Select Committee on Agriculture Minutes of Evidence


Examination of Witnesses (Questions 80 - 99)

WEDNESDAY 29 NOVEMBER 2000

PROFESSOR SIR JOHN KREBS AND MR GEOFFREY PODGER

  80. We have to trust the French?
  (Professor Sir John Krebs) There has to be an element of trust in it, absolutely.

  81. Do we?
  (Professor Sir John Krebs) Referring back to a comment that I made earlier, when we asked at the beginning of the Agency, looking not at BSE controls but at meat inspection more generally in abattoir performance, where do we come in the European league table, we came about half way down near the French, so the question could be asked about us. Is there any reason to trust the Brits?

  82. You also said in respect of BSE our controls are the most effective and we are very high on the league there.
  (Professor Sir John Krebs) I said I do not know because we do not have the data, but I would imagine we would do well because we have been through a longer and more painful experience than other countries. It is quite right, given the experience we have had, that we should have tighter controls than any other country. We still have more BSE cases this year than any other country in Europe by a long way. As to whether the controls in other countries are inadequate given their level of BSE, that is up to the Commission to check and that is why I am very pleased that the Commission is going in to check a number of Member States as we speak.

  83. You also said that you were not sure at this stage whether the incidence in France is just a step up to a new level or whether it is the beginning of an epidemic. In that state of uncertainty, would not a sensible precautionary principle be to ban the stuff?
  (Professor Sir John Krebs) It depends on what you think a precautionary principle implies. To me, it implies working with the knowledge you have, recognising the uncertainties and taking proportionate action. There is an element of judgment there at the end of the day as to what constitutes proportionate action but in my view, given the knowledge we have now and the uncertainty surrounding that knowledge, we are not in a position to recommend that on risk grounds. We could do it on nationalistic grounds, but not on human health risk grounds.

  84. You are saying we do not know whether they are enforcing it effectively. We do not know whether it is the outbreak of an epidemic, but we should still make a judgment that we do not ban it.
  (Professor Sir John Krebs) We make a judgment on the knowledge we have now and we are prepared to change our judgment if the knowledge changes. One important piece of information will be the report of the European inspection team when they have been to France.

  85. You are not saying to them, "Remove the ban on our beef", because you are not going to touch the subject.
  (Professor Sir John Krebs) That is not our responsibility.

  86. But you are saying, "Our controls are the most effective in the world and you have a lot to learn from us, but we are not going to ban your beef and we think your controls should be improved." What lessons would you learn from that if you were a French bureaucrat?
  (Professor Sir John Krebs) I am not a French bureaucrat and I do not want to necessarily think about what lessons French bureaucrats learn, but I have said clearly that the scientific case for the French ban on United Kingdom beef in our opinion is non-existent. It is not a scientifically based argument. I would not like to put us in the position on my recommendation of the French saying, "Well, the United Kingdom has banned our beef but it is not a scientifically based argument." My job is to provide a rigorous assessment and risk management advice to government. If people want to base their argument on other grounds, that is their business, not mine.

  87. In general, how does the FSA calculate risks? How do you allow for uncertainty?
  (Professor Sir John Krebs) We rely on expert advice in calculating risk. Usually, if you have uncertainty, you take a number of scenarios. You might take a best case scenario if you are an optimist and a worst case scenario as a pessimist and then somewhere in between. If you wanted to estimate the risks associated with meat being imported from France, for example, you could consider what would be the risk under the assumption that all the rules are being breached. What would be the risk under the assumption that all the rules were being fully applied? What would be the risk under the assumption that the rules are somewhat half way or some proportion in between? That is in general how one deals with risk assessment under uncertainty. What is very important is, when you do that kind of risk assessment, you do not get seduced by precise numbers and quantitative detail. If I did that kind of risk assessment and I came back to you and said, "The number of 0.00132", you should say, "Rubbish. Give me an answer to an order of magnitude. Is it of comparable order of magnitude to the risk from United Kingdom beef or is it a different order of magnitude? What is your uncertainty in that estimate?" We have to be willing to accept that we cannot estimate things precisely and quantitatively. We can talk about orders of magnitude and relative assessments for different countries.

  88. And publish the parameters.
  (Professor Sir John Krebs) Yes, one has to make it completely clear.

  89. Do you differentiate between risks according to exposure of abattoir workers and consumers or farmers? Do you make distinctions here?
  (Professor Sir John Krebs) Occupational risks?

  90. Yes.
  (Mr Podger) In work carried out, if it is thought there might be a particular risk to a particular sector, you would. We normally start from general population risk assessment. One would always ask the question: is there a particular issue for vulnerable groups, which very often there is. Very often, the young, the elderly, pregnant women, people who are immuno-suppressed, for example, in a whole series of areas the risk to them is greater. One of the issues that does arise from time to time is where it appears that a particular group are susceptible and it is very important obviously not just to do a general population risk assessment in which they may become completely hidden, which is obviously your point. One does try to do that and the advisory committees do.
  (Professor Sir John Krebs) For instance, the risk assessment associated with pesticide levels takes into account the most vulnerable groups as one of the multipliers in calculating the acceptable exposure levels.

  91. But you do not publish risks between whether the meat is sourced from different countries. You stay out of that.
  (Professor Sir John Krebs) We have not to this stage published a formal risk assessment of meat from different countries within the European Union, although we are looking at that area and there is work going on in the research community, trying to develop models of risk assessment.

