I seen a young person in their 20's wearing one of those in a store a couple of weeks ago; I took me by such surprise I laughed out loud. Everybody wearing one of those would look like a terrorist or swat team member.
I did read somewhere that masks like this would not stop the pathogen from going thru the filter; but would only stop moister droplets from going thru to other people.
I had to help take asbestos out of a building years ago; when it was a hazmat directive from the federal govt; and had to wear on of those masks for hrs; cleaning old asbestos insulation out of a boiler room; that was horrible.
They get sweaty and you feel like you can't get proper air; especially if you are doing a strenuous job. We would go outside every half hour or so; so we could breath good air. It's not something you want to wear all day long.