title: 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.
authors.affiliation: Department of Experimental Pathology and Tumor Biology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan. tshirai@med.nagoya-cu.ac.jp
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Shirai
authors.forename: Mayumi
authors.initials: M
authors.lastname: Kawabe
authors.forename: Toshio
authors.initials: T
authors.lastname: Ichihara
authors.forename: Osamu
authors.initials: O
authors.lastname: Fujiwara
authors.forename: Masao
authors.initials: M
authors.lastname: Taki
authors.forename: So-ichi
authors.initials: S
authors.lastname: Watanabe
authors.forename: Kanako
authors.initials: K
authors.lastname: Wake
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yamanaka
authors.forename: Katsumi
authors.initials: K
authors.lastname: Imaida
authors.forename: Makoto
authors.initials: M
authors.lastname: Asamoto
authors.forename: Seiko
authors.initials: S
authors.lastname: Tamano
mesh_terms: D040421:Cell Phone; D016543:Central Nervous System Neoplasms / Q000209:etiology* / Q000473:pathology; D004307:Dose-Response Relationship, Radiation; D004781:Environmental Exposure / Q000009:adverse effects*; D015994:Incidence; D008872:Microwaves / Q000009:adverse effects*; D009381:Neoplasms, Radiation-Induced / Q000209:etiology* / Q000473:pathology; D011829:Radiation Dosage; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012737:Sex Factors; D016019:Survival Analysis