1. IAEA International Atomic Energy Agency PGEC Part IV The International System of Radiation Protection and the Regulatory Framework Module IV 3 Introduction to ICRP’s Recommendations Postgraduate Educational Course in radiation protection and the Safety of Radiation sources

2. IAEA This module will discuss ICRP's Recommendations and includes: Introduction Introduction Brief review of biological aspects and quantities used in radiation protection Brief review of biological aspects and quantities used in radiation protection The system of radiological protection of humans The system of radiological protection of humans The principles of radiological protection The principles of radiological protection Medical exposure of patients Medical exposure of patients Protection of the environment Protection of the environment Overview of Module IV.3 2

3. IAEA ICRP Recommendations  ICRP’s International System of Radiological Protection is used world-wide as the common basis for radiological protection standards & legislation.  ICRP has published more than 100 reports on all aspects of radiological protection. In particular they have published the following recommendations: Publication 26 1977 Publication 26 1977 Publication 60 1990 Publication 60 1990 Publication 103 2007 Publication 103 2007 3

4. IAEA Introduction Latest ICRP Recommendations - Publication 103, 2007 – contents are:  Introduction  Aims and Scope  Biological Aspects of Radiological Protection  Quantities used in Radiological Protection  The System of Radiological Protection in Humans  Implementing Recommendations  Medical Exposure  Protection of the Environment

5. IAEA Types of harmful effect ICRP103 deals with two types of harmful effect.  High doses will cause deterministic effects (harmful tissue reactions), often of an acute nature, which only appear if the dose exceeds a threshold value.  Both high and low doses may cause stochastic effects (cancer or heritable effects), which may be observed as a statistically detectable increase in the incidences of these effects occurring some time after exposure. 5 Thyroid cancer among exposed children of Belarus 1986-1997 due to Chernobyl accident

6. IAEA The aims of the Recommendations  (26) note 1 “The primary aim of the Commission’s Recommendations is to contribute to an appropriate level of protection for people and the environment against the detrimental effects of radiation exposure without unduly limiting the desirable human actions that may be associated with such exposure.”  (29) “The Commission’s system of radiological protection aims primarily to protect human health. Its health objectives are relatively straightforward: to manage and control exposures to ionising radiation so that deterministic effects are prevented, and the risks of stochastic effects are reduced to the extent reasonably achievable.” 6Note 1: paragraph numbers refer to ICRP103

7. IAEA Scope of the Recommendations  (44) “The Commission’s system of radiological protection applies to all radiation exposures from any source, regardless of its size and origin....”  ICRP Recommendations cover exposures to both natural and man-made sources  Although all level and types of radiation exposure are covered, this does not mean that they all can or need to be equally considered when establishing the legal and regulatory systems. 7

8. IAEA Exclusion & Exemption Two distinct concepts delineate the extent of radiological protection  exclusion of certain exposure situations: they are not amenable to control with regulatory instruments (cannot be regulated),  exemption from some or all radiological protection regulatory requirements for situations where such controls are regarded as unwarranted (need not be regulated). 8

9. IAEA Linear-non-threshold (LNT) model (65) “the practical system of radiological protection recommended by the ICRP will continue to be based upon the assumption that at doses below about 100 mSv, a given increment in dose will produce a directly proportionate increment in the probability of incurring cancer or heritable effects attributable to radiation. This dose-response model is generally known as ‘linear-non-threshold’ or LNT. This view accords with that given by UNSCEAR (2000).” (65) “the practical system of radiological protection recommended by the ICRP will continue to be based upon the assumption that at doses below about 100 mSv, a given increment in dose will produce a directly proportionate increment in the probability of incurring cancer or heritable effects attributable to radiation. This dose-response model is generally known as ‘linear-non-threshold’ or LNT. This view accords with that given by UNSCEAR (2000).” Underlying Conceptual basis Underlying Conceptual basis 9

