Volume 11: Scientists after Southwood
5. Challenges to the Government's approach
Mr Mark Purdey
Introduction
Discussion

Introduction

5.290 Mr Mark Purdey is an organic farmer who for many years was concerned about the use of organophosphorus compounds (OPs) for the treatment of cattle for warble fly infestation. In the early 1980s, prior to the emergence of BSE, Mr Purdey had entered into correspondence with the Animal Health Division of MAFF, highlighting his concerns about the use of OPs and seeking permission to use alternative warblecide compounds (see vol. 12: Livestock Farming, for details of the use of OPs in warble fly eradication programmes). He did not accept the assurances given to him by MAFF and, in 1985, sought a judicial review of the Warble Fly (England and Wales) Order 1982. Following an out-of-court settlement, he was exempted from treating his cattle with OP compounds. ¹

5.291 To the present day Mr Purdey continues to argue the case for an OP-linked aetiology for BSE.

Mr Purdey's letter to Farmers Weekly proposing a link between OPs and BSE

5.292 Following the identification of BSE, Mr Purdey developed a theory that OPs had a possible role in the BSE epidemic. He set out his theory in a letter to the Farmers Weekly in January 1988. He highlighted the similarities between the pathological observations of BSE infected brain tissue and those of the nerve tissue of laboratory animals exposed to known OP neurotoxic agents. He wrote:

My own independent survey on some of the farms inflicted with this crippling neurotoxicity have revealed that warble fly liquids containing 'phosmet' and a brand of feeding stuff (compounded from insecticide-treated raw materials) are the common denominators upon these farms. Either, or both, of these inputs could serve as the delayed neurotoxic culprits to those genetically susceptible Holstein cattle bewitched by BSE. ²

5.293 Mr Purdey told the Inquiry that his independent survey consisted of telephoning five farmers who had cases of BSE on their farms in Devon. ³ He questioned the farmers about their feeding stuff policies and their use of warble fly treatment through the life of the cattle, including the time spent in utero. On the basis of his observations, he suggested a link between BSE and OP compounds.

5.294 The concluding paragraph of Mr Purdey's Farmers Weekly letter read:

Is Farmers Weekly for free thought and development of the farmer or for shielding the embarrassing hiccups boomeranging directly from the compulsory clinical regimes resurrected from the multi-national ministerial alliance?

5.295 Mr Purdey gave us an explanation of this passage:

I suppose I was - even then had a rather cynical view over this. It is the way that I perceived those ministerial bodies. I felt - I suppose I had a bit of a chip on my shoulder, but I think there was some sense to what I was saying that there did seem to be this cohesion between the interests of the multi-nationals selling chemicals and the Ministry of Agriculture, particularly at that time. A lot of the research that the Ministry was doing was always tailored on the side of looking at effects of agrochemicals, rather than looking at the alternative biological means of control. Being an organic farmer, this was obviously causing me a sort of problem. ⁴

5.296 Mr Purdey wrote a further letter to Farmers Weekly that was published on 3 August 1990 under the heading, 'Look for missing BSE link'. He said:

I find it interesting that the 250 or so cattle that have grown up through my dairy unit were consistently fed the brands of cake alleged to contain the BSE agent, yet not one of them has developed BSE symptoms. Perhaps the unique feature of my herd is that I have consistently refused and banned the use of anti-cholinesterase-based insecticides and wormers in my management. ⁵

Suspect BSE case on Mr Purdey's farm

5.297 On 14 July 1991, Mr Purdey wrote to Mr Keith Meldrum (CVO) outlining a suspected case of BSE in one of his cattle. He sought a guarantee that MAFF, once the afflicted cow was handed over for slaughter, would grant him access to the animal so that he could carry out an independent examination of its central nervous tissue. ⁶ He recognised that such work would have to be carried out at a MAFF or other specialist laboratory. He also outlined 'various correlations which suggests why BSE could be a sequel to an acute or chronic neurotoxic exposure some years previous to the surfacing of the outward symptoms.' He reiterated his claim that there were no other cases of BSE on his farm although the cattle had been fed with alleged contaminated feed.

5.298 Mr Meldrum replied to the letter on 25 July 1991 saying that under the terms of the Form A (under the slaughter and compensation scheme) Mr Purdey must surrender the carcass of the animal to MAFF and that they could not grant independent access for examination of central nervous tissue. ⁷

5.299 Towards the end of 1991, Mr Purdey wrote to his local DVO, Mr G W C Wilson, at MAFF's Taunton office. His letter included a suggestion that there was a connection between BSE and warble fly treatment. The letter was received on 22 November 1991. In his reply dated 25 November, Mr Wilson commented:

You also suggest that there is a correlation between BSE and warble fly eradication areas. I enclose extracts from the Chief Veterinary Officer's Annual Reports for 1984-1986, the years in which warble fly infected areas were declared. As you will see these areas are clearly defined and circumscribed. The incidence of BSE, both in location and in the number of cases per 1,000 of the cattle population, show no correlation with the warble fly infected areas.

