Effect of cell phone radiofrequency radiation on body temperature in rodents: Pilot studies of the National Toxicology Program's reverberation chamber exposure system

Abstract

Radiofrequency radiation (RFR) causes heating, which can lead to detrimental biological effects. To characterize the effects of RFR exposure on body temperature in relation to animal size and pregnancy, a series of short-term toxicity studies was conducted in a unique RFR exposure system. Young and old B6C3F1 mice and young, old, and pregnant Harlan Sprague-Dawley rats were exposed to Global System for Mobile Communication (GSM) or Code Division Multiple Access (CDMA) RFR (rats = 900 MHz, mice = 1,900 MHz) at specific absorption rates (SARs) up to 12 W/kg for approximately 9 h a day for 5 days. In general, fewer and less severe increases in body temperature were observed in young than in older rats. SAR-dependent increases in subcutaneous body temperatures were observed at exposures ≥6 W/kg in both modulations. Exposures of ≥10 W/kg GSM or CDMA RFR induced excessive increases in body temperature, leading to mortality. There was also a significant increase in the number of resorptions in pregnant rats at 12 W/kg GSM RFR. In mice, only sporadic increases in body temperature were observed regardless of sex or age when exposed to GSM or CDMA RFR up to 12 W/kg. These results identified SARs at which measurable RFR-mediated thermal effects occur, and were used in the selection of exposures for subsequent toxicology and carcinogenicity studies. Bioelectromagnetics. 39:190-199, 2018. © 2018 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.

Effect of Exposure to a Radiofrequency Electromagnetic Field on Body Temperature in Anesthetized and Non‐Anesthetized Rats

“…In this study, we administered 400 mg/kg chloral hydrate intraperitoneally to anesthetize and immobilize the rats for 3 h. This dose ensured gentle emergence from anesthesia. The body temperature of anesthetized animals may be affected by the ambient temperature, age, disease, pregnancy, heart rate, and body size and type [Aydin et al, ; Kim, ; Wyde et al, ].…”

“…The anesthetized 339 g rats were also more vulnerable to RF exposure than the 225 g rats. Indeed, larger rats are reportedly more sensitive to RF exposure‐induced increases in body temperature than the smaller rats [Wyde et al, ]. The smaller surface‐to‐mass ratio of large rats is advantageous at low temperatures, and the reverse is true for small rats [Riesenfeld, ].…”

“…Also, 1 h of exposure to a 1,439‐MHz time‐division multiple access fields at a brain‐average SAR of 7.5 W/kg (peak SAR of 11 W/kg or whole‐body average SAR of 1.7 W/kg) did not alter the body temperature in rats, but such exposure at a brain‐average SAR of 25 W/kg (peak SAR of 39 W/kg or whole‐body average SAR of 5.7 W/kg) raised the body temperature by 2 °C [Yamaguchi et al, ]. However, in another study, exposure to an EMF at an average of 4 W/kg whole‐body SAR did not significantly alter the body temperature [Kim et al, ; Paik et al, ; Wyde et al, ].…”

Evaluation of the genotoxicity of cell phone radiofrequency radiation in male and female rats and mice following subchronic exposure

“…Briefly, in pilot studies, body temperatures were monitored using subcutaneously implanted temperature chips (Wyde et al ). Both young and older animals were tested for the possibility of thermal effects from radiation.…”

“…Animals were housed inside the reverberation chambers and exposed to RFR for a total of 9 hr 10 min per day in 10‐min on/off cycles (over the course of an ~18 hr period) at frequencies with modulations being used in cellular networks (Capstick et al ). In addition, the exposure levels selected for this study were based on the results of previously conducted dosimetry studies and thermal pilot studies that demonstrated no measurable hyperthermia in rats and mice at the exposure levels chosen for this study (Gong et al ; Wyde et al ).…”