Across the country, K-12 schools are starting their next year of classes in the middle of a COVID-19 surge. As the BA.5 Omicron subvariant drives thousands of reinfections, schools have largely put aside safety measures like mask requirements and physical distancing.
In response, some parents and experts are trying to improve ventilation in schools, since better air quality in buildings can reduce COVID-19’s spread and even improve other health outcomes. But, despite readily available resources—including millions of dollars in funding from the federal government—many schools have not invested in upgrading their air quality.
“We know that ventilation is important to reduce the transmission of SARS-CoV-2,” says Dr. Catherine Rasberry, a scientist in the U.S. Centers for Disease Control and Prevention (CDC)’s Division of Adolescent and School Health. Ventilation is highlighted throughout the CDC’s guidance for safe in-person learning during the pandemic. Improving it could cut down on school outbreaks and the interruptions they pose to families, as well as mitigate the risks of MIS-C and Long COVID in children—two long-term conditions that can result from a COVID-19 infection.
Having good indoor air quality is also connected to a wide variety of other student health metrics that have nothing to do with COVID-19. “Decades of scientific research show when you improve indoor air quality, you improve student health, student thinking, and student performance,” says Joseph Allen, an air quality expert at Harvard’s T. H. Chan School of Public Health. Improvements range from fewer asthma attacks and allergy symptoms to better scores on reading comprehension tests, he says.
What good air quality means
Tony Colaneri, a parent in the Chicago suburb of Evanston who has campaigned for better ventilation in his children’s schools, compares cutting down on COVID-19 spread to reducing cigarette smoke. “Imagine that someone was smoking a cigarette on the other side of the room,” he says. In response, you might open windows, run fans, and put a portable air filter next to the smoker; the same measures can take the coronavirus out of the air.
Allen and other experts recommend that classroom ventilation meets the threshold of six air changes per hour, meaning new, clean air is circulating through the room every ten minutes. While the CDC does not issue guidance for this metric, several states have recommendations ranging between two and six air changes per hour.
“Really, you want to aim for 12 air changes per hour,” says Devabhaktuni Srikrishna, a San Francisco school parent and infectious disease researcher who runs the website Patient Knowhow, which compiles recommendations on high-quality masks, ventilation, and other COVID-related topics. “It’s the number used in hospitals for airborne infection isolation rooms for the last 20 or 30 years.”
To improve their air change rates, schools can use low-cost options, like opening windows and adding portable air filters. They can also upgrade or replace HVAC systems — a higher-cost strategy, but one that may be more valuable in the long-term, Allen says. These and other measures are outlined in a July report by Allen and other members of the Lancet COVID-19 Commission Task Force, a group of interdisciplinary experts collaborating to research pandemic solutions.
Students can even build portable air cleaners themselves. One popular model, the Corsi-Rosenthal box, can be built for under $100. These DIY boxes can perform just as well as expensive air cleaners, says Krystal Pollitt, an epidemiologist and environmental health expert at Yale University. Engineers at 3M, the company which produces the filters commonly used for these boxes, verified that the design is effective.
But first, students and teachers might need to convince school administrators that poor air quality is a problem. Last spring, three high school seniors at Franklin Learning Center, a public school in Philadelphia, studied their school’s air quality for a senior project. Using air monitors, they found “significantly high levels of carbon dioxide and humidity in classrooms,” says Cianni Craig, one of the students. These levels suggest that the air quality and ventilation are poor, which increases the risk of COVID-19 transmission and other possible health issues that “interfere with a student’s education,” she says.
After Craig and her classmates shared their findings at a school board meeting, school leaders dismissed their data, questioning whether their DIY methods were effective, says Jessica Way, a teacher at Franklin Learning Center who worked with the students on their project. But the students didn’t give up: they sent their work to the Philadelphia teachers union, local politicians, and journalists. Eventually, the district’s environmental office replicated the student’s research, confirming that their school’s ventilation needs some serious upgrades.
Why schools struggle with cleaner air
Major federal funding is available for schools to improve their air quality, thanks to the American Rescue Plan. But many schools haven’t done resource-intensive upgrades, according to a June report from the CDC.
In a national survey of 420 public schools, the majority reported using cheaper strategies like opening windows and moving activities outside. Only 39% reported replacing or upgrading school HVAC systems, and 28% reported using portable air filters. The CDC is working to better publicize federal resources for costly upgrades, says Rasberry, a lead author on the study.
School leaders need to learn more about air quality issues in order to understand how important they are, experts say. Even if an administrator recognizes the value of better ventilation, they likely need to hire an HVAC expert to examine existing building systems, then vet that expert’s recommendations and evaluate potential upgrades—all of which may be “far beyond their area of expertise,” Pollitt says. For example, an administrator might be drawn to expensive air filters, even when DIY boxes could work better while being far less costly.
Schools may also face bureaucratic challenges in accessing funding or working through regulations. In Philadelphia, for instance, federal funds for better ventilation are controlled by a “highly conservative state legislature,” says David Backer, an expert on school finance at West Chester University. “Around a billion dollars is sitting in a pot; they just don’t want to spend it.”
Some administrators might even hesitate to use portable air filters purchased or built by local parents because they haven’t been officially approved by a district’s finance office first. And when portable filters are available, teachers must be taught to use them correctly. An air filter turned on a low setting in the corner of a classroom, for example, might not work well.
What parents can do
Parents interested in improving their school’s ventilation can learn more from publicly available resources, such as this flow diagram from Pollitt and colleagues at Yale and Srikrishna’s instructions for DIY air filters. They can also join a growing community of parents, teachers, and ventilation experts on Twitter. Experts are often willing to share information and answer questions.
Campaigns for better air quality in schools can take months. Sometimes, in response to inaction from administrators, school communities will take matters into their own hands by building DIY air filters. In Philadelphia, the high school students’ project and other school air monitoring efforts have sparked a series of events to build these filters and a social media push to publicize the project, led by the local Democratic Socialists of America chapter.
“Don’t let anyone deter you from voicing your findings,” says Craig, who would like her project to serve as inspiration for parents, teachers, and other students to advocate for better air quality in schools. “Keep using your voice to create a safe environment for students to learn.”