vehicle-treated=sham controls are given under dose/SAR=0

see Figures 3 and 4 for exposure pattern / schedule; Tables 2 (whole body) and 3 for exposure / dose (organs) (SAR)

Note that the dose regime is the following for each 2 h exposure. It is divided in 3 phases and the SAR value given for the dose groups is always the highest of the three, namely the one from phase I.

Phase I: time- and whole body average exposure [mW/g] 4.0 1.3 0.4 Sham

Phase II: time- and whole body average exposure [mW/g] 2.8 0.93 0.35 Sham

Phase III: time- and whole body average exposure [mW/g] 1.0 0.35 0.11 Sham

Detailed description from the manuscript: "All signals applied were compliant with the definitions of the GSM or DCS standards. The carrier frequency was set to the mid band of the up-link band, that is, 902 MHz for GSM and 1747 MHz for DCS. In each exposure session (duration 2 h), all exposure elements as they occur during usage of a mobile phone in the environment were delivered in three phases of 40 min duration each (Fig. 4). Each slot was modulated with a random code by a standard setting of the signal generator (Fig. 3). In the first phase, non-DTX mode (‘‘GSM Basic’’) was applied with the exposure condition as it occurs during continuous talking, that is, one active slot per basic frame, while every 26th basic frame was idle. This exposure constitutes the highest time-averaged exposure condition.

The second phase (‘‘GSM Talk’’) simulated a conversation, that is, a random change between the non- DTX (average time active: 2/3) and DTX (average time active: 1/3) modes. This signal provides the most coherent signal with strong amplitude-modulation component of 2, 8, and 217 Hz including their harmonics. The third phase (‘‘GSM Environment’’) simulated exposure during a conversation while moving in the environment. This included GSM features such as non-DTX, DTX, power control, and handovers etc. according to their statistical occurrence [Mertens et al., 2001]. The statistical parameters were derived from measurements performed by France Telecom [Wiart et al., 2001]. The condition provides a lower time averaged exposure but the largest variety of possible low frequency amplitude-modulation components. In each of the four or rather eight wheels, the tube-restrained animals received a different exposure: high, medium, low, and sham dose. Several pre-tests (902 MHz and 1747 MHz, continuous wave (cw) signals or a three-phase GSM/DCS signal exposure as used in this study) were conducted to confirm that the endpoints would not be affected at the highest dose levels [Kamlage, 2002]. In addition, the thermal threshold and breakdown levels were determined in a separate study [Ebert et al., 2005]. The latter revealed that the high dose level was close to, yet below, the thermal threshold.

The incident field was adjusted according to a numerically determined dose-weight function in order to maintain the same exposure independent of the animal’sweight/age. Table 2 shows the dose levels applied for each of the three phases. The maximum slot-averaged whole-body average exposure was the same for all three phases and approximately corresponds to the maximum local exposure during a telephone conversation. Table 3 provides the exposure levels of each organ relative to the whole-body average SAR values including absolute SAR uncertainty (k.2) and instant and lifetime averaged variations (k.1) of the exposure. These values were assessed using the methodology of Kuster et al. [2006]. The spatial peak SAR at 4 W/kg of 250 W/kg at GSM and 30 W/kg at DCS largely exceeds the

maximum spatial peak SAR during mobile phones usage ranging from 0.1 to 2 W/kg depending on phone type. The averaged absorption in the brain of the mice of 2.5 W/kg atGSMand 5 W/kg at DCS were considerable larger than the average human brain exposure and even as the maximum spatial peak SAR in the human cortex [Kuster et al., 2004]. The whole-body exposure as well as the specific organ SAR were several magnitudes larger than those of humans during phone or base station exposure. The envelope of the signal well simulated exposure conditions occurring during daily usage of GSM handsets."

B6C3F1 mice, male

HAWC