IET Are There Harmful Biological Effects 2014

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Position
Statement

Are there harmful Biological
Effects of Low-Level
Electromagnetic Fields at
frequencies up to 300 GHz?
2014 Position Statement provided by the Institution of Engineering and Technology

www.theiet.org/factfiles

About This Position Statement

Contents

The Institution of Engineering and Technology (IET) acts
as a voice for the engineering and technology professions
by providing independent, reliable and factual information
to the public and policy makers. This position statement
aims to provide an accessible guide to the findings of the
IET’s Biological Effects Policy Advisory Group (BEPAG).
This position statement encapsulates the IET’s position
on the possible harmful biological effects of low-level
electromagnetic fields at frequencies up to 300 GHz.
For more position statements and factfiles on engineering
and technology topics please visit www.theiet.org/factfiles

Summary�������������������������������������������������������������������������� 3
Introduction���������������������������������������������������������������������� 5
Epidemiology�������������������������������������������������������������������� 7
Human Studies��������������������������������������������������������������� 10
Animal Studies���������������������������������������������������������������� 10
Cellular Studies��������������������������������������������������������������� 11
Mechanisms of interaction���������������������������������������������� 11
Conclusions�������������������������������������������������������������������� 12
Appendix������������������������������������������������������������������������ 13

The Institution of Engineering and Technology
The IET is a leading professional body for the engineering
and technology community, with more than 160,000
members in 127 countries, and offices in Europe, North
America, and the Asia-Pacific region.
As engineering and technology become increasingly
interdisciplinary, global and inclusive, the IET reflects
that progression and welcomes involvement from, and
communication between, all sectors of science, engineering
and technology.
The IET is registered as a Charity in England & Wales (no
211014) and Scotland (no SC038698).
For more information please visit www.theiet.org
© The IET 2014

Enquiries to
IET Policy Department
Telephone: +44(0)1438 765690
Email: [email protected]

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

2

Summary
The Institution of Engineering and Technology (IET)
has a special interest in any possible health effects of
both occupational and general-population exposure to
electromagnetic fields (EMFs) because of its leading role
in engineering and technology, particularly in all aspects
of electronic and electrical engineering. The IET remains
determined to be at the forefront of the examination of the
scientific evidence for any such effects and thus identify
any emerging hazards as early as possible. To this end
it maintains its Biological Effects Policy Advisory Group
(BEPAG) on low-level EMFs.
BEPAG has concluded in this report that the balance of
scientific evidence to date does not indicate that harmful
effects occur in humans due to low-level exposure to EMFs.
Our examination of the peer-reviewed literature published
in the last two years has not justified a change in the overall
conclusions published in our previous report in May 2012.
Power Frequencies
At power frequencies (50 or 60 Hz, as used
for electricity supply), the balance of evidence
from the large body of scientific papers built
up over several decades suggests that the
existence of harmful health effects from environmental levels
of exposure remains unsubstantiated. There is no generally
accepted experimental demonstration of any biological effect,
harmful or otherwise, due to such fields. Pooled analyses of
epidemiological studies have shown an association between
childhood leukaemia and higher levels (greater than about
0.4 microteslas) of power-frequency magnetic fields in the
home. However, in the absence of convincing mechanistic
and experimental evidence, these epidemiological findings
do not provide good grounds for concluding that there is
a causal relationship. Problems of study design including
selection bias and confounding remain a possible explanation
of these results. A major epidemiological study published
in early 2014 suggests that the risk of childhood leukaemia
associated with living near high-voltage power lines has
decreased over the past forty years and is no longer elevated,
despite the magnetic fields from the lines having increased
along with electricity consumption. This finding makes a
link between the fields from the power lines and leukaemia
significantly less likely and, if confirmed by other studies,
indicates potential new avenues for research such as the
effect of population changes on the incidence of the disease.
Higher Frequencies
At higher frequencies (such as those
used for mobile communications),
the existing data do not provide persuasive evidence that
harmful health effects exist. Perhaps the greatest area of
public concern remains the possibility of adverse health
effects from long-term mobile phone use. Mobile phones
have been in widespread use for some 20 years and
hence epidemiological studies of long-term health effects
are currently limited to this time frame. The international

collaborative INTERPHONE study, carried out in 13
countries, remains the largest analysis of long-term users
to date. The INTERPHONE Study Group concluded that
its results do not show an increase in brain tumours that
could be interpreted as causal, but that possible effects
of long-term heavy use of mobile phones require further
investigation. Recent analyses of historical brain-tumour rates
have not observed increases commensurate with the rapid
expansion of mobile-phone use since the early 1990s, which
suggests, although the length of time before any such effects
would appear remains uncertain, that some of the more
extreme epidemiological findings are implausible.
The Group noted the publication of the final report of the
UK Mobile Telecommunications Health Research (MTHR)
programme in early 2014, summarising the findings of its
studies from 2001-2012. The programme funded 31 projects
which have resulted in almost 60 papers in peer-reviewed
science journals. Focused largely on mobile phone and
TETRA signals the report concludes that none of the studies
showed effects of the signals being tested. In particular
they single out their negative studies on the effects of signal
modulation as having ‘extremely important implications’ and
‘constitute a substantial body of evidence that modulation
does not play a significant role in the interaction of
radiofrequency fields with biological systems’.
The ubiquitous nature of our exposure to mobile phones
means that, even if the risk to individuals is low, a large
number of people could still experience health effects.
However, experimental studies have still failed to demonstrate
consistent effects, and no mechanism has been established
whereby low-level exposure to radio-frequency fields can
cause biological effects. Field levels from base stations, often
a cause of public concern, are broadly similar to those from
other broadcast radio-frequency sources such as television
and radio transmitters and are many times lower than
the peak values experienced when using a mobile-phone
handset.
Robustness of the scientific literature and its reporting
Heavily publicised experimental studies that fail replication,
or for which replications are never attempted, continue to be
of concern. BEPAG remains of the view that scientists have
a responsibility to ensure that their findings are as robust
as possible before publication. It believes that pressures
on scientists to publish their work may encourage the
reporting of apparent effects that have not been adequately
investigated or reliably demonstrated. This phenomenon has
also been identified in the pharmacology and psychology
literature. Research institutions have a vested interest in
encouraging publications from their staff, but there is little
counterbalancing pressure to hold organizations to account
if such publications are found to be erroneous. BEPAG
recommends that all research institutions operate rigorous
internal quality control mechanisms to help mitigate this
problem.

