Estimating risk: Concrete thinking vs. abstract thinking

Recent findings on construal level theory (CLT) suggest that abstract thinking leads to a lower estimated probability of an event occurring compared to concrete thinking.

concrete.thinkingWe applied this idea to the risk context and explored the influence of construal level (CL) on the overestimation of small and underestimation of large probabilities for risk estimates concerning a vague target person (Study 1 and Study 3) and personal risk estimates (Study 2).

We were specifically interested in whether the often-found overestimation of small probabilities could be reduced with abstract thinking, and the often-found underestimation of large probabilities was reduced with concrete thinking.

The results showed that CL influenced risk estimates. In particular, a concrete mindset led to higher risk estimates compared to an abstract mindset for several adverse events, including events with small and large probabilities.

This suggests that CL manipulation can indeed be used for improving the accuracy of lay people’s estimates of small and large probabilities. Moreover, the results suggest that professional risk managers’ risk estimates of common events (thus with a relatively high probability) could be improved by adopting a concrete mindset.

However, the abstract manipulation did not lead managers to estimate extremely unlikely events more accurately. Potential reasons for different CL manipulation effects on risk estimates’ accuracy between lay people and risk managers are discussed.

Thinking concrete increases the perceived likelihood of risks: The effect of construal level on risk estimation

Wiley Online Library, Risk Analysis, 26 June 2015, DOI: 10.1111/risa.12445

Eva Lermer, Bernhard Streicher, Rainer Sachs, Martina Raue, and Dieter Frey

Regulatory myths

Ronald L. Doering, the first president of the Canadian Food Inspection Agency and currently counsel in the Ottawa offices of Gowlings, writes:

ron.doeringOne of the most persistent regulatory myths is the notion that politics can and should be kept out of science-based regulatory decision making. But as Covello and Merkhofer have clearly shown: “In practice, assumptions that have policy implications enter into risk assessment at virtually every stage of the process. The idea of a risk assessment that is free, or nearly free, of policy considerations is beyond the realm of possibility.” It is surprising how much our public discourse is still dominated by the quaint utopian view that science and policy can be strictly separated.

This enduring myth is the basis of the current kerfuffle regarding the government’s “war on science,” the allegation that decisions are based on ideology, not science, that politicizing science is a very bad thing and that all decisions must be “evidence-based.” Ironically, these same critics make a virtue out of being skeptical of mainstream science by opposing, for example, fluoridation, GM food, irradiation and vaccinations. But their basic misunderstanding is that they believe or pretend to believe that science and policy can be separated. Their whole concept of “evidence-based” is flawed. It is the legitimate and necessary role of politicians to take the science-based risk assessment and then carry out the policy based risk management function by weighing the social, political, economic, ethical and environmental factors in order to arrive at the appropriate regulatory decision. In our democratic system scientists cannot, should not, carry out what is the legitimate role of elected politicians and their senior advisers.

What should be the acceptable level of PCBs in farmed salmon? What should be the appropriate mix of rules to prevent the importation of BSE into Canada? What is the acceptable level of phthalates in plastic toys? What are the best regulations to prevent the importation of FMD into Canada? What is the right regulatory regime for the approval of genetically modified traits in seeds? What is the acceptable level of GM corn in wheat products? What should be the necessary rules for the storage of high level nuclear waste? What is the safe level of BPA in water bottles? How should the level of salt in processed food products be regulated? Should it continue to be illegal to sell raw milk? What should be the rules for raw milk cheese? This is just a small sample of the science-based public policy issues with which I was directly involved in recent years.

riskIn all of these cases it was the regulator’s task to protect the public health and safety of Canadians through a complex process of weighing the many factors involved without, may I say again, the aid of some quantitative cost benefit analysis; the factors were too complex to be monetized in a way that would be useful for decision making. In all these cases the science was relevant by not determinative. And yet in all these cases the parties argued that the basic question was one of science: if only we could get the science right, the public policy answer would follow. If only the world were that simple.

