Historical Review of RF Exposure Standards and the International Committee on Electromagnetic Safety (ICES)

Transcription

1 Bioelectromagnetics Supplement 6:S7^S16 (2003) Historical Review of RF Exposure Standards and the International Committee on Electromagnetic Safety (ICES) John M. Osepchuk 1 and Ronald C. Petersen 2 * 1 Full Spectrum Consulting, Concord, Massachusetts 2 R. C. Peterson Associates LLC, Bedminster, NewJersey Focused research on the biological effects of exposure of humans and animals to radio frequency (RF) and microwave energy goes back at least five decades. The history of committees that develop safety standards based on the results of this research goes back almost as far. One such committee that has played a major role in developing such standards is the International Committee on Electromagnetic Safety (ICES), which began in 1960 as the American Standards Association C95 Committee. This paper briefly reviews the history of this committee and its role in the development of RF safety standards. The process now being followed by ICES and its sponsor, the IEEE Standards Association Standards Board (SASB), is discussed, as are a number of issues related to standards setting, such as the poor quality of much of the research and the seemingly endless speculation and search for mechanisms of interaction other than heating. Finally, a tribute is given to Dr. Eleanor Adair, a longtime researcher and supporter of science-based standards. As Chairman of ICES, she makes it clear that her goal and the goal of ICES is to establish rational standards that will make future beneficial applications of RF energy credible to humanity. Bioelectromagnetics Supplement 6:S7 S16, ß 2003 Wiley-Liss, Inc. Key words: radio frequency exposure; safety; SCC28; IEEE C95.1; standard development process; Adair, Eleanor HISTORY OF EM EXPOSURE STANDARDS ANSI/IEEE The results of studies of effects on animals and humans exposed to electromagnetic energy have appeared in the literature for well over a century. Focused research, however, particularly on the effects of exposure to RF energy in the microwave region, only began toward the end of World War II. The impetus was concern about exposure to the RF fields produced by radars, the power of which continued to increase during and after the war. During the 1950s, limits for exposure of personnel, mainly in occupational settings, were first proposed and applied. For example, in the United States a number of organizations proposed and adopted limits expressed in terms incident power density, which ranged from 1 W/m 2 (100 mw/cm 2 ) to 1000 W/m 2 (100 mw/cm 2 ). The former value was assumed to be safe under all conditions; exposure above the latter was considered hazardous [Mumford, 1960]. During the mid to late 1950s several important meetings were held to bring together interested parties to review the state of the science on the issue of microwave bioeffects. These included the 1955 Symposium on Physiologic and Pathologic Effects of Microwaves held at the Mayo Clinic, 1 The First Annual Tri-Service Conference on Biological Hazards of Microwave radiation (1957) and The Second Annual Tri-Services Conference on Biological Effects of Microwave Energy (1958) [Michaelson, 1971]. As new data became available, the widely differing safety limits began to converge to a value of 100 W/m 2 for continuous whole-body exposure, a value first recommended to the US Navy Department in 1953 by H. Schwan [Mumford, 1960]. This value, based on a simple thermal model to limit temperature rise, was supported by experimental data showing that the threshold for lens opacities, a biological endpoint of considerable interest at the time, was greater than 1 The papers presented at this meeting were published in IRE Trans Med Electronics, Vol. ME-4, February *Correspondence to: Ronald C. Petersen, PO Box 386, Bedminster, NJ r.c.petersen@ieee.org Received for review 4 September 2002; Final revision received 6 May 2003 DOI /bem Published online in Wiley InterScience ( ß 2003 Wiley-Liss, Inc.