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

3

BEPAG regards the independent replication of experimental
studies to be essential in order to improve the quality of
the existing literature and to verify any reported effect. It
recommends that isolated reports of biological effects or
epidemiological findings should initially be treated with
caution, until confirmed by independent groups. BEPAG
is also of the view that a journal which publishes a study
should be under an obligation to publish a subsequent wellconducted replication study even if this fails to confirm the
original findings.
BEPAG notes that the media still feature stories on EMF
health effects, sometimes giving them more prominence than
scientifically warranted, which heightens public concern.
Whilst understanding the drive for ‘good copy’ we believe the
emphasis should be on the word ‘good’ and that the media
must present a balanced view of scientific knowledge rather
than leading on sensationalist, but unreplicated or unverified,
reports.
New technologies
Technologies that produce electromagnetic fields are
continually evolving. Examples of this are 4G communication
systems, the roll-out of smart-metering technologies, and
non-contact charging devices. BEPAG will keep healtheffects papers concerning these technologies under review
along with the rest of the EMF literature.
In summary, the absence of robust new evidence of harmful
effects of EMFs in the past two years is again reassuring and
is consistent with our findings over the past two decades.
The widespread use of electricity and telecommunications
has demonstrable value to society, including numerous
health benefits. BEPAG is of the opinion that it remains
important that these factors, along with the overall scientific
evidence, should be taken into account by policy makers
when considering the costs and benefits of both the
implementation of any precautionary approaches to public
exposure and also in the development of public-exposure
guidelines.



Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

4

Introduction
The Institution of Engineering and Technology (IET) is
a registered charity in England and Wales (no. 211014)
and Scotland (no. SC038698) with more than 160,000
professionally qualified members worldwide, all of whom are
exposed to electromagnetic fields (EMFs, the electric and
magnetic fields created by the flow of electricity) in both their
professional and private lives. Some are particularly exposed
because of their employment in industries where there can
be relatively high levels of EMFs. Thus the IET has an interest
in possible health effects of EMFs on behalf of both its
members and the general public, and remains determined
to be at the forefront of the examination of the scientific
evidence for any effects of such exposures and thus identify
any emerging hazards as early as possible.
Given this situation the IET created the Biological Effects
Policy Advisory Group (BEPAG) on low-level electromagnetic
fields (a phrase used to describe relatively weak fields
that are lower than international exposure guidelines) in
November 1992. Its initial brief was to consider the possible
harmful effects of low-level low-frequency EMFs, primarily
at power frequencies (50 or 60 Hz), and it was tasked with
systematically assessing the scientific literature on behalf of
the public and the Institution’s members. BEPAG is made up
of experts in particular science and engineering disciplines;
some come from within the Institution’s own membership,
but some are drawn from other professions so as to obtain
the necessary specialist expertise. They are not remunerated
by the Institution for their work on its behalf and are
specifically required to not be influenced by the interests of
their employers, or other third parties.
BEPAG first reported in June 1994, and then approximately
every two years since that date. Its reports constitute the
IET’s position on these matters. In January 1998, the terms
of reference of BEPAG were extended to include frequencies

up to 300 GHz to reflect public concern over possible health
effects of radio-frequency fields, especially from mobile
phones. BEPAG has produced a factfile that introduces the
subject area and discusses some of the key public concerns
http://www.theiet.org/factfiles/bioeffects/emf-factfile-page.
cfm.
BEPAG uses refereed (also known as peer-reviewed)
scientific papers as its source material, in order that the
papers it reviews meet a minimum quality standard. These
are retrieved from a broad search of a range of electronic
databases. The methodology and sources used are
described in the Appendix.
BEPAG’s search criteria also identify papers concerning
the use of the earth’s magnetic field by animals, birds,
or fish for navigation. BEPAG considers it has now been
largely established that some species are indeed able to
detect and use the earth’s field. However, the mechanisms
needed for alternating fields (whether at 50/60 Hz or at radio
frequencies) to affect biological systems are likely to be very
different from those for static fields. BEPAG considers that
until any evidence emerges that the mechanisms involved
are transferable to alternating fields, the evidence on animal
navigation has no direct relevance to health effects in
humans. Hence BEPAG maintains a watching brief on that
literature rather than assessing each paper in detail.
Figure 1 shows the number of papers that provided the data
for each of the position statements since 2004. The overall
numbers have declined by about 35% since the peak in
2008. A comparison of numbers of papers for power and
mobile frequencies shows a recent decline in the former with
the latter remaining approximately constant. Approximately
40% of the papers fell outside these specific frequency
categories, predominantly split between other radio and low
frequencies.

1200

1000

Number of papers

800










600

400

200





















2012

2014



all relevant
papers



power
frequencies
only



mobile
frequencies
only

0
2004

2006

2008

2010
IET report year

Figure 1: Trend in EMF Biological Effect publications
Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

5

Figure 2 shows the split in papers based on their model type
or methodology. Cellular studies are the most numerous,
probably because of the relative ease of carrying out such
studies. The largest decline can be seen in the ‘physics’
category, which includes dosimetry studies and perhaps
reflects the absence of any new mechanisms of interaction
and the maturity of the topic of environmental dosimetry.
Animal studies have continued to increase steadily, which
may reflect the increasing number of papers on EMFs
originating from outside Europe and the U.S.A.

