SIR, — Mr Roger Thornhill, who claims that he has not seen ragwort on Harpenden Common (Herts Advertiser, March 20), has clearly either never walked on the common or would not recognise ragwort if he did see it. For his information it is that bright yello

SIR, - Mr Roger Thornhill, who claims that he has not seen ragwort on Harpenden Common (Herts Advertiser, March 20), has clearly either never walked on the common or would not recognise ragwort if he did see it. For his information it is that bright yellow flower, and yes it most certainly is a problem.

He has obviously swallowed the Countryside Management Service (CMS) propaganda hook line and sinker. Unfortunately he was so eager to rush into print to defend their honour that he neglected to check the facts. I would suggest he, and anyone else who believes the "ragwort is only toxic to horses" misinformation circulated by CMS and St Albans District Council, reads the research on this plant published in scientific journals worldwide - common ragwort (Senecio jacobaea) contains pyrrolizidine alkaloids, and is one of the most frequent causes of plant poisoning of livestock in Britain. Ragwort is most certainly not "only dangerous to equines". The toxin is cumulative and irreversible and as it builds up in the body, results in liver failure. This is why Parliament has made it subject to legal control (Weeds Act 1959 and Ragwort Control Act 2003).

It has also escaped Mr Thornhill's attention that toxins are not only ingested but can also be absorbed into the bloodstream through the skin and inhaled. Humans may be at serious risk of ragwort poisoning through direct contact by touching the plant or by breathing in large quantities of pollen. Anyone handling ragwort should wear protective gloves and if in regular contact with flowering ragwort, is advised to wear a dust mask with pollen filter.

The only positive achievement of CMS appears to have been to unite the community in opposition to its activities. However, perhaps Mr Thornhill could explain to the unenlightened precisely why we need the CMS when the British countryside has been managed perfectly well by our farmers for hundreds of years?

RHODA HARRISON,

Eastmoor Park, Harpenden.