Table 2.

Experimental studies on IEI-EMF

Reference	Study design	Recruitment	Type of sensitivity	IEI-EMF sample characteristics	Identifying criteria for IEI-EMF	Main exclusion criteria	Identification/Case definition methods for IEI-EMF
Rea et al., 1991 (USA) [28].	Provocation	Voluntary participation.	General	N = 100.	Self-reported sensitivity to EMF.	N.R/E.	Subjective report, medical examination.
Hamnerius et al., 1993(Sweden) [29].	Provocation	IEI-EMF subjects referred to a health care service/institution.	VDU-specific	N = 30.	Report of “distinctive” symptoms, occurrence of the symptoms within an hour from being exposed to VDU and disappearance or substantial reduction within a few hours after exposure termination.	Somatic or psychiatric disorder that could account for the reported symptomatology.	Subjective report, medical, psychiatric & psychological examination.
Arnetz et al., 1995 (Sweden) [30].	Intervention	IEI-EMF subjects referred to a health care service/institution.	General	N = 20, m.a = 45, f.g = 75%.	Report of symptoms attributed to EMF exposure.	Somatic or psychiatric disorder that could account for the reported symptomatology.	Subjective report, medical & psychiatric examination.
Andersson et al., 1996 (Sweden) [31].	Provocation	IEI-EMF subjects referred to a health care service/institution.	General	N = 17, m.a = 41.7, f.g = 70.6%.	Experience of “typical” symptoms of “electric hypersensitivity” when being in an “electrical environment”, duration of at least 6 months, limitations in daily functioning, experience of symptomatology within less than 30 minutes after exposure to electric equipment under experimental testing.	Somatic or psychiatric disorder that could account for the reported symptomatology.	Subjective report, medical & psychiatric examination.
Bertoft et al., 1996 (Sweden) [32].	Provocation	Voluntary participation of IEI-EMF subjects.	General	N = 5, a.r = 46-60, f.g = 80%.	Self-reported hypersensitivity to EMF.	N.R/E.	Subjective report.
Toomingas, 1996 (Sweden) [33].	Provocation (case study)	Voluntary participation of a medical patient.	General	N = 1 male, age = 35.	Fear of a negative impact of health caused by EMF exposure, report of symptoms attributed to EMF such as fatigue, headache, lack of concentration, numbness & paresthesia in the arms, greasy feeling in the palms, inability to work due to the reported symptoms.	N.R/E.	Subjective report, medical & neurological examination.
Sandström et al., 1997 (Sweden) [34].	Provocation	IEI-EMF subjects treated to a health care service/institution.	VDT & fluorescent light-specific	N = 10, m.a = 47, f.g = 70%.	Self-report of a combination of skin (mucous), eye & neurological symptoms, attribution of these symptoms to EMF emitted from VDT work, fluorescent light or TV.	Somatic or psychiatric diseases severe enough to require medical treatment.	Subjective report, medical examination.
Hillert et al., 1998 (Sweden) [35].	Intervention	IEI-EMF subjects referred to a health care service/institution.	General	N = 10, m.a = 40, f.g = 60%.	Self-reported hypersensitivity to EMF, age between 18–65 y.o, being employed for at least 1 week during the past 3 months, symptoms had to show some variation due to perceived exposure to EMF or proximity to relative equipment.	Medical or mental disorder that could account for the reported symptomatology, long period of sick leave, unemployment.	Subjective report, medical examination.
Trimmel et al., 1998 (Austria) [36].	Provocation	Voluntary participation.	General	N = 36, a.r = 18-36.	Individual belief of an “exceptional reaction to EMF”, a score of >50 on a continuous rating scale between 0–100.	N.R/E.	Subjective report.
Flodin et al., 2000 (Sweden) [37].	Provocation	IEI-EMF subjects who were members of a relative self-group or registered to a health care service/institution.	General	N = 15, m.a = 48.3, f.g = 73.3.	Attribution of symptoms to named EMF sources, mean reaction should occur within 60 minutes of exposure, there was no experience of symptoms at home or workplace when the subject was considered as “unexposed”, symptoms should disappear within a few days after exposure.	Slow reaction or denial for participation because of symptom severity, undergoing treatment for medical conditions.	Subjective report, medical examination (registered IEI-EMF subjects).
