INTERNATIONAL
COMMITTEE on
ELECTROMAGNETIC
SAFETY
Approved Minutes
5th SC-4 Revision Working Group Meeting
Federal Communications Commission
445 12th Street SW
Washington, DC 20554
April 8-9, 2002
1. Call to Order
The meeting was called to order by Co-chairman Chou at 0830 h.
2. Introduction of those Present
Each of the attendees introduced him/herself. See Attachment 1 for list of attendees.
3. Approval of Agenda
L. Heynick requested that “Literature Surveillance Group Report” be added to the agenda
as 8(a). Following a motion by Adair and a second by Heynick, the modified agenda was
unanimously approved (see Attachment 2).
4. Approval of January 10-11, 2002 Minutes
Following a motion by D’Andrea that was seconded by Adair, the minutes of the January
2002 RWG meeting were unanimously approved with minor editorial corrections and
will be posted on the public section of the web.
5. Chairman’s Report
a) SC4 approved guidelines and time schedule. Chou briefly reviewed the
agreements from the January RWG meeting, the changes agreed to at the January
SC-4 meeting that followed (Attachment 3), and the time schedule for completion
of the committee draft (Attachment 4).
b) AF Workshop. Chou reviewed the program of the Air Force Workshop. The
workshop is a tribute to Dr. Adair and her 50 years of RF bioeffect research. The
workshop will be held in Quebec City, Canada on Sunday, June 23, 2002,
immediately before the start of the BEMS Meeting. The white papers will be
presented at this meeting – the papers are due May31st.
Standards Coordinating Committee 28
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
c) BEMS journal – special issue. A special issue of Bioelectromagnetics is being
proposed as an appropriate journal for peer-review and publication of the white
papers. Decisions about a special issue and a guest editor are being considered by
the BEMS Board. The Air Force agreed to fund the special issue. Ziskin raised
the issue of reviewer’s rejection of, for example, papers that raise contentious
issues. Chou said that if it becomes an issue, the editorial Board will have to
decide. He noted that some completed white papers are being posted on the SC-4
website and encouraged members to submit comments to the authors. There was
a brief discussion on the length of the papers – Sheppard noted that online
archiving is available at John Wiley Publishing where additional material can be
archived. Lang commented that it will be interesting to see how review papers
are treated by the editors of Bioelectromagnetics.
6. Risk Assessment Working group Report
Tell reviewed the progress of the RAWG since the last meeting. He said that it would be
extremely useful if every paper in the database could be categorized, e.g., “represents an
adverse effect,” to make it easier to determine which papers are important. Swicord
pointed out that in order to do this it would be necessary to distinguish between relevant
and adverse effects and that such comments/distinctions should be from the reviewer.
Morrissey suggested comparing the “effects” papers with the scores to help identify those
papers that must be considered. Heynick pointed out that the process would be complex
and require a lot of time. Tell agreed but added that such a process would make the task
of the RAWG more direct, e.g., the RAWG members would not have to make decisions
regarding adverse effects. He said that some of the RAWG members might not have the
expertise to do so. Ziskin suggested including this information at the end of each white
paper – Chou supported the idea and D’Andrea pointed out that this was actually the
purpose of the white paper process.
Lotz said he was concerned that the process seems to be changing to the extent that the
RAWG does not fit into the process any more. Adair and Heynick pointed out that they
wrote their white papers because they were on the RAWG. Adair suggested that this
might be an appropriate time for the RAWG to hold a meeting to discuss issues and
options. Tell said that he understands that the consensus is against categorizing each of
the 1500 plus papers as “adverse,” “not adverse,” etc., but needed guidance for moving
forward expeditiously. Bushberg suggested parsing papers by acceptable scores, then by
SAR, and then ensuring that each of the acceptable papers has been addressed in the
white papers. Tell pointed out that the authors of the white papers are generally not
aware of the scores and asked if this was the task of the RAWG. Heynick pointed out
that most of this has already been done by the white paper authors. Mantiply suggested
peer review of each of the white papers by the RAWG – Ziskin suggested making the
scores available to the authors of the white papers.
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
FOR ACTION
Blick is to send the authors of each of the white papers the scores of those relevant
papers that have undergone a complete review.1
Adair read a brief section of the 1991 standard that described the role of the RAWG in
the development of that standard and again suggested that the RAWG consider meeting
before the June SC-4 meeting.
FOR ACTION
The RAWG is to meet before the Quebec City SC-4 meeting to resolve the issue of
how to proceed.
D’Andrea suggested that Tell ask each author of a white paper to provide a list of those
papers considered important. Tell said that might help to try understand, for example,
why some papers with high scores are judged irrelevant.
FOR ACTION
Each author of a white paper is to send a list of those papers considered important
to Tell. The list is to be compared with the results of the reviews (database).
Curtis asked how the effects of unknown health consequence would be handled – Chou
replied that it would not be addressed. Erdreich agreed, adding that if models do not exist
to link an effect to a health consequence the issue is irrelevant to standard setting. Curtis
explained that he is only concerned if a single-tier standard is proposed – it is not an issue
if two tiers are adopted. He said that he is also concerned about well-established effects
that have unknown health consequences.
7. Mechanism Working Group Report
(No formal report.)
8. Literature Evaluation Working Group Reports
a) Literature Surveillance. Heynick reported that the latest list, containing 1593
papers, has been posted on the website. About 250 papers are peripheral and do
not have to be reviewed.
b) Engineering. Blick read a summary of the status of the engineering evaluations.
As of April 5th, 1716 reviews have been requested, 1513 reviews have been
received and 649 papers have complete reviews. He also provided the following
breakdown by score:
1
Scores ≥ 3.0
355
Scores < 3.0
294
For convenience, a list of action items appears in tabular from in Attachment 5.
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Breakdown by Average Score
Avg Score
N_
5.0
13
4.5
54
4.33 (3)
4.0
3.67 (3)
3.5
3.33 (3)
3.0
2
88
4
86
2
106
c) In Vivo. Blick presented the report of the in vivo working group. He noted that 1084
reviews were requested, 951 evaluations were received and 419 papers have complete
reviews. He provided the following breakdown by score:
Scores ≥ 3.0
306
Scores < 3.0
114
Breakdown by Average Score
Avg Score
N_
5.0
13
4.5
40
4.0
88
3.67 (3)
3.5
3.33 (3)
3.0
5
80
2
78
Blick also reported that a summary database is available on CD.
d) In Vitro. Blick also presented the report for the in vitro working group. He said
that 187 reviews are in the database and three more papers have to be sent out for
review. The number of summaries is unknown at this time.
d) Epidemiology. Chou reported that Col. Russcio agreed to take over the
epidemiology reviews but is probably now busy with the PAVE PAWS issue on Cape
Cod. Blick noted that before he left, Gorsuch scanned most of the papers into pdf
format for ease of distribution to the working group members.
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
9. Report of Responses to the 23 Key Questions and Issues
a) One vs two tiers (see Attachment 6). Tell reported that the results of the survey
indicate that the group is split almost 50:50 on the one versus two-tier issue. In
referring to the survey comments, Sheppard said that he was impressed with
Osepchuk’s comments and the history of the adoption of two tiers. He said that
he liked the idea of differentiating between two types of standards – one with time
averaging as in the 1991 standard, and another, an environmental standard, that
sets limits to protect against any undesirable effects, including the effects of RFI,
etc. He suggested considering Osepchuk’s philosophy and adopting a single tier
safety standard and a separate environmental standard. Mantiply noted that this
could resolve the concern of OSHA, e.g., OSHA would be concerned with the
safety standard and FCC with the environmental standard since their charge is to
protect the environment. Curtis agreed – Lotz said that he would not like to see
the two separated. He noted that the issue is similar to that faced by SC-3 and
ICNIRP – both sets of limits have to be based on the results of short-term studies.
