title: Study on potential effects of "902-MHz GSM-type Wireless Communication Signals" on DMBA-induced mammary tumours in Sprague-Dawley rats.
abstract: The aim of the study was to detect whether long-term exposure to "902-MHz GSM-type Wireless Communication Signals" ("radio-frequency (RF)-exposure") would affect 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumours in female Sprague-Dawley rats. Five hundred female rats were each given a single oral dose of 17 mg DMBA per kg body weight (bw) at an age of 46-48 days. Three groups of 100 animals each were RF-exposed (902 MHz; crest factor 8; pulse width=0.57 ms) from the next day onwards to normal whole-body averaged doses (expressed as specific absorption rate, SAR) of 0.4, 1.3 or 4.0 W/kg bw (low/mid/high-dose group) for 4h/d, 5d/week, during 6 months. A sham-exposed and a cage-control group remained without RF-exposure (<<0.01 mW/kg). Animals were weekly weighed and palpated for mammary tumours; all mammary glands were examined histopathologically. There were several statistically significant differences between RF-exposed groups and the sham-exposed group, as follows: All RF-exposed groups had, at different times, significantly more palpable tissue masses. There were fewer animals with benign neoplasms, but more with malignant tumours in the high-dose group. In addition, there were more adenocarcinomas in the low-dose group, more malignant neoplasms in the low- and high-dose groups, more animals with adenocarcinomas in the high-dose group, and fewer animals with fibroadenomas in the low- and mid-dose groups. The cage-control group had, when compared with the sham-exposed group, statistically significantly more palpable tissue masses, more benign and also more malignant neoplasms. The cage-control group had in most aspects the highest incidence and malignancy of neoplasms among all groups. None of the above findings in RF-exposed animals produced a clear dose-response relation and the responses of the cage-control group were either similar to or stronger than those of any of the RF-exposed group. The significant differences between the sham-exposed animals and one or more RF-exposed groups may be interpreted as evidence of an effect of RF-exposure. In the context of the results of the cage-control group, in the light of controversial results reported in the literature, and given the fact that the DMBA-mammary tumour model is known to be prone to high variations in the results, it is the authors' opinion that the differences between the groups are rather incidental ones.
authors.affiliation: Austrian Research Centers GmbH-ARC, Seibersdorf, Austria. robert.hruby@arcs.ac.at
authors.forename: Robert
authors.initials: R
authors.lastname: Hruby
authors.forename: Georg
authors.initials: G
authors.lastname: Neubauer
authors.forename: Niels
authors.initials: N
authors.lastname: Kuster
authors.forename: Michael
authors.initials: M
authors.lastname: Frauscher
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000633:toxicity*; D000818:Animals; D001835:Body Weight / Q000187:drug effects / Q000528:radiation effects; D005260:Female; D008321:Mammary Glands, Animal / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects*; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000209:etiology* / Q000473:pathology; D009929:Organ Size / Q000187:drug effects / Q000528:radiation effects; D011846:Radio Waves / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D047368:Tumor Burden / Q000187:drug effects / Q000528:radiation effects
chemical_list: D015127:9,10-Dimethyl-1,2-benzanthracene