Psychological Medicine and Psychiatry /

General Hospital Psychiatry
Mobile Phone Research Unit

The Mobile Phone Research Unit examines the possible short-term health effects of mobile phone type signals.

Researchers working in the Unit want to find out if some people are highly sensitive to these signals, and have previously tested whether those people who report sensitivity to mobile phone emissions experience adverse symptoms when exposed to them under ‘double-blind’ conditions (paper). The research team is now investigating whether exposure to signals affects hormone levels and is conducting a new study to test whether the UK police radio system causes adverse health effects for some police officers.

The Unit is also interested in the more general area of electrosensitivity and has published two extensive reviews of the scientific literature concerning this poorly understood condition.

The work is supported by two research grants awarded by the UK Mobile Telecommunications and Health Research programme.

Mobile Phone Research Unit
New Medical School Building
Bessemer Road
London SE5 9PJ

Contact: Dr James Rubin
Email: g.rubin@iop.kcl.ac.uk
Phone: 020 3299 3798

What is electrosensitivity?

Electrosensitivity is a term used to describe a condition in which people report adverse sensations that they believe are caused by exposure to weak electromagnetic fields. Other terms sometimes used to describe this condition include electromagnetic hypersensitivity and electrical sensitivity.

In the 1980s and early 1990s, most cases of electrosensitivity included symptoms such as itching sensations or dry skin that were attributed to working in front of a visual display unit. More recently, surveys of people who report electrosensitivity have found that different sufferers can describe symptoms in connection with a wide range of different devices, including computers, mobile phones, power lines, televisions, fluorescent lighting, microwave ovens, cordless telephones and mobile phone masts (1-3).

The health effects reported by electrosensitivity sufferers are very diverse and can differ markedly from person to person: from headaches; to fatigue; to concentration problems; to digestive discomfort (1-5). Several studies have attempted to see if there is any pattern to these symptoms, that is, whether a specific electrosensitivity ‘syndrome’ can be found. To date, no such pattern has been identified (1;2;5;6).

The speed with which symptoms are said to appear following exposure to an electrical device also differs between sufferers. In one survey of nearly 400 people who reported electrosensitivity, most sufferers said that their symptoms came on quickly following exposure: 53 per cent tended to notice symptoms within a few minutes and 21 per cent within a few hours (2). A minority (17 per cent) reported that symptoms generally took several days to develop.

How common is electrosensitivity?

Reports of electrosensitivity have increased dramatically in Britain over recent years. In 1997, a report for the European Commission concluded that the condition hardly existed at all in the United Kingdom (7). Ten years later, a questionnaire survey by the University of Essex found that 4 per cent of people from the Colchester area fit the profile of someone with electrosensitivity (1).

Recent estimates of the prevalence of electrosensitivity vary from country to country. The following estimates are all based on the results of telephone or questionnaire surveys and represent the approximate percentage of people in that country who believe that they are particularly sensitive to electromagnetic fields.

Sweden: 1.5 per cent (5)
California: 3.2 per cent (8)
UK: 4 per cent (1)
Switzerland: 5 per cent (3)
Germany: 8 per cent (Infas, 2003, cited in (3)).

Why do some nations seem to experience higher rates of electrosensitivity than others? One explanation is that higher levels of media attention on ‘electrosmog’ in particular countries make it more likely that people will diagnose themselves as having electrosensitivity (9). Another reason may be that the different surveys have tended to word their questions in slightly different ways, something that may affect their results.

How severe is electrosensitivity?

For some people, electrosensitivity has a major impact on their lives, affecting their ability to work, to socialise and to maintain a normal family life. Some sufferers have felt the need to leave their homes in towns or cities and move to isolated rural locations in order to escape from electromagnetic fields. Others have spent large sums of money purchasing specialist screening materials in an attempt to reduce the levels of electromagnetic fields in their houses. For other people, the condition is less problematic.

