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1

Biomarkers for human radiation exposure.  

PubMed

There is a concern over the potential use of radioactive isotopes as a weapon of terror. The detonation of a radiation dispersal device, the so-called "dirty bomb" can lead to public panic. In order to estimate risks associated with radiation exposure, it is important to understand the biological effects of radiation exposure. Based on this knowledge, biomarkers to monitor potentially exposed populations after a radiological accident can be developed and would be extremely valuable for emergency response. While the traditional radiation exposure biomarkers based on cytogenetic assays serve as standard, the development of rapid and noninvasive tests for radiation exposure is needed. The genomics based knowledge is providing new avenues for investigation. The examination of gene expression after ionizing radiation exposure could serve as a potential molecular marker for biodosimetry. Microarray based studies are identifying new radiation responsive genes that could potentially be used as biomarkers of human exposure to radiation after an accident. PMID:18454354

Chaudhry, M Ahmad

2008-09-01

2

Biomarkers for human radiation exposure  

Microsoft Academic Search

There is a concern over the potential use of radioactive isotopes as a weapon of terror. The detonation of a radiation dispersal\\u000a device, the so-called “dirty bomb” can lead to public panic. In order to estimate risks associated with radiation exposure,\\u000a it is important to understand the biological effects of radiation exposure. Based on this knowledge, biomarkers to monitor\\u000a potentially

M. Ahmad Chaudhry

2008-01-01

3

Ultraviolet Radiation: Human Exposure and Health Risks.  

ERIC Educational Resources Information Center

Provides an overview of human exposure to ultraviolet radiation and associated health effects as well as risk estimates for acute and chronic conditions resulting from such exposure. Demonstrates substantial reductions in health risk that can be achieved through preventive actions. Also includes a risk assessment model for skin cancer. Contains 36…

Tenkate, Thomas D.

1998-01-01

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

Exposure to UV radiation and human health  

NASA Astrophysics Data System (ADS)

This paper will overview the significant issues facing researchers in relating the impact of exposure to sunlight and human health. Exposure to solar ultraviolet radiation is the major causative factor in most sun-related skin and eye disorders, however, very little is known quantitatively about human UV exposures. Interestingly, human exposure to sunlight also has a nutritional impact, namely the development of pre-Vitamin D, which is an important nutrient in bone health. New research suggest that low vitamin D status may be a causative factor in the development of selective types of cancer and autoimminue diseases, as well as a contributing factor in bone health. The 'health duality' aspect of sunlight exposure is an interesting and controversial topic that is a research focus of Kimlin's research group.

Kimlin, Michael G.

2005-08-01

7

Radiation exposure for human Mars exploration.  

PubMed

One major obstacle to human space exploration is the possible limitations imposed by the adverse effects of long-term exposure to the space environment. Even before human space flight began, the potentially brief exposure of astronauts to the very intense random solar energetic particle events was of great concern. A new challenge appears in deep-space exploration from exposure to the low-intensity heavy-ion flux of the galactic cosmic rays since the missions are of long duration, and accumulated exposures can be high. Because cancer induction rates increase behind low to moderate thicknesses of aluminum shielding, according to available biological data on mammalian exposures to galactic cosmic ray-like ions, aluminum shield requirements for a Mars mission may be prohibitively expensive in terms of mission launch costs. Alternative materials for vehicle construction are under investigation to provide lightweight habitat structures with enhanced shielding properties. In the present paper, updated estimates for astronaut exposures on a Mars mission are presented and shielding properties of alternative materials are compared with aluminum. PMID:11045525

Simonsen, L C; Wilson, J W; Kim, M H; Cucinotta, F A

2000-11-01

8

Gene expression as a biomarker for human radiation exposure.  

PubMed

Accidental exposure to ionizing radiation can be unforeseen, rapid, and devastating. The detonation of a radiological device leading to such an exposure can be detrimental to the exposed population. The radiation-induced damage may manifest as acute effects that can be detected clinically or may be more subtle effects that can lead to long-term radiation-induced abnormalities. Accurate identification of the individuals exposed to radiation is challenging. The availability of a rapid and effective screening test that could be used as a biomarker of radiation exposure detection is mandatory. We tested the suitability of alterations in gene expression to serve as a biomarker of human radiation exposure. To develop a useful gene expression biomonitor, however, gene expression changes occurring in response to irradiation in vivo must be measured directly. Patients undergoing radiation therapy provide a suitable test population for this purpose. We examined the expression of CC3, MADH7, and SEC PRO in blood samples of these patients before and after radiotherapy to measure the in vivo response. The gene expression after ionizing radiation treatment varied among different patients, suggesting the complexity of the response. The expression of the SEC PRO gene was repressed in most of the patients. The MADH7 gene was found to be upregulated in most of the subjects and could serve as a molecular marker of radiation exposure. PMID:23446844

Omaruddin, Romaica A; Roland, Thomas A; Wallace, H James; Chaudhry, M Ahmad

2013-03-01

9

Human Health and Exposure to Electromagnetic Radiation.  

National Technical Information Service (NTIS)

This review consists of three main parts. In the first the general features of electromagnetic fields and their interactions with the human body are described. It is pointed out that some evidence from biological experiments means that it is not a priori ...

J. A. Dennis C. R. Muirhead J. R. Ennis

1992-01-01

10

Human Exposure to Radiofrequency Radiation. A Review Pertinent to Air Force Operations.  

National Technical Information Service (NTIS)

This report presents analyses studies, research results, and other pertinent information related to investigations of human exposure to radiofrequency radiation (RFR). The topics discussed are the ANSI/IEEE RFR-exposure guidelines; environmental levels in...

L. N. Heynick P. Polson

1996-01-01

11

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

12

UV Straling: Blootstelling van de Mens aan Ultraviolette Straling (UV Radiation: Human Exposure to Ultraviolet Radiation).  

National Technical Information Service (NTIS)

The report presents recommendations for the safe use of artificially generated ultraviolet (UV) radiation. Exposure to radiation from UV-lasers is not considered here, although some of the recommendations are also valid for radiation from this type of equ...

1986-01-01

13

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.

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

2014-01-01

14

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

15

Gene Expression Signatures That Predict Radiation Exposure in Mice and Humans  

PubMed Central

Background The capacity to assess environmental inputs to biological phenotypes is limited by methods that can accurately and quantitatively measure these contributions. One such example can be seen in the context of exposure to ionizing radiation. Methods and Findings We have made use of gene expression analysis of peripheral blood (PB) mononuclear cells to develop expression profiles that accurately reflect prior radiation exposure. We demonstrate that expression profiles can be developed that not only predict radiation exposure in mice but also distinguish the level of radiation exposure, ranging from 50 cGy to 1,000 cGy. Likewise, a molecular signature of radiation response developed solely from irradiated human patient samples can predict and distinguish irradiated human PB samples from nonirradiated samples with an accuracy of 90%, sensitivity of 85%, and specificity of 94%. We further demonstrate that a radiation profile developed in the mouse can correctly distinguish PB samples from irradiated and nonirradiated human patients with an accuracy of 77%, sensitivity of 82%, and specificity of 75%. Taken together, these data demonstrate that molecular profiles can be generated that are highly predictive of different levels of radiation exposure in mice and humans. Conclusions We suggest that this approach, with additional refinement, could provide a method to assess the effects of various environmental inputs into biological phenotypes as well as providing a more practical application of a rapid molecular screening test for the diagnosis of radiation exposure.

Dressman, Holly K; Muramoto, Garrett G; Chao, Nelson J; Meadows, Sarah; Marshall, Dawn; Ginsburg, Geoffrey S; Nevins, Joseph R; Chute, John P

2007-01-01

16

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

17

Non-ionising radiation human exposure assessment near telecommunication devices in Croatia.  

PubMed

This paper gives an overview of the regulatory acts in non-ionising radiation in the world, with a special emphasis on basic guidelines issued by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). ICNIRP Guidelines are implemented in many countries worldwide. Croatia has also implemented them indirectly through the European Recommendation 1999/519/EC. The Croatian regulatory acts include the Non-lonising Radiation Protection Act, Ordinance on Electromagnetic Fields (EMF) Protection, and the Ordinance on Basic Requirements for Devices which produce Optical Radiation and Measures for Optical Radiation Protection. Dosimetry and densitometry are compliant with relevant international and European standards. The paper presents an example of densitometric human exposure assessment in complex indoor exposure conditions. In spite of a high number of indoor and outdoor sources and the "worst-case exposure assessment", the results are within the limits defined by the Croatian EMF Ordinance. PMID:16605167

Simuni?, Dina

2006-03-01

18

DNA Repair and Cell Cycle Biomarkers of Radiation Exposure and Inflammation Stress in Human Blood  

PubMed Central

DNA damage and repair are hallmarks of cellular responses to ionizing radiation. We hypothesized that monitoring the expression of DNA repair-associated genes would enhance the detection of individuals exposed to radiation versus other forms of physiological stress. We employed the human blood ex vivo radiation model to investigate the expression responses of DNA repair genes in repeated blood samples from healthy, non-smoking men and women exposed to 2 Gy of X-rays in the context of inflammation stress mimicked by the bacterial endotoxin lipopolysaccharide (LPS). Radiation exposure significantly modulated the transcript expression of 12 genes of 40 tested (2.2E-06human blood ex vivo dataset, and 100% accuracy for discriminating patients who received total body radiation. Three genes of this panel (CDKN1A, FDXR and BBC3) were also highly sensitive to LPS treatment in the absence of radiation exposure, and LPS co-treatment significantly affected their radiation responses. At the protein level, BAX and pCHK2-thr68 were elevated after radiation exposure, but the pCHK2-thr68 response was significantly decreased in the presence of LPS. Our combined panel yields an estimated 4-group accuracy of ?90% to discriminate between radiation alone, inflammation alone, or combined exposures. Our findings suggest that DNA repair gene expression may be helpful to identify biodosimeters of exposure to radiation, especially within high-complexity exposure scenarios.

Marchetti, Francesco; Mannion, Brandon; Bhatnagar, Sandhya; Kwoh, Ely; Tan, Yuande; Wang, Shan X.; Blakely, William F.; Coleman, Matthew; Peterson, Leif; Wyrobek, Andrew J.

2012-01-01

19

[Human behavior in the solar radiation field with reference to ultraviolet exposure].  

PubMed

There is a causal relation between solar ultraviolet radiation and skin cancer. For epidemiological investigations, quantification of the UV exposure is essential. To set up a risk assessment for the whole population, a representative survey was performed in Austria. The questionnaire refers to three sectors of everyday life: work, recreation and holidays; in addition the use of solaria is asked about for a further investigation. The UV exposure caused by humans' behaviour in the field of solar radiation was analysed from various demographic aspects. For some subpopulations the UV exposure sustained during work, recreation and holidays was compared. Groups with high occupational UV exposure show a weaker tendency to stay outdoors during leisure time and holidays than groups characterized by high UV exposure in their leisure time, who also prefer sun-intensive activities during holidays. PMID:1399598

Schauberger, G; Keck, G; Cabaj, A

1992-09-01

20

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

21

Exposure to extremely-low-frequency electromagnetic fields and radiofrequency radiation: cardiovascular effects in humans  

Microsoft Academic Search

Cardiovascular changes in humans exposed to nonionizing radiation [including extremely-low-frequency electromagnetic fields\\u000a (ELF EMFs) and radiofrequency radiation (RFR)] are reviewed. Both acute and long-term effects have been investigated. In general,\\u000a if heating does not occur during exposure, current flow appears to be necessary for major cardiovascular effects to ensue,\\u000a such as those due to electric shock. Whereas most studies have

James R. Jauchem

1997-01-01

22

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

SciTech Connect

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.

Fabrikant, J.I.

1982-08-01

23

Clinical distinctions of radiation sickness with exposure of different parts of the human body to radiation  

SciTech Connect

The clinical picture of radiation sickness of 139 radiological patients exposed to local irradition of the head, chest, and stomach with efficient doses of 210 rad was examined. It was found that at fractionated local irraditions the clinical symptom-complex of radiation sickness was identifical to that seen as a result of total-body irradiation. During head irradiation the major symptom was headache and during stomach irradiation nausea. The severity level of radiation damage measured with respect to the clinical symptom-complex as a whole with the aid of the bioinformation model was similar during irradiations of the head and stomach, much higher during irradiation of the chest. During head and stomach irradiations the severity level of radiation damage was proportional to the efficient dose. During chest irradiation there was no correlation between the severity level and the exposure to doses of 210 rad.

Nevskaya, G.F.; Abramova, G.M.; Volkova, M.A.; Kavlycheva, Y.V.; Skorik, A.S.; Yurogov, V.V.

1982-01-12

24

Dynamics of the transcriptome response of cultured human embryonic stem cells to ionizing radiation exposure.  

PubMed

One of the key consequences of exposure of human cells to genotoxic agents is the activation of DNA damage responses (DDR). While the mechanisms underpinning DDR in fully differentiated somatic human cells have been studied extensively, molecular signaling events and pathways involved in DDR in pluripotent human embryonic stem cells (hESC) remain largely unexplored. We studied changes in the human genome-wide transcriptome of H9 hESC line following exposures to 1Gy of gamma-radiation at 2h and 16h post-irradiation. Quantitative real-time PCR was performed to verify the expression data for a subset of genes. In parallel, the cell growth, DDR kinetics, and expression of pluripotency markers in irradiated hESC were monitored. The changes in gene expression in hESC after exposure to ionizing radiation (IR) are substantially different from those observed in somatic human cell lines. Gene expression patterns at 2h post-IR showed almost an exclusively p53-dependent, predominantly pro-apoptotic, signature with a total of only 30 up-regulated genes. In contrast, the gene expression patterns at 16h post-IR showed 354 differentially expressed genes, mostly involved in pro-survival pathways, such as increased expression of metallothioneins, ubiquitin cycle, and general metabolism signaling. Cell growth data paralleled trends in gene expression changes. DDR in hESC followed the kinetics reported for human somatic differentiated cells. The expression of pluripotency markers characteristic of undifferentiated hESC was not affected by exposure to IR during the time course of our analysis. Our data on dynamics of transcriptome response of irradiated hESCs may provide a valuable tool to screen for markers of IR exposure of human cells in their most naive state; thus unmasking the key elements of DDR; at the same time, avoiding the complexity of interpreting distinct cell type-dependent genotoxic stress responses of terminally differentiated cells. PMID:21376742

Sokolov, Mykyta V; Panyutin, Irina V; Panyutin, Igor G; Neumann, Ronald D

2011-05-10

25

A Cell Kinetic Model of Granulocytopoiesis Under Radiation Exposure: Extension from Murines to Canines and Humans  

NASA Technical Reports Server (NTRS)

Space radiation poses significant challenges to space travel, and it is essential to understand the possible adverse effects from space radiation exposure to the radiosensitive organ systems that are important for immediate survival of human, e.g., the hematopoietic system. In this presentation a biomathematical model of granulocytopoiesis is described and used to analyze the blood granulocyte changes seen in the blood of mammalians under continuous and acute radiation exposure. This is one of a set of hematopoietic models that have been successfully utilized to simulate and interpret the experimental data of acute and chronic radiation on rodents. We discuss the underlying implicit regulation mechanism and the biological relevance of the kinetic parameters estimation method. Extension of the model to predictions in dogs and humans systems indicates that the modeling results are consistent with the cumulative experimental and empirical data from various sources. This implies the potential to integrate the models into one united system for monitoring the hematopoietic response of various species under irradiation. Based on the evidence of threshold responses of dogs to extended periods of low daily dose exposures, we discuss the potential health risks of the space traveler under chronic stress of low-dose irradiation and the possibly encountered Solar Particle Events.

Hu, Shaowen; Cucinotta, Francis A.

2009-01-01

26

Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation  

SciTech Connect

This project seeks to defining the chromosome segments associated with radiation induced leukemogenesis (treatment-related acute myeloid leukemia, or t-AML). Towards these goals genetic analysis of human chromosomes 5 and 7 continues to investigate correlation of treatment with balanced and unbalanced chromosomal translocations. Progress is being made in cloning the breakpoints in balanced translocations in t-AML, that is to clone the t(9;11) and t(11;19) breakpoints, to clone the t(3;21)(q26;q22) breakpoints and to determine the relationship of these translocations to prior exposure to topoisomerase II inhibitors. 11 figs. 3 figs.

Rowley, J.D.

1992-06-01

27

Human exposure to space radiation: role of primary and secondary particles.  

PubMed

Human exposure to space radiation implies two kinds of risk, both stochastic and deterministic. Shielding optimisation therefore represents a crucial goal for long-term missions, especially in deep space. In this context, the use of radiation transport codes coupled with anthropomorphic phantoms allows to simulate typical radiation exposures for astronauts behind different shielding, and to calculate doses to different organs. In this work, the FLUKA Monte Carlo code and two phantoms, a mathematical model and a voxel model, were used, taking the Galactic Cosmic Rays (GCR) spectra from the model of Badhwar and O'Neill. The time integral spectral proton fluence of the August 1972 Solar Particle Event (SPE) was represented by an exponential function. For each aluminium shield thickness, besides total doses the contributions from primary and secondary particles for different organs and tissues were calculated separately. More specifically, organ-averaged absorbed doses, dose equivalents and a form of 'biological dose', defined on the basis of initial (clustered) DNA damage, were calculated. As expected, the SPE doses dramatically decreased with increasing shielding, and doses in internal organs were lower than in skin. The contribution of secondary particles to SPE doses was almost negligible; however it is of note that, at high shielding (10 g cm(-2)), most of the secondaries are neutrons. GCR organ doses remained roughly constant with increasing Al shielding. In contrast to SPE results, for the case of cosmic rays, secondary particles accounted for a significant fraction of the total dose. PMID:17151013

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

2006-01-01

28

Protein expression in human lymphocytes and fibroblasts after in vitro radiation exposure  

NASA Astrophysics Data System (ADS)

Radiation exposure of cells can induce molecular changes that modulate the metabolic activity of many proteins, which is ultimately responsible for the final outcomes of radiation insults. Simultaneous measurements of multiple proteins were performed on human lymphocyte and fibroblast cells before and after irradiation using two new technologies - the SELDI ProteinChip Sy stem and the Luminex 100 System. The surface-enhanced laser desorption/ionization (SELDI) system is a protein time-of-flight mass spectrometer and the technology offers the advantages of speed, simplicity, sensitivity and accuracy. The Luminex technology, on the other hand, is a new generation of fluorescent microsphere-based flow cytometry that enables simultaneous assay of up to 100 proteins in a single well or tube. These advanced systems offer the sensitivity and resolution required to perform the qualitative and quantitative assessment of the protein expression spectrum. In the study, the two types of human cells were exposed in vitro to both low and high doses of gamma rays and proteins were collected at various times after exposure. Defined media and spin columns were used to eliminate highly abundant proteins. Preliminary results of the study will be presented.

Wu, H.; Desai, N.; George, K.; Gonda, S.; Cucinotta, F.

29

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.

Program, U. S.

30

Impact of the Near-Earth Space Environment on Human Radiation Exposure at Commercial Airline Altitudes  

NASA Astrophysics Data System (ADS)

There is a growing concern for the health and safety of commercial aircrew and passengers due to their exposure to ionizing radiation with high linear energy transfer (LET), particularly at high latitudes. The International Commission of Radiobiological Protection (ICRP), the EPA, and the FAA consider the crews of commercial aircraft as radiation workers. The FAA reports that pregnant crew members may run a risk as high as 1.3 per thousand births of severe illness to their children as a result of background radiation exposure. During solar energetic particle (SEP) events, radiation exposure can exceed annual limits, and the number of serious health effects is expected to be quite high if precautions are not taken. Health concerns for frequent-flyer passengers are similar to the health concerns of the crew. There is a need for a capability to monitor background radiations levels at commercial airline altitudes and to provide analytical input for airline operations decisions for altering flight paths and altitudes for the mitigation and reduction of radiation exposure levels during a SEP event. Efforts are currently underway to develop a global, nowcast (real-time) capability for calculating ionizing radiation exposure at commercial airline altitudes. The state-of-the-art in physics-based transport of high energy galactic cosmic ray and solar cosmic ray particles will be presented. Paramount to reliable real-time transport calculations is an accurate and timely specification of the boundary conditions, such as the incident differential energy flux and geomagnetic cutoff rigidity, using a combination of satellite observations and empirical space radiation environment models. However, empirical models of the near-Earth radiation environment can only advance with continued observations and development of physics-based models of the heliosphere and the coupled magnetosphere-ionosphere-thermosphere system. In this paper we also discuss the state-of-the-art in space radiation environment modeling, in relation to atmospheric radiation exposure, and discuss the future needs in modeling and observations.

Mertens, C. J.; Blattnig, S. R.; Solomon, S. C.; Wiltberger, M. J.; Kunches, J.; Kress, B. T.; Murray, J. J.; Wilson, J. W.

2005-12-01

31

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.

32

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

33

Pregnancy and Radiation Exposure  

MedlinePLUS

... Study Released . PDS on Radiation Instruments . Update of Nuclear Power Environmental Standards Upcoming Events . NRC Meeting Webcasts - ... Exposure to the Embryo or Fetus from Diagnostic Nuclear Medicine Pregnant women may be administered radioactive materials ...

34

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

Microsoft Academic Search

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

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

2008-01-01

35

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

36

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

37

Mental process in humans and exposure to cell-phone radiation  

Microsoft Academic Search

This paper reports on human exposure to cell-phone microwave fields may affect such mental processes (or cognitive functions) as attentional function, short-term memory tasks, information manipulation, or response-reaction times.

James C. Lin

2004-01-01

38

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

39

[The relative biological effectiveness of alpha-radiation during human lung exposure to irradiation].  

PubMed

The assessment of the relative biological effectiveness (RBE) for alpha-radiation was held in the cases of inhalation of radon progeny and incorporation of plutonium in lungs. It is based on simulation of lung cancer radiation risk for different types of radiation. Specific radiation risk models developed according to the results of direct epidemiological studies are used for the simulation. These include two published risk models for uranium miners and nuclear workers of the Mayak facilities in the former Soviet Union. Additionally two lung cancer risk models are developed and described for the following cases: population indoor radon exposure and low-linear-energy-transfer reference radiation exposure. By the results of lifetime lung cancer risk simulation the RBE values range from 11 to 12 and from 1.7 to 4.9 for the cases of plutonium incorporation and of radon progeny exposure accordingly. The significant uncertainty of radiation risk models results in significant variation of RBE assessments. Rough estimations of RBE values 90% confidence interval are from unit fraction to 25 and from 2 to 50 for the cases of radon progeny exposure and plutonium incorporation accordingly. PMID:16209188

Iarmoshenko, I V; Kirdin, I A; Zhukovski?, M V

2005-01-01

40

Radiation exposure and chromosome abnormalities. Human cytogenetic studies at the National Institute of Radiological Sciences, Japan, 1963-1988.  

PubMed

The results of human cytogenetic studies performed at the National Institute of Radiological Sciences (NIRS), Chiba, Japan for about 25 years are described. The studies were pursued primarily under two major projects: one involving people exposed to radiation under various conditions and the other involving patients with malignant diseases, especially leukemias. Whereas chromosome abnormalities in radiation-exposed people are excellent indicators of radiation exposure, their behavior in bone marrow provide useful information for a better understanding of chromosome abnormalities in leukemias and related disorders. The role of chromosome abnormalities in the genesis and development of leukemia and related disorders is considered, suggesting a view for future studies in this field. PMID:2302680

Ishihara, T; Kohno, S; Minamihisamatsu, M

1990-03-01

41

Radiation exposure and chromosome abnormalities. Human cytogenetic studies at the National Institute of Radiological Sciences, Japan, 1963-1988  

SciTech Connect

The results of human cytogenetic studies performed at the National Institute of Radiological Sciences (NIRS), Chiba, Japan for about 25 years are described. The studies were pursued primarily under two major projects: one involving people exposed to radiation under various conditions and the other involving patients with malignant diseases, especially leukemias. Whereas chromosome abnormalities in radiation-exposed people are excellent indicators of radiation exposure, their behavior in bone marrow provide useful information for a better understanding of chromosome abnormalities in leukemias and related disorders. The role of chromosome abnormalities in the genesis and development of leukemia and related disorders is considered, suggesting a view for future studies in this field.

Ishihara, T.; Kohno, S.; Minamihisamatsu, M. (National Institute of Radiological Sciences, Chiba (Japan))

1990-03-01

42

Effect of cell-phone radiation exposure on cognitive function in humans  

Microsoft Academic Search

Several papers reporting on cognitive function and exposure to cell-phone RF fields have appeared in scientific journals. Human subjects exposed to cell-phone fields showed faster responses in simple reaction time and in choice reaction time. In addition, some investigations have found exposure to cell-phone fields has a facilitating effect on tasks that require attention and manipulation of information in working

James C. Lin

2003-01-01

43

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

44

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

45

Effects of Low Doses of Ionizing Radiation Exposures on Stress-Responsive Gene Expression in Human Embryonic Stem Cells  

PubMed Central

There is a great deal of uncertainty on how low (?0.1 Gy) doses of ionizing radiation (IR) affect human cells, partly due to a lack of suitable experimental model systems for such studies. The uncertainties arising from low-dose IR human data undermine practical societal needs to predict health risks emerging from diagnostic medical tests’ radiation, natural background radiation, and environmental radiological accidents. To eliminate a variability associated with remarkable differences in radioresponses of hundreds of differentiated cell types, we established a novel, human embryonic stem cell (hESC)-based model to examine the radiobiological effects in human cells. Our aim is to comprehensively elucidate the gene expression changes in a panel of various hESC lines following low IR doses of 0.01; 0.05; 0.1 Gy; and, as a reference, relatively high dose of 1 Gy of IR. Here, we examined the dynamics of transcriptional changes of well-established IR-responsive set of genes, including CDKN1A, GADD45A, etc. at 2 and 16 h post-IR, representing “early” and “late” radioresponses of hESCs. Our findings suggest the temporal- and hESC line-dependence of stress gene radioresponses with no statistically significant evidence for a linear dose-response relationship within the lowest doses of IR exposures.

Sokolov, Mykyta; Neumann, Ronald

2014-01-01

46

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...

47

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.

Cardis, E

1996-01-01

48

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

49

Calculation of the radiation doses occurring in the human body for inadvertent ingestion of soil and other soil exposure pathways  

NASA Astrophysics Data System (ADS)

We estimate the radiation doses in the human body, in the Gudalore region in India, following the inadvertent ingestion of soil and exposure to other soil pathways by measuring Th-232, U-238, and K-40. We estimate the equivalent dose in eleven different organs and the absorbed dose calculations for the whole body. The annual effective doses are calculated, the lowest is in Kariyasolai at 7.8 x 10(-3) mSv whereas the highest is in Ponnur at 8.9 x 10(-2) mSv. In all regions, the lowest equivalent doses through inadvertent soil ingestion are calculated in the kidney and thyroid whereas the highest doses are in the red marrow and on the bone surface.

Oner, F.; Okumuolu, N.

2003-11-01

50

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

51

A comparison of human exposure to natural radiation and DU in parts of the Balkan region  

Microsoft Academic Search

The paper presents the field results from six selected rural communities in the Southeast (Kalna), South (Niska Banja, Gornja Stubla, Borovac) and West (Uzice, Han Pijesak) parts of the Balkan region, where general population exposures to unmodified and technologically enhanced natural radioactive material (TENORM), including ammunition containing depleted uranium (DU) or reprocessed DU as well as indoor high radon, have

Z. S. Zunic; K. Fujimoto; I. V. Yarmoshenko

2005-01-01

52

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...

53

Environmental Radiation Exposures  

Cancer.gov

Atomic Bomb Survivors Semipalatinsk Nuclear Test Site, Kazakhstan Study of Radiation Doses and Cancer Risks Resulting from the 1945 "Trinity" Atomic Weapon Test Thyroid Disease in Young Persons Near Chernobyl Techa River Print This Page Environmental

54

Biological Effects of Low Levels of Radiation Exposure.  

National Technical Information Service (NTIS)

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 ri...

G. W. Casarett

1977-01-01

55

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

56

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

57

[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

58

Dose-Dependent Generation of RET\\/PTC in Human Thyroid Cells after in Vitro Exposure to Radiation: A Model of Carcinogenic Chromosomal Rearrangement Induced by Ionizing Radiation  

Microsoft Academic Search

Ionizing radiation is a well-known risk factor for thyroid can- cer in human populations. Chromosomal rearrangements in- volving the RET gene, known as RET\\/PTC, are prevalent in thyroid papillary carcinomas from patients with radiation history. We studied the generation of RET\\/PTC in HTori-3 immortalized human thyroid cells exposed to a range of doses of -radiation and harvested 2, 5-6, and

Christy M. Caudill; Zhaowen Zhu; Raffaele Ciampi; James R. Stringer; Yuri E. Nikiforov

59

Radiation Exposure of Uranium Miners.  

National Technical Information Service (NTIS)

Increasing attention has been given, within recent years, to observations that extended exposure in some uranium mines is associated with an increase in lung cancer. Upon approval by the Federal Radiation Council (FRC), its staff carried out a study on th...

