The BSE Inquiry /
Statement No 23A (supplementary)
Mr Mark Purdey Issued 07/06/1999
(not scheduled to give oral evidence)
THE BSE INQUIRY
SUPPLEMENTARY STATEMENT BY MARK PURDEY
GENERAL COMMENTS
- My concerns with Phase 1 of the BSE Inquiry
surround what I believe to be the inaccuracies and misleading statements made in several
of the written documents and hearings involving the various critics of my
Organo-phosphate/BSE thesis.
- I take issue with the core of the arguments
propounded during the hearings of November 5 1998 (Day 5). This session hosted the various
representatives/advisors of the organisations opposed to my thesis – Mr Roger Cook
(NOAH), Dr Tony Andrews (formerly at the Veterinary Department of the MLC), Dr Tim Marrs
(senior medical officer, Joint Food Standards and Safety Group) and Mr John Tasker
(Grampian Pharmaceuticals).
- Understandably, these people all share an interest
in defending their past decision making skills and/or their commercial products against
the potential threat that my thesis on the UK’s overuse of the systemic OP phosmet
presents to their professional reputations and/or financial interests.
- All of these individuals had generally utilised
the same lines of argument to counter my thesis. Consequently, in my view, their various
statements are all flawed in the same way, so I can largely address all of their
statements via a single attack.
- I refer to what I consider to be the most obvious
flaws; in paragraph 6 to 16 below.
Equal Amounts of the warblecide,
Phosmet were applied each year in Eire, UK and France (paragraph 28 Mr Cook’s statement
no. WS 270).
- This was an inaccurate claim for many reasons. It
is particularly ironic in the light of Dr Andrew’s statement that the UK’s sales
figures for phosmet usage had been lost! (Dr Andrews supplementary statement no. WS 269A
para 45). How could they arrive at such an assumption if the UK’s sales figures were
genuinely lost?
- Furthermore the French body INRA have confirmed to
me in writing that only 150,000 doses of phosmet were used per year in France during the
mid 1980s only. (I hold a 1996 fax from Mr Roger Cook of NOAH to the French ‘Ecology
Party’ which demonstrates that NOAH were aware of this French sales data).
- In Eire, O’Keefe et al state that phosmet was
first taken up at the end of their warble campaign in 1978 where it was only used once a
year in certain regions. We are told that the Dovea region only ever used phosmet (Dr
Andrews’ statement WS 269A paragraph 49), but if Dovea had conformed to Eire’s
eradication campaign that was initiated in the 1960s, , then other types of OP warblecide
must have been used there prior to the introduction of phosmet in 1978.
- It should also be pointed out that Mr Tasker’s
Statement [WS273] does not specify that they are relating to phosmet as an individual
compound when it cites Eire’s warblecide usage figures for 1978-1980 (Annex 1 paragraph
7 of WS 273). This should be clarified, because these same figures, also cited in a letter
I hold from the NFU chairman, Ben Gill, would appear to relate to all types of OP
warblecide such as fenthion and famphur which were more widely used in Eire than phosmet
at that time.
- However in the UK, phosmet use steadily increased
from 1975 until 1985, when it became the only type of systemic OP left on the market –
at a time when it was compulsory to apply warblecide twice a year in the warble infested
zones at 20mg/kg dose employing a 20% concentration fluid.
Warble Fly Treatment was never compulsory (Mr Cook’s statement paragraph 39 WS 270)
- It was compulsory from 1982 onwards; whereby
treatment was required 2 times a year in various sized zones all over the country. One
must question why I needed to take out a High Court action to debar the compulsory
treatment of my cows in 1984 if it wasn’t compulsory?(see my Inquiry Statement WS 23
paragraphs 3 and 4) Mr Cook’s statement is contradicted for example by Dr Andrews (WS
269A paragraph 43) where he refers to "the notifiable period of the disease when Mr
Purdey did not wish to treat his cattle."
Compulsory Warble Fly Zones only
existed in tiny pockets in SW England and Wales in the 1980s (Mr Cook’s statement
paragraph 47 WS 270)
- This is painting a totally inaccurate picture. As
depicted in MAFF’s Annual Animal Health Reports for this period, warble fly zones were
declared all over the UK. Although it is true that the majority of warble outbreaks did
occur in the South, this generally reflects the geographical distribution of BSE
incidence.
The Warble dose rate for Phosmet
was set at the same 20mg/kg dose rate in all of the nine countries where Phosmet was
licensed and marketed (Mr Cook’s statement paragraph 27 WS 270)
- This is a true statement in itself but is
misleading. For in real terms, it presents a flawed and irrelevant argument against my
theory because the UK, Ireland and France (NB BSE endemic countries) were the only
countries to have licensed phosmet and actually applied it at its warble fly dose rate.
- Warble flies have simply never existed in
countries such as Australia and New Zealand where phosmet has only been licensed for use
at the lower10mg/kg lice dose rate. This is analogous to purchasing an American made
Combine Harvester in the UK, where its universal instruction manual would naturally give
you the different settings for all types of combinable crops such as soya beans, even
although soya is not actually grown in this country.