Tell noted that the issue is going to be more severe if RFI effects are included –
which is not in the scope of the committee. Adair noted that if this philosophy is
adopted, Osepchuk would probably take the initiative in developing the
environmental standard.
The discussion then focused on the meaning of “safety standard,” why standards
for ionizing radiation are two tiers, linear non-threshold phenomena, mechanisms,
the rationale for the laser MPEs, reversible effects of exposure to lasers, e.g.,
flash-blindness, the meaning of the word “safety factor,” etc.
b) 3 or 6 GHz as the upper limit for SAR. Tell reported that 5 people supported an
upper limit of 3 GHz, 10 supported 6 GHz and 1 was undecided.
c) 1 g or 10 g averaging mass. The results of the survey indicate that 11 people
were in favor of changing the averaging mass to 10 g, 5 were in favor of retaining
the 1 g value and 3 were undecided.
d) Measurement distance. The results of the survey indicate that 6 people were in
favor of specifying a minimum measurement distance, 8 were opposed and 4 were
undecided.
e) Averaging time. The results of the survey indicate that 15 people were in favor
of changing the averaging time to that presented in the 1st draft, none were against
and 3 were undecided.
f) High frequency partial-body limit. The results of the survey indicate that 8
people were in favor of retaining the current limits, 1 was in favor of change and 5
were undecided.
g) Safety program. The results of the survey indicate that 1 person was in favor of
including a safety program in the revision, 12 were opposed and 1 was undecided.
Chou said that he was surprised that so many were against this issue. Adair
pointed out that SC-2 is already developing a model for organizations to develop
their own safety programs. Tell said that he was in favor of including some
recommendations – he was not sure that the SC-2 document would be finished
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
before the C95.1 revision is approved and, therefore, SC-4 should make some
recommendations.
h) Safety factors. Discussion on the issue of “safety factor” led to the following
action item:
FOR ACTION
The working group is to decide on a definition of the term “ safety factor”
before the June meeting.
i) “Non-thermal” – definition. The results of the survey indicate that 4 people were
in favor of retaining the term “non-thermal,” 10 were opposed and 2 were
undecided. Questions arose as to the definition of “non-thermal” – Heynick said
that he has already defined the term, including exceptions. Sheppard pointed out
that whichever term is used, it must be precisely defined.
FOR ACTION
Heynick is to send Tell a definition for the term “non-thermal” – including
exceptions.
j)
Contact voltage. The results of the survey indicate that 4 people were in favor of
140 V, none were opposed and 10 were not sure what an appropriate value should
be. Reilly noted that a value of 100 V is probably protective at all frequencies
against shocks and burns but may be far too conservative. Hatfield said that he
was concerned about secondary effects associated with real-life situations where
currents are induced in large conducting objects, e.g., a crane lifting a metal cargo
container immersed in an RF field. Reilly said that it requires about 300 V at
60 Hz to evoke a response and recommended not setting contact voltage limits but
providing other useful information instead, e.g., safe distances. Curtis agreed with
Reilly that guidance is important but suggested adding statements such as “140 V
is probably conservative.” Hatfield said that an actual value is more important
otherwise the expectation of protection under all circumstances may be
unrealistic. Chou suggested that the issue could be resolved by the SC-3/SC-4 ad
hoc group that is investigating continuity between C95.1 and C95.6. He asked
Reilly to review the latest draft, comment and recommend any changes necessary
to ensure consistency.
FOR ACTION
Reilly is to review Draft 2 of the C95.1 revision and recommend any
necessary changes to ensure consistency between C95.1 and C95.6 in the
transition region.
k) Near field, far field, multiple-source. (No conclusions.)
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
10. Report of Responses to the 23 Key Questions and Issues
Chou presented a series of overheads (see Attachment 7) that summarized the key issues
(Questions 13-23) regarding the biological basis of the revision of C95.1.
11. WHO Temperature Workshop Report
Elder summarized the March 21-22, 2002 WHO Temperature Workshop noting that
about 20 invited experts participated. Some of the issues addressed were the importance
of ∆T and the question of the relevance of animals with higher core temperatures. The
Keating paper (a participant at the WHO workshop) was briefly discussed. Ziskin asked
how Keating’s conclusions relate to ambient temperature – Adair replied that it is not
clear. She said that acclimation is important, e.g., the effects of ∆T may be more
important in Finland than in Greece. In response to a question from Erdreich, D’Andrea
replied that it is not clear how Keating obtained the fine details reported in his draft. Lotz
pointed out that most of the effects discussed are drastic and asked about functional
effects. D’Andrea said that these were not addressed – there seemed to be no interest.
Also, there was little data presented on core temperature/duration for functional effects,
e.g., cognitive effects. Swicord pointed out that the original purpose of the workshop was
to address effects associated with heating of specific organs.
12. Normative Section Discussions
a) One vs two tiers. Tell led the discussion on the normative sections of the
revision (see Attachment 8 for presentation). Curtis said that he would not want
to see the levels set such that an unaware public experiences effects – even if
harmless. He said that this is not an issue for occupational exposure, however.
Tell noted that discomfort is related to individuals and there did not appear to be
any trend with age – although the metabolic heating and sweat rates appeared to
decrease with age. Hatfield noted that temperature distribution might be an
important consideration, e.g., the distribution associated with exercise would be
expected to be different from that associate with RF exposure.
Erdreich noted that there are several choices – set one tier for everybody, set two
tiers with the higher tier tied to awareness or set a safety standard and an
environmental standard. Reilly pointed out that SC-3 started with a level that
protected everyone from painful effects associated with electrostimulation – this
was the general public category. The controlled environment is associated with a
higher tier. Curtis said that he supports a single tier standard with relaxation tied
to education, controls, etc. Tell questioned whether people in the workplace
would accept higher SARs. Curtis replied that they would not necessarily but
might if monitored for heat stress, etc. Swicord asked about a level at which
monitoring would commence – Curtis replied that it would depend but the
ACGIH TLVs for heat stress could be used.
Tell asked for a sense of the group regarding sensation as an end point for setting
the limit for the general population. Bushberg said that if so, it would be tied to a
nuisance value and argued for two tiers. D’Andrea pointed out that if the limit is
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
tied to annoyance, what a person is doing at the time is important since there may
be important secondary effects. In response to a question from Reilly, Tell
pointed out that the threshold for behavioral disruption was found to occur
reliably between 3-9 W/kg. The lowest threshold from deLorge’s data was
3.2 W/kg with effects occurring in 50% of the animal subjects at that level.
Chou reviewed the history of the discussions to date and recommended that the
group consider making a decision right now. Tell said that it might be too early
and suggested adopting a policy statement stating that the current standard should
protect everyone. Chou said that based on work to date we should be able to go
forward. The discussion returned to a lower tier based on discomfort or
annoyance. Adair raised the issue of a threshold and Lotz said that he was
uncomfortable supporting this concept. Concern was also raised about the
Keating data presented at the WHO Temperature Workshop. Ziskin asked if
OSHA has requirements for the temperature in the workplace, e.g., in buildings –
Curtis responded that they use ACGIH and now ASHRE data. Adair presented an
ASHRE plot of the comfort zone (see Minutes of January RWG meeting) and
noted that the basis of the revision could be to ensure that people are kept within
this zone.
After some discussion regarding the two-tier approach, there was agreement that
the two-tier approach would be retained and the rationale would be updated as
appropriate.
b) 1 g or 10 g. Tell pointed out that the results of the survey indicated that 11 were
in favor of changing the averaging mass to 10 g and 5 were opposed. Sheppard
suggested tabling this issue. He pointed out that the issue is complex and more
information is needed before a science-based decision can be made. Bassen
agreed with Sheppard and added that he would like to see supporting data before
the value is relaxed – especially biologically-based data. Chou noted that the
SARs are about 60% lower at the higher frequencies, i.e., 1900 MHz, when the
larger averaging mass is used and somewhat less than 60% at the lower
frequencies. Swicord asked if data on the temperature difference between 1 and
10 g would be useful – if there is no difference then the averaging mass should
not matter.
