Thread by @DKThomp

I wrote about the science of COVID's indoor vs. outdoor transmission, and what it means for the future of the great indoors, including:

- offices
- restaurants and retail
- theaters
- arenas
- bars and clubs
- gyms and fitness centers

theatlantic.com/ideas/archive/…

Before we get into the findings, your COVID caveat emptor:

There is so much we don’t know about how this disease spreads and what conditions facilitate its transmission. The studies in this article aren't outliers. But the science here is far from settled.

Okay, let's go...

The indoors are riskier—full stop.

A Hong Kong survey reviewing 7,324 cases in China found “1 outdoor outbreak."

medrxiv.org/content/10.110…

A Japanese study estimated odds of indoor transmission to be “18.7X greater" than open-air environments

medrxiv.org/content/10.110…

The case studies bear this out.

Here is the famous Guangzhou restaurant study:
wwwnc.cdc.gov/eid/article/26…

Finding: 9 ppl sitting in AC airflow path get sick from droplet transmission

What it means: Increase table distancing, increase ventilation, maybe move diners outside

A Korean call center investigation holds similar lessons
cdc.gov/mmwr/volumes/6…

Finding: call center outbreak in tall building with shared elevators is OVERWHELMINGLY concentrated in an 11th floor phone bank

What it means: Shared air is riskier than shared surfaces

Backing up: These single-event studies aren't gospel. But their lessons are illustrative.

Just yesterday, CDC announced the virus "does not spread easily" from touching surfaces or objects, but mainly spreads from person-to-person, through respiratory droplets.

Last case-study: The WA choir outbreak
cdc.gov/mmwr/volumes/6…

Finding: Long choir practice w/ 61 ppl leads to 53 probable cases—attack rate of 87%(!)

Implication: It’s not just the space—it’s the spit. Risk is augmented by “super-emitters,” including loud talkers and singers

So what do these studies tell us about how public indoor spaces will change before a vaccine is available?

Here are two alternate futures for offices, restaurants, and theaters.

theatlantic.com/ideas/archive/…

Alternate futures for the office:

- Door 1: Socially distanced work stations, bans on big long meetings, and masked encounters make offices even more awkward than they already are, accelerating remote work

- Door 2: Offices with temp checks and tests become trusted third spaces

Alternate futures for restaurants:

- Door 1: Dine-in service moves outside and ppl love the al fresco dining experience, which also cuts down on car culture

- Door 2: Weather exists, so outdoor dining isn’t a complete solution. Indoor dining is a chore not worth the risk.

Alternate futures for theaters:

- Door 1: Social distanced seating, staggered admissions, at at-seat concessions (less crowding) preserves some shows, but ticket $$ rise and production $$ falls.

- Door 2: Singing is deemed an intolerable risk. Musicals are canceled.

My best attempt to synthesize these studies and my conversations with scientists, healthy building experts, and business people is:

This is going to be a marathon. Be S.A.F.E.

theatlantic.com/ideas/archive/…