.This report contains the collective views of an international group of experts and does not necessarily represent the decisions or the stated policy of either the World Health Organization, the United Nations Environment Programme, the International Radiation Protection As- ociation, Environmental Health Criteria 16 RADIOFREQUENCY AND MICROWAVES Published under the joint sponsorship of the United Nations Environment Programme, the World Health Organization and the international Radiation Protection kssociation /o V4 o cy World Health Organization 4k Geneva, 1981 ISBN 924 1540761 © World Health Organization 1981 Publications of the World Health Organization enjoy copyright protec- tion in accordance with the provisions of Protocol 2 of the Universal Copy- right Convention. For rights of reproduction or translation of WHO publi- cations, in part or in toto, application should be made to the Office of Publications, World Health Organization, Geneva, Switzerland. The World Health Organization welcomes such applications. The designations employed and the presentation of the material In this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the World Health Organization concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or of certain manufacturers' products does not imply that they are endorsed or recommended by the World Health Organization in preference to others of a similar nature that are not men- tioned. Errors and omissions excepted, the names of proprietary products are distinguished by initial capital letters. PRINTED IN FINLAND 80/4729 - VAMMALA - 7000 CONTENTS ENVIRONMENTAL HEALTH CRITERIA FOR RADIOFREQUENCY AND MICROWAVES ..............................................8 1. SUMMARY AND RECOMMENDATIONS FOR FURTHER STUDIES...................................................... 10 1.1 Summary ................................................ 10 1.1.1 Physical characteristics in relation to biological effects 10 1.1.2 Sources and control of exposure ...................... 11 1.1.3 Biological effects in experimental animals ............ 12 1.1.4 Power density ranges in relation to health effects ... 13 1.1.5 Exposure effects in man ............................ 13 1.1.6 Health risk evaluation as a basis for exposure limits 14 1.2 Recommendations for further studies, exposure limits, and protective measures ...................................... 14 1.2.1 General recommendations ............................ 14 1.2.2 Measurement techniques ............................ 15 1.2.3 Safety procedures .................................... 15 1,2.4 Biological investigations ............................ 16 1.2.5 Epidemiological investigations ........................ 16 1,2.6 Exposure limits and emission standards .............. 17 1.2.6.1 Occupational exposure limits .................. 17 1.2.6.2 Exposure limits for the general population . 17 1.2.6.3 Emission standards .......................... 17 1.2.6.4 Implementation of standards .................. 17 1.2.6.5 Other protective measures .................... 18 1.2.6.6 Studies related to the establishment of limits 18 2. MAGNITUDE OF EXPOSURE TO MICROWAVE AND RF RADIATION AND SOURCES OF CONCERN .................. 18 3. PROPERTIES OF MICROWAVE AND RADIOFREQUENCY (RF) RADIATION .................................................. 19 3.1 Units of radiation ........................................ 21 3.2 Other physical considerations .............................. 22 4. SOURCES AND CONDITIONS OF EXPOSURE ................23 4.1 Natural background sources ................................ 23 4.2 Man-made sources ........................................ 25 4.2.1 Deliberate emitters .................................. 25 4.2.2 Sources of unintentional radiation ................... 32 4.3 Estimating exposure levels ................................ 35 4.3.1 Far-field exposure .................................. 35 4.3.2 Near-field exposure .................................. 35 4.4 Facilities for controlled exposure .......................... 36 4.4.1 Free space standard field method .................... 37 4.4.2 Guided wave methods ................................ 38 4.4.3 Standard probe method .............................. 39 5. MEASURING INSTRUMENTS ..................................40 5.1 General principles ........................................40 5.2 Types of instruments in common use ......................41 3 5.2.1 Diode rectifier 41 5.2.2 Bolometer ..........................................41 5.2.3 Thermocouple ......................................42 MICROWAVE AND RF ENERGY ABSORPTION IN BIOLOGICAL SYSTEMS....................................................42 6.1 Methods of computation ..................................43 -. 