I don't doubt you're right but I also worry that concern over each vector for bad air could easily make us neurotic. Many problems of this sort (e.g. wood natu

I don't doubt you're right but I also worry that concern over each vector for bad air could easily make us neurotic. Many problems of this sort (e.g. wood naturally contains formaldehyde) are likely solved using plant life. So; the solution could be cheap and affordable. I realize this seems like homespun vaguely natural medicine (no chemicals!) advocacy but this is not that. There's a nice NASA study on the subject in my comment below.