Sample records for radiation exposure humans

  1. Human exposure to ultraviolet radiation

    SciTech Connect

    Passchier, W.F. (Health Council of the Netherlands, The Hague (NL)); Bosnjakovic, B.F.M. (Ministry of Housing, The Hague (NL))

    1987-01-01

    These proceedings contain over 50 selections. Some of the title are: Man and ultraviolet radiation; Effects of ultraviolet radiations on the human skin: emphasis on skin cancer; Human exposure to ultraviolet radiation: Quantitative modelling of skin cancer incidence; Human exposure to ultraviolet radiation: Data; and Share of erythema dose of solar radiation in high mountains.

  2. Exposure to UV radiation and human health

    Microsoft Academic Search

    Michael G. Kimlin

    2005-01-01

    This paper will overview the significant issues facing researchers in relating the impact of exposure to sunlight and human health. Exposure to solar ultraviolet radiation is the major causative factor in most sun-related skin and eye disorders, however, very little is known quantitatively about human UV exposures. Interestingly, human exposure to sunlight also has a nutritional impact, namely the development

  3. Overview of Radiation Environments and Human Exposures

    NASA Technical Reports Server (NTRS)

    Wilson, John W.

    2004-01-01

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

  4. A translatable predictor of human radiation exposure.

    PubMed

    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

    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

  5. Exposure to UV radiation and human health

    NASA Astrophysics Data System (ADS)

    Kimlin, Michael G.

    2005-08-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    Microsoft Academic Search

    James R. Jauchem

    1997-01-01

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

  9. Radiation Exposure

    MedlinePLUS

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

  10. Radiation-induced bystander effects: what are they, and how relevant are they to human radiation exposures?

    PubMed

    Blyth, Benjamin J; Sykes, Pamela J

    2011-08-01

    The term radiation-induced bystander effect is used to describe radiation-induced biological changes that manifest in unirradiated cells remaining within an irradiated cell population. Despite their failure to fit into the framework of classical radiobiology, radiation-induced bystander effects have entered the mainstream and have become established in the radiobiology vocabulary as a bona fide radiation response. However, there is still no consensus on a precise definition of radiation-induced bystander effects, which currently encompasses a number of distinct signal-mediated effects. These effects are classified here into three classes: bystander effects, abscopal effects and cohort effects. In this review, the data have been evaluated to define, where possible, various features specific to radiation-induced bystander effects, including their timing, range, potency and dependence on dose, dose rate, radiation quality and cell type. The weight of evidence supporting these defining features is discussed in the context of bystander experimental systems that closely replicate realistic human exposure scenarios. Whether the manifestation of bystander effects in vivo is intrinsically limited to particular radiation exposure scenarios is considered. The conditions under which radiation-induced bystander effects are induced in vivo will ultimately determine their impact on radiation-induced carcinogenic risk. PMID:21631286

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

    SciTech Connect

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

    1982-01-12

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

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

    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

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

    PubMed Central

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

    2014-01-01

    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

  14. Occupational radiation exposure: population studies.

    PubMed

    Schleipman, A Robert

    2005-01-01

    Occupational exposure to ionizing radiation in the medical setting differs from the acute exposure received by survivors of atomic bomb blasts. Yet, atomic bomb survivors' disease and mortality outcomes have been the standard data source on the effects of ionizing radiation on humans. Therefore, the prevailing estimated risks of ionizing radiation may not apply to radiologic technologists and other medical radiation workers. Carefully designed epidemiological trials provide evidence that helps determine the strength of association between exposure and onset of disease in selected populations. This article reviews radiation effects, explains some basic design concepts of epidemiologic trials and surveys the epidemiology literature related to radiation exposure to humans, with special attention to radiology staff. PMID:15732889

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

    SciTech Connect

    Rowley, J.D.

    1992-06-01

    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.

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

    PubMed

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

    2006-01-01

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

  17. Nuclear Energy: Radiation Exposure

    NSDL National Science Digital Library

    John Pratte

    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.

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

    Microsoft Academic Search

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

    2010-01-01

    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

  19. Evidence for radiation hormesis after in vitro exposure of human lymphocytes to low doses of ionizing radiation.

    PubMed

    Rithidech, Kanokporn Noy; Scott, Bobby R

    2008-01-01

    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

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

    PubMed Central

    Rithidech, Kanokporn Noy; Scott, Bobby R.

    2008-01-01

    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

  1. Medical radiation exposure and human carcinogenesis-genetic and epigenetic mechanisms.

    PubMed

    Dincer, Yildiz; Sezgin, Zeynep

    2014-09-01

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

  2. Americans' Average Radiation Exposure

    SciTech Connect

    NA

    2000-08-11

    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.

  3. Transmission of clonal chromosomal abnormalities in human hematopoietic stem and progenitor cells surviving radiation exposure.

    PubMed

    Kraft, Daniela; Ritter, Sylvia; Durante, Marco; Seifried, Erhard; Fournier, Claudia; Tonn, Torsten

    2015-07-01

    In radiation-induced acute myeloid leukemia (rAML), clonal chromosomal abnormalities are often observed in bone marrow cells of patients, suggesting that their formation is crucial in the development of the disease. Since rAML is considered to originate from hematopoietic stem and progenitor cells (HSPC), we investigated the frequency and spectrum of radiation-induced chromosomal abnormalities in human CD34(+) cells. We then measured stable chromosomal abnormalities, a possible biomarker of leukemia risk, in clonally expanded cell populations which were grown for 14 days in a 3D-matrix (CFU-assay). We compared two radiation qualities used in radiotherapy, sparsely ionizing X-rays and densely ionizing carbon ions (29 and 60-85keV/?m, doses between 0.5 and 4Gy). Only a negligible number of de novo arising, unstable aberrations (?0.05 aberrations/cell, 97% breaks) were measured in the descendants of irradiated HSPC. However, stable aberrations were detected in colonies formed by irradiated HSPC. All cells of the affected colonies exhibited one or more identical aberrations, indicating their clonal origin. The majority of the clonal rearrangements (92%) were simple exchanges such as translocations (77%) and pericentric inversions (15%), which are known to contribute to the development of rAML. Carbon ions were more efficient in inducing cell killing (maximum of ?30-35% apoptotic cells for 2Gy carbon ions compared to ?25% for X-rays) and chromosomal aberrations in the first cell-cycle after exposure (?70% and ?40% for 1Gy of carbon ions and X-rays, respectively), with a higher fraction of non-transmissible aberrations. In contrast, for both radiation qualities the percentage of clones with chromosomal abnormalities was similar (40%). Using the frequency of colonies with clonal aberrations as a surrogate marker for the leukemia risk following radiotherapy of solid tumors, charged particle therapy is not expected to lead to an increased risk of leukemia in patients. PMID:25938904

  4. 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)

    Denkins, P.; Badhwar, G.; Obot, V.; Wilson, B.; Jejelewo, O.

    2001-01-01

    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. c 2001. Elsevier Science Ltd. All rights reserved.

  5. 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 ...

  6. Malignant mesothelioma following radiation exposure

    SciTech Connect

    Antman, K.H.; Corson, J.M.; Li, F.P.; Greenberger, J.; Sytkowski, A.; Henson, D.E.; Weinstein, L.

    1983-11-01

    Mesothelioma developed in proximity to the field of therapeutic radiation administered 10-31 years previously in four patients. In three, mesothelioma arose within the site of prior therapeutic radiation for another cancer. Mesothelioma in the fourth patient developed adjacent to the site of cosmetic radiation to a thyroidectomy scar. None of these four patients recalled an asbestos exposure or had evidence of asbestosis on chest roentgenogram. Lung tissue in one patient was negative for ferruginous bodies, a finding considered to indicate no significant asbestos exposure. Five other patients with radiation-associated mesothelioma have been reported previously, suggesting that radiation is an uncommon cause of human mesothelioma. Problems in the diagnosis of radiation-associated mesotheliomas are considered.

  7. 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...

  8. Biological monitoring of radiation exposure.

    PubMed

    Horneck, G

    1998-01-01

    Complementary to physical dosimetry, biological dosimetry systems have been developed and applied which weight the different components of environmental radiation according to their biological efficacy. They generally give a record of the accumulated exposure of individuals with high sensitivity and specificity for the toxic agent under consideration. Basically three different types of biological detecting/ monitoring systems are available: (i) intrinsic biological dosimeters that record the individual radiation exposure (humans, plants, animals) in measurable units. For monitoring ionizing radiation exposure, in situ biomarkers for genetic (e.g. chromosomal aberrations in human lymphocytes, germ line minisatellite mutation rates) or metabolic changes in serum, plasma and blood (e.g. serum lipids, lipoproteins, lipid peroxides, melatonin, antibody titer) have been used. (ii) Extrinsic biological dosimeters/indicators that record the accumulated dose in biological model systems. Their application includes long-term monitoring of changes in environmental UV radiation and its biological implications as well as dosimetry of personal UV exposure. (iii) Biological detectors/biosensors for genotoxic substances and agents such as bacterial assays (e.g. Ames test, SOS-type test) that are highly sensitive to genotoxins with high specificity. They may be applicable for different aspects in environmental monitoring including the International Space Station. PMID:11542407

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

    NASA Astrophysics Data System (ADS)

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

    2006-05-01

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

  10. 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)

    Denkins, Pamela; Badhwar, Gautam; Obot, Victor

    2000-01-01

    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.

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

    SciTech Connect

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

    1986-01-01

    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.

  12. Overview on experience to date on human exposure to space radiations

    Microsoft Academic Search

    V. M. Petrov

    1994-01-01

    The human exposure in space depends on the three factors: the flight trajectory, its date and duration and the cyclogram of the cosmonaut's activities. In the near-Earth orbits the daily dose varies within the limits of (1.5-5.0) . 10-4Gy. day-1 and greatly increases if the altitude increases. The mean daily quality factor is 1.6-2.0. Strong solar proton events in the

  13. DEMONSTRATION OF HUMAN EXPOSURE TOOLS

    EPA Science Inventory

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

  14. Photodamage to human skin by suberythemal exposure to solar ultraviolet radiation can be attenuated by sunscreens: a review.

    PubMed

    Seité, S; Fourtanier, A; Moyal, D; Young, A R

    2010-11-01

    The effects of acute or repeated suberythemal solar ultraviolet radiation (UVR) exposure on human skin have been insufficiently investigated. Such exposure almost certainly has important long-term consequences that include skin ageing and skin cancer. This review summarizes the published data on the biological effects of suberythemal exposure using a wide range of clinical, cellular and molecular endpoints, some of which may be considered as biomarkers for skin cancer and photoageing. We also include some recent unpublished results from our laboratories. The effects of UVA (320-400 nm), UVB (290-320 nm) and total solar UVR (290-400 nm) are compared. We demonstrate that avoiding sunburn does not prevent many indicators of cutaneous biological damage and that use of low sun protection factor (SPF) sunscreen can inhibit much of the damages induced by suberythemal exposure to UVR. However, even when applied correctly, sunscreen use will result in suberythemal exposure. The degree and spectral quality of such exposure will depend on the SPF and absorption spectrum of the sunscreen, but nonetheless it may contribute to cumulative photodamage. This review may help to determine the level of photoprotection required in sunscreens and daily use products, as well as the ideal ratio of UVB/UVA protection, to improve long-term photoprotection outcomes. PMID:20977441

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

    PubMed Central

    Sokolov, Mykyta; Neumann, Ronald

    2014-01-01

    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

  16. Up-regulation of Bcl-2 expression in cultured human lymphocytes after exposure to low doses of gamma radiation

    PubMed Central

    Azimian, Hosein; Bahreyni-Toossi, Mohammad Taghi; Rezaei, Abdul Rahim; Rafatpanah, Houshang; Hamzehloei, Tayebeh; Fardid, Reza

    2015-01-01

    Lymphocytes have demonstrated complex molecular responses to induced stress by ionizing radiation. Many of these reactions are mediated through modifications in gene expressions, including the genes involved in apoptosis. The primary aim of this study was to assess the effects of low doses of ionizing radiation on the apoptotic genes, expression levels. The secondary goal was to estimate the time-effect on the modified gene expression caused by low doses of ionizing radiation. Mononuclear cells in culture were exposed to various dose values ranged from 20 to 100 mGy by gamma rays from a Cobalt-60 source. Samples were taken for gene expression analysis at hours 4, 24, 48, 72, and 168 following to exposure. Expression level of two apoptotic genes; BAX (pro-apoptotic) and Bcl-2 (anti-apoptotic) were examined by relative quantitative real-time polymerase chain reaction (PCR), at different time intervals. Radio-sensitivity of peripheral blood mononucleated cells (PBMCs) was measured by the Bcl-2/BAX ratio (as a predictive marker for radio-sensitivity). The non-parametric two independent samples Mann–Whitney U-test were performed to compare means of gene expression. The results of this study revealed that low doses of gamma radiation can induce early down-regulation of the BAX gene of freshly isolated human PBMCs; however, these changes were restored to near normal levels after 168 hours. In most cases, expression of the Bcl-2 anti-apoptotic gene was up-regulated. Four hours following to exposure to low doses of gamma radiation, apoptotic gene expression is modified, this is manifested as adaptive response. Modification of these gene expressions seems to be a principle pathway in the early radioresistance response. In our study, we found that these changes were temporary and faded completely within a week.

  17. 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)

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

    2011-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    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.

  19. 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)

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

    2011-01-01

    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.

  20. Environmental Radiation Exposures

    Cancer.gov

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

  1. Radiation Exposure and Cancer

    MedlinePLUS

    ... what we know about these types of high-energy radiation and how they affect cancer risk. Cancer Compensation Programs for People Exposed to Radiation as Part of Nuclear Weapons Testing Between 1945 and 1962, several countries ...

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

    EPA Science Inventory

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

  3. Radiation exposure and Mission Strategies for Interplanetary Manned Missions (REMSIM)

    Microsoft Academic Search

    C. Cougnet; N. B. Crosby; S. Eckersley; C. Foullon; V. Guarnieri; S. Guatelli; D. Heynderickx; A. Holmes-Siedle; C. Lobascio; S. Masiello; P. Nieminen; G. Parisi; P. Parodi; M. A. Perino; M. G. Pia; R. Rampini; P. Spillantini; V. Tamburini; E. Tracino

    2004-01-01

    .  Cosmic radiation is an important problem for human interplanetary missions. The “Radiation Exposure and Mission Strategies for Interplanetary Manned Missions–REMSIM” study is summarised here. They are related to current strategies and countermeasures to ensure the protection of astronauts from radiation during interplanetary missions, with specific reference to: radiation environment and its variability; radiation effects on the crew; transfer trajectories and

  4. 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

  5. Calculating Radiation Exposures during Use of 14C-Labeled Nutrients, Food Components, and Biopharmaceuticals To Quantify Metabolic Behavior in Humans

    PubMed Central

    2010-01-01

    14C has long been used as a tracer for quantifying the in vivo human metabolism of food components, biopharmaceuticals, and nutrients. Minute amounts (?1 × 10 ?18 mol) of 14C can be measured with high-throughput 14C-accelerator mass spectrometry (HT 14C-AMS) in isolated chemical extracts of biological, biomedical, and environmental samples. Availability of in vivo human data sets using a 14C tracer would enable current concepts of the metabolic behavior of food components, biopharmaceuticals, or nutrients to be organized into models suitable for quantitative hypothesis testing and determination of metabolic parameters. In vivo models are important for specification of intake levels for food components, biopharmaceuticals, and nutrients. Accurate estimation of the radiation exposure from ingested 14C is an essential component of the experimental design. Therefore, this paper illustrates the calculation involved in determining the radiation exposure from a minute dose of orally administered 14C-?-carotene, 14C-?-tocopherol, 14C-lutein, and 14C-folic acid from four prior experiments. The administered doses ranged from 36 to 100 nCi, and radiation exposure ranged from 0.12 to 5.2 ?Sv to whole body and from 0.2 to 3.4 ?Sv to liver with consideration of tissue weighting factor and fractional nutrient. In comparison, radiation exposure experienced during a 4 h airline flight across the United States at 37000 ft was 20 ?Sv. PMID:20349979

  6. The Spectrum of Mitochondrial DNA Deletions is a Ubiquitous Marker of Ultraviolet Radiation Exposure in Human Skin

    Microsoft Academic Search

    Amanda J. Ray; Richard Turner; Osamu Nikaido; Jonathan L. Rees; Mark A. Birch-Machin

    2000-01-01

    We and colleagues have suggested that deletions of mitochondrial DNA may be useful as a biomarker of ultraviolet radiation exposure in skin. In this study using a southwestern approach involving monoclonal antibodies against thymine dimers we provide direct evidence for the presence of ultraviolet-induced damage in mitochondrial DNA purified from any nuclear DNA contamination. Previous studies have been limited, as

  7. Assessing exposure to radiation

    SciTech Connect

    Walter, K.

    1997-01-01

    Since the founding of Lawrence Livermore National Laboratory, we have been world leaders in evaluating the risks associated with radiation. Ultrasensitive tools allow us not only to measure radionuclides present in the body but also to reconstruct the radiation dose from past nuclear events and to project the levels of radiation that will still be present in the body for 50 years after the initial intake. A variety of laboratory procedures, including some developed here, give us detailed information on the effects of radiation at the cellular level. Even today, we are re-evaluating the neutron dose resulting from the bombing at Hiroshima. Our dose reconstruction and projection capabilities have also been applied to studies of Nagasaki, Chernobyl, the Mayak industrial complex in the former Soviet Union, the Nevada Test Site, Bikini Atoll, and other sites. We are evaluating the information being collected on individuals currently working with radioactive material at Livermore and elsewhere as well as previously collected data on workers that extends back to the Manhattan Project.

  8. [Radiation exposure and thyroid cancer].

    PubMed

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

    2012-01-01

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

  9. 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...

  10. 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)

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

    2003-01-01

    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.

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

    PubMed

    Collins, Daniel L

    2002-02-01

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

  12. 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

    Schoten, Eert

    1998-11-26

    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.

  13. Inflammatory Cytokine Expression and Sebum Production after Exposure of Cultured Human Sebocytes to Ultraviolet A Radiation and Light at Wavelengths of 650 nm and 830 nm

    PubMed Central

    Chae, Soo Yuhl; Ryu, Hyo Sub; Jang, Yong Hyun; Lee, Seok-Jong; Kim, Do Won

    2015-01-01

    Background The effectiveness of ultraviolet (UV) radiation, visible light, or infrared light therapy for the treatment of acne is the subject of ongoing scientific debate. Objective This study was conducted to investigate changes in sebum production and the expression of inflammatory cytokines, matrix metalloproteinases (MMPs), and antimicrobial peptides (AMPs), following exposure of cultured human sebocytes to UVA radiation and light at wavelengths of 650 nm and 830 nm. Methods Reverse transcription polymerase chain reaction assays were performed to measure the gene expression levels of inflammatory cytokines (interleukin [IL]-1?, IL-6, IL-8, and tumor necrosis factor-?), MMPs (MMP-1, MMP-3, and MMP-9), and AMPs (psoriasin, hBD-2, hBD-3, and LL-37) in cultured sebocytes after exposure to UVA radiation (2 J/cm2, 3 J/cm2, and 5 J/cm2) and light at wavelengths of 650 nm (14 J/cm2, 29 J/cm2, and 87 J/cm2) and 830 nm (5 J/cm2, 10 J/cm2, and 30 J/cm2). Expression of inflammatory cytokine proteins and sebum production were measured using enzyme-linked immunoassays and a lipid analysis kit, respectively. Results Exposure of cultured sebocytes to UVA radiation and light at wavelengths of 650 nm and 830 nm did not show a significant increase in the expression of inflammatory cytokines, MMPs, or AMPs. Sebum production was not significantly decreased after exposure to UVA radiation and light at both wavelengths. Conclusion We propose that UVA radiation, visible light, and infrared light can be used to target Propionibacterium acnes for the treatment of acne, without an increase in the expression of inflammatory biomarkers and sebum production. PMID:25834355

  14. HUMAN EXPOSURE ASSESSMENT USING IMMUNOASSAY

    EPA Science Inventory

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

  15. 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...

  16. Radiation exposures due to fossil fuel combustion

    NASA Astrophysics Data System (ADS)

    Beck, Harold L.

    The current consensus regarding the potential radiation exposures resulting from the combustion of fossil fuels is examined. Sources, releases and potential doses to humans are discussed, both for power plants and waste materials. It is concluded that the radiation exposure to most individuals from any pathway is probably insignificant, i.e. only a tiny fraction of the dose received from natural sources in soil and building materials. Any small dose that may result from power-plant emissions will most likely be from inhalation of the small insoluble ash particles from the more poorly controlled plants burning higher than average activity fuel, rather than from direct or indirect ingestion of food grown on contaminated soil. One potentially significant pathway for exposure to humans that requires further evaluation is the effect on indoor external ?-radiation levels resulting from the use of flyash in building materials. The combustion of natural gas in private dwellings is also discussed, and the radiological consequences are concluded to be generally insignificant, except under certain extraordinary circumstances.

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

    SciTech Connect

    Rowley, J.D.

    1992-06-01

    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.

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

    PubMed

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

    2013-01-01

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

  19. Accidental radiation exposure and azoospermia.

    PubMed

    Bezold, G; Gottlöber, P; Gall, H; Peter, R U

    2000-01-01

    Seven Georgian male soldiers (19-25 years old) had accidentally been exposed to radiation by Cs-137 between April 1996 and May 1997. No information about the exact time and duration of exposure was available. All patients presented with the subacute stage of Cutaneous Radiation Syndrome with deep painful ulcers on different body sites, predominantly on the legs. Semen analyses showed complete azoospermia in 4 patients, with elevated follicle-stimulating hormone (FSH) in 3 and elevated luteinizing hormone (LH) in 2 of them. One patient had severe oligozoospermia of 7 million sperm per mL, with normal sperm motility and morphology; his FSH and LH levels were elevated. One patient had complete normozoospermia, and the seventh patient had polyzoospermia of 340 million per mL; both of these patients had normal serum hormone levels. Only the patient with oligozoospermia reported a history of delayed testicular descent; his physical examination showed relatively soft and small testicles and a varicocele with considerable reflux. The physical andrological examinations were normal in the other 6 patients. It is very likely that the azoospermia in the 4 patients can be attributed to the radiation accident. In conclusion, it is essential to perform andrological examinations in patients who have been exposed to radiation even if there are only cutaneous injuries detectable, as a high percentage of them can show azoospermia. PMID:10819447

  20. A new radiation exposure record system

    SciTech Connect

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

    1993-04-01

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

  1. 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

    Rocke, David M. [University of California Davis

    2013-09-09

    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.

  2. Radiation and human health

    Microsoft Academic Search

    J. W. Gofman; Karl Z. Morgan

    1983-01-01

    An attempt is made in the book to permit a layman to understand radiation and its effects. A basic presentations of radiation physics, the biology of human cancer, teratogenesis and genetics are considered excellent and concise reviews. A discussion on radiation studies is presented. The most extensive part of the book is a discussion of the risks of radiation-induced cancer.

  3. [Comparative analysis of natural and synthetic antimutagens as regulators of gene expression in human cells under exposure to ionizing radiation].

    PubMed

    Mikhailov, V F; Shishkina, A A; Vasilyeva, I M; Shulenina, L V; Raeva, N F; Rogozhin, E A; Startsev, M I; Zasukhina, G D; Gromov, S P; Alfimov, M V

    2015-02-01

    This paper studies the effect of plant peptides of thionine Ns-W2 extracted from seeds of fennel flower (Nigella sativa) and ?-purothionine from wheat germs (Triticum kiharae), as well as a synthetic antimutagen (crown-compound), on the expression of several genes involved in the.control of cellular homeostasis, processes of carcinogenesis, and radiation response in human rhabdomyosarcoma cells (RD cells), T-lymphoblastoid cell line Jurkat, and blood cells. All of these agents acted as antimutagens-anticarcinogens, reducing the expression of genes involved in carcinogenesis (genes of families MMP, TIMP, and IAP and G-protein genes) in a tumor cell. A pronounced reduction in the mRNA level of these genes was caused by thionine Ns-W2, and the least effect was demonstrated by ?-purothionine. Antimutagens had very little effect on the mRNA levels of the several studied genes in normal blood cells. PMID:25966580

  4. Radiation Effect on Human Tissue

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    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.

  5. [Cutaneous radiation syndrome after accidental skin exposure to ionizing radiation].

    PubMed

    Peter, R U

    2013-12-01

    Accidental exposure of the human skin to single doses of ionizing radiation greater than 3 Gy results in a distinct clinical picture, which is characterized by a transient and faint erythema after a few hours, then followed by severe erythema, blistering and necrosis. Depending on severity of damage, the latter generally occurs 10-30 days after exposure, but in severe cases may appear within 48 hrs. Between three and 24 months after exposure, epidermal atrophy combined with progressive dermal and subcutaneous fibrosis is the predominant clinical feature. Even years and decades after exposure, atrophy of epidermis, sweat and sebaceous glands; telangiectases; and dermal and subcutaneous fibrosis may be found and even continue to progress. For this distinct pattern of deterministic effects following cutaneous accidental radiation exposure the term "cutaneous radiation syndrome (CRS)" was coined in 1993 and has been accepted by all international authorities including IAEA and WHO since 2000. In contrast to the classical concept that inhibition of epidermal stem cell proliferation accounts for the clinical symptomatology, research of the last three decades has demonstrated the additional crucial role of inflammatory processes in the etiology of both acute and chronic sequelae of the CRS. Therefore, therapeutic approaches should include topical and systemic anti-inflammatory measures at the earliest conceivable point, and should be maintained throughout the acute and subacute stages, as this reduces the need for surgical intervention, once necrosis has occurred. If surgical intervention is planned, it should be executed with a conservative approach; no safety margins are needed. Antifibrotic measures in the chronic stage should address the chronic inflammatory nature of this process, in which over-expression TGF beta-1 may be a target for therapeutic intervention. Life-long follow-up often is required for management of delayed effects and for early detection of secondary malignancies, which must be searched for especially in the borderline areas between clinically symptomatic and asymptomatic skin. PMID:24337304

  6. 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)

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

    2011-01-01

    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.

  7. Econometric model for age- and population-dependent radiation exposures

    SciTech Connect

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

    1991-01-01

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

  8. Solar radiation and human health

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

  9. 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 (...

  10. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles.

    PubMed

    Dörr, Harald; Meineke, Viktor

    2011-01-01

    Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed. PMID:22114866

  11. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles

    PubMed Central

    2011-01-01

    Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed. PMID:22114866

  12. Ultrasensitive Human Radiation Dosimetry

    NASA Technical Reports Server (NTRS)

    Hammen, Richard

    1985-01-01

    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.

  13. Risks and management of radiation exposure.

    PubMed

    Yamamoto, Loren G

    2013-09-01

    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

  14. Radiation Characteristics of Ingestible Wireless Devices in Human Intestine Following Radio Frequency Exposure at 430, 800, 1200, and 2400 MHz

    Microsoft Academic Search

    Lisheng Xu; Max Q.-H. Meng; Hongliang Ren; Yawen Chan

    2009-01-01

    In order to assess the compliance of ingested wireless device (IWD) with related international safety guidelines, the studies on the biological effects and the signal intensity of an IWD in two realistic human body models using the finite-difference time-domain (FDTD) method are reported in this paper. Simulation studies are carried out in 21 scenarios where the IWD is placed at

  15. Radiation exposure to anaesthetists during endovascular procedures.

    PubMed

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

    2015-01-01

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

  16. Radiation and human health

    Microsoft Academic Search

    1979-01-01

    The growing controversy over low-level radiation risks stems from challenges to the assumptions that had been made about dose rate, linear theory, and total-body exposure. The debate has focused on whether there is a risk threshold or whether linearity overstates low-level risks, both theories being consistent with the available data. The generally accepted consensus on the risks of cancer and

  17. 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...

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  19. 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...

  20. Cytogenetic research after accidental radiation exposure.

    PubMed

    Bauchinger, M

    1995-05-01

    Currently, chromosome aberration analysis in peripheral lymphocytes is the most sensitive method to estimate individual doses in accidental radiation exposures. The assessment of dose is particularly reliable in cases with acute, uniform, whole-body exposure or after irradiation of large parts of the body. However, the scenarios of most radiation accidents largely result in partial-body exposures or a non-uniform dose distribution. This complicates dose estimation especially in cases with protracted or fractionated exposures. Problems exist also for the dose reconstruction of radiation exposures occurring a long time before sampling. To overcome these problems, the Qdr method or the "contaminated Poisson" method can be used to determine meaningful dose estimates from data based on conventional scoring of dicentrics. Scoring of so-called stable translocations by the newly developed technique of chromosome painting should be particularly useful for estimating doses of past exposures or of dose accumulation. After incorporation of radionuclides with largely localized depositions in certain organs or tissues, realistic individual dose estimates cannot be achieved. Exemplified by incidents involving larger groups of the population such as in Chernobyl and Goiania and by single cases with serious overexposures, chromosome dosimetry is evaluated in the present article. PMID:7488944

  1. DOE occupational radiation exposure 1996 report

    SciTech Connect

    NONE

    1996-12-31

    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.

  2. Radiation exposure and safety for the electrophysiologist.

    PubMed

    Ernst, Sabine; Castellano, Isabel

    2013-10-01

    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

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

    PubMed

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

    2008-07-01

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

  4. Gamma radiation exposure of MCT diode arrays

    Microsoft Academic Search

    F. F. Sizov; I. O. Lysiuk; J. V. Gumenjuk-Sichevska; S. G. Bunchuk; V. V. Zabudsky

    2006-01-01

    Investigations of electrical properties of long-wavelength infrared (LWIR) mercury cadmium telluride arrays exposed to gamma-radiation have been performed. Resistance-area product characteristics of LWIR n+-p-photodiodes have been investigated using a microprobe technique at T ap 78 K before and after exposure to various doses of gamma-radiation (Co60 Gammas). The current transport mechanisms for those structures are described within the framework of

  5. Radiation and human health

    Microsoft Academic Search

    Gofman

    1981-01-01

    A review of a book dealing with the estimation of human health effects of radiation is presented. Risk assessment for carcinogenesis is based on the author's own method of statistics so that standard statistical methods cannot be applied. Several examples of the author's fallacies are discussed in this book review. (KRM)

  6. Fluoroscopic Radiation Exposure during Percutaneous Kyphoplasty

    PubMed Central

    2011-01-01

    Objective The author measured levels of fluoroscopic radiation exposure to the surgeon's body based on the different beam directions during kyphoplasty. Methods This is an observational study. A series of 84 patients (96 vertebral bodies) were treated with kyphoplasty over one year. The patients were divided into four groups based on the horizontal and vertical directions of the X-Ray beams. We measured radiation exposure with the seven dosimetry badges which were worn by the surgeon in each group (total of 28 badges). Twenty-four procedures were measured in each group. Cumulative dose and dose rates were compared between groups. Results Fluoroscopic radiation is received by the operator in real-time for approximately 50% (half) of the operation time. Thyroid protectors and lead aprons can block radiation almost completely. The largest dose was received in the chest irrespective of beam directions. The lowest level of radiation were received when X-ray tube was away from the surgeon and beneath the bed (dose rate of head, neck, chest, abdomen and knee : 0.2986, 0.2828, 0.9711, 0.8977, 0.8168 mSv, respectively). The radiation differences between each group were approximately 2.7-10 folds. Conclusion When fluoroscopic guided-KP is performed, the X-Ray tube should be positioned on the opposite side of the operator and below the table, otherwise the received radiation to the surgeon's body would be 2.7-10 times higher than such condition. PMID:21494361

  7. Radiation exposure in interventional radiology

    NASA Astrophysics Data System (ADS)

    Pinto, N. G. V.; Braz, D.; Vallim, M. A.; Filho, L. G. P.; Azevedo, F. S.; Barroso, R. C.; Lopes, R. T.

    2007-09-01

    The aim of this study is to evaluate dose values in patients and staff involved in some interventional radiology procedures. Doses have been measured using thermoluminescent dosemeters for single procedures (such as renal and cerebral arteriography, transjungular intrahepatic portasystemic shunt (TIPS) and chemoembolization). The magnitude of doses through the hands of interventional radiologists has been studied. Dose levels were evaluated in three points for patients (eye, thyroid and gonads). The dose-area product (DAP) was also investigated using a Diamentor (PTW-M2). The dose in extremities was estimated for a professional who generally performed one TIPS, two chemoembolizations, two cerebral arteriographies and two renal arteriographies in a week. The estimated annual radiation dose was converted to effective dose as suggested by the 453-MS/Brazil norm The annual dose values were 137.25 mSv for doctors, 40.27 mSv for nurses and 51.95 mSv for auxiliary doctors, and all these annual dose values are below the limit established. The maximum values of the dose obtained for patients were 6.91, 10.92 and 15.34 mGy close to eye, thyroid and gonads, respectively. The DAP values were evaluated for patients in the same interventional radiology procedures. The dose and DAP values obtained are in agreement with values encountered in the literature.

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

    Microsoft Academic Search

    I. V. Ingole; S. K. Ghosh

    2006-01-01

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

  9. Benzene: Environmental partitioning and human exposure

    Microsoft Academic Search

    H. A. Hattemer-Frey; C. C. Travis; M. L. Land

    1990-01-01

    A multimedia transport model was used to evaluate the environmental partitioning of benzene. Measured and predicted environmental concentrations were used to estimate the accumulation of benzene in the food chain and the subsequent extent of human exposure from inhalation and ingestion. Results show that benzene partitions mainly into air (99.9%) and that inhalation is the dominant pathway of human exposure,

  10. Comparative Analysis of Whole-Genome Gene Expression Changes in Cultured Human Embryonic Stem Cells in Response to Low, Clinical Diagnostic Relevant, and High Doses of Ionizing Radiation Exposure.

    PubMed

    Sokolov, Mykyta; Nguyen, Van; Neumann, Ronald

    2015-01-01

    The biological effects of low-dose ionizing radiation (LDIR) exposure in humans are not comprehensively understood, generating a high degree of controversy in published literature. The earliest stages of human development are known to be among the most sensitive to stress exposures, especially genotoxic stresses. However, the risks stemming from exposure to LDIR, particularly within the clinical diagnostic relevant dose range, have not been directly evaluated in human embryonic stem cells (hESCs). Here, we describe the dynamics of the whole genome transcriptional responses of different hESC lines to both LDIR and, as a reference, high-dose IR (HDIR). We found that even doses as low as 0.05 Gy could trigger statistically significant transient changes in a rather limited subset of genes in all hESCs lines examined. Gene expression signatures of hESCs exposed to IR appear to be highly dose-, time-, and cell line-dependent. We identified 50 genes constituting consensus gene expression signature as an early response to HDIR across all lines of hESC examined. We observed substantial differences in biological pathways affected by either LDIR or HDIR in hESCs, suggesting that the molecular mechanisms underpinning the responses of hESC may fundamentally differ depending on radiation doses. PMID:26133243

  11. Treatment of radiation exposure and contamination.

    PubMed

    Wagner, R H; Boles, M A; Henkin, R E

    1994-03-01

    For treatment of radiation accident victims, procedures for handling trauma patients must be modified to ensure proper care and prevent contamination of hospital facilities and personnel. The radiation accident management plan should be instituted in advance. Exposure and contamination victims are treated differently. Exposed patients have sustained either partial or whole-body exposure but do not carry radioactive material; contaminated patients have also been exposed, but they have radioactive material either externally or internally and thus are continually exposed to radiation until the contaminant is removed. The treatment area and personnel must be protected with use of isolation, clean transfer techniques, and appropriate attire. After clothing has been removed, the patient's medical condition is assessed, stabilized, and treated. Samples from the affected areas, eyes, nose, and mouth are obtained for analysis and planning definitive treatment. For external contamination, the skin is washed with normal saline or mild detergent. Treatment of internal contamination is based on the isotopes involved and may include saturation of the crucial organ, dilution therapy, isotope displacement, or use of chelating agents. After a survey to ensure that no residual contamination remains, the patient is transferred to a care unit. Effects of exposure are seen over periods ranging from days to weeks to years, depending on the total dose received. Knowing the dose allows clinicians to predict what effects may ultimately occur. PMID:8190961

  12. 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

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

    1997-08-01

    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.

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

    E-print Network

    Rocke, David M.

    radiation therapy to treat a wide variety of cancer has resulted in increasing amounts of healthy tissueProteomic Analysis of Low Dose Arsenic and Ionizing Radiation Exposure on Keratinocytes Susanne R and ionizing radiation occur environmentally at low levels. While the human health effects of arsenic

  14. 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...

