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1

Overview of Radiation Environments and Human Exposures  

NASA Technical Reports Server (NTRS)

Human exposures to ionizing radiation have been vastly altered by developing technology in the last century. This has been most obvious in the development of radiation generating devices and the utilization of nuclear energy. But even air travel has had its impact on human exposure. Human exposure increases with advancing aircraft technology as a result of the higher operating altitudes reducing the protective cover provided by the Earth s atmosphere from extraterrestrial radiations. This increase in operating altitudes is taken to a limit by human operations in space. Less obvious is the changing character of the radiations at higher altitudes. The associated health risks are less understood with increasing altitude due to the increasing complexity and new field components found in high altitude and space operations.

Wilson, John W.

2004-01-01

2

A Translatable Predictor of Human Radiation Exposure  

PubMed Central

Terrorism using radiological dirty bombs or improvised nuclear devices is recognized as a major threat to both public health and national security. In the event of a radiological or nuclear disaster, rapid and accurate biodosimetry of thousands of potentially affected individuals will be essential for effective medical management to occur. Currently, health care providers lack an accurate, high-throughput biodosimetric assay which is suitable for the triage of large numbers of radiation injury victims. Here, we describe the development of a biodosimetric assay based on the analysis of irradiated mice, ex vivo-irradiated human peripheral blood (PB) and humans treated with total body irradiation (TBI). Interestingly, a gene expression profile developed via analysis of murine PB radiation response alone was inaccurate in predicting human radiation injury. In contrast, generation of a gene expression profile which incorporated data from ex vivo irradiated human PB and human TBI patients yielded an 18-gene radiation classifier which was highly accurate at predicting human radiation status and discriminating medically relevant radiation dose levels in human samples. Although the patient population was relatively small, the accuracy of this classifier in discriminating radiation dose levels in human TBI patients was not substantially confounded by gender, diagnosis or prior exposure to chemotherapy. We have further incorporated genes from this human radiation signature into a rapid and high-throughput chemical ligation-dependent probe amplification assay (CLPA) which was able to discriminate radiation dose levels in a pilot study of ex vivo irradiated human blood and samples from human TBI patients. Our results illustrate the potential for translation of a human genetic signature for the diagnosis of human radiation exposure and suggest the basis for further testing of CLPA as a candidate biodosimetric assay. PMID:25255453

Suchindran, Sunil; Nakamura, Mai; Chao, Nelson J.; Himburg, Heather; Minor, Kerry; Phillips, Gary; Ross, Joel; Abedi, Majid; Terbrueggen, Robert; Chute, John P.

2014-01-01

3

A translatable predictor of human radiation exposure.  

PubMed

Terrorism using radiological dirty bombs or improvised nuclear devices is recognized as a major threat to both public health and national security. In the event of a radiological or nuclear disaster, rapid and accurate biodosimetry of thousands of potentially affected individuals will be essential for effective medical management to occur. Currently, health care providers lack an accurate, high-throughput biodosimetric assay which is suitable for the triage of large numbers of radiation injury victims. Here, we describe the development of a biodosimetric assay based on the analysis of irradiated mice, ex vivo-irradiated human peripheral blood (PB) and humans treated with total body irradiation (TBI). Interestingly, a gene expression profile developed via analysis of murine PB radiation response alone was inaccurate in predicting human radiation injury. In contrast, generation of a gene expression profile which incorporated data from ex vivo irradiated human PB and human TBI patients yielded an 18-gene radiation classifier which was highly accurate at predicting human radiation status and discriminating medically relevant radiation dose levels in human samples. Although the patient population was relatively small, the accuracy of this classifier in discriminating radiation dose levels in human TBI patients was not substantially confounded by gender, diagnosis or prior exposure to chemotherapy. We have further incorporated genes from this human radiation signature into a rapid and high-throughput chemical ligation-dependent probe amplification assay (CLPA) which was able to discriminate radiation dose levels in a pilot study of ex vivo irradiated human blood and samples from human TBI patients. Our results illustrate the potential for translation of a human genetic signature for the diagnosis of human radiation exposure and suggest the basis for further testing of CLPA as a candidate biodosimetric assay. PMID:25255453

Lucas, Joseph; Dressman, Holly K; Suchindran, Sunil; Nakamura, Mai; Chao, Nelson J; Himburg, Heather; Minor, Kerry; Phillips, Gary; Ross, Joel; Abedi, Majid; Terbrueggen, Robert; Chute, John P

2014-01-01

4

Atmospheric Ionizing Radiation and Human Exposure  

NASA Technical Reports Server (NTRS)

Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes. especially along the coastal plain and interior low lands, and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.

Wilson, John W.; Mertens, Christopher J.; Goldhagen, Paul; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.

2005-01-01

5

Atmospheric Ionizing Radiation and Human Exposure  

NASA Technical Reports Server (NTRS)

Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes especially along the coastal plain and interior low lands and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.

Wilson, J. W.; Goldhagen, P.; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.

2004-01-01

6

[Effects of radiation exposure on human body].  

PubMed

There are two types of radiation health effect; acute disorder and late on-set disorder. Acute disorder is a deterministic effect that the symptoms appear by exposure above a threshold. Tissues and cells that compose the human body have different radiation sensitivity respectively, and the symptoms appear in order, from highly radiosensitive tissues. The clinical symptoms of acute disorder begin with a decrease in lymphocytes, and then the symptoms appear such as alopecia, skin erythema, hematopoietic damage, gastrointestinal damage, central nervous system damage with increasing radiation dose. Regarding the late on-set disorder, a predominant health effect is the cancer among the symptoms of such as cancer, non-cancer disease and genetic effect. Cancer and genetic effect are recognized as stochastic effects without the threshold. When radiation dose is equal to or more than 100 mSv, it is observed that the cancer risk by radiation exposure increases linearly with an increase in dose. On the other hand, the risk of developing cancer through low-dose radiation exposure, less 100 mSv, has not yet been clarified scientifically. Although uncertainty still remains regarding low level risk estimation, ICRP propound LNT model and conduct radiation protection in accordance with LNT model in the low-dose and low-dose rate radiation from a position of radiation protection. Meanwhile, the mechanism of radiation damage has been gradually clarified. The initial event of radiation-induced diseases is thought to be the damage to genome such as radiation-induced DNA double-strand breaks. Recently, it is clarified that our cells could recognize genome damage and induce the diverse cell response to maintain genome integrity. This phenomenon is called DNA damage response which induces the cell cycle arrest, DNA repair, apoptosis, cell senescence and so on. These responses act in the direction to maintain genome integrity against genome damage, however, the death of large number of cells results in acute disorder, and then DNA mis-repair and mutation is speculated to cause cancer. The extent to which this kind of cellular response could reduce the low-dose radiation risk is a major challenge for future research. PMID:22514910

Kamiya, Kenji; Sasatani, Megumi

2012-03-01

7

Human performance analysis of industrial radiography radiation exposure events  

SciTech Connect

A set of radiation overexposure event reports were reviewed as part of a program to examine human performance in industrial radiography for the US Nuclear Regulatory Commission. Incident records for a seven year period were retrieved from an event database. Ninety-five exposure events were initially categorized and sorted for further analysis. Descriptive models were applied to a subset of severe overexposure events. Modeling included: (1) operational sequence tables to outline the key human actions and interactions with equipment, (2) human reliability event trees, (3) an application of an information processing failures model, and (4) an extrapolated use of the error influences and effects diagram. Results of the modeling analyses provided insights into the industrial radiography task and suggested areas for further action and study to decrease overexposures.

Reece, W.J.; Hill, S.G.

1995-12-01

8

Radiation exposure to human trachea from Xenon-133 procedures  

SciTech Connect

The general dosimetry of {sup 133}Xe for human studies is well documented, but the resultant radiation exposure to tracheal tissue is poorly known. This organ is of central relevance because the tracer is primarily eliminated through exhalation. We report actual {sup 133}Xe concentrations in respiratory air during measurement of regional cerebral blood flow (rCBF), when the tracer is administered both by inhalation and intravenous injection. Data were collected from 102 patients, with equal gender representation and an age range of 18-82 yr. Most of the patients had subarachnoid hemorrhage or Alzheimer`s disease or were normal control subjects. Average administered doses were 18 {plus_minus} 4 mCi by inhalation and 15 {plus_minus} 3 intravenously. We found average respiratory concentrations of about 1.80 mCi/liter during a 1-min inhalation and 0.74 mCi/liter following intravenous injection of standard doses. These activities drop rapidly: average respiratory concentrations during the second minute are 0.70 mCi/liter for inhalation and 0.19 mCi/liter for intravenous injection and reach negligible levels thereafter. We calculate that the tracheal absorbed dose from {sup 133}Xe procedures is approximately 28 mrad following inhalation and about 11 mrad following intravenous injection. These values reflect the full 11-min exposure, but most of the activity is only present initially. These values will agree with previous estimates and indicate an excellent safety margin. 6 refs., 2 figs., 1 tab.

Prohovnik, I.; Metz, C.D.; Atkins, H.L. [New York State Psychiatric Inst., New York, NY (United States)]|[Brookhaven National Laboratories, Upton, NY (United States)]|[Columbia Univ., New York, NY (United States)

1995-08-01

9

Computer subroutines for estimation of human exposure to radiation in low Earth orbit  

NASA Technical Reports Server (NTRS)

Computer subroutines to calculate human exposure to trapped radiations in low Earth orbit (LEO) on the basis of a simple approximation of the human geometry by spherical shell shields of varying thickness are presented and detailed. The subroutines calculate the dose to critical body organs and the fraction of exposure limit reached as a function of altitude of orbit, degree of inclination, shield thickness, and days in mission. Exposure rates are compared with current exposure limits.

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

1985-01-01

10

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

PubMed

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

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

2009-06-01

11

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

PubMed Central

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

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

2014-01-01

12

Response of intracerebral human glioblastoma xenografts to multifraction radiation exposures  

SciTech Connect

Purpose: We investigated the effects of fractionated radiation treatments on the life spans of athymic rats bearing intracerebral brain tumors. Methods and Materials: U-251 MG or U-87 MG human glioblastoma cells were implanted into the brains of athymic rats, and the resulting tumors were irradiated once daily with various doses of ionizing radiation for 5 consecutive days or for 10 days with a 2-day break after Day 5. Results: Five daily doses of 1 and 1.5 Gy, and 10 doses of 0.75 and 1 Gy, cured some U-251 MG tumors. However, five daily doses of 0.5 Gy increased the survival time of animals bearing U-251 MG tumors 5 days without curing any animals of their tumors. Ten doses of 0.3 Gy given over 2 weeks extended the lifespan of the host animals 9 days without curing any animals. For U-87 MG tumors, 5 daily doses of 3 Gy produced an increased lifespan of 8 days without curing any animals, and 10 doses of 1 Gy prolonged lifespan 5.5 days without curing any animals. The differences in extension of life span between the 5- and 10-fraction protocols were minor for either tumor type. Conclusion: The finding that the U-251 MG tumors are more sensitive than U-87 MG tumors, despite the fact that U-251 MG tumors contain many more hypoxic cells than U-87 MG tumors, suggests the intrinsic cellular radiosensitivities of these cell lines are more important than hypoxia in determining their in vivo radiosensitivities.

Ozawa, Tomoko [Brain Tumor Research Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA (United States); Faddegon, Bruce A. [Department of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States); Hu, Lily J. [Brain Tumor Research Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA (United States); Bollen, Andrew W. [Department of Pathology, University of California San Francisco, San Francisco, CA (United States); Lamborn, Kathleen R. [Brain Tumor Research Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA (United States); Deen, Dennis F. [Brain Tumor Research Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA (United States) and Department of Radiation Oncology, University of California San Francisco, San Francisco, CA (United States)]. E-mail: ddeen@itsa.ucsf.edu

2006-09-01

13

Human Space Exploration and Radiation Exposure from EVA: 1981-2011  

NASA Astrophysics Data System (ADS)

There are several risks for any human space exploration endeavor. One such inevitable risk is exposure to the space radiation environment of which extra vehicular activity (EVA) demands more challenges due to limited amount of protection from space suit shielding. We recently compiled all EVA data comprising low-earth orbit (LEO) from Space Shuttle (STS) flights, International Space Station (ISS) expeditions, and Shuttle-Mir missions. Assessment of such radiation risk is very important, particularly for the anticipated long-term, deep-space human explorations in the near future. We present our assessment of anticipated radiation exposure and space radiation dose contribution to each crew member from a listing of 350 different EVA events resulting in more than 1000+ hrs of total EVA time. As of July 12, 2011, 197 astronauts have made spacewalks (out of 520 people who have gone into Earth orbit). Only 11 women have been on spacewalks.

Way, A. R.; Saganti, S. P.; Erickson, G. M.; Saganti, P. B.

2011-12-01

14

Radiation Exposure  

MedlinePLUS

Radiation is energy that travels in the form of waves or high-speed particles. It occurs naturally in sunlight. Man-made radiation is used in X-rays, nuclear weapons, nuclear power plants and cancer treatment. If you are exposed to small amounts of radiation over a ...

15

Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation.  

PubMed Central

The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain, for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy. PMID:7043913

Fabrikant, J. I.

1981-01-01

16

Dangers of Radiation Exposure  

NSDL National Science Digital Library

In the first part of the lesson, students calculate their yearly exposure rate to harmful high-energy radiation and cumulative effects over time. They then use the information to evaluate the various sources of radiation that are of greatest concern for them. In the second part of the lesson, students learn that spacecraft and other objects in space must be concerned with the same kinds of radiation to which humans are exposed. The MESSENGER spacecraft will orbit Mercury and be subjected to much more intense solar radiation than it would near Earth. Students discuss the notion that even though some of the radiation is needed to study the properties of the planet, too much of it can be quite damaging.

American Association for the Advancement of Science (AAAS;)

2005-03-15

17

Widespread Decreased Expression of Immune Function Genes in Human Peripheral Blood Following Radiation Exposure  

PubMed Central

We report a large-scale reduced expression of genes in pathways related to cell-type specific immunity functions that emerges from microarray analysis 48 h after ex vivo ?-ray irradiation (0, 0.5, 2, 5, 8 Gy) of human peripheral blood from five donors. This response is similar to that seen in patients at 24 h after the start of total-body irradiation and strengthens the rationale for the ex vivo model as an adjunct to human in vivo studies. The most marked response was in genes associated with natural killer (NK) cell immune functions, reflecting a relative loss of NK cells from the population. T- and B-cell mediated immunity genes were also significantly represented in the radiation response. Combined with our previous studies, a single gene expression signature was able to predict radiation dose range with 97% accuracy at times from 6–48 h after exposure. Gene expression signatures that may report on the loss or functional deactivation of blood cell subpopulations after radiation exposure may be particularly useful both for triage biodosimetry and for monitoring the effect of radiation mitigating treatments. PMID:24168352

Paul, Sunirmal; Smilenov, Lubomir B.; Amundson, Sally A.

2014-01-01

18

A cell kinetic model of granulopoiesis under radiation exposure: extension from rodents to canines and humans.  

PubMed

As significant ionising radiation exposure will occur during prolonged space travel in future, it is essential to understand their adverse effects on the radiosensitive organ systems that are important for immediate survival of humans, e.g. the haematopoietic system. In this paper, a biomathematical model of granulopoiesis is used to analyse the granulocyte changes seen in the blood of mammalians under acute and continuous radiation exposure. This is one of a set of haematopoietic models that have been successfully utilised to simulate and interpret the experimental data of acute and chronic radiation on rodents. Extension to canine and human systems indicates that the results of the model are consistent with the cumulative experimental and empirical data from various sources, implying the potential to integrate them into one united model system to monitor the haematopoietic response of various species under irradiation. The suppression of granulocytes' level of a space traveller under chronic stress of low-dose irradiation as well as the granulopoietic response when encountering a historically large solar particle event is also discussed. PMID:21196459

Hu, Shaowen; Cucinotta, Francis A

2011-02-01

19

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

Microsoft Academic Search

Uncertainty in estimations of the exposure of non-human biota to ionising radiation may arise from a number of sources including values of the model parameters, empirical data, measurement errors and biases in the sampling. The significance of the overall uncertainty of an exposure assessment will depend on how the estimated dose compares with reference doses used for risk characterisation. In

R. Avila; N. A. Beresford; A. Agüero; R. Broed; J. Brown; M. Iospje; B. Robles; A. Suañez

2004-01-01

20

Nuclear Energy: Radiation Exposure  

NSDL National Science Digital Library

This lesson provides an overview of the sources and potential effects of radiation exposure. Topics include the history of the United States' domestic nuclear power program, the concept of ionizing radiation, and how radiation dosage is measured. There is also discussion of what constitutes a lethal dose of radiation and potential sources of exposure. The lesson includes an activity in which students measure their individual yearly exposures to radiation by making an inventory of lifestyle factors that affect their potential dosage and using an online calculator to sum up the contributions from the various sources.

Pratte, John

21

Radiation Exposure Compensation Program  

NSDL National Science Digital Library

This is the Justice Department's Radiation Exposure Compensation Program homepage. This site features information about the Radiation Exposure Compensation Act, including claimant categories, claim forms, and the Energy Employees Occupational Illness Compensation Program Act. This site also provides a table illustrating a summary of all claims received and compensation paid to date.

U.S. Department of Justice Radiation Exposure Compensation Program

22

HAMLET Human Model MATROSHKA for Radiation Exposure Determination of Astronauts Current status and results  

Microsoft Academic Search

The exploration of space as seen in specific projects from the European Space Agency (ESA) acts as groundwork for human long duration space missions. One of the main constraints for long duration human missions is radiation. The radiation load on astronauts and cosmonauts in space (as for the ISS) is a factor of 100 higher than the natural radiation on

Guenther Reitz; Thomas Berger; Pawel Bilski; Soenke Burmeister; Johannes Labrenz; Luke Hager; Jozsef K. Palfalvi; Michael Hajek; Monika Puchalska; Lembit Sihver

2010-01-01

23

Radiation exposure and pregnancy.  

PubMed

Radiological exposure from nuclear power reactor accidents, transportation of nuclear waste accidents, industrial accidents, or terrorist activity may be a remote possibility, but it could happen. Nurses must be prepared to evaluate and treat pregnant women and infants who have been exposed to radiation, and to have an understanding of the health consequences of a nuclear or radiological incident. Pregnant women and infants are a special group of patients who need consideration when exposed to radiation. Initial care requires thorough assessment and decisions regarding immediate care needs. Ongoing care is based on type and extent of radiation exposure. With accurate, comprehensive information and education, nurses will be better prepared to help mitigate the effects of radiation exposure to pregnant women and infants following a radiological incident. Information about radiation, health effects of prenatal radiation exposure, assessment, patient care, and treatment of pregnant women and infants are presented. PMID:25333800

Labant, Amy; Silva, Christina

2014-01-01

24

Medical Radiation Exposure and Human Carcinogenesis-Genetic and Epigenetic Mechanisms.  

PubMed

Ionizing radiation (IR) is a potential carcinogen. Evidence for the carcinogenic effect of IR radiation has been shown after long-term animal investigations and observations on survivors of the atom bombs in Hiroshima and Nagasaki. However, IR has been widely used in a controlled manner in the medical imaging for diagnosis and monitoring of various diseases and also in cancer therapy. The collective radiation dose from medical imagings has increased six times in the last two decades, and grow continuously day to day. A large number of evidence has revealed the increased cancer risk in the people who had frequently exposed to x-rays, especially in childhood. It has also been shown that secondary malignancy may develop within the five years in cancer survivors who have received radiotherapy, because of IR-mediated damage to healthy cells. In this article, we review the current knowledge about the role of medical x-ray exposure in cancer development in humans, and recently recognized epigenetic mechanisms in IR-induced carcinogenesis. PMID:25256861

Dincer, Yildiz; Sezgin, Zeynep

2014-09-01

25

Modelling human exposure to space radiation with different shielding: the FLUKA code coupled with anthropomorphic phantoms  

Microsoft Academic Search

Astronauts' exposure to the various components of the space radiation field is of great concern for long-term missions, especially for those in deep space such as a possible travel to Mars. Simulations based on radiation transport\\/interaction codes coupled with anthropomorphic model phantoms can be of great help in view of risk evaluation and shielding optimisation, which is therefore a crucial

F. Ballarini; D. Alloni; G. Battistoni; F. Cerutti; A. Ferrari; E. Gadioli; M. V. Garzelli; M. Liotta; A. Mairani; A. Ottolenghi; H. G. Paretzke; V. Parini; M. Pelliccioni; L. Pinsky; P. Sala; D. Scannicchio; S. Trovati; M. Zankl

2006-01-01

26

Dangers of Radiation Exposure  

NSDL National Science Digital Library

This is a lesson about radiation and the various sources of radiation that a spacecraft may encounter in its journey. Learners will calculate their annual exposure to high-energy radiation, identify sources of high-energy radiation, and explain why the near-Mercury environment is a concern for the Mercury MESSENGER mission. This is lesson 2 of 4 in the high school track of a module, titled Staying Cool. Note: the student guide starts on p. 17 of the PDF.

27

Utilization of MAX and FAX human phantoms for space radiation exposure calculations using HZETRN  

NASA Astrophysics Data System (ADS)

To estimate astronaut health risk due to space radiation, one must have the ability to calculate, for known radiation environments external to the body, particle spectra, LET spectra, dose, dose equivalent, or gray equivalent that are averaged over specific organs or tissue types. This may be accomplished using radiation transport software and computational human body tissue models. Historically, NASA scientists have used the HZETRN software to calculate radiation transport through both vehicle shielding materials and body tissue. The Computerized Anatomical Man (CAM) and the Computerized Anatomical Female (CAF) body models, combined with the CAMERA software, have been used for body tissue self-shielding calculations. The CAM and CAF, which were developed in 1973 and 1992, respectively, model the 50th percentile U.S. Air Force male and female and are constructed using individual quadric surfaces that combine to form thousands of solid regions that represent specific tissues and structures within the body. In order to transport an external radiation environment to a point within one of the body models using HZETRN, a directional distribution of the tissues surrounding that point is needed. The CAMERA software is used to "ray trace" the CAM and CAF models, providing the thickness of each tissue type traversed along each of a large number of rays originating at a dose point. More recently, R. Kramer of the Departmento de Energia Nuclear, Universidade Federal de Pernambuco in Brazil and his co-workers developed the Male Adult voXel (MAX) model and the Female Adult voXel (FAX). These voxel-based body models were developed using segmented Computed Tomography (CT) scans of adult cadavers, and the quantities and distributions of various body tissues have been adjusted to match those specified in the International Commission on Radiological Protection (ICRP) reference adult male and female. A new set of tools has been developed to facilitate space radiation exposure calculation using HZETRN and the MAX and FAX models. A new ray tracer was developed for these body models, as was a methodology for evaluating organ-averaged quantities. Both tools are described in this paper and utilized in sample calculations.

Qualls, Garry; Slaba, Tony; Clowdsley, Martha; Blattnig, Steve; Walker, Steven; Simonsen, Lisa

28

Natural background radiation induces cytogenetic radioadaptive response more effectively than occupational exposure in human peripheral blood lymphocytes  

NASA Astrophysics Data System (ADS)

Ramsar, a city in the northern Iran, has the highest level of natural background radiation in the world. It has been clearly shown that low doses of ionising radiation can induce resistance to subsequent higher exposures. This phenomenon is termed radioadaptive response. We have compared induction of cytogenetic radioadaptive response by High Natural Background Radiation (HNBR) in Ramsar and X-ray occupational exposure as conditioning doses in human peripheral blood lymphocytes. 30 healthy control individuals, living in Ramsar but in normal background radiation areas, 15 healthy individuals from Talesh Mahalleh, a region with extraordinary high level of background radiation, and 7 X-ray radiographers working in Ramsar hospital located in normal natural background ionising radiation area were evaluated. Peripheral blood samples were prepared and exposed to challenge dose of 0 and 2 Gy. Lymphocytes were scored using analysis of metaphase, for the presence of chromosomal aberrations. An adaptive response was observed in HNBR and radiation workers groups in comparison with sham controls. A significant increase in adaptive response was observed in the HNBR group if compared with the occupationally exposed group. These findings indicate that both natural background radiation and occupational exposure could induce cytogenetic radioadaptive response and it is more significant regarding to natural background ionising radiation.

Monfared, A. Shabestani; Mozdarani, H.; Amiri, M.

2003-01-01

29

Radiation exposure during ureteroscopy  

SciTech Connect

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

Bagley, D.H.; Cubler-Goodman, A. (Thomas Jefferson Univ., Philadelphia, PA (USA))

1990-12-01

30

HUMAN EXPOSURE ACTIVITY PATTERNS  

EPA Science Inventory

Human activity/uptake rate data are necessary to estimate potential human exposure and intake dose to environmental pollutants and to refine human exposure models. Personal exposure monitoring studies have demonstrated the critical role that activities play in explaining and pre...

31

Assessment of the Technologies for Molecular Biodosimetry for Human Low-Dose Radiation Exposure Symposium  

SciTech Connect

Exposure to ionizing radiation produces few immediate outwardly-visible clinical signs, yet, depending on dose, can severely damage vital physiological functions within days to weeks and produce long-lasting health consequences among survivors. In the event of a radiological accident, the rapid evaluation of the individual absorbed dose is paramount to discriminate the worried but unharmed from those individuals who must receive medical attention. Physical, clinical and biological dosimetry are usually combined for the best dose assessment. However, because of the practical limits of physical and clinical dosimetry, many attempts have been made to develop a dosimetry system based on changes in biological parameters, including techniques for hematology, biochemistry, immunology, cytogenetics, etc. Lymphocyte counts and chromosome aberrations analyses are among the methods that have been routinely used for estimating radiation dose. However, these assays require several days to a week to be completed and therefore cannot be used to obtain a fast estimate of the dose during the first few days after exposure when the information would be most critical for identifying victims of radiation accidents who could benefit the most by medical intervention. The steadily increasing sophistication in our understanding of the early biochemical responses of irradiated cells and tissues provides the opportunity for developing mechanism-based biosignatures of exposure. Compelling breakthroughs have been made in the technologies for genome-scale analysis of cellular transcriptional and proteomic profiles. There have also been major strides in the mechanistic understanding of the early events in DNA damage and radiation damage products, as well as in the cellular pathways that lead to radiation injury. New research with genomic- and proteomic-wide tools is showing that within minutes to hours after exposure to ionizing radiation protein machines are modified and activated, and large-scale changes occur in the gene expression profile involving a broad variety of cell-process pathways after a wide range of both low (<10 cGy) and high dose (>10 cGy) exposures. Evaluation of these potential gene and protein biomarkers for early and late diagnostic information will be critical for determining the efficacy of the signatures to both low and high dose IR exposures. Also needed are approaches that enable rapid handling and processing for mass-casualty and population triage scenarios. Development of in vivo model system will be crucial for validating both the biological and the instrumentation for biodosimetry. Such studies will also help further understanding of the molecular mechanisms of the biological effects of radiation and the differences of responses due to individual genetic variation.

Matthew A. Coleman Ph.D.; Narayani Ramakrishnan, Ph.D.; Sally A. Amundson; James D. Tucker, Ph.D.; Stephen D. Dertinger, Ph.D.; Natalia I. Ossetrova, Ph.D.; Tao Chen

2009-11-16

32

HAMLET -Human Model MATROSHKA for Radiation Exposure Determination of Astronauts -Current status and results  

NASA Astrophysics Data System (ADS)

The exploration of space as seen in specific projects from the European Space Agency (ESA) acts as groundwork for human long duration space missions. One of the main constraints for long duration human missions is radiation. The radiation load on astronauts and cosmonauts in space (as for the ISS) is a factor of 100 higher than the natural radiation on Earth and will further increase should humans travel to Mars. In preparation for long duration space missions it is important to evaluate the impact of space radiation in order to secure the safety of the astronauts and minimize their radiation risks. To determine the radiation risk on humans one has to measure the radiation doses to radiosensitive organs within the human body. One way to approach this is the ESA facility MATROSHKA (MTR), under the scientific and project lead of DLR. It is dedicated to determining the radiation load on astronauts within and outside the International Space Station (ISS), and was launched in January 2004. MTR is currently preparing for its fourth experimental phase inside the Japanese Experimental Module (JEM) in summer 2010. MTR, which mimics a human head and torso, is an anthropomorphic phantom containing over 6000 radiation detectors to determine the depth dose and organ dose distribution in the body. It is the largest international research initiative ever performed in the field of space dosimetry and combines the expertise of leading research institutions around the world, thereby generating a huge pool of data of potentially immense value for research. Aiming at optimal scientific exploitation, the FP7 project HAMLET aims to process and compile the data acquired individually by the participating laboratories of the MATROSHKA experiment. Based on experimental input from the MATROSHKA experiment phases as well as on radiation transport calculations, a three-dimensional model for the distribution of radiation dose in an astronaut's body will be built up. The scientific achievements contribute essentially to radiation risk estimations for future interplanetary space exploration by humans, putting them on a solid experimental and theoretical basis. The talk will give an overview of the current status of the MATROSHKA data evaluation and results and comparisons of the first three MTR experimental phases (MTR-1, 2A and 2B). The HAMLET project is funded by the European Commission under the EUs Seventh Frame-work Programme (FP7) under Project Nr: 218817 and coordinated by the German Aerospace Center (DLR) http://www-fp7-hamlet.eu

Reitz, Guenther; Berger, Thomas; Bilski, Pawel; Burmeister, Soenke; Labrenz, Johannes; Hager, Luke; Palfalvi, Jozsef K.; Hajek, Michael; Puchalska, Monika; Sihver, Lembit

33

Human Exposure Assessement  

Microsoft Academic Search

Humans may be exposed to a variety of substances from multiple exposure routes. In Chapter 5 we will distinguish between exposure\\u000a through the environment (Section 5.2), exposure from use of consumer products (Section 5.3), and exposure at the workplace\\u000a (occupational exposure; Section 5.4). In this chapter information is provided on how to perform an exposure assessment for each of these

J. G. M. Van Engelen; P. J. Hakkinen; C. Money; M. G. J. Rikken; T. G. Vermeire

34

Modelling human exposure to space radiation with different shielding: the FLUKA code coupled with anthropomorphic phantoms  

NASA Astrophysics Data System (ADS)

Astronauts' exposure to the various components of the space radiation field is of great concern for long-term missions, especially for those in deep space such as a possible travel to Mars. Simulations based on radiation transport/interaction codes coupled with anthropomorphic model phantoms can be of great help in view of risk evaluation and shielding optimisation, which is therefore a crucial issue. The FLUKA Monte Carlo code can be coupled with two types of anthropomorphic phantom (a mathematical model and a ''voxel'' model) to calculate organ-averaged absorbed dose, dose equivalent and ''biological'' dose under different shielding conditions. Herein the ''biological dose'' is represented by the average number of ''Complex Lesions'' (CLs) per cell in a given organ. CLs are clustered DNA breaks previously calculated by means of event-by-event track structure simulations at the nm level and integrated on-line into FLUKA, which adopts a condensed-history approach; such lesions have been shown to play a fundamental role in chromosome aberration induction, which in turn can be correlated with carcinogenesis. Examples of calculation results will be presented relative to Galactic Cosmic Rays, as well as to the August 1972 Solar Particle Event. The contributions from primary ions and secondary particles will be shown separately, thus allowing quantification of the role played by nuclear reactions occurring in the shield and in the human body itself. As expected, the SPE doses decrease dramatically with increasing the Al shielding thickness; nuclear reaction products, essentially due to target fragmentation, are of minor importance. A 10 g/cm2 Al shelter resulted to be sufficient to respect the 30-day limits for deterministic effects recommended for missions in Low Earth Orbit. In contrast with the results obtained for SPEs, the calculated GCR doses are almost independent of the Al shield thickness, and the GCR doses to internal organs are not significantly lower than the skin doses. Furthermore, nuclear interactions play a much larger role for GCR than for SPE doses.

Ballarini, F.; Alloni, D.; Battistoni, G.; Cerutti, F.; Ferrari, A.; Gadioli, E.; Garzelli, M. V.; Liotta, M.; Mairani, A.; Ottolenghi, A.; Paretzke, H. G.; Parini, V.; Pelliccioni, M.; Pinsky, L.; Sala, P.; Scannicchio, D.; Trovati, S.; Zankl, M.

2006-05-01

35

Radiation Transport Modeling and Assessment to Better Predict Radiation Exposure, Dose, and Toxicological Effects to Human Organs on Long Duration Space Flights  

NASA Technical Reports Server (NTRS)

NASA's long-range plans include possible human exploratory missions to the moon and Mars within the next quarter century. Such missions beyond low Earth orbit will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and the missions long, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. The focus of this study is radiation exposure to the blood-forming organs of the NASA astronauts. NASA/JSC developed the Phantom Torso Experiment for Organ Dose Measurements which housed active and passive dosimeters that would monitor and record absorbed radiation levels at vital organ locations. This experiment was conducted during the STS-9 I mission in May '98 and provided the necessary space radiation data for correlation to results obtained from the current analytical models used to predict exposure to the blood-forming organs. Numerous models (i.e., BRYNTRN and HZETRN) have been developed and used to predict radiation exposure. However, new models are continually being developed and evaluated. The Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronomy, is to be used and evaluated as a part of the research activity. It is the intent of this research effort to compare the modeled data to the findings from the STS-9 I mission; assess the accuracy and efficiency of this model; and to determine its usefulness for predicting radiation exposure and developing better guidelines for shielding requirements for long duration manned missions.

Denkins, Pamela; Badhwar, Gautam; Obot, Victor

2000-01-01

36

Dose-rate models for human survival after exposure to ionizing radiation  

SciTech Connect

This paper reviews new estimates of the L/sub 50/ in man by Mole and by Rotblat, the biological processes contributing to hematologic death, the collection of animal experiments dealing with hematologic death, and the use of regression analysis to make new estimates of human mortality based on all relevant animal studies. Regression analysis of animal mortality data has shown that mortality is dependent strongly on dose rate, species, body weight, and time interval over which the exposure is delivered. The model has predicted human LD/sub 50/s of 194, 250, 310, and 360 rad to marrow when the exposure time is a minute, an hour, a day, and a week, respectively.

Jones, T.D.; Morris, M.D.; Young, R.W.

1986-01-01

37

Rapid translocation frequency analysis in humans decades after exposure to ionizing radiation.  

PubMed

This paper presents an analysis of the utility of fluorescence in situ hybridization (FISH) with whole-chromosome probes for measurement of the genomic frequency of translocations found in the peripheral blood of individuals exposed to ionizing radiation. First, we derive the equation: Fp = 2.05fp(1-fp)FG, relating the translocation frequency, Fp, measured using FISH to the genomic translocation frequency, FG, where fp is the fraction of the genome covered by the composite probe. We demonstrate the validity of this equation by showing that: (a) translocation detection efficiency predicted by the equation is consistent with experimental data as fp is changed; (b) translocation frequency dose-response curves measured in vitro using FISH agree well with dicentric frequency dose-response curves measured in vitro using conventional cytogenetic procedures; and (c) the genomic translocation frequencies estimated from FISH measurements for 20 Hiroshima A-bomb survivors and four workers exposed to ionizing radiation during the Y-12 criticality accident are approximately the same as the translocation frequencies measured using G-banding. We also show that translocation frequency dose response curves estimated using FISH are similar for Hiroshima A-bomb survivors and for first division lymphocytes irradiated in vitro. We conclude with a discussion of the potential utility of translocation frequency analysis for assessment of the level of acute radiation exposure independent of the time between analysis and exposure. PMID:1353776

Lucas, J N; Awa, A; Straume, T; Poggensee, M; Kodama, Y; Nakano, M; Ohtaki, K; Weier, H U; Pinkel, D; Gray, J

1992-07-01

38

Cytogenetic observations in human peripheral blood leukocytes following in vitro exposure to THz radiation: a pilot study.  

PubMed

Emerging technologies are considering the possible use of Terahertz radiation in different fields ranging from telecommunications to biology and biomedicine. The study of the potential effects of Terahertz radiation on biological systems is therefore an important issue in order to safely develop a variety of applications. This paper describes a pilot study devoted to determine if Terahertz radiation could induce genotoxic effects in human peripheral blood leukocytes. For this purpose, human whole blood samples from healthy donors were exposed for 20 min to Terahertz radiation. Since, to our knowledge, this is the first study devoted to the evaluation of possible genotoxic effects of such radiation, different electromagnetic conditions were considered. In particular, the frequencies of 120 and 130 GHz were chosen: the first one was tested at a specific absorption rate (SAR) of 0.4 mW g-1, while the second one was tested at SAR levels of 0.24, 1.4, and 2 mW g-1. Chromosomal damage was evaluated by means of the cytokinesis block micronucleus technique, which also gives information on cell cycle kinetics. Moreover, human whole blood samples exposed to 130 GHz at SAR levels of 1.4 and 2 mW g-1 were also tested for primary DNA damage by applying the alkaline comet assay immediately after exposure. The results obtained indicate that THz exposure, in the explored electromagnetic conditions, is not able to induce either genotoxicity or alteration of cell cycle kinetics in human blood cells from healthy subjects. PMID:17351499

Zeni, O; Gallerano, G P; Perrotta, A; Romanò, M; Sannino, A; Sarti, M; D'Arienzo, M; Doria, A; Giovenale, E; Lai, A; Messina, G; Scarfì, M R

2007-04-01

39

DEMONSTRATION OF HUMAN EXPOSURE TOOLS  

EPA Science Inventory

The Human Exposure and Atmospheric Sciences Division (HEASD) of the National Exposure Research Laboratory (NERL) conducts research on exposure measurements, human activity patterns, exposure and dose models, and cumulative exposures critical for the Agency to make scientificall...

40

Blood-Based Detection of Radiation Exposure in Humans Based on Novel Phospho-Smc1 ELISA  

PubMed Central

The structural maintenance of chromosome 1 (Smc1) protein is a member of the highly conserved cohesin complex and is involved in sister chromatid cohesion. In response to ionizing radiation, Smc1 is phosphorylated at two sites, Ser-957 and Ser-966, and these phosphorylation events are dependent on the ATM protein kinase. In this study, we describe the generation of two novel ELISAs for quantifying phospho-Smc1Ser-957 and phospho-Smc1Ser-966. Using these novel assays, we quantify the kinetic and biodosimetric responses of human cells of hematological origin, including immortalized cells, as well as both quiescent and cycling primary human PBMC. Additionally, we demonstrate a robust in vivo response for phospho-Smc1Ser-957 and phospho-Smc1Ser-966 in lymphocytes of human patients after therapeutic exposure to ionizing radiation, including total-body irradiation, partial-body irradiation, and internal exposure to 131I. These assays are useful for quantifying the DNA damage response in experimental systems and potentially for the identification of individuals exposed to radiation after a radiological incident. PMID:21388270

Ivey, Richard G.; Moore, Heather D.; Voytovich, Uliana J.; Thienes, Cortlandt P.; Lorentzen, Travis D.; Pogosova-Agadjanyan, Era L.; Frayo, Shani; Izaguirre, Venissa K.; Lundberg, Sally J.; Hedin, Lacey; Badiozamani, Kas Ray; Hoofnagle, Andrew N.; Stirewalt, Derek L.; Wang, Pei; Georges, George E.; Gopal, Ajay K.; Paulovich, Amanda G.

2011-01-01

41

Medical effects of exposure of human beings to fallout radiation from a thermonuclear explosion.  

PubMed

On March 1, 1954, after detonation of a thermonuclear device on Bikini atoll, an unexpected wind shift resulted in the deposition of radioactive fallout on inhabited atolls. The fallout radiation caused fleeting systemic effects, dose-dependent depression of hematopoiesis and skin burns primarily due to the beta ray component of the fission radionuclides. Within a few weeks, hematopoietic recovery was substantial but slight depression of blood counts was maintained for several years. One case of fatal acute myeloblastic leukemia developed in a boy receiving 1.9 Gy as an infant. Cretinism developed in two boys exposed as infants with estimated thyroidal dose in excess of 50 Gy. Chemical hypothyroidism was detected in several persons. Thyroid adenomas and cancer commenced appearance ten years after exposure and became a major long-term medical problem. There have been no late effects attributable to the beta burns 40 years after exposure. Internal contamination from ingestion and inhalation of radionuclides is detectable. The doses are comparable to background levels in the U.S. There is no detectible decrease in longevity of the exposed Marshallese compared to an unexposed Marshallese population. PMID:7488968

Cronkite, E P; Bond, V P; Conard, R A

1995-05-01

42

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

PubMed

Uncertainty in estimations of the exposure of non-human biota to ionising radiation may arise from a number of sources including values of the model parameters, empirical data, measurement errors and biases in the sampling. The significance of the overall uncertainty of an exposure assessment will depend on how the estimated dose compares with reference doses used for risk characterisation. In this paper, we present the results of a study of the uncertainty in estimation of the exposure of non-human biota using some of the models and parameters recommended in the FASSET methodology. The study was carried out for semi-natural terrestrial, agricultural and marine ecosystems, and for four radionuclides (137Cs, 239Pu, 129I and 237Np). The parameters of the radionuclide transfer models showed the highest sensitivity and contributed the most to the uncertainty in the predictions of doses to biota. The most important ones were related to the bioavailability and mobility of radionuclides in the environment, for example soil-to-plant transfer factors, the bioaccumulation factors for marine biota and the gut uptake fraction for terrestrial mammals. In contrast, the dose conversion coefficients showed low sensitivity and contributed little to the overall uncertainty. Radiobiological effectiveness contributed to the overall uncertainty of the dose estimations for alpha emitters although to a lesser degree than a number of transfer model parameters. PMID:15700701

Avila, R; Beresford, N A; Agüero, A; Broed, R; Brown, J; Iospje, M; Robles, B; Suañez, A

2004-12-01

43

Epidemiology of accidental radiation exposures.  

PubMed Central

Much of the information on the health effects of radiation exposure available to date comes from long-term studies of the atomic bombings in Hiroshima and Nagasaki. Accidental exposures, such as those resulting from the Chernobyl and Kyshtym accidents, have as yet provided little information concerning health effects of ionizing radiation. This paper will present the current state of our knowledge concerning radiation effects, review major large-scale accidental radiation exposures, and discuss information that could be obtained from studies of accidental exposures and the types of studies that are needed. PMID:8781398

Cardis, E

1996-01-01

44

Dose Response for Chromosome Aberrations in Human Lymphocytes and Fibroblasts after Exposure to Very Low Doses of High LET Radiation  

NASA Technical Reports Server (NTRS)

The relationship between biological effects and low doses of absorbed radiation is still uncertain, especially for high LET radiation exposure. Estimates of risks from low-dose and low-dose-rates are often extrapolated using data from Japanese atomic bomb survivors with either linear or linear quadratic models of fit. In this study, chromosome aberrations were measured in human peripheral blood lymphocytes and normal skin fibroblasts cells after exposure to very low dose (1-20 cGy) of 170 MeV/u Si-28- ions or 600 MeV/u Fe-56-ions. Chromosomes were analyzed using the whole chromosome fluorescence in situ hybridization (FISH) technique during the first cell division after irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving greater than 2 breaks in 2 or more chromosomes). The curves for doses above 10 cGy were fitted with linear or linear-quadratic functions. For Si-28- ions no dose response was observed in the 2-10 cGy dose range, suggesting a non-target effect in this range.

Hada, M.; George, Kerry; Cucinotta, Francis A.

2011-01-01

45

Epidemiology of accidental radiation exposures  

Microsoft Academic Search

Much of the information on the health effects of radiation exposure available to date comes from long-term studies of the atomic bombings in Hiroshima and Nagasaki. Accidental exposures, such as those resulting from the Chernobyl and Kyshtym accidents, have as yet provided little information concerning health effects of ionizing radiation. This paper will present the current state of our knowledge

Cardis

1996-01-01

46

Analysis of cellular response by exposure to acute or chronic radiation in human lymphoblastoid TK-6 cells  

NASA Astrophysics Data System (ADS)

To clarify the biological effects of low-dose rate radiation on human health for long-term stay in space, we analyzed the induction of apoptosis and apoptosis-related gene expression after irradiation with different dose-rate in human lymphoblastoid TK-6 cells harboring wild-type p53 gene. We irradiated TK-6 cells by X-ray at 1.5 Gy (1 Gy/min) and then sampled at 25 hr after culturing. We also irradiated by gamma-ray at 1.5 Gy (1 mGy/min) and then sampled immediately or 25 hr after irradiation. For DNA ladder analysis, we extracted DNA from these samples and electrophoresed with 2% agarose gel. In addition, we extracted mRNA from these samples for DNA-array analysis. mRNA from non-irradiated cells was used as a control. After labeling the cDNA against mRNA with [? -33P]-dCTP and hybridizing onto DNA array (Human Apoptosis Expression Array, R&D Systems), we scanned the profiles of the spots by a phosphorimager (BAS5000, FUJI FILM) and calculated using a NIH Image program. The data of each DNA-array were normalized with eight kinds of house keeping genes. We analyzed the expression level of apoptosis-related genes such as p53-related, Bcl-2 family, Caspase family and Fas-related genes. DNA ladders were obviously detected in the cells exposed to a high dose-rate radiation. We detected the induction of the gene expression of apoptosis-promotive genes. In contrast, almost no apoptosis was observed in the cells exposed to the chronic radiation at a low dose-rate. In addition, we detected the induction of the gene expression of apoptosis-suppressive genes as compared with apoptosis promotive-genes immediately after chronic irradiation. These results lead the importance of biological meaning of exposure to radiation at low dose-rate from an aspect of carcinogenesis. Finally, the effects of chronic irradiation become a highly important issue in space radiation biology for human health.

Ohnishi, T.; Yasumoto, J.; Takahashi, A.; Ohnishi, K.

47

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

Microsoft Academic Search

The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits

Schoten; Eert

1998-01-01

48

Cytogenetic responses to ionizing radiation exposure of human fibroblasts with knocked-down expressions of various DNA damage signaling genes  

NASA Astrophysics Data System (ADS)

Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have demonstrated that genes with up-regulated expression induced by IR may play important roles in DNA damage sensing, cell cycle checkpoint and chromosomal repair, the relationship between the regulation of gene expression by IR and its impact on cytogenetic responses to ionizing radiation has not been systematically studied. Here, the expression of 25 genes selected based on their transcriptional changes in response to IR or from their known DNA repair roles were individually knocked down by siRNA transfection in human fibroblast cells. Chromosome aberrations (CA) and micronuclei (MN) formation were measured as the cytogenetic endpoints. Our results showed that the yields of MN and/or CA formation were significantly increased by suppressed expression of some of the selected genes in DSB and other DNA repair pathways. Knocked-down expression of other genes showed significant impact on cell cycle progression, possibly because of severe impairment of DNA damage repair. Of these 11 genes that affected the cytogenetic response, 9 were up-regulated in the cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulating the biological consequences after IR. Failure to express these IR-responsive genes, such as by gene mutation, could seriously change the outcome of the post IR scenario and lead to carcinogenesis.

Zhang, Ye; Rohde, Larry; Wu, Honglu

49

Dose Response for Chromosome Aberrations in Human Lymphocytes and Fibroblasts After Exposure to Very Low Dose of High Let Radiation  

NASA Technical Reports Server (NTRS)

The relationship between biological effects and low doses of absorbed radiation is still uncertain, especially for high LET radiation exposure. Estimates of risks from low-dose and low-dose-rates are often extrapolated using data from Japanese atomic bomb survivor with either linear or linear quadratic models of fit. In this study, chromosome aberrations were measured in human peripheral blood lymphocytes and normal skin fibroblasts cells after exposure to very low dose (0.01 - 0.20 Gy) of 170 MeV/u Si-28 ions or 600 MeV/u Fe-56 ions, including doses where on average less than one direct ion traversal per cell nucleus occurs. Chromosomes were analyzed using the whole-chromosome fluorescence in situ hybridization (FISH) technique during the first cell division after irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). The responses for doses above 0.1 Gy (more than one ion traverses a cell) showed linear dose responses. However, for doses less than 0.1 Gy, both Si-28 ions and Fe-56 ions showed a dose independent response above background chromosome aberrations frequencies. Possible explanations for our results are non-targeted effects due to aberrant cell signaling [1], or delta-ray dose fluctuations [2] where a fraction of cells receive significant delta-ray doses due to the contributions of multiple ion tracks that do not directly traverse cell nuclei where chromosome aberrations are scored.

Hada, M.; George, K.; Chappell, L.; Cucinotta, F. A.

2011-01-01

50

Radiation Exposure and Pregnancy  

MedlinePLUS

... on the Health Physics Society "Ask the Experts" Web site. 3 Glossary Dose A general term used ... 2010. Radiation Answers, www.radiationanswers.org is a Web site that answers questions about radiation and was ...

51

Environmental Radiation Exposures  

Cancer.gov

DCEG is investigating cancer risks among populations exposed to radiation from environmental sources, such as nuclear reactor accidents and fallout from weapons testing.   Atomic Bomb Survivors Childhood Leukemia and Background Radiation Semipalatinsk

52

Biological effects of low levels of radiation exposure. [Radiation hazards to man from radioactive consumer products  

Microsoft Academic Search

Some general perspective is provided concerning the orders of radiation dose equivalent levels associated with exposure of human populations to ionizing radiations from consumer products. This is followed by considerations of the biological effects and risks of low levels of radiation exposure. Some consumer products emit low-LET (i.e., low linear energy transfer) radiations beyond their confines and these penetrating radiations

Casarett

1977-01-01

53

HUMAN LEUKOCYTE FUNCTIONS AND THE U.S. SAFETY STANDARD FOR EXPOSURE TO RADIO-FREQUENCY RADIATION  

EPA Science Inventory

Human mononuclear leukocytes were exposed to microwaves at energies relevant to current public safety recommendations. No detectable effects on viability or function of the leukocytes resulted from exposure to microwaves at specific absorption rates up to 4 milliwatts per millili...

