SOURCES, EFFECTS AND IONIZING RADIATION
SOURCES, EFFECTSAND RISKSOF IONIZING RADIATIONUnited Nations Scientific Committee on the Effectsof Atomic Radiation1988 Report to the General Assembly, with annexesUNITED NATIONSNew York, 1988
NOTEThe report of the Committee without its annexes appears as Official Records of theGeneral Assembly, Forty-third Session, Supplement No. 45 (A/43/45).The designations employed and the presentation of material in this publication d onot imply the expression of any opinion whatsoever on the part of the Secretariat of theUnited Nations concerning the legal status of any country, territory, city or area. or of itsauthorities, or concerning the delimitation of its frontiers o r boundaries.UNITED NATIONS PUBLICATIONSales No. E.88.IX.7ISBN 92-1- 142143-809000P
CONTENTSPageReport of the United Nations Scientific Committee on the Effects of AtomicRadiation to the General .4ssembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Scientific Annexes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Annex A. Exposures from natural sources of radiation . . . . . . . . . . . . . . .Annex B. Exposures from nuclear power production . . . . . . . . . . . . . . . . . . .Annex C. Exposures from medical uses of radiation. . . . . . . . . . . . . . . .Annex D. Exposures from the Chernobyl accident . . . . . . . . . . . . . .Annex E. Genetic hazards. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Annex F. Radiation carcinogenesis in man. . . . . . . . . . . . . . . . . . . . . . . . . . .Annex G. Early effects in man of high doses of radiationand Appendix: Acute radiation effects in victims of the Chernobylnuclear power plant accident . . . . . . . . . . . . . . .
Report of the United Nations Scientific Committeeon the Effects of Atomic Radiationto the General Assembly
CONTENTS1. HlSTORlCAL REVlEW .8-135AGeneral considerations .8-10B. Concepts quantities and units11-41I . Activity .12-1415-242. Radiation dose .3. Development of dosimetric concepts . 25-40C. Dose assessments .42-851. Natural sources of radiation .2. Nuclear explosions .3. Nuclear power production4 . Medical exposures .5. Occupational exposures .6. Miscellaneous exposures .7. Accidents and incidents .D . Riskassessments .I . Hereditary harm .2. Cancer .3. Non-stochastic effects .4 . Other typesofharm .11. T H E PRESENT SITUATION . 136-270A . Radiation levels and doses . 136-185I . Natural sources of radiation .2. Nuclear explosions .3. Nuclear power production .4 . Medical exposures .5. Occupational exposures .6. Miscellaneous exposures .7. .4ccidents .8. The Chernobyl accident .B . Radiation effects .I . Hereditary harm .2. Radiation carcinogenesis in man .3 . Early effects in man of high doses of radiation .4 . Effects of pre-natal irradiation .C. Derivation of risk coefficients .I . Hereditaryharm .2 . Cancer .D Comparisonoferposures .I . Previous UNSCEAR comparisons .2. Purposeofcomparisons .3. Comparison of collective doses .4 . Comparison of individual doses .5. Summary of dose comparisons .6. Direct comparison of detriments .Appendices 'Pages1. Members of national delegations .4311. Scientific staff and consultants who have co-operated with the Committee inthe preparation of this report .44111. Reports received by the Committee .45.
INTRODUCTION1. This is the tenth in a series of substantive reportsof the United Nations Scientific Committee on theEffects of Atomic Radiation (UNSCEAR)" to theGeneral s s e m b l The . preparation of this Reporta n d its scientific annexes took place from the thirtyfirst to the thirty-seventh sessions of the Committee.The material of this report was developed at annualsessions of the o m m i r t e e based,on i o r k i n g papersprepared by the Secretariat that were modified andamended from one session to the next according to theCommittee's requests. During the period of preparation of this K e o r t .which contains seven scientificannexes. another Report containing three scientificannexes was completed at the thirty-fifth session ofthe Committee. These two reports, referred to as the1986 and 1988 R e o r t s .constitute the latest comprehensi\e assessment by the Committee of thesources. effects and risks of ionizing radiation.2. The follo\ving members of the Committee servedas Chairmen, Vice-Chairmen and Rapporteurs, respectively. at the following sessions: thirty-first session. Z.Jaworowski (Poland), D. Beninson (Argentina) and T.K u n a t o r i(Japan); thirty-second and thirty-third sessions: D. Beninson (.4rgentina). T. Kumatori (Japan)a n d A. Hidayatalla (Sudan); thirty-fourth and thirtyfifth sessions: T. Kumatori (Japan), A. Kaul (FederalOThe United Sations Scientific Comm tteeon the Effects o iAtomic Radiation was established by the General Asaembl) at11s tenth sesslon in 1955. Its terms o i reference are set out Inresolution 913 (X). It was or ginally composed of the folloulngMember States: Argentina. Australia. Belg urn. Hra7il. Canada.Czechoslovakia. Egypt. France, India. Japan. Mexico. Sweden.Union of S o i e tSocialist Republics. lJnited Kingdom of GreatBritain and Northern Ireland and United States of America. Themembership of the Committee was subsequentl\. enlarged b) theGeneral .Assembly in its resolution 3154C (XSVIII) to lncludeGermany. Federal Republic of. Indonesia. Peru. Poland and Sudan.By resolution .