A new state health department study released Thursday is inconclusive about a link between the former Rocky Flats nuclear weapons plant and cancer rates among nearby residents.

Researchers reviewed the incidence of 10 kinds of cancer in 10 communities northwest of Denver near Rocky Flats. Twenty four years of data did find significant elevations of some types of cancer including lung, colorectal, esophagus and prostate. But residents of those communities also had higher smoking rates, which could explain those numbers.

"We are not seeing a signal in cancer incidence in those communities that really does suggest that theres a link," said Mike Van Dyke, the health department’s chief of environmental epidemiology.

Researchers found the incidence of six other types of cancers examined, including stomach and liver, mirrored the rest of the metro Denver area.

The nuclear weapons plant closed in the early ‘90s. Residents who lived near the plant have raised long-standing questions and concerns about high rates of illness.

Nick Hansen, an attorney representing a group called the Rocky Flats Downwinders, calls the study severely “flawed" because it doesn’t take into account in or out migration, which is key since the surrounding communities have seen so many new residents in the last few decades.

The group is waiting for additional health department studies of rare and thyroid cancers, and is calling for a new "independent" study.