54

On the use of quality factors and fluence to dose rate conversion in human radiation exposures  

NASA Technical Reports Server (NTRS)

It is shown that various combinations of numbers and factors arrive at estimates of dose and dose effectiveness from values of fluence; but as yet it has not been possible to use biological data with the same degree of precision to estimate the physical data. It would seem that the most reasonable way to use the human data that exist is to apply them as far as possible to the human animal as a whole.

Sondhaus, C. A.

1972-01-01

55

Human fibroblasts expressing hTERT show remarkable karyotype stability even after exposure to ionizing radiation  

Microsoft Academic Search

Ectopic expression of telomerase results in an immortal phenotype in various types of normal cells, including primary human fibroblasts. In addition to its role in telomere lengthening, telomerase has now been found to have various functions, including the control of DNA repair, chromatin modification, and the control of expression of genes involved in cell cycle regulation. The investigations on the

L. M. Pirzio; M.-A. Freulet-Marrière; Y. Bai; B. Fouladi; J. P. Murnane; L. Sabatier; C. Desmaze

2004-01-01

56

Occupational Radiation Exposures  

Cancer.gov

DCEG researchers are studying cancer risks among populations who are occupationally exposed to radiation. Chernobyl Clean-up Workers Mayak Nuclear Facility Workers U.S. Radiologic Technologists Interventional Fluoroscopists Print This Page Occupational

57

Cardiovascular complications of radiation exposure.  

PubMed

The cardiovascular sequelae of radiation exposure are an important cause of morbidity and mortality following radiation therapy for cancer, as well as after exposure to radiation after atomic bombs or nuclear accidents. In the United States, most of the data on radiation-induced heart disease (RIHD) come from patients treated with radiation therapy for Hodgkin disease and breast cancer. Additionally, people exposed to radiation from the atomic bombs in Hiroshima and Nagasaki, Japan, and the Chernobyl, Ukraine, nuclear accident have an increased risk of cardiovascular disease. The total dose of radiation, as well as the fractionation of the dose, plays an important role in the development of RIHD. All parts of the heart are affected, including the pericardium, vasculature, myocardium, valves, and conduction system. The mechanism of injury is complex, but one major mechanism is injury to endothelium in both the microvasculature and coronary arteries. This likely also contributes to damage and fibrosis within the myocardium. Additionally, various inflammatory and profibrotic cytokines contribute to injury. Diagnosis and treatment are not significantly different from those for conventional cardiovascular disease; however, screening for heart disease and lifelong cardiology follow-up is essential in patients with past radiation exposure. PMID:25290729

Finch, William; Shamsa, Kamran; Lee, Michael S

2014-01-01

58

Cytogenetic Response to Ionizing Radiation Exposure in Human Fibroblasts with Suppressed Expression of Non-DSB Repair Genes  

NASA Technical Reports Server (NTRS)

Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in radiation-induced chromosome aberrations and micronuclei formation. In the study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequencies of micronuclei (MN) formation and chromosome aberrations were measured to determine the efficiency of cytogenetic repair, and the fraction of bi-nucleated cells in the MN analysis was used as a marker for cell cycle progression. In response to gamma radiation, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR-induced biological consequences. Furthermore, eight non-DBS repair genes showed involvement in regulating DSB repair, indicating that successful DSB repair requires both DSB repair mechanisms and non-DSB repair systems.

Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Hammond, Dianne; Mehta, Satish K.; Jeevarajan, Antony S.; Pierson, Duane L.; Wu, Honglu

2009-01-01

59

[The epileptiform reactions of the human brain to prolonged exposure to low-dose ionizing radiation].  

PubMed

1125 inhabitants of Slavutich city where workers of the Chernobyl Atomic Power Station and their families live, have been electroencephalographically examined. The reasons for the medical check-up involved specific complaints of a headache, dizziness, nightmares, early waking up in the mornings and sometimes seizures. Disorders of the bioelectrical activity of paroxysmal nature were revealed in 286 cases (197 children of 3-17 years, 99 adults of 18-50 years). The epileptiform findings seem to be related to the ionising radiation. The latency for a high (single or repeated) dose may be short (or minimal), and for a long-term effect of small doses--3-6 years. The latency was more or less similar and depended on a number of biophysical factors for the majority of the examined inhabitants of Slavutich city: children as well as adults (including those who work at the Chernobyl Atomic Power Station). PMID:7531070

Danilov, V M; Pozdeev, V K

1994-06-01

60

Radiation exposure in the moon environment  

NASA Astrophysics Data System (ADS)

During a stay on the moon humans are exposed to elevated radiation levels due to the lack of substantial atmospheric and magnetic shielding compared to the Earth's surface. The absence of magnetic and atmospheric shielding allows cosmic rays of all energies to impinge on the lunar surface. Beside the continuous exposure to galactic cosmic rays (GCR), which increases the risk of cancer mortality, exposure through particles emitted in sudden nonpredictable solar particle events (SPE) may occur. SPEs show an enormous variability in particle flux and energy spectra and have the potential to expose space crew to life threatening doses. On Earth, the contribution to the annual terrestrial dose of natural ionizing radiation of 2.4 mSv by cosmic radiation is about 1/6, whereas the annual exposure caused by GCR on the lunar surface is roughly 380 mSv (solar minimum) and 110 mSv (solar maximum). The analysis of worst case scenarios has indicated that SPE may lead to an exposure of about 1 Sv. The only efficient measure to reduce radiation exposure is the provision of radiation shelters. Measurements on the lunar surface performed during the Apollo missions cover only a small energy band for thermal neutrons and are not sufficient to estimate the exposure. Very recently some data were added by the Radiation Dose Monitoring (RADOM) instrument operated during the Indian Chandrayaan Mission and the Cosmic Ray Telescope (CRaTER) instrument of the NASA LRO (Lunar Reconnaisance Orbiter) mission. These measurements need to be complemented by surface measurements. Models and simulations that exist describe the approximate radiation exposure in space and on the lunar surface. The knowledge on the radiation exposure at the lunar surface is exclusively based on calculations applying radiation transport codes in combination with environmental models. Own calculations are presented using Monte-Carlo simulations to calculate the radiation environment on the moon and organ doses on the surface of the moon for an astronaut in an EVA suit and are compared with measurements. Since it is necessary to verify/validate such calculations with measurement on the lunar surface, a description is given of a radiation detector for future detailed surface measurements. This device is proposed for the ESA Lunar Lander Mission and is capable to characterize the radiation field concerning particle fluencies, dose rates and energy transfer spectra for ionizing particles and to measure the dose contribution of secondary neutrons.

Reitz, Guenther; Berger, Thomas; Matthiae, Daniel

2012-12-01

61

Human exposure to aluminium.  

PubMed

Human activities have circumvented the efficient geochemical cycling of aluminium within the lithosphere and therewith opened a door, which was previously only ajar, onto the biotic cycle to instigate and promote the accumulation of aluminium in biota and especially humans. Neither these relatively recent activities nor the entry of aluminium into the living cycle are showing any signs of abating and it is thus now imperative that we understand as fully as possible how humans are exposed to aluminium and the future consequences of a burgeoning exposure and body burden. The aluminium age is upon us and there is now an urgent need to understand how to live safely and effectively with aluminium. PMID:23982047

Exley, Christopher

2013-10-01

62

Human exposure to nickel.  

PubMed

In order of abundance in the earth's crust, nickel ranks as the 24th element and has been detected in different media in all parts of the biosphere. Thus, humans are constantly exposed to this ubiquitous element, though in variable amounts. The average natural nickel exposure from food in the past has probably been somewhat, but not much, below current levels. Nickel is a useful metal, particularly in various alloys, in batteries and in nickel-plating. Nickel compounds are used especially as catalysts and pigments. In nickel-producing or nickel-using industries, about 0.2% of the work force may be exposed to considerable amounts of airborne nickel. In addition, nickel release, e.g., into cutting oils, and skin contact with nickel-containing or nickel-plated tools and other items may add to an occupational nickel hazard. Occupational exposures may lead to the retention of 100 micrograms of nickel per day. Environmental nickel levels depend particularly on natural sources, pollution from nickel-manufacturing industries and airborne particles from combustion of fossil fuels. Absorption from atmospheric nickel pollution is of minor concern. Vegetables usually contain more nickel than do other food items; high levels have been found in legumes, spinach, lettuce and nuts. Certain products, such as baking powder and cocoa powder, have been found to contain excessive amounts of nickel, perhaps related to nickel leaching during the manufacturing process. Soft drinking-water and acid beverages may dissolve nickel from pipes and containers. Leaching or corrosion processes may contribute significantly to the oral nickel intake, occasionally up to 1 mg/day. Scattered studies indicate a highly variable dietary intake of nickel, but most averages are about 200-300 micrograms/day. In addition, skin contact to a multitude of metal objects may be of significance to the large number of individuals suffering from contact dermatitis and nickel allergy. Finally, nickel alloys are often used in nails and prostheses for orthopaedic surgery, and various sources may contaminate intravenous fluids. Thus, human nickel exposure originates from a variety of sources and is highly variable. Occupational nickel exposure is of major significance, and leaching of nickel may add to dietary intakes and to cutaneous exposures. Preventive efforts should mainly be directed towards adequate control of these exposure sources. PMID:6241927

Grandjean, P

1984-01-01

63

[Radiation exposure and thyroid cancer].  

PubMed

Thyroid cancer is the most common malignant tumor of the endocrine system. The most frequent type of thyroid malignancy is papillary carcinoma. Thyroid cancer's incidence rates have increased over the last three decades throughout the world. Numerous studies have documented that radiation exposure is a well-established risk factor for the thyroid cancer. It has been reported that exposure to external medical radiation or to external and internal radiation from atomic bomb explosions, nuclear tests or nuclear accidents leads to an increased risk for thyroid cancer. The risk of thyroid cancer is maximal during the first years of life and decreases with increasing age at exposure due to morphologic and functional heterogeneity in the thyroid tissue of children and adults. Also it has been indicated that iodine deficiency increases the risk of the thyroid cancer related to radioactive iodines in case of exposure to radioactive iodines in childhood and the stable iodine supplementation reduces this risk. Ionizing radiation produces a range of mutations in irradiated cells of the thyroid. The prevalence of RET/PTC mutations is significantly higher in papillary carcinomas from childhood patients with the precedent history of radiation. PMID:23064295

Cannizzaro, Matteo Angelo; Veroux, Massimiliano; Costanzo, Mario; Buffone, Antonino; Okatyeva, Valeriya

2012-01-01

64

Induction of genomic instability in TK6 human lymphoblasts exposed to 137Cs gamma radiation: comparison to the induction by exposure to accelerated 56Fe particles  

NASA Technical Reports Server (NTRS)

The induction of genomic instability in TK6 human lymphoblasts by exposure to (137)Cs gamma radiation was investigated by measuring the frequency and characteristics of unstable clones isolated approximately 36 generations after exposure. Clones surviving irradiation and control clones were analyzed for 17 characteristics including chromosomal aberrations, growth defects, alterations in response to a second irradiation, and mutant frequencies at the thymidine kinase and Na(+)/K(+) ATPase loci. Putative unstable clones were defined as those that exhibited a significant alteration in one or more characteristics compared to the controls. The frequency and characteristics of the unstable clones were compared in clones exposed to (137)Cs gamma rays or (56)Fe particles. The majority of the unstable clones isolated after exposure to either gamma rays or (56)Fe particles exhibited chromosomal instability. Alterations in growth characteristics, radiation response and mutant frequencies occurred much less often than cytogenetic alterations in these unstable clones. The frequency and complexity of the unstable clones were greater after exposure to (56)Fe particles than to gamma rays. Unstable clones that survived 36 generations after exposure to gamma rays exhibited increases in the incidence of dicentric chromosomes but not of chromatid breaks, whereas unstable clones that survived 36 generations after exposure to (56)Fe particles exhibited increases in both chromatid and chromosome aberrations.

Evans, Helen H.; Horng, Min-Fen; Ricanati, Marlene; Diaz-Insua, M.; Jordan, Robert; Schwartz, Jeffrey L.

2003-01-01

65

Sarcoma risk after radiation exposure  

PubMed Central

Sarcomas were one of the first solid cancers to be linked to ionizing radiation exposure. We reviewed the current evidence on this relationship, focusing particularly on the studies that had individual estimates of radiation doses. There is clear evidence of an increased risk of both bone and soft tissue sarcomas after high-dose fractionated radiation exposure (10?+?Gy) in childhood, and the risk increases approximately linearly in dose, at least up to 40?Gy. There are few studies available of sarcoma after radiotherapy in adulthood for cancer, but data from cancer registries and studies of treatment for benign conditions confirm that the risk of sarcoma is also increased in this age-group after fractionated high-dose exposure. New findings from the long-term follow-up of the Japanese atomic bomb survivors suggest, for the first time, that sarcomas can be induced by acute lower-doses of radiation (<5?Gy) at any age, and the magnitude of the risk is similar to that observed for other solid cancers. While there is evidence that individuals with certain rare familial genetic syndromes predisposing to sarcoma, particularly Nijmegen Breakage Syndrome, are particularly sensitive to the effects of high dose radiation, it is unclear whether this is also true in very low-dose settings (<0.1?Gy). The effects of common low-penetrance alleles on radiosensitivity in the general population have not been well-characterized. Some evidence suggests that it may be possible to identify radiation-induced sarcomas by a distinct molecular signature, but this work needs to be replicated in several dose settings, and the potential role of chemotherapy and tumor heterogeneity needs to be examined in more detail. In summary, radiation exposure remains one of the few established risk factors for both bone and soft tissue sarcomas. Similar to many other cancers children have the highest risks of developing a radiation-related sarcoma. Efforts to limit unnecessary high-dose radiation exposure, particularly in children, therefore remain important given the high fatality rates associated with this disease. PMID:23036235

2012-01-01

66

Risks of occupational exposure to optical radiation.  

PubMed

During the past 40 years a wide body of biomedical research has been conducted to understand the factors which influence injury to optical radiation-particularly with respect to the eye. A primary motivation for much of this research has been the advent of lasers, since focal damage of the retina from a collimated beam exposure is possible at some distance. A wide range of research studies provided the basis for establishing human exposure limits for ultraviolet and infrared radiation as well as for intense visible light. The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has published guidelines for human exposure, and these are available at no cost from the ICNIRP website (http://www. icnirp.org). Laser Maximum Permissible Exposure (MPE) limits used in international safety standards, such as those of the International Electrotechnical Commission (IEC) are based upon ICNIRP guidelines. Practical laser safety standards and regulations have evolved to promote the safe design and use of laser products. As a result of newer laser applications and increased knowledge of the biological effects, MPEs have been revised a number of times. Despite the existence of safety standards and regulations, accidental eye injuries from lasers still occur. Accidental exposure to welding arcs and intense lights occur more fequently, but the consequential loss of vision is much less, with permanent effects rare. Accidental human exposure information also adds to our understanding of ultraviolet, blue-light and laser induced retinal injury. Accidents are most frequently attributed to the lack of understanding of hazards and a failure to follow established safe work practices. PMID:17017352

Sliney, D H

2006-01-01

67

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

SciTech Connect

The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits centers around the appropriateness of extrapolation methods (What can be inferred from data on high exposure levels and on experimental animals?). Generally speaking, there is a lack of direct information on the health effects of low levels of exposure. Effects at these levels cannot usually be detected by means of traditional animal experiments or epidemiological research. The capacity of these analytical instruments to distinguish between ''signal'' and ''noise'' is inadequate in most cases. Annex B of this report contains a brief outline of the difficulties and the established methods for tackling this problem. In spite of this, the hope exists that the posited weak signals, if they are indeed present, can be detected by other means. The search will have to take place on a deeper level. In other words, effort must be made to discover what occurs at underlying levels of biological organization when organisms are exposed to low doses of radiation or substances. Molecular and cell biology provide various methods and techniques which give an insight into the processes within the cell. This results in an increase in the knowledge about the molecular and cellular effects of exposure to agents, or stated differently, the working mechanisms which form the basis of the health effects. Last year, the Health Council considered that the time was ripe to take stock of the state of knowledge in this field. To this end, an international working conference was held from 19 to 21 October 1997, entitled ''Health Effects of Low Level Exposures: Scientific Developments and Perspectives for Risk Assessment''. The central question was the extent to which the sometimes fast-growing knowledge about molecular and cellular effects offers the desired basis for extrapolation. Against this setting, a number of more specific questions which have been hotly debated for some time were also addressed. One of the primary questions concerned the traditional but increasingly questioned division between stochastic and non-stochastic working agents, and the corresponding division between exposure-effect relations without a threshold and with a threshold. Thoughts were also exchanged on what is often referred to as hormesis: the notion that low levels of exposure could actually improve health. For the purpose of illuminating the many aspects of these issues, experts from a number of areas were invited. In addition to this, three agents were selected to serve as points of crystallization for the general debate: ionizing radiation, ultraviolet (UV) radiation and dioxins. The present report calls attention to a selection of issues which emerged during the discussions on the above-mentioned central topic. Various more detailed questions and the wider context of the points considered are described at greater length in the enclosed conference report and in the background documents attached to the report. What follows is a series of considerations regarding the scientific basis for the derivation of recommended exposure levels, viewed in the light of current procedures and against the background of the work of the Health Council. In the preparation of the following comments and recommendations, various Dutch experts have been consulted.

Schoten, Eert

1998-11-26

68

Effects of prenatal exposure to ionizing radiation  

SciTech Connect

Prenatal exposure to ionizing radiation induces some effects that are seen at birth and others that cannot be detected until later in life. Data from A-bomb survivors in Hiroshima and Nagasaki show a diminished number of births after exposure under 4 wk of gestational age. Although a wide array of congenital malformations has been found in animal experimentation after such exposure to x rays, in humans only small head size (exposure at 4-17 wk) and mental retardation (exposure primarily at 8-15 wk) have been observed. In Hiroshima, small head size occurred after doses of 0.10-0.19 Gy or more, and an excess of mental retardation at 0.2-0.4 Gy or more. Intelligence test scores were reduced among A-bomb survivors exposed at 8-15 wk of gestational age by 21-29 IQ points per Gy. Other effects of in-utero exposure to atomic radiation include long-lasting complex chromosome abnormalities.

Miller, R.W. (National Cancer Institute, Bethesda, MD (USA))

1990-07-01

69

Nuclear accumulation of cyclin D1 following long-term fractionated exposures to low-dose ionizing radiation in normal human diploid cells.  

PubMed

Cyclin D1 is a mitogenic sensor that responds to growth signals from the extracellular environment and regulates the G 1-to-S cell cycle transition. When cells are acutely irradiated with a single dose of 10 Gy, cyclin D1 is degraded, causing cell cycle arrest at the G 1/S checkpoint. In contrast, cyclin D1 accumulates in human tumor cells that are exposed to long-term fractionated radiation (0.5 Gy/fraction of X-rays). In this study we investigated the effect of fractionated low-dose radiation exposure on cyclin D1 localization in 3 strains of normal human fibroblasts. To specifically examine the nuclear accumulation of cyclin D1, cells were treated with a hypotonic buffer containing detergent to remove cytoplasmic cyclin D1. Proliferating cell nuclear antigen (PCNA) immunofluorescence was used to identify cells in S phase. With this approach, we observed S-phase nuclear retention of cyclin D1 following low-dose fractionated exposures, and found that cyclin D1 nuclear retention increased with exposure time. Cells that retained nuclear cyclin D1 were more likely to have micronuclei than non-retaining cells, indicating that the accumulation of nuclear cyclin D1 was associated with genomic instability. Moreover, inhibition of the v-akt murine thymoma viral oncogene homolog (AKT) pathway facilitated cyclin D1 degradation and eliminated cyclin D1 nuclear retention in cells exposed to fractionated radiation. Thus, cyclin D1 may represent a useful marker for monitoring long-term effects associated with exposure to low levels of radiation. PMID:24583467

Shimura, Tsutomu; Hamada, Nobuyuki; Sasatani, Megumi; Kamiya, Kenji; Kunugita, Naoki

2014-04-15

70

Occupational exposure to natural radiation.  

PubMed

Natural sources of radiation can make an important contribution to the exposures of people at work. Two areas of interest are work with minerals having elevated concentrations of activity and work in buildings where radon daughter concentrations are elevated. The Euratom Directive on ionising radiation requires that the handling of radioactive substances be reported to national authorities. National authorities may waive this requirement where the activity per unit mass is below 100 Bq g-1, or for solid natural radioactive substances, 500 Bq g-1. An investigation was undertaken in five factories to determine whether work with minerals having levels of natural activity below these might lead to significant doses. Models based on the data collected were used to relate the activity in the minerals to the effective dose equivalent arising from gamma radiation, inhalation of radon daughters, and intake of long-lived activity. These assessments show that the activity concentration at which exposures to airborne dust could lead to doses equal to one-tenth of the dose limit for workers are 0.3 Bq g-1 for thorium-232 and 1 Bq g-1 for uranium-238. Above these values, radiological supervision may be necessary. In a separate study, measurements of radon daughter concentrations were made in seventy workplaces. Concentrations in some premises approached or exceeded the derived air concentration for occupational exposure. The highest concentrations were found in premises with low ventilation rates. PMID:4081708

Dixon, D W

1985-10-01

71

Radiation effects on human heredity.  

PubMed

In experimental organisms such as fruit flies and mice, increased frequencies in germ cell mutations have been detected following exposure to ionizing radiation. In contrast, there has been no clear evidence for radiation-induced germ cell mutations in humans that lead to birth defects, chromosome aberrations, Mendelian disorders, etc. This situation exists partly because no sensitive and practical genetic marker is available for human studies and also because the number of people exposed to large doses of radiation and subsequently having offspring was small until childhood cancer survivors became an important study population. In addition, the genome of apparently normal individuals seems to contain large numbers of alterations, including dozens to hundreds of nonfunctional alleles. With the number of mutational events in protein-coding genes estimated as less than one per genome after 1 gray (Gy) exposure, it is unsurprising that genetic effects from radiation have not yet been detected conclusively in humans. PMID:23988120

Nakamura, Nori; Suyama, Akihiko; Noda, Asao; Kodama, Yoshiaki

2013-01-01

72

Comparative study of cell cycle kinetics and induction of apoptosis or necrosis after exposure of human Mono Mac 6 cells to radiofrequency radiation.  

PubMed

The possible harmful effects of radiofrequency electromagnetic fields (RF EMFs) are controversial. We have used human Mono Mac 6 cells to investigate the influence of RF EMFs in vitro on cell cycle alterations and BrdU uptake, as well as the induction of apoptosis and necrosis in human Mono Mac 6 cells, using flow cytometry after exposure to a 1,800 MHz, 2 W/kg specific absorption rate (SAR), GSM-DTX signal for 12 h. No statistically significant differences in the induction of apoptosis or necrosis, cell cycle kinetics, or BrdU uptake were detected after RF EMF exposure compared to sham or incubator controls. However, in the positive control cells treated with gliotoxin and PMA (phorbol 12 myristate-13 acetate), a significant increase in apoptotic and necrotic cells was seen. Cell cycle analysis or BrdU incorporation for 72 h showed no differences between RF EMF- or sham-exposed cells, whereas PMA treatment induced a significant accumulation of cells in G(0)/G(1)-phase and a reduction in S-phase cells. RF EMF radiation did not induce cell cycle alterations or changes in BrdU incorporation or induce apoptosis and necrosis in Mono Mac 6 cells under the exposure conditions used. PMID:16953672

Lantow, M; Viergutz, T; Weiss, D G; Simkó, M

2006-09-01

73

Radiation Effect on Human Tissue  

NASA Technical Reports Server (NTRS)

Predicting the occurrence of human cancer following exposure of an epidemiologic population to any agent causing genetic damage is a difficult task. To an approximation, this is because the uncertainty of uniform exposure to the damaging agent, and the uncertainty of uniform processing of that damage within a complex set of biological variables, degrade the confidence of predicting the delayed expression of cancer as a relatively rare event within clinically normal individuals. This situation begs the need for alternate controlled experimental models that are predictive for the development of human cancer following exposures to agents causing genetic damage. Such models historically have not been of substantial proven value. It is more recently encouraging, however, that developments in molecular and cell biology have led to an expanded knowledge of human carcinogenesis, and of molecular markers associated with that process. It is therefore appropriate to consider new laboratory models developed to accomodate that expanded knowledge in order to assess the cancer risks associated with exposures to genotoxic agents. When ionizing radiation of space is the genotoxic agent, then a series of additional considerations for human cancer risk assessment must also be applied. These include the dose of radiation absorbed by tissue at different locations in the body, the quality of the absorbed radiation, the rate at which absorbed dose accumulates in tissue, the way in which absorbed dose is measured and calculated, and the alterations in incident radiation caused by shielding materials. It is clear that human cancer risk assessment for damage caused by ionizing radiation is a multidisciplinary responsibility, and that within this responsibility no single discipline can hold disproportionate sway if a risk assessment model of radiation-induced human cancer is to be developed that has proven value. Biomolecular and cellular markers from the work reported here are considered for use in assessing human cancer risk related to exposure to space radiation. This potential use must be integrated within the specified multidisciplinary context in order to create a new tool of molecular epidemiology that can hopefully then realistically assess this cancer risk.

Richmond, Robert C.; Cruz, Angela; Bors, Karen; Curreri, Peter A. (Technical Monitor)

2002-01-01

74

Non-Target Effect for Chromosome Aberrations in Human Lymphocytes and Fibroblasts After Exposure to Very Low Doses of High LET Radiation  

NASA Technical Reports Server (NTRS)

The relationship between biological effects and low doses of absorbed radiation is still uncertain, especially for high LET radiation exposure. Estimates of risks from low-dose and low-dose-rates are often extrapolated using data from Japanese atomic bomb survivor with either linear or linear quadratic models of fit. In this study, chromosome aberrations were measured in human peripheral blood lymphocytes and normal skin fibroblasts cells after exposure to very low dose (.01 - 0.2 Gy) of 170 MeV/u Si-28-ions or 600 MeV/u Fe-56-ions. Chromosomes were analyzed using the whole chromosome fluorescence in situ hybridization (FISH) technique during the first cell division after irradiation, and chromosome aberrations were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving >2 breaks in 2 or more chromosomes). The curves for doses above 0.1 Gy were more than one ion traverses a cell showed linear dose responses. However, for doses less than 0.1 Gy, Si-28-ions showed no dose response, suggesting a non-targeted effect when less than one ion traversal occurs. Additional findings for Fe-56 will be discussed.

Hada, Megumi; George, Kerry A.; Cucinotta, F. A.

2011-01-01

75

M-FISH Analysis of Chromosome Aberrations in Human Fibroblast Cells After In Vitro Exposure to Low- and High-LET Radiation  

NASA Technical Reports Server (NTRS)

The recently commercialized multiplex fluorescence in situ hybridization (m-FISH) technique, which allows human chromosomes to be painted in 24 different colors, was used to analyze chromosome aberrations in diploid human fibroblast cells after in vitro radiation exposure. Confluent flasks of a normal primary fibroblast cell line (AG 1522) were irradiated at high dose rates with either gamma rays or 200 MeV/nucleon Fe ions (LET = 440 keV/micron), incubated at 37 C for 24 hours after exposure, and subsequently subcultured. A chemically induced premature chromosome condensation technique was used to collect chromosome samples 32 hours after subculture. Results showed that the fraction of exchanges which were identified as complex, i.e. involving misrejoining of three or more DSB, were higher in the Fe-irradiated samples compared with the gamma-irradiated samples, as has been shown previously using FISH with one or two painted chromosomes . The ratios of complex/simple type exchanges were similar for samples irradiated with 0.7 Gy and 3 Gy of Fe ions, although exchanges involving five or more breaks were found only in 3 Gy irradiated samples. The fraction of incomplete exchanges was also higher in Fe- than gamma-irradiated samples. Data on the distribution of individual chromosome involvement in interchromosomal exchanges will be presented.

Wu, Honglu; Furusawa, Yoshiya; George, Kerry; Kawata, Tetsuya; Cucinotta, Francis

2002-01-01

76

Ionizing radiation exposure of LDEF  

NASA Technical Reports Server (NTRS)

The Long Duration Exposure Facility (LDEF) was launched into orbit by the Space Shuttle 'Challenger' mission 41C on 6 April 1984 and was deployed on 8 April 1984. The original altitude of the circular orbit was 258.5 nautical miles (479 km) with the orbital inclination being 28.5 degrees. The 21,500 lb NASA Langley Research Center satellite, having dimensions of some 30x14 ft was one of the largest payloads ever deployed by the Space Shuttle. LDEF carried 57 major experiments and remained in orbit five years and nine months (completing 32,422 orbits). It was retrieved by the Shuttle 'Columbia' on January 11, 1990. By that time, the LDEF orbit had decayed to the altitude of 175 nm (324 km). The experiments were mounted around the periphery of the LDEF on 86 trays and involved the representation of more than 200 investigators, 33 private companies, 21 universities, seven NASA centers, nine Department of Defense laboratories and eight foreign countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures, power and propulsion. The data contained in the LDEF mission represents an invaluable asset and one which is not likely to be duplicated in the foreseeable future. The data and the subsequent knowledge which will evolve from the analysis of the LDEF experiments will have a very important bearing on the design and construction of the Space Station Freedom and indeed on other long-term, near-earth orbital space missions. A list of the LDEF experiments according to experiment category and sponsor is given, as well as a list of experiments containing radiation detectors on LDEF including the LDEF experiment number, the title of the experiment, the principal investigator, and the type of radiation detectors carried by the specific experiment.

Benton, E. V. (editor); Heinrich, W. (editor)

1990-01-01

77

Administration of recombinant human IL11 after supralethal radiation exposure promotes survival in mice: interactive effect with thrombopoietin.  

PubMed

In the present study, we evaluated the therapeutic potential of recombinant human IL11 in lethally irradiated C57BL6/J mice exposed to gamma rays. IL11 administered for 5 consecutive days beginning 2 h after total-body irradiation with 8 or 9 Gy 60Co gamma rays resulted in a significant increase in 30-day survival. When IL11 was administered, only a slight improvement in the hematopoietic status (both blood cell counts and progenitor cells) was observed after an 8-Gy exposure, and no improvement in hematopoietic reconstitution was observed after 9 Gy total-body irradiation. The enhancement of fibrinogen in the plasma of irradiated animals suggested the importance of infections in the death of animals. IL11 was able to limit the increase in fibrinogen levels. However, prevention of bacterial infections by antibiotic treatment, although it delayed death, was ineffective in promoting survival either in placebo-treated and IL11-treated mice. IL11 was administered along with thrombopoietin (TPO) or bone marrow transplantation to limit the hematopoietic syndrome, in addition to antibiotic treatment. When IL11 was combined with TPO, a potent stimulator of hematopoiesis, the survival of animals which had been irradiated with 10 Gy 137Cs gamma rays was increased significantly compared to those treated with IL11 or TPO alone. Furthermore, an interactive effect of TPO and IL11 on hematopoietic reconstitution was observed. Similarly, IL11 in combination with bone marrow transplantation enhanced survival after 15 Gy 137Cs gamma rays. These data suggest that the effect of IL11 on the hematopoietic system is only moderate when it is used alone in supralethally irradiated mice but that the effect is improved in the presence of a hematopoietic growth factor or bone marrow transplantation. PMID:12005542

Van der Meeren, Anne; Mouthon, Marc-André; Gaugler, Marie-Hélène; Vandamme, Marie; Gourmelon, Patrick

2002-06-01

78

INSTRUCTION CONCERNING PRENATAL RADIATION EXPOSURE A. INTRODUCTION  

E-print Network

be instructed in the health protection problems associated with exposure to radioactive material or radiation.311, FAC, places different radiation dose limits on declared pregnant workers than on adult workers, in accordance with 64E-5.902 before they are allowed to work with radioactive materials and/or radiation

Slatton, Clint

79

IDENTIFYING SOURCES OF HUMAN EXPOSURE  

EPA Science Inventory

Air pollution from ambient sources continues to adversely impact human health in the United States. A fundamental goal for EPA is to implement air quality standards and regulations that reduce health risks associated with exposures to criteria pollutants and air toxics. However...

80

Solar radiation and human health  

NASA Astrophysics Data System (ADS)

The Sun has played a major role in the development of life on Earth. In Western culture, people are warned against Sun exposure because of its adverse effects: erythema, photoimmunosuppression, photoageing, photocarcinogenesis, cataracts and photokeratitis. However, Sun exposure is also beneficial, since moderate doses give beneficial physiological effects: vitamin D synthesis, reduction of blood pressure and mental health. Shortage of Sun exposure may be even more dangerous to human health than excessive exposure. Avoiding Sun exposure leads to vitamin D deficiency which is associated not only with rickets and osteomalacia, but also with increased risk of cardiovascular disease, multiple sclerosis, rheumatoid arthritis, diabetes, influenza, many types of cancer and adverse pregnancy outcomes. Solar radiation induces nitric oxide release in tissue and immediate pigment darkening which certainly play important roles, although these are still unknown. Action spectra relevant for health are described. We will also review what is known about spectral and intensity variations of terrestrial solar radiation as well as its penetration through the atmosphere and into human skin and tissue.

Juzeniene, Asta; Brekke, Pål; Dahlback, Arne; Andersson-Engels, Stefan; Reichrath, Jörg; Moan, Kristin; Holick, Michael F.; Grant, William B.; Moan, Johan

2011-06-01

81

Cell Type-dependent Gene Transcription Profile in Three Dimensional Human Skin Tissue Model Exposed to Low Doses of Ionizing Radiation: Implications for Medical Exposures  

Microsoft Academic Search

The concern over possible health risks from exposures to low doses of ionizing radiation has been driven largely by the increase in medical exposures, the routine implementation of X-ray backscatter devices for airport security screening, and, most recently, the nuclear incident in Japan. Due to a paucity of direct epidemiological data at very low doses, cancer risk must be estimated

Claere H. Freiin von Neubeck; Harish Shankaran; Norman J. Karin; Paula M. Kauer; William B. Chrisler; Xihai Wang; Robert J. Robinson; Katrina M. Waters; Susan C. Tilton; Marianne B. Sowa

2012-01-01

82

Fetal radiation exposure: Is monitoring really needed?  

PubMed Central

The effect of fetal radiation during endoscopic retrograde cholangiopancreatography (ERCP) on pregnant women is a very interesting topic. Smith et al recently estimated the fetal radiation exposure in pregnant women undergoing ERCPs using thermoluminescent dosimeters (TLDs). The authors concluded that TLDs are unnecessary during ERCP with modified techniques. We believe that an extreme caution is needed in clinical practice before drawing such conclusions when they are not strongly supported by enough experimental evidence. Therefore, we recommend that fetal radiation exposure be monitored in clinical practice by using dosimeters, bearing in mind that all relevant techniques to control and minimize the exposure must be applied. PMID:23951391

Di Leo, Milena; Arcidiacono, Paolo Giorgio

2013-01-01

83

Toxicologic methods: controlled human exposures.  

PubMed Central

The assessment of risk from exposure to environmental air pollutants is complex, and involves the disciplines of epidemiology, animal toxicology, and human inhalation studies. Controlled, quantitative studies of exposed humans help determine health-related effects that result from breathing the atmosphere. The major unique feature of the clinical study is the ability to select, control, and quantify pollutant exposures of subjects of known clinical status, and determine their effects under ideal experimental conditions. The choice of outcomes to be assessed in human clinical studies can be guided by both scientific and practical considerations, but the diversity of human responses and responsiveness must be considered. Subjects considered to be among the most susceptible include those with asthma, chronic obstructive lung disease, and cardiovascular disease. New experimental approaches include exposures to concentrated ambient air particles, diesel engine exhaust, combustion products from smoking machines, and experimental model particles. Future investigations of the health effects of air pollution will benefit from collaborative efforts among the disciplines of epidemiology, animal toxicology, and human clinical studies. PMID:10931779

Utell, M J; Frampton, M W

2000-01-01

84

SOURCES OF HUMAN EXPOSURE TO AIRBORNE PAH  

EPA Science Inventory

Personal exposures to airborne particulate polycyclic aromatic hydrocarbons (PAHs) were studied in several populations in the US, Japan, and Czech Republic. Personal exposure monitors, developed for human exposure biomonitoring studies were used to collect fine particles (...

85

Radiation Exposure from Medical Exams and Procedures  

MedlinePLUS

... was prepared recently for the Health Physics Society Web site ( http://hps.org/hpspublications/ articles/Benefitsofmedradexposures.html). ... in the United States each person receives about 3.0 mSv (300 mrem) of radiation exposure from background ...

86

[Transgenerational effects of parental exposure to ionizing radiation].  

PubMed

The deleterious effects of exposure to ionizing radiation on human health have been known for many years. The main long term effect of this exposure is an increase in the risk for developing benign and malignant tumors in the exposed population. This review summarizes the existing data on the possible effects of ionizing radiation on the second generation, focusing on cancer risk. The two mechanisms through which parents' exposure to radiation could affect their children's health are intrauterine exposure of the fetus and preconception exposure of the gonads. Intrauterine exposure to ionizing radiation has teratogenic and carcinogenic effects. Most case-control studies have shown a 40-50% increase in the risk of cancer following intrauterine exposure to medical diagnostic radiation at doses of 10-20mGy. Results of these studies have greatly contributed to the strict radiation protection guidelines at pregnancy existing today. Although animal studies have shown that gonadal exposure to high doses can cause heritable genetic changes, this effect has not been demonstrated unequivocally in epidemiological studies. A case-control study suggested an association between preconception irradiation and leukemia/non-Hodgkin's lymphoma in children of male workers at a nuclear plant in the UK (the Gardner hypothesis). This report generated substantial interest and research; however, subsequent occupational studies failed to confirm the association. Negative results were also reported in studies of the atomic bomb survivors and survivors of childhood cancer. In summary, epidemiological studies do not support the association between gonadal exposure to ionizing radiation and the development of cancer and other genetic diseases among offspring. PMID:16900743

Sadetzki, Siegal; Flint-Richter, Pazit

2006-07-01

87

Tissue reactions under chronic exposure to ionizing radiation  

Microsoft Academic Search

Reviewed are radiobiological data on the emergence of tissue reactions that may determine the course and outcome of human\\u000a chronic irradiation. The main mechanisms of the reaction of hemopoietic, immune, reproductive, endocrine, respiratory systems\\u000a and skin to long-term and fractionated exposure to ionizing radiation are considered. The problem of developing a new approach\\u000a to threshold dose estimation for chronic exposure

A. V. Akleyev

2010-01-01

88

Radiation exposure modeling and project schedule visualization  

SciTech Connect

This paper discusses two applications using IGRIP (Interactive Graphical Robot Instruction Program) to assist environmental remediation efforts at the Department of Energy (DOE) Hanford Site. In the first application, IGRIP is used to calculate the estimated radiation exposure to workers conducting tasks in radiation environments. In the second, IGRIP is used as a configuration management tool to detect interferences between equipment and personnel work areas for multiple projects occurring simultaneously in one area. Both of these applications have the capability to reduce environmental remediation costs by reducing personnel radiation exposure and by providing a method to effectively manage multiple projects in a single facility.

Jaquish, W.R.; Enderlin, V.R. [ICF Kaiser Hanford Co., Richland, WA (United States)

1995-10-01

89

Occupational radiation exposure and pregnancy in orthopaedics.  

PubMed

Radiological imaging is necessary in a wide variety of trauma and elective orthopaedic operations. The evolving orthopaedic workforce includes an increasing number of pregnant workers. Current legislation in the United Kingdom, Europe and United States allows them to choose their degree of participation, if any, with fluoroscopic procedures. For those who wish to engage in radiation-prone procedures, specific regulations apply to limit the radiation dose to the pregnant worker and unborn child. This paper considers those aspects of radiation protection, the potential effects of exposure to radiation in pregnancy and the dose of radiation from common orthopaedic procedures, which are important for safe clinical practice. PMID:22219242

Uzoigwe, C E; Middleton, R G

2012-01-01

90

Risks and management of radiation exposure.  

PubMed

High-energy ionizing radiation is harmful. Low-level exposure sources include background, occupational, and medical diagnostics. Radiation disaster incidents include radioactive substance accidents and nuclear power plant accidents. Terrorism and international conflict could trigger intentional radiation disasters that include radiation dispersion devices (RDD) (a radioactive dirty bomb), deliberate exposure to industrial radioactive substances, nuclear power plant sabotage, and nuclear weapon detonation. Nuclear fissioning events such as nuclear power plant incidents and nuclear weapon detonation release radioactive fallout that include radioactive iodine 131, cesium 137, strontium 90, uranium, plutonium, and many other radioactive isotopes. An RDD dirty bomb is likely to spread only one radioactive substance, with the most likely substance being cesium 137. Cobalt 60 and strontium 90 are other RDD dirty bomb possibilities. In a radiation disaster, stable patients should be decontaminated to minimize further radiation exposure. Potassium iodide (KI) is useful for iodine 131 exposure. Prussian blue (ferric hexacyanoferrate) enhances the fecal excretion of cesium via ion exchange. Ca-DTPA (diethylenetriaminepentaacetic acid) and Zn-DTPA form stable ionic complexes with plutonium, americium, and curium, which are excreted in the urine. Amifostine enhances chemical and enzymatic repair of damaged DNA. Acute radiation sickness ranges in severity from mild to lethal, which can be assessed by the nausea/vomiting onset/duration, complete blood cell count findings, and neurologic symptoms. PMID:24201986

Yamamoto, Loren G

2013-09-01

91

Radiation exposure to anaesthetists during endovascular procedures.  

PubMed

Medical radiation exposure increases the likelihood of cataract formation. A personal dosimeter was attached to the left temple of 77 anaesthetists during 45 endovascular aortic aneurysm repairs and 32 interventional neuroradiology procedures. Compared with interventional neuroradiology, the median (IQR [range]) total radiation dose emitted by fluoroscopic equipment was significantly lower during endovascular aortic aneurysm repair (4175 (3127-5091 [644-9761]) mGy than interventional neuroradiology (1420 (613-2424 [165-10 840]) mGy, p < 0.001). However, radiation exposure to the anaesthetist's temple was significantly greater during endovascular aortic aneurysm repair (15 (6-41 [1-109]) ?Sv) than interventional neuroradiology (4 (2-8 [0-67]) ?Sv, p < 0.001). These data suggest that anaesthetists at our institution would have to deliver anaesthesia for ~1300 endovascular aortic aneurysm repairs and ~5000 interventional neuroradiology cases annually to exceed the general occupational limits, and ~10 000 endovascular aortic aneurysm repairs and ~37 500 interventional neuroradiology cases to exceed the ocular exposure limits recommended by the International Commission on Radiological Protection. Nevertheless, anaesthetists should be aware of the risk of ocular radiation exposure, and reduce this by limiting the time of exposure, increasing the distance from the source of radiation, and shielding. PMID:25267714

Arii, T; Uchino, S; Kubo, Y; Kiyama, S; Uezono, S

2015-01-01

92

Occupational radiation exposure to the surgeon.  

PubMed

Increased use of intraoperative fluoroscopy exposes the surgeon to significant amounts of radiation. The average yearly exposure of the public to ionizing radiation is 360 millirems (mrem), of which 300 mrem is from background radiation and 60 mrem from diagnostic radiographs. A chest radiograph exposes the patient to approximately 25 mrem and a hip radiograph to 500 mrem. A regular C-arm exposes the patient to approximately 1,200 to 4,000 mrem/min. The surgeon may receive exposure to the hands from the primary beam and to the rest of the body from scatter. Recommended yearly limits of radiation are 5,000 mrem to the torso and 50,000 mrem to the hands. Exposure to the hands may be higher than previously estimated, even from the mini C-arm. Potential decreases in radiation exposure can be accomplished by reduced exposure time; increased distance from the beam; increased shielding with gown, thyroid gland cover, gloves, and glasses; beam collimation; using the low-dose option; inverting the C-arm; and surgeon control of the C-arm. PMID:15712984

Singer, Gordon

2005-01-01

93

Investigating the effect of using granite and marble as a building material on the radiation exposure of humans.  

PubMed

The aim of this study was to comprehensively study the radiological hazards of granite and marble used as a building material in Egypt. The activity concentrations of (226)Ra, (232)Th and (40)K were determined using high-resolution hyper-pure germanium detectors in 25 samples of different types of commercially available granite and marble. The measured activity concentrations for these natural radionuclides were compared with the reported data for Egypt and other countries. In order to assess the radiological impact, the radiation hazard parameters such as radium equivalent activity (Ra(eq)) and hazard level index (I(?)) were calculated. The internal and external dose rates due to natural radionuclides in granite and marble were also calculated. The data obtained were considered as helpful  in regulating the use of building materials in Egypt. PMID:22496209

Ebaid, Y Y; Bakr, W F

2012-09-01

94

Intestinal microbiota as novel biomarkers of prior radiation exposure.  

PubMed

There is an urgent need for rapid, accurate, and sensitive diagnostic platforms to confirm exposure to radiation and estimate the dose absorbed by individuals subjected to acts of radiological terrorism, nuclear power plant accidents, or nuclear warfare. Clinical symptoms and physical dosimeters, even when available, do not provide adequate diagnostic information to triage and treat life-threatening radiation injuries. We hypothesized that intestinal microbiota act as novel biomarkers of prior radiation exposure. Adult male Wistar rats (n = 5/group) received single or multiple fraction total-body irradiation of 10.0 Gy and 18.0 Gy, respectively. Fresh fecal pellets were obtained from each rat prior to (day 0) and at days 4, 11, and 21 post-irradiation. Fecal microbiota composition was determined using microarray and quantitative PCR (polymerase chain reaction) analyses. The radiation exposure biomarkers consisted of increased 16S rRNA levels of 12 members of the Bacteroidales, Lactobacillaceae, and Streptococcaceae after radiation exposure, unchanged levels of 98 Clostridiaceae and Peptostreptococcaceae, and decreased levels of 47 separate Clostridiaceae members; these biomarkers are present in human and rat feces. As a result of the ubiquity of these biomarkers, this biomarker technique is non-invasive; microbiota provide a sustained level of reporting signals that are increased several-fold following exposure to radiation, and intestinal microbiota that are unaffected by radiation serve as internal controls. We conclude that intestinal microbiota serve as novel biomarkers of prior radiation exposure, and may be able to complement conventional chromosome aberrational analysis to significantly enhance biological dose assessments. PMID:22439602

Lam, Vy; Moulder, John E; Salzman, Nita H; Dubinsky, Eric A; Andersen, Gary L; Baker, John E

2012-05-01

95

Diverse delayed effects in human lymphoblastoid cells surviving exposure to high-LET (56)Fe particles or low-LET (137)Cs gamma radiation  

NASA Technical Reports Server (NTRS)

To obtain information on the origin of radiation-induced genomic instability, we characterized a total of 166 clones that survived exposure to (56)Fe particles or (137)Cs gamma radiation, isolated approximately 36 generations after exposure, along with their respective control clones. Cytogenetic aberrations, growth alterations, responses to a second irradiation, and mutant frequencies at the Na(+)/K(+) ATPase and thymidine kinase loci were determined. A greater percentage of clones that survived exposure to (56)Fe particles exhibited instability (defined as clones showing one or more outlying characteristics) than in the case of those that survived gamma irradiation. The phenotypes of the unstable clones that survived exposure to (56)Fe particles were also qualitatively different from those of the clones that survived gamma irradiation. A greater percentage (20%) of the unstable clones that survived gamma irradiation than those that survived exposure to (56)Fe particles (4%) showed an altered response to the second irradiation, while an increase in the percentage of clones that had an outlying frequency of ouabain-resistant and thymidine kinase mutants was more evident in the clones exposed to (56)Fe particles than in those exposed to gamma rays. Growth alterations and increases in dicentric chromosomes were found only in clones with more than one alteration. These results underscore the complex nature of genomic instability and the likelihood that radiation-induced genomic instability arises from different original events.

Evans, H. H.; Horng, M. F.; Ricanati, M.; Diaz-Insua, M.; Jordan, R.; Schwartz, J. L.

2001-01-01

96

HUMAN POPULATION EXPOSURES TO MIREX AND KEPONE  

EPA Science Inventory

Human exposures to mirex and kepone are assessed in this study. Three major paths of exposure are examined: ingestion through the food chain, inhalation of atmospheric mirex and kepone, and exposure through drinking water. Exposure through the food chain appears to be the most pr...

97

Tissues may adapt to radiation exposure  

SciTech Connect

French scientists discovered radioactivity and developed vaccination, so it is perhaps appropriate that a prominent French cancer specialist should be promoting the idea of a radiation vaccination effect - or radiation adaptation, as he prefers to call it. Raymond Latarjet, of the Institut Curie in Paris, maintains that recent studies at the gene level are showing evidence that with low doses of radiation, there is time for a cell repair mechanism to take effect, and that this seems to provide some protection against subsequent exposure to high doses. He cited experiments in his laboratory in which exposure to a dose of 4 Gy (400 rad) had, predictably, produced a large number of gene mutations in a specimen, but the number of mutations was less than half that number in a specimen that had been exposed to a dose of 0.02 Gy some six hours before exposure to the 4 Gy.

NONE

1993-08-01

98

DOE occupational radiation exposure 1996 report  

SciTech Connect

The goal of the US Department of Energy (DOE) is to conduct its radiological operations to ensure the health and safety of all DOE employees including contractors and subcontractors. The DOE strives to maintain radiation exposures to its workers below administrative control levels and DOE limits and to further reduce these exposures and releases to levels that are ``As Low As Reasonably Achievable`` (ALARA). The DOE Occupational Radiation Exposure Report, 1996 provides summary and analysis of the occupational radiation exposure received by individuals associated with DOE activities. The DOE mission includes stewardship of the nuclear weapons stockpile and the associated facilities, environmental restoration of DOE and precursor agency sites, and energy research. Collective exposure at DOE has declined by 80% over the past decade due to a cessation in opportunities for exposure during the transition in DOE mission from weapons production to cleanup, deactivation and decommissioning, and changes in reporting requirements and dose calculation methodology. In 1996, the collective dose decreased by 10% from the 1995 value due to decreased doses at five of the seven highest-dose DOE sites. For 1996, these sites attributed the reduction in collective dose to the completion of several decontamination and decommissioning projects, reduced spent fuel storage activities, and effective ALARA practices. This report is intended to be a valuable tool for managers in their management of radiological safety programs and commitment of resources.

