Q&A on ricin: What is it and what are its effects?

Dr. Anthony Maresso
Dr. Anthony Maresso

In light of yesterday’s scare in Washington, DC after letters to President Obama and Sen. Roger Wicker, R-Mississippi, showed positive results for the poison ricin, Dr. Anthony Maresso, assistant professor of molecular virology and microbiology at BCM, explains ricin in this Q&A:

What is ricin?

Ricin is a protein toxin.  It is not an infectious agent, so it is not believed to be able to spread from person to person.

If it enters your body, it can enter into your cells and when it does so, it can prevent proteins that your body wants to make from being made, which is very toxic.

How are you exposed to ricin?

There are a number of ways you can be exposed to ricin.  One way is through inhalation, meaning that you breathe it in.  Eating or ingesting the toxin would be gastrointestinal exposure and then there’s the direct injection into your body.

The concern with what has happened in Washington, D.C. would be inhalation exposure to ricin protein toxin being sent via the mail.

Where is ricin found?

Ricin comes from the castor bean plant. It’s possible to obtain the beans and isolate the toxin and use that for harmful purposes.

However, this is a very crude way to isolate the toxin and I suspect that what’s happened in Washington, D.C. is very crude.

Is this similar to the anthrax scare?

This is very different from the anthrax scare in 2001 where the spores of the bacterium B. anthracis, which causes anthrax and are infectious, were made to be distributed and more easily aerosolized.  It’s much harder to get ricin intoxication through a letter than it is to get an anthrax infection through inhalation of spores, which is a bacterial infection.

That’s not to diminish the concerns for safety and the impact of this event, just that it is more difficult to be intoxicated with crude ricin than it is a specially formulated spore of anthrax.

Is it always toxic?

It’s thought that enough ricin of the size say of a few salt grains is enough to kill an adult human being. Relative to botulinum toxin, it is less toxic but it is much more toxic than many other proteins or protein toxins.

What are the symptoms if you are exposed to ricin?

Inhalation symptoms manifest three to six hours after breathing it in (and you have to breathe in a significant amount), include:

  • Shortness of breath
  • Pain or tightness in the chest
  • Cough
  • Nausea or vomiting (especially if ingested)
  • Fever

If untreated, a person can succumb or die from ricin intoxication in about three to five days.

What is the treatment?

The treatment for ricin exposure is supportive, meaning that the symptoms you are experiencing are treated.  This can include intravenous fluids or pumping of the stomach (if ingested).

There is no known vaccine or antidote that is readily available to the public.

Find out more details about how to detect ricin, what you should do if you think you’re exposed, what to know about evacuation, and more on the BCM site.

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