British police are searching for a batch of ricin, the highly poisonous plant toxin, following the discovery of traces in a London flat. They are also seeking three men, in addition to the six Algerians already being questioned.

Anti-Terrorist Branch police officers raided a one-bedroom apartment on Sunday morning, after receiving a tip-off, reportedly from the French intelligence service. They discovered castor oil beans, from which ricin is made, and some equipment. Tests at the UK's Defence Science and Technology Laboratories at Porton Down confirmed traces of ricin.

"But the important issue is that the material causing us concern is no longer there. We need to find it," a police source told the Guardian newspaper. The discovery comes after months of UK government warnings about potential terrorist threats to the public.

Pat Troop, the UK's deputy Chief Medical Officer, said: "Ricin is relatively easy to make. The beans are easy to find and relatively low-tech equipment is needed." Only a tiny amount of the toxin can be fatal. As little as 70 microgrammes - the weight of a grain of salt could kill a person.

Supermarket shelves

Ricin was used to assassinate the Bulgarian defector Georgi Markov in London in 1978. He was injected using the point of an umbrella and died within four days. The symptoms of ricin poisoning are similar to flu, including a high temperature and loss of appetite. Hospitals and doctors across the UK have been put on alert for signs of ricin poisoning.

The toxin must be inhaled, ingested or injected to take effect. But it is thought that it would be more difficult to mount a mass attack with ricin than with anthrax or botulinum toxin, for example.

"Ricin is easy to produce but more difficult to disperse than other agents," says Timothy Garden, former UK Assistant Chief of the Defence Staff.

John Eldridge, editor of Jane's Biological and Chemical Defence told The Times: "The primary aim of terrorists is to cause panic and fear, and the simplest way of doing this would be to put it in food, to infect something on supermarket shelves." However, ricin can be powdered and aerosolised, say some scientists.

Experimental vaccine

Ricin was reportedly found in caves in Afghanistan previously occupied by Al-Qaeda members. And the UK government has said it believes that Iraq holds stocks of the toxin.

There is no known antidote to ricin but in September New Scientist reported the development of an experimental ricin vaccine by Ellen Vitetta and colleagues at the University of Texas Southwestern Medical Center in Dallas.

Vitetta has applied to the US National Institutes of Health for further funding to test the vaccine against aerosolised ricin and hopes eventually to test the vaccine in people. "This stuff really frightens me," Vitetta said. "You get flu-like symptoms, then suddenly you're dead."
 
SOURCE: NewScientist.com on the 8th January 2003