While not really common, it is not odd to see a person on the street with a surgical mask over their mouth (seldom over their nose as well). I have tried to find out the reasons although I confess I haven’t talked directly to someone wearing the mask since I didn’t want to offend a stranger.
I’m told that the reasons for wearing the mask may vary from having a cold to avoiding the dirty air. Neither of these explain why the nose isn’t covered…they can’t all be mouth breathers. And the effectiveness of these inexpensive masks, especially as worn as they are, is probably limited, especially for air pollutants.
On a different but related subject, I see a few vendors, restaurant wait staff, or servers wearing a clear plastic guard that loops over their ears. The purpose is to avoid the person breathing on or coughing on the food. The device is fairly unobtrusive and probably has some efficacy although I would think making it a little bigger would make it much more effective.
In any case, I appreciated the business’s efforts at keeping my food safer.
This last picture (sorry I don’t have a better image) shows the cook in a local chain restaurant with a face mask, below his mouth. Maybe he is covering a goatee?