Electromagnetic hypersensitivity
From Wikipedia, the free encyclopedia
Idiopathic environmental intolerance attributed to electromagnetic fields (
IEI-EMF) is a descriptive term for symptoms purportedly caused by exposure to
electromagnetic fields.
[1] Other terms for IEI-EMF include
electromagnetic hypersensitivity (
EHS),
electrohypersensitivity,
electro-sensitivity, and
electrical sensitivity (
ES).
Although the thermal effects of electromagnetic fields on the body
are established, self-described sufferers of electromagnetic
hypersensitivity report responding to
non-ionizing electromagnetic fields (or electromagnetic radiation) at intensities well below the limits permitted by international
radiation safety standards.
The reported symptoms of EHS include headache, fatigue, stress, sleep
disturbances, skin symptoms like prickling, burning sensations and
rashes, pain and ache in muscles and many other health problems.
Whatever their cause, EHS symptoms are a real and sometimes disabling
problem for the affected person.
[2]
The majority of
provocation trials
to date have found that self-described sufferers of electromagnetic
hypersensitivity are unable to distinguish between exposure to real and
fake electromagnetic fields,
[3][4]
and it is not recognized as a medical condition by the medical or
scientific communities. Since a systematic review in 2005 showing no
convincing scientific evidence for it being caused by electromagnetic
fields,
[3]
several double-blind experiments have been published, each of which has
suggested that people who report electromagnetic hypersensitivity are
unable to detect the presence of electromagnetic fields and are as
likely to report ill health following a sham exposure, as they are
following exposure to genuine electromagnetic fields, suggesting the
cause to be the
nocebo effect.
[5][6][7]
Symptoms and severity
A 2001 survey found that people related their symptoms most frequently to
mobile phone base stations (74%), followed by
mobile phones (36%),
cordless phones (29%) and
power lines (27%). The survey was not designed to find any causal connection between
electromagnetic field exposure and ill health.
[8]
A report from the
UK Health Protection Agency
said that self-described "electrical sensitivity" sufferers have
symptoms that can be grouped into two broad categories: facial skin
symptoms and more general,
non-specific symptoms
across a range of body systems. The facial skin symptoms and their
attribution to visual display units was mostly a Nordic phenomenon. The
report pointed out that it did not "imply the acceptance of a causal
relationship between symptoms and attributed exposure".
[9]
Recently a smaller group of people in Europe as a whole and in the
USA have reported general and severe symptoms such as headache, fatigue,
tinnitus, dizziness, memory deficits, irregular heart beat, and whole-body skin symptoms.
[10] A 2005 Health Protection Agency report noted the overlap in many sufferers with other syndromes known as
symptom-based conditions, FSS (
functional somatic syndromes) and IEI (
idiopathic environmental intolerance).
[9] Levitt proposed ties between electromagnetic fields and some of these 20th-century maladies, including
chronic fatigue syndrome,
Gulf War syndrome, and
autism.
[11]
Figures from Carlsson
et al.[12]
show that 1.9% of people report much annoyance from visual displays and
fluorescent lighting. 2.4% report much or some annoyance with both any
electrical factor and also chemicals or smells. A 1991 study by William
J. Rea concluded that there is "strong evidence that electromagnetic
field sensitivity exists".
[13]
Those reporting electromagnetic hypersensitivity will usually describe different levels of susceptibility to
electric fields,
magnetic fields and various frequencies of
electromagnetic waves (including fluorescent and low-energy lights, and
microwaves from
mobile,
cordless/portable phones), and
Wifi with no consistency in the severity of symptoms between sufferers.
[14]
Other surveys of electromagnetic hypersensitivity sufferers have not
been able to find any consistent pattern to these symptoms.
[8][15] Instead symptoms reflecting almost every part of the body have been attributed to electromagnetic field exposure.
A minority of people who report electromagnetic hypersensitivity
claim to be severely affected by it. For instance, one survey has
estimated that approximately 10% of electromagnetic hypersensitivity
sufferers in Sweden were on sick leave or have taken early retirement or
a disability pension, compared to 5% of the general population,
[15]
while a second survey has reported that of 3046 people who experienced
'annoyance' from electrical equipment, 340 (11%) reported 'much'
annoyance.
[12]
For those who report being severely affected, their symptoms can have a
significant impact on their quality of life; with sufferers reporting
physical, mental and social impairment and psychological distress.
[8]
Prevalence
The prevalence of claimed electromagnetic hypersensitivity has been
estimated as being between a few cases per million to 5% of the
population depending on the location and definition of the condition.
In 2002, a
questionnaire
survey of 2,072 people in California found that the prevalence of
self-reported electromagnetic hypersensitivity within the sample group
was 3% (95% CI 2.8–3.68%), with electromagnetic hypersensitivity being
defined as "being allergic or very sensitive to getting near electrical
appliances, computers, or power lines" (response rate 58.3%).