NONE

1996-12-31

99

HUMAN EXPOSURE MODELING: CONCEPTS, METHODS, AND TOOLS  

EPA Science Inventory

Understanding human exposure is critical when estimating the occurrence of deleterious effects that could follow contact with environmental contaminants. For many pollutants, the intensity, duration, frequency, route, and timing of exposure is highly variable, particularly whe...

100

Radiation Metabolomics: Identification of Minimally Invasive Urine Biomarkers for Gamma-Radiation Exposure in Mice  

PubMed Central

Gamma-radiation exposure has both short- and long-term adverse health effects. The threat of modern terrorism places human populations at risk for radiological exposures, yet current medical countermeasures to radiation exposure are limited. Here we describe metabolomics for ?-radiation biodosimetry in a mouse model. Mice were ?-irradiated at doses of 0, 3 and 8 Gy (2.57 Gy/min), and urine samples collected over the first 24 h after exposure were analyzed by ultra-performance liquid chromatography–time-of-flight mass spectrometry (UPLC–TOFMS). Multivariate data were analyzed by orthogonal partial least squares (OPLS). Both 3- and 8-Gy exposures yielded distinct urine metabolomic phenotypes. The top 22 ions for 3 and 8 Gy were analyzed further, including tandem mass spectrometric comparison with authentic standards, revealing that N-hexanoylglycine and ?-thymidine are urinary biomarkers of exposure to 3 and 8 Gy, 3-hydroxy-2-methylbenzoic acid 3-O-sulfate is elevated in urine of mice exposed to 3 but not 8 Gy, and taurine is elevated after 8 but not 3 Gy. Gene Expression Dynamics Inspector (GEDI) self-organizing maps showed clear dose–response relationships for subsets of the urine metabolome. This approach is useful for identifying mice exposed to ? radiation and for developing metabolomic strategies for noninvasive radiation biodosimetry in humans. PMID:18582157

Tyburski, John B.; Patterson, Andrew D.; Krausz, Kristopher W.; Slavík, Josef; Fornace, Albert J.; Gonzalez, Frank J.; Idle, Jeffrey R.

2008-01-01

101

DOE 2012 Occupational Radiation Exposure October 2013  

SciTech Connect

The U.S. Department of Energy (DOE) Office of Analysis within the Office of Health, Safety and Security (HSS) publishes the annual DOE Occupational Radiation Exposure Report to provide an overview of the status of radiation protection practices at DOE (including the National Nuclear Security Administration [NNSA]). The DOE 2012 Occupational Radiation Exposure Report provides an evaluation of DOE-wide performance regarding compliance with Title 10, Code of Federal Regulations (C.F.R.), Part 835, Occupational Radiation Protection dose limits and as low as reasonably achievable (ALARA) process requirements. In addition, the report provides data to DOE organizations responsible for developing policies for protection of individuals from the adverse health effects of radiation. The report provides a summary and an analysis of occupational radiation exposure information from the monitoring of individuals involved in DOE activities. Over the past 5-year period, the occupational radiation exposure information is analyzed in terms of aggregate data, dose to individuals, and dose by site. As an indicator of the overall amount of radiation dose received during the conduct of operations at DOE, the report includes information on collective total effective dose (TED). The TED is comprised of the effective dose (ED) from external sources, which includes neutron and photon radiation, and the internal committed effective dose (CED), which results from the intake of radioactive material into the body. The collective ED from photon exposure decreased by 23% between 2011 and 2012, while the neutron dose increased by 5%. The internal dose components of the collective TED decreased by 7%. Over the past 5-year period, 99.99% of the individuals receiving measurable TED have received doses below the 2 roentgen equivalent in man (rems) (20 millisievert [mSv]) TED administrative control level (ACL), which is well below the DOE regulatory limit of 5 rems (50 mSv) TED annually. The occupational radiation exposure records show that in 2012, DOE facilities continued to comply with DOE dose limits and ACLs and worked to minimize exposure to individuals. The DOE collective TED decreased 17.1% from 2011 to 2012. The collective TED decreased at three of the five sites with the largest collective TED. u Idaho Site – Collective dose reductions were achieved as a result of continuing improvements at the Advanced Mixed Waste Treatment Project (AMWTP) through the planning of drum movements that reduced the number of times a container is handled; placement of waste containers that created highradiation areas in a centralized location; and increased worker awareness of high-dose rate areas. In addition, Idaho had the largest decrease in the total number of workers with measurable TED (1,143 fewer workers). u Hanford Site (Hanford) – An overall reduction of decontamination and decommissioning (D&D) activities at the Plutonium Finishing Plant (PFP) and Transuranic (TRU) retrieval activities resulted in collective dose reductions. u Savannah River Site (SRS) – Reductions were achieved through ALARA initiatives employed site wide. The Solid Waste Management Facility used extended specialty tools, cameras and lead shield walls to facilitate removal of drums. These tools and techniques reduce exposure time through improved efficiency, increase distance from the source of radiation by remote monitoring, shield the workers to lower the dose rate, and reduce the potential for contamination and release of material through repacking of waste. Overall, from 2011 to 2012, there was a 19% decrease in the number of workers with measurable dose. Furthermore, due to a slight decrease in both the DOE workforce (7%) and monitored workers (10%), the ratio of workers with measurable doses to monitored workers decreased to 13%. Another primary indicator of the level of radiation exposure covered in this report is the average measurable dose, which normalizes the collective dose over the population of workers who actually received a measurable dose. The average measurable TED in

none,

2012-02-02

102

Uncertainty and relative risks of radiation exposure  

Microsoft Academic Search

Exposure to ionizing radiation in a nonmilitary emergency is likely to alarm those persons exposed and their families. Not only is the outcome uncertain, but the risks are difficult to convey. This communication discusses uncertainties in short-term outcome and long-term effects, as well as means of conveying the magnitude of risks to patients and their families. It emphasizes that the

S. J. Adelstein

1987-01-01

103

Ultraviolet Radiation Exposure and Cancer Risks  

Cancer.gov

Cancers of the skin (e.g. melanoma, basal cell carcinoma, and squamous cell carcinoma) are the most common cancers in the United States, constituting over one million diagnosed cases every year, and the primary risk factor is exposure to ultraviolet radiation

104

Geldanamycin Analog 17-DMAG Limits Apoptosis in Human Peripheral Blood Cells by Inhibition of p53 Activation and its Interaction with Heat-Shock Protein 90 kDa after Exposure to Ionizing Radiation  

PubMed Central

Exposure to ionizing radiation induces p53, and its inhibition improves mouse survival. We tested the effect of 17-dimethylamino-ethylamino-17-demethoxygeldanamycin (17-DMAG) on p53 expression and function after radiation exposure. 17-DMAG, a heat-shock protein 90 (Hsp90) inhibitor, protects human T cells from ionizing radiation-induced apoptosis by inhibiting inducible nitric oxide synthase (iNOS) and subsequent caspase-3 activation. Using ex vivo human peripheral blood mononuclear cells, we found that ionizing radiation increased p53 accumulation, acute p53 phosphorylation, Bax expression and caspase-3/7 activation in a radiation dose- and time postirradiation-dependent manner. 17-DMAG inhibited these increases in a concentration-dependent manner (IC50 = 0.93 ± 0.01 µM). Using in vitro models, we determined that inhibition of p53 by genetic knockout resulted in lower levels of caspase-3/7 activity 1 day after irradiation and enhanced survival at 10 days. Analysis of p53–Hsp90 interaction in ex vivo cell lysates indicated that the binding between the two molecules occurred after irradiation but 17-DMAG prevented the binding. Taken together, these results suggest the presence of p53 phosphorylation and Hsp90-dependent p53 stabilization after acute irradiation. Hsp90 inhibitors such as 17-DMAG may prove useful with radiation-based cancer therapy as well as for general radioprotection. PMID:21663398

Fukumoto, Risaku; Kiang, Juliann G.

2014-01-01

105

Annual occupational exposure to ultraviolet radiation in central Queensland.  

PubMed

The purpose of this study was to determine annual occupational exposure to UV radiation by measurement and derive ambient exposure fractions for an entire year that could be applied in the human exposure model. Using polysulphone the daily occupational erythema effective solar ultraviolet radiation exposure at selected body sites of Australia Post mail delivery personnel and physical education teachers were measured over an 18-mo period on a daily basis in the Rockhampton (lat. 23.5 degrees S) region. The daily exposures were summed to estimate an annual exposure for these occupations in this region. For the Australia Post mail delivery personnel, who had very little change to the posture or route during delivery, the annual mean estimates of exposure to erythema effective solar irradiance for the chest, hands, and back were in the range of 192+/-27 kJ m(-2), 388+/-45 kJ m(-2), and 283+/-32 kJ m(-2), respectively. Physical education teachers had varied duties on a day-to-day basis and many changes in their posture and outdoor locations where the exposure occurred. Their annual mean exposure on the vertex (hat), chest, shoulder, thigh, and back were in the range 340+/-71 kJ m(-2), 140+/-28 kJ m(-2), 180+/-40 kJ m(-2), 129+/-24 kJ m(-2), and 212+/-42 kJ m(-2), respectively. The annual exposure range for erythema effective solar irradiance at different body sites during the experimental period was between 120 and 440 kJ m(-2) for the two occupational groups. These exposures greatly exceed the National Health and Medical Research Council occupational standard limit of 30 J m(-2) for daily exposure, which indicates the need for additional protective measures. The ambient exposure was also measured and used to compute ambient exposure fractions for the different body sites over an entire year, which are useful for model calculations on human exposure and assess increase in risk of n on melanoma skin cancer. PMID:11669207

Vishvakarman, D; Wong, J C; Boreham, B W

2001-11-01

106

Extracellular matrix alterations in conventional renal cell carcinomas by tissue microarray profiling influenced by the persistent, long-term, low-dose ionizing radiation exposure in humans  

Microsoft Academic Search

The present study was carried out in order to examine molecular alterations of extracellular matrix (ECM), associated with cell–cell communication in conventional (clear-cell) renal cell carcinomas (cRCCs) influenced by persistent long-term, low-dose ionizing radiation (IR) exposure to patients living more than 19 years after the Chernobyl accident in Cesium 137 (137Cs)-contaminated areas of Ukraine. The ECM major components such as fibronectin,

Alina Romanenko; Luisa Morell-Quadreny; David Ramos; Valentin Nepomnyaschiy; Alexander Vozianov; Antonio Llombart-Bosch

2006-01-01

107

Medical exposure to radiation and thyroid cancer.  

PubMed

In 2008, the worldwide estimated age-standardised incidence rates for thyroid cancer incidence were 4.7 and 1.5 per 100,000 women and men, respectively. Thyroid cancer's overall contribution to the worldwide cancer burden is relatively small, but incidence rates have increased over the last three decades throughout the world. This trend has been hypothesised to reflect a combination of technological advances enabling increased detection, but also changes in environmental factors, including population exposure to ionising radiation from fallout, diagnostic tests and treatment for benign and malignant conditions. Studies of the atomic bomb survivors and populations treated with radiotherapy have established radiation as a risk factor for thyroid cancer, particularly from early life exposure. About 0.62 mSv (20%) of the global annual per caput effective radiation dose comes from diagnostic medical and dental radiation for the period of 1997-2007, increased from 0.4 mSv for the years 1991-1996. This international trend of increasing population exposure to medical diagnostic sources of radiation, attributed in large part to the growing use of computed tomography scans, but also interventional radiology procedures, has raised concerns about exposure to radiosensitive organs such as the thyroid. Worldwide, medical and dental X-rays constitute the most common type of diagnostic medical exposures, but their contribution to the cumulative effective dose is relatively low, whereas computed tomography scans account for 7.9% of diagnostic radiology examinations but 47% of the collective effective dose from diagnostic radiation procedures in parts of the world. Although the radiation exposure from computed tomography scans is substantially lower than that from radiotherapy, multiple computed tomography scans could result in non-trivial cumulative doses to the thyroid. Studies are currently underway to assess the incidence of cancer in large cohorts of children who received computed tomography scans. National and international efforts have been developed to raise awareness and to standardise procedures for use of computed tomography and interventional radiology procedures in paediatric and general populations. PMID:21296564

Schonfeld, S J; Lee, C; Berrington de González, A

2011-05-01

108

PROBABILISTIC MODELING FOR ADVANCED HUMAN EXPOSURE ASSESSMENT  

EPA Science Inventory

Human exposures to environmental pollutants widely vary depending on the emission patterns that result in microenvironmental pollutant concentrations, as well as behavioral factors that determine the extent of an individual's contact with these pollutants. Probabilistic human exp...

109

Low-dose radiation exposure and carcinogenesis.  

PubMed

Absorption of energy from ionizing radiation by the genetic material in the cell leads to damage to DNA, which in turn leads to cell death, chromosome aberrations and gene mutations. While early or deterministic effects result from organ and tissue damage caused by cell killing, latter two are considered to be involved in the initial events that lead to the development of cancer. Epidemiological studies have demonstrated the dose-response relationships for cancer induction and quantitative evaluations of cancer risk following exposure to moderate to high doses of low-linear energy transfer radiation. A linear, no-threshold model has been applied to assessment of the risks resulting from exposure to moderate and high doses of ionizing radiation; however, a statistically significant increase has hardly been described for radiation doses below 100 mSv. This review summarizes our current knowledge of the physical and biological features of low-dose radiation and discusses the possibilities of induction of cancer by low-dose radiation. PMID:22641644

Suzuki, Keiji; Yamashita, Shunichi

2012-07-01

110

An approach to simulate and visualize intraoperative scattered radiation exposure to improve radiation protection training.  

PubMed

Intraoperative radiography based on mobile image intensifier systems (C-arms) is widely used during the treatment of trauma and emergency patients. These devices produce scattered radiation, potential hazardous for surgeon and operation room personal (ORP). The propagation and intensity of scattered radiation is not intuitive, is not perceivable by human senses and depends on many variables. At courses on radiation protection the knowledge of the behavior of scattered radiation and the modus operandi to minimize the radiation exposure should be taught to ORP and surgeons. Currently this can only be done theoretically using fixed pictures and precalculated videos. This paper presents an approach to interactively simulate and visualize scattered radiation with a computer based training system for mobile image intensifier systems. The simulation depicts radiation propagation and intensity for arbitrary C-arm adjustments and different irradiated materials. This teaching component focuses on improving the current radiation protection training with interactive visual and practical aspects. PMID:20841762

Wagner, Markus; Duwenkamp, Christopher; Ludwig, Wolfram; Dresing, Klaus; Bott, Oliver Johannes

2010-01-01

111

Limiting radiation exposure during percutaneous nephrolithotomy.  

PubMed

Background An increase in the prevalence of urological stone disease and the refinement of endo-urological techniques has seen a concomitant rise in the use of fluoroscopy during surgery. As such there has been increasing concern in regards to the intra-operative radiation exposure to both clinicians and patients . Objective To audit contemporary data on radiation exposure during PCNL, in comparison with published series, and demonstrate that relatively low levels are achievable with clinical vigilance and attention to technique Design, Setting, and Participants Retrospective analysis of all PCNL's undertaken between July 2005 and December 2011. Outcome Measurements and Statistical Analysis Primary outcome measure was fluoroscopy times and associated radiation exposure, measured as dose area product (DAP). No statistical analysis was undertaken. Results and Limitations Between July 2005 and October 2011, 376 PCNLs were performed. Data were available on 348 patients including 16 paediatric cases. Mean DAP and ST over the whole study period were 452cGycm2 and 96s respectively. On a year by year basis the ST and DAP reduced from 917 to 375 and from 180 to 65 respectively. We acknowledge the limitation of this being a retrospective case series. Conclusions This study represents the largest series to date on radiation exposure during PCNL, and compares favourably with other published series, including those purporting novel techniques. Subtle changes in surgical technique and experience over time, can lead to low screening times, and can be potentially achieved by all operators performing PCNL within a high through-put centre. Patient Summary It is now recognised that surgical outcome in stone surgery is related to case load. The radiation dose the patient receives during a PCNL is increasingly recognised to be an important factor and can be reduced by careful technique and experience. PMID:25423185

Hanna, Luke; Walmsley, Byron H; Rogers, Anne; Devenish, Sue; Keoghane, Stephen R

2014-11-25

112

Radically Reducing Radiation Exposure during Routine Medical Imaging  

Cancer.gov

Exposure to radiation from medical imaging in the United States has increased dramatically. NCI and several partner organizations sponsored a 2011 summit to promote efforts to reduce radiation exposure from medical imaging.

113

Radiation exposure of fertile women in medical research studies  

SciTech Connect

Fertile women may be exposed to ionizing radiation as human subjects in medical research studies. If the woman is pregnant, such exposures may result in risk to an embryo/fetus. Fertile women may be screened for pregnancy before exposure to ionizing radiation by interview, general examination, or pregnancy test. Use of the sensitive serum pregnancy test has become common because it offers concrete evidence that the woman is not pregnant (more specifically, that an embryo is not implanted). Evidence suggests that risk to the embryo from radiation exposure before organogenesis is extremely low or nonexistent. Further, demonstrated effects on organogenesis are rare or inconclusive at fetal doses below 50 mSv (5 rem). Therefore, there may be some level of radiation exposure below which risk to the fetus may be considered essentially zero, and a serum pregnancy test is unnecessary. This paper reviews the fetal risks and suggests that consideration be given to establishing a limit to the fetus of 0.5 mSv (50 mrem), below which pregnancy screening need not include the use of a serum pregnancy test.

Vetter, R.J.

1988-08-01

114

Occupation- and exposure-related studies on human sperm.  

PubMed

Many kinds of exposures and chemicals have been shown to affect human sperm quantity and quality. This review focuses first on the best known occupational testicular toxin, dibromochloropropane. Prolonged heat is clearly detrimental to spermatogenesis. Studies on occupational heat, radiation, and chemical exposures and their effects on sperm are reviewed. The evaluation of human sperm studies is hampered by inconsistencies in biological analytical methods, in control for confounders, and in weaknesses of study design. Still, there is reason to suggest that human semen parameters can serve as valuable indicators of toxic and, in future, even genotoxic effects of occupational and environmental factors. PMID:8520954

Lähdetie, J

1995-08-01

115

47 CFR 2.1091 - Radiofrequency radiation exposure evaluation: mobile devices.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Radiofrequency radiation exposure evaluation: mobile devices...Authorization Procedures Radiofrequency Radiation Exposure § 2.1091 Radiofrequency radiation exposure evaluation: mobile...

2013-10-01

116

47 CFR 2.1091 - Radiofrequency radiation exposure evaluation: mobile devices.  

... 2014-10-01 false Radiofrequency radiation exposure evaluation: mobile devices...Authorization Procedures Radiofrequency Radiation Exposure § 2.1091 Radiofrequency radiation exposure evaluation: mobile...

2014-10-01

117

48 CFR 952.223-75 - Preservation of individual occupational radiation exposure records.  

Code of Federal Regulations, 2010 CFR

...Preservation of individual occupational radiation exposure records...Preservation of Individual Occupational Radiation Exposure Records...1984) Individual occupational radiation exposure records generated in the performance of work under...

2010-10-01

118

Changes in Liver Metabolic Gene Expression from Radiation Exposure  

NASA Technical Reports Server (NTRS)

Radiation exposure is one of the unique physiological challenges of human spaceflight that is not encountered on earth. While radiation exposure is known to impart physiological stresses and alter normal function, it is unclear how it specifically affects drug metabolism. A major concern is that the actions of medications used in spaceflight may deviate from the expectations formed from terrestrial use. This concern was investigated at the molecular level by analyzing how gamma radiation exposure affected gene expression in the livers of mice. Three different doses of radiation were administered and after various intervals of recovery time, gene expression was measured with RT-qPCR screening arrays for drug metabolism and DNA repair. After examining the results of 192 genes total from each of 72 mice, 65 genes were found to be significantly affected by at least one of the doses of radiation. In general, the genes affected are involved in the metabolism of drugs with lipid or steroid hormone-like structures, as well as the maintenance of redox homeostasis and repair of DNA damage.

Peters, C. P.; Wotring, Virginia E.

2011-01-01

119

Intrauterine radiation exposures and mental retardation  

Microsoft Academic Search

Small head size and mental retardation have been known as effects of intrauterine exposure to ionizing radiation since the 1920s. In the 1950s, studies of Japanese atomic-bomb survivors revealed that at 4-17 wk of gestation, the greater the dose, the smaller the brain (and head size), and that beginning at 0.5 Gy (50 rad) in Hiroshima, mental retardation increased in

R. W. Miller

1988-01-01

120

Thyroid tumors associated with radiation exposure.  

PubMed Central

Epidemiologic studies of medically and environmentally exposed populations have been central to establishing ionizing radiation as a cause of malignant and benign thyroid tumors. Issues currently under investigation concern low dose effects, age sensitivity, the relative effectiveness of X-rays and iodine-131 in inducing thyroid cancer, and other risk factors. Excess thyroid tumors continue to appear in irradiated populations under study more than three decades after exposure. PMID:6431485

Silverman, C

1984-01-01

121

Radiation exposure monitoring in civil aircraft  

NASA Astrophysics Data System (ADS)

Based on the 1990 Recommendation of the ICRP (ICRP Publication 60, Pergamon Press, Oxford, 1991) a European Directive [Official J. Eur. Communities 19 (1996) L159, 1-114] commits the European Union (EU) member states to revise their national radiation protection laws by the year 2000 such that the exposure of aircrews to the increased cosmic radiation prevailing at aviation flight altitudes will be treated as occupational risks. A consequence will be that employers must assess the aircrew exposure. The ACREM (Air Crew Radiation Exposure Monitoring) research project intends to investigate practically methods for aircraft dose equivalent determination. The in-flight measurements were carried out on cargo aircraft. Field calibrations were performed using Tissue-Equivalent Proportional Counters (TEPC) as the reference instrument. Various monitors were used to investigate the spatial doserate distribution. The measured data were collated according to the different altitudes and geomagnetic latitudes. The results obtained from various in-flight measurements are reported and a concept for a future routine dose assessment for aircrew is proposed.

Schrewe, Ulrich J.

1999-02-01

122

Attenuation of G{sub 2} cell cycle checkpoint control in human tumor cells is associated with increased frequencies of unrejoined chromosome breaks but not increased cytotoxicity following radiation exposure  

SciTech Connect

The contribution of G{sub 2} cell cycle checkpoint control to ionizing radiation responses was examined in ten human tumor cell lines. Most of the delay in cell cycle progression seen in the first cell cycle following radiation exposure was due to blocks in G{sub 2} and there were large cell line-to-cell line variations in the length of the G{sub 2} block. Longer delays were seen in cell lines that had mutations in p53. There was a highly significant inverse correlation between the length of G{sub 2} delay and the frequency of unrejoined chromosome breaks seen as chromosome terminal deletions in mitosis, and observation that supports the hypothesis that the signal for G{sub 2} delay in mammalian cells is an unrejoined chromosome break. There were also an inverse correlation between the length of G{sub 2} delay and the level of chromosome aneuploidy in each cell line, suggesting that the G{sub 2} and mitotic spindel checkpoints may be linked to each other. Attenuation in G{sub 2} checkpoint control was not associated with alterations in either the frequency of induced chromosome rearrangements or cell survival following radiation exposure suggesting that chromosome rearrangements, the major radiation-induced lethal lesion in tumor cells, form before cells enters G{sub 2}. Thus, agents that act solely to override G{sub 2} arrest should produce little radiosensitization in human tumor cells.

Schwartz, J.L.; Cowan, J.; Grdina, D.J. [and others

1997-08-01

123

Mars Radiation Risk Assessment and Shielding Design for Long-term Exposure to Ionizing Space Radiation  

NASA Technical Reports Server (NTRS)

NASA is now focused on the agency's vision for space exploration encompassing a broad range of human and robotic missions including missions to Moon, Mars and beyond. As a result, there is a focus on long duration space missions. NASA is committed to the safety of the missions and the crew, and there is an overwhelming emphasis on the reliability issues for space missions and the habitat. The cost-effective design of the spacecraft demands a very stringent requirement on the optimization process. Exposure from the hazards of severe space radiation in deep space and/or long duration missions is a critical design constraint and a potential 'show stopper'. Thus, protection from the hazards of severe space radiation is of paramount importance to the agency's vision. It is envisioned to have long duration human presence on the Moon for deep space exploration. The exposures from ionizing radiation - galactic cosmic radiation and solar particle events - and optimized shield design for a swing-by and a long duration Mars mission have been investigated. It is found that the technology of today is inadequate for safe human missions to Mars, and revolutionary technologies need to be developed for long duration and/or deep space missions. The study will provide a guideline for radiation exposure and protection for long duration missions and career astronauts and their safety.

Tripathi, Ram K.; Nealy, John E.

2007-01-01

124

Proteomic Analysis of Low Dose Arsenic and Ionizing Radiation Exposure on Keratinocytes  

E-print Network

and ionizing radiation occur environmentally at low levels. While the human health effects of arsenic level arsenic and low dose ionizing radiation are both environmental toxicants. While data exist whichProteomic Analysis of Low Dose Arsenic and Ionizing Radiation Exposure on Keratinocytes Susanne R

Rocke, David M.

125

MODELING ACUTE EXPOSURE TO SOLAR RADIATION  

EPA Science Inventory

One of the major technical challenges in calculating solar flux on the human form has been the complexity of the surface geometry (i.e., the surface normal vis a vis the incident radiation). The American Cancer Society reports that over 80% of skin cancers occur on the face, he...

126

Depression of p53-independent Akt survival signals in human oral cancer cells bearing mutated p53 gene after exposure to high-LET radiation  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer High-LET radiation induces efficiently apoptosis regardless of p53 gene status. Black-Right-Pointing-Pointer We examined whether high-LET radiation depresses the Akt-survival signals. Black-Right-Pointing-Pointer High-LET radiation depresses of survival signals even in the mp53 cancer cells. Black-Right-Pointing-Pointer High-LET radiation activates Caspase-9 through depression of survival signals. Black-Right-Pointing-Pointer High-LET radiation suppresses cell growth through depression of survival signals. -- Abstract: Although mutations and deletions in the p53 tumor suppressor gene lead to resistance to low linear energy transfer (LET) radiation, high-LET radiation efficiently induces cell lethality and apoptosis regardless of the p53 gene status in cancer cells. Recently, it has been suggested that the induction of p53-independent apoptosis takes place through the activation of Caspase-9 which results in the cleavage of Caspase-3 and poly (ADP-ribose) polymerase (PARP). This study was designed to examine if high-LET radiation depresses serine/threonine protein kinase B (PKB, also known as Akt) and Akt-related proteins. Human gingival cancer cells (Ca9-22 cells) harboring a mutated p53 (mp53) gene were irradiated with 2 Gy of X-rays or Fe-ion beams. The cellular contents of Akt-related proteins participating in cell survival signaling were analyzed with Western Blotting 1, 2, 3 and 6 h after irradiation. Cell cycle distributions after irradiation were assayed with flow cytometric analysis. Akt-related protein levels decreased when cells were irradiated with high-LET radiation. High-LET radiation increased G{sub 2}/M phase arrests and suppressed the progression of the cell cycle much more efficiently when compared to low-LET radiation. These results suggest that high-LET radiation enhances apoptosis through the activation of Caspase-3 and Caspase-9, and suppresses cell growth by suppressing Akt-related signaling, even in mp53 bearing cancer cells.

Nakagawa, Yosuke [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)] [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Takahashi, Akihisa [Advanced Scientific Research Leader Development Unit, Gunma University, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan)] [Advanced Scientific Research Leader Development Unit, Gunma University, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511 (Japan); Kajihara, Atsuhisa; Yamakawa, Nobuhiro; Imai, Yuichiro [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)] [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Ota, Ichiro; Okamoto, Noritomo [Department of Otorhinolaryngology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)] [Department of Otorhinolaryngology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Mori, Eiichiro [Department of Radiation Oncology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)] [Department of Radiation Oncology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Noda, Taichi [Department of Dermatology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)] [Department of Dermatology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Furusawa, Yoshiya [Heavy-ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan)] [Heavy-ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kirita, Tadaaki [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)] [Department of Oral and Maxillofacial Surgery, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Ohnishi, Takeo, E-mail: tohnishi@naramed-u.ac.jp [Department of Radiation Oncology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)] [Department of Radiation Oncology, School of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan)

2012-07-13

127

Individual variation in p53 and Cip1 expression profiles in normal human fibroblast strains following exposure to high-let radiation  

SciTech Connect

Exposure to {alpha}-particles emitted by radon progeny appears to be the second-leading cause of lung cancer mortality. However, individual susceptibility to the carcinogenic effects of {alpha}-particles remains poorly characterized. Variation in susceptibility to cancer produced by certian classes of DNA-damaging chemicals is suspected to involve differences in metabolic activation and detoxication. Susceptibility to {alpha}-particle-induced cancer may involve variations in capacity or opportunity to repair DNA damage. Subtle variations in DNA repair capacity would more likely explain radon-related lung cancer susceptibility. The p53 tumor suppressor protein accumulates as a cellular response to DNA damage from ionizing radiation and regulates arrest in the G{sub 1} portion of the cell cycle. Arrest in G{sub 1} portion of the cell cycle. While upstream regulation of p53 protein stability is poorly understood, variations in the ability to accumulate p53 following DNA damage represent potential variations in lung cancer susceptibility related to radon progeny. Further, transcription of the cell-cycle regulatory gene Cip1 is regulated by p53 and increases following ionizing radiation. Therefore, variations in the expression of Cip1 following {alpha}-particle exposure may also be a susceptibility factor in radon-related lung cancers. The purpose of the present investigation was to measure p53 and Cip1 protein induction following {alpha}-particle exposure of fibroblast lines from nine individuals to determine if there were significant variations. The expression of Cip1 protein indicates the differences in response are biologically relevant.

Carpenter, T.R.; Johnson, N.F.; Gilliland, F.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

1995-12-01

128

Controlled human exposures to diesel exhaust  

EPA Science Inventory

Diesel exhaust (DE) is a complex mixture of gaseous and particulate compounds resulting from an incomplete combustion of diesel fuel. Controlled human exposures to DE and diesel exhaust particles (DEP) have contributed to understanding health effects. Such exposure studies of h...

129

HUMAN EXPOSURE DATABASE SUPPORT AND MANAGEMENT  

EPA Science Inventory

Researchers in the National Exposure Research Laboratory (NERL) have performed a number of large human exposure measurement studies during the past decade. It is the goal of the NERL to make the data available to other researchers for analysis in order to further the scientific ...

130

Human occupational and nonoccupational exposure to fibers.  

PubMed Central

Human exposure to fibers in occupational and nonoccupational environments has been a health concern for nearly a century. In this review, selected results from the literature are presented to highlight the availability, limitations, and interpretive difficulties associated with the past and current human fiber exposure data sets. In the traditionally defined asbestos fibers, large amounts of the data available suffer from the diversity of sample collection and analysis methods. Two simple generalizations suggest that occupational exposures are several orders of magnitude higher than that of environmental exposures; and currently extant data and the current routine measurement practices present significant difficulties in the consistent interpretation of the data with respect to health effects. The data on the human exposures to man-made vitreous fibers are much more complete than the data on asbestos exposure, while exposure data on other man-made fibrous materials are lacking. The human exposure data to many minerals which, at times, exist in fibrous habit, are very scanty, and in view of the biological activity of some of these fibers, this lack may be of significant concern. PMID:2272324

Esmen, N A; Erdal, S

1990-01-01

131

PARTNERING TO IMPROVE HUMAN EXPOSURE METHODS  

EPA Science Inventory

Methods development research is an application-driven scientific area that addresses programmatic needs. The goals are to reduce measurement uncertainties, address data gaps, and improve existing analytical procedures for estimating human exposures. Partnerships have been develop...

132

Intrauterine radiation exposures and mental retardation  

SciTech Connect

Small head size and mental retardation have been known as effects of intrauterine exposure to ionizing radiation since the 1920s. In the 1950s, studies of Japanese atomic-bomb survivors revealed that at 4-17 wk of gestation, the greater the dose, the smaller the brain (and head size), and that beginning at 0.5 Gy (50 rad) in Hiroshima, mental retardation increased in frequency with increasing dose. No other excess of birth defects was observed. Otake and Schull (1984) pointed out that the period of susceptibility to mental retardation coincided with that for proliferation and migration of neuronal elements from near the cerebral ventricles to the cortex. Mental retardation could be the result of interference with this process. Their analysis indicated that exposures at 8-15 wk to 0.01-0.02 Gy (1-2 rad) doubled the frequency of severe mental retardation. This estimate was based on small numbers of mentally retarded atomic-bomb survivors. Although nuclear accidents have occurred recently, new cases will hopefully be too rare to provide further information about the risk of mental retardation. It may be possible, however, to learn about lesser impairment. New psychometric tests may be helpful in detecting subtle deficits in intelligence or neurodevelopmental function. One such test is PEERAMID, which is being used in schools to identify learning disabilities due, for example, to deficits in attention, short- or long-term memory, or in sequencing information. This and other tests could be applied in evaluating survivors of intrauterine exposure to various doses of ionizing radiation. The results could change our understanding of the safety of low-dose exposures.

Miller, R.W.

1988-08-01

133

Patient radiation exposure during different kyphoplasty techniques.  

PubMed

The scope of this study was to quantify patient radiation exposure during two different techniques of kyphoplasty (KP), which differ by a cement delivery method, in order to assess whether or not one of the two used methods can reduce the patient dose. Twenty patients were examined for this investigation. One X-ray fluoroscopy unit was used for localization, navigation and monitoring of cement delivery. The patient biometric data, the setting of the fluoroscope, the exposure time and the kerma-area product (KAP) were monitored in all the procedures for anteroposterior (AP) and lateral (LL) fluoroscopic projections in order to assess the range of radiation doses imparted to the patient. Theoretical entrance skin dose (ESD) and effective dose (E) were calculated from intraoperatively measured KAP. An average ET per procedure was 1.5±0.5 min for the manual injection technique (study A) and 1.4±0.4 min for the distance delivery technique (study B) in the AP plane, while 3.2±0.7 and 5.1±0.6 min in the lateral plane, respectively. ESD was estimated as an average of 0.10±0.06 Gy for study A and 0.13±0.13 Gy for study B in the AP or/and 0.59±0.46 and 1.05±0.36 Gy in the lateral view, respectively. The cumulative mean E was 1.9±1.0 mSv procedure(-1) for study A and 3.6±0.9 mSv procedure(-1) for study B. Patient radiation exposure and associated effective dose from KP may be considerable. The technique of distance cement delivery appears to be slower than the manual injection technique and it requires a more protracted fluoroscopic control in the lateral projection, so that this system entails a higher amount of dose to the patient. PMID:24030142

Panizza, Denis; Barbieri, Massimo; Parisoli, Francesco; Moro, Luca

2014-01-01

134

DOE 2008 Occupational Radiation Exposure October 2009  

SciTech Connect

A major priority of the U.S. Department of Energy (DOE) is to ensure the health, safety, and security of DOE employees, contractors, and subcontractors. The Office of Health, Safety and Security (HSS) provides the corporate-level leadership and strategic vision necessary to better coordinate and integrate health, safety, environment, security, enforcement, and independent oversight programs. One function that supports this mission is the DOE Corporate Operating Experience Program that provides collection, analysis, and dissemination of performance indicators, such as occupational radiation exposure information. This analysis supports corporate decision-making and synthesizes operational information to support continuous environment, safety, and health improvement across the DOE complex.

U.S. Department of Energy, Office of Health, Safety and Security

2009-10-01

135

Exposure to radiofrequency radiation (900 MHz, GSM signal) does not affect micronucleus frequency and cell proliferation in human peripheral blood lymphocytes: an interlaboratory study.  

PubMed

The objective of this study was to investigate whether 24 h exposure to radiofrequency electromagnetic fields similar to those emitted by mobile phones induces genotoxic effects and/or effects on cell cycle kinetics in cultured human peripheral blood lymphocytes. The effect of 900 MHz exposure (GSM signal) was evaluated at four specific absorption rates (SARs, 0, 1, 5 and 10 W/kg peak values). The exposures were carried out in wire patch cells under strictly controlled conditions of both temperature and dosimetry, and the induction of genotoxic effects was evaluated in lymphocyte cultures from 10 healthy donors by applying the cytokinesis-block micronucleus assay. Positive controls were provided by using mitomycin C. Two research groups were involved in the study, one at ENEA, Rome, and the other at CNR-IREA, Naples. Each laboratory tested five donors, and the resulting slides were scored by both laboratories. Following this experimental scheme, it was also possible to compare the results obtained by cross-scoring of slides. The results obtained provided no evidence for the existence of genotoxic or cytotoxic effects in the range of SARs investigated. These findings were confirmed in the two groups of five donors examined in the two laboratories and when the same slides were scored by two operators. PMID:16802865

Scarfì, Maria Rosaria; Fresegna, Anna Maria; Villani, Paola; Pinto, Rosanna; Marino, Carmela; Sarti, Maurizio; Altavista, Pierluigi; Sannino, Anna; Lovisolo, Giorgio A

2006-06-01

136

Measurement methods for human exposure analysis.  

PubMed Central

The general methods used to complete measurements of human exposures are identified and illustrations are provided for the cases of indirect and direct methods used for exposure analysis. The application of the techniques for external measurements of exposure, microenvironmental and personal monitors, are placed in the context of the need to test hypotheses concerning the biological effects of concern. The linkage of external measurements to measurements made in biological fluids is explored for a suite of contaminants. This information is placed in the context of the scientific framework used to conduct exposure assessment. Examples are taken from research on volatile organics and for a large scale problem: hazardous waste sites. PMID:7635110

Lioy, P J

1995-01-01

137

Cancer Risks After Radiation Exposure in Middle Age  

PubMed Central

Background Epidemiological data show that radiation exposure during childhood is associated with larger cancer risks compared with exposure at older ages. For exposures in adulthood, however, the relative risks of radiation-induced cancer in Japanese atomic bomb survivors generally do not decrease monotonically with increasing age of adult exposure. These observations are inconsistent with most standard models of radiation-induced cancer, which predict that relative risks decrease monotonically with increasing age at exposure, at all ages. Methods We analyzed observed cancer risk patterns as a function of age at exposure in Japanese atomic bomb survivors by using a biologically based quantitative model of radiation carcinogenesis that incorporates both radiation induction of premalignant cells (initiation) and radiation-induced promotion of premalignant damage. This approach emphasizes the kinetics of radiation-induced initiation and promotion, and tracks the yields of premalignant cells before, during, shortly after, and long after radiation exposure. Results Radiation risks after exposure in younger individuals are dominated by initiation processes, whereas radiation risks after exposure at later ages are more influenced by promotion of preexisting premalignant cells. Thus, the cancer site–dependent balance between initiation and promotion determines the dependence of cancer risk on age at radiation exposure. For example, in terms of radiation induction of premalignant cells, a quantitative measure of the relative contribution of initiation vs promotion is 10-fold larger for breast cancer than for lung cancer. Reflecting this difference, radiation-induced breast cancer risks decrease with age at exposure at all ages, whereas radiation-induced lung cancer risks do not. Conclusion For radiation exposure in middle age, most radiation-induced cancer risks do not, as often assumed, decrease with increasing age at exposure. This observation suggests that promotional processes in radiation carcinogenesis become increasingly important as the age at exposure increases. Radiation-induced cancer risks after exposure in middle age may be up to twice as high as previously estimated, which could have implications for occupational exposure and radiological imaging. PMID:20975037

Shuryak, Igor; Sachs, Rainer K.

2010-01-01

138

Assessment of human exposure to gaseous pollutants  

Microsoft Academic Search

A mathematical model to aid in assessment of human environmental exposure to volatile organic substances is presented. The model simulates the convective and diffusive transport of gas from the ambient environment into the human body by way of the respiratory and circulatory systems. Data required include easily obtained physical and chemical properties of substances as well as several estimated or

Leland B. Baskin; James W. Falco

1989-01-01

139

Monitoring human exposure to pesticides using immunoassay  

E-print Network

at the estimation of internal dose based on the fate of the compound in human body. Biological monitoring approachesMonitoring human exposure to pesticides using immunoassay Marja E. Koivunen1,2 , Shirley J. Gee1 of automated immunoanalyzers, immunosensors or microchips with flow-through systems. Biological monitoring

Hammock, Bruce D.

140

What Have "Omics" Taught Us about the Health Risks Associated with Exposure to Low Doses of Ionizing Radiation  

SciTech Connect

There is a plethora of data available on the DNA damages associated with exposures to ionizing radiation and the subsequent cellular responses. Indeed, much of radiation research has focused on these initial insults and induced responses, particularly DNA repair, cell signaling pathways, cell cycle checkpoint control, mutation induction, chromosomal rearrangements, transformation and apoptosis etc. While many of these endpoints correlate with exposure dose, few, if any, provide substantive information on human health risk(s) associated with radiation exposure. Here the contribution of recent advances in high throughput ‘omics technologies are evaluated to examine what they have taught us about health risk(s) to humans associated with exposure to ionizing radiation.

Morgan, William F.; Sowa, Marianne B.

2011-04-27

141

SCALING THE PHYSIOLOGICAL EFFECTS OF EXPOSURE TO RADIOFREQUENCY ELECTROMAGNETIC RADIATION: CONSEQUENCES OF BODY SIZE  

EPA Science Inventory

The authors have demonstrated that a comparative analysis of the physiological effects of exposure of laboratory mammals to radiofrequency electromagnetic radiation (RFR) may be useful in predicting exposure thresholds for humans if the effect is assumed to be due only to heating...

142

THYROID CANCER RISK FROM EXPOSURE TO IONIZING RADIATION: A CASE STUDY IN THE COMPARATIVE POTENCY MODEL  

EPA Science Inventory

Considerable controversy exists about the relative risk of thyroid cancer following exposure to external radiation compared to the risk after exposure to internally deposited 131I. he human epidemiological data are equivocal, and studies are not directly comparable owing to diffe...

143

Radiation Exposure in X-Ray and CT Examinations  

MedlinePLUS

... the largest source of background radiation comes from radon gas in our homes (about 2 mSv per ... Like other sources of background radiation, exposure to radon varies widely from one part of the country ...

144

Real and Perceived Risks of Medical Radiation Exposure  

PubMed Central

There is almost no subject that elicits greater concern and less objective understanding than that of exposure of patients to radiation accompanying diagnostic radiologic procedures. One or more of the health effects (cancer, developmental abnormalties and genetic changes) attributed to low-level exposure to radiation are frequently misinterpreted as likely consequences rather than statistical risks following radiation exposure. Even less well understood is the small magnitude of the risks accompanying radiation exposure compared with those related to activities encountered during the daily routine. For this reason, the perception of risk associated with exposure to low-level radiation is inconsistent with the reality of the risk as estimated by even the most conservative models of radiation injury. PMID:6858126

Hendee, William R.

1983-01-01

145

Human risk associated with palytoxin exposure.  

PubMed

Palytoxin (PTX) was first isolated from the zoanthid Palythoa toxica. Evaluation of PTX toxicity using various animal models determined that PTX was extremely potent through intravenous, intraperitoneal, and intratracheal exposure. PTX was less potent by direct intragastric exposure. PTX also caused significant, non-lethal effects through dermal and ocular exposure. PTX and PTX-like compounds have now been found in additional zoanthid species, red alga, a sea anemone, and several dinoflagellates. PTXs are found throughout certain reef associated food webs, including in fish and crabs responsible for human illness and death. Many of the organisms found to contain PTXs in the environment are also sold in the home aquarium trade, and recent evidence suggests poisonings have occurred through exposure to these organisms. Due to co-occurrence with other seafood toxins, such as ciguatoxins, saxitoxins, and tetrodotoxin, it has been difficult to assess the true risk of PTX poisoning through seafood consumption in humans, but limited cases have been well documented, some involving human fatalities. Recent evidence also suggests that humans are negatively impacted through PTX exposure by inhalation and dermal routes. Continued research into the distribution and occurrence of PTX and PTX-like compounds both in seafood and marine organisms sold in the aquarium trade appears warranted. PMID:19505494

Deeds, Jonathan R; Schwartz, Michael D

2010-08-15

146

Medical radiation exposure and genetic risks  

SciTech Connect

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

Baker, D.G.

1980-09-01

147

Female germ cell loss from radiation and chemical exposures.  

PubMed

Female germ cells in some mammals are extremely sensitive to killing by ionizing radiation, especially during development. Primordial oocytes in juvenile mice have an LD50 of only 6-7 rad, and the germ cell pool in squirrel monkeys is destroyed by prenatal exposure of 0.7 rad/day. Sensitivity varies greatly with species and germ cell stage. Unusually high sensitivity has not been found in macaques and may not occur in man, but this has not been established for all developmental stages. The exquisite oocyte radiosensitivity in mice apparently reflects vulnerability of the plasma membrane, not DNA, which may have implications for estimating human genetic risks. Germ cells can be killed also by chemicals. Such oocyte loss, with similarities to radiation effects, is under increasing study, including chemotherapy observations in women. More than 75 compounds have been tested in mice, with in vivo toxicity quantified by oocyte loss; certain chemicals apparently act on the membrane. PMID:6340477

Dobson, R L; Felton, J S

1983-01-01

148

Space Radiation and Risks to Human Health  

NASA Technical Reports Server (NTRS)

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

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

2014-01-01

149

Human exposure to large solar particle events in space  

NASA Technical Reports Server (NTRS)

Whenever energetic solar protons produced by solar particle events traverse bulk matter, they undergo various nuclear and atomic collision processes which significantly alter the physical characteristics and biologically important properties of their transported radiation fields. These physical interactions and their effect on the resulting radiation field within matter are described within the context of a recently developed deterministic, coupled neutron-proton space radiation transport computer code (BRYNTRN). Using this computer code, estimates of human exposure in interplanetary space, behind nominal (2 g/sq cm) and storm shelter (20 g/sq cm) thicknesses of aluminum shielding, are made for the large solar proton event of August 1972. Included in these calculations are estimates of cumulative exposures to the skin, ocular lens, and bone marrow as a function of time during the event. Risk assessment in terms of absorbed dose and dose equivalent is discussed for these organs. Also presented are estimates of organ exposures for hypothetical, worst-case flare scenarios. The rate of dose equivalent accumulation places this situation in an interesting region of dose rate between the very low values of usual concern in terrestrial radiation environments and the high-dose-rate values prevalent in radiation therapy.

Townsend, L. W.; Wilson, J. W.; Shinn, J. L.; Curtis, S. B.

1992-01-01

150

Maintenance hemodialysis patients have high cumulative radiation exposure  

Microsoft Academic Search

Hemodialysis is associated with an increased risk of neoplasms which may result, at least in part, from exposure to ionizing radiation associated with frequent radiographic procedures. In order to estimate the average radiation exposure of those on hemodialysis, we conducted a retrospective study of 100 patients in a university-based dialysis unit followed for a median of 3.4 years. The number

Sinead M Kinsella; Joe P Coyle; Eva B Long; Sebastian R McWilliams; Michael M Maher; Michael R Clarkson; Joseph A Eustace

2010-01-01

151

Methylmercury exposure and health effects in humans  

Microsoft Academic Search

Abstract. Methylmercury (MeHg) is a worldwide contaminant found in seafood and freshwater fish, which constitute the dominant,source of human,exposure,to this substance. The developing,human,brain is particularly susceptible to injury caused by MeHg, which easily passes the placental barrier. Epidemiological studies in fishing populations have found subtle though,lasting adverse effects on brain functions of children who,were exposed,prenatally to MeHg from seafood diets.

Anna L. Choi; Philippe Grandjean

2008-01-01

152

Radiation exposure of nurses in a coronary care unit  

SciTech Connect

In response to increasing awareness of radiation as a possible occupational hazard, nursing personnel staffing a hospital CCU were monitored over a 3-year period to determine occupational exposure. Portable x-ray machines, fluoroscopic units, and patients injected with radiopharmaceuticals were all potential radiation sources on such a unit. Whole-body TLD badges, exchanged monthly, indicated no cumulative exposures over 80 mR during the entire study period. The minimal exposures reported do not justify regular use of dosimeters. Adherence to standard protective measures precludes most exposure to machine-produced radiation. Close, prolonged contact with a patient after an RVG study that utilizes /sup 99m/Tc may account for some exposure. The data indicate that radiation is not a significant occupational hazard for CCU nurses at this hospital; similar minimal exposures would be expected of other nonoccupationally exposed nursing personnel in like environments.

Jankowski, C.B.

1984-01-01

153

[Registration and monitoring of radiation exposure from radiological imaging].  

