiation protection. The results showed that there is no pollution observed in the contents of the aircraft and the spire part stores outside, levels of radiation dose for the all contents of the aircraft and spire part within the excitable level, except temperature sensors estimated radiation dose about 43 μSv/h outside of the shielding and 12 μSv/h inside the shielding that exceeded the internationally recommended dose level. One of the most important of the identification of eighteen (18) radiation sources used in temperature and fuel level sensors. These are separated from the scrap, collected and stored in safe place. (Author)

Effects of low dose radiation and epigenetic regulation

International Nuclear Information System (INIS)

Jiao Benzheng; Ma Shumei; Yi Heqing; Kong Dejuan; Zhao Guangtong; Gao Lin; Liu Xiaodong

2010-01-01

Purpose: To conclude the relationship between epigenetics regulation and radiation responses, especially in low-dose area. Methods: The literature was examined for papers related to the topics of DNA methylation, histone modifications, chromatin remodeling and non-coding RNA modulation in low-dose radiation responses. Results: DNA methylation and radiation can regulate reciprocally, especially in low-dose radiation responses. The relationship between histone methylation and radiation mainly exists in the high-dose radiation area; histone deacetylase (HDAC) inhibitors show a promising application to enhance radiation sensitivity, no matter whether in low-dose or high-dose areas; the connection between γ-H2AX and LDR has been remained unknown, although γ-H2AX has been shown no radiation sensitivities with 1-15 Gy irradiation; histone ubiquitination play an important role in DNA damage repair mechanism. Moreover, chromatin remodeling has an integral role in DSB repair and the chromatin response, in general, may be precede DNA end resection. Finally, the effect of radiation on miRNA expression seems to vary according to cell type, radiation dose, and post-irradiation time point. Conclusion: Although the advance of epigenetic regulation on radiation responses, which we are managing to elucidate in this review, has been concluded, there are many questions and blind blots deserved to investigated, especially in low-dose radiation area. However, as progress on epigenetics, we believe that many new elements will be identified in the low-dose radiation responses which may put new sights into the mechanisms of radiation responses and radiotherapy. (authors)

Radiation response of industrial materials: Dose-rate and morphology implications

International Nuclear Information System (INIS)

Berejka, Anthony J.

2007-01-01

Industrial uses of ionizing radiation mostly rely upon high current, high dose-rate (100 kGy/s) electron beam (EB) accelerators. To a lesser extent, industry uses low dose-rate (2.8 x 10 -3 kGy/s) radioactive Cobalt-60 as a gamma source, generally for some rather specific purposes, as medical device sterilization and the treatment of food and foodstuffs. There are nearly nine times as many (∼1400) high current EB units in commercial operation than gamma sources (∼160). However, gamma sources can be easily scaled-down so that much research on materials effects is conducted using gamma radiation. Likewise, laboratories are more likely to have very low beam current and consequently low dose-rate accelerators such as Van de Graaff generators and linear accelerators. With the advent of very high current EB accelerators, X-ray processing has become an industrially viable option. With X-rays from high power sources, dose-rates can be modulated based upon accelerator power and the attenuation of the X-ray by the distance of the material from the X-ray target. Dose and dose-rate dependence has been found to be of consequence in several commercial applications which can employ the use of ionizing radiation. The combination of dose and dose-rate dependence of the polymerization and crosslinking of wood impregnants and of fiber composite matrix materials can yield more economically viable results which have promising commercial potential. Monomer and oligomer structure also play an important role in attaining these desirable results. The influence of morphology is shown on the radiation response of olefin polymers, such as ethylene, propylene and isobutylene polymers and their copolymers. Both controlled morphology and controlled dose-rate have commercial consequences. These are also impacted both by the adroit selection of materials and through the possible use of X-ray processing

Biochemical and immunological responses to low doses of ionizing radiation

International Nuclear Information System (INIS)

Shabon, M.H.; Sayed, Z.S.; Mahdy, E.M.; El-Gawish, M.A.; Shosha, W.

2006-01-01

Malondialdehyde, lactate dehydrogenase, iron concentration, IL-6 and IL-1b concentration, hemoglobin content, red cells, white cells and platelet counts were determined in seventy-two male albino rats divided into two main groups. The first one was subdivided into 7 subgroups; control and 6 irradiated subgroups with 0.1, 0.2, 0.3, 0.5, 0.7 and 1 Gy single dose of gamma radiation. The other was subdivided into 4 subgroups irradiated with fractionated doses of gamma radiation; three groups were irradiated with 0.3, 0.7 and 1 Gy (0.1 Gy/day) and the last subgroup with 1 Gy (0.2 Gy/day). All animals were sacrificed after three days of the last irradiation dose. The results revealed that all biochemical parameters were increased in rats exposed to fractionated doses more than the single doses. Hematological parameters were decreased in rats exposed to single doses more than the fractionated ones. In conclusion, the data of this study highlights the stimulatory effect of low ionizing radiation doses (= 1 Gy), whether single or fractionated, on some biochemical and immunological parameters

Analysis of radiation doses to patients from diagnostic department of nuclear medicine

Energy Technology Data Exchange (ETDEWEB)

Lepej, L; Messingerova, M [F.D. Rosvelt Hospital, Banska Bystrica (Slovakia). Dept. of Nuclear Medicine; Ftacnikova, S [Inst. of Preventive and Clinical Medicine, Bratislava (Slovakia)

1996-12-31

In this paper the values of mean effective dose equivalents per unit activity (H{sub E/1Bq}) were used for the calculation of mean effective dose equivalents for one examination (H{sub E}). The collective effective dose equivalents for each radiopharmaceutical and type of examination (S{sub ER}) and global collective effective dose equivalent for department for all radiopharmaceuticals (S{sub E}) during evaluated period were defined. The data for years from 1992 to 1994 were evaluated and compared with results in literature. The evaluation of radiation doses in nuclear medicine department is useful parameter for internal quality control. Using this method, the radiation dose in this laboratory was changed to minimum (under mean value of Slovak Republic). Unfortunately, the real data of patients radiation doses are different from the calculated one. Due to different kinetic of radiopharmaceuticals in individual patients (influenced by pathology, age, etc.) the evaluation of radiation burden to nuclear medicine patients is problematic. But this approach enable the relative comparison of the changes in values of H{sub E} and S{sub E} during the observed period. The evaluation of individual (minimal) effective dose equivalent - (H{sub min}) which represents dose calculated under physiologic conditions can be useful for indication of diagnostic examination by physicians. Therefore the systematic registration of H{sub min} from all examinations - patient`s radiation history. This is specially important in the case of children and young people. The importance of the proposed method, is in regulation of radiation dose from nuclear medicine diagnostic examinations, not only be the control of number and type of examinations, but also by selection of used radiopharmaceuticals and by the way how to use them. (J.K.) 1 fig., 2 refs.

Dose specification for radiation therapy: dose to water or dose to medium?

International Nuclear Information System (INIS)

Ma, C-M; Li Jinsheng

2011-01-01

The Monte Carlo method enables accurate dose calculation for radiation therapy treatment planning and has been implemented in some commercial treatment planning systems. Unlike conventional dose calculation algorithms that provide patient dose information in terms of dose to water with variable electron density, the Monte Carlo method calculates the energy deposition in different media and expresses dose to a medium. This paper discusses the differences in dose calculated using water with different electron densities and that calculated for different biological media and the clinical issues on dose specification including dose prescription and plan evaluation using dose to water and dose to medium. We will demonstrate that conventional photon dose calculation algorithms compute doses similar to those simulated by Monte Carlo using water with different electron densities, which are close (<4% differences) to doses to media but significantly different (up to 11%) from doses to water converted from doses to media following American Association of Physicists in Medicine (AAPM) Task Group 105 recommendations. Our results suggest that for consistency with previous radiation therapy experience Monte Carlo photon algorithms report dose to medium for radiotherapy dose prescription, treatment plan evaluation and treatment outcome analysis.

Dose-dependent hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to sublethal doses of gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Song, You, E-mail: you.song@niva.no [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway); Salbu, Brit; Teien, Hans-Christian; Heier, Lene Sørlie [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Rosseland, Bjørn Olav [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian University of Life Sciences (NMBU), Department of Ecology and Natural Resource Management, P.O. Box 5003, N-1432 Ås (Norway); Tollefsen, Knut Erik [Norwegian University of Life Sciences (NMBU), Faculty of Environmental Science and Technology, Department of Environmental Sciences (IMV), Centre for Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Ås (Norway); Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, N-0349 Oslo (Norway)

2014-11-15

affected DEGs associated with cellular signaling and immune response; 70 mGy radiation affected cell cycle regulation and DNA damage repair, cellular energy production; and 280 mGy radiation affected pathways related to cell cycle regulation and DNA repair, mitochondrial dysfunction and immune functions. Twelve genes representative of key pathways found in this study were verified by qPCR. Potential common MoAs of low-dose gamma radiation may include induction of oxidative stress, DNA damage and disturbance of oxidative phosphorylation (OXPHOS). Although common MoAs were proposed, a number of DEGs and pathways were still found to be dose-specific, potentially indicating multiple mechanisms of action (MOAs) of low-dose gamma radiation in fish. In addition, plasma glucose displayed an apparent increase with increasing radiation doses, although the results were not significantly different from the control. These findings suggested that sublethal doses of gamma radiation may cause dose-dependent transcriptional changes in the liver of Atlantic salmon after short-term exposure. The current study predicted multiple MoA for gamma radiation and may aid future impact assessment of environmental radioactivity in fish.

Compression force and radiation dose in the Norwegian Breast Cancer Screening Program

Energy Technology Data Exchange (ETDEWEB)

Waade, Gunvor G.; Sanderud, Audun [Department of Life Sciences and Health, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, P.O. 4 St. Olavs Plass, 0130 Oslo (Norway); Hofvind, Solveig, E-mail: solveig.hofvind@kreftregisteret.no [Department of Life Sciences and Health, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, P.O. 4 St. Olavs Plass, 0130 Oslo (Norway); The Cancer Registry of Norway, P.O. 5313 Majorstuen, 0304 Oslo (Norway)

2017-03-15

Highlights: • Compression force and radiation dose for 17 951 screening mammograms were analyzed. • Large variations in mean applied compression force between the breast centers. • Limited associations between compression force and radiation dose. - Abstract: Purpose: Compression force is used in mammography to reduce breast thickness and by that decrease radiation dose and improve image quality. There are no evidence-based recommendations regarding the optimal compression force. We analyzed compression force and radiation dose between screening centers in the Norwegian Breast Cancer Screening Program (NBCSP), as a first step towards establishing evidence-based recommendations for compression force. Materials and methods: The study included information from 17 951 randomly selected screening examinations among women screened with equipment from four different venors at fourteen breast centers in the NBCSP, January-March 2014. We analyzed the applied compression force and radiation dose used on craniocaudal (CC) and mediolateral-oblique (MLO) view on left breast, by breast centers and vendors. Results: Mean compression force used in the screening program was 116N (CC: 108N, MLO: 125N). The maximum difference in mean compression force between the centers was 63N for CC and 57N for MLO. Mean radiation dose for each image was 1.09 mGy (CC: 1.04mGy, MLO: 1.14mGy), varying from 0.55 mGy to 1.31 mGy between the centers. Compression force alone had a negligible impact on radiation dose (r{sup 2} = 0.8%, p = < 0.001). Conclusion: We observed substantial variations in mean compression forces between the breast centers. Breast characteristics and differences in automated exposure control between vendors might explain the low association between compression force and radiation dose. Further knowledge about different automated exposure controls and the impact of compression force on dose and image quality is needed to establish individualised and evidence

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

International Nuclear Information System (INIS)

1995-01-01

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

Occupational radiation doses during interventional procedures

International Nuclear Information System (INIS)

Nuraeni, N; Hiswara, E; Kartikasari, D; Waris, A; Haryanto, F

2016-01-01

Digital subtraction angiography (DSA) is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. The use of DSA procedures has been increased quite significantly in the Radiology departments in various cities in Indonesia. Various reports showed that both patients and medical staff received a noticeable radiation dose during the course of this procedure. A study had been carried out to measure these doses among interventionalist, nurse and radiographer. The results show that the interventionalist and the nurse, who stood quite close to the X-ray beams compared with the radiographer, received radiation higher than the others. The results also showed that the radiation dose received by medical staff were var depending upon the duration and their position against the X-ray beams. Compared tothe dose limits, however, the radiation dose received by all these three medical staff were still lower than the limits. (paper)

Radiation doses to the staff of a nuclear cardiology department

International Nuclear Information System (INIS)

Tsapaki, V.; Koutelou, M.; Theodorakos, A.; Kouzoumi, A.; Kitziri, S.; Tsiblouli, S.; Vardalaki, E.; Kyrozi, E.; Kouttou, S.

2002-01-01

The last years, new radiopharmaceuticals are used in a Nuclear Medicine (NM) Department. Nowadays, Single Photon Emission Computed Tomography (SPECT) is a method of routine imaging, a fact that has required increased levels of radioactivity in certain patient examinations. The staff that is more likely to receive the greatest radiation dose in a NM Department is the technologist who deals with performance of patient examination and injection of radioactive material and the nurse who is caring for the patients visiting the Department some of which being totally helpless. The fact that each NM Dept possesses equipment with certain specifications, deals with various kind of patients, has specific design and radiation protection measures which can differ from other NM Depts and uses various examination protocols, makes essential the need to investigate the radiation doses received by each member of the staff, so as to continuously monitor doses and take protective measures if required, control less experienced staff and ensure that radiation dose levels are kept as low as possible at all times. The purpose of the current study was to evaluate radiation dose to the nuclear cardiology department staff by thermoluminescent dosemeters (TLDs) placed on the the skin at thyroid and abdominal region as well as evaluating protection measures taken currently in the Dept

Radiation dose reduction in parasinus CT by spectral shaping

Energy Technology Data Exchange (ETDEWEB)

May, Matthias S.; Brand, Michael; Lell, Michael M.; Uder, Michael; Wuest, Wolfgang [University Hospital Erlangen, Department of Radiology, Erlangen (Germany); Sedlmair, Martin; Allmendinger, Thomas [Siemens Healthcare GmbH, Forchheim (Germany)

2017-02-15

Spectral shaping aims to narrow the X-ray spectrum of clinical CT. The aim of this study was to determine the image quality and the extent of radiation dose reduction that can be achieved by tin prefiltration for parasinus CT. All scans were performed with a third generation dual-source CT scanner. A study protocol was designed using 100 kV tube voltage with tin prefiltration (200 mAs) that provides image noise levels comparable to a low-dose reference protocol using 100 kV without spectral shaping (25 mAs). One hundred consecutive patients were prospectively enrolled and randomly assigned to the study or control group. All patients signed written informed consent. The study protocol was approved by the local Institutional Review Board and applies to the HIPAA. Subjective and objective image quality (attenuation values, image noise, and contrast-to-noise ratio (CNR)) were assessed. Radiation exposure was assessed as volumetric CT dose index, and effective dose was estimated. Mann-Whitney U test was performed for radiation exposure and for image noise comparison. All scans were of diagnostic image quality. Image noise in air, in the retrobulbar fat, and in the eye globe was comparable between both groups (all p > 0.05). CNR{sub eye} {sub globe/air} did not differ significantly between both groups (p = 0.7). Radiation exposure (1.7 vs. 2.1 mGy, p < 0.01) and effective dose (0.055 vs. 0.066 mSv, p < 0.01) were significantly reduced in the study group. Radiation dose can be further reduced by 17% for low-dose parasinus CT by tin prefiltration maintaining diagnostic image quality. (orig.)

Radiation dose reduction in parasinus CT by spectral shaping

International Nuclear Information System (INIS)

May, Matthias S.; Brand, Michael; Lell, Michael M.; Uder, Michael; Wuest, Wolfgang; Sedlmair, Martin; Allmendinger, Thomas

2017-01-01

Spectral shaping aims to narrow the X-ray spectrum of clinical CT. The aim of this study was to determine the image quality and the extent of radiation dose reduction that can be achieved by tin prefiltration for parasinus CT. All scans were performed with a third generation dual-source CT scanner. A study protocol was designed using 100 kV tube voltage with tin prefiltration (200 mAs) that provides image noise levels comparable to a low-dose reference protocol using 100 kV without spectral shaping (25 mAs). One hundred consecutive patients were prospectively enrolled and randomly assigned to the study or control group. All patients signed written informed consent. The study protocol was approved by the local Institutional Review Board and applies to the HIPAA. Subjective and objective image quality (attenuation values, image noise, and contrast-to-noise ratio (CNR)) were assessed. Radiation exposure was assessed as volumetric CT dose index, and effective dose was estimated. Mann-Whitney U test was performed for radiation exposure and for image noise comparison. All scans were of diagnostic image quality. Image noise in air, in the retrobulbar fat, and in the eye globe was comparable between both groups (all p > 0.05). CNR_e_y_e _g_l_o_b_e_/_a_i_r did not differ significantly between both groups (p = 0.7). Radiation exposure (1.7 vs. 2.1 mGy, p < 0.01) and effective dose (0.055 vs. 0.066 mSv, p < 0.01) were significantly reduced in the study group. Radiation dose can be further reduced by 17% for low-dose parasinus CT by tin prefiltration maintaining diagnostic image quality. (orig.)

Atmospheric radiation flight dose rates

Science.gov (United States)

Tobiska, W. K.

2015-12-01

Space weather's effects upon the near-Earth environment are due to dynamic changes in the energy transfer processes from the Sun's photons, particles, and fields. Of the domains that are affected by space weather, the coupling between the solar and galactic high-energy particles, the magnetosphere, and atmospheric regions can significantly affect humans and our technology as a result of radiation exposure. Space Environment Technologies (SET) has been conducting space weather observations of the atmospheric radiation environment at aviation altitudes that will eventually be transitioned into air traffic management operations. The Automated Radiation Measurements for Aerospace Safety (ARMAS) system and Upper-atmospheric Space and Earth Weather eXperiment (USEWX) both are providing dose rate measurements. Both activities are under the ARMAS goal of providing the "weather" of the radiation environment to improve aircraft crew and passenger safety. Over 5-dozen ARMAS and USEWX flights have successfully demonstrated the operation of a micro dosimeter on commercial aviation altitude aircraft that captures the real-time radiation environment resulting from Galactic Cosmic Rays and Solar Energetic Particles. The real-time radiation exposure is computed as an effective dose rate (body-averaged over the radiative-sensitive organs and tissues in units of microsieverts per hour); total ionizing dose is captured on the aircraft, downlinked in real-time, processed on the ground into effective dose rates, compared with NASA's Langley Research Center (LaRC) most recent Nowcast of Atmospheric Ionizing Radiation System (NAIRAS) global radiation climatology model runs, and then made available to end users via the web and smart phone apps. Flight altitudes now exceed 60,000 ft. and extend above commercial aviation altitudes into the stratosphere. In this presentation we describe recent ARMAS and USEWX results.

Low-Dose Radiation Cataract and Genetic Determinants of Radiosensitivity

Energy Technology Data Exchange (ETDEWEB)

Kleiman, Norman Jay [Columbia University

2013-11-30

The lens of the eye is one of the most radiosensitive tissues in the body. Ocular ionizing radiation exposure results in characteristic, dose related, progressive lens changes leading to cataract formation. While initial, early stages of lens opacification may not cause visual disability, the severity of such changes progressively increases with dose until vision is impaired and cataract extraction surgery may be required. Because of the transparency of the eye, radiation induced lens changes can easily be followed non-invasively over time. Thus, the lens provides a unique model system in which to study the effects of low dose ionizing radiation exposure in a complex, highly organized tissue. Despite this observation, considerable uncertainties remain surrounding the relationship between dose and risk of developing radiation cataract. For example, a growing number of human epidemiological findings suggest significant risk among various groups of occupationally and accidentally exposed individuals and confidence intervals that include zero dose. Nevertheless, questions remain concerning the relationship between lens opacities, visual disability, clinical cataract, threshold dose and/or the role of genetics in determining radiosensitivity. Experimentally, the response of the rodent eye to radiation is quite similar to that in humans and thus animal studies are well suited to examine the relationship between radiation exposure, genetic determinants of radiosensitivity and cataractogenesis. The current work has expanded our knowledge of the low-dose effects of X-irradiation or high-LET heavy ion exposure on timing and progression of radiation cataract and has provided new information on the genetic, molecular, biochemical and cell biological features which contribute to this pathology. Furthermore, findings have indicated that single and/or multiple haploinsufficiency for various genes involved in DNA repair and cell cycle checkpoint control, such as Atm, Brca1 or Rad9

Dose evaluation and protection of cosmic radiation

International Nuclear Information System (INIS)

Iwai, Satoshi; Takagi, Toshiharu

2004-01-01

This paper explained the effects of cosmic radiation on aircraft crews and astronauts, as well as related regulations. International Commission on Radiological Protection (ICRP) recommends the practice of radiation exposure management for the handling/storage of radon and materials containing natural radioactive substances, as well as for boarding jet aircraft and space flight. Common aircraft crew members are not subject to radiation exposure management in the USA and Japan. In the EU, the limit value is 6 mSv per year, and for the crew group exceeding this value, it is recommended to keep records containing appropriate medical examination results. Pregnant female crewmembers are required to keep an abdominal surface dose within 1 mSv. For astronauts, ICRP is in the stage of thinking about exposure management. In the USA, National Council on Radiation Protection and Measurement has set dose limits for 30 days, 1 year, and lifetime, and recommends lifetime effective dose limits against carcinogenic risk for each gender and age group. This is the setting of the dose limits so that the risk of carcinogenesis, to which space radiation exposure is considered to contribute, will reach 3%. For cosmic radiation environments at spacecraft inside and aircraft altitude, radiation doses can be calculated for astronauts and crew members, using the calculation methods for effective dose and dose equivalent for tissue. (A.O.)

Dosimetry control for radiation processing - basic requirements and standards

International Nuclear Information System (INIS)

Ivanova, M.; Tsrunchev, Ts.

2004-01-01

A brief review of the basic international codes and standards for dosimetry control for radiation processing (high doses dosimetry), setting up a dosimetry control for radiation processing and metrology control of the dosimetry system is made. The present state of dosimetry control for food processing and the Bulgarian long experience in food irradiation (three irradiation facilities are operational at these moment) are presented. The absence of neither national standard for high doses nor accredited laboratory for calibration and audit of radiation processing dosimetry systems is also discussed

Total dose and dose rate radiation characterization of EPI-CMOS radiation hardened memory and microprocessor devices

International Nuclear Information System (INIS)

Gingerich, B.L.; Hermsen, J.M.; Lee, J.C.; Schroeder, J.E.

1984-01-01

The process, circuit discription, and total dose radiation characteristics are presented for two second generation hardened 4K EPI-CMOS RAMs and a first generation 80C85 microprocessor. Total dose radiation performance is presented to 10M rad-Si and effects of biasing and operating conditions are discussed. The dose rate sensitivity of the 4K RAMs is also presented along with single event upset (SEU) test data

Standard Guide for Absorbed-Dose Mapping in Radiation Processing Facilities

CERN Document Server

American Society for Testing and Materials. Philadelphia

2003-01-01

1.1 This document provides guidance in determining absorbed-dose distributions in products, materials or substances irradiated in gamma, X-ray (bremsstrahlung) and electron beam facilities. Note 1—For irradiation of food and the radiation sterilization of health care products, other specific ISO and ISO/ASTM standards containing dose mapping requirements exist. For food irradiation, see ISO/ASTM 51204, Practice for Dosimetry in Gamma Irradiation Facilities for Food Processing and ISO/ASTM 51431, Practice for Dosimetry in Electron and Bremsstrahlung Irradiation Facilities for Food Processing. For the radiation sterilization of health care products, see ISO 11137: 1995, Sterilization of Health Care Products Requirements for Validation and Routine Control Radiation Sterilization. In those areas covered by ISO 11137, that standard takes precedence. ISO/ASTM Practice 51608, ISO/ASTM Practice 51649, and ISO/ASTM Practice 51702 also contain dose mapping requirements. 1.2 Methods of analyzing the dose map data ar...

Doses from Medical Radiation Sources

Science.gov (United States)

... Medical Radiation Sources Michael G. Stabin, PhD, CHP Introduction Radiation exposures from diagnostic medical examinations are generally ... of exposure annually to natural background radiation. Plain Film X Rays Single Radiographs Effective Dose, mSv Skull ( ...

