Could Organophosphate Insecticides
Play A Role In Madcow Disease?
By Elizabeth Piper

SOMERSET, England (Reuters) - Mark Purdey still eats beef, even "junk'' in pies and hamburgers, and he has no fear that he or his wife or six children will be struck down by the deadly human form of mad cow disease.
``It's an absolute myth,'' the 48-year-old organic farmer says, banging his fist on a large wooden table to underline his argument that much of the accepted logic on bovine spongiform encephalopathy, or BSE (news - web sites), is wrong.
His story unfolds -- a 16-year campaign to explore the effect of organophosphates, the chemicals he believes are behind the spread of the brain-wasting disease in cattle and in people.
Purdey says we should distance ourselves from ``the men in bow-ties'' who have what he calls a monopoly on thought.
Forget the role of tainted animal feed in spreading BSE among cattle or infected meat in passing the disease to humans as new variant Creutzfeldt-Jakob Disease (news - web sites) (vCJD).
Look instead at the use of systemic organophosphates, derived from military nerve gas, which the UK agriculture ministry told farmers to pour along the spine of their cattle in the early 1980s to kill a parasite called the warble fly.
And those used in sprays used in Britain's countryside.
``I have been hammering the establishment theory, the so-called meat-and-bone meal theory, since 1988 or 1989. Even then I had identified that meat and bone meal had been sold all over the world, particularly the Middle East,'' he says.
``If you're blaming this stuff and you're sending it all over the world, why on earth aren't you getting more BSE?''
He agrees that other scientists would argue it has yet to appear because of the long incubation period of disease, believed to be caused by a mutated prion protein in the brain.
But Purdey argues there is little logic in the theory.
He also disputes the argument that BSE is passed to humans via infected beef.
``If it was to do with eating beef we'd have lots of cases in towns, where most burger bars are, but 60 percent of cases are in rural areas,'' he said.
``Most victims live by fields, where crops are sprayed.''
Self-Taught Scientist
A self-taught scientist, Purdey says he acted first on ''intuition,'' refusing to treat his 60 cows with the organophosphate, called phosmet, and going on to win a court battle with the agriculture ministry to make his point.
When BSE was first detected in a British herd in 1986, he immediately thought phosmet was the problem -- a theory which after years of unpaid research has now won respect from senior scientists, public figures and politicians.
``Like most things it was instinct. Being a farmer, I was horrified when I was approached by a ministry official to treat a cow for warble fly by pouring this chemical along the spinal cord and the base of the head,'' he said.
``It was an oil designed to seep through the skin and to change the entire internal environment of the cow into a poisonous medium to kill off the parasites.''
Purdey began to trawl through books and do field research.
He looked at the clusters of BSE in Britain, clusters of deer and elk in the United States with a similar illness called chronic wasting disease, and villages where many people were dying of the more common Creutzfeldt-Jakob disease (news - web sites).
``I went on the road,'' he said, describing trips to the United States, Slovakia, Calabria in Italy and Iceland.
``To me it was clearly something in the environment that was igniting these illnesses. But what was this factor?''
He found one common factor -- high levels of manganese, a metal given to cattle in high doses via the organophosphate.
``What I found in the environment was supported by the laboratory,'' he said, describing tests by David Brown, a neurobiologist at Cambridge University.
Purdey explains the prion would normally bond with copper and carry it around the brain to destroy free radicals. But if lacking copper, the prion bonds with another metal -- manganese, which stops the prion from folding properly.
He did soil analysis on the areas near clusters of vCJD in Britain and found high levels of manganese from crop spraying. He concluded the doses of manganese intensifies the traditional illness, giving vCJD the potency to kill younger people.
Funding Required
Now all he wants is funding for more research -- something that Agriculture Minister Nick Brown says may be ready in May after a scientist has reviewed all work into the origins of BSE.
``In the BSE inquiry there is a caveat that it is not clear whether organophosphates could have been a contributory leaves the door open on organophosphates,'' Brown told Reuters.
But Purdey is worried that the funding may never come.
``No one's prepared to admit it because it would involve massive compensation,'' he said. ``By keeping the causal agent as something mystified, no one's to blame.''

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