  15. Human occupational and nonoccupational exposure to fibers.

    PubMed Central

    Esmen, N A; Erdal, S

    1990-01-01

    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

  16. 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...

  17. 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...

  18. Community Engagement in Observational Human Exposure Studies

    EPA Science Inventory

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

  19. Intrauterine radiation exposures and mental retardation

    SciTech Connect

    Miller, R.W.

    1988-08-01

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

  20. Radiation Protection and the Human Radiation Experiments

    Microsoft Academic Search

    David Lloyd

    1998-01-01

    This book from the Los Alamos National Laboratory is largely a response to recent revelations and public concern about radiation experiments performed on human beings there and elsewhere, starting about 50 years ago. It is written for an intelligent lay person rather than for the specialist scientist and seeks to clarify the objectives and conduct of these human studies. The

  1. DOE 2008 Occupational Radiation Exposure October 2009

    SciTech Connect

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

    2009-10-01

    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.

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

    PubMed

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

    2006-06-01

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

  3. Measurement methods for human exposure analysis.

    PubMed Central

    Lioy, P J

    1995-01-01

    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

  4. Lead exposure and radiator repair work

    SciTech Connect

    Lussenhop, D.H.; Parker, D.L.; Barklind, A.; McJilton, C. (Minnesota Department of Health, Minneapolis (USA))

    1989-11-01

    In 1986, the ambient air for lead in radiator repair shops in the Minneapolis-St. Paul metropolitan area exceeded the Occupational Safety and Health Administration (OSHA) action level in nine of 12 shops sampled by Minnesota OSHA. We therefore sought to determine the prevalence of lead exposure/toxicity in this industry. Thirty-five radiator shops were identified, 30 were visited, and 53 workers were studied. The mean blood lead level was 1.53 (range 0.24-2.80). Seventeen individuals had blood lead levels greater than or equal to 1.93 mumol/L (40 micrograms/dl). The mean zinc protoporphyrin level (ZPP) was 0.55 mumol/L (range 0.16-1.43). No single worksite or personal characteristic was a strong determinant of either blood lead or ZPP level.

  5. Scatter radiation exposure during knee arthrography

    SciTech Connect

    Light, M.C.; Molloi, S.Y.; Yandow, D.R.; Ranallo, F.N.

    1987-09-01

    Knee arthrography, as performed at the authors' institution, was simulated and scattered radiation exposure to a radiologist's gonads, thyroid, and eye lens was measured with a sensitive ionization chamber. Results show that radiologists who regularly conduct knee arthrography examinations can incur doses to the gonads that are less than 6% of the U.S. limits, and to the thyroid and eye that are approximately 10% of the U.S. limits. Since the scatter radiation from overhead imaging of stress views constituted most (greater than or equal to 60%) of the dose to the lens of the eye and the thyroid, spot imaging was evaluated as a substitute for overhead imaging in the assessment of the anterior cruciate ligament. This substitution resulted in no loss of clinical information and has now completely replaced overhead imaging of stress views at this institution.

  6. Benzene: Environmental partitioning and human exposure

    SciTech Connect

    Hattemer-Frey, H.A.; Travis, C.C.; Land, M.L. (Lee Wan and Associates, Inc., Oak Ridge, TN (USA))

    1990-12-01

    A multimedia transport model was used to evaluate the environmental partitioning of benzene. Measured and predicted environmental concentrations were used to estimate the accumulation of benzene in the food chain and the subsequent extent of human exposure from inhalation and ingestion. Results show that benzene partitions mainly into air (99.9%) and that inhalation is the dominant pathway of human exposure, accounting for more than 99% of the total daily intake of benzene. Ingestion of contaminated food items represents only a minor pathway of human exposure. The long-term average daily intake of benzene by the general population of the U.S. was estimated using three independent methods. Intake estimates based on measured personal air exposures, measured exhaled air concentrations, and a pharmacokinetically derived adipose tissue concentration (73, 63, and 72 micrograms/day, respectively) are in good agreement. Although inhalation is the primary route of human exposure to background levels of benzene in the environment, smoking was found to be the largest anthropogenic source of background human exposure to benzene.

  7. Chromosomal "Fingerprints" of Prior Exposure to Densely Ionizing Radiation

    E-print Network

    Brenner, David Jonathan

    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

  8. Screening radiation exposure for quality assurance.

    PubMed

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

    2014-01-01

    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

  9. Radiation exposure estimates from extremely energetic solar proton events

    NASA Astrophysics Data System (ADS)

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

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

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

    SciTech Connect

    Morgan, William F.; Sowa, Marianne B.

    2011-04-27

    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.

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

    Microsoft Academic Search

    Letaw

    1988-01-01

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

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

    EPA Science Inventory

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

  13. Effects of high vs low-level radiation exposure

    SciTech Connect

    Bond, V.P.

    1983-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    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.

  15. Influence of Ultraviolet B Exposure on Immune Responses Following Hepatitis B Vaccination in Human Volunteers

    Microsoft Academic Search

    Annemarie Sleijffers; Johan Garssen; Frank R. de Gruijl; Greet J. Boland; Jan van Hattum; Willem A. van Vloten; Henk van Loveren

    2001-01-01

    Exposure to ultraviolet radiation can modulate immune responses in animal and humans. Remarkably, the ultraviolet-induced immunosuppression is not restricted to the exposed skin but is also found at other body sites, i.e., systemic immunosuppression. Effects of ultraviolet radiation on infections cannot be determined by experimentation on humans, but the effects of ultraviolet on vaccination may serve as a model. Moreover,

  16. A radiation exposure index for CT.

    PubMed

    Huda, Walter

    2013-12-01

    The purpose of this study is to define an Exposure Index for CT (EI(CT)) and to estimate the magnitude of the EI(CT) for common clinical CT examinations. For a single-axial rotation of a CT X-ray tube that includes only rays that pass through the patient, the CT Exposure Index (EI(CT)) is defined as the average Air Kerma that would be incident on an extended 360° detector array completely surrounding the patient. For an axial scan of a uniform cylindrical phantom, EI(CT) can be approximated as T × [(CTDI(air))/4] × [?°/360°] where T is the fractional transmission through the cylinder, CTDI(air) is the CT Dosimetry Index-determined 'free in air' at isocentre, and ?/2 is the fan beam angle that will completely irradiate a cylindrical phantom at isocentre. The value of CTDI(air) can be estimated from the weighted CTDI (CTDI(w)) for a given CT examination, and the angle ? depends on the irradiation geometry that can be obtained from the cylinder diameter (r) and the focus to isocentre distance (R). At a voltage of 120 kV, transmission through an adult head was ?2.6%, through an adult abdomen?0.4% and through a 5-y-old paediatric abdomen ?3%. Average ratios of CTDI(air)/CTDI(w) were 1.42 ± 0.12 in 16-cm dosimetry phantom and 2.82 ± 0.37 in 32-cm phantom. Values of ? ranged from 30.1° (R = 61 cm and r=8 cm) to 85.3° (R = 55 cm and r=20 cm). For an adult head CT examination, EI(CT) was estimated to be?70 µGy at a CTDI(vol) of 75 mGy (16 cm), and for an adult abdominal CT examination, EI(CT) was estimated to be?11 µGy at a CTDI(vol) of 25 mGy (32 cm). For an abdomen CT examination in a 5-y-old child, EI(CT) was estimated to be ?21 µGy at a CTDI(vol) of 20 mGy (16 cm). The EI(CT) is introduced that provides a quantitative measure of the amount of the radiation used to generate images in any CT examination and is analogous to the average image receptor Exposure Index recently proposed for use in projection imaging. The EI(CT) metric provides operators with an objective index of the amount of the radiation used to create CT images and can be used to control quantum mottle in CT. PMID:23690648

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

    SciTech Connect

    Rowley, J.D.

    1994-06-01

    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.

  18. Radiation exposure of LDEF: Initial results

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    Initial results from Long Duration Exposure Facility (LDEF) include radiation detector measurements from four experiments; P0006, P0004, M0004, and A0015. The detectors were located on both the leading and trailing edges of the orbiter and also at the Earthside end. This allowed the directional dependence of the incoming radiation to be measured. Total absorbed doses from thermoluminescent detectors (TLDs) verified the predicted spatial east-west dose dependence of a factor of approx. 2.5, due to trapped proton anisotropy in the South Atlantic Anomaly (SAA). On the trailing edge of the orbiter, a range of doses from 664 to 291 rad were measured under nominal shielding of 0.42 to 8.45 g/sq cm. A second set of detectors near this locations results are also given. On the leading edge, doses of 258 to 210 rad were found under shielding of 1.25 to 2.48 g/sq cm. Initial charged particle LET (linear energy transfer) spectra, fluxes, doses, and dose equivalents, for LET in H2O greater than or = 5 keV/micron, were measured with plastic nuclear track detectors located in the four experiments. Also, preliminary data on low energy neutrons were obtained from detectors containing (6)LiF foils.

  19. [Exposure of healthcare personnel to ionizing radiation in the light of radiation hormesis hypothesis].

    PubMed

    Kraska, Aleksandra; Bilski, Bartosz

    2012-01-01

    Radiation hormesis is a hypothetical premise that low doses of ionizing radiation (below 200 mSv) may be beneficial to living organisms. According to this hypothesis low doses of radiation stimulate the processes of DNA repair in cells. As a result they decrease the risk of aberration and the development of tumors.The theory of hormesis stands in contrast to the commonly accepted LNT-hypothesis, which suggests that low doses of radiation exert only small but also negative effects on organisms. However, the effects of high doses of radiation on the human organism are well elucidated, the effect of low doses is still unclear. Low doses of radiation are received, among others, by the health-care personnel who are employed in areas that are affected by ionizing radiation. In Poland they receive average effective individual doses to the whole body exposure of around 0.1-0.25 mSv per quarter of the year. Low doses of ionizing radiation, despite common views, may have a positive effect on health. However, one should approach this issue with some caution because of the current lack of sufficient and direct evidence that the theory of radiation hormesis is correct. PMID:22880457

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

    PubMed

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

    2013-06-01

    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

  1. 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...

  2. HUMAN EXPOSURE DATABASES DEVELOPMENT AND APPLICATIONS

    EPA Science Inventory

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

  3. DEVELOPING MEANINGFUL COHORTS FOR HUMAN EXPOSURE MODELS

    EPA Science Inventory

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

  4. Effects on G2/M Phase Cell Cycle Distribution and Aneuploidy Formation of Exposure to a 60 Hz Electromagnetic Field in Combination with Ionizing Radiation or Hydrogen Peroxide in L132 Nontumorigenic Human Lung Epithelial Cells

    PubMed Central

    Jin, Hee; Yoon, Hye Eun; Lee, Jae-Seon; Kim, Jae-Kyung; Myung, Sung Ho

    2015-01-01

    The aim of the present study was to assess whether exposure to the combination of an extremely low frequency magnetic field (ELF-MF; 60 Hz, 1 mT or 2 mT) with a stress factor, such as ionizing radiation (IR) or H2O2, results in genomic instability in non-tumorigenic human lung epithelial L132 cells. To this end, the percentages of G2/M-arrested cells and aneuploid cells were examined. Exposure to 0.5 Gy IR or 0.05 mM H2O2 for 9 h resulted in the highest levels of aneuploidy; however, no cells were observed in the subG1 phase, which indicated the absence of apoptotic cell death. Exposure to an ELF-MF alone (1 mT or 2 mT) did not affect the percentages of G2/M-arrested cells, aneuploid cells, or the populations of cells in the subG1 phase. Moreover, when cells were exposed to a 1 mT or 2 mT ELF-MF in combination with IR (0.5 Gy) or H2O2 (0.05 mM), the ELF-MF did not further increase the percentages of G2/M-arrested cells or aneuploid cells. These results suggest that ELF-MFs alone do not induce either G2/M arrest or aneuploidy, even when administered in combination with different stressors. PMID:25729273

  5. Enhanced radiation damage in irradiated and non-irradiated bystander regions by co-exposure to myosmine

    Microsoft Academic Search

    Erkang Jiang; Lingyan Zhu; Ye Zhao; Guoping Zhao; Linzhi Bao; Shaopeng Chen; Gen Yang; Jun Wang; An Xu; Lijun Wu

    2009-01-01

    It is important to evaluate the health effects of radiation concurrent exposure to chemicals in our daily life. Myosmine, an alkaloid in tobacco plants and various edibles and staple foods, has been considered as a co-genotoxic agent in vitro. In the present study, the damage induced by radiation concurrent exposure to myosmine was assessed in human primary cell line AG1522.

  6. Human mutagens: evidence from paternal exposure

    SciTech Connect

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

    1988-01-01

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

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

    SciTech Connect

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

    2006-06-05

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

  8. Radiation exposure in gastroenterology: improving patient and staff protection.

    PubMed

    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

    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

  9. Influence of Space Weather on Aircraft Ionizing Radiation Exposure

    Microsoft Academic Search

    Christopher J. Mertens; John W. Wilson; Steve R. Blattnig; Brian T. Kress; John W. Norbury; Michael J. Wiltberger; Stanley C. Solomon; W. Kent Tobiska

    2008-01-01

    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. During solar energetic particle (SEP) events, radiation

  10. Occupational Exposure to Natural Sources of Ionising Radiation in Ireland

    SciTech Connect

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

    2008-08-07

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  13. Reducing human exposure to Mycobacterium avium.

    PubMed

    Falkinham, Joseph O

    2013-08-01

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

  14. Stochastic Human Exposure and Dose Simulation Model for Pesticides

    EPA Science Inventory

    SHEDS-Pesticides (Stochastic Human Exposure and Dose Simulation Model for Pesticides) is a physically-based stochastic model developed to quantify exposure and dose of humans to multimedia, multipathway pollutants. Probabilistic inputs are combined in physical/mechanistic algorit...

  15. Human exposure to urban air pollution.

    PubMed Central

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

    1994-01-01

    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

  16. New results on radiation effects on human health

    Microsoft Academic Search

    Frantisek Spurny; Tsvetan P. Dachev

    2009-01-01

    Humans are exposed to ionizing radiation all the time, and it is known that it can induce a variety of harmful biological\\u000a effects. Consequently, it is necessary to quantitatively assess the level of exposure to this radiation as the basis for estimating\\u000a risks due to ionization radiation. During the Work Package 2400 of the COST-724\\/WG-2 action, a number of spacecraft

  17. Nuclear Fragmentation Processes Relevant for Human Space Radiation Protection

    NASA Technical Reports Server (NTRS)

    Lin, Zi-Wei

    2007-01-01

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

  18. Fear of the unknown: ionizing radiation exposure during pregnancy.

    PubMed

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

    2012-06-01

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

  19. Regulation of nuclear radiation exposures in India.

    PubMed

    Mishra, U C

    2004-01-01

    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

  20. Gene Expression Profiling of Biological Pathway Alterations by Radiation Exposure

    PubMed Central

    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

    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

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

  2. DOE 2010 Occupational Radiation Exposure November 2011

    SciTech Connect

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

    2011-11-11

    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.

  3. Radiation exposure limits for Japanese astronauts

    Microsoft Academic Search

    Takahiro Abe; Tatsuto Komiyama; Tatsunori Suemitsu

    1999-01-01

    Starting in 2001, Japanese astronauts will live aboard the International Space Station (ISS) for 3 to 6 months a year. For astronauts, space radiation is primarily hazardous. Therefore, the National Space Development Agency of Japan (NASDA) is developing a system for Space Radiation Safety Operations. This report describes our overall image of Space Radiation Safety Operations aboard the ISS, especially

  4. 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)

    Morgan, William F.

    2003-01-01

    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.

  5. Childhood cancer and occupational radiation exposure in parents

    Microsoft Academic Search

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

    1984-01-01

    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

  6. Childhood cancer and occupational radiation exposure in parents.

    PubMed

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

    1984-04-15

    To test the hypothesis that a parent's job exposure to radiation affects 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. PMID:6321012

  7. Control of excessive lead exposure in radiator repair workers

    SciTech Connect

    Not Available

    1991-03-01

    In 1988, 83 automotive repair workers with blood lead levels (BLLs) greater than 25 micrograms/dL were reported to state health departments in the seven states that collaborated with CDC's National Institute for Occupational Safety and Health (NIOSH) in maintaining registries of elevated BLLs in adults. In 18 (22%) of these 83 persons, BLLs were greater than 50 micrograms/dL. Among automotive repair workers for whom a job category was specified, radiator repair work was the principal source of lead exposure. The major sources of exposure for radiator repair workers are lead fumes generated during soldering and lead dust produced during radiator cleaning. This report summarizes current BLL surveillance data for radiator repair workers and describes three control technologies that are effective in reducing lead exposures in radiator repair shops.

  8. Long duration human exposure to microgravity

    NASA Technical Reports Server (NTRS)

    Huntoon, C. L.

    1991-01-01

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

  9. Correlation of chromosome patterns in human leukemic cells with exposure to chemicals and/or radiation. Progress report, July 1992--August 1993

    SciTech Connect

    Rowley, J.D.

    1993-09-01

    Progress in identification of chromosomal transformations associated with leukemogenesis is described. In particular progress in DNA cloning of chromosomal break points in human cancer patients is described.

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

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

  11. RECOMMENDED IONIZING RADIATION EXPOSURES FOR EARLY EXPLORATORY SPACE MISSIONS

    Microsoft Academic Search

    1962-01-01

    Attempts were made to estimate the allowable radiation doses, primarily ; due to high-energy proton emissions from solar flares, to be experienced by ; future space pilots. The size of the new permissible exposure dose for early ; missions will be higher than that presently permitted for radiation workers; ; nevertheless it must be low enough to prevent acute biological

  12. Ionizing radiation exposure and the development of intervertebral disc degeneration--no case to answer.

    PubMed

    Mellor, Fiona E; Breen, Alexander C

    2013-03-01

    In the following perspective article, Mellor and Breen provide a counterpoint to a previous perspective on the potential link between ionizing radiation exposure and intervertebral disc degeneration in humans [1]. The previous perspective asked, is this link a myth or reality? It suggested the potential for such a link. Mellor and Breen offer a drastically alternate view, in essence, that the question itself is flawed. To support their perspective, they explain the different units of radiation measurement and their conversion to risk in humans and how this impacts the previous perspective. They explain the variable sensitivity of different body tissues to radiation and highlight that neither human research nor any of the multiple international regulatory agencies have ever suggested that the intervertebral disc is sensitive to radiation. Finally, they claim that it is impossible to predict with any certainty the effects of low-level radiation on the intervertebral discs. PMID:23537450

  13. INSTRUCTION CONCERNING PRENATAL RADIATION EXPOSURE A. INTRODUCTION

    E-print Network

    Slatton, Clint

    Control Officer. Upon receipt of the statement by the Radiation Control Office, the University and the Radiation Control Officer in writing that she is pregnant and the estimated date of conception, the dose limit for the embryo/fetus from conception to birth (entire gestation period) is 500 mrem. Further

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

    EPA Science Inventory

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

  15. AN APPROACH TO METHODS DEVELOPMENT FOR HUMAN EXPOSURE ASSESSMENT STUDIES

    EPA Science Inventory

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

  16. PostTranscriptional Regulation of Interleukin6 Gene Expression in Human Keratinocytes by Ultraviolet B Radiation

    Microsoft Academic Search

    Sven de Vos; Marion Brach; Anne Budnik; Markus Grewe; Friedhelm Herrmann; Jean Krutmann

    1994-01-01

    Exposure to increasing doses (290-315 nm) of ultraviolet (UV) B radiation is thought to profoundly affect human health. Studies on the biologic and molecular effects of UVB radiation on human skin are therefore of particular interest. There is experimental and clinical evidence to assume that UVB radiation-induced local and systemic inflammatory reactions might be mediated at least in part by

  17. Effects of parental radiation exposure on developmental instability in grasshoppers

    PubMed Central

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

    2014-01-01

    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

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

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    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.

  19. Assessment of human exposure to gaseous pollutants

    SciTech Connect

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

    1989-09-01

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

  20. A procedure for the distinction between static and dynamic radiation exposures of personal radiation badges using pulsed optically stimulated luminescence

    Microsoft Academic Search

    M. S. Akselrod; N. Agersnap Larsen; S. W. S. McKeever

    2000-01-01

    A method is described for the distinction between the normal, “dynamic” radiation exposure of a personal radiation dosimetry badge during normal wear of the badge, and an abnormal, or “static” exposure of the badge in a fixed position relative to a radiation source. An example of a static exposure would be the intentional (unauthorized), or accidental, exposure of the badge

  1. Radiation dose assessment of exposure to depleted uranium

    Microsoft Academic Search

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

    2009-01-01

    Depleted uranium (DU) is claimed to contribute to human health problems, known as the Gulf War Syndrome and the Balkan Syndrome. Quantitative radiation dose is required to estimate the health risk of DU materials. The influences of the solubility parameters in the human alimentary tract and the respiratory tract systems and the aerosol particles size on the radiation dose of

  2. Molecular cloning of the human gene SUVCC3 associated with the formation of DNA-protein crosslinks following exposure to solar UV radiation

    SciTech Connect

    Rosenstein, B.S. [Mount Sinai School of Medicine, NY (United States)]|[Brown Univ. School of Medicine, Providence, RI (United States); Vaslet, C.A. [Brown Univ. School of Medicine, Providence, RI (United States)

    1995-07-01

    DRP 153 cells, which are hypersensitive to solar UV and deficient in the formation of DNA-protein crosslinks (DPC) following irradiation, were transfected with human DNA and a secondary transformant obtained in which a normal DPC response and solar UV sensitivity reestablished. DNA from this secondary transformant was used to construct a genomic DNA library from which a recombinant phage was isolated containing the human gene capable of restoring a normal DPC response and solar UV sensitivity to DRP 153. This gene has been designated SUVCC3 to denote solar UV cross-complementing gene number 3. 27 refs., 5 figs., 2 tabs.

  3. USE OF EXHALED BREATH CONDENSATE IN A HUMAN EXPOSURE STUDY

    EPA Science Inventory

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

  4. 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...

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

    EPA Science Inventory

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

  6. 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 ...

  7. ANTIOXIDANTS REDUCE CONSEQUENCES OF RADIATION EXPOSURE

    PubMed Central

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

    2009-01-01

    Antioxidants have been studied for their capacity to reduce the cytotoxic effects of radiation in normal tissues for at least 50 years. Early research identified sulfur-containing antioxidants as those with the most beneficial therapeutic ratio, even though these compounds have substantial toxicity when given in-vivo. Other antioxidant molecules (small molecules and enzymatic) have been studied for their capacity to prevent radiation toxicity both with regard to reduction of radiation-related cytotoxicity and for reduction of indirect radiation effects including long-term oxidative damage. Finally, categories of radiation protectors that are not primarily antioxidants, including those that act through acceleration of cell proliferation (e.g. growth factors), prevention of apoptosis, other cellular signaling effects (e.g. cytokine signal modifiers), or augmentation of DNA repair, all have direct or indirect effects on cellular redox state and levels of endogenous antioxidants. In this review we discuss what is known about the radioprotective properties of antioxidants, and what those properties tell us about the DNA and other cellular targets of radiation. PMID:18290327

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

    PubMed Central

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

    2013-01-01

    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

  9. Assessing radiation exposure during endoscopic-guided percutaneous nephrolithotomy

    PubMed Central

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

    2014-01-01

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

  10. Selective T cell killing of human lymphocytes by ultraviolet radiation

    Microsoft Academic Search

    S. Horowitz; D. Cripps; R. Hong

    1974-01-01

    The effects of ultraviolet radiation (uv) on human B and T lymphocytes were studied. In vitro studies showed that T lymphocytes were more sensitive to uv than B lymphocytes as assessed by eosin-dye exclusion. Following uv exposure, the viable lymphocytes responded to mitogens (PHA, PWM), and functional B lymphocytes were present at a time when no viable T cells were

  11. Radiation exposure and adverse health effects of interventional cardiology staff.

    PubMed

    Kesavachandran, Chandrasekharan Nair; Haamann, Frank; Nienhaus, Albert

    2013-01-01

    To the best of our knowledge, this chapter constitutes the first systematic review of radiation exposure to eyes, thyroid, and hands for Interventional Cardiology (IC) staff. We have concluded from our review that these anatomical locations are likely to be exposed to radiation as a result of the limited use of personal protective equipment (PPE) among IC staff as shown in Fig. 8. Our review also reveals that, with the exception of three eye exposure cases, the annual radiation dose to eyes, thyroid, and hands among IC staff was within recommended levels and limits. The As Low As Reasonably Achievable (ALARA) limit was not achieved in three cases for fingers/hands and four cases for eyes. However, an increased incidence of cataracts were reported for IC staff, and this gives rise to the concern that low-dose or unnoticed exposures may increase the risk of developing cataracts among cardiology staff. Clearly, the formation of cataracts among IC staff may be an issue and should be studied in more depth. Our review also disclosed that the two groups who receive excessive radiation doses (i.e., exceed the recommended limit) are physicians-in-training and junior staff physicians who work in cardiac catheterization laboratories. In particular, more attention should be given to assessing the effects of radiation exposure among IC staff who work in the Asia Pacific countries, because our review indicates that the number of IC procedures performed by IC staff in these countries is higher than for other continents. There is a huge demand for procedures conducted by IC staff in the Asia-Pacific area, for both treating patients and consulting with specialists. Our review also disclosed that recommended limits for per-procedure radiation doses are needed for IC staff. We recommend that such limits be established by the appropriate national and international agencies that are responsible for occupational radiation exposure. Although our review indicates that the current precautions against LDR exposure for IC staff are adequate in most cases, we are concerned about the relatively high incidence of cataracts reported to exist among IC staff. Therefore, we believe that there is a need for a strict implementation of radiation safety practices in cardiology laboratories and associated workplaces that utilize radiation. The action that is most important for protecting staff in the workplace against radiation exposure is the regular use of personal protective equipment or shielding. Working at a safe distance from instruments and assuring that such instruments are in the proper position are other techniques that can reduce the radiation dose received by IC staff. PMID:22990945

  12. 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...

  13. Savannah River Plant/Savannah River Laboratory radiation exposure report

    SciTech Connect

    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

    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.

  14. Cumulative radiation exposure in pediatric patients with congenital heart disease.

    PubMed

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

    2015-02-01

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

  15. An Overview of NASA's Risk of Cardiovascular Disease from Radiation Exposure

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

    The association between high doses of radiation exposure and cardiovascular damage is well established. Patients that have undergone radiotherapy for primary cancers of the head and neck and mediastinal regions have shown increased risk of heart and vascular damage and long-term development of radiation-induced heart disease [1]. In addition, recent meta-analyses of epidemiological data from atomic bomb survivors and nuclear industry workers has also shown that acute and chronic radiation exposures is strongly correlated with an increased risk of circulatory disease at doses above 0.5 Sv [2]. However, these analyses are confounded for lower doses by lifestyle factors, such as drinking, smoking, and obesity. The types of radiation found in the space environment are significantly more damaging than those found on Earth and include galactic cosmic radiation (GCR), solar particle events (SPEs), and trapped protons and electrons. In addition to the low-LET data, only a few studies have examined the effects of heavy ion radiation on atherosclerosis, and at lower, space-relevant doses, the association between exposure and cardiovascular pathology is more varied and unclear. Understanding the qualitative differences in biological responses produced by GCR compared to Earth-based radiation is a major focus of space radiation research and is imperative for accurate risk assessment for long duration space missions. Other knowledge gaps for the risk of radiation-induced cardiovascular disease include the existence of a dose threshold, low dose rate effects, and potential synergies with other spaceflight stressors. The Space Radiation Program Element within NASA's Human Research Program (HRP) is managing the research and risk mitigation strategies for these knowledge gaps. In this presentation, we will review the evidence and present an overview of the HRP Risk of Cardiovascular Disease and Other Degenerative Tissue Effects from Radiation Exposure.

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

    PubMed

    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

    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

  17. How Galactic Cosmic Ray models affect the estimation of radiation exposure in space

    NASA Astrophysics Data System (ADS)

    Mrigakshi, Alankrita Isha; Matthiä, Daniel; Berger, Thomas; Reitz, Günther; Wimmer-Schweingruber, Robert F.

    2013-03-01

    The radiation environment in space is a major concern for human spaceflight because of the adverse effects of high levels of radiation on astronauts' health. Therefore, it is essential to perform radiation risk assessments already during the concept studies of a manned mission. Galactic Cosmic Rays (GCR) have been identified to be one of the primary sources of radiation exposure in space.This work presents an evaluation of the radiation exposure caused by GCR between 1970 and 2011 in near-Earth interplanetary space and at the orbit of the International Space Station (ISS) by making numerical simulations with the Monte-Carlo framework GEANT4. Commonly used GCR models - CREME96, CREME2009 and Badhwar-O'Neill2010 are used to describe the GCR spectra and the differences arising from the application of these different models in terms of absorbed dose and dose equivalent rates are investigated. Additionally, the depth distribution of the dose quantities and the relative contribution of particles with different energies to the total exposure during solar maximum and minimum conditions are studied.The differences in the spectra, described by the models, result in considerable differences in the estimation of the radiation exposure.

  18. Health Impacts from Acute Radiation Exposure

    SciTech Connect

    Strom, Daniel J.

    2003-09-30

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

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

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

    SciTech Connect

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

    2006-12-01

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

  1. Radiation exposure and risk assessment for critical female body organs

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    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.

  2. Quantitative Assessment of the Radiation Exposure during Pathologic Process in the Sentinel Lymph Node Biopsy using Radioactive Colloid

    Microsoft Academic Search

    Yoo Sung Song; Jeong-Won Lee; Ho-Young Lee; Seok-Ki Kim; Keon Wook Kang; Myeong-Cherl Kook; Weon Seo Park; Geon Kook Lee; Eun-Kyung Hong; Eun-Sook Lee

    Purpose: Sentinel lymph node biopsy became the standard procedure in early breast cancer surgery. Faculty members might be exposed to a trace amount of radiation. The aim of this study is to quantify the radiation exposure and verify the safety of the procedure and the facilities, especially during pathologic process. Materials and Methods: Sentinel lymph node biopsies with Tc-99m human

  3. Radiation exposure of U.S. military individuals.

    PubMed

    Blake, Paul K; Komp, Gregory R

    2014-02-01

    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

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

    SciTech Connect

    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

    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.

  5. Radiation exposure of LDEF: Initial results

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

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

    Microsoft Academic Search

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

    2007-01-01

    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

  7. Final Report of the Radiation Exposure Compensation Act Committee

    NSDL National Science Digital Library

    Department of Energy

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

  8. DOE Radiation Exposure Monitoring System (REMS) Data Update

    SciTech Connect

    Rao, Nimi; Hagemeyer, Derek

    2012-05-05

    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.

  9. AIRCREW EXPOSURE FROM COSMIC RADIATION ON COMMERCIAL AIRLINE ROUTES

    Microsoft Academic Search

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

    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

  10. Radiation Exposure From Medical Imaging Time to Regulate?

    E-print Network

    Brenner, David Jonathan

    modern medical imaging, there are serious is- sues of quality control, training, and, particularly authority to regulate usage of x-ray devices. The exception is the 1992 Mammography Quality Stan- dards ActCOMMENTARY Radiation Exposure From Medical Imaging Time to Regulate? David J. Brenner, PhD Hedvig

  11. Medical management of three workers following a radiation exposure incident

    SciTech Connect

    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

    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.

  12. Overview of ICRP Committee 2 'Doses from Radiation Exposure'.

    PubMed

    Harrison, J

    2015-06-01

    Over many years, Committee 2 of the International Commission on Radiological Protection (ICRP) has provided sets of dose coefficients to allow users to evaluate equivalent and effective doses for intakes of radionuclides or exposure to external radiation for comparison with dose limits, constraints, and reference levels as recommended by ICRP. Following the 2007 Recommendations, Committee 2 and its task groups are engaged in a substantial programme of work to provide new dose coefficients for various conditions of radiation exposure. The methodology being applied in the calculation of doses can be regarded as state-of-the-art in terms of the biokinetic models used to describe the behaviour of inhaled and ingested radionuclides, and the dosimetric models used to model radiation transport for external and internal exposures. The level of sophistication of these models is greater than required for calculation of the protection quantities with their inherent simplifications and approximations, which were introduced necessarily, for example by the use of radiation and tissue weighting factors. However, ICRP is at the forefront of developments in this area, and its models are used for scientific as well as protection purposes. This overview provides an outline of recent work and future plans, including publications on dose coefficients for adults, children, and in-utero exposures, with new dosimetric phantoms in each case. The Committee has also recently finished a report on radiation exposures of astronauts in space, and is working with members of the other ICRP committees on the development of advice on the use of effective dose. PMID:25816256

  13. Characterisation of bubble detectors for aircrew and space radiation exposure.

    PubMed

    Green, A R; Bennett, L G I; Lewis, B J; Tume, P; Andrews, H R; Noulty, R A; Ing, H

    2006-01-01

    The Earth's atmosphere acts as a natural radiation shield which protects terrestrial dwellers from the radiation environment encountered in space. In general, the intensity of this radiation field increases with distance from the ground owing to a decrease in the amount of atmospheric shielding. Neutrons form an important component of the radiation field to which the aircrew and spacecrew are exposed. In light of this, the neutron-sensitive bubble detector may be ideal as a portable personal dosemeter at jet altitudes and in space. This paper describes the ground-based characterisation of the bubble detector and the application of the bubble detector for the measurement of aircrew and spacecrew radiation exposure. PMID:16987919

  14. Radiation exposure of aviation crewmembers and cancer.

    PubMed

    Bramlitt, Edward T; Shonka, Joseph J

    2015-01-01

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

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

    Microsoft Academic Search

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

    2004-01-01

    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

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

    SciTech Connect

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

    1996-06-01

    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.

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

    PubMed

    Fliedner, T M; Tibken, B; Hofer, E P; Paul, W

    1996-06-01

    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 semi-autonomous 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 cell pool to 5-10% of normal is compatible with the assumption of its "reversible" damage (to be treated by conventional replacement therapy including cytokines), whereas the reduction of blood granulocytes to levels of less than 200-300 per mm3 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. In order to test the approach, the same model was used to correlate the changing granulocyte pattern seen after autologous blood stem cell transfusion in patients treated with a 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. PMID:8635902

  18. Ultraviolet Radiation-Induced Damage to Human Langerhans Cells In Vivo Is Not Reversed by Ultraviolet A or Visible Light

    Microsoft Academic Search

    Joseph Alcalay; Leonard H. Goldberg; John E. Wolf Jr.; Margaret L. Kripke

    1990-01-01

    Exposure of human skin in vivo to UVB radiation induces pyrimidine dimers in DNA and alters the morphology and function of epidermal Langerhans cells. Cells in human skin have been reported to contain a photoreactivation repair mechanism that, following exposure to UVA or visible light, repairs UVB-induced pyrimidine dimers. The purpose of this study was to determine whether exposure to

  19. Astronaut Exposures to Ionizing Radiation in a Lightly-Shielded Spacesuit

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    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.

  20. Metaphase chromosome aberrations as markers of radiation exposure and dose

    SciTech Connect

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

    1992-10-01

    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.

  1. Metaphase chromosome aberrations as markers of radiation exposure and dose

    SciTech Connect

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

    1992-10-01

    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.

  2. Chromosome aberrations as biomarkers of radiation exposure: Modelling basic mechanisms

    NASA Astrophysics Data System (ADS)

    Ballarini, F.; Ottolenghi, A.

    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).

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

    Microsoft Academic Search

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

    2004-01-01

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

  4. Cell phone radiation exposure on brain and associated biological systems.

    PubMed

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

    2013-03-01

    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

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

    Microsoft Academic Search

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

    2011-01-01

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

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

    NASA Technical Reports Server (NTRS)

    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

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

    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.

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

    SciTech Connect

    Letaw, J.R.

    1988-03-31

    In recent years, there has been increasing concern about the radiation doses that will be suffered by astronauts on present-day and future space missions. In order to characterize radiation exposure risks on space missions one requires models of space-radiation environments, codes for transporting the components of ionizing radiation, and procedures for assessing radiation risks of a given exposure. To verify their accuracy, predictions based on these transport results must then be compared with existing dosimetry data. Linear energy transfer (LET) spectra, absorbed dose, and dose equivalent from galactic cosmic radiation and its fragments are presented for four, representative low-earth orbit configurations. The orbits include a high (STS-5IJ) and low (STS-61C) altitude, low-inclination (28.5 degs) flight; a high inclination (49.5 degs) flight (STS-51F); and a polar flight. Results are compared with computations for an exo-magnetospheric flight.

