A farmer holds castor beans. Ricin occurs naturally in castor beans. (Marla Dickerson / Los Angeles…)
By now you've probably heard, read, or seen that a letter addressed to President Obama has tested positive for ricin powder, a deadly poison that can lead to death within 36 to 72 hours.
But what exactly is ricin and why is it so deadly?
Ricin is a protein that is found in castor beans. Chewing castor beans--which are grown all over the world--is not a good idea, and the ricin found in them could make you very sick, but it won't necessarily kill you. It is the ricin that has been extracted from the beans during the making of castor oil that is especially deadly.
GRAPHIC: Ricin poison explained
This concentrated ricin--which can be turned into a powder, mist, pellet or dissolved in water--kills people by killing their cells. It gets absorbed into individual cells, and then starts preventing the cells from making the proteins they need to survive. The cells die, and ultimately the body's systems fail, and death can occur.
There is no known antidote to ricin poisoning, according to the CDC. However, ricin poisoning is not contagious.
The symptoms of ricin poison differ depending on how a person came into contact with the poison. If it is inhaled, it's the respiratory system that will be affected initially. A person would experience trouble breathing, fever, cough and nausea, a build up of fluid in the lungs, and eventually respiratory failure.
STORY: Letter sent to Obama tested positive for ricin, official says
If the poison is ingested, the initial symptoms would be vomiting and diarreah, leading to severe dehydration, low blood pressure, and eventually the failure of organs like the liver, spleen and kidneys.
Ricin is unlikely to be absorbed through normal skin.
But ricin poisoning it is not something the general public should worry about, said James Ramgoli, who heads security for the North Shore-LIJ Health System. He noted that it is difficult to make ricin into a powder fine enough to disperse in the air at the slightest disturbance--like the tearing open of an envelope--so that it might be inhaled.