Washington (CNN) -- An envelope that tested positive for the deadly poison ricin was intercepted Tuesday afternoon at the U.S. Capitol's off-site mail facility in Washington, congressional and law enforcement sources tell CNN.
After the envelope tested positive in a first routine test, it was retested two more times, each time coming up positive, the law enforcement source said. The package was then sent to a Maryland lab for further testing.
The envelope was addressed to a U.S. senator, though the sources would not say which one.
Ricin is a highly toxic substance derived from castor beans. As little as 500 micrograms -- an amount the size of the head of a pin -- can kill an adult. There is no specific test for exposure and no antidote once exposed.
http://www.cnn.com/2013/04/16/us/tainted-letter-intercepted/index.html
After the envelope tested positive in a first routine test, it was retested two more times, each time coming up positive, the law enforcement source said. The package was then sent to a Maryland lab for further testing.
The envelope was addressed to a U.S. senator, though the sources would not say which one.
Ricin is a highly toxic substance derived from castor beans. As little as 500 micrograms -- an amount the size of the head of a pin -- can kill an adult. There is no specific test for exposure and no antidote once exposed.
http://www.cnn.com/2013/04/16/us/tainted-letter-intercepted/index.html