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

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

    Microsoft Academic Search

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

    2005-01-01

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

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

    PubMed

    Dörr, H; Baier, T; Meineke, V

    2013-12-01

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

  12. Luminescence of liquid nitrogen after exposure to pulsed UV radiation

    NASA Astrophysics Data System (ADS)

    Kirko, D. L.

    2015-04-01

    The optical characteristics of sustained weak luminescence of liquid nitrogen were studied after exposure to a pulse of UV radiation. The luminescence consisted of a bulk emission of the liquid and localized luminous regions. The luminescence spectrum of liquid nitrogen in UV-VIS range was studied. The UV radiation parameters that influence the excitation of the luminescence of liquid nitrogen were investigated. A possible scheme of bulk luminescence of liquid nitrogen and a hypothesis of the formation of localized luminous regions were discussed.

  13. Human exposure assessment resources on the World Wide Web.

    PubMed

    Schwela, Dieter; Hakkinen, Pertti J

    2004-05-20

    Human exposure assessment is frequently noted as a weak link and bottleneck in the risk assessment process. Fortunately, the World Wide Web and Internet are providing access to numerous valuable sources of human exposure assessment-related information, along with opportunities for information exchange. Internet mailing lists are available as potential online help for exposure assessment questions, e.g. RISKANAL has several hundred members from numerous countries. Various Web sites provide opportunities for training, e.g. Web sites offering general human exposure assessment training include two from the US Environmental Protection Agency (EPA) and four from the US National Library of Medicine. Numerous other Web sites offer access to a wide range of exposure assessment information. For example, the (US) Alliance for Chemical Awareness Web site addresses direct and indirect human exposures, occupational exposures and ecological exposure assessments. The US EPA's Exposure Factors Program Web site provides a focal point for current information and data on exposure factors relevant to the United States. In addition, the International Society of Exposure Analysis Web site provides information about how this society seeks to foster and advance the science of exposure analysis. A major opportunity exists for risk assessors and others to broaden the level of exposure assessment information available via Web sites. Broadening the Web's exposure information could include human exposure factors-related information about country- or region-specific ranges in body weights, drinking water consumption, etc. along with residential factors-related information on air changeovers per hour in various types of residences. Further, country- or region-specific ranges on how various tasks are performed by various types of consumers could be collected and provided. Noteworthy are that efforts are underway in Europe to develop a multi-country collection of exposure factors and the European Commission is in the early stages of planning and developing a Web-accessible information system (EIS-ChemRisks) to serve as a single gateway to all major European initiatives on human exposure to chemicals contained and released from cleaning products, textiles, toys, etc. PMID:15138040

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

    Microsoft Academic Search

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

    1984-01-01

    The Radiation Exposure Information Reporting System (REIRS) was initiated by the Atomic Energy Commission (AEC) in 1968. While the system has provided a general overview of radiation exposures associated with AEC\\/ERDA\\/DOE operations and has satisfied the original intent for a central information system, the need for more detailed information has become evident. The alternatives addressed for a radiation exposure information

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

    SciTech Connect

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

    2012-07-07

    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.

  16. UV Radiation and human health effects

    Microsoft Academic Search

    E. C. De Fabo; F. P. Noonan

    1996-01-01

    In this chapter we describe some of the potential effects of increased UVB radiation, due to stratospheric ozone depletion, on human health. These effects include immune suppression, and its role in skin cancer and infectious disease development. We describe also the association between UVB and cataract development. The concern about increased UVB radiation and its impact on human health stems

  17. Radiation exposure and risk assessment for critical female body organs

    SciTech Connect

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

    1991-07-01

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

  18. Radiation exposures in Utah from Nevada Nuclear Tests.

    PubMed

    Beck, H L; Krey, P W

    1983-04-01

    The exposure of the population of Utah to external gamma-radiation from the fallout from nuclear weapons tests carried out between 1951 and 1958 at the Nevada Test Site has been reconstructed from recent measurements of residual cesium-137 and plutonium in soil. Although the highest exposures were found in the extreme southwest part of Utah, as expected, the residents of the populous northern valleys around Provo, Salt Lake City, and Ogden received a higher mean dose and a significantly greater population dose (person-rads) than did the residents of most counties closer to the test site. However, population doses from external exposure throughout Utah were far too low to result in any statistically observable health effects. PMID:6828876

  19. Atomic veterans and their families: Responses to radiation exposure

    SciTech Connect

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

    1990-07-01

    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.

  20. TOLUENE EXPERIMENTAL EXPOSURES IN HUMANS: PHARMACOKINETICS AND BEHAVIOR

    EPA Science Inventory

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

  1. Functional genomics of UV radiation responses in human cells

    Microsoft Academic Search

    Christine A Koch-Paiz; Sally A Amundson; Michael L Bittner; Paul S Meltzer; Albert J Fornace

    2004-01-01

    The gene expression responses of MCF-7, a p53 wild-type (wt) human cell line, were monitored by cDNA microarray hybridization after exposure to different wavelengths of UV irradiation. Equitoxic doses of UVA, UVB, and UVC radiation were used to reduce survival to 37%. The effects of suramin, a signal pathway inhibitor, on the gene expression responses to the three UV wavelengths

  2. 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...

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

    SciTech Connect

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

    1983-04-01

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

  4. Stochastic Human Exposure and Dose Simulation Model for Wood Preservatives

    EPA Science Inventory

    SHEDS-Wood (Stochastic Human Exposure and Dose Simulation Model for Wood Preservatives) is a physically-based stochastic model that was developed to quantify exposure and dose of children to wood preservatives on treated playsets and residential decks. Probabilistic inputs are co...

  5. 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...

  6. 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...

  7. 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 ...

  8. Human Exposures to PAHs: an Eastern United States Pilot Study

    EPA Science Inventory

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

  9. SECOND NATIONAL REPORT ON HUMAN EXPOSURES TO ENVIRONMENTAL CHEMICALS

    EPA Science Inventory

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

  10. 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...

  11. Particle telescopes as a tool for assessment of depth-dose curves in human phantom and for radiation environment measurements during deep space missions

    Microsoft Academic Search

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

    2004-01-01

    Possible limitations imposed by the adverse effects of long-term exposure to cosmic radiation is a major obstacle to human space exploration. Concerning the human exploration of Mars, the radiation exposures to be received in transit to Mars and on the Mars surface have to be assessed. The evaluation of the radiation risk is needed concerning the spacecraft and Martian basis

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

    EPA Science Inventory

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

  13. ENVIRONMENTAL MONITORING AND HUMAN EXPOSURE ASSESSMENT USING IMMUNOCHEMICAL TECHNIQUES

    EPA Science Inventory

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

  14. Controlled human exposures to ambient pollutant particles in susceptible populations

    EPA Science Inventory

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

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

    PubMed

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

    2015-01-01

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

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

    Microsoft Academic Search

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

    2003-01-01

    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

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

    Microsoft Academic Search

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

    2010-01-01

    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

  18. An Introduction to Efficacy in Diagnostic Radiology and Nuclear Medicine (Justification of Medical Radiation Exposure)

    Microsoft Academic Search

    D McVicar

    1996-01-01

    To the radiation expert, many medical practitioners appear casual to the point of recklessness regarding radiation exposure to their own person. However, diagnostic radiologists are in a position to make a significant contribution to radiation protection of the population by discouraging unnecessary medical radiation exposure, by applying the time honoured medical dictum `if a test will not benefit the individual

  19. Solar radiation and human health

    Microsoft Academic Search

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

    2011-01-01

    The Sun has played a major role in the development of life on Earth. In Western culture, people are warned against Sun exposure because of its adverse effects: erythema, photoimmunosuppression, photoageing, photocarcinogenesis, cataracts and photokeratitis. However, Sun exposure is also beneficial, since moderate doses give beneficial physiological effects: vitamin D synthesis, reduction of blood pressure and mental health. Shortage of

  20. Intrinsic radiation resistance in human chondrosarcoma cells

    SciTech Connect

    Moussavi-Harami, Farid [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States); Mollano, Anthony [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States); Martin, James A. [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States); Ayoob, Andrew [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States); Domann, Frederick E. [Department of Radiation Oncology, Iowa City, IA 52245 (United States); Gitelis, Steven [Department of Internal Medicine, Section of Medical Oncology, Chicago, IL 60612 (United States); Department of Orthopaedics Rush-Presbyterian St. Luke's Medical Center, Chicago, IL 60612 (United States); Buckwalter, Joseph A. [Departments of Orthopaedics and Rehabilitation, University of Iowa, Iowa City, IA 52242 (United States)]. E-mail: joseph-buckwalter@uiowa.edu

    2006-07-28

    Human chondrosarcomas rarely respond to radiation treatment, limiting the options for eradication of these tumors. The basis of radiation resistance in chondrosarcomas remains obscure. In normal cells radiation induces DNA damage that leads to growth arrest or death. However, cells that lack cell cycle control mechanisms needed for these responses show intrinsic radiation resistance. In previous work, we identified immortalized human chondrosarcoma cell lines that lacked p16{sup ink4a}, one of the major tumor suppressor proteins that regulate the cell cycle. We hypothesized that the absence of p16{sup ink4a} contributes to the intrinsic radiation resistance of chondrosarcomas and that restoring p16{sup ink4a} expression would increase their radiation sensitivity. To test this we determined the effects of ectopic p16{sup ink4a} expression on chondrosarcoma cell resistance to low-dose {gamma}-irradiation (1-5 Gy). p16{sup ink4a} expression significantly increased radiation sensitivity in clonogenic assays. Apoptosis did not increase significantly with radiation and was unaffected by p16{sup ink4a} transduction of chondrosarcoma cells, indicating that mitotic catastrophe, rather than programmed cell death, was the predominant radiation effect. These results support the hypothesis that p16{sup ink4a} plays a role in the radiation resistance of chondrosarcoma cell lines and suggests that restoring p16 expression will improve the radiation sensitivity of human chondrosarcomas.

  1. Determination of Important Nuclear Fragmentation Processes for Human Space Radiation Protection

    NASA Technical Reports Server (NTRS)

    Lin, Zi-Wei

    2007-01-01

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

  2. 1.8 GHz Radio Frequency signal radiation effects on human health

    Microsoft Academic Search

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

    2011-01-01

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

  3. Determination of important nuclear fragmentation processes for human space radiation protection

    SciTech Connect

    Lin Ziwei [Mail Stop VP62, NSSTC, 320 Sparkman Drive, Huntsville, Alabama 35805 (United States)

    2007-03-15

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

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

    PubMed

    Folkerts, K H; Münz, A; Jung, S

    1997-04-01

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

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

    PubMed

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

    2014-03-01

    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

  6. Wood smoke in a controlled exposure experiment with human volunteers.

    PubMed

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

    2011-04-01

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

  7. Estimated Radiation Exposure from Medical Imaging in Hemodialysis Patients

    PubMed Central

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

    2011-01-01

    Radiation exposure accompanying medical imaging associates with cancer risk. Patients with recurrent or chronic diseases may be especially at risk, because they may undergo more of these procedures. The aim of this study was to assess the individual cumulative effective doses (CEDs), which quantify radiation from medical imaging procedures, in a cohort of 106 hemodialysis patients during a median follow-up of 3 years. We retrospectively calculated individual radiation exposures by collecting the number and type of radiologic procedures from hospital records. We also estimated organ doses for computed tomography procedures. The mean and median annual CEDs were 21.9 and 11.7 mSv per patient-year, respectively. The mean and median total CEDs per patient during the study period were 57.7 and 27.3 mSv, respectively. By radiation dose group, we classified 22 patients as low (<3 mSv/yr), 51 as moderate (3 to <20 mSv/yr), 22 as high (20 to <50 mSv/yr), and 11 as very high (?50 mSv/yr). Seventeen patients had a total CED >100 mSv, a value associated with a substantial increase in risk for cancer- mortality. Of the total CED,s 76% was a result of CT scanning. The annual CED significantly associated with age and transplant waitlist status. In summary, this study shows that a significant fraction of surviving hemodialysis patients during a 3-year period receives estimated radiation doses that may put them at an increased risk for cancer. PMID:21355057

  8. Cognitive deficits induced by 56Fe radiation exposure

    NASA Astrophysics Data System (ADS)

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

    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.

  9. Identification of Gene Expression Biomarkers for Predicting Radiation Exposure

    PubMed Central

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

    2014-01-01

    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

  10. Occupational Radiation Exposure during Endoscopic Retrograde Cholangiopancreatography and Usefulness of Radiation Protective Curtains

    PubMed Central

    Minami, Tomoyuki; Sasaki, Tamito; Serikawa, Masahiro; Kamigaki, Michihiro; Yukutake, Masanobu; Ishigaki, Takashi; Ishii, Yasutaka; Mouri, Teruo; Yoshimi, Satoshi; Shimizu, Akinori; Tsuboi, Tomofumi; Kurihara, Keisuke; Tatsukawa, Yumiko; Miyaki, Eisuke; Chayama, Kazuaki

    2014-01-01

    Objective. To evaluate the effectiveness of radiation protective curtains in reducing the occupational radiation exposure of medical personnel. Methods. We studied medical staff members who had assisted in 80 consecutive therapeutic endoscopic retrograde cholangiopancreatography (ERCP) procedures. Use of radiation protective curtains mounted to the X-ray tube was determined randomly for each procedure, and radiation doses were measured with electronic pocket dosimeters placed outside the protective apron. Results. When protective curtains were not used, the mean radiation doses to endoscopists, first assistants, second assistants, and nurses were 340.9, 27.5, 45.3, and 33.1?µSv, respectively; doses decreased to 42.6, 4.2, 13.1, and 10.6?µSv, respectively, when protective curtains were used (P < 0.01). When the patient had to be restrained during ERCP (n = 8), the radiation dose to second assistants without protective curtains increased by a factor of 9.95 (P < 0.01) relative to cases in which restraint was not required. Conclusions. During ERCP, not only endoscopists, but also assistants and nurses were exposed to high doses of radiation. Radiation exposure to staff members during ERCP was reduced with the use of protective curtains. PMID:25477956

  11. Occupational Radiation Exposure during Endoscopic Retrograde Cholangiopancreatography and Usefulness of Radiation Protective Curtains.

    PubMed

    Minami, Tomoyuki; Sasaki, Tamito; Serikawa, Masahiro; Kamigaki, Michihiro; Yukutake, Masanobu; Ishigaki, Takashi; Ishii, Yasutaka; Mouri, Teruo; Yoshimi, Satoshi; Shimizu, Akinori; Tsuboi, Tomofumi; Kurihara, Keisuke; Tatsukawa, Yumiko; Miyaki, Eisuke; Chayama, Kazuaki

    2014-01-01

    Objective. To evaluate the effectiveness of radiation protective curtains in reducing the occupational radiation exposure of medical personnel. Methods. We studied medical staff members who had assisted in 80 consecutive therapeutic endoscopic retrograde cholangiopancreatography (ERCP) procedures. Use of radiation protective curtains mounted to the X-ray tube was determined randomly for each procedure, and radiation doses were measured with electronic pocket dosimeters placed outside the protective apron. Results. When protective curtains were not used, the mean radiation doses to endoscopists, first assistants, second assistants, and nurses were 340.9, 27.5, 45.3, and 33.1?µSv, respectively; doses decreased to 42.6, 4.2, 13.1, and 10.6?µSv, respectively, when protective curtains were used (P < 0.01). When the patient had to be restrained during ERCP (n = 8), the radiation dose to second assistants without protective curtains increased by a factor of 9.95 (P < 0.01) relative to cases in which restraint was not required. Conclusions. During ERCP, not only endoscopists, but also assistants and nurses were exposed to high doses of radiation. Radiation exposure to staff members during ERCP was reduced with the use of protective curtains. PMID:25477956

  12. EXHALED BREATH ANALYSIS FOR HUMAN EXPOSURE RESEARCH

    EPA Science Inventory

    Exhaled breath collection and analysis has historically been used in environmental research studies to characterize exposures to volatile organic compounds. The use of this approach is based on the fact that many compounds present in blood are reflected in the breath, and that...

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

    PubMed Central

    Horn, Simon; Barnard, Stephen; Rothkamm, Kai

    2011-01-01

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

  14. MULTIPLE SOLVENT EXPOSURE IN HUMANS: CROSS-SPECIES EXTRAPOLATIONS

    EPA Science Inventory

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

  15. Human exposure to traffic pollution. Experience from Danish studies

    Microsoft Academic Search

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

    2001-01-01

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

  16. 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...

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

    EPA Science Inventory

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

  18. Delayed effects of external radiation exposure: A brief history

    SciTech Connect

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

    1995-11-01

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

  19. A different approach to evaluating health effects from radiation exposure

    SciTech Connect

    Bond, V.P.; Sondhaus, C.A.; Feinendegen, L.E.

    1988-01-01

    Absorbed dose D is shown to be a composite variable, the product of the fraction of cells hit (I/sub H/) and the mean /open quotes/dose/close quotes/ (hit size) /ovr z/ to those cells. D is suitable for use with high level (HLE) to radiation and its resulting acute organ effects because, since I/sub H/ = 1.0, D approximates closely enough the mean energy density in the cell as well as in the organ. However, with low-level exposure (LLE) to radiation and its consequent probability of cancer induction from a single cell, stochastic delivery of energy to cells results in a wide distribution of hit sizes z, and the expected mean value, /ovr z/, is constant with exposure. Thus, with LLE, only I/sub H/ varies with D so that the apparent proportionality between /open quotes/dose/close quotes/ and the fraction of cells transformed is misleading. This proportionality therefore does not mean that any (cell) dose, no matter how small, can be lethal. Rather, it means that, in the exposure of a population of individual organisms consisting of the constituent relevant cells, there is a small probabililty of particle-cell interactions which transfer energy. The probability of a cell transforming and initiating a cancer can only be greater than zero if the hit size (/open quotes/dose of energy/close quotes/) to the cell is large enough. Otherwise stated, if the /open quotes/dose/close quotes/ is defined at the proper level of biological organization, namely, the cell and not the organ, only a large dose z to that cell is effective. The above precepts are utilized to develop a drastically different approach to evaluation oif risk from LLE, that holds promise of obviating any requirement for the components of the present system: absorbed organ dose, LET, a standard radiation, REB(Q), dose equivalent and rem. 12 refs., 11 figs.

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

    PubMed

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

    2013-08-01

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

  1. 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,...

  2. Radiation exposures for DOE and DOE contractor employees, 1979. Twelfth annual report

    SciTech Connect

    Not Available

    1980-12-01

    This report includes: standards for radiation protection; whole body radiation exposures by general trends, dose equivalent distributions, and average dose equivalent ratios; internal exposures; worker terminations; whole body dose equivalents greater than 5 Rem; and Appendices of distribution of annual whole body exposures by facility type, by contractor; and by DOE field organization.

  3. Polychlorinated biphenyl exposure and human disease.

    PubMed

    James, R C; Busch, H; Tamburro, C H; Roberts, S M; Schell, J D; Harbison, R D

    1993-02-01

    Polychlorinated biphenyls (PCBs) continue to be of great environmental and occupational health interest. This review summarizes the major clinical findings reported in individuals incurring the greatest PCB exposure--those persons working in the manufacture or repair of electrical capacitors or transformers. The potential target organs addressed in the studies reviewed include the liver, lungs, skin, cardiovascular system, nervous system, certain endocrine systems, the blood/immune system, and the gastrointestinal and urinary tracts. After careful analysis, the weight of evidence suggests the only adverse health effects attributable to high, occupational PCB exposures are dermal. This review confirms and extends the observations of others, ie, that the collective occupational experience with PCB fluids provides no evidence for adverse PCB effects on any other organ systems. PMID:8433185

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

    SciTech Connect

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

    2008-04-01

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

  5. Medical Diagnostic Radiation Exposures and Risk of Gliomas

    PubMed Central

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

    2011-01-01

    High-dose ionizing radiation is an established risk factor for glioma, but it remains unknown whether moderate- and low-dose radiation increase glioma risk. In this analysis, we assessed the evidence that self-reported exposures to diagnostic ionizing radiation, including computerized tomography (CT) scans, is associated with increased risk of adult glioma. While no independent association was observed for CT scans alone (3+ scans compared to none P = 0.08 and 1–2 scans compared to none P = 0.68), our findings suggest an increased risk of adult gliomas with cumulative exposure to three or more CT scans to the head and neck region (OR = 1.97, 95% CI: 0.92–4.23) limited to those who reported a family history of cancer: the P value for the interaction between having three or more CT scans and family history of cancer was 0.08. The stratum-specific adjusted OR for those with family history of cancer was more than three times that for the sub-group without family history of cancer. While there is some potential for symptom-related bias, one might expect this to be present for all diagnostic procedures rather than specific to one procedure. The interaction between CT scans and glioma with family history of cancer supports the biological plausibility of our findings, because similar results have been found for breast cancer and radiation. This observational data will increase awareness about potential risks associated with CT scans and the need to minimize the use of unnecessary examinations. PMID:21466382

  6. Recovery after exposure to high LET-radiation.

    PubMed

    Kiefer, J

    1984-01-01

    In many cellular systems the shape of survival curves is changed from a sigmoidal to a purely exponential type if the LET of the radiation is increased. This is often explained by the hypothesis that repair mechanisms are less effective or non-functional with lesions generated by densely ionizing radiation. The absence of split-dose sparing and/or recovery from potentially lethal damage is then taken as further support. A careful consideration has to take into account, however, that with particle exposure the pattern of energy deposition varies considerably within a cell population and that the actual distribution depends also on cell geometry. If one accepts the view that with low-LET radiations repair may be saturated at high dose, the survival curve shape characteristic of high LET may be explained by the assumption that in this case saturation may occur due to the energy deposited by one or few heavy charged particles. The absence of recovery would then be due to microdosimetric parameters rather than to the nature or pattern of the primary molecular lesions. This alternative can be tested quantitatively by comparative analysis of the survival behaviour of different cellular systems exposed to radiations of varying LET. Our experiments with yeast strains of different sensitivities show that recovery from potentially lethal damage can be demonstrated even after exposure to uranium ions. Quantitative analysis leads to the conclusion that the apparent reduction in the extent of recovery is mostly due to saturation at the cellular level rather than to non-reparability of the primary lesions or to destruction of the repair system. PMID:6365137

  7. Human In vivo Radiation-Induced Biomarkers: Gene Expression Changes in Radiotherapy Patients

    Microsoft Academic Search

    Sally A. Amundson; Marcy B. Grace; Christopher B. Mcleland; Michael W. Epperly; Andrew Yeager; Qimin Zhan; Joel S. Greenberger; Albert J. Fornace

    2004-01-01

    Abstract After initially identifying potential biomarkers of radiation exposure through microarray studies of ex vivo irradiated human peripheral white blood cells, we have now measured the in vivo responses of several of these biomarker genes in patients undergoing total body irradiation. Microar- ray analysis has identified additional in vivo radiation-responsive genes, although the general in vivo patterns of stress-gene induction

  8. Exposure to radio-frequency radiation from an aircraft radar unit

    SciTech Connect

    Williams, R.A.; Webb, T.S.

    1980-11-01

    The case is reported when two airmen were exposed to radio-frequency radiation thirty-eight times above the Air Force permissible level. Medical evaluation showed initial anxiety and hypertensions, which resolved with therapy. It is noted that the body organs least able to dissipate heat are the organs most susceptible to microwave radiation, such as eyes and testicles. Except for the eyes, the sensation of warmth provides a warning mechanism. Exposure standards for microwave radiation in the United States are compared with those in the Soviet Union. The Soviet Union uses more stringent standards of 1-2.5 mW/sq cm, that include shorter wavelengths which produce no heating. These 'athermal' effects, the USSR reported, include headaches, fatigue, and behavioral changes in humans and animals.

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

    PubMed Central

    Ron, Elaine; Brenner, Alina

    2013-01-01

    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

  10. On the Use of SRIM for Computing Radiation Damage Exposure

    SciTech Connect

    Stoller, Roger E. [Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Div.; Toloczko, Mychailo B. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Was, Gary S. [Univ. of Michigan, Ann Arbor, MI (United States). Nuclear Engineering and Radiological Sciences; Certain, Alicia G. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Dwaraknath, S. [Univ. of Michigan, Ann Arbor, MI (United States). Nuclear Engineering and Radiological Sciences; Garner, Frank A. [Radiation Effects Consulting, Richland, WA (United States)

    2013-09-01

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

  11. On the use of SRIM for computing radiation damage exposure

    NASA Astrophysics Data System (ADS)

    Stoller, R. E.; Toloczko, M. B.; Was, G. S.; Certain, A. G.; Dwaraknath, S.; Garner, F. A.

    2013-09-01

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

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

    PubMed Central

    2012-01-01

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

  13. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers

    PubMed Central

    Mortazavi, SMJ; Parsanezhad, ME; Kazempour, M; Ghahramani, P; Mortazavi, AR; Davari, M

    2013-01-01

    BACKGROUND: Modern life prompted man to increasingly generate, transmit and use electricity that leads to exposure to different levels of electromagnetic fields (EMFs). Substantial evidence indicates that exposure to common sources of EMF such as mobile phones, laptops or wireless internet-connected laptops decreases human semen quality. In some countries, mobile jammers are occasionally used in offices, shrines, conference rooms and cinemas to block the signal. AIMS: To the best of our knowledge, this is the first study to investigate the effect of short term exposure of human sperm samples to radiofrequency (RF) radiations emitted by common mobile jammers. SUBJECTS AND METHODS: Fresh semen samples were collected by masturbation from 30 healthy donors who had referred to Infertility Treatment Center at the Mother and Child Hospital with their wives. Female problem was diagnosed as the reason for infertility in these couples. STATISTICAL ANALYSIS: T-test and analysis of variance were used to show statistical significance. RESULTS: The motility of sperm samples exposed to jammer RF radiation for 2 or 4 h were significantly lower than those of sham-exposed samples. These findings lead us to the conclusion that mobile jammers may significantly decrease sperm motility and the couples’ chances of conception. CONCLUSION: Based on these results, it can be suggested that in countries that have not banned mobile jammer use, legislations should be urgently passed to restrict the use of these signal blocking devices in public or private places. PMID:24082653

  14. HUMAN HEALTH IMPACTS OF EXPOSURE TO POPS

    EPA Science Inventory

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

  15. Stromal Modulation of Radiation Carcinogenesis in Breast Cancer

    E-print Network

    Nguyen, David Hiendat Hua

    2011-01-01

    human exposures, we focused subsequent radiation-chimera experimentstumors of the radiation chimera experiments to human breastradiation chimera experiments and compares them to gene expression profiles of human

  16. Occupational exposure to natural UV radiation and premature skin ageing.

    PubMed

    Lastowiecka-Moras, El?bieta; Bugajska, Joanna; M?ynarczyk, Beata

    2014-01-01

    The skin is the part of the human body most vulnerable to ultraviolet (UV) radiation. The spectrum of the negative effects of UV radiation on the skin ranges from acute erythema to carcinogenesis. Between these extreme conditions, there are other common skin lesions, e.g., photoageing. The aim of this study was to assess the skin for signs of photoageing in a group of 52 men occupationally exposed to natural UV radiation. There were 2 types of examinations: an examination of skin condition (moisture, elasticity, sebum, porosity, smoothness, discolourations and wrinkles) with a device for diagnosing the skin, and a dermatological examination. The results of both examinations revealed a higher percentage of skin characteristics typical for photoageing in outdoor workers compared to the general population. PMID:25513799

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

    PubMed

    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

    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

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

    PubMed Central

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

    2009-01-01

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

  19. Dose-Response Relationships in Human Experimental Exposure to Solvents

    PubMed Central

    Iavicoli, Ivo; Carelli, Giovanni; Marinaccio, Alessandro

    2006-01-01

    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

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

    EPA Science Inventory

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

  1. 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...

  2. Human exposure to pet prescription medications.

    PubMed

    Bryant, Sean M; Mycyk, Mark B

    2002-08-01

    Veterinarians commonly prescribe medications to treat a variety of companion animal clinical conditions. Many pet medications are pharmacologically the same product prescribed for human use. We report 2 cases in which pet medications were used for self poisoning. Obtaining a pet history may provide critical information in the assessment of a patient with a suspected overdose. PMID:12136968

  3. 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...

  4. 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...

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

    SciTech Connect

    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

    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.

  6. Mitigation of lung injury after accidental exposure to radiation.

    PubMed

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

    2011-12-01

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

  7. Therapeutic and space radiation exposure of mouse brain causes impaired DNA repair response and premature senescence by chronic oxidant production

    PubMed Central

    Suman, Shubhankar; Rodriguez, Olga C.; Winters, Thomas A.; Fornace, Albert J.; Albanese, Chris; Datta, Kamal

    2013-01-01

    Despite recent epidemiological evidences linking radiation exposure and a number of human ailments including cancer, mechanistic understanding of how radiation inflicts long-term changes in cerebral cortex, which regulates important neuronal functions, remains obscure. The current study dissects molecular events relevant to pathology in cerebral cortex of 6 to 8 weeks old female C57BL/6J mice two and twelve months after exposure to a ? radiation dose (2 Gy) commonly employed in fractionated radiotherapy. For a comparative study, effects of 1.6 Gy heavy ion56Fe radiation on cerebral cortex were also investigated, which has implications for space exploration. Radiation exposure was associated with increased chronic oxidative stress, oxidative DNA damage, lipid peroxidation, and apoptosis. These results when considered with decreased cortical thickness, activation of cell-cycle arrest pathway, and inhibition of DNA double strand break repair factors led us to conclude to our knowledge for the first time that radiation caused aging-like pathology in cerebral cortical cells and changes after heavy ion radiation were more pronounced than ? radiation. PMID:23928451

  8. Solar UV radiation reduces the barrier function of human skin

    PubMed Central

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

    2012-01-01

    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

  9. Solar UV radiation reduces the barrier function of human skin.

    PubMed

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

    2012-10-16

    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

  10. Further studies of 60 Hz exposure effects on human function

    SciTech Connect

    Graham, C.

    1990-07-20

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

  11. Further studies of 60 Hz exposure effects on human function

    SciTech Connect

    Graham, C.; Cohen, H.D.

    1990-10-09

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

  12. Infrared-A Radiation-Induced Matrix Metalloproteinase 1 Expression is Mediated Through Extracellular Signal-regulated Kinase 1\\/2 Activation in Human Dermal Fibroblasts

    Microsoft Academic Search

    Stefan M Schieke; Helger Stege; Viola Kürten; Susanne Grether-Beck; Helmut Sies; Jean Krutmann

    2002-01-01

    In addition to ultraviolet radiation, human skin is exposed to infrared radiation from natural sunlight as well as artificial ultraviolet and infrared irradiation devices used for therapeutic or cosmetic purposes. The molecular consequences resulting from infrared exposure are virtually unknown. In this study we have investigated whether infrared has the capacity to affect gene expression in human skin cells. Exposure

  13. Tyrosine/Cysteine Cluster Sensitizing Human ?D-Crystallin to Ultraviolet Radiation-Induced Photoaggregation in Vitro

    E-print Network

    Schafheimer, Steven Nathaniel

    Ultraviolet radiation (UVR) exposure is a major risk factor for age-related cataract, a protein-aggregation disease of the human lens often involving the major proteins of the lens, the crystallins. ?D-Crystallin (H?D-Crys) ...

  14. Occupational Radiation Exposure Analysis of US ITER DCLL TBM

    SciTech Connect

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

    2007-08-01

    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.

  15. Radiation exposure and the risk of pediatric thyroid cancer.

    PubMed

    Miyakawa, Megumi

    2014-07-01

    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

  16. Radiation Exposure and the Risk of Pediatric Thyroid Cancer

    PubMed Central

    Miyakawa, Megumi

    2014-01-01

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

  17. 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 ...

  18. Assessment of human exposure level to PM10 in China

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

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

  19. Airborne acidity: estimates of exposure and human health effects.

    PubMed Central

    Lippmann, M

    1985-01-01

    Human health effects have resulted from the inhalation of ambient acidic aerosols, and there is suggestive evidence that current North American levels of exposure are producing excesses in respiratory morbidity. Annual mean mortality rates have been correlated with ambient aerosol concentration indices, with SO4(2-), FP, IP, and TSP having a descending order as predictive coefficients. These pollutant indices also contain H+ in descending mass ratios, and may all be surrogates for H+ as an active agent. Controlled exposure studies in humans and animals provide evidence that acidic aerosols produce greater changes in respiratory mechanical function and rates of particle clearance than other constituents of ambient particulate matter. The strong acid content of the ambient aerosol has not been measured in any of the population based pollutant effects studies in which it is a likely causal factor. The absence of direct measurement data on acidic aerosol in these studies, and their reliance on surrogate indices such as SO2 and SO4(2-), precludes firm conclusions about exposure-response relationships. High priority areas for further investigation include systematic investigation of the spatial and temporal distribution of population exposures; extension and refinement of population response studies in relation to acid aerosol exposures; responses of normal healthy and asthmatic human volunteers to mixtures of acidic aerosols and oxidant vapors under controlled conditions of exposure and exercise intensity; and progression of changes in lung epithelia during repetitive daily exposures of experimental animals to acidic aerosols, oxidants, and their mixtures, with concurrent measurements of particle clearance and respiratory function. PMID:4076095

  20. Thermal steady state in human head under continuous EM exposure

    Microsoft Academic Search

    Woo-Tae Kim; Jong-Gwan Yook

    2005-01-01

    The bio-heat equation including the thermoregulatory systems is solved for an anatomically based model of the human head with a resolution of 3 × 3 × 3 mm. In order to study the capability of thermal homeostasis of numerical head model, the time to reach the thermal steady-state under continuous RF exposure has been examined with the variation of power

  1. Assessment of human exposure to chemical contaminants in foods

    Microsoft Academic Search

    H. B. S. Conacher; J. Mes

    1993-01-01

    One of the most important factors in assessing risk to human health from potentially harmful chemicals in foods is the availability of good data on the exposure of the public to such substances. The means of acquiring these data generally involves monitoring programmes using appropriate sampling procedures and reliable analytical methods for measuring the compounds of concern in a variety

  2. Dietary mercury intake and human exposure in an Adriatic population

    Microsoft Academic Search

    R. Buzina; P. Stegnar; K. Buzina-Suboticanec; M. Horvat; I. Petric; T. M. M. Farley

    1995-01-01

    A study was conducted to examine human exposure to mercury through dietary mercury intake in a population living in an industrially non-polluted area of the Adriatic Sea. The results have shown that ? 20% of the subjects had a weekly dietary mercury intake above the provisional tolerable weekly intake (PTWI), primarily those consuming fish and other seafood > 6 times\\/week.

  3. 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...

  4. Development of a urinary biomarker of human exposure to deoxynivalenol

    Microsoft Academic Search

    F. A Meky; P. C Turner; A. E Ashcroft; J. D Miller; Y.-L Qiao; M. J Roth; C. P Wild

    2003-01-01

    Deoxynivalenol (DON) is a mycotoxin frequently found as a contaminant of cereal crops and may be etiologically associated with adverse health effects in developing countries where considerable quantities of contaminated crops are consumed. We investigated the metabolism of DON in rats as a basis to establish methodology for a candidate biomarker of human exposure to this toxin and tested this

  5. Pulse exposure to ionizing radiation elicits rapid changes in cellular radiosensitivity.

    PubMed

    Ponette, V; Giocanti, N; Tourbez, H; Balosso, J; Hennequin, C; Favaudon, V

    1996-06-01

    A linear electron accelerator, operated in a recurrent chopped mode, was used for time-resolved investigation of split-dose radiation recovery in 3 mammalian cell lines in vitro. The time intervals separating the sequential radiation exposures in this study ranged from fractions of a second to a few minutes. The primary pulse brought about rapid, synchronous oscillations of cellular radiosensitivity giving rise to a tetraphasic, W-shaped time-dependent profile whose first phase was accomplished by a large decrease of cell survival. Only the last phase correlated with sub-lethal damage repair determined by gamma-ray irradiation. The same profile was observed for the 3 cell lines investigated. However, the kinetics of the whole process varied extensively from one cell line to another. The first phase lasted 1 s only for Chinese hamster V79 fibroblasts, 6 s for human squamous carcinoma SQ20B cells, and as much as 25 s for human colon adenocarcinoma LoVo cells. The relative amplitude of this first phase grew with both the first and second radiation doses in the range explored. It is hypothesized that rapid oscillation of the cytotoxic potential of radiation may result from various mechanisms such as molecular recognition of radio-induced lesions, changes in chromatin structure, or differential activation of phospholipid-dependent transduction pathways. PMID:8881284

  6. TOPICAL REVIEW: Climate change, ozone depletion and the impact on ultraviolet exposure of human skin

    NASA Astrophysics Data System (ADS)

    Diffey, Brian

    2004-01-01

    For 30 years there has been concern that anthropogenic damage to the Earth's stratospheric ozone layer will lead to an increase of solar ultraviolet (UV) radiation reaching the Earth's surface, with a consequent adverse impact on human health, especially to the skin. More recently, there has been an increased awareness of the interactions between ozone depletion and climate change (global warming), which could also impact on human exposure to terrestrial UV. The most serious effect of changing UV exposure of human skin is the potential rise in incidence of skin cancers. Risk estimates of this disease associated with ozone depletion suggest that an additional peak incidence of 5000 cases of skin cancer per year in the UK would occur around the mid-part of this century. Climate change, which is predicted to lead to an increased frequency of extreme temperature events and high summer temperatures, will become more frequent in the UK. This could impact on human UV exposure by encouraging people to spend more time in the sun. Whilst future social trends remain uncertain, it is likely that over this century behaviour associated with climate change, rather than ozone depletion, will be the largest determinant of sun exposure, and consequent impact on skin cancer, of the UK population.

