Electromagnetic Exposure Dosimetry Study on Two Free Rats at 1.8 GHz via Numerical Simulation

PAPER manual 2021 Exposure assessment Effect: unclear Evidence: Insufficient

Read original paper → DOI: 10.3389/fpubh.2021.721166 Evidence Lab

Abstract

Electromagnetic Exposure Dosimetry Study on Two Free Rats at 1.8 GHz via Numerical Simulation Wang Xianghui, Xia Chengjie, Lu Lu, Qi Hongxin, Zhang Jie. Electromagnetic Exposure Dosimetry Study on Two Free Rats at 1.8 GHz via Numerical Simulation. Frontiers in Public Health. 9:1404. 2021. doi: 10.3389/fpubh.2021.721166 Abstract Normally, the impact of electromagnetic exposure on human health is evaluated by animal study. The biological effect caused by electromagnetic exposure on such experimental animals as rats has been proven to be dose- dependent. However, though the dose of radio frequency (RF) electromagnetic exposure described by the specific absorbing rate (SAR) on fixed rats has been relatively well-studied utilizing the numerical simulations, the dosimetry study of exposure on free rat is insufficient, especially in the cases of two or more free rats. Therefore, the present work focuses on the variation of SAR caused by the existence of neighboring free rat in the same cage. Here, infrared thermography was used to record the activity of the two free rats who lived in the same cage that mounted at the far-field region in the microwave darkroom for a duration of 48 h. Then, using image processing techniques, the relative positions and orientations of the two rats are identified, which are defined by three parameters, such as the relative distance (d), relative direction angle (α), and relative orientation angle (β). Using the simulation software XFdtd 7.3, the influence of d, α, and β on the whole-body average SAR (WB-avgSAR) of the rats exposed to 1.8 GHz electromagnetic wave was calculated and analyzed. Then, the average variation of WB-avgSAR of the two rats compared with that of a single rat within 48 h was calculated. The numerical simulation results showed that the relative posture position described by (d, α, and β) of the two rats affects their WB-avgSAR and leads to fluctuations at different positions. However, the variation rate of the 48-h-average WB-avgSAR was only 10.3%, which implied that the over-time average SAR of two or more rats can be roughly described by the WB-avgSAR of a single free rat, except when a real-time precise control of exposure dose is necessary. frontiersin.org

AI evidence extraction

At a glance

Study type

Exposure assessment

Effect direction

unclear

Population

Two free rats in the same cage

Sample size

Exposure

RF · 1800 MHz · 48 h

Evidence strength

Insufficient

Confidence: 78% · Peer-reviewed: yes

Main findings

Numerical simulations (XFdtd 7.3) indicated that the relative posture/position (d, α, β) between two free rats affects WB-avgSAR and causes fluctuations across positions. The 48-h-average WB-avgSAR variation rate for two rats compared with a single rat was 10.3%, suggesting time-averaged SAR for multiple rats can be approximated by that of a single free rat unless real-time precise dose control is needed.

Outcomes measured

Whole-body average SAR (WB-avgSAR) variation as a function of relative distance (d), relative direction angle (α), and relative orientation angle (β) between two free rats
48-h-average WB-avgSAR variation rate compared with a single free rat

Limitations

Dosimetry-focused numerical simulation study; no health/biological outcomes reported
Only two rats assessed
Exposure scenario described as far-field in a microwave darkroom; generalizability to other setups not stated

View raw extracted JSON

{
    "study_type": "exposure_assessment",
    "exposure": {
        "band": "RF",
        "source": null,
        "frequency_mhz": 1800,
        "sar_wkg": null,
        "duration": "48 h"
    },
    "population": "Two free rats in the same cage",
    "sample_size": 2,
    "outcomes": [
        "Whole-body average SAR (WB-avgSAR) variation as a function of relative distance (d), relative direction angle (α), and relative orientation angle (β) between two free rats",
        "48-h-average WB-avgSAR variation rate compared with a single free rat"
    ],
    "main_findings": "Numerical simulations (XFdtd 7.3) indicated that the relative posture/position (d, α, β) between two free rats affects WB-avgSAR and causes fluctuations across positions. The 48-h-average WB-avgSAR variation rate for two rats compared with a single rat was 10.3%, suggesting time-averaged SAR for multiple rats can be approximated by that of a single free rat unless real-time precise dose control is needed.",
    "effect_direction": "unclear",
    "limitations": [
        "Dosimetry-focused numerical simulation study; no health/biological outcomes reported",
        "Only two rats assessed",
        "Exposure scenario described as far-field in a microwave darkroom; generalizability to other setups not stated"
    ],
    "evidence_strength": "insufficient",
    "confidence": 0.7800000000000000266453525910037569701671600341796875,
    "peer_reviewed_likely": "yes",
    "keywords": [
        "dosimetry",
        "specific absorption rate",
        "SAR",
        "whole-body average SAR",
        "WB-avgSAR",
        "1.8 GHz",
        "radiofrequency",
        "rats",
        "numerical simulation",
        "XFdtd",
        "infrared thermography"
    ],
    "suggested_hubs": []
}

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

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