"If someone already has brain damage and then stimulates it with electromagnetic exposure from a cell phone, it could trigger something dangerous, " Volkow said.

CNN: Cell phone exposure increases brain cell activity

Many other factors that have been studied do not seem to affect the risk of breast cancer (dietary fat intake, cigarette smoking, past oral contraceptive use, exposure to electromagnetic fields).

FORBES: After 40 Years Of Research, What Do We Know About Preventing Breast Cancer?

The European Parliament was due to vote on new rules to limit exposure to powerful electromagnetic fields earlier this year.

BBC: Study into health impact of MRI

In 1997 the National Research Council issued a major report on the health effects of exposure to power frequency electromagnetic fields (EMF), such as those due to electric power lines.

FORBES: Should The FCC Re-Examine Cell Phone Radiation?