FOR ACTION
Sheppard and Swicord will address the SAR versus temperature issue to
resolve the 1 versus 10 g averaging mass issue.
Ziskin asked if there were issues other than harmonization associated with
changing the averaging mass – Chou responded that it is mainly a
harmonization/globalization issue. In response to a question from Bassen
regarding data specifically on the sensitivity of the eyes and the testes, Elder said
that there is not. Bassen then asked about data on the cornea – noting the work of
Kues. Elder pointed out that Kues’ work has not been replicated. D’Andrea
agreed and pointed out that he could not produce damage to the cornea or retina
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
even at four times the exposure level used by Kues. Ziskin noted that the
difference between 1 and 10 g averaging mass might become important at the
higher frequencies. He said that he uses SAR even at frequencies above the SAR
range – mainly to determine ∆T – and noted that he felt the upper frequency limit
is rather arbitrary. The group agreed to move forward and wait to decide this
issue until after it is resolved by Sheppard and Swicord – by the end of May.
c) Levels for whole-body exposure (average SAR). Chou asked for
recommendation on how to proceed. For example, should the revision be
protective of all and raise the limits for exposures in controlled environments?
Curtis suggested thinking about how to proceed with the rationale, e.g., choose
0.1 W/kg for the lower tier based on Tell’s data and raise the limits based on
controls, safety programs, etc., or choose some other option. Tell noted that the
discomfort index is based on a large amount of data summarized in the ASHRE
Handbook and suggested that it could be used to set the lower tier. D’Andrea
suggested that perhaps the ASHRE data could be more appropriately applied to
the upper tier. Heynick asked if we have accepted the Tell/ASHRE data? Adair
said that it needs to be discussed more – some of the data that went into the
ASHRE document could be subjective. Erdreich agreed and said that she would
like to see some of the data, see how it was collected, etc. Adair explained that
most of the data was collected using rating scales – Tell noted that the scales were
approved by ASHRE. Erdreich said that she would still like to see the data –
there are various ways of setting up rating scales.
The issue of the proper terminology was raised, i.e., use of MPE or PEL
consistently though out the text. Sheppard said that there is a philosophical
distinction and recommended PEL. Swicord agreed noting that the derived limits
are for convenience. Use of the word “maximum” signifies a basic restriction that
cannot be exceeded. The field limits can be exceeded provided the basic
restrictions are not. D’Andrea recommended retaining the term MPE to be
consistent with the laser standards. Petersen made the following motion:
MOTION
Incident power density at frequencies above the SAR region, induced current
density, and SAR will be called “basic restrictions.” The derived quantities,
i.e., incident electric and magnetic field strength, incident power density at
frequencies in the SAR region and below, will be called maximum
permissible exposure values.
The motion was seconded by D’Andrea and was approved unanimously.
There being no further business the first day, the meeting was adjourned at
1705 h.
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
5th SC-4 Revision Working Group Meeting
Federal Communications Commission
445 12th Street SW
Washington, DC 20554
April 9, 2002
Co-chairman Chou called the continuation of the RWG meeting to order at 0835 h. A
decision was made to address the informative sections of the revision at this time.
13. Informative Section Discussions
a) Annex A. Swicord reported that no changes have been made since the last
meeting.
b) Annex B. Swicord said that this annex still needs a short, focused summary
based on the white papers. Each section should have a closing statement: 1)
found nothing, 2) found something – response is thermal. A closing statement
relating to thermophysiology is also needed. Input is needed from the committee.
FOR ACTION
Authors of the white papers will coordinate the completion of Annex B.
Frequency overlap (SC-3/SC-4) region. Reilly addressed the region
overlapping C95.1 and C95.6. He discussed the C95.6 rationale, e.g., general
public threshold raised under controlled environment exposure conditions. He
pointed out that the threshold for the public is based on painful or adverse
sensation. Tell asked if this is subjective. Reilly replied that it is not, exactly –
the thresholds were measured under standard protocols. He said that because of
the tightness of the data a safety factor of 3 was used, which corresponds to a
safety factor of 9 for SAR. The safety factor was added to the threshold for effect
for 1% or less of the subjects tested. Without the safety factor, 50% of the
subjects would experience sensation and 1% would experience pain.
Reilly pointed out that while C95.6 has two tiers at 3 kHz, C95.1 and the draft
revision have only a single tier and an additional tier based on electrostimulation
is needed in the revision over a limited frequency range. Mantiply asked if there
are any known delayed effects associated with painful shock – Reilly replied that
there are not unless a lesion is created or during electroshock therapy, which
induces convulsions. Bassen noted that magneto shock therapy does not produce
seizures but seems to be effective, which to him indicates that the mechanism may
not be clearly understood. In addition to a second tier at the low frequency end of
the revision, Tell recommended an additional MPE for contact current – under
conditions of touch.
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Reilly then proposed the following limits in the overlap region:
Transition Region MPEs – “General Public”
Frequency (MHz)
Magnetic Field Strength (H)
Electric Field Strength (E)
0.003-0.00335
0.547/f A/m
614 V/m
0.0035-0.1
163 A/m
614 V/m
Transition Region MPEs – “Controlled Environments”
Frequency (MHz)
Magnetic Field Strength (H)
Electric Field Strength (E)
0.003-0.00335
1.64/f A/m
1813 V/m
0.0035-0.1
489 A/m
1813 V/m
Rationale (Continued). The discussion went to the issue of choices, e.g., one
versus two tiers, single tier safety standard and separate environmental standard,
whether to base the revision on Tell’s ASHRE data relating to discomfort, etc.
Lang said that he would have a problem with a standard based on subjective data,
e.g., would it also address “electrosensitivity”? Curtis summarized three options.
Option 1:
•
Upper tier based on known adverse health effects (0.4 W/kg): Acute adverse
effects at 4.0 W/kg; Chronic effects at O.4 W/kg.
•
Lower tier (.08 W/kg) recognizes gaps in research, e.g., differences in
populations, chronic exposures, etc. (Safety factor of 5)
•
Consistent with ICNIRP
Option 2:
•
Simple single tier (0.08 W/kg) for most applications.
•
Organizations desiring to exceed 0.08 W/kg must adopt controls (RF Safety
Program) to counter increased risk from higher exposures.
•
Maximum relaxation from program is 0.4 W/kg.
•
Compatible with SC3 and laser standards.
Option 3:
Two Rationales - Two Standards (Environment vs. Controlled)
•
Separates artificial link between two tiers.
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
•
Most sites are under Environmental std which is based on imposed discomfort
(0.08 W/kg)
•
Controlled environments std is based on known adverse health effects
(0.4 W/kg)
Considerable discussion followed about selecting appropriate thresholds, e.g.,
whether 0.08 W/kg is scientifically supported. The issue at this point was that the
numbers have been agreed on – a rationale for the possible choices is now needed,
e.g., single tier relaxed for the controlled environment, two tier, safety standard
and environmental standard. Swicord thought that it was inappropriate to insert
numbers until there is agreement on a rationale. The 0.1 W/kg threshold derived
from the ASHRE data was again discussed. Blick said that basing a standard on a
subjective effect that in turn depends on temperature, air velocity, etc., is
inappropriate. Adair pointed out that none of the subjects in her human studies
could tell when the exposure was on – even at SARs up to 0.4 W/kg.