There is relatively little information relating to the proportion of sufferers who might be considered severely affected by electrosensitivity. Early estimates were that about 10 per cent of sufferers could be categorised as ‘severe’ cases (7). More recent studies have been roughly in line with this estimate. In particular, a survey of Californian residents found that while 32 people per 1,000 reported having electrosensitivity, only 5 people per 1,000 reported electrosensitivity associated with the need to change job or to remain unemployed (16 per cent of sufferers) (8). Another survey, this time of a Swedish sample, found that of 3,046 people who reported ‘annoyance’ from electrical equipment, 340 (11 per cent) reported ‘much annoyance’ (10).

Is electrosensitivity caused by exposure to electromagnetic fields?

The type of electromagnetic fields that seem to cause problems for electrosensitivity sufferers are typically far weaker than those generally accepted as causing adverse health effects. As such, there has been a considerable amount of controversy as to whether electromagnetic fields really do trigger the symptoms of electrosensitivity.

The best way to test this issue is using an ‘experimental provocation study.’ In this type of study, an electrosensitive volunteer is exposed to two things: a real electromagnetic field which is the same, or very similar, to the type of field they report being sensitive to, and a sham condition in which no electromagnetic fields are presented. In a ‘single blind’ provocation study, the volunteer is not told which session is which. In a ‘double blind’ study, the researchers carrying out the testing are also unaware of which session is which. The volunteer’s task is to say which session they think involved the real exposure, and to report whether they experienced more symptoms in one session than another. For other forms of allergy or sensitivity, such as food allergies, double-blind provocation studies are considered the ‘gold standard’ method of diagnosis (11).

In a review paper published in 2005, the Mobile Phone Research Unit team reported that 31 blind or double-blind provocation studies had previously been conducted for electrosensitivity (12). Of these, 24 studies found no evidence that people reacted differently to real electromagnetic fields compared to sham sessions. Seven studies did find some evidence of different effects. However, for two of these studies, the same research teams subsequently tried and failed to replicate their own findings. In three more, there were important statistical problems with the studies that cast doubt on their findings. The final two studies gave results that contradicted each other – one reported that the real exposure made people’s moods worse, the other reported that real exposure made people’s moods better. The conclusion of the review was that despite numerous studies having examined the issue, there was no robust evidence to support the theory that weak electromagnetic fields trigger symptoms in people who report being electrosensitive. More research into the phenomenon would be useful.

Since that review came out, six more provocation studies have been published, including one carried out by the Mobile Phone Research Unit (6;13-17). These have all reported the same finding: people with electrosensitivity do not react any differently to genuine electromagnetic fields compared to sham testing sessions.

What else might cause electrosensitivity?

If electromagnetic fields do not cause electrosensitivity, what does? It may be that there is no single answer to this. For some people, it is possible that they have some other biomedical or psychiatric condition that is causing them to feel unwell. For example, in three clinical trials of treatments for electrosensitivity, between 14 per cent and 33 cent of potential volunteers had to be excluded after careful examination revealed the presence of another illness which might have explained their symptoms (18-20). Similarly, one survey of electrosensitivity sufferers in the UK noted that almost 40 per cent reported also suffering from a chronic illness which might partly account for their ill health (1).

For other individuals, it is possible that psychological factors play a role in causing their symptoms. For instance, there is good evidence that people can involuntarily ‘learn’ to associate real physical symptoms with an innocuous substance (20). Once this learning has taken place, the symptoms can then re-occur every time that stimulus is encountered.

What treatments are there for electrosensitivity?

