How do cell phones affect young brains? Điện thoại di động ảnh hưởng não thế nào?

Cell phone safety warnings are generally designed for a large man with

a big head who talks less than half an hour a day.

The average toddler's head, however, weighs about half as much and is

far more susceptible to the microwave radiation the phone emits, said

environmental health expert Devra Lee Davis, founder of the

Environmental Health Trust, which campaigns for safer cell phone use.

As the debate over cell phones and cancer continues to rage, concern

is growing over the effects of the phones — as well as devices such as

the iPad — on children.

A recent study published in the Journal of the American Medical

Association found that pressing a cell phone to the ear for 50 minutes

altered the brain activity in 47 adult volunteers.

The study doesn't answer the million dollar question: whether the

change in brain activity causes any harm.

The wireless industry group says no research has proven cell phones to

be dangerous.

The National Cancer Institute, meanwhile, says there is no consistent

link between cell phones and cancer.

But the NCI also notes that there's currently no data on cell phone

use and risk of cancer in children and that children may be at a

greater risk because their nervous systems are still developing at the

time of exposure.

Meanwhile, cell phone use by children and adolescents is increasingly

rapidly.

Experts worry that children's brains, encased in a thinner skull, may

be more vulnerable to the effects of the radiation emitted by the

phones.

Dr. Nora Volkow, the lead author of the JAMA study, said modeling

studies have shown that a child's brain would absorb more radiation

than those of adults. But Volkow said she's unaware of studies that

have looked at the different developmental effects.

Some studies have suggested that the radiation can cross or affect the

entire brain of children, who are still developing, versus a

particular area in adults," said Dr. Stephanie Wagner, co-medical

director of the neuro-oncology program at Indiana University Health

and the IU Simon Cancer Center in Indianapolis.

But studies looking at the effects of electromagnetic radiation in

children and the risk of epilepsy and behavioral problems such as

attention deficit disorder and aggressive behavior showed conflicting

results, Wagner said.

Still, why take a chance, Volkow said.

She suggested that parents "teach their children to use their cell

phones with a wired earphone and/or use the speakerphone mode and to

avoid putting their cell phones directly on their ear."

jdeardorff@tribune.com



Concerned?



If so, try these tips, starting with the most drastic, to limit

exposure.

•Avoid white noise baby apps. Some children are falling asleep to

white noise played from iPhones or Blackberries under their pillows.

But the phones must stay on for the app to work. "A cell phone is a

two-way microwave radio," said Davis. "That means infants stay asleep

with their brains being radiated by the phones all night long."

•Don't let toddlers or young children use cell phones. Teenagers

should limit use to head sets or texting to keep the antenna away from

the brain, said Wagner. Or shift the phone between ears.

•Review SAR levels. The Specific Absorption Rate (SAR) is a measure of

the amount of radio frequency (RF) energy absorbed by the body when

using the handset. Before you buy your child a phone, search the

government's cell phone database (fcc.gov/cgb/sar).

•Follow the "one-inch" rule. Most cell phone manuals advise holding

the phone "at least one inch" away from the head.

•Don't carry a cell phone on your body. Place the phone inside a bag

or some type of holster; this will help block the radiation from

reaching the body.

•Limit phone use when the signal is weak. The radiation increases as

the device searches for a signal.