The effects of radiofrequency electromagnetic fields exposure on human self-reported symptoms: A

Abstract

The effects of radiofrequency electromagnetic fields exposure on human self-reported symptoms: A systematic review of human experimental studies (WHO SR8) (Note: Methodological problems with many studies included in this systematic review undermine the validity of this review paper.) Bosch-Capblanch X, Esu E, Oringanje CM, Dongus S, Jalilian H, Eyers J, Auer C, Meremikwu M, Röösli M. The effects of radiofrequency electromagnetic fields exposure on human self-reported symptoms: A systematic review of human experimental studies. Environment International. doi: 10.1016/j.envint.2024.108612. Available online 2 April 2024. Abstract Background The technological applications of radiofrequency electromagnetic fields (RF-EMF) have been steadily increasing since the 1950s exposing large proportions of the population. The World Health Organization (WHO) is assessing the potential health effects of exposure to RF-EMF. Objectives To systematically assess the effects of exposure to RF-EMF on self-reported non-specific symptoms in human subjects and to assess the accuracy of perception of presence or absence of RF- EMF exposure. Methods Eligibility criteria: experimental studies carried out in the general population and in individuals with idiopathic environmental intolerance attributed to EMF (IEI-EMF), in any language. Information sources: Medline, Web of Science, PsycInfo, Cochrane Library, Epistemonikos and Embase and consulted the EMF portal, searched till April 2022. Risk of bias: we used the Risk of Bias (RoB) tool developed by OHAT adapted to the topic of this review. Synthesis of results: we synthesized studies using random effects meta-analysis and sensitivity analyses where appropriate. Results Included studies: 41 studies were included, mostly cross over trials and from Europe, with a total of 2,874 participants. Synthesis of results: considering the primary outcomes, we carried out meta-analyses of 10 exposure- outcomes pairs. All evidence suggested no or small non-significant effects of exposure on symptoms with high (three comparisons), moderate (four comparisons), low (one comparison) or very low (two comparisons) certainty of evidence. The effects (standard mean difference, where positive values indicate presence of symptom being exposed) in the general population for head exposure were (95% confidence intervals) 0.08 (−0.07 to 0.22) for headache, −0.01 (−0.22 to 0.20) for sleeping disturbances and 0.13 (−0.51 to 0.76) for composite symptoms; and for whole-body exposure: 0.09 (−0.35 to 0.54), 0.00 (−0.15 to 0.15) for sleeping disturbances and −0.05 (−0.17 to 0.07) for composite symptoms. For IEI- EMF individuals SMD ranged from −0.19 to 0.11, all of them with confidence intervals crossing the value of zero. Further, the available evidence suggested that study volunteers could not perceive the EMF exposure status better than what is expected by chance and that IEI-EMF individuals could not determine EMF conditions better than the general population. Discussion Limitations of evidence: experimental conditions are substantially different from real-life situations in the duration, frequency, distance and position of the exposure. Most studies were conducted in young, healthy volunteers, who might be more resilient to RF-EMF than the general population. The outcomes of interest in this systematic review were symptoms, which are self-reported. The available information did not allow to assess the potential effects of exposures beyond acute exposure and in elderly or chronic ill people. It cannot be ruled out that a real EMF effect in IEI-EMF groups is masked by a mix with insensitive subjects. However, studies on symptom reporting and/or field perception did not find any evidence that there are particularly vulnerable individuals in the IEI- EMF group, although in open provocation studies, when volunteers were informed about presence or absence of EMF exposure, such differences have been consistently observed. Interpretation: available evidence suggests that acute RF-EMF below regulatory limits does not cause symptoms and corresponding claims in everyday life are related to perceived and not real EMF exposure status. Excerpts 4.4. Implications for practice We could not find any evidence that would support an association between exposure to RF-EMF below regulatory recommendations and a large variety of short term reported symptoms; neither evidence that could suggest the capacity of individuals to detect the exposure to RF-EMF. This is the case for the general population, for IEI-EMF individuals, in the main meta-analyses as well as in the exposure– response and sensitivity analyses. While these findings cannot rule out other long term potential harms of RF-EMF, they suggest that the presence or absence of common symptoms may not become good clinical predictors of the occurrence or evolution of IEI-EMF. It may also indicate that notion of acute effects from RF-EMF below regulatory limits in the everyday environment are better explained with the nocebo or the attribution hypothesis (Dieudonné, 2020). 4.5. Implications for research The body of evidence in this review seems to consistently suggest the lack of association between EMF exposure and symptoms, in a variety of conditions and populations. The most critical aspect challenging the certainty of the evidence was the limited detail in the methodology of included studies, particularly in the issues related to the exposure randomisation and allocation concealment. While we hardly downgrades the evidence on the grounds of ‘indirectness’, most of the studies were focusing on adults, young adults and even adolescents, which may have limited the external validity of findings. In order to confirm the findings of this systematic review, future research should, thus, consider adhering to best reporting practices and considering a wider scope of participants, including, for example, the elderly. Future research should also be carried out standardising the design of experiments in terms of exposure ranges, timing and sequence of events, so as to make studies more comparable. It may be worth to increase exposure levels above regulatory limits for the general population to explore potential critical threshold for non-specific symptoms. Self-evident such studies need to follow a prudent approach to ensure that any symptoms are transient and do not result in a long term health impairment. Open access paper: sciencedirect.com

AI evidence extraction

Main findings

Across 41 human experimental studies (mostly crossover trials), meta-analyses of 10 exposure–outcome pairs suggested no or small non-significant effects of acute RF-EMF exposure on self-reported symptoms in both the general population and IEI-EMF individuals. Evidence also suggested participants could not perceive RF-EMF exposure status better than chance, and IEI-EMF individuals did not perform better than the general population.

