Brain Cancer in Workers Employed at a Laboratory Research Facility.

Background: An earlier study of research facility workers found more brain cancer deaths than expected, but no workplace exposures were implicated.

Methods: Adding four additional years of vital-status follow-up, we reassessed the risk of death from brain cancer in the same workforce, including 5,284 workers employed between 1963, when the facility opened, and 2007. We compared the work histories of the brain cancer decedents in relationship to when they died and their ages at death.