PubMed

Strategies for reducing radiation exposure are an important part of optimizing medical imaging and therefore a relevant quality factor in radiology. Regarding the medical radiation exposure, computed tomography has a special relevance. The use of the integrating the healthcare enterprise (IHE) radiation exposure monitoring (REM) profile is the upcoming standard for organizing and collecting exposure data in radiology. Currently most installed base devices do not support this profile generating the required digital imaging and communication in medicine (DICOM) dose structured reporting (SR). For this reason different solutions had been developed to register dose exposure measurements without having the dose SR object.Registration and analysis of dose-related parameters is required for constantly optimizing examination protocols, especially computed tomography (CT) examinations based on the latest research results in order to minimize the individual radiation dose exposure from medical imaging according to the principle as low as reasonably achievable (ALARA). PMID:23519445

Jungmann, F; Pinto dos Santos, D; Hempel, J; Düber, C; Mildenberger, P

2013-06-01

154

DNA Damage Responses following Exposure to Modulated Radiation Fields  

PubMed Central

During the delivery of advanced radiotherapy treatment techniques modulated beams are utilised to increase dose conformity across the target volume. Recent investigations have highlighted differential cellular responses to modulated radiation fields particularly in areas outside the primary treatment field that cannot be accounted for by scattered dose alone. In the present study, we determined the DNA damage response within the normal human fibroblast AG0-1522B and the prostate cancer cell line DU-145 utilising the DNA damage assay. Cells plated in slide flasks were exposed to 1 Gy uniform or modulated radiation fields. Modulated fields were delivered by shielding 25%, 50% or 75% of the flask during irradiation. The average number of 53BP1 or ?H2AX foci was measured in 2 mm intervals across the slide area. Following 30 minutes after modulated radiation field exposure an increase in the average number of foci out-of-field was observed when compared to non-irradiated controls. In-field, a non-uniform response was observed with a significant decrease in the average number of foci compared to uniformly irradiated cells. Following 24 hrs after exposure there is evidence for two populations of responding cells to bystander signals in-and out-of-field. There was no significant difference in DNA damage response between 25%, 50% or 75% modulated fields. The response was dependent on cellular secreted intercellular signalling as physical inhibition of intercellular communication abrogated the observed response. Elevated residual DNA damage observed within out-of-field regions decreased following addition of an inducible nitric oxide synthase inhibitor (Aminoguanidine). These data show, for the first time, differential DNA damage responses in-and out-of-field following modulated radiation field delivery. This study provides further evidence for a role of intercellular communication in mediating cellular radiobiological response to modulated radiation fields and may inform the refinement of existing radiobiological models for the optimization of advanced radiotherapy treatment plans. PMID:22912853

Trainor, Colman; Butterworth, Karl T.; McGarry, Conor K.; McMahon, Stephen J.; O’Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

2012-01-01

155

[Epidemiological findings on health effects of medical radiation exposures].  

PubMed

Various epidemiological studies have been conducted in relation to medical exposures to therapeutic or diagnostic radiation. These studies provide strong evidence for increased risks of breast, thyroid, and other cancers after exposures to several Gy to several tens of Gy from therapeutic radiation. As for exposures to diagnostic radiation, however, there is much less evidence for increased risks of cancer except for those among patients with tuberculosis and scoliosis, as well as thorotrast patients who received moderate dose of radiation (approximately a hundred mGy or more) to organs or sites of interest. Epidemiological studies on medical exposures continue to provide a unique opportunity to look at the possible health effects from fractionated exposures to low to high dose of radiation which the studies of atomic bomb survivors cannot address. PMID:22514917

Yoshinaga, Shinji

2012-03-01

156

ELF exposure facility for human testing  

SciTech Connect

A laboratory facility specifically designed for controlled human exposure to 60-Hz electric (0 to 16 kV/m) and magnetic (0 to 32 A/m, B = 0 to 40 microT) fields has been constructed. The facility presents uniform fields under controlled temperature and humidity. Special control systems allow collection of physiological data during, as well as before and after, exposure to electric fields at strengths to 16 kV/m under verified double-blind control. Exposure to continuous or intermittent fields is possible in the facility. The capability of obtaining physiological data during actual exposure to constant or intermittent, 60-Hz fields, and of doing so without either the subject or the experimenter being aware of actual field conditions, is a critical factor in valid experimentation.

Cohen, H.D.; Graham, C.; Cook, M.R.; Phelps, J.W. (Midwest Research Institute, Kansas City, MO (United States))

1992-01-01

157

HUMAN EXPOSURE ANALYSIS, AN INTERDISCIPLINARY SCIENCE  

EPA Science Inventory

The relatively new and expanding field of human exposure analysis has its genesis in the environmental movement and the interest of scientists and the public in understanding the interaction between anthropogenic and biogenic chemicals and people. The universe is full of chemi...

158

HUMAN EXPOSURE DATABASES DEVELOPMENT AND APPLICATIONS  

EPA Science Inventory

In the past, data from human exposure research studies often resided with the study investigators and the only way the data were disseminated was by publication in EPA reports or peer-reviewed journal manuscripts. Data were often published only as summary statistics with limited...

159

HUMAN EXPOSURE SYSTEM FOR CONTROLLED OZONE ATMOSPHERES  

EPA Science Inventory

An experimental exposure system for health effects research in environmental pollutants that permits the introduction and control of ozone (O3) to an acrylic plastic chamber in which a human subject actively resides is described. Ozone is introduced into the chamber air intake an...

160

MicroRNA Expression Profiling Altered by Variant Dosage of Radiation Exposure  

PubMed Central

Various biological effects are associated with radiation exposure. Irradiated cells may elevate the risk for genetic instability, mutation, and cancer under low levels of radiation exposure, in addition to being able to extend the postradiation side effects in normal tissues. Radiation-induced bystander effect (RIBE) is the focus of rigorous research as it may promote the development of cancer even at low radiation doses. Alterations in the DNA sequence could not explain these biological effects of radiation and it is thought that epigenetics factors may be involved. Indeed, some microRNAs (or miRNAs) have been found to correlate radiation-induced damages and may be potential biomarkers for the various biological effects caused by different levels of radiation exposure. However, the regulatory role that miRNA plays in this aspect remains elusive. In this study, we profiled the expression changes in miRNA under fractionated radiation exposure in human peripheral blood mononuclear cells. By utilizing publicly available microRNA knowledge bases and performing cross validations with our previous gene expression profiling under the same radiation condition, we identified various miRNA-gene interactions specific to different doses of radiation treatment, providing new insights for the molecular underpinnings of radiation injury. PMID:25313363

Lee, Kuei-Fang; Hsu, Paul Wei-Che; Liu, Ingrid Y.; Wu, Lawrence Shih-Hsin

2014-01-01

161

Radiation exposure in gastroenterology: improving patient and staff protection.  

PubMed

Medical imaging involving the use of ionizing radiation has brought enormous benefits to society and patients. In the past several decades, exposure to medical radiation has increased markedly, driven primarily by the use of computed tomography. Ionizing radiation has been linked to carcinogenesis. Whether low-dose medical radiation exposure will result in the development of malignancy is uncertain. This paper reviews the current evidence for such risk, and aims to inform the gastroenterologist of dosages of radiation associated with commonly ordered procedures and diagnostic tests in clinical practice. The use of medical radiation must always be justified and must enable patients to be exposed at the lowest reasonable dose. Recommendations provided herein for minimizing radiation exposure are based on currently available evidence and Working Party expert consensus. PMID:24842339

Ho, Immanuel K H; Cash, Brooks D; Cohen, Henry; Hanauer, Stephen B; Inkster, Michelle; Johnson, David A; Maher, Michael M; Rex, Douglas K; Saad, Abdo; Singh, Ajaypal; Rehani, Madan M; Quigley, Eamonn M

2014-08-01

162

Occupational Exposure to Natural Sources of Ionising Radiation in Ireland  

SciTech Connect

The Radiological Protection Institute of Ireland (RPII) has recently completed a detailed evaluation of all radiation exposure pathways from sources of both natural and artificial radiation in the Irish environment. This paper presents a compilation of the occupational doses received by Irish workers exposed to natural sources of ionising radiation.

Organo, Catherine; Colgan, Tony; Fenton, David; Synnott, Hugh; Currivan, Lorraine [Radiological Protection Institute of Ireland, 3 Clonskeagh Square, Dublin 14 (Ireland)

2008-08-07

163

Exposing Exposure: Automated Anatomy-specific CT Radiation Exposure Extraction for Quality Assurance and Radiation Monitoring  

PubMed Central

Purpose: To develop and validate an informatics toolkit that extracts anatomy-specific computed tomography (CT) radiation exposure metrics (volume CT dose index and dose-length product) from existing digital image archives through optical character recognition of CT dose report screen captures (dose screens) combined with Digital Imaging and Communications in Medicine attributes. Materials and Methods: This institutional review board–approved HIPAA-compliant study was performed in a large urban health care delivery network. Data were drawn from a random sample of CT encounters that occurred between 2000 and 2010; images from these encounters were contained within the enterprise image archive, which encompassed images obtained at an adult academic tertiary referral hospital and its affiliated sites, including a cancer center, a community hospital, and outpatient imaging centers, as well as images imported from other facilities. Software was validated by using 150 randomly selected encounters for each major CT scanner manufacturer, with outcome measures of dose screen retrieval rate (proportion of correctly located dose screens) and anatomic assignment precision (proportion of extracted exposure data with correctly assigned anatomic region, such as head, chest, or abdomen and pelvis). The 95% binomial confidence intervals (CIs) were calculated for discrete proportions, and CIs were derived from the standard error of the mean for continuous variables. After validation, the informatics toolkit was used to populate an exposure repository from a cohort of 54 549 CT encounters; of which 29 948 had available dose screens. Results: Validation yielded a dose screen retrieval rate of 99% (597 of 605 CT encounters; 95% CI: 98%, 100%) and an anatomic assignment precision of 94% (summed DLP fraction correct 563 in 600 CT encounters; 95% CI: 92%, 96%). Patient safety applications of the resulting data repository include benchmarking between institutions, CT protocol quality control and optimization, and cumulative patient- and anatomy-specific radiation exposure monitoring. Conclusion: Large-scale anatomy-specific radiation exposure data repositories can be created with high fidelity from existing digital image archives by using open-source informatics tools. ©RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12111822/-/DC1 PMID:22668563

Warden, Graham I.; Farkas, Cameron E.; Ikuta, Ichiro; Prevedello, Luciano M.; Andriole, Katherine P.; Khorasani, Ramin

2012-01-01

164

75 FR 48274 - Radiation Exposure Compensation Act: Allowance for Costs and Expenses  

Federal Register 2010, 2011, 2012, 2013

...claims pending with the Radiation Exposure Compensation Act...1990, Congress passed the Radiation Exposure Compensation Act...diseases following exposure to radiation released during above-ground atmospheric nuclear weapons tests or...

2010-08-10

165

RADIATION PERMIT APPLICATION Western Human Resources  

E-print Network

1 RADIATION PERMIT APPLICATION Western Human Resources Occupational Health & Safety Please complete the information and send to: Hoa Ly Radiation Safety Coordinator Occupational Health and Safety Room 4190, Support: ________________________ Fax: ___________________________________ Radiation Safety Training and Radiation Work Experience 1

Sinnamon, Gordon J.

166

The Relationship between Ultraviolet Radiation Exposure and Vitamin D Status  

PubMed Central

This paper reviews the main factors influencing the synthesis of vitamin D, with particular focus on ultraviolet radiation exposure. On the global level, the main source of vitamin D is the sun. The effect of solar radiation on vitamin D synthesis depends to some extent on the initial vitamin D levels. At moderate to high latitudes, diet becomes an increasingly important source of vitamin D due to decreased solar intensity and cold temperatures, which discourage skin exposure. During the mid-winter season, these factors result in decreased solar radiation exposure, hindering extensively the synthesis of vitamin D in these populations. PMID:22254036

Engelsen, Ola

2010-01-01

167

Patient radiation exposure during transcatheter aortic valve replacement procedures  

PubMed Central

Aims To describe patient radiation utilisation during transcatheter aortic valve replacement (TAVR) on a series of consecutive patients. Methods and results Data on radiation exposure were prospectively collected for consecutive patients undergoing TAVR and percutaneous coronary interventions at our centre. Radiation dose during the procedure was recorded using the US Food and Drug Administration (FDA) reference point (Ka,r) and the dose area product (PKA). In addition to quantifying overall radiation doses during TAVR, radiation exposure during transfemoral (TF) (n=79) and transapical (TA) (n=26) cases was compared. The median radiation dose during TAVR was 1,639 mGy (983–2,420), or 188 (106–321) Gy*cm2. Radiation dose was significantly lower among TA patients using either the reference point (TA: 946 [777–1,261] vs. TF: 1,932 [1,383–2,614] mGy; p<0.001) or the dose area product (TA: 89 [60–115] vs. TF: 236 [164–338] Gy*cm2; p<0.001). Fluoroscopy time was lower for TA patients (TA: 10 [8–11] vs. TF: 30 [24–34] minutes; p<0.001). Operators experience did not affect radiation exposure for TF cases. Conclusions Radiation exposure during TAVR appears similar to other percutaneous coronary interventions of moderate complexity. Radiation doses were significantly lower for TA procedures. A higher dose of radiation in TF patients may be related to additional imaging requirements to optimise percutaneous vascular access and closure. PMID:23086785

Daneault, Benoit; Balter, Stephen; Kodali, Susheel K.; Williams, Mathew R.; Généreux, Philippe; Reiss, George R.; Paradis, Jean-Michel; Green, Philip; Kirtane, Ajay J.; Smith, Craig; Moses, Jeffrey W.; Leon, Martin B.

2013-01-01

168

Human exposure to urban air pollution.  

PubMed Central

This study deals with some methods of making human exposure estimates, aimed at describing the human exposure for selected air pollutants in Sweden that are suspected carcinogens. Nitrogen oxides (NOx) have been chosen as an indicator substance for estimating the concentration of the urban plume. Earlier investigations have shown that the traffic in Swedish cities contributes around 85% to the measured NOx concentrations, and that most of the mutagenicity in urban air originates from traffic. The first section of this paper describes measurements in Stockholm of some unregulated light hydrocarbons, such as ethene, ethyne, propane, propene, butane, and isobutane. In addition, measurements of some volatile aromatic hydrocarbons are presented. Simultaneous measurements of carbon monoxide (CO) were made. The ratios between CO and the individual specific compounds were determined by linear regression analysis. By analysis of relationships between CO and NOx, NOx concentrations can be used as a tracer to describe the exposure for these specific compounds. NOx are considered to be a better tracer than CO, because NOx or NO2 values exist for many places over a long time, while CO is measured mostly in streets with high concentrations. At low concentrations, instruments that measure normal CO levels give no detectable signals. Through use of atmospheric dispersion models and models that describe how people live and work in urban areas it has been possible to describe the average exposure to NOx in cities of different sizes. The exposure to NOx for people living in the countryside has also been estimated. In this way, it has been possible to calculate the average exposure dose for NOx for the Swedish population. This figure is 23 micrograms/m3. By use of the relationships between NOx and specific compounds the average dose has been calculated for the following compounds: polyaromatic compounds (PAH); ethene, propene, and butadiene; benzene, toluene, and xylene; formaldehyde and actaldehyde; nickel, chromium (VI), arsenic, and cadmium; asbestos; and silicon. PMID:7821294

Boström, C E; Almén, J; Steen, B; Westerholm, R

1994-01-01

169

Calculating human exposure to endocrine disrupting pesticides via agricultural and non-agricultural exposure routes  

Microsoft Academic Search

Endocrine Disrupting Chemicals (EDCs) are of increasing concern because of their potential impacts on the environment, wildlife and human health. Pesticides and some pesticide metabolites are an important group of EDC, and exposure to them is a poorly quantified source of human and environmental exposure to such chemicals generally. Models for estimating human exposure to Endocrine Disrupting (ED) pesticides are

R. McKinlay; J. A. Plant; J. N. B. Bell; N. Voulvoulis

2008-01-01

170

Nuclear Fragmentation Processes Relevant for Human Space Radiation Protection  

NASA Technical Reports Server (NTRS)

Space radiation from cosmic ray particles is one of the main challenges for human space explorations such-as a moon base or a trip to Mars. Models have been developed in order to predict the radiation exposure to astronauts and to evaluate the effectiveness of different shielding materials, and a key ingredient in these models is the physics of nuclear fragmentations. We have developed a semi-analytical method to determine which partial cross sections of nuclear fragmentations most affect the radiation dose behind shielding materials due to exposure to galactic cosmic rays. The cross sections thus determined will require more theoretical and/or experimental studies in order for us to better predict, reduce and mitigate the radiation exposure in human space explorations.

Lin, Zi-Wei

2007-01-01

171

DOE 2010 Occupational Radiation Exposure November 2011  

SciTech Connect

This report discusses radiation protection and dose reporting requirements, presents the 2010 occupational radiation dose data trended over the past 5 years, and includes instructions to submit successful ALARA projects.

U.S. Department of Energy, Office of Health, Safety and Security, Office of Analysis

2011-11-11

172

Gene Expression Profiling of Biological Pathway Alterations by Radiation Exposure  

PubMed Central

Though damage caused by radiation has been the focus of rigorous research, the mechanisms through which radiation exerts harmful effects on cells are complex and not well-understood. In particular, the influence of low dose radiation exposure on the regulation of genes and pathways remains unclear. In an attempt to investigate the molecular alterations induced by varying doses of radiation, a genome-wide expression analysis was conducted. Peripheral blood mononuclear cells were collected from five participants and each sample was subjected to 0.5?Gy, 1?Gy, 2.5?Gy, and 5?Gy of cobalt 60 radiation, followed by array-based expression profiling. Gene set enrichment analysis indicated that the immune system and cancer development pathways appeared to be the major affected targets by radiation exposure. Therefore, 1?Gy radioactive exposure seemed to be a critical threshold dosage. In fact, after 1?Gy radiation exposure, expression levels of several genes including FADD, TNFRSF10B, TNFRSF8, TNFRSF10A, TNFSF10, TNFSF8, CASP1, and CASP4 that are associated with carcinogenesis and metabolic disorders showed significant alterations. Our results suggest that exposure to low-dose radiation may elicit changes in metabolic and immune pathways, potentially increasing the risk of immune dysfunctions and metabolic disorders. PMID:25276823

Lee, Kuei-Fang; Weng, Julia Tzu-Ya; Hsu, Paul Wei-Che; Chi, Yu-Hsiang; Chen, Ching-Kai; Liu, Ingrid Y.; Chen, Yi-Cheng; Wu, Lawrence Shih-Hsin

2014-01-01

173

I-131 Radiation Exposure - National Cancer Institute (NCI)  

Cancer.gov

This calculator estimates the radiation dose from I-131 absorbed by your thyroid gland from nuclear tests conducted at the Nevada Test Site (NTS). The calculator estimates your risk of thyroid cancer from this exposure.

174

Exposure safety standards for nonionizing radiation (NIR) from collision-avoidance radar  

NASA Astrophysics Data System (ADS)

On-vehicle technology for collision avoidance using millimeter wave radar is currently under development and is expected to be in vehicles in coming years. Recently approved radar bands for collision avoidance applications include 47.5 - 47.8 GHz and 76 - 77 GHz. Widespread use of active radiation sources in the public domain would contribute to raised levels of human exposure to high frequency electromagnetic radiation, with potential for adverse health effects. In order to design collision avoidance systems that will pose an acceptably low radiation hazard, it is necessary to determine what levels of electromagnetic radiation at millimeter wave frequencies will be acceptable in the environment. This paper will summarize recent research on NIR (non-ionizing radiation) exposure safety standards for high frequency electromagnetic radiation. We have investigated both governmental and non- governmental professional organizations worldwide.

Palmer-Fortune, Joyce; Brecher, Aviva; Spencer, Paul; Huguenin, Richard; Woods, Ken

1997-02-01

175

Radiation metabolomics. 5. Identification of urinary biomarkers of ionizing radiation exposure in nonhuman primates by mass spectrometry-based metabolomics.  

PubMed

Mass spectrometry-based metabolomics has previously demonstrated utility for identifying biomarkers of ionizing radiation exposure in cellular, mouse and rat in vivo radiation models. To provide a valuable link from small laboratory rodents to humans, ?-radiation-induced urinary biomarkers were investigated using a nonhuman primate total-body-irradiation model. Mass spectrometry-based metabolomics approaches were applied to determine whether biomarkers could be identified, as well as the previously discovered rodent biomarkers of ? radiation. Ultra-performance liquid chromatography-electrospray ionization quadrupole time-of-flight mass spectrometry analysis was carried out on a time course of clean-catch urine samples collected from nonhuman primates (n = 6 per cohort) exposed to sham, 1.0, 3.5, 6.5 or 8.5 Gy doses of (60)Co ? ray (?0.55 Gy/min) ionizing radiation. By multivariate data analysis, 13 biomarkers of radiation were discovered: N-acetyltaurine, isethionic acid, taurine, xanthine, hypoxanthine, uric acid, creatine, creatinine, tyrosol sulfate, 3-hydroxytyrosol sulfate, tyramine sulfate, N-acetylserotonin sulfate, and adipic acid. N-Acetyltaurine, isethionic acid, and taurine had previously been identified in rats, and taurine and xanthine in mice after ionizing radiation exposure. Mass spectrometry-based metabolomics has thus successfully revealed and verified urinary biomarkers of ionizing radiation exposure in the nonhuman primate for the first time, which indicates possible mechanisms for ionizing radiation injury. PMID:22954391

Johnson, Caroline H; Patterson, Andrew D; Krausz, Kristopher W; Kalinich, John F; Tyburski, John B; Kang, Dong Wook; Luecke, Hans; Gonzalez, Frank J; Blakely, William F; Idle, Jeffrey R

2012-10-01

176

Personnel exposure to radiation at some angiographic procedures  

SciTech Connect

Personnel exposure to radiation was investigated during radiological procedures where x-ray shielding is particularly difficult. Ten percutaneous transhepatic cholangiographies, four percutaneous transhepatic portographies, and four coronary angiographies are included in the study. Exposure to radiation was measured at several anatomical sites for both the radiologist and the assisting nurse. Effective dose equivalents as proposed by the International Commission on Radiological Protection (ICRP) were estimated from the registered absorbed doses.

Gustafsson, M.; Lunderquist, A.

1981-09-01

177

Estimates of Carrington-class solar particle event radiation exposures on Mars  

NASA Astrophysics Data System (ADS)

Radiation exposure estimates for crew members on the surface of Mars are made for solar particle event proton radiation environments comparable to the Carrington event of 1859. We assume that the proton energy distributions for these Carrington-type events are similar to those measured for other, more recent large events. The fluence levels of these hypothetical events are normalized to the value for the Carrington event, as reported from measurements in ice core data. In this work, we use the BRYNTRN radiation transport code, originally developed at NASA Langley Research Center, and the Computerized Anatomical Male and Female human geometry models to estimate exposures for aluminum shield areal densities similar to those provided by a spacesuit, a surface lander, and a permanent habitat located at various altitudes in the Mars atmosphere. Comparisons of the predicted organ exposures with current NASA Permissible Exposure Limits are made.

Townsend, L. W.; Pourarsalan, M.; Hall, M. I.; Anderson, J. A.; Bhatt, S.; Delauder, N.; Adamczyk, A. M.

2011-09-01

178

Exposure of aircrew to cosmic radiation. Calculation and experimental approach  

Microsoft Academic Search

Exposure to cosmic radiation increases rapidly with the altitude. At the flight levels of commercial aircraft, it is of the order of several ?Sv per hour. Most aircrews are exposed regularly to the effective dose exceeding 1 mSv\\/year, the limit of exposure for nonprofessionals defined in the International Commission on Radiological Protection (ICRP) 60 recommendations, which were already incorporated to

František Spurný

2002-01-01

179

Non-targeted and delayed effects of exposure to ionizing radiation: II. Radiation-induced genomic instability and bystander effects in vivo, clastogenic factors and transgenerational effects  

NASA Technical Reports Server (NTRS)

The goal of this review is to summarize the evidence for non-targeted and delayed effects of exposure to ionizing radiation in vivo. Currently, human health risks associated with radiation exposures are based primarily on the assumption that the detrimental effects of radiation occur in irradiated cells. Over the years a number of non-targeted effects of radiation exposure in vivo have been described that challenge this concept. These include radiation-induced genomic instability, bystander effects, clastogenic factors produced in plasma from irradiated individuals that can cause chromosomal damage when cultured with nonirradiated cells, and transgenerational effects of parental irradiation that can manifest in the progeny. These effects pose new challenges to evaluating the risk(s) associated with radiation exposure and understanding radiation-induced carcinogenesis.

Morgan, William F.

2003-01-01

180

Cumulative effects from repeated exposures to suberythemal doses of UVB and UVA in human skin  

Microsoft Academic Search

Background: The skin is repeatedly exposed to solar UV radiation. Long-term photodamage is a consequence of cumulative UV radiation injury. Hence an examination of the repetitive effects of UV exposure is more likely to yield clues to the early alterations that lead to photoaged skin than a single exposure.Objective: We examined the effects of repetitive low-dose UV irradiation on human

Robert M Lavker; G. Frank Gerberick; Denise Veres; Chris J Irwin; Kays H Kaidbey

1995-01-01

181

Biological and biophysical techniques to assess radiation exposure: a perspective.  

PubMed

Biological dosimeters measure biologically relevant effects of radiation exposure that are in some sense an estimate of effective dose, whereas biophysical indicators serve as surrogates of absorbed dose in a manner analogous to conventional thermoluminescent dosimeters (TLD). The biological and biophysical dosimeters have the potential to play an important role in assessing unanticipated or occupational radiation exposures. For example, where the exposure is large and uncertain (i.e. radiation accidents), accurate dose information can help in deciding the most appropriate therapy and medical treatment. Another useful area is that of lifetime accumulated dose determination, and the ability to distinguish between and integrate the exposures from natural and anthropogenic (medical X-rays, indoor radon, natural background radiation, occupational and non-occupational exposures). Also, the possibility to monitor individual response and differences in inherent or induced radiation sensitivity may have important implications for radiation protection. More commonly, this type of dosimetry could be used for routine monitoring to detect and quantify unsuspected exposure, for regulatory purposes or for epidemiological studies of the long-term effects of radiation exposure (e.g. in Japanese A-bomb survivors or in the population surrounding Chernobyl). This review is a comparative study of the existing techniques and their future prospects. It summarizes the sensitivity, reproducibility, limiting dose, dose-rate, energy, LET response, sources of variability and uncertainty, and other practical aspects of each bio-indicator. The strengths and weaknesses of each approach are evaluated on the basis of common criteria for particular applications, and are summarized for each assay both in the text and in tabular form, for convenience. It is clear that no single indicator qualifies to reliably measure occupational exposures at the current levels of sensitivity conventional dosimetry services provide. Most of the bio-techniques are applicable to the detection of relatively high radiation exposures at relatively short times after exposure. Some of the bio-indicators have been identified that are, or offer future prospects for becoming, appropriate bio-indicators for dosimetry needs. However, all methods are subject to biological and other variables that are presently uncontrolled, and represent a major source of uncertainty. These include variations in background signals not directly associated with radiation exposure, inter- and intra-individual variability of radiation response, and genetic and environmental effects. Although these factors contribute to the lack of confidence in biological dosimetry, promising bio-indicators may be applied to large populations to establish the inherent variability and confounding factors that limit quantitative data collection and analysis, and reduce reliability and reproducibility. PMID:8029472

Greenstock, C L; Trivedi, A

1994-01-01

182

Characterization of the dose response relationship for lung injury following acute radiation exposure in three well-established murine strains: developing an interspecies bridge to link animal models with human lung.  

PubMed

Approval of radiation countermeasures through the FDA Animal Rule requires pivotal efficacy screening in one or more species that are expected to react with a response similar to humans (21 C.F.R. § 314.610, drugs; § 601.91, biologics). Animal models used in screening studies should reflect the dose response relationship (DRR), clinical presentation, and pathogenesis of lung injury in humans. Over the past 5 y, the authors have characterized systematically the temporal onset, dose-response relationship (DRR), and pathologic outcomes associated with acute, high dose radiation exposure in three diverse mouse strains. In these studies, C57L/J, CBA/J, and C57BL/6J mice received wide field irradiation to the whole thorax with shielding of the head, abdomen, and forelimbs. Doses were delivered at a rate of 69 cGy min using an x-ray source operated at 320 kVp with half-value layer (HVL) of 1 mm Cu. For all strains, radiation dose was associated significantly with 180 d mortality (p < 0.0001). The lethal dose for 50% of animals within the first 180 d (LD50/180) was 11.35 Gy (95% CI 11.1-11.6 Gy) for C57L/J mice, 14.17 Gy (95% CI 13.9-14.5 Gy) for CBA/J mice, and 14.10 Gy (95% CI 12.2-16.4 Gy) for C57BL/6J mice. The LD50/180 in the C57L/J strain was most closely analogous to the DRR for clinical incidence of pneumonitis in non-human primates (10.28 Gy; 95% CI 9.9-10.7 Gy) and humans (10.60 Gy; 95% CI 9.9-12.1 Gy). Furthermore, in the C57L/J strain, there was no gender-specific difference in DRR (p = 0.5578). The reliability of the murine models is demonstrated by the reproducibility of the dose-response and consistency of disease presentation across studies.Health Phys. 106(1):000-000; 2014. PMID:24276549

Jackson, Isabel L; Xu, Pu-Ting; Nguyen, Giao; Down, Julian D; Johnson, Cynthia S; Katz, Barry P; Hadley, Caroline C; Vujaskovic, Zeljko

2014-01-01

183

Biomarkers of human exposure to pesticides.  

PubMed Central

For centuries, several hundred pesticides have been used to control insects. These pesticides differ greatly in their mode of action, uptake by the body, metabolism, elimination from the body, and toxicity to humans. Potential exposure from the environment can be estimated by environmental monitoring. Actual exposure (uptake) is measured by the biological monitoring of human tissues and body fluids. Biomarkers are used to detect the effects of pesticides before adverse clinical health effects occur. Pesticides and their metabolites are measured in biological samples, serum, fat, urine, blood, or breast milk by the usual analytical techniques. Biochemical responses to environmental chemicals provide a measure of toxic effect. A widely used biochemical biomarker, cholinesterase depression, measures exposure to organophosphorus insecticides. Techniques that measure DNA damage (e.g., detection of DNA adducts) provide a powerful tool in measuring environmental effects. Adducts to hemoglobin have been detected with several pesticides. Determination of chromosomal aberration rates in cultured lymphocytes is an established method of monitoring populations occupationally or environmentally exposed to known or suspected mutagenic-carcinogenic agents. There are several studies on the cytogenetic effects of work with pesticide formulations. The majority of these studies report increases in the frequency of chromosomal aberrations and/or sister chromatid exchanges among the exposed workers. Biomarkers will have a major impact on the study of environmental risk factors. The basic aim of scientists exploring these issues is to determine the nature and consequences of genetic change or variation, with the ultimate purpose of predicting or preventing disease. PMID:9255564

Anwar, W A

1997-01-01

184

Inferring ultraviolet anatomical exposure patterns while distinguishing the relative contribution of radiation components  

NASA Astrophysics Data System (ADS)

Exposure to solar ultraviolet (UV) radiation is the main causative factor for skin cancer. UV exposure depends on environmental and individual factors, but individual exposure data remain scarce. While ground UV irradiance is monitored via different techniques, it is difficult to translate such observations into human UV exposure or dose because of confounding factors. A multi-disciplinary collaboration developed a model predicting the dose and distribution of UV exposure on the basis of ground irradiation and morphological data. Standard 3D computer graphics techniques were adapted to develop a simulation tool that estimates solar exposure of a virtual manikin depicted as a triangle mesh surface. The amount of solar energy received by various body locations is computed for direct, diffuse and reflected radiation separately. Dosimetric measurements obtained in field conditions were used to assess the model performance. The model predicted exposure to solar UV adequately with a symmetric mean absolute percentage error of 13% and half of the predictions within 17% range of the measurements. Using this tool, solar UV exposure patterns were investigated with respect to the relative contribution of the direct, diffuse and reflected radiation. Exposure doses for various body parts and exposure scenarios of a standing individual were assessed using erythemally-weighted UV ground irradiance data measured in 2009 at Payerne, Switzerland as input. For most anatomical sites, mean daily doses were high (typically 6.2-14.6 Standard Erythemal Dose, SED) and exceeded recommended exposure values. Direct exposure was important during specific periods (e.g. midday during summer), but contributed moderately to the annual dose, ranging from 15 to 24% for vertical and horizontal body parts, respectively. Diffuse irradiation explained about 80% of the cumulative annual exposure dose.

Vuilleumier, Laurent; Milon, Antoine; Bulliard, Jean-Luc; Moccozet, Laurent; Vernez, David

2013-05-01

185

Impact of long-term exposure to sodium arsenite on cytogenetic radiation damage.  

PubMed

The aim of this work was to investigate the impact of long-term exposure to low concentrations of sodium arsenite on the cellular response to ionising radiation. Human lymphoblastoid GM1899a cells were cultured in the presence of sodium arsenite for up to six months. Following chemical exposure, acute challenge doses of X-rays were given and chromosome damage (dicentrics, acentric fragments, translocations, micronuclei) as well as cell growth and changes in cell cycle kinetics were determined. Initial short-term chemical exposures determined 8 ng/ml (60 nM) sodium arsenite as a suitable concentration for chronic exposures, which is below the current World Health Organization limit for arsenic in drinking water. At this concentration, cell growth was slightly, but consistently, slower than in untreated cultures throughout the six-month exposure period. Long-term exposure to the chemical induced no dicentrics and did not significantly alter the yield of dicentrics induced by 1 Gy acute X-irradiation. Similar results were obtained for chromosome translocations. In contrast, exposure to 8 ng/ml sodium arsenite induced significant levels of acentric fragments and micronuclei. Fragment/micronuclei data in combined treatment samples compared with single treatments were consistent with an additive effect of chemical and radiation exposure. As for X-rays, micronuclei induced by sodium arsenite tended to show no centromere in situ hybridisation signal, indicating that they represent structural aberrations rather than mis-segregated chromosomes. Similar results were obtained in human peripheral lymphocytes following short-term exposure to sodium arsenite or X-rays. Overall, an additive effect was observed for all combined exposures. Cellular radiation responses therefore seem to operate without any modulatory effects from chronic low level exposure to sodium arsenite in the systems analysed here. PMID:24452505

Nuta, Otilia; Moquet, Jayne; Bouffler, Simon; Lloyd, David; Sepai, Ovnair; Rothkamm, Kai

2014-03-01

186

Charged particle radiation exposure of geocentric satellites  

NASA Technical Reports Server (NTRS)

The near-earth radiation environment is characterized, summarizing published data on trapped and transient charged particles and their potential effects on hardware systems and the crews of manned missions. Topics examined include the role of the magnetosphere, the five radiation domains, cyclic and sporadic variations in the radiation environment, the potential effect of a high-altitude nuclear explosion, NASA empirical models for predicting trapped proton and electron fluxes, and the South Atlantic anomaly and the estimation of flux-free periods. Consideration is given to solar cosmic rays and heavy ions, Galactic cosmic rays, geomagnetic shielding, secondary radiation, the design of shielding systems, variables affecting dose evaluations, and ionizing-radiation doses. Extensive diagrams, graphs, and tables of numerical data are provided.

Stassinopoulos, E. G.

1989-01-01

187

Risk assessment and management of radiofrequency radiation exposure  

NASA Astrophysics Data System (ADS)

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

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

2013-11-01

188

Risk assessment and management of radiofrequency radiation exposure  

SciTech Connect

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

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

2013-11-13

189

Effects of parental radiation exposure on developmental instability in grasshoppers  

PubMed Central

Mutagenic and epigenetic effects of environmental stressors and their transgenerational consequences are of interest to evolutionary biologists because they can amplify natural genetic variation. We studied the effect of parental exposure to radioactive contamination on offspring development in lesser marsh grasshopper Chorthippus albomarginatus. We used a geometric morphometric approach to measure fluctuating asymmetry (FA), wing shape and wing size. We measured time to sexual maturity to check whether parental exposure to radiation influenced offspring developmental trajectory and tested effects of radiation on hatching success and parental fecundity. Wings were larger in early maturing individuals born to parents from high radiation sites compared to early maturing individuals from low radiation sites. As time to sexual maturity increased, wing size decreased but more sharply in individuals from high radiation sites. Radiation exposure did not significantly affect FA or shape in wings nor did it significantly affect hatching success and fecundity. Overall, parental radiation exposure can adversely affect offspring development and fitness depending on developmental trajectories although the cause of this effect remains unclear. We suggest more direct measures of fitness and the inclusion of replication in future studies to help further our understanding of the relationship between developmental instability, fitness and environmental stress. PMID:22507690

BEASLEY, D. E.; BONISOLI-ALQUATI, A.; WELCH, S. M.; MØLLER, A. P.; MOUSSEAU, T. A.

2014-01-01

190

NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS): OPPORTUNITIES AND LESSONS LEARNED  

EPA Science Inventory

The National Human Exposure Assessment Survey (NHEXAS) in its fullest sense is a conceptual design, which upon implementation, will have long-term implications to exposure research and assessment. The ultimate goal is to document national distribution of human exposure to pote...

191

Inter-individual variation in DNA double-strand break repair in human fibroblasts before and after exposure to low doses of ionizing radiation  

Microsoft Academic Search

DNA double-strand breaks (DSB) are generally considered the most critical lesion induced by ionizing radiation (IR) and may initiate carcinogenesis and other disease. Using an immunofluorescence assay to simultaneously detect nuclear foci of the phosphorylated forms of histone H2AX and ATM kinase at sites of DSBs, we examined the response of 25 apparently normal and 10 DNA repair-deficient (ATM, ATR,

Paul F. Wilson; Peter B. Nham; Salustra S. Urbin; John M. Hinz; Irene M. Jones; Larry H. Thompson

2010-01-01

192

Assessment of human exposure to gaseous pollutants  

SciTech Connect

A mathematical model to aid in assessment of human environmental exposure to volatile organic substances is presented. The model simulates the convective and diffusive transport of gas from the ambient environment into the human body by way of the respiratory and circulatory systems. Data required include easily obtained physical and chemical properties of substances as well as several estimated or measured physiological parameters. Transient and steady-state tissue concentrations resulting from an input atmospheric partial pressure are predicted. From these concentrations, an effective dose may be calculated, allowing for the determination of an exposure-response relationship based upon independently obtained dose-response data. The model's results compare favorably to experimental data on oxygen and halothane. Steady-state conditions are reached very rapidly. These results suggest that uptake of these substances is limited by both ventilation and perfusion. Rates are demonstrated to be essentially linear within the current neighborhoods. Conditions in which the primary processes of ventilation, diffusion, perfusion, and elimination limit uptake of gases are considered. Expressions describing the conditions necessary for a single process to limit gas uptake are derived. Accompanying equations for estimating tissue concentrations under these limiting conditions are presented.

Baskin, L.B.; Falco, J.W. (Parkland Memorial Hospital, Dallas, TX (USA))

1989-09-01

193

Radiation protection aspects of the cosmic radiation exposure of aircraft crew.  

PubMed

Aircraft crew and frequent flyers are exposed to elevated levels of cosmic radiation of galactic and solar origin and secondary radiation produced in the atmosphere, the aircraft structure and its contents. Following recommendations of the International Commission on Radiological Protection in Publication 60, the European Union introduced a revised Basic Safety Standards Directive, which included exposure to natural sources of ionising radiation, including cosmic radiation, as occupational exposure. The revised Directive has been incorporated into laws and regulations in the European Union Member States. Where the assessment of the occupational exposure of aircraft crew is necessary, the preferred approach to monitoring is by the recording of staff flying times and calculated route doses. Route doses are to be validated by measurements. This paper gives the general background, and considers the radiation protection aspects of the cosmic radiation exposure of aircraft crew, with the focus on the situation in Europe. PMID:15273353

Bartlett, D T

2004-01-01

194

Assessing radiation exposure during endoscopic-guided percutaneous nephrolithotomy  

PubMed Central

Introduction: Percutaneous nephrolithotomy (PCNL) may be associated with significant ionizing radiation exposure for patients and operating room staff. Endoscopic-guided PCNL (ePCNL) is a technique that may be associated with less radiation exposure. This study examines ePCNL-related radiation exposure (fluoroscopy time, effective dose) and investigates variables that may predict increased exposure. Methods: A retrospective review of all consecutive ePCNLs performed at our institution, by a single surgeon, was conducted between November 2011 and November 2013. Patient demographics, stone characteristics and perioperative details were recorded, including radiation exposure. Pearson and Spearman correlation were used to assess variables correlated with radiation exposure. Results: In total, 55 ePCNL cases were included in the study. The mean age was 60 ± 15 years, mean body mass index (BMI) 30.0 ± 6.4 kg/m2 and mean stone size 3.2 × 2.1 cm. Seven cases (13%) involved complete staghorn stones, and 69% involved supracostal punctures. The mean fluoroscopy time was 3.4 ± 2.3 minutes, mean ED 2.4 ± 1.9 mSv. The treatment success rate, assessed 1-week postoperatively, was 87.3% and 7.3% of cases required ancillary procedures. The overall complication rate was 29%, but only 3 cases (5.5%) were Clavien ?3. Longer fluoroscopy time correlated with increased stone size (p < 0.01), longer operative time (p < 0.01) and lower treatment success rates (p < 0.01); higher effective dose correlated with longer fluoroscopy time (p < 0.01) and increased skin-to-stone distance (p < 0.01). BMI did not correlate with fluoroscopy time or effective dose. Conclusions: Outcomes of ePCNL are comparable to traditional PCNL techniques and may be associated with lower radiation exposure, particularly beneficial for patients with higher BMI. PMID:25408802

Lantz, Andrea G.; O’Malley, Padraic; Ordon, Michael; Lee, Jason Y.

2014-01-01

195

ANALYSIS OF THE DISTRIBUTION AND DOSE RESPONSE OF CHROMOSOME ABERRATIONS IN HUMAN LYMPHOCYTES AFTER IN VITRO EXPOSURE TO (137) CESIUM GAMMA RADIATION  

EPA Science Inventory

The chromosome aberration yield for human lymphocytes exposed in vitro to various doses of (137) Cesium has been studied. Dicentric, total acentric, and excess acentric data were seen to follow a Poisson distribution. Calculated total hits demonstrated over-dispersion which could...

196

HUMAN BIOMONITORING TO LINK ENVIRONMENTAL EXPOSURE TO BIOLOGICALLY RELEVANT DOSE  

EPA Science Inventory

The abstract and presentation on Human Biomonitoring to Link Environmental Exposure to Biologically Relevant Dose describes the use of biomarkers of exposure, biomarkers of current health state, and biomarker measurements. The abstract and presentation focuses on how biomarkers ...

197

NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) DATA ANALYSIS WORK GROUP  

EPA Science Inventory

Three field studies were under conducted the National Human Exposure Assessment Survey. These studies measured exposures in three study regions - Arizona, the six EPA Region V States (Ohio, Indiana, Michigan, Illinois, Wisconsin, Minnesota), and Baltimore and four surrounding cou...

198

Porphyrin Metabolisms in Human Skin Commensal Propionibacterium acnes Bacteria: Potential Application to Monitor Human Radiation Risk  

PubMed Central

Propionibacterium acnes (P. acnes), a Gram-positive anaerobic bacterium, is a commensal organism in human skin. Like human cells, the bacteria produce porphyrins, which exhibit fluorescence properties and make bacteria visible with a Wood’s lamp. In this review, we compare the porphyrin biosynthesis in humans and P. acnes. Also, since P. acnes living on the surface of skin receive the same radiation exposure as humans, we envision that the changes in porphyrin profiles (the absorption spectra and/or metabolism) of P. acnes by radiation may mirror the response of human cells to radiation. The porphyrin profiles of P. acnes may be a more accurate reflection of radiation risk to the patient than other biodosimeters/biomarkers such as gene up-/down-regulation, which may be non-specific due to patient related factors such as autoimmune diseases. Lastly, we discuss the challenges and possible solutions for using the P. acnes response to predict the radiation risk. PMID:23231351

Shu, M.; Kuo, S.; Wang, Y.; Jiang, Y.; Liu, Y.-T.; Gallo, R.L.; Huang, C.-M.

2013-01-01

199

Cumulative radiation exposure in pediatric patients with congenital heart disease.  

PubMed

Certain pediatric patients undergoing surgery for the most severe forms of congenital heart disease are exposed to high doses of ionizing radiation. The amount of cumulative radiation exposure from all modalities has not yet been evaluated. The purpose of our study was to evaluate the cumulative radiation exposure in a contemporary cohort of patients with congenital heart disease undergoing single-ventricle palliation. This is a single-center, retrospective study of pediatric patients undergoing Fontan completion between May 2005 and May 2010. Radiation exposure from all procedures including cardiac catheterizations, computed tomography (CT) scans, plain film radiography, and nuclear medicine scans was evaluated. Radiation dose was calculated as the dose area product (?Gy m(2)) and was measured in all cardiac catheterizations, CT scans, and other imaging modalities. Seventy patients who underwent Fontan completion at a mean age of 3.6 ± 1.5 years (range 1.4-8 years) were included in the study. Mean number of chest X-rays was 32 ± 8 (range 10-285) with a mean cumulative total exposure of 1,320 ?Gy m(2) (range 480-12,960) per patient. Mean number of cardiac catheterizations was 2.45 ± 1.3 (range 1-8), and mean fluoroscopy and cine angiography exposures per case were 1,103 ± 245 and 1,412 ± 273 ?Gy m(2) giving a mean cumulative exposure of 9,054 ?Gy m(2) (range 2,515-201,200) per patient for all catheterizations. Mean number of CT scans performed was 0.44 ± 0.4 (0-11), and the mean exposure was 352 ?Gy m(2), giving a mean cumulative total of 154 ?Gy m(2) (range 0-3,872) per person. A total of five lung perfusion scans were carried out. Radiation exposure in patients with congenital heart disease undergoing single-ventricle palliation is quite variable. Most of the exposure to ionizing radiation occurs during cardiac catheterization. Strategies to utilize other imaging modalities such as MRI would decrease exposure in this particular group of patients who may be particularly vulnerable to its side effects. PMID:25124721

Walsh, Mark A; Noga, Michelle; Rutledge, Jennifer

2015-02-01

200

Exposure to Mobile Phone Radiation Opens New Horizons in Alzheimer’s Disease Treatment  

PubMed Central

Alzheimer’s disease, the most common type of dementia and a progressive neurodegenerative disease, occurs when the nerve cells in the brain die. Although there are medications that can help delay the development of Alzheimer’s disease, there is currently no cure for this disease. Exposure to ionizing and non-ionizing radiation may cause adverse health effects such as cancer.  Looking at the other side of the coin, there are reports indicating stimulatory or beneficial effects after exposure to cell phone radiofrequency radiation. Mortazavi et al. have previously reported some beneficial cognitive effects such as decreased reaction time after human short-term exposure to cell phone radiation or occupational exposure to radar microwave radiation. On the other hand, some recent reports have indicated that RF radiation may have a role in protecting against cognitive impairment in Alzheimer’s disease. Although the majority of these data come from animal studies that cannot be easily extrapolated to humans, it can be concluded that this memory enhancing approach may open new horizons in treatment of cognitive impairment in Alzheimer disease. PMID:25505755

Mortazavi, SAR; Shojaei-Fard, MB; Haghani, M; Shokrpour, N; Mortazavi, SMJ

2013-01-01

201

Exposure to mobile phone radiation opens new horizons in Alzheimer's disease treatment.  

PubMed

Alzheimer's disease, the most common type of dementia and a progressive neurodegenerative disease, occurs when the nerve cells in the brain die. Although there are medications that can help delay the development of Alzheimer's disease, there is currently no cure for this disease. Exposure to ionizing and non-ionizing radiation may cause adverse health effects such as cancer.  Looking at the other side of the coin, there are reports indicating stimulatory or beneficial effects after exposure to cell phone radiofrequency radiation. Mortazavi et al. have previously reported some beneficial cognitive effects such as decreased reaction time after human short-term exposure to cell phone radiation or occupational exposure to radar microwave radiation. On the other hand, some recent reports have indicated that RF radiation may have a role in protecting against cognitive impairment in Alzheimer's disease. Although the majority of these data come from animal studies that cannot be easily extrapolated to humans, it can be concluded that this memory enhancing approach may open new horizons in treatment of cognitive impairment in Alzheimer disease. PMID:25505755

Mortazavi, Sar; Shojaei-Fard, Mb; Haghani, M; Shokrpour, N; Mortazavi, Smj

2013-09-01

202

NASA Human Research Program Space Radiation Program Element  

NASA Technical Reports Server (NTRS)

The goal of the NASA Human Research Program's Space Radiation Program Element is to ensure that crews can safely live and work in the space radiation environment. Current work is focused on developing the knowledge base and tools required for accurate assessment of health risks resulting from space radiation exposure including cancer and circulatory and central nervous system diseases, as well as acute risks from solar particle events. Division of Space Life Sciences (DSLS) Space Radiation Team scientists work at multiple levels to advance this goal, with major projects in biological risk research; epidemiology; and physical, biophysical, and biological modeling.

Chappell, Lori; Huff, Janice; Patel, Janapriya; Wang, Minli; Hu, Shaowwen; Kidane, Yared; Myung-Hee, Kim; Li, Yongfeng; Nounu, Hatem; Plante, Ianik; Ponomarev, Artem; Hada, Megumi

2013-01-01

203

Radiation exposure during the lateral lumbar interbody fusion procedure and techniques to reduce radiation dosage  

PubMed Central

Background Fluoroscopy is widely used in spine surgery to assist with graft and hardware placement. Previous studies have not measured radiation exposure to a surgeon during minimally invasive lateral lumbar spine surgery for single-level discectomy and interbody cage insertion. This study was performed to model and measure radiation exposure to a surgeon during spine surgery using the direct lateral lumbar procedure. Methods The study was performed using a mannequin substituting for the surgeon and a cadaver substituting for the patient. Radiation was measured with dosimeters attached to 6 locations on the mannequin using a OEC Medical Systems 9800 C-arm fluoroscope (OEC Medical Systems, Salt Lake City, Utah). Three different fluoroscopy setups were tested: a standard imaging setup, a standard setup using pulsed-mode fluoroscopy, and a reversed setup. The experiment was tested 5 times per setup, and the dosimeters’ values were recorded. Results The highest amount of radiation exposure occurred when obtaining an anteroposterior view of the spine in the standard setup. Compared with the standard setup, the pulsed-mode setting decreased the radiation exposure to the mannequin by a factor of 6 times (P < .001). Compared with the standard setup, the reversed setup also decreased the radiation exposure to the mannequin by a factor of 6 times (P < .001) and it had the lowest amount of radiation exposure to the eye level (P < .001). Conclusions Care should be taken when one is obtaining an anteroposterior view of the lumbar spine during lateral lumbar procedures to limit radiation exposure. Radiation exposure to the surgeon can be greatly minimized by using either a pulsed imaging mode or the reversed setup. The reversed setup has the lowest amount of radiation exposure to the eye level.

