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From IEEE RF Safety Standard to Address Base Station and Mobile Phone Safety Concerns

From IEEE RF Safety Standard to Address Base Station and Mobile Phone Safety Concerns C-K. Chou, Ph.D. Chairman, Technical Committee 95 International Committee on Electromagnetic Safety I nstitute of E lectrical and E lectronics Engineers Piscataway, New Jersey USA. Outline.

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From IEEE RF Safety Standard to Address Base Station and Mobile Phone Safety Concerns

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  1. From IEEE RF Safety Standard to Address Base Station and Mobile Phone Safety Concerns C-K. Chou, Ph.D. Chairman, Technical Committee 95 International Committee on Electromagnetic Safety Institute of Electrical and Electronics Engineers Piscataway, New Jersey USA

  2. Outline • IEEE RF Safety Standard • RFSafety Research Trend • Ionizing vs Non-ionizing Radiation • Biological Complexity • Engineering Complexity • Research Update • Standards Update • Conclusions

  3. IEEE RF Safety Standard History 1960: USASI C95 Radiation Hazards Project and Committee chartered 1966: USAS C95.1-1966 • 10 mW/cm2 (10 MHz to 100 GHz) • based on simple thermal model 1974: ANSI C95.1-1974 (limits for E2 and H2) 1982: ANSI C95.1-1982 (incorporated dosimetry) 1991: IEEE C95.1-1991 (two tiers – reaffirmed 1997) 2006: IEEE C95.1-2005 published on April 19, 2006 (comprehensive revision, 250 pages, 1143 ref.)

  4. International Committee on Electromagnetic Safety TC95 Subcommittee 4: 132 members, 42% from outside the US representing the following 23 countries: Australia 4 Italy 3 Bulgaria 2 Japan 3 Canada 4 Korea 2 China 3 Netherlands 2 Finland 3 New Zealand 1 France 1 Poland 2 Germany 1 Slovenia 1 Greece 3 South Africa 2 Hungary 1 Sweden 1 Ireland 3 Switzerland 3 Israel 2 Thailand 1 United Kingdom 8

  5. International Committee on Electromagnetic Safety SC4 Membership Composition

  6. SC4 Task for Revision • C95.1-1991 needs a complete revision • ICES is committed to the development of a science-based RF safety standard that is protective of public health, unambiguous, and practical to implement • The RF standard should be harmonized with other international standards to the extent where scientifically defensible

  7. Extensive Database • The biological effects of RF exposure have been studied for more than 50 years. • The WHO EMF Project website (http://www.who.int/peh-emf/en/) contains more than 2500 entries, of which more than 1400 are relevant to health effects of RF exposure. • At the close of the evaluation by ICES, 1143 studies were listed in the references.

  8. C95.1-2005: Definitions Weight of evidence: For purposes of this standard, the outcome of assessing the published information about the biological and health effects from exposure to RF energy. This process includes evaluation of thequality of test methods, thesizeandpowerof the study designs, theconsistencyof results across studies, and thebiological plausibilityofdose-responserelationships andstatistical associations.

  9. C95.1 Standard’s major revision • A notable revision to the new standard is the recommendation of peak spatial average SAR of 2 and 10 W/kg averaged over 10 g tissue for the lower and upper tier, respectively. • This revision resolves a major harmonization issue with RF standards.

  10. RF Safety Concerns RF Source (years)Body Exposure • Radar (50-60’s) Whole body • Broadcasting (60-70’s) Whole body • Microwave Oven (70-80’s) Localized • Police Radar (80’s) Localized • Mobile Communication (90’s - ?) • Two-way radios (since 60’s) Localized • Mobile phones Localized • Base stations Whole body

  11. Ionizing vs. Non-Ionizing Energy • Ionizing • Sufficient energy to alter chemical bonds and atomic structure • Confirmed health effects include genetic damage • Effects can occur from cumulative exposure • Non-ionizing (including RF) • Lower energy, insufficient to cause effects like those above • Only confirmed RF health effects relate to tissue heating at levels well above limits • No known chronic/cumulative effects

  12. Biological Complexity • In vivo study • Species • Strain • Sex • Age • Extrapolation from animal to humans • In vitro study • Monolayer • Cell suspension • Isolated tissue • Extrapolation to human beings

  13. Cataract study

  14. Ophthalmologist looking for cataract

  15. Microwave induced Cataract In a rabbit eye

  16. Facial burns but no cataract

  17. Engineering Complexity • Far Field Exposure • Near Field Exposure • RF Dosimetry • Resonance • Modulation • CW, Pulsed • AM, FM, TDMA, CDMA • Experimental Artifacts • Temperature Control

  18. Health policy must be science based • A single study can form the basis of an hypothesis, but does not provide the basis for hazard identification. • Confirmation of the results of any study is needed through replication and/or supportive studies. • The resulting body of evidence forms the basis for science-based judgments by defining exposure levels for • adverse health effects • no observable adverse effects

  19. Study Type Strengths and Weaknesses • Epidemiological studies:Greatest weighting (WHO, IARC) • Distribution of disease in a population and factors affecting this • BUT can be subject to bias and confounding • Volunteer studies: • Response of people to an agent such as RF • BUT short-term exposure and selection (of healthy volunteers) • Animal studies: • Responses of mammals to an agent such as RF • BUT differences in metabolism, physiology, lifespan, etc • In Vitro Cell studies: Least weighting • Rapid cheap screening for possible interaction mechanisms • BUT simple systems, may not be applicable to a whole organism

  20. RFBioeffects: Peer Reviewed Publications Since 1950

  21. Mobile Telephony Related Studies

  22. WHO Comment on Database • scientific knowledge in this area is now more extensive than for most chemicals. • WHO concluded that current evidence does not confirm the existence of any health consequences from exposure to low level electromagnetic fields. http://www.who.int/peh-emf/about/WhatisEMF/en/index1.html

  23. New RF Research Programs WHO estimated $250 M already spent on mobile telephony bioeffect research

  24. General Conclusion from Epi studies • To date, epidemiological studies do not provide guidance for the study of low-level non-thermal effects and as a whole do not suggest the existence of low-level effects.