2 S8 Osepchuk and Petersen 2 The IEEE is today the world s largest technical professional society with more than individual members, one-third from outside the US representing more than 150 countries. Within the IEEE are a number of professional societies that sponsor standards committees. Standards addressing subjects of interest to more than one society, e.g., RF safety standards, are developed by Standards Coordinating Committees sponsored by the IEEE- Standards Association Standards Board (SASB) W/m 2. The recommendations at the time usually applied to frequencies between 10 MHz and 100 GHz. The first formal standards project was initiated in 1960 when the American Standards Association (now the American National Standards Institute ANSI) approved the Radiation Hazards Standards Project. This project, under cosponsorship of the Department of the Navy and the Institute of Radio Engineers (now the Institute of Electrical and Electronics Engineers IEEE) included the establishment of Committee C95, which was charged with developing RF/microwave safety standards through an open consensus process. The C95 Committee published its first standard in 1966 [ASA, 1966]; revisions of the standard were published in 1974 [ANSI, 1974] and 1982 [ANSI, 1982]. Both the 1966 and 1974 standards were based on a simple thermal model, limiting the absorbed power to less than 100 W, a value comparable to the resting metabolic heating rate of an adult human. The recommended limit for whole-body exposure was still 100 W/m 2, but the 1974 standard also contained plane wave equivalent electric and magnetic field limits to account for near field exposures at frequencies below a few hundred MHz. The 100 W/m 2 value applied to continuous exposures. For short term exposures the limits were 10 mwh/m 2, based on an averaging time of 0.1 h, i.e., the limits are relaxed using simple timeaveraging rules for exposures shorter than the averaging time. One-tenth of an hour was considered the approximate thermal time constant of important organs such as the eyes and testes. The 1982 standard recognized the importance of dosimetry and was the first to base its limits on specific absorption rate (SAR the mass averaged energy absorption rate [NCRP, 1981]) for frequencies where SAR is valid, i.e., between about 100 khz and 6 GHz. Because SAR is frequency dependent, the limits are also frequency dependent. Like the 1966 and 1974 standards, the 1982 standard was single tier, i.e., the same limits applied in the workplace and for the public. In 1988, the C95 committee continued its work as Standards Coordinating Committee 28 (SCC28) under the sponsorship of the IEEE Standards Board (now the IEEE Standards Association Standards Board SASB). 2 The current standard, IEEE C [IEEE, 1999], recognizes the importance of electrostimulation at frequencies below and surface heating at frequencies above the SAR region. More realistic averaging time values at millimeter wave frequencies have been incorporated to preclude the possibility of skin burns for short exposures and limits for induced and contact current are also included. For the first time a C95.1 standard contained two tiers in the SAR region; but rather than define the exposed populations, the exposure environments were defined for each of the tiers, i.e., exposures in controlled and uncontrolled environments. Unlike many contemporary standards and guidelines, the C95.1 standard includes detailed rules for implementation and formal procedures for responding to requests for interpretation have been instituted. As described by Osepchuk and Petersen [2001], contemporary RF/microwave standards are based on the results of critical evaluations and interpretations of the relevant scientific literature. The SAR threshold for the most sensitive effect considered potentially harmful to humans, regardless of the nature of the interaction mechanism, is used as the basis of the standard. To account for uncertainties in the data and to increase confidence that the limits are below levels at which adverse 3 effects could occur, somewhat arbitrary safety factors (typically 10 50) 4 are applied to the established threshold. The biological endpoint on which most contemporary standards are based is disruption of foodmotivated learned behavior in subject animals. The threshold SAR for behavioral disruption has been found to reliably occur between 3 and 9 W/kg across a number of animal species and frequencies; a whole-body average SAR of 4 W/kg is considered the threshold below which adverse effects would not be expected. To ensure a margin of safety, the threshold SAR is reduced by a safety factor of 10 and 50 to yield basic restrictions of 0.4 W/kg and 0.08 W/kg for exposures in controlled (occupational) and uncontrolled (public) environments, respectively. For practical reasons, limits commonly called maximum permissible exposure values (MPEs), or 3 An adverse biological response is considered any biochemical change, functional impairment, or pathological lesion that could impair performance and reduce the ability of an organism to respond to additional challenge. Adverse biological responses should be distinguished from biological responses in general, which could be adaptive or compensatory, harmful, or beneficial. 4 The factor of (10 17 db) applies to SAR, power, and power density. The same db applied to the electric and magnetic field results in a corresponding reduction of approximately times (the square root of 10 and 50) in these quantities.

3 RF Standards and the ICES S9 reference levels are expressed in quantities more easily measured outside the body, which are derived from the basic restrictions. The MPEs are generally conservative, so that exceeding the MPEs or reference levels does not necessarily mean that the basic restrictions are exceeded. If the MPEs are exceeded the standard can still be met if compliance with the basic restrictions can be demonstrated. Even though the SAR basic restrictions are the same for many contemporary RF exposure standards and guidelines, the derived MPE limits may differ. The differences are related to the model used to derive the incident fields from the basic restrictions and the incorporated margin of safety. In 2001, the name of SCC28 was changed to International Committee on Electromagnetic Safety (ICES). ICES Subcommittee 4 is now in the final stages of revising C Throughout the 40 year history of C95.1 standards, each revision was more scientifically sound, albeit more complex, than its predecessors. As the interest in the subject grew, the membership of the committees increased accordingly. The subcommittee that developed the 1966 standard consisted of six