When I was president of Canada’s largest science-based regulator, I dealt regularly with scientists who were seemingly unaware how much their science advice was imbued with unstated policy considerations, and how much the uncertainty of their science required the consideration of other factors. Many academic and government scientists and their public sector unions still shamelessly march in the streets arguing that decisions must only be “evidence-based.” My nutrition and food science students seem genuinely unaware, uncomfortable even, with the idea that science-based health risk assessments are replete with policy considerations.

We need to engender a broad public debate about the role of science and scientists in policy making. For starters we need to debunk the myth that politics can and should be taken out of science-based regulation making.

Food safety nerds: 2 methods for risk-based microbiological criteria for Campylobacter in broiler meat

Risk-based microbiological criteria can offer a tool to control Campylobacter in the broiler meat production chain.

HBO's "True Detective" Season 1 / Director: Cary FukunagaRecently two approaches have been applied to derive such criteria and to analyse their potential impact in terms of human health risk reduction: the risk-based version of the established microbiological criteria approach, that applies a microbiological limit (ML) for sample data, and the Danish “case-by- case” risk assessment approach, that applies a limit for the relative risk estimate (relative risk limit, RRL) based on sample data.

In this study, data sets from Sweden and Denmark are used to compare the performance of the two approaches in terms of efficiency, i.e. the balance between the residual risk after implementation of the criterion and the percentage of non-complying batches, and the attending uncertainty.

The analysis shows that the two approaches are equally efficient, and suggests that the RRL criterion is attended with less uncertainty. The two approaches are compared and their advantages and disadvantages are discussed. Given the uncertainties attending the results of the analysis, more research in terms of data collection, risk assessment and uncertainty analysis would be needed to develop these risk-based criteria further.

Food Control, Volume 53, Pages 177-184

Maarten Nauta, Jens Kirk Andersen, Pirkko Tuominen, Jukka Ranta, Roland Lindqvist

EU vs. North America uses of risk analysis

Maybe this is why Europe is somewhat messed up over food.

The European Food Safety Authority says “the decision to separate the tasks of risk assessment and risk management just over a decade ago has transformed the safety of Europe’s food. And while there is wide recognition that this change has strengthened the safety of the food chain, riskman-cycleuncertainty can still exist over the difference in roles and responsibilities of risk assessors and risk managers. … Risk assessors provide independent scientific advice on potential threats in the food chain. Risk managers use this advice as a basis for making decisions to address these issues. At a European level, this separation of roles is fundamental and enshrined in law. It was introduced to make clear the distinction between science and politics; to place independent science-based assessment at the heart of policy making.”

Maybe there’s “wide recognition” in Europe, but in the U.S. and Canada risk assessment, management and communication are recognized as interdependent roles, forming the overall risk analysis approach.

Because value judgements are an inherent part of human activity, the U.S. National Academy of Sciences recommended in 1997 that risk assessors expand risk characterization beyond the current practice of merely
translating the results of a risk analysis into non-technical terms. This
limited approach is “seriously deficient” and should be replaced with an
analytical-deliberative approach that involves stakeholders from the very
inception of a risk assessment.

The report can be found at the RiskWorld web site at:

It has pretty circles.


Punk rock and journal articles: leave them wanting more

Michael Batz (right, pretty much as shown) writes:

A friend of mine who played guitar in a punk band once told me to “always leave them wanting more.” He was talking about how some bands played for too long, leaving the Michael Batz RZ ED PART 2audience bored by the end. Their approach, by contrast, was to play about 15 songs in 12 minutes.

Sometimes it made people a little angry.

I guess I learned a lesson from him, since it took my colleagues and I 10 years to publish the results of our foodborne illness risk ranking work in a pair of journal articles in 2012. Or maybe I’m just lazy. In any case, as much as we tried to get it all in there, we definitely left folks wanting more. Which is to say, we got a lot of questions about the details. And I guess that’s half the point of these things, right? So we decided to go further into the weeds.Three papers in 12 years? Pretty punk rock. Or lazy. Whatever.

