Toxic subject

SIR, - In her letter (Herts Advertiser, March 27), Rhoda Harrison somewhat patronisingly offers me advice on identifying ragwort - not needed as it happens as I have spent many days as a conservation volunteer, wearing gloves, and pulling ragwort on commons (but not on Harpenden Common and not with Countryside Management Service).

She attempts to convince the reader of her expert knowledge by referring to the plant's Latin name, and quoting references to Government Acts. She also claims that research published in scientific journals worldwide supports her claim that ragwort is highly toxic to species other than equines, including man. An internet search reveals a somewhat different picture.

In her letter Rhoda Harrison defends her description of common ragwort as being highly toxic, and references readers to the 2003 Ragwort Control Act. This Act amended the 1959 Weeds Act by allowing for a Code of Practice to be inserted into the earlier legislation, and the "2003 Code of Practice on How to Control the Spread of Ragwort" ensued, agreed between DEFRA (Department for Environment, Food and Rural Affairs) and the British Horse Society. This document contains the following two passages:

"Ragwort is a native species of the British Isles. It is a specified weed under the Weeds Act, 1959. It contains toxins which can have debilitating or fatal consequences, if eaten by horses and other grazing animals. Ragwort is less likely to be rejected by stock if dried and contamination of forage (hay, haylage and silage) is a particular problem. Humans may be at risk from ragwort poisoning through direct contact (e.g. hand pulling) or the consumption of contaminated food. Research undertaken for the Government in the 1990s suggested that the risk to human health in the UK through the contamination of staple foods i.e grain, milk, eggs and honey is likely to be insignificant.

"This code does not seek to eradicate ragwort. Ragwort, as a native plant, is very important for wildlife in the UK. It supports a wide variety of invertebrates and is a major nectar source for many insects. In many situations ragwort poses no threat to horses and other livestock. It is a natural component of many types of unimproved grassland and is used by some invertebrate species that have conservation needs. However it is necessary to prevent its spread where this presents a high risk of poisoning horses and livestock or spreading to fields used for the production of forage. A control policy should be put in place where a high and medium risk is identified."

I now accept that in some situations humans can be in danger from contact with ragwort, but that the risk can be minimised by using appropriate protective gear. However it is clear Rhoda Harrison grossly overstates the dangers of ragwort to humans. I accept her word there is some ragwort on Harpenden Common, but at a level I believe is not a cause for concern and is to be welcomed.

ROGER THORNHILL,

Ambrose Lane, Harpenden