Tell reminded the group that the white papers are to help the RAWG set
thresholds but he needs more guidance interpreting the white papers, e.g., the
relevance of subtle changes, adverse health effects, etc. He said that a clear
distinction and words to support a conclusion are needed. Reilly noted that
4 W/kg has been established as a threshold for effects associated with acute
exposures and, according to Elder, long-term exposure at 6-8 W/kg WBA may
result in death. He asked if a safety factor of 10 is adequate. Lotz said that more
data are needed to adequately address the safety factor issue for chronic
exposures, but based on Adair’s data and the ASHRE data, a safety factor of 10 is
probably adequate. Morrissey noted that several chronic exposure studies have
been reported with no differences noted in survivability and a number of other
factors. Lotz said that that is important but detailed toxicological studies are also
necessary to adequately address the issue. Elder suggested that the University of
Washington study is a good one to use to set a no effect level.
Adair made the general comment that the white papers have been on the web for
months and urged the group to read them and offer comments to the authors.
Heynick reminded the group that work stoppage is probably the least innocuous
effect reported. Blick noted that the work-stoppage threshold is also associated
with a ∆T of ≈ 1°C – which could be considered potentially adverse. Lotz said
that it was not clear to him that 4 W/kg is the appropriate threshold for adverse
effects. Swicord said that he is concerned that we are not following procedures,
e.g., establish the numbers then develop the rationale rather than develop the
rationale and see what numbers fall out.
Chou explained that we need to agree on a protocol for moving forward. He
referred to Curtis’s options (above) and recommended that we vote on one of the
three options, without the numbers, to establish the protocol. Petersen spoke
against this committee adopting Option 3 (safety standard and environmental
standard) pointing out that the environmental standard is designed to protect the
flora, fauna, effects of RFI, etc., – any effects that could be considered
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Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
undesirable. Protection against such effects, including RFI, is not within the
general scope of SCC-28. Ziskin pointed out that if Option 3 were adopted, the
public probably would not accept the higher limits of a safety standard and the
environmental standard would become the de facto standard. Swicord noted that
the difference between Option 3 and the other two options is a lack of a linkage
between the two standards, e.g., the environmental standard is for 14/7 exposures.
Reilly also spoke against Option 3 – Sheppard spoke in favor noting that it
eliminates the artificiality of the safety factor. He pointed out that the second
standard could have a different biological endpoint and rationale. Bassen asked if
the environmental standard would include partial-body SAR – the consensus was
that it would not. He said that he was concerned that the peak spatial-average
SAR could be raised for occupational exposure.
D’Andrea spoke in favor of Option 2 (relaxed limits for exposures in controlled
environments). Lang also spoke in favor of Option 2.
Chou called for a vote on a choice of an option. After considerable discussion
about how the voting should proceed, it was decided to vote for both the preferred
option and the least favored option. The results of the balloting are shown below.
Least Favored
Preferred
Option 1
0
6
Option 2
4
13
Option 3
Majority
3 (abstained)
(Safety standard and
Environmental standard)
Having noted that Option 2 is preferred, Chou explained that the next issue is to
decide on a level. A decision was then made to defer discussion on choosing an
appropriate number until after a discussion on the role of the RAWG.
Role of the RAWG. Chou explained that the role of the RAWG is to review the
white papers and their summaries and determine the lowest threshold for effects
considered important. He noted that papers with low scores are not relevant and
do not have to be reviewed. Tell asked if papers with low scores were included in
the white papers – Chou said that they were. Curtis suggested that the RAWG
study the white papers, consider all comments and from that determine a
meaningful endpoint and threshold.
The discussion then went to how the RAWG should proceed, specifically. Chou
suggested that the RAWG review the white papers, study the summaries, focus on
key papers, and obtain consensus that the RAWG agrees with the paper’s author.
He noted that most of the white paper authors are already on the RAWG. Curtis
13
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
recommended that the RAWG should also address the issue of excursions in
accordance with Option 2, i.e., relaxing the limits under controlled situations, and
make recommendations.
Blick said that he supports 0.4 W/kg as the basic restriction for the lower tier. He
added that although data exist for animals exposed at these levels, none exist for
humans except under extreme conditions. Elder said that the group has to
consider the Keating data presented at the WHO Temperature Workshop because
of the low thresholds reported. Adair noted that the working group at the WHO
workshop considered Keating’s data as outliers. Tell concluded that there are two
important considerations for the RAWG. The first is to evaluate the data in
Keating’s paper. Adair said that a draft should be available in about three weeks
and she could ask for permission to distribute the paper when it is approved for
publication. The second consideration is a need for a precise understanding of
exactly what the standard is designed to protect. Tell said he needs a clear
understanding, for example, of the differences between the terms “adverse effect,”
“harmful effect,” and “adverse health effect.”
The discussion then went to the issue of selecting the appropriate threshold. Chou
asked if, based on the white paper reviews, there was any reason to change what
we already had. Heynick supported a threshold SAR of 0.4 W/kg as being a value
that would be safe for all. The issue of the Lai-Singh paper was raised as an
example of an important paper that was reviewed, as were papers reporting
attempts at replication. Heynick read the summaries of the white papers on
cancer and calcium efflux. He noted that the same summaries will go into the
informative section of the revision and the complete papers will be referenced.
Lotz pointed out that it is important to discuss papers such as the Lai-Singh paper
where attempts have been made at replication. He said that it is also important to
distinguish between non-replicated papers, such as the Repacholi paper, and
papers where attempts at replication have failed to produce the same results, e.g.,
Lai-Singh.
Heynick also read the summary of the white paper on teratogenesis – in nonhuman species. The summary will also be part of the informative section of the
revision with references to the complete paper. The discussion then turned to
whether summary statements from other papers, e.g., the Doll report, should be
included. It was agreed that inclusion does not necessarily mean acceptance –
normally statements from sources outside of the working group would not be
included. The conclusion of the white paper on calcium efflux was discussed.
Elder explained that calcium efflux data is not useful for standard setting.
14. White Paper Reports
a) Ocular effects. J. Elder reported that a ∆T ≥ 41°C at an SAR ≥ 150 W/kg and an
exposure duration ≥ 30 minutes results in the production of lens opacities in the
rabbit eye. Facial exposures caused burns but did not produce cataracts in the
monkey eye. He cautioned that the rabbit data should not be extrapolated to
humans. He noted that Carpenter had measured a temperature increase of 1.0 to
14
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
2.5 °C in the body of rabbits irradiated sufficiently to produce cataracts.
Carpenter (1977) also demonstrated cooling effects in the eye relative to large
increases in temperature that followed euthanization of the rabbit. Other ocular
effects, e.g., Kues data, were found to be inconsistent and not useful for defining
an adverse effects level. Moreover, cataracts have not been found to be produced
in humans by either continued or repeated exposures to low levels. Elder noted
that the summary of the ocular effects white paper is already inserted in the draft
of the standard.
b) RF hearing. Elder reported that the summary of the RF Hearing White paper has
also been entered in Annex B (pg. 33) of the 2nd draft of the revision. He
explained that a quiet environment is required to hear the pulses, specific pulse
parameters must be specified to evoke the response – not average power density,
and the effective modulation range extends from about 216 Hz to about 10 kHz.
He said that thermoelastic expansion theory explains most of the phenomena, i.e.,
rapid thermal expansion following rapid heating (~ 5×10-6 °C). He also pointed
out that several of the citations in his white paper are not in the IEEE database.
c) Life span. Elder noted that a summary of the life span data are not yet entered
into Annex B. He explained that low level RF exposures have not been found to
shorten life or be associated with diseases such as cancer.
d) Behavioral effects. J. D’Andrea reported that thermal effects account for all
reported behavioral effects. In response to a question regarding repeated chronic
studies having a threshold SAR lower than ~ 4 W/kg, D’Andrea replied that there
are not enough chronic exposure studies in which behavior has been measured
and, therefore, he cannot explain a lower threshold for repeated chronic
exposures. He said that he would review Sheila Johnston’s review paper on
cognitive effects associated with prolonged cell phone use. Elder asked if there
was any new literature that would influence the 4 W/kg basis for the 1991
standard – D’Andrea responded that Figure 3 of his white paper show all of the
studies to date related to behavioral disruption under acute exposure conditions.
