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1

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

2

A Translatable Predictor of Human Radiation Exposure  

PubMed Central

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

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

2014-01-01

3

A translatable predictor of human radiation exposure.  

PubMed

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

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

2014-01-01

4

Radiation exposure for human Mars exploration  

NASA Technical Reports Server (NTRS)

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.

Simonsen, L. C.; Wilson, J. W.; Kim, M. H.; Cucinotta, F. A.; Dicello, J. F. (Principal Investigator)

2000-01-01

5

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

6

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

7

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

SciTech Connect

The current knowledge of the carcinogenic effect of radiation in man is considered. The discussion is restricted to dose-incidence data in humans, particularly to certain of those epidemiological studies of human populations that are used most frequently for risk estimation for low-dose radiation carcinogenesis in man. Emphasis is placed solely on those surveys concerned with nuclear explosions and medical exposures. (ACR)

Fabrikant, J.I.

1981-05-01

8

Radiation exposure to human trachea from Xenon-133 procedures  

SciTech Connect

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

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

1995-08-01

9

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

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

10

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

11

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

12

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. PMID:23144912

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

13

Radiation Contamination Versus Exposure  

MedlinePLUS

RADIATION CONTAMINATION VERSUS EXPOSURE EXTERNAL CONTAMINATION External contamination occurs when radioactive material comes into contact with a ... radioactive materials can accumulate in different body organs. RADIATION EXPOSURE Another word for radiation exposure is irradiation. ...

14

Radiation Exposure  

MedlinePLUS

... particles. It occurs naturally in sunlight. Man-made radiation is used in X-rays, nuclear weapons, nuclear power plants and cancer treatment. If you are exposed to small amounts of radiation over a long time, it raises your risk ...

15

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

PubMed Central

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

Fabrikant, J. I.

1981-01-01

16

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

17

Early and Late Damages in Chromosome 3 of Human Lymphocytes After Radiation Exposure  

NASA Technical Reports Server (NTRS)

Tumor formation in humans or animals is a multi-step process. An early stage of cancer development is believed to be genomic instability (GI) which accelerates the mutation rate in the descendants of the cells surviving radiation exposure. GI is defined as elevated or persistent genetic damages occurring many generations after the cells are exposed. While early studies have demonstrated radiation-induced GI in several cell types as detected in endpoints such as mutation, apoptosis and damages in chromosomes, the dependence of GI on the quality of radiation remains uncertain. To investigate GI in human lymphocytes induced by both low- and high-LET radiation, we initially exposed white blood cells collected from healthy subjects to gamma rays in vitro, and cultured the cells for multiple generations. Chromosome aberrations were analyzed in cells collected at first mitosis post irradiation and at several intervals during the culture period. Among a number of biological endpoints planned for the project, the multi-color banding fluorescent in situ hybridization (mBAND) allows identification of inversions that were expected to be stable. We present here early and late chromosome aberrations detected with mBAND in chromosome 3 after gamma exposure. Comparison of chromosome damages in between human lymphocytes and human epithelial cells is also discussed

Sunagawa, Mayumi; Mangala, Lingegowda; Zhang, Ye; Kahdim, Munira; Wilson, Bobby; Cucinotta, Francis A.; Wu, Honglu

2011-01-01

18

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

19

Human exposure to ultraviolet radiation at the Antipodes - a comparison between an Antarctic (67°S) and Arctic (75°N) location  

Microsoft Academic Search

. We used ultraviolet radiation dosimeters to investigate human exposure at two polar latitudes with a 24-h photoperiod: at Rothera Station (UK) (67°S) and at a field camp in the Haughton impact structure in the Canadian High Arctic (75°N). Mean personal UV radiation exposure in the Antarctic location was 4.3 times greater than that in the Arctic location, even in

Charles Cockell; Gerda Horneck; Petra Rettberg; Jo Arendt; Kerstin Scherer; Rainer Facius; Anton Gugg-Helminger

2002-01-01

20

Dangers of Radiation Exposure  

NSDL National Science Digital Library

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

American Association for the Advancement of Science (AAAS;)

2005-03-15

21

Widespread decreased expression of immune function genes in human peripheral blood following radiation exposure.  

PubMed

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

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

2013-12-01

22

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

23

Biological effects of alpha particle radiation exposure on human monocytic cells.  

PubMed

Radon ((222)Rn) gas produces decay progeny that emits high energy alpha (?)-particles. Epidemiological studies have shown that exposure to (222)Rn is linked with elevated risk of developing lung cancer, however clear mechanisms leading to such effects have not been delineated. Cytokines play a critical role in inflammation and their dysregulated production often contributes to disease pathogenesis. In this study, Bio-plex multiplex technology was employed to investigate modulations of 27 pro-inflammatory cytokines following exposure of human monocytic cells to 1.5 Gy of ?-particle radiation. Concurrently, DNA damage was assessed by examining the formation of phosphorylated H2A histone family X (?-H2AX) sites. Of the 27 cytokines assessed, 4 cytokines were shown to be statistically downregulated by ?2 fold relative to the untreated controls and included the interleukin (IL) family of proteins (IL-2, IL-15 and IL-17) and macrophage inflammatory protein 1 beta (MIP-1b). Interferon-inducible protein-12 (IP-12), vascular endothelial growth factor and regulated on activation normal T cell expressed and secreted (RANTES) were shown to be high expressors and upregulated. Cells irradiated with ?-particles ranging from 0.27 to 2.14 Gy showed statistically significant, dose-dependant increases in ?-H2AX formation. These data suggest that ?-particle radiation causes dysregulation in the production of a number of pro-inflammatory cytokines and results in significant DNA damage. PMID:22153871

Chauhan, Vinita; Howland, Matthew; Kutzner, Barbara; McNamee, James P; Bellier, Pascale V; Wilkins, Ruth C

2012-04-01

24

Nuclear Energy: Radiation Exposure  

NSDL National Science Digital Library

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

Pratte, John

25

Evidence for Radiation Hormesis After In Vitro Exposure of Human Lymphocytes to Low Doses of Ionizing Radiation§  

PubMed Central

Previous research has demonstrated that adding a very small gamma-ray dose to a small alpha radiation dose can completely suppress lung cancer induction by alpha radiation (a gamma-ray hormetic effect). Here we investigated the possibility of gamma-ray hormesis during low-dose neutron irradiation, since a small contribution to the total radiation dose from neutrons involves gamma rays. Using binucleated cells with micronuclei (micronucleated cells) among in vitro monoenergetic-neutron-irradiated human lymphocytes as a measure of residual damage, we investigated the influence of the small gamma-ray contribution to the dose on suppressing residual damage. We used residual damage data from previous experiments that involved neutrons with five different energies (0.22-, 0.44-, 1.5-, 5.9-, and 13.7-million electron volts [MeV]). Corresponding gamma-ray contributions to the dose were approximately 1%, 1%, 2%, 6%, and 6%, respectively. Total absorbed radiation doses were 0, 10, 50, and 100 mGy for each neutron source. We demonstrate for the first time a protective effect (reduced residual damage) of the small gamma-ray contribution to the neutron dose. Using similar data for exposure to gamma rays only, we also demonstrate a protective effect of 10 mGy (but not 50 or 100 mGy) related to reducing the frequency of micronucleated cells to below the spontaneous level. PMID:18846261

Rithidech, Kanokporn Noy; Scott, Bobby R.

2008-01-01

26

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.

27

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

28

Radiation doses due to human exposure to cosmic radiation in the Republic of Croatia.  

PubMed

The annual per caput whole body equivalent dose for the world's population on ground level in areas on normal background from natural sources of radiation is approximately 2.4 mSv, 0.3 mSv of which is due to cosmic rays. As the intensity of cosmic radiation increases with altitude, the subpopulation of aircraft flight crews and frequent flyers may receive an additional equivalent dose of up to 1 mSv during commercial flights. The estimated annual collective equivalent dose from aircraft flights for the Republic of Croatia is about 4 man Sv, whereas the annual collective effective dose due to the cosmic radiation component of normal background radiation is approximately 1200 man Sv. Future development of hypersonic aircraft, which would fly orbital trajectories above the Earth's atmosphere would cause a significant increase of doses. Also, future utilization of extended space missions might be limited by high equivalent doses to space travellers. PMID:7763185

Frani?, Z

1994-09-01

29

Radiation exposure and pregnancy.  

PubMed

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

Labant, Amy; Silva, Christina

2014-01-01

30

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

31

Americans' Average Radiation Exposure  

SciTech Connect

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

NA

2000-08-11

32

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

33

Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights  

NASA Astrophysics Data System (ADS)

NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far, the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space, exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation methods — shielding and anti-carcinogens.

Denkins, Pamela; Badhwar, Gautam; Obot, Victor; Wilson, Bobby; Jejelewo, Olufisayo

2001-08-01

34

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.

35

Pregnancy and Radiation Exposure  

MedlinePLUS

... Exposure to the Embryo or Fetus from Diagnostic Nuclear Medicine Pregnant women may be administered radioactive materials ... determination be obtained from the health physicist, a nuclear medicine physician, or a radiation oncologist associated with ...

36

Carotenoid Supplementation Reduces Erythema in Human Skin After Simulated Solar Radiation Exposure (44476)  

Microsoft Academic Search

Excessive exposure to solar radiation, especially ultraviolet A (UVA: 320- 400 nm) and ultraviolet B (UVB: 290-320 nm) radiation, may induce UV-carcinogenesis and erythema in the skin. Although the protective effects of carotenoids against skin lesions are still unclear, b-carotene has been proposed as an oral sun protectant. The purpose of this study was to determine the magnitude of the

JEONGMIN LEE; S HUGUANG JIANG; N ORMAN LEVINE; RONALD R. WATSON

37

Are chromosomal instabilities induced by exposure of cultured normal human cells to low- or high-LET radiation?  

NASA Technical Reports Server (NTRS)

Radiation-induced genomic instability has been proposed as a very early, if not an initiating, step in radiation carcinogenesis. Numerous studies have established the occurrence of radiation-induced chromosomal instability in various cells of both human and rodent origin. In many of these studies, however, the cells were not "normal" initially, and in many cases they involved tumor-derived cell lines. The phenomenon clearly would be of even greater interest if it were shown to occur generally in cells that are normal at the outset, rather than cells that may have been "selected" because of a pre-existing susceptibility to induced instability. As a test of the generality of the phenomenon, we studied low-passage normal diploid human fibroblasts (AG1521A) to determine whether they are susceptible to the induction of chromosomal instability in the progeny of surviving cells after exposure in G(0) to low- and high-LET radiation. Cytogenetic assays for instability were performed on both mixed populations of cells and clones of cells surviving exposure. We found no evidence for the induction of such instability as a result of radiation exposure, though we observed a senescence-related chromosomal instability in the progeny of both irradiated and unirradiated cell populations. Copyright 2003 by Radiation Research Society.

Dugan, Lawrence C.; Bedford, Joel S.

2003-01-01

38

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

Microsoft Academic Search

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

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

2009-01-01

39

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

40

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

41

HUMAN EXPOSURE ACTIVITY PATTERNS  

EPA Science Inventory

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

42

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

NASA Technical Reports Server (NTRS)

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

Denkins, Pamela; Badhwar, Gautam; Obot, Victor

2000-01-01

43

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

SciTech Connect

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

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

1986-01-01

44

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

PubMed Central

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

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

2011-01-01

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. PMID:24398983

Sokolov, Mykyta; Neumann, Ronald

2014-01-01

46

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

PubMed

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

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

1995-05-01

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. PMID:8781398

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

Chromosomal aberrations in human lymphocytes and fibroblasts after exposure to very low doses of high-LET radiation  

PubMed Central

Purpose: The relationship between biological effects and low doses of radiation is still uncertain, especially for high-LET radiation exposures. Estimates of risk from exposure to low doses and low dose rates are often extrapolated from the Japanese atomic bomb survivor data using either linear or linear-quadratic models fitted to dose–response data. In this study, we determined the dose–response for chromosome damage after exposure to very low doses of high-LET radiation and assessed the radiation qualities of Fe, Si and Oxygen ions. Materials and methods: Chromosomal aberrations (CA) were measured in human peripheral blood lymphocytes and normal skin fibroblasts after exposure to very low doses (0.01–0.20 Gy) of 77-MeV/u oxygen (LET = 55 keV/µm), 170-MeV/u 28Si (LET = 99 keV/µm), or 56Fe ions with energies of 600- or 450-MeV/u (LET = 180 or 195 keV/µm). These exposures included doses that, on average, produce fewer than one in five direct ion traversals per cell nucleus. Chromosomes were analyzed using the whole-chromosome fluorescence in situ hybridization (FISH) technique during the first cell division after irradiation, and CA were identified as either simple exchanges (translocations and dicentrics) or complex exchanges (involving more than two breaks in two or more chromosomes). The frequencies of CA in the painted chromosome(s) were evaluated as the ratio between aberrations scored and total cells analyzed. The dose–response for simple exchanges was assessed using a generalized linear model assuming binomial errors per number of chromosomes scored. The model coefficients were extrapolated to whole-genome equivalents. The linear dose–response denoted as the targete effects (TE) model considered the mean number of radiation tracks per cell. Two different non-targeted effect (NTE) models, P = P0 + ?T + ? × I (NTE1), and P = P0 + ?T (1 ? e?T) + ?e?T × I (NTE2), were compared with the simple linear model, P = P0 + ?T. Akaike information criteria (AIC) and Bayes information criteria (BIC) were used to compare TE and NTE models for fitting chromosome aberrations in low dose range. Results: Doses that on average produce more than one ion traversal per cell nucleus showed a linear dose–response for CA in both lymphocytes and fibroblasts. However, for doses that produce fewer than one tracks per cell in fibroblasts, O, Si and Fe particles showed a dose-independent response for CA that was significantly elevated relative to background frequencies. For fibroblasts the NTE model 2, P = P0 + ?T (1 ? e?T) + ?e?T × I, showed improved fit to CA in low dose range compared with TE model or NTE1 model. For lymphocytes, tests of the various models were less clear with TE model optimal for Si and Fe while the NTE2 model optimal for O particles. When low-dose exposures were fractionated with 2-h intervals, increased frequencies of both simple and complex exchanges were observed. Nitric oxide scavenger reduced CA induced by low doses of high-LET irradiation. Inhibition of transforming growth factor-? receptor-1 reduced the frequency of simple exchanges. Conclusions: The results show a non-linear dose–response for CA in fibroblasts after very low doses of high-LET exposure. Possible explanations for this could involve non-targeted effects due to aberrant cell signaling [ 1], perhaps involving nitric oxide and TGF-?, or could be due to delta-ray dose fluctuations [ 2] where CA are induced in cells that receive a significant dose from delta-rays emanating from the multiple ion tracks that do not directly traverse cell nuclei.

Hada, Megumi; George, Kerry; Chappell, Lori; Cucinotta, Francis A.

2014-01-01

50

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

NASA Astrophysics Data System (ADS)

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

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

51

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

NASA Astrophysics Data System (ADS)

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

Zhang, Ye; Rohde, Larry; Wu, Honglu

52

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

53

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

54

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

55

Occupational Radiation Exposures  

Cancer.gov

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

56

Cardiovascular complications of radiation exposure.  

PubMed

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

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

2014-01-01

57

Radiation exposure in the moon environment  

NASA Astrophysics Data System (ADS)

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

Reitz, Guenther; Berger, Thomas; Matthiae, Daniel

2012-12-01

58

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

59

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. PMID:21124906

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

2010-01-01

60

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...

61

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

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

62

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

63

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

PubMed

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

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

2014-04-15

64

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...

65

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. PMID:23899786

Sokolov, Mykyta; Neumann, Ronald

2013-01-01

66

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

67

Genome Wide Evaluation of Normal Human Tissue in Response to Controlled, In vivo Low-Dose Low LET Ionizing Radiation Exposure: Pathways and Mechanisms Final Report, September 2013  

SciTech Connect

During course of this project, we have worked in several areas relevant to low-dose ionizing radiation. Using gene expression to measure biological response, we have examined the response of human skin exposed in-vivo to radation, human skin exposed ex-vivo to radiation, and a human-skin model exposed to radiation. We have learned a great deal about the biological response of human skin to low-dose ionizing radiation.

Rocke, David M. [University of California Davis

2013-09-09

68

Human exposure to bisphenol A.  

PubMed

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 environment, air and soil) can be one source of human BPA exposure, but the primary route of human exposure is foods. The daily human intake of BPA is <1 microg/kg body weight/day on the basis of several studies, and whether these doses can have an adverse endocrine disruptive effect on humans, especially fetuses, needs to be studied carefully. PMID:16860916

Kang, Jeong-Hun; Kondo, Fusao; Katayama, Yoshiki

2006-09-21

69

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

70

Modeling deterministic effects in hematopoietic system caused by chronic exposure to ionizing radiation in large human cohorts  

PubMed Central

A new model of the hematopoietic system for humans chronically exposed to ionizing radiation allows for quantitative description of the initial hematopoiesis inhibition and subsequent increase in the risks of late stochastic effects such as leukemia. This model describes the dynamics of the hematopoietic stem cell compartment as well as the dynamics of each of the three blood cell types (leukocytes, erythrocytes, and platelets). The model parameters are estimated from the results of other experiments. They include the steady-state numbers of hematopoietic stem cells and peripheral blood cell lines for an unexposed organism, amplification parameters for each blood cell line, parameters describing the proliferation and apoptosis, parameters of feedback functions regulating the steady-state numbers, and characteristics of radiosensitivity in respect to cell death and non-lethal cell damages. The dynamic model of hematopoiesis is applied to the data on subcohort of the Techa River residents with hematological measurements (e.g., blood counts) performed in 1950–1956 (which totals to about 3,500 exposed individuals). Among well-described effects observed in these data are the slope value of the dose-effect curves describing the hematopoietic inhibition and the dose rate patterns of the fractions of cytopenic states (e.g., leukopenia, thrombocytopenia). The model has been further generalized by inclusion of the component describing the risk of late stochastic effects. The risks of the development of late effects (such as leukemia) in population groups with specific patterns of early reactions in hematopoiesis (such as leukopenia induced by ionizing radiation) are investigated using simulation studies and compared to data. PMID:20699693

Akushevich, Igor V.; Veremeyeva, Galina A.; Dimov, Georgy P.; Ukraintseva, Svetlana V.; Arbeev, Konstantin G.; Akleyev, Alexander V.; Yashin, Anatoly I.

