well there are no solid evidence yet, some of the scientist claims that it was fine, the others claims that it was dangerous, the one that i knew is the radiation from cellphone is not good, because it can cause headaches, but developing cancer or tumor still got no evidence
The solid evidence is in the basic principals of wave/particle physics. No scientists even question whether or not cell phones are dangerous. If you have a banana for breakfast, that is technically one trillion (10^12) times more radiation than from cell phone signals. The energy of a wave = plank's constant * the frequency. 6.63x10^-34Js * 2x10^9Hz (2Ghz) = 1.2x10^-24 J. On the other hand, the Potassium 40 in your morning banana is a beta emitter. Beta emitters give off around 1x10^-12 J. Something else to keep in mind, FM Radio is around 100Mhz, compare that to Cellphones and the energy isn't much different. We all know Xrays are dangerous, well they start around 3x10^16 Hz. Visible Lights is 430-770 Thz (4.3-7.7x10^14 Hz). Cell Phones, Wifi, Bluetooth, things in the Ghz range are 100% completely safe. There is absolutely no reason based on science that non ionizing RF radiation is detrimental to human health.
Long story short, sunlight and bananas are doing trillions of times more damage to you than that call to mom.