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Pontifications on Poison

Being some ramblings on events associated with poisonous plants.

Friday 16th September 2011

I thought David Tredinnick MP was bad enough. It shouldn’t be surprising that in a group of 650 people, albeit people who are well-educated and, supposedly, capable of understanding the evidence about any situation before reaching a conclusion about it based on their underlying philosophy, there turns out to be one who supports homeopathy.

And not just homeopathy. Mr Tredinnick also believes in medical astronomy, whatever that is, and his particular contribution to the MPs’ expenses scandal was the discovery that taxpayers had funded the purchase of computer software based on this mumbo jumbo. But now along comes another MP with bizarre opinions, denying science.

Richard Benyon is the Conservative MP for Newbury. He is also a junior government minister; Parliamentary Under Secretary of State (Natural Environment and Fisheries), Environment, Food and Rural Affairs. But Mr Benyon doesn’t let his ministerial position stop him from stating his thoughts robustly. ‘I hate ragwort’ he posted on his Facebook wall before describing it as ‘a vile poisonous weed’ and saying ‘I am on the warpath for those who let this vile poisonous weed spread. Chief target at the moment is the Highways Agency’.

This was to accompany a photograph of the minister pulling up Jacobaea vulgaris whilst a, fortuitously placed, cow looks on. Unsurprisingly, his wall has received a number of comments about the use of such inflammatory language, especially as this does not reflect the position of his department as shown in the Code of Practice on How to Prevent the Spread of Ragwort (COP) issued following the Ragwort Act of 2003.

It is perfectly clear that the minister has not read this document, as much from the photograph as from Mr Benyon’s ill-judged comments. Here’s a 5-point guide to what the photograph shows Mr Benyon doing wrong.

1. The COP makes it clear that pulling needs to be thorough because ‘any root fragments not removed can produce weak growth’. The plant in Mr Benton’s hand seems to have little or no root attached to it.

2. With either pulling or ‘levering out’ the COP summary of control methods states ‘Best results when soil is wet’. Now, I grant that the sky is cloudy but Mr Benyon is not dressed for wet weather and his choice of trousers suggests he isn’t expecting to be in amongst wet foliage of any sort.

3. The COP also calls for arms and legs to be covered so wearing a short-sleeve shirt is not the recommended safe way to deal with the plant. It is worth taking a moment to consider the reason for that recommendation. Many people say it demonstrates that ragwort can be absorbed through the skin and that pyrrolizidine alkaloid (PA) poisoning can result from skin contact.

Providing a completely scientific rebuttal of that claim is a little difficult because there has been no proper research on the matter. Now, that suggests that it is not a problem worthy of investigation. We know, for example, that PA poisoning from honey is not a threat because it was of sufficient concern for research to be carried out. You can assume that skin absorption of ragwort has never been a realistic concern.

The other way to look at the question of skin absorption is by extrapolation from research on rats using a plant from the Symphytum genus, comfrey, also a source of PAs. That extrapolation leads to the conclusion that a normal human would need to maintain skin contact with 150kgs of ragwort to absorb a lethal dose of PAs.

What ragwort does have is other chemicals known to cause contact dermatitis in sensitive people. It is to avoid that possibility that the COP recommends covering up.

4. While the COP says ‘Arms and legs should (emphasis added)…be covered’ it says ‘Hands must (emphasis added) be protected by wearing sturdy waterproof gardening type gloves’. The use of ‘must’ rather than ‘should’ is because, in addition to any sensitivity to contact dermatitis, there is the chance of mechanical damage to the hands if pulling is carried out for any length of time.

5. The COP also says ‘A facemask should be used to avoid the inhalation of ragwort pollen’. As the photograph shows, Mr Benyon has decided against wearing a face mask; perhaps he was concerned it would spoil his photo opportunity. This suggestion of a facemask is another cause of a myth about ragwort. You will often read claims that you can die just from breathing close to the plant. In fact, the first published draft of the COP said, of facemask wearing, ‘to reduce the risk of hayfever’; nothing to do with PA poisoning.

The Internet age has made it much easier for anybody to obtain information about any subject but MPs are still at an advantage because they may have access to unpublished information and they have staff that can read all the available material and present them with a summary. This is even truer of a government minister and, given that it would not be unreasonable to expect the Parliamentary Under Secretary of State (Natural Environment and Fisheries) to be asked about ragwort, Mr Benyon would have been perfectly justified if he had asked his staff to provide him with the official view of ragwort control.

Had he done so, he would not have made a spectacularly stupid remark on a social network.

But, this is not really about ragwort. The idea of a parliamentary democracy is that the people elect representatives to undertake the study of issues affecting society on their behalf so that they can get on with their lives trusting their MPs to be informed.

Mr Benyon has demonstrated that such trust may be misplaced.