- I believe that my thesis on the use of phosmet and
its unique practice of ‘overdosing’ in the UK still holds. Phosmet is unique amongst
systemic OPs in that it contains a phythalimido moiety which belongs to the family of
chemicals to which thalidomide belongs. It was the unique compulsory twice annual usage of
a systemic pour-on formulation of the OP phosmet in the UK – used at a 20mg/kg
bodyweight dose employing a 20% concentrated warblecide – which initiated the UK’s BSE
epidemic.
- Once solvent extraction ceased in the rendering
process in the early 1980s, the tallow fraction of MBM became responsible for the spread
and bioacumulation of both phosmet and its ‘prion’ products up the farm animal
foodchain.
THE STATEMENT OF MR COOK, DIRECTOR
OF NOAH (NATIONAL OFFICE OF ANIMAL HEALTH) A DETAILED RESPONSE TO NOAH’S STATEMENT;
‘THE ALLEGED LINK BETWEEN OPS AND BSE’ (WS 270)
Background (paragraphs 12 to 15
of Mr Cook’s statement)
- I made it quite clear in the mid 1980s that my
reasons for challenging MAFF’s Warble Order stemmed from my fears surrounding the
delayed neuro-psychiatric and mutagenic aberrations resulting from exposure to
‘systemic’ types of ‘pour-on’ OP insecticides. I pointed this out directly to
Roger Cook of NOAH via a public letter to Farmers Weekly of 10/5/1985. Had I not had
grounds for extreme concern, then I obviously would not have bothered to go to the extent
of mounting a High Court Action, etc, which naturally incurred an intense amount of stress
and personal loss.
- I was concerned about;
- the risks to the consumer of the meat and milk
from OP treated cows;
- the risks to the farmer applicator who applied the
insecticides; and
- the long term, delayed risks posed to the central
nervous system of the OP treated cattle, mediated via a neurotoxic or mutagenic effect of
the chemical itself.
- I expressed my fears that an epidemic of bovine
neurodegenerative disease would ensue in cattle, and I was quoted saying this in my
newspaper articles, news media at that time, plus I expressed this fear in letters to
numerous MPs, MAFF officials. The fact that many of the MAFF/HSE letters (held by the
Inquiry) in response to those of mine all state that my claims, on the long term, delayed
neurological/psychiatric effects of OPs were at variance with expert medical opinion,
clearly demonstrated that I must have been raising this issue in the first instance.
However, there were numerous papers published in journals at that time which clearly
depicted that my ‘views’ were not actually at variance with informed expert opinion
and that these types of neurotoxic sequelae to certain types of OP intoxication were
indeed widely recognised.
- The moment BSE became officially recognised I
wrote to the Farmers Weekly and pointed out that this disease was the direct result of the
warble fly campaign (see paragraph 6 of my Inquiry statement WS 23)
- Both NOAH, Dr Andrews, the Government and the
majority of my critics have repeatedly alleged that I "keep on changing my theory
over the years… each time it is rejected, etc", but in reality it is only they who
are changing my theory.
- The fact that I have not changed the cornerstones
of my theory is clearly witnessed by my 1987 letter to the Farmers Weekly where I refer to
a small survey that I had carried out on farms affected with BSE and how that had
indicated that it was the ‘phosmet’ brand of warblecide that had (theoretically at
that time) caused a delayed neurodegenerative condition in cattle manifesting as
‘BSE’. In this letter I also inferred that these OPs would be concentrating in the
meat and bone derived from those treated cattle, and therefore getting back into cattle
via the feed route too. Essentially, I am still saying exactly this today, but one has to
exercise an open minded and lateral approach when formulating and developing any
scientific hypothesis. A rigid dogmatic approach is no good for anyone. So it is
inevitable that ‘extensions’, ‘updates’ and greater detail will become
incorporated into the evolution of any hypothesis that it gaining momentum whenever fresh
pieces of evidence come to light.
- The Inquiry Secretariat, told me that "many
people are saying that I change my theory", pointing specifically to one
‘alleged’ change where I am hypothesising that OPs are interacting with the glycolipid
anchor. I have consistently been focusing on PrP’s glycolipid anchor as a potential OP
interaction site as highlighted in all of my papers since 1993. I referred to this
glycolipid site as ‘the surface of PrPc’ in my 1994 J. Nutri. Med. Article
[J/NUM/4/43], then again (more up front) as ‘the all important serine 231 site on PrP’
on p436-437 of my 1996 Med. Hypotheses article [J/MH/46/429], then finally as ‘the
glycolipid anchor’ in my Med. Hypotheses 1998 article [J/MH/50/91]. As the Institute of
Psychiatry tissue culture study has demonstrated a protracted retention of PrP on the
membrane surface in phosmet treated cells, then one explanation for this abnormality could
infer that a conformational change had indeed occurred at this precise serine 231 site –
this could cause an impairment of cleavage by phospholipase C at this site, thus delaying
the release of PrP from the membrane which is one of the a characteristic features of TSE
pathogenesis.
