Understanding Ricin

But its toxicity varies widely depending on how pure it is, doesn't it?
Yes, and it's very important to point out that while we don't know the purity level of the ricin found in the Las Vegas hotel room, typically the ricin that is processed by nonexperts using these anarchist books and Internet guides is less toxic and requires [greater quantities] to actually kill someone. The CDC lists on its Web site that it takes 500 micrograms of ricin, which is about the size of a pinhead, to kill a person. But this is only when the ricin is in its purest form. The threat posed by crude preparation of ricin by the militia groups and other nonexperts is often exaggerated.

So how alarmed should we be by this discovery of ricin in Las Vegas?
Well, we still don't know this person's motives, but there is a history of interest in ricin among extreme right-wing antigovernment groups, Fortunately, however, ricin it is not contagious. It's not like smallpox or plague, which can spread person-to-person. You have to come into immediate contact with it by inhaling or ingesting it or having it injected. It is not a major threat. It is probably on the same level of threat as cyanide or arsenic. It's a poison to kill a few. It could be refined into fine powder and then dispersed and could expose more, but it isn't optimal for that purpose. It's a large protein that tends to be inactivated if spread through the air. Not a major weapon of biological warfare or terrorism threat. It is a concern, however, mainly because of its availability and the ease with which it can be extracted, at least in crude form.

There is currently no antidote for ricin, right?
There is no FDA-approved, licensed antidote. But there are animal models in which immunization has been tested and which I suspect the military already has. Ricin is a poison. But it's not like the anthrax letter attacks in which an entire office building was contaminated. That was a highly refined powder that was volatile and spread through the ventilation system. Ricin does not have those properties.

And ricin is not contagious?
Correct. It is not contagious. You have to come into direct contact with it to be harmed. So people can still go to Las Vegas and they won't run any risk of being harmed.

Even if they stay in that same hotel?
Yes, as long as they stay in a different room.

© 2008