I saw an episode of Dr. Oz a few years ago that talked about an adolescent female in middle or high school who always kept her phone turned on and tucked away in the cleavage of her bra. She developed breast cancer in the exact same spot where her phone was kept.

I couldn't get the video to load in this link but maybe you can.

http://www.doctoroz.com/episode/why-you-should-keep-your-cell-phone-out-your-bra