Two exposure systems, one for each frequency, were located in separate rooms. Each system consisted of a signal generation unit, control and monitoring unit, and four "Ferris wheel" exposureunits, one for each dose level (high, medium, low, and sham). The "Ferris wheel" concept developed by Balzano et al. [2000, publication 7306] was adopted and optimized for this study.
Each wheel, enabling exposure of up to 65 animals, consisted of two parallel, circular, stainless steel metal plates, 117 mm apart, with a conical (GSM) or bi-conical (DCS) antenna in their center, and stainless steel poles forming a short-cut of the cylindrical cavity at a radius of 755 mm. The animals, restrained in tubes similar to those used and approved for inhalation studies, were positioned at a radius (center of wheel to center of tubes) of 700 mm for GSM and 670 mm for DCS. In order to maintain a symmetrical load, missing animals were replaced by conical plastic tubes filled with 36 ml of liquid simulating the dielectrical parameters of muscletissue. Higher modes were reduced by dielectric bricks between the animals at 902 MHz. Details of the setup and dosimetry are provided in Ebert et al.  (in preparation).
Male or female mice were each randomized by weight into 9 treatment groups: 2 x 4 RFdose groups (incl. sham) and one untreated cage control group. Loading and unloading of the exposure wheel was done first in/first out resulting in an additional restraint time of up to 32 min for each mouse. The study was performed blind to all scientists involved.
The maximum slot-averaged whole-body exposure (peak SAR level) was the same for all three phases; however, the resulting average SAR level varied: 100% (GSMBasic),70% (GSM Talk), and 26% (GSM Environment). These values have been averaged over 2 years.
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Report of final results regarding brain and heart tumors in Sprague-Dawley rats exposed from prenatal life until natural death to mobile phone radiofrequency field representative of a 1.8 GHz GSM base station environmental emission.
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