Surveys into what actions people with electrosensitivity take to manage their illness suggest that many try to avoid situations in which they might be exposed to electromagnetic fields. This might involve the use of special netting over their beds, for example, or the removal of electrical equipment from their homes or workplaces. Often these techniques are reported to be quite helpful (2). These techniques do not necessarily work because they reduce electromagnetic fields, however. In fact, two good quality studies from the 1990’s examined this issue in some detail (22;23). People who described being sensitive to their computer monitors at work were given special screen filters to place on them. These filters were designed to cut the emissions coming from the monitors and stayed in place for several weeks in one study, and several months in the other. The filters proved to be quite effective and people’s symptoms were significantly less pronounced after they had been fitted. However, this effect was just as impressive when the researchers swapped the real filters for others that looked identical, but were actually inactive. The impressive effects were not to do with reducing the electromagnetic fields, but seemed to be a placebo effect. Believing that electromagnetic fields have been reduced may be more important than actually reducing them.

Seven other clinical trials have tested other possible treatments for electrosensitivity, including: acupuncture; special electrical screening devices; vitamin supplements; and cognitive behavioural therapy (24). Of these, the only option that appears to show any promise is cognitive behavioural therapy – a ‘talking therapy’ designed to help patients examine other possible reasons why they might be experiencing symptoms and to find new ways of coping with their illness. Unfortunately, most of these studies have had methodological short-comings. More research into treatments for electrosensitivity is needed.

Mobile Phone Research Unit Publications

Rubin GJ, Cleare AJ, Wessely S. Psychological factors associated with self-reported sensitivity to mobile phones. Journal of Psychosomatic Research 2007; e-publication ahead of print DOI:10.1016/j.jpsychores.2007.05.006. (abstract)

Das-Munshi J, Rubin GJ, Wessely S. Multiple chemical sensitivites: Review. Current Opinion in Otolaryngology & Head and Neck Surgery 2007; 15:274-280. (abstract)

Rubin GJ, Hahn G, Everitt B, Cleare AJ, Wessely S. Are some people sensitive to mobile phone signals? A within-participants, double-blind, randomised provocation study. British Medical Journal 2006; 332:886-889. (paper)

Das Munshi J, Rubin GJ, Wessely S. Multiple chemical sensitivities: A systematic review of provocation studies. Journal of Allergy and Clinical Immunology 2006; 118:1257-1264. (abstract)

Rubin G, Das Munshi J, Wessely S. A systematic review of treatments for electromagnetic hypersensitivity. Psychotherapy and Psychosomatics 2006; 75:12-18. (abstract)

Rubin GJ, Das Munshi J, Wessely S. Electromagnetic hypersensitivity: A systematic review of provocation studies. Psychosomatic Medicine 2005; 67:224-232. (abstract)

Useful links

University of Essex Study into the effects of TETRA on measures of health

The Mobile Telecommunications and Health Research Programme

The World Health Organisation’s factsheet on Electrosensitivity

The Health Protection Agency’s report on Electrosensitivity

References

1. Eltiti S, Wallace D, Zougkou K, Russo R, Joseph S, Rasor P et al. Development and evaluation of the electromagnetic hypersensitivity questionnaire. Bioelectromagnetics 2007; 28:137-151.

2. Roosli M, Moser M, Baldinini Y, Meier M, Braun-Fahrlander C. Symptoms of ill health ascribed to electromagnetic field exposure – a questionnaire survey. Int J Hyg Environ Health 2004; 207:141-150.

3. Schreier N, Huss A, Roosli M. The prevalence of symptoms attributed to electromagnetic field exposure: A cross-sectional representative survey in Switzerland. Soz Praventivmed 2006; 51:202-209.

4. Schuz J, Petters C, Egle UT, Jansen B, Kimbel R, Letzel S et al. The "Mainzer EMF-Wachhund": Results from a watchdog project on self-reported health complaints attributed to exposure to electromagnetic fields. Bioelectromagnetics 2006; 27:280-287.

5. Hillert L, Berglind N, Arnetz BB, Bellander T. Prevalence of self-reported hypersensitivity to electric or magnetic fields in a population-based questionnaire survey. Scand J Work Environ Health 2002; 28(1):33-41.

6. Frick U, Kharraz A, Hauser S, Wiegand R, Rehm J, von Kovatsits U et al. Comparison perception of singular transcranial magnetic stimuli by subjectively electrosensitive subjects and general population controls. Bioelectromagnetics 2005; 26:287-298.

