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June 21, 2022

Despite Access to Federal COVID-19 Funds to Optimize Ventilation, Most Schools Use Lower-Cost Strategies

Author Affiliations
  • 1Contributing Editor, JAMA Health Forum
JAMA Health Forum. 2022;3(6):e222501. doi:10.1001/jamahealthforum.2022.2501

Although substantial federal funding has been available to improve indoor ventilation and filtration in schools to slow the spread of SARS-CoV-2, most US public schools have made no major investments in such strategies since the emergence of the COVID-19 pandemic, according to a study from the Centers for Disease Control and Prevention (CDC).

Instead, most US schools reported that they were more likely to rely on low-cost measures, including moving activities outside and opening doors or windows.

Strategies such as mask use and improved ventilation can reduce the concentration of infectious aerosols that can spread SARS-CoV-2 and can reduce the amount of time people are potentially exposed to the virus, which is linked to lower incidence of COVID-19. Improved ventilation also offers additional potential health-related benefits, the CDC researchers noted, such as preventing spread of influenza and other infections and reducing allergy symptoms.

The US Congress approved billions of dollars in funding in the 2020 Coronavirus Aid, Relief, and Economic Security (CARES) Act and in the 2021 American Rescue Plan (ARP) for US schools for a variety of pandemic-related purposes, such as purchasing high-efficiency particulate air (HEPA) filtration systems for use in classrooms and other areas; replacing or upgrading heating, ventilation, and air conditioning (HVAC) systems; and providing mental health services.

The CDC’s study assessed improvements in ventilation strategies reported by a nationally representative sample of 420 US kindergarten through grade 12 public schools in 50 states and the District of Columbia. The researchers used data gathered between February 14 and March 27, 2022, from the National School COVID-19 Prevention Study, a web-based survey given to school administrators, such as principals or school nurses, or other personnel familiar with COVID-19 strategies at the school.

Among various strategies to improve ventilation, lower-cost measures were most frequently reported, such as moving activities outside (73.6%), inspecting and validating existing HVAC systems (70.5%), and opening doors or windows (67.2%) when it was safe to do so. A much smaller share of schools reported implementing costlier strategies. Only 38.5% of schools reported replacing or upgrading their HVAC systems since the beginning of the pandemic, and fewer than 3 out of 10 said they used HEPA filtration systems in classrooms (28.2%) or eating areas (29.8%).

The researchers examined how school poverty level affected uptake of various ventilation strategies, using the percentage of students eligible for free or reduced-price school lunches as a proxy for school poverty level (defining low-poverty schools as those with no more than 25% students eligible for subsidized meals, mid-poverty schools as those with 26% to 75% of students eligible, and high-poverty schools as those with at least 75% of students eligible). Only 32.4% of mid-poverty schools replaced HVAC systems, whereas 48.8% of high-poverty schools and 45.3% of low-poverty schools reported replacing their HVAC systems.

Mid-poverty schools were also substantially less likely to use portable HEPA systems in classroom areas (20.5%) compared with low-poverty schools (43.8%) and high-poverty schools (36.0%).

In addition, school locale affected uptake of costlier ventilation options. For example, only 15.6% of rural schools used portable HEPA systems in classrooms, compared with 37.7% of city schools and 32.9% of suburban schools. Similarly, only about 29.7% of rural schools replaced or upgraded HVAC systems, compared with 42.8% of both city and suburban schools.

The researchers noted that differences by locale and school poverty level in adopting more expensive ventilation strategies “might be due to supply chain challenges, differences in school or community resources, or accessibility of technical assistance and support for applying to available sources of funding.” They also suggested that mid-poverty schools might have been least likely to implement these more costly strategies to improve ventilation because lower-poverty schools might have been able to implement some of these measures without additional government support and higher poverty schools might have had more experience in accessing and using federal funds.

“Despite availability of substantial federal resources to improve ventilation in schools, findings suggest that additional efforts might be needed to ensure that all schools successfully access and use resources for ventilation improvements, particularly schools least likely to report using resource-intensive ventilation strategies (ie, rural and mid-poverty schools),” the researchers wrote.

According to a report published in May by the Center for Green Schools, many school administrators are not aware of the availability of federal funding to help them improve ventilation. About one-quarter of the school districts surveyed responded that they do not have access to funding to implement additional ventilation and filtration measures, and 24% said that they were unsure. The report also noted that town and rural districts were less likely to report having access to funds for future work compared with urban districts.

The CDC researchers said that public health professionals and funding agencies can help state and local education agencies and school districts by raising awareness about funding sources, noting that supplemental “training and technical assistance can help schools identify and access applicable funding and understand what types of strategies can improve ventilation.”

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Article Information

Published: June 21, 2022. doi:10.1001/jamahealthforum.2022.2501

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2022 Stephenson J. JAMA Health Forum.

Corresponding Author: Joan Stephenson, PhD, Contributing Editor, JAMA Health Forum (Joan.Stephenson@jamanetwork.org).

Conflict of Interest Disclosures: None reported.

1 Comment for this article
Do we have sufficient evidence for these air filtration equipment programs?
Guy Pelouze, MD, MSc | Institut de Recherche Clinique, Pau, France
The issue of air treatment in establishments open to the public is indeed closely linked to the risk of airborne propagation of micro-organisms and other pathogens. This question is not new and still arises in healthcare establishments, whether in the operating theatre or hospital departments and emergency rooms. The pandemic has led to reconsidering this issue of air treatment in addition to personal protection such as masks and social distancing.
1/ It is above all an economic question: the investments and operating costs are high, in particular for equipment with filtration or a virucidal or bactericidal device by UV, for
example. Existing systems are rarely adaptable because the power of the air propulsion engines is insufficient. Operation assumes electrical consumption that has not been modeled for all of these buildings.
2/ The potential advantages are significant because they concern all pathologies linked to an agent transported by the air. These agents are numerous, infectious, allergic, and toxic, and their consequences on human health are fairly well documented. However, it is necessary to differentiate between short-term risks such as in an influenza epidemic or in a particularly important pollen episode, and long-term risks such as particulate pollution. Large health databases make it possible to approach the economic benefit of such facilities.
3/ Solid evidence remains to be established. The number of randomized trials in this area is very limited. Public aid programs do not prejudge this evidence because the equipment is varied in its effectiveness and cost. For example, portable devices for apartments can be efficient and inexpensive but what about schools (1)? Searching for randomized controlled trials with the title: "air filtration efficacy in respiratory infection" finds only 5 articles. This is why it is so important to obtain solid evidence before deciding on such expenditures. Public funds would be better used to improve this evidence, especially in real life, whether it concerns filtration methods in general but also devices in particular.


1. Myers, NTLaumbach, RJBlack, KG, et al. Portable air cleaners and residential exposure to SARS-CoV-2 aerosols: A real-world studyIndoor Air202232:e13029. doi:10.1111/ina.13029