DOCSLIB.ORG

Radiation Hormesis, Or, Could All That Radiation Be Good for Us?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Radiation Hormesis, Or, Could All That Radiation Be Good for Us? SPECIAL CONTRIBUTIONS Radiation Hormesis, or, Could All That Radiation Be Good for Us? Jennifer L. Prekeges, MS, CNMT Virginia Mason Medical Center, Seattle, Washington emerge from the information presented here: that public Objective: Nuclear medicine technologists work under sig- perception drives the enactment of regulation as much as nificant radiation protection constraints. These constraints does science and that, although the science of radiation are based on the linear no-threshold (LNT) radiation para- biology has advanced, regulations affecting occupational digm, which was developed in the 1960s and was based radiation exposure have not. largely on the deleterious effects of radiation as they were understood at the time. More recently, the theory of radia- tion hormesis, or a beneficial effect of low-level exposure to HISTORY OF PERCEPTIONS ABOUT RADIATION radiation, has gained recognition. This article reviews the Radiation has always been present in our environment. history of attitudes toward radiation, describes the radiation hormesis hypothesis, examines some of the evidence that However, mankind was not directly aware of its existence supports it, and suggests ways that radiation protection until the end of the 19th century, when a flurry of scientific regulations might change if the hypothesis were to become discoveries were made. In 1895, Wilhelm Roentgen discov- accepted. ered x-rays. In 1896, Henri Becquerel discovered the spon- Key Words: radiation hormesis; radiobiology; effects of ra- taneous emission of radiation from uranium, a phenomenon diation he called “radioactivity.” And, in 1898, Marie Curie dis- J Nucl Med Technol 2003; 31:11–17 covered radium, which is luminescent as well as having radioactive isotopes (1). Beyond the revolution they caused in basic physics, these discoveries were put to immediate practical use. The first Nuclear medicine is governed by regulations that are diagnostic x-ray was produced in January 1896, only a few based on an understanding of the harmful effects of radia- months after Roentgen made his discovery. More than 1,000 tion that was current in the early 1960s. However, the articles on x-rays were published that year. The field of question of whether low levels of radiation can cause harm nuclear medicine had its origins in 1923, when Georg de remains controversial. Several recent studies suggest that Hevesy proposed using radioactive tracers in biomedical radiation exposure, under some circumstances, can be ben- research. Today, the field of diagnostic radiology with its eficial. This new theory of radiation hormesis is especially various modalities affects the great majority of people in the pertinent to nuclear medicine technologists, who are ex- developed world. posed in the low-dose, low dose-rate fashion that seems to But the new rays were put to use in more mundane tools carry beneficial effects. as well (2). Thomas Edison introduced a home fluoroscopy This article will introduce radiation hormesis to the nu- unit in 1896. In the 1920s, x-ray units were used in beauty clear medicine technologist community by first reviewing parlors to remove unwanted facial and body hair. Even into the history of our perceptions of radiation and then contrast- the 1950s, fluoroscopes were used to measure the fit of ing the current radiation paradigm with a radiation hormesis children’s shoes. paradigm. Epidemiological and experimental evidence sup- The ability of radiation to treat disease was also explored porting the radiation hormesis paradigm will be reviewed. soon after its discovery. The first recorded radiation treat- Finally, several ways will be suggested in which the practice ment was performed in 1896. Radiation’s benefits for treat- of nuclear medicine and the utilization of radioactive ma- ment of malignancy are well documented and widely used. terials in general might be made easier by the acceptance of More recently, the use of radionuclides to treat certain the radiation hormesis hypothesis. Two specific points will illnesses, both malignant and nonmalignant, has become established. Radiation also has been used at various times to treat several nonmalignant