Wi-Fi and health
Wireless communication uses electromagnetic radiation. Research into the possible health impact of this radiation has been ongoing for many years. It has been shown based on this research that electromagnetic radiation can cause thermal effects when the radiation intensity is high enough. Thermal effects, however, do not apply with regard to wireless applications as we currently use them because the radiation intensity is too low.
Wi-Fi radiation level
An AP may have a typical maximum radiated power of 100 mW or 20 dBm. This, however, is not the actual radiation that is derived from the device, but the value that we use to make theoretical calculations. The signal that is received by a device (laptop, smartphone, etc.) is typically of the order of magnitude of -65dBm to -70dBm in a good network. This means that the strength of the signal is approximately 0.00000001 mW. This is not enough to even heat a glass of water!
Europe has defined exposure limits that are recommended for member states. These limits have been set by the ICNIRP (International Commission on Non-Ionizing Radiation Protection), an international organisation of independent scientific experts. The limit for Wi-Fi (> 2100 MHz) has been set at 61 V/m. This value already includes a safety factor of 50.
On average, a maximum load of 0.15 V/m is measured at 2 metres from a Wi-Fi transmitter, therefore, 400 times lower than the limit! The corresponding SAR (Specific Absorption Rate) is 5x10-7 W / kg ( 0.0000005W / kg). The effect threshold for these high frequencies is 4W/kg according to experts. If the radiation level is even higher than this value, our body cannot discharge the additionally generated heat, which could potentially lead to exhaustion or a stroke.