members; the subcommittee that developed the 1991 IEEE standard consisted of 125 members. discussion of frequency dependence or how to interpret questions like the apparent discontinuity of limits at 20 min and 2 h (and even at 8 h). The hypothesis of a threshold for adverse effects from exposure to electromagnetic energy (0 300 GHz) has been universally accepted. [Minin, 1975; Baranski and Czerski, 1977]. Figure 1 shows a hypothetical threshold curve for an adverse effect (curve A) and an MPE curve (curve B) located below the hazard threshold by a suitable safety factor. Referring to Figure 1, recall that in the US a simple averaging time of 0.1 h was initially chosen because it approximated the thermal time constant of important organs like eyes and testes. This made the SA (specific absorption, i.e., massaveraged energy absorption) limit (Fig. 1) for wholebody exposure doubly conservative since whole-body thermal time constants are in the vicinity of an hour or more. The USSR limit seems to imply an averaging time of 8 h, albeit in a discontinuous formulation [Minin, 1975]. The basis for such an averaging time has never been explained in the available literature. Certainly it makes no sense if the only confirmed ICNIRP The International Commission on Non-Ionizing Radiation Protection (ICNIRP) also develops guidelines for exposure to EM energy across the spectrum. The most recent ICNIRP guidelines for frequencies below 300 GHz were approved in November, 1997, and published in 1998 [ICNIRP, 1998]. At the time the guidelines were developed, the Commission included participation of 17 scientists and 11 external experts from 12 different countries, including Sweden, Australia, Great Britain, Germany, Poland, and the US. The basic restrictions of the latest ICNIRP guidelines, in terms of whole-body averaged SAR, are the same as those of IEEE C95.1, although the reference levels (derived limits) differ slightly. Eastern Europe The history of the development of microwave safety standards in Eastern Europe and in communist countries is sketchy. In the late 1950s the USSR issued microwave safety limits of 10, 1, and 0.1 W/m 2 for people occupationally exposed for durations between 0 and 20 min, 20 min and 2 h, and 2 and 8 h, respectively [Nikonova, 1999]. Besides the apparent ambiguity of an appropriate time when exposures are intermittent, there was little definition of what power density entity was to be measured, what was the role of time and spatial averaging, and many other questions, e.g., how to handle partial body exposure. Neither was there Fig. 1. Thresholds for various effects and hazards expressed as a function oftime.the ordinate is a powerentitylike powerdensityor SAR.Curve Aisthethresholdofsomeadverseeffect.Curve Bisthe compositelimitinasafetystandardspecifyingan MPE(powerdensity) or SAR with an averaging time of T for the SA branch that is dotted oran averaging time lessthant for the solidline SA branch. Note if the standard specified only an SA limit then the MPE would decrease indefinitely with time as indicated by the lower dashed line.

4 S10 Osepchuk and Petersen mechanism for microwave bioeffects is thermal in nature. In more recent times Russia and the Ukraine retain a similar exposure standard in the microwave range except that the limit is a continuous function of exposure time, expressed as a dose [Nikonova, 1999]. The dose is equal to the product of exposure duration and 2 W/m 2, for exposure durations up to 8 h. This is for occupational exposure. A similar dose formulation applies for the general public for exposure times up to 24 h, but at a lower dose (which has slowly increased over the years). From the viewpoint of Figure 1, the Russian standards seem to imply a characteristic time constant of 8 and 24 h, but of unknown basis. We note that really significant exposures almost always are limited to exposure times of minutes or, at most, 1or2h. The trend toward international harmonization of standards, at the moment, faces barriers posed by the regulations and rationales inherited from the USSR era. Many international meetings, such as those noted in Nikonova [1999], and the spread of electronic communication technologies will help eventually reach into Eastern Europe and the former communist countries. This will help in the movement toward international harmonization of standards. FROM RESEARCH TO STANDARDS Creation of BEMSö1979 Before describing the evolution of RF safety standards development and the revision of IEEE C , it is important to understand the evolution of the research community. Before 1979, activity relating to possible health effects of exposure to electromagnetic energy (0 300 GHz) was heavily concentrated in the US and to some extent in the USSR. Coordinated RF/microwave bioeffect research and standards setting had begun in the US in the 1960s; and the relevant professional forums were sessions organized at meetings of the International Microwave Power Institute (IMPI), the IEEE, and URSI (International Union on Radio Science). In 1978 there was an URSI meeting in Finland with sessions on bioeffect research. To provide a forum for those confined to North America, a special symposium was organized by IMPI and the IEEE Microwave Theory and Techniques Society (MTT-S) in Ottawa, Canada [IEEE/IMPI, 1979]. About the same time there was a meeting of a few people from Canada and the US, which triggered the creation of the Bioelectromagnetics Society (BEMS) with key support from the Office of Naval Research and its representative, Dr. Thomas Rozzell. BEMS began its annual meeting in 1979 and its publication, Bioelectromagnetics, in Since then one of the semiannual meetings of the standards committee, ANSI Accredited Standards Committee C95 (ASC C95, which became IEEE SCC28 in 1988 and ICES in 2000) has been held in conjunction with the BEMS meetings. In the early 1980s both the C95 community and BEMS were almost 100% North American, i.e., from Canada and the US, not only in terms of membership but also in authorship of papers in Bioelectromagnetics. For example, of 67 papers published in Bioelectromagnetics in , 93% were from North America and only 7% from elsewhere in the world. In contrast, during 2001, out of 86 published papers, only 42% were from North America and the majority, 58%, were from outside of North America and included all scientifically active regions of the globe. In 1998 the majority, 67% of the 599 members of BEMS, were still from North America. Even though a minority of 33%, the members outside of North America reflect the sites of most current research and publication in this field. The growth of this research has been accompanied by the creation of the