EMF Health-effects Research

Study on potential effects of "902-MHz GSM on DMBA-induced mammary tumours in Sprague-Dawley rats

Hruby R, Neubauer G, Kuster N, Frauscher M

Mutat Res. 649(1-2):34-44, 2008

Study on potential effects of "902-MHz GSM-type Wireless Communication Signals" on DMBA-induced mammary tumours in Sprague-Dawley rats .

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 17mg DMBA per kg body weight (bw) at an age of 46-48 days. Three groups of 100 animals each were RF-exposed (902MHz; crest factor 8; pulse width=0.57ms) from the next day onwards to normal whole-body averaged doses (expressed as specific absorption rate, SAR) of 0.4, 1.3 or 4.0W/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 (<<0.01mW/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. 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.

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