He agreed that the title of the figure needed to be changed and that, perhaps,
another figure with data from other behavioral paradigms should be added. He
noted that Figure 3 has more paradigms than behavioral disruption. Cleveland
pointed out that good definitions of “behavioral effect” and “behavioral
disruption” are needed – D’Andrea agreed.
e) Thermoregulation. E. Adair noted that comments provided by co-author David
Black had resulted in revisions that have not yet been approved by Black. She
said that appropriate summaries would be written and entered into Annex B when
Black and others respond to her request for comments. Adair pointed out that
~25% of the references in her white paper are not in the IEEE database because
they deal with basic thermalphysiology and are not related to RF exposure. The
introductory background material on thermoregulation will be greatly shortened
in the paper that will be submitted to the BEMS journal.
Tell asked if there was data available about local temperature increase in tissues
or organs resulting from RF exposure that could provide information about the
15
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
greatest vulnerability of humans to this energy, i.e., how high can the local SAR
be – and where – yet still be safe relative to human thermoregulation? That is,
could the partial-body SAR of 8 W/kg be relaxed whether averaged over 1 or 10 g
of tissue? Adair couched her answer in terms of both local temperatures in brain
(squirrel monkey hypothalamus) and local surface temperatures in RF-exposed
humans. She said that the use of fluid-filled thermodes implanted in the monkey
hypothalamus indicate that a threshold of ∆T = 0.3°C will initiate a change in
thermoregulatory response, either autonomic (metabolic, skin blood flow,
sweating) or behavior (selected Ta). RF exposure of monkeys at WBA SAR ≤ 6
W/kg (2450 and 450 MHz) seldom show ∆T in the hypothalamus as high as
0.5°C. Even monkeys thermoregulate efficiently. Presumably humans would
thermoregulate much more efficiently as evidenced by ∆Tesophageal ≤ 0.1°C during
45 min exposures at 100, 450 and 2450 MHz – both whole- and partial-body.
∆Tskin was found to be frequency and Ta dependent in these studies.
Chou referred to data on two-way radios mounted on the body for occupational
use and pointed out that Landendijk’s model predicts ∆T ≤ 0.5°C increase in brain
temperature associated with the use of a hand-held transceiver operating at 8 W.
Tell explained that he is looking for a better way to develop a partial-body peak
SAR. Lotz said that recent micronuclei studies might be useful. Adair said that
she would confirm the squirrel monkey data for WBA SARs and ∆Thypothalamus
resulting from such exposure. D’Andrea said that he would look into data from
the rhesus monkey for head-only RF exposures and ∆Tbrain. He added that the
Burr and Krupp data might be relevant. Adair also mentioned a paper recently
received from Ken Foster on the basis for setting RF exposure standards. She will
ask Foster if this paper (or book chapter) could be posted on the SC-4 website.
15. Business Carried from Last Meeting
The question was raised as to whether the original value of 4 W/kg for behavioral
disruption, with a range of 3.2-8 W/kg, is still valid as an adverse effects level. Lotz
questioned the continued use of this value because effects at lower levels have been
reported for both acute and chronic exposures. Chou asked whether to keep at this time
0.4 and 0.08 W/kg as the two levels for exposure. Adair, Heynick, Blick and others
stated that in the earlier vote on options, values were not specified. Chou then reiterated
his proposed work schedule.
•
May 31 – Deadline to finish White Papers
•
Early June – RAWG to meet to make some decisions on appropriate numbers
•
Before June 15 – Complete 3rd Draft
Lotz agreed to review the thermoregulation white paper, Chou will contact Black about
his review of this white paper. Swicord urged that Annex B be completed. Reilly is to
send data, including pulse levels, especially for the second tier, to Tell, Chou and
D’Andrea.
16
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
FOR ACTION
Lotz will review the Thermoregulation White Paper.
Chou will contact Black regarding his review of the Thermoregulation White Paper.
Reilly is to send data, including pulse levels, to Chou, D’Andrea and Tell.
The discussion returned to the normative section of the revision. Blick questioned the
possibility of the occurrence of skin burns associated with exposures of small spots at
millimeter wave frequencies at 100 mW/cm2. Tell and Swicord pointed out that 4.1.3 of
Draft 2 takes care of this issue. To a question about the SC-3 controlled environment,
Reilly said that the employment of warning signs is included. Adair posed a problem
concerning the use of “general public” as a substitute for “uncontrolled environment” in
the revision. She said that more than 4 years of debate on the description of the two tiers
was held before C95.1-1991 was finalized in terms of the exposure environment rather
than the population exposed. The response was that the approval of “Option 2” earlier in
the day included “general public” and not “uncontrolled environment” for the lower tier.
Adair warned that this would be brought up for discussion at the SC-4 meeting in Quebec
City.
Heynick announced that he would not be preparing Annex F or Annex G. This was
accepted.
16. New Business
The decisions made at this meeting were summarized. Specifically,
•
Two-tier approach will be retained
•
Voted to adopt Option 2 – one level safe for all and a relaxed upper level for the
controlled environment
•
Have not decided on specific numbers for the two tiers.
•
Sheppard and Swicord will work on the 1 g versus 10 g issue
•
There were no surprises revealed at the WHO Geneva workshop – the eyes are the
most sensitive organ to protect; 40°C is the key upper limit
•
Designating two tiers as “general population” and “controlled” may lead to
opposition at the June meeting
•
All first authors request comments on the white papers
•
White papers must be in the BEMS journal format
17. Forthcoming Meetings
SC-4 will meet at the Loews le Concorde Hotel in Quebec City, June 29, 2002 from 0800
to 1730 h.
17
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
The SC-4 Revision Working Group will hold its 6th meeting at the FCC in Washington
DC on September 9-10, 2002.
18. Adjourn
There being no further business, upon a motion by L. Heynick, the meeting was
adjourned at 1615 h.
18
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
ATTACHMENTS
ICES SC-4 Revision Working Group Meeting
Ft. Lauderdale, FL.
January 10-11, 2002
1. Attendance List
2. Preliminary Agenda
3. Agreements from January RWG and SC-4 Meetings
4. Time Schedule
5. Table of Action Items Arising at this Meeting
6. Comments Related to the issue of One vs Two Tiers
7. Copy of Chou Presentation RE Questions 13-23
8. Tell/Erdreich Presentation
19
ATTACHMENT 1
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Attendance List
5th SC-4 Revision Working Group Meeting
Federal Communications Commission
445 12th Street SW
Washington, DC 20554
April 8-9, 2002
Name
(Last)
Name
(First)
Affiliation
Country
E-Mail
1.
Adair
Eleanor
Ind Consultant
US
eleanoradair@aol.com
2.
Bassen
Howard
FDA/CDRH
US
hib@cdrh.fda.gov
3.
Blick
Dennis
AFRL/HEDR
US
dennis.blick@brooks.af.mil
4.
Bushberg
Jerrold
UC davis
US
jebushberg@ucdavis.edu
5.
Chou
C-K
Motorola
US
ck.chou@motorola.com
6.
Cleveland
Robert
FCC
US
rclevla@fcc.gov
7.
Curtis*
Robert
OSHA
US
bob.curtis@osha.gov
8.
D’Andrea
John
NHRC DET Brooks AFB
US
john.d’dandrea@navy.brooks.af.mil
9.
Elder
Joe
Motorola
US
joe.elder@motorola.com
10.
Erdreich*
Linda
Exponent
US
lerdreich@exponent.com
11.
Harrington
Tim
FCC
US
tharring@fcc.gov
12.
Hatfield
Jim
Hatfield & Dawson
US
hatfield@hatdaw.com
13.
