This new “IEEE
Standard for Safety Levels with Respect to Human Exposure to Radio
Frequency Electromagnetic Fields, 3 kHz to 300 GHz”
published on April 19, 2006 is a revision of C95.1-1991 (1999 edition)
and C95.1b-2004 “Amendment 2: Specific Absorption Rate (SAR) Limits
for the Pinna.” The revision is based on scientific and medical
literature published through December 2003, but several 2004 and 2005
papers are included. The
document includes a comprehensive review of about 1300 references,
including studies that involve low level exposures where increases in
temperature could not be measured or were not expected (i.e.,
“non-thermal” effects). The revised standard reflects new insights
gained from improved experimental and numerical methods and a better
understanding of acute and chronic radiofrequency (RF) electromagnetic
field exposure effects on animals and humans.
The weight of evidence
approach was used for the standard development. This process includes
evaluation of the quality of test methods, the size and power of the
study designs, the consistency of results across studies, and the
biological plausibility of dose-response relationships and statistical
associations. C95.1 Standard’s major revision includes the new
recommendation of peak spatial average SAR of 2 and 10 W/kg averaged
over 10 g tissue for the lower and upper tier, respectively. This
revision resolves a major harmonization issue with RF standards.
RF Safety concerns started in the 50s with exposure to radars, then
radio and TV broadcasting in the 60s, microwave ovens in 70s, police
radar in 80s and then most recently wireless communications. Although
mobile phones are a new concern, remember that two-ways radios with
much higher power have been used by security professionals for more
than 40 years. The major difference in ionizing and non-ionizing
radiation can be seen from the electromagnetic spectrum. The well
known cumulative damaging effects of ionizing radiation do not occur
at wavelengths longer than those in the UV, including the sunlight.
Over the past more than 50 years, large data base has been accumulated.
Currently there are about 1600 peer-reviewed articles in the WHO
database relating to the RF biological effects. On the mobile
telephony alone, there have been about 500 papers published and
another 200 to be published. The research subjects consist of
epidemiological, human, animal and in vitro cell studies. The
complexities of both engineering and biological studies are pointed
out in the C95.1 Standard, which are the major reasons why there is so
much noise in research results. The WHO stated that scientific
knowledge in this area is now more extensive than for most chemicals,
and concluded that current evidence does not confirm the existence of
any health consequences from exposure to low level electromagnetic
fields.
<http://www.who.int/peh-emf/about/WhatisEMF/en/index1.html>
In terms of research, WHO estimated $250 M already spent on mobile
telephony bioeffect research, and $130 M more are for on going and
future studies. The strongest evidence is from animal cancer studies.
The weight of scientific evidence in 41 studies shows that RF
exposure up to lifetime exposure (2 years) does not adversely affect
carcinogenic processes (initiation, promotion or co-promotion) at
whole-body dose rates up to 4 W/kg and localized dose rates up to 2.3
W/kg. Long term animal studies provide no supportive evidence of low-level
non-thermal effects. Short term animal and in vitro studies showing
positive effects, even if proven repeatable, are not consistent with
the lifetime exposure studies.
In the past 10 years, there have been more than 20 independent expert
group reviews globally. The general conclusion of reviews is that
there is no credible evidence that RF exposures within internationally
accepted limits cause any adverse health effects, but more research is
needed. However, it was pointed out that one can never prove the null
hypothesis and thus one can never prove that something is absolutely
safe. Basically, there is no known mechanism for adverse health
effects of RF exposure other than thermal. Due to the current
extensive database, it is unlikely that results of ongoing studies
will shift the weight of evidence on health effects.
International measurement methods for measuring mobile phone emission
are available. With proper regulation, all phones should comply with
international exposure limits. Residential and office building RF
exposures are in general lower than 1% of ICNIRP or IEEE limits,
similar to that of radio and TV broadcast. Roof top antenna
installation does not beam energy downward and therefore there is no
need for concern. WHO Fact Sheet #304 (May 2006): Electromagnetic
fields and public health: Base stations and wireless technologies,
states “Considering the very low exposure levels and research results
collected to date, there is no convincing scientific evidence that the
weak RF signals from base stations and wireless networks cause adverse
health effects.” <http://www.who.int/mediacentre/factsheets/fs304/en/index.html>
In conclusion: 1) RF electromagnetic waves are not nuclear radiation,
2) The only proven RF interaction mechanism is thermal effect, 3)
Exposure levels near base stations are very low, 4) Both ICNIRP and
IEEE standards provide ample protection for all populations.