2013-01-01

71

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

72

Exposure of nondividing populations of primary human fibroblasts to UV (254 nm) radiation induces a transient enhancement in capacity to repair potentially lethal cellular damage  

SciTech Connect

Nondividing (arrested) populations of primary human fibroblasts from normal individuals exposed to an intial dose (1.5 or 3 Jm/sup -2/) of far-UV (254 nm) radiation and then incubated in medium containing low (0.5%) serum develop enhanced resistance to inactivation of cloning efficiency by a second (challenge) dose of UV. The resistance develops within 2-4 days, after which there is a decline. Resistance develops to a higher degree and more rapidly (1-2 days) in cells derived from patients with the variant form of xeroderma pigmentosum. Excision-deficient cells from xeroderma pigmentosum complementation group A individuals also develop UV resistance after a lower (0.2 Jm/sup -2/) exposure to UV. Enhanced UV resistance does not develop in UV-irradiated cell populations incubated with the protein synthesis inhibitor cycloheximide (5 ..mu..M). These observations are consistent with the interpretation that exposure of human fibroblasts to low doses of UV induces synthesis of a protein involved in a metabolic pathway that transiently enhances the capacity of cells to repair potentially lethal damage resulting from a subsequent dose of UV.

Tyrrell, R.M.

1984-02-01

73

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

74

Radiation Exposure from CT Examinations in Japan  

Microsoft Academic Search

BACKGROUND: Computed tomography (CT) is the largest source of medical radiation exposure to the general population, and is considered a potential source of increased cancer risk. The aim of this study was to assess the current situation of CT use in Japan, and to investigate variations in radiation exposure in CT studies among institutions and scanners. METHODS: Data-sheets were sent

Yoshito Tsushima; Ayako Taketomi-Takahashi; Hiroyuki Takei; Hidenori Otake; Keigo Endo

2010-01-01

75

Taste aversions conditioned with partial body radiation exposures  

SciTech Connect

Radiation-induced taste aversion was compared in rats which received partial body exposure to the head or abdomen with rats receiving whole body irradiation. Exposure levels ranged from 25 to 300 roentgens (R). In additional groups, saccharin aversion to partial body gamma ray exposures of the abdomen were conditioned in animals which had prior experience with the saccharin solution. Aversion was measured with a single-bottle short-term test, a 23-hour preference test and by the number of days taken to recover from the aversion. Whole-body exposure was most effective in conditioning the aversion, and exposure of the abdominal area was more effective than exposure to the head. Also, the higher the exposure, the stronger the aversion. Rats receiving prior experience with the saccharin did not condition as well as control rats with no prior saccharin experience. The possible role of radiation-induced taste aversion in human radiotherapy patients was discussed.

Smith, J.C.; Hollander, G.R.; Spector, A.C. (Florida State Univ., Tallahassee (USA). Dept. of Psychology)

1981-11-01

76

Ionizing radiation exposure of LDEF  

NASA Technical Reports Server (NTRS)

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

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

1990-01-01

77

Toxicologic methods: controlled human exposures.  

PubMed Central

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

Utell, M J; Frampton, M W

2000-01-01

78

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

79

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

80

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 (...

81

[Transgenerational effects of parental exposure to ionizing radiation].  

PubMed

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

Sadetzki, Siegal; Flint-Richter, Pazit

2006-07-01

82

Sources of confusion in establishment of radiation exposure guidelines  

SciTech Connect

There are several factors that induce the many fallacies underlying current radiation protection guidelines, and there is little hope on the horizon that common sense will prevail to override these fallacies. Radiation is looked upon by influential committee members as an absolute hazard to human health. In other words, they believe that all radiation is harmful at any level of exposure! There is no evidence for such a statement. This paper is separated into several major topics, each showing the reasons this philosophy concerning all radiation to be harmful is so misguided.

Thomas, R.G. [Robert Thomas, Bigfork, MT (United States)

1996-12-31

83

Radiation exposure modeling and project schedule visualization  

SciTech Connect

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

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

1995-10-01

84

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

85

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

86

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

87

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...

88

Radiation exposure and safety for the electrophysiologist.  

PubMed

This review attempts to give practical advice for invasive electrophysiologists on personal radiation protection. Applying all measures of the "As low as reasonably achievable" ALARA concept should be a daily and indeed routine practice for all staff in the electrophysiology laboratory. A substantial number of technical options have been recently introduced which may enable the physician to lower the total radiation exposure significantly, but all require a substantial learning curve. Using these measures can arrive at very low or indeed close to ZERO fluoroscopy exposure even in complex ablation cases. PMID:24022543

Ernst, Sabine; Castellano, Isabel

2013-10-01

89

DOE occupational radiation exposure 1996 report  

SciTech Connect

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

NONE

1996-12-31

90

HUMAN EXPOSURE MODELING: CONCEPTS, METHODS, AND TOOLS  

EPA Science Inventory

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

91

Urinary levels of thymine dimer as a biomarker of exposure to ultraviolet radiation in humans during outdoor activities in the summer.  

PubMed

The incidence of skin cancer is rising rapidly in many countries, presumably due to increased leisure time exposure to solar ultraviolet radiation (UVR). UVR causes DNA lesions, such as the thymine dimer (T=T), which have been causatively linked to the development of skin cancer. T=T is clearly detectable in urine and may, thereby, be a potentially valuable biomarker of UVR exposure. The objective of this study was to evaluate the relationship between UVR exposure and urinary levels of T=T in a field study involving outdoor workers. Daily ambient and personal exposure of 52 beach lifeguards and agricultural workers to UVR were determined (employing 656 personal polysulphone dosimeters). In 22 of these subjects, daily urinary T=T levels (120 samples) were measured, the area of skin exposed calculated and associations assessed utilizing mixed statistical models. The average daily UVR dose was approximately 600 J/m(2) (7.7 standard erythemal doses), i.e. about 20% of ambient UVR. T=T levels were correlated to UVR dose, increasing by about 6 fmol/µmol creatinine for each 100 J/m(2) increase in dose (average of the three preceding days). This is the first demonstration of a relationship between occupational UVR exposure and urinary levels of a biomarker of DNA damage. On a population level, urinary levels of T=T can be used as a biomarker for UVR exposure in the field. PMID:23339196

Liljendahl, Tove Sandberg; Blomqvist, Anna; Andersson, Eva M; Barregard, Lars; Segerbäck, Dan

2013-05-01

92

Ionizing radiation exposure of the population of the United States. [Contains glossary  

SciTech Connect

As accurate an assessment as possible was made of the overall exposure of the US population from all sources of ionizing radiation. These sources were categorized according to the origin of the exposure: natural radiation, occupational, the nuclear fuel cycle, consumer products, miscellaneous environmental sources connected with human activities, and medical diagnosis and therapy. This report provides a comprehensive account of the exposure of members of the US public to all sources of ionizing radiation. 77 refs., 1 fig., 21 tabs.

Not Available

1987-09-01

93

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

94

Ultraviolet Radiation Exposure and Cancer Risks  

Cancer.gov

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

95

Medical exposure to radiation and thyroid cancer.  

PubMed

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

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

2011-05-01

96

Immunoassay for Monitoring Environmental and Human Exposure  

E-print Network

such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo- p-dioxin (PCDDs), polychlorinated dibenzofurans (PCDFsImmunoassay for Monitoring Environmental and Human Exposure to the Polybrominated Diphenyl Ether) to monitor environmental and human exposure to polybrominated diphenyl ether BDE-47 that is used as a flame

Hammock, Bruce D.

97

Radically Reducing Radiation Exposure during Routine Medical Imaging  

Cancer.gov

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

98

Radiation exposure of fertile women in medical research studies  

SciTech Connect

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

Vetter, R.J.

1988-08-01

99

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

100

Radiation Exposure and Protection in Multislice CT  

Microsoft Academic Search

Technical progress in computed tomography (CT) has substantially increased the clinical efficacy of CT procedures and offered\\u000a promising new applications in diagnostic imaging. On the other hand, data from various national surveys have confirmed, as\\u000a a general pattern, the growing impact of CT as a major source of patient and population exposure. From a radiation-hygienic\\u000a point of view, it is

Christoph Hoeschen; Dieter Regulla; Maria Zankl; Helmut Schlattl; Gunnar Brix

101

Changes in Liver Metabolic Gene Expression from Radiation Exposure  

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

102

Efficient models for base station antennas for human exposure assessment  

Microsoft Academic Search

Two simple and accurate models for base-station (BS) panel antennas are proposed for human-exposure assessment. Panel antennas comprise an antenna array with low coupling between its unit cells. The proposed model is based on the superposition of shifted radiating field contributions in amplitude and phase of a unit cell of the panel antenna. In the first model, the electric field

Zwi Altman; Brigitte Begasse; Christian Dale; Andrzej Karwowski; Joe Wiart; Man-Fai Wong; Laroussi Gattoufi

2002-01-01

103

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

Code of Federal Regulations, 2011 CFR

... 2011-10-01 false Radiofrequency radiation exposure evaluation: mobile devices...Authorization Procedures Radiofrequency Radiation Exposure § 2.1091 Radiofrequency radiation exposure evaluation: mobile...

2011-10-01

104

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

Code of Federal Regulations, 2010 CFR

... false Preservation of individual occupational radiation exposure records. 952...223-75 Preservation of individual occupational radiation exposure records. ...criticality: Preservation of Individual Occupational Radiation Exposure Records (APR...

2010-10-01

105

Radiation exposure from radionuclides in ground water: an uncertainty analysis for selected exposure scenarios  

Microsoft Academic Search

The uncertainty of the potential radiation exposure of the general population has been estimated for a normalized contamination\\u000a of ground water that is being used as drinking water for humans and animals, for irrigation of food and feed crops, and for\\u000a fish production in freshwater bodies. The frequency distributions of annual effective dose equivalents were calculated assuming\\u000a a normalized activity

G. Pröhl; H. Müller

1996-01-01

106

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

SciTech Connect

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

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

2012-07-13

107

Human health effects of methylmercury exposure.  

PubMed

Mercury (Hg), and the organometallic compounds formed from it, are among the most toxic of substances to the global environment. Mercury is environmentally ubiquitous, and both wildlife and humans are exposed to the toxic effects of its environmental residues, primarily elemental mercury (Hg0), divalent mercury (Hg2+) and methylmercury (MeHg). Humans are exposed to different forms of Hg, and potential health risks have been reported from such exposures; examples of Hg exposure include mercury vapor from dental amalgams, occupational exposures and exposures during artisan and small-scale gold mining operations. Despite the significance of those foregoing Hg exposures, of particular concern is human and wildlife exposure to MeHg, a potent neurotoxicant. Once incorporated into the body, MeHg easily penetrates the blood-brain barrier and causes damage to the central nervous system, particularly in fetuses. It bioaacumulates and biomagnifies in the aquatic food chain; consequently, fish and seafood consumption is the major pathway by which humans are exposed to MeHg. MeHg is the focus of this review. It adversely affects humans and is currently the subject of intense public health interest and worldwide concern. In this review, I summarize the sources and cycling of global mercury in the environment, pathways of exposure, toxicity and exposure evaluation, toxicokinetics, the common biomarkers to evaluate exposure and effects in populations, and finally review the nutritional risks and benefits from fish consumption. PMID:19253038

Díez, Sergi

2009-01-01

108

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...

109

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

NASA Technical Reports Server (NTRS)

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

Tripathi, Ram K.; Nealy, John E.

2007-01-01

110

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...

111

Biological effects of radiation accidents on humans. (Latest citations from the NTIS bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning the impact of radiation accidents on humans. Citations discuss exposure assessment, malfunction and misuse of radiation sources, dosimetry, radiation epidemiology, radiation-induced neoplasms, and nuclear facility licensing. Environmental and occupational exposures, case studies, nuclear fallout, and radiation effects on food chains are examined. (Contains 50-250 citations and includes a subject term index and title list.)

NONE

1995-06-01

112

LPGS. Code System for Calculating Radiation Exposure  

SciTech Connect

LPGS was developed to calculate the radiological impacts resulting from radioactive releases to the hydrosphere. The name LPGS was derived from the Liquid Pathway Generic Study for which the original code was used primarily as an analytic tool in the assessment process. The hydrosphere is represented by the following types of water bodies: estuary, small river, well, lake, and one-dimensional (1-d) river. LPGS is designed to calculate radiation dose (individual and population) to body organs as a function of time for the various exposure pathways. The radiological consequences to the aquatic biota are estimated. Several simplified radionuclide transport models are employed with built-in formulations to describe the release rate of the radionuclides. A tabulated user-supplied release model can be input, if desired. Printer plots of dose versus time for the various exposure pathways are provided.

White, J.E.; Eckerman, K.F. [Oak Ridge National Lab., TN (United States)

1983-01-01

113

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...

114

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...

115

Human occupational and nonoccupational exposure to fibers.  

PubMed Central

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

Esmen, N A; Erdal, S

1990-01-01

116

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

117

Measurement methods for human exposure analysis.  

PubMed Central

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

Lioy, P J

1995-01-01

118

Screening radiation exposure for quality assurance.  

PubMed

Quality assurance for planned radiation exposure situations (e.g. Digital Radiography, Computed Tomography or Radio Fluoroscopic studies) requires the application of examination-specific scans protocols. These are tailored to patient age or size, body region and clinical indication for ensuring that the dose applied to each patient is as low as reasonably achievable for the clinical purpose of the image acquisition (ALARA principle). The European legal framework--2013/59/EURATOM--points that health authorities will be more pervasive on inspecting the dosimetry applied to patients. This paper discusses these legal alterations and presents an interoperable distributed system for dose monitoring, which is compliant with legal procedures and the IHE Radiation Exposure Monitoring profile (REM). The system combines the most representative stakeholders affected and directly interested in the patient radiological protection: patients, radiologists, practitioners, health authorities, and ethics committee. The system is capable of gathering, in real-time, dose information applied to the patient and storing it in a regional or national wide dose registry. The paper addresses which information should such systems hold and which should be accessed, from each stakeholder perspective. Furthermore, the system may detect irregular dose patterns, which could indicate dose abuses, and signal those findings to the appropriate stakeholders. PMID:25160261

Bastião Silva, Luís A; Ribeiro, Luís S; Santos, Milton; Costa, Carlos; Oliveira, José Luís

2014-01-01

119

Human exposure to dioxin from combustion sources  

SciTech Connect

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 dibenzofurnas (PCDFs) many people who live near MSW incinerators fear that they will be exposed to high levels of dioxin and subsequently develop cancer. What is often overlooked in this debate, however, is the fact that the general population is continuously being exposed to trace amounts of dioxin as exemplified by the fact that virtually all human adipose tissue samples contain dioxin at levels of 3 parts per trillion (ppt) or greater. This paper provides a perspective on MSW incineration as a source of human exposure to dioxin by comparing this exposure source with exposure to background environmental contamination and evaluates some of the potential key sources of PCDD/PCDF input into the enviroment. 32 refs., 3 tabs.

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

1988-01-01

120

Chromosomal "Fingerprints" of Prior Exposure to Densely Ionizing Radiation  

E-print Network

COMMENTARY Chromosomal "Fingerprints" of Prior Exposure to Densely Ionizing Radiation D. J. Brenner. Chromosomal "Fingerprints" of Prior Exposure to Densely Ionizing Radiation. Radiat. Res. 140,134-142 (1994 interest in finding a detectable biological "fingerprint" preferentially produced by densely ionizing

Brenner, David Jonathan

121

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

Microsoft Academic Search

Studies in the 1980s of medically irradiated populations have increased our knowledge of radiation carcinogenesis. (1) Investigations of prenatal x-ray exposures, especially in twins, provide evidence that very low doses of ionizing radiation may cause cancer in humans. (2) Fractionated doses appear as effective as single exposures of the same total dose in causing breast cancer, but seem less effective

John D. Boice; J. D. Jr

1988-01-01

122

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. PMID:24375779

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

2014-06-01

123

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

SciTech Connect

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

Morgan, William F.; Sowa, Marianne B.

2011-04-27

124

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...

125

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

126

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

127

Real and Perceived Risks of Medical Radiation Exposure  

PubMed Central

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

Hendee, William R.

1983-01-01

128

Cytokine and chemokine responses after exposure to ionizing radiation: Implications for the astronauts  

NASA Astrophysics Data System (ADS)

For individuals traveling in space, exposure to space radiation is unavoidable. Since adequate shielding against radiation exposure is not practical, other strategies for protecting the astronauts must be developed. Radiation is also an important therapeutic and diagnostic tool, and evidence from the clinical and experimental settings now shows a firm connection between radiation exposure and changes in cytokine and chemokine levels. These small proteins can be pro- or anti-inflammatory in nature and the balance between those two effects can be altered easily because of exogenous stresses such as radiation. The challenge to identify a common perpetrator, however, lies in the fact that the cytokines that are produced vary based on radiation dose, type of radiation, and the cell types that are exposed. Based on current knowledge, special treatments have successfully been designed by implementing administration of proteins, antibodies, and drugs that counteract some of the harmful effects of radiation. Although these treatments show promising results in animal studies, it has been difficult to transfer those practices to the human situation. Further understanding of the mechanisms by which cytokines are triggered through radiation exposure and how those proteins interact with one another may permit the generation of novel strategies for radiation protection from the damaging effects of radiation. Here, we review evidence for the connection between cytokines and the radiation response and speculate on strategies by which modulating cytokine responses may protect astronauts against the detrimental effects of ionizing radiations.

Laiakis, Evagelia C.; Baulch, Janet E.; Morgan, William F.

129

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

130

Human exposure to large solar particle events in space  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

131

Human exposure to large solar particle events in space  

NASA Astrophysics Data System (ADS)

Whenever energetic solar protons produced by solar particle events traverse bulk matter, they undergo various nuclear and atomic collision processes which significantly alter the physical characteristics and biologically important properties of their transported radiation fields. These physical interactions and their effect on the resulting radiation field within matter are described within the context of a recently developed deterministic, coupled neutron-proton space radiation transport computer code (BRYNTRN). Using this computer code, estimates of human exposure in interplanetary space, behind nominal (2 g/cm2) and storm shelter (20 g/cm2) thicknesses of aluminum shielding, are made for the large solar proton event of August 1972. Included in these calculations are estimates of cumulative exposures to the skin, ocular lens, and bone marrow as a function of time during the event. Risk assessment in terms of absorbed dose and dose equivalent is discussed for these organs. Also presented are estimates of organ exposures for hypothetical, worst-case flare scenarios. The rate of dose equivalent accumulation places this situation in an interesting region of dose rate between the very low values of usual concern in terrestrial radiation environments and the high dose rate values prevalent in radiation therapy.

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

132

Childhood exposure to external ionising radiation and solid cancer risk  

Microsoft Academic Search

The increasing use of ionising radiation for diagnostic purposes has raised concern about potential iatrogenic damage, especially in children. In this review, we discuss some aspects of radiation-induced cancer in relation to age at exposure and measures that should be taken for limiting exposure in this sensitive population.

