sorry, but I've read that dust masks are for dust, and you should ALWAYS use a respirator when airbrushing-unless you do it ouside-no matter if you're using solvent-based paints, or water based. And if you're using solvent-based, also wear gloves.
And, no matter which kind of paint you use, always have adequete ventilation or do your painting in a vented spray booth-again, unless you're painting outside.
Read the article by Andy Sperandeo about painting safety that was in Model Railroader in 1987.
Also, ther was an article in ther sometime in the late 80s or early 90s about a proffesoinal model painter who did beatiful work, but, sadly, he never took any precautions. Late in life, he started to lose coordination, and he caught cancer. By the time anyone founut, it was too late, it had spread too far, and they couldn't do anything about it. But, all the doctors agreed paint fumes were the cause.
I buried my father because of paint fumes, so you can BET I use protection!!!