Lohne-Rahm et al., 2000 (Sweden) [38].	Provocation	Voluntary participation after description of the study in newspaper advertisements or IEI-EMF subjects referred to a health care service/institution.	General	N = 12.	Report of skin symptoms during a 30-minute exposure to EMF & symptom duration of at least 6 months.	Diagnosed skin diseases, slow, excessive or no reactions during the experiment.	Subjective report, medical examination (referred IEI-EMF subjects).
Hillert et al., 2001 (Sweden) [39].	Intervention	IEI-EMF subjects referred to a health care service/institution.	General	N = 16, m.a = 39.5, f.g = 81.3%.	Self-reported hypersensitivity to electricity, experience of change in symptoms within 24 hours after a perceived change in exposure to EMF, a history of VDU or fluorescent lights as the initial triggering factors.	Somatic or psychological disorder that could account for the reported symptomatology.	Subjective report, medical & psychological examination.
Lyskov et al., 2001 (Sweden) [40].	Provocation	IEI-EMF subjects referred to a health care service/institution.	General	N = 20, m.a = 45.8, f.g = 75%.	Self-reported hypersensitivity to EMF	N.R/E.	Subjective report, medical examination.
Hietanen et al., 2002 (Finland) [41].	Provocation	Voluntary participation.	General	N = 20, m.a = 49, f.g = 65%.	Self-reported hypersensitivity to EMF, experience of symptoms during a 30-minute (provocation) test period.	N.R/E.	Subjective report, medical examination.
Hillert et al., 2002 (Sweden) [42].	Intervention	IEI-EMF subjects referred to a health care service/institution.	General	N = 22, m.a = 42, f.g = 64%.	Report of symptoms assumed to be caused by sensitivity to EMF.	Medical or psychological condition that could account for the symptoms.	Subjective report, medical & psychiatric examination.
Mueller et al., 2002 (Switzerland) [43].	Provocation	Voluntary participation.	General	N = 63, m.a = 49.5, f.g = 51%.	Self-reported sensitivity to EMF or “Electrical Hypersensitivity Syndrome (EHS)”.	N.R/E.	Subjective report.
Leitgeb et al., 2003(Austria) [44].	Provocation	Randomly selected sample from general population (N = 708).	General	a.r = 17-60.	Increased levels of “electrosensibility”, defined as the individual ability to perceive electric or electromagnetic exposures without necessarily developing health symptoms.	N.R/E.	Measurement of EMF perception thresholds.
Österberg et al., 2004 (Sweden) [45].	Provocation	Randomly selected sample from general population (N = 13381), based on Östergren et al. (report) [46].	General	N = 16, m.a = 41.8, f.g = 50%.	Individual experience the past 2 weeks of “very much” physiologic “annoyance” attributed to FTL, and/or VDU and/or other electrical equipment.	Report of long-term sick leave, disability pension, subjects diagnosed with severe medical condition that required medication (e.g. diabetes), age of >58 y.o	Subjective report, medical examination.
Belyaev et al., 2005 (Sweden) [47].	Provocation	Voluntary participation.	General	N = 7, m.a = 44.8, f.g = 71.5%.	Self-reported hypersensitivity to EMF.	Smoking, regular medication	Subjective report.
Frick et al., 2005 (Germany) [48].	Provocation	Voluntary participation after description of the study in a local newspaper.	General	N = 30, m.a = 41.7, f.g = 77%.	Self-reported hypersensitivity to named EMF sources, attribution of severe symptoms that limited daily functioning & age between 18–64 y.o.	Not complaining or not experiencing limitations to daily living due to the reported symptomatology.	Subjective report.