conditions, including ankylosing For correspondence or reprints contact: Jennifer L. Prekeges, MS, spondylitis, postpartum breast tenderness, and scalp ring- CNMT, Nuclear Medicine, C5-NM, Virginia Mason Medical Center, P.O. Box 900, Seattle, WA 98111-0900. worm (3). It was even used for a brief period in efforts to E-mail address: [email protected] increase fertility (3). These uses have been discontinued. VOLUME 31, NUMBER 1, MARCH 2003 11 Various forms of radium were put to more esoteric uses (2). The Radium Eclipse Sprayer purported to be a combi- nation insecticide and furniture polish. Radithor tonic con- tained 0.076 MBq (2 ␮Ci) radium per bottle and was touted for its health benefits. Radium-containing beverages were called “liquid sunshine cocktails.” One could even play “radium roulette” (the wheel, balls, and chips were painted with radium) or purchase a glowing radium-painted cruci- fix. Radium also produced some of the early harmful conse- quences of radiation. In the 1920s, women who painted watch dials with radium were diagnosed with osteosarco- mas and osteonecrosis. Even before that, radiation injuries had been reported. Becquerel left a vial of radioactive FIGURE 1. Three hypotheses of radiation dose–response rela- material in his coat breast pocket, resulting in erythema and tionship, as proposed by the United Nations Scientific Committee skin ulceration, the first recorded radiation injury. The first on the Effects of Atomic Radiation in 1958. (Reprinted with permis- known casualty resulting from radiation exposure was Clar- sion of (3).) ence Dally, Thomas Edison’s assistant. Dally was involved in Edison’s early work with x-rays, all of which was per- formed without benefit of shielding. Dally’s death was to accept this model as the basis for recommendations for horrific: his flesh became ulcerated, his hair fell out in radiation exposure limits. Because it was presumed to afford clumps, and he underwent multiple amputations of both the greatest protection, the LNT hypothesis became the arms in an effort to stem the progression of radiation dam- basis of the accepted model, or paradigm, for radiation’s age. ability to cause harm. The event that truly caught the public’s attention, how- A paradigm is an interlocking set of assumptions about ever, was the dropping of 2 atomic bombs in World War II. the operation of a complex system (4). It is a model of how The combination of immediate devastation, acute radiation the system works. Once accepted by the scientific commu- injuries, and increased leukemia incidence among survivors nity, a paradigm tends to channel attention and research cemented in the general consciousness the idea that radia- funding into “acceptable” directions. Observations that fail tion is harmful. Further experiments, such as the Mega- to fit the paradigm may be ignored or suppressed. This is not mouse genetic work at Oak Ridge National Laboratory in a conspiracy but, instead, a reflection of human nature. the 1950s, added to our understanding of radiation’s risks. When we believe something to be true, we discount alter- More recent incidents, such as the Chernobyl explosion, native statements that contradict the “truth” as we perceive have only reinforced these perceptions. it. In general, a paradigm must be conclusively disproved In the same time frame, scientific experiments using before a new paradigm can be accepted. tissue culture illuminated the effects of radiation on a cel- The LNT hypothesis assumes that the passage of a single lular level. Irradiation of cells was found to cause DNA charged particle through a single cell could cause damage to damage, division delay (longer than normal time to the next DNA that could lead to a genetic defect or a cancer. Thus division cycle), reproductive failure (inability to maintain the radiation paradigm based on the LNT hypothesis has the cell division over a long period of time), and interphase following tenets: death (cell death before the next cell cycle). These experi- ● Radiation exposure is harmful; ments solidified the understanding (widely held at that time) ● Radiation exposure is harmful at all exposure levels; that radiation is harmful. ● Each increment of exposure adds to the overall risk; and TWO RADIATION PARADIGMS ● The rate of accumulation of radiation exposure has no bearing on risk. The bureaucratic response to this knowledge of radia- tion’s dangers was embodied in the linear no-threshold These tenets reflect the mechanistic assumption that each (LNT) hypothesis. The United Nations Scientific Commit- particle of ionizing radiation (␣, ␤,or␥) can cause a DNA tee on the Effects of Atomic Radiation (UNSCEAR) in mutation, which, in turn, can potentially lead to a cancer. 