  7. Development of a method for assessing non-targeted radiation damage in an artificial 3D human skin model

    E-print Network

    Brenner, David Jonathan

    Development of a method for assessing non-targeted radiation damage in an artificial 3D human skin experiments, the method focuses on analysing radiation damage in individual cells as a function 0.5 Gy and non-targeted exposures of ionising radiation on living organisms, the majority

  8. Dose-dependent micronuclei formation in normal human fibroblasts exposed to proton radiation.

    PubMed

    Litvinchuk, Alexandra V; Vachelová, J; Michaelidesová, A; Wagner, R; Davídková, M

    2015-08-01

    Micronuclei are small extranuclear bodies resulting from chromosome fragments or the whole chromosomes secluded from daughter nuclei during mitosis. The number of radiation-induced micronuclei reflects the level of chromosomal damage and relates to an absorbed dose and quality of incident ionizing radiation. The aim of the present study was to determine the micronucleus formation as a specific biological marker for acute radiation-induced DNA damage in normal human fibroblasts exposed to 30-MeV protons and Co-60 gamma radiation. We found a linear increase in binuclear cells containing micronuclei for absorbed doses from 1 to 5 Gy for both radiation modalities. However, the total number of micronuclei in binuclear cells follows a linear-quadratic dose dependence. In case of human exposure to mixed radiation fields or high LET radiation, the proportion of binuclear cells containing micronuclei from all binuclear cells can thus serve as a good biomarker of radiation-induced DNA damage. PMID:25972267

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

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

    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.

  11. Optically Stimulated Luminescence (OSL) of dental enamel for retrospective assessment of radiation exposure

    PubMed Central

    Yukihara, E.G.; Mittani, J.; McKeever, S.W.S.; Simon, S.L.

    2009-01-01

    This paper briefly reviews the optically stimulated luminescence (OSL) properties of dental enamel and discusses the potential and challenges of OSL for filling the technology gap in biodosimetry required for medical triage following a radiological/nuclear accident or terrorist event. The OSL technique uses light to stimulate a radiation-induced luminescence signal from materials previously exposed to ionizing radiation. This luminescence originates from radiation-induced defects in insulating crystals and is proportional to the absorbed dose of ionizing radiation. In our research conducted to date, we focused on fundamental investigations of the OSL properties of dental enamel using extracted teeth and tabletop OSL readers. The objective was to obtain information to support the development of the necessary instrumentation for retrospective dosimetry using dental enamel in laboratory, or for in situ and non-invasive accident dosimetry using dental enamel in emergency triage. An OSL signal from human dental enamel was detected using blue, green, or IR stimulation. Blue/green stimulation associated with UV emission detection seems to be the most appropriate combination in the sense that there is no signal from un-irradiated samples and the shape of the OSL decay is clear. Improvements in the minimum detection level were achieved by incorporating an ellipsoidal mirror in the OSL system to maximize light collection. Other possibilities to improve the sensitivity and research steps necessary to establish the feasibility of the technique for retrospective assessment of radiation exposure are also discussed. PMID:19623269

  12. Long-term differential changes in mouse intestinal metabolomics after ? and heavy ion radiation exposure.

    PubMed

    Cheema, Amrita K; Suman, Shubhankar; Kaur, Prabhjit; Singh, Rajbir; Fornace, Albert J; Datta, Kamal

    2014-01-01

    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 ??Fe (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 ??Fe radiation preferentially altered dipeptide metabolism. Furthermore, ??Fe 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

  13. 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

    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

    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

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

    Microsoft Academic Search

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

    2006-01-01

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

  15. Assessing sources of human methylmercury exposure using stable mercury isotopes.

    PubMed

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

    2014-01-01

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

  16. Assessing Sources of Human Methylmercury Exposure Using Stable Mercury Isotopes

    PubMed Central

    2015-01-01

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

  17. Human exposures to monomers resulting from consumer contact with polymers.

    PubMed

    Leber, A P

    2001-06-01

    Many consumer products are composed completely, or in part, of polymeric materials. Direct or indirect human contact results in potential exposures to monomers as a result of migrations of trace amounts from the polymeric matrix into foods, into the skin or other bodily surfaces. Typically, residual monomer levels in these polymers are <100 p.p.m., and represent exposures well below those observable in traditional toxicity testing. These product applications thus require alternative methods for evaluating health risks relating to monomer exposures. A typical approach includes: (a) assessment of potential human contacts for specific polymer uses; (b) utilization of data from toxicity testing of pure monomers, e.g. cancer bioassay results; and (c) mathematical risk assessment methods. Exposure potentials are measured in one of two analytical procedures: (1) migration of monomer from polymer into a simulant solvent (e.g. alcohol, acidic water, vegetable oil) appropriate for the intended use of the product (e.g. beer cans, food jars, packaging adhesive, dairy hose); or (2) total monomer content of the polymer, providing worse-case values for migratable monomer. Application of toxicity data typically involves NOEL or benchmark values for non-cancer endpoints, or tumorigenicity potencies for monomers demonstrated to be carcinogens. Risk assessments provide exposure 'safety margin' ratios between levels that: (1) are projected to be safe according to toxicity information, and (2) are potential monomer exposures posed by the intended use of the consumer product. This paper includes an example of a health risk assessment for a chewing gum polymer for which exposures to trace levels of butadiene monomer occur. PMID:11397392

  18. Human health risk assessment from arsenic exposures in Bangladesh.

    PubMed

    Joseph, Tijo; Dubey, Brajesh; McBean, Edward A

    2015-09-15

    High arsenic exposures, prevalent through dietary and non-dietary sources in Bangladesh, present a major health risk to the public. A quantitative human health risk assessment is described as a result of arsenic exposure through food and water intake, tea intake, accidental soil ingestion, and chewing of betel quid, while people meet their desirable dietary intake requirements throughout their lifetime. In evaluating the contribution of each intake pathway to average daily arsenic intake, the results show that food and water intake combined, makes up approximately 98% of the daily arsenic intake with the balance contributed to by intake pathways such as tea consumption, soil ingestion, and quid consumption. Under an exposure scenario where arsenic concentration in water is at the WHO guideline (0.01mg/L), food intake is the major arsenic intake pathway ranging from 67% to 80% of the average daily arsenic intake. However, the contribution from food drops to a range of 29% to 45% for an exposure scenario where arsenic in water is at the Bangladesh standard (0.05mg/L). The lifetime excess risk of cancer occurrence from chronic arsenic exposure, considering a population of 160 million people, based on an exposure scenario with 85 million people at the WHO guideline value and 75 million people at the Bangladesh standard, and assuming that 35 million people are associated with a heavy activity level, is estimated as 1.15 million cases. PMID:26006052

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

    PubMed

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

    1994-01-01

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

  20. Parabens as Urinary Biomarkers of Exposure in Humans

    PubMed Central

    Ye, Xiaoyun; Bishop, Amber M.; Reidy, John A.; Needham, Larry L.; Calafat, Antonia M.

    2006-01-01

    Background Parabens appear frequently as antimicrobial preservatives in cosmetic products, in pharmaceuticals, and in food and beverage processing. In vivo and in vitro studies have revealed weak estrogenic activity of some parabens. Widespread use has raised concerns about the potential human health risks associated with paraben exposure. Objectives Assessing human exposure to parabens usually involves measuring in urine the conjugated or free species of parabens or their metabolites. In animals, parabens are mostly hydrolyzed to p-hydroxybenzoic acid and excreted in the urine as conjugates. Still, monitoring urinary concentrations of p-hydroxybenzoic acid is not necessarily the best way to assess exposure to parabens. p-Hydroxybenzoic acid is a nonspecific biomarker, and the varying estrogenic bioactivities of parabens require specific biomarkers. Therefore, we evaluated the use of free and conjugated parent parabens as new biomarkers for human exposure to these compounds. Results We measured the urinary concentrations of methyl, ethyl, n-propyl, butyl (n- and iso-), and benzyl parabens in a demographically diverse group of 100 anonymous adults. We detected methyl and n-propyl parabens at the highest median concentrations (43.9 ng/mL and 9.05 ng/mL, respectively) in nearly all (> 96%) of the samples. We also detected other parabens in more than half of the samples (ethyl, 58%; butyl, 69%). Most important, however, we found that parabens in urine appear predominantly in their conjugated forms. Conclusions The results, demonstrating the presence of urinary conjugates of parabens in humans, suggest that such conjugated parabens could be used as exposure biomarkers. Additionally, the fact that conjugates appear to be the main urinary products of parabens may be important for risk assessment. PMID:17185273

  1. DIET AS A FACTOR IN BEHAVIORAL RADIATION PROTECTION FOLLOWING EXPOSURE TO HEAVY PARTICLES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Major risks associated with radiation exposures on deep space missions include carcinogenesis due to heavy-particle exposure of cancer-prone tissues and performance decrements due to neurological damage produced by heavy particles. Because exposure to heavy particles can cause oxidative stress, it ...

  2. An international comparison of models and approaches for the estimation of the radiological exposure of non-human biota

    Microsoft Academic Search

    Nicholas A. Beresford; Mikhail Balonov; Karine Beaugelin-Seiller; Justin Brown; David Copplestone; Joanne L. Hingston; Jan Horyna; Ali Hosseini; Brenda J. Howard; Sunita Kamboj; Tatjana Nedveckaite; Geert Olyslaegers; Tatiana Sazykina; Jordi Vives i Batlle; Tamara L. Yankovich; Charley Yu; SCK CEN; SPA-Typhoon

    2008-01-01

    Over the last decade a number of models and approaches have been developed for the estimation of the exposure of non-human biota to ionising radiations. In some countries these are now being used in regulatory assessments. However, to date there has been no attempt to compare the outputs of the different models used. This paper presents the work of the

  3. The association between exposure determined by radiofrequency personal exposimeters and human exposure: a simulation study.

    PubMed

    Neubauer, Georg; Cecil, Stefan; Giczi, Wolfram; Petric, Benjamin; Preiner, Patrick; Fröhlich, Jürg; Röösli, Martin

    2010-10-01

    The selection of an adequate exposure assessment approach is imperative for the quality of epidemiological studies. The use of personal exposimeters turned out to be a reasonable approach to determine exposure profiles, however, certain limitations regarding the absolute values delivered by the devices have to be considered. Apart from the limited dynamic range, it has to be taken into account that these devices give only an approximation of the exposure due to the influence of the body of the person carrying the exposimeter, the receiver characteristics of the exposimeter, as well as the dependence of the measured value on frequency band, channel, slot configuration, and communication traffic. In this study, the relationship between the field strength measured close to the human body at the location of the exposimeter and the exposure, that is, the field strength at the location of the human body without the human body present, is investigated by numerical means using the Visible Human model as an anatomical phantom. Two different scenarios were chosen: (1) For FM, GSM, and UMTS an urban outdoor scenario was examined that included a transmitting antenna mounted on the roof of one of four buildings at a street crossing, (2) For WLAN an indoor scenario was investigated. For GSM the average degree of underestimation by the exposimeter (relation of the average field levels at the location of the exposimeter to the field level averaged over the volume of the human body without the body present) was 0.76, and for UMTS 0.87; for FM no underestimation was found, the ratio was 1. In the case of WLAN the degree of underestimation was more pronounced, the ratio was 0.64. This study clearly suggests that a careful evaluation of correction factors for different scenarios is needed prior to the definition of the study protocol. It has to be noted that the reference scenario used in this study does not allow for final conclusions on general correction factors. PMID:20564178

  4. Radiation and human health. [Lead abstract

    Microsoft Academic Search

    Gofman

    1981-01-01

    Separate abstracts were written for each of the 22 chapters of this book which present and analyze the evidence concerning effects of low doses of radiation upon humans. An extensive bibliography with over 300 references and an appendix with basic mathematical concepts are included. (KRM)

  5. Human radiation experiments: Looking beyond the headlines

    Microsoft Academic Search

    1994-01-01

    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

  6. Induction of Interleukin6 Production by Ultraviolet Radiation in Normal Human Epidermal Keratinocytes and in a Human Keratinocyte Cell Line is Mediated by DNA Damage

    Microsoft Academic Search

    Corinner Petit-Frère; Peter H Clingen; Markus Grewe; Jean Krutmann; Len Roza; Colin F Arlett; Michael H L Green; C. Pretit-Frère

    1998-01-01

    The sunburn reaction is the most common consequence of human exposure to ultraviolet radiation (UVR), and is mediated at least in part by interleukin-6 (IL-6). The aim of this study was to determine if DNA is a major chromophore involved in the induction of IL-6 following UV irradiation of a human epidermoid carcinoma cell line (KB), and of normal human

  7. Radiation studies inside a human phantom using the MATROSHKA facility

    NASA Astrophysics Data System (ADS)

    Reitz, G.

    MATROSHKA is an ESA-Multi-User facility for studies of the depth dose distribution of the different components of the orbital radiation field at different sides of the organs, occurring in human being exposed during an EVA (Extra Vehicular Activity) to cosmic radiation. MATROSHKA provides a pressurized housing for a human phantom equipped with passive and active experiment packages and for the electronics for experiment and housekeeping data acquisition, storage and transfer to the onboard data management system. Several institutes from Europe, Japan and US contribute to the radiation measurement program. The facility was launched on Jan 30, 2004 with PROGRESS, and installed during an EVA on February 26 at an external platform of the Russian Service Module (RSM). After several in-orbit tests the facility is planned to be activated for nominal operations mid April 2004. Data will than be transmitted to ground regularly during the mission. After the exposure time of one year the facility will be brought back to inside the RSM, where the passive experiments will be reinstalled and transported back to ground by Soyuz. The facility remains for further use inside the RSM. A detailed description of the facility and the radiation detectors including their final layout inside and around the phantom will be presented. The inclusion of first data of the active experiments in this report depends on availability.

  8. Human Physiological Responses to Acute and Chronic Cold Exposure

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    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.

  9. Monitoring exposure to atomic bomb radiation by somatic mutation

    SciTech Connect

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

    1996-05-01

    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.

  10. Radiation risk and human space exploration

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  11. Radiation exposure to the pediatric patient during cardiac catheterization and angiocardiography. Emphasis on the thyroid gland

    SciTech Connect

    Martin, E.C.; Olson, A.P.; Steeg, C.N.; Casarella, W.J.

    1981-07-01

    Thermoluminescent dosimetry was used to measure the radiation exposure to the skin, thyroid and gonads in 50 consecutive pediatric patients undergoing cardiac catheterization and angiocariography using cine photofluorography. Average exposures were 17.1 R to the skin, 2.3 R to the thyroid and 0.1 R to the gonads. Fluoroscopy accounted for approximately 80% of the skin and thyroid exposure and cine photofluorography for 20 to 25%. Occasional primary-beam irradiation was the major contributor to gonad exposure. Internal scatter of the incident x-ray beam was primarily responsible for thyroid exposure, so that infants received relatively high exposures; one receiving 7.3 R. The thyroid was not frequently in the primary beam. The significance of high radiation exposure to the thyroid, and in particular its relationship to thyroid carcinoma, are discussed. The results are compared with other series in the literature and relative exposures of cine photofluorography and serial filming are contrasted.

  12. AN OVERVIEW OF THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) PHASE I STUDIES

    EPA Science Inventory

    The National Human Exposure Assessment Survey (NHEXAS) Phase I studies were sponsored by EPA's Office of Research and Development (ORD) to address critical information needs for assessing human exposures to multiple chemicals from multiple pathways and media. These studies were...

  13. The Growing Public Health Challenges of Exposure to Ultraviolet Radiation From Use of Indoor Tanning Devices in the United States.

    PubMed

    Bowman, Diana M; Lewis, Ryan C; Lee, Maximilian S; Yao, Catherine J

    2015-08-01

    Ultraviolet radiation is recognized as a human carcinogen by the International Agency for Research on Cancer, the world's authority on cancer research. In particular, exposure to ultraviolet radiation can lead to melanoma of the skin, which is the deadliest form of skin cancer in the United States. Yet despite the significant public health burden that is associated with skin cancer in the United States, each year over a million Americans engage in indoor tanning where exposure to artificial ultraviolet radiation occurs. In this article, we argue for an immediate ban on the use of commercial indoor tanning by minors and, based on international precedents, the phasing out of all commercial tanning operations in the United States. We consider the use of indoor tanning devices in the United States, epidemiological data on indoor tanning devices and cancer, regulation of tanning devices, and scientific evidence for increased government intervention. PMID:25995373

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

    SciTech Connect

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

    1990-01-01

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

  15. Polonium in cigarette smoke and radiation exposure of lungs

    NASA Astrophysics Data System (ADS)

    Carvalho, Fernando P.; Oliveira, João M.

    2006-01-01

    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.

  16. Case Report: Human Exposure to Dioxins from Clay

    PubMed Central

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

    2008-01-01

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

  17. Techniques for Minimizing Radiation Exposure During Evaluation, Surgical Treatment, and Follow-up of Urinary Lithiasis.

    PubMed

    Arenas, Javier L; Baldwin, D Duane

    2015-07-01

    Patients receive significant radiation exposure during the diagnosis, treatment, and follow-up of urinary stone disease. This radiation exposure may result in patient harm and is believed to contribute to the risk for malignancy. This review will present current information to allow surgeons to optimize their diagnostic, treatment, and follow-up regimens to allow optimal care of stone disease patients at the lowest radiation dose possible. PMID:26025493

  18. Space radiation protection: Human support thrust exploration technology program

    NASA Technical Reports Server (NTRS)

    Conway, Edmund J.

    1991-01-01

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

  19. Measurements of indoor radon concentrations and assessment of radiation exposure

    NASA Astrophysics Data System (ADS)

    Medici, F.; Rybach, L.

    1994-02-01

    In the past decade many international studies have established that the radioactive gas radon is responsible to a large extent for the radiation dose absorbed by the population. Consequently the Swiss Federal Health Office started and sponsored a research program called RAPROS (Radon Programm Schweiz, 1987-1991) to assess the relevant aspects of radon exposure in Switzerland. The average indoor radon concentration in Swiss living rooms is about 60-70 Bq m -3, this corresponds to an annual dose of about 2.2 mSv, but values largely exceeding 1000 Bq m -3 were also found. Often very strong temporal fluctuations of indoor radon concentrations were measured. The ground directly underneath buildings is the main radon source of indoor radon. The material properties that influence the radon production and transport in soils are: radium content, emanating coefficient and soil gas permeability; among them only the last one can vary over many orders of magnitude. The permeability is consequently the decisive factor that enables radon transport in the subsurface. To characterize the radon potential of soils a radon availability index ( RAV) was introduced. Our investigations have also shown that in karst systems the radon concentration in the air is often increased to 10-100 times higher than in buildings. This radon-charged air is able to travel over considerable distances through faults and cavities in the underground and reach living rooms built over karstified areas.

  20. Measurement of radiation exposure of astronauts by radiochemical techniques

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.

    1972-01-01

    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.

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

    PubMed

    Brent, Robert L

    2015-02-01

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

  2. Human exposure to PBDE and critical evaluation of health hazards.

    PubMed

    Linares, Victoria; Bellés, Montserrat; Domingo, José L

    2015-03-01

    Polybrominated diphenyl ethers (PBDEs) are used in large quantities as flame-retardant additives in a number of commercial products. Biomonitoring data show that, in recent years, PBDE concentrations have increased rapidly in the bodies of wildlife and humans. Usually, PBDE levels in North America have been reported to be higher than those in Europe and Asia. Moreover, body burden of PBDEs is three- to ninefold higher in infants and toddlers than in adults, showing these last two age groups the highest levels of these compounds, due to exposure via maternal milk and through dust. Tetra-, Penta-, and Hexa-BDEs are the isomers most commonly found in humans. Based on studies on experimental animals, the toxicological endpoints of exposure to PBDEs are likely to be thyroid homeostasis disruption, neurodevelopmental deficits, reproductive changes, and even cancer. Experimental studies in animals and epidemiological observations in humans suggest that PBDEs may be developmental neurotoxicants. Pre- and/or postnatal exposure to PBDEs may cause long-lasting behavioral abnormalities, particularly on motor activity and cognition. This paper is focused on reviewing the current status of PBDEs in the environment, as well as the critical adverse health effects based on the recent studies on the toxic effects of PBDEs. PMID:25637414

  3. Satellite nighttime lights reveal increasing human exposure to floods worldwide

    NASA Astrophysics Data System (ADS)

    Ceola, Serena; Laio, Francesco; Montanari, Alberto

    2015-04-01

    River floods are the first cause of human fatalities and economic losses among natural disasters. Floods claim thousands of lives every year, but effective and high-resolution methods to provide a spatially and temporally detailed analysis of the human exposure to floods at the global scale are still lacking. To this aim, we use satellite nightlight data to prove that nocturnal lights close to rivers are consistently related to flood damages. First, we analyse 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. Then, 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. Our results show an enhancement of exposure to floods worldwide, particularly in Africa and Asia. Therefore our analysis argues for the development of valuable flood preparedness and mitigation strategies, also associated to the projected effects of climate change on flood-related losses.

  4. Improvement of Risk Assessment from Space Radiation Exposure for Future Space Exploration Missions

    Microsoft Academic Search

    M. Y. Kim; A. L. Ponomarev; H. Nounu; H. Hussein; F. A. Cucinotta; William Atwell

    2007-01-01

    Protecting astronauts from space radiation exposure is an important challenge for mission design and operations for future exploration-class and long-duration missions. Crew members are exposed to sporadic solar particle events (SPEs) as well as to the continuous galactic cosmic radiation (GCR). If sufficient protection is not provided the radiation risk to crew members from SPEs could be significant. To improve

  5. A comparison of quality factors and weighting factors for characterizing astronaut radiation exposures

    Microsoft Academic Search

    Neal Zapp; Frank Cucinotta; W. Atwell

    2002-01-01

    Radiation exposures are typically characterized by two quantities. The first is the absorbed dose, or the energy deposited per unit mass for specific types of radiation passing through specified materials. The same amount of energy deposited in material by two different types of radiation, however, can result in two different levels of risk. Because of this, for the purpose of

  6. Conceptual basis for evaluating risk from low-level radiation exposure

    SciTech Connect

    Bond, V.P.

    1981-01-01

    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.

  7. Past Exposure to Densely Ionizing Radiation Leaves a Unique Permanent Signature in the Genome

    PubMed Central

    Hande, M. Prakash; Azizova, Tamara V.; Geard, Charles R.; Burak, Ludmilla E.; Mitchell, Catherine R.; Khokhryakov, Valentin F.; Vasilenko, Evgeny K.; Brenner, David J.

    2003-01-01

    Speculation has long surrounded the question of whether past exposure to ionizing radiation leaves a unique permanent signature in the genome. Intrachromosomal rearrangements or deletions are produced much more efficiently by densely ionizing radiation than by chemical mutagens, x-rays, or endogenous aging processes. Until recently, such stable intrachromosomal aberrations have been very hard to detect, but a new chromosome band painting technique has made their detection practical. We report the detection and quantification of stable intrachromosomal aberrations in lymphocytes of healthy former nuclear-weapons workers who were exposed to plutonium many years ago. Even many years after occupational exposure, more than half the blood cells of the healthy plutonium workers contain large (>6 Mb) intrachromosomal rearrangements. The yield of these aberrations was highly correlated with plutonium dose to the bone marrow. The control groups contained very few such intrachromosomal aberrations. Quantification of this large-scale chromosomal damage in human populations exposed many years earlier will lead to new insights into the mechanisms and risks of cytogenetic damage. PMID:12679897

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

    SciTech Connect

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

    1999-11-01

    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.

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

    PubMed Central

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

    2000-01-01

    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

  10. Occupational Radiation Exposure from C Arm Fluoroscopy During Common Orthopaedic Surgical Procedures and its Prevention

    PubMed Central

    Samuel, Sumant; Saran, Atul K; Mahajan, M K; Mam, M K

    2015-01-01

    Background: Image intensifiers have become popular due to the concept of minimally invasive surgeries leading to decreasing invasiveness, decreased operative time, and less morbidity. The drawback, however, is an increased risk of radiation exposure to surgeon, patient and theatre staff. These exposures have been of concern due to their potential ability to produce biological effects. The present study was embarked upon to analyse the amount of radiation received by orthopedic surgeons in India using standard precautionary measures and also to bring awareness about the use of image intensifier safety in everyday practice. Materials and Methods: Twelve right-handed male orthopedic surgeons (4 senior consultants, 5 junior consultants and 3 residents) were included in a three month prospective study for radiation exposure measurement with adequate protection measures in all procedures requiring C Arm fluoroscopy. Each surgeon was provided with 5 Thermo Luminescent Dosimeter (TLD) badges which were tagged at the level of neck, chest, gonads and both wrists. Operative time and exposure time of each procedure was recorded. Exposure dose of each badge at the end of the study was obtained and the results were analysed. Results: Mean radiation exposure to all the parts were well within permissible limits. There was a significantly positive correlation between the exposure time and the exposure dose for the left wrist (r=0.735, p<0.01) and right wrist (r=0.58, p<0.05). The dominant hand had the maximum exposure overall. Conclusion: Orthopaedic surgeons are not classified radiation workers. The mean exposure doses to all parts of the body were well within permissible limits. Nothing conclusive, however, can be said about the stochastic effects (chance effects like cancers). Any amount of radiation taken is bound to pose an additional occupational hazard. It is thus desirable that radiation safety precautions should be taken and exposures regularly monitored with at least one dosimeter for monitoring the whole-body dose. PMID:25954671

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

    PubMed

    Kryshev, A I; Sazykina, T G

    2015-03-01

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

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

    PubMed

    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

    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

  13. Approaches to characterizing human health risks of exposure to fibers.

    PubMed

    Vu, V T; Lai, D Y

    1997-09-01

    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

  14. Activation of Transcription Factor AP2 Mediates UVA Radiation and Singlet Oxygen-Induced Expression of the Human Intercellular Adhesion Molecule 1 Gene

    Microsoft Academic Search

    Susanne Grether-Beck; Sylvia Olaizola-Horn; Heidi Schmitt; Markus Grewe; Andreas Jahnke; Judith P. Johnson; Karlis Briviba; Helmut Sies; Jean Krutmann

    1996-01-01

    UVA radiation is the major component of the UV solar spectrum that reaches the earth, and the therapeutic application of UVA radiation is increasing in medicine. Analysis of the cellular effects of UVA radiation has revealed that exposure of human cells to UVA radiation at physiological doses leads to increased gene expression and that this UVA response is primarily mediated

  15. ICRP publication 112. A report of preventing accidental exposures from new external beam radiation therapy technologies.

    PubMed

    Ortiz López, P; Cosset, J M; Dunscombe, P; Holmberg, O; Rosenwald, J C; Pinillos Ashton, L; Vilaragut Llanes, J J; Vatnitsky, S

    2009-08-01

    Disseminating the knowledge and lessons learned from accidental exposures is crucial in preventing re-occurrence. This is particularly important in radiation therapy; the only application of radiation in which very high radiation doses are deliberately given to patients to achieve cure or palliation of disease. Lessons from accidental exposures are, therefore, an invaluable resource for revealing vulnerable aspects of the practice of radiotherapy, and for providing guidance for the prevention of future occurrences. These lessons have successfully been applied to avoid catastrophic events with conventional technologies and techniques. Recommendations, for example, include the independent verification of beam calibration and independent calculation of the treatment times and monitor units for external beam radiotherapy, and the monitoring of patients and their clothes immediately after brachytherapy. New technologies are meant to bring substantial improvement to radiation therapy. However, this is often achieved with a considerable increase in complexity, which in turn brings opportunities for new types of human error and problems with equipment. Dissemination of information on these errors or mistakes as soon as it becomes available is crucial in radiation therapy with new technologies. In addition, information on circumstances that almost resulted in serious consequences (near-misses) is also important, as the same type of events may occur elsewhere. Sharing information about near-misses is thus a complementary important aspect of prevention. Lessons from retrospective information are provided in Sections 2 and 4 of this report. Disseminating lessons learned for serious incidents is necessary but not sufficient when dealing with new technologies. It is of utmost importance to be proactive and continually strive to answer questions such as 'What else can go wrong', 'How likely is it?' and 'What kind of cost-effective choices do I have for prevention?'. These questions are addressed in Sections 3 and 5 of this report. Section 6 contains the conclusions and recommendations. This report is expected to be a valuable resource for radiation oncologists, hospital administrators, medical physicists, technologists, dosimetrists, maintenance engineers, radiation safety specialists, and regulators. While the report applies specifically to new external beam therapies, the general principles for prevention are applicable to the broad range of radiotherapy practices where mistakes could result in serious consequences for the patient and practitioner. PMID:20478472

  16. 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. ...

  17. Ultraviolet radiation in urban ecosystems with consideration of effects on human health

    Microsoft Academic Search

    Gordon M. Heisler; Richard H. Grant

    2000-01-01

    Excess exposure to ultraviolet radiation (UV) from the sun, particularly the ultraviolet B (UVB), is cited as a cause or contributing factor for deleterious effects on human health, including skin cancers and cataracts. Rates of skin cancer have increased greatly in recent years, and increased UVB caused by reductions in stratospheric ozone may be responsible for some of the increase

  18. A Quality Assurance Initiative Targeting Radiation Exposure to Neuroscience Patients in the Intensive Care Unit

    PubMed Central

    Josephson, S. Andrew; Rosow, Laura; Smith, Wade S.

    2015-01-01

    Background: Patients admitted to an intensive care unit (ICU) with a primary neurologic disorder often receive multiple radiation-based diagnostic studies of the head and neck. Although radiation exposure puts them at risk of intracranial and neck tumors, the amount of radiation received is largely unknown. Methods: We sought to accurately collect cumulative radiation exposure data from radiation-based studies in a retrospective cohort of patients admitted to the neuroscience ICU (NICU) at a single institution. Radiation doses of studies were converted to estimated effective doses in mSv via literature-published formulas. To impact ordering practices, we piloted an educational initiative on patient radiation exposure to a cohort of physicians caring for patients with a diagnosis of acute subarachnoid hemorrhage. Patients were randomized to have radiation exposure data posted at the bedside for physician viewing. Results: We identified 641 patients from July 2010 to March 2011 who had received at least 1 computed tomography-based study of the head. Patients received on average 18.4 mSv of radiation from head and neck imaging. Patients with subarachnoid hemorrhage received the highest average levels of radiation exposure (37.1 mSv). Attributable risk of carcinogenesis was estimated to be low. A pilot educational initiative did not reduce the total estimated effective dose per patient. Conclusions: Accurate reporting of estimated effective doses for NICU patients is feasible and can be provided to ordering physicians to assist with clinical decision making and potentially lower exposure risk. Further strategies are needed to reduce unnecessary radiation exposure at the physician ordering level. PMID:25553223

  19. Environmental Residues and Biomonitoring Estimates of Human Insecticide Exposure from Treated Residential Turf

    Microsoft Academic Search

    C. E. Bernard; H. Nuygen; D. Truong; R. I. Krieger

    2001-01-01

    Intentional and unavoidable human exposure is a consequence of using pesticides to nurture and protect residential turf. Limited\\u000a exposure studies have been conducted for assessing potential human exposure of turf residues. Exposure was measured in persons\\u000a who performed a 20-minute structured activity (Jazzercise®) on chlorpyrifos (CP)-treated Kentucky bluegrass (12 ± 4 ?g CP\\/cm2). CP exposure was measured by determining urine

  20. The Effects of Gamma and Proton Radiation Exposure on Hematopoietic Cell Counts in the Ferret Model.

    PubMed

    Sanzari, Jenine K; Wan, X Steven; Krigsfeld, Gabriel S; Wroe, Andrew J; Gridley, Daila S; Kennedy, Ann R

    2013-10-01

    Exposure to total-body radiation induces hematological changes, which can detriment one's immune response to wounds and infection. Here, the decreases in blood cell counts after acute radiation doses of ?-ray or proton radiation exposure, at the doses and dose-rates expected during a solar particle event (SPE), are reported in the ferret model system. Following the exposure to ?-ray or proton radiation, the ferret peripheral total white blood cell (WBC) and lymphocyte counts decreased whereas neutrophil count increased within 3 hours. At 48 hours after irradiation, the WBC, neutrophil, and lymphocyte counts decreased in a dose-dependent manner but were not significantly affected by the radiation type (?-rays verses protons) or dose rate (0.5 Gy/minute verses 0.5 Gy/hour). The loss of these blood cells could accompany and contribute to the physiological symptoms of the acute radiation syndrome (ARS). PMID:25356435

  1. Ionising radiation exposure in patients with circular frame treatment of distal tibial fractures.

    PubMed

    Bryant, H; Dearden, P M C; Harwood, P J; Wood, T J; Sharma, H K

    2015-08-01

    Total radiation exposure accumulated during circular frame treatment of distal tibial fractures was quantified in 47 patients treated by a single surgeon from February 2007 until Oct 2010. The radiation exposures for all relevant radiology procedures for the distal tibial injury were included to estimate the radiation risk to the patient. The median time of treatment in the frame was 169 days (range 105-368 days). Patients underwent a median of 13 sets of plain radiographs; at least one intra operative exposure and 16 patients underwent CT scanning. The median total effective dose per patient from time of injury to discharge was 0.025mSv (interquartile range 0.013-0.162 and minimum to maximum 0.01-0.53). The only variable shown to be an independent predictor of cumulative radiation dose on multivariate analysis was the use of CT scanning. This was associated with a 13-fold increase in overall exposure. Radiation exposure during treatment of distal tibial fractures with a circular frame in this group was well within accepted safe limits. The fact that use of CT was the only significant predictor of overall exposure serves as a reminder to individually assess the risk and utility of radiological investigations on an individual basis. This is consistent with the UK legal requirements for justification of all X-ray imaging, as set out in the Ionising Radiation (Medical Exposure) Regulations 2000 [1]. PMID:25986665

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

    PubMed Central

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

    2013-01-01

    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.

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

    NASA Astrophysics Data System (ADS)

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

    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

  4. Quantitative Phosphoproteomics Identifies Filaggrin and other Targets of Ionizing Radiation in a Human Skin Model

    SciTech Connect

    Yang, Feng; Waters, Katrina M.; Webb-Robertson, Bobbie-Jo M.; Sowa, Marianne B.; Freiin von Neubeck, Claere H.; Aldrich, Joshua T.; Markillie, Lye Meng; Wirgau, Rachel M.; Gristenko, Marina A.; Zhao, Rui; Camp, David G.; Smith, Richard D.; Stenoien, David L.

    2012-04-17

    Our objective here was to perform a quantitative phosphoproteomic study on a reconstituted human skin tissue to identify low and high dose ionizing radiation dependent signaling in a complex 3-dimensional setting. Application of an isobaric labeling strategy using sham and 3 radiation doses (3, 10, 200 cGy) resulted in the identification of 1113 unique phosphopeptides. Statistical analyses identified 151 phosphopeptides showing significant changes in response to radiation and radiation dose. Proteins responsible for maintaining skin structural integrity including keratins and desmosomal proteins (desmoglein, desmoplakin, plakophilin 1 and 2,) had altered phosphorylation levels following exposure to both low and high doses of radiation. A phosphorylation site present in multiple copies in the linker regions of human profilaggrin underwent the largest fold change. Increased phosphorylation of these sites coincided with altered profilaggrin processing suggesting a role for linker phosphorylation in human profilaggrin regulation. These studies demonstrate that the reconstituted human skin system undergoes a coordinated response to ionizing radiation involving multiple layers of the stratified epithelium that serve to maintain skin barrier functions and minimize the damaging consequences of radiation exposure.

