350 likes | 553 Vues
Wireless Communications & Health in the USA: issues, regulatory policies & research. International Scientific Workshop on Health Aspects of Mobile Telephony, Brussels 29-30 October 2001. Members of US delegation. Robert Cleveland, Ph.D. Senior Scientist, Federal Communications Commission
E N D
Wireless Communications & Health in the USA: issues, regulatory policies & research International Scientific Workshop on Health Aspects of Mobile Telephony, Brussels 29-30 October 2001
Members of US delegation • Robert Cleveland, Ph.D. • Senior Scientist, Federal Communications Commission • C.K. Chou, Ph.D. • Chief EME Scientist, Motorola Florida Research Laboratories • Jerrold Bushberg, Ph.D. • Clinical Professor, School of Medicine, Univ. of California, Davis • Joe Elder, Ph.D. • Director, Biological Research, Motorola Florida Research Laboratories • James Lin, Ph.D. • Professor, Elec.Engineering & Bioengineering, Univ. of Illinois, Chicago • Russell Owen, Ph.D. • Chief, Radiation Biology Branch, Food & Drug Admin. (CDRH)
Topics to be addressed • Public concern • Regulations and jurisdiction • Policy development • Research • Consumer outreach & education • Risk assessment
Health/safety issues have been raised for both phones and base stations
Some sources of controversy • Media reports • Conflicting scientific reports • Lack of confidence in RF standards • Fear of “radiation” • Differences in RF safety standards between countries
Issues in experimental science • RF dosimetry is complicated • Many effects not repeatable but still cause concern • Inadequate attention to engineering and biological details in experiments • Positive effects that are later proven to be artifacts
Concern in USA over potential RF health effects from mobile phones US General Accounting Office (GAO) asked by US Congress to prepare report on mobile phone safety Final GAO report (May 2001) concluded: No evidence of adverse health effects to date However cannot conclude no risk No definitive answers likely for some time FCC & FDA provide better information to consumers Measurement standard needed for phone SAR
US Federal Communications Commission & US Food and Drug Administration • FCC & FDA share regulatory jurisdiction for wireless communications safety • FCC adopted revised RF exposure guidelines in 1996 • apply to both fixed & mobile/portable transmitters • FDA jurisdiction emphasizes radiation emissions from consumer/industrial products (ionizing, RF, UV, etc) • Center for Devices & Radiological Health (CDRH) • FDA RF standard: microwave ovens • FCC, FDA & other US health/regulatory agencies are members of an inter-agency RF working group
RF exposure standards • International Commission on Non-Ionizing Radiation Protection (ICNIRP) • Institute of Electrical and Electronics Engineers (IEEE) • National Council on Radiation Protection and Measurements (NCRP) • FCC (USA) guidelines based on NCRP & IEEE • Also, US military uses IEEE standard
FCC regulatory policy • FCC not a health/safety agency but must comply with National Environmental Policy Act • FCC relies on expert organizations & agencies for guidance on health/safety issues • Guidelines adopted after extensive public comment • Guidelines endorsed by US Government health/safety agencies: FDA, EPA, NIOSH, OSHA • Rule citations: Title 47, US Code of Federal Regulations, Sections 1.1307(b), 1.1310, 2.1091, 2.1093
Exposure guidelines based on Specific Absorption Rate (SAR) • SAR = rate energy absorbed per unit mass • Units: watts/kg (W/kg) or milliwatts/gm (mW/g) • IEEE, NCRP & ICNIRP all identify 4 W/kg as threshold for potentially harmful effects • Limits for localized exposure, field strength & power density all traceable to this value
Scientific basis for standards • Science-based standards (all effects considered) • Thermal effects • Shocks, burns, and resulting tissue damage • Non-thermal effects not found hazardous • Threshold for potential harm: • 4 W/kg (whole-body) • Based on behavioral changes in animals • Basis for IEEE, ICNIRP, NCRP exposure limits
RF exposure standards for mobile telephones • USA: FCC uses IEEE limit of 1.6 W/kg averaged over one gram of tissue • Other countries using 1.6 W/kg include Canada, Korea & Australia • Some countries (example China) considering other • Europe: many countries adopting ICNIRP limit of 2.0 W/kg averaged over 10 grams of tissue • ICNIRP limit less conservative than IEEE limit
FCC regulations • RF guidelines: 300 kHz-100 GHz • Technical documents providing techniques for evaluating exposure • OET Bulletin 65 + Supplements A, B & C • Mobile phone approval requires SAR test data • FCC will conduct compliance testing of mobile phones • FCC and FDA staff working with IEEE committees developing guidelines for exposure & measurements • Example, IEEE SCC34: developing recommended practice for measuring SAR from mobile phones
FDA activities • Radiation Control for Health & Safety Act of 1968 • Applies to radiation-emitting electronic products • Long term animal studies • Work with National Toxicology Program & other groups • Exposure assessment & test method development • Cellular and animal experiments on enzyme activity • Assessments and education
