Ten years after anthrax spores delivered in letters killed five people, injured 17, and raised fears about the safety of opening mail, four Georgia men have been charged with plotting to buy explosives and manufacture a deadly biological toxin: ricin.

Marines in protective suits prepare to enter a Senate office building to retrieve mail that could be contaminated by ricin in February 2004. (REUTERS)

The specter of bioterrorism, in which bacteria, viruses or toxins like ricin are deliberately released to kill or cause illness, no longer looms as large in America as it did after 9/11. Then, the anthrax-laced mail caused near hysteria.

But scientists say that we shouldn’t be so cavalier, as biological weapons are now easier to make at home than ever before.

After all, the product the four allegedly were producing is a highly toxic protein that is made from castor beans. Compared with anthrax, a much higher quantity of ricin is needed to have a significant impact. Ricin can also be inactivated much more easily than anthrax, which can remain lethal for decades.

But ricin can have a deadly effect if a person comes in direct contact with it, especially if inhaled or digested. There is also no antidote for it, although a victim can be saved by immediate medical attention, during which doctors would try to maintain air flow to the lungs.

In a cover story on Sunday, the New York Times Magazine described a bioterrorism attack this way:

It makes of the most mundane object, death: a doorknob, a handshake, a breath can become poison. Like a nuclear bomb, the biological weapon threatens such a spectacle of horror — skin boiling with smallpox pustules, eyes blackened with anthrax lesions, the rotting bodies of bubonic plagues — that it can seem the province of fantasy or nightmare or, worse, political manipulation.

Brett Giroir, a former director at the Defense Advanced Research Projects Agency, told the magazine that advancements in laboratory technology had made that fantasy much closer to real possibility than ever before.

“What took me three weeks in a sophisticated laboratory in a top-tier medical school 20 years ago, with millions of dollars in equipment, can essentially be done by a relatively unsophisticated technician,” Giroir said.

But the Post’s Checkpoint Washington blog reports that the chances these Goergians could have created a weapon of mass destruction was “tiny at best.”

The chances are tiny because the challenges involved in delivering lethal doses of ricin to mass numbers of people are great, and nearly insurmountable for amateurs. “No one has done it, as far as we know,” Raymond Zilinskas, director of theChemical and Biological Weapons Nonproliferation Program at the James Martin Center for Nonproliferation Studies in Monterey, Calif., told Checkpoint. “It is beyond the capabilities of anyone except professional weapons scientists.”

As for bioterrorism by mail, The Washington Post’s Ed O’Keefe reports that the Post Office is focused on bigger problems, and that workers are now so unconcerned by the threat of attack that they no longer wear the gloves and masks provided as a precaution.

They are trained, however, to be on the lookout for envelopes that appear to contain sharp objects, dust, no return address, an invalid Zip code, or weird writing. The USPS spends $101 million each year to screen every piece of first-class mail sent or received by U.S. households and mail sent to federal addresses in Washington.