1958 proposed 3 relationships of risk-versus-radiation dose Further, the proportional relationship of radiation expo- (Fig. 1). Of the 3 relationships, the linear model is the most sure to DNA damage to fatal illness allows the same prin- conservative, because it predicts the greatest amount of ciples to be applied on a population basis. The risk to a harm at low levels of radiation. In 1960, the International population in a radiation incident is directly proportional to Commission on Radiation Protection (ICRP) and its U.S. the aggregate radiation exposure of that population. This counterpart, the National Council on Radiation Protection implies that individually
Load more

Recommended publications
  • The Overestimation of Medical Consequences of Low-Dose Exposure to Ionizing Radiation
    The Overestimation of Medical Consequences of Low-Dose Exposure to Ionizing Radiation The Overestimation of Medical Consequences of Low-Dose Exposure to Ionizing Radiation By Sergei V. Jargin The Overestimation of Medical Consequences of Low-Dose Exposure to Ionizing Radiation By Sergei V. Jargin This book first published 2019 Cambridge Scholars Publishing Lady Stephenson Library, Newcastle upon Tyne, NE6 2PA, UK British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Copyright © 2019 by Sergei V. Jargin All rights for this book reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner. ISBN (10): 1-5275-2672-0 ISBN (13): 978-1-5275-2672-3 In memory of my father Vadim S. Yargin (1923-2012), co-author of the “Handbook of Physical Properties of Liquids and Gases” edited by Begell House. TABLE OF CONTENTS Introduction ................................................................................................ 1 Chapter One ................................................................................................ 3 Hormesis and Radiation Safety Norms Chapter Two ............................................................................................. 23 Dose and Dose Rate Effectiveness Factor (DDREF) Chapter Three ..........................................................................................
    [Show full text]
  • NUCLEAR ENERGY and HEALTH and the Benefits of Low-Dose Radiation Hormesis Jerry M Cuttler Cuttler & Associates Inc., Mississauga, ON, Canada
    Dose-Response: An International Journal Volume 7 | Issue 1 Article 3 3-2009 NUCLEAR ENERGY AND HEALTH And the Benefits of Low-Dose Radiation Hormesis Jerry M Cuttler Cuttler & Associates Inc., Mississauga, ON, Canada Myron Pollycove University of California San Francisco, San Francisco, CA Follow this and additional works at: https://scholarworks.umass.edu/dose_response Recommended Citation Cuttler, Jerry M and Pollycove, Myron (2009) "NUCLEAR ENERGY AND HEALTH And the Benefits of Low-Dose Radiation Hormesis," Dose-Response: An International Journal: Vol. 7 : Iss. 1 , Article 3. Available at: https://scholarworks.umass.edu/dose_response/vol7/iss1/3 This Article is brought to you for free and open access by ScholarWorks@UMass Amherst. It has been accepted for inclusion in Dose-Response: An International Journal by an authorized editor of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. Cuttler and Pollycove: Nuclear energy and health Dose-Response, 7:52–89, 2009 InternationalDOSE-RESPONSESociety Formerly Nonlinearity in Biology, Toxicology, and Medicine www.Dose-Response.org Copyright © 2009 University of Massachusetts ISSN: 1559-3258 DOI: 10.2203/dose-response.08-024.Cuttler NUCLEAR ENERGY AND HEALTH And the Benefits of Low-Dose Radiation Hormesis Jerry M. Cuttler ᮀ Cuttler & Associates Inc., Mississauga, ON, Canada Myron Pollycove ᮀ School of Medicine, University of California San Francisco, San Francisco, CA ᮀ Energy needs worldwide are expected to increase for the foreseeable future, but fuel supplies are limited. Nuclear reactors could supply much of the energy demand in a safe, sustainable manner were it not for fear of potential releases of radioactivity.
