Examination of witness
(Questions 1 - 19)
TUESDAY 9 FEBRUARY 1999
PROFESSOR SIR
JOHN R KREBS
Chairman
1. Professor Sir John, welcome to this first
session of our new inquiry into badgers and bovine tuberculosis.
Can I begin with something of an apology to you? A number of our
colleagues on the Committee have been held up for a variety of
personal and parliamentary reasons beyond their control. I think
we will be joined during the course of this session by some of
those others. Several of our Members are on a Standing Committee
elsewhere. I think we will see them join us later during the session.
Can I express our gratitude to you for coming today? You obviously
have not had to produce a memorandum of evidence to the Committee
but we have had a very substantial memorandum in the shape of
your original report to the government. I wonder if I could ask
you to introduce yourself and to give us something of your background
that led to the government appointing you to undertake that original
inquiry?
(Professor Sir John Krebs) Thank you very much. I
very much welcome the opportunity to come and give evidence before
you. My current post is chief executive of the Natural Environment
Research Council, which is a non-departmental public body sponsoring
and carrying out environmental research. My background is as an
academic in zoology from Oxford University. I was invited by the
then Agriculture Minister, Douglas Hogg, to chair the Scientific
Review Group that looked into the question of the relationship
between bovine tuberculosis in cattle and badgers. I carried out
that review during 1996 and 1997 and submitted the report to the
then Agriculture Minister, Dr Cunningham. That is the document
you have with the bright orange cover.
2. Thank you, Professor. Perhaps I could begin
by asking you about the terms of reference for that inquiry. I
think it might be helpful to put those terms of reference on the
record. "To review the incidence of tuberculosis in cattle
and badgers and assess the scientific evidence for links between
them; to take account of EU policies on reducing and eliminating
incidence of tuberculosis in cattle; to take account of any risk
to the human population; and accordingly to review, in the light
of the scientific evidence, the present government policy on badgers
and tuberculosis and to make recommendations." When those
terms of reference were set, were you given the opportunity of
discussing them with ministers and the ministry before they were
finally agreed for your review group?
(Professor Sir John Krebs) Yes, I was. The terms of
reference were discussed. I felt satisfied with them. My own view
and that of the group that I chaired was that the terms of reference
were enabling rather than proscriptive. As you will see from the
report that we wrote, we felt free to range quite widely in looking
at the scientific issues related to the bovine tuberculosis problem.
The terms of reference clearly gave a focus on the issue of badgers
because that was one of the more contentious areas in an area
of continuing concern and debate, but we ranged much more widely
than that, as you will have seen in the report.
3. No members of the review group were dissatisfied
with those terms of reference?
(Professor Sir John Krebs) I can say that with confidence.
4. There has been a degree of criticism from
some of the witnesses. We have received oral and written evidence
that the terms are very proscriptive and already we are in a sense
prejudging the outcome because of the link between badgers and
cattle.
(Professor Sir John Krebs) We were asked to review
the evidence for a link and there was a focus on badgers in the
terms of reference. As you will see in the report, we looked at
other possible sources of TB infection in cattle, including both
cattle to cattle transmission and other possible wildlife sources.
We treated the terms of reference as not being a proscription
but to enable us to get on with the job.
5. Do you understand the sense of disappointment
that some farmers have expressed to me certainly that you laboured
mightily for 18 months or two years and just concluded that there
was not enough evidence to conclude anything?
(Professor Sir John Krebs) I can understand their
disappointment, but we debated that in the group long and hard.
I felt -- and my group agreed -- that it would be inappropriate
to come to a conclusion without sufficient evidence. The fact
of the matter is that it is one of these situations where there
is uncertainty. I believe that, where there is uncertainty, the
scientific experts should not try to provide an answer; they should
admit that there is uncertainty. Indeed, that is part of the official
guidelines that the government operates under for receiving policy
advice on science. I sense the disappointment but I am afraid
that is the reality.
Chairman: I think this Committee might
welcome that honesty. That has always been our experience of scientists.
Mr Mitchell
6. What is there uncertainty about? You think
that some of the evidence supports the view that badgers are a
significant source of infection in cattle. If that is clear, why
are we messing about?
