Mthr report 2012

Mobile Telecommunications and
Health Research Programme

Report 2012

MTHR Programme Management Committee

Mobile Telecommunications and
Health Research Programme

Report 2012

Chairman: Professor David Coggon OBE

© Crown copyright 2013
Produced by Public Health England for the
Mobile Telecommunications and Health Research Programme Management Committee
ISBN 978-0-85951-754-6

Contents

Executive Summary

1

1 Introduction

3

2

Epidemiological Studies of Cancer

5

3

Effects of Exposure to TETRA Signals

8

4

Importance of Signal Modulation

11

5

Assessing Exposures

15

6

Experimental Exposures

19

7

Future Arrangements

22

8 References

23

Glossary and Abbreviations

24

Appendices
A

MTHR Phone Exposure System Specification

26

B

MTHR Base Station Exposure System Specification

34

C

Publications Arising from the MTHR Programme

39

D

Membership of the MTHR Programme Management Committee

43

iii

Executive Summary

In this report we discuss the results of research funded
by the Mobile Telecommunications and Health Research
(MTHR) Programme and published since 2007. The
MTHR Programme was established in 2001 as part of
the government’s response to the recommendations
of the Independent Expert Group on Mobile Phones
(Stewart Committee), and the research supported
has focused on addressing the uncertainties identified
by that committee. The Programme has had total
funding of approximately £13.6 million provided
jointly by government and industry. In order to ensure
that none of the funding bodies could influence the
outcome of the research, projects were selected and
monitored by an independent Programme Management
Committee (PMC).
Over a period of 11 years, the MTHR Programme
has supported 31 individual research projects that
between them have resulted in almost 60 papers in
peer-reviewed scientific journals. All but one of the
research projects is now complete, and the Department
of Health has decided that this is an opportune time
to bring research on mobile phones and health into
its mainstream research portfolio. Accordingly the
Programme has been wound up and future research will
be commissioned and managed on behalf of the current
funders through the Department of Health Policy
Research Programme.
It is now seven years since the publication of our last
report, which summarised the results published in
the first six years of the MTHR Programme, and it is
appropriate to report on the remaining completed
projects. This report effectively marks the end of
the Programme, but rather than summarise all the
outcomes here, it is our intention that this report
should be read in conjunction with our 2007 report so
that together they form an overview of the Programme
in its entirety. Our focus in this report is to present
an overview of the results that were not in the public
domain when our 2007 report was published. We also
discuss the projects we funded to ensure that project

teams working in the life sciences had expert help with
radio engineering and dosimetry.

Epidemiological studies of cancer
In this report we discuss the work we supported
to investigate whether maternal exposure to base
station emissions during pregnancy could affect the
risk of developing cancer in early childhood. A second
project investigated the risk of leukaemia in relation
to mobile phone use. Neither of the studies identified
any association between exposure and an increased
risk of developing cancer. These findings appear to be
consistent with the results from other recent studies
examining similar endpoints. We have also set up the
UK component of an international cohort study of
mobile phone users (COSMOS), which has the potential
to help resolve many of the remaining uncertainties
relating to the health risks of mobile phone use. This
is necessarily a long-term study that is expected to
continue for many years. Its management will now be
taken forward by the DH Policy Research Programme
and we look forward to seeing the results of this study
published in due course.

Effects of exposure to TETRA signals
There has been considerable public concern about
the possible adverse effects of exposure to signals
produced by the TETRA radio system used by the
emergency services. We supported three well-designed
studies to investigate whether exposure to TETRA
signals from hand-held radios or base stations could
affect a range of responses in volunteers. Importantly
the experiments were all carried out ‘double blind’ so
that neither the experimenter nor the subject knew
whether the exposure was real or sham. None of the
studies provided any evidence that TETRA signals
produce specific adverse effects in those exposed
to them.

1

Mobile Telecommunications and Health Research Programme Report 2012

Importance of signal modulation

Experimental exposures

A key question in this area is whether the modulations
applied to radio signals to enable them to carry voice
and data communications can elicit specific effects that
are different from those of the carrier frequency alone.
We supported three projects to examine this issue in
different ways, including one that tested whether a
wide range of cells and tissues could demodulate the
signal. None of the projects found any evidence that
modulated signals produced different effects from
the carrier frequency. When taken together with the
findings from the provocation studies we supported,
which also compared modulated signals with carrier
frequencies, we believe that these results constitute
a substantial body of evidence that modulation
does not play a significant role in the interaction of
radiofrequency fields with biological systems. This
conclusion has extremely important implications and
should facilitate the pooling of data from different
studies and allow conclusions to be drawn with
greater confidence.

In order to standardise exposures in provocation
studies, we commissioned phone and base station
exposure systems. We explain in this report our thinking
behind the selection of these systems and the exposure
levels used in the provocation studies we supported.
Technical descriptions of the systems and details
of their calibration are provided in appendices to
the report.

Assessing exposures
We supported work that demonstrated conclusively
that wired hands-free kits can be used to reduce
exposures from a mobile phone, provided the phone is
positioned away from the user’s body. We also funded
the development of assessment methodologies that
could be used to investigate exposures from new types
of mobile telecommunications devices and provided
funding towards the development of new UK standards
and standard assessment protocols to be used for
assessments of exposures. In addition, we supported
work to assess the emission of low frequency magnetic
fields from mobile phones. These field strengths are
much lower than those that are known to have effects
in excitable tissues.

2

Future arrangements
As indicated above, in the future research on mobile
phones and health will be taken forward as part of
the DH Policy Research Programme. Under these new
arrangements the independent Advisory Group on
Non‑ionising Radiation will assume responsibility for
drawing research needs to the attention of the UK
health departments.
In the meantime we have shared our views on research
priorities with the UK health departments. We see no
need for further research in any of the areas addressed
by the research that is summarised in this report.
However, we have identified several other areas of
uncertainty regarding mobile telecommunications and
health, in which the UK has well-established research
expertise and could make a significant contribution.

1
Introduction

The Mobile Telecommunications and Health Research
(MTHR) Programme was set up in 2001 as part of the
government response to the recommendations of the
Independent Expert Group on Mobile Phones (Stewart
Committee), and was formally wound up in 2012.
During the 11 years of its existence the Programme
used funds provided jointly by government and industry
to support 31 research projects that resulted in almost
60 publications in peer-reviewed journals, along with
many conference papers. Each completed project also
generated a final report for publication on the MTHR
website (www.mthr.org.uk).
In September 2007 we published a report on the
outcomes from the first six years of the Programme
(MTHR PMC, 2007). This explained the contribution
made by the Programme in relevant areas of research.
However, we were only able to discuss research results
that had been published, and therefore our report
was effectively restricted to just over half of the
31 projects supported by the Programme.
It is now six years since the publication of our 2007
report and, given that the Programme has been
wound up, it is appropriate to report on the remaining
completed projects.

Background
The Independent Expert Group on Mobile Phones
(Stewart Committee) was set up at the request of the
Minister for Public Health to examine the possible
adverse health effects from mobile phones and
base stations. Its report (IEGMP 2000) included a
,
recommendation for a major UK research programme
operating under the aegis of a demonstrably
independent panel. The programme was to investigate
the health aspects of mobile phones and related
technologies, and it was intended that it would
complement work sponsored by the European Union
and other national programmes of work. The Stewart
Committee also recommended that the research should

be financed jointly by the mobile phone companies and
the public sector.
These recommendations were supported by government
and industry and led to the establishment of the
MTHR Programme. Over the course of the Programme,
core funding amounted to approximately £12 million,
provided in approximately equal share by government
and industry. Additional funding of around £1.6 million
was provided the then Department of Trade and
Industry, the Home Office, the Department of Health
and the private sector, and used to support additional
research work that fell outside the priorities set for the
core funding.
In order to ensure that none of the funding
organisations, whether industry or government,
could influence the outcome of the Programme, an
independent Programme Management Committee (PMC)
was set up to decide on research priorities, select
projects and manage the research. Sir William Stewart
originally chaired the PMC, which included some
members of IEGMP along with additional experts,
,
who together provided a broad range of expertise.
Some change in membership occurred over the
years and this is summarised in an appendix to the
report. Professor Lawrie Challis became chairman on
Sir William’s retirement in November 2002, and was
succeeded as chairman by Professor David Coggon in
January 2008.
In determining research priorities, the PMC built on the
recommendations outlined in the Stewart Report. The
Programme focused largely on establishing whether or
not biological or adverse health effects occur in people
as a result of exposure to radiofrequency (RF) fields
below guideline levels. It was noted in the Stewart
Report that research on the possible health effects of
mobile telecommunications signals had not been well
funded. This situation had been detrimental to the
overall quality of research activity in this area, with
some notable exceptions, and inevitably therefore
some of the research results that received attention

3


by the media were of questionable reliability and
validity. It was the aim from the outset to provide
sufficient resources to allow high quality research to
be undertaken and encourage high calibre scientists to
become involved with the Programme. In particular, we
encouraged collaborative working between specialists
in different disciplines, such as radio engineering and
cell biology.

a condition of their funding. The 2007 report also
summarises the results of those projects that had been
published at the time of its preparation. The focus of
the 2012 report is to present an overview of results
that were not in the public domain at the time that
the 2007 report was prepared. Full, final reports on all
completed projects have been published on the MTHR
website (www.mthr.org.uk), which will be archived to
ensure the contents remain available.

2007 and 2012 reports

This report also discusses the supporting projects that
were put in place to ensure that research teams with
expertise in the life sciences were able to produce
consistent and quantifiable exposures to realistic mobile
telecommunications signals. Appendices to the report
provide technical descriptions of the exposure systems
commissioned specifically for use in the provocation
studies we supported. Other appendices provide a full
list of almost 60 peer-reviewed publications produced
by the various project groups, and the biographical
details of all those who were members of the PMC
during the 11 years of the MTHR Programme.

It is our intention that the 2007 and 2012 reports,
when taken together, will form an overview of
the MTHR Programme in its entirety. Many of the
fundamental elements of the Programme have
already been described in detail in the MTHR Report
2007. For example, the 2007 report gives details of
the approach taken by the PMC to the selection and
monitoring of projects, and explains the elements of
good practice in the design and execution of projects
that research groups were required to follow as

4

2
Epidemiological Studies of Cancer

Background
In May 2000 the Stewart Committee noted that there
had been few epidemiological studies of cancer in
relation to mobile phone use (IEGMP 2000). The
,
two studies that were reviewed in the Stewart Report
were found to have major limitations. In the absence
of any studies specifically relating to emissions from
mobile phone base stations, the Stewart Committee
examined the small number of studies that had
investigated residence close to broadcast transmitters.
However, it considered that these were also subject to
major limitations, particularly in relation to exposure
assessment and their ‘ecological’ study design.
The Stewart Report consequently identified a pressing
need for a range of epidemiological studies designed
to overcome many of the limitations of the existing
work. In particular, it identified a need for case–control
studies to investigate whether leukaemia and cancers
of the brain, acoustic nerve and salivary gland were
associated with mobile phone use. (For an explanation
of case-control and other epidemiological study designs
see Box 1, page 10, of the MTHR Report 2007.) The
emphasis was placed on studies of mobile phones,
reflecting our understanding of how people are exposed
to mobile phone signals; exposures from mobile phones
are substantially higher than those from base stations.
A secondary reason for prioritising studies on mobile
phones was the considerable difficulty associated with
reliably assessing and classifying exposures from base
stations (see the box).
Exposures from mobile phones are not uniform, with
the head the most highly exposed part of the body
when the phone is used in traditional speech mode.
It follows from this that any increase in risk is likely
to be highest for cancers of the brain and nervous
system. We supported UK studies to investigate these
cancers as part of an international research project
called Interphone, and the results of these studies are
discussed in Section 2 of the MTHR Report 2007.

Classifying Exposure from Base Stations
People are exposed to RF fields from many
environmental sources, including broadcast TV
and radio, cordless phone systems, professional
radio communications systems, pagers and mobile
phone systems.
Even if consideration is restricted to mobile phone
signals, exposures may arise from an individual’s
use of a phone, the use of phones by other people
close by, and base stations. Of these, the base
station exposure is by far the weakest, although it is
normally more or less continuous.
With the exception of broadcast TV and radio
transmitters, all the sources have variable output
and, in addition, an individual’s personal exposure
will vary as they go about their daily routine,
travelling towards or away from sources, going
indoors or outdoors, or moving so that buildings or
vegetation are between the source and the person.
All of this makes it very difficult to characterise
exposure from mobile phone base stations while
distinguishing it from other sources of exposure that
may be similar in frequency.
We supported work to characterise a personal
exposure meter in an effort to resolve some of
these problems, and this was discussed in the
MTHR Report 2007. Nevertheless, we remain
cautious about the classification of exposures in
base station studies.
We are more confident about the classification
of exposure from mobile phone use, although we
recognise that even this has limitations.

5


In this section we focus on those epidemiological
studies that we were unable to discuss in the previous
MTHR report because the results were not available at
that time. These three studies address the remaining
priorities of the Stewart Committee: studies on
children; a case-control study of the risk of leukaemia;
and a large UK cohort study of mobile phone users.

leukaemia and non-Hodgkin’s lymphoma; and all
cancers combined. While exposure classification was
better than for many earlier studies, it did suffer
many of the limitations commonly associated with
base station studies (see the box) and, in particular, it
was not possible to take account of RF exposure from
sources other than the base station or to estimate
exposure within the home.

New evidence

The results of this study need to be viewed in the
context of other studies that have been carried out
elsewhere since the publication of the Stewart Report.
There have been no studies examining childhood cancer
in relation to base station emissions, but a number of
studies have investigated whether childhood cancer is
associated with exposure from broadcast transmitters.
One of these (Michelozzi et al, 2002) suffers many of
the limitations identified for other ‘ecological’ studies
in the Stewart Report. The remaining studies (Ha et al,
2007, 2008; Merzenich et al, 2008) are better in terms
of both study design and exposure assessment, and also
provide no material evidence for an increased risk of
childhood leukaemia or brain cancer from residential
RF exposure. All of these studies were limited in their
ability to detect small increases in risk.

The Stewart Report noted that if there were
unrecognised health risks, children might be more
vulnerable for a number of reasons. Having given
consideration to the issue, we decided that we
could not ethically support provocation studies on
children, but that we could support epidemiological
studies on children who had already been exposed.
We therefore decided to fund a case-control study by
Professor Paul Elliott and colleagues at Imperial College
London to investigate if exposure during pregnancy
affected the risk of developing cancer in early
childhood. By assuming that the mother had resided
at the birth address during the pregnancy, the study
team was able to assess exposure during pregnancy
rather than at diagnosis, thus overcoming one of the
previously identified limitations of residential studies.
The issue of latency (the time between a causative
event and the cancer being diagnosed − see Box 2,
page 11, of the MTHR Report 2007) often complicates
the interpretation of epidemiological studies in this
area, but is minimised when the study is restricted to
young children, as latency is necessarily much shorter.
The project team identified almost 1400 cases of
cancer in children aged up to four years old from
across the UK. The team then selected four controls for
each case on the basis of sex and date of birth. Three
separate measures of exposure were assessed for each
of the mothers: distance from the nearest macrocell
base station; total output of base stations within 700 m
of the address; and an estimate of power density at
the birth address. Power density was calculated from
technical parameters of the base station as well as
distance. This model was more sophisticated than the
simple estimates based on distance used for earlier
studies and was validated by field measurements. There
was no correlation between any of the three measures
of exposure and the incidence of any of the categories
of cancer examined: brain and central nervous system;

6

We noted above that exposures from the use of mobile
phones are highest in the head and that we had
therefore supported studies to investigate possible
associations with cancer of the brain and nervous
system. The skull and jaw contain approximately 13%
of the body’s active bone marrow and so it is relevant
to investigate also if use of a mobile phone could affect
the risk of leukaemia. As the latency for leukaemia is
typically much shorter than that for solid cancers such
as brain tumours, effects on the incidence of leukaemia
might be detectable sooner after first use of a mobile
phone. This could be important given the relatively
short period for which mobile phones have been in
widespread use.
We therefore decided to support Professor
Anthony Swerdlow (Institute of Cancer Research) to
carry out a large case-control study to investigate
whether the risk of acute and non-lymphocytic
leukaemia is associated with mobile phone use. Just
over 800 people diagnosed with leukaemia between
2003 and 2009 were identified for inclusion in the study.
They were matched to around 600 controls selected on
the basis of age and residence criteria from non‑blood

2 Epidemiological Studies of Cancer

relatives of those with leukaemia. Participants in
the study were interviewed by a research nurse who
collected information on their mobile phone use,
together with other possible risk factors such as
smoking history, occupational history, medical history
and family history of medical conditions.
The study found no association between regular use of
a mobile phone and the risk of leukaemia. There was
also no evidence of a trend of increasing risk with the
time since a mobile phone was first used, total years
of use, cumulative number of calls or cumulative hours
of use. Although there was a suggestion of an increased
risk of acute myeloid leukaemia with long-term phone
use (more than 15 years), this was not statistically
significant and appears unlikely to be real, given the
normally short latency for this cancer. There was no
evidence of a higher risk related to the use of analogue
or digital phones.
The results from this study are consistent with those
from a cohort study of mobile phone subscribers in
Denmark (Schüz et al, 2006); the Danish study found
no increase in the risk of leukaemia with long-term use
and no evidence of a trend with length of use. A much
smaller case-control study from Thailand (Kaufman
et al, 2009) had various limitations and provides little
in the way of additional evidence.

