'No cause for alarm' over castor trees

There was absolutely no cause for concern over the presence of castor trees in Malta, toxicologist Michael Sammut said yesterday.

Dr Sammut was contacted for his reaction following the discovery of small amounts of ricin in a London apartment last week, sparking fears that a bio-attack in Britain was in the pipeline.

Ricin is derived from the bean like seeds produced by the castor trees, which are very common in Malta. According to Reuters, ricin, one of the deadliest naturally occurring poisons, is a toxin derived from castor plant beans. Castor beans are grown worldwide and are used to produce medicinal castor oil. The mash left behind after the oil is extracted contains a small percentage of ricin.

"There is absolutely no cause for alarm from having trees here. One needs a chemical process to extract ricin and the process is not easily available to the layman," Dr Sammut said.

Dr Sammut said there were many plants, including several imported indoor plants as well as wild-growing mushrooms, that were more dangerous than castor plants.

"All plants producing milky sap are poisonous. People have to learn that they should not try to mess about with or eat things they don't know.

"Oleander, diffenbachia, winter cherry and ponsiettas, for instance, produce poisons, some of which could be potentially fatal if consumed. In the case of oleander, if its branches are burnt, the fumes are toxic too. People have to be careful and cautious and not do anything if they are unsure of what the results could be," Dr Sammut said.

Asked if there were any risks if seeds ended up in wells or if substances could make their way into the water table, Dr Sammut said ricin was not soluble in water.

If there was any risk from the castor oil tree, it was that children might be tempted to eat the shiny seeds, he added.

"There were individual cases with children eating some seeds a few years back but there were no deaths," Dr Sammut said.

Specialists who studied toxic plants wrote that if thoroughly masticated, the seeds could produce serious poisoning and death. A case reported in scientific journals shows that a person was killed in 1935 after eating some 20 seeds. There were several cases of poisoning after eating seeds but none resulted in death.

Botanist and university lecturer Edwin Lanfranco said the castor oil tree was introduced in Malta, probably as an ornamental tree, in the middle of the 19th-century.

"It is a very prolific tree and has spread immensely. An attempt to eradicate it was made by the environment department because it is not an indigenous tree and also because of its potentially poisonous beans but it is very difficult to eradicate.

"The trees produce a lot of seeds and it has a very good germination rate. The seeds are also easily carried with water downstream and that is why it has spread so much," Mr Lanfranco said.

"It is widely known that the seeds contain a toxic substance but because of their appearance the seeds are very attractive to children.

"When I was still a teacher at Hamrun Lyceum, a student ate some seeds and when I realised what he was doing I had stopped him. He is still alive and became a doctor," Mr Lanfranco said.

"It is not easy for anyone to eat a lot of the seeds and I suspect it is not very tasty, but I never tried it," Mr Lanfranco said.