Updated Wed, Apr 17, 2013 9:17 pm
An Ohio University forensic chemistry professor says the letters tainted with what preliminary tests indicate is ricin, does not pose a widespread threat to public safety.
“I would say it really isn't cause for alarm,” Peter Harrington, professor of forensic chemistry said. “But I think it does get sensationalized in the news and scares a lot of people.”
Harrington said the letters are not an effective means of spreading the deadly substance.
“It is actually a challenge because if you think about it during the mail process the powder gets pressed into the envelope,” he said. “So it all depends on if you open the envelope up very vigorously then you might a chance for the powder to be dispersed in the air.”
Preliminary test results on two letters came back positive for ricin. Harrington said mail handlers are at the most risk for exposure.
The letters were postmarked Memphis, Tenn., on April 8.
One was sent to President Barack Obama. The other was sent to Mississippi Republican Sen. Roger Wicker.
Experts say nearly all cases when early tests show the presence of ricin turn out to be false alarms.
A draft of a 2010 Homeland Security Department handbook lists only one person killed by ricin. That was a political assassination of a Bulgarian dissident in 1978. He was injected with a ricin pellet by way of a specialized secret-agent-style umbrella.
Ricin is derived from the castor plant which is used to make castor oil.