Figure 3 shows the continuing increase in the proportion
of mobile phone studies which report EMF effects. This is
perhaps surprising given that major research programmes
are predominantly reporting a lack of effects, and perhaps
reflects a trend towards smaller isolated studies with less
quality control. In the same period, power frequency papers
have decreased slightly.

350


300

Number of papers

250








200



150



100

50



































epidemiology



human



animal



cellular



physics


0
2004

2006

2008

2010

2012

2014

IET report year

Figure 2: Paper numbers by subject
100

90



80








70

60

%


50



no data for 2004 and 2006



power
frequencies



mobile
frequencies



40

30

20

10

0
2004

2006

2008
IET report year

2010

2012

2014

Figure 3: Percentage of papers reporting any EMF effect
Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

6

BEPAG continues to regard the fact that three out of every
four experimental studies report biological effects as striking.
If these findings are all robust they would suggest that such
effects are common and readily demonstrable. Whilst it is
traditionally assumed that those scientific studies which are
published in peer-reviewed literature are both robust and
replicable, this does not appear to be the case for the EMF
literature and is increasingly being challenged in other areas.
For example, recent comments from the pharmaceutical
industry suggest that over 60% of its studies fail to confirm
previous published work. Possible reasons cited include:
incorrect or inappropriate statistical analysis; insufficient
sample size; positive publication bias; and pressure to
publish combined with competition between scientists
leading to negligence. In the EMF literature attempts have
been made to replicate key studies, selected because
of their apparently sound methodology, robustness and
potential significance of findings (for example, the body of
work of the EMF Biological Research Trust: http://www.
emfbrt.org and of the Mobile Telecommunications and
Health Research (MTHR) programme: http://mthr.org.uk).
These attempts have been unable to confirm any of the
original reports. Such failed replications represent a major
challenge to the science of EMFs: the high proportion of
original experimental studies reporting effects suggests
that they are reasonably easy to find in most of the models
studied. However, the identification of even a single robust
effect which could be used as a starting point to determine
such factors as dose-response curves (the variation of
effect with exposure level and duration), whether the effects
are caused by electric or by magnetic fields, and to allow
investigation of the mechanism (how the effects are caused),
has proved problematic and, in the view of BEPAG, has yet
to be achieved. Arguably this remains the key goal for future
laboratory studies of EMF effects.
Because of the relatively clear distinction between lowfrequency and high-frequency studies, coupled with the
different types of sources involved and the likelihood that
any mechanisms of interaction are different, BEPAG has
continued to divide its assessment of the literature into these
two frequency bands without attempting to define them
rigidly. Particular focus has been given to power-frequency
(50/60Hz) fields and mobile-phone frequencies, as these are
the source of most public concern and represent the majority
of the papers evaluated. At frequencies above those used for
mobile communications there are few health-effects studies.
The literature has been further divided into five scientific
areas: epidemiology, human studies, animal studies, cellular
studies, and mechanisms of interaction, to reflect the main
categories of experimental studies.
The points below summarise the views of BEPAG on the
latest published peer-reviewed literature in these areas, and
on which, together with the content of previous reviews, the
conclusions in this statement are based.

Epidemiology
Epidemiology is the observational study of the occurrence
and distribution of diseases in populations. Exposure and
other conditions in EMF studies cannot usually be welldefined and controlled. Interpretation of findings needs to
consider potential biases in exposure assessment, selection
of study subjects, and data collection. Exposure assessment
is a particular challenge because direct measurements are
often not available or feasible and therefore exposure levels
need to be inferred from information such as job title, wiring
configuration of a house, or residential proximity to a power
line, radio or mobile-phone mast. An additional complexity
is that, in case-control studies, it is past rather than current
exposure that is relevant in terms of possible disease
causation and this past exposure has to be retrospectively
reconstructed. Recent studies have increasingly carried out
direct measurements in subjects’ homes, or work places,
which are an improvement, but this assumes that these
measurements are an accurate reflection of the relevant
exposure in terms of disease causation. Epidemiological
studies often have to rely on self-reported exposure
information, such as past mobile-phone use, which is open
to bias, and some rely on self-reported health effects which
may be biased due to study participation.
Childhood leukaemia
In 2001, the International Agency for Research
on Cancer (IARC) classified power-frequency
magnetic fields as possibly carcinogenic to
humans. This decision was strongly influenced
by epidemiological studies having observed increased risks
of childhood leukaemia at high levels (greater than about 0.4
microteslas) of magnetic-field exposure to power-frequency
EMFs. Studies published after 2001 have shown compatible
results to those published prior to then, although a very
large study in the United Kingdom published in early 2014
showed that the increased risk of childhood leukaemia
within 200 meters of the nearest overhead power line
was limited to cases diagnosed between 1960-1990 and
was not present thereafter. Some studies have suggested
that exposure to EMFs may adversely affect survival in
children already diagnosed with leukaemia, but a recent
study refuted these findings. Because a causative role of
magnetic fields is largely unsupported by laboratory studies
or a known mechanism, potential reasons for the EMFchildhood leukaemia association continue to be a common
and unanswered topic of research. A decline in leukaemia
risk in proximity to power lines over time as shown by the
recent UK study suggests the elevated risk is not related
to a physical effect of power lines but perhaps to changing
population characteristics among those who live nearby.
Other studies have investigated whether measured nighttime exposure accounted for the overall increased risk for
childhood leukaemia, but no consistent results have emerged
collectively, and a recent study observed no association
between childhood leukaemia and exposure to electrical
contact currents (the small currents that can flow in the body
when, for example, a metal water tap is touched).