Circumstantial evidence continues to indicate a food-borne origin ie scrapie-contaminated meat and bonemeal in cattle rations. This would also account for the considerable number of BSE cases born after the final warble fly infected areas in 1986. ⁸

5.300 In March 1992, an article by Mr Purdey entitled, 'Mad cows and warble flies: A link between BSE and organophosphates?' was published in The Ecologist. ⁹ The article stated that scientific establishments were ignoring the importance of genetic and environmental factors that could influence the chances of an animal succumbing to infection by the BSE agent. He presented data that he said demonstrated that, in some cases, there was a correlation between warble-fly eradication zones and incidences of BSE cases.

5.301 In addition, Mr Purdey suggested that TSEs were linked to other degenerative disorders such as Parkinson's and Alzheimer's diseases in the way that they developed. ¹⁰ He referred to a review article published in 1985 by Professor Gajdusek of the National Institute of Neurological Disorders, USA, which discussed the similarities between these diseases. Mr Purdey concluded his article by stating that 'a link between BSE and organophosphate treatments is more than plausible, yet MAFF refuses to carry out the necessary research to prove or disprove the OP theory'.

5.302 Mr Purdey entered into correspondence with Mr Tom King, his constituency MP, informing him of his concerns and theories in order that these matters could be brought to the attention of the Ministry. ¹¹ Mr King subsequently wrote to Mr Gummer on 18 May 1992. In his reply of 8 June, Mr Gummer stated in relation to the suggestion that BSE was attributable to organophosphate compounds that 'on the information currently available to us, it is not possible to draw any conclusions in support of Mr Purdey's argument.' ¹²

Treatment of a BSE suspect with compounds used as antidotes for nerve gas

5.303 On 8 July 1992, Mr Purdey wrote to Mr Meldrum notifying him about a second suspect case of BSE in his herd. He demanded the right to treat the cow with compounds used as antidotes to nerve gas, to test it for OP toxicity, and, in the event of death, to examine the CNS tissue in a certified laboratory. ¹³

5.304 Mr Kevin Taylor briefed Mr Soames on this request in a minute on 13 July 1992. ¹⁴ He said of Mr Purdey that:

Although he claims that MAFF refuses to investigate the 'link' between BSE and OPs the original epidemiological study did in fact consider whether any chemical or medical treatment was the cause of BSE, and found no evidence to support the theory.

The CVO will reply to Mr Purdey. We have no objection to samples being taken from the live cow for analysis, or to delaying slaughter provided that the welfare of the animal is not prejudiced. A veterinary officer will make regular visits to assess clinical progress, as is done for any suspect where slaughter is delayed. If welfare considerations require, the cow will be slaughtered whether Mr Purdey agrees or not. The question of access to tissues post mortem is less easily resolved: Mr Purdey will be asked to provide more detail of what he proposes and where work will be done. The prevention of any risk to human or animal health will be paramount in any decision which is taken.

On past evidence Mr Purdey is likely to seek publicity about this case to further his arguments, and we believe that he has already contacted the Times. The July issue of Dairy Farmer also carried an interview in which he expounded his opinions, although this was written before his second suspect case occurred. Press Office are aware of the situation. ¹⁵

5.305 In a letter to Mr Purdey on 14 July, Mr Meldrum agreed to the tests being carried out and treatment given, on condition that the animal's welfare was not compromised:

. . . I do appreciate that your prime concern is that you are given the opportunity to carry out further investigations on the suspect to confirm your theories on organophosphorous toxicity. I have no hesitation in agreeing to your carrying out further tests on your animal while it is under restriction, with the proviso that it will be subject to regular clinical inspection by a veterinary officer. Our overriding concern is for the welfare of the animal, and if at any time it is deemed to be suffering unnecessarily, it will be slaughtered . . .

With respect to carrying out examinations on CNS tissue after slaughter however, I must ask for further information before agreeing to vary our procedures. Our primary concern at this stage is to investigate whether or not there are lesions in the brain which confirm the clinical diagnosis of BSE, and to conduct those investigations under conditions that do not prejudice animal or public health. We do this in our own laboratories by following strict protocols in controlled conditions, by exposing only those tissues needed for diagnosis, and by incinerating the headless carcass without further dismemberment . . .

