Friday, May 22, 2020

The mask we need

What do we believe now?

We think that coronavirus is moderately contagious and is spread primarily from person to person rather than by surfaces to person. We think the best way to get COVID-19 is to join an indoor dance and singing session and that outdoor spread is rare. We think indoor masks are valuable and outdoor masks are primarily social gestures. We think cloth masks work primarily by reducing spread from someone with early COVID-19 and minimal symptoms. As of today there's a suggestion that children get mild COVID-19 infections but don't spread them well.

We believe social distancing reduces spread but has a terrible economic cost that falls primarily on non-college workers and small business owners.

We believe effective therapies will emerge gradually over the next 4-18 months and effective vaccines over the next 6-18 months.

So what could we do now that would reduce infection, possibly suppress disease, and allow the economy to reopen?

We should test and trace of course, but given the state of American government and American media (Fox, Murdoch, etc) that's unlikely to be enough.

So what else could we do that doesn't require new technology or new innovation?

We could give every adult a better indoor mask. A mask that gives bidirectional protection, that protects against both infection and transmission. Give it first to 70+, then 60+, then every adult.

What are the features of this mask?

It's reusable of course. Washable with a filter module that's easy to replace. It comes with a UV light sterilizer than can hold several masks. It's a high air flow mask; you can wear it to your indoor CrossFit speakeasy and get your deadlifts done. It's not medical grade, but it's a hell of a lot better than a surgical mask.

If you're going to wear a damned indoor mask, it should work.

This doesn't require new science. It doesn't require new technology. It doesn't require closing the economy. At $100 a unit we could give every American adult this mask and a family UV sterilization unit for 30 billion dollars.

30 billion dollars. That's nothing. Jeff Bezos could do it from his change pocket.

Want to restart the economy?

Make this mask.

Sunday, May 03, 2020

Wearing a cloth mask outdoors is like wearing a helmet in your car

I wrote this first on Twitter:
Outdoor masking is the equivalent of wearing a helmet in your car. Indoor masking is the equivalent of wearing a seatbelt in your car... 
 ... Formula 1 drivers wear helmets in their cars. Makes sense for them. For rest of us net gain is just background risk noise... 
... It took decades of struggle to get Americans to use seatbelts. Even now some don’t. Despite overwhelming value... 
... If you get hung up on wearing helmets in cars people will think you are nuts and ignore the seatbelts.
The best science I've seen on outdoor communication is the Chinese tracing analysis. We aren't going to see much more science -- experts consider the risk too low to be worth researching given all we don't know about indoor transmission (including transit).

There are two valid objections I know of to this stance:
  1. Outdoor masking is of low value but it helps set social expectations that make indoor masking acceptable.
  2. If you don't wear a helmet in your car the risk is on you, if you don't wear a mask outside the risk is on me.
To which I would say - True. But ...
  1. We would never have gotten seatbelts in cars (high value) if we'd insisted that helmets were equally important (much lower value). If we don't have science we have nothing against the forces of stupidity.
  2. Yeah, that does suck. Happily the risk to you is extremely low. As a matter of politeness we should give anyone wearing an outdoor mask a 10 foot space. It's a signal of strong personal concern.
Outdoor masking has a cost beyond damaging expert credibility. It's very uncomfortable to exercise wearing a cloth mask. The physical and mental health benefits of exercise dwarf the non-existent value of the outdoor cloth mask.

Indoor masking is where we should be putting our energy. We should be developing N95 equivalent reusable masks for at risk persons to wear indoors in place of the cloth masks most of us wear.

True story. My father, who was a geek before his time, specced seatbelts on his 1950s company car (to the chagrin of his boss no doubt). They came as 4 point restraints. When he showed up in the car for a date his guest refused to enter the car. Anyone with seatbelts in the car must drive like a maniac.

PS. Regarding those "outdoor plume" studies --- viral reproduction does not scale with respiration. That is, if you breathe 3 times as much you don't exhale 3 times as many viruses.