BioEM2015: Inadequate design of studies causes waste of time, money and researcher potential

Out of many presentations, here are few words about a study on EHS. This study is a good example of what is wrong with the EHS research.

Scientists examined whether exposure to wifi radiation affects how people feel mentally and physically.

Wifi exposures were measured by using meters carried by study subjects.

Changes in physical and mental wellbeing of study subjects was recorded in diaries, carried by the study subjects and filled out at certain time intervals.

The final conclusion of the study was that there is no correlation or, if it was “seen” (=imagined), it was very weak.

However, there is a major problem with the design of this study. Mood or wellbeing of study subject can, and certainly is, affected by situations they find themselves in during the day. This was not corrected for in the study. It was as if the “only” reason for headache is wifi exposure…

Not correcting for other parameters affecting wellbeing makes the final data misleading and useless.

Lots of time, money and researcher effort was put in yet another study with useless conclusions…


Here is the abstract of this “inadequately” designed EHS study, copied from the abstract book of BioEM2015.

Association of EMF exposure with non-specific physical symptoms within individuals

  • John Bolte1, Sander Clahsen1, Wendy Vercruisse1, Irene Van Kamp1, Anne van Gils2, Judith Rosmalen2 & Rik Bogers1
  • 1Centre for Sustainability, Environment and Health, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands, 3720BA; 2Interdisciplinary Center Psychopathology and Emotion regulation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands, 9700RB

This study explores relationships between exposure to radiofrequency electromagnetic fields and non-specific physical symptoms within individuals over time, as studying exposure response relations in groups of persons may average out associations existing on an individual level. The focus is on specific EMF frequency bands and symptoms that the participants indicated to be relevant for their particular situation. Participants registered non-specific physical symptoms and perceived RF-EMF exposure using an electronic diary daily at three set times for a period of three weeks. During the same period personal exposure was monitored using exposimeters. Statistical analyses are currently ongoing and will be finished in April 2015.


Some people experience non-specific physical symptoms (NSPS) in the proximity of sources of electromagnetic fields (EMF). When an individual attributes these symptoms to the exposure to EMF, this is often referred to as electrohypersensitivity (EHS) or idiopathic environmental intolerance attributed to EMF (IEI-EMF) (World Health Organization 2005). Frequently mentioned symptoms include fatigue, headaches, concentration problems, vertigo and sleeping problems (Röösli et al. 2004; Schooneveld and Kuiper 2008). The prevalence of EHS ranges from 1.5-5% in the general adult population (Hillert et al. 2002; Levallois et al. 2002; Schreier et al. 2006), to 13% (Meg Tseng et al. 2011). These differences are possibly due to the population under study (Western countries vs. Taiwan), and probably also the instruments or definitions used (Baliatsas et al. 2012). The prevalence in the Netherlands is estimated to be 3.5% – 7% (Baliatsas, al., 2011). Several IEI-EMF groups have

been distinguished based e.g. on the co-occurrence of chronic physical disease or psychopathology, and general or sourcespecific sensitivity. Until now no clear associations between exposure to RF EMF and NSPS was found. However, the vast majority of scientific studies on IEI-EMF have neglected the heterogeneity within the IEI-EMF group. As a result, in statistical analysis, associations between exposure and symptoms may be averaged out by analyzing the results only at group level. An alternative to studying exposure response relations at group level is the idiographic approach, in which repeated observations are used to study the relationship between exposure and response within individuals over time.

The goal of this project is to explore the use of idiographic studies to find whether associations exists between exposure to RF-EMF and IEI-EMF at the individual level. Idiographic studies are potentially relevant for the study of IEI-EMF, because the symptoms, and the sources and frequencies of EMF to which patients attribute their symptoms, are often specific to an individual. Therefore, this project piloted a preliminary set of questions to discriminate subgroups of IEI-EMF. Eventually this set of questions can be used in practice by e.g. general practitioners and occupational physicians to tailor their treatment to the needs of the individual patient. In case of positive findings (i.e. significant individual exposure with symptom associations), results of the project may further contribute to the refinement of a discriminatory index, for example by providing information about person-specific symptoms and lag-times between exposure and symptom occurrence that can be used in further testing for sensitivity to EMF.