\/RES/31/6ZB the General .Assembly increased themembership of the Committee to a maximum of 21 and invited thePeople's Republic of China to become a member.h r e v i o u ssubstantive reports of the United Nation* SclcnttficCommitlee on the Effects of Atomic Radiation to the GeneralAssembly arc to be foulld in Official Records 01' the General.-2ssembly. Thirteenth Session, Supplenlent No. 17 (A/3838): ibid.,Se\,enteenth Session. Supplement So. 16 (A/52161; ibid. NineteenthSession. Supplement S o . 14 (A/58l4): ibid. Twenty-first Session.Supplement No. I4 (A/63 14): ibid. Twenty-fourth Session. Supplement No. 13 (A/7613): ibid. Twenty-seventh Session. SupplementNo. 25 (A/8715); ibid. Thirty-second Session. Supplement 10(A/32/40); ibid. Thiny-seventh Session. Supplement S o . 45(A/37/45): ibid. Forty-first Session. Supplement No. 16 (A/4 1/16).These documents are referred to as the 1958. 1962. 1964. 1966. 1969.1972. 1977. 1982 and 1986 Reports. respectivrl . The 1971 Rrpt rtwith scientific annexes \vas published as: lonizlng Radlat on:Levelsand Effects. \.'olume I: Le\,els. Volume 11: Effects (United SationsPublication. Sales No. E.72.IX.17 and 18). The 1977 Report w t hscientific annexes was published as: Sources and Effects of lonl7ingRadiation (United Nations Publication. Sales No. E.77.1X.I). The1982 Report with scientific annexes tvas published as: IonizingRadiation: Sources and Biological Effects (United Nations Publication. Sales No. E.82.IX.X). The 1986 Repon with scientific annexeswas published as: Genetic and Somatic Effects of Ionizing Radiation(United Nat onsPublication, Sales No. E.86.1X.9).Republic of Germany) and A. Hidayatalla (Sudan):thirty-sixth and thirty-seventh sessions: B. Lindell(Sweden), K.H. Lokan (Australia) and J. Maisin(Belgium). The names of those experts who attendedthe thirty-first to the thirty-seventh sessions of theCommittee in an official capacity as representatives o rmembers of national delegations are listed in Appendix I.3. In approving this Report. and assuming thereforefull responsibility for its content, the Committeewishes to acknowledge the help and advice given by asmall group of consultants who assisted in thepreparation of the test and scientific annexes, uponappointment by the Secretary-General. Their namesare given in Appendix 11. The) were responsible forthe preliminary reviews and evaluation of the technicalinformation received by the Committee or available inthe open scientific literature, on which rest the finaldeliberations of the Committee. Additional assistanceand financial support for the preparation of some ofthe scientific annexes were offered to the Committeeby various international and national organizations.The Committee would like to express its gratitude t othese organizations, which are listed in the relevantannexes.4.The sessions of the Committee held during theperiod under review \rere attended b\ representativesof the United Nations Environment Programme(UNEP), the World Health Organization (WHO), theFood and Agriculture Organization of the UnitedNations (FAO). the International Atomic EnergyAgency (IAEX), the International Commission onRadiological Protection (ICRP) and the InternationalCommission on Radiation Units and measurements(ICRU). The Comn itteeLvishes to acknowledge theircontributions to the discussions.5 . Reports received by the Committee from MemberStates of the United Nations and members of thespecialized agencies and the International AtomicEnergy Agency, as well as from these agenciesthemselves, during the period from 19 .4pril 1986 to17 June 1988 are listed in Appendix 111. Reportsreceived before 19 April 1986 were listed in previousReports of the Committee to the General Assembly.This information received officially by the Comn itteeivas supplemented by, and interpreted with the helpof, many other data available in the current scientificlirerature or, in a few cases, from unpublishedconlmunications by individual scientists6. In the following Report the Committee summarizesthe main conclusions of the specialized studies undertaken, also in the light of previously released substantive documents. The material is presented a t the mostgeneral level possible, in view of the difficult concepts
a n d notation that characterize this field. After achapter summarizing the developments and trendsthat have become apparent throughout the years, thehighlights and conclusions to be drawn from the mostrecent studies in the fields of radiation physics andbiology are presented. This main text is followed bythe supporting scientific annexes, which are written ina format a n d a language that are essentially aimed a tspecialists.7. Following established practice, only the main textof the Report is submitted to the General Assembly,while the full Report. including the scientific annexes,will be issued as a United Nations sales publicationr.This practice is intended to achieve widerdisseminationof the findings for the benefit of the internationalscientific community. The Committee wishes t o drawthe attention of the General Assembly to the fact thatthe main text of the Report is presented separatelyfrom its scientific annexes simply for the sake ofconvenience. It should be understood that the scientificdata contained in the annexes are of great importancebecause they form the basis for the conclusions of thereport.CUnited Nations Publication. Sales No. E.88.IX.7.
