The question is, do you want to play Russian roulette with your brain?

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.

When the signal is weak, the phone is working more, you drain the battery faster, so only use a phone when the signal is weak in a true emergency.

The reality is, cellphones have to be used safely. They are today like cars and trucks - we can't live without them, but we certainly wouldn't give a car or truck to a toddler to drive. Why are we thinking it's perfectly okay to give a device that the World Health Organization has said is a "possible human carcinogen" to infants and toddlers, and for that matter, schoolchildren?

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.

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.