The study consists of two steps. First, in order to find suited participants, a preliminary set of questions to discriminate subgroups of IEI-EMF derived from previous work at RIVM in the Dutch national research programme on EMF & Health of the Netherlands Organisation for Health Research and Development (ZonMw) has been further developed. This set of questions was selected from the Emphasis study database (Baliatsas et al., 2015) on self-declared radiofrequency EMF hypersensitive individuals with symptoms that do not appear to result from physical or mental disease, and whose symptoms and RF-EMF exposure vary during the day. Further, potential participants had to attribute their symptoms to sources in frequency bands that were in the measuring range of our type of exposimeter.

In the second step, seven volunteers were recruited from the group identified in the first step. They were requested to register NSPS, momentary mood states and perceived RF-EMF exposure using an electronic diary for a period of three weeks. The electronic diary was filled out three times a day, with six-hour intervals (e.g. 9:00, 15:00, and 21:00). During the same period, personal radiofrequency (RF) EMF exposure was monitored using RF-EMF exposimeters of type EME Spy 121 (Satimo, Cortaboef, France) with a sampling interval of 28 seconds. Data will be analyzed using ARIMA, which is suitable to study relationships between outcome and exposure within individuals. To diminish the risk of false-positive associations, the focus will be on specific EMF frequency bands and symptoms that the participants indicated to be relevant for their particular situation (Table 1)

Table 1

To find any relevant and significant association between time lagged NSPS and exposure, both a contrast in exposure and a contrast in reported NSPS over the three time periods (night, morning, evening is necessary. As exposure characterization requires both measures for central tendency and short term variability we chose as metrics time weighted average (TWA), 30 rate of change metric (RCM) and the number of peaks or registrations above a, frequency band dependent, threshold (Table 2).

Table 2


Analyses are currently ongoing and will be finished in April.


We thank the Netherlands Organisation for Health Research and Development (ZonMw) for funding this project .


  • Baliatsas C, Bolte J, Yzermans J, Kelfkens G, Hooiveld M, Lebret E, Van Kamp I, 2015. Actual and perceived exposure to electromagnetic fields and non-specific physical symptoms: An epidemiological study based on self-reported data and electronic medical records. International Journal of Hygiene and Environmental Health, First published online 7 February 2015. doi:10.1016/j.ijheh.2015.02.001
  • Baliatsas C, Van Kamp I, Lebret E, Rubin GJ, 2012. Idiopathic environmental intolerance attributed to electromagnetic fields (IEI-EMF): a systematic review of identifying criteria. BMC Public Health 12 (1), 643.
  • Baliatsas C, Van Kamp I, Kelfkens G, Schipper M, Bolte J, Yzermans J, Lebret E., 2011. Non-specific physical symptoms in relation to actual and perceived proximity to mobile phone base stations and powerlines. BMC Public Health (11):421.
  • Hillert, L., N. Berglind, et al. (2002). “Prevalence of self-reported hypersensitivity to electric or magnetic fields in a 31 population-based questionnaire survey.” Scand J Work Environ Health 28(1): 33-41.
  • Levallois, P., R. Neutra, et al. (2002). “Study of self-reported hypersensitivity to electromagnetic fields in California.” Environ Health Perspect 110 Suppl 4: 619-623.
  • Meg Tseng, M. C., Y. P. Lin, et al. (2011). “Prevalence and psychiatric comorbidity of selfreported electromagnetic field sensitivity in Taiwan: A population-based study.” J Formos Med Assoc 110(10): 634-641.
  • Röösli, M., M. Moser, et al. (2004). “Symptoms of ill health ascribed to electromagnetic field exposure–a questionnaire survey.” Int J Hyg Environ Health 207(2): 141-150.
  • Schooneveld, H. and J. Kuiper (2008). Electrohypersensitivity (EHS) in the Netherlands. A Questionnaire survey. 2nd graphical edition.
  • World Health Organization (2005). Electromagnetic Hypersensitivity, WHO factsheet no. 296, World Health Organization.

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