European Bioelectromagnetics Association (EBEA), a sister organization to BEMS. Today the membership of ICES also reflects this trend, with 20 33% of the members of its various committees and subcommittees coming from outside of North America. Conversion of Accredited Standards Committee C95 to IEEE SCC28 ö1988 The first few years in the life of BEMS coincided with the intense development of the first dosimetric exposure standard for microwave/rf exposure, that of ANSI C [ANSI, 1982]. In this standard, for the first time the entity SAR was specified, with SAR limits as the basic internal measure of exposure (basic restriction). Furthermore, based on the work of Dr. Guy, Dr. Gandhi, Dr. Durney, and others, the associated derived limits (MPEs) on fields or power density were made frequency dependent, based on models of the human body from child to adult. Thus while the old 100 W/m 2 limit still applied at very high frequencies, in the millimeter wave range, the limit was dropped to 10 W/m 2 in the resonance range for man, roughly MHz, and then abruptly relaxed up to 1000 W/m 2 at frequencies below 3 MHz [Durney, 1980]. This standard was the model for standards activity throughout most of the Western world and in developed countries like Japan. The committee responsible for C was still predominantly composed of members from North America. Also, the C95.1 standard was closely related to rules and regulations by US federal agencies and the

5 RF Standards and the ICES S11 IEEE, including its national activity under USAB (United States Activities Board, now IEEE-USA), and the IEEE was still a cosponsor with the US Navy of this committee. During the early 1980s a uniquely US phenomenon, that of litigation, was to affect and greatly influence the evolution of the standards community. In the celebrated lawsuit of ASME vs. Hydrolevel, the US Supreme Court ruled by 5 to 4 that a professional society like ASME (American Society of Mechanical Engineers) could be held liable for the misdeeds of staff and volunteers in its committees that develop standards [Breitenberg, 1987]. In that case the wrongdoing was to issue interpretations of a standard that favored a company associated with the drafter of the interpretation and was practically damaging to a competitor. The reaction to this lawsuit in the standards community was twofold. On the one hand, sponsors, like ANSI, ruled that the committees of volunteers developing their standards could no longer be labeled ANSI Committees. Instead such committees would only be accredited by ANSI. On the other hand, individuals on the C95 committee and subcommittees voiced concern over their liability in the still remote chance that the committee was cited in such litigation. Thus during the 1980s, while the C95.1 standard was the basis for newly developing rules issued by the Federal Communications Commission and proposed federal guidance by the US Environmental Protection Agency, the leadership of Accredited Standards Committee C95 (ASC C95) began exploring possible solutions to the litigation threat, no matter how remote. Chairman Saul Rosenthal, a leader in the organization of URSI sessions on EM bioeffects and standards and a founder of BEMS, worked with F.K. Storm, R.C. Petersen, J.M. Osepchuk, and E.R. Adair to discuss a new exclusive relationship with the IEEE. The US Navy had already indicated that it would be more acceptable in the modern age for such a committee to be sponsored solely by a professional society, especially an international society, and not a military branch in one country. In the late 1980s, many meetings were held at IEEE Headquarters in New York or at the IEEE Operations Center in Piscataway, New Jersey, with various groups and individuals of the IEEE staff and the IEEE Standards Board. Although there was opposition both within and outside of the IEEE, the IEEE agreed in 1988 to sponsor and convert the ASC C95 committee to an IEEE Standards Coordinating Committee with the designation SCC28 and the title Nonionizing Radiation. Its scope and stated tasks would remain the same, but now SCC28 would be strictly supervised by the IEEE Standards Board and would operate under IEEE rules. At the same time, all volunteers within SCC28 working on an approved project, whether IEEE members or not, would be indemnified against litigation, no matter how remote. In entering the decade of the 1990s, SCC28 had a new Chairman, Dr. Thomas F. Budinger, MD, a member of the National Institute of Medicine, and rising level of activity. Soon to be issued was the very detailed standard IEEE C , with two tiers in the resonance range of man. C had many improvements, like frequency dependent ramps on MPE as well as averaging times to assure continuous limits as a function of frequency and an improved match at 300 GHz to the MPEs of existing laser standards such as ANSI Z [ANSI, 2000], IEC [IEC, 2000], and the ICNIRP laser guidelines [ICNIRP, 1997]. At the same time, the committee addressed the low frequency range, 0 3 khz, by creating a new Subcommittee 3, initially chaired by Dr. John Bergeron and William Feero. This new task was especially difficult due to the contemporary fear of 50/60 Hz fields resulting from the (now vanishing) power line scare, triggered by reports based on weak epidemiological evidence. International Growth of SCC28 and the Creation of ICES In 1995, a new but related standards coordinating committee, SCC34 Product Safety Relative to the Safe Use of Electromagnetic Energy, was approved by the IEEE Standards Board. 5 The scope of this committee is to develop standards for specific products over the frequency range where SCC28 exposure limits exist. The goal is to express standards in terms of easily measured parameters, e.g., output power, current, and voltage, that will be directly derived from the basic restrictions found, for example, in the latest revision of the IEEE C95 standard or the ICNIRP guidelines. SCC34 also develops standards, guides, and recommended practices that describe measurement protocols for determining compliance with the basic restrictions and derived limits found in IEEE C95.1 and other relevant national and international standards and guidelines. The first SCC34 project was a recommended practice for determining the peak spatial-average SAR in the human head from wireless communications devices using measurement techniques. Because of the importance of uniform global standards in this area, the subcommittee developing this standard was quickly populated with experts, many from outside the US, who 5 SCC34 was originally a collaborative effort between IEEE and the Electromagnetic Energy Association (EEA), which was disbanded in August 2001.

