Avoiding Risks During ReopeningFascinating study of how the Coronavirus has spread (factually) and how to avoid the risks of being in the same situation. Remembering that many, many people are asymptomatic (and in these particular cases were not showing any signs of the disease), it's good to know what situations to avoid, and which are less risky.
For example, being in an enclosed indoor space (even with social distancing) is much riskier than being together outside.
The article lists some risky situations based on where the disease actually spread. Especially interesting to me was the tragic choir rehearsal in Washington, where precautions were taken to keep people safe, yet 45 of 60 people in the choir got sick and two died....
Choir: The community choir in Washington State. Even though people were aware of the virus and took steps to minimize transfer; e.g. they avoided the usual handshakes and hugs hello, people also brought their own music to avoid sharing, and socially distanced themselves during practice. They even went to the lengths to tell choir members prior to practice that anyone experiencing symptoms should stay home. A single asymptomatic carrier infected most of the people in attendance. The choir sang for 2 1/2 hours, inside an enclosed rehearsal hall which was roughly the size of a volleyball court.
Singing, to a greater degree than talking, aerosolizes respiratory droplets extraordinarily well. Deep-breathing while singing facilitated those respiratory droplets getting deep into the lungs. Two and half hours of exposure ensured that people were exposed to enough virus over a long enough period of time for infection to take place. Over a period of 4 days, 45 of the 60 choir members developed symptoms, 2 died. The youngest infected was 31, but they averaged 67 years old. (corrected link)
Good reason for churches NOT to have choir practice. The infected person was asymptomatic and precautions were taken and yet.....
The restaurant example from China is particularly revealing because some people near the (asymptomatic) infected person did not get sick because of the air flow, but many others did.... (diagram in article)
Restaurants: Some really great shoe-leather epidemiology demonstrated clearly the effect of a single asymptomatic carrier in a restaurant environment (see below). The infected person (A1) sat at a table and had dinner with 9 friends. Dinner took about 1 to 1.5 hours. During this meal, the asymptomatic carrier released low-levels of virus into the air from their breathing. Airflow (from the restaurant's various airflow vents) was from right to left. Approximately 50% of the people at the infected person's table became sick over the next 7 days. 75% of the people on the adjacent downwind table became infected. And even 2 of the 7 people on the upwind table were infected (believed to happen by turbulent airflow). No one at tables E or F became infected, they were out of the main airflow from the air conditioner on the right to the exhaust fan on the left of the room. (Ref)
It's critical that we continue to open up the economy, but it's also important that we understand how to keep as safe as possible.
For those interested, it's a good read.