Tatsumi, Robert L.

2012-01-01

204

41 CFR 50-204.21 - Exposure of individuals to radiation in restricted areas.  

Code of Federal Regulations, 2012 CFR

... true Exposure of individuals to radiation in restricted areas. 50-204.21...STANDARDS FOR FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.21 Exposure of individuals to radiation in restricted areas. (a)...

2012-07-01

205

48 CFR 952.223-75 - Preservation of individual occupational radiation exposure records.  

...Preservation of individual occupational radiation exposure records. 952.223-75...Preservation of individual occupational radiation exposure records. Link to an amendment...planning and execution, or 952.223-72, Radiation protection and nuclear...

2014-10-01

206

Exposure of Treating Physician to Radiation during Pro-state Brachytherapy using Iodine-125 Seeds  

E-print Network

. Key Words: Prostate cancer, brachytherapy, Iodine-125 seeds, radiation expos- ure, TLD Short Title: Exposure to Radiation during Prostate Brachytherapy Kurztitel: Strahlenexposition bei der Brachytherapie1 Exposure of Treating Physician to Radiation during Pro- state Brachytherapy using Iodine-125

Krusche, Bernd

207

Radiation exposures and risks due to airtightening of homes in an alpine area with high radon emanation  

Microsoft Academic Search

Radon and its short-lived decay products in the indoor environment are the most important single source of exposure to ionizing radiation in Switzerland. Modifications in the construction of dwellings implemented to reduce energy consumption may change indoor pollutant levels and cause substantial long term hazards to the general public (1). The following estimate of additional exposure of humans to the

Werner Burkart; Christian Wernli; Hansheiri Brunner

1985-01-01

208

Radiation exposure to the orthopaedic surgeon during periacetabular osteotomy.  

PubMed

The objective of this study was to directly measure the radiation exposure to the orthopaedic surgeon and to measure dose points to the surgeon's fingers, thyroid gland, and forehead during intraoperative fluoroscopy in periacetabular osteotomy (PAO). In a series of 23 consecutive periacetabular osteotomy procedures, exposure monitoring was carried out using thermo luminescent dosimeters. The effective dose received by the operating surgeon was 0.008 mSv per operation which adds up to a yearly dose of 0.64 mSv from PAO. The median point equivalent dose (mSv) exposure under PAO was 0.009 for the forehead and thyroid gland, 0.045 for the right index finger, and 0.039 for the left index finger. The effective estimated yearly dose received by the operating surgeon was very low. Wearing a lead collar reduces radiation exposure to the thyroid gland while the lead gloves did not protect the surgeon's fingers. PMID:18958467

Mechlenburg, Inger; Daugaard, Henrik; Søballe, Kjeld

2009-12-01

209

Effects of fetal microwave radiation exposure on offspring behavior in mice.  

PubMed

The recent rapid development of electronic communication techniques is resulting in a marked increase in exposure of humans to electromagnetic fields (EMFs). This has raised public concerns about the health hazards of long-term environmental EMF exposure for fetuses and children. Some studies have suggested EMF exposure in children could induce nervous system disorders. However, gender-dependent effects of microwave radiation exposure on cognitive dysfunction have not previously been reported. Here we investigated whether in utero exposure to 9.417-GHz microwave throughout gestation (Days 3.5-18) affected behavior, using the open field test (OFT), elevated-plus maze (EPM), tail suspension test (TST), forced swimming test (FST) and Morris water maze (MWM). We found that mice showed less movement in the center of an open field (using the OFT) and in an open arm (using the EPM) after in utero exposure to 9.417-GHz radiation, which suggested that the mice had increased anxiety-related behavior. Mice demonstrated reduced immobility in TST and FST after in utero exposure to 9.417-GHz radiation, which suggested that the mice had decreased depression-related behavior. From the MWM test, we observed that male offspring demonstrated decreased learning and memory, while females were not affected in learning and memory, which suggested that microwaves had gender-dependent effects. In summary, we have provided the first experimental evidence of microwaves inducing gender-dependent effects. PMID:25359903

Zhang, Yanchun; Li, Zhihui; Gao, Yan; Zhang, Chenggang

2014-10-30

210

Review of retrospective dosimetry techniques for external ionising radiation exposures.  

PubMed

The current focus on networking and mutual assistance in the management of radiation accidents or incidents has demonstrated the importance of a joined-up approach in physical and biological dosimetry. To this end, the European Radiation Dosimetry Working Group 10 on 'Retrospective Dosimetry' has been set up by individuals from a wide range of disciplines across Europe. Here, established and emerging dosimetry methods are reviewed, which can be used immediately and retrospectively following external ionising radiation exposure. Endpoints and assays include dicentrics, translocations, premature chromosome condensation, micronuclei, somatic mutations, gene expression, electron paramagnetic resonance, thermoluminescence, optically stimulated luminescence, neutron activation, haematology, protein biomarkers and analytical dose reconstruction. Individual characteristics of these techniques, their limitations and potential for further development are reviewed, and their usefulness in specific exposure scenarios is discussed. Whilst no single technique fulfils the criteria of an ideal dosemeter, an integrated approach using multiple techniques tailored to the exposure scenario can cover most requirements. PMID:21183550

Ainsbury, E A; Bakhanova, E; Barquinero, J F; Brai, M; Chumak, V; Correcher, V; Darroudi, F; Fattibene, P; Gruel, G; Guclu, I; Horn, S; Jaworska, A; Kulka, U; Lindholm, C; Lloyd, D; Longo, A; Marrale, M; Monteiro Gil, O; Oestreicher, U; Pajic, J; Rakic, B; Romm, H; Trompier, F; Veronese, I; Voisin, P; Vral, A; Whitehouse, C A; Wieser, A; Woda, C; Wojcik, A; Rothkamm, K

2011-11-01

211

Ultraviolet radiation exposure in children: A review of measurement strategies  

Microsoft Academic Search

Rates of skin cancer in the U.S. are high and have been increasing rapidly. Recommendations for primary prevention focus on\\u000a the reduction of ultraviolet radiation (UVR) exposure, especially in childhood. Valid, reliable strategies are needed to measure\\u000a UVR exposure in children, to document baseline levels, and to assess intervention impact. This article reviews strategies\\u000a reported in observational and intervention studies

Lorri L. Creech; Joni A. Mayer

1997-01-01

212

Measurements of natural radionuclides in human teeth and animal bones as markers of radiation exposure from soil in the Northern Malaysian Peninsula  

NASA Astrophysics Data System (ADS)

This study aimed to estimate the radioactive accumulation of the radionuclides 40K, 137Cs, 210Pb, 226Ra, 228Ra, and 228Th in extracted human teeth, animal bones, and soil. The natural radionuclides were measured by high-purity germanium spectroscopy in extracted human teeth and animal bones from people and animals living in different states in the Northern Malaysian Peninsula. The average 40K, 137Cs, 210Pb, 226Ra, 228Ra, and 228Th concentrations in teeth were found to be 12.31±7.27 Bq g-1, 0.48±0.21 Bq g-1, 0.56±0.21 Bq g-1, 0.55±0.23 Bq g-1, 1.82±1.28 Bq g-1, and 0.50±0.14 Bq g-1, respectively. The corresponding concentrations in bones were found to be 3.79±0.81 Bq g-1, 0.07±0.02 Bq g-1, 0.08±0.02 Bq g-1, 0.16±0.04 Bq g-1, 0.51±1.08 Bq g-1, and 0.06±0.02 Bq g-1, respectively. The corresponding radionuclide concentrations in teeth from smokers were higher than those in non-smokers, and the corresponding radionuclide concentrations were higher in female teeth than in male teeth. The corresponding radionuclide concentrations were higher in teeth than in bones. A positive correlation was found between radionuclides in both teeth and bone samples.

Almayahi, B. A.; Tajuddin, A. A.; Jaafar, M. S.

2014-04-01

213

Radiation exposure and risk assessment for critical female body organs  

NASA Technical Reports Server (NTRS)

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

Atwell, William; Weyland, Mark D.; Hardy, Alva C.

1991-01-01

214

Cancer risks following diagnostic and therapeutic radiation exposure in children  

Microsoft Academic Search

The growing use of interventional and fluoroscopic imaging in children represents a tremendous benefit for the diagnosis and\\u000a treatment of benign conditions. Along with the increasing use and complexity of these procedures comes concern about the cancer\\u000a risk associated with ionizing radiation exposure to children. Children are considerably more sensitive to the carcinogenic\\u000a effects of ionizing radiation than adults, and

Ruth A. Kleinerman

2006-01-01

215

Ionizing radiation exposure of LDEF (pre-recovery estimates)  

NASA Technical Reports Server (NTRS)

The long duration exposure facility (LDEF), launched into a 258 nautical mile orbit with an inclination of 28.5 degrees, remained in space for nearly 6 yr. The 21,500 lb NASA satellite was one of the largest payloads ever deployed by the Space Shuttle. LDEF completed 32,422 orbits and carried 57 major experiments representing more than 200 investigators from 33 private companies, 21 universities and nine countries. The experiments covered a wide range of disciplines including basic science, electronics, optics, materials, structures and power and propulsion. A number of the experiments were specifically designed to measure the radiation environment. These experiments are of specific interest, since the LDEF orbit is essentially the same as that of the Space Station Freedom. Consequently, the radiation measurements on LDEF will play a significant role in the design of radiation shielding of the space station. The contributions of the various authors presented here attempt to predict the major aspects of the radiation exposure received by the various LDEF experiments and therefore should be helpful to investigators who are in the process of analyzing experiments which may have been affected by exposure to ionizing radiation. The paper discusses the various types and sources of ionizing radiation including cosmic rays, trapped particles (both protons and electrons) and secondary particles (including neutrons, spallation products and high-LET recoils), as well as doses and LET spectra as a function of shielding. Projections of the induced radioactivity of LDEF are also discussed.

Benton, E. V.; Heinrich, W.; Parnell, T. A.; Armstrong, T. W.; Derrickson, J. H.; Fishman, G. J.; Frank, A. L.; Watts, J. W. Jr; Wiegel, B.

1992-01-01

216

Radiation exposure induces inflammasome pathway activation in immune cells.  

PubMed

Radiation exposure induces cell and tissue damage, causing local and systemic inflammatory responses. Because the inflammasome pathway is triggered by cell death and danger-associated molecular patterns, we hypothesized that the inflammasome may signal acute and chronic immune responses to radiation. Using a mouse radiation model, we show that radiation induces a dose-dependent increase in inflammasome activation in macrophages, dendritic cells, NK cells, T cells, and B cells as judged by cleaved caspase-1 detection in cells. Time course analysis showed the appearance of cleaved caspase-1 in cells by day 1 and sustained expression until day 7 after radiation. Also, cells showing inflammasome activation coexpressed the cell surface apoptosis marker annexin V. The role of caspase-1 as a trigger for hematopoietic cell losses after radiation was studied in caspase-1(-/-) mice. We found less radiation-induced cell apoptosis and immune cell loss in caspase-1(-/-) mice than in control mice. Next, we tested whether uric acid might mediate inflammasome activation in cells by treating mice with allopurinol and discovered that allopurinol treatment completely blocked caspase-1 activation in cells. Finally, we demonstrate that radiation-induced caspase-1 activation occurs by a Nod-like receptor family protein 3-independent mechanism because radiation-exposed Nlrp3(-/-) mice showed caspase-1 activation profiles that were indistinguishable from those of wild-type mice. In summary, our data demonstrate that inflammasome activation occurs in many immune cell types following radiation exposure and that allopurinol prevented radiation-induced inflammasome activation. These results suggest that targeting the inflammasome may help control radiation-induced inflammation. PMID:25539818

Stoecklein, Veit M; Osuka, Akinori; Ishikawa, Shizu; Lederer, Madeline R; Wanke-Jellinek, Lorenz; Lederer, James A

2015-02-01

217

Radiation exposure of U.S. military individuals.  

PubMed

The U.S. military consists of five armed services: the Army, Navy, Marine Corps, Air Force, and Coast Guard. It directly employs 1.4 million active duty military, 1.3 million National Guard and reserve military, and 700,000 civilian individuals. This paper describes the military guidance used to preserve and maintain the health of military personnel while they accomplish necessary and purposeful work in areas where they are exposed to radiation. It also discusses military exposure cohorts and associated radiogenic disease compensation programs administered by the U.S. Department of Veterans Affairs, the U.S. Department of Justice, and the U.S. Department of Labor. With a few exceptions, the U.S. military has effectively employed ionizing radiation since it was first introduced during the Spanish-American War in 1898. The U.S military annually monitors 70,000 individuals for occupational radiation exposure: ~2% of its workforce. In recent years, the Departments of the Navy (including the Marine Corps), the Army, and the Air Force all have a low collective dose that remains close to 1 person-Sv annually. Only a few Coast Guard individuals are now routinely monitored for radiation exposure. As with the nuclear industry as a whole, the Naval Reactors program has a higher collective dose than the remainder of the U.S. military. The U.S. military maintains occupational radiation exposure records on over two million individuals from 1945 through the present. These records are controlled in accordance with the Privacy Act of 1974 but are available to affected individuals or their designees and other groups performing sanctioned epidemiology studies.Introduction of Radiation Exposure of U.S. Military Individuals (Video 2:19, http://links.lww.com/HP/A30). PMID:24378502

Blake, Paul K; Komp, Gregory R

2014-02-01

218

Proteomic Analysis of Low Dose Arsenic and Ionizing Radiation Exposure on Keratinocytes  

PubMed Central

Human exposure to arsenic and ionizing radiation occur environmentally at low levels. While the human health effects of arsenic and ionizing radiation have been examined separately, there is little information regarding their combined effects at doses approaching environmental levels. Arsenic toxicity may be affected by concurrent ionizing radiation especially given their known individual carcinogenic actions at higher doses. We found that keratinocytes responded to either low dose arsenic and/or low dose ionizing radiation exposure, resulting in differential proteomic expression based on 2DGE, immunoblotting and statistical analysis. Seven proteins were identified that passed a rigorous statistical screen for differential expression in 2DGE and also passed a strict statistical screen for follow-up immunoblotting. These included: ?-enolase, epidermal-fatty acid binding protein, heat shock protein 27, histidine triad nucleotide-binding protein 1, lactate dehydrogenase A, protein disulfide isomerase precursor and S100A9. Four proteins had combined effects that were different than would be expected based on the response to either individual toxicant. These data demonstrate a possible reaction to the combined insult that is substantially different from that of either separate treatment. Several proteins had different responses than what has been seen from high dose exposures, adding to the growing literature suggesting that the cellular responses to low dose exposures are distinct. PMID:19294697

Berglund, Susanne R.; Santana, Alison R.; Li, Dan; Rice, Robert H.; Rocke, David M.; Goldberg, Zelanna

2008-01-01

219

Preventable Exposures Associated With Human Cancers  

PubMed Central

Information on the causes of cancer at specific sites is important to cancer control planners, cancer researchers, cancer patients, and the general public. The International Agency for Research on Cancer (IARC) Monograph series, which has classified human carcinogens for more than 40 years, recently completed a review to provide up-to-date information on the cancer sites associated with more than 100 carcinogenic agents. Based on IARC’s review, we listed the cancer sites associated with each agent and then rearranged this information to list the known and suspected causes of cancer at each site. We also summarized the rationale for classifications that were based on mechanistic data. This information, based on the forthcoming IARC Monographs Volume 100, offers insights into the current state-of-the-science of carcinogen identification. Use of mechanistic data to identify carcinogens is increasing, and epidemiological research is identifying additional carcinogens and cancer sites or confirming carcinogenic potential under conditions of lower exposure. Nevertheless, some common human cancers still have few (or no) identified causal agents. PMID:22158127

Baan, Robert; Straif, Kurt; Grosse, Yann; Lauby-Secretan, Béatrice; El Ghissassi, Fatiha; Bouvard, Véronique; Benbrahim-Tallaa, Lamia; Guha, Neela; Freeman, Crystal; Galichet, Laurent; Wild, Christopher P.

2011-01-01

220

Mesenchymal Stem Cells Retain Their Defining Stem Cell Characteristics After Exposure to Ionizing Radiation  

SciTech Connect

Purpose: Mesenchymal stem cells (MSCs) have the ability to migrate to lesion sites and undergo differentiation into functional tissues. Although this function may be important for tissue regeneration after radiation therapy, the influence of ionizing radiation (IR) on cellular survival and the functional aspects of differentiation and stem cell characteristics of MSCs have remained largely unknown. Methods and Materials: Radiation sensitivity of human primary MSCs from healthy volunteers and primary human fibroblast cells was examined, and cellular morphology, cell cycle effects, apoptosis, and differentiation potential after exposure to IR were assessed. Stem cell gene expression patterns after exposure to IR were studied using gene arrays. Results: MSCs were not more radiosensitive than human primary fibroblasts, whereas there were considerable differences regarding radiation sensitivity within individual MSCs. Cellular morphology, cytoskeletal architecture, and cell motility were not markedly altered by IR. Even after high radiation doses up to 10 Gy, MSCs maintained their differentiation potential. Compared to primary fibroblast cells, MSCs did not show an increase in irradiation-induced apoptosis. Gene expression analyses revealed an upregulation of various genes involved in DNA damage response and DNA repair, but expression of established MSC surface markers appeared only marginally influenced by IR. Conclusions: These data suggest that human MSCs are not more radiosensitive than differentiated primary fibroblasts. In addition, upon photon irradiation, MSCs were able to retain their defining stem cell characteristics both on a functional level and regarding stem cell marker expression.

Nicolay, Nils H., E-mail: n.nicolay@dkfz.de [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Sommer, Eva; Lopez, Ramon; Wirkner, Ute [Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Trinh, Thuy [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Sisombath, Sonevisay [Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany); Debus, Jürgen [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Ho, Anthony D.; Saffrich, Rainer [Department of Hematology and Oncology, Heidelberg University Hospital, Heidelberg (Germany); Huber, Peter E. [Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg (Germany); Department of Molecular and Radiation Oncology, German Cancer Research Center, Heidelberg (Germany)

2013-12-01

221

AIRCREW EXPOSURE FROM COSMIC RADIATION ON COMMERCIAL AIRLINE ROUTES  

Microsoft Academic Search

As a result of the recent recommendations of the ICRP 60, and in anticipation of possible regulation on occupational exposure of Canadian-based aircrew, an extensive study was carried out by the Royal Military College of Canada over a one- year period to measure the cosmic radiation at commercial jet altitudes. A tissue-equivalent proportional counter was used to measure the ambient

B. J. Lewis; M. J. McCall; A. R. Green; L. G. I. Bennett; M. Pierre; U. J. Schrewe; K. O'Brien; E. Felsberger

222

THE CLINICAL MANAGEMENT OF RADIATION EXPOSURE DUE TO ATOMIC EXPLOSIONS  

Microsoft Academic Search

The recommended treatment for radiation exposure to atomic explosions is ; principally symptomatic and fundamentally based on the presenting picture. The ; therapeutic program should include: complete physical and mental rest with mild ; sedation, a bland, low-residue, high-protein diet, and general nursing measures, ; including skin care and oral hygiene to avoid ulcerations. Early shocklike ; syndromes with prostration,

1961-01-01

223

Final Report of the Radiation Exposure Compensation Act Committee  

NSDL National Science Digital Library

This is the final report of the Radiation Exposure Compensation Act (RECA) Committee published in July 1996. This report makes recommendations about policy issues relating to compensation for uranium workers with lung cancer and nonmalignant respiratory diseases. This report also includes an appendix that addresses the establishment of data-based criteria for radon-associated lung cancer.

Energy, Department O.

224

Medical management of three workers following a radiation exposure incident  

SciTech Connect

The medical management of three individuals involved in an exposure incident to whole-body radiation at a nuclear generating plant of a Canadian electrical utility is described. The exposure incident resulted in the two highest whole-body radiation doses ever received in a single event by workers in a Canadian nuclear power plant. The individual whole-body doses (127.4 mSv, 92.0 mSv, 22.4 mSv) were below the threshold for acute radiation sickness but the exposures still presented medical management problems related to assessment and counseling. Serial blood counting and lymphocyte cytogenetic analysis to corroborate the physical dosimetry were performed. All three employees experienced somatic symptoms due to stress and one employee developed post-traumatic stress disorder. This incident indicates that there is a need in such radiation exposure accidents for early and continued counseling of exposed employees to minimize the risk of development of stress-related symptoms.

House, R.A.; Sax, S.E.; Rumack, E.R.; Holness, D.L. (Department of Occupational and Environmental Health, St. Michael's Hospital, Toronto, Ontario (Canada))

1992-01-01

225

Radiation Exposure Alters Expression of Metabolic Enzyme Genes in Mice  

NASA Technical Reports Server (NTRS)

Most administered pharmaceuticals are metabolized by the liver. The health of the liver, especially the rate of its metabolic enzymes, determines the concentration of circulating drugs as well as the duration of their efficacy. Most pharmaceuticals are metabolized by the liver, and clinically-used medication doses are given with normal liver function in mind. A drug overdose can result in the case of a liver that is damaged and removing pharmaceuticals from the circulation at a rate slower than normal. Alternatively, if liver function is elevated and removing drugs from the system more quickly than usual, it would be as if too little drug had been given for effective treatment. Because of the importance of the liver in drug metabolism, we want to understand the effects of spaceflight on the enzymes of the liver and exposure to cosmic radiation is one aspect of spaceflight that can be modeled in ground experiments. Additionally, it has been previous noted that pre-exposure to small radiation doses seems to confer protection against later and larger radiation doses. This protective power of pre-exposure has been called a priming effect or radioadaptation. This study is an effort to examine the drug metabolizing effects of radioadaptation mechanisms that may be triggered by early exposure to low radiation doses.

Wotring, V. E.; Mangala, L. S.; Zhang, Y.; Wu, H.

2011-01-01

226

Health Effects of Exposure to Low-Level Ionizing Radiation  

Microsoft Academic Search

This book comprises chapters contributed, with one exception, by American scientists and physicians and inevitably it is very much biased towards the American scene. Even so, the rest of us can draw parallel with our own societies. The book is aimed towards a medical audience and those in the radiation protection business, whose professional lives revolve around low level exposures,

David Lloyd

1997-01-01

227

Cosmic radiation exposure in subsonic air transport  

NASA Technical Reports Server (NTRS)

Data derived from 1973 statistics on 2.99 million intercity flights carrying 468 million seats were included in the calculations, yielding a total of 581 billion seat-kilometer. The average flight was 1,084 km in length, was flown at an altitude of 9.47 km, and lasted 1.41 h. The average dose rate was 0.20 mrem/h, resulting in an average passenger dose of 2.82 mrem/year and an average crewmember dose of 160 mrem/year. The average radiation dose to the total U.S. population was 0.47 mrem/person/year. These results are in good agreement with data from several experiments performed by us and others in aircraft at various altitudes and latitudes. The significance of these doses to the population is discussed.

Wallace, R. W.; Sondhaus, C. A.

1978-01-01

228

Prediction of aircrew radiation exposure during solar particle events  

NASA Astrophysics Data System (ADS)

A transport code analysis using the Monte Carlo code MCNPX is used to propagate an extrapolated particle spectrum based on GOES satellite measurements through the atmosphere to estimate aircrew radiation exposure for solar particle events. Comparison between code predictions and actual flight measurements made during ground level event (GLE) 60 and 65 are presented. Data from ground-level neutron monitoring stations around the world are also compared against the model predictions for various events. A computer code has been further developed implementing this methodology for routine aircrew exposure estimation from solar particle events to supplement those predictions from galactic cosmic radiation using the PCAIRE code in order to better determine the overall aircrew exposure at altitude.

Bennett, Les

229

Effects upon health of occupational exposure to microwave radiation (radar)  

SciTech Connect

The effects of occupational experience with microwave radiation (radar) on the health of US enlisted Naval personnel were studied in cohorts of approximately 20,000 men with maximum opportunity for exposure (electronic equipment repair) and 20,000 with minimum potential for exposure (equipment operation) who served during the Korean War period. Potential exposure was assessed in terms of occupational duties, length of time in occupation and power of equipment at the time of exposure. Actual exposure to members of each cohort could not be established. Mortality by cause of death, hospitalization during military service, later hospitalization in Veterans Administration (VA) facilities, and VA disability compensation were the health indexes studied, largely through the use of automated record systems. No adverse effects were detected in these indexes that could be attributed to potential microwave radiation exposures during the period 1950-1954. Functional and behavioral changes and ill-defined conditions, such as have been reported as microwave effects, could not be investigated in this study but subgroups of the living study population can be identified for expanded follow-up.

Robinette, C.D. (National Academy of Sciences-National Research Council, Washington, DC); Silverman, C.; Jablon, S.

1980-07-01

230

Cumulative effects from repeated exposures to ultraviolet radiation  

SciTech Connect

Repeated exposures to subliminal doses of UVR, given at 24-hr intervals, resulted in a lowering of the erythema threshold dose. At erythemogenically equivalent doses, UV-A was the most effective and UV-C the least. A similar and more pronounced effect was observed following repeated exposures to subthreshold doses of UV-A and topically applied 8-methoxypsoralen. These findings provide quantitative evidence for the cumulative nature of acute UVR damage in human skin.

Kaidbey, K.H.; Kligman, A.M.

1981-05-01

231

Radiation exposure to the surgeon during closed interlocking intramedullary nailing  

SciTech Connect

During interlocking intramedullary nailing of twenty-five femoral and five tibial fractures, the primary surgeon wore both a universal film badge on the collar of the lead apron and a thermoluminescent dosimeter ring on the dominant hand to quantify the radiation that he or she received. When distal interlocking was performed, the first ring was removed and a second ring was used so that a separate recording could be made for this portion of the procedure. At the conclusion of the study, all of the recorded doses of radiation were averaged. The average amount of radiation to the head and neck during the entire procedure was 7.0 millirems of deep exposure and 8.0 millirems of shallow exposure. The average dose of radiation to the dominant hand during insertion of the intramedullary nail and the proximal interlocking screw was 13.0 millirems, while the average amount during insertion of the distal interlocking nail was 12.0 millirems. Both of these averages are well within the government guidelines for allowable exposure to radiation during one-quarter (three months) of a year. Precautions that are to be observed during this procedure are recommended.

Levin, P.E.; Schoen, R.W. Jr.; Browner, B.D.

1987-06-01

232

Radiation exposure of aviation crewmembers and cancer.  

PubMed

Crewmembers are exposed to galactic cosmic radiation on every flight and occasionally to solar protons on polar flights. Data are presented showing that the proton occasions are seven times more frequent than generally believed. Crewmembers are also exposed to neutrons and gamma rays from the sun and to gamma rays from terrestrial thunderstorms. Solar neutrons and gamma rays (1) expose the daylight side of Earth, (2) are most intense at lower latitudes, (3) may be as or more frequent than solar protons, and (4) have relativistic energies. The U.S. agency responsible for crewmember safety only considers the galactic component with respect to its recommended 20 mSv y limit, but it has an estimate for a thunderstorm dose of 30 mSv. In view of overlooked sources, possible over-limit doses, and lack of dosimetry, dose reconstructions are needed. However, using the agency dose estimates and the compensation procedure for U.S. nuclear weapon workers, the probability of crewmember cancers can be at least as likely as not. Ways to improve the quality of dose estimates are suggested, and a worker's compensation program specific to aviation crewmembers is recommended. PMID:25437523

Bramlitt, Edward T; Shonka, Joseph J

2015-01-01

233

Human exposure assessment for airborne pollutants: Advances and opportunities  

SciTech Connect

The material presented in this book originated in an information-gathering workshop hosted by the John B. Pierce Laboratory, Yale University, October 1988. The workshop was convened at the behest of the National Research Council to address the significant health efects caused by exposure to air pollutants. The committee was to evaluate techniques to assess human exposure to these toxins. The book examines exposure assessment in relation to both indoor and outdoor pollutants. Information is provided in the areas of principles of exposure assessment, the framework for assessing exposures, sampling and physical-chemical measuremnts, biological markers in assessing exposure, survey research methods, models, and current and anticipated applications.

Not Available

1991-01-01

234

Human Genetic Marker for Resistance to Radiation and Chemicals  

SciTech Connect

TO characterize the human HRDAD9 gene and evaluate its potential as a biomarker to predict susceptibility to the deleterious health effects potentially caused by exposure to radiations or chemicals present at DOE hazardous waste cleanup sites. HRAD9 is a human gene that is highly conserved throughout evolution. Related genes have been isolated from yeasts and mice, underscoring its biological significance. Most of our previous work involved characterization of the yeast gene cognate, wherein it was determined that the corresponding protein plays a significant role in promoting resistance of cells to radiations and chemicals, and in particular, controlling cell growth in response to DNA damage.

DR. Howard B. Lieberman

2001-05-11

235

Cataract after repeated daily in vivo exposure to ultraviolet radiation.  

PubMed

Epidemiological data indicate a correlation between lifelong exposure to ultraviolet radiation and cortical cataract. However, there is no quantitative experimental data on the effect of daily repeated in vivo exposures of the eye to UVR. Therefore, this experiment was designed to verify whether the dose additivity for UVR exposures holds through periods of time up to 30 d. Eighty rats were conditioned to a rat restrainer 5 d prior to exposure. All animals were divided into four exposure period groups of 1, 3, 10, and 30 d of exposure to UVR. Each exposure period group of 20 animals was randomly divided into five cumulated UVR dose subgroups. Eighteen-wk-old non-anesthetized albino Sprague-Dawley rats were exposed daily to UVR-300 nm for 15 min. One week after the last exposure, animals were sacrificed. The lenses were extracted for macroscopic imaging of dark-field anatomy, and degree of cataract was quantified by measurement of the intensity of forward lens light scattering. Maximum tolerable dose (MTD(2.3:16)), a statistically defined standard for sensitivity for the threshold for UVR cataract, was estimated for each exposure period. Exposed lenses developed cataract with varying appearance on the anterior surface. Single low doses of UVR accumulated to cause cataract during periods up to 30 d. MTD(2.3:16) for 1, 3, 10, and 30 d of repeated exposures was estimated to 4.70, 4.74, 4.80, and 6.00 kJ m(-2), respectively. In conclusion, the lens sensitivity to UVR-B for 18-wk-old Sprague-Dawley rats decreases with the increasing number of days being exposed. PMID:25353237

Galichanin, Konstantin; Löfgren, Stefan; Söderberg, Per

2014-12-01

236

Stem cell responses after radiation exposure: A key to the evaluation and prediction of its effects  

SciTech Connect

A biomathematical model of granulocytopoiesis is described and used to analyze the blood granulocyte changes seen in the blood of dogs and humans after continuous and after acute external radiation exposure. This allows to relate the cell change pattern seen to the extent of stem cell damage in the hematopoietic bone marrow distributed as semiautonomous units throughout the skeletal bones. The model is described briefly and consists of 8 cellular and 2 regulatory compartments and is described by 37 differential equations. With the help of this model, it can be shown that the chronic radiation exposure of dogs at a rate of between 0.003 and 0.12 Gy per day results in a system failure with subsequent death of the animal, if the stem cell pool decreases below 2.5% of its normal content. In human beings exposed to a single radiation exposure (as seen in radiation accidents) the simulation of the granulocyte pattern results in the finding that a reduction of the stem pool to 5-10% of normal is compatible with the assumption of its {open_quotes}reversible{close_quotes} damage (to be treated by conventional replacement therapy including cytokines), whereas the reduction of blood granulocytes to levels of less than 200-300 per mm{sup 3} on day 5-6 after exposure indicates that no stem cells remain from which a spontaneous regeneration could occur and hence would require a substitution therapy by stem cell transplantation. The same model was used to correlate the changing granulocyte pattern seen after autologous blood stem cell transfusion in patients treated with supralethal radiochemo conditioning regimen. The results indicate a proportionality of progenitor cells in the transfusate with the calculated stem cell number of the modeling exercise. It is proposed to use the pattern of granulocyte changes in the blood as a principal indicator to predict the outcome of a radiation exposure and to select appropriate therapeutic strategies. 29 refs., 7 figs., 2 tabs.

Fliedner, T.M.; Paul, W.; Tibken, B.; Hofer, E.P. [Univ. of Ulm (Germany)

1996-06-01

237

Mitigation Strategies for Acute Radiation Exposure during Space Flight  

NASA Technical Reports Server (NTRS)

While there are many potential risks in a Moon or Mars mission, one of the most important and unpredictable is that of crew radiation exposure. The two forms of radiation that impact a mission far from the protective environment of low-earth orbit, are solar particle events (SPE) and galactic cosmic radiation (GCR). The effects of GCR occur as a long-term cumulative dose that results increased longer-term medical risks such as malignancy and neurological degeneration. Unfortunately, relatively little has been published on the medical management of an acute SPE that could potentially endanger the mission and harm the crew. Reanalysis of the largest SPE in August 1972 revealed that the dose rate was significantly higher than previously stated in the literature. The peak dose rate was 9 cGy h(sup -1) which exceeds the low-dose-rate criteria for 25 hrs (National Council on Radiation Protection) and 16 hrs (United Nations Scientific Committee on the Effects of Atomic Radiation). The bone marrow dose accumulated was 0.8 Gy, which exceeded the 25 and 16 hour criteria and would pose a serious medical risk. Current spacesuits would not provide shielding from the damaging effects for an SPE as large as the 1972 event, as increased shielding from 1-5 gm/cm(sup 2) would do little to shield the bone marrow from exposure. Medical management options for an acute radiation event are discussed based on recommendations from the Department of Homeland Security, Centers for Disease Control and evidence-based scientific literature. The discussion will also consider how to define acute exposure radiation safety limits with respect to exploration-class missions, and to determine the level of care necessary for a crew that may be exposed to an SPE similar to August 1972.

Hamilton, Douglas R.; Epelman, Slava

2006-01-01

238

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

Microsoft Academic Search

In order to develop a framework for the assessment of the environmental impact of radiation, it is necessary to establish the relationship between exposure (dose rate, accumulated dose) and the effects that may be induced in plants and animals. With this purpose in mind, the data available on effects induced by ionising radiation in various wildlife groups have been reviewed

A. Real; S. Sundell-Bergman; J. F. Knowles; D. S. Woodhead; I. Zinger

2004-01-01

239

Astronaut Exposures to Ionizing Radiation in a Lightly-Shielded Spacesuit  

NASA Technical Reports Server (NTRS)

The normal working and living areas of the astronauts are designed to provide an acceptable level of protection against the hazards of ionizing radiation of the space environment. Still there are occasions when they must don a spacesuit designed mainly for environmental control and mobility and leave the confines of their better-protected domain. This is especially true for deep space exploration. The impact of spacesuit construction on the exposure of critical astronaut organs will be examined in the ionizing radiation environments of free space, the lunar surface and the Martian surface. The computerized anatomical male model is used to evaluate astronaut self-shielding factors and to determine space radiation exposures to critical radiosensitive human organs.

Wilson, J. W.; Simonsen, L. C.; Shinn, J. L.; Kim, M.-H. Y.; Cucinotta, F. A.; Badavi, F. F.; Atwell, W.

1999-01-01

240

Cell phone radiation exposure on brain and associated biological systems.  

PubMed

Wireless technologies are ubiquitous today and the mobile phones are one of the prodigious output of this technology. Although the familiarization and dependency of mobile phones is growing at an alarming pace, the biological effects due to the exposure of radiations have become a subject of intense debate. The present evidence on mobile phone radiation exposure is based on scientific research and public policy initiative to give an overview of what is known of biological effects that occur at radiofrequency (RF)/ electromagnetic fields (EMFs) exposure. The conflict in conclusions is mainly because of difficulty in controlling the affecting parameters. Biological effects are dependent not only on the distance and size of the object (with respect to the object) but also on the environmental parameters. Health endpoints reported to be associated with RF include childhood leukemia, brain tumors, genotoxic effects, neurological effects and neurodegenerative diseases, immune system deregulation, allergic and inflammatory responses, infertility and some cardiovascular effects. Most of the reports conclude a reasonable suspicion of mobile phone risk that exists based on clear evidence of bio-effects which with prolonged exposures may reasonably be presumed to result in health impacts. The present study summarizes the public issue based on mobile phone radiation exposure and their biological effects. This review concludes that the regular and long term use of microwave devices (mobile phone, microwave oven) at domestic level can have negative impact upon biological system especially on brain. It also suggests that increased reactive oxygen species (ROS) play an important role by enhancing the effect of microwave radiations which may cause neurodegenerative diseases. PMID:23678539

Kesari, Kavindra Kumar; Siddiqui, Mohd Haris; Meena, Ramovatar; Verma, H N; Kumar, Shivendra

2013-03-01

241

Effects of millimeter-wave electromagnetic exposure on the morphology and function of human cryopreserved spermatozoa.  

PubMed

Exposure of human cryopreserved spermatozoa to millimeter-wave electromagnetic radiation of 0.03 mW/cm2 density for 5 min in normozoospermia and for 15 min in asthenozoospermia lead to increase of the fraction of mobile spermatozoa without impairing the membrane integrity and nuclear chromatin status and without apoptosis generation. PMID:25257416

Volkova, N A; Pavlovich, E V; Gapon, A A; Nikolov, O T

2014-09-01

242

Changes in Liver Metabolic Gene Expression from Radiation Exposure  

NASA Technical Reports Server (NTRS)

Increased exposure to radiation is one physiological stressor associated with spaceflight. While known to alter normal physiological function, how radiation affects metabolism of administered medications is unclear. Crew health could be affected if the actions of medications used in spaceflight deviated from expectations formed during terrestrial medication use. Three different doses of gamma radiation (50 mGy - 6.05 Gy) and a sham were administered to groups of 6 mice each, and after various intervals of recovery time, liver gene expression was measured with RT-qPCR arrays for drug metabolism and DNA repair enzymes. Results indicated approx.65 genes of the 190 tested were significantly affected by at least one of the radiation doses. Many of the affected genes are involved in the metabolism of drugs with hydrophobic or steroid-like structures, maintenance of redox homeostasis and repair of DNA damage. Most affected genes returned to near control expression levels by 7 days post-treatment. With 6 Gy exposure, metallothionein expression was 132-fold more than control at the 4 hr time point, and fell at each later time point (11-fold at 24 hrs, and 8-fold at 7 days). In contrast, Cyp17a1 showed a 4-fold elevation at 4 hrs after exposure and remained constant for 7 days.

Peters, C. P.; Wotring, V. E.

2012-01-01

243

Overview of DOE Radiation Exposure Information Reporting System (REIRS)  

SciTech Connect

The purpose of the study is to determine the adequacy of the present system, identify any necessary short-term improvements and propose feasible alternatives for an improved system. The study includes topical reports as follows: current Personnel Dosimetry Practices at DOE Facilities; overview of DOE Radiation Exposure Information Reporting System (REIRS); and alternatives to Provide Upgraded Occupational Exposure Record System. This study constitutes the second report and was a joint effort between Battelle Northwest and EG and G, Idaho Falls. EG and G has been responsible for the respository since the fall of 1978.

Fix, J.J.; Briscoe, G.J.; Selby, J.M.; Vallario, E.J.

1981-05-01

244

Out-of-Field Cell Survival Following Exposure to Intensity-Modulated Radiation Fields  

Microsoft Academic Search

Purpose: To determine the in-field and out-of-field cell survival of cells irradiated with either primary field or scattered radiation in the presence and absence of intercellular communication. Methods and Materials: Cell survival was determined by clonogenic assay in human prostate cancer (DU145) and primary fibroblast (AGO1552) cells following exposure to different field configurations delivered using a 6-MV photon beam produced

Karl T. Butterworth; Conor K. McGarry; Colman Trainor; Joe M. O’Sullivan; Alan R. Hounsell; Kevin M. Prise

2011-01-01

245

Quantification of low-level radiation exposure by conventional chromosome aberration analysis  

Microsoft Academic Search

Chromosome dosimetry, in its conventional form largely based on scoring of dicentrics and ring chromosomes in human blood lymphocytes, is the most widely distributed and reliable biological technique in radiological protection to estimate individual whole-body doses of about 100 mGy of low-LET radiation. Attempts to detect and quantify effects even of lower acute doses or protracted and chronic exposures have

Manfred Bauchinger

1995-01-01

246

Full Mission Astronaut Radiation Exposure Assessments for Long Duration Lunar Surface Missions  

NASA Technical Reports Server (NTRS)

Risk to astronauts due to ionizing radiation exposure is a primary concern for missions beyond Low Earth Orbit (LEO) and will drive mission architecture requirements, mission timelines, and operational practices. Both galactic cosmic ray (GCR) and solar particle event (SPE) environments pose a risk to astronauts for missions beyond LEO. The GCR environment, which is made up of protons and heavier ions covering a broad energy spectrum, is ever present but varies in intensity with the solar cycle, while SPEs are sporadic events, consisting primarily of protons moving outward through the solar system from the sun. The GCR environment is more penetrating and is more difficult to shield than SPE environments, but lacks the intensity to induce acute effects. Large SPEs are rare, but they could result in a lethal dose, if adequate shielding is not provided. For short missions, radiation risk is dominated by the possibility of a large SPE. Longer missions also require planning for large SPEs; adequate shielding must be provided and operational constraints must allow astronauts to move quickly to shielded locations. The dominant risk for longer missions, however, is GCR exposure, which accumulates over time and can lead to late effects such as cancer. SPE exposure, even low level SPE exposure received in heavily shielded locations, will increase this risk. In addition to GCR and SPE environments, the lunar neutron albedo resulting mainly from the interaction of GCRs with regolith will also contribute to astronaut risk. Full mission exposure assessments were performed for proposed long duration lunar surface mission scenarios. In order to accomplish these assessments, radiation shielding models were developed for a proposed lunar habitat and rover. End-to-End mission exposure assessments were performed by first calculating exposure rates for locations in the habitat, rover, and during extra-vehicular activities (EVA). Subsequently, total mission exposures were evaluated for proposed timelines. A number of computational tools and mathematical models, which have been incorporated into NASA's On-Line Tool for the Assessment of Radiation In Space (OLTARIS), were used for this study. These tools include GCR and SPE environment models, human body models, and the HZETRN space radiation transport code, which is used to calculate the transport of the charged particles and neutrons through shielding materials and human tissue. Mission exposure results, assessed in terms of effective dose, are presented for proposed timelines and recommendations are made for improved astronaut shielding and safer operational practice.

Adamczyk, Anne M.; Clowdsley, Martha S.; Qualls, Garry D.; Blattnig, Steve B.; Lee, Kerry T.; Fry, Dan J.; Stoffle, Nicholas N.; Simonsen, Lisa C.; Slaba, Tony C.; Walker, Steven A.; Zapp, Edward N.

2010-01-01

247

High Dietary Iron and Radiation Exposure Increase Biomarkers of Oxidative Stress in Blood and Liver of Rats  

NASA Technical Reports Server (NTRS)

Radiation exposure and increased iron (Fe) status independently cause oxidative damage that can result in protein, lipid, and DNA oxidation. During space flight astronauts are exposed to both increased radiation and increased Fe stores. Increased body Fe results from a decrease in red blood cell mass and the typically high Fe content of the food system. In this study we investigated the combined effects of radiation exposure (0.375 Gy of Cs-137 every other day for 16 days for a total of 3 Gy) and high dietary Fe (650 mg Fe/kg diet compared to 45 mg Fe/kg for controls) in Sprague-Dawley rats (n=8/group). Liver and serum Fe were significantly increased in the high dietary Fe groups. Likewise, radiation treatment increased serum ferritin and Fe concentrations. These data indicate that total body Fe stores increase with both radiation exposure and excess dietary Fe. Hematocrit decreased in the group exposed to radiation, providing a possible mechanism for the shift in Fe indices after radiation exposure. Markers of oxidative stress were also affected by both radiation and high dietary Fe, evidenced by increased liver glutathione peroxidase (GPX) and serum catalase as well as decreased serum GPX. We thus found preliminary indications of synergistic effects of radiation exposure and increased dietary Fe, warranting further study. This study was funded by the NASA Human Research Project.

Morgan, Jennifer L. L.; Theriot, Corey A.; Wu, Honglu; Smith, Scott M.; Zwart, Sara R.

2012-01-01

248

Personalized Exposure Assessment: Promising Approaches for Human Environmental Health Research  

PubMed Central

New technologies and methods for assessing human exposure to chemicals, dietary and lifestyle factors, infectious agents, and other stressors provide an opportunity to extend the range of human health investigations and advance our understanding of the relationship between environmental exposure and disease. An ad hoc Committee on Environmental Exposure Technology Development was convened to identify new technologies and methods for deriving personalized exposure measurements for application to environmental health studies. The committee identified a “toolbox” of methods for measuring external (environmental) and internal (biologic) exposure and assessing human behaviors that influence the likelihood of exposure to environmental agents. The methods use environmental sensors, geographic information systems, biologic sensors, toxicogenomics, and body burden (biologic) measurements. We discuss each of the methods in relation to current use in human health research; specific gaps in the development, validation, and application of the methods are highlighted. We also present a conceptual framework for moving these technologies into use and acceptance by the scientific community. The framework focuses on understanding complex human diseases using an integrated approach to exposure assessment to define particular exposure–disease relationships and the interaction of genetic and environmental factors in disease occurrence. Improved methods for exposure assessment will result in better means of monitoring and targeting intervention and prevention programs. PMID:16002370

Weis, Brenda K.; Balshaw, David; Barr, John R.; Brown, David; Ellisman, Mark; Lioy, Paul; Omenn, Gilbert; Potter, John D.; Smith, Martyn T.; Sohn, Lydia; Suk, William A.; Sumner, Susan; Swenberg, James; Walt, David R.; Watkins, Simon; Thompson, Claudia; Wilson, Samuel H.

2005-01-01

249

Risk of leukemia in Seascale from radiation exposure  

SciTech Connect

An excess of leukemias in children has been observed between 1950 and 1980 in the village of Seascale (population about 3,000) which is situated approximately 3 km to the south of Sellafield nuclear fuel reprocessing plant in West Cumbria, England. Radiation doses from all the main sources of radiation exposure of the population and risks of radiation-induced leukemia have been calculated for children born and living in Seascale during the period of operation of the plant. For the Seascale study population of 1225 children and young persons, followed to age 20 y, or followed until 1980 for those born after 1960, 0.016 radiation-induced leukemias are predicted from the Sellafield discharges. This corresponds to an average risk to children in the population of about one in 75,000. For the four fatal leukemias observed in the study population (0.5 expected from United Kingdom statistics) to be attributed to the operations at Sellafield, the average risk would have to be increased by a factor of about 250, to one in 300. Although there is some uncertainty about the releases from the plant and concentrations of radionuclides in environmental materials in the Sellafield area, particularly for the early years of its operation, the possibility that the doses calculated and the risk coefficients used for radiation-induced leukemia could be so substantially wrong is very unlikely. The number of radiation-induced leukemias from all radiation sources is calculated to be 0.1, which corresponds to a risk of about one in 12,250 for the average child in the study population. About two-thirds of the risk is from natural radiation, 16% from the Sellafield discharges, and nuclear weapons fallout and medical exposure each contribute about 9%.

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

1988-08-01

250

Management of cosmic radiation exposure for aircraft crew in Japan.  

PubMed

The International Commission on Radiological Protection has recommended that cosmic radiation exposure of crew in commercial jet aircraft be considered as occupational exposure. In Japan, the Radiation Council of the government has established a guideline that requests domestic airlines to voluntarily keep the effective dose of cosmic radiation for aircraft crew below 5 mSv y(-1). The guideline also gives some advice and policies regarding the method of cosmic radiation dosimetry, the necessity of explanation and education about this issue, a way to view and record dose data, and the necessity of medical examination for crew. The National Institute of Radiological Sciences helps the airlines to follow the guideline, particularly for the determination of aviation route doses by numerical simulation. The calculation is performed using an original, easy-to-use program package called 'JISCARD EX' coupled with a PHITS-based analytical model and a GEANT4-based particle tracing code. The new radiation weighting factors recommended in 2007 are employed for effective dose determination. The annual individual doses of aircraft crew were estimated using this program. PMID:21613269

Yasuda, Hiroshi; Sato, Tatsuhiko; Yonehara, Hidenori; Kosako, Toshiso; Fujitaka, Kazunobu; Sasaki, Yasuhito

2011-07-01

251

Study Regarding Electromagnetic Radiation Exposure Generated By Mobile Phone  

SciTech Connect

Number of mobile phone users reached to 5 billion subscribers in 2010 [ABI Research, 2010]. A large number of studies illustrated the public concern about adverse effects of mobile phone radiation and possible health hazards. Position of mobile phone use in close proximity to the head leads the main radiation between the hand and the head. Many investigations studying the possible effects of mobile phone exposure, founded no measurable effects of short-term mobile phone radiation, and there was no evidence for the ability to perceive mobile phone EMF in the general population. In this study, field radiation measurements were performed on different brand and different models of mobile phones in active mode, using an EMF RF Radiation Field Strength Power Meter 1 MHz-8 GHz. The study was effectuated on both the 2G and 3G generations phones connected to the providers operating in the frequency range 450 MHz-1800 MHz. There were recorded values in outgoing call and SMS mode, incoming call and SMS mode. Results were compared with ICNIRP guidelines for exposure to general public.

Marica, Lucia [Faculty of Sciences, PhD Student, University DUNAREA DE JOS of Galati, Str. Domneasca nr. 47, 800008 Galati (Romania); Moraru, Luminita [Department of Physics, Faculty of Sciences, University DUNAREA DE JOS of Galati, Str. Domneasca nr. 47, 800008 Galati (Romania)

2011-12-26

252

Study Regarding Electromagnetic Radiation Exposure Generated By Mobile Phone  

NASA Astrophysics Data System (ADS)

Number of mobile phone users reached to 5 billion subscribers in 2010 [ABI Research, 2010]. A large number of studies illustrated the public concern about adverse effects of mobile phone radiation and possible health hazards. Position of mobile phone use in close proximity to the head leads the main radiation between the hand and the head. Many investigations studying the possible effects of mobile phone exposure, founded no measurable effects of short-term mobile phone radiation, and there was no evidence for the ability to perceive mobile phone EMF in the general population. In this study, field radiation measurements were performed on different brand and different models of mobile phones in active mode, using an EMF RF Radiation Field Strength Power Meter 1 MHz-8 GHz. The study was effectuated on both the 2G and 3G generations phones connected to the providers operating in the frequency range 450 MHz-1800 MHz. There were recorded values in outgoing call and SMS mode, incoming call and SMS mode. Results were compared with ICNIRP guidelines for exposure to general public.

