IAEA-TECDOC-870 Methods for estimating the probability cancerof from occupational radiation exposure () INTERNATIONAL ATOMIC ENERGY AGENC\ /A Y The IAEA does not normally maintain stocks of reports in this series. However, microfiche copie f thesso e reportobtainee b n sca d from INIS Clearinghouse International Atomic Energy Agency Wagramerstrasse5 0 10 x Bo . P.O A-1400 Vienna, Austria Orders should be accompanied by prepayment of Austrian Schillings 100, for e for e chequ th a f m IAEth f mo n i o n i r Aeo microfiche service coupons orderee whicb y hdma separately fro INIe mth S Clearinghouse. originatine Th g Sectio thif no s publicatio IAEe th An i was: Radiation Safety Section International Atomic Energy Agency Wagramerstrasse 5 0 10 P.Ox Bo . A-1400 Vienna, Austria METHOD ESTIMATINR SFO PROBABILITE GTH CANCEF YO R FROM OCCUPATIONAL RADIATION EXPOSURE IAEA, VIENNA, 1996 IAEA-TECDOC-870 ISSN 1011^289 ©IAEA, 1996 Printe IAEe th AustriAn y i d b a April 1996 INTERNATIONAL ATOMIC ENERGY AGENCY WAGRAMERSTRASSE 5, P.O. BOX 100, A-1400 VIENNA (AUSTRIA) Telephone: 4431 2060 Telex: 112645 ATO MA Facsimile : +431 20607 e ReaderTth o , This IAEA-TECDOC has been prepared for informatio d assistancan n n i e establishment and use of national registries for actinide elements in humans y proposalAn . r commento s s that might help in updating this report would be most welcome. Radiation Safety Section [[email protected]] FOREWORD The IAEA is aware that a few Member States, with well developed nuclear programmes, have initiate developed dan d scheme compensato t s e those worker r thei(o s r relatives whon )i m cance havy rma e arisen fro exposure mth radiatioo et t workna . Mosf o t the Member States have howeve t developeye t rno d similar schemes. TechnicaA l Committee meetin s hel n Julwa gi d y 199 o provid5t e information regarding experienc techniqued an n eo r makinfo s g quantitative estimates concernine gth probability of causation of cancer as a function of occupational radiation exposure and the method f calculatino s d estimatinan g g whether occupational exposur n individuaa f o e l suffering from cancer coul hele db d responsibl patient'e th r efo s condition. particulacasa e I nf th eo r cance specifia n i r c individua s generalli t i l y accepten di existing schemes that compensation of a claimant who has worked with sources of ionizing radiation is appropriate if the probability of induction of this cancer from occupational radiation exposure is greater than the chance of induction by all other causes, including natural and medical radiation exposure. This publication discusses methods for assessing the probability of causation of cancer from occupational exposure taking into account a number of complex factors such as cumulative dose and duration of occupational exposure, dose rate, t tima f diagnosie eo ag f cancerso , localizatio typd f cancenan eo r induced. The participatio l memberal Technicaf e no th f so l Committee meetin draftinn gi e gth repor appreciateds i t majoe Th . r contributio J.Rf no . Harriso preparatioe n th (NRPB n i ) ,UK n of this repor especialls i t y acknowledged. The Scientific Secretary responsible for the co-ordination of the meeting and the preparatio f thino s publicatio Divisio. e TuraI th s f o in wa f Radiatio no Wastd nan e Safety. EDITORIAL NOTE In preparing this publication for press, staff of the IAEA have made up the pages from the original manuscripts). viewsThe expressed necessarilynot do reflect those governments ofthe ofthe nominating Member nominating the States of or organizations. Throughout textthe names of Member States retainedare theyas were when textthe was compiled. Theof use particular designations countriesof territoriesor does imply judgementnot any publisher,bythe legalthe IAEA,to statusthe as of such countries territories,or of their authorities and institutions or of the delimitation of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does imply intentionnot any infringeto proprietary rights, should construednor be it as an endorsement or recommendation on the part of the IAEA. CONTENTS 1. INTRODUCTION .............................................. 7 1.1. Background ............................................... 7 1.2. Objective ................................................. 7 1.3. Scope ................................................... 7 1.4. Application, structure ........................................7 . 2. AETIOLOGY OF CANCER ....................................... 8 2.1. Introduction ............................................... 8 2.2. Stages in cancer development ................................... 8 2.3. Factors causing cancer .......................................8 . 