Risk In Perspective: Zero Risk Is an Impossible Dream

This series is a collaboration between neuroscientist Alison Bernstein and biologist Iida Ruishalme. Errors in risk perception are at the core of so many issues in science communication that we think this is a critical topic to explore in detail. This series is cross-posted on SciMoms and Thoughtscapism.

Alison and Iida would like to thank Anne Martin for her graphic design work in translating our abstract ideas into graphics. Anne is a designer, illustrator, and researcher currently finishing her PhD in Neurobiology and Anatomy at the University of Utah. You can see her work through her website at hungrybraindesign.com and follow her on Twitter @thehungrybrain. She also runs a blog teaching researchers how to visually communicate their science at vizsi.com.

Zero risk and zero exposure are impossible expectations

We often strive for choices with zero risk. However, zero risk is an impossible goal. Certain activists and consumers seem to want an even more conservative goal of zero exposure, whether there is risk or not. Zero risk and zero exposure are impossible goals. Nearly everything we do has both risks and benefits. Everything, even inaction, carries risk. Thus, decisions, both personal and regulatory, are a matter of balancing the relative risks and benefits of your choices and choosing the level of risk you find acceptable, rather than of trying (and inevitably failing) to avoid all risk and all exposure to hazards.

Removing risks and exposures does not always reduce total risk

This phenomenon is readily apparent in our widespread outrage over trace amounts of chemicals. We tend to assume that the mere presence of tiny amounts of a substance are as risky as any other hazard, even without evidence (or even a plausible mechanism) for harm. Some activists and consumers demand the removal of these trace amounts without consideration of the risk of removal or the replacements. There are real world consequences to this misguided activism.

Sometimes tangible comparisons to familiar everyday risks helps to put in context what scientists mean when they talk about ‘very low risk’. In a recent article, Danish researchers looked at the cumulative risk of all dietary pesticide residues and compared them to the larger risks of mycotoxins in food, as well as consumption of coffee and alcohol. The contribution of glyphosate residues to this risk, specifically, were so low as to correspond to about half a tablespoon of wine per year.

Exaggerating the risk of the unfamiliar

One of our fundamental cognitive biases is that we have an outsized focus on novel and unfamiliar risks. Novel risks are inflated in our thoughts, not due to their impact, but merely because of their newness or our lack of personal control over them. Contrast this with well-known, big-impact risk factors, such as a sedentary lifestyle, eating too few fruits and vegetables, smoking or drinking alcohol, and excessive sun exposure. Despite the large influence of these factors on many aspects of health, we don’t feel the same sense of alarm and urgency about these high-risk, yet familiar risks.

Stress about risks poses a health risk

We have a tendency to underestimate the effect of chronic stress on our health. While dangerous exposures overall have greatly diminished in the developed world, the knowledge of these hazards has become a source of anxiety, partly due to a broader scientific understanding of risks and exposures. In many cases, this chronic stress is a larger risk factor for disease than the exposures we are worried about. According the American Psychological Association, who conducts an annual “Stress in America” Survey:

While people can overcome minor episodes of stress by tapping into their body’s natural defenses to adapt to changing situations, excessive chronic stress, which is constant and persists over an extended period of time, can be psychologically and physically debilitating.

Unlike everyday stressors, which can be managed with healthy stress management behaviors, untreated chronic stress can result in serious health conditions including anxiety, insomnia, muscle pain, high blood pressure and a weakened immune system. Research shows that stress can contribute to the development of major illnesses, such as heart disease, depression and obesity. Some studies have even suggested that unhealthy chronic stress management, such as overeating “comfort” foods, has contributed to the growing obesity epidemic.

While some may dismiss worry about exposures as a cause of chronic stress, a few minutes in almost any parenting forum online will show that many consumers feel that they are living in a constant state of danger from the world around them. (Note: this is not to say that there are no real risks and dangers in modern, developed communities. However, the degree of fear about many hazards and risks is highly exaggerated.)

The risk landscape

It is important to remember that in many areas of human health, we have already identified the big risk factors. These large risk factors are the old and familiar ones, like excessive smoking and drinking, or skipping daily fruits and vegetables. In addition to the big factors, research is now able to identify smaller and smaller risk. We are down in the weeds teasing apart the things that contribute to the background levels of risk in the total population, or that pose risks to specific vulnerable populations.

A look at the overall landscape of a selection of modifiable risk factors common in the developed world.

