Essex electrosensitivity study results…

July 25th, 2007 by Ben Goldacre in bad science, electrosensitivity | 162 Comments »

… and they’re negative. Subjects were unable to distinguish whether the signal was present or absent. It is truly fantastic that for almost the first time ever the discussion around electrosensitivity is actually addressing the evidence, rather than anecdote. Cue a barrage of abuse from the electrosensitive lobby.

I’ll be updating as responses from lobbyi$ts and news coverage comes in, do please post links and text below and I will link to them.

Most importantly, I have a close personal relationship with knowledge, and it has disclosed to me its desire to be free. Therefore here is the original academic paper, so you can make your own mind up about it:


The first responses are out.

This is Graham Philip$ from Pow£rwatch (aka topazg below, they sell these but hate this):

Their first argument is that the drop outs may have been the “true” electrosensitives, leaving only people who are not. So interestingly, they are accusing people who believe themselves to be electrosensitive of not being electrosensitive. This would traditionally elicit a barrage of abuse from people like… Rod Read of Electrosensitivity, and indeed Pow£rwatch themselves. It will be very interesting to see how the subjects who did stay in the study, who genuinely feel themselves to be electrosensitive, react to this dismissal by Philip$.

“Electrosensitivity” say this study merely shows that mobile phone base stations do not cause symptoms, but other forms of e-m still do cause symptoms. And they don’t like the fact that the research was done by psychologists.

The BBC are reporting it as real symptoms, not due to EM but rather psychological.

Amusingly the last time the BBC discussed the Essex study it was on hard-hitting fact based news documentary show Panorama. I described it at the time thusly:

… A recent Panorama documentary on BBC 1 covered the possible dangers of Wi-Fi computer networks, and what little evidence the programme did present was flawed in a number of ways.

A large chunk of the programme was devoted to electrosensitivity. It covered the question of testing the phenomenon, in a double blind study.The programme makers even followed someone into a lab at Essex University where they had participated in one provocation study. We are told that this subject did correctly identify when the signal was present or absent two thirds of the time, to a visual backdrop of sciencey looking equipment.

But this was anecdote dressed up as data. The study is currently unpublished. We don’t know the protocol, or whether 2/3 for one subject would be statistically significant (there may be only three exposures in total, for example). We don’t know the results of the other subjects. But most crucially, there is no mention that this single selected subject in a single unpublished study produced a result that seems to conflict with a literature of 37 studies that have been completed, published, and are overall negative. If this whole Essex study was positive, while it might make an interesting small splash next to the other 37, it would need to be replicated and considered in the context of the negative findings. The alternative is chaos, and being blown in the wind by every Type I error…

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162 Responses

  1. pv said,

    July 31, 2007 at 11:45 pm

    Henrik, what is interesting to me is the way you doggedly stick to the “electrosensitivity exists” line, just like Dr Wakefield’s supporters stick to the “MMR causes autism” line, in spite of all the evidence to the contrary and not a shred of supporting evidence.
    It’s interesting how you religiously discount the possibility of a psychosomatic cause of the effects you like to ascribe to EMS, in spite of the well conducted research evidence that points precisely in that direction.
    And, I repeat, why do you want to ignore the five members of the control group who guessed correctly each exposure to EMR? The only way it appears you can accept them is by including them with the electrosensitives and insisting they couldn’t possibly have been guessing.
    It seems to me you are looking for ways to “interpret” the study to fit with your world view, rather than listen to the researchers. That’s interesting.

  2. Robert Carnegie said,

    August 1, 2007 at 1:40 am

    paul77, that’s interesting – but it must be difficult to exclude the possibility of another cause. One that comes to mind is that your devices may produce radiation of sound, perhaps beyond the range of hearing, or vibration when held in the hand. Or you could react against the material they’re made from, or some contamination. I wonder if an asthma sufferer would have a long-term problem with a smoker’s second-hand phone? Or you may use the phone at the end of a train journey, in which case it’s the air conditioning or a hundred other minor discomforts of modern travel and modern life. Or it’s the electronics. But anyway, maybe you could volunteer for someone’s next experiment? Or carry the thing in a muffling case, or wrapped in sandwich-wrap plastic? I take it you don’t have a heart pacemaker?

  3. tom1 said,

    August 1, 2007 at 10:31 am


    you cover a lot of ground. One thing to point out is that over the years CB radios have been credited muddled up in this as well (cancer risk for one thing, I’m not sure about EMF sensitivity).

