All radiofrequency waves used in modern telecommunications like 3G, 4G, WiFi and WIMAX are too weak in energy to cause any harm, having only a fraction of the energy of sunlight. International bodies like the ICNIRP and national regulators in the US and UK have determined that 3G, 4G and WiFi devices are safe based on the low energy levels of the radiofrequency waves they use.

1. Are 3G, 4G and the other new radio
technologies safe?
All radiofrequency waves used in modern
telecommunications and TV/Radio broadcasting,
including WiFi, WIMAX, 3G, 4G, etc. are just too weak in
energy to have any adverse health effects at all.
Radiofrequency waves have one-thousandth to one-
millionth of the energy of sunlight or the light emitted by
a bulb, being in the milli Electron Volt range. The
International Commission on Non Ionizing Radiation
Protection (ICNIRP) & the US Food & Drug Administration
(FDA) & USA Federal Communications Commission FCC
have stated that 3G, 4G, Wi-Fi devices are safe. So has
the UK Government's Advisory Group on Non Ionizing
Radiation Protection.