Electromagnetic hypersensitivity

Electromagnetic hypersensitivity (EHS) - sometimes also called electrosensitivity or electrical sensitivity (ES) - is a condition in which people experience medical symptoms that they believe are caused by exposure to electromagnetic fields. Although effects of electromagnetic fields on the body are well established, to date, experimental studies have not found the symptoms of EHS to be correlated with any measurable property of the electrical environment.

Symptoms and severity

Initial reports of electromagnetic hypersensitivity in the medical literature focused on individuals who reported symptoms following work with visual display units. However, many other electrical devices have also been reported as causing symptoms and recent surveys of electromagnetic hypersensitivity sufferers have found that base stations for mobile and cordless phones, overhead power lines, electrical transformers, and mobile phone handsets are now the most commonly cited sources of ill health.

The health effects reported by electromagnetic hypersensitivity sufferers tend to be various subjective symptoms which are 'non-specific': that is, which can occur in many different illnesses or diseases. Initial Swedish and Nordic reports were mainly of facial skin effects attributed to extensive use of visual display units, such as dry eyes and burning skin.

However, recently in Europe as a whole and in the USA, a smaller group of people have reported more general and severe symptoms such as headache, fatigue, tinnitus, dizziness, memory deficits, irregular heart beat, and whole-body skin symptoms. A 2005 Health Protection Agency report noted the overlap in many sufferers with other syndromes known as symptom-based conditions, FSS (Functional Somatic Syndromes) and IEI (Idiopathic Environmental Intolerance). Levitt proposed that there may be ties between electromagnetic fields and some of these 20th century maladies, including Chronic Fatigue Syndrome, Gulf War Syndrome, and Autism.

Figures from Carlsson et al. show that over 50% of people reporting electromagnetic hypersensitivity in their study also reported multiple chemical sensitivity or similar conditions. Other authors have noted that people reporting severe electromagnetic hypersensitivity generally have these conditions or have had high levels of use of electrical equipment such as mobile phones.

Those reporting electromagnetic hypersensitivity will usually describe different levels of susceptibility to electric fields, magnetic fields and various frequencies of electromagnetic waves (including fluorescent and low-energy lights, and microwaves from mobile and cordless/portable phones), with no consistency in the severity of symptoms between sufferers. Other surveys of electromagnetic hypersensitivity sufferers have not been able to find any consistent pattern to these symptoms. Instead symptoms reflecting almost every part of the body have been attributed to electromagnetic field exposure.

A minority of people who report electromagnetic hypersensitivity claim to be severely affected by it. For instance, one survey has estimated that approximately 10% of electromagnetic hypersensitivity sufferers in Sweden were on sick leave or have taken early retirement or a disability pension, compared to 5% of the general population, while a second survey has reported that of 3046 people who experienced 'annoyance' from electrical equipment, 340 (11%) reported 'much' annoyance. For those who report being severely affected, their symptoms can have a significant impact on their quality of life; with sufferers reporting physical, mental and social impairment and psychological distress.

Prevalence

A questionnaire survey of 2,072 people in California found that the prevalence of claimed electromagnetic hypersensitivity within the sample group was 3.24% (95% CI 2.8–3.68%), with electromagnetic hypersensitivity being defined as "being allergic or very sensitive to getting near electrical appliances, computers, or power lines" (response rate 58.3%).

A similar questionnaire survey from the same year in Stockholm County (Sweden), found a 1.5% prevalence of electromagnetic hypersensitivity within the sample group, with electromagnetic hypersensitivity being defined as "hypersensitivity or allergy to electric or magnetic fields" (response rate 73%).

A more recent survey of prevalence of 'annoyance' relating to visual display units, fluorescent tube lighting, and other electrical equipment within the general Swedish population reported the prevalence of 'much annoyance' relating to these devices to be 0.8%, 1.4%, and 0.4% respectively.

A group of scientists also attempted to estimate the number of people reporting "subjective symptoms" from electromagnetic fields for the European Commission. The group reported that estimates of the total number of cases differed substantially between countries as well as between the answering groups, with self aid group (SAG) estimates consistently around ten times higher than those of centres of occupational medicine (COM). Estimates ranged from less than a few cases per million of the population (COM estimates from UK, Italy, and France) to a few tenths of a percent of the population (SAG estimates in Denmark, Ireland, and Sweden). The group concluded that the differences in prevalence were at least partly due to the differences in available information and media attention around electromagnetic hypersensitivity that exist in different countries. Similar views have been expressed by other commentators.