C. L. Comar

1968-01-01

60

The Use of Gamma-H2AX as a Biodosimeter for Total-Body Radiation Exposure in Non-Human Primates  

PubMed Central

Background There is a crucial shortage of methods capable of determining the extent of accidental exposures of human beings to ionizing radiation. However, knowledge of individual exposures is essential for early triage during radiological incidents to provide optimum possible life-sparing medical procedures to each person. Methods and Findings We evaluated immunocytofluorescence-based quantitation of ?-H2AX foci as a biodosimeter of total-body radiation exposure (60Co ?-rays) in a rhesus macaque (Macaca mulatta) model. Peripheral blood lymphocytes and plucked hairs were collected from 4 cohorts of macaques receiving total body irradiation doses ranging from 1 Gy to 8.5 Gy. Each cohort consisted of 6 experimental and 2 control animals. Numbers of residual ?-H2AX foci were proportional to initial irradiation doses and statistically significant responses were obtained until 1 day after 1 Gy, 4 days after 3.5 and 6.5 Gy, and 14 days after 8.5 Gy in lymphocytes and until 1 day after 1 Gy, at least 2 days after 3.5 and 6.5 Gy, and 9 days after 8.5 Gy in plucked hairs. Conclusion These findings indicate that quantitation of ?-H2AX foci may make a robust biodosimeter for analyzing total-body exposure to ionizing radiation in humans. This tool would help clinicians prescribe appropriate types of medical intervention for optimal individual outcome. These results also demonstrate that the use of a high throughput ?-H2AX biodosimeter would be useful for days post-exposure in applications like large-scale radiological events or radiation therapy. In addition, this study validates a possibility to use plucked hair in future clinical trials investigating genotoxic effects of drugs and radiation treatments.

Redon, Christophe E.; Nakamura, Asako J.; Gouliaeva, Ksenia; Rahman, Arifur; Blakely, William F.; Bonner, William M.

2010-01-01

61

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.

2012-01-01

62

Sarcoma risk after radiation exposure.  

PubMed

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

Berrington de Gonzalez, Amy; Kutsenko, Alina; Rajaraman, Preetha

2012-01-01

63

Cell type-dependent gene transcription profile in a three-dimensional human skin tissue model exposed to low doses of ionizing radiation: implications for medical exposures.  

PubMed

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. Because of a paucity of direct epidemiological data at very low doses, cancer risk must be estimated from high dose exposure scenarios. However, there is increasing evidence that low and high dose exposures result in different signaling events and may have different response mechanisms than higher doses. We have examined the radiation-induced temporal response after exposure to 10 cGy of an in vitro three dimensional (3D) human skin tissue model using microarray-based transcriptional profiling. Cell type-specific analysis showed significant changes in gene expression with the levels of >1,400 genes altered in the dermis and >400 genes regulated in the epidermis. The two cell layers rarely exhibited overlapping responses at the mRNA level. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) measurements validated the microarray data in both regulation direction and value. Key pathways identified relate to cell cycle regulation, immune responses, hypoxia, reactive oxygen signaling, and DNA damage repair. The proliferation status as well as the expression of PCNA was examined in histological samples. We discuss in particular the role of proliferation, emphasizing how the disregulation of cellular signaling in normal tissue may impact progression toward radiation-induced secondary diseases. PMID:22351304

von Neubeck, Claere; Shankaran, Harish; Karin, Norman J; Kauer, Paula M; Chrisler, William B; Wang, Xihai; Robinson, R Joe; Waters, Katrina M; Tilton, Susan C; Sowa, Marianne B

2012-05-01

64

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

SciTech Connect

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 from high dose exposure scenarios. However, there is increasing evidence that low and high dose exposures result in different signaling events and may have different mechanisms of cancer induction. We have examined the radiation induced temporal response of an in vitro three dimensional (3D) human skin tissue model using microarray-based transcriptional profiling. Our data shows that exposure to 100 mGy of X-rays is sufficient to affect gene transcription. Cell type specific analysis showed significant changes in gene expression with the levels of > 1400 genes altered in the dermis and > 400 genes regulated in the epidermis. The two cell types rarely exhibited overlapping responses at the mRNA level. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) measurements validated the microarray data in both regulation direction and value. Key pathways identified relate to cell cycle regulation, immune responses, hypoxia, reactive oxygen signaling, and DNA damage repair. We discuss in particular the role of proliferation and emphasizing how the disregulation of cellular signaling in normal tissue may impact progression towards radiation induced secondary diseases.

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

2012-04-17

65

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

66

Human responses to the threat of or exposure to ionizing radiation at Three Mile Island, Pennsylvania, and Goiania, Brazil.  

PubMed

The psychological stressors and their aftereffects associated with the Three Mile Island accident, the Goiania, Brazil, cesium-137 accident, and the Abadia, Brazil, storage location are summarized and compared. Cross-cultural comparisons of human responses to ionizing radiation are rare. A multidisciplinary methodological approach to examining the psychological responses to ionizing radiation is even more rare. The psychological, behavioral, neuroendocrine, and cardiovascular results are summarized for Three Mile Island, Goiania, and Abadia. PMID:11873499

Collins, Daniel L

2002-02-01

67

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

68

AIR TOXICS HUMAN EXPOSURE MODELING  

EPA Science Inventory

This project aims to improve the scientific basis for the Environmental Protection Agency's (EPA's) assessments of human exposures to air toxics by developing improved human exposure models. The research integrates the major components of the exposure paradigm, i.e., sources, tr...

69

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

70

Human mammary epithelial cells exhibit a differential p53-mediated response following exposure to ionizing radiation or UV light  

Microsoft Academic Search

The tumor suppressor protein, p53, plays a critical role as a transcriptional activator of downstream target genes involved in the cellular response to DNA damaging agents. We examined the cell cycle checkpoint response of human mammary epithelial cells (HMEC) and their isogenic fibroblast counterparts to ionizing (IR) and ultraviolet (UV) radiation, two genotoxic agents whose DNA damage response pathways involve

Karen M Meyer; Suzanne M Hess; Thea D Tlsty; Steven A Leadon

1999-01-01

71

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

72

Modifications in cell cycle kinetics and in expression of G1 phase-regulating proteins in human amniotic cells after exposure to electromagnetic fields and ionizing radiation.  

PubMed

Low-frequency electromagnetic fields are suspected of being involved in carcinogenesis, particularly in processes that could be related to cancer promotion. Because development of cancer is associated with deregulated cell growth and we previously observed a magnetic field-induced decrease in DNA synthesis [Lange et al. (2002) Alterations in the cell cycle and in the protein level of cyclin D1p, 21CIP1, and p16INK4a after exposure to 50 HZ. MF in human cells. Radiat. Environ. Biophys.41, 131], this study aims to document the influence of 50 Hz, 1 mT magnetic fields (MF), with or without initial gamma-ionizing radiation (IR), on the following cell proliferation-relevant parameters in human amniotic fluid cells (AFC): cell cycle distribution, expression of the G1 phase-regulating proteins Cdk4, cyclin D1, p21CIP1 and p16INK4a, and Cdk4 activity. While IR induced a G1 delay and a dose-dependent G2 arrest, no discernible changes in cell cycle kinetics were observed due to MF exposure. However, a significant decrease in the protein expression of cyclin D1 and an increase in p21CIP1- and p16INK4a-expression could be detected after exposure to MF alone. IR-exposure caused an augmentation of p21CIP1- and p16INK4a- levels as well, but did not alter cyclin D1 expression. A slight diminution of Cdk4 activity was noticed after MF exposure only, indicating that Cdk4 appears not to act as a mediator of MF- or IR-induced changes in the cell cycle of AFC cells. Co-exposure to MF/IR affected neither cell cycle distribution nor protein expression or kinase activity additionally or synergistically, and therefore MF seems not to modify the mutagenic potency of IR. PMID:15377333

Lange, S; Viergutz, T; Simkó, M

2004-10-01

73

Lessons Learned about Human Stem Cell Responses to Ionizing Radiation Exposures: A Long Road Still Ahead of Us  

PubMed Central

Human stem cells (hSC) possess several distinct characteristics that set them apart from other cell types. First, hSC are self-renewing, capable of undergoing both asymmetric and symmetric cell divisions. Second, these cells can be coaxed to differentiate into various specialized cell types and, as such, hold great promise for regenerative medicine. Recent progresses in hSC biology fostered the characterization of the responses of hSC to genotoxic stresses, including ionizing radiation (IR). Here, we examine how different types of hSC respond to IR, with a special emphasis on their radiosensitivity, cell cycle, signaling networks, DNA damage response (DDR) and DNA repair. We show that human embryonic stem cells (hESCs) possess unique characteristics in how they react to IR that clearly distinguish these cells from all adult hSC studied thus far. On the other hand, a manifestation of radiation injuries/toxicity in human bodies may depend to a large extent on hSC populating corresponding tissues, such as human mesenchymal stem cells (hMSC), human hematopoietic stem cells (hHSC), neural hSC, intestine hSC, etc. We discuss here that hSC responses to IR differ notably across many types of hSC which may represent the distinct roles these cells play in development, regeneration and/or maintenance of homeostasis.

Sokolov, Mykyta; Neumann, Ronald

2013-01-01

74

EPA'S HUMAN EXPOSURE MEASUREMENT PROGRAM  

EPA Science Inventory

The goal of NERL's Exposure Research Program is to improve the scientific basis for conducting human exposure assessments that are part of the EPA's risk assessment, risk management and compliance process. Overall, we aim to address aggregate and cumulative exposures that pose...

75

HUMAN EXPOSURE ASSESSMENT USING IMMUNOASSAY  

EPA Science Inventory

The National Exposure Research Laboratory-Las Vegas is developing analytical methods for human exposure assessment studies. Critical exposure studies generate a large number of samples which must be analyzed in a reliable, cost-effective and timely manner. TCP (3,5,6-trichlor...

76

Human radiation tolerance  

NASA Technical Reports Server (NTRS)

The acute radiation syndrome in man is clinically bounded by death at high dose levels and by the prodromal syndrome of untoward physiological effects at minimal levels of clinically effective exposure. As in lower animals, man experiences principally three acute modes of death from radiation exposure (Bond et al., 1965). These are known collectively as the lethal radiation syndromes: central nervous system death, gastrointestinal death, and hematopoietic death. The effect of multiple exposure on lethality, the effect of multiple exposure on hematopoietic recovery, and quantitative aspects of cell and tissue repair are discussed.

Lushbaugh, C. C.

1974-01-01

77

Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Comprehensive progress report, July 1991--June 1992  

SciTech Connect

This project seeks to defining the chromosome segments associated with radiation induced leukemogenesis (treatment-related acute myeloid leukemia, or t-AML). Towards these goals genetic analysis of human chromosomes 5 and 7 continues to investigate correlation of treatment with balanced and unbalanced chromosomal translocations. Progress is being made in cloning the breakpoints in balanced translocations in t-AML, that is to clone the t(9;11) and t(11;19) breakpoints, to clone the t(3;21)(q26;q22) breakpoints and to determine the relationship of these translocations to prior exposure to topoisomerase II inhibitors. 11 figs. 3 figs.

Rowley, J.D.

1992-06-01

78

[Variability of DNA simple sequence repeats in peripheral blood of humans subjected to prolonged exposures of ionizing radiation].  

PubMed

Long-term post-radiation changes in the level of microsatellite DNA polymorphism in peripheral blood of the male "Mayak" employees (Ozyorsk, Russia), who had been exposed to prolonged gamma-irradiation during professional activities, were studied. DNA samples were obtained from the Radiobiology Repository of Human Tissue (Southern-Urals Biophysics Institute FMBA) and used as templates for arbitrarily primed PCR. Comparative analysis of the obtained samples of DNA fragments showed a significant increase in the number of high-molecular fragments and reduction in the number of amplified low molecular weight DNA fragments in comparison with the control. However, a direct correlation of the level of DNA polymorphism with the accumulated total dose of radiation was not found. The study of the polymorphism of microsatellite DNA repeats can be used for qualitative assessment of the levels of genetic variability. PMID:23700832

Lomaeva, M G; Malakhova, L V; Zakharova, M L; Sokolova, S N; Fomenko, L A; Antipova, V N; Soboleva, I Iu; Bezlepkin, V G; Kirillova, E N; Gaziev, A I

2013-01-01

79

A new radiation exposure record system  

SciTech Connect

The Hanford Radiological Records Program (HRRP) serves all Hanford contractors as the single repository for radiological exposure for all Hanford employees, subcontractors, and visitors. The program administers and preserves all Hanford radiation exposure records. The program also maintains a Radiation Protection Historical File which is a historical file of Hanford radiation protection and dosimetry procedures and practices. Several years ago DOE declared the existing UNIVAC mainframe computer obsolete and the existing Occupational Radiation Exposure (ORE) system was slated to be redeveloped. The new system named the Radiological Exposure (REX) System is described in this document.

Lyon, M.; Berndt, V.L.; Trevino, G.W.; Oakley, B.M.

1993-04-01

80

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

81

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

82

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

83

Econometric model for age- and population-dependent radiation exposures  

SciTech Connect

The economic impact associated with ionizing radiation exposures in a given human population depends on numerous factors including the individual's mean economic status as a function age, the age distribution of the population, the future life expectancy at each age, and the latency period for the occurrence of radiation-induced health effects. A simple mathematical model has been developed that provides an analytical methodology for estimating the societal econometrics associated with radiation effects are to be assessed and compared for economic evaluation.

Sandquist, G.M.; Slaughter, D.M. (Univ. of Utah, Salt Lake City (United States)); Rogers, V.C.

1991-01-01

84

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

85

Diagnostic ionizing radiation exposure in premature patients.  

PubMed

Objective:Concern regarding the magnitude and consequences of diagnostic radiation exposure in premature infants in neonatal intensive care units (NICUs) has increased as survival of premature infants has improved. Radiation exposure is not often rigorously monitored in NICU patients. The purpose of this observational study was to quantify the amount of ionizing radiation exposure in infants <33 weeks gestational age and to identify the indications for diagnostic imaging.Study Design:We conducted a retrospective review of 215 premature infants who were <33 weeks gestation and who received central venous line (CVL) placement during their NICU stay during the period from 2006 to 2011. Absorbed ionizing radiation was estimated using the method of Puch-Kapst and colleagues (2009) and compared with recommended radiation exposure limits. All infants were 29.2±2.3 weeks (mean±s.d.) and 1262±433?g birth weight.Result:Subjects received 15±15 radiographs (4.4±2.9 for CVL placement, 5.7±9.8 for gastrointestinal (GI) evaluations and 5.2±9.3 for respiratory indications). Eleven infants (5.1%) received more than the maximum recommended radiation from radiographs (>1000??Sv). Inclusion of fluoroscopic procedures increased to 26 the number of infants (12.1%) who received more than the maximum recommended 1000??Sv.Conclusion:Ionizing radiation exposure that exceeded the recommended maximum in premature infants at high risk for long-term sequelae occurred in 12.1% of infants who were <33 weeks gestation and who were cared for in our NICU over the past 5 years. CVL placement accounted for 22% of this radiation exposure. GI evaluations accounted for the greatest amount of ionizing radiation exposure. We suggest that the increased use of other imaging strategies may reduce total ionizing radiation exposure in this vulnerable population. PMID:24577436

Scott, M V; Fujii, A M; Behrman, R H; Dillon, J E

2014-05-01

86

Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles  

PubMed Central

Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed.

2011-01-01

87

Fetal radiation exposure: Is monitoring really needed?  

PubMed

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

2013-08-16

88

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.

Di Leo, Milena; Arcidiacono, Paolo Giorgio

2013-01-01

89

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

90

A human exposure modelling method for HF transmitter sites  

Microsoft Academic Search

This paper continues previous research into radiation hazard assessment of BBC World Service HF transmission sites in accordance with ICNIRP guidelines. It focuses on possible methodologies for the analysis of human exposure from such sites. A high resolution full body human voxel phantom from the `Virtual Family' was illuminated using plane-wave radiation, and being positioned in the near-field zone of

Ying Fu; Mike Hate; Doug Fisher; Jeff McCalla; Greg Cook; Richard Langley; Jonathan Rigelsford

2010-01-01

91

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...

92

Environmental radiation exposure rate in Louisiana  

Microsoft Academic Search

The environmental radiation exposure rate has been measured using thermoluminescent dosimetry at 26 monitoring stations in Louisiana over a period of 2 yr. Sets of LiF dosimeters that are essentially tissue equivalent in their energy response characteristics were left at each station for 90 d, replaced, and the exposure they received determined. The chips were exposed to a standard source

J. N. Beck; D. F. Keeley; J. R. Meriwether; R. H. Thompson

2009-01-01

93

70 FR 22828 - Occupational Exposure to Ionizing Radiation  

Federal Register 2010, 2011, 2012, 2013

...exposure, such as exposure assessment and...address worker exposure to occupational...OSHA Office of Communications, Room N-3647...ionizing radiation exposure 1. Natural sources...products D. Health effects II. Regulatory...responsible for worker exposures to ionizing...

2005-05-03

94

Inhibition of postbinding target cell lysis and of lymphokine-induced enhancement of human natural killer cell activity by in vitro exposure to ultraviolet B radiation  

SciTech Connect

In vitro exposure of human peripheral blood mononuclear cells (PBMC) to ultraviolet B (uvB) radiation has been shown to inhibit natural killer (NK) cell-mediated cytotoxicity in a dose-dependent fashion. The purpose of this study was to examine the manner by which uvB produced these deleterious effects. Inhibition of NK activity was not due to lethal injury to NK cells since the viability of cell populations enriched for NK activity was greater than 90% with the uvB doses employed. uvB appeared to directly affect NK cells since procedures which removed suppressor mechanisms, such as removal of monocytes and pharmacologic inhibition of the cyclooxygenase pathway, failed to reverse the response. Furthermore, no suppression of activity of unirradiated NK cells could be produced by coincubation of unirradiated NK cells with uv-irradiated NK cells. When the single cell assay for binding and killing was employed to determine at which stage in the lytic sequence inhibition occurred, it was found that binding was normal but lysis of bound targets and the recycling capacity of active NK cells were markedly reduced. At uvB doses above 50 J/m2, both interferon alpha (IFN-alpha) and interleukin 2 (IL-2) were ineffective in augmenting NK cell-mediated cytotoxic reactions after cells had been irradiated with uvB. Furthermore, incubation of NK cells with IFN-alpha prior to irradiation failed to protect against the inhibitory effects. These studies provide evidence that in vitro exposure of NK cells to uvB radiation inhibits their function by a direct nonlethal effect and that this inhibition occurs selectively at the postbinding stage of target cell lysis.

Elmets, C.A.; Larson, K.; Urda, G.A.; Schacter, B.

1987-01-01

95

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.

Utell, M J; Frampton, M W

2000-01-01

96

Ultrasensitive Human Radiation Dosimetry  

NASA Technical Reports Server (NTRS)

The problem we are addressing concerns the astronauts, and their exposure to radiation during spaceflight. The amount of this radiation is a variable depending on solar events and orbital characteristics. Our goal is to measure the total integrated quantity of radiation damage to the cell nucleus in astronauts or other people exposed to radiation. In my lab, we are turning up the microscope from the level of the chromosome, about eight orders of magnitude, to the molecular level. It is well known that radiation causes DNA and chromosome damage. We are developing methods to measure a specific molecular lesion. The lesion that we have selected to measure is thymidine diol, which is created by hydroxyl radicals adding across the 5.6 double bond of thymidine in DNA.

Hammen, Richard

1985-01-01

97

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

98

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 (...

99

Human exposure to bisphenol A  

Microsoft Academic Search

Bisphenol A (BPA), 2,2-bis(4-hydroxyphenyl)propane, is made by combining acetone and phenol. It has estrogenic activity and is acutely toxic to aquatic organisms. BPA is used mainly as a material for the production of epoxy resins and polycarbonate plastics. Due to an increase in products based on epoxy resins and polycarbonate plastics, human exposure to BPA has increased. The environment (aquatic

Jeong-Hun Kang; Fusao Kondo; Yoshiki Katayama

2006-01-01

100

Monitoring phthalate exposure in humans  

Microsoft Academic Search

The dialkyl- or alkyl\\/aryl esters of 1,2-benzenedicarboxylic acid, commonly known as phthalates, are high-production-volume synthetic chemicals and ubiquitous environmental contaminants because of their use in plastics and other common consumer products. Di-(2-ethylhexyl) phthalate (DEHP) is the most abundant phthalate in the environment. Humans are exposed to these compounds through ingestion, inhalation, and dermal exposure for their whole lifetime, since the

Giuseppe Latini

2005-01-01

101

Clinical translation of human microRNA 21 as a potential biomarker for exposure to ionizing radiation.  

PubMed

This study investigated to what extent the serum microRNA 21 (miR-21) level alters in response to ionizing radiation (IR). Initially, we evaluated the appropriateness of our RNA extraction efficiency and microRNA assay in serum, and then investigated the serum miR-21 level in 4 patients with breast cancer in 4 stages: pre- and postoperation, at the beginning radiotherapy, and after 25 sessions of radiotherapy with a total of 50 Gy irradiation, as well as in 20 healthy volunteers. The initial analysis showed the appropriateness of our RNA extraction efficiency and microRNA assay in serum for identifying people exposed to IR. We then analyzed the serum miR-21 level in another group of 40 patients with breast cancer before and after radiotherapy. During our large-scale analysis, the miR-21 level before radiotherapy was comparable with healthy volunteers (P = 0.10) and increased significantly after radiotherapy (P < 0.001)-an indication that this could discriminate irradiated patients from nonirradiated ones with high specificity (75%) and sensitivity (80%). According to this study, serum miR-21 has the potential to be used as a biomarker for the identification of people exposed to ionizing radiation. PMID:24518062

Halimi, Mohammad; Parsian, Hadi; Asghari, S Mohsen; Sariri, Reyhaneh; Moslemi, Dariush; Yeganeh, Farshid; Zabihi, Ebrahim

2014-06-01

102

Operational Prototype Development of a Global Aircraft Radiation Exposure Nowcast  

NASA Astrophysics Data System (ADS)

Galactic cosmic rays (GCR) and solar energetic particles (SEP) are the primary sources of human exposure to high linear energy transfer (LET) radiation in the atmosphere. High-LET radiation is effective at directly breaking DNA strands in biological tissue, or producing chemically active radicals in tissue that alter the cell function, both of which can lead to cancer or other adverse health effects. A prototype operational nowcast model of air-crew radiation exposure is currently under development and funded by NASA. The model predicts air-crew radiation exposure levels from both GCR and SEP that may accompany solar storms. The new air-crew radiation exposure model is called the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model. NAIRAS will provide global, data-driven, real-time exposure predictions of biologically harmful radiation at aviation altitudes. Observations are utilized from the ground (neutron monitors), from the atmosphere (the NCEP Global Forecast System), and from space (NASA/ACE and NOAA/GOES). Atmospheric observations characterize the overhead mass shielding and the ground-and space-based observations provide boundary conditions on the incident GCR and SEP particle flux distributions for transport and dosimetry calculations. Radiation exposure rates are calculated using the NASA physics-based HZETRN (High Charge (Z) and Energy TRaNsport) code. An overview of the NAIRAS model is given: the concept, design, prototype implementation status, data access, and example results. Issues encountered thus far and known and/or anticipated hurdles to research to operations transition are also discussed.

Mertens, Christopher; Kress, Brian; Wiltberger, Michael; Tobiska, W. Kent; Bouwer, Dave

103

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

104

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.

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

2008-01-01

105

Radiation metabolomics. 1. Identification of minimally invasive urine biomarkers for gamma-radiation exposure in mice.  

PubMed

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 gamma-radiation biodosimetry in a mouse model. Mice were gamma-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 beta-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 gamma 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

2008-07-01

106

Mobile phone radiation might alter protein expression in human skin  

Microsoft Academic Search

BACKGROUND: Earlier we have shown that the mobile phone radiation (radiofrequency modulated electromagnetic fields; RF-EMF) alters protein expression in human endothelial cell line. This does not mean that similar response will take place in human body exposed to this radiation. Therefore, in this pilot human volunteer study, using proteomics approach, we have examined whether a local exposure of human skin

Anu Karinen; Sirpa Heinävaara; Reetta Nylund; Dariusz Leszczynski

2008-01-01

107

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

108

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...

109

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.

Fukumoto, Risaku; Kiang, Juliann G.

2014-01-01

110

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

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 (IC(50) ?=? 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

2011-09-01

111

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

112

[New approaches to diagnostics and identification of possible damages in normal humans under the conditions of microgravity and exposure to low doses of radiation].  

PubMed

The issues of radiation risk evaluation were addressed in the investigation of cytogenetic and molecular-biological changes in lymphocytes of cosmonauts and pilots of high-altitude airplanes. The goal was to determine individual sensitivity to the flight conditions and an additional factor (lymphocyte exposure to 1 Gy in situ), and adaptability as an index of induction of cell and organism resistance to extreme conditions. PMID:19055004

Voronkov, Iu I; Pelevina, I I; Tsetlin, V V; Osipov, A N; Riabchenko, N I; Serebriany?, A M; Gotlib, V Ia; Vorob'eva, N Iu; Antoshina, M M; Bondarenko, V A

2008-01-01

113

Ionizing radiation exposure of the population of the United States  

SciTech Connect

The NCRP has recognized for some time the need for a clear assessment of the magnitude of the doses from various sources of radiation to which the population of the U.S. is exposed. In anticipation of the need to gather basic data for input into this process five assessment committees, each addressing a different source category, were established in 1971. NCRP reports assessing exposures from natural background and from consumer products were produced (NCRP 1975, 1977), but no attempt was made to develop a comprehensive account of all sources of exposure. In 1985, the NCRP reconsidered its overall effort in this area and, with the further support and stimulation of the Committee on Interagency Radiation Research and Policy Coordination (Office of Science and Technology Policy, Executive Office of the President of the United States), undertook to evaluate the exposure of the U.S. population from all sources. The sources involved are of three general types, those of natural origin, unperturbed by human activities, those of natural origin but affected by human activities (termed enhanced natural sources), and man-made sources. Natural sources include cosmic radiation from outer space, terrestrial radiation from natural radioactive sources in the ground, radiations from radionuclide naturally present in the body and inhaled and ingested radionuclides of natural origin. A variety of exposures results from man-made materials and devices, e.g. radipharmaceuticals and x rays in medicine, and consumer products containing radioactive materials such as some smoke detectors or static eliminators. Exposures may also result from episodic events due to man's activities, such as atmospheric nuclear weapons testing, accidents in nuclear power plants, etc.

Not Available

1987-01-01

114

Exposure to radio frequency radiation emitted by cell phone and mortality in chick embryos (Gallus domesticus)  

Microsoft Academic Search

The rapidly increasing use of cell phones since late 1990s has caused a general concern on the possible hazardous health effects of exposure to radio frequency electro-magnetic radiation (EMR) emitted by them. While considering the bio- logical effects of EMR on the human body, its intensity, frequency of radiation and duration of exposure are important determinants. Many researchers have reported

I. V. Ingole; S. K. Ghosh

2006-01-01

115

Radiation exposure during continuous and pulsed fluoroscopy.  

PubMed

Abstract Background and Purpose: Previous studies using pulsed fluoroscopy have shown variable effects on radiation exposure because of the ramp and trail effect in older C-arm systems. This study compares radiation delivered in pulsed and continuous modalities using a modern C-arm system. Materials and Methods: Thermoluminescent dosimeters (TLDs) positioned in three body locations directly measured radiation dose during simulated ureteroscopy. Thirty pedal activations were administered using a pulsed or continuous mode to visualize an implanted guidewire and a radiopaque stone. TLD absorbed radiation and image quality were compared between imaging modes. Results: Pulsed fluoroscopy delivered less radiation compared with continuous fluoroscopy at each site: Anterior skin (0.10 vs 0.26?mGy, P<0.001), kidney (0.15 vs 0.40?mGy, P<0.001), and posterior skin (0.92 vs 2.62?mGy, P<0.001). Mean fluoroscopy time differed between continuous and pulsed modes (12.5 vs 3.0 seconds; P<0.001). Fluoroscopy time positively correlated with radiation exposure at all sites: Anterior skin (0.017?mGy/s, R(2)=0.90), left kidney (0.026?mGy/s, R(2)=0.96), and posterior skin (0.18?mGy/sec, R(2)=0.98). When evaluated by blinded urologists, 100% of reviewers felt pulsed images were adequate to identify guidewire position and 90.5% felt pulsed images were adequate for stone localization. Conclusion: Pulsed fluoroscopy reduced fluoroscopy time by 76% and radiation dose by 64% compared with continuous fluoroscopy. Pulsed fluoroscopy images were adequate for most tasks of ureteroscopy and should be considered for reduction of radiation during ureteroscopy. PMID:22966826

Smith, Damien L; Heldt, Jonathan P; Richards, Gideon D; Agarwal, Gautum; Brisbane, Wayne G; Chen, Catherine J; Chamberlin, Joshua D; Baldwin, D Duane

2013-03-01

116

Environmental Radioactivity and Radiation Exposure. Annual Report 1980.  

National Technical Information Service (NTIS)

The contribution of exposures from natural radiation sources to the genetically significant dose (GSD) is approximately 1,1 Millisievert (110 Millirem). The contribution of medical radiation exposure to the GSD amounts to about 0.5 Millisievert (50 Millir...