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

7

Overhead power lines and health outcomes
Studies have investigated residential proximity
to high-voltage overhead power lines, a source
of relatively high exposure to power-frequency
EMFs, in relation to a wide range of outcomes
including overall mortality, general well-being, cancer,
neurodegenerative disease, and adverse birth outcomes.
Regarding cancer, nearly all studies were of cancers in
children. The childhood-leukaemia studies were suggestive
of an increased risk with closer proximity, although the latest
study suggests this might be confined to previous decades.
Studies of childhood brain-tumours did not collectively
show increased risk with close proximity, but could not
exclude the possibility of a moderately increased risk at high
exposure levels. A recent UK study of cancer in adults did
not detect associations between risk for several types of
cancer and distance from the power line or magnetic-field
strength. Regarding non-cancer outcomes, a large Swiss
study reported increased mortality from Alzheimer’s disease
in people living within 50 metres of an overhead power line,
based on a small number of deaths in this group. There
are some individual reports of associations of measured
maternal EMF exposure during pregnancy with asthma and
obesity in offspring, findings which require validation by
further research. There is no convincing evidence for an
association of EMF exposure with birth outcomes; a recent
study reported no association of adverse birth outcomes with
residential proximity to transmission lines.
Occupational exposure and health outcomes
Adverse health effects of exposure to powerfrequency EMFs continue to be researched,
in particular in occupational studies, where
exposure levels are sometimes greater than
in the general population, thus providing greater potential
for detection of effects. Many health outcomes have been
addressed including various cancers, cardiovascular
disease, reproductive hormone and melatonin levels, and
neurodegenerative disease such as Alzheimer’s disease
and amyotrophic lateral sclerosis (ALS). A pooled analysis
of fourteen studies of Alzheimer’s disease showed a raised
risk in those occupationally exposed, but with considerable
variation in results between studies, and without a doseresponse relationship. In two later cohort studies, mortality
from Alzheimer’s disease was not increased in UK electricity
generation and transmission workers, but was increased in
Swiss railway employees. A recent study of Swedish twins
suggested that occupational EMF exposure was related
to dementia with earlier onset. Diagnosis of dementias
is particularly problematic and exposure assessment
from job histories needs to be standardised. Reports that
collectively reviewed evidence from all past studies recently
concluded that there might be weak associations between
power-frequency EMFs and Alzheimer’s Disease, Motor
Neurone Disease and ALS. Further occupational studies of
neurodegenerative disease in relation to power-frequency
EMFs are needed.

Data from two recent studies, in Germany and Australia, did
not find evidence that occupational exposure of parents to
power-frequency EMFs increased risk of leukaemia, nonHodgkin’s lymphoma and central-nervous-system tumours
in their children. In contrast, a Canadian study observed
increased risks of brain cancer in offspring after maternal
exposures. Earlier, smaller, studies into childhood cancers
did not find consistent increased risks.
Mobile-phone use and cancer
There is continuing scientific debate and
public concern over possible adverse
health effects of exposure to radio-frequency fields from
mobile phones. There are now a considerable number of
studies on intracranial tumours, glioma, meningioma, and
acoustic neuromas (benign tumours of the auditory nerve
next to the ear); and an increasing number of studies on
other types of cancer. The largest study conducted was
the INTERPHONE case-control study, carried out in 13
countries worldwide and coordinated by IARC to investigate
the risk of intracranial tumours and parotid gland tumours
and the use of mobile-phone handsets. Results on glioma
and meningioma showed an apparently overall decreased
risk of tumours in regular users compared with people
who did not use a phone regularly. As it seems implausible
that mobile-phone use would have a protective effect, this
possibly reflects participation bias (overrepresentation of
mobile-phone users among controls) or other methodological
limitations. There was no association of risk with time since
first use, or cumulative number of calls. Risk of glioma was
increased in users in the top decile (10%) of cumulative
call time, but this category included individuals reporting
implausible daily usage times, and there was no upward
trend in the other nine deciles. Results on acoustic neuroma
were broadly similar to those for meningioma, although in a
secondary analysis where only mobile-phone use more than
5 years prior to diagnosis was considered, an increased risk
was observed in the top decile of cumulative call time. The
study concluded that limitations in the data and lack of clear
evidence of causality, such as dose-response, prevented a
causal interpretation. While the INTERPHONE study and its
preceding reports on results from individual study centres
did not report evidence for substantial, risk increases among
mobile-phone users, if any at all, a research group in North
Sweden continues to report relatively large risk increases
among users, based on case-control studies. The stark
contrast between results from this group and the large body
of other studies argues against a causal association but
suggests that methodological issues are in play.
In 2011, a Working Group from IARC concluded that there
is “limited evidence in humans” for the carcinogenicity
of radio-frequency EMFs, based on positive associations
between glioma and acoustic neuroma and exposure to
radio-frequency EMFs from mobile phones from casecontrol studies. This issue will hopefully be clarified with
results from studies of prospective design which have
methodological advantages over case-control studies.
Recently, a follow-up study of 790,000 women in the UK
found that brain-tumour risks were not raised among those

