Wifi in Schools

News reports from multiple sources indicate that a school in New Zealand has stopped using WiFi in classrooms for younger students, following the death of a child with brain cancer. Fortunately for those who rely on WiFi in schools, there is no evidence to suggest that WiFi causes cancer. The science simply does not support this.

There are two scientific principles at play. The first is the Skin Effect. Basically, it says that RF Radiation is more likely to affect the outside of a body than the inside of a body. In the case of humans, this means that people would be more likely to be affected by Skin Cancer and Bone Cancer rather than Brain Cancer, if there was actually any cancer being caused. You would also expect to see a lot more skin and bone cancers than brain cancer. I am not sure of the numbers, but I would guess that you would see at least 100 cases of WiFi induced skin caner and 10 cases of WiFi induced Bone Cancer in the head for ever case of Brain Cancer.

The numbers might be much higher, but if there was a causal link, you would expect hundreds or thousands of WiFi induced Skin and Bone cancers – something that we are simply not seeing.

The second principle is called the inverse square rule. This basically says that every time that you get double the distance from an antenna, the power you receive from it is cut by 75%. If it is 100 mW at 1cm, it becomes 25 mW at 2cm. It then becomes 6.25 mW at 4cm, 1.56 mW at 8cm and so on. It becomes 0.006 mW at 1.28m. This amount of energy from a ceiling powered access point is not going to hurt anyone.

But that is only half the equation. The other end of the link also transmits WiFi signals – the computers, phones and tablets. Since phones and tablets are portable, they are held by us. If there was a problem with radiation, given that they are help by us, it is likely that people would be getting lots of skin cancer, not brain cancer, and the skin cancer would be on their hands. And fortunately I have seen no such reports of cancer, and therefore I need to conclude that WiFi is safe.