A Paradigm Shift in Low Dose Radiation Biology

Directory of Open Access Journals (Sweden)

Z. Alatas

2015-08-01

Full Text Available When ionizing radiation traverses biological material, some energy depositions occur and ionize directly deoxyribonucleic acid (DNA molecules, the critical target. A classical paradigm in radiobiology is that the deposition of energy in the cell nucleus and the resulting damage to DNA are responsible for the detrimental biological effects of radiation. It is presumed that no radiation effect would be expected in cells that receive no direct radiation exposure through nucleus. The risks of exposure to low dose ionizing radiation are estimated by extrapolating from data obtained after exposure to high dose radiation. However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose radiation than they do to high dose radiation. Moreover, recent experimental evidences from many laboratories reveal the fact that radiation effects also occur in cells that were not exposed to radiation and in the progeny of irradiated cells at delayed times after radiation exposure where cells do not encounter direct DNA damage. Recently, the classical paradigm in radiobiology has been shifted from the nucleus, specifically the DNA, as the principal target for the biological effects of radiation to cells. The universality of target theory has been challenged by phenomena of radiation-induced genomic instability, bystander effect and adaptive response. The new radiation biology paradigm would cover both targeted and non-targeted effects of ionizing radiation. The mechanisms underlying these responses involve biochemical/molecular signals that respond to targeted and non-targeted events. These results brought in understanding that the biological response to low dose radiation at tissue or organism level is a complex process of integrated response of cellular targets as well as extra-cellular factors. Biological understanding of

Comparison and application study on cosmic radiation dose calculation received by air crew

International Nuclear Information System (INIS)

Zhou Qiang; Xu Cuihua; Ren Tianshan; Li Wenhong; Zhang Jing; Lu Xu

2009-01-01

Objective: To facilitate evaluation on Cosmic radiation dose received by flight crew by developing a convenient and effective measuring method. Methods: In comparison with several commonly used evaluating methods, this research employs CARI-6 software issued by FAA (Federal Aviation Administration) to measure Cosmic radiation dose for flight crew members exposed to. Results: Compared with other methods, CARI-6 is capable of providing reliable calculating results on radiation dose and applicable to all flight crew of different airlines. Conclusion: Cosmic radiation received by flight crew is on the list of occupational radiation. For a smooth running of Standards for controlling exposure to cosmic radiation of air crew, CARI software may be a widely applied tool in radiation close estimation of for flight crew. (authors)

Energies, health, medicine. Low radiation doses

International Nuclear Information System (INIS)

2004-01-01

This file concerns the biological radiation effects with a special mention for low radiation doses. The situation of knowledge in this area and the mechanisms of carcinogenesis are detailed, the different directions of researches are given. The radiation doses coming from medical examinations are given and compared with natural radioactivity. It constitutes a state of the situation on ionizing radiations, known effects, levels, natural radioactivity and the case of radon, medicine with diagnosis and radiotherapy. (N.C.)

Oligodendroglial response to ionizing radiation: Dose and dose-rate response

International Nuclear Information System (INIS)

Levy, R.P.

1991-12-01

An in vitro system using neuroglia from neonatal rat brain was developed to examine the morphologic, immunocytochemical and biochemical response of oligodendroglia to ionizing radiation. Following acute γ-irradiation at day-in-culture (DIC) 8, oligodendrocyte counts at DIC 14 were 55% to 65% of control values after 2 Gy, and 29% to 36% after 5 Gy. Counts increased to near-normal levels at DIC 21 in the 2 Gy group and to 75% of normal in the 5 Gy group. Myelin basic protein levels (MBP) at DIC 14 were 60% of control values after 2 Gy, and 40% after 5 Gy. At DIC 21, MBP after 2 Gy was 45% greater than that observed at DIC 14, but MBP, as a fraction of age-matched control values, dropped from 60% to 50%. Following 5 Gy, absolute MBP changed little between DIC 14 and DIC 21, but decreased from 40% to 25% of control cultures. The response to split-dose irradiation indicated that nearly all sublethal damage in the oligodendrocyte population (and its precursors) was repaired within 3 h to 4 h. A new compartmental cell model for radiation response in vitro of the oligodendrocyte population is proposed and examined in relation to the potential reaction to radiation injury in the brain

Oligodendroglial response to ionizing radiation: Dose and dose-rate response

Energy Technology Data Exchange (ETDEWEB)

Levy, Richard P. [Univ. of California, Berkeley, CA (United States)

1991-12-01

An in vitro system using neuroglia from neonatal rat brain was developed to examine the morphologic, immunocytochemical and biochemical response of oligodendroglia to ionizing radiation. Following acute γ-irradiation at day-in-culture (DIC) 8, oligodendrocyte counts at DIC 14 were 55% to 65% of control values after 2 Gy, and 29% to 36% after 5 Gy. Counts increased to near-normal levels at DIC 21 in the 2 Gy group and to 75% of normal in the 5 Gy group. Myelin basic protein levels (MBP) at DIC 14 were 60% of control values after 2 Gy, and 40% after 5 Gy. At DIC 21, MBP after 2 Gy was 45% greater than that observed at DIC 14, but MBP, as a fraction of age-matched control values, dropped from 60% to 50%. Following 5 Gy, absolute MBP changed little between DIC 14 and DIC 21, but decreased from 40% to 25% of control cultures. The response to split-dose irradiation indicated that nearly all sublethal damage in the oligodendrocyte population (and its precursors) was repaired within 3 h to 4 h. A new compartmental cell model for radiation response in vitro of the oligodendrocyte population is proposed and examined in relation to the potential reaction to radiation injury in the brain.

Oligodendroglial response to ionizing radiation: Dose and dose-rate response

Energy Technology Data Exchange (ETDEWEB)

Levy, R.P.

1991-12-01

An in vitro system using neuroglia from neonatal rat brain was developed to examine the morphologic, immunocytochemical and biochemical response of oligodendroglia to ionizing radiation. Following acute {gamma}-irradiation at day-in-culture (DIC) 8, oligodendrocyte counts at DIC 14 were 55% to 65% of control values after 2 Gy, and 29% to 36% after 5 Gy. Counts increased to near-normal levels at DIC 21 in the 2 Gy group and to 75% of normal in the 5 Gy group. Myelin basic protein levels (MBP) at DIC 14 were 60% of control values after 2 Gy, and 40% after 5 Gy. At DIC 21, MBP after 2 Gy was 45% greater than that observed at DIC 14, but MBP, as a fraction of age-matched control values, dropped from 60% to 50%. Following 5 Gy, absolute MBP changed little between DIC 14 and DIC 21, but decreased from 40% to 25% of control cultures. The response to split-dose irradiation indicated that nearly all sublethal damage in the oligodendrocyte population (and its precursors) was repaired within 3 h to 4 h. A new compartmental cell model for radiation response in vitro of the oligodendrocyte population is proposed and examined in relation to the potential reaction to radiation injury in the brain.

Effect of low-dose gamma-radiation upon hatchability and weight of chickens

International Nuclear Information System (INIS)

Vilic, M.; Kraljevic, P.; Simpraga, M.; Miljanic, S.

2006-01-01

Full text of publication follows: Although any dose of ionizing radiation has generally been recognized to be detrimental to living being, low dose ionizing radiation seems to invoke primary stimulative effects. Stimulatory effects of low dose ionizing radiation include many aspects such as growth, fecundity and longevity stimulation, accelerated development, enhance biological responses for immune systems, enzymatic repair, physiological functions, and the removal of cellular damage, including prevention and removal of cancers and other diseases. Low dose ionizing radiation might also cause changes in the concentration of some biochemical parameters in blood plasma of chickens such as changes in the concentration of total proteins, glucose and cholesterol. The objective of this study was to determine the effect of low doses of gamma irradiation before incubation and on the seventh day of incubation on hatchability of eggs and body weight of chickens. This study includes three independent experiments. In the first experiment, six-hundred eggs produced by a commercial flock of Avian-line 34, were irradiated by a dose of 0.15 Gy gamma radiation (60 Co) before incubation. In the second experiments also involving six-hundred-line 34 eggs were irradiated by dose of 0.15 Gy gamma radiation on the seventh day of incubation. In the third experiment three-hundred eggs produced by a commercial flock of Ross 308 were irradiated by dose 0.30 Gy gamma irradiation before incubation. Along with the chickens which were hatched from irradiated eggs, there was a control group of chickens hatched from nonirradiated eggs. All other conditions were the same for both groups. Hatchability was calculated in terms of all eggs divided with fertile eggs which hatched. The individual weights of the chickens were determined on the first and on the forty second day. Growth data were analyzed statistically by t-test. Irradiation of chicken eggs and embryos at rates o f 0.15 Gy increases

Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

International Nuclear Information System (INIS)

Morishima, Hiroshige; Koga, Taeko; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2000-01-01

As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

Dose measurement, its distribution and individual external dose assessments of inhabitants in the high background radiation areas in China

Energy Technology Data Exchange (ETDEWEB)

Morishima, Hiroshige; Koga, Taeko [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.; Tatsumi, Kusuo; Nakai, Sayaka; Sugahara, Tsutomu; Yuan Yongling; Wei Luxin

2000-10-01

As a part of the China-Japan cooperative research on natural radiation epidemiology, we have carried out a dose-assessment study to evaluate the external exposure to natural radiation in the high background radiation areas (HBRA) of Yangjiang in Guangdong province and in the control areas (CA) of Enping prefecture since 1991. Because of the difficulties in measuring the individual doses of all inhabitants directly by personal dosimeters, an indirect method was applied in which the exposed individual doses were estimated from the environmental radiation doses measured by survey meters and the occupancy factors of each hamlet. We analyzed the dose in the hamlets and the variation in the occupancy factors to obtain the parameters of dose estimation on the inhabitants in selected hamlets; Madi and several hamlets of different dose levels in HBRA and Hampizai hamlet in CA. With these parameters, we estimated individual dose rates and compared them with those obtained from direct measurement using dosimeters carried by selected individuals. The results obtained are as follows. The environmental radiation doses are influenced by the natural radioactive nuclide concentrations in building materials, the age of the building and the arrangement of the houses in a hamlet. There existed a fairly large and heterogeneous distribution of indoor and outdoor environmental radiations. The indoor radiation doses were due to exposure from the natural radioactive nuclides in the building materials and were about two times as large as the outdoor radiation doses. The difference between indoor and outdoor doses was not observed in CA. The occupancy factor was influenced by the age of individuals and by the season of the year. The occupancy factor was higher for infants and aged individuals than for other age groups. This lead to higher dose rates of exposure to those age groups. A good correlation was observed between the dose assessed indirectly and that measured directly and the

Ionizing radiation dose control for workers in a nuclear plant working with unsealed sources; Controle da dose de radiacao ionizante para trabalhadores em uma instalacao radiativa com fontes nao seladas

Energy Technology Data Exchange (ETDEWEB)

Gerulis, Eduardo

2006-07-01

With the liberation of the use of the nuclear energy for peaceful applications, International Commission Radiological Protection, ICRP, founded in 1928, created a system of protection of the undesirable doses of ionizing radiation in 1958. This has been received by workers, members of the public and environment and hence it became possible for the introduction of these applications. This protection system is adopted by the International Agency of Energy Atomic, IAEA, that publishes recommendations in safety series, 88 and by the Comissao Nacional de Energia Nuclear, CNEN, which publishes these regulations. The international recommendations and national regulations were adapted and they need to be applied in this way. The present paper uses recommendations of the publication 75 from ICRP, of the publication 115 from 88 and regulations of the regulation NN 3.01 from CNEN to present, through radiological protection measures, the ionizing radiation dose control for workers in a nuclear plant that works in the research, production, division and packing of unsealed sources to be used in clinical applications. In that way it is possible to prevent appropriately the undesirable doses and to confirm the received doses. (author)

Biological effects of low-dose ionizing radiation exposure; Biologische Wirkungen niedriger Dosen ionisierender Strahlung

Energy Technology Data Exchange (ETDEWEB)

Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst (comps.)

2009-07-01

The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

The principles of dose limitation in radiation protection

International Nuclear Information System (INIS)

Kaul, A.

1988-01-01

The aim of radiation protection is to protect individuals, their offspring and the population as a whole against harmful effects from ionizing radiation and radioactive substances. Harmful effects may be either somatic, i.e. occurring in the exposed person himself/herself, or hereditary, i.e. occurring in the exposed person's offspring. Successful radiation protection involves (a) protective measures based on the results of research into the biological and biophysical effects of radiation and (b) ensuring that activities necessitating exposure are justified and that the degree of exposure is minimal. This benefit/risk principle ceases to apply if a radiation source is out of control, since the main aim is then to introduce risk limitation measures, provided that these are of positive net benefit to the individual and the population as a whole. This paper discusses the principles of dose limitation as a function of exposure conditions, i.e. controlled or uncontrolled exposure to a source of radiation

Brachytherapy radiation doses to the neurovascular bundles

International Nuclear Information System (INIS)

Di Biase, Steven J.; Wallner, Kent; Tralins, Kevin; Sutlief, Steven

2000-01-01

Purpose: To investigate the role of radiation dose to the neurovascular bundles (NVB) in brachytherapy-related impotence. Methods and Materials: Fourteen Pd-103 or I-125 implant patients were studied. For patients treated with implant alone, the prostate and margin (clinical target volume [CTV]) received a prescription dose of 144 Gy for I-125 or 115 Gy for Pd-103. Two patients received Pd-103 (90 Gy) with 46 Gy supplemental external beam radiation (EBRT). Axial CT images were acquired 2 to 4 hours postoperatively for postimplant dosimetry. Because the NVBs cannot be visualized on CT, NVB calculation points were determined according to previously published anatomic descriptions. Bilateral NVB points were considered to lie posterior-laterally, approximately 2 mm from the prostatic capsule. NVB doses were recorded bilaterally, at 0.5-cm intervals from the prostatic base. Results: For Pd-103, the average NVB doses ranged from 150 Gy to 260 Gy, or 130% to 226% of the prescription dose. For I-125, the average NVB dose ranged from 200 Gy to 325 Gy, or 140% to 225% of the prescription dose. These was no consistent relationship between the NVB dose and the distance from the prostatic base. To examine the possible effect of minor deviations of our calculation points from the true NVB location, we performed NVB calculations at points 2 mm medial or lateral from the NVB calculation point in 8 patients. Doses at these alternate calculation points were comparable, although there was greater variability with small changes in the calculation point if sources were located outside the capsule, near the NVB calculation point. Three patients who developed early postimplant impotence had maximal NVB doses that far exceeded the average values. Conclusions: In the next few years, we hope to clarify the role of high NVB radiation doses on potency, by correlating NVB dose calculations with a large number of patients enrolled in an ongoing I-125 versus Pd-103 trial for early-stage patients

Radiation safety and control

International Nuclear Information System (INIS)

Kim, Jang Hee; Kim, Gi Sub.

1996-12-01

The principal objective of radiological safety control is intended for achievement and maintenance of appropriately safe condition in environmental control for activities involving exposure from the use of radiation. In order to establish these objective, we should be to prevent deterministic effects and to limit the occurrence stochastic effects to level deemed to be acceptable by the application of general principles of radiation protection and systems of dose limitation based on ICRP recommendations. (author). 22 tabs., 13 figs., 11 refs

Investigation of radiation skin dose in interventional cardiology

International Nuclear Information System (INIS)

Webster, C.M.; Horrocks, J.; Hayes, D.

2001-01-01

Background - The study investigated the radiation skin doses for interventional patients in cardiology; two procedures which have the highest radiation dose are Radiofrequency Catheter Ablation (RFCA) and Percutaneous Transluminal Coronary Angioplasty (PTCA). Methods and Results - 56 patients were randomly selected and investigated; 23 patients in the RFCA group and 33 in the PTCA group. Skin and effective dose were calculated from Dose Area Product (DAP). Thermoluminescent Dosimetry was the second method of dose measurement used. Patients were followed-up for a three month period to check for possible skin reactions resulting from the radiation dose during the procedure. Radiation skin doses in 14 patients were calculated to be more than 1 Gy, including three patients who received more than 2 Gy, the threshold dose for deterministic effects of radiation. 7 patients (12.5%) reported skin reactions as a result of the radiation received to their backs during the procedure. Mean DAP and estimated effective doses were 105 Gycm 2 and 22.5 mSv for RFCA, and 32 Gycm 2 and 6.2 mSv for PTCA procedures respectively. Conclusion - Complex procedures in Interventional Cardiology can exceed the threshold level for deterministic effects in the skin. (author)

Long distance elementary measurement of the radiation dose ratio produced by neutron activation

International Nuclear Information System (INIS)

Zhou Changgeng; Lou Benchao; Wu Chunlei; Hu Yonghong; Li Yan

2009-04-01

The working principle and the structure and performances of a long distance controllable individual radiation dose ratio instrument are described. The radiation dose ratio produced by neutron activation is elementarily measured by using this instrument in the neutron generator hall with high neutron yield. When neutron yield arrives to 2 x 10 11 s -1 , the radiation dose ratio produced by neutron activation is 99.9 μSv/h in 1 h after the generator being stopped. The radiation dose ratio is reduced to 24.4 μSv/h in 39 h after the generator being stopped. When neutron yield is 3.2 x 10 10 s -1 , the radiation dose ratio produced by neutron activation is 21.9 μSv/h in 36 min, after the generator being stopped. The measurement results may provide reference for physical experimenters and neutron generator operators. (authors)

Transatlantic Comparison of CT Radiation Doses in the Era of Radiation Dose-Tracking Software.

Science.gov (United States)

Parakh, Anushri; Euler, Andre; Szucs-Farkas, Zsolt; Schindera, Sebastian T

2017-12-01

The purpose of this study is to compare diagnostic reference levels from a local European CT dose registry, using radiation-tracking software from a large patient sample, with preexisting European and North American diagnostic reference levels. Data (n = 43,761 CT scans obtained over the course of 2 years) for the European local CT dose registry were obtained from eight CT scanners at six institutions. Means, medians, and interquartile ranges of volumetric CT dose index (CTDI vol ), dose-length product (DLP), size-specific dose estimate, and effective dose values for CT examinations of the head, paranasal sinuses, thorax, pulmonary angiogram, abdomen-pelvis, renal-colic, thorax-abdomen-pelvis, and thoracoabdominal angiogram were obtained using radiation-tracking software. Metrics from this registry were compared with diagnostic reference levels from Canada and California (published in 2015), the American College of Radiology (ACR) dose index registry (2015), and national diagnostic reference levels from local CT dose registries in Switzerland (2010), the United Kingdom (2011), and Portugal (2015). Our local registry had a lower 75th percentile CTDI vol for all protocols than did the individual internationally sourced data. Compared with our study, the ACR dose index registry had higher 75th percentile CTDI vol values by 55% for head, 240% for thorax, 28% for abdomen-pelvis, 42% for thorax-abdomen-pelvis, 128% for pulmonary angiogram, 138% for renal-colic, and 58% for paranasal sinus studies. Our local registry had lower diagnostic reference level values than did existing European and North American diagnostic reference levels. Automated radiation-tracking software could be used to establish and update existing diagnostic reference levels because they are capable of analyzing large datasets meaningfully.

Radiation Dose Measurement Using Chemical Dosimeters

International Nuclear Information System (INIS)

Lee, Min Sun; Kim, Eun Hee; Kim, Yu Ri; Han, Bum Soo

2010-01-01

The radiation dose can be estimated in various ways. Dose estimates can be obtained by either experiment or theoretical analysis. In experiments, radiation impact is assessed by measuring any change caused by energy deposition to the exposed matter, in terms of energy state (physical change), chemical production (chemical change) or biological abnormality (biological change). The chemical dosimetry is based on the implication that the energy deposited to the matter can be inferred from the consequential change in chemical production. The chemical dosimetry usually works on the sample that is an aqueous solution, a biological matter, or an organic substance. In this study, we estimated absorbed doses by quantitating chemical changes in matter caused by radiation exposure. Two different chemical dosimeters, Fricke and ECB (Ethanol-Chlorobenzene) dosimeter, were compared in several features including efficacy as dose indicator and effective dose range

Prenatal radiation exposure. Dose calculation

International Nuclear Information System (INIS)

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

2015-01-01

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

Influence of Flat-Panel Fluoroscopic Equipment Variables on Cardiac Radiation Doses

International Nuclear Information System (INIS)

Nickoloff, Edward L.; Lu Zhengfeng; Dutta, Ajoy; So, James; Balter, Stephen; Moses, Jeffrey

2007-01-01

Purpose. To assess the influence of physician-selectable equipment variables on the potential radiation dose reductions during cardiac catheterization examinations using modern imaging equipment. Materials. A modern bi-plane angiography unit with flat-panel image receptors was used. Patients were simulated with 15-30 cm of acrylic plastic. The variables studied were: patient thickness, fluoroscopy pulse rates, record mode frame rates, image receptor field-of-view (FoV), automatic dose control (ADC) mode, SID/SSD geometry setting, automatic collimation, automatic positioning, and others. Results. Patient radiation doses double for every additional 3.5-4.5 cm of soft tissue. The dose is directly related to the imaging frame rate; a decrease from 30 pps to 15 pps reduces the dose by about 50%. The dose is related to [(FoV) -N ] where 2.0 < N < 3.0. Suboptimal positioning of the patient can nearly double the dose. The ADC system provides three selections that can vary the radiation level by 50%. For pediatric studies (2-5 years old), the selection of equipment variables can result in entrance radiation doses that range between 6 and 60 cGy for diagnostic cases and between 15 and 140 cGy for interventional cases. For adult studies, the equipment variables can produce entrance radiation doses that range between 13 and 130 cGy for diagnostic cases and between 30 and 400 cGy for interventional cases. Conclusions. Overall dose reductions of 70-90% can be achieved with pediatric patients and about 90% with adult patients solely through optimal selection of equipment variables

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

International Nuclear Information System (INIS)

Ogata, Hiromitsu; Magae, Junji

2008-01-01

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

Application and inspiration of risk control in dose control in Fukushima nuclear accident

International Nuclear Information System (INIS)

Yu Shaoqing; Chen Yan; Chai Jianshe; Zhang Chunming

2013-01-01

The article introduced the basic concept of risk and risk control methods. Using the risk control methods, we analyzed and evaluated the actions to control dose of public and occupational radiation exposure in the Fukushima Dai-ichi nuclear power plant accident, especially found out the weak points of these actions, and finally discussed the application of the risk control methods in dose management during nuclear accidents. (authors)

Personal radiation monitoring and assessment of doses received by radiation workers (1991)

International Nuclear Information System (INIS)

Morris, N.D.

1992-06-01

The Australian Radiation Laboratory has operated a Personal Radiation Monitoring Service since the early 1930's so that people working with radiation can determine the radiation doses that they receive due to their occupation. Since late 1986, all persons monitored by the Service have been registered on a data base which maintains records of the doses received by each individual wearer. Ultimately, this data base will become a National Register of the doses received within Australia. At present, the Service regularly monitors approximately 20,000 persons, which is roughly 70 percent of those monitored in Australia, and maintains dose histories of over 35,000 people. The skin dose for occupationally exposed workers can be measured by using one of the four types of monitor issued by the Service: 1. Thermoluminescent Dosemeter (TLD monitor) 2. Finger TLD 3. Neutron Monitor 4. Special TLD. The technical description of the monitors is provided along with the method for calculating the radiation dose. 5 refs., 7 tabs., 4 figs

Radiation dose to the patient in radionuclide studies

International Nuclear Information System (INIS)

Roedler, H.D.

1981-01-01

In medical radionuclide studies, the radiation risk has to be considered in addition to the general risk of administering a pharmaceutical. As radiation exposure is an essential factor in radiation risk estimation, some aspects of internal dose calculation, including radiation risk assessments, are treated. The formalism of current internal dose calculation is presented. The input data, especially the residence time and the absorbed dose per transformation, their origin and accuracy are discussed. Results of internal dose calculations for the ten most frequently used radionuclide studies are presented as somatically effective dose equivalents. The accuracy of internal dose calculation is treated in detail by considering the biokinetics of the radiopharmaceutical, the phantoms used for dose calculations, the absorbed dose per transformation, the administered activity, and the transfer of the dose, calculated for a phantom, to the patient. The internal dose calculated for a reference phantom may be assumed to be in accordance with the actual patient dose within a range described by a factor of about two to three. Finally, risk estimates for nuclear medicine procedures are quantified, being generally of sixth order. The radiation risk from the radioiodine test is comparably higher, but probably lower than calculated according to the UNSCEAR risk coefficients. However, further studies are needed to confirm these preliminary results and to improve the quantification of the radiation risk from the medical use of radionuclides. (author)

Estimates of radiation doses from various sources of exposure

International Nuclear Information System (INIS)

Anon.

1992-01-01

This chapter provides an overview of radiation doses to individuals and to the collective US population from various sources of ionizing radiation. Summary tables present doses from various sources of ionizing radiation. Summary tables present doses from occupational exposures and annual per capita doses from natural background, the healing arts, nuclear weapons, nuclear energy and consumer products. Although doses from non-ionizing radiation are not as yet readily available in a concise form, the major sources of non-ionizing radiation are listed

Radiation dose to technologists per nuclear medicine examination and estimation of annual dose.

