emf and subjective symptoms...schreier spm, 2006 4th ebea course. m. röösli, subjective symptoms,...
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Ebea, Erice (Sicily), 29/03/2008
EMF and subjective symptoms
M. Röösli, PhDUniversity of BernInstitute of Social and Preventive Medicine
4th EBEA Course. M. Röösli, subjective symptoms, 29/03/2008
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Content
> Electromagnetic hypersentitivity (EHS):Definitions/prevalence
> Perception of low level RF-EMF> Symptoms and RF-EMF: short term> Therapeutic options> Conclusions
4th EBEA Course. M. Röösli, subjective symptoms, 29/03/2008
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Definitions
> Terms:— Electromagnetic Hypersensitivity (EHS)— Electrosensitivity— Idiopathic environmental Intolerances (IEI-EMF)
> EHS is characterized by a variety of non-specificsymptoms, which afflicted individuals attribute toexposure to EMF (WHO, fact sheet N° 296).
> No established biological mechanism
4th EBEA Course. M. Röösli, subjective symptoms, 29/03/2008
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Symptoms attributed to EMF
Proportion [%]
Data from a representative survey in Switzerland(n=2048, thereof 5% attributed symptoms to EMF)
Schreier SPM, 2006
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Attributed causes
Proportion [%]
Schreier SPM, 2006
80% of the EHS suspected specific EMF sources.
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Subjective
perception of
EMF exposure
II
other factors
Subjective
perception of
health state
III
Perception of
EMF as a health
risk
Attributing health
symptoms to EMF
(EHS)subjective
pathway Subjective
perception of
EMF exposure
II
other factors
Subjective
perception of
health state
III
Perception of
EMF as a health
risk
Attributing health
symptoms to EMF
(EHS)subjective
pathway
?
Objective
distribution of
EMF in the
environment
I
Objective
health state
IV
other factors
biological
mechanism
?
Objective
distribution of
EMF in the
environment
I
Objective
health state
IV
other factors
biological
mechanism
Schreier SPM, 2006
EHS model
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Prevalence
> Prevalence:— Stockholm: 1.5% (Hillert, SJWEH, 2002)— California: 3.2% (Levallois, EHP, 2002)— United Kingdom: 4% (Eltiti, 2007)— Germany: 8-10% (Infas 2002-2006)— Switzerland: 5.0% (Schreier, SPM, 2006)— Austria: women: 4.2%, men:1.7% (Leitgeb & Schröttner,
BioEM, 2003)
> A substantial part of EHS individuals claims toimmediately perceive low level EMF when theyare exposed (56%) and to develop symptomswithin a few minutes (53%) (Röösli, 2004).
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3 different aspects of EHS
> Perception of low-level fields: sensibility (Leitgeband Schröttner, 2003)provocation studies
> Symptoms and RF-EMF: short termrandomized trials/human laboratory study
> Symptoms and RF-EMF: long termepidemiological/observational studies
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Provocation study
> Repeated tests with different exposureconditions (incl. Sham): randomised
> Neither the study participants nor the studyassistant know the exposure condition: doubleblind.
> Study participants state whether they perceiveexposure or not (or symptoms).
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Laboratory of the Swiss UMTS study
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Perceived field intensity
> Subjective assessment of the perceived field on a 100 visualanalog scale (VAS):
nein, gar nicht ja, sehr stark
Wert 0 Wert 36 Wert 100
4th EBEA Course. M. Röösli, subjective symptoms, 29/03/2008
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Perceived field intensity(Regel et al, EHP, 2006)
0 V/m1 V/m10 V/m
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Perception of singulartranscranial magnetic stimuli(Frick,et al, BioEM, 2005)
EHS individuals:Controls:
EHS individuals showed more false alarms.Differentiation between sham and real exposure waspoor in EHS individuals
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Provocation studies
> Systematic literature search: 7 double-blind,peer-reviewed papers on RF-EMF (until August,2007)
> Exposure:— Mobile phone: 5 GSM 900— base station: 1 GSM, 2 UMTS
> Exposure duration: 2-50 minutes> Number of sessions per individual: 3-12> Collectives: 182 hypersensitive (EHS)
individuals and 332 healthy volunteers.