6 S12 Osepchuk and Petersen recognized the value of the open IEEE consensus process and who thus also became aware of SCC28 activities. The SCC28 subcommittee that developed C standard (SC4) and the parent committee that approved it were comprised mostly of members from North America; less than 4% were from outside the US. In 1996 an SCC28 Executive Committee (ExCom) was established to direct committee activities and promote the committee internationally. The ExCom recognized that to many outside of North America not familiar with IEEE standards activities, IEEE incorrectly conveyed an aura of a US committee dominated by industry. To address this problem, an International Liaison Committee was created, and it and the SCC28 Membership Committee became active in enhancing international visibility and recruiting key members from outside of North America. It became apparent to the SCC28 ExCom that there was a serious lack of brand image recognition internationally, i.e., SCC28 did not convey any sense of the scope of committee. The titles of other organizations that developed standards and guidelines in this area at least conveyed some sense of the scope of their committee, e.g., ICNIRP. In 1999 and 2000 the SCC28 ExCom deliberated on changing the name of the committee to something that would convey meaning to those not familiar with IEEE functions. It was decided at that time to establish an umbrella committee that would provide oversight to both SCC28 and SCC34, as well as to any future related committees. The name International Committee on Electromagnetic Safety (ICES) was selected as appropriate and meaningful. (See Fig. 2 for a depiction of the ExCom view of the future ICES.) In March 2001, the Standards Board approved of the name change from SCC28 to ICES. Note that in Figure 2 the goal of ICES is to have oversight not only of Fig. 2. ICESasthefocalpointintheglobalprogramforstandardsin electromagnetic safety. the activities of SCC28 but of the product safety committee SCC34, as well as any new committees that would be established, for example, to develop environmental standards. Environmental standards would be useful in mitigating effects associated with RFI (radio frequency interference), for example, and effects to flora and fauna. Such a standard committee could also openly debate, as a matter of social policy, the optimum balance between safety margin and economic and operational costs for the users of systems emitting electromagnetic energy. Thanks to the efforts of its International Liaison Committee, currently chaired by Dr. Michael Murphy, and the Membership Committee chaired by Dr. Tom McManus, ICES membership on the parent committee now stands at 109 with 33 from outside the US and representing 17 countries. A similar representation from outside the US is seen in the subcommittees. The goal is to maintain at least the same percentage of non- North American members as that of the IEEE. Although most semiannual meetings of SCC28/ICES have taken place in the US, the 2000 summer meeting was held in conjunction with the BEMS meeting in Munich, a special meeting was held in December, 2001, in Luxembourg, and the 2002 summer meeting was held in conjunction with the BEMS Quebec City meeting. Plans are to hold meetings more frequently outside of North America. Interest in IEEE C , Standard for safety levels with respect to human exposure to electromagnetic fields, 0 3 khz, [IEEE, 2002] by a number of entities outside of the US will generate even further recognition and interest in the ICES process and activities. The evolution of the consensus community on standards from a small US committee to an international forum has been linked to the research and leadership of Eleanor Adair. As part of the IEEE community (Fellow) she has filled many posts, including Cochairman of SC-4 during the critical phase of the development of C , part of the leadership team that successfully and painfully negotiated with the IEEE on the conversion to SCC28, Vice Chairman and Chairman of IEEE COMAR (Committee on Man and Radiation), and Vice Chairman and Chairman of ICES. During the late 1990s she organized two workshops on the links between standards for microwaves and lasers and published a comprehensive proceedings. She helped recruit individuals who played prime roles in international expansion like Dr. Murphy, Dr. McManus, and Dr. Bodemann, the present Vice Chairman of ICES. Dr. Adair is a charter member of BEMS, served as its treasurer in the mid 1980s and has lectured widely. She now will lead ICES in this new period of international harmonization of standards.