- The experiments of Shaw I [J/NST/1993/50] et al
and Ray D [WS68] et al both involved the exposure of recombinant PrP to OPs. Because
Recombinant PrP lacks the PI anchor conjugate then these experiments did not cover the
main candidate site of OP interaction according to my theory, let alone cover other
candidate mechanisms that I have proposed such as a phosmet invoked free radical
interaction with the copper domain on prion protein, or with side chains etc, etc.
- I have consistently proposed that it is an ‘in
utero’ intoxication which heralds the ‘initiating’ event of BSE pathogenesis (for
phosmet concentrates in the fetus), plus the fact that I have also proposed that phosmet
needs to bio-concentrate up through the bovine foodchain (via the tallow fraction of MBM)
as a contributory means towards achieving the endpoint whereby the ‘threshold level of
toxic tolerance’ to phosmet is exceeded, and then BSE erupts. I contend that the OP-BSE
theory does indeed cater for the delayed lag that exists between the time when phosmet use
really took off and when the first cases of BSE erupted, etc. So the timing of systemic
phosmet use in the UK in relation to my proposed mechanisms of phosmet bioaccumulation
(via tallow, etc) does indeed correlate with the spatio-temporal epidemiological facts
surrounding BSE.
- From the onset, my work has clearly striven to
pinpoint some ‘unique’ facet of OP usage in the UK in order to address the virtual
exclusivity of the BSE outbreak to the UK. This is why I focused on ‘phosmet’ as the
most likely hypothetical candidate for BSE initiation, simply because the UK was the only
country in the world to compel its 2 times annual usage as a ‘systemic, pour-on’
20mg/kg dose of a 20% concentrated formulation within certain zones of the UK.
MY DETAILED RESPONSE TO THE NOAH
REPORT
- NOAH quite correctly set the scene by depicting
the distribution of BSE cases internationally (paragraph 16 of Mr Cook’s statement WS
270).
- But it should be born in mind that since Ireland,
Switzerland, France and Portugal adopted a more ‘over the top’ policy of BSE control
than applied in the UK – eg. slaughter of the entire herd following the emergence of the
first case of BSE – then this would have masked a considerable number of further cases
of BSE that would have emerged in these countries had entire herds not been slaughtered
following diagnosis of their first BSE case.
- It should also be noted that it is only the UK,
Ireland, Switzerland, France, Portugal and Holland that have hosted endemic BSE in their
native cattle – so the various criteria of the particular pesticide / feed policies
relating to those countries must be able to satisfy the prerequisites of the OP
hypothesis, whereas the respective policies of the remaining endemic BSE-free countries
must fail to match the OP Hypothesis.
- However the remaining countries on the BSE list
involved BSE cattle that had been imported in from the UK whilst incubating the disease.
NOAH go on to address the widespread use of OPs around the world-particularly in the
arable sector (paragraph 20 of statement WS 270). I regard this as irrelevant to my theory
that focusses on the use of ‘systemically’ acting phosmet warblecides on farm animals.
- However, NOAH’s table 2 (page 3 of WS 270)
provides an interesting insight into the relatively excessive use of OPs in 1987 on food
animals in Western Europe – the area which NOAH correctly cites as the global region
that suffers an exclusive BSE problem. Of particular interest is the near 20 fold less
usage of OP by monetary value in BSE-free North America as compared to Western Europe; NB,
Both USA and Europe share a similar monetary value for OPs.
- NOAH then state that in their experience there is
no single use of OPs, or specific OPs, which is unique to the UK(paragraph 21 of WS 270).
I agree with this, but my theory focuses on the overall annual dosage rate and frequency
of application of a specific type of ‘systemic’ pour-on OP, phosmet, whose usage,
albeit less intensive, also had to be linked to the other countries suffering a much
smaller incidence of endemic BSE.
- The dose rate and frequency of dosing of any
chemical is very important when gauging the specific toxicological effect of a given
chemical. Eminent neurologist Peter Spencer states in his paper ‘recognising neurotoxic
disease’ that multiple types of syndrome can develop from the same toxic substance. He
states that "exposure to different levels of the same substance may result in a
dramatically different clinical picture. This fundamental principle of toxicology is
frequently overlooked in the haste to simplify a puzzling clinical picture." This is
why, according to my theory, BSE will only erupt in a country once a certain profile of
repeated, high dose usage of phosmet and its residual contaminant in tallow is adhered to.
- NOAH then quite correctly state that animal
by-products have been fed for over a century (paragraph 24 of WS 270), but ignore the fact
that tallow has been extracted from this feed for over 60 years – via the solvent
extraction method – right up until the early 1980s when solvent extraction was dropped
once the rendering process was revolutionised, adopting the ‘continuous flow system’
(See Wilesmith’s papers).
- NOAH further make generalised statements that OPs
have been in use on farm animals internationally since the 1950s (paragraph 24 of WS 270).