[16]
A similar questionnaire survey from the same year in Stockholm County
(Sweden), found a 1.5% prevalence of self-reported electromagnetic
hypersensitivity within the sample group, with electromagnetic
hypersensitivity being defined as "hypersensitivity or allergy to
electric or magnetic fields" (response rate 73%).
[15]
A 2004 survey in Switzerland found a 5% prevalence of claimed electromagnetic hypersensitivity in the sample group of 2,048.
[17]
In 2007, a UK survey aimed at a randomly selected group of 20,000
people found a prevalence of 4% for symptoms self-attributed to
electromagnetic exposure.
[18]
A group of scientists also attempted to estimate the number of people
reporting "subjective symptoms" from electromagnetic fields for the
European Commission.
[19]
In the words of a HPA review, they concluded that "the differences in
prevalence were at least partly due to the differences in available
information and media attention around electromagnetic hypersensitivity
that exist in different countries. Similar views have been expressed by
other commentators."
[9]
Scientific evidence and etiology
World Health Organization
Following a study conducted in 2005, the
World Health Organization (WHO) concluded that:
EHS is characterized by a variety of non-specific symptoms that
differ from individual to individual. The symptoms are certainly real
and can vary widely in their severity. Whatever its cause, EHS can be a
disabling problem for the affected individual. EHS has no clear
diagnostic criteria and there is no scientific basis to link EHS
symptoms to EMF exposure. Further, EHS is not a medical diagnosis, nor
is it clear that it represents a single medical problem.[1]
Studies
Although individuals who report electromagnetic hypersensitivity
believe that electromagnetic fields from common electrical devices
trigger or exacerbate their symptoms, it has not been established that
these fields play any role in the cause of these symptoms.
[20] Exposures are to
intensity
levels below those generally accepted to cause physiological effects,
and the diverse physiological effects reported are not what would be
expected from high intensity electromagnetic fields.
[citation needed]
Sufferers and their support groups are convinced of a causal
relationship with electromagnetic fields, but presently the scientific
literature does not support such a link.
[20]
Some professionals consider electromagnetic hypersensitivity to be a
physical condition with an unclear cause, while others suggest that some
aspects may be psychological.
[1][3] Reviews have suggested that psychological mechanisms may play a role in causing or exacerbating EHS symptoms.
[21]
Research has also shown neurophysiological differences between
sensitive individuals and controls. This may reflect either a
psychophysiological stress response to participating in the study or a
more general imbalance in autonomic nervous system regulation.
[1][22][23][24][25]
In 2005, a
systematic review
looked at the results of 31 experiments testing the role of
electromagnetic fields in causing ES. Each of these experiments exposed
people who reported electromagnetic hypersensitivity to genuine and sham
electromagnetic fields under single- or
double-blind conditions.
[3] The review concluded that:
The symptoms described by 'electromagnetic hypersensitivity'
sufferers can be severe and are sometimes disabling. However, it has
proved difficult to show under blind conditions that exposure to
electromagnetic fields can trigger these symptoms. This suggests that
'electromagnetic hypersensitivity' is unrelated to the presence of
electromagnetic fields, although more research into this phenomenon is
required.
Seven studies were found which did report an association, while 24
could not find any association with electromagnetic fields. However, of
the seven positive studies, two could not be replicated even by the
original authors, three had serious methodological shortcomings, and the
final two presented contradictory results. Since then, several more
double-blind experiments have been published, each of which has
suggested that people who report electromagnetic hypersensitivity are
unable to detect the presence of electromagnetic fields and are as
likely to report ill health following a sham exposure, as they are
following exposure to genuine electromagnetic fields.
[5][6][7]
One of the studies which Rubin et al. reviewed, known as the Essex
study, received some criticism for its methodology and analysis, and the
authors responded in full to these initial criticisms.
[26]
The authors noted that their study says nothing about the long-term
effects of exposure to electromagnetic fields, but those affected
generally claimed to respond to the fields within a few minutes.
In January, 2010 Rubin et al. published a follow up to their original
review which included 15 experiments done since the last original
review, bringing the totals up to 46 double-blind experiments and 1175
individuals with claimed hypersensitivity. The study confirmed the
results of the original, claiming "no robust evidence could be found" to
support the hypothesis that electromagnetic exposure causes EHS. The
review also found that the studies included did support the role of the
nocebo effect in triggering acute symptoms in those with EHS.
[27]
In 2008, another systematic review reached the same conclusion as Rubin et al.
[4]
A 2005 report by the UK
Health Protection Agency concluded that electromagnetic hypersensitivity needs to be considered in ways other than its
etiology;
that is, the suffering is real, even if the underlying cause is not
thought to be related to electromagnetic fields. They also wrote that
considering only whether electromagnetic radiation was a causative
factor was not meeting the needs of sufferers, although continued
research on etiology was essential.