S Sadetzki; L Mandelzweig

2009-01-01

133

RADIATION PERMIT APPLICATION Western Human Resources  

E-print Network

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

Sinnamon, Gordon J.

134

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

135

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...

136

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...

137

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

138

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

PubMed

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

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

2013-06-01

139

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

140

Cancer Risk Related to Gastrointestinal Diagnostic Radiation Exposure  

Microsoft Academic Search

Exposure to ionizing radiation is associated with an increased risk of cancer. With the growing use of diagnostic imaging\\u000a studies, there is concern for increasing the risk of radiation associated malignancy of the gastrointestinal tract. The purpose\\u000a of this review is to summarize the existing literature for risk of gastrointestinal malignancy after ionizing radiation exposure\\u000a from diagnostic imaging studies. Estimates

Mimi L. Chang; Jason K. Hou

141

DOE Basic Overview of Occupational Radiation Exposure_2011 pamphlet  

SciTech Connect

This pamphlet focusses on two HSS activities that help ensure radiation exposures are accurately assessed and recorded, namely: 1) the quality and accuracy of occupational radiation exposure monitoring, and 2) the recording, reporting, analysis, and dissemination of the monitoring results. It is intended to provide a short summary of two specific HSS programs that aid in the oversight of radiation protection activities at DOE. The Department of Energy Laboratory Accreditation Program (DOELAP) is in place to ensure that radiation exposure monitoring at all DOE sites is precise and accurate, and conforms to national and international performance and quality assurance standards. The DOE Radiation Exposure Monitoring Systems (REMS) program provides for the collection, analysis, and dissemination of occupational radiation exposure information. The annual REMS report is a valuable tool for managing radiological safety programs and for developing policies to protect individuals from occupational exposure to radiation. In tandem, these programs provide DOE management and workers an assurance that occupational radiation exposures are accurately measured, analyzed, and reported.

ORAU

2012-08-08

142

MicroRNA Expression Profiling Altered by Variant Dosage of Radiation Exposure  

PubMed Central

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

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

2014-01-01

143

Radiation exposure in gastroenterology: improving patient and staff protection.  

PubMed

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

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

2014-08-01

144

Identifying radiation exposure biomarkers from mouse blood transcriptome  

PubMed Central

Ionising radiation is a pleiotropic stress agent that may induce a variety of adverse effects. Molecular biomarker approaches possess promise to assess radiation exposure, however, the pleiotropic nature of ionising radiation induced transcriptional responses and the historically poor inter-laboratory performance of omics-derived biomarkers serve as barriers to identification of unequivocal biomarker sets. Here, we present a whole-genome survey of the murine transcriptomic response to physiologically relevant radiation doses, 2 Gy and 8 Gy. We used this dataset with the Random Forest algorithm to correctly classify independently generated data and to identify putative metabolite biomarkers for radiation exposure. PMID:23797995

Laiakis, Evagelia C.; Li, Heng-Hong; Fornace, Albert J.

2014-01-01

145

Radiation protection for human interplanetary spaceflight and planetary surface operations  

SciTech Connect

Radiation protection issues are reviewed for five categories of radiation exposure during human missions to the moon and Mars: trapped radiation belts, galactic cosmic rays, solar flare particle events, planetary surface emissions, and on-board radiation sources. Relative hazards are dependent upon spacecraft and vehicle configurations, flight trajectories, human susceptibility, shielding effectiveness, monitoring and warning systems, and other factors. Crew cabins, interplanetary mission modules, surface habitats, planetary rovers, and extravehicular mobility units (spacesuits) provide various degrees of protection. Countermeasures that may be taken are reviewed relative to added complexity and risks that they could entail, with suggestions for future research and analysis.

Clark, B.C. [Armed Forces Radiobiology Research Inst., Bethesda, MD (United States); [DLR Inst. of Aerospace Medicine, Cologne (Germany); [NASA, Goddard Space Flight Center, Greenbelt, MD (United States)

1993-12-31

146

Variation of Space Radiation Exposure inside Spherical and Hemispherical Geometries  

NASA Astrophysics Data System (ADS)

We calculate the space radiation exposure to blood-forming organs everywhere inside a hemispherical dome that represents a lunar habitat. We derive the analytical path length distribution from any point inside a hemispherical or a spherical shell. Because the average path length increases with the distance from the center, the center of the hemispherical dome on the lunar surface has the largest radiation exposure while locations on the inner surface of the dome have the lowest exposure. This conclusion differs from an earlier study on a hemispherical dome but agrees with another earlier study on a spherical-shell shield. We also find that the reduction in the radiation exposure from the center to the inner edge of the dome can be as large as a factor of 3 or more for the radiation from solar particle events while being smaller for the radiation from galactic cosmic rays.

Lin, Zi-Wei; Baalla, Younes; Townsend, Lawrence

2008-10-01

147

Cellular effects of ultrawideband ultrashort pulsed radiation and microwave radiation exposure  

Microsoft Academic Search

The experimental data obtained since 2000 concerning cellular and molecular effects evoked in biological systems by exposure to ultrawideband ultrashort pulsed radiation and microwave radiation are discussed. The most significant cellular effects of electromagnetic fields exposure, such as: apoptosis, cell proliferation, genotoxic effects, and some underlining molecular processes are considered. Conclusion: the cell reaction to ultrawideband ultrashort pulsed radiation and

Y. G. Shckorbatov; N. N. Kolchigin; V. A. Grabina; V. N. Pasiuga

2010-01-01

148

Human exposure to urban air pollution.  

PubMed Central

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

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

1994-01-01

149

Patient radiation exposure during transcatheter aortic valve replacement procedures  

PubMed Central

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

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

2013-01-01

150

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

Federal Register 2010, 2011, 2012, 2013

...Collection; Radiation Sampling and Exposure Records...collection for Radiation Sampling and Exposure Records...any of the following methods: (1) Electronic mail...provisions for radiation sampling and exposure records...not employ statistical methods. Type of Review:...

2010-12-17

151

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

Federal Register 2010, 2011, 2012, 2013

...Collection; Radiation Sampling and Exposure Records...collection for Radiation Sampling and Exposure Records...any of the following methods: (1) Electronic mail...provisions for radiation sampling and exposure records...not employ statistical methods. Type of Review:...

2010-12-21

152

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

Federal Register 2010, 2011, 2012, 2013

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

2010-08-10

153

Human biomonitoring issues related to lead exposure.  

PubMed

Lead as a toxic environmental metal has been an issue of concern for 30-40 years. Even though the exposures experienced by the general public have been significantly reduced, so have the acceptable blood lead concentrations assessed to safeguard health (specifically of children). The impact of these concurrent changes are reviewed and discussed in terms of the following: blood lead as the primary biomarker of exposure; pertinent toxicokinetic issues including modelling; legacy and newer sources of this toxic metal; improvements in lead quantification techniques and its characterization (chemical forms) in exposure media; and in vivo markers of lead sources. It is concluded that the progress in the quantification of lead and its characterization in exposure media have supported the efforts to identify statistical associations of lead in blood and tissues with adverse health outcomes, and have guided strategies to reduce human exposure (especially for children). To clarify the role of lead as a causative factor in disease, greater research efforts in biomarkers of effect and susceptibility seem timely. PMID:23970117

Nieboer, Evert; Tsuji, Leonard J S; Martin, Ian D; Liberda, Eric N

2013-10-01

154

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

155

National Report on Human Exposure to Environmental Chemicals  

MedlinePLUS

... Cancel Submit Search The CDC National Report on Human Exposure to Environmental Chemicals Note: Javascript is disabled ... 6,517 KB] The Fourth National Report on Human Exposure to Environmental Chemicals, 2009 , (the Fourth Report, ...

156

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

157

Radiation Exposure from Medical Exams and Procedures  

MedlinePLUS

... 6.9 (690) Hepatobiliary (liver flow) 99m Tc Sulfur Colloid 2.1 (210) Bone 99mTc MDP 6. ... radiation (absorbed dose) or to the potential biological effect in tissue exposed to radiation (equivalent dose). Sv ...

158

Gene Expression Profiling of Biological Pathway Alterations by Radiation Exposure  

PubMed Central

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

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

2014-01-01

159

Radiation Exposure in X-Ray and CT Examinations  

MedlinePLUS

... Radiation exposure from interventional radiology procedures Safety in nuclear medicine procedures What are x-rays and what do they do? X-rays are forms of radiant energy, like light or radio waves. Unlike light, x- ...

160

ULTRAVIOLET PROTECTIVE COMPOUNDS AS A RESPONSE TO ULTRAVIOLET RADIATION EXPOSURE  

EPA Science Inventory

Life on Earth has evolved adaptations to many environmental stresses over the epochs. One consistent stress has been exposure to ultraviolet radiation. In response to UVR organisms have adapted myriad responses; behavioral, morphological and physiological. Behaviorally, some orga...

161

Radiation Metabolomics. 5. Identification of Urinary Biomarkers of Ionizing Radiation Exposure in Nonhuman Primates by Mass Spectrometry-Based Metabolomics  

PubMed Central

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

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

2012-01-01

162

Inpatient radiation exposure in patients with spinal trauma  

PubMed Central

Context/objective Radiation exposure from medical imaging is an important patient safety consideration; however, patient exposure guidelines and information on cumulative inpatient exposure are lacking. Design/setting Trauma patients undergo numerous imaging studies, and spinal imaging confers a high effective dose; therefore, we examined cumulative effective radiation dose in patients hospitalized with spinal trauma. We hypothesized that people with spinal cord injury (SCI) would have higher exposures than those with spine fractures due to injury severity. Particpants/interventions Retrospective data were compiled for all patients with spine injuries admitted to a level I trauma center over a 2-year period. Outcome measures Injury severity score (ISS) and cumulative radiation exposure were then determined for these patients, including 406 patients with spinal fractures and 59 patients with SCI. Results Cumulative effective dose was 45 millisieverts (mSv) in SCI patients, compared to 38 mSv in spinal fracture patients (P = 0.01). Exposure was higher in patients with an ISS over 16 (P = 0.001). Mean exposure in both groups far exceeded the European annual occupational exposure maximum of 20 mSv. More than one-third of patients with SCI exceeded the US occupational maximum of 50 mSv. Conclusion Patients with SCI had significantly higher radiation exposure and ISS than those with spine fracture, but the effective dose was globally high. Dose did not correlate with injury severity for patients with SCI. While the benefits of imaging are clear, radiation exposure does involve risk and we urge practitioners to consider cumulative exposure when ordering diagnostic tests. PMID:23809525

Martin, Elizabeth; Prasarn, Mark; Coyne, Ellen; Giordano, Brian; Morgan, Thomas; Westessen, Per-Lennart; Wright, John; Rechtine, Glenn

2013-01-01

163

Childhood cancer and occupational radiation exposure in parents  

SciTech Connect

To test the hypothesis that a parent's job exposure to radiation affeOR). its his or her child's risk of cancer, the authors compared this exposure during the year before the child's birth for parents of children with and without cancer. Parents of children with cancer were no more likely to have worked in occupations, industries, or combined occupations and industries with potential ionizing radiation exposure. Bone cancer and Wilms' tumor occurred more frequently among children of fathers in all industries with moderate potential ionizing radiation exposure. Children with cancer more often had fathers who were aircraft mechanics (odds ratio (OR)) . infinity, one-sided 95% lower limit . 1.5; P . 0.04). Although four of these six were military aircraft mechanics, only children whose fathers had military jobs with potential ionizing radiation exposure had an increased cancer risk (OR . 2.73; P . 0.01). Four cancer types occurred more often among children of fathers in specific radiation-related occupations: rhabdomyosarcoma among children whose fathers were petroleum industry foremen; retinoblastoma among children whose fathers were radio and television repairmen; central nervous system cancers and other lymphatic cancers among children of Air Force fathers. Because numbers of case fathers are small and confidence limits are broad, the associations identified by this study need to be confirmed in other studies. Better identification and gradation of occupational exposure to radiation would increase the sensitivity to detect associations.

Hicks, N.; Zack, M.; Caldwell, G.G.; Fernbach, D.J.; Falletta, J.M.

1984-04-15

164

Childhood cancer and occupational radiation exposure in parents  

Microsoft Academic Search

To test the hypothesis that a parent's job exposure to radiation affeOR). its his or her child's risk of cancer, the authors compared this exposure during the year before the child's birth for parents of children with and without cancer. Parents of children with cancer were no more likely to have worked in occupations, industries, or combined occupations and industries

Nancy Hicks; Matthew Zack; Glyn G. Caldwell; Donald J. Fernbach; John M. Falletta

1984-01-01

165

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.  

PubMed

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. PMID:12710869

Morgan, William F

2003-05-01

166

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

167

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

168

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

PubMed Central

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

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

2013-01-01

169

Naturally occurring radiation sources: existing or planned exposure situation?  

PubMed

After more than fifteen years of application, ICRP Publication 60 has been revised. The revision was based upon the concept of 'controllable dose' as the dose or sum of doses to an individual from a particular source that can reasonably be controlled by whatever means. The new recommendations have been published as ICRP Publication 103. The European Basic Safety Standards as well as the International Basic Safety Standards are currently under revision as a result of the new recommendations from ICRP. According to the ICRP, there have been indications that some changes to the structure and terminology of the system of protection were desirable in order to improve clarity and utility. In particular the distinction between practices and interventions may not have been clearly understood and the ICRP now recognises three types of exposure situations, which replace the previous categorisation into practices and interventions. These exposure situations are intended to cover the entire range of exposure situations: (1) planned exposure, (2) existing exposure and (3) emergency exposure. There are situations of exposure to naturally occurring radiation sources in different occupations, e.g. exposure to radon and radon progeny in workplaces other than where the exposure is required by or is directly related to the work and aircrew exposed to cosmic radiation. In the European (Euratom) and the International Basic Safety Standards, these exposure situations are treated conceptually different-either as a planned exposure situation or as an existing exposure situation. This note reviews the change of exposure situations from Publication 60 to Publication 103 and the implications for the revision of both the International and the European Basic Safety Standards. The paper draws some conclusions on the classification of the exposure situations in the two basic safety standards based on a logical interpretation of the ICRP recommendations. It is recommended that the European and the International Basic Safety Standards should be harmonised to avoid confusion among users of the standards. PMID:21149941

Hedemann-Jensen, Per

2010-12-01

170

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

EPA Science Inventory

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

171

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

172

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

173

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

PubMed

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

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

2014-03-01

174

Effects of parental radiation exposure on developmental instability in grasshoppers  

PubMed Central

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

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

2014-01-01

175

Effect of simultaneous exposure to toluene and xylene on their respective biological exposure indices in humans  

Microsoft Academic Search

Summary Studies that specifically address the influence of controlled human exposure to a combination of solvents on the biological monitoring of exposure are limited in number. The present study was undertaken to investigate whether simultaneous exposure of human volunteers to toluene and xylene could modify the respective metabolic disposition of these solvents. Five adult Caucasian men were exposed for 7

R. Tardif; S. Laparé; G. L. Plaa; J. Brodeur

1991-01-01

176

Human exposure to pollutants in Poland  

SciTech Connect

Serious environmental problems caused by decades of mismanagement of Poland's natural resources have been brought to light in recent years. All environmental media--air, water, food, and soil--have been burdened with toxic chemicals. Some environmental problems are so severe that the sources of pollution and the mitigation techniques needed are obvious, requiring no further research, but rather common sense, monies, and determination to implement the necessary controls and mitigation procedures. This paper will not address these obvious cases. Rather it will address that spectrum of environmental problems which requires a better understanding of public health risk in order to develop effective risk management strategies. Because these problems are numerous and monies limited, policy makers will need to set priorities both for research projects and control options. Using environmental concentration data presently available from Poland (especially for air), the paper will estimate human exposures, will point out research and monitoring needs, and hopefully, will lend credence to the concept that environmental policies and risk reduction strategies will be most effective if the Total Human Exposure Concept is used as the guiding scientific principle in risk assessment and management programs.

Wesolowski, J.J.; Jedrychowski, W.; Flak, E. (California Department of Health Services, Berkeley (United States))

1992-07-01

177

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

178

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

179

Radiation Exposure to Interventional Radiologists During Manual-Injection Digital Subtraction Angiography  

Microsoft Academic Search

Purpose: We investigated the relationship between the amount of radiation exposure to the operator during table-side manual-injection angiographic procedures including digital subtraction angiography (DSA) and the operator's position, as well as a simple means to decrease radiation exposure. Methods: Measurement of radiation exposure was carried out with thermoluminescent dosimeters (TLDs) in nine abdominal angiographies. In the first study, radiation exposure

Nobushige Hayashi; Toyohiko Sakai; Manabu Kitagawa; Rika Inagaki; Toru Yamamoto; Tetsuya Fukushima; Yasushi Ishii

1998-01-01

180

Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Comprehensive progress report, January 1, 1980-December 31, 1982  

SciTech Connect

The observations that two particular translocations are consistently associated with specific differentiation stages of acute nonlymphocytic leukemia were confirmed. These are the translocation between chromosomes 8 and 21 in acute myeloblastic leukemia with maturation and the translocation between chromosomes 15 and 17 in acute promyelocytic leukemia. The observation of others that structural rearrangements involving the long arm of No. 11 are frequently seen in acute monoblastic leukemia was also confirmed. The chromosome aberrations that are observed in the great majority of patients with acute leukemia secondary to cytotoxic therapy were defined. Thus of 47 patients with secondary acute nonlymphocytic leukemia, an aneuploid clone was seen in 44, and 39 of the 44 had a loss of part or all of No. 5 and/or No. 7. I have been able to localize the region of chromosome No. 7, loss of which is important for the development of leukemia was localized. Patients with ANLL de novo whose occupational histories suggest exposure to potentially mutagenic agents have a higher frequency of aberrations involving Nos. 5 and/or 7, than do patients not so exposed. Thus 50% of exposed versus 10% of nonexposed patients had aberrations of Nos. 5 or 7.

Rowley, J.D.

1982-06-01

181

Assessing radiation exposure during endoscopic-guided percutaneous nephrolithotomy  

PubMed Central

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

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

2014-01-01

182

DIETARY EXPOSURE AND TOTAL HUMAN EXPOSURE ASSESSMENT:AN OVERVIEW  

EPA Science Inventory

In this paper I discuss the goals and accomplishments in the dietary research program of USEPA's National Exposure Research Laboratory (NERL). NERL dietary exposure research has the primary goal of establishing measurement methods for dietary ingestion that are consistent with an...

183

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

184

HUMAN EXPOSURE ESTIMATION FOR 2,3,7,8-TCDD  

EPA Science Inventory

Exposure assessment procedures have been developed using relevant and likely scenarios through which humans could be exposed to dioxin-contaminated soil. Five exposure pathways were chosen for analysis: dust inhalation; fish ingestion; dermal absorption; soil ingestion; and, beef...