Science.gov (United States)

Bayram, Tuncay; Yilmaz, A Hakan; Demir, Mustafa; Sonmez, Bircan

2011-03-01

Conventional diagnostic nuclear medicine applications have been continuously increasing in most nuclear medicine departments in Turkey, but to our knowledge no one has studied the doses to technologists who perform nuclear medicine procedures. Most nuclear medicine laboratories do not have separate control rooms for technologists, who are quite close to the patient during data acquisition. Technologists must therefore stay behind lead shields while performing their task if they are to reduce the radiation dose received. The aim of this study was to determine external radiation doses to technologists during nuclear medicine procedures with and without a lead shield. Another aim was to investigate the occupational annual external radiation doses to Turkish technologists. This study used a Geiger-Müller detector to measure dose rates to technologists at various distances from patients (0.25, 0.50, 1, and 2 m and behind a lead shield) and determined the average time spent by technologists at these distances. Deep-dose equivalents to technologists were obtained. The following conventional nuclear medicine procedures were considered: thyroid scintigraphy performed using (99m)Tc pertechnetate, whole-body bone scanning performed using (99m)Tc-methylene diphosphonate, myocardial perfusion scanning performed using (99m)Tc-methoxyisobutyl isonitrile, and (201)Tl (thallous chloride) and renal scanning performed using (99m)Tc-dimercaptosuccinic acid. The measured deep-dose equivalent to technologists per procedure was within the range of 0.13 ± 0.05 to 0.43 ± 0.17 μSv using a lead shield and 0.21 ± 0.07 to 1.01 ± 0.46 μSv without a lead shield. Also, the annual individual dose to a technologist performing only a particular scintigraphic procedure throughout a year was estimated. For a total of 95 clinical cases (71 patients), effective external radiation doses to technologists were found to be within the permissible levels. This study showed that a 2-mm lead shield

Effects of low dose gamma radiation on the early growth of red pepper and the resistance to subsquent high dose of radiation

Energy Technology Data Exchange (ETDEWEB)

Kim, J. S.; Baek, M. H.; Kim, D. H.; Lee, Y. K. [KAERI, Taejon (Korea, Republic of); Lee, Y. B. [Chungnam National Univ., Taejon (Korea, Republic of)

2001-05-01

Red pepper (capsicum annuum L. cv. Jokwang and cv. Johong) seeds were irradiated with the dose of 0{approx}50 Gy to investigated the effect of the low dose gamma radiation on the early growth and resistance to subsequent high dose of radiation. The effect of the low dose gamma radiation on the early growth and resistance to subsequenct high dose of radiation were enhanced in Johong cultivar but not in Jokwang cultivar. Germination rate and early growth of Johong cultivar were noticeably increased at 4 Gy-, 8 Gy- and 20 Gy irradiation group. Resistance to subsequent high dose of radiation of Johong cultivar were increased at almost all of the low dose irradiation group. Especially it was highest at 4 Gy irradiation group. The carotenoid contents and enzyme activity on the resistance to subsequent high dose of radiation of Johong cultivar were increased at the 4 Gy and 8 Gy irradiation group.

Cosmic radiation dose in the aircraft

International Nuclear Information System (INIS)

Vukovic, B.; Radolic, V.; Varga, M.; Planinic, J.; Vekic, B.

2006-01-01

When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A 320 and ATR 42 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or 10B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb - Paris - Buenos Aires and reversely, when one measured cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 μSv/h and the TLD dosimeter registered the total dose of 75 μSv or the average dose rate of 2.7 μSv/h; the neutron dosimeter gave the dose rate of 2.4 μSv/h. In the same month, February 2005, a traveling to the Japan (24 hours-flight: Zagreb - Frankfurt - Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 μSv/h; the neutron dosimeter gave the dose rate of 2.5 μSv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude the neutron component curried about 50% of the total dose, that was near other known data. (author)

Fiber optics in high dose radiation fields

International Nuclear Information System (INIS)

Partin, J.K.

1985-01-01

A review of the behavior of state-of-the-art optical fiber waveguides in high dose (greater than or equal to 10 5 rad), steady state radiation fields is presented. The influence on radiation-induced transmission loss due to experimental parameters such as dose rate, total dose, irradiation history, temperature, wavelength, and light intensity, for future work in high dose environments are given

Radiation dose assessment in nuclear medicine

International Nuclear Information System (INIS)

Stabin, M.G.

2002-01-01

In any application involving the use of ionizing radiation in humans, risks and benefits must be properly evaluated and balanced. Radionuclides are used in nuclear medicine in a variety of diagnostic and therapeutic procedures. Recently, interest has grown in therapeutic agents for a number of applications in nuclear medicine, particularly in the treatment of hematologic and non-hematologic malignancies. This has heightened interest in the need for radiation dose calculations and challenged the scientific community to develop more patient-specific and relevant dose models. Consideration of radiation dose in such studies is central to efforts to maximize dose to tumor while sparing normal tissues. In many applications, a significant absorbed dose may be received by some radiosensitive organs, particularly the active marrow. This talk will review the methods and models used in internal dosimetry in nuclear medicine, and discuss some current trends and challenges in this field

Calculation of the dose caused by internal radiation

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

For the purposes of monitoring radiation exposure it is necessary to determine or to estimate the dose caused by both external and internal radiation. When comparing the value of exposure to the dose limits, account must be taken of the total dose incurred from different sources. This guide explains how to calculate the committed effective dose caused by internal radiation and gives the conversion factors required for the calculation. Application of the maximum values for radiation exposure is dealt with in ST guide 7.2, which also sets out the definitions of the quantities and concepts most commonly used in the monitoring of radiation exposure. The monitoring of exposure and recording of doses are dealt with in ST Guides 7.1 and 7.4.

Dose Response Model of Biological Reaction to Low Dose Rate Gamma Radiation

International Nuclear Information System (INIS)

Magae, J.; Furikawa, C.; Hoshi, Y.; Kawakami, Y.; Ogata, H.

2004-01-01

It is necessary to use reproducible and stable indicators to evaluate biological responses to long term irradiation at low dose-rate. They should be simple and quantitative enough to produce the results statistically accurate, because we have to analyze the subtle changes of biological responses around background level at low dose. For these purposes we chose micronucleus formation of U2OS, a human osteosarcoma cell line, as indicators of biological responses. Cells were exposed to gamma ray in irradiation rom bearing 50,000 Ci 60Co. After irradiation, they were cultured for 24 h in the presence of cytochalasin B to block cytokinesis, and cytoplasm and nucleus were stained with DAPI and prospidium iodide, respectively. the number of binuclear cells bearing micronuclei was counted under a fluorescence microscope. Dose rate in the irradiation room was measured with PLD. Dose response of PLD is linear between 1 mGy to 10 Gy, and standard deviation of triplicate count was several percent of mean value. We fitted statistically dose response curves to the data, and they were plotted on the coordinate of linearly scale response and dose. The results followed to the straight line passing through the origin of the coordinate axes between 0.1-5 Gy, and dose and does rate effectiveness factor (DDREF) was less than 2 when cells were irradiated for 1-10 min. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose above 0.1 Gy when 5,000 binuclear cells were analyzed. In contrast, dose response curves never followed LNT, when cells were irradiated for 7 to 124 days. Difference of the percent binuclear cells bearing micronucleus between irradiated cells and control cells was not statistically significant at the dose below 6 Gy, when cells were continuously irradiated for 124 days. These results suggest that dose response curve of biological reaction is remarkably affected by exposure

Measurement of local dose rates in controlled areas of nuclear power plants. Version 6/85

International Nuclear Information System (INIS)

1985-01-01

Local dose rate measurements according to this regulation, serve the following purposes: Development of preventive measures for radiation protection with respect to maintenance and modifications in controlled areas, e.g. determination of individual measures for personnel protection, development of flow charts and dose rate estimates; monitoring of the personnel's location of activity within the controlled area, including determination of time-dependence of local dose rates and determination of immediate radiation protection measures required; limitation and identification of controlled areas. Such measurements are performed to ensure that the principles of radiation protection as stated in Art. 28 (1) of the Radiation Protection Ordinance with respect to external radiation exposure of the personnel, and the requirements of Art. 61 (1) of the Radiation Protection Ordinance relating to controlled areas are met and the limitation and identification of controlled areas as prescribed in Art 57 (1) of the Radiation Protection Ordinance can be performed. They are not used to determine body doses as per Art. 63 of the Radiation Protection Ordinance. (orig./HP) [de

Measuring radiation dose to patients undergoing fluoroscopically-guided interventions

International Nuclear Information System (INIS)

Lubis, L E; Badawy, M K

2016-01-01

The increasing prevalence and complexity of fluoroscopically guided interventions (FGI) raises concern regarding radiation dose to patients subjected to the procedure. Despite current evidence showing the risk to patients from the deterministic effects of radiation (e.g. skin burns), radiation induced injuries remain commonplace. This review aims to increase the awareness surrounding radiation dose measurement for patients undergoing FGI. A review of the literature was conducted alongside previous researches from the authors’ department. Studies pertaining to patient dose measurement, its formalism along with current advances and present challenges were reviewed. Current patient monitoring techniques (using available radiation dosimeters), as well as the inadequacy of accepting displayed dose as patient radiation dose is discussed. Furthermore, advances in real-time patient radiation dose estimation during FGI are considered. Patient dosimetry in FGI, particularly in real time, remains an ongoing challenge. The increasing occurrence and sophistication of these procedures calls for further advances in the field of patient radiation dose monitoring. Improved measuring techniques will aid clinicians in better predicting and managing radiation induced injury following FGI, thus improving patient care. (paper)

Remote Sensing of Radiation Dose Rate by Customizing an Autonomous Robot

International Nuclear Information System (INIS)

Kobayashi, T; Nakahara, M; Morisato, K; Takashina, T; Kanematsu, H

2012-01-01

Distribution of radiation dose was measured by customizing an autonomous cleaning robot 'Roomba' and a scintillation counter. The robot was used as a vehicle carrying the scintillation survey meter, and was additionally equipped with an H8 micro computer to remote-control the vehicle and to send measured data. The data obtained were arranged with position data, and then the distribution map of the radiation dose rate was produced. Manual, programmed and autonomous driving tests were conducted, and all performances were verified. That is, for each operational mode, the measurements both with moving and with discrete moving were tried in and outside of a room. Consequently, it has been confirmed that remote sensing of radiation dose rate is possible by customizing a robot on market.

Calculating radiation exposure and dose

International Nuclear Information System (INIS)

Hondros, J.

1987-01-01

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

Radiation dose to the global flying population

International Nuclear Information System (INIS)

Alvarez, Luis E; Eastham, Sebastian D; Barrett, Steven R H

2016-01-01

Civil airliner passengers and crew are exposed to elevated levels of radiation relative to being at sea level. Previous studies have assessed the radiation dose received in particular cases or for cohort studies. Here we present the first estimate of the total radiation dose received by the worldwide civilian flying population. We simulated flights globally from 2000 to 2013 using schedule data, applying a radiation propagation code to estimate the dose associated with each flight. Passengers flying in Europe and North America exceed the International Commission on Radiological Protection annual dose limits at an annual average of 510 or 420 flight hours per year, respectively. However, this falls to 160 or 120 h on specific routes under maximum exposure conditions. (paper)

Radiation Dose to Post-Chernobyl Cleanup Workers

Science.gov (United States)

Radiation dose calculation for post-Chernobyl Cleanup Workers in Ukraine - both external radiation exposure due to fallout and internal doses due to inhalation (I131 intake) or ingestion of contaminated foodstuffs.

A mathematical foundation for controlling radiation health risks

International Nuclear Information System (INIS)

Kumazawa, S.

2000-01-01

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

Risk equivalent of exposure versus dose of radiation

International Nuclear Information System (INIS)

Bond, V.P.

1986-01-01

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

Radiation dose registration and epidemiological study for workers of nuclear institutions in Japan

International Nuclear Information System (INIS)

Kumatori, T.

1992-01-01

The first nuclear reactor was operated in 1957 at Tokai-mura in Japan. Since then radiation dose of workers has been controlled by nuclear institutions according to the Law for the Regulations of Nuclear Source Material, Nuclear Fuel Material and Reactors. However, many nuclear power plants and other nuclear facilities were built, resulting in the remarkable increase of workers in controlled areas. Further, periodical inspection and repair work at nuclear facilities were carried out by employees of subcontractors, who were engaged in such work at many different facilities, so that it was getting more and more difficult to obtain accurate information of radiation dose on these workers. In order to meet this situation, the open-quotes Radiation Dose Registration Center for Workersclose quotes (RADREC) was established in November 1977 within the open-quotes Radiation Effects Associationclose quotes (REA), which was founded in September 1960 for the purpose of supporting the research on radiation effects and radiation protection. In January 1978, RADREC was designated by the Government as an organization to preserve the records on exposure of radiation workers, which was linked up with the registration system

Should we routinely remove the dose delivered by the images of control?; Faut-il systematiquement retirer la dose delivree par les images de controle?

Energy Technology Data Exchange (ETDEWEB)

Goasduff, G. [Centre Hospitalier Universitaire Morvan, Service de Radiotherapie, 29 - Brest (France); Pene Baverez, D.; Pradier, O.; Bouchekoua, M. [Service de Radiotherapie, 29 - Brest (France)

2009-10-15

The constraints of doses fixed by the international commission on radiation units and measurements (ICRU) for the target volume (95-107% of the prescribed dose) are respected. for the hypo fractionated treatments, it is necessary to control the impact of the dose delivered by the control images for every patient. The dose delivered at the isocenter is estimated between 1 and 3 Gy by control image: this dose depends on the beams size and on the distance-source-skin. Protocols of the patient positioning checking must be implemented on optimizing their frequency to limit the dose received by the patient. (N.C.)

Occupational radiation exposure to low doses of ionizing radiation and female breast cancer

International Nuclear Information System (INIS)

Adelina, P.; Bliznakov, V.; Bairacova, A.

2003-01-01

The aim of this study is to examine the relationship between past occupational radiation exposure to low doses of ionizing radiation and cases of diagnosed and registered breast cancer [probability of causation - PC] among Bulgarian women who have used different ionizing radiation sources during their working experience. The National Institute of Health (NIH) in US has developed a method for estimating the probability of causation (PC) between past occupational radiation exposure to low doses of ionizing radiation and cases of diagnosed cancer. We have used this method. A group of 27 women with diagnosed breast cancer has been studied. 11 of them are former workers in NPP - 'Kozloduy', and 16 are from other sites using different sources of ionizing radiation. Analysis was performed for 14 women, for whom full personal data were available. The individual radiation dose for each of them is below 1/10 of the annual dose limit, and the highest cumulative dose for a period of 14 years of occupational exposure is 50,21 mSv. The probability of causation (PC) values in all analyzed cases are below 1%, which confirms the extremely low probability of causation (PC) between past occupational radiation exposure to low doses of ionizing radiation and occurring cases of breast cancer. (orig.)

Radiation-resistant control system

International Nuclear Information System (INIS)

Cable, T.C.; Jones, S.

1995-01-01

REMOTEC has developed a open-quotes radiation resistanceclose quotes control system under a U.S. Department of Energy Small Business Innovative Research (SBIR) contract with assistance from the University of Florida. The SBIR goal was to develop a radiation resistant mobile robot from the ANDROS family of hazardous duty mobile robots that REMOTEC manufactures. See Refs. 1 and 2 for additional SBIR results. The control system, as well as the entire ANDROS robot, was redesigned, where necessary, to withstand radiation doses in excess of 10 6 rad. Those components of the robot that could not be purchased as open-quotes radiation hardenedclose quotes were tested under standard operating conditions for determination of their open-quotes radiation resistance.close quotes The entire ANDROS robot was then assembled with these new components and tested to > 10 6 rad

Estimation of radiation risks at low dose

International Nuclear Information System (INIS)

1990-04-01

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

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

International Nuclear Information System (INIS)

1975-05-01

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

Occupational radiation doses among diagnostic radiation workers in South Korea, 1996-2006

International Nuclear Information System (INIS)

Lee, W. J.; Cha, E. S.; Ha, M.; Jin, Y. W.; Hwang, S. S.; Kong, K. A.; Lee, S. W.; Lee, H. K.; Lee, K. Y.; Kim, H. J.

2009-01-01

This study details the distribution and trends of doses of occupational radiation among diagnostic radiation workers by using the national dose registry between 1996 and 2006 by the Korea Food and Drug Administration. Dose measurements were collected quarterly by the use of thermoluminescent dosemeter personal monitors. A total of 61 732 workers were monitored, including 18 376 radiologic technologists (30%), 13 762 physicians (22%), 9858 dentists (16%) and 6114 dental hygienists (9.9%). The average annual effective doses of all monitored workers decreased from 1.75 to 0.80 mSv over the study period. Among all diagnostic radiation workers, radiologic technologists received both the highest effective and collective doses. Male radiologic technologists aged 30-49 y composed the majority of workers receiving more than 5 mSv in a quarter. More intensive monitoring of occupational radiation exposure and investigation into its health effects on diagnostic radiation workers are required in South Korea. (authors)

Exposure to Low-Dose X-Ray Radiation Alters Bone Progenitor Cells and Bone Microarchitecture.

Science.gov (United States)

Lima, Florence; Swift, Joshua M; Greene, Elisabeth S; Allen, Matthew R; Cunningham, David A; Braby, Leslie A; Bloomfield, Susan A

2017-10-01

Exposure to high-dose ionizing radiation during medical treatment exerts well-documented deleterious effects on bone health, reducing bone density and contributing to bone growth retardation in young patients and spontaneous fracture in postmenopausal women. However, the majority of human radiation exposures occur in a much lower dose range than that used in the radiation oncology clinic. Furthermore, very few studies have examined the effects of low-dose ionizing radiation on bone integrity and results have been inconsistent. In this study, mice were irradiated with a total-body dose of 0.17, 0.5 or 1 Gy to quantify the early (day 3 postirradiation) and delayed (day 21 postirradiation) effects of radiation on bone microarchitecture and bone marrow stromal cells (BMSCs). Female BALBc mice (4 months old) were divided into four groups: irradiated (0.17, 0.5 and 1 Gy) and sham-irradiated controls (0 Gy). Micro-computed tomography analysis of distal femur trabecular bone from animals at day 21 after exposure to 1 Gy of X-ray radiation revealed a 21% smaller bone volume (BV/TV), 22% decrease in trabecular numbers (Tb.N) and 9% greater trabecular separation (Tb.Sp) compared to sham-irradiated controls (P X-rays, whereas osteoclastogenesis was enhanced. A better understanding of the effects of radiation on osteoprogenitor cell populations could lead to more effective therapeutic interventions that protect bone integrity for individuals exposed to low-dose ionizing radiation.

Biological effects of low doses of radiation at low dose rate

International Nuclear Information System (INIS)

1996-05-01

The purpose of this report was to examine available scientific data and models relevant to the hypothesis that induction of genetic changes and cancers by low doses of ionizing radiation at low dose rate is a stochastic process with no threshold or apparent threshold. Assessment of the effects of higher doses of radiation is based on a wealth of data from both humans and other organisms. 234 refs., 26 figs., 14 tabs

Radiation oncology: what can we achieve by optimized dose delivery?

International Nuclear Information System (INIS)

Lawrence, T.

2003-01-01

Spectacular technical advances have marked the last twenty years in radiation oncology. This revolution began with CT-based planning which was followed by 3D conformal therapy. The latter approach produced two important capabilities. The most obvious was that tumors could be viewed in their true location with respect to normal tissues and treated with beams that were not in the axial plane. A second equally important advance was the development of 3D planning tools such as dose volume histograms. These tools permitted quantitative comparison of treatment plans and have supported the development of models relating normal tissue irradiation to the risk of complication. The '3D hypothesis' - that 3D treatment planning would permit higher doses of radiation to be safely delivered-has been proven. Dose escalation studies have been successfully conducted in the lung (= 100 Gy), liver (= 90 Gy), brain (= 90 Gy), and prostate (= 78 Gy). Prospective phase II and phase III trials suggest improved outcome using these higher doses for tumors in the liver and prostate compared to doses considered acceptable in the 2D era. The next technical revolution is underway, with advances in '4D' radiotherapy (accounting fully for organ motion) and in intensity-modulated radiation therapy (IMRT) to further improve the conformality and accuracy of treatment. Proton therapy will improve dose distributions still further. These improved dose distributions can be combined with more accurate tumor delineation provided by functional imaging to offer the potential for additional dose escalation without toxicity and for improved tumor control. These developments permit us to ask if we are approaching the limits of dose optimization and how (if?) research in radiation delivery should proceed

Dose distribution following selective internal radiation therapy

International Nuclear Information System (INIS)

Fox, R.A.; Klemp, P.F.; Egan, G.; Mina, L.L.; Burton, M.A.; Gray, B.N.

1991-01-01

Selective Internal Radiation Therapy is the intrahepatic arterial injection of microspheres labelled with 90Y. The microspheres lodge in the precapillary circulation of tumor resulting in internal radiation therapy. The activity of the 90Y injected is managed by successive administrations of labelled microspheres and after each injection probing the liver with a calibrated beta probe to assess the dose to the superficial layers of normal tissue. Predicted doses of 75 Gy have been delivered without subsequent evidence of radiation damage to normal cells. This contrasts with the complications resulting from doses in excess of 30 Gy delivered from external beam radiotherapy. Detailed analysis of microsphere distribution in a cubic centimeter of normal liver and the calculation of dose to a 3-dimensional fine grid has shown that the radiation distribution created by the finite size and distribution of the microspheres results in an highly heterogeneous dose pattern. It has been shown that a third of normal liver will receive less than 33.7% of the dose predicted by assuming an homogeneous distribution of 90Y

Trends in doses to some UK radiation workers

International Nuclear Information System (INIS)

Best, R.J.; Kendall, G.M.; Pook, E.A.; Saunders, P.J.

1990-01-01

The NRPB runs a Personal Monitoring Service which issues dosemeters and keeps radiation dose records for over 10 000 workers. This database is a valuable source of information on occupational exposure to radiation though it is likely that in future the Central Index of Dose Information (CIDI) will provide more comprehensive statistics, albeit restricted to radiation workers in the sense of Ionising Radiation Regulations. This note describes doses incurred to the end of 1987 with some preliminary figures for 1988. It does not cover the same ground as earlier reports but gives more details of the structure of the monitored population by age and sex and examines evidence that mean radiation doses are decreasing with time. (author)

Controllable dose: the ICRP discussion paper does not go far enough

International Nuclear Information System (INIS)

Carter, M.W.

2000-01-01

The current ICRP recommendations and the associated dosimetry have confused the public, lawyers and politicians and have been the subject of dissension within the Health Physics Community. Currently recommended limits are different for occupational exposure, exposure of the public, exposure to radon in dwellings and exposure to radon in workplaces. Current recommendations do not cover exposure in accident situations. The recommended limits do not apply to natural background radiation exposures. This suggests that the unit of radiation dose is variable depending on the circumstances and that artificially produced radiation is more harmful than natural radiation. The use of collective dose and the LNT model has resulted, in the opinion of some, in waste of money spent in trying to reduce doses that may be already too small to produce detectable harm. The recent discussion papers (Clarke, 1998, Clarke 1999), introducing the concept of controllable dose, are a valuable starting point for changing and improving the basis on which regulations are made. It is the author's opinion that the discussion paper does not go far enough and that the confusion is largely the result of failing to separate the scientific aspects from the regulatory aspects of controlling radiation dose. Only by making such a separation can we provide understandable regulations without compromising scientific research into radiation risks. Copyright (2000) Australasian Radiation Protection Society Inc

Radiation dose associated with CT-guided drain placement for pediatric patients

Energy Technology Data Exchange (ETDEWEB)

Schwartz, Cody J.; Isaacson, Ari J.; Fordham, Lynn Ansley; Ivanovic, Marija; Dixon, Robert G. [University of North Carolina at Chapel Hill, Department of Radiology, UNC Health Care, Chapel Hill, NC (United States); Taylor, J.B. [University of North Carolina at Chapel Hill, Environment, Health and Safety, Chapel Hill, NC (United States)

2017-05-15

To date, there are limited radiation dose data on CT-guided procedures in pediatric patients. Our goal was to quantify the radiation dose associated with pediatric CT-guided drain placement and follow-up drain evaluations in order to estimate effective dose. We searched the electronic medical record and picture archiving and communication system (PACS) to identify all pediatric (<18 years old) CT-guided drain placements performed between January 2008 and December 2013 at our institution. We compiled patient data and radiation dose information from CT-guided drain placements as well as pre-procedural diagnostic CTs and post-procedural follow-up fluoroscopic abscess catheter injections (sinograms). Then we converted dose-length product, fluoroscopy time and number of acquisitions to effective doses using Monte Carlo simulations and age-appropriate conversion factors based on annual quality-control testing. Fifty-two drainages were identified with mean patient age of 11.0 years (5 weeks to 17 years). Most children had diagnoses of appendicitis (n=23) or inflammatory bowel disease (n=11). Forty-seven patients had diagnostic CTs, with a mean effective dose of 7.3 mSv (range 1.1-25.5 mSv). Drains remained in place for an average of 16.9 days (range 0-75 days), with an average of 0.9 (0-5) sinograms per patient in follow-up. The mean effective dose for all drainages and follow-up exams was 5.3 mSv (0.7-17.1) and 62% (32/52) of the children had effective doses less than 5 mSv. The majority of pediatric patients who have undergone CT-guided drain placements at our institution have received total radiation doses on par with diagnostic ranges. This information could be useful when describing the dose of radiation to parents and providers when CT-guided drain placement is necessary. (orig.)

Radiation dose associated with CT-guided drain placement for pediatric patients

International Nuclear Information System (INIS)

Schwartz, Cody J.; Isaacson, Ari J.; Fordham, Lynn Ansley; Ivanovic, Marija; Dixon, Robert G.; Taylor, J.B.