1983-01-01

117

A single exposure of solar simulated radiation suppresses contact hypersensitivity responses both locally and systemically in humans: quantitative studies with high-frequency ultrasound  

Microsoft Academic Search

Ultraviolet radiation (UVR)-induced suppression of cutaneous cell-mediated immunity plays an important role in the development of photocarcinogenesis in the mouse and a similar role is suspected in humans. Cell-mediated immunity is readily tested in vivo by measuring the contact hypersensitivity (CHS) response to topically applied haptens. CHS in humans is usually determined clinically, with a subjective scoring system. However, these

Deirdre A. Kelly; Susan L. Walker; Jane M. McGregor; Antony R. Young

1998-01-01

118

OUTDOOR VS. HUMAN EXPOSURE: NERL PM EXPOSURE PANEL STUDIES  

EPA Science Inventory

An association has been demonstrated between ambient particulate matter (PM 2.5 and PM 10) concentrations and human morbidity/mortality. However, little is known regarding the most important sources of PM exposure, interpersonal and intrapersonal variability in exposure, and the...

119

The Human Salivary Proteome is Radiation Responsive.  

PubMed

In the event of a nuclear incident in a heavily populated area, the surge in demand for medical evaluation will likely overwhelm our emergency care system, compromising our ability to care for victims with life-threatening injuries or exposures. Therefore, there exists a need for a rapidly deployable biological assay for radiation exposure that can be performed in the field by individuals with little to no medical training. Saliva is an attractive biofluid for this purpose, due to the relative ease of its collection and the wide array of biomolecules it contains. To determine whether the human salivary proteome is responsive to ionizing radiation exposure, we characterized the abundances of salivary proteins in humans before and after total body irradiation. Using an assay panel targeting 90 analytes (growth factors, chemokines and cytokines), we identified proteins that were significantly radiation responsive in human saliva. The responses of three proteins (monocyte chemo-attractant protein 1, interleukin 8 and intercellular adhesion molecule 1) were confirmed using independent immunoassay platforms and then verified and further characterized in 130 saliva samples from a completely independent set of 38 patients undergoing total body irradiation. The results demonstrate the potential for detecting radiation exposure based on analysis of human saliva. PMID:24720749

Moore, Heather D; Ivey, Richard G; Voytovich, Uliana J; Lin, Chenwei; Stirewalt, Derek L; Pogosova-Agadjanyan, Era L; Paulovich, Amanda G

2014-05-01

120

Ultraviolet Radiation Exposure from UV-Transilluminators  

Microsoft Academic Search

UV-transilluminators use ultraviolet radiation (UVR) to visualize proteins, DNA, RNA, and their precursors in a gel electrophoresis procedure. This study was initiated to evaluate workers' exposure to UVR during their use of UV-transillumin- ators. The levels of irradiance of UV-A, UV-B, and UV-C were determined for 29 UV-transilluminators at arbitrary measuring locations of 6, 25, 62, and 125 cm from

Farhang Akbar-Khanzadeh; Mahdi Jahangir-Blourchian

2005-01-01

121

TELOMERASE AND CHRONIC ARSENIC EXPOSURE IN HUMANS  

EPA Science Inventory

Arsenic exposure has been associated with increased risk of skin, lung and bladder cancer in humans. The mechanisms of carcinogenesis are not well understood. Telomerase, a ribonucleoprotein containing human telomerase reverse transcriptase (hTERT), can extend telomeres of eukary...

122

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...

123

Thyroid cancer risk from exposure to ionizing radiation: a case study in the comparative potency model  

SciTech Connect

Considerable controversy exists about the relative risk of thyroid cancer following exposure to external radiation compared to the risk after exposure to internally deposited /sup 131/I. The human epidemiological data are equivocal, and studies are not directly comparable owing to differing ages at exposure, dose ranges, and periods of follow-up. Limited experimental data at low dose ranges support the hypothesis of equal potency in animals. This report utilizes a relative potency model to reconcile data from different sources, and to provide an estimate of thyroid cancer risk following human exposure to /sup 131/I. We utilize data from epidemiological studies of external radiation and /sup 131/I exposure in humans and data from an experimental animal study. This analysis shows that the data provide no compelling evidence to suggest that the risks accompanying external radiation or /sup 131/I exposure are different.

Laird, N.M.

1987-09-01

124

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...

125

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

126

Human Exposure to Urban Air Pollution  

Microsoft Academic Search

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

Carl-Elis Boström; Jacob Almén; Bengt Steen; Roger Westerholm

127

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

128

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

129

HUMAN EXPOSURE MEASUREMENTS - CHILDREN'S FOCUS  

EPA Science Inventory

In support of the Food Quality Protection Act of 1996, research under this task is designed to identify those pesticides, pathways, and activities that represent the highest potential exposures to children and to determine the factors that influence these exposures. The research...

130

Multilayer reflectance during exposure to EUV radiation  

NASA Astrophysics Data System (ADS)

Mo/S multilayer mirrors have been exposed to intense monochromatic EUV radiation in order to investigate a possible deterioration of the mirror reflectance under different vacuum conditions. Power densities up to 3 mW/mm2 were applied at the PB undulator beamline at BESSY II, applying a hydrocarbon enriched vacuum. The mirror reflectance has been monitored in situ during several hours of exposure. Vacuum pressures of 3 X 10-8 mbar (without hydrocarbons) and 10-7 mbar (with hydrocarbons) at EUV intensities of 3 mW/mm2, respectively 0.2 mW/mm2 have been applied. The reflectance of the mirrors decreased when exposed to EUV radiation in hydrocarbon enriched vacuum, while no loss in reflectance was observed when no hydrocarbons were added to the vacuum. Ozone-cleaning experiments, using UV produced ozone from air at atmospheric pressure, were performed and show that Mo/S mirrors do not suffer from prolonged exposure to ozone.

Oestreich, Sebastian; Klein, Roman; Scholze, Frank; Jonkers, Jeroen; Louis, Eric; Yakshin, Andrey E.; Goerts, Peter C.; Ulm, Gerhard; Haidl, Markus; Bijkerk, Fred

2000-11-01

131

Radiation Hazards and Countermeasures for Human Space Flight  

NASA Technical Reports Server (NTRS)

The protection of astronauts from the hazards of ionizing radiation in space is a moral and legal obligation of NASA. If there are to be manned deep-space missions, means must be found to provide this protection. There are two parts to providing this protection: understanding the effects of space radiation on humans so that radiation exposure limits can be established; and developing countermeasures so that exposures can be kept below these limits. This talk will cover both parts of this problem.

Adams, James

2004-01-01

132

Astronaut radiation exposure in low-earth orbit. Part 1. Galactic cosmic radiation  

Microsoft Academic Search

In recent years, there has been increasing concern about the radiation doses that will be suffered by astronauts on present-day and future space missions. In order to characterize radiation exposure risks on space missions one requires models of space-radiation environments, codes for transporting the components of ionizing radiation, and procedures for assessing radiation risks of a given exposure. To verify

Letaw

1988-01-01

133

Radiation exposure estimates from extremely energetic solar proton events  

NASA Astrophysics Data System (ADS)

Historically, in order to assess absorbed dose and dose equivalent exposures in solar particle events (SPEs), the radiation physics community has often used an exponential fit in rigidity (Malitson and Webber, 1963) to extrapolate the proton spectra from available measurements at 10-100 MeV to higher energies. Similarly, King [1974] used an exponential in energy to describe the August 1972 SPEs. These exponential forms may be adequate for lightly shielded systems. But for "storm shelters", with shielding thicknesses greater that 10 g/cm2 aluminumequivalent, the assumption about the spectral form beyond 100 MeV is a potentially critical systematic uncertainty in estimates of the radiation exposure. For the most important SPEs in the historical record, ground-based neutron monitor (NM) data can serve to define the spectral shape by providing proton fluence measurements beyond 500 MeV. Tylka and Dietrich (this conference, Session D23) have derived proton spectra from NM data for 38 of the largest of these so-called Ground Level Enhanced (GLE) SPEs that have been observed since 1956. Their analyses also combine these NM measurements with lower-energy data from satellites and other sources. In this paper we use these new results to take a fresh look at the radiation exposure estimates from several interesting GLEs, including the August 1972 events. Using the NASA Langley Research Center HZETRN 2005 high energy particle transport/dose code, depth-dose results are presented and compared using both (a) exponential spectra, as determined solely from data below 100 MeV and (b) the complete spectrum, including the high energies derived from NM measurements. Since SPEs represent the single most important source of acute radiation exposure to humans and space systems in deep space, these results can serve as guidance for mission planning and crew health protection. This work has been supported in part by the Office of Naval Research and by NASA DPR NNG06EC55I.

Atwell, William; Tylka, Allan J.; Dietrich, William F.; Badavi, Francis

134

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 ...

135

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...

136

Human EMF Exposure Health Hazard Range Modeling  

Microsoft Academic Search

Former research brought standards that define electromagnetic field strength safety limits regarding human health in order to prevent harmful exposures. All wireless devices must comply those regulations so there is a need for electromagnetic exposure inspection. In broader analysis it is reasonable to apply more complex, but consistent procedure for harmful area valuation by determining the compliance boundary. It's very

A. Sarolic; B. Modlic; G. Sisul; M. Cvitkovic

2008-01-01

137

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...

138

Human Exposure to Dioxin from Combustion Sources.  

National Technical Information Service (NTIS)

Because of their extreme toxicity, much concern and debate has arisen about the nature and extent of human exposure to dioxin. Since municipal solid waste (MSW) incinerators are known to emit polychorinated dibenzo-p-dioxins (PCDDs) and polycholorinated d...

H. A. Hattemer-Frey C. C. Travis

1988-01-01

139

Community Engagement in Observational Human Exposure Studies  

EPA Science Inventory

Although observational human exposure studies do not deliberately expose participants to chemicals or environmental conditions, merely involving people as research participants and conducting research inside homes raises ethical issues. Community engagement offers a promising st...

140

Radiation exposure and air travel: should we worry?  

PubMed

With the federal government introducing new advanced imaging scanners at airports, the traveling public has become concerned about the radiation exposure they may receive when passing through scanners as well as during flight. This article offers a primer on radiation and the extent to which exposure from various sources can affect health. It also provides advice for physicians whose patients may have concerns about radiation exposure during air travel. PMID:21736206

Hansen, Ronnell; Hansen, Elisa

2011-06-01

141

Latency Period of Thyroid Neoplasia After Radiation Exposure  

PubMed Central

Objective: To determine the temporal sequence for developing benign and malignant thyroid neoplasms after radiation. Summary Background Data: Therapeutic radiation is associated with thyroid neoplasms in humans and animals. Some question whether thyroid cancers develop de novo or from benign thyroid neoplasms. Little information, however, is available concerning the time to development of benign and malignant thyroid neoplasms after radiation exposure. Methods: We retrospectively analyzed the records of 171 consecutive patients who had a history of exposure to radiation and were treated surgically at University of California, San Francisco-affiliated hospitals for thyroid neoplasms between 1960 and 1999. Results: There were 66 men and 105 women aged 9 to 80 years (mean, 47.0 years). One hundred patients had benign and 71 had malignant tumors (58 papillary cancers, 10 follicular cancers, 1 Hurthle cell cancer, 1 medullary cancer, and 1 carcinosarcoma). The mean latency period for benign tumors was longer than that for malignant lesions (mean, 34.1 and 28.4 years, P = 0.018; median, 38.0 years and 30.0 years, P = 0.001). Follicular carcinomas developed sooner (mean, 20.5 years; median, 20 years) than did follicular adenomas (mean, 35.3 years; median, 36.5 years; P = 0.003, P = 0.0009). Patients with papillary thyroid cancers presenting as occult papillary cancers (<1 cm) and as a dominant nodule had similar latency periods (mean, 34.0 and 28.0 years P = 0.29; median, 37.5 and 30.5 years, P = 0.09), respectively. Conclusion: Although there could be selection bias regarding referral of patients, our data document that malignant thyroid tumors after radiation exposure, including follicular carcinomas, present earlier than do benign thyroid tumors. Occult and manifest papillary thyroid cancers present at about the same time interval after radiation exposure. Our findings question whether benign thyroid neoplasms progress to malignant thyroid neoplasms and that most occult thyroid cancers do not progress to malignant thyroid cancers in radiation-exposed patients.

Kikuchi, Shoichi; Perrier, Nancy D.; Ituarte, Philip; Siperstein, Allan E.; Duh, Quan-Yang; Clark, Orlo H.

2004-01-01

142

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...

143

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...

144

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.

Lioy, P J

1995-01-01

145

Effects of high vs low-level radiation exposure  

SciTech Connect

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

Bond, V.P.

1983-01-01

146

[Exposure to noise, vibration and radiation in Cracow].  

PubMed

The problems are discussed connected with exposure to noise, vibration and ionizing radiation. In Cracow traffic and industrial noise is particularly troublesome. The greatest intensity of traffic noise is in the old part of the city and noise level caused by city transport is from 65 to 85 dB/A. Among the industrial sources of noise the highest intensity is in the Lenin Steel Plant, Leg Electrothermal Plant, and Solway Soda Works. Vibration and ionizing radiation resulting from the industrial activities are a considerable risk for human health in the Cracow area. The building materials in construction (including apartment houses) have sometimes a high radioactivity, e.g. dust-slag hollow bricks. The need is stressed for solving, if possible, the problem of noise, especially traffic noise, which is connected with considerable financial costs; the question of using materials of high radioactivity for building purposes should be also resolved. PMID:2244172

Jarosz, A; Zo?dak, M

1990-01-01

147

Human mercury exposure and effects in Europe.  

PubMed

The effects of human exposure to mercury (Hg) and its compounds in Europe have been the focus of numerous studies that differed in their design, including recruiting different population groups at different levels of exposure and using different protocols and recruitment strategies. The objective of the present study was to review current studies of Hg exposure in Europe, taking into account the potential routes of Hg exposure, actual Hg exposure levels assessed by different biomarkers, and the effects of Hg to Europeans. All published studies from 2000 onward were reviewed, and exposure and effects studies were compared with known Hg levels in environmental compartments by mapping the various population groups studied and taking into account known sources of Hg. A study of the spatial distribution trends confirmed that the highest exposure levels to Hg, mostly as methylmercury (MeHg), are found in coastal populations, which consume more fish than inland populations. Fewer studies addressed exposure to elemental Hg through inhalation of Hg in air and inorganic Hg in food, particularly in highly contaminated areas. Overall, at the currently low exposure levels of Hg prevalently found in Europe, further studies are needed to confirm the risk to European populations, taking into consideration exposure to various Hg compounds and mixtures of stressors with similar end-points, nutritional status, and a detailed understanding of Hg in fish present in European markets. Environ Toxicol Chem 2014;33:1259-1270. © 2013 SETAC. PMID:24375779

Višnjevec, Ana Miklav?i?; Kocman, David; Horvat, Milena

2014-06-01

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.

2014-01-01

149

Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Comprehensive progress report, July 1991--June 1994  

SciTech Connect

This comprehensive progress report provides a synopsis of major research accomplishments during the years of 1991-1994, including the technical aspects of the project. The objectives and accomplishments are as follows: 1. Defining the chromosome segments associated with radiation and chemically-induced leukemogenesis (treatment-related acute myeloid leukemia, t-AML); A. Continued genetic analysis of chromosomes 5 and 7, B. Correlation of treatment with balanced and unbalanced translocations. 2. Cloning the breakpoints in balanced translocations in t-AML; A. Clone the t(9;11) and t(11;19) breakpoints, B. Clone the t(3,21)(q26,q22) breakpoint, C. Determine the relationship of these translocations to prior exposure to topoisomerase II inhibitors. 3. Compare the breakpoint junctions in patients who have the same translocations in t-AML and AML de novo. 4. Map the scaffold attachment regions in the genes that are involved in balanced translocations in t-AML. Plans for the continuation of present objectives and possible new objectives in consideration of past results are also provided.

Rowley, J.D.

1994-06-01

150

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.

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

2012-01-01

151

DNA damage responses following exposure to modulated radiation fields.  

PubMed

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

152

21st Century Lunar Exploration: Advanced Radiation Exposure Assessment  

NASA Technical Reports Server (NTRS)

On January 14, 2004 President George W Bush outlined a new vision for NASA that has humans venturing back to the moon by 2020. With this ambitious goal, new tools and models have been developed to help define and predict the amount of space radiation astronauts will be exposed to during transit and habitation on the moon. A representative scenario is used that includes a trajectory from LEO to a Lunar Base, and simplified CAD models for the transit and habitat structures. For this study galactic cosmic rays, solar proton events, and trapped electron and proton environments are simulated using new dynamic environment models to generate energetic electron, and light and heavy ion fluences. Detailed calculations are presented to assess the human exposure for transit segments and surface stays.

Anderson, Brooke; Clowdsley, Martha; Wilson, John; Nealy, John; Luetke, Nathan

2006-01-01

153

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

154

[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

155

Effect of “Noisy” sun conditions on aircrew radiation exposure  

NASA Astrophysics Data System (ADS)

In computer codes used to estimate the aircrew radiation exposure from galactic cosmic radiation, a quiet sun model is usually assumed. A revised computer code (PCAIRE ver. 8.0f) is used to calculate the impact of noisy sun conditions on aircrew radiation exposure. The revised code incorporates the effect of solar storm activity, which can perturb the geomagnetic field lines, altering cutoff rigidities and hence the shielding capability of the Earth's magnetic field. The effect of typical solar storm conditions on aircrew radiation exposure is shown to be minimal justifying the usual assumptions.

Lewis, B. J.; Green, A. R.; Bennett, L. G. I.

2009-07-01

156

DOE occupational radiation exposure. Report 1992--1994  

SciTech Connect

The DOE Occupational Radiation Exposure Report, 1992-1994 reports occupational radiation exposures incurred by individuals at US Department of Energy (DOE) facilities from 1992 through 1994. This report includes occupational radiation exposure information for all DOE employees, contractors, subcontractors, and visitors. This information is analyzed and trended over time to provide a measure of the DOE`s performance in protecting its workers from radiation. Occupational radiation exposure at DOE has been decreasing over the past 5 years. In particular, doses in the higher dose ranges are decreasing, including the number of doses in excess of the DOE limits and doses in excess of the 2 rem Administrative Control Level (ACL). This is an indication of greater attention being given to protecting these individuals from radiation in the workplace.

NONE

1997-05-01

157

Nuclear Fragmentation Processes Relevant for Human Space Radiation Protection  

Microsoft Academic Search

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

Zi-Wei Lin

2007-01-01

158

Photoprotection of human skin beyond ultraviolet radiation.  

PubMed

Photoprotection of human skin by means of sunscreens or daily skin-care products is traditionally centered around the prevention of acute (e.g. sunburn) and chronic (e.g. skin cancer and photoaging) skin damage that may result from exposure to ultraviolet rays (UVB and UVA). Within the last decade, however, it has been appreciated that wavelengths beyond the ultraviolet spectrum, in particular visible light and infrared radiation, contribute to skin damage in general and photoaging of human skin in particular. As a consequence, attempts have been made to develop skin care/sunscreen products that not only protect against UVB or UVA radiation but provide photoprotection against visible light and infrared radiation as well. In this article, we will briefly review the current knowledge about the mechanisms responsible for visible light/infrared radiation-induced skin damage and then, based on this information, discuss strategies that have been successfully used or may be employed in the future to achieve photoprotection of human skin beyond ultraviolet radiation. In this regard we will particularly focus on the use of topical antioxidants and the challenges that result from the task of showing their efficacy. PMID:24433486

Grether-Beck, Susanne; Marini, Alessandra; Jaenicke, Thomas; Krutmann, Jean

2014-01-01

159

Occupational Exposure to Natural Sources of Ionising Radiation in Ireland  

NASA Astrophysics Data System (ADS)

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

2008-08-01

160

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

161

Low-dose radiation exposure induces a HIF-1-mediated adaptive and protective metabolic response.  

PubMed

Because of insufficient understanding of the molecular effects of low levels of radiation exposure, there is a great uncertainty regarding its health risks. We report here that treatment of normal human cells with low-dose radiation induces a metabolic shift from oxidative phosphorylation to aerobic glycolysis resulting in increased radiation resistance. This metabolic change is highlighted by upregulation of genes encoding glucose transporters and enzymes of glycolysis and the oxidative pentose phosphate pathway, concomitant with downregulation of mitochondrial genes, with corresponding changes in metabolic flux through these pathways. Mechanistically, the metabolic reprogramming depends on HIF1?, which is induced specifically by low-dose irradiation linking the metabolic pathway with cellular radiation dose response. Increased glucose flux and radiation resistance from low-dose irradiation are also observed systemically in mice. This highly sensitive metabolic response to low-dose radiation has important implications in understanding and assessing the health risks of radiation exposure. PMID:24583639

Lall, R; Ganapathy, S; Yang, M; Xiao, S; Xu, T; Su, H; Shadfan, M; Asara, J M; Ha, C S; Ben-Sahra, I; Manning, B D; Little, J B; Yuan, Z-M

2014-05-01

162

Analysis of white blood cell counts in mice after gamma- or proton-radiation exposure.  

PubMed

In the coming decades human space exploration is expected to move beyond low-Earth orbit. This transition involves increasing mission time and therefore an increased risk of radiation exposure from solar particle event (SPE) radiation. Acute radiation effects after exposure to SPE radiation are of prime importance due to potential mission-threatening consequences. The major objective of this study was to characterize the dose-response relationship for proton and ? radiation delivered at doses up to 2 Gy at high (0.5 Gy/min) and low (0.5 Gy/h) dose rates using white blood cell (WBC) counts as a biological end point. The results demonstrate a dose-dependent decrease in WBC counts in mice exposed to high- and low-dose-rate proton and ? radiation, suggesting that astronauts exposed to SPE-like radiation may experience a significant decrease in circulating leukocytes. PMID:21476859

Maks, Casey J; Wan, X Steven; Ware, Jeffrey H; Romero-Weaver, Ana L; Sanzari, Jenine K; Wilson, Jolaine M; Rightnar, Steve; Wroe, Andrew J; Koss, Peter; Gridley, Daila S; Slater, James M; Kennedy, Ann R

2011-08-01

163

Analysis of White Blood Cell Counts in Mice after Gamma- or Proton-Radiation Exposure  

PubMed Central

In the coming decades human space exploration is expected to move beyond low-Earth orbit. This transition involves increasing mission time and therefore an increased risk of radiation exposure from solar particle event (SPE) radiation. Acute radiation effects after exposure to SPE radiation are of prime importance due to potential mission-threatening consequences. The major objective of this study was to characterize the dose–response relationship for proton and ? radiation delivered at doses up to 2 Gy at high (0.5 Gy/min) and low (0.5 Gy/h) dose rates using white blood cell (WBC) counts as a biological end point. The results demonstrate a dose-dependent decrease in WBC counts in mice exposed to high- and low-dose-rate proton and ? radiation, suggesting that astronauts exposed to SPE-like radiation may experience a significant decrease in circulating leukocytes.

Maks, Casey J.; Wan, X. Steven; Ware, Jeffrey H.; Romero-Weaver, Ana L.; Sanzari, Jenine K.; Wilson, Jolaine M.; Rightnar, Steve; Wroe, Andrew J.; Koss, Peter; Gridley, Daila S.; Slater, James M.; Kennedy, Ann R.

2013-01-01

164

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

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

2012-01-01

165

Experimental Human Exposure to Propylene Glycol Dinitrate.  

National Technical Information Service (NTIS)

Human volunteers were exposed to PGDN vapor at concentrations of 0.03, 0.1, 0.2, 0.35, 0.5, and 1.5 ppm. Exposure to concentrations of 0.2 and greater produced disruption of the organization of the visual evoked response (VER) and headache in the majority...

R. D. Stewart J. E. Peterson C. L. Hake M. J. Hosko P. E. Newton

1973-01-01

166

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...

167

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...

168

DEVELOPING MEANINGFUL COHORTS FOR HUMAN EXPOSURE MODELS  

EPA Science Inventory

This paper summarizes numerous statistical analyses focused on the U.S. Environmental Protection Agency's Consolidated Human Activity Database (CHAD), used by many exposure modelers as the basis for data on what people do and where they spend their time. In doing so, modelers ...

169

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...

170

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.

Engelsen, Ola

2010-01-01

171

Fear of the unknown: ionizing radiation exposure during pregnancy.  

PubMed

Ionizing radiation during pregnancy can negatively impact a fetus. In light of the Fukushima nuclear plant disaster in Japan, we discuss existing knowledge on the health effects of radiation and preventive measures for pregnant women. Overall, the risk of exposure to radiation is limited but severe defects can result from fetal radiation exposure >100 mGy equivalent to 10 rad (>1000 chest x-rays). While such high-level exposure rarely occurs during single medical diagnostic procedures, caution should be exercised for pregnant women. As a protective public health measure in light of a disaster, evacuation, shielding, and elimination of ingested radioactive isotopes should all be considered. Detailed radiation reports with health effects and precautionary measures should be available for a population exposed to more than background radiation. PMID:22244469

Groen, Reinou S; Bae, Jin Y; Lim, Kyoung J

2012-06-01

172

Regulation of nuclear radiation exposures in India.  

PubMed

India has a long-term program of wide spread applications of nuclear radiations and radioactive sources for peaceful applications in medicine, industry, agriculture and research and is already having several thousand places in the country where such sources are being routinely used. These places are mostly outside the Department of Atomic Energy (DAE) installations. DAE supplies such sources. The most important application of nuclear energy in DAE is in electricity generation through nuclear power plants. Fourteen such plants are operating and many new plants are at various stages of construction. In view of the above mentioned wide spread applications, Indian parliament through an Act, called Atomic Energy Act, 1964 created an autonomous body called Atomic Energy Regulatory Board (AERB) with comprehensive authority and powers. This Board issues codes, guides, manuals, etc., to regulate such installations so as to ensure safe use of such sources and personnel engaged in such installations and environment receives radiation exposures within the upper bounds prescribed by them. Periodic reports are submitted to AERB to demonstrate compliance of its directives. Health, Safety and Environment Group of Bhabha Atomic Research Centres, Mumbai carries out necessary surveillance and monitoring of all installations of the DAE on a routine basis and also periodic inspections of other installations using radiation sources. Some of the nuclear fuel cycle plants like nuclear power plants and fuel reprocessing involve large radioactive source inventories and have potential of accidental release of radioactivity into the environment, an Environmental Surveillance Laboratory (ESL) is set up at each such site much before the facility goes into operation. These ESL's collect baseline data and monitor the environment throughout the life of the facilities including the decommissioning stage. The data is provided to AERB and is available to members of the public. In addition, a multi-tier system of AERB permissions is in place to ensure that all aspects of safety have been considered before permission to operate is granted. The stages where permission of AERB is essential are site selection, design data, and several stages during construction and operation. The details required by AERB include provision for treatment and storage of radioactive waste, de-commissioning procedures and provision of costs. In addition to AERB, nuclear power plants have to comply with the requirements of Ministry of Environment and Forests and get their clearance. This is given on the basis of Environmental Impact Assessment Report which should satisfy the authorities that no ecological damage will be caused and the facility will not have adverse effect on the environment. In addition, the State Pollution Control Board where the facility is to be located has to permit the site of the plant for its proposed discharges into the environment. It is largely due to the above comprehensive regulatory controls that none of the plants in India had any accident during the last 34 decades of operation. The type of measurements carried out by the ESL's and results from a few typical ESL's will be presented. PMID:15162860

Mishra, U C

2004-01-01

173

DUAL ION EXPOSURE VS. SPLIT-DOSE EXPOSURES IN HUMAN CELL NEOPLASTIC TRANSFORMATION.  

SciTech Connect

Since radiation fields of space contain many-fold more protons than high atomic number, high energy (HZE) particles, cells in astronaut crews will experience on average several proton hits before an HZE hit. Thus radiation regimes of proton exposure before HZE particle exposure simulate space radiation exposure, and measurement of the frequency of neoplastic transformation of human primary cells to anchorage-independent growth simulates in initial step in cancer induction. Previously our group found that exposure to 20 cGy 1 GeV/n protons followed within about 1 hr by a HZE ion (20 cGy 1 GeV/n Fe or Ti ions) hit gave about a 3-fold increase in transformation frequency ([1]). To provide insight into the H-HZE induced increased transformation frequencies, we asked if split doses of the same ion gave similar increased transformation frequencies. However, the data show that the split dose of 20 cGy plus 20 cGy of either H or HZE ions gave about the same effect as the 40 cGy uninterrupted dose, quite different from the effect of the mixed ion H + HZE irradiation. We also asked if lower proton doses than 20 cGy followed 15 minutes later by 20 cGy of HZE ions gave greater than additive transformation frequencies. Substantial increases in transformation levels were observed for all proton doses tested, including 1 cGy. These results point to the signal importance of protons in affecting the effect of space radiation on human cells.

BENNETT, P.V.; CUTTER, N.C.; SUTHERLAND, B.M.

2006-06-05

174

Radon in context of natural radiation exposure: the Czech experience.  

PubMed

Radon issue should be seen in the context of other human exposures and harms. The range of doses from the internal (inhalation and ingestion) and external exposure pathways is presented. Indoor radon regulation is compared with regulation of other natural exposures. PMID:18420564

Hulka, J

2008-01-01

175

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

176

Parental exposure to medical radiation and neuroblastoma in offspring.  

