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Electromagnetic hypersensitivity (EHS) is a claimed sensitivity to electromagnetic fields, resulting in negative symptoms. EHS has no scientific basis and is not a recognised medical diagnosis. Claims are characterized by a "variety of non-specific symptoms, which afflicted individuals attribute to exposure to electromagnetic fields".
Contents
Those who are self-described with EHS report adverse reactions to electromagnetic fields at intensities well below the maximum levels permitted by international radiation safety standards. The majority of provocation trials to date have found that such claimants are unable to distinguish between exposure and non-exposure to electromagnetic fields. A systematic review in 2005 showed no convincing scientific evidence for symptoms being caused by electromagnetic fields. Since then several double-blind experiments have shown 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 exposure as they are following exposure to genuine electromagnetic fields, suggesting the cause in these cases to be the nocebo effect.
A 2005 review by the UK Health Protection Agency and a 2006 systematic review each evaluated the evidence for various medical, psychological, behavioral, and alternative treatments for EHS and each found that the evidence-base was limited and not generalizable, but that the best evidence favored cognitive behavioural therapy. As of 2005, WHO recommended that people presenting with claims of EHS be evaluated to determine if they have a medical condition that may be causing the symptoms the person is attributing to EHS, that they have a psychological evaluation, and that the person's environment be evaluated for issues like air or noise pollution that may be causing problems.
Some people who feel they are sensitive to electromagnetic fields may seek to reduce their exposure or use alternative medicine. Government agencies have enforced false advertising claims against companies selling devices to shield against EM radiation.
Signs and symptoms
There are no specific symptoms associated with claims of EHS and reported symptoms range widely between individuals. They include headache, fatigue, stress, sleep disturbances, skin prickling, burning sensations and rashes, pain and ache in muscles and many other health problems. In severe cases such symptoms can be a real and sometimes disabling problem for the affected person, causing psychological distress. There is no scientific basis to link such symptoms to electromagnetic field exposure.
The prevalence of some reported symptoms is geographically or culturally dependent and does not imply "a causal relationship between symptoms and attributed exposure". Many such reported symptoms overlap with other syndromes known as symptom-based conditions, functional somatic syndromes, and IEI (idiopathic environmental intolerance).
Those reporting electromagnetic hypersensitivity will usually describe different levels of susceptibility to electric fields, magnetic fields, and various frequencies of electromagnetic waves. Devices implicated include fluorescent and low-energy lights, mobile, cordless/portable phones, and WiFi. A 2001 survey found that people self-diagnosing as EHS related their symptoms most frequently to mobile phone base stations (74%), followed by mobile phones (36%), cordless phones (29%), and power lines (27%). Surveys of electromagnetic hypersensitivity sufferers have not been able to find any consistent pattern to these symptoms.
Causes
Most blinded conscious provocation studies have failed to show a correlation between exposure and symptoms, leading to the suggestion that psychological mechanisms play a role in causing or exacerbating EHS symptoms. In 2010 Rubin et al. published a follow-up to their 2005 review, bringing the totals to 46 double-blind experiments and 1175 individuals with self-diagnosed hypersensitivity. Both reviews found no robust evidence to support the hypothesis that electromagnetic exposure causes EHS, as have other studies. They also concluded that the studies supported the role of the nocebo effect in triggering acute symptoms in those with EHS. The Essex provocation study of 2007 received some criticism for its methodology and analysis. In their response the authors noted that their study says nothing about long-term effects, but that those affected often claim to respond to the fields within a few minutes.
Some other types of studies suggest evidence for symptoms at non-thermal levels of electromagnetic exposure. A review in 2010 of ten studies on neurobehavioral and cancer outcomes near cell phone base stations found eight with increased prevalence, including sleep disturbance and headaches. Since 1962 the microwave auditory effect or tinnitus has been shown from radio frequency exposure at levels below significant heating. Studies during the 1960s in Europe and Russia claimed to show effects on humans, especially the nervous system, from low energy RF radiation; the studies were disputed at the time.
Other studies on sensitivity have looked at therapeutic procedures using non-thermal electromagnetic exposure, genetic factors, an alteration in mast cells, oxidative stress, protein expression and voltage-gated calcium channels. Mercury release from dental amalgam and heavy metal toxicity have also been implicated in exposure effects and symptoms. Another line of study has been the nature of hyper-sensitivity or intolerance and the range of environmental exposures which may be related to it. Some 80% of people with self-diagnosed electromagnetic intolerance also claim intolerance to low levels of chemical exposure.