Medicine and public health measures, based on these large risk factors, have enabled people in developed countries to attain a generally high level of welfare. Thus, we have become increasingly aware of smaller and smaller risks. This is not necessarily a bad thing as health and safety are more important to us than ever before — as long as we take an evidence-based approach to risk and managing risk.

If you would like to read more about different aspects of risk perception, please see the other parts of the series, which this article belongs to:

Risk In Perspective: Introduction

1) The difference between hazard and risk is a critical distinction.

2) All hazards are not equal.

3) Zero risk and zero exposure are impossible expectations.

4) Population risk is not the same as individual risk.

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For more perspectives to specific risks, such as those associated with food, medicine, radiation, and energy, you can read more under Farming and GMOsVaccines and Health and Climate and Energy.

If you would like to have a discussion in the comments below, please take note of my Commenting policy. In a nutshell:

  1. Be respectful.
  2. Back up your claims with evidence.

About Thoughtscapism

Cell Biologist, volunteer science communicator, and fiction writer.
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10 Responses to Risk In Perspective: Zero Risk Is an Impossible Dream

  1. angelahorn8 says:

    I’m currently studying epidemiology of non-communicable diseases. Amen to all that! A well-explained article and a really nice infographic. Thank you!

    Liked by 1 person

  2. Pingback: Risk In Perspective: Hazards Are Not All Created Equal | Thoughtscapism

  3. Pingback: Risk In Perspective: Hazard and Risk Are Critically Different Things | Thoughtscapism

  4. Pingback: Risk In Perspective | Thoughtscapism

  5. Randy Way says:

    I’ve assigned this blog series as required reading for all of my firefighters. The writing does an exceedingly good job of clarification without simplification of the abstract topic of risk. Good show!

    Liked by 1 person

  6. Sorry, but with low dose radiation the risk can actually be NEGATIVE.


  7. Robert Earl says:

    Helping the public understand hazards and risks in perspective is a critical for communication and education, and agree on the challenge to do so effectively. Largely applaud your friendly infographic and including the important dimensions of “Zero risk and zero exposure are impossible expectations” and “Stress about risk also poses a risk” to help put risk in perspective. A few questions arise on close examination of the graphic. Do the authors have a complete narrative to share, along with the data, scientific evidence analysis, and assumptions about how the position and proportion of each risk presented in the infographic was determined? You note some narrative about BPA, pesticide residues, radiation, etc., above, but little or no detail on some puzzling risks in the graphic, and what is not included. Why is “coffee” included at all? What places “beauty products” as far to the right? Why is “not wearing a seat belt” excluded? Food insecurity and potable drinking water, which are major risks in numerous developing countries, are absent. From biographic information accessible, note that Iida is from Northern Europe, now living in Switzerland; and Allison and Anne reside in Michigan and Utah, respectively, in the USA. Finally, it would be helpful to understand if the risks presented are for a European, US, or global audience.


    • Hello Robert,

      Thanks for your friendly comment and feedback. As you noted, we are based in Europe and US, and as we specify in the figure text, our examples apply most directly to the developed world. We describe the infographic as “a selection of modifiable risk factors common in the developed world.”

      It is not an attempt at exclusively including all risk factors, but simply putting some common ones in perspective. Things like car accidents, stress, and infectious disease (latter at least in the developing world), for instance are also rather large risk factors. We could compare their contribution to burden of disease or estimated shortening effect on life expectancy to make an educated approximation of the scale of the risk, and probably depict them as trees or shrubs as well. See for instance WHO top ten causes of deaths, with various breakdowns, also to clarify the differences in risks in higher and lower income countries here: http://www.who.int/mediacentre/factsheets/fs310/en/index1.html

      You wonder about coffee and beauty products, particularly. If you look at the paper we referred to regarding the risk of alcohol use vs pesticide residues, in Figure 5, you can find an estimate of the hazard quotient for coffee drinking, which is in line, though a slightly larger hazard than pesticides or mycotoxins. It’s simply another example of a very small risk factor, like the many other factors down in the weeds. https://www.sciencedirect.com/science/article/pii/S0278691517306877?via%3Dihub#fig5

      Beauty products are another small hazard, most often mild skin/lung irritation, but in some cases even potential carcinogenicity hazard like with hair dyes. This is not a large concern for normal consumers, again, so the risk factor is ‘down in the weeds’. https://www.cancer.org/cancer/cancer-causes/hair-dyes.html

      Hope my answers were helpful to you. Please don’t hesitate to ask if there are further questions on your mind.

      Have a great Sunday!


  8. Pingback: Risk In Perspective: Population Risk Does Not Equal Individual Risk | Thoughtscapism

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