Healer*
Janet
NTIA
US
jhealer@ntia.doc.gov
14.
Heynick
Louis
Ind Consultant
US
louhey@mindspring.com
15.
Lang
Sakari
Nokia
FI
sakari.lang@nokia.com
16.
Lotz
Greg
NIOSH
US
wlotz@cdc.gov
17.
Mantiply
Ed
FCC
US
emantipl@fcc.gov
18.
Maurer**
Stew
Ind Consultant
US
maureremf@hotmail.com
19.
Morrissey
Joe
Motorola
US
ejm037@email.mot.com
20.
Owen
Russell
FDA/CDRH
US
Rd.owen@icnirp.org
21.
Petersen
Ron
Ind Consultant
US
r.c.petersen@ieee.org
22.
Reilly
J Patrick
Metatec Assoc
23.
Sheppard
Asher
Ind Consultant
US
ashersheppard@compuserve.com
24.
Swicord
Mays
Motorola
US
ems029@email.mot.com
25.
Tell
Richard
Ind Consultant
US
rtell@radhaz.com
26.
Ziskin
Marvin
Temple Univ
US
ziskin@temple.edu
jpatrickreilly@erols.com
*1st day only
**2nd day only
20
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
ATTACHMENT 2
IEEE/ICES SCC-28 Subcommittee 4
5th Revision Working Group Meeting Agenda
Safety Levels with Respect to Human Exposure to Radio Frequency
Electromagnetic Fields, 3 kHz to 300 GHz
April 8-9, 2002
8:00 am – 5:00 pm
Federal Communications Commission
7th Floor South Conference Room (7-B516)
445 12th Street, S.W., Washington, D.C.
Contact: Robert Cleveland
202-418-2422
April 8, 2002
8:15 – 9:40
1.
Call to Order
2.
Introduction of Those Present
3. Approval of Agenda
4. Approval of Minutes of the January 10-11, 2002 Plantation, Florida Meeting
5. Chairmen’s report (Chou/D’Andrea)
a)
SC4 approved guidelines and time schedule
b) AF Workshop
c)
BEMS special issue
6. Risk Assessment Working Group Report (Tell)
7. Mechanism Working Group Report (Sheppard)
8 Literature Evaluation Working Group Reports
a)
Literature Surveillance Group Report (Heynick)
b) Engineering (Hurt)
c)
In Vivo (Blick)
d) In Vitro (Meltz)
e)
Epidemiology (Ruscio)
10:00- 12:00
9. Report of responses to the 23 key questions and issues (Tell, D’Andrea and Chou)
10. WHO Temperature Workshop report (Joe Elder)
12:00-1:00 Lunch at FCC cafeteria (both days)
1:00-5:00
11. Normative Section Discussions (Tell)
a)
one or two tiers
b) 1 gram or 10 gram
c)
SAR levels for partial body exposure (peak SAR)
d) levels for WB exposure (average SAR)
21
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
ATTACHMENT 2
April 9, 2002
8:15-10:00
12. Finish off and summarize Normative Section
13. Informative Section discussions
c)
Annex A (approach to standard revision). (Swicord and Erdreich)
d) Annex B (selecting an adverse effect - summary of the literature evaluation results (Sheppard)
e)
Annex C (explanation of maximum permissible exposure limits). (Tell)
f)
Annex D (Elder)
g) Annex H (DeFrank)
14. White paper reports
4:00
15. Business from last meeting
16. New Business
17. Date and Place of Next Meeting
a)
Subcommittee 4 meeting in Quebec, Canada, June 29, 2002
b) 6th meeting of the Revision Working Group, Washington DC, September 2002.
5:00
18. Adjourn
22
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
ATTACHMENT 3
IEEE/ICES SCC-28 Subcommittee 4
th
4 Revision Working Group Meeting Summary
(Revised by SC4 on January 19, 2002)
January 10-11, 2002
Fort Lauderdale, Florida
Participants:
Adair, Blick, Chou (Chair), Cleveland, Curtis (1st day only), D’Andrea, Elder, Heynick, Hurt, Kantner, Kuster,
Lang, Leonowich, Lotz, Morrissey, Owen, Petersen, Roberts, Sheppard, Swicord, Tell, Ziskin.
Based on our current understanding and pending the conclusion of the review and white paper process, the
consensus of the Revision Working Group is as follows:
1. The RF safety standard should be based on science.
2. RF safety standard revision should be derived from peer-reviewed publications and
documents that are reviewed by the SC4.
3. The adverse effect level remains at 4 W/kg subject to revision following completion of the
literature evaluation and white papers.
4. The maximum exposure limits should be based on established adverse effects after inclusion
of an appropriate safety factor(s).
5. Safety factor(s) should consider uncertainties in the biological database (e.g., unknown health
consequences, measurements, environmental conditions, exposure duration, individual
variability, and other factors.)
6. Non-thermal RF biological effects have not been established and none of the reported nonthermal effects are proven adverse to health (does not apply to electro-stimulation). Thermal
effect is the only established adverse effect.
7. The microwave hearing effect is not adverse and should not be used for setting the peak
power limit.
8. The shape and size of the averaging volume and the peak SAR limit will be determined after
the WHO temperature workshop in March are still to be determined. The important end
point is the temperature change.
9. RF standard should be harmonized with other international standards to the extent where
scientifically defensible.
10. Rationales must be documented for all changes relative to the current standard.
11. The editorial committee wWill add in the informative section a paragraph dealing with
potentially sensitive subpopulations, such as children.
12. Reconsider Keep the two-tier approach (whole body average SAR 0.4 and 0.08 W/kg) and
leave, the peak SAR value and the averaging volume. blank, which are to be decided after the
WHO temperature workshop results become available.
23
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Time schedule:
1/19/2002 SC4 meeting, San Antonio
Discuss the consensus of 4th Revision WG
3/31/2002 Editorial Committee
Distribute 2nd draft to RWG
4/8-9/2002 5th RWG meeting, DC
Discuss 2nd Draft
4/30/2002 Editorial Committee
Distribute 3rd draft to RWG
5/15/2002 RWG
RWG comments back to editor
5/31/2002 Editorial Committee
Distribute 4th draft to SC4
6/28/2002 SC4 meeting, Quebec
Discuss 4th draft
8/15/2002 Editorial Committee
Distribute 5th draft to RWG
9/2002
6th RWG meeting
Discuss and revise 5th draft
10/2002
Editorial Committee
Distribute 6th draft to SC4
11/2002
SC4 meeting
Discuss 6th final draft
12/31/2002
SC4
SC4 balloting
24
ATTACHMENT 4
Attachment 5
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Action Item
Owner
Due Date
1.
The authors of each of the
white papers are to be sent the
scores of those relevant papers
that have undergone a
complete review.
Blick
Before June
2.
The RAWG is to meet before
the Quebec City meeting to
resolve the issue of how to
proceed.
Tell
Before June 27th
3.
Each author of a white paper is White paper
authors
to send a list of those papers
considered important to Tell.
The list is to be compared with
the results of the reviews
(database).
Before June 27th
4.
RWG
The working group is to
decide on a definition of the
term “ safety factor” before the
June meeting.
Before June 27th
5.
Heynick is to send Tell a
definition for the term “nonthermal” – including
exceptions.
Heynick
Before June 27th
6.
Sheppard and Swicord will
address the SAR versus
temperature issue to resolve
the 1 versus 10 g averaging
mass issue.
Sheppard and
Swicord
Before June 1st
7.
Reilly is to review Draft 2 of
the C95.1 revision and
recommend any necessary
changes to ensure consistency
between C95.1 and C95.6 in
the transition region.
Reilly
Before June 27th
8.
Authors of the white papers are White paper
authors (all)
to coordinate the completion
of Annex B.
Before June 27th
9.
