AUSTIN (KXAN) – A new study shows more children are using smart phones and other mobile devices and they start young, with many children using mobile devices by their first birthday.

The survey of nearly 300 parents revealed 75 percent of four-year-olds have their own mobile device. Twenty percent of one-year-olds had their own tablet and about one in four parents admitted they use a mobile device to put their children to sleep.

But some scientists and doctors are now warning about potential dangers to children when it comes to extended exposure to radiation from cell phones. NBC News reports children are exposed to an exponentially greater amount of radio frequency than any adult will ever be in a lifetime.

Austin Neurosurgeon, Dr. Mark Burnett, with NeuroAustin, spoke to KXAN about what this new information means for parents.

“We all worry about that sort of thing,” said Burnett. “But at this point, there really is no hard and fast understanding of how cell phones can cause cancer in particular because the radiation isn’t strong enough to break apart DNA.”

Burnett also said the effects of exposure are different between adults and children.

“The structure of a child’s skull is just different than an adult, skulls are thinner and so if there is any radiation that comes through your cell phone that could be harmful, the concern is it can get through the brain and the skull and the neural tissue a little bit easier than it might an adult,” Burnett said. “You’re talking about something that we all use every day and now our kids are using every day over many, many years and so it’s sort of like smoking. We know smoking is bad but many years ago we didn’t know that it was exactly harmful for us and we just don’t want to find out down the road somehow that we’ve been doing something now that caused a future ill health effect for our kids.”

To lower radiation exposure for everyone, experts recommend people keep phones at least six inches away from the face. They also suggest using the speaker or earpiece when possible.