US: Disease-outcome trees, EQ-5d scores, and estimated annual losses of quality-adjusted life years (QALYs) for 14 foodborne pathogens in the United States


Foodborne Pathogens and Disease doi:10.1089/fpd.2013.1658

Michael Batz, Sandra Hoffmann, and J. Glenn Morris Jr

Measures of disease burden such as quality-adjusted life years (QALYs) are increasingly important to risk-based food safety policy. They provide a means of comparing relative risk from diverse health outcomes. We present detailed disease-outcome trees and EQ-5D scoring for 14 major foodborne pathogens representing over 95% of foodborne illnesses, hospitalizations, and deaths due to specified agents in the United States (Campylobacter spp., Clostridium perfringens, Cryptosporidium parvum, Cyclospora cayetanensis, tumblr_lqhmvwbjca1qe1tt5o1_500Escherichia coli O157:H7, Shiga toxin–producing E. coli non-O157, Listeria monocytogenes, nontyphoidal Salmonella enterica, Shigella, Toxoplasma gondii, Vibrio vulnificus, Vibrio parahaemolyticus and other noncholera Vibrio, and Yersinia enterocolitica). We estimate over 5800 QALYs lost per 1000 cases of L. monocytogenes and V. vulnificus, compared to 125 QALYs lost per 1000 cases of T. gondii, 26 for E. coli O157:H7, 16 for Salmonella and Campylobacter, and 14 for Y. enterocolitica. The remaining 7 pathogens are estimated to cause less than 5 QALYs lost per 1000 cases. In total, these 14 pathogens cause over 61,000 in QALY loss annually, with more than 90% due solely to acute infection being responsible for 65% of total QALY loss, with premature mortality and morbidity due to chronic and congenital illness responsible for another 28%. These estimates of the burden of chronic sequelae are likely conservative; additional epidemiological research is needed to support more accurate burden estimates. This study shows the value of using integrated metrics for comparing disease burden, and the need to consider chronic and congenital illness when prioritizing foodborne pathogens.

Piping hot is not sound science

Dr Andrew Wadge, chief scientist at the UK Food Standards Agency (FSA), told a webinar that food policies and advice based on the best available science are needed to protect consumers from 1M cases of UK foodborne illness every year.

Telling consumers to cook their turkey until it is piping hot is not sound science.

Stick it in.

Food Safety Risk Analysis graduate course available by distance, Jan. 2011

I went to graduate school because the girl I was living with was a veterinary student who had another three years of schooling ahead, so I thought I needed a reason to hang around.

That’s not a good reason to go to graduate school.

I married the girl and had kids but dropped out of grad school.

Distance education may have helped.

The World Health Organization estimates that up to 30 per cent of people in developed countries get sick from the food and water they consume each year and has identified five factors of food handling that contribute to these illnesses: improper cooking procedures; temperature abuse during storage; lack of hygiene and sanitation by food handlers; cross-contamination between raw and fresh ready to eat foods; and acquiring food from unsafe sources.

Food Safety Risk Analysis examines the interwoven roles of risk assessment, management and communication – defined as risk analysis – and applies these concepts to problems and policy development in food safety. This course will aid students in developing the ability to critically examine food safety risk issues from various stakeholder perspectives, leading to risk management and communication activities to reduce the impact of foodborne disease.

A significant portion of the course will focus on the importance of thorough research and good communication skills, as well as the suitability of communication efforts. The emphasis on acquiring and critically evaluating electronic information will assist students in further developing lifelong learning skills. The course will be presented through lectures, case study presentations, and Internet-based support material including text, audio and video through the extensive database maintained by Dr. Douglas Powell of Kansas State University and colleagues in food safety. This course will be of interest to anyone in the food industry, food safety regulators, public health inspectors, food service managers and others.

A complete course syllabus is available here. Or e-mail me,

For enrolment information, visit the Kansas State Division of Continuing Education website at and click on Courses at the top of the page to search for it. Interested individuals can click the Add Class to Interest List button. This will prompt the student to either log into iSIS if they are currently a student and enroll, or provide information about applying to the university if they are not a student.

