Friday, 24 June 2011

Germaine Greer on ragwort hysteria

For the choice of bad information based on the hysteria today. I chose a comment made today in the comments made by the public below a Telegraph article by Germaine Greer.
This leads on to Dr Greer's, previous articles on the subject.

The comment is
"The biggest drawback of not cutting verges is the growth of ragwort, the pretty yellow flower that seeds, the seeds blow for miles in the wind and recolonise elsewhere.
For the uninitiated, ragwort is a killer, it is toxic to equines.
It can also bring out a very nasty rash in humans. "

It is quite true that ragwort in common with many members of the daisy family can cause a rash in sensitive individuals but it is certainly unlikely that ragwort is going to spread for miles on the wind. In fact it has been studied and we know both from the physics and from real life studies that most seeds fall at the base of the plant and the rest almost entirely fall to the ground just a few yards away.
See Ragwort - How far do the seeds disperse?

Here is Dr Greer's previous article which shows an admirable level of rationality. She is obviously no slouch mentally. Back in 2002 she wrote this as a result of a torrent of abuse received because she mentioned ragwort's positive qualities. This is not uncommon. If you try to tell some of these people the facts they just get emotional and attack you with bad evidence.
I previously documented an example where leading European ragwort expert Esther Hegt tried to comment in an on line forum only to be met with ignorance and bigotry.

If the first torrent of letters to the Weekend editor had betrayed careless reading, the succeeding waves gave no sign whatsoever of first-hand acquaintance with my column. Though I said that I was well aware that Senecio jacobaea is a serious threat to the health of horses, she was asked in the testiest tones whether the silly woman (in other words me) knew that hundreds of horses and even dogs died of ragwort poisoning every year.

Oh dear! We have the "it poisons dogs" myth again. It is poisonous to dolphins too. They don't eat it either!

As a matter of fact I don't know this, and I doubt whether anyone else does. Any attempt to discover actual numbers of beasts dead of liver damage caused by ingestion of ragwort is doomed to founder. In Scotland the incidence is monitored by the Scottish Agricultural Disease Surveillance Centres, which recorded zero deaths in the year 2000 up to July, and three in 1999, all cattle. Cases are commoner than these figures suggest, but they are not so common that vets treating sick horses will immediately suspect ragwort poisoning, nor, if they suspect it, can they verify it, because there is no reliable clinical test.

We have more UK figures since this and they confirm ragwort poisoning is rare.As do the international figures. Dr Greer is quite right to use them.

Without an autopsy, ragwort poisoning cannot be securely identified as the cause of death, which might explain why people anxious to assure me that senecio species are a plague can say only that "up to 500" horses - that is something between zero and 500 - are killed by ragwort each year.

In over a decade of study I have seen no evidence for that 500 figure. It gives every appearance of being conjured out of thin air. Within a short time the same sources were saying 6,500. I will have more to say about this in a few days time.
It will be exposed for the nonsense that it is.

What we do know is that only horses that have eaten everything else in their fields will eat live ragwort, and if dried ragwort were not included in hay and silage there would be no problem. Yet some of my correspondents believe that "inhaling seed or spores" of live ragwort will begin the poisoning process. How has this ragwort hysteria taken hold?

Spot on Dr Greer BRAVO! Ragwort is a flowering plant it has seeds not spores. It is hysteria.
I recently blogged on this nonsense about inhaling seeds which is still in circulation.
I called it tripe and it is
Ragwort Hysteria latest entries

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