5.8ghz radiation is no more hazardous than the 2.4ghz radiation used in microwave ovens, and for the same reason: both are non-ionizing.  This limits their interaction with human cells to heating effects.  Fortunately this is very obvious and immediate, and is why cellular communications are limited to much lower power levels than microwave ovens. The reason they use 5.8ghz in the original article is likely tied to the wavelength, which determines the focal depth of the heating effect. TLDR: If you dont feel a burning sensation of heat, non-ionizing RF isnt at a high enough power level to harm you.