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Meta-analysis of provocation studies(correct field detection rate)
Overall
Studies with non-EHS collective
Rubin, 2006
Studies with EHS collective
Study
Radon, 1998
Oftedal, 2007
Eltiti, 2007 (5')
Loughran, 2005
Eltiti, 2007 (5')
Subtotal
Regel, 2006
Eltiti, 2007 (50')
Subtotal
Eltiti, 2007 (50')
Regel, 2006
Rubin, 2006
Wolf, 2006
0.04 (-0.02, 0.11)
0.04 (-0.15, 0.25)
ES (95% CI)
0.20 (-0.04, 0.45)
0.07 (-0.14, 0.28)
0.02 (-0.12, 0.18)
0.23 (-0.09, 0.51)
-0.01 (-0.20, 0.21)
0.07 (-0.02, 0.17)
-0.10 (-0.39, 0.20)
0.02 (-0.13, 0.18)
0.02 (-0.07, 0.10)
0.08 (-0.14, 0.35)
0.13 (-0.25, 0.49)
-0.03 (-0.22, 0.18)
0.09 (-0.26, 0.59)
0.04 (-0.02, 0.11)
0.04 (-0.15, 0.25)
ES (95% CI)
0.20 (-0.04, 0.45)
0.07 (-0.14, 0.28)
0.02 (-0.12, 0.18)
0.23 (-0.09, 0.51)
-0.01 (-0.20, 0.21)
0.07 (-0.02, 0.17)
-0.10 (-0.39, 0.20)
0.02 (-0.13, 0.18)
0.02 (-0.07, 0.10)
0.08 (-0.14, 0.35)
0.13 (-0.25, 0.49)
-0.03 (-0.22, 0.18)
0.09 (-0.26, 0.59)
worse than chance better than chance 0-.6 -.4 -.2 0 .2 .4 .6
Röösli, Env Res, 2008
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Mobile phone vs. base stationstudies
Overall
Loughran, 2005
Eltiti, 2007 (50')
Regel, 2006
Subtotal
Subtotal
Oftedal, 2007
Wolf, 2006
Base station exposure:
Regel, 2006
Radon, 1998
Eltiti, 2007 (50')
Rubin, 2006
Eltiti, 2007 (5')
Eltiti, 2007 (5')
Rubin, 2006
Mobile telephone exposure:
Study
0.04 (-0.02, 0.11)
0.23 (-0.09, 0.51)
0.08 (-0.14, 0.35)
-0.10 (-0.39, 0.20)
0.02 (-0.06, 0.10)
0.09 (-0.02, 0.20)
0.07 (-0.14, 0.28)
0.09 (-0.26, 0.59)
0.13 (-0.25, 0.49)
0.20 (-0.04, 0.45)
0.02 (-0.13, 0.18)
0.04 (-0.15, 0.25)
-0.01 (-0.20, 0.21)
0.02 (-0.12, 0.18)
-0.03 (-0.22, 0.18)
ES (95% CI)
0.04 (-0.02, 0.11)
0.23 (-0.09, 0.51)
0.08 (-0.14, 0.35)
-0.10 (-0.39, 0.20)
0.02 (-0.06, 0.10)
0.09 (-0.02, 0.20)
0.07 (-0.14, 0.28)
0.09 (-0.26, 0.59)
0.13 (-0.25, 0.49)
0.20 (-0.04, 0.45)
0.02 (-0.13, 0.18)
0.04 (-0.15, 0.25)
-0.01 (-0.20, 0.21)
0.02 (-0.12, 0.18)
-0.03 (-0.22, 0.18)
ES (95% CI)
worse than chance better than chance 0-.6 -.4 -.2 0 .2 .4 .6
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Overall
5
30
30
45
50
5
30
2
50
5
50
Duration
45
0.04 (-0.02, 0.11)
-0.01 (-0.20, 0.21)
-0.03 (-0.22, 0.18)
0.07 (-0.14, 0.28)
0.13 (-0.25, 0.49)
0.02 (-0.13, 0.18)
0.02 (-0.12, 0.18)
0.04 (-0.15, 0.25)
0.20 (-0.04, 0.45)
0.08 (-0.14, 0.35)
0.09 (-0.26, 0.59)
0.23 (-0.09, 0.51)
ES (95% CI)
-0.10 (-0.39, 0.20)
0.04 (-0.02, 0.11)
-0.01 (-0.20, 0.21)
-0.03 (-0.22, 0.18)
0.07 (-0.14, 0.28)
0.13 (-0.25, 0.49)
0.02 (-0.13, 0.18)
0.02 (-0.12, 0.18)
0.04 (-0.15, 0.25)
0.20 (-0.04, 0.45)
0.08 (-0.14, 0.35)
0.09 (-0.26, 0.59)
0.23 (-0.09, 0.51)
ES (95% CI)
-0.10 (-0.39, 0.20)
worse than chance better than chance 0-.6 -.4 -.2 0 .2 .4 .6
Sorted by exposure duration
[min]
4th EBEA Course. M. Röösli, subjective symptoms, 29/03/2008
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Meta regression
-0.193 to 0.2130.010Exposure duration [h]
-0.068 to 0.2020.067Mobile phone exposure
-0.078 to 0.1780.050EHS collective
95% Conf. intervalCoefficient
Röösli, Env Res, 2008
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Short term effects: Symptomscore after exposure(Regel et al, EHP, 2006)
0 V/m1 V/m10 V/m
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Example: Scandinavian Headachstudy (Oftedal et al, 2007)
> Open provocation with 38 persons, who reportheadache when using a mobile phone.