2017-01-01

To date, there are limited radiation dose data on CT-guided procedures in pediatric patients. Our goal was to quantify the radiation dose associated with pediatric CT-guided drain placement and follow-up drain evaluations in order to estimate effective dose. We searched the electronic medical record and picture archiving and communication system (PACS) to identify all pediatric (<18 years old) CT-guided drain placements performed between January 2008 and December 2013 at our institution. We compiled patient data and radiation dose information from CT-guided drain placements as well as pre-procedural diagnostic CTs and post-procedural follow-up fluoroscopic abscess catheter injections (sinograms). Then we converted dose-length product, fluoroscopy time and number of acquisitions to effective doses using Monte Carlo simulations and age-appropriate conversion factors based on annual quality-control testing. Fifty-two drainages were identified with mean patient age of 11.0 years (5 weeks to 17 years). Most children had diagnoses of appendicitis (n=23) or inflammatory bowel disease (n=11). Forty-seven patients had diagnostic CTs, with a mean effective dose of 7.3 mSv (range 1.1-25.5 mSv). Drains remained in place for an average of 16.9 days (range 0-75 days), with an average of 0.9 (0-5) sinograms per patient in follow-up. The mean effective dose for all drainages and follow-up exams was 5.3 mSv (0.7-17.1) and 62% (32/52) of the children had effective doses less than 5 mSv. The majority of pediatric patients who have undergone CT-guided drain placements at our institution have received total radiation doses on par with diagnostic ranges. This information could be useful when describing the dose of radiation to parents and providers when CT-guided drain placement is necessary. (orig.)

Regulatory aspects of low doses control in Albania

International Nuclear Information System (INIS)

Dollani, K.; Kushe, R.

1997-01-01

In the present paper are described the status of regulatory aspects of low doses control as well as the existing procedures for their implementation in Albania. According to new Radiological Protection Act, approved by Parliament in 1995, the establishment of the infrastructures in radiation protection area is in course, accompanied by the installation and functioning of new equipment for low dose control. Based in many years experience it is concluded that personal doses of the workers added by practices in Albania are 1/10 of dose Emits. Some particular cases of overexposured workers were investigated. Last times the elements of the optimisation procedures (QA and QC) are outlined in the frame of improving regulatory aspects of low doses control. (author)

Low-Dose Radiation Induces Genes Promoting Cell Survival

International Nuclear Information System (INIS)

Liu, Shu-Zheng; Chen, Dong; Mu, Ying

1999-01-01

Apoptosis is an important process controlling homeostasis of the body. It is influenced by stimuli constantly arising from the external and internal environment of the organism. It is well known that radiation could induce apoptosis of cells in vitro and in vivo. However, the dose-effect relationship of apoptosis extending to the low-dose range has scarcely been studied. Here, the molecular basis of the phenomenon is explored by examining the changes in expression of some of the proapoptotic and antiapoptotic genes

Assessment of radiation dose awareness among pediatricians

International Nuclear Information System (INIS)

Thomas, Karen E.; Parnell-Parmley, June E.; Charkot, Ellen; BenDavid, Guila; Krajewski, Connie; Haidar, Salwa; Moineddin, Rahim

2006-01-01

There is increasing awareness among pediatric radiologists of the potential risks associated with ionizing radiation in medical imaging. However, it is not known whether there has been a corresponding increase in awareness among pediatricians. To establish the level of awareness among pediatricians of the recent publicity on radiation risks in children, knowledge of the relative doses of radiological investigations, current practice regarding parent/patient discussions, and the sources of educational input. Multiple-choice survey. Of 220 respondents, 105 (48%) were aware of the 2001 American Journal of Roentgenology articles on pediatric CT and radiation, though only 6% were correct in their estimate of the quoted lifetime excess cancer risk associated with radiation doses equivalent to pediatric CT. A sustained or transient increase in parent questioning regarding radiation doses had been noticed by 31%. When estimating the effective doses of various pediatric radiological investigations in chest radiograph (CXR) equivalents, 87% of all responses (and 94% of CT estimates) were underestimates. Only 15% of respondents were familiar with the ALARA principle. Only 14% of pediatricians recalled any relevant formal teaching during their specialty training. The survey response rate was 40%. Awareness of radiation protection issues among pediatricians is generally low, with widespread underestimation of relative doses and risks. (orig.)

Low-dose radiation as an environmental agent affecting intrauterine development

International Nuclear Information System (INIS)

Kameyama, Yoshiro

1982-01-01

The low-dose radiation effects which have been recognized in mammalian teratological studies are direct injuries to the particularly radiosensitive tissues of embryo and fetus, and increased incidences of spontaneous malformations and minor anomalies. The lowest radiation doses for manifestation of those effects in mice and rats are: 5 rad for resorption of preimplantation embryos; 5-10 rad for acute cytological changes such as pyknosis, cytoplasmic degeneration and mitotic delay; 5 rad for increasing frequency of spontaneous minor anomalies of the skeleton; 15-20 rad for malformations of the eye, brain and spinal cord; 20-25 rad for histogenetic and functional disorders of the central nervous system; and 20-25 rad for impaired fertility. Pregnant women who are subject to X-ray examination are much concerned about potential hazard of radiation to their offspring in utero. The above experimental findings suggest that the possibility of teratogenic effects of diagnostic radiation on human embryos and fetuses is extremely low, and probably negligible, given the proper dose control measures. (author)

Impact of radiation technique, radiation fraction dose, and total cisplatin dose on hearing. Retrospective analysis of 29 medulloblastoma patients

International Nuclear Information System (INIS)

Scobioala, Sergiu; Kittel, Christopher; Ebrahimi, Fatemeh; Wolters, Heidi; Eich, Hans Theodor; Parfitt, Ross; Matulat, Peter; Am Zehnhoff-Dinnesen, Antoinette

2017-01-01

To analyze the incidence and degree of sensorineural hearing loss (SNHL) resulting from different radiation techniques, fractionation dose, mean cochlear radiation dose (D mean ), and total cisplatin dose. In all, 29 children with medulloblastoma (58 ears) with subclinical pretreatment hearing thresholds participated. Radiotherapy (RT) and cisplatin had been applied sequentially according to the HIT MED Guidance. Audiological outcomes up to the latest follow-up (median 2.6 years) were compared. Bilateral high-frequency SNHL was observed in 26 patients (90%). No significant differences were found in mean hearing threshold between left and right ears at any frequency. A significantly better audiological outcome (p < 0.05) was found after tomotherapy at the 6 kHz bone-conduction threshold (BCT) and left-sided 8 kHz air-conduction threshold (ACT) than after a combined radiotherapy technique (CT). Fraction dose was not found to have any impact on the incidence, degree, and time-to-onset of SNHL. Patients treated with CT had a greater risk of SNHL at high frequencies than tomotherapy patients even though D mean was similar. Increase in severity of SNHL was seen when the total cisplatin dose reached above 210 mg/m 2 , with the highest abnormal level found 8-12 months after RT regardless of radiation technique or fraction dose. The cochlear radiation dose should be kept as low as possible in patients who receive simultaneous cisplatin-based chemotherapy. The risk of clinically relevant HL was shown when D mean exceeds 45 Gy independent of radiation technique or radiation regime. Cisplatin ototoxicity was shown to have a dose-dependent effect on bilateral SNHL, which was more pronounced in higher frequencies. (orig.) [de

Effect of low dose ionizing radiation upon concentration of

International Nuclear Information System (INIS)

Viliae, M.; Kraljeviae, P.; Simpraga, M.; Miljaniae, S.

2004-01-01

It is known that low dose ionizing radiation might have stimulating effects (Luckey, 1982, Kraljeviae, 1988). This fact has also been confirmed in the previous papers of Kraljeviae et al. (2000-2000a; 2001). Namely, those authors showed that irradiation of chicken eggs before incubation by a low dose of 0.15 Gy gamma radiation increases the activity aspartateaminotrasferases (AST) and alanine-aminotransferases (ALT) in blood plasma of chickens hatched from irradiated eggs, as well as growth of chickens during the fattening period. Low doses might also cause changes in the concentration of some biochemical parameters in blood plasma of the same chickens such as changes in the concentration of total proteins, glucose and cholesterol. In this paper, an attempt was made to investigate the effects of low dose gamma radiation upon the concentration of sodium and potassium in the blood plasma of chickens which were hatched from eggs irradiated on the 19th day of incubation by dose of 0.15 Gy. Obtained results were compared with the results from the control group (chickens hatched from nonirradiated eggs). After hatching, all other conditions were the same for both groups. Blood samples were drawn from heart, and later from the wing vein on days 1, 3, 5, 7, 10, 20, 30 and 42. The concentration of sodium and potassium was determined spectrophotometrically by atomic absorbing spectrophotometer Perkin-Elmer 1100B. The concentration of sodium and potassium in blood plasma of chickens hatched from eggs irradiated on the 19th day of incubation by dose of 0.15 Gy indicated a statistically significant increase (P>0.01) only on the first day of the experiment. Obtained results showed that irradiation of eggs on the 19th day of incubation by dose of 0.15 Gy gamma radiation could have effects upon the metabolism of electrolytes in chickens. (Author)

Development, validation and routine control of a radiation process

International Nuclear Information System (INIS)

Kishor Mehta

2010-01-01

Today, radiation is used in industrial processing for variety of applications; from low doses for blood irradiation to very high doses for materials modification and even higher for gemstone colour enhancement. At present, radiation is mainly provided by either radionuclides or machine sources; cobalt-60 is the most predominant radionuclide in use. Currently, there are several hundred irradiation facilities worldwide. Similar to other industries, quality management systems can assist radiation processing facilities in enhancing customer satisfaction and maintaining and improving product quality. To help fulfill quality management requirements, several national and international organizations have developed various standards related to radiation processing. They all have requirements and guidelines for development, validation and routine control of the radiation process. For radiation processing, these three phases involve the following activities. Development phase includes selecting the type of radiation source, irradiation facility and the dose required for the process. Validation phase includes conducting activities that give assurance that the process will be successful. Routine control then involves activities that provide evidence that the process has been successfully realized. These standards require documentary evidence that process validation and process control have been followed. Dosimetry information gathered during these processes provides this evidence. (authors)

Agriculture-related radiation dose calculations

International Nuclear Information System (INIS)

Furr, J.M.; Mayberry, J.J.; Waite, D.A.

1987-10-01

Estimates of radiation dose to the public must be made at each stage in the identification and qualification process leading to siting a high-level nuclear waste repository. Specifically considering the ingestion pathway, this paper examines questions of reliability and adequacy of dose calculations in relation to five stages of data availability (geologic province, region, area, location, and mass balance) and three methods of calculation (population, population/food production, and food production driven). Calculations were done using the model PABLM with data for the Permian and Palo Duro Basins and the Deaf Smith County area. Extra effort expended in gathering agricultural data at succeeding environmental characterization levels does not appear justified, since dose estimates do not differ greatly; that effort would be better spent determining usage of food types that contribute most to the total dose; and that consumption rate and the air dispersion factor are critical to assessment of radiation dose via the ingestion pathway. 17 refs., 9 figs., 32 tabs

Global DNA methylation responses to low dose radiation exposure

International Nuclear Information System (INIS)

Newman, M.R.; Ormsby, R.J.; Blyth, B.J.; Sykes, P.J.; Bezak, E.

2011-01-01

Full text: High radiation doses cause breaks in the DNA which are considered the critical lesions in initiation of radiation-induced cancer. However, at very low radiation doses relevant for the general public, the induction of such breaks will be rare, and other changes to the DNA such as DNA methylation which affects gene expression may playa role in radiation responses. We are studying global DNA methylation after low dose radiation exposure to determine if low dose radiation has short- and/or long-term effects on chromatin structure. We developed a sensitive high resolution melt assay to measure the levels of DNA methylation across the mouse genome by analysing a stretch of DNA sequence within Long Interspersed Nuclear Elements-I (LINE I) that comprise a very large proportion of the mouse and human genomes. Our initial results suggest no significant short-term or longterm) changes in global NA methylation after low dose whole-body X-radiation of 10 J1Gyor 10 mGy, with a significant transient increase in NA methylation observed I day after a high dose of I Gy. If the low radiation doses tested are inducing changes in bal DNA methylation, these would appear to be smaller than the variation observed between the sexes and following the general stress of the sham-irradiation procedure itself. This research was funded by the Low Dose Radiation Research Program, Biological and Environmental Research, US DOE, Grant DE-FG02-05ER64104 and MN is the recipient of the FMCF/BHP Dose Radiation Research Scholarship.

Chronic low dose radiation exposure and oxidative stress in radiation workers

International Nuclear Information System (INIS)

Ali, S.S.; Bhatt, M.B.; Kulkarni, MM.; Rajan, R.; Singh, B.B.; Venkataraman, G.

1996-01-01

Free radicals have been implicated in the pathogenesis of several human diseases. In this study free radical stress due to low dose chronic radiation exposures of radiation workers was examined as a possible atherogenic risk factor. Data on lipid profiles, lipid peroxidation and reduced glutathione content in blood indicated an absence of correlation with radiation doses up to 125 mSv. (author). 13 refs., 1 fig

Radiation Doses Received by the Irish Population

International Nuclear Information System (INIS)

Colgan, P.A.; Organo, C.; Hone, C.; Fenton, D.

2008-05-01

Some chemical elements present in the environment since the Earth was formed are naturally radioactive and exposure to these sources of radiation cannot be avoided. There have also been additions to this natural inventory from artificial sources of radiation that did not exist before the 1940s. Other sources of radiation exposure include cosmic radiation from outer space and the use of radiation in medical diagnosis and treatment. There can be large variability in the dose received by invividual members of the population from any given source. Some sources of radiation expose every member of the population while, in other cases, only selected individuals may be exposed. For example, natural radioactivity is found in all soils and therefore everybody receives some radiation dose from this activity. On the other hand, in the case of medical exposures, only those who undergo a medical procedure using radiation will receive a radiation dose. The Radiological Protection Institute of Ireland (RPII) has undertaken a comprehensive review of the relevant data on radiation exposure in Ireland. Where no national data have been identified, the RPII has either undertaken its own research or has referred to the international literature to provide a best estimate of what the exposure in Ireland might be. This has allowed the relative contribution of each source to be quantified. This new evaluation is the most up-to-date assessment of radiation exposure and updates the assessment previously reported in 2004. The dose quoted for each source is the annual 'per caput' dose calculated on the basis of the most recently available data. This is an average value calculated by adding the doses received by each individual exposed to a given radiation source and dividing the total by the current population of 4.24 million. All figures have been rounded, consistent with the accuracy of the data. In line with accepted international practice, where exposure takes place both indoors and

Reduction in life span on normal human fibroblasts exposed to low-dose radiation in heavy-ion radiation field

International Nuclear Information System (INIS)

Suzuki, Masao; Yamaguchi, Chizuru; Yasuda, Hiroshi; Uchihori, Yukio; Fujitaka, Kazunobu

2003-01-01

We studied the effect of in vitro life span in normal human fibroblasts exposed to chronically low-dose radiation in heavy-ion radiation field. Cells were cultured in a CO 2 incubator, which was set in the irradiation room for biological study of heavy ions in the Heavy Ion Medical Accelerator in Chiba (HIMAC) at National Institute of Radiological Sciences (NIRS), and exposed to scattered radiations produced with heavy-ion beams throughout the life span of the cell population. Absorbed dose, which was measured using a thermoluminescence dosimeter(TLD) and a Si-semiconductor detector, was to be 1.4 mGy per day when operating the HIMAC machine for biological experiments. The total population doubling number of the exposed cells reduced to 79-93% of non-exposed control cells in the three independent experiments. There is evidence that the exposure of chronically low-dose radiation in heavy-ion radiation field promotes the life-span reduction in cellular level. (author)

Problems Concerning Dose Assessments in Epidemiology of High Background Radiation Areas of Yangjiang, China (invited paper)

International Nuclear Information System (INIS)

Wei, L.X.; Yuan, Y.L.

1998-01-01

The purpose of this study on radiation levels and dose assessments in the epidemiology of a high background radiation area (HBRA) and the control area (CA) is to respond to the needs of epidemiology in these areas, where the inhabitants are continuously exposed to low dose, low dose rate ionising radiation. A brief description is given of how the research group evaluated the feasibility of the investigation by analysing the population size and the radiation levels, how simple reliable methods were used to get the individual annual dose for every cohort member, and how the cohort members were classified into various dose groups for dose-effect relationship analysis. Finally, the use of dose group classification for cancer mortality studies is described. (author)

Evaluation of radiation doses from radioactive drugs

International Nuclear Information System (INIS)

Halperin, J.A.; Grove, G.R.

1977-01-01

Radioactive new drugs are regulated by the Food and Drug Administration (FDA) in the United States. Before a new drug can be marketed it must have an approved New Drug Application (NDA). Clinical investigations of a radioactive new drug are carried out under a Notice of Claimed Investigational Exemption for a New Drug (IND), submitted to the FDA. In the review of the IND, radiation doses are projected on the basis of experimental data from animal models and from calculations based upon radiation characteristics, predicted biodistribution of the drug in humans, and activity to be administered. FDA physicians review anticipated doses and prevent clinical investigations in humans when the potential risk of the use of a radioactive substance outweighs the prospect of achieving beneficial results from the administration of the drug. In the evaluation of an NDA, FDA staff attempt to assure that the intended diagnostic or therapeutic effect is achievable with the lowest practicable radiation dose. Radiation doses from radioactive new drugs are evaluated by physicians within the FDA. Important radioactive new drugs are also evaluated by the Radiopharmaceuticals Advisory Committee. FDA also supports the Center for Internal Radiation Dosimetry at Oak Ridge, to provide information regarding in vivo distribution and dosimetry to critical organs and the whole body from radioactive new drugs. The process for evaluation of radiation doses from radioactive new drugs for protection against use of unnecessary radiation exposure by patients in nuclear medicine procedures, a

Flight attendant radiation dose from solar particle events.

Science.gov (United States)

Anderson, Jeri L; Mertens, Christopher J; Grajewski, Barbara; Luo, Lian; Tseng, Chih-Yu; Cassinelli, Rick T

2014-08-01

Research has suggested that work as a flight attendant may be related to increased risk for reproductive health effects. Air cabin exposures that may influence reproductive health include radiation dose from galactic cosmic radiation and solar particle events. This paper describes the assessment of radiation dose accrued during solar particle events as part of a reproductive health study of flight attendants. Solar storm data were obtained from the National Oceanic and Atmospheric Administration Space Weather Prediction Center list of solar proton events affecting the Earth environment to ascertain storms relevant to the two study periods (1992-1996 and 1999-2001). Radiation dose from exposure to solar energetic particles was estimated using the NAIRAS model in conjunction with galactic cosmic radiation dose calculated using the CARI-6P computer program. Seven solar particle events were determined to have potential for significant radiation exposure, two in the first study period and five in the second study period, and over-lapped with 24,807 flight segments. Absorbed (and effective) flight segment doses averaged 6.5 μGy (18 μSv) and 3.1 μGy (8.3 μSv) for the first and second study periods, respectively. Maximum doses were as high as 440 μGy (1.2 mSv) and 20 flight segments had doses greater than 190 μGy (0.5 mSv). During solar particle events, a pregnant flight attendant could potentially exceed the equivalent dose limit to the conceptus of 0.5 mSv in a month recommended by the National Council on Radiation Protection and Measurements.

Natural radiation dose to Gammarus from Hudson river

International Nuclear Information System (INIS)

Paschoa, A.S.; Wrenn, M.E.; Eisenbud, M.

1979-01-01

The purpose of this investigation is to evaluate the natural radiation dose rate to whole body and components of the Gammarus species, a zooplankton which occurs in the Hudson River among other places, and to compare the results with the upper limits of dose rates from man-made sources. The alpha dose rates to the exoskeleton and soft tissues are about 10 times the average alpha dose rate to the whole body, assuming uniform distribution of 226 Ra. The natural alpha radiation dose rate to Gammarus represents only about 5% of the total natural dose to the organism, i.e., 492 mrad/yr. The external dose rate due to 40 K, 238 U plus daughters and 232 Th plus daughters accumulated in the sediments comprise 91% of that total natural dose rate, the remaining percentage being due to natural internal beta emitters and cosmic radiation. Man-made sources can cause an external dose rate up to 224 mrad/yr, which comprises roughly 1/3 of the total dose rate (up to 716 mrad/yr; natural plus man-made) to the Gammarus of Hudson River in front of Indian Point Nuclear Power Station. However, in terms of dose-equivalent the natural sources of radiation would contribute more than 75% of the total dose to Gammarus

Concomitant chemo-radiotherapy and local dose of radiation as risk factors for second malignant neoplasms after cancer in childhood: a case control study

International Nuclear Information System (INIS)

Guerin, S.; Guibout, C.; Vathaire, F. de; Shamsaldin, A.; Diallo, I.; Oberlin, O.; Hartmann, O.; Le Deley, M.C.; Dondon, M.G.; Hawkins, M.

2006-01-01

Radiotherapy and chemotherapy are associated with an increased risk of a second malignant neoplasm. after a cancer during childhood. This study specified the dose effect relationship between the local dose of radiation received at the site of the second malignant neoplasm and the risk of a second malignant neoplasm.It also investigated the effect of chemo radiotherapy on the risk of second malignant neoplasm. An European cohort of 4581 patients, treated for a solid cancer during childhood have been included in the study. 153 cases with a second malignant neoplasm, and 442 controls were matched according to sex, age at first cancer, calendar year, type of first cancer and follow-up. The local dose of radiation was estimated at the site of the second malignant neoplasm, for each case and at the same site, for his matched control. In conclusion, radiation was the foremost treatment related risk factor for the occurrence of a second malignant neoplasm. Compared to sequential treatment, concomitant chemo radiotherapy may lead to a higher risk of a second malignant neoplasm. (N.C.)

Radiochromic Plastic Films for Accurate Measurement of Radiation Absorbed Dose and Dose Distributions

DEFF Research Database (Denmark)

McLaughlin, W. L.; Miller, Arne; Fidan, S.

1977-01-01

of dose rate (1–1014 rad s−1). Upon irradiation of the film, the profile of the radiation field is registered as a permanent colored image of the dose distribution. Unlike most other types of dyed plastic dose meters, the optical density produced by irradiation is in most cases stable for periods...... of many polymeric systems in industrial radiation processing. The result is that errors due to energy dependence of response of the radiation sensor are effectively reduced, since the spectral sensitivity of the dose meter matches that of the polymer of interest, over a wide range of photon and electron...

Dose received by radiation workers in Australia, 1991

Energy Technology Data Exchange (ETDEWEB)

Morris, N D

1994-07-01

Exposure to radiation can cause genetic defects or cancer. People who use sources of radiation as part of their employment are potentially at a greater risk than others owing to the possibility of their being continually exposed to small radiation doses over a long period. In Australia, the National Health and Medical Research Council has established radiation protection standards and set annual effective dose limits for radiation workers in order to minimise the chance of adverse effects occurring. These standards are based on the the recommendations of the International Commission on Radiological Protection (ICRP 1990). In order to ensure that the prescribed limits are not exceeded and to ensure that doses are kept to a minimum, some sort of monitoring is necessary. The primary purpose of this report is to provide data on the distribution of effective doses for different occupational categories of radiation worker in Australia. The total collective effective dose was found to be of the order of 4.9 Sv for a total of 34750 workers. 9 refs., 16 tabs., 6 figs.

Dose received by radiation workers in Australia, 1991

International Nuclear Information System (INIS)

Morris, N.D.

1994-07-01

Exposure to radiation can cause genetic defects or cancer. People who use sources of radiation as part of their employment are potentially at a greater risk than others owing to the possibility of their being continually exposed to small radiation doses over a long period. In Australia, the National Health and Medical Research Council has established radiation protection standards and set annual effective dose limits for radiation workers in order to minimise the chance of adverse effects occurring. These standards are based on the the recommendations of the International Commission on Radiological Protection (ICRP 1990). In order to ensure that the prescribed limits are not exceeded and to ensure that doses are kept to a minimum, some sort of monitoring is necessary. The primary purpose of this report is to provide data on the distribution of effective doses for different occupational categories of radiation worker in Australia. The total collective effective dose was found to be of the order of 4.9 Sv for a total of 34750 workers. 9 refs., 16 tabs., 6 figs

Automatization of the radiation control measurements

International Nuclear Information System (INIS)

Seki, Akio; Ogata, Harumi; Horikoshi, Yoshinori; Shirai, Kenji

1988-01-01

Plutonium Fuel Production Facility (PFPF) was constructed to fabricate the MOX fuels for 'MONJU' and 'JOYO' reactors and to develop the practical fuel fabricating technology. For the fuel fabrication process in this facility, centralized controlling system is being adopted for the mass production of the fuel and reduction of the radiation exposure dose. Also, the radiation control systems are suitable for the large-scale facility and the automatic-remote process of the fuel fabrication. One of the typical radiation control systems is the self moving survey system which has been developed by PNC and adopted for the automatic routine monitoring. (author)

Evaluation of Patient Radiation Dose during Orthopedic Surgery

International Nuclear Information System (INIS)

Osman, H; Elzaki, A.; Sam, A.K.; Sulieman, A.

2013-01-01

The number of orthopedic procedures requiring the use of the fluoroscopic guidance has increased over the recent years. Consequently the patient exposed to un avoidable radiation doses. The aim of the current study was to evaluate patient radiation dose during these procedures.37 patients under went dynamic hip screw (DHS) and dynamic cannulated screw (DCS) were evaluated using calibrated Thermolumincent Dosimeters (TLDs), under carm fluoroscopic machines ,in three centers in Khartoum-Sudan. The mean Entrance Skin Dose (ESD) was 7.9 m Gy per procedure. The bone marrow and gonad organ exposed to significant doses. No correlation was found between ESD and Body Mass Index (BMI), or patient weight. Well correlation was found between kilo voltage applied and ESD. Orthopedic surgeries delivered lower radiation dose to patients than cardiac catheterization or hysterosalpingraphy (HSG) procedures. More study should be implemented to follow radiation dose before surgery and after surgery

Radiation Dose-Response Relationships and Risk Assessment

International Nuclear Information System (INIS)

Strom, Daniel J.