10. IAEA Quantities used in Radiation Protection covered in PGEC PART II: QUANTITIES AND MEASUREMENTS – reminder below absorbed dose as the fundamental physical quantity the energy absorbed by a unit mass of a substance from the radiation, which has units of joule per kilogram and is termed the gray (Gy) absorbed dose as the fundamental physical quantity - the energy absorbed by a unit mass of a substance from the radiation, which has units of joule per kilogram and is termed the gray (Gy) the rate of spontaneous nuclear transformation of radionuclides is called the activity which has units of reciprocal seconds (sec -1 ) or disintegrations per second (dps) and is termed the Becquerel (Bq) the rate of spontaneous nuclear transformation of radionuclides is called the activity which has units of reciprocal seconds (sec -1 ) or disintegrations per second (dps) and is termed the Becquerel (Bq) Quantities and Units

11. IAEA radiation weighting factors Radiation type Radiation weighting factor, w R Photons 1 Electrons and muons 1 Protons and charged pions 2 Alpha particles 20 Fission fragments, heavy ions 20 Neutrons function of neutron energy 11

12. IAEA Tissue Weighting Factors, w T Tissue or Organ T ICRP 60 ICRP 103 Bone marrow 0.12 0.12 Colon 0.12 0.12 Lung 0.12 0.12 Stomach 0.12 0.12 Breast 0.05 0.12 Gonads 0.20 0.08 Bladder 0.05 0.04 Oesophagus 0.05 0.04 Liver 0.05 0.04 Thyroid 0.05 0.04 Skin 0.01 0.01 Bone surface 0.01 0.01 Brain – 0.01 Salivary gland – 0.01 Remainder 0.05 0.12 Total 1.0 1.0

13. IAEA Absorbed dose, Gy Quantities and Units Equivalent dose, Sv Absorbed dose weighted for harmfulness of different radiations Effective dose & committed effective dose, Sv Equivalent dose weighted for susceptibility to harm of different tissues Collective dose, manSv Effective dose to a group from a specified source within a specified time period wTwTwTwT  wRwRwRwR

14. IAEA System of radiation protection of humans ICRP 103 uses a situation-based approach for radiation exposures:  Planned situations involve the deliberate introduction and operation of sources. Planned exposure situations may give rise to normal exposures & potential exposures  Emergency situations may occur from any unexpected situation and require urgent action in order to avoid or reduce undesirable consequences.  Existing exposure situations already exist when a decision on control has to be taken, including prolonged exposure situations after emergencies. ICRP also classify types of exposure eg  occupational, medical, public 14

15. IAEA types of exposure  Occupational exposure: This refers to all exposure incurred by workers in the course of their work, with the exception of 1) excluded exposures and exposures from exempt activities involving radiation or exempt sources; 2) any medical exposure; 3) the normal local natural background radiation.  Medical exposure: Exposure incurred by patients as part of their own medical or dental diagnosis or treatment; patients as part of their own medical or dental diagnosis or treatment; persons, other than those occupationally exposed, knowingly, while voluntarily helping in the support and comfort of patients; persons, other than those occupationally exposed, knowingly, while voluntarily helping in the support and comfort of patients; volunteers in a programme of biomedical research involving their exposure volunteers in a programme of biomedical research involving their exposure  Public exposure: Exposure incurred by members of the public from radiation sources, excluding any occupational or medical exposure and the normal local natural background radiation 15

16. IAEA protection can be related to: A source giving rise to individual doses (source-related) Individual dose received from all the relevant sources (individual- related) source-related or individual-related

17. IAEA Key Principles of Radiological Protection Justification [source related ]  actions involving changes in exposure of individuals to be justified in advance - positive net benefit Optimisation [source related]  exposures should be as low as reasonably achievable [ALARA] and below dose constraints and reference levels  Dose ConstraintsDC concept proposed in Publication 60 given more prominence in Publication 103  Dose Constraints: DC concept proposed in Publication 60 given more prominence in Publication 103  Reference Levels: for emergency and existing exposure situations it is inappropriate to plan for exposures above the reference level, and below it optimisation of protection should be implemented. Dose Limits [individual related]  No change in ICRP 103 from ICRP60. NB DL for lens of the eye reduced* to 20 mSv/y ( averaged over defined periods of 5 years, with no single year exceeding 50 mSv ) * ICRP Statement on Tissue Reactions approved April 21, 2011  * ICRP Statement on Tissue Reactions approved April 21, 2011