    Do you get symptoms from power lines? Again, these have traditionally been seen as causing both the cancer and the sensitivity.

    Can somebody suggest a good readable paper on this whole confirmation bias/misattribution of cause thing that we 🙂 all feel is going on here? Preferably with a killer anecdote or two. An anecdote is afterall worth a thousand statistics.


  4. tom1 said,

    August 1, 2007 at 11:55 am

    I suppose all the homeopathy/crystal healing confirmation by anecdote would apply.

  5. tom1 said,

    August 2, 2007 at 11:04 am


    you mention various frequencies in the MHz range. Generally speaking the anti-EMF movement has been concerned with frequencies around 50-60Hz because of the link to AC power transmission. The argument generally is that there are ‘pulses’ within the higher frequency waves in the 10-100Hz range that cause the trouble. In so far as I’m aware of it though the vast bulk of 30+ years of research indicates that there is no effect even within this range. One question though, what kind of EMF field will be given off by a pda running off the battery? All the talk about fields given off by hairdryers etc have been with them plugged into the AC mains.


  6. paul77 said,

    August 2, 2007 at 1:33 pm

    One more thing: yes, I’d be happy to participate in a blind or double blind study. But I think in order to prove what I am claiming, it would have to be done with the actual device (or same model device) obviously in such a way that I wouldn’t be able to tell whether it’s on or off. I’m confident that, given enough trials, I’d be able to tell if I’ve had had a recent exposure to the EMF’s.

  7. tom1 said,

    August 2, 2007 at 1:34 pm


    in the cold dank world beyond the reach of the warm sun that is Ben Goldacre, this issue has been investigated to death. I’ve been reading up on it for the past couple of weeks.

    The reason for the 50-60Hz thing is that if it’s a static field then it would be drowned out by the Earths magnetic field, the theory goes that an alternating field is new and artificial and therefore we aren’t adapted to it.


  8. paul77 said,

    August 3, 2007 at 12:38 am


    I understand what you’re saying, but I’m sure the symptoms are not “physiological noise” or anything like that because I can’t simply tune out from them as though they were there all the time and I was just being introspective. They are very uncomfortable to say the least.

    Why no study to date has shown electrosensitivity to be correlated with EMF exposure, I don’t know. But perhaps the way the experiments are conducted needs to be reconsidered and perhaps a larger sample size used. I don’t know. But I am confident that one day there will be a study able to be repeated that will show electrosensitivity symptoms are not simply “all in the mind” and that EMF’s from the devices are the most likely explanation.


  9. tom1 said,

    August 3, 2007 at 9:32 am


    I absolutely agree. There are a whole load of other ‘real’ causes that need to be discounted. Given that the effect is not immediate, it may not even be the device. It is so easy to see faces in the wallpaper and impose structure on random coincidence.


    Are you effected by wifi? Are you effected by power lines? I find the whole pda thing troubling because I don’t see that that would be generating much of an alternating field. Could somebody confirm this?

    I can see that perhaps your pda could cause a localized effect, but spots in front of your eyes? What mechanism could be causing this? Are you sure they aren’t just common or garden floaters?


  10. madtechie said,

    November 1, 2007 at 10:52 am

    I’m surprised that the electro-sensitive lobby haven’t had a tilt at medical MRI scanners (or have they, and I’ve missed it?)

    An average 1.5T scanner operates at a peak RF power of 16-20KW (at around 63MHz) – though obviously the duty cycle is low, or thermal effects would cook the patient.

    Even so, an average power deposition in the body approaching 0.4W/Kg is usual.

    If we believe some of the worst rantings of the electro-sensitive lobby, we should be able to detect a substantial group of patients whose health has deteriorated after an MR exam, due to EM effects.

    I don’t recall seeing any such correlation reported…must be Big Pharma’s cousin, Big Scanner Manfacturer suppressing the data.

  11. paul77 said,

    November 9, 2007 at 12:51 am

    Madtechie, your suggestion that we should expect to see a substantial group of patients who’ve had MRI scans complaining of electrosensitity isn’t necessarily true.

    Firstly, MRI scanners use different frequencies to devices like mobile phones or handheld computers that electrosensitive people like myself have complained about. Electrosensitivity may well be frequency related in which case there might not be any effect from an MRI scanner in spite of the intensity of the fields it produces.

    Secondly, how many people have regular MRI’s? Sure, you might have a once off MRI for something. But suppose you are electrosensitive to the MRI machine, how would you be sure unless you’re having regular scans to know of a correlation?

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