2005-01-01

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

Radiation effects of high and low doses

International Nuclear Information System (INIS)

El-Naggar, A.M.

1998-01-01

The extensive proliferation of the uses and applications of atomic and nuclear energy resulted in possible repercussions on human health. The prominent features of the health hazards that may be incurred after exposure to high and low radiation doses are discussed. The physical and biological factors involved in the sequential development of radiation health effects and the different cellular responses to radiation injury are considered. The main criteria and features of radiation effects of high and low doses are comprehensively outlined

Bio-indicators for radiation dose assessment

International Nuclear Information System (INIS)

Trivedi, A.

1990-12-01

In nuclear facilities, such as Chalk River Laboratories, dose to the atomic radiation workers (ARWs) is assessed routinely by using physical dosimeters and bioassay procedures in accordance with regulatory recommendations. However, these procedures may be insufficient in some circumstances, e.g., in cases where the reading of the physical dosimeters is questioned, in cases of radiation accidents where the person(s) in question was not wearing a dosimeter, or in the event of a radiation emergency when an exposure above the dose limits is possible. The desirability of being able to assess radiation dose on the basis of radio-biological effects has prompted the Dosimetric Research Branch to investigate the suitability of biological devices and techniques that could be used for this purpose. Current biological dosimetry concepts suggest that there does not appear to be any bio-indicator that could reliably measure the very low doses that are routinely measured by the physical devices presently in use. Nonetheless, bio-indicators may be useful in providing valuable supplementary information in cases of unusual radiation exposures, such as when the estimated body doses are doubtful because of lack of proper physical measurements, or in cases where available results need to be confirmed for medical treatment plannings. This report evaluates the present state of biological dosimetry and, in particular, assesses the efficiency and limits of individual indicators. This has led to the recommendation of a few promising research areas that may result in the development of appropriate biological dosimeters for operational and emergency needs at Chalk River

Plastic for indicating a radiation dose

International Nuclear Information System (INIS)

Hori, Y.; Yoshikawa, N.; Ohmori, S.

1975-01-01

A plastic film suitable for indicating radiation dose contains a chlorine polymer, at least one acid sensitive coloring agent and a plasticizer. The film undergoes a distinct change of color in response to a given radiation dose, the degree of change proportional to the total change. These films may be stored for a long period without loss of sensitivity, and have good color stability after irradiation. (auth)

Health Effects of Exposure to Low Dose of Radiation

International Nuclear Information System (INIS)

Alatas, Zubaidah

2003-01-01

Human beings are exposed to natural radiation from external sources include radionuclides in the earth and cosmic radiation, and by internal radiation from radionuclides, mainly uranium and thorium series, incorporated into the body. Living systems have adapted to the natural levels of radiation and radioactivity. But some industrial practices involving natural resources enhance these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Biological effects of ionizing radiation are the outcomes of physical and chemical processes that occur immediately after the exposure, then followed by biological process in the body. These processes will involve successive changes in the molecular, cellular, tissue and whole organism levels. Any dose of radiation, no matter how small, may produce health effects since even a single ionizing event can result in DNA damage. The damage to DNA in the nucleus is considered to be the main initiating event by which radiation causes damage to cells that results in the development of cancer and hereditary disease. It has also been indicated that cytogenetic damage can occur in cells that receive no direct radiation exposure, known as bystander effects. This paper reviews health risks of low dose radiation exposure to human body causing stochastic effects, i.e. cancer induction in somatic cells and hereditary disease in genetic cells. (author)

Effects of low dose radiation on tumor-bearing mice

International Nuclear Information System (INIS)

Feng Li; Hou Dianjun; Huang Shanying; Deng Daping; Wang Linchao; Cheng Yufeng

2007-01-01

Objective: To explore the effects of low-dose radiation on tumor-bearing mice and radiotherapy induced by low-dose radiation. Methods: Male Wistar mice were implanted with Walker-256 sarcoma cells in the right armpit. On day 4, the mice were given 75 mGy whole-body X-ray radiation. From the fifth day, tumor volume was measured, allowing for the creation of a graph depicting tumor growth. Lymphocytes activity in mice after whole-body X-ray radiation with LDR was determinned by FCM. Cytokines level were also determined by ELISA. Results: Compared with the radiotherapy group, tumor growth was significantly slower in the mice pre-exposed to low-dose radiation (P<0.05), after 15 days, the average tumor weight in the mice pre- exposed to low-dose radiation was also significantly lower (P<0.05). Lymphocytes activity and the expression of the CK in mice after whole-body y-ray radiation with LDR increased significantly. Conclusions: Low-dose radiation can markedly improve the immune function of the lymphocyte, inhibit the tumor growth, increase the resistant of the high-dose radiotherapy and enhance the effect of radiotherapy. (authors)

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

Energy Technology Data Exchange (ETDEWEB)

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

2018-03-15

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

A micro-controller based palm-size radiation monitor

International Nuclear Information System (INIS)

Bhingare, R.R.; Bajaj, K.C.; Kannan, S.

2001-01-01

A micro-controller based, palm-size radiation monitor, PALMRAD, using a silicon P-N junction diode as a detector has been developed. It is useful for radiation protection monitoring during radiation emergency as well as radioactive source loading operations. Some of the features of PALMRAD developed are the use of a semiconductor diode as the detector, simultaneous display of integrated dose and dose rate on a 16-digit alpha numeric LCD display, measurable integrated dose range from 1 μSv to 5000 μSv and dose rate range from 1 mSv/h to 1,000 mSv/h, RS 232C serial interface for connection to a Personal Computer,-storage of integrated dose and dose rate readings, recall of stored readings on LCD display, presentable integrated dose alarm from 1 μSv to 5000 μSv and dose rate from 1 mSv/h to 1,000 mSv/h, battery status and memory status check during measurement, LCD display with LED back-lighting, etc. (author)

Severe accident management: radiation dose control, Fukushima Daiichi and TMI-2 nuclear plant accidents

International Nuclear Information System (INIS)

Shaw, Roger

2014-01-01

This presentation presents valuable dose information related to the Fukushima Daiichi and Three Mile Island Unit 2 (TMI-2) Nuclear Plant accidents. Dose information is provided for what is well known for TMI-2, and what is available for Fukushima Daiichi. Particular emphasis is placed on the difference between the type of reactors involved, overarching plant damage issues, and radiation worker dose outcomes. For TMI-2, more in depth dose data is available for the accident and the subsequent recovery efforts. The comparisons demonstrate the need to understand the wide variation in potential dose management measures and outcomes for severe reactor accidents. (author)

Development of Plant Application Technique of Low Dose Radiation

Energy Technology Data Exchange (ETDEWEB)

Chung, Byung Yeoup; Kim, Jae Sung; Lim, Yong Taek (and others)

2007-07-15

The project was carried out to achieve three aims. First, development of application techniques of cell-stimulating effects by low-dose radiation. Following irradiation with gamma-rays of low doses, beneficial effects in crop germination, early growth, and yield were investigated using various plant species and experimental approaches. For the actual field application, corroborative studies were also carried out with a few concerned experimental stations and farmers. Moreover, we attempted to establish a new technique of cell cultivation for industrial mass-production of shikonin, a medicinal compound from Lithospermum erythrorhizon and thereby suggested new application fields for application techniques of low-dose radiation. Second, elucidation of action mechanisms of ionizing radiation in plants. By investigating changes in plant photosynthesis and physiological metabolism, we attempted to elucidate physiological activity-stimulating effects of low-dose radiation and to search for radiation-adaptive cellular components. Besides, analyses of biochemical and molecular biological mechanisms for stimulus-stimulating effects of low-dose radiation were accomplished by examining genes and proteins inducible by low-dose radiation. Third, development of functional crop plants using radiation-resistant factors. Changes in stress-tolerance of plants against environmental stress factors such as light, temperature, salinity and UV-B stress after exposed to low-dose gamma-rays were investigated. Concerned reactive oxygen species, antioxidative enzymes, and antioxidants were also analyzed to develop high value-added and environment-friendly functional plants using radiation-resistant factors. These researches are important to elucidate biological activities increased by low-dose radiation and help to provide leading technologies for improvement of domestic productivity in agriculture and development of high value-added genetic resources.

Development of Plant Application Technique of Low Dose Radiation

International Nuclear Information System (INIS)

Chung, Byung Yeoup; Kim, Jae Sung; Lim, Yong Taek

2007-07-01

The project was carried out to achieve three aims. First, development of application techniques of cell-stimulating effects by low-dose radiation. Following irradiation with gamma-rays of low doses, beneficial effects in crop germination, early growth, and yield were investigated using various plant species and experimental approaches. For the actual field application, corroborative studies were also carried out with a few concerned experimental stations and farmers. Moreover, we attempted to establish a new technique of cell cultivation for industrial mass-production of shikonin, a medicinal compound from Lithospermum erythrorhizon and thereby suggested new application fields for application techniques of low-dose radiation. Second, elucidation of action mechanisms of ionizing radiation in plants. By investigating changes in plant photosynthesis and physiological metabolism, we attempted to elucidate physiological activity-stimulating effects of low-dose radiation and to search for radiation-adaptive cellular components. Besides, analyses of biochemical and molecular biological mechanisms for stimulus-stimulating effects of low-dose radiation were accomplished by examining genes and proteins inducible by low-dose radiation. Third, development of functional crop plants using radiation-resistant factors. Changes in stress-tolerance of plants against environmental stress factors such as light, temperature, salinity and UV-B stress after exposed to low-dose gamma-rays were investigated. Concerned reactive oxygen species, antioxidative enzymes, and antioxidants were also analyzed to develop high value-added and environment-friendly functional plants using radiation-resistant factors. These researches are important to elucidate biological activities increased by low-dose radiation and help to provide leading technologies for improvement of domestic productivity in agriculture and development of high value-added genetic resources

Progress in high-dose radiation dosimetry

International Nuclear Information System (INIS)

Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.; Chadwick, K.H.

1981-01-01

The last decade has witnessed a deluge of new high-dose dosimetry techniques and expanded applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Reference systems also include a number of chemical dose meters: ferrous sulphate, ferrous-cupric sulphate, and ceric sulphate acidic aqueous solutions. Requirements for stable and reliable transfer dose meters have led to further developments of several important high-dose systems: amino acids and saccharides analysed by ESR or lyoluminescence, thermoluminescent materials, radiochromic dyes and plastics, ceric-cerous solutions analysed by potentiometry, and ethanol-chlorobenzene solutions analysed by high-frequency oscillometry. A number of other prospective dose meters are also treated in this review. In addition, an IAEA programme of high-dose standardization and intercomparison for industrial radiation processing is described. (author)

Plants as warning signal for exposure to low dose radiation

International Nuclear Information System (INIS)

Rusli Ibrahim; Norhafiz Talib

2012-01-01

The stamen-hair system of Tradescantia for flower colour has proven to be one of the most suitable materials to study the frequency of mutations induced by low doses of various ionizing radiations and chemical mutagens. The system has also been used successfully for detecting mutagenic synergisms among chemical mutagens and ionizing radiations as well as for studying the variations of spontaneous mutation frequency. In this study of radiobiology, the main objective is to observe somatic mutation (occurrence of pink cells from blue cells) induced on stamen hairs of five Tradescantia sp. available in Malaysia after exposure to low doses of chronic gamma irradiation using Gamma Green House. Pink cells appeared only on Tradescantia Pallida Purpurea stamen hairs after 13 days of exposure to irradiation with different doses of gamma rays. The highest number of stamens with pink cells was recorded from flowers irradiated with the highest dose of 6.37 Gy with 0.07 Gy/ h of dose rate. The lowest number of stamens with pink cells was recorded with an average of 0.57, irradiated with the lowest dose of 0.91 Gy with 0.01 Gy/ h of dose rate. There were no pink cells observed on Tradescantia Spathaceae Discolor after exposure to different doses of gamma rays. Similar negative results were observed for the control experiments. The principal cells in this assay are the mitotic stamen hair cells developing in the young flower buds. After exposure to radiation, the heterozygous dominant blue character of the stamen hair cell is prevented, resulting in the appearance of the recessive pink color. Furthermore, no pink cell appears on all species of Tradescantia spathaceae after irradiated with different doses of gamma rays. The sensitivity of the Tradescantia has been used widely and has demonstrated the relation between radiation dose and frequency of mutation observed at low doses which can contribute to the effects of low doses and their consequences for human health. This system

Dose effect relationships in cervical and thoracic radiation myelopathies

International Nuclear Information System (INIS)

Holdorff, B.

1980-01-01

The course and prognosis of radiation myelopathies are determined by 3 factors: the segmental (vertical) location of the lesion, the extent of the transverse syndrome (complete or incomplete) and the radiation dose. The median spinal dose in cervical radiation myelopathies with fatal outcome was higher than in survivals with an incomplete transverse syndrome. In thoracic radiation myelopathies a dose difference between complete and incomplete transverse syndromes could be found as well. Incomplete transverse syndromes as submaximum radiation injuries are more suitable for the determination of the spinal tolerance dose than complete transverse syndromes. The lowest threshold could be stated for cases following high-volume irradiation of the lymphatic system. (Auth.)

Individual dose control of workers

International Nuclear Information System (INIS)

Keverling Buisman, A.S.

1990-01-01

This publication has the character of a set of recommendations towards in practice working radiation protection specialists who are involved within their company or institute with the organization and performance of measurements in order to control the individual radiation burden caused by external exposition and internal contamination in applying radioactive materials and radiation apparatus. This publication gives information about the practical performance of personnel dosimetry at external exposure with a personnel dosimeter, which is carried on the body. The individual control of internal contamination is a much more complicated task. This publication assumes, with regard to this part, that people who are involved with it have been schooled as a radiation specialist level-3. For this part this publication contains numerical information needed for assessing of the individual effective follow-dose equivalence in occurring cases. A list with data of much used radionuclides is included. Also dosimetric data are presented which may be useful in case of contamination of skin and wounds. (author). 14 refs.; 2 figs.; 17 tabs

Control panel for radiation around reactors (1963); Tableaux de controle des radiations aupres des piles (1963)

Energy Technology Data Exchange (ETDEWEB)

Candes, P; Barthoux, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

This report outlines the general philosophy of radiation control in French reactors and their annexes. The supervision is carried out continuously from a central control panel on which appear all the measurements made and the alarm signals. The equipment is described; one item makes it possible to measure simultaneously the radioactive dusts and gases. The specifications of the alarm system, which is considered to be the most important are given. Finally a new measuring technique is proposed which makes it possible to reduce considerably the cost of radiation control while at the same time providing the results in a form in which they can be easily treated, in particular in the case of the calculation of total doses. (authors) [French] Ce rapport definit la philosophie generale du controle des radiations dans les piles francaises et dans leurs annexes. La surveillance se fait d'une maniere continue a partir d'un tableau de controle centralise ou sont reportees toutes les mesures et les signalisations d'alarme. On decrit les appareils utilises, dont un permet la mesure simultanee des poussieres et gaz radioactifs, et on definit les specifications de la fonction alarme qui est consideree comme la plus importante. Enfin on propose une nouvelle technique de mesure qui permettrait de reduire considerablement le cout du controle des radiations tout en fournissant des resultats plus facilement exploitables, en particulier pour le calcul des doses integrees. (auteurs)

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

Energy Technology Data Exchange (ETDEWEB)

Kettunen, A. [Oulu Univ. (Finland)

2004-05-01

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

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

International Nuclear Information System (INIS)

Kettunen, A.

2004-05-01

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Occupational radiation dose in Indonesia 1981-1986

International Nuclear Information System (INIS)

Hiswara, E.; Ismono, A.

1993-01-01

Occupational radiation dose in Indonesia 1981-1986. This paper presents the occupational radiation dose in Indonesia during the period of 1981-1986. The highest collective dose accurated in 1983 was calculated to be 2.68 man-Sv, with the maximum mean dose per worker, who received dose more than zero, was around 11.07 mSv in the same year. In 1985, a relative collective dose from medical occupations of 1.88 man mSv for 10 6 population was estimated based on its total collective dose of 0.31 man-mSv. The total number of workers who received annual collective dose less than 5 mSv varied from 97.0% in 1981 to 99.5% in 1986. As a group, the industrial occupations has considerably higher risk in receiving a dose than others. (authors). 11 refs., 7 tabs

Single Low-Dose Ionizing Radiation Induces Genotoxicity in Adult Zebrafish and its Non-Irradiated Progeny.

Science.gov (United States)

Lemos, J; Neuparth, T; Trigo, M; Costa, P; Vieira, D; Cunha, L; Ponte, F; Costa, P S; Metello, L F; Carvalho, A P

2017-02-01

This study investigated to what extent a single exposure to low doses of ionizing radiation can induce genotoxic damage in irradiated adult zebrafish (Danio rerio) and its non-irradiated F1 progeny. Four groups of adult zebrafish were irradiated with a single dose of X-rays at 0 (control), 100, 500 and 1000 mGy, respectively, and couples of each group were allowed to reproduce following irradiation. Blood of parental fish and whole-body offspring were analysed by the comet assay for detection of DNA damage. The level of DNA damage in irradiated parental fish increased in a radiation dose-dependent manner at day 1 post-irradiation, but returned to the control level thereafter. The level of DNA damage in the progeny was directly correlated with the parental irradiation dose. Results highlight the genotoxic risk of a single exposure to low-dose ionizing radiation in irradiated individuals and also in its non-irradiated progeny.

The leaded apron revisited: does it reduce gonadal radiation dose in dental radiology

Energy Technology Data Exchange (ETDEWEB)

Wood, R.E.; Harris, A.M.; van der Merwe, E.J.; Nortje, C.J. (Ontario Cancer Institute, Princess Margaret Hospital, Toronto (Canada))

1991-05-01

A tissue-equivalent anthropomorphic human phantom was used with a lithium fluoride thermoluminescent dosimetry system to evaluate the radiation absorbed dose to the ovarian and testicular region during dental radiologic procedures. Measurements were made with and without personal lead shielding devices consisting of thyroid collar and apron of 0.25 mm lead thickness equivalence. The radiation absorbed dose with or without lead shielding did not differ significantly from control dosimeters in vertex occlusal and periapical views (p greater than 0.05). Personal lead shielding devices did reduce gonadal dose in the case of accidental exposure (p less than 0.05). A leaded apron of 0.25 mm lead thickness equivalent was permeable to radiation in direct exposure testing.

The leaded apron revisited: does it reduce gonadal radiation dose in dental radiology

International Nuclear Information System (INIS)

Wood, R.E.; Harris, A.M.; van der Merwe, E.J.; Nortje, C.J.

1991-01-01

A tissue-equivalent anthropomorphic human phantom was used with a lithium fluoride thermoluminescent dosimetry system to evaluate the radiation absorbed dose to the ovarian and testicular region during dental radiologic procedures. Measurements were made with and without personal lead shielding devices consisting of thyroid collar and apron of 0.25 mm lead thickness equivalence. The radiation absorbed dose with or without lead shielding did not differ significantly from control dosimeters in vertex occlusal and periapical views (p greater than 0.05). Personal lead shielding devices did reduce gonadal dose in the case of accidental exposure (p less than 0.05). A leaded apron of 0.25 mm lead thickness equivalent was permeable to radiation in direct exposure testing

Potential radiation doses from 1994 Hanford Operations

Energy Technology Data Exchange (ETDEWEB)

Soldat, J.K.; Antonio, E.J.

1995-06-01

This section of the 1994 Hanford Site Environmental Report summarizes the potential radiation doses to the public from releases originating at the Hanford Site. Members of the public are potentially exposed to low-levels of radiation from these effluents through a variety of pathways. The potential radiation doses to the public were calculated for the hypothetical MEI and for the general public residing within 80 km (50 mi) of the Hanford Site.

Potential radiation doses from 1994 Hanford Operations

International Nuclear Information System (INIS)

Soldat, J.K.; Antonio, E.J.

1995-01-01

This section of the 1994 Hanford Site Environmental Report summarizes the potential radiation doses to the public from releases originating at the Hanford Site. Members of the public are potentially exposed to low-levels of radiation from these effluents through a variety of pathways. The potential radiation doses to the public were calculated for the hypothetical MEI and for the general public residing within 80 km (50 mi) of the Hanford Site

Biological evidence of low ionizing radiation doses

International Nuclear Information System (INIS)

Mirsch, Johanna

2017-01-01

Throughout life, every person is constantly exposed to different types of ionising radiation, without even noticing the exposure. The mean radiation exposure for people living in Germany amounts to approximately 4 mSv per year and encompasses the exposure from natural and man-made sources. The risks associated with exposure to low doses of radiation are still the subject of intense and highly controversial discussions, emphasizing the social relevance of studies investigating the effects of low radiation doses. In this thesis, DNA double-strand breaks (DSBs) were analyzed within three projects covering different aspects. DSBs are among the most hazardous DNA lesions induced by ionizing radiation, because this type of damage can easily lead to the loss of genetic information. Consequently, the DSB presents a high risk for the genetic integrity of the cell. In the first project, extensive results uncovered the track structure of charged particles in a biological model tissue. This provided the first biological data that could be used for comparison with data that were measured or predicted using theoretical physical dosimetry methods and mathematical simulations. Charged particles contribute significantly to the natural radiation exposure and are used increasingly in cancer radiotherapy because they are more efficient in tumor cell killing than X- or γ-rays. The difference in the biological effects of high energy charged particles compared with X- or γ-rays is largely determined by the spatial distribution of their energy deposition and the track structure inducing a three-dimensional damage pattern in living cells. This damage pattern consists of cells directly hit by the particle receiving a high dose and neighboring cells not directly hit by primary particles but exposed to far-reaching secondary electrons (δ-electrons). These cells receive a much lower dose deposition in the order of a few mGy. The radial dose distribution of single particle tracks was

Monitoring and control of occupational radiation exposure in Switzerland

International Nuclear Information System (INIS)

Moser, M.

1997-01-01

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

The Dose Response Relationship for Radiation Carcinogenesis

Science.gov (United States)

Hall, Eric

2008-03-01

Recent surveys show that the collective population radiation dose from medical procedures in the U.S. has increased by 750% in the past two decades. It would be impossible to imagine the practice of medicine today without diagnostic and therapeutic radiology, but nevertheless the widespread and rapidly increasing use of a modality which is a known human carcinogen is a cause for concern. To assess the magnitude of the problem it is necessary to establish the shape of the dose response relationship for radiation carcinogenesis. Information on radiation carcinogenesis comes from the A-bomb survivors, from occupationally exposed individuals and from radiotherapy patients. The A-bomb survivor data indicates a linear relationship between dose and the risk of solid cancers up to a dose of about 2.5 Sv. The lowest dose at which there is a significant excess cancer risk is debatable, but it would appear to be between 40 and 100 mSv. Data from the occupation exposure of nuclear workers shows an excess cancer risk at an average dose of 19.4 mSv. At the other end of the dose scale, data on second cancers in radiotherapy patients indicates that cancer risk does not continue to rise as a linear function of dose, but tends towards a plateau of 40 to 60 Gy, delivered in a fractionated regime. These data can be used to estimate the impact of diagnostic radiology at the low dose end of the dose response relationship, and the impact of new radiotherapy modalities at the high end of the dose response relationship. In the case of diagnostic radiology about 90% of the collective population dose comes from procedures (principally CT scans) which involve doses at which there is credible evidence of an excess cancer incidence. While the risk to the individual is small and justified in a symptomatic patient, the same is not true of some screening procedures is asymptomatic individuals, and in any case the huge number of procedures must add up to a potential public health problem. In the

Low doses effects and gamma radiations low dose rates

International Nuclear Information System (INIS)

Averbeck, D.

1999-01-01

This expose wishes for bringing some definitions and base facts relative to the problematics of low doses effects and low dose rates effects. It shows some already used methods and some actual experimental approaches by focusing on the effects of ionizing radiations with a low linear energy transfer. (N.C.)

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

International Nuclear Information System (INIS)

Eleveld, H.; Pruppers, M.

2002-01-01

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

Tumour induction by small doses of ionised radiation

International Nuclear Information System (INIS)

Putten, L.M. van

1980-01-01

The effect of low doses of ionised radiation on tumour induction in animals is discussed. It is hypothesised that high doses of radiation can strongly advance tumour induction from the combination of a stimulated cell growth, as a reaction to massive cell killing, and damage to DNA in the cell nuclei. This effect has a limit below which the radiation dose causes a non-significant amount of dead cells. However in animals where through other reasons, a chronic growth stimulation already exists, only one effect, the damage of DNA, is necessary to induce tumours. A linear dose effect without a threshold level applies in these cases. Applying this hypothesis to man indicates that calculating low dose effects by linear extrapolation of high dose effects is nothing more than a reasonable approximation. (C.F.)

Spiral CT and radiation dose

International Nuclear Information System (INIS)

Imhof, H.; Schibany, N.; Ba-Ssalamah, A.; Czerny, C.; Hojreh, A.; Kainberger, F.; Krestan, C.; Kudler, H.; Noebauer, I.; Nowotny, R.