18. IAEA Justification Sufficient individual or societal benefit to offset the associated detriment is needed before: introducing a new radiation source, introducing a new radiation source, reducing existing exposure, reducing existing exposure, Reducing the risk of potential exposure, Reducing the risk of potential exposure, (205)...The consequences to be considered are not confined to those associated with the radiation – they include other risks and the costs and benefits of the activity. Sometimes, the radiation detriment will be a small part of the total. Justification thus goes far beyond the scope of radiological protection..... To search for the best of all the available options, is usually a task beyond the responsibility of radiological protection agencies 18

19. IAEA Optimisation  The principle of optimisation of protection is source related and applies to all three exposure situations: planned, emergency, and existing; and is source related  The broad aim should be to ensure that the magnitude of the individual doses, the number of people exposed, and the likelihood of incurring exposures where these are not certain to be received, are all kept ALARA, economic and social factors being taken into account  (214) Optimisation is always aimed at achieving the best level of protection under the prevailing circumstances through an ongoing, iterative process that involves: evaluation of the exposure situation, including any potential exposures (the framing of the process); evaluation of the exposure situation, including any potential exposures (the framing of the process); selection of an appropriate value for the constraint or reference level; selection of an appropriate value for the constraint or reference level; identification of the possible protection options; identification of the possible protection options; selection of the best option under the prevailing circumstances; and selection of the best option under the prevailing circumstances; and implementation of the selected option. implementation of the selected option. 19

20. IAEA International Atomic Energy Agency Dose Constraints & Reference Levels Planned exposure situations Existing and emergency exposure situations Optimisation Dose limit Dose constraint Reference level

21. IAEA Dose Constraint  A prospective and source-related restriction on the individual dose from a source, which provides a basic level of protection for the most highly exposed individuals from a source, and serves as an upper bound on the dose in optimisation of protection for that source  Not a limit! 21

22. IAEA Reference Level  Reference Level - the level of dose or risk, above which it is judged to be inappropriate to plan to allow exposures to occur - and below which optimisation of protection should be implemented.  The chosen value for a reference level will depend upon the prevailing circumstances of the exposure situation under consideration  All Exposure Pathways and all relevant protection options should be considered, and ICRP recommends 3 dose bands for reference levels (and dose constraints). 22

23. IAEA Framework for dose constraints and reference levels BANDS OF DOSECHARACTERISTICS AND REQUIREMENTS >20 - 100 mSv Exceptional situations. Benefit on a case-by-case basis. Information, training and individual monitoring of workers, assessment of public doses. >1 - 20 mSv Individual direct or indirect benefit. Information, training and either individual monitoring or assessment. 1 mSv or less Societal benefit (not individual). No information, training or individual monitoring. Assessment of doses for compliance. 23

24. IAEA Dose Limits  Dose limitation is individual-related rather than source related  Dose limits apply only in planned exposure situations, but not to medical exposures of patients.  Some misconceptions about function of dose limits  The dose limit is widely, but erroneously, regarded as a line of demarcation between “safe” and “dangerous”  It is also widely, and erroneously, seen as the most simple and effective way of keeping exposures low and forcing improvements  It is commonly seen as the sole measure of the stringency of a system of protection 24

25. IAEA Medical exposure of patient  Medical Exposure of Patients, Comforters and Carers, and Volunteers in Biomedical Research require an approach that differs from other planned exposure situations  (322) “Medical exposures are predominantly delivered to individuals (patients) undergoing diagnostic examinations, interventional procedures, or radiation therapy. Other individuals caring for and comforting patients are also exposed to radiation.....” 25

26. IAEA RP Principles Applied to Medical Exposures Justification - 3 levels : Optimisation – Diagnosis: exposure of patients be the minimum required to achieve the intended diagnostic objective Diagnostic Reference Levels (DRLs) Therapy: not only deliver prescribed dose to tumour but also plan protection outside the target volume Dose limitation inappropriate for medical exposures medical use of radiation the radiological procedure for the individual patient

27. IAEA The principle of justification in medical exposure 27  (209) The principle aim of medical exposures is to do no more harm than good to the patient, due account being taken of the radiation detriment from the exposure of the radiological staff and of other individuals.  (330) The principle aim of medical exposures is to do no more harm than good to the patient, subsidiary account being taken of the radiation detriment from the exposure of the radiological staff and of other individuals.

