Occupational exposure to ELF magnetic fields and risk of Alzheimer disease: systematic review and meta- analysis

2017 · Harm · Low evidence

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HarmLow evidencePaper 2178

Study snapshot

Publicationmanual · 2017

Study typemeta_analysis

Reported directionHarm

Evidence ratingLow

Abstract

Occupational exposure to ELF magnetic fields and risk of Alzheimer disease: systematic review and meta- analysis Jalilian H, Teshnizi SH, Röösli M, Neghab M. Occupational exposure to extremely low frequency magnetic fields and risk of Alzheimer disease: A systematic review and meta-analysis. Neurotoxicology. 2017 Dec 24. pii: S0161- 813X(17)30239-5. doi: 10.1016/j.neuro.2017.12.005. Abstract INTRODUCTION: Occupational exposure to extremely low frequency magnetic fields (ELF-MF) occurs in many occupations such as welders, electric utility workers, train drivers and sewing machine operators. There is some evidence suggesting ELF-MF exposure to be a risk factor for Alzheimer's disease (AD). The current study aims at systematically reviewing the literature and conducting a meta-analysis to evaluate the risk of AD amongst workers exposed to ELF-MF. METHODS: Bibliographic databases were searched including PubMed, EMBASE, Cochrane Library, and Web of Science in November 2017. Risk of bias was assessed in the all included studies. Pooled estimates were obtained using random-effects meta-analysis. In addition, sources of heterogeneity between studies and publication bias were explored. RESULTS: In total, 20 articles met the inclusion criteria. The pooled results suggest an increased risk of AD (RR: 1.63; 95% CI: 1.35, 1.96). Higher risk estimates were obtained from case-control studies (OR: 1.80; 95% CI: 1.40, 2.32) than from cohort studies (RR: 1.42; 95% CI: 1.08, 1.87). A moderate to high heterogeneity (I2 = 61.0%) and indication for publication bias (Egger test: p < 0.001) were found. CONCLUSION: The results suggested that occupational exposure to ELF-MF might increase the risk of AD. However, this suggestion should be interpreted with caution given the moderate to high heterogeneity and indication for publication bias. ncbi.nlm.nih.gov

Machine Enhanced Logic

AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typemeta_analysis

Effect directionharm

PopulationWorkers in occupations with ELF magnetic field exposure (e.g., welders, electric utility workers, train drivers, sewing machine operators)

Sample sizeNot supplied

ExposureELF

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Systematic review/meta-analysis of 20 articles found an increased risk of Alzheimer’s disease associated with occupational ELF magnetic field exposure (pooled RR 1.63; 95% CI 1.35–1.96). Higher estimates were reported in case-control studies (OR 1.80; 95% CI 1.40–2.32) than cohort studies (RR 1.42; 95% CI 1.08–1.87), with moderate-to-high heterogeneity (I2=61%) and indication of publication bias (Egger p<0.001).

Outcomes measured

Alzheimer's disease risk

Limitations

Moderate to high heterogeneity across included studies (I2=61.0%)
Indication of publication bias (Egger test p<0.001)
Sample sizes of included studies not reported in abstract

View raw extracted JSON

{
  "study_type": "meta_analysis",
  "exposure": {
    "band": "ELF",
    "source": "occupational",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Workers in occupations with ELF magnetic field exposure (e.g., welders, electric utility workers, train drivers, sewing machine operators)",
  "sample_size": null,
  "outcomes": [
    "Alzheimer's disease risk"
  ],
  "main_findings": "Systematic review/meta-analysis of 20 articles found an increased risk of Alzheimer’s disease associated with occupational ELF magnetic field exposure (pooled RR 1.63; 95% CI 1.35–1.96). Higher estimates were reported in case-control studies (OR 1.80; 95% CI 1.40–2.32) than cohort studies (RR 1.42; 95% CI 1.08–1.87), with moderate-to-high heterogeneity (I2=61%) and indication of publication bias (Egger p<0.001).",
  "effect_direction": "harm",
  "limitations": [
    "Moderate to high heterogeneity across included studies (I2=61.0%)",
    "Indication of publication bias (Egger test p<0.001)",
    "Sample sizes of included studies not reported in abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "extremely low frequency",
    "ELF-MF",
    "occupational exposure",
    "magnetic fields",
    "Alzheimer disease",
    "systematic review",
    "meta-analysis",
    "case-control",
    "cohort",
    "publication bias",
    "heterogeneity"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.95,
      "reason": "Focuses on occupational exposure to ELF magnetic fields across multiple worker groups and Alzheimer’s disease risk."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1016/j.neuro.2017.12.005
PubMed: Not supplied

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