185

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 ...

186

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

187

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

188

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

Code of Federal Regulations, 2013 CFR

...Preservation of individual occupational radiation exposure records. 952.223-75...Preservation of individual occupational radiation exposure records. As prescribed...planning and execution, or 952.223-72, Radiation protection and nuclear...

2013-10-01

189

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

Code of Federal Regulations, 2012 CFR

...Preservation of individual occupational radiation exposure records. 952.223-75...Preservation of individual occupational radiation exposure records. As prescribed...planning and execution, or 952.223-72, Radiation protection and nuclear...

2012-10-01

190

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

191

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

... 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)...

2014-07-01

192

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

Code of Federal Regulations, 2010 CFR

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

2010-07-01

193

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

194

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

Code of Federal Regulations, 2011 CFR

...Preservation of individual occupational radiation exposure records. 952.223-75...Preservation of individual occupational radiation exposure records. As prescribed...planning and execution, or 952.223-72, Radiation protection and nuclear...

2011-10-01

195

Review of retrospective dosimetry techniques for external ionising radiation exposures.  

PubMed

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

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

2011-11-01

196

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. PMID:19095959

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

2009-01-01

197

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

198

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

199

Spore dosimetry of solar UV radiation: applications to monitoring of daily irradiance and personal exposure.  

PubMed

Environmental UV radiation can be quantified using spore dosimetry, which measures the inactivation of repair-deficient Bacillus subtilis spores dried on a membrane filter. The system exhibits highly selective sensitivity to UV radiation, not being affected by various environmental adversities, such as high and low temperature and humidity. Biologically-effective dose rate and cumulative dose of ambient radiation are measurable under various conditions at various places on the earth, including tropical, temperate, and polar sites. Applications to monitor the exposure at the surface of organisms including humans and plants have also been advanced. PMID:12038485

Munakata, N; Makita, K; Bolsee, D; Gillotay, D; Horneck, G

2000-01-01

200

Preventable Exposures Associated With Human Cancers  

PubMed Central

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

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

2011-01-01

201

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

202

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

203

Human Genetic Marker for Resistance to Radiation and Chemicals  

SciTech Connect

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

DR. Howard B. Lieberman

2001-05-11

204

Radiation exposure of U.S. military individuals.  

PubMed

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

Blake, Paul K; Komp, Gregory R

2014-02-01

205

Human radiation experiments: Looking beyond the headlines  

SciTech Connect

There has been a great deal of publicity recently about experiments supported by the U.S. Department of Energy and its predecessors, the Atomic Energy Commission (AEC) and the Energy Research and Development Administration, in which human subjects were exposed to radiation. Media stories give the impression that these experiments were done in secret, without informing the subjects, and that these subjects suffered horrible consequences. As a prelude to understanding the situation, it is useful to review the bases for judgement in deciding on this type of experiment. When it was first recognized that radiation can be harmful, national and international groups promulgated the concept of {open_quotes}maximum permissible dose{close_quotes} (MPD) on the basis that with a comfortable factor of safety (e.g., a factor of 10), there was no evidence of harm at that level. This had always been the principal method of providing safety, applied to everything from chemicals to bridges. In the 1940s, the MPD was 100 mrem per day, and it was assumed that there would be no harmful health impacts at that level. Current regulations require that experiments involving radiation exposure to human subjects be approved by a review board at the institution where they are carried out. National guidelines for these review boards require that whole-body doses to subjects be kept below 2 rem except in extraordinary circumstances. As an example of how these regulations are currently implemented, consider positron emission tomography (PET), a very active medical research topic for the past few years. In one major medical center, this involves exposing about 300 subjects per year, normally recruited through newspaper advertisements, with an average dose of about 400 mrem to each. There are about 50 comparable medical centers throughout the United States.

Cohen, B.L. [Univ. of Pittsburgh, PA (United States)

1994-03-01

206

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

SciTech Connect

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

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

2013-12-01

207

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

208

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

PubMed Central

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

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

2008-01-01

209

AIRCREW EXPOSURE FROM COSMIC RADIATION ON COMMERCIAL AIRLINE ROUTES  

Microsoft Academic Search

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

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

210

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

211

DOE Radiation Exposure Monitoring System (REMS) Data Update  

SciTech Connect

This slide show presents the 2011 draft data for DOE occupational radiation exposure.Clarification is given on Reporting Data regarding: reporting Total Organ Dose (TOD); reporting Total Skin Dose (TSD), and Total Extremity Dose (TExD) ; and Special individuals reporting.

Rao, Nimi; Hagemeyer, Derek

2012-05-05

212

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

213

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

SciTech Connect

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

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

1980-07-01

214

Radiation exposure at ground level by secondary cosmic radiation.  

PubMed

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 terms of H*(10). First results from long-term measurements at the PTB reference site for ambient radiation dosimetry are reported. The air pressure corrected dose rate shows, as expected, a strong correlation with the neutron count rate as measured with the Kiel neutron monitor. The measured seasonal variations exhibit a negative correlation with the temperature changes in the upper layers of the atmosphere where the ground level muons are produced. PMID:15856557

Wissmann, F; Dangendorf, V; Schrewe, U

2005-01-01

215

Radiation exposure to angiographers under different fluoroscopic imaging conditions  

SciTech Connect

Radiation levels near an imaging chain commonly used in angiography were measured with both a 100- and a 200-mm-thick scatter phantom. The scatter was measured in lines parallel in space to the central ray of the x-ray beam, at lateral distances of 300, 500, and 800 mm. The effects of fluoroscopic kilovoltage and image intensifier magnification mode were also measured. The results indicate that the highest scattered radiation levels occur near the surface of the patient where the x-ray beam enters. Exposure rates were measured in both anteroposterior (AP) and posteroanterior (PA) geometries on a U-arm system. In PA geometry, the highest radiation levels occur below the angiographer's waist, an area well protected by the lead apron. The AP geometry increases the exposure rate to the neck, head, and upper extremities, areas where apron shielding is less effective.

Boone, J.M.; Levin, D.C. (Thomas Jefferson University, Philadelphia, PA (USA))

1991-09-01

216

Tryptophan Cluster Protects Human ?D-Crystallin from Ultraviolet Radiation-Induced Photoaggregation  

E-print Network

Exposure to ultraviolet radiation (UVR) is a significant risk factor for age-related cataract, a disease of the human lens and the most prevalent cause of blindness in the world. Cataract pathology involves protein misfolding ...

Schafheimer, Steven Nathaniel

217

The effect of headset and earphone on reducing electromagnetic radiation from mobile phone toward human head  

Microsoft Academic Search

Studies show that exposure to the electromagnetic wave for a certain period of time will leads to health problem such as headaches, or even worse, brain cancer. Scientist have known that this radiation might cause human biological damage through heating effects since human body is made up of approximately 65-70% water, electrolytes and ions. Radio frequency radiation emitted from mobile

D. A. A. Mat; F. Kho; A. Joseph; K. Kipli; S. Sahrani; K. Lias; A. S. W. Marzuki

2010-01-01

218

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

219

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.

220

Solar ultraviolet radiation exposure of infants and small children.  

PubMed

Townsville, in Queensland, Australia, experiences very high levels of ambient solar ultraviolet radiation (UVR) throughout the year and has a predominantly white population which is prone to developing skin cancer. The UVR exposure of 1-year-old and 2 1/2-year-old children raised in Townsville was measured using UVR-sensitive polysulphone film badges. In two separate exposure studies undertaken for 7 days in October 1995 and 5 days in April 1997, exposure at the chest and shoulder for each subject was determined. The chest exposures for the 1-year-olds were significantly higher at weekends than on weekdays, whereas for the 2 1/2-year-old children the shoulder exposures were significantly higher at weekends than on weekdays. The median daily total exposure for 1-year-old infants was 0.4 SED (standard erythemal dose) for the chest and 0.4 SED for the shoulder. The median daily total exposure for 2 1/2-year-olds was 0.6 SED for the chest and 0.9 SED for the shoulder. Although the median daily total exposures were comparatively low, the maximum values for the chest and shoulder were 6.5 SED and 2.4 SED, respectively, for the 1-year-old infants, and 20.6 SED and 8.4 SED, respectively, for the 2 1/2-year-olds. While the 2 1/2-year-old children spent most of their time outside between 9 am and 4 pm, the 1-year-old infants spent more time outside before 9 am and after 4 pm. Exposure increases with age in early childhood. Increased mobility and a greater tendency to play outdoors is likely to account for the higher exposure levels in 2 1/2-year-old children, compared to 1-year-old infants. PMID:10404720

Moise, A F; Harrison, S L; Gies, H P

1999-01-01

221

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

222

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

223

Sunlight Exposure and (Sero)Prevalence of Epidermodysplasia Verruciformis-Associated Human Papillomavirus  

Microsoft Academic Search

Ultraviolet radiation (UVR) is associated with an increased risk of squamous cell carcinoma (SCC), which is in part due to immunomodulation. In addition, human papilloma virus (HPV), especially the epidermodysplasia verruciformis (EV)-associated types, may be involved. In view of the capacity of UVR to impair host resistance to infections, we investigated the relationship between solar exposure and the prevalence of

Fabian Termorshuizen; Mariet C. W. Feltkamp; Linda Struijk; Frank R. de Gruijl; Jan Nico Bouwes Bavinck; Henk van Loveren

2004-01-01

224

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

PubMed

Exposure of human cryopreserved spermatozoa to millimeter-wave electromagnetic radiation of 0.03 mW/cm(2) density for 5 min in normozoospermia and for 15 min in asthenozoospermia lead to increase of the fraction of mobile spermatozoa without impairing the membrane integrity and nuclear chromatin status and without apoptosis generation. PMID:25257416

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

2014-09-01

225

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

226

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

227

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

228

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

229

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

230

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Surveys of ambient radiation exposure rate...General Technical Requirements § 35.70 Surveys of ambient radiation exposure rate. (a) In addition to the surveys required by Part 20 of this...

2010-01-01

231

Peer assessment of pediatric surgeons for potential risks of radiation exposure from computed tomography scans  

Microsoft Academic Search

PurposeRadiology literature reports potential cancer risk from radiation exposure from computed tomography (CT). We hypothesized that pediatric surgeons' knowledge of potential risks of radiation exposure from CT scan is limited.

Henry E. Rice; Donald P. Frush; Matthew J. Harker; Diana Farmer; John H. Waldhausen

2007-01-01

232

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

Code of Federal Regulations, 2010 CFR

...Radiofrequency radiation exposure evaluation: mobile devices. 2.1091 Section 2.1091...Radiofrequency radiation exposure evaluation: mobile devices. (a) Requirements of...b) For purposes of this section, a mobile device is defined as a...

2010-10-01

233

Tracking the pathways of human exposure to perfluorocarboxylates.  

PubMed

Recent analyses of perfluorooctanoate (PFOA) in human blood sera show that the background-exposed population in industrialized countries worldwide exhibits a narrow concentration range; arithmetic means of published studies range between 2 and 8 microg/L PFOA, with the exception of a few outlier studies. The globally comparable human serum concentrations of PFOA and characteristic dominance of PFOA with respect to other perfluorocarboxylate (PFCA) homologues indicate that exposure pathways of humans differ from those of wildlife, where perfluorononanoate (PFNA) is often the dominant homologue. The observed correlations between perfluorooctane sulfonate (PFOS) and PFOA in human serum together with a simultaneous downward time trend of these compounds in human blood sera and blood spots from the year 2000 onward indicate a connection between historical perfluorooctanesulfonyl (POSF) production (phased out by the major manufacturer in 2000-2002) and exposure to both PFOS and PFOA. A comparison of estimated daily intakes to humans based on samples from exposure media (collected post 2000) indicates that food intake is the major contemporary exposure pathway for the background population, whereas drinking water exposure is dominant for populations near sources of contaminated drinking water. A one-compartment pharmacokinetic model used to back-calculate daily intakes from serum levels is shown to provide agreement within a factor of 1.5-5.5 of the daily intakes derived from exposure media, which provides further supporting evidence that dietary exposure is a major ongoing exposure pathway of PFOA to the background population. PMID:19731646

Vestergren, Robin; Cousins, Ian T

2009-08-01

234

Management of cosmic radiation exposure for aircraft crew in Japan.  

PubMed

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

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

2011-07-01

235

Study Regarding Electromagnetic Radiation Exposure Generated By Mobile Phone  

SciTech Connect

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

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

2011-12-26

236

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

237

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

238

Radiation Exposure Alters Expression of Metabolic Enzyme Genes In Mice  

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

239

Radiation Exposure During Fluoroarthroscopically Assisted Anterior Cruciate Reconstruction  

Microsoft Academic Search

We prospectively evaluated the radiation exposure dur ing 50 consecutive fluoroscopically assisted anterior cruciate ligament reconstructions. Three different meth ods of anterior cruciate ligament reconstruction were performed using either rolled fascia lata allograft or bone-tendon-bone autograft. For the 50 procedures, to tal time using the fluoroscope was 119.61 minutes, or 2.38 minutes per procedure. The 16 primary fascia lata allograft

Brad J. Larson; Julie Egbert; E. Marlowe Goble

1995-01-01

240

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

241

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

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Radiation Exposure Compensation Act Offset...CONTINUED) CLAIMS UNDER THE RADIATION EXPOSURE COMPENSATION ACT Pt. 79, App. C Appendix C to Part 79—Radiation Exposure Compensation Act...

2012-07-01

242

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 79—Radiation Exposure Compensation Act...

2013-07-01

243

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

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Radiation Exposure Compensation Act Offset...CONTINUED) CLAIMS UNDER THE RADIATION EXPOSURE COMPENSATION ACT Pt. 79, App. C Appendix C to Part 79—Radiation Exposure Compensation Act...

2011-07-01

244

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

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Radiation Exposure Compensation Act Offset...CONTINUED) CLAIMS UNDER THE RADIATION EXPOSURE COMPENSATION ACT Pt. 79, App. C Appendix C to Part 79—Radiation Exposure Compensation Act...

2010-07-01

245

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

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

2014-07-01

246

Relationship between monoclonal gammopathy of undetermined significance and radiation exposure in Nagasaki atomic bomb survivors  

Microsoft Academic Search

Radiation exposure is a possible predis- posing factor for monoclonal gammopa- thy of undetermined significance (MGUS), but the association has been uncertain. We investigated the relationship between radiation exposure and MGUS prevalence by using data from the M-protein screen- ing for Nagasaki atomic bomb survivors between 1988 and 2004. Radiation expo- sure was assessed by exposure distance from the hypocenter

Masako Iwanaga; Masuko Tagawa; Kunihiro Tsukasaki; Tatsuki Matsuo; Ken-ichi Yokota; Yasushi Miyazaki; Takuya Fukushima; Tomoko Hat; Yoshitaka Imaizumi; Daisuke Imanishi; Jun Taguchi; Sabro Momita; Shimeru Kamihira; Masao Tomonaga

247

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

248

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

Code of Federal Regulations, 2012 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...

2012-07-01

249

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

Code of Federal Regulations, 2011 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...

2011-07-01

250

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

251

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

Code of Federal Regulations, 2010 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...

2010-07-01

252

HEALTH RISKS OF HUMAN EXPOSURE TO WASTEWATER  

EPA Science Inventory

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

253

Medical mitigation strategies for acute radiation exposure during spaceflight.  

PubMed

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

Epelman, Slava; Hamilton, Douglas R

2006-02-01

254

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

255

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

256

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

257

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...

258

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...

259

NATIONAL REPORT ON HUMAN EXPOSURE TO ENVIRONMENTAL CHEMICALS  

EPA Science Inventory

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

260

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...

261

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

262

High throughput heuristics for prioritizing human exposure to environmental chemicals.  

PubMed

The risk posed to human health by any of the thousands of untested anthropogenic chemicals in our environment is a function of both the hazard presented by the chemical and the extent of exposure. However, many chemicals lack estimates of exposure intake, limiting the understanding of health risks. We aim to develop a rapid heuristic method to determine potential human exposure to chemicals for application to the thousands of chemicals with little or no exposure data. We used Bayesian methodology to infer ranges of exposure consistent with biomarkers identified in urine samples from the U.S. population by the National Health and Nutrition Examination Survey (NHANES). We performed linear regression on inferred exposure for demographic subsets of NHANES demarked by age, gender, and weight using chemical descriptors and use information from multiple databases and structure-based calculators. Five descriptors are capable of explaining roughly 50% of the variability in geometric means across 106 NHANES chemicals for all the demographic groups, including children aged 6-11. We use these descriptors to estimate human exposure to 7968 chemicals, the majority of which have no other quantitative exposure prediction. For thousands of chemicals with no other information, this approach allows forecasting of average exposure intake of environmental chemicals. PMID:25343693

Wambaugh, John F; Wang, Anran; Dionisio, Kathie L; Frame, Alicia; Egeghy, Peter; Judson, Richard; Setzer, R Woodrow

2014-11-01

263

Biomarkers of organophosphorus (OP) exposures in humans  

PubMed Central

There are ongoing events where aircraft engine lubricant containing tricresyl phosphates (TCPs) contaminates aircraft cabins. Some individuals have experienced tremors or other neurological symptoms that may last for many months following exposures. Mass spectrometric (MS) protocols are being developed to determine the percentage of “biomarker proteins” that are modified by such exposures, specifically on active site serines. Both plasma butyrylcholinesterase (BChE) and red cell acylpeptide hydrolase (APH) are readily inhibited by 2-(o-cresyl)-4H-1:3:2:benzodioxaphosphoran-2-one (CBDP) or phenyl saligenin cyclic phosphate (PSP) and have the potential to provide information about the level of exposure of an individual. We have developed immunomagnetic bead-based single-step purification protocols for both BChE and APH and have characterized the active site serine adducts of BChE by MS. PMID:21767566

Marsillach, Judit; Richter, Rebecca J.; Kim, Jerry H.; Stevens, Richard C.; MacCoss, Michael J.; Tomazela, Daniela; Suzuki, Stephanie M.; Schopfer, Lawrence M; Lockridge, Oksana; Furlong, Clement E.

2011-01-01

264

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

265

Radiation and Human Space Exploration  

NASA Video Gallery

Just outside the protective layer of Earth?s atmosphere and magnetosphere, is a universe full of radiation. What happens to our bodies when we leave the surface of Earth to travel in space or visit...

