The Competitiveness of Nations

in a Global Knowledge-Based Economy

May 2005

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George G. Khachatourians

How Well Understood is the “Science” of Food Safety?

Chapter 2.  In: Governing Food: Science, Safety and Trade,

 P. W. B. Phillips and R. Wolfe (eds.), 2002.

Queen-McGill University Publishing, 13-23.

 

Index

Introduction

Scientific Frameworks

Applying the Kuhn Model to Safety Issues in Cattle Production

Biotechnology and Food

Lessons for governing food

References

Introduction

How do scientific controversies affect national and global governance? What are the implications of changing scientific understanding for risk assessment? This book as a whole is premised on a triangular tension between science, safety and trade, but we can see similar tensions within the domain of science itself. Without understanding these tensions, we cannot hope to understand the problems new science creates for risk assessment, management and communications.

In this paper I discuss the policy issues posed by scientific change through the two topics that have generated the greatest public reaction: the use of antibiotics, hormones and waste products in meat production from animals, and the introduction of genetically modified organisms in food production from plants. Both forms of technology are aimed at increasing farm productivity. The use of antibiotics and hormones in meat-producing animals is intended first to enhance the animal's ability either to gain weight or to produce milk, and second as prophylaxis against infectious disease, while the use of waste products was an attempt to improve the profitability of the sector.  Plant biotechnology, an umbrella term for a number of interconnected disciplines, offers the promise of generating new products and processes that will make more efficient use of resources of land, water, and nutrients. The Governments of both Canada and the United Kingdom embraced biotechnology as part of their national strategy in the late 1970s (Joint Working Party, 1980; The Federal Task Force on Biotechnology, 1981).

The challenge facing scientists, regulators, industry and citizens is that scientific understanding is continually evolving.  This chapter uses Thomas Kuhn’s approach to scientific development to illustrate how the science of food is changing, and how those changes have stressed the food safety system.

 Index

scientific frameworks

Risk assessment is defined as “a scientifically based process,” [1] but what might that mean? The risk assessment process engages academic and government experts who collaborate in the generation of a consensual understanding of the issues with testing organizations, national expert panels, FAO/WHO Expert Committees, international scientific bodies such as the International Plant Protection Convention and international organizations like the Organization for Economic Cooperation and Development (OECD). While this process depends on open dissemination of scientific information, it becomes more complex as disciplinary expertise fragments and specializes, interdisciplinary contributions to food issues increase, and as new products create new hazards and differing levels of exposure. Consumers and citizens respond to this fragmentation of information with growing distrust of experts and regulators.  Scientists respond through a process of public debate, which can at times clarify and comfort or at times confuse and heighten concerns.

Kuhn (1970), in “The Structure of Scientific Revolutions,” attempts to construct a generalized picture of the process by which a science is born and undergoes change and development.  Kuhn used the term “paradigm” to denote the body of knowledge that was part of "normal science".  Scientific development, according to Kuhn, begins with the study of natural phenomena, which leads to a set of theories that explain differing viewpoints. This in turn results in the development of a pre-paradigm (or accepted body of knowledge), which after much empirical testing, evolves into a paradigm.  A paradigm thus has a number of questions and answers that are accepted as ‘knowns’. They are related to each other through the concepts and methods employed in research and are disseminated through publication in scientific journals.  The evolutionary process of getting to "normal science" involves a series of research efforts and discoveries within the existing paradigm that lead to the further articulation of the paradigm, the exploration of other possibilities within the paradigm, the use of existing theory to predict new facts, the solving of scientific puzzles, and the development of new applications of theory.  During the course of scientific inquiry, new phenomena are discovered and new or revised explanations are developed for these phenomena. In other words, new questions emerge when we discover something unexpected and new answers are found through further research. In both cases things that were “unknown” drive the search for answers, or new “knowns.” As research progresses, there may be further discoveries of natural phenomena that violate the paradigm-induced expectations that govern "normal science".  Researchers discover problems not previously known, and existing theory sometimes proves unable to account for the anomalous facts.  Sometimes in such circumstances a researcher is able to define and exemplify a new conceptual and methodological framework incommensurate with the old that leads to a new solution, thereby allowing the continuation of "normal science" within a new paradigm (Green, 1971).

