Why a Hot Dog Cart is Not Like a Grammar School: The Risks of COVID-19 Reintegration Explained in 4 Minutes.
There are many reasons that a hot dog cart is not like a grammar school.
One is small and made of metal. It is used to distribute steaming links of mystery meat to people too busy to ask questions.
The other is larger and packs kids and teachers into an enclosed space for 7 hours at a time.
As we prepare to reintegrate into our communities following a 2 month quarantine due to COVID-19 it is important to recognize when one thing is not like another.
Places are different from one another.
People are different as well.
Which people should reintegrate into which places is the most important question that we need to ask in this moment.
Here’s a quick guide.
In order to be infected by a virus you need to be exposed to an infectious dose.
An infectious dose is the amount of a virus needed to establish an infection.
No one knows the exact number of virus particles necessary to contract COVID-19, but experts estimate that as few as 1,000 virus particles may constitute an infectious dose.
Breathing recycled air for a long period of time in an enclosed space equals a prolonged, low dose, exposure to virus particles should they be present.
The danger is in the duration of the exposure.
(As a point of reference, a single breath results in 50 — 500 respiratory droplets being released in the atmosphere. A sneeze, on the other hand, releases up to 30,000 respiratory droplets at up to 200 miles an hour resulting in 200,000,000 virus particles quickly circulating throughout a room.)
A shorter duration of exposure is needed to become infected when the number of virus particles in the environment is increased.
90% of all transmissions of COVID-19 take place in indoor environments where a.) prolonged, low dose exposure b.) brief, high dose exposure or c.) prolonged, high dose exposure took place.
The environmental factors that determine infection risk are volume of airspace, the duration of time spent in the environment, and the number of virus particles present in the environment.
A hot dog cart is outside. The volume of the air space is huge. It takes two minutes to order a hot dog. The duration of the interaction between hot dog man and man who wants hot dog is short.
This is a very low risk environment.
A grammar school is enclosed. Even a large classroom is home to a relatively small volume of airspace. If an asymptomatic, but infected, teacher sneezes unexpectedly and releases millions of virus particles into the air the risk of student infection is present.
If the teacher simply breathes, and frequently speaks, for the duration of an entire school day while releasing infectious virus particles the risk is present as well.
If two students in the front row contract the virus and transport it to another enclosed space (home) and sneeze, cough, or breathe for an extended period of time the risk of passing it on to Mom or Dad is high.
If an asymptomatic-but now infected-Mom or Dad go to an enclosed office space and breathe in that space for 8 hours (or sneeze in it once or twice) the risk of infecting their co-workers is high.
This risk would be reduced if they ran a hot dog cart.
Every environment is more like a hotdog cart or more like grammar school.
Every environment within an environment is more like a hotdog cart, or, more like a grammar school.
Public bathroom=Grammar school.
Balcony=Hotdog cart.
Vehicle with the windows up=Grammar school.
Convertible with the top down=Hotdog cart.
Use this scale when deciding which environment to expose yourself to. Use your own health as a gauge as well. Comorbitities and pre-existing conditions make the risk of entering a high risk environment much riskier.
Here’s to practicing respiratory hygiene, thinking critically about the environmental factors that we expose ourselves to, and working towards the day when we can both reopen the grammar schools and safely operate the hot dog carts of the world.
(The information in this article is based on research material masterfully presented in the following article by Erin Bromage. Erin is a Comparative Immunologist and Professor of Biology (Specializing in Immunology) at the University of Massachusetts, Dartmouth. My hope in this writing was to draw additional eyes to Bromage’s work.)
About the author:
David Bidler is president of Physiology First, a nonprofit organization that shares solutions to stress and anxiety management with students across the globe.
In 2017 David co-founded Breathe to Perform to share the power of better breathing with individuals, families, workplaces, and teams.
David is the author of the upcoming book Breathe To Perform: 3 Simple Breathing Exercises to Reduce Stress, Improve Energy, and Peak Athletic Performance to be released on May 17th, 2020.
