It is that time of year, again. The time when those who celebrate Christmas decorate their homes with a variety of natural and manufactured articles and reports appear about the dangers posed by the natural decorations. Oddly, there is hardly ever a mention of the potential harm that the manufactured products could cause.
I’ve written before about Euphorbia pulcherrima, poinsettia, and the confusion many people get into over the difference between something being poisonous and being harmful. Again, this year, I’ve seen pieces asserting in the strongest possible terms that poinsettia is not poisonous because you would have to eat a great deal of it before getting sick.
And, of course, mistletoe has been mentioned; both European mistletoe, Viscum album, and the American varieties from the Phoradendron genus. One piece I read claimed that mistletoe has a range of curative properties so it is worth saying that it doesn’t have any verified medicinal uses.
The third of the Christmas plants is Ilex, holly, and it was this that the Illinois Poison Center Blog decided to focus on for its ‘beware at Christmas’ post. In Europe the aquifolium species is the most common but in the USA it is the opaca that people bring into their homes. I was very disappointed by the piece. I know that some authors who write about poisonous plants like to overstate their case in the hope of boosting readership but I would not expect a Poison Control Center (PCC) to engage in spin.
The Illinois PCC says that in 2010 there were ‘877 reported cases of human exposures to Ilex group’. Further down it says;
‘From 2001 to 2010, the US Poison Centers reported 20,601 cases of human exposures to the plant.’
I don’t really see the need to aggregate ten years’ worth of results. There may be wide year on year fluctuations but a yearly average would be what I’d expect to see and I can’t help fearing the ten year cumulative was chosen because it is a nice big number.
The raw figure does not tell us anything about how these exposures occurred. Ilex is one of those plants that some people believe to have almost magical medicinal properties and tea made from the leaves is recommended by snake oil salesmen. Having seen case reports I know that these teas sometimes cause poisoning so I have no doubt that some of cases reported to PCCs are related to this route of administration. I have not seen any recent case reports for anyone eating the plant when it was in the home at Christmas.
It is worth looking at what is meant by ‘reported cases of human exposures’. The 2010 National Poisons Data Service (NPDS) Annual Report from the American Association of Poison Control Centers (AAPCC) logs calls to centres as ‘case mentions’. These include people who are calling for information and those where the exposure has been limited. For plants it gives 53,295 case mentions but only gives ‘outcomes’ for 15,863 suggesting that the rest did not involve any actual poisoning. Even that number doesn’t reflect true harm because in 10,025 cases the outcome was ‘none’. Less than 1,100 cases caused moderate symptoms or worse and there were only 2 deaths. And this is for all plants including the many that are far more toxic than holly.
Returning to poinsettia, the NPDS says 750 'case mentions' concerned poinsettia and we know that none of those resulted in any significant poisoning. The way we know this is that, because of its history, a single incident of poisoning by poinsettia would be very widely reported.
It seemed to me that, by suggesting that there were around 2,000 poisonings a year due to holly, the Illinois PCC was doing a disservice to the public but then I saw a tweet from the AAPCC that made me think there was something else going on.
The AAPCC tweet began;
‘More than 40,000 people die every year from unintentional poisonings.’
That struck me as strange because the NPDS report for 2010 says it documented 1,730 ‘human exposures resulting in death’ but in only 1,146 was poisoning at least contributory to the death. Some searching found that the 40,000 figure comes from a 2009 study by the Centre for Disease Control and is total poisoning deaths includes drug overdoses of both prescribed and illicit substances. The majority of these deaths occur without any involvement of PCCs so I wondered why the AAPCC was using that figure.
Then I read the rest of the tweet;
‘Poisoning IS an issue. Funding is a necessity.’
Clearly, as with so many organisations, funding for PCCs is under threat and the AAPCC’s response to that seems to be to overstate its involvement in poisoning deaths in the USA.
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