Provocation of electric hypersensitivity under everyday conditions

Abstract

Flodin U, Seneby A, Tegenfeldt C. Provocation of electric hypersensitivity under everyday conditions. Scand J Work Environ Heal th 2000;26(2):93-98. ObjectivesIn most previous provocation studies subjects suffering from "electric hypersensitivity" have not been able to determine correctly whether or not they have been subjected to a sham or true provocation to magnetic or electric fields. However, an often-discussed weakness is that most of the earlier provocation studies have been performed in a laboratory situation, often with simulated fields, which may not be representative of conditions prevailing in the homes or workplaces of the patients. Criticism has also been put forth about neglect of the long latency period of symptoms. Therefore, a provocation study was performed in the homes or workplaces of the patients, where we also studied the symptoms and on-off answer 24 hours after the exposure. Methods Fifteen subjects selected as having fast and distinct reactions from electric equipment were provoked on 4 occasions: mainly 2 true and 2 sham provocations. The intervals between exposure were a few or more days in order to provide the subjects with an opportunity to recover before the next provocation. A control group of healthy subjects with normal hearing and vision verified that the provocations were performed in a blind manner. Results The patients suffering from "electric hypersensitivity" were no better than the control group in deciding whether or not they were exposed to electric and magnetic fields. C O~~C~U S~O~S Exposure to electlic and magnetic fields per se does not seem to be a sufficient cause of the symptoms experienced by this patient group.Key terms double-blind provocation test, skin symptoms.Since the 1980s skin symptoms from exposure to video screens have been reported in the literature (1,2). Some provocation studies have been performed to clarify the reasons for the symptoms (3-6). In these experiments the subjects suffering from electric hypersensitivity have not been able to determine if they have been subject to fields or a sham provocation.On the other hand, Rea et a1 (7) found some subjects repeatedly experiencing neurological symptoms when exposed to electrical fields in laboratory examinations. Oftedal et a1 (8) reduced electric fields from visual display unit by using electrically conducting screen filters. Skin symptoms were less severe when the filters were active (earthed) than when they were inactive (unearthed). Stenberg et a1 (9) found that office workers in buildings with high background electric fields had a higher prevalence of skin symptoms than those in buildings with low fields. Apart from the pure electrical phenomenon, other causes of electric hypersensitivity, such as stress, neuroticism, and psychiatric morbidity, have also been discussed, but no firm associations have so far been found (10).The objection to previous provocation studies has, among other things, been that most of them have been performed in laboratory situations that may not be representative of ...

Development and evaluation of the electromagnetic hypersensitivity questionnaire

“…A 35-item symptom scale was developed by compiling symptoms published in the literature [e.g., Bergqvist and Vogel, 1997;Hillert et al, 1999Hillert et al, , 2002Flodin et al, 2000;Hietanen et al, 2002] as well as symptoms reported by EHS individuals obtained through personal communication or consultation with local action groups. For each symptom, participants were asked to rate whether they currently suffered from the symptom on a scale ranging from 0 to 4: 'not at all'(0), 'a little bit'(1), 'moderately'(2), 'quite a bit'(3), and 'a great deal'(4).…”

Hypersensitivity symptoms associated with exposure to cellular telephones: No causal link

“…However, on closer examinations of these symptomatic VDU users, no significant skin changes were observed [Berg et al, 1990;Bergqvist and Wahlberg, 1994]. Also, in double blind studies, the subjects were unable to recognize the presence of EMFs from VDUs [Hamnerius and Sjöberg, 1994;Andersson et al, 1996;Flodin et al, 2000;Lonne-Rahm et al, 2000]. Similarly, reduction of electric fields by screen filters was not found to eliminate adverse health reactions [Oftedal et al, 1999].…”

Project NEMESIS: Perception of a 50 Hz electric and magnetic field at low intensities (laboratory experiment)

“…In other double blind experiments focusing on electrical hypersensitivity syndrome related to working with computer monitors (VDU), no connection between EMF provocation and hypersensitivity reactions in the subjects was found [Hamnerius et al, 1994;Wennberg et al, 1994;Flodin et al, 2000].…”