7. Bergqvist UO, Vogel E, Aringerl L, Cunningham J, Gobba F, Leitgeb N et al. Possible health implications of subjective symptoms and electromagnetic fields; A report by a European group of experts for the European Commission, DG V. Arbete och Halsa 1997; 19:1-45.

8. Levallois P, Neutra R, Lee G, Hristova L. Study of self-reported hypersensitivity to electromagnetic fields in California. Environ Health Perspect 2002; 110 Suppl 4:619-623.

9. Irvine N. Definition, Epidemiology and Management of Electrical Sensitivity. Report for the Radiation Protection Division of the Health Protection Agency. Didcot, Oxfordshire: Health Protection Agency; 2005.

10. Carlsson F, Karlson B, Orbaek P, Osterberg K, Ostergren P-O. Prevalence of annoyance attributed to electrical equipment and smells in a Swedish population, and relationship with subjective health and daily functioning. Public Health 2005; 119:568-577.

11. Beyer K, Teuber SS. Food allergy diagnostics: scientific and unproven procedures. Cur Op Allergy Clin Immun 2005; 5:261-266.

12. Rubin GJ, Das Munshi J, Wessely S. Electromagnetic hypersensitivity: A systematic review of provocation studies. Psychosom Med 2005; 67:224-232.

13. Wilen J, Johansson A, Kalezic N, Lyskov E, Sandstrom M. Psychophysiological tests and provocation of subjects with mobile phone related symptoms. Bioelectromagnetics 2006; 23:204-214.

14. Regel SJ, Negovetic S, Roosli M, Berdinas V, Schuderer J, Huss A et al. UMTS base station-like exposure, well being and cognitive performance. Environ Health Perspect 2006; 114(8):1270-1275.

15. Wenzel F, Reibenweber J, David E. Cutaneous microcirculation is not altered by a weak 50Hz magnetic field. Biomed Tech (Berl) 2005; 50:14-18.

16. Rubin GJ, Hahn G, Everitt B, Cleare AJ, Wessely S. Are some people sensitive to mobile phone signals? A within-participants, double-blind, randomised provocation study. BMJ 2006; 332:886-889.

17. Oftedal G, Straume A, Johnsson A, Stovner LJ. Mobile phone headache: a double-blind, sham-controlled provocation study. Cephalalgia 2007; 27:447-455.

18. Andersson B, Berg M, Arnetz BB, Melin L, Langlet I, Liden S. A cognitive-behavioral treatment of patients suffering from ’electric hypersensitivity’: Subjective effects and reactions in a double-blind provocation study. J Occup Environ Med 1996; 38(8):752-758.

19. Hillert L, Hedman BK, Dolling BF, Arnetz BB. Cognitive behavioural therapy for patients with electric sensitivity – a multidisciplinary approach in a controlled study. Psychother.Psychosom. 1998;67:302-10.

20. Hillert L, Kolmodin-Hedman B, Eneroth P, Arnetz BB. The effect of supplementary antioxidant therapy in patients who report hypersensitivity to electricity: a randomized controlled trial. Medgenmed [Computer File]: Medscape General Medicine 2001; 3(2):11.

21. Van den Bergh O, Winters W, Van Diest I. Learning subjective health complaints. Scand J Psychol 2002; 43:147-152.

22. Oftedal G, Nyvang A, Moen BE. Long-term effects on symptoms by reducing electric fields from visual display units. Scand J Work Environ Health 1999; 25(5):415-421.

23. Oftedal G, Vistnes AI, Rygge K. Skin symptoms after the reduction of electric fields from visual display units. Scand J Work Environ Health 1995; 21(5):335-344.

24. Rubin G, Das Munshi J, Wessely S. A systematic review of treatments for electromagnetic hypersensitivity.Psychother Psychosom 2006; 75:12-18.