Workers suspected electromagnetic fields when more than 20 percent of the employees working in a basement office developed cancer, but tests showed the fields were weaker than those in an average home.
Jim Stout, Pacific Bell's safety director, said Monday the measurements make him doubt there is any connection between the cancers and electrical equipment in the building.But John Theriault, regional safety committee chairman for the Communications Workers of America, said he would remain suspicious until more extensive measurements are taken.
Michael Yost, a biomedical and environmental health scientist at the University of California, Berkeley, said "We just don't know."
Electromagnetic fields, or EMFs, are emitted by power lines, appliances, office equipment and anything else electrical. A 1990 draft report by the Environmental Protection Agency called the extremely low-frequency form of radiation "a possible, but not proven, cause of cancer in humans."
Yost ordered spot measurements of EMFs in the basement.
The measurements found magnetic fields in the office "are not unusual" and weaker than in the average home, Yost said.
But Yost said he could not rule out a link because measurement of six spots "wasn't an extremely thorough or systematic survey."