Space efficient system for whole‐body exposure of unrestrained rats to 900 MHz electromagnetic fields

Abstract

The aim of this study was to design, implement and analyze a space-efficient setup for the whole-body exposure of unrestrained Wistar rats to radiofrequency (RF) electromagnetic fields at 900 MHz. The setup was used for 2 years in a cocarcinogenesis study and part of it for 5 weeks in a central nervous system (CNS) study. Up to 216 rats could be placed in separate cages in nine different exposure chambers on three racks requiring only 9 m2 of floor area (24 rats per m2). Chambers were radial transmission lines (RTL), where the rats could freely move in their cages where food and drinking water was provided ad libitum except during RF exposure periods. Dosimetrical analysis was based on FDTD computations with heterogeneous rat models and was validated with calorimetrical measurements carried out with homogeneous phantoms. The estimated whole-body average specific absorption rates (SAR) of rats were 0 (sham), 0.4, and 1.3 W/kg in the cocarcinogenesis study and 0 (sham), 0.27, and 2.7 W/kg in the CNS study with an estimated uncertainty of 3 dB (K = 2). The instantaneous and lifetime variations of whole-body average SAR due to the movement of rats were estimated to be 2.3 and 1.3 dB (K = 1), respectively.

Whole-body exposures to radiofrequency-electromagnetic energy can cause DNA damage in mouse spermatozoa via an oxidative mechanism

“…For 1 W input to the aerial a maximum electric field of 94 V/m was measured 16 cm from the center, whereas in their slightly larger setup, Puranen et al . 23 measured a maximum electric field of 80 V/m at 15 cm from the center. The variation of E field with radial distance and the maximum electric fields in the two setups were found to be similar for the same power input.…”

“…During our irradiations the input RF power was 20 W, corresponding to an average SAR of 2.2 W/kg since the geometry of our irradiation system is very similar to that of Puranen et al . 23 .…”

“…Specifically, a dedicated waveguide machine (Fig. 1), similar to that developed by Puranen and colleagues 23 , was constructed to facilitate exposure of unrestrained mice to RF-EME at 905 MHz with a specific absorption rate (SAR) of 2.2 W/kg. Mice were exposed to RF-EME for 12 h per day, over a period of between 1 to 5 weeks and subsequently the testes and epididymides were collected to investigate the effects of RF-EME on spermatogenesis and sperm function.

Figure 1Waveguide instrument used to deliver whole-body RF-EME exposure.

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Development of computational small animal models and their applications in preclinical imaging and therapy research

“…Following this study, animal SAR values were calculated and reported for mouse, rat, rabbit, and pig under RF exposures of 800 MHz-2 GHz cellular phone electromagnetic fields. 22,36,44,54,[113][114][115][116][117][118][119][120][121][122][123] Dosimetry calculations were performed for the exposure of mice and rabbit to 2.45 GHz WiFi frequencies. [124][125][126][127][128][129] Fig.…”

Cylindrical Waveguide Electromagnetic Exposure System for Biological Studies with Unrestrained Mice at 1.9 GHz

“…These include those that are based on waveguides (Ho et al 1973;Guy et al 1975;Olsen et al 1984;Chou et al 1992;Ouardi et al 2008), radial transmission lines (Reinhardt et al 2007;Puranen et al 2009), anechoic chambers (Wilson et al 2002;Schelkshorn et al 2007;Wang et al 2008), GTEM cells (Bakos et al 2003) and reverberation chambers (Capstick et al 2008;Jung et al 2008). Among these types, waveguide-based systems have become popular for their advantages of having simple structures and providing good power efficiency.…”