I can assure you that we have not closed our eyes to the needs to individual farmers, or to the fact that symptoms characteristic of BSE may be caused by other syndromes. It is in our interest, as well as that of the owner, to permit differential diagnosis or treatment of the suspect while under restriction, subject to welfare considerations . . . None of our investigations, however, link either clinical signs or the development of lesions of BSE with prior treatment with organophosphorous drugs. ¹⁶

5.306 Mr Purdey's treatment of this second BSE suspect was the subject of much press coverage during mid-July 1992. On 13 July, Mr Kevin Taylor minuted those SVS staff likely to come into contact with Mr Purdey, and others in MAFF, stating that:

All involved in this case will be well aware that the situation is being milked for publicity by Mr Purdey, with enthusiastic support from Professor Lacey. As a result all we do is subject to constant scrutiny by those who will not hesitate to use any unwise action or careless comment for their own ends.

It is therefore essential that all staff who visit the farm, or who may be asked to comment, act with the utmost circumspection. No interviews should be given to TV, radio or the press, and requests should be immediately referred to the Press Office in Whitehall. Action on the farm and contacts with Mr Purdey should be restricted to those necessary to observe the development of clinical symptoms in a suspect animal (as on any other farm with a suspect), and to protect the welfare of the cow. This implies more frequent veterinary inspection than is usual, but this is made necessary by Mr Purdey's own demand that the animal be kept alive for treatment. The details and effectiveness of that treatment are a matter for Mr Purdey and his veterinary surgeon, not MAFF. Our concerns are BSE and welfare. ¹⁷

5.307 Mr Purdey told the Inquiry that the DVO at Taunton had agreed to his request to carry out a course of treatment on the suspect BSE cow. Further:

The DVO also said that he had no objection to delaying the service of the Notice of Intended Slaughter to allow treatment to take place, provided that the cow's welfare was not prejudiced. On 16 July I injected 'Damson' with oxime and atropine sulphate, pharmaceuticals carried by troops in the Gulf War as an antidote to nerve gas. Within 90 minutes the cow appeared to have remitted. On Friday 18 July Mr Budge, my vet and Mr Cohen, the MAFF vet, examined 'Damson'. Over the following weekend 'Damson''s condition deteriorated. I asked my vet to continue with the injections. On Monday 19 July Mr Cohen visited my farm and told me that 'Damson' should be put down. Mr Budge later arrived and said that he had to take further advice before reinjecting 'Damson'. On 20 July 'Damson' was down on the ground. I wanted to go to the High Court to force the Ministry to let me continue the treatment. Mr Cohen then paid me a further visit and I had no choice but to consent to 'Damson' being put down on welfare grounds. ¹⁸

5.308 BSE was confirmed in this cow by MAFF on 20 August. ¹⁹ Mr Purdey wrote to the Mr Wilson on 29 September about various aspects of 'Damson's' case. Mr Bradley replied to this letter on 5 November with the aim of following up and clarifying some of the statements Mr Purdey had made:

That your Jersey cow, Damson (RBSE 92/23076) had BSE confirmed is beyond dispute. You say you had assumed the cow had chronic OP-induced spongiform encephalopathy (SE) and this was supported by blood tests and response to 2 PAM and atropine. If you are satisfied and agree the final diagnosis of BSE so be it. However if you are suggesting that the cow had concurrent, chronic OP-induced SE we would like to see the supporting evidence for this conclusion with the agreement of your veterinary surgeon. This would include a clear description of the clinical signs (with dates of examination) the nature, result and interpretation of the blood tests, and when the blood samples were collected in relation to the clinical signs and treatments. ²⁰

5.309 In his evidence to the Inquiry, Mr Purdey said that he supplied Mr Bradley with the appropriate details. ²¹

5.310 In his letter of 5 November 1992, Mr Bradley also referred to Mr Purdey's suggestions that MAFF should initiate some research into BSE. However, he said that Mr Purdey had presented no new evidence that suggested this would be necessary, but should he do so, his proposals could be reconsidered. He added:

However it would be helpful to us in considering any proposals for further research to have a clear statement of the objective or the hypothesis to test. ²²

5.311 When asked about his reaction to this, Mr Purdey said:

I felt sort of that it was putting the onus on me to do the research, which - obviously I am a very small farmer and I have not got much money, so to do the sort of extent of tests that would be necessary to provide some sound scientific evidence that would in my mind spearhead MAFF to take it up was obviously out of my pocket. All I was able to do was to do what I had been trying to do, to test BSE cows on my farm in relation to the healthy cows on my farm. I felt I was in a no-win situation. I was limited in what I could actually do to achieve that requirement that Ray Bradley was putting on me. ²³