> 24 persons reacted with headache during theopen provocation.
> 17 persons agreed to participate at a doubleblind experiment.
> Under double blind condition: no associationbetween reported headache and exposure.
> Evidence for nocebo effect.
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Nocebo
> contrary to placebo> development of symptoms due to expectation
(e.g. concern)
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12
34
5
0 50 100 0 50 100
Sensitive Group Non-sensitive Group
current disposition linear fit
Sco
re
Perceived Field (VAS scale)
Symptom score after exposurevs. perceived field intensity(Regel et al, EHP, 2006)
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Short term effects
> Systematic literature search: 10 peer-reviewed trials onRF-EMF and symptoms (main outcome) (until Dec.2008)
> Design: 9 cross-over, 1 mixed> Blinding: 7 double, 2 single, 1 “blind”> Exposure:
— Mobile phone: 1 NMT, 6 GSM900, 1 GSM1800— base station: 1 GSM, 2 UMTS
> Exposure duration: 30-60 minutes (8), 3h (1), and 6nights (1)
> Collectives: 232 EHS and 460 non-EHS individuals
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Short term effects: randomised doubleblind trials
Rubin2006
Regel2006 Nocebo effects observed
No nocebo effect investigated
Oftedal2007
Wilen2006
Eltiti2007
Fritzer2007
Koivisto2001
Hietanen2001
No effect
Effect
Ridder-vold 2008
Hillert2008
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Summary I: we know…
> EHS is a self declaration based on own experiences.> The vast majority who claims to be able to perceive low
level EMF is not able to perceive fields in a laboratorydouble blind setting.
> EHS individuals overestimate their own exposure (morefalse alarms).
> Nocebo effects occur.> Short term effects from everyday EMF exposures on
well-being are unlikely.> There is no evidence that EHS individuals are more
susceptible to EMF than non EHS-individuals.
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Summary II: We do not know…
> Is there a small minority of individuals who is able toperceive low level EMF?
> Does whole body exposure close to the reference valuecause symptoms (> 10 V/m)?
> Are there any long term exposure effects (>1h)?> Does the signal characteristic matter?> Is there a difference between EHS and reference
individuals (e.g. blood pressure, cortical excitability,etc.)?
> What are the most effective and accepted therapeuticoptions for EHS individuals?
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Do EHS individuals differ fromthe rest of the population?
— Differences observed for:– Self reported symptoms (Regel 2006, Frick 2005, etc.)– Heart rate variability (Lyskov 2001, Wilen 2006)– Cortical excitability (Landgrebe 2007)– Hyperresponsiveness to sensor stimulation, heightened arousal
(Lyskov 2001)– Electrodermal activity (Lyskov 2001), skin conductance (Eltiti,
2007)
— No differences for cholinesterase activity (Hillert2001)
— Inconsistent results for heart rate (Lyskov 2001, Eltiti2007)
> Real differences or a psycho-physiologicalstress response when participating in EMFstudies?
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Therapeutic options
> Placebo works against the nocebo phenomena(e.g. "to neutralise" the exposure).
> Shiatsu worked in one trial (placebo?).> Affected individuals reported that reduction of
exposure was helpful, however, no beneficialeffect occurred in placebo-controlled studies(placebo).
> Some success was reported from cognitivebehavioural therapy, however, often notaccepted.
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Cognitive behavioural therapy
Rubin et al., 2006
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Sensitivity to environmental factors
> Different sensitivities to environmental factors iswell established:— e.g. not everybody reacts in the same way to heat,
coldness, etc.— e.g. not every smoker develops lung cancer
> Thus, if there were health effects from EMF:— not everybody would react -> different sensitivities— Currently, there is no evidence that such sensitivities
can be self perceived as EHS do claim.
> Are there long term EMF effects?