COVID-19: We Need to Talk About Ventilation

I recently took a drive-through COVID-19 test at the University of North Carolina. Everything was well organized and efficient: I was swabbed for 15 uncomfortable seconds and sent home with two pages of instructions on what to do if I were to test positive, and what precautions people living with or tending to COVID-19 patients should take.

The instructions included many detailed sections devoted to preventing transmission via surfaces, and also went into great detail about laundry, disinfectants, and the exact proportions of bleach solutions I should use to wipe surfaces, and how.

My otherwise detailed instructions, however, included only a single sentence on “good ventilation”—a sentence with the potential to do some people more harm than good. I was advised to have “good air flow, such as from an air conditioner or an opened window, weather permitting.”

. A major U.S. airline informed me how it was diligently sanitizing surfaces inside its planes and in terminals many times a day, without mentioning anything about the effectiveness of air circulation and filtering inside airplane cabins (pretty good, actually).

A local business that operates in a somewhat cramped indoor space sent me an email about how it was “keeping clean and staying healthy,” illustrated by 10 bottles of hand sanitizer without a word on ventilation—whether it was opening windows, employing upgraded filters in its HVAC systems, or using portable HEPA filters. It seems baffling that despite mounting evidence of its importance, we are stuck practicing hygiene theater—constantly deep cleaning everything—while not noticing the air we breathe.

According to a new study coming out in ScienceDirect’s September issue, some measures, among others, that need to be taken to mitigate airborne transmission include:

Provide sufficient and adequate ventilation (supply clean outdoor air, minimize recirculating air), particularly in public buildings, workplace environments, schools, hospitals, and aged care homes.
Supplement general ventilation with airborne infection controls such as local exhaust, high-efficiency air filtration, and germicidal ultraviolet lights.
Avoid overcrowding, particularly in public transport and public buildings.