Schools in the Long Island town of Glen Cove are replacing gymnasium floors following this month's startling discovery of mercury vapors emanating from old rubberized flooring.

Now, some parents of athletes who spend many hours in the gym say they are worried.

Mercury can cause neurological health effects, doctor says

Engineers upgrading the middle school gym this summer noticed the presence of mercury in polyurethane flooring installed decades ago. At room temperature, or when heated, mercury can release toxic vapors. The high school measured more than three times the allowable limit. Letters from the school district were immediately sent out to parents.

Dr. Jacqueline Moline, an expert in occupational medicine, is with Northwell Health's North Shore University Hospital.

"Over time, the body will get rid of the mercury," Moline said. "The type of mercury that is in gymnasiums is going to be mercury vapor, so the health effects related to this are predominately neurological."

CBS News New York has covered this issue in recent years in the Tri-State Area. Discovering gym floors that used mercury back in the 1960s to keep the material flexible, a school in Philadelphia showed our CBS affiliate just what it looks like to tear up and rebuild. That type of remediation is what schools in Glen Cove are doing.

The gym floor removal is completed and new installation is underway at both schools in Glen Cove, with mandatory air quality testing.

"Because they have taken care of this now, we know it's not going to be an ongoing issue," Moline said.

Schools open in Glen Cove next week. The district says with ventilation and new floors, students will not be at risk. The new floors will be ready in the high school in mid-September and in the middle school by Oct. 1.

Glen Cove High wrestler quits due to mercury issue

Anthony Mihailescu's son, Mateo, is a skilled wrestler at Glen Cove High School, but is giving up the sport after his doctor measured higher-than-average mercury in his blood.

"We took him right to the pediatrician," Mihailescu said. "Sadly, I do believe the kids in this gym, they were all being poisoned little by little. It has been a difficult time dealing with all these chronic symptoms."

He said he is pleased the schools are making the fixes, but, despite doctor assurances, he worries for his son's behavioral and health changes.

"Unfortunately, I feel like the damage is done," Mihailescu said.