One study claims that among people who have used a cell phone for more than 10 years and who hold the phone to alternate sides of the head, listening with both the right and left ear, there is a 20 % increased risk of brain tumor; for people who hold the phone only on one side, there is a 200 % increased risk for tumor. The same researches suggest that cordless home phones are worse: holding the phone on alternate sides has been associated with a 220% increased risk of brain tumor, while holding it on one side is associated with a 470% increased risk.~ Taken from a book titled "Dangerous or Safe?"
So, to reduce such exposure, you could:
While communicating using your cell phone, try to keep the cell phone away from the body as much as possible. Whenever possible, use the speakerphone mode or a wireless Bluetooth headset, which has less than one one-hundredth of the electromagnetic emission of a normal cell phone. Use of a hands-free earpiece attachment may also reduce exposures.
Avoid carrying your cell phones on your body at all times. You can also put it on "flight" or "off-line" mode, which stops electromagnetic emissions.
If you must carry your cell phone on you, make sure that the keypad is positioned toward your body and the back is positioned toward the outside so that the transmitted electromagnetic fields move away from you rather than through you.
When possible, communicate via text messaging rather than making a call, limiting the duration of exposure and the proximity to the body.
~Edited and taken from an article "Important Precautionary Advice Regarding Cell Phone Use" by Ronald B. Herberman, MD
Have you taken the steps needed?