Environmental testing has found mercury outside the Northport Middle School building, according to a letter sent out Monday by Superintendent Robert Banzer.
Three classrooms nearest the discovery will not be used, until further testing is completed, Banzer wrote.
The find is the latest round in the debate over the safety of the middle school. For years, some parents have complained about odors, illnesses and other problems. The Northport school board voted at a contentious meeting in November to perform soil testing in response to complaints.
The latest issue involves classrooms G51-G53. One of the classrooms had already been out of commission since Dec. 10 because of complaints. The board hired the environmental testing firm PW Grosser Consulting in December. Its inspection discovered the mercury fumes near a leaching pool.
Parents had previously called for sickout by teachers and students and demonstrated outside the building to demand more action by school officials.