Future directions
Taken together, the studies discussed in this section
and those in Section 2 of the MTHR Report 2007 do
not suggest that exposure to mobile phone signals is
associated with an increased risk of cancer. Given the
short time that mobile phone use has been widespread,
none of these studies has been able properly to
investigate risk in relation to long-term phone use.
In addition, we recognise that all these studies have

other limitations. In particular, the case-control
design inevitably requires retrospective assessment of
exposure, which is problematic, especially if reliant
upon the participant’s memory, and so a possible source
of bias. Many of these problems can be circumvented
by a cohort study design as exposure can then be
assessed during the progress of the study. The major
disadvantages of cohort studies are the cost, the time
required to obtain meaningful results, and the risk of
losing touch with participants as the study progresses.
Given the advantages of the cohort design, the
Stewart Committee was convinced of the value of
putting in place a cohort study of mobile phone
users. However, because of the logistic challenges
that it would entail, the Committee also suggested
that a pilot study should be undertaken first. We
endorsed the view of the Stewart Committee and
supported Professors Paul Elliott (Imperial College) and
Anders Ahlbom (Karolinska Institute, Sweden) to carry
out the pilot study. This was discussed in Section 2 of
the MTHR Report 2007.
The pilot study demonstrated the feasibility of a cohort
study, and we therefore funded Paul Elliott to set up
the UK component of a large multinational cohort study
(COSMOS) based on the methodology of the pilot study.
The study has recruited over 100,000 participants in
the UK and, together with similar studies in Sweden,
Denmark, Finland and the Netherlands, there are
around 160,000 participants in all. For each participant,
information is being collected on health, mobile phone
use and other possible risk factors. A key element
of the exposure assessment will be information on
mobile phone use supplied for each participant by the
companies that provide mobile phone services (mobile
operators). With the closure of the MTHR Programme,
oversight of this long-term study in the UK will be taken
forward by the Department of Health Policy Research
Programme on behalf of all the funders.

7

3
Effects of Exposure to TETRA Signals

Background
The pulsed nature of TETRA handset transmissions has
been a source of significant concern for the public
and certain occupational groups − notably the police
− and, to a lesser extent, those working in the other
emergency services. The Stewart Committee had
noted reports that exposure to radiofrequency fields
could increase the release of calcium ions from brain
tissue, an effect that appeared to be specifically
associated with amplitude modulation at frequencies
around 16 Hz. On this basis the Stewart Committee
recommended avoiding amplitude modulation around
16 Hz in future signal coding as a precautionary
measure. This suggestion gave rise to understandable
concerns in TETRA users, given the similarity between
this amplitude modulation frequency and the pulse
repetition frequency of 17.6 Hz generated by TETRA
handsets (see the box).
Recognising these concerns, we decided to fund
research to examine aspects of the effects of exposure
to TETRA and other pulsed fields. Some of this work
related to fundamental interactions of RF fields with
biological tissues, including research to investigate if
pulsed RF fields can alter cellular calcium metabolism.
Another project examined the potential for biological
systems to detect low frequency modulations of
RF fields. A third project explored the effects of a
variety of modulation regimes, including TETRA, on
exposed nervous tissue and examined responses at
the molecular, cellular and behavioural levels. As
these studies all have application beyond TETRA,
they are discussed separately (see Section 4). In
addition, the MTHR Programme supported work by
Professor Tony Barker (Royal Hallamshire Hospital,
Sheffield) to assess possible effects on the brain
centres controlling the cardiovascular system in healthy
volunteers. This work is discussed in more detail in the
MTHR Report 2007.

8

Characteristics of TETRA Signals
It is a characteristic feature of the TETRA
communications system that the signals from base
stations and handsets are fundamentally different.
In order to increase spectrum efficiency, TETRA
employs time division multiple access (TDMA), with
each frequency channel divided into four timeslots.
1

2

3

Timeslot numbers
4
1
2
3

4

1

Time

1 frame = 56.7 ms

1 timeslot = 14.2 ms

Each communicating handset transmits into just
one of the four available timeslots, with the result
that the handset transmits for approximately onequarter of the time. This has two significant effects
on exposures from handsets:
a average exposures are approximately onequarter of peak exposures,
b the exposure is pulsed, with a pulse repetition
frequency of 17.6 Hz.
The transmissions from base stations are also
divided between the four available timeslots.
However, in contrast to handsets, the base
station may well be communicating in more than
one timeslot. Indeed, even where there is no
communications traffic in a timeslot, the base
station still transmits. Hence the output from base
stations is quite different to that from handsets,
because although instantaneous power necessarily
varies with time, owing to the effect of encoding
information, the average power over the duration of
a timeslot or longer is essentially continuous and not
pulsed. Further technical details of TETRA and other
communications systems are given in Appendix C of
the MTHR Report 2007.

3 Effects of Exposure to TETRA Signals

New evidence
This section discusses the results of three studies that
examined the effects of exposure to TETRA signals on
the responses of volunteers.
We supported two studies that were designed to
investigate whether exposure to TETRA signals
characteristic of handsets could elicit detectable
responses in volunteers. Both studies used a randomised
double-blind design and conformed to the basic
principles for provocation studies set out in the
MTHR Report 2007. They both used the TETRA variant
of the MTHR mobile phone exposure system described
in more detail in Appendix A.
In the first of these studies, Stuart Butler
(Burden Neurological Institute, Bristol) and
Professor Alan Preece (University of Bristol) carried out
a thorough assessment of the effects of exposure to
a TETRA signal or the unmodulated carrier frequency
on brain function. Cognitive and electrophysiological
responses were measured in healthy volunteers who
were observing visual stimuli, listening to auditory
tones or receiving sensory stimuli to the skin. The brain
activity associated with these sensations was recorded
from the scalp using standard electroencephalographic
(EEG) techniques. Special care had to be taken to
rule out direct effects of RF exposure on the sensitive
recording equipment used. Analysis focused on
whether the brain activity evoked by these three
types of external stimulus was affected by exposure.
Additional experiments investigated effects of the same
exposures on the background EEG pattern, on reaction
times and on brain activity evoked by stimuli under
different cognitive load conditions. The study found no
statistically significant changes in any of the responses
assessed during exposure to either type of signal.
A further experiment investigated whether TETRA
exposures could directly evoke brain responses
rather than simply modify the response to recognised
environmental stimuli. As brain responses to stimuli
occur very rapidly, the standard exposure system
described in Appendix A was modified to produce short
bursts of exposure that could be synchronised with
recordings of brain activity. There was no evidence
that exposure to RF pulses directly evoked detectable
electrical activity in the brain.

In addition to investigating direct effects on brain
function, we considered it a high priority to explore
whether the particular modulation characteristics
of TETRA emissions could affect the symptoms of
electrical hypersensitivity. Professor Simon Wessely’s
team at King’s College London carried out a large
randomised, double-blind study using essentially the
same design that the team had previously employed
to investigate the effects of mobile phone exposure
(described in Section 4 of the MTHR Report 2007).
As in the earlier study, there were two groups of
volunteers, one consisting of people who reported
experiencing symptoms when using TETRA radios and
one comprising people who did not. Both groups were
almost exclusively police personnel. All volunteers who
completed the study participated in three 50-minute
‘exposure’ sessions: sham; carrier frequency; and
TETRA signal. All the participants were asked to selfassess the severity of a range of symptoms prior to,
at intervals during, and following exposure. The study
found no evidence for adverse effects of exposure to
TETRA signals, although there was some evidence that
exposure to the carrier frequency alone decreased skin
symptoms (itching, tingling, stinging and numbness) in
sensitive participants.
A few other studies have examined the effects of
exposure to TETRA handset signals. Consistent with the
results of the two MTHR-funded studies, a randomised
double-blind study of emergency services workers found
no evidence for effects on cognitive performance or
subjective symptoms (Riddervold et al, 2010). Outside
the MTHR Programme, the Home Office has provided
support to Adrian Burgess (Imperial College London and
Aston University) to carry out a further study on police
officers. It will be interesting to see how the results of
this study compare with the MTHR-funded work.
We were aware that the specific concerns about the
possible effects of the pulsed signals emitted from
TETRA handsets had resulted in widespread public
concern about exposure to emissions from TETRA base
stations. Much of this concern appeared to be based
on a misunderstanding, as the output from TETRA base
stations is quite different to that from handsets and
is not pulsed. Nevertheless, given the level of public
concern and numerous anecdotal reports of symptoms
typical of electrical hypersensitivity, we felt there was
a need for a provocation study.

9


Professor Elaine Fox (University of Essex) investigated
self-reported symptoms, physiological responses and
performance in cognitive tests using a study design
that was similar to that of her earlier study on mobile
phone base stations (described in Section 4 of the
MTHR Report 2007). Two groups of volunteers were
recruited: one consisted of individuals who reported
sensitivity to electromagnetic fields and the other
was made up of people who said that they were not
sensitive to electromagnetic fields. The subjects were
‘exposed’ to sham or TETRA signals in a screened
room that greatly reduced the intensity of other radio
signals present in the general environment. Both groups
participated in three testing sessions.
The first session included an open provocation
consisting of 15-minute ‘exposures’ during which both
subjects and researchers were aware of whether the
condition was sham or TETRA. This was followed by a
short double-blind test consisting of four five-minute
exposures (two sham and two TETRA) separated by twominute gaps. The volunteers were asked to say whether
they thought the base station was ‘on’ or ‘off’. They
were asked to make similar judgements at the end of
the main double-blind provocations in the second and
third sessions (see below). When taken collectively,
neither group was able to identify the exposure
condition better than would be expected by chance,
although two sensitive and three control subjects
correctly judged exposures in all six trials. With the
large number of subjects (180 in total) in the study, a
few would be expected to show a high success rate by
chance alone.

10

The second and third sessions involved randomised
double-blind exposures with one exposure condition
per session. Blood volume pulse, heart rate and
skin conductance were measured throughout each
50-minute session. In addition, the participants
completed health and well-being questionnaires every
five minutes during the first 40 minutes, followed by
cognitive testing and a judgement of whether the field
had been on or off. The study found no evidence that
exposure to a TETRA base station signal affected any
of the measures of health or well-being in either the
sensitive or the control groups, although the sensitive
group generally reported a greater number and severity
of symptoms than the non-sensitive group, regardless
of the exposure condition. Exposure to a TETRA signal
did not elicit any differences in cognitive performance
or physiological responses in either group of subjects
(Wallace et al, 2012).

Future directions
None of the studies supported by the MTHR Programme
provided any evidence that TETRA signals produce
specific adverse effects in those exposed to them.
There have been few other systematic studies of
exposure to TETRA signals and the results published to
date appear to be consistent with the findings from the
MTHR Programme.
Should positive findings emerge from currently
unpublished work these may provide a basis for further
investigation. However, in the absence of significant
new data we feel there is no need for further research
into the specific effects of TETRA signals.

4
Importance of Signal Modulation

Background
A key issue in interpreting the scientific evidence for
possible adverse health effects from exposure to mobile
telecommunications signals is whether different types
of signal can elicit specific effects.
All radio communications systems start with a carrier
wave at a specific frequency or frequencies and this
is then modified or ‘modulated’ to enable information
to be encoded in it. The transmitter (phone or base
station) modulates the carrier to encode information,
while the receiver (again phone or base station)
demodulates it to extract the information, which may
be audio, video or data. In addition to the encoding
of information, the transmitted signal may be further
modified to improve the efficiency of spectrum usage.
For example, both GSM mobile phones and TETRA
radios employ a technique called time division multiple
access (TDMA). When a user speaks into a GSM phone,
the information is compressed into little packets, each
lasting 580 millionths of a second. The phone transmits
these packets at intervals of around 4.6 milliseconds.
As each phone is transmitting for only one-eighth of
the time, eight phones can simultaneously share the
same frequency channel. However, in consequence,
the carrier signal from the phone is pulsed. Technical
constraints imposed by international communications
standards often result in further modification of signals.
More information about the technical characteristics
of individual communications technologies is given in
Appendix C of the MTHR Report 2007.
As a result of modulation, the signals produced by
different technologies can be very different. For
example, the signals produced by a GSM 1800 MHz
mobile phone will be very different from those
produced by a 3G phone, even though both operate
with carrier frequencies close to 2 GHz. A fundamental
question that follows from this is whether biological
effects are dependent on specific modulations or
solely on carrier frequency. To help resolve this
question we made it a basic principle in the design

of MTHR provocation studies that subjects should be
challenged with sham, carrier wave and modulated
exposures (see Section 1 of the MTHR Report 2007).
However, we recognised that these studies would not
necessarily provide definitive evidence on their own,
particularly if no effects of RF exposure were observed.
We therefore decided that additional studies should
be supported to investigate specifically the effects
of modulation, and determine whether a mechanism
existed by which biological tissues would be able to
demodulate signals.

New evidence
All three studies discussed in this section explored the
effects of modulated signals on nervous tissue as this is
known to be sensitive to low frequencies such as those
used for modulation.
Zenon Sienkiewicz (at the Centre for Radiation,
Chemical and Environmental Hazards of the then
Health Protection Agency) co-ordinated a multicentre
project team to investigate the possible effects on
brain tissues of carrier frequencies and modulations
representing three common communications systems:
TETRA, GSM and UMTS. Other members of the
multidisciplinary project team included Professor
James Uney (Bristol University Research Centre for
Neuroendocrinology) and John Tattersall (Defence
Science and Technology Laboratory). By applying the
latest gene chip and related technologies alongside
standard neurophysiological recording techniques and
well-established assessments of learned behaviour,
it was possible to investigate the effects of exposure
at different levels of biological organisation. When
used in isolation, each of these approaches has its
own strengths and weaknesses that influence the
interpretation of results. The great advantage of this
study was to combine the three different approaches
in an integrated way so that each consolidated the
conclusions from the others.

11


Overall the study found no evidence of consistent
changes in learned behaviour, the electrical activity
of memory cells or gene expression following brain
exposure to any of the carrier frequencies or modulated
signals. A small number of isolated changes were
observed, but false positive results are always likely
with such a large and complex study. The isolated
changes showed no consistent pattern and were not
supported by similar changes in related endpoints,
suggesting that they simply reflected experimental
variability. The results from this project, when
viewed collectively, provide powerful evidence that
modulations characteristic of common communications
systems do not engender significant biological effects
on brain tissue.
Short-term changes in cytosolic calcium ion
concentration are well established as important
signals controlling a wide range of cellular activities
in many different cell types. They were investigated
in a second MTHR-funded study. Intracellular calcium
concentrations are very carefully regulated and shortterm increases in cytosolic calcium associated with
cellular signalling may be generated by the release of
calcium ions from stores within the cell, or by influx
from outside the cell through the activation of specific
calcium channels within the cell membrane.
The Stewart Report highlighted the possibility that
amplitude-modulated RF signals might induce calcium
release from brain tissue, but noted that the evidence
was contradictory and the implications unclear. In part,
the difficulties in interpretation relate to the advances
in scientific understanding that have occurred since
the original calcium efflux studies were conducted.
While calcium is well established as an important
cellular signal, the signalling involves increases in
cytosolic calcium, not release of calcium from cells to
the extracellular fluid. Moreover, a major limitation of
the early studies was the use of tissue that had almost
certainly died by the time the effect was observed.
Despite the limitations of this earlier work, it has
engendered considerable concern, particularly in
relation to TETRA signals, and we therefore considered
it important to support a study that would examine
meaningful measures of calcium signalling using modern
techniques. The Babraham Institute in Cambridge
specialises in studying cell signalling processes, so
Martin Bootman and his colleagues from that institute

12

were considered to be ideally placed to carry out
this work.
Calcium responses were studied in two types of
cultured nerve cells and a cell line derived from human
blood vessels, which is a well-established model for
calcium signalling. Cultured cells were ‘exposed’ to
sham, 900 MHz carrier frequency or GSM-modulated
signals, and calcium ion concentrations within the
cells were studied using state-of-the-art real-time
imaging of fluorescence from a calcium indicator dye.
The automated high-throughput imaging technology
permitted large numbers of samples to be analysed.
Images of cells were captured at 30-second intervals
for 90 minutes; ‘exposure’ occurred during the middle
30 minutes of this period. No effects of exposure on
resting or spontaneous calcium concentration were
found for either the carrier frequency or the modulated
signal in any of the three cell types tested.
A second type of experiment tested the effects of
exposure during provocation of cultured human blood
vessel cells. In these experiments cells were treated
with chemicals known to stimulate the release of
calcium from cellular stores, or to deplete intracellular
calcium ultimately leading to its re-entry from outside
the cells. None of the exposure conditions produced
any significant differences in the responses of the cells
to the chemical treatments.
The results from this study are broadly consistent
with those from other recent studies. For example,
a study at the Defence Science and Technology
Laboratories found no effect on intracellular calcium
ion concentration measured with fluorescent indicators
in cultured brain cells or cardiac muscle cells during
exposure to a TETRA-modulated signal (Green et al,
2005). Similarly, a study at the University of Bologna,
Italy, found no effect of exposure to a 900 MHz carrier
frequency or a GSM-modulated signal on the movement
of ions through voltage-gated calcium channels across
the membranes of cultured brain cells (Plantano et al,
2007). In contrast, a study at the University of Illinois,
USA, found evidence that spontaneous spikes in
cytosolic calcium ion concentration were increased by
exposure of cultured nerve cells to carrier frequencies
between 700 and 1100 MHz (Rao et al, 2008). However,
the effect did not depend on the intensity of exposure,
and modulation was not investigated.

