: The ricin that showed up in a letter to the office of Senate majority leader Bill Frist brought back memories of the anthrax attacks in 2001, highlighting the concerns about bioterrorism. This particular poison has been used in assassinations, most notably that of  Bulgarian dissident Gregory Markov in London in 1978. Otherwise, ricin has been more talked about than used as a biological weapon.

Ricin is not a disease it is a bio-toxin that comes from the process of making castor oil from castor beans. It is not an efficient killer, either. Markov lived for four days before succumbing to the poison that had been delivered through a sharpened umbrella. The Bulgarian secret police is thought to have been responsible for the murder of Markov, who had taken part in BBC broadcasts after defecting from Bulgaria. The KGB apparently provided technical assistance for the successful attempt after two previous attempts had failed.

Ricin can be inhaled or ingested. Symptoms of poisoning occur 4-8 hours from entering the human body and include fever, vomiting, stomach pain, and a high white blood cell count. If inhaled, it can cause coughing, followed by respiratory distress and death. Skin and eye exposure are other avenues for ricin poisoning.

The lethal dosage is very small one microgram per kilogram of body weight. However, unlike anthrax or any biological warfare agent, ricin poisoning is not contagious, nor can it be spread. It is a bio-toxin that acts in a manner closer to a persistent chemical agent due to its stability. No antidote for ricin poisoning exists. Treatment usually consists of getting the ricin off the body and out of the system and providing supportive care to relieve the symptoms.

The source of the ricin in the letter sent to Senator Frists office is unknown. However, this is the third ricin letter sent. The first was to an airport in South Carolina, the second to the White House in November. Both attacks have been linked together. The Senator is considered to be a target of this letter.

Terrorism cannot be ruled out in January of 2003, a suspected al-Qaeda cell in the United Kingdom was broken up. They were suspected of producing ricin. Also, in June of 2003, 300 bags of castor beans were found in Iraq. The bags had been labeled as fertilizer. Other terrorist cells were broken up the terrorists had apparently been planning to use poisons. Harold C. Hutchison

CDC Fact Sheet:
http://www.bt.cdc.gov/agent/ricin/facts.asp

CDC Question and Answer Sheet:
http://www.bt.cdc.gov/agent/ricin/qa.asp