Comparing the Effects of Long-term Exposure to Extremely Low-frequency Electromagnetic Fields With

2021 · Mixed · Low evidence

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MixedLow evidencePaper 1281

Study snapshot

Publicationmanual · 2021

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

Comparing the Effects of Long-term Exposure to Extremely Low-frequency Electromagnetic Fields With Different Values on Learning, Memory, Anxiety, and β-amyloid Deposition in Adult Rats Faraji N, Salehi I, Alizadeh A, Pourgholaminejad A, Komaki A, Taheri Azandaryani M, et al . Comparing the Effects of Long-term Exposure to Extremely Low-frequency Electromagnetic Fields With Different Values on Learning, Memory, Anxiety, and β-amyloid Deposition in Adult Rats. BCN. 2021; 12 (6) :849-860 Abstract Introduction: Extremely Low-Frequency Electromagnetic Fields (ELF-EMFs) have gathered significant consideration for their possible pathogenicity. However, their effects on the nervous system’s functions were not fully clarified. This study aimed to assay the impact of ELF-EMFs with different intensities on memory, anxiety, antioxidant activity, β-amyloid (Aβ) deposition, and microglia population in rats. Methods: Fifty male adult rats were randomly separated into 5 groups; 4 were exposed to a flux density of 1, 100, 500, and 2000 microtesla (µT), 50 Hz frequency for one h/day for two months, and one group as a control group. The control group was without ELF-EMF stimulation. After 8 weeks, passive avoidance and Elevated Plus Maze (EPM) tests were performed to assess memory formation and anxiety-like behavior, respectively. Total free thiol groups and the index of lipid peroxidation were evaluated. Additionally, for detection of Aβ deposition and stained microglia in the brain, anti-β-amyloid and anti-Iba1 antibodies were used. Results: The step-through latency in the retention test in ELF-EMF exposure groups (100500 & 2000 µT) was significantly greater than the control group (P<0.05). Furthermore, the frequency of the entries into the open arms in ELF-EMF exposure groups (especially 2000 µT) decreased than the control group (P<0.05). No Aβ depositions were detected in the hippocampus of different groups. An increase in microglia numbers in the 100, 500, and 2000 µT groups was observed compared to the control and one µT group. Conclusion: Exposure to ELF-EMF had an anxiogenic effect on rats, promoted memory, and induced oxidative stress. No Aβ depositions were detected in the brain. Moreover, the positive impact of ELF-EMF was observed on the microglia population in the brain. bcn.iums.ac.ir

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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 typeanimal

Effect directionmixed

PopulationMale adult rats

Sample size50

ExposureELF · 0.05 MHz · 1 h/day for two months (8 weeks)

Evidence strengthLowConfidence: 78% · Peer reviewed: unknown

Main findings

Rats exposed to 50 Hz ELF-EMF at 100, 500, and 2000 µT showed significantly greater step-through latency in the retention test versus controls (P<0.05), while open-arm entries in the elevated plus maze decreased (especially at 2000 µT; P<0.05). No Aβ depositions were detected in the hippocampus across groups; microglia numbers increased in the 100, 500, and 2000 µT groups compared with control and 1 µT.

Outcomes measured

Learning/memory (passive avoidance step-through latency)
Anxiety-like behavior (Elevated Plus Maze; open-arm entries)
Antioxidant activity (total free thiol groups)
Lipid peroxidation index
β-amyloid (Aβ) deposition in hippocampus (anti-β-amyloid staining)
Microglia population (Iba1-stained microglia)

Limitations

Journal, publication year, and peer-review status not explicitly stated in provided metadata (though citation indicates BCN. 2021;12(6):849-860).
No quantitative effect sizes reported in the abstract beyond significance statements.
Exposure source/setup details (e.g., apparatus, field uniformity) not described in the abstract.
Oxidative stress results are mentioned in the conclusion but specific findings for thiols/lipid peroxidation are not reported in the results section of the abstract.

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "ELF",
    "source": null,
    "frequency_mhz": 0.05,
    "sar_wkg": null,
    "duration": "1 h/day for two months (8 weeks)"
  },
  "population": "Male adult rats",
  "sample_size": 50,
  "outcomes": [
    "Learning/memory (passive avoidance step-through latency)",
    "Anxiety-like behavior (Elevated Plus Maze; open-arm entries)",
    "Antioxidant activity (total free thiol groups)",
    "Lipid peroxidation index",
    "β-amyloid (Aβ) deposition in hippocampus (anti-β-amyloid staining)",
    "Microglia population (Iba1-stained microglia)"
  ],
  "main_findings": "Rats exposed to 50 Hz ELF-EMF at 100, 500, and 2000 µT showed significantly greater step-through latency in the retention test versus controls (P<0.05), while open-arm entries in the elevated plus maze decreased (especially at 2000 µT; P<0.05). No Aβ depositions were detected in the hippocampus across groups; microglia numbers increased in the 100, 500, and 2000 µT groups compared with control and 1 µT.",
  "effect_direction": "mixed",
  "limitations": [
    "Journal, publication year, and peer-review status not explicitly stated in provided metadata (though citation indicates BCN. 2021;12(6):849-860).",
    "No quantitative effect sizes reported in the abstract beyond significance statements.",
    "Exposure source/setup details (e.g., apparatus, field uniformity) not described in the abstract.",
    "Oxidative stress results are mentioned in the conclusion but specific findings for thiols/lipid peroxidation are not reported in the results section of the abstract."
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "unknown",
  "keywords": [
    "ELF-EMF",
    "50 Hz",
    "microtesla",
    "rats",
    "memory",
    "passive avoidance",
    "anxiety",
    "elevated plus maze",
    "oxidative stress",
    "β-amyloid",
    "microglia",
    "Iba1"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.2,
      "reason": "Study uses ELF magnetic flux densities (µT) relevant to some occupational ELF contexts, though conducted in rats and not explicitly occupational."
    }
  ]
}

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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.

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