Recently, ricin was discovered in a senate office and this country became concerned with potential exposure.
Fear occurred as information about ricin was distributed. Much of the information was erroneous. Facts about ingestion of ricin and inhalation of ricin were confused.
Ricin comes from castor beans. Most of our experience with ricin comes from accidental ingestions of castor beans by toddlers. One or two beans can be extremely toxic, however, the bean has to be masticated to release the ricin. If the bean is swallowed whole, there should be no toxicity.
The real concern was inhalation of ricin. Ricin can be inhaled; however, it is extremely difficult to make the ricin particles of the size and purity to aerosolize them. A large quantity of ricin would be necessary to aerosolize ricin particles and expose many people. (The quantity needed would be much larger than the quantity of anthrax as anthrax is much more easily dispersed in air.)
Symptoms from inhalation of ricin should occur very shortly after exposure, certainly within a few hours. Symptoms include shortness of breath, coughing, wheezing, and chest pain. Pulmonary edema can develop. The fact that none of the people in the senate building were ill within a few hours was good evidence that there hadn’t been a significant clinical exposure.
Much of the concern resulted from the information that a very small amount of ricin is required to cause poisoning and death. This is true when ricin is ingested or injected. It is also true that a small amount of ricin could cause toxicity by inhalation. (All data on inhalation comes from animal exposure). However, the difficulty in aerosolizing ricin was not discussed. This difficulty is the main reason that ricin is not a good weapon of mass destruction.
Causing fear in a large number of people is also a terrorist act. Whether ricin was placed in the building by a single person or a group of people, the finding of this agent certainly caused fear and concern.
Remember, the Poison Center is available to answer questions following any potential exposures.
Next Week, Part 3 of “What are the Date Rape Drugs?”
As always, if there any questions, call the MTPC.
I am interested in any questions that you would like answered in "Question of the Week". Please e-mail me with any suggestions.
Donna Seger, M.D.
Medical Director, Middle Tennessee Poison Center