2003-01-01

Recent studies in the USA and Europe state that computed tomography (CT) scans compromise only 3-5% of all radiological exams, but they contribute 35-45% of total radiation dose to the patient population. These studies lead to concern by several public authorities. Basis of CT-dose measurements is the computed tomography dose index (CTDI), which was established 1981. Nowadays there are several modifications of the CTDI values, which may lead to confusion. It is suggested to use the standardized CTDI-100 w. value together with the dose length product in all CT-examinations. These values should be printed on all CT-images and allows an evaluation of the individualized patient dose. Nowadays, radiologist's aim must be to work at the lowest maximal diagnostic acceptable signal to noise ratio. To decrease radiation dose radiologist should use low kV and mA, but high pitches. Newly developed CT-dose-reduction soft-wares and filters should be installed in all CT-machines. We should critically compare the average dose used for a specific examination with the reference dose used in this country and/or Europe. Greater differences should caution the radiologist. Finally, we as radiologists must check very carefully all indications and recommend alternative imaging methods. But we have also to teach our customers--patients and medical doctors who are non-radiologists--that a 'good' image is not that which show all possible information, but that which visualize 'only' the diagnostic necessary information

The Study of External Radiation Dose for Radiation Worker at PRSG-BATAN Serpong

International Nuclear Information System (INIS)

Sunarningsih; Mashudi; A Lilik W; Yosep S

2012-01-01

The study of External radiation dose for radiation worker at PRSG-BATAN Serpong has been carried out. The sample is taken from the System Reactor division (BSR), Operation Reactor division, (BOR) Safety division UPN, UJM and head of PRSG by setting Thermoluminescence Dosemeter (TLD) on the chest, then is detected by a tool TLD reader model 6600. The aim of this study is to evaluate the occupational exposure dose that has been accepted by the radiation worker for the last five years. The result in average doses at BSR is 0,99 mSv, BOR is 3,27 mSv, at BK is 0,69 mSv and UPN + UJM + head of PRSG is 0,03 mSv. The result highest doses at BSR is 6,58 mSv, BOR is 28,94 mSv, BK is 4,24 mSv, and UPN UJM Head of PRSG is 0,52 mSv. Dose interval radiation worker at PRSG BATAN ttd - 28,98 mSv. To overall the external personal dose acceptant for radiation worker at PRSG BATAN one below maximum permissible dose acceptant that allowed by BAPETEN, that is 20 mSv in average every year during five years. (author)

Epigenomic Adaptation to Low Dose Radiation

Energy Technology Data Exchange (ETDEWEB)

Gould, Michael N. [Univ. of Wisconsin, Madison, WI (United States)

2015-06-30

The overall hypothesis of this grant application is that the adaptive responses elicited by low dose ionizing radiation (LDIR) result in part from heritable DNA methylation changes in the epigenome. In the final budget period at the University of Wisconsin-Madison, we will specifically address this hypothesis by determining if the epigenetically labile, differentially methylated regions (DMRs) that regulate parental-specific expression of imprinted genes are deregulated in agouti mice by low dose radiation exposure during gestation. This information is particularly important to ascertain given the 1) increased human exposure to medical sources of radiation; 2) increased number of people predicted to live and work in space; and 3) enhanced citizen concern about radiation exposure from nuclear power plant accidents and terrorist ‘dirty bombs.’

Radiation dose measurement in gastrointestinal studies

International Nuclear Information System (INIS)

Sulieman, A.; Elzaki, M.; Kappas, C.; Theodorou, K.

2011-01-01

Barium studies investigations (barium swallow, barium meal and barium enema) are the basic routine radiological examination, where barium sulphate suspension is introduced to enhance image contrast of gastrointestinal tracts. The aim of this study was to quantify the patients' radiation doses during barium studies and to estimate the organ equivalent dose and effective dose with those procedures. A total of 33 investigations of barium studies were measured by using thermoluminescence dosemeters. The result showed that the patient entrance surface doses were 12.6±10, 44.5±49 and 35.7±50 mGy for barium swallow, barium meal, follow through and enema, respectively. Effective doses were 0.2, 0.35 and 1.4 mSv per procedure for barium swallow, meal and enema respectively. Radiation doses were comparable with the previous studies. A written protocol for each procedure will reduce the inter-operator variations and will help to reduce unnecessary exposure. (authors)

Cumulative radiation dose of multiple trauma patients during their hospitalization

International Nuclear Information System (INIS)

Wang Zhikang; Sun Jianzhong; Zhao Zudan

2012-01-01

Objective: To study the cumulative radiation dose of multiple trauma patients during their hospitalization and to analyze the dose influence factors. Methods: The DLP for CT and DR were retrospectively collected from the patients during June, 2009 and April, 2011 at a university affiliated hospital. The cumulative radiation doses were calculated by summing typical effective doses of the anatomic regions scanned. Results: The cumulative radiation doses of 113 patients were collected. The maximum,minimum and the mean values of cumulative effective doses were 153.3, 16.48 mSv and (52.3 ± 26.6) mSv. Conclusions: Multiple trauma patients have high cumulative radiation exposure. Therefore, the management of cumulative radiation doses should be enhanced. To establish the individualized radiation exposure archives will be helpful for the clinicians and technicians to make decision whether to image again and how to select the imaging parameters. (authors)

Radiation doses from radon and progeny in Irish houses

International Nuclear Information System (INIS)

McLaughlin, J.P.

1985-08-01

In the United Kingdom, the estimated average annual effective dose equivalent to members of the public from all sources is 2.4 mSv (240 mrem). 40% of this dose is contributed by exposure to radon, and it is not unreasonable to assume that the situation in Ireland is very similar. During 1982-84 a preliminary study of radon and penetrating radiation on 300 Irish houses showed seasonally averaged indoor radon concentrations in the range 3 Bq/m 3 of air to 700 bq/m 3 , with a median value of about 40 bq/m 3 . A national survey of indoor radon has now been undertaken; 3000 households, randomly selected from the electoral register are to be monitored and the result correlated with energy conservation practices. The final part of this document deals with the regulatory aspects of radon control and reviews the practices for reduction of indoor radon daughter doses presently in hand in Scandinavia. An appendix of radiation units and terms is also given

Radiation doses from computed tomography in Australia

International Nuclear Information System (INIS)

Thomson, J.E.M.; Tingey, D.R.C.

1997-11-01

Recent surveys in various countries have shown that computed tomography (CT) is a significant and growing contributor to the radiation dose from diagnostic radiology. Australia, with 332 CT scanners (18 per million people), is well endowed with CT equipment compared to European countries (6 to 13 per million people). Only Japan, with 8500 units (78 per million people), has a significantly higher proportion of CT scanners. In view of this, a survey of CT facilities, frequency of examinations, techniques and patient doses has been performed in Australia. It is estimated that there are 1 million CT examinations in Australia each year, resulting in a collective effective dose of 7000 Sv and a per caput dose of 0.39 mSv. This per caput dose is much larger than found in earlier studies in the UK and New Zealand but is less than 0.48 mSv in Japan. Using the ICRP risk factors, radiation doses from CT could be inducing about 280 fatal cancers per year in Australia. CT is therefore a significant, if not the major, single contributor to radiation doses and possible risk from diagnostic radiology. (authors)

Scatter radiation dose at height of the lens and image quality in interventional cardiology

International Nuclear Information System (INIS)

Leguees, Fernando A. Leyton

2016-01-01

Cardiologist and other staff members receive high doses of scattered radiation. Cases of radiation-induced cataract among cardiology professionals have been reported in studies, estimates for the dose to eye lens ranged from 450 to 900 mSv per year (without ceiling suspended screen), over several years. Recent surveys regarding high prevalence of lens changes likely induced by radiation exposure suggest an urgent need for improved radiation safety and training, use of eye protection during catheterization procedures, and improved occupational dosimetry. In view of the evidence of radiation injuries, the ICRP recommends limiting the radiation dose to the lens to 20 mSv per year for occupational exposure. A system for optimizing the radiation exposure is the measurement of entrance surface air kerma (K a,e ) and kerma-area product (P KA ) for patient and scattered dose or dose rate at the position for the staff, under clinical working conditions using phantoms and defined technical factors. Correlating K a,e and P KA with the scatter dose, applying the attenuation factors protective devices can enable estimation of the lens doses for operators. The purpose of this work is: to study the possibility of establishing a procedure which is useful for scientific societies and the regulatory authority in the prevention and control of IOE dose and to control and improve the quality of procedures in interventional cardiology as an initiative to raise awareness and optimization of radiological protection. Measurements were taken in different cardiac laboratories. Clinical working conditions were reproduced during the experiments for the different hemodynamic angiographic projections and operating modes used in fluoroscopy and cine. A first K a,e rate reference proposal for the characterization of angiography for the different acquisition modes were 16; 35; 40 and 220 (mGy/min), respectively. Considering the typical PKA values to patient in interventional cardiology procedures

A trial of radiation dose prescription based on dose-cell survival formula

International Nuclear Information System (INIS)

Allen, E.P.

1984-01-01

Radiation treatment has been prescribed for 379 basal cell carcinomata on the basis of a selected equivalent single dose derived from the standard multi-target dose-cell survival formula using values of m = 2 and Do = 130 rads for orthovoltage x-rays. The results suggest that the approach provides a flexible and acceptable alternative to prescription by total dose or by Nominal Standard Dose. It is submitted that Total Dose is an inadequate expression of radiobiological effects: that the NSD and related systems are valuable measures of the ability of normal tissues to recover from radiation damage: and that a parallel measure of the degree of tumour depopulation has become necessary to allow further progress in alternative fractionation schedules

Radiation dose reduction in chest CT—Review of available options

International Nuclear Information System (INIS)

Kubo, Takeshi; Ohno, Yoshiharu; Kauczor, Hans Ulrich; Hatabu, Hiroto

2014-01-01

Highlights: • The present status of proliferating CT examinations was presented. • Technical improvements of CT scanners for radiation dose reduction were reviewed. • Advantage and disadvantage of methods for CT radiation dose reduction were discussed. • Evidences for safety of CT radiation dose reduction were reviewed. - Abstract: Computed tomography currently accounts for the majority of radiation exposure related to medical imaging. Although technological improvement of CT scanners has reduced the radiation dose of individual examinations, the benefit was overshadowed by the rapid increase in the number of CT examinations. Radiation exposure from CT examination should be kept as low as reasonably possible for patient safety. Measures to avoid inappropriate CT examinations are needed. Principles and information on radiation dose reduction in chest CT are reviewed in this article. The reduction of tube current and tube potential are the mainstays of dose reduction methods. Study results indicate that routine protocols with reduced tube current are feasible with diagnostic results comparable to conventional standard dose protocols. Tube current adjustment is facilitated by the advent of automatic tube current modulation systems by setting the appropriate image quality level for the purpose of the examination. Tube potential reduction is an effective method for CT pulmonary angiography. Tube potential reduction often requires higher tube current for satisfactory image quality, but may still contribute to significant radiation dose reduction. Use of lower tube potential also has considerable advantage for smaller patients. Improvement in image production, especially the introduction of iterative reconstruction methods, is expected to lower radiation dose significantly. Radiation dose reduction in CT is a multifaceted issue. Understanding these aspects leads to an optimal solution for various indications of chest CT

Radiation dose reduction in chest CT—Review of available options

Energy Technology Data Exchange (ETDEWEB)

Kubo, Takeshi, E-mail: tkubo@kuhpkyoto-u.ac.jp [Department of Diagnostic Imaging and Nuclear Medicine, Kyoto University Graduate School of Medicine, 54 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507 (Japan); Ohno, Yoshiharu, E-mail: yosirad@kobe-u.ac.jp [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2, Kusunoki-cho, Chuo-ku, Kobe 650-0017 (Japan); Kauczor, Hans Ulrich, E-mail: hu.kauczor@med.uni-heidelberg.de [Diagnostic and Interventional Radiology, University Clinic Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg (Germany); Hatabu, Hiroto, E-mail: hhatabu@partners.org [Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)

2014-10-15

Highlights: • The present status of proliferating CT examinations was presented. • Technical improvements of CT scanners for radiation dose reduction were reviewed. • Advantage and disadvantage of methods for CT radiation dose reduction were discussed. • Evidences for safety of CT radiation dose reduction were reviewed. - Abstract: Computed tomography currently accounts for the majority of radiation exposure related to medical imaging. Although technological improvement of CT scanners has reduced the radiation dose of individual examinations, the benefit was overshadowed by the rapid increase in the number of CT examinations. Radiation exposure from CT examination should be kept as low as reasonably possible for patient safety. Measures to avoid inappropriate CT examinations are needed. Principles and information on radiation dose reduction in chest CT are reviewed in this article. The reduction of tube current and tube potential are the mainstays of dose reduction methods. Study results indicate that routine protocols with reduced tube current are feasible with diagnostic results comparable to conventional standard dose protocols. Tube current adjustment is facilitated by the advent of automatic tube current modulation systems by setting the appropriate image quality level for the purpose of the examination. Tube potential reduction is an effective method for CT pulmonary angiography. Tube potential reduction often requires higher tube current for satisfactory image quality, but may still contribute to significant radiation dose reduction. Use of lower tube potential also has considerable advantage for smaller patients. Improvement in image production, especially the introduction of iterative reconstruction methods, is expected to lower radiation dose significantly. Radiation dose reduction in CT is a multifaceted issue. Understanding these aspects leads to an optimal solution for various indications of chest CT.

Radiation Dose Contribution To The Worker Health Level At Serpong Area

International Nuclear Information System (INIS)

Yuwono, Indro

2000-01-01

Analysis of internal and external radiation doses received for radiation and non-radiation workers of P2TBDU have been done. In the period of 1997/1998 and 1998/1999 there were no significant increasing level of radiation doses received that was 0.55 mSv and highest received radiation dose was 2.66% from dose limit value. Increasing of healthy difference on the same period was 5.76%. Increasing of healthy difference no cause by increasing of radiation dose received but maybe the food consumption design

The effect of radiation dose on mouse skeletal muscle remodeling

International Nuclear Information System (INIS)

Hardee, Justin P.; Puppa, Melissa J.; Fix, Dennis K.; Gao, Song; Hetzler, Kimbell L.; Bateman, Ted A.; Carson, James A.

2014-01-01

The purpose of this study was to determine the effect of two clinically relevant radiation doses on the susceptibility of mouse skeletal muscle to remodeling. Alterations in muscle morphology and regulatory signaling were examined in tibialis anterior and gastrocnemius muscles after radiation doses that differed in total biological effective dose (BED). Female C57BL/6 (8-wk) mice were randomly assigned to non-irradiated control, four fractionated doses of 4 Gy (4x4 Gy; BED 37 Gy), or a single 16 Gy dose (16 Gy; BED 100 Gy). Mice were sacrificed 2 weeks after the initial radiation exposure. The 16 Gy, but not 4x4 Gy, decreased total muscle protein and RNA content. Related to muscle regeneration, both 16 Gy and 4x4 Gy increased the incidence of central nuclei containing myofibers, but only 16 Gy increased the extracellular matrix volume. However, only 4x4 Gy increased muscle 4-hydroxynonenal expression. While both 16 Gy and 4x4 Gy decreased IIB myofiber mean cross-sectional area (CSA), only 16 Gy decreased IIA myofiber CSA. 16 Gy increased the incidence of small diameter IIA and IIB myofibers, while 4x4 Gy only increased the incidence of small diameter IIB myofibers. Both treatments decreased the frequency and CSA of low succinate dehydrogenase activity (SDH) fibers. Only 16 Gy increased the incidence of small diameter myofibers having high SDH activity. Neither treatment altered muscle signaling related to protein turnover or oxidative metabolism. Collectively, these results demonstrate that radiation dose differentially affects muscle remodeling, and these effects appear to be related to fiber type and oxidative metabolism

Factors affecting radiation doses from dedicated rail transport of spent reactor fuel

International Nuclear Information System (INIS)

Martin, J.E.

1988-01-01

This paper reports there are two exposure control concerns associated with the shipment of spent reactor fuel in dedicated trains -- compliance with transportation regulations for maximum allowable radiation levels, and minimizing the dose received by the general public. This article examines the methods used to calculate the dose equivalent rates alongside stationary (transport regulations) and moving trains (public exposure) of various lengths. The factors examined include the source term, the effect of overlapping radiation fields, the speed of the train, and the location of the population relative to the train. Trains made up of series of cars that individually meet transport regulations can, as a whole, exceed transport vehicle dose equivalent rate limits by up to 23% due to overlapping radiation fields. For moving trains and the worst case analyzed -- a person located 20 feet from the tracks and a train speed of 5 mph --- 141 rail cars would have to pass by to deliver a dose equivalent of 1 mrem

PET radiation exposure control for nurses

International Nuclear Information System (INIS)

Kawabata, Yumiko; Kikuta, Daisuke; Anzai, Taku

2005-01-01

Recently, the number of clinical PET centers is increasing all over Japan. For this reason, the monitoring and control of radiation exposure of employees, especially nurses, in PET-dedicated clinics and institutions are becoming very important issues for their health. We measured the radiation exposure doses of the nurses working at Nishidai Diagnostic Imaging Center, and analyzed the exposure data obtained from them. The exposure doses of the nurses were found to be 4.8 to 7.1 mSv between April 2003 and March 2004. We found that the nurses were mostly exposed to radiation when they had to have contact with patients received an FDG injection or they had trouble with the FDG automatic injection system. To keep radiation exposure of nurses to a minimum we reconfirmed that a proper application of the three principles of protection against radiation exposure was vital. (author)

Modern Radiation Therapy for Hodgkin Lymphoma: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group (ILROG)

International Nuclear Information System (INIS)

Specht, Lena; Yahalom, Joachim; Illidge, Tim; Berthelsen, Anne Kiil; Constine, Louis S.; Eich, Hans Theodor; Girinsky, Theodore; Hoppe, Richard T.; Mauch, Peter; Mikhaeel, N. George; Ng, Andrea

2014-01-01

Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solely on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the

Influence of Residual Tumor Volume and Radiation Dose Coverage in Outcomes for Clival Chordoma

Energy Technology Data Exchange (ETDEWEB)

McDonald, Mark W., E-mail: markmcdonaldmd@gmail.com [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana (United States); Indiana University Health Proton Therapy Center, Bloomington, Indiana (United States); Linton, Okechukwu R. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana (United States); Moore, Michael G.; Ting, Jonathan Y. [Department of Otolaryngology, Head and Neck Surgery, Indiana University School of Medicine, Indianapolis, Indiana (United States); Cohen-Gadol, Aaron A.; Shah, Mitesh V. [Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana (United States); Goodman Campbell Brain and Spine, Indianapolis, Indiana (United States)

2016-05-01

Purpose: The purpose of this study was to evaluate factors associated with tumor control in clival chordomas. Methods and Materials: A retrospective review of 39 patients treated with surgery and proton therapy for clival chordomas between 2004 and 2014 was performed. The median prescribed dose was 77.4 Gy (relative biological effectiveness [RBE]); range was 70.2-79.2 Gy (RBE). Minimum and median doses to gross tumor volume (GTV), radiation dose received by 1 cm{sup 3} of GTV (D1cm{sup 3}), and the equivalent uniform dose were calculated. Receiver operating characteristics curves evaluated the predictive sensitivity and specificity for local failure of potential cutpoint values for GTV and D1cm{sup 3}. Results: After a median follow-up of 51 months, the 5-year estimate of local control (LC) was 69.6% (95% confidence interval [CI] 50.0%-89.2%), and overall survival (OS) was 81.4% (95% CI: 65.3%-97.5%). Tumor histology, GTV at the time of radiation, and prescribed radiation dose were significantly associated with local control on multivariate analysis, whereas D1cm{sup 3} was associated with overall survival. Compared to those patients whose conditions remained controlled, patients experiencing tumor failure had statistically significant larger GTVs and lower D1cm{sup 3}, and prescribed and median doses to GTV. A subset of 21 patients with GTV of ≤20 cm{sup 3} and D1cm{sup 3} of >67 Gy (RBE) had a median follow-up of 47 months. The 5-year estimate of local control in this subset was 81.1% (95% CI: 61.7%-100%; P=.004, overall comparison by GTV ≤20 cm{sup 3} stratified by D1cm{sup 3}). A D1cm{sup 3} of 74.5 Gy (RBE) had 80% sensitivity for local control and 60% specificity, whereas a GTV of 9.3 cm{sup 3} had 80% sensitivity for local control and 66.7% specificity. Conclusions: Local control of clival chordomas was associated with both smaller size of residual tumor and more complete high-dose coverage of residual tumor. Multidisciplinary care should seek

Ultraviolet Radiation Dose National Standard of México

Science.gov (United States)

Cardoso, R.; Rosas, E.

2006-09-01

We present the Ultraviolet (UV) Radiation Dose National Standard for México. The establishment of this measurement reference at Centro Nacional de Metrología (CENAM) eliminates the need of contacting foreign suppliers in the search for traceability towards the SI units when calibrating instruments at 365 nm. Further more, the UV Radiation Dose National Standard constitutes a highly accurate and reliable source for the UV radiation dose measurements performed in medical and cosmetic treatments as in the the food and pharmaceutics disinfection processes, among other.

Radiation safety program in a high dose rate brachytherapy facility

International Nuclear Information System (INIS)

Rodriguez, L.V.; Hermoso, T.M.; Solis, R.C.

2001-01-01

The use of remote afterloading equipment has been developed to improve radiation safety in the delivery of treatment in brachytherapy. Several accidents, however, have been reported involving high dose-rate brachytherapy system. These events, together with the desire to address the concerns of radiation workers, and the anticipated adoption of the International Basic Safety Standards for Protection Against Ionizing Radiation (IAEA, 1996), led to the development of the radiation safety program at the Department of Radiotherapy, Jose R. Reyes Memorial Medical Center and at the Division of Radiation Oncology, St. Luke's Medical Center. The radiation safety program covers five major aspects: quality control/quality assurance, radiation monitoring, preventive maintenance, administrative measures and quality audit. Measures for evaluation of effectiveness of the program include decreased unnecessary exposures of patients and staff, improved accuracy in treatment delivery and increased department efficiency due to the development of staff vigilance and decreased anxiety. The success in the implementation required the participation and cooperation of all the personnel involved in the procedures and strong management support. This paper will discuss the radiation safety program for a high dose rate brachytherapy facility developed at these two institutes which may serve as a guideline for other hospitals intending to install a similar facility. (author)

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

International Nuclear Information System (INIS)

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

1975-01-01

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

Survey of radiation doses and health effects in medical diagnostic X-ray workers in China

International Nuclear Information System (INIS)

Wang Jixian; Zhang Liangan; Liu Jinzhong; Zhang Jingyuan

1984-01-01

The results of a nationwide survey of radiation doses and health effects in 26983 medical diagnostic X-ray workers in 28 provinces of China were reported. The control group was composed of 25785 non-X-ray medical workers in the same hospitals where the investigated X-ray workers worked. Of the radiological workers surveyed 75.3% received cumulative radiation doses below 50 mGy, only 2.7% received doses greater than 500 mGy, the average cumulative dose being 45.0 mGy. The average length of service was 11 years. The main radiation effects relating to radiation doses were the increase of frequencies of both chromosomal aberrations and micronuclei in peripheral blood lymphocytes, which were 0.362% and 0.0358% in the irradiated group, and 0.122% and 0.0138% in the control group, respectively. The incidence and mortality rate of leukemias increased significantly in the irradiated group. The incidence and standardized incidence of leukemias were 9.61 . 10 -5 and 9.67 . 10 -5 in the irradiated group and 2.74 . 10 -5 and 2.77 . 10 -5 in the control group. The leukemia mortality rates in the two groups were 8.60 . 10 -5 and 1.24 . 10 -5 respectively, and the standardized mortality rates were 8.60 . 10 -5 and 1.27 . 10 -5 respectively. (Author)

Dose measurements in controlled area of TRIGA IPR-R1 reactor

International Nuclear Information System (INIS)

Alvarenga, F.L.; Junior, F.M.

2005-01-01

The workers doses in exposure areas to the radiation are so important for a Radioprotection Quality Program, as well as to guarantee the workers safety. For that it is necessary to raise the doses in the radiation areas, to obtain the accumulated dose in certain procedures for detailed studies. Several risings were accomplished to obtain the radiation levels in the areas where the workers are exposed due the operation of a research nuclear reactor and in the radioisotopes manipulation laboratories of a nuclear institute. The radiation levels and doses can be observed through graphs in the dependences of the Controlled Area 1 (AC-1) and the Reactor Laboratory. Those limits are in according of the CNEN-NE-3.01 work limits rules. The conclusion of the work allowed to demonstrate that the Laboratory of the Reactor and AC-1, have booth an effective radiological program with efficient operational practices that contributes with low doses to the workers

The effect of different adaptation strengths on image quality and radiation dose using Siemens care dose 4D

International Nuclear Information System (INIS)

Soederberg, M.; Gunnarsson, M.