I have nothing to do with the prices. But at least it’s not a humanities degree (that’s a joke; see video below).

Great communications, lousy management: Is Maple Leaf the new Odwalla?

Last week I dusted off some old slides to talk with an industry group about best practices in food safety. I got bored of hearing myself say the same thing about 10 years ago, but sometimes, it’s best to stick to basics.

Risk analysis is composed of risk assessment, management and communication. Over the years I’ve studied dozens of outbreaks of foodborne illness and concluded that a producer, or processor, or retailer needs to be excellent at all three—assessment, management and communication – and if they fail at just one, they will suffer the economic and associated hardships.

There is no doubt that Michael McCain and Maple Leaf Foods has practiced excellent risk communication since being fingered as the source of a listeria outbreak in Canada that killed at least 20 and sickened 60. I’ve said so from the beginning. I’ve also said that

it is impossible to judge whether Maple Leaf was practicing good risk management and assessment because no one will come clean on who knew what when as the outbreak was developing.

But that hasn’t stopped Canadians from gushing in a blindly patriotic way about how McCain set the ‘gold standard’ for reputational and financial management.

Maybe, but communications alone is never enough, just like science alone is never enough. And precisely because no one – government or industry – has come clean on who knew what when, it’s not surprising to hear

the Canadian federal government has delayed for months the release of notes on conference calls

held at the height of last summer’s deadly listeriosis outbreak — a lag some experts say breaks Ottawa’s own information laws.

At issue is an Access to Information request by The Canadian Press to the Privy Council Office for “all transcripts and minutes” of the crucial exchanges last August and September.

The Odwalla 1996 outbreak of E. coli O157:H7 in unpasteurized juice was also textbook risk communication, but the company was eventually revealed to have cut corners and ignored warning signs. Will Maple Leaf undergo similar scrutiny?

Below is an except from my 1997 book, Mad Cows and Mother’s Milk, about the Odwalla outbreak.

Sometime in late September 1996, 16-month-old Anna Gimmestad of Denver has a glass of Smoothie juice manufactured by  Odwalla Inc. After her parents noticed bloody diarrhea, Anna was admitted to Children’s Hospital on Oct. 16.  On 8 November 1996 she died after going into cardiac and respiratory arrest.  Anna had severe kidney problems, related to hemolytic uremic syndrome and her heart had stopped several times in previous days.

The juice Anna — and 65 others who got sick — drank was contaminated with E. coli O157:H7, linked to fresh, unpasteurized apple cider used as a base in the juices manufactured by Odwalla.  Because they are unpasteurized, Odwalla’s drinks are shipped in cold storage and have only a two-week shelf life.  Odwalla was founded 16 years ago on the premise that fresh, natural fruit juices nourish the spirit.  And the bank balance: in fiscal 1996, Odwalla sales jumped 65 per cent to $60 million (U.S.).  Company chairman Greg Steltenpohl has told reporters that the company did not routinely test for E. coli because it was advised by industry experts that the acid level in the apple juice was sufficient to kill the bug.

Who these industry experts are remains a mystery.  Odwalla insists the experts were the U.S. Food and Drug Administration.  The FDA isn’t sure who was warned and when.   In addition to all the academic research and media coverage concerning VTEC cited above — even all of the stories involving VTEC surviving in acidic environments — Odwalla claims ignorance.

In terms of crisis management — and outbreaks of foodborne illness are increasingly contributing to the case study literature on crisis management — Odwalla responded appropriately.  Company officials responded in a timely and compassionate fashion, initiating a complete recall and co-operating with authorities after a link was first made on Oct. 30 between their juice and illness.  They issued timely and comprehensive press statements, and even opened a web site containing background information on both the company and E. coli O157:H7.  Upon learning of Anna’s death, Steltenpohl issued a statement which said, “On behalf of myself and the people at Odwalla, I want to say how deeply saddened and sorry we are to learn of the loss of this child.  Our hearts go out to the family and our primary concern at this moment is to see that we are doing everything we can to help them.”

