WASHINGTON -- An envelope addressed to President Obama and intercepted at a mail processing facility has tested positive for the poison ricin, a law enforcement official said Wednesday.
Officials are conducting additional tests to confirm the result, said the official, who was not authorized to speak to the press because the tests are part of an ongoing investigation. Investigators believe the letter to the White House may have been sent by the same person who mailed a suspicious envelope to Sen. Roger Wicker (R-Miss.).
What is ricin?
Here's a look at ricin, a poison made from waste remaining after castor beans are processed into oil.
How it works: Ricin gets inside cells and prevents them from making proteins. Without proteins, cells die. Forms: Powder, mist or pellet. Methods of exposure: Ingestion, inhalation or injection. Symptoms: If inhaled, respiratory distress, fever, cough, nausea, sweating, fluid buildup in lungs. If ingested, vomiting and bloody diarrhea, seizures, hallucinations. Symptom onset: If inhaled, possibly within eight hours. If ingested, typically less than six hours. Results: Low blood pressure and respiratory failure; spleen, liver and kidney malfunction, leading to death. Time of death: Could be 36 to 72 hours, depending on the dose and method of transmission. Treatment: No antidote or specific vaccine, but effects can be treated.
Source: Centers for Disease Control and Prevention.