Wenzel et al., 2005 (Germany) [49].	Provocation	Voluntary participation.	VDU & powerline-specific	N = 3 male subjects, m.a = 37.	Concern about the effects of EMF exposure, report of various symptoms attributed to VDU and/or powerlines, abstinence from smoking.	N.R/E.	Subjective report.
Regel et al., 2006 (Switzerland) [50].	Provocation	Voluntary participation after description of the study in advertisements in a local newspaper, flyers & use of databases of two previous studies with IEI-EMF subjects willing to participate in future research projects.	Base station-specific	N = 33, m.a = 37.7, f.g = 57.5%.	Self-reported sensitivity to EMF emitted by mobile or cordless phones & antennas.	Regular consumption of narcotics or psychoactive drugs in the last 6 months, smoking, diagnosed with a chronic disease, pregnancy, medical history of head injuries, neurologic/psychiatric diseases, sleep disturbances, average alcohol consumption of >10 drinks per week, average consumption of caffeinated beverages amounting to >450 milligrams caffeine per day, shift workers, undertaking long-haul flights of >3 hours time zone difference within the last month.	Subjective report.
Rubin et al., 2006 (UK) [51].	Provocation	Through mailshots organised by an IEI-EMF support group, advertisements & articles in health care institutions & practices.	MP-specific	N = 71, m.a = 37.1, f.g = 56%.	Frequent experience of headache-related symptoms within 20 minutes of using a 900 MHz GSM MP.	Age of <18 or >75 y.o, pregnancy, psychotic illness, use of antidepressants, report of severe symptoms at baseline while in the testing room.	Subjective report.
Eltiti et al., 2007 (UK) [52].	Provocation	Voluntary participation through local advertising, IEI-EMF action groups & word of mouth.	MP & base station-specific	N = 56, m.a = 46.1, f.g = 42.9%.	Individual experience of negative health effects attributed to EMF emitted from mobile phone devices and/or base stations, based on the “Electromagnetic Hypersensitivity Questionnaire” [53].	History of brain injury, currently suffering from epilepsy or claustrophobia, undergone treatment for mental disease or psycho-active medication within 4 months before the study.	Subjective report.
Schröttner et al., 2007 (Austria) [54].	Provocation	Three different recruitment sources: 1. EMF self-help groups. 2. Through advertisements in local newspapers & inviting patients that contacted a health care service/institution for their EMF-attributed symptoms. 3. Subjects reporting severe sleep problems being deeply convinced that these were caused by EMF exposure.	General	Recruitment 1: N = 37, a.r = 27-81, f.g = 67.6%. Recruitment 2: N = 29, a.r = 32-63, f.g = 79%. Recruitment 3: N = 24, a.r = 37-73, f.g = 62.5%.	Self-reported hypersensitivity to electricity, attribution of symptoms to EMF, active avoidance behavior to EMF sources.	Sensitivity only to sources of flickering light such as VDU fluorescent tubes.	Medical examination (for part of the group of “Recruitment 2”).
Bamiou et al., 2008 (UK) [55].	Provocation	Voluntary participation after description of the study through advertisements at a health care services/institutions & relative website & short film shown on the national television.	MP-specific	N = 9, m.a = 36.7, f.g = 66.7.	Report of headache and/or disorientation, dizziness, muzziness, nausea attributed to mobile telephone use, age between 20–55 y.o, normal tympanometry & normal pure tone audiometric thresholds in both ears.	N.R/E.	Subjective report, audiometric examination.
Hillert et al., 2008 (Sweden) [56].	Provocation	Voluntary participation after description of the study in newspapers, or individual initiative.	MP-specific	N = 38, m.a = 28, f.g = 63.2%.	Report of headache, vertigo or other kind of pain or discomfort in the head attributed to MP use.	Attribution of symptoms to sources other than MP, medical or psychological illness, undergoing medication, sleep disorders, hypertension, pregnancy, history of severe injury.	Subjective report.
