Dr. Anthony Maresso, assistant professor of molecular virology and microbiology at Baylor College of Medicine in Houston, answers questions on ricin:

Q: 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.

Q: 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.

Q: 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.

Q: 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.

Q: 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.

Q: 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.

Q: 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.

Q: Can it spread from person to person?
If you are exposed to ricin and it’s in your clothing or hair, it’s very low probability (not likely) that it can be transferred from one person to another. If you are experiencing symptoms of exposure to ricin, you cannot transmit to another person.

Q: How do you detect ricin?
There are measures in place that the government uses to screen for this, but those are not available to the general public. However, it’s important to avoid all suspicious powder-like material, regardless of its color or texture.

Q: What should you do if you think you are exposed to ricin?
If you know you’re exposed via aerosol, immediately leave the area and get fresh air as soon as possible. If you believe it’s on your clothing the general recommendation is to remove the clothing, preferably by cutting the clothing off rather than pulling it over your head. Take a shower and thoroughly rub your body with soap for 10 to 15 minutes and wash your hair as well. Immediately contact emergency personnel. Don’t manipulate, handle or touch any suspicious packages or letters that you do not recognize.

Q: If it’s detected in an area, or there is a suspicion of ricin, who needs to evacuate?
Do not manipulate, handle, or touch any suspicious packages, letters, or material suspected of containing ricin or powder-like material. Contact emergency personnel immediately. If exposure is in a single room, other parts of the building may be contaminated, and the entire room or building should be evacuated.

Q: Any additional information you would like to add?
The Center for Disease Control and Prevention is a good resource to learn more about ricin. Relative to some other toxins, the amount of ricin needed for death is much higher and exposures of this sort are usually with a crude preparation, which in and of itself is not usually very potent. However, all the normal procedures for handling or staying away from suspicious packages and letters should be applied.