Electrohypersensitivity: Provocation studies (1999-2017)

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Université de Liège
Unité de Psychoneuroendocrinologie (PNE)
Sart Tilman, CHU B-35 | 4000 Liège

Activity reports


C. Brabant, I. Demaret, M. Ledent, G. Scantamburlo, M. Ansseau

Within the framework of the BBEMG project, the Unit of Psychoneuroendocrinology studies Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI-EMF, aka electro hypersensitivity) form a psychoneuroendocrinological perspective.

During the past four years (2013-2017), we have interacted with the public to provide information to people who were concerned about the potential effects of electromagnetic (EM) fields on health. Moreover, we have interacted with many subjects suffering from IEI-EMF (IEI-EMF subjects) who have contacted our unit to seek help. We have helped these subjects by listening to their stories. We have provided practical advice so they could learn to distance themselves from potentially harmful EM sources. IEI-EMF subjects were redirected to specialists if mental or physical illnesses could explain their symptoms.

Some evidence suggests that IEI-EMF subjects are on average more anxious than regular people. Therefore, we have further examined the characteristics of IEI-EMF subjects in our studies (2013-2017) by focusing on anxiety and the HPA axis. IEI-EMF subjects were compared to control subjects using a double blind procedure. All the subjects completed questionnaires that were designed to measure electro hypersensitivity symptoms. In our experiments, the subjects were wearing a helmet that generated an EM field of 50 Hz and 20 μT for 45 min. The helmet was turned on (EM field ON) or off (sham condition) depending on the experimental conditions. Blood samples were taken to assess hormone levels (ACTH, cortisol, oxytocin) and anxiety levels were evaluated using the STAI.


C. Rocha, M. Crasson, M. Ledent, M. Ansseau

During the period, we ended the research on “Assessment of clinical and psychological effects of exposure to a 50 Hz magnetic field on cognitive performance and delayed symptoms”. We have 135 participants including more than 60% of women with an average age of 45-year-old. We found higher levels of anxiety, depression, negative affectivity, psychiatric symptoms and symptom amplification significantly higher among EHS people vs controls. Only positive affectivity and health-related beliefs do not differ from one group to another.

Regarding cognitive tests, there was a significant difference between EHS and controls before exposure. For example, results showed that EHS people were less effective in the D2 questionnaire (assessing visual attention and concentration ability.

It is important to note that symptoms reported by individuals with EHS are real, even if it cannot be “objectively” attributed to electromagnetic fields. Indeed, in this study, we highlighted the inability of EHS people  to better determine the presence of a magnetic field of extremely low frequency compared to the control group.

Following discussions with the EHS participants and the growing demand of taking charge, we wanted to develop a program of psychological care of EHS patients. Given that cognitive behavioral therapy (CBT) is effective in many other unexplained syndromes, it should also be useful for patients EHS. This hypothesis has already been examined by some researchers. In the literature review conducted by Rubin et al. (2006), three of the four studies testing the effectiveness of CBT for EHS show better results for the experimental group than for the control group (reduction of subjective suffering, reducing the severity of symptoms, reduction of disability and reducing the number of people describing themselves as EHS).
In comparison with other solutions (filter screen, “shielding” issuers EMF antioxidant supplementation therapy), CBT is the most effective.

Then the purpose of our research aimed to support psychological symptoms with psychotherapy structured cognitive-behavioral orientation…

Until now, eight EHS received 10 sessions of psychotherapy. We can observe an improvement in all aspects studied and a decrease in the perceived impact of electricity on the well-being, in different areas of life. Psychotherapy could help EHS patients feel better.

For a round tour on this topic, see our Electrosensitivity/EHS module.


M. Crasson, S. Nevelsteen, J.J. Legros, M. Ansseau

Hypersensitivity to electricity (EHS) – Idiopathic environmental illness attributed to electricity

Hypersensivity to electricity or electrosensitivity, also called idiopathic environmental intolerance by the World Health Organisation, is related to complaints expressed by certain people in relation to the use or proximity to electrical devices or installations.

The goal of this research is to better characterise this illness (symptom report, sources etc. throughout a questionnaire specially designed) and delineate the factors involved in the development and/or maintaining of this problem. People complaining about hypersensitivity to electricity or questioning themselves about this relationship are compared to subjects without complaints related to electromagnetic field exposure. Cognitive (working memory and concentration), psychological (psychological distress, well-being, etc.) as well as psychophysiological (event-related potentials or ERPs: P300 and CNV) parameters have been selected for this purpose. This assessment is realised in one half-day of clinical evaluation (blood sample, cognitive tasks, psychophysiological recording, interview, open field provocation test) or 3 half-days (1 half a day of clinical evaluation and 2 double blind provocation tests). This protocol was approved by the Ethic Committee.

