A Nassau County school district found levels of mercury in gym floors and it's causing major concerns from parents as the school year is starting soon.

Anthony Mihailescu's son has spent multiple hours a day for years in the Glen Cove High School gym for wrestling.

He says a year and a half ago, they noticed significant behavior and health changes to him.

He recently learned that three school gym floors were tested and contained mercury.

"This may affect him for months, years, or maybe the rest of his life," says Mihailescu. "We immediately got our son tested and found that he was chronically exposed to the mercury vapor, and his levels were high in his blood." In a letter on the district website from Aug. 1, this was discovered in preliminary conversations to upgrade the middle school gym floor.

The district's environmental consultants and architect advised them that the existing floor may contain mercury. The district says they immediately conducted air-quality testing. Out of an abundance of caution, it decided to expand testing to include all similar flooring in the district.

The high school auxiliary gym tested above acceptable levels and was closed down over the summer.

The top and bottom gyms of the middle school tested well below accepted levels.

The district says it knows the news may cause concern and says its following all safety and environmental guidelines.

District officials decided to replace all three gym floors, but the work won't be done before the start of the school year. "I don't want anyone to be exposed to that, especially people with health conditions and stuff. That's really scary," says Lianna, a student. "I'm in shock honestly, speechless," says Jaclyn John, who's niece goes to the high school.

According to the tentative plan from the district, the hope is to have the high school gym reopen September 15 and they're hoping all gyms will be open by Oct. 1.

News 12 reached out to the district about potential health impacts to students but has not heard back yet. The district says it knows the news may cause concern and says it's following all safety and environmental guidelines.