SOUTH PORTLAND – A federal agency this week will review the air quality at a middle school as part of an investigation to determine if mold is causing health problems for school employees.

A four-person team from the National Institute for Occupational Safety and Health was spending Tuesday and Wednesday at Memorial Middle School. They will interview teachers and staff members, inspect the building and review past air quality tests.

School officials said they welcome the probe and hope it can provide a definitive answer on whether the 36-year-old building is making people sick.

“If we can get a second set of eyes to look at it, that is fine,” Superintendent Reginald MacDonald said.

South Portland is one of many districts in the state with mold problems in its schools.

Portland shut down an elementary school in 2001 because of mold, and several school districts this summer found mold in their buildings.

After mold was first detected at Memorial in November 2001, South Portland spent an estimated $400,000 to remove floors and walls and improve the ventilation system. Still, the district has had more than a dozen worker’s compensation claims for ailments blamed on mold.

David Brochu, director of building and grounds, said mold was again found this summer in the library and adjacent classrooms. He said the mold was removed and the air quality tested as acceptable.

But while school officials believed the mold problem had been addressed, some employees felt differently and contacted the National Institute for Occupational Safety and Health.

The institute is a research agency, not a regulatory agency like the Occupational Safety and Health Administration.

Last year it conducted 459 indoor environmental quality investigations like the one in South Portland, 101 of which were mold-related.