Looking over the Atryn references I saw no mention of the University of Texas work on acute inhalation injury. It has been a while but the pr suggested there might be more to follow: http://www.gtc-bio.com/pressreleases/pr040203.html
The patent application for Atryn aerosol for acute lung injury speaks of administration immediately and then say every two hours. It also refers to a "kit" which fits in with my hope that substantial amounts of product might be required if such kits were issued in large numbers (to firefighters or soldiers), since one would expect expiration dates to be set conservatively given the severe conditions of field deployment.
If air pollution keeps getting worse (multinationals are already fleeing Hong Kong because of it) such kits might find some use by civilians as well.