But I would like to point out that we must be aware that very little OP was used in
‘systemic’ formulations, if at all, in those early days; NB; ‘systemic’ infers
that the OP has to be in a ‘fat soluble’ formulation and capable of penetrating
through to the central nerves and therefore relevant to the basic mechanics of my theory.
Most OPs were more widely used as non-systemic ‘contact’ aqueous based liquid
formulations for use in dip baths, spray-ons and ‘back rubs’ or as powders in the
early days. In fact, most of the OP products are still applied in the third world
countries and in the USA/Australia are still formulated as non systemic products.
- Furthermore, NOAH’s statements at this point
fail to encompass the basic prerequisite of my theory that it is the ‘phythalimido’
type of OP formulation – phosmet – that fits the BSE facts and its use did not take
off in the UK until the mid 1970s.
Phosmet
- At paragraph 26 of [WS270] NOAH now begin to
address my correct theory – ‘phosmet’ as the causal agent of BSE. But I consider
their response is too generalised.
- For instance NOAH state that phosmet is licensed
for use in most of the major livestock producing countries (paragraph 26 of WS 270)
without stating which countries, at what dose rates, whether applied for warbles, lice,
mange etc, whether as a ‘systemic’ or ‘non systemic’ formulation, etc?
- The only country which has compelled the use of
phosmet in its ‘systemic’ pour-on type of 20% concentration formulation (and that does
not mean the ‘spot on’ or ‘spray on’ types) for warbles at 20mg/kg dose is the UK;
please see the chart of global phosmet usage in relation to the global distribution of BSE
on page 101. The only other countries that have used systemic pour-on phosmet on cattle
for warble control were Ireland and France; interestingly these countries make up the
majority of other countries afflicted with endemic BSE, albeit suffering a relatively much
smaller incidence than the UK. Ireland did not introduce phosmet until 1978 – at the end
of its warble campaign – and even then, although hardly used, it was used as a 6mg/kg
dose as a once annual dressing (see O’Keefe paper for dose of active ingredient used) in
competition with three other types of OP warblecide – fenthion, famphur and cruformate.
However, after the warble campaign ended in Ireland, the dose of phosmet was increased to
a 10mg/kg bodyweight dose to include a fourteen day repeat treatment for any farmer who
wanted to use the product (however many times a year) for controlling lice on a voluntary
basis – I believe that this explains the sudden increase in BSE incidence in Ireland
over the last four years – as a delayed lag response to the increased dose rate of
phosmet.
- Again, France only used phosmet on a voluntary
basis over a short period in the 1980s when only 150,000 doses were used per year
according to the enclosed letter from the French authorities. Phosmet use was minimal in
relation to the much more intensive use of its popular competing compounds – fenthion,
neguvon and Ivermectin. For instance, Neguvon was used in France at 800,000 doses in 1991.
Phosmet is also used systemically at a 20mg/kg dose for controlling ectoparasites in pigs
in France, as well as in Switzerland, and the fat soluble residues of this chemical could
have entered cattle via the tallow ingredient of feedingstuffs – used intensively in
these countries.
- In view of the aforementioned, NOAH’s statement
that "significant and similar levels of use of phosmet for warbles took place in UK,
Ireland and France" (paragraph 28 of WS 270) is incorrect.I have never been able to
obtain any details of doses of phosmet used in the UK (see enclosed correspondence but,
its usage in the UK must have risen once its competing OP warblecides – fenthion and
famphur – were withdrawn from use in 1985. Dr Andrew’s statement to the Inquiry claims
that the UK sales figures for phosmet have been lost (WS 269A paragraph 45), which in my
view undermines NOAH’s statement where they state that phosmet was used equally in
Eire/UK/France.
- However, A H Andrew’s paper on abnormal
reactions to OP warblecides [M54 Tab11 page 25] indicates that 8,560,000 doses of
warblecides were used in the UK over the four year period of his survey (1975 – 1978).
This suggests that 2,140,000 doses of OP warblecide were being used in the UK each year,
prior to treatment becoming compulsory over entire zones in the early 1980s. Considering
that Tony Andrew’s paper indicates that 11 brands of OP warblecide were being employed
at that time – 4 of which were phosmet brands, then one can estimate that approximately
778,000 doses of phosmet were annually used in the UK from the mid 1970s up until the
advent of the 2 times annual compulsory treatment measures introduced in 1982, and then
the removal of phosmet’s competing brands of OP in 1985. Thus one can argue that the use
of systemic phosmet for warble control in the UK was several magnitudes greater in the
late 1970s-early 1980s over a far longer duration in comparison to the relative
insignificant usage of phosmet in France and Ireland.
- Contrary to the picture that NOAH has painted in
Mr Cook’s statement, the actual timing, distribution and intensity of phosmet usage and
tallow consumption does indeed correlate with the spatio temporal epidemiology of BSE in
Europe. The correlation involves a delayed lag period due to the prerequisite that phosmet
must bio-accumulate in the bovine foodchain to assist in the overall concentration of
phosmet exceeding the threshold of toxic tolerance in the cow – coupled to the fact that
I have hypothesised that the toxicological initiation of the conformational change in the
prion protein is an ‘in utero’ event, which subsequently requires several years of
incubation period prior to the eruption of the outward symptoms of the disease.