2010-01-01

The purpose of this study was to evaluate the effect of different choices of adaptation strengths on image quality and radiation exposure to the patient with Siemens automatic exposure control system called CARE Dose 4D. An anthropomorphic chest phantom was used to simulate the patient and computed tomography scans were performed with a Siemens SOMATOM Sensation 16 and 64. Owing to adaptation strengths, a considerable reduction (26.6-51.5 % and 27.5-49.5% for Sensation 16 and Sensation 64, respectively) in the radiation dose was found when compared with using a fixed tube current. There was a substantial difference in the image quality (image noise) between the adaptation strengths. Independent of selected adaptation strengths, the level of image noise throughout the chest phantom increased when CARE Dose 4D was used (p < 0.0001). We conclude that the adaptation strengths can be used to obtain user-specified modifications to image quality or radiation exposure to the patient. (authors)

Application of maximum values for radiation exposure and principles for the calculation of radiation doses

International Nuclear Information System (INIS)

2007-08-01

The guide presents the definitions of equivalent dose and effective dose, the principles for calculating these doses, and instructions for applying their maximum values. The limits (Annual Limit on Intake and Derived Air Concentration) derived from dose limits are also presented for the purpose of monitoring exposure to internal radiation. The calculation of radiation doses caused to a patient from medical research and treatment involving exposure to ionizing radiation is beyond the scope of this ST Guide

CARCINOGENIC EFFECTS OF LOW DOSES OF IONIZING RADIATION

Science.gov (United States)

Carcinogenic Effects of Low Doses of Ionizing RadiationR Julian Preston, Environmental Carcinogenesis Division, NHEERL, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711The form of the dose-response curve for radiation-induced cancers, particu...

Biological effects of low doses of ionizing radiation

International Nuclear Information System (INIS)

Gonzalez, A.J.

1994-01-01

Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

The development of wireless radiation dose monitoring using smart phone

Energy Technology Data Exchange (ETDEWEB)

Lee, Jin Woo; Jeong, Gyo Seong; Lee, Yun Jong [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Kim, Chong Yeal [Chonbuk National University, Jeonju (Korea, Republic of); Lim, Chai Wan [REMTECH, Seoul (Korea, Republic of)

2016-11-15

Radiation workers at a nuclear facility or radiation working area should hold personal dosimeters. some types of dosimeters have functions to generate audible or visible alarms to radiation workers. However, such devices used in radiation fields these days have no functions to communicate with other equipment or the responsible personnel. our project aims at the development of a remote wireless radiation dose monitoring system that can be utilized to monitor the radiation dose for radiation workers and to notify the radiation protection manager of the dose information in real time. We use a commercial survey meter for personal radiation measurement and a smart phone for a mobile wireless communication tool and a Beacon for position detection of radiation workers using Blue tooth communication. In this report, the developed wireless dose monitoring of cellular phone is introduced.

Influence of radiation dose on positive surgical margins in women undergoing breast conservation therapy

International Nuclear Information System (INIS)

DiBiase, Steven J.; Komarnicky, Lydia T.; Heron, Dwight E.; Schwartz, Gordon F.; Mansfield, Carl M.

2002-01-01

Purpose: Positive surgical margins adversely influence local tumor control in breast conservation therapy (BCT). However, reports have conflicted regarding whether an increased radiation dose can overcome this poor prognostic factor. In this study, we evaluated the influence of an increased radiation dose on tumor control in women with positive surgical margins undergoing BCT. Methods and Materials: Between 1978 and 1994, 733 women with pathologic Stage I-II breast cancer and known surgical margin status were treated at Thomas Jefferson University Hospital with BCT. Of these 733 patients, 641 women had a minimal tumor bed dose of 60 Gy and had documentation of their margin status; 509 had negative surgical margins, and 132 had positive surgical margins before definitive radiotherapy. Complete gross excision of the tumor and axillary lymph node sampling was obtained in all patients. The median radiation dose to the primary site was 65.0 Gy (range 60-76). Of the women with positive margins (n=132), the influence of higher doses of radiotherapy was evaluated. The median follow-up time was 52 months. Results: The local tumor control rate for patients with negative margins at 5 and 10 years was 94% and 88%, respectively, compared with 85% and 67%, respectively, for those women with positive margins (p=0.001). The disease-free survival rate for the negative margin group at 5 and 10 years was 91% and 82%, respectively, compared with 76% and 71%, respectively, for the positive margin group (p = 0.001). The overall survival rate of women with negative margins at 5 and 10 years was 95% and 90%, respectively. By comparison, for women with positive surgical margins, the overall survival rate at 5 and 10 years was 86% and 79%, respectively (p=0.008). A comparison of the positive and negative margin groups revealed that an increased radiation dose (whether entered as a dichotomous or a continuous variable) >65.0 Gy did not improve local tumor control (p=0.776). On Cox

Radiation doses in pediatric radiology: influence of regulations and standards

International Nuclear Information System (INIS)

Suleiman, O.H.

2004-01-01

The benefits of X-ray examinations contribute to the quality of modern medicine; however the risk of using X-rays, a carcinogen, has always been a concern. This concern is heightened for pediatric patients, who have a much greater sensitivity to the carcinogenic effects of radiation than adults. The principle of as low as reasonably achievable, or ALARA, is essential for minimizing the radiation dose patients receive, especially for pediatric patients. In order to keep radiation doses ALARA, one must know the dose patients receive. The determination of radiation dose in a standard way is therefore necessary so that these doses can be compared with practice, and for meaningful comparison against voluntary standards. In extreme situations, where public health needs may require mandatory standards, or regulations, the quantitative measurement and calculation of radiation dose becomes essential. How some radiation dose metrics and standards have evolved, including the value of different metrics such as entrance air kerma, organ dose, and effective dose will be presented. Recent pediatric X-ray studies, whether or not dedicated pediatric equipment is necessary, and recent initiatives by the Food and Drug Administration for pediatric population will be discussed. (orig.)

International Conference on Low Doses of Ionising Radiation

International Nuclear Information System (INIS)

McEwan, A.C.

1998-01-01

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)

Biological radiation dose estimation by chromosomal aberrations analysis in human peripheral blood (dose- effect curve)

International Nuclear Information System (INIS)

Al Achkar, W.

2002-01-01

In order to draw a dose-effect curve, blood from eight healthy people were studied. Samples were irradiated in tubes with 0.15-2.5 gray of gamma ray.Irradiated and control samples were incubated for cell cultures. Chromosomal aberrations from 67888 metaphases were scored. Curves from the total number of dicentrics, dicentrics+ rings and total numbers of breaks were drawn. The yield of chromosome aberrations is related to the dose used. These curves give a quick useful estimation of the accidentally radiation exposure. (author)

Tolerance doses of cutaneous and mucosal tissues in ring-necked parakeets (Psittacula krameri) for external beam megavoltage radiation.

Science.gov (United States)

Barron, Heather W; Roberts, Royce E; Latimer, Kenneth S; Hernandez-Divers, Stephen; Northrup, Nicole C

2009-03-01

Currently used dosages for external-beam megavoltage radiation therapy in birds have been extrapolated from mammalian patients and often appear to provide inadequate doses of radiation for effective tumor control. To determine the tolerance doses of cutaneous and mucosal tissues of normal birds in order to provide more effective radiation treatment for tumors that have been shown to be radiation responsive in other species, ingluvial mucosa and the skin over the ingluvies of 9 ring-necked parakeets (Psittacula krameri) were irradiated in 4-Gy fractions to a total dose of either 48, 60, or 72 Gy using an isocentric cobalt-60 teletherapy unit. Minimal radiation-induced epidermal changes were present in the high-dose group histologically. Neither dose-related acute nor chronic radiation effects could be detected in any group grossly in cutaneous or mucosal tissue over a 9-month period. Radiation doses of 72 Gy in 4-Gy fractions were well tolerated in the small number of ring-necked parakeets in this initial tolerance dose study.

Study on radiation dose in the medical image data display method-focus on the DICOM standard

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung Su [Dept. of Radio-technology, Health Welfare, Wonkwang Health Science University, Iksan (Korea, Republic of)

2015-12-15

DICOM (Digital Imaging and Communications in Medicine) standards are generally introduced as de facto and de jure standards in modern medical imaging devices to store and to transmit medical image information. DICOM Dose Structured Report (DICOM dose SR) is implemented to report radiation exposure information in image acquiring process. and DIOCM Modality Performed Procedure Step (DICOM MPPS) is also partly used to report this exposure with the information in its DICOM tag. This article is focused on three type of radiation exposure information of DICOM standards, 1) DICOM dose SR, 2) DICOM MPPS and 3) Radiation Exposure Monitoring(REM) profile by Integrating the Healthcare Enterprise(IHE), to study on radiation exposure reporting. Healthcare facility and its staff of medical imaging related to radiation exposure should have a deep understanding of radiation exposure, and it required a standards to enhance the quality control of medical imaging and the safety of patients and staffs. Staff member have to pay attention on radiation exposures and controlling processes from the purchasing stage of X-ray devices.

Study on radiation dose in the medical image data display method-focus on the DICOM standard

International Nuclear Information System (INIS)

Kim, Jung Su

2015-01-01

DICOM (Digital Imaging and Communications in Medicine) standards are generally introduced as de facto and de jure standards in modern medical imaging devices to store and to transmit medical image information. DICOM Dose Structured Report (DICOM dose SR) is implemented to report radiation exposure information in image acquiring process. and DIOCM Modality Performed Procedure Step (DICOM MPPS) is also partly used to report this exposure with the information in its DICOM tag. This article is focused on three type of radiation exposure information of DICOM standards, 1) DICOM dose SR, 2) DICOM MPPS and 3) Radiation Exposure Monitoring(REM) profile by Integrating the Healthcare Enterprise(IHE), to study on radiation exposure reporting. Healthcare facility and its staff of medical imaging related to radiation exposure should have a deep understanding of radiation exposure, and it required a standards to enhance the quality control of medical imaging and the safety of patients and staffs. Staff member have to pay attention on radiation exposures and controlling processes from the purchasing stage of X-ray devices

PET/CT-guided Interventions: Personnel Radiation Dose

Energy Technology Data Exchange (ETDEWEB)

Ryan, E. Ronan, E-mail: ronan@ronanryan.com; Thornton, Raymond; Sofocleous, Constantinos T.; Erinjeri, Joseph P. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States); Hsu, Meier [Memorial Sloan-Kettering Cancer Center, Department of Epidemiology and Biostatistics (United States); Quinn, Brian; Dauer, Lawrence T. [Memorial Sloan-Kettering Cancer Center, Department of Medical Physics (United States); Solomon, Stephen B. [Memorial Sloan-Kettering Cancer Center, Department of Radiology (United States)

2013-08-01

PurposeTo quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.MethodsIn this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).ResultsThe median effective dose was 0.02 (range 0-0.13) mSv for the primary operator, 0.01 (range 0-0.05) mSv for the nurse anesthetist, and 0.02 (range 0-0.05) mSv for the radiology technologist. The median extremity dose equivalent for the operator was 0.05 (range 0-0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).ConclusionThe operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient.

Cosmic radiation doses at flight level altitudes of airliners

International Nuclear Information System (INIS)

Viragh, E.; Petr, I.

1985-01-01

Changes are discussed in flux density of cosmic radiation particles with time as are the origin of cosmic radiation, the level of cosmic radiation near the Earth's surface, and the determination of cosmic radiation doses in airliners. Doses and dose rates are given measured on different flight routes. In spite of the fact that the flight duration at an altitude of about 10 km makes for about 80% of the total flight time, the overall radiation burden of the crews at 1000 flight hours a year is roughly double that of the rest of the population. (J.C.)

Biological indicators for radiation absorbed dose: a review

International Nuclear Information System (INIS)

Paul, S.F.D.; Venkatachalam, P.; Jeevanram, R.K.

1996-01-01

Biological dosimetry has an important role to play in assessing the cumulative radiation exposure of persons working with radiation and also in estimating the true dose received during accidents involving external and internal exposure. Various biodosimetric methods have been tried to estimate radiation dose for the above purposes. Biodosimetric methods include cytogenetic, immunological and mutational assays. Each technique has certain advantages and disadvantages. We present here a review of each technique, the actual method used for detection of dose, the sensitivity of detection and its use in long term studies. (author)

Low dose ionizing radiation exposure and cardiovascular disease mortality: cohort study based on Canadian national dose registry of radiation workers

International Nuclear Information System (INIS)

Zielinski, J. M.; Band, P. R.; Ashmore, P. J.; Jiang, H.; Shilnikova, N. S.; Tait, V. K.; Krewski, D.

2009-01-01

The purpose of our study was to assess the risk of cardiovascular disease (CVD) mortality in a Canadian cohort of 337 397 individuals (169 256 men and 168 141 women) occupationally exposed to ionizing radiation and included in the National Dose Registry (NDR) of Canada. Material and Methods: Exposure to high doses of ionizing radiation, such as those received during radiotherapy, leads to increased risk of cardiovascular diseases. The emerging evidence of excess risk of CVDs after exposure to doses well below those previously considered as safe warrants epidemiological studies of populations exposed to low levels of ionizing radiation. In the present study, the cohort consisted of employees at nuclear power stations (nuclear workers) as well as medical, dental and industrial workers. The mean whole body radiation dose was 8.6 mSv for men and 1.2 mSv for women. Results: During the study period (1951 - 1995), as many as 3 533 deaths from cardiovascular diseases have been identified (3 018 among men and 515 among women). In the cohort, CVD mortality was significantly lower than in the general population of Canada. The cohort showed a significant dose response both among men and women. Risk estimates of CVD mortality in the NDR cohort, when expressed as excess relative risk per unit dose, were higher than those in most other occupational cohorts and higher than in the studies of Japanese atomic bomb survivors. Conclusions: The study has demonstrated a strong positive association between radiation dose and the risk of CVD mortality. Caution needs to be exercised when interpreting these results, due to the potential bias introduced by dosimetry uncertainties, the possible record linkage errors, and especially by the lack of adjustment for non-radiation risk factors. (authors)

Estimation of radiation dose received by the victims in a Chinese radiation accident

International Nuclear Information System (INIS)

Zhang, Liangan; Xu, Zhiyong; Jia, Delin; Dai, Guangfu

2002-01-01

In April 1999, a radiation accident happened in Henan province, China. In this accident, A 60 Co ex-service therapy radiation source was purchased by a waster purchase company, then some persons break the lead pot and taken out the stainless steel drawer with the radiation source, then sell the drawer to another small company, and the buyer reserved the drawer in his bed room until all of his family members shoot their cookies. During the event, seven persons received overdose exposure, the dose rang is about 1.0 - 6.0Gy, especially, all of the buyer family members meet with bad radiation damage. In order to assess the accident consequences and cure the patients of the bad radiation damage, it is necessary to estimate the doses of the Victims in the accident. In the dose reconstruction of the accident victims, we adopted biologic dose method, experiment-simulating method with an anthropomorphic phantom, and theory simulating method with Monte Carlo to estimate the doses of the victims. In this paper, the frame of the accident and the Monte Carlo method in our work will be described, the main dose results of the three methods mentioned above will be reported and a comparison analysis will be presented

The records of radiation control division, No.22 (1985)

International Nuclear Information System (INIS)

Fukui, Masami; Katsurayama, Kousuke; Ishida, Masahiro

1987-03-01

This report is a summary of activities of the radiation control division on the safety management in FY 1985. This report describes the records of the radiation control based on the activities of Indoor Radiation Control Section, Field Radiation Control Section and Personnel Radiation Control Section. External radiation doses were monitored using survey meters and film badges in the working area. Radioactive concentrations in dust and air were monitored in the radiation controlled area and at a number of locations outside the KURRI facilities. Reports of routine tasks such as the meteorological records, and the control of human exposure to radiation are described. This report also summarizes number of unscheduled tasks performed, including the replacement of the centralized monitoring board for radiation control, radiation monitors related to the extension of the spent fuel storage building, and the computer processing system of some indoor radiation monitors. Measurements of environmental radioactivity at several field locations are also presented in this report. (author)

Natural background radiation and population dose distribution in India

International Nuclear Information System (INIS)

Nambi, K.S.V.; Bapat, V.N.; David, M.; Sundaram, V.K.; Sunta, C.M.; Soman, S.D.

1986-01-01

A country-wide survey of the outdoor natural background gamma radiation levels has been made using mailed thermoluminescent dosimeters (TLDs). The salient features of the results are: (1) The air-kerma levels and the population doses in various states follow log-normal and normal distributions respectively. (2) The national average value for the air dose (air-kerma) is 775 ± 370 (1σ)μGy/y. (3) The lowest air-kerma recorded is 0.23 mGy/y at Minicoy (Laccadive Islands) and the highest is 26.73 mGy/y at Chavra (monazite areas, Kerala). (4) There are significant temporal variation s (even as high as ± 40 per cent) of the background radiation level at many locations and at least in 10 locations where radon/thoron measurements are available, these could be associated with the seasonal variations in radon/thoron levels. (5) The mail control TLDs indicate a country-wide average value of 785 ± 225 μGy/y for the air-kerma which can be considered to provide a truly national average value for the natural background radiation level in India. (6) The mean natural radiation per caput for the country works out to be 690 ± 200 (1σ) Sv/y. (7) The natural radiation per caput seems to be maximum for Andhra Pradesh (1065 ± 325 μSv/y) and minimum for Maharashtra (370 ± 80 μSv/y). (8) The population dose from the external natural background radiation is estimated to be half a million person-Sievert. (9) Assuming 1 CRP risk factor, it can be estimated that just one out of the 43 cancer deaths occurring on an average per 100,000 population in India, can be attributed to the external natural background radiation. (author). 18 refs., 13 tabs., 9 figs

Is Weight-Based Adjustment of Automatic Exposure Control Necessary for the Reduction of Chest CT Radiation Dose?

Science.gov (United States)

Prakash, Priyanka; Gilman, Matthew D.; Shepard, Jo-Anne O.; Digumarthy, Subba R.

2010-01-01

Objective To assess the effects of radiation dose reduction in the chest CT using a weight-based adjustment of the automatic exposure control (AEC) technique. Materials and Methods With Institutional Review Board Approval, 60 patients (mean age, 59.1 years; M:F = 35:25) and 57 weight-matched patients (mean age, 52.3 years, M:F = 25:32) were scanned using a weight-adjusted AEC and non-weight-adjusted AEC, respectively on a 64-slice multidetector CT with a 0.984:1 pitch, 0.5 second rotation time, 40 mm table feed/rotation, and 2.5 mm section thickness. Patients were categorized into 3 weight categories; 90 kg (n = 48). Patient weights, scanning parameters, CT dose index volumes (CTDIvol) and dose length product (DLP) were recorded, while effective dose (ED) was estimated. Image noise was measured in the descending thoracic aorta. Data were analyzed using a standard statistical package (SAS/STAT) (Version 9.1, SAS institute Inc, Cary, NC). Results Compared to the non-weight-adjusted AEC, the weight-adjusted AEC technique resulted in an average decrease of 29% in CTDIvol and a 27% effective dose reduction (p 91 kg weight groups, respectively, compared to 20.3, 27.9 and 32.8 mGy, with non-weight-adjusted AEC. No significant difference was observed for objective image noise between the chest CT acquired with the non-weight-adjusted (15.0 ± 3.1) and weight-adjusted (16.1 ± 5.6) AEC techniques (p > 0.05). Conclusion The results of this study suggest that AEC should be tailored according to patient weight. Without weight-based adjustment of AEC, patients are exposed to a 17 - 43% higher radiation-dose from a chest CT. PMID:20046494

Is Weight-Based Adjustment of Automatic Exposure Control Necessary for the Reduction of Chest CT Radiation Dose?

Energy Technology Data Exchange (ETDEWEB)

Prakash, Priyanka; Kalra, Mannudeep K.; Gilman, Matthew D.; Shepard, Jo Anne O.; Digumarthy, Subba R. [Massachusetts General Hospital and Harvard Medical School, Boston (United States)

2010-02-15

To assess the effects of radiation dose reduction in the chest CT using a weight-based adjustment of the automatic exposure control (AEC) technique. With Institutional Review Board Approval, 60 patients (mean age, 59.1 years; M:F = 35:25) and 57 weight-matched patients (mean age, 52.3 years, M:F = 25:32) were scanned using a weight-adjusted AEC and nonweight- adjusted AEC, respectively on a 64-slice multidetector CT with a 0.984:1 pitch, 0.5 second rotation time, 40 mm table feed/rotation, and 2.5 mm section thickness. Patients were categorized into 3 weight categories; < 60 kg (n = 17), 60-90 kg (n = 52), and > 90 kg (n = 48). Patient weights, scanning parameters, CT dose index volumes (CTDIvol) and dose length product (DLP) were recorded, while effective dose (ED) was estimated. Image noise was measured in the descending thoracic aorta. Data were analyzed using a standard statistical package (SAS/STAT) (Version 9.1, SAS institute Inc, Cary, NC). Compared to the non-weight-adjusted AEC, the weight-adjusted AEC technique resulted in an average decrease of 29% in CTDIvol and a 27% effective dose reduction (p < 0.0001). With weight-adjusted AEC, the CTDIvol decreased to 15.8, 15.9, and 27.3 mGy for the < 60, 60-90 and > 91 kg weight groups, respectively, compared to 20.3, 27.9 and 32.8 mGy, with non-weight adjusted AEC. No significant difference was observed for objective image noise between the chest CT acquired with the non-weight-adjusted (15.0 {+-} 3.1) and weight-adjusted (16.1 {+-} 5.6) AEC techniques (p > 0.05). The results of this study suggest that AEC should be tailored according to patient weight. Without weight-based adjustment of AEC, patients are exposed to a 17 - 43% higher radiation-dose from a chest CT.

Radiation dose modeling using IGRIP and Deneb/ERGO

International Nuclear Information System (INIS)

Vickers, D.S.; Davis, K.R.; Breazeal, N.L.; Watson, R.A.; Ford, M.S.

1995-01-01

The Radiological Environment Modeling System (REMS) quantifies dose to humans in radiation environments using the IGRIP (Interactive Graphical Robot Instruction Program) and Deneb/ERGO (Ergonomics) simulation software products. These commercially available products are augmented with custom C code to provide the radiation exposure information to and collect the radiation dose information from the workcell simulations. The emphasis of this paper is on the IGRIP and Deneb/ERGO parts of REMS, since that represents the extension to existing capabilities developed by the authors. Through the use of any radiation transport code or measured data, a radiation exposure input database may be formulated. User-specified IGRIP simulations utilize these database files to compute and accumulate dose to human devices (Deneb's ERGO human) during simulated operations around radiation sources. Timing, distances, shielding, and human activity may be modeled accurately in the simulations. The accumulated dose is recorded in output files, and the user is able to process and view this output. REMS was developed because the proposed reduction in the yearly radiation exposure limit will preclude or require changes in many of the manual operations currently being utilized in the Weapons Complex. This is particularly relevant in the area of dismantlement activities at the Pantex Plant in Amarillo, TX. Therefore, a capability was needed to be able to quantify the dose associated with certain manual processes so that the benefits of automation could be identified and understood

Optimization of the temporal pattern of applied dose for a single fraction of radiation: Implications for radiation therapy

Science.gov (United States)

Altman, Michael B.

The increasing prevalence of intensity modulated radiation therapy (IMRT) as a treatment modality has led to a renewed interest in the potential for interaction between prolonged treatment time, as frequently associated with IMRT, and the underlying radiobiology of the irradiated tissue. A particularly relevant aspect of radiobiology is cell repair capacity, which influences cell survival, and thus directly relates to the ability to control tumors and spare normal tissues. For a single fraction of radiation, the linear quadratic (LQ) model is commonly used to relate the radiation dose to the fraction of cells surviving. The LQ model implies a dependence on two time-related factors which correlate to radiobiological effects: the duration of radiation application, and the functional form of how the dose is applied over that time (the "temporal pattern of applied dose"). Although the former has been well studied, the latter has not. Thus, the goal of this research is to investigate the impact of the temporal pattern of applied dose on the survival of human cells and to explore how the manipulation of this temporal dose pattern may be incorporated into an IMRT-based radiation therapy treatment planning scheme. The hypothesis is that the temporal pattern of applied dose in a single fraction of radiation can be optimized to maximize or minimize cell kill. Furthermore, techniques which utilize this effect could have clinical ramifications. In situations where increased cell kill is desirable, such as tumor control, or limiting the degree of cell kill is important, such as the sparing of normal tissue, temporal sequences of dose which maximize or minimize cell kill (temporally "optimized" sequences) may provide greater benefit than current clinically used radiation patterns. In the first part of this work, an LQ-based modeling analysis of effects of the temporal pattern of dose on cell kill is performed. Through this, patterns are identified for maximizing cell kill for a

Effects of adaptive statistical iterative reconstruction on radiation dose reduction and diagnostic accuracy of pediatric abdominal CT

Energy Technology Data Exchange (ETDEWEB)

Bae, Sohi; Kim, Myung-Joon; Lee, Mi-Jung [Yonsei University College of Medicine, Department of Radiology and Research Institute of Radiological Science, Severance Children' s Hospital, Seoul (Korea, Republic of); Yoon, Choon-Sik [Yonsei University College of Medicine, Department of Radiology, Gangnam Severance Hospital, Seoul (Korea, Republic of); Kim, Dong Wook; Hong, Jung Hwa [Yonsei University College of Medicine, Biostatistics Collaboration Unit, Seoul (Korea, Republic of)

2014-12-15

Since children are more radio-sensitive than adults, there is a need to minimize radiation exposure during CT exams. To evaluate the effects of adaptive statistical iterative reconstruction (ASIR) on radiation dose reduction, image quality and diagnostic accuracy in pediatric abdominal CT. We retrospectively reviewed the abdominal CT examinations of 41 children (24 boys and 17 girls; mean age: 10 years) with a low-dose radiation protocol and reconstructed with ASIR (the ASIR group). We also reviewed routine-dose abdominal CT examinations of 41 age- and sex-matched controls reconstructed with filtered-back projection (control group). Image quality was assessed objectively as noise measured in the liver, spleen and aorta, as well as subjectively by three pediatric radiologists for diagnostic acceptability using a four-point scale. Radiation dose and objective image qualities of each group were compared with the paired t-test. Diagnostic accuracy was evaluated by reviewing follow-up imaging studies and medical records in 2012 and 2013. There was 46.3% dose reduction of size-specific dose estimates in ASIR group (from 13.4 to 7.2 mGy) compared with the control group. Objective noise was higher in the liver, spleen and aorta of the ASIR group (P < 0.001). However, the subjective image quality was average or superior in 84-100% of studies. Only one image was subjectively rated as unacceptable by one reviewer. There was only one case with interpretational error in the control group and none in the ASIR group. Use of the ASIR technique resulted in greater than a 45% reduction in radiation dose without impairing subjective image quality or diagnostic accuracy in pediatric abdominal CT, despite increased objective image noise. (orig.)

