Distances between Rats in Reverberation Chambers Used for Large-Scale Experiments

Jeon, Sang Bong; 장욱,; Lee, Ae-Kyoung; Hyung, Choi Jin; 백정기,; Wang, Jianqing; 김동호,

doi:10.26866/jees.2021.21.2.148

Cited by 6 publications

(7 citation statements)

References 3 publications

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“…8 shows the placement of the rat models at stage 1 and stage 3, including the rack and water supply system. The distance between adjacent rats is determined based on the result in [16]. There are 30 pregnant rat models at stage 1, and 75 male rat models for weights of 450 grams or less and 70 male rat models for weights of 450 grams or more at stage 3.…”

Section: Placement Of Rat Modelsmentioning

confidence: 99%

Quantification of Exposure Level in a Reverberation Chamber for a Large-Scale Animal Study

et al. 2022

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The US National Toxicology Program (NTP) conducted a long-term carcinogenic and toxicity study with small animals on the effects of mobile phone radiation at 900 MHz and 1900 MHz, respectively, and showed an increase in incidence of malignant schwannomas in the heart of male rats at very higher exposure levels. To verify and clarify the NTP study results, Japan and Korea are conducting a joint study using the same reverberation chamber type exposure system as in the NTP study. The purpose of this paper is to derive a quantitative relationship between the electric field strength in the reverberation chamber and the exposure level, i.e., the mean whole-body averaged specific absorption rate (WBA _ SAR) of rats based on a large-scale finite difference time domain (FDTD) simulation. First, two FDTD simulation methods, one with a single plane wave incidence and the other with simultaneous plane wave incidence, were compared, and then the former method was adopted for convenience and saving calculation time. The derived quantitative relationship between the WBA _ SAR and the electric field strength required to achieve the WBA _ SAR consists of a one-dimensional approximation model which considers only the body mass of rats and a twodimensional approximation model which considers not only the body mass but also the number of rats. The two approximation models cover the entire two-year exposure period, and the exposure level in the two-year long-term exposure experiment is being well controlled. Moreover, unlike dosimetry in the NTP study, an uncertainty analysis of numerical dosimetry was performed in more details, and the combined standard uncertainty in the WBA _ SAR was found to be 16.1%.

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Section: Placement Of Rat Modelsmentioning

confidence: 99%

Quantification of Exposure Level in a Reverberation Chamber for a Large-Scale Animal Study

et al. 2022

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“…Therefore, in this study, the WBA‐SAR was calculated considering both the number of exposed rats and the weight of the rats. In the animal experiment, the E‐field strength has been determined according to the number of survived rats and their average weight [Jeon et al, 2021a,b; Ito et al, submitted].…”

Section: Levels Of Evidence; Before and After Peer Review Sex Neoplas...mentioning

confidence: 99%

“…The system was manufactured by Korea Shield System (KSS, Cheongju, Korea). Details of the RF‐exposure system have been reported previously [Jeon et al, 2021a,b]. Briefly, the system has two stirrers for each RC (KSS), a standard gain antenna [Telecommunications Industry Association [TIA], 1989], an E4438C signal generator (Agilent Technologies, Santa Clara, CA) operating in CDMA‐IS95A mode, a custom‐made signal amplifier (TMD Technologies, Hayes, UK), and four 20‐W fluorescent lamps that were mounted on the ceiling.…”

Section: Levels Of Evidence; Before and After Peer Review Sex Neoplas...mentioning

confidence: 99%

An International Collaborative Animal Study of the Carcinogenicity of Mobile Phone Radiofrequency Radiation: Considerations for Preparation of a Global Project

Ahn

Imaida

Kim

et al. 2022

Bioelectromagnetics

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Radiofrequency radiation (RFR) was classified as a “possible” human carcinogen in 2011, which caused great public concern. A carcinogenicity study by the National Toxicology Program (NTP) found Code Division Multiple Access—and Global System for Mobile Communications—modulated mobile phone RFR to be carcinogenic to the brain and heart of male rats. As part of an investigation of mobile phone carcinogenesis, and to verify the NTP study results, a 5‐year collaborative animal project was started in Korea and Japan in 2019. An international animal study of this type has two prerequisites: use of the same study protocol and the same RF‐exposure system. This article discusses our experience in the design of this global study on radiofrequency electromagnetic fields (RF‐EMFs).© 2022 The Authors. Bioelectromagnetics published by Wiley Periodicals LLC on behalf of Bioelectromagnetics Society.

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“…4. These 26 plane waves with two orthogonal polarization of transverse electric (TE) and transverse magnetic (TM) modes yield a total of 52 plane waves, which helps in the emulation of the good field uniformity of practical RCs [14], [16].…”

Section: A Simulation and Modelsmentioning

confidence: 99%

“…1 was analyzed. In our previous study [14], we observed two essential factors that significantly impact the SAR value: the polarization direction of an incident wave and cross-sectional area of the rat perpendicularly facing the propagation direction of an incident wave. Therefore, investigating the SARs of one rat with different postures is essential to provide basic information for various practical SAR analyses.…”

Section: B Sar Analysismentioning

confidence: 99%

Time-Weighted SAR in Rats for the Estimation of Practical RF Exposure in Reverberation Chambers

et al. 2022

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Herein, we present a new method for the calculation of the specific absorption rate (SAR) of rats (named time-weighted SAR) to practically consider the effect of the ever-changing movements of rats on their SARs. First, nine rats in separate cages were recorded for approximately 22 h, and the footage every 1 min was collected to obtain 1,307 still shots per rat. Next, five representative postures, which were classified according to the similarity of the still shots, were selected. Subsequently, the percentage of each posture was calculated by computing the number of still shots classified into the corresponding representative postures. Lastly, we demonstrated that although each rat exhibited relatively different and diverse movements during the observation period, the application of this percentage to the SARs of each posture resulted in very similar SAR levels among the rats. This indicates that the time-weighted SAR can be a good means of reflecting various behavior patterns of rats, as it can measure the total amount of real RF exposure more precisely and practically.INDEX TERMS Time-weighted SAR, rats, whole-body-average SAR (WBA-SAR), reverberation chamber, RF exposure

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Distances between Rats in Reverberation Chambers Used for Large-Scale Experiments

Cited by 6 publications

References 3 publications

Quantification of Exposure Level in a Reverberation Chamber for a Large-Scale Animal Study

Quantification of Exposure Level in a Reverberation Chamber for a Large-Scale Animal Study

An International Collaborative Animal Study of the Carcinogenicity of Mobile Phone Radiofrequency Radiation: Considerations for Preparation of a Global Project

Time-Weighted SAR in Rats for the Estimation of Practical RF Exposure in Reverberation Chambers

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