PubMed

Previous studies have suggested an association between parental medical radiation exposure and increased incidence of certain childhood cancers. We investigated the relationship between medical radiation and risk of neuroblastoma in offspring using data from a North American case-control study. Cases were children diagnosed with neuroblastoma from 1 May 1992, to 30 April 1994, at Children's Cancer Group and Pediatric Oncology Group institutions throughout the United States and Canada. One matched control per case was selected using random-digit dialling. Telephone interviews were conducted with parents to collect data on any medical radiation examinations and treatments in the 2 years before conception or during pregnancy. We included 500 maternal and 339 paternal matched pairs. Overall, no association was found between maternal exposure to radiation and neuroblastoma risk (odds ratio [OR] = 1.0; 95% confidence interval [CI]: 0.7, 1.3). Analysis of maternal exposure by specific anatomical site showed no association for gonadal sites [OR = 1.0; 95% CI = 0.5, 2.0]. Little association was found with paternal radiation exposure [OR = 1.2; 95% CI = 0.8, 1.8]. No consistent exposure-response gradient was found based upon the number of maternal or paternal medical radiation examinations. The data presented here, coupled with the lower radiation doses currently used, indicate that any further study of this question will require larger studies with improved exposure assessment. PMID:15130156

Patton, Tara; Olshan, Andrew F; Neglia, Joseph P; Castleberry, Robert P; Smith, Joanna

2004-05-01

177

[Solar radiation exposure in agriculture: an underestimated risk].  

PubMed

Solar Radiation (SR) is a major occupational risk in agriculture, mainly related to its ultraviolet (UV) component. Available data show that UV occupational limits are frequently exceeded in these workers, resulting in an increased occupational risk of various acute and chronic effects, mainly to skin and to the eye. One of the foremost is the carcinogenic effect: SR is indeed included in Group 1 IARC (carcinogenic to humans). UV exposure is related to an increase of the incidence of basal cell carcinoma and squamous cell carcinoma of the skin, and cutaneous malignant melanoma (CMM). The incidence of these tumors, especially CMM, is constantly increasing in Caucasians in the last 50 years. As a conclusion, an adequate evaluation of the occupational risk related to SR, and adequate preventive measures are essential in agriculture. The role of the Occupational Physician in prevention is fundamental. PMID:23405670

Gobba, F

2012-01-01

178

Human mutagens: evidence from paternal exposure  

SciTech Connect

The importance of inherited mutations as a cause of human disease has been established clearly through examples of well-defined genetic anomalies, such as Down syndrome and retinoblastoma. Furthermore, it is suspected that environmental contaminants induce mutations resulting in increased risk for such defects in subsequent generations of persons exposed. The present lack of direct evidence for induced inherited genetic disorders in human beings hampers the development of risk estimation techniques for extrapolation from animal models. The most extensive prospective epidemiologic studies of inherited genetic effects have involved survivors of atomic bomb detonations and patients treated with cancer chemotherapy. In neither case has a significant elevation in inherited genetic effects or cancer been detected in the offspring of exposed individuals. Epidemiologic studies of subjects receiving chronic exposure may be confounded by the effect of maternal exposure during pregnancy. Consideration of only paternal exposure can minimize the confounding influence of teratogenicity, enhancing the resolving power of studies for inherited effects. Using this approach, retrospective (case-control) studies of childhood cancer patients have provided limited but suggestive evidence for inheritance of induced effects. Endpoints, such as congenital malformations and spontaneous abortion following paternal exposure, can also be considered as indicators of heritable mutagenic effects. For example, there is limited evidence suggesting that paternal exposure to anaesthetic gases may cause miscarriage and congenital abnormalities as a result of induced male germ cell mutations. 104 references.

Narod, S.A.; Douglas, G.R.; Nestmann, E.R.; Blakey, D.H.

1988-01-01

179

Preconception exposure to mutagens: medical and other exposures to radiation and chemicals.  

PubMed

Contrary to intuition, no environmental exposure has been proved to cause human germ line mutations that manifest as heritable disease in the offspring, not among the children born to survivors of the American atomic bombs in Japan nor in survivors of cancer in childhood, adolescence, or young adulthood who receive intensive chemotherapy, radiotherapy, or both. Even the smallest of recent case series had sufficient statistical power to exclude, with the usual assumptions, an increase as small as 20 % over baseline rates. One positive epidemiologic study of a localized epidemic of Down syndrome in Hungary found an association with periconceptual exposure to a pesticide used in fish farming, trichlorfon. Current population and occupational guidelines to protect against genetic effects of ionizing radiation should continue, with the understanding they are based on extrapolations from mouse experiments and mostly on males. Presently, pre-conceptual counseling for possible germ cell mutation due to the environment can be very reassuring, at least based on, in a sense, the worst-case exposures of cancer survivors. Prudence demands further study. Future work will address the issue with total genomic sequencing and epigenomic analysis. PMID:22752838

Mulvihill, John J

2012-07-01

180

Nuclear Fragmentation Processes Relevant for Human Space Radiation Protection  

NASA Astrophysics Data System (ADS)

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

2007-04-01

181

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 Commisson on Radiological Protection (ICRP) were estimated from the registered absorbed doses.

Gustafsson, M.; Lunderquist, A.

1981-09-01

182

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

183

Are the conformational dynamics and the ligand binding properties of myoglobin affected by exposure to microwave radiation?  

Microsoft Academic Search

The global uptake of mobile communication emphasizes the question about possible adverse consequences of the exposure to low-level radiofrequency radiation from mobile phones on human health as result of so-called \\

Ettore Bismuto; Fabrizio Mancinelli; Guglielmo d'Ambrosio; Rita Massa

2003-01-01

184

Exposure of Human Cells to Electromagnetic Fields.  

National Technical Information Service (NTIS)

This study addressed the following basic question: How does extremely low-level non-ionizing radiation affect human cells, and if there are cellular responses that can be directly related to signal parameters such as frequency, amplitude and time of expos...

A. S. Henderson

1990-01-01

185

INVITED EDITORIAL: On estimates of population radiation exposure  

Microsoft Academic Search

Each Member State of the European Union is currently committed to producing national legislation demonstrating conformity with the European Directive on medical exposures [1]. In the run up to the production of the Directive, the Article 31 group of experts considered a formal requirement for each Member State to produce annual returns on the total radiation exposure of its population.

Penny Allisy-Roberts

2001-01-01

186

Radiation exposures in Utah from Nevada Nuclear Tests  

Microsoft Academic Search

The exposure of the population of Utah to external gamma-radiation from the fallout from nuclear weapons tests carried out between 1951 and 1958 at the Nevada Test Site has been reconstructed from recent measurements of residual cesium-137 and plutonium in soil. Although the highest exposures were found in the extreme southwest part of Utah, as expected, the residents of the

H. L. Beck; P. W. Krey

1983-01-01

187

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

188

Reducing human exposure to Mycobacterium avium.  

PubMed

In light of the increasing prevalence of Mycobacterium avium pulmonary disease and the challenges of treating patients with M. avium infection, consideration of measures to reduce exposure is warranted. Because M. avium inhabits water and soil, humans are surrounded by that opportunistic pathogen. Because infection has been linked to the presence of M. avium in household plumbing, increasing hot water temperature, reducing aerosol (mist) exposures in bathrooms and showers, and installing filters that prevent the passage of mycobacteria will likely reduce M. avium exposure. Granular activated carbon (charcoal) filters support the growth of M. avium and should be avoided. When gardening, avoid the inhalation of soil dusts by using a mask or wetting the soil because peat-rich potting soils have high numbers of mycobacteria. PMID:23952861

Falkinham, Joseph O

2013-08-01

189

Radiation Hazards and Countermeasures for Human Space Flight  

NASA Technical Reports Server (NTRS)

Protection of the astronauts from space radiation is NASA's moral and legal responsibility. There can be no manned deep space missions without adequate protection from the ionizing radiation in space. There are tow parts to radiation protection, determining the effects of space radiation on humans so that adequate exposure limits can be set and providing radiation protection that insures those limits will not be exceeded. This talk will review the status of work on these two parts and identify areas that are currently being investigated and gaps in the research that have been identified.

Adams, James H., Jr.

2004-01-01

190

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.

Bostrom, C E; Almen, J; Steen, B; Westerholm, R

1994-01-01

191

Is neutron radiation exposure always detrimental to metals (steels)?  

Microsoft Academic Search

It is well established that irradiated metals and alloys exhibit increased mechanical strength accompanied by reduced ductility, commonly referred to as irradiation strengthening and embrittlement. We talk about radiation damage and environmental degradation of metals following radiation exposure. Indeed, there have been numerous conferences and symposia held and planned on this subject, which include research work and discussions with the

K. Linga Murty

1984-01-01

192

National Report on Human Exposure to Environmental Chemicals  

MedlinePLUS

... this page: About CDC.gov . National Report on Human Exposure to Environmental Chemicals Fourth Report Home Updated ... 9,479 KB] The Fourth National Report on Human Exposure to Environmental Chemicals, Updated Tables, September 2013 ...

193

Radiation exposure from Chest CT: Issues and Strategies  

PubMed Central

Concerns have been raised over alleged overuse of CT scanning and inappropriate selection of scanning methods, all of which expose patients to unnecessary radiation. Thus, it is important to identify clinical situations in which techniques with lower radiation dose such as plain radiography or no radiation such as MRI and occasionally ultrasonography can be chosen over CT scanning. This article proposes the arguments for radiation dose reduction in CT scanning of the chest and discusses recommended practices and studies that address means of reducing radiation exposure associated with CT scanning of the chest.

Maher, Michael M.; Rizzo, Stefania; Kanarek, David; Shephard, Jo-Anne O.

2004-01-01

194

Exposure of the US population from occupational radiation  

SciTech Connect

The National Council on Radiation Protection and Measurements (NCRP) has reviewed the literature on the subject of occupational exposure to ionizing radiation to assemble, in a single document, the effective dose equivalents and the collective effective dose equivalents for the work force. Although achieving this goal involved the difficulties, the current Report provides evidence that occupational exposures are responsible for only a small fraction of the total collective effective dose equivalent for the entire US population. The current Report is intended primarily for the information of the radiation protection community, but it should also be of interest to the layperson for the perspective it provides on the contribution of occupational exposures to the total population exposure.

Not Available

1989-06-01

195

Some recent issues in low-exposure radiation epidemiology.  

PubMed Central

Three areas of activity in the field of low-level radiation epidemiology have been reviewed. They concern the questions of cancer risk related to antenatal X-ray exposure, occupational radiation exposure, and residence in areas of real or supposed increased levels of radiation. Despite the a priori unlikelihood of useful information developing from studies in any of these areas, such investigations are being pursued, and the results are proving to be stimulating. Much important information will be forthcoming in the near future.

MacMahon, B

1989-01-01

196

Radiation Exposure - Multiple Languages: MedlinePlus  

MedlinePLUS

... Multiple Languages Chinese - Traditional (????) French (français) German (Deutsch) Korean (???) Russian (???????) Spanish (español) Tagalog (Tagalog) ... PDF Centers for Disease Control and Prevention German (Deutsch) Acute Radiation Syndrome English Akutes Strahlensyndrom - Deutsch (German) ...

197

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

SciTech Connect

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 [Federal Office of Meteorology and Climatology, MeteoSwiss, Payerne (Switzerland); Milon, Antoine; Vernez, David [Institute of Work and Health, University of Lausanne and Geneva, Lausanne (Switzerland); Bulliard, Jean-Luc [Cancer Epidemiology Unit, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne (Switzerland); Moccozet, Laurent [Institute of Services Science, University of Geneva (Switzerland)

2013-05-10

198

ANTIOXIDANTS REDUCE CONSEQUENCES OF RADIATION EXPOSURE  

PubMed Central

Antioxidants have been studied for their capacity to reduce the cytotoxic effects of radiation in normal tissues for at least 50 years. Early research identified sulfur-containing antioxidants as those with the most beneficial therapeutic ratio, even though these compounds have substantial toxicity when given in-vivo. Other antioxidant molecules (small molecules and enzymatic) have been studied for their capacity to prevent radiation toxicity both with regard to reduction of radiation-related cytotoxicity and for reduction of indirect radiation effects including long-term oxidative damage. Finally, categories of radiation protectors that are not primarily antioxidants, including those that act through acceleration of cell proliferation (e.g. growth factors), prevention of apoptosis, other cellular signaling effects (e.g. cytokine signal modifiers), or augmentation of DNA repair, all have direct or indirect effects on cellular redox state and levels of endogenous antioxidants. In this review we discuss what is known about the radioprotective properties of antioxidants, and what those properties tell us about the DNA and other cellular targets of radiation.

Okunieff, Paul; Swarts, Steven; Keng, Peter; Sun, Weimin; Wang, Wei; Kim, Jung; Yang, Shanmin; Zhang, Hengshan; Liu, Chaomei; Williams, Jacqueline P.; Huser, Amy K.

2009-01-01

199

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

200

Long duration human exposure to microgravity  

NASA Technical Reports Server (NTRS)

Looking toward the era of long duration manned spaceflight, questions remain regarding human adaptation to the weightless environment. In particular, bone calcium loss, cardiovascular deconditioning, and effects of radiation require further study. NASA has undertaken a series of experiments to increase the knowledge base of human adaptation to spaceflight. To date, results in the area of cardiovascular deconditioning countermeasures are the furthest advanced. The results from the upcoming SLS-1 mission will enhance knowledge in all areas. With continued research, there is every confidence that astronauts will be able to be kept healthy for long periods of time.

Huntoon, C. L.

1991-01-01

201

Visual Risk Assessment of Space Radiation Exposure for Future Space Exploration Missions  

NASA Technical Reports Server (NTRS)

Protecting astronauts from space radiation exposure during an interplanetary mission is an important challenge for mission design and operations. If sufficient protection is not provided near solar maximum, the risk can be significant due to exposure to sporadic solar particle events (SPEs) as well as to the continuous galactic cosmic radiation (GCR). Polyethylene shielded "storm shelters" inside spacecraft have been shown to limit total exposure from a large SPE to a permissible level, preventing acute risks and providing a potential approach to fulfill the ALARA (as low as reasonably achievable) requirement. For accurate predictions of radiation dose to astronauts involved in future space exploration missions, detailed variations of radiation shielding properties are required. Radiation fluences and doses vary considerably across both the spacecraft geometry and the body-shielding distribution. A model using a modern CAD tool ProE(TradeMark), which is the leading engineering design platform at NASA, has been developed to account for these local variations in the radiation distribution. Visual assessment of radiation distribution at different points inside a spacecraft module and in the human body for a given radiation environment are described. Results will ultimately guide in developing requirements for maximal protection for astronauts from space radiation.

Hussein, Hesham F.; Kim, Myung-Hee; Cucinotta, Francis A.

2006-01-01

202

Biomarkers of human exposure to pesticides.  

PubMed

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

1997-06-01

203

Retinal damage from long-term exposure to laser radiation.  

PubMed

The maculae of rhesus monkeys were exposed to an argon-ion lazer operated in the TEM00 continuous wave mode at a wavelength of 514.5 nm. Both ophthalmoscopic and histopathologic evaluations of exposure sites were obtained. Threshold (ED50) values were obtained for 0.5, 5, 30, 120, and 1,000 sec. exposure times. Presence of minimum visible lesions was assessed ophthalmoscopically at both 1 hour and 24 hours after exposure. With increasing exposure times, a 24 hr. lesion-appearance criterion resulted in ED50 values too low to be consistent with a thermal damage mechanism. In contrast, exposure to neodymium laser radiation at a 1,060 nm. wavelength for 120 sec. produced only ED50 values consistent with those associated with thermal injury. These results suggest that the damage mechanisms for long-duration exposures to visible light may involve photochemical processes initiated by the interaction of visible light with the retinal photopigments. PMID:405344

Gibbons, W D; Allen, R G

1977-06-01

204

Human sperm aneuploidy after exposure to pesticides.  

PubMed

This study examined the effect of paternal environmental exposure to pesticides on the frequency of aneuploidy in human sperm. To determine if the chromosome number in germ cells was altered by paternal exposure, multicolor fluorescence in situ hybridization (FISH) analysis was utilized to measure aneuploidy frequencies in the sperm of 40 men (20 exposed, 20 controls). Samples were coded for "blind analysis" to eliminate scorer bias. Aneuploidy and diploidy frequencies were assessed for chromosomes 13, 21, X, and Y. A minimum of 10,000 sperm was scored per donor per chromosome probe with a total of 809,935 sperm scored. Hybridization efficiency was 99%. There were no significant differences in aneuploidy or diploidy frequencies between exposed and control groups, suggesting that the pesticides did not increase the risk of numerical chromosomal abnormalities in these men. PMID:14735496

Smith, Jena L; Garry, Vincent F; Rademaker, Alfred W; Martin, Renée H

2004-03-01

205

Savannah River Plant/Savannah River Laboratory radiation exposure report  

SciTech Connect

The protection of worker health and safety is of paramount concern at the Savannah River Site. Since the site is one of the largest nuclear sites in the nation, radiation safety is a key element in the protection program. This report is a compendium of the results in 1988 of the programs at the Savannah River Plant and the Savannah River Laboratory to protect the radiological health of employees. By any measure, the radiation protection performance at this site in 1988 was the best since the beginning of operations. This accomplishment was made possible by the commitment and support at all levels of the organizations to reduce radiation exposures to ALARA (As Low As Reasonably Achievable). The report provides detailed information about the radiation doses received by departments and work groups within these organizations. It also includes exposure data for recent years to allow Plant and Laboratory units to track the effectiveness of their ALARA efforts. Many of the successful practices and methods that reduced radiation exposure are described. A new goal for personnel contamination cases has been established for 1989. Only through continual and innovative efforts to minimize exposures can the goals be met. The radiation protection goals for 1989 and previous years are included in the report. 27 figs., 58 tabs.

Rogers, C.D.; Hyman, S.D.; Keisler, L.L. (Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Plant); Reeder, D.F.; Jolly, L.; Spoerner, M.T.; Schramm, G.R. (Du Pont de Nemours (E.I.) and Co., Aiken, SC (USA). Savannah River Lab.)

1989-01-01

206

Health Impacts from Acute Radiation Exposure  

SciTech Connect

Absorbed doses above1-2 Gy (100-200 rads) received over a period of a day or less lead to one or another of the acute radiation syndromes. These are the hematopoietic syndrome, the gastrointestinal (GI) syndrome, the cerebrovascular (CV) syndrome, the pulmonary syndrome, or the cutaneous syndrome. The dose that will kill about 50% of the exposed people within 60 days with minimal medical care, LD50-60, is around 4.5 Gy (450 rads) of low-LET radiation measured free in air. The GI syndrome may not be fatal with supportive medical care and growth factors below about 10 Gy (1000 rads), but above this is likely to be fatal. Pulmonary and cutaneous syndromes may or may not be fatal, depending on many factors. The CV syndrome is invariably fatal. Lower acute doses, or protracted doses delivered over days or weeks, may lead to many other health outcomes than death. These include loss of pregnancy, cataract, impaired fertility or temporary or permanent sterility, hair loss, skin ulceration, local tissue necrosis, developmental abnormalities including mental and growth retardation in persons irradiated as children or fetuses, radiation dermatitis, and other symptoms listed in Table 2 on page 12. Children of parents irradiated prior to conception may experience heritable ill-health, that is, genetic changes from their parents. These effects are less strongly expressed than previously thought. Populations irradiated to high doses at high dose rates have increased risk of cancer incidence and mortality, taken as about 10-20% incidence and perhaps 5-10% mortality per sievert of effective dose of any radiation or per gray of whole-body absorbed dose low-LET radiation. Cancer risks for non-uniform irradiation will be less.

Strom, Daniel J.

2003-09-30

207

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

Code of Federal Regulations, 2013 CFR

... false 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)...

2013-07-01

208

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

209

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.

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

2013-01-01

210

Consideration of measurements and calculations involved in assessment of the effects of human exposure to low doses of ionizing radiation and other mutagens  

NASA Astrophysics Data System (ADS)

Theoretical considerations previously presented are reviewed demonstrating that current methodologies designed to measure environmental mutagenesis contributing to human disease measure only a small fraction of such insults. In the absence of an adequate theoretical approach, a new experimental method has been developed which in the case of X-irradiation demonstrates approximately 100-fold more mutations than are detected by other approaches. There is reason to expect major contributions to preventive medicine from these developments.

Puck, Theodore T.

1985-06-01

211

An analysis of the distribution and dose response of chromosome aberrations in human lymphocytes after in vitro exposure to 137 Cesium gamma radiation  

Microsoft Academic Search

Summary The chromosome aberration yield for human lymphocytes exposed in vitro to various doses of137Cesium has been studied. Dicentric, total acentric, and excess acentric data were seen to follow a Possion distribution. Calculated total hits demonstrated over-dispersion which could possibly be accounted for by a greater occurrence of single-hit phenomena being repaired than two-hit exchange processes. The resulting distribution generally

Norman A. Doggett; Wendell H. McKenzie

1983-01-01

212

The role of cyclin D1 in response to long-term exposure to ionizing radiation.  

PubMed

The health-related hazards resulting from long-term exposure to radiation remain unknown. Thus, an appropriate molecular marker is needed to clarify these effects. Cyclin D1 regulates the cell cycle transition from the G 1 phase to the S phase. Cyclin D1 is degraded as a G1/S checkpoint after 10 Gy of single acute radiation exposure, whereas conversely, cyclin D1 is stabilized when human tumor cells are exposed to fractionated radiation (FR) with 0.5 Gy of x-rays for 31 d. In this article, we review new findings regarding cyclin D1 overexpression in response to long-term exposure to FR. Cyclin D1 overexpression is associated with induction of genomic instability in irradiated cells. Therefore, repression of cyclin D1 expression is likely to cancel the harmful effects of long-term exposure to FR. Thus cyclin D1 may be a marker of long-term exposure to radiation and is a putative molecular radioprotection target for radiation safety. PMID:23974042

Shimura, Tsutomu; Fukumoto, Manabu; Kunugita, Naoki

2013-09-01

213

Adipose Tissue Sensitivity to Radiation Exposure  

PubMed Central

Treatment of cancer using radiation can be significantly compromised by the development of severe acute and late damage to normal tissue. Treatments that either reduce the risk and severity of damage or that facilitate the healing of radiation injuries are being developed, including autologous adipose tissue grafts to repair tissue defects or involutional disorders that result from tumor resection. Adipose tissue is specialized in energy storage and contains different cell types, including preadipocytes, which could be used for autologous transplantation. It has long been considered a poorly proliferative connective tissue; however, the acute effects of ionizing radiation on adipose tissue have not been investigated. Therefore, the aim of this study was to characterize the alterations induced in adipose tissue by total body irradiation. A severe decrease in proliferating cells, as well as a significant increase in apoptotic cells, was observed in vivo in inguinal fat pads following irradiation. Additionally, irradiation altered the hematopoietic population. Decreases in the proliferation and differentiation capacities of non-hematopoietic progenitors were also observed following irradiation. Together, these data demonstrate that subcutaneous adipose tissue is very sensitive to irradiation, leading to a profound alteration of its developmental potential. This damage could also alter the reconstructive properties of adipose tissue and, therefore, calls into question its use in autologous fat transfer following radiotherapy.

Poglio, Sandrine; Galvani, Sylvain; Bour, Sandy; Andre, Mireille; Prunet-Marcassus, Benedicte; Penicaud, Luc; Casteilla, Louis; Cousin, Beatrice

2009-01-01

214

Human EEG and microwave radiation from cell phones  

Microsoft Academic Search

The effects of exposure to microwave radiation from cellular mobile telephones on human brain wave potentials or electroencephalograms have been studied. In particular, a large number of small, metallic electrodes typically are placed upon a subject's scalp, with electrically conducting paste or a glue-like substance to hold them in place. Low voltage signals (< 500 ?V) are amplified by the

James C. Lin

2004-01-01

215

Radiation-Induced Bystander Effects in Cultured Human Stem Cells  

Microsoft Academic Search

BackgroundThe radiation-induced “bystander effect” (RIBE) was shown to occur in a number of experimental systems both in vitro and in vivo as a result of exposure to ionizing radiation (IR). RIBE manifests itself by intercellular communication from irradiated cells to non-irradiated cells which may cause DNA damage and eventual death in these bystander cells. It is known that human stem

Mykyta V. Sokolov; Ronald D. Neumann; Henning Ulrich

2010-01-01

216

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

217

Simulation of the received daily visible and UV radiation exposure as a function of weather, environment and activity  

Microsoft Academic Search

The determination of the exposure of UV- and light received by people as a function of their activities and their environment, for present and future conditions, is the aim of the presented study. In this paper we present first preliminary results and simula-tions. A software was developed to determine the total daily radiation exposure re-ceived by the human body as

K. Huber; P. Weihs; W. Laube; G. Schauberger; A. Schmalwieser; F. Holawe

2003-01-01

218

Risk Assessment of Radiation Exposure using Molecular Biodosimetry  

NASA Technical Reports Server (NTRS)

Current cytogenetic biodosimetry methods would be difficult to adapt to spaceflight operations, because they require toxic chemicals and a substantial amount of time to perform. In addition, current biodosimetry techniques are limited to whole body doses over about 10cGy. Development of new techniques that assess radiation exposure response at the molecular level could overcome these limitations and have important implications in the advancement of biodosimetry. Recent technical advances include expression profiling at the transcript and protein level to assess multiple biomarkers of exposure, which may lead to the development of a radiation biomarker panel revealing possible fingerprints of individual radiation sensitivity. So far, many biomarkers of interest have been examined in their response to ionizing radiation, such as cytokines and members of the DNA repair pathway. New technology, such as the Luminex system can analyze many biomarkers simultaneously in one sample.

Elliott, Todd F.; George, K.; Hammond, D. K.; Cucinotta, F. A.

2007-01-01

219

AN APPROACH TO METHODS DEVELOPMENT FOR HUMAN EXPOSURE ASSESSMENT STUDIES  

EPA Science Inventory

Human exposure assessment studies require methods that are rapid, cost-effective and have a high sample through-put. The development of analytical methods for exposure studies should be based on specific information for individual studies. Human exposure studies suggest that di...

220

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...

221

Estimating natural UV personal exposure with radiative transfer calculations.  

PubMed

The following study has investigated whether straightforward radiative transfer calculations can be used to adequately document natural UV personal exposure. The method was evaluated by comparing the results with erythemal doses accumulated by polysulphone films positioned on mannequins. The calculations succeeded in reproducing the variability associated with changing solar zenith angle and atmospheric conditions. A possible use of the model has been illustrated by estimating the daily exposure during 1 y of a hypothetical office worker, according to a simple occupational schedule. The calculated daily exposures indicated the importance of holiday periods in the risk of acute overexposure and in the total yearly dose. PMID:20670965

Verdebout, J

2010-10-01

222

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

223

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

224

Final Report on Effects of Environmental Radiation of Kori Nuclear Power Plant on Human Population. Base Line Survey.  

National Technical Information Service (NTIS)

In order to clarify and protect the effects of environmental radiation according to the operation of Kori nuclear power plant on the human population, the base line survey for the human monitoring, human life habits, expected individual exposure dose, fre...

Y. J. Kim J. B. Kim K. H. Chung K. S. Lee S. R. Kim

1980-01-01

225

Environmental radiation exposure: Regulation, monitoring, and assessment  

SciTech Connect

Radioactive releases to the environment from nuclear facilities constitute a public health concern. Protecting the public from such releases can be achieved through the establishment and enforcement of regulatory standards. In the United States, numerous standards have been promulgated to regulate release control at nuclear facilities. Most recent standards are more restrictive than those in the past and require that radioactivity levels be as low as reasonably achievable (ALARA). Environmental monitoring programs and radiological dose assessment are means of ensuring compliance with regulations. Environmental monitoring programs provide empirical information on releases, such as the concentrations of released radioactivity in environmental media, while radiological dose assessment provides the analytical means of quantifying dose exposures for demonstrating compliance.

Chen, S.Y.; Yu, C.; Hong, K.J.

1991-01-01

226

Radiation exposure of LDEF: Initial results  

NASA Technical Reports Server (NTRS)

Initial results from LDEF include radiation detector measurements from four experiments, P0006, P0004, M0004, and A0015. The detectors were located on both the leading and trailing edges of the orbiter and also on the Earthside end. This allowed the directional dependence of the incoming radiation to be measured. Total absorbed doses from thermoluminescent detectors (TLDs) verified the predicted spatial east-west dose ratio dependence of a factor approx. 2.5, due to trapped proton anisotropy in the South Atlantic Anomaly. On the trailing edge of the orbiter a range of doses from 6.64 to 2.91 Gy were measured under Al equivalent shielding of 0.42 to 1.11 g/sq cm. A second set of detectors near this location yielded doses of 6.48 to 2.66 Gy under Al equivalent shielding of 0.48 to 15.4 g/sq cm. On the leading edge, doses of 2.58 to 2.10 Gy were found under Al equivalent shielding of 1.37 to 2.90 g/sq cm. Initial charged particle LET (linear energy transfer) spectra, fluxes, doses and dose equivalents, for LET in H2O greater than or = 8 keV/micron, were measured with plastic nuclear track detectors (PNTDs) located in two experiments. Also preliminary data on low energy neutrons were obtained from detectors containing (6)LiF foils.

Benton, E. V.; Frank, A. L.; Benton, E. R.; Csige, I.; Parnell, T. A.; Watts, J. W., Jr.

1992-01-01

227

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

228

Ionizing radiation exposure of LDEF (pre-recovery estimates).  