7 RF Standards and the ICES S13 6 The IEEE SASB operating procedures can be found at Internet site 7 Balloting groups vary in size. For example, the number of members in the balloting groups that approved the C (safety limits for frequencies between 0 and 3 khz) and C (measurements) was 56 and 28, respectively. Fig. 3. Representation of the ICES/IEEE standards development process. ICES/IEEE PROCESS Throughout 40-plus years of activity, the committees and subcommittees that developed the C95 standards have been recognized for their open, transparent consensus process and with the broadest scientific consensus. The C95 standards have been the most innovative and have had the greatest influence on RF/microwave safety standards worldwide [Petersen, 1999]. ICES adheres strictly to IEEE policies and procedures. 6 The subcommittees that develop the standards are comprised of the technical experts; membership is open to anyone with an interest and who is willing to contribute. Except for the officers of the committee and subcommittees, IEEE membership is not required. Membership on the parent committee is also open; but to ensure balance, applications are reviewed by the Membership Committee and the ExCom before granting approval. The parent committee is comprised of technical experts and stakeholders, a role of whom is oversight to ensure due process has occurred at every level. Balloting on the subcommittees and parent committee is by individual, not by organization. Although not required, ICES subcommittees follow the same rigid rules required by the parent committee. (See Fig. 3 for a representation of the ICES/IEEE process.) Approval of a draft at both levels requires a formal ballot and a return of at least 75% of the ballots. A balloting group process is followed to ensure that this requirement is met, i.e., all subcommittee and committee members are invited to join a balloting group for that particular standard; those who join agree to review the draft and return the ballot within the prescribed time. Only balloting group members are sent ballots. 7 Every substantive change to the draft resulting from ballot resolution and every nonreconciled negative ballot must be circulated to the balloting group with a rebuttal, to offer voting members an opportunity to comment, affirm, or change their vote. If after recirculation 75% of the initial number of returned ballots remain affirmative, the draft is considered approved and moved to the next level. The same process is followed at the subcommittee and the parent committee level but the IEEE SA Balloting Center conducts the balloting for the parent committee. All balloting is done electronically the drafts are posted on the ICES or the IEEE Standards Association websites. Although no longer mandatory, drafts being balloted by the parent committee are sent to interested IEEE societies and other professional organizations such as BEMS, ICNIRP, NCRP, for comment. Responses received from coordinating organizations are not considered votes, but all comments are considered and circulated to the balloting group. Negative ballots are reconciled or rebutted by the subcommittee. During this time the standard is also submitted for IEEE editorial and legal review; required changes considered substantive necessitate another recirculation. Once approved, the standard is submitted to the IEEE SASB Review Committee (RevCom) for review to ensure due process has occurred, e.g., committee and SASB rules were strictly adhered to, all negative ballots were addressed, etc. If approved by RevCom, the standard is placed on the SASB consent agenda for approval. Thus the role of the SASB is oversight. Once approved by the IEEE SASB, the document becomes an IEEE standard; and it is then forwarded to ANSI, now a clearing house for standards developing organizations. The standard is advertised for public comment and only after comments are satisfactorily resolved does the standard become an American National Standard. Although the process is complex, it ensures openness and full documentation at every level. The types of documents produced by ICES are standards (specifies mandatory requirements), recommended practices (stresses the word should ), and guides (furnishes information). Trial-use standards, recommended practices, or guides are possible in those cases where when the document will be published for a limited period, no longer than 2 years, before it becomes

8 S14 Osepchuk and Petersen an official IEEE document or is withdrawn. Indeed, during the early work of SC3 (0 3 khz) a trial-use guide essentially adopting the ICNIRP limits was proposed, but was not approved by the committee. REVISION OF C Figure 4 is a representation showing the SC4 literature review process being followed during the revision of IEEE C The Literature Surveillance Working Group identifies all relevant studies reporting biological responses, from reversible effects and responses of adaptation to irreversible and biologically harmful effects. At this point, more than 1800 papers have been identified from a number of databases, as well as from inputs from federal agencies and other organizations. The papers undergo a comprehensive engineering review by two randomly selected reviewers from the Engineering Evaluation Working Group and by two randomly selected reviewers from the appropriate biological evaluation working group in vivo, in vitro, or epidemiology. When necessary, a statistical evaluation is carried out. The reviewers are subject matter experts, many of whom are not members of SC4. Theoretical papers, e.g., papers that speculate on various mechanisms of interaction, are reviewed separately and judgments made as to their relevance for standard setting. In order to expedite the process of handling large amounts of data (several thousand evaluation forms), the process has been computerized. Summaries of the evaluations are provided to the Risk Assessment Working Group, who evaluate the implied risk for human beings and define a threshold SAR for which potentially deleterious effects are likely to occur in humans. Fig. 4. Schematic representation of the ICES literature evaluation process for the revision of IEEE C Because of the large number of reviews required and the limited number of active reviewers, the literature evaluation process was taking longer than expected. To help move the process forward, key papers were identified for immediate review, and a decision was made to designate subject matter experts to review pertinent papers in their field and produce white papers that summarize the relevant literature and provide conclusions based on the weight of evidence. Topic areas include ocular effects, cancer/mutagenesis, thermoregulatory responses, calcium efflux, CNS, and lifespan. The summaries and conclusions are being used to prepare the rationale (informative) section of the revision. Abbreviated summaries of many of the white papers were presented at the Air Force workshop held immediately before the 2002 BEMS Annual Meeting in Quebec City and are presented in this