Outcomes measured

• Self-reported non-specific symptoms (e.g., headache, sleeping disturbances, composite symptoms)
• Ability to perceive/detect presence or absence of RF-EMF exposure (field perception accuracy)

Limitations

• Experimental conditions differed from real-life exposure in duration, frequency, distance, and position
• Most studies involved young, healthy volunteers, limiting generalizability
• Outcomes were self-reported symptoms
• Insufficient information to assess effects beyond acute exposure or in elderly/chronic ill populations
• Methodological detail in included studies was often limited (e.g., exposure randomisation and allocation concealment)
• Possibility that effects in IEI-EMF could be masked by mixing sensitive and insensitive subjects (as discussed by authors)

Suggested hubs

• ehs (0.95)
  Includes IEI-EMF participants and evaluates symptom reporting and exposure perception in this group.

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    "study_type": "systematic_review",
    "exposure": {
        "band": "RF",
        "source": null,
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": "Acute/short-term exposure in experimental studies (as discussed in review)"
    },
    "population": "General population and individuals with idiopathic environmental intolerance attributed to EMF (IEI-EMF) in human experimental studies",
    "sample_size": 2874,
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    "main_findings": "Across 41 human experimental studies (mostly crossover trials), meta-analyses of 10 exposure–outcome pairs suggested no or small non-significant effects of acute RF-EMF exposure on self-reported symptoms in both the general population and IEI-EMF individuals. Evidence also suggested participants could not perceive RF-EMF exposure status better than chance, and IEI-EMF individuals did not perform better than the general population.",
    "effect_direction": "no_effect",
    "limitations": [
        "Experimental conditions differed from real-life exposure in duration, frequency, distance, and position",
        "Most studies involved young, healthy volunteers, limiting generalizability",
        "Outcomes were self-reported symptoms",
        "Insufficient information to assess effects beyond acute exposure or in elderly/chronic ill populations",
        "Methodological detail in included studies was often limited (e.g., exposure randomisation and allocation concealment)",
        "Possibility that effects in IEI-EMF could be masked by mixing sensitive and insensitive subjects (as discussed by authors)"
    ],
    "evidence_strength": "high",
    "confidence": 0.85999999999999998667732370449812151491641998291015625,
    "peer_reviewed_likely": "yes",
    "stance": "reassurance",
    "stance_confidence": 0.83999999999999996891375531049561686813831329345703125,
    "summary": "This WHO-linked systematic review assessed human experimental studies on whether RF-EMF exposure affects self-reported non-specific symptoms and whether people can detect exposure status. Across 41 studies (2,874 participants), meta-analyses suggested no or only small non-significant effects of acute RF-EMF exposure on symptoms in the general population and in IEI-EMF individuals. The review also reports that participants generally could not identify RF-EMF exposure conditions better than chance, while noting limitations related to indirectness and study methodology.",
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        "The review included 41 human experimental studies, mostly crossover trials, largely conducted in Europe.",
        "Total included participants across studies was 2,874.",
        "Meta-analyses of 10 exposure–outcome pairs suggested no or small non-significant effects on symptoms, with certainty ratings ranging from very low to high depending on comparison.",
        "In the general population, pooled effects for headache, sleep disturbances, and composite symptoms were small with confidence intervals crossing no effect.",
        "In IEI-EMF individuals, pooled standardized mean differences ranged from −0.19 to 0.11 with confidence intervals crossing zero.",
        "Evidence suggested participants could not detect RF-EMF exposure status better than chance, and IEI-EMF individuals did not outperform the general population.",
        "The authors highlight that experimental exposures differ from real-life conditions and that evidence is limited for long-term exposure and for elderly or chronically ill populations."
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    "categories": [
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    "tags": [
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        "Human Experimental Studies",
        "RF-EMF",
        "Self-Reported Symptoms",
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        "EHS",
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    "keywords": [
        "radiofrequency electromagnetic fields",
        "RF-EMF",
        "self-reported symptoms",
        "non-specific symptoms",
        "headache",
        "sleeping disturbances",
        "idiopathic environmental intolerance attributed to EMF",
        "IEI-EMF",
        "provocation studies",
        "field perception",
        "WHO SR8"
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    "social": {
        "tweet": "Systematic review (WHO SR8) of 41 human experimental studies (n=2,874) found no or small non-significant effects of acute RF-EMF exposure on self-reported symptoms, and participants generally could not detect exposure status better than chance. (Env Int, 2024)",
        "facebook": "A WHO-linked systematic review of 41 human experimental studies (2,874 participants) reports that acute RF-EMF exposure below regulatory limits showed no or only small non-significant effects on self-reported symptoms, and that people generally could not identify exposure status better than chance.",
        "linkedin": "Environment International (2024) published a WHO SR8 systematic review of 41 human experimental studies (n=2,874) assessing RF-EMF and self-reported symptoms plus exposure perception. Meta-analyses suggested no or small non-significant symptom effects under acute exposure conditions, and participants could not detect exposure status better than chance, with noted limitations regarding real-world relevance and study methods."
    }
}

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