PubMed

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. PMID:11537534

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

1992-01-01

229

Prospective Measurement of Patient Exposure to Radiation During Pediatric Ureteroscopy  

PubMed Central

Objective Little data have been reported regarding radiation exposure during pediatric endourologic procedures, including ureteroscopy (URS). We sought to measure radiation exposure during pediatric URS and identify opportunities for exposure reduction. Methods We prospectively observed URS procedures as part of a quality improvement initiative. Pre-operative patient characteristics, operative factors, fluoroscopy settings and radiation exposure were recorded. Our outcomes were entrance skin dose (ESD, in mGy) and midline dose (MLD, in mGy). Specific modifiable factors were identified as targets for potential quality improvement. Results Direct observation was performed on 56 consecutive URS procedures. Mean patient age was 14.8 ± 3.8 years (range 7.4 to 19.2); 9 children were under age 12 years. Mean ESD was 46.4 ± 48 mGy. Mean MLD was 6.2 ± 5.0 mGy. The most important major determinant of radiation dose was total fluoroscopy time (mean 2.68 ± 1.8 min) followed by dose rate setting, child anterior-posterior (AP) diameter, and source to skin distance (all p<0.01). The analysis of factors affecting exposure levels found that the use of ureteral access sheaths (p=0.01) and retrograde pyelography (p=0.04) were significantly associated with fluoroscopy time. We also found that dose rate settings were higher than recommended in up to 43% of cases and ideal C-arm positioning could have reduced exposure 14% (up to 49% in some cases). Conclusions Children receive biologically significant radiation doses during URS procedures. Several modifiable factors contribute to dose and could be targeted in efforts to implement dose reduction strategies.

Kokorowski, Paul J.; Chow, Jeanne S.; Strauss, Keith; Pennison, Melanie; Routh, Jonathan C.; Nelson, Caleb P.

2013-01-01

230

Relationship between DNA double-strand break rejoining and cell survival after exposure to ionizing radiation in human fibroblast strains with differing ATM/p53 status: Implications for evaluation of clinical radiosensitivity  

SciTech Connect

Purpose: To better understand the impact of defects in the DNA damage-surveillance network on the various cell-based assays used for the prediction of patient radiosensitivity. Methods and Materials: We examined noncancerous human fibroblast strains from individuals with ataxia telangiectasia (ataxia telangiectasia mutated [ATM] deficient) or Li-Fraumeni syndrome (p53 deficient) using the neutral comet, H2AX phosphorylation, and clonogenic survival assays. Results: Using the comet assay, we found that, compared with normal fibroblasts, cells lacking either ATM or p53 function exhibited a reduced rate of double-strand break (DSB) rejoining early ({<=}4 h) after exposure to 8 Gy of {gamma}-radiation and also exhibited high levels of unrejoined DSBs later after irradiation. ATM-deficient and p53-deficient fibroblasts also exhibited abnormally increased levels of phosphorylated H2AX ({gamma}-H2AX) at later intervals after irradiation. In the clonogenic assay, ATM-deficient cells exhibited marked radiosensitivity and p53-deficient cells had varying degrees of radioresistance compared with normal fibroblasts. Conclusion: Regardless of whether ataxia telangiectasia and Li-Fraumeni syndrome fibroblasts are DSB-repair deficient per se, it is apparent that p53 and ATM defects greatly influence the cellular phenotype as evidenced by the neutral comet and {gamma}-H2AX assays. Our data suggest that the {gamma}-H2AX levels observed at later intervals after irradiation may represent a reliable measure of the overall DSB rejoining capabilities of human fibroblasts. However, it appears that using this parameter as a predictor of radiosensitivity without knowledge of the cells' p53 status could lead to incorrect conclusions.

Mirzayans, Razmik [Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta (Canada); Severin, Diane [Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta (Canada); Murray, David [Department of Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta (Canada)]. E-mail: davem@cancerboard.ab.ca

2006-12-01

231

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

232

Biomarkers of human exposure to benzene  

SciTech Connect

Three biomarkers for benzene exposure were developed. The first biomarker, muconic acid in urine, results from the ring opening of a benzene metabolite. A gas chromatography/mass spectroscopy (GC/MS) assay was developed to measure urinary muconic acid, and the analyte in urine samples from workers occupationally exposed to benzene was determined. Workers exposed to benzene concentrations as low as 4.4 ppm over an 8-h day showed higher urinary muconic acid concentrations than did any control individual (p < .005). The second biomarker, S-phenylcysteine (SPC) in hemoglobin (Hb), results from the addition of benzene oxide to a cysteine sulfhydryl group. A GC/MS assay was developed to measure SPC in the blood of F344/N rats and B67C3F mice exposed to benzene by inhalation. The cysteine moiety on rat Hb is at a more accessible site than on Hb of mice or humans, and rats showed considerably higher levels of SPC than did mice. As yet, we have been unable to detect SPC in the globin of humans occupationally exposed to benzene. The third biomarker is SPC in albumin. In humans occupationally exposed to average concentrations of 0, 4.4, 8.4, and 23.1 ppm benzene, 8 h/d, 5 d/wk, SPC increased in the exposed groups linearly, giving a statistically significant slope (p < .001) of 0.044 [+-] 0.008 pmol/mg albumin/ppm. The assay for SPC is arduous and often imprecise; assuming these difficulties can be overcome, muconic acid in urine and SPC in albumin may be useful for accurately determining benzene exposure. 25 refs., 4 figs., 1 tab.

Bechtold, W.E.; Henderson, R.F. (Inhalation Toxicology Research Institute, Albuquerque, NM (United States))

1993-01-01

233

USE OF EXHALED BREATH CONDENSATE IN A HUMAN EXPOSURE STUDY  

EPA Science Inventory

Exhaled breath condensate (EBC) is a noninvasive, repeatable collection technique to sample biomarkers of lung inflammation, oxidative stress, and environmental exposure. It is unclear whether EBC is an effective tool in human environmental exposure studies with multi-day samplin...

234

INNOVATIVE APPROACHES TO HUMAN EXPOSURE ASSESSMENT IN ENVIRONMENTAL JUSTICE COMMUNITIES  

EPA Science Inventory

North Carolina Central University (NCCU) recently began an innovative human exposure research program in collaboration with the U.S. Environmental Protection Agency's National Exposure Research Laboratory in Research Triangle Park, NC. In this project, researchers will examine ...

235

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 ...

236

59 FR- Federal Radiation Protection Guidance for Exposure of the General Public; Notice ENVIRONMENTAL...  

Federal Register 2010, 2011, 2012, 2013

...important influence in their...meant that attention has been...of public exposure to radiation...understanding of the effects of ionizing...involving exposure to radiation...biological effects of radiation...associated with exposures that may...process and in influencing the public...influence the exposure of the...

1994-12-23

237

Modelling of aircrew radiation exposure during solar particle events  

NASA Astrophysics Data System (ADS)

In 1990, the International Commission on Radiological Protection recognized the occupational exposure of aircrew to cosmic radiation. In Canada, a Commercial and Business Aviation Advisory Circular was issued by Transport Canada suggesting that action should be taken to manage such exposure. In anticipation of possible regulations on exposure of Canadian-based aircrew in the near future, an extensive study was carried out at the Royal Military College of Canada to measure the radiation exposure during commercial flights. The radiation exposure to aircrew is a result of a complex mixed-radiation field resulting from Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs). Supernova explosions and active galactic nuclei are responsible for GCRs which consist of 90% protons, 9% alpha particles, and 1% heavy nuclei. While they have a fairly constant fluence rate, their interaction with the magnetic field of the Earth varies throughout the solar cycles, which has a period of approximately 11 years. SEPs are highly sporadic events that are associated with solar flares and coronal mass ejections. This type of exposure may be of concern to certain aircrew members, such as pregnant flight crew, for which the annual effective dose is limited to 1 mSv over the remainder of the pregnancy. The composition of SEPs is very similar to GCRs, in that they consist of mostly protons, some alpha particles and a few heavy nuclei, but with a softer energy spectrum. An additional factor when analysing SEPs is the effect of flare anisotropy. This refers to the way charged particles are transported through the Earth's magnetosphere in an anisotropic fashion. Solar flares that are fairly isotropic produce a uniform radiation exposure for areas that have similar geomagnetic shielding, while highly anisotropic events produce variable exposures at different locations on the Earth. Studies of neutron monitor count rates from detectors sharing similar geomagnetic shielding properties show a very different response during anisotropic events, leading to variations in aircrew radiation doses that may be significant for dose assessment. To estimate the additional exposure due to solar flares, a model was developed using a Monte-Carlo radiation transport code, MCNPX. The model transports an extrapolated particle spectrum based on satellite measurements through the atmosphere using the MCNPX analysis. This code produces the estimated flux at a specific altitude where radiation dose conversion coefficients are applied to convert the particle flux into effective and ambient dose-equivalent rates. A cut-off rigidity model accounts for the shielding effects of the Earth's magnetic field. Comparisons were made between the model predictions and actual flight measurements taken with various types of instruments used to measure the mixed radiation field during Ground Level Enhancements 60 and 65. An anisotropy analysis that uses neutron monitor responses and the pitch angle distribution of energetic solar particles was used to identify particle anisotropy for a solar event in December 2006. In anticipation of future commercial use, a computer code has been developed to implement the radiation dose assessment model for routine analysis. Keywords: Radiation Dosimetry, Radiation Protection, Space Physics.

Al Anid, Hani Khaled

238

PCS cable connector termination, radiation exposure, and testing  

NASA Astrophysics Data System (ADS)

Tests, concerned with the evaluation of the radiation resistance of fiber optic cables, have shown the superiority of Plastic Clad Silica (PCS) optical fibers at wavelengths in the range from 800 to 900 nanometers, taking into account, in particular, a radiation hard high hydroxyl fiber. The present paper is concerned with a program in which this fiber was studied. One of the objectives of the considered program was the development of a Plastic Clad Silica (PCS) fiber termination technique suitable for use in military tactical systems. Three recladding techniques were selected for evaluation. Attention is given to physical and environmental testing, and the effect of radiation exposure on the connectors.

Ellis, R. H.; Johnson, W. D.

1984-01-01

239

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.

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

2008-01-01

240

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

241

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

242

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.

243

47 CFR 1.1310 - Radiofrequency radiation exposure limits.  

Code of Federal Regulations, 2010 CFR

...Radiation Protection and Measurements (NCRP) in âBiological Effects and Exposure Criteria...Radiofrequency Electromagnetic Fields,â NCRP Report No. 86, Sections 17.4.1...17.4.2 and 17.4.3. Copyright NCRP, 1986, Bethesda, Maryland...

2009-10-01

244

47 CFR 1.1310 - Radiofrequency radiation exposure limits.  

Code of Federal Regulations, 2010 CFR

...Radiation Protection and Measurements (NCRP) in âBiological Effects and Exposure Criteria...Radiofrequency Electromagnetic Fields,â NCRP Report No. 86, Sections 17.4.1...17.4.2 and 17.4.3. Copyright NCRP, 1986, Bethesda, Maryland...

2010-10-01

245

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

246

Reducing waste generation and radiation exposure by analytical method modification  

SciTech Connect

The primary goal of an analytical support laboratory has traditionally been to provide accurate data in a timely and cost effective fashion. Added to this goal is now the need to provide the same high quality data while generating as little waste as possible. At the Savannah River Technology Center (SRTC), we have modified and reengineered several methods to decrease generated waste and hence reduce radiation exposure. These method changes involved improving detection limits (which decreased the amount of sample required for analysis), decreasing reaction and analysis time, decreasing the size of experimental set-ups, recycling spent solvent and reagents, and replacing some methods. These changes had the additional benefits of reducing employee radiation exposure and exposure to hazardous chemicals. In all cases, the precision, accuracy, and detection limits were equal to or better than the replaced method. Most of the changes required little or no expenditure of funds. This paper describes these changes and discusses some of their applications.

Ekechukwu, A.A.

1996-10-01

247

Exposure assessment of mobile phone base station radiation in an outdoor environment using sequential surrogate modeling.  

PubMed

Human exposure to background radiofrequency electromagnetic fields (RF-EMF) has been increasing with the introduction of new technologies. There is a definite need for the quantification of RF-EMF exposure but a robust exposure assessment is not yet possible, mainly due to the lack of a fast and efficient measurement procedure. In this article, a new procedure is proposed for accurately mapping the exposure to base station radiation in an outdoor environment based on surrogate modeling and sequential design, an entirely new approach in the domain of dosimetry for human RF exposure. We tested our procedure in an urban area of about 0.04?km(2) for Global System for Mobile Communications (GSM) technology at 900?MHz (GSM900) using a personal exposimeter. Fifty measurement locations were sufficient to obtain a coarse street exposure map, locating regions of high and low exposure; 70 measurement locations were sufficient to characterize the electric field distribution in the area and build an accurate predictive interpolation model. Hence, accurate GSM900 downlink outdoor exposure maps (for use in, e.g., governmental risk communication and epidemiological studies) are developed by combining the proven efficiency of sequential design with the speed of exposimeter measurements and their ease of handling. PMID:23315952

Aerts, Sam; Deschrijver, Dirk; Joseph, Wout; Verloock, Leen; Goeminne, Francis; Martens, Luc; Dhaene, Tom

2013-05-01

248

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

PubMed

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 208000 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. PMID:7395854

Robinette, C D; Silverman, C; Jablon, S

1980-07-01

249

Radiation exposure at ground level by secondary cosmic radiation  

Microsoft Academic Search

The contribution of the charged component of secondary cosmic radiation to the ambient dose equivalent H?(10) at ground level is investigated using the muon detector MUDOS and a TEPC detector surrounded by the coincidence detector CACS to identify charged particles. The ambient dose equivalent rate H??(10)T as measured with the TEPC\\/CACS is used to calibrate the MUDOS count rate in

F. Wissmann; V. Dangendorf; U. Schrewe

2005-01-01

250

Radiation exposure from diagnostic procedures following allogeneic stem cell transplantation - How much is acceptable?  

PubMed

Background Frequent diagnostic radiology procedures in allogeneic stem cell transplantation (SCT) recipients raise concern about the potential harm from incidental radiation. Objectives To determine the cumulative radiation dose from diagnostic studies in allogeneic SCT and its impact on clinical outcome. Patients and methods This retrospective cohort study was conducted to determine the cumulative radiation dose from diagnostic studies following SCT. Sixty-four consecutive patients with hematological malignancies in a single tertiary care institution underwent total body irradiation (TBI)-based myeloablative conditioning followed by six of six human leukocyte antigen (HLA)-identical sibling allogeneic SCT. The median follow-up was 3 years. The cumulative effective dose in mSv from diagnostic radiological studies in the peri-transplant period from day -30 to day +200 was calculated for each patient and its impact on overall survival and non-relapse mortality was determined. Results The median cumulative radiation exposure from diagnostic radiological procedures was 92 mSv (range 1.2-300), representing about 30× the normal annual background radiation for the population and 10% of the 1200 cGy TBI dose used in conditioning. Sixty-five percent of the cumulative radiation exposure was delivered between day +1 and day 100 and computed tomography scans contributed 88%. In multivariate analysis, diagnostic procedures did not significantly impact clinical outcomes. Conclusions While radiation exposure from diagnostic procedures did not impact clinical outcomes the risk of secondary cancers in long-term survivors is likely to be increased. Our results indicate that patients who are acutely ill for prolonged periods can receive clinically significant radiation doses during their hospital care. Our findings should prompt attempts to limit radiation exposure from diagnostic procedures in post-SCT recipients. PMID:24094072

Battiwalla, Minoo; Fakhrejahani, Farhad; Jain, Natasha A; Klotz, Jeffrey K; Pophali, Priyanka A; Draper, Debbie; Haggerty, Janice; McIver, Zachariah; Jelinek, James; Chawla, Kamna; Ito, Sawa; Barrett, John

2014-07-01

251

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

252

Chromosome aberrations as biomarkers of radiation exposure: Modelling basic mechanisms  

NASA Astrophysics Data System (ADS)

The space radiation environment is a mixed field consisting of different particles having different energies, including high charge and energy (HZE) ions. Conventional measurements of absorbed doses may not be sufficient to completely characterise the radiation field and perform reliable estimates of health risks. Biological dosimetry, based on the observation of specific radiation-induced endpoints (typically chromosome aberrations), can be a helpful approach in case of monitored exposure to space radiation or other mixed fields, as well as in case of accidental exposure. Furthermore, various ratios of aberrations (e.g. dicentric chromosomes to centric rings and complex exchanges to simple exchanges) have been suggested as possible fingerprints of radiation quality, although all of them have been subjected to some criticisms. In this context a mechanistic model and a Monte Carlo code for the simulation of chromosome aberration induction were developed. The model, able to provide dose-responses for different aberrations (e.g. dicentrics, rings, fragments, translocations, insertions and other complex exchanges), was further developed to assess the dependence of various ratios of aberrations on radiation quality. The predictions of the model were compared with available data, whose experimental conditions were faithfully reproduced. Particular attention was devoted to the scoring criteria adopted in different laboratories and to possible biases introduced by interphase death and mitotic delay. This latter aspect was investigated by taking into account both metaphase data and data obtained with Premature Chromosome Condensation (PCC).

Ballarini, F.; Ottolenghi, A.

253

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 grams per square centimeters 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

254

Metaphase chromosome aberrations as markers of radiation exposure and dose  

SciTech Connect

Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes ``paints`` to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with {sup 144}Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to {sup 60}Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness.

Brooks, A.L.; Khan, M.A.; Jostes, R.F.; Cross, F.T.

1992-10-01

255

Metaphase chromosome aberrations as markers of radiation exposure and dose  

SciTech Connect

Chromosome aberration frequency provides the most reliable biological marker of dose for detecting acute accidental radiation exposure. Significant radiation-induced changes in the frequency of chromosome aberrations can be detected at very low doses. Our paper provides information on using molecular chromosome probes paints'' to score chromosome damage and illustrates how technical advances make it possible to understand mechanisms involved during formation of chromosome aberrations. In animal studies chromosome aberrations provide a method to relate cellular damage to cellular dose. Using an In vivo/In vitro approach aberrations provided a biological marker of dose from radon progeny exposure which was used to convert WLM to dose in rat tracheal epithelial cells. Injection of Chinese hamsters with [sup 144]Ce which produced a low dose rate exposure of bone marrow to either low-LET radiation increased the sensitivity of the cells to subsequent external exposure to [sup 60]Co. These studies demonstrated the usefulness of chromosome damage as a biological marker of dose and cellular responsiveness.

Brooks, A.L.; Khan, M.A.; Jostes, R.F.; Cross, F.T.

1992-10-01

256

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.

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

2011-01-01

257

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

258

Radiation-induced genomic instability and bystander effects: inter-related nontargeted effects of exposure to ionizing radiation  

Microsoft Academic Search

The paradigm of genetic alterations being restricted to direct DNA damage after exposure to ionizing radiation has been challenged by observations in which cells that are not exposed to ionizing radiation exhibit responses typically associated with direct radiation exposure. These effects are demonstrated in cells that are the descendants of irradiated cells (radiation-induced genomic instability) or in cells that are

Sally A Lorimore; Philip J Coates; Eric G Wright

2003-01-01

259

Real and perceived risks of medical radiation exposure  

SciTech Connect

After considering all the evidence related to the health effects of exposure to low levels of radiation, it is apparent that the risk is immeasurably small to any single person in a population exposed to small amounts of radiation. However, multiplying this immeasurably small estimate of risk by very large populations yields numbers that seem to imply that significant health effects (cancer, malformations, genetic effects) occur following exposure to small quantities of radiation. Although many advisory groups have cautioned against this procedure and conclusion, both continue to be used by some scientists and political action groups. In a public opinion poll conducted by Decision Research, Inc. of Eugene, Oregon, three groups were asked to rank the relative risks of various societal activities. Two of the three groups ranked nuclear power as the most hazardous of all societal activities, with a risk factor greater than that for smoking, automobiles, handguns and alcohol. Actually, nuclear power is the least hazardous of all 30 of the activities included in the poll. It is a conservative posture and probably a wise course of action to assume that exposure to any amount of radiation carries with it some element of risk. For example, requests for x-ray studies and nuclear medicine procedures should always be accompanied by an appreciation of the possibility of risk to the patient and to radiological personnel. At the same time, this element of risk should be placed in a realistic perspective by comparing it with other risks we assume every day. (JMT)

Hendee, W.R.

1983-03-01

260

Mobile phone radiation might alter protein expression in human skin  

PubMed Central

Background Earlier we have shown that the mobile phone radiation (radiofrequency modulated electromagnetic fields; RF-EMF) alters protein expression in human endothelial cell line. This does not mean that similar response will take place in human body exposed to this radiation. Therefore, in this pilot human volunteer study, using proteomics approach, we have examined whether a local exposure of human skin to RF-EMF will cause changes in protein expression in living people. Results Small area of forearm's skin in 10 female volunteers was exposed to RF-EMF (specific absorption rate SAR = 1.3 W/kg) and punch biopsies were collected from exposed and non-exposed areas of skin. Proteins extracted from biopsies were separated using 2-DE and protein expression changes were analyzed using PDQuest software. Analysis has identified 8 proteins that were statistically significantly affected (Anova and Wilcoxon tests). Two of the proteins were present in all 10 volunteers. This suggests that protein expression in human skin might be affected by the exposure to RF-EMF. The number of affected proteins was similar to the number of affected proteins observed in our earlier in vitro studies. Conclusion This is the first study showing that molecular level changes might take place in human volunteers in response to exposure to RF-EMF. Our study confirms that proteomics screening approach can identify protein targets of RF-EMF in human volunteers.

Karinen, Anu; Heinavaara, Sirpa; Nylund, Reetta; Leszczynski, Dariusz

2008-01-01

261

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

262

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

263

[Cutaneous damage after acute exposure to ionizing radiation: decisive for the prognosis of radiation accident victims].  

PubMed

The cutaneous radiation syndrome includes all deterministic effects on the skin and visible parts of the mucosa from ionizing radiation. The Intensity and duration of radiation-induced skin symptoms depend on the kind and quality of ionizing radiation. The aim of this study was the investigation of the importance of the time of the development of radiation induced-skin effects on the prognosis of radiation accident victims. Clinical data about radiation accident victims from the database SEARCH were used. 211 cases with good documentation regarding radiation-induced skin effects were selected. From these 211 patients, 166 survived the acute phase of the acute radiation syndrome, while 45 died during the acute phase. Among those patients who did not survive the acute phase, 82.2?% showed their first documented radiation-induced skin symptoms during the first 3 days after radiation exposure. Of those patients whose first documented radiation-induced skin symptoms appeared on or after day four, 94.2?% survived the acute phase. The time to the occurrence of the first radiation-induced skin effects is diagnostically significant. The skin plays an important role in the clinical course of radiation syndromes and in the development of radiation-induced multi-organ failure. In a retrospective data analysis like this, the quality of data might be a limitation. PMID:24337305

Dörr, H; Baier, T; Meineke, V

2013-12-01

264

Radiation exposure and protection for moon and Mars missions  

SciTech Connect

A deep space radiation environment of galactic cosmic rays and energetic particles from solar flares imposes stringent requirements for radiation shielding for both personnel and electronic equipment at a moon base or on a Mars expedition. Current Los Alamos capabilities for calculating the effect of such shielding are described, and extensions and validation needed before actual manned deep space missions are launched are outlined. The biological effects of exposure to cosmic-ray ions and to low doses of radiation at low dose rates are poorly understood. Recent Los Alamos work on mutation effects in cells, DNA repair processes, and the analysis of chromosomal aberrations promises to increase our understanding of the basic processes, to provide methods to screen for radiation sensitivity, and to provide advanced dosimetry equipment for space missions.

MacFarlane, R.E.; Prael, R.E.; Strottman, D.D.; Strniste, G.F.; Feldman, W.C.

1991-04-01

265

A reassessment of Galileo radiation exposures in the Jupiter magnetosphere.  

PubMed

Earlier particle experiments in the 1970s on Pioneer-10 and -11 and Voyager-1 and -2 provided Jupiter flyby particle data, which were used by Divine and Garrett to develop the first Jupiter trapped radiation environment model. This model was used to establish a baseline radiation effects design limit for the Galileo onboard electronics. Recently, Garrett et al. have developed an updated Galileo Interim Radiation Environment (GIRE) model based on Galileo electron data. In this paper, we have used the GIRE model to reassess the computed radiation exposures and dose effects for Galileo. The 34-orbit 'as flown' Galileo trajectory data and the updated GIRE model were used to compute the electron and proton spectra for each of the 34 orbits. The total ionisation doses of electrons and protons have been computed based on a parametric shielding configuration, and these results are compared with previously published results. PMID:16604631

Atwell, William; Townsend, Lawrence; Miller, Thomas; Campbell, Christina

2005-01-01

266

Research on reducing radiation exposure for clinical applications of X-ray attenuation  

NASA Astrophysics Data System (ADS)

This study was aimed at identifing areas with low radiation exposure where workers could be taken in the examination room in case that they had to hold the patients by estimating the attenuation of primary radiation and measuring the spatial distribution of scattered radiation. The laboratory equipment included on the X-ray generator, a phantom (human phantom), and a dosimeter. The experiment measured the performance of the examination system (dose reproducibility), the dose of primary radiation (X-rays), and the dose of scattered radiation (secondary radiation). Both the primary and the scattered radiation were attenuated by a factor of tube in vacuum experimental tests of the inverse square law. In this study, the attenuation was 2 ˜ 2.246 for primary radiation and 2 ˜ 2.105 for secondary radiation. Natural attenuation occurred as the X-rays passed through air, and an attenuation equation was established in this study. The equation for primary radiation (1st dose) was y = A1* exp(- x/t1)+ y0. The high-intensity contour of the direction for the cathode was wider than that of the direction for the anode, showing a wide range on the rear side of the cathode and on the rear side of the anode. We tried to find the positions where the workers' radiation exposure could be reduced. When the medical radiation workers have to hold the patient for an abdominal examination, they should be placed towards the tube anode and on the left side of the patient. For a lumbar-spine lateral examination, they should be placed towards the tube anode and behind the patient, and for a femur AP (anterior-posterior) examination, they should be placed towards the tube anode and on the right side of the patient.

Jeon, Min-Cheol; Han, Man-Seok; So, Woon-Young; Lee, Hyeon-Guck; Kim, Yong-Kyun; Lee, Seung-Yeol

2014-02-01

267

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

268

Fitting human exposure data with the Johnson SB distribution  

Microsoft Academic Search

Exposure evaluations for epidemiological investigations and risk assessments may require estimates of background concentrations and peak exposures, as well as the population mean and variance. The SB distribution is a theoretically appealing probability function for characterizing ratios, and random variables bound by extremes, such as human exposures and environmental concentrations. However, fitting the parameters of this distribution with maximum likelihood

Michael R Flynn

2006-01-01

269

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

270

Recommendations on limits for exposure to ionizing radiation. [Contains glossary  

SciTech Connect

This report lists the existing standards or the status of regulations for 19 major topic areas related to exposure to ionizing radiation. Most entries are brief but thorough; some reference recent data. The National Council on Radiation Protection and Measurements (NCRP) published its last complete set of basic recommendations specifying limits for ionizing radiation in 1971. Although this report is not intended to be a complete revision, the recommendations contained herein replace all of the recommendations given in the 1971 Report. In addition, this report contains other basic recommendations. The NCRP believes that a logical direction in the evolution of the basis of radiation protection standards from the present system based on dose equivalent used by the NCRP and the ICRP is toward the development of an approach based specifically on risk. The Council believes that additional review and evaluation are required prior to the introduction of a radiation protection system in which the limitation of exposures is based solely on risk. For the present the Council adopts the effective dose equivalent system used by the ICRP, but has modified and updated this approach in several respects, as discussed in this report.

Not Available

1987-06-01

271

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

272

Mediastinal fibrosis and radiofrequency radiation exposure: is there an association?  

PubMed

A 45-year-old officer, working for a period of 18 years at a military radar base, presented with progressive exertional dyspnea, dry cough, and hemoptysis. Subsequent evaluation demonstrated a left pulmonary artery occlusion as well as a left upper lobe bronchus stenosis, due to a dense fibrotic mediastinal mass. Histologically, this proved to be idiopathic mediastinal fibrosis (IMF). The development of IMF in a man exposed for a long period to radio-frequency radiation (RFR) is unique in the literature in English. The possible association of radiation exposure with IMF is discussed. PMID:1439233

Papandreou, L; Panagou, P; Bouros, D

1992-01-01

273

Radiation exposure and risk assessment for critical female body organs  

SciTech Connect

Space radiation exposure limits for astronauts are based on recommendations of the National Council on Radiation Protection and Measurements. These limits now include the age at exposure and sex of the astronaut. A recently-developed computerized anatomical female (CAF) model is discussed in detail. Computer-generated, cross-sectional data are presented to illustrate the completeness of the CAF model. By applying ray-tracing techniques, shield distribution functions have been computed to calculate absorbed dose and dose equivalent values for a variety of critical body organs (e.g., breasts, lungs, thyroid gland, etc.) and mission scenarios. Specific risk assessments, i.e., cancer induction and mortality, are reviewed. 13 refs.