28. IAEA Protection of the Environment New recommendations have not arisen from any new or specific concerns about the effects of radiation on the environment Fills a conceptual gap Previously: protect the public thus adequately protect the environment Previously: protect the public thus adequately protect the environment Now: consider a wider range of environmental situations, irrespective of any human connection with them Now: consider a wider range of environmental situations, irrespective of any human connection with them 28

29. IAEA Dose Assessment Methodology - Biota TOTAL ABSORBED DOSE ECOLOGICAL PARAMETERS REFERENCE Animal and Plant RADIONUCLIDE SOURCE IMPACT PATHWAY OF EXPOSURE Application of a weighting factor for RBE Compare predicted dose to known biological or ecological effects & guideline values

30. IAEA Reference Animals and Plants  “Environmental Protection - the Concept and Use of Reference Animals and Plants”, ICRP 108  “Environmental Protection: Transfer Parameters for Reference Animals and Plants” ICRP 114  ICRP 108 introduces the concept of Reference Animals and Plants (RAP) and defines a set of 12 RAPs  RAP are hypothetical entities with defined anatomical, physiological, and life-history properties  ICRP 114 includes data to estimate whole body doses received by RAPs, in relation to internal and external radionuclide concentrations; and outlines what is known about the effects of radiation on such types of animals and plants 30

31. IAEA Catalogue of ICRP Publications… ICRP Publication 119Compendium of Dose Coefficients based on ICRP Publication 60 ICRP Publication 118 ICRP Statement on Tissue Reactions / Early and Late Effects of Radiation in Normal Tissues and Organs – Threshold Doses for Tissue Reactions in a Radiation Protection Context ICRP Publication 117Radiological Protection in Fluoroscopically Guided Procedures outside the Imaging Department ICRP Publication 116Conversion Coefficients for Radiological Protection Quantities for External Radiation Exposures ICRP Publication 115Lung Cancer Risk from Radon and Progeny and Statement on Radon ICRP Publication 114Environmental Protection: Transfer Parameters for Reference Animals and Plants ICRP Publication 113Education and Training in Radiological Protection for Diagnostic and Interventional Procedures ICRU Report 84 (prepared jointly with ICRP) Reference Data for the Validation of Doses from Cosmic-Radiation Exposure of Aircraft Crew ICRP Publication 112Preventing Accidental Exposures from New External Beam Radiation Therapy Technologies ICRP Publication 111 Application of the Commission's Recommendations to the Protection of People Living in Long-term Contaminated Areas After a Nuclear Accident or a Radiation Emergency ICRP Publication 110Adult Reference Computational Phantoms ICRP Publication 109 Application of the Commission's Recommendations for the Protection of People in Emergency Exposure Situations ICRP Publication 108Environmental Protection - the Concept and Use of Reference Animals and Plants ICRP Publication 107Nuclear Decay Data for Dosimetric Calculations ICRP Publication 106Radiation Dose to Patients from Radiopharmaceuticals - Addendum 3 to ICRP Publication 53 ICRP Publication 105Radiological Protection in Medicine ICRP Publication 104Scope of Radiological Protection Control Measures ICRP Publication 103The 2007 Recommendations of the International Commission on Radiological Protection 31