Suggestions of maternal transmission

5.312 In April 1993, MAFF were notified by Taunton Animal Health Office that the offspring of a confirmed BSE-affected animal in Mr Purdey's herd, was showing symptoms of the disease. ²⁴ A veterinary officer at MAFF, Mrs Helen Crea, and Animal Health Officer, Mr Keith Slater, examined the animal. They found that whilst it was in poor condition, the symptoms were only suggestive of BSE. A Form A notice was issued for the animal on 22 April, and its movement restricted accordingly. Mr Purdey claimed that this was the first example of maternal transmission and made this point to the Independent. ²⁵ Subsequent inspections of this animal by MAFF officials on 10 May resulted in the lifting of the restriction since symptoms appeared to have subsided. ²⁶ Mr Purdey wrote to Mr Prettejohn, his local Divisional Veterinary Officer, stating that he was unhappy with this decision and he maintained his conclusion that the cow had been affected in-utero. ²⁷ The cow however recovered and continued milking on the farm. ²⁸

Tom King writes to MAFF Ministers about Mr Purdey's views

5.313 On 5 April 1993, Mr Tom King sent to Mr Gummer a letter that he had received from Mr Purdey. Mr Purdey's letter contained details of his theory that OPs caused BSE, and suggestions of a link between CJD and the use of serotonin agonist drugs for the treatment of hypertension. He had also enclosed a letter from Professor Satoshi Ishikawa of Kitasato University, who considered that Mr Purdey's description 'about Mad cows to organophosphates compounds and warble fly is exactly true' and expressed interest in the similarity between the histopathology of BSE and chronic OP poisoning. ²⁹

5.314 Mr Gummer replied to Mr King on 16 April, saying that detailed studies of cattle with BSE had 'not shown any connection between the use of such chemicals, either in a primary or contributory role'. He also remarked, in relation to CJD, that 'the Department of Health are not aware of any links between drugs used in the treatment of hypertension and the subsequent development of CJD-like illnesses'. ³⁰

5.315 In relation to Professor Ishikawa's remarks, Mr Gummer commented:

Whilst it is true that there are superficial similarities in the histopathology, as observed under light microscopy, of the lesions in brain tissue of animals affected by organophosphate toxicity and spongiform encephalopathy disease, there are clear and important differences in the ways in which the nerve cells are affected. These differences are agreed and have been extensively studied and documented by neuropathologists. ³¹

5.316 Mr Gummer concluded his letter by commenting that much research was underway to investigate the many aspects of this group of diseases. He enclosed an interim report describing research that was underway which he thought Mr Purdey might find interesting.

5.317 In evidence to the Inquiry, Mr Purdey described his reaction to the letter:

Well, when I read the list of research that was being carried out, I could not see anything at all that was relevant to my hypothesis, nothing at all. It seemed to be all tailored to investigate the official scrapie leap theory as the cause, and some work on the prion protein, but that obviously involved - you know, they were saying that the abnormal prion from sheep had jumped into cows and mutated, or whatever it was. ³²

5.318 On 17 May, Mr King sent a further letter that he had received from Mr Purdey, to Mr Gummer. Mr Purdey said that he did not think that the studies initiated by MAFF at the outset of investigating BSE were sufficient to determine whether chronic or delayed OP toxicity played a role in either triggering or exacerbating the disease. He also said that Mr Wilesmith's report that no correlation between BSE and acute exposures to OPs could be identified, did not rule out what he considered to be the most likely cause, namely chronic OP poisoning. Further he said:

From international research into chronic OP toxicity in humanity (Professor Ishikawa is a renowned expert in this field), there are more than (as the Department terms it) just "superficial similarities" in the lesions and pathogenesis of BSE. ³³

5.319 On 16 June Mrs Gillian Shephard, the new Minister of Agriculture, replied to Mr King. She commented that:

Although OPs can react with a variety of biological substances, I am advised that OP poisoning differs so greatly from BSE that the link is most unlikely. Clinically, OP poisoning is so dissimilar to BSE that the two are unlikely to be confused, and there is no evidence to link any immunotoxic or mutagenic effects of OPs with BSE. ³⁴

5.320 Mr Purdey said in evidence that he did not agree with Mrs Shephard's comments. He continued:

. . . she had not differentiated between acute OP poisoning and chronic OP poisoning, which show markedly different symptoms and pathology. It was a mainstay of my theory that this was a chronic problem, if you like, a high dose chronic problem. And this had been sort of ignored. This vague generalisation was in a sense a misrepresentation of what I was actually saying. Also, I can never recall having linked the immunotoxic effects of acute high doses of organophosphates to BSE because work has shown that in mice the immune system is actually required for the disease process to ensue, because when they have engineered mice with an immune knock-out, they cannot develop the disease. ³⁵

Article in the Sunday Telegraph about OPs

5.321 On 22 August 1993 an article by Mr Greg Neale, the Environment Correspondent, was published in the Sunday Telegraph. ³⁶ The article stated that:

The Government is reviewing the safety of chemical veterinary products, including some used in the home, amid fears that they could be linked to illness in farmers using sheep dip, or even bovine spongiform encephalopathy - BSE or 'mad cow' disease.

