§ Lord Lester of Herne Hillasked Her Majesty's Government:
Whether they will make public funds available for experiments testing whether the drenching of cattle with organophosphate pesticides to eliminate warble fly treatment may have made the animals' brains more susceptible to attack by prions, thereby contributing to the cause of BSE, and if not, why not.
Lord LucasThe theory that Bovine Spongiform Encephalopathy (BSE) could have been caused by the exposure of cattle to organophosphate (OP) pesticides as a treatment for warble fly infestation has been considered in detail by scientists in the Ministry of Agriculture, Fisheries and Food, the Department of Health and the Medical Research Council. A report 161WA from the Spongiform Encephalopathies Advisory Committee (SEAC) entitled Transmissible Spongiform Encephalopathies A Summary of Present Knowledge and Research (HMSO ISBN 0–11–242–9874) included an analysis of the theory. The report notes that the original epidemiological investigation considered any possible association between the use of agricultural chemicals, including OP insecticides, and the occurrence of BSE. None was found. The lesions of delayed neurotoxicity induced by OP compounds are clearly distinguishable from those in BSE. Many other countries without BSE use OP compounds on cattle and contrariwise. Guernsey, on which island OP compounds are not significantly used, does have BSE. The original investigation was reported at length in The Veterinary Record of 17th December 1988.
The Toxicology Unit of the Medical Research Council conducted a specific experiment to test a basic concept in the theory of Mr. Mark Purdey that an organophosphate could bind to "normal" prion protein, However, they found that the predictions of the theory did not come true. The Government have no plans to make further funds available for research in this area.