It's uncertain how many school gymnasium floors in New Jersey are emitting a level of mercury vapor that's unsafe for the students and adults who come in contact with them daily.

While new guidance from the state aims to get a better idea of the problem's reach and help schools determine whether their rubber-like gym floor is cause for concern and may need to be removed, a coalition of healthy-school advocates believes the update falls short in a number of areas.

The floors in question have been getting installed since the 1960s — they contain a mercury catalyst that, in the right conditions over time, can cause mercury vapor to seep out from cracks. Installation of this floor type has been documented as recently as 2006. Several contaminated floors have been spotted and removed in New Jersey over the past couple years.

The problem is, a floor's date of installation, and even the safety data sheets that accompany the floor, are not determining factors in identifying which floors are potentially dangerous. And even if a floor is found to be laced with mercury, it's not a given that the floor ever has or will emit a dangerous level of mercury vapor.

"Part of our recommendation has been and continues to be that they conduct a statewide survey of rubberized floors," said Heather Sorge, campaign organizer for Healthy Schools Now. "Our staff and our children, our students should not be in an environment where they're being exposed to mercury vapor."

The Department of Health guidance document, released Feb. 6, does not call for a full assessment of the hazard, but advises school districts to conduct inspections of their poured-polyurethane floors. A bulk sample of the flooring may have to be collected in order to determine the presence of mercury, the document notes. If any concentration of mercury is detected the DOH recommends sampling of the indoor air to evaluate vapor levels.

Airborne mercury levels can be managed by active ventilation and temperature control, the document says. But removal of the floor may be necessary.

Over the 2019 summer, the Schools Development Authority implemented a rule that ensures no future projects include floors that contain the mercury catalyst. The authority, which funds and manages construction and renovation of school in 31 New Jersey districts, announced it will be requiring an additional certification from manufacturers that can guarantee a mercury-free product.

"We'd like to see the state, of course, follow suit on that," Sorge said.

Healthy Schools Now has identified eight concerns it has with the state's updated guidance. For one, the group claims the state's maximum allowed contaminant level is too high. The group notes the guidance does not mention what should be done with any furnishings or equipment that have come in contact with a mercury-laced floor. The group also points out there is no public database to track which schools have tested, along with results.

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Contact reporter Dino Flammia at dino.flammia@townsquaremedia.com.