Atwell, W.; Weyland, M.D.; Hardy, A.C. (Rockwell International Corp., Houston, TX (United States) NASA, Johnson Space Center, Houston, TX (United States))

1991-07-01

274

Positron states in KCL crystals before and after radiation exposure  

NASA Astrophysics Data System (ADS)

The features of positron annihilation in KCl crystals before and after radiation exposure is investigated. A significant increase in the efficiency of the “ortho-vapor” process of positronium state conversion is detected. A model is proposed for taking part in the “ortho-vapor” conversion of conduction electrons drawn into the conduction band by a positron field that affords a qualitative interpretation of the results obtained and permits values of the electron concentration in a spur to be obtained.

Aref'ev, K. P.; Boev, O. V.; Bondarenko, A. L.

1988-07-01

275

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

276

Real-Time Aircraft Cosmic Ray Radiation Exposure Predictions from the NAIRAS Model  

NASA Astrophysics Data System (ADS)

The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. There is also interest in extending NAIRAS to the LEO environment to address radiation hazard issues for the emerging commercial spaceflight industry. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. Real-time observations are required at a variety of locations within the geospace environment. The NAIRAS model is driven by real-time input data from ground-, atmospheric-, and space-based platforms. During the development of the NAIRAS model, new science questions and observational data gaps were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. The focus of this talk is to present the current capabilities of the NAIRAS model, discuss future developments in aviation radiation modeling and instrumentation, and propose strategies and methodologies of bridging known gaps in current modeling and observational capabilities.

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

2012-12-01

277

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

278

Current methods of monitoring radiation exposure from CT.  

PubMed

Increased public and regulatory scrutiny of imaging-related radiation exposure requires familiarity with current dose-monitoring techniques and best practices. CT-related ionizing radiation exposure has been cited as the largest and fastest growing source of population-wide iatrogenic ionizing radiation exposure. Upcoming federal regulations require imaging centers to familiarize themselves with available dose-monitoring techniques and implement comprehensive strategies to track patient dose, with particular emphasis on CT. Because of institution-specific and vendor-specific technologies, there are significant barriers to adoption and implementation. In this article, the authors outline the core components of a universal dose-monitoring strategy and detail a few of the many available commercial platforms. In addition, the authors introduce a cloud-based hybrid model dose-tracking system with the goal of rapid implementation, multicenter scalability, real-time dose feedback for technologists, cumulative dose monitoring, and optional dose communication to patients and into the record; doing so results in improved patient loyalty, referring physician satisfaction, and opportunity for repeat business. PMID:23714720

Talati, Ronak K; Dunkin, Jared; Parikh, Shrujal; Moore, William H

2013-09-01

279

Adjustment of guidelines for exposure of the eye to optical radiation from ocular instruments: statement from a task group of the International Commission on Non-Ionizing Radiation Protection (ICNIRP)  

NASA Astrophysics Data System (ADS)

A variety of optical and electro-optical instruments are used for both diagnostic and therapeutic applications to the human eye. These generally expose ocular structures to either coherent or incoherent optical radiation (ultraviolet, visible, or infrared radiation) under unique conditions. We convert both laser and incoherent exposure guidelines derived for normal exposure conditions to the application of ophthalmic sources.

Sliney, David; Aron-Rosa, Danielle; Delori, Francois; Fankhauser, Franz; Landry, Robert; Mainster, Martin; Marshall, John; Rassow, Bernard; Stuck, Bruce; Trokel, Stephen; Motz West, Teresa; Wolffe, Michael

2005-04-01

280

Radiation exposure case management after incorporation of radionuclides.  

PubMed

The release of radioactive material due to accidents or terroristic actions can result in radioactive contamination of the environment and may lead to intake and incorporation of radionuclides with the consequence of prolonged radiation exposure. In this case, a decision about countermeasures must be carried out as soon as possible to reduce the resulting radiation dose. In order to be prepared for such a scenario, an Assessment and Documentation System has been developed to support the rapid assessment of internal exposures and to assist in decision making. Radionuclide distributions, excretion rates, and resulting exposures have been calculated on the basis of a reference scenario. The documentation of the results in the form of tables and graphs allows the easy and quick interpretation of measurements in terms of exposure and intake. The system in its present status gives information about possibilities of countermeasures; it is the intention of the next steps of development to give advice on the basis of estimated avertable doses. PMID:24776897

Goulko, Guennadi; Dörr, Harald; Meineke, Viktor

2014-06-01

281

67 FR 51422 - Claims Under the Radiation Exposure Compensation Act Amendments of 2000; Technical Amendments  

Federal Register 2010, 2011, 2012, 2013

...amended Act. DATES: Effective date: September...with the Radiation Exposure Compensation Act...developed following exposure to radiation under...substantial direct effects on the States...records to that effect. (b) If the medical...the Radiation Exposure Compensation...

2002-08-07

282

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

283

28 CFR 79.44 - Proof of working level month exposure to radiation.  

Code of Federal Regulations, 2013 CFR

...Proof of working level month exposure to radiation. 79.44 Section 79.44 Judicial...JUSTICE (CONTINUED) CLAIMS UNDER THE RADIATION EXPOSURE COMPENSATION ACT Eligibility...Proof of working level month exposure to radiation. (a) If one or more of the...

2013-07-01

284

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

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Radiation Exposure Compensation Act Offset...CONTINUED) CLAIMS UNDER THE RADIATION EXPOSURE COMPENSATION ACT Pt. 79, App. C Appendix C to Part 79âRadiation Exposure Compensation Act...

2013-07-01

285

Micro RNA responses to chronic or acute exposures to low dose ionizing radiation  

PubMed Central

Human health risks of exposure to low dose ionizing radiation remain ambiguous and are the subject of intense debate. A wide variety of biological effects are induced after cellular exposure to ionizing radiation, but the underlying molecular mechanism(s) remain to be completely understood. We hypothesized that low dose c-radiation-induced effects are controlled by the modulation of micro RNA (miRNA) that participate in the control of gene expression at the posttranscriptional level and are involved in many cellular processes. We monitored the expression of several miRNA in human cells exposed to acute or chronic low doses of 10 cGy or a moderate dose of 400 cGy of 137Cs ?-rays. Dose, dose rate and time dependent differences in the relative expression of several miRNA were investigated. The expression patterns of many miRNA differed after exposure to either chronic or acute 10 cGy. The expression of miRNA let-7e, a negative regulator of RAS oncogene, and the c-MYC miRNA cluster were upregulated after 10 cGy chronic dose but were downregulated after 3 h of acute 10 cGy. The miR-21 was upregulated in chronic or acute low dose and moderate dose treated cells and its target genes hPDCD4, hPTEN, hSPRY2, and hTPM1 were found to be downregulated. These findings provide evidence that low dose and dose rate c-irradiation dictate the modulation of miRNA, which can result in a differential cellular response than occurs at high doses. This information will contribute to understanding the risks to human health after exposure to low dose radiation.

Chaudhry, M. Ahmad; Omaruddin, Romaica A.; Kreger, Bridget; de Toledo, Sonia M.; Azzam, Edouard I.

2014-01-01

286

Reduction of radiation exposure during radiography for scoliosis  

SciTech Connect

To reduce the radiation exposure received by young scoliosis patients during treatment, six changes in technique were instituted: (1) a posteroanterior projection, (2) specially designed leaded acrylic filters, (3) a high-speed screen-film system, (4) a specially designed cassette-holder and grid, (5) a breast-shield, and (6) additional filtration in the x-ray tube the thyroid, breast, and abdominal areas were made on an Alderson phantom. They revealed an eightfold reduction in abdominal exposure for both the posteroanterior and the lateral radiographys. There was a twentyfold reduction in exposure to the thyroid for the posteroanterior radiography from 100 to less than five milliroentgens and for the lateral radiograph there was a 100-fold reduction from 618 to six milliroentgens. For the breasts there was a sixty-ninefold reduction from 344 to less than five milliroentgens for the posteroanterior radiography and a fifty-fivefold reduction from 277 to less than five milliroentgens for the lateral radiograph. These reductions in exposure were obtained without significant loss in the quality of the radiographs and in most instances with an improvement in the over-all quality of the radiograph due to the more uniform exposure.

Gray, J.E.; Hoffman, A.D.; Peterson, H.A.

1983-01-01

287

Method for imaging quantum dots during exposure to gamma radiation  

NASA Astrophysics Data System (ADS)

Quantum dots have been used in a wide variety of biomedical applications. A key advantage of these particles is that their optical properties depend predictably on size, which enables tuning of the emission wavelength. Recently, it was found that CdSe/ZnS quantum dots lose their ability to photoluminescence after exposure to gamma radiation (J. Phys. Chem. C., 113: 2580-2585 (2009). A method for readout of the loss of quantum dot photoluminescence during exposure to radiation could enable a multitude of real-time dosimetry applications. Here, we report on a method to image photoluminescence from quantum dots from a distance and under ambient lighting conditions. The approach was to construct and test a time-gated imaging system that incorporated pulsed illumination. The system was constructed from a pulsed green laser (Nd:YAG, 20 pulses/s, 5 ns pulse duration, ~5 mJ/pulse), a time-gated camera (LaVision Picostar, 2 ns gate width), and optical components to enable coaxial illumination and imaging. Using the system to image samples of equivalent concentration to the previous end-point work, quantum dot photoluminescence was measureable under ambient room lighting at a distance of 25 cm from the sample with a signal to background of 7.5:1. Continuous exposure of samples to pulsed laser produced no measureable loss of photoluminescence over a time period of one hour. With improvements to the light collection optics the range of the system is expected to increase to several metres, which will enable imaging of samples during exposure to a gamma radiation source.

Immucci, Andrea N.; Chamson-Reig, Astrid; Yu, Kui; Wilkinson, Diana; Li, Chunsheng; Stodilka, Robert Z.; Carson, Jeffrey J. L.

2011-03-01

288

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.

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

289

Geomagnetic influence on aircraft radiation exposure during a solar energetic particle event in October 2003  

Microsoft Academic Search

We present initial results from the Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) model during the Halloween 2003 superstorm. The objective of NAIRAS is to produce global, real-time, data-driven predictions of ionizing radiation for archiving and assessing the biologically harmful radiation exposure levels at commercial airline altitudes. We have conducted a case study of radiation exposure during a

Christopher J. Mertens; Brian T. Kress; Michael Wiltberger; Steve R. Blattnig; Tony S. Slaba; Stanley C. Solomon; M. Engel

2010-01-01

290

Cellular adaptive response to chronic radiation exposure in interventional cardiologists.  

PubMed

Aims Invasive cardiologists are the most exposed to ionizing radiation among health professionals and show an increased rate of somatic DNA damage. To evaluate the effects of chronic low-dose exposure to ionizing radiation on redox state and apoptotic activation. Methods and results We enrolled 10 healthy exposed professionals (all interventional cardiologists, Group II, exposed: age = 38 ± 5 years) and 10 age- and gender-matched unexposed controls (Group I, non-exposed). Exposed subjects had a median exposure of 4 mSv/year (range 1-8) by film badge dosimetry (below lead apron). We measured reduced glutathione (GSH, a marker of antioxidant response) in erythrocytes and plasma generation of hydrogen peroxide (a marker of oxyradical stress) by ferrous oxidation-xylenol orange assay in plasma. In both groups, lymphocytes were isolated and caspase-3 activity (a marker of apoptotic response) measured at baseline and following 2 Gy in vitro irradiation. Exposed subjects showed a three-fold increase in hydrogen peroxide (Group I = 2.21 ± 1.03 vs. II = 6.51 ± 1.55 ?M H(2)O(2) equivalents) and a 1.7-fold increase in GSH (I = 12.37 ± 1.22 vs. II = 20.61 ± 2.16 mM). Exposed subjects also showed higher values of caspase-3 activity, both at baseline and-more strikingly-following high-dose radiation challenge. Conclusion In interventional cardiologists, chronic exposure to low-dose radiation is associated with an altered redox balance mirrored by an increase in hydrogen peroxide and with two possibly adaptive cellular responses: (i) an enhanced antioxidant defence (increase in GSH, counteracting increased oxyradical stress) and (ii) an increased susceptibility to apoptotic induction which might efficiently remove genetically damaged cells. PMID:21862464

Russo, Gian Luigi; Tedesco, Idolo; Russo, Maria; Cioppa, Angelo; Andreassi, Maria Grazia; Picano, Eugenio

2012-02-01

291

Interim report of the Advisory Committee on human radiation experiments.  

National Technical Information Service (NTIS)

The Advisory Committee on Human Radiation Experiments was created by President Clinton to advise the Human Radiation Interagency Working Group on the ethical and scientific criteria applicable to human radiation experiments carried out or sponsored by the...

1994-01-01

292

[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

293

Titanium-Water Thermosyphon Gamma Radiation Exposure and Results  

NASA Technical Reports Server (NTRS)

Titanium-water thermosyphons are being considered for use in heat rejection systems for fission power systems. Their proximity to the nuclear reactor will result in some gamma irradiation. Noncondensable gas formation from radiation-induced breakdown of water over time may render portions of the thermosyphon condenser inoperable. A series of developmental thermosyphons were operated at nominal operating temperature under accelerated gamma irradiation, with exposures on the same order of magnitude as that expected in 8 years of heat rejection system operation. Temperature data were obtained during exposure at three locations on each thermosyphon: evaporator, condenser, and condenser end cap. Some noncondensable gas was evident; however, thermosyphon performance was not affected because the noncondensable gas was compressed into the fill tube region at the top of the thermosyphon, away from the heat rejecting fin. The trend appeared to be an increasing amount of noncondensable gas formation with increasing gamma irradiation dose. Hydrogen is thought to be the most likely candidate for the noncondensable gas and hydrogen is known to diffuse through grain boundaries. Post-exposure evaluation of one thermosyphon in a vacuum chamber and at temperature revealed that the noncondensable gas diffused out of the thermosyphon over a relatively short period of time. Further research shows a number of experimental and theoretical examples of radiolysis occurring through gamma radiation alone in pure water.

Sanzi, James, L.A; Jaworske, Donald, A.; Goodenow, Debra, A.

2012-01-01

294

Radiation exposure assessment for portsmouth naval shipyard health studies.  

PubMed

Occupational radiation exposures of 13,475 civilian nuclear shipyard workers were investigated as part of a retrospective mortality study. Estimates of annual, cumulative and collective doses were tabulated for future dose-response analysis. Record sets were assembled and amended through range checks, examination of distributions and inspection. Methods were developed to adjust for administrative overestimates and dose from previous employment. Uncertainties from doses below the recording threshold were estimated. Low-dose protracted radiation exposures from submarine overhaul and repair predominated. Cumulative doses are best approximated by a hybrid log-normal distribution with arithmetic mean and median values of 20.59 and 3.24 mSv, respectively. The distribution is highly skewed with more than half the workers having cumulative doses <10 mSv and >95% having doses <100 mSv. The maximum cumulative dose is estimated at 649.39 mSv from 15 person-years of exposure. The collective dose was 277.42 person-Sv with 96.8% attributed to employment at Portsmouth Naval Shipyard. PMID:15266069

Daniels, R D; Taulbee, T D; Chen, P

2004-01-01

295

Thyroid Carcinoma Secondary to Radiation Cloud Exposure from the Chernobyl Incident of 1986: A Case Study  

PubMed Central

The Chernobyl accident of 1986 exposed most if not all of Europe to a blanket of radiation, creating a melting pot of human exposure sequelae that is still showing up in our medical clinics today. In our particular clinic, a young woman of 29 years presented with most of her extended family in attendance. The young woman was born and raised in northern Italy until the age of seven when she left and immigrated to the United States leaving most of her family behind. Shortly after the Chernobyl accident, 5 members of her family, all woman including her own mother, were diagnosed with papillary thyroid carcinoma. Twenty-two years later, this same young woman came into the clinic with papillary thyroid carcinoma, making her the sixth member of her family. This case report illustrates the patient's history with her radiation exposure while talking in depth about the source, Chernobyl.

Atkinson, Andrew L.; Rosenthal, Andrew

2010-01-01

296

Estimated Radiation Exposure from Medical Imaging in Hemodialysis Patients  

PubMed Central

Radiation exposure accompanying medical imaging associates with cancer risk. Patients with recurrent or chronic diseases may be especially at risk, because they may undergo more of these procedures. The aim of this study was to assess the individual cumulative effective doses (CEDs), which quantify radiation from medical imaging procedures, in a cohort of 106 hemodialysis patients during a median follow-up of 3 years. We retrospectively calculated individual radiation exposures by collecting the number and type of radiologic procedures from hospital records. We also estimated organ doses for computed tomography procedures. The mean and median annual CEDs were 21.9 and 11.7 mSv per patient-year, respectively. The mean and median total CEDs per patient during the study period were 57.7 and 27.3 mSv, respectively. By radiation dose group, we classified 22 patients as low (<3 mSv/yr), 51 as moderate (3 to <20 mSv/yr), 22 as high (20 to <50 mSv/yr), and 11 as very high (?50 mSv/yr). Seventeen patients had a total CED >100 mSv, a value associated with a substantial increase in risk for cancer- mortality. Of the total CED,s 76% was a result of CT scanning. The annual CED significantly associated with age and transplant waitlist status. In summary, this study shows that a significant fraction of surviving hemodialysis patients during a 3-year period receives estimated radiation doses that may put them at an increased risk for cancer.

De Mauri, Andreana; Chiarinotti, Doriana; Matheoud, Roberta; Carriero, Alessandro; De Leo, Martino

2011-01-01

297

Nine-year evaluation of emergency department personnel exposure to ionizing radiation  

SciTech Connect

Emergency department personnel experience potential occupational hazards from exposure to ionizing radiation (x-rays). To assess this risk, ionizing radiation exposure was analyzed during a nine-year period for 128 ED personnel. The group consisted of 21 physicians, 92 nurses, and 15 ancillary personnel. Exposure was measured for both penetrating and nonpenetrating radiation using standard film dosimeter badges. Film badge use compliance was 66.7% for physicians, 86.2% for nurses, and 86.7% for ancillary personnel. Penetrating radiation exposure averaged 0.12 mrem/month for physicians, 0.70 mrem/month for nurses, and 0 mrem/month for ancillary personnel, all less than the average natural background exposure. We concluded that if standard radiation precautions are taken, the occupational risk from ionizing radiation exposure to personnel in the ED is minimal, and that routine monitoring of radiation exposure of ED personnel is unnecessary.

Grazer, R.E.; Meislin, H.W.; Westerman, B.R.; Criss, E.A.

1987-03-01

298

European measurements of aircraft crew exposure to cosmic radiation.  

PubMed

For more than 5 y, the European Commission has supported research into scientific and technical aspects of cosmic-ray dosimetry at flight altitudes in civil radiation. This has been in response to legislation to regard exposure of aircraft crew as occupational, following the recommendations of the International Commission on Radiological Protection in Publication 60. The response to increased public interest and concern, and in anticipation of European and national current work, within a total of three multi-national, multi-partner research contracts, is based on a comprehensive approach including measurements with dosimetric and spectrometric instruments during flights, at high-mountain altitudes, and in a high-energy radiation reference field at CERN, as well as cosmic-ray transport calculations. The work involves scientists in the fields of neutron physics, cosmic-ray physics, and general dosimetry. A detailed set of measurements has been obtained by employing a wide range of detectors on several routes, both on subsonic and supersonic aircraft. Many of the measurements were made simultaneously by several instruments allowing the intercomparison of results. This paper presents a brief overview of results obtained. It demonstrates that the knowledge about radiation fields and on exposure data has been substantially consolidated and that the available data provide an adequate basis for dose assessments of aircraft crew, which will be legally required in the European Union after 13 May 2000. PMID:11045531

Menzel, H G; O'Sullivan, D; Beck, P; Bartlett, D

2000-11-01

299

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

300

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

301

A novel method to calculate solar UV exposure relevant to vitamin D production in humans.  

PubMed

We present a novel method to calculate vitamin D3 -weighted exposure by integrating the incident solar spectral radiance over all relevant parts of the human body. Earlier investigations are based on the irradiance on surfaces, whereas our calculated exposure of a voxel model of a human takes into account the complex geometry of the radiation field. Assuming that sufficient vitamin D3 (1000 international units) can be produced within the human body in one minute for a completely uncovered body in vertical posture in summer at midlatitudes (e.g. Rome, June 21, noon, UV index of 10), we calculate the exposure times needed in other situations or seasons to gain enough vitamin D3 . Our calculations show that the UV index is not a good indicator for the exposure which depends on the orientation of the body (e.g. vertical (standing) or horizontal (lying down) posture). Without clothing the exposure is dominated by diffuse sky radiation and it is nearly irrelevant how the body in vertical posture is oriented toward the sun. At the winter solstice (December 21, noon, cloudy) at least in central Europe sufficient vitamin D3 cannot be obtained with realistic clothing, even if the exposure were extended to all daylight hours. PMID:23517086

Seckmeyer, Gunther; Schrempf, Michael; Wieczorek, Anna; Riechelmann, Stefan; Graw, Kathrin; Seckmeyer, Stefan; Zankl, Maria

2013-01-01

302

Cancer risk from exposure to galactic cosmic rays: implications for space exploration by human beings.  

PubMed

Space programmes are shifting toward planetary exploration, and in particular towards missions by human beings to the moon and Mars. However, exposure to space radiation is an important barrier to exploration of the solar system by human beings because of the biological effects of high-energy heavy ions. These ions have a high charge and energy, are the main contributors to radiation risk in deep space, and their biological effects are understood poorly. Predictions of the nature and magnitude of risks posed by exposure to radiation in space are subject to many uncertainties. In recent years, worldwide efforts have focussed on an increased understanding of the oncogenic potential of galactic cosmic rays. A review of the new results in this specialty will be presented here. PMID:16648048

Cucinotta, Francis A; Durante, Marco

2006-05-01

303

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

304

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...

305

[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

306

Individual differences in attentional deficits and dopaminergic protein levels following exposure to proton radiation.  

PubMed

To assess the possible neurobehavioral performance risks to astronauts from living in a space radiation environment during long-duration exploration missions, the effects of head-only proton irradiation (150 MeV/n) at low levels (25-50 cGy, approximating an astronaut's exposure during a 2-year planetary mission) were examined in adult male Long-Evans rats performing an analog of the human psychomotor vigilance test (PVT). The rodent version of PVT or rPVT tracks performance variables analogous to the human PVT, including selective attention/inattention, inhibitory control ("impulsivity") and psychomotor speed. Exposure to head-only proton radiation (25, 50, 100 or 200 cGy) disrupted rPVT performance (i.e., decreased accuracy, increased premature responding, elevated lapses in attention and slowed reaction times) over the 250 day testing period. However, the performance decrements only occurred in a subgroup of animals at each exposure level, that is, the severity of the rPVT performance deficit was unrelated to proton exposure level. Analysis of brain tissue from irradiated and control rats indicated that only rats with rPVT performance deficits displayed changes in the levels of the dopamine transporter and, to a lesser extent, the D? receptor. Additional animals trained to perform a line discrimination task measuring basic and reversal learning showed no behavioral effects over the same exposure levels, suggesting a specificity of the proton exposure effects to attentional deficits and supporting the rPVT as a sensitive neurobehavioral assay. PMID:24611657

Davis, Catherine M; DeCicco-Skinner, Kathleen L; Roma, Peter G; Hienz, Robert D

2014-03-01

307

ICRP, 123. Assessment of radiation exposure of astronauts in space. ICRP Publication 123.  

PubMed

During their occupational activities in space, astronauts are exposed to ionising radiation from natural radiation sources present in this environment. They are, however, not usually classified as being occupationally exposed in the sense of the general ICRP system for radiation protection of workers applied on Earth. The exposure assessment and risk-related approach described in this report is clearly restricted to the special situation in space, and should not be applied to any other exposure situation on Earth. The report describes the terms and methods used to assess the radiation exposure of astronauts, and provides data for the assessment of organ doses. Chapter 1 describes the specific situation of astronauts in space, and the differences in the radiation fields compared with those on Earth. In Chapter 2, the radiation fields in space are described in detail, including galactic cosmic radiation, radiation from the Sun and its special solar particle events, and the radiation belts surrounding the Earth. Chapter 3 deals with the quantities used in radiological protection, describing the Publication 103 (ICRP, 2007) system of dose quantities, and subsequently presenting the special approach for applications in space; due to the strong contribution of heavy ions in the radiation field, radiation weighting is based on the radiation quality factor, Q, instead of the radiation weighting factor, wR. In Chapter 4, the methods of fluence and dose measurement in space are described, including instrumentation for fluence measurements, radiation spectrometry, and area and individual monitoring. The use of biomarkers for the assessment of mission doses is also described. The methods of determining quantities describing the radiation fields within a spacecraft are given in Chapter 5. Radiation transport calculations are the most important tool. Some physical data used in radiation transport codes are presented, and the various codes used for calculations in high-energy radiation fields in space are described. Results of calculations and measurements of radiation fields in spacecraft are given. Some data for shielding possibilities are also presented. Chapter 6 addresses methods of determining mean absorbed doses and dose equivalents in organs and tissues of the human body. Calculated conversion coefficients of fluence to mean absorbed dose in an organ or tissue are given for heavy ions up to Z=28 for energies from 10 MeV/u to 100 GeV/u. For the same set of ions and ion energies, mean quality factors in organs and tissues are presented using, on the one hand, the Q(L) function defined in Publication 60 (ICRP, 1991), and, on the other hand, a Q function proposed by the National Aeronautics and Space Administration. Doses in the body obtained by measurements are compared with results from calculations, and biodosimetric measurements for the assessment of mission doses are also presented. In Chapter 7, operational measures are considered for assessment of the exposure of astronauts during space missions. This includes preflight mission design, area and individual monitoring during flights in space, and dose recording. The importance of the magnitude of uncertainties in dose assessment is considered. Annex A shows conversion coefficients and mean quality factors for protons, charged pions, neutrons, alpha particles, and heavy ions(2 < Z ?2 8), and particle energies up to 100 GeV/u. PMID:23958389

Dietze, G; Bartlett, D T; Cool, D A; Cucinotta, F A; Jia, X; McAulay, I R; Pelliccioni, M; Petrov, V; Reitz, G; Sato, T

2013-08-01

308

Medical Diagnostic Radiation Exposures and Risk of Gliomas  

PubMed Central

High-dose ionizing radiation is an established risk factor for glioma, but it remains unknown whether moderate- and low-dose radiation increase glioma risk. In this analysis, we assessed the evidence that self-reported exposures to diagnostic ionizing radiation, including computerized tomography (CT) scans, is associated with increased risk of adult glioma. While no independent association was observed for CT scans alone (3+ scans compared to none P = 0.08 and 1–2 scans compared to none P = 0.68), our findings suggest an increased risk of adult gliomas with cumulative exposure to three or more CT scans to the head and neck region (OR = 1.97, 95% CI: 0.92–4.23) limited to those who reported a family history of cancer: the P value for the interaction between having three or more CT scans and family history of cancer was 0.08. The stratum-specific adjusted OR for those with family history of cancer was more than three times that for the sub-group without family history of cancer. While there is some potential for symptom-related bias, one might expect this to be present for all diagnostic procedures rather than specific to one procedure. The interaction between CT scans and glioma with family history of cancer supports the biological plausibility of our findings, because similar results have been found for breast cancer and radiation. This observational data will increase awareness about potential risks associated with CT scans and the need to minimize the use of unnecessary examinations.

Davis, Faith; Il'yasova, Dora; Rankin, Kristin; McCarthy, Bridget; Bigner, Darell D.

2011-01-01

309

Exposure to galactic cosmic radiation and solar energetic particles.  

PubMed

Several investigations of the radiation field at aircraft altitudes have been undertaken during solar cycle 23 which occurred in the period 1993-2003. The radiation field is produced by the passage of galactic cosmic rays and their nuclear reaction products as well as solar energetic particles through the Earth's atmosphere. Galactic cosmic rays reach a maximum intensity when the sun is least active and are at minimum intensity during solar maximum period. During solar maximum an increased number of coronal mass ejections and solar flares produce high energy solar particles which can also penetrate down to aircraft altitudes. It is found that the very complicated field resulting from these processes varies with altitude, latitude and stage of solar cycle. By employing several active and passive detectors, the whole range of radiation types and energies were encompassed. In-flight data was obtained with the co-operation of many airlines and NASA. The EURADOS Aircraft Crew in-flight data base was used for comparison with the predictions of various computer codes. A brief outline of some recent studies of exposure to radiation in Earth orbit will conclude this contribution. PMID:17846031

O'Sullivan, D

2007-01-01

310

Accidental radiation exposure leading to non-healing ulcers.  

PubMed

Two patients with accidental radiation injury presented at the Sir Ganga Ram Hospital. The first patient, a 41-year-old male, presented with a large necrotic patch on his right gluteal region, which was debrided. Due to the progressive nature of the injury, he developed further necrosis and a non-healing ulcer over the right gluteal region, which was further debrided and covered with a tensor fascia lata flap. Further necrosis over the ischial region was debrided and covered with a pedicled gracilis muscle flap, following which he again required debridement and flap cover for the residual area, which then finally healed. The second patient had a history of radiation exposure followed by a non-healing ulcer on right arm. He was managed by debridement and flap coverage in a single sitting. These two cases suggest that wide excision, thorough debridement and coverage with vascularised tissue are effective in treating radiation ulcers and emphasise that all radiation sources and their management should be strictly controlled. PMID:23103484

Gambhir, S; Mangal, M; Gupta, A; Shah, A

2012-10-01

311

Recommendations on limits for exposure to ionizing radiation  

SciTech Connect

The National Council on Radiation Protection and Measurements (NCRP) published its last complete set of basic recommendations specifying limits for ionizing radiation in 1971, in previous NCRP Report, Basic Radiation Protection Criteria (NCRP, 1971a). Although this Report is not intended to be a complete revision of NCRP Report No. 39, in that the background material in that report has not been revised, the recommendations contained herein replace all of the recommendations given in the 1971 Report. In a previous NCRP Report, some estimates of risk were presented, but these were not explicitly utilized in the derivation of recommended dose equivalent limits. The International Commission on Radiological Protection (ICRP), in its Publication 26, presented risk estimates to demonstrate the acceptability of its basic dose equivalent limits (ICRP, 1977a); however, the ICRP did not derive their dose equivalent limits from those risk estimates. Subsequent updating of portions of ICRP Publication 26 have not brought about any closer coupling between their risk estimates and their dose equivalent limits. The Council believes that additional review and evaluation are required prior to the introduction of a radiation protection system in which the limitation of exposure is based solely on risk.