2.4. Interactio carcinogenif no othed can r factors ........................0 1 . 3. RADIATION AS A CAUSE OF CANCER ............................ 11 3.1. Ionizing radiation ........................................... 11 3.2. The cell target ............................................. 12 3.3. Stochastic effects ..........................................3 1 . 3.4. Evidenc radiatioe th r efo n inductio cancef no r ......................3 1 . 3.5. Risk estimates ............................................. 13 3.6. Factors influencing radiosensitivit modificatiod yan f effectno f o s exposure by other factors ...................................... 14 4. CHOICE OF RISK MODELS ...................................... 15 4.1. Introduction ............................................... 15 4.2. Effect of age at exposure and time since exposure on site specific cancer risk ................................................ 15 4.3. Effec dosf dosd o t ean e rate sitn so e specific cancer risk ...............6 1 . 4.4. Consequences of choice of model for PC calculations .................. 17 4.5. Latent periods .............................................. 17 4.6sitn o e. x specifiEffecse f o t c cancer risk ..........................8 1 . 4.7. Transfe risf o rk estimates between populations ......................8 1 . 5. PROBABILIT CAUSATIOF YO N .................................0 .2 5.1. Definition ................................................. 20 5.2. Limitations ................................................ 21 expressioe 5.3Th .probabilite th f no causatiof yo multiplr nfo e exposures ......2 .2 6. SOURCE UNCERTAINTF SO Y ...................................3 .2 6.1. Introduction ..............................................3 .2 6.2. Epidemiology .............................................3 .2 6.3. Extrapolations .............................................. 23 6.4. Dosimetry ................................................ 24 6.5. Average radiosensitivity ....................................... 24 6.6. Sex ..................................................... 25 6.7. Contributio othef no r carcinogenes ..............................5 2 . 6.8. Type of radiation ........................................... 25 7. EXAMPLES OF PC CALCULATIONS ............................... 25 8. SUMMARY .................................................. 35 APPENDIX I. FACTORS AFFECTING CANCER RISK .................... 37 APPENDIX H. RISK MODELS ...................................... 43 REFERENCES .................................................7 .4 ABBREVIATIONS ..............................................4 5 . CONTRIBUTOR DRAFTINO ST REVIED GAN W ........................5 .5 . INTRODUCTIO1 N 1.1. BACKGROUND With increasing public awareness of the presumed risk of harm to health attributable to us f nucleaeo r energy, therincreasinn a s ei g numbe f claimro r compensatiosfo workery nb s (or their relatives whon i ) m cance havy ma re arisen fro exposure mth radiatioo et t workna . A Technical Committe formes ewa examino dt e whethe IAEn ra A Technical Document could provide guidanc Membeo et r methode State th employe e n b so o t s calculato dt e eth probability that any particular cancer might be attributed to an occupational exposure to radiation. 1.2. OBJECTIVE aime f thiTh so s TECDO preseno t e factorCe ar th t s whic generalle har y acceptes da being responsible for cancer induction, to examine the role of radiation as a carcinogen, to demonstrat probabilite th w eho f canceyo r causatio radiatioy ncalculateb e b y o t nma d dan infor readee uncertaintiee mth th f ro s thaassociatee ar t variouf o e d us wit se rishth k factors and models in such calculations. 1.3. SCOPE This report considers only cancer induction and does not include other stochastic effects, such as hereditary disorders, or deterministic effects, such as cataract formation. It relates only to occupational radiation exposures. It does not include medical exposures, exposures in utero, o embryot r fetuseo s f femalo s e radiation workers, doses from high natural background radiation, doses received from environmental exposures caused by industrial processes r exposureo , non-ionizino st g radiation. 1.4. APPLICATION, STRUCTURE This report is intended for general guidance only. It outlines an approach to develop national procedures for calculating attributability when cancer cases arise in radiation workers who may be seeking compensation. It is not intended to be an authoritative reference on the Membeo t d ai subjecn ra Statet bu tr consideratio sfo probabilitf no f occupationayo l cancer induction specifiy an n I c. applicatio dato mosappropriate d t nth ep an u t e risk factors and, where appropriate, national cancer incidence rates should