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Friday, July 14, 2017

Detailed Review of 2016 EHS exposure study

The following study "Effects of personalised exposure on self-rated electromagnetic hypersensitivity and sensibility – A double-blind randomised controlled trial" (http://www.sciencedirect.com.sci-hub.cc/science/article/pii/S016041201630931X) was aimed to face the criticism of older exposure studies and to once and for all test if EHS people can feel the exposure.
The study result was that overall subject could not identify the exposure in "better than chance" ratio (see section 3.2 in the full study).

About the study

  1. The study concluded of 42 subjects.
  2. The subjects were given 4 questionnaires, one as baseline, second in the home visit before the exposure, third after the exposures (after the outcomes were shown to the subjects), forth as a follow up after 2 months and the fifth as a follow up after 4 months. In these questionnaires they were asked about their symptoms, level of sensitivity, certainty of being sensible/sensitive to EMF, and certainty of reacting to EMF within minutes. 
  3. Each subject was asked which type of radiation, and at what level he will be able to detect in few minutes. 
  4. Exposures types were:  GSM 900, GSM 1800, DECT, UMTS (2100-2170), WIFI , 50Hz sine wave ELF magnetic field + four other different types of other signals in other frequencies to simulate "Dirty Electricity".
  5. Minimum level of RF was 0.2 V/m and the maximum was 6V/m.
  6. Minimum level of ELF was 0.2 uT, and the maximum was 6.6uT.
  7. 4 subjects chose ELF, other chose different types of RF.
  8. The first exposure was an open exposure to make sure that the subject can sense the radiation. 
  9. Followed by 10 sessions of Exposure+rest time(for recovery), each cycle lasting not more than 15 minutes. all cycles took not more than 150 minutes. 
  10. 3 to 7 out of the exposures cycles were real, other were sham exposure. 
  11. Subjects were tooled that at least one of the cycle will be real exposure. 
  12. After the testing was concluded, the results were shown to the subjects and he was given a Quaternary again. 
  13. 39 subjects out of 42 were tested at home. 
  14. In order for a subject to be titled as "sensible" he needed to identify if real exposure of sham in at least 8 out of 10 cycles. Only 2 out of subjects were able to achieve this. 
  15. The study was supported by the Netherlands Organization for Health Research and Development (ZonMW)


In comparison with older studies, this one is better in the following ways:

1. The trails were done in a place that the subjects felt comfortable in, so no EMF rich lab and no exposure during traveling to this lab.
2. The exposure was aimed to be to a radiation type the subject is most reactive to (we will explain what went wrong there). 

But this does not mean it is a good study.

Following are what I see as problems in this study:

  1. No Physical measurements - None of the tests included physical measurements, the subjects were only asked if they feel or sense the radiation or not.
  2. Not enough recovery time -  The researchers estimate that a Max duration  of 15 minutes will be enough time for exposure and then to recover after the exposure. 10 double blinded exposure+rest cycles were done one after the other. Each cycle consisted of exposure+rest(recovery) time, not more than 15 minutes for each cycle . Most EHS people I know will not be able to fully recover after only 15 minutes(the max possible in this study) recovery time after exposure.
  3. Wrong estimation that EHS people can sense the radiation - The researchers estimate that the subjects, which are EHS people, had the ability to "sense" the radiation after few seconds or minutes.  This assumption is wrong as most EHS people can't sense the radiation. Most EHS feel bad when exposed, sometime after few minutes, sometimes after few hours, and the recovery time is usually longer then few minutes. 
  4. Exposure type was determinate with not real tests(by....asking) - In order to determine what was the type of radiation a subject is the most reactive to, the researchers asked the subject (!). They then exposed each subject in an open session where he could see he is being exposed. If the subject said he can sense the radiation they concluded that this is the best type of exposure for him. This was concluded without physical measurements and in an open session when the subject could see he is being exposed. 
  5. Radiation levels in the test environments were not measured - The environments in which the exposure test were done, was not tested and verified to be with no radiation other than the planed exposures. 
  6. Suspicion for unbalanced approach, expecting the subject to fail - The researchers devoted a big side of the study to see if and how the subjects' conception of their EHS condition changed after they were shown the results of the exposure tests. This is a question of a psychological nature and may suggest an an-balanced approach of the researchers (It feels like the researchers weer expecting the subjects to fail the tests, this can have influenced the design and execution of the study).

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