266

Exposure of human peripheral blood lymphocytes to electromagnetic fields associated with cellular phones leads to chromosomal instability  

Microsoft Academic Search

Whether exposure to radiation emitted from cellular phones poses a health hazard is at the focus of current debate. We have examined whether invitro exposure of human peripheral blood lymphocytes (PBL) to continuous 830 MHz electromagnetic fields causes losses and gains of chromosomes (aneuploidy), a major ''somatic mutation'' leading to genomic instability and thereby to cancer. PBL wereirradiatedatdifferentaverageabsorptionrates(SAR)intherangeof1.6-8.8W\\/kgfor72hrinan exposure system

Maya Mashevich; Dan Folkman; Amit Kesar; Alexander Barbul; Rafi Korenstein; Eli Jerby; Lydia Avivi

2003-01-01

267

Identification of Gene Expression Biomarkers for Predicting Radiation Exposure  

PubMed Central

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

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

2014-01-01

268

Cognitive deficits induced by 56Fe radiation exposure  

NASA Astrophysics Data System (ADS)

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

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

269

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

270

Near-infrared exposure changes cellular responses to ionizing radiation.  

PubMed

Near infrared (NIR) and X-rays are radiations from different sides of the wavelength spectrum but both are used during medical treatments, as they have severe impacts on cellular processes, including metabolism, gene expression, proliferation and survival. However, both radiations differ strictly in their consequences for exposed patients: NIR effects are generally supposed to be positive, mostly ascribed to a stimulation of metabolism, whereas X-ray leads to genetic instability, an increase of reactive oxygen species (ROS) and DNA damages and finally to cellular death by apoptosis in tumor cells. Since genomic stability after X-irradiation depends on the mitochondrial metabolism, which is well known to be regulated by NIR, we analyzed the impact of NIR on cellular responses of fibroblasts, retinal progenitor cells and keratinocytes to X-radiation. Our data show that previous exposure to naturally occurring doses of nonthermal NIR combined with clinically relevant X-ray doses leads to (1) increased genomic instability, indicated by elevated ratios of mitotic catastrophes, (2) increased ROS, (3) higher amounts of X-irradiated cells entering S-phase and (4) impaired DNA double-strand break repair. Taken together, our data show tremendous effects of NIR on cellular responses to X-rays, probably affecting the results of radiotherapy after NIR exposure during cancer treatment. PMID:22053955

Heselich, Anja; Frohns, Florian; Frohns, Antonia; Naumann, Steffen C; Layer, Paul G

2012-01-01

271

Susceptibility of human populations to environmental exposure to organic contaminants.  

PubMed

Environmental exposure to organic contaminants is a complex function of environmental conditions, food chain characteristics, and chemical properties. In this study the susceptibility of various human populations to environmental exposure to neutral organic contaminants was compared. An environmental fate model and a linked bioaccumulation model were parametrized to describe ecosystems in different climatic regions (temperate, arctic, tropical, and steppe). The human body burden resulting from constant emissions of hypothetical chemicals was estimated for each region. An exposure susceptibility index was defined as the body burden in the region of interest normalized to the burden of the same chemical in a reference human from the temperate region eating an average diet. For most persistent chemicals emitted to air, the Arctic had the highest susceptibility index (max 520). Susceptibility to exposure was largely determined by the food web properties. The properties of the physical environment only had a marked effect when air or water, not food, was the dominant source of human exposure. Shifting the mode of emission markedly changed the relative susceptibility of the ecosystems in some cases. The exposure arising from chemical use clearly varies between ecosystems, which makes an understanding of ecosystem susceptibility to exposure important for chemicals management. PMID:20704223

Undeman, Emma; Brown, Trevor N; Wania, Frank; McLachlan, Michael S

2010-08-15

272

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,...

273

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

274

Effect of UVC radiation on conformational restructuring of human serum albumin  

Microsoft Academic Search

The study of the influence of UVC-254nm radiation on spectroscopic and calorimetric properties of human serum albumin in aqueous solutions was conducted. This radiation did not only accelerate aging of albumin solutions but also caused the other qualitative changes. The dose dependent effect on conformational restructuring and thermal stability of albumin for exposure periods from 10 to 60min was shown.

Anna Michnik; Katarzyna Michalik; Zofia Drzazga

2008-01-01

275

Stable chromosome aberrations 25 years after severe accidental radiation exposure.  

PubMed

A thorough cytogenetic analysis using G-banding was performed on 100 peripheral blood lymphocytes from an individual who had been accidentally exposed to radiation more than 25 years previously. More than 60% of the analysed cells were found to possess one or more stable chromosome aberrations (e.g. reciprocal translocations). Chromosomes 1 and 11 were more involved in these aberrations than would be expected from the relative chromosome lengths. No identical stable aberrations were found, suggesting that, 25 years after near-lethal exposure, haemopoietic stem cells display substantial diversity. PMID:8310126

Maes, A; Hilali, A; Léonard, E D; Léonard, A; Verschaeve, L

1993-01-01

276

[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

277

Human performance during experimental formaldehyde exposure  

Microsoft Academic Search

Sixty-one subjects were exposed in a climate chamber for 5.5 hours to a controlled atmospheric environment. Formaldehyde vapors were added in concentrations of 0, 0.15, 0.40, or 1.20 mg\\/m³. The exposures were arranged in a 4 x 4, balanced latin square design, involving four days in each of four weeks. The subjects were all males. Of these 32 had occupational

B. Bach; O. F. Pedersen; L. Moelhave

1990-01-01

278

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

279

BIOCHEMICAL CHANGES IN HUMANS UPON EXPOSURE TO OZONE AND EXERCISE  

EPA Science Inventory

A total of 44 human subjects were exposed to 784 micrograms/cu.m.(0.4 ppm) ozone and 30 human subjects were exposed to air as controls. A four hour exposure was given on each of five consecutive days. Half of each group received a higher level of treadmill exercise than the other...

280

THE NATIONAL EXPOSURE RESEARCH LABORATORY'S COMPREHENSIVE HUMAN ACTIVITY DATABASE  

EPA Science Inventory

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

281

Human perception inspired exposure correction using total variation model  

Microsoft Academic Search

We present the framework for the exposure correction and back-light compensation using the bilateral logarithm total variation model based on human perception called HPEC. The method aims to emulate the way in which the human visual system discriminates original color in dim light or shadow region with rod, cone and light adaptation. The proposed method is effective for appropriate illumination

Heechul Han; Kwanghoon Sohn

2009-01-01

282

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. PMID:17938736

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

2007-01-01

283

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

PubMed Central

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

Ron, Elaine; Brenner, Alina

2013-01-01

284

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

PubMed

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

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

2010-05-01

285

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

286

Human lead exposure: Some recent research findings  

SciTech Connect

One of the practical problems facing industrial hygienists and safety managers in the lead industry is finding new ways to limit or reduce lead intake in order to protect workers from the deleterious effects of this metal. Exposure to lead generally takes place by inhalation of airborne particles and by ingestion. Airborne exposure is comparatively well understood and methods for the control of airborne lead have been developed and put into place in industrial facilities. Both for the general public and for workers, however, it is thought that a significant fraction of the total lead intake occurs by ingestion as opposed to inhalation. Furthermore, factors such as personal hygiene, hand washing, diet, cigarette smoking, alcohol consumption, use of medications, bone injury, existing disease, and others may also have positive or negative effects on lead absorption and blood lead levels. How these variables actually operate in practice for lead-exposed workers is unfortunately not very well understood. As scientific and medical knowledge increases, progress has been made in the understanding of some of the factors affecting blood lead levels. In this article, the author summarizes the findings of a few interesting recent reports that point the way toward future progress in this area.

Saryan, L.A.

1999-09-01

287

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

Code of Federal Regulations, 2012 CFR

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

2012-01-01

288

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

Code of Federal Regulations, 2013 CFR

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

2013-01-01

289

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

Code of Federal Regulations, 2012 CFR

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

2012-07-01

290

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

Code of Federal Regulations, 2011 CFR

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

2011-01-01

291

10 CFR 35.70 - Surveys of ambient radiation exposure rate.  

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

2014-01-01

292

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

Code of Federal Regulations, 2011 CFR

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

2011-07-01

293

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

294

HUMAN EXPOSURE MEASUREMENTS OF AIR TOXICS  

EPA Science Inventory

EPA's air toxics program is moving toward a risk-based focus. The framework for such a focus was laid out in the National Air Toxics Program: Integrated Urban Strategy which included the requirement for EPA to conduct a National-Scale Air Toxics Assessment (NATA) of human expos...

295

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...

296

Human mutagens: evidence from paternal exposure  

Microsoft Academic Search

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

Steven A. Narod; George R. Douglas; Earle R. Nestmann; David H. Blakey

1988-01-01

297

EVALUATION OF EXISTING TOTAL HUMAN EXPOSURE MODELS  

EPA Science Inventory

In the report, a special class of models is examined and several exiting formulations are compared. These models utilize pollutant concentration distributions and human time-activity patterns, methods of matching concentrations and activities, the number of pollutants which can b...

298

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

PubMed

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

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

2013-09-01

299

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

300

Solar UV radiation reduces the barrier function of human skin  

PubMed Central

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

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

2012-01-01

301

Effect of Deep Space Radiation on Human Hematopoietic Cells  

NASA Astrophysics Data System (ADS)

Astronaut flight crews on long-term missions in deep space will be exposed to a unique radiation environment as a result of exposure to galactic cosmic rays (GCR) and solar particle events (SPE). This environment consists predominantly of high energy protons, helium and high charge, high energy (HZE) atomic nuclei from iron predominantly, but all other elements as well. The effect of such particles, alone, or in combination, on human hematopoietic stem and progenitor cells (HSPC) has not been well studied but is clearly of interest since blood forming cells are known to be sensitive to radiation, and irreversible damage to these cells could quickly compromise a mission due to loss of marrow function. To better understand the effects of GCR and SPE on human stem/progenitor cell function, we have exposed partially purified CD34+ normal human marrow cells to protons, radioactive Fe, and Ti, alone, and in combination at varying doses up to 70cGy, and down to 1, 2, and 4 particle hits per nucleus. We then examined the effects of these radiations on HSPC function, as assessed by the ability to form CFU-GEMM, and LTCIC colonies in semi-solid culture medium. At the highest doses (50 and 70cGy), all radiation types tested significantly diminished the ability of CD34+ cells to form such colonies. The number of CFU-GEMM in irradiated samples was 70-90

Kalota, Anna; Bennett, Paula; Swider, Cezary R.; Sutherland, Betsy M.; Gewirtz, Alan M.

302

Conceptual framework for designing a national survey of human exposure.  

PubMed

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

Lioy, P J; Pellizzari, E

1995-01-01

303

Human exposure to radio base-station antennas in urban environment  

Microsoft Academic Search

In this paper, the human exposure to the electromagnetic field radiated by a radio base-station antenna operating around 900 MHz in an urban environment has been analyzed. A hybrid ray-tracing\\/finite-difference time-domain (FDTD) method has been used to evaluate the incident field and the power absorbed in an exposed subject in the presence of reflecting walls. The base-station antenna has been

Paolo Bernardi; Marta Cavagnaro; Stefano Pisa; Emanuele Piuzzi

2000-01-01

304

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

PubMed Central

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

2014-01-01

305

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

PubMed

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

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

2014-01-01

306

Dose-Response Relationships in Human Experimental Exposure to Solvents  

PubMed Central

Previous studies carried out in the field of experimental toxicology have shown evidence of biphasic dose-response relationships for different experimental models, endpoints and chemicals tested. As these studies excluded humans as the experimental model, we have examined the literature of the last three decades in order to verify data concerning human experimental exposure with the aim of highlighting possible biphasic dose-response relationships. The substances used for experimental exposures included hydrocarbons, esters, alcohols, ketones, ethers, glycoethers, halogenated hydrocarbons, and carbon sulphide; the absorption route was inhalation. We did not detect any biphasic dose-response relationship and, in the studies reviewed, our examination revealed major methodological limitations that prevented us making a more detailed examination of experimental data. We concluded that the experimental data available did not allow us to support evidence of biphasic dose-response relationships in human experimental exposure to the above-mentioned chemical substances. PMID:18648639

Iavicoli, Ivo; Carelli, Giovanni; Marinaccio, Alessandro

2006-01-01

307

Radiation exposure and breast cancer: lessons from Chernobyl.  

PubMed

The lessons learned from the Chernobyl disaster have become increasingly important after the second anniversary of the Fukushima, Japan nuclear accident. Historically, data from the Chernobyl reactor accident 27 years ago demonstrated a strong correlation with thyroid cancer, but data on the radiation effects of Chernobyl on breast cancer incidence have remained inconclusive. We reviewed the published literature on the effects of the Chernobyl disaster on breast cancer incidence, using Medline and Scopus from the time of the accident to December of 2010. Our findings indicate limited data and statistical flaws. Other confounding factors, such as discrepancies in data collection, make interpretation of the results from the published literature difficult. Re-analyzing the data reveals that the incidence of breast cancer in Chernobyl-disaster-exposed women could be higher than previously thought. We have learned little of the consequences of radiation exposure at Chernobyl except for its effects on thyroid cancer incidence. Marking the 27th year after the Chernobyl event, this report sheds light on a specific, crucial and understudied aspect of the results of radiation from a gruesome nuclear power plant disaster. PMID:23691737

Ogrodnik, Aleksandra; Hudon, Tyler W; Nadkarni, Prakash M; Chandawarkar, Rajiv Y

2013-04-01

308

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

309

Does cardiologist or radiographer-operated fluoroscopy and image acquisition influence optimization of patient radiation exposure during routine coronary angiography?  

Microsoft Academic Search

The operator of radiation exposure during coronary angiography varies between different centres. The purpose of this study was to explore whether radiation dose was lower during cardiologist- or radiographer-controlled radiation exposure and to determine if the grade of cardiologist performing angiography influenced radiation dose. Patients were randomly allocated either to cardiologist- or radiographer-controlled radiation exposure during coronary angiography. Screening time

W R ARTHUR; J DHAWAN; M S NORELL; A J HUNTER; A L CLARK

310

Compliation of summary statistics for radiation worker exposure for the 200 Areas: 1978--1993  

SciTech Connect

This document provides estimates of average annual radiation worker exposures for the 200 Areas of the Hanford Site for various facilities. The period of exposures extends from calendar year 1978 through 1993. These estimates were extracted from annual dosimetry reports.

Brown, R.C.

1994-10-06

311

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

312

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

313

THE FISHERMAN'S CARDS: HOW TO ADDRESS PAST AND FUTURE RADIATION EXPOSURES IN CLINCIAL DECISION-MAKING  

PubMed Central

This educational piece describes how to address patients’ past – and future potential – radiation exposures when making an imaging decision “now.” The BEIR committee has endorsed a linear no-threshold model to explain the relationship between radiation exposure and cancer risk. This model implies that past – and future potential – exposures should not impact current decisions. We present an analogy which deconstructs these counterintuitive conclusions and facilitates translation of key radiation-risk principles to practice. PMID:24450678

Eisenberg, Jonathan D.; Lewin, Sarah; Pandharipande, Pari V.

2014-01-01

314

Human exposure assessment: a graduate level course  

SciTech Connect

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

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

1991-07-01

315

Revolutionary Concepts of Radiation Shielding for Human Exploration of Space  

NASA Technical Reports Server (NTRS)

This Technical Memorandum covers revolutionary ideas for space radiation shielding that would mitigate mission costs while limiting human exposure, as studied in a workshop held at Marshall Space Flight Center at the request of NASA Headquarters. None of the revolutionary new ideas examined for the .rst time in this workshop showed clear promise. The workshop attendees felt that some previously examined concepts were de.nitely useful and should be pursued. The workshop attendees also concluded that several of the new concepts warranted further investigation to clarify their value.

Adams, J. H., Jr.; Hathaway, D. H.; Grugel, R. N.; Watts, J. W.; Parnell, T. A.; Gregory, J. C.; Winglee, R. M.

2005-01-01

316

Radiation exposure to interventional radiologists during manual-injection digital subtraction angiography  

Microsoft Academic Search

Purpose: We investigated the relationship between the amount of radiation exposure to the operator during tableside manual-injection\\u000a angiographic procedures including digital subtraction angiography (DSA) and the operator’s position, as well as a simple means\\u000a to decrease radiation exposure.\\u000a \\u000a \\u000a Methods: Measurement of radiation exposure was carried out with thermoluminescent dosimeters (TLDs) in nine abdominal angiographies.\\u000a In the first study, radiation exposure

Nobushige Hayashi; Toyohiko Sakai; Manabu Kitagawa; Rika Inagaki; Toru Yamamoto; Tetsuya Fukushima; Yasushi Ishii

1998-01-01

317

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

SciTech Connect

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 thyroid disorders among hairy cell leukemia patients was also unusually high was interpreted as further indirect evidence of excessive radiation exposure. It appears that radiation exposure may be an important contributing factor in the development of some cases of hairy cell leukemia.

Stewart, D.J.; Keating, M.J.

1980-10-01

318

Radiation exposure and the risk of pediatric thyroid cancer.  

PubMed

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

Miyakawa, Megumi

2014-07-01

319

Changes in Liver Metabolic Gene Expression after Radiation Exposure  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

320

Occupational Radiation Exposure Analysis of US ITER DCLL TBM  

SciTech Connect

This report documents an Occupational Radiation Exposure (ORE) analysis that was performed for the US International Thermonuclear Experimental Reactor (ITER) Dual Coolant Lead Lithium (DCLL) Test Blanket Module (TBM). This analysis was performed with the QADMOD dose code for anticipated maintenance activities for this TBM concept and its ancillary systems. The QADMOD code was used to model the PbLi cooling loop of this TBM concept by specifying gamma ray source terms that simulated radioactive material within the piping, valves, heat exchanger, permeator, pump, drain tank, and cold trap of this cooling system. Estimates of the maintenance tasks that will have to be performed and the time required to perform these tasks where developed based on either expert opinion or on industrial maintenance experience for similar technologies. This report details the modeling activity and the calculated doses for the maintenance activities envisioned for the US DCLL TBM.

Merrill, Brad J; Cadwallader, Lee C; Dagher, Mohamad

2007-08-01

321

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

EPA Science Inventory

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

322

Integrating population dynamics into mapping human exposure to seismic hazard  

NASA Astrophysics Data System (ADS)

Disaster risk is not fully characterized without taking into account vulnerability and population exposure. Assessment of earthquake risk in urban areas would benefit from considering the variation of population distribution at more detailed spatial and temporal scales, and from a more explicit integration of this improved demographic data with existing seismic hazard maps. In the present work, "intelligent" dasymetric mapping is used to model population dynamics at high spatial resolution in order to benefit the analysis of spatio-temporal exposure to earthquake hazard in a metropolitan area. These night- and daytime-specific population densities are then classified and combined with seismic intensity levels to derive new spatially-explicit four-class-composite maps of human exposure. The presented approach enables a more thorough assessment of population exposure to earthquake hazard. Results show that there are significantly more people potentially at risk in the daytime period, demonstrating the shifting nature of population exposure in the daily cycle and the need to move beyond conventional residence-based demographic data sources to improve risk analyses. The proposed fine-scale maps of human exposure to seismic intensity are mainly aimed at benefiting visualization and communication of earthquake risk, but can be valuable in all phases of the disaster management process where knowledge of population densities is relevant for decision-making.