This new “IEEE
Standard for Safety Levels with Respect to Human Exposure to Radio
Frequency Electromagnetic Fields, 3 kHz to 300 GHz”
published on April 19, 2006 is a revision of C95.1-1991 (1999 edition)
and C95.1b-2004 “Amendment 2: Specific Absorption Rate (SAR) Limits
for the Pinna.” The revision is based on scientific and medical
literature published through December 2003, but several 2004 and 2005
papers are included. The
document includes a comprehensive review of about 1300 references,
including studies that involve low level exposures where increases in
temperature could not be measured or were not expected (i.e.,
“non-thermal” effects). The revised standard reflects new insights
gained from improved experimental and numerical methods and a better
understanding of acute and chronic radiofrequency (RF) electromagnetic
field exposure effects on animals and humans.
The weight of evidence
approach was used for the standard development. This process includes
evaluation of the quality of test methods, the size and power of the
study designs, the consistency of results across studies, and the
biological plausibility of dose-response relationships and statistical
associations. C95.1 Standard’s major revision includes the new
recommendation of peak spatial average SAR of 2 and 10 W/kg averaged
over 10 g tissue for the lower and upper tier, respectively. This
revision resolves a major harmonization issue with RF standards.
RF Safety concerns started in the 50s with exposure to radars, then
radio and TV broadcasting in the 60s, microwave ovens in 70s, police
radar in 80s and then most recently wireless communications. Although
mobile phones are a new concern, remember that two-ways radios with
much higher power have been used by security professionals for more
than 40 years. The major difference in ionizing and non-ionizing
radiation can be seen from the electromagnetic spectrum. The well
known cumulative damaging effects of ionizing radiation do not occur
at wavelengths longer than those in the UV, including the sunlight.
Over the past more than 50 years, large data base has been accumulated.
Currently there are about 1600 peer-reviewed articles in the WHO
database relating to the RF biological effects. On the mobile
telephony alone, there have been about 500 papers published and
another 200 to be published. The research subjects consist of
epidemiological, human, animal and in vitro cell studies. The
complexities of both engineering and biological studies are pointed
out in the C95.1 Standard, which are the major reasons why there is so
much noise in research results. The WHO stated that scientific
knowledge in this area is now more extensive than for most chemicals,
and concluded that current evidence does not confirm the existence of
any health consequences from exposure to low level electromagnetic
fields.
<http://www.who.int/peh-emf/about/WhatisEMF/en/index1.html>
In terms of research, WHO estimated $250 M already spent on mobile
telephony bioeffect research, and $130 M more are for on going and
future studies. The strongest evidence is from animal cancer studies.
The weight of scientific evidence in 41 studies shows that RF
exposure up to lifetime exposure (2 years) does not adversely affect
carcinogenic processes (initiation, promotion or co-promotion) at
whole-body dose rates up to 4 W/kg and localized dose rates up to 2.3
W/kg. Long term animal studies provide no supportive evidence of low-level
non-thermal effects. Short term animal and in vitro studies showing
positive effects, even if proven repeatable, are not consistent with
the lifetime exposure studies.
In the past 10 years, there have been more than 20 independent expert
group reviews globally. The general conclusion of reviews is that
there is no credible evidence that RF exposures within internationally
accepted limits cause any adverse health effects, but more research is
needed. However, it was pointed out that one can never prove the null
hypothesis and thus one can never prove that something is absolutely
safe. Basically, there is no known mechanism for adverse health
effects of RF exposure other than thermal. Due to the current
extensive database, it is unlikely that results of ongoing studies
will shift the weight of evidence on health effects.
International measurement methods for measuring mobile phone emission
are available. With proper regulation, all phones should comply with
international exposure limits. Residential and office building RF
exposures are in general lower than 1% of ICNIRP or IEEE limits,
similar to that of radio and TV broadcast. Roof top antenna
installation does not beam energy downward and therefore there is no
need for concern. WHO Fact Sheet #304 (May 2006): Electromagnetic
fields and public health: Base stations and wireless technologies,
states “Considering the very low exposure levels and research results
collected to date, there is no convincing scientific evidence that the
weak RF signals from base stations and wireless networks cause adverse
health effects.” <http://www.who.int/mediacentre/factsheets/fs304/en/index.html>
In conclusion: 1) RF electromagnetic waves are not nuclear radiation,
2) The only proven RF interaction mechanism is thermal effect, 3)
Exposure levels near base stations are very low, 4) Both ICNIRP and
IEEE standards provide ample protection for all populations.
C-K. Chou, Ph.D.
Chairman, Technical Committee 95
Institute of Electrical and Electronics Engineers
International Committee on Electromagnetic Safety
[email protected]
Additional Information: PCC.II has a
Rapporteur Group on the Technical and Regulatory Aspects Related
to the Effects of Electromagnetic Non-Ionizing Emissions that is
considering this issue. The Rapporteur is Mr. Héctor Carril
([email protected]).
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