special issue of Bioelectomagnetics. A number of issues relating to the 1991 standard are being addressed, including more realistic time averaging values in the microwave-millimeter wave regions and critical examination of the transition region between the IEEE C (0 3 khz) [IEEE, 2002] and IEEE C (3 khz 300 GHz), where the effects associated with electrostimulation dominate or overlap with effects related to tissue heating. The peak spatial-average SAR values and corresponding averaging volume, the development of a scientific basis for the averaging time at frequencies below 100 khz and for induced current and contact current, and the development of a scientific basis to protect against spark discharges are also being addressed. GLOBAL ISSUES International Harmonization During the past few years, representatives of ICES have participated in WHO EMF Standards Harmonization meetings throughout the world to present information on ICES, IEEE standards, and the standards process. Also, at the request of ICNIRP, the leadership of ICES and ICNIRP met in Munich during the BEMS meeting in June A dialog was initiated on implementing procedures that would allow sharing of draft documents between the two organizations. This was followed by another meeting in San Antonio in November 2000 to continue the dialog. The possibility of holding a jointly sponsored workshop on thermophysiology was also discussed, but firm plans are not in place at this time. Both committees recognize the importance of harmonized scientifically defensible standards. To some, even slightly differing standards related to safety

9 RF Standards and the ICES S15 suggest uncertainty and a lack of scientific consensus, i.e., unanswered questions (gaps in knowledge). Even though such questions may persist, reaching scientific consensus on standards will be an indication of the belief of the committees that the remaining unanswered questions are not health issues, at least not to the present state of the scientific knowledge. The leadership of ICES, SCC34, and IEC TC106 8 have been working closely together and with the European Committee for Electrotechnical Standardization (CENELEC) and other committees to harmonize standards of global importance, e.g., measurement techniques for measuring SAR associated with the use of wireless handsets. In fact many members of ICES are also members the Technical Activities Groups (TAGs) of their respective National Committees on the IEC committee. Although not strictly related to C95.1, this effort is important to SCC34 and ICES SC1 (measurements) and provides visibility and recognition of ICES and the IEEE in this field worldwide. In fact, the IEC and IEEE have recently entered into an agreement to publish dual logo standards, which should further enhance recognition of the value of a fully documented, open consensus process open to all. Assessment of the Literature Although extensive, much of the peer reviewed literature reporting bioeffects of EM energy is of poor quality. Often experiments are plagued by artifacts, many of which are the result of deficiencies in microwave engineering. In many cases reported findings cannot be replicated. Even if valid, papers sometimes do not present sufficient quantitative information for use in setting standards. This problem has long been recognized [Osepchuk and Petersen, 2000], and the extensive computerized ICES literature review documents such assessments. Beyond ICES the whole concerned community, researchers, editors, and reviewers, needs to more adequately address this issue and work to improve the quality of papers. One philosophical aspect must be resolved. When followup studies do not replicate an original study, some resist a conclusion that the original study was flawed or not valid. Instead explanations are sought to validate all studies. In reality, as demonstrated in the broader history of science, flawed findings do occur, e.g., in the matters of polywater, cold fusion, and other 8 IEC TC106 is a new committee of the International Electrotechnical Commission whose scope is to provide standards for assessing human exposure to electric, magnetic, and electromagnetic fields. Although the committee produces both product family and generic standards, these standards do not refer to any specific exposure limits but can be used to ascertain conformity with the criteria of ICES, ICNIRP, etc. subjects. One commentator [Foster, 2000] concludes: many reported effects find conventional explanation or simply disappear when followup studies are conducted under better controlled conditions. The importance of replicated studies and confirmed effects for use in standards-setting cannot be over emphasized. Although the literature reporting athermal bioeffects of exposure to microwave/rf energy (other than electrostimulation 9 ) is included in the review process, it has been found to be inconsistent and not useful for purposes of standard-setting. Papers that have reviewed this matter concluded that if such athermal effects exist the anticipated thresholds for producing observable effects are expected to be very high [Foster, 2000], a conclusion buttressed by the fact that the only useful power application [Osepchuk, 2002] involves heating. Despite this, there persist beliefs or speculations about effects and hazards at exposure levels well below safety limits. These are extra-scientific and support the ideas of hypersensitivity and the precautionary principle. SCC28 in 1999 expressed the opinion that policies and procedures that are cautionary in nature are discretionary, e.g., if an employer wishes to add additional safety margin to MPEs that is his prerogative. In such cases, we believe the safety margin is being increased and there is no necessity for such extra margin to protect hypersensitive people. We believe the strengthening of the broad consensus of ICES globally will increase the credibility and authority of science-based standards. Role of Standards in Future Microwave Power Applications In the last few decades we have seen the concerns about potential hazards of exposure to EM energy affect the development and deployment of many systems and products including radar, microwave ovens, video display terminals, police radar, power lines, anti-theft systems, and now the exploding universe of wireless communications. It is important that safety standards be rational and avoid excessive safety margins that could compromise the effectiveness of systems that benefit mankind. Certainly, especially in the post 9-11 era, one would not apply excessive safety margins to weapons detectors that expose the public to magnetic fields. Similarly if systems that prevent fatalities from hazards like electrocution involve some exposure to microwave fields, excessive safety margins applied to microwave exposure is not rational. It is also important that safety margins are reasonably uniform across the spectrum and across the globe, so that there is no unfair advantage 9 Electrostimulation is in a sense thermal since the induced currents are thermalized.

