Betreff: Google Alert - Electrical fields
Von: Martin Weatherall
Datum: Thu, 26 Jul 2007 23:14:49 -0400
The link below is to the British Daily Telegraph newspaper. Unfortunately the Telegraph have made a serious error with their title, because that is not what the story is about and it simply, is not true.
The story is about electro hypersensitivity and testing at Essex University. EHS volunteers failed to identify exposure to cell phone emissions, but there are good reasons why this happened.
If you look at the readers comments below the newspaper article you will find at least five people who have given good reasons why the testing failed. You will also find ignorant comments from stupid people who either do not know what they are talking about or they are deliberately trying to confuse the true situation.
The e-mail attachment above - Essex EHS Study.eml, will show you very good reasons why the testing was a failure.
The other document that is attached is about the EHS testing that is done at a clinic in Wiesenthal, Germany. I have no reports as to the effectiveness of the clinic's testing procedure.
Mobile phone masts
'do not damage health'
Telegraph.co.uk - United Kingdom
However campaigners and individuals who claim sources of electrical fields including masts can cause a syndrome called electromagnetic hypersensitivity (EH) ...
See all stories on this topic
Betreff: Essex EHS Study
Von: Sarah Dacre
Datum: Wed, 25 Jul 2007 09:14:50 EDT
Essex EHS Study Published today and broadcast on the BBC 1 One o'clock News today:
scroll down about 15 minutes.
and for a Powerwatch synopsis:
The latest double blind provocation study by Essex University has found that
there is no significant difference between the subjective (self-assessed
symptoms) and objective (measured symptoms - e.g heart rate) responses
between sensitive and control participants, regardless of the system to
which they were exposed.
Firstly, of the original 56 selected to take part in the study, 12 withdrew
before the double-blind exposures, of which some withdrew very specifically
because of the severity of symptoms from the open exposure. To lose 20% of
the "sensitive" category in this way may well remove the most sensitive, or
"truly" sensitive participants in the study.
Secondly, when addressing a subject such as this, where there is so much
general public concern, there is bound to be a high level of nocebo effect
amongst those that believe they may have a problem. This would give rise to
a much higher proportion of self-assessed sensitive participants that were
not in fact sensitive, and this would have the effect of "hiding" those that
were actually responding to the provocations. This is a potentially very
serious confounder that has simply not been addressed in this study.
Thirdly, anecdotal reports of sensitivity (useful when deciding how an
experiment must be designed) show that many of the effects experienced only
manifest themselves a few hours after exposure, and have often not fully
subsided until the following day. This also seems to vary from person to
person, but it is hard to evaluate what the reason for this would be. Both
of these points are hard to properly incorporate into the design of the
There is very little the study authors can do about the withdrawals, aside
from comment on the potential damage that they can do to the statistical
resolving power of the data (i.e. the chance that all 12 would be 100%
"sensitive" participants and the chance that all 12 would be 0% "sensitive"
participants would both greatly skew the data). It would be useful perhaps
to keep a record of those withdrawing due to excessive symptoms, to create a
"pool" of people that seem to exhibit highest sensitivity (see next point
Nocebo responders are also very hard to sensibly deal with as a confounder,
due to having no prior knowledge of who they are - this is especially true
when cause is not established and it is a theoretical possibility that all
fall into this category. However, there are certain steps that can be taken
to separate out those with highly successful responses, perhaps with the aim
of adding them to the "highest sensitivity pool" (see point above). This
gives the opportunity to test those that seem to be the most sensitive in a
given study without the possible confounders of nocebo sufferers. This was
not done here, but in fairness to the authors this would require another
round of tests and may not have the required participation from the selected
group (who may not want to go through another round of tests).
The problem of effects experienced after a few hours (but not immediately)
was addressed by the study, which tested for symptoms very shortly after the
end of the exposure and allowed the participants to fill in a questionnaire
to return the following week. However, there is a good argument for it not
being necessary as the sensitive group have reported much higher levels of
perceived symptoms than the control group anyway. This gives reasonable
support to the idea that the authors have designed it in a way that should
find effect if there is one.
There is the added possible confounder that the sensitive group were
suffering from stress responses based on the pressure of believing they
might be exposed, and again this is something that it is not reasonable to
expect the authors to eliminate. However, it is a very important issue in
these double-blind provocation studies that can not be ignored.
The problem of responses not subsiding until the following day has been very
well catered for by the research team, as the tests were separated by a
period of one week in each case.