Geography
- NOAH in Mr Cook’s statement do not mention the
fact that the various warblecides on the market employ different modes of application (eg
spray on, spot on or pour-on) and different types of carrier medium (oil or water based,
etc) which are designed to assist the active ingredient in performing its specific task
once it has been delivered onto/into the cow. Essentially my BSE thesis centres on the
‘systemic’ oil based pour-on warblecides which are delivered along the entire length
of the cow’s spine (just millimetres from the prion protein!) and the base of its brain.
Furthermore these types of chemical are deliberately designed to penetrate through the
skin to exterminate warbles whilst inside the cow. These chemicals even had to kill those
warble larvae that had congregated in the fatty tissues of the spinal cord.
- I believe that the ‘spot on’ and ‘spray
on’ types of contact warblecide – used in countries such as Hungary, Poland, Denmark,
Holland, USA, etc wisely employed far less total active ingredient per animal and were
delivered directly onto the warble larvae itself at the stage of its life cycle when the
creature popped out through the skin of the COW’s back as a mature larvae.
- Thus NOAH’s generalised chart of the different
countries employing or about to employ warble fly policies (WS 270 paragraph 31) is
irrelevant to my theory. For instance, I refer to a letter from the German Pesticide
licensing authorities that declares that they have never permitted the use of
‘systemic’ type treatments on cattle in Germany. And again, Denmark did not employ
systemic pour-on phosmet, they used spot-on fenthion. This explains why Germany and
Denmark, etc, do not have an endemic BSE problem. NOAH incorrectly state that Jersey
farmers had treated their cattle against warbles. A letter from Jersey’s Chief
Veterinarian published in "Farming News" has already pointed this error out to
NOAH.
- The point that I would make in relation to Jersey
and Guernsey is that the same systemic phosmet warble fly liquids were used intensively
for controlling lice at a double 10mg/kg dose – for lice pose a significant problem in
the warm, mild climate of the Channel Islands. Also tallow and ‘protected fat’ were
feddingstuff ingredients that were in strong demand with Jersey and Guernsey cattle
breeders who bred cows to produce milk with a very high butterfat.
- Guernsey suffered more BSE than Jersey simply
because the soils of Guernsey are very deficient in copper and selenium in relation to
Jersey. The results of my own global field surveys of isolated clusters of spongiform
disease have consistently demonstrated that both selenium and copper deficiency is a
crucial prerequisite that must be fulfilled before any type of sporadic spongiform disease
can erupt. Copper and selenium deficient areas of the BSE affected countries – such as
Hampshire, Norfolk, Guernsey, Brittany, etc, - have all hosted the highest intensities of
BSE outbreak relative to the overall BSE rates of their particular country. This is simply
due to the fact that copper and selenium are essential co factors for several enzyme
systems that are crucial for scavenging free radicals; thus, once copper and selenium are
in short supply, the body is not so well equipped to mop up these highly lethal radicals.
Thus, when free radical chain reactions are initiated in the CNS membranes following
exposure to the systemic types of high dose OP, then the radicals that are generated as a
direct consequence will be free to react with proteins like the prion protein in any
animal that is already environmentally predisposed to a deficiency of radical scavenging
enzymes. It is these radicals that can cause protein deformation, which, in turn, kicks
off the pathogenesis of TSE.
- Again, NOAH generalises by referring to intense
usage of OPs on cattle in both Africa and South America (Mr Cook’s statement WS 270
paragraphs 33 and 34), but cannot say whether these OPs were in systemic formulation or
indicate the dose rate applied, the type of OP, or whether permitted for use on
‘pregnant’ cattle. Once again, the context of OP use in Africa and South America,
according to my research, falls a long way short of fulfilling the prerequisites of my
OP-BSE theory.
Timing
- There is a very strong relationship between the
spatio temporal dynamics of systemic phosmet use in the UK and the spatio temporal
epidemiology of BSE incidence. Whilst there is a delayed lag period of approximately six
years, this can be explained by the need for phosmet to have bio-accumulated in cattle to
critical levels as a result of the recycling back of residues (plus the ‘infectious’
oxidative potential of the prion itself) via the tallow fraction of MBM. Also it has to be
born in mind that the intoxication event responsible for initiating TSE pathogenesis
probably occurred in the womb, several years before the outward symptoms of the disease
started to manifest itself. Furthermore if a phosmet induced mutation event was involved,
(one mechanism I suggested in my J Nutritional Medicine paper 1994 [J/NUM/4/43]) – then
TSE may not have emerged until several years later in succeeding generations.
- The reason that the first cases of
‘officially’ recorded BSE were largely born after 1982 is probably due to the fact
that solvent extraction mainly ceased (plus a drop in temperature) in the rendering
factories in the early 1980s, thus permitting the tallow fraction of MBM, phosmet residues
and prions all inclusive, to remain in the feed. Having said that, all vets, farmers and
slaughterers that I have spoken to are adamant that several cases of BSE were trickling
through the system in the late 1970s/early 1980s before the disease was officially
recognised.