    [Show full text]
  • Overview of Biological, Epidemiological, and Clinical Evidence of Radiation Hormesis
    Review Overview of Biological, Epidemiological, and Clinical Evidence of Radiation Hormesis Yuta Shibamoto 1,* and Hironobu Nakamura 2,3 1 Department of Radiology, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan 2 Department of Radiology, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan; [email protected] 3 Department of Radiology, Saito Yukokai Hospital, Osaka 567-0085, Japan * Correspondence: [email protected]; Tel.: +81-52-853-8274 Received: 2 July 2018; Accepted: 9 August 2018; Published: 13 August 2018 Abstract: The effects of low-dose radiation are being increasingly investigated in biological, epidemiological, and clinical studies. Many recent studies have indicated the beneficial effects of low doses of radiation, whereas some studies have suggested harmful effects even at low doses. This review article introduces various studies reporting both the beneficial and harmful effects of low-dose radiation, with a critique on the extent to which respective studies are reliable. Epidemiological studies are inherently associated with large biases, and it should be evaluated whether the observed differences are due to radiation or other confounding factors. On the other hand, well-controlled laboratory studies may be more appropriate to evaluate the effects of low-dose radiation. Since the number of such laboratory studies is steadily increasing, it will be concluded in the near future whether low-dose radiation is harmful or beneficial and whether the linear-no-threshold (LNT) theory is appropriate. Many recent biological studies have suggested the induction of biopositive responses such as increases in immunity and antioxidants by low-dose radiation.
    [Show full text]
  • Cuttler – Risk Vs Hormesis
    Proceedings of the 25th Annual Conference of the Canadian Nuclear Society, Toronto, June 6-9, 2004 What Becomes of Nuclear Risk Assessment in Light of Radiation Hormesis? Jerry M. Cuttler Cuttler & Associates Inc. [email protected] Abstract – A nuclear probabilistic risk or safety assessment (PRA or PSA) is a scientific calculation that uses assumptions and models to determine the likelihood of plant or fuel repository failures and the corresponding releases of radioactivity. Estimated radiation doses to the surrounding population are linked inappropriately to risks of cancer death and congenital malformations. Even though PRAs use very pessimistic assumptions, they demonstrate that nuclear power plants and fuel repositories are very safe compared with the health risks of other generating options or other risks that people readily accept. Because of the frightening negative images and the exaggerated safety and health concerns that are communicated, many people judge nuclear risks to be unacceptable and do not favour nuclear plants. Large-scale tests and experience with nuclear accidents demonstrate that even severe accidents expose the public to only low doses of radiation, and a century of research has demonstrated that such exposures are beneficial to health. A scientific basis for this phenomenon now exists. PRAs are valuable tools for improving plant designs, but if nuclear power is to play a significant role in meeting future energy needs, we must communicate its many real benefits and dispel the negative images formed by unscientific extrapolations of harmful effects at high doses. 1. NUCLEAR RISK ASSESSMENT Nuclear engineers calculate the likelihood of all possible accidents at a nuclear power plant and the resulting probability that people nearby might be harmed by such accidents.
    [Show full text]
  • It's Time for a New Low-Dose-Radiation Risk Assessment Paradigm—One That Acknowledges Hormesis
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by ScholarWorks@UMass Amherst Dose-Response: An International Journal Volume 6 | Issue 4 Article 4 12-2008 IT’S TIME FOR A NEW LOW-DOSE- RADIATION RISK ASSESSMENT PARADIGM—ONE THAT ACKNOWLEDGES HORMESIS Bobby R Scott Lovelace Respiratory Research Institute, Albuquerque, NM Follow this and additional works at: https://scholarworks.umass.edu/dose_response Recommended Citation Scott, Bobby R (2008) "IT’S TIME FOR A NEW LOW-DOSE-RADIATION RISK ASSESSMENT PARADIGM—ONE THAT ACKNOWLEDGES HORMESIS," Dose-Response: An International Journal: Vol. 6 : Iss. 4 , Article 4. Available at: https://scholarworks.umass.edu/dose_response/vol6/iss4/4 This Article is brought to you for free and open access by ScholarWorks@UMass Amherst. It has been accepted for inclusion in Dose-Response: An International Journal by an authorized editor of ScholarWorks@UMass Amherst. For more information, please contact [email protected]. Scott: New low-dose-radiation risk assessment paradigm Dose-Response, 6:333–351, 2008 InternationalDOSE-RESPONSESociety Formerly Nonlinearity in Biology, Toxicology, and Medicine www.Dose-Response.org Copyright © 2007 University of Massachusetts ISSN: 1559-3258 DOI: 10.2203/dose-response.07-005.Scott IT’S TIME FOR A NEW LOW-DOSE-RADIATION RISK ASSESSMENT PARADIGM—ONE THAT ACKNOWLEDGES HORMESIS Bobby R. Scott, PhD h Lovelace Respiratory Research Institute h The current system of radiation protection for humans is based on the linear-no- threshold (LNT) risk-assessment paradigm. Perceived harm to irradiated nuclear workers and the public is mainly reflected through calculated hypothetical increased cancers.