   While Kuhn's examples of the formation and transformation of paradigms were drawn entirely from the history of the physical sciences, this analytical framework can be applied to food science. The challenge for risk management is distinguishing between situations of normal science, where a “science-based approach” to risk assessment can and should be left to experts, and the more ambiguous situation where unknowns make a “precautionary approach” the prudent course of action. The classic quadrant box can be used to describe the relationships between knowns (Ks) and unknowns (UKs).  As detailed in Figure 1, within the frame of understanding the relationship between the known (K) and unknown (UK) questions and answers of "normal science", four situations can arise.  We can divide the frame into four combinations or boxes, where both the question and answer are known, (K-K), where one is known but the other is not, (K-UK, UK-K) and finally where neither the question nor answer is known (UK-UK).

 

Figure 1.  Kuhnian paradigms of known and unknown.

 

 

The top left box provides few difficulties for scientists, regulators and citizens as they consider food safety—problems for governance usually do not arise when the science is clear, information is readily available, and the community of science agrees that both questions and answers are “known”. But scientists usually do not agree on what is known, so the boxes at lower left and upper right represent the common challenge for risk analysis, one that increasingly worries citizens who do not know which scientist, regulator or activist to believe. The most dangerous situation is when both question and answer are not known, for then we are unaware of the risks we are running.

[1] See the Codex Alimentarius Commission "Definitions of Risk Analysis Terms Related to Food Safety". Risk analysis itself was defined as: "A process consisting of three components: risk assessment, risk management and risk communication.”

 Index

Applying the Kuhn Model to safety issues in Cattle production

Numerous food safety examples could fit this framework, but for this chapter I use 4 examples from the cattle industry (Figure 2) the cases of antibiotic resistant bacteria (ABRB), the use of hormones in milk cattle (rBST), the presence of bovine spongiform encephalopathy (BSE) in cows and the occurrence of variant Crutzefield-Jacob Disease (vCJD) in humans.  The first two cases rest on the foundations of microbiology and food science developed over the past fifty years. In the second two cases, however, normal science did not expect the emergence of prion diseases like BSE, which are still poorly understood, nor did it then expect that such diseases could move from one species to another, as is thought to be the case with vCJD. 

 

Figure 2.  Kuhnian paradigms of known and unknown related to cattle production

 

    In the first case, after thirty years of animal husbandry experience in the United Kingdom and Canada, we understand the questions about whether or not to augment animal feed with antibiotics and hormones for weight gain and meat quality.  Today, most animal producers, and all intensified livestock operations (ILOs), use feed additives. From the standpoint of food production, both the problem (how to satisfy market demand while achieving profitability) and the solution (large scale animal production) are known.  ILOs utilizing hormone and antibiotic feeds experience a 5-14% improvement in weight gain.  Over the past thirty years, the experience of using antibiotics has produced a number of new questions and answers from the standpoint of human and animal health, including the recent emergence of antibiotic resistant bacteria and their transmission throughout rural and urban environments. Vancomycin, an important antibiotic that has been used since the 1950s for humans and for farm animals since the 1980s, is similar to the antibiotic avoparcin, which is used solely in veterinary practice and animal feeds in the European Union (avoparcin has not been licensed for use in Canada or the United States as a feed additive because of the determination it had carcinogenic potential). Normal science agrees that, over time, bacteria can develop resistance to antibiotics, which requires the continuous search for new drugs; what was not clear was that resistance could transfer between animals and humans. In Europe, vancomycin-resistant enterococci (VRE) have been isolated, first from sewage treatment plants in Britain and small towns in Germany, and later in manure samples from pig and poultry farms (Khachatourians, 1998). It is known that VRE isolates generally are cross-resistant to avoparcin (i.e. a bacteria that are resistant to avoparcin will also be resistant to vancomycin). A possible reason for the presence of VRE in humans is that VRE is associated with animals being fed avoparcin.  Accordingly the response of normal science to the emergence of the new known factor—antibiotic resistant bacteria—was a new known answer—a ban on avoparcin. Although the feed additive manufacturing industry in Europe initially protested the withdrawal of avoparcin from farm animal use, there are now restrictions on the use of avoparcin in Denmark and Britain (Khachatourians, 1998). While one might consider this a "known-unknown" situation, it is fairly clear that normal science anticipated this possibility thirty years earlier the Swann Committee (1969) in the UK, fearing that there were potential problems had recommended strict adherence to regulations governing the use of antibiotics in animal feed and none of the normal science needed to change to adopt to the new circumstances.  Scientists and regulators simply extended regulations to manage this new circumstance: the United States, Sweden and Denmark followed suit in 1997, the WHO in 1998, and several Canadian provinces more recently (Khachatourians, 1998). 

