What makes me chuckle is that people think that the theater is a healthy environment to begin with!
If one stops to consider the dust that constantly permeates a performance space contains the remnants of every speck of wood dust, metal dust, foam, paint, and carpet scrap. Not to mention the fumes from acetone, paint thinner, spray paint, hair spray, ammonia and other nasty chemicals. Plus a consistently darkened space allows mold spores to thrive. Just try slapping a seat in the front row of your theatre and see what flies out of it!
If people are THAT sensitive, perhaps they need to travel everywhere in a plastic bubble. Most people ingest more carcinogens during the drive to the theatre, than from the limited exposure of sitting 20 feet away in a ventilated room, frequently with 20+ foot ceilings.