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

8

who reported mobile phone use for the previous 7 years,
with the possible exception of acoustic-neuroma risk. For the
latter, increased risks were reported which were no longer
present after extending the follow-up time of the study. Also,
a cohort study of 420,000 mobile-phone subscribers in
Denmark followed up for cancer has not shown increases in
risk of brain tumours or acoustic neuroma. Further insights
are provided by studies of trends in brain-tumour rates in
populations. Recent studies in China, the UK, the USA
and Nordic countries have not observed increases which
could be attributed to the uptake of mobile-phone use in
the population, including data from Sweden, one of the first
countries to introduce mobile phones. If future updates of
incidence data in countries with early and high-level uptake
of mobile-phone technology fail to detect rate increases it
would provide strong evidence against a mobile-phone effect.
Studies of other types of cancer in relation to mobile-phone
use have included leukaemia, non-Hodgkin’s lymphoma,
melanoma and other skin cancers, testicular cancer and
salivary gland tumours, and generally have not found
convincing evidence of an association.
Mobile-phone use and other health
outcomes
Recent studies have increasingly focused
on health outcomes other than cancer in mobile-phone
users. The Danish mobile-phone subscriber study also
reported on other outcomes and showed no increase in risk
of hospital contact for Alzheimer’s disease, other dementia,
ALS or other central-nervous-system disease with time since
having the subscription. They also reported no elevation
of risk of multiple sclerosis among subscribers overall, but
found some increases after 10 years since first subscription,
which was restricted to females and based on a very small
number of cases; nevertheless this finding might require
further follow-up. There are some reports of adverse effects
of semen quality and pregnancy duration and an increased
risk of tinnitus in mobile-phone users but these studies were
small and methodologically weak.
Mobile-phone use and health in children
We observed increasing numbers of
studies focussing on health effects of
mobile-phone use in children, including cancer, well-being,
cognitive effects and behavioural problems. There is one
large international study of childhood brain tumours, which
reported no association with mobile-phone use. Recent
studies reported no substantial evidence that children
whose mothers used a mobile phone during pregnancy
were adversely affected in neurodevelopment or other
developmental milestones in infancy. Two studies reported
increased behavioural problems at age 7 years after prenatal
and postnatal exposure; this is potentially due to confounding
by maternal behaviours. A study in Korean school children
observed an association of mobile-phone use with Attention
Deficit Hyperactivity Disorder (ADHD) but it could not be
established whether the mobile phone had caused the ADHD
or whether children with this condition are inclined to use

the phone more. Another study showed that in adolescents,
mobile-phone users had faster and less accurate responses
to higher-level cognitive tasks; such behaviours could have
been learnt through frequent phone use, rather than be
caused by radio-frequency EMFs.
Mobile-phone base station, other radiofrequency transmissions and health
Base stations remain a cause of public
concern, and an increasing number of studies have
specifically reported on this. A large UK study reported no
association between risk of early childhood cancers and
estimates of maternal exposure to base stations during
pregnancy. There are increasing numbers of studies of adult
cancer or mortality around mobile-phone masts but they
are methodologically inadequate. Due to the ubiquitous
nature of masts, the small geographic areas that exposures
relate to, and small numbers of cases within such areas,
this issue is particularly difficult to investigate. A German
cohort study found no association between radio-frequency
exposure and non-specific symptoms or tinnitus, and two
other large cross-sectional studies, one of them in children,
did not find evidence that measured residential exposure to
radiofrequency EMFs was associated with a variety of health
complaints.
Two large case-control studies have investigated exposure
to fields from radio transmitters and childhood-leukaemia
risk. One, in South Korea, observed an increased risk of
childhood leukaemia in proximity to AM radio transmitters,
but not with individuals’ predicted radio-frequency exposure
levels. The other, in Germany, did not find increased risk at
close proximity or with predicted exposure levels from AM
or FM radio transmitters. These two studies weaken findings
from earlier reports on leukaemia clusters around radio and
television broadcast transmitters, which relied on distance
alone as a surrogate measure of exposure.
Occupational exposures and health
Studies of adverse effects of occupational
exposures to radio-frequencies, such as
military personnel exposed to radar, include a large range of
health effects. Overall no strong, consistent associations have
been observed. Some recent studies looked at mortality,
cancer, ECG changes, infertility and pregnancy outcomes.
Some associations were reported, but the studies had
weaknesses in exposure and outcome assessment as well as
other methodological problems. Also, for cancer, it was often
difficult to separate the effect of radio-frequency EMFs from
other known hazardous exposures such as ionising radiation.
In summary, the epidemiological evidence over the past
two years, coupled with earlier studies does not indicate
a need for increased concern about health effects from
electromagnetic fields, and the absence of clear evidence of
health effects, despite on-going research, could be regarded
as reassuring.

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

9

Human Studies
Overall, recent studies with volunteers continue to indicate
that short-term exposure to EMFs at levels usually found in
the environment does not result in consistent or reproducible
biological effects. Nevertheless, some studies have
continued to report a variety of field-related effects but
there is no obvious pattern or trend to these effects. The
continuing absence of replication studies represents a hurdle
in evaluating this literature.
Higher Frequencies
Reflecting public concern, most recent
studies with volunteers have continued to
focus on the effects of radio frequency (RF) fields associated
with mobile phones.
As in previous years, a wide range of endpoints have been
investigated, with no obvious pattern to the results. For
example, contrasting results were observed for the effect on
thyroid hormones. Exposure was found to have significant
effects on a package of effects on saliva and blood flow, yet
another study did not find any genotoxic effect in mucosal
cells. Differing exposure levels had differing effects on
cerebral blood flow, cerebral glucose metabolism, and
on heart rate following intermittent exposure. Changes in
sperm morphology were observed and alterations in semen
hormonal parameters.
Studies have continued to investigate the possibility that
some people show increased responsiveness to RF fields
(sometimes called electrical hypersensitivity, EHS). In
confirmation of earlier results, the majority of these studies
showed no association with symptoms and exposure duration
and type of signals.
Most volunteer studies have focused on changes to brain
activity observed using electroencephalography (EEG).
Most focused on sleep EEG and although changes were
often observed following exposure it is hard to make firm
conclusions due to methodological and other differences
between the experiments. Individual differences in sensitivity
may be important and, while no overall effect might be seen
in the population as whole, it is possible that effects of RF
fields on specific subgroups may exist.
A few reports studied cognitive performance and most
showed no effect, even in older individuals, who have had
longer exposure. However, a short-term exposure in one
study was found to have conflicting results on visual-reaction
time.