4 Importance of Signal Modulation

As noted above, carrier frequencies can be modulated
in various ways. These include amplitude modulation
and frequency modulation (AM and FM), commonly
used in broadcast radio. Many digital communications
systems make use of phase modulation and many
introduce an element of pulse modulation, as in GSM
and TETRA. While these modulation regimes are all
different in detail, in general they all have the effect
of introducing new components into the frequency
spectrum of the transmitted signal. However, in
practice these new frequency components are generally
very similar to that of the carrier wave and so it seems
rather unlikely that they could interact in a novel way
with biological tissue or elicit appreciably different
effects. Hence we consider that the most likely means
by which a modulated signal would produce a novel
effect would be if biological tissues were able somehow
to demodulate the signal and extract the low frequency
component. This would be important because cells,
particularly nerve cells, can be sensitive to low
frequency fields of sufficient intensity.

Maryland and then shipped to Simon Bouffler’s team
at the then Health Protection Agency to carry out the
actual assessment of biological materials. Dosimetric
support was provided by Professor Peter Excell of the
University of Bradford.
As expected, positioning a Schottky diode within
the cavity resulted in the generation of a strong
second harmonic response. Similar experiments with
seven different cultured cell lines (adherent and nonadherent) and thin slices or sections of eight different
tissues did not produce detectable second harmonic
responses; all the cells and tissues were tested to show
they were still alive at the end of each exposure.

In electronic circuits, such as those that form the
basis of radio receivers, demodulation is achieved
through the use of a detector. There are many designs
of detector, depending on the sophistication of the
device and the type of signal to be demodulated, but
in general there is an element of non-linear response,
usually achieved by incorporating semiconductor
devices such as diodes into the circuits. Similar,
non‑linear processes are likely to be required in
order for biological tissues to demodulate signals.
It is a characteristic of these non-linear processes
that they will produce a new frequency component,
called a second harmonic, which has a frequency
of exactly double the carrier frequency. This led
Professor Quirino Balzano of the University of Maryland,
USA, to propose a new test of the potential for
biological tissues to demodulate a signal.
The experimental design recognised that biological
systems might be rather poor at demodulation so that
the resulting second harmonic signal could be very
weak. The experiment was therefore based around
a doubly resonant cavity (see the figure) that was
designed to trap the energy of any second harmonic
component generated. This was coupled with very
sensitive detection equipment so that the experiment
would be capable of detecting extremely weak second
harmonic components. The cavity was constructed in

Loading the doubly resonant cavity in preparation for an
exposure (photograph courtesy of Public Health England)

13


Future directions
The three MTHR projects discussed in this section
represent different state-of-the-art approaches to
investigating the possibility that modulated signals
might elicit different effects from unmodulated
carrier frequencies. However, none of the experiments
provided any evidence that this was the case. Taken
individually, each project provides clear evidence in
relation to specific endpoints. All three studies included
an examination of excitable nerve cells as these are
considered to be particularly sensitive to externally
applied low frequency electric fields. Of the three
projects, we consider that the demodulation project is
particularly compelling as it addressed the fundamental
process of demodulation with a sensitivity unrivalled by
other studies.
While the three projects each provide evidence in
relation to specific endpoints, we believe there is
merit in considering the results of all three projects
collectively to bear on the fundamental question of
whether modulated signals interact differently from

14

carrier frequencies. In doing this it is also important
to view these results in the context of the findings
from the provocation studies discussed both in this
report and in the MTHR Report 2007. We made it a
requirement of provocation studies supported by the
MTHR Programme that they should compare the effects
of modulated signals with those of the corresponding
carrier frequencies. Taken together, we believe that
the results from these eight studies constitute a
substantial body of evidence that modulation does not
play a significant role in the interaction of RF fields
with biological systems. This conclusion has extremely
important implications as it provides a reasonably high
degree of confidence that the results obtained with a
modulated signal characteristic of one communications
system can be extrapolated to exposures from other
systems operating at similar frequencies. This should
facilitate the pooling of data from different studies and
allow conclusions to be drawn with greater confidence.
On the basis of the results discussed in this section we
do not consider that further investigation of the effects
of modulation should be a priority.

5
Assessing Exposures

Background
As noted in previous sections, the single largest source
of exposure to radiofrequency radiation for most
people is their own phone. As the radio signal emitted
by a phone spreads out in all directions, exposure of a
user can be reduced by increasing the distance of the
phone from the body. The Stewart Committee (IEGMP
,
2000) noted in its report that in principle it should be
possible to achieve such a reduction through the use
of an appropriately designed hands-free kit, provided
the phone is moved away from the body and not simply
shifted from the head to the torso.
However, the Stewart Committee also noted that as
hands-free kits had not been designed for this purpose
there was a possibility that for wired devices the
cable might itself radiate or carry radio signals to the
ear rather than reducing exposure. A Which? report
published in April 2000 (Consumers Association, 2000)
contained results indicating that the use of a wired
hands-free kit could actually increase exposure of
the user, although other results obtained around the
same time appeared to contradict the Which? findings,
demonstrating a large reduction in exposure. The
Stewart Committee concluded that as neither report
contained an adequate description of how the tests
had been conducted, it could not form a clear view on
the matter.
We believe that while there is continuing uncertainty
over the possible effects of mobile phone signals, users
should have clear information on the options available
to them to reduce their exposures should they wish to.
We therefore commissioned new work to investigate this
issue properly and provide a definitive answer.
Just as the use of a hands-free kit could alter the
pattern of exposure, many of the new ways of using
mobile phones that have become popular over the
last decade might also result in different patterns and
levels of exposure relative to the traditional approach
of holding the phone next to the ear. Many of these

changes have been dependent on the technological
development of phones that we could not have reliably
predicted. Nevertheless, from the outset we recognised
that the evolution of communications technology would
result in new exposure scenarios and we therefore
commissioned work to develop assessment techniques
appropriate for these novel situations.
The confusion that existed in May 2000 over whether
hands-free kits increased or decreased exposures of
users illustrates the importance of having standardised
approaches for assessing exposures. When two teams
making measurements of the same situation obtain
very different results, it suggests that important
aspects of the measurement procedure have not
been properly considered by one or both teams. We
therefore supported two projects that aimed to develop
and make available to research teams resources to
standardise aspects of exposure assessment.
It is well established that some cells, particularly
nerve cells, can be sensitive to low frequency fields
of sufficient intensity. We explained in Section 4 how
we supported work to investigate whether biological
material can demodulate mobile phone signals to
generate these low frequency components. There is,
however, another potential source of low frequency
components and that is the electronic circuit in
the mobile phone. Most work on exposures from
mobile phones has concentrated on the RF emissions,
so we decided that additional work was required
to measure the low frequency fields generated by
mobile phones.

New evidence
One of the studies described in this section examined
exposures during the use of hands-free kits. Three
others were concerned with the development of
standard exposure assessment methods. The final study
examined low frequency fields from mobile phones.

15


The procedures used to assess exposure arising from
the use of a mobile phone placed against the ear are
complex, but well established. Factors such as the
exact position of the phone are extremely important
as small changes in distances can have large effects
on the magnitude of exposure. In practice, different
people hold their phones differently and even individual
users will move the phone about − so, to overcome this
variability, internationally agreed assessment protocols
use a standard position for the phone. This allows
comparisons to be made between different makes and
model of phone and gives a representative measure of
exposure, but obviously does not necessarily indicate
the actual exposure received by any individual user.
The situation for the assessment of exposures while
using a hands-free kit is potentially more complicated
owing to the wide variety of possible positions in
which the phone and hands-free kit cable could be
placed. Consequently any assessment would need to
establish which realistic arrangement would give the
maximum exposure. Stuart Porter and his colleagues at
the University of York approached the problem by first
assessing the layout of the hands-free cable relative to
the phone that induced the highest power in the cable.
They then established the orientation of the hands-free
cable relative to the user that resulted in the highest
deposition of energy in the head.
The team made measurements of the RF current
induced in the hands-free cable and of the energy
absorbed inside an artificial head (phantom) filled
with tissue-equivalent material (see the figure).
Measurements were made with a range of hands-free
kits and phones, and currents induced in the cable in
the presence of a realistic phantom were verified using
a person in place of the phantom.
The work established that exposures were strongly
dependent on the layout of the cable relative to the
phone, and whether the cable ran across other parts
of the body, which reduced exposures to the head. The
proximity of the cable to the head was only moderately
important in affecting exposure, although it was more
important for phones operating at higher frequencies.
The specific type of hands-free kit had a relatively
minor influence, although it could affect the position of
peak absorption. The frequency band also had a minor
effect on the exposure.

16

Head phantom and robotic arm used to make specific
energy absorption rate (SAR) measurements

Importantly, all of the combinations tested resulted in a
sizeable reduction in head exposure compared to using
a phone alone. The size of the reduction relative to the
small differences observed between different handsfree kits gives confidence that this will be the case for
all wired hands-free kits. It was also possible to show
that a ferrite bead placed around the hands-free cable
could further reduce exposures.
Stuart Porter and his colleagues undertook a second
study to investigate exposures resulting from the use
of new mobile telecommunications technologies such
as more sophisticated handsets, hands-free devices,
laptops and wearable devices. At the time the study
was commissioned, most mobile telecommunications
still involved the relatively simple situation of a user
holding a GSM mobile phone in the traditional position
against the ear. However, we recognised that the rapid
evolution of mobile telecommunications technologies
would generate a need to develop new assessment
techniques that would try to anticipate these advances.
It was expected that new technologies would make use
of a wider range of frequencies, signal characteristics
and antenna types, and would result in exposure of
other parts of the body.

5 Assessing Exposures

The project team started by undertaking a survey
of developing technologies and from this identified
five frequency bands corresponding to private mobile
radio, mobile telecommunications systems and WiFi/
Bluetooth. It was considered that the systems might
make use of a range of different antenna types and
could give rise to exposures in five broad areas of the
body: the shoulder, chest, waist (side), waist (back) and
groin. Given the combinations of antennas, frequencies
and wear positions, the team considered 45 different
exposure scenarios. Assessments were carried out using
both physical phantoms and computer modelling. For
the physical measurements, the team constructed
generic communications devices that incorporated
onboard monitoring functions to allow the behaviour
of the device to be determined in the presence of
the body.
There were no clear trends in the results with regard
to wear position, frequency band or antenna type.
However, the study did demonstrate that truncation
of computer models could be used to reduce the
time needed to run simulations, while for physical
measurements a flat phantom generally provided a
reasonable estimate of worst-case exposure.
It is often important to be able to compare
measurement results obtained by different researchers
working in different locations. Such comparisons
can only be meaningful where it is known that the
instruments being used produce similar results
when exposed to the same field. This depends on
the calibration of the instruments and is something
generally taken for granted when using, for example,
a ruler or thermometer. This is because manufacturers
put a lot of effort into ensuring not only that all their
products have the same calibration, but also that they
have the same calibration as other manufacturers’
products. This is achieved by ensuring that all
calibrations are traceable to a standard. In the UK
the National Physical Laboratory (NPL) maintains a
wide range of primary standards, including those for
specific energy absorption rate (SAR), the quantity
used to assess RF exposure. We provided funds to help
Ben Loader and colleagues at NPL establish a new
national standard for SAR at the frequencies used by
TETRA systems. The team was also able to extend the
existing NPL calibration facilities at GSM frequencies
to improve characterisation of probe responses.
These developments directly benefited research

projects within the MTHR Programme that involved
SAR measurements. In addition, they have provided a
national resource for both research and industry.
In addition to having good calibration of instruments,
it is also important to ensure that the correct
measurement procedures are followed to ensure that
exposures are properly assessed. This area is relatively
specialised and expertise resides in a small number of
individuals. We therefore commissioned Phil Chadwick
of MCL to co-ordinate leading experts from around the
world to write a measurement manual known as the
EMF Dosimetry Handbook. A large number of chapters
were produced, each authored by an expert in that
aspect of measurement.
While a great deal of effort has been put into the
measurement of RF exposures from mobile phones,
relatively little work has been undertaken to quantify
exposures to low frequency magnetic fields. These
magnetic fields are produced by the flow of electric
current from the battery and through the electronic
circuits of the phone. For devices operating with a
pulse-modulated RF output (see Section 4), the current
flow from the battery to the transmitter circuit is also
pulsed and produces a magnetic field that is pulsed
at low frequency. As noted in Section 4, it is well
established that cells are sensitive to low frequency
fields of sufficient intensity, and so we considered
it important to establish the intensity of the low
frequency magnetic fields produced by mobile phones.
Michael Hall and his colleagues at NPL used a sensitive
magnetic field probe to measure the fields produced
by two GSM mobile phones and two TETRA emergency
services radios. In all cases the highest fields were
measured at the rear of the handset, suggesting that
they were produced by current flow in the battery
or nearby circuits. In all four cases, low frequency
magnetic flux densities were a few microtesla in the
direction of the head, but higher in other directions.
These field strengths are much lower than those known
to have effects on excitable tissues. In addition to the
low frequency fields, all the handsets produced static
magnetic fields that were somewhat more intense.
Movement of the phone relative to the head during
use could effectively convert this to a low frequency
exposure that would be higher than that resulting from
pulse modulation of the transmitter output.

17


Future directions
The work we supported resolved once and for all the
question of whether hands-free kits could be used to
reduce exposures. The magnitude of the reduction
was sufficiently large relative to differences between
individual hands-free kits that we are confident that
a general principle has been established. It was also
shown that a ferrite bead, correctly positioned around
a hands-free cable, would further reduce exposure. The
research team responsible for this work kindly made the
data available to the appropriate standards committee
and we see no need for further work on this issue.
Most of the other work described in this section was
to establish resources that could be used to improve

18

assessments in the future. Further development work
will doubtless be required in time, but we feel this
would best be taken forward by standards committees
and organisations such as NPL. We feel that in the
future, the mobile communications industry should be
best placed to assess exposures from novel technologies
as the industry is aware of what is being developed and
can carry out assessments long before products come
to market.
The work on low frequency magnetic fields
demonstrated that these fields are relatively small,
particularly when compared with fields from other
appliances held near the head, such as electric razors
and hairdryers. We do not see further work in this area
as a priority.

6
Experimental Exposures

As recommended by the Stewart Committee (IEGMP
,
2000), we made provocation studies on volunteers a
major component of the MTHR Programme. However,
we were aware that one of the difficulties in the
interpretation of the results from previous studies had
been the wide range of exposures and exposure systems
used. We felt very strongly that all the projects funded
by the Programme should, so far as possible, use the
same exposure systems and the same exposures. Hence
although each individual research team had proposed
to use its own exposure system, we resolved that all
exposure systems would be commissioned, maintained
and calibrated centrally.
We recognised that this placed a significant
responsibility on us to ensure that the exposure
systems we provided were fit for purpose. We therefore
established a subgroup of the Programme Management
Committee to agree the specification. The subgroup
took advice from external expert advisers and also
discussed the designs with the research teams that
would be using them.

Mobile phone exposure systems
We decided that the system chosen would have to
satisfy a number of key criteria:
a

dosimetry should be thoroughly characterised,

b

exposures should mimic mobile phone use,

c

the system must be simple to use,

d

the time frame for delivery should be reasonable
as delays would hold up a number of projects,

e

the system must incorporate blinding.

After considering a number of options, we concluded
that a system enclosed within the casing of a mobile
phone handset offered the best solution. This would
most closely mimic the distribution of exposures found
for a real phone and would have the added advantage

that subjects would perceive the test situation as
relevant to effects of mobile phones, a concept known
as ‘face validity’.
Any exposure system would need to be mounted with
respect to the subject’s head as separation distance
and positioning could have a large effect on exposures.
We concluded that the use of a headband would be
more acceptable to subjects than alternatives such as a
helmet arrangement.
We decided that for mobile phone exposures we
would concentrate on 900 MHz GSM signals as these
had been used in the majority of the previous studies.
There was also a need to provide TETRA exposures,
but differences, particularly in transmission frequency,
meant that both signals could not be produced by the
same units. We therefore commissioned a TETRA variant
of the exposure system, and in due course this was also
selected for use by the Home Office TETRA Programme.
We had already decided that all the mobile phone
provocation studies should involve exposure to
modulated, continuous and sham signals. The sham
signal was to be produced by diverting the signal from
the antenna into a load within the phone. This was
important to minimise any possibility that either a
researcher or subject could recognise whether the
phone was in sham or expose modes from subtle
cues such as heating or noise. Thermal imaging of
the first exposure systems by Professor Tony Barker
(Royal Hallamshire Hospital) revealed differences in
temperature distributions in the different operational
modes and the units were subsequently modified to
address this problem.
The question of which signal would be diverted to
the internal load during sham operation was also an
important consideration. Modulation of the output
results in generation of a low frequency magnetic field
from the battery (see Section 5). If the modulated field
were diverted to the internal load then the unit would
not emit an RF signal, but would generate the low

19


frequency magnetic field. This could have complicated
the interpretation of results, and we therefore decided
that during the sham condition it would be a continuous
signal that was diverted to the internal load.
The exposure systems were to be used in double-blind
studies, and it was therefore essential that the output
mode could be selected without revealing which mode
had been chosen to either the experimenter or the
volunteer. After consideration of the blinding controls
originally proposed, we asked for the design to be
modified to make the blinding more sophisticated. We
decided that the blinding codes would be released to
the research teams at the outset, but should not be
revealed to those actually carrying out the testing.
As the studies involved volunteers, we did not want
exposures to exceed international guidelines for
public exposure (2 W/kg for localised specific energy
absorption rate (SAR) in the head) and, given a 30%
uncertainty in measurement values, we specified that
the exposure systems should produce a spatial peak
SAR of 1.4 W/kg. After some discussion we opted to
set this target in terms of rms time-averaged SAR; we
recognised that this would result in a higher peak SAR
during operation in the modulated mode compared
with the continuous mode. We also commissioned
NPL to characterise the low frequency magnetic
fields generated.
Another issue we discussed was whether the exposure
systems should be capable of simulating operation
in discontinuous transmission (DTX) mode. Phones
operating with DTX only transmit when the user is
speaking (this is done to prolong battery life). We
did not think there was a need to use DTX in MTHR
provocation studies because other research had
reported effects in the absence of DTX. Moreover, it
would be necessary to select a pattern of transmission
that represented DTX operation during a ‘typical’ phone
conversation. Nevertheless, we decided to have a DTX
capability built into the phones so that this could be
used in future studies, if needed.

