TSE in Animal Populations - Fact and Fiction September 10 11, 2003 Fort Collins, Colorado Conrad G. Brunk, PhD University of Victoria, Canada

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1 Understanding the Perception of TSE Risks TSE in Animal Populations - Fact and Fiction September 10 11, 2003 Fort Collins, Colorado Conrad G. Brunk, PhD University of Victoria, Canada

2 Summary What is the Debate Over Safety All About? Public Risk Perception and Acceptable Risk The Profile of BSE (What you see is what you would predict) What Can We Can Learn From BSE in the Case of Other TSE s (Especially CWD)

3 What is the Debate Over Safety All About?

4 What Tasks are Involved in Managing Risks Like TSE s? Assessing the Risks What is the nature of the hazard? How much harm is it likely to cause? Primarily a Scientific Enterprise Limiting the Risks Determining what level of the risk is acceptable Adopting measures to maintain the risk within safe limits Primarily a Political/Managerial Enterprise Managing Public Concerns re. the Risks Maintaining Public Confidence in the first two tasks Primarily a Political/Managerial Enterprise

5 The Science Short-Cut to Safety The temptation of science based risk management is to find a quasi-scientific solution to the issue of acceptable risk. Scientific Temptations If the risk assessment is low enough, we can count it as effectively zero. Find a quantitative algorithm for establishing acceptable risk, e.g. Risk Benefit Analysis Objective Threshold (NOAEL)

6 The Risk of Science-Based Safety Analysis When the magnitude of the risk is scientifically assessed as extremely low, the acceptability of the risk will be seen to be high. Or, if the risk is assessed scientifically to be lower than the expected benefits, it will appear, objectively, to be an acceptable risk If the public still fears the risk, or finds it unacceptable, they appear to the scientist as Not appreciating or understanding the science, or Having irrational attitudes towards the risks.

7 Expert Solution for Public Risk Debates Improve science education in the schools and in the media Assumption: the more people understand science, the more rational their attitudes towards risk will be. Engage in strategic communication Formulate messages about risk and safety in ways that produce the desired response (risk acceptance or aversion) Assumption: attitudes and preferences re. Risks can be manipulated like all consumer preferences.

8 What Is Wrong With This Solution? It fails to recognize that risk acceptability involves far more than simply the scientific assessment of the magnitude of risk (or benefit). Risk acceptability involves a complex set of underlying value judgments about the nature of particular risks and their management. These value judgments are often deeply rooted in the social, religious, and political culture. Thus they are resistant to strategic communication

9 Unpacking The Concept of Safety The question of safety is fundamentally a question of the acceptability of risks. Acceptability of risk is not an objective feature of the world. It is not determinable by the empirical or analytical methods of science. Acceptability of risk is nothing more nor less than its acceptance (by some group)

10 To Whom is the Risk Acceptable? Options: To those who benefit from the risk ( Risk-Beneficiaries )? To those who bear the risk ( Risk- Bearers )? To the experts who assess and manage the risk ( Risk Managers )? Correct Answer?

11 By What Standard is Risk Acceptable? Zero-risk (or de minimus)? Actual Acceptance? (e.g. label it and let the market decide) Presumed or Implied Acceptance? Substantial Equivalence, GRAS ) Expert Standards Threshold standards (ADI, Natural Background) ALARA (cost effectiveness) Risk-Benefit standards

12 How Risk Experts Tend to View Safety Prefer quantitative algorithms for risk acceptability. Risk-cost-benefit calculations ( If this risk produces a greater benefit, shouldn t we take the risk? ) Risk comparisons ( You already take risk A, why are you afraid of the lower risk B? ) Risk probability is more important than risk magnitude ( The probability of X is so low, it is insignificant. It doesn t matter what its magnitude might be, it won t materialize anyway )

13 Expert Perceptions of Safety Experts prefer to withhold judgment on risks for which there is not highly reliable scientific evidence ( high confidence levels ). This often gets expressed as no significant risk 13 Non-experts are more likely to assume the possibility of risk in the absence of reliable scientific evidence.

14 Experts Typically View Non- Experts As : 14 overestimating low-probability high consequence risks underestimating high probability, low consequence risks (e.g., non-lethal, nondebilitating illness) having contradictory and illogical attitudes towards risks (e.g., they smoke cigarettes while demanding organic foods) Demanding zero-risk when it is rarely possible

15 Non-Expert Perceptions of Safety 15 Greater attention given to the magnitude of the potential harm than to its probability Greater attention to the acceptability of risk than to its magnitude Greater attention given to the qualitative than to the quantitative aspects of risk.