Freire, S.; Aubrecht, C.

2012-11-01

323

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

324

Biodosimetry of ionizing radiation by selective painting of prematurely condensed chromosomes in human lymphocytes  

NASA Technical Reports Server (NTRS)

Painting of interphase chromosomes can be useful for biodosimetric purposes in particular cases such as radiation therapy, accidental exposure to very high radiation doses and exposure to densely ionizing radiation, for example during space missions. Biodosimetry of charged-particle radiation is analyzed in the present paper. Target cells were human peripheral blood lymphocytes irradiated in vitro with gamma rays, protons and iron ions. After exposure, lymphocytes were incubated for different times to allow repair of radiation-induced damage and then fused to mitotic hamster cells to promote premature condensation in the interphase chromosomes. Chromosome spreads were then hybridized with whole-chromosome DNA probes labeled with fluorescent stains. Dose-response curves for the induction of chromatin fragments shortly after exposure, as well as the kinetics of rejoining and misrejoining, were not markedly dependent on linear energy transfer. However, after exposure to heavy ions, more aberrations were scored in the interphase cells after incubation for repair than in metaphase samples harvested at the first postirradiation mitosis. On the other hand, no significant differences were observed in the two samples after exposure to sparsely ionizing radiation. These results suggest that interphase chromosome painting can be a useful tool for biodosimetry of particle radiation.

Durante, M.; George, K.; Yang, T. C.

1997-01-01

325

Satellite nighttime lights reveal increasing human exposure to floods worldwide  

NASA Astrophysics Data System (ADS)

River floods claim thousands of lives every year, but effective and high-resolution methods to map human exposure to floods at the global scale are still lacking. We use satellite nightlight data to prove that nocturnal lights close to rivers are consistently related to flood damages. We correlate global data of economic losses caused by flooding events with nighttime lights and find that increasing nightlights are associated to flood damage intensification. Then, we analyze the temporal evolution of nightlights along the river network all over the world from 1992 to 2012 and obtain a global map of nightlight trends, which we associate with increasing human exposure to floods, at 1 km2 resolution. An enhancement of exposure to floods worldwide, particularly in Africa and Asia, is revealed, which may exacerbate the projected effects of climate change on flood-related losses and therefore argues for the development of valuable flood preparedness and mitigation strategies.

Ceola, Serena; Laio, Francesco; Montanari, Alberto

2014-10-01

326

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...

327

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...

328

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...

329

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...

330

HUMAN EXPOSURE TO MUTAGENS FROM INDOOR COMBUSTION SOURCES  

EPA Science Inventory

The authors have measured human exposure to mutagens, using indoor medium-volume samplers and personal samplers, in targeted field studies of homes in the U.S. The combustion sources included in these studies were woodstoves, fireplaces, gas appliances, cooking, and tobacco smoki...

331

Human exposure to electromagnetic fields from mobile phones  

Microsoft Academic Search

A mobile phone can emit a few watts of power in the vicinity of the human head. The paper reviews the different types of mobile phones, the related exposures, the assumed biological effects as well as the health safety recommendations and test methods. An isotropic E-field probe suitable for phantom measurement is also described

Bkla Szentpali

1999-01-01

332

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

SciTech Connect

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

Fabrikant, J.I.

1982-04-01

333

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

PubMed

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

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

2013-11-01

334

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

PubMed Central

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

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

2013-01-01

335

Intensity/frequency indicator for detection in space: the high values of the incident solar or laser optical radiation in comparison with the appropriate maximum permissible exposure.  

PubMed

The solar or laser optical radiation impact to humans in space depends on the intensity, on the exposure type (direct or indirect) & duration and on the matching of radiation wavelength to tissue characteristics. The main protection factor in space is the application of exposure limits. This paper describes the main biological optical interaction parameters, the optical exposure hazards and the development of a small active lightweight indicator, with output beeper rate depended to the ratio of optical irradiance/exposure limit. The indicator may be used as warning element on the side of helmets, goggles, spectacles, etc, with low power consumption. Electronically the indicator is an intensity/frequency converter, based on the value of the ratio of exposure/exposure limits, with audio & light beepers like the indication output of the ionizing (radioactive) radiation monitors. PMID:11669120

Tsitomeneas, S; Petropoulos, B

2001-01-01

336

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 ...

337

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

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

338

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

PubMed Central

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

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

2014-01-01

339

Ionizing Radiation and Humans â The Basics  

NSDL National Science Digital Library

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

2012-06-26

340

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

PubMed

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

Haymerle, A; Fahlman, A; Walzer, C

2010-08-28

341

ALTERNATIVE EXPOSURE MEASUREMENT DESIGNS TO IMPROVE EPIDEMIOLOGICAL STUDY DESIGNS: USE OF HUMAN EXPOSURE STUDY DATA TO IDENTIFY EXPOSURE QUESTIONS FOR USE IN THE NCS  

EPA Science Inventory

The National Human Exposure Assessment Survey in Maryland (NHEXAS-MD) was a longitudinal study of multimedia exposure to metals, pesticides, and polycyclic aromatic compounds (PAHs). Measurements were made and questionnaires were concurrently administered to identify sources o...

342

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

343

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

PubMed

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

Guy, A W

1987-12-01

344

Effect of controlled ozone exposure on human lymphocyte function  

SciTech Connect

The effects of ozone (O/sub 3/) on cell-mediated immunity were studied in 16 human subjects exposed to 1176 ..mu..g/m/sup 3/ O/sub 3/ (0.6 ppM) for 2 h in an environmentally controlled exposure chamber. Venous blood samples were taken before and immediately after controlled air and O/sub 3/ exposures, as well as at 72 h, 2 and 4 weeks, and at one random time at least 1 month after treatment. The relative frequency of T lymphocytes in blood and the in vitro blastogenic response of lymphocytes to phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM), and Candida albicans were determined. During the course of the experiment, no statistically significant changes were observed in the number of T lymphocytes that form spontaneous rosettes with sheep erythrocytes. The response of T lymphocytes to PHA was significantly reduced (P < 0.05) in samples taken at 2 and 4 weeks, following O/sub 3/ exposure. Normal response to PHA was observed at 2 months post-O/sub 3/ exposure. No statistically significant changes in lymphocyte responses to Con A, PWM, or Candida were seen. These results show that one 2 h exposure of humans to 0.6 ppM O/sub 3/ may lead to a transient suppression of the PHA-stimulated blastogenic transformation of peripheral blood lymphocytes. The data indicate that the blastogenic response to PHA of human lymphocytes is exquisitely sensitive to O/sub 3/ exposure and could serve as a bioassay for evaluating subtle changes in cellular immunity induced by O/sub 3/ and possibly other pollutants.

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

1981-04-01

345

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

Code of Federal Regulations, 2010 CFR

... 2010-01-01 false Records of surveys for ambient radiation exposure rate...MATERIAL Records § 35.2070 Records of surveys for ambient radiation exposure rate. A licensee shall retain a record of each survey required by § 35.70 for 3 years....

2010-01-01

346

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

Code of Federal Regulations, 2012 CFR

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

2012-01-01

347

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

Code of Federal Regulations, 2011 CFR

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

2011-01-01

348

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

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

2014-01-01

349

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

Code of Federal Regulations, 2013 CFR

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

2013-01-01

350

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

351

Dose and dose rate measurements for radiation exposure scenarios in nuclear medicine  

Microsoft Academic Search

Radiation exposure for the staff in nuclear medicine departments is inevitable. After application of radiopharmaceuticals the patient himself becomes a radioactive source. Consequently, we need detailed information on the extent of radiation exposure for each single person dealing with radioactive sources and patients in nuclear medicine.In this work, dose rates of a variety of radioactive sources – radiopharmaceuticals and patients

Ferdinand Sudbrock; Klara Uhrhan; Arndt Rimpler; Harald Schicha

2011-01-01

352

Linking the human response to unplanned radiation and treatment to the nonhuman primate response to controlled radiation and treatment.  

PubMed

A key difficulty in developing countermeasures against radiation-induced health impairments is the clear lack of controlled clinical studies, due to the relatively low number of radiation victims worldwide. Instead, established and accepted animal models, as well as the recommendations of national and international expert panels and committees, are the main sources of information. Therefore, the development of countermeasures requires comparison of data from many sources and accumulation of information consistent with the U. S. Food and Drug Administration's "Animal Rule." A new approach is the comparative analysis of human data from the SEARCH (System for Evaluation and Archiving of Radiation Accidents based on Case Histories) database and data from nonhuman primate (NHP) animal model studies. The SEARCH database contains 824 clinical cases from 81 radiation accidents in 19 countries. This exceptional collection of clinical data from accidentally radiation-exposed persons is analyzed regarding clinical signs and symptoms of radiation-induced health impairments. To analyze the time course of radiation syndromes, clinical parameters common to the SEARCH and NHP databases have to be assigned into comparable categories of clinical severity for each species. The goal is to establish a method for comparison of human and NHP data, validate the NHP data as a surrogate for human efficacy/clinical studies, and open a way for the extraction of diagnostic and treatment methods for humans after radiation exposure according to relevant regulations. PMID:24276556

Dörr, Harald; Lamkowski, Andreas; Graessle, Dieter H; Bennett, Alexander; Shapiro, Alla; Farese, Ann M; Garofalo, Michael; MacVittie, Thomas J; Meineke, Viktor

2014-01-01

353

Induction and rejoining of DNA double-strand breaks in normal human skin fibroblasts after exposure to radiation of different linear energy transfer: possible roles of track structure and chromatin organization.  

PubMed

DNA double-strand breaks are nonrandomly induced by high-LET radiation. Differences in the induction and rejoining of DSBs after irradiation with ions having different LET were detected by fragment analysis. The data obtained indicate that the track structure of the traversing particle and its interaction with the different chromatin structures of the cellular DNA influence the yield as well as the distribution of the induced damage. The induction and rejoining of clustered DSBs induced by the same nitrogen ion fluence at LETs of 80-225 keV/microm were investigated by a detailed analysis of the DNA fragmentation patterns in normal human fibroblasts. The DSBs in the cells were allowed to rejoin during incubations for 0-20 h. Two separate pulsed-field gel electrophoresis protocols were used, optimized for separation of fragments in the size ranges 1-6 Mbp and 5 kbp-1.5 Mbp. A strong influence of LET on the level of DSB induction was evident. The DSB yield increased from 4.5 +/- 0.2 to 10.0 +/- 0.3 DSBs per particle traversal through the cell nucleus when LET increased from 80 to 225 keV/microm. Further, the size distribution of the DNA fragments showed a significant dependence on radiation quality, with an excess of fragments at 50-200 kbp and around 1 Mbp. Differences in repair kinetics were also evident, with slower rejoining for increasing LET, and the initial nonrandom fragment distributions were still present after 1 h of repair. PMID:11352764

Höglund, H; Stenerlöw, B

2001-06-01

354

Nuclear-weapon-effect research at PSR (Pacific-Sierra Research Corporation) - 1983. Volume 10. Symptomatology of acute radiation effects in humans after exposure to doses of 75 to 4500 rads (cGy) free-in-air. Final technical report, 27 October 1982-30 November 1983  

SciTech Connect

This report distills from available data descriptions of typical human symptoms in reaction to prompt ionizing radiation in the dose range 75 to 4500 rads (cGy) free-in-air. The descriptions correlate symptoms with dose and time over the acute post-exposure period of six weeks. Their purpose is to provide an empirical base for estimating combat troop performance after a nuclear weapon attack. The dose range of interest is subdivided into eight subranges associated with important pathophysiological events. For each subrange, the signs and symptoms manifested by an exposed population are estimated--symptom onset, severity, duration, and incidence. The early or prodromal phase of radiation sickness begins about 2 to 4 hrs after doses of 300 to 530 rads (cGy). Onset time diminishes with dose, occurring within minutes of exposure to 4500 rads (cGy). Characteristic prodromal symptoms are nausea, vomiting, anorexia, and diarrhea. The prodromal phase lasts from several days to a matter of hours, depending on dose. Symptoms of the hemopoietic syndrome are bleeding, fever, infection, and ulceration. Symptoms of the gastrointestinal syndrome are fluid loss, electrolyte imbalance, severe diarrhea, and septicemia.

Baum, S.J.; Young, R.W.; Anno, G.H.; Withers, H.R.

1984-08-31

355

Naphthalene distributions and human exposure in Southern California  

NASA Astrophysics Data System (ADS)

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

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

356

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

357

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

358

Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L  

Microsoft Academic Search

Widespread use of radiofrequency radiation emitting devices increased the exposure to electromagnetic fields (EMFs) from 300 MHz to 300 GHz. Various biological effects of exposure to these fields have been documented so far, but very little work has been carried out on plants. The aim of the present work was to investigate the physiological responses of the plant Lemna minor after exposure

Mirta Tkalec; Krešimir Malari?; Branka Pevalek-Kozlina

2007-01-01

359

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...

360

Human Physiological Responses to Acute and Chronic Cold Exposure  

NASA Technical Reports Server (NTRS)

When inadequately protected humans are exposed to acute cold, excessive body heat is lost to the environment and unless heat production is increased and heat loss attenuated, body temperature will decrease. The primary physiological responses to counter the reduction in body temperature include marked cutaneous vasoconstriction and increased metabolism. These responses, and the hazards associated with such exposure, are mediated by a number of factors which contribute to heat production and loss. These include the severity and duration of the cold stimulus; exercise intensity; the magnitude of the metabolic response; and individual characteristics such as body composition, age, and gender. Chronic exposure to a cold environment, both natural and artificial, results in physiological alterations leading to adaptation. Three quite different, but not necessarily exclusive, patterns of human cold adaptation have been reported: metabolic, hypothermic, and insulative. Cold adaptation has also been associated with an habituation response, in which there is a desensitization, or damping, of the normal response to a cold stress. This review provides a comprehensive analysis of the human physiological and pathological responses to cold exposure. Particular attention is directed to the factors contributing to heat production and heat loss during acute cold stress, and the ability of humans to adapt to cold environments.

Stocks, Jodie M.; Taylor, Nigel A. S.; Tipton, Michael J.; Greenleaf, John E.

2001-01-01

361

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

362

Modeling hematopoietic system response caused by chronic exposure to ionizing radiation  

PubMed Central

A new model of the hematopoietic system response in humans chronically exposed to ionizing radiation describes the dynamics of the hematopoietic stem cell compartment as well as the dynamics of each of the four blood cell types (lymphocytes, neutrophiles, erythrocytes, and platelets). The required model parameters were estimated based on available results of human and experimental animal studies. They include the steady-state number of hematopoietic stem cells and peripheral blood cell lines in an unexposed organism, amplification parameters for each blood line, parameters describing proliferation and apoptosis, parameters of feedback functions regulating the steady-state numbers, and characteristics of radiosensitivity related to cell death and non-lethal cell damage. The model predictions were tested using data on hematological measurements (e.g., blood counts) performed in 1950–1956 in the Techa River residents chronically exposed to ionizing radiation since 1949. The suggested model of hematopoiesis is capable of describing experimental findings in the Techa River Cohort, including: i) slopes of the dose-effect curves reflecting the inhibition of hematopoiesis due to chronic ionizing radiation, ii) delay in effect of chronic exposure and accumulated character of the effect, and iii) dose-rate patterns for different cytopenic states (e.g., leukopenia, thrombocytopenia). PMID:21259022

Akushevich, Igor V.; Veremeyeva, Galina A.; Dimov, Georgy P.; Ukraintseva, Svetlana V.; Arbeev, Konstantin G.; Akleyev, Alexander V.; Yashin, Anatoly I.

2013-01-01

363

Radiation exposure differentially affects songbird 8-hydroxy-2'-deoxyguanosine plasma profiles: ionizing radiation damage response in songbirds.  

PubMed

The importance of understanding the effects of radiation exposure on wildlife is a critical responsibility of our stewardship of nuclear energy production. We tested the hypothesis that songbirds respond to exogenous radiation exposure with changes in plasma 8-hydroxy-2'-deoxyguanosine (8-OH-dG). We exposed two species of songbirds, house sparrows (Passer domesticus; n = 12) and song sparrows (Melospiza melodia; n = 12), to one of four acute whole-body radiation treatments: 75, 150, 300, or 600 mGy. We measured DNA damage by proxy as 8-OH-dG levels in the plasma at 0 hr (baseline), 36 hr, and 7 days post radiation. For both species, at all radiation treatments, 8-OH-dG levels increased significantly 36 hr following radiation exposure. However, songbird species differed significantly in response to treatment across time and between treatment groups. Song sparrows showed no significant changes in 8-OH-dG levels between 36 hr and Day 7. In contrast, house sparrows exposed to 300 and 600 mGy had significantly increased 8-OH-dG levels at Day 7 compared with 36 hr. This study demonstrates that in a controlled experiment, in isolation from other sources of genotoxicity, radiation exposure significantly affects songbirds. Our results suggest future research examining the effects of radiation on songbirds must consider using multiple species to assess the biological effects of radiation, as different species can show strikingly different responses to radiation dosage across time. PMID:21809389

Luloff, Thomas W; Wishart, Andrea E; Addison, Sean M F; Macdougall-Shackleton, Scott A; Hill, Kathleen A

2011-10-01

364

Human exposure to radiofrequency electromagnetic fields. Final rule.  

PubMed

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

2013-06-01

365

Radiation exposure to the patient and operating room personnel during percutaneous nephrolithotomy  

Microsoft Academic Search

Introduction: The increased use of fluoroscopy during percutaneous nephrolithotomy (PCNL) places the urologist and operating room personnel\\u000a at an occupational risk for measurable radiation exposure. We evaluated the degree of radiation exposure received by the patient\\u000a and operating room personnel at our endourology facility during PCNL. Patients and method: The incident radiation dose to the patient and the urologist during

Geeta Kumari; Pratik Kumar; Pankaj Wadhwa; Monish Aron; Narmada P. Gupta; Prem N. Dogra

2006-01-01

366

Measurement of radiation exposure of astronauts by radiochemical techniques  

NASA Technical Reports Server (NTRS)

Only two of the fecal specimens collected inflight during the Apollo 15 mission were returned for analysis. Difficulty in obtaining reasonably accurate radiation dose estimates based on the cosmogenic radionuclide content of the specimens was encountered due to the limited sampling. The concentrations of Na-22, K-40, Cr-51, Fe-59, and Cs-137 are reported. The concentrations of 24 major, minor, and trace elements in these two specimens were determined. Most concentrations are typical of those observed previously. Major exceptions are extremely low values for selenium and extraordinarily high values for rare earth elements. The net Po-210 activities in the Apollo 11 and 12 Solar Wind Composition foils and in the Apollo 8 and 12 spacecraft reflective coatings due to lunar exposure have been determined. Equilibrium concentrations of 0.082 + or - 0.012 disintegrations /sq cm sec of Rn-222 in the lunar atmosphere and 0.0238 + or - 0.0035 disintegrations /sq cm sec of Po-210 on the lunar surface have been calculated for Oceanus Procellarum.

