The main problem is that it’s almost impossible to prove that WiFi does not affect health. You can only conduct tests to show that it does. No such evidence currently exists.
The test of WiFi vs Mobile phone masts is a ridiculous one. The level of radiation from a mobile phone.. held around 5cm from your head is so vastly greater than that of the mast as to make the mast’s radiation insignificant at realistic distances.
A 1m distance from a WiFi hotspot is again a ridiculous test, if you take the distance up to around 2m (which is much more realistic), then by the law of square, you get about a quarter of that radiation, so making it less than a phone mast that’s 100m away.

Informative article. The Wi-Fi technology has adverse effects on health so one should be aware about it. It causes chronic diseases like cancer and genetic disorder like damage to DNA etc.
Pacific Hills Treatment Center´s last blog ..Study Shows How the Subconscious is Related to Drug Addiction

When we have conducted measurements in schools, typical exposures from wi-fi are around 20 millionths of the international guideline levels of exposure to radiation. As a comparison, a child on a mobile phone receives up to 50 per cent of guideline levels. So a year sitting in a classroom near a wireless network is roughly equivalent to 20 minutes on a mobile. If wi-fi should be taken out of schools, then the mobile phone network should be shut down, too – and FM radio and TV, as the strength of their signals is similar to that from wi-fi in classrooms.

I have another data to share with you all. The emissions from wireless networks are very similar to those from mobile phone base stations in terms of frequency and signal modulation. Many published reports have shown ill-health affects apparently associated with living and working close to mobile phone masts. In a Latvian study of 966 children, motor function, memory and attention were significantly worse in the group exposed to radiation from a pulsed radio location station. The exposure levels were low, but similar to those that children in classes with wLANs will be exposed to.