  5. Occupational Exposure to Diagnostic Radiology in Workers without Training in Radiation Safety

    NASA Astrophysics Data System (ADS)

    Gaona, Enrique; Enríquez, Jesús G. Franco

    2004-09-01

    The physicians, technicians, nurses, and others involved in radiation areas constitute the largest group of workers occupationally exposed to man-made sources of radiation. Personnel radiation exposure must be monitored for safety and regulatory considerations, this assessment may need to be made over a period of one month or several months. The purpose of this study was to carry out an exploratory survey of occupational exposures associated with diagnostic radiology. The personnel dosimeters used in this study were thermoluminiscent dosimeters (TLDs). The reported number of monitored workers was 110 of different departments of radiology of the Mexican Republic without education in radiation safety, included general fluoscopic/radiographic imaging, computed tomography and mammography procedures. Physicians and X-ray technologist in diagnostic radiology receive an average annual effective dose of 2.9 mSv with range from 0.18 to 5.64 mSv. The average level of occupational exposures is generally similar to the global average level of natural radiation exposure. The annual global per capita effective dose due to natural radiation sources is 2.4 mSv (UNSCEAR 2000 Report). There is not significant difference between average occupational exposures and natural radiation exposure for p < 0.05.

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

    PubMed

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

    2014-01-30

    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

  7. Fragmentation of extracellular DNA by long-term exposure to radiation from uranium in aquatic environments.

    PubMed

    Arruda-Neto, J D T; Nieto, L; Righi, H; Cotta, M A; Carrer, H; Rodrigues, T E; Genofre, G C

    2012-08-01

    Persistent harmful scenarios associated with disposal of radioactive waste, high-background radiation areas and severe nuclear accidents are of great concern regarding consequences to both human health and the environment. Of particular concern is the extracellular DNA in aquatic environments contaminated by radiological substances. Strand breaks induced by radiation promote decrease in the transformation efficiency for extracellular DNA. The focus of this study is the quantification of DNA damage following long-term exposure (over one year) to low doses of natural uranium (an alpha particle emitter) to simulate natural conditions, since nothing is known about alpha radiation induced damage to extracellular DNA. A high-resolution Atomic Force Microscope was used to evaluate DNA fragments. Double-stranded plasmid pBS as a model for extracellular DNA was exposed to different amounts of natural uranium. It was demonstrated that low concentrations of U in water (50 to 150 ppm) produce appreciable numbers of double strand breaks, scaling with the square of the average doses. The importance of these findings for environment monitoring of radiological pollution is addressed. PMID:22760469

  8. Radiation exposure reduction by use of Kevlar cassettes in the neonatal nursery

    SciTech Connect

    Herman, M.W.; Mak, H.K.; Lachman, R.S.

    1987-05-01

    A study was performed to determine whether the use of Kevlar cassettes in the neonatal intensive care nursery would reduce radiation exposure to patients. The radiation dose to the neonates was measured by using thermoluminescent dosimeters. In addition, the attenuation of the Kevlar cassettes and the sensitivity of the film-screen combination were compared with the previously used system. The greatest radiation reduction using a mobile X-ray unit was 27%; based on sensitivity measurements, the theoretical reduction averaged 38%. The reduction in radiation exposure resulted from reduced attenuation by the Kevlar cassette.

  9. Radiation exposure reduction by use of Kevlar cassettes in the neonatal nursery.

    PubMed

    Herman, M W; Mak, H K; Lachman, R S

    1987-05-01

    A study was performed to determine whether the use of Kevlar cassettes in the neonatal intensive care nursery would reduce radiation exposure to patients. The radiation dose to the neonates was measured by using thermoluminescent dosimeters. In addition, the attenuation of the Kevlar cassettes and the sensitivity of the film-screen combination were compared with the previously used system. The greatest radiation reduction using a mobile X-ray unit was 27%; based on sensitivity measurements, the theoretical reduction averaged 38%. The reduction in radiation exposure resulted from reduced attenuation by the Kevlar cassette. PMID:3495126

  10. Arsenic exposure induces the Warburg effect in cultured human cells

    SciTech Connect

    Zhao, Fei; Severson, Paul; Pacheco, Samantha; Futscher, Bernard W.; Klimecki, Walter T., E-mail: klimecki@pharmacy.arizona.edu

    2013-08-15

    Understanding how arsenic exacts its diverse, global disease burden is hampered by a limited understanding of the particular biological pathways that are disrupted by arsenic and underlie pathogenesis. A reductionist view would predict that a small number of basic pathways are generally perturbed by arsenic, and manifest as diverse diseases. Following an initial observation that arsenite-exposed cells in culture acidify their media more rapidly than control cells, the report here shows that low level exposure to arsenite (75 ppb) is sufficient to induce aerobic glycolysis (the Warburg effect) as a generalized phenomenon in cultured human primary cells and cell lines. Expanded studies in one such cell line, the non-malignant pulmonary epithelial line, BEAS-2B, established that the arsenite-induced Warburg effect was associated with increased accumulation of intracellular and extracellular lactate, an increased rate of extracellular acidification, and inhibition by the non-metabolized glucose analog, 2-deoxy-D-glucose. Associated with the induction of aerobic glycolysis was a pathway-wide induction of glycolysis gene expression, as well as protein accumulation of an established glycolysis master-regulator, hypoxia-inducible factor 1A. Arsenite-induced alteration of energy production in human cells represents the type of fundamental perturbation that could extend to many tissue targets and diseases. - Highlights: • Chronic arsenite exposure induces aerobic glycolysis, dubbed the “Warburg effect”. • Arsenite-induced Warburg effect is a general phenomenon in cultured human cells. • HIF-1A may mediate arsenite induced Warburg effect.

  11. IONIZING RADIATION EXPOSURE OF THE POPULATION OF THE U.S.

    EPA Science Inventory

    This report updates information published by the National Council on Radiation Protection and Measurements (NCRP) in 1987. NCRP reports are considered the authoritative reference for the sources and magnitude of average background exposure to the U.S. population....

  12. Factors modifying the response of large animals to low-intensity radiation exposure

    NASA Technical Reports Server (NTRS)

    Page, N. P.; Still, E. T.

    1972-01-01

    In assessing the biological response to space radiation, two of the most important modifying factors are dose protraction and dose distribution to the body. Studies are reported in which sheep and swine were used to compare the hematology and lethality response resulting from radiation exposure encountered in a variety of forms, including acute (high dose-rate), chronic (low dose-rate), combinations of acute and chronic, and whether received as a continuous or as fractionated exposure. While sheep and swine are basically similar in response to acute radiation, their sensitivity to chronic irradiation is markedly different. Sheep remain relatively sensitive as the radiation exposure is protracted while swine are more resistant and capable of surviving extremely large doses of chronic irradiation. This response to chronic irradiation correlated well with changes in radiosensitivity and recovery following an acute, sublethal exposure.

  13. Case definitions for human poisonings postulated to palytoxins exposure.

    PubMed

    Tubaro, A; Durando, P; Del Favero, G; Ansaldi, F; Icardi, G; Deeds, J R; Sosa, S

    2011-03-01

    A series of case reports and anecdotal references describe the adverse effects on human health ascribed to the marine toxin palytoxin (PLTX) after different exposure routes. They include poisonings after oral intake of contaminated seafood, but also inhalation and cutaneous/systemic exposures after direct contact with aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing cnidarian zoanthids. The symptoms commonly recorded during PLTX intoxication are general malaise and weakness, associated with myalgia, respiratory effects, impairment of the neuromuscular apparatus and abnormalities in cardiac function. Systemic symptoms are often recorded together with local damages whose intensity varies according to the route and length of exposure. Gastrointestinal malaise or respiratory distress is common for oral and inhalational exposure, respectively. In addition, irritant properties of PLTX probably account for the inflammatory reactions typical of cutaneous and inhalational contact. Unfortunately, the toxin identification and/or quantification are often incomplete or missing and cases of poisoning are indirectly ascribed to PLTXs, according only to symptoms, anamnesis and environmental/epidemiological investigations (i.e. zoanthid handling or ingestion of particular seafood). Based on the available literature, we suggest a "case definition of PLTX poisonings" according to the main exposure routes, and, we propose the main symptoms to be checked, as well as, hemato-clinical analysis to be carried out. We also suggest the performance of specific analyses both on biological specimens of patients, as well as, on the contaminated materials responsible for the poisoning. A standardized protocol for data collection could provide a more rapid and reliable diagnosis of palytoxin-poisoning, but also the collection of necessary data for the risk assessment for this family of toxins. PMID:21255599

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

    PubMed Central

    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

    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

  15. Dose-Rate Dependence of High-Dose Health Effects in Humans from Photon Radiation with Application to Radiological Terrorism

    Microsoft Academic Search

    D. J. Strom; Daniel J

    2005-01-01

    In 1981, as part of a symposium entitled ''The Control of Exposure of the Public to Ionizing Radiation in the Event of Accident or Attack,'' Lushbaugh, H?bner, and Fry published a paper examining ''radiation tolerance'' of various human health endpoints as a function of dose rate. This paper may not have received the notice it warrants. The health endpoints examined

  16. Estimating exposure and dose to characterize health risks: the role of human tissue monitoring in exposure assessment.

    PubMed Central

    Sexton, K; Callahan, M A; Bryan, E F

    1995-01-01

    Exposure assessment is an integral part of health risk characterization. Exposure assessments typically address three critical aspects of exposure: the number of people exposed to the environmental toxicant, at specific concentrations, for the time period of interest; the resulting dose; and the relative contribution of important sources and pathways to exposure/dose. Because historically both "point-of-contact" measurements and information about dose and related pharmacokinetic processes have been lacking, exposure assessments have had to rely on construction of "scenarios" to estimate exposure and dose. This could change, however, as advances in development of biologic markers of exposure and dose make it possible to measure and interpret toxicant concentrations in accessible human tissues. The increasing availability of "biomarkers," coupled with improvements in pharmacokinetic understanding, present opportunities to estimate ("reconstruct") exposure from measurements of dose and knowledge of intake and uptake parameters. Human tissue monitoring, however, is not a substitute for more traditional methods of measuring exposure, but rather a complementary approach. A combination of exposure measurements and dose measurements provides the most credible scientific basis for exposure assessment. PMID:7635107

  17. Dosimetry for ultraviolet radiation exposure of the eye

    Microsoft Academic Search

    David H. Sliney

    1994-01-01

    The eye is exposed daily to UVR from skylight and ground reflections when outdoors in sunlight. Additional exposure occurs daily from artificial sources such as fluorescent lamps. Some workers, notably welders, are exposed to industrial sources of UVR. The geometry of exposure critically influences the actual UVR dose to the cornea and lens. When exposed to bright light, squinting reduces

  18. Alterations of nitric oxide synthase and xanthine oxidase activities of human keratinocytes by ultraviolet B radiation

    Microsoft Academic Search

    George Deliconstantinos; Vassiliki Villiotou; John C. Stavrides

    1996-01-01

    In the present study, we demonstrated that NO synthase (cNOS) and xanthine oxidase (XO) of human keratinocytes can be activated to release NO, Superoxide (O2?) and peroxynitrite (ONOO?) following exposure to ultraviolet B (UVB) radiation. We defined that this photo induced response may be involved in the pathogenesis of sunburn erythema and inflammation. Treatment of human keratinocytes with UVB (290–320

  19. Unfinished business: Radiation Exposure Compensation Act (RECA) for post-1971 U.S. uranium underground miners.

    PubMed

    Madsen, Gary E; Dawson, Susan E

    2004-01-01

    Congress enacted the Radiation Exposure Compensation Act (RECA) in 1990 and amended it in 2000. Included for compensation were underground uranium miners who developed health problems related to radiation exposures. Neither the 1990 Act nor the 2000 Amendments covered post-1971 workers. In this article, we will examine regulatory history and scientific evidence used for the passage of RECA for the pre-1972 miners and will present evidence supporting the inclusion of the post-1971 workers. PMID:15855079

  20. Radiation exposure and protection in cardiac catheterization laboratories

    Microsoft Academic Search

    Stephen W. Miller; Frank P. Castronovo Jr.

    1985-01-01

    Cardiac catheterization with angiography can deliver the greatest dose of x-radiation of any diagnostic medical examination. The physicians and technologists in the angiography room receive low-level scattered radiation over a period of months to decades. Although the radiobiology is complex, the physicians who perform cardiac catheterization should be familiar with the potential genetic and somatic effects of radiation and with

  1. Inactivation of NADPH oxidases NOX4 and NOX5 protects human primary fibroblasts from ionizing radiation-induced DNA damage.

    PubMed

    Weyemi, Urbain; Redon, Christophe E; Aziz, Towqir; Choudhuri, Rohini; Maeda, Daisuke; Parekh, Palak R; Bonner, Michael Y; Arbiser, Jack L; Bonner, William M

    2015-03-01

    Human exposure to ionizing radiation from medical procedures has increased sharply in the last three decades. Recent epidemiological studies suggest a direct relationship between exposure to ionizing radiation and health problems, including cancer incidence. Therefore, minimizing the impact of radiation exposure in patients has become a priority in the development of future clinical practices. Crucial players in radiation-induced DNA damage include reactive oxygen species (ROS), but the sources of these have remained elusive. To the best of our knowledge, we show here for the first time that two members of the ROS-generating NADPH oxidase family (NOXs), NOX4 and NOX5, are involved in radiation-induced DNA damage. Depleting these two NOXs in human primary fibroblasts resulted in reduced levels of DNA damage as measured by levels of radiation-induced foci, a marker of DNA double-strand breaks (DSBs) and the comet assay coupled with increased cell survival. NOX involvement was substantiated with fulvene-5, a NOXs-specific inhibitor. Moreover, fulvene-5 mitigated radiation-induced DNA damage in human peripheral blood mononuclear cells ex vivo. Our results provide evidence that the inactivation of NOXs protects cells from radiation-induced DNA damage and cell death. These findings suggest that NOXs inhibition may be considered as a future pharmacological target to help minimize the negative effects of radiation exposure for millions of patients each year. PMID:25706776

  2. Overview of the Department of Energy's Off-Site Radiation Exposure Review Project (ORERP).

    PubMed

    Church, B W; Wheeler, D L; Campbell, C M; Nutley, R V; Anspaugh, L R

    1990-11-01

    The Off-Site Radiation Exposure Review Project (ORERP) was established by the U.S. Department of Energy to (1) collect, preserve, and disseminate historical data related to radioactive fallout and health effects from nuclear testing, and (2) reconstrut, insofar as possible, the exposures to the off-site public from nuclear testing at the Nevada Test Site and doses to individuals resulting from these exposures. The goals, methods, and example results of the ORERP are presented. PMID:2211109

  3. Digital measurement of heliotropic leaf response in soybean cultivars and leaf exposure to solar UVB radiation

    Microsoft Academic Search

    Cheryl I Bawhey; Richard H Grant; Wei Gao

    2003-01-01

    Inconsistencies in reported sensitivities of soybean cultivars [Glycine max (L.) Merr.] to enhanced ultraviolet-B (UVB) irradiance may in part be due to differences in the radiative environment of the experimental conditions or differences in exposure due to heliotropic response. In order to examine the impact of heliotropic movement on UVB exposure of the soybean upper trifoliate, leaf position was electronically

  4. THE HUMAN EXPOSURE DATABASE SYSTEM (HEDS)-PUTTING THE NHEXAS DATA ON-LINE

    EPA Science Inventory

    The EPA's National Exposure Research Laboratory (NERL) has developed an Internet accessible Human Exposure Database System (HEDS) to provide the results of NERL human exposure studies to both the EPA and the external scientific communities. The first data sets that will be ava...

  5. Modeling thermal responses in human subjects following extended exposure to radiofrequency energy

    Microsoft Academic Search

    Kenneth R Foster; Eleanor R Adair

    2004-01-01

    BACKGROUND: This study examines the use of a simple thermoregulatory model for the human body exposed to extended (45 minute) exposures to radiofrequency\\/microwave (RF\\/MW) energy at different frequencies (100, 450, 2450 MHz) and under different environmental conditions. The exposure levels were comparable to or above present limits for human exposure to RF energy. METHODS: We adapted a compartmental model for

  6. HEDS - EPA DATABASE SYSTEM FOR PUBLIC ACCESS TO HUMAN EXPOSURE DATA

    EPA Science Inventory

    Human Exposure Database System (HEDS) is an Internet-based system developed to provide public access to human-exposure-related data from studies conducted by EPA's National Exposure Research Laboratory (NERL). HEDS was designed to work with the EPA Office of Research and Devel...

  7. Human Bronchial Epithelial Cell Response to Heavy Particle Exposure

    NASA Astrophysics Data System (ADS)

    Story, Michael; Ding, Liang-Hao; Minna, John; Park, Seong-mi; Peyton, Michael; Larsen, Jill

    2012-07-01

    A battery of non-oncogenically immortalized human bronchial epithelial cells (HBECs) are being used to examine the molecular changes that lead to lung carcinogenesis after exposure to heavy particles found in the free space environment. The goal is to ultimately identify biomarkers of radioresponse that can be used for prediction of carcinogenic risk for fatal lung cancer. Our initial studies have focused on the cell line HBEC3 KT and the isogenic variant HBEC3 KTR53, which overexpresses the RASv12 mutant and where p53 has been knocked down by shRNA, and is considered to be a more oncogenically progressed variant. We have previously described the response of HBEC3 KT at the cellular and molecular level, however, the focus here is on the rate of cellular transformation after HZE radiation exposure and the molecular changes in transformed cells. When comparing the two cell lines we find that there is a maximum rate of cellular transformation at 0.25 Gy when cells are exposed to 1 GeV Fe particles, and, for the HBEC3 KTR53 there are multiple pathways upregulated that promote anchorage independent growth including the mTOR pathway, the TGF-1 pathway, RhoA signaling and the ERK/MAPK pathway as early as 2 weeks after radiation. This does not occur in the HBEC3 KT cell line. Transformed HBEC3 KT cells do not show any morphologic or phenotypic changes when grown as cell cultures. HBEC3 KTR53 cells on the other hand show substantial changes in morphology from a cobblestone epithelial appearance to a mesenchymal appearance with a lack of contact inhibition. This epithelial to mesenchymal change in morphology is accompanied by the expression of vimentin and a reduction in the expression of E-cadherin, which are hallmarks of epithelial to mesenchymal transition. Interestingly, for HBEC3 KT transformed cells there are no mutations in the p53 gene, 2 of 15 clones were found to be heterozygous for the RASV12 mutation, and 3 of 15 clones expressed high levels of BigH3, a TGFB-responsive gene associated with loss of cell anchorage. There is also a range of aneuploidy amongst the transformed clones and ongoing chromosomal analysis by array-based comparative genomic hybridization has identified single or two copy loss of the tumor suppressor gene FHIT, in 8 of 15 transformed clones. This is accompanied by a 6-fold reduction, overall, in FHIT gene expression amongst the 15 clones under examination. Interestingly, in spite of these changes at the molecular level, when implanted subcutaneously into immune-compromised mice, the transformed clones from the HBEC3 KT cell line do not form tumors. This suggests that additional hits are required for oncogenesis, at least in a subcutaneous model, and/or, 2-D tissue culture models to not adequately reflect the underlying biology. We have therefore, begun to examine transformation in a 3-D tissue culture model, bronchocysts, where HBEC cells ultimately differentiate and stop cycling. We have shown that cells in 3-D have reduced gene expression of key DNA repair genes, and are less effective at repairing complex damage. We are now irradiating at dose rates as low as 0.2 cGy/min to test the notion of an inverse dose rate effect for carcinogenesis by HZE particles. In our early experiments we have shown that as the dose rate dropped from 20 cGy/min to 0.2 cGy/min, for the same total dose (0.25 and 0.50 Gy) an increasing percentage of bronchocysts become mis-shapen, suggesting that some cells within the cyst have de-differentiated and have reentered the cell cycle. We are now testing whether those cells are, in fact, cycling and wherther they are transformed by disaggregating the cyst and placing the cells into soft agar culture.

  8. Radiation exposure among medical professionals working in the Intensive Care Unit

    PubMed Central

    Siddiqui, Suhail S.; Jha, Ashish; Konar, Nambiraj; Ranganathan, Priya; Deshpande, Deepak D.; Divatia, Jigeeshu V.

    2014-01-01

    Background and Aims: With the expanding use of diagnostic and therapeutic radiological modalities in critically ill patients, doctors working in Intensive Care Units (ICUs) are increasingly exposed to ionizing radiation. This risk of radiation exposure occurs not only during bedside radiologic procedures, but also when ICU physicians accompany patients to radiology suites. The aim of this study was to quantify levels of radiation exposure among medical professionals working in the ICU. Materials and Methods: The study was carried out prospectively over 6 months in the ICU of a tertiary-referral cancer hospital. Two teams consisting of 4 ICU resident doctors each were instructed to wear thermoluminescent dosimeters (TLDs) during their duty shifts. Standard radiation protection precautions were used throughout the study period. TLDs were also placed in selected areas of the ICU to measure the amount of scattered radiation. TLDs were analyzed at the end of every 3 months. Results: The readings recorded on TLDs placed in the ICU were almost immeasurable. The mean value of residents' radiation exposure was 0.059 mSv, though the highest individual reading approached 0.1 mSv. The projected maximum yearly radiation exposure was 0.4 mSv. Conclusions: If standard radiation safety precautions are followed, the cumulative radiation exposure to ICU resident doctors is well within permissible limits and is not a cause of concern. However, with the increasing use of radiological procedures in the management of critically ill patients, there is a need to repeat such audits periodically to monitor radiation exposure. PMID:25249743

  9. National human exposure assessment survey (NHEXAS): exploratory survey of exposure among population subgroups in EPA Region V

    Microsoft Academic Search

    E D PELLIZZARI; R L PERRITT; C A CLAYTON

    1999-01-01

    The National Human Exposure Assessment Survey (NHEXAS) provides a rich database of exposure and environmental measurements for persons living in EPA Region V (Great Lakes). Demographics (e.g., gender, minority status, age, income, and year home built) between U.S. Census data and the overall Region V sample were compared and showed good agreement. This representative sample was used to conduct an

  10. Acrolein environmental levels and potential for human exposure.

    PubMed

    Faroon, O; Roney, N; Taylor, J; Ashizawa, A; Lumpkin, M H; Plewak, D J

    2008-09-01

    This article provides environmental information on acrolein including environmental fate, potential for human exposure, analytical methods, and a listing of regulations and advisories. Acrolein may be released to the environment in emissions and effluents from its manufacturing and use facilities, in emissions from combustion processes (including cigarette smoking and combustion of petrochemical fuels), from direct application to water and waste water as a slimicide and aquatic herbicide, as a photooxidation product of various hydrocarbon pollutants found in air (including propylene and 1,3-butadiene), and from land disposal of some organic waste materials. Acrolein is a reactive compound and is unstable in the environment. The general population may be exposed to acrolein through inhalation of contaminated air and through ingestion of certain foods. Important sources of acrolein exposure are via inhalation of tobacco smoke and environmental tobacco smoke and via the overheating of fats contained in all living matter. There is potential for exposure to acrolein in many occupational settings as the result of its varied uses and its formation during the combustion and pyrolysis of materials such as wood, petrochemical fuels, and plastics. PMID:19039083

  11. Phosphoproteomics profiling of human skin fibroblast cells reveals pathways and proteins affected by low doses of ionizing radiation

    SciTech Connect

    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.

    2010-11-30

    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. Principle Findings: We have identified 6845 unique phosphopeptides (2566 phosphoproteins) from control and irradiated (2 and 50 cGy) primary human skin fibroblasts one hour post-exposure. Dual statistical analyses based on spectral counts and peak intensities identified 287 phosphopeptides (from 231 proteins) and 244 phosphopeptides (from 182 proteins) that varied significantly following exposure to 2 and 50 cGy respectively. 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. Bioinformatics analyses suggest that low and high doses of radiation affect both overlapping and unique biological processes and suggest a role of 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. Conlcusions: 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 provides 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.

  12. A Case Report: Cytogenetic Dosimetry after Accidental Radiation Exposure during (192)Ir Industrial Radiography Testing.

    PubMed

    Beinke, C; Ben-Shlomo, A; Abend, M; Port, M

    2015-07-01

    The accidental gamma radiation exposure of an industrial radiography worker and the cytogenetic examination of the worker's blood lymphocytes are described here. The exposure of the worker was due to a malfunction at the entrance into the depleted uranium-shielding device of a (192)Ir source during operation. Because the source was sealed no additional beta radiation exposure was assumed. The worker's thermoluminescent dosimeter indicated an absorbed dose of 0.078 Sv, which presumably took place in December 2013. No clinical symptoms were reported in the case history after the potential exposure to radiation. Four months after the incident it was decided that biological dosimetry using dicentric chromosome and micronucleus analysis would be performed to follow radiation protection aspects and to clarify the radiation dose uncertainties for the exposed worker. Micronucleus frequency was not increased above the laboratory's control value of micronucleus background frequency of unexposed individuals. However, the observed dicentric frequency (0.003 dicentric/cell) differs significantly from the laboratory's background level of dicentric chromosomes in unexposed individuals (0.0007 dicentric/cell). Dicentric analysis in 2,048 metaphase cells resulted in an estimated dose of no more than 0.181 Gy (95% upper confidence level), not less than 0.014 Gy (95% lower confidence level) and a mean dose of 0.066 Gy (photon-equivalent whole-body exposure) based on interpolation from the laboratory's calibration curve for (60)Co gamma radiation. Since overdispersion of dicentric chromosomes (u = 9.78) indicated a heterogeneous (partial-body) exposure, we applied the Dolphin method and estimated an exposure of 2.1 Sv affecting 21% of the body volume. Because the overdispersion of dicentric chromosomes was caused by only one heavily damaged cell containing two dicentrics, it is possible that this was an incidental finding. In summary, a radiation overexposure of the radiography worker must be assumed and this case considered as a potential partial-body exposure scenario. PMID:26151173

  13. A meta-analysis of leukaemia risk from protracted exposure to low-dose gamma radiation

    PubMed Central

    Schubauer-Berigan, M K

    2010-01-01

    Context More than 400?000 workers annually receive a measurable radiation dose and may be at increased risk of radiation-induced leukaemia. It is unclear whether leukaemia risk is elevated with protracted, low-dose exposure. Objective We conducted a meta-analysis examining the relationship between protracted low-dose ionising radiation exposure and leukaemia. Data sources Reviews by the National Academies and United Nations provided a summary of informative studies published before 2005. PubMed and Embase databases were searched for additional occupational and environmental studies published between 2005 and 2009. Study selection We selected 23 studies that: (1) examined the association between protracted exposures to ionising radiation and leukaemia excluding chronic lymphocytic subtype; (2) were a cohort or nested case–control design without major bias; (3) reported quantitative estimates of exposure; and (4) conducted exposure–response analyses using relative or excess RR per unit exposure. Methods Studies were further screened to reduce information overlap. Random effects models were developed to summarise between-study variance and obtain an aggregate estimate of the excess RR at 100?mGy. Publication bias was assessed by trim and fill and Rosenthal's file drawer methods. Results We found an ERR at 100?mGy of 0.19 (95% CI 0.07 to 0.32) by modelling results from 10 studies and adjusting for publication bias. Between-study variance was not evident (p=0.99). Conclusions Protracted exposure to low-dose gamma radiation is significantly associated with leukaemia. Our estimate agreed well with the leukaemia risk observed among exposed adults in the Life Span Study (LSS) of atomic bomb survivors, providing increased confidence in the current understanding of leukaemia risk from ionising radiation. However, unlike the estimates obtained from the LSS, our model provides a precise, quantitative summary of the direct estimates of excess risk from studies of protracted radiation exposures. PMID:20935290

  14. Medical Countermeasures for Radiation Exposure and Related Injuries: Characterization of Medicines, FDA-Approval Status and Inclusion into the Strategic National Stockpile

    PubMed Central

    Singh, Vijay K.; Romaine, Patricia L.P.; Seed, Thomas M.

    2015-01-01

    Abstract World events over the past decade have highlighted the threat of nuclear terrorism as well as an urgent need to develop radiation countermeasures for acute radiation exposures and subsequent bodily injuries. An increased probability of radiological or nuclear incidents due to detonation of nuclear weapons by terrorists, sabotage of nuclear facilities, dispersal and exposure to radioactive materials, and accidents provides the basis for such enhanced radiation exposure risks for civilian populations. Although the search for suitable radiation countermeasures for radiation-associated injuries was initiated more than half a century ago, no safe and effective radiation countermeasure for the most severe of these injuries, namely acute radiation syndrome (ARS), has been approved by the United States Food and Drug Administration (FDA). The dearth of FDA-approved radiation countermeasures has prompted intensified research for a new generation of radiation countermeasures. In this communication, the authors have listed and reviewed the status of radiation countermeasures that are currently available for use, or those that might be used for exceptional nuclear/radiological contingencies, plus a limited few medicines that show early promise but still remain experimental in nature and unauthorized for human use by the FDA. PMID:25905522

  15. Medical Countermeasures for Radiation Exposure and Related Injuries: Characterization of Medicines, FDA-Approval Status and Inclusion into the Strategic National Stockpile.

    PubMed

    Singh, Vijay K; Romaine, Patricia L P; Seed, Thomas M

    2015-06-01

    World events over the past decade have highlighted the threat of nuclear terrorism as well as an urgent need to develop radiation countermeasures for acute radiation exposures and subsequent bodily injuries. An increased probability of radiological or nuclear incidents due to detonation of nuclear weapons by terrorists, sabotage of nuclear facilities, dispersal and exposure to radioactive materials, and accidents provides the basis for such enhanced radiation exposure risks for civilian populations. Although the search for suitable radiation countermeasures for radiation-associated injuries was initiated more than half a century ago, no safe and effective radiation countermeasure for the most severe of these injuries, namely acute radiation syndrome (ARS), has been approved by the United States Food and Drug Administration (FDA). The dearth of FDA-approved radiation countermeasures has prompted intensified research for a new generation of radiation countermeasures. In this communication, the authors have listed and reviewed the status of radiation countermeasures that are currently available for use, or those that might be used for exceptional nuclear/radiological contingencies, plus a limited few medicines that show early promise but still remain experimental in nature and unauthorized for human use by the FDA. PMID:25905522

  16. Human exposure to arsenic in groundwater from Lahore district, Pakistan.

    PubMed

    Bibi, Mehwish; Hashmi, Muhammad Zaffar; Malik, Riffat Naseem

    2015-01-01

    In the present study we determined As concentrations in healthy volunteers from three different age groups (children, adults and old age) residing in Lahore, Pakistan to gain insight into arsenic exposure to humans via drinking water. The results revealed that the concentrations of As were significantly (p<0.05) different among different sites, while non significant trends were observed among different age classes. As concentrations in blood and nails samples showed a significant (p<0.05) positive correlation. The mean concentrations of As were higher in nails samples (1.43?g/g) followed by blood samples (1.15?g/L); urine samples (0.82?g/l) and hair samples (0.74?g/g) based on all sites. The antioxidants enzyme activities in blood samples showed a significant (p<0.01) decrease with the increase in As concentrations. The result suggests that urgent action is needed to prevent further human exposure to As. PMID:25434761

  17. Human infection patterns and heterogeneous exposure in river blindness

    PubMed Central

    Filipe, João A. N.; Boussinesq, Michel; Renz, Alfons; Collins, Richard C.; Vivas-Martinez, Sarai; Grillet, María-Eugenia; Little, Mark P.; Basáñez, María-Gloria

    2005-01-01

    Here we analyze patterns of human infection with Onchocerca volvulus (the cause of river blindness) in different continents and ecologies. In contrast with some geohelminths and schistosome parasites whose worm burdens typically exhibit a humped pattern with host age, patterns of O. volvulus infection vary markedly with locality. To test the hypothesis that such differences are partly due to heterogeneity in exposure to vector bites, we develop an age- and sex-structured model for intensity of infection, with parasite regulation within humans and vectors. The model is fitted to microfilarial data from savannah villages of northern Cameroon, coffee fincas of central Guatemala, and forest-dwelling communities of southern Venezuela that were recorded before introducing ivermectin treatment. Estimates of transmission and infection loads are compared with entomological and epidemiological field data. Host age- and sex-heterogeneous exposure largely explains locale-specific infection patterns in onchocerciasis (whereas acquired protective immunity has been invoked for other helminth infections). The basic reproductive number,R0, ranges from 5 to 8, which is slightly above estimates for other helminth parasites but well below previously presented values. PMID:16217028

  18. Statistical multipath exposure of a human in a realistic electromagnetic environment.

    PubMed

    Vermeeren, Günter; Joseph, Wout; Olivier, Christof; Martens, Luc

    2008-04-01

    A new and fast numerical method is presented to assess the whole-body averaged specific absorption rate (SAR) in a human body model in a realistic electromagnetic environment. The method requires a minimum set of initial numerical simulations with a 3D electromagnetic solver. From the initial simulation results, the absorption can be quickly (within 1 s) determined in a realistic electromagnetic environment. The realistic electromagnetic environment has been modeled as a finite sum of incident plane waves. The presented fast method serves as a substitute for brute-force 3D electromagnetic simulations. Therefore, the method must only be validated with brute-force 3D electromagnetic simulations in terms of whole-body averaged SAR, and excellent agreement has been observed. The method has been applied to assess the cumulative distribution function of the whole-body averaged SAR in a spheroid human body model for four types of realistic electromagnetic environments. We observed that for all the four environments the whole-body averaged SAR complies with the International Commission on Non Ionizing Radiation Protection basic restriction for general public. Furthermore, the whole-body averaged SAR for a realistic exposure exceeds the worst-case single plane wave exposure in approximately 10% of the exposure samples. PMID:18332726

  19. Dosimetry for ultraviolet radiation exposure of the eye

    NASA Astrophysics Data System (ADS)

    Sliney, David H.

    1994-07-01

    The eye is exposed daily to UVR from skylight and ground reflections when outdoors in sunlight. Additional exposure occurs daily from artificial sources such as fluorescent lamps. Some workers, notably welders, are exposed to industrial sources of UVR. The geometry of exposure critically influences the actual UVR dose to the cornea and lens. When exposed to bright light, squinting reduces UVR exposure. the optical properties of the eye and behavioral responses to bright light both contribute to limiting actual UVR exposure. The actual daily dos of UVR is considerably less than what many previous investigators have assumed. The geometrical, as well as temporal and spectral, aspects of ocular dosimetry will be reviewed in order to allow participants a better insight into the practical impact of many laboratory studies of UVR effects upon ocular tissues.

  20. Human lead metabolism: Chronic exposure, bone lead and physiological models

    NASA Astrophysics Data System (ADS)

    Fleming, David Eric Berkeley

    Exposure to lead is associated with a variety of detrimental health effects. After ingestion or inhalation, lead may be taken up from the bloodstream and retained by bone tissue. X-ray fluorescence was used to make in vivo measurements of bone lead concentration at the tibia and calcaneus for 367 active and 14 retired lead smelter workers. Blood lead levels following a labour disruption were used in conjunction with bone lead readings to examine the endogenous release of lead from bone. Relations between bone lead and a cumulative blood lead index differed depending on time of hiring. This suggests that the transfer of lead from blood to bone has changed over time, possibly as a result of varying exposure conditions. A common polymorphism in the ?-aminolevulinate dehydratase (ALAD) enzyme may influence the distribution of lead in humans. Blood lead levels were higher for smelter workers expressing the more rare ALAD2 allele. Bone lead concentrations, however, were not significantly different. This implies that a smaller proportion of lead in blood is distributed to tissue for individuals expressing the ALAD2 allele. The O'Flaherty physiological model of lead metabolism was modified slightly and tested with input from the personal exposure histories of smelter workers. The model results were consistent with observation in tern of endogenous exposure to lead and accumulation of lead in cortical bone. Modelling the calcaneus as a trabecular bone site did not reproduce observed trends. variations in lead metabolism between different trabecular sites may therefore be significant. The model does not incorporate a genetic component, and its output did not reflect observed differences in this respect. This result provides further support for the influence of the ALAD polymorphism on lead metabolism. Experimental trials with a digital spectrometer revealed superior energy resolution and count throughput relative to the conventional X-ray fluorescence system. The associated reduction in the uncertainty of lead measurement has the potential to benefit future surveys and modelling efforts.

  1. Human exposure to soil contaminants in subarctic Ontario, Canada

    PubMed Central

    Reyes, Ellen Stephanie; Liberda, Eric Nicholas; Tsuji, Leonard James S.

