Chronic exposure to a 1.439 GHz electromagnetic field used for cellular phones does not promote N‐ethylnitrosourea induced central nervous system tumors in F344 rats

Abstract

The present study was designed to evaluate whether a 2 year exposure to an electromagnetic field (EMF) equivalent to that generated by cellular phones can accelerate tumor development in the central nervous system (CNS) of rats. Brain tumorigenesis was initiated by an intrauterine exposure to N-ethylnitrosourea (ENU) on gestational day 18. A total of 500 pups were divided into five groups, each composed of 50 males and 50 females: Group 1, untreated control; Group 2, ENU alone; Groups 3-5, ENU + EMF (sham exposure and 2 exposure levels). A 1.439 GHz time division multiple access (TDMA) signal for the Personal Digital Cellular (PDC), Japanese standard cellular system was used for the exposure of the rat head starting from 5 weeks of age, 90 min a day, 5 days a week, for 104 weeks. Brain average specific absorption rate (SAR) was 0.67 and 2.0 W/kg for low and high exposures, respectively: whole body average SAR was less than 0.4 W/kg. There were no inter-group differences in body weights, food consumption, and survival rates. No increase in the incidences or numbers per group of brain and/or spinal cord tumors, either in the males or females, was detected in the EMF exposed groups. In addition, no clear changes in tumor types were evident. Thus, under the present experimental conditions, 1.439 GHz EMF exposure to the heads of rats for a 2 year period was not demonstrated to accelerate or affect ENU initiated brain tumorigenesis.

Effects of gestational exposure to 1.95‐GHz W‐CDMA signals for IMT‐2000 cellular phones: Lack of embryotoxicity and teratogenicity in rats

“…Most epidemiological investigations, with only few exceptions, have disclosed no association between EMF exposure and brain tumor development. Experimentally, there are no data demonstrating that EMF exposure is a risk for brain tumor development [Adey et al, 1999[Adey et al, , 2000Zook and Simmens, 2001;La Regina et al, 2003;Shirai et al, 2005Shirai et al, , 2007. Epidemiologic studies have however indicated an association between childhood leukemia and exposure to extremely low frequency (ELF) magnetic field [IARC, 2002], which suggests that children might be more susceptible to radio frequency fields (RF) than adults.…”

Upregulation of Specific mRNA Levels in Rat Brain After Cell Phone Exposure

“…Hata et al (2005), studying the secretion of melatonin and serotonin from the rat pineal gland, found no changes either. One long-term study exposed rats for 90 min per day, 5 days per week for 104 weeks; this chronic exposure did not induce tumor growth in the rat central nervous system (Shirai et al, 2005). This study, although long term, did not evaluate early or subtle effects of exposure including changes in gene expression.…”

Recent Advances in Research on Radiofrequency Fields and Health: 2004–2007

“…Anderson et al (2004) observed no effect on brain tumor incidence in rats exposed for 24 mo to digital mobile phone signals at brain SARs of 0.16 or 1.6 W/kg. Shirai et al (2005) exposed normal and ethylnitrourea (ENU)-treated rats to 1.439 GHz pulsemodulated RF fields at brain-averaged SARs of 0.67 and 2 W/kg for 105 wk. Evidence indicated no differences in survival rates or incidence or numbers of brain and/or spinal-cord tumors in ENUtreated rats among the RF-exposed groups relative to the ENU-treated sham-exposed animals.…”