Originally posted by SurfaceTension
From the WTOP link (perhaps updated since your post)
Is this like finding rat poison, moth balls, or any other harmful substance, or does a single microscopic airborn particle pose a threat?
from what I gather, yes it posses a threat but it depends on the way it is dispersed through the air. If its dispersed via aresol spray then yes dangerous (something about molecular structural changes when dispersed this way). Just being on an envelope, not as bad as long as it is not injested. Then again, the anthrax thing last year was handled the same way where everyone was purely speculating and downplaying the severity. Who knows how dangerous it is -- its up for everyone for themselves to draw their own conclusions.
I for one, don't really think its a big deal, I would just feel better if I could trust the govn't to act responsibly this time - unlike the anthrax fiasco last year.