Gillian Shephard, the Agriculture Minister, has ordered the review of all veterinary products containing chemical organophosphates (OPs) including flea collars used on cats and dogs as well as on cattle and sheep.

5.322 The article continued:

An Agriculture Ministry spokesman said yesterday that the review did not mean there were grounds for linking 'mad cow' disease with OPs, as has been suggested by some researchers.

5.323 Mr Purdey commented in his evidence that:

I did not know anything about it at all. Certainly in relation to BSE, I was not aware that there was any proposed review into looking at the chemicals as a possible link to BSE or CJD. ³⁷

Further correspondence with Mrs Shephard

5.324 On 1 Sept 1993 Mr King sent a letter to Mrs Shephard, enclosing a letter from Mr Purdey requesting a meeting with her to discuss his theories. ³⁸ Mrs Shephard replied to Mr King on 17 Sept 1993 saying that:

In view of the highly technical nature of the issues involved, I suggest that Mr Purdey should meet my scientific advisors so that he can fully explain his views and they, in turn, can raise any points which they may have for Mr Purdey to consider. ³⁹

5.325 Mrs Shephard also proposed that Mr Purdey:

. . . supply a pre-publication copy of his paper for distribution to the appropriate experts on a strictly 'In Confidence' basis (as is usual with such papers), then this would also facilitate the understanding of his hypothesis.

She suggested that he write to Mr Adrian Dixon of the Animal Health (Disease Control) Division to make arrangements for the meeting.

5.326 On 30 September 1993, Mr Purdey wrote to Mr Dixon as proposed noting that he had asked Mr King to forward his pre-publication paper. He also set out a suggested format for the proposed meeting. ⁴⁰

5.327 In October 1993, Mr Purdey sent his pre-publication paper to Mr King, who in turn forwarded the paper to Mrs Shephard. ⁴¹ In her letter to Mr King of 14 October, Mrs Shephard confirmed that the paper had been sent to the Veterinary Medicines Directorate and that 'his [Purdey's] points will be noted and borne in mind during the consideration of the OP sheep dip issue by the Veterinary Products Committee'. ⁴²

5.328 At around this time, MAFF complained to the Press Complaints Commission about a Sunday Telegraph article which, amongst other things, had advocated 'a theory that the symptoms of BSE result from organo-phosphorus poisoning rather than from a transmissible disease agent'. ⁴³ Mr Purdey told us:

The Ministry had complained to the Press Complaints Commission about articles by Christopher Booker in the Sunday Telegraph which had supported my theories on BSE and which had criticised MAFF staff. The Ministry included an evaluation of my theories and they included an extract of the paper, which I had sent to the Minister. Mrs Shephard wrote to Mr King MP about this on 13 December 1993 and in the circumstances said that they did not regard what they had done as a breach of confidence. I did not accept this understanding of the situation. ⁴⁴

5.329 On 13 December, Mrs Shephard wrote to Mr King apologising for any misunderstanding about the handling of Mr Purdey's paper. She said, however, that she did not construe the use of the material as a breach of confidence. She said that a meeting would take place on 17 January 1994 to enable Mr Purdey to discuss his paper. She noted that '[we] have gone to a great deal of trouble to assemble a team of experts in the wide range of fields covered by Mr Purdey's paper, including the flying in of an expert from the NPU in Scotland'. ⁴⁵

Meeting between Mr Purdey and MAFF

5.330 The meeting arranged by Mrs Shephard took place at the CVL on 17 January 1994. ⁴⁶ It was chaired by Mr Eddy and attended by Mr Purdey, his brother Mr Nigel Purdey, Mr Wilesmith, Mr Bradley, Mr Jackman, Mr Livesey, Mr Austin, Dr Hope from the NPU, Mr Salahud Din, Dr Marrs from DH and Dr Woodward. Mr Purdey explained his theory that OPs had caused BSE by mutating the PrP gene or by action at the level of transcription or translation, and that the disease had become an epidemic because of recycling animal waste into cattle feed. Mr Wilesmith said that he had considered the use of OPs as a possible cause of BSE in his early epidemiological investigation, but had ultimately rejected it since no correlation between OP usage and BSE incidence was found. A lengthy discussion followed where Mr Purdey's theories were considered individually in terms of existing scientific evidence. Mr Purdey said that his objective had been to stimulate MAFF interest in his theory and consider the possibility of research into it. He did not suggest avenues of further research. It was agreed to look further into Mr Purdey's theories, especially in relation to pesticide-contaminated citrus pulp and cereal by-products, though specific research was ruled out.

