According to Swedish study results released in April, 2006, if you spend many years using your cell phone for at least an hour a day your risk of developing a brain tumor is 240% higher than a person who never uses one, writes Medical News Today.

The researchers found that even the location of the tumor, for extensive cell phone users over many years, tends to be on the side of the head where the phone is used.

The scientists examined cell phone use among 905 people who had a malignant brain tumor and compared them to a control group of 905 healthy people. All the volunteers were aged 20-80.

85 of the 905 people who had a malignant tumor were high users of cell phones) - they started using mobile phones a long time ago, and have used them a great deal, on average for about an hour a day. The team's definition of a extensive use means over 2,000 hours of cell phone use, spread over many years.