    [Show full text]
  • Modelling Exposure-Response Relationships for Ionizing and Non-Ionizing Radiation
    Modelling Exposure-response Relationships for Ionizing and Non-ionizing Radiation Daniel Krewski, PhD, MHA Professor and Director McLaughlin Centre for Population Heath Risk Assessment & Risk Sciences International American Association of Physicists in Medicine (AAPM) Denver, Colorado August 2, 2017 Outline • A New Framework for Risk Science • Key Characteristics of Human Carcinogens • Ionizing Radiation – Sources of exposure – Medical uses of radiation – Occupational and environmental radiation exposures – Radiation hormesis: what do the data Indicate? • Non-ionizing Radiation – Sources of exposure – Epidemiological studies of RF fields • Risk Communication, Risk Perception and Risk Decision Making McLaughlin Centre for Population Health Risk Assessment The Next Generation Risk Science McLaughlin Centre for Population Health Risk Assessment Next Generation Risk Assessment McLaughlin Centre for Population Health Risk Assessment Three Cornerstones • New paradigm for toxicity testing (TT21C), based on perturbation of toxicity pathways • Advanced risk assessment methodologies, including those addressed in Science and Decisions • Population health approach: multiple health determinants and multiple interventions McLaughlin Centre for Population Health Risk Assessment Key Characteristics of Human Carcinogens McLaughlin Centre for Population Health Risk Assessment What can we learn about human cancer based on 50 years of cancer research? McLaughlin Centre for Population Health Risk Assessment IARC Scientific Publication No. 165 • Twenty chapters
    [Show full text]
  • Radiation Hormesis
    JAERI-Conf 2005-001 JP0550169 33 Evidence for beneficial low level radiation effects and radiation hormesis L.E. Feinendegen Heinrich-Heine-University Dtisseldorf, Germany; Brookhaven National Laboratory, Upton, NY, USA Abstract Low doses in the mGy range cause a dual effect on cellular DNA. One effect concerns a relatively low probability of DNA damage per energy deposition event and it increases proportional with dose, with possible bystander effects operating. This damage at background radiation exposure is orders of magnitudes lower than that from endogenous sources, such as ROS. The other effect at comparable doses brings an easily observable adaptive protection against DNA damage from any, mainly endogenous sources, depending on cell type, species, and metabolism. Protective responses express adaptive responses to metabolic perturbations and also mimic oxygen stress responses. Adaptive protection operates in terms of DNA damage prevention and repair, and of immune stimulation. It develops with a delay of hours, may last for days to months, and increasingly disappears at doses beyond about 100 to 200 mGy. Radiation-induced apoptosis and terminal cell differentiation occurs also at higher doses and adds to protection by reducing genomic instability and the number of mutated cells in tissues. At low doses, damage reduction by adaptive protection against damage from endogenous sources predictably outweighs radiogenic damage induction. The analysis of the consequences of the particular low-dose scenario shows that the linear-no-threshold (LNT) hypothesis for cancer risk is scientifically unfounded and appears to be invalid in favor of a threshold or hormesis. This is consistent with data both from animal studies and human epidemiological observations on low-dose induced cancer.