FDA cooperative research program • Cooperative Research and Development Agreement (CRADA) with the Cellular Telecommunications & Internet Association • FDA provides scientific and technical oversight • Three parts • Micronucleus assay • Epidemiology • Other topics
Resolving scientific questions about RF safety • No single piece of research can definitely answer any scientific question • Conclusions must be based on consensus drawn from cumulative evidence • Reports of effects must be subjected to appropriate scientific scrutiny
Development of science-based policy Must be based on scientific data Empirical evidence evaluated Sources of uncertainty identified Establish level of protection Exposure assessment and evaluation of measurement capabilities necessary
What can be provided by the scientific process? • Scientific approach prescriptive & predictive power • Establish effects which cause identifiable health problems • Dose response relations established • Threshold values established • Where possible identify mechanism of action
Science-based research needed for making policy decisions Goal is replication and consistency Need critical number of scientists working on a large number of projects Government and independent support and commitment needed Industrial sector can complement Government involvement important for general public acceptance
Science-based approach requires multiple projects Biological systems and organisms are complex Responses may vary for “similar” exposures Reproducibility & independently repeated studies required for evidence and statistical significance Repeatability and confirmation fundamental to the scientific approach
Research to date on mobile telephony and health • Approximately 300 studies, almost 200 completed • Vast majority show no effect - no consistent positive result suggests an adverse health effect • Need to understand basic mechanism causing any biological response to determine relevance to wireless technologies • Only RF effects in two main areas established: • Thermal effects of RF energy • Neurostimulation by RF fields and currents
Studies conducted in the US • About 300 studies worldwide related to mobile telephony • 80 studies ongoing or completed in US • All studies contribute to the total picture and should not be considered in isolation • Current major studies include: • Studies at Washington University • Battelle-Pacific National Laboratory • FDA/CTIA CRADA • Animal studies planned by US NTP (NIEHS) • US Air Force research
Recent expert scientific reviews • World Health Organization • International Commission on Non-Ionizing Radiation Protection • European Commission Expert Group • Royal Society of Canada Expert Group • U.K. National Radiological Protection Board • U.K. Independent Expert Group on Mobile Phones • French Expert Report • Spanish Expert Review • Common conclusion: No credible evidence that RF exposures within accepted limits cause adverse health effects
How is public opinion formed? • Media reports • Corrections to erroneous reports usually not subsequently reported • Statements from “experts” • Rumors and “word of mouth” • Note: members of the general public rarely read scientific journals
Sources for consumer outreach & education • Government agencies (FCC, FDA) • Industry (manufacturers, service providers) • Many now provide SAR & standards information • Trade associations (CTIA in USA) • CTIA-certified phones must provide SAR information • International organizations (WHO, ICNIRP) • Scientific organizations (BEMS) • Miscellaneous Web sites
FCC Internet Site for RF Safety:www.fcc.gov/oet/rfsafety • Frequently asked questions (“FAQs”) • Texts of FCC decisions • FCC publications on RF safety • SAR values for mobile phones available • Links to other Web sites • Also, dedicated telephone line for information: +1-202-418-2464
Joint FDA/FCC Web site on mobile phone safety Under Development
Public perception of risk • Fact: In general people & the press focus on bad news more than good news • Proposition: A single study showing an association between RF & an adverse health effect will not be easily offset by numerous studies failing to show an association
Public perception of risk • Consequence: As more research is performed it is more likely that there will be increased public concern, even if the majority of the studies fail to show any adverse health effects • Conclusion: In the Short Term, risk assessment studies tend to increase perceived risk - this does not mean don't do them, but rather be prepared for the result
Risk communication & educating the general public • Simplify technical information • Build trust in information sources • Independence & timeliness of information is important • Use appropriate analogies for risk • Explain the scientific process • Listen to what the public is saying & honestly address their concerns
What can we conclude? • RF biological research & dosimetry are complicated • Establishing health/safety standards based on research is even more complicated & requires judgement & assumptions in lieu of complete knowledge • In future: we will know more about what we question today but...we may also have new questions • While this is the very nature of scientific research…it can be, in fact, very counterintuitive to the general public