SPRINGFIELD -- A troubling outbreak of mold is plaguing patients and workers at a key state mental health facility.

Some of the problems at Chester Mental Health Center have subsided with cooler weather. But in high humidity months, officials say a black, fuzzy mold grows on cinder block walls of bedroom and living unit hallways.

There is so much moisture that the floors become slippery, endangering the 280 residents and 550 workers.

"Patients and staff with allergy problems are experiencing health complications from this situation," notes an August memo calling for an emergency review of the air conditioning system. "This is a serious safety issue."

The facility, built in the mid-1970s, houses many of the state's most dangerous mentally ill residents. Many are unfit to stand trial or have been deemed not guilty for various violent crimes by reason of insanity.

A survey, estimated to cost $100,000, is underway. Officials are trying to pinpoint the source of the excessive moisture.

"Once the exact problem is located, a course of action can be determined," noted Dave Blanchette, spokesman for the state's Capital Development Board, which oversees state construction projects.

State Sen. Dave Luechtefeld, R-Okawville, whose district includes the mental health center, said the problems are troubling. "Obviously it is not a good situation," Luechtefeld said Wednesday.

"There shouldn't be conditions like that at any facility serving the disabled," said Deborah Kennedy, director of abuse investigations for Equip for Equality, a federally mandated organization that advocates on behalf of disabled Illinoisans.

"It is good that management now seems to be taking the problem seriously," said Anders Lindall, spokesman for the American Federation of State, County and Municipal Employees union.