    [Show full text]
  • Background Radiation Impacts Human Longevity and Cancer Mortality
    bioRxiv preprint doi: https://doi.org/10.1101/832949; this version posted November 6, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Background radiation impacts human longevity and cancer mortality: Reconsidering the linear no-threshold paradigm Elroei David1*, Ph.D., Marina Wolfson2, Ph.D., Vadim E. Fraifeld2, M.D., Ph.D. 1Nuclear Research Center Negev (NRCN), P.O. Box 9001, Beer-Sheva, 8419001, Israel. 2The Shraga Segal Department of Microbiology, Immunology and Genetics, Faculty of Health Sciences, Center for Multidisciplinary Research on Aging, Ben-Gurion University of the Negev, Beer Sheva 8410501, Israel. *Corresponding author: Elroei David, PhD, e-mail: [email protected] Keywords: background radiation, longevity, cancer, United States Running title: Background Radiation, Human Longevity and Cancer Mortality Number of words (body text + cover page + figure legends): 2302 Number of figures: 3 Number of tables: 1 Number of references: 28 1 bioRxiv preprint doi: https://doi.org/10.1101/832949; this version posted November 6, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Abstract BACKGROUND The current linear-no-threshold paradigm assumes that any exposure to ionizing radiation carries some risk, thus every effort should be made to maintain the exposures as low as possible. Here, we examined whether background radiation impacts human longevity and cancer mortality. METHODS Our data covered the entire US population of the 3139 US counties, encompassing over 320 million people.
    [Show full text]
  • Radiation Hormesis: Real Or Not? (PDF)
    Radiation Hormesis: Real or Not? 22.01 – Intro to Radiation December 7th, 2015 22.01 – Intro to Ionizing Radiation Hormesis, Slide 1 What Is the Idea of Hormesis? From Saha, p. 17 • A little bit of a bad thing can be good • What are some examples? 22.01 – Intro to Ionizing Radiation Hormesis, Slide 2 Selenium: Helps or Hurts? https://saylordotorg.github.io/text_general-chemistry-principles-patterns-and-applications-v1.0/ Courtesy of Saylor Foundation. License CC BY-NC-SA. 22.01 – Intro to Ionizing Radiation Hormesis, Slide 3 Selenium: Helps or Hurts? © Association of Clinical Scientists, Inc. All rights reserved. This content is excluded from our Creative Commons license. For more information, see http://ocw.mit.edu/help/faq-fair-use/. 22.01 – Intro to Ionizing Radiation Hormesis, Slide 4 Arguments For/Against Selenium Hormesis • Taking megadoses of 200 mcg/day (4x the RDA) of selenium may have acute toxic effects, and showed no decreased incidence of prostate cancer mortality for low doses, and increased high- grade prostate cancer rates (~35,533 men) • Refs: Brasky TM, Kristal AR. J Natl Cancer Inst (2015) 107(1): dju375, Kenfield SA, et al. J Natl Cancer Inst (2015) 107 (1): dju360 • Selenium supplements of 200 mcg/day (4x the RDA) greatly reduced (63%) secondary prostate cancer evolution (974 men, 13 Se vs. 35 placebo cases, 11 years follow-up) • Ref: L. C. Clark et al. British Journal of Urology [1998, 81(5):730-734] 22.01 – Intro to Ionizing Radiation Hormesis, Slide 5 Models of Dose-Response D. P. Hayes. European Journal of Clinical Nutrition (2007) 61, 147–159 Linear- Control Inverted threshold U-shaped model Control hormesis Linear-no Control Hormesis threshold model model Control Courtesy of Macmillan Publishers Ltd.
    [Show full text]
  • Effective Doses of Ionizing Radiation During Therapeutic Peat
    International Journal of Environmental Research and Public Health Article Effective Doses of Ionizing Radiation during Therapeutic Peat Mud Treatment from a Deposit in the Knyszyn Forest (Northeastern Poland) Jacek Kapala * , Maria Karpinska and Stanislaw Mnich Department of Biophysics, Medical University of Bialystok, Mickiewicza 2A, 15-222 Bialystok, Poland; [email protected] (M.K.); [email protected] (S.M.) * Correspondence: [email protected] Received: 11 August 2020; Accepted: 17 September 2020; Published: 18 September 2020 Abstract: Radioactivity measurements of 61 therapeutic peat mud samples from the Podsokoldy deposits, near Suprasl, were performed using gamma spectrometry. The authors identified the 1 137 40 208 presence of 13 isotopes with the arithmetic mean of activity (in Bq kg− ): Cs-7, K-24, Tl-1, 212Bi-3, 212Pb-2, 228Ac-2, 210Pb-33, 214Bi-11, 214Pb-11, 226Ra-53, 234Th–47. The effective dose obtained during treatment with 15 peat mud baths (lasting 30 min) was 0.078 µSv. Use of peat mud compresses in the same number and period of exposure to the entire body surface caused absorption of a dose of 0.153 µSv. The authors discuss the probability of tissue radiation from isotopes present in the peat mud. In light of radiobiological knowledge, the therapeutic effect of ionizing radiation during peat mud therapy appears to be very unlikely. Keywords: natural radioactivity; effective radiation dose; peat mud 1. Introduction For years, many diseases have been treated with peat mud in balneology. Numerous papers contain observations indicating the ion-exchange characteristics of the organic materials contained in peat mud [1–4].