Brodzinski, R. L.

1972-01-01

367

Radiation exposure in body computed tomography examinations of trauma patients  

NASA Astrophysics Data System (ADS)

Multi-slice CT provides an efficient imaging modality for trauma imaging. The purpose of this study was to provide absorbed and effective dose data from CT taking into account the patient size and compare such doses with the standard CT dose quantities based on standard geometry. The CT examination data from abdominal and thoracic scan series were collected from 36 trauma patients. The CTDIvol, DLPw and effective dose were determined, and the influence of patient size was applied as a correction factor to calculated doses. The patient size was estimated from the patient weight as the effective radius based on the analysis from the axial images of abdominal and thoracic regions. The calculated mean CTDIvol, DLPw and effective dose were 15.2 mGy, 431 mGy cm and 6.5 mSv for the thorax scan, and 18.5 mGy, 893 mGy cm and 14.8 mSv for the abdomen scan, respectively. The doses in the thorax and abdomen scans taking the patient size into account were 34% and 9% larger than the standard dose quantities, respectively. The use of patient size in dose estimation is recommended in order to provide realistic data for evaluation of the radiation exposure in CT, especially for paediatric patients and smaller adults.

Kortesniemi, M.; Kiljunen, T.; Kangasmäki, A.

2006-06-01

368

Mortality and occupational exposure to radiation: first analysis of the National Registry for Radiation Workers.  

PubMed Central

OBJECTIVE--To study cause specific mortality of radiation workers with particular reference to associations between fatal neoplasms and level of exposure to radiation. DESIGN--Cohort study. SETTING--United Kingdom. SUBJECTS--95,217 radiation workers at major sites of the nuclear industry. MAIN OUTCOME MEASURE--Cause of death. RESULTS--Most standardised mortality ratios were below 100: 83 unlagged, 85 with a 10 year lag for all causes; 84 unlagged, 86 lagged for all cancers; and 80 for all known other causes, indicating a "healthy worker effect." The deficit of lung cancer (75 unlagged, 76 lagged) was significant at the 0.1% level. Standardised mortality ratios were significantly raised (214 unlagged, 303 lagged) for thyroid cancer, but there was no evidence for any trend with external recorded radiation dose. Dose of external radiation and mortality from all cancers were weakly correlated (p = 0.10), and multiple myeloma was more strongly correlated (p = 0.06); for leukaemia, excluding chronic lymphatic, the trend was significant (p = 0.03; all tests one tailed). The central estimates of lifetime risk derived from these data were 10.0% per Sv (90% confidence interval less than 0 to 24%) for all cancers and 0.76% per Sv (0.07 to 2.4%) for leukaemia (excluding chronic lymphatic leukaemia). These are, respectively, 2.5 times and 1.9 times the risk estimates recommended by the International Commission on Radiological Protection, but 90% confidence intervals are large and the commission's risk factors fall well within the range. The positive trend with dose for all cancers, from which the risk estimate was derived, was not significant. The positive association between leukaemia (except chronic lymphatic leukaemia) was significant and robust in subsidiary analyses. This study showed no association between radiation exposure and prostatic cancer. CONCLUSION--There is evidence for an association between radiation exposure and mortality from cancer, in particular leukaemia (excluding chronic lymphatic leukaemia) and multiple myeloma, although mortality from these diseases in the study population overall was below that in the general population. The central estimates of risk from this study lie above the most recent estimates of the International Commission on Radiological Protection for leukaemia (excluding chronic lymphatic leukaemia) and for all malignancies. However, the commission's risk estimates are well within the 90% confidence intervals from this study. Analysis of combined cohorts of radiation workers in the United States indicated lower risk estimates than the commission recommends, and when the American data are combined with our analysis the overall risks are close to those estimated by the commission. This first analysis of the National Registry for Radiation Workers does not provide sufficient evidence to justify a revision in risk estimates for radiological protection purposes. PMID:1739796

Kendall, G. M.; Muirhead, C. R.; MacGibbon, B. H.; O'Hagan, J. A.; Conquest, A. J.; Goodill, A. A.; Butland, B. K.; Fell, T. P.; Jackson, D. A.; Webb, M. A.

1992-01-01

369

Transgenerational effects of radiation and chemicals in mice and humans.  

PubMed

Parental exposure of mice to radiation and chemicals causes a variety of adverse effects (e.g., tumors, congenital malformations and embryonic deaths) in the progeny and the tumor-susceptibility phenotype is transmissible beyond the first post-radiation generation. The induced rates of tumors were 100-fold higher than those known for mouse specific locus mutations. There were clear strain differences in the types of naturally-occurring and induced tumors and most of the latter were malignant. Another important finding was that germ-line exposure elicited very weak tumorigenic responses, but caused persistent hypersensitivity in the offspring for the subsequent development of cancer by the postnatal environment. Activations of oncogenes, ras, mos, abl, etc. and mutations in tumor suppressor genes such as p53 were also detected in specific tumors in cancer-prone descendants. However, the majority of tumors observed in the progeny were those commonly observed in the strains that were used and oncogene activations were rarely observed in these tumors. It can be hypothesized that genetic instability modifies tumor occurrence in a transgenerational manner, but so far no links could be established between chromosomal and molecular changes and transmissible tumor risks. Our data are consistent with the hypothesis that cumulative changes in many normal but cancer-related genes affecting immunological, biochemical and physiological functions may slightly elevate the incidence of tumors or fasten the tumor development. This hypothesis is supported by our GeneChip analyses which showed suppression and/or over-expression of many such genes in the offspring of mice exposed to radiation. In humans, a higher risk of leukemia and birth defects has been reported in the children of fathers who had been exposed to radionuclides in the nuclear reprocessing plants and to diagnostic radiation. These findings have not been supported in the children of atomic bomb survivors in Hiroshima and Nagasaki, who were exposed to higher doses of atomic radiation. However, it will be important to follow the human subjects, especially for adult type cancers and chronic diseases throughout their lives to determine whether the mouse studies can predict human responses. PMID:17019056

Nomura, Taisei

2006-01-01

370

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

PubMed

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

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

2011-06-01

371

47 CFR 1.1310 - Radiofrequency radiation exposure limits.  

Code of Federal Regulations, 2013 CFR

...Exposure to Radiofrequency Electromagnetic Fields,” and in supplements to...Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz...Criteria for Radiofrequency Electromagnetic Fields,” NCRP Report No....

2013-10-01

372

47 CFR 1.1310 - Radiofrequency radiation exposure limits.  

Code of Federal Regulations, 2010 CFR

...Criteria for Radiofrequency Electromagnetic Fields,” NCRP Report No. 86...MHz, exposure limits for field strength and power density...Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz,”...

2010-10-01

373

47 CFR 1.1310 - Radiofrequency radiation exposure limits.  

Code of Federal Regulations, 2011 CFR

...Criteria for Radiofrequency Electromagnetic Fields,” NCRP Report No. 86...MHz, exposure limits for field strength and power density...Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz,”...

2011-10-01

374

47 CFR 1.1310 - Radiofrequency radiation exposure limits.  

Code of Federal Regulations, 2012 CFR

...Criteria for Radiofrequency Electromagnetic Fields,” NCRP Report No. 86...MHz, exposure limits for field strength and power density...Exposure to Radio Frequency Electromagnetic Fields, 3 kHz to 300 GHz,”...

2012-10-01

375

Progress in Space Weather Modeling and Observations Needed to Improve the Operational NAIRAS Model Aircraft Radiation Exposure Predictions  

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. 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. During the development of the NAIRAS model, new science questions were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. Addressing these science questions require improvements in both space weather modeling and observations. The focus of this talk is to present these science questions, the proposed methodologies for addressing these science questions, and the anticipated improvements to the operational predictions of atmospheric radiation exposure. The overarching goal of this work is to provide a decision support tool for the aviation industry that will enable an optimal balance to be achieved between minimizing health risks to passengers and aircrew while simultaneously minimizing costs to the airline companies.

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

2011-12-01

376

FINAL REPORT. HUMAN GENETIC MARKER FOR RESISTANCE TO RADIATIONS AND CHEMICALS  

EPA Science Inventory

The purpose of this project has been to characterize the human HRAD9 gene and evaluate its potential as a biomarker to predict susceptibility to the deleterious health effects potentially caused by exposure to radiations or chemicals present at DOE hazardous waste cleanup sites. ...

377

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

PubMed

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

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

2011-01-01

378

Radiation Exposures Associated with Shipments of Foreign Research Reactor Spent Nuclear Fuel  

SciTech Connect

Experience has shown that the analyses of marine transport of spent fuel in the Environmental Impact Statement (EIS) were conservative. It is anticipated that for most shipments. The external dose rate for the loaded transportation cask will be more in line with recent shipments. At the radiation levels associated with these shipments, we would not expect any personnel to exceed radiation exposure limits for the public. Package dose rates usually well below the regulatory limits and personnel work practices following ALARA principles are keeping human exposures to minimal levels. However, the potential for Mure shipments with external dose rates closer to the exclusive-use regulatory limit suggests that DOE should continue to provide a means to assure that individual crew members do not receive doses in excess of the public dose limits. As a minimum, the program will monitor cask dose rates and continue to implement administrative procedures that will maintain records of the dose rates associated with each shipment, the vessel used, and the crew list for the vessel. DOE will continue to include a clause in the contract for shipment of the foreign research reactor spent nuclear fuel requiring that the Mitigation Action Plan be followed.

MASSEY,CHARLES D.; MESSICK,C.E.; MUSTIN,T.

1999-11-01

379

Conceptual basis for evaluating risk from low-level radiation exposure  

SciTech Connect

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

Bond, V.P.

1981-01-01

380

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

PubMed

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

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

2014-12-01

381

Zinc- or cadmium-pre-induced metallothionein protects human central nervous system cells and astrocytes from radiation-induced apoptosis.  

PubMed

We have shown the protection of human central nervous system (CNS) cultures by zinc (Zn) or cadmium (Cd)-pre-induced metallothionein (MT) synthesis from radiation-induced cytotoxicity (lactate dehydrogenase (LDH) release and neuronal dendritic injury). The present study is to further define the types of cell death induced by different dose levels of radiation and investigate the effect of MT induction (by Zn or Cd) on radiation-induced apoptosis in primary human CNS and astrocyte cultures. Apoptosis was detected by fragmented DNA electrophoresis, TUNEL technique, and propidium iodide staining. Expression of MT protein was examined by immunofluorescent staining. Results showed that exposure of primary human CNS cultures to 15 and 30 Gy gamma-radiation predominantly induced apoptotic cell death, while exposure to 60 Gy gamma-radiation predominantly induced necrotic cell death. Normal primary human CNS cultures showed weak MT staining, while primary human CNS cultures exposed to Zn or Cd showed intense MT staining. The induced apoptotic cell death by exposure to 30 Gy gamma-radiation increased to a maximum level at 12 and 24 h, and was reduced significantly by Zn or Cd pre-induced MT. Using primary human astrocytes, the induction of MT protein by Zn or Cd was further confirmed. The enhanced MT expression also afforded a significant protection from 30 Gy gamma-ray-induced apoptosis in the primary human astrocytes. These results suggest that MT protected human CNS cells from apoptosis following ionizing radiation, probably through its antioxidant property. PMID:14687759

Cai, Lu; Iskander, Sammy; Cherian, M George; Hammond, Robert R

2004-02-01

382

Targeted and Non-Targeted Induction of Chromosomal Rearrangements After Exposure to Ionizing Radiation  

SciTech Connect

Analysis of chromosomal rearrangements has been used for many years to determine whether an individual has been exposed to ionizing radiation, and to provide a reliable estimate of the exposure dose (reviewed in Cornforth 1998)). A rich and well-documented literature indicates that cytogenetic analysis can be used to determine exposures to radiation doses as low as 15 – 20cGy, and thus provides the most sensitive and reliable assay for radiation exposure. Implicit in interpreting these types of analysis is that the induced cytogenetic alterations result from the deposition of energy by ionizing radiation and subsequent cellular responses. Specifically, radiation exposure leads to DNA damage, namely single and double stranded DNA breaks, DNA – DNA and DNA – protein crosslinks, and DNA base damages (Ward 1988). The cell then responds to this damage by initiating changes in gene expression, inducing cell cycle checkpoint control strategies and signal transduction pathways, and activating DNA repair processes.

Morgan, William F.; Sowa, Marianne B.

2007-07-10

383

Canadian Cardiovascular Society position statement on radiation exposure from cardiac imaging and interventional procedures.  

PubMed

Exposure to ionizing radiation is a consequence of many diagnostic and interventional cardiac procedures. Radiation exposure can result in detrimental health effects because of deterministic (eg, skin reaction) and stochastic effects (eg, cancer). However, with the levels experienced during cardiac procedures these risks can be difficult to quantify. Healthcare providers and patients might not fully appreciate radiation-related risks. Though in many cases radiation exposure cannot be avoided, a practice of minimizing exposures to levels "as low as reasonably achievable" (ALARA principle) without compromising the utility of the procedure is encouraged. The purpose of this document is to inform health care providers on the key concepts related to radiation risk from common cardiac procedures and provide specific recommendations on ensuring quality of care. PMID:24035289

Natarajan, Madhu K; Paul, Narinder; Mercuri, Mathew; Waller, Edward J; Leipsic, Jonathon; Traboulsi, Mouhieddin; Banijamali, Hamid S; Benson, Lee; Sheth, Tej N; Simpson, Christopher S; Brydie, Allan; Love, Michael P; Gallo, Richard

2013-11-01

384

Approaches to characterizing human health risks of exposure to fibers.  

PubMed Central

Naturally occurring and man-made (synthetic) fibers of respirable sizes are substances that have been identified by the U.S. Environmental Protection Agency (U.S. EPA) as priority substances for risk reduction and pollution prevention under the Toxic Substances Control Act (TSCA). The health concern for respirable fibers is based on the link of occupational asbestos exposure and environmental erionite fiber exposure to the development of chronic respiratory diseases, including interstitial lung fibrosis, lung cancer, and mesothelioma in humans. There is also considerable laboratory evidence indicating that a variety of fibers of varying physical and chemical characteristics can elicit fibrogenic and carcinogenic effects in animals under certain exposure conditions. This paper discusses key scientific issues and major default assumptions and uncertainties pertaining to the risk assessment of inhaled fibers. This is followed by a description of the types of assessment performed by the U.S. EPA to support risk management actions of new fibers and existing fibers under TSCA. The scope and depth of these risk assessments, however, vary greatly depending on whether the substance under review is an existing or a new fiber, the purpose of the assessment, the availability of data, time, and resources, and the intended nature of regulatory action. In general, these risk assessments are of considerable uncertainty because health hazard and human exposure information is often incomplete for most fibers. Furthermore, how fibers cause diseases and what specific determinants are critical to fiber-induced toxicity and carcinogenicity are still not completely understood. Further research to improve our knowledge base in fiber toxicology and additional toxicity and exposure data gathering are needed to more accurately characterize the health risks of inhaled fibers. PMID:9400747

Vu, V T; Lai, D Y

1997-01-01

385

Evaluation of the cloudy sky solar UVA radiation exposures.  

PubMed

The influence of cloud on the solar UVA (320-400 nm) exposures over five minute periods on a horizontal plane has been investigated. The first approach used cloud modification factors that were evaluated using the influence of clouds on the global solar exposures (310-2800 nm) and a model developed to apply these to the clear sky UVA exposures to allow calculation of the five minute UVA exposures for any cloud conditions. The second approach established a relationship between the UVA and the global solar exposures. The models were developed using the first six months of data in 2012 for SZA less than or equal to 70° and were applied and evaluated for the exposures in the second half of 2012. This comparison of the modelled exposures for all cloud conditions to the measured data provided an R(2) of 0.8 for the cloud modification model, compared to an R(2) of 0.7 for the UVA/global model. The cloud modification model provided 73% of the five minute exposures within 20% of the measured UVA exposures. This was improved to 89% of the exposures within 20% of the measured UVA exposures for the cases of cloud with the sun not obscured. PMID:24935414

Parisi, A V; Downs, N; Turner, J

2014-09-01

386

[Radiation exposure and risk of radon in the room air of Swiss houses].  

PubMed

The radioactive noble gas radon, a member of the natural decay chains of uranium and thorium, enters the indoor environment in regionally highly diverging amounts. Subsoil of dwellings, building materials and drinking water are the main sources. In Switzerland and in many other countries, exposure of the lung tissue to the short lived radon decay products is the most important component of the radiation dose of the general public. Annual doses in areas with crystalline rock of high uranium content may reach the limits set up for occupational exposure. However, a clear link between cumulative exposure to radon daughters and elevation of the lung cancer incidence exists only for underground miners. The majority of human epidemiological studies point to a linear dose effect relationship. The indoor radon levels are determined by geology, building materials and techniques, climate and behaviour of the occupants. Experiences from Scandinavia and the Northern parts of America clearly indicate the possibility of cost-efficient remedial measures to reduce indoor radon levels. PMID:3008463

Burkart, W

1986-01-01

387

Understanding engineered nanomaterial skin interactions and the modulatory effects of ultraviolet radiation skin exposure.  

PubMed

The study of engineered nanomaterials for the development of technological applications, nanomedicine, and nano-enabled consumer products is an ever-expanding discipline as is the concern over the impact of nanotechnology on human environmental health and safety. In this review, we discuss the current state of understanding of nanomaterial skin interactions with a specific emphasis on the effects of ultraviolet radiation (UVR) skin exposure. Skin is the largest organ of the body and is typically exposed to UVR on a daily basis. This necessitates the need to understand how UVR skin exposure can influence nanomaterial skin penetration, alter nanomaterial systemic trafficking, toxicity, and skin immune function. We explore the unique dichotomy that UVR has on inducing both deleterious and therapeutic effects in skin. The subject matter covered in this review is broadly informative and will raise awareness of potential increased risks from nanomaterial skin exposure associated with specific occupational and life style choices. The UVR-induced immunosuppressive response in skin raises intriguing questions that motivate future research directions in the nanotoxicology and nanomedicine fields. PMID:24123977

Jatana, Samreen; DeLouise, Lisa A

2014-01-01

388

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

SciTech Connect

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

Fabrikant, J.I.

