The head of a prominent cancer research institute has warned his faculty and staff to limit cellphone use because of a possible cancer risk, The Associated Press reports.

Dr. Ronald B. Herberman, the director of the University of Pittsburgh Cancer Institute, notes that while the evidence about a cellphone-cancer link remains unclear, people should take precautions, particularly for children.

“Really at the heart of my concern is that we shouldn’t wait for a definitive study to come out, but err on the side of being safe rather than sorry later,” Dr. Herberman told The Associated Press.

Earlier this year, three prominent brain surgeons raised similar concerns while speaking on “The Larry King Show.” Their concerns were largely based on observational studies that showed only an association between cellphone use and cancer, not a causal relationship. The most important of these studies is called Interphone, a vast research effort in 13 countries, including Canada, Israel and several in Europe.

Some of the research suggests a link between cellphone use and three types of tumors: glioma; cancer of the parotid, a salivary gland near the ear; and acoustic neuroma, a tumor that essentially occurs where the ear meets the brain. All these tumors are rare, so even if cellphone use does increase risk, the risk is still very low.

On Wednesday, Dr. Herberman sent a memo to about 3,000 faculty and staff saying that children should use cellphones only for emergencies because their brains are still developing. He advised adults to keep cellphones away from the head and use the speakerphone or a wireless headset, he said.

“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 cellphone use,” he wrote in his memo.

To read my recent Well column that explores the data on cellphones and cancer, click here.