Results add weight to OP-BSE theory

7 February 1997

Results add weight to OP-BSE theory

By Liz Mason

FRESH trial results have provided preliminary evidence to back a Somerset farmers theory that BSE is linked to exposure to organophosphate chemicals.

Taunton dairy farmer Mark Purdey says laboratory tests, carried out by a scientist from the Institute of Psychiatry, London, demonstrate that levels of the OP chemical phosmet, as low as two parts per million, can induce a dramatic reaction inside living cells.

The cells used in the trial express prion protein (PrP), the abnormal or misshapen form of which is found in the brain tissue of all cattle clinically affected with BSE.

"The reaction is proportional to the phosmet dose and involves abnormal movement and distribution of PrP within the cell," said Mr Purdey. "This could indicate either a trigger or susceptibility to the prion disease."

The results are only preliminary but they show a dramatic effect, he added. Further tests are needed to find out whether the abnormal or misshapen PrP is the same as that produced as a result of BSE.

Mr Purdey has consistently claimed that exposure to OP chemicals, particularly the high-dose OP phosmet, used in MAFFs compulsory warble fly eradication campaign, is linked to BSE.

And it has emerged that the governments BSE advisory committee, SEAC, is to take another look at the evidence behind the theory.

But MAFF, says the move, which was a SEAC decision and has not been scheduled, does not change its view that past examination has found no evidence of an OP-BSE link.

A MAFF spokesperson said Mr Purdeys ideas had been examined in detail by scientists from MAFF, the Department of Health, the Neuropathogenisis Unit, Edin-burgh, and the Medical Research Council (MRC). But all of them found difficulties with various aspects of his theory.n

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