   The second case involves the use of recombinant bovine somatotropin (rBST), a non-therapeutic drug produced by genetic engineering, to increase milk production in dairy cattle. The question is known (i.e. how can milk production be increased safely), but the answer is not (i.e. scientists continue to debate about the long-term effects of rBST on animal and human health). In 1994, both the European Union and Canada imposed a moratorium on the use of rBST, although BST occurs naturally in cows.  From 1993 to 1995 inquiries were held to resolve the scientific and policy aspects of this issue. On 5 May 1998, the Senate of Canada unanimously passed a motion urging the government to defer licensing rBST for at least one year and thereafter until the long-term risks to public health were known (Standing Senate Committee on Agriculture and Forestry.  1999). On 14 January 1999, Health Canada announced that it would not approve rBST for sale in Canada. The disapproval was based on the findings of two expert advisory panels, both of which recommended that approval for rBST not be granted until long-term studies on human health were submitted and reviewed.

The third case concerns the emergence of BSE in the cattle population in the United Kingdom in the 1980s. In this case the question (what causes BSE) was known too late, but the preliminary answer was readily apparent (cattle became visibly affected in the mid 1980s). Normal science had part of the question—the presence of scrapie in sheep had been known for decades and there was scientific knowledge of kuru-kuru and anthropological records of neuro-degenerative disease due to certain tribal cannibalistic practices (Rhodes, 1997)—but the link to the problems facing the cattle industry in the 1980s was not clear. The outbreak of BSE did not on the face of it appear to be solely linked to the diet of animal proteins. English herds appeared to be especially at risk while Scottish cattle and North American cattle were not.  The question began to be formulated with the discovery of prion diseases and the correlation between infected animals and the eating of proteins by animals of the same or similar species.  The different incidence of the wasting disease in cattle between England and other areas that also allowed a diet of animal proteins led to a further discovery that prions could be reduced or eliminated if the materials were heated to a high temperature in preparing the meal.  The United Kingdom had lowered the required temperature years earlier while the other jurisdictions maintained a higher required temperature.  Even before the different bits of evidence and theory helped the scientists formulate a complete known question, governments in the United Kingdom and North America acted in a precautionary way and changed ruminant feeding regulations to ban animal proteins or require more stringent processing.  The United Kingdom, as early as 1988, tightened rules on feeding animal proteins.  Even so, in absence of a clear question, regulators in continental Europe continued to allow feeds with animal proteins while others allowed the import of potentially infected cattle from the United Kingdom.  As a result, BSE gained a foothold in cattle herds in France, Germany and the Low Countries in the late 1990s, causing a tightening of rules there as well.  As a result, no major cattle producers now allow industry to feed cows with protein materials derived from other ruminants. The initial incidence in the United Kingdom of BSE, its epidemiological rise in the cattle herds and the scientific cause-effect track were finally known in 1998, restoring the management of animal feeding to the known-known world, as fully fleshed out questions and answers are well on the way to becoming part of “normal science.”

In the fourth case, both the questions and answers were unknown, since nobody thought to ask if mad cow disease could spread to humans. This UK-UK situation initially created a false sense of security and, then, when evidence of some risk appeared, led to widespread concern in the United Kingdom.  At the same time as the cattle industry was sorting out what BSE was and how it was transmitted in the cattle industry, epidemiologists noted a troubling rise in the number of people affected with Creutzfeldt-Jakob disease (CJD), a rare and fatal neurodegenerative disease of unknown cause. This, therefore, represented a case of an unknown question (what is the link between BSE and CJD) and an unknown answer (is the incidence of CJD a problem related to BSE).  Because of the epidemic of BSE in cattle, in May 1990 the United Kingdom established a national surveillance program for CJD in the United Kingdom 1990. By 1996 the unit was able to report (Will et al., 1996) that some new cases of CJD had neuropathological changes which, to their knowledge, have not been previously reported and that those affected were relatively young people (the usual case of sporadic CJD in the United Kingdom affected individuals that were aged 50 to 70).  While the program determined that the average number of cases of sporadic CJD identified annually after 1990 was higher than in previous surveillance periods extending back to 1970, it was impossible to say with certainty to what extent these changes reflect an improvement in case ascertainment and to what extent, if any, they reflect changes in incidence.  Up until 31 December 2000, there were 84 deaths from definite or probable variant CJD (vCJD) in the United Kingdom  (in addition 2 probable cases died in January 2001 and a further 7 probable cases remained alive as at 31 January 2001). Of the 84 deaths to 31 December 2000, 75 were confirmed neuropathologically with a further two awaiting confirmation.  Over time this unknown-unknown situation has shifted slowly to a situation of closer to “normal science.” The surveillance program produced evidence that something unusual or unexpected was occurring, and spurred on scientists to seek out a better description of the problem (answer) and then to seek causes of the vCJD (the question). The difference in this case is that in the absence of at least one known, the government had no way to react.  Hence, although scientists had suspicions that vCJD might be linked to BSE, their inability to establish that link until 1996 forestalled any government response.  In 1996, an article in the Lancet (Will, et al., 1996) formally defined the answer (there was a new variant CJD) and pointed to a suspected causal link (with BSE and cattle fed with ruminant proteins), which provided some direction for government action.  While the government response was not exemplary (see chapter by Mann), it signaled the reorientation of this problem from being unknown to at least being partly known.