I. HISTORICAL REVIEWA.GENERAL CONSIDERATIONS8. Throughout the thirty-three years of its existence.the Committee has assertively attempted to providethe best possible estimates of: (a) doses received by theworld's population in the past, a n d expected to bereceived in the future, from various natural and manmade sources of radiation, and (b) risks of inductionof various types of harm by radiation, both in theshort term and the long term. by individuals directlyreceiving such doses or by their descendants overmany generations.9. With the passing of time and the increase innumber and complexity of the Reports issued by theCommittee, it is becoming increasingly difficult, evenfor the specialists, to trace back to earlier publicationsthe development of the main ideas underlying theCommittee's assessments and how these assessmentshave changed with time and as a result of increasingscientific knowledge. It would seem useful, therefore,to make available in compact, summary form themain conclusions reached in the fields mentionedabove. This summary is intended to serve a number ofpurposes. First, it will inform the General Assemblyabout the Committee's work and its findings. Second,for the Committee's membership which has beenchanging gradually over the years, it will form a recordof how the Committee's thinking has evolved. Lastly, itwill be placed at the disposal of the internationalscientific community, for whom UNSCEAR Reportsa n d scientific annexes have become a basic reference.10. What follows in this chapter is therefore asummary of the Committee's assessments in the fieldsof dose estimation (which pertains closely to thesubjects of physics) and risk assessment (which involvesphysical as well as radiobiological and medical considerations). It aims at giving an account of both thegeneral principles underlying the estimates and theconclusions reached, in a language that is as plain asthe complexity of the subjects allows but withoutmuch of the discussions supporting the choices madethis, as well as for otherat any particular time.technical and methodological details, reference ismade to the Reports to the General Assembly issuedfrom 1958 to 1986. A complete list of these publications issued by the Committee appears in footnote bto paragraph 1 of this Report. Current assessments areexamined in more detail in the following chapter 11.orB.CONCEPTS, QUANTITIES AND UNITSI I. Radiation is a transport of energy through space.In traversing material, radiated energy is absorbed. Inthe case of ionizing radiation, which is the type ofradiation that concerns the Committee. the absorptionprocess consists in the removal of electrons from theatoms. producing ions. lonizing radiation may beproduced in man-made devices, such as x-ray tubes. o rit may come from the disintegration of radioactivenuclides. the phenomenon that is called radioactivity.While nuclides such as these occur naturally. they mayalso be produced artificially. as in nuclear reactors.The two basic quantities in the assessment of radiationlevels and effects are the activity of a radioactivematerial and the radiation dose. The Committee usesthe system of radiation quantities and units adopted in1980 by the International Commission o n RadiationUnits and Measurements (ICRU).1. Activity12. The acriviry of a radioactive material is thenumber of nuclear disintegrations per unit time. Theunit that the Committee used for this quantity u p t oand including its 1977 Report was the curie (Ci),which is 37 billion (3.7 10l0) disintegrations persecond, a number which was originally introducedbecause it is the approximate activity of 1 gram ofradium-226.13. The present unit of activity has been given thespecial name becquerel (Bq). One becquerel is onedisintegration per second.13. The word radioactivity denotes the phenomenonof radioactive disintegration. It is not a synonym for"activity", nor should it be used t o mean "radioactivematerial".2.Radiation dose15. The term radiation dose can mean several things(e.g., absorbed dose. dose equivalent o r effective doseequivalent). The absorbed dose of radiation is theenergy imparted per unit mass of the irradiatedmaterial. Up t o and including the 1977 Report, theCommittee used the rad as the unit of absorbed dose(1 rad 0.01 joule/kg). The present unit of absorbeddose is joule/kg. for which the special name gray (Gy)is used. Thus. 1 rad 0.01 joule/kg 0.01 Gy.16. Different types of radiation have different Relative Biological Effectiveness (RBE). The RBE of onetype of radiation in relation to a reference type ofradiation (usually x or gamma) is the inverse ratio ofthe absorbed doses of the two radiations needed tocause the same degree of the biological effect forwhich the RBE is given.17. When the first UNSCEAR Reports were prepared,the International Commission on Radiological Protec-
