Wake County school leaders are standing by their decision to not install air purifiers in every classroom over the objections of some parents and N.C. State University scientists.
A parent advocacy group and members of N.C State’s environmental engineering department say that widespread installation of air purifiers in classrooms would be a good way to help protect students and teachers from contracting COVID-19.
But in a presentation Wednesday, district officials said the other steps taken to improve air quality in schools means they can limit the use of air filters to special education and PreK classrooms with unmasked students.
“Evidence that this is working is that a majority of our schools are having the 0 to 2 (COVID) cases weekly,” Jim Martin, chairman of the school board’s facilities committee, said. “If we were having substantial issues in our air systems, those numbers would not be at that level.”
Schools work to improve ventilation
Schools around the world have sought to improve air quality and ventilation as one way to reduce the risk of spreading COVID. The North Carolina Department of Health and Human Services listed several options on its Strong Schools Toolkit to improve ventilation.
Wake listed multiple steps it has taken, including:
▪ Upgrade MERV-13 filters installed in HVAC systems districtwide. These filters work at the building rather than the classroom level.
▪ Place portable HEPA (high-efficiency particulate absorbing) filtration units in classrooms with smaller groups of special education students who are unable to wear face coverings.
▪ Run HVAC systems for extended periods before and after the school day to increase air flow.
▪ Adjust outdoor air louvers and dampers and clean as needed based upon regular inspections and filter changes.
▪ Regularly inspect exhaust systems and maintain for proper operation.
“Maintenance has implemented the necessary and attainable initiatives to ensure that Wake County Public Schools’ HVAC systems are operating as efficiently as possible to ensure a safe and healthy learning environment for staff and for students,”said Nate Slavik, the district’s senior director of maintenance and operations.
Slavik said that the district used the time when schools were closed for in-person instruction to upgrade the ventilation systems and perform needed maintenance.
Benefits of air purifiers debated
Wake parents have been spending hundreds and thousands of dollars out of their own pockets to buy air purifiers for their children’s classrooms because the district won’t do so. Some parents argue Wake should step in to buy units for less-affluent schools whose parents can’t afford them.
Parents have cited how every New York City public school classroom is supposed to have two air purifiers this school year.
But Slavik cited the recommendations from the ABC Science Collaborative which say there’s no scientific data for putting air purifiers in classrooms where students are masked. The ABC Collaborative was formed by Duke University to help advise schools on COVID issues.
“It was determined that HEPA filtration would be beneficial in regional classrooms where students may have difficulty masking and where staff has to work in close proximity to unmasked students,” Slavik said.
This position was disputed in an op-ed piece penned by 10 members of N.C. State’s Department of Civil, Construction and Environmental Engineering. The scientists said that more recent studies have confirmed that aerosol-removing air filtration units reduce the risk of transmission in classrooms.
The N.C. State group argued that, despite the district’s ventilation upgrades, schools are not meeting targets for the number of times fresh air replaces indoor air per hour.
“Bridging this gap requires improved filtration, such as through the use of High Efficiency Particulate Air (HEPA) portable air purifiers,” the scientists wrote. “Properly sized HEPA purifiers can provide additional air changes, ensuring aerosols are removed at a rate that keeps our children safe.”
Kira Kroboth, a parent who founded the Facebook group WCPSS: COVID Safety & Support, said the district should be using some of its federal COVID relief money to purchase more air purifiers. She said having an air purifier in every classroom will still be useful after face masks are no longer required.
“We’re not going to wear masks forever,” Kroboth said in an interview Wednesday. “If it does provide 65% cleaner air and reduces that viral load in the air, and we’re not opening windows, that would be a good time to have them in there.”