Tuesday, 26 July 2011

The skin absorption myth

There is a myth around that ragwort poses a serious risk to human health.
Rumour abounds. This latest posting is stimulated by a statement made on Twitter.

Lovespoon Lovespoon Gelato
@fedupfarmer @hastillonlyme Re ragwort:a woman DIED last summer,having cleared her horse's field of it without wearing gloves.Hideous stuff.

The poster was challenged and could not provide the evidence. Various stories like this have been circulating the internet for years but there is never any evidence. A few years ago the government rejected a petition from the petitions website that made unfounded claims of several deaths. It is also significant that the poster made the error of thinking that ragwort is a notifiable weed. It was stories like that that led to the complaints to the Advertising Standards Authority recently.

What does the science tell us? There is a very good report on this on the internet written by Dutch ragwort expert Esther Hegt and Dr Pieter Pelser. Dr Pelser is a world authority on ragwort and actually has a Phd on the plant.

This is what they have to say on the matter:

2) Report on the internet by Dr. Knottenbelt (Liverpool University). This veterinarian is quoted on the internet quite a lot, because he stated, during a debate in the House of Commons, that the toxic substance in ragwort can almost certainly be absorbed through the skin (6). In response to this we contacted Dr. Knottenbelt. Through an email he informed us that there is no scientific proof for his statements. He writes that he himself has suffered liver damage after manually removing ragwort plants. The results of this ‘experiment’ have not been published and, according to us, are not obtained through a good scientific trial.

Through our research about the sources of the reports on the danger of touching ragwort, we conclude that there is no substantial evidence that there is a health risk for people. The amount of pyrrolizidine alkaloids that might be absorbed through the skin is very low and there is no proof that these alkaloids are being changed into a toxic form. Ragwort can cause an allergic skin reaction upon contact; compositae dermatitis (7). This allergy can appear after touching or eating the plant. This allergy is not caused by the pyrrolizidine alkaloids but by other substances that are common in many of the members of the Sunflower family (sesquiterpene lactones)(8).

So basically it is a non-story. There is no evidence that this ever happens.
Ragwort Hysteria latest entries

No comments:

Post a Comment