5.331 A minute from Mr Eddy to Ms Mannix in the Press Office on 17 January 1994, described the meeting as amicable and as one which had resulted in agreement between MAFF and Mr Purdey on three matters, namely:

that the risk to humans is remote; that the present regulations are adequate to control the disease in cattle and that the number of cases is declining; on the importance of recycled animal protein in the spread of disease.' ⁴⁷

5.332 In evidence to the Inquiry, Mr Purdey said in relation to the third point: 'I did agree I felt it had a role, but I would not say I felt it was quite as important as the Ministry considered it.' ⁴⁸

5.333 In June 1994 Mr Purdey published in the British Journal of Nutritional Medicine his paper entitled, 'Are Organophosphate Pesticides involved in the Causation of Bovine Spongiform Encephalopathy (BSE)? Hypothesis Based upon a Literature Review and Limited Trials on BSE Cattle'. ⁴⁹ The paper described the various elements of the theory of OP-induced disruption of prion protein synthesis as a cause of BSE, the different sources of OPs and the role of magnesium and calcium. Serotonergic deficits, genetic susceptibility, and possible auto-immune responses were also described. Mr Purdey concluded that the best way of preventing neurodegenerative disease would be by rigorous screening of chemicals before they are approved.

5.334 On 2 June 1994, Mr Eddy wrote to Mr Purdey, following up various issues raised at the January meeting along with further points raised by Mr Purdey in subsequent letters to MAFF. ⁵⁰ Mr Eddy said:

The idea that you mentioned in your letters of in vitro experiments is certainly an interesting one, but as you will no doubt recall at the meeting, there is no obvious model system which could be used at the present time to do these experiments, nor as I understand it, do you have any unique or particular chemical from the OP family which you hypothesise as the responsible agent which could be tested. Screening all OP agents, and all possible contaminants, and synergistic effects of combinations of chemicals would of course lead to an impossibly complicated set of experiments.

5.335 Mr Eddy went on to address specific points which he had promised to look at during the January meeting. Mr Purdey had been concerned about OP build up in citrus pulp, a major component of animal feed. Mr Eddy said that if the OP content of citrus pulp was responsible for the initiation of BSE, it was unlikely that BSE occurred only in the UK, since citrus pulp is an imported feedstuff. Mr Purdey had also expressed concern about pesticides binding to grain. Mr Eddy said that some residues bound to grain and some of these were toxicologically active if digested and absorbed. He went on to say:

'Legislation is based on concentrations of free (unbound) residues. Research carried out by the Central Science Laboratory of MAFF has shown OP residues in grain could cause underestimation of total OP concentration by up to 1.5ppm. That is an acceptable error because the UK maximum residue levels (MRLs) for the OP commonly used in grain are 10 ppm except for malathion, for which the MRL is 8ppm.'

5.336 Mr Eddy concluded that:

I have to say that we remain of the view that the probability of OPs having caused BSE is very low, because the toxicology of OPs has been very extensively studied and their usage is worldwide. The epidemiological and pathological findings simply do not support this hypothesis.

5.337 Following this letter, Mr Purdey wrote to Mr William Waldegrave, the new Minister of Agriculture, on 8 July expressing his disappointment at the response from MAFF and his suspicion that his requests for further research were being deliberately misunderstood. ⁵¹ He then went on to outline his theories.

5.338 Replying for the Minister, Mr Adrian Dixon assured Mr Purdey that his work was not being dismissed outright and that significant consideration had been given to it. ⁵² The main scientific points of Mr Purdey's letter were considered and answered. Mr Purdey was reminded that the epidemiological evidence still supported the food-borne hypothesis for the origin of infection and was not discredited by the incidence of diseased animals born after the feed ban. Mr Purdey's theory with respect to OP use could not, however, explain the epidemiological observations.

5.339 Additionally, Mr Dixon expressed confusion as to an apparent change in Mr Purdey's hypothesis, which suggested that disease was induced by a chemical-only mechanism as opposed to earlier assertions that it was caused by the interaction of OPs with the scrapie-like agent. On the matter of similarities between chronic OP poisoning and BSE, Mr Dixon relayed his advice that major differences existed between the clinical and histopathological aspects of the two conditions. In reply to Mr Purdey's request for PrPc, he was told PrP^BSE was available for research purposes and was advised that, should he wish to use this reagent, he should submit a written research proposal to the Ministry.

