Characterising core body temperature response of free-moving C57BL/6 mice to 1.95 GHz whole-body
Keywords
During a 2-h 1.95 GHz whole-body RF-EMF exposure, CBT peaked within the first 16 min relative to sham (+0.15, +0.31, +0.24, +0.37°C at 1.25, 2.5, 3.75, 5 W/kg, respectively), with statistical significance reported at WBA-SAR ≥ 2.5 W/kg. The elevation largely …
Study snapshot
Abstract
Characterising core body temperature response of free-moving C57BL/6 mice to 1.95 GHz whole-body radiofrequency-electromagnetic fields Sylvester E, Deng C, McIntosh R, Iskra S, Frankland J, McKenzie R, Croft RJ. Characterising core body temperature response of free-moving C57BL/6 mice to 1.95 GHz whole-body radiofrequency- electromagnetic fields. Bioelectromagnetics. 2024 Oct 14. doi: 10.1002/bem.22527. Highlights • Exposure of 1.95 GHz electromagnetic fields at 5 W/kg whole-body average specific absorption rate increases core body temperature by 0.4°C. • The increased thermal energy at 3.75 W/kg is effectively managed by thermoregulation (max increase = 0.24°C). • An extended habituation period prior to RF-EMF exposure is necessary to account for the large effect of handling on mice core body temperature. Abstract The present study investigated the core body temperature (CBT) response of free-moving adult male and female C57BL/6 mice, during and following a 2-h exposure to 1.95 GHz RF-EMF within custom-built reverberation chambers, using temperature capsules implanted within the intraperitoneal cavity and data continuously logged and transmitted via radiotelemetry postexposure. Comparing RF-EMF exposures (WBA-SAR of 1.25, 2.5, 3.75, and 5 W/kg) to the sham-exposed condition, we identified a peak in CBT within the first 16 min of RF-EMF exposure (+0.15, +0.31, +0.24, +0.37°C at 1.25, 2.5, 3.75, and 5 W/kg respectively; statistically significant at WBA-SAR ≥ 2.5 W/kg only), which largely dissipated for the remainder of the exposure period. Immediately before the end of exposure, only the CBT of the 5 W/kg condition was statistically differentiable from sham. Based on our findings, it is apparent that mice are able to effectively compensate for the increased thermal load at RF-EMF strengths up to 5 W/kg. In addition, the elevated CBT at the end of the exposure period in the 5 W/kg condition was statistically significantly reduced compared to the sham condition immediately after RF-EMF exposure ceased. This would indicate that measures of CBT following the end of an RF-EMF exposure period may not reflect the actual change in the CBT of mice caused by RF-EMF exposure in mice. Open access paper: onlinelibrary.wiley.com
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.
Main findings
During a 2-h 1.95 GHz whole-body RF-EMF exposure, CBT peaked within the first 16 min relative to sham (+0.15, +0.31, +0.24, +0.37°C at 1.25, 2.5, 3.75, 5 W/kg, respectively), with statistical significance reported at WBA-SAR ≥ 2.5 W/kg. The elevation largely dissipated over the remainder of exposure; immediately before exposure end, only the 5 W/kg condition differed from sham, and CBT immediately after exposure cessation was reported as statistically significantly reduced compared with sham in the 5 W/kg condition.
Outcomes measured
- Core body temperature (CBT) during exposure
- CBT following exposure
- Thermoregulatory response to RF-EMF thermal load
Limitations
- Sample size not reported in provided abstract/metadata
- Exposure source/context (e.g., device type) not specified beyond reverberation chambers
- Findings limited to mice (C57BL/6) and a 2-hour exposure duration
- Handling/habituation effects on CBT noted as large and requiring extended habituation
View raw extracted JSON
{
"study_type": "animal",
"exposure": {
"band": "RF",
"source": null,
"frequency_mhz": 1950,
"sar_wkg": 5,
"duration": "2-h exposure"
},
"population": "Free-moving adult male and female C57BL/6 mice",
"sample_size": null,
"outcomes": [
"Core body temperature (CBT) during exposure",
"CBT following exposure",
"Thermoregulatory response to RF-EMF thermal load"
],
"main_findings": "During a 2-h 1.95 GHz whole-body RF-EMF exposure, CBT peaked within the first 16 min relative to sham (+0.15, +0.31, +0.24, +0.37°C at 1.25, 2.5, 3.75, 5 W/kg, respectively), with statistical significance reported at WBA-SAR ≥ 2.5 W/kg. The elevation largely dissipated over the remainder of exposure; immediately before exposure end, only the 5 W/kg condition differed from sham, and CBT immediately after exposure cessation was reported as statistically significantly reduced compared with sham in the 5 W/kg condition.",
"effect_direction": "harm",
"limitations": [
"Sample size not reported in provided abstract/metadata",
"Exposure source/context (e.g., device type) not specified beyond reverberation chambers",
"Findings limited to mice (C57BL/6) and a 2-hour exposure duration",
"Handling/habituation effects on CBT noted as large and requiring extended habituation"
],
"evidence_strength": "low",
"confidence": 0.78,
"peer_reviewed_likely": "yes",
"keywords": [
"radiofrequency",
"RF-EMF",
"1.95 GHz",
"whole-body average SAR",
"WBA-SAR",
"core body temperature",
"thermoregulation",
"reverberation chamber",
"radiotelemetry",
"C57BL/6 mice"
],
"suggested_hubs": [
{
"slug": "animal-studies",
"weight": 0.9,
"reason": "Experimental RF-EMF exposure study in mice measuring physiological (temperature) response."
}
]
}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.22527
PubMed: Not supplied