Effects of adaptive statistical iterative reconstruction on radiation dose reduction and diagnostic accuracy of pediatric abdominal CT

International Nuclear Information System (INIS)

Bae, Sohi; Kim, Myung-Joon; Lee, Mi-Jung; Yoon, Choon-Sik; Kim, Dong Wook; Hong, Jung Hwa

2014-01-01

Since children are more radio-sensitive than adults, there is a need to minimize radiation exposure during CT exams. To evaluate the effects of adaptive statistical iterative reconstruction (ASIR) on radiation dose reduction, image quality and diagnostic accuracy in pediatric abdominal CT. We retrospectively reviewed the abdominal CT examinations of 41 children (24 boys and 17 girls; mean age: 10 years) with a low-dose radiation protocol and reconstructed with ASIR (the ASIR group). We also reviewed routine-dose abdominal CT examinations of 41 age- and sex-matched controls reconstructed with filtered-back projection (control group). Image quality was assessed objectively as noise measured in the liver, spleen and aorta, as well as subjectively by three pediatric radiologists for diagnostic acceptability using a four-point scale. Radiation dose and objective image qualities of each group were compared with the paired t-test. Diagnostic accuracy was evaluated by reviewing follow-up imaging studies and medical records in 2012 and 2013. There was 46.3% dose reduction of size-specific dose estimates in ASIR group (from 13.4 to 7.2 mGy) compared with the control group. Objective noise was higher in the liver, spleen and aorta of the ASIR group (P < 0.001). However, the subjective image quality was average or superior in 84-100% of studies. Only one image was subjectively rated as unacceptable by one reviewer. There was only one case with interpretational error in the control group and none in the ASIR group. Use of the ASIR technique resulted in greater than a 45% reduction in radiation dose without impairing subjective image quality or diagnostic accuracy in pediatric abdominal CT, despite increased objective image noise. (orig.)

Potential gonadal dose from leakage radiation?

International Nuclear Information System (INIS)

Nicholson, R.A.

1995-01-01

The author draws attention to the potential dangers of leakage radiation from mobile image intensifier units, and points out that during interventional urological procedures, radiation from below the urologist's knees may irradiate male gonads without being intercepted by protective aprons. Results are presented for a Shimatzu WHA mobile II, phantom doses being measured with an ionization chamber. Dose rates measured in the male gonad position were compared with rates at waist level behind a 0.35 mm lead equivalent shielding and dose rates at collar level outside the lead apron. Results are also presented of a study on the effect on gonad dose of a) adding 0.7 mm lead shielding to the tube housing and b) adding 0.7 mm lead and removing the spacer cone to reduce scatter. Results show that it is possible for gonad doses to be comparable with those assumed for the eyes, rather than the body. (Author)

Audit of radiation dose during balloon mitral valvuloplasty procedure

International Nuclear Information System (INIS)

Livingstone, Roshan S; Chandy, Sunil; Peace, B S Timothy; George, Paul; John, Bobby; Pati, Purendra

2006-01-01

Radiation doses to patients during cardiological procedures are of concern in the present day scenario. This study was intended to audit the radiation dose imparted to patients during the balloon mitral valvuloplasty (BMV) procedure. Thirty seven patients who underwent the BMV procedure performed using two dedicated cardiovascular machines were included in the study. The radiation doses imparted to patients were measured using a dose area product (DAP) meter. The mean DAP value for patients who underwent the BMV procedure from one machine was 19.16 Gy cm 2 and from the other was 21.19 Gy cm 2 . Optimisation of exposure parameters and radiation doses was possible for one machine with the use of appropriate copper filters and optimised exposure parameters, and the mean DAP value after optimisation was 9.36 Gy cm 2

Design of radiation dose tumor response assays

International Nuclear Information System (INIS)

Suit, H.D.; Hwang, T.; Hsieh, C.; Thames, H.

1985-01-01

The efficient utilization of animals in a radiation dose response assay for tumor control requires a definition of the goal, e.g., TCD50 or slope. A series of computer modelled ''experiments'' have been performed for each of a number of allocations of dose levels (DL) and number of animals/DL. The authors stipulated that the assumed TCD50 was .85 of true value; assumed slope was correct. They stipulated a binominal distribution of observed tumor control results at each dose level. A pilot assay used 6 tumors at 7 DL (from TCD1-TCD97). The second assay used 30 tumors assigned to 2,3,5 or 9 DL and to selected tumor control probabilities (TCP derived from the pilot run. Results from 100 test runs were combined with the pilot run for each of the combination of DL and TCP values. Logit regression lines were fitted through these ''data'' and the 95% CL around the TCD50 and the TCD37 values and the variances of the slopes were computed. These experiments were repeated using the method suggested by Porter (1980). Results show that a different strategy is needed depending upon the goal, viz. TCD50 or TCD37 vs slope. The differences between the two approaches are discussed

Exposure to low doses of ionizing radiations

International Nuclear Information System (INIS)

Le Guen, B.

2008-01-01

The author discusses the knowledge about the effects of ionizing radiations on mankind. Some of them have been well documented (skin cancer and leukaemia for the pioneer scientists who worked on radiations, some other types of cancer for workers who handled luminescent paints, rock miners, nuclear explosion survivors, patients submitted to radiological treatments). He also evokes the issue of hereditary cancers, and discusses the issue of low dose irradiation where some surveys can now be performed on workers. He discusses the biological effects of these low doses. He outlines that many questions remain about these effects, notably the influence of dose level and of dose rate level on the biological reaction

The 3D Radiation Dose Analysis For Satellite

Science.gov (United States)

Cai, Zhenbo; Lin, Guocheng; Chen, Guozhen; Liu, Xia

2002-01-01

the earth. These particles come from the Van Allen Belt, Solar Cosmic Ray and Galaxy Cosmic Ray. They have different energy and flux, varying with time and space, and correlating with solar activity tightly. These particles interact with electrical components and materials used on satellites, producing various space radiation effects, which will damage satellite to some extent, or even affect its safety. orbit. Space energy particles inject into components and materials used on satellites, and generate radiation dose by depositing partial or entire energy in them through ionization, which causes their characteristic degradation or even failure. As a consequence, the analysis and protection for radiation dose has been paid more attention during satellite design and manufacture. Designers of satellites need to analyze accurately the space radiation dose while satellites are on orbit, and use the results as the basis for radiation protection designs and ground experiments for satellites. can be calculated, using the model of the trapped proton and the trapped electron in the Van Allen Belt (AE8 and AP8). This is the 1D radiation dose analysis for satellites. Obviously, the mass shielding from the outside space to the computed point in all directions is regarded as a simple sphere shell. The actual structure of satellites, however, is very complex. When energy particles are injecting into a given equipment inside satellite from outside space, they will travel across satellite structure, other equipment, the shell of the given equipment, and so on, which depends greatly on actual layout of satellite. This complex radiation shielding has two characteristics. One is that the shielding masses for the computed point are different in different injecting directions. The other is that for different computed points, the shielding conditions vary in all space directions. Therefore, it is very difficult to tell the differences described above using the 1D radiation analysis, and

Online radiation dose measurement system for ATLAS experiment

International Nuclear Information System (INIS)

Mandic, I.; Cindro, V.; Dolenc, I.; Gorisek, A.; Kramberger, G.; Mikuz, M.; Bronner, J.; Hartet, J.; Franz, S.

2009-01-01

In experiments at Large Hadron Collider, detectors and electronics will be exposed to high fluxes of photons, charged particles and neutrons. Damage caused by the radiation will influence performance of detectors. It will therefore be important to continuously monitor the radiation dose in order to follow the level of degradation of detectors and electronics and to correctly predict future radiation damage. A system for online radiation monitoring using semiconductor radiation sensors at large number of locations has been installed in the ATLAS experiment. Ionizing dose in SiO 2 will be measured with RadFETs, displacement damage in silicon in units of 1-MeV(Si) equivalent neutron fluence with p-i-n diodes. At 14 monitoring locations where highest radiation levels are expected the fluence of thermal neutrons will be measured from current gain degradation in dedicated bipolar transistors. The design of the system and tests of its performance in mixed radiation field is described in this paper. First results from this test campaign confirm that doses can be measured with sufficient sensitivity (mGy for total ionizing dose measurements, 10 9 n/cm 2 for NIEL (non-ionizing energy loss) measurements, 10 12 n/cm 2 for thermal neutrons) and accuracy (about 20%) for usage in the ATLAS detector

Gamma radiation in pest control at the storehouses

International Nuclear Information System (INIS)

Tsvetkov, D.; Atanasov, Khr.; Berberov, D.

1974-01-01

The prospects of radiation control of wheat grain pests in Bulgaria are shown, drawing the following main conclusions: The lethal doses of gamma rays for the granary weevil, grain borer and confused flour beetle are fairly high - of the order of 300,000-400,000 r; the sterilizing doses of gamma rays arrest the reproduction of granary and rice weevils as well as of confused flour beetles. The irradiated insects, however, retain their sex activity and so may inhibit the reproduction of fertile populations. Irradiation strongly reduces the life span of, and consequently the damage done by, the insects; radiation control of stored-grain pests by using sterilizing doses does not deteriorate the technological quality of the wheat grain. (E.T.)

Knowledge of medical imaging radiation dose and risk among doctors

International Nuclear Information System (INIS)

Brown, Nicholas; Jones, Lee

2013-01-01

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

Radiation dose in paediatric cardiac catheterisation: A systematic literature review

International Nuclear Information System (INIS)

Gould, R.; McFadden, S.L.; Hughes, C.M.

2017-01-01

Objectives: It is believed that children are more sensitive to ionising radiation than adults. This work reviewed the reported radiation dose estimates for paediatric cardiac catheterisation. A systematic literature review was performed by searching healthcare databases for studies reporting radiation dose using predetermined key words relating to children having cardiac catheterisation. The quality of publications was assessed using relevant Critical Appraisal Skills Programme questions and their reported radiation exposures were evaluated. Key findings: It is only in recent years that larger cohort observations have been undertaken. Although radiation dose from paediatric cardiac catheterisation has decreased in recent years, the literature indicated that it remains varied and potentially substantial. Conclusion: Standardisation of weight categories and procedure types such as those recommended by the PiDRL project could help compare current and future radiation dose estimates. - Highlights: • 31 articles reporting radiation dose from paediatric cardiac catheterisation were reviewed. • In recent years, larger cohorts (>1000) have been reported. • Radiation dose to children has been lowered in the last decade but remains varied. • Future dosimetry should be consistent for weight categories and procedure types.

Optimizing Radiation Doses for Computed Tomography Across Institutions: Dose Auditing and Best Practices.

Science.gov (United States)

Demb, Joshua; Chu, Philip; Nelson, Thomas; Hall, David; Seibert, Anthony; Lamba, Ramit; Boone, John; Krishnam, Mayil; Cagnon, Christopher; Bostani, Maryam; Gould, Robert; Miglioretti, Diana; Smith-Bindman, Rebecca

2017-06-01

Radiation doses for computed tomography (CT) vary substantially across institutions. To assess the impact of institutional-level audit and collaborative efforts to share best practices on CT radiation doses across 5 University of California (UC) medical centers. In this before/after interventional study, we prospectively collected radiation dose metrics on all diagnostic CT examinations performed between October 1, 2013, and December 31, 2014, at 5 medical centers. Using data from January to March (baseline), we created audit reports detailing the distribution of radiation dose metrics for chest, abdomen, and head CT scans. In April, we shared reports with the medical centers and invited radiology professionals from the centers to a 1.5-day in-person meeting to review reports and share best practices. We calculated changes in mean effective dose 12 weeks before and after the audits and meeting, excluding a 12-week implementation period when medical centers could make changes. We compared proportions of examinations exceeding previously published benchmarks at baseline and following the audit and meeting, and calculated changes in proportion of examinations exceeding benchmarks. Of 158 274 diagnostic CT scans performed in the study period, 29 594 CT scans were performed in the 3 months before and 32 839 CT scans were performed 12 to 24 weeks after the audit and meeting. Reductions in mean effective dose were considerable for chest and abdomen. Mean effective dose for chest CT decreased from 13.2 to 10.7 mSv (18.9% reduction; 95% CI, 18.0%-19.8%). Reductions at individual medical centers ranged from 3.8% to 23.5%. The mean effective dose for abdominal CT decreased from 20.0 to 15.0 mSv (25.0% reduction; 95% CI, 24.3%-25.8%). Reductions at individual medical centers ranged from 10.8% to 34.7%. The number of CT scans that had an effective dose measurement that exceeded benchmarks was reduced considerably by 48% and 54% for chest and abdomen, respectively. After

Radiation retinopathy caused by low dose irradiation and antithyroid drug-induced systemic vasculitis

International Nuclear Information System (INIS)

Sonoda, Koh-hei; Ishibashi, Tatsuro

2005-01-01

We report on a patient with Graves' disease with radiation retinopathy caused by low-dose irradiation and antithyroid drug-induced antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. A 38-year-old woman with Graves' disease presented with bilateral blurred vision, micro-aneurysms, telangiectasia, and macular edema. The patient was examined by ophthalmoscopy and fluorescein angiography, and radiation retinopathy was diagnosed. The patient had been treated with low-dose irradiation for her Graves' ophthalmopathy a few years earlier. She also had ANCA-positive vasculitis induced by the antithyroid drug (propylthiouracil, PTU) that had been prescribed for her at that time. Because of multiple avascular areas on both retinas, she was treated by intensive retinal photocoagulation to control progressive retinopathy. The radiation doses used to treat Graves' disease ophthalmopathy are low. Nevertheless, there is still a risk of radiation retinopathy developing in patients with PTU-induced ANCA-positive vasculitis. (author)

Natural background radiation and population dose in China

Energy Technology Data Exchange (ETDEWEB)

Guangzhi, C. (Ministry of Public Health, Beijing, BJ (China)); Ziqiang, P.; Zhenyum, H.; Yin, Y.; Mingqiang, G.

On the basis of analyzing the data for the natural background radiation level in China, the typical values for indoor and outdoor terrestrial gamma radiation and effective dose equivalents from radon and thoron daughters are recommended. The annual effective dose equivalent from natural radiation to the inhabitant is estimated to be 2.3 mSv, in which 0.54 mSv is from terrestrial gamma radiation and about 0,8 mSv is from radon and its short-lived daughters. 55 Refs.

Decreasing the effective radiation dose in pediatric craniofacial CT by changing head position

International Nuclear Information System (INIS)

Didier, Ryne A.; Kuang, Anna A.; Schwartz, Daniel L.; Selden, Nathan R.; Stevens, Donna M.; Bardo, Dianna M.E.

2010-01-01

Children are exposed to ionizing radiation during pre- and post-operative evaluation for craniofacial surgery. The primary purpose of the study was to decrease effective radiation dose while preserving the diagnostic quality of the study. In this prospective study 49 children were positioned during craniofacial CT (CFCT) imaging with their neck fully extended into an exaggerated sniff position, parallel to the CT gantry, to eliminate the majority of the cervical spine and the thyroid gland from radiation exposure. Image-quality and effective radiation dose comparisons were made retrospectively in age-matched controls (n = 49). When compared to CT scans reviewed retrospectively, the prospective examinations showed a statistically significant decrease in z-axis length by 16% (P < 0.0001) and delivered a reduced effective radiation dose by 18% (P < 0.0001). The subjective diagnostic quality of the exams performed in the prospective arm was maintained despite a slight decrease in the quality of the brain windows. There was statistically significant improvement in the quality of the bone windows and three-dimensional reconstructed images. Altering the position of the head by extending the neck during pediatric craniofacial CT imaging statistically reduces the effective radiation dose while maintaining the diagnostic quality of the images. (orig.)

Attributability of health effects at low radiation doses

International Nuclear Information System (INIS)

Gonzalez, Abel

2008-01-01

Full text: A controversy still persists on whether health effects can be alleged from radiation exposure situations involving low radiation doses (e.g. below the international dose limits for the public). Arguments have evolved around the validity of the dose-response representation that is internationally used for radiation protection purposes, namely the so-called linear-non-threshold (LNT) model. The debate has been masked by the intrinsic randomness of radiation interaction at the cellular level and also by gaps in the relevant scientific knowledge on the development and expression of health effects. There has also been a vague use, abuse, and misuse of radiation-related risk concepts and quantities and their associated uncertainties. As a result, there is some ambiguity in the interpretation of the phenomena and a general lack of awareness of the implications for a number of risk-causation qualities, namely its attributes and characteristics. In particular, the LNT model has been used not only for protection purposes but also for blindly attributing actual effects to specific exposure situations. The latter has been discouraged as being a misuse of the model, but the supposed incorrectness has not been clearly proven. The paper will endeavour to demonstrate unambiguously the following thesis in relation to health effects due to low radiation doses: 1) Their existence is highly plausible. A number of epidemiological statistical assessments of sufficiently large exposed populations show that, under certain conditions, the prevalence of the effects increases with dose. From these assessments, it can be hypothesized that the occurrence of the effects at any dose, however small, appears decidedly worthy of belief. While strictly the evidence does not allow to conclude that a threshold dose level does not exist either. In fact, a formal quantitative uncertainty analysis, combining the different uncertain components of estimated radiation-related risk, with and

Attributability of Health Effects at Low Radiation Doses

International Nuclear Information System (INIS)

Gonzalez, A.J.

2011-01-01

Full text: A controversy still persists on whether health effects can be alleged from radiation exposure situations involving low radiation doses (e.g. below the international dose limits for the public). Arguments have evolved around the validity of the dose response representation that is internationally used for radiation protection purposes, namely the so-called linear-non-threshold (LNT) model. The debate has been masked by the intrinsic randomness of radiation interaction at the cellular level and also by gaps in the relevant scientific knowledge on the development and expression of health effects. There has also been a vague use, abuse, and misuse of radiation-related risk concepts and quantities and their associated uncertainties. As a result, there is some ambiguity in the interpretation of the phenomena and a general lack of awareness of the implications for a number of risk-causation qualities, namely its attributes and characteristics. In particular, the LNT model has been used not only for protection purposes but also for blindly attributing actual effects to specific exposure situations. The latter has been discouraged as being a misuse of the model, but the supposed incorrectness has not been clearly proven. The paper will endeavour to demonstrate unambiguously the following thesis in relation to health effects due to low radiation doses: (i) Their existence is highly plausible. A number of epidemiological statistical assessments of sufficiently large exposed populations show that, under certain conditions, the prevalence of the effects increases with dose. From these assessments, it can be hypothesized that the occurrence of the effects at any dose, however small, appears decidedly worthy of belief. While strictly the evidence does not allow to conclude that a threshold dose level does not exist either In fact, a formal quantitative uncertainty analysis, combining the different uncertain components of estimated radiation-related risk, with and

Measurement and assessment of doses from external radiations required for revised radiation protection regulations

Energy Technology Data Exchange (ETDEWEB)

Tsujimura, Norio; Kojima, Noboru; Hayashi, Naomi [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan)

2001-06-01

Radiation protection regulations based on the 1990 recommendations of ICRP have been revised and will take effect from Apr., 2001. The major changes concerning on the measurement and assessment of doses from external radiations are as follows. (1) Personal dose equivalent and ambient dose equivalent stated in ICRP Publication 74 are introduced as quantities to be measured with personal dosimeters and survey instruments, respectively. (2) For multiple dosimetry for workers, the compartment weighting factors used for a realistic assessment of effective dose are markedly changed. In advance of the introduction of the new radiation protection regulations, the impacts on workplace and personal monitoring for external radiations by these revisions were investigated. The following results were obtained. (1) A new ambient dose equivalent to neutrons is higher with a factor of 1.2 than the old one for moderated fission neutron spectra. Therefore, neutron dose equivalent monitors for workplace monitoring at MOX fuel for facilities should be recalibrated for measurement of the new ambient dose equivalent. (2) Annual effective doses of workers were estimated by applying new calibration factors to readings of personal dosimeters, worn by workers. Differences between effective doses and effective dose equivalents are small for workers engaged in the fabrication process of MOX fuel. (author)

Measurement and assessment of doses from external radiations required for revised radiation protection regulations

International Nuclear Information System (INIS)

Tsujimura, Norio; Kojima, Noboru; Hayashi, Naomi

2001-01-01

Radiation protection regulations based on the 1990 recommendations of ICRP have been revised and will take effect from Apr., 2001. The major changes concerning on the measurement and assessment of doses from external radiations are as follows. (1) Personal dose equivalent and ambient dose equivalent stated in ICRP Publication 74 are introduced as quantities to be measured with personal dosimeters and survey instruments, respectively. (2) For multiple dosimetry for workers, the compartment weighting factors used for a realistic assessment of effective dose are markedly changed. In advance of the introduction of the new radiation protection regulations, the impacts on workplace and personal monitoring for external radiations by these revisions were investigated. The following results were obtained. (1) A new ambient dose equivalent to neutrons is higher with a factor of 1.2 than the old one for moderated fission neutron spectra. Therefore, neutron dose equivalent monitors for workplace monitoring at MOX fuel for facilities should be recalibrated for measurement of the new ambient dose equivalent. (2) Annual effective doses of workers were estimated by applying new calibration factors to readings of personal dosimeters, worn by workers. Differences between effective doses and effective dose equivalents are small for workers engaged in the fabrication process of MOX fuel. (author)

On the use of age-specific effective dose coefficients in radiation protection of the public

International Nuclear Information System (INIS)

Kocher, D.C.; Eckerman, K.F.

1998-01-01

Current radiation protection standards for the public include a limit on effective dose in any year for individuals in critical groups. This paper considers the question of how the annual dose limit should be applied in controlling routine exposures of populations consisting of individuals of all ages. We assume that the fundamental objective of radiation protection is limitation of lifetime risk and, therefore, that standards for controlling routine exposures of the public should provide a reasonable correspondence with lifetime risk, taking into account the age dependence of intakes and doses and the variety of radionuclides and exposure pathways of concern. Using new calculations of the per capita (population-averaged) risk of cancer mortality per unit activity inhaled or ingested in the U.S. Environmental Protection Agency's Federal Guidance Report No. 13, we show that applying a limit on annual effective dose only to adults, which was the usual practice in radiation protection of the public before the development of age-specific effective dose coefficients, provides a considerably better correspondence with lifetime risk that applying the annual dose limit to the critical group of any age. (author)

On the use of age-specific effective dose coefficients in radiation protection of the public

International Nuclear Information System (INIS)

Kocher, D.C.; Eckerman, K.F.

1998-01-01

Current radiation protection standards for the public include a limit on effective dose in any year for individuals in critical groups. This paper considers the question of how the annual dose limit should be applied in controlling routine exposures of populations consisting of individuals of all ages. The authors assume that the fundamental objective of radiation protection is limitation of lifetime risk and, therefore, that standards for controlling routine exposures of the public should provide a reasonable correspondence with lifetime risk, taking into account the age dependence of intakes and doses and the variety of radionuclides and exposure pathways of concern. Using new calculations of the per capita (population-averaged) risk of cancer mortality per unit activity inhaled or ingested in the US Environmental Protection Agency's Federal Guidance Report No. 13, the authors show that applying a limit on annual effective dose only to adults, which was the usual practice in radiation protection of the public before the development of age-specific effective dose coefficients, provides a considerably better correspondence with lifetime risk than applying the annual dose limit to the critical group of any age

Radiation doses and risks from internal emitters

International Nuclear Information System (INIS)

Harrison, John; Day, Philip

2008-01-01

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

Monitoring and assessment of individual doses of occupationally exposed workers due to external radiation

International Nuclear Information System (INIS)

Kitaw, S. T.

2015-05-01

Exposure to external radiation occurs in many occupations. Any exposure to ionizing radiation has the tendency to change the biochemical make-up of the human body which may result in biological health effects of ionizing radiation. This study reviews the monitoring and assessment of external radiation doses in industrial radiography using thermoluminescence and direct reading dosimeters. Poor handling procedures such as inadequate engineering control of equipment, safety culture, management, and inadequate assessment and monitoring of doses are the causes of most of the reported cases of exposure to external radiation in industrial radiography. Occupational exposure data in industrial radiography from UNSCEAR report 2008 was discussed and recommendations were made to regulatory authorities, operating organizations and radiographers. (au)