(Professor Sir John Krebs) The uncertainty arises
partly in weighing up the sum of that evidence. The sum of the
evidence in the view of me and my committee was that there is
a link between badgers and bovine tuberculosis in cattle, but
there are others, including possibly some people in this room
now who do not accept that. There is a bit of uncertainty there
but I would say that is relatively small. The bigger area of uncertainty
is this: given that the weight of evidence shows that there is
a link between bovine tuberculosis in cattle and badgers, we go
on to ask two questions. How important are badgers in contributing
to the problem? There may be a link but it may be only five or
ten per cent of the problem, or it may be 90 per cent of the problem.
We simply do not know that. The second thing is, if there is a
significant contribution -- let us say, 40 per cent or 60 per
cent or whatever -- we still do not know whether culling badgers
is an effective way of reducing or eliminating the problem. The
reason we do not know that is because, in the past, the MAFF people
in charge at the particular time involved had chosen to implement
a culling policy without asking the question how they would evaluate
whether that culling policy was or was not effective. That is
what our proposal will allow the present government to do. It
is uncertainty about the quantitative contribution of badgers,
uncertainty about the effectiveness of killing badgers as a control
measure and, thirdly, uncertainty about the cost effectiveness.
It may be an effective way of controlling the disease but it may
be, all things considered in the round, not the most cost effective
policy to implement in the long run.
7. Is this not scientific perfection? While
the disease spreads, you are nit-picking. On a priori grounds,
there is a correlation and it stands to reason that culling must
clear the problem. I still do not see what is holding you back,
apart from gathering more scientific information.
(Professor Sir John Krebs) I am afraid that history
is littered with cases where people have jumped to hasty conclusions
and set off in the wrong direction and they have regretted it
later on.
8. They are usually politicians, not scientists.
(Professor Sir John Krebs) I had to play the role
of a scientific expert and, in my view, it is not my role to decide
on policy. That is the job of ministers. My job was to evaluate
the scientific evidence and provide, on the basis of scientific
evidence, the options for the way forward. I do not see it as
prevarication or scientific nit-picking; I see it as a statement
of the way the world is. We simply do not know and we need to
find out before we do something.
9. Finding out keeps scientists in work.
(Professor Sir John Krebs) Someone has to do it, yes.
Mrs Organ
10. Given that there is such uncertainty about
the link, about the cause, about the methods of transmission and
we know so little, why were you happy that the terms of reference
of this were bovine tuberculosis in cattle and badgers? If you
start with the presumption that it has to come from badgers, that
the wildlife reservoir of badgers is enough to cause the transmission,
are you not already as a scientist rather skewing the work that
you are doing? It is a bit like saying there has been an almighty
rise in cookery programmes on Channel 4 and a rise in the incidence
of TB in cattle so let's have a look at the link there.
(Professor Sir John Krebs) It was a hypothesis at
the start that had been developed through previous research and
previous MAFF interventions, but I would reiterate what I said
to the Chairman at the beginning: although that was written in
the terms of reference as a starting point, we very carefully
scrutinised alternative explanations. It did not presuppose the
outcome; it simply provided a starting point.
11. How much were you determined by the fact
that, when farmers are asked to consider why their cattle may
have TB and they can look at it from either it is a cow that has
been brought in or whatever, because there is, you will agree
in the West Country surely, a mythology that there are badgers
in abundance and that TB breakdown is such, very often farmers
are filling in the form saying, "It is to do with the badgers
on my land". How much was that driving you?
