I posted it once before. It was from May 8, it says updated May 20 but I don't see much difference in the content.

Anyway, it agrees that you don't stand much chance of getting it from a brief close walk-by of someone. But in indoor areas where there isn't great air circulation, there are droplets that stay in the air for a certain period of time. And someone who has to STAY in that area all day is at risk.

So you don't wear a mask in the grocery store to protect yourself. You don't even wear a mask in the grocery store to protect someone who might walk within a few feet of you for a brief second. The reason to wear a mask is because in a grocery store full of unmasked people, hundreds coming in and out all day, the employees who are forced to spend 6 or 8 hours in that area WILL have contact with enough droplets to potentially become infected. That's why you wear the mask.

I heard over 100 grocery store employees in the US have died from CV. Don't know enough numbers to know how that compares to the number of grocery workers or other professions.

My feeling after reading that article is that all the handwringing over crowded beaches and outdoor parks is way overdone. Outdoor air circulation means even if you are sitting a few feet away from someone on the beach, unless they sneeze in your direction, the droplets they exhale normally will be carried off and will not linger. I think outdoor stuff is a lot safer than some of the alarmists would make you believe.

But I believe indoor spaces with a lot of people -- shopping, restaurants, crowded workplaces -- are still a significant issue. The equation she talks about in terms of DURATION of exposure multiplied by the amount of droplets you might be getting affects people who work indoors in one place with lots of people for a long period of time (such as grocery workers). And masking the entire populace absolutely helps those people, such as store employees or co-workers.