Can cellphones cause brain cancer?

The short answer: We don't know yet. Many experts agree that to date, there is no conclusive evidence that links cell-phone use to brain cancer, but that more research is needed. Last spring, results released from the largest and longest study on the topic essentially said the same thing. The 10-year survey of more than 12,000 people from 13 countries suggested a possible increased risk for glioma - a type of brain tumor - in heavy cell-phone users, but no overall increase in brain tumor risk. Investigators concluded more research was necessary on the effects of long-term mobile-phone use.

It often takes years or even decades between exposure to a carcinogen and the onset of a tumor, so it's possible not enough time has passed to detect an increase in cancer rates that can be directly linked to cell-phone use. Long-term studies are ongoing - one launched in Europe last year plans to track more than 250,000 cell-phone users over 20 to 30 years. Cell phones emit radio frequency (RF) energy, a low-level form of radiation. If you are concerned about potential health risks from your cell's radio waves, keep your phone off when you're not using it and follow these tips to reduce your exposure:

Use a landline when possible

Old-fashioned corded phones are best. The cordless kind use radio frequencies similar to those of cell phones, though their signals are generally less powerful.

Go hands-free

The more distance you place between your head and your cell, the better. That's because the antenna, the main source of RF energy, lives in the handset. Switching to speakerphone works, as do corded earpieces, which emit virtually zero waves.

Check your bars

The farther you are from a cell tower, the more energy your phone uses to get a good signal, which may increase your exposure to radio waves. Save calls for when you have strong service.

Let your fingers do the talking.

Text when you don't have much to say (and you aren't driving).

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