Ricin: What Is It?

January 9, 2003
By Stephen White
 
RICIN is more potent than cyanide or cobra venom - just one gram could wipe out 36,000 people.

Victims die a horrible death from multiple organ failure. There is no known antidote for ricin which is 500 times stronger than cobra poison and 1,500 times more powerful than cyanide.

The poison can be easily made from widely available castor beans using basic, low tech equipment.

One expert said: "You do not need to be at A-level standard in chemistry to produce this."

It is estimated that four tonnes would kill half the people living in an area of 100 square kilometres.

Terrorism expert Mike Yardley said: "Ricin is one of the most powerful poisons known. It is much more powerful than cyanide. It has not been used as a weapon of mass destruction and is essentially a tool of assassination."

Ricin attacks the body by shutting down protein synthesis within the cells, killing them. It is so powerful that a just single molecule will destroy a cell.

It takes four to eight hours to incubate in the body after being inhaled or eaten.

Victims who breathe in ricin feel weak, develop a fever, cough, nausea and tightness in the chest and sweating.

Flesh eating lesions develop in the airways and cause respiratory and heart failure. Victims who swallow ricin have severe vomiting and diarrhoea as well as stomach cramps, fever, thirst, headache, sore throat and dilated pupils.

Those poisoned by large doses can die from shock after massive fluid loss through severe diarrhoea. The poison is administered in powder form and victims have to be soaked in detergent to wash it off, then clothed in paper suits.

Health workers treating victims will have to be decontaminated in the same way. But there is no cure and death for those badly contaminated comes around three days later.

Andy Oppenheimer, of defence information group Jane's, said: "The way to disperse it would be as a spray using a canister. If you were lucky enough to survive, you would be left with permanent lung damage. And you do not need very much to kill."

The symptoms are similar, but last longer that those from phosgene gas, used in the First World War, or modern nerve gases such as sarin which was developed during the Second World War and used in an attack on the Tokyo subway.

Twelve people died and 5,000 were injured in 1995 when religious cult Aum Shinrikyo left perforated bags of the gas at stations during the rush-hour.

Some of the dead were rescue workers who ran into the tunnels without protection from the gas which is 26 times more lethal than cyanide.

Sarin is a compound of chemicals and, like other nerve gases, is odourless, tasteless and diffuses very rapidly into the skin. After the Tokyo attack, David Veness, Scotland Yard's chief counter terrorist expert, ordered an overhaul of plans to cope with such an incident in London.

He set up a specialist police unit, equipped with protective clothing, which would be first on the scene.

Work is now being done on an antidote to ricin. Dr Ellen Vitetta, of the University of Texas Southwestern Medical Centre in Dallas, is working on a vaccine following research into anti-cancer drugs.

Because ricin destroys cells so easily and rapidly it could be used to kill cancer cells.

Ricin has two components - its B chain binds to cells allowing the second component, the A chain, to enter the cell and kill it.

Dr Vitetta's team genetically engineered three versions of ricin's A chain. They found that two of these versions protected mice against the toxin.

The animals survived exposure to 10 times the dose of ricin which killed unvaccinated mice. Dr Vitetta said the vaccine also has no side effects.

She told New Scientist magazine: "It's cheap, simple and protects wonderfully without side effects because it's a totally inactive protein."

She has applied for extra grant aid to allow for more testing.

Prof Mike Lord, head of toxin research at the University of Warwick, said: "Because of the possible threat of ricin as a terrorist weapon a vaccine would be useful. However, there is as yet no effective vaccine to protect against ricin."

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