Base station exposure system
Exposure from a base station is rather different to that
from a mobile phone. Exposures from phones are highly
localised, typically to the head, and much higher than
those from base stations. Base station exposures are
generally more uniform across the body due to the
distance from the base station.
The much lower exposure means that environmental
signals are a potential confounding factor. We therefore
recognised very early on that if we were going to
support base station provocation studies, they would
have to be carried out in a screened room. This would
effectively eliminate exposure to environmental signals
from both phones and base stations. In addition, it
would prevent signals generated by the exposure
system from escaping into the environment and so
simplify the licensing arrangements. We concluded
that the screening would need to achieve 40−60 dB of
attenuation. In the end we were able to acquire a suite
of screened rooms that had previously been used at NPL
but were no longer required. Some modification of the
rooms was necessary in order to adapt them for use in
provocation studies.
We recognised that the final design of the exposure
facility would be a compromise between the
requirements for ideal exposures and the comfort of
the subjects. The subjects needed space to be able to
move and not feel claustrophobic. In addition, it was
important that they did not feel intimidated by the
antenna producing the exposure or by the presence
of absorber material necessary for the function of
the room. It was also considered helpful for there to
be a screened window that would allow contact with
the world outside the exposure chamber. As tests
would take some time to complete, it was considered
essential that volunteers should be able to sit down. It
was also necessary to achieve a satisfactory separation
between the subjects and the radiating antenna so that
exposures would be uniform and far field, like those
encountered from a real base station.
After some consideration of the matter, we decided
that GSM signals would have to include both a
broadcast control channel (emitted at constant power)
and a traffic channel (emitted at variable power with
partial occupancy of the timeslots normally assigned
to different users, as described in Appendix C of the

20

6 Experimental Exposures

MTHR Report 2007). We also agreed that the GSM signal
should be a mix of 900 MHz and 1800 MHz GSM signals
so as to simulate real exposures. The UMTS signal was
modulated to simulate traffic on the channel using an
industry-standard model.
We also spent some time considering an appropriate
exposure level and decided that the exposure should
be towards the upper end of the range of exposures
from a networked base station as measured in publicly
accessible areas. We concluded that each of the

exposure conditions should generate a power density of
10 mW/m2 at the position of the subject. For the mixed
signals, this power density would be the total power
density from all components.
Having commissioned the mobile phone base station
exposure system, we had this system modified to
produce TETRA signals when we commissioned a TETRA
base station study. The general design considerations
were therefore the same, and the TETRA system also
produced a power density of 10 mW/m2 at the position
of the subject.

21

7
Future Arrangements

In 2012 the Department of Health, as the government
department with lead responsibility for the MTHR
Programme, reviewed the arrangements for supporting
research into the possible health effects of mobile
phone technology in the context of the changing
research landscape. It was recognised that a substantial
number of important studies had been commissioned,
overseen and disseminated through the Programme.
Moreover, the research supported by the Programme
had helped to allay anxieties about the health impact
of mobile phones and addressed many key questions.
DH acknowledged that the MTHR Programme
Management Committee had played a highly important
and successful role in developing the evidence base
in a complex area during a period of considerable
uncertainty and public concern. Nevertheless,
there was concern that the role of the PMC as
selector, reviewer and manager of research was no
longer consistent with current research governance
arrangements for the management of externally
funded research.

health departments and other research funders. In the
meantime we have shared our views on future research
priorities with the UK health departments and these
have been used to inform an invitation to tender issued
by the PRP We have reproduced our advice below.
.

Advice on future research priorities
In arriving at these recommendations, we assessed
research already funded in the UK and elsewhere in
the context of the research priorities identified in the
WHO Research Agenda for Radiofrequency Fields 2010
(WHO, 2010). In our view, there are important areas in
which the UK has well-established research expertise
and could make a significant contribution.
We consider the following to be priority areas:

The PRP has now taken on the management of the only
ongoing project, the COSMOS study (see Section 2).
This is currently funded until March 2014, when a final
report for this phase of the study will be produced.
Under the new arrangements, the Advisory Group on
Non-ionising Radiation will assume responsibility for
drawing research needs to the attention of the UK

22

studies of long-term behavioural/neurological
outcomes in children and/or adolescents in
relation to mobile phone usage,

b
Following consultation with ministers and other
sponsors of the MTHR Programme, DH decided that
it wished to bring research on mobile phones and
health into its mainstream research portfolio. It was
therefore decided that in future the research would
be commissioned and managed on behalf of all the
current funders by the DH Policy Research Programme
(PRP). The PRP is a national funding programme of
independent research, commissioned using high quality
processes, and with the use of independent experts on
the commissioning group and as peer-reviewers.

a

provocation studies on children,

c

provocation studies to identify neurobiological
mechanisms underlying possible effects of mobile
phone signals on brain function, including sleep
and/or resting EEG,

d

studies in suitable animal models of the effects of
early-life and prenatal exposure on development
and behaviour,

e

studies in suitable animal models of effects on
ageing and neurodegenerative diseases.

8
References

Consumers Association (2000). The ring of truth. Which?
April 2000.

MTHR PMC (2007). Mobile Telecommunications and Health
Research Programme Report 2007. Chilton, NRPB.

Green AC, Scott IR, Gwyther RJ, Peyman A, Chadwick P
,
Chen X, Alfadhl Y and Tattersall JE (2005). An investigation
of the effects of TETRA RF fields on intracellular calcium in
neurones and cardiac myocytes. Int J Radiat Biol, 81(12),
869−85.

Platano D, Mesirca P Paffi A, Pellegrino M, Liberti M,
,
Apollonio F, Bersani F and Aicardi G (2007). Acute
exposure to low-level CW and GSM-modulated 900 MHz
radiofrequency does not affect Ba2+ currents through
voltage-gated calcium channels in rat cortical neurons.
Bioelectromagnetics, 28(8), 599−607.

Ha M, Im H, Lee M, Kim HJ, Kim BC, Gimm YM and Pack JK
(2007). Radio-frequency radiation exposure from AM radio
transmitters and childhood leukemia and brain cancer. Am
J Epidemiol, 166(3), 270−79.
Ha M, Im H, Kim BC, Gimm YM and Pack JK (2008). Re:
‘Radio-frequency radiation exposure from AM radio
transmitters and childhood leukemia and brain cancer.’
Reply. Am J Epidemiol, 167(7), 884−5.
IEGMP (2000). Mobile Phones and Health. Report of an
Independent Expert Group on Mobile Phones (Chairman:
Sir William Stewart). Chilton, NRPB.
Kaufman DW, Anderson TE and Issaragrisil S (2009). Risk
factors for leukemia in Thailand. Ann Hematol, 88(11),
1079−88.
Merzenich H, Schmiedel S, Bennack S, Brüggemeyer H,
Philipp J, Blettner M and Schüz J (2008). Childhood
leukemia in relation to radio frequency electromagnetic
fields in the vicinity of TV and radio broadcast
transmitters. Am J Epidemiol, 168(10), 1169−78.
Michelozzi P Capon A, Kirchmayer U, Forastiere F,
,
Biggeri A, Barca A and Perucci CA (2002). Adult and
childhood leukemia near a high-power radio station in
Rome, Italy. Am J Epidemiol, 155(12),1096−103.

Rao VS, Titushkin IA, Moros EG, Pickard WF, Thatte HS and
Cho MR (2008). Nonthermal effects of radiofrequencyfield exposure on calcium dynamics in stem cell-derived
neuronal cells: elucidation of calcium pathways. Radiat
Res, 169(3), 319−29.
Riddervold IS, Kjaergaard SK, Pedersen GF, Andersen NT,
Franek O, Pedersen AD, Sigsgaard T, Zachariae R, Mølhave L
and Andersen JB (2010). No effect of TETRA hand portable
transmission signals on human cognitive function and
symptoms. Bioelectromagnetics, 31(5), 380−90.
Schüz J, Jacobsen R, Olsen JH, Boice JD Jr, McLaughlin JK
and Johansen C (2006). Cellular telephone use and cancer
risk: update of a nationwide Danish cohort. J Natl Cancer
Inst, 98(23), 1707−13.
Wallace D, Eltiti S, Ridgewell A, Garner K, Russo R,
Sepulveda F, Walker S, Quinlan T, Dudley S, Maung S,
Deebie R and Fox E (2012). Cognitive and physiological
responses in humans exposed to a TETRA base station
signal in relation to perceived electromagnetic
hypersensitivity. Bioelectromagnetics, 33(1), 23−39.
WHO (2010). WHO Research Agenda for Radiofrequency
Fields 2010. Geneva, World Health Organization.

23


Glossary
Amplitude modulation encoding of information by
varying the magnitude of the carrier waveform.
Bias any process at any stage of inference that tends to
produce results or conclusions that differ systematically
from the truth.
Broadcast control channel frequency channel that
permanently transmits identification and control
information from a base station.
Calcium efflux process of rapid release of soluble
calcium from cells or tissues.
Carrier frequency frequency of the radio wave on
to which information is encoded through a modulation
process.
Carrier waveform waveform on to which information is
encoded by modulation.
Case-control study an investigation of the extent to
which a group of people with a specific disease (cases) and
people who do not have the disease (controls) differ with
respect to exposure to putative risk factors.
Cognitive function higher processes of the brain
involving the processing of information.
Cognitive testing general name for tests measuring
speed and accuracy of mental performance. These can
include reaction times and tests of perception, attention
and memory.
Cohort a group of people identified in an epidemiological
study and followed up to see who develops disease.
Cohort study an investigation involving the identification
of a group of people (the cohort) about whom certain
exposure information is collected and ascertainment
of the occurrence of disease(s) at later times. For each
person, information on prior exposure can be related to
subsequent disease experience.
Confidence interval an interval calculated from data
when making inferences about an unknown parameter.
In hypothetical repetitions of the study, the interval
will include the parameter in question on a specified
percentage of occasions (eg 95% for a 95% confidence
interval).

24

Discontinuous transmission facility that allows
transmission only in the presence of speech; used to
prolong battery life.
Dosimetry measurement of the power or energy
deposited in an object.
Double-blind design a stringent way of conducting an
experiment in an attempt to eliminate subjective bias
on the part of either the experimental subjects or the
researcher. In a double-blind study neither the subject nor
the researcher knows the exposure conditions until all the
data collection and processing has been completed.
Electroencephalogram (EEG) technique for measuring
the electrical activity of the human brain by recording
electrodes placed on the scalp.
Electrophysiology (electrophysiological) study of the
electrical properties of biological cells and tissues that
result from changes in membrane potential.
Epidemiology (epidemiological) study of the
distribution and determinants of health and illness in
populations.
Face validity extent to which a test appears (when
taken at face value) to measure what it is intended to
measure.
Far field region of an electromagnetic field where there
is a simple relationship between the electric and magnetic
field components of a propagating wave.
Fluorescence process whereby absorption of a photon
of light results in emission of another photon at a longer
wavelength; used as the basis of many extremely sensitive
biochemical assays.
Frequency modulation encoding of information by
varying the frequency of the carrier waveform.
Latency term used to describe the delay between
exposure to an agent or event that causes an illness and
the appearance of symptoms.
Modulation process of varying a pure waveform for the
purpose of encoding information.
Near field region near an emitter where the relationship
between the electric and magnetic components of an
electromagnetic field is complex.


Phase modulation encoding of information by varying
the phase of the carrier waveform.
Pulse modulation regular interruptions to transmissions
through which a carrier frequency may be shared by
multiple users, eg TDMA.
Odds ratio ratio of the odds of disease occurrence in a
group with exposure to a factor to that in an unexposed
group. Within each group, the odds are the ratio of the
numbers of diseased to non-diseased individuals.
Sham exposure replication of exposure conditions where
the radiofrequency energy does not reach the target site.
Specific energy absorption rate (SAR) rate of
absorption of electromagnetic energy in a unit mass of
tissue; usually expressed in W/kg.
Time division multiple access (TDMA) system that
divides each frequency band into a number of timeslots,
each allocated to a single user. It allows several users
to operate on the same frequency band. The effect on
the transmission is often referred to as pulse modulation
because the signal is emitted in bursts or pulses.

Abbreviations
AM

Amplitude modulation

APC

Adaptive power control

BCCH

Broadcast control channel

CDMA

Code division multiple access

CPICH

Common pilot channel

CW

Continuous wave

DTX

Discontinuous transmission

EEG

Electroencephalogram

EMF

Electromagnetic field

FM

Frequency modulation

GSM

Global system for mobiles

RF

Radiofrequency

rms

root mean square

Traffic channel frequency channel that is used to
transmit call information from a base station to the
user(s). Output will vary with the number of users.

SAR

Specific energy absorption rate

TCH

Traffic channel

Transmission movement of radiofrequency energy away
from a source.

TDMA

Time division multiple access

TETRA

Terrestrial trunked radio

UMTS

Universal mobile telecommunications system

Waveform temporal and spatial structure of an
electromagnetic wave.

25

Appendix A
MTHR Phone Exposure System Specification

As we were supporting a number of provocation studies
we decided that it would aid the interpretation of
results if all exposures were made with standardised
exposure systems. The Home Office TETRA Programme,
which was set up shortly after the MTHR Programme,
also decided to standardise on the TETRA version of our
phone exposure system.
The considerations underlying our choice of exposure
system design and the exposure conditions used are
explained in Section 5 of the report. Brief descriptions
of the exposure systems have been published in
research papers and final reports from individual
projects. However, we are aware that no detailed
description of the phone exposure systems has yet been
published and so we are providing one here. A detailed
description of the base station exposure system is
provided in Appendix B.

intention to use this in the studies initially supported by
the MTHR Programme.
It was possible to divert power in either variant to an
internal load to provide sham RF exposure conditions
with heating and low frequency magnetic fields similar
to the exposure modes. The power could also be
diverted, via approximately 20 dB of attenuation, to
a power monitoring port (an SMA socket on the top of
the handset), where power in either CW or GSM/TETRA
mode could be measured with a suitable power meter.
A GSM handset is shown in Figure A1; the TETRA handset

The phone exposure systems were commissioned
from Dr Phil Chadwick at MCL, who also arranged
ongoing maintenance and calibration. The general
description of the system and information on
dosimetric assessments given below were adapted
from information provided by Dr Chadwick. MCL
subcontracted the construction of the devices to the
University of York. Professor Myles Capstick (now at
the IT’IS Foundation in Zurich) who led this work kindly
provided the technical description below.
(a)

(b)

General description of the phone
exposure system
The exposure system consisted of a self-contained,
headband-mounted generic handset. There were no
external connections and the devices required no
RF expertise for operation. The handsets were capable
of radiating power with GSM/TETRA modulation
(depending on variant), or without modulation
(continuous wave, CW mode). DTX capability was
also provided for the GSM handsets, but there was no

26

(c)
FIGURE A1 (a) front, (b) back and (c) control switches
of the GSM phone exposure system

Appendix A MTHR Phone Exposure System Specification

looks identical apart from the antenna, which has to be
longer as a result of the lower frequency of operation.

allow them to ‘settle’ before generating exposures, so
that the SAR levels would remain stable.

There were 27 possible different emission modes:
100% power, 50% power and 25% power; three possible
modulation regimes (GSM/TETRA, CW and DTX); and
three routes for the power (antenna, internal load or
power monitoring port). These modes were randomly
and multiply assigned to various hexadecimal values.
There were 10 hex values for each mode, apart from
the power-monitoring modes, which each had a unique
hex value. The hex modes were set using the two rotary
switches on the back of each handset, labelled MSB
and LSB. Each hex value had the form nn, where n
in each case was a number between 0 and 9 or a
letter between A and F. So to set the hex value 1F, for
example, the left-hand (MSB) dial was set to ‘1’ and the
right-hand (LSB) dial was set to ‘F’.

Three spare batteries and one charger were supplied
with each handset.