We received 77 questionnaires from which 55 were analysed. In summary, the data from the specially builded questionnaire (M. Crasson) indicated that EHS subjects were more often well educated subjects and women. They report numerous and various symptoms, some of them comparable of those observed in the hyperventilation syndrome. They also report a higher number of environmental annoyances. Aggravating factors and improving factors are often environmental ones and associated to the perceived exposure to EMF. Avoidance behaviour and shielding are often used as coping strategies. Although the well-being is worsen by their problem, the majority of EHS subjects were able to work or to go out. Radiofrequency fields are the most incriminated sources of exposure in this sample. Very few subjects are complaining only about ELF fields.

The data of psychological scales (n=26 EHS) indicated a high level of psychological distress and depressive symptoms as well as a more anxious temperament than the control group. The cross-over design of this study does not allow to conclude if it is the cause or the consequence of their electrosensitivity. However, a higher level of trait anxiety could represent a possible factor of vulnerability for developing or maintaining an environmental illness and/or a higher mental distress.

Twenty seven subjects participated in the ERPs recordings and 30 in the cognitive evaluation (working memory and concentration tasks).

We observed a statistical slowing of mean reaction time in the warning paradigm (VCN) and a lower number of items processed in the D2 concentration task. The electrophysiological data didn’t indicate any difference during these performance tasks. Consequently, we can make the hypothesis that the control subjects were more motivated to perform the tasks rapidly, as a challenge. The higher number of errors in the oddball paradigm (P300) in the EHS group could be interpreted as a lesser discrimination ability and warrants further investigation.

Finally, the open field provocation test indicated that the 14 EHS subjects, who also participated in the double blind study, reported more symptoms when they are exposed the 50 Hz MF (20 µT), knowing that they are really exposed. It was observed whatever the incriminated source of exposure (ELF, EF, ELF+RF). However, in the double blind provocation study, the EHS group was not able to perceive the presence of MF better than chance.

Communication strategies are put in place regarding EHS throughout individual information, the BBEMG web site, conferences and training, and the collaboration with teams working in other disciplines.


M. Crasson & J.J. Legros

The role of information on the report of symptoms

Objectives : The goal of this research was to analyse the importance of risk perception as a pathogenic factor of “electrosensitivity”, and more specifically, the effects of expectancies and beliefs. We analysed the role of expectancies and the effects of acute exposure of 50 Hz magnetic fields (400µT) on cognitive performance, reporting of symptoms and some psychological and physiological parameters including urinary 6-sulfatoxymelatonin concentration.

Method : The 74 volunteers were randomly assigned to one of the five groups. These were different according to the type of information (positive, negative or neutral) that magnetic field exposure was expected to have on the performance of the subject on cognitive tests and the type of exposure (real or sham) (group “+”: positive and sham; group “-“: negative and sham; group “+/-“: neutral and sham; group “expo”: neutral and real and group “control”: no information and no exposure).

Results and conclusion : The information given did not significantly modify beliefs. No significant difference was found between the five groups, according to the type of information and the type of exposure, in cognitive performance, symptom reporting, mood, vigilance, blood pressure, pulse rate and urinary 6-sulfatoxymelatonin concentration profile.

Symptom reporting is not associated to the belief of being exposed to magnetic fields or by real exposure. To better understand what caused symptom reporting, a regression analysis was made. The regression model included 4 selected variables (state of anxiety, satisfaction of the Visual Analogue Scale (VAS), positive affectivity and comfort under the helmet) and explains more than 30 percent of symptom reporting (R2 adjusted = 0.32, F (4,66) = 9.37, p<.001). This model explains more than 30 percent of the report of symptoms and strengthens the hypothesis that symptom26/01/11by a psychological process of anxiety (Pennebaker, 1994).

In the context of the study, with a population of healthy men without any anxiety symptomatology, the type of information given failed to induce expected changes in parameters measured. It seems appropriate to use a more arousing message which could induce more emotions and lead to cognitive, emotional and somatic reactions attributed to magnetic field exposure and to test as well the impact of information and EMF exposure on people who have characteristics in common with EHS sufferers such as women.

Clinical research activities – Idiopathic environmental intolerance attributed to electricity, electrosensitivity, electrical hypersensitivity

Electrosensitivity is a self-defined condition where individuals experience adverse effects while using or being in the vicinity of devices or equipment emitting electric, magnetic or electromagnetic fields. Most of the studies are Scandinavian and indicate dermatological complaints from visual display units workers. However, more and more individuals complain about a general syndrom, neurasthenic-like, which extends to other sources of non-ionising radiation, power-lines and mobile systems. The use of the term “electrosensitivity” or hypersensitivity to electricity” cannot be considered to imply an already established causal relationship between electromagnetic fields and symptom reporting, as shown by provocation studies. The origin of electrosensitivity appears to be multifactorial and this heterogeneous illness requires a multidisciplinary approach in diagnostics and treatment.

