Some concern has been voiced about cell phone use and the increased risk of brain tumors. A team of researchers from the radiation and nuclear safety authority of Helsinki tested 1521 patients with glioma- the most common type of tumor.

3301 people with no cancer were also questioned as a control group. 92% of the glioma patients and 94% of the control group reported using mobile phones. Other factors like frequency and duration of use, years since first use and number of calls were also considered.

Researchers found no evidence suggesting increased risk of glioma from using digital or analogue phones. There may be a slightly higher risk of tumor growth if cell phones are used for ten or more years on the same side of the head, but no evidence has been found to verify this.