Among suggestions Dr. Ronald Herberman listed to limit exposure to electromagnetic radiation emitted by the devices were texting, shortening conversations and using headset or speaker phone options, the Pittsburgh Post-Gazette reported Wednesday.

"Recently I have become aware of the growing body of literature linking long-term cell phone use to possible adverse health effects, including cancer," Dr. Ronald Herberman told faculty and staff at the Pittsburgh Cancer Institute and the University of Pittsburgh Medical Center. "Although the evidence is still controversial, I am convinced that there are sufficient data to warrant issuing an advisory to share some precautionary advice on cell phone use."

Herberman said other countries have recommended limits on exposure, and public health officials in Toronto have advised young people to limit cell phone use.

While support for limited cell phone use may be growing, it isn't universal, the newspaper said.

Precautions are good, but "the bottom line, at this time, is that there is no conclusive evidence tying cell phone use to brain cancer," said Dan Catena, an American Cancer Society spokesman.