A study launched by the U.S. Air Force’s Global Strike Command detected unsafe levels of a potential carcinogen at two facilities at a missile base in Montana, a release said Monday.

A team of bioenvironmental experts have detected unsafe levels of polychlorinated biphenyls (PCBs) at two locations at Malmstrom AFB, Montana, an active U.S. intercontinental ballistic missile base, after officials launched an investigation to address cancer concerns by missile community members, according to a release from the Air Force Global Strike Command Public Affairs office.

“Based on the initial results from the survey team, which discovered PCB levels above the cleanup threshold designated by law in two of our facilities, I directed Twentieth Air Force to take immediate measures to begin the cleanup process for the affected facilities and mitigate exposure by our Airmen and Guardians to potentially hazardous conditions,” Gen. Thomas Bussiere, commander of Air Force Global Strike Command, stated in the release.

Bussiere added the measures would stay in place until he is satisfied the missile community will be provided with a “safe and clean work environment.”