In situ electric field dosimetry analysis for powerline frequency peripheral nerve magnetic stimulation

Scientific Reports · 2025 · Harm · Low evidence

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HarmLow evidencePaper 2561

Study snapshot

PublicationScientific Reports · 2025

Study typeexposure_assessment

Reported directionHarm

Evidence ratingLow

Abstract

Category: Electromagnetic Dosimetry, Neurophysiology Tags: electromagnetic fields, dosimetry, powerline frequency, nerve stimulation, human exposure, modeling, health risk DOI: 10.1038/s41598-025-12284-0 URL: nature.com Overview Humans are exposed to environmental 60 Hz magnetic fields (MFs), which induce electric fields (EFs) and currents within the body—mechanisms that may potentially stimulate the peripheral nervous system (PNS). There is significant uncertainty regarding the threshold for PNS stimulation by 60 Hz MFs. Accurate dosimetry and understanding of these processes are essential to inform safety guidelines. Methods - This research modeled a new extremely low frequency MF exposure system designed for the human leg, analyzing EFs generated by a 60 Hz magnetic field at both skin and nerve levels. - Two nerve excitation models were used: the spatially extended nonlinear node (SENN) model and the McIntyre-Richardson-Grill (MRG) model, the latter considered the gold standard in electrostimulation research. - A Helmholtz-like coil system was engineered to produce EFs sufficient for peripheral nerve stimulation; field calculations incorporated Biot-Savart and Faraday laws. - Sim4Life simulations determined EF distributions within a realistic human body model and across specific nerve pathways in the leg. Findings - High EF intensities were detected in multiple sensory and sensory-motor nerves, indicating a risk of nerve stimulation at plausible environmental exposures. - The threshold for nerve stimulation was lower using the MRG model compared to the SENN model, suggesting that health risks could be underestimated by older modeling techniques. - Nerve orientation relative to the induced field significantly impacts stimulation risk and must be carefully considered in dosimetric assessments and safety standards. Conclusion This work underscores the necessity of comprehensive and realistic dosimetric modeling for designing and validating MF exposure systems. There is a clear need for experimental data to further refine safety guidelines protecting both workers and the general public from possible electromagnetic field (EMF) health effects, particularly concerning nerve stimulation risks from environmental powerline frequencies.

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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 typeexposure_assessment

Effect directionharm

PopulationHumans (realistic human body model; leg and peripheral nerves modeled)

Sample sizeNot supplied

ExposureELF · 6e-05 MHz

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Modeling of a 60 Hz magnetic-field exposure system for the human leg found high induced EF intensities in multiple sensory and sensory-motor nerves, indicating potential risk of peripheral nerve stimulation. Predicted stimulation thresholds were lower with the MRG model than with the SENN model, and nerve orientation relative to the induced field substantially affected stimulation risk.

Outcomes measured

Induced electric field (EF) distributions in leg tissues and nerves
Peripheral nerve stimulation (PNS) thresholds (MRG vs SENN nerve excitation models)
Effect of nerve orientation on stimulation risk

Limitations

Study is based on computational modeling/simulation; abstract notes a need for experimental data to refine safety guidelines.
No quantitative exposure levels, thresholds, or validation results are provided in the abstract.

View raw extracted JSON

{
  "study_type": "exposure_assessment",
  "exposure": {
    "band": "ELF",
    "source": "powerline frequency magnetic field exposure system (Helmholtz-like coil)",
    "frequency_mhz": 6e-05,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Humans (realistic human body model; leg and peripheral nerves modeled)",
  "sample_size": null,
  "outcomes": [
    "Induced electric field (EF) distributions in leg tissues and nerves",
    "Peripheral nerve stimulation (PNS) thresholds (MRG vs SENN nerve excitation models)",
    "Effect of nerve orientation on stimulation risk"
  ],
  "main_findings": "Modeling of a 60 Hz magnetic-field exposure system for the human leg found high induced EF intensities in multiple sensory and sensory-motor nerves, indicating potential risk of peripheral nerve stimulation. Predicted stimulation thresholds were lower with the MRG model than with the SENN model, and nerve orientation relative to the induced field substantially affected stimulation risk.",
  "effect_direction": "harm",
  "limitations": [
    "Study is based on computational modeling/simulation; abstract notes a need for experimental data to refine safety guidelines.",
    "No quantitative exposure levels, thresholds, or validation results are provided in the abstract."
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "60 Hz",
    "extremely low frequency",
    "magnetic fields",
    "induced electric fields",
    "dosimetry",
    "peripheral nerve stimulation",
    "MRG model",
    "SENN model",
    "Sim4Life",
    "human exposure",
    "powerline frequency"
  ],
  "suggested_hubs": [
    {
      "slug": "occupational-exposure",
      "weight": 0.55,
      "reason": "Conclusion mentions protecting workers as well as the general public from powerline-frequency EMF effects."
    }
  ]
}

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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: 10.1038/s41598-025-12284-0
PubMed: Not supplied

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