Well-ventilated schools show a reduced spread of COVID, but schools tend to choose the least expensive options when considering ventilation systems, according to a new report from the Centers for Disease Control and Prevention.
Released earlier this month, the report describes findings from a nationally representative survey of more than 1,600 K-2 schools. The results, drawn mostly from a subset of 420 of those schools, showed that schools are more likely to hold classes outdoors (73.6 percent), keep doors open (67.3 percent), and open up windows (67.2 percent) than they are to invest in more costly measures to prevent the spread of airborne illnesses, such as COVID-19, or unhealthy air particles.
Only 38.5 percent of schools invested in upgrading or replacing their HVAC systems. And 28.5 percent chose portable High Efficiency Particulate Air (HEPA) filtration systems for classrooms; 29.8 percent installed them in eating areas. The tendency toward low-cost measures was particularly true of schools with student populations in the mid-poverty range and those in rural areas.
The findings are notable because “HEPA filters are no less than 99.97 percent efficient at capturing viral particles associated with SARS-CoV-2" or COVID-19, said Jade Fulce, a public affairs specialist at the CDC. She said these filters were the least likely ventilation method to be used by rural schools in high-risk areas, such as the nurse’s office, isolation areas, or rooms where mask guidance was less likely to be followed.
Improved ventilation in schools has many other benefits besides reducing the spread of COVID-19. Better air filtration helps to reduce allergies and improve respiratory functioning, as well as improve student performance and decrease absenteeism according to experts.
Federal funds set up by organizations to improve ventilation in schools include:
- The U.S. Department of Education’s Elementary and Secondary School Emergency Relief Fund
- The Education Department’s Governor’s Emergency Education Relief Fund
- The U.S. Department of Health and Humans Services’ FY 2021 American Rescue Plan Funding Increase for Head Start Programs funds
- The CDC’s Epidemiology and Laboratory Capacity for Prevention and Control of Emerging Infectious Diseases Reopening Schools supplement.
Ventilation strategies differed based on the location of the school and poverty level of the families served. While all schools frequently reported using affordable strategies such as opening windows, city schools were the least likely to do so. CDC experts hypothesized this could be because of air and noise pollution or limitations of the building design, for example, classrooms with windows that cannot be opened.
"[Since] the specific ventilation strategies and combination of strategies a particular school should implement may vary by COVID-19 community level, seasonality, environment, building type, and well as other unique school characteristics, schools can work with ventilation experts to come up with a plan to improve ventilation that would be best suited for their specific setting,” Fulce said.
To reduce the spread of COVID, the CDC recommends public health officials focus efforts on supporting the schools least likely to report using costly ventilation strategies—rural schools, for instance, or those with moderate poverty levels—to ensure more equity.