Kwon et al., 2008 (Finland) [57].	Provocation	Voluntary participation after description of the study in an advertisement that announced a monetary prize.	MP-specific	N = 2 male subjects, m.a = 37.	Report of suffering from severe symptomatology after use of a mobile phone, high score on a scale on EMF sensibility (defined as the individual ability to perceive EMF without necessarily developing symptoms).	Neurological disease, auditory abnormality, being on permanent medication.	Subjective report.
Landgrebe et al., 2008a (Austria & Germany) [58].	Provocation	Voluntary participation after description of the study in newspapers and informative events at public locations and institutions.	General	N = 88, m.a = 50.5, f.g = 58.4%.	A symptom score of at least 19 points on the “Regensburger EMF complaint list” [59], attribution of health symptoms to named EMF sources & age between 18–75 y.o	Unstable medical condition.	Subjective report.
Leitgeb et al., 2008 (Austria & Germany) [60].	Crossover field study	Voluntary participation after description of the study in media.	General	N = 43, m.a = 55.5, f.g = 60.5%.	Personal conviction on a causal role of EMF indicated by the employment of precautionary activities and/or measures (e.g. reducing fields, measuring exposure in the household etc.), above-normal symptom scores on standardized questionnaires such as the “Freiburger Personality Inventory” [61] and “PSQI” [62] (at least 5 points on the latter).	Neurological & psychiatric disorders, somatic conditions that could account for sleep disturbances, drug consumption less than 2 weeks before the study, medical treatment for severe conditions.	Subjective report.
Augner et al., 2009 (Austria) [63].	Provocation plus cross-sectional data	Voluntary participation.	General	N = 8, a.r = 18-67.	Self-reported electromagnetic hypersensitivity (rated as “strong” or “very strong”).	N.R/E.	Subjective report.
Furubayashi et al., 2009 (Japan) [64].	Provocation	Randomly selected female subjects (N = 2472).	MP & base station-specific	N = 11, m.a = 37.3.	Report of symptoms attributed to MP use and/or exposure to base stations, symptoms should persist “always” or “almost always”	History of myocardial infarction epilepsy or other (psycho) pathological condition, undergoing medical treatment for severe medical conditions.	Subjective report.
Nam et al., 2009 (South Korea) [65].	Provocation	Voluntary participation after description of the study through advertisements at a health care service/institution.	MP-specific.	N = 18, m.a = 26.1, f.g = 55.5%.	Self-reported hypersensitivity to EMF emitted only by CDMA cellular phones.	Self-reported hypersensitivity to other EMF sources, subjects concerned with payment for volunteering,	Subjective report.
Szemerszky et al., 2010 (Hungary) [66].	Provocation	Voluntary participation of university students.	General	N.R.	Self-reported electrosensitivity (rated from “not at all” to “fully”).	Severe medical disorders, health conditions such as premenstrual syndrome and common cold that could account for the reported symptomatology	Subjective report.
Nieto-Hernandez et al., 2011 (UK) [67].	Provocation	Voluntary participation after description of the study within UK Police Forces with the use of circular emails, notices in police newsletters and intranet sites & advertisements in police-related magazines & websites.	TETRA-specific	N = 60, m.a = 35.6, f.g = 11.7%.	Report of symptoms attributed to TETRA, report of being at least 70 % sure that the radio signal was the responsible source, occurrence of symptoms/sensations within an hour of radio use and when the radio was used near the head.	Pregnancy/trying to conceive, medical or psychological condition which could account for similar symptoms.	Subjective report.

*Although the studies of Österberg et al. [45] and Carlsson et al. [7] are based on the same sample [46], they have some differences in terms of inclusion criteria and/or identification methods.

Abbreviations: N.R., Not reported; N.R/E, Not reported or employed; EMF, Electromagnetic fields; IEI-EMF, Idiopathic environmental intolerance attributed to EMF; m.a, Mean age; a.r, Age range; f.g, Female gender distribution; y.o; Years old; MP, Mobile phone(s); VDT, Video display terminal: VDU, Video display units; GSM, Global system for mobile communications; CDMA, Code division multiple access; TETRA, Terrestrial trunked radio; PSQI, Pittsburgh sleep quality index.