The mean power in the GSM and CW modes was the
same: this was to ensure that exposures did not exceed
the International Commission on Non-Ionizing Radiation
Protection (ICNIRP) guidelines in CW mode. However,
the consequence of this was that the radiated power
in CW mode was approximately one-eighth of the peak
power in GSM mode (one-quarter for TETRA). The
mean radiated power of the handsets was 250 mW; the
peak radiated powers were 1 W for the TETRA units and
2 W for the GSM units.
In GSM/TETRA mode, the signals produced by the
exposure system had the lower frequency modulation
components arising from the super- and hyperframe structure as well as the frame-related burst
modulation. More detail on the output of the systems is
given in the technical description below.
The currents drawn by the handsets in GSM/TETRA and
CW modes were matched so that the heating of the
cases was comparable. Tests by MCL and the University
of Sheffield indicated that the case temperatures were
similar to within 1° celsius.
An audible battery warning sounded when there were
only a few minutes of useful battery life left. The
output of the handset was stable to within ± 0.5 dB
between three minutes from switch-on of a new battery
and three minutes after the battery warning. The
research teams were advised to leave units switched on
for around three minutes after fitting a new battery to

Mounting the exposure systems
The magnitude and spatial distribution of deposited
energy from the exposure systems are critically
dependent on the position of the unit relative to the
head (as it would be for a mobile phone). In order to
make the results of studies meaningful, it is obviously
important to standardise exposures between:
a

different trials with the same subjects,

b

different subjects within a trial,

c

different trials within a study,

d

different studies.

Standardisation of exposure was partly achieved
through the use of identical and properly calibrated
exposure systems. However, it was also important to
ensure that the systems were always mounted in the
same position. This was achieved through the use of a
cradle that fitted around the subject’s head and held
the phone in position.
The cradle permitted the exposure systems to be
mounted in either right- or left-handed positions. It was
designed to facilitate positioning of the unit against the
subject’s head in the CENELEC ‘cheek’ geometry, one of
two standard assessment geometries for mobile phones.
For the left side of the head, this has the antenna
touching or within a few millimetres of the head, above
and slightly behind the ear, as illustrated in Figure A2.
The mounting bracket on the headband incorporated
different position settings so that the exposure system
could be placed in the CENELEC ‘cheek’ position for
different subjects. Guidance was provided to the
research groups to enable them to correctly position
the units.
As the exposure systems were not symmetrical, it was
necessary to use a slightly different positioning system
when mounting on the right side of the head. In this
case a spacer kit was used to displace the unit by
approximately 40 mm.

27

dsets will handsets will beon the headset the either right- or left-handed left-ha
The be mountable mountable on in headset in either right- or
The handset will be mounted against the subject's head in the CENELEC CEN
positions. The handset will be mounted against the subject's head in the
geometry: TelecommunicationsthisHealthonestandard twoReport 2012 geometries for
”cheek" this is one ofand istwo of Programme standard assessment geometrie
geometry:
the Research the assessment
Mobile
hones.
mobile phones.

Centre line

Centre line

FIGURE A2 CENELEC ‘cheek’ geometry

256
Technical CENELEC "cheek" measurement mode numbers which were allocated
CENELEC1: description of the phone exposure
Figure "cheek" measurement position possiblepositionoperation. In this way the
randomly to the modes of

system

experimenter could have no knowledge of the mode of
The requirement was for an exposure system solution
operation being selected. The DC power consumption
to provide controlled exposure of volunteers with
was to be identical whatever the mode, so that the
characteristics representative of a real mobile phone
operating temperatures would be identical whatever
handset. Previous exposure system solutions involved
the mode (except for the unused DTX mode).
a rack of equipment connected to a test antenna
placed near the subject’s head. However, a key feature
of a mobile phone is that it is physically small and
TABLE A1 Overview of mode and output destination
Microwave Consultantselement counterpoise Limited, 2170388 (England).
Registration No 2170388 (England).
this constrains the Microwave Consultants
antenna Limited, Registration Nooptions for GSM and TETRA versions of exposure
systems
dimensions, it being important to remember that the
System
Mode
Destination
antenna is not only the helical (or other element) but
GSM
CW
Antenna
also the rest of the phone against which it is fed. The
connection of a cable to any antenna can therefore
DTX
Internal load
dramatically alter the current distribution because the
Test port
cable artificially extends the counterpoise. Therefore,
TETRA
CW
Antenna
we set about developing a range of representative
DTX
Internal load
devices built into mobile phone enclosures that could
provide specified power levels corresponding to given
specific energy absorption rates (SAR) with GSM and
For the GSM handsets, modes were mapped to all
TETRA type signals or continuous wave (CW) signals. In
destinations giving nine possible operation modes. The
addition, these modulated or CW signal powers were
three test port modes were used only for diagnosis
to be delivered either to the antenna, an internal
and were mapped to only one mode number on the
load or a test port (to allow regular measurement of
hexadecimal switches. For the TETRA handsets, modes
output power and hence verify continued operation)
were mapped to all destinations, giving six possible
(Table A1). An additional requirement was that the
operation modes. The two test port modes were used
handset should have the same power dissipation
only for diagnosis and were mapped to only one position
whatever the mode of operation, so that the exposure
each on the hexadecimal switches.
mode could not be determined from the temperature
of the handset. For the GSM phone a discontinuous
The output power was tuned in the GSM, TETRA and
transmission (DTX) mode was also included for future
CW cases to be at the ICNIRP limit for SAR but never
use. The particular mode of operation was set by the
above, when all uncertainties were taken into account.
operator using two hexadecimal switches allowing

dsetsThe handsets will by MCL and by MCL andat the Universitythe University of
will be specified be specified constructed constructed at of York.
a demonstrabledemonstrable of constructing simulated handsets andhandsets an
York has a track record track record of constructing simulated has
y supplied a UMTS-typeadevice to MCL for a DTI-funded a DTI-funded project.
previously supplied UMTS-type device to MCL for project.

28


1A

Mode select
switches
Phase locked loop

PIC
microcontroller

FPGA

÷N

φ

VCO

Reference
oscillator

LUT

Test port

Load

Control
Address

Antenna
Data

ADC

Σ

LPF

Atten

PA

LPF

Quadrature modulator

FIGURE A3 System architecture for phone exposure systems

All devices were measured at the same accredited
laboratory to maintain consistency between them.
The DTX mode pulse power level was the same as for a
single pulse in the GSM mode.

System architecture
Both devices used essentially the same architecture
(Figure A3) involving a look-up table (LUT) feeding an
analogue-to-digital converter (ADC) producing in-phase
and quadrature signals for direct modulation of the
carrier. The modulated carrier level was then set and
the output amplified up to the required level.
The key differences between the two handset variants
were the different frequencies of operation and hence
RF components and different data in the LUT, sample
rates for the ADCs and anti-aliasing filter bandwidths.

Modulation and look-up tables
GSM modulation can be facilitated using two common
methods. The first is direct modulation of the transmit
VCO using Gaussian filtered data, and the second is a
quadrature method using the property that frequency
is the rate of change of phase. The second method is
much more easily controlled and was adopted for the
GSM transmitter here. The modulation process is shown
in Figure A4.
Representative data were generated and the in-phase
(I) and quadrature (Q) signals calculated by integrating
and then filtering the signals to obtain a phase angle

cos(ωt)
cos
Data

dt
sin

+
-

Σ

sin(ωt)

FIGURE A4 Modulation process

which was then used as the argument for sine and
cosine functions to calculate the I and Q values. The
resultant constant amplitude modulating signal can be
seen in the phasor diagram (Figure A5).
The I and Q values required to produce the modulation
were stored in the LUT in the handset in blocks equal
in length to one timeslot. The data in each block were
conditioned to provide the ramping function at the
start and end of a slot as given in the GSM specification,
to ensure there were no transient spectral components
outside the nominal channel.
In the case of p/4 DQPSK modulation, a pseudo-random
bit stream was generated and each pair of bits used as
the index to a 2 x 2 matrix indicating the differential
phase shift such that ∆f was given by

∆φ =

( )
π
4
−π
4

3π
4
−3π
4

29


I and Q amplitude

1

0

1

(a)

(a)

0

200
Sample

400

1.5
Amplitude

( x, z, y )

1
0.5
0
0.5

4

3

2

1
0
1
Normalised time

2

3

4

(b)

(b)

FIGURE A5 Constant amplitude modulation signal, as:
(a) 3-dimensional and (b) 2-dimensional phasor diagrams

FIGURE A6 (a) variation in I and Q amplitudes and
(b) the same data transformed and shown in the time
domain

During any given symbol period k, f was calculated
as φk = φk-1 + ∆φk and from this the nominal limiting
values of the in-phase and quadrature amplitudes
were calculated. The nominal I and Q amplitudes
were multiplied by impulse trains at the symbol
rate to produce impulse trains of the correct I and Q
amplitudes (Figure A6). These impulse trains were then
convolved with the impulse response of the root-raised
cosine filter with r = 0.35. The filter impulse response
was given by

in the specification, to ensure there were no transient
spectral components outside the nominal channel.

[

sin π(1 − r)
h(t) =

π

]
[
[ ( )]

t
t
t
+ 4r
cos π(1 + r)
T
T
T
t
t
1 − 4r
T
T

]

2

The whole modulation process is illustrated in
Figure A7.
The resultant modulating waveforms are shown
graphically in Figure A8. It is these calculated
modulation waveforms that were stored in the LUT in
the exposure system in blocks equal to one timeslot.
The data in each block were conditioned to provide the
ramping function at the start and end of a slot as given

30

Exposure system spectra and bursts
The spectral content of the handsets when in the
modulated modes were measured and compared to the
spectral masks for the standards (Figures A9 and A10 for
GSM and TETRA, respectively). The GSM simulated signal
source conformed well to the standard and the TETRA
handset exceeded the permitted levels for a real device
when the signal was lower than 1/200,000th of the peak
level. This was mainly due to spurious sidebands on the
phase-locked loop synthesiser output. Both handsets
were passed by Ofcom for use within the MTHR project.

Antennas
For both the TETRA and GSM handsets, external helical
antennas were used so that SAR levels towards the top
of the allowable range could be readily achieved with
the peak RF powers available. The helical antennas were
tuned such that they were well matched in proximity to
the head of a user. The antennas showed typical return
losses better than 10 dB, and not worse than 7 dB.
However, the exact match was dependent on the precise
positioning of the handset with respect to the head.


Signaling pulse
1.5

LUT

Amplitude

S/P

Data

1
0.5
0
0.5

4

3

2

1
0
1
Normalised time

+

2

3

4

cos(ωt)
cos

sin
i*h

Unit impulse train
at the symbol rate

+
-

q*h

Σ

sin(ωt)

FIGURE A7 Modulation process

Blinding

I and Q modulation

1

0

–1

(a)

0

100

200

300
Sample

400

500

(b)
FIGURE A8 Modulating waveforms: (a) displayed
graphically and (b) in the form of a phasor diagram

The basic principle behind the blinding was the random
allocation of the 256 possible switch positions between
the possible device modes, such that each mode had
approximately the same number of random settings. The
experimenters would have no knowledge of this mapping
function and only the principal investigator who
planned the experimental campaign would have access.
There was no indication on the handset of the mode
selected for a given switch position. The only switch
positions known to the experimenters were those that
mapped the output of the device to the test port for
the regular verification that the device continued to be
operational by measurement of the sampled power.
In the different modes of operation the handsets would
consume different amounts of power, which would result
in different handset temperatures if not compensated.
To ensure similar heating in all modes, resistors were
included in the device to dissipate additional power in
the higher efficiency modes and bring the total to the
same. The value was based initially purely on DC power
from the battery, and then optimised based on infrared
thermometry of the handset case in the different
modes, to ensure that heating would not provide a clue
as to the exposure state.

31


−10

−20

−20

Relative amplitude (dB)

0

−10
Relative amplitude (dB)

0

−30
−40
−50
−60

(a)

−40
−50
−60
−70

−70
−80

−30

−80
887.5

888

888.5
889
Frequency (MHz)

889.5

(a)

380.90

380.95

381.00
381.05
Frequency (MHz)

381.10

(b)

(b)

(c)

(c)

FIGURE A9 Measured outputs from GSM exposure
system: (a) in the frequency domain; and (b) and (c) in
the time domain, showing an individual timeslot and a
complete frame, respectively

FIGURE A10 Measured outputs from TETRA exposure
system: (a) in the frequency domain; and (b) and (c) in
the time domain, showing an individual timeslot and a
complete frame, respectively

32


Dosimetry and calibration
Dosimetric assessment and ongoing calibration of the
exposure systems was carried out by Phil Chadwick
at MCL.

Dosimetric assessment
Assessment of exposure from each handset was
made using a robot-mounted, computer-controlled
miniaturised probe to map the internal electric field
strengths in a headshell phantom filled with tissuesimulating material. The tissue-simulating materials
were formulated and tested to ensure that they
were matched to tissue electrical conductivity and
permittivity at the frequency of operation of the
handset, as specified in CENELEC/IEEE standards.
The dosimetry system and procedures were consistent
with CENELEC EN50360:1 specifications for the SAR
testing of mobile phone handsets. The standardised
exposure geometry used for mounting the units on each
subject’s head facilitated dosimetric assessment using

(a)

AR peak close to antenna

standard CENELEC protocols. SARs were assessed in a
fully calibrated test facility with UKAS accreditation.
Assessments confirmed that the peak SAR occurred
close to the antenna for both the GSM and TETRA
variants (see Figure A11) and had a value of
1.3 ± 0.4 W/kg when averaged over 10 g of contiguous
tissue. The spatial peak SAR when averaged over 1 g of
contiguous tissue was typically 4−5 W/kg.
The peak SAR from the body of the unit was
typically 0.3−0.4 W/kg when averaged over 10 g of
contiguous tissue. The spatial peak SAR in sham mode
was less than the sensitivity of the measurement
system (0.001 W/kg).

Ongoing maintenance and calibration
of experimental systems
When we commissioned the exposure systems we
were aware that there would be an ongoing need for
maintenance and calibration, which would necessitate
the return of systems to MCL. To ensure that this
process did not affect the progress of individual
research studies, we procured spare copies of each
variant of the exposure system. When units were due
for maintenance and calibration, exchange units were
provided to the research teams so that their work could
continue unhindered.
As discussed in the technical description above, the
units were designed with a test port that could be
used to calibrate the output power of the system.
Calibrations were performed using Hewlett Packard
HP432A power meters equipped with 300 mW
thermistor sensors. This meter/sensor combination
measures the rms power of both pulsed and CW signals.
The power meters were themselves calibrated annually
by Ben Loader at the National Physical Laboratory,
who had loaned them in the first place. Hence the
calibration of the exposure systems was traceable to
the national standards maintained by NPL.

SAR distributio

onstruction
he handsets are manufactured in a way that gives inhere
pected, though, that reasonable care will be taken with the e
boratory equipment).
(b)
FIGURE A11 Spatial distributions of SAR close to:
(a) antenna) and (b) unit body

articular care is needed when connecting the power meter, an
33
distribution are handset Researchers are provided with
hen batteries frominstalled. body
ese procedures.

Appendix B
MTHR Base Station Exposure System Specification

This appendix provides a technical description of
the base station exposure system. As for the phone
exposure system, we have explained in Section 5 of
the report the considerations underlying our choice of
exposure system design and exposure conditions. We
again had a requirement to generate different types
of signal (GSM/UMTS or TETRA). However, in this case
the two studies that used the different signals followed
each other. So, it was possible to have the supplier
modify the system to convert it from a GSM/UMTS
system to one generating a TETRA signal.
The system was designed by Bachir Belloul at Red‑M
Services Ltd and the technical description given below
is taken from his technical reference manual. The
description is given for the TETRA version of the system.

Technical description of the base
station exposure system
This section describes the electromagnetic
transmission system designed, implemented and installed
by Red-M Services Ltd at the University of Essex. The
system was developed as part of the MTHR Programme
on the effects of electromagnetic exposure on
hypersensitive individuals.
This system was designed to replicate real-world TETRA
base station emissions as closely as practically possible,
with repeatability of the transmit signal and control
over the transmit parameters given high consideration
for the purpose of the experiments for which the
system was designed.

Transmit system description
Figure B1 shows the system set-up. As in the previous
GSM/UMTS system, the current TETRA system’s main
component was the SMU200 digital signal generator
from Rohde & Schwarz. The signal generator was

34

controlled by a dedicated PC via the Ethernet port.
The PC also acted as a client station for the operating
researcher to run the tests and daily checks.

System set-up
The RF output of the SMU200 was connected directly to
a 10 W ETSA power amplifier optimised to operate at
TETRA frequencies. The amplifier enabled the signal to
be set to the correct levels to meet the requirements
in terms of power density at the subject’s area in the
screened room.
The through-line microwave power meter (R&S NRP-Z11)
fed the system’s output power and return power back
to the PC (via the serial port) for a continuous check
of the transmitted power during the tests. The power
meter reading was checked against a tolerance of 1 dB
set by Red-M. Any deviation from the set power larger
than 1 dB sent a warning signal back to the researcher
via the user interface.
The digital signal generator, power amplifier and power
meter were housed in a special rack.
The transmission system was linked to the transmit
antenna by an LDF 4-50 coaxial cable. The cable was
shielded and had a low loss characteristic.
Inside the screened room, the system radiated through
a broadband (400 MHz to 3 GHz) log-periodic antenna
(R&S HL040), mounted on a wooden tripod. The HL040
antenna had a 3 dB cutoff beamwidth of around
40° either side of the antenna’s bore sight direction
(Figure B2) and a high front-to-back ratio (>15 dB
between 450 MHz and 3 GHz).
The subject’s area was set at a distance of about 5 m
from the antenna’s centre of radiation and was 1 m
across, giving an aperture of around 5.5° on either side,
providing an almost constant gain (in free space) across
the subject’s area.