Not Available

1987-01-01

312

On the Use of SRIM for Computing Radiation Damage Exposure  

SciTech Connect

The SRIM (formerly TRIM) Monte Carlo simulation code is widely used to compute a number of parameters relevant to ion beam implantation and ion beam processing of materials. It also has the capability to compute a common radiation damage exposure unit known as atomic displacements per atom (dpa). Since dpa is a standard measure of primary radiation damage production, most researchers who employ ion beams as a tool for inducing radiation damage in materials use SRIM to determine the dpa associated with their irradiations. The use of SRIM for this purpose has been evaluated and comparisons have been made with an internationally-recognized standard definition of dpa, as well as more detailed atomistic simulations of atomic displacement cascades. Differences between the standard and SRIM-based dpa are discussed and recommendations for future usage of SRIM in radiation damage studies are made. In particular, it is recommended that when direct comparisons between ion and neutron data are intended, the Kinchin-Pease option of SRIM should be selected.

Stoller, Roger E.; Toloczko, Mychailo B.; Was, Gary S.; Certain, Alicia G.; Dwaraknath, S.; Garner, Frank A.

2013-06-06

313

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

314

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...

315

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...

316

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...

317

Assessing human exposure to airborne pollutants: Advances and opportunities  

Microsoft Academic Search

A committee which was convened by the National Research Council, recently completed an analysis of new methods and technologies for assessing exposure to air pollutants. The committee identified three major ways of determining human exposure to airborne pollutants. Monitoring the air around an individual with a portable personal air sampler is, of course, the most comprehensive and most accurate. It

Lioy

1991-01-01

318

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...

319

ENVIRONMENTAL MONITORING AND HUMAN EXPOSURE ASSESSMENT USING IMMUNOCHEMICAL TECHNIQUES  

EPA Science Inventory

The use of immunochemical technologies including, but not limited to, immunoassays is expanding to include various aspects of environmental analysis. Ultimately, the basis for environmental investigations is concern about human and ecological exposure to potentially toxic compoun...

320

LESSONS LEARNED FROM THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS)  

EPA Science Inventory

Three NHEXAS Studies were conducted from 1995-1997 to evaluate total human exposure to multiple chemicals on community and regional scales. EPA established cooperative agreements with three Consortia to conduct three interrelated NHEXAS field studies. The University of Arizona...

321

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

322

Estimating the radiation absorbed by a human.  

PubMed

The complexities of the interactions between long- and short-wave radiation fluxes and the human body make it inherently difficult to estimate precisely the total radiation absorbed (R) by a human in an outdoor environment. The purpose of this project was to assess and compare three methods to estimate the radiation absorbed by a human in an outdoor environment, and to compare the impact of applying various skin and clothing albedos (alpha ( h )) on R. Field tests were conducted under both clear and overcast skies to evaluate the performance of applying a cylindrical radiation thermometer (CRT), net radiometer, and a theoretical estimation model to predict R. Three albedos were evaluated: light (alpha ( h ) = 0.57), medium (alpha ( h ) = 0.37), and dark (alpha ( h ) = 0.21). During the sampling periods, the range of error between the methods used to estimate the radiation absorbed by a cylindrical body under clear and overcast skies ranged from 3 to 8%. Clothing and skin albedo had a substantial impact on R, with the mean change in R between the darkest and lightest albedos ranging from 115 to 157 W m( - 2) over the sampling period. Radiation is one of the most important variables to consider in outdoor thermal comfort research, as R is often the largest contributor to the human energy balance equation. The methods outlined and assessed in this study can be conveniently applied to provide reliable estimates of the radiation absorbed by a human in an outdoor environment. PMID:18273649

Kenny, Natasha A; Warland, Jon S; Brown, Robert D; Gillespie, Terry G

2008-07-01

323

Estimating the radiation absorbed by a human  

NASA Astrophysics Data System (ADS)

The complexities of the interactions between long- and short-wave radiation fluxes and the human body make it inherently difficult to estimate precisely the total radiation absorbed ( R) by a human in an outdoor environment. The purpose of this project was to assess and compare three methods to estimate the radiation absorbed by a human in an outdoor environment, and to compare the impact of applying various skin and clothing albedos ( ? h ) on R. Field tests were conducted under both clear and overcast skies to evaluate the performance of applying a cylindrical radiation thermometer (CRT), net radiometer, and a theoretical estimation model to predict R. Three albedos were evaluated: light ( ? h = 0.57), medium ( ? h = 0.37), and dark ( ? h = 0.21). During the sampling periods, the range of error between the methods used to estimate the radiation absorbed by a cylindrical body under clear and overcast skies ranged from 3 to 8%. Clothing and skin albedo had a substantial impact on R, with the mean change in R between the darkest and lightest albedos ranging from 115 to 157 W m - 2 over the sampling period. Radiation is one of the most important variables to consider in outdoor thermal comfort research, as R is often the largest contributor to the human energy balance equation. The methods outlined and assessed in this study can be conveniently applied to provide reliable estimates of the radiation absorbed by a human in an outdoor environment.

Kenny, Natasha A.; Warland, Jon S.; Brown, Robert D.; Gillespie, Terry G.

2008-07-01

324

1.8 GHz Radio Frequency signal radiation effects on human health  

Microsoft Academic Search

Radio Frequency (RF) radiation effects are strictly relying on few critical factors, ie frequency, period of exposure and distance. Certain frequency ranges are absorbed in body tissue more than the other frequency range. The second factor is the duration of exposure. Where, over the period of time, the body will absorb more RF frequencies which hence will worsened the human

Azizah Ahmad; Rusnani Ariffin; Norhayati Mohd Noor; Meor Adzmey Sagiruddin

2011-01-01

325

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...

326

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.

Ron, Elaine; Brenner, Alina

2013-01-01

327

The assessment of radiation exposures in native American communities from nuclear weapons testing in Nevada  

Microsoft Academic Search

Native Americans residing in a broad region downwind from the Nevada Test Site during the 1950s and 1960s received significant radiation exposures from nuclear weapons testing. Because of differences in diet, activities, and housing, their radiation exposures are only very imperfectly represented in the Department of Energy dose reconstructions. There are important missing pathways, including exposures to radioactive iodine from

Eric Frohmberg; Robert Goble; Virginia Sanchez; Dianne Quigley

2000-01-01

328

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

329

Prenatal exposure to ionizing radiation and subsequent development of seizures  

SciTech Connect

Seizures are a frequent sequela of impaired brain development and can be expected to affect more children with radiation-related brain damage than children without such damage. This report deals with the incidence and type of seizures among survivors prenatally exposed to the atomic bombing of Hiroshima and Nagasaki, and their association with specific stages of prenatal development at the time of irradiation. Fetal radiation dose was assumed to be equal to the dose to the maternal uterus. Seizures here include all references in the clinical record to seizure, epilepsy, or convulsion. Histories of seizures were obtained at biennial routine clinical examinations starting at about the age of 2 years. These clinical records were used to classify seizures as febrile or unprovoked (without precipitating cause). No seizures were ascertained among subjects exposed 0-7 weeks after fertilization at doses higher than 0.10 Gy. The incidence of seizures was highest with irradiation at the eighth through the 15th week after fertilization among subjects with doses exceeding 0.10 Gy and was linearly related to the level of fetal exposure. This obtains for all seizures without regard to the presence of fever or precipitating causes, and for unprovoked seizures. When the 22 cases of severe mental retardation were excluded, the increase in seizures was only suggestively significant and only for unprovoked seizures. After exposure at later stages of development, there was no increase in recorded seizures.

Dunn, K.; Yoshimaru, H.; Otake, M.; Annegers, J.F.; Schull, W.J. (Radiation Effects Research Foundation, Hiroshima (Japan))

1990-01-01

330

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

331

Exposure limits for ultra-short wave radiation in work environments.  

PubMed

Exposure limit values for ultra-short wave radiation of humans were derived on the basis of epidemiological survey and experimental exposure of rabbits. Eighteen male rabbits were divided into 4 groups randomly. Three groups were irradiated with ultra-short waves (100 MHz) at 35, 1.5-3.5, and 0.07 mW/cm2 power density in an E-polarized TEM Cell at 24 +/- 4 degrees C ambient temperature. The last group in a sham chamber served as controls. Irradiation was performed 3 hours per day, 5 days per week for 24 weeks. Thermal effects occurred in the group irradiated at 35 mW/cm2. The thermal threshold limit value was set at 1.5 mW/cm2. An epidemiological survey was carried out on 136 factory workers and TV operators exposed over one year to ultra-short wave radiation at 0.2 mW/cm2. They were compared with 108 controls. The only complaint of the exposed group was neurosis. The exposure limit value (ELV) to short wave radiation was set at 0.2 mW/cm2 by using a 15- and 20-fold safety factor. PMID:7724881

Zhao, Z; Zhang, S; Wang, S; Yao, Z; Zho, H; Tao, S; Tao, L

1994-01-01

332

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

333

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

334

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 ...

335

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

336

Radiation dose assessment of exposure to depleted uranium.  

PubMed

Depleted uranium (DU) is claimed to contribute to human health problems, known as the Gulf War Syndrome and the Balkan Syndrome. Quantitative radiation dose is required to estimate the health risk of DU materials. The influences of the solubility parameters in the human alimentary tract and the respiratory tract systems and the aerosol particles size on the radiation dose of DU materials were evaluated. The dose conversion factor of daily urinary excretion of DU is provided. The retention and excretion of DU in the human body after a contamination at a wound site were predicted. Dose coefficients of DU after ingestion and inhalation were calculated using the solubility parameters of the DU corrosion products in simulated gastric and simulated lung fluid, which were determined in the Helmholtz Zentrum München. (238)U is the main radiation dose contributor per 1 Bq of DU materials. The dose coefficients of DU materials were estimated to be 3.5 x 10(-8) and 2.1 x 10(-6) Sv Bq(-1) after ingestion and inhalation for members of the public. The ingestion dose coefficient of DU materials is about 75% of the natural uranium value. The inhalation dose coefficient of DU material is in between those for Type M and Type S according to the category for inhaled materials defined by the International Commission on Radiological Protection. Radiation dose possibly received from DU materials can directly be estimated by using the dose conversion factor provided in this study, if daily urinary excretion of DU is measured. PMID:18596688

Li, Wei Bo; Gerstmann, Udo C; Höllriegl, Vera; Szymczak, Wilfried; Roth, Paul; Hoeschen, Christoph; Oeh, Uwe

2009-07-01

337

[Assessment of exposure to laser radiation in research laboratories].  

PubMed

The problem of laser safety is now topical due to the wide use of laser systems in different working environments. The program of prevention and protection prescribed by law 626/94 gives general rules for the elimination (where possible) and/or reduction of risk factors. For this purpose, it is important to determine the parameters that characterize such risks. The Maximum Permissible Exposure (MPE) and the Nominal Ocular Hazard Distance (NOHD) are the most important parameters of laser safety. The evaluation of these parameters requires a detailed knowledge of the standards and of the various techniques which are necessary to measure them. In particular, the MPE parameters are obtained by CEI EN 60825-1 standard in relation to wavelength and emission duration of the investigated laser. Exposure to laser radiation is usually measured in terms of irradiance (W/m2) or radiant exposure (J/m2). The experimental values of irradiance must be compared with the MPE parameters obtained by safety standards. When the values of irradiance exceed the MPE parameters then the NOHD values must to be calculated. The aim of this paper is to offer a general view of the methods for measuring the above-mentioned parameters for the laser sources that are most widely used in research environments and to compare such parameters with those recommended by safety standards. Our results indicate that for almost all the laser sources analysed, the measured exposure values were greater than the MPE recommended by standards, both for eyes and skin. High values of NOHD indicate that it is necessary to use eye protection, beam stops or attenuators at the end of the useful beam path in normal working conditions and especially in research laboratories in which these conditions can often change. PMID:11515152

Falco, M D; Lepore, M; Indovina, P L

2001-01-01

338

Radiation metabolomics. 2. Dose- and time-dependent urinary excretion of deaminated purines and pyrimidines after sublethal gamma-radiation exposure in mice.  

PubMed

Gamma-radiation exposure of humans is a major public health concern as the threat of terrorism and potential hostile use of radiological devices increases worldwide. We report here the effects of sublethal gamma-radiation exposure on the mouse urinary metabolome determined using ultra-performance liquid chromatography-coupled time-of-flight mass spectrometry-based metabolomics. Five urinary biomarkers of sublethal radiation exposure that were statistically significantly elevated during the first 24 h after exposure to doses ranging from 1 to 3 Gy were unequivocally identified by tandem mass spectrometry. These are deaminated purine and pyrimidine derivatives, namely, thymidine, 2'-deoxyuridine, 2'-deoxyxanthosine, xanthine and xanthosine. Furthermore, the aminopyrimidine 2'-deoxycytidine appeared to display reduced urinary excretion at 2 and 3 Gy. The elevated biomarkers displayed a time-dependent excretion, peaking in urine at 8-12 h but returning to baseline by 36 h after exposure. It is proposed that 2'-deoxyuridine and 2'-deoxyxanthosine arise as a result of gamma irradiation by nitrosative deamination of 2'-deoxycytidine and 2'-deoxyguanosine, respectively, and that this further leads to increased synthesis of thymidine, xanthine and xanthosine. The urinary excretion of deaminated purines and pyrimidines, at the expense of aminopurines and aminopyrimidines, appears to form the core of the urinary radiation metabolomic signature of mice exposed to sublethal doses of ionizing radiation. PMID:19580506

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

2009-07-01

339

Radiation Metabolomics. 2. Dose- and Time-Dependent Urinary Excretion of Deaminated Purines and Pyrimidines after Sublethal Gamma-Radiation Exposure in Mice  

PubMed Central

Gamma-radiation exposure of humans is a major public health concern as the threat of terrorism and potential hostile use of radiological devices increases worldwide. We report here the effects of sublethal ?-radiation exposure on the mouse urinary metabolome determined using ultra-performance liquid chromatography-coupled time-of-flight mass spectrometry-based metabolomics. Five urinary biomarkers of sublethal radiation exposure that were statistically significantly elevated during the first 24 h after exposure to doses ranging from 1 to 3 Gy were unequivocally identified by tandem mass spectrometry. These are deaminated purine and pyrimidine derivatives, namely, thymidine, 2?-deoxyuridine, 2?-deoxyxanthosine, xanthine and xanthosine. Furthermore, the aminopyrimidine 2?-deoxycytidine appeared to display reduced urinary excretion at 2 and 3 Gy. The elevated biomarkers displayed a time-dependent excretion, peaking in urine at 8–12 h but returning to baseline by 36 h after exposure. It is proposed that 2?-deoxyuridine and 2?-deoxyxanthosine arise as a result of ? irradiation by nitrosative deamination of 2?-deoxycytidine and 2?-deoxyguanosine, respectively, and that this further leads to increased synthesis of thymidine, xanthine and xanthosine. The urinary excretion of deaminated purines and pyrimidines, at the expense of aminopurines and aminopyrimidines, appears to form the core of the urinary radiation metabolomic signature of mice exposed to sublethal doses of ionizing radiation.

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

2009-01-01

340

Wood smoke in a controlled exposure experiment with human volunteers.  

PubMed

Exposure to wood smoke in the general population is increasing and concurrently, also our awareness. This article describes a wood-smoke generating system for studying human exposure to wood smoke and symptoms related to this exposure. Twenty nonsmoking atopic human participants with normal lung function and normal bronchial reactivity were randomly exposed for 3?h at three different exposure conditions; clean filtered air (control exposure) and wood smoke with a characteristic particulate matter (PM) concentration of 200 µg/m³ (low) and 400 µg/m³ (high) under controlled environmental conditions. The range for PM?.? load observed for single experiments was 165-303 µg/m³ for the low exposure and 205-662 µg/m³ for the high exposure, whereas particle loads during clean air exposure most often were below the detection limit (< 20 µg/m³). Health effects were evaluated in relation to rated changes in symptoms and environmental perception using a computerized questionnaire and a potentiometer. Subjective symptoms were generally weak, but when combining the effect of each of the symptoms into categorical symptom indices, significant effects were found for "environmental perception" (p?=?0.0007), "irritative body perceptions" (p?=?0.0127), "psychological/neurological effects" (p?=?0.0075) and "weak inflammatory responses" (p?=?0.0003). Furthermore, significant effects (p?=?0.0192) on self-reported general mucosa irritation were found. In conclusion, exposure to wood smoke affected symptom rating and caused irritated mucosas in humans. The knowledge gained in this study on subjective-rated symptoms may be important for understanding human response to wood-smoke exposure. PMID:21506878

Riddervold, I S; Bønløkke, J H; Mølhave, L; Massling, A; Jensen, B; Grønborg, T K; Bossi, R; Forchhammer, L; Kjærgaard, S K; Sigsgaard, T

2011-04-01

341

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.

2014-01-01

342

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,...

343

Quantifying lifetime exposure to ultraviolet radiation in the epidemiology of cutaneous malignant melanoma: A pilot study.  

National Technical Information Service (NTIS)

This pilot study uses a unique method to calculate cumulative lifetime exposure to, ultraviolet radiation-b to determine if this refined method would indicate differences in lifetime cumulative UVB exposure between age and sex matched controls. Forty-four...

C. S. Lea S. Selvin P. A. Buffler J. Scotto M. Berwick

1992-01-01

344

Simulation of Spatial and Temporal Radiation Exposures for ISS in the South Atlantic Anomaly.  

National Technical Information Service (NTIS)

The International Space Station (ISS) living areas receive the preponderance of ionizing radiation exposure from Galactic Cosmic Rays (GCR) and geomagnetically trapped protons. Practically all trapped proton exposure occurs when the ISS passes through the...

B. M. Anderson J. E. Nealy N. J. Luetke C. A. Sandridge G. E. Qualls

2004-01-01

345

Cigarette Smoking and Radiation Exposure in Relation to Cancer Mortality, Hiroshima and Nagasaki.  

National Technical Information Service (NTIS)

Cancer mortality among 40,498 Hiroshima and Nagasaki residents was examined in relation to cigarette smoking habits and estimated atomic bomb radiation exposure. Relative risk models that are either multiplicative or additive in the two exposures (smoking...

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

1983-01-01

346

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

347

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...

348

Human exposure to traffic pollution. Experience from Danish studies  

Microsoft Academic Search

Air pollution may have severe long-term as well as short-term health effects. The determination of possible links between pollution levels and impact on human health is, how- ever, not a straightforward task. A key problem is the assessment of human exposure to ambi- ent pollution levels. In later years, the possible role of particulate pollution as a health haz- ard

Ole Hertel; Steen Solvang Jensen; Helle Vibeke Andersen; Finn Palmgren; Peter Wåhlin; Henrik Skov; Ivan Vejsgaard Nielsen; Mette Sørensen; Steffen Loft; Ole Raaschou-Nielsen

2001-01-01

349

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...

350

Identification of Gene Markers for Formaldehyde Exposure in Humans  

PubMed Central

Background Formaldehyde (FA) is classified as a human carcinogen and has been linked to increased leukemia rates in some epidemiologic studies. Inhalation of FA induces sensory irritation at relatively low concentrations. However, little is known concerning the cellular alterations observed after FA exposure in humans. Objectives Our aim was to profile global gene expression in Hs 680.Tr human tracheal fibroblasts exposed to FA and to develop biomarkers for the evaluation of FA exposure in humans. Methods and Results We used gene expression analysis, and identified 54 genes designated as FA responsive. On the basis of these data, we conducted an exploratory analysis of the expression of these genes in human subjects exposed to high or low levels of FA. We monitored FA exposure by measuring the urinary concentration of thiazolidine-4-carboxylate (TZCA), a stable and quantitative cysteinyl adduct of FA. Nine genes were selected for real-time PCR analysis; of these, BHLHB2, CCNL1, SE20-4, C8FW, PLK2, and SGK showed elevated expression in subjects with high concentrations of TZCA. Conclusion The identification of gene marker candidates in vitro using microarray analysis and their validation using human samples obtained from exposed subjects is a good tool for discovering genes of potential mechanistic interest and biomarkers of exposure. Thus, these genes are differentially expressed in response to FA and are potential effect biomarkers of FA exposure.

Li, Guang-Yong; Lee, Hye-Young; Shin, Ho-Sang; Kim, Hyeon-Young; Lim, Cheol-Hong; Lee, Byung-Hoon

2007-01-01

351

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

352

Benzene toxicokinetics in humans: exposure of bone marrow to metabolites.  

PubMed Central

A three compartment physiologically based toxicokinetic model was fitted to human data on benzene disposition. Two separate groups of model parameter derivations were obtained, depending on which data sets were being fitted. The model was then used to simulate five environmental or occupational exposures. Predicted values of the total bone marrow exposure to benzene and cumulative quantity of metabolites produced by the bone marrow were generated for each scenario. The relation between cumulative quantity of metabolites produced by the bone marrow and continuous benzene exposure was also investigated in detail for simulated inhalation exposure concentrations ranging from 0.0039 ppm to 150 ppm. At the level of environmental exposures, no dose rate effect was found for either model. The occupational exposures led to only slight dose rate effects. A 32 ppm exposure for 15 minutes predicted consistently higher values than a 1 ppm exposure for eight hours for the total exposure of bone marrow to benzene and the cumulative quantity of metabolites produced by the bone marrow. The general relation between the cumulative quantity of metabolites produced by the bone marrow and the inhalation concentration of benzene is not linear. An inflection point exists in some cases leading to a slightly S shaped curve. At environmental levels (0.0039-10 ppm) the curve bends upward, and it saturates at high experimental exposures (greater than 100 ppm).

Watanabe, K H; Bois, F Y; Daisey, J M; Auslander, D M; Spear, R C

1994-01-01

353

Radio frequency radiation (RFR): the nature of exposure and carcinogenic potential.  

PubMed

Epidemiologic evidence on the relation between radio-frequency radiation (RFR) and cancer is reviewed. Radio-wave communications are used extensively in modern society; thus, we are all subject to RFR created by radio, television, wireless telephony, emergency communications, radar, etc. Interest in the health effects of RFR has been motivated by the rapid growth in wireless communications and by media reports expressing concern that specific diseases may be caused by RFR exposure, e.g., from cellular telephone handsets. Due to the ubiquitous presence of RFR, the public health implication of any connection between RFR and cancer risk is potentially significant. (It is important to keep RFR distinct from power-line electromagnetic fields.) Comparison of potential risks from RFR exposure with other occupational and environmental health risks requires evaluating the level of support from available epidemiology, from studies with laboratory animals, and from mechanistic or biophysical information about the interaction of RFR with living tissues. A large number of studies have been done with laboratory animals and with in vitro systems; a more limited set of epidemiologic studies is available. Effects from RFR exposure that lead to temperature increases have been consistently reported, but 'non-thermal' effects have not been substantiated. Also, there are no mechanistic theories that support 'non-thermal' interactions with biology. Evidence to support a causal relationship between exposure to RFR and human cancers is scant. Our present state of knowledge about exposure, mechanisms, epidemiology, and animal studies does not identify significant cancer risks. PMID:9498896

Valberg, P A

1997-05-01

354

Sensitivity of cerebellar glutathione system to neonatal ionizing radiation exposure.  

PubMed

Reactive oxygen species (ROS) are relevant components of living organisms that, besides their role in the regulation of different important physiological functions, when present in excess are capable to affect cell oxidative status, leading to damage of cellular molecules and disturbance of normal cell function. ROS accumulation has been associated with a variety of conditions such as neurodegenerative diseases and ionizing radiation exposure. Cell ability to counteract ROS overproduction depends on the capacity of the endogenous antioxidant defenses--which includes the glutathione (GSH) system--to cope with. Since developing central nervous system (CNS) is especially sensitive to ROS-induced damage, the aim of the present work was to evaluate ROS, reduced GSH and oxidized glutathione (GSSG) levels in the cerebellum at different developmental ages after irradiation, in order to test if any changes were induced on these key oxidative stress-related cellular markers that might explain the high cerebellar vulnerability to radiation-induced injury. Since intracellular levels of GSH are maintained by glutathione reductase (GSHr), this enzymatic activity was also evaluated. Newborn Wistar rats were irradiated in their cephalic ends and the different parameters were measured, from 1h to 90 days post-irradiation. Results showed that an early transient increase in ROS levels followed by a decrease in cerebellar weight at 3-5 days post-irradiation were induced. An increase in cerebellar GSH levels was induced at 30 days after irradiation, together with a decrease in GSHr activity. These results support the hypothesis that ROS may represent a marker of damage prior to radiation-induced cell death. In contrast, it would be suggested that GSH system might play a role in the compensatory mechanisms triggered to counteract radiation-induced cerebellar damage. PMID:17267041

Di Toro, C G; Di Toro, P A; Zieher, L M; Guelman, L R

2007-05-01

355

Human exposure to bisphenol A by biomonitoring: Methods, results and assessment of environmental exposures  

SciTech Connect

Human exposure to bisphenol A is controversially discussed. This review critically assesses methods for biomonitoring of bisphenol A exposures and reported concentrations of bisphenol A in blood and urine of non-occupationally ('environmentally') exposed humans. From the many methods published to assess bisphenol A concentrations in biological media, mass spectrometry-based methods are considered most appropriate due to high sensitivity, selectivity and precision. In human blood, based on the known toxicokinetics of bisphenol A in humans, the expected very low concentrations of bisphenol A due to rapid biotransformation and the very rapid excretion result in severe limitations in the use of reported blood levels of bisphenol A for exposure assessment. Due to the rapid and complete excretion of orally administered bisphenol A, urine samples are considered as the appropriate body fluid for bisphenol A exposure assessment. In urine samples from several cohorts, bisphenol A (as glucuronide) was present in average concentrations in the range of 1-3 {mu}g/L suggesting that daily human exposure to bisphenol A is below 6 {mu}g per person (< 0.1 {mu}g/kg bw/day) for the majority of the population.

Dekant, Wolfgang [Department of Toxicology, University of Wuerzburg (Germany)], E-mail: dekant@toxi.uni-wuerzburg.de; Voelkel, Wolfgang [Bavarian Health and Food Safety Authority, Environmental Medicine/Biomonitoring, Munich (Germany)

2008-04-01

356

Lead exposures in the human environment. Final report  

SciTech Connect

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, and pinpointing the primary sources of lead in any particular environmental component is difficult. Nevertheless, our purpose is to describe the total exposure of humans to environmental lead and to determine the sources of lead contributing to this exposure. The total exposure is the total amount of lead consumed by ingestion and inhalation. Excluding lead exposure from choice or circumstance, a baseline level of potential human exposure can be defined for a normal individual eating a typical diet and living in a non-urban community remote from industrial sources of lead in a house without lead-based paints. Beyond this level, additive exposure factors can be determined for other environments (e.g. urban, occupational and smelter communities) and for certain habits and activities (e.g. pica, smoking, drinking and hobbies), with variation for age, sex or socioeconomic status.

Elias, R.W.

1985-01-01

357

Regulation of human skin pigmentation and responses to ultraviolet radiation.  

PubMed

Pigmentation of human skin is closely involved in protection against environmental stresses, in particular exposure to ultraviolet (UV) radiation. It is well known that darker skin is significantly more resistant to the damaging effects of UV, such as photocarcinogenesis and photoaging, than is lighter skin. Constitutive skin pigmentation depends on the amount of melanin and its distribution in that tissue. Melanin is significantly photoprotective and epidermal cells in darker skin incur less DNA damage than do those in lighter skin. This review summarizes current understanding of the regulation of constitutive human skin pigmentation and responses to UV radiation, with emphasis on physiological factors that influence those processes. Further research is needed to characterize the role of skin pigmentation to reduce photocarcinogenesis and to develop effective strategies to minimize such risks. PMID:17250543

Miyamura, Yoshinori; Coelho, Sergio G; Wolber, Rainer; Miller, Sharon A; Wakamatsu, Kazumasa; Zmudzka, Barbara Z; Ito, Shosuke; Smuda, Christoph; Passeron, Thierry; Choi, Wonseon; Batzer, Jan; Yamaguchi, Yuji; Beer, Janusz Z; Hearing, Vincent J

2007-02-01

358

Exposure to acute electromagnetic radiation of mobile phone exposure range alters transiently skin homeostasis of a model of pigmented reconstructed epidermis.  