tion (ICRP) had recommended certain values of RBEfor the purposes of radiation protection. The absorbeddoses of various radiations were multiplied by thesevalues to arrive at doses weighted for the purposes ofradiation protection (e.g., for comparison with doselimits). The unit of this weighted absorbed dose wascalled rem.18. The use of the term RBE in two contexts.radiation protection (where it only meant the standardvalues recommended by ICRP) and in radiobiology(where it meant the most likely value in a givenexposure situation for a specified biological effect),caused some problems. ICRP and ICRU thereforedecided to establish a new quantity, the dose equivalenr.This would be the product of the absorbed dose and aso-called quality factor (first denoted QF and later Q),and its unit would be the rem. The quality factor \stasgiven by ICRP as a function of the capacity of eachradiation to produce ionization, expressed as thelinear energy transfer (LET). For practical applications, ICRP suggested that it would sufiice to useapproximations of average values, i.e. one uniquevalue of QI: (Q) for each type of radiation. Itsuggested values of Q 1 for x rays, gamma rays andbeta particles, Q 10 for fast neutrons (changed toQ 20 in 1985). Q 10 for alpha particles (changedto Q 20 in 1977), and Q 20 for heavy particles.The Committee has also used these factors butcontinued to use Q 10 for fast neutrons.19. In the UNSCEAR Reports, when doses areexpressed in rern, the ICRP values of "RBE (protection)", Q F or Q have been used in most cases.however, when authors express doses in rem, they mayhave used the primary, LET-related definition of QF(Q).20. When the Committee began in 1982 to apply thenew international unit system and the absorbed dosewas given in Gy instead of rad. the new unit for doseequivalent was named the sieverr (Sv).2 1. In addition to absorbed dose and dose equivalent.there is a third quantity that may be meant when anauthor speaks of radiation dose, namely. the e.rposure.Exposure is the total electrical charge of ions of onesign produced in air by electrons liberated by x orgamma rays per unit mass of irradiated air. Since theexposure is a measure of the ionization that x- orgamma-radiation would produce in air. it is thereforeonly applicable for those types of radiation. The unitof exposure is couiomb/kg, but the old unit,
Radiation (United Nations Publication. Sales No. E.77.1X.I). The 1982 Report with scientific annexes tvas published as: Ionizing Radiation: Sources and Biological Effects (United Nations Publica- tion. Sales No. E.82.IX.X). The 1986 Repon with scientific annexes was published as: Genetic and Somatic Effects of Ionizing Radiation
Non-ionizing radiation. Low frequency sources of non-ionizing radiation are not known to present health risks. High frequency sources of ionizing radiation (such as the sun and ultraviolet radiation) can cause burns and tissue damage with overexposure. 4. Does image and demonstration B represent the effects of non-ionizing or ionizing radiation?
Ionizing radiation: Ionizing radiation is the highenergy radiation that - causes most of the concerns about radiation exposure during military service. Ionizing radiation contains enough energy to remove an electron (ionize) from an atom or molecule and to damage DNA in cells.
Ionizing & Non-Ionizing Radiation Interest in this area of potential human hazard stems, in part, from the magnitude of harm or damage that an individual who is exposed can experience. It is widely known that the risks associated with exposures to ionizing radiation are significantly greater than compa-rable exposures to non-ionizing radiation.
you about non-ionizing radiation, such as microwaves, ultrasound, or ultraviolet radiation. Exposure to ionizing radiation can come from many sources. You can learn when and where you may be exposed to sources of ionizing radiation in the exposure section below. One source of exposure is from hazardous waste sites that contain radioactive waste.
Non-Ionizing Radiation Non-ionizing radiation includes both low frequency radiation and moderately high frequency radiation, including radio waves, microwaves and infrared radiation, visible light, and lower frequency ultraviolet radiation. Non-ionizing radiation has enough energy to move around the atoms in a molecule or cause them to vibrate .
Ionizing radiation can be classified into two catego-ries: photons (X-radiation and gamma radiation) and particles (alpha and beta particles and neutrons). Five types or sources of ionizing radiation are listed in the Report on Carcinogens as known to be hu-man carcinogens, in four separate listings: X-radiation and gamma radiation .
non-ionizing EMF radiation exposure safety standards are based primarily on stand-alone radiation exposures. When combined with other agents, the adverse effects of non-ionizing EMF radiation on biological systems may be more severe. Much work remains to be done before definitive statements about non-ionizing
M. Peskin and D. Schroeder, An Introduction to Quantum Field Theory This is a very clear and comprehensive book, covering everything in this course at the right level. It will also cover everything in the \Advanced Quantum Field Theory" course, much of the \Standard Model" course, and will serve you well if you go on to do research. To a large extent, our course will follow the rst section of .
