On July 6, 2020, 239 scientists sent an open letter to the World Health Organization (WHO) calling the agency to revise its statements on the transmission of COVID-19. The virus, they said, is not merely transmitted through large exhaled droplets that immediately fall to the floor—as the agency had thought—but also through much smaller droplets that permeate the air. That means when people walk into a room previously occupied by an infected person, whether they are six, 12, or 18 feet apart from each other frankly matters very little. Social distancing will not keep us safe when the virus spreads via particles 10,000 times smaller than a human hair that can be suspended in the air for hours and travel up to 30 feet.
It’s normal for public policy to lag behind the best available science. Remember how long it took us to implement adequate safety regulations to rid school buildings of asbestos? New scientific insights on important problems for our health and well-being are first shared in academic papers. They are then picked up by popular science journalists, whose reports find their way into the mainstream media and trade magazines like this one. Then they stir public opinion and, finally, push policymakers to take action.
This time around, we simply don’t have the time to wait for the normal process to unfold. Since August 5, more than 110 active K-12 teachers, administrators, and staff have died from Covid-19. When will enough be enough?
The importance of indoor quality has been known for decades, yet so little has been invested. Such invisible problems are often ignored and it’s to our detriment. Worse, this is a country of aging school buildings. In 1999, the year of the most recent measurement, the average age of the main instructional building of public schools was 40 years (source: NCES). Anyone who has in the last decades visited a school will know that not much has changed since. Our schools were built to be as energy-efficient as possible, which is a good thing in and of itself, but the result is that they were designed to keep INSIDE as much as possible! Therein lies the dilemma: recirculating inadequately filtered or ventilated air makes indoor air more dangerous. This pandemic has proved to us just how dangerous it can be.
It’s true that facilities and building administrators can, and often do, upgrade existing HVAC configurations and settings, but this is only part of the solution. As with any complex problem, the answer is complex—with some decisions requiring tradeoffs. Can my HVAC system run continuously while a building is occupied? Can it handle the “beefed-up” filtration required to improve air cleaning? Is it enough protection? Will I be able to convince my staff and customers that it’s now safe to enter? The answer to these questions is a resounding “maybe?”
Upgrading HVAC systems can be daunting, slow, and expensive. Thankfully, there is a better way. We can look to tried-and-true technology. Professional (not consumer grade) portable, medical HEPA and UVC units are powerful tools to address inadequate ventilation and indoor air safety (see for example this CDC recommendation on indoor air ventilation). They’re also remarkably practical and affordable. With decades of track record and improvement, they certainly don’t need fancy marketing buzzwords or pandemic fear-mongering. They just work.
A professional air cleaning system, whether it’s portable or built-in, will change the air at least six times an hour. In extremely crowded environments, such as cafeterias, more systems may be needed to achieve appropriate air changes per hour. Modular, portable solutions can help make this easier.
Air purification systems form part of engineering controls that are not only very efficient in keeping the air clean but are also dependable. They do not get distracted, or sloppy. They do not ignore guidelines. Machines are simply switched on and run continuously. They flank but don’t replace, all the other common risk-mitigation factors in place today.
Well ventilated school buildings will keep teachers and students from getting sick while they are inside. If schools want their students and staff back anytime soon, they will have not only to create safe conditions but also to have solutions in place that are visible. Obvious measures that improve indoor air quality will reassure anyone who enters a building that they are secure. Portable air purifiers are such a measure that says, “We’re doing everything we can to keep you safe.”
We need to keep our students and staff healthy, our school buildings healthy, and our communities healthy. Portable, professional-grade air cleaning systems are a powerful tool to help us achieve this. Although this pandemic is our most urgent crisis, if there’s a silver lining, it’s that we’ve gotten a lot smarter about why indoor air safety matters. Cleaning air is the next, common-sense hygiene habit—like hand washing—that we urgently need to adopt.