PubMed

Exposure to electromagnetic radiations (EMR) produced by mobile phone concerns half the world's population and raises the problem of their impact on human health. In this study, we looked at the effects of mobile phone exposure (GSM basic, 900 MHz, SAR 2 mW g(-1) , 6 h) on a model of pigmented skin. We have analysed the expression and localization of various markers of keratinocyte and melanocyte differentiation 2, 6, 18 and 24 h after EMR exposure of reconstructed epidermis containing either only keratinocytes or a combination of keratinocytes and melanocytes grown on dead de-epidermized dermis, using histology, immunohistochemistry and Western blot. No changes were found in epidermal architecture, localization of epidermal markers, presence of apoptotic cells and the induction of p53 in both types of epidermis (with or without melanocytes) after exposure to EMR. In pigmented reconstructs, no change in the location and dendricity of melanocytes and in melanin transfer to neighbouring keratinocytes was detected after EMR exposure. Loricrin, cytokeratin 14 were significantly decreased at 6 h. The level of all markers increased at 24 h as compared to 6 h post-EMR exposure, associated with a significant decrease of the 20S proteasome activity. Our data indicate that exposure to 900 MHz frequency induces a transient alteration of epidermal homoeostasis, which may alter the protective capacity of the skin against external factors. Presence or absence of melanocytes did not modify the behaviour of reconstructs after EMR exposure. PMID:22938144

Simon, D; Daubos, A; Pain, C; Fitoussi, R; Vié, K; Taieb, A; de Benetti, L; Cario-André, M

2013-02-01

359

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.

360

Summary of Ionizing Radiation Analysis on the Long Duration Exposure Facility (Abstract Only).  

National Technical Information Service (NTIS)

The Ionizing Radiation Special Investigation Group (IRSIG) for the Long Duration Exposure Facility (LDEF) was established to perform radiation measurements and analysis not planned in the original experiments, and to assure availability of LDEF analysis r...

T. A. Parnell

1991-01-01

361

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...

362

Radiation carcinogenesis in man: influence of dose-response models and risk projection models in the estimation of risk coefficients following exposure to low-level radiation  

SciTech Connect

The somatic effects of concern in human populations exposed to low doses and low dose rates of ionizing radiations are those that may be induced by mutation in individual cells, singly or in small numbers. The most important of these is considered to be cancer induction. Current knowledge of the carcinogenic effect of radiation in man has been reviewed in two recent reports: the 1977 UNSCEAR Report; and the 1980 BEIR-III Report. Both reports emphasize that cancers of the breast, thyroid, hematopoietic tissues, lung, and bone can be induced by radiation. Other cancers, including the stomach, pancreas, pharynx, lymphatic, and perhaps all tissues of the body, may also be induced by radiation. Both reports calculate risk estimates in absolute and relative terms for low-dose, low-LET whole-body exposure, and for leukemia, breast cancer, thyroid cancer, lung cancer, and other cancers. These estimates derive from exposure and cancer incidence data at high doses and at high dose rates. There are no compelling scientific reasons to apply these values of risk to the very low doses and low dose rates of concern in human radiation protection. In the absence of reliable human data for calculating risk estimates, dose-response models have been constructed from extrapolations of animal data and high-dose-rate human data for projection of estimated risks at low doses and low dose rates. (ERB)

Fabrikant, J.I.

1982-02-01

363

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...

364

Human visual response to nuclear particle exposures  

NASA Technical Reports Server (NTRS)

Experiments with accelerated helium ions were performed in an effort to localize the site of initial radiation interactions in the eye that lead to light flash observations by astronauts during spaceflight. The character and efficiency of helium ion induction of visual sensations depended on the state of dark adaptation of the retina; also, the same events were seen with different efficiencies and details when particle flux density changed. It was concluded that fast particles cause interactions in the retina, particularly in the receptor layer, and thus give rise to the sensations of light flashes, streaks, and supernovae.

Tobias, C. A.; Budinger, T. F.; Lyman, J. T.

1972-01-01

365

Radiation Exposure in Nonvascular Fluoroscopy-Guided Interventional Procedures  

SciTech Connect

Purpose: To investigate the radiation exposure in non-vascular fluoroscopy guided interventions and to search strategies for dose reduction. Materials and Methods: Dose area product (DAP) of 638 consecutive non-vascular interventional procedures of one year were analyzed with respect to different types of interventions; gastrointestinal tract, biliary interventions, embolizations of tumors and hemorrhage. Data was analyzed with special focus on the fluoroscopy doses and frame doses. The third quartiles (Q3) of fluoroscopy dose values were defined in order to set a reference value for our in-hospital practice. Results: Mean fluoroscopy times of gastrostomy, jejunostomy, right and left sided percutaneous biliary drainage, chemoembolization of the liver and embolization due to various hemorrhages were 5.9, 8.6, 13.5, 16.6, 17.4 and 25.2 min, respectively. The respective Q3 total DAP were 52.9, 73.3, 155.1, 308.4, 428.6 and 529.3 Gy*cm{sup 2}. Overall, around 66% of the total DAP originated from the radiographic frames with only 34% of the total DAP applied by fluoroscopy (P < 0.001). The investigators experience had no significant impact on the total DAP applied, most likely since there was no stratification to intervention-complexity. Conclusion: To establish Diagnostic Reference Levels (DRLs), there is a need to establish a registry of radiation dose data for the most commonly performed procedures. Documentation of interventional procedures by fluoroscopy 'grabbing' has the potential to considerably reduce radiation dose applied and should be used instead of radiographic frames whenever possible.

Kloeckner, Roman, E-mail: kloeckner@radiologie.klinik.uni-mainz.de [Johannes Gutenberg-University, Department of Diagnostic and Interventional Radiology (Germany); Bersch, Anton [Kreuznacher Diakonie, Department of Trauma Surgery and Orthopedics (Germany); Santos, Daniel Pinto dos; Schneider, Jens; Dueber, Christoph; Pitton, Michael Bernhard [Johannes Gutenberg-University, Department of Diagnostic and Interventional Radiology (Germany)

2012-06-15

366

Radiation exposure benefit of a lead cap in invasive cardiology  

PubMed Central

Background: Occupational head exposure to radiation in cardiologists may cause radiation induced cataracts and an increased risk of brain cancer. Objective: To determine the effectiveness of 0.5 mm lead equivalent caps, not previously used in invasive cardiology, in comparison with a 1.0 mm lead equivalent ceiling mounted lead glass screen. Design: An anthropomorphic Alderson-Rando phantom was used to represent the patient. Scatter entrance skin air kerma to the operator position (S-ESAK-O) was measured during fluoroscopy for all standard angulations and the S-ESAK-O per dose–area product (DAP) calculated, as applied to the phantom. Results: Measured mean (SD) left/right anterior oblique angulation ratios of S-ESAK-O without lead devices were 23.1 (10.1), and varied as a function of tube angulation, body height, and angle of incidence. S-ESAK-O/DAP decreased with incremental operator body height by 10 (3)% per 10 cm. A 1.0 mm lead glass shield reduced mean S-ESAK-O/DAP originating from coronary angiography from 1089 (764) to 54 (29) nSv/Gy × cm2. A 0.5 mm lead cap was effective in lowering measured levels to 1.8 (1.1) nSv/Gy × cm2. Both devices together enabled attenuation to 0.5 (0.1) nSv/Gy × cm2. The most advantageous line of vision for protection of the operator’s eyes was ? 60° rightward. Conclusions: Use of 0.5 mm lead caps proved highly effective, attenuating S-ESAK-O to 2.7 (2.0) × 10?3 of baseline, and to 1.2 (1.4) × 10?3 of baseline where there was an additional 1.0 mm lead glass shield. These results could vary according to the x ray systems used, catheterisation protocols, and correct use of radiation protection devices.

Kuon, E; Birkel, J; Schmitt, M; Dahm, J B

2003-01-01

367

Assessing human exposure to airborne pollutants: Advances and opportunities  

SciTech Connect

A committee which was convened by the National Research Council, recently completed an analysis of new methods and technologies for assessing exposure to air pollutants. The committee identified three major ways of determining human exposure to airborne pollutants. Monitoring the air around an individual with a portable personal air sampler is, of course, the most comprehensive and most accurate. It is also the costliest and most time consuming. The second method is more indirect and involves techniques such as measuring the amount of a contaminant with a stationary monitor and extrapolating exposure by means of personal activity records or mathematical models. Exposure to carbon monoxide inside a car, for example, might be roughly calculated from the amount of time spent in the car and the quantity of carbon monoxide in the car under typical operating conditions. The third method involves biological markers as a measure of the integrated dose within the body and of past contact with pollutants. For example, a marker for airborne lead exposure can be elevated lead levels in the blood. However, this must be weighed against contributions from other media. A final and major point made in the report is the need to have accurate and realistic assessments to ensure optimal reduction of human exposure. To accomplish this, exposure assessment research should be supported by government programs. Although not stated, such research should also be supported by other sectors, including the regulated community.

Lioy, P.J. (Univ. of Medicine and Dentistry, Piscataway, NJ (United States))

1991-08-01

368

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

369

Expression of P53 protein after exposure to ionizing radiation  

NASA Astrophysics Data System (ADS)

One of the most important tumor suppressor genes is p53 gene, which is involved in apoptotic cell death, cell differentiation and cell cycle arrest. The expression of p53 gene can be evaluated by determining the presence of P53 protein in cells using Western Blot assay with a chemiluminescent method. This technique has shown variabilities that are due to biological factors. Film developing process can influence the quality of the p53 bands obtained. We irradiated tumor cell lines and human peripheral lymphocytes with 137Cs and 60Co gamma rays to standardize irradiation conditions, to compare ionizing radiation with actinomycin D and to reduce the observed variability of P53 protein induction levels. We found that increasing radiation doses increase P53 protein induction while it decreases viability. We also conclude that ionizing radiation could serve as a positive control for Western Blot analysis of protein P53. In addition, our results show that the developing process may play an important role in the quality of P53 protein bands and data interpretation. .

Salazar, A. M.; Salvador, C.; Ruiz-Trejo, C.; Ostrosky, P.; Brandan, M. E.

2001-10-01

370

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

371

AN OVERVIEW OF HUMAN EXPOSURE MODELING ACTIVITIES AT THE U.S. EPA'S NATIONAL EXPOSURE RESEARCH LABORATORY  

EPA Science Inventory

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

372

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.

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

2014-01-01

373

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

374

A trade study on radiation exposure for a crewed mission to the jovian moon callisto  

NASA Astrophysics Data System (ADS)

In support of the NASA Revolutionary Aerospace Systems Concepts (RASC) Human Outer Planet Exploration (HOPE) activity goal to investigate the technology required for future crewed missions to the outer solar system, a trade study for a mission to the Jovian moon Callisto was performed. Three different mission scenarios were developed, each with a different propulsion method, resulting in different mission durations. Nuclear thermal, nuclear electric, and fusion propulsion systems were considered. While the three mission scenarios were different in several ways including trajectory, spacecraft configuration, and whether or not an initial vessel was used to deliver supplies, each scenario included a crewed trip to Callisto beginning in late 2044 or early 2045 and a short surface stay, 29 to 120 days. For each scenario, the crew radiation exposure was evaluated. The radiation analysis for this trade study is described here. The effects of trip duration on the exposure levels are discussed as well as the advantages of avoiding solar minimum, i.e. the time in the solar cycle when the solar wind is at its minimum and interplanetary galactic cosmic ray (GCR) radiation is at its maximum. The benefits of choosing shielding material containing hydrogen and the possibility of using the hydrogen fuel tanks to shield the crew quarters are also discussed.

Nealy, J. E.; Clowdsley, M. S.; Wilson, J. W.; de Angelis, G.; Anderson, B. M.; Krizan, S. A.; Troutman, P. A.; Stillwagon, F. H.; Adams, R. B.; Borowski, S. K.

375

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

376

Monitoring human exposure to urban air pollutants  

SciTech Connect

A multidisciplinary study on a general population exposed to vehicle exhaust was undertaken in Pisa in 1991. Environmental factors such as air pollution and those associated with lifestyle were studied. Meanwhile, biological and medical indicators of health condition were investigated. Chromosomal aberrations, sister chromatid exchanges (SCEs), and micronuclei in lymphocytes were included for the assessment of the genotoxic risk. Because of the large number (3800) of subjects being investigated, standardization of protocols was compulsory. The results on data reproducibility are reported. To assess the reliability of the protocol on a large scale, the population of Porto Tolle, a village located in northeast Italy, was studied and compared to a subset of the Pisa population. Preliminary results showed that probable differences between the two populations and individuals were present in terms of SCE frequencies. The study was potentially able to detect the effects of several factors such as age, smoking, genetics, and environment. The in vitro treatment of lymphocytes with diepoxybutane confirmed the presence of more responsive individuals and permitted us to investigate the genetic predisposition to genetic damage. The possible influence of environmental factors was studied by correlation analyses with external exposure to air pollutants as well as with several lifestyle factors. 10 refs., 5 figs., 1 tab.

Barale, R.; Barrai, I.; Marrazzini, A. [Universita de Ferrara (Italy)] [and others

1993-10-01

377

Monitoring human exposure to urban air pollutants  

PubMed Central

A multidisciplinary study on a general population exposed to vehicle exhaust was undertaken in Pisa in 1991. Environmental factors such as air pollution and those associated with lifestyle were studied. Meanwhile, biological and medical indicators of health condition were investigated. Chromosomal aberrations, sister chromatid exchanges (SCEs), and micronuclei in lymphocytes were included for the assessment of the genotoxic risk. Because of the large number (3800) of subjects being investigated, standardization of protocols was compulsory. The results on data reproducibility are reported. To assess the reliability of the protocol on a large scale, the population of Porto Tolle, a village located in northeast Italy, was studied and compared to a subset of the Pisa population. Preliminary results showed that probable differences between the two populations and invididuals were present in terms of SCE frequencies. The study was potentially able to detect the effects of several factors such as age, smoking, genetics, and environment. The in vitro treatment of lymphocytes with diepoxybutane confirmed the presence of more responsive individuals and permitted us to investigate the genetic predisposition to genetic damage. The possible influence of environmental factors was studied by correlation analyses with external exposure to air pollutants as well as with several lifestyle factors.

Barale, R.; Barrai, I.; Sbrana, I.; Migliore, L.; Marrazzini, A.; Scarcelli, V.; Bacci, E.; Di Sibio, A.; Tessa, A.; Cocchi, L.; Lubrano, V.; Vassalle, C.; He, J.

1993-01-01

378

Radiation exposure as a possible etiologic factor in hairy cell leukemia (leukemic reticuloendotheliosis)  

Microsoft Academic Search

The frequency of prior occupational, accidental, or therapeutic radiation exposure was significantly higher for hairy cell leukemia patients than for a control group of solid tumor patients. Hairy cell leukemia patients were also more frequently involved in occupations at high risk of radiation exposure such as chemist, engineer, physicist, and health care facility worker. The observation that the incidence of

David J. Stewart; Michael J. Keating

1980-01-01

379

Monitoring exposure to atomic bomb radiation by somatic mutation.  

PubMed Central

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.

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

1996-01-01

380

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

381

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...

382

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

383

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.

384

Further studies of 60 Hz exposure effects on human function  

SciTech Connect

Public concern has been expressed about possible health risks arising from exposure to the electric and magnetic fields generated power distribution systems. This project is addressing this concern through a laboratory research program designed to evaluate the effects of brief exposure to known field conditions on multiple measures of human function. In previous research, we found that exposure had statistically significant effects on physiological measures of cardiac and brain activity, and on performance measures of reaction time and performance accuracy. Effects were seen more clearly under intermittent exposure conditions, and at certain levels of electric and magnetic field strength. In this continuation effort, we are performing a series of exploratory studies, to be followed by a confirmatory experiment, to determine if the above physiological effects differ as a function of exposure to the electric and magnetic fields separately and combined, time of day, and rate of intermittent exposure. Further studies will explore the mechanisms underlying these effects. The information developed in this project will be of value in risk assessment activities, and in basic research aimed at identifying specific factors involved in the interaction of power line fields with the human system. In this reporting period our goals were to: (a) continue performance of the probe studies; (b) participate in a site visit at MRI; (c) request 1991 research continuation funding; and (d) submit an abstract of project findings for presentation at the 1990 DOE Contractors Review Meeting.

Graham, C.; Cohen, H.D.

1990-10-09

385

Further studies of 60 Hz exposure effects on human function  

SciTech Connect

Public concern has been expressed about possible health risks arising from exposure to the electric and magnetic fields generated by power distribution systems. This project is addressing this concern through a laboratory research program designed to evaluate the effects of brief exposure to known field conditions on multiple measures of human function. In this continuation effort, a series of exploratory studies are being performed, which will be followed by a confirmatory experiment, to determine if the above physiological effects differ as a function of exposure to the electric and magnetic fields separately and combined, time of day, and rate of intermittent exposure. Project status to date is as follows. Funds were awarded in the last reporting period to continue this research activity at a reduced level until December 31, 1990. An initial series of exploratory studies, involving 24 healthy male volunteers exposed over multiple sessions, has been completed. These studies assessed whether effects on human physiology differ over the day as a function of intermittent exposure to the electric versus the magnetic fields. Exposure to the magnetic fields produced a pattern of cardiac changes similar to that observed in our previous research. This pattern was not found when subjects were exposed to the electric field. During this reporting period our goals were to: continue performance of the probe'' studies; and present project findings at the 1990 meeting of the Bioelectromagnetics Society (BEMS).

Graham, C.

1990-07-20

386

TEMPERATURE REGULATION IN THE UNRESTRAINED RABBIT DURING EXPOSURE TO 600 MHZ RADIOFREQUENCY RADIATION  

EPA Science Inventory

Six male New Zealand white rabbits were individually exposed to 600 MHz radiofrequency (RF) radiation for 90 min in a waveguide exposure system at an ambient temperature (Ta) of 20 or 30 C. Immediately after exposure, the rabbit was removed from the exposure chamber and its colon...

387

Domoic acid and human exposure risks: a review.  

PubMed

Domoic acid is a potent neurotoxin that is naturally produced by several diatom species of the genus Pseudo-nitzschia. The toxin acts as a glutamate agonist and is excitotoxic in the vertebrate central nervous system and other glutamate receptor-rich organs. Human exposure to domoic acid occurs via the consumption of contaminated shellfish that have accumulated the toxin while filter feeding on toxigenic phytoplankton during blooms. The first reported human domoic acid poisoning event occurred in Canada in 1987 during which clinical signs of acute toxicity such as gastrointestinal distress, confusion, disorientation, memory loss, coma and death were observed. The illness was named amnesic shellfish poisoning (ASP) and due to effective seafood monitoring programs there have been no documented ASP cases since 1987. However, domoic acid poisoning has a significant effect on marine wildlife and multiple poisoning events have occurred in marine birds and mammals over the last few decades. Currently, domoic acid producing diatom blooms are thought to be increasing in frequency world wide, posing an increasing threat to wildlife and human health. Of particular concern are the potential impacts of long-term low-level exposure in "at risk" human populations. The impacts of repetitive low-level domoic acid exposure are currently unknown. This review provides a basic description of the mechanism of action of domoic acid as well as a synthesis of information pertaining to domoic acid exposure routes, toxin susceptibility, and the importance of effective monitoring programs. The importance of investigating the potential human health impacts of long-term low-level domoic acid exposure in "at risk" human populations is also discussed. PMID:19505488

Lefebvre, Kathi A; Robertson, Alison

2010-08-15

388

Polonium in cigarette smoke and radiation exposure of lungs  

NASA Astrophysics Data System (ADS)

Polonium (210Po), the most volatile of naturally-occurring radionuclides in plants, was analysed in three common brands of cigarettes produced in Portugal. The analyses were carried out on the unburned tobacco contained in cigarettes, on the ashes and butts of smoked cigarettes and on the mainstream smoke. 210Po in tobacco displays concentrations ranging from 3 to 37 mBq g-1, depending upon the cigarette brand. The 210Po activity remaining in the solid residue of a smoked cigarette varied from 0.3 to 4.9 mBq per cigarette, and the 210Po in the inhaled smoke varied from 2.6 to 28.9 mBq. In all brands of cigarettes tested, a large fraction of the 210Po content is not inhaled by the smoker and it is released into the atmosphere. Part of it may be inhaled by passive smokers. Depending upon the commercial brand and upon the presence or absence of a filter in the cigarette, 5 to 37 % of the 210Po in the cigarette can be inhaled by the smoker. Taking into account the average 210Po in surface air, the smoker of one pack of twenty cigarettes per day may inhale 50 times 210Po than a non smoker. Cigarette smoke contributes with 1.5 % to the daily rate of 210Po absorption into the blood, 0.39 Bq d-1, and, after systemic circulation it gives rise to a whole body radiation dose in the same proportion. However, in the smoker the deposition of 210Po in the lungs is much more elevated than normal and may originate an enhanced radiation exposure. Estimated dose to the lungs is presented and radiobiological effects of cigarette smoke are discussed.

Carvalho, Fernando P.; Oliveira, João M.

2006-01-01

389

Radiation risk and human space exploration.  

PubMed

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. PMID:12577903

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

2003-01-01

390

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

391

Assessment of human exposure level to PM10 in China  

NASA Astrophysics Data System (ADS)

Epidemiological studies have found that atmospheric particulate matter, especially PM10 (inhalable particulate matter with aerodynamic diameter less than or equal to 10 ?m) is one of the pollutants that are harmful to human health. In recent years, particulate matter pollution in China is becoming increasingly serious and PM10 has become the primary pollutant in Beijing and other cities. Therefore, it is necessary to carry out studies and a health damage assessment of PM10. In human health damage assessment, measuring human exposure level to PM10 is required and crucial to provide accurate exposure data for the exposure-response relationship, and also for the accurate quantitative assessment of human exposure. The spatial distribution of particle concentration in China is variable because of spatial differences in the local economic level and the geographical environment. Along with the accelerating urbanisation in China, city population density is high, and the population distribution is variable between and within cities, thus resulting in different population numbers exposed to different concentration ranges. Therefore, an accurate assessment of China's level of exposure to particulate matter is a priority and the basis for assessing the damage to public health caused by particle pollution. Using high accuracy population and PM10 monitoring data, this study analysed the human exposure to PM10 in different regions and typical cities of China. The results show that for most areas of China, the population-weighted PM10 exposure concentration is slightly higher than the annual mean concentration, meaning that more of the population is exposed to high concentrations, and most of the population is exposed to levels that meet the second national standard (between 40 and 100 ?g m-3), occupying about 83.7% of population and 76.3% of area in China. The population exposure to PM10 is higher in two types of typical regions and cities: areas with dense human populations such as Jingjinji, Beijing and Tianjin, and areas with more sand dust and factories such as Northwest and Chongqing.

An, Xingqin; Hou, Qing; Li, Nan; Zhai, Shixian

2013-05-01

392

Numerical modeling of heat and mass transfer in the human eye under millimeter wave exposure.  

PubMed

Human exposure to millimeter wave (MMW) radiation is expected to increase in the next several years. In this work, we present a thermal model of the human eye under MMW illumination. The model takes into account the fluid dynamics of the aqueous humor and predicts a frequency-dependent reversal of its flow that also depends on the incident power density. The calculated maximum fluid velocity in the anterior chamber and the temperature rise at the corneal apex are reported for frequencies from 40 to 100?GHz and different values of incident power density. PMID:23315965

Karampatzakis, Andreas; Samaras, Theodoros

2013-05-01

393

ASSESSING CHILDREN'S EXPOSURES TO PESTICIDES: AN IMPORTANT APPLICATION OF THE STOCHASTIC HUMAN EXPOSURE AND DOSE SIMULATION MODEL (SHEDS)  

EPA Science Inventory

Accurately quantifying human exposures and doses of various populations to environmental pollutants is critical for the Agency to assess and manage human health risks. For example, the Food Quality Protection Act of 1996 (FQPA) requires EPA to consider aggregate human exposure ...

394

Geant4-based radiation hazard assessment for human exploration missions  

NASA Astrophysics Data System (ADS)

Most of the radiation effects assessment methods on human crews are constrained to the Low Earth Orbit environment However the forthcoming Solar System exploration missions will encounter a totally different radiation environment as there is no shielding provided by the geomagnetic field In this work we present the first results on the simulation of geomagnetically unshielded Solar Energetic Particles SEP events and Galactic Cosmic Rays GCR impinging on a very simple spacecraft geometry We have used MULASSIS Multi-Layered Shielding Simulation Software a Monte Carlo code based on Geant4 developed for the European Space Agency Geant4 is a high energy physics toolkit originally developed at CERN to simulate particle interactions in high energy accelerators recently applied to space radiation protection studies Our setup consists of two semi-infinite parallel slabs the spacecraft shield and a 30 cm water phantom representing a human body Simulations have been carried out for different shielding materials and thicknesses assessing the dose and dose equivalent received by the phantom for different radiation sources SEP events have been simulated using an evolution of the JPL-91 model for worst-case conditions in solar maximum and some selected extreme events Our results show that a 20 g cm -2 shield of polyethylene is enough for having a dose below 10 mSv though the risk of exposure depends on the number of extreme events taking place throughout the duration of the mission GCR simulations are based on CREME96 fluences for

Bernabeu, J.; Casanova, I.

395

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...

396

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...

397

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...

398

The Effect of Controlled Ozone Exposure on Human Lumphocyte Function.  

National Technical Information Service (NTIS)

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 co...

M. L. Peterson R. Smialowicz S. Harder B. Ketcham D. House

1982-01-01

399

ORD BEST PRACTICES FOR OBSERVATIONAL HUMAN EXPOSURE MEASUREMENT STUDIES  

EPA Science Inventory

This abstract describes a presentation for the 2007 Society of Toxicology Annual Meeting in Charlotte, NC on March 27, 2007. It will be included in a special Issues Session titled "Scientific and Ethical Considerations in Human Exposure Studies." The presentation desc...

400

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...

401

Exposure to Inorganic Arsenic Metabolites during Early Human Development  

Microsoft Academic Search

Because of the lack of data on the exposure to and toxic effects of inorganic arsenic during early human development, the transfer of arsenic to the fetus and suckling infant was studied in a native Andean population, living in the village San Antonio de los Cobres in the North west of Argentina, where the drinking water contains about 200 ?g\\/liter.

Gabriela Concha; Gerardo Vogler; Dora Lezcano; Barbro Nermell; Marie Vahter

1998-01-01

402

DISPOSITION OF BROMODICHLOROMETHANE IN HUMANS FOLLOWING ORAL AND DERMAL EXPOSURE  

EPA Science Inventory

DISPOSITION OF BROMODICHLOROMETHANE IN HUMANS FOLLOWING ORAL AND DERMAL EXPOSURE. TL Leavens1, MW Case1, RA Pegram1, BC Blount2, DM DeMarini1, MC Madden1, and JL Valentine3. 1NHEERL, USEPA, RTP, NC, USA; 2CDC, Atlanta, GA, USA; 3RTI, RTP, NC, USA. The disinfection byproduct ...

403

A Dermatotoxicokinetic Model of Human Exposures to Jet Fuel  

Microsoft Academic Search

Workers, both in the military and the commercial airline industry, are exposed to jet fuel by inhalation and dermal contact. We present a dermatotoxicokinetic (DTK) model that quantifies the absorption, distribution, and elimination of aromatic and aliphatic components of jet fuel following dermal exposures in humans. Kinetic data were obtained from 10 healthy volunteers following a single dose of JP-8

David Kim; Melvin E. Andersen; Leena A. Nylander-French

2006-01-01

404

Intrauterine Exposure of Humans to PCBs (Polychlorinated Biphenyls): Newborn Effects.  

National Technical Information Service (NTIS)

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 ...

G. Fein J. L. Jacobson S. W. Jacobson P. Schwarz

1984-01-01

405

Chromosome neighborhood composition determines translocation outcomes after exposure to high-dose radiation in primary cells  

Microsoft Academic Search

Radiation exposure is an occupational hazard for military personnel, some health care professionals, airport security screeners,\\u000a and medical patients, with some individuals at risk for acute, high-dose exposures. Therefore, the biological effects of radiation,\\u000a especially the potential for chromosome damage, are major occupational and health concerns. However, the biophysical mechanisms\\u000a of chromosome instability subsequent to radiation-induced DNA damage are poorly

Lura Brianna Caddle; Jeremy L. Grant; Jin Szatkiewicz; Johann van Hase; Bobbi-Jo Shirley; Joerg Bewersdorf; Christoph Cremer; Alain Arneodo; Andre Khalil; Kevin D. Mills

2007-01-01

406

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.

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

2014-01-01

407

Survival enhancement and hemopoietic regeneration following radiation exposure: therapeutic approach using glucan and granulocyte colony-stimulating factor  

SciTech Connect

C3H/HeN female mice were exposed to whole-body cobalt-60 radiation and administered soluble glucan (5 mg i.v. at 1 h following exposure), recombinant human granulocyte colony-stimulating factor or both agents. Treatments were evaluated for their ability to enhance hemopoietic regeneration, and to increase survival after radiation-induced myelosuppression. Both glucan and G-CSF enhanced hemopoietic regeneration alone; however, greater effects were observed in mice receiving both agents. For example, on day 17 following a sublethal 6.5-Gy radiation exposure, mice treated with saline, G-CSF, glucan, or both agents, respectively, exhibited 36%, 65%, 50%, and 78% of normal bone marrow cellularity, and 84%, 175%, 152%, and 212% of normal splenic cellularity.

Patchen, M.L.; MacVittie, T.J.; Solberg, B.D.; Souza, L.M.

1990-01-01