Etiology and evidence

By definition, individuals who report electromagnetic hypersensitivity believe that electromagnetic fields from common electrical devices can trigger or exacerbate their symptoms. However, as these fields tend to be much weaker than the exposure levels generally accepted to cause physiological effects, the role that electromagnetic fields play in the etiology of the condition has been the topic of much controversy: sufferers and their support groups are firmly convinced of a causal relationship with electromagnetic fields; whereas at present the scientific literature does not support such a link. Some professionals consider electromagnetic hypersensitivity to be a real physical condition for which the cause is unclear, while others consider it to be a psychosomatic illness. Some sufferers and support groups argue that the situation has become politicised to the extent that the outcomes of studies might have been influenced by the widespread implications that acceptance of such a connection would have on future policy.

In 2005, a systematic review was published which looked at the results of 31 experiments testing the role of electromagnetic fields in causing ES. Each of these experiments exposed people who reported electromagnetic hypersensitivity to genuine and sham electromagnetic fields under single- or double-blind conditions. The review concluded that:

"The symptoms described by 'electromagnetic hypersensitivity' sufferers can be severe and are sometimes disabling. However, it has proved difficult to show under blind conditions that exposure to electromagnetic fields can trigger these symptoms. This suggests that 'electromagnetic hypersensitivity' is unrelated to the presence of electromagnetic fields, although more research into this phenomenon is required."

Since then, several more double-blind experiments have been published, each of which has suggested that people who report electromagnetic hypersensitivity are unable to detect the presence of electromagnetic fields and are as likely to report ill health following a sham or nocebo exposure, as they are following exposure to genuine electromagnetic fields.

The Essex study has received some criticism for its methodology and analysis, and the authors have responded in full to these initial criticisms. Following this study, it was reported in the press that the evidence from provocation studies indicate that electromagnetic fields "do not cause the symptoms".

A 2005 report by the UK Health Protection Agency concluded that electromagnetic hypersensitivity needs to be considered in ways other than its etiology; that is, the suffering is real, even if the underlying cause is not thought to be related to electromagnetic fields. They also wrote that considering only whether electromagnetic radiation was a causative factor was not meeting the needs of sufferers, although continued research on etiology was essential.

Debate over the cause

It has been a matter of controversy whether electromagnetic field exposure causes sufferers' symptoms, and the balance of evidence from provocation studies so far indicates that the link is false. In a 2005 review of the literature regarding whether sufferers are genuinely affected by electromagnetic fields, seven studies were found which did report an association, while 24 could not find any association with electromagnetic fields. However, of the seven 'positive' studies, two could not be replicated even by the original authors, three had serious methodological shortcomings, and the final two presented contradictory results.

There are currently over thirty support groups across the world for people reporting electromagnetic hypersensitivity, and many of these are convinced that there is a link between reports of electromagnetic hypersensitivity and electromagnetic fields.

Disagreement over this continued in 2002, as shown by the Freiburger Appeal; a petition originated by the German environmental medical lobby group IGUMED stating that "we can see a clear temporal and spatial exposure between the appearance of [certain] disease and exposure to pulsed high-frequency microwave radiation", and demanding radical restrictions on mobile phone use. However, the World Health Organization concluded in 2005 that there is no known scientific basis for the belief that electromagnetic hypersensitivity is caused by exposure to electromagnetic fields.

Possible treatment and symptom alleviation

No physical treatments currently exist, as the origin of the symptoms is usually ascribed to either classical conditioning or mistaken self-diagnosis. The symptoms are often assumed to have causes that are psychological in nature or to be caused by some other illness that has not yet been treated. Note that the existence of the symptoms is not questioned.

Those that feel that they genuinely are sensitive to electromagnetic fields generally try to reduce their exposure to electromagnetic sources as much as is practical, but complete avoidance presents major practical difficulties in modern society. Other methods often used by sufferers include screening or shielding (such as earthed/grounded metallic netting or paints), electrical filters, and treatment of underlying conditions, often using complementary and alternative therapy.

A 2006 systematic review identified nine clinical trials testing different treatments for ES: four studies tested cognitive behavioural therapy, two tested visual display unit filters, one tested a device emitting 'shielding' electromagnetic fields, one tested acupuncture, and one tested daily intake of tablets containing vitamin C, vitamin E, and selenium. The authors of the review concluded that:

"The evidence base concerning treatment options for electromagnetic hypersensitivity is limited and more research is needed before any definitive clinical recommendations can be made. However, the best evidence currently available suggests that cognitive behavioural therapy is effective for patients who report being hypersensitive to weak electromagnetic fields."

See also

• Electromagnetic radiation and health
• Mobile phone radiation and health
• Wireless electronic devices and health

Further reading

• Katajainen, Jyrki (1995). Electromagnetic hypersensitivity : 2nd Copenhagen Conference, Copenhagen, Denmark, May 1995 : proceedings. Randers, Denmark: Danish Association for the Electromagnetically Hypersensitive. ISBN 8798127020. OCLC 37386169. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)

External links

• ElectroSensitivity.Org – Information, Advice & Awareness of Electrosensitivity
• Belgian BioElectroMagnetic Group – Information about electrosensitivity