    2015-01-01

    Background Chemical contaminants in the Canadian subarctic present a health risk with exposures primarily occurring via the food consumption. Objective Characterization of soil contaminants is needed in northern Canada due to increased gardening and agricultural food security initiatives and the presence of known point sources of pollution. Design A field study was conducted in the western James Bay Region of Ontario, Canada, to examine the concentrations of polychlorinated biphenyls, dichlorodiphenyltrichloroethane and its metabolites (?DDT), other organochlorines, and metals/metalloids in potentially contaminated agriculture sites. Methods Exposure pathways were assessed by comparing the estimated daily intake to acceptable daily intake values. Ninety soil samples were collected at random (grid sampling) from 3 plots (A, B, and C) in Fort Albany (on the mainland), subarctic Ontario, Canada. The contaminated-soil samples were analysed by gas chromatography with an electron capture detector or inductively coupled plasma mass spectrometer. Results The range of ?DDT in 90 soil samples was below the limit of detection to 4.19 mg/kg. From the 3 soil plots analysed, Plot A had the highest ?DDT mean concentration of 1.12 mg/kg, followed by Plot B and Plot C which had 0.09 and 0.01 mg/kg, respectively. Concentrations of other organic contaminants and metals in the soil samples were below the limit of detection or found in low concentrations in all plots and did not present a human health risk. Conclusion Exposure analyses showed that the human risk was below regulatory thresholds. However, the ?DDT concentration in Plot A exceeded soil guidelines set out by the Canadian Council of Ministers of the Environment of 0.7 mg/kg, and thus the land should not be used for agricultural or recreational purposes. Both Plots B and C were below threshold limits, and this land can be used for agricultural purposes. PMID:26025557

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

    SciTech Connect

    Patchen, M.L.; MacVittie, T.J.; Solberg, B.D.; Souza, L.M. (Armed Forces Radiobiology Research Institute, Bethesda, MD (USA))

    1990-10-01

    C3H/HeN female mice were exposed to whole-body cobalt-60 radiation and administered soluble glucan (5 mg i.v. at 1 h following exposure), recombinant human granulocyte colony-stimulating factor (G-CSF; 2.5 micrograms/day s.c., days 3-12 following exposure), or both agents. Treatments were evaluated for their ability to enhance hemopoietic regeneration, and to increase survival after radiation-induced myelosuppression. Both glucan and G-CSF enhanced hemopoietic regeneration alone; however, greater effects were observed in mice receiving both agents. For example, on day 17 following a sublethal 6.5-Gy radiation exposure, mice treated with saline, G-CSF, glucan, or both agents, respectively, exhibited 36%, 65%, 50%, and 78% of normal bone marrow cellularity, and 84%, 175%, 152%, and 212% of normal splenic cellularity. At this same time, granulocyte-macrophage colony-forming cell (GM-CFC) values in saline, G-CSF, glucan, or combination-treated mice, respectively, were 9%, 46%, 26%, and 57% of normal bone marrow values, and 57%, 937%, 364%, and 1477% of normal splenic values. Endogenous spleen colony formation was also increased in all treatment groups, with combination-treated mice exhibiting the greatest effects. Likewise, although both glucan and G-CSF alone enhanced survival following an 8-Gy radiation exposure, greatest survival was observed in mice treated with both agents. These studies suggest that glucan, a macrophage activator, can synergize with G-CSF to further accelerate hemopoietic regeneration and increase survival following radiation-induced myelosuppression.

  3. REDUCTION IN METABOLIC HEAT PRODUCTION DURING EXPOSURE TO RADIO-FREQUENCY RADIATION IN THE RAT

    EPA Science Inventory

    Male Sprague-Dawley rats were maintained at an ambient temperature (Ta) of 10 C and exposed to 600 MHz radiofrequency (RF) radiation while metabolic rate (MR) was measured by indirect calorimetry. RF radiation exposures were made in a waveguide-type system which permitted the con...

  4. CONSULTATION ON UPDATED METHODOLOGY FOR ESTIMATING CANCER RISKS FROM EXPOSURE TO IONIZING RADIATION

    EPA Science Inventory

    The National Academy of Sciences (NAS) expects to publish the Biological Effects of Ionizing Radiation (BEIR) committee's report (BEIR VII) on risks from ionizing radiation exposures in calendar year 2005. The committee is expected to have analyzed the most recent epidemiology f...

  5. Pacific Northwest Laboratory plan to maintain radiation exposure as low as reasonably achievable (ALARA)

    SciTech Connect

    Higby, D.P.; Denovan, J.T.

    1982-12-01

    This document describes the radiation safety program at the Pacific Northwest Laboratory (PNL). The practices and administrative policies of this program support the principles of ALARA (to maintain radiation exposure as low as reasonably achievable). This document also describes a program to establish safety goals at PNL to help ensure that operations are conducted according to ALARA principles.

  6. Suppression of E. multilocularis Hydatid Cysts after Ionizing Radiation Exposure

    PubMed Central

    Zhou, Rong; Zhang, Hong

    2013-01-01

    Background Heavy-ion therapy has an advantage over conventional radiotherapy due to its superb biological effectiveness and dose conformity in cancer therapy. It could be a potential alternate approach for hydatid cyst treatment. However, there is no information currently available on the cellular and molecular basis for heavy-ion irradiation induced cell death in cystic echinococcosis. Methododology/Principal Findings LD50 was scored by protoscolex death. Cellular and ultrastructural changes within the parasite were studied by light and electron microscopy, mitochondrial DNA (mtDNA) damage and copy number were measured by QPCR, and apoptosis was determined by caspase 3 expression and caspase 3 activity. Ionizing radiation induced sparse cytoplasm, disorganized and clumped organelles, large vacuoles and devoid of villi. The initial mtDNA damage caused by ionizing radiation increased in a dose-dependent manner. The kinetic of DNA repair was slower after carbon-ion radiation than that after X-rays radiation. High dose carbon-ion radiation caused irreversible mtDNA degradation. Cysts apoptosis was pronounced after radiation. Carbon-ion radiation was more effective to suppress hydatid cysts than X-rays. Conclusions These studies provide a framework to the evaluation of attenuation effect of heavy-ion radiation on cystic echinococcosis in vitro. Carbon-ion radiation is more effective to suppress E. multilocularis than X-rays. PMID:24205427

  7. Initiation-promotion model of tumor prevalence in mice from space radiation exposures.

    PubMed

    Cucinotta, F A; Wilson, J W

    1995-08-01

    Exposures in space consist of low-level background components from galactic cosmic rays (GCR), occasional intense-energetic solar-particle events, periodic passes through geomagnetic-trapped radiation, and exposure from possible onboard nuclear-propulsion engines. Risk models for astronaut exposure from such diverse components and modalities must be developed to assure adequate protection in future NASA missions. The low-level background exposures (GCR), including relativistic heavy ions (HZE), will be the ultimate limiting factor for astronaut career exposure. We consider herein a two-mutation, initiation-promotion, radiation-carcinogenesis model in mice in which the initiation stage is represented by a linear kinetics model of cellular repair/misrepair, including the track-structure model for heavy ion action cross-sections. The model is validated by comparison with the harderian gland tumor experiments of Alpen et al. for various ion beams. We apply the initiation-promotion model to exposures from galactic cosmic rays, using models of the cosmic-ray environment and heavy ion transport, and consider the effects of the age of the mice prior to and after the exposure and of the length of time in space on predictions of relative risk. Our results indicate that biophysical models of age-dependent radiation hazard will provide a better understanding of GCR risk than models that rely strictly on estimates of the initial slopes of these radiations. PMID:7480628

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

    NASA Technical Reports Server (NTRS)

    Adamczyk, Anne; Clowdsley, Martha; Qualls, Garry; Blattnig, Steve; Lee, Kerry; Fry, Dan; Stoffle, Nicholas; Simonsen, Lisa; Slaba, Tony; Walker, Steven; Zapp, Edward

    2011-01-01

    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. For short missions, radiation risk is dominated by the possibility of a large Solar Particle Event (SPE). Longer duration missions have both SPE and Galactic Cosmic Ray (GCR) risks. SPE exposure can contribute significantly toward cancer induction in combination with GCR. As mission duration increases, mitigation strategies must address the combined risks from SPE and GCR exposure. In this paper, full mission exposure assessments were performed for the proposed long duration lunar surface mission scenarios. In order to accomplish these assessments, previously developed radiation shielding models for a proposed lunar habitat and rover were utilized. 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 the proposed timelines. Mission exposure results, assessed in terms of effective dose, are presented for the proposed timelines and recommendations are made for improved astronaut shielding and safer operational practices.

  9. System performance of phosphor screen coupled CMOS imager for long-term radiation exposure

    NASA Astrophysics Data System (ADS)

    Kim, Kwang Hyun

    2009-08-01

    We present the performances of a scintillator coupled CMOS APS imager under cumulative X-ray exposure conditions in terms of the modulation transfer function (MTF), noise power spectrum, and detective quantum efficiency (DQE). An industrial X-ray generator with the condition of 50 kVp/500 ?A was used to take cumulative exposure conditions. The experimental results show that the MTF and DQE exponentially degraded because of direct X-ray exposure of the imager through the scintillator. For the given scintillator and radiation exposure, the system performance of the scintillator coupled CMOS APS imager can be predicted.

  10. Increased exposure of Southern Ocean phytoplankton to ultraviolet radiation

    Microsoft Academic Search

    Dan Lubin; Kevin R. Arrigo; Gert L. van Dijken

    2004-01-01

    Satellite remote sensing of both surface solar ultraviolet radiation (UVR) and chlorophyll over two decades shows that biologically significant ultraviolet radiation increases began to occur over the Southern Ocean three years before the ozone “hole” was discovered. Beginning in October 1983, the most frequent occurrences of enhanced UVR over phytoplankton-rich waters occurred in the Weddell Sea and Indian Ocean sectors

  11. Human Exploration of the Moon and Mars: Space Radiation Data, Modeling and Instrumentation Needs

    NASA Technical Reports Server (NTRS)

    Adams, James H.; Barghouty, A. F.; Bhattacharya, M.; Lin, Zi-Wei

    2005-01-01

    On January 14, 2004 President Bush announced the Vision for Space Exploration, a program for long-term human and robotic exploration of the solar system which will include a return of humans to the moon not later than 2020, followed by human missions to Mars. Since this announcement, NASA has been developing plans and mission architectures for these human missions as well as robotic precursor missions. Among the critical needs for research and development in support of this Vision are investigations on the ionizing radiation environment and development of instrumentation to guide NASA in managing the radiation exposure of the crew during the manned missions. For mission planning, models are needed for a reference worst-case solar energetic particle event and a reference worst-case galactic cosmic ray environment. During Lunar missions it will be necessary to carefully manage the radiation exposure of the crew in real time because of the variability of the radiation environment due to solar activity. In particular, prompt warnings will be needed when large solar energetic particle events occur. Accurate predictions will also be needed of the particle flux and flux history at the moon to support critical mission management decisions. A new generation of dosimeters and radiation monitors will also be needed to accompany the crew. These instruments must return data in real time so that they can be used in the critical decisions that must be made if a large solar energetic particle event occurs. This is especially true if it occurs during a lunar excursion. A substantial radiation exposure on extended lunar missions and Mars missions comes from galactic cosmic rays. This exposure must be mitigated by radiation shielding and other measures. During Mars missions the galactic cosmic ray exposure occurs primarily during the cruse phase between the Earth and Mars. This is especially true for opposition class missions. These missions would typically last -430 days with only 30-90 days on Mars. Solar energetic particle events are less of a concern on Mars because of its greater distance from the Sun (approximately 1.5 AU) and the partial protection afforded by its atmosphere (approximately 20 grams per square centimeter). The talk will describe the current plans for future human missions to Earth orbit, the Moon and Mars. The needs for data and models of the radiation environment and radiation detectors to support these missions will be discussed.

  12. M-BAND Study of Radiation-Induced Chromosome Aberrations in Human Epithelial Cells: Radiation Quality and Dose Rate Effects

    NASA Technical Reports Server (NTRS)

    Hada, Megumi; Cucinotta, Francis; Wu, Honglu

    2009-01-01

    The advantage of the multicolor banding in situ hybridization (mBAND) technique is its ability to identify both inter- (translocation to unpainted chromosomes) and intra- (inversions and deletions within a single painted chromosome) chromosome aberrations simultaneously. To study the detailed rearrangement of low- and high-LET radiation induced chromosome aberrations in human epithelial cells (CH184B5F5/M10) in vitro, we performed a series of experiments with Cs-137 gamma rays of both low and high dose rates, neutrons of low dose rate and 600 MeV/u Fe ions of high dose rate, with chromosome 3 painted with multi-binding colors. We also compared the chromosome aberrations in both 2- and 3-dimensional cell cultures. Results of these experiments revealed the highest chromosome aberration frequencies after low dose rate neutron exposures. However, detailed analysis of the radiation induced inversions revealed that all three radiation types induced a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intra-chromosomal aberrations but few inversions were accompanied by inter-chromosomal aberrations. In contrast, neutrons and Fe ions induced a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosomal exchanges. The location of the breaks involved in chromosome exchanges was analyzed along the painted chromosome. The breakpoint distribution was found to be randomly localized on chromosome 3 after neutron or Fe ion exposure, whereas non-random distribution with clustering breakpoints was observed after -ray exposure. Our comparison of chromosome aberration yields between 2- and 3-dimensional cell cultures indicated a significant difference for gamma exposures, but not for Fe ion exposures. These experimental results indicated that the track structure of the radiation and the cellular/chromosome structure can both affect radiation-induced chromosome aberrations.

  13. Results of the controlled exposure of human females to the vapor of methylene chloride

    Microsoft Academic Search

    C. L. Hake; R. D. Stewart; H. V. Forester; A. J. Lebrun; J. E. Peterson

    1974-01-01

    The results of controlled exposure of human females to the vapor of methylene chloride (75092) are presented to supplement a previous comprehensive study of the effects of industrial exposure levels on male human subjects. The data obtained for nine healthy, volunteer human females, aged 20 to 41 years, concerned details of their general health and smoking habits, carboxyhemoglobin (COHb) levels,

  14. Assessment of Galactic Cosmic Ray Models and Implications on the Estimation of Radiation Exposure in Space

    NASA Astrophysics Data System (ADS)

    Mrigakshi, A. I.; Matthiä, D.; Berger, T.; Reitz, G.; Wimmer-Schweingruber, R. F.

    2012-12-01

    Astronauts are subjected to elevated levels of high-energy ionizing radiation in space which poses a substantial risk to their health. Therefore, the assessment of the radiation exposure for long duration manned spaceflight is essential. This is done by measuring dose using various detector techniques and by performing numerical simulations utilizing radiation transport codes which allow to predict radiation exposure for future missions and for conditions where measurements are not feasible or available. A necessary prerequisite for an accurate estimation of the exposure using the latter approach is a reliable description of the radiation spectra. Accordingly, in order to estimate the exposure from the Galactic Cosmic Rays (GCRs), which are one of the major sources of radiation exposure in space, GCR models are required. This work presents an evaluation of GCR models for dosimetry purposes and the effect of applying these models on the estimation of GCR exposure in space outside and inside the Earth's magnetosphere. To achieve this, widely used GCR models - Badhwar-O'Neill2010, Burger-Usoskin, CREME2009 and CREME96, were evaluated by comparing model spectra for light and heavy nuclei with measurements from various high-altitude balloon and space missions over several decades. Additionally a new model, based on the GCR-ISO model, developed at the German Aerospace Centre (DLR) was also investigated. The differences arising in the radiation exposure by applying these models are quantified in terms of absorbed dose and dose equivalent rates that were estimated numerically using the GEANT4 Monte-Carlo framework. During certain epochs in the last decade, there are large discrepancies between the model and the measured spectra. All models exhibit weaknesses in describing the increased GCR flux that was observed in 2009-2010. The differences in the spectra, described by the models, result in considerable differences in the estimated dose quantities.

  15. Spatial learning and memory deficits induced by exposure to iron-56-particle radiation

    NASA Technical Reports Server (NTRS)

    Shukitt-Hale, B.; Casadesus, G.; McEwen, J. J.; Rabin, B. M.; Joseph, J. A.

    2000-01-01

    It has previously been shown that exposing rats to particles of high energy and charge (HZE) disrupts the functioning of the dopaminergic system and behaviors mediated by this system, such as motor performance and an amphetamine-induced conditioned taste aversion; these adverse behavioral and neuronal effects are similar to those seen in aged animals. Because cognition declines with age, spatial learning and memory were assessed in the Morris water maze 1 month after whole-body irradiation with 1.5 Gy of 1 GeV/nucleon high-energy (56)Fe particles, to test the cognitive behavioral consequences of radiation exposure. Irradiated rats demonstrated cognitive impairment compared to the control group as seen in their increased latencies to find the hidden platform, particularly on the reversal day when the platform was moved to the opposite quadrant. Also, the irradiated group used nonspatial strategies during the probe trials (swim with no platform), i.e. less time spent in the platform quadrant, fewer crossings of and less time spent in the previous platform location, and longer latencies to the previous platform location. These findings are similar to those seen in aged rats, suggesting that an increased release of reactive oxygen species may be responsible for the induction of radiation- and age-related cognitive deficits. If these decrements in behavior also occur in humans, they may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere.

  16. Proliferation and cell death of human glioblastoma cells after carbon-ion beam exposure: Morphologic and morphometric analyses

    Microsoft Academic Search

    Takuma Oishi; Atsushi Sasaki; Nobuyuki Hamada; Shogo Ishiuchi; Tomoo Funayama; Tetsuya Sakashita; Yasuhiko Kobayashi; Takashi Nakano; Yoichi Nakazato

    2008-01-01

    Histological analyses of glioblastoma cells after carbon-ion exposure are still limited and ultrastructural characteristics have not been investigated in detail. Here we report the results of morphological and morphometric analyses of a human glioblastoma cell line, CGNH-89, after ionizing radiation to characterize the effect of a carbon-beam on glioblastoma cells. Using CGNH-89 cells exposed to 0-10 Gy of X-ray (140kVp)

  17. Assessment of potential radiation exposures by uncontrolled recycle or reuse of radioactive scrap metals

    SciTech Connect

    Lee, S.Y.; Lee, K.J.

    1999-07-01

    With current waste monitoring technology it is reasonable to assume that much of the material designated as low-level waste, generated within nuclear facilities, is in fact uncontaminated. A criterion for uncontrolled disposal of low-level radioactive contaminated waste is that the radiation exposure of the public and of each individual caused by this disposal is so low that radiation protection measures need not be taken. The International Atomic Energy Agency (IAEA) suggests an annual effective dose of 10 {micro}Sv as a limit for the individual radiation dose and derived the initial control levels of residual radioactivity based on the Publication 30 of the International Commission on Radiological Protection (ICRP). In 1990, new recommendations on radiation protection standards were developed by ICRP to take into account new biological information related to the detriment associated with radiation exposure. Adoption of these recommendations necessitated a revision of the Commission's secondary limits contained in Publication 30. This study summarizes the potential radiation exposure from valuable scrap metal considered for uncontrolled recycle by new ICRP recommendations. Potential exposure pathways to people were analyzed and concentrations leading to an individual dose of 10 {micro}Sv/year were calculated for 14 key radionuclides. These potential radiation doses are compared with the results of previous study.

  18. Measures of patient radiation exposure during endoscopic retrograde cholangiography: Beyond fluoroscopy time

    PubMed Central

    Kachaamy, Toufic; Harrison, Edwyn; Pannala, Rahul; Pavlicek, William; Crowell, Michael D; Faigel, Douglas O

    2015-01-01

    AIM: To determine whether fluoroscope time is a good predictor of patient radiation exposure during endoscopic retrograde cholangiopancreatography. METHODS: This is a prospective observational study of consecutive patients undergoing endoscopic retrograde cholangiopancreatography in a tertiary care setting. Data related to radiation exposure were collected. The following measures were obtained: Fluoroscopy time (FT), dose area product (DAP) and dose at reference point (DOSERP). Coefficients of determination were calculated to analyze the correlation between FT, DAP and DOSRP. Agreement between FT and DAP/DOSRP was assessed using Bland Altman plots. RESULTS: Four hundred sixty-three data sets were obtained. Fluoroscopy time average was 7.3 min. Fluoroscopy related radiation accounted for 86% of the total DAP while acquisition films related radiation accounted for 14% of the DAP. For any given FT there are wide ranges of DAP and DOSERP and the variability in both increases as fluoroscopy time increases. The coefficient of determination (R2) on the non transformed data for DAP and DOSERP versus FT were respectively 0.416 and 0.554. While fluoroscopy use was the largest contributor to patient radiation exposure during endoscopic retrograde cholangiography (ERCP), there is a wide variability in DAP and DOSERP that is not accounted for by FT. DAP and DOSERP increase in variability as FT increases. This translates into poor accuracy of FT in predicting DAP and DOSERP at higher radiation doses. CONCLUSION: DAP and DOSERP in addition to FT should be adopted as new ERCP quality measures to estimate patient radiation exposure. PMID:25684958

  19. Human dermal exposure to galaxolide from personal care products.

    PubMed

    Correia, P; Cruz, A; Santos, L; Alves, A

    2013-06-01

    Musks are synthetic fragrances applied on personal care and household products as fixatives, by retarding the release of other fragrances with higher volatility. Galaxolide is the most used polycyclic musk since the 90th decade, and it has been detected in several environmental and biological matrices, particularly in human tissues and fluids. For exposure assessment purposes, large-monitoring data need to be obtained and rapid but reliable analytical techniques are requested. The main objective of this study is to develop and validate a new and fast analytical methodology to quantify galaxolide in personal care products and to apply this method to real matrices like skin care products (creams and lotions), shower products (soap bar), hair care products (shampoo and hair conditioner) and oral care products (toothpaste), to evaluate the human dermal exposure risk. A dispersive solid-phase extraction is proposed, using QuEChERS methodology, followed by HPLC with fluorescence detection. Some extraction parameters were studied, like the ratio of sample/solvent amounts, the homogenization time, the salt addition effect and the used sorbents. The validation parameters of the developed method were the following: a linearity range of 0.005-1.002 mg kg?¹ sample, a limit of detection of 0.001 mg kg?¹ sample, repeatability between 0.7% and 11.3% (variation coefficient of six standard injections), an intermediate precision of 2.5% (variation coefficient of six independent analysis of the same sample), mean recoveries ranging from 65% (soap bar) to 95% (body cream) and 3% of global uncertainty in most of the working range. The time of analysis, including the extraction steps, is 60 min, allowing a throughput of 4 samples h?¹ . Galaxolide was detected in all of the seven analysed products in concentrations ranging from 0.04 ± 0.01 mg kg?¹ sample (toothpaste) to 280.78 ± 8.19 mg kg?¹ sample (perfumed body cream), which may correspond to a significant estimated daily human dermal exposure of 904 ?g day?¹. PMID:23406205

  20. A review of radiation accidents involving whole body exposure and the relevance to the LD50/60 for man.

    PubMed

    Baverstock, K F; Ash, P J

    1983-11-01

    The absorbed dose of low LET radiation that would be lethal (due to bone marrow failure) to 50% of an exposed human population is a matter for concern in planning for the consequences of an accident to a nuclear reactor and in the event of nuclear war. Since accidents with radiation-generating equipment or in the nuclear fuel processing industry might provide relevant human data, published accounts of these are reviewed. Two accidents, one in the USA, the other in Yugoslavia, both involving exposure to neutrons as well as gamma-rays, are identified as possibly satisfying the criteria of uniformity of dose, magnitude of dose and dose rate necessary to provide useful information on the value of LD50/60 for man. The symptomatology of the exposed individuals is discussed in terms of the published doses. Detailed examination of the dosimetry for these two accidents revealed possible ambiguities and a thorough re-examination has been carried out, the results of which are reported in detail in the Appendix. This indicates considerable and largely unresolvable uncertainty in the magnitude of the dose to exposed individuals when expressed as the low LET equivalent dose in bone marrow. It is also shown that the relationship between severity of effects and dose to exposed individuals is not the same for both accidents and it is argued that the experience from the Yugoslavian accident is more relevant to the determination of the sensitivity to radiation of an exposed human population. Given the uncertain nature of the accident data and the small amount of other relevant human data at present available, the uncertainty of current knowledge of man's sensitivity to the acute effects of exposure to ionising radiation is discussed. PMID:6626874

  1. Radiation Exposure, Socioeconomic Status, and Brain Tumor Risk in the US Air Force: A Nested Case-Control Study

    Microsoft Academic Search

    J. Kevin Grayson

    A nested case-control study was used to investigate the relation between a range of electromagnetic field exposures and brain tumor risk in the US Air Force. Cumulative extremely low frequency and radiofrequency\\/ microwave electromagnetic field potential exposures were estimated from a job-exposure matrix developed for this study. Ionizing radiation exposures were obtained from personal dosimetry records. Men who were exposed

  2. HUMAN EXPOSURE MEASUREMENTS/METHODS: DEVELOP AND TEST IMMUNOCHEMICAL AND OTHER SCREENING TECHNIQUES FOR USE IN EXPOSURE MONITORING

    EPA Science Inventory

    More data are needed to accurately determine the impact of pesticides on human health, especially for infants and young children. One of the ways to reduce uncertainties in the assessment of human exposure to pesticides, and other environmental contaminants, is through extensive...

  3. Radiation Exposure in X-Ray and CT Examinations

    MedlinePLUS

    ... per year from naturally occurring radioactive materials and cosmic radiation from outer space. These natural "background" doses ... living near sea level. The added dose from cosmic rays during a coast-to-coast round trip ...

  4. Exposure to Heavy Ion Radiation Induces Persistent Oxidative Stress in Mouse Intestine

    PubMed Central

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

    2012-01-01

    Ionizing radiation-induced oxidative stress is attributed to generation of reactive oxygen species (ROS) due to radiolysis of water molecules and is short lived. Persistent oxidative stress has also been observed after radiation exposure and is implicated in the late effects of radiation. The goal of this study was to determine if long-term oxidative stress in freshly isolated mouse intestinal epithelial cells (IEC) is dependent on radiation quality at a dose relevant to fractionated radiotherapy. Mice (C57BL/6J; 6 to 8 weeks; female) were irradiated with 2 Gy of ?-rays, a low-linear energy transfer (LET) radiation, and intestinal tissues and IEC were collected 1 year after radiation exposure. Intracellular ROS, mitochondrial function, and antioxidant activity in IEC were studied by flow cytometry and biochemical assays. Oxidative DNA damage, cell death, and mitogenic activity in IEC were assessed by immunohistochemistry. Effects of ? radiation were compared to 56Fe radiation (iso-toxic dose: 1.6 Gy; energy: 1000 MeV/nucleon; LET: 148 keV/µm), we used as representative of high-LET radiation, since it's one of the important sources of high Z and high energy (HZE) radiation in cosmic rays. Radiation quality affected the level of persistent oxidative stress with higher elevation of intracellular ROS and mitochondrial superoxide in high-LET 56Fe radiation compared to unirradiated controls and ? radiation. NADPH oxidase activity, mitochondrial membrane damage, and loss of mitochondrial membrane potential were greater in 56Fe-irradiated mice. Compared to ? radiation oxidative DNA damage was higher, cell death ratio was unchanged, and mitotic activity was increased after 56Fe radiation. Taken together our results indicate that long-term functional dysregulation of mitochondria and increased NADPH oxidase activity are major contributing factors towards heavy ion radiation-induced persistent oxidative stress in IEC with potential for neoplastic transformation. PMID:22936983

  5. Indoor exposure to radiation in the case of an outdoorrelease

    SciTech Connect

    Price, Phillip N.; Jayaraman, Buvana

    2006-06-01

    This report quantifies the effectiveness of ''sheltering in place'' in a commercial building in the event of an outdoor radiological release. The indoor exposure to airborne particles is calculated by solving the mass balance equation that accounts for the loss of particles due to deposition, filtration and exhaust. Quantitative estimates of shelter-inplace effectiveness are provided for typical commercial buildings.

  6. Human Ghrelin Ameliorates Organ Injury and Improves Survival after Radiation Injury Combined with Severe Sepsis

    PubMed Central

    Shah, Kavin G; Wu, Rongqian; Jacob, Asha; Blau, Steven A; Ji, Youxin; Dong, Weifeng; Marini, Corrado P; Ravikumar, Thanjavur S; Coppa, Gene F; Wang, Ping

    2009-01-01

    In the terrorist radiation exposure scenario, radiation victims are likely to suffer from additional injuries such as sepsis. Our previous studies have shown that ghrelin is protective in sepsis. However, it remains unknown whether ghrelin ameliorates sepsis-induced organ injury and mortality after radiation exposure. The purpose of this study is to determine whether human ghrelin attenuates organ injury and improves survival in a rat model of radiation combined injury (RCI) and, if so, the potential mechanism responsible for the benefit. To study this, adult male rats were exposed to 5-Gy whole body irradiation followed by cecal ligation and puncture (CLP, a model of sepsis) 48 h thereafter. Human ghrelin (30 nmol/rat) or vehicle (saline) was infused intravenously via an osmotic minipump immediately after radiation exposure. Blood and tissue samples were collected at 20 h after RCI (68 h after irradiation or 20 h after CLP) for various measurements. To determine the longterm effect of human ghrelin after RCI, the gangrenous cecum was removed at 5 h after CLP and 10-d survival was recorded. In addition, vagotomy or sham vagotomy was performed in sham and RCI animals immediately prior to ghrelin administration, and various measurements were performed at 20 h after RCI. Our results showed that serum levels of ghrelin and its gene expression in the stomach were decreased markedly at 20 h after RCI. Administration of human ghrelin attenuated tissue injury markedly, reduced proinflammatory cytokine levels, decreased tissue myeloperoxidase activity, and improved survival after RCI. Furthermore, elevated plasma levels of norepinephrine (NE) after RCI were reduced significantly by ghrelin. However, vagotomy prevented ghrelin’s beneficial effects after RCI. In conclusion, human ghrelin is beneficial in a rat model of RCI. The protective effect of human ghrelin appears to be attributed to re-balancing the dysregulated sympathetic/parasympathetic nervous systems. PMID:19779631

  7. Campylobacter fetus infections in humans: exposure and disease.

    PubMed

    Wagenaar, Jaap A; van Bergen, Marcel A P; Blaser, Martin J; Tauxe, Robert V; Newell, Diane G; van Putten, Jos P M

    2014-06-01

    Campylobacter fetus can cause intestinal illness and, occasionally, severe systemic infections. Infections mainly affect persons at higher risk, including elderly and immunocompromised individuals and those with occupational exposure to infected animals. Outbreaks are infrequent but have provided insight into sources. Source attribution of sporadic cases through case-control interviews has not been reported. The reservoirs for C. fetus are mainly cattle and sheep. Products from these animals are suspected as sources for human infections. Campylobacter fetus is rarely isolated from food, albeit selective isolation methods used in food microbiology are not suited for its detection. We hypothesize that the general population is regularly exposed to C. fetus through foods of animal origin, cross-contaminated foodstuffs, and perhaps other, as yet unidentified, routes. Campylobacter fetus infection should be suspected particularly in patients with nonspecific febrile illness who are immunocompromised or who may have been occupationally exposed to ruminants. PMID:24550377

  8. Population exposure to ultraviolet radiation in Finland 1920-1995: Exposure trends and a time-series analysis of exposure and cutaneous melanoma incidence

    SciTech Connect

    Kojo, Katja [STUK-Radiation and Nuclear Safety Authority, 00881 Helsinki (Finland) and School of Public Health, University of Tampere, 33014 Tampere (Finland)]. E-mail: katja.kojo@uta.fi; Jansen, Christer T. [Department of Dermatology, University of Turku, 20540 Turku (Finland); Nybom, Pia [University of Art and Design, 00560 Helsinki (Finland); Huurto, Laura [STUK-Radiation and Nuclear Safety Authority, 00881 Helsinki (Finland); Laihia, Jarmo [Department of Dermatology, University of Turku, 20540 Turku (Finland); Ilus, Taina [STUK-Radiation and Nuclear Safety Authority, 00881 Helsinki (Finland); Auvinen, Anssi [STUK-Radiation and Nuclear Safety Authority, 00881 Helsinki (Finland); School of Public Health, University of Tampere, 33014 Tampere (Finland)

    2006-05-15

    Ultraviolet radiation (UVR) is the principal cause of cutaneous malignant melanoma (CMM). However, the relation between CMM and UVR exposure is not clear. We present the trends of population exposure to UVR and conduct a time-series analysis of the relation between UVR exposure and incidence of CMM. Data on CMM incidence were obtained from the Finnish Cancer Registry. Clothing coverage of the body was scored from archival photographs and the proportion of uncovered skin was used as a measure of solar exposure. Information on the number of sunny resort holidays, duration of annual holidays, and sunscreen sales were obtained from various sources. Exposed skin area doubled from 1920 to 1985. The average duration of annual holidays increased 30-fold. The number of sunny resort holidays and the sales of sunscreens increased rapidly from 1980. CMM was most strongly associated with solar exposure of 5-19 years earlier. There is a considerable decrease in clothing coverage during the 20th century. UVR exposure preceding CMM occurrence 4 years or less does not appear relevant, whereas the period 5-19 years prior to CMM occurrence might be the most relevant period. However, findings of ecological studies may not be applicable at the individual level.

  9. The risk of childhood cancer from intrauterine and preconceptional exposure to ionizing radiation.

    PubMed Central

    Wakeford, R

    1995-01-01

    The findings of studies investigating whether exposures to ionizing radiation before birth, either pre- or post-conception, increase the risk of childhood cancer have provoked much scientific controversy. An epidemiological association between the abdominal exposure of pregnant women to diagnostic X-rays and childhood cancer was first reported in the 1950s, while an association between the recorded dose of radiation received occupationally by fathers before the conception of their offspring and childhood leukemia was reported only recently in 1990. The scientific interpretation of these particular statistical associations is by no means straightforward, but the latest analyses of intrauterine irradiation and childhood cancer indicate that a causal inference is likely. Scientific committees have adopted risk coefficients for the intrauterine exposure of somatic tissues, which for childhood leukemia are comparable to those accepted for exposure in infancy, although questions remain about the level of risk of childhood solid tumors imparted by exposure to radiation in utero and shortly after birth. In contrast, the association between paternal preconceptional radiation dose and childhood leukemia has not been confirmed by studies using objectively determined doses. The original association has been found to be restricted to children born in one village, it does not extend to cancers other than leukemia, and it is markedly inconsistent with the established body of knowledge on radiation-induced hereditary disease. A causal interpretation of this association has effectively been abandoned by scientific authorities. Images p1018-a PMID:8605850

  10. TOXICOLOGY LABORATORY ANALYSIS AND HUMAN EXPOSURE TO p-CHLOROANILINE

    PubMed Central

    Pizon, AF; Schwartz, AR; Shum, LR; Rittenberger, JC; Lower, DR; Giannoutsos, S; Virji, MA; Krasowski, MD

    2008-01-01

    Introduction p-Chloroaniline is more potent at producing methemoglobin than aniline in animal models. This case highlights the clinical presentation of an inhalation exposure to p-chloroaniline and associated laboratory analysis. An in-vitro study evaluating the metabolism of p-chloroaniline in human hepatocytes was undertaken to evaluate the metabolic fate more closely. Case Presentation A 20 year-old man was working at a chemical waste plant when he developed dizziness, abdominal pain, and nausea. The exam was remarkable for coma, tachycardia, cyanosis and pulse oximetry of 75%. Arterial blood gases showed a pH 7.38, pCO2 41 mmHg, pO2 497 mmHg, bicarbonate 24 mEq/L and methemoglobin 69%. Methylene blue administration led to complete recovery without sequelae. p-Chloroaniline was later identified as the chemical involved. He denied direct contact with the chemical, but was not wearing a dust mask or respirator. GC/MS confirmed p-chloroaniline and metabolites in the patient’s urine. Methods Human hepatocytes were incubated with 100 µM p-chloroaniline for 24 hours, in both rifampicin- and vehicle only-treated cells. The cell culture medium was collected for GC/MS analysis for p-chloroaniline metabolites. Results Similar to the patient sample, both p-chloroaniline and p-chloroacetanilide were identified by GC/MS in hepatocytes incubated with p-chloroaniline. Neither p-chloroaniline incubated in empty cell culture nor direct GC/MS injection of p-chloroaniline generated any p-chloroacetanilide via non-enzymatic degradation. Discussion/Conclusion The seemingly innocuous dermal and inhalation exposure to p-chloroaniline dust can lead to life-threatening methemoglobinemia. The diagnosis can be confirmed with GC/MS analysis of the patient’s urine, searching for p-chloroaniline and its primary metabolite p-chloroacetanilide. PMID:18608262

  11. Influence of environmental exposure on human epigenetic regulation.

    PubMed

    Marsit, Carmen J

    2015-01-01

    Environmental toxicants can alter epigenetic regulatory features such as DNA methylation and microRNA expression. As the sensitivity of epigenomic regulatory features may be greatest during the in utero period, when critical windows are narrow, and when epigenomic profiles are being set, this review will highlight research focused on that period. I will focus on work in human populations, where the impact of environmental toxicants in utero, including cigarette smoke and toxic trace metals such as arsenic, mercury and manganese, on genome-wide, gene-specific DNA methylation has been assessed. In particular, arsenic is highlighted, as this metalloid has been the focus of a number of studies and its detoxification mechanisms are well understood. Importantly, the tissues and cells being examined must be considered in context in order to interpret the findings of these studies. For example, by studying the placenta, it is possible to identify potential epigenetic adaptations of key genes and pathways that may alter the developmental course in line with the developmental origins of health and disease paradigm. Alternatively, studies of newborn cord blood can be used to examine how environmental exposure in utero can impact the composition of cells within the peripheral blood, leading to immunological effects of exposure. The results suggest that in humans, like other vertebrates, there is a susceptibility for epigenomic alteration by the environment during intrauterine development, and this may represent a mechanism of plasticity of the organism in response to its environment as well as a mechanism through which long-term health consequences can be shaped. PMID:25568453

  12. Experimental studies on lung carcinogenesis and their relationship to future research on radiation-induced lung cancer in humans

    SciTech Connect

    Cross, F.T.