  25. Summary: Animal Cancer • The weight of scientific evidence in 41 studies shows that RF exposure up to lifetime exposure (2 years) does not adversely affect carcinogenic processes (initiation, promotion or co-promotion) at • whole-body dose rates up to 4 W/kg and • localized dose rates up to 2.3 W/kg. • Long term animal studies provide no supportive evidence of low-level non-thermal effects.

  26. UK MTHR program (2007) • The conclusion so far from the data obtained within the MTHR programme is that there is no evidence of effects. However, the question remains of the nature of the mechanism of effects due to chronic exposure, if they exist. MTHR: Mobile Telephony Health Research

  27. WHO on Children’s Exposure (2005) “Present scientific evidence does not indicate the need for any special precautions for the use of mobile phones.. If individuals are concerned, they might choose to limit their own or their children's RF exposure by limiting the length of calls, or by using ‘hands-free’ devices…” http://www.who.int/emf

  28. Expert Scientific Reviews (1996-2007) • Australian Committee on EM Energy Public Health Issues • European Commission Expert Group • European Committee on Toxicology, Eco-toxicology • French Environmental Health and Safety Agency (AFSSE) • Health Council of the Netherlands • Hong Kong - Office of the Telecommunications Authority • International Commission on Non-Ionizing Radiation Protection (ICNIRP) • International Radiation Protection Association (IRPA) • Japanese Ministry of Post and Telecommunications • New Zealand Ministry of Health and Ministry of Environment • Nordic Authorities (Denmark, Finland, Iceland, Norway and Sweden) • Royal Society of Canada Expert Panel and Health Canada • Singapore Health Sciences Authority • Swedish State Radiation Protection Authority • U.K. Advisory Group of Non Ionizing Radiation • U.K. Independent Expert Group on Mobile Phones (Stewart Report) • U.K. National Radiological Protection Board • U.S. Food and Drug Administration • World Health Organization

  29. General Conclusion of Expert Scientific Reviews • No credible evidence that RF exposures within internationally accepted limits cause any adverse health effects, but… • More research is needed …… Remarks • One can never prove the null hypothesis and thus one can never prove that something is absolutely safe. • There is no known mechanism for adverse health effects of RF exposure other than thermal. • Due to the current extensive database, it is unlikely that results of ongoing studies will shift the weight of evidence on health effects. Page 2

  30. Future Important Reviews • International Agency for Research on Cancer, RF Review – late 2008 • Classification of the carcinogenic potential of RF exposure • WHO RF Environmental Health Criteria – 2009 • Assessment of all health endpoints

  31. Differences between Science and Media

  32. Problems in Media Communication • Media reports on EME issues often are not verified and reviewed • Statements from so called “Experts” • Sensationalism • Misinformation propagates fast and continuously • Corrections do not make the news • General public acquire knowledge from media and NOT from scientific journals

  33. Three Types of RF standards • Exposure Safety Standards • IEEE ICES TC95  International Commission on Non-Ionizing Radiation Protection (ICNIRP) • Emission Assessment Standards • IEEE IECS TC34  International Electrotechnical Commission (IEC) TC106 • Safety Related Compatibility Standards

  34. New IEEE Std. C95.1-2005 pp 1-250

  35. Phone reference marks

  36. RF Product Compliance For mobile phone or two-way radio Peak SAR determination

  37. Densitometry Measure power density in mW/cm2 or μW/cm2 with a survey meter Compare with Reference Limits or MPE

  38. Cellular Transmission Towers 20 Channels 10 Watts/Channel Distance from 3 m 15 m 30 m 124 m 300 m transmission source Power density .00004 mW .00006 mW .00004 mW .00002 mW .00013 mWper square centimeter* Number of times below 13,750 9,167 13,750 27,500 4,230internationally recognizedsafety standards** 40 m *1 milliwatt (mW) = 1/1,000 watt **The ANSI/IEEE and NCRP safety standards for the general public in theenvironment depicted above are .550 milliwatts per square centimeter

  39. Rooftop Antennas 10% Exposure Limit 1% Exposure Limit Residential and office building RF exposures are in general lower than 1% of ICNIRP or IEEE limits, similar to radio and TV broadcast exposure level. Rooftop antenna installation is safe.

  40. WHO Fact Sheet #304 (May 2006) Electromagnetic fields and public health: Base stations and wireless technologies Considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects. http://www.who.int/mediacentre/factsheets/fs304/en/index.html

  41. Conclusions • RF electromagnetic waves are not nuclear radiation • Only proven RF adverse effect is thermal effect • Exposure levels near base stations are very low • Both ICNIRP and IEEE standards provide ample protection for all populations

  42. Thank you

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