Castor bean plants are a popular garden ornamental, especially in the southern parts of the United States. They are also extremely poisonous. All parts of the plant, but especially the seeds, are very dangerous, posing threats to humans and livestock.
About the Castor Bean Plant
The castor bean plant, or Ricinus Communis, is native to Asia and Africa. It has been spread through its use as a garden ornamental throughout tropical and temperate areas all over the world. It has escaped cultivation, and in the southern United States may be found growing wild on the banks of streams and rivers. The plants can grow to heights of 10 feet or more and have palmate leaves,which are green or purple in color and can reach up to one foot across.The beans, teardrop-shaped brown seeds with dark brown mottling or specks, are highly toxic, containing the phytotoxin ricin. The presence of ricin in the seeds places them among the most toxic in all of nature.
Ricin and RCA
Ricin is one of two poisons contained within castor bean seeds. RCA (ricinus communis agglutinin) is the other. Ricin is the more dangerous because it can pass through the intestinal wall, thereby causing death after ingestion. RCA must be injected into the bloodstream. Ricin is a cytotoxin, or cellular poison. RCA is a poison which causes red blood cells to agglutinate, or form clots.
Effects of Ricin Poisoning
Ricin poisoning may cause several symptoms, depending on how it enters the body. The most common way is through accidental ingestion. Castor beans swallowed without being chewed may pass through the body without serious harm. If the seed coat is damaged, ricin may cause abdominal pain (possibly severe), vomitin, and diarrhea, sometimes with blood. Severe dehydration can occur, leading to a decrease in urine and blood pressure. This can cause other severe problems like kidney damage or failure. Ricin inhaled via an aerosol delivery can also cause severe respiratory symptoms, such as coughing, congestion of the nose and liquid in the lungs. Fever may also result. Victims may have difficulty breathing and experience a feeling of tightness or pressure in the chest. Victims of mild ricin poisoning may recover with no lasting effects. There is no antidote. Treatment is purely supportive.
As little as one milligram of ricin may be enough to kill an adult. As little as one ingested bean may kill a small child, although the reported lethal doses for children and adults are closer to three beans for children, and four to eight beans for an adult.
Ricin is used by criminals for homicide. A Bulgarian journalist was assassinated by having a metal pellet containing ricin injected in his leg. In 2003, someone mailed an envelope containing ricin to United States Senator Bill Frist in an apparent attempt at assassination. Terrorists and criminals have been caught manufacturing, hoarding and attempting to use ricin. Castor beans have one useful application. They yield castor oil, which contains no ricin as ricin is not oil-soluble. Castor oil is used for medicinal purposes and as a dietary supplement.