Hmmm... those frequencies seem familiar?
"Research conducted at Stanford Research Institute, Menlo Park, California in 1974, showed that experimental exposure to high levels of microwave radiation, well above U.S. and Canadian guidelines killed rats within a matter of seconds to few minutes.
The higher the power density (intensity of the radiation) the more quickly the rats died. Of the four frequencies tested, the two most lethal frequencies (0.95 and 2.45 GHz) are commonly used for analog mobile phones (0.8 to 0.9 GHz); microwave ovens (2.45 GHz); and both digitally pulsed cordless phones and wireless routers (2.4 GHz). The least toxic of the frequencies was 4.54 GHz (near 5.0 GHz also used for some WiFi systems)."
From MagdaHavas.com --Explanatory Page & Link to Original Research Here.
Please note that this research refers to US frequencies in the 800 MHz band, also used by Telstra Next G in Australia. If you are using the GSM 900 P, E, or R specification such as in Europe, Asia or Australia, your downlink is at roughly 920 to 960 MHz, which is exactly the "most deadly frequency" specified by this research.