August 2020
The hardest pandemic question facing us today is how to keep our kids safe in school. Some people feel that until there is a vaccine, there is no way schools can be made safe. Others feel that with careful planning, social distancing, masks, track and trace, etc, schools can be safe today.
Both of these groups tend to ignore what may be the most important thing we can do to keep our classrooms free of the virus, and our kids free of disease: Proper ventilation and filtering.
While there is some disagreement over which particles coming out of the mouths of infected people are the primary carriers, this is clearly an airborne disease, and cleaning the air could go a long way towards stopping its spread.
I do see occasional discussion of modernizing air conditioning systems by our school committees and teachers, but the most important step -high quality filtering- is almost never mentioned. I don’t understand it.
In an article in the July 30th Atlantic Magazine, Zeynap Tifekci, Associate Professor at the University of North Carolina, examines this issue, interviewing experts from many universities around the world. She points out that “Classrooms are places of a lot of talking; children are not going to be perfect at social distancing; and the more people in a room, the more opportunities for aerosols to accumulate if the ventilation is poor. Most of these ventilation issues are addressable, sometimes by free or inexpensive methods….”
There are two key mitigation strategies for countering poor ventilation and virus-laden aerosols indoors, and neither is prohibitively expensive. One is frequent exchange of air with outside air. This can be done by simply resetting the air conditioning system, which is usually set to bring in a minimum amount of air to maximize efficiency.
The other is filtering. Air conditioning systems already have filters. They simply need to be upgraded to “MERV 13” or higher. Plus, every room should have a portable HEPA filter, which can trap small viruses. These filters cost as little as a few hundred dollars.
Some countries have paid much more attention to ventilation and the results are impressive. Japan developed guidelines that included the importance of ventilation in many different settings, such as bars, restaurants, and gyms.
“Six months later, despite having some of the earliest outbreaks, ultradense cities, and one of the oldest populations in the world, Japan has had about 1,000 COVID-19 deaths total—which is how many the United States often has in a single day” according to Professor Tifekci.
Hong Kong, a similarly dense, subway city, using similar guidelines, has had only 24 deaths.
Jose-Luiz Jimenez, an air-quality professor at the University of Colorado, “…wondered … why the U.S. hadn’t set up the mass production of HEPA filters for every classroom and essential indoor space.” Instead, says Tifeczi, one air-quality expert “…reported that teachers who wanted to buy portable HEPA filters were being told that they weren’t allowed to, because the CDC wasn’t recommending them.”
Professor Tifeczi checked. There is no shortage of portable HEPA filters. There is no run on them.
This failure to implement a reasonable, affordable approach to preventing the spread of a pandemic virus among our kids is a tragic mistake in my opinion.