- Warble treatment did not become a compulsory
treatment for whole herds in declared zones until the early 1980s. Coupled to the fact
that MAFF were writing to all UK farmers each year urging them to treat throughout the
1980s (and even as late as 1995, then one can assume that phosmet was used at higher
levels in the 1980s than in the later half of the 1970s – particularly since phosmet’s
competing brands of OP were virtually all removed by 1985.
- I should also point out that many types of highly
neurotoxic impurities have been associated with various types of OP technical grades that
have been on the market – phosmet being one of those OPs that could be contaminated in
this way. As different chemical processes can be employed for manufacturing the same type
of OP and some of those processes could predispose more favourably for the formation of
unwanted ‘impurities’, then research should be executed to see if any such changes
were implemented in the manufacturing process of phosmet at any time during the warble
campaign. Conditions of storage of phosmet can also considerably influence the toxic
potency of the chemical.
- It should be pointed out that Northern Ireland did
not take up the use of phosmet until a long time after 1969 – when Northern Ireland
first kicked off its warble campaign.
- Whilst it is true to say that the UK warble fly
campaign initially only encouraged farmers to treat their cattle in the late 1970s, it is
totally untrue to say that it was never compulsory to treat all of the herd (paragraph 39
of WS 270). Compulsory treatment of entire herds was introduced in the 1980s which gave
rise to my court case in 1984. As NOAH pointed out earlier (paragraph 12 of WS 270), I had
broken the law by refusing to comply with this compulsory requirement to treat my cows.
But in truth, the verdict of my court case indicated that MAFF had actually been working
outside of the law by compelling treatment with a chemical dressing. The Animal Diseases
Act only empowered MAFF to compel treatment with a vaccine or a serum (paragraph 4 of my
InquiryWS23).
- Such an introduction of compulsory treatment of
all cattle in designated zones around the UK in the early 1980s indicates that the use of
phosmet would have increased considerably at this time, particularly as all of its
competing compounds were removed off the list by 1985. Surely this supports my theory and
explains why BSE really got underway by the end of the 1980s.
- Again, NOAH are considerably exaggerating their
position when they suggest that the warble fly campaign was nearly wrapped up by 1981
(paragraphs 45 and 46 of WS 270). Working as a farmer throughout this entire period
myself, I (plus other organically orientated dissidents) didn’t come into confrontation
with this government Warble Order [L9 Tabs 1-5] until 1982, 1984, etc. We were hardly
aware of the existence of such an Order before that time. If we had a warble infestation
in our cattle prior to 1982, we simply used derris powder which was officially sanctioned
up until that time.
- Furthermore, during the 1980s all farmers outside
of the compulsory zones received letters from MAFF urging them to treat all of their
cattle on a voluntary basis as an extra insurance. All farmers received such pamphlets
from the 1980s up until 1995, but I should point out that we did not receive pamphlets
urging voluntary treatment during the 1970s at all.
- NOAH does not mention that the new ‘non OP’
warblecide, ‘Ivermectin’, could not be used on milking cows for economic reasons; for
the licensing criteria stipulated that the milk had to be thrown away for 28 days after
treatment. Consequently, Ivermectin was widely taken up by beef farmers and not dairy
farmers, which answers NOAH’s next point about the beef-dairy differential surrounding
BSE incidence (paragraph 44 of WS 270)– where a considerably higher incidence of BSE
exists in dairy cows as opposed to beef cattle.
- Thus, the explanation for this BSE differential in
beef and dairy cattle partly lies in the fact that beef cattle received ivermectin post
1981 instead of OP warblecides. Furthermore, most beef cattle do not live long enough to
develop the outward symptoms of BSE, plus beef cattle receive nowhere near as much tallow
based feed. Most beef stock are farmed under a less intensive management strategy than
dairy herds and therefore do not receive much feed or milk from a concentrate/artificial
source – particularly the young calves who derive their nourishment from suckling milk
from their mothers. Beef suckler herds are also largely based in the moorland areas of
Britain/Scotland which were largely never designated as warble fly compulsory zones. And,
pertinent to the prerequisites of my theory, beef calves are largely born in the spring
and were therefore at their most ‘chemically vulnerable’ early stages of embryonic
development during the summer months. Eg, at a time when warble fly treatments were not
applied. Please note that there is a 10 fold greater incidence of BSE in cattle that were
born in the autumn. As twice as many cattle are born in the autumn in comparison to those
born in the spring, then there is a five fold greater risk of contracting BSE in cattle
that were in their vulnerable embryonic stages during the compulsory ‘springtime’
warble treatment period in March. This highly significant seasonal fluctuation of BSE
susceptibility – whether it relates to any ‘in utero’ connection or not – has been
totally ignored.
Noah’s Summary (paragraphs 47
to 50 of WS 270)
- NOAH’s summary is irrelevant to my theory as it
focuses on the use of warblecides as a general group – and not the systemic pour-on
phosmet brands.