6.2 Experimental methods ....................................43 6.3 Energy absorption ........................................44 6.4 Molecular absorption ......................................48 BIOLOGICAL EFFECTS IN EXPERIMENTAL ANIMALS ......49 7.1 Hyperthermia and gross thermal effects .....................50 7.2 Effects on the eye .........................................54 7.3 Neuroendocrine effects .....................................58 7.4 Nervous system and behavioural effects .................... 62 7.5 Effects on the blood forming and immunocompetent cell sys- tems...................................................... 70 7.6 Genetic and other effects in cell systems .................. 73 7.7 Effects on reproduction and development .................. 76 HEALTH EFFECTS IN MAN .................................. 79 8.1 Effects of occupational exposure .......................... 80 8.1.1 Effects on the eyes .................................. 82 8.1.2 Effects on reproduction and genetic effects .......... 82 8.1.3 Cardiovascular effects .............................. 82 8.2 Medical exposure .......................................... 83 9. RATIONALES FOR MICROWAVE AND HF RADIATION PROTECTION STANDARDS .................................. 83 9.1 Principles ................................................ 83 -. 9.2 Group I standards ........................................ 84 9.3 Group 2 standards ........................................ 85 9.4 Group 3 standards ........................................ 90 9.5 RF radiation standards (100 kHz to 300 MHz) .............. 93 SAFETY PROCEDURES FOR OCCUPATIONALLY EXPOSED PERSONNEL .................................................. 102 10.1 Procedures for reducing occupational exposure .............. 102 ASSESSMENT OF DATA ON BIOLOGICAL EFFECTS AND RECOMMENDED EXPOSURE LIMITS ........................ 104 REFERENCES .................................................... 106 GLOSSARY...................................................... 126 ANNEX.......................................................... 133 4 NOTE TO READERS OF THE CRITERIA DOCUMENTS While every effort has been made to present information in the criteria documents as accurately as possible without unduly delaying their publication, mistakes might have occurred and are likely to occur in the future. In the interest of all users of the environmental health criteria documents, readers are kindly requested to com- municate any errors found to the Division of Environmental Health, World Health Organization, Geneva, Switzerland, in order that they may be included in corrigenda which will appear in subsequent volumes. In addition, experts in any particular field dealt with in the criteria documents are kindly requested to make available to the WHO Secretariat any important published information that may have inadvertently been omitted and which may change the evalua- tion of health risks from exposure to the environmental agent under examination, so that the information may be considered in the event of updating and re-evaluation of the conclusions contained in the criteria documents. WHO/IRPA TASK GROUP ON ENVIRONMENTAL HEALTH CRITERIA FOR RADIOFREQUENCY AND MICROWAVES Members Dr V. Akimenko, A. N. Marzeev Institute of General and Communal Hygiene, Kiev, USSR Professor P. Czerski, National Research Institute of Mother and Child, Warsaw, Poland (Ropportenr)e Mme A. Duchêne, Département de Protection, Centre dEtudes nucleaires, Fontenay.-aux-Roses, France a Dr M. Faber, Finsen Institute, Finsen Laboratory, Copenhagen, Denmark ' Professor M. Grandolfo, Radiation Laboratory, Higher Institute of Health, Rome, Italy Mr F. Harlen, National Radiological Protection Board, Harwell, England Dr H. Jammet, Departement de Protection, Centre dEtudes nucléaires, Fontenay-aux-Roses, France a Dr J. Kupfer, Central Institute for Occupational Medicine of the GDR, Berlin, German Democratic Republic (Vice-Chairman) Dr M. Repacholi, Health Protection Branch, Department of National Healti'. and Welfare, Ottawa, Canada a Dr B. Servantie, E,A.S.S.M, Centre d'Etudes et de Recherche de Bio- physiologie, Toulon Naval, France Dr M. Shore, Bureau of Radiological Health, Food and Drug Administra- tion, Department of Health, Education and Welfare, Rockville, MD, USA (Chairman) Representatives of other Organizations Mr H. Ponliquen, International Telecommunications Union, Geneva, Swit- zerland Or G. Verfaillie, Commission of European Communities, Brussels, Belgium Secretariat Mr S. Fluss, Health and Biomedical Information Programme, WHO, Ge- neva, Switzerland Dr E. Komarov, Environmental Health Criteria and Standards,