earlier this week, ee. post office intercepted letters addressed to sen. Roger Wicker (R-Miss.) and Pres. barack obama that contained a mysterious white powder. the substance turned out to be ricin, a deadly toxin that can kill within days. but how dangerous were these attacks?
Ever since the obama administration was first warned about the dangers of new ricin attacks in 2010, it has requested regular updates on the white stuff and powder, from where it is produced to where it is shipped. in 2011 usa uu. Counterterrorism officials received word that the al Qaeda affiliate in Yemen was making efforts to obtain large quantities of castor beans, the plant source from which the toxin is produced. That same year, four American men, Frederick Thomas, Dan Roberts, Ray Adams, and Samuel Crump, were arrested for conspiring to poison hundreds with ricin and blow up government buildings.
The biology of ricin may explain the compound’s popularity among terrorists. A protein with two chains, ricin targets human ribosomes, the protein producers of human cells. the first chain binds to the ribosomal walls and opens them; the second enters the ribosome and stops protein synthesis. Without protein, the body loses its ability to function. As the main structural component of all cells in the body, protein is needed to form blood, regulate bodily functions, and perform other tasks essential to life. virtually all of the body’s hormones are proteins; For example, insulin, which is essential for regulating the metabolism of carbohydrates and fats, and progesterone, which is involved in pregnancy and the female menstrual cycle, are proteins.
However, for ricin to have any dangerous effects, it must first enter the bloodstream. one way is through direct injection, which is the way the bulgarian dissident journalist georgi markov was assassinated in 1978, by being shot from a micro-pistol apparently concealed in the tip of an umbrella by a member of the intelligence agency Soviet, the kgb. less than two milligrams of the protein, in its purified form, could kill. if not injected, ricin can be ingested (eaten) or, if sufficiently powdery, inhaled.
It only takes a small amount of ricin to kill. “When ingested through the gut, a little goes a long way,” says Dan Brown, a nutritional toxicologist at Cornell University. while it would take eight whole castor beans to kill an adult, 2,000 milligrams of the purified protein would be lethal if ingested.
however, if the ricin is simply placed in an envelope where it could be inhaled, brown says the poison is “not a weapon”. That’s in stark contrast to anthrax, which, as a bacterium, can be lethal when inhaled; in 2001, five people died from gun anthrax placed in mailed envelopes. Ricin, as a plant-derived compound, has little potential for biological warfare, says Brown: The toxin would have to be inhaled directly and over a long enough period to result in harmful exposure.
In the case of letters received by the Senate and White House Outer Mail Rooms this week, Brown says letter openers would have had to place their faces almost directly into the envelopes while opening them to experience negative effects. “Either that, or there would have to be a pretty big puff,” she adds.
If anyone should be concerned about the public health effects of ricin, says Brown, they should focus on ingestion. according to the usa Centers for Disease Control and Prevention, swallowing more than 2,000 milligrams of castor oil could cause death in as little as 36 hours. once a person begins to vomit and experience diarrhea, which would dehydrate the body and lower blood pressure to dangerously low levels, the victim’s liver, spleen, and kidneys would cease to function.
In developing countries, where people use castor beans for cooking and jewelry, the threat is particularly acute, says Brown. Although a castor bean, when whole, could theoretically pass through the entire gastrointestinal tract without causing harm, most are chewed or pierced (for the purpose of stringing the seed into a necklace). the poison could enter the intestine, where it would overcome the body’s barriers to toxins and wreak havoc.