- Thus if we correctly insert ‘phosmet’ into the
hypothetical template, then we can see that significant usage of the chemical got underway
in the later half of the 1970s, peaking after the imposition of 2 times annual compulsory
treatment measures in 1982, and then gradually tailing off right up until the early 1990s,
leaving a situation today where limited treatment is still occasionally carried out in
very small pockets and on imported cattle, as well as in a voluntary capacity for lice
control. NB, I should also add that zones for warble treatment were declared all over the
southerly/mid areas of the UK in the 1980s (eg Kent, Yorkshire, etc) and not only in the
SW and Wales as NOAH suggests. MAFF’s annual animal health publications depict this.
- If PHOSMET were the cause of BSE, then the
pattern of BSE should look like this – which it does!
- much greater intensity of BSE in dairy cattle
as opposed to beef cattle;
- emerging in the first half of the 1980s;
- peaking in the early 1990s;
- steadily tailing off, with cases occurring all
over the UK but with a greater concentration in the South West and Wales; and
- prevalent to a much lesser degree in countries
which employed systemic phosmet at the 20mg/kg warble doses as a voluntary treatment over
much shorter period – eg France, Eire, Channel Islands, etc (includes the double 10mg/kg
lice dose, but BSE free Australia and New Zealand only licensed it for the single lice
dose)
REPONSE TO THE HEARING ON 5/11/98
AT THE BSE INQUIRY (DAY 78)
- Page 24 (line 12) Tony Andrews states that the OP
warblecides containing famphur as an active ingredient would have been disappearing at the
time when the warble fly eradication came in.
- This is incorrect. Famphur products were for sale
in farm stores – thus competing against phosmet brands – right up until 1985. This is
pointed out in a House of Commons reply to Sir Richard Body in 1985.
- Page 25 line 2 to page 26 line 14 Mr Tasker
explains the sales chronology of the different phosmet formulations. The marketed brands
progressively increased their concentration of active ingredient (5% to 10% to 13.3% to
20%) from the 1970s until present day.
- Whilst I take Mr Tasker’s point about the
relative drop in the total volume of fluid applied as the concentration of formulation
increased, he does then go on to explain how the delivery system for the pour-on pesticide
became more precise (eg, there was less wastage and displaced chemical (Dr Andrews
explains this p 27 line 7) which would imply that a fluid of 20% concentration of phosmet
(albeit less in total volume) instead of a 13.3% or 5% concentration is going to have to
soak through the spinal cord/base of the brain before it permeates the circulatory system
and the main batteries of detox enzymes in the liver where chemical degradation begins.
- Fundamental toxicological principles would suggest
that exposure to a given volume of a toxic chemical at 20% concentration would be more
likely to exceed toxicological thresholds and initiate a pathogenic disturbance in
biological systems, than in the context of an exposure to a relatively higher volume of a
13.3% or a 5% concentration of that same chemical.
- It is interesting that the UK is the only country
in the world to have employed the 20% concentration phosmet brand for warble fly control
– eg at the 20mg/kg dose rate. As the 20% concentration brands largely came into use in
the early to mid 1980s after France and Eire had finished employing phosmet for warbles,
then this may hypothetically explain both the timing and the virtual uniqueness of the BSE
epidemic to the UK.
- Page 28 (line 5) Mr Tasker. I agree with Mr Tasker
that systemic phosmet is "applied along the backline" where it is
"attracted to and dissolves in fat." He confirms a large chunk of my thesis that
phosmet will concentrate in fat. Others have tried to deny the lipophilic properties of
systemic warblecides. Indeed, Professor Prusiner has pointed out that the prion protein is
found in these same fatty regions of the CNS – the regions over which the OP pour-ons
are delivered. PrP is found conjugated onto the phospholipids in the liposome structures
of these regions.
- Page 30 (line 21). Mr Tasker. I thought that
ivermectin had a 28 withdrawal period for milk and not 2 days. It was certainly a 28 day
withdrawal period during the 1980s.
- Page 33 (line 1). Mr Tasker. According to the
package label for the Young’s phosmet pour-on that was registered in Australia in 1995,
there is no advice or recommendation given for a 14 day repeat treatment of the 10mg/kg
lice treatment.
- Page 34 (line 5) Mr Tasker. I find it hard to
accept that O’Keefe’s study has applied phosmet onto cattle at such a markedly
different dose rate to that employed in the real life context. After all, this whole study
was designed to safeguard public health in Eire by applying all of the different types of
systemic OP warblecides onto milking cattle at their prescribed Eire dose rates, and then
measuring the various residual contaminants in the milk resulting from those OP treatments
for several days after the treatment. These O’Keefe studies tested fenthion, famphur and
crufomate warblecides at the dose rates prescribed in Eire, so it would seem unlikely that
phosmet was suddenly tested at an irrelevant dose rate in these trials.
- Page 37 (line 17) Mr Tasker. It looks as though Mr
Tasker is correct in pointing out that I have made a ten fold mistake in the calculation
of the actual dose rate of the phosmet pour-on for pigs. The different authorities had
merely supplied me with the concentration of formulation and amounts of the fluid
poured-on to pigs.
