You're the second person this week who's suggested a mask, oddly enough.

They drive me batty, and I'm not sure they'd do enough good: my asthma tends towards long stints of my lungs going "Arrrrrgh!" and slowly shutting down rather than sudden acute problems, and during pollen season, there's pollen all over the place. Unless I want to wear a mask all the time, etc. etc., not as helpful as it sounds.

(I do run an air filter all the time at home, which helps a lot. And it's part of the reason a Y membership is appealing, because water is not so much with the allergen issues for me as long as they're not miserably overchlorinating.)