Marica, Lucia; Moraru, Luminita

2011-12-01

253

Modelling of radiation exposure at high altitudes during solar storms.  

PubMed

A transport code analysis using Monte Carlo N-Particle eXtended code, MCNPX, has been used to propagate an extrapolated particle spectrum based on satellite measurements through the atmosphere to estimate radiation exposure during solar storms at high altitudes. Neutron monitor count rate data from stations around the world were used to benchmark the model calculations during a ground-level event (GLE). A comparison was made between the model predictions and actual flight measurements taken with various types of instruments used to measure the mixed radiation field during GLE 60. A computer code has been developed to implement the model for routine analysis. PMID:19608577

Al Anid, H; Lewis, B J; Bennett, L G I; Takada, M

2009-10-01

254

28 CFR Appendix C to Part 79 - Radiation Exposure Compensation Act Offset Worksheet-On Site Participants  

...Radiation Exposure Compensation Act Offset Worksheet-On Site Participants C Appendix...Radiation Exposure Compensation Act Offset Worksheet—On Site Participants Radiation Exposure Compensation Act Offset Worksheet—On Site Participants...

2014-07-01

255

28 CFR Appendix C to Part 79 - Radiation Exposure Compensation Act Offset Worksheet-On Site Participants  

Code of Federal Regulations, 2013 CFR

...Radiation Exposure Compensation Act Offset Worksheet-On Site Participants C Appendix...Radiation Exposure Compensation Act Offset Worksheet—On Site Participants Radiation Exposure Compensation Act Offset Worksheet—On Site Participants...

2013-07-01

256

28 CFR Appendix C to Part 79 - Radiation Exposure Compensation Act Offset Worksheet-On Site Participants  

Code of Federal Regulations, 2011 CFR

...Radiation Exposure Compensation Act Offset Worksheet-On Site Participants C Appendix...Radiation Exposure Compensation Act Offset Worksheet—On Site Participants Radiation Exposure Compensation Act Offset Worksheet—On Site Participants...

2011-07-01

257

28 CFR Appendix C to Part 79 - Radiation Exposure Compensation Act Offset Worksheet-On Site Participants  

Code of Federal Regulations, 2012 CFR

...Radiation Exposure Compensation Act Offset Worksheet-On Site Participants C Appendix...Radiation Exposure Compensation Act Offset Worksheet—On Site Participants Radiation Exposure Compensation Act Offset Worksheet—On Site Participants...

2012-07-01

258

28 CFR Appendix C to Part 79 - Radiation Exposure Compensation Act Offset Worksheet-On Site Participants  

Code of Federal Regulations, 2010 CFR

...Radiation Exposure Compensation Act Offset Worksheet-On Site Participants C Appendix...Radiation Exposure Compensation Act Offset Worksheet—On Site Participants Radiation Exposure Compensation Act Offset Worksheet—On Site Participants...

2010-07-01

259

Occupational radiation Exposure at Agreement State-Licensed Materials Facilities, 1997-2010  

SciTech Connect

The purpose of this report is to examine occupational radiation exposures received under Agreement State licensees. As such, this report reflects the occupational radiation exposure data contained in the Radiation Exposure Information and Reporting System (REIRS) database, for 1997 through 2010, from Agreement State-licensed materials facilities.

U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research

2012-07-07

260

Atomic veterans and their families: Responses to radiation exposure  

SciTech Connect

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

Murphy, B.C.; Ellis, P.; Greenberg, S. (Wheaton College, Norton, MA (USA))

1990-07-01

261

Occupational exposure control: the problem of quantities in radiation protection.  

PubMed

The paper explores the quantities and units used in radiation protection with special emphasis on their applications in occupational exposure control. An overview of the current situation reveals that there seem to be too many different quantities associated with the same unit. Some of these quantities are defined in a quite complicated manner and, therefore, may cause some confusion in their interpretation and practical use in the field. Some suggestions towards the simplification of the present system are also proposed. PMID:21084329

Sabol, J; Navrátil, L; Rosina, J

2011-03-01

262

Radiation Exposure Alters Expression of Metabolic Enzyme Genes In Mice  

NASA Technical Reports Server (NTRS)

Most pharmaceuticals are metabolized by the liver. The health of the liver, especially the rate of its metabolic enzymes, determines the concentration of circulating drugs as well as the duration of their efficacy. Because of the importance of the liver in drug metabolism it is important to understand the effects of spaceflight on the enzymes of the liver. Exposure to cosmic radiation is one aspect of spaceflight that can be modeled in ground experiments. This study is an effort to examine the effects of adaptive mechanisms that may be triggered by early exposure to low radiation doses. Using procedures approved by the JSC Animal Care & Use Committee, C57 male mice were exposed to Cs-137 in groups: controls, low dose (50 mGy), high dose (6Gy) and a fourth group that received both radiation doses separated by 24 hours. Animals were anesthetized and sacrificed 4 hours after their last radiation exposure. Livers were removed immediately and flash-frozen in liquid nitrogen. Tissue was homogenized, RNA extracted and purified (Absolutely RNA, Agilent). Quality of RNA samples was evaluated (Agilent Bioanalyzer 2100). Complementary DNA was prepared from high-quality RNA samples, and used to run RT-qPCR screening arrays for DNA Repair and Drug Metabolism (SuperArray, SABiosciences/Qiagen; BioRad Cfx96 qPCR System). Of 91 drug metabolism genes examined, expression of 7 was altered by at least one treatment condition. Genes that had elevated expression include those that metabolize promethazine and steroids (4-8-fold), many that reduce oxidation products, and one that reduces heavy metal exposure (greater than 200-fold). Of the 91 DNA repair and general metabolism genes examined, expression of 14 was altered by at least one treatment condition. These gene expression changes are likely homeostatic and could lead to development of new radioprotective countermeasures.

Wotring, Virginia E.; Mangala, L. S.; Zhang, Y.; Wu, H.

2010-01-01

263

Intrinsic microwave radiation from the human body  

Microsoft Academic Search

tions in medicine and biology. Recently, researchers have been attracted by the possibility of developing a diagnostic tool based on detection of the intrinsic electromagnetic radiation from the human body, radiation which is due to the thermal motion of electrons in biological tissue. The intensity of this radiation is proportional to the temperature of the region of the body from

V. S. Troitskii; V. I. Abramov; I. F. Belov; V. P. Gorbachev; A. V. Gustov; V. M. Plechkov; L. K. Siz'mina

1981-01-01

264

TOLUENE EXPERIMENTAL EXPOSURES IN HUMANS: PHARMACOKINETICS AND BEHAVIOR  

EPA Science Inventory

Toluene Experimental Exposures in Humans: Pharmacokinetics and Behavioral Effects (Ongoing Research) Vernon A. Benignus1, Philip J. Bushnell2 and William K. Boyes2 Human subjects will be exposed to 250 and 500 ppm toluene for one hour in the Human St...

265

Relationship of cigarette smoking and radiation exposure to cancer mortality in Hiroshima and Nagasaki  

SciTech Connect

Cancer mortality among 40,498 Hiroshima and Nagasaki residents was examined in relation to cigarette smoking habits and estimated atomic bomb radiation exposure level. Relative risk (RR) models that are either multiplicative or additive in the two exposures were emphasized. Most analyses were directed toward all nonhematologic (ANH) cancer, stomach cancer, lung cancer, or digestive tract cancer other than stomach cancer, for which there were, respectively, 1,725, 658, 281, and 338 deaths in the follow-up period for this study. Persons heavily exposed to both cigarette smoke and radiation were found to have significantly lower cancer mortality than multiplicative RR models would suggest for ANH cancer, stomach cancer, and digestive tract cancer other than stomach cancer. Surprisingly, the RR function appeared not only to be submultiplicative for some of these cancer site categories but also may be subadditive. The lung cancer RR function could not be distinguished from either a multiplicative or an additive form. The number of deaths was sufficient to permit some more detailed study of ANH cancer mortality: RR functions appeared to be consistent between males and females, though a paucity of heavy smoking females limits the precision of this comparison. The submultiplicative nature of the RR function mentioned above was particularly pronounced among persons who were relatively young (less than or equal to 30 yr of age) at the time of radiation exposure. The RR function for these younger subjects depends strongly on both radiation and cigarette smoke exposure levels. Implications of these findings are discussed in relation to human carcinogenesis models. As a byproduct, cancer mortality of several sites is significantly related to radiation exposure in this population, after accommodation for the possible confounding effects of cigarette smoking.

Prentice, R.L.; Yoshimoto, Y.; Mason, M.W.

1983-04-01

266

ASSESSING RESIDENTIAL EXPOSURE USING THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION (SHEDS) MODEL  

EPA Science Inventory

As part of a workshop sponsored by the Environmental Protection Agency's Office of Research and Development and Office of Pesticide Programs, the Aggregate Stochastic Human Exposure and Dose Simulation (SHEDS) Model was used to assess potential aggregate residential pesticide e...

267

Assessing exposure to cosmic radiation on board aircraft.  

PubMed

The assessment of exposure to cosmic radiation on board aircraft is one of the preoccupations of organizations responsible for radiation protection. The cosmic radiation particle flux increases with altitude and latitude and depends on the solar activity. The radiation exposure has been estimated on several airlines using transatlantic, Siberian and transequatorial routes on board subsonic and supersonic aircraft, to illustrate the effect of these parameters. Measurements have been obtained with a tissue equivalent proportional counter using the microdosimetric technique. Data have been collected at maximum solar activity in 1991-92 and at minimum in 1996-98. The lowest mean dose rate measured was 3 microSv/h during a Paris-Buenos Aires flight in 1991; the highest was 6.6 microSv/h during a Paris-Tokyo flight using a Siberian route and 9.7 microSv/h on Concorde in 1996-97. The mean quality factor is around 1.8. The corresponding annual effective dose, based on 700 hours of flight for subsonic aircraft and 300 hours for Concorde, can be estimated between 2 mSv for least-exposed routes and 5 mSv for more exposed routes. PMID:14727664

Bottollier-Depois, J F; Chau, Q; Bouisset, P; Kerlau, G; Plawinski, L; Lebaron-Jacobs, L

2003-01-01

268

Medical mitigation strategies for acute radiation exposure during spaceflight.  

PubMed

The United States Government has recently refocused their space program on manned missions to the Moon by 2018 and later to Mars. While there are many potential risks associated with exploration-class missions, one of the most serious and unpredictable is the effect of acute space radiation exposure, and the space program must make every reasonable effort to mitigate this risk. The two cosmic sources of radiation that could impact a mission outside the Earth's magnetic field are solar particle events (SPE) and galactic cosmic radiation (GCR). Either can cause acute and chronic medical illness. Numerous researchers are currently examining the ability of GCR exposure to induce the development of genetic changes that lead to malignancies and other delayed effects. However, relatively little has been published on the medical management of an acute SPE event and the potential impact on the mission and crew. This review paper will provide the readers with medical management options for an acute radiation event based on recommendations from the Department of Homeland Security (DHS), Centers for Disease Control (CDC), and evidence-based critical analysis of the scientific literature. It is the goal of this paper to stimulate debate regarding the definition of safety parameters for exploration-class missions to determine the level of medical care necessary to provide for the crew that will undertake such missions. PMID:16491581

Epelman, Slava; Hamilton, Douglas R

2006-02-01

269

Interleukin-12 preserves the cutaneous physical and immunological barrier after radiation exposure.  

PubMed

The United States continues to be a prime target for attack by terrorist organizations in which nuclear detonation and dispersal of radiological material are legitimate threats. Such attacks could have devastating consequences to large populations, in the form of radiation injury to various human organ systems. One of these at risk organs is the cutaneous system, which forms both a physical and immunological barrier to the surrounding environment and is particularly sensitive to ionizing radiation. Therefore, increased efforts to develop medical countermeasures for treatment of the deleterious effects of cutaneous radiation exposure are essential. Interleukin-12 (IL-12) was shown to elicit protective effects against radiation injury on radiosensitive systems such as the bone marrow and gastrointestinal tract. In this article, we examined if IL-12 could protect the cutaneous system from a combined radiation injury in the form of sublethal total body irradiation and beta-radiation burn (?-burn) directly to the skin. Combined radiation injury resulted in a breakdown in skin integrity as measured by transepidermal water loss, size of ?-burn lesion and an exacerbated loss of surveillant cutaneous dendritic cells. Interestingly, intradermal administration of IL-12 48 h postirradiation reduced transepidermal water loss and burn size, as well as retention of cutaneous dendritic cells. Our data identify IL-12 as a potential mitigator of radiation-induced skin injury and argue for the further development of this cytokine as a radiation countermeasure. PMID:25564716

Gerber, Scott A; Cummings, Ryan J; Judge, Jennifer L; Barlow, Margaret L; Nanduri, Julee; Johnson, Doug E Milano; Palis, James; Pentland, Alice P; Lord, Edith M; Ryan, Julie L

2015-01-01

270

HEALTH RISKS OF HUMAN EXPOSURE TO WASTEWATER  

EPA Science Inventory

The primary objective of this research was to determine the health effects, if any, associated with occupational exposure to biological agents present in municipal wastewater. An additional objective was to determine the sensitivity of the methodology for detecting potential heal...

271

SECOND NATIONAL REPORT ON HUMAN EXPOSURE TO ENVIRONMENTAL CHEMICALS  

EPA Science Inventory

The National Report on Human Exposure to Environmental Chemicals is an ongoing assessment of the exposure of the U.S. population to environmental chemicals using biomonitoring. The first Report on 27 chemicals was issued in March 2001. This Second Report, released in January 20...

272

Human Exposures to Pesticides in the United States  

Microsoft Academic Search

Pesticides are used in most homes, businesses, and farms to control a variety of pests, including insects, weeds, fungi, rodents, and even microbial organisms. Inappropriate use of pesticides can lead to adverse effects to humans and the environment. This study provides updated information on the magnitude of adverse pesticide exposures in the United States. Data on pesticide exposure were obtained

Ricky L. Langley; Sandra Amiss Mort

2012-01-01

273

NATIONAL REPORT ON HUMAN EXPOSURE TO ENVIRONMENTAL CHEMICALS  

EPA Science Inventory

The National Report on Human Exposure to Environmental Chemicals is a new publication that will provide an ongoing assessment of the U.S. population's exposure to environmental chemicals using biomonitoring. For this Report, an environmental chemical means a chemical compound or ...

274

SECOND NATIONAL REPORT ON HUMAN EXPOSURES TO ENVIRONMENTAL CHEMICALS  

EPA Science Inventory

This report provides an ongoing assessment of the U.S. population's exposure to environmental chemicals using biomonitoring. The first National Report on Human Exposure to Environmental Chemicals (First Report) was issued in March 2001. This Second Report, released in January 200...

275

INTEGRATED HUMAN EXPOSURE SOURCE-TO-DOSE MODELING  

EPA Science Inventory

The NERL human exposure research program is designed to provide a sound, scientifically-based approach to understanding how people are actually exposed to pollutants and the factors and pathways influencing exposure and dose. This research project serves to integrate and incorpo...

276

Human Exposures to PAHs: an Eastern United States Pilot Study  

EPA Science Inventory

Personal exposure monitoring for select polycyclic aromatic hydrocarbons (PAHs) was performed as part of the National Human Exposure Assessment Survey (NHEXAS) Pilot Study in Baltimore, MD and in four surrounding counties (NHEXAS-Maryland). An objective of this effort was to esta...

277

Controlled human exposures to ambient pollutant particles in susceptible populations  

EPA Science Inventory

Epidemiologic studies have established an association between exposures to air pollution particles and human mortality and morbidity at concentrations of particles currently found in major metropolitan areas. The adverse effects of pollution particles are most prominent in suscep...

278

Exposure to solar ultraviolet radiation is associated with a decreased folate status in women of childbearing age.  

PubMed

In vitro studies indicate that folate in collected human blood is vulnerable to degradation after exposure to ultraviolet (UV) radiation. This has raised concerns about folate depletion in individuals with high sun exposure. Here, we investigate the association between personal solar UV radiation exposure and serum folate concentration, using a three-week prospective study that was undertaken in females aged 18-47years in Brisbane, Australia (153 E, 27 S). Following two weeks of supplementation with 500?g of folic acid daily, the change in serum folate status was assessed over a 7-day period of measured personal sun exposure. Compared to participants with personal UV exposures of <200 Joules per day, participants with personal UV exposures of 200-599 and >600 Joules per day had significantly higher depletion of serum folate (p=0.015). Multivariable analysis revealed personal UV exposure as the strongest predictor accounting for 20% of the overall change in serum folate (Standardised B=-0.49; t=-3.75; p=<0.01). These data show that increasing solar UV radiation exposures reduces the effectiveness of folic acid supplementation. The consequences of this association may be most pronounced for vulnerable individuals, such as women who are pregnant or of childbearing age with high sun exposures. PMID:24509071

Borradale, D; Isenring, E; Hacker, E; Kimlin, M G

2014-02-01

279

Environmental chemical exposures and human epigenetics  

PubMed Central

Every year more than 13 million deaths worldwide are due to environmental pollutants, and approximately 24% of diseases are caused by environmental exposures that might be averted through preventive measures. Rapidly growing evidence has linked environmental pollutants with epigenetic variations, including changes in DNA methylation, histone modifications and microRNAs. Environ mental chemicals and epigenetic changes All of these mechanisms are likely to play important roles in disease aetiology, and their modifications due to environmental pollutants might provide further understanding of disease aetiology, as well as biomarkers reflecting exposures to environmental pollutants and/or predicting the risk of future disease. We summarize the findings on epigenetic alterations related to environmental chemical exposures, and propose mechanisms of action by means of which the exposures may cause such epigenetic changes. We discuss opportunities, challenges and future directions for future epidemiology research in environmental epigenomics. Future investigations are needed to solve methodological and practical challenges, including uncertainties about stability over time of epigenomic changes induced by the environment, tissue specificity of epigenetic alterations, validation of laboratory methods, and adaptation of bioinformatic and biostatistical methods to high-throughput epigenomics. In addition, there are numerous reports of epigenetic modifications arising following exposure to environmental toxicants, but most have not been directly linked to disease endpoints. To complete our discussion, we also briefly summarize the diseases that have been linked to environmental chemicals-related epigenetic changes. PMID:22253299

Hou, Lifang; Zhang, Xiao; Wang, Dong; Baccarelli, Andrea

2012-01-01

280

[Estimation of radiation exposure and radiation risk for employees of a heart catheterization laboratory].  

PubMed

The staff at interventional radiological procedures is exposed to high levels of ionizing radiation. This applies especially to measures at cardiac catheterization laboratories. In this study the annual radiation exposure to the staff was estimated by measuring the dose rate under characteristic conditions. It could be shown that the resulting radiation exposure was strongly dependent on the radiation protection measures and is also dependent on the operation conditions of the x-ray-tube. The effective dose for the physician wearing a lead apron and thyroid shield was determined to about 1.7 mSv/a. Without a thyroid shield an effective dose of about 3.5 mSv/a resulted. This corresponds to approximately the natural background radiation of about 2.4 mSv/a in the Federal Republic of Germany. From the number of procedures performed we could derive an effective dose of approximately 1-2 microSv per application for the physician, averaged over all types of procedures. Further, it could be shown that the readings of the film badges, usually worn by the staff, underestimate the effective dose by approximately a factor of two. This is because the film badges do not include the contribution of the unshielded parts of the body to effective dose. From the estimated annual effective dose, a lifetime dose of 68 mSv was estimated for a 40-year working career. The corresponding lifetime risk for induced fatal cancer due to radiation exposure was determined to 0.3% applying the ICRP risk factor of 4 x 10(-2) Sv-1. Considering the NCRP recommendations for a safe occupation, working in a cardiac catheterization laboratory can be considered as safe when applying all radiation protection measures. However, changing the protection measures and modifying the parameters of the x-ray-tube can lead to strong changes of the radiation exposure and the resulting risk estimation. PMID:9235797

Folkerts, K H; Münz, A; Jung, S

1997-04-01

281

Human exposure limits to hypergolic fuels  

NASA Technical Reports Server (NTRS)

Over the past four decades, many studies have been conducted on the toxicities of the rocket propellants hydrazine (HZ) and monomethylhydrazine (MH). Numerous technical challenges have made it difficult to unambiguously interpret the results of these studies, and there is considerable divergence between results obtained by different investigators on the inhalation concentrations (MAC's) for each toxic effect inducible by exposure to hypergolic fuels in spacecraft atmospheres, NASA undertook a critical review of published and unpublished investigations on the toxicities of these compounds. The current state of the art practices for similar studies. While many questions remain unanswered, MAC's were determined using the best available data for a variety of toxic endpoints for potential continuous exposure durations ranging from 1 hour to 180 days. Spacecraft MAC's (SMAC's) were set for each compound based on the most sensitive toxic endpoint at each exposure duration.

Garcia, H. D.; James, J. T.; Limero, T. F.

1992-01-01

282

MANAGEMENT AND DISSEMINATION OF HUMAN EXPOSURE DATABASES AND OTHER DATABASES NEEDED FOR HUMAN EXPOSURE MODELING AND ANALYSIS  

EPA Science Inventory

Researchers in the National Exposure Research Laboratory (NERL) have performed a number of large human exposure measurement studies during the past decade. It is the goal of the NERL to make the data available to other researchers for analysis in order to further the scientific ...

283

Computer Aided Dosimetry and Verification of Exposure to Radiation  

NASA Astrophysics Data System (ADS)

In the timeframe following the September 11th attacks on the United States, increased emphasis has been placed on Chemical, Biological, Radiological and Nuclear (CBRN) preparedness. Of prime importance is rapid field assessment of potential radiation exposure to Canadian Forces field personnel. This work set up a framework for generating an 'expert' computer system for aiding and assisting field personnel in determining the extent of radiation insult to military personnel. Data was gathered by review of the available literature, discussions with medical and health physics personnel having hands-on experience dealing with radiation accident victims, and from experience of the principal investigator. Flow charts and generic data fusion algorithms were developed. Relationships between known exposure parameters, patient interview and history, clinical symptoms, clinical work-ups, physical dosimetry, biological dosimetry, and dose reconstruction as critical data indicators were investigated. The data obtained was examined in terms of information theory. A main goal was to determine how best to generate an adaptive model (i.e. when more data becomes available, how is the prediction improved). Consideration was given to determination of predictive algorithms for health outcome. In addition. the concept of coding an expert medical treatment advisor system was developed (U)

Waller, Edward; Stodilka, Robert Z.; Leach, Karen E.; Lalonde, Louise

2002-06-01

284

Cognitive deficits induced by 56Fe radiation exposure  

NASA Astrophysics Data System (ADS)

Exposing rats to particles of high energy and charge (e.g., 56Fe) disrupts neuronal systems and the behaviors mediated by them; these adverse behavioral and neuronal effects are similar to those seen in aged animals. Because cognition declines with age, and our previous study showed that radiation disrupted Morris water maze spatial learning and memory performance, the present study used an 8-arm radial maze (RAM) to further test the cognitive behavioral consequences of radiation exposure. Control rats or rats exposed to whole-body irradiation with 1.0 Gy of 1 GeV/n high-energy 56Fe particles (delivered at the alternating gradient synchrotron at Brookhaven National Laboratory) were tested nine months following exposure. Radiation adversely affected RAM performance, and the changes seen parallel those of aging. Irradiated animals entered baited arms during the first 4 choices significantly less than did controls, produced their first error sooner, and also tended to make more errors as measured by re-entries into non-baited arms. These results show that irradiation with high-energy particles produces age-like decrements in cognitive behavior that may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere.

Shukitt-Hale, B.; Casadesus, G.; Cantuti-Castelvetri, I.; Rabin, B. M.; Joseph, J. A.

285

Cognitive deficits induced by 56Fe radiation exposure  

NASA Technical Reports Server (NTRS)

Exposing rats to particles of high energy and charge (e.g., 56Fe) disrupts neuronal systems and the behaviors mediated by them; these adverse behavioral and neuronal effects are similar to those seen in aged animals. Because cognition declines with age, and our previous study showed that radiation disrupted Morris water maze spatial learning and memory performance, the present study used an 8-arm radial maze (RAM) to further test the cognitive behavioral consequences of radiation exposure. Control rats or rats exposed to whole-body irradiation with 1.0 Gy of 1 GeV/n high-energy 56Fe particles (delivered at the alternating gradient synchrotron at Brookhaven National Laboratory) were tested nine months following exposure. Radiation adversely affected RAM performance, and the changes seen parallel those of aging. Irradiated animals entered baited arms during the first 4 choices significantly less than did controls, produced their first error sooner, and also tended to make more errors as measured by re-entries into non-baited arms. These results show that irradiation with high-energy particles produces age-like decrements in cognitive behavior that may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere. Published by Elsevier Science Ltd on behalf of COSPAR.

Shukitt-Hale, B.; Casadesus, G.; Cantuti-Castelvetri, I.; Rabin, B. M.; Joseph, J. A.

2003-01-01

286

Exposure of the thyroid to radiation during routine orthopaedic procedures.  

PubMed

The availability and usage of portable image intensifiers has revolutionised routine orthopaedic practice. Extensive use of fluoroscopy however may result into significant radiation exposure to operating staff. An accumulated dose of 65 microSv per procedure over long exposure has been reported to increase the risk of thyroid cancer. The present prospective study aimed at measuring the scattered dose to the thyroid using an Unfors EDD dosimeter during DHS/IMHS for fractures of the neck of the femur and IM nailing for long bone fractures. In 32 procedures, the dose of 65 microSv was exceeded 13 times; 8 times during DHS/IMHS and 5 times during IMN. The average thyroid dose was 142 microSv during IMN and 55 microSv during DHS. Only 9 of the total 223 (4%) theatre personnel were using a thyroid shield in spite of its availability. These results suggest that the thyroid is frequently exposed to potentially harmful radiation during these procedures. Strict inclusion of a thyroid shield as a part of routine radiation protection is recommended. PMID:17152427

Devalia, Kailash L; Peter, Viju K; Madanur, Mansoor A; Braithwaite, Ian J

2006-10-01

287

Identification of gene expression biomarkers for predicting radiation exposure.  

PubMed

A need for more accurate and reliable radiation dosimetry has become increasingly important due to the possibility of a large-scale radiation emergency resulting from terrorism or nuclear accidents. Although traditional approaches provide accurate measurements, such methods usually require tedious effort and at least two days to complete. Therefore, we provide a new method for rapid prediction of radiation exposure. Eleven microarray datasets were classified into two groups based on their radiation doses and utilized as the training samples. For the two groups, Student's t-tests and resampling tests were used to identify biomarkers, and their gene expression ratios were used to develop a prediction model. The performance of the model was evaluated in four independent datasets, and Ingenuity pathway analysis was performed to characterize the associated biological functions. Our meta-analysis identified 29 biomarkers, showing approximately 90% and 80% accuracy in the training and validation samples. Furthermore, the 29 genes significantly participated in the regulation of cell cycle, and 19 of them are regulated by three well-known radiation-modulated transcription factors: TP53, FOXM1 and ERBB2. In conclusion, this study demonstrates a reliable method for identifying biomarkers across independent studies and high and reproducible prediction accuracy was demonstrated in both internal and external datasets. PMID:25189756

Lu, Tzu-Pin; Hsu, Yi-Yao; Lai, Liang-Chuan; Tsai, Mong-Hsun; Chuang, Eric Y

2014-01-01

288

Determination of Important Nuclear Fragmentation Processes for Human Space Radiation Protection  

NASA Technical Reports Server (NTRS)

We present a semi-analytical method to determine which partial cross sections of nuclear fragmentations most affect the shielded dose equivalent due to exposure to galactic cosmic rays. The cross sections thus determined will require more theoretical and/or experimental studies in order for us to better predict, reduce and mitigate the radiation exposure in human space explorations.

Lin, Zi-Wei

2007-01-01

289

Elevated blood lead levels from exposure via a radiator workshop  

SciTech Connect

Elevated lead levels were discovered in blood samples collected from family members where both the father and the mother worked in a radiator repair workshop. The father and mother were found to have blood lead levels of 2.0 and 0.5 {micro}mol/L, respectively. The father`s blood lead level was just below the Canadian occupational health and safety intervention level. The two children had blood lead levels of 1.0 and 0.8 {micro}mol/L, both of which are in excess of the recommended guideline for intervention in the case of children. The exposure of the two children was possibly due to a combination of pathways including exposure at the workshop itself during visits and also the transportation of lead-containing dust to the home environment.

Treble, R.G.; Thompson, T.S. [Saskatchewan Health, Regina, Saskatchewan (Canada). Provincial Lab.] [Saskatchewan Health, Regina, Saskatchewan (Canada). Provincial Lab.; Morton, D.N. [North Battleford Medical Clinic, Saskatchewan (Canada)] [North Battleford Medical Clinic, Saskatchewan (Canada)

1998-04-01

290

Inferior retinal light exposure is more effective than superior retinal exposure in suppressing melatonin in humans  

NASA Technical Reports Server (NTRS)

Illumination of different areas of the human retina elicits differences in acute light-induced suppression of melatonin. The aim of this study was to compare changes in plasma melatonin levels when light exposures of equal illuminance and equal photon dose were administered to superior, inferior, and full retinal fields. Nine healthy subjects participated in the study. Plexiglass eye shields were modified to permit selective exposure of the superior and inferior halves of the retinas of each subject. The Humphrey Visual Field Analyzer was used both to confirm intact full visual fields and to quantify exposure of upper and lower visual fields. On study nights, eyes were dilated, and subjects were exposed to patternless white light for 90 min between 0200 and 0330 under five conditions: (1) full retinal exposure at 200 lux, (2) full retinal exposure at 100 lux, (3) inferior retinal exposure at 200 lux, (4) superior retinal exposure at 200 lux, and (5) a dark-exposed control. Plasma melatonin levels were determined by radioimmunoassay. ANOVA demonstrated a significant effect of exposure condition (F = 5.91, p < 0.005). Post hoc Fisher PLSD tests showed significant (p < 0.05) melatonin suppression of both full retinal exposures as well as the inferior retinal exposure; however, superior retinal exposure was significantly less effective in suppressing melatonin. Furthermore, suppression with superior retinal exposure was not significantly different from that of the dark control condition. The results indicate that the inferior retina contributes more to the light-induced suppression of melatonin than the superior retina at the photon dosages tested in this study. Findings suggest a greater sensitivity or denser distribution of photoreceptors in the inferior retina are involved in light detection for the retinohypothalamic tract of humans.

Glickman, Gena; Hanifin, John P.; Rollag, Mark D.; Wang, Jenny; Cooper, Howard; Brainard, George C.

2003-01-01

291

Delayed effects of external radiation exposure: A brief history  

SciTech Connect

Within months of Roentgen`s discovery of X rays, severe adverse effects were reported, but not well publicized. As a result, over the next two decades, fluoroscope operators suffered lethal skin carcinomas. Later, case reports appeared concerning leukemia in radiation workers, and infants born with severe mental retardation after their mothers had been given pelvic radiotherapy early in pregnancy. Fluoroscopy and radiotherapy for benign disorders continued to be used with abandon until authoritative reports were published on the adverse effects of ionizing radiation by the U.S. NAS-NRC and the UK MRC in 1956. Meanwhile, exposure to the atomic bombs in Japan had occurred and epidemics of delayed effects began to be recognized among the survivors: cataracts, leukemia and severe mental retardation among newborn infants after intra-uterine exposure. No statistically significant excess of germ-cell genetic effects was detected by six clinical measurements, the F{sub 1} mortality, cytogenetic studies or biochemical genetic studies. Somatic cell effects were revealed by long-lasting chromosomal aberrations in peripheral lymphocytes, and somatic cell mutations were found at the glycophorin A locus in erythrocytes. Molecular biology is a likely focus of new studies based on the function of the gene for ataxia telangiectasia, a disorder in which children have severe, even lethal acute radiation reactions when given conventional doses of radiotherapy for lymphoma, to which they are prone. The tumor registries in Hiroshima and Nagasaki now provide incidence data that show the extent of increases in eight common cancers and no increase in eight others. The possibility of very late effects of A-bomb exposure is suggested by recent reports of increased frequencies of hyperparathyroidism, parathyroid cancers and certain causes of death other than cancer. 88 refs., 1 fig.

Miller, R.W. [National Cancer Institute, Bethesda, MD (United States)

1995-11-01

292

Useful radiation dose biomarkers for early identification of partial-body exposures.  

PubMed

Although less urgent than the physical injuries caused by an unexpected nuclear and radiological (NR) event, radiation damages can be treated more effectively if the intensity and extent of the exposure are evaluated rapidly. In this work, the authors followed within the first 7 d after exposure a few early biomarkers that could be easily deployable (simple and fast sampling and analysis) to determine their potential in distinguishing a total body irradiation (TBI) from a dose-equivalent partial exposure. A plausible accident scenario was created for this study by exposing unilaterally nonhuman primates of body mass comparable to humans to 5 Gy, to either the whole body or to part of it. Using logistic regression analysis, it was shown that both a combination of three parameters together [absolute neutrophil count; monocyte count on the first day; and C-reactive protein (CRP) 5 d after exposure] or CRP 7 d after irradiation completely separated the partial exposures from the TBIs. A quasi-complete separation using receiver-operator characteristic (ROC) was observed for neutrophil count to lymphocyte count ratio during the first day after exposure. PMID:24776909

Hérodin, Francis; Valente, Marco; Abend, Michael

2014-06-01

293

Gamma-H2AX-Based Dose Estimation for Whole and Partial Body Radiation Exposure  

PubMed Central

Most human exposures to ionising radiation are partial body exposures. However, to date only limited tools are available for rapid and accurate estimation of the dose distribution and the extent of the body spared from the exposure. These parameters are of great importance for emergency triage and clinical management of exposed individuals. Here, measurements of ?-H2AX immunofluorescence by microscopy and flow cytometry were compared as rapid biodosimetric tools for whole and partial body exposures. Ex vivo uniformly X-irradiated blood lymphocytes from one donor were used to generate a universal biexponential calibration function for ?-H2AX foci/intensity yields per unit dose for time points up to 96 hours post exposure. Foci – but not intensity – levels remained significantly above background for 96 hours for doses of 0.5 Gy or more. Foci-based dose estimates for ex vivo X-irradiated blood samples from 13 volunteers were in excellent agreement with the actual dose delivered to the targeted samples. Flow cytometric dose estimates for X-irradiated blood samples from 8 volunteers were in excellent agreement with the actual dose delivered at 1 hour post exposure but less so at 24 hours post exposure. In partial body exposures, simulated by mixing ex vivo irradiated and unirradiated lymphocytes, foci/intensity distributions were significantly over-dispersed compared to uniformly irradiated lymphocytes. For both methods and in all cases the estimated fraction of irradiated lymphocytes and dose to that fraction, calculated using the zero contaminated Poisson test and ?-H2AX calibration function, were in good agreement with the actual mixing ratios and doses delivered to the samples. In conclusion, ?-H2AX analysis of irradiated lymphocytes enables rapid and accurate assessment of whole body doses while dispersion analysis of foci or intensity distributions helps determine partial body doses and the irradiated fraction size in cases of partial body exposures. PMID:21966430

Horn, Simon; Barnard, Stephen; Rothkamm, Kai

2011-01-01

294

[Radiation exposure and air quality aboard commercial airplanes].  

PubMed

The amount of exposure to cosmic radiation during air travel is next to a number of additional factors mainly dependent on the flight level of the aircraft. Flying in an altitude of 41,000 feet equaling 12,800 meters the amount of radiation exposure is of course considerable higher than on the ground. The overall exposure of flying personnel to cosmic radiation flying about 600-700 hours per year can be estimated between 3 and 6 mSv (300-600 mrem). According to the flight hours of passengers, the radiation exposure is much lower and can be neglected for most of the travelers final judgement about the possible risks for flying personnel as far as a higher incident of malignant tumors is concerned has not jet been finally made. Talking of cabin air quality compromises have to be made and thus the well-being of the passengers can be negatively influenced. Air pressure and oxygen partial pressure correspond to an altitude of 2400 meters (8,000 feet) above sea level with possible consequences to the cardiopulmonary system. Increased level of ozone can lead to respiratory problems of the upper airways, increased carbon dioxide may cause hyperventilation. The mucous membranes of the respiratory tract are dried out due to the extremely low humidity of the cabin air. Smoking during flight results in an increase of the nicotine blood levels even in passengers sitting in the non-smoking areas. In modern aircraft the fresh-air flow cannot be regulated individually any more, this may lead to an insufficient circulation of used air in relation to fresh air and could cause the phenomena of hanging smoke. There has always been the idea that there is an increased risk for passengers for acquiring infectious diseases. However this is not the case. Modern HEPA-filter prevent an accumulation even of the smallest particles including bacteria and viruses within the recirculation flow in the cabin air. The overall risk of getting an infectious disease is significantly lower than in other ground operated public means of transportation. PMID:10568250

Bergau, L

1999-10-01

295

Development of a predictive code for aircrew radiation exposure.  

PubMed

Using the empirical data measured by the Royal Military College with a tissue equivalent proportional counter, a model was derived to allow for the interpolation of the dose rate for any global position, altitude and date. Through integration of the dose-rate function over a great circle flight path or between various waypoints, a Predictive Code for Aircrew Radiation Exposure (PCAire) was further developed to provide an estimate of the total dose equivalent on any route worldwide at any period in the solar cycle. PMID:19617241

McCall, M J; Lemay, F; Bean, M R; Lewis, B J; Bennett, L G I

2009-10-01

296

FLUORESCENCE DEPOLARIZATION STUDIES OF RED CELL MEMBRANE FLUIDITY. THE EFFECT OF EXPOSURE TO 1.0-GHZ MICROWAVE RADIATION  

EPA Science Inventory

The internal viscosity of human red blood cell membranes was investigated during exposure to continuous wave 1.0-GHz microwave radiation using fluorescence measurements of a lipid seeking molecular probe, diphenylhexatriene. Samples were exposed in a Crowford cell arranged so tha...

297

MULTIPLE SOLVENT EXPOSURE IN HUMANS: CROSS-SPECIES EXTRAPOLATIONS  

EPA Science Inventory

Multiple Solvent Exposures in Humans: Cross-Species Extrapolations (Future Research Plan) Vernon A. Benignus1, Philip J. Bushnell2 and William K. Boyes2 A few solvents can be safely studied in acute experiments in human subjects. Data exist in rats f...

298

THE NATIONAL EXPOSURE RESEARCH LABORATORY'S COMPREHENSIVE HUMAN ACTIVITY DATABASE  

EPA Science Inventory

EPA's National Exposure Research Laboratory (NERL) has combined data from nine U.S. studies related to human activities into one comprehensive data system that can be accessed via the world-wide web. The data system is called CHAD-Consolidated Human Activity Database-and it is ...

299

TOTAL HUMAN EXPOSURE MODEL (THEM) FOR RESPIRABLE SUSPENDED PARTICLES (RSP)  

EPA Science Inventory

A Total Human Exposure Model (THEM) has been developed that calculates 24-hour profiles using real human activity patterns and indoor air models derived from actual measurements of pollutants. HEM was designed for implementation on personal computers. urrently, the model uses the...

300

LEAD EXPOSURES IN THE HUMAN ENVIRONMENT  

EPA Science Inventory

Humans consume lead by inhaling air, drinking beverages, eating food and ingesting dust. The natural source of this lead is primarily soil. Anthropogenic sources are lead in gasoline, fossil fuels and industrial products and processes. Lead is ubiquitous in the human environment,...

301

Measurements of human body microwave radiation  

Microsoft Academic Search

Major problems of registering microwave radiation of human body have been considered. It is pointed out that they are caused by at least three factors which may considerably influence the experimental results and their interpretation, namely: (1) properties of the radiation (their low intensity primarily); (2) features of measurements that implement waveguide techniques; (3) peculiar features of the emission medium

G. V. Ponezha; S. G. Ponezha; A. I. Nizhelskaya

2003-01-01

302

Non-Malignant Thyroid Diseases Following a Wide Range of Radiation Exposures  

PubMed Central

Background The thyroid gland is one of the most radiosensitive human organs. While it is well known that radiation exposure increases the risk of thyroid cancer, less is known about its effects in relation to non-malignant thyroid diseases. Objectives The aim of this review is to evaluate the effects of high and low dose radiation on benign structural and functional diseases of the thyroid. Methods We examined the results of major studies from cancer patients treated with high-dose radiotherapy or thyrotoxicosis patients treated with high doses of iodine-131, patients treated with moderate to high dose radiotherapy for benign diseases, persons exposed to low doses from environmental radiation and survivors of the atomic bombings who were exposed to a range of doses. We evaluated radiation effects on structural (tumors, nodules), functional (hyper- and hypothyroidism), and autoimmune thyroid diseases. Results Following a wide range of doses of ionizing radiation, an increased risk of thyroid adenomas and nodules was observed in a variety of populations and settings. The dose response appeared to be linear at low to moderate doses, but in one study there was some suggestion of a reduction in risk above 5 Gy. The elevated risk for benign tumors continues for decades following exposure. Considerably less consistent findings are available regarding functional thyroid diseases including autoimmune diseases. In general, associations for these outcomes were fairly weak and significant radiation effects were most often observed following high doses, particularly for hypothyroidism. Conclusions A significant radiation dose-response relation was demonstrated for benign nodules and follicular adenomas. The effects of radiation on functional thyroid diseases are less clear, partly due to the greater difficulties studying these diseases. PMID:21128812

Ron, Elaine; Brenner, Alina

2013-01-01

303

TELOMERE SHORTENING: A NEW PROGNOSTIC FACTOR FOR CARDIOVASCULAR DISEASE POST-RADIATION EXPOSURE.  

PubMed

Telomere length has been proposed as a marker of mitotic cell age and as a general index of human organism aging. Telomere shortening in peripheral blood lymphocytes has been linked to cardiovascular-related morbidity and mortality. The authors investigated the potential correlation of conventional risk factors, radiation dose and telomere shortening with the development of coronary artery disease (CAD) following radiation therapy in a large cohort of Hodgkin lymphoma (HL) patients. Multivariate analysis demonstrated that hypertension and telomere length were the only independent risk factors. This is the first study in a large cohort of patients that demonstrates significant telomere shortening in patients treated by radiation therapy who developed cardiovascular disease. Telomere length appears to be an independent prognostic factor that could help determine patients at high risk of developing CAD after exposure in order to implement early detection and prevention. PMID:25274533

M'kacher, R; Girinsky, T; Colicchio, B; Ricoul, M; Dieterlen, A; Jeandidier, E; Heidingsfelder, L; Cuceu, C; Shim, G; Frenzel, M; Lenain, A; Morat, L; Bourhis, J; Hempel, W M; Koscielny, S; Paul, J F; Carde, P; Sabatier, L

2014-10-01

304

Increased Artemis levels confer radioresistance to both high and low LET radiation exposures  

PubMed Central

Background Artemis has a defined role in V(D)J recombination and has been implicated in the repair of radiation induced double-strand breaks. However the exact function(s) of Artemis in DNA repair and its preferred substrate(s) in vivo remain undefined. Our previous work suggests that Artemis is important for the repair of complex DNA damage like that inflicted by high Linear Energy Transfer (LET) radiation. To establish the contribution of Artemis in repairing DNA damage caused by various radiation qualities, we evaluated the effect of over-expressing Artemis on cell survival, DNA repair, and cell cycle arrest after exposure to high and low LET radiation. Results Our data reveal that Artemis over-expression confers marked radioprotection against both types of radiation, although the radioprotective effect was greater following high LET radiation. Inhibitor studies reveal that the radioprotection imparted by Artemis is primarily dependent on DNA-PK activity, and to a lesser extent on ATM kinase activity. Together, these data suggest a DNA-PK dependent role for Artemis in the repair of complex DNA damage. Conclusions These findings indicate that Artemis levels significantly influence radiation toxicity in human cells and suggest that Artemis inhibition could be a practical target for adjuvant cancer therapies. PMID:22713703

2012-01-01

305

OVERVIEW OF THE U.S. EPA NERL'S HUMAN EXPOSURE MODELING  

EPA Science Inventory

Computational modeling of human exposure to environmental pollutants is one of the primary activities of the US Environmental Protection Agency's National Exposure Research Laboratory (NERL). Assessment of human exposures is a critical part of the overall risk assessment para...

306

Analysis of rat testicular proteome following 30-day exposure to 900 MHz electromagnetic field radiation.  

PubMed

The use of electromagnetic field (EMF) generating apparatuses such as cell phones is increasing, and has caused an interest in the investigations of its effects on human health. We analyzed proteome in preparations from the whole testis in adult male Sprague-Dawley rats that were exposed to 900 MHz EMF radiation for 1, 2, or 4 h/day for 30 consecutive days, simulating a range of possible human cell phone use. Subjects were sacrificed immediately after the end of the experiment and testes fractions were solubilized and separated via high-resolution 2D electrophoresis, and gel patterns were scanned, digitized, and processed. Thirteen proteins, which were found only in sham or in exposure groups, were identified by MALDI-TOF/TOF-MS. Among them, heat shock proteins, superoxide dismutase, peroxiredoxin-1, and other proteins related to misfolding of proteins and/or stress were identified. These results demonstrate significant effects of radio frequency modulated EMFs exposure on proteome, particularly in protein species in the rodent testis, and suggest that a 30-day exposure to EMF radiation induces nonthermal stress in testicular tissue. The functional implication of the identified proteins was discussed. PMID:25146694

Sepehrimanesh, Masood; Kazemipour, Nasrin; Saeb, Mehdi; Nazifi, Saeed

2014-12-01

307

HUMAN HEALTH IMPACTS OF EXPOSURE TO POPS  

EPA Science Inventory

The Stockholm Convention on persistent organic pollutants (POPs) was adopted in 2001 to protect human health and the environment from chemicals that are highly toxic, persistent, bioaccumulative and undergo long range transport. These POPs include 9 pesticides, polychlorinated d...

308

Assessing exposure to granite countertops--Part 1: Radiation.  

PubMed

Humans are continuously exposed to low levels of ionizing radiation. Known sources include radon, soil, cosmic rays, medical treatment, food, and building products such as gypsum board and concrete. Little information exists about radiation emissions and associated doses from natural stone finish materials such as granite countertops in homes. To address this knowledge gap, gross radioactivity, gamma ray activity, and dose rate were determined for slabs of granite marketed for use as countertops. Annual effective radiation doses were estimated from measured dose rates and human activity patterns while accounting for the geometry of granite countertops in a model kitchen. Gross radioactivity, gamma activity, and dose rate varied significantly among and within slabs of granite with ranges for median levels at the slab surface of ND to 3000 cpm, ND to 98,000 cpm, and ND to 1.5E-4 mSv/h, respectively. The maximum activity concentrations of the (40)K, (232)Th, and (226)Ra series were 2715, 231, and 450 Bq/kg, respectively. The estimated annual radiation dose from spending 4 h/day in a hypothetical kitchen ranged from 0.005 to 0.18 mSv/a depending on the type of granite. In summary, our results show that the types of granite characterized in this study contain varying levels of radioactive isotopes and that their observed emissions are consistent with those reported in the scientific literature. We also conclude from our analyses that these emissions are likely to be a minor source of external radiation dose when used as countertop material within the home and present a negligible risk to human health. PMID:19707248

Myatt, Theodore A; Allen, Joseph G; Minegishi, Taeko; McCarthy, William B; Stewart, James H; Macintosh, David L; McCarthy, John F

2010-05-01

309

Assessing exposure to cosmic radiation during long-haul flights.  

PubMed

The assessment of exposure to cosmic radiation on board aircraft is one of the concerns of organizations responsible for radiation protection. Cosmic-particle flux increases with altitude and latitude and depends on solar activity. To illustrate the effect of these parameters, exposure has been estimated on several airlines operating subsonic and supersonic aircraft on transatlantic, Siberian and transequatorial routes. Measurements have been made with a tissue-equivalent proportional counter using the microdosimetric technique. This type of system provides the absorbed dose, the ambient dose equivalent, the mean quality factor, and the dose distribution as a function of lineal energy. Data were collected at maximum solar activity in 1991-1992 and at minimum activity in 1996-1998. The lowest mean dose rate measured was 3 microSv h(-1) during a Paris-Buenos Aires flight in 1991. The highest rates were 6.6 microSv h(-1) during a Paris-Tokyo flight on a Siberian route and 9.7 microSv h(-1) on Concorde in 1996-1997. The mean quality factor is around 1.8. The corresponding annual effective dose, based on 700 h of flight for subsonic aircraft and 300 h for Concorde, can be estimated at between 2 mSv for the least-exposed routes and 5 mSv for the more-exposed routes. PMID:10790273

Bottollier-Depois, J F; Chau, Q; Bouisset, P; Kerlau, G; Plawinski, L; Lebaron-Jacobs, L

2000-05-01

310

ISSCREM: International Space Station cosmic radiation exposure model  

NASA Astrophysics Data System (ADS)

A semi-empirical model is derived from operational data collected aboard the International Space Station (ISS) with the U.S. tissue equivalent proportional counter (TEPC). The model provides daily and cumulative mission predictions of the operational dose equivalent that space-crew may receive from galactic cosmic radiation (GCR) and trapped radiation (TR) sources as a function of the ISS orbit. The parametric model for GCR exposure correlates the TEPC dose equivalent rate to the cutoff rigidity at ISS altitudes while the TR parametric model relates this quantity to the mean atmospheric density at the crossing of the South Atlantic Anomaly (SAA). The influences of solar activity, flux asymmetry inside the SAA, detector orientation, and position aboard the ISS on the dose equivalent have been examined. The model has been successfully benchmarked against measured data for GCR and TR exposures to within ± 10% and ± 20%, respectively, over periods of time ranging from a single day to a full mission. In addition, preliminary estimates of the protection quantity of effective dose equivalent have been simulated using the PHITS Monte Carlo transport code. These simulations indicate that the TEPC dose equivalent is a conservative estimate of the effective dose equivalent.

