The Air Force has detected unsafe levels of a likely carcinogen at underground launch control centers at a Montana nuclear missile base where a striking number of men and women have reported cancer diagnoses.

A new cleanup effort has been ordered.

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.

Unsafe levels of a carcinogen have been discovered at a nuclear missile base in Montana after the area experienced a spike in cancer case numbers, the Air Force Global Strike Command announced Monday.

A carcinogen is a “substance, organism or agent capable of causing cancer,” a category that includes naturally occurring things like UV rays or those created by human production, like cigarette smoke, according to the National Human Genome Research Institute.