No, we don't have data that masks are protective in a salon situation where people are in close contact for a long time. I wouldn't trust the masks that most people are using (surgical masks with half-inch gaps on either side and quarter-inch gaps around the nose, or single-layer cloth masks) to protect me in that scenario.
Agreed. An important thing to remember about the salon story mentioned above is that it is not 45 independent exposure experiments. Some people never shed much virus, or the stylist might not have been shedding very much on that particular day. If you tracked 45 different infected stylists, each working with one client, you might get very different results. This one story definitely does not prove you are safe at a salon as long as you are wearing a mask! (Although please do wear one if you must go).