Adair is to confirm the squirrel
Before BEMS
Adair
25
Resolution
Attachment 5
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
monkey data for WBA SARs
and ∆Thypothalamus.
10.
D’Andrea is to look into data
from the rhesus monkey for
head-only RF exposures and
∆Tbrain.
D’Andrea
Before BEMS
11.
Adair is to ask Foster if his
recent paper (or book chapter)
paper on the basis of setting
RF standards could be posted
on the SC-4 website.
Adair
Before June 1st
12.
Lotz is to review the
Thermoregulation White
Paper.
Lotz
Before June 1st
13.
Chou is to contact Black
regarding his review of the
Thermoregulation White
Paper.
Chou
Before June 1st
14.
Reilly is to send data,
including pulse levels, to
Chou, D’Andrea and Tell.
Reilly
Before June 1st
26
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Attachment 6
General Comments, Concepts, Issues Related to Selection of One vs. Two Tiers
Based on e-mail submissions
Summarized by Richard A. Tell
March 28, 2002
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
Terminology problems: E.g., environmental standard vs. environmental exposure
IEEE presumably advocates harmonization yet many respondents exhibit expressions of
superiority of IEEE. IEEE colleagues very defensive in comments, not helpful.
Compile list of differences in approach/philosophy and limits and pros and cons for ICES vs
ICNIRP.
Need to define exactly what exposure duration standard is applicable to. This will help
determine exposure limits.
Majority view should be used in determining revision of standard. It is difficult to get
consensus on important issues.
Everyone believes that limits of present knowledge be stated up front along with needs for
further research. State implicit and explicit assumptions made.
Retain word “safety” in title of standard. Standard will not be credible if claimed to be a
“health protection” standard.
Standards harmonization should work both ways, but don’t count on this!
Defining controlled and uncontrolled environments is better than defining occupational and
public exposures, but is wrong way to justify an added safety factor.
Time weighted averages should not be used in standard.
Set a single level of exposure and allow relaxation under controlled conditions.
Remove present links between partial body and whole body exposure.
ICNIRP cannot change in short to medium term. Too much engagement with political
process.
Need to know probability of adverse reaction to specify safety factors.
TWA is not applicable to sub-threshold exposures.
Standard should be based on biological (or health) effects rather than dosimetric parameters.
Any guidelines are premature until review process is completed.
General population rationales (e.g., infants, elderly, infirm, chronic vs. acute exposures) still
valid.
Treating everyone as health military or industrial workers not valid health protection option.
Need consensus on real hazard threshold to declare a single tier standard.
Most people, most of the time are exposed to only very weak fields. Thus, there is no need to
develop a standard that offers more protection to them.
Standard should protect against all known adverse regardless of mechanism.
Occupationally exposed persons should have RF safety program since they are more likely to
be exposed to RF fields exceeding the limit.
A single tier standard should contain a RF safety program.
Persons exposed to a higher tier should have benefit of medical fitness testing.
Unnecessarily large safety factors are not appropriate and can actually lead to increased risk
for community.
RF safety program is appropriate with occupational scenarios.
27
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Attachment 6
28. Standard should not contain a safety factor to account for uncertainty in exposure
assessments.
29. Can not have a “scientifically based” standard if there is no science for second tier.
30. Precise definition of what the standard protects against is necessary before question of one
vs. two tiers can be answered.
31. Don’t see how having a “safety” standard and separate “environmental” standard would
make any difference.
32. Standard should protect against all known adverse regardless of mechanism.
33. There is a need to distinguish between (a) whether different people are enough different in
their susceptibility to RF to necessitate different exposure limits and (b) the fact that some
people have greater opportunity of exposure to stronger fields.
28
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Attachment 6
Specific comments supporting a single tier standard
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
No support for uncertainty in knowledge of adverse effects sufficient to warrant second,
lower tier.
No one has sustained a serious injury from RF exposures at first ANSI standard MPE of 10
mW/cm2.
Little or no hard evidence of difference in population groups (why IEEE used environments
rather than populations).
0.4 W/kg is very conservative, small fraction of BMR, children even less susceptible (higher
BMR). Could be helpful for elderly with low BMRs.
Strong scientific evidence that present upper tier is safe for all.
No need for safer than safe, socio-political lower tier in a science based standard.
Adjacent standards should be seamless with revised standard for RF. (ELF and laser
standards are one tier).
0.4 W/kg is likely adequate for “most sensitive humans”.
“Heat energies” added by 0.4 W/kg SAR are miniscule, even for those with power
thermoregulatory systems.
Certain subgroups are not more at risk for RF fields (however, need provision for difference
in children, women and men for currents, shock voltages).
RF fields, below controlled limits are not cumulative.
Likelihood of finding a new, significant adverse effect is well below level of acceptability;
no extra safety factor is needed to protect public against unestablished low level effects.
Sound, logical reasons for moving to a one-tier standard will, eventually, be equally
compelling to other standards bodies and, hence, retention of current two tiers for sake of
“consistency” with other standards is unnecessary.
Lower exposure limits are not necessary for people who are not aware of how to minimize
their exposure since exposures below 0.4 W/kg limit are not expected to have any cumulative
effect.
A second lower tier to placate pressure groups is not based on scientific grounds.
Simplicity.
Honesty and transparency.
No evidence that 0.4 W/kg is not protective of all individuals.
Make one tier standard only a “safety” standard, not an “environmental” standard.
The acceptability of a single-tier standard hinges on the exposure limit selected.
Applying overly conservative safety factors to derive MPE limit for a single-tier RF
standard, when trying to err on the safe side for lack of good technical data that would tell us
what the safety factor should really be could result in unnecessary impact when
implementing the standard.
Single tier would remove confusion among occupationally exposed individuals who can’t
understand why they are less susceptible to RF field hazards than their family members at
home.
If same behavioral disruption data are used as in present standard, argument can be made
that 99% of animals would exhibit threshold at 3.0 W/kg or greater (i.e., only 1% of animals
would exhibit a threshold less than 3.0 W/kg). Safety factor of unity would be appropriate to
account for individual variability. If behavioral disruption is assumed to be related to body
29
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Attachment 6
heating, and humans exhibit superior thermoregulation than animals, safety factor of unity is
also appropriate in translating to man. Only safety factor necessary is to account for
translation from short term exposures in animal data to prolonged exposure in humans.
30
Approved SC-4 RWG Minutes – April 8-9, 2002 Meeting
Attachment 6
Specific comments supporting a two tier standard
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Two tier concept is already heavily endorsed internationally, nothing can change in near to
medium term.
Medical studies indicate that persons in general public suffer from impaired
thermoregulatory capabilities, poor circulatory capabilities, etc.
Cannot treat everyone as healthy military or industrial workers.
Lack of new information that would defend a relaxation of safety factor of 50, unless we can
show that 0.4 W/kg already incorporates necessary uncertainty factor.
Offers more flexibility in dealing with scientific uncertainty.
Extrapolation of acute effects data to chronic exposure conditions.
Extrapolation of animal data to humans in prolonged exposure situations.
Variation in susceptibility (response/sensitivity) among individuals.
Incomplete data bases.
Uncertainty in selection of effects bases, inability of any single study to adequately address
all possible adverse outcomes.
OHSA only takes action against employers for exposures in excess of tier based on known
adverse effects (allowing for an appropriate safety factor). If lower tier is based only on
“known adverse effects”, then this opens the door to application of precautionary principle
since some effects, not known to be adverse could turn out to be adverse.
Second tier should be declared as purely precautionary, not science.
Unlikely that US Federal government would adopt a single tier standard since it might
appear less protective of public health than others.
Socio-politically, two tiers are needed for acceptance.
31
32
ATTACHMENT 8
One vs. Two Tier Standard Issues
Need to precisely define whether the effect
being protected against is adverse, potentially
adverse or a precursor of a potentially adverse
effect or simply, discomfort.