The four-quadrant model of knowns and unknowns applied against safety concerns related to animal rearing illustrates a number of points.  First, if cause and effect are known and part of ‘normal science,’ assessing, managing and communicating about risks is relatively straightforward.  Where one of either the cause or effect is unknown, governments are placed in a tricky position of trying to find the best response, but they are often forced to react in some precautionary way.  Where both cause and effect are unknown, blissful ignorance rules and governments are neither pressed to nor able to act.  Science needs to do its stuff to add some knowledge of either cause or effect for governments to be able to respond.

 Index

Biotechnology and Food

            A different but equally significant issue in science policy discourse is the use of biotechnology in foods. In terms of science, genetic engineering of plants is not synonymous with biotechnology, as some choose to view it, but one ingredient of biotechnology.  As a part of science, genetic engineering promises to make important contributions to food design and production, creating an agricultural framework that provides both environmental sustainability and food security (Khachatourians, 2001). But in getting there, there are a number of discordant science and policy elements that must be addressed: the development and application of biotechnology for foods has precipitated a major debate within and beyond the scientific community about what safety means and how it can be measured and secured.  As a new part of science, biotechnology is not part of “normal science”: scientists, regulators and citizens disagree on the questions and on whether science is approaching the answers. That is, few people think that we are in a K-K situation, and many worry that we are really in the UK-UK situation of not knowing what we do not know about the new science and its applications. The effort to define the unknowns and to search for new knowns has triggered a wide debate about how science can and should support governance systems.

Biotechnology definitely has ample “unknown" areas and the paradigms about how to gain insights are shifting rapidly and often inconsistently. In both the United Kingdom and Canada, for instance, the public has been highly selective in accepting commodities derived from engineered microorganisms—health care products derived from transgenic plants go uncontested while GM foods are often spurned.  As a result, the debate over GM foods has divided both the scientific and policy communities as much as the general public. Safety is no longer simply a scientific concept—it now has a major societal component.  Policy makers face an interpretative dilemma. Governments on both sides of the Atlantic, acting more from cultural and societal perspectives than from a scientific base, have used the break in "normal science" to adopt inconsistent and often conflicting precautionary positions related to the use of biotechnology and transgenic techniques.

There are many questions that science alone cannot adequately address.  Where do the biological facts meet social truths?  Are social responses to advances in food sciences influenced by "normal science", experimentation and observation or paradigm shifts?  As pointed out by Sackett and coworkers (1996), can and should compilations or critical reviews of the science literature provide authoritative summations? How does a scientist examine re-interpretation and conjectures?  These questions go well beyond the scope of ‘normal science” but are fundamental to the effective governance of food.

   Finally, while objectivity in performing scientific inquiry is a must, the biotechnology debate has starkly revealed that scientific experts do not transmit objective information to policy makers in a way that will have a positive influence on the formulation of policy.  Scientists by and large do not articulate scientific data in a manner that is comprehensible for politicians, leading to the inevitable absence of objective data in policy debate. As a result, emotion and rhetoric are often more influential than objective data. Furthermore, research programs that attempt to address public concerns often have the opposite effect to that promised.  During times of breaks in "normal science", politicians and scientists participate in consensual and mutually aggrandizing promises and predictions—often offering a cure for cancer here, and the elimination of environmental pollution there.  Calls for further research reflect a bias about the perceived role of science in policy making.   The prevailing view is that science is there to solve problems.  Instead, one could argue using Kuhn’s framework that science is perhaps more important in defining the ‘unknowns’ and seeking new ‘knowns’, thereby creating the foundation for sound governance.  Without knowledge about the problems and answers, risk assessment, management and communications will founder.