  92. Would that not be a sensible solution, to publish the risks from each country and label that by country of origin?
  (Professor Sir John Krebs) Bearing in mind what we have just said about risk assessment under uncertainty, these risk assessments will be only within very wide bounds. I do not think you would want to put a number on it and say, "This is risk category one, two or three", because there will be a lot of assumptions going into that risk assessment. It is helpful to inform policy judgments but I am not sure that at this stage we have the knowledge that would help consumers to choose. Consumers would probably quite rightly say to us, "If product A has an appreciably greater risk because it comes from country X than product B which comes from here, why are you allowing it to be sold anyway?" I do not think we can substitute consumer choice for risk management.

  93. The Phillips report is full of lessons for everybody. I wondered what you thought the lessons for scientists are, whether they are speak out like Professor Lacey, lose your job, your laboratory and your funding or shut up like the chief medical officer and the chief scientific officer.
  (Professor Sir John Krebs) I am not going to support the view that the CMO and the CSA shut up. The recently retired CSA, Sir Robert May, spoke out very forcefully on key issues.

  94. Is there a lesson in favour of speaking out?
  (Professor Sir John Krebs) Yes, but in general the lesson from Phillips for the scientific community is rather analogous to the lesson that Geoffrey Podger referred to for governments. It is to not get entrenched into defending a position that you took up at the start. Be willing to listen to the challengers. Be willing to change your mind as new evidence comes along. Scientists are human like everybody else and they sometimes get stuck in entrenched positions and resist all the contrary evidence because it disagrees with their favourite hypothesis. That would be a general lesson to everybody involved from the scientists through to the politicians that we should be willing to change our minds in the light of new evidence if the evidence demands that we come to a different view.

Chairman

  95. It is legitimate, is it, always to ask the challengers if their own opinions can be proven or have the same degree of certainty as those defending the proposition?
  (Professor Sir John Krebs) Absolutely. A difficult area is that some fringe people in the scientific community are just that. They are there as irritants but they have no basis for their arguments. Other people are actually serious minority view holders and it is a judgment to distinguish and pick out the ones who have a serious point to make. Your proposal to ask them what the basis of their argument is is an important way of achieving that.

Mr Jack

  96. One of the things that has intrigued me in recent times is the use of the phrase "BSE infected meat". The reason I ask this question is because I think it is relevant to the public perception of risk. Am I right in saying that so far, as far as the actual beef tissue that we eat as meat is concerned, no infectivity has been found in it in the United Kingdom?
  (Professor Sir John Krebs) The tests that have been done by grinding up bits of cows with BSE—brain, guts, limbs etc.,—and injecting those into these mice to see whether the mice develop BSE did not show any infectivity in the meat that we eat. The infectivity is found in the areas that are now treated as specified risk material: the brain, the spinal cord, the dorsal root ganglion.

  97. If we are to develop a proper understanding of where risk comes, which would be from the consumption by human beings of the bits that we have identified with infectivity in them, do we need to change the language that we use and, if so, what role are you playing to get people to focus on where the real risk is?
  (Professor Sir John Krebs) It is an important point. It is quite a sophisticated argument to get across. What we say in simple terms is that the two hurdles that meat or meat products coming into the food chain have to cross are, first, the cattle have to be under 30 months; secondly, the bits of the body that might contain infectivity have to be taken away and destroyed. Those two hurdles ensure that for you, the consumer, the meat and meat products you eat are minimal risk. We cannot say there is zero risk because bits of stuff could get stuck to the carcass or there may still be some surprises for science as to where infectivity lies.

  98. That takes me back to something you touched on earlier, which was the question of the systems that are being used to monitor French imports and possibly others. There were calls I think in The Daily Telegraph that your Agency should give greater clarification on the way in which the assessment was to be done, particularly in the context of animals over 30 months. You said earlier that this was a documentary check and that was the most you could hope for. Are you satisfied that meat entering the United Kingdom from not just France but also other parts of the European Union where, albeit minimal, incidents of BSE have been discovered, are robust in enabling you if necessary to have full traceability to source a particular animal if you either wanted to run a spot check or there was doubt about the authenticity of the evidence on the piece of paper.
  (Professor Sir John Krebs) This is partly a matter for the food manufacturers and retailers. Geoffrey has had quite a lot of conversations with the major retailers on their authentication and traceability systems.
  (Mr Podger) Generally speaking, the major retailers and probably the major meat processors would say they do have traceability on their carcass meat. What we do not have traceability on are meat products which are already made up as meat products before they arrive in this country, for the obvious reason. I think my experience of the food industry is that they find those very difficult to trace back.

  99. In that context, because you rightly counselled us that it was the incorporation of potentially infected tissue material in which there could be a risk, what is the scientific test situation? Can you take, for example, pâté and establish whether it contains any infectivity? Is there a test to do that?
  (Professor Sir John Krebs) There are two stages. Can you test the pâté or whether it has specified risk material in it, neural tissue or tissue from beef. There are tests for whether it contains beef and people are developing tests for the presence of neural tissue, specific markers for neural tissue. The second kind of question is can you test whether the infective prion is in a particular batch of meat products. The answer is yes, you could because you could take the pâté and inject it into animals. Usually they use the mice that I keep on referring to as the test animals. You could in principle and indeed in practice test whether a particular meat product contained infectivity, but I suspect the more important thing for health protection is to check that the meat product does not contain specified risk material because that would show that enforcement was being carried out properly.


 
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