Animal Studies
Recent laboratory studies with animals have continued to
use a wide variety of experimental models and exposure
conditions. Many of these studies have reported that
exposure produces biological effects; some adverse, others
beneficial, but none of these has been independently
replicated.

Very few studies have been undertaken using static magnetic
fields, and most have used invertebrate models making it
more difficult to determine the impact of any changes on
human health. In rodents, no consistent effects were seen
on male fertility, although one paper found that prenatal
exposure resulted in subtle but permanent alterations in
hippocampal microstructure which could have lasting effects
on behaviour.
Power Frequencies
There continues to be interest in possible
biological effects of low-frequency magnetic
fields, particularly any potential therapeutic
and neuroprotective effects that these fields
may have in disease models, e.g. Huntingdon’s, seizures,
and traumatic brain injury. Separate, unreplicated, studies
on chemotherapy and ionising radiation treatments suggest
their efficacy may be improved with the addition of magnetic
fields. It has also been reported that these fields may impair
memory function.
Higher Frequencies
The main focus of laboratory research
has been on using mobile-phone
signals. Most studies investigated the effect of foetal
exposure and the effect on the reproductive system.
Behavioural effects were observed in adult mice following
foetal exposures and changes in brain antioxidants, and
alterations of neurotransmitters and neuronal excitability
were dependent on the duration of exposure. Observations
in spermatogenesis or testes ultrastructure were often
contradictory, but changes in the ovary and embryogenesis
were observed in several studies.
Several studies looking at brain metabolism and inflammatory
markers report contradictory changes in terms of
inflammatory markers, but there appears to be no change
in metabolites. A study investigating neuronal metabolites
identified no changes in markers of cell death or oxidative
stress. Changes in specific neuronal cell types have also
been reported but the significance of these is unknown.
A large number of published reports studied learning,
memory, and stress effects, where some impairment were
observed, even following a single exposure, but changes
were not consistently observed in all studies. Most reported
responses were only temporary and adaptive responses were
observed.
Oxidative stress in different tissues has been examined
in many studies, and field-related effects have been
consistently reported, although short-term exposures did not
cause an effect. Some studies showed a protective effect
of the magnetic fields on damage from various substances.
It has been suggested that magnetic fields may have a
beneficial effect on DNA repair with largest effects being
observed in immature rats.

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

10

Changes relating to brain plasticity, oxidative stress, or
apoptosis were observed in a few studies looking at gene
expression, but caution should be used when interpreting
these results in animal models, as it is often not clear how
this translates to humans.

this lack of independent verification is a serious problem for
the interpretation of the data and adds to the uncertainty as
to whether claimed effects are real.

Cellular Studies

Most of the high-frequency studies have
investigated the frequencies used by
mobile telecommunications. However, the evidence for a
direct carcinogenic effect remains weak. For studies that do
report an effect there is a lack of independent confirmation
and for the few studies where replication was undertaken
the claimed effect was not confirmed. The majority of the
studies in this group investigated effects on cell metabolism
and function; some looked for potentially beneficial effects
whereas others looked at the possible harmful effects of
exposure. Nearly all studies find effects but none have been
independently verified. Hence their significance, if any, is
unknown.

Cellular studies have been used extensively to investigate
possible biological effects of EMFs. The studies cover a
broad range of biology from individual proteins to isolated
human cells. These laboratory investigations allow a wide
variety of exposures to be tested relatively quickly in welldefined and controlled conditions. The techniques used can
focus on potential effects in areas of interest, for instance
genetic damage, cell growth, or protein structure; they
can also help ascertain the mechanisms involved in these
interactions. The interpretation of the results from these
studies has limitations in that the experiments use very
simplified biological systems, such as isolated cells grown
in Petri dishes, and hence the observed effects may not
translate into real change in animals or humans. Therefore,
the effects found in these experimental systems, although
very useful indicators, cannot be directly extrapolated to a
health risk.
The static-magnetic-field exposures used in cellular studies
tend to be high in comparison to the geomagnetic field,
typically many milliteslas (the earth’s static field being
approximately 50 microteslas). The main area of research
has been the possible effect on cell growth and metabolism.
Most of the published studies find a stimulatory effect of
static-field exposure but there are more than 20 studies and
each uses a different exposure and cellular system. This
lack of independent replication makes the robustness of the
claimed effects uncertain.
A small number of the cellular studies investigated pulsed
EMFs. These tend to be aimed at medical applications; repair
and pain relief in musculoskeletal disorders, or combined
with other therapies for example to enhance anti-tumour or
bacterial effects. Nearly all studies report effects, but despite
the many publications over several years, the effects, in
general, lack independent verification. Similarly, other studies
of exposure to low-frequency magnetic fields (excluding
power frequencies) nearly all find effects. However, there is
no consistent pattern even using similar biological systems;
some find a stimulation whereas others an inhibition.
Power Frequencies
There is little evidence that power-frequency
EMF exposure causes carcinogenic changes in
cells. Very few new studies have investigated
direct carcinogenic effects; most have looked
for possible metabolic effects, such as cell growth, enzyme
activity or free-radical production. The majority of studies
find effects; however, the results are confusing because
opposing results can be found with apparently similar
exposures and cells. Even fewer independent replications
were undertaken in the last two-year period than previously;

Higher Frequencies

There is considerable doubt about the robustness of all the
claimed cellular effects (both beneficial and harmful) due to
EMF exposure at any frequency using field strengths to which
the public might be exposed. Relatively few independent
replications of claimed effects have been undertaken and
the majority of these replications do not confirm the original
observation. Furthermore, the effects that are reported do
not appear to follow a consistent pattern in terms of exposure
parameters or biological response. A major difficulty in
understanding possible effects, or predicting biological
systems sensitive to EMF, is the lack of a known mechanism
of interaction between physics and biology for these lowenergy signals.

