Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Ricin is a potent toxin that has gained attention in recent years because it could be used as an agent of
biological warfare or as a
weapon of mass destruction (WMD). Derived from the beans of the castor plant (Ricinus communis),
ricin is native to Africa and common in warm climates worldwide. More than 1 million tons of castor beans are processed every year worldwide;
ricin is part of the waste material that remains after castor beans are
processed. It is easily and inexpensively produced, highly toxic, and is stable in aerosolized form. Ricin has no treatment or vaccine.
Ricin poisoning is not spread from person to person.
Although a large amount of ricin would be necessary to produce many casualties, it would be highly effective within a closed environment. Ricin can be disseminated as an aerosol, by injection, or as a food and water contaminant. Its use as a food and water contaminant is a major concern. If ricin were used in that fashion, resultant deaths could overwhelm local health care resources.
Even use without casualties can be disruptive. Three US Senate office buildings closed on February 3, 2004, after ricin was found in the mailroom that serves Senate Majority Leader Bill Frist's office. No injuries were reported.
On February 4, 2004, as part of the ongoing investigation as to the source of this most recent ricin attack, the Secret Service acknowledged that ricin had also been found at a White House mail-processing center in early November 2003.
A vial containing ricin was also found at a post office in Greenville, South Carolina, in October 2003. The envelope, addressed to the US Department of Transportation, was labeled
"caution RICIN POISON." The letter, protesting a proposed federal limit on the number of truckers' hours behind the wheel to go into effect in January 2004, was signed
From 1991-1997, three cases involving ricin were reported in the United States.
In Minnesota, four members of the Patriots Council, an extremist group that held antigovernment and antitax ideals and advocated the overthrow of the US government, were arrested in 1991 for plotting to kill a US marshal with ricin. The ricin was produced in a home laboratory. They planned to mix the ricin with the solvent dimethyl sulfoxide (DMSO), and then smear it on the door handles of the marshal's vehicle. The plan was discovered, and the men were convicted.
In 1995, a man entered Canada from Alaska on his way to North Carolina. Canadian custom officials stopped the man and found him in possession of several guns, $98,000, and a container of white powder, which was identified as ricin.
In 1997, a man shot his stepson in the face. Investigators discovered a makeshift laboratory in his basement and found agents such as ricin and nicotine sulfate.
The use of ricin is not limited to the United States.
In December 2002, six terrorist suspects were arrested in Manchester, England. Their apartment was serving as a "ricin laboratory." Among them was a 27-year-old chemist who was producing the toxin.
On January 5, 2003, British police raided two residences around London and found traces of ricin, which led to an investigation of a possible Chechen separatist plan to attack the Russian embassy with the toxin. Several arrests were made.
The major symptoms of ricin poisoning depend on the route of exposure and the dose received, though many organs may be affected in severe cases.
Initial symptoms of ricin poisoning by inhalation may occur within 8 hours of exposure. Following ingestion of ricin, initial symptoms typically occur in less than 6 hours.
Inhalation: Within a few hours of inhaling significant amounts of ricin, the likely symptoms would be respiratory distress (difficulty breathing), fever, cough, nausea, and tightness in the chest. Heavy sweating may follow as well as fluid building up in the lungs (pulmonary edema). This would make breathing even more difficult, and the skin might turn blue. Excess fluid in the lungs would be diagnosed by x-ray or by listening to the chest with a stethoscope. Finally, low blood pressure and respiratory failure may occur, leading to death. In cases of known exposure to ricin, people having respiratory symptoms that started within 12 hours of inhaling ricin should seek medical care.
Ingestion: If someone swallows a significant amount of ricin, he or she would develop vomiting and diarrhea that may become bloody. Severe dehydration may be the result, followed by low blood pressure. Other signs or symptoms may include hallucinations, seizures, and blood in the urine. Within several days, the person's liver, spleen, and kidneys might stop working, and the person could die.
Skin and eye exposure: Ricin is unlikely to be absorbed through normal skin. Contact with ricin powders or products may cause redness and pain of the skin and the eyes.
Death from ricin poisoning could take place within 36 to 72 hours of exposure, depending on the route of exposure (inhalation, ingestion, or injection) and the dose received.