Appendix B MTHR Base Station Exposure System Specification

Ethernet

SMU200 signal generator

TETRA amplifier

RF in
RF inRF out

RF out

ETSA 10 W power amplifier
LDF 4-50
feeder cable
to antenna

Through-line power meter
Serial port
Control PC

PS2 cables

FIGURE B1 TETRA system setup

Characteristics of the transmit signal
The characteristics of the transmit signal are
summarised in Table B1.
TABLE B1 Transmit frequencies of the system
Parameter

Value

Frequency

420 MHz

Signal type

TETRA

Number of channels

1

Channel bandwidth

25kHz

Multiple access

TDMA

Modulation

p/4 DQPSK

Simulating the TETRA waveform
FIGURE B2 Radiation pattern of the HL040 antenna at
400 MHz

Although the TETRA standard (ETSI EN 300 392-2) is very
clear with regard to the structure of the transmitted
signal, there remains a large element of freedom in the
way different manufacturers of base stations can set the
various transmit parameters. For example, transmission
modes (continuous or burst), the occurrence of the
control channels or the type of modulation will be set
according to a particular operator’s requirements.
One other element of variability in the waveform
consists of whether or not traffic is carried on the
channel. This aspect was found to have a profound
effect on the shape of the waveform.

35


To illustrate the impact of traffic on the waveform,
Figure B3 shows what two successive TDMA frames will
look like when captured on a spectrum analyser. The
figure shows timeslots 1 to 4 of the two successive
frames (ie timeslots 1,2,3,4,1,2,3,4). It should be noted
that on timeslot 1 of each of the frames, there is no
preamble (marked as FCCH, or frequency correction
channel on timeslot 2 of frame 1 in the figure), while
the remaining three slots in the frame do have an
FCCH. The FCCH is used by the system to synchronise
the transmit frequency.
In the TETRA standard, the FCCH is transmitted only
if there is no traffic in the timeslot (incidentally, the
FCCH is not a logical channel as such, but is defined as
the frequency synchronisation block in the continuous
downlink burst). In the example shown, none of slots 2,
3 or 4 of the two successive frames shown carries
traffic. If any of slots 2, 3 or 4 were carrying traffic,
then there would be no marked interval at the start
of the slots, resulting in a continuous, ‘uninterrupted’
waveform being transmitted across the frame.
Timeslot 1 does, however, carry traffic and so has no
FCCH, as observed on the figure. Control channels also
do not have an FCCH, but these do not occur on every
frame and therefore have a lower repeat rate.
This situation had obvious implications for system
implementation as the presence of traffic will have
a direct repercussion on the presence or not of the
various harmonics of the timeslots (the 17.6 Hz and the
70.5 Hz harmonics in particular).

25

Power (milliwatts)

20

15

1 frame = 56.7 ms
1

2

3

Timeslot numbers
4

1

2

3

4

FCCH

10

5
0
000 0.0142 0.0284 0.0425 0.0567 0.0709 0.0851 0.0992 0.1134
0.0
Time (s)

FIGURE B3 Laboratory-generated TETRA waveform
showing two successive frames of four timeslots each

36

In agreement with the research team, Red-M
implemented a signal containing balanced periods of
traffic and non-traffic timeslots (over the period of the
tests, 50% of the timeslots carried traffic and 50% did
not). The traffic profile was generated according to a
Markov process, similar to the one used for simulating
the traffic in the GSM system.

System calibration
The first calibration (pre-commissioning) of the system
was performed on 9 May 2007 following the guidelines
set in the system installation guide. Subsequent
calibrations were carried out at six-monthly intervals
during the experimental period in order to confirm the
stability of the system.
This section describes the calibration set-up and the
results of the initial calibration.

Calibration set-up
Figure B4 illustrates the layout of the screened room.
During the calibration process, the doors were closed and
the probe positioned 4.95 m from the tip of the antenna
and fixed to a plastic tripod that was moved laterally
along the walkway, which is shown as a thick line.
Following each calibration measurement, the probe
was re-positioned horizontally along the walkway by
moving the tripod to the right (or to the left), as shown
in Figure B5. Five measurement positions were used
for each height of the probe, each separated by 25 cm.
The central position was used as the reference position
when reporting the results given below.
The tripod used for the calibration measurements was
made of a non-conductive material. Once measurements
at all five positions were completed at a given height,
the tripod height was re-adjusted and the five lateral
positions measured once more. The measurements
were performed with the probe set at heights of 65 cm,
90 cm, 1.15 m and 1.4 m, as shown in Figure B5.
Measurements were made at a total of 20 positions,
corresponding to a ‘window’ of size 1 m in width by
75 cm in height, representing approximately a crosssectional area covering a subject’s upper body, to
include the upper legs, the abdomen, torso, shoulders
and head when seated.

Appendix B MTHR Base Station Exposure System Specification

Screened room

Door

4.95 m

The measurements were performed using an EMR300
probe, manufactured by Narda. The settings used on
the EMR300 are given in Table B2. The measured values
were then converted to mW/m2 to be compared with
the specifications set by the PMC.
TABLE B2 Settings on the EMR 300 power meter
Parameter

Door to
lobby

FIGURE B4 Layout of the screened room during
calibration
0.2
5m

0.65 m

1.40 m

Probe positions

Probe on tripod

2 minutes

Measurement type

Window to
researcher room

Average

Averaging time

Walkway

1.0034

Power setting

Probe position

Value/comment

Calibration factor

Antenna

Power density

Probe barcode

4274

Meter barcode

628

Units

W/m2

Power density levels measured at each of the
probe positions are given in Table B3. The average
power density value was calculated over the entire
measurement area and found to be 11 mW/m2. The
initial system requirements set the target power
density level at the subject’s area to 10 mW/m2, so
this was approximately 0.4 dB out from the target
level but well within the 3 dB variability tolerated by
the requirements.
TABLE B3 Results of the measured power density at
each probe position on 9 May 2007
Measured power density (mW/m2)
Position

Calibration results
For the calibration, the output power was initially set
at the level required to provide a power density of
10 mW/m2 at the centre of the subject’s ‘window’.
Measurements of the power density at the positions
described above were carried out and the average
power across all the measurements estimated.
An adjustment factor of the output power was then
calculated and the power adjusted accordingly.
A second set of measurements was carried out across
the entire window and the following results are those
of the second set of measurements.

3.50

22.50

38.40

7.20

0.90

1.15 m

3.10

22.40

37.50

6.30

3.60

0.90 m
FIGURE B5 Positions of the probe during the
measurements

+25 cm +50 cm

1.40 m
Walkway

−50 cm −25 cm 0 cm

1.70

13.60

23.20

5.20

1.50

0.65 m

3.90

9.60

11.00

4.00

1.80

However, the variability within the window remained
large, with a range of values measured between
0.9 mW/m2 (on the top right) and 38.4 mW/m2
(top centre).
This variability was highlighted by Red-M and an action
was put on the contractors who designed and installed
the internal absorptive material. The subsequent
addition of more absorber material reduced the
variability, as can be seen in Table B4, which gives
the results obtained on 11 January 2008. Following
this modification, the average power density over

37


the measurement area dropped to around 8 mW/m2
and remained within 1 dB of the target level for the
remainder of the study.
Following the initial calibration of the system, Red-M
performed a routine check of the system in order to
establish the forward power and return loss recorded by
the system’s through-line power meter. The results of
the check are given in Table B5.

TABLE B4 Results of the measured power density at
each probe position on 11 January 2008
Measured power density (mW/m2)
Position

−50 cm −25 cm 0 cm

+25 cm +50 cm

1.40 m

4.50

15.50

10.70

8.90

6.70

1.15 m

4.40

9.80

18.40

12.40

6.90

0.90 m

4.40

7.30

15.80

7.50

5.10

0.65 m

2.80

3.20

7.90

4.30

2.90

TABLE B5 Forward power and return power recorded
during the calibration on 9 May 2007
Parameter

24.14

Return power

38

Measured power (dBm)

Forward power

16.89

Appendix C
Publications Arising from the MTHR Programme

Ahmed I, Abd-Alhameed R, Excell P Hodzic V, Davis C,
,
Gammon R and Balzano Q (2010). Absence of nonlinear
responses in cells and tissues exposed to RF energy at
mobile phone frequencies using a doubly resonant cavity.
Bamiou DE, Ceranic B, Cox R, Watt H, Chadwick P
and Luxon LM (2008). Mobile telephone use effects on
peripheral audiovestibular function: a case-control study.
Barker AT, Jackson PR, Parry H, Coulton LA, Cook GG and
Wood SM (2007). The effect of GSM and TETRA mobile
handset signals on blood pressure, catechol levels and
heart rate variability. Bioelectromagnetics, 28(6), 433−8.
Barnett J. Timotijevic L, Shepherd R and Senior V (2007).
Public responses to precautionary information from the
Department of Health (UK) about possible health risks from
mobile phones. Health Policy, 82(2), 240−50.
Barnett J, Timotijevic L, Vassallo M and Shepherd R
(2008). Precautionary advice about mobile phones: public
understandings and intended responses. J Risk Res, 11(4),
525−40.
Cardis E, Richardson L, Deltour I, Armstrong B,
Feychting M, Johansen C, Kilkenny M, McKinney P
,
Modan B, Sadetzki S, Schüz J, Swerdlow A, Vrijheid M,
Auvinen A, Berg G, Blettner M, Bowman J, Brown J,
Chetrit A, Collatz Christensen H, Cook A, Hepworth S,
Giles G, Hours M, Iavarone I, Jarus Hakak A, Klaeboe L,
Krewski D, Susanna Lagorio S, Lönn S, Mann S, McBride M,
Muir K, Nadon L, Parent M-E, Pearce N, Salminen T,
Schoemaker M, Schlehofer B, Siemiatycki J, Taki M,
Takebayashi T, Tynes T, van Tongeren M, Vecchia P Wiart J,
,
Woodward A and Yamaguchi N (2007). The INTERPHONE
study: design, epidemiological methods, and description of
the study population. Eur J Epidemiol, 22(9), 647−64.

Cardis E, Deltour I, Vrijheid M, Combalot E, Moissonnier M,
Tardy H, Armstrong B, Giles G, Brown J, Siemiatycki J,
Parent ME, Nadon L, Krewski D, McBride ML, Johansen C,
Collatz Christensen H, Auvinen A, Kurttio P Lahkola A,
,
Salminen T, Hours M, Bernard M, Montestrucq L, Schüz J,
Berg-Beckhoff G, Schlehofer B, Blettner M, Sadetzki S,
Chetrit A, Jarus-Hakak A, Lagorio S, Iavarone I,
Takebayashi T, Yamaguchi N, Woodward A, Cook A,
Pearce N, Tynes T, Blaasaas KG, Klaeboe L, Feychting M,
Lönn S, Ahlbom A, McKinney PA, Hepworth SJ, Muir KR,
Swerdlow AJ and Schoemaker MJ (2010). Brain tumour
risk in relation to mobile telephone use: results of the
INTERPHONE international case-control study. Int J
Epidemiol, 39(3), 675−94.
Cardis E, Deltour I, Vrijheid M, Evrard AS, Sanchez M,
Moissonnier M, Armstrong B, Brown J, Giles G,
Siemiatycki J, Nadon L, Parent ME, Krewski D, McBride MM,
Johansen C, Christensen HC, Auvinen A, Kurttio P
,
Lahkola A, Salminen T, Hours M, Bernard M, Montestruq L,
Schüz J, Blettner M, Berg-Beckhoff G, Schlehofer B,
Sadetzki S, Chetrit A, Jarus-Hakak A, Lagorio S, Iavarone I,
Takebayashi T, Yamaguchi N, Woodward A, Cook A,
Pearce N, Tynes T, Klæboe L, Blaasaas KG, Feychting M,
Lönn S, Ahlbom A, McKinney PA, Hepworth SJ, Muir KR,
Swerdlow AJ and Schoemaker MJ (2011). Acoustic neuroma
risk in relation to mobile telephone use: results of the
INTERPHONE international case-control study. Cancer
Epidemiol, 35(5), 453−64.
Cinel C, Boldini A, Russo R and Fox E (2007). Effects of
mobile phone electromagnetic fields on an auditory order
threshold task. Bioelectromagnetics, 28(6), 493−6.
Cinel C, Boldini A, Fox E and Russo R (2008). Does the use
of mobile phones affect human short-term memory or
attention? Appl Cogn Psychol,22(8), 1113−25.
Cinel C, Russo R, Boldini A and Fox E (2008). Exposure
to mobile phone electromagnetic fields and subjective
symptoms: a double-blind study. Psychosom Med, 70(3),
345−8.
Cooke R, Laing S and Swerdlow AJ (2010). A case-control
study of risk of leukaemia in relation to mobile phone use.
Br J Cancer, 103(11), 1729−35.
Cooper TG, Mann SM, Khalid M and Blackwell RP (2006).
Public exposure to radio waves near GSM microcell and
picocell base stations. J Radiol Prot, 26(2), 199−211.

39


Dawe AS, Smith B, Thomas DWP Greedy S, Vasic N,
,
Gregory A, Loader B and de Pomerai D (2006). A
small temperature rise may contribute towards the
apparent induction by microwaves of heat-shock gene
expression in the nematode, Caenorhabditis elegans.
Dawe AS, Nylund R, Leszczynski D, Kuster N, Reader T and
de Pomerai D (2008). Continuous wave and simulated GSM
exposure at 1.8 W/kg and 1.8 GHz do not induce hsp16-1
heat-shock gene expression in Caenorhabditis elegans.
Dawe AS, Bodhicharla RK, Graham NS, May ST, Reader T,
Loader B, Gregory A, Swicord M, Bit-Babik G and
de Pomerai DI (2009). Low-intensity microwave irradiation
does not substantially alter gene expression in late larval
and adult Caenorhabditis elegans. Bioelectromagnetics,
30(8), 602−12.
Dimbylow P Khalid M and Mann S (2003). Assessment of
,
specific energy absorption rate (SAR) in the head from a
TETRA handset. Phys Med Biol, 48, 3911−26.
Elliott P Toledano MB, Bennett J, Beale L, de Hoogh K,
,
Best N and Briggs DJ (2010). Mobile phone base stations
and early childhood cancers: case-control study. BMJ, 340,
c3077 doi: 10.1136/bmj.c3077.
Eltiti S, Wallace D, Zougkou K, Russo R, Joseph S,
Rasor P and Fox E (2006). Development and evaluation
of the electromagnetic hypersensitivity questionnaire.
Eltiti S, Wallace D, Ridgewell A, Zougkou K, Russo R,
Sepulveda F, Mirshekar-Syahkal D, Rasor P Deeble R and
,
Fox E (2007). Does short-term exposure to mobile phone
base station signals increase symptoms in electrically
sensitive individuals? A double-blind randomised
provocation study. Environ Health Perspect, 115(11),
1603−8.
Eltiti S, Wallace D, Ridgewell A, Russo R and Fox E (2008).
Do the electromagnetic fields generated by mobile-phone
base-stations have short-term effects on health? A response
to commentaries. Environ Health Perspect, 116, 64−5.
Eltiti S, Wallace D, Ridgewell A, Zougkou K, Russo R,
Sepulveda F and Fox E (2009). Short-term exposure to
mobile phone base station signals does not affect cognitive
functioning or physiological measures in individuals who
report sensitivity to electromagnetic fields and controls.
Gabriel C and Peyman A (2006). Dielectric measurement:
error analysis and assessment of uncertainty. Phys Med
Biol, 51, 6033−46.