All in all, the Essex team have carried out one of the best designed and
executed studies to date. They consulted widely during the planning stages
and took notice of a wide variety of sources (including Powerwatch and some
individuals who claim to be electrically sensitive). We were present when
Sir William Stewart opened their testing laboratory. Their laboratory is
well designed and uses non-toxic paints and DC lighting to help eliminate
Whilst there were distinct problems early on in the realism of the exposure
system, by the time the actual provocation tests were performed it was the
best we have seen in an experiment to date, including a well designed
simulation of real network traffic. Measured background EMFs in the lab are
negligible (the rooms were screened to a 60 dB reduction in field strength),
and thus one of the biggest flaws of Rubin's work has been dealt with
As with all double-blind studies, there is no way in which the effects of
chronic exposure can be addressed, so this is not a failing of the study but
another point for consideration with regards to final conclusions.
Following this paper, it is becoming increasingly likely that there is a
significant proportion of self-assessed Electrically Sensitive people whose
response is entirely nocebo - whether induced by fear of harm or other
reasons, the cause is not radiofrequency EMFs.
There are fundamental flaws in the idea of evaluating subjective responses
in a double blind system that simply cannot be avoided regardless of the
care taken on experiment design (such as the potentially large proportion of
nocebo responses). There is also a chance that chronic exposure may give
rise to genuine symptoms whereas acute exposure may not, but that cannot be
addressed by this study.
So whilst it cannot be entirely ruled out that a small minority are truly
sensitive, the proportions of any truly sensitive people are likely to be
far lower than the 3% - 35% that has been quoted.
May be worth mentioning this brand new
research that came out
only a few days ago from Imperial College and was reported in the
Electrical fields generated by everyday electrical equipment such as
computers, and excess static charge created by many modern materials, could
be bad for your health, says new research published by Imperial scientists.
The study, published in the Atmospheric Environment journal in August
2007, strongly indicates that prolonged exposure to the electric fields
generated in everyday indoor environments may cause increased risk of
respiratory diseases and infection from small airborne particles such as
allergens, bacteria and viruses. The study also found that such risks may be
far higher than previously thought.
These electrical fields have also been shown by the authors to
significantly reduce localised concentrations of charged molecular oxygen, a
type of small air ion, that enhances biological functioning and kills
Over 90 per cent of airborne particles can be in the size range which
is affected by these fields - less than one micron in size, 80 times smaller
than a human hair. Whilst they can remain air-borne almost indefinitely,
deposition of these tiny particles in people's lungs and on their skin can
be greatly increased by electric field effects, particularly when they are
in close proximity to oppositely charged surfaces.
Lung deposition of such particles can be increased as a result of the
electrostatic charge they hold causing "mirror" charges of opposite polarity
to be induced on the neutral surface of the respiratory tract, thereby
increasing their deposition over uncharged and charge neutralized particles.
Electric field levels can also vary with the humidity levels of the
air, with below 20-30 per cent relative humidity causing marked increases in
the level of fields that can be generated and thereby increasing incidents
of deposition and infection.
The researchers suggest that the presence of such fields indoors may
cause a significant increase in the deposits of this kind of particles in
people's lungs and on their skin. In addition to relative constant field
levels, temporary incidents of excess charge, which occur through fictional
charging of certain materials - such as when a hospital worker makes up a
patient's bed - can further increase likelihood of contamination.
Increased deposition of these particles increases the toxic load that
the body has to deal with, raising the risk of contamination, bacterial
infection and incidence of conditions such as asthma. Additionally, surface
contamination can prove harder to remove, as particles' deposition speeds
are increased under high fields causing greater deformation on impact,
making them stick harder to the surfaces they land on.
Keith Jamieson of Imperial's Centre for Environmental Policy, lead
author of the paper, says: "Many of the factors that can cause high electric
fields and increased deposition and contamination are often found in
hospital ward environments and in buildings where incidents of sick building
syndrome are noted."
The researchers propose, however, that adopting a number of simple
guidelines in home, office and hospital environments could reduce the size
of electrical fields generated, and therefore reduce the levels of
potentially unhealthy particles deposited on the skin and in the lungs as
well as making surface contamination far easier to remove.
Keith Jamieson explains: "In the case of electrical equipment,
particularly laptops, ensuring they are earthed can often greatly reduce
fields. In terms of the electrostatic charge generated by people themselves,
careful selection of materials and humidity levels can significantly reduce
problems as can balanced bipolar air ionisation. Trying to avoid spending
time in areas where high fields are created, and unplugging electrical
equipment when not in use, are also good options - so there are a number of
easy actions which can already be implemented in the workplace and the home
to help reduce the toxic load our bodies have to deal with and the risk of
illness and infection being transmitted in this way."
Sarah Dacre MSc ACIB