A recent survey collected information from U.S. K-12 public schools. It asked about the ventilation improvement strategies schools are using. The goal was to understand what steps schools are taking, but the survey did not test how effective these steps are.
The survey simply reported which strategies schools said they were using. It did not measure whether these strategies actually reduced COVID-19 cases or improved air quality in classrooms. No safety concerns or problems were reported in this basic survey.
It is important to be careful with this information. This was just a report of what schools said they were doing. It does not prove that these ventilation strategies work to prevent illness. Readers should see this as a simple snapshot of school practices, not as evidence of what works best.