Hepworth SJ, Schoemaker MJ, Muir KR, Swerdlow AJ,
van Tongeren M and McKinney PA (2006). Mobile phone use
and risk of glioma in adults: a UK case-control study. BMJ,
332, 883−7.
Hillert L, Ahlbom A, Neasham D, Feychting M, Jarup L,
Navin R and Elliott P (2006). Call-related factors
influencing output power from mobile phones. J Expo Sci
Environ Epidemiol, 16(6), 507−14.
Kowalczuk C, Yarwood G, Blackwell R, Priestner M,
Sienkiewicz Z, Bouffler S, Ahmed I, Abd-Alhameed R,
Excell P Hodzic V, Davis C, Gammon R and Balzano Q
,
(2010). Absence of nonlinear responses in cells and tissues
exposed to RF energy at mobile phone frequencies using a
doubly resonant cavity. Bioelctromagnetics, 31(7), 556−65.
Lahkola A, Auvinen A, Salminen T, Raitanen J,
Schoemaker MJ, Christensen HC, Feychting M, Johansen C,
Klaeboe L, Lönn S, Swerdlow AJ and Tynes T (2007).
Mobile phone use and risk of glioma in five North European
countries. Int J Cancer, 120(8), 1769−75.
Lahkola A, Salminen T, Raitanen J, Heinävaara S,
Schoemaker MJ, Collatz Christensen H, Feychting M,
Johansen C, Klæboe L, Lönn S, Swerdlow AJ, Tynes T and
Auvinen A (2008). Meningioma and mobile phone use − a
collaborative case-control study in five North European
countries. Int J Epidemiology, 37(6), 1304−13.
Larjavaara S, Schüz J, Swerdlow A, Feychting M,
Johansen C, Lagorio S, Tynes T, Klaeboe L, Tonjer SR,
Blettner M, Berg-Beckhoff G, Schlehofer B, Schoemaker M,
Britton J, Mäntylä R, Lönn S, Ahlbom A, Flodmark O,
Lilja A, Martini S, Rastelli E, Vidiri A, Kähärä V, Raitanen J,
Heinävaara S and Auvinen A (2011). Location of gliomas in
relation to mobile telephone use: a case-case and casespecular analysis. Am J Epidemiol, 174(1), 2−11.
Nieto-Hernandez R, Rubin GJ, Cleare AJ, Weinman JA and
Wessely S (2008). Can evidence change belief? Reported
mobile phone sensitivity following individual feedback
of an inability to discriminate active from sham signals.
J Psychosom Res, 65(5), 453−60.
Nieto-Hernandez R, Williams J, Cleare AJ, Landau S,
Wessely S and Rubin GJ (2011). Can exposure to a
terrestrial trunked radio (TETRA)-like signal cause
symptoms? A randomised double-blind provocation study.
Occup Environ Med, 68(5), 339−44.
O’Connor RP Madison SD, Leveque P Roderick HL and
,
,
Bootman MD (2010). Exposure to GSM RF fields does not
affect calcium homeostasis in human endothelial cells, rat
pheocromocytoma cells or rat hippocampal neurons. PLoS
One, 5(7), e11828.
Parslow RC, Hepworth SJ and McKinney PA (2003). Recall
of past use of mobile phone handsets. Radiat Prot Dosim,
106(3), 233−40.

40

Appendix C Publications Arising from the MTHR Programme

Peyman A and Gabriel C (2010). Cole–Cole parameters for
the dielectric properties of porcine tissues as a function
of age at microwave frequencies. Phys Med Biol, 55,
N413−19.
Peyman A and Gabriel C (2012). Dielectric properties of
porcine glands, gonads and body fluids. Phys Med Biol, 57,
N339−44.
Peyman A, Gabriel C and Grant EH (2007). Complex
permittivity of sodium chloride solutions at microwave
frequencies. Bioelectromagnetics, 28, 264−74.
Peyman A, Holden S, Watts S, Perrott R and Gabriel C
(2007). Dielectric properties of porcine cerebrospinal
tissues at microwave frequencies: in vivo, in vitro and
systematic variations with age. Phys Med Biol, 52,
2229−45.
Peyman A, Gabriel C, Grant EH, Vermeeren G and
Martens L (2009). Variation of the dielectric properties
of tissues with age: the effect on the values of SAR in
children when exposed to walkie–talkie devices. Phys Med
Biol, 54, 227−41.
Quinlan T, Dudley S, Maung S, Deeble R and Fox E (2012).
Cognitive and physiological responses in humans exposed
to a TETRA base station. Bioelectromagnetics, 33(1),
23−39.
Rubin GJ, Das Munshi J and Wessely S (2005).
Electromagnetic hypersensitivity: a systematic review of
provocation studies. Psychosom Med, 67(2), 224−32.
Rubin GJ, Das-Munshi J and Wessely S (2005). A systematic
review of treatments for electromagnetic hypersensitivity.
Psychother Psychosom, 75, 12−18.
Rubin GJ, Hahn G, Everitt BS, Cleare AJ and Wessely S
(2006). Are some people sensitive to mobile phone
signals? A within-participants, double-blind, randomised
provocation study. BMJ, 332(7546), 886−91.
Rubin GJ, Cleare AJ and Wessely S (2008). Psychological
factors associated with self-reported sensitivity to mobile
phones. J Psychosom Res, 64(1), 1−9.
Rubin GJ, Nieto-Hernandez R and Wessely S (2010).
Idiopathic environmental intolerance attributed to
electromagnetic fields (formerly ‘electromagnetic
hypersensitivity’): an updated systematic review of
provocation studies. Bioelectromagnetics, 31(1), 1−11.
Russo R, Fox E, Cinel C, Boldini A, Defeyeter M, Mirshekar D
and Mehta A (2006). Does acute exposure to mobile phones
affect human attention? Bioelectromagnetics, 27(3),
215−20.
Schoemaker MJ and Swerdlow AJ (2009). Risk of pituitary
tumours in cellular phone users: a case-control study.
Epidemiology, 20(3), 348−54.

Schoemaker MJ and Swerdlow AJ (2009). Risk factors for
pituitary tumors: a case-control study. Cancer Epidemiol
Biomarkers Prev, 18(5), 1492−500.
Schoemaker MJ, Swerdlow AJ, Ahlbom A, Auvinen A,
Blaasaas KG, Cardis E, Christensen HC, Feychting M,
Hepworth SJ, Johansen C, Klaeboe L, Lönn S, McKinney PA,
Muir K, Raitanen J, Salminen T, Thomsen J and Tynes T
(2005). Mobile phone use and risk of acoustic neuroma:
results of the Interphone case-control study in five North
European countries. Br J Cancer, 93(7), 842−8.
Schüz J, Elliott P Auvinen A, Kromhout H, Poulsen AH,
,
Johansen C, Olsen JH, Hillert L, Feychting M, Fremling K,
Toledano M, Heinävaara S, Slottje P Vermeulen R and
,
Ahlbom A (2011). An international prospective cohort
study of mobile phone users and health (Cosmos): design
considerations and enrolment. Cancer Epidemiol, 35(1),
37−43.
See CH, Abd-Alhameed RA and Excell PS (2007).
Computation of electromagnetic fields in assemblages of
biological cells using a modified finite-difference timedomain scheme. IEEE Trans Microwave Theory Tech, 55(9),
1986−94.
Timotijevic L and Barnett J (2006). Managing the possible
health risks of mobile telecommunications: public
understandings of precautionary action and advice.
Health, Risk Soc, 8(2), 143−64.
Timotijevic L, Barnett J, Shepherd R and Senior V (2009).
Factors influencing self-report of mobile phone use: the
role of response prompt, time reference and mobile phone
use in recall. Appl Cogn Psychol, 23(5), 664−83.
Vermeulen R and Ahlbom A (2011). An international
prospective cohort study of mobile phone users and health
(Cosmos): design considerations and enrolment. Cancer
Epidemiol, 35(1), 37−43.
Vrijheid M, Cardis E, Armstrong BK, Auvinen A,
Berg G, Blaasaas K G, Brown J, Carroll M, Chetrit A,
Christensen HC, Deltour I, Feychting M, Giles GG,
Hepworth SJ, Hours M, Lavarone I, Johansen C, Klaeboe L,
Kurttio P Lagorio S, Lönn S, McKinney PA, Montestrucq L,
,
Parslow RC, Richardson L, Sadetzki S, Salminen T, Schüz J,
Tynes T and Woodward A, the Interphone Study Group
(2006). Validation of short term recall of mobile phone
use for the Interphone study. Occup Environ Med, 63(4),
237−43.
Deeble R and Fox E (2010). Do TETRA (Airwave) base
station signals have a short-term impact on health and
well-being? A randomized double-blind provocation study.
Environ Health Perspect, 118(6), 735−41.

41


Deebie R and Fox E (2012). Cognitive and physiological
responses in humans exposed to a TETRA base station
signal in relation to perceived electromagnetic
hypersensitivity. Bioelectromagnetics, 33(1), 23−39.

Kiuru A, Lindholm C, Heinävaara S, Ilus T, Jokinen P
,
Haapasalo H, Salminen T, Collatz Christensen H,
Feychting M, Johansen C, Lönn S, Malmer B,
Schoemaker MJ, Swerdlow AJ and Auvinen A (2008). XRCC1
and XRCC3 variants and risk of glioma and meningioma.
J Neurooncol, 88(2), 135−42.

Publications attributed to the
MTHR Programme but not related
to mobile phones

Malmer BS, Feychting M, Lönn S, Lindström S,
Grönberg H, Ahlbom A, Schwartzbaum J, Auvinen A,
Collatz‑Christensen H, Johansen C, Kiuru A, Mudie N,
Salminen T, Schoemaker MJ, Swerdlow AJ and
Henriksson R. Genetic variation in p53 and ATM haplotypes
and risk of glioma and meningioma (2007). J Neurooncol,
82(3), 229−37.

Bethke L, Murray A, Webb E, Schoemaker M, Muir K,
McKinney P Hepworth S, Dimitropoulou P Lophatananon A,
,
,
Feychting M, Lönn S, Ahlbom A, Malmer B, Henriksson R,
Auvinen A, Kiuru A, Salminen T, Johansen C,
Collatz Christensen H, Kosteljanetz M, Swerdlow A and
Houlston R (2008). Comprehensive analysis of DNA repair
gene variants and risk of meningioma. J Natl Cancer Inst,
100(4), 270−76.
Bethke L, Sullivan K, Webb E, Murray A, Schoemaker M,
Christensen HC, Muir K, McKinney P Hepworth S,
,
Dimitropoulou P Lophatananon A, Feychting M, Lönn S,
,
Ahlbom A, Malmer B, Henriksson R, Swerdlow A and
Houlston R (2008). The common D302H variant of CASP8
is associated with risk of glioma. Cancer Epidemiol
Bomarkers Prev, 17(4), 987−9.
Bethke L, Webb E, Murray A, Schoemaker M, Feychting M,
Lönn S, Ahlbom A, Malmer B, Henriksson R, Auvinen A,
Kiuru A, Salminen T, Johansen C, Christensen HC, Muir K,
McKinney P Hepworth S, Dimitropoulou P Lophatananon A,
,
,
Swerdlow A and Houlston R (2008). Functional
polymorphisms in folate metabolism genes influence
the risk of meningioma and glioma. Cancer Epidemiol
Bethke L, Webb E, Murray A, Schoemaker M, Johansen C,
Collatz Christensen H, Muir K, McKinney P Hepworth S,
,
Dimitropoulou P Lophatananon A, Feychting M,
,
Lönn S, Ahlbom A, Malmer B, Henriksson R, Auvinen A,
Kiuru A, Salminen T, Swerdlow A and Houlston R (2008).
Comprehensive analysis of the role of DNA repair gene
polymorphisms on risk of glioma. Human Mol Genet, 17(6),
800−805.
Bethke L, Sullivan K, Webb E, Murray A, Schoemaker M,
Christensen HC, Muir K, McKinney P Hepworth S,
,
Dimitropoulou P Lophatananon A, Feychting M, Lönn S,
,
Ahlbom A, Malmer B, Henriksson R, Swerdlow A and
Houlston R (2009). CASP8 D302H and meningioma risk:
a analyses of five case-control series. Cancer Lett, 273(2),
312−15.

42

Schoemaker MJ, Swerdlow AJ, Auvinen A, Christensen HC,
Feychting M, Johansen C, Klaeboe L, Lönn S, Salminen T
and Tynes T (2007). Medical history, cigarette smoking and
risk of acoustic neuroma: an international case-control
study. Int J Cancer, 120(1), 103−10.
Schoemaker MJ, Swerdlow AJ, Hepworth SJ, McKinney PA,
van Tongeren M and Muir KR (2006). History of allergies and
risk of glioma in adults. Int J Cancer, 119(9), 2165−72.
Schoemaker MJ, Swerdlow AJ, Hepworth SJ,
van Tongeren M, Muir KR and McKinney PA (2007).
History of allergic disease and risk of meningioma.
Am J Epidemiol, 165(5), 477−85.
Schwartzbaum JA, Ahlbom A, Lönn S, Malmer B,
Wigertz A, Auvinen A, Brookes AJ, Collatz Christensen H,
Henriksson R, Johansen C, Salminen T, Schoemaker MJ,
Swerdlow AJ, Debinski W and Feychting M (2007).
An international case-control study of interleukin4R{alpha}, interleukin-13, and cyclooxygenase-2
polymorphisms and glioblastoma risk. Cancer Epidemiol
Schwartzbaum JA, Ahlbom A, Lönn S, Warholm M,
Rannug A, Auvinen A, Christensen HC, Henriksson R,
Johansen C, Lindholm C, Malmer B, Salminen T,
Schoemaker MJ, Swerdlow AJ and Feychting M (2007).
An international case-control study of glutathione
transferase and functionally related polymorphisms and
risk of primary adult brain tumors. Cancer Epidemiol
Biomarkers Prev, 16, 559−65.
Wigertz A, Lönn S, Schwartzbaum J, Hall P Auvinen A,
,
Christensen HC, Johansen C, Klaeboe L, Salminen T,
Schoemaker MJ, Swerdlow AJ, Tynes T and Feychting M
(2007). Allergic conditions and brain tumor risk. Am J
Epidemiol, 166(8), 941−50.
Wigertz A, Lönn S, Hall P Auvinen A, Christensen HC,
,
Johansen C, Klaeboe L, Salminen T, Schoemaker MJ,
Swerdlow AJ, Tynes T and Feychting M (2008).
Reproductive factors and risk of meningioma and glioma.
Cancer Epidemiol Biomarkers Prev, 17(10), 2663−70.

Appendix D
Membership of the
In order to ensure the independence of the MTHR Programme, an independent Programme Management Committee (PMC) was
set up to decide on research priorities, select projects and manage the research. Sir William Stewart originally chaired the
PMC, which included some members of the Independent Expert Group on Mobile Phones along with additional experts, who
together provided a broad range of expertise. There was also strong international representation, with overseas members and
a representative of the World Health Organization. In November 2002 Sir William was succeeded by Professor Lawrie Challis,
while in January 2008 Professor Challis was succeeded by Professor David Coggon.
New members have also been appointed from time to time to maintain the expertise needed for effective management of
the programme.

Professor David Coggon OBE
Member 2008, Chairman 2008−2012
David Coggon studied mathematics and medicine at the universities of Cambridge and Oxford. He is
currently Professor of Occupational and Environmental Medicine at Southampton University where
he works in the Medical Research Council Lifecourse Epidemiology Unit. He has been engaged in
epidemiological research for more than 30 years, focusing mainly on occupational and environmental
causes of disease. Special interests include the relation of musculoskeletal disorders to physical
activities in the workplace and psychosocial determinants, and the health effects of chemical
pollutants. He is also a consultant occupational physician and holds an honorary contract with
University Hospital Southampton NHS Foundation Trust. He is a Fellow of the Academy of Medical
Sciences and Chairman of the Committee on Toxicity of Chemicals in Food, Consumer Products and
the Environment. In the past, he chaired the Depleted Uranium Oversight Board and the Advisory
Committee on Pesticides, and was a member of the Expert Panel on Air Quality Standards, the
Industrial Injuries Advisory Council, the Independent Expert Group on Mobile Phones and the Advisory
Group on Non-ionising Radiation. He was awarded the OBE in 2002.

Professor Lawrie Challis OBE
Vice-chairman 2001−2002, Chairman 2002−2008, Member 2008−2012
Lawrence Challis is Emeritus Professor of Physics at the University of Nottingham. His university
education and the first years of his academic career were at the University of Oxford (1951−1959); he
then moved to the University of Nottingham. He was appointed to an established chair in 1971, was
Pro-Vice-Chancellor before his retirement in 1998 and then held a Leverhulme Emeritus Fellowship. His
research interests were on the properties of low dimensional semiconductors. In 1994 he was awarded
the Holweck Medal and Prize for his research by the Institute of Physics/French Physical Society. In
1996 he was awarded the OBE for services to scientific research. He has chaired the Royal Society
Grant Board for Mathematics and Physics, the Physics Committee of the Science and Engineering
Research Council, the Solid State Division of the Institute of Physics and the European Commission
Evaluation Panel for Access to Research Infrastructures. He was Vice-chairman of the Independent
Expert Group on Mobile Phones and a member of the Advisory Group on Non-ionising Radiation and of
the Health and Safety Management Committee of TETRA.

43


Professor Sir William Stewart FRS FRSE
Chairman 2001−2002
Sir William Stewart is a former Chief Scientific Adviser to the Prime Minister and to the Government
and the first Head of the UK Government’s Office of Science and Technology. He is a biologist by
training and Emeritus Professor of Biology at the University of Dundee. He has served as President
of the Royal Society of Edinburgh, as Vice-President of the Royal Society of London, Chairman of
the Health Protection Agency, Tayside University Hospitals NHS Trust, the Microbiological Research
Authority, the National Radiological Protection Board and Cyclacel plc, and as Chief Executive of the
Agricultural and Food Research Council. He has served on various advisory committees including the
Royal Commission on Environmental Pollution and the Natural Environment Research Council.

Professor Les Barclay OBE FREng
Member 2001−2002, Vice-chairman 2003−2012
Professor Les Barclay was Deputy Director at the Radiocommunications Agency, responsible for
research and radio technology. He is now a consultant in radio regulation, spectrum management
and radio propagation, and is a visiting professor at the universities of Bradford, Lancaster and
Surrey. He has been chairman of the study group on radiowave propagation within the International
Telecommunication Union and chairman of the Scientific Committee on Telecommunications within
the International Union of Radio Science. He is a Fellow of the Royal Academy of Engineering and
is currently a member of the Electronics and Communications Divisional Board of the Institution of
Electrical Engineers. He has been awarded the OBE and the Polar Medal.