El-Jaby, Samy; Lewis, Brent J.; Tomi, Leena; Sihver, Lembit; Sato, Tatsuhiko; Lee, Kerry T.; Johnson, A. Steve

311

Experiment for radiation dose measurements in a human phantom onboard the ISS for estimation of the radiation risk in long duration space flights  

Microsoft Academic Search

Radiation exposure of crewmembers on manned space flight has been recognised as an important factor in the planning and design of such missions. Indeed, the effects of ionising radiation on crew health, performance and life expectancy are a limitation to the duration of man's sojourn in space. Predicting the effects of radiation on humans during a long-term space mission requires:

J. Semkova; R. Koleva; G. Todorova; N. Kanchev; V. Petrov; V. Shurshakov; E. Yarmanova; V. Benghin; I. Tchhernykh

2005-01-01

312

Radiation Exposure Effects and Shielding Analysis of Carbon Nanotube Materials  

NASA Technical Reports Server (NTRS)

Carbon nanotube materials promise to be the basis for a variety of emerging technologies with aerospace applications. Potential applications to human space flight include spacecraft shielding, hydrogen storage, structures and fixtures and nano-electronics. Appropriate risk analysis on the properties of nanotube materials is essential for future mission safety. Along with other environmental hazards, materials used in space flight encounter a hostile radiation environment for all mission profiles, from low earth orbit to interplanetary space.

Wilkins, Richard; Armendariz, Lupita (Technical Monitor)

2002-01-01

313

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Surveys of ambient radiation exposure rate. 35.70 Section 35...Requirements § 35.70 Surveys of ambient radiation exposure rate. (a) In addition...chapter, a licensee shall survey with a radiation detection survey instrument at...

2010-01-01

314

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Surveys of ambient radiation exposure rate. 35.70 Section 35...Requirements § 35.70 Surveys of ambient radiation exposure rate. (a) In addition...chapter, a licensee shall survey with a radiation detection survey instrument at...

2013-01-01

315

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Surveys of ambient radiation exposure rate. 35.70 Section 35...Requirements § 35.70 Surveys of ambient radiation exposure rate. (a) In addition...chapter, a licensee shall survey with a radiation detection survey instrument at...

2011-01-01

316

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Surveys of ambient radiation exposure rate. 35.70 Section 35...Requirements § 35.70 Surveys of ambient radiation exposure rate. (a) In addition...chapter, a licensee shall survey with a radiation detection survey instrument at...

2012-01-01

317

38 CFR 3.715 - Radiation Exposure Compensation Act of 1990, as amended.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Radiation Exposure Compensation Act of 1990, as...Benefits and Elections § 3.715 Radiation Exposure Compensation Act of 1990, as amended. (a) Compensation. (1) A radiation-exposed veteran, as defined in...

2013-07-01

318

38 CFR 3.715 - Radiation Exposure Compensation Act of 1990, as amended.  

...2014-07-01 2014-07-01 false Radiation Exposure Compensation Act of 1990, as...Benefits and Elections § 3.715 Radiation Exposure Compensation Act of 1990, as amended. (a) Compensation. (1) A radiation-exposed veteran, as defined in...

2014-07-01

319

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

...2014-01-01 false Surveys of ambient radiation exposure rate. 35.70 Section 35...Requirements § 35.70 Surveys of ambient radiation exposure rate. (a) In addition...chapter, a licensee shall survey with a radiation detection survey instrument at...

2014-01-01

320

38 CFR 3.715 - Radiation Exposure Compensation Act of 1990, as amended.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Radiation Exposure Compensation Act of 1990, as...Benefits and Elections § 3.715 Radiation Exposure Compensation Act of 1990, as amended. (a) Compensation. (1) A radiation-exposed veteran, as defined in...

2011-07-01

321

38 CFR 3.715 - Radiation Exposure Compensation Act of 1990, as amended.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Radiation Exposure Compensation Act of 1990, as...Benefits and Elections § 3.715 Radiation Exposure Compensation Act of 1990, as amended. (a) Compensation. (1) A radiation-exposed veteran, as defined in...

2012-07-01

322

70 years of radiation genetics: Fruit flies, mice and humans  

SciTech Connect

Radiation protection`s function is to protect society from the potential hazards that might occur through the human use of radiation, whether it be from energy production, medical uses or other sources of exposure. To do so, various scientific bodies are called upon to develop risk estimates which will provide society with adequate protection to the adverse effects of radiation, as best we can understand those adverse affects. Geneticists have the added burden, in that they must attempt to provide protection not only to the offspring of the present generation but also for all subsequent generations. While most of us have difficulty in thinking of effects that might be manifest only one or two generations into the future, some have projected potential risks for 50 to 100 generations. Here the author reviews work on fruit flies and mice, and studies of human exposures, which has provided much of the foundational information upon which geneticists can derive conclusions with regard to radiation protection questions.

Abrahamson, S.

1997-03-01

323

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

PubMed

The information for the present discussion on the uncertainties associated with estimation of radiation risks and probability of disease causation was assembled for the recently published NCRP Report No. 171 on this topic. This memorandum provides a timely overview of the topic, given that quantitative uncertainty analysis is the state of the art in health risk assessment and given its potential importance to developments in radiation protection. Over the past decade the increasing volume of epidemiology data and the supporting radiobiology findings have aided in the reduction of uncertainty in the risk estimates derived. However, it is equally apparent that there remain significant uncertainties related to dose assessment, low dose and low dose-rate extrapolation approaches (e.g. the selection of an appropriate dose and dose-rate effectiveness factor), the biological effectiveness where considerations of the health effects of high-LET and lower-energy low-LET radiations are required and the transfer of risks from a population for which health effects data are available to one for which such data are not available. The impact of radiation on human health has focused in recent years on cancer, although there has been a decided increase in the data for noncancer effects together with more reliable estimates of the risk following radiation exposure, even at relatively low doses (notably for cataracts and cardiovascular disease). New approaches for the estimation of hereditary risk have been developed with the use of human data whenever feasible, although the current estimates of heritable radiation effects still are based on mouse data because of an absence of effects in human studies. Uncertainties associated with estimation of these different types of health effects are discussed in a qualitative and semi-quantitative manner as appropriate. The way forward would seem to require additional epidemiological studies, especially studies of low dose and low dose-rate occupational and perhaps environmental exposures and for exposures to x rays and high-LET radiations used in medicine. The development of models for more reliably combining the epidemiology data with experimental laboratory animal and cellular data can enhance the overall risk assessment approach by providing biologically refined data to strengthen the estimation of effects at low doses as opposed to the sole use of mathematical models of epidemiological data that are primarily driven by medium/high doses. NASA's approach to radiation protection for astronauts, although a unique occupational group, indicates the possible applicability of estimates of risk and their uncertainty in a broader context for developing recommendations on: (1) dose limits for occupational exposure and exposure of members of the public; (2) criteria to limit exposures of workers and members of the public to radon and its short-lived decay products; and (3) the dosimetric quantity (effective dose) used in radiation protection. PMID:23803503

Preston, R Julian; Boice, John D; Brill, A Bertrand; Chakraborty, Ranajit; Conolly, Rory; Hoffman, F Owen; Hornung, Richard W; Kocher, David C; Land, Charles E; Shore, Roy E; Woloschak, Gayle E

2013-09-01

324

Looking at the other side of the coin: the search for possible biopositive cognitive effects of the exposure to 900 MHz GSM mobile phone radiofrequency radiation.  

PubMed

Although exposure to electromagnetic radiation in radiofrequency range has caused a great deal of concern globally, radiofrequency radiation has many critical applications in both telecommunication and non-communication fields. The induction of adaptive response phenomena by exposure to radiofrequency radiation as either increased resistance to a subsequent dose of ionizing radiation or resistance to a bacterial infection has been reported recently. Interestingly, the potential beneficial effects of mobile phone radiofrequency radiation are not only limited to the induction of adaptive phenomena. It has previously been indicated that the visual reaction time of university students significantly decreased after a 10 min exposure to radiofrequency radiation emitted by a mobile phone. Furthermore, it has been revealed that occupational exposures to radar radiations decreased the reaction time in radar workers. Based on these findings, it can be hypothesized that in special circumstances, these exposures might lead to a better response of humans to different hazards. Other investigators have also provided evidence that confirms the induction of RF-induced cognitive benefits. Furthermore, some recent reports have indicated that RF radiation may play a role in protecting against cognitive impairment in Alzheimer's disease. In this light, a challenging issue will arise if there are other RF-induced stimulating effects. It is also challenging to explore the potential applications of these effects. Further research may shed light on dark areas of the health effects of short and long-term human exposure to radiofrequency radiation. PMID:24843789

Mortazavi, Seyed Ali Reza; Tavakkoli-Golpayegani, Ali; Haghani, Masoud; Mortazavi, Seyed Mohammad Javad

2014-01-01

325

Looking at the other side of the coin: the search for possible biopositive cognitive effects of the exposure to 900 MHz GSM mobile phone radiofrequency radiation  

PubMed Central

Although exposure to electromagnetic radiation in radiofrequency range has caused a great deal of concern globally, radiofrequency radiation has many critical applications in both telecommunication and non-communication fields. The induction of adaptive response phenomena by exposure to radiofrequency radiation as either increased resistance to a subsequent dose of ionizing radiation or resistance to a bacterial infection has been reported recently. Interestingly, the potential beneficial effects of mobile phone radiofrequency radiation are not only limited to the induction of adaptive phenomena. It has previously been indicated that the visual reaction time of university students significantly decreased after a 10 min exposure to radiofrequency radiation emitted by a mobile phone. Furthermore, it has been revealed that occupational exposures to radar radiations decreased the reaction time in radar workers. Based on these findings, it can be hypothesized that in special circumstances, these exposures might lead to a better response of humans to different hazards. Other investigators have also provided evidence that confirms the induction of RF-induced cognitive benefits. Furthermore, some recent reports have indicated that RF radiation may play a role in protecting against cognitive impairment in Alzheimer’s disease. In this light, a challenging issue will arise if there are other RF-induced stimulating effects. It is also challenging to explore the potential applications of these effects. Further research may shed light on dark areas of the health effects of short and long-term human exposure to radiofrequency radiation. PMID:24843789

2014-01-01

326

[Human bioaging acceleration as Chernobyl radiation consequence].  

PubMed

To monitor human bioaging as a health integral index by blood plasma markers as a molar ratio for biochemically coupled monomers of intracellular lipofuscin, an intracellular polymeric aging pigment with free-radical crossed shifts, has been developed. Lipofuscin includes cell debris with catabolites of lipoperoxic cascade and lipid antioxidants. The latter were detected in the plasma samples of normal adults and children, as well as in Chernobyl clean-up workers (24-62 years old by 1990) with external total gamma-doses of 0.9-145 cSv for 4.2 years. Dynamics for bioaging markers as the molar ratio of blood levels of lipoperoxic catabolites to their antioxidants reflected normal physiologic peculiarities for the studied age periods: oxygen stress for newborns, adaptation during childhood, stability for the middle age and an increased lipoperoxidation (mainly for aging men) due to the age weakening of the antioxidant control. The ratio for the fractions of ma- lone dialdehyde (MDA), a lipoperoxic final catabolite, showed the increase of its binding by plasma proteins in proportions to calendar ages for the norm, as it is the case for lipofuscin; The graph of the age normal molar ratio of protein-bound MDA to the free one was pre-set for calibrations into the developed computer Program to calculate Relative Aging Velocities (Wrel) by bioage increments during the period of human exposure to radiation from the CAPS damage. Wrel were increasing logarithmically to the obtained doses if the total radiation exceeded 4 cSv and exceeded their normal velocities at 50 cSv 10 times or more. Slowing down of Wrel in relation to the calendar age increment was found if the sum doses were lower than 4 cSv. Levels of the studied plasma metabolites as their bioage Moles/Moles markers relative to their norms are dynamically stationary in contrast to the lipofuscin intracellular irreversible accumulation. Earlier it was shown that the decreased vitamin E and A levels with the increased lipoperoxic metabolite blood levels that indicate health consequences for the irradiated CAPS personell with related cytogenetic deviations, as well as for the adult population and children from radio-polluted regions, were restored to norms or corrected by adequate peroral therapy with bioantioxidants. PMID:25486744

2013-01-01

327

[Human bioaging acceleration as Chernobyl radiation consequence].  

PubMed

To monitor human bioaging as a health integral index by blood plasma markers as a molar ratio for biochemically coupled monomers of intracellular lipofuscin, an intracellular polymeric aging pigment with free-radical crossed shifts, has been developed. Lipofuscin includes cell debris with catabolites of lipoperoxic cascade and lipid antioxidants. The latter were detected in the plasma samples of normal adults and children, as well as in Chernobyl clean-up workers (24-62 years old by 1990) with external total gamma-doses of 0.9-145 cSv for 4.2 years. Dynamics for bioaging markers as the molar ratio of blood levels of lipoperoxic catabolites to their antioxidants reflected normal physiologic peculiarities for the studied age periods: oxygen stress for newborns, adaptation during childhood, stability for the middle age and an increased lipoperoxidation (mainly for aging men) due to the age weakening of the antioxidant control. The ratio for the fractions of ma- lone dialdehyde (MDA), a lipoperoxic final catabolite, showed the increase of its binding by plasma proteins in proportions to calendar ages for the norm, as it is the case for lipofuscin; The graph of the age normal molar ratio of protein-bound MDA to the free one was pre-set for calibrations into the developed computer Program to calculate Relative Aging Velocities (Wrel) by bioage increments during the period of human exposure to radiation from the CAPS damage. Wrel were increasing logarithmically to the obtained doses if the total radiation exceeded 4 cSv and exceeded their normal velocities at 50 cSv 10 times or more. Slowing down of Wrel in relation to the calendar age increment was found if the sum doses were lower than 4 cSv. Levels of the studied plasma metabolites as their bioage Moles/Moles markers relative to their norms are dynamically stationary in contrast to the lipofuscin intracellular irreversible accumulation. Earlier it was shown that the decreased vitamin E and A levels with the increased lipoperoxic metabolite blood levels that indicate health consequences for the irradiated CAPS personell with related cytogenetic deviations, as well as for the adult population and children from radioolluted regions, were restored to norms or corrected by adequate peroral therapy with bioantioxidants. PMID:25508875

2013-01-01

328

Conceptual framework for designing a national survey of human exposure.  

PubMed

The development and implementation of a National Human Exposure Assessment Survey requires a sound conceptual framework in order to select the population for study, the chemicals of concern, and the media and routes of exposure requiring direct and indirect measurements. A three-level conceptual model is presented within a multidimensional space that provides the basic parameters needed to be considered in the design of such a study. The axis common to all three levels is the duration of exposure. A fundamental need in a national survey is information on environmentally relevant chemicals, the biological mechanisms and health responses, the types of personal contact, the environmental concentrations, the sources, and the populations at risk. Application of the model is appropriate for exposures that can lead to acute or chronic health effects. Five chemicals are used to illustrate the need for multimedia and multiroute exposure analyses of the general population. PMID:8814779

Lioy, P J; Pellizzari, E

1995-01-01

329

HUMAN EXPOSURE MODELING FOR CUMULATIVE RISK  

EPA Science Inventory

US EPA's Office of Research and Development (ORD) has identified cumulative risk assessment as a priority research area. This is because humans and other organisms are exposed to a multitude of chemicals, physical agents, and other stressors through multiple pathways, routes, an...

330

Mitigation of Lung Injury after Accidental Exposure to Radiation  

PubMed Central

There is a serious need to develop effective mitigators against accidental radiation exposures. In radiation accidents, many people may receive nonuniform whole-body or partial-body irradiation. The lung is one of the more radiosensitive organs, demonstrating pneumonitis and fibrosis that are believed to develop at least partially because of radiation-induced chronic inflammation. Here we addressed the crucial questions of how damage to the lung can be mitigated and whether the response is affected by irradiation to the rest of the body. We examined the widely used dietary supplement genistein given at two dietary levels (750 or 3750 mg/kg) to Fischer rats irradiated with 12 Gy to the lung or 8 Gy to the lung + 4 Gy to the whole body excluding the head and tail (whole torso). We found that genistein had promising mitigating effects on oxidative damage, pneumonitis and fibrosis even at late times (36 weeks) when drug treatment was initiated 1 week after irradiation and stopped at 28 weeks postirradiation. The higher dose of genistein showed no greater beneficial effect. Combined lung and whole-torso irradiation caused more lung-related severe morbidity resulting in euthanasia of the animals than lung irradiation alone. PMID:22013884

Mahmood, J.; Jelveh, S.; Calveley, V.; Zaidi, A.; Doctrow, S. R.; Hill, R. P.

2011-01-01

331

Response of Caenorhabditis elegans to wireless devices radiation exposure.  

PubMed

Abstract Purpose: The aim of this study was to examine the impact of electromagnetic radiation, produced by GSM (Global System for Mobile communications) mobile phones, Wi-Fi (Wireless-Fidelity) routers and wireless DECT (Digital Enhanced Cordless Telecommunications) phones, on the nematode C. elegans. Materials and methods: We exposed synchronized populations, of different developmental stages, to these wireless devices at E-field levels below ICNIRP's (International Commission on Non-Ionizing Radiation Protection) guidelines for various lengths of time. WT (wild-type) and aging- or stress-sensitive mutant worms were examined for changes in growth, fertility, lifespan, chemotaxis, short-term memory, increased ROS (Reactive Oxygen Species) production and apoptosis by using fluorescent marker genes or qRT-PCR (quantitative Reverse Transcription-Polymerase Chain Reaction). Results: No statistically significant differences were found between the exposed and the sham/control animals in any of the experiments concerning lifespan, fertility, growth, memory, ROS, apoptosis or gene expression. Conclusions: The worm appears to be robust to this form of (pulsed) radiation, at least under the exposure conditions used. PMID:25488006

Fasseas, Michael K; Fragopoulou, Adamantia F; Manta, Areti K; Skouroliakou, Aikaterini; Vekrellis, Konstantinos; Margaritis, Lukas H; Syntichaki, Popi

2014-12-01

332

Radiation exposures for DOE and DOE contractor employees - 1991. Twenty-fourth annual report  

SciTech Connect

This is the 24th annual radiation exposure report published by US DOE and its predecessor agencies. This report summarizes the radiation exposures received by both employees and visitors at DOE and COE contractor facilities during 1991. Trends in radiations exposures are evaluated. The significance of the doses is addressed by comparing them to the DOE limits and by correlating the doses to health risks based on risk estimates from expert groups.

Smith, M.H.; Hui, T.E. [Pacific Northwest Lab., Richland, WA (United States); Millet, W.H.; Scholes, V.A. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

1994-11-01

333

Acute Radiation Effects Resulting from Exposure to Solar Particle Event-Like Radiation  

NASA Astrophysics Data System (ADS)

A major solar particle event (SPE) may place astronauts at significant risk for the acute radiation syndrome (ARS), which may be exacerbated when combined with other space flight stressors, such that the mission or crew health may be compromised. The National Space Biomedical Research Institute (NSBRI) Center of Acute Radiation Research (CARR) is focused on the assessment of risks of adverse biological effects related to the ARS in animal models exposed to space flight stressors combined with the types of radiation expected during an SPE. As part of this program, FDA-approved drugs that may prevent and/or mitigate ARS symptoms are being evaluated. The CARR studies are focused on the adverse biological effects resulting from exposure to the types of radiation, at the appropriate energies, doses and dose-rates, present during an SPE (and standard reference radiations, gamma rays or electrons). The ARS is a phased syndrome which often includes vomiting and fatigue. Other acute adverse biologic effects of concern are the loss of hematopoietic cells, which can result in compromised bone marrow and immune cell functions. There is also concern for skin damage from high SPE radiation doses, including burns, and resulting immune system dysfunction. Using 3 separate animal model systems (ferrets, mice and pigs), the major ARS biologic endpoints being evaluated are: 1) vomiting/retching and fatigue, 2) hematologic changes (with focus on white blood cells) and immune system changes resulting from exposure to SPE radiation with and without reduced weightbearing conditions, and 3) skin injury and related immune system functions. In all of these areas of research, statistically significant adverse health effects have been observed in animals exposed to SPE-like radiation. Countermeasures for the management of ARS symptoms are being evaluated. New research findings from the past grant year will be discussed. Acknowledgements: This research is supported by the NSBRI Center of Acute Radiation Research (CARR) grant; NSBRI is funded through NASA NCC 9-58. Recent Publications: [1]Cengel K. A. et al. (2010) Radiat Environ Biophys 49(4): 715-21. [2] Ware J. H. et al. (2010) Radiation Res 174: 325-330. [3] Davis J. G. et al. (2010) Radiation Res 173(3):353-61. [4] Sanzari J.K. et al. (2011) Radiation Res 175(5):650-6. [5] Ni H. et al. (2011) Radiation Res 175(4): 485-92. [6] Mao X. W. et al. (2011) Radiation Res 176: 187-197. [7] Maks C. J. et al. (2011) Radiation Res 176: 170-6. [8] Kennedy A. R. et al. (2011) Radiation Res 176: 62-70. [9] Sanzari J. K. et al. (2011) Int J Radiat Biol 87: 1033-8. [10] Wilson J. M. et al. (2011) Radiation Res 176(5):649-59. [11] Kennedy A. R. and Wan X. S. (2011) Advances in Space Res 48: 1460-1479. [12] Gridley D. S. et al. (2011) Int J Radiat Biol 2011 87(12): 1173-81, [13] York J. M., et al. (2012) Brain Behav Immun 26(2): 218-27,[14] Wilson J. M. et al. (2012) Advances in Space Res 49: 237-248. [15] Krigsfeld, G.S. et al. Int J Radiat Biol 2012 Feb 6 [Epub ahead of print

Kennedy, Ann; Cengel, Keith

2012-07-01

334

Exposure to the atmospheric ionizing radiation environment: studies on Icelandic and Italian civilian aviation flight personnel  

NASA Astrophysics Data System (ADS)

The largest source of data on human exposure to low dose rate radiation may be airline flight personnel, if enrolled for studies on health effects induced by the cosmic-ray-generated atmospheric ionizing radiation, whose total dose, increasing over the years, may cause delayed radiation-induced health effects, with the high-LET and highly ionizing neutron component typical of atmospheric radiation. With regards to this, the Italian civilian airline flight personnel have been studied by analyzing the atmospheric ionizing radiation exposure and associated effects. The study population includes all Italian civilian airline flight personnel, both cockpit and cabin crewmembers, whose work history records and actual flights (route, aircraft type, and date for each individual flight for each person where possible) were available. The dose calculations were performed along specific flight legs, taking into account the actual flight profiles for all different routes and the variations with time of solar and geomagnetic parameters, in order to take into account the whole atmospheric neutron spectrum. Dose values for each flight are applied to the flight history of study participants in order to estimate the individual annual and lifetime occupational radiation dose. Following the same protocols for both cohorts in terms of dose evaluation, a comparative study has been performed between the radiation exposure patterns of the Icelandic and the Italian civilian aviation flight personnel. These two populations represent two extremes within the group of worldwide airline personnel. The Icelandic crewmembers, like only in the world their Canadian colleagues, always fly over or very close to the geomagnetic pole, and are this way exposed to high doses within each flight leg, whereas the Italian crewmembers, apart from transatlantic flights, are always flying close to the geomagnetic equator or anyhow quite far from the geomagnetic pole, receiving a small dose rates for each flight. Average dose rate values for aircraft types and routes have been obtained, along with their variations with time, and the different exposure patterns have been put into evidence. The annual individual dose for each crewmember is obtained by multiplying the average dose rates by the number of block hours for aircraft type flown each year. Analysis of dose rates and cumulative doses to crewmembers in relation with different health outcomes for the two considered aircrew groups is still in progress.

de Angelis, G.; Caldora, M.; Santaquilani, M.; Scipione, R.; Verdecchia, A.; Rafnsson, V.; Hrafnkelsson, J.; Sulem, P.; Gudjonsdottir, A. J.

335

Solar UV radiation reduces the barrier function of human skin  

PubMed Central

The ubiquitous presence of solar UV radiation in human life is essential for vitamin D production but also leads to skin photoaging, damage, and malignancies. Photoaging and skin cancer have been extensively studied, but the effects of UV on the critical mechanical barrier function of the outermost layer of the epidermis, the stratum corneum (SC), are not understood. The SC is the first line of defense against environmental exposures like solar UV radiation, and its effects on UV targets within the SC and subsequent alterations in the mechanical properties and related barrier function are unclear. Alteration of the SC’s mechanical properties can lead to severe macroscopic skin damage such as chapping and cracking and associated inflammation, infection, scarring, and abnormal desquamation. Here, we show that UV exposure has dramatic effects on cell cohesion and mechanical integrity that are related to its effects on the SC’s intercellular components, including intercellular lipids and corneodesmosomes. We found that, although the keratin-controlled stiffness remained surprisingly constant with UV exposure, the intercellular strength, strain, and cohesion decreased markedly. We further show that solar UV radiation poses a double threat to skin by both increasing the biomechanical driving force for damage while simultaneously decreasing the skin’s natural ability to resist, compromising the critical barrier function of the skin. PMID:23027968

Biniek, Krysta; Levi, Kemal; Dauskardt, Reinhold H.

2012-01-01

336

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

EPA Science Inventory

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

337

Human exposure assessment: a graduate level course  

SciTech Connect

The course has been offered three times. The content and the approach to each lecture has evolved after each time it was given. This is not unexpected since the field has been undergoing major transformations, and new approaches to measurement and modeling are being applied to current problems. The most recent student evaluation, 1990, indicates a difficulty rating of just right' (70%) to difficult' (30%). Most felt the course stimulated their interest in the topic (72%) and the examinations were learning experiences as well as a grading exercise. The major need for the discipline is an adequate text book. The GRAPE program has excellent potential as an educational tool, but it needs to make more interactions and allow introduction of activities and data. The major strengths of the course are the problems provided to the students for homework. These give the student quantitative perspective on the concepts, range in values, variables, and uncertainties necessary to complete an assessment. In addition, the development of the mathematical and conceptional continuum for placing exposure assessment in the context of toxicology, environmental science, epidemiology, and clinical intervention provides a basic framework for the discipline.

Lioy, P.J. (Exposure Measurement and Assessment Division, UMDNJ-R.W. Johnson Medical School, Piscataway, NJ (United States))

1991-07-01

338

Radiation exposure and the risk of pediatric thyroid cancer.  

PubMed

It has been more than three years since the unprecedentedly massive earthquake and tsunami struck eastern Japan on March 11, 2011, and the large accident occurred at the Fukushima Daiichi Nuclear Power Plant. To investigate the influence of radiation exposure, thyroid ultrasonography has been provided preliminarily for 360,000 children who lived in Fukushima Prefecture at the time of the accident. As of September 2013, 59 children had been diagnosed with thyroid cancer by fine-needle aspiration cytology, and 34 children had been treated surgically and ultimately diagnosed with papillary thyroid cancer. Here, I would like to describe the characteristics of pediatric thyroid cancer and typical thyroid images obtained by ultrasonography. PMID:25110391

Miyakawa, Megumi

2014-07-01

339

Changes in Liver Metabolic Gene Expression after Radiation Exposure  

NASA Technical Reports Server (NTRS)

The health of the liver, especially the rate of its metabolic enzymes, determines the concentration of circulating drugs as well as the duration of their efficacy. Most pharmaceuticals are metabolized by the liver, and clinically-used medication doses are given with normal liver function in mind. A drug overdose can result in the case of a liver that is damaged and removing pharmaceuticals from the circulation at a rate slower than normal. Alternatively, if liver function is elevated and removing drugs from the system more quickly than usual, it would be as if too little drug had been given for effective treatment. Because of the importance of the liver in drug metabolism, we want to understand any effects of spaceflight on the enzymes of the liver. Exposure to cosmic radiation is one aspect of spaceflight that can be modeled in ground experiments.

Peters, C. P.; Wotring, Virginia E.

2012-01-01

340

Radiation Exposure and the Risk of Pediatric Thyroid Cancer  

PubMed Central

Abstract It has been more than three years since the unprecedentedly massive earthquake and tsunami struck eastern Japan on March 11, 2011, and the large accident occurred at the Fukushima Daiichi Nuclear Power Plant. To investigate the influence of radiation exposure, thyroid ultrasonography has been provided preliminarily for 360,000 children who lived in Fukushima Prefecture at the time of the accident. As of September 2013, 59 children had been diagnosed with thyroid cancer by fine-needle aspiration cytology, and 34 children had been treated surgically and ultimately diagnosed with papillary thyroid cancer. Here, I would like to describe the characteristics of pediatric thyroid cancer and typical thyroid images obtained by ultrasonography. PMID:25110391

Miyakawa, Megumi

2014-01-01

341

NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS): ANALYSIS OF EXPOSURE PATHWAYS AND ROUTES FOR ARSENIC AND LEAD IN EPA REGION 5  

EPA Science Inventory

The National Human Exposure Assessment Survey (NHEXAS) Phase I field study conducted in EPA Region 5 (Great Lakes Area) provides extensive exposure data on a representative sample of approximately 250 residents of the region. Associated environmental media and biomarker (blood...

342

Maximum tolerable dose for avoidance of cataract after repeated exposure to ultraviolet radiation in rats  

Microsoft Academic Search

The purpose of the present study was to determine the impact of inter-exposure interval between repeated equivalent exposures of ultraviolet radiation (UVR) on threshold accumulated dose for cataract development. Female Sprague–Dawley rats were randomly divided into 5 inter-exposure interval groups with 20 rats in each group. The inter-exposure intervals were 6h, 1, 3, 9 and 30days respectively. Each inter-exposure interval

Xiuqin Dong; Stefan Löfgren; Marcelo Ayala; Per G. Söderberg

2007-01-01

343

Acute radiation enteritis caused by dose-dependent radiation exposure in dogs: Experimental research.  

PubMed

Accidental or intended radiation exposure in mass casualty settings presents a serious and on-going threat. The development of mitigating and treating agents requires appropriate animal models. Unfortunately, the majority of research on radiation enteritis in animals has lacked specific assessments and targeted therapy. Our study showed beagle dogs, treated by intensity-modulated radiation therapy (IMRT) for abdominal irradiation, were administered single X-ray doses of 8-30?Gy. The degree of intestinal tract injury for all of the animals after radiation exposure was evaluated with regard to clinical syndrome, endoscopic findings, histological features, and intestinal function. The range of single doses (8?Gy, 10-14?Gy, and 16-30?Gy) represented the degree of injury (mild, moderate, and severe, respectively). Acute radiation enteritis included clinical syndrome with fever, vomiting, diarrhea, hemafecia, and weight loss; typical endoscopic findings included edema, bleeding, mucosal abrasions, and ulcers; and intestinal biopsy results revealed mucosal necrosis, erosion, and loss, inflammatory cell infiltration, hemorrhage, and congestion. Changes in serum diamine oxides (DAOs) and d-xylose represented intestinal barrier function and absorption function, respectively, and correlated with the extent of damage (P?radiation enteritis, thus obtaining a relatively objective evaluation of intestinal tract injury based on clinical performance and laboratory examination. The method of assessment of the degree of intestinal tract injury after abdominal irradiation could be beneficial in the development of novel and effective therapeutic strategies for acute radiation enteritis. PMID:24872437

Xu, Wenda; Chen, Jiang; Xu, Liu; Li, Hongyu; Guo, Xiaozhong

2014-12-01

344

Health impacts of large releases of radionuclides. Cytogenetic effects as quantitative indicators of radiation exposure.  

PubMed

Scoring of dicentrics in metaphase preparations of human T lymphocytes is the method of choice for estimating individual whole-body doses of radiation exposure. A quantification of partial-body exposures or non-uniform distribution of the dose is more complicated but it can be achieved by using specific mathematical approaches. For retrospective biodosimetry, conventional scoring of dicentrics is less precise because these unstable aberrations are eliminated with time post-exposure. Symmetrical translocations are not selected against during mitotic division in the haematopoietic cell reproductive centres, so the frequencies of these stable aberrations are generally assumed to remain constant even for decades. They can now be analysed precisely by fluorescence in situ hybridization using whole chromosome-specific DNA probes (chromosome painting) with an alpha-satellite DNA probe for centromere detection. Based on in vitro calibration curves established with single or multicolour paints covering 4-22% of the total human genomic DNA content, scoring of translocations has been applied for dose reconstruction in smaller groups of atomic bomb survivors and victims of the Chernobyl and Goiania radiation accidents. However, prior to routine use, the method requires further validation. Such work includes the precise evaluation of the unexpectedly high frequency of complex exchanges (> or = 3 breaks in > or = 2 chromosomes) found both at > 2 Gy doses of low linear energy transfer (LET) radiation and generally for high LET alpha-particles. Data on the long-term stability of translocations and the appearance of clonal abberrations, as well as improved measurements of the linear coefficient of standard calibration curves, are also required. PMID:9339319

Bauchinger, M

1997-01-01

345

Building human genome maps with radiation hybrids  

SciTech Connect

Genome maps are crucial tools in human genetic research, providing known landmarks for locating disease genes and frameworks for large-scale sequencing. Radiation hybrid mapping is one technique for building genome maps. In this paper, we describe the methods used to build radiation hybrid maps of the entire human genome. We present the hidden Markov model that we employ to estimate the likelihood of a map despite uncertainty about the data, and we discuss the problem of searching for maximum-likelihood maps. We describe the graph algorithms used to find sparse but reliable initial maps and our methods of extending them. Finally, we show results validating our software on simulated data, and we describe our genome-wide human radiation hybrid maps and the evidence supporting them. 29 refs., 7 figs.

Slonim, D.; Kruglyak, L.; Stein, L.; Lander, E. [MIT Center for Genome Research, Cambridge, MA (United States)

1997-12-01

346

Radiation impacts on human health: certain, fuzzy, and unknown.  

PubMed

The atomic bomb and other studies have established with certainty that moderate-to-high doses of radiation cause many types of solid cancer and leukemia. Moving down the dose range to the vicinity of 100-200 mSv, the risks become fuzzy and then unknown at low doses on the order of 10-20 mSv. Nor have low-dose experimental studies provided definitive answers: some have suggested there may be adverse biological effects in the range of 5-50 mSv, while others support a "no risk" interpretation. Epidemiologic data contain intrinsic "noise" (variation by known and unknown factors related to genetics, lifestyle, other environmental exposures, sociodemographics, diagnostic accuracy, etc.) so are generally too insensitive to provide compelling answers in the low-dose range. However, there have been recent provocative reports regarding risk from relatively low-dose occupational and medical radiation exposures that warrant careful consideration. Summaries of the largest studies with low-dose or low dose-rate radiation exposure provide suggestive evidence of risk for solid cancer and stronger evidence for leukemia risk. Recently, interest in health endpoints other than cancer also has risen sharply, in particular the degree of cardiovascular and cataract risk following doses under 1 Sv. Data regarding cardiovascular disease are limited and fuzzy, with suggestions of inconsistencies, and the risk at low doses is essentially unknown. The evidence of cataract risk after low dose-rate exposures among those conducting interventional medical radiological procedures is becoming strong. The magnitude of radiation impacts on human health requires fuller documentation, especially for low-dose or low dose-rate exposures. From the epidemiologic vantage point, this will require longer observation of existing irradiated cohorts and development of new informative cohorts, improved accuracy in dose assessments, more attention to confounding variables, and more biosamples from irradiated groups to enable translational radiobiological studies. Introduction of Radiation Impacts on Human Health (Video 2:02, http://links.lww.com/HP/A35). PMID:24378493

Shore, Roy E

2014-02-01

347

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

SciTech Connect

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

Fabrikant, J.I.

1982-04-01

348

Traditional goat husbandry may substantially contribute to human toxoplasmosis exposure  

Technology Transfer Automated Retrieval System (TEKTRAN)

Raising goats in settings that are highly contaminated with oocysts of Toxoplasma gondii may contribute significantly to human exposure to this zoonotic parasite. Increasing consumption of young goats in Romania, where goats are typically reared in backyards that are also home to cats (the definitiv...

349

DETERMINING THE ECONOMIC VALUE OF IMPROVED HUMAN EXPOSURE DATA  

EPA Science Inventory

The U.S. EPA develops and revises environmental regulations and policies to protect the environment and human health. One of the key components of the regulatory process is establishing the proposed action level, which requires high quality exposure data. In many cases, expos...

350

INTRAUTERINE EXPOSURE OF HUMANS TO PCBS (POLYCHLORINATED BIPHENYLS): NEWBORN EFFECTS  

EPA Science Inventory

The effect of low-level chronic exposure to polychlorinated biphenyls (PCBs) from consumption of Lake Michigan fish was assessed in pregnant women and their newborn offspring. Low levels of PCBs remain in the human body for some time, and caused, in this sample, decreases in birt...

351

INVESTIGATION OF HUMAN EXPOSURE TO INDOOR POLLUTANTS IN PERSONAL MICROENVIRONMENTS  

EPA Science Inventory

Funding of this cooperative agreement is from an earmark in the 2002 Approporiations Bills. Syracuse University will conduct research on the impact of micro-environments on human exposure to indoor air pollutants. Specific areas for research include: indoor pollutant source cha...

352

THE EFFECT OF CONTROLLED OZONE EXPOSURE ON HUMAN LUMPHOCYTE FUNCTION  

EPA Science Inventory

The effects of ozone (03) on cell-mediated immunity were studied in 16 human subjects exposed to 1176 micrograms/cu.m. 03 (0.6 ppm) for 2 hr in an environmentally controlled exposure chamber. Venous blood smaples were taken before and immediately after controlled air and 03 expos...

353

Total Human Exposure Risk Database and Advance Simulaiton Environment  

EPA Science Inventory

THERdbASE is no longer supported by EPA and is no longer available as download. THERdbASE is a collection of databases and models that are useful to assist in conducting assessments of human exposure to chemical pollutants, especial...

354

Estimates of Carrington-class solar particle event radiation exposures as a function of altitude in the atmosphere of Mars  

NASA Astrophysics Data System (ADS)

Radiation exposure estimates for crew members on the surface of Mars may vary widely because of the large variations in terrain altitude. The maximum altitude difference between the highest (top of Olympus Mons) and the lowest (bottom of the Hellas impact basin) points on Mars is about 32 km. In this work estimates of radiation exposures as a function of altitude, from the Hellas impact basin to Olympus Mons, are made for a solar particle event proton radiation environment comparable to the Carrington event of 1859. We assume that the proton energy distribution for this Carrington-type event is similar to that of the Band Function fit of the February 1956 event. In this work we use the HZETRN 2010 radiation transport code, originally developed at NASA Langley Research Center, and the Computerized Anatomical Male and Female human geometry models to estimate exposures for aluminum shield areal densities similar to those provided by a spacesuit, surface lander, and permanent habitat as a function of altitude in the Mars atmosphere. Comparisons of the predicted organ exposures with current NASA Permissible Exposure Limits (PELs) are made.

Townsend, L. W.; Anderson, J. A.; Adamczyk, A. M.; Werneth, C. M.

2013-08-01

355

Effects of Nuclear Cross Sections at Different Energies on Space Radiation Exposure from Galactic Cosmic Rays  

NASA Technical Reports Server (NTRS)

Space radiation from galactic cosmic rays (GCR) is a major hazard to space crews, especially in long duration human space explorations. For this reason, they will be protected by radiation shielding that fragments the GCR heavy ions. Here we investigate how sensitive the crew's radiation exposure is to nuclear fragmentation cross sections at different energies. We find that in deep space cross sections between about 0.2 and 1.2 GeV/u have the strongest effect on dose equivalent behind shielding in solar minimum GCR environments, and cross sections between about 0.6 and 1.7 GeV/u are the most important at solar maximum'. On the other hand, at the location of the International Space Station, cross sections at_higher -energies, between about 0.6 and 1.7 GeV /u at solar minimum and between about 1.7 and 3.4 GeV/u'at,solar maximum, are the most important This is. due-to the average geomagnetic cutoff for the ISS orbit. We also show the effect of uncertainties in the fragmentation cross sections on the elemental energy spectra behind shielding. These results help to focus the studies of fragmentation cross sections on the proper energy range in order to improve our predictions of crew exposures.

Li, Zi-Wei; Adams, James H., Jr.

2007-01-01

356

Effect of low level microwave radiation exposure on cognitive function and oxidative stress in rats.  

PubMed

Use of wireless communicating devices is increasing at an exponential rate in present time and is raising serious concerns about possible adverse effects of microwave (MW) radiation emitted from these devices on human health. The present study aimed to evaluate the effects of 900 MHz MW radiation exposure on cognitive function and oxidative stress in blood of Fischer rats. Animals were divided into two groups (6 animals/group): Group I (MW-exposed) and Group II (Sham-exposed). Animals were subjected to MW exposure (Frequency 900 MHz; specific absorption rate 8.4738 x 10(-5) W/kg) in Gigahertz transverse electromagnetic cell (GTEM) for 30 days (2 h/day, 5 days/week). Subsequently, cognitive function and oxidative stress parameters were examined for each group. Results showed significant impairment in cognitive function and increase in oxidative stress, as evidenced by the increase in levels of MDA (a marker of lipid peroxidation) and protein carbonyl (a marker of protein oxidation) and unaltered GSH content in blood. Thus, the study demonstrated that low level MW radiation had significant effect on cognitive function and was also capable of leading to oxidative stress. PMID:23720885

Deshmukh, Pravin Suryakantrao; Banerjee, Basu Dev; Abegaonkar, Mahesh Pandurang; Megha, Kanu; Ahmed, Rafat Sultana; Tripathi, Ashok Kumar; Mediratta, Pramod Kumari

2013-04-01

357

Los Alamos Science: Number 23, 1995. Radiation protection and the human radiation experiments  

SciTech Connect

There are a variety of myths and misconceptions about the ionizing radiation that surrounds and penetrates us all. Dispel a few of these by taking a leisurely tour of radiation and its properties, of the natural and man-made sources of ionizing radiation, and of the way doses are calculated. By damaging DNA and inducing genetic mutations, ionizing radiation can potentially initiate a cell on the road to cancer. The authors review what is currently known about regulation of cellular reproduction, DNA damage and repair, cellular defense mechanisms, and the specific cancer-causing genes that are susceptible to ionizing radiation. A rapid survey of the data on radiation effects in humans shows that high radiation doses increase the risk of cancer, whereas the effects of low doses are very difficult to detect. The hypothetical risks at low doses, which are estimated from the atomic-bomb survivors, are compared to the low-dose data so that the reader can assess the present level of uncertainty. As part of the openness initiative, ten individuals who have worked with plutonium during various periods in the Laboratory`s history were asked to share their experiences including their accidental intakes. The history and prognosis of people who have had plutonium exposures is discussed by the Laboratory`s leading epidemiologist.

Cooper, N.G. [ed.] [ed.

1995-12-31

358

Dosimetry associated with exposure to non-ionizing radiation: very low frequency to microwaves.  

PubMed

The interpretation of the effects in biological systems exposed to electromagnetic (EM) fields requires knowledge of the internal fields and absorbed energy. The quantification of the specific absorption rate (SAR) is called dosimetry. The SAR given in units of watts per kilogram is a complex function of the source configuration, shape and size of the exposed subjects, orientation of the subject with respect to the source, and the frequency. The average and maximum SAR in the exposed subject may vary over many orders of magnitude for a given exposure level. In order to relate observed biological effects in exposed laboratory animals to safe exposure levels for man, both the fields within the environment and SAR within the exposed tissues must be determined. The environmental fields and the SAR can often be determined from EM theory, but in most cases one must rely on instrumentation such as field survey meters for quantifying the exposure fields and electric field probes, thermocouples, thermistors, fiber optic probes, thermography, and calorimetry for quantifying the SAR in the tissues or equivalent models. A combination of techniques, each valid for a particular model over a particular frequency range, have been used to determine average and peak SARs in humans and animals exposed to plane wave radiation. Though it has been considerably more difficult to quantify these quantities for near field and partial-body exposure conditions, progress is continually being made in this area. PMID:3679822

Guy, A W

1987-12-01

359

Long-Term Differential Changes in Mouse Intestinal Metabolomics after ? and Heavy Ion Radiation Exposure  

PubMed Central

Tissue consequences of radiation exposure are dependent on radiation quality and high linear energy transfer (high-LET) radiation, such as heavy ions in space is known to deposit higher energy in tissues and cause greater damage than low-LET ? radiation. While radiation exposure has been linked to intestinal pathologies, there are very few studies on long-term effects of radiation, fewer involved a therapeutically relevant ? radiation dose, and none explored persistent tissue metabolomic alterations after heavy ion space radiation exposure. Using a metabolomics approach, we report long-term metabolomic markers of radiation injury and perturbation of signaling pathways linked to metabolic alterations in mice after heavy ion or ? radiation exposure. Intestinal tissues (C57BL/6J, female, 6 to 8 wks) were analyzed using ultra performance liquid chromatography coupled with electrospray quadrupole time-of-flight mass spectrometry (UPLC-QToF-MS) two months after 2 Gy ? radiation and results were compared to an equitoxic 56Fe (1.6 Gy) radiation dose. The biological relevance of the metabolites was determined using Ingenuity Pathway Analysis, immunoblots, and immunohistochemistry. Metabolic profile analysis showed radiation-type-dependent spatial separation of the groups. Decreased adenine and guanosine and increased inosine and uridine suggested perturbed nucleotide metabolism. While both the radiation types affected amino acid metabolism, the 56Fe radiation preferentially altered dipeptide metabolism. Furthermore, 56Fe radiation caused upregulation of ‘prostanoid biosynthesis’ and ‘eicosanoid signaling’, which are interlinked events related to cellular inflammation and have implications for nutrient absorption and inflammatory bowel disease during space missions and after radiotherapy. In conclusion, our data showed for the first time that metabolomics can not only be used to distinguish between heavy ion and ? radiation exposures, but also as a radiation-risk assessment tool for intestinal pathologies through identification of biomarkers persisting long after exposure. PMID:24475228

Kaur, Prabhjit; Singh, Rajbir; Fornace, Albert J.; Datta, Kamal

2014-01-01

360

Comparison of the repair of potentially lethal damage after low- and high-LET radiation exposure, assessed from the kinetics and fidelity of chromosome rejoining in normal human fibroblasts  

PubMed Central

Potentially lethal damage (PLD) and its repair (PLDR) were studied in confluent human fibroblasts by analyzing the kinetics of chromosome break rejoining after X-ray or heavy-ion exposures. Cells were either held in the non-cycling G0 phase of the cell cycle for 12 h, or forced to proliferate immediately after irradiation. Fusion premature chromosome condensation (PCC) was combined with fluorescence in situ hybridization (FISH) to study chromosomal aberrations in interphase. The culture condition had no impact on the rejoining kinetics of PCC breaks during the 12 h after X-ray or heavy-ion irradiation. However, 12 h after X-ray and silicon irradiation, cycling cells had more chromosome exchanges than non-cycling cells. After 6 Gy X-rays, the yield of exchanges in cycling cells was 2.8 times higher than that in non-cycling cells, and after 2 Gy of 55 keV/?m silicon ions the yield of exchanges in cycling cells was twice that of non-cycling cells. In contrast, after exposure to 2 Gy 200-keV/?m or 440-keV/?m iron ions the yield of exchanges was similar in non-cycling and cycling cells. Since the majority of repair in G0/G1 occurs via the non-homologous end joining process (NHEJ), increased PLDR in X-ray and silicon-ion irradiated cells may result from improved cell cycle-specific rejoining fidelity through the NHEJ pathway, which is not the case in high-LET iron-ion irradiated cells. PMID:23674607

Liu, Cuihua; Kawata, Tetsuya; Zhou, Guangming; Furusawa, Yoshiya; Kota, Ryuichi; Kumabe, Atsuhiro; Sutani, Shinya; Fukada, Junichi; Mishima, Masayo; Shigematsu, Naoyuki; George, Kerry; Cucinotta, Francis

2013-01-01

361

Human exposures to immobilising agents: results of an online survey.  

PubMed

Cases of human exposure to veterinary injectable anaesthetics were reviewed following a literature search and completion of an online questionnaire in an attempt to provide an objective approach to the problem. The modified Glasgow Coma Scale was used to rank cases according to their severity. From the cases examined, results showed that intoxication with potent opioids, such as etorphine, carfentanil and thiafentanil, need to be treated with antagonists such as naloxone, nalmefene or naltrexone, and not with antagonists with agonistic properties, such as diprenorphine. With regard to the alpha(2)-agonists xylazine, detomidine, medetomidine and romifidine, no antagonist is currently accredited for human use. Atipamezole, a specific alpha(2)-antagonist, is widely used in veterinary medicine and has been used experimentally to reverse dexmetomidine in a study in human medicine. The high concentrations of alpha(2)-agonists being used in zoo and wildlife medicine warrant the accreditation of atipamezole for use in cases of human exposure. Knowledge and availability of the appropriate antagonist are essential in cases of human intoxication with injectable anaesthetics. Preventive measures, such as wearing gloves and eye protection, need to be used more regularly to reduce the risk of exposure. PMID:20802186

Haymerle, A; Fahlman, A; Walzer, C

2010-08-28

362

Diagnostic medical imaging radiation exposure and risk of development of solid and hematologic malignancy.  

