Another worker at a Boston-area hospital has been diagnosed with a brain tumor, the sixth to be identified among staff members who all worked on the same floor. The president of Mass General ...

All six staffers work or have worked on the fifth floor of, though an investigation found “no environmental risks.” ...

Five nurses have been diagnosed with brain tumors, and still others have health concerns, but the hospital says tests showed "there is not an environmental risk" to staff or patients.