Perception of Risks

 

Relative risk and our Perception of Risks

 

Life is full of risks; so many that we will all eventually die.  Watching Fox news, it seems new ones are being created daily.  We like to think we look at the risks around us and then logically decide what we will do, how much risk we are willing to take.  Psychologists and sociologists have shown the process is not so logical, and actually quite emotional.  We don’t compare risks evenly, and there are certain factors which push our internal buttons, causing this imperfect comparison.  In their excellent book, Risk!  , David Ropeik and George Gray summarize these “risk perception factors” excellently.  These factors apply to all risks, including radiation.  The decisions we make as individuals, and as a nation, are heavily influenced by our perception of risks, and for me this is particularly obvious with radiation.

Let’s examine how some of these factors (quoted from Risk!) apply directly to radiation in our lives.

“Most people are less afraid of risks that are natural than risks that are manmade.”

 In 25 years of practice I have never had a discussion with a patient about radiation risks in which the patient had knowledge and concern about natural sources of radiation.  Most don’t realize it exists, and no one worries about it.  But, a mammogram with an equally harmless dose is cause for extreme anxiety in many women.  Thousands of families were uprooted from their homes in a large area of the Ukraine after the Chernobyl disaster led to low levels of radioactive “contamination” in their regions.  They had to get away from this man-made radiation.  Many of them were relocated to areas of Russia with higher natural background radiation levels than the contamination they were fleeing.

Roger Bate, in his book Life’s Adventure, makes this point well.  “Dangers have become more apparent to modern society.  As analysis becomes more sophisticated we discover new things, some of which are disturbing.  Science has provided the ability to detect, isolate and test the effects of myriad chemicals (and radiation), whether man-made or naturally occurring, on laboratory animals.  The problem comes when a culprit is sought for unknown events, the fashion being to focus on man’s activity.  There is money, power and kudos in altering public policy.  Man’s power over nature is small, but his power over other men is significant.  Anthropogenic change can be halted, unlike most of nature’s.  Mans activities are therefore more stringently analyzed than nature’s.”

“Most people are less afraid of risks if the risk also confers some benefits they want.”

It is rare in my practice for a patient in extreme pain to question the safety of an X-ray test.  They want to know what hurts, and what can be done to stop it.  The risk of the radiation seems trivial in comparison, and I obviously agree with them.  In the United States we are nearing a crisis point in the question of what we are going to do with low level radioactive waste.  The benefits to society from the energy production and medical care that yielded the waste seem so distant and diffused, and the miniscule risk of the waste gets so inflated, that no locality wants to host a disposal site.  In the 80s, the nuclear power industry fell victim to a change in the public’s perception of the risks and benefits of nuclear generators.  The risks and benefits didn’t actually change, just the perception of them.  The return of the oil crisis has a lot of people reconsidering those benefits.

“Most people are more afraid of risk that can kill them in particularly awful ways, like being eaten by a shark, than they are of the risk of dying in less awful ways, like heart disease—the leading killer in America.”

Having read the preceding chapter, you have some concept of what radiation actually does and does not do to you.  Most people have little or no real information.  They do have lots of ideas and mental images of radiation induced mutations and monsters, primarily gruesome ones from TV and movies.  There also many anti-nuclear activists who love to propagate inflated and exaggrated risks of radiation.  I will cover bot the misleading sources in more detail later.  This false information amplifies the perception of risks from radiation.  Most people have a morbid fear of cancer, and their misperceptions of the association between cancer and radiation only amplify their feelings about radiation.

“Most people are less afraid of a risk they choose to take than of a risk imposed on them.”

Getting in a car is a voluntary risk, having a doctor tell you to have an X-ray exam seems involuntary.  You are put between the proverbial rock and hard spot.  You don’t want to be sick, but you’re afraid of the radiation.  Not really a free choice and this makes it seem all the more dangerous.

“Most people are less afraid of risks that come from places, people, corporations, or governments they trust, and more afraid if the risk comes from a source they don’t trust.”

The association of trust with perception of risk is a major factor when dealing with radiation.  Prior to the 1940s, the growth of science was seen as beneficial.  Science made life better, and there were very few negative outcomes.  Following Hiroshima, the American public began to see new discoveries in a different light.  Scientific innovations, such as genetic modification of foods, are now initially viewed with skepticism, especially if the motive for the change appears to be profit rather than a contribution to society.  Later, the public may come to trust both the science and the proponents, but only with time.  Following the Nixon era, distrust of the government increased dramatically.  I believe this lack of trust in science and the government contributed greatly to the public outcry over Three Mile Island.  Authorities repeatedly said,  ” There is no harm and no risk.”  No one believed  them, but time has shown they were being completely truthful.

“We are more afraid of risks that we are more aware of and less afraid of risks that we are less aware of.”

Our level of awareness certainly influences our decisions about radiation.  I do a lot of mammography.  Breast cancer is a very real problem for women, and although it is far from perfect, mammography is the best weapon we have to fight it.  Mammograms have improved dramatically in the last twenty years, both in their sensitivity for detecting small cancers, and in the decreasing dose required to make them.  Twenty years ago the risk of the radiation exposure from mammography was very small.  Now, it is virtually non-existent.  A day at the beach is more dangerous.  Still, every time a TV or magazine publicizes some theoretical risk of X-rays and mammograms, we have a surge of “aware” women who want to cancel their mammo appointment.  Mammography didn’t change overnight, just their awareness.

