The reality is, the way we've used phones and the amount that we've used phones has changed radically in the past five years. When phones were first marketed in the 1990s, it cost, for car phones, $3000 to buy a phone and the average person did not use it that much. They were very, very expensive.

Just a little bit of exposure to this pulsed digital signal, which is now a cellphone signal, could weaken membranes of the brain.

There's an increase in serious weight disorders from cellphone use. And people who don't sleep have serious other consequences for their health that can be associated with it. There may be as well increases in problems with their memory. And all of those things are not as sexy and don't demand as much attention as cancer, but they can be very, very important from a public health point of view.

Where people are using phones in rural areas their risk of brain cancer is higher than in urban areas.

A young child's brain has a thinner skull and the brain contains more fluid. The more fluid or fat in any material, the more it absorbs microwave radiation.

The average studies of cellphones and brain cancer have studied people who have used cellphones for five years or less. Sometimes eight years. Every study that has actually examined people who have used phones for 10 years or more, and is well designed, finds a 50 percent to an 800 percent increased risk. So that is why the Israelis, the Finnish, the French governments have all issued warnings.

We get dopamine in the brain when we like something a lot. Well, cellphones stimulate dopamine, too. So it really is the case that there are some people who are pretty addicted to these devices.