Dr. Ronald Herberman, director of the institute and the University of Pittsburgh Medical Center, advised employees last month to limit exposure to electromagnetic radiation from cell phones, citing medical literature he conceded was "still controversial" but nevertheless warranted the advisory, the Seattle Post-Intelligencer reported Sunday.

University of Washington bioengineering Professor Henry Lai and a colleague reported more than 10 years ago that cell phones appeared to emit electromagnetic radiation sufficient to cause damage to brain cells that may lead to cancer, the Post-Intelligencer said. Lai said the study was followed by a telecommunications industry campaign to discredit and suppress research on potential health hazards of cell-phone radiation.

Lai stressed there is no direct evidence cell-phone use causes cancer.

Dr. Marc Chamberlain, a neuro-oncologist at the Fred Hutchinson Cancer Research Center in Seattle, told the newspaper the most alarming studies on the subject lack credibility, while credible studies have not documented a link.

Louis Slesin, editor of Microwave News, suggested the cell-phone industry has had a hand in making available data inconclusive.

"Industry doesn't like the data," said Slesin. "The problem is that we still don't know and the science has been heavily politicized."