Despite additional federal funding, U.S. schools reported that they were most likely to rely on low-cost strategies to improve ventilation to slow the spread of the coronavirus, according to a study published Tuesday by the Centers for Disease Control and Prevention.
The measures include holding activities outside, opening doors and windows, and inspecting existing heating, ventilation and air conditioning systems, the study said.
Only about one-third of public schools reported taking costlier steps such as replacing or upgrading their HVAC systems. Fewer than one in three said they used high-efficiency particulate air (HEPA) filtration systems in classrooms and cafeterias.
Schools that serve children in the poorest American communities were slightly more likely to have replaced or upgraded HVAC systems than those serving communities with medium levels of poverty, the study found. Almost half of schools serving the poorest communities — and close to half of schools serving the wealthiest communities — had replaced or upgraded their HVAC systems, compared with only one-third of schools with medium levels of poverty. The poorest schools were also more likely to have inspected and validated their HVAC systems than schools with medium levels of poverty.
The authors of the C.D.C. report suggested that while schools in wealthier areas may have already had resources to upgrade their systems, schools in high-poverty areas might have more experience accessing and using federal funds for such purposes.
Thirty-five percent to 44 percent of the schools in the poorest communities reported using HEPA filtration systems in spaces where children eat and in classrooms and high-risk areas, and 36 percent to 50 percent of schools serving communities with low poverty levels reported using HEPA filters in those areas.
By contrast, only one in four or five schools serving communities with medium levels of poverty reported using HEPA filters in those places.
The study was based on the findings of a nationally representative sample of 420 K-12 public schools, using data gathered between Feb. 14 and March 27 from the National School Covid-19 Prevention Study. The sampling framework consists of public schools from all 50 states and the District of Columbia; it is a web-based survey distributed to school administrators.
Only 26 percent of schools that received the survey in February and March responded, however. The percentage of students eligible for free or discounted meals was used to determine the community poverty level of each school.
Location also was correlated with measures taken to improve ventilation: Rural schools were less likely to use portable HEPA filtration systems than schools in cities and suburbs.
Schools in cities, on the other hand, were less likely to open windows than rural, suburban or town schools, possibly because of concerns about noise and air pollution (some may also have windows that do not open). City schools were also less likely to use fans to increase the movement of air when they did open windows.
“Additional efforts might be needed to ensure that all schools successfully access and use resources for ventilation improvements,” particularly schools in rural areas and those with medium levels of poverty, the authors wrote.