In this project, the question of electrosensitivity was examined in more detail by mean of clinical interviews, evaluation and follow up of people claiming to be hypersensitive to electromagnetic fields. A review paper was published in the European Review of Applied Psychology ( Crasson, M. (2005). Revue Européenne de Psychologie Appliquée, 55(1):51-67).

Testing and sometimes a follow up were carried out with around 20 people complaining about electrosensitivity. Due to the fact that people often have to make a long trip to come to our unit, we generally organize a one day evaluation, including a complete anamnesis and a clinical evaluation (M. Crasson), blood sampling and medical examination (Prof. J.J. Legros) including a blood sample sent to the VITO for genetic investigation (Prof. Verschaeve). The medical examination is required to identify and treat any specific medical diseases that may be responsible for the symptoms reported.

Provocation tests were performed when EMF exposure induced direct reactions and when the person consented to perform them (11 cases). They did not lead to conclude that people were able to detect EMF exposure (9 tests with 50 Hz MF and 2 tests with RF fields). No evidence of any causal relationship between EHS symptoms and 50 Hz MF exposure or « GSM » fields was established.

Particular attention was paid to the management of EHS symptoms, to the information related to EMF health effects and to the follow up of EHS patients. A standardised interview and a list of questionnaires were analysed and established for the evaluation of EHS people in the future.


Sensitivity to Electricity

M. Crasson, L. Verschaeve, P. Pirotte, M-T. Hagelstein, J-J. Legros

Some cases of presumed ‘electrosensitivity’ have been seen in the Psychoneuroendocrinology Unit. Subjects claimed to be sensitive to artificial ELF electromagnetic fields or to something related to electricity use. Medical and psychological evaluations, as well as provocation studies, were conducted to identify and better characterize this syndrome.

Blood samples were sent to the VITO for genetic tests (L. Verschaeve). In some cases, residential MF measurements were made by Prof. P. Pirotte, and urinary samples were collected for aMT6s (melatonin metabolite) concentration measures. The cases were so different that a uniform profile could not be drawn. The inconsistency in results obtained with the medical examination and with the provocation studies (see below) suggests that the potential association between EMF and symptoms is complex and restricted to certain conditions, and confounded by exposure to other stimuli. Further clinical studies are needed to better understand this syndrome.

Publications related to BBEMG activities

 Ledent, M., Beauvois, V., Demaret, I., Ansseau, M., Scantamburlo, G. (2015). Champs électriques et magnétiques 50 Hz et santé : quel message au grand public ? Rev Med Liege 2015, 70(4),172-178.
>> See a free pdf version

Communiqué SPF Santé Publique, Sécurité de la Chaîne Alimentaire et Environnement dans le Journal du Médecin du vendredi 14 décembre 2007: « Champs électromagnétiques et santé », co-rédaction Marion Crasson (docteur en psychologie, chercheur qualifié à la Faculté de Médecine) et Jacques Vanderstraeten, experts scientifiques.

Nevelsteen, S., Legros, J.J., Crasson, M. (2007).
Effects of information and 50 Hz magnetic fields on cognitive performance and reported symptoms.
, 28(1): 53-63.

Crasson, M. (2005).
Champs électromagnétiques et santé.
Médecine du travail et ergonomie, XLII, N°1, 2005.

Crasson, M. (2005).
L’hypersensibilité à l’électricité: une approche multidisciplinaire pour un problème multifactoriel. Revue de la littérature.
Revue européenne de psychologie appliquée, 55, 51-67.

Crasson, M. (1998).
Le médecin généraliste et les risques pour la santé en relation avec l’environnement. Partim : “Les champs électromagnétiques de très basses fréquences”.
Université de Liège, Faculté de Médecine. 22p.

Crasson, M., Legros, J.J. (1997).
Bestaat er een verband tussen 50-60 Hz elektromagnetische velden en het risico op kanker ?
Tempo Medical, September 1997:74-86.

Crasson, M., Legros, J.J. (1997).
Existe-t-il une relation entre les champs électromagnétiques 50-60 Hz et le risque de cancer.
Tempo Medical, Septembre 1997:74-86.

Crasson, M., Timsit-Berthier, M., Legros, J-J. (1992).
Les champs électromagnétiques ont-ils un effet sur la santé ? Revue de la littérature.
Psychologie Médicale, 24 (11):1205-1215.