Mechanisms of interaction
Power Frequencies
The absence of a plausible biophysical
mechanism operating at environmental levels
of exposure to power-frequency EMFs remains
a significant component in the weight of the
evidence against health effects. Continued research on one
of the most promising candidates, the effect of magnetic
fields on free radicals (including possible insights gained from
study of magneto-reception in birds and animals) has still
failed to demonstrate that this mechanism could be operating
in the circumstances required to explain the epidemiological
findings.
However, in view of the importance of establishing a
mechanism if there are health effects, BEPAG considers that
this and any other suggested mechanisms should continue
to be studied objectively, but stay rooted firmly in their
relevance to the parameters of public exposure and their
health implications.
An alternative to EMF effects is that some of the
epidemiological findings, specifically those related to highvoltage power lines, might be a result not of magnetic fields
but of some other factor related to such power lines, perhaps

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

11

the characteristics of the areas they pass through. No
specific such mechanism has been identified, but it would
be a way of explaining the absence of a plausible mechanism
for magnetic fields. This line of thinking has been given new
impetus by the recent UK study suggesting that elevated
childhood-leukaemia rates near power lines have decreased
over time and are no longer elevated. BEPAG regards this
as a potentially important finding which presents a real
opportunity to advance understanding.
Higher Frequencies

Conclusions
BEPAG has considered all the factors raised in this report,
along with those in its previous reports which now stretch
back over twenty years. It has concluded that the balance
of scientific evidence to date does not indicate that harmful
effects occur in humans, or animals, due to low-level
exposure to EMFs. Our examination of the peer-reviewed
literature published in the last two years has not justified a
change in this overall conclusion, which was published in our
previous report in May 2012.

The accepted scientific consensus
including that of BEPAG is that at higher
frequencies the only established effect of EMF on biological
tissue is that of heating. When EMF exposures are within
current guideline levels the human physiology can adequately
dissipate the resultant energy deposition. At a subcellular
level, a hypothesis that localized regions of high-power
deposition may occur is the subject of on-going investigation
for both continuous and pulsed fields, however at this stage,
the hypothesis remains unproven.
There is further speculation that low-frequency pulsing of
modulated high-frequency signals may give rise to nonthermal interactions and that there might be some cellular
structures capable of demodulating these fields. However
this hypothesis also remains unproven and a detailed study
of possible demodulation effects was negative.
With short-term exposures being well investigated and
understood, epidemiological studies are thus the focus of
many research groups in an attempt to identify additional
mechanisms of interaction. These studies often focus on
children and young adults to capture a cohort of potentially
long-term-exposed users and thus increase the chances of
identifying exposure attributed health effects, which may
shed light on the mechanism of interaction.
The magnetic properties of most biological materials are
close to those of free space; however, reports of the presence
of magnetite in animal brain tissue may provide a mechanism
for direct interaction of magnetic fields with the central
nervous system. Mechanisms have been proposed whereby
biogenic magnetite in the brain could act as a transducer
of EMFs. The work in this field is still very limited, the
plausibility of the mechanisms is being debated, and the role
of magnetite in the human brain is the subject of on-going
research. Effects involving magnetite, if significant, may also
occur at power frequencies.

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

12

Appendix
Search Criteria
BEPAG concentrates on peer-reviewed literature retrieved by
broad-category, computerised, monthly searches of relevant
major databases, currently: INSPEC, MEDLINE and BIOSIS.
INSPEC is a database maintained by the IET. Coverage
is centred on four main subject areas: physics; electrical
engineering; electronics and communications; computers,
computing and information technology.
MEDLINE is the database maintained by the US National
Library of Medicine (NLM). It provides access to articles
published in more than 3,900 biomedical journals published
around the world.
BIOSIS is an American ‘not-for-profit organisation’ that
publishes biological abstracts and zoological records. It
provides access to 6,000 periodicals covering biological and
biomedical sciences.
Records from monthly research of these databases for
peer-reviewed scientific EMF and health studies were sent
to all members of BEPAG for assessment against a set of
weighted criteria. The results of these assessments were
fed back to the Secretary for inclusion within the contiguous
indexed database. Identified trends in the assessed scientific
knowledge for each discipline were used to inform, through
consensus, the biennial IET position statement.

10. ‘The Possible Harmful Biological Effects of Low-level
Electromagnetic Fields of Frequencies up to 300 GHz’
(IET Position Statement – May 2010)
11. ‘The Possible Harmful Biological Effects of Low-level
Electromagnetic Fields of Frequencies up to 300 GHz’
(IET Position Statement – May 2012)
BEPAG Membership
To inform its members, and the wider public, about any
possible harmful health effects of exposure to low-level
EMFs, the IET recruited, from within its membership, and
where not possible from the UK’s scientific community, a
voluntary world-class expert group [BEPAG] knowledgeable
in the issues and the underlying science. The multidisciplinary group formulates and explains the IET’s scientific
evidence based position. To conform to requirements to
participate in an IET committee the expert-group members
bring to its work their professional knowledge, experience
and expertise. They are specifically required to not be
influenced by their employer’s, or other third parties,
interests.
BEPAG members
Professor Anthony T. Barker (Chairman)
Dr Kerry A Broom
Dr Leslie A. Coulton
Sami Gabriel
Dr Minouk J. Schoemaker
Dr John Swanson
Graham Barber (Secretary)