If behavioral disruption in animals is used as the
end point to protect against, then the same
evaluation in humans is necessary to ensure
that this same end point is actually protected
against.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Standard should define safe exposure levels for
RF fields, whether for occupational exposures or
public exposures, whether one or two tiers.
Exposure limits should not be related to fact that:
(1) most people, most of the time, are only
exposed to very weak fields or that
(2) very few people, some of the time, are
exposed to very intense fields.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
This means that the standard should be based
on the “worst-case” or maximal possible
exposure assumptions, i.e., exposure is continual
(ongoing, albeit sometimes intermittent, but it
does not cease), meaning “24/7” and long-term,
that is, many years including life long.
The standard should account for RF exposure
being added to the normal activity and
background environmental conditions where, in
some individuals at some times, it might
“interfere with concentration and fine motor
performance.”
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Number exposed
Generally, as exposures increase in value, the
number of people exposed to these higher fields
decreases sharply such that a finite, non-zero
number results that is equal to the number of
workers that are routinely exposed to very
strong fields.
Range of
typical,
environmental
exposures
Range of
typical,
occupational
exposures
Finite, nonzero
population
Log Exposure
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Percent responding
Cumulative %
responding ≤ SAR
Need estimates of statistical distribution of SAR
thresholds for whatever is the “effect” or
“effects” being protected against. This will
permit a quantitative approach to setting safety
factors.
SAR
90%
50%
10%
SAR
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Food for Thought
The physiological basis regarding an assumed absence of
obvious adverse effects from short term exposures to 0.4 W/kg is
stronger and more supportable than 4 W/kg and a 10 fold safety
factor.
This is because a ten fold safety factor is not suitable or
defensible for an exposure that is definitely adverse over long
term.
There are, in addition, studies of laboratory animals to support the
weight of evidence that long-term exposure to 0.4 W/kg does not
cause cancer or adverse organic toxicity or pathology.
This means that a smaller safety (uncertainty factor) could be
used to derive continuous exposure limits from 0.4 W/kg for
continuous exposure in uncontrolled environments.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
The assumption in the present standard, that
behavioral disruption is a precursor to a
hazardous health effect, if properly translated to
human responses, could possibly result in lower
SAR values than found for animals. This is due
to the observation of the exquisite ability of
humans to sense comfort and discomfort and
their ability to express this sensation. If
behavioral disruption is, in fact, the critical
endpoint to assess, then we need human
studies of behavioral disruption as a function of
WBA SAR and localized SAR.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Observation of no measurable increase of body
core temperature in humans exposed to intense
RF fields with consequent thermoregulatory
responses (e.g., sweating) is not adequate to
justify that a given SAR is innocuous to
humans.
How do such observations relate to behavioral
disruption? (Behavioral disruption has not been
evaluated in humans and there are no explicit
data indicating that it can only occur at higher
SARs than in animals).
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Innocuous
1 : producing no injury : HARMLESS
2 : not likely to give offense or to arouse
strong feelings or hostility :
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
There are different expressions of behavioral
disruption.
Which ones are to be considered adverse or
potentially adverse and which ones not?
This needs to be defined.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
A standard:
(1) should ensure that the exposed subject will
not suffer an adverse health effect from the
exposure, even for prolonged exposures, and,
(2) should not invoke sensations of discomfort
for those individuals not made familiar with the
potential for discomfort and possible associated
implications.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
It could be argued that a two tier standard could
be based on the upper tier protecting against
hazardous effects (in controlled environments)
and the lower tier protecting against sensations
of discomfort (as in thermal comfort and
discomfort) (in uncontrolled environments).
Only persons provided with RF safety
awareness training and awareness of potential
exposures that could result in discomfort (in
controlled environments) would be permitted to
be exposed above the lower tier.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Question:
For the most feeble person imaginable, could
0.4 W/kg WBA SAR cause ANY anticipated
harmful stress, e.g., cardiovascular,
thermoregulatory, or other sensory stress?
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
One vs. Two Tier StandardATTACHMENT
Issues8
Equilibrium Core Temperature vs. SAR
and Ambient Air Temperature
50% relative humidity, 0.5 m/s air speed, fatigues, at rest
46.0
45.0
Core temperature (C)
44.0
43.0
42.0
41.0
45o
42.5o
40.0
40o
37.5o
o
35
30o
25o
39.0
38.0
Computed for
an 80 kg man
20o
37.0
36.0
0
1
2
3
4
5
SAR (W/kg)
Calculations based on Givoni, B. and R. F. Goldman (1972). Predicting rectal temperature response to work,
environment, and clothing. J. Applied Physiology, Vol. 32, June, pp. 812-822.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
One vs. Two Tier StandardATTACHMENT
Issues8
o
SAR to Achieve 1 Core Temperature Increase vs.
Ambient Air Temperature
50% relative humidity, 0.5 m/s air speed, fatigues, at rest
4.0
Whole body SAR (W/kg)
3.5
3.0
Computed for
an 80 kg man
2.5
2.0
1.5
1.0
0.5
0.0
20
25
30
35
40
45
50
Ambient air temperature (C)
Calculations based on Givoni, B. and R. F. Goldman (1972). Predicting rectal temperature response to work,
environment, and clothing. J. Applied Physiology, Vol. 32, June, pp. 812-822.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Reporting of Sensation of Discomfort vs. Air Temperature
Percentage uncomfortable (%)
100
Subject at rest, 1 met
90
80
40% RH
40 ft/min
0.5 clo
70
60
50
40
30
20
10
0
60
65
70
75
80
85
90
95
Air temperature (F)
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Predicted Percentage Uncomfortable vs. Metabolic Rate
Percent uncomfortable (%)
70.0
Ta= 85F
40% RH
40 ft/min
0.5 clo
60.0
50.0
40.0
30.0
20.0
1.0
1.2
1.4
1.6
1.8
2.0
Metabolic rate (mets)
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Predicted Percentage Uncomfortable vs. Metabolic Rate
Percentage uncomfortable (%)
40.0
35.0
Ta= 80F
40% RH
40 ft/min
0.5 clo
30.0
25.0
20.0
15.0
10.0
5.0
0.0
1.0
1.2
1.4
1.6
1.8
2.0
Metabolic rate (mets)
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Skin Blood Flow vs. Air Temperature
Skin blood flow (pints/ft2/hr)
14
12
40% RH
40 ft/min
0.5 clo
1.4 met
10
8
6
1.0 met
4
2
0
65
70
75
80
85
90
95
100
Air temperature (F)
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Influence of Metabolic Rate on Percentage of Population Reporting Discomfort
Percentage uncomfortable (%)
100
40% RH
40 ft/min
0.5 clo
1 met
90
1.1 mets
80
1.2 mets
70
1.3 mets
60
1.4 mets
50
1.5 mets
40
1.6 mets
30
1.7 mets
1.8 mets
20
1.9 mets
10
2.0 mets
0
80
85
90
95
Air temperature (F)
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Observation:
•A WBA SAR in range of 0.1 W/kg will not result
in any significant increase of discomfort due to
body heating under virtually any imaginable
environmental conditions or levels of exertion.
•Ratio of WBA SARs associated with protection
against potentially harmful long-term effects and
predicted measures of discomfort are in range
of a factor of 3 to 4 times.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC
ATTACHMENT 8
One vs. Two Tier Standard Issues
Serious need to address how nonuniform
exposures should be limited. The present
approach is based essentially on whole-body
dosimetry considerations and the presumption
that the biological effect observed at a given
WBA SAR incorporates any responses to
associated nonuniform SAR distributions. The
present approach is not directly related to
biological responses to localized SAR.
Presented by Richard A. Tell and Linda S. Erdreich
for Discussion at IEEE Standards Revision Working Group Meeting, April 8-9, 2002,
Washington, DC