(Professor Sir John Krebs) It was not the evidence
from the report forms, the forms filled in by the vets, the TB49
forms. In our report, we recommended that that form should be
substantially revised, which I believe it has been, to improve
the quality of reporting. The evidence that we looked at did not
relate to that form but it related to factors such as the likelihood
of different wildlife species carrying the disease and carrying
the disease for sufficient length of time for the disease to develop
to a stage, within the wildlife animal, that they would be shedding
bacteria into the environment. Who are the potential criminals
who have got the goodies on them? It was evidence related to which
wildlife species come into contact with cattle. You may get species
that have the disease but never come anywhere near cattle. There
was some evidence on the regional distribution of the disease
in relation to the regional distribution of different wildlife
species, but that is relatively weak. There was then some circumstantial
evidence -- but nevertheless significant circumstantial evidence
-- from the past, from cases like Thornbury, Steeple Leaze and
Hartland where badgers had been removed in the early 1980s and
that appeared to lead to a substantial drop in the incidence of
TB in cattle over quite a long period. When you look at all these
bits of evidence together, no one piece of evidence is enough
to nail the case but the weight of the evidence makes it a very
strong case.[1]There
will be other people who look at that weight of evidence and say
it does not prove anything.
12. We have been looking at this problem for
years and years, 25 years at least. Has not part of the problem
been that we have not made any progress, from either MAFF's previous
research or other programmes, because we have focused so much
on the badger? We would not be in this position now, with you
here today, if we had possibly had a wider aspect of looking at
other sources of bovine TB in cattle, if we had not gone down
the route of saying, "This is the culprit. It is the badger",
and then we have a self-fulfilling prophecy and we have not made
any headway in 50 years.
(Professor Sir John Krebs) It is not quite 50 years.
It is since the mid-1970s when an infected badger with bovine
tuberculosis was first post mortemed and the disease was identified.
The reason that we are in the position that we are in now is,
in my view, not to do with the focus on badgers but to do with
the way in which policy and evidence have been intertwined in
the past. This relates back to Mr Mitchell's comment about why
do we need more evidence; why not just get on and do it. That
has been the policy in the past: get on and do it without finding
out whether the thing you are doing is really the thing that is
going to have an effect. That is why we are in this situation
at the moment. It is not because we have focused on badgers; we
just have not approached it in a way that policy is based on evidence.
Chairman
13. You obviously published your report some
time ago now. Has anything happened since then to make you doubt
the validity of any of your conclusions? Is there anything else
you would wish to have said and did not say in the light of what
we have learned since then?
(Professor Sir John Krebs) Nothing significant.
14. Nothing very significant or nothing at all
significant?
(Professor Sir John Krebs) Nothing that would warrant
me to change the conclusions in the report.
Mr Mitchell
15. Perhaps it is like a police inquiry where
it is all focused on one suspect and the evidence is therefore
being pursued against that suspect with a neglect of evidence
against other potential suspects. Is not the real problem though
that there just has not been enough research? The expenditure
has been too geared towards culling and not enough towards research;
whereas in New Zealand, as you say in the report, it is the other
way round. If that is the record of the past -- and I think you
are critical of the amount spent and the effort put into research
-- are you satisfied that MAFF is acting on your recommendations
to increase current expenditure?
(Professor Sir John Krebs) MAFF, as I understand the
figures, have increased their total expenditure on the problem
of bovine tuberculosis from in the region of 16 million to in
the region of 27 million. I also understand that the bulk of that
increase is related to research, or a significant part of it is
related to research. Of course, in implementing the recommendations
in my report, the culling becomes part of research because the
culling is being carried forward in a way that will be scientifically
rigorous in enabling us to evaluate its impact and its cost effectiveness.
I do believe that MAFF has increased its research budget. I do
not really think that I am in a position to judge whether they
have increased it enough.
16. I was going to ask you that. Why not? You
must have some idea. You have been so critical of their past record.
(Professor Sir John Krebs) First of all, I do not
really have a detailed evaluation of what the research requirements
would cost and, secondly, even if I did have that, I do not know
what the conflicting requirements are within MAFF's budget.
17. You are speaking like a civil servant, not
a scientist.
(Professor Sir John Krebs) I am just talking like
a pragmatist.
18. The research is going to be contracted out.
This is the new fashion in MAFF.
(Professor Sir John Krebs) Some of it will be, yes.
19. Do you think that will make a difference
either way?
(Professor Sir John Krebs) In my opinion, MAFF had
not always in the past sought the best scientists to commission
for their research and the way to seek the best scientists is
to offer open competition.
1 Note by Witness: See chapter 2 of the Krebs
Report. Back
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