PubMed

Limiting patients' exposure to ionizing radiation during diagnostic imaging is of concern to patients and clinicians. Large single-dose exposures and cumulative exposures to ionizing radiation have been associated with solid tumors and hematologic malignancy. Although these associations have been a driving force in minimizing patients' exposure, significant risks are found when diagnoses are missed and subsequent treatment is withheld. Therefore, based on epidemiologic data obtained after nuclear and occupational exposures, dose exposure limits have been estimated. A recent collaborative effort between the US Food and Drug Administration and the American College of Radiology has provided information and tools that patients and imaging professionals can use to avoid unnecessary ionizing radiation scans and ensure use of the lowest feasible radiation dose necessary for studies. Further collaboration, research, and development should focus on producing technological advances that minimize individual study exposures and duplicate studies. This article outlines the research used to govern safe radiation doses, defines recent initiatives in decreasing radiation exposure, and provides orthopedic surgeons with techniques that may help decrease radiation exposure in their daily practice. PMID:22588399

Fabricant, Peter D; Berkes, Marschall B; Dy, Christopher J; Bogner, Eric A

2012-05-01

363

Comparative MicroRNA Expression Patterns in Fibroblasts after Low and High Doses of Low-LET Radiation Exposure  

NASA Technical Reports Server (NTRS)

Exposure to ionizing radiation causes DNA damage to cells, and provokes a plethora of cellular responses controlled by unique gene-directed signaling pathways. MicroRNAs (miRNAs) are small (22-nucleotide), non-coding RNAs which functionally silence gene expression by either degrading the messages or inhibiting translation. Here we investigate radiation-dependent changes in these negative regulators by comparing the expression patterns of all 462 known human miRNAs in fibroblasts, after exposure to low (0.1 Gy) or high (2 Gy) doses of X-rays at 30 min, 2, 6 and 24 hrs post-treatment. The expression patterns of microRNAs after low and high doses of radiation show a similar qualitative down-regulation trend at early (0.5 hr) and late (24 hr) time points, with a quantitatively steeper slope following the 2 Gy exposures. Interestingly, an interruption of this downward trend is observed after the 2 Gy exposure, i.e. a significant up-regulation of microRNAs at 2 hrs, then reverting to the downward trend by 6 hrs; this interruption at the intermediate time point was not observed with the 0.1 Gy exposure. At the early time point (0.5 hr), candidate gene targets of selected down-regulated microRNAs, common to both 0.1 and 2 Gy exposures, were those functioning in chromatin remodeling. Candidate target genes of unique up-regulated microRNAs seen at a 2 hr intermediate time point, after the 2 Gy exposure only, are those involved in cell death signaling. Finally, putative target genes of down-regulated microRNAs seen at the late (24 hr) time point after either doses of radiation are those involved in the up-regulation of DNA repair, cell signaling and homeostasis. Thus we hypothesize that after radiation exposure, microRNAs acting as hub negative regulators for unique signaling pathways needed to be down-regulated so as to de-repress their target genes for the proper cellular responses, including DNA repair and cell maintenance. The unique microRNAs up-regulated at 2 hr after 2 Gy suggest the cellular response to functionally suppress the apoptotic death signaling reflex after exposure to high dose radiation. Further analyses with transcriptome and global proteomic profiling will validate the reciprocal expression of signature microRNAs selected in our radiation-exposed cells, and their candidate target gene families, and test our hypothesis that unique radiation-specific microRNAs are keys in governing signaling responses for damage control of this environmental hazard.

Maes, Olivier C.; Xu, Suying; Hada, Megumi; Wu, Honglu; Wang, Eugenia

2007-01-01

364

Chronic myelogenous leukemia and exposure to ionizing radiation — a retrospective study of 443 patients  

Microsoft Academic Search

Exposure to ionizing radiations (Rx) has been implicated as a causative factor of chronic myelogenous leukemia (CML). We performed a retrospective study of 443 consecutive CML patients, looking for a history of significant exposure to Rx, and evaluated the clinical and hematological characteristics in order to find any difference between radiation-related CML patients and those with de novo CML. We

A. Corso; M. Lazzarino; E. Morra; S. Merante; C. Astori; P. Bernasconi; M. Boni; C. Bernasconi

1995-01-01

365

10 CFR 35.2070 - Records of surveys for ambient radiation exposure rate.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Records of surveys for ambient radiation exposure rate. 35.2070 Section 35.2070 Energy...MATERIAL Records § 35.2070 Records of surveys for ambient radiation exposure rate. A licensee shall retain a record of...

2010-01-01

366

10 CFR 35.2070 - Records of surveys for ambient radiation exposure rate.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 false Records of surveys for ambient radiation exposure rate. 35.2070 Section 35.2070 Energy...MATERIAL Records § 35.2070 Records of surveys for ambient radiation exposure rate. A licensee shall retain a record of...

2011-01-01

367

10 CFR 35.2070 - Records of surveys for ambient radiation exposure rate.  

... 2014-01-01 false Records of surveys for ambient radiation exposure rate. 35.2070 Section 35.2070 Energy...MATERIAL Records § 35.2070 Records of surveys for ambient radiation exposure rate. A licensee shall retain a record of...

2014-01-01

368

10 CFR 35.2070 - Records of surveys for ambient radiation exposure rate.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 false Records of surveys for ambient radiation exposure rate. 35.2070 Section 35.2070 Energy...MATERIAL Records § 35.2070 Records of surveys for ambient radiation exposure rate. A licensee shall retain a record of...

2012-01-01

369

10 CFR 35.2070 - Records of surveys for ambient radiation exposure rate.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 false Records of surveys for ambient radiation exposure rate. 35.2070 Section 35.2070 Energy...MATERIAL Records § 35.2070 Records of surveys for ambient radiation exposure rate. A licensee shall retain a record of...

2013-01-01

370

Body radiation exposure in breast cancer radiotherapy: Impact of breast IMRT and virtual wedge compensation techniques  

Microsoft Academic Search

Purpose: Recent reports demonstrate a dramatically increased rate of secondary leukemia for breast cancer patients receiving adjuvant high-dose anthracycline and radiotherapy, and that radiation is an independent factor for the development of leukemia. This study aimed to evaluate the radiation body exposure during breast radiotherapy and to characterize the factors associated with an increased exposure. Patients and Methods: In a

Tony Woo; Jean-Philippe. Pignol; Eileen Rakovitch; Toni Vu; Deanna Hicks; Peter OBrien; Kathleen Pritchard

2006-01-01

371

78 FR 79009 - Proposed Information Collection; Radiation Sampling and Exposure Records (Pertains to Underground...  

Federal Register 2010, 2011, 2012, 2013

...Proposed Information Collection; Radiation Sampling and Exposure Records (Pertains to Underground...information collection for updating Radiation Sampling and Exposure Records. DATES: All comments...procedures to be used by the mine operator in sampling mine air for the presence and...

2013-12-27

372

75 FR 79033 - Proposed Extension of Existing Information Collection; Radiation Sampling and Exposure Records...  

Federal Register 2010, 2011, 2012, 2013

...Existing Information Collection; Radiation Sampling and Exposure Records (Pertains to Underground...information collection for Radiation Sampling and Exposure Records, 30 CFR 57.5037...procedures to be used by the mine operator in sampling mine air for the presence and...

2010-12-17

373

75 FR 80072 - Proposed Extension of Existing Information Collection; Radiation Sampling and Exposure Records  

Federal Register 2010, 2011, 2012, 2013

...Existing Information Collection; Radiation Sampling and Exposure Records AGENCY: Mine Safety...information collection for Radiation Sampling and Exposure Records, 30 CFR 57.5037...procedures to be used by the mine operator in sampling mine air for the presence and...

2010-12-21

374

Assessing sources of human methylmercury exposure using stable mercury isotopes.  

PubMed

Seafood consumption is the primary route of methylmercury (MeHg) exposure for most populations. Inherent uncertainties in dietary survey data point to the need for an empirical tool to confirm exposure sources. We therefore explore the utility of Hg stable isotope ratios in human hair as a new method for discerning MeHg exposure sources. We characterized Hg isotope fractionation between humans and their diets using hair samples from Faroese whalers exposed to MeHg predominantly from pilot whales. We observed an increase of 1.75‰ in ?(202)Hg values between pilot whale muscle tissue and Faroese whalers' hair but no mass-independent fractionation. We found a similar offset in ?(202)Hg between consumed seafood and hair samples from Gulf of Mexico recreational anglers who are exposed to lower levels of MeHg from a variety of seafood sources. An isotope mixing model was used to estimate individual MeHg exposure sources and confirmed that both ?(199)Hg and ?(202)Hg values in human hair can help identify dietary MeHg sources. Variability in isotopic signatures among coastal fish consumers in the Gulf of Mexico likely reflects both differences in environmental sources of MeHg to coastal fish and uncertainty in dietary recall data. Additional data are needed to fully refine this approach for individuals with complex seafood consumption patterns. PMID:24967674

Li, Miling; Sherman, Laura S; Blum, Joel D; Grandjean, Philippe; Mikkelsen, Bjarni; Weihe, Pál; Sunderland, Elsie M; Shine, James P

2014-08-01

375

Animals as sentinels for human lead exposure: a case report.  

PubMed

Because human and nonhuman animals often share the same environment, there is potential concurrent exposure to toxicants. As a result, domestic animals can be used as sentinels for exposure of people to these agents. Here we present a case illustrating exposure of both humans and domestic animals to lead contamination in their environments. This case study occurred at a farm where cattle deaths were determined to have been caused by lead poisoning based on elevated postmortem tissue lead concentrations. Elevated blood lead concentrations were detected in the remaining cattle, a dog, a cat, and a pregnant woman (37.3 ?g/dL) living on the farm. The range of blood lead concentrations in the domestic animals was 8.42 (cat) to 85.41 ?g/dL (calf), although clinical signs of lead poisoning were not apparent in these animals. Further testing revealed the most likely source for lead exposure to be paint in the barn and home. Household dogs and cats have been used as sentinels for lead poisoning in humans, but cattle may also act as a sentinel species for environmental lead contamination. PMID:20238198

Bischoff, Karyn; Priest, Heather; Mount-Long, Amy

2010-06-01

376

Effects of exposure to different types of radiation on behaviors mediated by peripheral or central systems  

NASA Astrophysics Data System (ADS)

The effects of exposure to ionizing radiation on behavior may result from effects on peripheral or on central systems. For behavioral endpoints that are mediated by peripheral systems (e.g., radiation-induced conditioned taste aversion or vomiting), the behavioral effects of exposure to heavy particles (^56Fe, 600 MeV/n) are qualitatively similar to the effects of exposure to gamma radiation (^60Co) and to fission spectrum neutrons. For these endpoints, the only differences between the different types of radiation are in terms of relative behavioral effectiveness. For behavioral endpoints that are mediated by central systems (e.g., amphetamine-induced taste aversion learning), the effects of exposure to ^56Fe particles are not seen following exposure to lower LET gamma rays or fission spectrum neutrons. These results indicate that the effects of exposure to heavy particles on behavioral endpoints cannot necessarily be extrapolated from studies using gamma rays, but require the use of heavy particles.

Rabin, B. M.; Joseph, J. A.; Erat, S.

377

Effects of exposure to different types of radiation on behaviors mediated by peripheral or central systems  

NASA Technical Reports Server (NTRS)

The effects of exposure to ionizing radiation on behavior may result from effects on peripheral or on central systems. For behavioral endpoints that are mediated by peripheral systems (e.g., radiation-induced conditioned taste aversion or vomiting), the behavioral effects of exposure to heavy particles (56Fe, 600 MeV/n) are qualitatively similar to the effects of exposure to gamma radiation (60Co) and to fission spectrum neutrons. For these endpoints, the only differences between the different types of radiation are in terms of relative behavioral effectiveness. For behavioral endpoints that are mediated by central systems (e.g., amphetamine-induced taste aversion learning), the effects of exposure to 56Fe particles are not seen following exposure to lower LET gamma rays or fission spectrum neutrons. These results indicate that the effects of exposure to heavy particles on behavioral endpoints cannot necessarily be extrapolated from studies using gamma rays, but require the use of heavy particles.

Rabin, B. M.; Joseph, J. A.; Erat, S.

1998-01-01

378

EXPOSURE ASSESSMENT OF NON-IONISING RADIATION FROM 5 HZ TO 3 GHZ  

Microsoft Academic Search

The paper describes the assessment of the exposure to non-ionising electromagnetic radiation at today's office workplaces. The measured exposure values are compared with the exposure limits defined for the general public. The here presented method, which uses general purpose LF- and RF-test instrumentation, is applied to a limited sample of workplaces. So far, 14 workplaces at 5 different locations have

379

[Manganese in drinking water and its contribution to human exposure].  

PubMed

Methylcyclopentadienyl manganese tricarbonyl (MMT) has been used in Canada since 1976 as an additive in unleaded gasoline. The combustion of MMT leads to the emission of Mn oxides to the environment and may represent a potential risk to public health. It therefore seems important to assess the associated Mn exposure. The present study is part of a broader research program on total human exposure to Mn and aims specifically at assessing the level of exposure to Mn and other metals via drinking water. A comparative study was performed between two groups of workers (garage mechanics and blue collar workers of the University of Montreal) differentiated by their exposure to inhaled Mn. For Pb, Cu and Zn in residential tap water, significant differences were observed between the first sample and the one taken after one minute of flow. A significant difference was also found between the two groups of workers (combined flow time) for Mn, Cu and Ca. The Mn contribution from water is estimated to be 1% of the total dose from ingested food. This low exposure may become important (17%) for persons drinking well water, especially if we consider interactions between metals following multimedia exposure. PMID:8085048

Loranger, S; Bibeau, M C; Zayed, J

1994-01-01

380

Naphthalene distributions and human exposure in Southern California  

NASA Astrophysics Data System (ADS)

The regional distribution of, and human exposure to, naphthalene are investigated for Southern California. A comprehensive approach is taken in which advanced models are linked for the first time to quantify population exposure to the emissions of naphthalene throughout Southern California. Naphthalene is the simplest and most abundant of the polycyclic aromatic hydrocarbons found in polluted urban environments, and has been detected in both outdoor and indoor air samples. Exposure to high concentrations of naphthalene may have adverse health effects, possibly causing cancer in humans. Among the significant emission sources are volatilization from naphthalene-containing products, petroleum refining, and combustion of fossil fuels and wood. Gasoline and diesel engine exhaust, with related vaporization from fuels, are found to contribute roughly half of the daily total naphthalene burden in Southern California. As part of this study, the emission inventory for naphthalene has been verified against new field measurements of the naphthalene-to-benzene ratio in a busy traffic tunnel in Los Angeles, supporting the modeling work carried out here. The Surface Meteorology and Ozone Generation (SMOG) airshed model is used to compute the spatial and temporal distributions of naphthalene and its photooxidation products in Southern California. The present simulations reveal a high degree of spatial variability in the concentrations of naphthalene-related species, with large diurnal and seasonal variations as well. Peak naphthalene concentrations are estimated to occur in the early morning hours in the winter season. The naphthalene concentration estimates obtained from the SMOG model are employed in the Regional Human Exposure (REHEX) model to calculate population exposure statistics. Results show average hourly naphthalene exposures in Southern California under summer and winter conditions of 270 and 430 ng m -3, respectively. Exposure to significantly higher concentrations may occur for individuals close to local sources, or in naphthalene "hotspots" revealed by simulations and observations. Such levels of naphthalene exposure may be used to gauge the potential health impacts of long-term naphthalene exposure. Results are also given for the distributions of 1,4-naphthoquinone, a naphthalene reaction product that may have significant health effects.

Lu, Rong; Wu, Jun; Turco, Richard P.; Winer, Arthur M.; Atkinson, Roger; Arey, Janet; Paulson, Suzanne E.; Lurmann, Fred W.; Miguel, Antonio H.; Eiguren-Fernandez, Arantzazu

381

Monitoring exposure to atomic bomb radiation by somatic mutation  

SciTech Connect

Atomic bomb survivors are a population suitable for studying the relationship between somatic mutation and cancer risk because their exposure doses are relatively well known and their dose responses in terms of cancer risk have also been thoroughly studied. An analysis has been made of erythrocyte glycophorin A (GPA) gene mutations in 1,226 atomic bomb survivors in Hiroshima and Nagasaki. The GPA mutation frequency (Mf) increased slightly but significantly with age at the time of measurement and with the number of cigarettes smoked. After adjustment for the effect of smoking, the Mf was significantly higher in males than in females and higher in Hiroshima than in Nagasaki. All of these characteristics of the background GPA Mf were in accord with those of solid tumor incidence obtained from an earlier epidemiological study of A-bomb survivors. Analysis of the dose effect on Mf revealed the doubling dose to be about 1.20 Sv and the minimum dose for detection of a significant increase to be about 0.24 Sv. No significant dose effect for difference in sex, city, or age at the time of bombing was observed. Interestingly, the doubling dose for the GPA Mf approximated that for solid cancer incidence (1.59 Sv). And the minimum dose for detection was not inconsistent with the data for solid cancer incidence. The dose effect was significantly higher in those diagnosed with cancer before or after measurement than in those without a history of cancer. These findings are consistent with the hypothesis that somatic mutations are the main cause of excess cancer risk from radiation exposure. 27 refs., 2 figs.

Akiyama, Mitoshi; Kyoizumi, Seishi; Kusunoki, Yoichiro [Radiation Effects Research Foundation, Hiroshima (Japan)] [and others

1996-05-01

382

Monitoring exposure to atomic bomb radiation by somatic mutation.  

PubMed

Atomic bomb survivors are a population suitable for studying the relationship between somatic mutation and cancer risk because their exposure doses are relatively well known and their dose responses in terms of cancer risk have also been thoroughly studied. An analysis has been made of erythrocyte glycophorin A (GPA) gene mutations in 1,226 atomic bomb survivors in Hiroshima and Nagasaki. The GPA mutation frequency (Mf) increased slightly but significantly with age at the time of measurement and with the number of cigarettes smoked. After adjustment for the effect of smoking, the Mf was significantly higher in males than in females and higher in Hiroshima than in Nagasaki. All of these characteristics of the background GPA Mf were in accord with those of solid tumor incidence obtained from an earlier epidemiological study of A-bomb survivors. Analysis of the dose effect on Mf revealed the doubling dose to be about 1.20 Sv and the minimum dose for detection of a significant increase to be about 0.24 Sv. No significant dose effect for difference in sex, city, or age at the time of bombing was observed. Interestingly, the doubling dose for the GPA Mf approximated that for solid cancer incidence (1.59 Sv). And the minimum dose for detection was not inconsistent with the data for solid cancer incidence. The dose effect was significantly higher in those diagnosed with cancer before or after measurement than in those without a history of cancer. These findings are consistent with the hypothesis that somatic mutations are the main cause of excess cancer risk from radiation exposure. PMID:8781371

Akiyama, M; Kyoizumi, S; Kusunoki, Y; Hirai, Y; Tanabe, K; Cologne, J B

1996-05-01

383

Diagnostic Ionizing Radiation Exposure in a Population-Based Sample of Children With Inflammatory Bowel Diseases  

Microsoft Academic Search

OBJECTIVES:The degree of diagnostic radiation exposure in children with inflammatory bowel diseases (IBD) is largely unknown. In this study, we describe this exposure in a population-based sample of children with IBD and determine the characteristics associated with moderate radiation exposure.METHODS:We ascertained radiological study use, demographic characteristics, IBD medication use, and the requirement for hospitalization, emergency department (ED) encounter, or inpatient

Lena Palmer; Hans Herfarth; Carol Q Porter; Lynn A Fordham; Robert S Sandler; Michael D Kappelman

2009-01-01

384

Radiation risk and human space exploration  

NASA Technical Reports Server (NTRS)

Radiation protection is essential to enable humans to live and work safely in space. Predictions about the nature and magnitude of the risks posed by space radiation are subject to very large uncertainties. Prudent use of worst-case scenarios may impose unacceptable constraints on shielding mass for spacecraft or habitats, tours of duty of crews on Space Station, and on the radius and duration of sorties on planetary surfaces. The NASA Space Radiation Health Program has been devised to develop the knowledge required to accurately predict and to efficiently manage radiation risk. The knowledge will be acquired by means of a peer-reviewed, largely ground-based and investigator-initiated, basic science research program. The NASA Strategic Plan to accomplish these objectives in a manner consistent with the high priority assigned to the protection and health maintenance of crews will be presented. Published by Elsevier Science Ltd on behalf of COSPAR.

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

2003-01-01

385

Radiation Exposure, the ATM Gene, and Contralateral Breast Cancer in the Women's Environmental Cancer and Radiation Epidemiology Study  

PubMed Central

Background Ionizing radiation is a known mutagen and an established breast carcinogen. The ATM gene is a key regulator of cellular responses to the DNA damage induced by ionizing radiation. We investigated whether genetic variants in ATM play a clinically significant role in radiation-induced contralateral breast cancer in women. Methods The Women's Environmental, Cancer, and Radiation Epidemiology Study is an international population-based case–control study nested within a cohort of 52?536 survivors of unilateral breast cancer diagnosed between 1985 and 2000. The 708 case subjects were women with contralateral breast cancer, and the 1397 control subjects were women with unilateral breast cancer matched to the case subjects on age, follow-up time, registry reporting region, and race and/or ethnicity. All women were interviewed and underwent full mutation screening of the entire ATM gene. Complete medical treatment history information was collected, and for all women who received radiotherapy, the radiation dose to the contralateral breast was reconstructed using radiotherapy records and radiation measurements. Rate ratios (RRs) and corresponding 95% confidence intervals (CIs) were estimated by using multivariable conditional logistic regression. All P values are two-sided. Results Among women who carried a rare ATM missense variant (ie, one carried by <1% of the study participants) that was predicted to be deleterious, those who were exposed to radiation (mean radiation exposure = 1.2 Gy, SD = 0.7) had a statistically significantly higher risk of contralateral breast cancer compared with unexposed women who carried the wild-type genotype (0.01–0.99 Gy: RR = 2.8, 95% CI = 1.2 to 6.5; ?1.0 Gy: RR = 3.3, 95% CI = 1.4 to 8.0) or compared with unexposed women who carried the same predicted deleterious missense variant (0.01–0.99 Gy: RR = 5.3, 95% CI = 1.6 to 17.3; ?1.0 Gy: RR = 5.8, 95% CI = 1.8 to 19.0; Ptrend = .044). Conclusions Women who carry rare deleterious ATM missense variants and who are treated with radiation may have an elevated risk of developing contralateral breast cancer. However, the rarity of these deleterious missense variants in human populations implies that ATM mutations could account for only a small portion of second primary breast cancers. PMID:20305132

Haile, Robert W.; Stovall, Marilyn; Boice, John D.; Shore, Roy E.; Langholz, Bryan; Thomas, Duncan C.; Lynch, Charles F.; Olsen, Jorgen H.; Malone, Kathleen E.; Mellemkjaer, Lene; Borresen-Dale, Anne-Lise; Rosenstein, Barry S.; Teraoka, Sharon N.; Diep, Anh T.; Smith, Susan A.; Capanu, Marinela; Reiner, Anne S.; Liang, Xiaolin; Gatti, Richard A.; Concannon, Patrick

2010-01-01

386

Carcinogenesis--a synopsis of human experience with external exposure in medicine  

SciTech Connect

Studies in the 1980s of medically irradiated populations have increased our knowledge of radiation carcinogenesis. (1) Investigations of prenatal x-ray exposures, especially in twins, provide evidence that very low doses of ionizing radiation may cause cancer in humans. (2) Fractionated doses appear as effective as single exposures of the same total dose in causing breast cancer, but seem less effective for lung cancer. (3) Excess breast cancers can occur among women exposed under age 10, indicating that the immature breast is susceptible to the carcinogenic action of radiation. (4) Moderate doses on the order of 1 Gy to the brains of children can cause tumors later in life; moderately high doses to the skin can cause cancer when followed by frequent exposure to ultraviolet light. (5) Radiotherapy for cervical cancer can increase the rate of subsequent leukemia with the best fitting dose-response functions including a negative exponential term to account for cell-killing. (6) Low-dose exposures of about 10 cGy may increase the risk of thyroid cancer. (7) Second cancers following radiotherapy for a variety of cancers occur primarily among long-term survivors. (8) Radiotherapy may not significantly increase the risk of leukemia following childhood cancer, whereas chemotherapy with alkylating agents is a major risk factor. (9) Bone cancer occurs after high-dose radiotherapy for childhood cancer, but children with retinoblastoma are not more susceptible to radiation-induced disease than children with other malignancies. (10) High-dose external beam therapy can cause thyroid cancer. (11) Studies of cervical cancer patients indicate that the risk of radiation-induced second malignancies follows a time-response model consistent with a constant multiplication of the underlying background incidence. 83 references.

Boice, J.D. Jr.

1988-10-01

387

Human exposure to radiofrequency electromagnetic fields. Final rule.  

PubMed

This document resolves several issues regarding compliance with the Federal Communications Commission's (FCC's) regulations for conducting environmental reviews under the National Environmental Policy Act (NEPA) as they relate to the guidelines for human exposure to RF electromagnetic fields. More specifically, the Commission clarifies evaluation procedures and references to determine compliance with its limits, including specific absorption rate (SAR) as a primary metric for compliance, consideration of the pinna (outer ear) as an extremity, and measurement of medical implant exposure. The Commission also elaborates on mitigation procedures to ensure compliances with its limits, including labeling and other requirements for occupational exposure classification, clarification of compliance responsibility at multiple transmitter sites, and labeling of fixed consumer transmitters. PMID:23734401

2013-06-01

388

Correction of aftereffects of ionizing radiation by exposure to low-intensity light.  

PubMed

Specific features of free radical oxidation were studied after experimental exposure to ionizing radiation. A decrease in the level of products of oxidative modification of proteins and LPO was observed after exposure of irradiated zone to low-intensity incoherent red light. It was suggested that low-intensity radiation of this spectrum produces a radioprotective effect and can be used for the correction of ionizing radiation-induced disturbances. PMID:24770753

Bavrina, A P; Monich, V A; Malinovskaya, S L; Ermolaev, V S; Druzhinin, E A; Kuznetsov, S S

2014-03-01

389

Radiation exposure from work-related medical X-rays at the Portsmouth Naval Shipyard  

Microsoft Academic Search

Background Previous analyses suggest that worker radiation dose may be significantly increased by routine occupational X-ray examinations. Medical exposures are investigated for 570 civilian workers employed at the Portsmouth Naval Shipyard (PNS) at Kittery, Maine. The research objective was to determine the radiation exposure contri- bution of work-related chest X-rays (WRX) relative to conventional workplace radiation sources. Methods Methods were

Robert D. Daniels; Travis L. Kubale; Henry B. Spitz

2005-01-01

390

Non-Linear Adaptive Phenomena Which Decrease The Risk of Infection After Pre-Exposure to Radiofrequency Radiation  

PubMed Central

Substantial evidence indicates that adaptive response induced by low doses of ionizing radiation can result in resistance to the damage caused by a subsequently high-dose radiation or cause cross-resistance to other non-radiation stressors. Adaptive response contradicts the linear-non-threshold (LNT) dose-response model for ionizing radiation. We have previously reported that exposure of laboratory animals to radiofrequency radiation can induce a survival adaptive response. Furthermore, we have indicated that pre-exposure of mice to radiofrequency radiation emitted by a GSM mobile phone increased their resistance to a subsequent Escherichia coli infection. In this study, the survival rates in animals receiving both adapting (radiofrequency) and challenge dose (bacteria) and the animals receiving only the challenge dose (bacteria) were 56% and 20%, respectively. In this light, our findings contribute to the assumption that radiofrequency-induced adaptive response can be used as an efficient method for decreasing the risk of infection in immunosuppressed irradiated individuals. The implication of this phenomenon in human’s long term stay in the space is also discussed. PMID:24910582

Mortazavi, S.M.J.; Motamedifar, M.; Namdari, G.; Taheri, M.; Mortazavi, A.R.; Shokrpour, N.

2014-01-01

391

Case Report: Human Exposure to Dioxins from Clay  

PubMed Central

Context For the general population, the dominant source of exposure to dioxin-like compounds is food. As part of the University of Michigan Dioxin Exposure Study (UMDES), we measured selected polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) in serum of 946 subjects who were a representative sample of the general population in five Michigan counties. Case presentation The total toxic equivalency (TEQ; based on 2005 World Health Organization toxic equivalency factors) of serum from the index case was 211 ppt on a lipid-adjusted basis, which was the highest value observed in the UMDES study population. This subject had no apparent opportunity for exposure to dioxins, except that she had lived on property with soil contaminated with dioxins for almost 30 years, and had been a ceramics hobbyist for > 30 years. Soil from her property and clay that she used for ceramics were both contaminated with dioxins, but the congener patterns differed. Discussion The congener patterns in this subject’s serum, soil, and ceramic clay suggest strongly that the dioxin contamination in clay and not soil was the dominant source of dioxin contamination in her serum. Relevance to public health practice: It appears that ceramic clay, in particular the process of firing clay with unvented kilns, can be a significant nonfood and nonindustrial source of human exposure to dioxins among ceramics hobbyists. The extent of human exposure from ceramic clay is unclear, but it may be widespread. Further work is needed to more precisely characterize the routes of exposure. PMID:18288324

Franzblau, Alfred; Hedgeman, Elizabeth; Chen, Qixuan; Lee, Shih-Yuan; Adriaens, Peter; Demond, Avery; Garabrant, David; Gillespie, Brenda; Hong, Biling; Jolliet, Olivier; Lepkowski, James; Luksemburg, William; Maier, Martha; Wenger, Yvan

2008-01-01

392

Human Biodistribution and Radiation Dosimetry of 82Rb  

PubMed Central

Prior estimates of radiation-absorbed doses from 82Rb, a frequently used PET perfusion tracer, yielded discrepant results. We reevaluated 82Rb dosimetry using human in vivo biokinetic measurements. Methods Ten healthy volunteers underwent dynamic PET/CT (6 contiguous table positions, each with separate 82Rb infusion). Source organ volumes of interest were delineated on the CT images and transferred to the PET images to obtain time-integrated activity coefficients. Radiation doses were estimated using OLINDA/EXM 1.0. Results The highest mean absorbed organ doses (?Gy/MBq) were observed for the kidneys (5.81), heart wall (3.86), and lungs (2.96). Mean effective doses were 1.11 ± 0.22 and 1.26 ± 0.20 ?Sv/MBq using the tissue-weighting factors of the International Commission on Radiological Protection (ICRP), publications 60 and 103, respectively. Conclusion Our current 82Rb dosimetry suggests reasonably low radiation exposure. On the basis of this study, a clinical 82Rb injection of 2 × 1,480 MBq (80 mCi) would result in a mean effective dose of 3.7 mSv using the weighting factors of the ICRP 103—only slightly above the average annual natural background exposure in the United States (3.1 mSv). PMID:20847168

Senthamizhchelvan, Srinivasan; Bravo, Paco E.; Esaias, Caroline; Lodge, Martin A.; Merrill, Jennifer; Hobbs, Robert F.; Sgouros, George; Bengel, Frank M.

2011-01-01

393

Protection of the gametes embryo/fetus from prenatal radiation exposure.  

PubMed

There is no convincing evidence of germline mutation manifest as heritable disease in the offspring of humans attributable to ionizing radiation, yet radiation clearly induces mutations in microbes and somatic cells of rodents and humans. Doses to the embryo estimated to be in the range of 0.15-0.2 Gy during the pre-implantation and pre-somite stages may increase the risk of embryonic loss. However, an increased risk of congenital malformations or growth retardation has not been observed in the surviving embryos. These results are primarily derived from mammalian animal studies and are referred to as the "all-or-none phenomenon." The tissue reaction effects of ionizing radiation (previously referred to as deterministic effects) are congenital malformations, mental retardation, decreased intelligence quotient, microcephaly, neurobehavioral effects, convulsive disorders, growth retardation (height and weight), and embryonic and fetal death (miscarriage, stillbirth). All these effects are consistent with having a threshold dose below which there is no increased risk. The risk of cancer in offspring that have been exposed to diagnostic x-ray procedures while in utero has been debated for 55 y. High doses to the embryo or fetus (e.g., >0.5 Gy) increase the risk of cancer. Most pregnant women exposed to x-ray procedures and other forms of ionizing radiation today received doses to the embryo or fetus <0.1 Gy. The risk of cancer in offspring exposed in utero at exposures <0.1 Gy is controversial and has not been fully resolved. Diagnostic imaging procedures using ionizing radiation that are clinically indicated for the pregnant patient and her fetus should be performed because the clinical benefits outweigh the potential oncogenic risks. PMID:25551507

Brent, Robert L

2015-02-01

394

40 CFR 158.250 - Experimental use permit data requirements for human exposure.  

Code of Federal Regulations, 2010 CFR

...permit data requirements for human exposure. 158.250 Section 158.250...PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR...permit data requirements for human exposure. No data for applicator...

2010-07-01

395

40 CFR 158.250 - Experimental use permit data requirements for human exposure.  

Code of Federal Regulations, 2012 CFR

...permit data requirements for human exposure. 158.250 Section 158.250...PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR...permit data requirements for human exposure. No data for applicator...

2012-07-01

396

40 CFR 158.250 - Experimental use permit data requirements for human exposure.  

...permit data requirements for human exposure. 158.250 Section 158.250...PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR...permit data requirements for human exposure. No data for applicator...

2014-07-01

397

40 CFR 158.250 - Experimental use permit data requirements for human exposure.  

Code of Federal Regulations, 2011 CFR

...permit data requirements for human exposure. 158.250 Section 158.250...PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR...permit data requirements for human exposure. No data for applicator...

2011-07-01

398

40 CFR 158.250 - Experimental use permit data requirements for human exposure.  

Code of Federal Regulations, 2013 CFR

...permit data requirements for human exposure. 158.250 Section 158.250...PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR...permit data requirements for human exposure. No data for applicator...

2013-07-01

399

Cumulative medical radiation exposure throughout staged palliation of single ventricle congenital heart disease.  

PubMed

Patients with single ventricle heart disease undergoing staged palliation are exposed to ionizing radiation from multiple medical sources. We sought to quantify typical radiation burden in this population and identify risk factors for increased exposure. A retrospective review was performed of single ventricle patients surgically palliated at our institution, in which all studies utilizing ionizing radiation occurring from birth through Fontan completion were compiled. Thirty-eight patients were followed for a median of 33 months. A median of 59 radiation events occurred during follow-up, with a median cumulative effective dose of 25.7 milliSieverts (mSv). On average, cardiac catheterization accounted for 4 % of radiation encounters but comprised 78 % of total radiation exposure. In a multivariate model, factors associated with increased total radiation exposure included pulmonary artery (PA) stenosis requiring intervention (p = 0.005) and systemic right ventricle (p = 0.02). Risk factors for increased exposure from catheterization included heterotaxy syndrome (p = 0.007), re-coarctation (p = 0.003), and PA stenosis (p = 0.02). At our institution, many single ventricle patients are exposed to substantial radiation throughout staged palliation, most of which derives from cardiac catheterization. PA stenosis was identified as a risk factor for increased total and catheterization-based exposure. As patient survival improves, awareness of this scale of radiation exposure at a vulnerable period is imperative. PMID:25096904

Downing, Tacy E; McDonnell, Alicia; Zhu, Xiaowei; Dori, Yoav; Gillespie, Matthew J; Rome, Jonathan J; Glatz, Andrew C

2015-01-01

400

Long-term exposure to microwave radiation provokes cancer growth: evidences from radars and mobile communication systems.  

PubMed

In this review we discuss alarming epidemiological and experimental data on possible carcinogenic effects of long term exposure to low intensity microwave (MW) radiation. Recently, a number of reports revealed that under certain conditions the irradiation by low intensity MW can substantially induce cancer progression in humans and in animal models. The carcinogenic effect of MW irradiation is typically manifested after long term (up to 10 years and more) exposure. Nevertheless, even a year of operation of a powerful base transmitting station for mobile communication reportedly resulted in a dramatic increase of cancer incidence among population living nearby. In addition, model studies in rodents unveiled a significant increase in carcinogenesis after 17-24 months of MW exposure both in tumor-prone and intact animals. To that, such metabolic changes, as overproduction of reactive oxygen species, 8-hydroxi-2-deoxyguanosine formation, or ornithine decarboxylase activation under exposure to low intensity MW confirm a stress impact of this factor on living cells. We also address the issue of standards for assessment of biological effects of irradiation. It is now becoming increasingly evident that assessment of biological effects of non-ionizing radiation based on physical (thermal) approach used in recommendations of current regulatory bodies, including the International Commission on Non-Ionizing Radiation Protection (ICNIRP) Guidelines, requires urgent reevaluation. We conclude that recent data strongly point to the need for re-elaboration of the current safety limits for non-ionizing radiation using recently obtained knowledge. We also emphasize that the everyday exposure of both occupational and general public to MW radiation should be regulated based on a precautionary principles which imply maximum restriction of excessive exposure. PMID:21716201

Yakymenko, I; Sidorik, E; Kyrylenko, S; Chekhun, V

2011-06-01

401

Spectral Analyses and Radiation Exposures from Several Ground-Level Enhancement (GLE) Solar Proton Events: A Comparison of Methodologies  

NASA Technical Reports Server (NTRS)

Several methods for analyzing the particle spectra from extremely large solar proton events, called Ground-Level Enhancements (GLEs), have been developed and utilized by the scientific community to describe the solar proton energy spectra and have been further applied to ascertain the radiation exposures to humans and radio-sensitive systems, namely electronics. In this paper 12 GLEs dating back to 1956 are discussed, and the three methods for describing the solar proton energy spectra are reviewed. The three spectral fitting methodologies are EXP [an exponential in proton rigidity (R)], WEIB [Weibull fit: an exponential in proton energy], and the Band function (BAND) [a double power law in proton rigidity]. The EXP and WEIB methods use low energy (MeV) GLE solar proton data and make extrapolations out to approx.1 GeV. On the other hand, the BAND method utilizes low- and medium-energy satellite solar proton data combined with high-energy solar proton data deduced from high-latitude neutron monitoring stations. Thus, the BAND method completely describes the entire proton energy spectrum based on actual solar proton observations out to 10 GeV. Using the differential spectra produced from each of the 12 selected GLEs for each of the three methods, radiation exposures are presented and discussed in detail. These radiation exposures are then compared with the current 30-day and annual crew exposure limits and the radiation effects to electronics.

Atwell, William; Tylka, Allan; Dietrich, William; Badavi, Francis; Rojdev, Kristina

2011-01-01

402

Space radiation protection: Human support thrust exploration technology program  

NASA Technical Reports Server (NTRS)

Viewgraphs on space radiation protection are presented. For crew and practical missions, exploration requires effective, low-mass shielding and accurate estimates of space radiation exposure for lunar and Mars habitat shielding, manned space transfer vehicle, and strategies for minimizing exposure during extravehicular activity (EVA) and rover operations.

Conway, Edmund J.

1991-01-01

403

Ionizing Radiation and Humans â The Basics  

NSDL National Science Digital Library

This Physics Central webpage contains an article that provides basic information on ionizing radiation and its effects on human beings. The website uses simple terminologies, symbols and diagrams to display the information. The information contained in the website also aims at dispelling popular misconceptions among the public. Also, natural sources of radiation and their amounts are discussed. Key terminologies and related subjects contain links to external websites that have more information on them. The web article also has a list of references for the user to gain further information this subject.

2012-06-26

404

Proposed alternatives for a DOE-wide occupational radiation exposure information system  

SciTech Connect

The Radiation Exposure Information Reporting System (REIRS) was initiated by the Atomic Energy Commission (AEC) in 1968. While the system has provided a general overview of radiation exposures associated with AEC/ERDA/DOE operations and has satisfied the original intent for a central information system, the need for more detailed information has become evident. The alternatives addressed for a radiation exposure information system were no change in current system, clarification of DOE Order for current system, increased summary information from sites, centralized annual individual dose (exposure) system, and annual dose summary and locator files. A majority of the DOE Ad Hoc Committee has concurred to recommend the annual dose summary and locator files (ADSLF). The acceptance of the ADSLF alternative as the DOE-wide radiation exposure system would give DOE added capability and flexibility in responding to requests for information and would reduce the impact on the sites of special survey requests.

Murphy, B.L.; Murphy, D.W.; Fix, J.J.; Selby, J.M.; Vallario, E.J.

1984-02-01

405

Short-duration exposure to radiofrequency electromagnetic radiation alters the chlorophyll fluorescence of duckweeds (Lemna minor).  

PubMed

Plants growing in natural environments are exposed to radiofrequency electromagnetic radiation (EMR) emitted by various communication network base stations. The environmental concentration of this radiation is increasing rapidly with the congested deployment of base stations. Although numerous scientific studies have been conducted to investigate the effects of EMR on the physiology of humans and animals, there have been few attempts to investigate the effects of EMR on plants. In this study, we attempted to evaluate the effects of EMR on photosynthesis by investigating the chlorophyll fluorescence (ChF) parameters of duckweed fronds. During the experiment, the fronds were tested with 2, 2.5, 3.5, 5.5 and 8?GHz EMR frequencies, which are not widely studied even though there is a potentially large concentration of these frequencies in the environment. The duckweed fronds were exposed to EMR for 30?min, 1?h and 24?h durations with electric field strength of 45-50?V/m for each frequency. The results indicated that exposure to EMR causes a change in the non-photochemical quenching of the duckweeds. The changes varied with the frequency of the EMR and were time-varying within a particular frequency. The temperature remained unchanged in the duckweed fronds upon exposure to EMR, which confirms that the effect is non-thermal. PMID:24131393

Senavirathna, Mudalige Don Hiranya Jayasanka; Takashi, Asaeda; Kimura, Yuichi

2014-12-01

406

Conceptual basis for evaluating risk from low-level radiation exposure  

SciTech Connect

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

Bond, V.P.

1981-01-01

407

ANALYSIS OF HUMAN ACTIVITY DATA FOR USE IN MODELING ENVIRONMENTAL EXPOSURES  

EPA Science Inventory

Human activity data are a critical part of exposure models being developed by the US EPA's National Exposure Research Laboratory (NERL). An analysis of human activity data within NERL's Consolidated Human Activity Database (CHAD) was performed in two areas relevant to exposure ...

408

Modelling the effects of ionizing radiation on survival of animal population: acute versus chronic exposure.  

PubMed

The objective of the present paper was application of a model, which was originally developed to simulate chronic ionizing radiation effects in a generic isolated population, to the case of acute exposure, and comparison of the dynamic features of radiation effects on the population survival in cases of acute and chronic exposure. Two modes of exposure were considered: acute exposure (2-35 Gy) and chronic lifetime exposure with the same integrated dose. Calculations were made for a generic mice population; however, the model can be applied for other animals with proper selection of parameter values. In case of acute exposure, in the range 2-11 Gy, the population response was in two phases. During a first phase, there was a depletion in population survival; the second phase was a recovery period due to reparation of damage and biosynthesis of new biomass. Model predictions indicate that a generic mice population, living in ideal conditions, has the potential for recovery (within a mouse lifetime period) from acute exposure with dose up to 10-11 Gy, i.e., the population may recover from doses above an LD50 (6.2 Gy). Following acute doses above 14 Gy, however, the mice population went to extinction without recovery. In contrast, under chronic lifetime exposures (500 days), radiation had little effect on population survival up to integrated doses of 14-15 Gy, so the survival of a population subjected to chronic exposure was much better compared with that after an acute exposure with the same dose. Due to the effect of "wasted radiation", the integrated dose of chronic exposure could be about two times higher than acute dose, producing the same effect on survival. It is concluded that the developed generic population model including the repair of radiation damage can be applied both to acute and chronic modes of exposure; results of calculations for generic mice population are in qualitative agreement with published data on radiation effects in mice. PMID:25481246

Kryshev, A I; Sazykina, T G

2014-12-01

409

Human exposure, biomarkers, and fate of organotins in the environment.  

PubMed

Organotin compounds result from the addition of organic moieties to inorganic tin.Thus, one or more tin-carbon bonds exist in each organotin molecule. The organo-tin compounds are ubiquitous in the environment. Organotin compounds have many uses, including those as fungicides and stabilizers in plastics, among others in industry. The widespread use of organotins as antifouling agents in boat paints has resulted in pollution of freshwater and marine ecosystems. The presence of organotin compounds in freshwater and marine ecosystems is now understood to be a threat, because of the amounts found in water and the toxicity of some organotin compounds to aquatic organisms, and perhaps to humans as well. Organotin com-pounds are regarded by many to be global pollutants of a stature similar to biphenyl,mercury, and the polychlorinated dibenzodioxins. This stature results from the high toxicity, persistence, bioaccumulation, and endocrine disruptive features of even very low levels of selected organotin compounds.Efforts by selected governmental agencies and others have been undertaken to find a global solution to organotin pollution. France was the first country to ban the use of the organotins in 1980. This occurred before the international maritime organization (IMO) called for a global treaty to ban the application of tributyltin (TBT)-based paints. In this chapter, we review the organotin compounds with emphasis on the human exposure, fate, and distribution of them in the environment. The widespread use of the organotins and their high stability have led to contamination of some aquatic ecosystems. As a result, residues of the organotins may reach humans via food consumption. Notwithstanding the risk of human exposure, only limited data are available on the levels at which the organotins exist in foodstuffs consumed by humans. Moreover, the response of marine species to the organotins, such as TBT, has not been thoroughly investigated. Therefore, more data on the organotins and the consequences of exposure to them are needed. In particular, we believe the following areas need attention: expanded toxicity testing in aquatic species, human exposure, human body burdens, and the research to identify biomarkers for testing the toxicity of the organotins to marine invertebrates. PMID:21541847

Okoro, Hussein K; Fatoki, Olalekan S; Adekola, Folahan A; Ximba, Bhekumusa J; Snyman, Reinette G; Opeolu, Beatrice

2011-01-01

410

Assessment of human exposure to chemicals from Superfund sites.  

PubMed Central

Assessing human exposure to chemicals from Superfund sites requires knowledge of basic physical, chemical, and biological processes occurring in the environment and specific information about the local environment and population in the vicinity of sites of interest. Although progress is being made in both areas, there is still a tremendous amount to be done. Participants at this meeting have identified several of the areas in need of greater understanding, and they are listed below. Movement of dissolved and volatile organics, especially NAPLs, in the subsurface environment. This includes study of the partitioning of compounds between NAPLs, air, water, and soil. Partitioning of volatilized chemicals between gaseous and aerosol components of the atmosphere. This includes understanding how these components influence both wet and dry deposition. Long-term movement from sediments into biota and how these affect chronic toxicity to sediment biota. Broad validation of PBPK models describing partitioning of compounds from sediment and water into fish. Reactions of chemicals sorbed to atmospheric particles. This includes application of laboratory models to real and varied atmospheric conditions. Interactions between biotic and abiotic transformations in soil and sediment. Applicability of physiological pharmacokinetic models developed in laboratory studies of experimental animals and clinical investigations of humans to environmental chemicals, concentrations, and routes of exposure in humans. Use of human and wildlife behavioral and biomonitoring information to estimate exposure. This includes better understanding of human variability and the applicability of information gathered from particular wildlife species. To successfully address these gaps in our knowledge, much more analytical data must be collected.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8187712

Kamrin, M A; Fischer, L J; Suk, W A; Fouts, J R; Pellizzari, E; Thornton, K

1994-01-01

411

Exposure to electromagnetic fields (non-ionizing radiation) and its relationship with childhood leukemia: A systematic review  

Microsoft Academic Search

Childhood exposure to physical contamination, including non-ionizing radiation, has been implicated in numerous diseases, raising concerns about the widespread and increasing sources of exposure to this type of radiation. The primary objective of this review was to analyze the current state of knowledge on the association between environmental exposure to non-ionizing radiation and the risk of childhood leukemia. Scientific publications

I. Calvente; M. F. Fernandez; J. Villalba; N. Olea; M. I. Nuñez

2010-01-01

412

Critical windows of exposure for children's health: cancer in human epidemiological studies and neoplasms in experimental animal models.  

PubMed Central

In humans, cancer may be caused by genetics and environmental exposures; however, in the majority of instances the identification of the critical time window of exposure is problematic. The evidence for exposures occurring during the preconceptional period that have an association with childhood or adulthood cancers is equivocal. Agents definitely related to cancer in children, and adulthood if exposure occurs in utero, include: maternal exposure to ionizing radiation during pregnancy and childhood leukemia and certain other cancers, and maternal use of diethylstilbestrol during pregnancy and clear-cell adenocarcinoma of the vagina of their daughters. The list of environmental exposures that occur during the perinatal/postnatal period with potential to increase the risk of cancer is lengthening, but evidence available to date is inconsistent and inconclusive. In animal models, preconceptional carcinogenesis has been demonstrated for a variety of types of radiation and chemicals, with demonstrated sensitivity for all stages from fetal gonocytes to postmeiotic germ cells. Transplacental and neonatal carcinogenesis show marked ontogenetic stage specificity in some cases. Mechanistic factors include the number of cells at risk, the rate of cell division, the development of differentiated characteristics including the ability to activate and detoxify carcinogens, the presence of stem cells, and possibly others. Usefulness for human risk estimation would be strengthened by the study of these factors in more than one species, and by a focus on specific human risk issues. Images Figure 1 PMID:10852857

Anderson, L M; Diwan, B A; Fear, N T; Roman, E

2000-01-01

413

Minimizing occupational and patient radiation exposure using an optimized injection technique  

SciTech Connect

In an attempt to lower whole-body and hand radiation exposure to the technologist and decrease the number of infiltrated doses, this laboratory instituted a cold start method for radionuclide injection. The authors then compared the radiation dosimetry readings for a period before and after instituting the method. The finger ring exposures and whole-body exposures were compared. The exposure to the technologist's hands was reduced by 56% and to the technologist's body by 28%. Detectable extravasation of the dose was reduced from 64% to 9%. The recommend the use of this technique for all nuclear medicine departments.

Holly, A.S.; Stumpf, K.D.; Ortendahl, D.A.; Hattner, R.S.

1987-12-01

414

Heavy Ion Radiation Exposure Triggered Higher Intestinal Tumor Frequency and Greater ?-Catenin Activation than ? Radiation in APCMin/+ Mice  

PubMed Central

Risk of colorectal cancer (CRC) after exposure to low linear energy transfer (low-LET) radiation such as ?-ray is highlighted by the studies in a