Diagnosis
Electromagnetic hypersensitivity is not an accepted diagnosis; medically there is no case definition or clinical practice guideline and there is no specific test to identify it, nor is there an agreed-upon definition with which to conduct clinical research.
Complaints of electromagnetic hypersensitivity may mask organic or psychiatric illness. Diagnosis of those underlying conditions involves investigating and identifying possible known medical causes of any symptoms observed. It may require both a thorough medical evaluation to identify and treat any specific conditions that may be responsible for the symptoms, and a psychological evaluation to identify alternative psychiatric/psychological conditions that may be responsible or contribute to the symptoms.
Symptoms may also be brought on by imagining that exposure is causing harm, an example of the nocebo effect. Studies have shown that reports of symptoms are more closely associated with belief that one is being exposed than with any actual exposure.
Management
A 2006 systematic review and a 2005 review by the UK Health Protection Agency each evaluated the evidence for various medical, psychological, behavioral, and alternative treatments for EHS and each found that the evidence-base was limited and not generalizable. The conclusion of the 2006 review stated: "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."
As of 2005 WHO recommended that people presenting with claims of EHS be evaluated to determine if they have a medical condition that may be causing the symptoms the person is attributing to EHS, that they have a psychological evaluation, and that the person's environment be evaluated for issues like air or noise pollution that may be causing problems.
In 2007 Scientific skeptic author Brian Dunning investigated the literature on the subject and concluded that "The ability of a human brain to convince itself of just about anything is not to be underestimated. If you believe yourself to be electrosensitive, then you will be, quite literally, whenever you (think that you) perceive the presence of electromagnetism... you will actually suffer measurable physical symptoms and can potentially become acutely ill."
Prevalence
The prevalence of claimed electromagnetic hypersensitivity has been estimated as being between a few cases per million to 5% of the population depending on the location and definition of the condition.
In 2002, a questionnaire survey of 2,072 people in California found that the prevalence of self-reported electromagnetic hypersensitivity within the sample group was 3% (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 self-reported electromagnetic hypersensitivity within the sample group, with electromagnetic hypersensitivity being defined as "hypersensitivity or allergy to electric or magnetic fields" (response rate 73%).
A 2004 survey in Switzerland found a 5% prevalence of claimed electromagnetic hypersensitivity in the sample group of 2,048.
In 2007, a UK survey aimed at a randomly selected group of 20,000 people found a prevalence of 4% for symptoms self-attributed to electromagnetic exposure.
A group of scientists also attempted to estimate the number of people reporting "subjective symptoms" from electromagnetic fields for the European Commission. In the words of a HPA review, they 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."
Society and culture
In 2010 a cell tower operator revealed at a public meeting that the tower that nearby residents were blaming for their EHS symptoms had been turned off over six weeks prior to the meeting.
In February 2014 the UK Advertising Standards Authority found that claims of harm from electromagnetic radiation, made in a product an advertisement, were unsubstantiated and misleading.
People have filed lawsuits to try to win damages due to harm claimed from electromagnetic radiation. In 2012 a New Mexico judge dismissed a lawsuit in which one person sued his neighbor, claiming to have been harmed by EM radiation from his neighbor's cordless telephones, dimmer switches, chargers, Wi-Fi and other devices. The plaintiff brought the testimony of his doctor, who also believed she had EHS, and a person who represented himself as a neurotoxicologist; the judge found none of their testimony credible. In 2015 parents of a boy at a school in Southborough, Massachusetts alleged that the school's wi-fi was making the boy sick.
In November 2015 a depressed teenaged girl in England committed suicide; she had complained about EHS and after her death her suicide was attributed to EHS by tabloids and taken up by EHS advocates.
Self-treatment
Some people who feel they are sensitive to electromagnetic fields self-treat by trying to reduce their exposure to electromagnetic sources by avoiding sources of exposure, disconnecting or removing electrical devices, shielding or screening of self or residence, and complementary and alternative therapy.
The United States National Radio Quiet Zone offers an environment where wireless signals are restricted.