Previous BEPAG Reports
1. ‘ The Possible Biological Effects of Low-frequency
Electromagnetic Fields’ (Public Affairs Board Report No
10 - July 1991)
2. ‘The Possible Biological Effects of Low-frequency
Electromagnetic Fields’ (Supplement to PAB Report No
10 - June 1994)
3. ‘Possible Harmful Biological Effects of Low-level,
Low-frequency, Electromagnetic Fields’ (IEE Position
Statement - November 1996)
4. ‘Possible Harmful Biological Effects of Low-level,
Low-frequency, Electromagnetic fields’ (IEE Position
Statement – May 1998)
5. ‘The Possible Harmful Biological Effects of Low-level
Electromagnetic Fields of Frequencies up to 300 GHz’
(IEE Position Statement – May 2000)
6. ‘The Possible Harmful Biological Effects of Low-level
Electromagnetic Fields of Frequencies up to 300 GHz’
(IEE Position Statement – May 2002)
7. ‘The Possible Harmful Biological Effects of Low-level
Electromagnetic Fields of Frequencies up to 300 GHz’
(IEE Position Statement – May 2004)
8. ‘The Possible Harmful Biological Effects of Low-level
Electromagnetic Fields of Frequencies up to 300 GHz’
(IET Position Statement – May 2006)
9. ‘The Possible Harmful Biological Effects of Low-level
Electromagnetic Fields of Frequencies up to 300 GHz’
(IET Position Statement – May 2008)

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

13

Biographies
Graham Barber BSc(Hons) CEng MIET
BEPAG Secretary and Principal Policy Advisor, the IET
To the role of BEPAG Secretary Graham brings experience
from a prior career in broadcast and telecommunications
engineering at both a technical and senior management level.
This is enhanced through his IET work on providing technical
knowledge to benefit the formation of evidence based public
policy.
Professor Tony Barker BEng(Hons) PhD CEng CSci FIET
FIPEM SRCS
Consultant Clinical Scientist, Sheffield Teaching Hospitals
NHS Foundation Trust
Tony works in the NHS Department of Medical Physics
and Clinical Engineering at the Royal Hallamshire Hospital
in Sheffield, where he is the departmental research lead.
One of his main roles is to research the biological effects of
electromagnetic fields, both for therapeutic and diagnostic
purposes, and also their possible deleterious effects. His
research includes the stimulation of the human brain
with very large magnetic-field pulses; using electrical
stimulation to aid muscle function; and replication studies
of electromagnetic-field effects in both cellular and human
studies, carried out in laboratory, volunteer and clinical
research environments.
Dr Kerry Broom BSc DPhil(Oxon) CBiol FSB
Principal Radiation Protection Scientist, Public Health
England
Kerry’s current responsibilities include experimental research
studies on the biological effects of non-ionising radiation
and secretariat support to the Committee on Medical
Aspects of Radiation in the Environment (COMARE).
Previously, Kerry has been responsible for the day-to-day
scientific management of the Radiation Protection Research
Programme for the Department of Health. Her research
focuses on the effect of radiofrequency fields on the brain,
and she is particularly interested in the potential behavioural
impacts of EMF exposure in animal models.

Professor Sami Gabriel BEng(Hons) MSc FIET MIEEE
Chief Engineer, Vodafone Group Services Limited
Sami has studied engineering and information technology
before becoming a researcher in bio-physics and organic
chemistry. He worked extensively on the characterisation
of the dielectric properties of biological tissues and the
development of synthetic alternatives for use in safety
and compliance evaluation. Sami continues his academic
involvement as a guest professor of dielectrics. He now works
as an EMF compliance expert advising on the use, testing
and certification of wireless devices and base stations with
national and international exposure limits within Vodafone
Group. Internationally he has worked on compliance
standards for over 15 years with IEEE, ICES, CENELEC and
IEC.
Dr Minouk Schoemaker BSc MSc MSc PhD
Staff Scientist, The Institute of Cancer Research, London
Minouk trained in Environmental Health Sciences in the
Netherlands and in Radiation Biology, Medical Statistics
and Epidemiology in the United Kingdom. Her research
focus is on risk factors for cancer, including endogenous
and environmental factors and lifestyle behaviours. She
was intensively involved in a large case-control study of
brain tumours in relation to mobile-phone use in the United
Kingdom which contributed to the Interphone Study and
several other international collaborations.
Dr John Swanson MA DPhil CPhys CEng CRadP FInstP FIET
FSRP
Scientific Advisor, National Grid
John has worked in the electricity industry on the issue of
power-frequency EMFs for over twenty years. His training
was as a physicist and his career started entirely in research,
initially into understanding exposures and into mechanisms.
He now continues with research, increasingly applying the
understanding gained of exposures in epidemiology, but also
has roles in policy and communication.

Dr Les Coulton BSc PhD
Senior Research Scientist, University of Sheffield
Les has been involved in bone and bone cell research at
Sheffield for over 30 years. Throughout that time has had a
research interest in possible biological effects of exposure
to low-level electromagnetic fields, in particular effects on
isolated cells at both radio and power frequencies. He has
been a member of the Advisory Group on Non-Ionising
Radiation (AGNIR) for Public Health England (formally HPA)
since 2001.

Are there harmful Biological Effects of Low-Level Electromagnetic Fields at Frequencies up to 300 GHz?
A Position Statement provided by The Institution of Engineering and Technology
www.theiet.org/factfiles

14

Position
Statement

The Institution of Engineering & Technology
Michael Faraday House
Six Hills Way
Stevenage
SG1 2AY
01438 765690 - Policy Department
email: [email protected]
http://www.theiet.org/policy
http://www.theiet.org/factfiles
The Institution of Engineering and Technology is registered as a Charity in England & Wales (no 211014) and Scotland (no SC038698).

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