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More on uncertainty and food safety investigations

Our summary last month of the largest foodborne illness outbreak of the last decade in the U.S. (salmonella in green peppers) and in Europe (E. coli in organic sprouts) demonstrated the diabolical complexity faced by food safety regulators when they carry out investigations characterized by deep factual and scientific uncertainty.

In both cases, investigators were dealing with rare strains of pathogens, and traceability was complicated by the fact that the source was unpackaged vegetables — without bar codes or lot numbers — that were quickly consumed, often with other produce. Microbiological testing proved quite unhelpful so investigators had to rely primarily on epidemiology. Pressed for “results,” both cases had regulators initially jumping to the wrong conclusions, destroying in their wake the livelihood of many innocent people and seriously undermining the credibility of government food safety regulators.

Both cases prove the “Iron Law of Food Safety Outbreak Investigations” — that after the fact, academics and the media will criticize government regulators either for overreacting or underreacting.

Perhaps government regulators have themselves to blame for the Iron Law because they continue to buy into the academic theory and language that they are engaged in risk management. They should be so lucky.

The classical model of risk analysis falls far short in describing what regulators actually do and in providing much useful guidance on how they should do it. In both cases, regulators were not dealing with risk — a concept that surely involves at least some aspect of measuring probabilities. Rather, they were dealing with uncertainty and crisis management.

Weighing benefits

The language of risk disguises the degree of ambiguity inherent in large-scale food safety investigations. “Risk” creates the illusion of precision, of assessing hazards in quantitative terms, or measuring the probability of harm. Science-based quantitative expert risk assessments often disguise the underlying subjective framework of assumptions and understate the high degree of uncertainty.

Food safety risk assessors do not do double-blind laboratory studies over a long period; they generally just review the conclusions of other scientists. In fact, in spite of their name, they typically do not even assess cases of risk, as calculations of probability are usually impossible to determine especially in the context of an urgent food safety crisis.

The most that “risk assessors” can do is assess situations of uncertainty and then engage in a complex iterative process with decision makers to try to find ways to manage an immediate issue fraught with multiple perspectives where the science, however uncertain, is important but rarely determinative. Understanding what is going on is complicated, too, by everyone pretending the decision is mostly science based, unadulterated by policy considerations, and that they are managing the actual science health risk, not the perception of risk.

We need to abandon the language of risk and recognize that most food safety investigations are about issue management. We need to develop a new theoretical model and language that would borrow heavily from the emerging literature on adaptive management: in the face of such uncertainty, making policy choices and implementing regulatory decisions should be recognized as necessarily experimental; decisions are made that expect the unexpected; policies and regulatory responses are adapted as lessons are learned.

The new model would also have to more fully recognize that while food safety must be paramount, trade-offs and weighing benefits are always a necessary part of the process. And this model would have to grapple with communicating this uncertainty to a generally scientifically illiterate consumer who simply expects retailers to only sell safe food and expects the regulatory system to guarantee it.

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