    [Show full text]
  • Remedy for Radiation Fear — Discard the Politicized Science J
    48 Plenary Session III (Wednesday, February 12, 2014 08:30) Remedy for Radiation Fear — Discard the Politicized Science J. Cuttler Cuttler & Associates Inc, Mississauga, Canada ABSTRACT While seeking a remedy for the crisis of radiation fear in Japan, the author reread a recent article on radiation hormesis. It describes the motivation for creating this fear and mentions the evidence, in the first UNSCEAR report, of a factor of 3 reduction in leukemia incidence of the Hiroshima atom-bomb survivors in the low dose zone. Drawing a graph of the data reveals a hormetic J-curve, not a straight line as reported. UNSCEAR data on the lifespan reduction of mice and Guinea pigs exposed continuously to radium gamma rays indicate a threshold at about 2 gray per year. This contradicts the conceptual basis for radiation protection and risk determination that was established in 1956-58. In this paper, beneficial effects and thresholds for harmful effects are discussed, and the biological mechanism is explained. The key point: the rate of spontaneous DNA damage (double-strand breaks) is more than 1000 times the rate caused by background radiation. It is the effect of radiation on an organism's very powerful adaptive protection systems that determines the dose-response characteristic. Low radiation up-regulates the adaptive protection systems, while high radiation impairs these systems. The remedy for radiation fear is to expose and discard the politicized science. INTRODUCTION Almost three years have passed since a major earthquake and devastating tsunami damaged the Fukushima- Daiichi nuclear power plant. An evacuation order forced 70,000 people to leave the area, while an additional 90,000 left voluntarily and subsequently returned.
    [Show full text]
  • A Concept of Radiation Hormesis. Stimulation of Antioxidant Machinery in Rats by Low Dose Ionizing Radiation
    Original Article A concept of radiation hormesis. Stimulation of antioxidant machinery in rats by low dose ionizing radiation Abstract Shilpa Sharma1 MSc (Hons), Objective: The concept of radiation hormesis has been the matter of discussion with regard to benecial eects to biological systems from low doses of ionizing radiations. However, its molecular basis is not well 1 NehaSingla MSc, PhD understood till now and the present study is a step forward to elucidate how low levels of ionizing radiation Vijayta Dani Chadha2 MSc, PhD, prove benecial for functioning of biological systems. Materials and Methods: Female Wistar rats weighing 1,2 100-120g were divided into four dierent groups. Each group consisted of eight animals. The animals in Gro- D.K. Dhawan MSc, DMRIT, PhD up I served as normal controls for Group II animals which were subjected to whole body X-rays exposure of 20rads and were sacriced 6 hours following exposure. Group III animals served as normal controls for gro- up IV animals which were given whole body X-rays radiation of 20rads and were sacriced 24 hours follow- ing exposure. Results: The levels of reduced glutathione (GSH), total glutathione (TG) were increased in li- 1. Department of Biophysics, ver, kidney, brain and blood after 6hrs as well as 24hrs following X-rays exposure. On the contrary, no signi- Panjab University, cant change in the oxidized glutathione (GSSG) content was observed following X-rays irradiation in any of the organs. Further, the low dose of X-rays resulted in a signicant decrease in the lipid peroxidation (LPO) in Chandigarh, India-160014 liver, kidney and brain, whereas it caused an increase in LPO levels in blood.
    [Show full text]