16 Qualitative Aspects of Non- Expert Perceptions of Safety Unfamiliarity of Risk (incl. Uncertainty in the Science) Distribution of Risks and Benefits Dread Factor in the Risk Catastrophic Potential of Risk (loss of control and remediation)

17 Qualitative Aspects of Non- Expert Perceptions of Safety Non-quantifiable Probabilities (E.G.. Human Error, Novel Occurrences, Etc.) The Risk Is Associated with an (Un)Ethical Activity (e.g., BSE, Cloning) Voluntariness of the Risk-taking Trust in the Risk Assessors & Managers

18 The Profile of BSE/vCJD What You See Is What You Would Predict

19 BSE/vCJD Profile:The Trust Factor The U.K. M.A.F.F. experience The early denial of any human health risk zero-risk messages The perceived failure to take adequate food safety precautions The Canadian BSE Case Focus of media attention on what the CFIA had failed to do in detecting the case and testing for other BSE cases CFIA seems to have won public trust on its handling of the issue significant rise in domestic beef consumption

20 BSE/vCJD : The Dread Factors High unfamiliarity factor: Prion diseases little understood Invisibility ( Is it in my food or isn t it? What part of the cow is infected, and how is infectivity transferred) Dreadful disease symptoms

21 BSE/vCJD: Scientific Uncertainties What really causes the diseases? How/when do TSE s cross species barriers? What parts of the animal contain infectivity? What slaughtering techniques isolate infectivity? How reliable are the tests for BSE? How many animals need to be tested? What is the incubation period for BSE/vCJD What will be long-term incidence of vcjd? Etc., etc.

22 BSE/vCJD: Controllability & Voluntariness Perceived low Controllability of the risk Consumer has no way of determining if beef contains BSE prions due to the uncertainties noted earlier Only protection strategy is radical change in dietary habits (which most people resist) Perceived low Voluntariness of the risk It is imposed by industry practices, regulators, etc. Consumer has no way to choose exposure Public self-perception switches from Risk- Taker to Risk-Victim

23 BSE/vCJD: Distribution of Risks and Benefits The benefits of the feeding practices (animal protein supplements) are perceived to accrue to the risk producers (agricultural industry) The risks, however, are borne by consumers (as well as by the industry)

24 BSE/vCJD: Unethical Practices Produce the Risk BSE/vCJD risk perceived as resulting from an unethical farming practice (feeding cows to cows, meat to herbivores) Not an Act of God (People are generally more tolerant of divinely imposed risks)

25 Summary of BSE/vCJD Risk Perception Because BSE/vCJD risk rates high on the qualitative factors, the public tolerance of the risk is, predictably, very low. This low level of risk acceptability is behind the demand (especially in Europe) for drastic risk reduction measures. Elsewhere in the low BSE risk world these perceptions support highly restrictive trade barriers until a country gets its own case!

26 The Profile of CWD Risk: What Can We Can Learn From BSE in the Case of Other TSE s (Especially CWD)

27 CWD: It s Mad Cow in Deer and Elk: The Association Factor CWD has characteristics that associate the risk closely with BSE: It is a prion disease, like BSE It s origin and routes of infection are uncertain, what is its relation to BSE? The initial scientific claim about BSE was that it was not transmissible to humans. This is also the initial scientific claim about CWD is it reliable? The farm practice factor. Is game farming practice the source of the disease?

28 CWD: The Uncertainty Factor CWD is a prion disease Prion diseases are still largely unfamiliar (even to the scientific community) Does CWD pose a threat to human health? No Scientific Evidence of Human Health Risk Sound familiar? Public perception of no evidence when uncertainty.

29 CWD: Distribution of Risk/Benefit Currently this factor shapes up differently from BSE/vCJD There is no established human health risk There is no established risk of CWD crossing into cattle, sheep, or other ruminants (no threat to BSE- Free status of cattle) So, the primary risk is to game farmers (the risk beneficiaries as well). Currently it may be the wild game hunters who feel the most at risk with no off-setting benefits.

30 CWD: The Trust Factor As in BSE/vCJD, this could turn out to be crucial in the perception of the CWD risk If government regulators are perceived to have mismanaged the risk it will become a serious issue. This could be triggered by a significant discovery of an unpredicted new risk (or allegation by credible sources) a major accident or outbreak of disease associated with a farming or game management practice.

31 Key Issues in the Future of the CWD Issue in North America How Trustworthy is the Science? How confident is the conclusion that CWD does not pose a human health risk? How confident is the conclusion that CWD does not pose a risk of cross species transfer? How Trustworthy are the Risk Managers? The Game Farming Factor. The Can we trust the government factor.