Tuesday, 8 April 2014

Chorleywood Parish Council's Ragwort Error

  A good illustration of the rampant misinformation about which I blog was given by Chorleywood Parish Council with this tweet.
Apr 3
Ragwort poses a serious risk to horses, our Rangers and volunteers remove it from the Common each year, depending on the growing season
The problem is quite simple.  Ragwort does not pose a serious risk to horses in the way in which they describe and they are doing damage to the biodiversity of the common.

The issue is that a lot of people have got hot under the collar for no reason other than being fed false and invented information about ragwort.
For details see this blog posting Ragwort they made it up

We have the statistics. We have the science. We have the information. Ragwort is poisonous but it is not normally a serious risk to horses.

Let's just remember when complaints were made about companies who were repeating the nonsensical hysteria that has been put around. The Advertising Standards authority, who are impartial and independent took action and the adverts were stopped. See British Horse society rapped by Advertising Standards Authority

Ragwort poisoning occurs because horses are abusively starved into eating it or because it is present in significant quantities in hay. They instinctively avoid it when it is growing.

One of the prominent myths is that every tiny piece of ragwort that might be ingested causes harm. Well if you'd spent as much time as I have pouring over books and scientific papers as I have you would know this isn't correct. There are many things which serve to prevent this.

One important example of the factors which prevent low doses of the alkaloids in ragwort from causing harm can be explained by a parallel with paracetemol.
Paracetemol is harmless at low doses and a liver poison in overdose.
It is prevented from poisoning the liver by a chemical called glutathione.
In overdose the body's store of glutathione is used up and poisoning begins.

Glutathione is one of the chemicals which interacts and inactivates the toxic
breakdown products of the alkaloids in ragwort and it is not the only factor.

One of the things that often comes up when discussing it is what about Defra's advice. There are several reasons why you should be cautious about this.

First believing in an authority like this just because it is an authority is one of the worst possible errors you can make in science. It is so old an error it has several Latin names.  One is, "ipse dixit", apparently referring  to the followers of Pythagoras.  It means, "he himself said it".  It doesn't matter who says something it is the evidence that makes something right not the source of the information.

In fact, Defra have messed it up badly. In short they haven't a clue!
I blogged before about it as Defra ragwort code of practice nonsense.
and boy is it  nonsense. Their statistics wouldn't get a GCSE pass!
Click on that link and you will see that I have an explanation and an expert saying that if you do something like that then,"you're an idiot". It is rare  you can say this in science but their treatment of the evidence is utterly crazy.

The final reason for not stating that people should follow authority is that those in the know will think badly of your abilities or even that you may have something missing upstairs. It has been well studied and a personality trait of following authority is well established to be linked with decreased intelligence, what is more there is some pretty good evidence that this is associated with having fewer brain cells in a certain part of the brain.

For more information there are these two websites.

Ragwort facts

Ragwort myths and facts

The last of these two sites is written by someone who was originally a member of a ragwort extermination group, but she studied the scientific evidence and now debunks the evidence with the help of a stellar cast of international experts.

Finally as ragwort is one of the most important wildflowers for biodiversity. You can read about this here.

Ragwort weed or wildflower.

Ragwort Hysteria latest entries