5.340 Mr Purdey wrote to MAFF again on 15 and 27 October 1994. Mr Dixon replied on 10 November 1994 explaining again that Mr Purdey's theories could not adequately explain the occurrence of BSE. Mr Purdey was advised to apply for funding by contacting Dr MacOwan. He was also told that his research proposals stood a better chance of being viewed favourably if he would collaborate with a scientific body of reputable standing. ⁵³

Correspondence with Dr Stephen Whatley

5.341 During 1995, Mr Purdey contacted Dr Stephen Whatley, a researcher at the Department of Neuroscience, Institute of Psychiatry in London. ⁵⁴ Dr Whatley told us in oral evidence that Mr Purdey had written to him asking him if he was interested in testing Mr Purdey's theories. This appeared to be as a result of MAFF suggesting that he ought to ally himself with somebody who was more experienced in the field of research. Dr Whatley looked at Mr Purdey's paper and found it very difficult to understand, but felt that there was perhaps 'perhaps a core there that required some explanation'. The paper was later published in 1996. ⁵⁵

5.342 Dr Whatley recalled that in the course of correspondence with Mr Purdey, he suggested various avenues for him as to how the theory could be tested. Mr Purdey eventually decided that it might be possible to do some research in the laboratory. When Mr Whatley explained how things worked in a scientific laboratory, he thought that Mr Purdey had probably been dissuaded, and because of his inexperience, decided to try to raise some money to fund research instead. ⁵⁶

MRC experiments into the link between OPs and BSE

5.343 On 28 April 1995, an article appeared in Farmers Weekly stating that the MRC would be involved in preliminary trials to test the link between OPs and BSE. ⁵⁷ The article stated that:

The trial will determine whether OPs can bind to normal prion protein and then convert it into the 'mutant version'. If this is the case then it will also test whether the deformed protein is itself the BSE agent and if it is infectious.

5.344 Initially, it was proposed that the work be funded by Channel 4, with the intention that the results could be used in a programme about Mr Purdey as a lone voice against the scientific establishment. However, in contrast to the claims made by Farmers Weekly, the experiments would only test whether OPs bound directly to the prion protein. ⁵⁸

5.345 On 12 May 1995 Dr Ray of the MRC Toxicology Unit wrote to Mr Nigel Gregory of Lauderdale Productions, confirming that the experiment was still valid as planned. ⁵⁹ He added that the statement made in Farmer's Weekly that Mr Purdey had 'strong support from the establishment' was 'rather overstated'. He also said that he had:

. . . been in touch with MAFF to clarify that I am only involved in testing those first steps of his hypothesis which relate to the organophosphate-protein interaction, and not with the question of infectivity.

5.346 The report of the experiment was published on 28 July 1995. ⁶⁰ It concluded that the experiment:

. . . provides no evidence that any part of the protein would represent a particular target for organophosphorous compounds in general.

5.347 Mr Purdey disputed these results. In a letter to Mr Tom King, he voiced his concerns and requested that MAFF should appraise the MRC results and continue with further research. ⁶¹ Mr Purdey also suggested that MAFF was changing its own theories on BSE, by suggesting that very small oral doses of BSE were rendering cattle susceptible to infection. He proposed that this undermined the position of MAFF with respect to foreign cattle, which during the 1980s had been fed UK derived feed and had not shown signs of BSE. On 12 September 1995 Mr King wrote to Mr Douglas Hogg, who had succeeded Mr Waldegrave as Minister of Agriculture, Fisheries and Food, relaying Mr Purdey's concerns. ⁶²

5.348 On 17 October Mr Hogg replied to Mr King expressing surprise that Mr Purdey should need MAFF to interpret the results of the experiment that he had designed to test his theories. ⁶³ He also suggested that since MAFF did not subscribe to the OP theory, there was no reason to carry out further experiments to substantiate the MRC findings. Mr Hogg also rejected claims that MAFF had altered its theory on the cause of BSE.

Channel Four programme on BSE and Mr Purdey's theories

5.349 On 26 July 1995, Mr Hayward sent a minute to Mrs Browning making her aware of the forthcoming Channel Four programme which would discuss Mr Purdey's theories on the cause of BSE. ⁶⁴ It was noted that the programme would like to interview Mr Wilesmith. It was agreed that this would be agreeable as long as certain conditions were met, such as provision of a set of pre-interview questions.

5.350 On 25 September 1995, a further minute from Dr Render was sent to all interested parties, including the Minister and the Minister of State. ⁶⁵ It described the background to the story and noted that:

It is unlikely that the programme will raise concerns about a link between BSE and risks to human health. Mr Purdey has previously confirmed to officials in MAFF that he does not feel that our measures to protect human health need strengthening.