10 S16 Osepchuk and Petersen for some manufacturers of competing products or systems that utilize different parts of the spectrum. Similarly, the existence of varying standards throughout the world impedes free trade. Both ICES and ICNIRP have been working with WHO towards international harmonization of standards. CONCLUSIONS In the last quarter century both BEMS and ICES have grown from North American organizations to broad based international organizations. While BEMS is a forum on research on bioeffects and hazards of exposure to EM energy, ICES is the broadest international forum for developing standards for the safe use of EM energy. Dr. Eleanor Adair has played key roles in both organizations and beyond with the goal of setting rational science-based standards. As the present chairman she leads ICES in addressing many important issues discussed above. With the continuing cooperation between BEMS and ICES we look forward to growth of both organizations along with the emergence and growth of new technologies that use EM energy for the benefit of mankind. REFERENCES ANSI, American National Standards Institute Safety levels of electromagnetic radiation with respect to personnel. ANSI standard C ANSI, American National Standards Institute Safety levels with respect to human exposure to radio frequency electromagnetic fields, 300 khz to 300 GHz. ANSI standard C ANSI, American National Standards Institute American National Standard for the safe use of lasers. ANSI standard Z ASA, American Standards Association Safety levels of electromagnetic radiation with respect to personnel. USASI standard C Baranski S, Czerski P Biological effects of microwaves. Stroudsburg, PA: Dowden, Hutchinson and Ross, Inc. 183 p. Breitenberg MA The ABC s of standards-related activities in the United States. Office of Standards Code and Information, Office of Product Standards Policy, National Institute of Standards and Technology, Gaithersburg, MD NBSIR Durney CH Electromagnetic dosimetry for models of humans and animals: A review of theoretical and numerical techniques. Proc IEEE 68: Foster KR Thermal and nonthermal mechanisms of interaction of radio-frequency energy with biological systems. IEEE Trans Plasma Sci 28: ICNIRP, International Commission on Non-Ionizing Radiation Protection Guidelines on limits of exposure to laser radiation of wavelengths between 180 nm and 1 mm. Health Phys 71: ICNIRP, International Commission on Non-Ionizing Radiation Protection Guidelines for limiting exposure to timevarying electric, magnetic, and electromagnetic fields (up to 300 GHz). Health Phys 74: IEC, International Electrotechnical Commission Safety of laser products. IEC standard IEEE, Institute of Electronics and Electrical Engineers IEEE standard for safety levels with respect to human exposure to radio frequency electromagnetic fields, 3 khz to 300 GHz, IEEE Std C (1999 Edition). IEEE, Institute of Electronics and Electrical Engineers IEEE standard for safety levels with respect to human exposure to electromagnetic fields, 0 to 3 khz. IEEE Std C IEEE/IMPI, Institute of Electronics and Electrical Engineers/ International Microwave Power Institute Proceedings of the 1978 symposium on electromagnetic fields in biological systems, Ottawa, Canada; June 27 30, 1978; Sponsored jointly by the IEEE Microwave Theory and Techniques Society and the International Microwave Power Institute. Michaelson SM The tri-service Program A tribute to George M. Knauf, USAF, (MC). IEEE Trans Microw Theory Tech 19: Minin BA Microwaves and Human Safety (English translation). JPRS Reports No and , Arlington, VA. National Technical Information Service (NTIS). Mumford WW Some technical aspects of microwave radiation hazards. Proc IRE. pp NCRP, National Council on Radiation Protection and Measurements Radiofrequency electromagnetic fields, properties, quantities and units, biophysical interaction, and measurements, NCRP Report No. 67. Nikonova KV Status and implementation of Russian hygienic radiofrequency standards. In: Repacholi MH, Rubtsova NB, Muc AM, editors. Electromagnetic fields: Biologic effects and hygienic standardization. WHO/SDE/OEH/99.5. Geneva, Switzerland: World Health Organization. pp Osepchuk JM How safe are microwaves and solar power from space? IEEE Microw Mag 3: Osepchuk JM, Petersen RC Safety and environmental issues. In: Golio M, editor. The RF and microwave handbook. Boca Raton, FL: CRC Press LLC. pp Osepchuk JM, Petersen RC Safety standards for exposure to electromagnetic fields. IEEE Microw Mag 2: Petersen RC Radiofrequency safety standards-setting in the United States. In: Bersani F, editor. Electricity and magnetism in biology and medicine. New York: Plenum Press