32. IAEA ICRP Publication 102Managing Patient Dose in Multi-Detector Computed Tomography (MDCT) ICRP Supporting Guidance 5 Analysis of the Criteria Used by the ICRP to Justify the Setting of Numerical Protection Level Values ICRP Publication 101bThe Optimisation of Radiological Protection - Broadening the Process ICRP Publication 101aAssessing Dose of the Representative Person for the Purpose of the Radiation Protection of the Public ICRP Publication 100Human Alimentary Tract Model for Radiological Protection ICRP Publication 99Low-dose Extrapolation of Radiation-related Cancer Risk ICRP Publication 98Radiation Safety Aspects of Brachytherapy for Prostate Cancer using Permanently Implanted Sources ICRP Publication 97Prevention of High-dose-rate Brachytherapy Accidents ICRP Publication 96Protecting People against Radiation Exposure in the Event of a Radiological Attack ICRP Supporting Guidance 4 Development of the Draft 2005 Recommendations of the ICRP - A Collection of Papers ICRP CD3Database for Dose Coefficients: Doses to Infants from Mothers' Milk ICRP Publication 95Doses to Infants from Ingestion of Radionuclides in Mothers' Milk ICRP Publication 94Release of Patients after Therapy with Unsealed Radionuclides ICRP Publication 93Managing Patient Dose in Digital Radiology ICRP Publication 92Relative Biological Effectiveness, Radiation Weighting and Quality Factor" ICRP Publication 91A Framework for Assessing the Impact of Ionising Radiation on Non-human Species ICRP Publication 90Biological Effects after Prenatal Irradiation (Embryo and Fetus) ICRP Publication 89Basic Anatomical and Physiological Data for Use in Radiological Protection Reference Values ICRP Supporting Guidance 3 Guide for the Practical Application of the ICRP Human Respiratory Tract Model ICRP Supporting Guidance 2 Radiation and your patient - A Guide for Medical Practitioners ICRP CD2Database of Dose Coefficients: Embryo and Fetus ICRP Publication 88Doses to the Embryo and Fetus from Intakes of Radionuclides by the Mother 32

33. IAEA ICRP Publication 87Managing Patient Dose in Computed Tomography ICRP Publication 86Prevention of Accidents to Patients Undergoing Radiation Therapy ICRP Publication 85Avoidance of Radiation Injuries from Medical Interventional Procedures ICRP Publication 84Pregnancy and Medical Radiation ICRP Publication 83Risk Estimation for Multifactorial Diseases ICRP Publication 82Protection of the Public in Situations of Prolonged Radiation Exposure ICRP Publication 81Radiation protection recommendations as applied to the disposal of long-lived solid radioactive waste ICRP Publication 80Radiation Dose to Patients from Radiopharmaceuticals (Addendum to ICRP Publication 53) ICRP Publication 79Genetic Susceptibility to Cancer ICRP Publication 78Individual Monitoring for Internal Exposure of Workers (preface and glossary missing) ICRP Publication 77Radiological Protection Policy for the Disposal of Radioactive Waste ICRP Publication 76Protection from Potential Exposures - Application to Selected Radiation Sources ICRP Publication 75General Principles for the Radiation Protection of Workers ICRP Publication 74Conversion Coefficients for use in Radiological Protection against External Radiation ICRP Publication 73Radiological Protection and Safety in Medicine ICRP CD1Database of Dose Coefficients: Workers and Members of the Public ICRP Publication 72 Age-dependent Doses to the Members of the Public from Intake of Radionuclides - Part 5 Compilation of Ingestion and Inhalation Coefficients ICRP Publication 71 Age-dependent Doses to Members of the Public from Intake of Radionuclides - Part 4 Inhalation Dose Coefficients ICRP Publication 70Basic Anatomical & Physiological Data for use in Radiological Protection - The Skeleton ICRP Publication 69 Age-dependent Doses to Members of the Public from Intake of Radionuclides - Part 3 Ingestion Dose Coefficients ICRP Publication 68Dose Coefficients for Intakes of Radionuclides by Workers ICRP Publication 67 Age-dependent Doses to Members of the Public from Intake of Radionuclides - Part 2 Ingestion Dose Coefficients 33