    1991-03-01

    The usefulness of experimental systems for studying human lung carcinogenesis lies in the ease of studying components of a total problem. As an example, the main thrust of attack on possible synergistic interactions between radiation, cigarette smoke, and other irritants must be by means of research on animals. Because animals can be serially sacrificed, a systematic search can be made for progressive lung changes, thereby improving our understanding of carcinogenesis. The mechanisms of radiation-induced carcinogenesis have not yet been delineated, but modern concepts of molecular and cellular biology and of radiation dosimetry are being increasingly applied to both in vivo and in vitro exposure to determine the mechanisms of radiation-induced carcinogenesis, to elucidate human data, and to aid in extrapolating experimental animal data to human exposures. In addition, biologically based mathematical models of carcinogenesis are being developed to describe the nature of the events leading to malignancy; they are also an essential part of a rational approach to quantitative cancer risk assessment. This paper summarizes recent experimental and modeling data on radon-induced lung cancer and includes the confounding effects of cigarette-smoke exposures. The applicability of these data to understanding human exposures is emphasized, and areas of future research on human radiation-induced carcinogenesis are discussed. 7 refs., 2 figs., 3 tabs.

  13. Quantitative Proteomic Profiling of Low Dose Ionizing Radiation Effects in a Human Skin Model

    SciTech Connect

    Hengel, Shawna; Aldrich, Joshua T.; Waters, Katrina M.; Pasa-Tolic, Ljiljana; Stenoien, David L.

    2014-07-29

    To assess molecular responses to low doses of radiation that may be encountered during medical diagnostic procedures, nuclear accidents, or terrorist acts, a quantitative global proteomic approach was used to identify protein alterations in a reconstituted human skin tissue treated with 10 cGy of ionizing radiation. Subcellular fractionation was employed to remove highly abundant structural proteins and provide insight on radiation induced alterations in protein abundance and localization. In addition, peptides were post-fractionated using high resolution 2-dimensional liquid chromatography to increase the dynamic range of detection of protein abundance and translocation changes. Quantitative data was obtained by labeling peptides with 8-plex isobaric iTRAQ tags. A total of 207 proteins were detected with statistically significant alterations in abundance and/or subcellular localization compared to sham irradiated tissues. Bioinformatics analysis of the data indicated that the top canonical pathways affected by low dose radiation are related to cellular metabolism. Among the proteins showing alterations in abundance, localization and proteolytic processing was the skin barrier protein filaggrin which is consistent with our previous observation that ionizing radiation alters profilaggrin processing with potential effects on skin barrier functions. In addition, a large number of proteases and protease regulators were affected by low dose radiation exposure indicating that altered proteolytic activity may be a hallmark of low dose radiation exposure. While several studies have demonstrated altered transcriptional regulation occurs following low dose radiation exposures, the data presented here indicates post-transcriptional regulation of protein abundance, localization, and proteolytic processing play an important role in regulating radiation responses in complex human tissues.

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

    SciTech Connect

    Woo, Tony [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); Pignol, Jean-Philippe [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada)]. E-mail: Jean-Philippe.Pignol@sw.ca; Rakovitch, Eileen [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); Vu, Toni [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); Hicks, Deanna [Department of Radiation Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); O'Brien, Peter [Department of Medical Physics, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada); Pritchard, Kathleen [Department of Medical Oncology, Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario (Canada)

    2006-05-01

    Purpose: Recent reports demonstrate a dramatically increased rate of secondary leukemia for breast cancer patients receiving adjuvant high-dose anthracycline and radiotherapy, and that radiation is an independent factor for the development of leukemia. This study aimed to evaluate the radiation body exposure during breast radiotherapy and to characterize the factors associated with an increased exposure. Patients and Methods: In a prospective cohort of 120 women, radiation measurements were taken from four sites on the body at the time of adjuvant breast radiotherapy. Multiple regression analysis was performed to analyze patient and treatment factors associated with the amount of scattered radiation. Results: For standard 50 Gy breast radiotherapy, the minimal dose received by abdominal organs is on average 0.45 Gy, ranging from 0.06 to 1.55 Gy. The use of physical wedges as a compensation technique was the most significant factor associated with increased scattered dose (p < 0.001), resulting in approximately three times more exposure compared with breast intensity-modulated radiation therapy (IMRT) and dynamic wedge. Conclusions: The amount of radiation that is scattered to a patient's body is consistent with exposure reported to be associated with excess of leukemia. In accordance with the As Low As Reasonably Achievable (ALARA) principle, we recommend using breast IMRT or virtual wedging for the radiotherapy of breast cancer receiving high-dose anthracycline chemotherapy.

  15. Neurotoxicity of human neural cells induced by space radiation: in vitro risk assessment and countermeasure

    NASA Astrophysics Data System (ADS)

    Guida, P.; Vazquez, M.; Kim, A.

    As the duration of space missions increases the potential for neurological damage to astronauts resulting from exposure to radiation also increases To explore the cytotoxic effects of low and high LET radiation on cells of the central nervous system we utilized a model in vitro system consisting of a human neuronal progenitor cell line NT2 and its terminally differentiated derivative hNT neurons We found that exposure to numerous forms of ionizing radiation induced cell detachment necrosis and apoptosis in time dose and LET dependent manners From the slopes of the dose-response curves we calculated RBE values for each form of heavy ion radiation A sequential field of 1 GeV n protons and iron ions induced apoptosis to a greater extent than either ion alone and the time between hits was also an important determining factor In addition cycling neuronal progenitor cells underwent a dramatic G2 phase specific cell cycle delay within 6 hours following exposure to either low or high LET radiation The molecular effects of HZE radiation were also investigated with an emphasis on the cell stress response protein p53 Heavy ion radiation induced expression of p53 in a time and dose dependent manner in both neuronal progenitor and mature neuronal cells Furthermore several post-translational modifications to the p53 protein were detected 2 hours after exposure to gamma rays Experiments incorporating pifithrin- alpha a small molecule inhibitor of p53 suggest that induction of both apoptosis and the cell cycle delay in human NT2 cells is

  16. A comparison of quality factors and weighting factors for characterizing astronaut radiation exposures

    NASA Technical Reports Server (NTRS)

    Zapp, Neal; Cucinotta, Frank; Atwell, W.

    2002-01-01

    Radiation exposures are typically characterized by two quantities. The first is the absorbed dose, or the energy deposited per unit mass for specific types of radiation passing through specified materials. The same amount of energy deposited in material by two different types of radiation, however, can result in two different levels of risk. Because of this, for the purpose of radiation protection operations, absorbed dose is modified by a second factor intended to normalize the risk associated with a given exposure. We present here an inter-comparison of methods for this modification. First is the radiation quality factor (Q), as defined by ICRP publication 60. This quantity is related functionally to the unrestricted linear energy transfer (LET) of a given radiation, and is multiplied by the absorbed dose to derive the dose equivalent (H). The second method for modifying absorbed dose is the radiation weighting factor, also given in ICRP-60, or as modified in NCRP report 115. To implement the weighting factor, the absorbed dose resulting from incidence of a particular radiation is multiplied by a factor assigned to that type of radiation, giving the equivalent dose. We compare calculations done based on identical fields of radiation representative of that encountered by the MIR space station, applying each of these two methods. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  17. Radiation hybrid panel for human chromosome 19

    SciTech Connect

    Jackson, C.L.; Mark, H.F.L.; Cha, C. [Rhode Island Hospital, Providence, RI (United States)]|[Brown Univ., Providence, RI (United States)] [and others

    1994-09-01

    Radiation hybrid cell lines have proven to be excellent resources for the physical mapping and the isolation of markers from specific chromosomal regions. We have produced radiation hybrids from a monochromosomal microcell hybrid containing chromosome 19. The human chromosome was marked with a retroviral vector containing a dominant selectable marker. The hybrids were produced using doses of radiation ranging from 1000 to 8000 rads and selection for the exogenous marker. A panel of approximately 90 hybrids was characterized using marker analysis. In addition, a subset was analyzed by fluorescent in situ hybridization (FISH). These methods allowed us to identify the number of chromosome fragments and the region of the chromosome contained in the hybrids. The panel has been tested for 50 chromosome 19 markers from known locations on the chromosome using the polymerase chain reaction and Southern blotting. We will continue to test the hybrid panel for additional markers. Microsatellite markers as well as anonymous DNA sequences and genes have been tested. Hybrids have been isolated which appear to contain only 1 or 2 markers from the short arm of the chromosome where the selectable marker is inserted. Cloning of the DNA flanking the exogenous retrovirus was carried out by taking advantage of the tRNA suppressor gene incorporated into the vector. FISH of the phage clone containing flanking DNA hybridized to metaphase spreads of the hybrid localized the insertion site to 19p13.1. The hybrid panel that we have produced will aid in the physical mapping of chromosome 19 and region-specific cloning.

  18. Non-Ionizing Radiation: Evaluation of General Public's Exposures in Greece and Albania

    NASA Astrophysics Data System (ADS)

    Ylli, Fatos; Karabetsos, Efthymios; Dollani, Kostandin; Koutounidis, Dimitris

    2010-01-01

    With the growth of electric power generation and transmission, the development of new telecommunication systems and advances in medical and industrial applications, humans are increasingly exposed to electromagnetic fields (EMF). The need to understand the potentially harmful effects of EMF on human health has been met by several decades of research, but the development of exposure standards is more recent and a variety of national standards now exist. A number of organizations have formulated guidelines establishing limits for occupational and residential EMF exposure. The exposure limits for EMF developed by the ICNIRP were based in large reviews of scientific literature, including thermal and non-thermal effects.

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

    PubMed Central

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

    2014-01-01

    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

  20. Human milk as a source of methylmercury exposure in infants

    SciTech Connect

    Grandjean, P. (Odense Univ. (Denmark)); Jorgensen, P.J. (Odense Univ. Hospital (Denmark)); Weihe, P. (Landssjukrahusid, Torshavn (Faroe Islands))

    1994-01-01

    As methylmercury is excreted in human milk and infants are particularly susceptible to toxicity due to this compound, the purpose of this study was to evaluate the possible transfer of methylmercury to infants via breast-feeding. In a community with a high intake of seafood, 583 children from a birth cohort were followed. The duration of nursing was recorded, and hair samples were obtained for mercury analysis at approximately 12 months of age. The hair mercury concentrations increased with the length of the nursing period, and those nursed throughout the first year showed the highest geometric mean (9.0 nmol/g or 1.8 [mu]g/g). Human milk therefore seems to be an important source of methylmercury exposure in infants. As increasing time interval from weaning to hair sample collection was not associated with any detectable decrease in mercury concentrations. A slow or absent elimination of methylmercury during the first year after birth could explain this finding. In certain fishing communities, infants nursed for long periods may be at increased risk of developing methylmercury toxicity. 25 refs., 2 figs., 3 tabs.

  1. The Progression of Circadian Phase during Light Exposure in Animals and Humans

    Microsoft Academic Search

    Domien G. M. Beersma; Marian Comas; Roelof A. Hut; Marijke C. M. Gordijn; Melanie Rueger; Serge Daan

    2009-01-01

    Studies in humans and mice revealed that circadian phase shifting effects of light are larger at the beginning of a light exposure interval than during subsequent exposure. Little is known about the dynamics of this response reduction phenomenon. Here the authors propose a method to obtain information on the progression of phase during light exposure. Phase response curves to intervals

  2. Modeling Human Exposure to Phthalate Esters: A Comparison of Indirect and Biomonitoring Estimation Methods

    Microsoft Academic Search

    Kathryn E. Clark; Raymond M. David; Richard Guinn; Kurt W. Kramarz; Mark A. Lampi; Charles A. Staples

    2011-01-01

    Humans are potentially exposed to phthalate esters (PEs) through ingestion, inhalation, and dermal contact. Studies quantifying exposure to PEs include “biomarker studies” and “indirect studies.” Biomarker studies use measurements of PE metabolites in urine to back-calculate exposure to the parent diester, while indirect studies use the concentration of the PE in each medium of exposure and the rate of intake

  3. Invited Editorial: Radiation exposures of aircrew in high altitude flight

    Microsoft Academic Search

    Lawrence W. Townsend

    2001-01-01

    Introduction Background radiation levels in the atmosphere vary in intensity with latitude, altitude and phase of the solar cycle. These background levels are generated primarily by galactic cosmic rays (GCR), consisting of energetic nuclei of all naturally occurring elements, interacting with atmospheric constituents, primarily through atomic and nuclear collisions. Cosmic rays were discovered in 1912, about the same time that

  4. ASSESSMENT OF ULTRAVIOLET RADIATION EXPOSURES IN PHOTOBIOLOGICAL EXPERIMENTS

    Microsoft Academic Search

    J. C. F. Wong; A. V. Parisi

    The interfering effect of ultraviolet (UV) radiation on the natural function of biological processes is wavelength specific and the UV spectrum must be weighted with the action spectrum for the process. The UV spectral irradiance may be measured with calibrated spectroradiometers. Alternatively, the biologically effective UV may be measured with broadband devices. This paper reviews the techniques for assessing biologically

  5. Development of human epithelial cell systems for radiation risk assessment

    Microsoft Academic Search

    C. H. Yang; L. M. Craise

    1994-01-01

    The most important health effect of space radiation for astronauts is cancer induction. For radiation risk assessment, an understanding of carcinogenic effect of heavy ions in human cells is most essential. In our laboratory, we have successfully developed a human mammary epithelial cell system for studying the neoplastic transformation in vitro. Growth variants were obtained from heavy ion irradiated immortal

  6. Stimulation of the human auditory nerve with optical radiation

    Microsoft Academic Search

    Andrew Fishman; Piotr Winkler; Jozef Mierzwinski; Wojciech Beuth; Agnella Izzo Matic; Zygmunt Siedlecki; Ingo Teudt; Hannes Maier; Claus-Peter Richter

    2009-01-01

    A novel, spatially selective method to stimulate cranial nerves has been proposed: contact free stimulation with optical radiation. The radiation source is an infrared pulsed laser. The Case Report is the first report ever that shows that optical stimulation of the auditory nerve is possible in the human. The ethical approach to conduct any measurements or tests in humans requires

  7. Gender Classification Based on Human Radiation Wave Analysis

    Microsoft Academic Search

    Siti Zura A. Jalil; Mohd Nasir Taib; Hasnain Abdullah Idris; Megawati Mohd Yunus

    2011-01-01

    This paper describes an analysis of body radiation frequency for the purpose of gender classification. The human radiation frequency is experimentally studied from 33 healthy human subjects of 17 males and 16 females. KNN classifier is employed for gender classification. The number of training to testing ratio was evaluated at 50 to 50, 60 to 40 and 70 to 30,

  8. Occupational radiation exposure history of Idaho Field Office Operations at the INEL

    SciTech Connect

    Horan, J.R.; Braun, J.B.

    1993-10-01

    An extensive review has been made of the occupational radiation exposure records of workers at the Idaho National Engineering Laboratory (INEL) over the period of 1951 through 1990. The focus has been on workers employed by contractors and employees of the Idaho Field Operations Office (ID) of the United States Department of Energy (USDOE) and does not include the Naval Reactors Facility (NRF), the Argonne National Laboratory (ANL), or other operations field offices at the INEL. The radiation protection guides have decreased from 15 rem/year to 5 rem/year in 1990 for whole body penetrating radiation exposure. During these 40 years of nuclear operations (in excess of 200,000 man-years of work), a total of twelve individuals involved in four accidents exceeded the annual guidelines for exposure; nine of these exposures were received during life saving efforts on January 3, 1961 following the SL-1 reactor accident which killed three military personnel. These exposures ranged from 8 to 27 rem. Only one individual has exceeded the annual whole body penetrating radiation protection guidelines in the last 29 years.

  9. Handheld X-ray Fluorescence Spectrometers: Radiation Exposure Risks of Matrix-Specific Measurement Scenarios.

    PubMed

    Rouillon, Marek; Kristensen, Louise J; Gore, Damian B

    2015-07-01

    This study investigates X-ray intensity and dispersion around handheld X-ray fluorescence (XRF) instruments during the measurement of a range of sample matrices to establish radiation exposure risk during operation. Four handheld XRF instruments representing three manufacturers were used on four smooth, flat-lying materials of contrasting matrix composition. Dose rates were measured at 10, 20, 30, and 40 cm intervals every 30° around the instrument at 0 and 45° from the horizontal, as well as vertically from the instrument screen. The analysis of polyethylene recorded dose rates 156 times higher (on average) than steel measurements and 34 times higher than both quartz sand and quartz sandstone. A worst-case exposure scenario was assumed where a user analyses a polyethylene material at arms reach for 1 h each working day for one year. This scenario resulted in an effective body dose of 73.5 ?Sv, equivalent to three to four chest X-rays (20 ?Sv) a year, 20 times lower than the average annual background radiation exposure in Australia and well below the annual exposure limit of 1 mSv for non-radiation workers. This study finds the advantages of using handheld XRF spectrometers far outweighs the risk of low radiation exposure linked to X-ray scattering from samples. PMID:26037330

  10. Radiation exposures for DOE and DOE contractor employees, 1990. Twenty-third annual report

    SciTech Connect

    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)

    1994-03-01

    This is the 23rd in a series of annual radiation exposure reports published by the Department of Energy (DOE) or its predecessors. This report summarizes the radiation exposures received by both employees and visitors at DOE and DOE contractor facilities during 1990. Trends in radiation exposures are evaluated by comparing the doses received in 1990 to those received in previous years. 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 estimated from expert groups. This report is the third that is based on detailed exposure data for each individual monitored at a DOE facility. Prior to 1988, only summarized data from each facility were available. This report contains information on different types of radiation doses, including total effective, internal, penetrating, shallow, neutron, and extremity doses. It also contains analysis of exposures by age, sex, and occupation of the exposed individuals. This report also continues the precedent established in the Twenty-First (1988) Annual Report by conducting a detailed, one-time review and analysis of a particular topic of interest. The special topic for this report is a comparison of total effective, internal, and extremity dose equivalent values against penetrating dose equivalent values.

  11. Radiation risk estimation in human populations: lessons from the radiological accident in Brazil.

    PubMed

    da Cruz, A D; Volpe, J P; Saddi, V; Curry, J; Curadoc, M P; Glickman, B W

    1997-02-01

    The development of radiological and nuclear technologies and the deployment of nuclear weapons have made ionizing radiation one of the most studied human mutagens. Exposure to ionizing radiation produces DNA damage which can result in mutation and cancer, making the risk associated with human exposure a critical issue. In this paper we estimate the risk associated with radiation exposure for individuals exposed to 137Cs during the 1987 Goiânia radiological accident. Using combined regression slopes from both the in vivo hprt mutant frequency and micronucleus frequency data we estimated a doubling dose of 173 (+/-47) cGy for these two endpoints. This is in close agreement with the published estimates for low dose rate and chronic exposure to low-LET radiation. We obtained risk estimates of about 24-fold increase in dominant disorders in the post-exposure generation of the directly exposed population. No detectable increase was found in the population at large. The risk of carcinogenesis in the directly exposed population was found to be increased by a factor in the range of 1.4 to 1.5. The small sample size in this study requires a large element of caution with respect to risk estimates interpretation. Moreover, the doubling dose estimates prepared here are derived from lymphocytes. This somatic data may require additional considerations for both cancer and certainly germ-line events. Nevertheless, the risk of carcinogenesis and genetic harm for this population are good indicators of the potential genetic damage imposed by ionizing radiation to the Goiânia population. PMID:9042402

  12. Human exposure to piroplasms in Central and Northern Italy.

    PubMed

    Gabrielli, Simona; Calderini, Pietro; Cassini, Rudi; Galuppi, Roberta; Tampieri, Maria Paola; Pietrobelli, Mario; Cancrini, Gabriella

    2014-01-01

    TA serosurvey has been conducted in Northern and Central Italy to investigate the presence in humans of antibodies against zoonotic Babesia and Theileria species. The study focused on a total of 432 volunteers, of which 290 were persistently exposed to tick bites because of their jobs (forester employees, livestock keepers, veterinary practitioners, farmers and hunters) and 142 resident in the same area less frequently exposed. An indirect fluorescent antibody test (IFAT) for humans was used to detect antibodies to Babesia microti, IFAT tests for veterinary use were modified to detect reactivity to Babesia bovis, Babesia canis and Theileria equi. A laboratory-derived ELISA was employed to detect antibodies to Babesia divergens. Both reactive and 10 negative sera were analysed against plasmodial antigens to evaluate possible aspecificity. A high reactivity to piroplasm antigens was found, showing significant difference between the sera of the two groups of volunteers (24% vs 7.%; p<0.001). No cross-reactivity was observed, while each professional group showed reactivity that would fit with the professional risk exposure. In particular, a high reactivity to B. microti and B. divergens antigens was observed in foresters and hunters (32% and 12%, respectively). This is the first report on the human seroreactivity to piroplasms in Italy; it also provides additional epidemiological information on these tick-borne zoonoses in Europe. Our findings suggest the possible occurrence of piroplasm infections in Italy and alert physicians to consider these otherwise neglected parasitic diseases when dealing with any febrile illness, especially in subjects exposed to tick bites. PMID:24715592

  13. Effects of ?-Particle Radiation on MicroRNA Responses in Human Cell-Lines.

    PubMed

    Chauhan, Vinita; Howland, Matthew; Wilkins, Ruth

    2012-01-01

    A variety of alpha (?)-particle emitters are found ubiquitously in the environment, in commercial/therapeutic prod-ucts and are a potential threat in the form of a radiological dispersal device. Our understanding of the biological mechanisms and long-term health effects resulting from ?-particle exposure is limited. Exposure to radiation induces modulations of gene networks, possibly through microRNAs (miRNAs), which could be targets for studying biological effects. In this study, changes in miRNA expression patterns after 0.5 Gy, 1.0 Gy and 1.5 Gy of ?-particle radiation at a low dose-rate of exposure in three human cell-lines (A549, THP-1 and HFL) were investigated. The screening of 1,145 miRNAs across three human cell-lines resulted in unique, cell-specific responses with no overlap in miRNA expression observed in the three cell-lines. Prediction analysis suggests these ?-particle induced miRNA mapped to target genes related to ribosomal assembly, lung carcinoma development, cell communication and keratin sulfate biosynthesis. Taken together, these results suggest that exposure to ?-particle radiation results in cell-type specific responses in gene network regulatory processes. PMID:22481983

  14. Development of human epithelial cell systems for radiation risk assessment

    NASA Technical Reports Server (NTRS)

    Yang, C. H.; Craise, L. M.

    1994-01-01

    The most important health effect of space radiation for astronauts is cancer induction. For radiation risk assessment, an understanding of carcinogenic effect of heavy ions in human cells is most essential. In our laboratory, we have successfully developed a human mammary epithelial cell system for studying the neoplastic transformation in vitro. Growth variants were obtained from heavy ion irradiated immortal mammary cell line. These cloned growth variants can grow in regular tissue culture media and maintain anchorage dependent growth and density inhibition property. Upon further irradiation with high-Linear Energy Transfer (LET) radiation, transformed foci were found. Experimental results from these studies suggest that multiexposure of radiation is required to induce neoplastic tranformation of human epithelial cells. This multihits requirement may be due to high genomic stability of human cells. These growth variants can be useful model systems for space flight experiments to determine the carcinogenic effect of space radiation in human epithelial cells.

  15. THE NATIONAL HUMAN EXPOSURE ASSESSMENT SURVEY (NHEXAS) STUDY IN ARIZONA-INTRODUCTION AND PRELIMINARY RESULTS

    EPA Science Inventory

    The objective of the National Human Exposure Assessment Survey (NHEXAS) in Arizona is to determine the multimedia distribution of total human exposure to environmental pollutants in the classes of metals, pesticides, and volatile organic compounds (VOCs) for the population of Ari...

  16. MODELING HUMAN EXPOSURES AND DOSE USING A 2-DIMENSIONAL MONTE-CARLO MODEL (SHEDS)

    EPA Science Inventory

    Since 1998, US EPA's National Exposure Research Laboratory (NERL) has been developing the Stochastic Human Exposure and Dose Simulation (SHEDS) model for various classes of pollutants. SHEDS is a physically-based probabilistic model intended for improving estimates of human ex...

  17. A NEW METHOD OF LONGITUDINAL DIARY ASSEMBLY FOR HUMAN EXPOSURE MODELING

    EPA Science Inventory

    Human exposure time-series modeling requires longitudinal time-activity diaries to evaluate the sequence of concentrations encountered, and hence, pollutant exposure for the simulated individuals. However, most of the available data on human activities are from cross-sectional su...

  18. Risk for Avian Influenza Virus Exposure at Human–Wildlife Interface

    PubMed Central

    Siembieda, Jennifer; Johnson, Christine K.; Boyce, Walter; Sandrock, Christian

    2008-01-01

    To assess risk for human exposure to avian influenza viruses (AIV), we sampled California wild birds and marine mammals during October 2005–August 2007and estimated human–wildlife contact. Waterfowl hunters were 8 times more likely to have contact with AIV-infected wildlife than were persons with casual or occupational exposures (p<0.0001). PMID:18598646

  19. Collection and Use of Exposure Data from Human Milk Biomonitoring in the United States

    Microsoft Academic Search

    Suzanne E. Fenton; Marian Condon; Adrienne S. Ettinger; Judy S. LaKind; Ann Mason; Melissa McDiarmid; Zhengmin Qian; Sherry G. Selevan

    2005-01-01

    Human milk is a unique biological matrix that can be used to estimate exposures in both the mother and the breastfed infant. In addition, the presence of environmental chemicals in human milk may act as a sentinel for exposures to a broader population. Several factors play a role in determining the quantity of chemicals transferred to milk and, subsequently, to

  20. The measurement of radiation exposure of astronauts by radiochemical techniques

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.

    1972-01-01

    The principal gamma-ray emitting radioisotopes, produced in the body of astronauts by cosmic-ray bombardment, which have half-lives long enough to be useful for radiation dose evaluation, are Be-7, Na-22, and Na-24. The sodium isotopes were measured in the preflight and postflight urine and feces, and those feces specimens collected during the manned Apollo missions, by analysis of the urine salts and the raw feces in large crystal multidimensional gamma-ray spectrometers. The Be-7 was chemically separated, and its concentration measured in an all NaI (TL), anticoincidence shielded, scintillation well crystal. The astronaut radiation dose in millirads, as determined for the Apollo 7, 8, 9, 10, 11, 12, and 13 missions, was 330, 160, smaller than 315, 870 plus or minus 550, 31, 110, and smaller than 250, respectively.

  1. Cytogenetic and Carcinogenic Effects of Exposure to Radiofrequency Radiation

    Microsoft Academic Search

    JAMES P. MCNAMEE; PASCALE V. BELLIER

    Radiofrequency radiation (RFR) is a portion of the electromagnetic spectrum with frequencies of 3 kHz–300 GHz. RFR is produced\\u000a by many man-made sources, including mobile phones and base stations, television and radio broadcasting facilities, radar,\\u000a medical equipment, microwave ovens, radiofrequency heaters as well as a diverse variety of other electronic devices within\\u000a our living and working environments. Owing to ongoing

  2. ALVEOLAR BREATH SAMPLING AND ANALYSIS IN HUMAN EXPOSURE ASSESSMENT STUDIES

    EPA Science Inventory

    Alveolar breath sampling and analysis can be extremely useful in exposure assessment studies involving volatile organic compounds (VOCs). Over recent years scientists from the EPA's National Exposure Research Laboratory have developed and refined an alveolar breath collection ...

  3. The measurement of radiation exposure of astronauts by radiochemical techniques

    NASA Technical Reports Server (NTRS)

    Brodzinski, R. L.

    1972-01-01

    Cosmic radiation doses to the crews of the Apollo 14, 15, and 16 missions of 142 + or - 80, 340 + or - 80, and 210 + or - 130 mR respectively were calculated from the specific activities of Na-22 and Na-24 in the postflight urine specimens of the astronauts. The specific activity of Fe-59 was higher in the urine than in the feces of the Apollo 14 and 15 astronauts, and a possible explanation is given. The concentrations of K-40, K-42, Cr-51, Co-60, and Cs-137 in the urine are also reported for these astronauts. The radiation doses received by pilots and navigators flying high altitude missions during the solar flare of March 27 to 30, 1972 were calculated from the specific activity of Na-24 in their urine. These values are compared with the expected radiation dose calculated from the known shape and intensity of the proton spectrum and demonstrate the magnitude of atmospheric shielding. The concentrations of Na, K, Rb, Cs, Fe, Co, Ag, Zn, Hg, As, Sb, Se, and Br were measured in the urine specimens from the Apollo 14 and 15 astronauts by neutron activation analysis. The mercury and arsenic levels were much higher than expected.

  4. Development of a software based automatic exposure control system for use in image guided radiation therapy

    NASA Astrophysics Data System (ADS)

    Morton, Daniel R.

    Modern image guided radiation therapy involves the use of an isocentrically mounted imaging system to take radiographs of a patient's position before the start of each treatment. Image guidance helps to minimize errors associated with a patients setup, but the radiation dose received by patients from imaging must be managed to ensure no additional risks. The Varian On-Board Imager (OBI) (Varian Medical Systems, Inc., Palo Alto, CA) does not have an automatic exposure control system and therefore requires exposure factors to be manually selected. Without patient specific exposure factors, images may become saturated and require multiple unnecessary exposures. A software based automatic exposure control system has been developed to predict optimal, patient specific exposure factors. The OBI system was modelled in terms of the x-ray tube output and detector response in order to calculate the level of detector saturation for any exposure situation. Digitally reconstructed radiographs are produced via ray-tracing through the patients' volumetric datasets that are acquired for treatment planning. The ray-trace determines the attenuation of the patient and subsequent x-ray spectra incident on the imaging detector. The resulting spectra are used in the detector response model to determine the exposure levels required to minimize detector saturation. Images calculated for various phantoms showed good agreement with the images that were acquired on the OBI. Overall, regions of detector saturation were accurately predicted and the detector response for non-saturated regions in images of an anthropomorphic phantom were calculated to generally be within 5 to 10 % of the measured values. Calculations were performed on patient data and found similar results as the phantom images, with the calculated images being able to determine detector saturation with close agreement to images that were acquired during treatment. Overall, it was shown that the system model and calculation method could potentially be used to predict patients' exposure factors before their treatment begins, thus preventing the need for multiple exposures.

  5. Achieving uniform regulation of environmental lead exposure and poisoning in wildlife and humans

    Microsoft Academic Search

    Vernon G. Thomas

    2010-01-01

    Lead from spent ammunition causes preventable lead exposure in wildlife and humans that may ingest it. Nontoxic substitutes\\u000a for lead ammunition exist but are not adopted widely because of hunter opposition. Other forms of lead exposure in the human\\u000a environment have been heavily regulated because there is no safe level of exposure. The use of lead ammunition should be regulated

  6. Natural radioactivity and external gamma radiation exposure at the coastal Red Sea in Egypt.

    PubMed

    Harb, S

    2008-01-01

    Radionuclides which present in different beach sands are sources of external exposure that contribute to the total radiation exposure of human. In this work, superficial samples of beach sand were collected from the Red Sea coastline (Ras Gharib, Hurghada, Safaga, Qusier and Marsa Alam areas) and at 20 km on Qena-Safaga road. The distribution of natural radionuclides in sand beach samples was studied by gamma spectrometry. The activity concentrations of primordial and artificial radionuclides in samples that are collected from the coastal environment of the Red Sea were 19.2 +/- 3 Bq kg(-1) for (210)Pb, 21.1 +/- 1 Bq kg(-1) for (226)Ra, 22.7 +/- 2 Bq kg(-1) for (238)U, 1.0 +/- 0.1 Bq kg(-1) for (235)U, 11.6 +/- 1 Bq kg(-1) for (228)Ra, 13.0 +/- 1 Bq kg(-1) for (228)Th, 12.4 +/- 1 Bq kg(-1) for (232)Th, 930 +/- 32 Bq kg(-1) for (40)K and 1.2 +/- 0.3 Bq kg(-1) for (137)Cs. The mean external gamma-dose rate was 62.5 +/- 3.2 nSv h(-1), 54.4 +/- 2.8 nGy h(-1) Ra equivalent activity (Ra(eq)) was 107 +/- 5.8 Bq kg(-1), 0.86 +/- 0.04 Bq kg(-1) for representative level index (I(gamma)) and effective dose rate was 0.067 +/- 0.003 mSv y(-1) in beach sand red sea, in air due to naturally occurring radionuclides. PMID:18337293

  7. Evaluating the Radiation From Accidental Exposure During a Nondestructive Testing Event.

    PubMed

    Ting, Chien-Yi; Wang, Hsin-Ell; Lin, Jao-Perng; Lin, Chun-Chih

    2015-08-01

    Industrial radiography is a common nondestructive testing (NDT) method used in various industries. An investigation was conducted for a 1999 incident in Taiwan where two workers (Operators A and B) were accidently exposed to an unshielded Ir source while conducting industrial radiography. Operators A and B experienced acute close-range radiation exposure to a source of Ir for 3 h at a strength of 2.33 × 10 Bq. The health of mammary glands, bone marrow, thyroid glands, eyes, and genital organs of these two workers after radiation exposure was examined. Subsequently, Operator A experienced severe radiation injury, including tissue necrosis and keratinization in the fingers, chromosomal abnormalities, reduced blood cell count, diffuse hyperplasia of the thyroid gland, opaque spots in the crystalline lens, and related radiation effects. The results showed that the left index finger and thumb, eyes, and gonads of Operator A were exposed to a radiation dose of about 369-1,070, 23.1-67.4, 2.4-5.3, and 4.2-11.6 Gy, respectively. Effective dose for Operator A was estimated to range from 6.9 to 18.9 Sv. The left fingers, thumb, eyes, and gonads of Operator B were exposed to a radiation dose of 184.9-646.2, 11.8-40.7, 0.49-3.33, and 0.72-7.18 Gy, respectively, and his effective dose was between 2.5 and 11.5 Sv. This accident indicated a major flaw in the control and regulation of radiation safety for conducting NDT industrial radiography in 1999; however, similar problems still exist. Modifications of the Ionizing Radiation Protection Act in Taiwan are suggested in this study to regulate the management of NDT industries, continually educate the NDT workers in radiation safety, and enact notification provisions for medical care systems toward acute radiation exposure events. PMID:26107437

  8. Comparison of Mouse Urinary Metabolic Profiles after Exposure to the Inflammatory Stressors ? Radiation and Lipopolysaccharide

    PubMed Central

    Laiakis, Evagelia C.; Hyduke, Daniel R.; Fornace, Albert J.