- However, the 10 times higher dose rate of phosmet
for pigs actually improves the viability of my theory and demonstrates that the tallow
fraction of cattle feed in countries such as Switzerland/France (which utilised large
amounts of systemic phosmet for pigs) would have contained higher levels of residues of
phosmet which would infer greater toxicological significance.
- Whilst pigs have been recorded to suffer from the
more conventional OP induced delayed neuropathy in the literature, pigs are not
susceptible to prion disease as a species. Furthermore, pigs are routinely fortified with
large doses of copper, which would occupy and thus safeguard the histidine sites at the
copper domain on the prion protein against modification by OPs. When copper is in short
supply in the CNS however, the histidine residues on PrP become ‘vacant’ and therefore
vulnerable to occupation or interaction with competitive organic foreign chemicals or
metals.
- Page 38 (line 5) Mr Walker. Phosmet was not
permitted for use upon milking cows in the USA because of the US pesticide authorities
tougher line taken on the health problems posed by phosmet’s residues appearing in the
milk. Consequently, phosmet use was very limited in the USA, being used largely as the
‘non systemic’ water based spray-on (at 2mg/kg dose), pour-on, back rub, etc I have
some usage figures for Colorado-Wyoming states that indicate very low use of phosmet in
relation to other OPs.
- Page 48 (lines 4 and 23) Dr Marrs. Dr Marrs
himself cites one study ‘Good J et al, J Neurol. Neurosurg. Psychiatry 1993 56
290-294’ in his JMPR 1994 report which highlights ultrastructural abnormalities in the
motor endplates of a human exposed to sub acute doses of phosmet. So I am surprised that
he is ruling out structural changes in the peripheral and/or central nervous system that
might lead one to expect that phosmet induces anything other than an
anti-acetylcholinesterase mediated effect on nervous tissue.
- It is well recognised that phosmet induces
cerebral edema with gliosis in exposed victims (hydrocephalus in exposed fetuses) which is
largely disrelated from the anti-cholinesterase effects of phosmet’s oxon metabolite.
Thus the pathology induced by phosmet intoxication, plus phosmet’s disturbance of
vitamin C and DNA-RNA exchange, does indeed suggest that some of phosmet’s effects are
disrelated to its cholinergic effects. In fact, these disturbances probably reflect the
well recognised impact of chain reactions of various free radical species that are
generated by phosmet intoxications. The free thiol radicals associated with the
phthalimido-N-methyl mercaptan metabolite group of phosmet could well interact with
sulphur amino acids in proteins causing conformational changes. Furthermore, this
mercaptan group serves as a copper chelator forming a tightly bonded ring with copper –
explaining the spongiosis pathology that is invoked by phosmet. This would deprive the
copper domain of PrP of a copper supply, leading to a breakdown in CNS activity of
superoxide dismutase activity and in the brain’s resistance against superoxide radical
induced oxidative stress. Such free radical disturbances would also exert knock-on effects
on the signal transduction cycle and protein kinase mediated phosphorylation within
intoxicated cells.
- Phosmet has also been shown to increase the turn
over of glutamate oxaloacetate transaminase, demonstrating another non-cholinergic effect
which resembles the pharmacokinetic characteristics of other members of the phthalimide
family such as thalidomide.
- The non-cholinergic neurotoxic effects of
impurities, such as chloromethylphthalimide, which have been commonly associated with the
technical grades of phosmet used in the field, should also be recognised as potential
influences in the pathogenic consequences of phosmet intoxications.
- Page 86. (line 9) Mr Cook. It should be pointed
out once more that the 28 day withdrawal period of milk following treatment with
ivermectin resulted in a zero use of ivermectin upon milking cows for warble control.
Ivermectin was used on beef cattle for warble control however, perhaps explaining why BSE
largely affected dairy cattle (which only received OPs) and remained at a low level in the
beef suckler cattle.
- Page 86. (line 19) Mr Walker. My comment on the
work carried out by Professor Shaw is that, once again, the test protocol fails to test
the key prerequisities of my theory because it employs a recombinant PrP model that is
totally divorced from the ‘in vivo’ context of PrP as a living protein, interacting
with its cellular environment, etc. The recombinant PrP does not contain the glycolipid
anchor, nor does it contain copper (which bonds to the histidine residues of the
octapeptide repeat region of PrP) or side chains that are crucial components required for
the putative mechanisms of PrP conversion that I have proposed in my various publications.
For instance, outside of the cellular context it is impossible to initiate any free
radical generated impact of chronic phosmet intoxication using recombinant PrP. There is
no cell membrane where lipid peroxidation could be initiated, and no copper ions for the
resulting peroxides to interact with. The resulting formation of the hydroxyl and Cu 111
radicals would also require the presence of side chains, other proteins and free
transition metals to exert their pathogenic impact.
[Secretariat Note: An annex to this
statement will be published in due course which will give the BSE Inquiry references to
documents referred to in the statement] |
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