True, You could take the time to whip out the bandana and tie it around your nose as a temporary mask ...or

you could reach down, grab the top of your shirt collar and pull it up over your nose. Volia, you now have a piece of cloth over your mouth and nose serving the same purpose as the bandana would have in a fraction of the time. Breathing through your shirt would be equally effective (or ineffective as it were)

Unless the ladies don't wear shirts where you work. In that case let me know where it is and I will swing by to drop off a resume

Seriously though, to each their own but I have always viewed a bandana as one of those things people always think they need but never really find a practical use for. Almost like it's taboo to not carry one because all the "survival experts" will make fun of you if you don't. I wonder has anyone used one for anything other than wiping sweat off themselves? Personally I think a pair of gloves would be much better to pack in a pocket if you insist on using the space. If you think about it, a bandana should be the easiest piece of gear in the world to improvise from your urban surroundings if you did suddenly need one. Simply find some cloth and cut to size.

Hey, I just noticed you are from Ontario Jack. I just sold my house in Alberta and will be moving there in a few weeks. Maybe I will see you out on the trails.