Pontifications on Poison
Being some ramblings on events associated with poisonous plants.
Saturday 24th December 2011
Reports in the press that one of the UK’s leading visitor attraction had been selling ‘ethnic’ jewellery made of highly toxic seeds raised two questions; how on earth did these products get onto the gift shop shelves and are these seeds as dangerous as the press reports state?
News that the Eden Project had withdrawn from sale bracelets made of highly toxic plant seeds first came from BBC Cornwall and was then carried by other outlets including the Telegraph and the Daily Mail.
The Eden Project says it has been stocking the item for up to two years and it has sold 2,800 of them. The bracelet is made of seeds of Abrus precatorius, a tropical vine with a number of common names the most often used of which are jequirity bean and rosary pea.
The bracelets, made in Peru, were purchased from Rainstick Trading, a company in Suffolk. There is nothing exactly matching the picture of the bracelet used in the news reporting on the company’s website at the moment and there is no reason to believe the company knew what the bracelets contained. There is a ‘Natural seed bracelet’ made up of a number of different coloured seeds some of which match the red of the rosary pea but that does not mean that there are Arbus seeds.
Abrus precatorius contains the toxic lectin, or toxalbumin, abrin, and much of the reporting points out that abrin is similar in structure to ricin the toxin in Ricinus communis. None of it mentions that this means it is also similar to insulin.
But, to turn to the first of my two questions. How does it come about that the Eden Project and, it is believed, a number of other retailers in the UK had this bracelet for sale? Perhaps, nobody realised that these seeds could be harmful. A quick look at my four ‘go to’ books suggests this is highly unlikely.
The International Poisonous Plants Checklist cites twenty references to it and the first in the list is a 1955 paper J.N. Ransohoff entitled ‘Abrin, Lethal Jewelry’. Wink and Van Wyk, in ‘Mind-altering and Poisonous Plants of the World’ say ‘Abrus seeds are widely used as beads in necklaces, toys, musical instruments, masks and decorations’. They go on to say that dermatitis as a result of wearing the seeds in jewellery is known to occur. Elizabeth Dauncey, in 'Poisonous Plants: a guide for parents and childcare providers' says ‘the distinctive seeds are imported in jewellery, rosaries and musical instruments (e.g. inside maracas)’ and Amy Stewart, in ‘Wicked Plants’ says they are ‘popular beads for jewelry making’.
And just as all papers about ricin refer in the introduction to its alleged potential as a bioweapon so, it seems, all papers about abrin include in the introduction that the seeds are often used in jewellery and beadwork.
So, it is rather hard to understand how someone buying products for the Eden Project gift shop (and for that matter the buyer at the importing company as there is no reason to believe it was aware of the type of seeds being used) could not know that some bead products are made with toxic seeds and, therefore, checks should be made on the seeds being used in any such product. It seems this matter only came to light when one of the venue’s horticulturists saw the bracelets in the shop. Efforts are now being made to recall the 2,800 bracelets that have been sold.
What seems like extremely ill-advised purchasing may, however, have another explanation. It could be that the importer and the buyer felt that the harmful reputation of rosary pea is overstated, which brings us to my second question; are these seeds as dangerous as the press reports state?
Like many seeds, for example Taxus baccata, yew, the seeds of Abrus precatorius have an indigestible coating and there are reports of them passing through the digestive system without causing any symptoms. It seems that it is necessary to chew the seeds for the toxin to be released. ‘Wicked Plants’, for example says that ‘a single seed, chewed well, would kill a person. Though Ms Stewart has a tendency to overstate the actual harm caused by poisonous plants in this case she seems to be followed the accepted wisdom because Wink and Van Wyk say the same thing with the caveat that this is especially the case with children.
Dauncey, however, notes that there are very few reported cases and I found one paper detailing the case of an intended suicide who had thoroughly crushed ten seeds and ingested the powder before thinking better of it and seeking medical care. The subject, a 27-year old male, suffered severe gastrointestinal symptoms but was fit for release from the emergency department after eight hours and a follow-up, a month later, showed no long-term effects.
The AAPCC NPDS annual report that I’ve written about and am still studying for further information has no reference at all the plant or to abrin. The plant sub-category ‘Toxalbumins’ only has 167 single exposures recorded against it with none having a ‘Major’ outcome and only five producing a ‘moderate’ outcome. I also checked back with previous NPDS reports since 2004 and found no specific mentions of the plant or the toxin and the sub-category figures for ‘Toxalbumins’ show that 2010 was a typical year.
The Eden Project product recall page includes information from the Health Protection Agency 'seeds are not expected to cause serious problems if swallowed whole and not chewed' and notes that, even if crushed or chewed the toxin needs to be 'fully absorbed' for any potentially fatal poisoning to occur.
So, it does seem that, as so often happens, there is a wide difference between the potential for harm from the abrin in rosary pea seeds and the actual harm caused both in terms of number of incidents and severity.
That is not to say that I think it is OK for these bracelets to be on sale. The whole point about avoiding harm from poisonous plants is to know what the potential is and deal with it sensibly. Buying a bracelet on the assumption that it would not be sold if there were any level of risk means you do not have the knowledge to make a reasoned evaluation.
The only people who would not be surprised to find Abrus precatorius seeds on sale in the Eden Project gift shop would be visitors from Germany. (The German word for poison is gift. I’ve waited years to use that joke. I probably should have waited longer.)
Actually, there is a better joke about this incident. The Daily Mail says in its headline that the beans are 'twice as toxic as RICIN'. Given that the Mail has previously reported that 'even a speck of [ricin] can kill someone' that must mean that half a speck of abrin would do the job.