 

Lessons for governing food

Advances in food sciences including biotechnology and particularly the techniques of genetic engineering have generated new hopes and fears about food safety.  These interests have attracted some of the best and brightest scientists to these new sciences and their application towards producing safe foods.  The potential of new knowledge being applied to understand issues of food safety is enormous.  It is critical, however, for both scientists and the rest of society to understand how ‘normal science’ operates and how science can contribute to defining the knowns and unknowns that can influence effective governance of food safety.

Nevertheless, one must be realistic about what science can do.  The appeal to “science” will not necessarily resolve disputes. We might assume that science speaks a universal language of ‘truth,” but it does not. Scientific knowledge is especially contested in such complex domains as human health. Citizens often ask questions to which science can have no answers, which simply highlights that scientific risk assessments often are forced to make implicit value judgments to come to a conclusion. Even when regulators use formal cost-benefit analysis, which involves explicit valuation of social impacts, the results must necessarily depend on a subjective valuation of things like human life and the environment. Moreover, it is not clear that there is such a thing as ‘normal science’ in this world of rapidly advancing knowledge.  Even is there was a consensus about the science, views about what matters often differ between different societies and cultures, with the result that countries adopt divergent policies. As a result, the international science community is often unable to agree on acceptable tolerances, the tests to be done and how they should be interpreted. While the community of science may not respect national boundaries, it does respond to the questions that get asked, which leads to competing scientific views. Fundamentally, what differs between countries is how we weight the information provided and how we balance competing interests, as, for instance, between consumers and producers or between human health, the environment and the economy. Finally, even if policymakers and regulators do decide based on some internationally accepted scientific consensus, many consumers do not trust their own government’s, let alone a foreign government’s, scientific judgement to adequately protect the safety of their food supply.

 Index

References

Green, J. C . 1971. The Kuhnian Paradigm and the Darwinian revolution in natural history.  Pp.3-25. In: Perspectives in the History of Science and Technology (Ed.) D. H. D. Roller.  University of Oklahoma Press.  Norman, OH.

Joint Working Party.  1980.  Biotechnology.  The report of a Joint Working Party (Advisory Council for Applied Research and Development, Advisory Board for the Research Councils, and The Royal Society) of United Kingdom.  London. Her Majesty's Stationary Office.  Pp. 63.

Khachatourians, G. G. 1998.  Agricultural use of antibiotics, and the evolution and transfer of antibiotic resistant bacteria.  Canadian Medical Association Journal. 159:1129-1136.

Khachatourians, G.  G. 2002.  Agriculture and Food Crops: Development, science and society Pp. 1-27. In: Transgenic Plants and Crops (Eds.) G. G. Khachatourians, A. McHughen, W-K. Nip, R. Scorza, Y-H. Hui. Eds. New York: Marcel Dekker Inc. 876+xxii pages.

Kuhn, T. 1970. The Structure of Scientific Revolutions. 2nd Edition, Chicago: University of Chicago Press.

Rhodes, R. 1997.  Deadly feasts: tracking the secrets of a terrifying new plague.  New York: Simon & Schuster, Pp. 259.

Sackett, D. L, W.M. C. Rosenberg, J. A. Muir Gray, R.B. Haynes, and W S. Richardson.  1996.  Evidence based medicine:  What it is and what it isn't.  British Medical Journal.  312:71-72.

Swann Committee.  1969.  Report of the Joint Committee on the use of Antibiotics in Animal Husbandry and Veterinary Medicine.  Her Majesty’s Stationery Office.  London.

Standing Senate Committee on Agriculture and Forestry.  1999.  rBST and The Drug Approval Process.  Report of the Committee, March 1999. Pp. 34.

The Federal Task Force on Biotechnology.  1981.  Biotechnology: A Development Plan for Canada.  The report of the Task Force on Biotechnology to the Minister of State for Science and Technology.  Ottawa. Supply and Services Canada.  Pp. 51.

Will, R.G., J W Ironside, M Zeidler, S N Cousens, K Estibeiro, A Alperovitch, S Poser, M Pocchiari, A Hofman, P G Smith. 1996. “A new variant of Creutzfeldt-Jakob disease in the UK” Lancet 347: 921- 25.

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The Competitiveness of Nations

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May 2005

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