For Odwalla, or any food firm to say it had no knowledge that E. coli O157 could survive in an acid environment is unacceptable.  When one of us called this $60-million-a-year-company with the great public relations, to ask why they didn’t know that E. coli O157 was a risk in cider, it took over a day to return the call.   That’s a long time in crisis-management time.  More galling was that the company spokeswoman said she had received my message, but that her phone mysteriously couldn’t call Canada that day.

Great public relations; lousy management.  What this outbreak, along with cyclospora in fresh fruit in the spring of 1996 and dozens of others, demonstrates is that, vigilance, from farm to fork, is a mandatory requirement in a global food system.  Risk assessment, management and communication must be interlinked to accommodate new scientific and public information.  And that includes those funky and natural fruit juices.

If I was a tomato grower, this is what I would say — but only if it were true

I started worked with Ontario Greenhouse Vegetable Growers in 1998. The general manager at the time, Denton Hoffman, saw the U.S. export market growing rapidly, and told me of his recurring nightmare … one he wanted to prevent.

"The phone rings and it’s a retailer on the U.S. east coast. He says he’s got a customer who says she got sick from eating my Ontario greenhouse tomatoes. What do I say?"

That was the challenge Denton laid out for my group in 1998. Using a risk analysis approach, we assessed the risks for all 220 or so Ontario greenhouse producers, developed management schemes, and communicated what we were doing to buyers, consumers, whoever.

We learned lots of things about building trust with individual growers (which means visiting their farms, not plopping them in a classroom and trying to make them HACCP experts), coming up with practical, farm-based solutions, and being on call 24/7 for when those phone calls come in (that’s me and Amber Leudtke, back in about 2001, in a greenhouse, above right).

But I could never get the group to take the final step and really promote their food safety program. I suggested putting a url on the stickers at retail that would link to a series of videos showing whoever wanted to see them the food safety practices undertaken by the growers.

During the latest Salmonella-in-tomatoes outbreak, a rep for Nature Sweet, a grower in San Antonio e-mailed me and said, what should we do? This grower does great things for food safety. So I told her.

The rep wrote me back last week and said,

"I spoke with you last week briefly about the tomato outbreak.  You made the suggestion about putting our company’s safety practices on blogs, YouTube, etc.  Well, we took your advice and have created a video that is up on YouTube.  Here is the link to the video if you’re interested to view it,"

The video is also below. Sure, I’d rather see a farmer than the marketing dude, and the intro will have to be redone for future use, but the rest is great.

And they spelled it out in a press release:

Our greenhouse growing practices are the foundation of our food safety program:

• The water supply used in our greenhouses is self-contained, filtered, and secure. Water from each well and each greenhouse farm is continuously monitored and tested for purity by our staff and by third party experts.
• We use only natural fertilizers.

• Our tomatoes are picked under sanitary conditions.

• Food safety begins with the seed. Our tomato seeds are always naturally selected, disinfected and germinated under sanitary conditions.

• Within each greenhouse, we control and monitor all intakes – water, nutrients, and pest control.

In addition to our greenhouse practices, we also employ the following food safety initiatives:

• Regulate all aspects of tomato production and processing, as well as employ the best agricultural practices.

• Monitor all of our systems continuously to ensure that our produce exceeds the highest food safety standards and FDA guidelines. In addition to our adherence to HACCP-based safety practices, we follow rigorous training, growing, packing, and shipping standards.

• Use a food safety coding system that provides us with traceability of every case and pallet of tomatoes to the greenhouse in which they are grown. In addition, each individual selling unit has a comprehensive food safety tracking code.

• Test, monitor, and audit our products, our water, our processes, and our procedures regularly with staff and third-party experts.

I can quibble about details. But it’s a great start, and, like transparency in risk assessments, now that it’s out there, it can be improved. It’s a lot better than just telling consumers to wash their tomatoes or it’s local so it’s safe.