involved in the response to the 2001 anthrax attack. and you remember this just after 9/11. a very scary moment for the country. one, he said you know, it's important to have this because we have to have it around so we can develop defenses in the future. the other thing he said is that the risk to the general population from something like this is not great, that this in his view is confined to those workers, still a serious neb you 75 people, deadly disease, but the folks back home shouldn't be concerned that they're at risk from this. >> sanjay, it was several days, as you said, that this was sitting in the sort of lower security area. if these scientists were exposed to anthrax between the dates of june 6th and june 1th, how long until we're going to know if they've been sickened? >> some people if they're going to get sick can get sick very quickly. usually two months is the outer border of that. you don't quite wave the all clear flag at that point. that's typically how long the