John Mark Purdey,
farmer: born Much Hadham, Hertfordshire 25 December 1953;
married 1974 Carol MacDonald (one son, one daughter;
marriage dissolved), 2006 Margaret Urwin (two sons, four
daughters); died Elworthy, Somerset 12 November 2006.
On paper Mark Purdey was a
Somerset dairy farmer, but he will be remembered for his
long-running campaign to prove that "mad cow"
disease was linked, and indeed caused by, the use of the
organophosphate pesticide Phosmet, used to treat skin
parasites on domestic livestock. The theory was as
unconventional as Purdey himself.
The tall, unkempt Purdey
saw himself as a scientific sleuth, an eco-warrior fighting
against the power and dirty tricks of "the
Establishment" , an unholy alliance of the agrochemical
business, the academics in their pay and the government
officials whose job it was to cover-up ministerial blunders.
He called himself an
"underground scientist" and "heretic" ,
and his one-man campaign was eagerly taken up by the media,
obsessed as they are with the power of personality over
factual credibility. Indeed, it was not just the media who
lionised Purdey. He also became an unlikely hero of the
likes of Ted Hughes, the Prince of Wales, Michael Meacher
and Lord King of Bridgwater, the former defence secretary
who once described Purdey's work as a "classic piece of
scientific investigation".
In truth, Purdey was the
antithesis of a classically trained scientist. He was
self-taught and, although impressive in his knowledge, he
often lacked the attention to detail that a science degree
or two might have inculcated in his methodology. The fact of
the matter is that Purdey's theory did not withstand the
test of time nor of scientific enquiry - something that he
could not bring himself to admit. He died of a brain tumour
on Remembrance Sunday.
Mark Purdey was born on
Christmas Day 1953 in the Hertfordshire village of Much
Hadham. He belonged to the Purdey shotgun family, which
includes a long line of somewhat eccentric thinkers. His
ancestor James Purdey walked from Inverness to London to set
up the shotgun business, and his grandfather Lionel
campaigned to get Lord Kitchener to acknowledge that shell
shock was a real illness.
As a child Purdey took up
birdwatching and one of his earliest memories was seeing a
blackbird quiver and die after a wheat-field had been
sprayed from the air. It left a haunting impression that
evidently led to his interest in agricultural pesticides. He
was sent to Haileybury but was expelled after breaking out
at night to visit some girlfriends - an early sign, perhaps,
of his growing disrespect of authority.
In 1984, now a dairy farmer
in the Brendon Hills in Somerset, Purdey challenged the
Ministry of Agriculture's insistence on the use of
organophosphates on his cattle to eradicate warble fly. The
challenge went as far as a High Court battle, which he won,
making him front-page news and a household name, at least in
farmhouses up and down the country.
Towards the end of the
1980s Purdey became interested in the growing problem of
bovine spongiform encephalopathy (BSE). He postulated that
the use of organophosphate pesticides - which were poured on
the backs of animals - could be causing the nervous
condition.
The vociferous
anti-pesticide lobby of the green movement took up the case
with gusto, as did some leading organic commentators in the
media, John Humphrys being one influential supporter.
Unfortunately as more and more scientific evidence emerged -
either through laboratory experiments or number-crunching
epidemiology - Purdey's hypothesis began to look
increasingly implausible.
In response to the media
campaign that grew up behind him, the Medical Research
Council undertook experiments in 1995 to test Purdey's
theory. But the results did not support his hypothesis. The
study was subsequently rejected by Purdey, who claimed that
the MRC scientists had used the wrong chemical formulation.
However, it became
increasingly clear that contaminated meat-and-bonemeal feed,
rather than pesticides, was behind the BSE epidemic. When
the Government took the first measures to stop contaminated
feed being eaten by cattle, the effects soon became apparent
in the form of a significant decline in the number of
outbreaks.
Purdey started to modify
his theory and invoked the idea of a complex interaction
between ultraviolet radiation, minerals in the soil of
pastures and pesticide use. His research took him as far
afield as Iceland, Colorado, Japan and Australia. He had
little money and often slept rough, forming unlikely
companionships with a Hell's Angel, an Aboriginal elder and
a Slovak au pair girl.
He won limited support for
the idea by a few mainstream scientists who took some
interest in the role of copper and manganese minerals in
affecting the prion protein, believed to be the causative
agent behind BSE and human CJD. But no knowledgeable
researcher in the field believed for one moment that the
Purdey hypothesis could explain the spread of BSE in
Britain.
The BSE Inquiry (1998-2000)
led by Lord Phillips of Worth Matravers took evidence from
Purdey but dismissed his hypothesis, arguing that it was
both unlikely and unconvincing. Needless to say Purdey came
back fighting but he reserved his greatest wrath for a
subsequent committee of six experts led by Professor Gabriel
Horn of Cambridge University, who was charged by the
Government to answer perhaps the most important question of
all - why did Britain suffer from BSE in the first place?
It was of course the
question that Purdey was trying to answer all along. We know
now what spread the disease - contaminated feed. But what
actually triggered the start of the epidemic in the first
cow to be infected?
The Horn Committee came to
the conclusion that it was caused by feeding sheep remains
infected with scrapie disease to very young calves. Yet
again the Purdey hypothesis had been considered and
dismissed by experts.
Like Don Quixote tilting at
windmills, Purdey railed against the "bogus" and
"libellous" findings of the "biased"
Horn report. He claimed yet again that he was a victim of
establishment deceit and intrigue. Yet the simple fact is
that Mark Purdey had an interesting scientific hypothesis
that was tested and found to be wanting - like many
scientific hypotheses. There was no shame in being wrong,
but it was a shame that he could not bring himself to admit
it.
Steve Connor
The reason my brother Mark
Purdey did not accept either of the main BSE hypotheses, writes
Nigel Purdey, was because they do not demonstrate Koch's
postulates, despite millions of pounds' worth of research
conducted over 20 years. If someone had conducted an
experiment in which meat and bone meal (MBM) fed to cattle
produced BSE then this would have satisfied him. The 10-year
government experiment in which MBM was fed to cattle
produced no cases of BSE.
BSE brain homogenate
inoculated or fed neat to cattle can produce BSE, although
scrapie homogenate failed in this respect. But in
"life" cattle were not exposed to homogenate in
this way - they ate MBM. Science must be precise and this
research in no way proves the MBM theories.
An early inspiration for my
brother was the work of I.H. Pattison, who found that a
copper-chelating chemical, cuprizone, created a spongiform
encephalopathy (SE) in animals, without the requirement of
any infectious agent. This type of encephalopathy turned out
to be non-transmissible. But it begged the question, if
there was a substitution by another metal or metal
microcrystal (through an environmental exposure), at the
vacated copper sites on the prion protein you might get an
SE that was transmissible - as in BSE, CJD. This Mark
considered was the primary cause of this class of diseases
and it was this that he was still researching when he became
ill.
Mark never considered he
had all the answers but he felt that, with perhaps another
five years' work, he could have located the final pieces of
the jigsaw and proved his theory.
Nigel Purdey