“We are more afraid of risks when uncertainty is high, and less afraid when we know more.”

This is perhaps the dominant factor I see in the public’s perception of low dose radiation risks (and why I am writing this blog).  There is  very good information showing a low dose of radiation is of no harm, but there will never be a controlled research study in humans that proves it.  The same thing could be said for diet sodas, computers and corn flakes, but very few people are phobic about these things.  Without this proof, many radiation experts and safety experts will never accept there is a threshold for radiation exposure—a level below which it is harmless, below which there is no risk of inducing cancer or genetic problems, a level at which it is actually beneficial.  When experts don’t agree, and they probably never will in this case, uncertainty exist.  The best agreement you will ever get is, "the risk is very low relative to many other things in your life."

“Adults are much more afraid of risks to their children than risks to themselves.”

Like most parents, I worry far more about my children than myself.  They must always buckle their seatbelt, while I might forget mine.  As I said in chapter 2, children are more susceptible to radiation effects, so this is not an unreasonable outlook.  However, those opposed to radiation, such as various environmental and health activists, frequently exaggerate the risks to our children, intentionally pushing this button they know every parent has, as they attempt to sway public opinion.

“You will generally be more afraid of a risk that could directly affect you than a risk that threatens others.”

Nuclear power and radioactive waste disposal are pretty clear examples of this risk perception factor.  Many people are philosophically neutral or positive on these radiation issues, until someone wants to put such a facility near their home.  The risk didn’t change, just the perception of who might be affected.

“Most people are more afraid of risks that are new than those they’ve lived with for a while.”

In my radiology practice I have seen this work both ways.  Most people are a little anxious the first time they have a new radiology procedure, such as a CT scan.  Patients with chronic illnesses return for regular CT scans with very little anxiety.  When we introduced Magnetic Resonance Imaging (MRI), which uses magnetic fields and radio waves, but no ionizing radiation, these CT experienced patients were very anxious prior to their first MRI scan. 

 

In analyzing our perception of the risks of radiation, it is useful to look at how Americans deal with other risks, both on an individual and national level.  We’ll start with fire, and then look at guns and cars.

Fire has been with man a long time, not as long as radiation, but we have been aware of fire for a much longer time.  We feel like we can control fire and choose when and how we use.  It is a familiar tool, a useful tool.  We worry more about fire around our children than ourselves, and we teach them to respect it at an early age.  “Don’t touch that, it’s hot.” 

Fire is dangerous.  Each year over 3,500 Americans die from fires.  Every community has a fire department because losing control of fire is such a common occurrence.  There are very few restrictions on our use of fire considering how dangerous it is, probably because it has so many benefits, we have lived with it so long and we usually make a choice to use it.  One has to wonder, if fire was invented this week, how many people, organizations and regulators would try and prevent us from using it?

 

Everyone, even the most avid gun user would agree, guns are dangerous.  In the hands of a criminal, a distraught teenager, an untrained user or an inquisitive child they are frequently lethal.  In 2005, 30,694  Americans died from firearms.  Apparently, in 1791, when the Bill of Rights was ratified, the benefits outweighed the risks.  Many Americans still adamantly agree with this, and they choose to own guns.  Those who choose not to own guns are still at risk from those who do, and this lack of control increases their  fear.  Most gun owners perceive their risks in modern America are lowered by having a gun in their home.  While this was probably true in 1791, it may not be now.   Surprisingly, there are usually more gun suicides and accidental deaths than murders each year.   At the state and national level there is an ongoing debate about the control of guns.  The risks are pretty obvious, but there is a lot of uncertainty, disagreement and lack of trust in the discussions about their benefits.

 

I like cars, I always have.  Cars are fun.  They are often a way of expressing our personalities.  I used to drive a Honda S2000, now I drive a little Scion.  It isn’t sexy, but far more practical.  (Sometimes it is sad how age changes us.)   With a car you can go from point A to points B,C,D,E,F,G,H,I and J very quickly and comfortably.  If you like, you can take the whole family. 

We all know Americans love cars.  We tend to ignore the fact that cars are dangerous.  In 2005 there were 43,667 motor vehicle traffic deaths in the US.  We don’t say, “He took the risk, and now he paid for it.  Should I keep driving?”  We say, “It was an accident, bad luck.  It won’t happen to us.”  Technically speaking, the risk of dying from a car accident in the US is one bezillion times higher than dying from low level radiation.  In reality, such a comparison is impossible to make except in jest, because we can’t name even one person who ever died from low level radiation. 

I have long been fascinated by the way we rationalize away and gloss over the risks of automobiles.  A typical holiday weekend fatality toll is much higher than the toll at Chernobyl, but we love our cars.  We all know someone who died in a car wreck, but we love our cars.  They are a leading contributor to air pollution, the green house effect and global warming, but we love our cars.  Our nation has built a huge infra-structure primarily to support and encourage the use of cars over safer, less polluting mass transit, because we love our cars.  The only time I remember being  afraid of cars was teaching my teenagers to drive.  

The risks of cars, guns and fire are huge compared to radiation, but our perception of those risks is tinted by rose colored glasses, and our decisions are guided by our perceptions of risk.