At a July demonstration outside Hillgrove Farm, near Witney, activists initially noticed a chemical smell and yellowing of the 20-yard stretch of grass which serves as the centre for protest. Sixteen activists subsequently reported unexplained symptoms including nausea, sore throats, head pains and breathing difficulties.
Exposure to organophosphate pesticides may be one of the causes of Gulf war syndrome and of the severe illnesses contracted by farmers after using certain sheep dips. The owner of Hillgrove Farm, Chris Brown, dismissed suggestions that he had sprayed the verge. "I am not concerned at all," he said. " I don't know who did it."
"The protesters did not need to be there and locals are getting fed up with them," he said. "I don't honestly think it was spilt by accident. I have got a suspicion but I'm not foolish enough to say who my suspicions are about. They'll do anything to discredit me. Dimethoate is an outdated pesticide and not one we use anyway."
Sheila English, a protester who had eaten her lunch at the site, said: "The next day I had ulcers on my tongue. Three days later I got terrible pains in my throat and mouth and my air passages started to close up."
Another protester, who did not want to be named, said: "On the day after, I began to feel queasy and suffered with diarrhoea. I felt sick for over two weeks. I am usually a fit person and can shake off bugs easily."
Dr Robert Davies, who has treated 60 sheep farmers for low-level organophosphate poisoning, said dimethoate could have caused the protesters' symptoms.
"The symptoms described by the protesters are almost identical to those experienced by sheep farmers when they dip.
"Dipper's flu consists of symptoms including muscular aches and pains, general lassitude and lethargy, feeling awful, in some cases tightness of the chest, and mild depression."
The use of organophosphates against people harks back to military use. They were developed by the Nazis in the late 1930s as nerve agents and are precursors to the sarin nerve gas used in the 1995 Tokyo subway attack.
"It's very worrying if derivatives of military nerve agents are now being used as, how shall I say, weapons, if that indeed is the case," said Dr Davies. There was no agricultural reason for spraying the pesticide on the verge, he added.
West Oxfordshire's principal environmental health officer, Keith Dalton, who collected samples for analysis after the incident, confirmed the dimethoate found was dangerous.
"The analyst's opinion was that the levels were such that there may be possible health implications," he said. The council does not spray organophosphates. Police involved in supervising the protests are also concerned they may have been contaminated.
"From our enquiries we have no evidence of who put it there," said Superintendent Pauline Sydenham of Thames Valley Police. "It could have been the protesters for all we know. It certainly wasn't us. We're concerned about our officers in addition to those other people who were present," she said.
Christine Gosden, Professor of Medical Genetics at Liverpool University, has written to Jack Straw, the Home Secretary, whose weekend cottage is less than a mile from the farm, to press him to look into the health effects on police and protesters.Reuse content