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Humans are bad at quantitative risk assessment [ClearOnMoney]
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Commentary

Humans are bad at quantitative risk assessment

20 Mar 2011 by Jim Fickett.

The danger from building at low elevations in range of tsunamis has, so far, been much greater than risks from reactors, though the former gets little current discussion. Risks to workers and risks from contaminated food in Japan are real but very small. The peak in fear has probably passed, and it is possible that the financial risks in uranium-related investments have also been overblown.

I suppose genomes that encode panic upon rumor of danger have usually had the evolutionary advantage over those that encode rational planning for the 100-year flood. So I should not be surprised, even if I am frustrated, that Homo so-called-sapiens is so remarkably bad at reasoning quantitatively about risk.

And – full disclosure – I am still invested in uranium, which I believe is an important part of the long-term global energy picture.

All that said, let's set the record straight.

Danger from reactors, danger from tsunamis

If radiation damage so far, which is probably limited to (1) some health effects for Tokyo Electric workers and (2) a major, long-term clean-up in the neighborhood of the power plant, ends up being the worst of it, everyone should really be extremely pleased. Compared to the immediate death and destruction from the tsunami, this is a very, very small impact.

There has been much hand-wringing and criticism that Tokyo Electric failed to plan adequately for the tsunami. And it is probably true that they underestimated the danger. But what about all the houses that were built a few feet above sea level, in locations that were surely known to be in danger of flooding? Thousands of people died because those towns were in locations that were clearly vulnerable. Why not a word about requiring all new building to be at higher elevations?

Senator Boxer, from California, who may have been exposed to the concept of “numbers” at some time in her distant past, wants reactors to be “one thousand percent safe”, and spent a good deal of time in a recent hearing trying to bludgeon the Nuclear Regulatory Commission into closing reactors in California, but said not a word about the dangers of drowning. But this evacutation planning map suggests there is a significant risk of large regions around San Francisco Bay being damaged by a tsunami in the case of a California earthquake.

Radiation risks come in many gradations

People seem to be able to understand that low doses of radiation, for example from a chest x-ray, may constitute an acceptable risk. But apparently that is a black-and-white distinction, with most people unable to understand that radiation limits are essentially arbitrary, and some exposure over the limit can, while increasing health risks, actually present relatively little danger.

Bloomberg, under the sensational headline Japan Churns Through ‘Heroic’ Workers Hitting Radiation Limits for Humans, admits halfway through the article that the incremental health risk is relatively small:

“A worker receiving a dose of 100 millisieverts from these emergency operations will have a future risk of a serious cancer from this dose of less than 1 percent,” said Richard Wakeford, a professor of epidemiology at the University of Manchester’s Dalton Nuclear Institute in the U.K. That compares with a risk of dying from cancer in the absence of this radiation exposure of about 20 to 25 percent, Wakeford said in an e-mail today.

I'm not saying the limit is unreasonable, or that a 1% additional risk of cancer is negligible. But when thousands are dead or missing, and many lack clean water or hospital care, is a 1% additional lifetime risk of cancer really the biggest news?

Similarly, the Financial Times, usually rather restrained, proclaims that Japan faces food safety crisis. So how bad is the risk, really?

Tests found levels of radioactive iodine up to seven times the legal limit in samples of raw milk …

An average consumer would have to drink such milk for a year to get the equivalent radioactive dose to a single CT scan.

That is a “safety crisis”? Come now.

At least in the above cases there is some real danger, even if relatively small. But Americans have been panicking about a danger so small it cannot be measured at all. As far away as Illinois there has been a run on potassium iodide tables, so that the Illinois department of public health needed to put out a notice that

“Residents who take potassium iodide out of concern of possible radiation exposure from the events in Japan could be putting their health at risk due to side effects,” said Illinois Department of Public Health Director Dr. Damon T. Arnold. “The state health department does not recommend taking potassium iodide at this time and strongly encourages residents to learn about the drug, when to take it and its impact. The department has posted materials on our Web site.”

No quantitative data on the side effects was given. But I am quite sure that the risk, for Americans, of an automobile accident while driving to the drug store to get your potassium iodide is significantly greater than any risk of radiation poisoning from Japan.

Risk and opportunity

The irrationality of humans does annoy me, but it also presents opportunities. Markets almost always overreact. The peak in fear is likely past and, although I already have a significant position in uranium, I might decide to raise it on Monday. If so, I will not be counting on any gain in the short- to medium-term, when the backlash could be real enough.