34. IAEA ICRP Publication 66Human Respiratory Tract Model for Radiological Protection ICRP Publication 65Protection Against Radon-222 at Home and at Work ICRP Publication 64Protection from Potential Exposure - A Conceptual Framework ICRP Publication 63Principles for Intervention for Protection of the Public in a Radiological Emergency ICRP Publication 62Radiological Protection in Biomedical Research ICRP Supporting Guidance 1Risks Associated with Ionising Radiations ICRP Publication 61Annuals Limits on Intake of Radionuclides by Workers Based on the 1990 Recommendations ICRP Publication 601990 Recommendations of the International Commission on Radiological Protection ICRP Publication 59The Biological Basis for Dose Limitation in the Skin ICRP Publication 58RBE for Deterministic Effects ICRP Publication 57Radiological Protection of the Worker in Medicine and Dentistry ICRP Publication 56Age-dependent Doses to Members of the Public from Intake of Radionuclides - Part 1 ICRP Publication 55Optimization and Decision Making in Radiological Protection ICRP Publication 54Individual Monitoring for Intakes of Radionuclides by Workers ICRP Publication 53Radiation Dose to Patients from Radiopharmaceuticals ICRP Publication 52Protection of the Patient in Nuclear Medicine (and Statement from the 1987 Como Meeting of ICRP) ICRP Publication 51Data for Use in Protection against External Radiation ICRP Publication 50Lung Cancer Risk from Exposures to Radon Daughters ICRP Publication 49Developmental Effects of Irradiation on the Brain of the Embryo and Fetus ICRP Publication 48The Metabolism of Plutonium and Related Elements ICRP Publication 47Radiation Protection of Workers in Mines ICRP Publication 46Principles for the Disposal of Solid Radioactive Waste ICRP Publication 45Developing a Unified Index of Harm ICRP Publication 44Protection of the Patient in Radiation Therapy ICRP Publication 43Principles of Monitoring for the Radiation Protection of the Population ICRP Publication 42A Compilation of the Major Concepts and Quantities in Use by ICRP 34

35. IAEA ICRP Publication 41Nonstochastic Effects of Ionizing Radiation ICRP Publication 40Statement from the 1984 Meeting of the ICRP ICRP Publication 39Principles for Limiting Exposure of the Public to Natural Sources of Radiation ICRP Publication 38Radionuclide Transformations - Energy and Intensity of Emissions ICRP Publication 37Cost-Benefit Analysis in the Optimization of Radiation Protection ICRP Publication 36Protection against Ionizing Radiation in the Teaching of Science ICRP Publication 35General Principles of Monitoring for Radiation Protection of Workers ICRP Publication 34Protection of the Patient in Diagnostic Radiology ICRP Publication 33Protection against Ionizing Radiation from External Sources Used in Medicine ICRP Publication 32Limits for Inhalation of Radon Daughters by Workers ICRP Publication 31Biological Effects of Inhaled Radionuclides ICRP Publication 30 (Supplement B to Part 3)Limits for Intakes of Radionuclides by Workers ICRP Publication 30 (Supplement A to Part 3)Limits for Intakes of Radionuclides by Workers ICRP Publication 30 (Supplement to Part 2)Limits for Intakes of Radionuclides by Workers ICRP Publication 30 (Supplement to Part 1)Limits for Intakes of Radionuclides by Workers ICRP Publication 30 (Part 4)Limits for Intakes of Radionuclides by Workers: An Addendum ICRP Publication 30 (Part 3)Limits for Intakes of Radionuclides by Workers ICRP Publication 30 (Part 2)Limits for Intakes of Radionuclides by Workers ICRP Publication 30 (Part 1)Limits for Intakes of Radionuclides by Workers ICRP Publication 30 (Index)Limits for Intakes of Radionuclides by Workers ICRP Publication 29Radionuclide Release into the Environment - Assessment of Doses to Man ICRP Publication 28Principles for Handling Emergency and Accidental Exposures of Workers ICRP Publication 27Problems Involved in Developing an Index of Harm ICRP Publication 26Recommendations of the ICRP 35

36. IAEA 36

37. IAEA The 2007 Recommendations of the International Commission on Radiological Protection, ICRP Publication 103, Ann. ICRP 37 (2-4), 2007 Environmental Protection - the Concept and Use of Reference Animals and Plants, ICRP Publication 108, Ann. ICRP 38 (4-6), 2008 Environmental Protection: Transfer Parameters for Reference Animals and Plants, ICRP Publication 114, Ann. ICRP 39 (6), 2009 Cost-benefit analysis in the optimisation of radiation protection. ICRP Publication 37. 1983 Optimisation and decision-making in radiological protection. ICRP Publication 55. 1989 The 1990 Recommendations of the International Commission on Radiological Protection. ICRP Publication 60. Assessing dose of the representative person for the purpose of radiation protection of the public and The optimisation of radiological protection: Broadening the process. ICRP Publication 101. 2006 http://www.icrp.org/index.asp Further information 37