Characterization of the Core Temperature Response of Free-Moving Rats to 1.95 GHz Electromagnetic Fields

Bioelectromagnetics · 2025 · Harm · Low evidence

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HarmLow evidencePaper 2617

Study snapshot

PublicationBioelectromagnetics · 2025

Study typeanimal

Reported directionHarm

Evidence ratingLow

Abstract

Category: Bioelectromagnetics, Physiology Tags: RF-EMF, rat study, core body temperature, specific absorption rate, electromagnetic field exposure, thermal response, animal model DOI: 10.1002/bem.70013 URL: onlinelibrary.wiley.com Overview This study examined how free-moving adult male and female Sprague Dawley rats responded in core body temperature (CBT) to exposure at 1.95 GHz radiofrequency electromagnetic fields (RF-EMFs). Using temperature capsules implanted in the rats' intraperitoneal cavities and radiotelemetry, researchers measured CBT changes during and after a 3-hour RF-EMF exposure inside specially designed reverberation chambers. Findings - Rats were exposed to RF-EMFs at whole-body average specific absorption rate (WBA-SAR) levels of 0.1, 0.4, and 4 W/kg, compared with a sham (no exposure) control. - Significant peak increase in CBT (+0.49°C) was detected after 26 minutes of exposure at 4 W/kg, with no significant increase at 0.1 or 0.4 W/kg at that same time. - In the last 30 minutes of RF-EMF exposure: - 4 W/kg: temperature increase of 0.62°C - 0.4 W/kg: temperature increase of 0.14°C - 0.1 W/kg: no significant temperature increase - Twenty minutes after exposure ended, only the 4 W/kg group retained a significantly higher temperature compared to sham (+0.37°C). - The maximum CBT increase remained less than 1°C, suggesting effective thermoregulatory compensation up to these RF-EMF exposures. - Temperature elevation at 4 W/kg significantly decreased immediately upon the end of exposure, highlighting that post-exposure measurement may underestimate maximum temperature effects of RF-EMF. Conclusion The study demonstrates that RF-EMF exposures at higher SAR values (notably 4 W/kg) can cause measurable thermal effects in animal models. While the rats compensated well for thermal load, these findings confirm a physiological response to electromagnetic fields, which supports the importance of safety limits when considering health risks from electromagnetic field exposures.

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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 directionharm

PopulationFree-moving adult male and female Sprague Dawley rats

Sample sizeNot supplied

ExposureRF · 1950 MHz · 4 W/kg · 3-hour exposure

Evidence strengthLowConfidence: 78% · Peer reviewed: yes

Main findings

Free-moving Sprague Dawley rats exposed for 3 hours to 1.95 GHz RF-EMF showed significant core body temperature increases at higher whole-body average SAR. A peak CBT increase of +0.49°C occurred after 26 minutes at 4 W/kg, and during the last 30 minutes CBT increased by 0.62°C (4 W/kg) and 0.14°C (0.4 W/kg), while 0.1 W/kg showed no significant increase; 20 minutes post-exposure only the 4 W/kg group remained significantly elevated (+0.37°C) versus sham.

Outcomes measured

Core body temperature (CBT) change
Thermal/thermoregulatory response

Limitations

Sample size not reported in provided abstract/metadata
Only Sprague Dawley rats (adult, male and female); generalizability to other species/conditions not stated
Exposure duration limited to a single 3-hour session; longer-term effects not addressed
Outcome focused on core temperature/thermal response; non-thermal endpoints not assessed

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "RF",
    "source": null,
    "frequency_mhz": 1950,
    "sar_wkg": 4,
    "duration": "3-hour exposure"
  },
  "population": "Free-moving adult male and female Sprague Dawley rats",
  "sample_size": null,
  "outcomes": [
    "Core body temperature (CBT) change",
    "Thermal/thermoregulatory response"
  ],
  "main_findings": "Free-moving Sprague Dawley rats exposed for 3 hours to 1.95 GHz RF-EMF showed significant core body temperature increases at higher whole-body average SAR. A peak CBT increase of +0.49°C occurred after 26 minutes at 4 W/kg, and during the last 30 minutes CBT increased by 0.62°C (4 W/kg) and 0.14°C (0.4 W/kg), while 0.1 W/kg showed no significant increase; 20 minutes post-exposure only the 4 W/kg group remained significantly elevated (+0.37°C) versus sham.",
  "effect_direction": "harm",
  "limitations": [
    "Sample size not reported in provided abstract/metadata",
    "Only Sprague Dawley rats (adult, male and female); generalizability to other species/conditions not stated",
    "Exposure duration limited to a single 3-hour session; longer-term effects not addressed",
    "Outcome focused on core temperature/thermal response; non-thermal endpoints not assessed"
  ],
  "evidence_strength": "low",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "RF-EMF",
    "1.95 GHz",
    "1950 MHz",
    "rat",
    "Sprague Dawley",
    "core body temperature",
    "thermal response",
    "whole-body average SAR",
    "WBA-SAR",
    "reverberation chamber",
    "radiotelemetry"
  ],
  "suggested_hubs": []
}

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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: 10.1002/bem.70013
PubMed: Not supplied

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