[9]
In 2002, some controversy over the causal relationship was
demonstrated by the Freiburger Appeal, a petition originated by the
German environmental medical lobby group
IGUMED,
which stated that "we can see a clear temporal and spatial correlation
between the appearance of [certain] disease and exposure to pulsed
high-frequency microwave radiation", and demanding radical restrictions
on mobile phone use.
[28]
To address some of these concerns, and others, Hocking advised in a
2006 WHO proceedings that the test type and duration should be tailored
to the individual, and that washout times are needed to prevent a
carry-over effect of previous exposure.
[29] However, in 2005 the
World Health Organization
concluded that there is no known scientific basis for the belief that
electromagnetic hypersensitivity is caused by exposure to an
electromagnetic field.
[1]
Diagnosis
Electromagnetic hypersensitivity is not currently an accepted
diagnosis. At present there are no accepted research criteria other than
'self-reported symptoms', and for clinicians there is no case
definition or clinical practice guideline. There is no specific test
that can identify sufferers, as symptoms other than skin disorders tend
to be subjective or non-specific. It is important firstly to exclude all
other possible causes of the symptoms. Researchers and the WHO have
stressed the need for a careful investigation. For some, complaints of
electromagnetic hypersensitivity may mask organic or psychiatric illness
and requires both a thorough medical evaluation to identify and treat
any specific conditions that may be responsible for the symptoms, and a
psychological evaluation to identify alternative
psychiatric/psychological conditions that may be responsible or
contribute to the symptoms.
[1][30]
A WHO factsheet also recommends an assessment of the workplace and
home for factors that might contribute to the presented symptoms. These
could include indoor air pollution, excessive noise, poor lighting
(flickering light) or ergonomic factors. They also point out that
"[s]ome studies suggest that certain physiological responses of
[electromagnetic hypersensitivity] individuals tend to be outside the
normal range. In particular, hyper reactivity in the central nervous
system and imbalance in the autonomic nervous system need to be followed
up in clinical investigations and the results for the individuals taken
as input for possible treatment."
[1]
Possible treatment and symptom alleviation
For individuals reporting electromagnetic hypersensitivity with long
lasting symptoms and severe handicaps, treatment therapy should be
directed principally at reducing symptoms and functional handicaps. This
should be done in close co-operation with a qualified medical
specialist to address the symptoms and a hygienist (to identify and, if
necessary, control factors in the environment that have adverse health
effects of relevance to the patient).
[1]
Those who feel they are sensitive to electromagnetic fields generally
try to reduce their exposure to electromagnetic sources as much as is
practical. Complete avoidance of electromagnetic fields presents major
practical difficulties in modern society. Methods often employed by
sufferers include: avoiding sources of exposure; disconnecting or
removing electrical devices; shielding or screening of self or
residence; medication; and
complementary and alternative therapy.
[8]
The UK Health Protection Agency reviewed treatments for
electromagnetic hypersensitivity, and success was reported with
"neutralizing chemical dilution, antioxidant treatment, Cognitive
Behavioural Therapy, Acupuncture and Shiatsu".
[9] It was noted that:
The studies reviewed suffer from a combination of the small numbers
of subjects included and the potential variation both within and between
study populations. Little information is given as to the attributed
exposures of the subjects. These factors limit their general
applicability outside the immediate study group. For those studies where
detail was available, only two were placebo controlled [Acupunture and
nutrition intervention].
It was also noted in the review that success may have more to do with
offering a caring environment as opposed to a specific treatment.
A 2006 systematic review identified nine clinical trials testing different treatments for ES:[31] four studies tested cognitive behavioural therapy,
two tested visual display unit filters, one tested a device emitting
'shielding' electromagnetic fields, one tested acupuncture, and one
tested daily intake of tablets containing vitamin C, vitamin E, and
selenium. The authors of the review concluded that:
The evidence base concerning treatment options for electromagnetic
hypersensitivity is limited and more research is needed before any
definitive clinical recommendations can be made. However, the best
evidence currently available suggests that cognitive behavioural therapy
is effective for patients who report being hypersensitive to weak
electromagnetic fields.
Some Americans with the condition have moved to the United States National Radio Quiet Zone where wireless is restricted.[32][33]
Conferences
In 2004 the
World Health Organization (WHO) conducted a workshop on electromagnetic hypersensitivity.
[34]
The aim of the conference was to review the current state of knowledge
and opinions of the conference participants and propose ways forward on
this issue. The meeting was conducted by the WHO International EMF
Project as part of the scientific review process to determine biological
and health effects from exposure to EMF. The purpose of these workshops
is to bring together expert scientists so that established health
effects and gaps in knowledge requiring further research can be
identified. EHS has been a particularly contentious issue for a number
of years.
See also
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