1982-06-01

389

ANALYSIS OF HUMAN ACTIVITY DATA FOR USE IN MODELING ENVIRONMENTAL EXPOSURES  

EPA Science Inventory

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

390

Heavy ion radiation exposure triggered higher intestinal tumor frequency and greater ?-catenin activation than ? radiation in APC(Min/+) mice.  

PubMed

Risk of colorectal cancer (CRC) after exposure to low linear energy transfer (low-LET) radiation such as ?-ray is highlighted by the studies in atom bomb survivors. On the contrary, CRC risk prediction after exposure to high-LET cosmic heavy ion radiation exposure is hindered due to scarcity of in vivo data. Therefore, intestinal tumor frequency, size, cluster, and grade were studied in APC(Min/+) mice (n = 20 per group; 6 to 8 wks old; female) 100 to 110 days after exposure to 1.6 or 4 Gy of heavy ion (56)Fe radiation (energy: 1000 MeV/nucleon) and results were compared to ? radiation doses of 2 or 5 Gy, which are equitoxic to 1.6 and 4 Gy (56)Fe respectively. Due to relevance of lower doses to radiotherapy treatment fractions and space exploration, we followed 2 Gy ? and equitoxic 1.6 Gy (56)Fe for comparative analysis of intestinal epithelial cell (IEC) proliferation, differentiation, and ?-catenin signaling pathway alterations between the two radiation types using immunoblot, and immunohistochemistry. Relative to controls and ?-ray, intestinal tumor frequency and grade was significantly higher after (56)Fe radiation. Additionally, tumor incidence per unit of radiation (per cGy) was also higher after (56)Fe radiation relative to ? radiation. Staining for phospho-histone H3, indicative of IEC proliferation, was more and alcian blue staining, indicative of IEC differentiation, was less in (56)Fe than ? irradiated samples. Activation of ?-catenin was more in (56)Fe-irradiated tumor-free and tumor-bearing areas of the intestinal tissues. When considered along with higher levels of cyclin D1, we infer that relative to ? radiation exposure to (56)Fe radiation induced markedly reduced differentiation, and increased proliferative index in IEC resulting in increased intestinal tumors of larger size and grade due to preferentially greater activation of ?-catenin and its downstream effectors. PMID:23555653

Datta, Kamal; Suman, Shubhankar; Kallakury, Bhaskar V S; Fornace, Albert J

2013-01-01

391

Heavy Ion Radiation Exposure Triggered Higher Intestinal Tumor Frequency and Greater ?-Catenin Activation than ? Radiation in APCMin/+ Mice  

PubMed Central

Risk of colorectal cancer (CRC) after exposure to low linear energy transfer (low-LET) radiation such as ?-ray is highlighted by the studies in atom bomb survivors. On the contrary, CRC risk prediction after exposure to high-LET cosmic heavy ion radiation exposure is hindered due to scarcity of in vivo data. Therefore, intestinal tumor frequency, size, cluster, and grade were studied in APCMin/+ mice (n?=?20 per group; 6 to 8 wks old; female) 100 to 110 days after exposure to 1.6 or 4 Gy of heavy ion 56Fe radiation (energy: 1000 MeV/nucleon) and results were compared to ? radiation doses of 2 or 5 Gy, which are equitoxic to 1.6 and 4 Gy 56Fe respectively. Due to relevance of lower doses to radiotherapy treatment fractions and space exploration, we followed 2 Gy ? and equitoxic 1.6 Gy 56Fe for comparative analysis of intestinal epithelial cell (IEC) proliferation, differentiation, and ?-catenin signaling pathway alterations between the two radiation types using immunoblot, and immunohistochemistry. Relative to controls and ?-ray, intestinal tumor frequency and grade was significantly higher after 56Fe radiation. Additionally, tumor incidence per unit of radiation (per cGy) was also higher after 56Fe radiation relative to ? radiation. Staining for phospho-histone H3, indicative of IEC proliferation, was more and alcian blue staining, indicative of IEC differentiation, was less in 56Fe than ? irradiated samples. Activation of ?-catenin was more in 56Fe-irradiated tumor-free and tumor-bearing areas of the intestinal tissues. When considered along with higher levels of cyclin D1, we infer that relative to ? radiation exposure to 56Fe radiation induced markedly reduced differentiation, and increased proliferative index in IEC resulting in increased intestinal tumors of larger size and grade due to preferentially greater activation of ?-catenin and its downstream effectors. PMID:23555653

Datta, Kamal; Suman, Shubhankar; Kallakury, Bhaskar V. S.; Fornace, Albert J.

2013-01-01

392

Critical windows of exposure for children's health: cancer in human epidemiological studies and neoplasms in experimental animal models.  

PubMed Central

In humans, cancer may be caused by genetics and environmental exposures; however, in the majority of instances the identification of the critical time window of exposure is problematic. The evidence for exposures occurring during the preconceptional period that have an association with childhood or adulthood cancers is equivocal. Agents definitely related to cancer in children, and adulthood if exposure occurs in utero, include: maternal exposure to ionizing radiation during pregnancy and childhood leukemia and certain other cancers, and maternal use of diethylstilbestrol during pregnancy and clear-cell adenocarcinoma of the vagina of their daughters. The list of environmental exposures that occur during the perinatal/postnatal period with potential to increase the risk of cancer is lengthening, but evidence available to date is inconsistent and inconclusive. In animal models, preconceptional carcinogenesis has been demonstrated for a variety of types of radiation and chemicals, with demonstrated sensitivity for all stages from fetal gonocytes to postmeiotic germ cells. Transplacental and neonatal carcinogenesis show marked ontogenetic stage specificity in some cases. Mechanistic factors include the number of cells at risk, the rate of cell division, the development of differentiated characteristics including the ability to activate and detoxify carcinogens, the presence of stem cells, and possibly others. Usefulness for human risk estimation would be strengthened by the study of these factors in more than one species, and by a focus on specific human risk issues. Images Figure 1 PMID:10852857

Anderson, L M; Diwan, B A; Fear, N T; Roman, E

2000-01-01

393

Method for minimizing the radiation exposure from scoliosis radiographs. [X ray  

SciTech Connect

The radiation exposure resulting from standard scoliosis radiographs was determined for eighteen adolescent girls. The risk of inducing breast cancer was estimated from the skin-exposure doses. The average skin exposure to the breasts was 59.6 millirads (0.59 mGy) for the anteroposterior radiograph. Assuming a total of twenty-two anteroposterior radiographs during a course of treatment, the cumulative exposure would result in a 1.35% relative increase in the risk of development of breast cancer. By utilizing collimation of the x-ray beam and proper selection of grids, films, and screens, the radiation risk of scoliosis radiographs is minimized.

De Smet, A.A.; Fritz, S.L.; Asher, M.A.

1981-01-01

394

Phosphoproteomics Profiling of Human Skin Fibroblast Cells Reveals Pathways and Proteins Affected by Low Doses of Ionizing Radiation  

PubMed Central

Background High doses of ionizing radiation result in biological damage; however, the precise relationships between long-term health effects, including cancer, and low-dose exposures remain poorly understood and are currently extrapolated using high-dose exposure data. Identifying the signaling pathways and individual proteins affected at the post-translational level by radiation should shed valuable insight into the molecular mechanisms that regulate dose-dependent responses to radiation. Principal Findings We have identified 7117 unique phosphopeptides (2566 phosphoproteins) from control and irradiated (2 and 50 cGy) primary human skin fibroblasts 1 h post-exposure. Semi-quantitative label-free analyses were performed to identify phosphopeptides that are apparently altered by radiation exposure. This screen identified phosphorylation sites on proteins with known roles in radiation responses including TP53BP1 as well as previously unidentified radiation-responsive proteins such as the candidate tumor suppressor SASH1. Bioinformatic analyses suggest that low and high doses of radiation affect both overlapping and unique biological processes and suggest a role for MAP kinase and protein kinase A (PKA) signaling in the radiation response as well as differential regulation of p53 networks at low and high doses of radiation. Conclusions Our results represent the most comprehensive analysis of the phosphoproteomes of human primary fibroblasts exposed to multiple doses of ionizing radiation published to date and provide a basis for the systems-level identification of biological processes, molecular pathways and individual proteins regulated in a dose dependent manner by ionizing radiation. Further study of these modified proteins and affected networks should help to define the molecular mechanisms that regulate biological responses to radiation at different radiation doses and elucidate the impact of low-dose radiation exposure on human health. PMID:21152398

Yang, Feng; Waters, Katrina M.; Miller, John H.; Gritsenko, Marina A.; Zhao, Rui; Du, Xiuxia; Livesay, Eric A.; Purvine, Samuel O.; Monroe, Matthew E.; Wang, Yingchun; Camp, David G.; Smith, Richard D.; Stenoien, David L.

2010-01-01

395

Radiation-induced immunogenic modulation of tumor enhances antigen processing and calreticulin exposure, resulting in enhanced T-cell killing.  

PubMed

Radiation therapy (RT) is used for local tumor control through direct killing of tumor cells. Radiation-induced cell death can trigger tumor antigen-specific immune responses, but these are often noncurative. Radiation has been demonstrated to induce immunogenic modulation (IM) in various tumor types by altering the biology of surviving cells to render them more susceptible to T cell-mediated killing. Little is known about the mechanism(s) underlying IM elicited by sub-lethal radiation dosing. We have examined the molecular and immunogenic consequences of radiation exposure in breast, lung, and prostate human carcinoma cells. Radiation induced secretion of ATP and HMGB1 in both dying and surviving tumor cells. In vitro and in vivo tumor irradiation induced significant upregulation of multiple components of the antigen-processing machinery and calreticulin cell-surface expression. Augmented CTL lysis specific for several tumor-associated antigens was largely dictated by the presence of calreticulin on the surface of tumor cells and constituted an adaptive response to endoplasmic reticulum stress, mediated by activation of the unfolded protein response. This study provides evidence that radiation induces a continuum of immunogenic alterations in tumor biology, from immunogenic modulation to immunogenic cell death. We also expand the concept of immunogenic modulation, where surviving tumor cells recovering from radiation-induced endoplasmic reticulum stress become more sensitive to CTL killing. These observations offer a rationale for the combined use of radiation with immunotherapy, including for patients failing RT alone. PMID:24480782

Gameiro, Sofia R; Jammeh, Momodou L; Wattenberg, Max M; Tsang, Kwong Y; Ferrone, Soldano; Hodge, James W

2014-01-30

396

Radiation-induced immunogenic modulation of tumor enhances antigen processing and calreticulin exposure, resulting in enhanced T-cell killing  

PubMed Central

Radiation therapy (RT) is used for local tumor control through direct killing of tumor cells. Radiation-induced cell death can trigger tumor antigen-specific immune responses, but these are often noncurative. Radiation has been demonstrated to induce immunogenic modulation (IM) in various tumor types by altering the biology of surviving cells to render them more susceptible to T cell-mediated killing. Little is known about the mechanism(s) underlying IM elicited by sub-lethal radiation dosing. We have examined the molecular and immunogenic consequences of radiation exposure in breast, lung, and prostate human carcinoma cells. Radiation induced secretion of ATP and HMGB1 in both dying and surviving tumor cells. In vitro and in vivo tumor irradiation induced significant upregulation of multiple components of the antigen-processing machinery and calreticulin cell-surface expression. Augmented CTL lysis specific for several tumor-associated antigens was largely dictated by the presence of calreticulin on the surface of tumor cells and constituted an adaptive response to endoplasmic reticulum stress, mediated by activation of the unfolded protein response. This study provides evidence that radiation induces a continuum of immunogenic alterations in tumor biology, from immunogenic modulation to immunogenic cell death. We also expand the concept of immunogenic modulation, where surviving tumor cells recovering from radiation-induced endoplasmic reticulum stress become more sensitive to CTL killing. These observations offer a rationale for the combined use of radiation with immunotherapy, including for patients failing RT alone. PMID:24480782

Gameiro, Sofia R.; Jammed, Momodou L.; Wattenberg, Max M.; Tsang, Kwong Y.; Ferrone, Soldano; Hodge, James W.

2014-01-01

397

Transient disruption of human pursuit-tracking performance for laser exposures below permissible exposure limits  

NASA Astrophysics Data System (ADS)

The proliferation of lasers for medical care, laser displays, industrial applications and audio- visual presentations has increased the potential for accidental intrabeam exposure to visible laser radiation. The output of these laser devices may be limited to below permissible exposure limits, but they are perceived as bright and can affect performance. The disruption experienced while viewing a laser is related to factors that include the retinal irradiance level, wavelength, ambient light level and mode (continuous wave (CW) and repetitively pulsed (RP)). This report describes studies where these factors were varied to assess the effects of laser light on tracking performance in a laboratory simulator and in a field study. Disruption was determined by measuring maximum error and total time off target. Performance disruption increased as irradiance levels increased and ambient light levels decreased.Under dawn/dusk conditions, relatively low-level laser energy produced performance disruption. Green laser light at the peak of the photopic sensitivity curve was more disruptive than red laser light. Increased error scores during CW and RP trials were attributed to average rather than peak power effects. More than 1500 laser exposures at levels up to MPE/2 have been given to volunteers. Despite transient performance disruption comparison of the pre- and post- laser visual performance tests and fundus evaluations wee unremarkable.

Stamper, David A.; Lund, David J.; Molchany, Jerome W.; Stuck, Bruce E.

1997-05-01

398

Surveillance for Radiation-Related Exposures Reported to the National Poison Data System  

PubMed Central

Objective To describe radiation-related exposures of potential public health significance reported to the National Poison Data System (NPDS). Introduction For radiological incidents, collecting surveillance data can identify radiation-related public health significant incidents quickly and enable public health officials to describe the characteristics of the affected population and the magnitude of the health impact which in turn can inform public health decision-making. A survey administered by the Council of State and Territorial Epidemiologists (CSTE) to state health departments in 2010 assessed the extent of state-level planning for surveillance of radiation-related exposures and incidents: 70%–84% of states reported minimal or no planning completed. One data source for surveillance of radiological exposures and illnesses is regional poison centers (PCs), who receive information requests and reported exposures from healthcare providers and the public. Since 2010, the Centers for Disease Control and Prevention (CDC) and the American Association of Poison Control Centers (AAPCC) have conducted ongoing surveillance for exposures to radiation and radioactive materials reported from all 57 United States (US) PCs to NPDS, a web-based, national PC reporting database and surveillance system. Methods We collaborated with the American Association of Poison Control Centers (AAPCC), Poisindex® and Thomson Reuters Healthcare to develop an improved coding system for tracking radiation-related exposures reported to US PCs during 2011 and trained PC staff on its usage. We reviewed NPDS data from 1 September 2010 – 30 June 2012 for reported exposures to pharmaceutical or nonpharmaceutical radionuclides; ionizing radiation; radiological or nuclear weapons; or X-ray, alpha, beta, gamma, or neutron radiation. CDC medical toxicology and epidemiology staff reviewed each reported exposure to determine whether it was of potential public health concern (e.g. exposures associated with an ongoing public health emergency, several reported exposures clustered in space and time). When further information was needed to classify the potential public health importance of a call, CDC and AAPCC staff contacted the regional PC where each call originated. When exposures were spatially and temporally clustered, we reviewed news stories in the public media for evidence of an associated radiation incident. Results Of 419 exposures reported during the study period, 25 were associated with a radiation-related incident. Of these, 4 were related to an exposure to x-ray radiation from an industrial radiography incident, 11 were related to a transportation accident involving potential contamination with radioactive material, and 10 were related to the Fukushima Daiichi Japan nuclear reactor disaster. Public health, hazardous materials, or hospital radiation safety staff were involved in responding to each of these events. We also identified 26 reported exposures associated with a regional radiation anti-terrorism exercise. The reported exposures were followed-up and removed from analysis once we determined they were part of the exercise. The remaining (n=368; 88%) were either requests for information, confirmed non-exposures, or exposures deemed unrelated or non-significant. Conclusions The capability to monitor self- or clinician-reported exposures to radiation and radioactive materials is available in NPDS for state and local public health use in collaboration with their regional PC and may improve public health capacity to identify and respond to radiological emergencies. Next steps include testing the system’s capability to accurately classify and rapidly respond to a cluster of calls to PCs reporting radiation exposures associated with a “dirty bomb” exercise during July, 2012.

Law, Royal K.; Martin, Colleen; Bronstein, Alvin; Chang, Arthur; Schier, Joshua

2013-01-01

399

Search for chromosomal biomarkers specific to a prior exposure to densely ionizing radiation  

NASA Astrophysics Data System (ADS)

Recently there has been considerable interest in identifying biomarkers of radiation exposure that allow both to estimate the dose to which an individual has been exposed and to determine whether the initial exposure was to low or high LET radiation However published data are controversial probably due to large inter-laboratory differences in aberration scoring To contribute to this issue we reanalysed 35 data sets generated at GSI Darmstadt for human lymphocytes and fibroblasts as well as for Chinese hamster cells V79 CHO-K1 xrs5 In the experiments cells were exposed in G1-phase to heavy ions C O Ne Ar Kr Fe and Au ions covering an LET range of 13 to 4000 keV mu m For comparison X-ray experiments were performed More than 80000 first generation metaphases were analysed identified by BrdU incorporation and subsequent fluorescence-plus-Giemsa staining To account for drastic cell cycle transition delays after high LET exposure metaphases were collected at several post-irradiation sampling times Then for the analysis of data the aberration yields were averaged over dose and time For all cell types tested the aberration spectrum did not change up to LET value of about 200 keV mu m Thereafter LET-dependent changes occurred For example the fraction of dicentrics among all aberration-types detectable by Giemsa-staining declined while the fraction of excess acentrics increased Furthermore an unexpected high number of chromatid-type aberrations was found although cells have been exposed in G1-phase This observation

Ritter, S.; Sommer, S.; Yamada, S.

400

Human Exposure and Health Effects of Inorganic and Elemental Mercury  

PubMed Central

Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety. PMID:23230464

Zheng, Wei

2012-01-01

401

Hazards of the Deep: Killing the Dragons - Neurobiological Consequences of Space Radiation Exposures (401st Brookhaven Lecture)  

SciTech Connect

Since astronauts hope to spend more time n space, they will receive more exposure to ionizing radiation, a stream of particles that, when pass through a body, has enough energy to damage the components of living cells and tissues. Ionizing radiation may cause changes in cells' ability to carry out repair, reproduction, and cross-talk with other cells. This may lead to mutations, which, in turn, may result in tumors, cancer, genetic defects in offspring, neurodegeneration. A 34 million dollar facility at BNL's NASA Space Radiation Laboratory (NSRL), built in a cooperative effort by NASA and DOE is one of the few places in the world that can simulate the harsh space radiation environment. At this facility, scientists from some several institutions in the U.S. and abroad will learn about the possible risks to human beings exposed to space radiation. Although the spacecraft itself somewhat reduces radiat