Professor Colin Blakemore FRS
Member 2001−2003, Vice-chairman 2003
Colin Blakemore studied medical sciences at the University of Cambridge and completed his PhD at the
University of California, Berkeley, in 1968. He taught at the University of Cambridge for 11 years and
in 1979 took up the Chair of Physiology at the University of Oxford, where he was also Director of the
Oxford Centre for Cognitive Neuroscience. He has worked as a visiting professor at the Massachusetts
Institute of Technology, New York University, the University of California and the Salk Institute, and
also in Japan, Switzerland, Italy, France, the Czech Republic and China. He is a Fellow of the Royal
Society and the Academy of Medical Sciences and is a member of several foreign academies, including
the Chinese Academy of Engineering. He holds ten honorary doctorates and is an Honorary Fellow of
the Royal College of Physicians, the Royal Society of Medicine and the Society of Biology. He has been
President of the British Neuroscience Association, the Biosciences Federation (now the Society of
Biology), the Physiological Society and the British Association for the Advancement of Science (now the
British Science Association).
His research has been concerned with many aspects of vision and the early development of the brain.
His awards include the international Alcon Prize for vision research, the Ralph Gerard Prize of the
Society for Neuroscience, the Friendship Award from the People’s Republic of China and both the
Michael Faraday Award and the David Ferrier Award from the Royal Society. He is a former member of
the Advisory Group on Non-ionising Radiation and was a member of the Independent Expert Group on
Mobile Phones. Colin retired from the PMC in 2003, following his appointment as Chief Executive of
the Medical Research Council. He is now Emeritus Professor of Neuroscience at Oxford and Professor of
Neuroscience and Philosophy at the School of Advanced Study, University of London.

44

Appendix D Membership of the MTHR Programme Management Committee

Professor Dame Glynis M Breakwell DBE DL
Member 2002−2007
Professor Dame Glynis Breakwell took her PhD from the University of Bristol and her DSc from the
University of Oxford. She was Prize Fellow at Nuffield College, Oxford, before moving to the University
of Surrey where she became Professor of Psychology in 1991 and Pro-Vice-Chancellor of the University
in 1995. In September 2001 she became Vice-Chancellor of the University of Bath. In 2012 she was
made a DBE for her contribution to higher education. Her research on identity process theory and
on the psychology of risk management has led to many awards and recognition from academic and
professional bodies (including being made an Honorary Fellow of the British Psychological Society
and an Academician of the Academy of Social Sciences). She has authored or co-authored more than
400 refereed journal articles and conference papers, authored or co-authored 13 books, and edited or
co-edited a further 15.
Dame Glynis Is a member of the Council of the Economic and Social Research Council (and chairs
its Research Committee). She is a director of Universities UK, of the Student Loans Company and of
the Universities Superannuation Scheme. She is a director of the West of England Local Economic
Partnership and Deputy Lieutenant of Somerset. She is chair of the Daphne Jackson Trust and a
member of the RCUK Panel on public engagement in research. She is a member of the World Cultural
Council prize committee.

Professor Clair Chilvers BSc(Econ) MSc DSc FFPHM
Member 2002−2005
Professor Clair Chilvers is Head of Research and Development in the Midlands and East of England
Directorate of Health and Social Care. She was appointed Regional Director of Research and
Development at NHS Executive Trent in October 1999. Nationally, she is Director of the Mental Health
Research and Development Portfolio and the National Forensic Mental Health R&D Programme. She is
also a member of the National Mental Health Task Force, taking forward objectives of the NHS Plan.
Previously she was Professor of Epidemiology at the University of Nottingham and from 1996 was Dean
of the Graduate School. She was a member of the Department of Health Committee on Carcinogenicity
of Food, Consumer Products, and the Environment from 1993 to 2000 and a member of the Royal
Commission on Environmental Pollution from 1994 to 1998.

Professor Paul Elliott MA MB BS MSc PhD FRCP FFPHM FMedSci
Member 2001−2008
Paul Elliott trained in mathematics and medical sciences at the University of Cambridge, and
clinical medicine at University College Hospital Medical School, London. He worked as a medical
epidemiologist at the London School of Hygiene and Tropical Medicine for 13 years and was Head of the
Environmental Epidemiology Unit, from 1990 to 1995. He is currently Professor of Epidemiology and
Public Health Medicine in the School of Public Health at Imperial College London and is Director of the
MRC-PHE Centre for Environment and Health which incorporates the Small Area Health Statistics Unit
(SAHSU). Professor Elliott is principal investigator of the AIRWAVE health monitoring study in UK police
officers which is studying the possible long-term health effects from the use of the TETRA airwave
communication system. He also leads the UK arm of the international COSMOS study on mobile phone
use and health. He wrote the chapter on adult cancers for the WHO Environmental Health Criteria
No. 238 on Extremely Low Frequency Fields (2007). He has been a member of a number of high-level
scientific and government advisory boards including Defra’s Science Advisory Council (2006−2009),
representative for the Academy of Medical Sciences on the National Information and Governance Board
(2011−2013) and the Government Chief Scientist’s Blackett Review on Biodetection (2012−2013). He is
a lead investigator for UK Biobank and a founding member of its Steering Committee. He chaired the
Phenotype Enhancements Committee which made recommendations for biochemical, occupational and
environmental enhancements to the UK Biobank resource.

45


Dr Tony Fletcher
Member 2008−2012
Dr Tony Fletcher is Senior Lecturer in Environmental Epidemiology at the London School of Hygiene
and Tropical Medicine having been there since 1992, and Adjunct Research Professor in Environmental
Health in the School of Public Health, Boston University, Massachusetts, USA, since 2007. He has
previously been employed at the International Agency for Research on Cancer (IARC), the MRC
Environmental Epidemiology Unit in Southampton, and Birmingham and Aston universities.
He has worked for over 30 years in occupational and environmental epidemiology and risk assessment,
and has experience of studies of cancer, endocrine disruptors and gene-environment interaction.
Major studies he has led include two multicountry environmental epidemiology projects funded by
the European Union: ‘ASHRAM’ on cancer risks in relation to water contaminated by arsenic in Central
Europe and ‘PATY’ on the respiratory effects of air pollution in 12 countries in Europe, North America
and Russia. More recently he has been running a study on health effects of drinking water exposure to
perfluorooctanoic acid (PFOA or C8), in West Virginia and Ohio, USA.

Dr Simon Gerrard
Member 2001−2003
During his PMC membership Dr Simon Gerrard was Deputy Director of the Centre for Environmental Risk
at the University of East Anglia. His particular area of research is in risk communication. Dr Gerrard
has been an expert adviser to the WHO and FAO on risk perception and communication matters and
was the first Director of the WHO-inspired European Risk Communication Network funded in part by
the UK Electricity Association. He was the project leader for the risk communication and trust element
of the Programme on Understanding Risk, funded by the Leverhulme Trust. His research within that
programme focused on three main case study areas: waste disposal (including radioactive wastes),
mobile phones and climate change. The key themes within these areas were the communication of
uncertainty and its impact on trust; the evaluation of risk communication initiatives; and the role of
risk communication within the strategic development of open decision-making. Dr Gerrard was involved
in the UK element of the HERMES research project which is seeking to develop a European perspective
on the management of base stations. Since 2003 Dr Gerrard has been working in low carbon innovation
within the Adapt Group at the University of East Anglia.

Professor Ted Grant
Member 2001−2010
Professor Grant studied the interaction of microwaves with biological material for 50 years. He
served in the physics departments of three London teaching hospitals before joining Queen Elizabeth
College, and subsequently King’s College London, where he was Head of Department from 1992
to 1994. He retired in 1996 and joined MCL as Principal Scientific Consultant and Non-executive
Director. He was a member of the Board of NRPB from 1989 to 1997 and was a member of the Advisory
Group on Non-ionising Radiation for 11 years. Professor Grant was also Chairman of the BSI GEL 106
Committee concerned with the development of international standards to assess human exposure to
electromagnetic fields. Professor Grant retired from the MTHR Programme Management Committee in
January 2010.

46


Professor Patrick Haggard
Member 2003−2012
Patrick Haggard is a researcher in cognitive neuroscience at University College London. He trained at
the MRC Applied Psychology Unit in Cambridge, and then at the University Laboratory of Physiology in
Oxford. He has worked at UCL since 1995, using behavioural and physiological methods to study sensory
and motor functions of the brain.

Professor Kjell Hansson Mild
Member 2001−2012
Professor Kjell Hansson Mild worked at the Swedish National Institute for Working Life and at Örebro
University, where he conducted research on the bioeffects of electromagnetic fields. He has worked
on the bioeffects of electromagnetic fields since 1976. After the closure of NIWL he transferred to
Umeå University, Department of Radiation Sciences, in 2007. He has a background in physics and
theoretical physics, and he presented his thesis in 1974 on problems on cell membrane permeability
and the state of water in the cytoplasm. In the last 15 years he has carried out research on mobile
phone use and brain tumours. Presently he is also working on the effects of occupational exposure
from the MRI machines.
Professor Hansson Mild has published over 300 articles and 200 conference abstracts. He was the first
person from Europe to serve on the Board of the Bioelectromagnetics Society and was President from
1995 to 1996. He has also served as associate editor for the journal Bioelectromagnetics during the
years 1988 to 1996.

Professor Niels Kuster
Member 2001−2012
Niels Kuster was born in Olten, Switzerland, in June 1957. He received a master’s degree in electrical
engineering and a doctoral degree in technical science from the Swiss Federal Institute of Technology
(ETH) in Zurich, Switzerland. In 1993, he was elected as Professor at the Department of Electrical
Engineering of the Swiss Federal Institute of Technology (ETH) in Zurich. In 1999 he was appointed as
Director of the Foundation and Laboratories for Research on Information Technologies in Society (IT’IS),
Switzerland (www.itis.ethz.ch). In 1992 he was Invited Professor at the Electromagnetics Laboratory of
Motorola Inc in Florida, USA, and in 1998 at the Metropolitan University of Tokyo, Japan.
His research interest is currently focused on the area of reliable and safe on/in-body wireless
communications and related topics. This includes:
a measurement technology
b computational electrodymanics for evaluation of close near fields in complex environments (eg
handheld or body-mounted transceivers and living-work environments)
c exposure assessments
d development of exposure setups and quality control for bioexperiments evaluating interaction
mechanisms and therapeutic effects as well as potential health risks
e wireless life support systems
Professor Kuster is the author of over 150 publications (books, journals and proceedings) mainly on
measurement techniques, computational electromagnetics, dosimetry and exposure assessments,
as well as on bioexperiments. He is a member of several standardisation bodies and has acted as a
consultant for several government agencies around the globe on the issue of the safety of mobile
communications. He also serves on the boards of various scientific commissions, societies and journals.

47


Dr Alastair McKinlay
Member 2001−2008
Alastair McKinlay was Head of the Physical Dosimetry Department in the Radiation Protection Division
of the Health Protection Agency until his retirement in 2009.
In 1996 he chaired a European Union Expert Group on Mobile Telephony and Human Health whose
report set out a comprehensive European research agenda. He is a former Chairman of the
International Commission on Non-Ionizing Radiation Protection (ICNIRP). He has been active in the
International Commission on Illumination (CIE) for many years and is a past Chairman of the United
Kingdom National Committee. He is a founder member and a past president of the European Society
for Skin Cancer Prevention (EUROSKIN). He has served as a member of several WHO risk assessment
groups dealing with non-ionising radiations and was formerly a member of the WHO International EMF
and INTERSUN Programmes Advisory Committees.

Professor Jim Metcalfe
Member 2001−2012
Jim Metcalfe has been Professor of Mammalian Cell Biochemistry in the Department of Biochemistry,
University of Cambridge, since 1996 and was Sir William Dunn Reader in Biochemistry in the same
department from 1975. From 2001 to 2006 he was Deputy Head of Department and Director of
Research and Development and was seconded part-time to the Cancer Research Campaign as Chairman
of the Scientific Committee from 1995 to 2000. He is currently chairman of the scientific advisory
committee for the EMF Biological Research Trust which has the remit of evaluating any biological
effects of powerline frequency electromagnetic fields that may affect human health. His current
research interests are in laboratory and translational clinical research studies on the role of cytokines,
particularly the transforming growth factor beta family, in the aetiology of metastatic tumours and
coronary artery disease.

Dr Mike Repacholi
Member 2001−2007
Michael Repacholi is a graduate of the University of Western Australia (BSc, physics), London University
(MSc, radiation biology) and Ottawa University (PhD, biology). He is co-author of over 220 scientific
publications and is currently a visiting professor in the Department of Information Engineering,
Electronics and Telecommunications (DIET), University of Rome ‘La Sapienza’.
He initiated the International EMF Project at the World Health Organization, Geneva, in 1995 and was
Coordinator of the WHO Radiation and Health Unit until retirement in June 2006. He has participated
in 14 WHO task groups on various aspects of non-ionising radiation, was a founding member and
chaired the International Non-Ionizing Radiation Committee of the International Radiation Protection
Association (INIRC/IRPA) and was the first Chairman of the International Commission on Non-Ionizing
Radiation Protection at its inception in 1992. In May 1996 he was elected Chairman Emeritus of ICNIRP
.
He was awarded honorary doctorates in 2002 from the Minsk Medical University for his contribution
to Belarus on the Chernobyl accident and from San Marco University in 2011 for his contribution to
Peru on non-ionising radiation protection. Prior to this he was awarded the WG Morgan Lectureship for
‘Outstanding international contributions to the radiation field’ June 1993 by the Health Physics Society,
honorary life membership in the Italian Radiation Protection Society in 1994, the Russian Academy of
Medical Science’s Speransky Gold Medal for ‘Great contributions to protection against ionizing and nonionizing radiation’ and the NW Timofeef-Ressovsky Medal for ‘Valuable contribution to research on the
effects of non-ionizing and ionizing radiation on human health and the environment’ in 2004.
Dr Repacholi is Fellow and Past President of the Australian Radiation Protection Society, and the
Australian College of Physical Sciences and Engineering in Medicine.

48


Professor Michael Rugg FRSE
Member 2001−2003, Member 2005−2012
Michael Rugg obtained his PhD in 1979. Following a postdoctoral year at the University of York, he
was appointed to a lectureship in psychology at the University of St Andrews, where he became
Professor of Psychology and Head of School in 1992. In 1998 he moved to the Institute of Cognitive
Neuroscience, University College London, as Professor of Cognitive Neuroscience and Wellcome
Trust Principal Research Fellow. His principal research interests are the cognitive and neurological
basis of human memory and the non-invasive investigation of human brain function through the use
of electroencephalography and functional neuroimaging. During 1998 and 1999 he served on the
Department of Health Working Group on Organophosphates.

Dr Zenon Sienkiewicz
Member 2001−2012
Zenon Sienkiewicz obtained his PhD from Queen Mary College, University of London, for research into
the neurobiology of memory. Following postdoctoral work at the University of Oxford, he joined the
National Radiological Protection Board (whose functions are now carried out by Public Health England)
in 1985. His research interests include the neurophysiological and behavioural effects of magnetic
fields and radiofrequency radiation. He has written a wide variety of scientific papers, reviews and
articles on these topics. He is a member of the International Commission on Non-Ionizing Radiation
Protection and a member of a number of other groups and committees concerned with the effects of
non-ionising radiation.

Dr Emilie van Deventer
Member 2006−2012
Emilie van Deventer obtained her PhD from the University of Michigan, USA, in electrical engineering.
She became a professor at the University of Toronto, Department of Electrical and Computer
Engineering, in 1992 where she was awarded a Junior Chair in Electromagnetics. She joined the
World Health Organization in 2000, where she has been the team leader of the Radiation Programme
since 2006. Her activities focus on the development of scientific documents, policy frameworks and
information brochures relating to public health protection from non-ionising radiation. She is a WHO
designated observer on several groups and committees concerned with the effects of ionising radiation
(ICRP Committee 4) and non-ionising radiation (Swedish Radiation Safety Authority).

49


Secretariat
Department of Health: Policy

Scientific Co-ordination (NRPB/HPA/PHE)

Mr Stuart Conney (2010−2012)

Dr Nigel Cridland (2001−2012)

Ms Charlotte Creedon (2005−2009)

Dr Ilana Al-irimi (2001−2003)

Mr George Hooker (2001−2009)

Mrs Mary Allan (2003−2005)

Dr Pat Keep (2007−2012)

Mr Raj Bunger (2005−2006)

Ms Kim Stonell (2004−2012) (HPA 2005 onwards)

Mrs Wendy Clarke (2010−2012)

Ms Monika Temple (2001−2004)

Ms Jo Lake (2001−2010)

Ms Angela Thompson

Mr Steve Pritchard (2006−2012)

Dr Hilary Walker (2001−2008)

Mr David Stevens (2010−2012)

Department of Health: Research and Development

Mr Mark Vaughan (2007−2008)

Ms Monika Temple (2010−2011)
Dr Ursula Wells (2011−2012)

Department of Trade and Industry
Mr Graham Worsley (2001 – 2007)

50

Dr Toby Whillock (2008−2010)

MTHR Scientific Co-ordination Team
www.mthr.org.uk
c/o Centre for Radiation, Chemical and Environmental Hazards
Public Health England
Chilton, Didcot, Oxfordshire OX11 0RQ
ISBN 978-0-85951-754-6
£20.00
© Crown copyright 2013

Mthr report 2012

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Mthr report 2012