5.351 The Channel 4 programme ('Frontline') was shown on 27 September 1995. In the programme, Mr Purdey asserted that the MRC results did in fact show the modification of PrP by OPs. Reviews of the programme appeared in The Times and the Daily Mail. ⁶⁶ Following the broadcast, Dr Ray from the MRC was interviewed on 'Farming Today'. ⁶⁷ He expressed the opinion that the programme gave a distorted view of OPs, incorrectly linking the toxicity of OPs with long-term disease shown in only a few people. Dr Ray explained the experiment to us in the following terms:

We looked at the prion protein in two different forms, one more soluble than the other, and we made a comparison between that and acetylcholinesterase. Now acetylcholinesterase is the known target for acute toxicity. What we wanted to do was to make a relative comparison between the susceptibility of the prion protein and the acetylcholinesterase. Because it is possible to wind up concentration of the toxic agent so high that it becomes irrelevant to any kind of human or animal toxicology, it is best to have an internal reference. We used, therefore, acetylcholinesterase as an internal reference. If you look at the numbers, you can see that with acetylcholinesterase, there was a concentration of the protein-related increase in radio-labelling which went up to about 4,000 or 5,000 in one case, or about 8,000 counts in the other case.

MR WALKER: That other case is marked 'A' and 'B'?

DR RAY: Acetylcholinesterase A and acetylcholinesterase B. When you look at the case of the prion protein, you will see there is not this large increase. There appears to be a very small, possibly suggestive, possibly significant, possibly not increase at the very highest concentration, but at most this is about 1,000 times smaller than the increase in counts with the acetylcholinesterase. Therefore I concluded that there was no significant interaction with the prion protein. ⁶⁸

Further correspondence with MAFF

5.352 On 1 January 1996, Mr Purdey wrote to Mrs Angela Browning, the Parliamentary Secretary at MAFF. ⁶⁹ He made an accusation that MAFF deliberately misrepresented his theories to others. In addition to restating his central theories, he criticised the MRC experiments, first for not using Phosmet and second on the basis that the experiments that were carried out would not address the mechanism by which disruption of the tertiary structure could affect PrP.

5.353 Mrs Browning replied on 1 February 1996. ⁷⁰ The letter reaffirmed the previous position of MAFF and reasserted the advice received from SEAC. The letter also discussed the research carried out by the MRC in collaboration with Mr Purdey, stating that 'it is not the case, contrary to what you allege, that the Government "hijacked" this research'.

Discussion

5.354 Mr Purdey believed that OPs could cause delayed neuro-toxic effects, and based his evidence of a link between OPs and BSE on the correlation between warble-fly eradication zones and the incidence of BSE. Later, he proposed that the OP-induced toxic effect led to the conversion of PrP^c to the disease-producing PrP^Sc. We are not in this volume concerned to explore the technical aspects of Mr Purdey's theories about the connection between OPs and BSE. These have evolved over time, and are considered in vol. 2: Science. Here we are concerned with suggestions made by Mr Purdey and many of his considerable following to the effect that MAFF were blinkered in that they were not prepared to consider any possible cause of BSE other than their own theory that it resulted from contaminated feed.

5.355 Mr Purdey wrote to various MAFF officials and to his MP, Mr Tom King, in April 1993 about his theory that OPs caused BSE. He was concerned that MAFF were not responding to his ideas by initiating appropriate research, and wrote to Mr William Waldegrave in July 1994 indicating his disappointment.

5.356 In April 1995, the MRC Toxicology Unit agreed to undertake an experiment to determine if OPs could bind to prion protein and convert it to the disease-producing isoform, PrP^Sc. By July 1995, the result of this experiment was known and this indicated that OPs did not convert normal prion protein into PrP^Sc.

5.357 No further experiments were made to test the OP hypothesis until after March 1996 when Dr Stephen Whatley tested the effect of OPs on a neuroblastoma cell line. The only observed effect was an increase in the expression of normal PrP. If such occurred in vivo in the brain it was theoretically possible that OPs could be a factor in susceptibility to the BSE agent. This type of effect could be tested by experiments in mice to determine if treatment with OPs reduced the incubation period following intracerebral inoculation with BSE.

5.358 Mr Purdey is an unusual farmer. Although not a scientist, he has mastered much of the complex science relating to TSEs. His general concern about the use of OPs as a systemic treatment of cattle is not irrational. Nor are his theories of the link between this treatment and BSE.

5.359 MAFF did not reject these theories out of hand, but considered that the epidemiology was not consistent with the observed cases of BSE being induced by treatment with OPs. Mr Purdey came to accept that feed was the significant factor in the recycling of BSE, but persisted in his view that OPs could have been responsible for the original outbreak. More recently, he has suggested that the effect of OPs could increase the susceptibility of cattle to contracting BSE. Dr Whatley's limited experiment lends a modicum of support to this possibility.

5.360 We would commend Mr Purdey for the tenacity with which he has pursued his theories in the public interest. We understand that this has involved him and his family in financial sacrifice. We have considered the manner in which he, and his theories, were treated by Government scientists and have concluded that they received fair consideration. At times his persistence irritated MAFF officials who believed that he was barking up a number of wrong trees. To an extent they were correct, but the door is not yet closed on the possibility that OPs played a role in rendering cattle susceptible to BSE infectivity.