    2012-01-01

    Metabolomics on easily accessible biofluids has the potential to provide rapid identification and distinction between stressors and inflammatory states. In the event of a radiological event, individuals with underlying medical conditions could present with similar symptoms to radiation poisoning, prominently nausea, diarrhea, vomiting and fever. Metabolomics of radiation exposure in mice has provided valuable biomarkers, and in this study we aimed to identify biomarkers of lipopolysaccharide (LPS) exposure to compare and contrast with ionizing radiation. LPS treatment leads to a severe inflammatory response and a cytokine storm, events similar to radiation exposure, and LPS exposure can recapitulate many of the responses seen in sepsis. Urine from control mice, LPS-treated mice, and mice irradiated with 3, 8 and 15 Gy of ? rays was analyzed by LCMS, and markers were extracted using SIMCA-P+ and Random Forests. Markers were validated through tandem mass spectrometry against pure chemicals. Five metabolites, cytosine, cortisol, adenine, O-propanoylcarnitine and isethionic acid, showed increased excretion at 24 h after LPS treatment (P < 0.0001, 0.0393, 0.0393, <0.0001 and 0.0004, respectively). Of these, cytosine, adenine and O-propanoylcarnitine showed specificity to LPS treatment when compared to radiation. On the other hand, increased excretion of cortisol after LPS and radiation treatments indicated a rapid systemic response to inflammatory agents. Isethionic acid excretion, however, showed elevated levels not only after LPS treatment but also after a very high dose of radiation (15 Gy), while additional metabolites showed responsiveness to radiation but not LPS. Metabolomics therefore has the potential to distinguish between different inflammatory responses based on differential ion signatures. It can also provide quick and reliable assessment of medical conditions in a mass casualty radiological scenario and aid in effective triaging. PMID:22128784

  9. Effects of Litter Exposure to UV Radiation on Subsequent Microbial Decomposition

    NASA Astrophysics Data System (ADS)

    Lin, Y.; Scarlett, R. D.; King, J. Y.

    2013-12-01

    In arid ecosystems, photodegradation has recently been identified as a key process in ecosystem carbon cycling. Photodegradation directly contributes to organic matter decomposition through photochemical mineralization. However, it remains unclear how photodegradation interacts with biotic decomposition processes. It is commonly thought that photodegradation can facilitate subsequent microbial decomposition, as it can preferentially decompose lignin, a recalcitrant substrate in microbial decomposition. We hypothesized that ultraviolet (UV) radiation exposure would increase the biodegradability of plant litter and that this effect would be greater with longer radiation exposure. In the field at the University of California's Sedgwick Reserve in Santa Ynez, CA, Bromus diandrus litter samples were exposed to two levels of UV radiation using screens: 'UV pass' (transmitting > 81% of UV radiation) and 'UV block' (transmitting < 8% of UV radiation). There were four lengths of UV exposure: 2.5 months (during summer), 4 months (during summer), 6 months, and 12 months. Litter samples were then analyzed for carbon and nitrogen content, fiber fractions, water extractable carbon and nitrogen, and biodegradability. We evaluated the biodegradability of litter using a 30-day laboratory incubation experiment. Litter samples were incubated in the dark in sealed glass microcosms with soil inoculum. The CO2 accumulation in each microcosm headspace was measured every 1-2 days to assess microbial respiration rate. In contrast to our hypothesis, litter exposed under UV block conditions had 28% higher cumulative CO2 production than litter from UV pass when the length of exposure was 2.5 months (P = 0.02, n = 4). Litter from the UV block treatment also tended to show higher cumulative CO2 production than litter from UV pass when the exposure lasted for 4 months (P = 0.10, n = 4). For samples with longer exposure times (6 and 12 months), there was no difference in CO2 production between UV pass and UV block treatments. Litter lignin concentration was not affected by UV treatments, regardless of the length of UV exposure. Interestingly, there was a strong correlation overall between cumulative CO2 production and water extractable nitrogen (WEN, r = 0.841, P <0.01, n = 24). For samples exposed for 2.5 months, litter from the UV block treatment had 27% more WEN than litter from UV pass (P = 0.05, n = 4). It is likely that UV radiation under UV pass conditions inhibited microbial activity on the litter during summer months, thus decreasing nitrogen immobilization rates and, therefore, WEN. Results of this study indicate that exposure to UV radiation does not facilitate subsequent microbial decomposition. In fact, UV radiation exposure during dry, summer months retards subsequent microbial decomposition of litter even under optimal biodegradation conditions, perhaps due to N limitation of microbial activity. The inhibitory effect of UV radiation exposure became less pronounced with longer exposure of litter in the field, likely due to environmental conditions during non-summer months (decreased radiation intensity and higher water availability) that promote microbial activity and ameliorate this inhibitory effect of UV radiation. Further studies are needed to quantify the complex interactions between photodegradation and microbial decomposition.

  10. Ocular and dermatologic health effects of ultraviolet radiation exposure from the ozone hole in southern Chile.

    PubMed Central

    Schein, O D; Vicencio, C; Muñoz, B; Gelatt, K N; Duncan, D D; Nethercott, J; Honeyman, J; Koren, H S; West, S

    1995-01-01

    OBJECTIVES. This study sought to investigate numerous reports emanating from Punta Arenas, Chile (population 110,000, latitude 53 degrees S), that associated acute ocular and dermatologic disease in humans and animals with excess ultraviolet-B (UV-B) exposure in the setting of the thinning of the ozone column. METHODS. Ophthalmologic and dermatologic records in Punta Arenas were systematically reviewed to enumerate sentinel diagnoses potentially associated with UV-B exposure, ocular examinations on representative animal populations were performed, and the ambient UV-B exposure in the region during the time of maximal thinning was estimated. RESULTS. No increase in patient visits or conditions attributable to UV-B exposure was seen for periods of known ozone depletion compared with control periods. Although ambient UV-B exposure was 1.6 to 2.3 times the habitual exposure on individual days, this excess exposure conferred only a 1% increase in annual exposure on the region. CONCLUSION. This study does not support existing lay reports of ocular and dermatologic disease in humans and animals that had been associated with the ozone hole over southern Chile. PMID:7702120

  11. Regulation of keratin expression by ultraviolet radiation: differential and specific effects of ultraviolet B and ultraviolet a exposure.

    PubMed

    Bernerd, F; Del Bino, S; Asselineau, D

    2001-12-01

    Skin, the most superficial tissue of our body, is the first target of environmental stimuli, among which is solar ultraviolet radiation. Very little is known about the regulation of keratin gene expression by ultraviolet radiation, however, although (i) it is well established that ultraviolet exposure is involved in skin cancers and photoaging and (ii) keratins represent the major epidermal proteins. The aim of this study was to analyze the regulation of human keratin gene expression under ultraviolet B (290-320 nm) or ultraviolet A (320-400 nm) irradiation using a panel of constructs comprising different human keratin promoters cloned upstream of a chloramphenicol acetyl transferase reporter gene and transfected into normal epidermal keratinocytes. By this approach, we demonstrated that ultraviolet B upregulated the transcription of keratin 19 gene and to a lesser extent the keratin 6, keratin 5, and keratin 14 genes. The DNA sequence responsible for keratin 19 induction was localized between -130 and +1. In contrast to ultraviolet B, ultraviolet A irradiation induced only an increase in keratin 17, showing a differential gene regulation between these two ultraviolet ranges. The induction of keratin 19 was confirmed by studying the endogenous protein in keratinocytes in classical cultures as well as in skin reconstructed in vitro and normal human skin. These data show for the first time that keratin gene expression is regulated by ultraviolet radiation at the transcriptional level with a specificity regarding the ultraviolet domain of solar light. PMID:11886503

  12. Chromosomal changes in cultured human epithelial cells transformed by low- and high-let radiation

    NASA Astrophysics Data System (ADS)

    Chui-Hsu Yang, Tracy; Craise, Laurie M.; Prioleau, John C.; Stampfer, Martha R.; Rhim, Johng S.

    1992-07-01

    For a better assessment of radiation risk in space, an understanding of the responses of human cells, especially the epithelial cells, to low- and high-LET radiation is essential. In our laboratory, we have successfully developed techniques to study the neoplastic transformation of two human epithelial cell systems by ionizing radiation. These cell systems are human mammary epithelial cells (H184B5) and human epidermal keratinocytes (HEK). Both cell lines are immortal, anchorage dependent for growth, and nontumorigenic in athymic nude mice. Neoplastic transformation was achieved by irradiating cells successively. Our results showed that radiogenic cell transformation is a multistep process and that a single exposure of ionizing radiation can cause only one step of transformation. It requires, therefore, multihits to make human epithelial cells fully tumorigenic. Using a simple karyotyping method, we did chromosome analysis with cells cloned at various stages of transformation. We found no consistent large terminal deletion of chromosomes in radiation-induced transformants. Some changes of total number of chromosomes, however, were observed in the transformed cells. These transformants provide an unique opportunity for further genetic studies at a molecular level.

  13. Overview on association of different types of leukemias with radiation exposure.

    PubMed

    Gluzman, D F; Sklyarenko, L M; Zavelevich, M P; Koval, S V; Ivanivska, T S; Rodionova, N K

    2015-06-01

    Exposure to ionizing radiation is associated with increasing risk of various types of hematological malignancies. The results of major studies on association of leukemias and radiation exposure of large populations in Japan and in Ukraine are analyzed. The patterns of different types of leukemia in 295 Chernobyl clean-up workers diagnosed according to the criteria of up-to-date World Health Organization classification within 10-25 years following Chernobyl catastrophe are summarized. In fact, a broad spectrum of radiation-related hematological malignancies has been revealed both in Life Span Study in Japan and in study of Chernobyl clean-up workers in Ukraine. The importance of the precise diagnosis of tumors of hematopoietic and lymphoid tissues according to up-to-date classifications for elucidating the role of radiation as a causative factor of leukemias is emphasized. Such studies are of high importance since according to the recent findings, radiation-associated excess risks of several types of leukemias seem to persist throughout the follow-up period up to 55 years after the radiation exposure. PMID:26112933

  14. Human Rights Engagement and Exposure: New Scales to Challenge Social Work Education

    ERIC Educational Resources Information Center

    McPherson, Jane; Abell, Neil

    2012-01-01

    Objectives: Advancing human rights is a core competency of U.S. social work education; yet, human rights attitudes and behaviors have never been measured in the social work literature. Thus, this article describes the development and initial validation of two scales, Human Rights Engagement in Social Work (HRESW) and Human Rights Exposure in…

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

    Cancer.gov

    The initial dose calculator for I-131 fallout from the Nevada Test Site was developed, designed, and programmed by Jed Rifkin, PhD, and Andre Bouville, PhD, of the National Cancer Institute, National Institutes of Health, Department of Health and Human Services.

  16. Effects of Radiation Exposure From Cardiac Imaging: How Good Are the Data?

    PubMed Central

    Einstein, Andrew J.

    2012-01-01

    Concerns about medical exposure to ionizing radiation have become heightened in recent years due to rapid growth in procedure volumes and the high radiation doses incurred from some procedures. This article summarizes the evidence base undergirding concerns about radiation exposure in cardiac imaging. After classifying radiation effects, explaining terminology used to quantify the radiation received by patients, and describing typical doses from cardiac imaging procedures, I address the major epidemiological studies having bearing on radiation effects at doses comparable to those received by patients undergoing cardiac imaging. These include studies of atomic bomb survivors, nuclear industry workers, and children exposed in utero to x-rays, all of which have evidenced increased cancer risks at low doses. Additional higher dose epidemiological studies of cohorts exposed to radiation in the context of medical treatment are described and found to be generally compatible with these cardiac-dose-level studies, albeit with exceptions. Using risk projection models developed by the US National Academies that incorporate these data and reflect several evidence-based assumptions, cancer risk from cardiac imaging can be estimated and compared to benefits from imaging. Several ongoing epidemiological studies will provide better understanding of radiation-associated cancer risks. PMID:22300689

  17. Modeling community asbestos exposure near a vermiculite processing facility: Impact of human activities on cumulative exposure.

    PubMed

    Adgate, John L; Cho, Sook Ja; Alexander, Bruce H; Ramachandran, Gurmurthy; Raleigh, Katherine K; Johnson, Jean; Messing, Rita B; Williams, A L; Kelly, James; Pratt, Gregory C

    2011-01-01

    Contaminated vermiculite ore from Libby, Montana was processed in northeast Minneapolis from 1936 to 1989 in a densely populated urban residential neighborhood, resulting in non-occupational exposure scenarios from plant stack and fugitive emissions as well as from activity-based scenarios associated with use of the waste rock in the surrounding community. The objective of this analysis was to estimate potential cumulative asbestos exposure for all non-occupationally exposed members of this community. Questionnaire data from a neighborhood-exposure assessment ascertained frequency of potential contact with vermiculite processing waste. Monte Carlo simulation was used to develop exposure estimates based on activity-based concentration estimates and contact durations for four scenarios: S1, moved asbestos-contaminated waste; S2, used waste at home, on lawn or garden; S3, installed/removed vermiculite insulation; S4, played in or around waste piles at the plant. The simulation outputs were combined with air-dispersion model results to provide total cumulative asbestos exposure estimates for the cohort. Fiber emissions from the plant were the largest source of exposure for the majority of the cohort, with geometric mean cumulative exposures of 0.02 fibers/cc × month. The addition of S1, S2 and S3 did not significantly increase total cumulative exposure above background exposure estimates obtained from dispersion modeling. Activity-based exposures were a substantial contributor to the upper end of the exposure distribution: 90th percentile S4 exposure estimates are ?10 times higher than exposures from plant emissions. Pile playing is the strongest source of asbestos exposure in this cohort, with other activity scenarios contributing less than from plant emissions. PMID:21343955

  18. Leukocyte activity is altered in a ground based murine model of microgravity and proton radiation exposure.

    PubMed

    Sanzari, Jenine K; Romero-Weaver, Ana L; James, Gabrielle; Krigsfeld, Gabriel; Lin, Liyong; Diffenderfer, Eric S; Kennedy, Ann R

    2013-01-01

    Immune system adaptation during spaceflight is a concern in space medicine. Decreased circulating leukocytes observed during and after space flight infer suppressed immune responses and susceptibility to infection. The microgravity aspect of the space environment has been simulated on Earth to study adverse biological effects in astronauts. In this report, the hindlimb unloading (HU) model was employed to investigate the combined effects of solar particle event-like proton radiation and simulated microgravity on immune cell parameters including lymphocyte subtype populations and activity. Lymphocytes are a type of white blood cell critical for adaptive immune responses and T lymphocytes are regulators of cell-mediated immunity, controlling the entire immune response. Mice were suspended prior to and after proton radiation exposure (2 Gy dose) and total leukocyte numbers and splenic lymphocyte functionality were evaluated on days 4 or 21 after combined HU and radiation exposure. Total white blood cell (WBC), lymphocyte, neutrophil, and monocyte counts are reduced by approximately 65%, 70%, 55%, and 70%, respectively, compared to the non-treated control group at 4 days after combined exposure. Splenic lymphocyte subpopulations are altered at both time points investigated. At 21 days post-exposure to combined HU and proton radiation, T cell activation and proliferation were assessed in isolated lymphocytes. Cell surface expression of the Early Activation Marker, CD69, is decreased by 30% in the combined treatment group, compared to the non-treated control group and cell proliferation was suppressed by approximately 50%, compared to the non-treated control group. These findings reveal that the combined stressors (HU and proton radiation exposure) result in decreased leukocyte numbers and function, which could contribute to immune system dysfunction in crew members. This investigation is one of the first to report on combined proton radiation and simulated microgravity effects on hematopoietic, specifically immune cells. PMID:23977138

  19. Diagnostic Ionizing Radiation Exposure in a Population-based Sample of Children with Inflammatory Bowel Diseases

    PubMed Central

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

    2009-01-01

    Background and Aims The degree of diagnostic radiation exposure in children with inflammatory bowel diseases (IBD) is largely unknown. Here we describe this exposure in a population-based sample of children with IBD and determine characteristics associated with moderate radiation exposure. Methods We ascertained radiological study use, demographic characteristics, IBD medication use, and the requirement for hospitalization, emergency department (ED) encounter, or inpatient GI surgery among children with IBD within a large insurance claims database. Characteristics associated with moderate radiation exposure (at least one computed tomography (CT) or three fluoroscopies over two years) were determined using logistic regression models. Results We identified 965 children with Crohn’s Disease (CD) and 628 with Ulcerative Colitis (UC). Over 24 months, 34% of CD subjects and 23% of UC subjects were exposed to moderate diagnostic radiation [odds ratio (OR) 1.71, 95% confidence interval (CI), 1.36–2.14]. CT accounted for 28% and 25% of all studies in CD and UC subjects, respectively. For CD subjects, moderate radiation exposure was associated with hospitalization (OR 4.89, 95% CI 3.37–7.09), surgery (OR 2.93, 95% CI 1.59–5.39), ED encounter (OR 2.65, 1.93–3.64 95% CI), oral steroids (OR 2.25, 95% CI 1.50–3.38), and budesonide (OR 1.80, 95% CI 1.10–3.06); an inverse association was seen with immunomodulator use (OR 0.67, 95% CI 0.47–0.97). Except for oral steroids and immunomodulators, similar relationships were seen in UC. Conclusion A substantial proportion of children with IBD are exposed to moderate amounts of radiation as a result of diagnostic testing. This high utilization may impart long-term risk given the chronic nature of the disease. PMID:19690524

  20. Leukocyte Activity Is Altered in a Ground Based Murine Model of Microgravity and Proton Radiation Exposure

    PubMed Central

    Sanzari, Jenine K.; Romero-Weaver, Ana L.; James, Gabrielle; Krigsfeld, Gabriel; Lin, Liyong; Diffenderfer, Eric S.; Kennedy, Ann R.

    2013-01-01

    Immune system adaptation during spaceflight is a concern in space medicine. Decreased circulating leukocytes observed during and after space flight infer suppressed immune responses and susceptibility to infection. The microgravity aspect of the space environment has been simulated on Earth to study adverse biological effects in astronauts. In this report, the hindlimb unloading (HU) model was employed to investigate the combined effects of solar particle event-like proton radiation and simulated microgravity on immune cell parameters including lymphocyte subtype populations and activity. Lymphocytes are a type of white blood cell critical for adaptive immune responses and T lymphocytes are regulators of cell-mediated immunity, controlling the entire immune response. Mice were suspended prior to and after proton radiation exposure (2 Gy dose) and total leukocyte numbers and splenic lymphocyte functionality were evaluated on days 4 or 21 after combined HU and radiation exposure. Total white blood cell (WBC), lymphocyte, neutrophil, and monocyte counts are reduced by approximately 65%, 70%, 55%, and 70%, respectively, compared to the non-treated control group at 4 days after combined exposure. Splenic lymphocyte subpopulations are altered at both time points investigated. At 21 days post-exposure to combined HU and proton radiation, T cell activation and proliferation were assessed in isolated lymphocytes. Cell surface expression of the Early Activation Marker, CD69, is decreased by 30% in the combined treatment group, compared to the non-treated control group and cell proliferation was suppressed by approximately 50%, compared to the non-treated control group. These findings reveal that the combined stressors (HU and proton radiation exposure) result in decreased leukocyte numbers and function, which could contribute to immune system dysfunction in crew members. This investigation is one of the first to report on combined proton radiation and simulated microgravity effects on hematopoietic, specifically immune cells. PMID:23977138

  1. Comparison of operator radiation exposure with optimized radiation protection devices during coronary angiograms and ad hoc percutaneous coronary interventions by radial and femoral routes

    Microsoft Academic Search

    Camille Brasselet; Thierry Blanpain; Sophie Tassan-Mangina; Alain Deschildre; Sebastien Duval; Fabien Vitry; Nathalie Gaillot-Petit; Jean Paul Clement; Damien Metz

    During 420 consecutive coronary angiograms (CAs) and percutaneous coronary interventions (PCIs), four interven- tional cardiologists were blindly screened. Radiation exposures were assessed using electronic personal dosimeters. Protection of operator was ensured using a lead apron, low leaded flaps, and leaded glass. Radiation exposure of operators was significantly higher using the radial route when compared with the femoral route for both

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

    PubMed

    Martin, Lynn M; Marples, Brian; Lynch, Thomas H; Hollywood, Donal; Marignol, Laure

    2014-07-10

    This review article provides a comprehensive overview of the experimental data detailing the incidence, mechanism and significance of low dose hyper-radiosensitivity (HRS). Important discoveries gained from past and present studies are mapped and highlighted to illustrate the pathway to our current understanding of HRS and the impact of HRS on the cellular response to radiation in mammalian cells. Particular attention is paid to the balance of evidence suggesting a role for DNA repair processes in the response, evidence suggesting a role for the cell cycle checkpoint processes, and evidence investigating the clinical implications/relevance of the effect. PMID:24983100

  3. [The need to account for beta radiation in determining the total radiation exposure of those working in cleanup].

    PubMed

    Osanov, D P; Kriuchkov, V P

    1996-01-01

    The role of external beta-radiation as one of the major radiation factors effected persons involved in recovery operations (liquidators) after the accident at the Chernobyl nuclear power plant is considered. The paper uses the data of discriminate individual dosimetric monitoring of beta- and gamma-radiation for different groups of liquidators and experimentally received dose distribution in tissue equivalent material in the places of carrying out work. The results obtained by calculation were also used. It was established that experimentally determined ratios of beta-radiation doses to gamma-radiation doses have a good correlation with estimates resulted by calculation. It allowed the authors to use these estimates and individual gamma-radiation dose distribution for drawing histograms of individual beta-radiation dose distribution for open parts of skin, for lens, and gonads in cases of liquidators involved in building "sarcophagus". The obtained estimates of individual doses in the near surface tissue and organs exceeds significantly exposure levels for the whole body. This fact should draw the special attention to the rise in the number of radiation-induced cancer and cataracts. PMID:8925036

  4. Summary of ionizing radiation analysis on the Long Duration Exposure Facility

    NASA Technical Reports Server (NTRS)

    Parnell, T. A.

    1992-01-01

    The ionizing radiation measurements flown on the Long Duration Exposure Facility (LDEF) were contained in 15 experiments which utilized passive detectors to pursue objectives in astrophysics and to measure the radiation environment and dosimetric quantities. The spacecraft structure became sufficiently radioactive to permit additional important studies. The induced activity allows extensive radiation mapping in the structure, and independent comparison with experiment dosimetric techniques, and significant studies of secondary effects. The long exposure time, attitude stability, and number and types of measurements produced a unique and critical set of data for low Earth orbit that will not be duplicated for more than a decade. The data allow an unprecedented test, and improvement if required, of models of the radiation environment and the radiation transport methods that are used to calculate the internal radiation and its effects in spacecraft. Results of measurements in the experiments, as well as from radioactivity in the structure, have clearly shown effects from the directional properties of the radiation environment, and progress was made in the dosimetric mapping of LDEF. These measurements have already influenced some Space Station Freedom design requirements. Preliminary results from experiments, reported at this symposium and in earlier papers, show that the 5.8 years exposure considerably enhanced the scientific return of the radiation measurements. The early results give confidence that the experiments will make significant advances in the knowledge of ultra heavy cosmic rays, anomalous cosmic rays, and heavy ions trapped in the radiation belts. Unexpected phenomena were observed, which require explanation. These include stopping iron group ions between the energy ranges anticipated for anomalous and galactic cosmic rays in the LDEF orbit. A surprising concentration of the Be-7 nuclide was discovered on the 'front' surface of LDEF, apparently transported up from the stratosphere with exceptional efficiency.

  5. Processing of thermoset prepreg laminate via exposure to microwave radiation

    SciTech Connect

    Paulauskas, F.L. [Oak Ridge National Lab., TN (United States); Meek, T.T. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering

    1994-06-01

    Studies of microwave-assisted curing of neat resins (epoxy) and unidirectional glass and carbon fiber laminates have shown that a substantial reduction in the curing time was obtained. This may be explained by the penetration of microwave energy directly and throughout the laminate with enhancement of the kinetics of the chemical reaction. Results of this work indicate that the microwave assisted curing of glass fiber laminates also shows a substantial reduction of the required curing time. Microwave radiation of 2.45 GHz has been demonstrated to be an acceptable method to cure unidirectional carbon fiber laminates. Also, effective curing of crossply (0/90) laminates through this method was observed when proper rotation of the parts accompanied the curing process. This is in accordance with previous work. Multidirectional carbon fiber/epoxy laminates demonstrate a lack of coupling during the curing process. A direct curing of these laminates was not possible by microwave radiation with the experimental approach used, in agreement with previous work. Nevertheless, a moderate reduction in the curing time of these thin laminates was observed due to hybrid curing.

  6. Radiation exposure predictions for long-duration-stay Mars missions

    SciTech Connect

    Striepe, S.A.; Simonsen, L.C.; Nealy, J.E.

    1994-04-01

    In this study, the ionizing radiation environment is estimated, using the Mission Radiation Calculation (MIRACAL) program, for several long-duration-stay Mars missions proposed for early in the 21(sup st) century. Both minimum energy and fast transfer missions are evaluated and their 30-day maximum, annual maximum, and total slab skin and blood-forming organ (BFO) doses are compared. When large flares were included while the astronauts were on the surface, the delivered dose did not significantly contribute to the total dose (less than 4 cSv BFO dose, or 8 percent of the guideline annual limit, for the most energetic event simulated) due to the substantial protection provided by the Martian atmosphere. However, dose delivered by large flares during transit is dependent on vehicle shielding and distance from the Sun. All of the fast transfer missions studied had lower total and annual maximum doses than the corresponding minimum energy transfer missions (on average, 30% less for missions having no large flares and the shielding thicknesses evaluated in this study). For all the missions studied, having the astronauts spend one-third of their day during transit in a 10 g/sq cm storm shelter resulted in an approximate 10% reduction in the total mission dose. 18 refs.

  7. Radiation exposure predictions for long-duration-stay Mars missions

    NASA Technical Reports Server (NTRS)

    Striepe, Scott A.; Simonsen, Lisa C.; Nealy, John E.

    1994-01-01

    In this study, the ionizing radiation environment is estimated, using the Mission Radiation Calculation (MIRACAL) program, for several long-duration-stay Mars missions proposed for early in the 21(sup st) century. Both minimum energy and fast transfer missions are evaluated and their 30-day maximum, annual maximum, and total slab skin and blood-forming organ (BFO) doses are compared. When large flares were included while the astronauts were on the surface, the delivered dose did not significantly contribute to the total dose (less than 4 cSv BFO dose, or 8 percent of the guideline annual limit, for the most energetic event simulated) due to the substantial protection provided by the Martian atmosphere. However, dose delivered by large flares during transit is dependent on vehicle shielding and distance from the Sun. All of the fast transfer missions studied had lower total and annual maximum doses than the corresponding minimum energy transfer missions (on average, 30% less for missions having no large flares and the shielding thicknesses evaluated in this study). For all the missions studied, having the astronauts spend one-third of their day during transit in a 10 g/sq cm storm shelter resulted in an approximate 10% reduction in the total mission dose.

  8. Radiation exposure predictions for long-duration-stay Mars missions

    NASA Technical Reports Server (NTRS)

    Striepe, Scott A.; Simonsen, Lisa C.; Nealy, John E.

    1992-01-01

    In this study, the ionizing radiation environment is estimated, using the Mission Radiation Calculation (MIRACAL) program, for several long-duration-stay Mars missions proposed for early in the 21st century. Both long-fast and minimum energy transfer missions are evaluated, and their 30-day maximum, annual maximum, and total slab skin and blood-forming organ (BFO) doses are compared. When large flares were included while the astronauts were on the surface, the delivered dose did not significantly contribute to the total dose (less than 4 cSv BFO dose, or 8 percent of the guideline annual limit, for the most energetic event simulated) due to the substantial protection provided by the Martian atmosphere. However, dose delivered by large flares during transit is dependent on vehicle shielding and distance from the sun. All of the long-fast transfer missions studied had lower total and annual maximum doses than the corresponding minimum energy transfer missions (on average, 30 percent less for missions having no large flares and the shielding thicknesses evaluated in this study). For all the missions studied, having the astronauts spend one-third of their day during transit in a 10 g/sq cm storm shelter resulted in significantly lower total doses.

  9. Life span of C57 mice as influenced by radiation dose, dose rate, and age at exposure

    SciTech Connect

    Spalding, J.F.; Thomas, R.G.; Tietjen, G.L.

    1982-10-01

    This study was designed to measure the life shortening of C57BL/6J male mice as a result of exposure to five external doses from /sup 60/Co gamma radiation delivered at six different dose rates. Total doses ranged from 20 to 1620 rad at exposure rates ranging from 0.7 to 36,000 R/day. The ages of the mice at exposure were newborn, 2, 6, or 15 months. Two replications were completed. Although death was the primary endpoint, we did perform gross necropsies. The life span findings are variable, but we found no consistent shortening compared to control life spans. Therefore, we cannot logically extrapolate life shortening to lower doses, from the data we have obtained. In general, the younger the animals were at the beginning of exposure, the longer their life spans were compared to those of controls. This relationship weakened at the higher doses and dose rates, as mice in these categories tended not to have significantly different life spans from controls. Using life span as a criterion, we find this study suggests that some threshold dosage may exist beyond which effects of external irradiation may be manifested. Up to this threshold, there is no shortening effect on life span compared to that of control mice. Our results are in general agreement with the results of other researchers investigating human and other animal life span effects on irradiation.

  10. The role of cellular and molecular studies in evaluation of health effects from combined radiation and chemical exposures

    SciTech Connect

    Brooks, A.L.; Gilbert, E.S. (Pacific Northwest Lab., Richland, WA (United States)); Kitchin, R.M. (Wyoming Univ., Laramie, WY (United States)); Johnson, N.F. (Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States). Inhalation Toxicology Research Inst.)

    1992-06-01

    Additive models are currently used to predict risks following exposure to multiple agents or complex mixtures. Use of these models is questioned because different methods are used to derive risks for chemical and physical agents depending on the database used. Risks for the induction of cancer from radiation are based on large sets of human data, while standards are set for most chemical carcinogens using information derived from animal studies. However, it is not, from a scientific point of view, appropriate to add risks from physical and chemical agents to derive potential health impact from combined exposures. The range of safety factors built into the estimates, the large differences in the data sets used to evaluate and establish standards, and the differences in the basic philosophy for deriving risks for physical and chemical agents make the additive model unacceptable for estimating risks from combined exposures. To understand the potential health impacts from environmental exposure, it is important (1) to consider how risks were derived and (2) to determine if interactions exist between damage induced by the different agents to ensure that additive assumptions are valid. This presentation discusses a number of these safety factors for specific chemicals.

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

    SciTech Connect

    Frohmberg, E.; Goble, R.; Sanchez, V.; Quigley, D.

    2000-02-01

    Native Americans residing in a broad region downwind from the Nevada Test Site during the 1950s and 1960s received significant radiation exposures from nuclear weapons testing. Because of differences in diet, activities, and housing, their radiation exposures are only very imperfectly represented in the Department of Energy dose reconstructions. There are important missing pathways, including exposures to radioactive iodine from eating small game. The dose reconstruction model assumptions about cattle feeding practices across a year are unlikely to apply to the native communities as are other model assumptions about diet. Thus exposures from drinking milk and eating vegetables have not yet been properly estimated for these communities. Through consultations with members of the affected communities, these deficiencies could be corrected and the dose reconstruction extended to Native Americans. An illustration of the feasibility of extending the dose reconstruction is provided by a sample calculation to estimate radiation exposures to the thyroid from eating radio-iodine-contaminated rabbit thyroids after the Dedan test. The illustration is continued with a discussion of how the calculation results may be used to make estimates for other tests and other locations.

  12. The assessment of radiation exposures in Native American communities from nuclear weapons testing in Nevada.

    PubMed

    Frohmberg, E; Goble, R; Sanchez, V; Quigley, D

    2000-02-01

    Native Americans residing in a broad region downwind from the Nevada Test Site during the 1950s and 1960s received significant radiation exposures from nuclear weapons testing. Because of differences in diet, activities, and housing, their radiation exposures are only very imperfectly represented in the Department of Energy dose reconstructions. There are important missing pathways, including exposures to radioactive iodine from eating small game. The dose reconstruction model assumptions about cattle feeding practices across a year are unlikely to apply to the native communities as are other model assumptions about diet. Thus exposures from drinking milk and eating vegetables have not yet been properly estimated for these communities. Through consultations with members of the affected communities, these deficiencies could be corrected and the dose reconstruction extended to Native Americans. An illustration of the feasibility of extending the dose reconstruction is provided by a sample calculation to estimate radiation exposures to the thyroid from eating radio-iodine-contaminated rabbit thyroids after the Sedan test. The illustration is continued with a discussion of how the calculation results may be used to make estimates for other tests and other locations. PMID:10795343

  13. Radiation effects in concrete for nuclear power plants Part I: Quantification of radiation exposure and radiation effects

    SciTech Connect

    Field, Kevin G [ORNL; Pape, Yann Le [Oak Ridge National Laboratory (ORNL); Remec, Igor [ORNL

    2015-01-01

    A large fraction of light water reactor (LWR) construction utilizes concrete, including safety-related structures such as the biological shielding and containment building. Concrete is an inherently complex material, with the properties of concrete structures changing over their lifetime due to the intrinsic nature of concrete and influences from local environment. As concrete structures within LWRs age, the total neutron fluence exposure of the components, in particular the biological shield, can increase to levels where deleterious effects are introduced as a result of neutron irradiation. This work summarizes the current state of the art on irradiated concrete, including a review of the current literature and estimates the total neutron fluence expected in biological shields in typical LWR configurations. It was found a first-order mechanism for loss of mechanical properties of irradiated concrete is due to radiation-induced swelling of aggregates, which leads to volumetric expansion of the concrete. This phenomena is estimated to occur near the end of life of biological shield components in LWRs based on calculations of estimated peak neutron fluence in the shield after 80 years of operation.

  14. Structural evolution and degradation mechanism of Vectran upon exposure to UV-radiation

    E-print Network

    Guo, John Zhanhu

    Structural evolution and degradation mechanism of VectranÒ fibers upon exposure to UV-radiation to ultraviolet (UV) irradiation in service. The focus of this work is to investigate the photochemical aging and behaviors against UV irradiation have been studied. The tensile test results reveal that the tensile

  15. Superior orbital 'petrositis' and late ischaemic monocular blindness induced by intense UV radiation exposure

    Microsoft Academic Search

    C. A. A. Penatti; M. L. Monteiro; P. E. Marchiori; M. Scaff

    2002-01-01

    Many physical agents cause neuropathies. The most common are chronic pressure, vibration and temperature. In general, these lesions occur at work, as a result of accidents or through chronic exposure to the physical agent. Radiation leading to peripheral neuropathy is also related to radiotherapy in cancer treatment, as an undesirable side-effect. We present here a case report of short, intense

  16. Childhood exposure to ultraviolet radiation and harmful skin effects: Epidemiological evidence

    Microsoft Academic Search

    Adèle C. Green; Sarah C. Wallingford; Penelope McBride

    We review the general amount and patterns of exposure to solar ultraviolet (UV) radiation that children and teenagers experience and the spectrum of UV-related skin damage that can occur as a result. Data about the amount of solar UV received by children and teenagers are relatively few but suggest that around 40–50% of total UV to age 60 occurs before

  17. CHRONIC EXPOSURE OF RATS TO 100-MHZ (CW) RADIOFREQUENCY RADIATION: ASSESSMENT OF BIOLOGICAL EFFECTS

    EPA Science Inventory

    A multidisciplinary approach was employed to assess the possible biological effects of chronic exposure of rats to 100-MHz continuous wave (CW) radiofrequency (RF) radiation. A group of 20 time-bred rats were exposed in a transverse electronmagnetic mode (TEM) transmission line t...

  18. Analyses of risks associated with radiation exposure from past major solar particle events

    Microsoft Academic Search

    Mark D. Weyland; William Atwell; Francis A. Cucinotta; John W. Wilson; Alva C. Hardy

    1991-01-01

    Radiation exposures and cancer induction\\/mortality risks were investigated for several major solar particle events (SPE's). The SPE's included are: February 1956, November 1960, August 1972, October 1989, and the September, August, and October 1989 events combined. The three 1989 events were treated as one since all three could affect a single lunar or Mars mission. A baryon transport code was

  19. Ultraviolet Radiation Exposure of Children and Adolescents in Durban, South Africa¶

    Microsoft Academic Search

    Caradee Guy; Roseanne Diab; Bice Martincigh

    2003-01-01

    This paper presents the findings of an initial investigation into the daily ultraviolet radiation (UV) exposure patterns and erythemal UV doses of thirty children and adolescents in Durban for one week during school term in summer. Polysulphone film badges were used to quantify individual erythemal UV dose and each subject recorded their daily activities in a journals. The mean daily

  20. BYSTANDER EFFECTS, GENOMIC INSTABILITY, ADAPTIVE RESPONSE AND CANCER RISK ASSESSMENT FOR RADIATION AND CHEMICAL EXPOSURES

    EPA Science Inventory

    There is an increased interest in utilizing mechanistic data in support of the cancer risk assessment process for ionizing radiation and environmental chemical exposures. In this regard the use of biologically based dose-response models is particularly advocated. The aim is to pr...